NEWS
author wenzelm
Sun Apr 11 14:06:35 2010 +0200 (2010-04-11)
changeset 36105 42c37cf849cd
parent 36096 abc6a2ea4b88
child 36147 b43b22f63665
permissions -rw-r--r--
modernized datatype constructors;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Authentic syntax for *all* logical entities (type classes, type
    10 constructors, term constants): provides simple and robust
    11 correspondence between formal entities and concrete syntax.  Within
    12 the parse tree / AST representations, "constants" are decorated by
    13 their category (class, type, const) and spelled out explicitly with
    14 their full internal name.
    15 
    16 Substantial INCOMPATIBILITY concerning low-level syntax declarations
    17 and translations (translation rules and translation functions in ML).
    18 Some hints on upgrading:
    19 
    20   - Many existing uses of 'syntax' and 'translations' can be replaced
    21     by more modern 'type_notation', 'notation' and 'abbreviation',
    22     which are independent of this issue.
    23 
    24   - 'translations' require markup within the AST; the term syntax
    25     provides the following special forms:
    26 
    27       CONST c   -- produces syntax version of constant c from context
    28       XCONST c  -- literally c, checked as constant from context
    29       c         -- literally c, if declared by 'syntax'
    30 
    31     Plain identifiers are treated as AST variables -- occasionally the
    32     system indicates accidental variables via the error "rhs contains
    33     extra variables".
    34 
    35     Type classes and type constructors are marked according to their
    36     concrete syntax.  Some old translations rules need to be written
    37     for the "type" category, using type constructor application
    38     instead of pseudo-term application of the default category
    39     "logic".
    40 
    41   - 'parse_translation' etc. in ML may use the following
    42     antiquotations:
    43 
    44       @{class_syntax c}   -- type class c within parse tree / AST
    45       @{term_syntax c}    -- type constructor c within parse tree / AST
    46       @{const_syntax c}   -- ML version of "CONST c" above
    47       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
    48 
    49   - Literal types within 'typed_print_translations', i.e. those *not*
    50     represented as pseudo-terms are represented verbatim.  Use @{class
    51     c} or @{type_name c} here instead of the above syntax
    52     antiquotations.
    53 
    54 Note that old non-authentic syntax was based on unqualified base
    55 names, so all of the above "constant" names would coincide.  Recall
    56 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
    57 diagnose syntax problems.
    58 
    59 * Type constructors admit general mixfix syntax, not just infix.
    60 
    61 * Use of cumulative prems via "!" in some proof methods has been
    62 discontinued (legacy feature).
    63 
    64 * References 'trace_simp' and 'debug_simp' have been replaced by
    65 configuration options stored in the context. Enabling tracing
    66 (the case of debugging is similar) in proofs works via
    67 
    68   using [[trace_simp=true]]
    69 
    70 Tracing is then active for all invocations of the simplifier
    71 in subsequent goal refinement steps. Tracing may also still be
    72 enabled or disabled via the ProofGeneral settings menu.
    73 
    74 
    75 *** Pure ***
    76 
    77 * Local theory specifications may depend on extra type variables that
    78 are not present in the result type -- arguments TYPE('a) :: 'a itself
    79 are added internally.  For example:
    80 
    81   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
    82 
    83 * Code generator: details of internal data cache have no impact on
    84 the user space functionality any longer.
    85 
    86 * Methods unfold_locales and intro_locales ignore non-locale subgoals.  This
    87 is more appropriate for interpretations with 'where'.  INCOMPATIBILITY.
    88 
    89 * Discontinued unnamed infix syntax (legacy feature for many years) --
    90 need to specify constant name and syntax separately.  Internal ML
    91 datatype constructors have been renamed from InfixName to Infix etc.
    92 Minor INCOMPATIBILITY.
    93 
    94 * Commands 'type_notation' and 'no_type_notation' declare type syntax
    95 within a local theory context, with explicit checking of the
    96 constructors involved (in contrast to the raw 'syntax' versions).
    97 
    98 * Command 'typedecl' now works within a local theory context --
    99 without introducing dependencies on parameters or assumptions, which
   100 is not possible in Isabelle/Pure.
   101 
   102 * Proof terms: Type substitutions on proof constants now use canonical
   103 order of type variables. INCOMPATIBILITY: Tools working with proof
   104 terms may need to be adapted.
   105 
   106 
   107 *** HOL ***
   108 
   109 * Command 'typedef' now works within a local theory context -- without
   110 introducing dependencies on parameters or assumptions, which is not
   111 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   112 contain multiple interpretations of local typedefs (with different
   113 non-emptiness proofs), even in a global theory context.
   114 
   115 * Theory Library/Coinductive_List has been removed -- superceded by
   116 AFP/thys/Coinductive.
   117 
   118 * Split off theory Big_Operators containing setsum, setprod, Inf_fin, Sup_fin,
   119 Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   120 
   121 * Theory "Rational" renamed to "Rat", for consistency with "Nat", "Int" etc.
   122 INCOMPATIBILITY.
   123 
   124 * New set of rules "ac_simps" provides combined assoc / commute rewrites
   125 for all interpretations of the appropriate generic locales.
   126 
   127 * Renamed theory "OrderedGroup" to "Groups" and split theory "Ring_and_Field"
   128 into theories "Rings" and "Fields";  for more appropriate and more
   129 consistent names suitable for name prefixes within the HOL theories.
   130 INCOMPATIBILITY.
   131 
   132 * Some generic constants have been put to appropriate theories:
   133 
   134     less_eq, less: Orderings
   135     zero, one, plus, minus, uminus, times, abs, sgn: Groups
   136     inverse, divide: Rings
   137 
   138 INCOMPATIBILITY.
   139 
   140 * Class division_ring also requires proof of fact divide_inverse.  However instantiation
   141 of parameter divide has also been required previously.  INCOMPATIBILITY.
   142 
   143 * More consistent naming of type classes involving orderings (and lattices):
   144 
   145     lower_semilattice                   ~> semilattice_inf
   146     upper_semilattice                   ~> semilattice_sup
   147 
   148     dense_linear_order                  ~> dense_linorder
   149 
   150     pordered_ab_group_add               ~> ordered_ab_group_add
   151     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   152     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   153     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   154     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   155     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   156     pordered_cancel_semiring            ~> ordered_cancel_semiring
   157     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   158     pordered_comm_ring                  ~> ordered_comm_ring
   159     pordered_comm_semiring              ~> ordered_comm_semiring
   160     pordered_ring                       ~> ordered_ring
   161     pordered_ring_abs                   ~> ordered_ring_abs
   162     pordered_semiring                   ~> ordered_semiring
   163 
   164     ordered_ab_group_add                ~> linordered_ab_group_add
   165     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   166     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   167     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   168     ordered_field                       ~> linordered_field
   169     ordered_field_no_lb                 ~> linordered_field_no_lb
   170     ordered_field_no_ub                 ~> linordered_field_no_ub
   171     ordered_field_dense_linear_order    ~> dense_linordered_field
   172     ordered_idom                        ~> linordered_idom
   173     ordered_ring                        ~> linordered_ring
   174     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   175     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   176     ordered_ring_strict                 ~> linordered_ring_strict
   177     ordered_semidom                     ~> linordered_semidom
   178     ordered_semiring                    ~> linordered_semiring
   179     ordered_semiring_1                  ~> linordered_semiring_1
   180     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   181     ordered_semiring_strict             ~> linordered_semiring_strict
   182 
   183   The following slightly odd type classes have been moved to
   184   a separate theory Library/Lattice_Algebras.thy:
   185 
   186     lordered_ab_group_add               ~> lattice_ab_group_add
   187     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   188     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   189     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   190     lordered_ring                       ~> lattice_ring
   191 
   192 INCOMPATIBILITY.
   193 
   194 * HOLogic.strip_psplit: types are returned in syntactic order, similar
   195 to other strip and tuple operations.  INCOMPATIBILITY.
   196 
   197 * Various old-style primrec specifications in the HOL theories have been
   198 replaced by new-style primrec, especially in theory List.  The corresponding
   199 constants now have authentic syntax.  INCOMPATIBILITY.
   200 
   201 * Reorganized theory Multiset: swapped notation of pointwise and multiset order:
   202   * pointwise ordering is instance of class order with standard syntax <= and <;
   203   * multiset ordering has syntax <=# and <#; partial order properties are provided
   204       by means of interpretation with prefix multiset_order.
   205 Less duplication, less historical organization of sections,
   206 conversion from associations lists to multisets, rudimentary code generation.
   207 Use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union, if needed.
   208 INCOMPATIBILITY.
   209 
   210 * Reorganized theory Sum_Type; Inl and Inr now have authentic syntax.
   211 INCOMPATIBILITY.
   212 
   213 * Code generation: ML and OCaml code is decorated with signatures.
   214 
   215 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   216 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   217 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   218 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   219 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   220 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   221 
   222 * Theory Finite_Set and List: some lemmas have been generalized from
   223 sets to lattices:
   224 
   225   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   226   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   227   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   228   union_Union_fold_union        ~> sup_Sup_fold_sup
   229   Inter_fold_inter              ~> Inf_fold_inf
   230   Union_fold_union              ~> Sup_fold_sup
   231   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   232   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   233   INTER_fold_inter              ~> INFI_fold_inf
   234   UNION_fold_union              ~> SUPR_fold_sup
   235 
   236 * Theory List: added transpose.
   237 
   238 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   239 clash with new theory Quotient in Main HOL.
   240 
   241 * Library/Nat_Bijection.thy is a collection of bijective functions
   242 between nat and other types, which supersedes the older libraries
   243 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   244 
   245   Constants:
   246   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   247   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   248   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   249   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   250   Countable.pair_encode           ~> prod_encode
   251   NatIso.prod2nat                 ~> prod_encode
   252   NatIso.nat2prod                 ~> prod_decode
   253   NatIso.sum2nat                  ~> sum_encode
   254   NatIso.nat2sum                  ~> sum_decode
   255   NatIso.list2nat                 ~> list_encode
   256   NatIso.nat2list                 ~> list_decode
   257   NatIso.set2nat                  ~> set_encode
   258   NatIso.nat2set                  ~> set_decode
   259 
   260   Lemmas:
   261   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   262   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   263   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   264   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   265   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   266   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   267   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   268   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   269   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   270   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   271   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   272   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   273   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   274 
   275 
   276 *** ML ***
   277 
   278 * Antiquotations for basic formal entities:
   279 
   280     @{class NAME}         -- type class
   281     @{class_syntax NAME}  -- syntax representation of the above
   282 
   283     @{type_name NAME}     -- logical type
   284     @{type_abbrev NAME}   -- type abbreviation
   285     @{nonterminal NAME}   -- type of concrete syntactic category
   286     @{type_syntax NAME}   -- syntax representation of any of the above
   287 
   288     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   289     @{const_abbrev NAME}  -- abbreviated constant
   290     @{const_syntax NAME}  -- syntax representation of any of the above
   291 
   292 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   293 syntax constant (cf. 'syntax' command).
   294 
   295 * Renamed old-style Drule.standard to Drule.export_without_context, to
   296 emphasize that this is in no way a standard operation.
   297 INCOMPATIBILITY.
   298 
   299 * Curried take and drop in library.ML; negative length is interpreted
   300 as infinity (as in chop).  INCOMPATIBILITY.
   301 
   302 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   303 usual for resolution.  Rare INCOMPATIBILITY.
   304 
   305 * Discontinued old TheoryDataFun with its copy/init operation -- data
   306 needs to be pure.  Functor Theory_Data_PP retains the traditional
   307 Pretty.pp argument to merge, which is absent in the standard
   308 Theory_Data version.
   309 
   310 * Renamed varify/unvarify operations to varify_global/unvarify_global
   311 to emphasize that these only work in a global situation (which is
   312 quite rare).
   313 
   314 * Configuration options now admit dynamic default values, depending on
   315 the context or even global references.
   316 
   317 
   318 *** System ***
   319 
   320 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   321 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   322 proof terms are enabled unconditionally in the new HOL-Proofs image.
   323 
   324 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   325 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   326 respectively.
   327 
   328 
   329 
   330 New in Isabelle2009-1 (December 2009)
   331 -------------------------------------
   332 
   333 *** General ***
   334 
   335 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   336 one backslash should be used, even in ML sources.
   337 
   338 
   339 *** Pure ***
   340 
   341 * Locale interpretation propagates mixins along the locale hierarchy.
   342 The currently only available mixins are the equations used to map
   343 local definitions to terms of the target domain of an interpretation.
   344 
   345 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   346 loc" to print all interpretations of locale "loc" in the theory.
   347 Interpretations in proofs are not shown.
   348 
   349 * Thoroughly revised locales tutorial.  New section on conditional
   350 interpretation.
   351 
   352 * On instantiation of classes, remaining undefined class parameters
   353 are formally declared.  INCOMPATIBILITY.
   354 
   355 
   356 *** Document preparation ***
   357 
   358 * New generalized style concept for printing terms: @{foo (style) ...}
   359 instead of @{foo_style style ...}  (old form is still retained for
   360 backward compatibility).  Styles can be also applied for
   361 antiquotations prop, term_type and typeof.
   362 
   363 
   364 *** HOL ***
   365 
   366 * New proof method "smt" for a combination of first-order logic with
   367 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   368 fixed-size bitvectors; there is also basic support for higher-order
   369 features (esp. lambda abstractions).  It is an incomplete decision
   370 procedure based on external SMT solvers using the oracle mechanism;
   371 for the SMT solver Z3, this method is proof-producing.  Certificates
   372 are provided to avoid calling the external solvers solely for
   373 re-checking proofs.  Due to a remote SMT service there is no need for
   374 installing SMT solvers locally.  See src/HOL/SMT.
   375 
   376 * New commands to load and prove verification conditions generated by
   377 the Boogie program verifier or derived systems (e.g. the Verifying C
   378 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   379 
   380 * New counterexample generator tool 'nitpick' based on the Kodkod
   381 relational model finder.  See src/HOL/Tools/Nitpick and
   382 src/HOL/Nitpick_Examples.
   383 
   384 * New commands 'code_pred' and 'values' to invoke the predicate
   385 compiler and to enumerate values of inductive predicates.
   386 
   387 * A tabled implementation of the reflexive transitive closure.
   388 
   389 * New implementation of quickcheck uses generic code generator;
   390 default generators are provided for all suitable HOL types, records
   391 and datatypes.  Old quickcheck can be re-activated importing theory
   392 Library/SML_Quickcheck.
   393 
   394 * New testing tool Mirabelle for automated proof tools.  Applies
   395 several tools and tactics like sledgehammer, metis, or quickcheck, to
   396 every proof step in a theory.  To be used in batch mode via the
   397 "mirabelle" utility.
   398 
   399 * New proof method "sos" (sum of squares) for nonlinear real
   400 arithmetic (originally due to John Harison). It requires theory
   401 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   402 works well in practice on quantifier-free real arithmetic with +, -,
   403 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   404 inequalities between polynomials.  It makes use of external
   405 semidefinite programming solvers.  Method "sos" generates a
   406 certificate that can be pasted into the proof thus avoiding the need
   407 to call an external tool every time the proof is checked.  See
   408 src/HOL/Library/Sum_Of_Squares.
   409 
   410 * New method "linarith" invokes existing linear arithmetic decision
   411 procedure only.
   412 
   413 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   414 
   415 * New Sledgehammer option "Full Types" in Proof General settings menu.
   416 Causes full type information to be output to the ATPs.  This slows
   417 ATPs down considerably but eliminates a source of unsound "proofs"
   418 that fail later.
   419 
   420 * New method "metisFT": A version of metis that uses full type
   421 information in order to avoid failures of proof reconstruction.
   422 
   423 * New evaluator "approximate" approximates an real valued term using
   424 the same method as the approximation method.
   425 
   426 * Method "approximate" now supports arithmetic expressions as
   427 boundaries of intervals and implements interval splitting and Taylor
   428 series expansion.
   429 
   430 * ML antiquotation @{code_datatype} inserts definition of a datatype
   431 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   432 
   433 * New theory SupInf of the supremum and infimum operators for sets of
   434 reals.
   435 
   436 * New theory Probability, which contains a development of measure
   437 theory, eventually leading to Lebesgue integration and probability.
   438 
   439 * Extended Multivariate Analysis to include derivation and Brouwer's
   440 fixpoint theorem.
   441 
   442 * Reorganization of number theory, INCOMPATIBILITY:
   443   - new number theory development for nat and int, in theories Divides
   444     and GCD as well as in new session Number_Theory
   445   - some constants and facts now suffixed with _nat and _int
   446     accordingly
   447   - former session NumberTheory now named Old_Number_Theory, including
   448     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   449   - moved theory Pocklington from src/HOL/Library to
   450     src/HOL/Old_Number_Theory
   451 
   452 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   453 lcm of finite and infinite sets. It is shown that they form a complete
   454 lattice.
   455 
   456 * Class semiring_div requires superclass no_zero_divisors and proof of
   457 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   458 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   459 generalized to class semiring_div, subsuming former theorems
   460 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   461 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   462 INCOMPATIBILITY.
   463 
   464 * Refinements to lattice classes and sets:
   465   - less default intro/elim rules in locale variant, more default
   466     intro/elim rules in class variant: more uniformity
   467   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   468     le_inf_iff
   469   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   470     sup_aci)
   471   - renamed ACI to inf_sup_aci
   472   - new class "boolean_algebra"
   473   - class "complete_lattice" moved to separate theory
   474     "Complete_Lattice"; corresponding constants (and abbreviations)
   475     renamed and with authentic syntax:
   476     Set.Inf ~>    Complete_Lattice.Inf
   477     Set.Sup ~>    Complete_Lattice.Sup
   478     Set.INFI ~>   Complete_Lattice.INFI
   479     Set.SUPR ~>   Complete_Lattice.SUPR
   480     Set.Inter ~>  Complete_Lattice.Inter
   481     Set.Union ~>  Complete_Lattice.Union
   482     Set.INTER ~>  Complete_Lattice.INTER
   483     Set.UNION ~>  Complete_Lattice.UNION
   484   - authentic syntax for
   485     Set.Pow
   486     Set.image
   487   - mere abbreviations:
   488     Set.empty               (for bot)
   489     Set.UNIV                (for top)
   490     Set.inter               (for inf, formerly Set.Int)
   491     Set.union               (for sup, formerly Set.Un)
   492     Complete_Lattice.Inter  (for Inf)
   493     Complete_Lattice.Union  (for Sup)
   494     Complete_Lattice.INTER  (for INFI)
   495     Complete_Lattice.UNION  (for SUPR)
   496   - object-logic definitions as far as appropriate
   497 
   498 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   499 Un_subset_iff are explicitly deleted as default simp rules; then also
   500 their lattice counterparts le_inf_iff and le_sup_iff have to be
   501 deleted to achieve the desired effect.
   502 
   503 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   504 rules by default any longer; the same applies to min_max.inf_absorb1
   505 etc.  INCOMPATIBILITY.
   506 
   507 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   508 pred_set_conv by default.  INCOMPATIBILITY.
   509 
   510 * Power operations on relations and functions are now one dedicated
   511 constant "compow" with infix syntax "^^".  Power operation on
   512 multiplicative monoids retains syntax "^" and is now defined generic
   513 in class power.  INCOMPATIBILITY.
   514 
   515 * Relation composition "R O S" now has a more standard argument order:
   516 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   517 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   518 break, since the O_assoc rule was not rewritten like this.  Fix using
   519 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   520 
   521 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   522 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   523 INCOMPATIBILITY.
   524 
   525 * Most rules produced by inductive and datatype package have mandatory
   526 prefixes.  INCOMPATIBILITY.
   527 
   528 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   529 the attribute of the same name.  Each of the theorems in the list
   530 DERIV_intros assumes composition with an additional function and
   531 matches a variable to the derivative, which has to be solved by the
   532 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   533 of most elementary terms.  Former Maclauren.DERIV_tac and
   534 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   535 INCOMPATIBILITY.
   536 
   537 * Code generator attributes follow the usual underscore convention:
   538     code_unfold     replaces    code unfold
   539     code_post       replaces    code post
   540     etc.
   541   INCOMPATIBILITY.
   542 
   543 * Renamed methods:
   544     sizechange -> size_change
   545     induct_scheme -> induction_schema
   546   INCOMPATIBILITY.
   547 
   548 * Discontinued abbreviation "arbitrary" of constant "undefined".
   549 INCOMPATIBILITY, use "undefined" directly.
   550 
   551 * Renamed theorems:
   552     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   553     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   554     Suc_plus1 -> Suc_eq_plus1
   555     *anti_sym -> *antisym*
   556     vector_less_eq_def -> vector_le_def
   557   INCOMPATIBILITY.
   558 
   559 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   560 INCOMPATIBILITY.
   561 
   562 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   563 INCOMPATIBILITY.
   564 
   565 
   566 *** HOLCF ***
   567 
   568 * Theory Representable defines a class "rep" of domains that are
   569 representable (via an ep-pair) in the universal domain type "udom".
   570 Instances are provided for all type constructors defined in HOLCF.
   571 
   572 * The 'new_domain' command is a purely definitional version of the
   573 domain package, for representable domains.  Syntax is identical to the
   574 old domain package.  The 'new_domain' package also supports indirect
   575 recursion using previously-defined type constructors.  See
   576 src/HOLCF/ex/New_Domain.thy for examples.
   577 
   578 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   579 on the left-hand side of an equation, and then performs
   580 simplification.  Rewriting is done using rules declared with the
   581 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   582 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   583 
   584 * The pattern-match compiler in 'fixrec' can now handle constructors
   585 with HOL function types.  Pattern-match combinators for the Pair
   586 constructor are pre-configured.
   587 
   588 * The 'fixrec' package now produces better fixed-point induction rules
   589 for mutually-recursive definitions:  Induction rules have conclusions
   590 of the form "P foo bar" instead of "P <foo, bar>".
   591 
   592 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   593 been renamed to "below".  The name "below" now replaces "less" in many
   594 theorem names.  (Legacy theorem names using "less" are still supported
   595 as well.)
   596 
   597 * The 'fixrec' package now supports "bottom patterns".  Bottom
   598 patterns can be used to generate strictness rules, or to make
   599 functions more strict (much like the bang-patterns supported by the
   600 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   601 examples.
   602 
   603 
   604 *** ML ***
   605 
   606 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   607 errors and run-time exceptions, including detailed source positions.
   608 
   609 * Structure Name_Space (formerly NameSpace) now manages uniquely
   610 identified entries, with some additional information such as source
   611 position, logical grouping etc.
   612 
   613 * Theory and context data is now introduced by the simplified and
   614 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   615 to be pure, but the old TheoryDataFun for mutable data (with explicit
   616 copy operation) is still available for some time.
   617 
   618 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   619 provides a high-level programming interface to synchronized state
   620 variables with atomic update.  This works via pure function
   621 application within a critical section -- its runtime should be as
   622 short as possible; beware of deadlocks if critical code is nested,
   623 either directly or indirectly via other synchronized variables!
   624 
   625 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   626 wraps raw ML references, explicitly indicating their non-thread-safe
   627 behaviour.  The Isar toplevel keeps this structure open, to
   628 accommodate Proof General as well as quick and dirty interactive
   629 experiments with references.
   630 
   631 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   632 parallel tactical reasoning.
   633 
   634 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   635 are similar to SUBPROOF, but are slightly more flexible: only the
   636 specified parts of the subgoal are imported into the context, and the
   637 body tactic may introduce new subgoals and schematic variables.
   638 
   639 * Old tactical METAHYPS, which does not observe the proof context, has
   640 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   641 or Subgoal.FOCUS etc.
   642 
   643 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   644 functors have their own ML name space there is no point to mark them
   645 separately.)  Minor INCOMPATIBILITY.
   646 
   647 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   648 
   649 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   650 INCOMPATIBILITY.
   651 
   652 * Operations of structure Skip_Proof no longer require quick_and_dirty
   653 mode, which avoids critical setmp.
   654 
   655 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   656 combinators for "args".  INCOMPATIBILITY, need to use simplified
   657 Attrib/Method.setup introduced in Isabelle2009.
   658 
   659 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   660 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   661 last resort.  INCOMPATIBILITY.
   662 
   663 * Display.pretty_thm now requires a proper context (cf. former
   664 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   665 or even Display.pretty_thm_without_context as last resort.
   666 INCOMPATIBILITY.
   667 
   668 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   669 Syntax.pretty_typ/term directly, preferably with proper context
   670 instead of global theory.
   671 
   672 
   673 *** System ***
   674 
   675 * Further fine tuning of parallel proof checking, scales up to 8 cores
   676 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   677 usedir option -q.
   678 
   679 * Support for additional "Isabelle components" via etc/components, see
   680 also the system manual.
   681 
   682 * The isabelle makeall tool now operates on all components with
   683 IsaMakefile, not just hardwired "logics".
   684 
   685 * Removed "compress" option from isabelle-process and isabelle usedir;
   686 this is always enabled.
   687 
   688 * Discontinued support for Poly/ML 4.x versions.
   689 
   690 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   691 on a given logic image.  This requires the lighttpd webserver and is
   692 currently supported on Linux only.
   693 
   694 
   695 
   696 New in Isabelle2009 (April 2009)
   697 --------------------------------
   698 
   699 *** General ***
   700 
   701 * Simplified main Isabelle executables, with less surprises on
   702 case-insensitive file-systems (such as Mac OS).
   703 
   704   - The main Isabelle tool wrapper is now called "isabelle" instead of
   705     "isatool."
   706 
   707   - The former "isabelle" alias for "isabelle-process" has been
   708     removed (should rarely occur to regular users).
   709 
   710   - The former "isabelle-interface" and its alias "Isabelle" have been
   711     removed (interfaces are now regular Isabelle tools).
   712 
   713 Within scripts and make files, the Isabelle environment variables
   714 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   715 respectively.  (The latter are still available as legacy feature.)
   716 
   717 The old isabelle-interface wrapper could react in confusing ways if
   718 the interface was uninstalled or changed otherwise.  Individual
   719 interface tool configuration is now more explicit, see also the
   720 Isabelle system manual.  In particular, Proof General is now available
   721 via "isabelle emacs".
   722 
   723 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   724 purge installed copies of Isabelle executables and re-run "isabelle
   725 install -p ...", or use symlinks.
   726 
   727 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   728 old ~/isabelle, which was slightly non-standard and apt to cause
   729 surprises on case-insensitive file-systems (such as Mac OS).
   730 
   731 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   732 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   733 care is required when using older releases of Isabelle.  Note that
   734 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   735 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   736 
   737 * Proofs of fully specified statements are run in parallel on
   738 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   739 a regular 4-core machine, if the initial heap space is made reasonably
   740 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   741 
   742 * The main reference manuals ("isar-ref", "implementation", and
   743 "system") have been updated and extended.  Formally checked references
   744 as hyperlinks are now available uniformly.
   745 
   746 
   747 *** Pure ***
   748 
   749 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   750 respects.  The most important changes are listed below.  See the
   751 Tutorial on Locales ("locales" manual) for details.
   752 
   753 - In locale expressions, instantiation replaces renaming.  Parameters
   754 must be declared in a for clause.  To aid compatibility with previous
   755 parameter inheritance, in locale declarations, parameters that are not
   756 'touched' (instantiation position "_" or omitted) are implicitly added
   757 with their syntax at the beginning of the for clause.
   758 
   759 - Syntax from abbreviations and definitions in locales is available in
   760 locale expressions and context elements.  The latter is particularly
   761 useful in locale declarations.
   762 
   763 - More flexible mechanisms to qualify names generated by locale
   764 expressions.  Qualifiers (prefixes) may be specified in locale
   765 expressions, and can be marked as mandatory (syntax: "name!:") or
   766 optional (syntax "name?:").  The default depends for plain "name:"
   767 depends on the situation where a locale expression is used: in
   768 commands 'locale' and 'sublocale' prefixes are optional, in
   769 'interpretation' and 'interpret' prefixes are mandatory.  The old
   770 implicit qualifiers derived from the parameter names of a locale are
   771 no longer generated.
   772 
   773 - Command "sublocale l < e" replaces "interpretation l < e".  The
   774 instantiation clause in "interpretation" and "interpret" (square
   775 brackets) is no longer available.  Use locale expressions.
   776 
   777 - When converting proof scripts, mandatory qualifiers in
   778 'interpretation' and 'interpret' should be retained by default, even
   779 if this is an INCOMPATIBILITY compared to former behavior.  In the
   780 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   781 in locale expressions range over a single locale instance only.
   782 
   783 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   784 In existing theorem specifications replace the includes element by the
   785 respective context elements of the included locale, omitting those
   786 that are already present in the theorem specification.  Multiple
   787 assume elements of a locale should be replaced by a single one
   788 involving the locale predicate.  In the proof body, declarations (most
   789 notably theorems) may be regained by interpreting the respective
   790 locales in the proof context as required (command "interpret").
   791 
   792 If using "includes" in replacement of a target solely because the
   793 parameter types in the theorem are not as general as in the target,
   794 consider declaring a new locale with additional type constraints on
   795 the parameters (context element "constrains").
   796 
   797 - Discontinued "locale (open)".  INCOMPATIBILITY.
   798 
   799 - Locale interpretation commands no longer attempt to simplify goal.
   800 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   801 methods intro_locales and unfold_locales to clarify.
   802 
   803 - Locale interpretation commands no longer accept interpretation
   804 attributes.  INCOMPATIBILITY.
   805 
   806 * Class declaration: so-called "base sort" must not be given in import
   807 list any longer, but is inferred from the specification.  Particularly
   808 in HOL, write
   809 
   810     class foo = ...
   811 
   812 instead of
   813 
   814     class foo = type + ...
   815 
   816 * Class target: global versions of theorems stemming do not carry a
   817 parameter prefix any longer.  INCOMPATIBILITY.
   818 
   819 * Class 'instance' command no longer accepts attached definitions.
   820 INCOMPATIBILITY, use proper 'instantiation' target instead.
   821 
   822 * Recovered hiding of consts, which was accidentally broken in
   823 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   824 makes c inaccessible; consider using ``hide (open) const c'' instead.
   825 
   826 * Slightly more coherent Pure syntax, with updated documentation in
   827 isar-ref manual.  Removed locales meta_term_syntax and
   828 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   829 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   830 directly in regular applications.
   831 
   832 * There is a new syntactic category "float_const" for signed decimal
   833 fractions (e.g. 123.45 or -123.45).
   834 
   835 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   836 interface with 'setup' command instead.
   837 
   838 * Command 'local_setup' is similar to 'setup', but operates on a local
   839 theory context.
   840 
   841 * The 'axiomatization' command now only works within a global theory
   842 context.  INCOMPATIBILITY.
   843 
   844 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   845 hypotheses.  Sorts required in the course of reasoning need to be
   846 covered by the constraints in the initial statement, completed by the
   847 type instance information of the background theory.  Non-trivial sort
   848 hypotheses, which rarely occur in practice, may be specified via
   849 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   850 
   851   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   852 
   853 The result contains an implicit sort hypotheses as before --
   854 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   855 normalization.
   856 
   857 * Generalized Isar history, with support for linear undo, direct state
   858 addressing etc.
   859 
   860 * Changed defaults for unify configuration options:
   861 
   862   unify_trace_bound = 50 (formerly 25)
   863   unify_search_bound = 60 (formerly 30)
   864 
   865 * Different bookkeeping for code equations (INCOMPATIBILITY):
   866 
   867   a) On theory merge, the last set of code equations for a particular
   868      constant is taken (in accordance with the policy applied by other
   869      parts of the code generator framework).
   870 
   871   b) Code equations stemming from explicit declarations (e.g. code
   872      attribute) gain priority over default code equations stemming
   873      from definition, primrec, fun etc.
   874 
   875 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   876 
   877 * Unified theorem tables for both code generators.  Thus [code
   878 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   879 
   880 * Command 'find_consts' searches for constants based on type and name
   881 patterns, e.g.
   882 
   883     find_consts "_ => bool"
   884 
   885 By default, matching is against subtypes, but it may be restricted to
   886 the whole type.  Searching by name is possible.  Multiple queries are
   887 conjunctive and queries may be negated by prefixing them with a
   888 hyphen:
   889 
   890     find_consts strict: "_ => bool" name: "Int" -"int => int"
   891 
   892 * New 'find_theorems' criterion "solves" matches theorems that
   893 directly solve the current goal (modulo higher-order unification).
   894 
   895 * Auto solve feature for main theorem statements: whenever a new goal
   896 is stated, "find_theorems solves" is called; any theorems that could
   897 solve the lemma directly are listed as part of the goal state.
   898 Cf. associated options in Proof General Isabelle settings menu,
   899 enabled by default, with reasonable timeout for pathological cases of
   900 higher-order unification.
   901 
   902 
   903 *** Document preparation ***
   904 
   905 * Antiquotation @{lemma} now imitates a regular terminal proof,
   906 demanding keyword 'by' and supporting the full method expression
   907 syntax just like the Isar command 'by'.
   908 
   909 
   910 *** HOL ***
   911 
   912 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   913 points Main and Complex_Main remain as before.
   914 
   915 * Logic image HOL-Plain provides a minimal HOL with the most important
   916 tools available (inductive, datatype, primrec, ...).  This facilitates
   917 experimentation and tool development.  Note that user applications
   918 (and library theories) should never refer to anything below theory
   919 Main, as before.
   920 
   921 * Logic image HOL-Main stops at theory Main, and thus facilitates
   922 experimentation due to shorter build times.
   923 
   924 * Logic image HOL-NSA contains theories of nonstandard analysis which
   925 were previously part of former HOL-Complex.  Entry point Hyperreal
   926 remains valid, but theories formerly using Complex_Main should now use
   927 new entry point Hypercomplex.
   928 
   929 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   930 Posix processes.  Avoids potentially expensive forking of the ML
   931 process.  New thread-based implementation also works on non-Unix
   932 platforms (Cygwin).  Provers are no longer hardwired, but defined
   933 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   934 commands are covered in the isar-ref manual.
   935 
   936 * Wrapper scripts for remote SystemOnTPTP service allows to use
   937 sledgehammer without local ATP installation (Vampire etc.). Other
   938 provers may be included via suitable ML wrappers, see also
   939 src/HOL/ATP_Linkup.thy.
   940 
   941 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   942 menu.
   943 
   944 * The metis method no longer fails because the theorem is too trivial
   945 (contains the empty clause).
   946 
   947 * The metis method now fails in the usual manner, rather than raising
   948 an exception, if it determines that it cannot prove the theorem.
   949 
   950 * Method "coherent" implements a prover for coherent logic (see also
   951 src/Tools/coherent.ML).
   952 
   953 * Constants "undefined" and "default" replace "arbitrary".  Usually
   954 "undefined" is the right choice to replace "arbitrary", though
   955 logically there is no difference.  INCOMPATIBILITY.
   956 
   957 * Command "value" now integrates different evaluation mechanisms.  The
   958 result of the first successful evaluation mechanism is printed.  In
   959 square brackets a particular named evaluation mechanisms may be
   960 specified (currently, [SML], [code] or [nbe]).  See further
   961 src/HOL/ex/Eval_Examples.thy.
   962 
   963 * Normalization by evaluation now allows non-leftlinear equations.
   964 Declare with attribute [code nbe].
   965 
   966 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   967 as the structured Isar versions "cases" and "induct", cf. the
   968 corresponding "cases" and "induct" attributes.  Mutual induction rules
   969 are now presented as a list of individual projections
   970 (e.g. foo_bar.inducts for types foo and bar); the old format with
   971 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   972 rare situations a different rule is selected --- notably nested tuple
   973 elimination instead of former prod.exhaust: use explicit (case_tac t
   974 rule: prod.exhaust) here.
   975 
   976 * Attributes "cases", "induct", "coinduct" support "del" option.
   977 
   978 * Removed fact "case_split_thm", which duplicates "case_split".
   979 
   980 * The option datatype has been moved to a new theory Option.  Renamed
   981 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   982 
   983 * New predicate "strict_mono" classifies strict functions on partial
   984 orders.  With strict functions on linear orders, reasoning about
   985 (in)equalities is facilitated by theorems "strict_mono_eq",
   986 "strict_mono_less_eq" and "strict_mono_less".
   987 
   988 * Some set operations are now proper qualified constants with
   989 authentic syntax.  INCOMPATIBILITY:
   990 
   991     op Int ~>   Set.Int
   992     op Un ~>    Set.Un
   993     INTER ~>    Set.INTER
   994     UNION ~>    Set.UNION
   995     Inter ~>    Set.Inter
   996     Union ~>    Set.Union
   997     {} ~>       Set.empty
   998     UNIV ~>     Set.UNIV
   999 
  1000 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1001 theory Set.
  1002 
  1003 * Auxiliary class "itself" has disappeared -- classes without any
  1004 parameter are treated as expected by the 'class' command.
  1005 
  1006 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1007 
  1008 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1009 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1010 
  1011 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1012 method "approximation".  It proves formulas on real values by using
  1013 interval arithmetic.  In the formulas are also the transcendental
  1014 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1015 allowed. For examples see
  1016 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1017 
  1018 * Theory "Reflection" now resides in HOL/Library.
  1019 
  1020 * Entry point to Word library now simply named "Word".
  1021 INCOMPATIBILITY.
  1022 
  1023 * Made source layout more coherent with logical distribution
  1024 structure:
  1025 
  1026     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1027     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1028     src/HOL/Library/GCD.thy ~> src/HOL/
  1029     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1030     src/HOL/Library/Parity.thy ~> src/HOL/
  1031     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1032     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1033     src/HOL/Real/Lubs.thy ~> src/HOL/
  1034     src/HOL/Real/PReal.thy ~> src/HOL/
  1035     src/HOL/Real/Rational.thy ~> src/HOL/
  1036     src/HOL/Real/RComplete.thy ~> src/HOL/
  1037     src/HOL/Real/RealDef.thy ~> src/HOL/
  1038     src/HOL/Real/RealPow.thy ~> src/HOL/
  1039     src/HOL/Real/Real.thy ~> src/HOL/
  1040     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1041     src/HOL/Complex/Complex.thy ~> src/HOL/
  1042     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1043     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1044     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1045     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1046     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1047     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1048     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1049     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1050     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1051     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1052     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1053     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1054     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1055     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1056     src/HOL/Real/Float ~> src/HOL/Library/
  1057     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1058     src/HOL/Real/RealVector.thy ~> src/HOL/
  1059 
  1060     src/HOL/arith_data.ML ~> src/HOL/Tools
  1061     src/HOL/hologic.ML ~> src/HOL/Tools
  1062     src/HOL/simpdata.ML ~> src/HOL/Tools
  1063     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1064     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1065     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1066     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1067     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1068     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1069     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1070 
  1071     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1072     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1073     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1074     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1075     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1076     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1077 
  1078 * If methods "eval" and "evaluation" encounter a structured proof
  1079 state with !!/==>, only the conclusion is evaluated to True (if
  1080 possible), avoiding strange error messages.
  1081 
  1082 * Method "sizechange" automates termination proofs using (a
  1083 modification of) the size-change principle.  Requires SAT solver.  See
  1084 src/HOL/ex/Termination.thy for examples.
  1085 
  1086 * Simplifier: simproc for let expressions now unfolds if bound
  1087 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1088 
  1089 * Method "arith": Linear arithmetic now ignores all inequalities when
  1090 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1091 
  1092 * New attribute "arith" for facts that should always be used
  1093 automatically by arithmetic. It is intended to be used locally in
  1094 proofs, e.g.
  1095 
  1096   assumes [arith]: "x > 0"
  1097 
  1098 Global usage is discouraged because of possible performance impact.
  1099 
  1100 * New classes "top" and "bot" with corresponding operations "top" and
  1101 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1102 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1103 
  1104 * Changed definition lemma "less_fun_def" in order to provide an
  1105 instance for preorders on functions; use lemma "less_le" instead.
  1106 INCOMPATIBILITY.
  1107 
  1108 * Theory Orderings: class "wellorder" moved here, with explicit
  1109 induction rule "less_induct" as assumption.  For instantiation of
  1110 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1111 INCOMPATIBILITY.
  1112 
  1113 * Theory Orderings: added class "preorder" as superclass of "order".
  1114 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1115 etc. slightly changed.  Some theorems named order_class.* now named
  1116 preorder_class.*.
  1117 
  1118 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1119 "diag" to "Id_on".
  1120 
  1121 * Theory Finite_Set: added a new fold combinator of type
  1122 
  1123   ('a => 'b => 'b) => 'b => 'a set => 'b
  1124 
  1125 Occasionally this is more convenient than the old fold combinator
  1126 which is now defined in terms of the new one and renamed to
  1127 fold_image.
  1128 
  1129 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1130 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1131 extended with further lemmas!).  At the moment both still exist but
  1132 the former will disappear at some point.
  1133 
  1134 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1135 class recpower.  Type-specific simp rules for various recpower types
  1136 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1137 
  1138 rat_power_0    -> power_0
  1139 rat_power_Suc  -> power_Suc
  1140 realpow_0      -> power_0
  1141 realpow_Suc    -> power_Suc
  1142 complexpow_0   -> power_0
  1143 complexpow_Suc -> power_Suc
  1144 power_poly_0   -> power_0
  1145 power_poly_Suc -> power_Suc
  1146 
  1147 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1148 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1149 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1150 of lemmas from Divides has been generalized from nat to class
  1151 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1152 renames resulting from duplicate elimination:
  1153 
  1154     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1155     zero_dvd_iff ~>         dvd_0_left_iff
  1156     dvd_0 ~>                dvd_0_right
  1157     DIVISION_BY_ZERO_DIV ~> div_by_0
  1158     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1159     mult_div ~>             div_mult_self2_is_id
  1160     mult_mod ~>             mod_mult_self2_is_0
  1161 
  1162 * Theory IntDiv: removed many lemmas that are instances of class-based
  1163 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1164 rename old lemmas as follows:
  1165 
  1166 dvd_diff               -> nat_dvd_diff
  1167 dvd_zminus_iff         -> dvd_minus_iff
  1168 mod_add1_eq            -> mod_add_eq
  1169 mod_mult1_eq           -> mod_mult_right_eq
  1170 mod_mult1_eq'          -> mod_mult_left_eq
  1171 mod_mult_distrib_mod   -> mod_mult_eq
  1172 nat_mod_add_left_eq    -> mod_add_left_eq
  1173 nat_mod_add_right_eq   -> mod_add_right_eq
  1174 nat_mod_div_trivial    -> mod_div_trivial
  1175 nat_mod_mod_trivial    -> mod_mod_trivial
  1176 zdiv_zadd_self1        -> div_add_self1
  1177 zdiv_zadd_self2        -> div_add_self2
  1178 zdiv_zmult_self1       -> div_mult_self2_is_id
  1179 zdiv_zmult_self2       -> div_mult_self1_is_id
  1180 zdvd_triv_left         -> dvd_triv_left
  1181 zdvd_triv_right        -> dvd_triv_right
  1182 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1183 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1184 zmod_zadd_left_eq      -> mod_add_left_eq
  1185 zmod_zadd_right_eq     -> mod_add_right_eq
  1186 zmod_zadd_self1        -> mod_add_self1
  1187 zmod_zadd_self2        -> mod_add_self2
  1188 zmod_zadd1_eq          -> mod_add_eq
  1189 zmod_zdiff1_eq         -> mod_diff_eq
  1190 zmod_zdvd_zmod         -> mod_mod_cancel
  1191 zmod_zmod_cancel       -> mod_mod_cancel
  1192 zmod_zmult_self1       -> mod_mult_self2_is_0
  1193 zmod_zmult_self2       -> mod_mult_self1_is_0
  1194 zmod_1                 -> mod_by_1
  1195 zdiv_1                 -> div_by_1
  1196 zdvd_abs1              -> abs_dvd_iff
  1197 zdvd_abs2              -> dvd_abs_iff
  1198 zdvd_refl              -> dvd_refl
  1199 zdvd_trans             -> dvd_trans
  1200 zdvd_zadd              -> dvd_add
  1201 zdvd_zdiff             -> dvd_diff
  1202 zdvd_zminus_iff        -> dvd_minus_iff
  1203 zdvd_zminus2_iff       -> minus_dvd_iff
  1204 zdvd_zmultD            -> dvd_mult_right
  1205 zdvd_zmultD2           -> dvd_mult_left
  1206 zdvd_zmult_mono        -> mult_dvd_mono
  1207 zdvd_0_right           -> dvd_0_right
  1208 zdvd_0_left            -> dvd_0_left_iff
  1209 zdvd_1_left            -> one_dvd
  1210 zminus_dvd_iff         -> minus_dvd_iff
  1211 
  1212 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1213 
  1214 * The real numbers offer decimal input syntax: 12.34 is translated
  1215 into 1234/10^2. This translation is not reversed upon output.
  1216 
  1217 * Theory Library/Polynomial defines an abstract type 'a poly of
  1218 univariate polynomials with coefficients of type 'a.  In addition to
  1219 the standard ring operations, it also supports div and mod.  Code
  1220 generation is also supported, using list-style constructors.
  1221 
  1222 * Theory Library/Inner_Product defines a class of real_inner for real
  1223 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1224 => real.  Class real_inner is a subclass of real_normed_vector from
  1225 theory RealVector.
  1226 
  1227 * Theory Library/Product_Vector provides instances for the product
  1228 type 'a * 'b of several classes from RealVector and Inner_Product.
  1229 Definitions of addition, subtraction, scalar multiplication, norms,
  1230 and inner products are included.
  1231 
  1232 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1233 addition to the field operations, numerals and case syntax are also
  1234 supported.
  1235 
  1236 * Theory Library/Diagonalize provides constructive version of Cantor's
  1237 first diagonalization argument.
  1238 
  1239 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1240 zlcm (for int); carried together from various gcd/lcm developements in
  1241 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1242 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1243 may recover tupled syntax as follows:
  1244 
  1245     hide (open) const gcd
  1246     abbreviation gcd where
  1247       "gcd == (%(a, b). GCD.gcd a b)"
  1248     notation (output)
  1249       GCD.gcd ("gcd '(_, _')")
  1250 
  1251 The same works for lcm, zgcd, zlcm.
  1252 
  1253 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1254 instantiations for algebraic structures.  Removed some duplicate
  1255 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1256 
  1257 * ML antiquotation @{code} takes a constant as argument and generates
  1258 corresponding code in background and inserts name of the corresponding
  1259 resulting ML value/function/datatype constructor binding in place.
  1260 All occurrences of @{code} with a single ML block are generated
  1261 simultaneously.  Provides a generic and safe interface for
  1262 instrumentalizing code generation.  See
  1263 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1264 In future you ought to refrain from ad-hoc compiling generated SML
  1265 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1266 cannot refer to constants for which user-defined serializations are
  1267 set.  Refer to the corresponding ML counterpart directly in that
  1268 cases.
  1269 
  1270 * Command 'rep_datatype': instead of theorem names the command now
  1271 takes a list of terms denoting the constructors of the type to be
  1272 represented as datatype.  The characteristic theorems have to be
  1273 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1274 have disappeared in favour of existing ones:
  1275 
  1276     unit_induct                 ~> unit.induct
  1277     prod_induct                 ~> prod.induct
  1278     sum_induct                  ~> sum.induct
  1279     Suc_Suc_eq                  ~> nat.inject
  1280     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1281 
  1282 
  1283 *** HOL-Algebra ***
  1284 
  1285 * New locales for orders and lattices where the equivalence relation
  1286 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1287 locales use a record structure with field eq for the equivalence.
  1288 
  1289 * New theory of factorial domains.
  1290 
  1291 * Units_l_inv and Units_r_inv are now simp rules by default.
  1292 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1293 and/or r_inv will now also require deletion of these lemmas.
  1294 
  1295 * Renamed the following theorems, INCOMPATIBILITY:
  1296 
  1297 UpperD ~> Upper_memD
  1298 LowerD ~> Lower_memD
  1299 least_carrier ~> least_closed
  1300 greatest_carrier ~> greatest_closed
  1301 greatest_Lower_above ~> greatest_Lower_below
  1302 one_zero ~> carrier_one_zero
  1303 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1304 
  1305 
  1306 *** HOL-Nominal ***
  1307 
  1308 * Nominal datatypes can now contain type-variables.
  1309 
  1310 * Commands 'nominal_inductive' and 'equivariance' work with local
  1311 theory targets.
  1312 
  1313 * Nominal primrec can now works with local theory targets and its
  1314 specification syntax now conforms to the general format as seen in
  1315 'inductive' etc.
  1316 
  1317 * Method "perm_simp" honours the standard simplifier attributes
  1318 (no_asm), (no_asm_use) etc.
  1319 
  1320 * The new predicate #* is defined like freshness, except that on the
  1321 left hand side can be a set or list of atoms.
  1322 
  1323 * Experimental command 'nominal_inductive2' derives strong induction
  1324 principles for inductive definitions.  In contrast to
  1325 'nominal_inductive', which can only deal with a fixed number of
  1326 binders, it can deal with arbitrary expressions standing for sets of
  1327 atoms to be avoided.  The only inductive definition we have at the
  1328 moment that needs this generalisation is the typing rule for Lets in
  1329 the algorithm W:
  1330 
  1331  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1332  -----------------------------------------------------------------
  1333          Gamma |- Let x be t1 in t2 : T2
  1334 
  1335 In this rule one wants to avoid all the binders that are introduced by
  1336 "close Gamma T1".  We are looking for other examples where this
  1337 feature might be useful.  Please let us know.
  1338 
  1339 
  1340 *** HOLCF ***
  1341 
  1342 * Reimplemented the simplification procedure for proving continuity
  1343 subgoals.  The new simproc is extensible; users can declare additional
  1344 continuity introduction rules with the attribute [cont2cont].
  1345 
  1346 * The continuity simproc now uses a different introduction rule for
  1347 solving continuity subgoals on terms with lambda abstractions.  In
  1348 some rare cases the new simproc may fail to solve subgoals that the
  1349 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1350 Potential INCOMPATIBILITY.
  1351 
  1352 * Command 'fixrec': specification syntax now conforms to the general
  1353 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1354 examples.  INCOMPATIBILITY.
  1355 
  1356 
  1357 *** ZF ***
  1358 
  1359 * Proof of Zorn's Lemma for partial orders.
  1360 
  1361 
  1362 *** ML ***
  1363 
  1364 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1365 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1366 depends on multithreading, so timouts will not work before Poly/ML
  1367 5.2.1!
  1368 
  1369 * High-level support for concurrent ML programming, see
  1370 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1371 particularly convenient to organize independent functional
  1372 computations.  The concept of "synchronized variables" provides a
  1373 higher-order interface for components with shared state, avoiding the
  1374 delicate details of mutexes and condition variables.  (Requires
  1375 Poly/ML 5.2.1 or later.)
  1376 
  1377 * ML bindings produced via Isar commands are stored within the Isar
  1378 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1379 become thread-safe and work with undo as expected (concerning
  1380 top-level bindings, not side-effects on global references).
  1381 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1382 compiler at runtime; really global bindings need to be given outside a
  1383 theory.  (Requires Poly/ML 5.2 or later.)
  1384 
  1385 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1386 context.  Top-level ML bindings are stored within the proof context in
  1387 a purely sequential fashion, disregarding the nested proof structure.
  1388 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1389 proof.  (Requires Poly/ML 5.2 or later.)
  1390 
  1391 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1392 and Method.setup, as well as Isar commands 'attribute_setup' and
  1393 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1394 existing code accordingly, or use plain 'setup' together with old
  1395 Method.add_method.
  1396 
  1397 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1398 to 'a -> thm, while results are always tagged with an authentic oracle
  1399 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1400 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1401 accordingly.  Note that extra performance may be gained by producing
  1402 the cterm carefully, avoiding slow Thm.cterm_of.
  1403 
  1404 * Simplified interface for defining document antiquotations via
  1405 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1406 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1407 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1408 examples.
  1409 
  1410 * More systematic treatment of long names, abstract name bindings, and
  1411 name space operations.  Basic operations on qualified names have been
  1412 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1413 Long_Name.append.  Old type bstring has been mostly replaced by
  1414 abstract type binding (see structure Binding), which supports precise
  1415 qualification by packages and local theory targets, as well as proper
  1416 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1417 bstring values into Binding.name, or better pass through abstract
  1418 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1419 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1420 
  1421 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1422 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1423 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1424 
  1425 * Disposed old type and term read functions (Sign.read_def_typ,
  1426 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1427 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1428 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1429 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1430 resort for legacy applications.
  1431 
  1432 * Disposed old declarations, tactics, tactic combinators that refer to
  1433 the simpset or claset of an implicit theory (such as Addsimps,
  1434 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1435 embedded ML text, or local_simpset_of with a proper context passed as
  1436 explicit runtime argument.
  1437 
  1438 * Rules and tactics that read instantiations (read_instantiate,
  1439 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1440 context, which is required for parsing and type-checking.  Moreover,
  1441 the variables are specified as plain indexnames, not string encodings
  1442 thereof.  INCOMPATIBILITY.
  1443 
  1444 * Generic Toplevel.add_hook interface allows to analyze the result of
  1445 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1446 for theorem dependency output of transactions resulting in a new
  1447 theory state.
  1448 
  1449 * ML antiquotations: block-structured compilation context indicated by
  1450 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1451 
  1452   @{binding name}                         - basic name binding
  1453   @{let ?pat = term}                      - term abbreviation (HO matching)
  1454   @{note name = fact}                     - fact abbreviation
  1455   @{thm fact}                             - singleton fact (with attributes)
  1456   @{thms fact}                            - general fact (with attributes)
  1457   @{lemma prop by method}                 - singleton goal
  1458   @{lemma prop by meth1 meth2}            - singleton goal
  1459   @{lemma prop1 ... propN by method}      - general goal
  1460   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1461   @{lemma (open) ...}                     - open derivation
  1462 
  1463 
  1464 *** System ***
  1465 
  1466 * The Isabelle "emacs" tool provides a specific interface to invoke
  1467 Proof General / Emacs, with more explicit failure if that is not
  1468 installed (the old isabelle-interface script silently falls back on
  1469 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1470 installation location of the Proof General distribution.
  1471 
  1472 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1473 the Isabelle process into a JVM/Scala application.  See
  1474 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1475 process wrapper has been discontinued.)
  1476 
  1477 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1478 
  1479 * Various status messages (with exact source position information) are
  1480 emitted, if proper markup print mode is enabled.  This allows
  1481 user-interface components to provide detailed feedback on internal
  1482 prover operations.
  1483 
  1484 
  1485 
  1486 New in Isabelle2008 (June 2008)
  1487 -------------------------------
  1488 
  1489 *** General ***
  1490 
  1491 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1492 and updated, with formally checked references as hyperlinks.
  1493 
  1494 * Theory loader: use_thy (and similar operations) no longer set the
  1495 implicit ML context, which was occasionally hard to predict and in
  1496 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1497 provides a proper context already.
  1498 
  1499 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1500 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1501 'use' within a theory file will do the job.
  1502 
  1503 * Name space merge now observes canonical order, i.e. the second space
  1504 is inserted into the first one, while existing entries in the first
  1505 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1506 swap theory imports.
  1507 
  1508 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1509 INCOMPATIBILITY in identifier syntax etc.
  1510 
  1511 * Outer syntax: string tokens no longer admit escaped white space,
  1512 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1513 white space without escapes.
  1514 
  1515 * Outer syntax: string tokens may contain arbitrary character codes
  1516 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1517 "foo_bar".
  1518 
  1519 
  1520 *** Pure ***
  1521 
  1522 * Context-dependent token translations.  Default setup reverts locally
  1523 fixed variables, and adds hilite markup for undeclared frees.
  1524 
  1525 * Unused theorems can be found using the new command 'unused_thms'.
  1526 There are three ways of invoking it:
  1527 
  1528 (1) unused_thms
  1529      Only finds unused theorems in the current theory.
  1530 
  1531 (2) unused_thms thy_1 ... thy_n -
  1532      Finds unused theorems in the current theory and all of its ancestors,
  1533      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1534 
  1535 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1536      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1537      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1538      their ancestors.
  1539 
  1540 In order to increase the readability of the list produced by
  1541 unused_thms, theorems that have been created by a particular instance
  1542 of a theory command such as 'inductive' or 'function' are considered
  1543 to belong to the same "group", meaning that if at least one theorem in
  1544 this group is used, the other theorems in the same group are no longer
  1545 reported as unused.  Moreover, if all theorems in the group are
  1546 unused, only one theorem in the group is displayed.
  1547 
  1548 Note that proof objects have to be switched on in order for
  1549 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1550 usually the case when using Proof General with the default settings).
  1551 
  1552 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1553 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1554 duplicate fact bindings, or even accidental fact duplications.  Note
  1555 that tools may maintain dynamically scoped facts systematically, using
  1556 PureThy.add_thms_dynamic.
  1557 
  1558 * Command 'hide' now allows to hide from "fact" name space as well.
  1559 
  1560 * Eliminated destructive theorem database, simpset, claset, and
  1561 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1562 update of theories within ML code.
  1563 
  1564 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1565 INCOMPATIBILITY, object-logics depending on former Pure require
  1566 additional setup PureThy.old_appl_syntax_setup; object-logics
  1567 depending on former CPure need to refer to Pure.
  1568 
  1569 * Commands 'use' and 'ML' are now purely functional, operating on
  1570 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1571 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1572 INCOMPATIBILITY.
  1573 
  1574 * Command 'setup': discontinued implicit version with ML reference.
  1575 
  1576 * Instantiation target allows for simultaneous specification of class
  1577 instance operations together with an instantiation proof.
  1578 Type-checking phase allows to refer to class operations uniformly.
  1579 See src/HOL/Complex/Complex.thy for an Isar example and
  1580 src/HOL/Library/Eval.thy for an ML example.
  1581 
  1582 * Indexing of literal facts: be more serious about including only
  1583 facts from the visible specification/proof context, but not the
  1584 background context (locale etc.).  Affects `prop` notation and method
  1585 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1586 situations.
  1587 
  1588 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1589 "(open)" option, which used to expose internal bound variables to the
  1590 proof text.
  1591 
  1592 * Isar statements: removed obsolete case "rule_context".
  1593 INCOMPATIBILITY, better use explicit fixes/assumes.
  1594 
  1595 * Locale proofs: default proof step now includes 'unfold_locales';
  1596 hence 'proof' without argument may be used to unfold locale
  1597 predicates.
  1598 
  1599 
  1600 *** Document preparation ***
  1601 
  1602 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1603 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1604 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1605 spot); renamed link color from "darkblue" to "linkcolor" (default
  1606 value unchanged, can be redefined via \definecolor); no longer sets
  1607 "a4paper" option (unnecessary or even intrusive).
  1608 
  1609 * Antiquotation @{lemma A method} proves proposition A by the given
  1610 method (either a method name or a method name plus (optional) method
  1611 arguments in parentheses) and prints A just like @{prop A}.
  1612 
  1613 
  1614 *** HOL ***
  1615 
  1616 * New primrec package.  Specification syntax conforms in style to
  1617 definition/function/....  No separate induction rule is provided.  The
  1618 "primrec" command distinguishes old-style and new-style specifications
  1619 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1620 When adjusting theories, beware: constants stemming from new-style
  1621 primrec specifications have authentic syntax.
  1622 
  1623 * Metis prover is now an order of magnitude faster, and also works
  1624 with multithreading.
  1625 
  1626 * Metis: the maximum number of clauses that can be produced from a
  1627 theorem is now given by the attribute max_clauses.  Theorems that
  1628 exceed this number are ignored, with a warning printed.
  1629 
  1630 * Sledgehammer no longer produces structured proofs by default. To
  1631 enable, declare [[sledgehammer_full = true]].  Attributes
  1632 reconstruction_modulus, reconstruction_sorts renamed
  1633 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1634 
  1635 * Method "induct_scheme" derives user-specified induction rules
  1636 from well-founded induction and completeness of patterns. This factors
  1637 out some operations that are done internally by the function package
  1638 and makes them available separately.  See
  1639 src/HOL/ex/Induction_Scheme.thy for examples.
  1640 
  1641 * More flexible generation of measure functions for termination
  1642 proofs: Measure functions can be declared by proving a rule of the
  1643 form "is_measure f" and giving it the [measure_function] attribute.
  1644 The "is_measure" predicate is logically meaningless (always true), and
  1645 just guides the heuristic.  To find suitable measure functions, the
  1646 termination prover sets up the goal "is_measure ?f" of the appropriate
  1647 type and generates all solutions by prolog-style backwards proof using
  1648 the declared rules.
  1649 
  1650 This setup also deals with rules like 
  1651 
  1652   "is_measure f ==> is_measure (list_size f)"
  1653 
  1654 which accommodates nested datatypes that recurse through lists.
  1655 Similar rules are predeclared for products and option types.
  1656 
  1657 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1658 
  1659   INCOMPATIBILITIES:
  1660 
  1661   - Definitions of overloaded constants on sets have to be replaced by
  1662     definitions on => and bool.
  1663 
  1664   - Some definitions of overloaded operators on sets can now be proved
  1665     using the definitions of the operators on => and bool.  Therefore,
  1666     the following theorems have been renamed:
  1667 
  1668       subset_def   -> subset_eq
  1669       psubset_def  -> psubset_eq
  1670       set_diff_def -> set_diff_eq
  1671       Compl_def    -> Compl_eq
  1672       Sup_set_def  -> Sup_set_eq
  1673       Inf_set_def  -> Inf_set_eq
  1674       sup_set_def  -> sup_set_eq
  1675       inf_set_def  -> inf_set_eq
  1676 
  1677   - Due to the incompleteness of the HO unification algorithm, some
  1678     rules such as subst may require manual instantiation, if some of
  1679     the unknowns in the rule is a set.
  1680 
  1681   - Higher order unification and forward proofs:
  1682     The proof pattern
  1683 
  1684       have "P (S::'a set)" <...>
  1685       then have "EX S. P S" ..
  1686 
  1687     no longer works (due to the incompleteness of the HO unification
  1688     algorithm) and must be replaced by the pattern
  1689 
  1690       have "EX S. P S"
  1691       proof
  1692         show "P S" <...>
  1693       qed
  1694 
  1695   - Calculational reasoning with subst (or similar rules):
  1696     The proof pattern
  1697 
  1698       have "P (S::'a set)" <...>
  1699       also have "S = T" <...>
  1700       finally have "P T" .
  1701 
  1702     no longer works (for similar reasons as the previous example) and
  1703     must be replaced by something like
  1704 
  1705       have "P (S::'a set)" <...>
  1706       moreover have "S = T" <...>
  1707       ultimately have "P T" by simp
  1708 
  1709   - Tactics or packages written in ML code:
  1710     Code performing pattern matching on types via
  1711 
  1712       Type ("set", [T]) => ...
  1713 
  1714     must be rewritten. Moreover, functions like strip_type or
  1715     binder_types no longer return the right value when applied to a
  1716     type of the form
  1717 
  1718       T1 => ... => Tn => U => bool
  1719 
  1720     rather than
  1721 
  1722       T1 => ... => Tn => U set
  1723 
  1724 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1725 Wellfounded_Relations to theory Wellfounded.
  1726 
  1727 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1728 
  1729 * Class finite no longer treats UNIV as class parameter.  Use class
  1730 enum from theory Library/Enum instead to achieve a similar effect.
  1731 INCOMPATIBILITY.
  1732 
  1733 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1734 and "Cons".  INCOMPATIBILITY.
  1735 
  1736 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1737 Potential INCOMPATIBILITY.
  1738 
  1739 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1740 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1741 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1742 
  1743 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1744 the same name in theory Orderings:
  1745 
  1746   less_trans
  1747   less_linear
  1748   le_imp_less_or_eq
  1749   le_less_trans
  1750   less_le_trans
  1751   less_not_sym
  1752   less_asym
  1753 
  1754 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1755 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1756 and different variable names.
  1757 
  1758 * Library/Option_ord.thy: Canonical order on option type.
  1759 
  1760 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1761 finite maps.
  1762 
  1763 * Library/Countable.thy: Type class for countable types.
  1764 
  1765 * Theory Int: The representation of numerals has changed.  The infix
  1766 operator BIT and the bit datatype with constructors B0 and B1 have
  1767 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1768 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1769 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1770 accordingly.
  1771 
  1772 * Theory Nat: definition of <= and < on natural numbers no longer
  1773 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1774 le_def and less_def have disappeared.  Consider lemmas not_less
  1775 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1776 
  1777 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1778 (whose purpose mainly is for various fold_set functionals) have been
  1779 abandoned in favor of the existing algebraic classes
  1780 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1781 lower_semilattice (resp. upper_semilattice) and linorder.
  1782 INCOMPATIBILITY.
  1783 
  1784 * Theory Transitive_Closure: induct and cases rules now declare proper
  1785 case_names ("base" and "step").  INCOMPATIBILITY.
  1786 
  1787 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1788 lattices.  The form set-specific version is available as
  1789 Inductive.lfp_ordinal_induct_set.
  1790 
  1791 * Renamed theorems "power.simps" to "power_int.simps".
  1792 INCOMPATIBILITY.
  1793 
  1794 * Class semiring_div provides basic abstract properties of semirings
  1795 with division and modulo operations.  Subsumes former class dvd_mod.
  1796 
  1797 * Merged theories IntDef, Numeral and IntArith into unified theory
  1798 Int.  INCOMPATIBILITY.
  1799 
  1800 * Theory Library/Code_Index: type "index" now represents natural
  1801 numbers rather than integers.  INCOMPATIBILITY.
  1802 
  1803 * New class "uminus" with operation "uminus" (split of from class
  1804 "minus" which now only has operation "minus", binary).
  1805 INCOMPATIBILITY.
  1806 
  1807 * Constants "card", "internal_split", "option_map" now with authentic
  1808 syntax.  INCOMPATIBILITY.
  1809 
  1810 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1811 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1812 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1813 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1814 Sup_set_def, le_def, less_def, option_map_def now with object
  1815 equality.  INCOMPATIBILITY.
  1816 
  1817 * Records. Removed K_record, and replaced it by pure lambda term
  1818 %x. c. The simplifier setup is now more robust against eta expansion.
  1819 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1820 
  1821 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1822 
  1823 * Library/ListVector: new theory of arithmetic vector operations.
  1824 
  1825 * Library/Order_Relation: new theory of various orderings as sets of
  1826 pairs.  Defines preorders, partial orders, linear orders and
  1827 well-orders on sets and on types.
  1828 
  1829 
  1830 *** ZF ***
  1831 
  1832 * Renamed some theories to allow to loading both ZF and HOL in the
  1833 same session:
  1834 
  1835   Datatype  -> Datatype_ZF
  1836   Inductive -> Inductive_ZF
  1837   Int       -> Int_ZF
  1838   IntDiv    -> IntDiv_ZF
  1839   Nat       -> Nat_ZF
  1840   List      -> List_ZF
  1841   Main      -> Main_ZF
  1842 
  1843 INCOMPATIBILITY: ZF theories that import individual theories below
  1844 Main might need to be adapted.  Regular theory Main is still
  1845 available, as trivial extension of Main_ZF.
  1846 
  1847 
  1848 *** ML ***
  1849 
  1850 * ML within Isar: antiquotation @{const name} or @{const
  1851 name(typargs)} produces statically-checked Const term.
  1852 
  1853 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1854 (of the same name).  Removed obsolete print command.
  1855 
  1856 * Removed obsolete "use_legacy_bindings" function.
  1857 
  1858 * The ``print mode'' is now a thread-local value derived from a global
  1859 template (the former print_mode reference), thus access becomes
  1860 non-critical.  The global print_mode reference is for session
  1861 management only; user-code should use print_mode_value,
  1862 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1863 
  1864 * Functions system/system_out provide a robust way to invoke external
  1865 shell commands, with propagation of interrupts (requires Poly/ML
  1866 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1867 
  1868 
  1869 *** System ***
  1870 
  1871 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1872 in accordance with Proof General 3.7, which prefers GNU emacs.
  1873 
  1874 * isatool tty runs Isabelle process with plain tty interaction;
  1875 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1876 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1877 
  1878 * isatool browser now works with Cygwin as well, using general
  1879 "javapath" function defined in Isabelle process environment.
  1880 
  1881 * YXML notation provides a simple and efficient alternative to
  1882 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1883 isatool yxml as described in the Isabelle system manual.
  1884 
  1885 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1886 provides general wrapper for managing an Isabelle process in a robust
  1887 fashion, with ``cooked'' output from stdin/stderr.
  1888 
  1889 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1890 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1891 
  1892 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1893 way of changing the user's settings is via
  1894 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1895 script.
  1896 
  1897 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1898 cores of the underlying machine, which is a good starting point for
  1899 optimal performance tuning.  The corresponding usedir option -M allows
  1900 "max" as an alias for "0".  WARNING: does not work on certain versions
  1901 of Mac OS (with Poly/ML 5.1).
  1902 
  1903 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1904 adverse effect of Isabelle flooding interactive front-ends (notably
  1905 ProofGeneral / XEmacs).
  1906 
  1907 
  1908 
  1909 New in Isabelle2007 (November 2007)
  1910 -----------------------------------
  1911 
  1912 *** General ***
  1913 
  1914 * More uniform information about legacy features, notably a
  1915 warning/error of "Legacy feature: ...", depending on the state of the
  1916 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1917 legacy features will disappear eventually.
  1918 
  1919 * Theory syntax: the header format ``theory A = B + C:'' has been
  1920 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1921 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1922 
  1923 * Theory syntax: the old non-Isar theory file format has been
  1924 discontinued altogether.  Note that ML proof scripts may still be used
  1925 with Isar theories; migration is usually quite simple with the ML
  1926 function use_legacy_bindings.  INCOMPATIBILITY.
  1927 
  1928 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1929 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1930 quotes.
  1931 
  1932 * Theory loader: be more serious about observing the static theory
  1933 header specifications (including optional directories), but not the
  1934 accidental file locations of previously successful loads.  The strict
  1935 update policy of former update_thy is now already performed by
  1936 use_thy, so the former has been removed; use_thys updates several
  1937 theories simultaneously, just as 'imports' within a theory header
  1938 specification, but without merging the results.  Potential
  1939 INCOMPATIBILITY: may need to refine theory headers and commands
  1940 ROOT.ML which depend on load order.
  1941 
  1942 * Theory loader: optional support for content-based file
  1943 identification, instead of the traditional scheme of full physical
  1944 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1945 (cf. the system manual).  The new scheme allows to work with
  1946 non-finished theories in persistent session images, such that source
  1947 files may be moved later on without requiring reloads.
  1948 
  1949 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1950 file (with the same base name as the theory) are considered a legacy
  1951 feature, which will disappear eventually. Even now, the theory loader
  1952 no longer maintains dependencies on such files.
  1953 
  1954 * Syntax: the scope for resolving ambiguities via type-inference is
  1955 now limited to individual terms, instead of whole simultaneous
  1956 specifications as before. This greatly reduces the complexity of the
  1957 syntax module and improves flexibility by separating parsing and
  1958 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1959 'fixes' etc.) are required in rare situations.
  1960 
  1961 * Syntax: constants introduced by new-style packages ('definition',
  1962 'abbreviation' etc.) are passed through the syntax module in
  1963 ``authentic mode''. This means that associated mixfix annotations
  1964 really stick to such constants, independently of potential name space
  1965 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1966 trees are represented slightly differently, may need to adapt syntax
  1967 translations accordingly. Use CONST marker in 'translations' and
  1968 @{const_syntax} antiquotation in 'parse_translation' etc.
  1969 
  1970 * Legacy goal package: reduced interface to the bare minimum required
  1971 to keep existing proof scripts running.  Most other user-level
  1972 functions are now part of the OldGoals structure, which is *not* open
  1973 by default (consider isatool expandshort before open OldGoals).
  1974 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1975 these tend to cause confusion about the actual goal (!) context being
  1976 used here, which is not necessarily the same as the_context().
  1977 
  1978 * Command 'find_theorems': supports "*" wild-card in "name:"
  1979 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1980 support a specific search form (see ProofGeneral/CHANGES).
  1981 
  1982 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1983 by default, which means that "prems" (and also "fixed variables") are
  1984 suppressed from proof state output.  Note that the ProofGeneral
  1985 settings mechanism allows to change and save options persistently, but
  1986 older versions of Isabelle will fail to start up if a negative prems
  1987 limit is imposed.
  1988 
  1989 * Local theory targets may be specified by non-nested blocks of
  1990 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1991 contain definitions, theorems etc., including any derived mechanism
  1992 that has been implemented on top of these primitives.  This concept
  1993 generalizes the existing ``theorem (in ...)'' towards more versatility
  1994 and scalability.
  1995 
  1996 * Proof General interface: proper undo of final 'end' command;
  1997 discontinued Isabelle/classic mode (ML proof scripts).
  1998 
  1999 
  2000 *** Document preparation ***
  2001 
  2002 * Added antiquotation @{theory name} which prints the given name,
  2003 after checking that it refers to a valid ancestor theory in the
  2004 current context.
  2005 
  2006 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2007 check the given source text as ML type/structure, printing verbatim.
  2008 
  2009 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2010 "c args == rhs" given in the current context.  (Any number of
  2011 arguments may be given on the LHS.)
  2012 
  2013 
  2014 *** Pure ***
  2015 
  2016 * The 'class' package offers a combination of axclass and locale to
  2017 achieve Haskell-like type classes in Isabelle.  Definitions and
  2018 theorems within a class context produce both relative results (with
  2019 implicit parameters according to the locale context), and polymorphic
  2020 constants with qualified polymorphism (according to the class
  2021 context).  Within the body context of a 'class' target, a separate
  2022 syntax layer ("user space type system") takes care of converting
  2023 between global polymorphic consts and internal locale representation.
  2024 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2025 "isatool doc classes" provides a tutorial.
  2026 
  2027 * Generic code generator framework allows to generate executable
  2028 code for ML and Haskell (including Isabelle classes).  A short usage
  2029 sketch:
  2030 
  2031     internal compilation:
  2032         export_code <list of constants (term syntax)> in SML
  2033     writing SML code to a file:
  2034         export_code <list of constants (term syntax)> in SML <filename>
  2035     writing OCaml code to a file:
  2036         export_code <list of constants (term syntax)> in OCaml <filename>
  2037     writing Haskell code to a bunch of files:
  2038         export_code <list of constants (term syntax)> in Haskell <filename>
  2039 
  2040     evaluating closed propositions to True/False using code generation:
  2041         method ``eval''
  2042 
  2043 Reasonable default setup of framework in HOL.
  2044 
  2045 Theorem attributs for selecting and transforming function equations theorems:
  2046 
  2047     [code fun]:        select a theorem as function equation for a specific constant
  2048     [code fun del]:    deselect a theorem as function equation for a specific constant
  2049     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2050     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2051 
  2052 User-defined serializations (target in {SML, OCaml, Haskell}):
  2053 
  2054     code_const <and-list of constants (term syntax)>
  2055       {(target) <and-list of const target syntax>}+
  2056 
  2057     code_type <and-list of type constructors>
  2058       {(target) <and-list of type target syntax>}+
  2059 
  2060     code_instance <and-list of instances>
  2061       {(target)}+
  2062         where instance ::= <type constructor> :: <class>
  2063 
  2064     code_class <and_list of classes>
  2065       {(target) <and-list of class target syntax>}+
  2066         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2067 
  2068 code_instance and code_class only are effective to target Haskell.
  2069 
  2070 For example usage see src/HOL/ex/Codegenerator.thy and
  2071 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2072 generation from Isabelle/HOL theories is available via "isatool doc
  2073 codegen".
  2074 
  2075 * Code generator: consts in 'consts_code' Isar commands are now
  2076 referred to by usual term syntax (including optional type
  2077 annotations).
  2078 
  2079 * Command 'no_translations' removes translation rules from theory
  2080 syntax.
  2081 
  2082 * Overloaded definitions are now actually checked for acyclic
  2083 dependencies.  The overloading scheme is slightly more general than
  2084 that of Haskell98, although Isabelle does not demand an exact
  2085 correspondence to type class and instance declarations.
  2086 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2087 exotic versions of overloading -- at the discretion of the user!
  2088 
  2089 Polymorphic constants are represented via type arguments, i.e. the
  2090 instantiation that matches an instance against the most general
  2091 declaration given in the signature.  For example, with the declaration
  2092 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2093 as c(nat).  Overloading is essentially simultaneous structural
  2094 recursion over such type arguments.  Incomplete specification patterns
  2095 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2096 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2097 Command 'print_theory' outputs the normalized system of recursive
  2098 equations, see section "definitions".
  2099 
  2100 * Configuration options are maintained within the theory or proof
  2101 context (with name and type bool/int/string), providing a very simple
  2102 interface to a poor-man's version of general context data.  Tools may
  2103 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2104 these values using Config.get etc.  Users may change options via an
  2105 associated attribute of the same name.  This form of context
  2106 declaration works particularly well with commands 'declare' or
  2107 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2108 very easy to avoid global references, which would not observe Isar
  2109 toplevel undo/redo and fail to work with multithreading.
  2110 
  2111 Various global ML references of Pure and HOL have been turned into
  2112 configuration options:
  2113 
  2114   Unify.search_bound		unify_search_bound
  2115   Unify.trace_bound		unify_trace_bound
  2116   Unify.trace_simp		unify_trace_simp
  2117   Unify.trace_types		unify_trace_types
  2118   Simplifier.simp_depth_limit	simp_depth_limit
  2119   Blast.depth_limit		blast_depth_limit
  2120   DatatypeProp.dtK		datatype_distinctness_limit
  2121   fast_arith_neq_limit  	fast_arith_neq_limit
  2122   fast_arith_split_limit	fast_arith_split_limit
  2123 
  2124 * Named collections of theorems may be easily installed as context
  2125 data using the functor NamedThmsFun (see also
  2126 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2127 attributes; there is also a toplevel print command.  This facility is
  2128 just a common case of general context data, which is the preferred way
  2129 for anything more complex than just a list of facts in canonical
  2130 order.
  2131 
  2132 * Isar: command 'declaration' augments a local theory by generic
  2133 declaration functions written in ML.  This enables arbitrary content
  2134 being added to the context, depending on a morphism that tells the
  2135 difference of the original declaration context wrt. the application
  2136 context encountered later on.
  2137 
  2138 * Isar: proper interfaces for simplification procedures.  Command
  2139 'simproc_setup' declares named simprocs (with match patterns, and body
  2140 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2141 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2142 
  2143 * Isar: an extra pair of brackets around attribute declarations
  2144 abbreviates a theorem reference involving an internal dummy fact,
  2145 which will be ignored later --- only the effect of the attribute on
  2146 the background context will persist.  This form of in-place
  2147 declarations is particularly useful with commands like 'declare' and
  2148 'using', for example ``have A using [[simproc a]] by simp''.
  2149 
  2150 * Isar: method "assumption" (and implicit closing of subproofs) now
  2151 takes simple non-atomic goal assumptions into account: after applying
  2152 an assumption as a rule the resulting subgoals are solved by atomic
  2153 assumption steps.  This is particularly useful to finish 'obtain'
  2154 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2155 without referring to the original premise "!!x. P x ==> thesis" in the
  2156 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2157 more permissive.
  2158 
  2159 * Isar: implicit use of prems from the Isar proof context is
  2160 considered a legacy feature.  Common applications like ``have A .''
  2161 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2162 referencing facts explicitly here improves readability and
  2163 maintainability of proof texts.
  2164 
  2165 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2166 the obtained context from the course of reasoning!  For example:
  2167 
  2168   assume "EX x y. A x & B y"   -- "any previous fact"
  2169   then guess x and y by clarify
  2170 
  2171 This technique is potentially adventurous, depending on the facts and
  2172 proof tools being involved here.
  2173 
  2174 * Isar: known facts from the proof context may be specified as literal
  2175 propositions, using ASCII back-quote syntax.  This works wherever
  2176 named facts used to be allowed so far, in proof commands, proof
  2177 methods, attributes etc.  Literal facts are retrieved from the context
  2178 according to unification of type and term parameters.  For example,
  2179 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2180 theorems in the current context, then these are valid literal facts:
  2181 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2182 
  2183 There is also a proof method "fact" which does the same composition
  2184 for explicit goal states, e.g. the following proof texts coincide with
  2185 certain special cases of literal facts:
  2186 
  2187   have "A" by fact                 ==  note `A`
  2188   have "A ==> B" by fact           ==  note `A ==> B`
  2189   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2190   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2191 
  2192 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2193 outer syntax.  Thus symbolic identifiers may be used without
  2194 additional white space in declarations like this: ``assume *: A''.
  2195 
  2196 * Isar: 'print_facts' prints all local facts of the current context,
  2197 both named and unnamed ones.
  2198 
  2199 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2200 
  2201   def x == "t" and y == "u"
  2202 
  2203 * Isar: added command 'unfolding', which is structurally similar to
  2204 'using', but affects both the goal state and facts by unfolding given
  2205 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2206 'unfolded' attribute may be replaced by first-class proof text.
  2207 
  2208 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2209 and command 'unfolding' now all support object-level equalities
  2210 (potentially conditional).  The underlying notion of rewrite rule is
  2211 analogous to the 'rule_format' attribute, but *not* that of the
  2212 Simplifier (which is usually more generous).
  2213 
  2214 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2215 premises of a theorem by n. Useful in conjunction with drule.
  2216 
  2217 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2218 method expression within a sandbox consisting of the first N
  2219 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2220 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2221 simplifies all new goals that emerge from applying rule foo to the
  2222 originally first one.
  2223 
  2224 * Isar: schematic goals are no longer restricted to higher-order
  2225 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2226 expected.
  2227 
  2228 * Isar: the conclusion of a long theorem statement is now either
  2229 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2230 (essentially a disjunction of cases with local parameters and
  2231 assumptions).  The latter allows to express general elimination rules
  2232 adequately; in this notation common elimination rules look like this:
  2233 
  2234   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2235     assumes "EX x. P x"
  2236     obtains x where "P x"
  2237 
  2238   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2239     assumes "A & B"
  2240     obtains A and B
  2241 
  2242   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2243     assumes "A | B"
  2244     obtains
  2245       A
  2246     | B
  2247 
  2248 The subsequent classical rules even refer to the formal "thesis"
  2249 explicitly:
  2250 
  2251   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2252     obtains "~ thesis"
  2253 
  2254   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2255     obtains "thesis ==> something"
  2256 
  2257 The actual proof of an 'obtains' statement is analogous to that of the
  2258 Isar proof element 'obtain', only that there may be several cases.
  2259 Optional case names may be specified in parentheses; these will be
  2260 available both in the present proof and as annotations in the
  2261 resulting rule, for later use with the 'cases' method (cf. attribute
  2262 case_names).
  2263 
  2264 * Isar: the assumptions of a long theorem statement are available as
  2265 "assms" fact in the proof context.  This is more appropriate than the
  2266 (historical) "prems", which refers to all assumptions of the current
  2267 context, including those from the target locale, proof body etc.
  2268 
  2269 * Isar: 'print_statement' prints theorems from the current theory or
  2270 proof context in long statement form, according to the syntax of a
  2271 top-level lemma.
  2272 
  2273 * Isar: 'obtain' takes an optional case name for the local context
  2274 introduction rule (default "that").
  2275 
  2276 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2277 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2278 to occur.
  2279 
  2280 * Pure: syntax "CONST name" produces a fully internalized constant
  2281 according to the current context.  This is particularly useful for
  2282 syntax translations that should refer to internal constant
  2283 representations independently of name spaces.
  2284 
  2285 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2286 instead of "FOO ". This allows multiple binder declarations to coexist
  2287 in the same context.  INCOMPATIBILITY.
  2288 
  2289 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2290 primitive that also works in a locale context (both for constants and
  2291 fixed variables). Type declaration and internal syntactic representation
  2292 of given constants retrieved from the context. Likewise, the
  2293 'no_notation' command allows to remove given syntax annotations from the
  2294 current context.
  2295 
  2296 * Isar/locales: new derived specification elements 'axiomatization',
  2297 'definition', 'abbreviation', which support type-inference, admit
  2298 object-level specifications (equality, equivalence).  See also the
  2299 isar-ref manual.  Examples:
  2300 
  2301   axiomatization
  2302     eq  (infix "===" 50) where
  2303     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2304 
  2305   definition "f x y = x + y + 1"
  2306   definition g where "g x = f x x"
  2307 
  2308   abbreviation
  2309     neq  (infix "=!=" 50) where
  2310     "x =!= y == ~ (x === y)"
  2311 
  2312 These specifications may be also used in a locale context.  Then the
  2313 constants being introduced depend on certain fixed parameters, and the
  2314 constant name is qualified by the locale base name.  An internal
  2315 abbreviation takes care for convenient input and output, making the
  2316 parameters implicit and using the original short name.  See also
  2317 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2318 entities from a monomorphic theory.
  2319 
  2320 Presently, abbreviations are only available 'in' a target locale, but
  2321 not inherited by general import expressions.  Also note that
  2322 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2323 'translations' in common applications.  The "no_abbrevs" print mode
  2324 prevents folding of abbreviations in term output.
  2325 
  2326 Concrete syntax is attached to specified constants in internal form,
  2327 independently of name spaces.  The parse tree representation is
  2328 slightly different -- use 'notation' instead of raw 'syntax', and
  2329 'translations' with explicit "CONST" markup to accommodate this.
  2330 
  2331 * Pure/Isar: unified syntax for new-style specification mechanisms
  2332 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2333 full type inference and dummy patterns ("_").  For example:
  2334 
  2335   definition "K x _ = x"
  2336 
  2337   inductive conj for A B
  2338   where "A ==> B ==> conj A B"
  2339 
  2340 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2341 the current context.  Print mode "no_abbrevs" prevents inversion of
  2342 abbreviations on output.
  2343 
  2344 * Isar/locales: improved parameter handling: use of locales "var" and
  2345 "struct" no longer necessary; - parameter renamings are no longer
  2346 required to be injective.  For example, this allows to define
  2347 endomorphisms as locale endom = homom mult mult h.
  2348 
  2349 * Isar/locales: changed the way locales with predicates are defined.
  2350 Instead of accumulating the specification, the imported expression is
  2351 now an interpretation.  INCOMPATIBILITY: different normal form of
  2352 locale expressions.  In particular, in interpretations of locales with
  2353 predicates, goals repesenting already interpreted fragments are not
  2354 removed automatically.  Use methods `intro_locales' and
  2355 `unfold_locales'; see below.
  2356 
  2357 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2358 provide backward reasoning on locales predicates.  The methods are
  2359 aware of interpretations and discharge corresponding goals.
  2360 `intro_locales' is less aggressive then `unfold_locales' and does not
  2361 unfold predicates to assumptions.
  2362 
  2363 * Isar/locales: the order in which locale fragments are accumulated
  2364 has changed.  This enables to override declarations from fragments due
  2365 to interpretations -- for example, unwanted simp rules.
  2366 
  2367 * Isar/locales: interpretation in theories and proof contexts has been
  2368 extended.  One may now specify (and prove) equations, which are
  2369 unfolded in interpreted theorems.  This is useful for replacing
  2370 defined concepts (constants depending on locale parameters) by
  2371 concepts already existing in the target context.  Example:
  2372 
  2373   interpretation partial_order ["op <= :: [int, int] => bool"]
  2374     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2375 
  2376 Typically, the constant `partial_order.less' is created by a
  2377 definition specification element in the context of locale
  2378 partial_order.
  2379 
  2380 * Method "induct": improved internal context management to support
  2381 local fixes and defines on-the-fly. Thus explicit meta-level
  2382 connectives !!  and ==> are rarely required anymore in inductive goals
  2383 (using object-logic connectives for this purpose has been long
  2384 obsolete anyway). Common proof patterns are explained in
  2385 src/HOL/Induct/Common_Patterns.thy, see also
  2386 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2387 examples.
  2388 
  2389 * Method "induct": improved handling of simultaneous goals. Instead of
  2390 introducing object-level conjunction, the statement is now split into
  2391 several conclusions, while the corresponding symbolic cases are nested
  2392 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2393 see src/HOL/Induct/Common_Patterns.thy, for example.
  2394 
  2395 * Method "induct": mutual induction rules are now specified as a list
  2396 of rule sharing the same induction cases. HOL packages usually provide
  2397 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2398 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2399 mutual induction rules differently, i.e. like this:
  2400 
  2401   (induct rule: foo_bar.inducts)
  2402   (induct set: foo bar)
  2403   (induct pred: foo bar)
  2404   (induct type: foo bar)
  2405 
  2406 The ML function ProjectRule.projections turns old-style rules into the
  2407 new format.
  2408 
  2409 * Method "coinduct": dual of induction, see
  2410 src/HOL/Library/Coinductive_List.thy for various examples.
  2411 
  2412 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2413 considered a legacy feature.
  2414 
  2415 * Attribute "symmetric" produces result with standardized schematic
  2416 variables (index 0).  Potential INCOMPATIBILITY.
  2417 
  2418 * Simplifier: by default the simplifier trace only shows top level
  2419 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2420 default. Thus there is less danger of being flooded by the trace. The
  2421 trace indicates where parts have been suppressed.
  2422   
  2423 * Provers/classical: removed obsolete classical version of elim_format
  2424 attribute; classical elim/dest rules are now treated uniformly when
  2425 manipulating the claset.
  2426 
  2427 * Provers/classical: stricter checks to ensure that supplied intro,
  2428 dest and elim rules are well-formed; dest and elim rules must have at
  2429 least one premise.
  2430 
  2431 * Provers/classical: attributes dest/elim/intro take an optional
  2432 weight argument for the rule (just as the Pure versions).  Weights are
  2433 ignored by automated tools, but determine the search order of single
  2434 rule steps.
  2435 
  2436 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2437 where the body does not mention the bound variable.  Note that dummy
  2438 patterns implicitly depend on their context of bounds, which makes
  2439 "{_. _}" match any set comprehension as expected.  Potential
  2440 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2441 constant "_idtdummy" in the binding position.
  2442 
  2443 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2444 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2445 for example "A -> B" => "Pi A (%_. B)".
  2446 
  2447 * Pure: 'class_deps' command visualizes the subclass relation, using
  2448 the graph browser tool.
  2449 
  2450 * Pure: 'print_theory' now suppresses certain internal declarations by
  2451 default; use '!' option for full details.
  2452 
  2453 
  2454 *** HOL ***
  2455 
  2456 * Method "metis" proves goals by applying the Metis general-purpose
  2457 resolution prover (see also http://gilith.com/software/metis/).
  2458 Examples are in the directory MetisExamples.  WARNING: the
  2459 Isabelle/HOL-Metis integration does not yet work properly with
  2460 multi-threading.
  2461   
  2462 * Command 'sledgehammer' invokes external automatic theorem provers as
  2463 background processes.  It generates calls to the "metis" method if
  2464 successful. These can be pasted into the proof.  Users do not have to
  2465 wait for the automatic provers to return.  WARNING: does not really
  2466 work with multi-threading.
  2467 
  2468 * New "auto_quickcheck" feature tests outermost goal statements for
  2469 potential counter-examples.  Controlled by ML references
  2470 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2471 5000 milliseconds).  Fails silently if statements is outside of
  2472 executable fragment, or any other codgenerator problem occurs.
  2473 
  2474 * New constant "undefined" with axiom "undefined x = undefined".
  2475 
  2476 * Added class "HOL.eq", allowing for code generation with polymorphic
  2477 equality.
  2478 
  2479 * Some renaming of class constants due to canonical name prefixing in
  2480 the new 'class' package:
  2481 
  2482     HOL.abs ~> HOL.abs_class.abs
  2483     HOL.divide ~> HOL.divide_class.divide
  2484     0 ~> HOL.zero_class.zero
  2485     1 ~> HOL.one_class.one
  2486     op + ~> HOL.plus_class.plus
  2487     op - ~> HOL.minus_class.minus
  2488     uminus ~> HOL.minus_class.uminus
  2489     op * ~> HOL.times_class.times
  2490     op < ~> HOL.ord_class.less
  2491     op <= > HOL.ord_class.less_eq
  2492     Nat.power ~> Power.power_class.power
  2493     Nat.size ~> Nat.size_class.size
  2494     Numeral.number_of ~> Numeral.number_class.number_of
  2495     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2496     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2497     Orderings.min ~> Orderings.ord_class.min
  2498     Orderings.max ~> Orderings.ord_class.max
  2499     Divides.op div ~> Divides.div_class.div
  2500     Divides.op mod ~> Divides.div_class.mod
  2501     Divides.op dvd ~> Divides.div_class.dvd
  2502 
  2503 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2504 
  2505 a) User-defined constants using any of the names "plus", "minus",
  2506 "times", "less" or "less_eq". The standard syntax translations for
  2507 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2508 names.
  2509 
  2510 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2511 INCOMPATIBILITY: use more specific names.
  2512 
  2513 c) Permutative equations (e.g. "a + b = b + a")
  2514 Since the change of names also changes the order of terms, permutative
  2515 rewrite rules may get applied in a different order. Experience shows
  2516 that this is rarely the case (only two adaptions in the whole Isabelle
  2517 distribution).  INCOMPATIBILITY: rewrite proofs
  2518 
  2519 d) ML code directly refering to constant names
  2520 This in general only affects hand-written proof tactics, simprocs and
  2521 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2522 Consider using @{const_name} antiquotation.
  2523 
  2524 * New class "default" with associated constant "default".
  2525 
  2526 * Function "sgn" is now overloaded and available on int, real, complex
  2527 (and other numeric types), using class "sgn".  Two possible defs of
  2528 sgn are given as equational assumptions in the classes sgn_if and
  2529 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2530 INCOMPATIBILITY.
  2531 
  2532 * Locale "partial_order" now unified with class "order" (cf. theory
  2533 Orderings), added parameter "less".  INCOMPATIBILITY.
  2534 
  2535 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2536 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2537 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2538 
  2539 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2540 changed order of proof goals in instance proofs.
  2541 
  2542 * The transitivity reasoner for partial and linear orders is set up
  2543 for classes "order" and "linorder".  Instances of the reasoner are available
  2544 in all contexts importing or interpreting the corresponding locales.
  2545 Method "order" invokes the reasoner separately; the reasoner
  2546 is also integrated with the Simplifier as a solver.  Diagnostic
  2547 command 'print_orders' shows the available instances of the reasoner
  2548 in the current context.
  2549 
  2550 * Localized monotonicity predicate in theory "Orderings"; integrated
  2551 lemmas max_of_mono and min_of_mono with this predicate.
  2552 INCOMPATIBILITY.
  2553 
  2554 * Formulation of theorem "dense" changed slightly due to integration
  2555 with new class dense_linear_order.
  2556 
  2557 * Uniform lattice theory development in HOL.
  2558 
  2559     constants "meet" and "join" now named "inf" and "sup"
  2560     constant "Meet" now named "Inf"
  2561 
  2562     classes "meet_semilorder" and "join_semilorder" now named
  2563       "lower_semilattice" and "upper_semilattice"
  2564     class "lorder" now named "lattice"
  2565     class "comp_lat" now named "complete_lattice"
  2566 
  2567     Instantiation of lattice classes allows explicit definitions
  2568     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2569 
  2570   INCOMPATIBILITY.  Theorem renames:
  2571 
  2572     meet_left_le            ~> inf_le1
  2573     meet_right_le           ~> inf_le2
  2574     join_left_le            ~> sup_ge1
  2575     join_right_le           ~> sup_ge2
  2576     meet_join_le            ~> inf_sup_ord
  2577     le_meetI                ~> le_infI
  2578     join_leI                ~> le_supI
  2579     le_meet                 ~> le_inf_iff
  2580     le_join                 ~> ge_sup_conv
  2581     meet_idempotent         ~> inf_idem
  2582     join_idempotent         ~> sup_idem
  2583     meet_comm               ~> inf_commute
  2584     join_comm               ~> sup_commute
  2585     meet_leI1               ~> le_infI1
  2586     meet_leI2               ~> le_infI2
  2587     le_joinI1               ~> le_supI1
  2588     le_joinI2               ~> le_supI2
  2589     meet_assoc              ~> inf_assoc
  2590     join_assoc              ~> sup_assoc
  2591     meet_left_comm          ~> inf_left_commute
  2592     meet_left_idempotent    ~> inf_left_idem
  2593     join_left_comm          ~> sup_left_commute
  2594     join_left_idempotent    ~> sup_left_idem
  2595     meet_aci                ~> inf_aci
  2596     join_aci                ~> sup_aci
  2597     le_def_meet             ~> le_iff_inf
  2598     le_def_join             ~> le_iff_sup
  2599     join_absorp2            ~> sup_absorb2
  2600     join_absorp1            ~> sup_absorb1
  2601     meet_absorp1            ~> inf_absorb1
  2602     meet_absorp2            ~> inf_absorb2
  2603     meet_join_absorp        ~> inf_sup_absorb
  2604     join_meet_absorp        ~> sup_inf_absorb
  2605     distrib_join_le         ~> distrib_sup_le
  2606     distrib_meet_le         ~> distrib_inf_le
  2607 
  2608     add_meet_distrib_left   ~> add_inf_distrib_left
  2609     add_join_distrib_left   ~> add_sup_distrib_left
  2610     is_join_neg_meet        ~> is_join_neg_inf
  2611     is_meet_neg_join        ~> is_meet_neg_sup
  2612     add_meet_distrib_right  ~> add_inf_distrib_right
  2613     add_join_distrib_right  ~> add_sup_distrib_right
  2614     add_meet_join_distribs  ~> add_sup_inf_distribs
  2615     join_eq_neg_meet        ~> sup_eq_neg_inf
  2616     meet_eq_neg_join        ~> inf_eq_neg_sup
  2617     add_eq_meet_join        ~> add_eq_inf_sup
  2618     meet_0_imp_0            ~> inf_0_imp_0
  2619     join_0_imp_0            ~> sup_0_imp_0
  2620     meet_0_eq_0             ~> inf_0_eq_0
  2621     join_0_eq_0             ~> sup_0_eq_0
  2622     neg_meet_eq_join        ~> neg_inf_eq_sup
  2623     neg_join_eq_meet        ~> neg_sup_eq_inf
  2624     join_eq_if              ~> sup_eq_if
  2625 
  2626     mono_meet               ~> mono_inf
  2627     mono_join               ~> mono_sup
  2628     meet_bool_eq            ~> inf_bool_eq
  2629     join_bool_eq            ~> sup_bool_eq
  2630     meet_fun_eq             ~> inf_fun_eq
  2631     join_fun_eq             ~> sup_fun_eq
  2632     meet_set_eq             ~> inf_set_eq
  2633     join_set_eq             ~> sup_set_eq
  2634     meet1_iff               ~> inf1_iff
  2635     meet2_iff               ~> inf2_iff
  2636     meet1I                  ~> inf1I
  2637     meet2I                  ~> inf2I
  2638     meet1D1                 ~> inf1D1
  2639     meet2D1                 ~> inf2D1
  2640     meet1D2                 ~> inf1D2
  2641     meet2D2                 ~> inf2D2
  2642     meet1E                  ~> inf1E
  2643     meet2E                  ~> inf2E
  2644     join1_iff               ~> sup1_iff
  2645     join2_iff               ~> sup2_iff
  2646     join1I1                 ~> sup1I1
  2647     join2I1                 ~> sup2I1
  2648     join1I1                 ~> sup1I1
  2649     join2I2                 ~> sup1I2
  2650     join1CI                 ~> sup1CI
  2651     join2CI                 ~> sup2CI
  2652     join1E                  ~> sup1E
  2653     join2E                  ~> sup2E
  2654 
  2655     is_meet_Meet            ~> is_meet_Inf
  2656     Meet_bool_def           ~> Inf_bool_def
  2657     Meet_fun_def            ~> Inf_fun_def
  2658     Meet_greatest           ~> Inf_greatest
  2659     Meet_lower              ~> Inf_lower
  2660     Meet_set_def            ~> Inf_set_def
  2661 
  2662     Sup_def                 ~> Sup_Inf
  2663     Sup_bool_eq             ~> Sup_bool_def
  2664     Sup_fun_eq              ~> Sup_fun_def
  2665     Sup_set_eq              ~> Sup_set_def
  2666 
  2667     listsp_meetI            ~> listsp_infI
  2668     listsp_meet_eq          ~> listsp_inf_eq
  2669 
  2670     meet_min                ~> inf_min
  2671     join_max                ~> sup_max
  2672 
  2673 * Added syntactic class "size"; overloaded constant "size" now has
  2674 type "'a::size ==> bool"
  2675 
  2676 * Internal reorganisation of `size' of datatypes: size theorems
  2677 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2678 simplification rules by default!); theorems "prod.size" now named
  2679 "*.size".
  2680 
  2681 * Class "div" now inherits from class "times" rather than "type".
  2682 INCOMPATIBILITY.
  2683 
  2684 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2685 Linorder etc.  have disappeared; operations defined in terms of
  2686 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2687 
  2688 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2689 
  2690 * HOL-Word: New extensive library and type for generic, fixed size
  2691 machine words, with arithemtic, bit-wise, shifting and rotating
  2692 operations, reflection into int, nat, and bool lists, automation for
  2693 linear arithmetic (by automatic reflection into nat or int), including
  2694 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2695 arithmetic type classes, supporting automatic simplification of
  2696 numerals on all operations.
  2697 
  2698 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2699 
  2700 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2701 
  2702 * Code generator library theories:
  2703   - Code_Integer represents HOL integers by big integer literals in target
  2704     languages.
  2705   - Code_Char represents HOL characters by character literals in target
  2706     languages.
  2707   - Code_Char_chr like Code_Char, but also offers treatment of character
  2708     codes; includes Code_Integer.
  2709   - Executable_Set allows to generate code for finite sets using lists.
  2710   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2711     denominator).
  2712   - Executable_Real implements a subset of real numbers, namly those
  2713     representable by rational numbers.
  2714   - Efficient_Nat implements natural numbers by integers, which in general will
  2715     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2716     includes Code_Integer.
  2717   - Code_Index provides an additional datatype index which is mapped to
  2718     target-language built-in integers.
  2719   - Code_Message provides an additional datatype message_string which is isomorphic to
  2720     strings; messages are mapped to target-language strings.
  2721 
  2722 * New package for inductive predicates
  2723 
  2724   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2725 
  2726     inductive
  2727       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2728       for z_1 :: U_1 and ... and z_n :: U_m
  2729     where
  2730       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2731     | ...
  2732 
  2733   with full support for type-inference, rather than
  2734 
  2735     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2736 
  2737     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2738     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2739 
  2740     inductive "s z_1 ... z_m"
  2741     intros
  2742       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2743       ...
  2744 
  2745   For backward compatibility, there is a wrapper allowing inductive
  2746   sets to be defined with the new package via
  2747 
  2748     inductive_set
  2749       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2750       for z_1 :: U_1 and ... and z_n :: U_m
  2751     where
  2752       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2753     | ...
  2754 
  2755   or
  2756 
  2757     inductive_set
  2758       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2759       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2760       for z_1 :: U_1 and ... and z_n :: U_m
  2761     where
  2762       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2763     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2764     | ...
  2765 
  2766   if the additional syntax "p ..." is required.
  2767 
  2768   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2769   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2770 
  2771   INCOMPATIBILITIES:
  2772 
  2773   - Since declaration and definition of inductive sets or predicates
  2774     is no longer separated, abbreviations involving the newly
  2775     introduced sets or predicates must be specified together with the
  2776     introduction rules after the 'where' keyword (see above), rather
  2777     than before the actual inductive definition.
  2778 
  2779   - The variables in induction and elimination rules are now
  2780     quantified in the order of their occurrence in the introduction
  2781     rules, rather than in alphabetical order. Since this may break
  2782     some proofs, these proofs either have to be repaired, e.g. by
  2783     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2784     statements of the form
  2785 
  2786       case (rule_i a_i_1 ... a_i_{k_i})
  2787 
  2788     or the old order of quantification has to be restored by explicitly adding
  2789     meta-level quantifiers in the introduction rules, i.e.
  2790 
  2791       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2792 
  2793   - The format of the elimination rules is now
  2794 
  2795       p z_1 ... z_m x_1 ... x_n ==>
  2796         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2797         ==> ... ==> P
  2798 
  2799     for predicates and
  2800 
  2801       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2802         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2803         ==> ... ==> P
  2804 
  2805     for sets rather than
  2806 
  2807       x : s z_1 ... z_m ==>
  2808         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2809         ==> ... ==> P
  2810 
  2811     This may require terms in goals to be expanded to n-tuples
  2812     (e.g. using case_tac or simplification with the split_paired_all
  2813     rule) before the above elimination rule is applicable.
  2814 
  2815   - The elimination or case analysis rules for (mutually) inductive
  2816     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2817     list of rules "p_1_..._p_k.elims" is no longer available.
  2818 
  2819 * New package "function"/"fun" for general recursive functions,
  2820 supporting mutual and nested recursion, definitions in local contexts,
  2821 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2822 for small examples, and the separate tutorial on the function
  2823 package. The old recdef "package" is still available as before, but
  2824 users are encouraged to use the new package.
  2825 
  2826 * Method "lexicographic_order" automatically synthesizes termination
  2827 relations as lexicographic combinations of size measures. 
  2828 
  2829 * Case-expressions allow arbitrary constructor-patterns (including
  2830 "_") and take their order into account, like in functional
  2831 programming.  Internally, this is translated into nested
  2832 case-expressions; missing cases are added and mapped to the predefined
  2833 constant "undefined". In complicated cases printing may no longer show
  2834 the original input but the internal form. Lambda-abstractions allow
  2835 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2836 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2837 variable.
  2838 
  2839 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2840 is an abbreviation for "of_nat :: nat => int". The simplification
  2841 rules for "of_nat" have been changed to work like "int" did
  2842 previously.  Potential INCOMPATIBILITY:
  2843   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2844   - of_nat_diff and of_nat_mult are no longer default simp rules
  2845 
  2846 * Method "algebra" solves polynomial equations over (semi)rings using
  2847 Groebner bases. The (semi)ring structure is defined by locales and the
  2848 tool setup depends on that generic context. Installing the method for
  2849 a specific type involves instantiating the locale and possibly adding
  2850 declarations for computation on the coefficients.  The method is
  2851 already instantiated for natural numbers and for the axiomatic class
  2852 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2853 CALCULEMUS 2007 for the general principles underlying this
  2854 architecture of context-aware proof-tools.
  2855 
  2856 * Method "ferrack" implements quantifier elimination over
  2857 special-purpose dense linear orders using locales (analogous to
  2858 "algebra"). The method is already installed for class
  2859 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2860 rat, etc.
  2861 
  2862 * Former constant "List.op @" now named "List.append".  Use ML
  2863 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2864 circumvent possible incompatibilities when working on ML level.
  2865 
  2866 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2867 
  2868 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2869 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2870 
  2871 * New syntax for Haskell-like list comprehension (input only), eg.
  2872 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2873 
  2874 * The special syntax for function "filter" has changed from [x :
  2875 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2876 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2877 
  2878 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2879 defined on nat only, as an abbreviation for [a..<Suc b]
  2880 INCOMPATIBILITY.
  2881 
  2882 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2883 
  2884 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2885 
  2886 * New lemma collection field_simps (an extension of ring_simps) for
  2887 manipulating (in)equations involving division. Multiplies with all
  2888 denominators that can be proved to be non-zero (in equations) or
  2889 positive/negative (in inequations).
  2890 
  2891 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2892 have been improved and renamed to ring_simps, group_simps and
  2893 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2894 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2895 
  2896 * Theory Library/Commutative_Ring: switched from recdef to function
  2897 package; constants add, mul, pow now curried.  Infix syntax for
  2898 algebraic operations.
  2899 
  2900 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2901 INCOMPATIBILITY.
  2902 
  2903 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2904 INCOMPATIBILITY.
  2905 
  2906 * HOL/records: generalised field-update to take a function on the
  2907 field rather than the new value: r(|A := x|) is translated to A_update
  2908 (K x) r The K-combinator that is internally used is called K_record.
  2909 INCOMPATIBILITY: Usage of the plain update functions has to be
  2910 adapted.
  2911  
  2912 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2913 * x = 0, which are required for a semiring.  Richer structures do not
  2914 inherit from semiring_0 anymore, because this property is a theorem
  2915 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2916 there is more to prove, but this is mostly trivial.
  2917 
  2918 * Class "recpower" is generalized to arbitrary monoids, not just
  2919 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2920 commutativity or semiring properties additionally.
  2921 
  2922 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2923 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2924 better use 'abbreviation'.
  2925 
  2926 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2927 
  2928 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2929 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2930 significant changes for setting up numeral syntax for types:
  2931   - New constants Numeral.pred and Numeral.succ instead
  2932       of former Numeral.bin_pred and Numeral.bin_succ.
  2933   - Use integer operations instead of bin_add, bin_mult and so on.
  2934   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2935   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2936 
  2937 See src/HOL/Integ/IntArith.thy for an example setup.
  2938 
  2939 * Command 'normal_form' computes the normal form of a term that may
  2940 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2941 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2942 heavy-duty computations because the functions are compiled to ML
  2943 first.  Correspondingly, a method "normalization" is provided.  See
  2944 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2945 
  2946 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2947 25 like -->); output depends on the "iff" print_mode, the default is
  2948 "A = B" (with priority 50).
  2949 
  2950 * Relations less (<) and less_eq (<=) are also available on type bool.
  2951 Modified syntax to disallow nesting without explicit parentheses,
  2952 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2953 INCOMPATIBILITY.
  2954 
  2955 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2956 
  2957 * Relation composition operator "op O" now has precedence 75 and binds
  2958 stronger than union and intersection. INCOMPATIBILITY.
  2959 
  2960 * The old set interval syntax "{m..n(}" (and relatives) has been
  2961 removed.  Use "{m..<n}" (and relatives) instead.
  2962 
  2963 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2964 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2965 ``declare [[simproc del: neq]]''.
  2966 
  2967 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2968 True/False.
  2969 
  2970 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2971 
  2972 * Theorem setsum_mult renamed to setsum_right_distrib.
  2973 
  2974 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2975 ``rule'' method.
  2976 
  2977 * Reimplemented methods "sat" and "satx", with several improvements:
  2978 goals no longer need to be stated as "<prems> ==> False", equivalences
  2979 (i.e. "=" on type bool) are handled, variable names of the form
  2980 "lit_<n>" are no longer reserved, significant speedup.
  2981 
  2982 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2983 zChaff is still supported as well.
  2984 
  2985 * 'inductive' and 'datatype': provide projections of mutual rules,
  2986 bundled as foo_bar.inducts;
  2987 
  2988 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2989 Library.
  2990 
  2991 * Library: moved theory Accessible_Part to main HOL.
  2992 
  2993 * Library: added theory Coinductive_List of potentially infinite lists
  2994 as greatest fixed-point.
  2995 
  2996 * Library: added theory AssocList which implements (finite) maps as
  2997 association lists.
  2998 
  2999 * Method "evaluation" solves goals (i.e. a boolean expression)
  3000 efficiently by compiling it to ML.  The goal is "proved" (via an
  3001 oracle) if it evaluates to True.
  3002 
  3003 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3004 also when invoked by the simplifier.  This results in the Simplifier
  3005 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3006 Configuration option fast_arith_split_limit=0 recovers the old
  3007 behavior.
  3008 
  3009 * Support for hex (0x20) and binary (0b1001) numerals.
  3010 
  3011 * New method: reify eqs (t), where eqs are equations for an
  3012 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3013 parameter, computes a term s::'b and a list xs::'a list and proves the
  3014 theorem I xs s = t. This is also known as reification or quoting. The
  3015 resulting theorem is applied to the subgoal to substitute t with I xs
  3016 s.  If t is omitted, the subgoal itself is reified.
  3017 
  3018 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3019 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3020 where f is supposed to be a computable function (in the sense of code
  3021 generattion). The method uses reify to compute s and xs as above then
  3022 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3023 r and finally gets the theorem t = r, which is again applied to the
  3024 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3025 
  3026 * Reflection: Automatic reification now handels binding, an example is
  3027 available in src/HOL/ex/ReflectionEx.thy
  3028 
  3029 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3030 command 'statespace' that is similar to 'record', but introduces an
  3031 abstract specification based on the locale infrastructure instead of
  3032 HOL types.  This leads to extra flexibility in composing state spaces,
  3033 in particular multiple inheritance and renaming of components.
  3034 
  3035 
  3036 *** HOL-Complex ***
  3037 
  3038 * Hyperreal: Functions root and sqrt are now defined on negative real
  3039 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3040 Nonnegativity side conditions have been removed from many lemmas, so
  3041 that more subgoals may now be solved by simplification; potential
  3042 INCOMPATIBILITY.
  3043 
  3044 * Real: new type classes formalize real normed vector spaces and
  3045 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3046 and norm :: 'a => real.
  3047 
  3048 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3049 reals into other types. The overloaded constant Reals :: 'a set is now
  3050 defined as range of_real; potential INCOMPATIBILITY.
  3051 
  3052 * Real: proper support for ML code generation, including 'quickcheck'.
  3053 Reals are implemented as arbitrary precision rationals.
  3054 
  3055 * Hyperreal: Several constants that previously worked only for the
  3056 reals have been generalized, so they now work over arbitrary vector
  3057 spaces. Type annotations may need to be added in some cases; potential
  3058 INCOMPATIBILITY.
  3059 
  3060   Infinitesimal  :: ('a::real_normed_vector) star set
  3061   HFinite        :: ('a::real_normed_vector) star set
  3062   HInfinite      :: ('a::real_normed_vector) star set
  3063   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3064   monad          :: ('a::real_normed_vector) star => 'a star set
  3065   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3066   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3067   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3068   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3069   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3070   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3071   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3072   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3073   sgn            :: 'a::real_normed_vector => 'a
  3074   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3075 
  3076 * Complex: Some complex-specific constants are now abbreviations for
  3077 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3078 hnorm.  Other constants have been entirely removed in favor of the
  3079 polymorphic versions (INCOMPATIBILITY):
  3080 
  3081   approx        <-- capprox
  3082   HFinite       <-- CFinite
  3083   HInfinite     <-- CInfinite
  3084   Infinitesimal <-- CInfinitesimal
  3085   monad         <-- cmonad
  3086   galaxy        <-- cgalaxy
  3087   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3088   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3089   (ns)deriv     <-- (ns)cderiv
  3090 
  3091 
  3092 *** HOL-Algebra ***
  3093 
  3094 * Formalisation of ideals and the quotient construction over rings.
  3095 
  3096 * Order and lattice theory no longer based on records.
  3097 INCOMPATIBILITY.
  3098 
  3099 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3100 greatest_closed.  INCOMPATIBILITY.
  3101 
  3102 * Method algebra is now set up via an attribute.  For examples see
  3103 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3104 of algebraic structures.
  3105 
  3106 * Renamed theory CRing to Ring.
  3107 
  3108 
  3109 *** HOL-Nominal ***
  3110 
  3111 * Substantial, yet incomplete support for nominal datatypes (binding
  3112 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3113 src/HOL/Nominal/Examples.  Prospective users should consult
  3114 http://isabelle.in.tum.de/nominal/
  3115 
  3116 
  3117 *** ML ***
  3118 
  3119 * ML basics: just one true type int, which coincides with IntInf.int
  3120 (even on SML/NJ).
  3121 
  3122 * ML within Isar: antiquotations allow to embed statically-checked
  3123 formal entities in the source, referring to the context available at
  3124 compile-time.  For example:
  3125 
  3126 ML {* @{sort "{zero,one}"} *}
  3127 ML {* @{typ "'a => 'b"} *}
  3128 ML {* @{term "%x. x"} *}
  3129 ML {* @{prop "x == y"} *}
  3130 ML {* @{ctyp "'a => 'b"} *}
  3131 ML {* @{cterm "%x. x"} *}
  3132 ML {* @{cprop "x == y"} *}
  3133 ML {* @{thm asm_rl} *}
  3134 ML {* @{thms asm_rl} *}
  3135 ML {* @{type_name c} *}
  3136 ML {* @{type_syntax c} *}
  3137 ML {* @{const_name c} *}
  3138 ML {* @{const_syntax c} *}
  3139 ML {* @{context} *}
  3140 ML {* @{theory} *}
  3141 ML {* @{theory Pure} *}
  3142 ML {* @{theory_ref} *}
  3143 ML {* @{theory_ref Pure} *}
  3144 ML {* @{simpset} *}
  3145 ML {* @{claset} *}
  3146 ML {* @{clasimpset} *}
  3147 
  3148 The same works for sources being ``used'' within an Isar context.
  3149 
  3150 * ML in Isar: improved error reporting; extra verbosity with
  3151 ML_Context.trace enabled.
  3152 
  3153 * Pure/General/table.ML: the join operations now works via exceptions
  3154 DUP/SAME instead of type option. This is simpler in simple cases, and
  3155 admits slightly more efficient complex applications.
  3156 
  3157 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3158 use Context.generic instead of just theory.
  3159 
  3160 * Pure: datatype Context.generic joins theory/Proof.context and
  3161 provides some facilities for code that works in either kind of
  3162 context, notably GenericDataFun for uniform theory and proof data.
  3163 
  3164 * Pure: simplified internal attribute type, which is now always
  3165 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3166 local (Proof.context) attributes have been discontinued, while
  3167 minimizing code duplication. Thm.rule_attribute and
  3168 Thm.declaration_attribute build canonical attributes; see also structure
  3169 Context for further operations on Context.generic, notably
  3170 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3171 declarations and definitions.
  3172 
  3173 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3174 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3175 init only required for impure data. INCOMPATIBILITY: empty really need
  3176 to be empty (no dependencies on theory content!)
  3177 
  3178 * Pure/kernel: consts certification ignores sort constraints given in
  3179 signature declarations. (This information is not relevant to the
  3180 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3181 potential INCOMPATIBILITY.
  3182 
  3183 * Pure: axiomatic type classes are now purely definitional, with
  3184 explicit proofs of class axioms and super class relations performed
  3185 internally. See Pure/axclass.ML for the main internal interfaces --
  3186 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3187 AxClass.axiomatize_class/classrel/arity supersede
  3188 Sign.add_classes/classrel/arities.
  3189 
  3190 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3191 global/local versions on theory vs. Proof.context have been
  3192 discontinued; Attrib.syntax and Method.syntax have been adapted
  3193 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3194 attributes, methods, etc.
  3195 
  3196 * Pure: several functions of signature "... -> theory -> theory * ..."
  3197 have been reoriented to "... -> theory -> ... * theory" in order to
  3198 allow natural usage in combination with the ||>, ||>>, |-> and
  3199 fold_map combinators.
  3200 
  3201 * Pure: official theorem names (closed derivations) and additional
  3202 comments (tags) are now strictly separate.  Name hints -- which are
  3203 maintained as tags -- may be attached any time without affecting the
  3204 derivation.
  3205 
  3206 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3207 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3208 achieve the old behaviour.
  3209 
  3210 * Pure: the "Goal" constant is now called "prop", supporting a
  3211 slightly more general idea of ``protecting'' meta-level rule
  3212 statements.
  3213 
  3214 * Pure: Logic.(un)varify only works in a global context, which is now
  3215 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3216 Logic.legacy_(un)varify as temporary workaround.
  3217 
  3218 * Pure: structure Name provides scalable operations for generating
  3219 internal variable names, notably Name.variants etc.  This replaces
  3220 some popular functions from term.ML:
  3221 
  3222   Term.variant		->  Name.variant
  3223   Term.variantlist	->  Name.variant_list
  3224   Term.invent_names	->  Name.invent_list
  3225 
  3226 Note that low-level renaming rarely occurs in new code -- operations
  3227 from structure Variable are used instead (see below).
  3228 
  3229 * Pure: structure Variable provides fundamental operations for proper
  3230 treatment of fixed/schematic variables in a context.  For example,
  3231 Variable.import introduces fixes for schematics of given facts and
  3232 Variable.export reverses the effect (up to renaming) -- this replaces
  3233 various freeze_thaw operations.
  3234 
  3235 * Pure: structure Goal provides simple interfaces for
  3236 init/conclude/finish and tactical prove operations (replacing former
  3237 Tactic.prove).  Goal.prove is the canonical way to prove results
  3238 within a given context; Goal.prove_global is a degraded version for
  3239 theory level goals, including a global Drule.standard.  Note that
  3240 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3241 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3242 in a locale context).
  3243 
  3244 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3245 and type checking (Syntax.check_term etc.), with common combinations
  3246 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3247 which are considered legacy and await removal.
  3248 
  3249 * Pure/Syntax: generic interfaces for type unchecking
  3250 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3251 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3252 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3253 available for convenience, but refer to the very same operations using
  3254 a mere theory instead of a full context.
  3255 
  3256 * Isar: simplified treatment of user-level errors, using exception
  3257 ERROR of string uniformly.  Function error now merely raises ERROR,
  3258 without any side effect on output channels.  The Isar toplevel takes
  3259 care of proper display of ERROR exceptions.  ML code may use plain
  3260 handle/can/try; cat_error may be used to concatenate errors like this:
  3261 
  3262   ... handle ERROR msg => cat_error msg "..."
  3263 
  3264 Toplevel ML code (run directly or through the Isar toplevel) may be
  3265 embedded into the Isar toplevel with exception display/debug like
  3266 this:
  3267 
  3268   Isar.toplevel (fn () => ...)
  3269 
  3270 INCOMPATIBILITY, removed special transform_error facilities, removed
  3271 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3272 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3273 -- use plain ERROR instead.
  3274 
  3275 * Isar: theory setup now has type (theory -> theory), instead of a
  3276 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3277 
  3278 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3279 ProofContext.debug/verbose flags.
  3280 
  3281 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3282 theory before entering a proof state.  Transactions now always see a
  3283 quasi-functional intermediate checkpoint, both in interactive and
  3284 batch mode.
  3285 
  3286 * Isar: simplified interfaces for outer syntax.  Renamed
  3287 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3288 OuterSyntax.add_parsers -- this functionality is now included in
  3289 OuterSyntax.command etc.  INCOMPATIBILITY.
  3290 
  3291 * Simplifier: the simpset of a running simplification process now
  3292 contains a proof context (cf. Simplifier.the_context), which is the
  3293 very context that the initial simpset has been retrieved from (by
  3294 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3295 (solver, looper etc.) may depend on arbitrary proof data.
  3296 
  3297 * Simplifier.inherit_context inherits the proof context (plus the
  3298 local bounds) of the current simplification process; any simproc
  3299 etc. that calls the Simplifier recursively should do this!  Removed
  3300 former Simplifier.inherit_bounds, which is already included here --
  3301 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3302 specify an explicit context using Simplifier.context/theory_context.
  3303 
  3304 * Simplifier/Classical Reasoner: more abstract interfaces
  3305 change_simpset/claset for modifying the simpset/claset reference of a
  3306 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3307 INCOMPATIBILITY.
  3308 
  3309 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3310 "Trueprop" etc.
  3311 
  3312 
  3313 *** System ***
  3314 
  3315 * settings: the default heap location within ISABELLE_HOME_USER now
  3316 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3317 Isabelle installations.
  3318 
  3319 * isabelle-process: option -S (secure mode) disables some critical
  3320 operations, notably runtime compilation and evaluation of ML source
  3321 code.
  3322 
  3323 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3324 
  3325 * Support for parallel execution, using native multicore support of
  3326 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3327 independent theories, according to the given theory header
  3328 specifications. The maximum number of worker threads is specified via
  3329 usedir option -M or the "max-threads" setting in Proof General. A
  3330 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3331 to 6 on a 8-core machine.  User-code needs to observe certain
  3332 guidelines for thread-safe programming, see appendix A in the Isar
  3333 Implementation manual.
  3334 
  3335 
  3336 
  3337 New in Isabelle2005 (October 2005)
  3338 ----------------------------------
  3339 
  3340 *** General ***
  3341 
  3342 * Theory headers: the new header syntax for Isar theories is
  3343 
  3344   theory <name>
  3345   imports <theory1> ... <theoryN>
  3346   uses <file1> ... <fileM>
  3347   begin
  3348 
  3349 where the 'uses' part is optional.  The previous syntax
  3350 
  3351   theory <name> = <theory1> + ... + <theoryN>:
  3352 
  3353 will disappear in the next release.  Use isatool fixheaders to convert
  3354 existing theory files.  Note that there is no change in ancient
  3355 non-Isar theories now, but these will disappear soon.
  3356 
  3357 * Theory loader: parent theories can now also be referred to via
  3358 relative and absolute paths.
  3359 
  3360 * Command 'find_theorems' searches for a list of criteria instead of a
  3361 list of constants. Known criteria are: intro, elim, dest, name:string,
  3362 simp:term, and any term. Criteria can be preceded by '-' to select
  3363 theorems that do not match. Intro, elim, dest select theorems that
  3364 match the current goal, name:s selects theorems whose fully qualified
  3365 name contain s, and simp:term selects all simplification rules whose
  3366 lhs match term.  Any other term is interpreted as pattern and selects
  3367 all theorems matching the pattern. Available in ProofGeneral under
  3368 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3369 
  3370   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3371 
  3372 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3373 matching the current goal as introduction rule and not having "HOL."
  3374 in their name (i.e. not being defined in theory HOL).
  3375 
  3376 * Command 'thms_containing' has been discontinued in favour of
  3377 'find_theorems'; INCOMPATIBILITY.
  3378 
  3379 * Communication with Proof General is now 8bit clean, which means that
  3380 Unicode text in UTF-8 encoding may be used within theory texts (both
  3381 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3382 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3383 
  3384   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3385   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3386 
  3387 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3388 Classical Reasoner.  Typical big applications run around 2 times
  3389 faster.
  3390 
  3391 
  3392 *** Document preparation ***
  3393 
  3394 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3395 of raw sources.  Only those symbols that do not require additional
  3396 LaTeX packages (depending on comments in isabellesym.sty) are
  3397 displayed properly, everything else is left verbatim.  isatool display
  3398 and isatool print are used as front ends (these are subject to the
  3399 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3400 
  3401 * Command tags control specific markup of certain regions of text,
  3402 notably folding and hiding.  Predefined tags include "theory" (for
  3403 theory begin and end), "proof" for proof commands, and "ML" for
  3404 commands involving ML code; the additional tags "visible" and
  3405 "invisible" are unused by default.  Users may give explicit tag
  3406 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3407 interpretation of tags is determined by the LaTeX job during document
  3408 preparation: see option -V of isatool usedir, or options -n and -t of
  3409 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3410 \isadroptag.
  3411 
  3412 Several document versions may be produced at the same time via isatool
  3413 usedir (the generated index.html will link all of them).  Typical
  3414 specifications include ''-V document=theory,proof,ML'' to present
  3415 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3416 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3417 these parts without any formal replacement text.  The Isabelle site
  3418 default settings produce ''document'' and ''outline'' versions as
  3419 specified above.
  3420 
  3421 * Several new antiquotations:
  3422 
  3423   @{term_type term} prints a term with its type annotated;
  3424 
  3425   @{typeof term} prints the type of a term;
  3426 
  3427   @{const const} is the same as @{term const}, but checks that the
  3428   argument is a known logical constant;
  3429 
  3430   @{term_style style term} and @{thm_style style thm} print a term or
  3431   theorem applying a "style" to it
  3432 
  3433   @{ML text}
  3434 
  3435 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3436 definitions, equations, inequations etc., 'concl' printing only the
  3437 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3438 to print the specified premise.  TermStyle.add_style provides an ML
  3439 interface for introducing further styles.  See also the "LaTeX Sugar"
  3440 document practical applications.  The ML antiquotation prints
  3441 type-checked ML expressions verbatim.
  3442 
  3443 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3444 and 'text' support optional locale specification '(in loc)', which
  3445 specifies the default context for interpreting antiquotations.  For
  3446 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3447 
  3448 * Option 'locale=NAME' of antiquotations specifies an alternative
  3449 context interpreting the subsequent argument.  For example: @{thm
  3450 [locale=lattice] inf_assoc}.
  3451 
  3452 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3453 a proof context.
  3454 
  3455 * Proper output of antiquotations for theory commands involving a
  3456 proof context (such as 'locale' or 'theorem (in loc) ...').
  3457 
  3458 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3459 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3460 
  3461 * isatool usedir: new option -C (default true) controls whether option
  3462 -D should include a copy of the original document directory; -C false
  3463 prevents unwanted effects such as copying of administrative CVS data.
  3464 
  3465 
  3466 *** Pure ***
  3467 
  3468 * Considerably improved version of 'constdefs' command.  Now performs
  3469 automatic type-inference of declared constants; additional support for
  3470 local structure declarations (cf. locales and HOL records), see also
  3471 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3472 sequential dependencies of definitions within a single 'constdefs'
  3473 section; moreover, the declared name needs to be an identifier.  If
  3474 all fails, consider to fall back on 'consts' and 'defs' separately.
  3475 
  3476 * Improved indexed syntax and implicit structures.  First of all,
  3477 indexed syntax provides a notational device for subscripted
  3478 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3479 expressions.  Secondly, in a local context with structure
  3480 declarations, number indexes \<^sub>n or the empty index (default
  3481 number 1) refer to a certain fixed variable implicitly; option
  3482 show_structs controls printing of implicit structures.  Typical
  3483 applications of these concepts involve record types and locales.
  3484 
  3485 * New command 'no_syntax' removes grammar declarations (and
  3486 translations) resulting from the given syntax specification, which is
  3487 interpreted in the same manner as for the 'syntax' command.
  3488 
  3489 * 'Advanced' translation functions (parse_translation etc.) may depend
  3490 on the signature of the theory context being presently used for
  3491 parsing/printing, see also isar-ref manual.
  3492 
  3493 * Improved 'oracle' command provides a type-safe interface to turn an
  3494 ML expression of type theory -> T -> term into a primitive rule of
  3495 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3496 is already included here); see also FOL/ex/IffExample.thy;
  3497 INCOMPATIBILITY.
  3498 
  3499 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3500 before); "cI" is no longer bound, use "c.intro" instead.
  3501 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3502 axclasses vs. locales.
  3503 
  3504 * Improved internal renaming of symbolic identifiers -- attach primes
  3505 instead of base 26 numbers.
  3506 
  3507 * New flag show_question_marks controls printing of leading question
  3508 marks in schematic variable names.
  3509 
  3510 * In schematic variable names, *any* symbol following \<^isub> or
  3511 \<^isup> is now treated as part of the base name.  For example, the
  3512 following works without printing of awkward ".0" indexes:
  3513 
  3514   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3515     by simp
  3516 
  3517 * Inner syntax includes (*(*nested*) comments*).
  3518 
  3519 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3520 annotations as "(00...)".
  3521 
  3522 * Clear separation of logical types and nonterminals, where the latter
  3523 may only occur in 'syntax' specifications or type abbreviations.
  3524 Before that distinction was only partially implemented via type class
  3525 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3526 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3527 exotic syntax specifications may require further adaption
  3528 (e.g. Cube/Cube.thy).
  3529 
  3530 * Removed obsolete type class "logic", use the top sort {} instead.
  3531 Note that non-logical types should be declared as 'nonterminals'
  3532 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3533 specifications.
  3534 
  3535 * Attributes 'induct' and 'cases': type or set names may now be
  3536 locally fixed variables as well.
  3537 
  3538 * Simplifier: can now control the depth to which conditional rewriting
  3539 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3540 Limit.
  3541 
  3542 * Simplifier: simplification procedures may now take the current
  3543 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3544 interface), which is very useful for calling the Simplifier
  3545 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3546 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3547 low-level mk_simproc no longer applies Logic.varify internally, to
  3548 allow for use in a context of fixed variables.
  3549 
  3550 * thin_tac now works even if the assumption being deleted contains !!
  3551 or ==>.  More generally, erule now works even if the major premise of
  3552 the elimination rule contains !! or ==>.
  3553 
  3554 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3555 
  3556 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3557 from Pure, which contains all common declarations already.  Both
  3558 theories are defined via plain Isabelle/Isar .thy files.
  3559 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3560 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3561 use isatool fixcpure to adapt your theory and ML sources.
  3562 
  3563 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3564 selections of theorems in named facts via index ranges.
  3565 
  3566 * 'print_theorems': in theory mode, really print the difference
  3567 wrt. the last state (works for interactive theory development only),
  3568 in proof mode print all local facts (cf. 'print_facts');
  3569 
  3570 * 'hide': option '(open)' hides only base names.
  3571 
  3572 * More efficient treatment of intermediate checkpoints in interactive
  3573 theory development.
  3574 
  3575 * Code generator is now invoked via code_module (incremental code
  3576 generation) and code_library (modular code generation, ML structures
  3577 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3578 must be quoted when used as identifiers.
  3579 
  3580 * New 'value' command for reading, evaluating and printing terms using
  3581 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3582 quoted when used as identifier.
  3583 
  3584 
  3585 *** Locales ***
  3586 
  3587 * New commands for the interpretation of locale expressions in
  3588 theories (1), locales (2) and proof contexts (3).  These generate
  3589 proof obligations from the expression specification.  After the
  3590 obligations have been discharged, theorems of the expression are added
  3591 to the theory, target locale or proof context.  The synopsis of the
  3592 commands is a follows:
  3593 
  3594   (1) interpretation expr inst
  3595   (2) interpretation target < expr
  3596   (3) interpret expr inst
  3597 
  3598 Interpretation in theories and proof contexts require a parameter
  3599 instantiation of terms from the current context.  This is applied to
  3600 specifications and theorems of the interpreted expression.
  3601 Interpretation in locales only permits parameter renaming through the
  3602 locale expression.  Interpretation is smart in that interpretations
  3603 that are active already do not occur in proof obligations, neither are
  3604 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3605 inspect active interpretations of a particular locale.  For details,
  3606 see the Isar Reference manual.  Examples can be found in
  3607 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3608 
  3609 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3610 'interpret' instead.
  3611 
  3612 * New context element 'constrains' for adding type constraints to
  3613 parameters.
  3614 
  3615 * Context expressions: renaming of parameters with syntax
  3616 redeclaration.
  3617 
  3618 * Locale declaration: 'includes' disallowed.
  3619 
  3620 * Proper static binding of attribute syntax -- i.e. types / terms /
  3621 facts mentioned as arguments are always those of the locale definition
  3622 context, independently of the context of later invocations.  Moreover,
  3623 locale operations (renaming and type / term instantiation) are applied
  3624 to attribute arguments as expected.
  3625 
  3626 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3627 actual attributes; rare situations may require Attrib.attribute to
  3628 embed those attributes into Attrib.src that lack concrete syntax.
  3629 Attribute implementations need to cooperate properly with the static
  3630 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3631 Attrib.XXX_thm etc. already do the right thing without further
  3632 intervention.  Only unusual applications -- such as "where" or "of"
  3633 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3634 on the context and the facts involved -- may have to assign parsed
  3635 values to argument tokens explicitly.
  3636 
  3637 * Changed parameter management in theorem generation for long goal
  3638 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3639 theorem statement in rare situations.
  3640 
  3641 * Locale inspection command 'print_locale' omits notes elements.  Use
  3642 'print_locale!' to have them included in the output.
  3643 
  3644 
  3645 *** Provers ***
  3646 
  3647 * Provers/hypsubst.ML: improved version of the subst method, for
  3648 single-step rewriting: it now works in bound variable contexts. New is
  3649 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3650 rewrite a different subterm than the original subst method, which is
  3651 still available as 'simplesubst'.
  3652 
  3653 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3654 and quasi orders.
  3655 
  3656 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3657 reflexive-transitive closure of relations.
  3658 
  3659 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3660 limit (previously hard-coded with a value of 20) user-definable.
  3661 
  3662 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3663 is peformed already.  Object-logics merely need to finish their
  3664 initial simpset configuration as before.  INCOMPATIBILITY.
  3665 
  3666 
  3667 *** HOL ***
  3668 
  3669 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3670 
  3671   syntax (epsilon)
  3672     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3673 
  3674 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3675 and x-symbol; use option '-m epsilon' to get it actually printed.
  3676 Moreover, the mathematically important symbolic identifier \<epsilon>
  3677 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3678 
  3679 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3680 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3681 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3682 support corresponding Isar calculations.
  3683 
  3684 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3685 instead of ":".
  3686 
  3687 * theory SetInterval: changed the syntax for open intervals:
  3688 
  3689   Old       New
  3690   {..n(}    {..<n}
  3691   {)n..}    {n<..}
  3692   {m..n(}   {m..<n}
  3693   {)m..n}   {m<..n}
  3694   {)m..n(}  {m<..<n}
  3695 
  3696 The old syntax is still supported but will disappear in the next
  3697 release.  For conversion use the following Emacs search and replace
  3698 patterns (these are not perfect but work quite well):
  3699 
  3700   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3701   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3702 
  3703 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3704 equalities in commutative rings; method 'algebra' provides a generic
  3705 interface.
  3706 
  3707 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3708 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3709 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3710 be a tuple pattern.
  3711 
  3712 Some new syntax forms are available:
  3713 
  3714   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3715   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3716   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3717   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3718 
  3719 The latter form "\<Sum>x < k. e" used to be based on a separate
  3720 function "Summation", which has been discontinued.
  3721 
  3722 * theory Finite_Set: in structured induction proofs, the insert case
  3723 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3724 (insert F x)'.
  3725 
  3726 * The 'refute' command has been extended to support a much larger
  3727 fragment of HOL, including axiomatic type classes, constdefs and
  3728 typedefs, inductive datatypes and recursion.
  3729 
  3730 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3731 Requires zChaff with proof generation to be installed.  See
  3732 HOL/ex/SAT_Examples.thy for examples.
  3733 
  3734 * Datatype induction via method 'induct' now preserves the name of the
  3735 induction variable. For example, when proving P(xs::'a list) by
  3736 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3737 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3738 in unstructured proof scripts.
  3739 
  3740 * Reworked implementation of records.  Improved scalability for
  3741 records with many fields, avoiding performance problems for type
  3742 inference. Records are no longer composed of nested field types, but
  3743 of nested extension types. Therefore the record type only grows linear
  3744 in the number of extensions and not in the number of fields.  The
  3745 top-level (users) view on records is preserved.  Potential
  3746 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3747 old record representation. The type generated for a record is called
  3748 <record_name>_ext_type.
  3749 
  3750 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3751 proofs triggered by a record definition or a simproc (if
  3752 quick_and_dirty is enabled).  Definitions of large records can take
  3753 quite long.
  3754 
  3755 New simproc record_upd_simproc for simplification of multiple record
  3756 updates enabled by default.  Moreover, trivial updates are also
  3757 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3758 occasionally, since simplification is more powerful by default.
  3759 
  3760 * typedef: proper support for polymorphic sets, which contain extra
  3761 type-variables in the term.
  3762 
  3763 * Simplifier: automatically reasons about transitivity chains
  3764 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3765 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3766 old proofs break occasionally as simplification may now solve more
  3767 goals than previously.
  3768 
  3769 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3770 present.  Works for all partial orders (class "order"), in particular
  3771 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3772 just like y <= x.
  3773 
  3774 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3775 bound variable or a constant then the let is unfolded.  Otherwise
  3776 first a is simplified to b, and then f b is simplified to g. If
  3777 possible we abstract b from g arriving at "let x = b in h x",
  3778 otherwise we unfold the let and arrive at g.  The simproc can be
  3779 enabled/disabled by the reference use_let_simproc.  Potential
  3780 INCOMPATIBILITY since simplification is more powerful by default.
  3781 
  3782 * Classical reasoning: the meson method now accepts theorems as arguments.
  3783 
  3784 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3785 jobs to provide advice on the provability of subgoals.
  3786 
  3787 * Theory OrderedGroup and Ring_and_Field: various additions and
  3788 improvements to faciliate calculations involving equalities and
  3789 inequalities.
  3790 
  3791 The following theorems have been eliminated or modified
  3792 (INCOMPATIBILITY):
  3793 
  3794   abs_eq             now named abs_of_nonneg
  3795   abs_of_ge_0        now named abs_of_nonneg
  3796   abs_minus_eq       now named abs_of_nonpos
  3797   imp_abs_id         now named abs_of_nonneg
  3798   imp_abs_neg_id     now named abs_of_nonpos
  3799   mult_pos           now named mult_pos_pos
  3800   mult_pos_le        now named mult_nonneg_nonneg
  3801   mult_pos_neg_le    now named mult_nonneg_nonpos
  3802   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3803   mult_neg           now named mult_neg_neg
  3804   mult_neg_le        now named mult_nonpos_nonpos
  3805 
  3806 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3807      
  3808      zero_le_square
  3809      not_square_less_zero 
  3810 
  3811   The following lemmas have been deleted from Real/RealPow:
  3812   
  3813      realpow_zero_zero
  3814      realpow_two
  3815      realpow_less
  3816      zero_le_power
  3817      realpow_two_le
  3818      abs_realpow_two
  3819      realpow_two_abs     
  3820 
  3821 * Theory Parity: added rules for simplifying exponents.
  3822 
  3823 * Theory List:
  3824 
  3825 The following theorems have been eliminated or modified
  3826 (INCOMPATIBILITY):
  3827 
  3828   list_all_Nil       now named list_all.simps(1)
  3829   list_all_Cons      now named list_all.simps(2)
  3830   list_all_conv      now named list_all_iff
  3831   set_mem_eq         now named mem_iff
  3832 
  3833 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3834 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3835 
  3836 
  3837 *** HOL-Complex ***
  3838 
  3839 * Theory RealDef: better support for embedding natural numbers and
  3840 integers in the reals.
  3841 
  3842 The following theorems have been eliminated or modified
  3843 (INCOMPATIBILITY):
  3844 
  3845   exp_ge_add_one_self  now requires no hypotheses
  3846   real_of_int_add      reversed direction of equality (use [symmetric])
  3847   real_of_int_minus    reversed direction of equality (use [symmetric])
  3848   real_of_int_diff     reversed direction of equality (use [symmetric])
  3849   real_of_int_mult     reversed direction of equality (use [symmetric])
  3850 
  3851 * Theory RComplete: expanded support for floor and ceiling functions.
  3852 
  3853 * Theory Ln is new, with properties of the natural logarithm
  3854 
  3855 * Hyperreal: There is a new type constructor "star" for making
  3856 nonstandard types.  The old type names are now type synonyms:
  3857 
  3858   hypreal = real star
  3859   hypnat = nat star
  3860   hcomplex = complex star
  3861 
  3862 * Hyperreal: Many groups of similarly-defined constants have been
  3863 replaced by polymorphic versions (INCOMPATIBILITY):
  3864 
  3865   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3866 
  3867   starset      <-- starsetNat, starsetC
  3868   *s*          <-- *sNat*, *sc*
  3869   starset_n    <-- starsetNat_n, starsetC_n
  3870   *sn*         <-- *sNatn*, *scn*
  3871   InternalSets <-- InternalNatSets, InternalCSets
  3872 
  3873   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3874   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3875   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3876   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3877   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3878 
  3879 * Hyperreal: Many type-specific theorems have been removed in favor of
  3880 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3881 
  3882   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3883   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3884   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3885   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3886   right_minus <-- hypreal_add_minus
  3887   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3888   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3889   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3890   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3891   mult_1_right <-- hcomplex_mult_one_right
  3892   mult_zero_left <-- hcomplex_mult_zero_left
  3893   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3894   right_distrib <-- hypnat_add_mult_distrib2
  3895   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3896   right_inverse <-- hypreal_mult_inverse
  3897   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3898   order_refl <-- {hypreal,hypnat}_le_refl
  3899   order_trans <-- {hypreal,hypnat}_le_trans
  3900   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3901   order_less_le <-- {hypreal,hypnat}_less_le
  3902   linorder_linear <-- {hypreal,hypnat}_le_linear
  3903   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3904   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3905   add_nonneg_nonneg <-- hypreal_le_add_order
  3906 
  3907 * Hyperreal: Separate theorems having to do with type-specific
  3908 versions of constants have been merged into theorems that apply to the
  3909 new polymorphic constants (INCOMPATIBILITY):
  3910 
  3911   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3912   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3913   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3914   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3915   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3916   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3917   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3918   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3919   STAR_diff <-- {STAR,STARC}_diff
  3920   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3921     STARC_hcomplex_of_complex}_image_subset
  3922   starset_n_Un <-- starset{Nat,C}_n_Un
  3923   starset_n_Int <-- starset{Nat,C}_n_Int
  3924   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3925   starset_n_diff <-- starset{Nat,C}_n_diff
  3926   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3927   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3928   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3929   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3930   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3931   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3932   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3933   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3934   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3935   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3936   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3937   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3938   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3939   starfun_diff <-- starfun{C,RC,CR}_diff
  3940   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3941   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3942   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3943   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3944   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3945   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3946   starfun_Id <-- starfunC_Id
  3947   starfun_approx <-- starfun{Nat,CR}_approx
  3948   starfun_capprox <-- starfun{C,RC}_capprox
  3949   starfun_abs <-- starfunNat_rabs
  3950   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3951   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3952   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3953   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3954   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3955   starfun_add_approx <-- starfunCR_add_approx
  3956   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3957   starfun_divide <-- starfun{C,CR,RC}_divide
  3958   starfun_n <-- starfun{Nat,C}_n
  3959   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3960   starfun_n_add <-- starfun{Nat,C}_n_add
  3961   starfun_n_add_minus <-- starfunNat_n_add_minus
  3962   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3963   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3964   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3965 
  3966   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3967   star_n_minus <-- {hypreal,hcomplex}_minus
  3968   star_n_diff <-- {hypreal,hcomplex}_diff
  3969   star_n_mult <-- {hypreal,hcomplex}_mult
  3970   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3971   star_n_le <-- {hypreal,hypnat}_le
  3972   star_n_less <-- {hypreal,hypnat}_less
  3973   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3974   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3975   star_n_abs <-- hypreal_hrabs
  3976   star_n_divide <-- hcomplex_divide
  3977 
  3978   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3979   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3980   star_of_diff <-- hypreal_of_real_diff
  3981   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3982   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3983   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3984   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3985   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3986   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3987   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3988   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3989   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3990   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3991   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3992   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3993   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3994   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3995   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3996   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3997   star_of_power <-- hypreal_of_real_power
  3998   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3999 
  4000 * Hyperreal: new method "transfer" that implements the transfer
  4001 principle of nonstandard analysis. With a subgoal that mentions
  4002 nonstandard types like "'a star", the command "apply transfer"
  4003 replaces it with an equivalent one that mentions only standard types.
  4004 To be successful, all free variables must have standard types; non-
  4005 standard variables must have explicit universal quantifiers.
  4006 
  4007 * Hyperreal: A theory of Taylor series.
  4008 
  4009 
  4010 *** HOLCF ***
  4011 
  4012 * Discontinued special version of 'constdefs' (which used to support
  4013 continuous functions) in favor of the general Pure one with full
  4014 type-inference.
  4015 
  4016 * New simplification procedure for solving continuity conditions; it
  4017 is much faster on terms with many nested lambda abstractions (cubic
  4018 instead of exponential time).
  4019 
  4020 * New syntax for domain package: selector names are now optional.
  4021 Parentheses should be omitted unless argument is lazy, for example:
  4022 
  4023   domain 'a stream = cons "'a" (lazy "'a stream")
  4024 
  4025 * New command 'fixrec' for defining recursive functions with pattern
  4026 matching; defining multiple functions with mutual recursion is also
  4027 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4028 sinr, or any data constructor defined by the domain package. The given
  4029 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4030 syntax and examples.
  4031 
  4032 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4033 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4034 but the proof obligation additionally includes an admissibility
  4035 requirement. The packages generate instances of class cpo or pcpo,
  4036 with continuity and strictness theorems for Rep and Abs.
  4037 
  4038 * HOLCF: Many theorems have been renamed according to a more standard naming
  4039 scheme (INCOMPATIBILITY):
  4040 
  4041   foo_inject:  "foo$x = foo$y ==> x = y"
  4042   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4043   foo_less:    "(foo$x << foo$y) = (x << y)"
  4044   foo_strict:  "foo$UU = UU"
  4045   foo_defined: "... ==> foo$x ~= UU"
  4046   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4047 
  4048 
  4049 *** ZF ***
  4050 
  4051 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4052 including the First Isomorphism Theorem (on quotienting by the kernel
  4053 of a homomorphism).
  4054 
  4055 * ZF/Simplifier: install second copy of type solver that actually
  4056 makes use of TC rules declared to Isar proof contexts (or locales);
  4057 the old version is still required for ML proof scripts.
  4058 
  4059 
  4060 *** Cube ***
  4061 
  4062 * Converted to Isar theory format; use locales instead of axiomatic
  4063 theories.
  4064 
  4065 
  4066 *** ML ***
  4067 
  4068 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4069 for ||>, ||>>, |>>,
  4070 
  4071 * Pure/library.ML no longer defines its own option datatype, but uses
  4072 that of the SML basis, which has constructors NONE and SOME instead of
  4073 None and Some, as well as exception Option.Option instead of OPTION.
  4074 The functions the, if_none, is_some, is_none have been adapted
  4075 accordingly, while Option.map replaces apsome.
  4076 
  4077 * Pure/library.ML: the exception LIST has been given up in favour of
  4078 the standard exceptions Empty and Subscript, as well as
  4079 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4080 superceded by the standard hd and tl functions etc.
  4081 
  4082 A number of basic list functions are no longer exported to the ML
  4083 toplevel, as they are variants of predefined functions.  The following
  4084 suggests how one can translate existing code:
  4085 
  4086     rev_append xs ys = List.revAppend (xs, ys)
  4087     nth_elem (i, xs) = List.nth (xs, i)
  4088     last_elem xs = List.last xs
  4089     flat xss = List.concat xss
  4090     seq fs = List.app fs
  4091     partition P xs = List.partition P xs
  4092     mapfilter f xs = List.mapPartial f xs
  4093 
  4094 * Pure/library.ML: several combinators for linear functional
  4095 transformations, notably reverse application and composition:
  4096 
  4097   x |> f                f #> g
  4098   (x, y) |-> f          f #-> g
  4099 
  4100 * Pure/library.ML: introduced/changed precedence of infix operators:
  4101 
  4102   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4103   infix 2 ?;
  4104   infix 3 o oo ooo oooo;
  4105   infix 4 ~~ upto downto;
  4106 
  4107 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4108 infix operators.
  4109 
  4110 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4111 fold_map support linear functional transformations and nesting.  For
  4112 example:
  4113 
  4114   fold f [x1, ..., xN] y =
  4115     y |> f x1 |> ... |> f xN
  4116 
  4117   (fold o fold) f [xs1, ..., xsN] y =
  4118     y |> fold f xs1 |> ... |> fold f xsN
  4119 
  4120   fold f [x1, ..., xN] =
  4121     f x1 #> ... #> f xN
  4122 
  4123   (fold o fold) f [xs1, ..., xsN] =
  4124     fold f xs1 #> ... #> fold f xsN
  4125 
  4126 * Pure/library.ML: the following selectors on type 'a option are
  4127 available:
  4128 
  4129   the:               'a option -> 'a  (*partial*)
  4130   these:             'a option -> 'a  where 'a = 'b list
  4131   the_default: 'a -> 'a option -> 'a
  4132   the_list:          'a option -> 'a list
  4133 
  4134 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4135 basic operations for association lists, following natural argument
  4136 order; moreover the explicit equality predicate passed here avoids
  4137 potentially expensive polymorphic runtime equality checks.
  4138 The old functions may be expressed as follows:
  4139 
  4140   assoc = uncurry (AList.lookup (op =))
  4141   assocs = these oo AList.lookup (op =)
  4142   overwrite = uncurry (AList.update (op =)) o swap
  4143 
  4144 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4145 
  4146   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4147   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4148 
  4149 replacing make_keylist and keyfilter (occassionally used)
  4150 Naive rewrites:
  4151 
  4152   make_keylist = AList.make
  4153   keyfilter = AList.find (op =)
  4154 
  4155 * eq_fst and eq_snd now take explicit equality parameter, thus
  4156   avoiding eqtypes. Naive rewrites:
  4157 
  4158     eq_fst = eq_fst (op =)
  4159     eq_snd = eq_snd (op =)
  4160 
  4161 * Removed deprecated apl and apr (rarely used).
  4162   Naive rewrites:
  4163 
  4164     apl (n, op) =>>= curry op n
  4165     apr (op, m) =>>= fn n => op (n, m)
  4166 
  4167 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4168 provides a reasonably efficient light-weight implementation of sets as
  4169 lists.
  4170 
  4171 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4172 few new operations; existing lookup and update are now curried to
  4173 follow natural argument order (for use with fold etc.);
  4174 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4175 
  4176 * Pure/General: output via the Isabelle channels of
  4177 writeln/warning/error etc. is now passed through Output.output, with a
  4178 hook for arbitrary transformations depending on the print_mode
  4179 (cf. Output.add_mode -- the first active mode that provides a output
  4180 function wins).  Already formatted output may be embedded into further
  4181 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4182 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4183 accommodate easy composition of diagnostic messages etc.  Programmers
  4184 rarely need to care about Output.output or Output.raw at all, with
  4185 some notable exceptions: Output.output is required when bypassing the
  4186 standard channels (writeln etc.), or in token translations to produce
  4187 properly formatted results; Output.raw is required when capturing
  4188 already output material that will eventually be presented to the user
  4189 a second time.  For the default print mode, both Output.output and
  4190 Output.raw have no effect.
  4191 
  4192 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4193 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4194 cumulative results are displayed at the end of a batch session.
  4195 
  4196 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4197 replaced by File.platform_path and File.shell_path (with appropriate
  4198 hooks).  This provides a clean interface for unusual systems where the
  4199 internal and external process view of file names are different.
  4200 
  4201 * Pure: more efficient orders for basic syntactic entities: added
  4202 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4203 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4204 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4205 orders now -- potential INCOMPATIBILITY for code that depends on a
  4206 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4207 Library.sort_strings on result).
  4208 
  4209 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4210 fold_types traverse types/terms from left to right, observing natural
  4211 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4212 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4213 
  4214 * Pure: name spaces have been refined, with significant changes of the
  4215 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4216 to extern(_table).  The plain name entry path is superceded by a
  4217 general 'naming' context, which also includes the 'policy' to produce
  4218 a fully qualified name and external accesses of a fully qualified
  4219 name; NameSpace.extend is superceded by context dependent
  4220 Sign.declare_name.  Several theory and proof context operations modify
  4221 the naming context.  Especially note Theory.restore_naming and
  4222 ProofContext.restore_naming to get back to a sane state; note that
  4223 Theory.add_path is no longer sufficient to recover from
  4224 Theory.absolute_path in particular.
  4225 
  4226 * Pure: new flags short_names (default false) and unique_names
  4227 (default true) for controlling output of qualified names.  If
  4228 short_names is set, names are printed unqualified.  If unique_names is
  4229 reset, the name prefix is reduced to the minimum required to achieve
  4230 the original result when interning again, even if there is an overlap
  4231 with earlier declarations.
  4232 
  4233 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4234 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4235 (useful for printing error messages).  INCOMPATIBILITY.
  4236 
  4237 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4238 Theory.theory are now identified, referring to the universal
  4239 Context.theory (see Pure/context.ML).  Actual signature and theory
  4240 content is managed as theory data.  The old code and interfaces were
  4241 spread over many files and structures; the new arrangement introduces
  4242 considerable INCOMPATIBILITY to gain more clarity:
  4243 
  4244   Context -- theory management operations (name, identity, inclusion,
  4245     parents, ancestors, merge, etc.), plus generic theory data;
  4246 
  4247   Sign -- logical signature and syntax operations (declaring consts,
  4248     types, etc.), plus certify/read for common entities;
  4249 
  4250   Theory -- logical theory operations (stating axioms, definitions,
  4251     oracles), plus a copy of logical signature operations (consts,
  4252     types, etc.); also a few basic management operations (Theory.copy,
  4253     Theory.merge, etc.)
  4254 
  4255 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4256 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4257 for convenience -- they merely return the theory.
  4258 
  4259 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4260 
  4261 * Pure: the Isar proof context type is already defined early in Pure
  4262 as Context.proof (note that ProofContext.context and Proof.context are
  4263 aliases, where the latter is the preferred name).  This enables other
  4264 Isabelle components to refer to that type even before Isar is present.
  4265 
  4266 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4267 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4268 any of these kinds.  For example, Sign.intern typeK is now
  4269 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4270 Theory.hide_types.  Also note that former
  4271 Theory.hide_classes/types/consts are now
  4272 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4273 internalize their arguments!  INCOMPATIBILITY.
  4274 
  4275 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4276 datatype thmref (with constructors Name and NameSelection) instead of
  4277 plain string -- INCOMPATIBILITY;
  4278 
  4279 * Pure: cases produced by proof methods specify options, where NONE
  4280 means to remove case bindings -- INCOMPATIBILITY in
  4281 (RAW_)METHOD_CASES.
  4282 
  4283 * Pure: the following operations retrieve axioms or theorems from a
  4284 theory node or theory hierarchy, respectively:
  4285 
  4286   Theory.axioms_of: theory -> (string * term) list
  4287   Theory.all_axioms_of: theory -> (string * term) list
  4288   PureThy.thms_of: theory -> (string * thm) list
  4289   PureThy.all_thms_of: theory -> (string * thm) list
  4290 
  4291 * Pure: print_tac now outputs the goal through the trace channel.
  4292 
  4293 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4294 Reference Toplevel.debug (default false) controls detailed printing
  4295 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4296 controls execution profiling -- set to 1 for time and 2 for space
  4297 (both increase the runtime).
  4298 
  4299 * Isar session: The initial use of ROOT.ML is now always timed,
  4300 i.e. the log will show the actual process times, in contrast to the
  4301 elapsed wall-clock time that the outer shell wrapper produces.
  4302 
  4303 * Simplifier: improved handling of bound variables (nameless
  4304 representation, avoid allocating new strings).  Simprocs that invoke
  4305 the Simplifier recursively should use Simplifier.inherit_bounds to
  4306 avoid local name clashes.  Failure to do so produces warnings
  4307 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4308 for further details.
  4309 
  4310 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4311 bindings for all theorems stored within a given theory; this may help
  4312 in porting non-Isar theories to Isar ones, while keeping ML proof
  4313 scripts for the time being.
  4314 
  4315 * ML operator HTML.with_charset specifies the charset begin used for
  4316 generated HTML files.  For example:
  4317 
  4318   HTML.with_charset "utf-8" use_thy "Hebrew";
  4319   HTML.with_charset "utf-8" use_thy "Chinese";
  4320 
  4321 
  4322 *** System ***
  4323 
  4324 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4325 isabelle, isatool etc.).
  4326 
  4327 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4328 isatool doc, isatool mkdir, display_drafts etc.).
  4329 
  4330 * isatool usedir: option -f allows specification of the ML file to be
  4331 used by Isabelle; default is ROOT.ML.
  4332 
  4333 * New isatool version outputs the version identifier of the Isabelle
  4334 distribution being used.
  4335 
  4336 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4337 (containing Boolean satisfiability problems) into Isabelle/HOL
  4338 theories.
  4339 
  4340 
  4341 
  4342 New in Isabelle2004 (April 2004)
  4343 --------------------------------
  4344 
  4345 *** General ***
  4346 
  4347 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4348   Replaces linorder.ML.
  4349 
  4350 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4351   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4352   (\<a>...\<z>), are now considered normal letters, and can therefore
  4353   be used anywhere where an ASCII letter (a...zA...Z) has until
  4354   now. COMPATIBILITY: This obviously changes the parsing of some
  4355   terms, especially where a symbol has been used as a binder, say
  4356   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4357   as an identifier.  Fix it by inserting a space around former
  4358   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4359   existing theory and ML files.
  4360 
  4361 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4362 
  4363 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4364   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4365   a normal (but invisible) letter. For multiple letter subscripts repeat
  4366   \<^isub> like this: x\<^isub>1\<^isub>2.
  4367 
  4368 * Pure: There are now sub-/superscripts that can span more than one
  4369   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4370   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4371   superscript. The new control characters are not identifier parts.
  4372 
  4373 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4374   content of "..." to the latex file instead of \isacntrl... . The "..."
  4375   may consist of any printable characters excluding the end bracket >.
  4376 
  4377 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4378   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4379   declare constants "final", which prevents their being given a definition
  4380   later.  It is useful for constants whose behaviour is fixed axiomatically
  4381   rather than definitionally, such as the meta-logic connectives.
  4382 
  4383 * Pure: 'instance' now handles general arities with general sorts
  4384   (i.e. intersections of classes),
  4385 
  4386 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4387   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4388   It can be changed to alter the colors/layout of generated pages.
  4389 
  4390 
  4391 *** Isar ***
  4392 
  4393 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4394   cut_tac, subgoal_tac and thin_tac:
  4395   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4396     locales are no longer forced to write Isar proof scripts.
  4397     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4398     emulations.
  4399   - INCOMPATIBILITY: names of variables to be instantiated may no
  4400     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4401     This is consistent with the instantiation attribute "where".
  4402 
  4403 * Attributes "where" and "of":
  4404   - Now take type variables of instantiated theorem into account when reading
  4405     the instantiation string.  This fixes a bug that caused instantiated
  4406     theorems to have too special types in some circumstances.
  4407   - "where" permits explicit instantiations of type variables.
  4408 
  4409 * Calculation commands "moreover" and "also" no longer interfere with
  4410   current facts ("this"), admitting arbitrary combinations with "then"
  4411   and derived forms.
  4412 
  4413 * Locales:
  4414   - Goal statements involving the context element "includes" no longer
  4415     generate theorems with internal delta predicates (those ending on
  4416     "_axioms") in the premise.
  4417     Resolve particular premise with <locale>.intro to obtain old form.
  4418   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4419     specification and "includes" elements in goal statement.
  4420   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4421     [intro?] and [elim?] (respectively) by default.
  4422   - Experimental command for instantiation of locales in proof contexts:
  4423         instantiate <label>[<attrs>]: <loc>
  4424     Instantiates locale <loc> and adds all its theorems to the current context
  4425     taking into account their attributes.  Label and attrs are optional
  4426     modifiers, like in theorem declarations.  If present, names of
  4427     instantiated theorems are qualified with <label>, and the attributes
  4428     <attrs> are applied after any attributes these theorems might have already.
  4429       If the locale has assumptions, a chained fact of the form
  4430     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4431     are derived.  The command does not support old-style locales declared
  4432     with "locale (open)".
  4433       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4434 
  4435 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4436   (Isar) contexts.
  4437 
  4438 
  4439 *** HOL ***
  4440 
  4441 * Proof import: new image HOL4 contains the imported library from
  4442   the HOL4 system with about 2500 theorems. It is imported by
  4443   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4444   can be used like any other Isabelle image.  See
  4445   HOL/Import/HOL/README for more information.
  4446 
  4447 * Simplifier:
  4448   - Much improved handling of linear and partial orders.
  4449     Reasoners for linear and partial orders are set up for type classes
  4450     "linorder" and "order" respectively, and are added to the default simpset
  4451     as solvers.  This means that the simplifier can build transitivity chains
  4452     to solve goals from the assumptions.
  4453   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4454     of blast or auto after simplification become unnecessary because the goal
  4455     is solved by simplification already.
  4456 
  4457 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4458     all proved in axiomatic type classes for semirings, rings and fields.
  4459 
  4460 * Numerics:
  4461   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4462     now formalized using the Ring_and_Field theory mentioned above.
  4463   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4464     than before, because now they are set up once in a generic manner.
  4465   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4466     Look for the general versions in Ring_and_Field (and Power if they concern
  4467     exponentiation).
  4468 
  4469 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4470 
  4471 * Records:
  4472   - Record types are now by default printed with their type abbreviation
  4473     instead of the list of all field types. This can be configured via
  4474     the reference "print_record_type_abbr".
  4475   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4476     (not enabled by default).
  4477   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4478     EX x. x = sel r to True (not enabled by default).
  4479   - Tactic "record_split_simp_tac" to split and simplify records added.
  4480 
  4481 * 'specification' command added, allowing for definition by
  4482   specification.  There is also an 'ax_specification' command that
  4483   introduces the new constants axiomatically.
  4484 
  4485 * arith(_tac) is now able to generate counterexamples for reals as well.
  4486 
  4487 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4488 
  4489 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4490   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4491 
  4492 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4493   matrix theory to linear programming.
  4494 
  4495 * Unions and Intersections:
  4496   The latex output syntax of UN and INT has been changed
  4497   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4498   i.e. the index formulae has become a subscript.
  4499   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4500 
  4501 * Unions and Intersections over Intervals:
  4502   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4503   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4504   like in normal math, and corresponding versions for < and for intersection.
  4505 
  4506 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4507   lexicographic dictonary ordering has been added as "lexord".
  4508 
  4509 * ML: the legacy theory structures Int and List have been removed. They had
  4510   conflicted with ML Basis Library structures having the same names.
  4511 
  4512 * 'refute' command added to search for (finite) countermodels.  Only works
  4513   for a fragment of HOL.  The installation of an external SAT solver is
  4514   highly recommended.  See "HOL/Refute.thy" for details.
  4515 
  4516 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4517   formulae under an assignment of free variables to random values.
  4518   In contrast to 'refute', it can deal with inductive datatypes,
  4519   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4520   for examples.
  4521 
  4522 
  4523 *** HOLCF ***
  4524 
  4525 * Streams now come with concatenation and are part of the HOLCF image
  4526 
  4527 
  4528 
  4529 New in Isabelle2003 (May 2003)
  4530 ------------------------------
  4531 
  4532 *** General ***
  4533 
  4534 * Provers/simplifier:
  4535 
  4536   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4537     Assumptions are now subject to complete mutual simplification,
  4538     not just from left to right. The simplifier now preserves
  4539     the order of assumptions.
  4540 
  4541     Potential INCOMPATIBILITY:
  4542 
  4543     -- simp sometimes diverges where the old version did
  4544        not, e.g. invoking simp on the goal
  4545 
  4546         [| P (f x); y = x; f x = f y |] ==> Q
  4547 
  4548        now gives rise to the infinite reduction sequence
  4549 
  4550         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4551 
  4552        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4553        kind of problem.
  4554 
  4555     -- Tactics combining classical reasoner and simplification (such as auto)
  4556        are also affected by this change, because many of them rely on
  4557        simp. They may sometimes diverge as well or yield a different numbers
  4558        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4559        in case of problems. Sometimes subsequent calls to the classical
  4560        reasoner will fail because a preceeding call to the simplifier too
  4561        eagerly simplified the goal, e.g. deleted redundant premises.
  4562 
  4563   - The simplifier trace now shows the names of the applied rewrite rules
  4564 
  4565   - You can limit the number of recursive invocations of the simplifier
  4566     during conditional rewriting (where the simplifie tries to solve the
  4567     conditions before applying the rewrite rule):
  4568     ML "simp_depth_limit := n"
  4569     where n is an integer. Thus you can force termination where previously
  4570     the simplifier would diverge.
  4571 
  4572   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4573 
  4574   - No longer aborts on failed congruence proof.  Instead, the
  4575     congruence is ignored.
  4576 
  4577 * Pure: New generic framework for extracting programs from constructive
  4578   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4579   as HOL/Extraction for some case studies.
  4580 
  4581 * Pure: The main goal of the proof state is no longer shown by default, only
  4582 the subgoals. This behaviour is controlled by a new flag.
  4583    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4584 (ML: Proof.show_main_goal).
  4585 
  4586 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4587 rules whose conclusion matches subgoal 1:
  4588       PG menu: Isabelle/Isar -> Show me -> matching rules
  4589 The rules are ordered by how closely they match the subgoal.
  4590 In particular, rules that solve a subgoal outright are displayed first
  4591 (or rather last, the way they are printed).
  4592 (ML: ProofGeneral.print_intros())
  4593 
  4594 * Pure: New flag trace_unify_fail causes unification to print
  4595 diagnostic information (PG: in trace buffer) when it fails. This is
  4596 useful for figuring out why single step proofs like rule, erule or
  4597 assumption failed.
  4598 
  4599 * Pure: Locale specifications now produce predicate definitions
  4600 according to the body of text (covering assumptions modulo local
  4601 definitions); predicate "loc_axioms" covers newly introduced text,
  4602 while "loc" is cumulative wrt. all included locale expressions; the
  4603 latter view is presented only on export into the global theory
  4604 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4605 on the old view without predicates;
  4606 
  4607 * Pure: predefined locales "var" and "struct" are useful for sharing
  4608 parameters (as in CASL, for example); just specify something like
  4609 ``var x + var y + struct M'' as import;
  4610 
  4611 * Pure: improved thms_containing: proper indexing of facts instead of
  4612 raw theorems; check validity of results wrt. current name space;
  4613 include local facts of proof configuration (also covers active
  4614 locales), cover fixed variables in index; may use "_" in term
  4615 specification; an optional limit for the number of printed facts may
  4616 be given (the default is 40);
  4617 
  4618 * Pure: disallow duplicate fact bindings within new-style theory files
  4619 (batch-mode only);
  4620 
  4621 * Provers: improved induct method: assumptions introduced by case
  4622 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4623 the goal statement); "foo" still refers to all facts collectively;
  4624 
  4625 * Provers: the function blast.overloaded has been removed: all constants
  4626 are regarded as potentially overloaded, which improves robustness in exchange
  4627 for slight decrease in efficiency;
  4628 
  4629 * Provers/linorder: New generic prover for transitivity reasoning over
  4630 linear orders.  Note: this prover is not efficient!
  4631 
  4632 * Isar: preview of problems to finish 'show' now produce an error
  4633 rather than just a warning (in interactive mode);
  4634 
  4635 
  4636 *** HOL ***
  4637 
  4638 * arith(_tac)
  4639 
  4640  - Produces a counter example if it cannot prove a goal.
  4641    Note that the counter example may be spurious if the goal is not a formula
  4642    of quantifier-free linear arithmetic.
  4643    In ProofGeneral the counter example appears in the trace buffer.
  4644 
  4645  - Knows about div k and mod k where k is a numeral of type nat or int.
  4646 
  4647  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4648    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4649    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4650 
  4651 * simp's arithmetic capabilities have been enhanced a bit: it now
  4652 takes ~= in premises into account (by performing a case split);
  4653 
  4654 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4655 are distributed over a sum of terms;
  4656 
  4657 * New tactic "trans_tac" and method "trans" instantiate
  4658 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4659 "<=", "<" and "=").
  4660 
  4661 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4662 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4663 
  4664 * 'typedef' command has new option "open" to suppress the set
  4665 definition;
  4666 
  4667 * functions Min and Max on finite sets have been introduced (theory
  4668 Finite_Set);
  4669 
  4670 * attribute [symmetric] now works for relations as well; it turns
  4671 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4672 
  4673 * induct over a !!-quantified statement (say !!x1..xn):
  4674   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4675 
  4676 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4677 %x. None. Warning: empty_def now refers to the previously hidden definition
  4678 of the empty set.
  4679 
  4680 * Algebra: formalization of classical algebra.  Intended as base for
  4681 any algebraic development in Isabelle.  Currently covers group theory
  4682 (up to Sylow's theorem) and ring theory (Universal Property of
  4683 Univariate Polynomials).  Contributions welcome;
  4684 
  4685 * GroupTheory: deleted, since its material has been moved to Algebra;
  4686 
  4687 * Complex: new directory of the complex numbers with numeric constants,
  4688 nonstandard complex numbers, and some complex analysis, standard and
  4689 nonstandard (Jacques Fleuriot);
  4690 
  4691 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4692 
  4693 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4694 Fleuriot);
  4695 
  4696 * Real/HahnBanach: updated and adapted to locales;
  4697 
  4698 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4699 Gray and Kramer);
  4700 
  4701 * UNITY: added the Meier-Sanders theory of progress sets;
  4702 
  4703 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4704 as abstract algorithms, instantiated to the JVM;
  4705 
  4706 * Bali: Java source language formalization. Type system, operational
  4707 semantics, axiomatic semantics. Supported language features:
  4708 classes, interfaces, objects,virtual methods, static methods,
  4709 static/instance fields, arrays, access modifiers, definite
  4710 assignment, exceptions.
  4711 
  4712 
  4713 *** ZF ***
  4714 
  4715 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4716 universe, etc.);
  4717 
  4718 * Main ZF: virtually all theories converted to new-style format;
  4719 
  4720 
  4721 *** ML ***
  4722 
  4723 * Pure: Tactic.prove provides sane interface for internal proofs;
  4724 omits the infamous "standard" operation, so this is more appropriate
  4725 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4726 
  4727 * Pure: improved error reporting of simprocs;
  4728 
  4729 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4730 up simprocs;
  4731 
  4732 
  4733 *** Document preparation ***
  4734 
  4735 * uses \par instead of \\ for line breaks in theory text. This may
  4736 shift some page breaks in large documents. To get the old behaviour
  4737 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4738 
  4739 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4740 other packages
  4741 
  4742 * \<euro> now needs package babel/greek instead of marvosym (which
  4743 broke \Rightarrow)
  4744 
  4745 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4746 textcomp package)
  4747 
  4748 
  4749 
  4750 New in Isabelle2002 (March 2002)
  4751 --------------------------------
  4752 
  4753 *** Document preparation ***
  4754 
  4755 * greatly simplified document preparation setup, including more
  4756 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4757 instructive isatool mkdir; users should basically be able to get
  4758 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4759 users may run a separate document processing stage manually like this:
  4760 "isatool usedir -D output HOL Test && isatool document Test/output";
  4761 
  4762 * theory dependency graph may now be incorporated into documents;
  4763 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4764 with \includegraphics of LaTeX;
  4765 
  4766 * proper spacing of consecutive markup elements, especially text
  4767 blocks after section headings;
  4768 
  4769 * support bold style (for single symbols only), input syntax is like
  4770 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4771 
  4772 * \<bullet> is now output as bold \cdot by default, which looks much
  4773 better in printed text;
  4774 
  4775 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4776 note that these symbols are currently unavailable in Proof General /
  4777 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4778 
  4779 * isatool latex no longer depends on changed TEXINPUTS, instead
  4780 isatool document copies the Isabelle style files to the target
  4781 location;
  4782 
  4783 
  4784 *** Isar ***
  4785 
  4786 * Pure/Provers: improved proof by cases and induction;
  4787   - 'case' command admits impromptu naming of parameters (such as
  4788     "case (Suc n)");
  4789   - 'induct' method divinates rule instantiation from the inductive
  4790     claim; no longer requires excessive ?P bindings for proper
  4791     instantiation of cases;
  4792   - 'induct' method properly enumerates all possibilities of set/type
  4793     rules; as a consequence facts may be also passed through *type*
  4794     rules without further ado;
  4795   - 'induct' method now derives symbolic cases from the *rulified*
  4796     rule (before it used to rulify cases stemming from the internal
  4797     atomized version); this means that the context of a non-atomic
  4798     statement becomes is included in the hypothesis, avoiding the
  4799     slightly cumbersome show "PROP ?case" form;
  4800   - 'induct' may now use elim-style induction rules without chaining
  4801     facts, using ``missing'' premises from the goal state; this allows
  4802     rules stemming from inductive sets to be applied in unstructured
  4803     scripts, while still benefitting from proper handling of non-atomic
  4804     statements; NB: major inductive premises need to be put first, all
  4805     the rest of the goal is passed through the induction;
  4806   - 'induct' proper support for mutual induction involving non-atomic
  4807     rule statements (uses the new concept of simultaneous goals, see
  4808     below);
  4809   - append all possible rule selections, but only use the first
  4810     success (no backtracking);
  4811   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4812   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4813   - added 'print_induct_rules' (covered by help item in recent Proof
  4814     General versions);
  4815   - moved induct/cases attributes to Pure, methods to Provers;
  4816   - generic method setup instantiated for FOL and HOL;
  4817 
  4818 * Pure: support multiple simultaneous goal statements, for example
  4819 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4820 meta-level mechanism, this acts as if several individual goals had
  4821 been stated separately; in particular common proof methods need to be
  4822 repeated in order to cover all claims; note that a single elimination
  4823 step is *not* sufficient to establish the two conjunctions, so this
  4824 fails:
  4825 
  4826   assume "A & B" then have A and B ..   (*".." fails*)
  4827 
  4828 better use "obtain" in situations as above; alternative refer to
  4829 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4830 
  4831 * Pure: proper integration with ``locales''; unlike the original
  4832 version by Florian Kammller, Isar locales package high-level proof
  4833 contexts rather than raw logical ones (e.g. we admit to include
  4834 attributes everywhere); operations on locales include merge and
  4835 rename; support for implicit arguments (``structures''); simultaneous
  4836 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4837 some examples;
  4838 
  4839 * Pure: the following commands have been ``localized'', supporting a
  4840 target locale specification "(in name)": 'lemma', 'theorem',
  4841 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4842 stored both within the locale and at the theory level (exported and
  4843 qualified by the locale name);
  4844 
  4845 * Pure: theory goals may now be specified in ``long'' form, with
  4846 ad-hoc contexts consisting of arbitrary locale elements. for example
  4847 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4848 definitions may be given, too); the result is a meta-level rule with
  4849 the context elements being discharged in the obvious way;
  4850 
  4851 * Pure: new proof command 'using' allows to augment currently used
  4852 facts after a goal statement ('using' is syntactically analogous to
  4853 'apply', but acts on the goal's facts only); this allows chained facts
  4854 to be separated into parts given before and after a claim, as in
  4855 ``from a and b have C using d and e <proof>'';
  4856 
  4857 * Pure: renamed "antecedent" case to "rule_context";
  4858 
  4859 * Pure: new 'judgment' command records explicit information about the
  4860 object-logic embedding (used by several tools internally); no longer
  4861 use hard-wired "Trueprop";
  4862 
  4863 * Pure: added 'corollary' command;
  4864 
  4865 * Pure: fixed 'token_translation' command;
  4866 
  4867 * Pure: removed obsolete 'exported' attribute;
  4868 
  4869 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4870 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4871 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4872 
  4873 * Pure: method 'atomize' presents local goal premises as object-level
  4874 statements (atomic meta-level propositions); setup controlled via
  4875 rewrite rules declarations of 'atomize' attribute; example
  4876 application: 'induct' method with proper rule statements in improper
  4877 proof *scripts*;
  4878 
  4879 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4880 now consider the syntactic context of assumptions, giving a better
  4881 chance to get type-inference of the arguments right (this is
  4882 especially important for locales);
  4883 
  4884 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4885 mode;
  4886 
  4887 * Pure/obtain: the formal conclusion "thesis", being marked as
  4888 ``internal'', may no longer be reference directly in the text;
  4889 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4890 situations;
  4891 
  4892 * Pure: generic 'sym' attribute which declares a rule both as pure
  4893 'elim?' and for the 'symmetric' operation;
  4894 
  4895 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4896 text; the fixed correlation with particular command syntax has been
  4897 discontinued;
  4898 
  4899 * Pure: new method 'rules' is particularly well-suited for proof
  4900 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4901 but often produces more compact proof terms with less detours;
  4902 
  4903 * Pure/Provers/classical: simplified integration with pure rule
  4904 attributes and methods; the classical "intro?/elim?/dest?"
  4905 declarations coincide with the pure ones; the "rule" method no longer
  4906 includes classically swapped intros; "intro" and "elim" methods no
  4907 longer pick rules from the context; also got rid of ML declarations
  4908 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4909 INCOMPATIBILITY;
  4910 
  4911 * Provers/classical: attribute 'swapped' produces classical inversions
  4912 of introduction rules;
  4913 
  4914 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4915 rules instead of full simplifier context; 'iff' attribute handles
  4916 conditional rules;
  4917 
  4918 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4919 
  4920 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4921 "(permissive)" option to recover old behavior;
  4922 
  4923 * HOL: 'inductive' no longer features separate (collective) attributes
  4924 for 'intros' (was found too confusing);
  4925 
  4926 * HOL: properly declared induction rules less_induct and
  4927 wf_induct_rule;
  4928 
  4929 
  4930 *** HOL ***
  4931 
  4932 * HOL: moved over to sane numeral syntax; the new policy is as
  4933 follows:
  4934 
  4935   - 0 and 1 are polymorphic constants, which are defined on any
  4936   numeric type (nat, int, real etc.);
  4937 
  4938   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4939   binary representation internally;
  4940 
  4941   - type nat has special constructor Suc, and generally prefers Suc 0
  4942   over 1::nat and Suc (Suc 0) over 2::nat;
  4943 
  4944 This change may cause significant problems of INCOMPATIBILITY; here
  4945 are some hints on converting existing sources:
  4946 
  4947   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4948   entities, so expressions involving "-" (unary or binary minus) need
  4949   to be spaced properly;
  4950 
  4951   - existing occurrences of "1" may need to be constraint "1::nat" or
  4952   even replaced by Suc 0; similar for old "2";
  4953 
  4954   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4955 
  4956   - remove all special provisions on numerals in proofs;
  4957 
  4958 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4959 representation (depends on bin_arith_simps in the default context);
  4960 
  4961 * HOL: symbolic syntax for x^2 (numeral 2);
  4962 
  4963 * HOL: the class of all HOL types is now called "type" rather than
  4964 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4965 in axclass/classes, instance/arities, and (usually rare) occurrences
  4966 in typings (of consts etc.); internally the class is called
  4967 "HOL.type", ML programs should refer to HOLogic.typeS;
  4968 
  4969 * HOL/record package improvements:
  4970   - new derived operations "fields" to build a partial record section,
  4971     "extend" to promote a fixed record to a record scheme, and
  4972     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4973     declared as simp by default;
  4974   - shared operations ("more", "fields", etc.) now need to be always
  4975     qualified) --- potential INCOMPATIBILITY;
  4976   - removed "make_scheme" operations (use "make" with "extend") --
  4977     INCOMPATIBILITY;
  4978   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4979   - provides cases/induct rules for use with corresponding Isar
  4980     methods (for concrete records, record schemes, concrete more
  4981     parts, and schematic more parts -- in that order);
  4982   - internal definitions directly based on a light-weight abstract
  4983     theory of product types over typedef rather than datatype;
  4984 
  4985 * HOL: generic code generator for generating executable ML code from
  4986 specifications; specific support for HOL constructs such as inductive
  4987 datatypes and sets, as well as recursive functions; can be invoked
  4988 via 'generate_code' theory section;
  4989 
  4990 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4991 
  4992 * HOL: consolidated and renamed several theories.  In particular:
  4993         Ord.thy has been absorbed into HOL.thy
  4994         String.thy has been absorbed into List.thy
  4995 
  4996 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4997 (beware of argument permutation!);
  4998 
  4999 * HOL: linorder_less_split superseded by linorder_cases;
  5000 
  5001 * HOL/List: "nodups" renamed to "distinct";
  5002 
  5003 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5004 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5005   - Ex_def has changed, now need to use some_eq_ex
  5006 
  5007 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5008 in this (rare) case use:
  5009 
  5010   delSWrapper "split_all_tac"
  5011   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5012 
  5013 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5014 MAY FAIL;
  5015 
  5016 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5017 Isabelle's type classes, ^ on functions and relations has too general
  5018 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5019 necessary to attach explicit type constraints;
  5020 
  5021 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5022 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5023 renamed accordingly (eg "compI" -> "rel_compI").
  5024 
  5025 * HOL: syntax translations now work properly with numerals and records
  5026 expressions;
  5027 
  5028 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5029 of "lam" -- INCOMPATIBILITY;
  5030 
  5031 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5032 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5033 renamed "Product_Type.unit";
  5034 
  5035 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5036 
  5037 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5038 the "cases" method);
  5039 
  5040 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5041 Florian Kammller);
  5042 
  5043 * HOL/IMP: updated and converted to new-style theory format; several
  5044 parts turned into readable document, with proper Isar proof texts and
  5045 some explanations (by Gerwin Klein);
  5046 
  5047 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5048 
  5049 * HOL-Hyperreal is now a logic image;
  5050 
  5051 
  5052 *** HOLCF ***
  5053 
  5054 * Isar: consts/constdefs supports mixfix syntax for continuous
  5055 operations;
  5056 
  5057 * Isar: domain package adapted to new-style theory format, e.g. see
  5058 HOLCF/ex/Dnat.thy;
  5059 
  5060 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5061 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5062 lift.induct_tac, always use UU instead of Undef;
  5063 
  5064 * HOLCF/IMP: updated and converted to new-style theory;
  5065 
  5066 
  5067 *** ZF ***
  5068 
  5069 * Isar: proper integration of logic-specific tools and packages,
  5070 including theory commands '(co)inductive', '(co)datatype',
  5071 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5072 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5073 
  5074 * theory Main no longer includes AC; for the Axiom of Choice, base
  5075 your theory on Main_ZFC;
  5076 
  5077 * the integer library now covers quotients and remainders, with many
  5078 laws relating division to addition, multiplication, etc.;
  5079 
  5080 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5081 typeless version of the formalism;
  5082 
  5083 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5084 format;
  5085 
  5086 * ZF/Induct: new directory for examples of inductive definitions,
  5087 including theory Multiset for multiset orderings; converted to
  5088 new-style theory format;
  5089 
  5090 * ZF: many new theorems about lists, ordinals, etc.;
  5091 
  5092 
  5093 *** General ***
  5094 
  5095 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5096 variable proof controls level of detail: 0 = no proofs (only oracle
  5097 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5098 also ref manual for further ML interfaces;
  5099 
  5100 * Pure/axclass: removed obsolete ML interface
  5101 goal_subclass/goal_arity;
  5102 
  5103 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5104 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5105 separate tokens, so expressions involving minus need to be spaced
  5106 properly;
  5107 
  5108 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5109 rather than "infixl" or "infixr";
  5110 
  5111 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5112 sort constraint specifications in type inference; e.g. "x::_::foo"
  5113 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5114 type variable);
  5115 
  5116 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5117 control output of nested => (types); the default behavior is
  5118 "type_brackets";
  5119 
  5120 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5121 tokens into AST constants;
  5122 
  5123 * Pure/syntax: prefer later declarations of translations and print
  5124 translation functions; potential INCOMPATIBILITY: need to reverse
  5125 multiple declarations for same syntax element constant;
  5126 
  5127 * Pure/show_hyps reset by default (in accordance to existing Isar
  5128 practice);
  5129 
  5130 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5131 addSafter;
  5132 
  5133 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5134 as well;
  5135 
  5136 * system: tested support for MacOS X; should be able to get Isabelle +
  5137 Proof General to work in a plain Terminal after installing Poly/ML
  5138 (e.g. from the Isabelle distribution area) and GNU bash alone
  5139 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5140 support requires further installations, e.g. from
  5141 http://fink.sourceforge.net/);
  5142 
  5143 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5144 
  5145 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5146 of 40 MB), cf. ML_OPTIONS;
  5147 
  5148 * system: Proof General keywords specification is now part of the
  5149 Isabelle distribution (see etc/isar-keywords.el);
  5150 
  5151 * system: support for persistent Proof General sessions (refrain from
  5152 outdating all loaded theories on startup); user may create writable
  5153 logic images like this: ``isabelle -q HOL Test'';
  5154 
  5155 * system: smart selection of Isabelle process versus Isabelle
  5156 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5157 run both "isabelle" and "Isabelle" even if file names are badly
  5158 damaged (executable inspects the case of the first letter of its own
  5159 name); added separate "isabelle-process" and "isabelle-interface";
  5160 
  5161 * system: refrain from any attempt at filtering input streams; no
  5162 longer support ``8bit'' encoding of old isabelle font, instead proper
  5163 iso-latin characters may now be used; the related isatools
  5164 "symbolinput" and "nonascii" have disappeared as well;
  5165 
  5166 * system: removed old "xterm" interface (the print modes "xterm" and
  5167 "xterm_color" are still available for direct use in a suitable
  5168 terminal);
  5169 
  5170 
  5171 
  5172 New in Isabelle99-2 (February 2001)
  5173 -----------------------------------
  5174 
  5175 *** Overview of INCOMPATIBILITIES ***
  5176 
  5177 * HOL: please note that theories in the Library and elsewhere often use the
  5178 new-style (Isar) format; to refer to their theorems in an ML script you must
  5179 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5180 
  5181 * HOL: inductive package no longer splits induction rule aggressively,
  5182 but only as far as specified by the introductions given; the old
  5183 format may be recovered via ML function complete_split_rule or attribute
  5184 'split_rule (complete)';
  5185 
  5186 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5187 gfp_Tarski to gfp_unfold;
  5188 
  5189 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5190 
  5191 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5192 relation); infix "^^" has been renamed "``"; infix "``" has been
  5193 renamed "`"; "univalent" has been renamed "single_valued";
  5194 
  5195 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5196 operation;
  5197 
  5198 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5199 
  5200 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5201 
  5202 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5203 consequence, it is no longer monotonic wrt. the local goal context
  5204 (which is now passed through the inductive cases);
  5205 
  5206 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5207 \<gg> to \<ggreater>;
  5208 
  5209 
  5210 *** Document preparation ***
  5211 
  5212 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5213 available: are "it" for near math-mode best-style output, "sl" for
  5214 slanted text style, and "tt" for plain type-writer; if no
  5215 \isabellestyle command is given, output is according to slanted
  5216 type-writer);
  5217 
  5218 * support sub/super scripts (for single symbols only), input syntax is
  5219 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5220 
  5221 * some more standard symbols; see Appendix A of the system manual for
  5222 the complete list of symbols defined in isabellesym.sty;
  5223 
  5224 * improved isabelle style files; more abstract symbol implementation
  5225 (should now use \isamath{...} and \isatext{...} in custom symbol
  5226 definitions);
  5227 
  5228 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5229 state; Note that presentation of goal states does not conform to
  5230 actual human-readable proof documents.  Please do not include goal
  5231 states into document output unless you really know what you are doing!
  5232 
  5233 * proper indentation of antiquoted output with proportional LaTeX
  5234 fonts;
  5235 
  5236 * no_document ML operator temporarily disables LaTeX document
  5237 generation;
  5238 
  5239 * isatool unsymbolize tunes sources for plain ASCII communication;
  5240 
  5241 
  5242 *** Isar ***
  5243 
  5244 * Pure: Isar now suffers initial goal statements to contain unbound
  5245 schematic variables (this does not conform to actual readable proof
  5246 documents, due to unpredictable outcome and non-compositional proof
  5247 checking); users who know what they are doing may use schematic goals
  5248 for Prolog-style synthesis of proven results;
  5249 
  5250 * Pure: assumption method (an implicit finishing) now handles actual
  5251 rules as well;
  5252 
  5253 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5254 initial goal, declare "that" only as Pure intro (only for single
  5255 steps); the "that" rule assumption may now be involved in implicit
  5256 finishing, thus ".." becomes a feasible for trivial obtains;
  5257 
  5258 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5259 instance proofs may be performed by "..";
  5260 
  5261 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5262 statements as well;
  5263 
  5264 * Pure: more robust selection of calculational rules;
  5265 
  5266 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5267 rule (as well as the assumption rule);
  5268 
  5269 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5270 lemmas, using the graph browser tool;
  5271 
  5272 * Pure: predict failure of "show" in interactive mode;
  5273 
  5274 * Pure: 'thms_containing' now takes actual terms as arguments;
  5275 
  5276 * HOL: improved method 'induct' --- now handles non-atomic goals
  5277 (potential INCOMPATIBILITY); tuned error handling;
  5278 
  5279 * HOL: cases and induct rules now provide explicit hints about the
  5280 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5281 any remaining facts are inserted into the goal verbatim;
  5282 
  5283 * HOL: local contexts (aka cases) may now contain term bindings as
  5284 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5285 the result to be shown in each case;
  5286 
  5287 * HOL: added 'recdef_tc' command;
  5288 
  5289 * isatool convert assists in eliminating legacy ML scripts;
  5290 
  5291 
  5292 *** HOL ***
  5293 
  5294 * HOL/Library: a collection of generic theories to be used together
  5295 with main HOL; the theory loader path already includes this directory
  5296 by default; the following existing theories have been moved here:
  5297 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5298 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5299 
  5300 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5301 modelling and verification task performed in Isabelle/HOL +
  5302 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5303 
  5304 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5305 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5306 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5307 'domain', this makes the theory consistent with mathematical
  5308 literature;
  5309 
  5310 * HOL basics: added overloaded operations "inverse" and "divide"
  5311 (infix "/"), syntax for generic "abs" operation, generic summation
  5312 operator \<Sum>;
  5313 
  5314 * HOL/typedef: simplified package, provide more useful rules (see also
  5315 HOL/subset.thy);
  5316 
  5317 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5318 now expressed as a proper nested rule (old-style tactic scripts may
  5319 require atomize_strip_tac to cope with non-atomic premises);
  5320 
  5321 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5322 to "split_conv" (old name still available for compatibility);
  5323 
  5324 * HOL: improved concrete syntax for strings (e.g. allows translation
  5325 rules with string literals);
  5326 
  5327 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5328  and Fleuriot's mechanization of analysis, including the transcendental
  5329  functions for the reals;
  5330 
  5331 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5332 
  5333 
  5334 *** CTT ***
  5335 
  5336 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5337 "lam" is displayed as TWO lambda-symbols
  5338 
  5339 * CTT: theory Main now available, containing everything (that is, Bool
  5340 and Arith);
  5341 
  5342 
  5343 *** General ***
  5344 
  5345 * Pure: the Simplifier has been implemented properly as a derived rule
  5346 outside of the actual kernel (at last!); the overall performance
  5347 penalty in practical applications is about 50%, while reliability of
  5348 the Isabelle inference kernel has been greatly improved;
  5349 
  5350 * print modes "brackets" and "no_brackets" control output of nested =>
  5351 (types) and ==> (props); the default behaviour is "brackets";
  5352 
  5353 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5354 as assumptions as well;
  5355 
  5356 * system: support Poly/ML 4.0;
  5357 
  5358 * system: isatool install handles KDE version 1 or 2;
  5359 
  5360 
  5361 
  5362 New in Isabelle99-1 (October 2000)
  5363 ----------------------------------
  5364 
  5365 *** Overview of INCOMPATIBILITIES ***
  5366 
  5367 * HOL: simplification of natural numbers is much changed; to partly
  5368 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5369 issue the following ML commands:
  5370 
  5371   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5372   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5373 
  5374 * HOL: simplification no longer dives into case-expressions; this is
  5375 controlled by "t.weak_case_cong" for each datatype t;
  5376 
  5377 * HOL: nat_less_induct renamed to less_induct;
  5378 
  5379 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5380 fixsome to patch .thy and .ML sources automatically;
  5381 
  5382   select_equality  -> some_equality
  5383   select_eq_Ex     -> some_eq_ex
  5384   selectI2EX       -> someI2_ex
  5385   selectI2         -> someI2
  5386   selectI          -> someI
  5387   select1_equality -> some1_equality
  5388   Eps_sym_eq       -> some_sym_eq_trivial
  5389   Eps_eq           -> some_eq_trivial
  5390 
  5391 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5392 
  5393 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5394 instead);
  5395 
  5396 * HOL: the recursion equations generated by 'recdef' are now called
  5397 f.simps instead of f.rules;
  5398 
  5399 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5400 
  5401 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5402 sometimes be needed;
  5403 
  5404 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5405 
  5406 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5407 
  5408 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5409 product is now "<*>" instead of "Times"; the lexicographic product is
  5410 now "<*lex*>" instead of "**";
  5411 
  5412 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5413 of main HOL, but was unused); better use HOL's datatype package;
  5414 
  5415 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5416 the old syntax may be recovered as follows:
  5417 
  5418   syntax (symbols)
  5419     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5420       (infixl "\\<oplus>" 100)
  5421 
  5422 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5423 
  5424 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5425 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5426 internally;
  5427 
  5428 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5429 changed from A/r to A//r;
  5430 
  5431 * ZF: new treatment of arithmetic (nat & int) may break some old
  5432 proofs;
  5433 
  5434 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5435 rulify -> rule_format, elimify -> elim_format, ...);
  5436 
  5437 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5438 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5439 should have to change intro!! to intro? only); replaced "delrule" by
  5440 "rule del";
  5441 
  5442 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5443 
  5444 * Provers: strengthened force_tac by using new first_best_tac;
  5445 
  5446 * LaTeX document preparation: several changes of isabelle.sty (see
  5447 lib/texinputs);
  5448 
  5449 
  5450 *** Document preparation ***
  5451 
  5452 * formal comments (text blocks etc.) in new-style theories may now
  5453 contain antiquotations of thm/prop/term/typ/text to be presented
  5454 according to latex print mode; concrete syntax is like this:
  5455 @{term[show_types] "f(x) = a + x"};
  5456 
  5457 * isatool mkdir provides easy setup of Isabelle session directories,
  5458 including proper document sources;
  5459 
  5460 * generated LaTeX sources are now deleted after successful run
  5461 (isatool document -c); may retain a copy somewhere else via -D option
  5462 of isatool usedir;
  5463 
  5464 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5465 style files, achieving self-contained LaTeX sources and simplifying
  5466 LaTeX debugging;
  5467 
  5468 * old-style theories now produce (crude) LaTeX output as well;
  5469 
  5470 * browser info session directories are now self-contained (may be put
  5471 on WWW server seperately); improved graphs of nested sessions; removed
  5472 graph for 'all sessions';
  5473 
  5474 * several improvements in isabelle style files; \isabellestyle{it}
  5475 produces fake math mode output; \isamarkupheader is now \section by
  5476 default; see lib/texinputs/isabelle.sty etc.;
  5477 
  5478 
  5479 *** Isar ***
  5480 
  5481 * Isar/Pure: local results and corresponding term bindings are now
  5482 subject to Hindley-Milner polymorphism (similar to ML); this
  5483 accommodates incremental type-inference very nicely;
  5484 
  5485 * Isar/Pure: new derived language element 'obtain' supports
  5486 generalized existence reasoning;
  5487 
  5488 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5489 support accumulation of results, without applying any rules yet;
  5490 useful to collect intermediate results without explicit name
  5491 references, and for use with transitivity rules with more than 2
  5492 premises;
  5493 
  5494 * Isar/Pure: scalable support for case-analysis type proofs: new
  5495 'case' language element refers to local contexts symbolically, as
  5496 produced by certain proof methods; internally, case names are attached
  5497 to theorems as "tags";
  5498 
  5499 * Isar/Pure: theory command 'hide' removes declarations from
  5500 class/type/const name spaces;
  5501 
  5502 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5503 indicate potential overloading;
  5504 
  5505 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5506 
  5507 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5508 "{a,b,c}" instead of {a,b,c};
  5509 
  5510 * Isar/Pure now provides its own version of intro/elim/dest
  5511 attributes; useful for building new logics, but beware of confusion
  5512 with the version in Provers/classical;
  5513 
  5514 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5515 case name 'antecedent';
  5516 
  5517 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5518 to the current context is now done automatically);
  5519 
  5520 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5521 for definining proof methods in ML;
  5522 
  5523 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5524 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5525 most cases, one should have to change intro!! to intro? only);
  5526 replaced "delrule" by "rule del";
  5527 
  5528 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5529 'symmetric' attribute (the latter supercedes [RS sym]);
  5530 
  5531 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5532 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5533 well (including splits);
  5534 
  5535 * Isar/Provers: Simplifier and Classical methods now support all kind
  5536 of modifiers used in the past, including 'cong', 'iff', etc.
  5537 
  5538 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5539 of Simplifier and Classical reasoner);
  5540 
  5541 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5542 now support named cases; major packages (inductive, datatype, primrec,
  5543 recdef) support case names and properly name parameters;
  5544 
  5545 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5546 monotonicity conditions are extracted to be proven at end of
  5547 calculations;
  5548 
  5549 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5550 method anyway;
  5551 
  5552 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5553 split_if split_if_asm; datatype package provides theorems foo.splits =
  5554 foo.split foo.split_asm for each datatype;
  5555 
  5556 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5557 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5558 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5559 use "(cases (simplified))" method in proper proof texts);
  5560 
  5561 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5562 
  5563 * Isar: names of theorems etc. may be natural numbers as well;
  5564 
  5565 * Isar: 'pr' command: optional arguments for goals_limit and
  5566 ProofContext.prems_limit; no longer prints theory contexts, but only
  5567 proof states;
  5568 
  5569 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5570 additional print modes to be specified; e.g. "pr(latex)" will print
  5571 proof state according to the Isabelle LaTeX style;
  5572 
  5573 * Isar: improved support for emulating tactic scripts, including proof
  5574 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5575 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5576 (for HOL datatypes);
  5577 
  5578 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5579 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5580 'proof method scripts' have to be in depth-first order;
  5581 
  5582 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5583 
  5584 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5585 should instead use individual commands for printing items
  5586 (print_commands, print_methods etc.);
  5587 
  5588 * Isar: added 'nothing' --- the empty list of theorems;
  5589 
  5590 
  5591 *** HOL ***
  5592 
  5593 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5594 corresponding virtual machine and a specification of its bytecode
  5595 verifier and a lightweight bytecode verifier, including proofs of
  5596 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5597 Cornelia Pusch (see also the homepage of project Bali at
  5598 http://isabelle.in.tum.de/Bali/);
  5599 
  5600 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5601 Clemens Ballarin;
  5602 
  5603 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5604 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5605 Rasmussen;
  5606 
  5607 * HOL/Lattice: fundamental concepts of lattice theory and order
  5608 structures, including duals, properties of bounds versus algebraic
  5609 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5610 Theorem for complete lattices etc.; may also serve as a demonstration
  5611 for abstract algebraic reasoning using axiomatic type classes, and
  5612 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5613 
  5614 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5615 von Oheimb;
  5616 
  5617 * HOL/IMPP: extension of IMP with local variables and mutually
  5618 recursive procedures, by David von Oheimb;
  5619 
  5620 * HOL/Lambda: converted into new-style theory and document;
  5621 
  5622 * HOL/ex/Multiquote: example of multiple nested quotations and
  5623 anti-quotations -- basically a generalized version of de-Bruijn
  5624 representation; very useful in avoiding lifting of operations;
  5625 
  5626 * HOL/record: added general record equality rule to simpset; fixed
  5627 select-update simplification procedure to handle extended records as
  5628 well; admit "r" as field name;
  5629 
  5630 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5631 other numeric types and also as the identity of groups, rings, etc.;
  5632 
  5633 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5634 Types nat and int belong to this axclass;
  5635 
  5636 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5637    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5638    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5639   two terms #m*u and #n*u are replaced by #(m+n)*u
  5640     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5641   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5642     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5643 
  5644 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5645 powerful prover for predicate logic but knows nothing of clasets; see
  5646 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5647 
  5648 * HOL: new version of "case_tac" subsumes both boolean case split and
  5649 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5650 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5651 
  5652 * HOL: simplification no longer dives into case-expressions: only the
  5653 selector expression is simplified, but not the remaining arms; to
  5654 enable full simplification of case-expressions for datatype t, you may
  5655 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5656 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5657 
  5658 * HOL/recdef: the recursion equations generated by 'recdef' for
  5659 function 'f' are now called f.simps instead of f.rules; if all
  5660 termination conditions are proved automatically, these simplification
  5661 rules are added to the simpset, as in primrec; rules may be named
  5662 individually as well, resulting in a separate list of theorems for
  5663 each equation;
  5664 
  5665 * HOL/While is a new theory that provides a while-combinator. It
  5666 permits the definition of tail-recursive functions without the
  5667 provision of a termination measure. The latter is necessary once the
  5668 invariant proof rule for while is applied.
  5669 
  5670 * HOL: new (overloaded) notation for the set of elements below/above
  5671 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5672 
  5673 * HOL: theorems impI, allI, ballI bound as "strip";
  5674 
  5675 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5676 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5677 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5678 
  5679 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5680 
  5681 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5682 main HOL, but was unused);
  5683 
  5684 * HOL: fewer consts declared as global (e.g. have to refer to
  5685 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5686 
  5687 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5688 in case of overlap with user translations (e.g. judgements over
  5689 tuples); (note that the underlying logical represenation is still
  5690 bogus);
  5691 
  5692 
  5693 *** ZF ***
  5694 
  5695 * ZF: simplification automatically cancels common terms in arithmetic
  5696 expressions over nat and int;
  5697 
  5698 * ZF: new treatment of nat to minimize type-checking: all operators
  5699 coerce their operands to a natural number using the function natify,
  5700 making the algebraic laws unconditional;
  5701 
  5702 * ZF: as above, for int: operators coerce their operands to an integer
  5703 using the function intify;
  5704 
  5705 * ZF: the integer library now contains many of the usual laws for the
  5706 orderings, including $<=, and monotonicity laws for $+ and $*;
  5707 
  5708 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5709 simplification;
  5710 
  5711 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5712 to the simplifier and classical reasoner simultaneously;
  5713 
  5714 
  5715 *** General ***
  5716 
  5717 * Provers: blast_tac now handles actual object-logic rules as
  5718 assumptions; note that auto_tac uses blast_tac internally as well;
  5719 
  5720 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5721 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5722 
  5723 * Provers: delrules now handles destruct rules as well (no longer need
  5724 explicit make_elim);
  5725 
  5726 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5727   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5728 use instead the strong form,
  5729   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5730 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5731 from destruct-rules;
  5732 
  5733 * Provers: Simplifier.easy_setup provides a fast path to basic
  5734 Simplifier setup for new object-logics;
  5735 
  5736 * Pure: AST translation rules no longer require constant head on LHS;
  5737 
  5738 * Pure: improved name spaces: ambiguous output is qualified; support
  5739 for hiding of names;
  5740 
  5741 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5742 XSYMBOL_HOME; no longer need to do manual configuration in most
  5743 situations;
  5744 
  5745 * system: compression of ML heaps images may now be controlled via -c
  5746 option of isabelle and isatool usedir (currently only observed by
  5747 Poly/ML);
  5748 
  5749 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5750 useful for remote X11);
  5751 
  5752 * system: provide TAGS file for Isabelle sources;
  5753 
  5754 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5755 order;
  5756 
  5757 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5758 timing flag supersedes proof_timing and Toplevel.trace;
  5759 
  5760 * ML: new combinators |>> and |>>> for incremental transformations
  5761 with secondary results (e.g. certain theory extensions):
  5762 
  5763 * ML: PureThy.add_defs gets additional argument to indicate potential
  5764 overloading (usually false);
  5765 
  5766 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5767 results;
  5768 
  5769 
  5770 
  5771 New in Isabelle99 (October 1999)
  5772 --------------------------------
  5773 
  5774 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5775 
  5776 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5777 are no longer simplified.  (This allows the simplifier to unfold recursive
  5778 functional programs.)  To restore the old behaviour, declare
  5779 
  5780     Delcongs [if_weak_cong];
  5781 
  5782 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5783 complement;
  5784 
  5785 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5786 
  5787 * HOL/datatype: mutual_induct_tac no longer exists --
  5788   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5789 
  5790 * HOL/typedef: fixed type inference for representing set; type
  5791 arguments now have to occur explicitly on the rhs as type constraints;
  5792 
  5793 * ZF: The con_defs part of an inductive definition may no longer refer
  5794 to constants declared in the same theory;
  5795 
  5796 * HOL, ZF: the function mk_cases, generated by the inductive
  5797 definition package, has lost an argument.  To simplify its result, it
  5798 uses the default simpset instead of a supplied list of theorems.
  5799 
  5800 * HOL/List: the constructors of type list are now Nil and Cons;
  5801 
  5802 * Simplifier: the type of the infix ML functions
  5803         setSSolver addSSolver setSolver addSolver
  5804 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5805 for packaging solvers. A solver is created via
  5806         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5807 where the string argument is only a comment.
  5808 
  5809 
  5810 *** Proof tools ***
  5811 
  5812 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5813 decision procedure for linear arithmetic. Currently it is used for
  5814 types `nat', `int', and `real' in HOL (see below); it can, should and
  5815 will be instantiated for other types and logics as well.
  5816 
  5817 * The simplifier now accepts rewrite rules with flexible heads, eg
  5818      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5819   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5820   matching.
  5821 
  5822 
  5823 *** General ***
  5824 
  5825 * New Isabelle/Isar subsystem provides an alternative to traditional
  5826 tactical theorem proving; together with the ProofGeneral/isar user
  5827 interface it offers an interactive environment for developing human
  5828 readable proof documents (Isar == Intelligible semi-automated
  5829 reasoning); for further information see isatool doc isar-ref,
  5830 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5831 
  5832 * improved and simplified presentation of theories: better HTML markup
  5833 (including colors), graph views in several sizes; isatool usedir now
  5834 provides a proper interface for user theories (via -P option); actual
  5835 document preparation based on (PDF)LaTeX is available as well (for
  5836 new-style theories only); see isatool doc system for more information;
  5837 
  5838 * native support for Proof General, both for classic Isabelle and
  5839 Isabelle/Isar;
  5840 
  5841 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5842 using the graph browser tool;
  5843 
  5844 * Isabelle manuals now also available as PDF;
  5845 
  5846 * theory loader rewritten from scratch (may not be fully
  5847 bug-compatible); old loadpath variable has been replaced by show_path,
  5848 add_path, del_path, reset_path functions; new operations such as
  5849 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5850 isatool doc ref);
  5851 
  5852 * improved isatool install: option -k creates KDE application icon,
  5853 option -p DIR installs standalone binaries;
  5854 
  5855 * added ML_PLATFORM setting (useful for cross-platform installations);
  5856 more robust handling of platform specific ML images for SML/NJ;
  5857 
  5858 * the settings environment is now statically scoped, i.e. it is never
  5859 created again in sub-processes invoked from isabelle, isatool, or
  5860 Isabelle;
  5861 
  5862 * path element specification '~~' refers to '$ISABELLE_HOME';
  5863 
  5864 * in locales, the "assumes" and "defines" parts may be omitted if
  5865 empty;
  5866 
  5867 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5868 long arrows);
  5869 
  5870 * new print_mode "HTML";
  5871 
  5872 * new flag show_tags controls display of tags of theorems (which are
  5873 basically just comments that may be attached by some tools);
  5874 
  5875 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5876 mode and goal output format:
  5877 
  5878 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5879 244c244
  5880 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5881 ---
  5882 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5883 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5884 181c181
  5885 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5886 ---
  5887 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5888 
  5889 * function bind_thms stores lists of theorems (cf. bind_thm);
  5890 
  5891 * new shorthand tactics ftac, eatac, datac, fatac;
  5892 
  5893 * qed (and friends) now accept "" as result name; in that case the
  5894 theorem is not stored, but proper checks and presentation of the
  5895 result still apply;
  5896 
  5897 * theorem database now also indexes constants "Trueprop", "all",
  5898 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5899 
  5900 
  5901 *** HOL ***
  5902 
  5903 ** HOL arithmetic **
  5904 
  5905 * There are now decision procedures for linear arithmetic over nat and
  5906 int:
  5907 
  5908 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5909 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5910 are treated as atomic; subformulae not involving type `nat' or `int'
  5911 are ignored; quantified subformulae are ignored unless they are
  5912 positive universal or negative existential. The tactic has to be
  5913 invoked by hand and can be a little bit slow. In particular, the
  5914 running time is exponential in the number of occurrences of `min' and
  5915 `max', and `-' on `nat'.
  5916 
  5917 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5918 (negated) (in)equalities among the premises and the conclusion into
  5919 account (i.e. no compound formulae) and does not know about `min' and
  5920 `max', and `-' on `nat'. It is fast and is used automatically by the
  5921 simplifier.
  5922 
  5923 NB: At the moment, these decision procedures do not cope with mixed
  5924 nat/int formulae where the two parts interact, such as `m < n ==>
  5925 int(m) < int(n)'.
  5926 
  5927 * HOL/Numeral provides a generic theory of numerals (encoded
  5928 efficiently as bit strings); setup for types nat/int/real is in place;
  5929 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5930 int, existing theories and proof scripts may require a few additional
  5931 type constraints;
  5932 
  5933 * integer division and remainder can now be performed on constant
  5934 arguments;
  5935 
  5936 * many properties of integer multiplication, division and remainder
  5937 are now available;
  5938 
  5939 * An interface to the Stanford Validity Checker (SVC) is available through the
  5940 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5941 are proved automatically.  SVC must be installed separately, and its results
  5942 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5943 invocation of the underlying oracle).  For SVC see
  5944   http://verify.stanford.edu/SVC
  5945 
  5946 * IsaMakefile: the HOL-Real target now builds an actual image;
  5947 
  5948 
  5949 ** HOL misc **
  5950 
  5951 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5952 (in Isabelle/Isar) -- by Gertrud Bauer;
  5953 
  5954 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5955 analysis for assembly languages with subtypes;
  5956 
  5957 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5958 -- avoids syntactic ambiguities and treats state, transition, and
  5959 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5960 changed syntax and (many) tactics;
  5961 
  5962 * HOL/inductive: Now also handles more general introduction rules such
  5963   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5964   theorems are now maintained within the theory (maintained via the
  5965   "mono" attribute);
  5966 
  5967 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5968   (using function types) such as
  5969 
  5970   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5971 
  5972 * HOL/record: record_simproc (part of the default simpset) takes care
  5973 of selectors applied to updated records; record_split_tac is no longer
  5974 part of the default claset; update_defs may now be removed from the
  5975 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5976 
  5977   claset_ref () := claset() addSWrapper record_split_wrapper;
  5978   Delsimprocs [record_simproc]
  5979 
  5980 * HOL/typedef: fixed type inference for representing set; type
  5981 arguments now have to occur explicitly on the rhs as type constraints;
  5982 
  5983 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5984 names rather than an ML expression;
  5985 
  5986 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5987 supplied later.  Program schemes can be defined, such as
  5988     "While B C s = (if B s then While B C (C s) else s)"
  5989 where the well-founded relation can be chosen after B and C have been given.
  5990 
  5991 * HOL/List: the constructors of type list are now Nil and Cons;
  5992 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5993 course, ML tools referring to List.list.op # etc. have to be adapted;
  5994 
  5995 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5996 disabled by default; run isabelle with option -m HOL to get back to
  5997 the original Gordon/HOL-style output;
  5998 
  5999 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  6000 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  6001 
  6002 * HOL basic syntax simplified (more orthogonal): all variants of
  6003 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  6004 Eps operator is provided as well: "SOME x. P[x]";
  6005 
  6006 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  6007 
  6008 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  6009 thus available for user theories;
  6010 
  6011 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  6012 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  6013 time;
  6014 
  6015 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  6016 several times and then mp;
  6017 
  6018 
  6019 *** LK ***
  6020 
  6021 * the notation <<...>> is now available as a notation for sequences of
  6022 formulas;
  6023 
  6024 * the simplifier is now installed
  6025 
  6026 * the axiom system has been generalized (thanks to Soren Heilmann)
  6027 
  6028 * the classical reasoner now has a default rule database
  6029 
  6030 
  6031 *** ZF ***
  6032 
  6033 * new primrec section allows primitive recursive functions to be given
  6034 directly (as in HOL) over datatypes and the natural numbers;
  6035 
  6036 * new tactics induct_tac and exhaust_tac for induction (or case
  6037 analysis) over datatypes and the natural numbers;
  6038 
  6039 * the datatype declaration of type T now defines the recursor T_rec;
  6040 
  6041 * simplification automatically does freeness reasoning for datatype
  6042 constructors;
  6043 
  6044 * automatic type-inference, with AddTCs command to insert new
  6045 type-checking rules;
  6046 
  6047 * datatype introduction rules are now added as Safe Introduction rules
  6048 to the claset;
  6049 
  6050 * the syntax "if P then x else y" is now available in addition to
  6051 if(P,x,y);
  6052 
  6053 
  6054 *** Internal programming interfaces ***
  6055 
  6056 * tuned simplifier trace output; new flag debug_simp;
  6057 
  6058 * structures Vartab / Termtab (instances of TableFun) offer efficient
  6059 tables indexed by indexname_ord / term_ord (compatible with aconv);
  6060 
  6061 * AxClass.axclass_tac lost the theory argument;
  6062 
  6063 * tuned current_goals_markers semantics: begin / end goal avoids
  6064 printing empty lines;
  6065 
  6066 * removed prs and prs_fn hook, which was broken because it did not
  6067 include \n in its semantics, forcing writeln to add one
  6068 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  6069 string -> unit if you really want to output text without newline;
  6070 
  6071 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  6072 plain output, interface builders may have to enable 'isabelle_font'
  6073 mode to get Isabelle font glyphs as before;
  6074 
  6075 * refined token_translation interface; INCOMPATIBILITY: output length
  6076 now of type real instead of int;
  6077 
  6078 * theory loader actions may be traced via new ThyInfo.add_hook
  6079 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  6080 your own database of information attached to *whole* theories -- as
  6081 opposed to intra-theory data slots offered via TheoryDataFun;
  6082 
  6083 * proper handling of dangling sort hypotheses (at last!);
  6084 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  6085 extra sort hypotheses that can be witnessed from the type signature;
  6086 the force_strip_shyps flag is gone, any remaining shyps are simply
  6087 left in the theorem (with a warning issued by strip_shyps_warning);
  6088 
  6089 
  6090 
  6091 New in Isabelle98-1 (October 1998)
  6092 ----------------------------------
  6093 
  6094 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6095 
  6096 * several changes of automated proof tools;
  6097 
  6098 * HOL: major changes to the inductive and datatype packages, including
  6099 some minor incompatibilities of theory syntax;
  6100 
  6101 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  6102 called `inj_on';
  6103 
  6104 * HOL: removed duplicate thms in Arith:
  6105   less_imp_add_less  should be replaced by  trans_less_add1
  6106   le_imp_add_le      should be replaced by  trans_le_add1
  6107 
  6108 * HOL: unary minus is now overloaded (new type constraints may be
  6109 required);
  6110 
  6111 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  6112 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  6113 now taken as an integer constant.
  6114 
  6115 * Pure: ML function 'theory_of' renamed to 'theory';
  6116 
  6117 
  6118 *** Proof tools ***
  6119 
  6120 * Simplifier:
  6121   1. Asm_full_simp_tac is now more aggressive.
  6122      1. It will sometimes reorient premises if that increases their power to
  6123         simplify.
  6124      2. It does no longer proceed strictly from left to right but may also
  6125         rotate premises to achieve further simplification.
  6126      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  6127      old Asm_full_simp_tac in that it does not rotate premises.
  6128   2. The simplifier now knows a little bit about nat-arithmetic.
  6129 
  6130 * Classical reasoner: wrapper mechanism for the classical reasoner now
  6131 allows for selected deletion of wrappers, by introduction of names for
  6132 wrapper functionals.  This implies that addbefore, addSbefore,
  6133 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  6134 and that adding two tactics with the same name overwrites the first
  6135 one (emitting a warning).
  6136   type wrapper = (int -> tactic) -> (int -> tactic)
  6137   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  6138   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  6139   delWrapper, delSWrapper: claset *  string            -> claset
  6140   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  6141 
  6142 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  6143 semantics; addbefore now affects only the unsafe part of step_tac
  6144 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  6145 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  6146 by Force_tac;
  6147 
  6148 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  6149 compWrapper; added safe wrapper (and access functions for it);
  6150 
  6151 * HOL/split_all_tac is now much faster and fails if there is nothing
  6152 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  6153 and the names of the automatically generated variables have changed.
  6154 split_all_tac has moved within claset() from unsafe wrappers to safe
  6155 wrappers, which means that !!-bound variables are split much more
  6156 aggressively, and safe_tac and clarify_tac now split such variables.
  6157 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  6158 Note: the same holds for record_split_tac, which does the job of
  6159 split_all_tac for record fields.
  6160 
  6161 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  6162 permanently to the default simpset using Addsplits just like
  6163 Addsimps. They can be removed via Delsplits just like
  6164 Delsimps. Lower-case versions are also available.
  6165 
  6166 * HOL/Simplifier: The rule split_if is now part of the default
  6167 simpset. This means that the simplifier will eliminate all occurrences
  6168 of if-then-else in the conclusion of a goal. To prevent this, you can
  6169 either remove split_if completely from the default simpset by
  6170 `Delsplits [split_if]' or remove it in a specific call of the
  6171 simplifier using `... delsplits [split_if]'.  You can also add/delete
  6172 other case splitting rules to/from the default simpset: every datatype
  6173 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  6174 t is the name of the datatype).
  6175 
  6176 * Classical reasoner / Simplifier combination: new force_tac (and
  6177 derivatives Force_tac, force) combines rewriting and classical
  6178 reasoning (and whatever other tools) similarly to auto_tac, but is
  6179 aimed to solve the given subgoal completely.
  6180 
  6181 
  6182 *** General ***
  6183 
  6184 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  6185 and `goalw': the theory is no longer needed as an explicit argument -
  6186 the current theory context is used; assumptions are no longer returned
  6187 at the ML-level unless one of them starts with ==> or !!; it is
  6188 recommended to convert to these new commands using isatool fixgoal
  6189 (backup your sources first!);
  6190 
  6191 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  6192 the current theory context, and 'theory' to lookup stored theories;
  6193 
  6194 * new theory section 'locale' for declaring constants, assumptions and
  6195 definitions that have local scope;
  6196 
  6197 * new theory section 'nonterminals' for purely syntactic types;
  6198 
  6199 * new theory section 'setup' for generic ML setup functions
  6200 (e.g. package initialization);
  6201 
  6202 * the distribution now includes Isabelle icons: see
  6203 lib/logo/isabelle-{small,tiny}.xpm;
  6204 
  6205 * isatool install - install binaries with absolute references to
  6206 ISABELLE_HOME/bin;
  6207 
  6208 * isatool logo -- create instances of the Isabelle logo (as EPS);
  6209 
  6210 * print mode 'emacs' reserved for Isamode;
  6211 
  6212 * support multiple print (ast) translations per constant name;
  6213 
  6214 * theorems involving oracles are now printed with a suffixed [!];
  6215 
  6216 
  6217 *** HOL ***
  6218 
  6219 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  6220 
  6221 * HOL/inductive package reorganized and improved: now supports mutual
  6222 definitions such as
  6223 
  6224   inductive EVEN ODD
  6225     intrs
  6226       null "0 : EVEN"
  6227       oddI "n : EVEN ==> Suc n : ODD"
  6228       evenI "n : ODD ==> Suc n : EVEN"
  6229 
  6230 new theorem list "elims" contains an elimination rule for each of the
  6231 recursive sets; inductive definitions now handle disjunctive premises
  6232 correctly (also ZF);
  6233 
  6234 INCOMPATIBILITIES: requires Inductive as an ancestor; component