NEWS
author blanchet
Fri Apr 30 09:36:45 2010 +0200 (2010-04-30)
changeset 36569 3a29eb7606c3
parent 36461 e741ba542b61
child 36508 03d2a2d0ee4a
child 36530 01dd30889788
permissions -rw-r--r--
added "no_atp" for theorems that are automatically used or included by Sledgehammer when appropriate (about combinators and fequal)
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Schematic theorem statements need to be explicitly markup as such,
    10 via commands 'schematic_lemma', 'schematic_theorem',
    11 'schematic_corollary'.  Thus the relevance of the proof is made
    12 syntactically clear, which impacts performance in a parallel or
    13 asynchronous interactive environment.  Minor INCOMPATIBILITY.
    14 
    15 * Authentic syntax for *all* logical entities (type classes, type
    16 constructors, term constants): provides simple and robust
    17 correspondence between formal entities and concrete syntax.  Within
    18 the parse tree / AST representations, "constants" are decorated by
    19 their category (class, type, const) and spelled out explicitly with
    20 their full internal name.
    21 
    22 Substantial INCOMPATIBILITY concerning low-level syntax declarations
    23 and translations (translation rules and translation functions in ML).
    24 Some hints on upgrading:
    25 
    26   - Many existing uses of 'syntax' and 'translations' can be replaced
    27     by more modern 'type_notation', 'notation' and 'abbreviation',
    28     which are independent of this issue.
    29 
    30   - 'translations' require markup within the AST; the term syntax
    31     provides the following special forms:
    32 
    33       CONST c   -- produces syntax version of constant c from context
    34       XCONST c  -- literally c, checked as constant from context
    35       c         -- literally c, if declared by 'syntax'
    36 
    37     Plain identifiers are treated as AST variables -- occasionally the
    38     system indicates accidental variables via the error "rhs contains
    39     extra variables".
    40 
    41     Type classes and type constructors are marked according to their
    42     concrete syntax.  Some old translations rules need to be written
    43     for the "type" category, using type constructor application
    44     instead of pseudo-term application of the default category
    45     "logic".
    46 
    47   - 'parse_translation' etc. in ML may use the following
    48     antiquotations:
    49 
    50       @{class_syntax c}   -- type class c within parse tree / AST
    51       @{term_syntax c}    -- type constructor c within parse tree / AST
    52       @{const_syntax c}   -- ML version of "CONST c" above
    53       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
    54 
    55   - Literal types within 'typed_print_translations', i.e. those *not*
    56     represented as pseudo-terms are represented verbatim.  Use @{class
    57     c} or @{type_name c} here instead of the above syntax
    58     antiquotations.
    59 
    60 Note that old non-authentic syntax was based on unqualified base
    61 names, so all of the above "constant" names would coincide.  Recall
    62 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
    63 diagnose syntax problems.
    64 
    65 * Type constructors admit general mixfix syntax, not just infix.
    66 
    67 * Use of cumulative prems via "!" in some proof methods has been
    68 discontinued (legacy feature).
    69 
    70 * References 'trace_simp' and 'debug_simp' have been replaced by
    71 configuration options stored in the context. Enabling tracing
    72 (the case of debugging is similar) in proofs works via
    73 
    74   using [[trace_simp=true]]
    75 
    76 Tracing is then active for all invocations of the simplifier
    77 in subsequent goal refinement steps. Tracing may also still be
    78 enabled or disabled via the ProofGeneral settings menu.
    79 
    80 * Separate commands 'hide_class', 'hide_type', 'hide_const',
    81 'hide_fact' replace the former 'hide' KIND command.  Minor
    82 INCOMPATIBILITY.
    83 
    84 
    85 *** Pure ***
    86 
    87 * Empty class specifications observe default sort.  INCOMPATIBILITY.
    88 
    89 * Old 'axclass' has been discontinued.  Use 'class' instead.  INCOMPATIBILITY.
    90 
    91 * Code generator: simple concept for abstract datatypes obeying invariants.
    92 
    93 * Local theory specifications may depend on extra type variables that
    94 are not present in the result type -- arguments TYPE('a) :: 'a itself
    95 are added internally.  For example:
    96 
    97   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
    98 
    99 * Code generator: details of internal data cache have no impact on
   100 the user space functionality any longer.
   101 
   102 * Methods unfold_locales and intro_locales ignore non-locale subgoals.  This
   103 is more appropriate for interpretations with 'where'.  INCOMPATIBILITY.
   104 
   105 * Discontinued unnamed infix syntax (legacy feature for many years) --
   106 need to specify constant name and syntax separately.  Internal ML
   107 datatype constructors have been renamed from InfixName to Infix etc.
   108 Minor INCOMPATIBILITY.
   109 
   110 * Command 'example_proof' opens an empty proof body.  This allows to
   111 experiment with Isar, without producing any persistent result.
   112 
   113 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   114 within a local theory context, with explicit checking of the
   115 constructors involved (in contrast to the raw 'syntax' versions).
   116 
   117 * Commands 'types' and 'typedecl' now work within a local theory
   118 context -- without introducing dependencies on parameters or
   119 assumptions, which is not possible in Isabelle/Pure.
   120 
   121 * Command 'defaultsort' is renamed to 'default_sort', it works within
   122 a local theory context.  Minor INCOMPATIBILITY.
   123 
   124 * Proof terms: Type substitutions on proof constants now use canonical
   125 order of type variables. INCOMPATIBILITY: Tools working with proof
   126 terms may need to be adapted.
   127 
   128 
   129 *** HOL ***
   130 
   131 * Library theory 'RBT' renamed to 'RBT_Impl'; new library theory 'RBT'
   132 provides abstract red-black tree type which is backed by RBT_Impl
   133 as implementation.  INCOMPATIBILTY.
   134 
   135 * Command 'typedef' now works within a local theory context -- without
   136 introducing dependencies on parameters or assumptions, which is not
   137 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   138 contain multiple interpretations of local typedefs (with different
   139 non-emptiness proofs), even in a global theory context.
   140 
   141 * Theory Library/Coinductive_List has been removed -- superceded by
   142 AFP/thys/Coinductive.
   143 
   144 * Split off theory Big_Operators containing setsum, setprod, Inf_fin, Sup_fin,
   145 Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   146 
   147 * Theory "Rational" renamed to "Rat", for consistency with "Nat", "Int" etc.
   148 INCOMPATIBILITY.
   149 
   150 * New set of rules "ac_simps" provides combined assoc / commute rewrites
   151 for all interpretations of the appropriate generic locales.
   152 
   153 * Renamed theory "OrderedGroup" to "Groups" and split theory "Ring_and_Field"
   154 into theories "Rings" and "Fields";  for more appropriate and more
   155 consistent names suitable for name prefixes within the HOL theories.
   156 INCOMPATIBILITY.
   157 
   158 * Some generic constants have been put to appropriate theories:
   159   * less_eq, less: Orderings
   160   * zero, one, plus, minus, uminus, times, abs, sgn: Groups
   161   * inverse, divide: Rings
   162 INCOMPATIBILITY.
   163 
   164 * More consistent naming of type classes involving orderings (and lattices):
   165 
   166     lower_semilattice                   ~> semilattice_inf
   167     upper_semilattice                   ~> semilattice_sup
   168 
   169     dense_linear_order                  ~> dense_linorder
   170 
   171     pordered_ab_group_add               ~> ordered_ab_group_add
   172     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   173     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   174     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   175     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   176     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   177     pordered_cancel_semiring            ~> ordered_cancel_semiring
   178     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   179     pordered_comm_ring                  ~> ordered_comm_ring
   180     pordered_comm_semiring              ~> ordered_comm_semiring
   181     pordered_ring                       ~> ordered_ring
   182     pordered_ring_abs                   ~> ordered_ring_abs
   183     pordered_semiring                   ~> ordered_semiring
   184 
   185     ordered_ab_group_add                ~> linordered_ab_group_add
   186     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   187     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   188     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   189     ordered_field                       ~> linordered_field
   190     ordered_field_no_lb                 ~> linordered_field_no_lb
   191     ordered_field_no_ub                 ~> linordered_field_no_ub
   192     ordered_field_dense_linear_order    ~> dense_linordered_field
   193     ordered_idom                        ~> linordered_idom
   194     ordered_ring                        ~> linordered_ring
   195     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   196     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   197     ordered_ring_strict                 ~> linordered_ring_strict
   198     ordered_semidom                     ~> linordered_semidom
   199     ordered_semiring                    ~> linordered_semiring
   200     ordered_semiring_1                  ~> linordered_semiring_1
   201     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   202     ordered_semiring_strict             ~> linordered_semiring_strict
   203 
   204   The following slightly odd type classes have been moved to
   205   a separate theory Library/Lattice_Algebras.thy:
   206 
   207     lordered_ab_group_add               ~> lattice_ab_group_add
   208     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   209     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   210     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   211     lordered_ring                       ~> lattice_ring
   212 
   213 INCOMPATIBILITY.
   214 
   215 * Refined field classes:
   216   * classes division_ring_inverse_zero, field_inverse_zero, linordered_field_inverse_zero
   217     include rule inverse 0 = 0 -- subsumes former division_by_zero class.
   218   * numerous lemmas have been ported from field to division_ring;
   219   INCOMPATIBILITY.
   220 
   221 * Refined algebra theorem collections:
   222   * dropped theorem group group_simps, use algebra_simps instead;
   223   * dropped theorem group ring_simps, use field_simps instead;
   224   * proper theorem collection field_simps subsumes former theorem groups field_eq_simps and field_simps;
   225   * dropped lemma eq_minus_self_iff which is a duplicate for equal_neg_zero.
   226   INCOMPATIBILITY.
   227 
   228 * Theory Finite_Set and List: some lemmas have been generalized from
   229 sets to lattices:
   230 
   231   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   232   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   233   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   234   union_Union_fold_union        ~> sup_Sup_fold_sup
   235   Inter_fold_inter              ~> Inf_fold_inf
   236   Union_fold_union              ~> Sup_fold_sup
   237   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   238   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   239   INTER_fold_inter              ~> INFI_fold_inf
   240   UNION_fold_union              ~> SUPR_fold_sup
   241 
   242 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   243 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   244 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   245 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   246 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   247 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   248 
   249 * HOLogic.strip_psplit: types are returned in syntactic order, similar
   250 to other strip and tuple operations.  INCOMPATIBILITY.
   251 
   252 * Reorganized theory Multiset: swapped notation of pointwise and multiset order:
   253   * pointwise ordering is instance of class order with standard syntax <= and <;
   254   * multiset ordering has syntax <=# and <#; partial order properties are provided
   255       by means of interpretation with prefix multiset_order;
   256   * less duplication, less historical organization of sections,
   257       conversion from associations lists to multisets, rudimentary code generation;
   258   * use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union, if needed.
   259   INCOMPATIBILITY.
   260 
   261 * Code generation: ML and OCaml code is decorated with signatures.
   262 
   263 * Theory List: added transpose.
   264 
   265 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   266 clash with new theory Quotient in Main HOL.
   267 
   268 * Library/Nat_Bijection.thy is a collection of bijective functions
   269 between nat and other types, which supersedes the older libraries
   270 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   271 
   272   Constants:
   273   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   274   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   275   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   276   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   277   Countable.pair_encode           ~> prod_encode
   278   NatIso.prod2nat                 ~> prod_encode
   279   NatIso.nat2prod                 ~> prod_decode
   280   NatIso.sum2nat                  ~> sum_encode
   281   NatIso.nat2sum                  ~> sum_decode
   282   NatIso.list2nat                 ~> list_encode
   283   NatIso.nat2list                 ~> list_decode
   284   NatIso.set2nat                  ~> set_encode
   285   NatIso.nat2set                  ~> set_decode
   286 
   287   Lemmas:
   288   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   289   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   290   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   291   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   292   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   293   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   294   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   295   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   296   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   297   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   298   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   299   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   300   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   301 
   302 
   303 *** ML ***
   304 
   305 * Sorts.certify_sort and derived "cert" operations for types and terms
   306 no longer minimize sorts.  Thus certification at the boundary of the
   307 inference kernel becomes invariant under addition of class relations,
   308 which is an important monotonicity principle.  Sorts are now minimized
   309 in the syntax layer only, at the boundary between the end-user and the
   310 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   311 explicitly in rare situations.
   312 
   313 * Antiquotations for basic formal entities:
   314 
   315     @{class NAME}         -- type class
   316     @{class_syntax NAME}  -- syntax representation of the above
   317 
   318     @{type_name NAME}     -- logical type
   319     @{type_abbrev NAME}   -- type abbreviation
   320     @{nonterminal NAME}   -- type of concrete syntactic category
   321     @{type_syntax NAME}   -- syntax representation of any of the above
   322 
   323     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   324     @{const_abbrev NAME}  -- abbreviated constant
   325     @{const_syntax NAME}  -- syntax representation of any of the above
   326 
   327 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   328 syntax constant (cf. 'syntax' command).
   329 
   330 * Antiquotation @{make_string} inlines a function to print arbitrary
   331 values similar to the ML toplevel.  The result is compiler dependent
   332 and may fall back on "?" in certain situations.
   333 
   334 * Renamed old-style Drule.standard to Drule.export_without_context, to
   335 emphasize that this is in no way a standard operation.
   336 INCOMPATIBILITY.
   337 
   338 * Curried take and drop in library.ML; negative length is interpreted
   339 as infinity (as in chop).  INCOMPATIBILITY.
   340 
   341 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   342 usual for resolution.  Rare INCOMPATIBILITY.
   343 
   344 * Discontinued old TheoryDataFun with its copy/init operation -- data
   345 needs to be pure.  Functor Theory_Data_PP retains the traditional
   346 Pretty.pp argument to merge, which is absent in the standard
   347 Theory_Data version.
   348 
   349 * Renamed varify/unvarify operations to varify_global/unvarify_global
   350 to emphasize that these only work in a global situation (which is
   351 quite rare).
   352 
   353 * Configuration options now admit dynamic default values, depending on
   354 the context or even global references.
   355 
   356 
   357 *** System ***
   358 
   359 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   360 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   361 proof terms are enabled unconditionally in the new HOL-Proofs image.
   362 
   363 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   364 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   365 respectively.
   366 
   367 * Old lib/scripts/polyml-platform is superseded by the
   368 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   369 variant, even on a 64 bit machine.  The following example setting
   370 prefers 64 bit if available:
   371 
   372   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   373 
   374 
   375 
   376 New in Isabelle2009-1 (December 2009)
   377 -------------------------------------
   378 
   379 *** General ***
   380 
   381 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   382 one backslash should be used, even in ML sources.
   383 
   384 
   385 *** Pure ***
   386 
   387 * Locale interpretation propagates mixins along the locale hierarchy.
   388 The currently only available mixins are the equations used to map
   389 local definitions to terms of the target domain of an interpretation.
   390 
   391 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   392 loc" to print all interpretations of locale "loc" in the theory.
   393 Interpretations in proofs are not shown.
   394 
   395 * Thoroughly revised locales tutorial.  New section on conditional
   396 interpretation.
   397 
   398 * On instantiation of classes, remaining undefined class parameters
   399 are formally declared.  INCOMPATIBILITY.
   400 
   401 
   402 *** Document preparation ***
   403 
   404 * New generalized style concept for printing terms: @{foo (style) ...}
   405 instead of @{foo_style style ...}  (old form is still retained for
   406 backward compatibility).  Styles can be also applied for
   407 antiquotations prop, term_type and typeof.
   408 
   409 
   410 *** HOL ***
   411 
   412 * New proof method "smt" for a combination of first-order logic with
   413 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   414 fixed-size bitvectors; there is also basic support for higher-order
   415 features (esp. lambda abstractions).  It is an incomplete decision
   416 procedure based on external SMT solvers using the oracle mechanism;
   417 for the SMT solver Z3, this method is proof-producing.  Certificates
   418 are provided to avoid calling the external solvers solely for
   419 re-checking proofs.  Due to a remote SMT service there is no need for
   420 installing SMT solvers locally.  See src/HOL/SMT.
   421 
   422 * New commands to load and prove verification conditions generated by
   423 the Boogie program verifier or derived systems (e.g. the Verifying C
   424 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   425 
   426 * New counterexample generator tool 'nitpick' based on the Kodkod
   427 relational model finder.  See src/HOL/Tools/Nitpick and
   428 src/HOL/Nitpick_Examples.
   429 
   430 * New commands 'code_pred' and 'values' to invoke the predicate
   431 compiler and to enumerate values of inductive predicates.
   432 
   433 * A tabled implementation of the reflexive transitive closure.
   434 
   435 * New implementation of quickcheck uses generic code generator;
   436 default generators are provided for all suitable HOL types, records
   437 and datatypes.  Old quickcheck can be re-activated importing theory
   438 Library/SML_Quickcheck.
   439 
   440 * New testing tool Mirabelle for automated proof tools.  Applies
   441 several tools and tactics like sledgehammer, metis, or quickcheck, to
   442 every proof step in a theory.  To be used in batch mode via the
   443 "mirabelle" utility.
   444 
   445 * New proof method "sos" (sum of squares) for nonlinear real
   446 arithmetic (originally due to John Harison). It requires theory
   447 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   448 works well in practice on quantifier-free real arithmetic with +, -,
   449 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   450 inequalities between polynomials.  It makes use of external
   451 semidefinite programming solvers.  Method "sos" generates a
   452 certificate that can be pasted into the proof thus avoiding the need
   453 to call an external tool every time the proof is checked.  See
   454 src/HOL/Library/Sum_Of_Squares.
   455 
   456 * New method "linarith" invokes existing linear arithmetic decision
   457 procedure only.
   458 
   459 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   460 
   461 * New Sledgehammer option "Full Types" in Proof General settings menu.
   462 Causes full type information to be output to the ATPs.  This slows
   463 ATPs down considerably but eliminates a source of unsound "proofs"
   464 that fail later.
   465 
   466 * New method "metisFT": A version of metis that uses full type
   467 information in order to avoid failures of proof reconstruction.
   468 
   469 * New evaluator "approximate" approximates an real valued term using
   470 the same method as the approximation method.
   471 
   472 * Method "approximate" now supports arithmetic expressions as
   473 boundaries of intervals and implements interval splitting and Taylor
   474 series expansion.
   475 
   476 * ML antiquotation @{code_datatype} inserts definition of a datatype
   477 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   478 
   479 * New theory SupInf of the supremum and infimum operators for sets of
   480 reals.
   481 
   482 * New theory Probability, which contains a development of measure
   483 theory, eventually leading to Lebesgue integration and probability.
   484 
   485 * Extended Multivariate Analysis to include derivation and Brouwer's
   486 fixpoint theorem.
   487 
   488 * Reorganization of number theory, INCOMPATIBILITY:
   489   - new number theory development for nat and int, in theories Divides
   490     and GCD as well as in new session Number_Theory
   491   - some constants and facts now suffixed with _nat and _int
   492     accordingly
   493   - former session NumberTheory now named Old_Number_Theory, including
   494     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   495   - moved theory Pocklington from src/HOL/Library to
   496     src/HOL/Old_Number_Theory
   497 
   498 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   499 lcm of finite and infinite sets. It is shown that they form a complete
   500 lattice.
   501 
   502 * Class semiring_div requires superclass no_zero_divisors and proof of
   503 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   504 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   505 generalized to class semiring_div, subsuming former theorems
   506 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   507 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   508 INCOMPATIBILITY.
   509 
   510 * Refinements to lattice classes and sets:
   511   - less default intro/elim rules in locale variant, more default
   512     intro/elim rules in class variant: more uniformity
   513   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   514     le_inf_iff
   515   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   516     sup_aci)
   517   - renamed ACI to inf_sup_aci
   518   - new class "boolean_algebra"
   519   - class "complete_lattice" moved to separate theory
   520     "Complete_Lattice"; corresponding constants (and abbreviations)
   521     renamed and with authentic syntax:
   522     Set.Inf ~>    Complete_Lattice.Inf
   523     Set.Sup ~>    Complete_Lattice.Sup
   524     Set.INFI ~>   Complete_Lattice.INFI
   525     Set.SUPR ~>   Complete_Lattice.SUPR
   526     Set.Inter ~>  Complete_Lattice.Inter
   527     Set.Union ~>  Complete_Lattice.Union
   528     Set.INTER ~>  Complete_Lattice.INTER
   529     Set.UNION ~>  Complete_Lattice.UNION
   530   - authentic syntax for
   531     Set.Pow
   532     Set.image
   533   - mere abbreviations:
   534     Set.empty               (for bot)
   535     Set.UNIV                (for top)
   536     Set.inter               (for inf, formerly Set.Int)
   537     Set.union               (for sup, formerly Set.Un)
   538     Complete_Lattice.Inter  (for Inf)
   539     Complete_Lattice.Union  (for Sup)
   540     Complete_Lattice.INTER  (for INFI)
   541     Complete_Lattice.UNION  (for SUPR)
   542   - object-logic definitions as far as appropriate
   543 
   544 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   545 Un_subset_iff are explicitly deleted as default simp rules; then also
   546 their lattice counterparts le_inf_iff and le_sup_iff have to be
   547 deleted to achieve the desired effect.
   548 
   549 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   550 rules by default any longer; the same applies to min_max.inf_absorb1
   551 etc.  INCOMPATIBILITY.
   552 
   553 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   554 pred_set_conv by default.  INCOMPATIBILITY.
   555 
   556 * Power operations on relations and functions are now one dedicated
   557 constant "compow" with infix syntax "^^".  Power operation on
   558 multiplicative monoids retains syntax "^" and is now defined generic
   559 in class power.  INCOMPATIBILITY.
   560 
   561 * Relation composition "R O S" now has a more standard argument order:
   562 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   563 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   564 break, since the O_assoc rule was not rewritten like this.  Fix using
   565 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   566 
   567 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   568 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   569 INCOMPATIBILITY.
   570 
   571 * Most rules produced by inductive and datatype package have mandatory
   572 prefixes.  INCOMPATIBILITY.
   573 
   574 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   575 the attribute of the same name.  Each of the theorems in the list
   576 DERIV_intros assumes composition with an additional function and
   577 matches a variable to the derivative, which has to be solved by the
   578 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   579 of most elementary terms.  Former Maclauren.DERIV_tac and
   580 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   581 INCOMPATIBILITY.
   582 
   583 * Code generator attributes follow the usual underscore convention:
   584     code_unfold     replaces    code unfold
   585     code_post       replaces    code post
   586     etc.
   587   INCOMPATIBILITY.
   588 
   589 * Renamed methods:
   590     sizechange -> size_change
   591     induct_scheme -> induction_schema
   592   INCOMPATIBILITY.
   593 
   594 * Discontinued abbreviation "arbitrary" of constant "undefined".
   595 INCOMPATIBILITY, use "undefined" directly.
   596 
   597 * Renamed theorems:
   598     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   599     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   600     Suc_plus1 -> Suc_eq_plus1
   601     *anti_sym -> *antisym*
   602     vector_less_eq_def -> vector_le_def
   603   INCOMPATIBILITY.
   604 
   605 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   606 INCOMPATIBILITY.
   607 
   608 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   609 INCOMPATIBILITY.
   610 
   611 
   612 *** HOLCF ***
   613 
   614 * Theory Representable defines a class "rep" of domains that are
   615 representable (via an ep-pair) in the universal domain type "udom".
   616 Instances are provided for all type constructors defined in HOLCF.
   617 
   618 * The 'new_domain' command is a purely definitional version of the
   619 domain package, for representable domains.  Syntax is identical to the
   620 old domain package.  The 'new_domain' package also supports indirect
   621 recursion using previously-defined type constructors.  See
   622 src/HOLCF/ex/New_Domain.thy for examples.
   623 
   624 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   625 on the left-hand side of an equation, and then performs
   626 simplification.  Rewriting is done using rules declared with the
   627 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   628 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   629 
   630 * The pattern-match compiler in 'fixrec' can now handle constructors
   631 with HOL function types.  Pattern-match combinators for the Pair
   632 constructor are pre-configured.
   633 
   634 * The 'fixrec' package now produces better fixed-point induction rules
   635 for mutually-recursive definitions:  Induction rules have conclusions
   636 of the form "P foo bar" instead of "P <foo, bar>".
   637 
   638 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   639 been renamed to "below".  The name "below" now replaces "less" in many
   640 theorem names.  (Legacy theorem names using "less" are still supported
   641 as well.)
   642 
   643 * The 'fixrec' package now supports "bottom patterns".  Bottom
   644 patterns can be used to generate strictness rules, or to make
   645 functions more strict (much like the bang-patterns supported by the
   646 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   647 examples.
   648 
   649 
   650 *** ML ***
   651 
   652 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   653 errors and run-time exceptions, including detailed source positions.
   654 
   655 * Structure Name_Space (formerly NameSpace) now manages uniquely
   656 identified entries, with some additional information such as source
   657 position, logical grouping etc.
   658 
   659 * Theory and context data is now introduced by the simplified and
   660 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   661 to be pure, but the old TheoryDataFun for mutable data (with explicit
   662 copy operation) is still available for some time.
   663 
   664 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   665 provides a high-level programming interface to synchronized state
   666 variables with atomic update.  This works via pure function
   667 application within a critical section -- its runtime should be as
   668 short as possible; beware of deadlocks if critical code is nested,
   669 either directly or indirectly via other synchronized variables!
   670 
   671 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   672 wraps raw ML references, explicitly indicating their non-thread-safe
   673 behaviour.  The Isar toplevel keeps this structure open, to
   674 accommodate Proof General as well as quick and dirty interactive
   675 experiments with references.
   676 
   677 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   678 parallel tactical reasoning.
   679 
   680 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   681 are similar to SUBPROOF, but are slightly more flexible: only the
   682 specified parts of the subgoal are imported into the context, and the
   683 body tactic may introduce new subgoals and schematic variables.
   684 
   685 * Old tactical METAHYPS, which does not observe the proof context, has
   686 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   687 or Subgoal.FOCUS etc.
   688 
   689 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   690 functors have their own ML name space there is no point to mark them
   691 separately.)  Minor INCOMPATIBILITY.
   692 
   693 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   694 
   695 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   696 INCOMPATIBILITY.
   697 
   698 * Operations of structure Skip_Proof no longer require quick_and_dirty
   699 mode, which avoids critical setmp.
   700 
   701 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   702 combinators for "args".  INCOMPATIBILITY, need to use simplified
   703 Attrib/Method.setup introduced in Isabelle2009.
   704 
   705 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   706 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   707 last resort.  INCOMPATIBILITY.
   708 
   709 * Display.pretty_thm now requires a proper context (cf. former
   710 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   711 or even Display.pretty_thm_without_context as last resort.
   712 INCOMPATIBILITY.
   713 
   714 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   715 Syntax.pretty_typ/term directly, preferably with proper context
   716 instead of global theory.
   717 
   718 
   719 *** System ***
   720 
   721 * Further fine tuning of parallel proof checking, scales up to 8 cores
   722 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   723 usedir option -q.
   724 
   725 * Support for additional "Isabelle components" via etc/components, see
   726 also the system manual.
   727 
   728 * The isabelle makeall tool now operates on all components with
   729 IsaMakefile, not just hardwired "logics".
   730 
   731 * Removed "compress" option from isabelle-process and isabelle usedir;
   732 this is always enabled.
   733 
   734 * Discontinued support for Poly/ML 4.x versions.
   735 
   736 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   737 on a given logic image.  This requires the lighttpd webserver and is
   738 currently supported on Linux only.
   739 
   740 
   741 
   742 New in Isabelle2009 (April 2009)
   743 --------------------------------
   744 
   745 *** General ***
   746 
   747 * Simplified main Isabelle executables, with less surprises on
   748 case-insensitive file-systems (such as Mac OS).
   749 
   750   - The main Isabelle tool wrapper is now called "isabelle" instead of
   751     "isatool."
   752 
   753   - The former "isabelle" alias for "isabelle-process" has been
   754     removed (should rarely occur to regular users).
   755 
   756   - The former "isabelle-interface" and its alias "Isabelle" have been
   757     removed (interfaces are now regular Isabelle tools).
   758 
   759 Within scripts and make files, the Isabelle environment variables
   760 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   761 respectively.  (The latter are still available as legacy feature.)
   762 
   763 The old isabelle-interface wrapper could react in confusing ways if
   764 the interface was uninstalled or changed otherwise.  Individual
   765 interface tool configuration is now more explicit, see also the
   766 Isabelle system manual.  In particular, Proof General is now available
   767 via "isabelle emacs".
   768 
   769 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   770 purge installed copies of Isabelle executables and re-run "isabelle
   771 install -p ...", or use symlinks.
   772 
   773 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   774 old ~/isabelle, which was slightly non-standard and apt to cause
   775 surprises on case-insensitive file-systems (such as Mac OS).
   776 
   777 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   778 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   779 care is required when using older releases of Isabelle.  Note that
   780 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   781 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   782 
   783 * Proofs of fully specified statements are run in parallel on
   784 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   785 a regular 4-core machine, if the initial heap space is made reasonably
   786 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   787 
   788 * The main reference manuals ("isar-ref", "implementation", and
   789 "system") have been updated and extended.  Formally checked references
   790 as hyperlinks are now available uniformly.
   791 
   792 
   793 *** Pure ***
   794 
   795 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   796 respects.  The most important changes are listed below.  See the
   797 Tutorial on Locales ("locales" manual) for details.
   798 
   799 - In locale expressions, instantiation replaces renaming.  Parameters
   800 must be declared in a for clause.  To aid compatibility with previous
   801 parameter inheritance, in locale declarations, parameters that are not
   802 'touched' (instantiation position "_" or omitted) are implicitly added
   803 with their syntax at the beginning of the for clause.
   804 
   805 - Syntax from abbreviations and definitions in locales is available in
   806 locale expressions and context elements.  The latter is particularly
   807 useful in locale declarations.
   808 
   809 - More flexible mechanisms to qualify names generated by locale
   810 expressions.  Qualifiers (prefixes) may be specified in locale
   811 expressions, and can be marked as mandatory (syntax: "name!:") or
   812 optional (syntax "name?:").  The default depends for plain "name:"
   813 depends on the situation where a locale expression is used: in
   814 commands 'locale' and 'sublocale' prefixes are optional, in
   815 'interpretation' and 'interpret' prefixes are mandatory.  The old
   816 implicit qualifiers derived from the parameter names of a locale are
   817 no longer generated.
   818 
   819 - Command "sublocale l < e" replaces "interpretation l < e".  The
   820 instantiation clause in "interpretation" and "interpret" (square
   821 brackets) is no longer available.  Use locale expressions.
   822 
   823 - When converting proof scripts, mandatory qualifiers in
   824 'interpretation' and 'interpret' should be retained by default, even
   825 if this is an INCOMPATIBILITY compared to former behavior.  In the
   826 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   827 in locale expressions range over a single locale instance only.
   828 
   829 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   830 In existing theorem specifications replace the includes element by the
   831 respective context elements of the included locale, omitting those
   832 that are already present in the theorem specification.  Multiple
   833 assume elements of a locale should be replaced by a single one
   834 involving the locale predicate.  In the proof body, declarations (most
   835 notably theorems) may be regained by interpreting the respective
   836 locales in the proof context as required (command "interpret").
   837 
   838 If using "includes" in replacement of a target solely because the
   839 parameter types in the theorem are not as general as in the target,
   840 consider declaring a new locale with additional type constraints on
   841 the parameters (context element "constrains").
   842 
   843 - Discontinued "locale (open)".  INCOMPATIBILITY.
   844 
   845 - Locale interpretation commands no longer attempt to simplify goal.
   846 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   847 methods intro_locales and unfold_locales to clarify.
   848 
   849 - Locale interpretation commands no longer accept interpretation
   850 attributes.  INCOMPATIBILITY.
   851 
   852 * Class declaration: so-called "base sort" must not be given in import
   853 list any longer, but is inferred from the specification.  Particularly
   854 in HOL, write
   855 
   856     class foo = ...
   857 
   858 instead of
   859 
   860     class foo = type + ...
   861 
   862 * Class target: global versions of theorems stemming do not carry a
   863 parameter prefix any longer.  INCOMPATIBILITY.
   864 
   865 * Class 'instance' command no longer accepts attached definitions.
   866 INCOMPATIBILITY, use proper 'instantiation' target instead.
   867 
   868 * Recovered hiding of consts, which was accidentally broken in
   869 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   870 makes c inaccessible; consider using ``hide (open) const c'' instead.
   871 
   872 * Slightly more coherent Pure syntax, with updated documentation in
   873 isar-ref manual.  Removed locales meta_term_syntax and
   874 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   875 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   876 directly in regular applications.
   877 
   878 * There is a new syntactic category "float_const" for signed decimal
   879 fractions (e.g. 123.45 or -123.45).
   880 
   881 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   882 interface with 'setup' command instead.
   883 
   884 * Command 'local_setup' is similar to 'setup', but operates on a local
   885 theory context.
   886 
   887 * The 'axiomatization' command now only works within a global theory
   888 context.  INCOMPATIBILITY.
   889 
   890 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   891 hypotheses.  Sorts required in the course of reasoning need to be
   892 covered by the constraints in the initial statement, completed by the
   893 type instance information of the background theory.  Non-trivial sort
   894 hypotheses, which rarely occur in practice, may be specified via
   895 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   896 
   897   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   898 
   899 The result contains an implicit sort hypotheses as before --
   900 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   901 normalization.
   902 
   903 * Generalized Isar history, with support for linear undo, direct state
   904 addressing etc.
   905 
   906 * Changed defaults for unify configuration options:
   907 
   908   unify_trace_bound = 50 (formerly 25)
   909   unify_search_bound = 60 (formerly 30)
   910 
   911 * Different bookkeeping for code equations (INCOMPATIBILITY):
   912 
   913   a) On theory merge, the last set of code equations for a particular
   914      constant is taken (in accordance with the policy applied by other
   915      parts of the code generator framework).
   916 
   917   b) Code equations stemming from explicit declarations (e.g. code
   918      attribute) gain priority over default code equations stemming
   919      from definition, primrec, fun etc.
   920 
   921 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   922 
   923 * Unified theorem tables for both code generators.  Thus [code
   924 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   925 
   926 * Command 'find_consts' searches for constants based on type and name
   927 patterns, e.g.
   928 
   929     find_consts "_ => bool"
   930 
   931 By default, matching is against subtypes, but it may be restricted to
   932 the whole type.  Searching by name is possible.  Multiple queries are
   933 conjunctive and queries may be negated by prefixing them with a
   934 hyphen:
   935 
   936     find_consts strict: "_ => bool" name: "Int" -"int => int"
   937 
   938 * New 'find_theorems' criterion "solves" matches theorems that
   939 directly solve the current goal (modulo higher-order unification).
   940 
   941 * Auto solve feature for main theorem statements: whenever a new goal
   942 is stated, "find_theorems solves" is called; any theorems that could
   943 solve the lemma directly are listed as part of the goal state.
   944 Cf. associated options in Proof General Isabelle settings menu,
   945 enabled by default, with reasonable timeout for pathological cases of
   946 higher-order unification.
   947 
   948 
   949 *** Document preparation ***
   950 
   951 * Antiquotation @{lemma} now imitates a regular terminal proof,
   952 demanding keyword 'by' and supporting the full method expression
   953 syntax just like the Isar command 'by'.
   954 
   955 
   956 *** HOL ***
   957 
   958 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   959 points Main and Complex_Main remain as before.
   960 
   961 * Logic image HOL-Plain provides a minimal HOL with the most important
   962 tools available (inductive, datatype, primrec, ...).  This facilitates
   963 experimentation and tool development.  Note that user applications
   964 (and library theories) should never refer to anything below theory
   965 Main, as before.
   966 
   967 * Logic image HOL-Main stops at theory Main, and thus facilitates
   968 experimentation due to shorter build times.
   969 
   970 * Logic image HOL-NSA contains theories of nonstandard analysis which
   971 were previously part of former HOL-Complex.  Entry point Hyperreal
   972 remains valid, but theories formerly using Complex_Main should now use
   973 new entry point Hypercomplex.
   974 
   975 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   976 Posix processes.  Avoids potentially expensive forking of the ML
   977 process.  New thread-based implementation also works on non-Unix
   978 platforms (Cygwin).  Provers are no longer hardwired, but defined
   979 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   980 commands are covered in the isar-ref manual.
   981 
   982 * Wrapper scripts for remote SystemOnTPTP service allows to use
   983 sledgehammer without local ATP installation (Vampire etc.). Other
   984 provers may be included via suitable ML wrappers, see also
   985 src/HOL/ATP_Linkup.thy.
   986 
   987 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   988 menu.
   989 
   990 * The metis method no longer fails because the theorem is too trivial
   991 (contains the empty clause).
   992 
   993 * The metis method now fails in the usual manner, rather than raising
   994 an exception, if it determines that it cannot prove the theorem.
   995 
   996 * Method "coherent" implements a prover for coherent logic (see also
   997 src/Tools/coherent.ML).
   998 
   999 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1000 "undefined" is the right choice to replace "arbitrary", though
  1001 logically there is no difference.  INCOMPATIBILITY.
  1002 
  1003 * Command "value" now integrates different evaluation mechanisms.  The
  1004 result of the first successful evaluation mechanism is printed.  In
  1005 square brackets a particular named evaluation mechanisms may be
  1006 specified (currently, [SML], [code] or [nbe]).  See further
  1007 src/HOL/ex/Eval_Examples.thy.
  1008 
  1009 * Normalization by evaluation now allows non-leftlinear equations.
  1010 Declare with attribute [code nbe].
  1011 
  1012 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1013 as the structured Isar versions "cases" and "induct", cf. the
  1014 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1015 are now presented as a list of individual projections
  1016 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1017 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1018 rare situations a different rule is selected --- notably nested tuple
  1019 elimination instead of former prod.exhaust: use explicit (case_tac t
  1020 rule: prod.exhaust) here.
  1021 
  1022 * Attributes "cases", "induct", "coinduct" support "del" option.
  1023 
  1024 * Removed fact "case_split_thm", which duplicates "case_split".
  1025 
  1026 * The option datatype has been moved to a new theory Option.  Renamed
  1027 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1028 
  1029 * New predicate "strict_mono" classifies strict functions on partial
  1030 orders.  With strict functions on linear orders, reasoning about
  1031 (in)equalities is facilitated by theorems "strict_mono_eq",
  1032 "strict_mono_less_eq" and "strict_mono_less".
  1033 
  1034 * Some set operations are now proper qualified constants with
  1035 authentic syntax.  INCOMPATIBILITY:
  1036 
  1037     op Int ~>   Set.Int
  1038     op Un ~>    Set.Un
  1039     INTER ~>    Set.INTER
  1040     UNION ~>    Set.UNION
  1041     Inter ~>    Set.Inter
  1042     Union ~>    Set.Union
  1043     {} ~>       Set.empty
  1044     UNIV ~>     Set.UNIV
  1045 
  1046 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1047 theory Set.
  1048 
  1049 * Auxiliary class "itself" has disappeared -- classes without any
  1050 parameter are treated as expected by the 'class' command.
  1051 
  1052 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1053 
  1054 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1055 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1056 
  1057 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1058 method "approximation".  It proves formulas on real values by using
  1059 interval arithmetic.  In the formulas are also the transcendental
  1060 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1061 allowed. For examples see
  1062 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1063 
  1064 * Theory "Reflection" now resides in HOL/Library.
  1065 
  1066 * Entry point to Word library now simply named "Word".
  1067 INCOMPATIBILITY.
  1068 
  1069 * Made source layout more coherent with logical distribution
  1070 structure:
  1071 
  1072     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1073     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1074     src/HOL/Library/GCD.thy ~> src/HOL/
  1075     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1076     src/HOL/Library/Parity.thy ~> src/HOL/
  1077     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1078     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1079     src/HOL/Real/Lubs.thy ~> src/HOL/
  1080     src/HOL/Real/PReal.thy ~> src/HOL/
  1081     src/HOL/Real/Rational.thy ~> src/HOL/
  1082     src/HOL/Real/RComplete.thy ~> src/HOL/
  1083     src/HOL/Real/RealDef.thy ~> src/HOL/
  1084     src/HOL/Real/RealPow.thy ~> src/HOL/
  1085     src/HOL/Real/Real.thy ~> src/HOL/
  1086     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1087     src/HOL/Complex/Complex.thy ~> src/HOL/
  1088     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1089     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1090     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1091     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1092     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1093     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1094     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1095     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1096     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1097     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1098     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1099     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1100     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1101     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1102     src/HOL/Real/Float ~> src/HOL/Library/
  1103     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1104     src/HOL/Real/RealVector.thy ~> src/HOL/
  1105 
  1106     src/HOL/arith_data.ML ~> src/HOL/Tools
  1107     src/HOL/hologic.ML ~> src/HOL/Tools
  1108     src/HOL/simpdata.ML ~> src/HOL/Tools
  1109     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1110     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1111     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1112     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1113     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1114     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1115     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1116 
  1117     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1118     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1119     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1120     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1121     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1122     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1123 
  1124 * If methods "eval" and "evaluation" encounter a structured proof
  1125 state with !!/==>, only the conclusion is evaluated to True (if
  1126 possible), avoiding strange error messages.
  1127 
  1128 * Method "sizechange" automates termination proofs using (a
  1129 modification of) the size-change principle.  Requires SAT solver.  See
  1130 src/HOL/ex/Termination.thy for examples.
  1131 
  1132 * Simplifier: simproc for let expressions now unfolds if bound
  1133 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1134 
  1135 * Method "arith": Linear arithmetic now ignores all inequalities when
  1136 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1137 
  1138 * New attribute "arith" for facts that should always be used
  1139 automatically by arithmetic. It is intended to be used locally in
  1140 proofs, e.g.
  1141 
  1142   assumes [arith]: "x > 0"
  1143 
  1144 Global usage is discouraged because of possible performance impact.
  1145 
  1146 * New classes "top" and "bot" with corresponding operations "top" and
  1147 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1148 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1149 
  1150 * Changed definition lemma "less_fun_def" in order to provide an
  1151 instance for preorders on functions; use lemma "less_le" instead.
  1152 INCOMPATIBILITY.
  1153 
  1154 * Theory Orderings: class "wellorder" moved here, with explicit
  1155 induction rule "less_induct" as assumption.  For instantiation of
  1156 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1157 INCOMPATIBILITY.
  1158 
  1159 * Theory Orderings: added class "preorder" as superclass of "order".
  1160 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1161 etc. slightly changed.  Some theorems named order_class.* now named
  1162 preorder_class.*.
  1163 
  1164 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1165 "diag" to "Id_on".
  1166 
  1167 * Theory Finite_Set: added a new fold combinator of type
  1168 
  1169   ('a => 'b => 'b) => 'b => 'a set => 'b
  1170 
  1171 Occasionally this is more convenient than the old fold combinator
  1172 which is now defined in terms of the new one and renamed to
  1173 fold_image.
  1174 
  1175 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1176 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1177 extended with further lemmas!).  At the moment both still exist but
  1178 the former will disappear at some point.
  1179 
  1180 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1181 class recpower.  Type-specific simp rules for various recpower types
  1182 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1183 
  1184 rat_power_0    -> power_0
  1185 rat_power_Suc  -> power_Suc
  1186 realpow_0      -> power_0
  1187 realpow_Suc    -> power_Suc
  1188 complexpow_0   -> power_0
  1189 complexpow_Suc -> power_Suc
  1190 power_poly_0   -> power_0
  1191 power_poly_Suc -> power_Suc
  1192 
  1193 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1194 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1195 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1196 of lemmas from Divides has been generalized from nat to class
  1197 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1198 renames resulting from duplicate elimination:
  1199 
  1200     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1201     zero_dvd_iff ~>         dvd_0_left_iff
  1202     dvd_0 ~>                dvd_0_right
  1203     DIVISION_BY_ZERO_DIV ~> div_by_0
  1204     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1205     mult_div ~>             div_mult_self2_is_id
  1206     mult_mod ~>             mod_mult_self2_is_0
  1207 
  1208 * Theory IntDiv: removed many lemmas that are instances of class-based
  1209 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1210 rename old lemmas as follows:
  1211 
  1212 dvd_diff               -> nat_dvd_diff
  1213 dvd_zminus_iff         -> dvd_minus_iff
  1214 mod_add1_eq            -> mod_add_eq
  1215 mod_mult1_eq           -> mod_mult_right_eq
  1216 mod_mult1_eq'          -> mod_mult_left_eq
  1217 mod_mult_distrib_mod   -> mod_mult_eq
  1218 nat_mod_add_left_eq    -> mod_add_left_eq
  1219 nat_mod_add_right_eq   -> mod_add_right_eq
  1220 nat_mod_div_trivial    -> mod_div_trivial
  1221 nat_mod_mod_trivial    -> mod_mod_trivial
  1222 zdiv_zadd_self1        -> div_add_self1
  1223 zdiv_zadd_self2        -> div_add_self2
  1224 zdiv_zmult_self1       -> div_mult_self2_is_id
  1225 zdiv_zmult_self2       -> div_mult_self1_is_id
  1226 zdvd_triv_left         -> dvd_triv_left
  1227 zdvd_triv_right        -> dvd_triv_right
  1228 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1229 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1230 zmod_zadd_left_eq      -> mod_add_left_eq
  1231 zmod_zadd_right_eq     -> mod_add_right_eq
  1232 zmod_zadd_self1        -> mod_add_self1
  1233 zmod_zadd_self2        -> mod_add_self2
  1234 zmod_zadd1_eq          -> mod_add_eq
  1235 zmod_zdiff1_eq         -> mod_diff_eq
  1236 zmod_zdvd_zmod         -> mod_mod_cancel
  1237 zmod_zmod_cancel       -> mod_mod_cancel
  1238 zmod_zmult_self1       -> mod_mult_self2_is_0
  1239 zmod_zmult_self2       -> mod_mult_self1_is_0
  1240 zmod_1                 -> mod_by_1
  1241 zdiv_1                 -> div_by_1
  1242 zdvd_abs1              -> abs_dvd_iff
  1243 zdvd_abs2              -> dvd_abs_iff
  1244 zdvd_refl              -> dvd_refl
  1245 zdvd_trans             -> dvd_trans
  1246 zdvd_zadd              -> dvd_add
  1247 zdvd_zdiff             -> dvd_diff
  1248 zdvd_zminus_iff        -> dvd_minus_iff
  1249 zdvd_zminus2_iff       -> minus_dvd_iff
  1250 zdvd_zmultD            -> dvd_mult_right
  1251 zdvd_zmultD2           -> dvd_mult_left
  1252 zdvd_zmult_mono        -> mult_dvd_mono
  1253 zdvd_0_right           -> dvd_0_right
  1254 zdvd_0_left            -> dvd_0_left_iff
  1255 zdvd_1_left            -> one_dvd
  1256 zminus_dvd_iff         -> minus_dvd_iff
  1257 
  1258 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1259 
  1260 * The real numbers offer decimal input syntax: 12.34 is translated
  1261 into 1234/10^2. This translation is not reversed upon output.
  1262 
  1263 * Theory Library/Polynomial defines an abstract type 'a poly of
  1264 univariate polynomials with coefficients of type 'a.  In addition to
  1265 the standard ring operations, it also supports div and mod.  Code
  1266 generation is also supported, using list-style constructors.
  1267 
  1268 * Theory Library/Inner_Product defines a class of real_inner for real
  1269 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1270 => real.  Class real_inner is a subclass of real_normed_vector from
  1271 theory RealVector.
  1272 
  1273 * Theory Library/Product_Vector provides instances for the product
  1274 type 'a * 'b of several classes from RealVector and Inner_Product.
  1275 Definitions of addition, subtraction, scalar multiplication, norms,
  1276 and inner products are included.
  1277 
  1278 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1279 addition to the field operations, numerals and case syntax are also
  1280 supported.
  1281 
  1282 * Theory Library/Diagonalize provides constructive version of Cantor's
  1283 first diagonalization argument.
  1284 
  1285 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1286 zlcm (for int); carried together from various gcd/lcm developements in
  1287 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1288 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1289 may recover tupled syntax as follows:
  1290 
  1291     hide (open) const gcd
  1292     abbreviation gcd where
  1293       "gcd == (%(a, b). GCD.gcd a b)"
  1294     notation (output)
  1295       GCD.gcd ("gcd '(_, _')")
  1296 
  1297 The same works for lcm, zgcd, zlcm.
  1298 
  1299 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1300 instantiations for algebraic structures.  Removed some duplicate
  1301 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1302 
  1303 * ML antiquotation @{code} takes a constant as argument and generates
  1304 corresponding code in background and inserts name of the corresponding
  1305 resulting ML value/function/datatype constructor binding in place.
  1306 All occurrences of @{code} with a single ML block are generated
  1307 simultaneously.  Provides a generic and safe interface for
  1308 instrumentalizing code generation.  See
  1309 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1310 In future you ought to refrain from ad-hoc compiling generated SML
  1311 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1312 cannot refer to constants for which user-defined serializations are
  1313 set.  Refer to the corresponding ML counterpart directly in that
  1314 cases.
  1315 
  1316 * Command 'rep_datatype': instead of theorem names the command now
  1317 takes a list of terms denoting the constructors of the type to be
  1318 represented as datatype.  The characteristic theorems have to be
  1319 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1320 have disappeared in favour of existing ones:
  1321 
  1322     unit_induct                 ~> unit.induct
  1323     prod_induct                 ~> prod.induct
  1324     sum_induct                  ~> sum.induct
  1325     Suc_Suc_eq                  ~> nat.inject
  1326     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1327 
  1328 
  1329 *** HOL-Algebra ***
  1330 
  1331 * New locales for orders and lattices where the equivalence relation
  1332 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1333 locales use a record structure with field eq for the equivalence.
  1334 
  1335 * New theory of factorial domains.
  1336 
  1337 * Units_l_inv and Units_r_inv are now simp rules by default.
  1338 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1339 and/or r_inv will now also require deletion of these lemmas.
  1340 
  1341 * Renamed the following theorems, INCOMPATIBILITY:
  1342 
  1343 UpperD ~> Upper_memD
  1344 LowerD ~> Lower_memD
  1345 least_carrier ~> least_closed
  1346 greatest_carrier ~> greatest_closed
  1347 greatest_Lower_above ~> greatest_Lower_below
  1348 one_zero ~> carrier_one_zero
  1349 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1350 
  1351 
  1352 *** HOL-Nominal ***
  1353 
  1354 * Nominal datatypes can now contain type-variables.
  1355 
  1356 * Commands 'nominal_inductive' and 'equivariance' work with local
  1357 theory targets.
  1358 
  1359 * Nominal primrec can now works with local theory targets and its
  1360 specification syntax now conforms to the general format as seen in
  1361 'inductive' etc.
  1362 
  1363 * Method "perm_simp" honours the standard simplifier attributes
  1364 (no_asm), (no_asm_use) etc.
  1365 
  1366 * The new predicate #* is defined like freshness, except that on the
  1367 left hand side can be a set or list of atoms.
  1368 
  1369 * Experimental command 'nominal_inductive2' derives strong induction
  1370 principles for inductive definitions.  In contrast to
  1371 'nominal_inductive', which can only deal with a fixed number of
  1372 binders, it can deal with arbitrary expressions standing for sets of
  1373 atoms to be avoided.  The only inductive definition we have at the
  1374 moment that needs this generalisation is the typing rule for Lets in
  1375 the algorithm W:
  1376 
  1377  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1378  -----------------------------------------------------------------
  1379          Gamma |- Let x be t1 in t2 : T2
  1380 
  1381 In this rule one wants to avoid all the binders that are introduced by
  1382 "close Gamma T1".  We are looking for other examples where this
  1383 feature might be useful.  Please let us know.
  1384 
  1385 
  1386 *** HOLCF ***
  1387 
  1388 * Reimplemented the simplification procedure for proving continuity
  1389 subgoals.  The new simproc is extensible; users can declare additional
  1390 continuity introduction rules with the attribute [cont2cont].
  1391 
  1392 * The continuity simproc now uses a different introduction rule for
  1393 solving continuity subgoals on terms with lambda abstractions.  In
  1394 some rare cases the new simproc may fail to solve subgoals that the
  1395 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1396 Potential INCOMPATIBILITY.
  1397 
  1398 * Command 'fixrec': specification syntax now conforms to the general
  1399 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1400 examples.  INCOMPATIBILITY.
  1401 
  1402 
  1403 *** ZF ***
  1404 
  1405 * Proof of Zorn's Lemma for partial orders.
  1406 
  1407 
  1408 *** ML ***
  1409 
  1410 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1411 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1412 depends on multithreading, so timouts will not work before Poly/ML
  1413 5.2.1!
  1414 
  1415 * High-level support for concurrent ML programming, see
  1416 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1417 particularly convenient to organize independent functional
  1418 computations.  The concept of "synchronized variables" provides a
  1419 higher-order interface for components with shared state, avoiding the
  1420 delicate details of mutexes and condition variables.  (Requires
  1421 Poly/ML 5.2.1 or later.)
  1422 
  1423 * ML bindings produced via Isar commands are stored within the Isar
  1424 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1425 become thread-safe and work with undo as expected (concerning
  1426 top-level bindings, not side-effects on global references).
  1427 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1428 compiler at runtime; really global bindings need to be given outside a
  1429 theory.  (Requires Poly/ML 5.2 or later.)
  1430 
  1431 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1432 context.  Top-level ML bindings are stored within the proof context in
  1433 a purely sequential fashion, disregarding the nested proof structure.
  1434 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1435 proof.  (Requires Poly/ML 5.2 or later.)
  1436 
  1437 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1438 and Method.setup, as well as Isar commands 'attribute_setup' and
  1439 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1440 existing code accordingly, or use plain 'setup' together with old
  1441 Method.add_method.
  1442 
  1443 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1444 to 'a -> thm, while results are always tagged with an authentic oracle
  1445 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1446 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1447 accordingly.  Note that extra performance may be gained by producing
  1448 the cterm carefully, avoiding slow Thm.cterm_of.
  1449 
  1450 * Simplified interface for defining document antiquotations via
  1451 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1452 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1453 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1454 examples.
  1455 
  1456 * More systematic treatment of long names, abstract name bindings, and
  1457 name space operations.  Basic operations on qualified names have been
  1458 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1459 Long_Name.append.  Old type bstring has been mostly replaced by
  1460 abstract type binding (see structure Binding), which supports precise
  1461 qualification by packages and local theory targets, as well as proper
  1462 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1463 bstring values into Binding.name, or better pass through abstract
  1464 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1465 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1466 
  1467 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1468 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1469 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1470 
  1471 * Disposed old type and term read functions (Sign.read_def_typ,
  1472 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1473 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1474 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1475 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1476 resort for legacy applications.
  1477 
  1478 * Disposed old declarations, tactics, tactic combinators that refer to
  1479 the simpset or claset of an implicit theory (such as Addsimps,
  1480 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1481 embedded ML text, or local_simpset_of with a proper context passed as
  1482 explicit runtime argument.
  1483 
  1484 * Rules and tactics that read instantiations (read_instantiate,
  1485 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1486 context, which is required for parsing and type-checking.  Moreover,
  1487 the variables are specified as plain indexnames, not string encodings
  1488 thereof.  INCOMPATIBILITY.
  1489 
  1490 * Generic Toplevel.add_hook interface allows to analyze the result of
  1491 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1492 for theorem dependency output of transactions resulting in a new
  1493 theory state.
  1494 
  1495 * ML antiquotations: block-structured compilation context indicated by
  1496 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1497 
  1498   @{binding name}                         - basic name binding
  1499   @{let ?pat = term}                      - term abbreviation (HO matching)
  1500   @{note name = fact}                     - fact abbreviation
  1501   @{thm fact}                             - singleton fact (with attributes)
  1502   @{thms fact}                            - general fact (with attributes)
  1503   @{lemma prop by method}                 - singleton goal
  1504   @{lemma prop by meth1 meth2}            - singleton goal
  1505   @{lemma prop1 ... propN by method}      - general goal
  1506   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1507   @{lemma (open) ...}                     - open derivation
  1508 
  1509 
  1510 *** System ***
  1511 
  1512 * The Isabelle "emacs" tool provides a specific interface to invoke
  1513 Proof General / Emacs, with more explicit failure if that is not
  1514 installed (the old isabelle-interface script silently falls back on
  1515 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1516 installation location of the Proof General distribution.
  1517 
  1518 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1519 the Isabelle process into a JVM/Scala application.  See
  1520 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1521 process wrapper has been discontinued.)
  1522 
  1523 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1524 
  1525 * Various status messages (with exact source position information) are
  1526 emitted, if proper markup print mode is enabled.  This allows
  1527 user-interface components to provide detailed feedback on internal
  1528 prover operations.
  1529 
  1530 
  1531 
  1532 New in Isabelle2008 (June 2008)
  1533 -------------------------------
  1534 
  1535 *** General ***
  1536 
  1537 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1538 and updated, with formally checked references as hyperlinks.
  1539 
  1540 * Theory loader: use_thy (and similar operations) no longer set the
  1541 implicit ML context, which was occasionally hard to predict and in
  1542 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1543 provides a proper context already.
  1544 
  1545 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1546 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1547 'use' within a theory file will do the job.
  1548 
  1549 * Name space merge now observes canonical order, i.e. the second space
  1550 is inserted into the first one, while existing entries in the first
  1551 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1552 swap theory imports.
  1553 
  1554 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1555 INCOMPATIBILITY in identifier syntax etc.
  1556 
  1557 * Outer syntax: string tokens no longer admit escaped white space,
  1558 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1559 white space without escapes.
  1560 
  1561 * Outer syntax: string tokens may contain arbitrary character codes
  1562 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1563 "foo_bar".
  1564 
  1565 
  1566 *** Pure ***
  1567 
  1568 * Context-dependent token translations.  Default setup reverts locally
  1569 fixed variables, and adds hilite markup for undeclared frees.
  1570 
  1571 * Unused theorems can be found using the new command 'unused_thms'.
  1572 There are three ways of invoking it:
  1573 
  1574 (1) unused_thms
  1575      Only finds unused theorems in the current theory.
  1576 
  1577 (2) unused_thms thy_1 ... thy_n -
  1578      Finds unused theorems in the current theory and all of its ancestors,
  1579      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1580 
  1581 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1582      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1583      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1584      their ancestors.
  1585 
  1586 In order to increase the readability of the list produced by
  1587 unused_thms, theorems that have been created by a particular instance
  1588 of a theory command such as 'inductive' or 'function' are considered
  1589 to belong to the same "group", meaning that if at least one theorem in
  1590 this group is used, the other theorems in the same group are no longer
  1591 reported as unused.  Moreover, if all theorems in the group are
  1592 unused, only one theorem in the group is displayed.
  1593 
  1594 Note that proof objects have to be switched on in order for
  1595 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1596 usually the case when using Proof General with the default settings).
  1597 
  1598 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1599 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1600 duplicate fact bindings, or even accidental fact duplications.  Note
  1601 that tools may maintain dynamically scoped facts systematically, using
  1602 PureThy.add_thms_dynamic.
  1603 
  1604 * Command 'hide' now allows to hide from "fact" name space as well.
  1605 
  1606 * Eliminated destructive theorem database, simpset, claset, and
  1607 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1608 update of theories within ML code.
  1609 
  1610 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1611 INCOMPATIBILITY, object-logics depending on former Pure require
  1612 additional setup PureThy.old_appl_syntax_setup; object-logics
  1613 depending on former CPure need to refer to Pure.
  1614 
  1615 * Commands 'use' and 'ML' are now purely functional, operating on
  1616 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1617 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1618 INCOMPATIBILITY.
  1619 
  1620 * Command 'setup': discontinued implicit version with ML reference.
  1621 
  1622 * Instantiation target allows for simultaneous specification of class
  1623 instance operations together with an instantiation proof.
  1624 Type-checking phase allows to refer to class operations uniformly.
  1625 See src/HOL/Complex/Complex.thy for an Isar example and
  1626 src/HOL/Library/Eval.thy for an ML example.
  1627 
  1628 * Indexing of literal facts: be more serious about including only
  1629 facts from the visible specification/proof context, but not the
  1630 background context (locale etc.).  Affects `prop` notation and method
  1631 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1632 situations.
  1633 
  1634 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1635 "(open)" option, which used to expose internal bound variables to the
  1636 proof text.
  1637 
  1638 * Isar statements: removed obsolete case "rule_context".
  1639 INCOMPATIBILITY, better use explicit fixes/assumes.
  1640 
  1641 * Locale proofs: default proof step now includes 'unfold_locales';
  1642 hence 'proof' without argument may be used to unfold locale
  1643 predicates.
  1644 
  1645 
  1646 *** Document preparation ***
  1647 
  1648 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1649 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1650 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1651 spot); renamed link color from "darkblue" to "linkcolor" (default
  1652 value unchanged, can be redefined via \definecolor); no longer sets
  1653 "a4paper" option (unnecessary or even intrusive).
  1654 
  1655 * Antiquotation @{lemma A method} proves proposition A by the given
  1656 method (either a method name or a method name plus (optional) method
  1657 arguments in parentheses) and prints A just like @{prop A}.
  1658 
  1659 
  1660 *** HOL ***
  1661 
  1662 * New primrec package.  Specification syntax conforms in style to
  1663 definition/function/....  No separate induction rule is provided.  The
  1664 "primrec" command distinguishes old-style and new-style specifications
  1665 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1666 When adjusting theories, beware: constants stemming from new-style
  1667 primrec specifications have authentic syntax.
  1668 
  1669 * Metis prover is now an order of magnitude faster, and also works
  1670 with multithreading.
  1671 
  1672 * Metis: the maximum number of clauses that can be produced from a
  1673 theorem is now given by the attribute max_clauses.  Theorems that
  1674 exceed this number are ignored, with a warning printed.
  1675 
  1676 * Sledgehammer no longer produces structured proofs by default. To
  1677 enable, declare [[sledgehammer_full = true]].  Attributes
  1678 reconstruction_modulus, reconstruction_sorts renamed
  1679 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1680 
  1681 * Method "induct_scheme" derives user-specified induction rules
  1682 from well-founded induction and completeness of patterns. This factors
  1683 out some operations that are done internally by the function package
  1684 and makes them available separately.  See
  1685 src/HOL/ex/Induction_Scheme.thy for examples.
  1686 
  1687 * More flexible generation of measure functions for termination
  1688 proofs: Measure functions can be declared by proving a rule of the
  1689 form "is_measure f" and giving it the [measure_function] attribute.
  1690 The "is_measure" predicate is logically meaningless (always true), and
  1691 just guides the heuristic.  To find suitable measure functions, the
  1692 termination prover sets up the goal "is_measure ?f" of the appropriate
  1693 type and generates all solutions by prolog-style backwards proof using
  1694 the declared rules.
  1695 
  1696 This setup also deals with rules like 
  1697 
  1698   "is_measure f ==> is_measure (list_size f)"
  1699 
  1700 which accommodates nested datatypes that recurse through lists.
  1701 Similar rules are predeclared for products and option types.
  1702 
  1703 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1704 
  1705   INCOMPATIBILITIES:
  1706 
  1707   - Definitions of overloaded constants on sets have to be replaced by
  1708     definitions on => and bool.
  1709 
  1710   - Some definitions of overloaded operators on sets can now be proved
  1711     using the definitions of the operators on => and bool.  Therefore,
  1712     the following theorems have been renamed:
  1713 
  1714       subset_def   -> subset_eq
  1715       psubset_def  -> psubset_eq
  1716       set_diff_def -> set_diff_eq
  1717       Compl_def    -> Compl_eq
  1718       Sup_set_def  -> Sup_set_eq
  1719       Inf_set_def  -> Inf_set_eq
  1720       sup_set_def  -> sup_set_eq
  1721       inf_set_def  -> inf_set_eq
  1722 
  1723   - Due to the incompleteness of the HO unification algorithm, some
  1724     rules such as subst may require manual instantiation, if some of
  1725     the unknowns in the rule is a set.
  1726 
  1727   - Higher order unification and forward proofs:
  1728     The proof pattern
  1729 
  1730       have "P (S::'a set)" <...>
  1731       then have "EX S. P S" ..
  1732 
  1733     no longer works (due to the incompleteness of the HO unification
  1734     algorithm) and must be replaced by the pattern
  1735 
  1736       have "EX S. P S"
  1737       proof
  1738         show "P S" <...>
  1739       qed
  1740 
  1741   - Calculational reasoning with subst (or similar rules):
  1742     The proof pattern
  1743 
  1744       have "P (S::'a set)" <...>
  1745       also have "S = T" <...>
  1746       finally have "P T" .
  1747 
  1748     no longer works (for similar reasons as the previous example) and
  1749     must be replaced by something like
  1750 
  1751       have "P (S::'a set)" <...>
  1752       moreover have "S = T" <...>
  1753       ultimately have "P T" by simp
  1754 
  1755   - Tactics or packages written in ML code:
  1756     Code performing pattern matching on types via
  1757 
  1758       Type ("set", [T]) => ...
  1759 
  1760     must be rewritten. Moreover, functions like strip_type or
  1761     binder_types no longer return the right value when applied to a
  1762     type of the form
  1763 
  1764       T1 => ... => Tn => U => bool
  1765 
  1766     rather than
  1767 
  1768       T1 => ... => Tn => U set
  1769 
  1770 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1771 Wellfounded_Relations to theory Wellfounded.
  1772 
  1773 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1774 
  1775 * Class finite no longer treats UNIV as class parameter.  Use class
  1776 enum from theory Library/Enum instead to achieve a similar effect.
  1777 INCOMPATIBILITY.
  1778 
  1779 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1780 and "Cons".  INCOMPATIBILITY.
  1781 
  1782 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1783 Potential INCOMPATIBILITY.
  1784 
  1785 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1786 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1787 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1788 
  1789 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1790 the same name in theory Orderings:
  1791 
  1792   less_trans
  1793   less_linear
  1794   le_imp_less_or_eq
  1795   le_less_trans
  1796   less_le_trans
  1797   less_not_sym
  1798   less_asym
  1799 
  1800 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1801 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1802 and different variable names.
  1803 
  1804 * Library/Option_ord.thy: Canonical order on option type.
  1805 
  1806 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1807 finite maps.
  1808 
  1809 * Library/Countable.thy: Type class for countable types.
  1810 
  1811 * Theory Int: The representation of numerals has changed.  The infix
  1812 operator BIT and the bit datatype with constructors B0 and B1 have
  1813 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1814 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1815 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1816 accordingly.
  1817 
  1818 * Theory Nat: definition of <= and < on natural numbers no longer
  1819 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1820 le_def and less_def have disappeared.  Consider lemmas not_less
  1821 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1822 
  1823 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1824 (whose purpose mainly is for various fold_set functionals) have been
  1825 abandoned in favor of the existing algebraic classes
  1826 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1827 lower_semilattice (resp. upper_semilattice) and linorder.
  1828 INCOMPATIBILITY.
  1829 
  1830 * Theory Transitive_Closure: induct and cases rules now declare proper
  1831 case_names ("base" and "step").  INCOMPATIBILITY.
  1832 
  1833 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1834 lattices.  The form set-specific version is available as
  1835 Inductive.lfp_ordinal_induct_set.
  1836 
  1837 * Renamed theorems "power.simps" to "power_int.simps".
  1838 INCOMPATIBILITY.
  1839 
  1840 * Class semiring_div provides basic abstract properties of semirings
  1841 with division and modulo operations.  Subsumes former class dvd_mod.
  1842 
  1843 * Merged theories IntDef, Numeral and IntArith into unified theory
  1844 Int.  INCOMPATIBILITY.
  1845 
  1846 * Theory Library/Code_Index: type "index" now represents natural
  1847 numbers rather than integers.  INCOMPATIBILITY.
  1848 
  1849 * New class "uminus" with operation "uminus" (split of from class
  1850 "minus" which now only has operation "minus", binary).
  1851 INCOMPATIBILITY.
  1852 
  1853 * Constants "card", "internal_split", "option_map" now with authentic
  1854 syntax.  INCOMPATIBILITY.
  1855 
  1856 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1857 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1858 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1859 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1860 Sup_set_def, le_def, less_def, option_map_def now with object
  1861 equality.  INCOMPATIBILITY.
  1862 
  1863 * Records. Removed K_record, and replaced it by pure lambda term
  1864 %x. c. The simplifier setup is now more robust against eta expansion.
  1865 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1866 
  1867 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1868 
  1869 * Library/ListVector: new theory of arithmetic vector operations.
  1870 
  1871 * Library/Order_Relation: new theory of various orderings as sets of
  1872 pairs.  Defines preorders, partial orders, linear orders and
  1873 well-orders on sets and on types.
  1874 
  1875 
  1876 *** ZF ***
  1877 
  1878 * Renamed some theories to allow to loading both ZF and HOL in the
  1879 same session:
  1880 
  1881   Datatype  -> Datatype_ZF
  1882   Inductive -> Inductive_ZF
  1883   Int       -> Int_ZF
  1884   IntDiv    -> IntDiv_ZF
  1885   Nat       -> Nat_ZF
  1886   List      -> List_ZF
  1887   Main      -> Main_ZF
  1888 
  1889 INCOMPATIBILITY: ZF theories that import individual theories below
  1890 Main might need to be adapted.  Regular theory Main is still
  1891 available, as trivial extension of Main_ZF.
  1892 
  1893 
  1894 *** ML ***
  1895 
  1896 * ML within Isar: antiquotation @{const name} or @{const
  1897 name(typargs)} produces statically-checked Const term.
  1898 
  1899 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1900 (of the same name).  Removed obsolete print command.
  1901 
  1902 * Removed obsolete "use_legacy_bindings" function.
  1903 
  1904 * The ``print mode'' is now a thread-local value derived from a global
  1905 template (the former print_mode reference), thus access becomes
  1906 non-critical.  The global print_mode reference is for session
  1907 management only; user-code should use print_mode_value,
  1908 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1909 
  1910 * Functions system/system_out provide a robust way to invoke external
  1911 shell commands, with propagation of interrupts (requires Poly/ML
  1912 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1913 
  1914 
  1915 *** System ***
  1916 
  1917 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1918 in accordance with Proof General 3.7, which prefers GNU emacs.
  1919 
  1920 * isatool tty runs Isabelle process with plain tty interaction;
  1921 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1922 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1923 
  1924 * isatool browser now works with Cygwin as well, using general
  1925 "javapath" function defined in Isabelle process environment.
  1926 
  1927 * YXML notation provides a simple and efficient alternative to
  1928 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1929 isatool yxml as described in the Isabelle system manual.
  1930 
  1931 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1932 provides general wrapper for managing an Isabelle process in a robust
  1933 fashion, with ``cooked'' output from stdin/stderr.
  1934 
  1935 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1936 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1937 
  1938 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1939 way of changing the user's settings is via
  1940 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1941 script.
  1942 
  1943 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1944 cores of the underlying machine, which is a good starting point for
  1945 optimal performance tuning.  The corresponding usedir option -M allows
  1946 "max" as an alias for "0".  WARNING: does not work on certain versions
  1947 of Mac OS (with Poly/ML 5.1).
  1948 
  1949 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1950 adverse effect of Isabelle flooding interactive front-ends (notably
  1951 ProofGeneral / XEmacs).
  1952 
  1953 
  1954 
  1955 New in Isabelle2007 (November 2007)
  1956 -----------------------------------
  1957 
  1958 *** General ***
  1959 
  1960 * More uniform information about legacy features, notably a
  1961 warning/error of "Legacy feature: ...", depending on the state of the
  1962 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1963 legacy features will disappear eventually.
  1964 
  1965 * Theory syntax: the header format ``theory A = B + C:'' has been
  1966 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1967 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1968 
  1969 * Theory syntax: the old non-Isar theory file format has been
  1970 discontinued altogether.  Note that ML proof scripts may still be used
  1971 with Isar theories; migration is usually quite simple with the ML
  1972 function use_legacy_bindings.  INCOMPATIBILITY.
  1973 
  1974 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1975 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1976 quotes.
  1977 
  1978 * Theory loader: be more serious about observing the static theory
  1979 header specifications (including optional directories), but not the
  1980 accidental file locations of previously successful loads.  The strict
  1981 update policy of former update_thy is now already performed by
  1982 use_thy, so the former has been removed; use_thys updates several
  1983 theories simultaneously, just as 'imports' within a theory header
  1984 specification, but without merging the results.  Potential
  1985 INCOMPATIBILITY: may need to refine theory headers and commands
  1986 ROOT.ML which depend on load order.
  1987 
  1988 * Theory loader: optional support for content-based file
  1989 identification, instead of the traditional scheme of full physical
  1990 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1991 (cf. the system manual).  The new scheme allows to work with
  1992 non-finished theories in persistent session images, such that source
  1993 files may be moved later on without requiring reloads.
  1994 
  1995 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1996 file (with the same base name as the theory) are considered a legacy
  1997 feature, which will disappear eventually. Even now, the theory loader
  1998 no longer maintains dependencies on such files.
  1999 
  2000 * Syntax: the scope for resolving ambiguities via type-inference is
  2001 now limited to individual terms, instead of whole simultaneous
  2002 specifications as before. This greatly reduces the complexity of the
  2003 syntax module and improves flexibility by separating parsing and
  2004 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2005 'fixes' etc.) are required in rare situations.
  2006 
  2007 * Syntax: constants introduced by new-style packages ('definition',
  2008 'abbreviation' etc.) are passed through the syntax module in
  2009 ``authentic mode''. This means that associated mixfix annotations
  2010 really stick to such constants, independently of potential name space
  2011 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2012 trees are represented slightly differently, may need to adapt syntax
  2013 translations accordingly. Use CONST marker in 'translations' and
  2014 @{const_syntax} antiquotation in 'parse_translation' etc.
  2015 
  2016 * Legacy goal package: reduced interface to the bare minimum required
  2017 to keep existing proof scripts running.  Most other user-level
  2018 functions are now part of the OldGoals structure, which is *not* open
  2019 by default (consider isatool expandshort before open OldGoals).
  2020 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2021 these tend to cause confusion about the actual goal (!) context being
  2022 used here, which is not necessarily the same as the_context().
  2023 
  2024 * Command 'find_theorems': supports "*" wild-card in "name:"
  2025 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2026 support a specific search form (see ProofGeneral/CHANGES).
  2027 
  2028 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2029 by default, which means that "prems" (and also "fixed variables") are
  2030 suppressed from proof state output.  Note that the ProofGeneral
  2031 settings mechanism allows to change and save options persistently, but
  2032 older versions of Isabelle will fail to start up if a negative prems
  2033 limit is imposed.
  2034 
  2035 * Local theory targets may be specified by non-nested blocks of
  2036 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2037 contain definitions, theorems etc., including any derived mechanism
  2038 that has been implemented on top of these primitives.  This concept
  2039 generalizes the existing ``theorem (in ...)'' towards more versatility
  2040 and scalability.
  2041 
  2042 * Proof General interface: proper undo of final 'end' command;
  2043 discontinued Isabelle/classic mode (ML proof scripts).
  2044 
  2045 
  2046 *** Document preparation ***
  2047 
  2048 * Added antiquotation @{theory name} which prints the given name,
  2049 after checking that it refers to a valid ancestor theory in the
  2050 current context.
  2051 
  2052 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2053 check the given source text as ML type/structure, printing verbatim.
  2054 
  2055 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2056 "c args == rhs" given in the current context.  (Any number of
  2057 arguments may be given on the LHS.)
  2058 
  2059 
  2060 *** Pure ***
  2061 
  2062 * The 'class' package offers a combination of axclass and locale to
  2063 achieve Haskell-like type classes in Isabelle.  Definitions and
  2064 theorems within a class context produce both relative results (with
  2065 implicit parameters according to the locale context), and polymorphic
  2066 constants with qualified polymorphism (according to the class
  2067 context).  Within the body context of a 'class' target, a separate
  2068 syntax layer ("user space type system") takes care of converting
  2069 between global polymorphic consts and internal locale representation.
  2070 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2071 "isatool doc classes" provides a tutorial.
  2072 
  2073 * Generic code generator framework allows to generate executable
  2074 code for ML and Haskell (including Isabelle classes).  A short usage
  2075 sketch:
  2076 
  2077     internal compilation:
  2078         export_code <list of constants (term syntax)> in SML
  2079     writing SML code to a file:
  2080         export_code <list of constants (term syntax)> in SML <filename>
  2081     writing OCaml code to a file:
  2082         export_code <list of constants (term syntax)> in OCaml <filename>
  2083     writing Haskell code to a bunch of files:
  2084         export_code <list of constants (term syntax)> in Haskell <filename>
  2085 
  2086     evaluating closed propositions to True/False using code generation:
  2087         method ``eval''
  2088 
  2089 Reasonable default setup of framework in HOL.
  2090 
  2091 Theorem attributs for selecting and transforming function equations theorems:
  2092 
  2093     [code fun]:        select a theorem as function equation for a specific constant
  2094     [code fun del]:    deselect a theorem as function equation for a specific constant
  2095     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2096     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2097 
  2098 User-defined serializations (target in {SML, OCaml, Haskell}):
  2099 
  2100     code_const <and-list of constants (term syntax)>
  2101       {(target) <and-list of const target syntax>}+
  2102 
  2103     code_type <and-list of type constructors>
  2104       {(target) <and-list of type target syntax>}+
  2105 
  2106     code_instance <and-list of instances>
  2107       {(target)}+
  2108         where instance ::= <type constructor> :: <class>
  2109 
  2110     code_class <and_list of classes>
  2111       {(target) <and-list of class target syntax>}+
  2112         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2113 
  2114 code_instance and code_class only are effective to target Haskell.
  2115 
  2116 For example usage see src/HOL/ex/Codegenerator.thy and
  2117 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2118 generation from Isabelle/HOL theories is available via "isatool doc
  2119 codegen".
  2120 
  2121 * Code generator: consts in 'consts_code' Isar commands are now
  2122 referred to by usual term syntax (including optional type
  2123 annotations).
  2124 
  2125 * Command 'no_translations' removes translation rules from theory
  2126 syntax.
  2127 
  2128 * Overloaded definitions are now actually checked for acyclic
  2129 dependencies.  The overloading scheme is slightly more general than
  2130 that of Haskell98, although Isabelle does not demand an exact
  2131 correspondence to type class and instance declarations.
  2132 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2133 exotic versions of overloading -- at the discretion of the user!
  2134 
  2135 Polymorphic constants are represented via type arguments, i.e. the
  2136 instantiation that matches an instance against the most general
  2137 declaration given in the signature.  For example, with the declaration
  2138 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2139 as c(nat).  Overloading is essentially simultaneous structural
  2140 recursion over such type arguments.  Incomplete specification patterns
  2141 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2142 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2143 Command 'print_theory' outputs the normalized system of recursive
  2144 equations, see section "definitions".
  2145 
  2146 * Configuration options are maintained within the theory or proof
  2147 context (with name and type bool/int/string), providing a very simple
  2148 interface to a poor-man's version of general context data.  Tools may
  2149 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2150 these values using Config.get etc.  Users may change options via an
  2151 associated attribute of the same name.  This form of context
  2152 declaration works particularly well with commands 'declare' or
  2153 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2154 very easy to avoid global references, which would not observe Isar
  2155 toplevel undo/redo and fail to work with multithreading.
  2156 
  2157 Various global ML references of Pure and HOL have been turned into
  2158 configuration options:
  2159 
  2160   Unify.search_bound		unify_search_bound
  2161   Unify.trace_bound		unify_trace_bound
  2162   Unify.trace_simp		unify_trace_simp
  2163   Unify.trace_types		unify_trace_types
  2164   Simplifier.simp_depth_limit	simp_depth_limit
  2165   Blast.depth_limit		blast_depth_limit
  2166   DatatypeProp.dtK		datatype_distinctness_limit
  2167   fast_arith_neq_limit  	fast_arith_neq_limit
  2168   fast_arith_split_limit	fast_arith_split_limit
  2169 
  2170 * Named collections of theorems may be easily installed as context
  2171 data using the functor NamedThmsFun (see also
  2172 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2173 attributes; there is also a toplevel print command.  This facility is
  2174 just a common case of general context data, which is the preferred way
  2175 for anything more complex than just a list of facts in canonical
  2176 order.
  2177 
  2178 * Isar: command 'declaration' augments a local theory by generic
  2179 declaration functions written in ML.  This enables arbitrary content
  2180 being added to the context, depending on a morphism that tells the
  2181 difference of the original declaration context wrt. the application
  2182 context encountered later on.
  2183 
  2184 * Isar: proper interfaces for simplification procedures.  Command
  2185 'simproc_setup' declares named simprocs (with match patterns, and body
  2186 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2187 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2188 
  2189 * Isar: an extra pair of brackets around attribute declarations
  2190 abbreviates a theorem reference involving an internal dummy fact,
  2191 which will be ignored later --- only the effect of the attribute on
  2192 the background context will persist.  This form of in-place
  2193 declarations is particularly useful with commands like 'declare' and
  2194 'using', for example ``have A using [[simproc a]] by simp''.
  2195 
  2196 * Isar: method "assumption" (and implicit closing of subproofs) now
  2197 takes simple non-atomic goal assumptions into account: after applying
  2198 an assumption as a rule the resulting subgoals are solved by atomic
  2199 assumption steps.  This is particularly useful to finish 'obtain'
  2200 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2201 without referring to the original premise "!!x. P x ==> thesis" in the
  2202 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2203 more permissive.
  2204 
  2205 * Isar: implicit use of prems from the Isar proof context is
  2206 considered a legacy feature.  Common applications like ``have A .''
  2207 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2208 referencing facts explicitly here improves readability and
  2209 maintainability of proof texts.
  2210 
  2211 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2212 the obtained context from the course of reasoning!  For example:
  2213 
  2214   assume "EX x y. A x & B y"   -- "any previous fact"
  2215   then guess x and y by clarify
  2216 
  2217 This technique is potentially adventurous, depending on the facts and
  2218 proof tools being involved here.
  2219 
  2220 * Isar: known facts from the proof context may be specified as literal
  2221 propositions, using ASCII back-quote syntax.  This works wherever
  2222 named facts used to be allowed so far, in proof commands, proof
  2223 methods, attributes etc.  Literal facts are retrieved from the context
  2224 according to unification of type and term parameters.  For example,
  2225 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2226 theorems in the current context, then these are valid literal facts:
  2227 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2228 
  2229 There is also a proof method "fact" which does the same composition
  2230 for explicit goal states, e.g. the following proof texts coincide with
  2231 certain special cases of literal facts:
  2232 
  2233   have "A" by fact                 ==  note `A`
  2234   have "A ==> B" by fact           ==  note `A ==> B`
  2235   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2236   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2237 
  2238 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2239 outer syntax.  Thus symbolic identifiers may be used without
  2240 additional white space in declarations like this: ``assume *: A''.
  2241 
  2242 * Isar: 'print_facts' prints all local facts of the current context,
  2243 both named and unnamed ones.
  2244 
  2245 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2246 
  2247   def x == "t" and y == "u"
  2248 
  2249 * Isar: added command 'unfolding', which is structurally similar to
  2250 'using', but affects both the goal state and facts by unfolding given
  2251 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2252 'unfolded' attribute may be replaced by first-class proof text.
  2253 
  2254 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2255 and command 'unfolding' now all support object-level equalities
  2256 (potentially conditional).  The underlying notion of rewrite rule is
  2257 analogous to the 'rule_format' attribute, but *not* that of the
  2258 Simplifier (which is usually more generous).
  2259 
  2260 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2261 premises of a theorem by n. Useful in conjunction with drule.
  2262 
  2263 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2264 method expression within a sandbox consisting of the first N
  2265 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2266 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2267 simplifies all new goals that emerge from applying rule foo to the
  2268 originally first one.
  2269 
  2270 * Isar: schematic goals are no longer restricted to higher-order
  2271 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2272 expected.
  2273 
  2274 * Isar: the conclusion of a long theorem statement is now either
  2275 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2276 (essentially a disjunction of cases with local parameters and
  2277 assumptions).  The latter allows to express general elimination rules
  2278 adequately; in this notation common elimination rules look like this:
  2279 
  2280   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2281     assumes "EX x. P x"
  2282     obtains x where "P x"
  2283 
  2284   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2285     assumes "A & B"
  2286     obtains A and B
  2287 
  2288   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2289     assumes "A | B"
  2290     obtains
  2291       A
  2292     | B
  2293 
  2294 The subsequent classical rules even refer to the formal "thesis"
  2295 explicitly:
  2296 
  2297   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2298     obtains "~ thesis"
  2299 
  2300   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2301     obtains "thesis ==> something"
  2302 
  2303 The actual proof of an 'obtains' statement is analogous to that of the
  2304 Isar proof element 'obtain', only that there may be several cases.
  2305 Optional case names may be specified in parentheses; these will be
  2306 available both in the present proof and as annotations in the
  2307 resulting rule, for later use with the 'cases' method (cf. attribute
  2308 case_names).
  2309 
  2310 * Isar: the assumptions of a long theorem statement are available as
  2311 "assms" fact in the proof context.  This is more appropriate than the
  2312 (historical) "prems", which refers to all assumptions of the current
  2313 context, including those from the target locale, proof body etc.
  2314 
  2315 * Isar: 'print_statement' prints theorems from the current theory or
  2316 proof context in long statement form, according to the syntax of a
  2317 top-level lemma.
  2318 
  2319 * Isar: 'obtain' takes an optional case name for the local context
  2320 introduction rule (default "that").
  2321 
  2322 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2323 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2324 to occur.
  2325 
  2326 * Pure: syntax "CONST name" produces a fully internalized constant
  2327 according to the current context.  This is particularly useful for
  2328 syntax translations that should refer to internal constant
  2329 representations independently of name spaces.
  2330 
  2331 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2332 instead of "FOO ". This allows multiple binder declarations to coexist
  2333 in the same context.  INCOMPATIBILITY.
  2334 
  2335 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2336 primitive that also works in a locale context (both for constants and
  2337 fixed variables). Type declaration and internal syntactic representation
  2338 of given constants retrieved from the context. Likewise, the
  2339 'no_notation' command allows to remove given syntax annotations from the
  2340 current context.
  2341 
  2342 * Isar/locales: new derived specification elements 'axiomatization',
  2343 'definition', 'abbreviation', which support type-inference, admit
  2344 object-level specifications (equality, equivalence).  See also the
  2345 isar-ref manual.  Examples:
  2346 
  2347   axiomatization
  2348     eq  (infix "===" 50) where
  2349     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2350 
  2351   definition "f x y = x + y + 1"
  2352   definition g where "g x = f x x"
  2353 
  2354   abbreviation
  2355     neq  (infix "=!=" 50) where
  2356     "x =!= y == ~ (x === y)"
  2357 
  2358 These specifications may be also used in a locale context.  Then the
  2359 constants being introduced depend on certain fixed parameters, and the
  2360 constant name is qualified by the locale base name.  An internal
  2361 abbreviation takes care for convenient input and output, making the
  2362 parameters implicit and using the original short name.  See also
  2363 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2364 entities from a monomorphic theory.
  2365 
  2366 Presently, abbreviations are only available 'in' a target locale, but
  2367 not inherited by general import expressions.  Also note that
  2368 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2369 'translations' in common applications.  The "no_abbrevs" print mode
  2370 prevents folding of abbreviations in term output.
  2371 
  2372 Concrete syntax is attached to specified constants in internal form,
  2373 independently of name spaces.  The parse tree representation is
  2374 slightly different -- use 'notation' instead of raw 'syntax', and
  2375 'translations' with explicit "CONST" markup to accommodate this.
  2376 
  2377 * Pure/Isar: unified syntax for new-style specification mechanisms
  2378 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2379 full type inference and dummy patterns ("_").  For example:
  2380 
  2381   definition "K x _ = x"
  2382 
  2383   inductive conj for A B
  2384   where "A ==> B ==> conj A B"
  2385 
  2386 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2387 the current context.  Print mode "no_abbrevs" prevents inversion of
  2388 abbreviations on output.
  2389 
  2390 * Isar/locales: improved parameter handling: use of locales "var" and
  2391 "struct" no longer necessary; - parameter renamings are no longer
  2392 required to be injective.  For example, this allows to define
  2393 endomorphisms as locale endom = homom mult mult h.
  2394 
  2395 * Isar/locales: changed the way locales with predicates are defined.
  2396 Instead of accumulating the specification, the imported expression is
  2397 now an interpretation.  INCOMPATIBILITY: different normal form of
  2398 locale expressions.  In particular, in interpretations of locales with
  2399 predicates, goals repesenting already interpreted fragments are not
  2400 removed automatically.  Use methods `intro_locales' and
  2401 `unfold_locales'; see below.
  2402 
  2403 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2404 provide backward reasoning on locales predicates.  The methods are
  2405 aware of interpretations and discharge corresponding goals.
  2406 `intro_locales' is less aggressive then `unfold_locales' and does not
  2407 unfold predicates to assumptions.
  2408 
  2409 * Isar/locales: the order in which locale fragments are accumulated
  2410 has changed.  This enables to override declarations from fragments due
  2411 to interpretations -- for example, unwanted simp rules.
  2412 
  2413 * Isar/locales: interpretation in theories and proof contexts has been
  2414 extended.  One may now specify (and prove) equations, which are
  2415 unfolded in interpreted theorems.  This is useful for replacing
  2416 defined concepts (constants depending on locale parameters) by
  2417 concepts already existing in the target context.  Example:
  2418 
  2419   interpretation partial_order ["op <= :: [int, int] => bool"]
  2420     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2421 
  2422 Typically, the constant `partial_order.less' is created by a
  2423 definition specification element in the context of locale
  2424 partial_order.
  2425 
  2426 * Method "induct": improved internal context management to support
  2427 local fixes and defines on-the-fly. Thus explicit meta-level
  2428 connectives !!  and ==> are rarely required anymore in inductive goals
  2429 (using object-logic connectives for this purpose has been long
  2430 obsolete anyway). Common proof patterns are explained in
  2431 src/HOL/Induct/Common_Patterns.thy, see also
  2432 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2433 examples.
  2434 
  2435 * Method "induct": improved handling of simultaneous goals. Instead of
  2436 introducing object-level conjunction, the statement is now split into
  2437 several conclusions, while the corresponding symbolic cases are nested
  2438 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2439 see src/HOL/Induct/Common_Patterns.thy, for example.
  2440 
  2441 * Method "induct": mutual induction rules are now specified as a list
  2442 of rule sharing the same induction cases. HOL packages usually provide
  2443 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2444 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2445 mutual induction rules differently, i.e. like this:
  2446 
  2447   (induct rule: foo_bar.inducts)
  2448   (induct set: foo bar)
  2449   (induct pred: foo bar)
  2450   (induct type: foo bar)
  2451 
  2452 The ML function ProjectRule.projections turns old-style rules into the
  2453 new format.
  2454 
  2455 * Method "coinduct": dual of induction, see
  2456 src/HOL/Library/Coinductive_List.thy for various examples.
  2457 
  2458 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2459 considered a legacy feature.
  2460 
  2461 * Attribute "symmetric" produces result with standardized schematic
  2462 variables (index 0).  Potential INCOMPATIBILITY.
  2463 
  2464 * Simplifier: by default the simplifier trace only shows top level
  2465 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2466 default. Thus there is less danger of being flooded by the trace. The
  2467 trace indicates where parts have been suppressed.
  2468   
  2469 * Provers/classical: removed obsolete classical version of elim_format
  2470 attribute; classical elim/dest rules are now treated uniformly when
  2471 manipulating the claset.
  2472 
  2473 * Provers/classical: stricter checks to ensure that supplied intro,
  2474 dest and elim rules are well-formed; dest and elim rules must have at
  2475 least one premise.
  2476 
  2477 * Provers/classical: attributes dest/elim/intro take an optional
  2478 weight argument for the rule (just as the Pure versions).  Weights are
  2479 ignored by automated tools, but determine the search order of single
  2480 rule steps.
  2481 
  2482 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2483 where the body does not mention the bound variable.  Note that dummy
  2484 patterns implicitly depend on their context of bounds, which makes
  2485 "{_. _}" match any set comprehension as expected.  Potential
  2486 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2487 constant "_idtdummy" in the binding position.
  2488 
  2489 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2490 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2491 for example "A -> B" => "Pi A (%_. B)".
  2492 
  2493 * Pure: 'class_deps' command visualizes the subclass relation, using
  2494 the graph browser tool.
  2495 
  2496 * Pure: 'print_theory' now suppresses certain internal declarations by
  2497 default; use '!' option for full details.
  2498 
  2499 
  2500 *** HOL ***
  2501 
  2502 * Method "metis" proves goals by applying the Metis general-purpose
  2503 resolution prover (see also http://gilith.com/software/metis/).
  2504 Examples are in the directory MetisExamples.  WARNING: the
  2505 Isabelle/HOL-Metis integration does not yet work properly with
  2506 multi-threading.
  2507   
  2508 * Command 'sledgehammer' invokes external automatic theorem provers as
  2509 background processes.  It generates calls to the "metis" method if
  2510 successful. These can be pasted into the proof.  Users do not have to
  2511 wait for the automatic provers to return.  WARNING: does not really
  2512 work with multi-threading.
  2513 
  2514 * New "auto_quickcheck" feature tests outermost goal statements for
  2515 potential counter-examples.  Controlled by ML references
  2516 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2517 5000 milliseconds).  Fails silently if statements is outside of
  2518 executable fragment, or any other codgenerator problem occurs.
  2519 
  2520 * New constant "undefined" with axiom "undefined x = undefined".
  2521 
  2522 * Added class "HOL.eq", allowing for code generation with polymorphic
  2523 equality.
  2524 
  2525 * Some renaming of class constants due to canonical name prefixing in
  2526 the new 'class' package:
  2527 
  2528     HOL.abs ~> HOL.abs_class.abs
  2529     HOL.divide ~> HOL.divide_class.divide
  2530     0 ~> HOL.zero_class.zero
  2531     1 ~> HOL.one_class.one
  2532     op + ~> HOL.plus_class.plus
  2533     op - ~> HOL.minus_class.minus
  2534     uminus ~> HOL.minus_class.uminus
  2535     op * ~> HOL.times_class.times
  2536     op < ~> HOL.ord_class.less
  2537     op <= > HOL.ord_class.less_eq
  2538     Nat.power ~> Power.power_class.power
  2539     Nat.size ~> Nat.size_class.size
  2540     Numeral.number_of ~> Numeral.number_class.number_of
  2541     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2542     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2543     Orderings.min ~> Orderings.ord_class.min
  2544     Orderings.max ~> Orderings.ord_class.max
  2545     Divides.op div ~> Divides.div_class.div
  2546     Divides.op mod ~> Divides.div_class.mod
  2547     Divides.op dvd ~> Divides.div_class.dvd
  2548 
  2549 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2550 
  2551 a) User-defined constants using any of the names "plus", "minus",
  2552 "times", "less" or "less_eq". The standard syntax translations for
  2553 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2554 names.
  2555 
  2556 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2557 INCOMPATIBILITY: use more specific names.
  2558 
  2559 c) Permutative equations (e.g. "a + b = b + a")
  2560 Since the change of names also changes the order of terms, permutative
  2561 rewrite rules may get applied in a different order. Experience shows
  2562 that this is rarely the case (only two adaptions in the whole Isabelle
  2563 distribution).  INCOMPATIBILITY: rewrite proofs
  2564 
  2565 d) ML code directly refering to constant names
  2566 This in general only affects hand-written proof tactics, simprocs and
  2567 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2568 Consider using @{const_name} antiquotation.
  2569 
  2570 * New class "default" with associated constant "default".
  2571 
  2572 * Function "sgn" is now overloaded and available on int, real, complex
  2573 (and other numeric types), using class "sgn".  Two possible defs of
  2574 sgn are given as equational assumptions in the classes sgn_if and
  2575 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2576 INCOMPATIBILITY.
  2577 
  2578 * Locale "partial_order" now unified with class "order" (cf. theory
  2579 Orderings), added parameter "less".  INCOMPATIBILITY.
  2580 
  2581 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2582 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2583 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2584 
  2585 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2586 changed order of proof goals in instance proofs.
  2587 
  2588 * The transitivity reasoner for partial and linear orders is set up
  2589 for classes "order" and "linorder".  Instances of the reasoner are available
  2590 in all contexts importing or interpreting the corresponding locales.
  2591 Method "order" invokes the reasoner separately; the reasoner
  2592 is also integrated with the Simplifier as a solver.  Diagnostic
  2593 command 'print_orders' shows the available instances of the reasoner
  2594 in the current context.
  2595 
  2596 * Localized monotonicity predicate in theory "Orderings"; integrated
  2597 lemmas max_of_mono and min_of_mono with this predicate.
  2598 INCOMPATIBILITY.
  2599 
  2600 * Formulation of theorem "dense" changed slightly due to integration
  2601 with new class dense_linear_order.
  2602 
  2603 * Uniform lattice theory development in HOL.
  2604 
  2605     constants "meet" and "join" now named "inf" and "sup"
  2606     constant "Meet" now named "Inf"
  2607 
  2608     classes "meet_semilorder" and "join_semilorder" now named
  2609       "lower_semilattice" and "upper_semilattice"
  2610     class "lorder" now named "lattice"
  2611     class "comp_lat" now named "complete_lattice"
  2612 
  2613     Instantiation of lattice classes allows explicit definitions
  2614     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2615 
  2616   INCOMPATIBILITY.  Theorem renames:
  2617 
  2618     meet_left_le            ~> inf_le1
  2619     meet_right_le           ~> inf_le2
  2620     join_left_le            ~> sup_ge1
  2621     join_right_le           ~> sup_ge2
  2622     meet_join_le            ~> inf_sup_ord
  2623     le_meetI                ~> le_infI
  2624     join_leI                ~> le_supI
  2625     le_meet                 ~> le_inf_iff
  2626     le_join                 ~> ge_sup_conv
  2627     meet_idempotent         ~> inf_idem
  2628     join_idempotent         ~> sup_idem
  2629     meet_comm               ~> inf_commute
  2630     join_comm               ~> sup_commute
  2631     meet_leI1               ~> le_infI1
  2632     meet_leI2               ~> le_infI2
  2633     le_joinI1               ~> le_supI1
  2634     le_joinI2               ~> le_supI2
  2635     meet_assoc              ~> inf_assoc
  2636     join_assoc              ~> sup_assoc
  2637     meet_left_comm          ~> inf_left_commute
  2638     meet_left_idempotent    ~> inf_left_idem
  2639     join_left_comm          ~> sup_left_commute
  2640     join_left_idempotent    ~> sup_left_idem
  2641     meet_aci                ~> inf_aci
  2642     join_aci                ~> sup_aci
  2643     le_def_meet             ~> le_iff_inf
  2644     le_def_join             ~> le_iff_sup
  2645     join_absorp2            ~> sup_absorb2
  2646     join_absorp1            ~> sup_absorb1
  2647     meet_absorp1            ~> inf_absorb1
  2648     meet_absorp2            ~> inf_absorb2
  2649     meet_join_absorp        ~> inf_sup_absorb
  2650     join_meet_absorp        ~> sup_inf_absorb
  2651     distrib_join_le         ~> distrib_sup_le
  2652     distrib_meet_le         ~> distrib_inf_le
  2653 
  2654     add_meet_distrib_left   ~> add_inf_distrib_left
  2655     add_join_distrib_left   ~> add_sup_distrib_left
  2656     is_join_neg_meet        ~> is_join_neg_inf
  2657     is_meet_neg_join        ~> is_meet_neg_sup
  2658     add_meet_distrib_right  ~> add_inf_distrib_right
  2659     add_join_distrib_right  ~> add_sup_distrib_right
  2660     add_meet_join_distribs  ~> add_sup_inf_distribs
  2661     join_eq_neg_meet        ~> sup_eq_neg_inf
  2662     meet_eq_neg_join        ~> inf_eq_neg_sup
  2663     add_eq_meet_join        ~> add_eq_inf_sup
  2664     meet_0_imp_0            ~> inf_0_imp_0
  2665     join_0_imp_0            ~> sup_0_imp_0
  2666     meet_0_eq_0             ~> inf_0_eq_0
  2667     join_0_eq_0             ~> sup_0_eq_0
  2668     neg_meet_eq_join        ~> neg_inf_eq_sup
  2669     neg_join_eq_meet        ~> neg_sup_eq_inf
  2670     join_eq_if              ~> sup_eq_if
  2671 
  2672     mono_meet               ~> mono_inf
  2673     mono_join               ~> mono_sup
  2674     meet_bool_eq            ~> inf_bool_eq
  2675     join_bool_eq            ~> sup_bool_eq
  2676     meet_fun_eq             ~> inf_fun_eq
  2677     join_fun_eq             ~> sup_fun_eq
  2678     meet_set_eq             ~> inf_set_eq
  2679     join_set_eq             ~> sup_set_eq
  2680     meet1_iff               ~> inf1_iff
  2681     meet2_iff               ~> inf2_iff
  2682     meet1I                  ~> inf1I
  2683     meet2I                  ~> inf2I
  2684     meet1D1                 ~> inf1D1
  2685     meet2D1                 ~> inf2D1
  2686     meet1D2                 ~> inf1D2
  2687     meet2D2                 ~> inf2D2
  2688     meet1E                  ~> inf1E
  2689     meet2E                  ~> inf2E
  2690     join1_iff               ~> sup1_iff
  2691     join2_iff               ~> sup2_iff
  2692     join1I1                 ~> sup1I1
  2693     join2I1                 ~> sup2I1
  2694     join1I1                 ~> sup1I1
  2695     join2I2                 ~> sup1I2
  2696     join1CI                 ~> sup1CI
  2697     join2CI                 ~> sup2CI
  2698     join1E                  ~> sup1E
  2699     join2E                  ~> sup2E
  2700 
  2701     is_meet_Meet            ~> is_meet_Inf
  2702     Meet_bool_def           ~> Inf_bool_def
  2703     Meet_fun_def            ~> Inf_fun_def
  2704     Meet_greatest           ~> Inf_greatest
  2705     Meet_lower              ~> Inf_lower
  2706     Meet_set_def            ~> Inf_set_def
  2707 
  2708     Sup_def                 ~> Sup_Inf
  2709     Sup_bool_eq             ~> Sup_bool_def
  2710     Sup_fun_eq              ~> Sup_fun_def
  2711     Sup_set_eq              ~> Sup_set_def
  2712 
  2713     listsp_meetI            ~> listsp_infI
  2714     listsp_meet_eq          ~> listsp_inf_eq
  2715 
  2716     meet_min                ~> inf_min
  2717     join_max                ~> sup_max
  2718 
  2719 * Added syntactic class "size"; overloaded constant "size" now has
  2720 type "'a::size ==> bool"
  2721 
  2722 * Internal reorganisation of `size' of datatypes: size theorems
  2723 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2724 simplification rules by default!); theorems "prod.size" now named
  2725 "*.size".
  2726 
  2727 * Class "div" now inherits from class "times" rather than "type".
  2728 INCOMPATIBILITY.
  2729 
  2730 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2731 Linorder etc.  have disappeared; operations defined in terms of
  2732 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2733 
  2734 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2735 
  2736 * HOL-Word: New extensive library and type for generic, fixed size
  2737 machine words, with arithemtic, bit-wise, shifting and rotating
  2738 operations, reflection into int, nat, and bool lists, automation for
  2739 linear arithmetic (by automatic reflection into nat or int), including
  2740 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2741 arithmetic type classes, supporting automatic simplification of
  2742 numerals on all operations.
  2743 
  2744 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2745 
  2746 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2747 
  2748 * Code generator library theories:
  2749   - Code_Integer represents HOL integers by big integer literals in target
  2750     languages.
  2751   - Code_Char represents HOL characters by character literals in target
  2752     languages.
  2753   - Code_Char_chr like Code_Char, but also offers treatment of character
  2754     codes; includes Code_Integer.
  2755   - Executable_Set allows to generate code for finite sets using lists.
  2756   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2757     denominator).
  2758   - Executable_Real implements a subset of real numbers, namly those
  2759     representable by rational numbers.
  2760   - Efficient_Nat implements natural numbers by integers, which in general will
  2761     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2762     includes Code_Integer.
  2763   - Code_Index provides an additional datatype index which is mapped to
  2764     target-language built-in integers.
  2765   - Code_Message provides an additional datatype message_string which is isomorphic to
  2766     strings; messages are mapped to target-language strings.
  2767 
  2768 * New package for inductive predicates
  2769 
  2770   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2771 
  2772     inductive
  2773       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2774       for z_1 :: U_1 and ... and z_n :: U_m
  2775     where
  2776       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2777     | ...
  2778 
  2779   with full support for type-inference, rather than
  2780 
  2781     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2782 
  2783     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2784     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2785 
  2786     inductive "s z_1 ... z_m"
  2787     intros
  2788       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2789       ...
  2790 
  2791   For backward compatibility, there is a wrapper allowing inductive
  2792   sets to be defined with the new package via
  2793 
  2794     inductive_set
  2795       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2796       for z_1 :: U_1 and ... and z_n :: U_m
  2797     where
  2798       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2799     | ...
  2800 
  2801   or
  2802 
  2803     inductive_set
  2804       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2805       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2806       for z_1 :: U_1 and ... and z_n :: U_m
  2807     where
  2808       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2809     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2810     | ...
  2811 
  2812   if the additional syntax "p ..." is required.
  2813 
  2814   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2815   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2816 
  2817   INCOMPATIBILITIES:
  2818 
  2819   - Since declaration and definition of inductive sets or predicates
  2820     is no longer separated, abbreviations involving the newly
  2821     introduced sets or predicates must be specified together with the
  2822     introduction rules after the 'where' keyword (see above), rather
  2823     than before the actual inductive definition.
  2824 
  2825   - The variables in induction and elimination rules are now
  2826     quantified in the order of their occurrence in the introduction
  2827     rules, rather than in alphabetical order. Since this may break
  2828     some proofs, these proofs either have to be repaired, e.g. by
  2829     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2830     statements of the form
  2831 
  2832       case (rule_i a_i_1 ... a_i_{k_i})
  2833 
  2834     or the old order of quantification has to be restored by explicitly adding
  2835     meta-level quantifiers in the introduction rules, i.e.
  2836 
  2837       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2838 
  2839   - The format of the elimination rules is now
  2840 
  2841       p z_1 ... z_m x_1 ... x_n ==>
  2842         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2843         ==> ... ==> P
  2844 
  2845     for predicates and
  2846 
  2847       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2848         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2849         ==> ... ==> P
  2850 
  2851     for sets rather than
  2852 
  2853       x : s z_1 ... z_m ==>
  2854         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2855         ==> ... ==> P
  2856 
  2857     This may require terms in goals to be expanded to n-tuples
  2858     (e.g. using case_tac or simplification with the split_paired_all
  2859     rule) before the above elimination rule is applicable.
  2860 
  2861   - The elimination or case analysis rules for (mutually) inductive
  2862     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2863     list of rules "p_1_..._p_k.elims" is no longer available.
  2864 
  2865 * New package "function"/"fun" for general recursive functions,
  2866 supporting mutual and nested recursion, definitions in local contexts,
  2867 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2868 for small examples, and the separate tutorial on the function
  2869 package. The old recdef "package" is still available as before, but
  2870 users are encouraged to use the new package.
  2871 
  2872 * Method "lexicographic_order" automatically synthesizes termination
  2873 relations as lexicographic combinations of size measures. 
  2874 
  2875 * Case-expressions allow arbitrary constructor-patterns (including
  2876 "_") and take their order into account, like in functional
  2877 programming.  Internally, this is translated into nested
  2878 case-expressions; missing cases are added and mapped to the predefined
  2879 constant "undefined". In complicated cases printing may no longer show
  2880 the original input but the internal form. Lambda-abstractions allow
  2881 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2882 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2883 variable.
  2884 
  2885 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2886 is an abbreviation for "of_nat :: nat => int". The simplification
  2887 rules for "of_nat" have been changed to work like "int" did
  2888 previously.  Potential INCOMPATIBILITY:
  2889   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2890   - of_nat_diff and of_nat_mult are no longer default simp rules
  2891 
  2892 * Method "algebra" solves polynomial equations over (semi)rings using
  2893 Groebner bases. The (semi)ring structure is defined by locales and the
  2894 tool setup depends on that generic context. Installing the method for
  2895 a specific type involves instantiating the locale and possibly adding
  2896 declarations for computation on the coefficients.  The method is
  2897 already instantiated for natural numbers and for the axiomatic class
  2898 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2899 CALCULEMUS 2007 for the general principles underlying this
  2900 architecture of context-aware proof-tools.
  2901 
  2902 * Method "ferrack" implements quantifier elimination over
  2903 special-purpose dense linear orders using locales (analogous to
  2904 "algebra"). The method is already installed for class
  2905 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2906 rat, etc.
  2907 
  2908 * Former constant "List.op @" now named "List.append".  Use ML
  2909 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2910 circumvent possible incompatibilities when working on ML level.
  2911 
  2912 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2913 
  2914 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2915 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2916 
  2917 * New syntax for Haskell-like list comprehension (input only), eg.
  2918 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2919 
  2920 * The special syntax for function "filter" has changed from [x :
  2921 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2922 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2923 
  2924 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2925 defined on nat only, as an abbreviation for [a..<Suc b]
  2926 INCOMPATIBILITY.
  2927 
  2928 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2929 
  2930 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2931 
  2932 * New lemma collection field_simps (an extension of ring_simps) for
  2933 manipulating (in)equations involving division. Multiplies with all
  2934 denominators that can be proved to be non-zero (in equations) or
  2935 positive/negative (in inequations).
  2936 
  2937 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2938 have been improved and renamed to ring_simps, group_simps and
  2939 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2940 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2941 
  2942 * Theory Library/Commutative_Ring: switched from recdef to function
  2943 package; constants add, mul, pow now curried.  Infix syntax for
  2944 algebraic operations.
  2945 
  2946 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2947 INCOMPATIBILITY.
  2948 
  2949 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2950 INCOMPATIBILITY.
  2951 
  2952 * HOL/records: generalised field-update to take a function on the
  2953 field rather than the new value: r(|A := x|) is translated to A_update
  2954 (K x) r The K-combinator that is internally used is called K_record.
  2955 INCOMPATIBILITY: Usage of the plain update functions has to be
  2956 adapted.
  2957  
  2958 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2959 * x = 0, which are required for a semiring.  Richer structures do not
  2960 inherit from semiring_0 anymore, because this property is a theorem
  2961 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2962 there is more to prove, but this is mostly trivial.
  2963 
  2964 * Class "recpower" is generalized to arbitrary monoids, not just
  2965 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2966 commutativity or semiring properties additionally.
  2967 
  2968 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2969 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2970 better use 'abbreviation'.
  2971 
  2972 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2973 
  2974 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2975 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2976 significant changes for setting up numeral syntax for types:
  2977   - New constants Numeral.pred and Numeral.succ instead
  2978       of former Numeral.bin_pred and Numeral.bin_succ.
  2979   - Use integer operations instead of bin_add, bin_mult and so on.
  2980   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2981   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2982 
  2983 See src/HOL/Integ/IntArith.thy for an example setup.
  2984 
  2985 * Command 'normal_form' computes the normal form of a term that may
  2986 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2987 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2988 heavy-duty computations because the functions are compiled to ML
  2989 first.  Correspondingly, a method "normalization" is provided.  See
  2990 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2991 
  2992 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2993 25 like -->); output depends on the "iff" print_mode, the default is
  2994 "A = B" (with priority 50).
  2995 
  2996 * Relations less (<) and less_eq (<=) are also available on type bool.
  2997 Modified syntax to disallow nesting without explicit parentheses,
  2998 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2999 INCOMPATIBILITY.
  3000 
  3001 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3002 
  3003 * Relation composition operator "op O" now has precedence 75 and binds
  3004 stronger than union and intersection. INCOMPATIBILITY.
  3005 
  3006 * The old set interval syntax "{m..n(}" (and relatives) has been
  3007 removed.  Use "{m..<n}" (and relatives) instead.
  3008 
  3009 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3010 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3011 ``declare [[simproc del: neq]]''.
  3012 
  3013 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3014 True/False.
  3015 
  3016 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3017 
  3018 * Theorem setsum_mult renamed to setsum_right_distrib.
  3019 
  3020 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3021 ``rule'' method.
  3022 
  3023 * Reimplemented methods "sat" and "satx", with several improvements:
  3024 goals no longer need to be stated as "<prems> ==> False", equivalences
  3025 (i.e. "=" on type bool) are handled, variable names of the form
  3026 "lit_<n>" are no longer reserved, significant speedup.
  3027 
  3028 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3029 zChaff is still supported as well.
  3030 
  3031 * 'inductive' and 'datatype': provide projections of mutual rules,
  3032 bundled as foo_bar.inducts;
  3033 
  3034 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3035 Library.
  3036 
  3037 * Library: moved theory Accessible_Part to main HOL.
  3038 
  3039 * Library: added theory Coinductive_List of potentially infinite lists
  3040 as greatest fixed-point.
  3041 
  3042 * Library: added theory AssocList which implements (finite) maps as
  3043 association lists.
  3044 
  3045 * Method "evaluation" solves goals (i.e. a boolean expression)
  3046 efficiently by compiling it to ML.  The goal is "proved" (via an
  3047 oracle) if it evaluates to True.
  3048 
  3049 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3050 also when invoked by the simplifier.  This results in the Simplifier
  3051 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3052 Configuration option fast_arith_split_limit=0 recovers the old
  3053 behavior.
  3054 
  3055 * Support for hex (0x20) and binary (0b1001) numerals.
  3056 
  3057 * New method: reify eqs (t), where eqs are equations for an
  3058 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3059 parameter, computes a term s::'b and a list xs::'a list and proves the
  3060 theorem I xs s = t. This is also known as reification or quoting. The
  3061 resulting theorem is applied to the subgoal to substitute t with I xs
  3062 s.  If t is omitted, the subgoal itself is reified.
  3063 
  3064 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3065 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3066 where f is supposed to be a computable function (in the sense of code
  3067 generattion). The method uses reify to compute s and xs as above then
  3068 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3069 r and finally gets the theorem t = r, which is again applied to the
  3070 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3071 
  3072 * Reflection: Automatic reification now handels binding, an example is
  3073 available in src/HOL/ex/ReflectionEx.thy
  3074 
  3075 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3076 command 'statespace' that is similar to 'record', but introduces an
  3077 abstract specification based on the locale infrastructure instead of
  3078 HOL types.  This leads to extra flexibility in composing state spaces,
  3079 in particular multiple inheritance and renaming of components.
  3080 
  3081 
  3082 *** HOL-Complex ***
  3083 
  3084 * Hyperreal: Functions root and sqrt are now defined on negative real
  3085 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3086 Nonnegativity side conditions have been removed from many lemmas, so
  3087 that more subgoals may now be solved by simplification; potential
  3088 INCOMPATIBILITY.
  3089 
  3090 * Real: new type classes formalize real normed vector spaces and
  3091 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3092 and norm :: 'a => real.
  3093 
  3094 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3095 reals into other types. The overloaded constant Reals :: 'a set is now
  3096 defined as range of_real; potential INCOMPATIBILITY.
  3097 
  3098 * Real: proper support for ML code generation, including 'quickcheck'.
  3099 Reals are implemented as arbitrary precision rationals.
  3100 
  3101 * Hyperreal: Several constants that previously worked only for the
  3102 reals have been generalized, so they now work over arbitrary vector
  3103 spaces. Type annotations may need to be added in some cases; potential
  3104 INCOMPATIBILITY.
  3105 
  3106   Infinitesimal  :: ('a::real_normed_vector) star set
  3107   HFinite        :: ('a::real_normed_vector) star set
  3108   HInfinite      :: ('a::real_normed_vector) star set
  3109   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3110   monad          :: ('a::real_normed_vector) star => 'a star set
  3111   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3112   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3113   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3114   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3115   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3116   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3117   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3118   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3119   sgn            :: 'a::real_normed_vector => 'a
  3120   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3121 
  3122 * Complex: Some complex-specific constants are now abbreviations for
  3123 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3124 hnorm.  Other constants have been entirely removed in favor of the
  3125 polymorphic versions (INCOMPATIBILITY):
  3126 
  3127   approx        <-- capprox
  3128   HFinite       <-- CFinite
  3129   HInfinite     <-- CInfinite
  3130   Infinitesimal <-- CInfinitesimal
  3131   monad         <-- cmonad
  3132   galaxy        <-- cgalaxy
  3133   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3134   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3135   (ns)deriv     <-- (ns)cderiv
  3136 
  3137 
  3138 *** HOL-Algebra ***
  3139 
  3140 * Formalisation of ideals and the quotient construction over rings.
  3141 
  3142 * Order and lattice theory no longer based on records.
  3143 INCOMPATIBILITY.
  3144 
  3145 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3146 greatest_closed.  INCOMPATIBILITY.
  3147 
  3148 * Method algebra is now set up via an attribute.  For examples see
  3149 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3150 of algebraic structures.
  3151 
  3152 * Renamed theory CRing to Ring.
  3153 
  3154 
  3155 *** HOL-Nominal ***
  3156 
  3157 * Substantial, yet incomplete support for nominal datatypes (binding
  3158 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3159 src/HOL/Nominal/Examples.  Prospective users should consult
  3160 http://isabelle.in.tum.de/nominal/
  3161 
  3162 
  3163 *** ML ***
  3164 
  3165 * ML basics: just one true type int, which coincides with IntInf.int
  3166 (even on SML/NJ).
  3167 
  3168 * ML within Isar: antiquotations allow to embed statically-checked
  3169 formal entities in the source, referring to the context available at
  3170 compile-time.  For example:
  3171 
  3172 ML {* @{sort "{zero,one}"} *}
  3173 ML {* @{typ "'a => 'b"} *}
  3174 ML {* @{term "%x. x"} *}
  3175 ML {* @{prop "x == y"} *}
  3176 ML {* @{ctyp "'a => 'b"} *}
  3177 ML {* @{cterm "%x. x"} *}
  3178 ML {* @{cprop "x == y"} *}
  3179 ML {* @{thm asm_rl} *}
  3180 ML {* @{thms asm_rl} *}
  3181 ML {* @{type_name c} *}
  3182 ML {* @{type_syntax c} *}
  3183 ML {* @{const_name c} *}
  3184 ML {* @{const_syntax c} *}
  3185 ML {* @{context} *}
  3186 ML {* @{theory} *}
  3187 ML {* @{theory Pure} *}
  3188 ML {* @{theory_ref} *}
  3189 ML {* @{theory_ref Pure} *}
  3190 ML {* @{simpset} *}
  3191 ML {* @{claset} *}
  3192 ML {* @{clasimpset} *}
  3193 
  3194 The same works for sources being ``used'' within an Isar context.
  3195 
  3196 * ML in Isar: improved error reporting; extra verbosity with
  3197 ML_Context.trace enabled.
  3198 
  3199 * Pure/General/table.ML: the join operations now works via exceptions
  3200 DUP/SAME instead of type option. This is simpler in simple cases, and
  3201 admits slightly more efficient complex applications.
  3202 
  3203 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3204 use Context.generic instead of just theory.
  3205 
  3206 * Pure: datatype Context.generic joins theory/Proof.context and
  3207 provides some facilities for code that works in either kind of
  3208 context, notably GenericDataFun for uniform theory and proof data.
  3209 
  3210 * Pure: simplified internal attribute type, which is now always
  3211 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3212 local (Proof.context) attributes have been discontinued, while
  3213 minimizing code duplication. Thm.rule_attribute and
  3214 Thm.declaration_attribute build canonical attributes; see also structure
  3215 Context for further operations on Context.generic, notably
  3216 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3217 declarations and definitions.
  3218 
  3219 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3220 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3221 init only required for impure data. INCOMPATIBILITY: empty really need
  3222 to be empty (no dependencies on theory content!)
  3223 
  3224 * Pure/kernel: consts certification ignores sort constraints given in
  3225 signature declarations. (This information is not relevant to the
  3226 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3227 potential INCOMPATIBILITY.
  3228 
  3229 * Pure: axiomatic type classes are now purely definitional, with
  3230 explicit proofs of class axioms and super class relations performed
  3231 internally. See Pure/axclass.ML for the main internal interfaces --
  3232 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3233 AxClass.axiomatize_class/classrel/arity supersede
  3234 Sign.add_classes/classrel/arities.
  3235 
  3236 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3237 global/local versions on theory vs. Proof.context have been
  3238 discontinued; Attrib.syntax and Method.syntax have been adapted
  3239 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3240 attributes, methods, etc.
  3241 
  3242 * Pure: several functions of signature "... -> theory -> theory * ..."
  3243 have been reoriented to "... -> theory -> ... * theory" in order to
  3244 allow natural usage in combination with the ||>, ||>>, |-> and
  3245 fold_map combinators.
  3246 
  3247 * Pure: official theorem names (closed derivations) and additional
  3248 comments (tags) are now strictly separate.  Name hints -- which are
  3249 maintained as tags -- may be attached any time without affecting the
  3250 derivation.
  3251 
  3252 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3253 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3254 achieve the old behaviour.
  3255 
  3256 * Pure: the "Goal" constant is now called "prop", supporting a
  3257 slightly more general idea of ``protecting'' meta-level rule
  3258 statements.
  3259 
  3260 * Pure: Logic.(un)varify only works in a global context, which is now
  3261 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3262 Logic.legacy_(un)varify as temporary workaround.
  3263 
  3264 * Pure: structure Name provides scalable operations for generating
  3265 internal variable names, notably Name.variants etc.  This replaces
  3266 some popular functions from term.ML:
  3267 
  3268   Term.variant		->  Name.variant
  3269   Term.variantlist	->  Name.variant_list
  3270   Term.invent_names	->  Name.invent_list
  3271 
  3272 Note that low-level renaming rarely occurs in new code -- operations
  3273 from structure Variable are used instead (see below).
  3274 
  3275 * Pure: structure Variable provides fundamental operations for proper
  3276 treatment of fixed/schematic variables in a context.  For example,
  3277 Variable.import introduces fixes for schematics of given facts and
  3278 Variable.export reverses the effect (up to renaming) -- this replaces
  3279 various freeze_thaw operations.
  3280 
  3281 * Pure: structure Goal provides simple interfaces for
  3282 init/conclude/finish and tactical prove operations (replacing former
  3283 Tactic.prove).  Goal.prove is the canonical way to prove results
  3284 within a given context; Goal.prove_global is a degraded version for
  3285 theory level goals, including a global Drule.standard.  Note that
  3286 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3287 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3288 in a locale context).
  3289 
  3290 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3291 and type checking (Syntax.check_term etc.), with common combinations
  3292 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3293 which are considered legacy and await removal.
  3294 
  3295 * Pure/Syntax: generic interfaces for type unchecking
  3296 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3297 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3298 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3299 available for convenience, but refer to the very same operations using
  3300 a mere theory instead of a full context.
  3301 
  3302 * Isar: simplified treatment of user-level errors, using exception
  3303 ERROR of string uniformly.  Function error now merely raises ERROR,
  3304 without any side effect on output channels.  The Isar toplevel takes
  3305 care of proper display of ERROR exceptions.  ML code may use plain
  3306 handle/can/try; cat_error may be used to concatenate errors like this:
  3307 
  3308   ... handle ERROR msg => cat_error msg "..."
  3309 
  3310 Toplevel ML code (run directly or through the Isar toplevel) may be
  3311 embedded into the Isar toplevel with exception display/debug like
  3312 this:
  3313 
  3314   Isar.toplevel (fn () => ...)
  3315 
  3316 INCOMPATIBILITY, removed special transform_error facilities, removed
  3317 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3318 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3319 -- use plain ERROR instead.
  3320 
  3321 * Isar: theory setup now has type (theory -> theory), instead of a
  3322 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3323 
  3324 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3325 ProofContext.debug/verbose flags.
  3326 
  3327 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3328 theory before entering a proof state.  Transactions now always see a
  3329 quasi-functional intermediate checkpoint, both in interactive and
  3330 batch mode.
  3331 
  3332 * Isar: simplified interfaces for outer syntax.  Renamed
  3333 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3334 OuterSyntax.add_parsers -- this functionality is now included in
  3335 OuterSyntax.command etc.  INCOMPATIBILITY.
  3336 
  3337 * Simplifier: the simpset of a running simplification process now
  3338 contains a proof context (cf. Simplifier.the_context), which is the
  3339 very context that the initial simpset has been retrieved from (by
  3340 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3341 (solver, looper etc.) may depend on arbitrary proof data.
  3342 
  3343 * Simplifier.inherit_context inherits the proof context (plus the
  3344 local bounds) of the current simplification process; any simproc
  3345 etc. that calls the Simplifier recursively should do this!  Removed
  3346 former Simplifier.inherit_bounds, which is already included here --
  3347 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3348 specify an explicit context using Simplifier.context/theory_context.
  3349 
  3350 * Simplifier/Classical Reasoner: more abstract interfaces
  3351 change_simpset/claset for modifying the simpset/claset reference of a
  3352 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3353 INCOMPATIBILITY.
  3354 
  3355 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3356 "Trueprop" etc.
  3357 
  3358 
  3359 *** System ***
  3360 
  3361 * settings: the default heap location within ISABELLE_HOME_USER now
  3362 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3363 Isabelle installations.
  3364 
  3365 * isabelle-process: option -S (secure mode) disables some critical
  3366 operations, notably runtime compilation and evaluation of ML source
  3367 code.
  3368 
  3369 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3370 
  3371 * Support for parallel execution, using native multicore support of
  3372 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3373 independent theories, according to the given theory header
  3374 specifications. The maximum number of worker threads is specified via
  3375 usedir option -M or the "max-threads" setting in Proof General. A
  3376 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3377 to 6 on a 8-core machine.  User-code needs to observe certain
  3378 guidelines for thread-safe programming, see appendix A in the Isar
  3379 Implementation manual.
  3380 
  3381 
  3382 
  3383 New in Isabelle2005 (October 2005)
  3384 ----------------------------------
  3385 
  3386 *** General ***
  3387 
  3388 * Theory headers: the new header syntax for Isar theories is
  3389 
  3390   theory <name>
  3391   imports <theory1> ... <theoryN>
  3392   uses <file1> ... <fileM>
  3393   begin
  3394 
  3395 where the 'uses' part is optional.  The previous syntax
  3396 
  3397   theory <name> = <theory1> + ... + <theoryN>:
  3398 
  3399 will disappear in the next release.  Use isatool fixheaders to convert
  3400 existing theory files.  Note that there is no change in ancient
  3401 non-Isar theories now, but these will disappear soon.
  3402 
  3403 * Theory loader: parent theories can now also be referred to via
  3404 relative and absolute paths.
  3405 
  3406 * Command 'find_theorems' searches for a list of criteria instead of a
  3407 list of constants. Known criteria are: intro, elim, dest, name:string,
  3408 simp:term, and any term. Criteria can be preceded by '-' to select
  3409 theorems that do not match. Intro, elim, dest select theorems that
  3410 match the current goal, name:s selects theorems whose fully qualified
  3411 name contain s, and simp:term selects all simplification rules whose
  3412 lhs match term.  Any other term is interpreted as pattern and selects
  3413 all theorems matching the pattern. Available in ProofGeneral under
  3414 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3415 
  3416   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3417 
  3418 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3419 matching the current goal as introduction rule and not having "HOL."
  3420 in their name (i.e. not being defined in theory HOL).
  3421 
  3422 * Command 'thms_containing' has been discontinued in favour of
  3423 'find_theorems'; INCOMPATIBILITY.
  3424 
  3425 * Communication with Proof General is now 8bit clean, which means that
  3426 Unicode text in UTF-8 encoding may be used within theory texts (both
  3427 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3428 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3429 
  3430   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3431   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3432 
  3433 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3434 Classical Reasoner.  Typical big applications run around 2 times
  3435 faster.
  3436 
  3437 
  3438 *** Document preparation ***
  3439 
  3440 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3441 of raw sources.  Only those symbols that do not require additional
  3442 LaTeX packages (depending on comments in isabellesym.sty) are
  3443 displayed properly, everything else is left verbatim.  isatool display
  3444 and isatool print are used as front ends (these are subject to the
  3445 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3446 
  3447 * Command tags control specific markup of certain regions of text,
  3448 notably folding and hiding.  Predefined tags include "theory" (for
  3449 theory begin and end), "proof" for proof commands, and "ML" for
  3450 commands involving ML code; the additional tags "visible" and
  3451 "invisible" are unused by default.  Users may give explicit tag
  3452 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3453 interpretation of tags is determined by the LaTeX job during document
  3454 preparation: see option -V of isatool usedir, or options -n and -t of
  3455 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3456 \isadroptag.
  3457 
  3458 Several document versions may be produced at the same time via isatool
  3459 usedir (the generated index.html will link all of them).  Typical
  3460 specifications include ''-V document=theory,proof,ML'' to present
  3461 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3462 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3463 these parts without any formal replacement text.  The Isabelle site
  3464 default settings produce ''document'' and ''outline'' versions as
  3465 specified above.
  3466 
  3467 * Several new antiquotations:
  3468 
  3469   @{term_type term} prints a term with its type annotated;
  3470 
  3471   @{typeof term} prints the type of a term;
  3472 
  3473   @{const const} is the same as @{term const}, but checks that the
  3474   argument is a known logical constant;
  3475 
  3476   @{term_style style term} and @{thm_style style thm} print a term or
  3477   theorem applying a "style" to it
  3478 
  3479   @{ML text}
  3480 
  3481 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3482 definitions, equations, inequations etc., 'concl' printing only the
  3483 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3484 to print the specified premise.  TermStyle.add_style provides an ML
  3485 interface for introducing further styles.  See also the "LaTeX Sugar"
  3486 document practical applications.  The ML antiquotation prints
  3487 type-checked ML expressions verbatim.
  3488 
  3489 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3490 and 'text' support optional locale specification '(in loc)', which
  3491 specifies the default context for interpreting antiquotations.  For
  3492 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3493 
  3494 * Option 'locale=NAME' of antiquotations specifies an alternative
  3495 context interpreting the subsequent argument.  For example: @{thm
  3496 [locale=lattice] inf_assoc}.
  3497 
  3498 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3499 a proof context.
  3500 
  3501 * Proper output of antiquotations for theory commands involving a
  3502 proof context (such as 'locale' or 'theorem (in loc) ...').
  3503 
  3504 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3505 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3506 
  3507 * isatool usedir: new option -C (default true) controls whether option
  3508 -D should include a copy of the original document directory; -C false
  3509 prevents unwanted effects such as copying of administrative CVS data.
  3510 
  3511 
  3512 *** Pure ***
  3513 
  3514 * Considerably improved version of 'constdefs' command.  Now performs
  3515 automatic type-inference of declared constants; additional support for
  3516 local structure declarations (cf. locales and HOL records), see also
  3517 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3518 sequential dependencies of definitions within a single 'constdefs'
  3519 section; moreover, the declared name needs to be an identifier.  If
  3520 all fails, consider to fall back on 'consts' and 'defs' separately.
  3521 
  3522 * Improved indexed syntax and implicit structures.  First of all,
  3523 indexed syntax provides a notational device for subscripted
  3524 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3525 expressions.  Secondly, in a local context with structure
  3526 declarations, number indexes \<^sub>n or the empty index (default
  3527 number 1) refer to a certain fixed variable implicitly; option
  3528 show_structs controls printing of implicit structures.  Typical
  3529 applications of these concepts involve record types and locales.
  3530 
  3531 * New command 'no_syntax' removes grammar declarations (and
  3532 translations) resulting from the given syntax specification, which is
  3533 interpreted in the same manner as for the 'syntax' command.
  3534 
  3535 * 'Advanced' translation functions (parse_translation etc.) may depend
  3536 on the signature of the theory context being presently used for
  3537 parsing/printing, see also isar-ref manual.
  3538 
  3539 * Improved 'oracle' command provides a type-safe interface to turn an
  3540 ML expression of type theory -> T -> term into a primitive rule of
  3541 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3542 is already included here); see also FOL/ex/IffExample.thy;
  3543 INCOMPATIBILITY.
  3544 
  3545 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3546 before); "cI" is no longer bound, use "c.intro" instead.
  3547 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3548 axclasses vs. locales.
  3549 
  3550 * Improved internal renaming of symbolic identifiers -- attach primes
  3551 instead of base 26 numbers.
  3552 
  3553 * New flag show_question_marks controls printing of leading question
  3554 marks in schematic variable names.
  3555 
  3556 * In schematic variable names, *any* symbol following \<^isub> or
  3557 \<^isup> is now treated as part of the base name.  For example, the
  3558 following works without printing of awkward ".0" indexes:
  3559 
  3560   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3561     by simp
  3562 
  3563 * Inner syntax includes (*(*nested*) comments*).
  3564 
  3565 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3566 annotations as "(00...)".
  3567 
  3568 * Clear separation of logical types and nonterminals, where the latter
  3569 may only occur in 'syntax' specifications or type abbreviations.
  3570 Before that distinction was only partially implemented via type class
  3571 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3572 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3573 exotic syntax specifications may require further adaption
  3574 (e.g. Cube/Cube.thy).
  3575 
  3576 * Removed obsolete type class "logic", use the top sort {} instead.
  3577 Note that non-logical types should be declared as 'nonterminals'
  3578 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3579 specifications.
  3580 
  3581 * Attributes 'induct' and 'cases': type or set names may now be
  3582 locally fixed variables as well.
  3583 
  3584 * Simplifier: can now control the depth to which conditional rewriting
  3585 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3586 Limit.
  3587 
  3588 * Simplifier: simplification procedures may now take the current
  3589 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3590 interface), which is very useful for calling the Simplifier
  3591 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3592 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3593 low-level mk_simproc no longer applies Logic.varify internally, to
  3594 allow for use in a context of fixed variables.
  3595 
  3596 * thin_tac now works even if the assumption being deleted contains !!
  3597 or ==>.  More generally, erule now works even if the major premise of
  3598 the elimination rule contains !! or ==>.
  3599 
  3600 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3601 
  3602 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3603 from Pure, which contains all common declarations already.  Both
  3604 theories are defined via plain Isabelle/Isar .thy files.
  3605 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3606 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3607 use isatool fixcpure to adapt your theory and ML sources.
  3608 
  3609 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3610 selections of theorems in named facts via index ranges.
  3611 
  3612 * 'print_theorems': in theory mode, really print the difference
  3613 wrt. the last state (works for interactive theory development only),
  3614 in proof mode print all local facts (cf. 'print_facts');
  3615 
  3616 * 'hide': option '(open)' hides only base names.
  3617 
  3618 * More efficient treatment of intermediate checkpoints in interactive
  3619 theory development.
  3620 
  3621 * Code generator is now invoked via code_module (incremental code
  3622 generation) and code_library (modular code generation, ML structures
  3623 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3624 must be quoted when used as identifiers.
  3625 
  3626 * New 'value' command for reading, evaluating and printing terms using
  3627 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3628 quoted when used as identifier.
  3629 
  3630 
  3631 *** Locales ***
  3632 
  3633 * New commands for the interpretation of locale expressions in
  3634 theories (1), locales (2) and proof contexts (3).  These generate
  3635 proof obligations from the expression specification.  After the
  3636 obligations have been discharged, theorems of the expression are added
  3637 to the theory, target locale or proof context.  The synopsis of the
  3638 commands is a follows:
  3639 
  3640   (1) interpretation expr inst
  3641   (2) interpretation target < expr
  3642   (3) interpret expr inst
  3643 
  3644 Interpretation in theories and proof contexts require a parameter
  3645 instantiation of terms from the current context.  This is applied to
  3646 specifications and theorems of the interpreted expression.
  3647 Interpretation in locales only permits parameter renaming through the
  3648 locale expression.  Interpretation is smart in that interpretations
  3649 that are active already do not occur in proof obligations, neither are
  3650 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3651 inspect active interpretations of a particular locale.  For details,
  3652 see the Isar Reference manual.  Examples can be found in
  3653 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3654 
  3655 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3656 'interpret' instead.
  3657 
  3658 * New context element 'constrains' for adding type constraints to
  3659 parameters.
  3660 
  3661 * Context expressions: renaming of parameters with syntax
  3662 redeclaration.
  3663 
  3664 * Locale declaration: 'includes' disallowed.
  3665 
  3666 * Proper static binding of attribute syntax -- i.e. types / terms /
  3667 facts mentioned as arguments are always those of the locale definition
  3668 context, independently of the context of later invocations.  Moreover,
  3669 locale operations (renaming and type / term instantiation) are applied
  3670 to attribute arguments as expected.
  3671 
  3672 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3673 actual attributes; rare situations may require Attrib.attribute to
  3674 embed those attributes into Attrib.src that lack concrete syntax.
  3675 Attribute implementations need to cooperate properly with the static
  3676 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3677 Attrib.XXX_thm etc. already do the right thing without further
  3678 intervention.  Only unusual applications -- such as "where" or "of"
  3679 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3680 on the context and the facts involved -- may have to assign parsed
  3681 values to argument tokens explicitly.
  3682 
  3683 * Changed parameter management in theorem generation for long goal
  3684 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3685 theorem statement in rare situations.
  3686 
  3687 * Locale inspection command 'print_locale' omits notes elements.  Use
  3688 'print_locale!' to have them included in the output.
  3689 
  3690 
  3691 *** Provers ***
  3692 
  3693 * Provers/hypsubst.ML: improved version of the subst method, for
  3694 single-step rewriting: it now works in bound variable contexts. New is
  3695 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3696 rewrite a different subterm than the original subst method, which is
  3697 still available as 'simplesubst'.
  3698 
  3699 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3700 and quasi orders.
  3701 
  3702 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3703 reflexive-transitive closure of relations.
  3704 
  3705 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3706 limit (previously hard-coded with a value of 20) user-definable.
  3707 
  3708 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3709 is peformed already.  Object-logics merely need to finish their
  3710 initial simpset configuration as before.  INCOMPATIBILITY.
  3711 
  3712 
  3713 *** HOL ***
  3714 
  3715 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3716 
  3717   syntax (epsilon)
  3718     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3719 
  3720 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3721 and x-symbol; use option '-m epsilon' to get it actually printed.
  3722 Moreover, the mathematically important symbolic identifier \<epsilon>
  3723 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3724 
  3725 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3726 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3727 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3728 support corresponding Isar calculations.
  3729 
  3730 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3731 instead of ":".
  3732 
  3733 * theory SetInterval: changed the syntax for open intervals:
  3734 
  3735   Old       New
  3736   {..n(}    {..<n}
  3737   {)n..}    {n<..}
  3738   {m..n(}   {m..<n}
  3739   {)m..n}   {m<..n}
  3740   {)m..n(}  {m<..<n}
  3741 
  3742 The old syntax is still supported but will disappear in the next
  3743 release.  For conversion use the following Emacs search and replace
  3744 patterns (these are not perfect but work quite well):
  3745 
  3746   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3747   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3748 
  3749 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3750 equalities in commutative rings; method 'algebra' provides a generic
  3751 interface.
  3752 
  3753 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3754 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3755 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3756 be a tuple pattern.
  3757 
  3758 Some new syntax forms are available:
  3759 
  3760   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3761   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3762   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3763   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3764 
  3765 The latter form "\<Sum>x < k. e" used to be based on a separate
  3766 function "Summation", which has been discontinued.
  3767 
  3768 * theory Finite_Set: in structured induction proofs, the insert case
  3769 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3770 (insert F x)'.
  3771 
  3772 * The 'refute' command has been extended to support a much larger
  3773 fragment of HOL, including axiomatic type classes, constdefs and
  3774 typedefs, inductive datatypes and recursion.
  3775 
  3776 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3777 Requires zChaff with proof generation to be installed.  See
  3778 HOL/ex/SAT_Examples.thy for examples.
  3779 
  3780 * Datatype induction via method 'induct' now preserves the name of the
  3781 induction variable. For example, when proving P(xs::'a list) by
  3782 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3783 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3784 in unstructured proof scripts.
  3785 
  3786 * Reworked implementation of records.  Improved scalability for
  3787 records with many fields, avoiding performance problems for type
  3788 inference. Records are no longer composed of nested field types, but
  3789 of nested extension types. Therefore the record type only grows linear
  3790 in the number of extensions and not in the number of fields.  The
  3791 top-level (users) view on records is preserved.  Potential
  3792 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3793 old record representation. The type generated for a record is called
  3794 <record_name>_ext_type.
  3795 
  3796 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3797 proofs triggered by a record definition or a simproc (if
  3798 quick_and_dirty is enabled).  Definitions of large records can take
  3799 quite long.
  3800 
  3801 New simproc record_upd_simproc for simplification of multiple record
  3802 updates enabled by default.  Moreover, trivial updates are also
  3803 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3804 occasionally, since simplification is more powerful by default.
  3805 
  3806 * typedef: proper support for polymorphic sets, which contain extra
  3807 type-variables in the term.
  3808 
  3809 * Simplifier: automatically reasons about transitivity chains
  3810 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3811 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3812 old proofs break occasionally as simplification may now solve more
  3813 goals than previously.
  3814 
  3815 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3816 present.  Works for all partial orders (class "order"), in particular
  3817 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3818 just like y <= x.
  3819 
  3820 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3821 bound variable or a constant then the let is unfolded.  Otherwise
  3822 first a is simplified to b, and then f b is simplified to g. If
  3823 possible we abstract b from g arriving at "let x = b in h x",
  3824 otherwise we unfold the let and arrive at g.  The simproc can be
  3825 enabled/disabled by the reference use_let_simproc.  Potential
  3826 INCOMPATIBILITY since simplification is more powerful by default.
  3827 
  3828 * Classical reasoning: the meson method now accepts theorems as arguments.
  3829 
  3830 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3831 jobs to provide advice on the provability of subgoals.
  3832 
  3833 * Theory OrderedGroup and Ring_and_Field: various additions and
  3834 improvements to faciliate calculations involving equalities and
  3835 inequalities.
  3836 
  3837 The following theorems have been eliminated or modified
  3838 (INCOMPATIBILITY):
  3839 
  3840   abs_eq             now named abs_of_nonneg
  3841   abs_of_ge_0        now named abs_of_nonneg
  3842   abs_minus_eq       now named abs_of_nonpos
  3843   imp_abs_id         now named abs_of_nonneg
  3844   imp_abs_neg_id     now named abs_of_nonpos
  3845   mult_pos           now named mult_pos_pos
  3846   mult_pos_le        now named mult_nonneg_nonneg
  3847   mult_pos_neg_le    now named mult_nonneg_nonpos
  3848   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3849   mult_neg           now named mult_neg_neg
  3850   mult_neg_le        now named mult_nonpos_nonpos
  3851 
  3852 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3853      
  3854      zero_le_square
  3855      not_square_less_zero 
  3856 
  3857   The following lemmas have been deleted from Real/RealPow:
  3858   
  3859      realpow_zero_zero
  3860      realpow_two
  3861      realpow_less
  3862      zero_le_power
  3863      realpow_two_le
  3864      abs_realpow_two
  3865      realpow_two_abs     
  3866 
  3867 * Theory Parity: added rules for simplifying exponents.
  3868 
  3869 * Theory List:
  3870 
  3871 The following theorems have been eliminated or modified
  3872 (INCOMPATIBILITY):
  3873 
  3874   list_all_Nil       now named list_all.simps(1)
  3875   list_all_Cons      now named list_all.simps(2)
  3876   list_all_conv      now named list_all_iff
  3877   set_mem_eq         now named mem_iff
  3878 
  3879 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3880 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3881 
  3882 
  3883 *** HOL-Complex ***
  3884 
  3885 * Theory RealDef: better support for embedding natural numbers and
  3886 integers in the reals.
  3887 
  3888 The following theorems have been eliminated or modified
  3889 (INCOMPATIBILITY):
  3890 
  3891   exp_ge_add_one_self  now requires no hypotheses
  3892   real_of_int_add      reversed direction of equality (use [symmetric])
  3893   real_of_int_minus    reversed direction of equality (use [symmetric])
  3894   real_of_int_diff     reversed direction of equality (use [symmetric])
  3895   real_of_int_mult     reversed direction of equality (use [symmetric])
  3896 
  3897 * Theory RComplete: expanded support for floor and ceiling functions.
  3898 
  3899 * Theory Ln is new, with properties of the natural logarithm
  3900 
  3901 * Hyperreal: There is a new type constructor "star" for making
  3902 nonstandard types.  The old type names are now type synonyms:
  3903 
  3904   hypreal = real star
  3905   hypnat = nat star
  3906   hcomplex = complex star
  3907 
  3908 * Hyperreal: Many groups of similarly-defined constants have been
  3909 replaced by polymorphic versions (INCOMPATIBILITY):
  3910 
  3911   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3912 
  3913   starset      <-- starsetNat, starsetC
  3914   *s*          <-- *sNat*, *sc*
  3915   starset_n    <-- starsetNat_n, starsetC_n
  3916   *sn*         <-- *sNatn*, *scn*
  3917   InternalSets <-- InternalNatSets, InternalCSets
  3918 
  3919   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3920   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3921   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3922   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3923   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3924 
  3925 * Hyperreal: Many type-specific theorems have been removed in favor of
  3926 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3927 
  3928   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3929   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3930   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3931   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3932   right_minus <-- hypreal_add_minus
  3933   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3934   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3935   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3936   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3937   mult_1_right <-- hcomplex_mult_one_right
  3938   mult_zero_left <-- hcomplex_mult_zero_left
  3939   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3940   right_distrib <-- hypnat_add_mult_distrib2
  3941   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3942   right_inverse <-- hypreal_mult_inverse
  3943   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3944   order_refl <-- {hypreal,hypnat}_le_refl
  3945   order_trans <-- {hypreal,hypnat}_le_trans
  3946   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3947   order_less_le <-- {hypreal,hypnat}_less_le
  3948   linorder_linear <-- {hypreal,hypnat}_le_linear
  3949   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3950   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3951   add_nonneg_nonneg <-- hypreal_le_add_order
  3952 
  3953 * Hyperreal: Separate theorems having to do with type-specific
  3954 versions of constants have been merged into theorems that apply to the
  3955 new polymorphic constants (INCOMPATIBILITY):
  3956 
  3957   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3958   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3959   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3960   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3961   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3962   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3963   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3964   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3965   STAR_diff <-- {STAR,STARC}_diff
  3966   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3967     STARC_hcomplex_of_complex}_image_subset
  3968   starset_n_Un <-- starset{Nat,C}_n_Un
  3969   starset_n_Int <-- starset{Nat,C}_n_Int
  3970   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3971   starset_n_diff <-- starset{Nat,C}_n_diff
  3972   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3973   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3974   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3975   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3976   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3977   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3978   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3979   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3980   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3981   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3982   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3983   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3984   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3985   starfun_diff <-- starfun{C,RC,CR}_diff
  3986   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3987   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3988   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3989   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3990   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3991   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3992   starfun_Id <-- starfunC_Id
  3993   starfun_approx <-- starfun{Nat,CR}_approx
  3994   starfun_capprox <-- starfun{C,RC}_capprox
  3995   starfun_abs <-- starfunNat_rabs
  3996   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3997   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3998   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3999   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4000   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4001   starfun_add_approx <-- starfunCR_add_approx
  4002   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4003   starfun_divide <-- starfun{C,CR,RC}_divide
  4004   starfun_n <-- starfun{Nat,C}_n
  4005   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4006   starfun_n_add <-- starfun{Nat,C}_n_add
  4007   starfun_n_add_minus <-- starfunNat_n_add_minus
  4008   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4009   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4010   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4011 
  4012   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4013   star_n_minus <-- {hypreal,hcomplex}_minus
  4014   star_n_diff <-- {hypreal,hcomplex}_diff
  4015   star_n_mult <-- {hypreal,hcomplex}_mult
  4016   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4017   star_n_le <-- {hypreal,hypnat}_le
  4018   star_n_less <-- {hypreal,hypnat}_less
  4019   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4020   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4021   star_n_abs <-- hypreal_hrabs
  4022   star_n_divide <-- hcomplex_divide
  4023 
  4024   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4025   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4026   star_of_diff <-- hypreal_of_real_diff
  4027   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4028   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4029   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4030   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4031   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4032   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4033   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4034   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4035   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4036   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4037   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4038   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4039   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4040   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4041   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4042   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4043   star_of_power <-- hypreal_of_real_power
  4044   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4045 
  4046 * Hyperreal: new method "transfer" that implements the transfer
  4047 principle of nonstandard analysis. With a subgoal that mentions
  4048 nonstandard types like "'a star", the command "apply transfer"
  4049 replaces it with an equivalent one that mentions only standard types.
  4050 To be successful, all free variables must have standard types; non-
  4051 standard variables must have explicit universal quantifiers.
  4052 
  4053 * Hyperreal: A theory of Taylor series.
  4054 
  4055 
  4056 *** HOLCF ***
  4057 
  4058 * Discontinued special version of 'constdefs' (which used to support
  4059 continuous functions) in favor of the general Pure one with full
  4060 type-inference.
  4061 
  4062 * New simplification procedure for solving continuity conditions; it
  4063 is much faster on terms with many nested lambda abstractions (cubic
  4064 instead of exponential time).
  4065 
  4066 * New syntax for domain package: selector names are now optional.
  4067 Parentheses should be omitted unless argument is lazy, for example:
  4068 
  4069   domain 'a stream = cons "'a" (lazy "'a stream")
  4070 
  4071 * New command 'fixrec' for defining recursive functions with pattern
  4072 matching; defining multiple functions with mutual recursion is also
  4073 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4074 sinr, or any data constructor defined by the domain package. The given
  4075 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4076 syntax and examples.
  4077 
  4078 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4079 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4080 but the proof obligation additionally includes an admissibility
  4081 requirement. The packages generate instances of class cpo or pcpo,
  4082 with continuity and strictness theorems for Rep and Abs.
  4083 
  4084 * HOLCF: Many theorems have been renamed according to a more standard naming
  4085 scheme (INCOMPATIBILITY):
  4086 
  4087   foo_inject:  "foo$x = foo$y ==> x = y"
  4088   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4089   foo_less:    "(foo$x << foo$y) = (x << y)"
  4090   foo_strict:  "foo$UU = UU"
  4091   foo_defined: "... ==> foo$x ~= UU"
  4092   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4093 
  4094 
  4095 *** ZF ***
  4096 
  4097 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4098 including the First Isomorphism Theorem (on quotienting by the kernel
  4099 of a homomorphism).
  4100 
  4101 * ZF/Simplifier: install second copy of type solver that actually
  4102 makes use of TC rules declared to Isar proof contexts (or locales);
  4103 the old version is still required for ML proof scripts.
  4104 
  4105 
  4106 *** Cube ***
  4107 
  4108 * Converted to Isar theory format; use locales instead of axiomatic
  4109 theories.
  4110 
  4111 
  4112 *** ML ***
  4113 
  4114 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4115 for ||>, ||>>, |>>,
  4116 
  4117 * Pure/library.ML no longer defines its own option datatype, but uses
  4118 that of the SML basis, which has constructors NONE and SOME instead of
  4119 None and Some, as well as exception Option.Option instead of OPTION.
  4120 The functions the, if_none, is_some, is_none have been adapted
  4121 accordingly, while Option.map replaces apsome.
  4122 
  4123 * Pure/library.ML: the exception LIST has been given up in favour of
  4124 the standard exceptions Empty and Subscript, as well as
  4125 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4126 superceded by the standard hd and tl functions etc.
  4127 
  4128 A number of basic list functions are no longer exported to the ML
  4129 toplevel, as they are variants of predefined functions.  The following
  4130 suggests how one can translate existing code:
  4131 
  4132     rev_append xs ys = List.revAppend (xs, ys)
  4133     nth_elem (i, xs) = List.nth (xs, i)
  4134     last_elem xs = List.last xs
  4135     flat xss = List.concat xss
  4136     seq fs = List.app fs
  4137     partition P xs = List.partition P xs
  4138     mapfilter f xs = List.mapPartial f xs
  4139 
  4140 * Pure/library.ML: several combinators for linear functional
  4141 transformations, notably reverse application and composition:
  4142 
  4143   x |> f                f #> g
  4144   (x, y) |-> f          f #-> g
  4145 
  4146 * Pure/library.ML: introduced/changed precedence of infix operators:
  4147 
  4148   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4149   infix 2 ?;
  4150   infix 3 o oo ooo oooo;
  4151   infix 4 ~~ upto downto;
  4152 
  4153 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4154 infix operators.
  4155 
  4156 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4157 fold_map support linear functional transformations and nesting.  For
  4158 example:
  4159 
  4160   fold f [x1, ..., xN] y =
  4161     y |> f x1 |> ... |> f xN
  4162 
  4163   (fold o fold) f [xs1, ..., xsN] y =
  4164     y |> fold f xs1 |> ... |> fold f xsN
  4165 
  4166   fold f [x1, ..., xN] =
  4167     f x1 #> ... #> f xN
  4168 
  4169   (fold o fold) f [xs1, ..., xsN] =
  4170     fold f xs1 #> ... #> fold f xsN
  4171 
  4172 * Pure/library.ML: the following selectors on type 'a option are
  4173 available:
  4174 
  4175   the:               'a option -> 'a  (*partial*)
  4176   these:             'a option -> 'a  where 'a = 'b list
  4177   the_default: 'a -> 'a option -> 'a
  4178   the_list:          'a option -> 'a list
  4179 
  4180 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4181 basic operations for association lists, following natural argument
  4182 order; moreover the explicit equality predicate passed here avoids
  4183 potentially expensive polymorphic runtime equality checks.
  4184 The old functions may be expressed as follows:
  4185 
  4186   assoc = uncurry (AList.lookup (op =))
  4187   assocs = these oo AList.lookup (op =)
  4188   overwrite = uncurry (AList.update (op =)) o swap
  4189 
  4190 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4191 
  4192   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4193   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4194 
  4195 replacing make_keylist and keyfilter (occassionally used)
  4196 Naive rewrites:
  4197 
  4198   make_keylist = AList.make
  4199   keyfilter = AList.find (op =)
  4200 
  4201 * eq_fst and eq_snd now take explicit equality parameter, thus
  4202   avoiding eqtypes. Naive rewrites:
  4203 
  4204     eq_fst = eq_fst (op =)
  4205     eq_snd = eq_snd (op =)
  4206 
  4207 * Removed deprecated apl and apr (rarely used).
  4208   Naive rewrites:
  4209 
  4210     apl (n, op) =>>= curry op n
  4211     apr (op, m) =>>= fn n => op (n, m)
  4212 
  4213 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4214 provides a reasonably efficient light-weight implementation of sets as
  4215 lists.
  4216 
  4217 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4218 few new operations; existing lookup and update are now curried to
  4219 follow natural argument order (for use with fold etc.);
  4220 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4221 
  4222 * Pure/General: output via the Isabelle channels of
  4223 writeln/warning/error etc. is now passed through Output.output, with a
  4224 hook for arbitrary transformations depending on the print_mode
  4225 (cf. Output.add_mode -- the first active mode that provides a output
  4226 function wins).  Already formatted output may be embedded into further
  4227 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4228 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4229 accommodate easy composition of diagnostic messages etc.  Programmers
  4230 rarely need to care about Output.output or Output.raw at all, with
  4231 some notable exceptions: Output.output is required when bypassing the
  4232 standard channels (writeln etc.), or in token translations to produce
  4233 properly formatted results; Output.raw is required when capturing
  4234 already output material that will eventually be presented to the user
  4235 a second time.  For the default print mode, both Output.output and
  4236 Output.raw have no effect.
  4237 
  4238 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4239 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4240 cumulative results are displayed at the end of a batch session.
  4241 
  4242 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4243 replaced by File.platform_path and File.shell_path (with appropriate
  4244 hooks).  This provides a clean interface for unusual systems where the
  4245 internal and external process view of file names are different.
  4246 
  4247 * Pure: more efficient orders for basic syntactic entities: added
  4248 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4249 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4250 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4251 orders now -- potential INCOMPATIBILITY for code that depends on a
  4252 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4253 Library.sort_strings on result).
  4254 
  4255 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4256 fold_types traverse types/terms from left to right, observing natural
  4257 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4258 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4259 
  4260 * Pure: name spaces have been refined, with significant changes of the
  4261 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4262 to extern(_table).  The plain name entry path is superceded by a
  4263 general 'naming' context, which also includes the 'policy' to produce
  4264 a fully qualified name and external accesses of a fully qualified
  4265 name; NameSpace.extend is superceded by context dependent
  4266 Sign.declare_name.  Several theory and proof context operations modify
  4267 the naming context.  Especially note Theory.restore_naming and
  4268 ProofContext.restore_naming to get back to a sane state; note that
  4269 Theory.add_path is no longer sufficient to recover from
  4270 Theory.absolute_path in particular.
  4271 
  4272 * Pure: new flags short_names (default false) and unique_names
  4273 (default true) for controlling output of qualified names.  If
  4274 short_names is set, names are printed unqualified.  If unique_names is
  4275 reset, the name prefix is reduced to the minimum required to achieve
  4276 the original result when interning again, even if there is an overlap
  4277 with earlier declarations.
  4278 
  4279 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4280 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4281 (useful for printing error messages).  INCOMPATIBILITY.
  4282 
  4283 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4284 Theory.theory are now identified, referring to the universal
  4285 Context.theory (see Pure/context.ML).  Actual signature and theory
  4286 content is managed as theory data.  The old code and interfaces were
  4287 spread over many files and structures; the new arrangement introduces
  4288 considerable INCOMPATIBILITY to gain more clarity:
  4289 
  4290   Context -- theory management operations (name, identity, inclusion,
  4291     parents, ancestors, merge, etc.), plus generic theory data;
  4292 
  4293   Sign -- logical signature and syntax operations (declaring consts,
  4294     types, etc.), plus certify/read for common entities;
  4295 
  4296   Theory -- logical theory operations (stating axioms, definitions,
  4297     oracles), plus a copy of logical signature operations (consts,
  4298     types, etc.); also a few basic management operations (Theory.copy,
  4299     Theory.merge, etc.)
  4300 
  4301 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4302 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4303 for convenience -- they merely return the theory.
  4304 
  4305 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4306 
  4307 * Pure: the Isar proof context type is already defined early in Pure
  4308 as Context.proof (note that ProofContext.context and Proof.context are
  4309 aliases, where the latter is the preferred name).  This enables other
  4310 Isabelle components to refer to that type even before Isar is present.
  4311 
  4312 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4313 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4314 any of these kinds.  For example, Sign.intern typeK is now
  4315 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4316 Theory.hide_types.  Also note that former
  4317 Theory.hide_classes/types/consts are now
  4318 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4319 internalize their arguments!  INCOMPATIBILITY.
  4320 
  4321 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4322 datatype thmref (with constructors Name and NameSelection) instead of
  4323 plain string -- INCOMPATIBILITY;
  4324 
  4325 * Pure: cases produced by proof methods specify options, where NONE
  4326 means to remove case bindings -- INCOMPATIBILITY in
  4327 (RAW_)METHOD_CASES.
  4328 
  4329 * Pure: the following operations retrieve axioms or theorems from a
  4330 theory node or theory hierarchy, respectively:
  4331 
  4332   Theory.axioms_of: theory -> (string * term) list
  4333   Theory.all_axioms_of: theory -> (string * term) list
  4334   PureThy.thms_of: theory -> (string * thm) list
  4335   PureThy.all_thms_of: theory -> (string * thm) list
  4336 
  4337 * Pure: print_tac now outputs the goal through the trace channel.
  4338 
  4339 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4340 Reference Toplevel.debug (default false) controls detailed printing
  4341 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4342 controls execution profiling -- set to 1 for time and 2 for space
  4343 (both increase the runtime).
  4344 
  4345 * Isar session: The initial use of ROOT.ML is now always timed,
  4346 i.e. the log will show the actual process times, in contrast to the
  4347 elapsed wall-clock time that the outer shell wrapper produces.
  4348 
  4349 * Simplifier: improved handling of bound variables (nameless
  4350 representation, avoid allocating new strings).  Simprocs that invoke
  4351 the Simplifier recursively should use Simplifier.inherit_bounds to
  4352 avoid local name clashes.  Failure to do so produces warnings
  4353 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4354 for further details.
  4355 
  4356 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4357 bindings for all theorems stored within a given theory; this may help
  4358 in porting non-Isar theories to Isar ones, while keeping ML proof
  4359 scripts for the time being.
  4360 
  4361 * ML operator HTML.with_charset specifies the charset begin used for
  4362 generated HTML files.  For example:
  4363 
  4364   HTML.with_charset "utf-8" use_thy "Hebrew";
  4365   HTML.with_charset "utf-8" use_thy "Chinese";
  4366 
  4367 
  4368 *** System ***
  4369 
  4370 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4371 isabelle, isatool etc.).
  4372 
  4373 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4374 isatool doc, isatool mkdir, display_drafts etc.).
  4375 
  4376 * isatool usedir: option -f allows specification of the ML file to be
  4377 used by Isabelle; default is ROOT.ML.
  4378 
  4379 * New isatool version outputs the version identifier of the Isabelle
  4380 distribution being used.
  4381 
  4382 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4383 (containing Boolean satisfiability problems) into Isabelle/HOL
  4384 theories.
  4385 
  4386 
  4387 
  4388 New in Isabelle2004 (April 2004)
  4389 --------------------------------
  4390 
  4391 *** General ***
  4392 
  4393 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4394   Replaces linorder.ML.
  4395 
  4396 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4397   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4398   (\<a>...\<z>), are now considered normal letters, and can therefore
  4399   be used anywhere where an ASCII letter (a...zA...Z) has until
  4400   now. COMPATIBILITY: This obviously changes the parsing of some
  4401   terms, especially where a symbol has been used as a binder, say
  4402   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4403   as an identifier.  Fix it by inserting a space around former
  4404   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4405   existing theory and ML files.
  4406 
  4407 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4408 
  4409 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4410   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4411   a normal (but invisible) letter. For multiple letter subscripts repeat
  4412   \<^isub> like this: x\<^isub>1\<^isub>2.
  4413 
  4414 * Pure: There are now sub-/superscripts that can span more than one
  4415   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4416   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4417   superscript. The new control characters are not identifier parts.
  4418 
  4419 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4420   content of "..." to the latex file instead of \isacntrl... . The "..."
  4421   may consist of any printable characters excluding the end bracket >.
  4422 
  4423 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4424   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4425   declare constants "final", which prevents their being given a definition
  4426   later.  It is useful for constants whose behaviour is fixed axiomatically
  4427   rather than definitionally, such as the meta-logic connectives.
  4428 
  4429 * Pure: 'instance' now handles general arities with general sorts
  4430   (i.e. intersections of classes),
  4431 
  4432 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4433   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4434   It can be changed to alter the colors/layout of generated pages.
  4435 
  4436 
  4437 *** Isar ***
  4438 
  4439 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4440   cut_tac, subgoal_tac and thin_tac:
  4441   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4442     locales are no longer forced to write Isar proof scripts.
  4443     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4444     emulations.
  4445   - INCOMPATIBILITY: names of variables to be instantiated may no
  4446     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4447     This is consistent with the instantiation attribute "where".
  4448 
  4449 * Attributes "where" and "of":
  4450   - Now take type variables of instantiated theorem into account when reading
  4451     the instantiation string.  This fixes a bug that caused instantiated
  4452     theorems to have too special types in some circumstances.
  4453   - "where" permits explicit instantiations of type variables.
  4454 
  4455 * Calculation commands "moreover" and "also" no longer interfere with
  4456   current facts ("this"), admitting arbitrary combinations with "then"
  4457   and derived forms.
  4458 
  4459 * Locales:
  4460   - Goal statements involving the context element "includes" no longer
  4461     generate theorems with internal delta predicates (those ending on
  4462     "_axioms") in the premise.
  4463     Resolve particular premise with <locale>.intro to obtain old form.
  4464   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4465     specification and "includes" elements in goal statement.
  4466   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4467     [intro?] and [elim?] (respectively) by default.
  4468   - Experimental command for instantiation of locales in proof contexts:
  4469         instantiate <label>[<attrs>]: <loc>
  4470     Instantiates locale <loc> and adds all its theorems to the current context
  4471     taking into account their attributes.  Label and attrs are optional
  4472     modifiers, like in theorem declarations.  If present, names of
  4473     instantiated theorems are qualified with <label>, and the attributes
  4474     <attrs> are applied after any attributes these theorems might have already.
  4475       If the locale has assumptions, a chained fact of the form
  4476     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4477     are derived.  The command does not support old-style locales declared
  4478     with "locale (open)".
  4479       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4480 
  4481 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4482   (Isar) contexts.
  4483 
  4484 
  4485 *** HOL ***
  4486 
  4487 * Proof import: new image HOL4 contains the imported library from
  4488   the HOL4 system with about 2500 theorems. It is imported by
  4489   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4490   can be used like any other Isabelle image.  See
  4491   HOL/Import/HOL/README for more information.
  4492 
  4493 * Simplifier:
  4494   - Much improved handling of linear and partial orders.
  4495     Reasoners for linear and partial orders are set up for type classes
  4496     "linorder" and "order" respectively, and are added to the default simpset
  4497     as solvers.  This means that the simplifier can build transitivity chains
  4498     to solve goals from the assumptions.
  4499   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4500     of blast or auto after simplification become unnecessary because the goal
  4501     is solved by simplification already.
  4502 
  4503 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4504     all proved in axiomatic type classes for semirings, rings and fields.
  4505 
  4506 * Numerics:
  4507   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4508     now formalized using the Ring_and_Field theory mentioned above.
  4509   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4510     than before, because now they are set up once in a generic manner.
  4511   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4512     Look for the general versions in Ring_and_Field (and Power if they concern
  4513     exponentiation).
  4514 
  4515 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4516 
  4517 * Records:
  4518   - Record types are now by default printed with their type abbreviation
  4519     instead of the list of all field types. This can be configured via
  4520     the reference "print_record_type_abbr".
  4521   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4522     (not enabled by default).
  4523   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4524     EX x. x = sel r to True (not enabled by default).
  4525   - Tactic "record_split_simp_tac" to split and simplify records added.
  4526 
  4527 * 'specification' command added, allowing for definition by
  4528   specification.  There is also an 'ax_specification' command that
  4529   introduces the new constants axiomatically.
  4530 
  4531 * arith(_tac) is now able to generate counterexamples for reals as well.
  4532 
  4533 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4534 
  4535 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4536   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4537 
  4538 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4539   matrix theory to linear programming.
  4540 
  4541 * Unions and Intersections:
  4542   The latex output syntax of UN and INT has been changed
  4543   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4544   i.e. the index formulae has become a subscript.
  4545   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4546 
  4547 * Unions and Intersections over Intervals:
  4548   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4549   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4550   like in normal math, and corresponding versions for < and for intersection.
  4551 
  4552 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4553   lexicographic dictonary ordering has been added as "lexord".
  4554 
  4555 * ML: the legacy theory structures Int and List have been removed. They had
  4556   conflicted with ML Basis Library structures having the same names.
  4557 
  4558 * 'refute' command added to search for (finite) countermodels.  Only works
  4559   for a fragment of HOL.  The installation of an external SAT solver is
  4560   highly recommended.  See "HOL/Refute.thy" for details.
  4561 
  4562 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4563   formulae under an assignment of free variables to random values.
  4564   In contrast to 'refute', it can deal with inductive datatypes,
  4565   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4566   for examples.
  4567 
  4568 
  4569 *** HOLCF ***
  4570 
  4571 * Streams now come with concatenation and are part of the HOLCF image
  4572 
  4573 
  4574 
  4575 New in Isabelle2003 (May 2003)
  4576 ------------------------------
  4577 
  4578 *** General ***
  4579 
  4580 * Provers/simplifier:
  4581 
  4582   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4583     Assumptions are now subject to complete mutual simplification,
  4584     not just from left to right. The simplifier now preserves
  4585     the order of assumptions.
  4586 
  4587     Potential INCOMPATIBILITY:
  4588 
  4589     -- simp sometimes diverges where the old version did
  4590        not, e.g. invoking simp on the goal
  4591 
  4592         [| P (f x); y = x; f x = f y |] ==> Q
  4593 
  4594        now gives rise to the infinite reduction sequence
  4595 
  4596         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4597 
  4598        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4599        kind of problem.
  4600 
  4601     -- Tactics combining classical reasoner and simplification (such as auto)
  4602        are also affected by this change, because many of them rely on
  4603        simp. They may sometimes diverge as well or yield a different numbers
  4604        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4605        in case of problems. Sometimes subsequent calls to the classical
  4606        reasoner will fail because a preceeding call to the simplifier too
  4607        eagerly simplified the goal, e.g. deleted redundant premises.
  4608 
  4609   - The simplifier trace now shows the names of the applied rewrite rules
  4610 
  4611   - You can limit the number of recursive invocations of the simplifier
  4612     during conditional rewriting (where the simplifie tries to solve the
  4613     conditions before applying the rewrite rule):
  4614     ML "simp_depth_limit := n"
  4615     where n is an integer. Thus you can force termination where previously
  4616     the simplifier would diverge.
  4617 
  4618   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4619 
  4620   - No longer aborts on failed congruence proof.  Instead, the
  4621     congruence is ignored.
  4622 
  4623 * Pure: New generic framework for extracting programs from constructive
  4624   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4625   as HOL/Extraction for some case studies.
  4626 
  4627 * Pure: The main goal of the proof state is no longer shown by default, only
  4628 the subgoals. This behaviour is controlled by a new flag.
  4629    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4630 (ML: Proof.show_main_goal).
  4631 
  4632 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4633 rules whose conclusion matches subgoal 1:
  4634       PG menu: Isabelle/Isar -> Show me -> matching rules
  4635 The rules are ordered by how closely they match the subgoal.
  4636 In particular, rules that solve a subgoal outright are displayed first
  4637 (or rather last, the way they are printed).
  4638 (ML: ProofGeneral.print_intros())
  4639 
  4640 * Pure: New flag trace_unify_fail causes unification to print
  4641 diagnostic information (PG: in trace buffer) when it fails. This is
  4642 useful for figuring out why single step proofs like rule, erule or
  4643 assumption failed.
  4644 
  4645 * Pure: Locale specifications now produce predicate definitions
  4646 according to the body of text (covering assumptions modulo local
  4647 definitions); predicate "loc_axioms" covers newly introduced text,
  4648 while "loc" is cumulative wrt. all included locale expressions; the
  4649 latter view is presented only on export into the global theory
  4650 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4651 on the old view without predicates;
  4652 
  4653 * Pure: predefined locales "var" and "struct" are useful for sharing
  4654 parameters (as in CASL, for example); just specify something like
  4655 ``var x + var y + struct M'' as import;
  4656 
  4657 * Pure: improved thms_containing: proper indexing of facts instead of
  4658 raw theorems; check validity of results wrt. current name space;
  4659 include local facts of proof configuration (also covers active
  4660 locales), cover fixed variables in index; may use "_" in term
  4661 specification; an optional limit for the number of printed facts may
  4662 be given (the default is 40);
  4663 
  4664 * Pure: disallow duplicate fact bindings within new-style theory files
  4665 (batch-mode only);
  4666 
  4667 * Provers: improved induct method: assumptions introduced by case
  4668 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4669 the goal statement); "foo" still refers to all facts collectively;
  4670 
  4671 * Provers: the function blast.overloaded has been removed: all constants
  4672 are regarded as potentially overloaded, which improves robustness in exchange
  4673 for slight decrease in efficiency;
  4674 
  4675 * Provers/linorder: New generic prover for transitivity reasoning over
  4676 linear orders.  Note: this prover is not efficient!
  4677 
  4678 * Isar: preview of problems to finish 'show' now produce an error
  4679 rather than just a warning (in interactive mode);
  4680 
  4681 
  4682 *** HOL ***
  4683 
  4684 * arith(_tac)
  4685 
  4686  - Produces a counter example if it cannot prove a goal.
  4687    Note that the counter example may be spurious if the goal is not a formula
  4688    of quantifier-free linear arithmetic.
  4689    In ProofGeneral the counter example appears in the trace buffer.
  4690 
  4691  - Knows about div k and mod k where k is a numeral of type nat or int.
  4692 
  4693  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4694    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4695    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4696 
  4697 * simp's arithmetic capabilities have been enhanced a bit: it now
  4698 takes ~= in premises into account (by performing a case split);
  4699 
  4700 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4701 are distributed over a sum of terms;
  4702 
  4703 * New tactic "trans_tac" and method "trans" instantiate
  4704 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4705 "<=", "<" and "=").
  4706 
  4707 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4708 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4709 
  4710 * 'typedef' command has new option "open" to suppress the set
  4711 definition;
  4712 
  4713 * functions Min and Max on finite sets have been introduced (theory
  4714 Finite_Set);
  4715 
  4716 * attribute [symmetric] now works for relations as well; it turns
  4717 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4718 
  4719 * induct over a !!-quantified statement (say !!x1..xn):
  4720   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4721 
  4722 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4723 %x. None. Warning: empty_def now refers to the previously hidden definition
  4724 of the empty set.
  4725 
  4726 * Algebra: formalization of classical algebra.  Intended as base for
  4727 any algebraic development in Isabelle.  Currently covers group theory
  4728 (up to Sylow's theorem) and ring theory (Universal Property of
  4729 Univariate Polynomials).  Contributions welcome;
  4730 
  4731 * GroupTheory: deleted, since its material has been moved to Algebra;
  4732 
  4733 * Complex: new directory of the complex numbers with numeric constants,
  4734 nonstandard complex numbers, and some complex analysis, standard and
  4735 nonstandard (Jacques Fleuriot);
  4736 
  4737 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4738 
  4739 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4740 Fleuriot);
  4741 
  4742 * Real/HahnBanach: updated and adapted to locales;
  4743 
  4744 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4745 Gray and Kramer);
  4746 
  4747 * UNITY: added the Meier-Sanders theory of progress sets;
  4748 
  4749 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4750 as abstract algorithms, instantiated to the JVM;
  4751 
  4752 * Bali: Java source language formalization. Type system, operational
  4753 semantics, axiomatic semantics. Supported language features:
  4754 classes, interfaces, objects,virtual methods, static methods,
  4755 static/instance fields, arrays, access modifiers, definite
  4756 assignment, exceptions.
  4757 
  4758 
  4759 *** ZF ***
  4760 
  4761 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4762 universe, etc.);
  4763 
  4764 * Main ZF: virtually all theories converted to new-style format;
  4765 
  4766 
  4767 *** ML ***
  4768 
  4769 * Pure: Tactic.prove provides sane interface for internal proofs;
  4770 omits the infamous "standard" operation, so this is more appropriate
  4771 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4772 
  4773 * Pure: improved error reporting of simprocs;
  4774 
  4775 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4776 up simprocs;
  4777 
  4778 
  4779 *** Document preparation ***
  4780 
  4781 * uses \par instead of \\ for line breaks in theory text. This may
  4782 shift some page breaks in large documents. To get the old behaviour
  4783 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4784 
  4785 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4786 other packages
  4787 
  4788 * \<euro> now needs package babel/greek instead of marvosym (which
  4789 broke \Rightarrow)
  4790 
  4791 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4792 textcomp package)
  4793 
  4794 
  4795 
  4796 New in Isabelle2002 (March 2002)
  4797 --------------------------------
  4798 
  4799 *** Document preparation ***
  4800 
  4801 * greatly simplified document preparation setup, including more
  4802 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4803 instructive isatool mkdir; users should basically be able to get
  4804 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4805 users may run a separate document processing stage manually like this:
  4806 "isatool usedir -D output HOL Test && isatool document Test/output";
  4807 
  4808 * theory dependency graph may now be incorporated into documents;
  4809 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4810 with \includegraphics of LaTeX;
  4811 
  4812 * proper spacing of consecutive markup elements, especially text
  4813 blocks after section headings;
  4814 
  4815 * support bold style (for single symbols only), input syntax is like
  4816 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4817 
  4818 * \<bullet> is now output as bold \cdot by default, which looks much
  4819 better in printed text;
  4820 
  4821 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4822 note that these symbols are currently unavailable in Proof General /
  4823 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4824 
  4825 * isatool latex no longer depends on changed TEXINPUTS, instead
  4826 isatool document copies the Isabelle style files to the target
  4827 location;
  4828 
  4829 
  4830 *** Isar ***
  4831 
  4832 * Pure/Provers: improved proof by cases and induction;
  4833   - 'case' command admits impromptu naming of parameters (such as
  4834     "case (Suc n)");
  4835   - 'induct' method divinates rule instantiation from the inductive
  4836     claim; no longer requires excessive ?P bindings for proper
  4837     instantiation of cases;
  4838   - 'induct' method properly enumerates all possibilities of set/type
  4839     rules; as a consequence facts may be also passed through *type*
  4840     rules without further ado;
  4841   - 'induct' method now derives symbolic cases from the *rulified*
  4842     rule (before it used to rulify cases stemming from the internal
  4843     atomized version); this means that the context of a non-atomic
  4844     statement becomes is included in the hypothesis, avoiding the
  4845     slightly cumbersome show "PROP ?case" form;
  4846   - 'induct' may now use elim-style induction rules without chaining
  4847     facts, using ``missing'' premises from the goal state; this allows
  4848     rules stemming from inductive sets to be applied in unstructured
  4849     scripts, while still benefitting from proper handling of non-atomic
  4850     statements; NB: major inductive premises need to be put first, all
  4851     the rest of the goal is passed through the induction;
  4852   - 'induct' proper support for mutual induction involving non-atomic
  4853     rule statements (uses the new concept of simultaneous goals, see
  4854     below);
  4855   - append all possible rule selections, but only use the first
  4856     success (no backtracking);
  4857   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4858   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4859   - added 'print_induct_rules' (covered by help item in recent Proof
  4860     General versions);
  4861   - moved induct/cases attributes to Pure, methods to Provers;
  4862   - generic method setup instantiated for FOL and HOL;
  4863 
  4864 * Pure: support multiple simultaneous goal statements, for example
  4865 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4866 meta-level mechanism, this acts as if several individual goals had
  4867 been stated separately; in particular common proof methods need to be
  4868 repeated in order to cover all claims; note that a single elimination
  4869 step is *not* sufficient to establish the two conjunctions, so this
  4870 fails:
  4871 
  4872   assume "A & B" then have A and B ..   (*".." fails*)
  4873 
  4874 better use "obtain" in situations as above; alternative refer to
  4875 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4876 
  4877 * Pure: proper integration with ``locales''; unlike the original
  4878 version by Florian Kammller, Isar locales package high-level proof
  4879 contexts rather than raw logical ones (e.g. we admit to include
  4880 attributes everywhere); operations on locales include merge and
  4881 rename; support for implicit arguments (``structures''); simultaneous
  4882 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4883 some examples;
  4884 
  4885 * Pure: the following commands have been ``localized'', supporting a
  4886 target locale specification "(in name)": 'lemma', 'theorem',
  4887 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4888 stored both within the locale and at the theory level (exported and
  4889 qualified by the locale name);
  4890 
  4891 * Pure: theory goals may now be specified in ``long'' form, with
  4892 ad-hoc contexts consisting of arbitrary locale elements. for example
  4893 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4894 definitions may be given, too); the result is a meta-level rule with
  4895 the context elements being discharged in the obvious way;
  4896 
  4897 * Pure: new proof command 'using' allows to augment currently used
  4898 facts after a goal statement ('using' is syntactically analogous to
  4899 'apply', but acts on the goal's facts only); this allows chained facts
  4900 to be separated into parts given before and after a claim, as in
  4901 ``from a and b have C using d and e <proof>'';
  4902 
  4903 * Pure: renamed "antecedent" case to "rule_context";
  4904 
  4905 * Pure: new 'judgment' command records explicit information about the
  4906 object-logic embedding (used by several tools internally); no longer
  4907 use hard-wired "Trueprop";
  4908 
  4909 * Pure: added 'corollary' command;
  4910 
  4911 * Pure: fixed 'token_translation' command;
  4912 
  4913 * Pure: removed obsolete 'exported' attribute;
  4914 
  4915 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4916 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4917 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4918 
  4919 * Pure: method 'atomize' presents local goal premises as object-level
  4920 statements (atomic meta-level propositions); setup controlled via
  4921 rewrite rules declarations of 'atomize' attribute; example
  4922 application: 'induct' method with proper rule statements in improper
  4923 proof *scripts*;
  4924 
  4925 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4926 now consider the syntactic context of assumptions, giving a better
  4927 chance to get type-inference of the arguments right (this is
  4928 especially important for locales);
  4929 
  4930 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4931 mode;
  4932 
  4933 * Pure/obtain: the formal conclusion "thesis", being marked as
  4934 ``internal'', may no longer be reference directly in the text;
  4935 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4936 situations;
  4937 
  4938 * Pure: generic 'sym' attribute which declares a rule both as pure
  4939 'elim?' and for the 'symmetric' operation;
  4940 
  4941 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4942 text; the fixed correlation with particular command syntax has been
  4943 discontinued;
  4944 
  4945 * Pure: new method 'rules' is particularly well-suited for proof
  4946 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4947 but often produces more compact proof terms with less detours;
  4948 
  4949 * Pure/Provers/classical: simplified integration with pure rule
  4950 attributes and methods; the classical "intro?/elim?/dest?"
  4951 declarations coincide with the pure ones; the "rule" method no longer
  4952 includes classically swapped intros; "intro" and "elim" methods no
  4953 longer pick rules from the context; also got rid of ML declarations
  4954 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4955 INCOMPATIBILITY;
  4956 
  4957 * Provers/classical: attribute 'swapped' produces classical inversions
  4958 of introduction rules;
  4959 
  4960 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4961 rules instead of full simplifier context; 'iff' attribute handles
  4962 conditional rules;
  4963 
  4964 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4965 
  4966 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4967 "(permissive)" option to recover old behavior;
  4968 
  4969 * HOL: 'inductive' no longer features separate (collective) attributes
  4970 for 'intros' (was found too confusing);
  4971 
  4972 * HOL: properly declared induction rules less_induct and
  4973 wf_induct_rule;
  4974 
  4975 
  4976 *** HOL ***
  4977 
  4978 * HOL: moved over to sane numeral syntax; the new policy is as
  4979 follows:
  4980 
  4981   - 0 and 1 are polymorphic constants, which are defined on any
  4982   numeric type (nat, int, real etc.);
  4983 
  4984   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4985   binary representation internally;
  4986 
  4987   - type nat has special constructor Suc, and generally prefers Suc 0
  4988   over 1::nat and Suc (Suc 0) over 2::nat;
  4989 
  4990 This change may cause significant problems of INCOMPATIBILITY; here
  4991 are some hints on converting existing sources:
  4992 
  4993   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4994   entities, so expressions involving "-" (unary or binary minus) need
  4995   to be spaced properly;
  4996 
  4997   - existing occurrences of "1" may need to be constraint "1::nat" or
  4998   even replaced by Suc 0; similar for old "2";
  4999 
  5000   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5001 
  5002   - remove all special provisions on numerals in proofs;
  5003 
  5004 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5005 representation (depends on bin_arith_simps in the default context);
  5006 
  5007 * HOL: symbolic syntax for x^2 (numeral 2);
  5008 
  5009 * HOL: the class of all HOL types is now called "type" rather than
  5010 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5011 in axclass/classes, instance/arities, and (usually rare) occurrences
  5012 in typings (of consts etc.); internally the class is called
  5013 "HOL.type", ML programs should refer to HOLogic.typeS;
  5014 
  5015 * HOL/record package improvements:
  5016   - new derived operations "fields" to build a partial record section,
  5017     "extend" to promote a fixed record to a record scheme, and
  5018     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5019     declared as simp by default;
  5020   - shared operations ("more", "fields", etc.) now need to be always
  5021     qualified) --- potential INCOMPATIBILITY;
  5022   - removed "make_scheme" operations (use "make" with "extend") --
  5023     INCOMPATIBILITY;
  5024   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5025   - provides cases/induct rules for use with corresponding Isar
  5026     methods (for concrete records, record schemes, concrete more
  5027     parts, and schematic more parts -- in that order);
  5028   - internal definitions directly based on a light-weight abstract
  5029     theory of product types over typedef rather than datatype;
  5030 
  5031 * HOL: generic code generator for generating executable ML code from
  5032 specifications; specific support for HOL constructs such as inductive
  5033 datatypes and sets, as well as recursive functions; can be invoked
  5034 via 'generate_code' theory section;
  5035 
  5036 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5037 
  5038 * HOL: consolidated and renamed several theories.  In particular:
  5039         Ord.thy has been absorbed into HOL.thy
  5040         String.thy has been absorbed into List.thy
  5041 
  5042 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5043 (beware of argument permutation!);
  5044 
  5045 * HOL: linorder_less_split superseded by linorder_cases;
  5046 
  5047 * HOL/List: "nodups" renamed to "distinct";
  5048 
  5049 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5050 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5051   - Ex_def has changed, now need to use some_eq_ex
  5052 
  5053 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5054 in this (rare) case use:
  5055 
  5056   delSWrapper "split_all_tac"
  5057   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5058 
  5059 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5060 MAY FAIL;
  5061 
  5062 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5063 Isabelle's type classes, ^ on functions and relations has too general
  5064 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5065 necessary to attach explicit type constraints;
  5066 
  5067 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5068 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5069 renamed accordingly (eg "compI" -> "rel_compI").
  5070 
  5071 * HOL: syntax translations now work properly with numerals and records
  5072 expressions;
  5073 
  5074 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5075 of "lam" -- INCOMPATIBILITY;
  5076 
  5077 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5078 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5079 renamed "Product_Type.unit";
  5080 
  5081 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5082 
  5083 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5084 the "cases" method);
  5085 
  5086 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5087 Florian Kammller);
  5088 
  5089 * HOL/IMP: updated and converted to new-style theory format; several
  5090 parts turned into readable document, with proper Isar proof texts and
  5091 some explanations (by Gerwin Klein);
  5092 
  5093 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5094 
  5095 * HOL-Hyperreal is now a logic image;
  5096 
  5097 
  5098 *** HOLCF ***
  5099 
  5100 * Isar: consts/constdefs supports mixfix syntax for continuous
  5101 operations;
  5102 
  5103 * Isar: domain package adapted to new-style theory format, e.g. see
  5104 HOLCF/ex/Dnat.thy;
  5105 
  5106 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5107 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5108 lift.induct_tac, always use UU instead of Undef;
  5109 
  5110 * HOLCF/IMP: updated and converted to new-style theory;
  5111 
  5112 
  5113 *** ZF ***
  5114 
  5115 * Isar: proper integration of logic-specific tools and packages,
  5116 including theory commands '(co)inductive', '(co)datatype',
  5117 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5118 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5119 
  5120 * theory Main no longer includes AC; for the Axiom of Choice, base
  5121 your theory on Main_ZFC;
  5122 
  5123 * the integer library now covers quotients and remainders, with many
  5124 laws relating division to addition, multiplication, etc.;
  5125 
  5126 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5127 typeless version of the formalism;
  5128 
  5129 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5130 format;
  5131 
  5132 * ZF/Induct: new directory for examples of inductive definitions,
  5133 including theory Multiset for multiset orderings; converted to
  5134 new-style theory format;
  5135 
  5136 * ZF: many new theorems about lists, ordinals, etc.;
  5137 
  5138 
  5139 *** General ***
  5140 
  5141 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5142 variable proof controls level of detail: 0 = no proofs (only oracle
  5143 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5144 also ref manual for further ML interfaces;
  5145 
  5146 * Pure/axclass: removed obsolete ML interface
  5147 goal_subclass/goal_arity;
  5148 
  5149 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5150 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5151 separate tokens, so expressions involving minus need to be spaced
  5152 properly;
  5153 
  5154 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5155 rather than "infixl" or "infixr";
  5156 
  5157 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5158 sort constraint specifications in type inference; e.g. "x::_::foo"
  5159 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5160 type variable);
  5161 
  5162 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5163 control output of nested => (types); the default behavior is
  5164 "type_brackets";
  5165 
  5166 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5167 tokens into AST constants;
  5168 
  5169 * Pure/syntax: prefer later declarations of translations and print
  5170 translation functions; potential INCOMPATIBILITY: need to reverse
  5171 multiple declarations for same syntax element constant;
  5172 
  5173 * Pure/show_hyps reset by default (in accordance to existing Isar
  5174 practice);
  5175 
  5176 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5177 addSafter;
  5178 
  5179 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5180 as well;
  5181 
  5182 * system: tested support for MacOS X; should be able to get Isabelle +
  5183 Proof General to work in a plain Terminal after installing Poly/ML
  5184 (e.g. from the Isabelle distribution area) and GNU bash alone
  5185 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5186 support requires further installations, e.g. from
  5187 http://fink.sourceforge.net/);
  5188 
  5189 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5190 
  5191 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5192 of 40 MB), cf. ML_OPTIONS;
  5193 
  5194 * system: Proof General keywords specification is now part of the
  5195 Isabelle distribution (see etc/isar-keywords.el);
  5196 
  5197 * system: support for persistent Proof General sessions (refrain from
  5198 outdating all loaded theories on startup); user may create writable
  5199 logic images like this: ``isabelle -q HOL Test'';
  5200 
  5201 * system: smart selection of Isabelle process versus Isabelle
  5202 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5203 run both "isabelle" and "Isabelle" even if file names are badly
  5204 damaged (executable inspects the case of the first letter of its own
  5205 name); added separate "isabelle-process" and "isabelle-interface";
  5206 
  5207 * system: refrain from any attempt at filtering input streams; no
  5208 longer support ``8bit'' encoding of old isabelle font, instead proper
  5209 iso-latin characters may now be used; the related isatools
  5210 "symbolinput" and "nonascii" have disappeared as well;
  5211 
  5212 * system: removed old "xterm" interface (the print modes "xterm" and
  5213 "xterm_color" are still available for direct use in a suitable
  5214 terminal);
  5215 
  5216 
  5217 
  5218 New in Isabelle99-2 (February 2001)
  5219 -----------------------------------
  5220 
  5221 *** Overview of INCOMPATIBILITIES ***
  5222 
  5223 * HOL: please note that theories in the Library and elsewhere often use the
  5224 new-style (Isar) format; to refer to their theorems in an ML script you must
  5225 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5226 
  5227 * HOL: inductive package no longer splits induction rule aggressively,
  5228 but only as far as specified by the introductions given; the old
  5229 format may be recovered via ML function complete_split_rule or attribute
  5230 'split_rule (complete)';
  5231 
  5232 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5233 gfp_Tarski to gfp_unfold;
  5234 
  5235 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5236 
  5237 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5238 relation); infix "^^" has been renamed "``"; infix "``" has been
  5239 renamed "`"; "univalent" has been renamed "single_valued";
  5240 
  5241 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5242 operation;
  5243 
  5244 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5245 
  5246 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5247 
  5248 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5249 consequence, it is no longer monotonic wrt. the local goal context
  5250 (which is now passed through the inductive cases);
  5251 
  5252 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5253 \<gg> to \<ggreater>;
  5254 
  5255 
  5256 *** Document preparation ***
  5257 
  5258 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5259 available: are "it" for near math-mode best-style output, "sl" for
  5260 slanted text style, and "tt" for plain type-writer; if no
  5261 \isabellestyle command is given, output is according to slanted
  5262 type-writer);
  5263 
  5264 * support sub/super scripts (for single symbols only), input syntax is
  5265 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5266 
  5267 * some more standard symbols; see Appendix A of the system manual for
  5268 the complete list of symbols defined in isabellesym.sty;
  5269 
  5270 * improved isabelle style files; more abstract symbol implementation
  5271 (should now use \isamath{...} and \isatext{...} in custom symbol
  5272 definitions);
  5273 
  5274 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5275 state; Note that presentation of goal states does not conform to
  5276 actual human-readable proof documents.  Please do not include goal
  5277 states into document output unless you really know what you are doing!
  5278 
  5279 * proper indentation of antiquoted output with proportional LaTeX
  5280 fonts;
  5281 
  5282 * no_document ML operator temporarily disables LaTeX document
  5283 generation;
  5284 
  5285 * isatool unsymbolize tunes sources for plain ASCII communication;
  5286 
  5287 
  5288 *** Isar ***
  5289 
  5290 * Pure: Isar now suffers initial goal statements to contain unbound
  5291 schematic variables (this does not conform to actual readable proof
  5292 documents, due to unpredictable outcome and non-compositional proof
  5293 checking); users who know what they are doing may use schematic goals
  5294 for Prolog-style synthesis of proven results;
  5295 
  5296 * Pure: assumption method (an implicit finishing) now handles actual
  5297 rules as well;
  5298 
  5299 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5300 initial goal, declare "that" only as Pure intro (only for single
  5301 steps); the "that" rule assumption may now be involved in implicit
  5302 finishing, thus ".." becomes a feasible for trivial obtains;
  5303 
  5304 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5305 instance proofs may be performed by "..";
  5306 
  5307 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5308 statements as well;
  5309 
  5310 * Pure: more robust selection of calculational rules;
  5311 
  5312 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5313 rule (as well as the assumption rule);
  5314 
  5315 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5316 lemmas, using the graph browser tool;
  5317 
  5318 * Pure: predict failure of "show" in interactive mode;
  5319 
  5320 * Pure: 'thms_containing' now takes actual terms as arguments;
  5321 
  5322 * HOL: improved method 'induct' --- now handles non-atomic goals
  5323 (potential INCOMPATIBILITY); tuned error handling;
  5324 
  5325 * HOL: cases and induct rules now provide explicit hints about the
  5326 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5327 any remaining facts are inserted into the goal verbatim;
  5328 
  5329 * HOL: local contexts (aka cases) may now contain term bindings as
  5330 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5331 the result to be shown in each case;
  5332 
  5333 * HOL: added 'recdef_tc' command;
  5334 
  5335 * isatool convert assists in eliminating legacy ML scripts;
  5336 
  5337 
  5338 *** HOL ***
  5339 
  5340 * HOL/Library: a collection of generic theories to be used together
  5341 with main HOL; the theory loader path already includes this directory
  5342 by default; the following existing theories have been moved here:
  5343 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5344 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5345 
  5346 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5347 modelling and verification task performed in Isabelle/HOL +
  5348 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5349 
  5350 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5351 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5352 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5353 'domain', this makes the theory consistent with mathematical
  5354 literature;
  5355 
  5356 * HOL basics: added overloaded operations "inverse" and "divide"
  5357 (infix "/"), syntax for generic "abs" operation, generic summation
  5358 operator \<Sum>;
  5359 
  5360 * HOL/typedef: simplified package, provide more useful rules (see also
  5361 HOL/subset.thy);
  5362 
  5363 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5364 now expressed as a proper nested rule (old-style tactic scripts may
  5365 require atomize_strip_tac to cope with non-atomic premises);
  5366 
  5367 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5368 to "split_conv" (old name still available for compatibility);
  5369 
  5370 * HOL: improved concrete syntax for strings (e.g. allows translation
  5371 rules with string literals);
  5372 
  5373 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5374  and Fleuriot's mechanization of analysis, including the transcendental
  5375  functions for the reals;
  5376 
  5377 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5378 
  5379 
  5380 *** CTT ***
  5381 
  5382 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5383 "lam" is displayed as TWO lambda-symbols
  5384 
  5385 * CTT: theory Main now available, containing everything (that is, Bool
  5386 and Arith);
  5387 
  5388 
  5389 *** General ***
  5390 
  5391 * Pure: the Simplifier has been implemented properly as a derived rule
  5392 outside of the actual kernel (at last!); the overall performance
  5393 penalty in practical applications is about 50%, while reliability of
  5394 the Isabelle inference kernel has been greatly improved;
  5395 
  5396 * print modes "brackets" and "no_brackets" control output of nested =>
  5397 (types) and ==> (props); the default behaviour is "brackets";
  5398 
  5399 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5400 as assumptions as well;
  5401 
  5402 * system: support Poly/ML 4.0;
  5403 
  5404 * system: isatool install handles KDE version 1 or 2;
  5405 
  5406 
  5407 
  5408 New in Isabelle99-1 (October 2000)
  5409 ----------------------------------
  5410 
  5411 *** Overview of INCOMPATIBILITIES ***
  5412 
  5413 * HOL: simplification of natural numbers is much changed; to partly
  5414 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5415 issue the following ML commands:
  5416 
  5417   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5418   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5419 
  5420 * HOL: simplification no longer dives into case-expressions; this is
  5421 controlled by "t.weak_case_cong" for each datatype t;
  5422 
  5423 * HOL: nat_less_induct renamed to less_induct;
  5424 
  5425 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5426 fixsome to patch .thy and .ML sources automatically;
  5427 
  5428   select_equality  -> some_equality
  5429   select_eq_Ex     -> some_eq_ex
  5430   selectI2EX       -> someI2_ex
  5431   selectI2         -> someI2
  5432   selectI          -> someI
  5433   select1_equality -> some1_equality
  5434   Eps_sym_eq       -> some_sym_eq_trivial
  5435   Eps_eq           -> some_eq_trivial
  5436 
  5437 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5438 
  5439 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5440 instead);
  5441 
  5442 * HOL: the recursion equations generated by 'recdef' are now called
  5443 f.simps instead of f.rules;
  5444 
  5445 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5446 
  5447 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5448 sometimes be needed;
  5449 
  5450 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5451 
  5452 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5453 
  5454 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5455 product is now "<*>" instead of "Times"; the lexicographic product is
  5456 now "<*lex*>" instead of "**";
  5457 
  5458 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5459 of main HOL, but was unused); better use HOL's datatype package;
  5460 
  5461 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5462 the old syntax may be recovered as follows:
  5463 
  5464   syntax (symbols)
  5465     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5466       (infixl "\\<oplus>" 100)
  5467 
  5468 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5469 
  5470 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5471 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5472 internally;
  5473 
  5474 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5475 changed from A/r to A//r;
  5476 
  5477 * ZF: new treatment of arithmetic (nat & int) may break some old
  5478 proofs;
  5479 
  5480 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5481 rulify -> rule_format, elimify -> elim_format, ...);
  5482 
  5483 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5484 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5485 should have to change intro!! to intro? only); replaced "delrule" by
  5486 "rule del";
  5487 
  5488 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5489 
  5490 * Provers: strengthened force_tac by using new first_best_tac;
  5491 
  5492 * LaTeX document preparation: several changes of isabelle.sty (see
  5493 lib/texinputs);
  5494 
  5495 
  5496 *** Document preparation ***
  5497 
  5498 * formal comments (text blocks etc.) in new-style theories may now
  5499 contain antiquotations of thm/prop/term/typ/text to be presented
  5500 according to latex print mode; concrete syntax is like this:
  5501 @{term[show_types] "f(x) = a + x"};
  5502 
  5503 * isatool mkdir provides easy setup of Isabelle session directories,
  5504 including proper document sources;
  5505 
  5506 * generated LaTeX sources are now deleted after successful run
  5507 (isatool document -c); may retain a copy somewhere else via -D option
  5508 of isatool usedir;
  5509 
  5510 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5511 style files, achieving self-contained LaTeX sources and simplifying
  5512 LaTeX debugging;
  5513 
  5514 * old-style theories now produce (crude) LaTeX output as well;
  5515 
  5516 * browser info session directories are now self-contained (may be put
  5517 on WWW server seperately); improved graphs of nested sessions; removed
  5518 graph for 'all sessions';
  5519 
  5520 * several improvements in isabelle style files; \isabellestyle{it}
  5521 produces fake math mode output; \isamarkupheader is now \section by
  5522 default; see lib/texinputs/isabelle.sty etc.;
  5523 
  5524 
  5525 *** Isar ***
  5526 
  5527 * Isar/Pure: local results and corresponding term bindings are now
  5528 subject to Hindley-Milner polymorphism (similar to ML); this
  5529 accommodates incremental type-inference very nicely;
  5530 
  5531 * Isar/Pure: new derived language element 'obtain' supports
  5532 generalized existence reasoning;
  5533 
  5534 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5535 support accumulation of results, without applying any rules yet;
  5536 useful to collect intermediate results without explicit name
  5537 references, and for use with transitivity rules with more than 2
  5538 premises;
  5539 
  5540 * Isar/Pure: scalable support for case-analysis type proofs: new
  5541 'case' language element refers to local contexts symbolically, as
  5542 produced by certain proof methods; internally, case names are attached
  5543 to theorems as "tags";
  5544 
  5545 * Isar/Pure: theory command 'hide' removes declarations from
  5546 class/type/const name spaces;
  5547 
  5548 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5549 indicate potential overloading;
  5550 
  5551 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5552 
  5553 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5554 "{a,b,c}" instead of {a,b,c};
  5555 
  5556 * Isar/Pure now provides its own version of intro/elim/dest
  5557 attributes; useful for building new logics, but beware of confusion
  5558 with the version in Provers/classical;
  5559 
  5560 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5561 case name 'antecedent';
  5562 
  5563 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5564 to the current context is now done automatically);
  5565 
  5566 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5567 for definining proof methods in ML;
  5568 
  5569 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5570 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5571 most cases, one should have to change intro!! to intro? only);
  5572 replaced "delrule" by "rule del";
  5573 
  5574 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5575 'symmetric' attribute (the latter supercedes [RS sym]);
  5576 
  5577 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5578 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5579 well (including splits);
  5580 
  5581 * Isar/Provers: Simplifier and Classical methods now support all kind
  5582 of modifiers used in the past, including 'cong', 'iff', etc.
  5583 
  5584 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5585 of Simplifier and Classical reasoner);
  5586 
  5587 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5588 now support named cases; major packages (inductive, datatype, primrec,
  5589 recdef) support case names and properly name parameters;
  5590 
  5591 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5592 monotonicity conditions are extracted to be proven at end of
  5593 calculations;
  5594 
  5595 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5596 method anyway;
  5597 
  5598 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5599 split_if split_if_asm; datatype package provides theorems foo.splits =
  5600 foo.split foo.split_asm for each datatype;
  5601 
  5602 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5603 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5604 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5605 use "(cases (simplified))" method in proper proof texts);
  5606 
  5607 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5608 
  5609 * Isar: names of theorems etc. may be natural numbers as well;
  5610 
  5611 * Isar: 'pr' command: optional arguments for goals_limit and
  5612 ProofContext.prems_limit; no longer prints theory contexts, but only
  5613 proof states;
  5614 
  5615 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5616 additional print modes to be specified; e.g. "pr(latex)" will print
  5617 proof state according to the Isabelle LaTeX style;
  5618 
  5619 * Isar: improved support for emulating tactic scripts, including proof
  5620 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5621 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5622 (for HOL datatypes);
  5623 
  5624 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5625 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5626 'proof method scripts' have to be in depth-first order;
  5627 
  5628 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5629 
  5630 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5631 should instead use individual commands for printing items
  5632 (print_commands, print_methods etc.);
  5633 
  5634 * Isar: added 'nothing' --- the empty list of theorems;
  5635 
  5636 
  5637 *** HOL ***
  5638 
  5639 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5640 corresponding virtual machine and a specification of its bytecode
  5641 verifier and a lightweight bytecode verifier, including proofs of
  5642 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5643 Cornelia Pusch (see also the homepage of project Bali at
  5644 http://isabelle.in.tum.de/Bali/);
  5645 
  5646 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5647 Clemens Ballarin;
  5648 
  5649 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5650 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5651 Rasmussen;
  5652 
  5653 * HOL/Lattice: fundamental concepts of lattice theory and order
  5654 structures, including duals, properties of bounds versus algebraic
  5655 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5656 Theorem for complete lattices etc.; may also serve as a demonstration
  5657 for abstract algebraic reasoning using axiomatic type classes, and
  5658 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5659 
  5660 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5661 von Oheimb;
  5662 
  5663 * HOL/IMPP: extension of IMP with local variables and mutually
  5664 recursive procedures, by David von Oheimb;
  5665 
  5666 * HOL/Lambda: converted into new-style theory and document;
  5667 
  5668 * HOL/ex/Multiquote: example of multiple nested quotations and
  5669 anti-quotations -- basically a generalized version of de-Bruijn
  5670 representation; very useful in avoiding lifting of operations;
  5671 
  5672 * HOL/record: added general record equality rule to simpset; fixed
  5673 select-update simplification procedure to handle extended records as
  5674 well; admit "r" as field name;
  5675 
  5676 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5677 other numeric types and also as the identity of groups, rings, etc.;
  5678 
  5679 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5680 Types nat and int belong to this axclass;
  5681 
  5682 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5683    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5684    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5685   two terms #m*u and #n*u are replaced by #(m+n)*u
  5686     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5687   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5688     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5689 
  5690 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5691 powerful prover for predicate logic but knows nothing of clasets; see
  5692 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5693 
  5694 * HOL: new version of "case_tac" subsumes both boolean case split and
  5695 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5696 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5697 
  5698 * HOL: simplification no longer dives into case-expressions: only the
  5699 selector expression is simplified, but not the remaining arms; to
  5700 enable full simplification of case-expressions for datatype t, you may
  5701 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5702 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5703 
  5704 * HOL/recdef: the recursion equations generated by 'recdef' for
  5705 function 'f' are now called f.simps instead of f.rules; if all
  5706 termination conditions are proved automatically, these simplification
  5707 rules are added to the simpset, as in primrec; rules may be named
  5708 individually as well, resulting in a separate list of theorems for
  5709 each equation;
  5710 
  5711 * HOL/While is a new theory that provides a while-combinator. It
  5712 permits the definition of tail-recursive functions without the
  5713 provision of a termination measure. The latter is necessary once the
  5714 invariant proof rule for while is applied.
  5715 
  5716 * HOL: new (overloaded) notation for the set of elements below/above
  5717 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5718 
  5719 * HOL: theorems impI, allI, ballI bound as "strip";
  5720 
  5721 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5722 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5723 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5724 
  5725 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5726 
  5727 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5728 main HOL, but was unused);
  5729 
  5730 * HOL: fewer consts declared as global (e.g. have to refer to
  5731 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5732 
  5733 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5734 in case of overlap with user translations (e.g. judgements over
  5735 tuples); (note that the underlying logical represenation is still
  5736 bogus);
  5737 
  5738 
  5739 *** ZF ***
  5740 
  5741 * ZF: simplification automatically cancels common terms in arithmetic
  5742 expressions over nat and int;
  5743 
  5744 * ZF: new treatment of nat to minimize type-checking: all operators
  5745 coerce their operands to a natural number using the function natify,
  5746 making the algebraic laws unconditional;
  5747 
  5748 * ZF: as above, for int: operators coerce their operands to an integer
  5749 using the function intify;
  5750 
  5751 * ZF: the integer library now contains many of the usual laws for the
  5752 orderings, including $<=, and monotonicity laws for $+ and $*;
  5753 
  5754 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5755 simplification;
  5756 
  5757 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5758 to the simplifier and classical reasoner simultaneously;
  5759 
  5760 
  5761 *** General ***
  5762 
  5763 * Provers: blast_tac now handles actual object-logic rules as
  5764 assumptions; note that auto_tac uses blast_tac internally as well;
  5765 
  5766 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5767 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5768 
  5769 * Provers: delrules now handles destruct rules as well (no longer need
  5770 explicit make_elim);
  5771 
  5772 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5773   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5774 use instead the strong form,
  5775   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5776 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5777 from destruct-rules;
  5778 
  5779 * Provers: Simplifier.easy_setup provides a fast path to basic
  5780 Simplifier setup for new object-logics;
  5781 
  5782 * Pure: AST translation rules no longer require constant head on LHS;
  5783 
  5784 * Pure: improved name spaces: ambiguous output is qualified; support
  5785 for hiding of names;
  5786 
  5787 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5788 XSYMBOL_HOME; no longer need to do manual configuration in most
  5789 situations;
  5790 
  5791 * system: compression of ML heaps images may now be controlled via -c
  5792 option of isabelle and isatool usedir (currently only observed by
  5793 Poly/ML);
  5794 
  5795 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5796 useful for remote X11);
  5797 
  5798 * system: provide TAGS file for Isabelle sources;
  5799 
  5800 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5801 order;
  5802 
  5803 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5804 timing flag supersedes proof_timing and Toplevel.trace;
  5805 
  5806 * ML: new combinators |>> and |>>> for incremental transformations
  5807 with secondary results (e.g. certain theory extensions):
  5808 
  5809 * ML: PureThy.add_defs gets additional argument to indicate potential
  5810 overloading (usually false);
  5811 
  5812 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5813 results;
  5814 
  5815 
  5816 
  5817 New in Isabelle99 (October 1999)
  5818 --------------------------------
  5819 
  5820 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5821 
  5822 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5823 are no longer simplified.  (This allows the simplifier to unfold recursive
  5824 functional programs.)  To restore the old behaviour, declare
  5825 
  5826     Delcongs [if_weak_cong];
  5827 
  5828 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5829 complement;
  5830 
  5831 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5832 
  5833 * HOL/datatype: mutual_induct_tac no longer exists --
  5834   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5835 
  5836 * HOL/typedef: fixed type inference for representing set; type
  5837 arguments now have to occur explicitly on the rhs as type constraints;
  5838 
  5839 * ZF: The con_defs part of an inductive definition may no longer refer
  5840 to constants declared in the same theory;
  5841 
  5842 * HOL, ZF: the function mk_cases, generated by the inductive
  5843 definition package, has lost an argument.  To simplify its result, it
  5844 uses the default simpset instead of a supplied list of theorems.
  5845 
  5846 * HOL/List: the constructors of type list are now Nil and Cons;
  5847 
  5848 * Simplifier: the type of the infix ML functions
  5849         setSSolver addSSolver setSolver addSolver
  5850 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5851 for packaging solvers. A solver is created via
  5852         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5853 where the string argument is only a comment.
  5854 
  5855 
  5856 *** Proof tools ***
  5857 
  5858 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5859 decision procedure for linear arithmetic. Currently it is used for
  5860 types `nat', `int', and `real' in HOL (see below); it can, should and
  5861 will be instantiated for other types and logics as well.
  5862 
  5863 * The simplifier now accepts rewrite rules with flexible heads, eg
  5864      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5865   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5866   matching.
  5867 
  5868 
  5869 *** General ***
  5870 
  5871 * New Isabelle/Isar subsystem provides an alternative to traditional
  5872 tactical theorem proving; together with the ProofGeneral/isar user
  5873 interface it offers an interactive environment for developing human
  5874 readable proof documents (Isar == Intelligible semi-automated
  5875 reasoning); for further information see isatool doc isar-ref,
  5876 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5877 
  5878 * improved and simplified presentation of theories: better HTML markup
  5879 (including colors), graph views in several sizes; isatool usedir now
  5880 provides a proper interface for user theories (via -P option); actual
  5881 document preparation based on (PDF)LaTeX is available as well (for
  5882 new-style theories only); see isatool doc system for more information;
  5883 
  5884 * native support for Proof General, both for classic Isabelle and
  5885 Isabelle/Isar;
  5886 
  5887 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5888 using the graph browser tool;
  5889 
  5890 * Isabelle manuals now also available as PDF;
  5891 
  5892 * theory loader rewritten from scratch (may not be fully
  5893 bug-compatible); old loadpath variable has been replaced by show_path,
  5894 add_path, del_path, reset_path functions; new operations such as
  5895 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5896 isatool doc ref);
  5897 
  5898 * improved isatool install: option -k creates KDE application icon,
  5899 option -p DIR installs standalone binaries;
  5900 
  5901 * added ML_PLATFORM setting (useful for cross-platform installations);
  5902 more robust handling of platform specific ML images for SML/NJ;
  5903 
  5904 * the settings environment is now statically scoped, i.e. it is never
  5905 created again in sub-processes invoked from isabelle, isatool, or
  5906 Isabelle;
  5907 
  5908 * path element specification '~~' refers to '$ISABELLE_HOME';
  5909 
  5910 * in locales, the "assumes" and "defines" parts may be omitted if
  5911 empty;
  5912 
  5913 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5914 long arrows);
  5915 
  5916 * new print_mode "HTML";
  5917 
  5918 * new flag show_tags controls display of tags of theorems (which are
  5919 basically just comments that may be attached by some tools);
  5920 
  5921 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5922 mode and goal output format:
  5923 
  5924 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5925 244c244
  5926 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5927 ---
  5928 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5929 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5930 181c181
  5931 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5932 ---
  5933 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5934 
  5935 * function bind_thms stores lists of theorems (cf. bind_thm);
  5936 
  5937 * new shorthand tactics ftac, eatac, datac, fatac;
  5938 
  5939 * qed (and friends) now accept "" as result name; in that case the
  5940 theorem is not stored, but proper checks and presentation of the
  5941 result still apply;
  5942 
  5943 * theorem database now also indexes constants "Trueprop", "all",
  5944 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5945 
  5946 
  5947 *** HOL ***
  5948 
  5949 ** HOL arithmetic **
  5950 
  5951 * There are now decision procedures for linear arithmetic over nat and
  5952 int:
  5953 
  5954 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5955 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5956 are treated as atomic; subformulae not involving type `nat' or `int'
  5957 are ignored; quantified subformulae are ignored unless they are
  5958 positive universal or negative existential. The tactic has to be
  5959 invoked by hand and can be a little bit slow. In particular, the
  5960 running time is exponential in the number of occurrences of `min' and
  5961 `max', and `-' on `nat'.
  5962 
  5963 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5964 (negated) (in)equalities among the premises and the conclusion into
  5965 account (i.e. no compound formulae) and does not know about `min' and
  5966 `max', and `-' on `nat'. It is fast and is used automatically by the
  5967 simplifier.
  5968 
  5969 NB: At the moment, these decision procedures do not cope with mixed
  5970 nat/int formulae where the two parts interact, such as `m < n ==>
  5971 int(m) < int(n)'.
  5972 
  5973 * HOL/Numeral provides a generic theory of numerals (encoded
  5974 efficiently as bit strings); setup for types nat/int/real is in place;
  5975 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5976 int, existing theories and proof scripts may require a few additional
  5977 type constraints;
  5978 
  5979 * integer division and remainder can now be performed on constant
  5980 arguments;
  5981 
  5982 * many properties of integer multiplication, division and remainder
  5983 are now available;
  5984 
  5985 * An interface to the Stanford Validity Checker (SVC) is available through the
  5986 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5987 are proved automatically.  SVC must be installed separately, and its results
  5988 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5989 invocation of the underlying oracle).  For SVC see
  5990   http://verify.stanford.edu/SVC
  5991 
  5992 * IsaMakefile: the HOL-Real target now builds an actual image;
  5993 
  5994 
  5995 ** HOL misc **
  5996 
  5997 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5998 (in Isabelle/Isar) -- by Gertrud Bauer;
  5999 
  6000 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  6001 analysis for assembly languages with subtypes;
  6002 
  6003 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  6004 -- avoids syntactic ambiguities and treats state, transition, and
  6005 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  6006 changed syntax and (many) tactics;
  6007 
  6008 * HOL/inductive: Now also handles more general introduction rules such
  6009   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  6010   theorems are now maintained within the theory (maintained via the
  6011   "mono" attribute);
  6012 
  6013 * HOL/datatype: Now also handles arbitrarily branching datatypes
  6014   (using function types) such as
  6015 
  6016   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  6017 
  6018 * HOL/record: record_simproc (part of the default simpset) takes care
  6019 of selectors applied to updated records; record_split_tac is no longer
  6020 part of the default claset; update_defs may now be removed from the
  6021 simpset in many cases; COMPATIBILITY: old behavior achieved by
  6022 
  6023   claset_ref () := claset() addSWrapper record_split_wrapper;
  6024   Delsimprocs [record_simproc]
  6025 
  6026 * HOL/typedef: fixed type inference for representing set; type
  6027 arguments now have to occur explicitly on the rhs as type constraints;
  6028 
  6029 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  6030 names rather than an ML expression;
  6031 
  6032 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  6033 supplied later.  Program schemes can be defined, such as
  6034     "While B C s = (if B s then While B C (C s) else s)"
  6035 where the well-founded relation can be chosen after B and C have been given.
  6036 
  6037 * HOL/List: the constructors of type list are now Nil and Cons;
  6038 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  6039 course, ML tools referring to List.list.op # etc. have to be adapted;
  6040 
  6041 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  6042 disabled by default; run isabelle with option -m HOL to get back to
  6043 the original Gordon/HOL-style output;
  6044 
  6045 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  6046 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  6047 
  6048 * HOL basic syntax simplified (more orthogonal): all variants of
  6049 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  6050 Eps operator is provided as well: "SOME x. P[x]";
  6051 
  6052 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  6053 
  6054 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  6055 thus available for user theories;
  6056 
  6057 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  6058 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  6059 time;
  6060 
  6061 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  6062 several times and then mp;
  6063 
  6064 
  6065 *** LK ***
  6066 
  6067 * the notation <<...>> is now available as a notation for sequences of
  6068 formulas;
  6069 
  6070 * the simplifier is now installed
  6071 
  6072 * the axiom system has been generalized (thanks to Soren Heilmann)
  6073 
  6074 * the classical reasoner now has a default rule database
  6075 
  6076 
  6077 *** ZF ***
  6078 
  6079 * new primrec section allows primitive recursive functions to be given
  6080 directly (as in HOL) over datatypes and the natural numbers;
  6081 
  6082 * new tactics induct_tac and exhaust_tac for induction (or case
  6083 analysis) over datatypes and the natural numbers;
  6084 
  6085 * the datatype declaration of type T now defines the recursor T_rec;
  6086 
  6087 * simplification automatically does freeness reasoning for datatype
  6088 constructors;
  6089 
  6090 * automatic type-inference, with AddTCs command to insert new
  6091 type-checking rules;
  6092 
  6093 * datatype introduction rules are now added as Safe Introduction rules
  6094 to the claset;
  6095 
  6096 * the syntax "if P then x else y" is now available in addition to
  6097 if(P,x,y);
  6098 
  6099 
  6100 *** Internal programming interfaces ***
  6101 
  6102 * tuned simplifier trace output; new flag debug_simp;
  6103 
  6104 * structures Vartab / Termtab (instances of TableFun) offer efficient
  6105 tables indexed by indexname_ord / term_ord (compatible with aconv);
  6106 
  6107 * AxClass.axclass_tac lost the theory argument;
  6108 
  6109 * tuned current_goals_markers semantics: begin / end goal avoids
  6110 printing empty lines;
  6111 
  6112 * removed prs and prs_fn hook, which was broken because it did not
  6113 include \n in its semantics, forcing writeln to add one
  6114 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  6115 string -> unit if you really want to output text without newline;
  6116 
  6117 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  6118 plain output, interface builders may have to enable 'isabelle_font'
  6119 mode to get Isabelle font glyphs as before;
  6120 
  6121 * refined token_translation interface; INCOMPATIBILITY: output length
  6122 now of type real instead of int;
  6123 
  6124 * theory loader actions may be traced via new ThyInfo.add_hook
  6125 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  6126 your own database of information attached to *whole* theories -- as
  6127 opposed to intra-theory data slots offered via TheoryDataFun;
  6128 
  6129 * proper handling of dangling sort hypotheses (at last!);
  6130 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  6131 extra sort hypotheses that can be witnessed from the type signature;
  6132 the force_strip_shyps flag is gone, any remaining shyps are simply
  6133 left in the theorem (with a warning issued by strip_shyps_warning);
  6134 
  6135 
  6136 
  6137 New in Isabelle98-1 (October 1998)
  6138 ----------------------------------
  6139 
  6140 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6141 
  6142 * several changes of automated proof tools;
  6143 
  6144 * HOL: major changes to the inductive and datatype packages, including
  6145 some minor incompatibilities of theory syntax;
  6146 
  6147 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  6148 called `inj_on';
  6149 
  6150 * HOL: removed duplicate thms in Arith:
  6151   less_imp_add_less  should be replaced by  trans_less_add1
  6152   le_imp_add_le      should be replaced by  trans_le_add1
  6153 
  6154 * HOL: unary minus is now overloaded (new type constraints may be
  6155 required);
  6156 
  6157 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  6158 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  6159 now taken as an integer constant.
  6160 
  6161 * Pure: ML function 'theory_of' renamed to 'theory';
  6162 
  6163 
  6164 *** Proof tools ***
  6165 
  6166 * Simplifier:
  6167   1. Asm_full_simp_tac is now more aggressive.
  6168      1. It will sometimes reorient premises if that increases their power to
  6169         simplify.
  6170      2. It does no longer proceed strictly from left to right but may also
  6171         rotate premises to achieve further simplification.
  6172      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  6173      old Asm_full_simp_tac in that it does not rotate premises.
  6174   2. The simplifier now knows a little bit about nat-arithmetic.
  6175 
  6176 * Classical reasoner: wrapper mechanism for the classical reasoner now
  6177 allows for selected deletion of wrappers, by introduction of names for
  6178 wrapper functionals.  This implies that addbefore, addSbefore,
  6179 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  6180 and that adding two tactics with the same name overwrites the first
  6181 one (emitting a warning).
  6182   type wrapper = (int -> tactic) -> (int -> tactic)
  6183   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  6184   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  6185   delWrapper, delSWrapper: claset *  string            -> claset
  6186   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  6187 
  6188 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  6189 semantics; addbefore now affects only the unsafe part of step_tac
  6190 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  6191 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  6192 by Force_tac;
  6193 
  6194 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  6195 compWrapper; added safe wrapper (and access functions for it);
  6196 
  6197 * HOL/split_all_tac is now much faster and fails if there is nothing
  6198 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  6199 and the names of the automatically generated variables have changed.
  6200 split_all_tac has moved within claset() from unsafe wrappers to safe
  6201 wrappers, which means that !!-bound variables are split much more
  6202 aggressively, and safe_tac and clarify_tac now split such variables.
  6203 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  6204 Note: the same holds for record_split_tac, which does the job of
  6205 split_all_tac for record fields.
  6206 
  6207 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  6208 permanently to the default simpset using Addsplits just like
  6209 Addsimps. They can be removed via Delsplits just like
  6210 Delsimps. Lower-case versions are also available.
  6211 
  6212 * HOL/Simplifier: The rule split_if is now part of the default
  6213 simpset. This means that the simplifier will eliminate all occurrences
  6214 of if-then-else in the conclusion of a goal. To prevent this, you can
  6215 either remove split_if completely from the default simpset by
  6216 `Delsplits [split_if]' or remove it in a specific call of the
  6217 simplifier using `... delsplits [split_if]'.  You can also add/delete
  6218 other case splitting rules to/from the default simpset: every datatype
  6219 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  6220 t is the name of the datatype).
  6221 
  6222 * Classical reasoner / Simplifier combination: new force_tac (and
  6223 derivatives Force_tac, force) combines rewriting and classical
  6224 reasoning (and whatever other tools) similarly to auto_tac, but is
  6225 aimed to solve the given subgoal completely.
  6226 
  6227 
  6228 *** General ***