NEWS
author wenzelm
Sun Apr 25 22:50:47 2010 +0200 (2010-04-25 ago)
changeset 36329 85004134055c
parent 36317 506d732cb522
child 36348 89c54f51f55a
permissions -rw-r--r--
more systematic treatment of data -- avoid slightly odd nested tuples here;
tuned;
     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 * Code generator: simple concept for abstract datatypes obeying invariants.
    88 
    89 * Local theory specifications may depend on extra type variables that
    90 are not present in the result type -- arguments TYPE('a) :: 'a itself
    91 are added internally.  For example:
    92 
    93   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
    94 
    95 * Code generator: details of internal data cache have no impact on
    96 the user space functionality any longer.
    97 
    98 * Methods unfold_locales and intro_locales ignore non-locale subgoals.  This
    99 is more appropriate for interpretations with 'where'.  INCOMPATIBILITY.
   100 
   101 * Discontinued unnamed infix syntax (legacy feature for many years) --
   102 need to specify constant name and syntax separately.  Internal ML
   103 datatype constructors have been renamed from InfixName to Infix etc.
   104 Minor INCOMPATIBILITY.
   105 
   106 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   107 within a local theory context, with explicit checking of the
   108 constructors involved (in contrast to the raw 'syntax' versions).
   109 
   110 * Commands 'types' and 'typedecl' now work within a local theory
   111 context -- without introducing dependencies on parameters or
   112 assumptions, which is not possible in Isabelle/Pure.
   113 
   114 * Proof terms: Type substitutions on proof constants now use canonical
   115 order of type variables. INCOMPATIBILITY: Tools working with proof
   116 terms may need to be adapted.
   117 
   118 
   119 *** HOL ***
   120 
   121 * Abstract algebra:
   122   * class division_by_zero includes division_ring;
   123   * numerous lemmas have been ported from field to division_ring;
   124   * dropped lemma eq_minus_self_iff which is a duplicate for equal_neg_zero.
   125 
   126   INCOMPATIBILITY.
   127 
   128 * Library theory 'RBT' renamed to 'RBT_Impl'; new library theory 'RBT'
   129 provides abstract red-black tree type which is backed by RBT_Impl
   130 as implementation.  INCOMPATIBILTY.
   131 
   132 * Command 'typedef' now works within a local theory context -- without
   133 introducing dependencies on parameters or assumptions, which is not
   134 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   135 contain multiple interpretations of local typedefs (with different
   136 non-emptiness proofs), even in a global theory context.
   137 
   138 * Theory Library/Coinductive_List has been removed -- superceded by
   139 AFP/thys/Coinductive.
   140 
   141 * Split off theory Big_Operators containing setsum, setprod, Inf_fin, Sup_fin,
   142 Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   143 
   144 * Theory "Rational" renamed to "Rat", for consistency with "Nat", "Int" etc.
   145 INCOMPATIBILITY.
   146 
   147 * New set of rules "ac_simps" provides combined assoc / commute rewrites
   148 for all interpretations of the appropriate generic locales.
   149 
   150 * Renamed theory "OrderedGroup" to "Groups" and split theory "Ring_and_Field"
   151 into theories "Rings" and "Fields";  for more appropriate and more
   152 consistent names suitable for name prefixes within the HOL theories.
   153 INCOMPATIBILITY.
   154 
   155 * Some generic constants have been put to appropriate theories:
   156 
   157     less_eq, less: Orderings
   158     zero, one, plus, minus, uminus, times, abs, sgn: Groups
   159     inverse, divide: Rings
   160 
   161 INCOMPATIBILITY.
   162 
   163 * Class division_ring also requires proof of fact divide_inverse.  However instantiation
   164 of parameter divide has also been required previously.  INCOMPATIBILITY.
   165 
   166 * More consistent naming of type classes involving orderings (and lattices):
   167 
   168     lower_semilattice                   ~> semilattice_inf
   169     upper_semilattice                   ~> semilattice_sup
   170 
   171     dense_linear_order                  ~> dense_linorder
   172 
   173     pordered_ab_group_add               ~> ordered_ab_group_add
   174     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   175     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   176     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   177     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   178     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   179     pordered_cancel_semiring            ~> ordered_cancel_semiring
   180     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   181     pordered_comm_ring                  ~> ordered_comm_ring
   182     pordered_comm_semiring              ~> ordered_comm_semiring
   183     pordered_ring                       ~> ordered_ring
   184     pordered_ring_abs                   ~> ordered_ring_abs
   185     pordered_semiring                   ~> ordered_semiring
   186 
   187     ordered_ab_group_add                ~> linordered_ab_group_add
   188     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   189     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   190     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   191     ordered_field                       ~> linordered_field
   192     ordered_field_no_lb                 ~> linordered_field_no_lb
   193     ordered_field_no_ub                 ~> linordered_field_no_ub
   194     ordered_field_dense_linear_order    ~> dense_linordered_field
   195     ordered_idom                        ~> linordered_idom
   196     ordered_ring                        ~> linordered_ring
   197     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   198     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   199     ordered_ring_strict                 ~> linordered_ring_strict
   200     ordered_semidom                     ~> linordered_semidom
   201     ordered_semiring                    ~> linordered_semiring
   202     ordered_semiring_1                  ~> linordered_semiring_1
   203     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   204     ordered_semiring_strict             ~> linordered_semiring_strict
   205 
   206   The following slightly odd type classes have been moved to
   207   a separate theory Library/Lattice_Algebras.thy:
   208 
   209     lordered_ab_group_add               ~> lattice_ab_group_add
   210     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   211     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   212     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   213     lordered_ring                       ~> lattice_ring
   214 
   215 INCOMPATIBILITY.
   216 
   217 * HOLogic.strip_psplit: types are returned in syntactic order, similar
   218 to other strip and tuple operations.  INCOMPATIBILITY.
   219 
   220 * Various old-style primrec specifications in the HOL theories have been
   221 replaced by new-style primrec, especially in theory List.  The corresponding
   222 constants now have authentic syntax.  INCOMPATIBILITY.
   223 
   224 * Reorganized theory Multiset: swapped notation of pointwise and multiset order:
   225   * pointwise ordering is instance of class order with standard syntax <= and <;
   226   * multiset ordering has syntax <=# and <#; partial order properties are provided
   227       by means of interpretation with prefix multiset_order.
   228 Less duplication, less historical organization of sections,
   229 conversion from associations lists to multisets, rudimentary code generation.
   230 Use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union, if needed.
   231 INCOMPATIBILITY.
   232 
   233 * Reorganized theory Sum_Type; Inl and Inr now have authentic syntax.
   234 INCOMPATIBILITY.
   235 
   236 * Code generation: ML and OCaml code is decorated with signatures.
   237 
   238 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   239 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   240 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   241 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   242 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   243 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   244 
   245 * Theory Finite_Set and List: some lemmas have been generalized from
   246 sets to lattices:
   247 
   248   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   249   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   250   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   251   union_Union_fold_union        ~> sup_Sup_fold_sup
   252   Inter_fold_inter              ~> Inf_fold_inf
   253   Union_fold_union              ~> Sup_fold_sup
   254   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   255   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   256   INTER_fold_inter              ~> INFI_fold_inf
   257   UNION_fold_union              ~> SUPR_fold_sup
   258 
   259 * Theory List: added transpose.
   260 
   261 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   262 clash with new theory Quotient in Main HOL.
   263 
   264 * Library/Nat_Bijection.thy is a collection of bijective functions
   265 between nat and other types, which supersedes the older libraries
   266 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   267 
   268   Constants:
   269   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   270   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   271   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   272   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   273   Countable.pair_encode           ~> prod_encode
   274   NatIso.prod2nat                 ~> prod_encode
   275   NatIso.nat2prod                 ~> prod_decode
   276   NatIso.sum2nat                  ~> sum_encode
   277   NatIso.nat2sum                  ~> sum_decode
   278   NatIso.list2nat                 ~> list_encode
   279   NatIso.nat2list                 ~> list_decode
   280   NatIso.set2nat                  ~> set_encode
   281   NatIso.nat2set                  ~> set_decode
   282 
   283   Lemmas:
   284   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   285   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   286   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   287   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   288   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   289   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   290   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   291   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   292   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   293   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   294   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   295   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   296   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   297 
   298 
   299 *** ML ***
   300 
   301 * Antiquotations for basic formal entities:
   302 
   303     @{class NAME}         -- type class
   304     @{class_syntax NAME}  -- syntax representation of the above
   305 
   306     @{type_name NAME}     -- logical type
   307     @{type_abbrev NAME}   -- type abbreviation
   308     @{nonterminal NAME}   -- type of concrete syntactic category
   309     @{type_syntax NAME}   -- syntax representation of any of the above
   310 
   311     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   312     @{const_abbrev NAME}  -- abbreviated constant
   313     @{const_syntax NAME}  -- syntax representation of any of the above
   314 
   315 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   316 syntax constant (cf. 'syntax' command).
   317 
   318 * Antiquotation @{make_string} inlines a function to print arbitrary
   319 values similar to the ML toplevel.  The result is compiler dependent
   320 and may fall back on "?" in certain situations.
   321 
   322 * Renamed old-style Drule.standard to Drule.export_without_context, to
   323 emphasize that this is in no way a standard operation.
   324 INCOMPATIBILITY.
   325 
   326 * Curried take and drop in library.ML; negative length is interpreted
   327 as infinity (as in chop).  INCOMPATIBILITY.
   328 
   329 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   330 usual for resolution.  Rare INCOMPATIBILITY.
   331 
   332 * Discontinued old TheoryDataFun with its copy/init operation -- data
   333 needs to be pure.  Functor Theory_Data_PP retains the traditional
   334 Pretty.pp argument to merge, which is absent in the standard
   335 Theory_Data version.
   336 
   337 * Renamed varify/unvarify operations to varify_global/unvarify_global
   338 to emphasize that these only work in a global situation (which is
   339 quite rare).
   340 
   341 * Configuration options now admit dynamic default values, depending on
   342 the context or even global references.
   343 
   344 
   345 *** System ***
   346 
   347 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   348 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   349 proof terms are enabled unconditionally in the new HOL-Proofs image.
   350 
   351 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   352 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   353 respectively.
   354 
   355 * Old lib/scripts/polyml-platform is superseded by the
   356 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   357 variant, even on a 64 bit machine.  The following example setting
   358 prefers 64 bit if available:
   359 
   360   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   361 
   362 
   363 
   364 New in Isabelle2009-1 (December 2009)
   365 -------------------------------------
   366 
   367 *** General ***
   368 
   369 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   370 one backslash should be used, even in ML sources.
   371 
   372 
   373 *** Pure ***
   374 
   375 * Locale interpretation propagates mixins along the locale hierarchy.
   376 The currently only available mixins are the equations used to map
   377 local definitions to terms of the target domain of an interpretation.
   378 
   379 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   380 loc" to print all interpretations of locale "loc" in the theory.
   381 Interpretations in proofs are not shown.
   382 
   383 * Thoroughly revised locales tutorial.  New section on conditional
   384 interpretation.
   385 
   386 * On instantiation of classes, remaining undefined class parameters
   387 are formally declared.  INCOMPATIBILITY.
   388 
   389 
   390 *** Document preparation ***
   391 
   392 * New generalized style concept for printing terms: @{foo (style) ...}
   393 instead of @{foo_style style ...}  (old form is still retained for
   394 backward compatibility).  Styles can be also applied for
   395 antiquotations prop, term_type and typeof.
   396 
   397 
   398 *** HOL ***
   399 
   400 * New proof method "smt" for a combination of first-order logic with
   401 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   402 fixed-size bitvectors; there is also basic support for higher-order
   403 features (esp. lambda abstractions).  It is an incomplete decision
   404 procedure based on external SMT solvers using the oracle mechanism;
   405 for the SMT solver Z3, this method is proof-producing.  Certificates
   406 are provided to avoid calling the external solvers solely for
   407 re-checking proofs.  Due to a remote SMT service there is no need for
   408 installing SMT solvers locally.  See src/HOL/SMT.
   409 
   410 * New commands to load and prove verification conditions generated by
   411 the Boogie program verifier or derived systems (e.g. the Verifying C
   412 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   413 
   414 * New counterexample generator tool 'nitpick' based on the Kodkod
   415 relational model finder.  See src/HOL/Tools/Nitpick and
   416 src/HOL/Nitpick_Examples.
   417 
   418 * New commands 'code_pred' and 'values' to invoke the predicate
   419 compiler and to enumerate values of inductive predicates.
   420 
   421 * A tabled implementation of the reflexive transitive closure.
   422 
   423 * New implementation of quickcheck uses generic code generator;
   424 default generators are provided for all suitable HOL types, records
   425 and datatypes.  Old quickcheck can be re-activated importing theory
   426 Library/SML_Quickcheck.
   427 
   428 * New testing tool Mirabelle for automated proof tools.  Applies
   429 several tools and tactics like sledgehammer, metis, or quickcheck, to
   430 every proof step in a theory.  To be used in batch mode via the
   431 "mirabelle" utility.
   432 
   433 * New proof method "sos" (sum of squares) for nonlinear real
   434 arithmetic (originally due to John Harison). It requires theory
   435 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   436 works well in practice on quantifier-free real arithmetic with +, -,
   437 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   438 inequalities between polynomials.  It makes use of external
   439 semidefinite programming solvers.  Method "sos" generates a
   440 certificate that can be pasted into the proof thus avoiding the need
   441 to call an external tool every time the proof is checked.  See
   442 src/HOL/Library/Sum_Of_Squares.
   443 
   444 * New method "linarith" invokes existing linear arithmetic decision
   445 procedure only.
   446 
   447 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   448 
   449 * New Sledgehammer option "Full Types" in Proof General settings menu.
   450 Causes full type information to be output to the ATPs.  This slows
   451 ATPs down considerably but eliminates a source of unsound "proofs"
   452 that fail later.
   453 
   454 * New method "metisFT": A version of metis that uses full type
   455 information in order to avoid failures of proof reconstruction.
   456 
   457 * New evaluator "approximate" approximates an real valued term using
   458 the same method as the approximation method.
   459 
   460 * Method "approximate" now supports arithmetic expressions as
   461 boundaries of intervals and implements interval splitting and Taylor
   462 series expansion.
   463 
   464 * ML antiquotation @{code_datatype} inserts definition of a datatype
   465 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   466 
   467 * New theory SupInf of the supremum and infimum operators for sets of
   468 reals.
   469 
   470 * New theory Probability, which contains a development of measure
   471 theory, eventually leading to Lebesgue integration and probability.
   472 
   473 * Extended Multivariate Analysis to include derivation and Brouwer's
   474 fixpoint theorem.
   475 
   476 * Reorganization of number theory, INCOMPATIBILITY:
   477   - new number theory development for nat and int, in theories Divides
   478     and GCD as well as in new session Number_Theory
   479   - some constants and facts now suffixed with _nat and _int
   480     accordingly
   481   - former session NumberTheory now named Old_Number_Theory, including
   482     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   483   - moved theory Pocklington from src/HOL/Library to
   484     src/HOL/Old_Number_Theory
   485 
   486 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   487 lcm of finite and infinite sets. It is shown that they form a complete
   488 lattice.
   489 
   490 * Class semiring_div requires superclass no_zero_divisors and proof of
   491 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   492 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   493 generalized to class semiring_div, subsuming former theorems
   494 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   495 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   496 INCOMPATIBILITY.
   497 
   498 * Refinements to lattice classes and sets:
   499   - less default intro/elim rules in locale variant, more default
   500     intro/elim rules in class variant: more uniformity
   501   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   502     le_inf_iff
   503   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   504     sup_aci)
   505   - renamed ACI to inf_sup_aci
   506   - new class "boolean_algebra"
   507   - class "complete_lattice" moved to separate theory
   508     "Complete_Lattice"; corresponding constants (and abbreviations)
   509     renamed and with authentic syntax:
   510     Set.Inf ~>    Complete_Lattice.Inf
   511     Set.Sup ~>    Complete_Lattice.Sup
   512     Set.INFI ~>   Complete_Lattice.INFI
   513     Set.SUPR ~>   Complete_Lattice.SUPR
   514     Set.Inter ~>  Complete_Lattice.Inter
   515     Set.Union ~>  Complete_Lattice.Union
   516     Set.INTER ~>  Complete_Lattice.INTER
   517     Set.UNION ~>  Complete_Lattice.UNION
   518   - authentic syntax for
   519     Set.Pow
   520     Set.image
   521   - mere abbreviations:
   522     Set.empty               (for bot)
   523     Set.UNIV                (for top)
   524     Set.inter               (for inf, formerly Set.Int)
   525     Set.union               (for sup, formerly Set.Un)
   526     Complete_Lattice.Inter  (for Inf)
   527     Complete_Lattice.Union  (for Sup)
   528     Complete_Lattice.INTER  (for INFI)
   529     Complete_Lattice.UNION  (for SUPR)
   530   - object-logic definitions as far as appropriate
   531 
   532 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   533 Un_subset_iff are explicitly deleted as default simp rules; then also
   534 their lattice counterparts le_inf_iff and le_sup_iff have to be
   535 deleted to achieve the desired effect.
   536 
   537 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   538 rules by default any longer; the same applies to min_max.inf_absorb1
   539 etc.  INCOMPATIBILITY.
   540 
   541 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   542 pred_set_conv by default.  INCOMPATIBILITY.
   543 
   544 * Power operations on relations and functions are now one dedicated
   545 constant "compow" with infix syntax "^^".  Power operation on
   546 multiplicative monoids retains syntax "^" and is now defined generic
   547 in class power.  INCOMPATIBILITY.
   548 
   549 * Relation composition "R O S" now has a more standard argument order:
   550 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   551 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   552 break, since the O_assoc rule was not rewritten like this.  Fix using
   553 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   554 
   555 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   556 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   557 INCOMPATIBILITY.
   558 
   559 * Most rules produced by inductive and datatype package have mandatory
   560 prefixes.  INCOMPATIBILITY.
   561 
   562 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   563 the attribute of the same name.  Each of the theorems in the list
   564 DERIV_intros assumes composition with an additional function and
   565 matches a variable to the derivative, which has to be solved by the
   566 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   567 of most elementary terms.  Former Maclauren.DERIV_tac and
   568 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   569 INCOMPATIBILITY.
   570 
   571 * Code generator attributes follow the usual underscore convention:
   572     code_unfold     replaces    code unfold
   573     code_post       replaces    code post
   574     etc.
   575   INCOMPATIBILITY.
   576 
   577 * Renamed methods:
   578     sizechange -> size_change
   579     induct_scheme -> induction_schema
   580   INCOMPATIBILITY.
   581 
   582 * Discontinued abbreviation "arbitrary" of constant "undefined".
   583 INCOMPATIBILITY, use "undefined" directly.
   584 
   585 * Renamed theorems:
   586     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   587     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   588     Suc_plus1 -> Suc_eq_plus1
   589     *anti_sym -> *antisym*
   590     vector_less_eq_def -> vector_le_def
   591   INCOMPATIBILITY.
   592 
   593 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   594 INCOMPATIBILITY.
   595 
   596 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   597 INCOMPATIBILITY.
   598 
   599 
   600 *** HOLCF ***
   601 
   602 * Theory Representable defines a class "rep" of domains that are
   603 representable (via an ep-pair) in the universal domain type "udom".
   604 Instances are provided for all type constructors defined in HOLCF.
   605 
   606 * The 'new_domain' command is a purely definitional version of the
   607 domain package, for representable domains.  Syntax is identical to the
   608 old domain package.  The 'new_domain' package also supports indirect
   609 recursion using previously-defined type constructors.  See
   610 src/HOLCF/ex/New_Domain.thy for examples.
   611 
   612 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   613 on the left-hand side of an equation, and then performs
   614 simplification.  Rewriting is done using rules declared with the
   615 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   616 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   617 
   618 * The pattern-match compiler in 'fixrec' can now handle constructors
   619 with HOL function types.  Pattern-match combinators for the Pair
   620 constructor are pre-configured.
   621 
   622 * The 'fixrec' package now produces better fixed-point induction rules
   623 for mutually-recursive definitions:  Induction rules have conclusions
   624 of the form "P foo bar" instead of "P <foo, bar>".
   625 
   626 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   627 been renamed to "below".  The name "below" now replaces "less" in many
   628 theorem names.  (Legacy theorem names using "less" are still supported
   629 as well.)
   630 
   631 * The 'fixrec' package now supports "bottom patterns".  Bottom
   632 patterns can be used to generate strictness rules, or to make
   633 functions more strict (much like the bang-patterns supported by the
   634 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   635 examples.
   636 
   637 
   638 *** ML ***
   639 
   640 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   641 errors and run-time exceptions, including detailed source positions.
   642 
   643 * Structure Name_Space (formerly NameSpace) now manages uniquely
   644 identified entries, with some additional information such as source
   645 position, logical grouping etc.
   646 
   647 * Theory and context data is now introduced by the simplified and
   648 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   649 to be pure, but the old TheoryDataFun for mutable data (with explicit
   650 copy operation) is still available for some time.
   651 
   652 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   653 provides a high-level programming interface to synchronized state
   654 variables with atomic update.  This works via pure function
   655 application within a critical section -- its runtime should be as
   656 short as possible; beware of deadlocks if critical code is nested,
   657 either directly or indirectly via other synchronized variables!
   658 
   659 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   660 wraps raw ML references, explicitly indicating their non-thread-safe
   661 behaviour.  The Isar toplevel keeps this structure open, to
   662 accommodate Proof General as well as quick and dirty interactive
   663 experiments with references.
   664 
   665 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   666 parallel tactical reasoning.
   667 
   668 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   669 are similar to SUBPROOF, but are slightly more flexible: only the
   670 specified parts of the subgoal are imported into the context, and the
   671 body tactic may introduce new subgoals and schematic variables.
   672 
   673 * Old tactical METAHYPS, which does not observe the proof context, has
   674 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   675 or Subgoal.FOCUS etc.
   676 
   677 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   678 functors have their own ML name space there is no point to mark them
   679 separately.)  Minor INCOMPATIBILITY.
   680 
   681 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   682 
   683 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   684 INCOMPATIBILITY.
   685 
   686 * Operations of structure Skip_Proof no longer require quick_and_dirty
   687 mode, which avoids critical setmp.
   688 
   689 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   690 combinators for "args".  INCOMPATIBILITY, need to use simplified
   691 Attrib/Method.setup introduced in Isabelle2009.
   692 
   693 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   694 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   695 last resort.  INCOMPATIBILITY.
   696 
   697 * Display.pretty_thm now requires a proper context (cf. former
   698 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   699 or even Display.pretty_thm_without_context as last resort.
   700 INCOMPATIBILITY.
   701 
   702 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   703 Syntax.pretty_typ/term directly, preferably with proper context
   704 instead of global theory.
   705 
   706 
   707 *** System ***
   708 
   709 * Further fine tuning of parallel proof checking, scales up to 8 cores
   710 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   711 usedir option -q.
   712 
   713 * Support for additional "Isabelle components" via etc/components, see
   714 also the system manual.
   715 
   716 * The isabelle makeall tool now operates on all components with
   717 IsaMakefile, not just hardwired "logics".
   718 
   719 * Removed "compress" option from isabelle-process and isabelle usedir;
   720 this is always enabled.
   721 
   722 * Discontinued support for Poly/ML 4.x versions.
   723 
   724 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   725 on a given logic image.  This requires the lighttpd webserver and is
   726 currently supported on Linux only.
   727 
   728 
   729 
   730 New in Isabelle2009 (April 2009)
   731 --------------------------------
   732 
   733 *** General ***
   734 
   735 * Simplified main Isabelle executables, with less surprises on
   736 case-insensitive file-systems (such as Mac OS).
   737 
   738   - The main Isabelle tool wrapper is now called "isabelle" instead of
   739     "isatool."
   740 
   741   - The former "isabelle" alias for "isabelle-process" has been
   742     removed (should rarely occur to regular users).
   743 
   744   - The former "isabelle-interface" and its alias "Isabelle" have been
   745     removed (interfaces are now regular Isabelle tools).
   746 
   747 Within scripts and make files, the Isabelle environment variables
   748 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   749 respectively.  (The latter are still available as legacy feature.)
   750 
   751 The old isabelle-interface wrapper could react in confusing ways if
   752 the interface was uninstalled or changed otherwise.  Individual
   753 interface tool configuration is now more explicit, see also the
   754 Isabelle system manual.  In particular, Proof General is now available
   755 via "isabelle emacs".
   756 
   757 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   758 purge installed copies of Isabelle executables and re-run "isabelle
   759 install -p ...", or use symlinks.
   760 
   761 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   762 old ~/isabelle, which was slightly non-standard and apt to cause
   763 surprises on case-insensitive file-systems (such as Mac OS).
   764 
   765 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   766 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   767 care is required when using older releases of Isabelle.  Note that
   768 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   769 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   770 
   771 * Proofs of fully specified statements are run in parallel on
   772 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   773 a regular 4-core machine, if the initial heap space is made reasonably
   774 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   775 
   776 * The main reference manuals ("isar-ref", "implementation", and
   777 "system") have been updated and extended.  Formally checked references
   778 as hyperlinks are now available uniformly.
   779 
   780 
   781 *** Pure ***
   782 
   783 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   784 respects.  The most important changes are listed below.  See the
   785 Tutorial on Locales ("locales" manual) for details.
   786 
   787 - In locale expressions, instantiation replaces renaming.  Parameters
   788 must be declared in a for clause.  To aid compatibility with previous
   789 parameter inheritance, in locale declarations, parameters that are not
   790 'touched' (instantiation position "_" or omitted) are implicitly added
   791 with their syntax at the beginning of the for clause.
   792 
   793 - Syntax from abbreviations and definitions in locales is available in
   794 locale expressions and context elements.  The latter is particularly
   795 useful in locale declarations.
   796 
   797 - More flexible mechanisms to qualify names generated by locale
   798 expressions.  Qualifiers (prefixes) may be specified in locale
   799 expressions, and can be marked as mandatory (syntax: "name!:") or
   800 optional (syntax "name?:").  The default depends for plain "name:"
   801 depends on the situation where a locale expression is used: in
   802 commands 'locale' and 'sublocale' prefixes are optional, in
   803 'interpretation' and 'interpret' prefixes are mandatory.  The old
   804 implicit qualifiers derived from the parameter names of a locale are
   805 no longer generated.
   806 
   807 - Command "sublocale l < e" replaces "interpretation l < e".  The
   808 instantiation clause in "interpretation" and "interpret" (square
   809 brackets) is no longer available.  Use locale expressions.
   810 
   811 - When converting proof scripts, mandatory qualifiers in
   812 'interpretation' and 'interpret' should be retained by default, even
   813 if this is an INCOMPATIBILITY compared to former behavior.  In the
   814 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   815 in locale expressions range over a single locale instance only.
   816 
   817 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   818 In existing theorem specifications replace the includes element by the
   819 respective context elements of the included locale, omitting those
   820 that are already present in the theorem specification.  Multiple
   821 assume elements of a locale should be replaced by a single one
   822 involving the locale predicate.  In the proof body, declarations (most
   823 notably theorems) may be regained by interpreting the respective
   824 locales in the proof context as required (command "interpret").
   825 
   826 If using "includes" in replacement of a target solely because the
   827 parameter types in the theorem are not as general as in the target,
   828 consider declaring a new locale with additional type constraints on
   829 the parameters (context element "constrains").
   830 
   831 - Discontinued "locale (open)".  INCOMPATIBILITY.
   832 
   833 - Locale interpretation commands no longer attempt to simplify goal.
   834 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   835 methods intro_locales and unfold_locales to clarify.
   836 
   837 - Locale interpretation commands no longer accept interpretation
   838 attributes.  INCOMPATIBILITY.
   839 
   840 * Class declaration: so-called "base sort" must not be given in import
   841 list any longer, but is inferred from the specification.  Particularly
   842 in HOL, write
   843 
   844     class foo = ...
   845 
   846 instead of
   847 
   848     class foo = type + ...
   849 
   850 * Class target: global versions of theorems stemming do not carry a
   851 parameter prefix any longer.  INCOMPATIBILITY.
   852 
   853 * Class 'instance' command no longer accepts attached definitions.
   854 INCOMPATIBILITY, use proper 'instantiation' target instead.
   855 
   856 * Recovered hiding of consts, which was accidentally broken in
   857 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   858 makes c inaccessible; consider using ``hide (open) const c'' instead.
   859 
   860 * Slightly more coherent Pure syntax, with updated documentation in
   861 isar-ref manual.  Removed locales meta_term_syntax and
   862 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   863 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   864 directly in regular applications.
   865 
   866 * There is a new syntactic category "float_const" for signed decimal
   867 fractions (e.g. 123.45 or -123.45).
   868 
   869 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   870 interface with 'setup' command instead.
   871 
   872 * Command 'local_setup' is similar to 'setup', but operates on a local
   873 theory context.
   874 
   875 * The 'axiomatization' command now only works within a global theory
   876 context.  INCOMPATIBILITY.
   877 
   878 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   879 hypotheses.  Sorts required in the course of reasoning need to be
   880 covered by the constraints in the initial statement, completed by the
   881 type instance information of the background theory.  Non-trivial sort
   882 hypotheses, which rarely occur in practice, may be specified via
   883 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   884 
   885   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   886 
   887 The result contains an implicit sort hypotheses as before --
   888 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   889 normalization.
   890 
   891 * Generalized Isar history, with support for linear undo, direct state
   892 addressing etc.
   893 
   894 * Changed defaults for unify configuration options:
   895 
   896   unify_trace_bound = 50 (formerly 25)
   897   unify_search_bound = 60 (formerly 30)
   898 
   899 * Different bookkeeping for code equations (INCOMPATIBILITY):
   900 
   901   a) On theory merge, the last set of code equations for a particular
   902      constant is taken (in accordance with the policy applied by other
   903      parts of the code generator framework).
   904 
   905   b) Code equations stemming from explicit declarations (e.g. code
   906      attribute) gain priority over default code equations stemming
   907      from definition, primrec, fun etc.
   908 
   909 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   910 
   911 * Unified theorem tables for both code generators.  Thus [code
   912 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   913 
   914 * Command 'find_consts' searches for constants based on type and name
   915 patterns, e.g.
   916 
   917     find_consts "_ => bool"
   918 
   919 By default, matching is against subtypes, but it may be restricted to
   920 the whole type.  Searching by name is possible.  Multiple queries are
   921 conjunctive and queries may be negated by prefixing them with a
   922 hyphen:
   923 
   924     find_consts strict: "_ => bool" name: "Int" -"int => int"
   925 
   926 * New 'find_theorems' criterion "solves" matches theorems that
   927 directly solve the current goal (modulo higher-order unification).
   928 
   929 * Auto solve feature for main theorem statements: whenever a new goal
   930 is stated, "find_theorems solves" is called; any theorems that could
   931 solve the lemma directly are listed as part of the goal state.
   932 Cf. associated options in Proof General Isabelle settings menu,
   933 enabled by default, with reasonable timeout for pathological cases of
   934 higher-order unification.
   935 
   936 
   937 *** Document preparation ***
   938 
   939 * Antiquotation @{lemma} now imitates a regular terminal proof,
   940 demanding keyword 'by' and supporting the full method expression
   941 syntax just like the Isar command 'by'.
   942 
   943 
   944 *** HOL ***
   945 
   946 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   947 points Main and Complex_Main remain as before.
   948 
   949 * Logic image HOL-Plain provides a minimal HOL with the most important
   950 tools available (inductive, datatype, primrec, ...).  This facilitates
   951 experimentation and tool development.  Note that user applications
   952 (and library theories) should never refer to anything below theory
   953 Main, as before.
   954 
   955 * Logic image HOL-Main stops at theory Main, and thus facilitates
   956 experimentation due to shorter build times.
   957 
   958 * Logic image HOL-NSA contains theories of nonstandard analysis which
   959 were previously part of former HOL-Complex.  Entry point Hyperreal
   960 remains valid, but theories formerly using Complex_Main should now use
   961 new entry point Hypercomplex.
   962 
   963 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   964 Posix processes.  Avoids potentially expensive forking of the ML
   965 process.  New thread-based implementation also works on non-Unix
   966 platforms (Cygwin).  Provers are no longer hardwired, but defined
   967 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   968 commands are covered in the isar-ref manual.
   969 
   970 * Wrapper scripts for remote SystemOnTPTP service allows to use
   971 sledgehammer without local ATP installation (Vampire etc.). Other
   972 provers may be included via suitable ML wrappers, see also
   973 src/HOL/ATP_Linkup.thy.
   974 
   975 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   976 menu.
   977 
   978 * The metis method no longer fails because the theorem is too trivial
   979 (contains the empty clause).
   980 
   981 * The metis method now fails in the usual manner, rather than raising
   982 an exception, if it determines that it cannot prove the theorem.
   983 
   984 * Method "coherent" implements a prover for coherent logic (see also
   985 src/Tools/coherent.ML).
   986 
   987 * Constants "undefined" and "default" replace "arbitrary".  Usually
   988 "undefined" is the right choice to replace "arbitrary", though
   989 logically there is no difference.  INCOMPATIBILITY.
   990 
   991 * Command "value" now integrates different evaluation mechanisms.  The
   992 result of the first successful evaluation mechanism is printed.  In
   993 square brackets a particular named evaluation mechanisms may be
   994 specified (currently, [SML], [code] or [nbe]).  See further
   995 src/HOL/ex/Eval_Examples.thy.
   996 
   997 * Normalization by evaluation now allows non-leftlinear equations.
   998 Declare with attribute [code nbe].
   999 
  1000 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1001 as the structured Isar versions "cases" and "induct", cf. the
  1002 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1003 are now presented as a list of individual projections
  1004 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1005 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1006 rare situations a different rule is selected --- notably nested tuple
  1007 elimination instead of former prod.exhaust: use explicit (case_tac t
  1008 rule: prod.exhaust) here.
  1009 
  1010 * Attributes "cases", "induct", "coinduct" support "del" option.
  1011 
  1012 * Removed fact "case_split_thm", which duplicates "case_split".
  1013 
  1014 * The option datatype has been moved to a new theory Option.  Renamed
  1015 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1016 
  1017 * New predicate "strict_mono" classifies strict functions on partial
  1018 orders.  With strict functions on linear orders, reasoning about
  1019 (in)equalities is facilitated by theorems "strict_mono_eq",
  1020 "strict_mono_less_eq" and "strict_mono_less".
  1021 
  1022 * Some set operations are now proper qualified constants with
  1023 authentic syntax.  INCOMPATIBILITY:
  1024 
  1025     op Int ~>   Set.Int
  1026     op Un ~>    Set.Un
  1027     INTER ~>    Set.INTER
  1028     UNION ~>    Set.UNION
  1029     Inter ~>    Set.Inter
  1030     Union ~>    Set.Union
  1031     {} ~>       Set.empty
  1032     UNIV ~>     Set.UNIV
  1033 
  1034 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1035 theory Set.
  1036 
  1037 * Auxiliary class "itself" has disappeared -- classes without any
  1038 parameter are treated as expected by the 'class' command.
  1039 
  1040 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1041 
  1042 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1043 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1044 
  1045 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1046 method "approximation".  It proves formulas on real values by using
  1047 interval arithmetic.  In the formulas are also the transcendental
  1048 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1049 allowed. For examples see
  1050 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1051 
  1052 * Theory "Reflection" now resides in HOL/Library.
  1053 
  1054 * Entry point to Word library now simply named "Word".
  1055 INCOMPATIBILITY.
  1056 
  1057 * Made source layout more coherent with logical distribution
  1058 structure:
  1059 
  1060     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1061     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1062     src/HOL/Library/GCD.thy ~> src/HOL/
  1063     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1064     src/HOL/Library/Parity.thy ~> src/HOL/
  1065     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1066     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1067     src/HOL/Real/Lubs.thy ~> src/HOL/
  1068     src/HOL/Real/PReal.thy ~> src/HOL/
  1069     src/HOL/Real/Rational.thy ~> src/HOL/
  1070     src/HOL/Real/RComplete.thy ~> src/HOL/
  1071     src/HOL/Real/RealDef.thy ~> src/HOL/
  1072     src/HOL/Real/RealPow.thy ~> src/HOL/
  1073     src/HOL/Real/Real.thy ~> src/HOL/
  1074     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1075     src/HOL/Complex/Complex.thy ~> src/HOL/
  1076     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1077     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1078     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1079     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1080     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1081     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1082     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1083     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1084     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1085     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1086     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1087     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1088     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1089     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1090     src/HOL/Real/Float ~> src/HOL/Library/
  1091     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1092     src/HOL/Real/RealVector.thy ~> src/HOL/
  1093 
  1094     src/HOL/arith_data.ML ~> src/HOL/Tools
  1095     src/HOL/hologic.ML ~> src/HOL/Tools
  1096     src/HOL/simpdata.ML ~> src/HOL/Tools
  1097     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1098     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1099     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1100     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1101     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1102     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1103     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1104 
  1105     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1106     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1107     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1108     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1109     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1110     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1111 
  1112 * If methods "eval" and "evaluation" encounter a structured proof
  1113 state with !!/==>, only the conclusion is evaluated to True (if
  1114 possible), avoiding strange error messages.
  1115 
  1116 * Method "sizechange" automates termination proofs using (a
  1117 modification of) the size-change principle.  Requires SAT solver.  See
  1118 src/HOL/ex/Termination.thy for examples.
  1119 
  1120 * Simplifier: simproc for let expressions now unfolds if bound
  1121 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1122 
  1123 * Method "arith": Linear arithmetic now ignores all inequalities when
  1124 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1125 
  1126 * New attribute "arith" for facts that should always be used
  1127 automatically by arithmetic. It is intended to be used locally in
  1128 proofs, e.g.
  1129 
  1130   assumes [arith]: "x > 0"
  1131 
  1132 Global usage is discouraged because of possible performance impact.
  1133 
  1134 * New classes "top" and "bot" with corresponding operations "top" and
  1135 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1136 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1137 
  1138 * Changed definition lemma "less_fun_def" in order to provide an
  1139 instance for preorders on functions; use lemma "less_le" instead.
  1140 INCOMPATIBILITY.
  1141 
  1142 * Theory Orderings: class "wellorder" moved here, with explicit
  1143 induction rule "less_induct" as assumption.  For instantiation of
  1144 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1145 INCOMPATIBILITY.
  1146 
  1147 * Theory Orderings: added class "preorder" as superclass of "order".
  1148 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1149 etc. slightly changed.  Some theorems named order_class.* now named
  1150 preorder_class.*.
  1151 
  1152 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1153 "diag" to "Id_on".
  1154 
  1155 * Theory Finite_Set: added a new fold combinator of type
  1156 
  1157   ('a => 'b => 'b) => 'b => 'a set => 'b
  1158 
  1159 Occasionally this is more convenient than the old fold combinator
  1160 which is now defined in terms of the new one and renamed to
  1161 fold_image.
  1162 
  1163 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1164 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1165 extended with further lemmas!).  At the moment both still exist but
  1166 the former will disappear at some point.
  1167 
  1168 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1169 class recpower.  Type-specific simp rules for various recpower types
  1170 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1171 
  1172 rat_power_0    -> power_0
  1173 rat_power_Suc  -> power_Suc
  1174 realpow_0      -> power_0
  1175 realpow_Suc    -> power_Suc
  1176 complexpow_0   -> power_0
  1177 complexpow_Suc -> power_Suc
  1178 power_poly_0   -> power_0
  1179 power_poly_Suc -> power_Suc
  1180 
  1181 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1182 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1183 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1184 of lemmas from Divides has been generalized from nat to class
  1185 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1186 renames resulting from duplicate elimination:
  1187 
  1188     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1189     zero_dvd_iff ~>         dvd_0_left_iff
  1190     dvd_0 ~>                dvd_0_right
  1191     DIVISION_BY_ZERO_DIV ~> div_by_0
  1192     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1193     mult_div ~>             div_mult_self2_is_id
  1194     mult_mod ~>             mod_mult_self2_is_0
  1195 
  1196 * Theory IntDiv: removed many lemmas that are instances of class-based
  1197 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1198 rename old lemmas as follows:
  1199 
  1200 dvd_diff               -> nat_dvd_diff
  1201 dvd_zminus_iff         -> dvd_minus_iff
  1202 mod_add1_eq            -> mod_add_eq
  1203 mod_mult1_eq           -> mod_mult_right_eq
  1204 mod_mult1_eq'          -> mod_mult_left_eq
  1205 mod_mult_distrib_mod   -> mod_mult_eq
  1206 nat_mod_add_left_eq    -> mod_add_left_eq
  1207 nat_mod_add_right_eq   -> mod_add_right_eq
  1208 nat_mod_div_trivial    -> mod_div_trivial
  1209 nat_mod_mod_trivial    -> mod_mod_trivial
  1210 zdiv_zadd_self1        -> div_add_self1
  1211 zdiv_zadd_self2        -> div_add_self2
  1212 zdiv_zmult_self1       -> div_mult_self2_is_id
  1213 zdiv_zmult_self2       -> div_mult_self1_is_id
  1214 zdvd_triv_left         -> dvd_triv_left
  1215 zdvd_triv_right        -> dvd_triv_right
  1216 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1217 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1218 zmod_zadd_left_eq      -> mod_add_left_eq
  1219 zmod_zadd_right_eq     -> mod_add_right_eq
  1220 zmod_zadd_self1        -> mod_add_self1
  1221 zmod_zadd_self2        -> mod_add_self2
  1222 zmod_zadd1_eq          -> mod_add_eq
  1223 zmod_zdiff1_eq         -> mod_diff_eq
  1224 zmod_zdvd_zmod         -> mod_mod_cancel
  1225 zmod_zmod_cancel       -> mod_mod_cancel
  1226 zmod_zmult_self1       -> mod_mult_self2_is_0
  1227 zmod_zmult_self2       -> mod_mult_self1_is_0
  1228 zmod_1                 -> mod_by_1
  1229 zdiv_1                 -> div_by_1
  1230 zdvd_abs1              -> abs_dvd_iff
  1231 zdvd_abs2              -> dvd_abs_iff
  1232 zdvd_refl              -> dvd_refl
  1233 zdvd_trans             -> dvd_trans
  1234 zdvd_zadd              -> dvd_add
  1235 zdvd_zdiff             -> dvd_diff
  1236 zdvd_zminus_iff        -> dvd_minus_iff
  1237 zdvd_zminus2_iff       -> minus_dvd_iff
  1238 zdvd_zmultD            -> dvd_mult_right
  1239 zdvd_zmultD2           -> dvd_mult_left
  1240 zdvd_zmult_mono        -> mult_dvd_mono
  1241 zdvd_0_right           -> dvd_0_right
  1242 zdvd_0_left            -> dvd_0_left_iff
  1243 zdvd_1_left            -> one_dvd
  1244 zminus_dvd_iff         -> minus_dvd_iff
  1245 
  1246 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1247 
  1248 * The real numbers offer decimal input syntax: 12.34 is translated
  1249 into 1234/10^2. This translation is not reversed upon output.
  1250 
  1251 * Theory Library/Polynomial defines an abstract type 'a poly of
  1252 univariate polynomials with coefficients of type 'a.  In addition to
  1253 the standard ring operations, it also supports div and mod.  Code
  1254 generation is also supported, using list-style constructors.
  1255 
  1256 * Theory Library/Inner_Product defines a class of real_inner for real
  1257 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1258 => real.  Class real_inner is a subclass of real_normed_vector from
  1259 theory RealVector.
  1260 
  1261 * Theory Library/Product_Vector provides instances for the product
  1262 type 'a * 'b of several classes from RealVector and Inner_Product.
  1263 Definitions of addition, subtraction, scalar multiplication, norms,
  1264 and inner products are included.
  1265 
  1266 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1267 addition to the field operations, numerals and case syntax are also
  1268 supported.
  1269 
  1270 * Theory Library/Diagonalize provides constructive version of Cantor's
  1271 first diagonalization argument.
  1272 
  1273 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1274 zlcm (for int); carried together from various gcd/lcm developements in
  1275 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1276 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1277 may recover tupled syntax as follows:
  1278 
  1279     hide (open) const gcd
  1280     abbreviation gcd where
  1281       "gcd == (%(a, b). GCD.gcd a b)"
  1282     notation (output)
  1283       GCD.gcd ("gcd '(_, _')")
  1284 
  1285 The same works for lcm, zgcd, zlcm.
  1286 
  1287 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1288 instantiations for algebraic structures.  Removed some duplicate
  1289 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1290 
  1291 * ML antiquotation @{code} takes a constant as argument and generates
  1292 corresponding code in background and inserts name of the corresponding
  1293 resulting ML value/function/datatype constructor binding in place.
  1294 All occurrences of @{code} with a single ML block are generated
  1295 simultaneously.  Provides a generic and safe interface for
  1296 instrumentalizing code generation.  See
  1297 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1298 In future you ought to refrain from ad-hoc compiling generated SML
  1299 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1300 cannot refer to constants for which user-defined serializations are
  1301 set.  Refer to the corresponding ML counterpart directly in that
  1302 cases.
  1303 
  1304 * Command 'rep_datatype': instead of theorem names the command now
  1305 takes a list of terms denoting the constructors of the type to be
  1306 represented as datatype.  The characteristic theorems have to be
  1307 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1308 have disappeared in favour of existing ones:
  1309 
  1310     unit_induct                 ~> unit.induct
  1311     prod_induct                 ~> prod.induct
  1312     sum_induct                  ~> sum.induct
  1313     Suc_Suc_eq                  ~> nat.inject
  1314     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1315 
  1316 
  1317 *** HOL-Algebra ***
  1318 
  1319 * New locales for orders and lattices where the equivalence relation
  1320 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1321 locales use a record structure with field eq for the equivalence.
  1322 
  1323 * New theory of factorial domains.
  1324 
  1325 * Units_l_inv and Units_r_inv are now simp rules by default.
  1326 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1327 and/or r_inv will now also require deletion of these lemmas.
  1328 
  1329 * Renamed the following theorems, INCOMPATIBILITY:
  1330 
  1331 UpperD ~> Upper_memD
  1332 LowerD ~> Lower_memD
  1333 least_carrier ~> least_closed
  1334 greatest_carrier ~> greatest_closed
  1335 greatest_Lower_above ~> greatest_Lower_below
  1336 one_zero ~> carrier_one_zero
  1337 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1338 
  1339 
  1340 *** HOL-Nominal ***
  1341 
  1342 * Nominal datatypes can now contain type-variables.
  1343 
  1344 * Commands 'nominal_inductive' and 'equivariance' work with local
  1345 theory targets.
  1346 
  1347 * Nominal primrec can now works with local theory targets and its
  1348 specification syntax now conforms to the general format as seen in
  1349 'inductive' etc.
  1350 
  1351 * Method "perm_simp" honours the standard simplifier attributes
  1352 (no_asm), (no_asm_use) etc.
  1353 
  1354 * The new predicate #* is defined like freshness, except that on the
  1355 left hand side can be a set or list of atoms.
  1356 
  1357 * Experimental command 'nominal_inductive2' derives strong induction
  1358 principles for inductive definitions.  In contrast to
  1359 'nominal_inductive', which can only deal with a fixed number of
  1360 binders, it can deal with arbitrary expressions standing for sets of
  1361 atoms to be avoided.  The only inductive definition we have at the
  1362 moment that needs this generalisation is the typing rule for Lets in
  1363 the algorithm W:
  1364 
  1365  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1366  -----------------------------------------------------------------
  1367          Gamma |- Let x be t1 in t2 : T2
  1368 
  1369 In this rule one wants to avoid all the binders that are introduced by
  1370 "close Gamma T1".  We are looking for other examples where this
  1371 feature might be useful.  Please let us know.
  1372 
  1373 
  1374 *** HOLCF ***
  1375 
  1376 * Reimplemented the simplification procedure for proving continuity
  1377 subgoals.  The new simproc is extensible; users can declare additional
  1378 continuity introduction rules with the attribute [cont2cont].
  1379 
  1380 * The continuity simproc now uses a different introduction rule for
  1381 solving continuity subgoals on terms with lambda abstractions.  In
  1382 some rare cases the new simproc may fail to solve subgoals that the
  1383 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1384 Potential INCOMPATIBILITY.
  1385 
  1386 * Command 'fixrec': specification syntax now conforms to the general
  1387 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1388 examples.  INCOMPATIBILITY.
  1389 
  1390 
  1391 *** ZF ***
  1392 
  1393 * Proof of Zorn's Lemma for partial orders.
  1394 
  1395 
  1396 *** ML ***
  1397 
  1398 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1399 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1400 depends on multithreading, so timouts will not work before Poly/ML
  1401 5.2.1!
  1402 
  1403 * High-level support for concurrent ML programming, see
  1404 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1405 particularly convenient to organize independent functional
  1406 computations.  The concept of "synchronized variables" provides a
  1407 higher-order interface for components with shared state, avoiding the
  1408 delicate details of mutexes and condition variables.  (Requires
  1409 Poly/ML 5.2.1 or later.)
  1410 
  1411 * ML bindings produced via Isar commands are stored within the Isar
  1412 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1413 become thread-safe and work with undo as expected (concerning
  1414 top-level bindings, not side-effects on global references).
  1415 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1416 compiler at runtime; really global bindings need to be given outside a
  1417 theory.  (Requires Poly/ML 5.2 or later.)
  1418 
  1419 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1420 context.  Top-level ML bindings are stored within the proof context in
  1421 a purely sequential fashion, disregarding the nested proof structure.
  1422 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1423 proof.  (Requires Poly/ML 5.2 or later.)
  1424 
  1425 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1426 and Method.setup, as well as Isar commands 'attribute_setup' and
  1427 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1428 existing code accordingly, or use plain 'setup' together with old
  1429 Method.add_method.
  1430 
  1431 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1432 to 'a -> thm, while results are always tagged with an authentic oracle
  1433 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1434 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1435 accordingly.  Note that extra performance may be gained by producing
  1436 the cterm carefully, avoiding slow Thm.cterm_of.
  1437 
  1438 * Simplified interface for defining document antiquotations via
  1439 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1440 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1441 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1442 examples.
  1443 
  1444 * More systematic treatment of long names, abstract name bindings, and
  1445 name space operations.  Basic operations on qualified names have been
  1446 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1447 Long_Name.append.  Old type bstring has been mostly replaced by
  1448 abstract type binding (see structure Binding), which supports precise
  1449 qualification by packages and local theory targets, as well as proper
  1450 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1451 bstring values into Binding.name, or better pass through abstract
  1452 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1453 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1454 
  1455 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1456 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1457 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1458 
  1459 * Disposed old type and term read functions (Sign.read_def_typ,
  1460 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1461 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1462 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1463 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1464 resort for legacy applications.
  1465 
  1466 * Disposed old declarations, tactics, tactic combinators that refer to
  1467 the simpset or claset of an implicit theory (such as Addsimps,
  1468 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1469 embedded ML text, or local_simpset_of with a proper context passed as
  1470 explicit runtime argument.
  1471 
  1472 * Rules and tactics that read instantiations (read_instantiate,
  1473 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1474 context, which is required for parsing and type-checking.  Moreover,
  1475 the variables are specified as plain indexnames, not string encodings
  1476 thereof.  INCOMPATIBILITY.
  1477 
  1478 * Generic Toplevel.add_hook interface allows to analyze the result of
  1479 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1480 for theorem dependency output of transactions resulting in a new
  1481 theory state.
  1482 
  1483 * ML antiquotations: block-structured compilation context indicated by
  1484 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1485 
  1486   @{binding name}                         - basic name binding
  1487   @{let ?pat = term}                      - term abbreviation (HO matching)
  1488   @{note name = fact}                     - fact abbreviation
  1489   @{thm fact}                             - singleton fact (with attributes)
  1490   @{thms fact}                            - general fact (with attributes)
  1491   @{lemma prop by method}                 - singleton goal
  1492   @{lemma prop by meth1 meth2}            - singleton goal
  1493   @{lemma prop1 ... propN by method}      - general goal
  1494   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1495   @{lemma (open) ...}                     - open derivation
  1496 
  1497 
  1498 *** System ***
  1499 
  1500 * The Isabelle "emacs" tool provides a specific interface to invoke
  1501 Proof General / Emacs, with more explicit failure if that is not
  1502 installed (the old isabelle-interface script silently falls back on
  1503 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1504 installation location of the Proof General distribution.
  1505 
  1506 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1507 the Isabelle process into a JVM/Scala application.  See
  1508 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1509 process wrapper has been discontinued.)
  1510 
  1511 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1512 
  1513 * Various status messages (with exact source position information) are
  1514 emitted, if proper markup print mode is enabled.  This allows
  1515 user-interface components to provide detailed feedback on internal
  1516 prover operations.
  1517 
  1518 
  1519 
  1520 New in Isabelle2008 (June 2008)
  1521 -------------------------------
  1522 
  1523 *** General ***
  1524 
  1525 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1526 and updated, with formally checked references as hyperlinks.
  1527 
  1528 * Theory loader: use_thy (and similar operations) no longer set the
  1529 implicit ML context, which was occasionally hard to predict and in
  1530 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1531 provides a proper context already.
  1532 
  1533 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1534 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1535 'use' within a theory file will do the job.
  1536 
  1537 * Name space merge now observes canonical order, i.e. the second space
  1538 is inserted into the first one, while existing entries in the first
  1539 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1540 swap theory imports.
  1541 
  1542 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1543 INCOMPATIBILITY in identifier syntax etc.
  1544 
  1545 * Outer syntax: string tokens no longer admit escaped white space,
  1546 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1547 white space without escapes.
  1548 
  1549 * Outer syntax: string tokens may contain arbitrary character codes
  1550 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1551 "foo_bar".
  1552 
  1553 
  1554 *** Pure ***
  1555 
  1556 * Context-dependent token translations.  Default setup reverts locally
  1557 fixed variables, and adds hilite markup for undeclared frees.
  1558 
  1559 * Unused theorems can be found using the new command 'unused_thms'.
  1560 There are three ways of invoking it:
  1561 
  1562 (1) unused_thms
  1563      Only finds unused theorems in the current theory.
  1564 
  1565 (2) unused_thms thy_1 ... thy_n -
  1566      Finds unused theorems in the current theory and all of its ancestors,
  1567      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1568 
  1569 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1570      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1571      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1572      their ancestors.
  1573 
  1574 In order to increase the readability of the list produced by
  1575 unused_thms, theorems that have been created by a particular instance
  1576 of a theory command such as 'inductive' or 'function' are considered
  1577 to belong to the same "group", meaning that if at least one theorem in
  1578 this group is used, the other theorems in the same group are no longer
  1579 reported as unused.  Moreover, if all theorems in the group are
  1580 unused, only one theorem in the group is displayed.
  1581 
  1582 Note that proof objects have to be switched on in order for
  1583 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1584 usually the case when using Proof General with the default settings).
  1585 
  1586 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1587 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1588 duplicate fact bindings, or even accidental fact duplications.  Note
  1589 that tools may maintain dynamically scoped facts systematically, using
  1590 PureThy.add_thms_dynamic.
  1591 
  1592 * Command 'hide' now allows to hide from "fact" name space as well.
  1593 
  1594 * Eliminated destructive theorem database, simpset, claset, and
  1595 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1596 update of theories within ML code.
  1597 
  1598 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1599 INCOMPATIBILITY, object-logics depending on former Pure require
  1600 additional setup PureThy.old_appl_syntax_setup; object-logics
  1601 depending on former CPure need to refer to Pure.
  1602 
  1603 * Commands 'use' and 'ML' are now purely functional, operating on
  1604 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1605 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1606 INCOMPATIBILITY.
  1607 
  1608 * Command 'setup': discontinued implicit version with ML reference.
  1609 
  1610 * Instantiation target allows for simultaneous specification of class
  1611 instance operations together with an instantiation proof.
  1612 Type-checking phase allows to refer to class operations uniformly.
  1613 See src/HOL/Complex/Complex.thy for an Isar example and
  1614 src/HOL/Library/Eval.thy for an ML example.
  1615 
  1616 * Indexing of literal facts: be more serious about including only
  1617 facts from the visible specification/proof context, but not the
  1618 background context (locale etc.).  Affects `prop` notation and method
  1619 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1620 situations.
  1621 
  1622 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1623 "(open)" option, which used to expose internal bound variables to the
  1624 proof text.
  1625 
  1626 * Isar statements: removed obsolete case "rule_context".
  1627 INCOMPATIBILITY, better use explicit fixes/assumes.
  1628 
  1629 * Locale proofs: default proof step now includes 'unfold_locales';
  1630 hence 'proof' without argument may be used to unfold locale
  1631 predicates.
  1632 
  1633 
  1634 *** Document preparation ***
  1635 
  1636 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1637 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1638 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1639 spot); renamed link color from "darkblue" to "linkcolor" (default
  1640 value unchanged, can be redefined via \definecolor); no longer sets
  1641 "a4paper" option (unnecessary or even intrusive).
  1642 
  1643 * Antiquotation @{lemma A method} proves proposition A by the given
  1644 method (either a method name or a method name plus (optional) method
  1645 arguments in parentheses) and prints A just like @{prop A}.
  1646 
  1647 
  1648 *** HOL ***
  1649 
  1650 * New primrec package.  Specification syntax conforms in style to
  1651 definition/function/....  No separate induction rule is provided.  The
  1652 "primrec" command distinguishes old-style and new-style specifications
  1653 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1654 When adjusting theories, beware: constants stemming from new-style
  1655 primrec specifications have authentic syntax.
  1656 
  1657 * Metis prover is now an order of magnitude faster, and also works
  1658 with multithreading.
  1659 
  1660 * Metis: the maximum number of clauses that can be produced from a
  1661 theorem is now given by the attribute max_clauses.  Theorems that
  1662 exceed this number are ignored, with a warning printed.
  1663 
  1664 * Sledgehammer no longer produces structured proofs by default. To
  1665 enable, declare [[sledgehammer_full = true]].  Attributes
  1666 reconstruction_modulus, reconstruction_sorts renamed
  1667 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1668 
  1669 * Method "induct_scheme" derives user-specified induction rules
  1670 from well-founded induction and completeness of patterns. This factors
  1671 out some operations that are done internally by the function package
  1672 and makes them available separately.  See
  1673 src/HOL/ex/Induction_Scheme.thy for examples.
  1674 
  1675 * More flexible generation of measure functions for termination
  1676 proofs: Measure functions can be declared by proving a rule of the
  1677 form "is_measure f" and giving it the [measure_function] attribute.
  1678 The "is_measure" predicate is logically meaningless (always true), and
  1679 just guides the heuristic.  To find suitable measure functions, the
  1680 termination prover sets up the goal "is_measure ?f" of the appropriate
  1681 type and generates all solutions by prolog-style backwards proof using
  1682 the declared rules.
  1683 
  1684 This setup also deals with rules like 
  1685 
  1686   "is_measure f ==> is_measure (list_size f)"
  1687 
  1688 which accommodates nested datatypes that recurse through lists.
  1689 Similar rules are predeclared for products and option types.
  1690 
  1691 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1692 
  1693   INCOMPATIBILITIES:
  1694 
  1695   - Definitions of overloaded constants on sets have to be replaced by
  1696     definitions on => and bool.
  1697 
  1698   - Some definitions of overloaded operators on sets can now be proved
  1699     using the definitions of the operators on => and bool.  Therefore,
  1700     the following theorems have been renamed:
  1701 
  1702       subset_def   -> subset_eq
  1703       psubset_def  -> psubset_eq
  1704       set_diff_def -> set_diff_eq
  1705       Compl_def    -> Compl_eq
  1706       Sup_set_def  -> Sup_set_eq
  1707       Inf_set_def  -> Inf_set_eq
  1708       sup_set_def  -> sup_set_eq
  1709       inf_set_def  -> inf_set_eq
  1710 
  1711   - Due to the incompleteness of the HO unification algorithm, some
  1712     rules such as subst may require manual instantiation, if some of
  1713     the unknowns in the rule is a set.
  1714 
  1715   - Higher order unification and forward proofs:
  1716     The proof pattern
  1717 
  1718       have "P (S::'a set)" <...>
  1719       then have "EX S. P S" ..
  1720 
  1721     no longer works (due to the incompleteness of the HO unification
  1722     algorithm) and must be replaced by the pattern
  1723 
  1724       have "EX S. P S"
  1725       proof
  1726         show "P S" <...>
  1727       qed
  1728 
  1729   - Calculational reasoning with subst (or similar rules):
  1730     The proof pattern
  1731 
  1732       have "P (S::'a set)" <...>
  1733       also have "S = T" <...>
  1734       finally have "P T" .
  1735 
  1736     no longer works (for similar reasons as the previous example) and
  1737     must be replaced by something like
  1738 
  1739       have "P (S::'a set)" <...>
  1740       moreover have "S = T" <...>
  1741       ultimately have "P T" by simp
  1742 
  1743   - Tactics or packages written in ML code:
  1744     Code performing pattern matching on types via
  1745 
  1746       Type ("set", [T]) => ...
  1747 
  1748     must be rewritten. Moreover, functions like strip_type or
  1749     binder_types no longer return the right value when applied to a
  1750     type of the form
  1751 
  1752       T1 => ... => Tn => U => bool
  1753 
  1754     rather than
  1755 
  1756       T1 => ... => Tn => U set
  1757 
  1758 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1759 Wellfounded_Relations to theory Wellfounded.
  1760 
  1761 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1762 
  1763 * Class finite no longer treats UNIV as class parameter.  Use class
  1764 enum from theory Library/Enum instead to achieve a similar effect.
  1765 INCOMPATIBILITY.
  1766 
  1767 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1768 and "Cons".  INCOMPATIBILITY.
  1769 
  1770 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1771 Potential INCOMPATIBILITY.
  1772 
  1773 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1774 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1775 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1776 
  1777 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1778 the same name in theory Orderings:
  1779 
  1780   less_trans
  1781   less_linear
  1782   le_imp_less_or_eq
  1783   le_less_trans
  1784   less_le_trans
  1785   less_not_sym
  1786   less_asym
  1787 
  1788 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1789 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1790 and different variable names.
  1791 
  1792 * Library/Option_ord.thy: Canonical order on option type.
  1793 
  1794 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1795 finite maps.
  1796 
  1797 * Library/Countable.thy: Type class for countable types.
  1798 
  1799 * Theory Int: The representation of numerals has changed.  The infix
  1800 operator BIT and the bit datatype with constructors B0 and B1 have
  1801 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1802 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1803 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1804 accordingly.
  1805 
  1806 * Theory Nat: definition of <= and < on natural numbers no longer
  1807 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1808 le_def and less_def have disappeared.  Consider lemmas not_less
  1809 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1810 
  1811 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1812 (whose purpose mainly is for various fold_set functionals) have been
  1813 abandoned in favor of the existing algebraic classes
  1814 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1815 lower_semilattice (resp. upper_semilattice) and linorder.
  1816 INCOMPATIBILITY.
  1817 
  1818 * Theory Transitive_Closure: induct and cases rules now declare proper
  1819 case_names ("base" and "step").  INCOMPATIBILITY.
  1820 
  1821 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1822 lattices.  The form set-specific version is available as
  1823 Inductive.lfp_ordinal_induct_set.
  1824 
  1825 * Renamed theorems "power.simps" to "power_int.simps".
  1826 INCOMPATIBILITY.
  1827 
  1828 * Class semiring_div provides basic abstract properties of semirings
  1829 with division and modulo operations.  Subsumes former class dvd_mod.
  1830 
  1831 * Merged theories IntDef, Numeral and IntArith into unified theory
  1832 Int.  INCOMPATIBILITY.
  1833 
  1834 * Theory Library/Code_Index: type "index" now represents natural
  1835 numbers rather than integers.  INCOMPATIBILITY.
  1836 
  1837 * New class "uminus" with operation "uminus" (split of from class
  1838 "minus" which now only has operation "minus", binary).
  1839 INCOMPATIBILITY.
  1840 
  1841 * Constants "card", "internal_split", "option_map" now with authentic
  1842 syntax.  INCOMPATIBILITY.
  1843 
  1844 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1845 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1846 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1847 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1848 Sup_set_def, le_def, less_def, option_map_def now with object
  1849 equality.  INCOMPATIBILITY.
  1850 
  1851 * Records. Removed K_record, and replaced it by pure lambda term
  1852 %x. c. The simplifier setup is now more robust against eta expansion.
  1853 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1854 
  1855 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1856 
  1857 * Library/ListVector: new theory of arithmetic vector operations.
  1858 
  1859 * Library/Order_Relation: new theory of various orderings as sets of
  1860 pairs.  Defines preorders, partial orders, linear orders and
  1861 well-orders on sets and on types.
  1862 
  1863 
  1864 *** ZF ***
  1865 
  1866 * Renamed some theories to allow to loading both ZF and HOL in the
  1867 same session:
  1868 
  1869   Datatype  -> Datatype_ZF
  1870   Inductive -> Inductive_ZF
  1871   Int       -> Int_ZF
  1872   IntDiv    -> IntDiv_ZF
  1873   Nat       -> Nat_ZF
  1874   List      -> List_ZF
  1875   Main      -> Main_ZF
  1876 
  1877 INCOMPATIBILITY: ZF theories that import individual theories below
  1878 Main might need to be adapted.  Regular theory Main is still
  1879 available, as trivial extension of Main_ZF.
  1880 
  1881 
  1882 *** ML ***
  1883 
  1884 * ML within Isar: antiquotation @{const name} or @{const
  1885 name(typargs)} produces statically-checked Const term.
  1886 
  1887 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1888 (of the same name).  Removed obsolete print command.
  1889 
  1890 * Removed obsolete "use_legacy_bindings" function.
  1891 
  1892 * The ``print mode'' is now a thread-local value derived from a global
  1893 template (the former print_mode reference), thus access becomes
  1894 non-critical.  The global print_mode reference is for session
  1895 management only; user-code should use print_mode_value,
  1896 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1897 
  1898 * Functions system/system_out provide a robust way to invoke external
  1899 shell commands, with propagation of interrupts (requires Poly/ML
  1900 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1901 
  1902 
  1903 *** System ***
  1904 
  1905 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1906 in accordance with Proof General 3.7, which prefers GNU emacs.
  1907 
  1908 * isatool tty runs Isabelle process with plain tty interaction;
  1909 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1910 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1911 
  1912 * isatool browser now works with Cygwin as well, using general
  1913 "javapath" function defined in Isabelle process environment.
  1914 
  1915 * YXML notation provides a simple and efficient alternative to
  1916 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1917 isatool yxml as described in the Isabelle system manual.
  1918 
  1919 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1920 provides general wrapper for managing an Isabelle process in a robust
  1921 fashion, with ``cooked'' output from stdin/stderr.
  1922 
  1923 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1924 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1925 
  1926 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1927 way of changing the user's settings is via
  1928 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1929 script.
  1930 
  1931 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1932 cores of the underlying machine, which is a good starting point for
  1933 optimal performance tuning.  The corresponding usedir option -M allows
  1934 "max" as an alias for "0".  WARNING: does not work on certain versions
  1935 of Mac OS (with Poly/ML 5.1).
  1936 
  1937 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1938 adverse effect of Isabelle flooding interactive front-ends (notably
  1939 ProofGeneral / XEmacs).
  1940 
  1941 
  1942 
  1943 New in Isabelle2007 (November 2007)
  1944 -----------------------------------
  1945 
  1946 *** General ***
  1947 
  1948 * More uniform information about legacy features, notably a
  1949 warning/error of "Legacy feature: ...", depending on the state of the
  1950 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1951 legacy features will disappear eventually.
  1952 
  1953 * Theory syntax: the header format ``theory A = B + C:'' has been
  1954 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1955 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1956 
  1957 * Theory syntax: the old non-Isar theory file format has been
  1958 discontinued altogether.  Note that ML proof scripts may still be used
  1959 with Isar theories; migration is usually quite simple with the ML
  1960 function use_legacy_bindings.  INCOMPATIBILITY.
  1961 
  1962 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1963 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1964 quotes.
  1965 
  1966 * Theory loader: be more serious about observing the static theory
  1967 header specifications (including optional directories), but not the
  1968 accidental file locations of previously successful loads.  The strict
  1969 update policy of former update_thy is now already performed by
  1970 use_thy, so the former has been removed; use_thys updates several
  1971 theories simultaneously, just as 'imports' within a theory header
  1972 specification, but without merging the results.  Potential
  1973 INCOMPATIBILITY: may need to refine theory headers and commands
  1974 ROOT.ML which depend on load order.
  1975 
  1976 * Theory loader: optional support for content-based file
  1977 identification, instead of the traditional scheme of full physical
  1978 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1979 (cf. the system manual).  The new scheme allows to work with
  1980 non-finished theories in persistent session images, such that source
  1981 files may be moved later on without requiring reloads.
  1982 
  1983 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1984 file (with the same base name as the theory) are considered a legacy
  1985 feature, which will disappear eventually. Even now, the theory loader
  1986 no longer maintains dependencies on such files.
  1987 
  1988 * Syntax: the scope for resolving ambiguities via type-inference is
  1989 now limited to individual terms, instead of whole simultaneous
  1990 specifications as before. This greatly reduces the complexity of the
  1991 syntax module and improves flexibility by separating parsing and
  1992 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1993 'fixes' etc.) are required in rare situations.
  1994 
  1995 * Syntax: constants introduced by new-style packages ('definition',
  1996 'abbreviation' etc.) are passed through the syntax module in
  1997 ``authentic mode''. This means that associated mixfix annotations
  1998 really stick to such constants, independently of potential name space
  1999 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2000 trees are represented slightly differently, may need to adapt syntax
  2001 translations accordingly. Use CONST marker in 'translations' and
  2002 @{const_syntax} antiquotation in 'parse_translation' etc.
  2003 
  2004 * Legacy goal package: reduced interface to the bare minimum required
  2005 to keep existing proof scripts running.  Most other user-level
  2006 functions are now part of the OldGoals structure, which is *not* open
  2007 by default (consider isatool expandshort before open OldGoals).
  2008 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2009 these tend to cause confusion about the actual goal (!) context being
  2010 used here, which is not necessarily the same as the_context().
  2011 
  2012 * Command 'find_theorems': supports "*" wild-card in "name:"
  2013 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2014 support a specific search form (see ProofGeneral/CHANGES).
  2015 
  2016 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2017 by default, which means that "prems" (and also "fixed variables") are
  2018 suppressed from proof state output.  Note that the ProofGeneral
  2019 settings mechanism allows to change and save options persistently, but
  2020 older versions of Isabelle will fail to start up if a negative prems
  2021 limit is imposed.
  2022 
  2023 * Local theory targets may be specified by non-nested blocks of
  2024 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2025 contain definitions, theorems etc., including any derived mechanism
  2026 that has been implemented on top of these primitives.  This concept
  2027 generalizes the existing ``theorem (in ...)'' towards more versatility
  2028 and scalability.
  2029 
  2030 * Proof General interface: proper undo of final 'end' command;
  2031 discontinued Isabelle/classic mode (ML proof scripts).
  2032 
  2033 
  2034 *** Document preparation ***
  2035 
  2036 * Added antiquotation @{theory name} which prints the given name,
  2037 after checking that it refers to a valid ancestor theory in the
  2038 current context.
  2039 
  2040 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2041 check the given source text as ML type/structure, printing verbatim.
  2042 
  2043 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2044 "c args == rhs" given in the current context.  (Any number of
  2045 arguments may be given on the LHS.)
  2046 
  2047 
  2048 *** Pure ***
  2049 
  2050 * The 'class' package offers a combination of axclass and locale to
  2051 achieve Haskell-like type classes in Isabelle.  Definitions and
  2052 theorems within a class context produce both relative results (with
  2053 implicit parameters according to the locale context), and polymorphic
  2054 constants with qualified polymorphism (according to the class
  2055 context).  Within the body context of a 'class' target, a separate
  2056 syntax layer ("user space type system") takes care of converting
  2057 between global polymorphic consts and internal locale representation.
  2058 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2059 "isatool doc classes" provides a tutorial.
  2060 
  2061 * Generic code generator framework allows to generate executable
  2062 code for ML and Haskell (including Isabelle classes).  A short usage
  2063 sketch:
  2064 
  2065     internal compilation:
  2066         export_code <list of constants (term syntax)> in SML
  2067     writing SML code to a file:
  2068         export_code <list of constants (term syntax)> in SML <filename>
  2069     writing OCaml code to a file:
  2070         export_code <list of constants (term syntax)> in OCaml <filename>
  2071     writing Haskell code to a bunch of files:
  2072         export_code <list of constants (term syntax)> in Haskell <filename>
  2073 
  2074     evaluating closed propositions to True/False using code generation:
  2075         method ``eval''
  2076 
  2077 Reasonable default setup of framework in HOL.
  2078 
  2079 Theorem attributs for selecting and transforming function equations theorems:
  2080 
  2081     [code fun]:        select a theorem as function equation for a specific constant
  2082     [code fun del]:    deselect a theorem as function equation for a specific constant
  2083     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2084     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2085 
  2086 User-defined serializations (target in {SML, OCaml, Haskell}):
  2087 
  2088     code_const <and-list of constants (term syntax)>
  2089       {(target) <and-list of const target syntax>}+
  2090 
  2091     code_type <and-list of type constructors>
  2092       {(target) <and-list of type target syntax>}+
  2093 
  2094     code_instance <and-list of instances>
  2095       {(target)}+
  2096         where instance ::= <type constructor> :: <class>
  2097 
  2098     code_class <and_list of classes>
  2099       {(target) <and-list of class target syntax>}+
  2100         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2101 
  2102 code_instance and code_class only are effective to target Haskell.
  2103 
  2104 For example usage see src/HOL/ex/Codegenerator.thy and
  2105 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2106 generation from Isabelle/HOL theories is available via "isatool doc
  2107 codegen".
  2108 
  2109 * Code generator: consts in 'consts_code' Isar commands are now
  2110 referred to by usual term syntax (including optional type
  2111 annotations).
  2112 
  2113 * Command 'no_translations' removes translation rules from theory
  2114 syntax.
  2115 
  2116 * Overloaded definitions are now actually checked for acyclic
  2117 dependencies.  The overloading scheme is slightly more general than
  2118 that of Haskell98, although Isabelle does not demand an exact
  2119 correspondence to type class and instance declarations.
  2120 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2121 exotic versions of overloading -- at the discretion of the user!
  2122 
  2123 Polymorphic constants are represented via type arguments, i.e. the
  2124 instantiation that matches an instance against the most general
  2125 declaration given in the signature.  For example, with the declaration
  2126 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2127 as c(nat).  Overloading is essentially simultaneous structural
  2128 recursion over such type arguments.  Incomplete specification patterns
  2129 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2130 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2131 Command 'print_theory' outputs the normalized system of recursive
  2132 equations, see section "definitions".
  2133 
  2134 * Configuration options are maintained within the theory or proof
  2135 context (with name and type bool/int/string), providing a very simple
  2136 interface to a poor-man's version of general context data.  Tools may
  2137 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2138 these values using Config.get etc.  Users may change options via an
  2139 associated attribute of the same name.  This form of context
  2140 declaration works particularly well with commands 'declare' or
  2141 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2142 very easy to avoid global references, which would not observe Isar
  2143 toplevel undo/redo and fail to work with multithreading.
  2144 
  2145 Various global ML references of Pure and HOL have been turned into
  2146 configuration options:
  2147 
  2148   Unify.search_bound		unify_search_bound
  2149   Unify.trace_bound		unify_trace_bound
  2150   Unify.trace_simp		unify_trace_simp
  2151   Unify.trace_types		unify_trace_types
  2152   Simplifier.simp_depth_limit	simp_depth_limit
  2153   Blast.depth_limit		blast_depth_limit
  2154   DatatypeProp.dtK		datatype_distinctness_limit
  2155   fast_arith_neq_limit  	fast_arith_neq_limit
  2156   fast_arith_split_limit	fast_arith_split_limit
  2157 
  2158 * Named collections of theorems may be easily installed as context
  2159 data using the functor NamedThmsFun (see also
  2160 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2161 attributes; there is also a toplevel print command.  This facility is
  2162 just a common case of general context data, which is the preferred way
  2163 for anything more complex than just a list of facts in canonical
  2164 order.
  2165 
  2166 * Isar: command 'declaration' augments a local theory by generic
  2167 declaration functions written in ML.  This enables arbitrary content
  2168 being added to the context, depending on a morphism that tells the
  2169 difference of the original declaration context wrt. the application
  2170 context encountered later on.
  2171 
  2172 * Isar: proper interfaces for simplification procedures.  Command
  2173 'simproc_setup' declares named simprocs (with match patterns, and body
  2174 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2175 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2176 
  2177 * Isar: an extra pair of brackets around attribute declarations
  2178 abbreviates a theorem reference involving an internal dummy fact,
  2179 which will be ignored later --- only the effect of the attribute on
  2180 the background context will persist.  This form of in-place
  2181 declarations is particularly useful with commands like 'declare' and
  2182 'using', for example ``have A using [[simproc a]] by simp''.
  2183 
  2184 * Isar: method "assumption" (and implicit closing of subproofs) now
  2185 takes simple non-atomic goal assumptions into account: after applying
  2186 an assumption as a rule the resulting subgoals are solved by atomic
  2187 assumption steps.  This is particularly useful to finish 'obtain'
  2188 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2189 without referring to the original premise "!!x. P x ==> thesis" in the
  2190 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2191 more permissive.
  2192 
  2193 * Isar: implicit use of prems from the Isar proof context is
  2194 considered a legacy feature.  Common applications like ``have A .''
  2195 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2196 referencing facts explicitly here improves readability and
  2197 maintainability of proof texts.
  2198 
  2199 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2200 the obtained context from the course of reasoning!  For example:
  2201 
  2202   assume "EX x y. A x & B y"   -- "any previous fact"
  2203   then guess x and y by clarify
  2204 
  2205 This technique is potentially adventurous, depending on the facts and
  2206 proof tools being involved here.
  2207 
  2208 * Isar: known facts from the proof context may be specified as literal
  2209 propositions, using ASCII back-quote syntax.  This works wherever
  2210 named facts used to be allowed so far, in proof commands, proof
  2211 methods, attributes etc.  Literal facts are retrieved from the context
  2212 according to unification of type and term parameters.  For example,
  2213 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2214 theorems in the current context, then these are valid literal facts:
  2215 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2216 
  2217 There is also a proof method "fact" which does the same composition
  2218 for explicit goal states, e.g. the following proof texts coincide with
  2219 certain special cases of literal facts:
  2220 
  2221   have "A" by fact                 ==  note `A`
  2222   have "A ==> B" by fact           ==  note `A ==> B`
  2223   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2224   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2225 
  2226 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2227 outer syntax.  Thus symbolic identifiers may be used without
  2228 additional white space in declarations like this: ``assume *: A''.
  2229 
  2230 * Isar: 'print_facts' prints all local facts of the current context,
  2231 both named and unnamed ones.
  2232 
  2233 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2234 
  2235   def x == "t" and y == "u"
  2236 
  2237 * Isar: added command 'unfolding', which is structurally similar to
  2238 'using', but affects both the goal state and facts by unfolding given
  2239 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2240 'unfolded' attribute may be replaced by first-class proof text.
  2241 
  2242 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2243 and command 'unfolding' now all support object-level equalities
  2244 (potentially conditional).  The underlying notion of rewrite rule is
  2245 analogous to the 'rule_format' attribute, but *not* that of the
  2246 Simplifier (which is usually more generous).
  2247 
  2248 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2249 premises of a theorem by n. Useful in conjunction with drule.
  2250 
  2251 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2252 method expression within a sandbox consisting of the first N
  2253 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2254 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2255 simplifies all new goals that emerge from applying rule foo to the
  2256 originally first one.
  2257 
  2258 * Isar: schematic goals are no longer restricted to higher-order
  2259 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2260 expected.
  2261 
  2262 * Isar: the conclusion of a long theorem statement is now either
  2263 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2264 (essentially a disjunction of cases with local parameters and
  2265 assumptions).  The latter allows to express general elimination rules
  2266 adequately; in this notation common elimination rules look like this:
  2267 
  2268   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2269     assumes "EX x. P x"
  2270     obtains x where "P x"
  2271 
  2272   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2273     assumes "A & B"
  2274     obtains A and B
  2275 
  2276   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2277     assumes "A | B"
  2278     obtains
  2279       A
  2280     | B
  2281 
  2282 The subsequent classical rules even refer to the formal "thesis"
  2283 explicitly:
  2284 
  2285   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2286     obtains "~ thesis"
  2287 
  2288   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2289     obtains "thesis ==> something"
  2290 
  2291 The actual proof of an 'obtains' statement is analogous to that of the
  2292 Isar proof element 'obtain', only that there may be several cases.
  2293 Optional case names may be specified in parentheses; these will be
  2294 available both in the present proof and as annotations in the
  2295 resulting rule, for later use with the 'cases' method (cf. attribute
  2296 case_names).
  2297 
  2298 * Isar: the assumptions of a long theorem statement are available as
  2299 "assms" fact in the proof context.  This is more appropriate than the
  2300 (historical) "prems", which refers to all assumptions of the current
  2301 context, including those from the target locale, proof body etc.
  2302 
  2303 * Isar: 'print_statement' prints theorems from the current theory or
  2304 proof context in long statement form, according to the syntax of a
  2305 top-level lemma.
  2306 
  2307 * Isar: 'obtain' takes an optional case name for the local context
  2308 introduction rule (default "that").
  2309 
  2310 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2311 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2312 to occur.
  2313 
  2314 * Pure: syntax "CONST name" produces a fully internalized constant
  2315 according to the current context.  This is particularly useful for
  2316 syntax translations that should refer to internal constant
  2317 representations independently of name spaces.
  2318 
  2319 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2320 instead of "FOO ". This allows multiple binder declarations to coexist
  2321 in the same context.  INCOMPATIBILITY.
  2322 
  2323 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2324 primitive that also works in a locale context (both for constants and
  2325 fixed variables). Type declaration and internal syntactic representation
  2326 of given constants retrieved from the context. Likewise, the
  2327 'no_notation' command allows to remove given syntax annotations from the
  2328 current context.
  2329 
  2330 * Isar/locales: new derived specification elements 'axiomatization',
  2331 'definition', 'abbreviation', which support type-inference, admit
  2332 object-level specifications (equality, equivalence).  See also the
  2333 isar-ref manual.  Examples:
  2334 
  2335   axiomatization
  2336     eq  (infix "===" 50) where
  2337     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2338 
  2339   definition "f x y = x + y + 1"
  2340   definition g where "g x = f x x"
  2341 
  2342   abbreviation
  2343     neq  (infix "=!=" 50) where
  2344     "x =!= y == ~ (x === y)"
  2345 
  2346 These specifications may be also used in a locale context.  Then the
  2347 constants being introduced depend on certain fixed parameters, and the
  2348 constant name is qualified by the locale base name.  An internal
  2349 abbreviation takes care for convenient input and output, making the
  2350 parameters implicit and using the original short name.  See also
  2351 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2352 entities from a monomorphic theory.
  2353 
  2354 Presently, abbreviations are only available 'in' a target locale, but
  2355 not inherited by general import expressions.  Also note that
  2356 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2357 'translations' in common applications.  The "no_abbrevs" print mode
  2358 prevents folding of abbreviations in term output.
  2359 
  2360 Concrete syntax is attached to specified constants in internal form,
  2361 independently of name spaces.  The parse tree representation is
  2362 slightly different -- use 'notation' instead of raw 'syntax', and
  2363 'translations' with explicit "CONST" markup to accommodate this.
  2364 
  2365 * Pure/Isar: unified syntax for new-style specification mechanisms
  2366 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2367 full type inference and dummy patterns ("_").  For example:
  2368 
  2369   definition "K x _ = x"
  2370 
  2371   inductive conj for A B
  2372   where "A ==> B ==> conj A B"
  2373 
  2374 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2375 the current context.  Print mode "no_abbrevs" prevents inversion of
  2376 abbreviations on output.
  2377 
  2378 * Isar/locales: improved parameter handling: use of locales "var" and
  2379 "struct" no longer necessary; - parameter renamings are no longer
  2380 required to be injective.  For example, this allows to define
  2381 endomorphisms as locale endom = homom mult mult h.
  2382 
  2383 * Isar/locales: changed the way locales with predicates are defined.
  2384 Instead of accumulating the specification, the imported expression is
  2385 now an interpretation.  INCOMPATIBILITY: different normal form of
  2386 locale expressions.  In particular, in interpretations of locales with
  2387 predicates, goals repesenting already interpreted fragments are not
  2388 removed automatically.  Use methods `intro_locales' and
  2389 `unfold_locales'; see below.
  2390 
  2391 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2392 provide backward reasoning on locales predicates.  The methods are
  2393 aware of interpretations and discharge corresponding goals.
  2394 `intro_locales' is less aggressive then `unfold_locales' and does not
  2395 unfold predicates to assumptions.
  2396 
  2397 * Isar/locales: the order in which locale fragments are accumulated
  2398 has changed.  This enables to override declarations from fragments due
  2399 to interpretations -- for example, unwanted simp rules.
  2400 
  2401 * Isar/locales: interpretation in theories and proof contexts has been
  2402 extended.  One may now specify (and prove) equations, which are
  2403 unfolded in interpreted theorems.  This is useful for replacing
  2404 defined concepts (constants depending on locale parameters) by
  2405 concepts already existing in the target context.  Example:
  2406 
  2407   interpretation partial_order ["op <= :: [int, int] => bool"]
  2408     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2409 
  2410 Typically, the constant `partial_order.less' is created by a
  2411 definition specification element in the context of locale
  2412 partial_order.
  2413 
  2414 * Method "induct": improved internal context management to support
  2415 local fixes and defines on-the-fly. Thus explicit meta-level
  2416 connectives !!  and ==> are rarely required anymore in inductive goals
  2417 (using object-logic connectives for this purpose has been long
  2418 obsolete anyway). Common proof patterns are explained in
  2419 src/HOL/Induct/Common_Patterns.thy, see also
  2420 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2421 examples.
  2422 
  2423 * Method "induct": improved handling of simultaneous goals. Instead of
  2424 introducing object-level conjunction, the statement is now split into
  2425 several conclusions, while the corresponding symbolic cases are nested
  2426 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2427 see src/HOL/Induct/Common_Patterns.thy, for example.
  2428 
  2429 * Method "induct": mutual induction rules are now specified as a list
  2430 of rule sharing the same induction cases. HOL packages usually provide
  2431 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2432 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2433 mutual induction rules differently, i.e. like this:
  2434 
  2435   (induct rule: foo_bar.inducts)
  2436   (induct set: foo bar)
  2437   (induct pred: foo bar)
  2438   (induct type: foo bar)
  2439 
  2440 The ML function ProjectRule.projections turns old-style rules into the
  2441 new format.
  2442 
  2443 * Method "coinduct": dual of induction, see
  2444 src/HOL/Library/Coinductive_List.thy for various examples.
  2445 
  2446 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2447 considered a legacy feature.
  2448 
  2449 * Attribute "symmetric" produces result with standardized schematic
  2450 variables (index 0).  Potential INCOMPATIBILITY.
  2451 
  2452 * Simplifier: by default the simplifier trace only shows top level
  2453 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2454 default. Thus there is less danger of being flooded by the trace. The
  2455 trace indicates where parts have been suppressed.
  2456   
  2457 * Provers/classical: removed obsolete classical version of elim_format
  2458 attribute; classical elim/dest rules are now treated uniformly when
  2459 manipulating the claset.
  2460 
  2461 * Provers/classical: stricter checks to ensure that supplied intro,
  2462 dest and elim rules are well-formed; dest and elim rules must have at
  2463 least one premise.
  2464 
  2465 * Provers/classical: attributes dest/elim/intro take an optional
  2466 weight argument for the rule (just as the Pure versions).  Weights are
  2467 ignored by automated tools, but determine the search order of single
  2468 rule steps.
  2469 
  2470 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2471 where the body does not mention the bound variable.  Note that dummy
  2472 patterns implicitly depend on their context of bounds, which makes
  2473 "{_. _}" match any set comprehension as expected.  Potential
  2474 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2475 constant "_idtdummy" in the binding position.
  2476 
  2477 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2478 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2479 for example "A -> B" => "Pi A (%_. B)".
  2480 
  2481 * Pure: 'class_deps' command visualizes the subclass relation, using
  2482 the graph browser tool.
  2483 
  2484 * Pure: 'print_theory' now suppresses certain internal declarations by
  2485 default; use '!' option for full details.
  2486 
  2487 
  2488 *** HOL ***
  2489 
  2490 * Method "metis" proves goals by applying the Metis general-purpose
  2491 resolution prover (see also http://gilith.com/software/metis/).
  2492 Examples are in the directory MetisExamples.  WARNING: the
  2493 Isabelle/HOL-Metis integration does not yet work properly with
  2494 multi-threading.
  2495   
  2496 * Command 'sledgehammer' invokes external automatic theorem provers as
  2497 background processes.  It generates calls to the "metis" method if
  2498 successful. These can be pasted into the proof.  Users do not have to
  2499 wait for the automatic provers to return.  WARNING: does not really
  2500 work with multi-threading.
  2501 
  2502 * New "auto_quickcheck" feature tests outermost goal statements for
  2503 potential counter-examples.  Controlled by ML references
  2504 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2505 5000 milliseconds).  Fails silently if statements is outside of
  2506 executable fragment, or any other codgenerator problem occurs.
  2507 
  2508 * New constant "undefined" with axiom "undefined x = undefined".
  2509 
  2510 * Added class "HOL.eq", allowing for code generation with polymorphic
  2511 equality.
  2512 
  2513 * Some renaming of class constants due to canonical name prefixing in
  2514 the new 'class' package:
  2515 
  2516     HOL.abs ~> HOL.abs_class.abs
  2517     HOL.divide ~> HOL.divide_class.divide
  2518     0 ~> HOL.zero_class.zero
  2519     1 ~> HOL.one_class.one
  2520     op + ~> HOL.plus_class.plus
  2521     op - ~> HOL.minus_class.minus
  2522     uminus ~> HOL.minus_class.uminus
  2523     op * ~> HOL.times_class.times
  2524     op < ~> HOL.ord_class.less
  2525     op <= > HOL.ord_class.less_eq
  2526     Nat.power ~> Power.power_class.power
  2527     Nat.size ~> Nat.size_class.size
  2528     Numeral.number_of ~> Numeral.number_class.number_of
  2529     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2530     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2531     Orderings.min ~> Orderings.ord_class.min
  2532     Orderings.max ~> Orderings.ord_class.max
  2533     Divides.op div ~> Divides.div_class.div
  2534     Divides.op mod ~> Divides.div_class.mod
  2535     Divides.op dvd ~> Divides.div_class.dvd
  2536 
  2537 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2538 
  2539 a) User-defined constants using any of the names "plus", "minus",
  2540 "times", "less" or "less_eq". The standard syntax translations for
  2541 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2542 names.
  2543 
  2544 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2545 INCOMPATIBILITY: use more specific names.
  2546 
  2547 c) Permutative equations (e.g. "a + b = b + a")
  2548 Since the change of names also changes the order of terms, permutative
  2549 rewrite rules may get applied in a different order. Experience shows
  2550 that this is rarely the case (only two adaptions in the whole Isabelle
  2551 distribution).  INCOMPATIBILITY: rewrite proofs
  2552 
  2553 d) ML code directly refering to constant names
  2554 This in general only affects hand-written proof tactics, simprocs and
  2555 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2556 Consider using @{const_name} antiquotation.
  2557 
  2558 * New class "default" with associated constant "default".
  2559 
  2560 * Function "sgn" is now overloaded and available on int, real, complex
  2561 (and other numeric types), using class "sgn".  Two possible defs of
  2562 sgn are given as equational assumptions in the classes sgn_if and
  2563 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2564 INCOMPATIBILITY.
  2565 
  2566 * Locale "partial_order" now unified with class "order" (cf. theory
  2567 Orderings), added parameter "less".  INCOMPATIBILITY.
  2568 
  2569 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2570 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2571 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2572 
  2573 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2574 changed order of proof goals in instance proofs.
  2575 
  2576 * The transitivity reasoner for partial and linear orders is set up
  2577 for classes "order" and "linorder".  Instances of the reasoner are available
  2578 in all contexts importing or interpreting the corresponding locales.
  2579 Method "order" invokes the reasoner separately; the reasoner
  2580 is also integrated with the Simplifier as a solver.  Diagnostic
  2581 command 'print_orders' shows the available instances of the reasoner
  2582 in the current context.
  2583 
  2584 * Localized monotonicity predicate in theory "Orderings"; integrated
  2585 lemmas max_of_mono and min_of_mono with this predicate.
  2586 INCOMPATIBILITY.
  2587 
  2588 * Formulation of theorem "dense" changed slightly due to integration
  2589 with new class dense_linear_order.
  2590 
  2591 * Uniform lattice theory development in HOL.
  2592 
  2593     constants "meet" and "join" now named "inf" and "sup"
  2594     constant "Meet" now named "Inf"
  2595 
  2596     classes "meet_semilorder" and "join_semilorder" now named
  2597       "lower_semilattice" and "upper_semilattice"
  2598     class "lorder" now named "lattice"
  2599     class "comp_lat" now named "complete_lattice"
  2600 
  2601     Instantiation of lattice classes allows explicit definitions
  2602     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2603 
  2604   INCOMPATIBILITY.  Theorem renames:
  2605 
  2606     meet_left_le            ~> inf_le1
  2607     meet_right_le           ~> inf_le2
  2608     join_left_le            ~> sup_ge1
  2609     join_right_le           ~> sup_ge2
  2610     meet_join_le            ~> inf_sup_ord
  2611     le_meetI                ~> le_infI
  2612     join_leI                ~> le_supI
  2613     le_meet                 ~> le_inf_iff
  2614     le_join                 ~> ge_sup_conv
  2615     meet_idempotent         ~> inf_idem
  2616     join_idempotent         ~> sup_idem
  2617     meet_comm               ~> inf_commute
  2618     join_comm               ~> sup_commute
  2619     meet_leI1               ~> le_infI1
  2620     meet_leI2               ~> le_infI2
  2621     le_joinI1               ~> le_supI1
  2622     le_joinI2               ~> le_supI2
  2623     meet_assoc              ~> inf_assoc
  2624     join_assoc              ~> sup_assoc
  2625     meet_left_comm          ~> inf_left_commute
  2626     meet_left_idempotent    ~> inf_left_idem
  2627     join_left_comm          ~> sup_left_commute
  2628     join_left_idempotent    ~> sup_left_idem
  2629     meet_aci                ~> inf_aci
  2630     join_aci                ~> sup_aci
  2631     le_def_meet             ~> le_iff_inf
  2632     le_def_join             ~> le_iff_sup
  2633     join_absorp2            ~> sup_absorb2
  2634     join_absorp1            ~> sup_absorb1
  2635     meet_absorp1            ~> inf_absorb1
  2636     meet_absorp2            ~> inf_absorb2
  2637     meet_join_absorp        ~> inf_sup_absorb
  2638     join_meet_absorp        ~> sup_inf_absorb
  2639     distrib_join_le         ~> distrib_sup_le
  2640     distrib_meet_le         ~> distrib_inf_le
  2641 
  2642     add_meet_distrib_left   ~> add_inf_distrib_left
  2643     add_join_distrib_left   ~> add_sup_distrib_left
  2644     is_join_neg_meet        ~> is_join_neg_inf
  2645     is_meet_neg_join        ~> is_meet_neg_sup
  2646     add_meet_distrib_right  ~> add_inf_distrib_right
  2647     add_join_distrib_right  ~> add_sup_distrib_right
  2648     add_meet_join_distribs  ~> add_sup_inf_distribs
  2649     join_eq_neg_meet        ~> sup_eq_neg_inf
  2650     meet_eq_neg_join        ~> inf_eq_neg_sup
  2651     add_eq_meet_join        ~> add_eq_inf_sup
  2652     meet_0_imp_0            ~> inf_0_imp_0
  2653     join_0_imp_0            ~> sup_0_imp_0
  2654     meet_0_eq_0             ~> inf_0_eq_0
  2655     join_0_eq_0             ~> sup_0_eq_0
  2656     neg_meet_eq_join        ~> neg_inf_eq_sup
  2657     neg_join_eq_meet        ~> neg_sup_eq_inf
  2658     join_eq_if              ~> sup_eq_if
  2659 
  2660     mono_meet               ~> mono_inf
  2661     mono_join               ~> mono_sup
  2662     meet_bool_eq            ~> inf_bool_eq
  2663     join_bool_eq            ~> sup_bool_eq
  2664     meet_fun_eq             ~> inf_fun_eq
  2665     join_fun_eq             ~> sup_fun_eq
  2666     meet_set_eq             ~> inf_set_eq
  2667     join_set_eq             ~> sup_set_eq
  2668     meet1_iff               ~> inf1_iff
  2669     meet2_iff               ~> inf2_iff
  2670     meet1I                  ~> inf1I
  2671     meet2I                  ~> inf2I
  2672     meet1D1                 ~> inf1D1
  2673     meet2D1                 ~> inf2D1
  2674     meet1D2                 ~> inf1D2
  2675     meet2D2                 ~> inf2D2
  2676     meet1E                  ~> inf1E
  2677     meet2E                  ~> inf2E
  2678     join1_iff               ~> sup1_iff
  2679     join2_iff               ~> sup2_iff
  2680     join1I1                 ~> sup1I1
  2681     join2I1                 ~> sup2I1
  2682     join1I1                 ~> sup1I1
  2683     join2I2                 ~> sup1I2
  2684     join1CI                 ~> sup1CI
  2685     join2CI                 ~> sup2CI
  2686     join1E                  ~> sup1E
  2687     join2E                  ~> sup2E
  2688 
  2689     is_meet_Meet            ~> is_meet_Inf
  2690     Meet_bool_def           ~> Inf_bool_def
  2691     Meet_fun_def            ~> Inf_fun_def
  2692     Meet_greatest           ~> Inf_greatest
  2693     Meet_lower              ~> Inf_lower
  2694     Meet_set_def            ~> Inf_set_def
  2695 
  2696     Sup_def                 ~> Sup_Inf
  2697     Sup_bool_eq             ~> Sup_bool_def
  2698     Sup_fun_eq              ~> Sup_fun_def
  2699     Sup_set_eq              ~> Sup_set_def
  2700 
  2701     listsp_meetI            ~> listsp_infI
  2702     listsp_meet_eq          ~> listsp_inf_eq
  2703 
  2704     meet_min                ~> inf_min
  2705     join_max                ~> sup_max
  2706 
  2707 * Added syntactic class "size"; overloaded constant "size" now has
  2708 type "'a::size ==> bool"
  2709 
  2710 * Internal reorganisation of `size' of datatypes: size theorems
  2711 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2712 simplification rules by default!); theorems "prod.size" now named
  2713 "*.size".
  2714 
  2715 * Class "div" now inherits from class "times" rather than "type".
  2716 INCOMPATIBILITY.
  2717 
  2718 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2719 Linorder etc.  have disappeared; operations defined in terms of
  2720 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2721 
  2722 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2723 
  2724 * HOL-Word: New extensive library and type for generic, fixed size
  2725 machine words, with arithemtic, bit-wise, shifting and rotating
  2726 operations, reflection into int, nat, and bool lists, automation for
  2727 linear arithmetic (by automatic reflection into nat or int), including
  2728 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2729 arithmetic type classes, supporting automatic simplification of
  2730 numerals on all operations.
  2731 
  2732 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2733 
  2734 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2735 
  2736 * Code generator library theories:
  2737   - Code_Integer represents HOL integers by big integer literals in target
  2738     languages.
  2739   - Code_Char represents HOL characters by character literals in target
  2740     languages.
  2741   - Code_Char_chr like Code_Char, but also offers treatment of character
  2742     codes; includes Code_Integer.
  2743   - Executable_Set allows to generate code for finite sets using lists.
  2744   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2745     denominator).
  2746   - Executable_Real implements a subset of real numbers, namly those
  2747     representable by rational numbers.
  2748   - Efficient_Nat implements natural numbers by integers, which in general will
  2749     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2750     includes Code_Integer.
  2751   - Code_Index provides an additional datatype index which is mapped to
  2752     target-language built-in integers.
  2753   - Code_Message provides an additional datatype message_string which is isomorphic to
  2754     strings; messages are mapped to target-language strings.
  2755 
  2756 * New package for inductive predicates
  2757 
  2758   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2759 
  2760     inductive
  2761       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2762       for z_1 :: U_1 and ... and z_n :: U_m
  2763     where
  2764       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2765     | ...
  2766 
  2767   with full support for type-inference, rather than
  2768 
  2769     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2770 
  2771     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2772     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2773 
  2774     inductive "s z_1 ... z_m"
  2775     intros
  2776       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2777       ...
  2778 
  2779   For backward compatibility, there is a wrapper allowing inductive
  2780   sets to be defined with the new package via
  2781 
  2782     inductive_set
  2783       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2784       for z_1 :: U_1 and ... and z_n :: U_m
  2785     where
  2786       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2787     | ...
  2788 
  2789   or
  2790 
  2791     inductive_set
  2792       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2793       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2794       for z_1 :: U_1 and ... and z_n :: U_m
  2795     where
  2796       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2797     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2798     | ...
  2799 
  2800   if the additional syntax "p ..." is required.
  2801 
  2802   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2803   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2804 
  2805   INCOMPATIBILITIES:
  2806 
  2807   - Since declaration and definition of inductive sets or predicates
  2808     is no longer separated, abbreviations involving the newly
  2809     introduced sets or predicates must be specified together with the
  2810     introduction rules after the 'where' keyword (see above), rather
  2811     than before the actual inductive definition.
  2812 
  2813   - The variables in induction and elimination rules are now
  2814     quantified in the order of their occurrence in the introduction
  2815     rules, rather than in alphabetical order. Since this may break
  2816     some proofs, these proofs either have to be repaired, e.g. by
  2817     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2818     statements of the form
  2819 
  2820       case (rule_i a_i_1 ... a_i_{k_i})
  2821 
  2822     or the old order of quantification has to be restored by explicitly adding
  2823     meta-level quantifiers in the introduction rules, i.e.
  2824 
  2825       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2826 
  2827   - The format of the elimination rules is now
  2828 
  2829       p z_1 ... z_m x_1 ... x_n ==>
  2830         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2831         ==> ... ==> P
  2832 
  2833     for predicates and
  2834 
  2835       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2836         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2837         ==> ... ==> P
  2838 
  2839     for sets rather than
  2840 
  2841       x : s z_1 ... z_m ==>
  2842         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2843         ==> ... ==> P
  2844 
  2845     This may require terms in goals to be expanded to n-tuples
  2846     (e.g. using case_tac or simplification with the split_paired_all
  2847     rule) before the above elimination rule is applicable.
  2848 
  2849   - The elimination or case analysis rules for (mutually) inductive
  2850     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2851     list of rules "p_1_..._p_k.elims" is no longer available.
  2852 
  2853 * New package "function"/"fun" for general recursive functions,
  2854 supporting mutual and nested recursion, definitions in local contexts,
  2855 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2856 for small examples, and the separate tutorial on the function
  2857 package. The old recdef "package" is still available as before, but
  2858 users are encouraged to use the new package.
  2859 
  2860 * Method "lexicographic_order" automatically synthesizes termination
  2861 relations as lexicographic combinations of size measures. 
  2862 
  2863 * Case-expressions allow arbitrary constructor-patterns (including
  2864 "_") and take their order into account, like in functional
  2865 programming.  Internally, this is translated into nested
  2866 case-expressions; missing cases are added and mapped to the predefined
  2867 constant "undefined". In complicated cases printing may no longer show
  2868 the original input but the internal form. Lambda-abstractions allow
  2869 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2870 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2871 variable.
  2872 
  2873 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2874 is an abbreviation for "of_nat :: nat => int". The simplification
  2875 rules for "of_nat" have been changed to work like "int" did
  2876 previously.  Potential INCOMPATIBILITY:
  2877   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2878   - of_nat_diff and of_nat_mult are no longer default simp rules
  2879 
  2880 * Method "algebra" solves polynomial equations over (semi)rings using
  2881 Groebner bases. The (semi)ring structure is defined by locales and the
  2882 tool setup depends on that generic context. Installing the method for
  2883 a specific type involves instantiating the locale and possibly adding
  2884 declarations for computation on the coefficients.  The method is
  2885 already instantiated for natural numbers and for the axiomatic class
  2886 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2887 CALCULEMUS 2007 for the general principles underlying this
  2888 architecture of context-aware proof-tools.
  2889 
  2890 * Method "ferrack" implements quantifier elimination over
  2891 special-purpose dense linear orders using locales (analogous to
  2892 "algebra"). The method is already installed for class
  2893 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2894 rat, etc.
  2895 
  2896 * Former constant "List.op @" now named "List.append".  Use ML
  2897 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2898 circumvent possible incompatibilities when working on ML level.
  2899 
  2900 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2901 
  2902 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2903 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2904 
  2905 * New syntax for Haskell-like list comprehension (input only), eg.
  2906 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2907 
  2908 * The special syntax for function "filter" has changed from [x :
  2909 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2910 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2911 
  2912 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2913 defined on nat only, as an abbreviation for [a..<Suc b]
  2914 INCOMPATIBILITY.
  2915 
  2916 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2917 
  2918 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2919 
  2920 * New lemma collection field_simps (an extension of ring_simps) for
  2921 manipulating (in)equations involving division. Multiplies with all
  2922 denominators that can be proved to be non-zero (in equations) or
  2923 positive/negative (in inequations).
  2924 
  2925 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2926 have been improved and renamed to ring_simps, group_simps and
  2927 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2928 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2929 
  2930 * Theory Library/Commutative_Ring: switched from recdef to function
  2931 package; constants add, mul, pow now curried.  Infix syntax for
  2932 algebraic operations.
  2933 
  2934 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2935 INCOMPATIBILITY.
  2936 
  2937 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2938 INCOMPATIBILITY.
  2939 
  2940 * HOL/records: generalised field-update to take a function on the
  2941 field rather than the new value: r(|A := x|) is translated to A_update
  2942 (K x) r The K-combinator that is internally used is called K_record.
  2943 INCOMPATIBILITY: Usage of the plain update functions has to be
  2944 adapted.
  2945  
  2946 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2947 * x = 0, which are required for a semiring.  Richer structures do not
  2948 inherit from semiring_0 anymore, because this property is a theorem
  2949 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2950 there is more to prove, but this is mostly trivial.
  2951 
  2952 * Class "recpower" is generalized to arbitrary monoids, not just
  2953 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2954 commutativity or semiring properties additionally.
  2955 
  2956 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2957 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2958 better use 'abbreviation'.
  2959 
  2960 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2961 
  2962 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2963 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2964 significant changes for setting up numeral syntax for types:
  2965   - New constants Numeral.pred and Numeral.succ instead
  2966       of former Numeral.bin_pred and Numeral.bin_succ.
  2967   - Use integer operations instead of bin_add, bin_mult and so on.
  2968   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2969   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2970 
  2971 See src/HOL/Integ/IntArith.thy for an example setup.
  2972 
  2973 * Command 'normal_form' computes the normal form of a term that may
  2974 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2975 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2976 heavy-duty computations because the functions are compiled to ML
  2977 first.  Correspondingly, a method "normalization" is provided.  See
  2978 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2979 
  2980 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2981 25 like -->); output depends on the "iff" print_mode, the default is
  2982 "A = B" (with priority 50).
  2983 
  2984 * Relations less (<) and less_eq (<=) are also available on type bool.
  2985 Modified syntax to disallow nesting without explicit parentheses,
  2986 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2987 INCOMPATIBILITY.
  2988 
  2989 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2990 
  2991 * Relation composition operator "op O" now has precedence 75 and binds
  2992 stronger than union and intersection. INCOMPATIBILITY.
  2993 
  2994 * The old set interval syntax "{m..n(}" (and relatives) has been
  2995 removed.  Use "{m..<n}" (and relatives) instead.
  2996 
  2997 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2998 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2999 ``declare [[simproc del: neq]]''.
  3000 
  3001 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3002 True/False.
  3003 
  3004 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3005 
  3006 * Theorem setsum_mult renamed to setsum_right_distrib.
  3007 
  3008 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3009 ``rule'' method.
  3010 
  3011 * Reimplemented methods "sat" and "satx", with several improvements:
  3012 goals no longer need to be stated as "<prems> ==> False", equivalences
  3013 (i.e. "=" on type bool) are handled, variable names of the form
  3014 "lit_<n>" are no longer reserved, significant speedup.
  3015 
  3016 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3017 zChaff is still supported as well.
  3018 
  3019 * 'inductive' and 'datatype': provide projections of mutual rules,
  3020 bundled as foo_bar.inducts;
  3021 
  3022 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3023 Library.
  3024 
  3025 * Library: moved theory Accessible_Part to main HOL.
  3026 
  3027 * Library: added theory Coinductive_List of potentially infinite lists
  3028 as greatest fixed-point.
  3029 
  3030 * Library: added theory AssocList which implements (finite) maps as
  3031 association lists.
  3032 
  3033 * Method "evaluation" solves goals (i.e. a boolean expression)
  3034 efficiently by compiling it to ML.  The goal is "proved" (via an
  3035 oracle) if it evaluates to True.
  3036 
  3037 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3038 also when invoked by the simplifier.  This results in the Simplifier
  3039 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3040 Configuration option fast_arith_split_limit=0 recovers the old
  3041 behavior.
  3042 
  3043 * Support for hex (0x20) and binary (0b1001) numerals.
  3044 
  3045 * New method: reify eqs (t), where eqs are equations for an
  3046 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3047 parameter, computes a term s::'b and a list xs::'a list and proves the
  3048 theorem I xs s = t. This is also known as reification or quoting. The
  3049 resulting theorem is applied to the subgoal to substitute t with I xs
  3050 s.  If t is omitted, the subgoal itself is reified.
  3051 
  3052 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3053 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3054 where f is supposed to be a computable function (in the sense of code
  3055 generattion). The method uses reify to compute s and xs as above then
  3056 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3057 r and finally gets the theorem t = r, which is again applied to the
  3058 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3059 
  3060 * Reflection: Automatic reification now handels binding, an example is
  3061 available in src/HOL/ex/ReflectionEx.thy
  3062 
  3063 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3064 command 'statespace' that is similar to 'record', but introduces an
  3065 abstract specification based on the locale infrastructure instead of
  3066 HOL types.  This leads to extra flexibility in composing state spaces,
  3067 in particular multiple inheritance and renaming of components.
  3068 
  3069 
  3070 *** HOL-Complex ***
  3071 
  3072 * Hyperreal: Functions root and sqrt are now defined on negative real
  3073 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3074 Nonnegativity side conditions have been removed from many lemmas, so
  3075 that more subgoals may now be solved by simplification; potential
  3076 INCOMPATIBILITY.
  3077 
  3078 * Real: new type classes formalize real normed vector spaces and
  3079 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3080 and norm :: 'a => real.
  3081 
  3082 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3083 reals into other types. The overloaded constant Reals :: 'a set is now
  3084 defined as range of_real; potential INCOMPATIBILITY.
  3085 
  3086 * Real: proper support for ML code generation, including 'quickcheck'.
  3087 Reals are implemented as arbitrary precision rationals.
  3088 
  3089 * Hyperreal: Several constants that previously worked only for the
  3090 reals have been generalized, so they now work over arbitrary vector
  3091 spaces. Type annotations may need to be added in some cases; potential
  3092 INCOMPATIBILITY.
  3093 
  3094   Infinitesimal  :: ('a::real_normed_vector) star set
  3095   HFinite        :: ('a::real_normed_vector) star set
  3096   HInfinite      :: ('a::real_normed_vector) star set
  3097   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3098   monad          :: ('a::real_normed_vector) star => 'a star set
  3099   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3100   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3101   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3102   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3103   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3104   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3105   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3106   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3107   sgn            :: 'a::real_normed_vector => 'a
  3108   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3109 
  3110 * Complex: Some complex-specific constants are now abbreviations for
  3111 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3112 hnorm.  Other constants have been entirely removed in favor of the
  3113 polymorphic versions (INCOMPATIBILITY):
  3114 
  3115   approx        <-- capprox
  3116   HFinite       <-- CFinite
  3117   HInfinite     <-- CInfinite
  3118   Infinitesimal <-- CInfinitesimal
  3119   monad         <-- cmonad
  3120   galaxy        <-- cgalaxy
  3121   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3122   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3123   (ns)deriv     <-- (ns)cderiv
  3124 
  3125 
  3126 *** HOL-Algebra ***
  3127 
  3128 * Formalisation of ideals and the quotient construction over rings.
  3129 
  3130 * Order and lattice theory no longer based on records.
  3131 INCOMPATIBILITY.
  3132 
  3133 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3134 greatest_closed.  INCOMPATIBILITY.
  3135 
  3136 * Method algebra is now set up via an attribute.  For examples see
  3137 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3138 of algebraic structures.
  3139 
  3140 * Renamed theory CRing to Ring.
  3141 
  3142 
  3143 *** HOL-Nominal ***
  3144 
  3145 * Substantial, yet incomplete support for nominal datatypes (binding
  3146 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3147 src/HOL/Nominal/Examples.  Prospective users should consult
  3148 http://isabelle.in.tum.de/nominal/
  3149 
  3150 
  3151 *** ML ***
  3152 
  3153 * ML basics: just one true type int, which coincides with IntInf.int
  3154 (even on SML/NJ).
  3155 
  3156 * ML within Isar: antiquotations allow to embed statically-checked
  3157 formal entities in the source, referring to the context available at
  3158 compile-time.  For example:
  3159 
  3160 ML {* @{sort "{zero,one}"} *}
  3161 ML {* @{typ "'a => 'b"} *}
  3162 ML {* @{term "%x. x"} *}
  3163 ML {* @{prop "x == y"} *}
  3164 ML {* @{ctyp "'a => 'b"} *}
  3165 ML {* @{cterm "%x. x"} *}
  3166 ML {* @{cprop "x == y"} *}
  3167 ML {* @{thm asm_rl} *}
  3168 ML {* @{thms asm_rl} *}
  3169 ML {* @{type_name c} *}
  3170 ML {* @{type_syntax c} *}
  3171 ML {* @{const_name c} *}
  3172 ML {* @{const_syntax c} *}
  3173 ML {* @{context} *}
  3174 ML {* @{theory} *}
  3175 ML {* @{theory Pure} *}
  3176 ML {* @{theory_ref} *}
  3177 ML {* @{theory_ref Pure} *}
  3178 ML {* @{simpset} *}
  3179 ML {* @{claset} *}
  3180 ML {* @{clasimpset} *}
  3181 
  3182 The same works for sources being ``used'' within an Isar context.
  3183 
  3184 * ML in Isar: improved error reporting; extra verbosity with
  3185 ML_Context.trace enabled.
  3186 
  3187 * Pure/General/table.ML: the join operations now works via exceptions
  3188 DUP/SAME instead of type option. This is simpler in simple cases, and
  3189 admits slightly more efficient complex applications.
  3190 
  3191 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3192 use Context.generic instead of just theory.
  3193 
  3194 * Pure: datatype Context.generic joins theory/Proof.context and
  3195 provides some facilities for code that works in either kind of
  3196 context, notably GenericDataFun for uniform theory and proof data.
  3197 
  3198 * Pure: simplified internal attribute type, which is now always
  3199 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3200 local (Proof.context) attributes have been discontinued, while
  3201 minimizing code duplication. Thm.rule_attribute and
  3202 Thm.declaration_attribute build canonical attributes; see also structure
  3203 Context for further operations on Context.generic, notably
  3204 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3205 declarations and definitions.
  3206 
  3207 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3208 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3209 init only required for impure data. INCOMPATIBILITY: empty really need
  3210 to be empty (no dependencies on theory content!)
  3211 
  3212 * Pure/kernel: consts certification ignores sort constraints given in
  3213 signature declarations. (This information is not relevant to the
  3214 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3215 potential INCOMPATIBILITY.
  3216 
  3217 * Pure: axiomatic type classes are now purely definitional, with
  3218 explicit proofs of class axioms and super class relations performed
  3219 internally. See Pure/axclass.ML for the main internal interfaces --
  3220 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3221 AxClass.axiomatize_class/classrel/arity supersede
  3222 Sign.add_classes/classrel/arities.
  3223 
  3224 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3225 global/local versions on theory vs. Proof.context have been
  3226 discontinued; Attrib.syntax and Method.syntax have been adapted
  3227 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3228 attributes, methods, etc.
  3229 
  3230 * Pure: several functions of signature "... -> theory -> theory * ..."
  3231 have been reoriented to "... -> theory -> ... * theory" in order to
  3232 allow natural usage in combination with the ||>, ||>>, |-> and
  3233 fold_map combinators.
  3234 
  3235 * Pure: official theorem names (closed derivations) and additional
  3236 comments (tags) are now strictly separate.  Name hints -- which are
  3237 maintained as tags -- may be attached any time without affecting the
  3238 derivation.
  3239 
  3240 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3241 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3242 achieve the old behaviour.
  3243 
  3244 * Pure: the "Goal" constant is now called "prop", supporting a
  3245 slightly more general idea of ``protecting'' meta-level rule
  3246 statements.
  3247 
  3248 * Pure: Logic.(un)varify only works in a global context, which is now
  3249 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3250 Logic.legacy_(un)varify as temporary workaround.
  3251 
  3252 * Pure: structure Name provides scalable operations for generating
  3253 internal variable names, notably Name.variants etc.  This replaces
  3254 some popular functions from term.ML:
  3255 
  3256   Term.variant		->  Name.variant
  3257   Term.variantlist	->  Name.variant_list
  3258   Term.invent_names	->  Name.invent_list
  3259 
  3260 Note that low-level renaming rarely occurs in new code -- operations
  3261 from structure Variable are used instead (see below).
  3262 
  3263 * Pure: structure Variable provides fundamental operations for proper
  3264 treatment of fixed/schematic variables in a context.  For example,
  3265 Variable.import introduces fixes for schematics of given facts and
  3266 Variable.export reverses the effect (up to renaming) -- this replaces
  3267 various freeze_thaw operations.
  3268 
  3269 * Pure: structure Goal provides simple interfaces for
  3270 init/conclude/finish and tactical prove operations (replacing former
  3271 Tactic.prove).  Goal.prove is the canonical way to prove results
  3272 within a given context; Goal.prove_global is a degraded version for
  3273 theory level goals, including a global Drule.standard.  Note that
  3274 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3275 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3276 in a locale context).
  3277 
  3278 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3279 and type checking (Syntax.check_term etc.), with common combinations
  3280 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3281 which are considered legacy and await removal.
  3282 
  3283 * Pure/Syntax: generic interfaces for type unchecking
  3284 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3285 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3286 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3287 available for convenience, but refer to the very same operations using
  3288 a mere theory instead of a full context.
  3289 
  3290 * Isar: simplified treatment of user-level errors, using exception
  3291 ERROR of string uniformly.  Function error now merely raises ERROR,
  3292 without any side effect on output channels.  The Isar toplevel takes
  3293 care of proper display of ERROR exceptions.  ML code may use plain
  3294 handle/can/try; cat_error may be used to concatenate errors like this:
  3295 
  3296   ... handle ERROR msg => cat_error msg "..."
  3297 
  3298 Toplevel ML code (run directly or through the Isar toplevel) may be
  3299 embedded into the Isar toplevel with exception display/debug like
  3300 this:
  3301 
  3302   Isar.toplevel (fn () => ...)
  3303 
  3304 INCOMPATIBILITY, removed special transform_error facilities, removed
  3305 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3306 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3307 -- use plain ERROR instead.
  3308 
  3309 * Isar: theory setup now has type (theory -> theory), instead of a
  3310 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3311 
  3312 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3313 ProofContext.debug/verbose flags.
  3314 
  3315 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3316 theory before entering a proof state.  Transactions now always see a
  3317 quasi-functional intermediate checkpoint, both in interactive and
  3318 batch mode.
  3319 
  3320 * Isar: simplified interfaces for outer syntax.  Renamed
  3321 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3322 OuterSyntax.add_parsers -- this functionality is now included in
  3323 OuterSyntax.command etc.  INCOMPATIBILITY.
  3324 
  3325 * Simplifier: the simpset of a running simplification process now
  3326 contains a proof context (cf. Simplifier.the_context), which is the
  3327 very context that the initial simpset has been retrieved from (by
  3328 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3329 (solver, looper etc.) may depend on arbitrary proof data.
  3330 
  3331 * Simplifier.inherit_context inherits the proof context (plus the
  3332 local bounds) of the current simplification process; any simproc
  3333 etc. that calls the Simplifier recursively should do this!  Removed
  3334 former Simplifier.inherit_bounds, which is already included here --
  3335 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3336 specify an explicit context using Simplifier.context/theory_context.
  3337 
  3338 * Simplifier/Classical Reasoner: more abstract interfaces
  3339 change_simpset/claset for modifying the simpset/claset reference of a
  3340 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3341 INCOMPATIBILITY.
  3342 
  3343 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3344 "Trueprop" etc.
  3345 
  3346 
  3347 *** System ***
  3348 
  3349 * settings: the default heap location within ISABELLE_HOME_USER now
  3350 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3351 Isabelle installations.
  3352 
  3353 * isabelle-process: option -S (secure mode) disables some critical
  3354 operations, notably runtime compilation and evaluation of ML source
  3355 code.
  3356 
  3357 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3358 
  3359 * Support for parallel execution, using native multicore support of
  3360 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3361 independent theories, according to the given theory header
  3362 specifications. The maximum number of worker threads is specified via
  3363 usedir option -M or the "max-threads" setting in Proof General. A
  3364 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3365 to 6 on a 8-core machine.  User-code needs to observe certain
  3366 guidelines for thread-safe programming, see appendix A in the Isar
  3367 Implementation manual.
  3368 
  3369 
  3370 
  3371 New in Isabelle2005 (October 2005)
  3372 ----------------------------------
  3373 
  3374 *** General ***
  3375 
  3376 * Theory headers: the new header syntax for Isar theories is
  3377 
  3378   theory <name>
  3379   imports <theory1> ... <theoryN>
  3380   uses <file1> ... <fileM>
  3381   begin
  3382 
  3383 where the 'uses' part is optional.  The previous syntax
  3384 
  3385   theory <name> = <theory1> + ... + <theoryN>:
  3386 
  3387 will disappear in the next release.  Use isatool fixheaders to convert
  3388 existing theory files.  Note that there is no change in ancient
  3389 non-Isar theories now, but these will disappear soon.
  3390 
  3391 * Theory loader: parent theories can now also be referred to via
  3392 relative and absolute paths.
  3393 
  3394 * Command 'find_theorems' searches for a list of criteria instead of a
  3395 list of constants. Known criteria are: intro, elim, dest, name:string,
  3396 simp:term, and any term. Criteria can be preceded by '-' to select
  3397 theorems that do not match. Intro, elim, dest select theorems that
  3398 match the current goal, name:s selects theorems whose fully qualified
  3399 name contain s, and simp:term selects all simplification rules whose
  3400 lhs match term.  Any other term is interpreted as pattern and selects
  3401 all theorems matching the pattern. Available in ProofGeneral under
  3402 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3403 
  3404   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3405 
  3406 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3407 matching the current goal as introduction rule and not having "HOL."
  3408 in their name (i.e. not being defined in theory HOL).
  3409 
  3410 * Command 'thms_containing' has been discontinued in favour of
  3411 'find_theorems'; INCOMPATIBILITY.
  3412 
  3413 * Communication with Proof General is now 8bit clean, which means that
  3414 Unicode text in UTF-8 encoding may be used within theory texts (both
  3415 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3416 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3417 
  3418   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3419   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3420 
  3421 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3422 Classical Reasoner.  Typical big applications run around 2 times
  3423 faster.
  3424 
  3425 
  3426 *** Document preparation ***
  3427 
  3428 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3429 of raw sources.  Only those symbols that do not require additional
  3430 LaTeX packages (depending on comments in isabellesym.sty) are
  3431 displayed properly, everything else is left verbatim.  isatool display
  3432 and isatool print are used as front ends (these are subject to the
  3433 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3434 
  3435 * Command tags control specific markup of certain regions of text,
  3436 notably folding and hiding.  Predefined tags include "theory" (for
  3437 theory begin and end), "proof" for proof commands, and "ML" for
  3438 commands involving ML code; the additional tags "visible" and
  3439 "invisible" are unused by default.  Users may give explicit tag
  3440 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3441 interpretation of tags is determined by the LaTeX job during document
  3442 preparation: see option -V of isatool usedir, or options -n and -t of
  3443 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3444 \isadroptag.
  3445 
  3446 Several document versions may be produced at the same time via isatool
  3447 usedir (the generated index.html will link all of them).  Typical
  3448 specifications include ''-V document=theory,proof,ML'' to present
  3449 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3450 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3451 these parts without any formal replacement text.  The Isabelle site
  3452 default settings produce ''document'' and ''outline'' versions as
  3453 specified above.
  3454 
  3455 * Several new antiquotations:
  3456 
  3457   @{term_type term} prints a term with its type annotated;
  3458 
  3459   @{typeof term} prints the type of a term;
  3460 
  3461   @{const const} is the same as @{term const}, but checks that the
  3462   argument is a known logical constant;
  3463 
  3464   @{term_style style term} and @{thm_style style thm} print a term or
  3465   theorem applying a "style" to it
  3466 
  3467   @{ML text}
  3468 
  3469 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3470 definitions, equations, inequations etc., 'concl' printing only the
  3471 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3472 to print the specified premise.  TermStyle.add_style provides an ML
  3473 interface for introducing further styles.  See also the "LaTeX Sugar"
  3474 document practical applications.  The ML antiquotation prints
  3475 type-checked ML expressions verbatim.
  3476 
  3477 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3478 and 'text' support optional locale specification '(in loc)', which
  3479 specifies the default context for interpreting antiquotations.  For
  3480 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3481 
  3482 * Option 'locale=NAME' of antiquotations specifies an alternative
  3483 context interpreting the subsequent argument.  For example: @{thm
  3484 [locale=lattice] inf_assoc}.
  3485 
  3486 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3487 a proof context.
  3488 
  3489 * Proper output of antiquotations for theory commands involving a
  3490 proof context (such as 'locale' or 'theorem (in loc) ...').
  3491 
  3492 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3493 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3494 
  3495 * isatool usedir: new option -C (default true) controls whether option
  3496 -D should include a copy of the original document directory; -C false
  3497 prevents unwanted effects such as copying of administrative CVS data.
  3498 
  3499 
  3500 *** Pure ***
  3501 
  3502 * Considerably improved version of 'constdefs' command.  Now performs
  3503 automatic type-inference of declared constants; additional support for
  3504 local structure declarations (cf. locales and HOL records), see also
  3505 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3506 sequential dependencies of definitions within a single 'constdefs'
  3507 section; moreover, the declared name needs to be an identifier.  If
  3508 all fails, consider to fall back on 'consts' and 'defs' separately.
  3509 
  3510 * Improved indexed syntax and implicit structures.  First of all,
  3511 indexed syntax provides a notational device for subscripted
  3512 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3513 expressions.  Secondly, in a local context with structure
  3514 declarations, number indexes \<^sub>n or the empty index (default
  3515 number 1) refer to a certain fixed variable implicitly; option
  3516 show_structs controls printing of implicit structures.  Typical
  3517 applications of these concepts involve record types and locales.
  3518 
  3519 * New command 'no_syntax' removes grammar declarations (and
  3520 translations) resulting from the given syntax specification, which is
  3521 interpreted in the same manner as for the 'syntax' command.
  3522 
  3523 * 'Advanced' translation functions (parse_translation etc.) may depend
  3524 on the signature of the theory context being presently used for
  3525 parsing/printing, see also isar-ref manual.
  3526 
  3527 * Improved 'oracle' command provides a type-safe interface to turn an
  3528 ML expression of type theory -> T -> term into a primitive rule of
  3529 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3530 is already included here); see also FOL/ex/IffExample.thy;
  3531 INCOMPATIBILITY.
  3532 
  3533 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3534 before); "cI" is no longer bound, use "c.intro" instead.
  3535 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3536 axclasses vs. locales.
  3537 
  3538 * Improved internal renaming of symbolic identifiers -- attach primes
  3539 instead of base 26 numbers.
  3540 
  3541 * New flag show_question_marks controls printing of leading question
  3542 marks in schematic variable names.
  3543 
  3544 * In schematic variable names, *any* symbol following \<^isub> or
  3545 \<^isup> is now treated as part of the base name.  For example, the
  3546 following works without printing of awkward ".0" indexes:
  3547 
  3548   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3549     by simp
  3550 
  3551 * Inner syntax includes (*(*nested*) comments*).
  3552 
  3553 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3554 annotations as "(00...)".
  3555 
  3556 * Clear separation of logical types and nonterminals, where the latter
  3557 may only occur in 'syntax' specifications or type abbreviations.
  3558 Before that distinction was only partially implemented via type class
  3559 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3560 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3561 exotic syntax specifications may require further adaption
  3562 (e.g. Cube/Cube.thy).
  3563 
  3564 * Removed obsolete type class "logic", use the top sort {} instead.
  3565 Note that non-logical types should be declared as 'nonterminals'
  3566 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3567 specifications.
  3568 
  3569 * Attributes 'induct' and 'cases': type or set names may now be
  3570 locally fixed variables as well.
  3571 
  3572 * Simplifier: can now control the depth to which conditional rewriting
  3573 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3574 Limit.
  3575 
  3576 * Simplifier: simplification procedures may now take the current
  3577 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3578 interface), which is very useful for calling the Simplifier
  3579 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3580 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3581 low-level mk_simproc no longer applies Logic.varify internally, to
  3582 allow for use in a context of fixed variables.
  3583 
  3584 * thin_tac now works even if the assumption being deleted contains !!
  3585 or ==>.  More generally, erule now works even if the major premise of
  3586 the elimination rule contains !! or ==>.
  3587 
  3588 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3589 
  3590 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3591 from Pure, which contains all common declarations already.  Both
  3592 theories are defined via plain Isabelle/Isar .thy files.
  3593 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3594 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3595 use isatool fixcpure to adapt your theory and ML sources.
  3596 
  3597 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3598 selections of theorems in named facts via index ranges.
  3599 
  3600 * 'print_theorems': in theory mode, really print the difference
  3601 wrt. the last state (works for interactive theory development only),
  3602 in proof mode print all local facts (cf. 'print_facts');
  3603 
  3604 * 'hide': option '(open)' hides only base names.
  3605 
  3606 * More efficient treatment of intermediate checkpoints in interactive
  3607 theory development.
  3608 
  3609 * Code generator is now invoked via code_module (incremental code
  3610 generation) and code_library (modular code generation, ML structures
  3611 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3612 must be quoted when used as identifiers.
  3613 
  3614 * New 'value' command for reading, evaluating and printing terms using
  3615 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3616 quoted when used as identifier.
  3617 
  3618 
  3619 *** Locales ***
  3620 
  3621 * New commands for the interpretation of locale expressions in
  3622 theories (1), locales (2) and proof contexts (3).  These generate
  3623 proof obligations from the expression specification.  After the
  3624 obligations have been discharged, theorems of the expression are added
  3625 to the theory, target locale or proof context.  The synopsis of the
  3626 commands is a follows:
  3627 
  3628   (1) interpretation expr inst
  3629   (2) interpretation target < expr
  3630   (3) interpret expr inst
  3631 
  3632 Interpretation in theories and proof contexts require a parameter
  3633 instantiation of terms from the current context.  This is applied to
  3634 specifications and theorems of the interpreted expression.
  3635 Interpretation in locales only permits parameter renaming through the
  3636 locale expression.  Interpretation is smart in that interpretations
  3637 that are active already do not occur in proof obligations, neither are
  3638 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3639 inspect active interpretations of a particular locale.  For details,
  3640 see the Isar Reference manual.  Examples can be found in
  3641 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3642 
  3643 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3644 'interpret' instead.
  3645 
  3646 * New context element 'constrains' for adding type constraints to
  3647 parameters.
  3648 
  3649 * Context expressions: renaming of parameters with syntax
  3650 redeclaration.
  3651 
  3652 * Locale declaration: 'includes' disallowed.
  3653 
  3654 * Proper static binding of attribute syntax -- i.e. types / terms /
  3655 facts mentioned as arguments are always those of the locale definition
  3656 context, independently of the context of later invocations.  Moreover,
  3657 locale operations (renaming and type / term instantiation) are applied
  3658 to attribute arguments as expected.
  3659 
  3660 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3661 actual attributes; rare situations may require Attrib.attribute to
  3662 embed those attributes into Attrib.src that lack concrete syntax.
  3663 Attribute implementations need to cooperate properly with the static
  3664 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3665 Attrib.XXX_thm etc. already do the right thing without further
  3666 intervention.  Only unusual applications -- such as "where" or "of"
  3667 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3668 on the context and the facts involved -- may have to assign parsed
  3669 values to argument tokens explicitly.
  3670 
  3671 * Changed parameter management in theorem generation for long goal
  3672 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3673 theorem statement in rare situations.
  3674 
  3675 * Locale inspection command 'print_locale' omits notes elements.  Use
  3676 'print_locale!' to have them included in the output.
  3677 
  3678 
  3679 *** Provers ***
  3680 
  3681 * Provers/hypsubst.ML: improved version of the subst method, for
  3682 single-step rewriting: it now works in bound variable contexts. New is
  3683 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3684 rewrite a different subterm than the original subst method, which is
  3685 still available as 'simplesubst'.
  3686 
  3687 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3688 and quasi orders.
  3689 
  3690 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3691 reflexive-transitive closure of relations.
  3692 
  3693 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3694 limit (previously hard-coded with a value of 20) user-definable.
  3695 
  3696 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3697 is peformed already.  Object-logics merely need to finish their
  3698 initial simpset configuration as before.  INCOMPATIBILITY.
  3699 
  3700 
  3701 *** HOL ***
  3702 
  3703 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3704 
  3705   syntax (epsilon)
  3706     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3707 
  3708 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3709 and x-symbol; use option '-m epsilon' to get it actually printed.
  3710 Moreover, the mathematically important symbolic identifier \<epsilon>
  3711 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3712 
  3713 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3714 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3715 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3716 support corresponding Isar calculations.
  3717 
  3718 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3719 instead of ":".
  3720 
  3721 * theory SetInterval: changed the syntax for open intervals:
  3722 
  3723   Old       New
  3724   {..n(}    {..<n}
  3725   {)n..}    {n<..}
  3726   {m..n(}   {m..<n}
  3727   {)m..n}   {m<..n}
  3728   {)m..n(}  {m<..<n}
  3729 
  3730 The old syntax is still supported but will disappear in the next
  3731 release.  For conversion use the following Emacs search and replace
  3732 patterns (these are not perfect but work quite well):
  3733 
  3734   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3735   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3736 
  3737 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3738 equalities in commutative rings; method 'algebra' provides a generic
  3739 interface.
  3740 
  3741 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3742 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3743 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3744 be a tuple pattern.
  3745 
  3746 Some new syntax forms are available:
  3747 
  3748   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3749   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3750   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3751   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3752 
  3753 The latter form "\<Sum>x < k. e" used to be based on a separate
  3754 function "Summation", which has been discontinued.
  3755 
  3756 * theory Finite_Set: in structured induction proofs, the insert case
  3757 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3758 (insert F x)'.
  3759 
  3760 * The 'refute' command has been extended to support a much larger
  3761 fragment of HOL, including axiomatic type classes, constdefs and
  3762 typedefs, inductive datatypes and recursion.
  3763 
  3764 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3765 Requires zChaff with proof generation to be installed.  See
  3766 HOL/ex/SAT_Examples.thy for examples.
  3767 
  3768 * Datatype induction via method 'induct' now preserves the name of the
  3769 induction variable. For example, when proving P(xs::'a list) by
  3770 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3771 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3772 in unstructured proof scripts.
  3773 
  3774 * Reworked implementation of records.  Improved scalability for
  3775 records with many fields, avoiding performance problems for type
  3776 inference. Records are no longer composed of nested field types, but
  3777 of nested extension types. Therefore the record type only grows linear
  3778 in the number of extensions and not in the number of fields.  The
  3779 top-level (users) view on records is preserved.  Potential
  3780 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3781 old record representation. The type generated for a record is called
  3782 <record_name>_ext_type.
  3783 
  3784 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3785 proofs triggered by a record definition or a simproc (if
  3786 quick_and_dirty is enabled).  Definitions of large records can take
  3787 quite long.
  3788 
  3789 New simproc record_upd_simproc for simplification of multiple record
  3790 updates enabled by default.  Moreover, trivial updates are also
  3791 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3792 occasionally, since simplification is more powerful by default.
  3793 
  3794 * typedef: proper support for polymorphic sets, which contain extra
  3795 type-variables in the term.
  3796 
  3797 * Simplifier: automatically reasons about transitivity chains
  3798 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3799 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3800 old proofs break occasionally as simplification may now solve more
  3801 goals than previously.
  3802 
  3803 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3804 present.  Works for all partial orders (class "order"), in particular
  3805 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3806 just like y <= x.
  3807 
  3808 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3809 bound variable or a constant then the let is unfolded.  Otherwise
  3810 first a is simplified to b, and then f b is simplified to g. If
  3811 possible we abstract b from g arriving at "let x = b in h x",
  3812 otherwise we unfold the let and arrive at g.  The simproc can be
  3813 enabled/disabled by the reference use_let_simproc.  Potential
  3814 INCOMPATIBILITY since simplification is more powerful by default.
  3815 
  3816 * Classical reasoning: the meson method now accepts theorems as arguments.
  3817 
  3818 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3819 jobs to provide advice on the provability of subgoals.
  3820 
  3821 * Theory OrderedGroup and Ring_and_Field: various additions and
  3822 improvements to faciliate calculations involving equalities and
  3823 inequalities.
  3824 
  3825 The following theorems have been eliminated or modified
  3826 (INCOMPATIBILITY):
  3827 
  3828   abs_eq             now named abs_of_nonneg
  3829   abs_of_ge_0        now named abs_of_nonneg
  3830   abs_minus_eq       now named abs_of_nonpos
  3831   imp_abs_id         now named abs_of_nonneg
  3832   imp_abs_neg_id     now named abs_of_nonpos
  3833   mult_pos           now named mult_pos_pos
  3834   mult_pos_le        now named mult_nonneg_nonneg
  3835   mult_pos_neg_le    now named mult_nonneg_nonpos
  3836   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3837   mult_neg           now named mult_neg_neg
  3838   mult_neg_le        now named mult_nonpos_nonpos
  3839 
  3840 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3841      
  3842      zero_le_square
  3843      not_square_less_zero 
  3844 
  3845   The following lemmas have been deleted from Real/RealPow:
  3846   
  3847      realpow_zero_zero
  3848      realpow_two
  3849      realpow_less
  3850      zero_le_power
  3851      realpow_two_le
  3852      abs_realpow_two
  3853      realpow_two_abs     
  3854 
  3855 * Theory Parity: added rules for simplifying exponents.
  3856 
  3857 * Theory List:
  3858 
  3859 The following theorems have been eliminated or modified
  3860 (INCOMPATIBILITY):
  3861 
  3862   list_all_Nil       now named list_all.simps(1)
  3863   list_all_Cons      now named list_all.simps(2)
  3864   list_all_conv      now named list_all_iff
  3865   set_mem_eq         now named mem_iff
  3866 
  3867 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3868 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3869 
  3870 
  3871 *** HOL-Complex ***
  3872 
  3873 * Theory RealDef: better support for embedding natural numbers and
  3874 integers in the reals.
  3875 
  3876 The following theorems have been eliminated or modified
  3877 (INCOMPATIBILITY):
  3878 
  3879   exp_ge_add_one_self  now requires no hypotheses
  3880   real_of_int_add      reversed direction of equality (use [symmetric])
  3881   real_of_int_minus    reversed direction of equality (use [symmetric])
  3882   real_of_int_diff     reversed direction of equality (use [symmetric])
  3883   real_of_int_mult     reversed direction of equality (use [symmetric])
  3884 
  3885 * Theory RComplete: expanded support for floor and ceiling functions.
  3886 
  3887 * Theory Ln is new, with properties of the natural logarithm
  3888 
  3889 * Hyperreal: There is a new type constructor "star" for making
  3890 nonstandard types.  The old type names are now type synonyms:
  3891 
  3892   hypreal = real star
  3893   hypnat = nat star
  3894   hcomplex = complex star
  3895 
  3896 * Hyperreal: Many groups of similarly-defined constants have been
  3897 replaced by polymorphic versions (INCOMPATIBILITY):
  3898 
  3899   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3900 
  3901   starset      <-- starsetNat, starsetC
  3902   *s*          <-- *sNat*, *sc*
  3903   starset_n    <-- starsetNat_n, starsetC_n
  3904   *sn*         <-- *sNatn*, *scn*
  3905   InternalSets <-- InternalNatSets, InternalCSets
  3906 
  3907   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3908   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3909   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3910   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3911   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3912 
  3913 * Hyperreal: Many type-specific theorems have been removed in favor of
  3914 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3915 
  3916   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3917   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3918   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3919   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3920   right_minus <-- hypreal_add_minus
  3921   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3922   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3923   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3924   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3925   mult_1_right <-- hcomplex_mult_one_right
  3926   mult_zero_left <-- hcomplex_mult_zero_left
  3927   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3928   right_distrib <-- hypnat_add_mult_distrib2
  3929   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3930   right_inverse <-- hypreal_mult_inverse
  3931   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3932   order_refl <-- {hypreal,hypnat}_le_refl
  3933   order_trans <-- {hypreal,hypnat}_le_trans
  3934   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3935   order_less_le <-- {hypreal,hypnat}_less_le
  3936   linorder_linear <-- {hypreal,hypnat}_le_linear
  3937   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3938   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3939   add_nonneg_nonneg <-- hypreal_le_add_order
  3940 
  3941 * Hyperreal: Separate theorems having to do with type-specific
  3942 versions of constants have been merged into theorems that apply to the
  3943 new polymorphic constants (INCOMPATIBILITY):
  3944 
  3945   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3946   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3947   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3948   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3949   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3950   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3951   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3952   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3953   STAR_diff <-- {STAR,STARC}_diff
  3954   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3955     STARC_hcomplex_of_complex}_image_subset
  3956   starset_n_Un <-- starset{Nat,C}_n_Un
  3957   starset_n_Int <-- starset{Nat,C}_n_Int
  3958   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3959   starset_n_diff <-- starset{Nat,C}_n_diff
  3960   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3961   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3962   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3963   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3964   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3965   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3966   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3967   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3968   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3969   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3970   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3971   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3972   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3973   starfun_diff <-- starfun{C,RC,CR}_diff
  3974   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3975   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3976   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3977   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3978   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3979   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3980   starfun_Id <-- starfunC_Id
  3981   starfun_approx <-- starfun{Nat,CR}_approx
  3982   starfun_capprox <-- starfun{C,RC}_capprox
  3983   starfun_abs <-- starfunNat_rabs
  3984   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3985   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3986   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3987   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3988   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3989   starfun_add_approx <-- starfunCR_add_approx
  3990   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3991   starfun_divide <-- starfun{C,CR,RC}_divide
  3992   starfun_n <-- starfun{Nat,C}_n
  3993   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3994   starfun_n_add <-- starfun{Nat,C}_n_add
  3995   starfun_n_add_minus <-- starfunNat_n_add_minus
  3996   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3997   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3998   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3999 
  4000   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4001   star_n_minus <-- {hypreal,hcomplex}_minus
  4002   star_n_diff <-- {hypreal,hcomplex}_diff
  4003   star_n_mult <-- {hypreal,hcomplex}_mult
  4004   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4005   star_n_le <-- {hypreal,hypnat}_le
  4006   star_n_less <-- {hypreal,hypnat}_less
  4007   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4008   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4009   star_n_abs <-- hypreal_hrabs
  4010   star_n_divide <-- hcomplex_divide
  4011 
  4012   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4013   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4014   star_of_diff <-- hypreal_of_real_diff
  4015   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4016   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4017   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4018   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4019   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4020   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4021   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4022   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4023   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4024   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4025   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4026   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4027   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4028   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4029   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4030   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4031   star_of_power <-- hypreal_of_real_power
  4032   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4033 
  4034 * Hyperreal: new method "transfer" that implements the transfer
  4035 principle of nonstandard analysis. With a subgoal that mentions
  4036 nonstandard types like "'a star", the command "apply transfer"
  4037 replaces it with an equivalent one that mentions only standard types.
  4038 To be successful, all free variables must have standard types; non-
  4039 standard variables must have explicit universal quantifiers.
  4040 
  4041 * Hyperreal: A theory of Taylor series.
  4042 
  4043 
  4044 *** HOLCF ***
  4045 
  4046 * Discontinued special version of 'constdefs' (which used to support
  4047 continuous functions) in favor of the general Pure one with full
  4048 type-inference.
  4049 
  4050 * New simplification procedure for solving continuity conditions; it
  4051 is much faster on terms with many nested lambda abstractions (cubic
  4052 instead of exponential time).
  4053 
  4054 * New syntax for domain package: selector names are now optional.
  4055 Parentheses should be omitted unless argument is lazy, for example:
  4056 
  4057   domain 'a stream = cons "'a" (lazy "'a stream")
  4058 
  4059 * New command 'fixrec' for defining recursive functions with pattern
  4060 matching; defining multiple functions with mutual recursion is also
  4061 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4062 sinr, or any data constructor defined by the domain package. The given
  4063 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4064 syntax and examples.
  4065 
  4066 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4067 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4068 but the proof obligation additionally includes an admissibility
  4069 requirement. The packages generate instances of class cpo or pcpo,
  4070 with continuity and strictness theorems for Rep and Abs.
  4071 
  4072 * HOLCF: Many theorems have been renamed according to a more standard naming
  4073 scheme (INCOMPATIBILITY):
  4074 
  4075   foo_inject:  "foo$x = foo$y ==> x = y"
  4076   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4077   foo_less:    "(foo$x << foo$y) = (x << y)"
  4078   foo_strict:  "foo$UU = UU"
  4079   foo_defined: "... ==> foo$x ~= UU"
  4080   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4081 
  4082 
  4083 *** ZF ***
  4084 
  4085 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4086 including the First Isomorphism Theorem (on quotienting by the kernel
  4087 of a homomorphism).
  4088 
  4089 * ZF/Simplifier: install second copy of type solver that actually
  4090 makes use of TC rules declared to Isar proof contexts (or locales);
  4091 the old version is still required for ML proof scripts.
  4092 
  4093 
  4094 *** Cube ***
  4095 
  4096 * Converted to Isar theory format; use locales instead of axiomatic
  4097 theories.
  4098 
  4099 
  4100 *** ML ***
  4101 
  4102 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4103 for ||>, ||>>, |>>,
  4104 
  4105 * Pure/library.ML no longer defines its own option datatype, but uses
  4106 that of the SML basis, which has constructors NONE and SOME instead of
  4107 None and Some, as well as exception Option.Option instead of OPTION.
  4108 The functions the, if_none, is_some, is_none have been adapted
  4109 accordingly, while Option.map replaces apsome.
  4110 
  4111 * Pure/library.ML: the exception LIST has been given up in favour of
  4112 the standard exceptions Empty and Subscript, as well as
  4113 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4114 superceded by the standard hd and tl functions etc.
  4115 
  4116 A number of basic list functions are no longer exported to the ML
  4117 toplevel, as they are variants of predefined functions.  The following
  4118 suggests how one can translate existing code:
  4119 
  4120     rev_append xs ys = List.revAppend (xs, ys)
  4121     nth_elem (i, xs) = List.nth (xs, i)
  4122     last_elem xs = List.last xs
  4123     flat xss = List.concat xss
  4124     seq fs = List.app fs
  4125     partition P xs = List.partition P xs
  4126     mapfilter f xs = List.mapPartial f xs
  4127 
  4128 * Pure/library.ML: several combinators for linear functional
  4129 transformations, notably reverse application and composition:
  4130 
  4131   x |> f                f #> g
  4132   (x, y) |-> f          f #-> g
  4133 
  4134 * Pure/library.ML: introduced/changed precedence of infix operators:
  4135 
  4136   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4137   infix 2 ?;
  4138   infix 3 o oo ooo oooo;
  4139   infix 4 ~~ upto downto;
  4140 
  4141 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4142 infix operators.
  4143 
  4144 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4145 fold_map support linear functional transformations and nesting.  For
  4146 example:
  4147 
  4148   fold f [x1, ..., xN] y =
  4149     y |> f x1 |> ... |> f xN
  4150 
  4151   (fold o fold) f [xs1, ..., xsN] y =
  4152     y |> fold f xs1 |> ... |> fold f xsN
  4153 
  4154   fold f [x1, ..., xN] =
  4155     f x1 #> ... #> f xN
  4156 
  4157   (fold o fold) f [xs1, ..., xsN] =
  4158     fold f xs1 #> ... #> fold f xsN
  4159 
  4160 * Pure/library.ML: the following selectors on type 'a option are
  4161 available:
  4162 
  4163   the:               'a option -> 'a  (*partial*)
  4164   these:             'a option -> 'a  where 'a = 'b list
  4165   the_default: 'a -> 'a option -> 'a
  4166   the_list:          'a option -> 'a list
  4167 
  4168 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4169 basic operations for association lists, following natural argument
  4170 order; moreover the explicit equality predicate passed here avoids
  4171 potentially expensive polymorphic runtime equality checks.
  4172 The old functions may be expressed as follows:
  4173 
  4174   assoc = uncurry (AList.lookup (op =))
  4175   assocs = these oo AList.lookup (op =)
  4176   overwrite = uncurry (AList.update (op =)) o swap
  4177 
  4178 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4179 
  4180   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4181   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4182 
  4183 replacing make_keylist and keyfilter (occassionally used)
  4184 Naive rewrites:
  4185 
  4186   make_keylist = AList.make
  4187   keyfilter = AList.find (op =)
  4188 
  4189 * eq_fst and eq_snd now take explicit equality parameter, thus
  4190   avoiding eqtypes. Naive rewrites:
  4191 
  4192     eq_fst = eq_fst (op =)
  4193     eq_snd = eq_snd (op =)
  4194 
  4195 * Removed deprecated apl and apr (rarely used).
  4196   Naive rewrites:
  4197 
  4198     apl (n, op) =>>= curry op n
  4199     apr (op, m) =>>= fn n => op (n, m)
  4200 
  4201 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4202 provides a reasonably efficient light-weight implementation of sets as
  4203 lists.
  4204 
  4205 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4206 few new operations; existing lookup and update are now curried to
  4207 follow natural argument order (for use with fold etc.);
  4208 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4209 
  4210 * Pure/General: output via the Isabelle channels of
  4211 writeln/warning/error etc. is now passed through Output.output, with a
  4212 hook for arbitrary transformations depending on the print_mode
  4213 (cf. Output.add_mode -- the first active mode that provides a output
  4214 function wins).  Already formatted output may be embedded into further
  4215 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4216 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4217 accommodate easy composition of diagnostic messages etc.  Programmers
  4218 rarely need to care about Output.output or Output.raw at all, with
  4219 some notable exceptions: Output.output is required when bypassing the
  4220 standard channels (writeln etc.), or in token translations to produce
  4221 properly formatted results; Output.raw is required when capturing
  4222 already output material that will eventually be presented to the user
  4223 a second time.  For the default print mode, both Output.output and
  4224 Output.raw have no effect.
  4225 
  4226 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4227 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4228 cumulative results are displayed at the end of a batch session.
  4229 
  4230 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4231 replaced by File.platform_path and File.shell_path (with appropriate
  4232 hooks).  This provides a clean interface for unusual systems where the
  4233 internal and external process view of file names are different.
  4234 
  4235 * Pure: more efficient orders for basic syntactic entities: added
  4236 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4237 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4238 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4239 orders now -- potential INCOMPATIBILITY for code that depends on a
  4240 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4241 Library.sort_strings on result).
  4242 
  4243 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4244 fold_types traverse types/terms from left to right, observing natural
  4245 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4246 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4247 
  4248 * Pure: name spaces have been refined, with significant changes of the
  4249 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4250 to extern(_table).  The plain name entry path is superceded by a
  4251 general 'naming' context, which also includes the 'policy' to produce
  4252 a fully qualified name and external accesses of a fully qualified
  4253 name; NameSpace.extend is superceded by context dependent
  4254 Sign.declare_name.  Several theory and proof context operations modify
  4255 the naming context.  Especially note Theory.restore_naming and
  4256 ProofContext.restore_naming to get back to a sane state; note that
  4257 Theory.add_path is no longer sufficient to recover from
  4258 Theory.absolute_path in particular.
  4259 
  4260 * Pure: new flags short_names (default false) and unique_names
  4261 (default true) for controlling output of qualified names.  If
  4262 short_names is set, names are printed unqualified.  If unique_names is
  4263 reset, the name prefix is reduced to the minimum required to achieve
  4264 the original result when interning again, even if there is an overlap
  4265 with earlier declarations.
  4266 
  4267 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4268 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4269 (useful for printing error messages).  INCOMPATIBILITY.
  4270 
  4271 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4272 Theory.theory are now identified, referring to the universal
  4273 Context.theory (see Pure/context.ML).  Actual signature and theory
  4274 content is managed as theory data.  The old code and interfaces were
  4275 spread over many files and structures; the new arrangement introduces
  4276 considerable INCOMPATIBILITY to gain more clarity:
  4277 
  4278   Context -- theory management operations (name, identity, inclusion,
  4279     parents, ancestors, merge, etc.), plus generic theory data;
  4280 
  4281   Sign -- logical signature and syntax operations (declaring consts,
  4282     types, etc.), plus certify/read for common entities;
  4283 
  4284   Theory -- logical theory operations (stating axioms, definitions,
  4285     oracles), plus a copy of logical signature operations (consts,
  4286     types, etc.); also a few basic management operations (Theory.copy,
  4287     Theory.merge, etc.)
  4288 
  4289 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4290 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4291 for convenience -- they merely return the theory.
  4292 
  4293 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4294 
  4295 * Pure: the Isar proof context type is already defined early in Pure
  4296 as Context.proof (note that ProofContext.context and Proof.context are
  4297 aliases, where the latter is the preferred name).  This enables other
  4298 Isabelle components to refer to that type even before Isar is present.
  4299 
  4300 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4301 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4302 any of these kinds.  For example, Sign.intern typeK is now
  4303 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4304 Theory.hide_types.  Also note that former
  4305 Theory.hide_classes/types/consts are now
  4306 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4307 internalize their arguments!  INCOMPATIBILITY.
  4308 
  4309 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4310 datatype thmref (with constructors Name and NameSelection) instead of
  4311 plain string -- INCOMPATIBILITY;
  4312 
  4313 * Pure: cases produced by proof methods specify options, where NONE
  4314 means to remove case bindings -- INCOMPATIBILITY in
  4315 (RAW_)METHOD_CASES.
  4316 
  4317 * Pure: the following operations retrieve axioms or theorems from a
  4318 theory node or theory hierarchy, respectively:
  4319 
  4320   Theory.axioms_of: theory -> (string * term) list
  4321   Theory.all_axioms_of: theory -> (string * term) list
  4322   PureThy.thms_of: theory -> (string * thm) list
  4323   PureThy.all_thms_of: theory -> (string * thm) list
  4324 
  4325 * Pure: print_tac now outputs the goal through the trace channel.
  4326 
  4327 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4328 Reference Toplevel.debug (default false) controls detailed printing
  4329 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4330 controls execution profiling -- set to 1 for time and 2 for space
  4331 (both increase the runtime).
  4332 
  4333 * Isar session: The initial use of ROOT.ML is now always timed,
  4334 i.e. the log will show the actual process times, in contrast to the
  4335 elapsed wall-clock time that the outer shell wrapper produces.
  4336 
  4337 * Simplifier: improved handling of bound variables (nameless
  4338 representation, avoid allocating new strings).  Simprocs that invoke
  4339 the Simplifier recursively should use Simplifier.inherit_bounds to
  4340 avoid local name clashes.  Failure to do so produces warnings
  4341 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4342 for further details.
  4343 
  4344 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4345 bindings for all theorems stored within a given theory; this may help
  4346 in porting non-Isar theories to Isar ones, while keeping ML proof
  4347 scripts for the time being.
  4348 
  4349 * ML operator HTML.with_charset specifies the charset begin used for
  4350 generated HTML files.  For example:
  4351 
  4352   HTML.with_charset "utf-8" use_thy "Hebrew";
  4353   HTML.with_charset "utf-8" use_thy "Chinese";
  4354 
  4355 
  4356 *** System ***
  4357 
  4358 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4359 isabelle, isatool etc.).
  4360 
  4361 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4362 isatool doc, isatool mkdir, display_drafts etc.).
  4363 
  4364 * isatool usedir: option -f allows specification of the ML file to be
  4365 used by Isabelle; default is ROOT.ML.
  4366 
  4367 * New isatool version outputs the version identifier of the Isabelle
  4368 distribution being used.
  4369 
  4370 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4371 (containing Boolean satisfiability problems) into Isabelle/HOL
  4372 theories.
  4373 
  4374 
  4375 
  4376 New in Isabelle2004 (April 2004)
  4377 --------------------------------
  4378 
  4379 *** General ***
  4380 
  4381 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4382   Replaces linorder.ML.
  4383 
  4384 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4385   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4386   (\<a>...\<z>), are now considered normal letters, and can therefore
  4387   be used anywhere where an ASCII letter (a...zA...Z) has until
  4388   now. COMPATIBILITY: This obviously changes the parsing of some
  4389   terms, especially where a symbol has been used as a binder, say
  4390   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4391   as an identifier.  Fix it by inserting a space around former
  4392   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4393   existing theory and ML files.
  4394 
  4395 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4396 
  4397 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4398   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4399   a normal (but invisible) letter. For multiple letter subscripts repeat
  4400   \<^isub> like this: x\<^isub>1\<^isub>2.
  4401 
  4402 * Pure: There are now sub-/superscripts that can span more than one
  4403   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4404   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4405   superscript. The new control characters are not identifier parts.
  4406 
  4407 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4408   content of "..." to the latex file instead of \isacntrl... . The "..."
  4409   may consist of any printable characters excluding the end bracket >.
  4410 
  4411 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4412   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4413   declare constants "final", which prevents their being given a definition
  4414   later.  It is useful for constants whose behaviour is fixed axiomatically
  4415   rather than definitionally, such as the meta-logic connectives.
  4416 
  4417 * Pure: 'instance' now handles general arities with general sorts
  4418   (i.e. intersections of classes),
  4419 
  4420 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4421   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4422   It can be changed to alter the colors/layout of generated pages.
  4423 
  4424 
  4425 *** Isar ***
  4426 
  4427 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4428   cut_tac, subgoal_tac and thin_tac:
  4429   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4430     locales are no longer forced to write Isar proof scripts.
  4431     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4432     emulations.
  4433   - INCOMPATIBILITY: names of variables to be instantiated may no
  4434     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4435     This is consistent with the instantiation attribute "where".
  4436 
  4437 * Attributes "where" and "of":
  4438   - Now take type variables of instantiated theorem into account when reading
  4439     the instantiation string.  This fixes a bug that caused instantiated
  4440     theorems to have too special types in some circumstances.
  4441   - "where" permits explicit instantiations of type variables.
  4442 
  4443 * Calculation commands "moreover" and "also" no longer interfere with
  4444   current facts ("this"), admitting arbitrary combinations with "then"
  4445   and derived forms.
  4446 
  4447 * Locales:
  4448   - Goal statements involving the context element "includes" no longer
  4449     generate theorems with internal delta predicates (those ending on
  4450     "_axioms") in the premise.
  4451     Resolve particular premise with <locale>.intro to obtain old form.
  4452   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4453     specification and "includes" elements in goal statement.
  4454   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4455     [intro?] and [elim?] (respectively) by default.
  4456   - Experimental command for instantiation of locales in proof contexts:
  4457         instantiate <label>[<attrs>]: <loc>
  4458     Instantiates locale <loc> and adds all its theorems to the current context
  4459     taking into account their attributes.  Label and attrs are optional
  4460     modifiers, like in theorem declarations.  If present, names of
  4461     instantiated theorems are qualified with <label>, and the attributes
  4462     <attrs> are applied after any attributes these theorems might have already.
  4463       If the locale has assumptions, a chained fact of the form
  4464     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4465     are derived.  The command does not support old-style locales declared
  4466     with "locale (open)".
  4467       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4468 
  4469 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4470   (Isar) contexts.
  4471 
  4472 
  4473 *** HOL ***
  4474 
  4475 * Proof import: new image HOL4 contains the imported library from
  4476   the HOL4 system with about 2500 theorems. It is imported by
  4477   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4478   can be used like any other Isabelle image.  See
  4479   HOL/Import/HOL/README for more information.
  4480 
  4481 * Simplifier:
  4482   - Much improved handling of linear and partial orders.
  4483     Reasoners for linear and partial orders are set up for type classes
  4484     "linorder" and "order" respectively, and are added to the default simpset
  4485     as solvers.  This means that the simplifier can build transitivity chains
  4486     to solve goals from the assumptions.
  4487   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4488     of blast or auto after simplification become unnecessary because the goal
  4489     is solved by simplification already.
  4490 
  4491 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4492     all proved in axiomatic type classes for semirings, rings and fields.
  4493 
  4494 * Numerics:
  4495   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4496     now formalized using the Ring_and_Field theory mentioned above.
  4497   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4498     than before, because now they are set up once in a generic manner.
  4499   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4500     Look for the general versions in Ring_and_Field (and Power if they concern
  4501     exponentiation).
  4502 
  4503 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4504 
  4505 * Records:
  4506   - Record types are now by default printed with their type abbreviation
  4507     instead of the list of all field types. This can be configured via
  4508     the reference "print_record_type_abbr".
  4509   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4510     (not enabled by default).
  4511   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4512     EX x. x = sel r to True (not enabled by default).
  4513   - Tactic "record_split_simp_tac" to split and simplify records added.
  4514 
  4515 * 'specification' command added, allowing for definition by
  4516   specification.  There is also an 'ax_specification' command that
  4517   introduces the new constants axiomatically.
  4518 
  4519 * arith(_tac) is now able to generate counterexamples for reals as well.
  4520 
  4521 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4522 
  4523 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4524   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4525 
  4526 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4527   matrix theory to linear programming.
  4528 
  4529 * Unions and Intersections:
  4530   The latex output syntax of UN and INT has been changed
  4531   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4532   i.e. the index formulae has become a subscript.
  4533   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4534 
  4535 * Unions and Intersections over Intervals:
  4536   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4537   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4538   like in normal math, and corresponding versions for < and for intersection.
  4539 
  4540 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4541   lexicographic dictonary ordering has been added as "lexord".
  4542 
  4543 * ML: the legacy theory structures Int and List have been removed. They had
  4544   conflicted with ML Basis Library structures having the same names.
  4545 
  4546 * 'refute' command added to search for (finite) countermodels.  Only works
  4547   for a fragment of HOL.  The installation of an external SAT solver is
  4548   highly recommended.  See "HOL/Refute.thy" for details.
  4549 
  4550 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4551   formulae under an assignment of free variables to random values.
  4552   In contrast to 'refute', it can deal with inductive datatypes,
  4553   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4554   for examples.
  4555 
  4556 
  4557 *** HOLCF ***
  4558 
  4559 * Streams now come with concatenation and are part of the HOLCF image
  4560 
  4561 
  4562 
  4563 New in Isabelle2003 (May 2003)
  4564 ------------------------------
  4565 
  4566 *** General ***
  4567 
  4568 * Provers/simplifier:
  4569 
  4570   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4571     Assumptions are now subject to complete mutual simplification,
  4572     not just from left to right. The simplifier now preserves
  4573     the order of assumptions.
  4574 
  4575     Potential INCOMPATIBILITY:
  4576 
  4577     -- simp sometimes diverges where the old version did
  4578        not, e.g. invoking simp on the goal
  4579 
  4580         [| P (f x); y = x; f x = f y |] ==> Q
  4581 
  4582        now gives rise to the infinite reduction sequence
  4583 
  4584         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4585 
  4586        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4587        kind of problem.
  4588 
  4589     -- Tactics combining classical reasoner and simplification (such as auto)
  4590        are also affected by this change, because many of them rely on
  4591        simp. They may sometimes diverge as well or yield a different numbers
  4592        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4593        in case of problems. Sometimes subsequent calls to the classical
  4594        reasoner will fail because a preceeding call to the simplifier too
  4595        eagerly simplified the goal, e.g. deleted redundant premises.
  4596 
  4597   - The simplifier trace now shows the names of the applied rewrite rules
  4598 
  4599   - You can limit the number of recursive invocations of the simplifier
  4600     during conditional rewriting (where the simplifie tries to solve the
  4601     conditions before applying the rewrite rule):
  4602     ML "simp_depth_limit := n"
  4603     where n is an integer. Thus you can force termination where previously
  4604     the simplifier would diverge.
  4605 
  4606   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4607 
  4608   - No longer aborts on failed congruence proof.  Instead, the
  4609     congruence is ignored.
  4610 
  4611 * Pure: New generic framework for extracting programs from constructive
  4612   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4613   as HOL/Extraction for some case studies.
  4614 
  4615 * Pure: The main goal of the proof state is no longer shown by default, only
  4616 the subgoals. This behaviour is controlled by a new flag.
  4617    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4618 (ML: Proof.show_main_goal).
  4619 
  4620 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4621 rules whose conclusion matches subgoal 1:
  4622       PG menu: Isabelle/Isar -> Show me -> matching rules
  4623 The rules are ordered by how closely they match the subgoal.
  4624 In particular, rules that solve a subgoal outright are displayed first
  4625 (or rather last, the way they are printed).
  4626 (ML: ProofGeneral.print_intros())
  4627 
  4628 * Pure: New flag trace_unify_fail causes unification to print
  4629 diagnostic information (PG: in trace buffer) when it fails. This is
  4630 useful for figuring out why single step proofs like rule, erule or
  4631 assumption failed.
  4632 
  4633 * Pure: Locale specifications now produce predicate definitions
  4634 according to the body of text (covering assumptions modulo local
  4635 definitions); predicate "loc_axioms" covers newly introduced text,
  4636 while "loc" is cumulative wrt. all included locale expressions; the
  4637 latter view is presented only on export into the global theory
  4638 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4639 on the old view without predicates;
  4640 
  4641 * Pure: predefined locales "var" and "struct" are useful for sharing
  4642 parameters (as in CASL, for example); just specify something like
  4643 ``var x + var y + struct M'' as import;
  4644 
  4645 * Pure: improved thms_containing: proper indexing of facts instead of
  4646 raw theorems; check validity of results wrt. current name space;
  4647 include local facts of proof configuration (also covers active
  4648 locales), cover fixed variables in index; may use "_" in term
  4649 specification; an optional limit for the number of printed facts may
  4650 be given (the default is 40);
  4651 
  4652 * Pure: disallow duplicate fact bindings within new-style theory files
  4653 (batch-mode only);
  4654 
  4655 * Provers: improved induct method: assumptions introduced by case
  4656 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4657 the goal statement); "foo" still refers to all facts collectively;
  4658 
  4659 * Provers: the function blast.overloaded has been removed: all constants
  4660 are regarded as potentially overloaded, which improves robustness in exchange
  4661 for slight decrease in efficiency;
  4662 
  4663 * Provers/linorder: New generic prover for transitivity reasoning over
  4664 linear orders.  Note: this prover is not efficient!
  4665 
  4666 * Isar: preview of problems to finish 'show' now produce an error
  4667 rather than just a warning (in interactive mode);
  4668 
  4669 
  4670 *** HOL ***
  4671 
  4672 * arith(_tac)
  4673 
  4674  - Produces a counter example if it cannot prove a goal.
  4675    Note that the counter example may be spurious if the goal is not a formula
  4676    of quantifier-free linear arithmetic.
  4677    In ProofGeneral the counter example appears in the trace buffer.
  4678 
  4679  - Knows about div k and mod k where k is a numeral of type nat or int.
  4680 
  4681  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4682    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4683    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4684 
  4685 * simp's arithmetic capabilities have been enhanced a bit: it now
  4686 takes ~= in premises into account (by performing a case split);
  4687 
  4688 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4689 are distributed over a sum of terms;
  4690 
  4691 * New tactic "trans_tac" and method "trans" instantiate
  4692 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4693 "<=", "<" and "=").
  4694 
  4695 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4696 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4697 
  4698 * 'typedef' command has new option "open" to suppress the set
  4699 definition;
  4700 
  4701 * functions Min and Max on finite sets have been introduced (theory
  4702 Finite_Set);
  4703 
  4704 * attribute [symmetric] now works for relations as well; it turns
  4705 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4706 
  4707 * induct over a !!-quantified statement (say !!x1..xn):
  4708   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4709 
  4710 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4711 %x. None. Warning: empty_def now refers to the previously hidden definition
  4712 of the empty set.
  4713 
  4714 * Algebra: formalization of classical algebra.  Intended as base for
  4715 any algebraic development in Isabelle.  Currently covers group theory
  4716 (up to Sylow's theorem) and ring theory (Universal Property of
  4717 Univariate Polynomials).  Contributions welcome;
  4718 
  4719 * GroupTheory: deleted, since its material has been moved to Algebra;
  4720 
  4721 * Complex: new directory of the complex numbers with numeric constants,
  4722 nonstandard complex numbers, and some complex analysis, standard and
  4723 nonstandard (Jacques Fleuriot);
  4724 
  4725 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4726 
  4727 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4728 Fleuriot);
  4729 
  4730 * Real/HahnBanach: updated and adapted to locales;
  4731 
  4732 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4733 Gray and Kramer);
  4734 
  4735 * UNITY: added the Meier-Sanders theory of progress sets;
  4736 
  4737 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4738 as abstract algorithms, instantiated to the JVM;
  4739 
  4740 * Bali: Java source language formalization. Type system, operational
  4741 semantics, axiomatic semantics. Supported language features:
  4742 classes, interfaces, objects,virtual methods, static methods,
  4743 static/instance fields, arrays, access modifiers, definite
  4744 assignment, exceptions.
  4745 
  4746 
  4747 *** ZF ***
  4748 
  4749 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4750 universe, etc.);
  4751 
  4752 * Main ZF: virtually all theories converted to new-style format;
  4753 
  4754 
  4755 *** ML ***
  4756 
  4757 * Pure: Tactic.prove provides sane interface for internal proofs;
  4758 omits the infamous "standard" operation, so this is more appropriate
  4759 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4760 
  4761 * Pure: improved error reporting of simprocs;
  4762 
  4763 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4764 up simprocs;
  4765 
  4766 
  4767 *** Document preparation ***
  4768 
  4769 * uses \par instead of \\ for line breaks in theory text. This may
  4770 shift some page breaks in large documents. To get the old behaviour
  4771 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4772 
  4773 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4774 other packages
  4775 
  4776 * \<euro> now needs package babel/greek instead of marvosym (which
  4777 broke \Rightarrow)
  4778 
  4779 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4780 textcomp package)
  4781 
  4782 
  4783 
  4784 New in Isabelle2002 (March 2002)
  4785 --------------------------------
  4786 
  4787 *** Document preparation ***
  4788 
  4789 * greatly simplified document preparation setup, including more
  4790 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4791 instructive isatool mkdir; users should basically be able to get
  4792 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4793 users may run a separate document processing stage manually like this:
  4794 "isatool usedir -D output HOL Test && isatool document Test/output";
  4795 
  4796 * theory dependency graph may now be incorporated into documents;
  4797 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4798 with \includegraphics of LaTeX;
  4799 
  4800 * proper spacing of consecutive markup elements, especially text
  4801 blocks after section headings;
  4802 
  4803 * support bold style (for single symbols only), input syntax is like
  4804 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4805 
  4806 * \<bullet> is now output as bold \cdot by default, which looks much
  4807 better in printed text;
  4808 
  4809 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4810 note that these symbols are currently unavailable in Proof General /
  4811 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4812 
  4813 * isatool latex no longer depends on changed TEXINPUTS, instead
  4814 isatool document copies the Isabelle style files to the target
  4815 location;
  4816 
  4817 
  4818 *** Isar ***
  4819 
  4820 * Pure/Provers: improved proof by cases and induction;
  4821   - 'case' command admits impromptu naming of parameters (such as
  4822     "case (Suc n)");
  4823   - 'induct' method divinates rule instantiation from the inductive
  4824     claim; no longer requires excessive ?P bindings for proper
  4825     instantiation of cases;
  4826   - 'induct' method properly enumerates all possibilities of set/type
  4827     rules; as a consequence facts may be also passed through *type*
  4828     rules without further ado;
  4829   - 'induct' method now derives symbolic cases from the *rulified*
  4830     rule (before it used to rulify cases stemming from the internal
  4831     atomized version); this means that the context of a non-atomic
  4832     statement becomes is included in the hypothesis, avoiding the
  4833     slightly cumbersome show "PROP ?case" form;
  4834   - 'induct' may now use elim-style induction rules without chaining
  4835     facts, using ``missing'' premises from the goal state; this allows
  4836     rules stemming from inductive sets to be applied in unstructured
  4837     scripts, while still benefitting from proper handling of non-atomic
  4838     statements; NB: major inductive premises need to be put first, all
  4839     the rest of the goal is passed through the induction;
  4840   - 'induct' proper support for mutual induction involving non-atomic
  4841     rule statements (uses the new concept of simultaneous goals, see
  4842     below);
  4843   - append all possible rule selections, but only use the first
  4844     success (no backtracking);
  4845   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4846   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4847   - added 'print_induct_rules' (covered by help item in recent Proof
  4848     General versions);
  4849   - moved induct/cases attributes to Pure, methods to Provers;
  4850   - generic method setup instantiated for FOL and HOL;
  4851 
  4852 * Pure: support multiple simultaneous goal statements, for example
  4853 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4854 meta-level mechanism, this acts as if several individual goals had
  4855 been stated separately; in particular common proof methods need to be
  4856 repeated in order to cover all claims; note that a single elimination
  4857 step is *not* sufficient to establish the two conjunctions, so this
  4858 fails:
  4859 
  4860   assume "A & B" then have A and B ..   (*".." fails*)
  4861 
  4862 better use "obtain" in situations as above; alternative refer to
  4863 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4864 
  4865 * Pure: proper integration with ``locales''; unlike the original
  4866 version by Florian Kammller, Isar locales package high-level proof
  4867 contexts rather than raw logical ones (e.g. we admit to include
  4868 attributes everywhere); operations on locales include merge and
  4869 rename; support for implicit arguments (``structures''); simultaneous
  4870 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4871 some examples;
  4872 
  4873 * Pure: the following commands have been ``localized'', supporting a
  4874 target locale specification "(in name)": 'lemma', 'theorem',
  4875 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4876 stored both within the locale and at the theory level (exported and
  4877 qualified by the locale name);
  4878 
  4879 * Pure: theory goals may now be specified in ``long'' form, with
  4880 ad-hoc contexts consisting of arbitrary locale elements. for example
  4881 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4882 definitions may be given, too); the result is a meta-level rule with
  4883 the context elements being discharged in the obvious way;
  4884 
  4885 * Pure: new proof command 'using' allows to augment currently used
  4886 facts after a goal statement ('using' is syntactically analogous to
  4887 'apply', but acts on the goal's facts only); this allows chained facts
  4888 to be separated into parts given before and after a claim, as in
  4889 ``from a and b have C using d and e <proof>'';
  4890 
  4891 * Pure: renamed "antecedent" case to "rule_context";
  4892 
  4893 * Pure: new 'judgment' command records explicit information about the
  4894 object-logic embedding (used by several tools internally); no longer
  4895 use hard-wired "Trueprop";
  4896 
  4897 * Pure: added 'corollary' command;
  4898 
  4899 * Pure: fixed 'token_translation' command;
  4900 
  4901 * Pure: removed obsolete 'exported' attribute;
  4902 
  4903 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4904 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4905 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4906 
  4907 * Pure: method 'atomize' presents local goal premises as object-level
  4908 statements (atomic meta-level propositions); setup controlled via
  4909 rewrite rules declarations of 'atomize' attribute; example
  4910 application: 'induct' method with proper rule statements in improper
  4911 proof *scripts*;
  4912 
  4913 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4914 now consider the syntactic context of assumptions, giving a better
  4915 chance to get type-inference of the arguments right (this is
  4916 especially important for locales);
  4917 
  4918 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4919 mode;
  4920 
  4921 * Pure/obtain: the formal conclusion "thesis", being marked as
  4922 ``internal'', may no longer be reference directly in the text;
  4923 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4924 situations;
  4925 
  4926 * Pure: generic 'sym' attribute which declares a rule both as pure
  4927 'elim?' and for the 'symmetric' operation;
  4928 
  4929 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4930 text; the fixed correlation with particular command syntax has been
  4931 discontinued;
  4932 
  4933 * Pure: new method 'rules' is particularly well-suited for proof
  4934 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4935 but often produces more compact proof terms with less detours;
  4936 
  4937 * Pure/Provers/classical: simplified integration with pure rule
  4938 attributes and methods; the classical "intro?/elim?/dest?"
  4939 declarations coincide with the pure ones; the "rule" method no longer
  4940 includes classically swapped intros; "intro" and "elim" methods no
  4941 longer pick rules from the context; also got rid of ML declarations
  4942 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4943 INCOMPATIBILITY;
  4944 
  4945 * Provers/classical: attribute 'swapped' produces classical inversions
  4946 of introduction rules;
  4947 
  4948 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4949 rules instead of full simplifier context; 'iff' attribute handles
  4950 conditional rules;
  4951 
  4952 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4953 
  4954 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4955 "(permissive)" option to recover old behavior;
  4956 
  4957 * HOL: 'inductive' no longer features separate (collective) attributes
  4958 for 'intros' (was found too confusing);
  4959 
  4960 * HOL: properly declared induction rules less_induct and
  4961 wf_induct_rule;
  4962 
  4963 
  4964 *** HOL ***
  4965 
  4966 * HOL: moved over to sane numeral syntax; the new policy is as
  4967 follows:
  4968 
  4969   - 0 and 1 are polymorphic constants, which are defined on any
  4970   numeric type (nat, int, real etc.);
  4971 
  4972   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4973   binary representation internally;
  4974 
  4975   - type nat has special constructor Suc, and generally prefers Suc 0
  4976   over 1::nat and Suc (Suc 0) over 2::nat;
  4977 
  4978 This change may cause significant problems of INCOMPATIBILITY; here
  4979 are some hints on converting existing sources:
  4980 
  4981   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4982   entities, so expressions involving "-" (unary or binary minus) need
  4983   to be spaced properly;
  4984 
  4985   - existing occurrences of "1" may need to be constraint "1::nat" or
  4986   even replaced by Suc 0; similar for old "2";
  4987 
  4988   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4989 
  4990   - remove all special provisions on numerals in proofs;
  4991 
  4992 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4993 representation (depends on bin_arith_simps in the default context);
  4994 
  4995 * HOL: symbolic syntax for x^2 (numeral 2);
  4996 
  4997 * HOL: the class of all HOL types is now called "type" rather than
  4998 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4999 in axclass/classes, instance/arities, and (usually rare) occurrences
  5000 in typings (of consts etc.); internally the class is called
  5001 "HOL.type", ML programs should refer to HOLogic.typeS;
  5002 
  5003 * HOL/record package improvements:
  5004   - new derived operations "fields" to build a partial record section,
  5005     "extend" to promote a fixed record to a record scheme, and
  5006     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5007     declared as simp by default;
  5008   - shared operations ("more", "fields", etc.) now need to be always
  5009     qualified) --- potential INCOMPATIBILITY;
  5010   - removed "make_scheme" operations (use "make" with "extend") --
  5011     INCOMPATIBILITY;
  5012   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5013   - provides cases/induct rules for use with corresponding Isar
  5014     methods (for concrete records, record schemes, concrete more
  5015     parts, and schematic more parts -- in that order);
  5016   - internal definitions directly based on a light-weight abstract
  5017     theory of product types over typedef rather than datatype;
  5018 
  5019 * HOL: generic code generator for generating executable ML code from
  5020 specifications; specific support for HOL constructs such as inductive
  5021 datatypes and sets, as well as recursive functions; can be invoked
  5022 via 'generate_code' theory section;
  5023 
  5024 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5025 
  5026 * HOL: consolidated and renamed several theories.  In particular:
  5027         Ord.thy has been absorbed into HOL.thy
  5028         String.thy has been absorbed into List.thy
  5029 
  5030 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5031 (beware of argument permutation!);
  5032 
  5033 * HOL: linorder_less_split superseded by linorder_cases;
  5034 
  5035 * HOL/List: "nodups" renamed to "distinct";
  5036 
  5037 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5038 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5039   - Ex_def has changed, now need to use some_eq_ex
  5040 
  5041 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5042 in this (rare) case use:
  5043 
  5044   delSWrapper "split_all_tac"
  5045   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5046 
  5047 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5048 MAY FAIL;
  5049 
  5050 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5051 Isabelle's type classes, ^ on functions and relations has too general
  5052 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5053 necessary to attach explicit type constraints;
  5054 
  5055 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5056 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5057 renamed accordingly (eg "compI" -> "rel_compI").
  5058 
  5059 * HOL: syntax translations now work properly with numerals and records
  5060 expressions;
  5061 
  5062 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5063 of "lam" -- INCOMPATIBILITY;
  5064 
  5065 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5066 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5067 renamed "Product_Type.unit";
  5068 
  5069 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5070 
  5071 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5072 the "cases" method);
  5073 
  5074 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5075 Florian Kammller);
  5076 
  5077 * HOL/IMP: updated and converted to new-style theory format; several
  5078 parts turned into readable document, with proper Isar proof texts and
  5079 some explanations (by Gerwin Klein);
  5080 
  5081 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5082 
  5083 * HOL-Hyperreal is now a logic image;
  5084 
  5085 
  5086 *** HOLCF ***
  5087 
  5088 * Isar: consts/constdefs supports mixfix syntax for continuous
  5089 operations;
  5090 
  5091 * Isar: domain package adapted to new-style theory format, e.g. see
  5092 HOLCF/ex/Dnat.thy;
  5093 
  5094 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5095 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5096 lift.induct_tac, always use UU instead of Undef;
  5097 
  5098 * HOLCF/IMP: updated and converted to new-style theory;
  5099 
  5100 
  5101 *** ZF ***
  5102 
  5103 * Isar: proper integration of logic-specific tools and packages,
  5104 including theory commands '(co)inductive', '(co)datatype',
  5105 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5106 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5107 
  5108 * theory Main no longer includes AC; for the Axiom of Choice, base
  5109 your theory on Main_ZFC;
  5110 
  5111 * the integer library now covers quotients and remainders, with many
  5112 laws relating division to addition, multiplication, etc.;
  5113 
  5114 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5115 typeless version of the formalism;
  5116 
  5117 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5118 format;
  5119 
  5120 * ZF/Induct: new directory for examples of inductive definitions,
  5121 including theory Multiset for multiset orderings; converted to
  5122 new-style theory format;
  5123 
  5124 * ZF: many new theorems about lists, ordinals, etc.;
  5125 
  5126 
  5127 *** General ***
  5128 
  5129 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5130 variable proof controls level of detail: 0 = no proofs (only oracle
  5131 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5132 also ref manual for further ML interfaces;
  5133 
  5134 * Pure/axclass: removed obsolete ML interface
  5135 goal_subclass/goal_arity;
  5136 
  5137 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5138 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5139 separate tokens, so expressions involving minus need to be spaced
  5140 properly;
  5141 
  5142 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5143 rather than "infixl" or "infixr";
  5144 
  5145 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5146 sort constraint specifications in type inference; e.g. "x::_::foo"
  5147 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5148 type variable);
  5149 
  5150 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5151 control output of nested => (types); the default behavior is
  5152 "type_brackets";
  5153 
  5154 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5155 tokens into AST constants;
  5156 
  5157 * Pure/syntax: prefer later declarations of translations and print
  5158 translation functions; potential INCOMPATIBILITY: need to reverse
  5159 multiple declarations for same syntax element constant;
  5160 
  5161 * Pure/show_hyps reset by default (in accordance to existing Isar
  5162 practice);
  5163 
  5164 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5165 addSafter;
  5166 
  5167 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5168 as well;
  5169 
  5170 * system: tested support for MacOS X; should be able to get Isabelle +
  5171 Proof General to work in a plain Terminal after installing Poly/ML
  5172 (e.g. from the Isabelle distribution area) and GNU bash alone
  5173 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5174 support requires further installations, e.g. from
  5175 http://fink.sourceforge.net/);
  5176 
  5177 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5178 
  5179 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5180 of 40 MB), cf. ML_OPTIONS;
  5181 
  5182 * system: Proof General keywords specification is now part of the
  5183 Isabelle distribution (see etc/isar-keywords.el);
  5184 
  5185 * system: support for persistent Proof General sessions (refrain from
  5186 outdating all loaded theories on startup); user may create writable
  5187 logic images like this: ``isabelle -q HOL Test'';
  5188 
  5189 * system: smart selection of Isabelle process versus Isabelle
  5190 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5191 run both "isabelle" and "Isabelle" even if file names are badly
  5192 damaged (executable inspects the case of the first letter of its own
  5193 name); added separate "isabelle-process" and "isabelle-interface";
  5194 
  5195 * system: refrain from any attempt at filtering input streams; no
  5196 longer support ``8bit'' encoding of old isabelle font, instead proper
  5197 iso-latin characters may now be used; the related isatools
  5198 "symbolinput" and "nonascii" have disappeared as well;
  5199 
  5200 * system: removed old "xterm" interface (the print modes "xterm" and
  5201 "xterm_color" are still available for direct use in a suitable
  5202 terminal);
  5203 
  5204 
  5205 
  5206 New in Isabelle99-2 (February 2001)
  5207 -----------------------------------
  5208 
  5209 *** Overview of INCOMPATIBILITIES ***
  5210 
  5211 * HOL: please note that theories in the Library and elsewhere often use the
  5212 new-style (Isar) format; to refer to their theorems in an ML script you must
  5213 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5214 
  5215 * HOL: inductive package no longer splits induction rule aggressively,
  5216 but only as far as specified by the introductions given; the old
  5217 format may be recovered via ML function complete_split_rule or attribute
  5218 'split_rule (complete)';
  5219 
  5220 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5221 gfp_Tarski to gfp_unfold;
  5222 
  5223 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5224 
  5225 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5226 relation); infix "^^" has been renamed "``"; infix "``" has been
  5227 renamed "`"; "univalent" has been renamed "single_valued";
  5228 
  5229 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5230 operation;
  5231 
  5232 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5233 
  5234 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5235 
  5236 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5237 consequence, it is no longer monotonic wrt. the local goal context
  5238 (which is now passed through the inductive cases);
  5239 
  5240 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5241 \<gg> to \<ggreater>;
  5242 
  5243 
  5244 *** Document preparation ***
  5245 
  5246 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5247 available: are "it" for near math-mode best-style output, "sl" for
  5248 slanted text style, and "tt" for plain type-writer; if no
  5249 \isabellestyle command is given, output is according to slanted
  5250 type-writer);
  5251 
  5252 * support sub/super scripts (for single symbols only), input syntax is
  5253 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5254 
  5255 * some more standard symbols; see Appendix A of the system manual for
  5256 the complete list of symbols defined in isabellesym.sty;
  5257 
  5258 * improved isabelle style files; more abstract symbol implementation
  5259 (should now use \isamath{...} and \isatext{...} in custom symbol
  5260 definitions);
  5261 
  5262 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5263 state; Note that presentation of goal states does not conform to
  5264 actual human-readable proof documents.  Please do not include goal
  5265 states into document output unless you really know what you are doing!
  5266 
  5267 * proper indentation of antiquoted output with proportional LaTeX
  5268 fonts;
  5269 
  5270 * no_document ML operator temporarily disables LaTeX document
  5271 generation;
  5272 
  5273 * isatool unsymbolize tunes sources for plain ASCII communication;
  5274 
  5275 
  5276 *** Isar ***
  5277 
  5278 * Pure: Isar now suffers initial goal statements to contain unbound
  5279 schematic variables (this does not conform to actual readable proof
  5280 documents, due to unpredictable outcome and non-compositional proof
  5281 checking); users who know what they are doing may use schematic goals
  5282 for Prolog-style synthesis of proven results;
  5283 
  5284 * Pure: assumption method (an implicit finishing) now handles actual
  5285 rules as well;
  5286 
  5287 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5288 initial goal, declare "that" only as Pure intro (only for single
  5289 steps); the "that" rule assumption may now be involved in implicit
  5290 finishing, thus ".." becomes a feasible for trivial obtains;
  5291 
  5292 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5293 instance proofs may be performed by "..";
  5294 
  5295 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5296 statements as well;
  5297 
  5298 * Pure: more robust selection of calculational rules;
  5299 
  5300 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5301 rule (as well as the assumption rule);
  5302 
  5303 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5304 lemmas, using the graph browser tool;
  5305 
  5306 * Pure: predict failure of "show" in interactive mode;
  5307 
  5308 * Pure: 'thms_containing' now takes actual terms as arguments;
  5309 
  5310 * HOL: improved method 'induct' --- now handles non-atomic goals
  5311 (potential INCOMPATIBILITY); tuned error handling;
  5312 
  5313 * HOL: cases and induct rules now provide explicit hints about the
  5314 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5315 any remaining facts are inserted into the goal verbatim;
  5316 
  5317 * HOL: local contexts (aka cases) may now contain term bindings as
  5318 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5319 the result to be shown in each case;
  5320 
  5321 * HOL: added 'recdef_tc' command;
  5322 
  5323 * isatool convert assists in eliminating legacy ML scripts;
  5324 
  5325 
  5326 *** HOL ***
  5327 
  5328 * HOL/Library: a collection of generic theories to be used together
  5329 with main HOL; the theory loader path already includes this directory
  5330 by default; the following existing theories have been moved here:
  5331 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5332 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5333 
  5334 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5335 modelling and verification task performed in Isabelle/HOL +
  5336 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5337 
  5338 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5339 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5340 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5341 'domain', this makes the theory consistent with mathematical
  5342 literature;
  5343 
  5344 * HOL basics: added overloaded operations "inverse" and "divide"
  5345 (infix "/"), syntax for generic "abs" operation, generic summation
  5346 operator \<Sum>;
  5347 
  5348 * HOL/typedef: simplified package, provide more useful rules (see also
  5349 HOL/subset.thy);
  5350 
  5351 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5352 now expressed as a proper nested rule (old-style tactic scripts may
  5353 require atomize_strip_tac to cope with non-atomic premises);
  5354 
  5355 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5356 to "split_conv" (old name still available for compatibility);
  5357 
  5358 * HOL: improved concrete syntax for strings (e.g. allows translation
  5359 rules with string literals);
  5360 
  5361 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5362  and Fleuriot's mechanization of analysis, including the transcendental
  5363  functions for the reals;
  5364 
  5365 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5366 
  5367 
  5368 *** CTT ***
  5369 
  5370 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5371 "lam" is displayed as TWO lambda-symbols
  5372 
  5373 * CTT: theory Main now available, containing everything (that is, Bool
  5374 and Arith);
  5375 
  5376 
  5377 *** General ***
  5378 
  5379 * Pure: the Simplifier has been implemented properly as a derived rule
  5380 outside of the actual kernel (at last!); the overall performance
  5381 penalty in practical applications is about 50%, while reliability of
  5382 the Isabelle inference kernel has been greatly improved;
  5383 
  5384 * print modes "brackets" and "no_brackets" control output of nested =>
  5385 (types) and ==> (props); the default behaviour is "brackets";
  5386 
  5387 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5388 as assumptions as well;
  5389 
  5390 * system: support Poly/ML 4.0;
  5391 
  5392 * system: isatool install handles KDE version 1 or 2;
  5393 
  5394 
  5395 
  5396 New in Isabelle99-1 (October 2000)
  5397 ----------------------------------
  5398 
  5399 *** Overview of INCOMPATIBILITIES ***
  5400 
  5401 * HOL: simplification of natural numbers is much changed; to partly
  5402 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5403 issue the following ML commands:
  5404 
  5405   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5406   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5407 
  5408 * HOL: simplification no longer dives into case-expressions; this is
  5409 controlled by "t.weak_case_cong" for each datatype t;
  5410 
  5411 * HOL: nat_less_induct renamed to less_induct;
  5412 
  5413 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5414 fixsome to patch .thy and .ML sources automatically;
  5415 
  5416   select_equality  -> some_equality
  5417   select_eq_Ex     -> some_eq_ex
  5418   selectI2EX       -> someI2_ex
  5419   selectI2         -> someI2
  5420   selectI          -> someI
  5421   select1_equality -> some1_equality
  5422   Eps_sym_eq       -> some_sym_eq_trivial
  5423   Eps_eq           -> some_eq_trivial
  5424 
  5425 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5426 
  5427 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5428 instead);
  5429 
  5430 * HOL: the recursion equations generated by 'recdef' are now called
  5431 f.simps instead of f.rules;
  5432 
  5433 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5434 
  5435 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5436 sometimes be needed;
  5437 
  5438 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5439 
  5440 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5441 
  5442 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5443 product is now "<*>" instead of "Times"; the lexicographic product is
  5444 now "<*lex*>" instead of "**";
  5445 
  5446 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5447 of main HOL, but was unused); better use HOL's datatype package;
  5448 
  5449 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5450 the old syntax may be recovered as follows:
  5451 
  5452   syntax (symbols)
  5453     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5454       (infixl "\\<oplus>" 100)
  5455 
  5456 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5457 
  5458 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5459 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5460 internally;
  5461 
  5462 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5463 changed from A/r to A//r;
  5464 
  5465 * ZF: new treatment of arithmetic (nat & int) may break some old
  5466 proofs;
  5467 
  5468 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5469 rulify -> rule_format, elimify -> elim_format, ...);
  5470 
  5471 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5472 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5473 should have to change intro!! to intro? only); replaced "delrule" by
  5474 "rule del";
  5475 
  5476 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5477 
  5478 * Provers: strengthened force_tac by using new first_best_tac;
  5479 
  5480 * LaTeX document preparation: several changes of isabelle.sty (see
  5481 lib/texinputs);
  5482 
  5483 
  5484 *** Document preparation ***
  5485 
  5486 * formal comments (text blocks etc.) in new-style theories may now
  5487 contain antiquotations of thm/prop/term/typ/text to be presented
  5488 according to latex print mode; concrete syntax is like this:
  5489 @{term[show_types] "f(x) = a + x"};
  5490 
  5491 * isatool mkdir provides easy setup of Isabelle session directories,
  5492 including proper document sources;
  5493 
  5494 * generated LaTeX sources are now deleted after successful run
  5495 (isatool document -c); may retain a copy somewhere else via -D option
  5496 of isatool usedir;
  5497 
  5498 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5499 style files, achieving self-contained LaTeX sources and simplifying
  5500 LaTeX debugging;
  5501 
  5502 * old-style theories now produce (crude) LaTeX output as well;
  5503 
  5504 * browser info session directories are now self-contained (may be put
  5505 on WWW server seperately); improved graphs of nested sessions; removed
  5506 graph for 'all sessions';
  5507 
  5508 * several improvements in isabelle style files; \isabellestyle{it}
  5509 produces fake math mode output; \isamarkupheader is now \section by
  5510 default; see lib/texinputs/isabelle.sty etc.;
  5511 
  5512 
  5513 *** Isar ***
  5514 
  5515 * Isar/Pure: local results and corresponding term bindings are now
  5516 subject to Hindley-Milner polymorphism (similar to ML); this
  5517 accommodates incremental type-inference very nicely;
  5518 
  5519 * Isar/Pure: new derived language element 'obtain' supports
  5520 generalized existence reasoning;
  5521 
  5522 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5523 support accumulation of results, without applying any rules yet;
  5524 useful to collect intermediate results without explicit name
  5525 references, and for use with transitivity rules with more than 2
  5526 premises;
  5527 
  5528 * Isar/Pure: scalable support for case-analysis type proofs: new
  5529 'case' language element refers to local contexts symbolically, as
  5530 produced by certain proof methods; internally, case names are attached
  5531 to theorems as "tags";
  5532 
  5533 * Isar/Pure: theory command 'hide' removes declarations from
  5534 class/type/const name spaces;
  5535 
  5536 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5537 indicate potential overloading;
  5538 
  5539 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5540 
  5541 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5542 "{a,b,c}" instead of {a,b,c};
  5543 
  5544 * Isar/Pure now provides its own version of intro/elim/dest
  5545 attributes; useful for building new logics, but beware of confusion
  5546 with the version in Provers/classical;
  5547 
  5548 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5549 case name 'antecedent';
  5550 
  5551 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5552 to the current context is now done automatically);
  5553 
  5554 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5555 for definining proof methods in ML;
  5556 
  5557 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5558 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5559 most cases, one should have to change intro!! to intro? only);
  5560 replaced "delrule" by "rule del";
  5561 
  5562 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5563 'symmetric' attribute (the latter supercedes [RS sym]);
  5564 
  5565 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5566 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5567 well (including splits);
  5568 
  5569 * Isar/Provers: Simplifier and Classical methods now support all kind
  5570 of modifiers used in the past, including 'cong', 'iff', etc.
  5571 
  5572 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5573 of Simplifier and Classical reasoner);
  5574 
  5575 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5576 now support named cases; major packages (inductive, datatype, primrec,
  5577 recdef) support case names and properly name parameters;
  5578 
  5579 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5580 monotonicity conditions are extracted to be proven at end of
  5581 calculations;
  5582 
  5583 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5584 method anyway;
  5585 
  5586 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5587 split_if split_if_asm; datatype package provides theorems foo.splits =
  5588 foo.split foo.split_asm for each datatype;
  5589 
  5590 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5591 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5592 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5593 use "(cases (simplified))" method in proper proof texts);
  5594 
  5595 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5596 
  5597 * Isar: names of theorems etc. may be natural numbers as well;
  5598 
  5599 * Isar: 'pr' command: optional arguments for goals_limit and
  5600 ProofContext.prems_limit; no longer prints theory contexts, but only
  5601 proof states;
  5602 
  5603 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5604 additional print modes to be specified; e.g. "pr(latex)" will print
  5605 proof state according to the Isabelle LaTeX style;
  5606 
  5607 * Isar: improved support for emulating tactic scripts, including proof
  5608 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5609 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5610 (for HOL datatypes);
  5611 
  5612 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5613 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5614 'proof method scripts' have to be in depth-first order;
  5615 
  5616 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5617 
  5618 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5619 should instead use individual commands for printing items
  5620 (print_commands, print_methods etc.);
  5621 
  5622 * Isar: added 'nothing' --- the empty list of theorems;
  5623 
  5624 
  5625 *** HOL ***
  5626 
  5627 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5628 corresponding virtual machine and a specification of its bytecode
  5629 verifier and a lightweight bytecode verifier, including proofs of
  5630 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5631 Cornelia Pusch (see also the homepage of project Bali at
  5632 http://isabelle.in.tum.de/Bali/);
  5633 
  5634 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5635 Clemens Ballarin;
  5636 
  5637 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5638 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5639 Rasmussen;
  5640 
  5641 * HOL/Lattice: fundamental concepts of lattice theory and order
  5642 structures, including duals, properties of bounds versus algebraic
  5643 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5644 Theorem for complete lattices etc.; may also serve as a demonstration
  5645 for abstract algebraic reasoning using axiomatic type classes, and
  5646 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5647 
  5648 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5649 von Oheimb;
  5650 
  5651 * HOL/IMPP: extension of IMP with local variables and mutually
  5652 recursive procedures, by David von Oheimb;
  5653 
  5654 * HOL/Lambda: converted into new-style theory and document;
  5655 
  5656 * HOL/ex/Multiquote: example of multiple nested quotations and
  5657 anti-quotations -- basically a generalized version of de-Bruijn
  5658 representation; very useful in avoiding lifting of operations;
  5659 
  5660 * HOL/record: added general record equality rule to simpset; fixed
  5661 select-update simplification procedure to handle extended records as
  5662 well; admit "r" as field name;
  5663 
  5664 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5665 other numeric types and also as the identity of groups, rings, etc.;
  5666 
  5667 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5668 Types nat and int belong to this axclass;
  5669 
  5670 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5671    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5672    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5673   two terms #m*u and #n*u are replaced by #(m+n)*u
  5674     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5675   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5676     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5677 
  5678 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5679 powerful prover for predicate logic but knows nothing of clasets; see
  5680 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5681 
  5682 * HOL: new version of "case_tac" subsumes both boolean case split and
  5683 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5684 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5685 
  5686 * HOL: simplification no longer dives into case-expressions: only the
  5687 selector expression is simplified, but not the remaining arms; to
  5688 enable full simplification of case-expressions for datatype t, you may
  5689 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5690 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5691 
  5692 * HOL/recdef: the recursion equations generated by 'recdef' for
  5693 function 'f' are now called f.simps instead of f.rules; if all
  5694 termination conditions are proved automatically, these simplification
  5695 rules are added to the simpset, as in primrec; rules may be named
  5696 individually as well, resulting in a separate list of theorems for
  5697 each equation;
  5698 
  5699 * HOL/While is a new theory that provides a while-combinator. It
  5700 permits the definition of tail-recursive functions without the
  5701 provision of a termination measure. The latter is necessary once the
  5702 invariant proof rule for while is applied.
  5703 
  5704 * HOL: new (overloaded) notation for the set of elements below/above
  5705 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5706 
  5707 * HOL: theorems impI, allI, ballI bound as "strip";
  5708 
  5709 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5710 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5711 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5712 
  5713 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5714 
  5715 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5716 main HOL, but was unused);
  5717 
  5718 * HOL: fewer consts declared as global (e.g. have to refer to
  5719 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5720 
  5721 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5722 in case of overlap with user translations (e.g. judgements over
  5723 tuples); (note that the underlying logical represenation is still
  5724 bogus);
  5725 
  5726 
  5727 *** ZF ***
  5728 
  5729 * ZF: simplification automatically cancels common terms in arithmetic
  5730 expressions over nat and int;
  5731 
  5732 * ZF: new treatment of nat to minimize type-checking: all operators
  5733 coerce their operands to a natural number using the function natify,
  5734 making the algebraic laws unconditional;
  5735 
  5736 * ZF: as above, for int: operators coerce their operands to an integer
  5737 using the function intify;
  5738 
  5739 * ZF: the integer library now contains many of the usual laws for the
  5740 orderings, including $<=, and monotonicity laws for $+ and $*;
  5741 
  5742 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5743 simplification;
  5744 
  5745 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5746 to the simplifier and classical reasoner simultaneously;
  5747 
  5748 
  5749 *** General ***
  5750 
  5751 * Provers: blast_tac now handles actual object-logic rules as
  5752 assumptions; note that auto_tac uses blast_tac internally as well;
  5753 
  5754 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5755 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5756 
  5757 * Provers: delrules now handles destruct rules as well (no longer need
  5758 explicit make_elim);
  5759 
  5760 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5761   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5762 use instead the strong form,
  5763   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5764 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5765 from destruct-rules;
  5766 
  5767 * Provers: Simplifier.easy_setup provides a fast path to basic
  5768 Simplifier setup for new object-logics;
  5769 
  5770 * Pure: AST translation rules no longer require constant head on LHS;
  5771 
  5772 * Pure: improved name spaces: ambiguous output is qualified; support
  5773 for hiding of names;
  5774 
  5775 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5776 XSYMBOL_HOME; no longer need to do manual configuration in most
  5777 situations;
  5778 
  5779 * system: compression of ML heaps images may now be controlled via -c
  5780 option of isabelle and isatool usedir (currently only observed by
  5781 Poly/ML);
  5782 
  5783 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5784 useful for remote X11);
  5785 
  5786 * system: provide TAGS file for Isabelle sources;
  5787 
  5788 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5789 order;
  5790 
  5791 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5792 timing flag supersedes proof_timing and Toplevel.trace;
  5793 
  5794 * ML: new combinators |>> and |>>> for incremental transformations
  5795 with secondary results (e.g. certain theory extensions):
  5796 
  5797 * ML: PureThy.add_defs gets additional argument to indicate potential
  5798 overloading (usually false);
  5799 
  5800 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5801 results;
  5802 
  5803 
  5804 
  5805 New in Isabelle99 (October 1999)
  5806 --------------------------------
  5807 
  5808 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5809 
  5810 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5811 are no longer simplified.  (This allows the simplifier to unfold recursive
  5812 functional programs.)  To restore the old behaviour, declare
  5813 
  5814     Delcongs [if_weak_cong];
  5815 
  5816 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5817 complement;
  5818 
  5819 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5820 
  5821 * HOL/datatype: mutual_induct_tac no longer exists --
  5822   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5823 
  5824 * HOL/typedef: fixed type inference for representing set; type
  5825 arguments now have to occur explicitly on the rhs as type constraints;
  5826 
  5827 * ZF: The con_defs part of an inductive definition may no longer refer
  5828 to constants declared in the same theory;
  5829 
  5830 * HOL, ZF: the function mk_cases, generated by the inductive
  5831 definition package, has lost an argument.  To simplify its result, it
  5832 uses the default simpset instead of a supplied list of theorems.
  5833 
  5834 * HOL/List: the constructors of type list are now Nil and Cons;
  5835 
  5836 * Simplifier: the type of the infix ML functions
  5837         setSSolver addSSolver setSolver addSolver
  5838 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5839 for packaging solvers. A solver is created via
  5840         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5841 where the string argument is only a comment.
  5842 
  5843 
  5844 *** Proof tools ***
  5845 
  5846 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5847 decision procedure for linear arithmetic. Currently it is used for
  5848 types `nat', `int', and `real' in HOL (see below); it can, should and
  5849 will be instantiated for other types and logics as well.
  5850 
  5851 * The simplifier now accepts rewrite rules with flexible heads, eg
  5852      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5853   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5854   matching.
  5855 
  5856 
  5857 *** General ***
  5858 
  5859 * New Isabelle/Isar subsystem provides an alternative to traditional
  5860 tactical theorem proving; together with the ProofGeneral/isar user
  5861 interface it offers an interactive environment for developing human
  5862 readable proof documents (Isar == Intelligible semi-automated
  5863 reasoning); for further information see isatool doc isar-ref,
  5864 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5865 
  5866 * improved and simplified presentation of theories: better HTML markup
  5867 (including colors), graph views in several sizes; isatool usedir now
  5868 provides a proper interface for user theories (via -P option); actual
  5869 document preparation based on (PDF)LaTeX is available as well (for
  5870 new-style theories only); see isatool doc system for more information;
  5871 
  5872 * native support for Proof General, both for classic Isabelle and
  5873 Isabelle/Isar;
  5874 
  5875 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5876 using the graph browser tool;
  5877 
  5878 * Isabelle manuals now also available as PDF;
  5879 
  5880 * theory loader rewritten from scratch (may not be fully
  5881 bug-compatible); old loadpath variable has been replaced by show_path,
  5882 add_path, del_path, reset_path functions; new operations such as
  5883 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5884 isatool doc ref);
  5885 
  5886 * improved isatool install: option -k creates KDE application icon,
  5887 option -p DIR installs standalone binaries;
  5888 
  5889 * added ML_PLATFORM setting (useful for cross-platform installations);
  5890 more robust handling of platform specific ML images for SML/NJ;
  5891 
  5892 * the settings environment is now statically scoped, i.e. it is never
  5893 created again in sub-processes invoked from isabelle, isatool, or
  5894 Isabelle;
  5895 
  5896 * path element specification '~~' refers to '$ISABELLE_HOME';
  5897 
  5898 * in locales, the "assumes" and "defines" parts may be omitted if
  5899 empty;
  5900 
  5901 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5902 long arrows);
  5903 
  5904 * new print_mode "HTML";
  5905 
  5906 * new flag show_tags controls display of tags of theorems (which are
  5907 basically just comments that may be attached by some tools);
  5908 
  5909 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5910 mode and goal output format:
  5911 
  5912 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5913 244c244
  5914 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5915 ---
  5916 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5917 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5918 181c181
  5919 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5920 ---
  5921 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5922 
  5923 * function bind_thms stores lists of theorems (cf. bind_thm);
  5924 
  5925 * new shorthand tactics ftac, eatac, datac, fatac;
  5926 
  5927 * qed (and friends) now accept "" as result name; in that case the
  5928 theorem is not stored, but proper checks and presentation of the
  5929 result still apply;
  5930 
  5931 * theorem database now also indexes constants "Trueprop", "all",
  5932 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5933 
  5934 
  5935 *** HOL ***
  5936 
  5937 ** HOL arithmetic **
  5938 
  5939 * There are now decision procedures for linear arithmetic over nat and
  5940 int:
  5941 
  5942 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5943 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5944 are treated as atomic; subformulae not involving type `nat' or `int'
  5945 are ignored; quantified subformulae are ignored unless they are
  5946 positive universal or negative existential. The tactic has to be
  5947 invoked by hand and can be a little bit slow. In particular, the
  5948 running time is exponential in the number of occurrences of `min' and
  5949 `max', and `-' on `nat'.
  5950 
  5951 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5952 (negated) (in)equalities among the premises and the conclusion into
  5953 account (i.e. no compound formulae) and does not know about `min' and
  5954 `max', and `-' on `nat'. It is fast and is used automatically by the
  5955 simplifier.
  5956 
  5957 NB: At the moment, these decision procedures do not cope with mixed
  5958 nat/int formulae where the two parts interact, such as `m < n ==>
  5959 int(m) < int(n)'.
  5960 
  5961 * HOL/Numeral provides a generic theory of numerals (encoded
  5962 efficiently as bit strings); setup for types nat/int/real is in place;
  5963 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5964 int, existing theories and proof scripts may require a few additional
  5965 type constraints;
  5966 
  5967 * integer division and remainder can now be performed on constant
  5968 arguments;
  5969 
  5970 * many properties of integer multiplication, division and remainder
  5971 are now available;
  5972 
  5973 * An interface to the Stanford Validity Checker (SVC) is available through the
  5974 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5975 are proved automatically.  SVC must be installed separately, and its results
  5976 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5977 invocation of the underlying oracle).  For SVC see
  5978   http://verify.stanford.edu/SVC
  5979 
  5980 * IsaMakefile: the HOL-Real target now builds an actual image;
  5981 
  5982 
  5983 ** HOL misc **
  5984 
  5985 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5986 (in Isabelle/Isar) -- by Gertrud Bauer;
  5987 
  5988 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5989 analysis for assembly languages with subtypes;
  5990 
  5991 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5992 -- avoids syntactic ambiguities and treats state, transition, and
  5993 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5994 changed syntax and (many) tactics;
  5995 
  5996 * HOL/inductive: Now also handles more general introduction rules such
  5997   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5998   theorems are now maintained within the theory (maintained via the
  5999   "mono" attribute);
  6000 
  6001 * HOL/datatype: Now also handles arbitrarily branching datatypes
  6002   (using function types) such as
  6003 
  6004   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  6005 
  6006 * HOL/record: record_simproc (part of the default simpset) takes care
  6007 of selectors applied to updated records; record_split_tac is no longer
  6008 part of the default claset; update_defs may now be removed from the
  6009 simpset in many cases; COMPATIBILITY: old behavior achieved by
  6010 
  6011   claset_ref () := claset() addSWrapper record_split_wrapper;
  6012   Delsimprocs [record_simproc]
  6013 
  6014 * HOL/typedef: fixed type inference for representing set; type
  6015 arguments now have to occur explicitly on the rhs as type constraints;
  6016 
  6017 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  6018 names rather than an ML expression;
  6019 
  6020 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  6021 supplied later.  Program schemes can be defined, such as
  6022     "While B C s = (if B s then While B C (C s) else s)"
  6023 where the well-founded relation can be chosen after B and C have been given.
  6024 
  6025 * HOL/List: the constructors of type list are now Nil and Cons;
  6026 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  6027 course, ML tools referring to List.list.op # etc. have to be adapted;
  6028 
  6029 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  6030 disabled by default; run isabelle with option -m HOL to get back to
  6031 the original Gordon/HOL-style output;
  6032 
  6033 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  6034 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  6035 
  6036 * HOL basic syntax simplified (more orthogonal): all variants of
  6037 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  6038 Eps operator is provided as well: "SOME x. P[x]";
  6039 
  6040 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  6041 
  6042 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  6043 thus available for user theories;
  6044 
  6045 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  6046 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  6047 time;
  6048 
  6049 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  6050 several times and then mp;
  6051 
  6052 
  6053 *** LK ***
  6054 
  6055 * the notation <<...>> is now available as a notation for sequences of
  6056 formulas;
  6057 
  6058 * the simplifier is now installed
  6059 
  6060 * the axiom system has been generalized (thanks to Soren Heilmann)
  6061 
  6062 * the classical reasoner now has a default rule database
  6063 
  6064 
  6065 *** ZF ***
  6066 
  6067 * new primrec section allows primitive recursive functions to be given
  6068 directly (as in HOL) over datatypes and the natural numbers;
  6069 
  6070 * new tactics induct_tac and exhaust_tac for induction (or case
  6071 analysis) over datatypes and the natural numbers;
  6072 
  6073 * the datatype declaration of type T now defines the recursor T_rec;
  6074 
  6075 * simplification automatically does freeness reasoning for datatype
  6076 constructors;
  6077 
  6078 * automatic type-inference, with AddTCs command to insert new
  6079 type-checking rules;
  6080 
  6081 * datatype introduction rules are now added as Safe Introduction rules
  6082 to the claset;
  6083 
  6084 * the syntax "if P then x else y" is now available in addition to
  6085 if(P,x,y);
  6086 
  6087 
  6088 *** Internal programming interfaces ***
  6089 
  6090 * tuned simplifier trace output; new flag debug_simp;
  6091 
  6092 * structures Vartab / Termtab (instances of TableFun) offer efficient
  6093 tables indexed by indexname_ord / term_ord (compatible with aconv);
  6094 
  6095 * AxClass.axclass_tac lost the theory argument;
  6096 
  6097 * tuned current_goals_markers semantics: begin / end goal avoids
  6098 printing empty lines;
  6099 
  6100 * removed prs and prs_fn hook, which was broken because it did not
  6101 include \n in its semantics, forcing writeln to add one
  6102 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  6103 string -> unit if you really want to output text without newline;
  6104 
  6105 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  6106 plain output, interface builders may have to enable 'isabelle_font'
  6107 mode to get Isabelle font glyphs as before;
  6108 
  6109 * refined token_translation interface; INCOMPATIBILITY: output length
  6110 now of type real instead of int;
  6111 
  6112 * theory loader actions may be traced via new ThyInfo.add_hook
  6113 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  6114 your own database of information attached to *whole* theories -- as
  6115 opposed to intra-theory data slots offered via TheoryDataFun;
  6116 
  6117 * proper handling of dangling sort hypotheses (at last!);
  6118 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  6119 extra sort hypotheses that can be witnessed from the type signature;
  6120 the force_strip_shyps flag is gone, any remaining shyps are simply
  6121 left in the theorem (with a warning issued by strip_shyps_warning);
  6122 
  6123 
  6124 
  6125 New in Isabelle98-1 (October 1998)
  6126 ----------------------------------
  6127 
  6128 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6129 
  6130 * several changes of automated proof tools;
  6131 
  6132 * HOL: major changes to the inductive and datatype packages, including
  6133 some minor incompatibilities of theory syntax;
  6134 
  6135 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  6136 called `inj_on';
  6137 
  6138 * HOL: removed duplicate thms in Arith:
  6139   less_imp_add_less  should be replaced by  trans_less_add1
  6140   le_imp_add_le      should be replaced by  trans_le_add1
  6141 
  6142 * HOL: unary minus is now overloaded (new type constraints may be
  6143 required);
  6144 
  6145 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  6146 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  6147 now taken as an integer constant.
  6148 
  6149 * Pure: ML function 'theory_of' renamed to 'theory';
  6150 
  6151 
  6152 *** Proof tools ***
  6153 
  6154 * Simplifier:
  6155   1. Asm_full_simp_tac is now more aggressive.
  6156      1. It will sometimes reorient premises if that increases their power to
  6157         simplify.
  6158      2. It does no longer proceed strictly from left to right but may also
  6159         rotate premises to achieve further simplification.
  6160      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  6161      old Asm_full_simp_tac in that it does not rotate premises.
  6162   2. The simplifier now knows a little bit about nat-arithmetic.
  6163 
  6164 * Classical reasoner: wrapper mechanism for the classical reasoner now
  6165 allows for selected deletion of wrappers, by introduction of names for
  6166 wrapper functionals.  This implies that addbefore, addSbefore,
  6167 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  6168 and that adding two tactics with the same name overwrites the first
  6169 one (emitting a warning).
  6170   type wrapper = (int -> tactic) -> (int -> tactic)
  6171   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  6172   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  6173   delWrapper, delSWrapper: claset *  string            -> claset
  6174   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  6175 
  6176 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  6177 semantics; addbefore now affects only the unsafe part of step_tac
  6178 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  6179 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  6180 by Force_tac;
  6181 
  6182 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  6183 compWrapper; added safe wrapper (and access functions for it);
  6184 
  6185 * HOL/split_all_tac is now much faster and fails if there is nothing
  6186 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  6187 and the names of the automatically generated variables have changed.
  6188 split_all_tac has moved within claset() from unsafe wrappers to safe
  6189 wrappers, which means that !!-bound variables are split much more
  6190 aggressively, and safe_tac and clarify_tac now split such variables.
  6191 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  6192 Note: the same holds for record_split_tac, which does the job of
  6193 split_all_tac for record fields.
  6194 
  6195 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  6196 permanently to the default simpset using Addsplits just like
  6197 Addsimps. They can be removed via Delsplits just like
  6198 Delsimps. Lower-case versions are also available.
  6199 
  6200 * HOL/Simplifier: The rule split_if is now part of the default
  6201 simpset. This means that the simplifier will eliminate all occurrences
  6202 of if-then-else in the conclusion of a goal. To prevent this, you can
  6203 either remove split_if completely from the default simpset by
  6204 `Delsplits [split_if]' or remove it in a specific call of the
  6205 simplifier using `... delsplits [split_if]'.  You can also add/delete
  6206 other case splitting rules to/from the default simpset: every datatype
  6207 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  6208 t is the name of the datatype).
  6209 
  6210 * Classical reasoner / Simplifier combination: new force_tac (and
  6211 derivatives Force_tac, force) combines rewriting and classical
  6212 reasoning (and whatever other tools) similarly to auto_tac, but is
  6213 aimed to solve the given subgoal completely.
  6214 
  6215 
  6216 *** General ***
  6217 
  6218 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  6219 and `goalw': the theory is no longer needed as an explicit argument -
  6220 the current theory context is used; assumptions are no longer returned
  6221 at the ML-level unless one of them starts with ==> or !!; it is
  6222 recommended to convert to these new commands using isatool fixgoal
  6223 (backup your sources first!);
  6224 
  6225 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  6226 the current theory context, and 'theory' to lookup stored theories;
  6227 
  6228 * new theory section 'locale' for declaring constants, assumptions and
  6229 definitions that have local scope;
  6230 
  6231 * new theory section 'nonterminals' for purely synta