NEWS
author nipkow
Thu May 13 14:34:05 2010 +0200 (2010-05-13)
changeset 36903 489c1fbbb028
parent 36857 59ed53700145
child 36928 637100169bc7
permissions -rw-r--r--
Multiset: renamed, added and tuned lemmas;
Permutation: replaced local "remove" by List.remove1
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Schematic theorem statements need to be explicitly markup as such,
    10 via commands 'schematic_lemma', 'schematic_theorem',
    11 'schematic_corollary'.  Thus the relevance of the proof is made
    12 syntactically clear, which impacts performance in a parallel or
    13 asynchronous interactive environment.  Minor INCOMPATIBILITY.
    14 
    15 * Authentic syntax for *all* logical entities (type classes, type
    16 constructors, term constants): provides simple and robust
    17 correspondence between formal entities and concrete syntax.  Within
    18 the parse tree / AST representations, "constants" are decorated by
    19 their category (class, type, const) and spelled out explicitly with
    20 their full internal name.
    21 
    22 Substantial INCOMPATIBILITY concerning low-level syntax declarations
    23 and translations (translation rules and translation functions in ML).
    24 Some hints on upgrading:
    25 
    26   - Many existing uses of 'syntax' and 'translations' can be replaced
    27     by more modern 'type_notation', 'notation' and 'abbreviation',
    28     which are independent of this issue.
    29 
    30   - 'translations' require markup within the AST; the term syntax
    31     provides the following special forms:
    32 
    33       CONST c   -- produces syntax version of constant c from context
    34       XCONST c  -- literally c, checked as constant from context
    35       c         -- literally c, if declared by 'syntax'
    36 
    37     Plain identifiers are treated as AST variables -- occasionally the
    38     system indicates accidental variables via the error "rhs contains
    39     extra variables".
    40 
    41     Type classes and type constructors are marked according to their
    42     concrete syntax.  Some old translations rules need to be written
    43     for the "type" category, using type constructor application
    44     instead of pseudo-term application of the default category
    45     "logic".
    46 
    47   - 'parse_translation' etc. in ML may use the following
    48     antiquotations:
    49 
    50       @{class_syntax c}   -- type class c within parse tree / AST
    51       @{term_syntax c}    -- type constructor c within parse tree / AST
    52       @{const_syntax c}   -- ML version of "CONST c" above
    53       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
    54 
    55   - Literal types within 'typed_print_translations', i.e. those *not*
    56     represented as pseudo-terms are represented verbatim.  Use @{class
    57     c} or @{type_name c} here instead of the above syntax
    58     antiquotations.
    59 
    60 Note that old non-authentic syntax was based on unqualified base
    61 names, so all of the above "constant" names would coincide.  Recall
    62 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
    63 diagnose syntax problems.
    64 
    65 * Type constructors admit general mixfix syntax, not just infix.
    66 
    67 * Concrete syntax may be attached to local entities without a proof
    68 body, too.  This works via regular mixfix annotations for 'fix',
    69 'def', 'obtain' etc. or via the explicit 'write' command, which is
    70 similar to the 'notation' command in theory specifications.
    71 
    72 * Use of cumulative prems via "!" in some proof methods has been
    73 discontinued (legacy feature).
    74 
    75 * References 'trace_simp' and 'debug_simp' have been replaced by
    76 configuration options stored in the context. Enabling tracing (the
    77 case of debugging is similar) in proofs works via
    78 
    79   using [[trace_simp = true]]
    80 
    81 Tracing is then active for all invocations of the simplifier in
    82 subsequent goal refinement steps. Tracing may also still be enabled or
    83 disabled via the ProofGeneral settings menu.
    84 
    85 * Separate commands 'hide_class', 'hide_type', 'hide_const',
    86 'hide_fact' replace the former 'hide' KIND command.  Minor
    87 INCOMPATIBILITY.
    88 
    89 
    90 *** Pure ***
    91 
    92 * Predicates of locales introduces by classes carry a mandatory
    93 "class" prefix.  INCOMPATIBILITY.
    94 
    95 * Command 'code_reflect' allows to incorporate generated ML code into
    96 runtime environment; replaces immature code_datatype antiquotation.
    97 INCOMPATIBILITY.
    98 
    99 * Empty class specifications observe default sort.  INCOMPATIBILITY.
   100 
   101 * Old 'axclass' command has been discontinued.  Use 'class' instead.
   102 INCOMPATIBILITY.
   103 
   104 * Code generator: simple concept for abstract datatypes obeying
   105 invariants.
   106 
   107 * Local theory specifications may depend on extra type variables that
   108 are not present in the result type -- arguments TYPE('a) :: 'a itself
   109 are added internally.  For example:
   110 
   111   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   112 
   113 * Code generator: details of internal data cache have no impact on the
   114 user space functionality any longer.
   115 
   116 * Methods unfold_locales and intro_locales ignore non-locale subgoals.
   117 This is more appropriate for interpretations with 'where'.
   118 INCOMPATIBILITY.
   119 
   120 * Discontinued unnamed infix syntax (legacy feature for many years) --
   121 need to specify constant name and syntax separately.  Internal ML
   122 datatype constructors have been renamed from InfixName to Infix etc.
   123 Minor INCOMPATIBILITY.
   124 
   125 * Command 'example_proof' opens an empty proof body.  This allows to
   126 experiment with Isar, without producing any persistent result.
   127 
   128 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   129 within a local theory context, with explicit checking of the
   130 constructors involved (in contrast to the raw 'syntax' versions).
   131 
   132 * Commands 'types' and 'typedecl' now work within a local theory
   133 context -- without introducing dependencies on parameters or
   134 assumptions, which is not possible in Isabelle/Pure.
   135 
   136 * Command 'defaultsort' has been renamed to 'default_sort', it works
   137 within a local theory context.  Minor INCOMPATIBILITY.
   138 
   139 * Proof terms: Type substitutions on proof constants now use canonical
   140 order of type variables. Potential INCOMPATIBILITY for tools working
   141 with proof terms.
   142 
   143 
   144 *** HOL ***
   145 
   146 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   147 longer shadowed.  INCOMPATIBILITY.
   148 
   149 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   150 INCOMPATIBILITY.
   151 
   152 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   153 INCOMPATIBILITY.
   154 
   155 * Dropped normalizing_semiring etc; use the facts in semiring classes
   156 instead.  INCOMPATIBILITY.
   157 
   158 * Theory 'Finite_Set': various folding_XXX locales facilitate the
   159 application of the various fold combinators on finite sets.
   160 
   161 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   162 provides abstract red-black tree type which is backed by "RBT_Impl" as
   163 implementation.  INCOMPATIBILTY.
   164 
   165 * Command 'typedef' now works within a local theory context -- without
   166 introducing dependencies on parameters or assumptions, which is not
   167 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   168 contain multiple interpretations of local typedefs (with different
   169 non-emptiness proofs), even in a global theory context.
   170 
   171 * Theory Library/Coinductive_List has been removed -- superseded by
   172 AFP/thys/Coinductive.
   173 
   174 * Theory PReal, including the type "preal" and related operations, has
   175 been removed.  INCOMPATIBILITY.
   176 
   177 * Split off theory Big_Operators containing setsum, setprod, Inf_fin,
   178 Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   179 
   180 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   181 "Int" etc.  INCOMPATIBILITY.
   182 
   183 * New set of rules "ac_simps" provides combined assoc / commute
   184 rewrites for all interpretations of the appropriate generic locales.
   185 
   186 * Renamed theory "OrderedGroup" to "Groups" and split theory
   187 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   188 appropriate and more consistent names suitable for name prefixes
   189 within the HOL theories.  INCOMPATIBILITY.
   190 
   191 * Some generic constants have been put to appropriate theories:
   192   - less_eq, less: Orderings
   193   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   194   - inverse, divide: Rings
   195 INCOMPATIBILITY.
   196 
   197 * More consistent naming of type classes involving orderings (and
   198 lattices):
   199 
   200     lower_semilattice                   ~> semilattice_inf
   201     upper_semilattice                   ~> semilattice_sup
   202 
   203     dense_linear_order                  ~> dense_linorder
   204 
   205     pordered_ab_group_add               ~> ordered_ab_group_add
   206     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   207     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   208     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   209     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   210     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   211     pordered_cancel_semiring            ~> ordered_cancel_semiring
   212     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   213     pordered_comm_ring                  ~> ordered_comm_ring
   214     pordered_comm_semiring              ~> ordered_comm_semiring
   215     pordered_ring                       ~> ordered_ring
   216     pordered_ring_abs                   ~> ordered_ring_abs
   217     pordered_semiring                   ~> ordered_semiring
   218 
   219     ordered_ab_group_add                ~> linordered_ab_group_add
   220     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   221     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   222     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   223     ordered_field                       ~> linordered_field
   224     ordered_field_no_lb                 ~> linordered_field_no_lb
   225     ordered_field_no_ub                 ~> linordered_field_no_ub
   226     ordered_field_dense_linear_order    ~> dense_linordered_field
   227     ordered_idom                        ~> linordered_idom
   228     ordered_ring                        ~> linordered_ring
   229     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   230     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   231     ordered_ring_strict                 ~> linordered_ring_strict
   232     ordered_semidom                     ~> linordered_semidom
   233     ordered_semiring                    ~> linordered_semiring
   234     ordered_semiring_1                  ~> linordered_semiring_1
   235     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   236     ordered_semiring_strict             ~> linordered_semiring_strict
   237 
   238   The following slightly odd type classes have been moved to a
   239   separate theory Library/Lattice_Algebras.thy:
   240 
   241     lordered_ab_group_add               ~> lattice_ab_group_add
   242     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   243     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   244     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   245     lordered_ring                       ~> lattice_ring
   246 
   247 INCOMPATIBILITY.
   248 
   249 * Refined field classes:
   250   - classes division_ring_inverse_zero, field_inverse_zero,
   251     linordered_field_inverse_zero include rule inverse 0 = 0 --
   252     subsumes former division_by_zero class;
   253   - numerous lemmas have been ported from field to division_ring.
   254 INCOMPATIBILITY.
   255 
   256 * Refined algebra theorem collections:
   257   - dropped theorem group group_simps, use algebra_simps instead;
   258   - dropped theorem group ring_simps, use field_simps instead;
   259   - proper theorem collection field_simps subsumes former theorem
   260     groups field_eq_simps and field_simps;
   261   - dropped lemma eq_minus_self_iff which is a duplicate for
   262     equal_neg_zero.
   263 INCOMPATIBILITY.
   264 
   265 * Theory Finite_Set and List: some lemmas have been generalized from
   266 sets to lattices:
   267 
   268   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   269   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   270   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   271   union_Union_fold_union        ~> sup_Sup_fold_sup
   272   Inter_fold_inter              ~> Inf_fold_inf
   273   Union_fold_union              ~> Sup_fold_sup
   274   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   275   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   276   INTER_fold_inter              ~> INFI_fold_inf
   277   UNION_fold_union              ~> SUPR_fold_sup
   278 
   279 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   280 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   281 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   282 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   283 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   284 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   285 
   286 * HOLogic.strip_psplit: types are returned in syntactic order, similar
   287 to other strip and tuple operations.  INCOMPATIBILITY.
   288 
   289 * Reorganized theory Multiset: swapped notation of pointwise and
   290 multiset order:
   291   - pointwise ordering is instance of class order with standard syntax
   292     <= and <;
   293   - multiset ordering has syntax <=# and <#; partial order properties
   294     are provided by means of interpretation with prefix
   295     multiset_order;
   296   - less duplication, less historical organization of sections,
   297     conversion from associations lists to multisets, rudimentary code
   298     generation;
   299   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   300     if needed.
   301 Renamed:
   302   multiset_eq_conv_count_eq -> multiset_ext_iff
   303   multi_count_ext -> multiset_ext
   304   diff_union_inverse2 -> diff_union_cancelR
   305 INCOMPATIBILITY.
   306 
   307 * Theory Permutation: replaced local "remove" by List.remove1.
   308 
   309 * Code generation: ML and OCaml code is decorated with signatures.
   310 
   311 * Theory List: added transpose.
   312 
   313 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   314 clash with new theory Quotient in Main HOL.
   315 
   316 * Library/Nat_Bijection.thy is a collection of bijective functions
   317 between nat and other types, which supersedes the older libraries
   318 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   319 
   320   Constants:
   321   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   322   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   323   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   324   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   325   Countable.pair_encode           ~> prod_encode
   326   NatIso.prod2nat                 ~> prod_encode
   327   NatIso.nat2prod                 ~> prod_decode
   328   NatIso.sum2nat                  ~> sum_encode
   329   NatIso.nat2sum                  ~> sum_decode
   330   NatIso.list2nat                 ~> list_encode
   331   NatIso.nat2list                 ~> list_decode
   332   NatIso.set2nat                  ~> set_encode
   333   NatIso.nat2set                  ~> set_decode
   334 
   335   Lemmas:
   336   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   337   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   338   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   339   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   340   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   341   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   342   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   343   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   344   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   345   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   346   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   347   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   348   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   349 
   350 
   351 *** HOLCF ***
   352 
   353 * Variable names in lemmas generated by the domain package have
   354 changed; the naming scheme is now consistent with the HOL datatype
   355 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   356 
   357 * The domain package no longer defines the function "foo_copy" for
   358 recursive domain "foo".  The reach lemma is now stated directly in
   359 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   360 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   361 
   362 * Most definedness lemmas generated by the domain package (previously
   363 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   364 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   365 Proof scripts that used definedness lemmas as intro rules may break,
   366 potential INCOMPATIBILITY.
   367 
   368 * Induction and casedist rules generated by the domain package now
   369 declare proper case_names (one called "bottom", and one named for each
   370 constructor).  INCOMPATIBILITY.
   371 
   372 * For mutually-recursive domains, separate "reach" and "take_lemma"
   373 rules are generated for each domain, INCOMPATIBILITY.
   374 
   375   foo_bar.reach       ~> foo.reach  bar.reach
   376   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   377 
   378 * Some lemmas generated by the domain package have been renamed for
   379 consistency with the datatype package, INCOMPATIBILITY.
   380 
   381   foo.ind        ~> foo.induct
   382   foo.finite_ind ~> foo.finite_induct
   383   foo.coind      ~> foo.coinduct
   384   foo.casedist   ~> foo.exhaust
   385   foo.exhaust    ~> foo.nchotomy
   386 
   387 * For consistency with other definition packages, the fixrec package
   388 now generates qualified theorem names, INCOMPATIBILITY.
   389 
   390   foo_simps  ~> foo.simps
   391   foo_unfold ~> foo.unfold
   392   foo_induct ~> foo.induct
   393 
   394 * The "contlub" predicate has been removed.  Proof scripts should use
   395 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   396 
   397 * The "admw" predicate has been removed, INCOMPATIBILITY.
   398 
   399 * The constants cpair, cfst, and csnd have been removed in favor of
   400 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   401 
   402 
   403 *** ML ***
   404 
   405 * Sorts.certify_sort and derived "cert" operations for types and terms
   406 no longer minimize sorts.  Thus certification at the boundary of the
   407 inference kernel becomes invariant under addition of class relations,
   408 which is an important monotonicity principle.  Sorts are now minimized
   409 in the syntax layer only, at the boundary between the end-user and the
   410 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   411 explicitly in rare situations.
   412 
   413 * Antiquotations for basic formal entities:
   414 
   415     @{class NAME}         -- type class
   416     @{class_syntax NAME}  -- syntax representation of the above
   417 
   418     @{type_name NAME}     -- logical type
   419     @{type_abbrev NAME}   -- type abbreviation
   420     @{nonterminal NAME}   -- type of concrete syntactic category
   421     @{type_syntax NAME}   -- syntax representation of any of the above
   422 
   423     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   424     @{const_abbrev NAME}  -- abbreviated constant
   425     @{const_syntax NAME}  -- syntax representation of any of the above
   426 
   427 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   428 syntax constant (cf. 'syntax' command).
   429 
   430 * Antiquotation @{make_string} inlines a function to print arbitrary
   431 values similar to the ML toplevel.  The result is compiler dependent
   432 and may fall back on "?" in certain situations.
   433 
   434 * Renamed old-style Drule.standard to Drule.export_without_context, to
   435 emphasize that this is in no way a standard operation.
   436 INCOMPATIBILITY.
   437 
   438 * Curried take and drop in library.ML; negative length is interpreted
   439 as infinity (as in chop).  INCOMPATIBILITY.
   440 
   441 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   442 usual for resolution.  Rare INCOMPATIBILITY.
   443 
   444 * Discontinued old TheoryDataFun with its copy/init operation -- data
   445 needs to be pure.  Functor Theory_Data_PP retains the traditional
   446 Pretty.pp argument to merge, which is absent in the standard
   447 Theory_Data version.
   448 
   449 * Renamed varify/unvarify operations to varify_global/unvarify_global
   450 to emphasize that these only work in a global situation (which is
   451 quite rare).
   452 
   453 * Configuration options now admit dynamic default values, depending on
   454 the context or even global references.
   455 
   456 * Most operations that refer to a global context are named
   457 accordingly, e.g. Simplifier.global_context or
   458 ProofContext.init_global.  There are some situations where a global
   459 context actually works, but under normal circumstances one needs to
   460 pass the proper local context through the code!
   461 
   462 
   463 *** System ***
   464 
   465 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   466 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   467 proof terms are enabled unconditionally in the new HOL-Proofs image.
   468 
   469 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   470 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   471 respectively.
   472 
   473 * Old lib/scripts/polyml-platform is superseded by the
   474 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   475 variant, even on a 64 bit machine.  The following example setting
   476 prefers 64 bit if available:
   477 
   478   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   479 
   480 
   481 
   482 New in Isabelle2009-1 (December 2009)
   483 -------------------------------------
   484 
   485 *** General ***
   486 
   487 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   488 one backslash should be used, even in ML sources.
   489 
   490 
   491 *** Pure ***
   492 
   493 * Locale interpretation propagates mixins along the locale hierarchy.
   494 The currently only available mixins are the equations used to map
   495 local definitions to terms of the target domain of an interpretation.
   496 
   497 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   498 loc" to print all interpretations of locale "loc" in the theory.
   499 Interpretations in proofs are not shown.
   500 
   501 * Thoroughly revised locales tutorial.  New section on conditional
   502 interpretation.
   503 
   504 * On instantiation of classes, remaining undefined class parameters
   505 are formally declared.  INCOMPATIBILITY.
   506 
   507 
   508 *** Document preparation ***
   509 
   510 * New generalized style concept for printing terms: @{foo (style) ...}
   511 instead of @{foo_style style ...}  (old form is still retained for
   512 backward compatibility).  Styles can be also applied for
   513 antiquotations prop, term_type and typeof.
   514 
   515 
   516 *** HOL ***
   517 
   518 * New proof method "smt" for a combination of first-order logic with
   519 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   520 fixed-size bitvectors; there is also basic support for higher-order
   521 features (esp. lambda abstractions).  It is an incomplete decision
   522 procedure based on external SMT solvers using the oracle mechanism;
   523 for the SMT solver Z3, this method is proof-producing.  Certificates
   524 are provided to avoid calling the external solvers solely for
   525 re-checking proofs.  Due to a remote SMT service there is no need for
   526 installing SMT solvers locally.  See src/HOL/SMT.
   527 
   528 * New commands to load and prove verification conditions generated by
   529 the Boogie program verifier or derived systems (e.g. the Verifying C
   530 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   531 
   532 * New counterexample generator tool 'nitpick' based on the Kodkod
   533 relational model finder.  See src/HOL/Tools/Nitpick and
   534 src/HOL/Nitpick_Examples.
   535 
   536 * New commands 'code_pred' and 'values' to invoke the predicate
   537 compiler and to enumerate values of inductive predicates.
   538 
   539 * A tabled implementation of the reflexive transitive closure.
   540 
   541 * New implementation of quickcheck uses generic code generator;
   542 default generators are provided for all suitable HOL types, records
   543 and datatypes.  Old quickcheck can be re-activated importing theory
   544 Library/SML_Quickcheck.
   545 
   546 * New testing tool Mirabelle for automated proof tools.  Applies
   547 several tools and tactics like sledgehammer, metis, or quickcheck, to
   548 every proof step in a theory.  To be used in batch mode via the
   549 "mirabelle" utility.
   550 
   551 * New proof method "sos" (sum of squares) for nonlinear real
   552 arithmetic (originally due to John Harison). It requires theory
   553 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   554 works well in practice on quantifier-free real arithmetic with +, -,
   555 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   556 inequalities between polynomials.  It makes use of external
   557 semidefinite programming solvers.  Method "sos" generates a
   558 certificate that can be pasted into the proof thus avoiding the need
   559 to call an external tool every time the proof is checked.  See
   560 src/HOL/Library/Sum_Of_Squares.
   561 
   562 * New method "linarith" invokes existing linear arithmetic decision
   563 procedure only.
   564 
   565 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   566 
   567 * New Sledgehammer option "Full Types" in Proof General settings menu.
   568 Causes full type information to be output to the ATPs.  This slows
   569 ATPs down considerably but eliminates a source of unsound "proofs"
   570 that fail later.
   571 
   572 * New method "metisFT": A version of metis that uses full type
   573 information in order to avoid failures of proof reconstruction.
   574 
   575 * New evaluator "approximate" approximates an real valued term using
   576 the same method as the approximation method.
   577 
   578 * Method "approximate" now supports arithmetic expressions as
   579 boundaries of intervals and implements interval splitting and Taylor
   580 series expansion.
   581 
   582 * ML antiquotation @{code_datatype} inserts definition of a datatype
   583 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   584 
   585 * New theory SupInf of the supremum and infimum operators for sets of
   586 reals.
   587 
   588 * New theory Probability, which contains a development of measure
   589 theory, eventually leading to Lebesgue integration and probability.
   590 
   591 * Extended Multivariate Analysis to include derivation and Brouwer's
   592 fixpoint theorem.
   593 
   594 * Reorganization of number theory, INCOMPATIBILITY:
   595   - new number theory development for nat and int, in theories Divides
   596     and GCD as well as in new session Number_Theory
   597   - some constants and facts now suffixed with _nat and _int
   598     accordingly
   599   - former session NumberTheory now named Old_Number_Theory, including
   600     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   601   - moved theory Pocklington from src/HOL/Library to
   602     src/HOL/Old_Number_Theory
   603 
   604 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   605 lcm of finite and infinite sets. It is shown that they form a complete
   606 lattice.
   607 
   608 * Class semiring_div requires superclass no_zero_divisors and proof of
   609 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   610 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   611 generalized to class semiring_div, subsuming former theorems
   612 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   613 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   614 INCOMPATIBILITY.
   615 
   616 * Refinements to lattice classes and sets:
   617   - less default intro/elim rules in locale variant, more default
   618     intro/elim rules in class variant: more uniformity
   619   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   620     le_inf_iff
   621   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   622     sup_aci)
   623   - renamed ACI to inf_sup_aci
   624   - new class "boolean_algebra"
   625   - class "complete_lattice" moved to separate theory
   626     "Complete_Lattice"; corresponding constants (and abbreviations)
   627     renamed and with authentic syntax:
   628     Set.Inf ~>    Complete_Lattice.Inf
   629     Set.Sup ~>    Complete_Lattice.Sup
   630     Set.INFI ~>   Complete_Lattice.INFI
   631     Set.SUPR ~>   Complete_Lattice.SUPR
   632     Set.Inter ~>  Complete_Lattice.Inter
   633     Set.Union ~>  Complete_Lattice.Union
   634     Set.INTER ~>  Complete_Lattice.INTER
   635     Set.UNION ~>  Complete_Lattice.UNION
   636   - authentic syntax for
   637     Set.Pow
   638     Set.image
   639   - mere abbreviations:
   640     Set.empty               (for bot)
   641     Set.UNIV                (for top)
   642     Set.inter               (for inf, formerly Set.Int)
   643     Set.union               (for sup, formerly Set.Un)
   644     Complete_Lattice.Inter  (for Inf)
   645     Complete_Lattice.Union  (for Sup)
   646     Complete_Lattice.INTER  (for INFI)
   647     Complete_Lattice.UNION  (for SUPR)
   648   - object-logic definitions as far as appropriate
   649 
   650 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   651 Un_subset_iff are explicitly deleted as default simp rules; then also
   652 their lattice counterparts le_inf_iff and le_sup_iff have to be
   653 deleted to achieve the desired effect.
   654 
   655 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   656 rules by default any longer; the same applies to min_max.inf_absorb1
   657 etc.  INCOMPATIBILITY.
   658 
   659 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   660 pred_set_conv by default.  INCOMPATIBILITY.
   661 
   662 * Power operations on relations and functions are now one dedicated
   663 constant "compow" with infix syntax "^^".  Power operation on
   664 multiplicative monoids retains syntax "^" and is now defined generic
   665 in class power.  INCOMPATIBILITY.
   666 
   667 * Relation composition "R O S" now has a more standard argument order:
   668 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   669 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   670 break, since the O_assoc rule was not rewritten like this.  Fix using
   671 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   672 
   673 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   674 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   675 INCOMPATIBILITY.
   676 
   677 * Most rules produced by inductive and datatype package have mandatory
   678 prefixes.  INCOMPATIBILITY.
   679 
   680 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   681 the attribute of the same name.  Each of the theorems in the list
   682 DERIV_intros assumes composition with an additional function and
   683 matches a variable to the derivative, which has to be solved by the
   684 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   685 of most elementary terms.  Former Maclauren.DERIV_tac and
   686 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   687 INCOMPATIBILITY.
   688 
   689 * Code generator attributes follow the usual underscore convention:
   690     code_unfold     replaces    code unfold
   691     code_post       replaces    code post
   692     etc.
   693   INCOMPATIBILITY.
   694 
   695 * Renamed methods:
   696     sizechange -> size_change
   697     induct_scheme -> induction_schema
   698   INCOMPATIBILITY.
   699 
   700 * Discontinued abbreviation "arbitrary" of constant "undefined".
   701 INCOMPATIBILITY, use "undefined" directly.
   702 
   703 * Renamed theorems:
   704     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   705     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   706     Suc_plus1 -> Suc_eq_plus1
   707     *anti_sym -> *antisym*
   708     vector_less_eq_def -> vector_le_def
   709   INCOMPATIBILITY.
   710 
   711 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   712 INCOMPATIBILITY.
   713 
   714 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   715 INCOMPATIBILITY.
   716 
   717 
   718 *** HOLCF ***
   719 
   720 * Theory Representable defines a class "rep" of domains that are
   721 representable (via an ep-pair) in the universal domain type "udom".
   722 Instances are provided for all type constructors defined in HOLCF.
   723 
   724 * The 'new_domain' command is a purely definitional version of the
   725 domain package, for representable domains.  Syntax is identical to the
   726 old domain package.  The 'new_domain' package also supports indirect
   727 recursion using previously-defined type constructors.  See
   728 src/HOLCF/ex/New_Domain.thy for examples.
   729 
   730 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   731 on the left-hand side of an equation, and then performs
   732 simplification.  Rewriting is done using rules declared with the
   733 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   734 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   735 
   736 * The pattern-match compiler in 'fixrec' can now handle constructors
   737 with HOL function types.  Pattern-match combinators for the Pair
   738 constructor are pre-configured.
   739 
   740 * The 'fixrec' package now produces better fixed-point induction rules
   741 for mutually-recursive definitions:  Induction rules have conclusions
   742 of the form "P foo bar" instead of "P <foo, bar>".
   743 
   744 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   745 been renamed to "below".  The name "below" now replaces "less" in many
   746 theorem names.  (Legacy theorem names using "less" are still supported
   747 as well.)
   748 
   749 * The 'fixrec' package now supports "bottom patterns".  Bottom
   750 patterns can be used to generate strictness rules, or to make
   751 functions more strict (much like the bang-patterns supported by the
   752 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   753 examples.
   754 
   755 
   756 *** ML ***
   757 
   758 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   759 errors and run-time exceptions, including detailed source positions.
   760 
   761 * Structure Name_Space (formerly NameSpace) now manages uniquely
   762 identified entries, with some additional information such as source
   763 position, logical grouping etc.
   764 
   765 * Theory and context data is now introduced by the simplified and
   766 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   767 to be pure, but the old TheoryDataFun for mutable data (with explicit
   768 copy operation) is still available for some time.
   769 
   770 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   771 provides a high-level programming interface to synchronized state
   772 variables with atomic update.  This works via pure function
   773 application within a critical section -- its runtime should be as
   774 short as possible; beware of deadlocks if critical code is nested,
   775 either directly or indirectly via other synchronized variables!
   776 
   777 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   778 wraps raw ML references, explicitly indicating their non-thread-safe
   779 behaviour.  The Isar toplevel keeps this structure open, to
   780 accommodate Proof General as well as quick and dirty interactive
   781 experiments with references.
   782 
   783 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   784 parallel tactical reasoning.
   785 
   786 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   787 are similar to SUBPROOF, but are slightly more flexible: only the
   788 specified parts of the subgoal are imported into the context, and the
   789 body tactic may introduce new subgoals and schematic variables.
   790 
   791 * Old tactical METAHYPS, which does not observe the proof context, has
   792 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   793 or Subgoal.FOCUS etc.
   794 
   795 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   796 functors have their own ML name space there is no point to mark them
   797 separately.)  Minor INCOMPATIBILITY.
   798 
   799 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   800 
   801 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   802 INCOMPATIBILITY.
   803 
   804 * Operations of structure Skip_Proof no longer require quick_and_dirty
   805 mode, which avoids critical setmp.
   806 
   807 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   808 combinators for "args".  INCOMPATIBILITY, need to use simplified
   809 Attrib/Method.setup introduced in Isabelle2009.
   810 
   811 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   812 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   813 last resort.  INCOMPATIBILITY.
   814 
   815 * Display.pretty_thm now requires a proper context (cf. former
   816 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   817 or even Display.pretty_thm_without_context as last resort.
   818 INCOMPATIBILITY.
   819 
   820 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   821 Syntax.pretty_typ/term directly, preferably with proper context
   822 instead of global theory.
   823 
   824 
   825 *** System ***
   826 
   827 * Further fine tuning of parallel proof checking, scales up to 8 cores
   828 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   829 usedir option -q.
   830 
   831 * Support for additional "Isabelle components" via etc/components, see
   832 also the system manual.
   833 
   834 * The isabelle makeall tool now operates on all components with
   835 IsaMakefile, not just hardwired "logics".
   836 
   837 * Removed "compress" option from isabelle-process and isabelle usedir;
   838 this is always enabled.
   839 
   840 * Discontinued support for Poly/ML 4.x versions.
   841 
   842 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   843 on a given logic image.  This requires the lighttpd webserver and is
   844 currently supported on Linux only.
   845 
   846 
   847 
   848 New in Isabelle2009 (April 2009)
   849 --------------------------------
   850 
   851 *** General ***
   852 
   853 * Simplified main Isabelle executables, with less surprises on
   854 case-insensitive file-systems (such as Mac OS).
   855 
   856   - The main Isabelle tool wrapper is now called "isabelle" instead of
   857     "isatool."
   858 
   859   - The former "isabelle" alias for "isabelle-process" has been
   860     removed (should rarely occur to regular users).
   861 
   862   - The former "isabelle-interface" and its alias "Isabelle" have been
   863     removed (interfaces are now regular Isabelle tools).
   864 
   865 Within scripts and make files, the Isabelle environment variables
   866 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   867 respectively.  (The latter are still available as legacy feature.)
   868 
   869 The old isabelle-interface wrapper could react in confusing ways if
   870 the interface was uninstalled or changed otherwise.  Individual
   871 interface tool configuration is now more explicit, see also the
   872 Isabelle system manual.  In particular, Proof General is now available
   873 via "isabelle emacs".
   874 
   875 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   876 purge installed copies of Isabelle executables and re-run "isabelle
   877 install -p ...", or use symlinks.
   878 
   879 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   880 old ~/isabelle, which was slightly non-standard and apt to cause
   881 surprises on case-insensitive file-systems (such as Mac OS).
   882 
   883 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   884 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   885 care is required when using older releases of Isabelle.  Note that
   886 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   887 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   888 
   889 * Proofs of fully specified statements are run in parallel on
   890 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   891 a regular 4-core machine, if the initial heap space is made reasonably
   892 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   893 
   894 * The main reference manuals ("isar-ref", "implementation", and
   895 "system") have been updated and extended.  Formally checked references
   896 as hyperlinks are now available uniformly.
   897 
   898 
   899 *** Pure ***
   900 
   901 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   902 respects.  The most important changes are listed below.  See the
   903 Tutorial on Locales ("locales" manual) for details.
   904 
   905 - In locale expressions, instantiation replaces renaming.  Parameters
   906 must be declared in a for clause.  To aid compatibility with previous
   907 parameter inheritance, in locale declarations, parameters that are not
   908 'touched' (instantiation position "_" or omitted) are implicitly added
   909 with their syntax at the beginning of the for clause.
   910 
   911 - Syntax from abbreviations and definitions in locales is available in
   912 locale expressions and context elements.  The latter is particularly
   913 useful in locale declarations.
   914 
   915 - More flexible mechanisms to qualify names generated by locale
   916 expressions.  Qualifiers (prefixes) may be specified in locale
   917 expressions, and can be marked as mandatory (syntax: "name!:") or
   918 optional (syntax "name?:").  The default depends for plain "name:"
   919 depends on the situation where a locale expression is used: in
   920 commands 'locale' and 'sublocale' prefixes are optional, in
   921 'interpretation' and 'interpret' prefixes are mandatory.  The old
   922 implicit qualifiers derived from the parameter names of a locale are
   923 no longer generated.
   924 
   925 - Command "sublocale l < e" replaces "interpretation l < e".  The
   926 instantiation clause in "interpretation" and "interpret" (square
   927 brackets) is no longer available.  Use locale expressions.
   928 
   929 - When converting proof scripts, mandatory qualifiers in
   930 'interpretation' and 'interpret' should be retained by default, even
   931 if this is an INCOMPATIBILITY compared to former behavior.  In the
   932 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   933 in locale expressions range over a single locale instance only.
   934 
   935 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   936 In existing theorem specifications replace the includes element by the
   937 respective context elements of the included locale, omitting those
   938 that are already present in the theorem specification.  Multiple
   939 assume elements of a locale should be replaced by a single one
   940 involving the locale predicate.  In the proof body, declarations (most
   941 notably theorems) may be regained by interpreting the respective
   942 locales in the proof context as required (command "interpret").
   943 
   944 If using "includes" in replacement of a target solely because the
   945 parameter types in the theorem are not as general as in the target,
   946 consider declaring a new locale with additional type constraints on
   947 the parameters (context element "constrains").
   948 
   949 - Discontinued "locale (open)".  INCOMPATIBILITY.
   950 
   951 - Locale interpretation commands no longer attempt to simplify goal.
   952 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   953 methods intro_locales and unfold_locales to clarify.
   954 
   955 - Locale interpretation commands no longer accept interpretation
   956 attributes.  INCOMPATIBILITY.
   957 
   958 * Class declaration: so-called "base sort" must not be given in import
   959 list any longer, but is inferred from the specification.  Particularly
   960 in HOL, write
   961 
   962     class foo = ...
   963 
   964 instead of
   965 
   966     class foo = type + ...
   967 
   968 * Class target: global versions of theorems stemming do not carry a
   969 parameter prefix any longer.  INCOMPATIBILITY.
   970 
   971 * Class 'instance' command no longer accepts attached definitions.
   972 INCOMPATIBILITY, use proper 'instantiation' target instead.
   973 
   974 * Recovered hiding of consts, which was accidentally broken in
   975 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   976 makes c inaccessible; consider using ``hide (open) const c'' instead.
   977 
   978 * Slightly more coherent Pure syntax, with updated documentation in
   979 isar-ref manual.  Removed locales meta_term_syntax and
   980 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   981 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   982 directly in regular applications.
   983 
   984 * There is a new syntactic category "float_const" for signed decimal
   985 fractions (e.g. 123.45 or -123.45).
   986 
   987 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   988 interface with 'setup' command instead.
   989 
   990 * Command 'local_setup' is similar to 'setup', but operates on a local
   991 theory context.
   992 
   993 * The 'axiomatization' command now only works within a global theory
   994 context.  INCOMPATIBILITY.
   995 
   996 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   997 hypotheses.  Sorts required in the course of reasoning need to be
   998 covered by the constraints in the initial statement, completed by the
   999 type instance information of the background theory.  Non-trivial sort
  1000 hypotheses, which rarely occur in practice, may be specified via
  1001 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1002 
  1003   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1004 
  1005 The result contains an implicit sort hypotheses as before --
  1006 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1007 normalization.
  1008 
  1009 * Generalized Isar history, with support for linear undo, direct state
  1010 addressing etc.
  1011 
  1012 * Changed defaults for unify configuration options:
  1013 
  1014   unify_trace_bound = 50 (formerly 25)
  1015   unify_search_bound = 60 (formerly 30)
  1016 
  1017 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1018 
  1019   a) On theory merge, the last set of code equations for a particular
  1020      constant is taken (in accordance with the policy applied by other
  1021      parts of the code generator framework).
  1022 
  1023   b) Code equations stemming from explicit declarations (e.g. code
  1024      attribute) gain priority over default code equations stemming
  1025      from definition, primrec, fun etc.
  1026 
  1027 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1028 
  1029 * Unified theorem tables for both code generators.  Thus [code
  1030 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1031 
  1032 * Command 'find_consts' searches for constants based on type and name
  1033 patterns, e.g.
  1034 
  1035     find_consts "_ => bool"
  1036 
  1037 By default, matching is against subtypes, but it may be restricted to
  1038 the whole type.  Searching by name is possible.  Multiple queries are
  1039 conjunctive and queries may be negated by prefixing them with a
  1040 hyphen:
  1041 
  1042     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1043 
  1044 * New 'find_theorems' criterion "solves" matches theorems that
  1045 directly solve the current goal (modulo higher-order unification).
  1046 
  1047 * Auto solve feature for main theorem statements: whenever a new goal
  1048 is stated, "find_theorems solves" is called; any theorems that could
  1049 solve the lemma directly are listed as part of the goal state.
  1050 Cf. associated options in Proof General Isabelle settings menu,
  1051 enabled by default, with reasonable timeout for pathological cases of
  1052 higher-order unification.
  1053 
  1054 
  1055 *** Document preparation ***
  1056 
  1057 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1058 demanding keyword 'by' and supporting the full method expression
  1059 syntax just like the Isar command 'by'.
  1060 
  1061 
  1062 *** HOL ***
  1063 
  1064 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1065 points Main and Complex_Main remain as before.
  1066 
  1067 * Logic image HOL-Plain provides a minimal HOL with the most important
  1068 tools available (inductive, datatype, primrec, ...).  This facilitates
  1069 experimentation and tool development.  Note that user applications
  1070 (and library theories) should never refer to anything below theory
  1071 Main, as before.
  1072 
  1073 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1074 experimentation due to shorter build times.
  1075 
  1076 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1077 were previously part of former HOL-Complex.  Entry point Hyperreal
  1078 remains valid, but theories formerly using Complex_Main should now use
  1079 new entry point Hypercomplex.
  1080 
  1081 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1082 Posix processes.  Avoids potentially expensive forking of the ML
  1083 process.  New thread-based implementation also works on non-Unix
  1084 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1085 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1086 commands are covered in the isar-ref manual.
  1087 
  1088 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1089 sledgehammer without local ATP installation (Vampire etc.). Other
  1090 provers may be included via suitable ML wrappers, see also
  1091 src/HOL/ATP_Linkup.thy.
  1092 
  1093 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1094 menu.
  1095 
  1096 * The metis method no longer fails because the theorem is too trivial
  1097 (contains the empty clause).
  1098 
  1099 * The metis method now fails in the usual manner, rather than raising
  1100 an exception, if it determines that it cannot prove the theorem.
  1101 
  1102 * Method "coherent" implements a prover for coherent logic (see also
  1103 src/Tools/coherent.ML).
  1104 
  1105 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1106 "undefined" is the right choice to replace "arbitrary", though
  1107 logically there is no difference.  INCOMPATIBILITY.
  1108 
  1109 * Command "value" now integrates different evaluation mechanisms.  The
  1110 result of the first successful evaluation mechanism is printed.  In
  1111 square brackets a particular named evaluation mechanisms may be
  1112 specified (currently, [SML], [code] or [nbe]).  See further
  1113 src/HOL/ex/Eval_Examples.thy.
  1114 
  1115 * Normalization by evaluation now allows non-leftlinear equations.
  1116 Declare with attribute [code nbe].
  1117 
  1118 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1119 as the structured Isar versions "cases" and "induct", cf. the
  1120 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1121 are now presented as a list of individual projections
  1122 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1123 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1124 rare situations a different rule is selected --- notably nested tuple
  1125 elimination instead of former prod.exhaust: use explicit (case_tac t
  1126 rule: prod.exhaust) here.
  1127 
  1128 * Attributes "cases", "induct", "coinduct" support "del" option.
  1129 
  1130 * Removed fact "case_split_thm", which duplicates "case_split".
  1131 
  1132 * The option datatype has been moved to a new theory Option.  Renamed
  1133 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1134 
  1135 * New predicate "strict_mono" classifies strict functions on partial
  1136 orders.  With strict functions on linear orders, reasoning about
  1137 (in)equalities is facilitated by theorems "strict_mono_eq",
  1138 "strict_mono_less_eq" and "strict_mono_less".
  1139 
  1140 * Some set operations are now proper qualified constants with
  1141 authentic syntax.  INCOMPATIBILITY:
  1142 
  1143     op Int ~>   Set.Int
  1144     op Un ~>    Set.Un
  1145     INTER ~>    Set.INTER
  1146     UNION ~>    Set.UNION
  1147     Inter ~>    Set.Inter
  1148     Union ~>    Set.Union
  1149     {} ~>       Set.empty
  1150     UNIV ~>     Set.UNIV
  1151 
  1152 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1153 theory Set.
  1154 
  1155 * Auxiliary class "itself" has disappeared -- classes without any
  1156 parameter are treated as expected by the 'class' command.
  1157 
  1158 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1159 
  1160 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1161 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1162 
  1163 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1164 method "approximation".  It proves formulas on real values by using
  1165 interval arithmetic.  In the formulas are also the transcendental
  1166 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1167 allowed. For examples see
  1168 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1169 
  1170 * Theory "Reflection" now resides in HOL/Library.
  1171 
  1172 * Entry point to Word library now simply named "Word".
  1173 INCOMPATIBILITY.
  1174 
  1175 * Made source layout more coherent with logical distribution
  1176 structure:
  1177 
  1178     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1179     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1180     src/HOL/Library/GCD.thy ~> src/HOL/
  1181     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1182     src/HOL/Library/Parity.thy ~> src/HOL/
  1183     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1184     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1185     src/HOL/Real/Lubs.thy ~> src/HOL/
  1186     src/HOL/Real/PReal.thy ~> src/HOL/
  1187     src/HOL/Real/Rational.thy ~> src/HOL/
  1188     src/HOL/Real/RComplete.thy ~> src/HOL/
  1189     src/HOL/Real/RealDef.thy ~> src/HOL/
  1190     src/HOL/Real/RealPow.thy ~> src/HOL/
  1191     src/HOL/Real/Real.thy ~> src/HOL/
  1192     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1193     src/HOL/Complex/Complex.thy ~> src/HOL/
  1194     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1195     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1196     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1197     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1198     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1199     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1200     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1201     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1202     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1203     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1204     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1205     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1206     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1207     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1208     src/HOL/Real/Float ~> src/HOL/Library/
  1209     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1210     src/HOL/Real/RealVector.thy ~> src/HOL/
  1211 
  1212     src/HOL/arith_data.ML ~> src/HOL/Tools
  1213     src/HOL/hologic.ML ~> src/HOL/Tools
  1214     src/HOL/simpdata.ML ~> src/HOL/Tools
  1215     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1216     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1217     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1218     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1219     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1220     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1221     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1222 
  1223     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1224     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1225     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1226     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1227     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1228     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1229 
  1230 * If methods "eval" and "evaluation" encounter a structured proof
  1231 state with !!/==>, only the conclusion is evaluated to True (if
  1232 possible), avoiding strange error messages.
  1233 
  1234 * Method "sizechange" automates termination proofs using (a
  1235 modification of) the size-change principle.  Requires SAT solver.  See
  1236 src/HOL/ex/Termination.thy for examples.
  1237 
  1238 * Simplifier: simproc for let expressions now unfolds if bound
  1239 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1240 
  1241 * Method "arith": Linear arithmetic now ignores all inequalities when
  1242 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1243 
  1244 * New attribute "arith" for facts that should always be used
  1245 automatically by arithmetic. It is intended to be used locally in
  1246 proofs, e.g.
  1247 
  1248   assumes [arith]: "x > 0"
  1249 
  1250 Global usage is discouraged because of possible performance impact.
  1251 
  1252 * New classes "top" and "bot" with corresponding operations "top" and
  1253 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1254 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1255 
  1256 * Changed definition lemma "less_fun_def" in order to provide an
  1257 instance for preorders on functions; use lemma "less_le" instead.
  1258 INCOMPATIBILITY.
  1259 
  1260 * Theory Orderings: class "wellorder" moved here, with explicit
  1261 induction rule "less_induct" as assumption.  For instantiation of
  1262 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1263 INCOMPATIBILITY.
  1264 
  1265 * Theory Orderings: added class "preorder" as superclass of "order".
  1266 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1267 etc. slightly changed.  Some theorems named order_class.* now named
  1268 preorder_class.*.
  1269 
  1270 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1271 "diag" to "Id_on".
  1272 
  1273 * Theory Finite_Set: added a new fold combinator of type
  1274 
  1275   ('a => 'b => 'b) => 'b => 'a set => 'b
  1276 
  1277 Occasionally this is more convenient than the old fold combinator
  1278 which is now defined in terms of the new one and renamed to
  1279 fold_image.
  1280 
  1281 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1282 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1283 extended with further lemmas!).  At the moment both still exist but
  1284 the former will disappear at some point.
  1285 
  1286 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1287 class recpower.  Type-specific simp rules for various recpower types
  1288 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1289 
  1290 rat_power_0    -> power_0
  1291 rat_power_Suc  -> power_Suc
  1292 realpow_0      -> power_0
  1293 realpow_Suc    -> power_Suc
  1294 complexpow_0   -> power_0
  1295 complexpow_Suc -> power_Suc
  1296 power_poly_0   -> power_0
  1297 power_poly_Suc -> power_Suc
  1298 
  1299 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1300 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1301 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1302 of lemmas from Divides has been generalized from nat to class
  1303 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1304 renames resulting from duplicate elimination:
  1305 
  1306     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1307     zero_dvd_iff ~>         dvd_0_left_iff
  1308     dvd_0 ~>                dvd_0_right
  1309     DIVISION_BY_ZERO_DIV ~> div_by_0
  1310     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1311     mult_div ~>             div_mult_self2_is_id
  1312     mult_mod ~>             mod_mult_self2_is_0
  1313 
  1314 * Theory IntDiv: removed many lemmas that are instances of class-based
  1315 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1316 rename old lemmas as follows:
  1317 
  1318 dvd_diff               -> nat_dvd_diff
  1319 dvd_zminus_iff         -> dvd_minus_iff
  1320 mod_add1_eq            -> mod_add_eq
  1321 mod_mult1_eq           -> mod_mult_right_eq
  1322 mod_mult1_eq'          -> mod_mult_left_eq
  1323 mod_mult_distrib_mod   -> mod_mult_eq
  1324 nat_mod_add_left_eq    -> mod_add_left_eq
  1325 nat_mod_add_right_eq   -> mod_add_right_eq
  1326 nat_mod_div_trivial    -> mod_div_trivial
  1327 nat_mod_mod_trivial    -> mod_mod_trivial
  1328 zdiv_zadd_self1        -> div_add_self1
  1329 zdiv_zadd_self2        -> div_add_self2
  1330 zdiv_zmult_self1       -> div_mult_self2_is_id
  1331 zdiv_zmult_self2       -> div_mult_self1_is_id
  1332 zdvd_triv_left         -> dvd_triv_left
  1333 zdvd_triv_right        -> dvd_triv_right
  1334 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1335 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1336 zmod_zadd_left_eq      -> mod_add_left_eq
  1337 zmod_zadd_right_eq     -> mod_add_right_eq
  1338 zmod_zadd_self1        -> mod_add_self1
  1339 zmod_zadd_self2        -> mod_add_self2
  1340 zmod_zadd1_eq          -> mod_add_eq
  1341 zmod_zdiff1_eq         -> mod_diff_eq
  1342 zmod_zdvd_zmod         -> mod_mod_cancel
  1343 zmod_zmod_cancel       -> mod_mod_cancel
  1344 zmod_zmult_self1       -> mod_mult_self2_is_0
  1345 zmod_zmult_self2       -> mod_mult_self1_is_0
  1346 zmod_1                 -> mod_by_1
  1347 zdiv_1                 -> div_by_1
  1348 zdvd_abs1              -> abs_dvd_iff
  1349 zdvd_abs2              -> dvd_abs_iff
  1350 zdvd_refl              -> dvd_refl
  1351 zdvd_trans             -> dvd_trans
  1352 zdvd_zadd              -> dvd_add
  1353 zdvd_zdiff             -> dvd_diff
  1354 zdvd_zminus_iff        -> dvd_minus_iff
  1355 zdvd_zminus2_iff       -> minus_dvd_iff
  1356 zdvd_zmultD            -> dvd_mult_right
  1357 zdvd_zmultD2           -> dvd_mult_left
  1358 zdvd_zmult_mono        -> mult_dvd_mono
  1359 zdvd_0_right           -> dvd_0_right
  1360 zdvd_0_left            -> dvd_0_left_iff
  1361 zdvd_1_left            -> one_dvd
  1362 zminus_dvd_iff         -> minus_dvd_iff
  1363 
  1364 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1365 
  1366 * The real numbers offer decimal input syntax: 12.34 is translated
  1367 into 1234/10^2. This translation is not reversed upon output.
  1368 
  1369 * Theory Library/Polynomial defines an abstract type 'a poly of
  1370 univariate polynomials with coefficients of type 'a.  In addition to
  1371 the standard ring operations, it also supports div and mod.  Code
  1372 generation is also supported, using list-style constructors.
  1373 
  1374 * Theory Library/Inner_Product defines a class of real_inner for real
  1375 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1376 => real.  Class real_inner is a subclass of real_normed_vector from
  1377 theory RealVector.
  1378 
  1379 * Theory Library/Product_Vector provides instances for the product
  1380 type 'a * 'b of several classes from RealVector and Inner_Product.
  1381 Definitions of addition, subtraction, scalar multiplication, norms,
  1382 and inner products are included.
  1383 
  1384 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1385 addition to the field operations, numerals and case syntax are also
  1386 supported.
  1387 
  1388 * Theory Library/Diagonalize provides constructive version of Cantor's
  1389 first diagonalization argument.
  1390 
  1391 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1392 zlcm (for int); carried together from various gcd/lcm developements in
  1393 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1394 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1395 may recover tupled syntax as follows:
  1396 
  1397     hide (open) const gcd
  1398     abbreviation gcd where
  1399       "gcd == (%(a, b). GCD.gcd a b)"
  1400     notation (output)
  1401       GCD.gcd ("gcd '(_, _')")
  1402 
  1403 The same works for lcm, zgcd, zlcm.
  1404 
  1405 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1406 instantiations for algebraic structures.  Removed some duplicate
  1407 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1408 
  1409 * ML antiquotation @{code} takes a constant as argument and generates
  1410 corresponding code in background and inserts name of the corresponding
  1411 resulting ML value/function/datatype constructor binding in place.
  1412 All occurrences of @{code} with a single ML block are generated
  1413 simultaneously.  Provides a generic and safe interface for
  1414 instrumentalizing code generation.  See
  1415 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1416 In future you ought to refrain from ad-hoc compiling generated SML
  1417 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1418 cannot refer to constants for which user-defined serializations are
  1419 set.  Refer to the corresponding ML counterpart directly in that
  1420 cases.
  1421 
  1422 * Command 'rep_datatype': instead of theorem names the command now
  1423 takes a list of terms denoting the constructors of the type to be
  1424 represented as datatype.  The characteristic theorems have to be
  1425 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1426 have disappeared in favour of existing ones:
  1427 
  1428     unit_induct                 ~> unit.induct
  1429     prod_induct                 ~> prod.induct
  1430     sum_induct                  ~> sum.induct
  1431     Suc_Suc_eq                  ~> nat.inject
  1432     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1433 
  1434 
  1435 *** HOL-Algebra ***
  1436 
  1437 * New locales for orders and lattices where the equivalence relation
  1438 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1439 locales use a record structure with field eq for the equivalence.
  1440 
  1441 * New theory of factorial domains.
  1442 
  1443 * Units_l_inv and Units_r_inv are now simp rules by default.
  1444 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1445 and/or r_inv will now also require deletion of these lemmas.
  1446 
  1447 * Renamed the following theorems, INCOMPATIBILITY:
  1448 
  1449 UpperD ~> Upper_memD
  1450 LowerD ~> Lower_memD
  1451 least_carrier ~> least_closed
  1452 greatest_carrier ~> greatest_closed
  1453 greatest_Lower_above ~> greatest_Lower_below
  1454 one_zero ~> carrier_one_zero
  1455 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1456 
  1457 
  1458 *** HOL-Nominal ***
  1459 
  1460 * Nominal datatypes can now contain type-variables.
  1461 
  1462 * Commands 'nominal_inductive' and 'equivariance' work with local
  1463 theory targets.
  1464 
  1465 * Nominal primrec can now works with local theory targets and its
  1466 specification syntax now conforms to the general format as seen in
  1467 'inductive' etc.
  1468 
  1469 * Method "perm_simp" honours the standard simplifier attributes
  1470 (no_asm), (no_asm_use) etc.
  1471 
  1472 * The new predicate #* is defined like freshness, except that on the
  1473 left hand side can be a set or list of atoms.
  1474 
  1475 * Experimental command 'nominal_inductive2' derives strong induction
  1476 principles for inductive definitions.  In contrast to
  1477 'nominal_inductive', which can only deal with a fixed number of
  1478 binders, it can deal with arbitrary expressions standing for sets of
  1479 atoms to be avoided.  The only inductive definition we have at the
  1480 moment that needs this generalisation is the typing rule for Lets in
  1481 the algorithm W:
  1482 
  1483  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1484  -----------------------------------------------------------------
  1485          Gamma |- Let x be t1 in t2 : T2
  1486 
  1487 In this rule one wants to avoid all the binders that are introduced by
  1488 "close Gamma T1".  We are looking for other examples where this
  1489 feature might be useful.  Please let us know.
  1490 
  1491 
  1492 *** HOLCF ***
  1493 
  1494 * Reimplemented the simplification procedure for proving continuity
  1495 subgoals.  The new simproc is extensible; users can declare additional
  1496 continuity introduction rules with the attribute [cont2cont].
  1497 
  1498 * The continuity simproc now uses a different introduction rule for
  1499 solving continuity subgoals on terms with lambda abstractions.  In
  1500 some rare cases the new simproc may fail to solve subgoals that the
  1501 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1502 Potential INCOMPATIBILITY.
  1503 
  1504 * Command 'fixrec': specification syntax now conforms to the general
  1505 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1506 examples.  INCOMPATIBILITY.
  1507 
  1508 
  1509 *** ZF ***
  1510 
  1511 * Proof of Zorn's Lemma for partial orders.
  1512 
  1513 
  1514 *** ML ***
  1515 
  1516 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1517 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1518 depends on multithreading, so timouts will not work before Poly/ML
  1519 5.2.1!
  1520 
  1521 * High-level support for concurrent ML programming, see
  1522 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1523 particularly convenient to organize independent functional
  1524 computations.  The concept of "synchronized variables" provides a
  1525 higher-order interface for components with shared state, avoiding the
  1526 delicate details of mutexes and condition variables.  (Requires
  1527 Poly/ML 5.2.1 or later.)
  1528 
  1529 * ML bindings produced via Isar commands are stored within the Isar
  1530 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1531 become thread-safe and work with undo as expected (concerning
  1532 top-level bindings, not side-effects on global references).
  1533 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1534 compiler at runtime; really global bindings need to be given outside a
  1535 theory.  (Requires Poly/ML 5.2 or later.)
  1536 
  1537 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1538 context.  Top-level ML bindings are stored within the proof context in
  1539 a purely sequential fashion, disregarding the nested proof structure.
  1540 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1541 proof.  (Requires Poly/ML 5.2 or later.)
  1542 
  1543 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1544 and Method.setup, as well as Isar commands 'attribute_setup' and
  1545 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1546 existing code accordingly, or use plain 'setup' together with old
  1547 Method.add_method.
  1548 
  1549 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1550 to 'a -> thm, while results are always tagged with an authentic oracle
  1551 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1552 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1553 accordingly.  Note that extra performance may be gained by producing
  1554 the cterm carefully, avoiding slow Thm.cterm_of.
  1555 
  1556 * Simplified interface for defining document antiquotations via
  1557 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1558 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1559 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1560 examples.
  1561 
  1562 * More systematic treatment of long names, abstract name bindings, and
  1563 name space operations.  Basic operations on qualified names have been
  1564 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1565 Long_Name.append.  Old type bstring has been mostly replaced by
  1566 abstract type binding (see structure Binding), which supports precise
  1567 qualification by packages and local theory targets, as well as proper
  1568 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1569 bstring values into Binding.name, or better pass through abstract
  1570 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1571 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1572 
  1573 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1574 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1575 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1576 
  1577 * Disposed old type and term read functions (Sign.read_def_typ,
  1578 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1579 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1580 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1581 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1582 resort for legacy applications.
  1583 
  1584 * Disposed old declarations, tactics, tactic combinators that refer to
  1585 the simpset or claset of an implicit theory (such as Addsimps,
  1586 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1587 embedded ML text, or local_simpset_of with a proper context passed as
  1588 explicit runtime argument.
  1589 
  1590 * Rules and tactics that read instantiations (read_instantiate,
  1591 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1592 context, which is required for parsing and type-checking.  Moreover,
  1593 the variables are specified as plain indexnames, not string encodings
  1594 thereof.  INCOMPATIBILITY.
  1595 
  1596 * Generic Toplevel.add_hook interface allows to analyze the result of
  1597 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1598 for theorem dependency output of transactions resulting in a new
  1599 theory state.
  1600 
  1601 * ML antiquotations: block-structured compilation context indicated by
  1602 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1603 
  1604   @{binding name}                         - basic name binding
  1605   @{let ?pat = term}                      - term abbreviation (HO matching)
  1606   @{note name = fact}                     - fact abbreviation
  1607   @{thm fact}                             - singleton fact (with attributes)
  1608   @{thms fact}                            - general fact (with attributes)
  1609   @{lemma prop by method}                 - singleton goal
  1610   @{lemma prop by meth1 meth2}            - singleton goal
  1611   @{lemma prop1 ... propN by method}      - general goal
  1612   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1613   @{lemma (open) ...}                     - open derivation
  1614 
  1615 
  1616 *** System ***
  1617 
  1618 * The Isabelle "emacs" tool provides a specific interface to invoke
  1619 Proof General / Emacs, with more explicit failure if that is not
  1620 installed (the old isabelle-interface script silently falls back on
  1621 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1622 installation location of the Proof General distribution.
  1623 
  1624 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1625 the Isabelle process into a JVM/Scala application.  See
  1626 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1627 process wrapper has been discontinued.)
  1628 
  1629 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1630 
  1631 * Various status messages (with exact source position information) are
  1632 emitted, if proper markup print mode is enabled.  This allows
  1633 user-interface components to provide detailed feedback on internal
  1634 prover operations.
  1635 
  1636 
  1637 
  1638 New in Isabelle2008 (June 2008)
  1639 -------------------------------
  1640 
  1641 *** General ***
  1642 
  1643 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1644 and updated, with formally checked references as hyperlinks.
  1645 
  1646 * Theory loader: use_thy (and similar operations) no longer set the
  1647 implicit ML context, which was occasionally hard to predict and in
  1648 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1649 provides a proper context already.
  1650 
  1651 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1652 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1653 'use' within a theory file will do the job.
  1654 
  1655 * Name space merge now observes canonical order, i.e. the second space
  1656 is inserted into the first one, while existing entries in the first
  1657 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1658 swap theory imports.
  1659 
  1660 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1661 INCOMPATIBILITY in identifier syntax etc.
  1662 
  1663 * Outer syntax: string tokens no longer admit escaped white space,
  1664 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1665 white space without escapes.
  1666 
  1667 * Outer syntax: string tokens may contain arbitrary character codes
  1668 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1669 "foo_bar".
  1670 
  1671 
  1672 *** Pure ***
  1673 
  1674 * Context-dependent token translations.  Default setup reverts locally
  1675 fixed variables, and adds hilite markup for undeclared frees.
  1676 
  1677 * Unused theorems can be found using the new command 'unused_thms'.
  1678 There are three ways of invoking it:
  1679 
  1680 (1) unused_thms
  1681      Only finds unused theorems in the current theory.
  1682 
  1683 (2) unused_thms thy_1 ... thy_n -
  1684      Finds unused theorems in the current theory and all of its ancestors,
  1685      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1686 
  1687 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1688      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1689      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1690      their ancestors.
  1691 
  1692 In order to increase the readability of the list produced by
  1693 unused_thms, theorems that have been created by a particular instance
  1694 of a theory command such as 'inductive' or 'function' are considered
  1695 to belong to the same "group", meaning that if at least one theorem in
  1696 this group is used, the other theorems in the same group are no longer
  1697 reported as unused.  Moreover, if all theorems in the group are
  1698 unused, only one theorem in the group is displayed.
  1699 
  1700 Note that proof objects have to be switched on in order for
  1701 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1702 usually the case when using Proof General with the default settings).
  1703 
  1704 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1705 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1706 duplicate fact bindings, or even accidental fact duplications.  Note
  1707 that tools may maintain dynamically scoped facts systematically, using
  1708 PureThy.add_thms_dynamic.
  1709 
  1710 * Command 'hide' now allows to hide from "fact" name space as well.
  1711 
  1712 * Eliminated destructive theorem database, simpset, claset, and
  1713 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1714 update of theories within ML code.
  1715 
  1716 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1717 INCOMPATIBILITY, object-logics depending on former Pure require
  1718 additional setup PureThy.old_appl_syntax_setup; object-logics
  1719 depending on former CPure need to refer to Pure.
  1720 
  1721 * Commands 'use' and 'ML' are now purely functional, operating on
  1722 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1723 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1724 INCOMPATIBILITY.
  1725 
  1726 * Command 'setup': discontinued implicit version with ML reference.
  1727 
  1728 * Instantiation target allows for simultaneous specification of class
  1729 instance operations together with an instantiation proof.
  1730 Type-checking phase allows to refer to class operations uniformly.
  1731 See src/HOL/Complex/Complex.thy for an Isar example and
  1732 src/HOL/Library/Eval.thy for an ML example.
  1733 
  1734 * Indexing of literal facts: be more serious about including only
  1735 facts from the visible specification/proof context, but not the
  1736 background context (locale etc.).  Affects `prop` notation and method
  1737 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1738 situations.
  1739 
  1740 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1741 "(open)" option, which used to expose internal bound variables to the
  1742 proof text.
  1743 
  1744 * Isar statements: removed obsolete case "rule_context".
  1745 INCOMPATIBILITY, better use explicit fixes/assumes.
  1746 
  1747 * Locale proofs: default proof step now includes 'unfold_locales';
  1748 hence 'proof' without argument may be used to unfold locale
  1749 predicates.
  1750 
  1751 
  1752 *** Document preparation ***
  1753 
  1754 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1755 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1756 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1757 spot); renamed link color from "darkblue" to "linkcolor" (default
  1758 value unchanged, can be redefined via \definecolor); no longer sets
  1759 "a4paper" option (unnecessary or even intrusive).
  1760 
  1761 * Antiquotation @{lemma A method} proves proposition A by the given
  1762 method (either a method name or a method name plus (optional) method
  1763 arguments in parentheses) and prints A just like @{prop A}.
  1764 
  1765 
  1766 *** HOL ***
  1767 
  1768 * New primrec package.  Specification syntax conforms in style to
  1769 definition/function/....  No separate induction rule is provided.  The
  1770 "primrec" command distinguishes old-style and new-style specifications
  1771 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1772 When adjusting theories, beware: constants stemming from new-style
  1773 primrec specifications have authentic syntax.
  1774 
  1775 * Metis prover is now an order of magnitude faster, and also works
  1776 with multithreading.
  1777 
  1778 * Metis: the maximum number of clauses that can be produced from a
  1779 theorem is now given by the attribute max_clauses.  Theorems that
  1780 exceed this number are ignored, with a warning printed.
  1781 
  1782 * Sledgehammer no longer produces structured proofs by default. To
  1783 enable, declare [[sledgehammer_full = true]].  Attributes
  1784 reconstruction_modulus, reconstruction_sorts renamed
  1785 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1786 
  1787 * Method "induct_scheme" derives user-specified induction rules
  1788 from well-founded induction and completeness of patterns. This factors
  1789 out some operations that are done internally by the function package
  1790 and makes them available separately.  See
  1791 src/HOL/ex/Induction_Scheme.thy for examples.
  1792 
  1793 * More flexible generation of measure functions for termination
  1794 proofs: Measure functions can be declared by proving a rule of the
  1795 form "is_measure f" and giving it the [measure_function] attribute.
  1796 The "is_measure" predicate is logically meaningless (always true), and
  1797 just guides the heuristic.  To find suitable measure functions, the
  1798 termination prover sets up the goal "is_measure ?f" of the appropriate
  1799 type and generates all solutions by prolog-style backwards proof using
  1800 the declared rules.
  1801 
  1802 This setup also deals with rules like 
  1803 
  1804   "is_measure f ==> is_measure (list_size f)"
  1805 
  1806 which accommodates nested datatypes that recurse through lists.
  1807 Similar rules are predeclared for products and option types.
  1808 
  1809 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1810 
  1811   INCOMPATIBILITIES:
  1812 
  1813   - Definitions of overloaded constants on sets have to be replaced by
  1814     definitions on => and bool.
  1815 
  1816   - Some definitions of overloaded operators on sets can now be proved
  1817     using the definitions of the operators on => and bool.  Therefore,
  1818     the following theorems have been renamed:
  1819 
  1820       subset_def   -> subset_eq
  1821       psubset_def  -> psubset_eq
  1822       set_diff_def -> set_diff_eq
  1823       Compl_def    -> Compl_eq
  1824       Sup_set_def  -> Sup_set_eq
  1825       Inf_set_def  -> Inf_set_eq
  1826       sup_set_def  -> sup_set_eq
  1827       inf_set_def  -> inf_set_eq
  1828 
  1829   - Due to the incompleteness of the HO unification algorithm, some
  1830     rules such as subst may require manual instantiation, if some of
  1831     the unknowns in the rule is a set.
  1832 
  1833   - Higher order unification and forward proofs:
  1834     The proof pattern
  1835 
  1836       have "P (S::'a set)" <...>
  1837       then have "EX S. P S" ..
  1838 
  1839     no longer works (due to the incompleteness of the HO unification
  1840     algorithm) and must be replaced by the pattern
  1841 
  1842       have "EX S. P S"
  1843       proof
  1844         show "P S" <...>
  1845       qed
  1846 
  1847   - Calculational reasoning with subst (or similar rules):
  1848     The proof pattern
  1849 
  1850       have "P (S::'a set)" <...>
  1851       also have "S = T" <...>
  1852       finally have "P T" .
  1853 
  1854     no longer works (for similar reasons as the previous example) and
  1855     must be replaced by something like
  1856 
  1857       have "P (S::'a set)" <...>
  1858       moreover have "S = T" <...>
  1859       ultimately have "P T" by simp
  1860 
  1861   - Tactics or packages written in ML code:
  1862     Code performing pattern matching on types via
  1863 
  1864       Type ("set", [T]) => ...
  1865 
  1866     must be rewritten. Moreover, functions like strip_type or
  1867     binder_types no longer return the right value when applied to a
  1868     type of the form
  1869 
  1870       T1 => ... => Tn => U => bool
  1871 
  1872     rather than
  1873 
  1874       T1 => ... => Tn => U set
  1875 
  1876 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1877 Wellfounded_Relations to theory Wellfounded.
  1878 
  1879 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1880 
  1881 * Class finite no longer treats UNIV as class parameter.  Use class
  1882 enum from theory Library/Enum instead to achieve a similar effect.
  1883 INCOMPATIBILITY.
  1884 
  1885 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1886 and "Cons".  INCOMPATIBILITY.
  1887 
  1888 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1889 Potential INCOMPATIBILITY.
  1890 
  1891 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1892 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1893 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1894 
  1895 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1896 the same name in theory Orderings:
  1897 
  1898   less_trans
  1899   less_linear
  1900   le_imp_less_or_eq
  1901   le_less_trans
  1902   less_le_trans
  1903   less_not_sym
  1904   less_asym
  1905 
  1906 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1907 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1908 and different variable names.
  1909 
  1910 * Library/Option_ord.thy: Canonical order on option type.
  1911 
  1912 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1913 finite maps.
  1914 
  1915 * Library/Countable.thy: Type class for countable types.
  1916 
  1917 * Theory Int: The representation of numerals has changed.  The infix
  1918 operator BIT and the bit datatype with constructors B0 and B1 have
  1919 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1920 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1921 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1922 accordingly.
  1923 
  1924 * Theory Nat: definition of <= and < on natural numbers no longer
  1925 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1926 le_def and less_def have disappeared.  Consider lemmas not_less
  1927 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1928 
  1929 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1930 (whose purpose mainly is for various fold_set functionals) have been
  1931 abandoned in favor of the existing algebraic classes
  1932 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1933 lower_semilattice (resp. upper_semilattice) and linorder.
  1934 INCOMPATIBILITY.
  1935 
  1936 * Theory Transitive_Closure: induct and cases rules now declare proper
  1937 case_names ("base" and "step").  INCOMPATIBILITY.
  1938 
  1939 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1940 lattices.  The form set-specific version is available as
  1941 Inductive.lfp_ordinal_induct_set.
  1942 
  1943 * Renamed theorems "power.simps" to "power_int.simps".
  1944 INCOMPATIBILITY.
  1945 
  1946 * Class semiring_div provides basic abstract properties of semirings
  1947 with division and modulo operations.  Subsumes former class dvd_mod.
  1948 
  1949 * Merged theories IntDef, Numeral and IntArith into unified theory
  1950 Int.  INCOMPATIBILITY.
  1951 
  1952 * Theory Library/Code_Index: type "index" now represents natural
  1953 numbers rather than integers.  INCOMPATIBILITY.
  1954 
  1955 * New class "uminus" with operation "uminus" (split of from class
  1956 "minus" which now only has operation "minus", binary).
  1957 INCOMPATIBILITY.
  1958 
  1959 * Constants "card", "internal_split", "option_map" now with authentic
  1960 syntax.  INCOMPATIBILITY.
  1961 
  1962 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1963 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1964 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1965 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1966 Sup_set_def, le_def, less_def, option_map_def now with object
  1967 equality.  INCOMPATIBILITY.
  1968 
  1969 * Records. Removed K_record, and replaced it by pure lambda term
  1970 %x. c. The simplifier setup is now more robust against eta expansion.
  1971 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1972 
  1973 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1974 
  1975 * Library/ListVector: new theory of arithmetic vector operations.
  1976 
  1977 * Library/Order_Relation: new theory of various orderings as sets of
  1978 pairs.  Defines preorders, partial orders, linear orders and
  1979 well-orders on sets and on types.
  1980 
  1981 
  1982 *** ZF ***
  1983 
  1984 * Renamed some theories to allow to loading both ZF and HOL in the
  1985 same session:
  1986 
  1987   Datatype  -> Datatype_ZF
  1988   Inductive -> Inductive_ZF
  1989   Int       -> Int_ZF
  1990   IntDiv    -> IntDiv_ZF
  1991   Nat       -> Nat_ZF
  1992   List      -> List_ZF
  1993   Main      -> Main_ZF
  1994 
  1995 INCOMPATIBILITY: ZF theories that import individual theories below
  1996 Main might need to be adapted.  Regular theory Main is still
  1997 available, as trivial extension of Main_ZF.
  1998 
  1999 
  2000 *** ML ***
  2001 
  2002 * ML within Isar: antiquotation @{const name} or @{const
  2003 name(typargs)} produces statically-checked Const term.
  2004 
  2005 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2006 (of the same name).  Removed obsolete print command.
  2007 
  2008 * Removed obsolete "use_legacy_bindings" function.
  2009 
  2010 * The ``print mode'' is now a thread-local value derived from a global
  2011 template (the former print_mode reference), thus access becomes
  2012 non-critical.  The global print_mode reference is for session
  2013 management only; user-code should use print_mode_value,
  2014 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2015 
  2016 * Functions system/system_out provide a robust way to invoke external
  2017 shell commands, with propagation of interrupts (requires Poly/ML
  2018 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2019 
  2020 
  2021 *** System ***
  2022 
  2023 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2024 in accordance with Proof General 3.7, which prefers GNU emacs.
  2025 
  2026 * isatool tty runs Isabelle process with plain tty interaction;
  2027 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2028 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2029 
  2030 * isatool browser now works with Cygwin as well, using general
  2031 "javapath" function defined in Isabelle process environment.
  2032 
  2033 * YXML notation provides a simple and efficient alternative to
  2034 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2035 isatool yxml as described in the Isabelle system manual.
  2036 
  2037 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2038 provides general wrapper for managing an Isabelle process in a robust
  2039 fashion, with ``cooked'' output from stdin/stderr.
  2040 
  2041 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2042 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2043 
  2044 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2045 way of changing the user's settings is via
  2046 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2047 script.
  2048 
  2049 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2050 cores of the underlying machine, which is a good starting point for
  2051 optimal performance tuning.  The corresponding usedir option -M allows
  2052 "max" as an alias for "0".  WARNING: does not work on certain versions
  2053 of Mac OS (with Poly/ML 5.1).
  2054 
  2055 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2056 adverse effect of Isabelle flooding interactive front-ends (notably
  2057 ProofGeneral / XEmacs).
  2058 
  2059 
  2060 
  2061 New in Isabelle2007 (November 2007)
  2062 -----------------------------------
  2063 
  2064 *** General ***
  2065 
  2066 * More uniform information about legacy features, notably a
  2067 warning/error of "Legacy feature: ...", depending on the state of the
  2068 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2069 legacy features will disappear eventually.
  2070 
  2071 * Theory syntax: the header format ``theory A = B + C:'' has been
  2072 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2073 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2074 
  2075 * Theory syntax: the old non-Isar theory file format has been
  2076 discontinued altogether.  Note that ML proof scripts may still be used
  2077 with Isar theories; migration is usually quite simple with the ML
  2078 function use_legacy_bindings.  INCOMPATIBILITY.
  2079 
  2080 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2081 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2082 quotes.
  2083 
  2084 * Theory loader: be more serious about observing the static theory
  2085 header specifications (including optional directories), but not the
  2086 accidental file locations of previously successful loads.  The strict
  2087 update policy of former update_thy is now already performed by
  2088 use_thy, so the former has been removed; use_thys updates several
  2089 theories simultaneously, just as 'imports' within a theory header
  2090 specification, but without merging the results.  Potential
  2091 INCOMPATIBILITY: may need to refine theory headers and commands
  2092 ROOT.ML which depend on load order.
  2093 
  2094 * Theory loader: optional support for content-based file
  2095 identification, instead of the traditional scheme of full physical
  2096 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2097 (cf. the system manual).  The new scheme allows to work with
  2098 non-finished theories in persistent session images, such that source
  2099 files may be moved later on without requiring reloads.
  2100 
  2101 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2102 file (with the same base name as the theory) are considered a legacy
  2103 feature, which will disappear eventually. Even now, the theory loader
  2104 no longer maintains dependencies on such files.
  2105 
  2106 * Syntax: the scope for resolving ambiguities via type-inference is
  2107 now limited to individual terms, instead of whole simultaneous
  2108 specifications as before. This greatly reduces the complexity of the
  2109 syntax module and improves flexibility by separating parsing and
  2110 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2111 'fixes' etc.) are required in rare situations.
  2112 
  2113 * Syntax: constants introduced by new-style packages ('definition',
  2114 'abbreviation' etc.) are passed through the syntax module in
  2115 ``authentic mode''. This means that associated mixfix annotations
  2116 really stick to such constants, independently of potential name space
  2117 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2118 trees are represented slightly differently, may need to adapt syntax
  2119 translations accordingly. Use CONST marker in 'translations' and
  2120 @{const_syntax} antiquotation in 'parse_translation' etc.
  2121 
  2122 * Legacy goal package: reduced interface to the bare minimum required
  2123 to keep existing proof scripts running.  Most other user-level
  2124 functions are now part of the OldGoals structure, which is *not* open
  2125 by default (consider isatool expandshort before open OldGoals).
  2126 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2127 these tend to cause confusion about the actual goal (!) context being
  2128 used here, which is not necessarily the same as the_context().
  2129 
  2130 * Command 'find_theorems': supports "*" wild-card in "name:"
  2131 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2132 support a specific search form (see ProofGeneral/CHANGES).
  2133 
  2134 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2135 by default, which means that "prems" (and also "fixed variables") are
  2136 suppressed from proof state output.  Note that the ProofGeneral
  2137 settings mechanism allows to change and save options persistently, but
  2138 older versions of Isabelle will fail to start up if a negative prems
  2139 limit is imposed.
  2140 
  2141 * Local theory targets may be specified by non-nested blocks of
  2142 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2143 contain definitions, theorems etc., including any derived mechanism
  2144 that has been implemented on top of these primitives.  This concept
  2145 generalizes the existing ``theorem (in ...)'' towards more versatility
  2146 and scalability.
  2147 
  2148 * Proof General interface: proper undo of final 'end' command;
  2149 discontinued Isabelle/classic mode (ML proof scripts).
  2150 
  2151 
  2152 *** Document preparation ***
  2153 
  2154 * Added antiquotation @{theory name} which prints the given name,
  2155 after checking that it refers to a valid ancestor theory in the
  2156 current context.
  2157 
  2158 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2159 check the given source text as ML type/structure, printing verbatim.
  2160 
  2161 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2162 "c args == rhs" given in the current context.  (Any number of
  2163 arguments may be given on the LHS.)
  2164 
  2165 
  2166 *** Pure ***
  2167 
  2168 * The 'class' package offers a combination of axclass and locale to
  2169 achieve Haskell-like type classes in Isabelle.  Definitions and
  2170 theorems within a class context produce both relative results (with
  2171 implicit parameters according to the locale context), and polymorphic
  2172 constants with qualified polymorphism (according to the class
  2173 context).  Within the body context of a 'class' target, a separate
  2174 syntax layer ("user space type system") takes care of converting
  2175 between global polymorphic consts and internal locale representation.
  2176 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2177 "isatool doc classes" provides a tutorial.
  2178 
  2179 * Generic code generator framework allows to generate executable
  2180 code for ML and Haskell (including Isabelle classes).  A short usage
  2181 sketch:
  2182 
  2183     internal compilation:
  2184         export_code <list of constants (term syntax)> in SML
  2185     writing SML code to a file:
  2186         export_code <list of constants (term syntax)> in SML <filename>
  2187     writing OCaml code to a file:
  2188         export_code <list of constants (term syntax)> in OCaml <filename>
  2189     writing Haskell code to a bunch of files:
  2190         export_code <list of constants (term syntax)> in Haskell <filename>
  2191 
  2192     evaluating closed propositions to True/False using code generation:
  2193         method ``eval''
  2194 
  2195 Reasonable default setup of framework in HOL.
  2196 
  2197 Theorem attributs for selecting and transforming function equations theorems:
  2198 
  2199     [code fun]:        select a theorem as function equation for a specific constant
  2200     [code fun del]:    deselect a theorem as function equation for a specific constant
  2201     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2202     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2203 
  2204 User-defined serializations (target in {SML, OCaml, Haskell}):
  2205 
  2206     code_const <and-list of constants (term syntax)>
  2207       {(target) <and-list of const target syntax>}+
  2208 
  2209     code_type <and-list of type constructors>
  2210       {(target) <and-list of type target syntax>}+
  2211 
  2212     code_instance <and-list of instances>
  2213       {(target)}+
  2214         where instance ::= <type constructor> :: <class>
  2215 
  2216     code_class <and_list of classes>
  2217       {(target) <and-list of class target syntax>}+
  2218         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2219 
  2220 code_instance and code_class only are effective to target Haskell.
  2221 
  2222 For example usage see src/HOL/ex/Codegenerator.thy and
  2223 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2224 generation from Isabelle/HOL theories is available via "isatool doc
  2225 codegen".
  2226 
  2227 * Code generator: consts in 'consts_code' Isar commands are now
  2228 referred to by usual term syntax (including optional type
  2229 annotations).
  2230 
  2231 * Command 'no_translations' removes translation rules from theory
  2232 syntax.
  2233 
  2234 * Overloaded definitions are now actually checked for acyclic
  2235 dependencies.  The overloading scheme is slightly more general than
  2236 that of Haskell98, although Isabelle does not demand an exact
  2237 correspondence to type class and instance declarations.
  2238 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2239 exotic versions of overloading -- at the discretion of the user!
  2240 
  2241 Polymorphic constants are represented via type arguments, i.e. the
  2242 instantiation that matches an instance against the most general
  2243 declaration given in the signature.  For example, with the declaration
  2244 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2245 as c(nat).  Overloading is essentially simultaneous structural
  2246 recursion over such type arguments.  Incomplete specification patterns
  2247 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2248 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2249 Command 'print_theory' outputs the normalized system of recursive
  2250 equations, see section "definitions".
  2251 
  2252 * Configuration options are maintained within the theory or proof
  2253 context (with name and type bool/int/string), providing a very simple
  2254 interface to a poor-man's version of general context data.  Tools may
  2255 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2256 these values using Config.get etc.  Users may change options via an
  2257 associated attribute of the same name.  This form of context
  2258 declaration works particularly well with commands 'declare' or
  2259 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2260 very easy to avoid global references, which would not observe Isar
  2261 toplevel undo/redo and fail to work with multithreading.
  2262 
  2263 Various global ML references of Pure and HOL have been turned into
  2264 configuration options:
  2265 
  2266   Unify.search_bound		unify_search_bound
  2267   Unify.trace_bound		unify_trace_bound
  2268   Unify.trace_simp		unify_trace_simp
  2269   Unify.trace_types		unify_trace_types
  2270   Simplifier.simp_depth_limit	simp_depth_limit
  2271   Blast.depth_limit		blast_depth_limit
  2272   DatatypeProp.dtK		datatype_distinctness_limit
  2273   fast_arith_neq_limit  	fast_arith_neq_limit
  2274   fast_arith_split_limit	fast_arith_split_limit
  2275 
  2276 * Named collections of theorems may be easily installed as context
  2277 data using the functor NamedThmsFun (see also
  2278 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2279 attributes; there is also a toplevel print command.  This facility is
  2280 just a common case of general context data, which is the preferred way
  2281 for anything more complex than just a list of facts in canonical
  2282 order.
  2283 
  2284 * Isar: command 'declaration' augments a local theory by generic
  2285 declaration functions written in ML.  This enables arbitrary content
  2286 being added to the context, depending on a morphism that tells the
  2287 difference of the original declaration context wrt. the application
  2288 context encountered later on.
  2289 
  2290 * Isar: proper interfaces for simplification procedures.  Command
  2291 'simproc_setup' declares named simprocs (with match patterns, and body
  2292 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2293 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2294 
  2295 * Isar: an extra pair of brackets around attribute declarations
  2296 abbreviates a theorem reference involving an internal dummy fact,
  2297 which will be ignored later --- only the effect of the attribute on
  2298 the background context will persist.  This form of in-place
  2299 declarations is particularly useful with commands like 'declare' and
  2300 'using', for example ``have A using [[simproc a]] by simp''.
  2301 
  2302 * Isar: method "assumption" (and implicit closing of subproofs) now
  2303 takes simple non-atomic goal assumptions into account: after applying
  2304 an assumption as a rule the resulting subgoals are solved by atomic
  2305 assumption steps.  This is particularly useful to finish 'obtain'
  2306 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2307 without referring to the original premise "!!x. P x ==> thesis" in the
  2308 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2309 more permissive.
  2310 
  2311 * Isar: implicit use of prems from the Isar proof context is
  2312 considered a legacy feature.  Common applications like ``have A .''
  2313 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2314 referencing facts explicitly here improves readability and
  2315 maintainability of proof texts.
  2316 
  2317 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2318 the obtained context from the course of reasoning!  For example:
  2319 
  2320   assume "EX x y. A x & B y"   -- "any previous fact"
  2321   then guess x and y by clarify
  2322 
  2323 This technique is potentially adventurous, depending on the facts and
  2324 proof tools being involved here.
  2325 
  2326 * Isar: known facts from the proof context may be specified as literal
  2327 propositions, using ASCII back-quote syntax.  This works wherever
  2328 named facts used to be allowed so far, in proof commands, proof
  2329 methods, attributes etc.  Literal facts are retrieved from the context
  2330 according to unification of type and term parameters.  For example,
  2331 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2332 theorems in the current context, then these are valid literal facts:
  2333 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2334 
  2335 There is also a proof method "fact" which does the same composition
  2336 for explicit goal states, e.g. the following proof texts coincide with
  2337 certain special cases of literal facts:
  2338 
  2339   have "A" by fact                 ==  note `A`
  2340   have "A ==> B" by fact           ==  note `A ==> B`
  2341   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2342   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2343 
  2344 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2345 outer syntax.  Thus symbolic identifiers may be used without
  2346 additional white space in declarations like this: ``assume *: A''.
  2347 
  2348 * Isar: 'print_facts' prints all local facts of the current context,
  2349 both named and unnamed ones.
  2350 
  2351 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2352 
  2353   def x == "t" and y == "u"
  2354 
  2355 * Isar: added command 'unfolding', which is structurally similar to
  2356 'using', but affects both the goal state and facts by unfolding given
  2357 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2358 'unfolded' attribute may be replaced by first-class proof text.
  2359 
  2360 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2361 and command 'unfolding' now all support object-level equalities
  2362 (potentially conditional).  The underlying notion of rewrite rule is
  2363 analogous to the 'rule_format' attribute, but *not* that of the
  2364 Simplifier (which is usually more generous).
  2365 
  2366 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2367 premises of a theorem by n. Useful in conjunction with drule.
  2368 
  2369 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2370 method expression within a sandbox consisting of the first N
  2371 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2372 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2373 simplifies all new goals that emerge from applying rule foo to the
  2374 originally first one.
  2375 
  2376 * Isar: schematic goals are no longer restricted to higher-order
  2377 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2378 expected.
  2379 
  2380 * Isar: the conclusion of a long theorem statement is now either
  2381 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2382 (essentially a disjunction of cases with local parameters and
  2383 assumptions).  The latter allows to express general elimination rules
  2384 adequately; in this notation common elimination rules look like this:
  2385 
  2386   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2387     assumes "EX x. P x"
  2388     obtains x where "P x"
  2389 
  2390   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2391     assumes "A & B"
  2392     obtains A and B
  2393 
  2394   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2395     assumes "A | B"
  2396     obtains
  2397       A
  2398     | B
  2399 
  2400 The subsequent classical rules even refer to the formal "thesis"
  2401 explicitly:
  2402 
  2403   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2404     obtains "~ thesis"
  2405 
  2406   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2407     obtains "thesis ==> something"
  2408 
  2409 The actual proof of an 'obtains' statement is analogous to that of the
  2410 Isar proof element 'obtain', only that there may be several cases.
  2411 Optional case names may be specified in parentheses; these will be
  2412 available both in the present proof and as annotations in the
  2413 resulting rule, for later use with the 'cases' method (cf. attribute
  2414 case_names).
  2415 
  2416 * Isar: the assumptions of a long theorem statement are available as
  2417 "assms" fact in the proof context.  This is more appropriate than the
  2418 (historical) "prems", which refers to all assumptions of the current
  2419 context, including those from the target locale, proof body etc.
  2420 
  2421 * Isar: 'print_statement' prints theorems from the current theory or
  2422 proof context in long statement form, according to the syntax of a
  2423 top-level lemma.
  2424 
  2425 * Isar: 'obtain' takes an optional case name for the local context
  2426 introduction rule (default "that").
  2427 
  2428 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2429 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2430 to occur.
  2431 
  2432 * Pure: syntax "CONST name" produces a fully internalized constant
  2433 according to the current context.  This is particularly useful for
  2434 syntax translations that should refer to internal constant
  2435 representations independently of name spaces.
  2436 
  2437 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2438 instead of "FOO ". This allows multiple binder declarations to coexist
  2439 in the same context.  INCOMPATIBILITY.
  2440 
  2441 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2442 primitive that also works in a locale context (both for constants and
  2443 fixed variables). Type declaration and internal syntactic representation
  2444 of given constants retrieved from the context. Likewise, the
  2445 'no_notation' command allows to remove given syntax annotations from the
  2446 current context.
  2447 
  2448 * Isar/locales: new derived specification elements 'axiomatization',
  2449 'definition', 'abbreviation', which support type-inference, admit
  2450 object-level specifications (equality, equivalence).  See also the
  2451 isar-ref manual.  Examples:
  2452 
  2453   axiomatization
  2454     eq  (infix "===" 50) where
  2455     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2456 
  2457   definition "f x y = x + y + 1"
  2458   definition g where "g x = f x x"
  2459 
  2460   abbreviation
  2461     neq  (infix "=!=" 50) where
  2462     "x =!= y == ~ (x === y)"
  2463 
  2464 These specifications may be also used in a locale context.  Then the
  2465 constants being introduced depend on certain fixed parameters, and the
  2466 constant name is qualified by the locale base name.  An internal
  2467 abbreviation takes care for convenient input and output, making the
  2468 parameters implicit and using the original short name.  See also
  2469 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2470 entities from a monomorphic theory.
  2471 
  2472 Presently, abbreviations are only available 'in' a target locale, but
  2473 not inherited by general import expressions.  Also note that
  2474 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2475 'translations' in common applications.  The "no_abbrevs" print mode
  2476 prevents folding of abbreviations in term output.
  2477 
  2478 Concrete syntax is attached to specified constants in internal form,
  2479 independently of name spaces.  The parse tree representation is
  2480 slightly different -- use 'notation' instead of raw 'syntax', and
  2481 'translations' with explicit "CONST" markup to accommodate this.
  2482 
  2483 * Pure/Isar: unified syntax for new-style specification mechanisms
  2484 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2485 full type inference and dummy patterns ("_").  For example:
  2486 
  2487   definition "K x _ = x"
  2488 
  2489   inductive conj for A B
  2490   where "A ==> B ==> conj A B"
  2491 
  2492 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2493 the current context.  Print mode "no_abbrevs" prevents inversion of
  2494 abbreviations on output.
  2495 
  2496 * Isar/locales: improved parameter handling: use of locales "var" and
  2497 "struct" no longer necessary; - parameter renamings are no longer
  2498 required to be injective.  For example, this allows to define
  2499 endomorphisms as locale endom = homom mult mult h.
  2500 
  2501 * Isar/locales: changed the way locales with predicates are defined.
  2502 Instead of accumulating the specification, the imported expression is
  2503 now an interpretation.  INCOMPATIBILITY: different normal form of
  2504 locale expressions.  In particular, in interpretations of locales with
  2505 predicates, goals repesenting already interpreted fragments are not
  2506 removed automatically.  Use methods `intro_locales' and
  2507 `unfold_locales'; see below.
  2508 
  2509 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2510 provide backward reasoning on locales predicates.  The methods are
  2511 aware of interpretations and discharge corresponding goals.
  2512 `intro_locales' is less aggressive then `unfold_locales' and does not
  2513 unfold predicates to assumptions.
  2514 
  2515 * Isar/locales: the order in which locale fragments are accumulated
  2516 has changed.  This enables to override declarations from fragments due
  2517 to interpretations -- for example, unwanted simp rules.
  2518 
  2519 * Isar/locales: interpretation in theories and proof contexts has been
  2520 extended.  One may now specify (and prove) equations, which are
  2521 unfolded in interpreted theorems.  This is useful for replacing
  2522 defined concepts (constants depending on locale parameters) by
  2523 concepts already existing in the target context.  Example:
  2524 
  2525   interpretation partial_order ["op <= :: [int, int] => bool"]
  2526     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2527 
  2528 Typically, the constant `partial_order.less' is created by a
  2529 definition specification element in the context of locale
  2530 partial_order.
  2531 
  2532 * Method "induct": improved internal context management to support
  2533 local fixes and defines on-the-fly. Thus explicit meta-level
  2534 connectives !!  and ==> are rarely required anymore in inductive goals
  2535 (using object-logic connectives for this purpose has been long
  2536 obsolete anyway). Common proof patterns are explained in
  2537 src/HOL/Induct/Common_Patterns.thy, see also
  2538 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2539 examples.
  2540 
  2541 * Method "induct": improved handling of simultaneous goals. Instead of
  2542 introducing object-level conjunction, the statement is now split into
  2543 several conclusions, while the corresponding symbolic cases are nested
  2544 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2545 see src/HOL/Induct/Common_Patterns.thy, for example.
  2546 
  2547 * Method "induct": mutual induction rules are now specified as a list
  2548 of rule sharing the same induction cases. HOL packages usually provide
  2549 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2550 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2551 mutual induction rules differently, i.e. like this:
  2552 
  2553   (induct rule: foo_bar.inducts)
  2554   (induct set: foo bar)
  2555   (induct pred: foo bar)
  2556   (induct type: foo bar)
  2557 
  2558 The ML function ProjectRule.projections turns old-style rules into the
  2559 new format.
  2560 
  2561 * Method "coinduct": dual of induction, see
  2562 src/HOL/Library/Coinductive_List.thy for various examples.
  2563 
  2564 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2565 considered a legacy feature.
  2566 
  2567 * Attribute "symmetric" produces result with standardized schematic
  2568 variables (index 0).  Potential INCOMPATIBILITY.
  2569 
  2570 * Simplifier: by default the simplifier trace only shows top level
  2571 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2572 default. Thus there is less danger of being flooded by the trace. The
  2573 trace indicates where parts have been suppressed.
  2574   
  2575 * Provers/classical: removed obsolete classical version of elim_format
  2576 attribute; classical elim/dest rules are now treated uniformly when
  2577 manipulating the claset.
  2578 
  2579 * Provers/classical: stricter checks to ensure that supplied intro,
  2580 dest and elim rules are well-formed; dest and elim rules must have at
  2581 least one premise.
  2582 
  2583 * Provers/classical: attributes dest/elim/intro take an optional
  2584 weight argument for the rule (just as the Pure versions).  Weights are
  2585 ignored by automated tools, but determine the search order of single
  2586 rule steps.
  2587 
  2588 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2589 where the body does not mention the bound variable.  Note that dummy
  2590 patterns implicitly depend on their context of bounds, which makes
  2591 "{_. _}" match any set comprehension as expected.  Potential
  2592 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2593 constant "_idtdummy" in the binding position.
  2594 
  2595 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2596 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2597 for example "A -> B" => "Pi A (%_. B)".
  2598 
  2599 * Pure: 'class_deps' command visualizes the subclass relation, using
  2600 the graph browser tool.
  2601 
  2602 * Pure: 'print_theory' now suppresses certain internal declarations by
  2603 default; use '!' option for full details.
  2604 
  2605 
  2606 *** HOL ***
  2607 
  2608 * Method "metis" proves goals by applying the Metis general-purpose
  2609 resolution prover (see also http://gilith.com/software/metis/).
  2610 Examples are in the directory MetisExamples.  WARNING: the
  2611 Isabelle/HOL-Metis integration does not yet work properly with
  2612 multi-threading.
  2613   
  2614 * Command 'sledgehammer' invokes external automatic theorem provers as
  2615 background processes.  It generates calls to the "metis" method if
  2616 successful. These can be pasted into the proof.  Users do not have to
  2617 wait for the automatic provers to return.  WARNING: does not really
  2618 work with multi-threading.
  2619 
  2620 * New "auto_quickcheck" feature tests outermost goal statements for
  2621 potential counter-examples.  Controlled by ML references
  2622 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2623 5000 milliseconds).  Fails silently if statements is outside of
  2624 executable fragment, or any other codgenerator problem occurs.
  2625 
  2626 * New constant "undefined" with axiom "undefined x = undefined".
  2627 
  2628 * Added class "HOL.eq", allowing for code generation with polymorphic
  2629 equality.
  2630 
  2631 * Some renaming of class constants due to canonical name prefixing in
  2632 the new 'class' package:
  2633 
  2634     HOL.abs ~> HOL.abs_class.abs
  2635     HOL.divide ~> HOL.divide_class.divide
  2636     0 ~> HOL.zero_class.zero
  2637     1 ~> HOL.one_class.one
  2638     op + ~> HOL.plus_class.plus
  2639     op - ~> HOL.minus_class.minus
  2640     uminus ~> HOL.minus_class.uminus
  2641     op * ~> HOL.times_class.times
  2642     op < ~> HOL.ord_class.less
  2643     op <= > HOL.ord_class.less_eq
  2644     Nat.power ~> Power.power_class.power
  2645     Nat.size ~> Nat.size_class.size
  2646     Numeral.number_of ~> Numeral.number_class.number_of
  2647     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2648     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2649     Orderings.min ~> Orderings.ord_class.min
  2650     Orderings.max ~> Orderings.ord_class.max
  2651     Divides.op div ~> Divides.div_class.div
  2652     Divides.op mod ~> Divides.div_class.mod
  2653     Divides.op dvd ~> Divides.div_class.dvd
  2654 
  2655 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2656 
  2657 a) User-defined constants using any of the names "plus", "minus",
  2658 "times", "less" or "less_eq". The standard syntax translations for
  2659 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2660 names.
  2661 
  2662 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2663 INCOMPATIBILITY: use more specific names.
  2664 
  2665 c) Permutative equations (e.g. "a + b = b + a")
  2666 Since the change of names also changes the order of terms, permutative
  2667 rewrite rules may get applied in a different order. Experience shows
  2668 that this is rarely the case (only two adaptions in the whole Isabelle
  2669 distribution).  INCOMPATIBILITY: rewrite proofs
  2670 
  2671 d) ML code directly refering to constant names
  2672 This in general only affects hand-written proof tactics, simprocs and
  2673 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2674 Consider using @{const_name} antiquotation.
  2675 
  2676 * New class "default" with associated constant "default".
  2677 
  2678 * Function "sgn" is now overloaded and available on int, real, complex
  2679 (and other numeric types), using class "sgn".  Two possible defs of
  2680 sgn are given as equational assumptions in the classes sgn_if and
  2681 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2682 INCOMPATIBILITY.
  2683 
  2684 * Locale "partial_order" now unified with class "order" (cf. theory
  2685 Orderings), added parameter "less".  INCOMPATIBILITY.
  2686 
  2687 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2688 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2689 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2690 
  2691 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2692 changed order of proof goals in instance proofs.
  2693 
  2694 * The transitivity reasoner for partial and linear orders is set up
  2695 for classes "order" and "linorder".  Instances of the reasoner are available
  2696 in all contexts importing or interpreting the corresponding locales.
  2697 Method "order" invokes the reasoner separately; the reasoner
  2698 is also integrated with the Simplifier as a solver.  Diagnostic
  2699 command 'print_orders' shows the available instances of the reasoner
  2700 in the current context.
  2701 
  2702 * Localized monotonicity predicate in theory "Orderings"; integrated
  2703 lemmas max_of_mono and min_of_mono with this predicate.
  2704 INCOMPATIBILITY.
  2705 
  2706 * Formulation of theorem "dense" changed slightly due to integration
  2707 with new class dense_linear_order.
  2708 
  2709 * Uniform lattice theory development in HOL.
  2710 
  2711     constants "meet" and "join" now named "inf" and "sup"
  2712     constant "Meet" now named "Inf"
  2713 
  2714     classes "meet_semilorder" and "join_semilorder" now named
  2715       "lower_semilattice" and "upper_semilattice"
  2716     class "lorder" now named "lattice"
  2717     class "comp_lat" now named "complete_lattice"
  2718 
  2719     Instantiation of lattice classes allows explicit definitions
  2720     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2721 
  2722   INCOMPATIBILITY.  Theorem renames:
  2723 
  2724     meet_left_le            ~> inf_le1
  2725     meet_right_le           ~> inf_le2
  2726     join_left_le            ~> sup_ge1
  2727     join_right_le           ~> sup_ge2
  2728     meet_join_le            ~> inf_sup_ord
  2729     le_meetI                ~> le_infI
  2730     join_leI                ~> le_supI
  2731     le_meet                 ~> le_inf_iff
  2732     le_join                 ~> ge_sup_conv
  2733     meet_idempotent         ~> inf_idem
  2734     join_idempotent         ~> sup_idem
  2735     meet_comm               ~> inf_commute
  2736     join_comm               ~> sup_commute
  2737     meet_leI1               ~> le_infI1
  2738     meet_leI2               ~> le_infI2
  2739     le_joinI1               ~> le_supI1
  2740     le_joinI2               ~> le_supI2
  2741     meet_assoc              ~> inf_assoc
  2742     join_assoc              ~> sup_assoc
  2743     meet_left_comm          ~> inf_left_commute
  2744     meet_left_idempotent    ~> inf_left_idem
  2745     join_left_comm          ~> sup_left_commute
  2746     join_left_idempotent    ~> sup_left_idem
  2747     meet_aci                ~> inf_aci
  2748     join_aci                ~> sup_aci
  2749     le_def_meet             ~> le_iff_inf
  2750     le_def_join             ~> le_iff_sup
  2751     join_absorp2            ~> sup_absorb2
  2752     join_absorp1            ~> sup_absorb1
  2753     meet_absorp1            ~> inf_absorb1
  2754     meet_absorp2            ~> inf_absorb2
  2755     meet_join_absorp        ~> inf_sup_absorb
  2756     join_meet_absorp        ~> sup_inf_absorb
  2757     distrib_join_le         ~> distrib_sup_le
  2758     distrib_meet_le         ~> distrib_inf_le
  2759 
  2760     add_meet_distrib_left   ~> add_inf_distrib_left
  2761     add_join_distrib_left   ~> add_sup_distrib_left
  2762     is_join_neg_meet        ~> is_join_neg_inf
  2763     is_meet_neg_join        ~> is_meet_neg_sup
  2764     add_meet_distrib_right  ~> add_inf_distrib_right
  2765     add_join_distrib_right  ~> add_sup_distrib_right
  2766     add_meet_join_distribs  ~> add_sup_inf_distribs
  2767     join_eq_neg_meet        ~> sup_eq_neg_inf
  2768     meet_eq_neg_join        ~> inf_eq_neg_sup
  2769     add_eq_meet_join        ~> add_eq_inf_sup
  2770     meet_0_imp_0            ~> inf_0_imp_0
  2771     join_0_imp_0            ~> sup_0_imp_0
  2772     meet_0_eq_0             ~> inf_0_eq_0
  2773     join_0_eq_0             ~> sup_0_eq_0
  2774     neg_meet_eq_join        ~> neg_inf_eq_sup
  2775     neg_join_eq_meet        ~> neg_sup_eq_inf
  2776     join_eq_if              ~> sup_eq_if
  2777 
  2778     mono_meet               ~> mono_inf
  2779     mono_join               ~> mono_sup
  2780     meet_bool_eq            ~> inf_bool_eq
  2781     join_bool_eq            ~> sup_bool_eq
  2782     meet_fun_eq             ~> inf_fun_eq
  2783     join_fun_eq             ~> sup_fun_eq
  2784     meet_set_eq             ~> inf_set_eq
  2785     join_set_eq             ~> sup_set_eq
  2786     meet1_iff               ~> inf1_iff
  2787     meet2_iff               ~> inf2_iff
  2788     meet1I                  ~> inf1I
  2789     meet2I                  ~> inf2I
  2790     meet1D1                 ~> inf1D1
  2791     meet2D1                 ~> inf2D1
  2792     meet1D2                 ~> inf1D2
  2793     meet2D2                 ~> inf2D2
  2794     meet1E                  ~> inf1E
  2795     meet2E                  ~> inf2E
  2796     join1_iff               ~> sup1_iff
  2797     join2_iff               ~> sup2_iff
  2798     join1I1                 ~> sup1I1
  2799     join2I1                 ~> sup2I1
  2800     join1I1                 ~> sup1I1
  2801     join2I2                 ~> sup1I2
  2802     join1CI                 ~> sup1CI
  2803     join2CI                 ~> sup2CI
  2804     join1E                  ~> sup1E
  2805     join2E                  ~> sup2E
  2806 
  2807     is_meet_Meet            ~> is_meet_Inf
  2808     Meet_bool_def           ~> Inf_bool_def
  2809     Meet_fun_def            ~> Inf_fun_def
  2810     Meet_greatest           ~> Inf_greatest
  2811     Meet_lower              ~> Inf_lower
  2812     Meet_set_def            ~> Inf_set_def
  2813 
  2814     Sup_def                 ~> Sup_Inf
  2815     Sup_bool_eq             ~> Sup_bool_def
  2816     Sup_fun_eq              ~> Sup_fun_def
  2817     Sup_set_eq              ~> Sup_set_def
  2818 
  2819     listsp_meetI            ~> listsp_infI
  2820     listsp_meet_eq          ~> listsp_inf_eq
  2821 
  2822     meet_min                ~> inf_min
  2823     join_max                ~> sup_max
  2824 
  2825 * Added syntactic class "size"; overloaded constant "size" now has
  2826 type "'a::size ==> bool"
  2827 
  2828 * Internal reorganisation of `size' of datatypes: size theorems
  2829 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2830 simplification rules by default!); theorems "prod.size" now named
  2831 "*.size".
  2832 
  2833 * Class "div" now inherits from class "times" rather than "type".
  2834 INCOMPATIBILITY.
  2835 
  2836 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2837 Linorder etc.  have disappeared; operations defined in terms of
  2838 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2839 
  2840 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2841 
  2842 * HOL-Word: New extensive library and type for generic, fixed size
  2843 machine words, with arithemtic, bit-wise, shifting and rotating
  2844 operations, reflection into int, nat, and bool lists, automation for
  2845 linear arithmetic (by automatic reflection into nat or int), including
  2846 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2847 arithmetic type classes, supporting automatic simplification of
  2848 numerals on all operations.
  2849 
  2850 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2851 
  2852 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2853 
  2854 * Code generator library theories:
  2855   - Code_Integer represents HOL integers by big integer literals in target
  2856     languages.
  2857   - Code_Char represents HOL characters by character literals in target
  2858     languages.
  2859   - Code_Char_chr like Code_Char, but also offers treatment of character
  2860     codes; includes Code_Integer.
  2861   - Executable_Set allows to generate code for finite sets using lists.
  2862   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2863     denominator).
  2864   - Executable_Real implements a subset of real numbers, namly those
  2865     representable by rational numbers.
  2866   - Efficient_Nat implements natural numbers by integers, which in general will
  2867     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2868     includes Code_Integer.
  2869   - Code_Index provides an additional datatype index which is mapped to
  2870     target-language built-in integers.
  2871   - Code_Message provides an additional datatype message_string which is isomorphic to
  2872     strings; messages are mapped to target-language strings.
  2873 
  2874 * New package for inductive predicates
  2875 
  2876   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2877 
  2878     inductive
  2879       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2880       for z_1 :: U_1 and ... and z_n :: U_m
  2881     where
  2882       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2883     | ...
  2884 
  2885   with full support for type-inference, rather than
  2886 
  2887     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2888 
  2889     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2890     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2891 
  2892     inductive "s z_1 ... z_m"
  2893     intros
  2894       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2895       ...
  2896 
  2897   For backward compatibility, there is a wrapper allowing inductive
  2898   sets to be defined with the new package via
  2899 
  2900     inductive_set
  2901       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2902       for z_1 :: U_1 and ... and z_n :: U_m
  2903     where
  2904       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2905     | ...
  2906 
  2907   or
  2908 
  2909     inductive_set
  2910       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2911       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2912       for z_1 :: U_1 and ... and z_n :: U_m
  2913     where
  2914       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2915     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2916     | ...
  2917 
  2918   if the additional syntax "p ..." is required.
  2919 
  2920   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2921   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2922 
  2923   INCOMPATIBILITIES:
  2924 
  2925   - Since declaration and definition of inductive sets or predicates
  2926     is no longer separated, abbreviations involving the newly
  2927     introduced sets or predicates must be specified together with the
  2928     introduction rules after the 'where' keyword (see above), rather
  2929     than before the actual inductive definition.
  2930 
  2931   - The variables in induction and elimination rules are now
  2932     quantified in the order of their occurrence in the introduction
  2933     rules, rather than in alphabetical order. Since this may break
  2934     some proofs, these proofs either have to be repaired, e.g. by
  2935     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2936     statements of the form
  2937 
  2938       case (rule_i a_i_1 ... a_i_{k_i})
  2939 
  2940     or the old order of quantification has to be restored by explicitly adding
  2941     meta-level quantifiers in the introduction rules, i.e.
  2942 
  2943       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2944 
  2945   - The format of the elimination rules is now
  2946 
  2947       p z_1 ... z_m x_1 ... x_n ==>
  2948         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2949         ==> ... ==> P
  2950 
  2951     for predicates and
  2952 
  2953       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2954         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2955         ==> ... ==> P
  2956 
  2957     for sets rather than
  2958 
  2959       x : s z_1 ... z_m ==>
  2960         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2961         ==> ... ==> P
  2962 
  2963     This may require terms in goals to be expanded to n-tuples
  2964     (e.g. using case_tac or simplification with the split_paired_all
  2965     rule) before the above elimination rule is applicable.
  2966 
  2967   - The elimination or case analysis rules for (mutually) inductive
  2968     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2969     list of rules "p_1_..._p_k.elims" is no longer available.
  2970 
  2971 * New package "function"/"fun" for general recursive functions,
  2972 supporting mutual and nested recursion, definitions in local contexts,
  2973 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2974 for small examples, and the separate tutorial on the function
  2975 package. The old recdef "package" is still available as before, but
  2976 users are encouraged to use the new package.
  2977 
  2978 * Method "lexicographic_order" automatically synthesizes termination
  2979 relations as lexicographic combinations of size measures. 
  2980 
  2981 * Case-expressions allow arbitrary constructor-patterns (including
  2982 "_") and take their order into account, like in functional
  2983 programming.  Internally, this is translated into nested
  2984 case-expressions; missing cases are added and mapped to the predefined
  2985 constant "undefined". In complicated cases printing may no longer show
  2986 the original input but the internal form. Lambda-abstractions allow
  2987 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2988 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2989 variable.
  2990 
  2991 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2992 is an abbreviation for "of_nat :: nat => int". The simplification
  2993 rules for "of_nat" have been changed to work like "int" did
  2994 previously.  Potential INCOMPATIBILITY:
  2995   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2996   - of_nat_diff and of_nat_mult are no longer default simp rules
  2997 
  2998 * Method "algebra" solves polynomial equations over (semi)rings using
  2999 Groebner bases. The (semi)ring structure is defined by locales and the
  3000 tool setup depends on that generic context. Installing the method for
  3001 a specific type involves instantiating the locale and possibly adding
  3002 declarations for computation on the coefficients.  The method is
  3003 already instantiated for natural numbers and for the axiomatic class
  3004 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3005 CALCULEMUS 2007 for the general principles underlying this
  3006 architecture of context-aware proof-tools.
  3007 
  3008 * Method "ferrack" implements quantifier elimination over
  3009 special-purpose dense linear orders using locales (analogous to
  3010 "algebra"). The method is already installed for class
  3011 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3012 rat, etc.
  3013 
  3014 * Former constant "List.op @" now named "List.append".  Use ML
  3015 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3016 circumvent possible incompatibilities when working on ML level.
  3017 
  3018 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3019 
  3020 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3021 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3022 
  3023 * New syntax for Haskell-like list comprehension (input only), eg.
  3024 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3025 
  3026 * The special syntax for function "filter" has changed from [x :
  3027 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3028 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3029 
  3030 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3031 defined on nat only, as an abbreviation for [a..<Suc b]
  3032 INCOMPATIBILITY.
  3033 
  3034 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3035 
  3036 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3037 
  3038 * New lemma collection field_simps (an extension of ring_simps) for
  3039 manipulating (in)equations involving division. Multiplies with all
  3040 denominators that can be proved to be non-zero (in equations) or
  3041 positive/negative (in inequations).
  3042 
  3043 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3044 have been improved and renamed to ring_simps, group_simps and
  3045 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3046 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3047 
  3048 * Theory Library/Commutative_Ring: switched from recdef to function
  3049 package; constants add, mul, pow now curried.  Infix syntax for
  3050 algebraic operations.
  3051 
  3052 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3053 INCOMPATIBILITY.
  3054 
  3055 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3056 INCOMPATIBILITY.
  3057 
  3058 * HOL/records: generalised field-update to take a function on the
  3059 field rather than the new value: r(|A := x|) is translated to A_update
  3060 (K x) r The K-combinator that is internally used is called K_record.
  3061 INCOMPATIBILITY: Usage of the plain update functions has to be
  3062 adapted.
  3063  
  3064 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3065 * x = 0, which are required for a semiring.  Richer structures do not
  3066 inherit from semiring_0 anymore, because this property is a theorem
  3067 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3068 there is more to prove, but this is mostly trivial.
  3069 
  3070 * Class "recpower" is generalized to arbitrary monoids, not just
  3071 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3072 commutativity or semiring properties additionally.
  3073 
  3074 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3075 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3076 better use 'abbreviation'.
  3077 
  3078 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3079 
  3080 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3081 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3082 significant changes for setting up numeral syntax for types:
  3083   - New constants Numeral.pred and Numeral.succ instead
  3084       of former Numeral.bin_pred and Numeral.bin_succ.
  3085   - Use integer operations instead of bin_add, bin_mult and so on.
  3086   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3087   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3088 
  3089 See src/HOL/Integ/IntArith.thy for an example setup.
  3090 
  3091 * Command 'normal_form' computes the normal form of a term that may
  3092 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3093 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3094 heavy-duty computations because the functions are compiled to ML
  3095 first.  Correspondingly, a method "normalization" is provided.  See
  3096 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3097 
  3098 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3099 25 like -->); output depends on the "iff" print_mode, the default is
  3100 "A = B" (with priority 50).
  3101 
  3102 * Relations less (<) and less_eq (<=) are also available on type bool.
  3103 Modified syntax to disallow nesting without explicit parentheses,
  3104 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3105 INCOMPATIBILITY.
  3106 
  3107 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3108 
  3109 * Relation composition operator "op O" now has precedence 75 and binds
  3110 stronger than union and intersection. INCOMPATIBILITY.
  3111 
  3112 * The old set interval syntax "{m..n(}" (and relatives) has been
  3113 removed.  Use "{m..<n}" (and relatives) instead.
  3114 
  3115 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3116 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3117 ``declare [[simproc del: neq]]''.
  3118 
  3119 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3120 True/False.
  3121 
  3122 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3123 
  3124 * Theorem setsum_mult renamed to setsum_right_distrib.
  3125 
  3126 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3127 ``rule'' method.
  3128 
  3129 * Reimplemented methods "sat" and "satx", with several improvements:
  3130 goals no longer need to be stated as "<prems> ==> False", equivalences
  3131 (i.e. "=" on type bool) are handled, variable names of the form
  3132 "lit_<n>" are no longer reserved, significant speedup.
  3133 
  3134 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3135 zChaff is still supported as well.
  3136 
  3137 * 'inductive' and 'datatype': provide projections of mutual rules,
  3138 bundled as foo_bar.inducts;
  3139 
  3140 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3141 Library.
  3142 
  3143 * Library: moved theory Accessible_Part to main HOL.
  3144 
  3145 * Library: added theory Coinductive_List of potentially infinite lists
  3146 as greatest fixed-point.
  3147 
  3148 * Library: added theory AssocList which implements (finite) maps as
  3149 association lists.
  3150 
  3151 * Method "evaluation" solves goals (i.e. a boolean expression)
  3152 efficiently by compiling it to ML.  The goal is "proved" (via an
  3153 oracle) if it evaluates to True.
  3154 
  3155 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3156 also when invoked by the simplifier.  This results in the Simplifier
  3157 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3158 Configuration option fast_arith_split_limit=0 recovers the old
  3159 behavior.
  3160 
  3161 * Support for hex (0x20) and binary (0b1001) numerals.
  3162 
  3163 * New method: reify eqs (t), where eqs are equations for an
  3164 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3165 parameter, computes a term s::'b and a list xs::'a list and proves the
  3166 theorem I xs s = t. This is also known as reification or quoting. The
  3167 resulting theorem is applied to the subgoal to substitute t with I xs
  3168 s.  If t is omitted, the subgoal itself is reified.
  3169 
  3170 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3171 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3172 where f is supposed to be a computable function (in the sense of code
  3173 generattion). The method uses reify to compute s and xs as above then
  3174 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3175 r and finally gets the theorem t = r, which is again applied to the
  3176 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3177 
  3178 * Reflection: Automatic reification now handels binding, an example is
  3179 available in src/HOL/ex/ReflectionEx.thy
  3180 
  3181 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3182 command 'statespace' that is similar to 'record', but introduces an
  3183 abstract specification based on the locale infrastructure instead of
  3184 HOL types.  This leads to extra flexibility in composing state spaces,
  3185 in particular multiple inheritance and renaming of components.
  3186 
  3187 
  3188 *** HOL-Complex ***
  3189 
  3190 * Hyperreal: Functions root and sqrt are now defined on negative real
  3191 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3192 Nonnegativity side conditions have been removed from many lemmas, so
  3193 that more subgoals may now be solved by simplification; potential
  3194 INCOMPATIBILITY.
  3195 
  3196 * Real: new type classes formalize real normed vector spaces and
  3197 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3198 and norm :: 'a => real.
  3199 
  3200 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3201 reals into other types. The overloaded constant Reals :: 'a set is now
  3202 defined as range of_real; potential INCOMPATIBILITY.
  3203 
  3204 * Real: proper support for ML code generation, including 'quickcheck'.
  3205 Reals are implemented as arbitrary precision rationals.
  3206 
  3207 * Hyperreal: Several constants that previously worked only for the
  3208 reals have been generalized, so they now work over arbitrary vector
  3209 spaces. Type annotations may need to be added in some cases; potential
  3210 INCOMPATIBILITY.
  3211 
  3212   Infinitesimal  :: ('a::real_normed_vector) star set
  3213   HFinite        :: ('a::real_normed_vector) star set
  3214   HInfinite      :: ('a::real_normed_vector) star set
  3215   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3216   monad          :: ('a::real_normed_vector) star => 'a star set
  3217   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3218   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3219   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3220   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3221   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3222   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3223   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3224   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3225   sgn            :: 'a::real_normed_vector => 'a
  3226   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3227 
  3228 * Complex: Some complex-specific constants are now abbreviations for
  3229 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3230 hnorm.  Other constants have been entirely removed in favor of the
  3231 polymorphic versions (INCOMPATIBILITY):
  3232 
  3233   approx        <-- capprox
  3234   HFinite       <-- CFinite
  3235   HInfinite     <-- CInfinite
  3236   Infinitesimal <-- CInfinitesimal
  3237   monad         <-- cmonad
  3238   galaxy        <-- cgalaxy
  3239   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3240   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3241   (ns)deriv     <-- (ns)cderiv
  3242 
  3243 
  3244 *** HOL-Algebra ***
  3245 
  3246 * Formalisation of ideals and the quotient construction over rings.
  3247 
  3248 * Order and lattice theory no longer based on records.
  3249 INCOMPATIBILITY.
  3250 
  3251 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3252 greatest_closed.  INCOMPATIBILITY.
  3253 
  3254 * Method algebra is now set up via an attribute.  For examples see
  3255 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3256 of algebraic structures.
  3257 
  3258 * Renamed theory CRing to Ring.
  3259 
  3260 
  3261 *** HOL-Nominal ***
  3262 
  3263 * Substantial, yet incomplete support for nominal datatypes (binding
  3264 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3265 src/HOL/Nominal/Examples.  Prospective users should consult
  3266 http://isabelle.in.tum.de/nominal/
  3267 
  3268 
  3269 *** ML ***
  3270 
  3271 * ML basics: just one true type int, which coincides with IntInf.int
  3272 (even on SML/NJ).
  3273 
  3274 * ML within Isar: antiquotations allow to embed statically-checked
  3275 formal entities in the source, referring to the context available at
  3276 compile-time.  For example:
  3277 
  3278 ML {* @{sort "{zero,one}"} *}
  3279 ML {* @{typ "'a => 'b"} *}
  3280 ML {* @{term "%x. x"} *}
  3281 ML {* @{prop "x == y"} *}
  3282 ML {* @{ctyp "'a => 'b"} *}
  3283 ML {* @{cterm "%x. x"} *}
  3284 ML {* @{cprop "x == y"} *}
  3285 ML {* @{thm asm_rl} *}
  3286 ML {* @{thms asm_rl} *}
  3287 ML {* @{type_name c} *}
  3288 ML {* @{type_syntax c} *}
  3289 ML {* @{const_name c} *}
  3290 ML {* @{const_syntax c} *}
  3291 ML {* @{context} *}
  3292 ML {* @{theory} *}
  3293 ML {* @{theory Pure} *}
  3294 ML {* @{theory_ref} *}
  3295 ML {* @{theory_ref Pure} *}
  3296 ML {* @{simpset} *}
  3297 ML {* @{claset} *}
  3298 ML {* @{clasimpset} *}
  3299 
  3300 The same works for sources being ``used'' within an Isar context.
  3301 
  3302 * ML in Isar: improved error reporting; extra verbosity with
  3303 ML_Context.trace enabled.
  3304 
  3305 * Pure/General/table.ML: the join operations now works via exceptions
  3306 DUP/SAME instead of type option. This is simpler in simple cases, and
  3307 admits slightly more efficient complex applications.
  3308 
  3309 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3310 use Context.generic instead of just theory.
  3311 
  3312 * Pure: datatype Context.generic joins theory/Proof.context and
  3313 provides some facilities for code that works in either kind of
  3314 context, notably GenericDataFun for uniform theory and proof data.
  3315 
  3316 * Pure: simplified internal attribute type, which is now always
  3317 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3318 local (Proof.context) attributes have been discontinued, while
  3319 minimizing code duplication. Thm.rule_attribute and
  3320 Thm.declaration_attribute build canonical attributes; see also structure
  3321 Context for further operations on Context.generic, notably
  3322 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3323 declarations and definitions.
  3324 
  3325 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3326 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3327 init only required for impure data. INCOMPATIBILITY: empty really need
  3328 to be empty (no dependencies on theory content!)
  3329 
  3330 * Pure/kernel: consts certification ignores sort constraints given in
  3331 signature declarations. (This information is not relevant to the
  3332 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3333 potential INCOMPATIBILITY.
  3334 
  3335 * Pure: axiomatic type classes are now purely definitional, with
  3336 explicit proofs of class axioms and super class relations performed
  3337 internally. See Pure/axclass.ML for the main internal interfaces --
  3338 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3339 AxClass.axiomatize_class/classrel/arity supersede
  3340 Sign.add_classes/classrel/arities.
  3341 
  3342 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3343 global/local versions on theory vs. Proof.context have been
  3344 discontinued; Attrib.syntax and Method.syntax have been adapted
  3345 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3346 attributes, methods, etc.
  3347 
  3348 * Pure: several functions of signature "... -> theory -> theory * ..."
  3349 have been reoriented to "... -> theory -> ... * theory" in order to
  3350 allow natural usage in combination with the ||>, ||>>, |-> and
  3351 fold_map combinators.
  3352 
  3353 * Pure: official theorem names (closed derivations) and additional
  3354 comments (tags) are now strictly separate.  Name hints -- which are
  3355 maintained as tags -- may be attached any time without affecting the
  3356 derivation.
  3357 
  3358 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3359 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3360 achieve the old behaviour.
  3361 
  3362 * Pure: the "Goal" constant is now called "prop", supporting a
  3363 slightly more general idea of ``protecting'' meta-level rule
  3364 statements.
  3365 
  3366 * Pure: Logic.(un)varify only works in a global context, which is now
  3367 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3368 Logic.legacy_(un)varify as temporary workaround.
  3369 
  3370 * Pure: structure Name provides scalable operations for generating
  3371 internal variable names, notably Name.variants etc.  This replaces
  3372 some popular functions from term.ML:
  3373 
  3374   Term.variant		->  Name.variant
  3375   Term.variantlist	->  Name.variant_list
  3376   Term.invent_names	->  Name.invent_list
  3377 
  3378 Note that low-level renaming rarely occurs in new code -- operations
  3379 from structure Variable are used instead (see below).
  3380 
  3381 * Pure: structure Variable provides fundamental operations for proper
  3382 treatment of fixed/schematic variables in a context.  For example,
  3383 Variable.import introduces fixes for schematics of given facts and
  3384 Variable.export reverses the effect (up to renaming) -- this replaces
  3385 various freeze_thaw operations.
  3386 
  3387 * Pure: structure Goal provides simple interfaces for
  3388 init/conclude/finish and tactical prove operations (replacing former
  3389 Tactic.prove).  Goal.prove is the canonical way to prove results
  3390 within a given context; Goal.prove_global is a degraded version for
  3391 theory level goals, including a global Drule.standard.  Note that
  3392 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3393 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3394 in a locale context).
  3395 
  3396 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3397 and type checking (Syntax.check_term etc.), with common combinations
  3398 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3399 which are considered legacy and await removal.
  3400 
  3401 * Pure/Syntax: generic interfaces for type unchecking
  3402 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3403 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3404 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3405 available for convenience, but refer to the very same operations using
  3406 a mere theory instead of a full context.
  3407 
  3408 * Isar: simplified treatment of user-level errors, using exception
  3409 ERROR of string uniformly.  Function error now merely raises ERROR,
  3410 without any side effect on output channels.  The Isar toplevel takes
  3411 care of proper display of ERROR exceptions.  ML code may use plain
  3412 handle/can/try; cat_error may be used to concatenate errors like this:
  3413 
  3414   ... handle ERROR msg => cat_error msg "..."
  3415 
  3416 Toplevel ML code (run directly or through the Isar toplevel) may be
  3417 embedded into the Isar toplevel with exception display/debug like
  3418 this:
  3419 
  3420   Isar.toplevel (fn () => ...)
  3421 
  3422 INCOMPATIBILITY, removed special transform_error facilities, removed
  3423 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3424 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3425 -- use plain ERROR instead.
  3426 
  3427 * Isar: theory setup now has type (theory -> theory), instead of a
  3428 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3429 
  3430 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3431 ProofContext.debug/verbose flags.
  3432 
  3433 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3434 theory before entering a proof state.  Transactions now always see a
  3435 quasi-functional intermediate checkpoint, both in interactive and
  3436 batch mode.
  3437 
  3438 * Isar: simplified interfaces for outer syntax.  Renamed
  3439 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3440 OuterSyntax.add_parsers -- this functionality is now included in
  3441 OuterSyntax.command etc.  INCOMPATIBILITY.
  3442 
  3443 * Simplifier: the simpset of a running simplification process now
  3444 contains a proof context (cf. Simplifier.the_context), which is the
  3445 very context that the initial simpset has been retrieved from (by
  3446 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3447 (solver, looper etc.) may depend on arbitrary proof data.
  3448 
  3449 * Simplifier.inherit_context inherits the proof context (plus the
  3450 local bounds) of the current simplification process; any simproc
  3451 etc. that calls the Simplifier recursively should do this!  Removed
  3452 former Simplifier.inherit_bounds, which is already included here --
  3453 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3454 specify an explicit context using Simplifier.context/theory_context.
  3455 
  3456 * Simplifier/Classical Reasoner: more abstract interfaces
  3457 change_simpset/claset for modifying the simpset/claset reference of a
  3458 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3459 INCOMPATIBILITY.
  3460 
  3461 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3462 "Trueprop" etc.
  3463 
  3464 
  3465 *** System ***
  3466 
  3467 * settings: the default heap location within ISABELLE_HOME_USER now
  3468 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3469 Isabelle installations.
  3470 
  3471 * isabelle-process: option -S (secure mode) disables some critical
  3472 operations, notably runtime compilation and evaluation of ML source
  3473 code.
  3474 
  3475 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3476 
  3477 * Support for parallel execution, using native multicore support of
  3478 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3479 independent theories, according to the given theory header
  3480 specifications. The maximum number of worker threads is specified via
  3481 usedir option -M or the "max-threads" setting in Proof General. A
  3482 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3483 to 6 on a 8-core machine.  User-code needs to observe certain
  3484 guidelines for thread-safe programming, see appendix A in the Isar
  3485 Implementation manual.
  3486 
  3487 
  3488 
  3489 New in Isabelle2005 (October 2005)
  3490 ----------------------------------
  3491 
  3492 *** General ***
  3493 
  3494 * Theory headers: the new header syntax for Isar theories is
  3495 
  3496   theory <name>
  3497   imports <theory1> ... <theoryN>
  3498   uses <file1> ... <fileM>
  3499   begin
  3500 
  3501 where the 'uses' part is optional.  The previous syntax
  3502 
  3503   theory <name> = <theory1> + ... + <theoryN>:
  3504 
  3505 will disappear in the next release.  Use isatool fixheaders to convert
  3506 existing theory files.  Note that there is no change in ancient
  3507 non-Isar theories now, but these will disappear soon.
  3508 
  3509 * Theory loader: parent theories can now also be referred to via
  3510 relative and absolute paths.
  3511 
  3512 * Command 'find_theorems' searches for a list of criteria instead of a
  3513 list of constants. Known criteria are: intro, elim, dest, name:string,
  3514 simp:term, and any term. Criteria can be preceded by '-' to select
  3515 theorems that do not match. Intro, elim, dest select theorems that
  3516 match the current goal, name:s selects theorems whose fully qualified
  3517 name contain s, and simp:term selects all simplification rules whose
  3518 lhs match term.  Any other term is interpreted as pattern and selects
  3519 all theorems matching the pattern. Available in ProofGeneral under
  3520 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3521 
  3522   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3523 
  3524 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3525 matching the current goal as introduction rule and not having "HOL."
  3526 in their name (i.e. not being defined in theory HOL).
  3527 
  3528 * Command 'thms_containing' has been discontinued in favour of
  3529 'find_theorems'; INCOMPATIBILITY.
  3530 
  3531 * Communication with Proof General is now 8bit clean, which means that
  3532 Unicode text in UTF-8 encoding may be used within theory texts (both
  3533 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3534 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3535 
  3536   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3537   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3538 
  3539 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3540 Classical Reasoner.  Typical big applications run around 2 times
  3541 faster.
  3542 
  3543 
  3544 *** Document preparation ***
  3545 
  3546 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3547 of raw sources.  Only those symbols that do not require additional
  3548 LaTeX packages (depending on comments in isabellesym.sty) are
  3549 displayed properly, everything else is left verbatim.  isatool display
  3550 and isatool print are used as front ends (these are subject to the
  3551 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3552 
  3553 * Command tags control specific markup of certain regions of text,
  3554 notably folding and hiding.  Predefined tags include "theory" (for
  3555 theory begin and end), "proof" for proof commands, and "ML" for
  3556 commands involving ML code; the additional tags "visible" and
  3557 "invisible" are unused by default.  Users may give explicit tag
  3558 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3559 interpretation of tags is determined by the LaTeX job during document
  3560 preparation: see option -V of isatool usedir, or options -n and -t of
  3561 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3562 \isadroptag.
  3563 
  3564 Several document versions may be produced at the same time via isatool
  3565 usedir (the generated index.html will link all of them).  Typical
  3566 specifications include ''-V document=theory,proof,ML'' to present
  3567 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3568 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3569 these parts without any formal replacement text.  The Isabelle site
  3570 default settings produce ''document'' and ''outline'' versions as
  3571 specified above.
  3572 
  3573 * Several new antiquotations:
  3574 
  3575   @{term_type term} prints a term with its type annotated;
  3576 
  3577   @{typeof term} prints the type of a term;
  3578 
  3579   @{const const} is the same as @{term const}, but checks that the
  3580   argument is a known logical constant;
  3581 
  3582   @{term_style style term} and @{thm_style style thm} print a term or
  3583   theorem applying a "style" to it
  3584 
  3585   @{ML text}
  3586 
  3587 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3588 definitions, equations, inequations etc., 'concl' printing only the
  3589 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3590 to print the specified premise.  TermStyle.add_style provides an ML
  3591 interface for introducing further styles.  See also the "LaTeX Sugar"
  3592 document practical applications.  The ML antiquotation prints
  3593 type-checked ML expressions verbatim.
  3594 
  3595 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3596 and 'text' support optional locale specification '(in loc)', which
  3597 specifies the default context for interpreting antiquotations.  For
  3598 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3599 
  3600 * Option 'locale=NAME' of antiquotations specifies an alternative
  3601 context interpreting the subsequent argument.  For example: @{thm
  3602 [locale=lattice] inf_assoc}.
  3603 
  3604 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3605 a proof context.
  3606 
  3607 * Proper output of antiquotations for theory commands involving a
  3608 proof context (such as 'locale' or 'theorem (in loc) ...').
  3609 
  3610 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3611 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3612 
  3613 * isatool usedir: new option -C (default true) controls whether option
  3614 -D should include a copy of the original document directory; -C false
  3615 prevents unwanted effects such as copying of administrative CVS data.
  3616 
  3617 
  3618 *** Pure ***
  3619 
  3620 * Considerably improved version of 'constdefs' command.  Now performs
  3621 automatic type-inference of declared constants; additional support for
  3622 local structure declarations (cf. locales and HOL records), see also
  3623 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3624 sequential dependencies of definitions within a single 'constdefs'
  3625 section; moreover, the declared name needs to be an identifier.  If
  3626 all fails, consider to fall back on 'consts' and 'defs' separately.
  3627 
  3628 * Improved indexed syntax and implicit structures.  First of all,
  3629 indexed syntax provides a notational device for subscripted
  3630 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3631 expressions.  Secondly, in a local context with structure
  3632 declarations, number indexes \<^sub>n or the empty index (default
  3633 number 1) refer to a certain fixed variable implicitly; option
  3634 show_structs controls printing of implicit structures.  Typical
  3635 applications of these concepts involve record types and locales.
  3636 
  3637 * New command 'no_syntax' removes grammar declarations (and
  3638 translations) resulting from the given syntax specification, which is
  3639 interpreted in the same manner as for the 'syntax' command.
  3640 
  3641 * 'Advanced' translation functions (parse_translation etc.) may depend
  3642 on the signature of the theory context being presently used for
  3643 parsing/printing, see also isar-ref manual.
  3644 
  3645 * Improved 'oracle' command provides a type-safe interface to turn an
  3646 ML expression of type theory -> T -> term into a primitive rule of
  3647 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3648 is already included here); see also FOL/ex/IffExample.thy;
  3649 INCOMPATIBILITY.
  3650 
  3651 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3652 before); "cI" is no longer bound, use "c.intro" instead.
  3653 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3654 axclasses vs. locales.
  3655 
  3656 * Improved internal renaming of symbolic identifiers -- attach primes
  3657 instead of base 26 numbers.
  3658 
  3659 * New flag show_question_marks controls printing of leading question
  3660 marks in schematic variable names.
  3661 
  3662 * In schematic variable names, *any* symbol following \<^isub> or
  3663 \<^isup> is now treated as part of the base name.  For example, the
  3664 following works without printing of awkward ".0" indexes:
  3665 
  3666   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3667     by simp
  3668 
  3669 * Inner syntax includes (*(*nested*) comments*).
  3670 
  3671 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3672 annotations as "(00...)".
  3673 
  3674 * Clear separation of logical types and nonterminals, where the latter
  3675 may only occur in 'syntax' specifications or type abbreviations.
  3676 Before that distinction was only partially implemented via type class
  3677 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3678 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3679 exotic syntax specifications may require further adaption
  3680 (e.g. Cube/Cube.thy).
  3681 
  3682 * Removed obsolete type class "logic", use the top sort {} instead.
  3683 Note that non-logical types should be declared as 'nonterminals'
  3684 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3685 specifications.
  3686 
  3687 * Attributes 'induct' and 'cases': type or set names may now be
  3688 locally fixed variables as well.
  3689 
  3690 * Simplifier: can now control the depth to which conditional rewriting
  3691 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3692 Limit.
  3693 
  3694 * Simplifier: simplification procedures may now take the current
  3695 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3696 interface), which is very useful for calling the Simplifier
  3697 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3698 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3699 low-level mk_simproc no longer applies Logic.varify internally, to
  3700 allow for use in a context of fixed variables.
  3701 
  3702 * thin_tac now works even if the assumption being deleted contains !!
  3703 or ==>.  More generally, erule now works even if the major premise of
  3704 the elimination rule contains !! or ==>.
  3705 
  3706 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3707 
  3708 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3709 from Pure, which contains all common declarations already.  Both
  3710 theories are defined via plain Isabelle/Isar .thy files.
  3711 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3712 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3713 use isatool fixcpure to adapt your theory and ML sources.
  3714 
  3715 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3716 selections of theorems in named facts via index ranges.
  3717 
  3718 * 'print_theorems': in theory mode, really print the difference
  3719 wrt. the last state (works for interactive theory development only),
  3720 in proof mode print all local facts (cf. 'print_facts');
  3721 
  3722 * 'hide': option '(open)' hides only base names.
  3723 
  3724 * More efficient treatment of intermediate checkpoints in interactive
  3725 theory development.
  3726 
  3727 * Code generator is now invoked via code_module (incremental code
  3728 generation) and code_library (modular code generation, ML structures
  3729 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3730 must be quoted when used as identifiers.
  3731 
  3732 * New 'value' command for reading, evaluating and printing terms using
  3733 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3734 quoted when used as identifier.
  3735 
  3736 
  3737 *** Locales ***
  3738 
  3739 * New commands for the interpretation of locale expressions in
  3740 theories (1), locales (2) and proof contexts (3).  These generate
  3741 proof obligations from the expression specification.  After the
  3742 obligations have been discharged, theorems of the expression are added
  3743 to the theory, target locale or proof context.  The synopsis of the
  3744 commands is a follows:
  3745 
  3746   (1) interpretation expr inst
  3747   (2) interpretation target < expr
  3748   (3) interpret expr inst
  3749 
  3750 Interpretation in theories and proof contexts require a parameter
  3751 instantiation of terms from the current context.  This is applied to
  3752 specifications and theorems of the interpreted expression.
  3753 Interpretation in locales only permits parameter renaming through the
  3754 locale expression.  Interpretation is smart in that interpretations
  3755 that are active already do not occur in proof obligations, neither are
  3756 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3757 inspect active interpretations of a particular locale.  For details,
  3758 see the Isar Reference manual.  Examples can be found in
  3759 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3760 
  3761 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3762 'interpret' instead.
  3763 
  3764 * New context element 'constrains' for adding type constraints to
  3765 parameters.
  3766 
  3767 * Context expressions: renaming of parameters with syntax
  3768 redeclaration.
  3769 
  3770 * Locale declaration: 'includes' disallowed.
  3771 
  3772 * Proper static binding of attribute syntax -- i.e. types / terms /
  3773 facts mentioned as arguments are always those of the locale definition
  3774 context, independently of the context of later invocations.  Moreover,
  3775 locale operations (renaming and type / term instantiation) are applied
  3776 to attribute arguments as expected.
  3777 
  3778 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3779 actual attributes; rare situations may require Attrib.attribute to
  3780 embed those attributes into Attrib.src that lack concrete syntax.
  3781 Attribute implementations need to cooperate properly with the static
  3782 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3783 Attrib.XXX_thm etc. already do the right thing without further
  3784 intervention.  Only unusual applications -- such as "where" or "of"
  3785 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3786 on the context and the facts involved -- may have to assign parsed
  3787 values to argument tokens explicitly.
  3788 
  3789 * Changed parameter management in theorem generation for long goal
  3790 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3791 theorem statement in rare situations.
  3792 
  3793 * Locale inspection command 'print_locale' omits notes elements.  Use
  3794 'print_locale!' to have them included in the output.
  3795 
  3796 
  3797 *** Provers ***
  3798 
  3799 * Provers/hypsubst.ML: improved version of the subst method, for
  3800 single-step rewriting: it now works in bound variable contexts. New is
  3801 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3802 rewrite a different subterm than the original subst method, which is
  3803 still available as 'simplesubst'.
  3804 
  3805 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3806 and quasi orders.
  3807 
  3808 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3809 reflexive-transitive closure of relations.
  3810 
  3811 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3812 limit (previously hard-coded with a value of 20) user-definable.
  3813 
  3814 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3815 is peformed already.  Object-logics merely need to finish their
  3816 initial simpset configuration as before.  INCOMPATIBILITY.
  3817 
  3818 
  3819 *** HOL ***
  3820 
  3821 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3822 
  3823   syntax (epsilon)
  3824     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3825 
  3826 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3827 and x-symbol; use option '-m epsilon' to get it actually printed.
  3828 Moreover, the mathematically important symbolic identifier \<epsilon>
  3829 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3830 
  3831 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3832 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3833 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3834 support corresponding Isar calculations.
  3835 
  3836 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3837 instead of ":".
  3838 
  3839 * theory SetInterval: changed the syntax for open intervals:
  3840 
  3841   Old       New
  3842   {..n(}    {..<n}
  3843   {)n..}    {n<..}
  3844   {m..n(}   {m..<n}
  3845   {)m..n}   {m<..n}
  3846   {)m..n(}  {m<..<n}
  3847 
  3848 The old syntax is still supported but will disappear in the next
  3849 release.  For conversion use the following Emacs search and replace
  3850 patterns (these are not perfect but work quite well):
  3851 
  3852   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3853   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3854 
  3855 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3856 equalities in commutative rings; method 'algebra' provides a generic
  3857 interface.
  3858 
  3859 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3860 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3861 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3862 be a tuple pattern.
  3863 
  3864 Some new syntax forms are available:
  3865 
  3866   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3867   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3868   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3869   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3870 
  3871 The latter form "\<Sum>x < k. e" used to be based on a separate
  3872 function "Summation", which has been discontinued.
  3873 
  3874 * theory Finite_Set: in structured induction proofs, the insert case
  3875 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3876 (insert F x)'.
  3877 
  3878 * The 'refute' command has been extended to support a much larger
  3879 fragment of HOL, including axiomatic type classes, constdefs and
  3880 typedefs, inductive datatypes and recursion.
  3881 
  3882 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3883 Requires zChaff with proof generation to be installed.  See
  3884 HOL/ex/SAT_Examples.thy for examples.
  3885 
  3886 * Datatype induction via method 'induct' now preserves the name of the
  3887 induction variable. For example, when proving P(xs::'a list) by
  3888 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3889 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3890 in unstructured proof scripts.
  3891 
  3892 * Reworked implementation of records.  Improved scalability for
  3893 records with many fields, avoiding performance problems for type
  3894 inference. Records are no longer composed of nested field types, but
  3895 of nested extension types. Therefore the record type only grows linear
  3896 in the number of extensions and not in the number of fields.  The
  3897 top-level (users) view on records is preserved.  Potential
  3898 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3899 old record representation. The type generated for a record is called
  3900 <record_name>_ext_type.
  3901 
  3902 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3903 proofs triggered by a record definition or a simproc (if
  3904 quick_and_dirty is enabled).  Definitions of large records can take
  3905 quite long.
  3906 
  3907 New simproc record_upd_simproc for simplification of multiple record
  3908 updates enabled by default.  Moreover, trivial updates are also
  3909 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3910 occasionally, since simplification is more powerful by default.
  3911 
  3912 * typedef: proper support for polymorphic sets, which contain extra
  3913 type-variables in the term.
  3914 
  3915 * Simplifier: automatically reasons about transitivity chains
  3916 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3917 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3918 old proofs break occasionally as simplification may now solve more
  3919 goals than previously.
  3920 
  3921 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3922 present.  Works for all partial orders (class "order"), in particular
  3923 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3924 just like y <= x.
  3925 
  3926 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3927 bound variable or a constant then the let is unfolded.  Otherwise
  3928 first a is simplified to b, and then f b is simplified to g. If
  3929 possible we abstract b from g arriving at "let x = b in h x",
  3930 otherwise we unfold the let and arrive at g.  The simproc can be
  3931 enabled/disabled by the reference use_let_simproc.  Potential
  3932 INCOMPATIBILITY since simplification is more powerful by default.
  3933 
  3934 * Classical reasoning: the meson method now accepts theorems as arguments.
  3935 
  3936 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3937 jobs to provide advice on the provability of subgoals.
  3938 
  3939 * Theory OrderedGroup and Ring_and_Field: various additions and
  3940 improvements to faciliate calculations involving equalities and
  3941 inequalities.
  3942 
  3943 The following theorems have been eliminated or modified
  3944 (INCOMPATIBILITY):
  3945 
  3946   abs_eq             now named abs_of_nonneg
  3947   abs_of_ge_0        now named abs_of_nonneg
  3948   abs_minus_eq       now named abs_of_nonpos
  3949   imp_abs_id         now named abs_of_nonneg
  3950   imp_abs_neg_id     now named abs_of_nonpos
  3951   mult_pos           now named mult_pos_pos
  3952   mult_pos_le        now named mult_nonneg_nonneg
  3953   mult_pos_neg_le    now named mult_nonneg_nonpos
  3954   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3955   mult_neg           now named mult_neg_neg
  3956   mult_neg_le        now named mult_nonpos_nonpos
  3957 
  3958 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3959      
  3960      zero_le_square
  3961      not_square_less_zero 
  3962 
  3963   The following lemmas have been deleted from Real/RealPow:
  3964   
  3965      realpow_zero_zero
  3966      realpow_two
  3967      realpow_less
  3968      zero_le_power
  3969      realpow_two_le
  3970      abs_realpow_two
  3971      realpow_two_abs     
  3972 
  3973 * Theory Parity: added rules for simplifying exponents.
  3974 
  3975 * Theory List:
  3976 
  3977 The following theorems have been eliminated or modified
  3978 (INCOMPATIBILITY):
  3979 
  3980   list_all_Nil       now named list_all.simps(1)
  3981   list_all_Cons      now named list_all.simps(2)
  3982   list_all_conv      now named list_all_iff
  3983   set_mem_eq         now named mem_iff
  3984 
  3985 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3986 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3987 
  3988 
  3989 *** HOL-Complex ***
  3990 
  3991 * Theory RealDef: better support for embedding natural numbers and
  3992 integers in the reals.
  3993 
  3994 The following theorems have been eliminated or modified
  3995 (INCOMPATIBILITY):
  3996 
  3997   exp_ge_add_one_self  now requires no hypotheses
  3998   real_of_int_add      reversed direction of equality (use [symmetric])
  3999   real_of_int_minus    reversed direction of equality (use [symmetric])
  4000   real_of_int_diff     reversed direction of equality (use [symmetric])
  4001   real_of_int_mult     reversed direction of equality (use [symmetric])
  4002 
  4003 * Theory RComplete: expanded support for floor and ceiling functions.
  4004 
  4005 * Theory Ln is new, with properties of the natural logarithm
  4006 
  4007 * Hyperreal: There is a new type constructor "star" for making
  4008 nonstandard types.  The old type names are now type synonyms:
  4009 
  4010   hypreal = real star
  4011   hypnat = nat star
  4012   hcomplex = complex star
  4013 
  4014 * Hyperreal: Many groups of similarly-defined constants have been
  4015 replaced by polymorphic versions (INCOMPATIBILITY):
  4016 
  4017   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4018 
  4019   starset      <-- starsetNat, starsetC
  4020   *s*          <-- *sNat*, *sc*
  4021   starset_n    <-- starsetNat_n, starsetC_n
  4022   *sn*         <-- *sNatn*, *scn*
  4023   InternalSets <-- InternalNatSets, InternalCSets
  4024 
  4025   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4026   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4027   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4028   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4029   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4030 
  4031 * Hyperreal: Many type-specific theorems have been removed in favor of
  4032 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4033 
  4034   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4035   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4036   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4037   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4038   right_minus <-- hypreal_add_minus
  4039   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4040   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4041   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4042   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4043   mult_1_right <-- hcomplex_mult_one_right
  4044   mult_zero_left <-- hcomplex_mult_zero_left
  4045   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4046   right_distrib <-- hypnat_add_mult_distrib2
  4047   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4048   right_inverse <-- hypreal_mult_inverse
  4049   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4050   order_refl <-- {hypreal,hypnat}_le_refl
  4051   order_trans <-- {hypreal,hypnat}_le_trans
  4052   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4053   order_less_le <-- {hypreal,hypnat}_less_le
  4054   linorder_linear <-- {hypreal,hypnat}_le_linear
  4055   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4056   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4057   add_nonneg_nonneg <-- hypreal_le_add_order
  4058 
  4059 * Hyperreal: Separate theorems having to do with type-specific
  4060 versions of constants have been merged into theorems that apply to the
  4061 new polymorphic constants (INCOMPATIBILITY):
  4062 
  4063   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4064   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4065   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4066   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4067   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4068   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4069   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4070   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4071   STAR_diff <-- {STAR,STARC}_diff
  4072   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4073     STARC_hcomplex_of_complex}_image_subset
  4074   starset_n_Un <-- starset{Nat,C}_n_Un
  4075   starset_n_Int <-- starset{Nat,C}_n_Int
  4076   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4077   starset_n_diff <-- starset{Nat,C}_n_diff
  4078   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4079   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4080   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4081   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4082   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4083   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4084   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4085   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4086   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4087   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4088   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4089   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4090   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4091   starfun_diff <-- starfun{C,RC,CR}_diff
  4092   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4093   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4094   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4095   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4096   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4097   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4098   starfun_Id <-- starfunC_Id
  4099   starfun_approx <-- starfun{Nat,CR}_approx
  4100   starfun_capprox <-- starfun{C,RC}_capprox
  4101   starfun_abs <-- starfunNat_rabs
  4102   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4103   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4104   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4105   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4106   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4107   starfun_add_approx <-- starfunCR_add_approx
  4108   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4109   starfun_divide <-- starfun{C,CR,RC}_divide
  4110   starfun_n <-- starfun{Nat,C}_n
  4111   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4112   starfun_n_add <-- starfun{Nat,C}_n_add
  4113   starfun_n_add_minus <-- starfunNat_n_add_minus
  4114   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4115   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4116   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4117 
  4118   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4119   star_n_minus <-- {hypreal,hcomplex}_minus
  4120   star_n_diff <-- {hypreal,hcomplex}_diff
  4121   star_n_mult <-- {hypreal,hcomplex}_mult
  4122   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4123   star_n_le <-- {hypreal,hypnat}_le
  4124   star_n_less <-- {hypreal,hypnat}_less
  4125   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4126   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4127   star_n_abs <-- hypreal_hrabs
  4128   star_n_divide <-- hcomplex_divide
  4129 
  4130   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4131   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4132   star_of_diff <-- hypreal_of_real_diff
  4133   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4134   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4135   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4136   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4137   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4138   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4139   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4140   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4141   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4142   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4143   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4144   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4145   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4146   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4147   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4148   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4149   star_of_power <-- hypreal_of_real_power
  4150   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4151 
  4152 * Hyperreal: new method "transfer" that implements the transfer
  4153 principle of nonstandard analysis. With a subgoal that mentions
  4154 nonstandard types like "'a star", the command "apply transfer"
  4155 replaces it with an equivalent one that mentions only standard types.
  4156 To be successful, all free variables must have standard types; non-
  4157 standard variables must have explicit universal quantifiers.
  4158 
  4159 * Hyperreal: A theory of Taylor series.
  4160 
  4161 
  4162 *** HOLCF ***
  4163 
  4164 * Discontinued special version of 'constdefs' (which used to support
  4165 continuous functions) in favor of the general Pure one with full
  4166 type-inference.
  4167 
  4168 * New simplification procedure for solving continuity conditions; it
  4169 is much faster on terms with many nested lambda abstractions (cubic
  4170 instead of exponential time).
  4171 
  4172 * New syntax for domain package: selector names are now optional.
  4173 Parentheses should be omitted unless argument is lazy, for example:
  4174 
  4175   domain 'a stream = cons "'a" (lazy "'a stream")
  4176 
  4177 * New command 'fixrec' for defining recursive functions with pattern
  4178 matching; defining multiple functions with mutual recursion is also
  4179 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4180 sinr, or any data constructor defined by the domain package. The given
  4181 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4182 syntax and examples.
  4183 
  4184 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4185 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4186 but the proof obligation additionally includes an admissibility
  4187 requirement. The packages generate instances of class cpo or pcpo,
  4188 with continuity and strictness theorems for Rep and Abs.
  4189 
  4190 * HOLCF: Many theorems have been renamed according to a more standard naming
  4191 scheme (INCOMPATIBILITY):
  4192 
  4193   foo_inject:  "foo$x = foo$y ==> x = y"
  4194   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4195   foo_less:    "(foo$x << foo$y) = (x << y)"
  4196   foo_strict:  "foo$UU = UU"
  4197   foo_defined: "... ==> foo$x ~= UU"
  4198   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4199 
  4200 
  4201 *** ZF ***
  4202 
  4203 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4204 including the First Isomorphism Theorem (on quotienting by the kernel
  4205 of a homomorphism).
  4206 
  4207 * ZF/Simplifier: install second copy of type solver that actually
  4208 makes use of TC rules declared to Isar proof contexts (or locales);
  4209 the old version is still required for ML proof scripts.
  4210 
  4211 
  4212 *** Cube ***
  4213 
  4214 * Converted to Isar theory format; use locales instead of axiomatic
  4215 theories.
  4216 
  4217 
  4218 *** ML ***
  4219 
  4220 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4221 for ||>, ||>>, |>>,
  4222 
  4223 * Pure/library.ML no longer defines its own option datatype, but uses
  4224 that of the SML basis, which has constructors NONE and SOME instead of
  4225 None and Some, as well as exception Option.Option instead of OPTION.
  4226 The functions the, if_none, is_some, is_none have been adapted
  4227 accordingly, while Option.map replaces apsome.
  4228 
  4229 * Pure/library.ML: the exception LIST has been given up in favour of
  4230 the standard exceptions Empty and Subscript, as well as
  4231 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4232 superceded by the standard hd and tl functions etc.
  4233 
  4234 A number of basic list functions are no longer exported to the ML
  4235 toplevel, as they are variants of predefined functions.  The following
  4236 suggests how one can translate existing code:
  4237 
  4238     rev_append xs ys = List.revAppend (xs, ys)
  4239     nth_elem (i, xs) = List.nth (xs, i)
  4240     last_elem xs = List.last xs
  4241     flat xss = List.concat xss
  4242     seq fs = List.app fs
  4243     partition P xs = List.partition P xs
  4244     mapfilter f xs = List.mapPartial f xs
  4245 
  4246 * Pure/library.ML: several combinators for linear functional
  4247 transformations, notably reverse application and composition:
  4248 
  4249   x |> f                f #> g
  4250   (x, y) |-> f          f #-> g
  4251 
  4252 * Pure/library.ML: introduced/changed precedence of infix operators:
  4253 
  4254   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4255   infix 2 ?;
  4256   infix 3 o oo ooo oooo;
  4257   infix 4 ~~ upto downto;
  4258 
  4259 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4260 infix operators.
  4261 
  4262 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4263 fold_map support linear functional transformations and nesting.  For
  4264 example:
  4265 
  4266   fold f [x1, ..., xN] y =
  4267     y |> f x1 |> ... |> f xN
  4268 
  4269   (fold o fold) f [xs1, ..., xsN] y =
  4270     y |> fold f xs1 |> ... |> fold f xsN
  4271 
  4272   fold f [x1, ..., xN] =
  4273     f x1 #> ... #> f xN
  4274 
  4275   (fold o fold) f [xs1, ..., xsN] =
  4276     fold f xs1 #> ... #> fold f xsN
  4277 
  4278 * Pure/library.ML: the following selectors on type 'a option are
  4279 available:
  4280 
  4281   the:               'a option -> 'a  (*partial*)
  4282   these:             'a option -> 'a  where 'a = 'b list
  4283   the_default: 'a -> 'a option -> 'a
  4284   the_list:          'a option -> 'a list
  4285 
  4286 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4287 basic operations for association lists, following natural argument
  4288 order; moreover the explicit equality predicate passed here avoids
  4289 potentially expensive polymorphic runtime equality checks.
  4290 The old functions may be expressed as follows:
  4291 
  4292   assoc = uncurry (AList.lookup (op =))
  4293   assocs = these oo AList.lookup (op =)
  4294   overwrite = uncurry (AList.update (op =)) o swap
  4295 
  4296 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4297 
  4298   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4299   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4300 
  4301 replacing make_keylist and keyfilter (occassionally used)
  4302 Naive rewrites:
  4303 
  4304   make_keylist = AList.make
  4305   keyfilter = AList.find (op =)
  4306 
  4307 * eq_fst and eq_snd now take explicit equality parameter, thus
  4308   avoiding eqtypes. Naive rewrites:
  4309 
  4310     eq_fst = eq_fst (op =)
  4311     eq_snd = eq_snd (op =)
  4312 
  4313 * Removed deprecated apl and apr (rarely used).
  4314   Naive rewrites:
  4315 
  4316     apl (n, op) =>>= curry op n
  4317     apr (op, m) =>>= fn n => op (n, m)
  4318 
  4319 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4320 provides a reasonably efficient light-weight implementation of sets as
  4321 lists.
  4322 
  4323 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4324 few new operations; existing lookup and update are now curried to
  4325 follow natural argument order (for use with fold etc.);
  4326 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4327 
  4328 * Pure/General: output via the Isabelle channels of
  4329 writeln/warning/error etc. is now passed through Output.output, with a
  4330 hook for arbitrary transformations depending on the print_mode
  4331 (cf. Output.add_mode -- the first active mode that provides a output
  4332 function wins).  Already formatted output may be embedded into further
  4333 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4334 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4335 accommodate easy composition of diagnostic messages etc.  Programmers
  4336 rarely need to care about Output.output or Output.raw at all, with
  4337 some notable exceptions: Output.output is required when bypassing the
  4338 standard channels (writeln etc.), or in token translations to produce
  4339 properly formatted results; Output.raw is required when capturing
  4340 already output material that will eventually be presented to the user
  4341 a second time.  For the default print mode, both Output.output and
  4342 Output.raw have no effect.
  4343 
  4344 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4345 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4346 cumulative results are displayed at the end of a batch session.
  4347 
  4348 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4349 replaced by File.platform_path and File.shell_path (with appropriate
  4350 hooks).  This provides a clean interface for unusual systems where the
  4351 internal and external process view of file names are different.
  4352 
  4353 * Pure: more efficient orders for basic syntactic entities: added
  4354 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4355 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4356 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4357 orders now -- potential INCOMPATIBILITY for code that depends on a
  4358 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4359 Library.sort_strings on result).
  4360 
  4361 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4362 fold_types traverse types/terms from left to right, observing natural
  4363 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4364 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4365 
  4366 * Pure: name spaces have been refined, with significant changes of the
  4367 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4368 to extern(_table).  The plain name entry path is superceded by a
  4369 general 'naming' context, which also includes the 'policy' to produce
  4370 a fully qualified name and external accesses of a fully qualified
  4371 name; NameSpace.extend is superceded by context dependent
  4372 Sign.declare_name.  Several theory and proof context operations modify
  4373 the naming context.  Especially note Theory.restore_naming and
  4374 ProofContext.restore_naming to get back to a sane state; note that
  4375 Theory.add_path is no longer sufficient to recover from
  4376 Theory.absolute_path in particular.
  4377 
  4378 * Pure: new flags short_names (default false) and unique_names
  4379 (default true) for controlling output of qualified names.  If
  4380 short_names is set, names are printed unqualified.  If unique_names is
  4381 reset, the name prefix is reduced to the minimum required to achieve
  4382 the original result when interning again, even if there is an overlap
  4383 with earlier declarations.
  4384 
  4385 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4386 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4387 (useful for printing error messages).  INCOMPATIBILITY.
  4388 
  4389 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4390 Theory.theory are now identified, referring to the universal
  4391 Context.theory (see Pure/context.ML).  Actual signature and theory
  4392 content is managed as theory data.  The old code and interfaces were
  4393 spread over many files and structures; the new arrangement introduces
  4394 considerable INCOMPATIBILITY to gain more clarity:
  4395 
  4396   Context -- theory management operations (name, identity, inclusion,
  4397     parents, ancestors, merge, etc.), plus generic theory data;
  4398 
  4399   Sign -- logical signature and syntax operations (declaring consts,
  4400     types, etc.), plus certify/read for common entities;
  4401 
  4402   Theory -- logical theory operations (stating axioms, definitions,
  4403     oracles), plus a copy of logical signature operations (consts,
  4404     types, etc.); also a few basic management operations (Theory.copy,
  4405     Theory.merge, etc.)
  4406 
  4407 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4408 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4409 for convenience -- they merely return the theory.
  4410 
  4411 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4412 
  4413 * Pure: the Isar proof context type is already defined early in Pure
  4414 as Context.proof (note that ProofContext.context and Proof.context are
  4415 aliases, where the latter is the preferred name).  This enables other
  4416 Isabelle components to refer to that type even before Isar is present.
  4417 
  4418 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4419 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4420 any of these kinds.  For example, Sign.intern typeK is now
  4421 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4422 Theory.hide_types.  Also note that former
  4423 Theory.hide_classes/types/consts are now
  4424 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4425 internalize their arguments!  INCOMPATIBILITY.
  4426 
  4427 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4428 datatype thmref (with constructors Name and NameSelection) instead of
  4429 plain string -- INCOMPATIBILITY;
  4430 
  4431 * Pure: cases produced by proof methods specify options, where NONE
  4432 means to remove case bindings -- INCOMPATIBILITY in
  4433 (RAW_)METHOD_CASES.
  4434 
  4435 * Pure: the following operations retrieve axioms or theorems from a
  4436 theory node or theory hierarchy, respectively:
  4437 
  4438   Theory.axioms_of: theory -> (string * term) list
  4439   Theory.all_axioms_of: theory -> (string * term) list
  4440   PureThy.thms_of: theory -> (string * thm) list
  4441   PureThy.all_thms_of: theory -> (string * thm) list
  4442 
  4443 * Pure: print_tac now outputs the goal through the trace channel.
  4444 
  4445 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4446 Reference Toplevel.debug (default false) controls detailed printing
  4447 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4448 controls execution profiling -- set to 1 for time and 2 for space
  4449 (both increase the runtime).
  4450 
  4451 * Isar session: The initial use of ROOT.ML is now always timed,
  4452 i.e. the log will show the actual process times, in contrast to the
  4453 elapsed wall-clock time that the outer shell wrapper produces.
  4454 
  4455 * Simplifier: improved handling of bound variables (nameless
  4456 representation, avoid allocating new strings).  Simprocs that invoke
  4457 the Simplifier recursively should use Simplifier.inherit_bounds to
  4458 avoid local name clashes.  Failure to do so produces warnings
  4459 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4460 for further details.
  4461 
  4462 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4463 bindings for all theorems stored within a given theory; this may help
  4464 in porting non-Isar theories to Isar ones, while keeping ML proof
  4465 scripts for the time being.
  4466 
  4467 * ML operator HTML.with_charset specifies the charset begin used for
  4468 generated HTML files.  For example:
  4469 
  4470   HTML.with_charset "utf-8" use_thy "Hebrew";
  4471   HTML.with_charset "utf-8" use_thy "Chinese";
  4472 
  4473 
  4474 *** System ***
  4475 
  4476 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4477 isabelle, isatool etc.).
  4478 
  4479 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4480 isatool doc, isatool mkdir, display_drafts etc.).
  4481 
  4482 * isatool usedir: option -f allows specification of the ML file to be
  4483 used by Isabelle; default is ROOT.ML.
  4484 
  4485 * New isatool version outputs the version identifier of the Isabelle
  4486 distribution being used.
  4487 
  4488 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4489 (containing Boolean satisfiability problems) into Isabelle/HOL
  4490 theories.
  4491 
  4492 
  4493 
  4494 New in Isabelle2004 (April 2004)
  4495 --------------------------------
  4496 
  4497 *** General ***
  4498 
  4499 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4500   Replaces linorder.ML.
  4501 
  4502 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4503   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4504   (\<a>...\<z>), are now considered normal letters, and can therefore
  4505   be used anywhere where an ASCII letter (a...zA...Z) has until
  4506   now. COMPATIBILITY: This obviously changes the parsing of some
  4507   terms, especially where a symbol has been used as a binder, say
  4508   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4509   as an identifier.  Fix it by inserting a space around former
  4510   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4511   existing theory and ML files.
  4512 
  4513 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4514 
  4515 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4516   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4517   a normal (but invisible) letter. For multiple letter subscripts repeat
  4518   \<^isub> like this: x\<^isub>1\<^isub>2.
  4519 
  4520 * Pure: There are now sub-/superscripts that can span more than one
  4521   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4522   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4523   superscript. The new control characters are not identifier parts.
  4524 
  4525 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4526   content of "..." to the latex file instead of \isacntrl... . The "..."
  4527   may consist of any printable characters excluding the end bracket >.
  4528 
  4529 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4530   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4531   declare constants "final", which prevents their being given a definition
  4532   later.  It is useful for constants whose behaviour is fixed axiomatically
  4533   rather than definitionally, such as the meta-logic connectives.
  4534 
  4535 * Pure: 'instance' now handles general arities with general sorts
  4536   (i.e. intersections of classes),
  4537 
  4538 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4539   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4540   It can be changed to alter the colors/layout of generated pages.
  4541 
  4542 
  4543 *** Isar ***
  4544 
  4545 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4546   cut_tac, subgoal_tac and thin_tac:
  4547   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4548     locales are no longer forced to write Isar proof scripts.
  4549     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4550     emulations.
  4551   - INCOMPATIBILITY: names of variables to be instantiated may no
  4552     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4553     This is consistent with the instantiation attribute "where".
  4554 
  4555 * Attributes "where" and "of":
  4556   - Now take type variables of instantiated theorem into account when reading
  4557     the instantiation string.  This fixes a bug that caused instantiated
  4558     theorems to have too special types in some circumstances.
  4559   - "where" permits explicit instantiations of type variables.
  4560 
  4561 * Calculation commands "moreover" and "also" no longer interfere with
  4562   current facts ("this"), admitting arbitrary combinations with "then"
  4563   and derived forms.
  4564 
  4565 * Locales:
  4566   - Goal statements involving the context element "includes" no longer
  4567     generate theorems with internal delta predicates (those ending on
  4568     "_axioms") in the premise.
  4569     Resolve particular premise with <locale>.intro to obtain old form.
  4570   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4571     specification and "includes" elements in goal statement.
  4572   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4573     [intro?] and [elim?] (respectively) by default.
  4574   - Experimental command for instantiation of locales in proof contexts:
  4575         instantiate <label>[<attrs>]: <loc>
  4576     Instantiates locale <loc> and adds all its theorems to the current context
  4577     taking into account their attributes.  Label and attrs are optional
  4578     modifiers, like in theorem declarations.  If present, names of
  4579     instantiated theorems are qualified with <label>, and the attributes
  4580     <attrs> are applied after any attributes these theorems might have already.
  4581       If the locale has assumptions, a chained fact of the form
  4582     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4583     are derived.  The command does not support old-style locales declared
  4584     with "locale (open)".
  4585       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4586 
  4587 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4588   (Isar) contexts.
  4589 
  4590 
  4591 *** HOL ***
  4592 
  4593 * Proof import: new image HOL4 contains the imported library from
  4594   the HOL4 system with about 2500 theorems. It is imported by
  4595   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4596   can be used like any other Isabelle image.  See
  4597   HOL/Import/HOL/README for more information.
  4598 
  4599 * Simplifier:
  4600   - Much improved handling of linear and partial orders.
  4601     Reasoners for linear and partial orders are set up for type classes
  4602     "linorder" and "order" respectively, and are added to the default simpset
  4603     as solvers.  This means that the simplifier can build transitivity chains
  4604     to solve goals from the assumptions.
  4605   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4606     of blast or auto after simplification become unnecessary because the goal
  4607     is solved by simplification already.
  4608 
  4609 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4610     all proved in axiomatic type classes for semirings, rings and fields.
  4611 
  4612 * Numerics:
  4613   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4614     now formalized using the Ring_and_Field theory mentioned above.
  4615   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4616     than before, because now they are set up once in a generic manner.
  4617   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4618     Look for the general versions in Ring_and_Field (and Power if they concern
  4619     exponentiation).
  4620 
  4621 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4622 
  4623 * Records:
  4624   - Record types are now by default printed with their type abbreviation
  4625     instead of the list of all field types. This can be configured via
  4626     the reference "print_record_type_abbr".
  4627   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4628     (not enabled by default).
  4629   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4630     EX x. x = sel r to True (not enabled by default).
  4631   - Tactic "record_split_simp_tac" to split and simplify records added.
  4632 
  4633 * 'specification' command added, allowing for definition by
  4634   specification.  There is also an 'ax_specification' command that
  4635   introduces the new constants axiomatically.
  4636 
  4637 * arith(_tac) is now able to generate counterexamples for reals as well.
  4638 
  4639 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4640 
  4641 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4642   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4643 
  4644 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4645   matrix theory to linear programming.
  4646 
  4647 * Unions and Intersections:
  4648   The latex output syntax of UN and INT has been changed
  4649   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4650   i.e. the index formulae has become a subscript.
  4651   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4652 
  4653 * Unions and Intersections over Intervals:
  4654   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4655   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4656   like in normal math, and corresponding versions for < and for intersection.
  4657 
  4658 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4659   lexicographic dictonary ordering has been added as "lexord".
  4660 
  4661 * ML: the legacy theory structures Int and List have been removed. They had
  4662   conflicted with ML Basis Library structures having the same names.
  4663 
  4664 * 'refute' command added to search for (finite) countermodels.  Only works
  4665   for a fragment of HOL.  The installation of an external SAT solver is
  4666   highly recommended.  See "HOL/Refute.thy" for details.
  4667 
  4668 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4669   formulae under an assignment of free variables to random values.
  4670   In contrast to 'refute', it can deal with inductive datatypes,
  4671   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4672   for examples.
  4673 
  4674 
  4675 *** HOLCF ***
  4676 
  4677 * Streams now come with concatenation and are part of the HOLCF image
  4678 
  4679 
  4680 
  4681 New in Isabelle2003 (May 2003)
  4682 ------------------------------
  4683 
  4684 *** General ***
  4685 
  4686 * Provers/simplifier:
  4687 
  4688   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4689     Assumptions are now subject to complete mutual simplification,
  4690     not just from left to right. The simplifier now preserves
  4691     the order of assumptions.
  4692 
  4693     Potential INCOMPATIBILITY:
  4694 
  4695     -- simp sometimes diverges where the old version did
  4696        not, e.g. invoking simp on the goal
  4697 
  4698         [| P (f x); y = x; f x = f y |] ==> Q
  4699 
  4700        now gives rise to the infinite reduction sequence
  4701 
  4702         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4703 
  4704        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4705        kind of problem.
  4706 
  4707     -- Tactics combining classical reasoner and simplification (such as auto)
  4708        are also affected by this change, because many of them rely on
  4709        simp. They may sometimes diverge as well or yield a different numbers
  4710        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4711        in case of problems. Sometimes subsequent calls to the classical
  4712        reasoner will fail because a preceeding call to the simplifier too
  4713        eagerly simplified the goal, e.g. deleted redundant premises.
  4714 
  4715   - The simplifier trace now shows the names of the applied rewrite rules
  4716 
  4717   - You can limit the number of recursive invocations of the simplifier
  4718     during conditional rewriting (where the simplifie tries to solve the
  4719     conditions before applying the rewrite rule):
  4720     ML "simp_depth_limit := n"
  4721     where n is an integer. Thus you can force termination where previously
  4722     the simplifier would diverge.
  4723 
  4724   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4725 
  4726   - No longer aborts on failed congruence proof.  Instead, the
  4727     congruence is ignored.
  4728 
  4729 * Pure: New generic framework for extracting programs from constructive
  4730   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4731   as HOL/Extraction for some case studies.
  4732 
  4733 * Pure: The main goal of the proof state is no longer shown by default, only
  4734 the subgoals. This behaviour is controlled by a new flag.
  4735    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4736 (ML: Proof.show_main_goal).
  4737 
  4738 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4739 rules whose conclusion matches subgoal 1:
  4740       PG menu: Isabelle/Isar -> Show me -> matching rules
  4741 The rules are ordered by how closely they match the subgoal.
  4742 In particular, rules that solve a subgoal outright are displayed first
  4743 (or rather last, the way they are printed).
  4744 (ML: ProofGeneral.print_intros())
  4745 
  4746 * Pure: New flag trace_unify_fail causes unification to print
  4747 diagnostic information (PG: in trace buffer) when it fails. This is
  4748 useful for figuring out why single step proofs like rule, erule or
  4749 assumption failed.
  4750 
  4751 * Pure: Locale specifications now produce predicate definitions
  4752 according to the body of text (covering assumptions modulo local
  4753 definitions); predicate "loc_axioms" covers newly introduced text,
  4754 while "loc" is cumulative wrt. all included locale expressions; the
  4755 latter view is presented only on export into the global theory
  4756 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4757 on the old view without predicates;
  4758 
  4759 * Pure: predefined locales "var" and "struct" are useful for sharing
  4760 parameters (as in CASL, for example); just specify something like
  4761 ``var x + var y + struct M'' as import;
  4762 
  4763 * Pure: improved thms_containing: proper indexing of facts instead of
  4764 raw theorems; check validity of results wrt. current name space;
  4765 include local facts of proof configuration (also covers active
  4766 locales), cover fixed variables in index; may use "_" in term
  4767 specification; an optional limit for the number of printed facts may
  4768 be given (the default is 40);
  4769 
  4770 * Pure: disallow duplicate fact bindings within new-style theory files
  4771 (batch-mode only);
  4772 
  4773 * Provers: improved induct method: assumptions introduced by case
  4774 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4775 the goal statement); "foo" still refers to all facts collectively;
  4776 
  4777 * Provers: the function blast.overloaded has been removed: all constants
  4778 are regarded as potentially overloaded, which improves robustness in exchange
  4779 for slight decrease in efficiency;
  4780 
  4781 * Provers/linorder: New generic prover for transitivity reasoning over
  4782 linear orders.  Note: this prover is not efficient!
  4783 
  4784 * Isar: preview of problems to finish 'show' now produce an error
  4785 rather than just a warning (in interactive mode);
  4786 
  4787 
  4788 *** HOL ***
  4789 
  4790 * arith(_tac)
  4791 
  4792  - Produces a counter example if it cannot prove a goal.
  4793    Note that the counter example may be spurious if the goal is not a formula
  4794    of quantifier-free linear arithmetic.
  4795    In ProofGeneral the counter example appears in the trace buffer.
  4796 
  4797  - Knows about div k and mod k where k is a numeral of type nat or int.
  4798 
  4799  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4800    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4801    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4802 
  4803 * simp's arithmetic capabilities have been enhanced a bit: it now
  4804 takes ~= in premises into account (by performing a case split);
  4805 
  4806 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4807 are distributed over a sum of terms;
  4808 
  4809 * New tactic "trans_tac" and method "trans" instantiate
  4810 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4811 "<=", "<" and "=").
  4812 
  4813 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4814 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4815 
  4816 * 'typedef' command has new option "open" to suppress the set
  4817 definition;
  4818 
  4819 * functions Min and Max on finite sets have been introduced (theory
  4820 Finite_Set);
  4821 
  4822 * attribute [symmetric] now works for relations as well; it turns
  4823 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4824 
  4825 * induct over a !!-quantified statement (say !!x1..xn):
  4826   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4827 
  4828 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4829 %x. None. Warning: empty_def now refers to the previously hidden definition
  4830 of the empty set.
  4831 
  4832 * Algebra: formalization of classical algebra.  Intended as base for
  4833 any algebraic development in Isabelle.  Currently covers group theory
  4834 (up to Sylow's theorem) and ring theory (Universal Property of
  4835 Univariate Polynomials).  Contributions welcome;
  4836 
  4837 * GroupTheory: deleted, since its material has been moved to Algebra;
  4838 
  4839 * Complex: new directory of the complex numbers with numeric constants,
  4840 nonstandard complex numbers, and some complex analysis, standard and
  4841 nonstandard (Jacques Fleuriot);
  4842 
  4843 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4844 
  4845 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4846 Fleuriot);
  4847 
  4848 * Real/HahnBanach: updated and adapted to locales;
  4849 
  4850 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4851 Gray and Kramer);
  4852 
  4853 * UNITY: added the Meier-Sanders theory of progress sets;
  4854 
  4855 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4856 as abstract algorithms, instantiated to the JVM;
  4857 
  4858 * Bali: Java source language formalization. Type system, operational
  4859 semantics, axiomatic semantics. Supported language features:
  4860 classes, interfaces, objects,virtual methods, static methods,
  4861 static/instance fields, arrays, access modifiers, definite
  4862 assignment, exceptions.
  4863 
  4864 
  4865 *** ZF ***
  4866 
  4867 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4868 universe, etc.);
  4869 
  4870 * Main ZF: virtually all theories converted to new-style format;
  4871 
  4872 
  4873 *** ML ***
  4874 
  4875 * Pure: Tactic.prove provides sane interface for internal proofs;
  4876 omits the infamous "standard" operation, so this is more appropriate
  4877 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4878 
  4879 * Pure: improved error reporting of simprocs;
  4880 
  4881 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4882 up simprocs;
  4883 
  4884 
  4885 *** Document preparation ***
  4886 
  4887 * uses \par instead of \\ for line breaks in theory text. This may
  4888 shift some page breaks in large documents. To get the old behaviour
  4889 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4890 
  4891 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4892 other packages
  4893 
  4894 * \<euro> now needs package babel/greek instead of marvosym (which
  4895 broke \Rightarrow)
  4896 
  4897 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4898 textcomp package)
  4899 
  4900 
  4901 
  4902 New in Isabelle2002 (March 2002)
  4903 --------------------------------
  4904 
  4905 *** Document preparation ***
  4906 
  4907 * greatly simplified document preparation setup, including more
  4908 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4909 instructive isatool mkdir; users should basically be able to get
  4910 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4911 users may run a separate document processing stage manually like this:
  4912 "isatool usedir -D output HOL Test && isatool document Test/output";
  4913 
  4914 * theory dependency graph may now be incorporated into documents;
  4915 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4916 with \includegraphics of LaTeX;
  4917 
  4918 * proper spacing of consecutive markup elements, especially text
  4919 blocks after section headings;
  4920 
  4921 * support bold style (for single symbols only), input syntax is like
  4922 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4923 
  4924 * \<bullet> is now output as bold \cdot by default, which looks much
  4925 better in printed text;
  4926 
  4927 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4928 note that these symbols are currently unavailable in Proof General /
  4929 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4930 
  4931 * isatool latex no longer depends on changed TEXINPUTS, instead
  4932 isatool document copies the Isabelle style files to the target
  4933 location;
  4934 
  4935 
  4936 *** Isar ***
  4937 
  4938 * Pure/Provers: improved proof by cases and induction;
  4939   - 'case' command admits impromptu naming of parameters (such as
  4940     "case (Suc n)");
  4941   - 'induct' method divinates rule instantiation from the inductive
  4942     claim; no longer requires excessive ?P bindings for proper
  4943     instantiation of cases;
  4944   - 'induct' method properly enumerates all possibilities of set/type
  4945     rules; as a consequence facts may be also passed through *type*
  4946     rules without further ado;
  4947   - 'induct' method now derives symbolic cases from the *rulified*
  4948     rule (before it used to rulify cases stemming from the internal
  4949     atomized version); this means that the context of a non-atomic
  4950     statement becomes is included in the hypothesis, avoiding the
  4951     slightly cumbersome show "PROP ?case" form;
  4952   - 'induct' may now use elim-style induction rules without chaining
  4953     facts, using ``missing'' premises from the goal state; this allows
  4954     rules stemming from inductive sets to be applied in unstructured
  4955     scripts, while still benefitting from proper handling of non-atomic
  4956     statements; NB: major inductive premises need to be put first, all
  4957     the rest of the goal is passed through the induction;
  4958   - 'induct' proper support for mutual induction involving non-atomic
  4959     rule statements (uses the new concept of simultaneous goals, see
  4960     below);
  4961   - append all possible rule selections, but only use the first
  4962     success (no backtracking);
  4963   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4964   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4965   - added 'print_induct_rules' (covered by help item in recent Proof
  4966     General versions);
  4967   - moved induct/cases attributes to Pure, methods to Provers;
  4968   - generic method setup instantiated for FOL and HOL;
  4969 
  4970 * Pure: support multiple simultaneous goal statements, for example
  4971 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4972 meta-level mechanism, this acts as if several individual goals had
  4973 been stated separately; in particular common proof methods need to be
  4974 repeated in order to cover all claims; note that a single elimination
  4975 step is *not* sufficient to establish the two conjunctions, so this
  4976 fails:
  4977 
  4978   assume "A & B" then have A and B ..   (*".." fails*)
  4979 
  4980 better use "obtain" in situations as above; alternative refer to
  4981 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4982 
  4983 * Pure: proper integration with ``locales''; unlike the original
  4984 version by Florian Kammller, Isar locales package high-level proof
  4985 contexts rather than raw logical ones (e.g. we admit to include
  4986 attributes everywhere); operations on locales include merge and
  4987 rename; support for implicit arguments (``structures''); simultaneous
  4988 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4989 some examples;
  4990 
  4991 * Pure: the following commands have been ``localized'', supporting a
  4992 target locale specification "(in name)": 'lemma', 'theorem',
  4993 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4994 stored both within the locale and at the theory level (exported and
  4995 qualified by the locale name);
  4996 
  4997 * Pure: theory goals may now be specified in ``long'' form, with
  4998 ad-hoc contexts consisting of arbitrary locale elements. for example
  4999 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5000 definitions may be given, too); the result is a meta-level rule with
  5001 the context elements being discharged in the obvious way;
  5002 
  5003 * Pure: new proof command 'using' allows to augment currently used
  5004 facts after a goal statement ('using' is syntactically analogous to
  5005 'apply', but acts on the goal's facts only); this allows chained facts
  5006 to be separated into parts given before and after a claim, as in
  5007 ``from a and b have C using d and e <proof>'';
  5008 
  5009 * Pure: renamed "antecedent" case to "rule_context";
  5010 
  5011 * Pure: new 'judgment' command records explicit information about the
  5012 object-logic embedding (used by several tools internally); no longer
  5013 use hard-wired "Trueprop";
  5014 
  5015 * Pure: added 'corollary' command;
  5016 
  5017 * Pure: fixed 'token_translation' command;
  5018 
  5019 * Pure: removed obsolete 'exported' attribute;
  5020 
  5021 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5022 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5023 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5024 
  5025 * Pure: method 'atomize' presents local goal premises as object-level
  5026 statements (atomic meta-level propositions); setup controlled via
  5027 rewrite rules declarations of 'atomize' attribute; example
  5028 application: 'induct' method with proper rule statements in improper
  5029 proof *scripts*;
  5030 
  5031 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5032 now consider the syntactic context of assumptions, giving a better
  5033 chance to get type-inference of the arguments right (this is
  5034 especially important for locales);
  5035 
  5036 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5037 mode;
  5038 
  5039 * Pure/obtain: the formal conclusion "thesis", being marked as
  5040 ``internal'', may no longer be reference directly in the text;
  5041 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5042 situations;
  5043 
  5044 * Pure: generic 'sym' attribute which declares a rule both as pure
  5045 'elim?' and for the 'symmetric' operation;
  5046 
  5047 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5048 text; the fixed correlation with particular command syntax has been
  5049 discontinued;
  5050 
  5051 * Pure: new method 'rules' is particularly well-suited for proof
  5052 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5053 but often produces more compact proof terms with less detours;
  5054 
  5055 * Pure/Provers/classical: simplified integration with pure rule
  5056 attributes and methods; the classical "intro?/elim?/dest?"
  5057 declarations coincide with the pure ones; the "rule" method no longer
  5058 includes classically swapped intros; "intro" and "elim" methods no
  5059 longer pick rules from the context; also got rid of ML declarations
  5060 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5061 INCOMPATIBILITY;
  5062 
  5063 * Provers/classical: attribute 'swapped' produces classical inversions
  5064 of introduction rules;
  5065 
  5066 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5067 rules instead of full simplifier context; 'iff' attribute handles
  5068 conditional rules;
  5069 
  5070 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5071 
  5072 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5073 "(permissive)" option to recover old behavior;
  5074 
  5075 * HOL: 'inductive' no longer features separate (collective) attributes
  5076 for 'intros' (was found too confusing);
  5077 
  5078 * HOL: properly declared induction rules less_induct and
  5079 wf_induct_rule;
  5080 
  5081 
  5082 *** HOL ***
  5083 
  5084 * HOL: moved over to sane numeral syntax; the new policy is as
  5085 follows:
  5086 
  5087   - 0 and 1 are polymorphic constants, which are defined on any
  5088   numeric type (nat, int, real etc.);
  5089 
  5090   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5091   binary representation internally;
  5092 
  5093   - type nat has special constructor Suc, and generally prefers Suc 0
  5094   over 1::nat and Suc (Suc 0) over 2::nat;
  5095 
  5096 This change may cause significant problems of INCOMPATIBILITY; here
  5097 are some hints on converting existing sources:
  5098 
  5099   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5100   entities, so expressions involving "-" (unary or binary minus) need
  5101   to be spaced properly;
  5102 
  5103   - existing occurrences of "1" may need to be constraint "1::nat" or
  5104   even replaced by Suc 0; similar for old "2";
  5105 
  5106   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5107 
  5108   - remove all special provisions on numerals in proofs;
  5109 
  5110 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5111 representation (depends on bin_arith_simps in the default context);
  5112 
  5113 * HOL: symbolic syntax for x^2 (numeral 2);
  5114 
  5115 * HOL: the class of all HOL types is now called "type" rather than
  5116 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5117 in axclass/classes, instance/arities, and (usually rare) occurrences
  5118 in typings (of consts etc.); internally the class is called
  5119 "HOL.type", ML programs should refer to HOLogic.typeS;
  5120 
  5121 * HOL/record package improvements:
  5122   - new derived operations "fields" to build a partial record section,
  5123     "extend" to promote a fixed record to a record scheme, and
  5124     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5125     declared as simp by default;
  5126   - shared operations ("more", "fields", etc.) now need to be always
  5127     qualified) --- potential INCOMPATIBILITY;
  5128   - removed "make_scheme" operations (use "make" with "extend") --
  5129     INCOMPATIBILITY;
  5130   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5131   - provides cases/induct rules for use with corresponding Isar
  5132     methods (for concrete records, record schemes, concrete more
  5133     parts, and schematic more parts -- in that order);
  5134   - internal definitions directly based on a light-weight abstract
  5135     theory of product types over typedef rather than datatype;
  5136 
  5137 * HOL: generic code generator for generating executable ML code from
  5138 specifications; specific support for HOL constructs such as inductive
  5139 datatypes and sets, as well as recursive functions; can be invoked
  5140 via 'generate_code' theory section;
  5141 
  5142 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5143 
  5144 * HOL: consolidated and renamed several theories.  In particular:
  5145         Ord.thy has been absorbed into HOL.thy
  5146         String.thy has been absorbed into List.thy
  5147 
  5148 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5149 (beware of argument permutation!);
  5150 
  5151 * HOL: linorder_less_split superseded by linorder_cases;
  5152 
  5153 * HOL/List: "nodups" renamed to "distinct";
  5154 
  5155 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5156 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5157   - Ex_def has changed, now need to use some_eq_ex
  5158 
  5159 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5160 in this (rare) case use:
  5161 
  5162   delSWrapper "split_all_tac"
  5163   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5164 
  5165 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5166 MAY FAIL;
  5167 
  5168 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5169 Isabelle's type classes, ^ on functions and relations has too general
  5170 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5171 necessary to attach explicit type constraints;
  5172 
  5173 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5174 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5175 renamed accordingly (eg "compI" -> "rel_compI").
  5176 
  5177 * HOL: syntax translations now work properly with numerals and records
  5178 expressions;
  5179 
  5180 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5181 of "lam" -- INCOMPATIBILITY;
  5182 
  5183 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5184 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5185 renamed "Product_Type.unit";
  5186 
  5187 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5188 
  5189 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5190 the "cases" method);
  5191 
  5192 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5193 Florian Kammller);
  5194 
  5195 * HOL/IMP: updated and converted to new-style theory format; several
  5196 parts turned into readable document, with proper Isar proof texts and
  5197 some explanations (by Gerwin Klein);
  5198 
  5199 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5200 
  5201 * HOL-Hyperreal is now a logic image;
  5202 
  5203 
  5204 *** HOLCF ***
  5205 
  5206 * Isar: consts/constdefs supports mixfix syntax for continuous
  5207 operations;
  5208 
  5209 * Isar: domain package adapted to new-style theory format, e.g. see
  5210 HOLCF/ex/Dnat.thy;
  5211 
  5212 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5213 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5214 lift.induct_tac, always use UU instead of Undef;
  5215 
  5216 * HOLCF/IMP: updated and converted to new-style theory;
  5217 
  5218 
  5219 *** ZF ***
  5220 
  5221 * Isar: proper integration of logic-specific tools and packages,
  5222 including theory commands '(co)inductive', '(co)datatype',
  5223 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5224 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5225 
  5226 * theory Main no longer includes AC; for the Axiom of Choice, base
  5227 your theory on Main_ZFC;
  5228 
  5229 * the integer library now covers quotients and remainders, with many
  5230 laws relating division to addition, multiplication, etc.;
  5231 
  5232 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5233 typeless version of the formalism;
  5234 
  5235 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5236 format;
  5237 
  5238 * ZF/Induct: new directory for examples of inductive definitions,
  5239 including theory Multiset for multiset orderings; converted to
  5240 new-style theory format;
  5241 
  5242 * ZF: many new theorems about lists, ordinals, etc.;
  5243 
  5244 
  5245 *** General ***
  5246 
  5247 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5248 variable proof controls level of detail: 0 = no proofs (only oracle
  5249 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5250 also ref manual for further ML interfaces;
  5251 
  5252 * Pure/axclass: removed obsolete ML interface
  5253 goal_subclass/goal_arity;
  5254 
  5255 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5256 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5257 separate tokens, so expressions involving minus need to be spaced
  5258 properly;
  5259 
  5260 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5261 rather than "infixl" or "infixr";
  5262 
  5263 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5264 sort constraint specifications in type inference; e.g. "x::_::foo"
  5265 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5266 type variable);
  5267 
  5268 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5269 control output of nested => (types); the default behavior is
  5270 "type_brackets";
  5271 
  5272 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5273 tokens into AST constants;
  5274 
  5275 * Pure/syntax: prefer later declarations of translations and print
  5276 translation functions; potential INCOMPATIBILITY: need to reverse
  5277 multiple declarations for same syntax element constant;
  5278 
  5279 * Pure/show_hyps reset by default (in accordance to existing Isar
  5280 practice);
  5281 
  5282 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5283 addSafter;
  5284 
  5285 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5286 as well;
  5287 
  5288 * system: tested support for MacOS X; should be able to get Isabelle +
  5289 Proof General to work in a plain Terminal after installing Poly/ML
  5290 (e.g. from the Isabelle distribution area) and GNU bash alone
  5291 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5292 support requires further installations, e.g. from
  5293 http://fink.sourceforge.net/);
  5294 
  5295 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5296 
  5297 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5298 of 40 MB), cf. ML_OPTIONS;
  5299 
  5300 * system: Proof General keywords specification is now part of the
  5301 Isabelle distribution (see etc/isar-keywords.el);
  5302 
  5303 * system: support for persistent Proof General sessions (refrain from
  5304 outdating all loaded theories on startup); user may create writable
  5305 logic images like this: ``isabelle -q HOL Test'';
  5306 
  5307 * system: smart selection of Isabelle process versus Isabelle
  5308 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5309 run both "isabelle" and "Isabelle" even if file names are badly
  5310 damaged (executable inspects the case of the first letter of its own
  5311 name); added separate "isabelle-process" and "isabelle-interface";
  5312 
  5313 * system: refrain from any attempt at filtering input streams; no
  5314 longer support ``8bit'' encoding of old isabelle font, instead proper
  5315 iso-latin characters may now be used; the related isatools
  5316 "symbolinput" and "nonascii" have disappeared as well;
  5317 
  5318 * system: removed old "xterm" interface (the print modes "xterm" and
  5319 "xterm_color" are still available for direct use in a suitable
  5320 terminal);
  5321 
  5322 
  5323 
  5324 New in Isabelle99-2 (February 2001)
  5325 -----------------------------------
  5326 
  5327 *** Overview of INCOMPATIBILITIES ***
  5328 
  5329 * HOL: please note that theories in the Library and elsewhere often use the
  5330 new-style (Isar) format; to refer to their theorems in an ML script you must
  5331 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5332 
  5333 * HOL: inductive package no longer splits induction rule aggressively,
  5334 but only as far as specified by the introductions given; the old
  5335 format may be recovered via ML function complete_split_rule or attribute
  5336 'split_rule (complete)';
  5337 
  5338 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5339 gfp_Tarski to gfp_unfold;
  5340 
  5341 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5342 
  5343 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5344 relation); infix "^^" has been renamed "``"; infix "``" has been
  5345 renamed "`"; "univalent" has been renamed "single_valued";
  5346 
  5347 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5348 operation;
  5349 
  5350 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5351 
  5352 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5353 
  5354 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5355 consequence, it is no longer monotonic wrt. the local goal context
  5356 (which is now passed through the inductive cases);
  5357 
  5358 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5359 \<gg> to \<ggreater>;
  5360 
  5361 
  5362 *** Document preparation ***
  5363 
  5364 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5365 available: are "it" for near math-mode best-style output, "sl" for
  5366 slanted text style, and "tt" for plain type-writer; if no
  5367 \isabellestyle command is given, output is according to slanted
  5368 type-writer);
  5369 
  5370 * support sub/super scripts (for single symbols only), input syntax is
  5371 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5372 
  5373 * some more standard symbols; see Appendix A of the system manual for
  5374 the complete list of symbols defined in isabellesym.sty;
  5375 
  5376 * improved isabelle style files; more abstract symbol implementation
  5377 (should now use \isamath{...} and \isatext{...} in custom symbol
  5378 definitions);
  5379 
  5380 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5381 state; Note that presentation of goal states does not conform to
  5382 actual human-readable proof documents.  Please do not include goal
  5383 states into document output unless you really know what you are doing!
  5384 
  5385 * proper indentation of antiquoted output with proportional LaTeX
  5386 fonts;
  5387 
  5388 * no_document ML operator temporarily disables LaTeX document
  5389 generation;
  5390 
  5391 * isatool unsymbolize tunes sources for plain ASCII communication;
  5392 
  5393 
  5394 *** Isar ***
  5395 
  5396 * Pure: Isar now suffers initial goal statements to contain unbound
  5397 schematic variables (this does not conform to actual readable proof
  5398 documents, due to unpredictable outcome and non-compositional proof
  5399 checking); users who know what they are doing may use schematic goals
  5400 for Prolog-style synthesis of proven results;
  5401 
  5402 * Pure: assumption method (an implicit finishing) now handles actual
  5403 rules as well;
  5404 
  5405 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5406 initial goal, declare "that" only as Pure intro (only for single
  5407 steps); the "that" rule assumption may now be involved in implicit
  5408 finishing, thus ".." becomes a feasible for trivial obtains;
  5409 
  5410 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5411 instance proofs may be performed by "..";
  5412 
  5413 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5414 statements as well;
  5415 
  5416 * Pure: more robust selection of calculational rules;
  5417 
  5418 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5419 rule (as well as the assumption rule);
  5420 
  5421 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5422 lemmas, using the graph browser tool;
  5423 
  5424 * Pure: predict failure of "show" in interactive mode;
  5425 
  5426 * Pure: 'thms_containing' now takes actual terms as arguments;
  5427 
  5428 * HOL: improved method 'induct' --- now handles non-atomic goals
  5429 (potential INCOMPATIBILITY); tuned error handling;
  5430 
  5431 * HOL: cases and induct rules now provide explicit hints about the
  5432 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5433 any remaining facts are inserted into the goal verbatim;
  5434 
  5435 * HOL: local contexts (aka cases) may now contain term bindings as
  5436 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5437 the result to be shown in each case;
  5438 
  5439 * HOL: added 'recdef_tc' command;
  5440 
  5441 * isatool convert assists in eliminating legacy ML scripts;
  5442 
  5443 
  5444 *** HOL ***
  5445 
  5446 * HOL/Library: a collection of generic theories to be used together
  5447 with main HOL; the theory loader path already includes this directory
  5448 by default; the following existing theories have been moved here:
  5449 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5450 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5451 
  5452 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5453 modelling and verification task performed in Isabelle/HOL +
  5454 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5455 
  5456 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5457 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5458 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5459 'domain', this makes the theory consistent with mathematical
  5460 literature;
  5461 
  5462 * HOL basics: added overloaded operations "inverse" and "divide"
  5463 (infix "/"), syntax for generic "abs" operation, generic summation
  5464 operator \<Sum>;
  5465 
  5466 * HOL/typedef: simplified package, provide more useful rules (see also
  5467 HOL/subset.thy);
  5468 
  5469 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5470 now expressed as a proper nested rule (old-style tactic scripts may
  5471 require atomize_strip_tac to cope with non-atomic premises);
  5472 
  5473 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5474 to "split_conv" (old name still available for compatibility);
  5475 
  5476 * HOL: improved concrete syntax for strings (e.g. allows translation
  5477 rules with string literals);
  5478 
  5479 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5480  and Fleuriot's mechanization of analysis, including the transcendental
  5481  functions for the reals;
  5482 
  5483 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5484 
  5485 
  5486 *** CTT ***
  5487 
  5488 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5489 "lam" is displayed as TWO lambda-symbols
  5490 
  5491 * CTT: theory Main now available, containing everything (that is, Bool
  5492 and Arith);
  5493 
  5494 
  5495 *** General ***
  5496 
  5497 * Pure: the Simplifier has been implemented properly as a derived rule
  5498 outside of the actual kernel (at last!); the overall performance
  5499 penalty in practical applications is about 50%, while reliability of
  5500 the Isabelle inference kernel has been greatly improved;
  5501 
  5502 * print modes "brackets" and "no_brackets" control output of nested =>
  5503 (types) and ==> (props); the default behaviour is "brackets";
  5504 
  5505 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5506 as assumptions as well;
  5507 
  5508 * system: support Poly/ML 4.0;
  5509 
  5510 * system: isatool install handles KDE version 1 or 2;
  5511 
  5512 
  5513 
  5514 New in Isabelle99-1 (October 2000)
  5515 ----------------------------------
  5516 
  5517 *** Overview of INCOMPATIBILITIES ***
  5518 
  5519 * HOL: simplification of natural numbers is much changed; to partly
  5520 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5521 issue the following ML commands:
  5522 
  5523   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5524   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5525 
  5526 * HOL: simplification no longer dives into case-expressions; this is
  5527 controlled by "t.weak_case_cong" for each datatype t;
  5528 
  5529 * HOL: nat_less_induct renamed to less_induct;
  5530 
  5531 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5532 fixsome to patch .thy and .ML sources automatically;
  5533 
  5534   select_equality  -> some_equality
  5535   select_eq_Ex     -> some_eq_ex
  5536   selectI2EX       -> someI2_ex
  5537   selectI2         -> someI2
  5538   selectI          -> someI
  5539   select1_equality -> some1_equality
  5540   Eps_sym_eq       -> some_sym_eq_trivial
  5541   Eps_eq           -> some_eq_trivial
  5542 
  5543 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5544 
  5545 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5546 instead);
  5547 
  5548 * HOL: the recursion equations generated by 'recdef' are now called
  5549 f.simps instead of f.rules;
  5550 
  5551 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5552 
  5553 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5554 sometimes be needed;
  5555 
  5556 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5557 
  5558 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5559 
  5560 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5561 product is now "<*>" instead of "Times"; the lexicographic product is
  5562 now "<*lex*>" instead of "**";
  5563 
  5564 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5565 of main HOL, but was unused); better use HOL's datatype package;
  5566 
  5567 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5568 the old syntax may be recovered as follows:
  5569 
  5570   syntax (symbols)
  5571     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5572       (infixl "\\<oplus>" 100)
  5573 
  5574 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5575 
  5576 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5577 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5578 internally;
  5579 
  5580 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5581 changed from A/r to A//r;
  5582 
  5583 * ZF: new treatment of arithmetic (nat & int) may break some old
  5584 proofs;
  5585 
  5586 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5587 rulify -> rule_format, elimify -> elim_format, ...);
  5588 
  5589 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5590 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5591 should have to change intro!! to intro? only); replaced "delrule" by
  5592 "rule del";
  5593 
  5594 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5595 
  5596 * Provers: strengthened force_tac by using new first_best_tac;
  5597 
  5598 * LaTeX document preparation: several changes of isabelle.sty (see
  5599 lib/texinputs);
  5600 
  5601 
  5602 *** Document preparation ***
  5603 
  5604 * formal comments (text blocks etc.) in new-style theories may now
  5605 contain antiquotations of thm/prop/term/typ/text to be presented
  5606 according to latex print mode; concrete syntax is like this:
  5607 @{term[show_types] "f(x) = a + x"};
  5608 
  5609 * isatool mkdir provides easy setup of Isabelle session directories,
  5610 including proper document sources;
  5611 
  5612 * generated LaTeX sources are now deleted after successful run
  5613 (isatool document -c); may retain a copy somewhere else via -D option
  5614 of isatool usedir;
  5615 
  5616 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5617 style files, achieving self-contained LaTeX sources and simplifying
  5618 LaTeX debugging;
  5619 
  5620 * old-style theories now produce (crude) LaTeX output as well;
  5621 
  5622 * browser info session directories are now self-contained (may be put
  5623 on WWW server seperately); improved graphs of nested sessions; removed
  5624 graph for 'all sessions';
  5625 
  5626 * several improvements in isabelle style files; \isabellestyle{it}
  5627 produces fake math mode output; \isamarkupheader is now \section by
  5628 default; see lib/texinputs/isabelle.sty etc.;
  5629 
  5630 
  5631 *** Isar ***
  5632 
  5633 * Isar/Pure: local results and corresponding term bindings are now
  5634 subject to Hindley-Milner polymorphism (similar to ML); this
  5635 accommodates incremental type-inference very nicely;
  5636 
  5637 * Isar/Pure: new derived language element 'obtain' supports
  5638 generalized existence reasoning;
  5639 
  5640 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5641 support accumulation of results, without applying any rules yet;
  5642 useful to collect intermediate results without explicit name
  5643 references, and for use with transitivity rules with more than 2
  5644 premises;
  5645 
  5646 * Isar/Pure: scalable support for case-analysis type proofs: new
  5647 'case' language element refers to local contexts symbolically, as
  5648 produced by certain proof methods; internally, case names are attached
  5649 to theorems as "tags";
  5650 
  5651 * Isar/Pure: theory command 'hide' removes declarations from
  5652 class/type/const name spaces;
  5653 
  5654 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5655 indicate potential overloading;
  5656 
  5657 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5658 
  5659 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5660 "{a,b,c}" instead of {a,b,c};
  5661 
  5662 * Isar/Pure now provides its own version of intro/elim/dest
  5663 attributes; useful for building new logics, but beware of confusion
  5664 with the version in Provers/classical;
  5665 
  5666 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5667 case name 'antecedent';
  5668 
  5669 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5670 to the current context is now done automatically);
  5671 
  5672 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5673 for definining proof methods in ML;
  5674 
  5675 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5676 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5677 most cases, one should have to change intro!! to intro? only);
  5678 replaced "delrule" by "rule del";
  5679 
  5680 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5681 'symmetric' attribute (the latter supercedes [RS sym]);
  5682 
  5683 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5684 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5685 well (including splits);
  5686 
  5687 * Isar/Provers: Simplifier and Classical methods now support all kind
  5688 of modifiers used in the past, including 'cong', 'iff', etc.
  5689 
  5690 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5691 of Simplifier and Classical reasoner);
  5692 
  5693 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5694 now support named cases; major packages (inductive, datatype, primrec,
  5695 recdef) support case names and properly name parameters;
  5696 
  5697 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5698 monotonicity conditions are extracted to be proven at end of
  5699 calculations;
  5700 
  5701 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5702 method anyway;
  5703 
  5704 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5705 split_if split_if_asm; datatype package provides theorems foo.splits =
  5706 foo.split foo.split_asm for each datatype;
  5707 
  5708 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5709 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5710 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5711 use "(cases (simplified))" method in proper proof texts);
  5712 
  5713 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5714 
  5715 * Isar: names of theorems etc. may be natural numbers as well;
  5716 
  5717 * Isar: 'pr' command: optional arguments for goals_limit and
  5718 ProofContext.prems_limit; no longer prints theory contexts, but only
  5719 proof states;
  5720 
  5721 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5722 additional print modes to be specified; e.g. "pr(latex)" will print
  5723 proof state according to the Isabelle LaTeX style;
  5724 
  5725 * Isar: improved support for emulating tactic scripts, including proof
  5726 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5727 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5728 (for HOL datatypes);
  5729 
  5730 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5731 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5732 'proof method scripts' have to be in depth-first order;
  5733 
  5734 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5735 
  5736 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5737 should instead use individual commands for printing items
  5738 (print_commands, print_methods etc.);
  5739 
  5740 * Isar: added 'nothing' --- the empty list of theorems;
  5741 
  5742 
  5743 *** HOL ***
  5744 
  5745 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5746 corresponding virtual machine and a specification of its bytecode
  5747 verifier and a lightweight bytecode verifier, including proofs of
  5748 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5749 Cornelia Pusch (see also the homepage of project Bali at
  5750 http://isabelle.in.tum.de/Bali/);
  5751 
  5752 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5753 Clemens Ballarin;
  5754 
  5755 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5756 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5757 Rasmussen;
  5758 
  5759 * HOL/Lattice: fundamental concepts of lattice theory and order
  5760 structures, including duals, properties of bounds versus algebraic
  5761 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5762 Theorem for complete lattices etc.; may also serve as a demonstration
  5763 for abstract algebraic reasoning using axiomatic type classes, and
  5764 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5765 
  5766 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5767 von Oheimb;
  5768 
  5769 * HOL/IMPP: extension of IMP with local variables and mutually
  5770 recursive procedures, by David von Oheimb;
  5771 
  5772 * HOL/Lambda: converted into new-style theory and document;
  5773 
  5774 * HOL/ex/Multiquote: example of multiple nested quotations and
  5775 anti-quotations -- basically a generalized version of de-Bruijn
  5776 representation; very useful in avoiding lifting of operations;
  5777 
  5778 * HOL/record: added general record equality rule to simpset; fixed
  5779 select-update simplification procedure to handle extended records as
  5780 well; admit "r" as field name;
  5781 
  5782 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5783 other numeric types and also as the identity of groups, rings, etc.;
  5784 
  5785 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5786 Types nat and int belong to this axclass;
  5787 
  5788 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5789    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5790    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5791   two terms #m*u and #n*u are replaced by #(m+n)*u
  5792     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5793   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5794     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5795 
  5796 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5797 powerful prover for predicate logic but knows nothing of clasets; see
  5798 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5799 
  5800 * HOL: new version of "case_tac" subsumes both boolean case split and
  5801 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5802 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5803 
  5804 * HOL: simplification no longer dives into case-expressions: only the
  5805 selector expression is simplified, but not the remaining arms; to
  5806 enable full simplification of case-expressions for datatype t, you may
  5807 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5808 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5809 
  5810 * HOL/recdef: the recursion equations generated by 'recdef' for
  5811 function 'f' are now called f.simps instead of f.rules; if all
  5812 termination conditions are proved automatically, these simplification
  5813 rules are added to the simpset, as in primrec; rules may be named
  5814 individually as well, resulting in a separate list of theorems for
  5815 each equation;
  5816 
  5817 * HOL/While is a new theory that provides a while-combinator. It
  5818 permits the definition of tail-recursive functions without the
  5819 provision of a termination measure. The latter is necessary once the
  5820 invariant proof rule for while is applied.
  5821 
  5822 * HOL: new (overloaded) notation for the set of elements below/above
  5823 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5824 
  5825 * HOL: theorems impI, allI, ballI bound as "strip";
  5826 
  5827 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5828 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5829 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5830 
  5831 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5832 
  5833 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5834 main HOL, but was unused);
  5835 
  5836 * HOL: fewer consts declared as global (e.g. have to refer to
  5837 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5838 
  5839 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5840 in case of overlap with user translations (e.g. judgements over
  5841 tuples); (note that the underlying logical represenation is still
  5842 bogus);
  5843 
  5844 
  5845 *** ZF ***
  5846 
  5847 * ZF: simplification automatically cancels common terms in arithmetic
  5848 expressions over nat and int;
  5849 
  5850 * ZF: new treatment of nat to minimize type-checking: all operators
  5851 coerce their operands to a natural number using the function natify,
  5852 making the algebraic laws unconditional;
  5853 
  5854 * ZF: as above, for int: operators coerce their operands to an integer
  5855 using the function intify;
  5856 
  5857 * ZF: the integer library now contains many of the usual laws for the
  5858 orderings, including $<=, and monotonicity laws for $+ and $*;
  5859 
  5860 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5861 simplification;
  5862 
  5863 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5864 to the simplifier and classical reasoner simultaneously;
  5865 
  5866 
  5867 *** General ***
  5868 
  5869 * Provers: blast_tac now handles actual object-logic rules as
  5870 assumptions; note that auto_tac uses blast_tac internally as well;
  5871 
  5872 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5873 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5874 
  5875 * Provers: delrules now handles destruct rules as well (no longer need
  5876 explicit make_elim);
  5877 
  5878 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5879   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5880 use instead the strong form,
  5881   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5882 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5883 from destruct-rules;
  5884 
  5885 * Provers: Simplifier.easy_setup provides a fast path to basic
  5886 Simplifier setup for new object-logics;
  5887 
  5888 * Pure: AST translation rules no longer require constant head on LHS;
  5889 
  5890 * Pure: improved name spaces: ambiguous output is qualified; support
  5891 for hiding of names;
  5892 
  5893 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5894 XSYMBOL_HOME; no longer need to do manual configuration in most
  5895 situations;
  5896 
  5897 * system: compression of ML heaps images may now be controlled via -c
  5898 option of isabelle and isatool usedir (currently only observed by
  5899 Poly/ML);
  5900 
  5901 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5902 useful for remote X11);
  5903 
  5904 * system: provide TAGS file for Isabelle sources;
  5905 
  5906 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5907 order;
  5908 
  5909 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5910 timing flag supersedes proof_timing and Toplevel.trace;
  5911 
  5912 * ML: new combinators |>> and |>>> for incremental transformations
  5913 with secondary results (e.g. certain theory extensions):
  5914 
  5915 * ML: PureThy.add_defs gets additional argument to indicate potential
  5916 overloading (usually false);
  5917 
  5918 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5919 results;
  5920 
  5921 
  5922 
  5923 New in Isabelle99 (October 1999)
  5924 --------------------------------
  5925 
  5926 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5927 
  5928 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5929 are no longer simplified.  (This allows the simplifier to unfold recursive
  5930 functional programs.)  To restore the old behaviour, declare
  5931 
  5932     Delcongs [if_weak_cong];
  5933 
  5934 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5935 complement;
  5936 
  5937 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5938 
  5939 * HOL/datatype: mutual_induct_tac no longer exists --
  5940   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5941 
  5942 * HOL/typedef: fixed type inference for representing set; type
  5943 arguments now have to occur explicitly on the rhs as type constraints;
  5944 
  5945 * ZF: The con_defs part of an inductive definition may no longer refer
  5946 to constants declared in the same theory;
  5947 
  5948 * HOL, ZF: the function mk_cases, generated by the inductive
  5949 definition package, has lost an argument.  To simplify its result, it
  5950 uses the default simpset instead of a supplied list of theorems.
  5951 
  5952 * HOL/List: the constructors of type list are now Nil and Cons;
  5953 
  5954 * Simplifier: the type of the infix ML functions
  5955         setSSolver addSSolver setSolver addSolver
  5956 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5957 for packaging solvers. A solver is created via
  5958         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5959 where the string argument is only a comment.
  5960 
  5961 
  5962 *** Proof tools ***
  5963 
  5964 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5965 decision procedure for linear arithmetic. Currently it is used for
  5966 types `nat', `int', and `real' in HOL (see below); it can, should and
  5967 will be instantiated for other types and logics as well.
  5968 
  5969 * The simplifier now accepts rewrite rules with flexible heads, eg
  5970      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5971   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5972   matching.
  5973 
  5974 
  5975 *** General ***
  5976 
  5977 * New Isabelle/Isar subsystem provides an alternative to traditional
  5978 tactical theorem proving; together with the ProofGeneral/isar user
  5979 interface it offers an interactive environment for developing human
  5980 readable proof documents (Isar == Intelligible semi-automated
  5981 reasoning); for further information see isatool doc isar-ref,
  5982 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5983 
  5984 * improved and simplified presentation of theories: better HTML markup
  5985 (including colors), graph views in several sizes; isatool usedir now
  5986 provides a proper interface for user theories (via -P option); actual
  5987 document preparation based on (PDF)LaTeX is available as well (for
  5988 new-style theories only); see isatool doc system for more information;
  5989 
  5990 * native support for Proof General, both for classic Isabelle and
  5991 Isabelle/Isar;
  5992 
  5993 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5994 using the graph browser tool;
  5995 
  5996 * Isabelle manuals now also available as PDF;
  5997 
  5998 * theory loader rewritten from scratch (may not be fully
  5999 bug-compatible); old loadpath variable has been replaced by show_path,
  6000 add_path, del_path, reset_path functions; new operations such as
  6001 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6002 isatool doc ref);
  6003 
  6004 * improved isatool install: option -k creates KDE application icon,
  6005 option -p DIR installs standalone binaries;
  6006 
  6007 * added ML_PLATFORM setting (useful for cross-platform installations);
  6008 more robust handling of platform specific ML images for SML/NJ;
  6009 
  6010 * the settings environment is now statically scoped, i.e. it is never
  6011 created again in sub-processes invoked from isabelle, isatool, or
  6012 Isabelle;
  6013 
  6014 * path element specification '~~' refers to '$ISABELLE_HOME';
  6015 
  6016 * in locales, the "assumes" and "defines" parts may be omitted if
  6017 empty;
  6018 
  6019 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  6020 long arrows);
  6021 
  6022 * new print_mode "HTML";
  6023 
  6024 * new flag show_tags controls display of tags of theorems (which are
  6025 basically just comments that may be attached by some tools);
  6026 
  6027 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  6028 mode and goal output format:
  6029 
  6030 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  6031 244c244
  6032 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  6033 ---
  6034 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  6035 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  6036 181c181
  6037 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  6038 ---
  6039 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  6040 
  6041 * function bind_thms stores lists of theorems (cf. bind_thm);
  6042 
  6043 * new shorthand tactics ftac, eatac, datac, fatac;
  6044 
  6045 * qed (and friends) now accept "" as result name; in that case the
  6046 theorem is not stored, but proper checks and presentation of the
  6047 result still apply;
  6048 
  6049 * theorem database now also indexes constants "Trueprop", "all",
  6050 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  6051 
  6052 
  6053 *** HOL ***
  6054 
  6055 ** HOL arithmetic **
  6056 
  6057 * There are now decision procedures for linear arithmetic over nat and
  6058 int:
  6059 
  6060 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  6061 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  6062 are treated as atomic; subformulae not involving type `nat' or `int'
  6063 are ignored; quantified subformulae are ignored unless they are
  6064 positive universal or negative existential. The tactic has to be
  6065 invoked by hand and can be a little bit slow. In particular, the
  6066 running time is exponential in the number of occurrences of `min' and
  6067 `max', and `-' on `nat'.
  6068 
  6069 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  6070 (negated) (in)equalities among the premises and the conclusion into
  6071 account (i.e. no compound formulae) and does not know about `min' and
  6072 `max', and `-' on `nat'. It is fast and is used automatically by the
  6073 simplifier.
  6074 
  6075 NB: At the moment, these decision procedures do not cope with mixed
  6076 nat/int formulae where the two parts interact, such as `m < n ==>
  6077 int(m) < int(n)'.
  6078 
  6079 * HOL/Numeral provides a generic theory of numerals (encoded
  6080 efficiently as bit strings); setup for types nat/int/real is in place;
  6081 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  6082 int, existing theories and proof scripts may require a few additional
  6083 type constraints;
  6084 
  6085 * integer division and remainder can now be performed on constant
  6086 arguments;
  6087 
  6088 * many properties of integer multiplication, division and remainder
  6089 are now available;
  6090 
  6091 * An interface to the Stanford Validity Checker (SVC) is available through the
  6092 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  6093 are proved automatically.  SVC must be installed separately, and its results
  6094 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  6095 invocation of the underlying oracle).  For SVC see
  6096   http://verify.stanford.edu/SVC
  6097 
  6098 * IsaMakefile: the HOL-Real target now builds an actual image;
  6099 
  6100 
  6101 ** HOL misc **
  6102 
  6103 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  6104 (in Isabelle/Isar) -- by Gertrud Bauer;
  6105 
  6106 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  6107 analysis for assembly languages with subtypes;
  6108 
  6109 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  6110 -- avoids syntactic ambiguities and treats state, transition, and
  6111 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  6112 changed syntax and (many) tactics;
  6113 
  6114 * HOL/inductive: Now also handles more general introduction rules such
  6115   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  6116   theorems are now maintained within the theory (maintained via the
  6117   "mono" attribute);
  6118 
  6119 * HOL/datatype: Now also handles arbitrarily branching datatypes
  6120   (using function types) such as
  6121 
  6122   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  6123 
  6124 * HOL/record: record_simproc (part of the default simpset) takes care
  6125 of selectors applied to updated records; record_split_tac is no longer
  6126 part of the default claset; update_defs may now be removed from the
  6127 simpset in many cases; COMPATIBILITY: old behavior achieved by
  6128 
  6129   claset_ref () := claset() addSWrapper record_split_wrapper;
  6130   Delsimprocs [record_simproc]
  6131 
  6132 * HOL/typedef: fixed type inference for representing set; type
  6133 arguments now have to occur explicitly on the rhs as type constraints;
  6134 
  6135 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  6136 names rather than an ML expression;
  6137 
  6138 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  6139 supplied later.  Program schemes can be defined, such as
  6140     "While B C s = (if B s then While B C (C s) else s)"
  6141 where the well-founded relation can be chosen after B and C have been given.
  6142 
  6143 * HOL/List: the constructors of type list are now Nil and Cons;
  6144 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  6145 course, ML tools referring to List.list.op # etc. have to be adapted;
  6146 
  6147 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  6148 disabled by default; run isabelle with option -m HOL to get back to
  6149 the original Gordon/HOL-style output;
  6150 
  6151 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  6152 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  6153 
  6154 * HOL basic syntax simplified (more orthogonal): all variants of
  6155 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  6156 Eps operator is provided as well: "SOME x. P[x]";
  6157 
  6158 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  6159 
  6160 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  6161 thus available for user theories;
  6162 
  6163 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  6164 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  6165 time;
  6166 
  6167 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  6168 several times and then mp;
  6169 
  6170 
  6171 *** LK ***
  6172 
  6173 * the notation <<...>> is now available as a notation for sequences of
  6174 formulas;
  6175 
  6176 * the simplifier is now installed
  6177 
  6178 * the axiom system has been generalized (thanks to Soren Heilmann)
  6179 
  6180 * the classical reasoner now has a default rule database
  6181 
  6182 
  6183 *** ZF ***
  6184 
  6185 * new primrec section allows primitive recursive functions to be given
  6186 directly (as in HOL) over datatypes and the natural numbers;
  6187 
  6188 * new tactics induct_tac and exhaust_tac for induction (or case
  6189 analysis) over datatypes and the natural numbers;
  6190 
  6191 * the datatype declaration of type T now defines the recursor T_rec;
  6192 
  6193 * simplification automatically does freeness reasoning for datatype
  6194 constructors;
  6195 
  6196 * automatic type-inference, with AddTCs command to insert new
  6197 type-checking rules;
  6198 
  6199 * datatype introduction rules are now added as Safe Introduction rules
  6200 to the claset;
  6201 
  6202 * the syntax "if P then x else y" is now available in addition to
  6203 if(P,x,y);
  6204 
  6205 
  6206 *** Internal programming interfaces ***
  6207 
  6208 * tuned simplifier trace output; new flag debug_simp;
  6209 
  6210 * structures Vartab / Termtab (instances of TableFun) offer efficient
  6211 tables indexed by indexname_ord / term_ord (compatible with aconv);
  6212 
  6213 * AxClass.axclass_tac lost the theory argument;
  6214 
  6215 * tuned current_goals_markers semantics: begin / end goal avoids
  6216 printing empty lines;
  6217 
  6218 * removed prs and prs_fn hook, which was broken because it did not
  6219 include \n in its semantics, forcing writeln to add one
  6220 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  6221 string -> unit if you really want to output text without newline;
  6222 
  6223 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  6224 plain output, interface builders may have to enable 'isabelle_font'
  6225 mode to get Isabelle font glyphs as before;
  6226 
  6227 * refined token_translation interface; INCOMPATIBILITY: output length
  6228 now of type real instead of int;
  6229 
  6230 * theory loader actions may be traced via new ThyInfo.add_hook
  6231 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  6232 your own database of information attached to *whole* theories -- as
  6233 opposed to intra-theory data slots offered via TheoryDataFun;
  6234