NEWS
author wenzelm
Thu May 27 17:41:27 2010 +0200 (2010-05-27)
changeset 37145 01aa36932739
parent 37144 fd6308b4df72
child 37146 f652333bbf8e
permissions -rw-r--r--
renamed structure TypeInfer to Type_Infer, keeping the old name as legacy alias for some time;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2009-2 (June 2010)
     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 * List membership infix mem operation is only an input abbreviation.
   147 INCOMPATIBILITY.
   148 
   149 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   150 for future developements; former Library/Word.thy is still present in
   151 the AFP entry RSAPPS.
   152 
   153 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   154 longer shadowed.  INCOMPATIBILITY.
   155 
   156 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   157 INCOMPATIBILITY.
   158 
   159 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   160 INCOMPATIBILITY.
   161 
   162 * Dropped normalizing_semiring etc; use the facts in semiring classes
   163 instead.  INCOMPATIBILITY.
   164 
   165 * Dropped several real-specific versions of lemmas about floor and
   166 ceiling; use the generic lemmas from Archimedean_Field.thy instead.
   167 INCOMPATIBILITY.
   168 
   169   floor_number_of_eq         ~> floor_number_of
   170   le_floor_eq_number_of      ~> number_of_le_floor
   171   le_floor_eq_zero           ~> zero_le_floor
   172   le_floor_eq_one            ~> one_le_floor
   173   floor_less_eq_number_of    ~> floor_less_number_of
   174   floor_less_eq_zero         ~> floor_less_zero
   175   floor_less_eq_one          ~> floor_less_one
   176   less_floor_eq_number_of    ~> number_of_less_floor
   177   less_floor_eq_zero         ~> zero_less_floor
   178   less_floor_eq_one          ~> one_less_floor
   179   floor_le_eq_number_of      ~> floor_le_number_of
   180   floor_le_eq_zero           ~> floor_le_zero
   181   floor_le_eq_one            ~> floor_le_one
   182   floor_subtract_number_of   ~> floor_diff_number_of
   183   floor_subtract_one         ~> floor_diff_one
   184   ceiling_number_of_eq       ~> ceiling_number_of
   185   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   186   ceiling_le_zero_eq         ~> ceiling_le_zero
   187   ceiling_le_eq_one          ~> ceiling_le_one
   188   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   189   less_ceiling_eq_zero       ~> zero_less_ceiling
   190   less_ceiling_eq_one        ~> one_less_ceiling
   191   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   192   ceiling_less_eq_zero       ~> ceiling_less_zero
   193   ceiling_less_eq_one        ~> ceiling_less_one
   194   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   195   le_ceiling_eq_zero         ~> zero_le_ceiling
   196   le_ceiling_eq_one          ~> one_le_ceiling
   197   ceiling_subtract_number_of ~> ceiling_diff_number_of
   198   ceiling_subtract_one       ~> ceiling_diff_one
   199 
   200 * Theory "Finite_Set": various folding_XXX locales facilitate the
   201 application of the various fold combinators on finite sets.
   202 
   203 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   204 provides abstract red-black tree type which is backed by "RBT_Impl" as
   205 implementation.  INCOMPATIBILTY.
   206 
   207 * Command 'typedef' now works within a local theory context -- without
   208 introducing dependencies on parameters or assumptions, which is not
   209 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   210 contain multiple interpretations of local typedefs (with different
   211 non-emptiness proofs), even in a global theory context.
   212 
   213 * Theory Library/Coinductive_List has been removed -- superseded by
   214 AFP/thys/Coinductive.
   215 
   216 * Theory PReal, including the type "preal" and related operations, has
   217 been removed.  INCOMPATIBILITY.
   218 
   219 * Split off theory Big_Operators containing setsum, setprod, Inf_fin,
   220 Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   221 
   222 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   223 "Int" etc.  INCOMPATIBILITY.
   224 
   225 * Constant Rat.normalize needs to be qualified.  Minor
   226 INCOMPATIBILITY.
   227 
   228 * New set of rules "ac_simps" provides combined assoc / commute
   229 rewrites for all interpretations of the appropriate generic locales.
   230 
   231 * Renamed theory "OrderedGroup" to "Groups" and split theory
   232 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   233 appropriate and more consistent names suitable for name prefixes
   234 within the HOL theories.  INCOMPATIBILITY.
   235 
   236 * Some generic constants have been put to appropriate theories:
   237   - less_eq, less: Orderings
   238   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   239   - inverse, divide: Rings
   240 INCOMPATIBILITY.
   241 
   242 * More consistent naming of type classes involving orderings (and
   243 lattices):
   244 
   245     lower_semilattice                   ~> semilattice_inf
   246     upper_semilattice                   ~> semilattice_sup
   247 
   248     dense_linear_order                  ~> dense_linorder
   249 
   250     pordered_ab_group_add               ~> ordered_ab_group_add
   251     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   252     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   253     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   254     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   255     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   256     pordered_cancel_semiring            ~> ordered_cancel_semiring
   257     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   258     pordered_comm_ring                  ~> ordered_comm_ring
   259     pordered_comm_semiring              ~> ordered_comm_semiring
   260     pordered_ring                       ~> ordered_ring
   261     pordered_ring_abs                   ~> ordered_ring_abs
   262     pordered_semiring                   ~> ordered_semiring
   263 
   264     ordered_ab_group_add                ~> linordered_ab_group_add
   265     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   266     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   267     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   268     ordered_field                       ~> linordered_field
   269     ordered_field_no_lb                 ~> linordered_field_no_lb
   270     ordered_field_no_ub                 ~> linordered_field_no_ub
   271     ordered_field_dense_linear_order    ~> dense_linordered_field
   272     ordered_idom                        ~> linordered_idom
   273     ordered_ring                        ~> linordered_ring
   274     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   275     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   276     ordered_ring_strict                 ~> linordered_ring_strict
   277     ordered_semidom                     ~> linordered_semidom
   278     ordered_semiring                    ~> linordered_semiring
   279     ordered_semiring_1                  ~> linordered_semiring_1
   280     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   281     ordered_semiring_strict             ~> linordered_semiring_strict
   282 
   283   The following slightly odd type classes have been moved to a
   284   separate theory Library/Lattice_Algebras.thy:
   285 
   286     lordered_ab_group_add               ~> lattice_ab_group_add
   287     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   288     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   289     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   290     lordered_ring                       ~> lattice_ring
   291 
   292 INCOMPATIBILITY.
   293 
   294 * Refined field classes:
   295   - classes division_ring_inverse_zero, field_inverse_zero,
   296     linordered_field_inverse_zero include rule inverse 0 = 0 --
   297     subsumes former division_by_zero class;
   298   - numerous lemmas have been ported from field to division_ring.
   299 INCOMPATIBILITY.
   300 
   301 * Refined algebra theorem collections:
   302   - dropped theorem group group_simps, use algebra_simps instead;
   303   - dropped theorem group ring_simps, use field_simps instead;
   304   - proper theorem collection field_simps subsumes former theorem
   305     groups field_eq_simps and field_simps;
   306   - dropped lemma eq_minus_self_iff which is a duplicate for
   307     equal_neg_zero.
   308 INCOMPATIBILITY.
   309 
   310 * Theory Finite_Set and List: some lemmas have been generalized from
   311 sets to lattices:
   312 
   313   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   314   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   315   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   316   union_Union_fold_union        ~> sup_Sup_fold_sup
   317   Inter_fold_inter              ~> Inf_fold_inf
   318   Union_fold_union              ~> Sup_fold_sup
   319   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   320   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   321   INTER_fold_inter              ~> INFI_fold_inf
   322   UNION_fold_union              ~> SUPR_fold_sup
   323 
   324 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   325 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   326 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   327 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   328 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   329 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   330 
   331 * HOLogic.strip_psplit: types are returned in syntactic order, similar
   332 to other strip and tuple operations.  INCOMPATIBILITY.
   333 
   334 * Reorganized theory Multiset: swapped notation of pointwise and
   335 multiset order:
   336   - pointwise ordering is instance of class order with standard syntax
   337     <= and <;
   338   - multiset ordering has syntax <=# and <#; partial order properties
   339     are provided by means of interpretation with prefix
   340     multiset_order;
   341   - less duplication, less historical organization of sections,
   342     conversion from associations lists to multisets, rudimentary code
   343     generation;
   344   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   345     if needed.
   346 Renamed:
   347   multiset_eq_conv_count_eq -> multiset_ext_iff
   348   multi_count_ext -> multiset_ext
   349   diff_union_inverse2 -> diff_union_cancelR
   350 INCOMPATIBILITY.
   351 
   352 * Theory Permutation: replaced local "remove" by List.remove1.
   353 
   354 * Code generation: ML and OCaml code is decorated with signatures.
   355 
   356 * Theory List: added transpose.
   357 
   358 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   359 clash with new theory Quotient in Main HOL.
   360 
   361 * Library/Nat_Bijection.thy is a collection of bijective functions
   362 between nat and other types, which supersedes the older libraries
   363 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   364 
   365   Constants:
   366   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   367   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   368   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   369   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   370   Countable.pair_encode           ~> prod_encode
   371   NatIso.prod2nat                 ~> prod_encode
   372   NatIso.nat2prod                 ~> prod_decode
   373   NatIso.sum2nat                  ~> sum_encode
   374   NatIso.nat2sum                  ~> sum_decode
   375   NatIso.list2nat                 ~> list_encode
   376   NatIso.nat2list                 ~> list_decode
   377   NatIso.set2nat                  ~> set_encode
   378   NatIso.nat2set                  ~> set_decode
   379 
   380   Lemmas:
   381   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   382   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   383   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   384   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   385   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   386   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   387   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   388   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   389   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   390   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   391   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   392   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   393   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   394 
   395 * Sledgehammer:
   396   - Renamed ATP commands:
   397     atp_info     ~> sledgehammer running_atps
   398     atp_kill     ~> sledgehammer kill_atps
   399     atp_messages ~> sledgehammer messages
   400     atp_minimize ~> sledgehammer minimize
   401     print_atps   ~> sledgehammer available_atps
   402     INCOMPATIBILITY.
   403   - Added user's manual ("isabelle doc sledgehammer").
   404   - Added option syntax and "sledgehammer_params" to customize
   405     Sledgehammer's behavior.  See the manual for details.
   406   - Modified the Isar proof reconstruction code so that it produces
   407     direct proofs rather than proofs by contradiction.  (This feature
   408     is still experimental.)
   409   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   410     full-typed mode.
   411   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   412 
   413 * Nitpick:
   414   - Added and implemented "binary_ints" and "bits" options.
   415   - Added "std" option and implemented support for nonstandard models.
   416   - Added and implemented "finitize" option to improve the precision
   417     of infinite datatypes based on a monotonicity analysis.
   418   - Added support for quotient types.
   419   - Added support for "specification" and "ax_specification"
   420     constructs.
   421   - Added support for local definitions (for "function" and
   422     "termination" proofs).
   423   - Added support for term postprocessors.
   424   - Optimized "Multiset.multiset" and "FinFun.finfun".
   425   - Improved efficiency of "destroy_constrs" optimization.
   426   - Fixed soundness bugs related to "destroy_constrs" optimization and
   427     record getters.
   428   - Fixed soundness bug related to higher-order constructors
   429   - Improved precision of set constructs.
   430   - Added cache to speed up repeated Kodkod invocations on the same
   431     problems.
   432   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   433     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   434     "SAT4J_Light".  INCOMPATIBILITY.
   435   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   436     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   437 
   438 
   439 *** HOLCF ***
   440 
   441 * Variable names in lemmas generated by the domain package have
   442 changed; the naming scheme is now consistent with the HOL datatype
   443 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   444 
   445 * The domain package no longer defines the function "foo_copy" for
   446 recursive domain "foo".  The reach lemma is now stated directly in
   447 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   448 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   449 
   450 * Most definedness lemmas generated by the domain package (previously
   451 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   452 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   453 Proof scripts that used definedness lemmas as intro rules may break,
   454 potential INCOMPATIBILITY.
   455 
   456 * Induction and casedist rules generated by the domain package now
   457 declare proper case_names (one called "bottom", and one named for each
   458 constructor).  INCOMPATIBILITY.
   459 
   460 * For mutually-recursive domains, separate "reach" and "take_lemma"
   461 rules are generated for each domain, INCOMPATIBILITY.
   462 
   463   foo_bar.reach       ~> foo.reach  bar.reach
   464   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   465 
   466 * Some lemmas generated by the domain package have been renamed for
   467 consistency with the datatype package, INCOMPATIBILITY.
   468 
   469   foo.ind        ~> foo.induct
   470   foo.finite_ind ~> foo.finite_induct
   471   foo.coind      ~> foo.coinduct
   472   foo.casedist   ~> foo.exhaust
   473   foo.exhaust    ~> foo.nchotomy
   474 
   475 * For consistency with other definition packages, the fixrec package
   476 now generates qualified theorem names, INCOMPATIBILITY.
   477 
   478   foo_simps  ~> foo.simps
   479   foo_unfold ~> foo.unfold
   480   foo_induct ~> foo.induct
   481 
   482 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   483 method and internal fixrec proofs now use the default simpset instead.
   484 INCOMPATIBILITY.
   485 
   486 * The "contlub" predicate has been removed.  Proof scripts should use
   487 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   488 
   489 * The "admw" predicate has been removed, INCOMPATIBILITY.
   490 
   491 * The constants cpair, cfst, and csnd have been removed in favor of
   492 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   493 
   494 
   495 *** ML ***
   496 
   497 * Renamed some important ML structures, while keeping the old names
   498 for some time as aliases within the structure Legacy:
   499 
   500   OuterKeyword  ~>  Keyword
   501   OuterLex      ~>  Token
   502   OuterParse    ~>  Parse
   503   OuterSyntax   ~>  Outer_Syntax
   504   SpecParse     ~>  Parse_Spec
   505   TypeInfer     ~>  Type_Infer
   506 
   507 Note that "open Legacy" simplifies porting of sources, but forgetting
   508 to remove it again will complicate porting again in the future.
   509 
   510 * Most operations that refer to a global context are named
   511 accordingly, e.g. Simplifier.global_context or
   512 ProofContext.init_global.  There are some situations where a global
   513 context actually works, but under normal circumstances one needs to
   514 pass the proper local context through the code!
   515 
   516 * Discontinued old TheoryDataFun with its copy/init operation -- data
   517 needs to be pure.  Functor Theory_Data_PP retains the traditional
   518 Pretty.pp argument to merge, which is absent in the standard
   519 Theory_Data version.
   520 
   521 * Antiquotations for basic formal entities:
   522 
   523     @{class NAME}         -- type class
   524     @{class_syntax NAME}  -- syntax representation of the above
   525 
   526     @{type_name NAME}     -- logical type
   527     @{type_abbrev NAME}   -- type abbreviation
   528     @{nonterminal NAME}   -- type of concrete syntactic category
   529     @{type_syntax NAME}   -- syntax representation of any of the above
   530 
   531     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   532     @{const_abbrev NAME}  -- abbreviated constant
   533     @{const_syntax NAME}  -- syntax representation of any of the above
   534 
   535 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   536 syntax constant (cf. 'syntax' command).
   537 
   538 * Antiquotation @{make_string} inlines a function to print arbitrary
   539 values similar to the ML toplevel.  The result is compiler dependent
   540 and may fall back on "?" in certain situations.
   541 
   542 * Sorts.certify_sort and derived "cert" operations for types and terms
   543 no longer minimize sorts.  Thus certification at the boundary of the
   544 inference kernel becomes invariant under addition of class relations,
   545 which is an important monotonicity principle.  Sorts are now minimized
   546 in the syntax layer only, at the boundary between the end-user and the
   547 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   548 explicitly in rare situations.
   549 
   550 * Renamed old-style Drule.standard to Drule.export_without_context, to
   551 emphasize that this is in no way a standard operation.
   552 INCOMPATIBILITY.
   553 
   554 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   555 usual for resolution.  Rare INCOMPATIBILITY.
   556 
   557 * Renamed varify/unvarify operations to varify_global/unvarify_global
   558 to emphasize that these only work in a global situation (which is
   559 quite rare).
   560 
   561 * Configuration options now admit dynamic default values, depending on
   562 the context or even global references.
   563 
   564 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   565 uses an efficient external library if available (for Poly/ML).
   566 
   567 * Curried take and drop in library.ML; negative length is interpreted
   568 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   569 
   570 
   571 *** System ***
   572 
   573 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   574 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   575 proof terms are enabled unconditionally in the new HOL-Proofs image.
   576 
   577 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   578 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   579 respectively.
   580 
   581 * Old lib/scripts/polyml-platform is superseded by the
   582 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   583 variant, even on a 64 bit machine.  The following example setting
   584 prefers 64 bit if available:
   585 
   586   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   587 
   588 
   589 
   590 New in Isabelle2009-1 (December 2009)
   591 -------------------------------------
   592 
   593 *** General ***
   594 
   595 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   596 one backslash should be used, even in ML sources.
   597 
   598 
   599 *** Pure ***
   600 
   601 * Locale interpretation propagates mixins along the locale hierarchy.
   602 The currently only available mixins are the equations used to map
   603 local definitions to terms of the target domain of an interpretation.
   604 
   605 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   606 loc" to print all interpretations of locale "loc" in the theory.
   607 Interpretations in proofs are not shown.
   608 
   609 * Thoroughly revised locales tutorial.  New section on conditional
   610 interpretation.
   611 
   612 * On instantiation of classes, remaining undefined class parameters
   613 are formally declared.  INCOMPATIBILITY.
   614 
   615 
   616 *** Document preparation ***
   617 
   618 * New generalized style concept for printing terms: @{foo (style) ...}
   619 instead of @{foo_style style ...}  (old form is still retained for
   620 backward compatibility).  Styles can be also applied for
   621 antiquotations prop, term_type and typeof.
   622 
   623 
   624 *** HOL ***
   625 
   626 * New proof method "smt" for a combination of first-order logic with
   627 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   628 fixed-size bitvectors; there is also basic support for higher-order
   629 features (esp. lambda abstractions).  It is an incomplete decision
   630 procedure based on external SMT solvers using the oracle mechanism;
   631 for the SMT solver Z3, this method is proof-producing.  Certificates
   632 are provided to avoid calling the external solvers solely for
   633 re-checking proofs.  Due to a remote SMT service there is no need for
   634 installing SMT solvers locally.  See src/HOL/SMT.
   635 
   636 * New commands to load and prove verification conditions generated by
   637 the Boogie program verifier or derived systems (e.g. the Verifying C
   638 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   639 
   640 * New counterexample generator tool 'nitpick' based on the Kodkod
   641 relational model finder.  See src/HOL/Tools/Nitpick and
   642 src/HOL/Nitpick_Examples.
   643 
   644 * New commands 'code_pred' and 'values' to invoke the predicate
   645 compiler and to enumerate values of inductive predicates.
   646 
   647 * A tabled implementation of the reflexive transitive closure.
   648 
   649 * New implementation of quickcheck uses generic code generator;
   650 default generators are provided for all suitable HOL types, records
   651 and datatypes.  Old quickcheck can be re-activated importing theory
   652 Library/SML_Quickcheck.
   653 
   654 * New testing tool Mirabelle for automated proof tools.  Applies
   655 several tools and tactics like sledgehammer, metis, or quickcheck, to
   656 every proof step in a theory.  To be used in batch mode via the
   657 "mirabelle" utility.
   658 
   659 * New proof method "sos" (sum of squares) for nonlinear real
   660 arithmetic (originally due to John Harison). It requires theory
   661 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   662 works well in practice on quantifier-free real arithmetic with +, -,
   663 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   664 inequalities between polynomials.  It makes use of external
   665 semidefinite programming solvers.  Method "sos" generates a
   666 certificate that can be pasted into the proof thus avoiding the need
   667 to call an external tool every time the proof is checked.  See
   668 src/HOL/Library/Sum_Of_Squares.
   669 
   670 * New method "linarith" invokes existing linear arithmetic decision
   671 procedure only.
   672 
   673 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   674 
   675 * New Sledgehammer option "Full Types" in Proof General settings menu.
   676 Causes full type information to be output to the ATPs.  This slows
   677 ATPs down considerably but eliminates a source of unsound "proofs"
   678 that fail later.
   679 
   680 * New method "metisFT": A version of metis that uses full type
   681 information in order to avoid failures of proof reconstruction.
   682 
   683 * New evaluator "approximate" approximates an real valued term using
   684 the same method as the approximation method.
   685 
   686 * Method "approximate" now supports arithmetic expressions as
   687 boundaries of intervals and implements interval splitting and Taylor
   688 series expansion.
   689 
   690 * ML antiquotation @{code_datatype} inserts definition of a datatype
   691 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   692 
   693 * New theory SupInf of the supremum and infimum operators for sets of
   694 reals.
   695 
   696 * New theory Probability, which contains a development of measure
   697 theory, eventually leading to Lebesgue integration and probability.
   698 
   699 * Extended Multivariate Analysis to include derivation and Brouwer's
   700 fixpoint theorem.
   701 
   702 * Reorganization of number theory, INCOMPATIBILITY:
   703   - new number theory development for nat and int, in theories Divides
   704     and GCD as well as in new session Number_Theory
   705   - some constants and facts now suffixed with _nat and _int
   706     accordingly
   707   - former session NumberTheory now named Old_Number_Theory, including
   708     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   709   - moved theory Pocklington from src/HOL/Library to
   710     src/HOL/Old_Number_Theory
   711 
   712 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   713 lcm of finite and infinite sets. It is shown that they form a complete
   714 lattice.
   715 
   716 * Class semiring_div requires superclass no_zero_divisors and proof of
   717 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   718 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   719 generalized to class semiring_div, subsuming former theorems
   720 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   721 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   722 INCOMPATIBILITY.
   723 
   724 * Refinements to lattice classes and sets:
   725   - less default intro/elim rules in locale variant, more default
   726     intro/elim rules in class variant: more uniformity
   727   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   728     le_inf_iff
   729   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   730     sup_aci)
   731   - renamed ACI to inf_sup_aci
   732   - new class "boolean_algebra"
   733   - class "complete_lattice" moved to separate theory
   734     "Complete_Lattice"; corresponding constants (and abbreviations)
   735     renamed and with authentic syntax:
   736     Set.Inf ~>    Complete_Lattice.Inf
   737     Set.Sup ~>    Complete_Lattice.Sup
   738     Set.INFI ~>   Complete_Lattice.INFI
   739     Set.SUPR ~>   Complete_Lattice.SUPR
   740     Set.Inter ~>  Complete_Lattice.Inter
   741     Set.Union ~>  Complete_Lattice.Union
   742     Set.INTER ~>  Complete_Lattice.INTER
   743     Set.UNION ~>  Complete_Lattice.UNION
   744   - authentic syntax for
   745     Set.Pow
   746     Set.image
   747   - mere abbreviations:
   748     Set.empty               (for bot)
   749     Set.UNIV                (for top)
   750     Set.inter               (for inf, formerly Set.Int)
   751     Set.union               (for sup, formerly Set.Un)
   752     Complete_Lattice.Inter  (for Inf)
   753     Complete_Lattice.Union  (for Sup)
   754     Complete_Lattice.INTER  (for INFI)
   755     Complete_Lattice.UNION  (for SUPR)
   756   - object-logic definitions as far as appropriate
   757 
   758 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   759 Un_subset_iff are explicitly deleted as default simp rules; then also
   760 their lattice counterparts le_inf_iff and le_sup_iff have to be
   761 deleted to achieve the desired effect.
   762 
   763 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   764 rules by default any longer; the same applies to min_max.inf_absorb1
   765 etc.  INCOMPATIBILITY.
   766 
   767 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   768 pred_set_conv by default.  INCOMPATIBILITY.
   769 
   770 * Power operations on relations and functions are now one dedicated
   771 constant "compow" with infix syntax "^^".  Power operation on
   772 multiplicative monoids retains syntax "^" and is now defined generic
   773 in class power.  INCOMPATIBILITY.
   774 
   775 * Relation composition "R O S" now has a more standard argument order:
   776 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   777 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   778 break, since the O_assoc rule was not rewritten like this.  Fix using
   779 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   780 
   781 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   782 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   783 INCOMPATIBILITY.
   784 
   785 * Most rules produced by inductive and datatype package have mandatory
   786 prefixes.  INCOMPATIBILITY.
   787 
   788 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   789 the attribute of the same name.  Each of the theorems in the list
   790 DERIV_intros assumes composition with an additional function and
   791 matches a variable to the derivative, which has to be solved by the
   792 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   793 of most elementary terms.  Former Maclauren.DERIV_tac and
   794 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   795 INCOMPATIBILITY.
   796 
   797 * Code generator attributes follow the usual underscore convention:
   798     code_unfold     replaces    code unfold
   799     code_post       replaces    code post
   800     etc.
   801   INCOMPATIBILITY.
   802 
   803 * Renamed methods:
   804     sizechange -> size_change
   805     induct_scheme -> induction_schema
   806   INCOMPATIBILITY.
   807 
   808 * Discontinued abbreviation "arbitrary" of constant "undefined".
   809 INCOMPATIBILITY, use "undefined" directly.
   810 
   811 * Renamed theorems:
   812     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   813     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   814     Suc_plus1 -> Suc_eq_plus1
   815     *anti_sym -> *antisym*
   816     vector_less_eq_def -> vector_le_def
   817   INCOMPATIBILITY.
   818 
   819 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   820 INCOMPATIBILITY.
   821 
   822 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   823 INCOMPATIBILITY.
   824 
   825 
   826 *** HOLCF ***
   827 
   828 * Theory Representable defines a class "rep" of domains that are
   829 representable (via an ep-pair) in the universal domain type "udom".
   830 Instances are provided for all type constructors defined in HOLCF.
   831 
   832 * The 'new_domain' command is a purely definitional version of the
   833 domain package, for representable domains.  Syntax is identical to the
   834 old domain package.  The 'new_domain' package also supports indirect
   835 recursion using previously-defined type constructors.  See
   836 src/HOLCF/ex/New_Domain.thy for examples.
   837 
   838 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   839 on the left-hand side of an equation, and then performs
   840 simplification.  Rewriting is done using rules declared with the
   841 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   842 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   843 
   844 * The pattern-match compiler in 'fixrec' can now handle constructors
   845 with HOL function types.  Pattern-match combinators for the Pair
   846 constructor are pre-configured.
   847 
   848 * The 'fixrec' package now produces better fixed-point induction rules
   849 for mutually-recursive definitions:  Induction rules have conclusions
   850 of the form "P foo bar" instead of "P <foo, bar>".
   851 
   852 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   853 been renamed to "below".  The name "below" now replaces "less" in many
   854 theorem names.  (Legacy theorem names using "less" are still supported
   855 as well.)
   856 
   857 * The 'fixrec' package now supports "bottom patterns".  Bottom
   858 patterns can be used to generate strictness rules, or to make
   859 functions more strict (much like the bang-patterns supported by the
   860 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   861 examples.
   862 
   863 
   864 *** ML ***
   865 
   866 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   867 errors and run-time exceptions, including detailed source positions.
   868 
   869 * Structure Name_Space (formerly NameSpace) now manages uniquely
   870 identified entries, with some additional information such as source
   871 position, logical grouping etc.
   872 
   873 * Theory and context data is now introduced by the simplified and
   874 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   875 to be pure, but the old TheoryDataFun for mutable data (with explicit
   876 copy operation) is still available for some time.
   877 
   878 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   879 provides a high-level programming interface to synchronized state
   880 variables with atomic update.  This works via pure function
   881 application within a critical section -- its runtime should be as
   882 short as possible; beware of deadlocks if critical code is nested,
   883 either directly or indirectly via other synchronized variables!
   884 
   885 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   886 wraps raw ML references, explicitly indicating their non-thread-safe
   887 behaviour.  The Isar toplevel keeps this structure open, to
   888 accommodate Proof General as well as quick and dirty interactive
   889 experiments with references.
   890 
   891 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   892 parallel tactical reasoning.
   893 
   894 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   895 are similar to SUBPROOF, but are slightly more flexible: only the
   896 specified parts of the subgoal are imported into the context, and the
   897 body tactic may introduce new subgoals and schematic variables.
   898 
   899 * Old tactical METAHYPS, which does not observe the proof context, has
   900 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   901 or Subgoal.FOCUS etc.
   902 
   903 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   904 functors have their own ML name space there is no point to mark them
   905 separately.)  Minor INCOMPATIBILITY.
   906 
   907 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   908 
   909 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   910 INCOMPATIBILITY.
   911 
   912 * Operations of structure Skip_Proof no longer require quick_and_dirty
   913 mode, which avoids critical setmp.
   914 
   915 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   916 combinators for "args".  INCOMPATIBILITY, need to use simplified
   917 Attrib/Method.setup introduced in Isabelle2009.
   918 
   919 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   920 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   921 last resort.  INCOMPATIBILITY.
   922 
   923 * Display.pretty_thm now requires a proper context (cf. former
   924 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   925 or even Display.pretty_thm_without_context as last resort.
   926 INCOMPATIBILITY.
   927 
   928 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   929 Syntax.pretty_typ/term directly, preferably with proper context
   930 instead of global theory.
   931 
   932 
   933 *** System ***
   934 
   935 * Further fine tuning of parallel proof checking, scales up to 8 cores
   936 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   937 usedir option -q.
   938 
   939 * Support for additional "Isabelle components" via etc/components, see
   940 also the system manual.
   941 
   942 * The isabelle makeall tool now operates on all components with
   943 IsaMakefile, not just hardwired "logics".
   944 
   945 * Removed "compress" option from isabelle-process and isabelle usedir;
   946 this is always enabled.
   947 
   948 * Discontinued support for Poly/ML 4.x versions.
   949 
   950 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   951 on a given logic image.  This requires the lighttpd webserver and is
   952 currently supported on Linux only.
   953 
   954 
   955 
   956 New in Isabelle2009 (April 2009)
   957 --------------------------------
   958 
   959 *** General ***
   960 
   961 * Simplified main Isabelle executables, with less surprises on
   962 case-insensitive file-systems (such as Mac OS).
   963 
   964   - The main Isabelle tool wrapper is now called "isabelle" instead of
   965     "isatool."
   966 
   967   - The former "isabelle" alias for "isabelle-process" has been
   968     removed (should rarely occur to regular users).
   969 
   970   - The former "isabelle-interface" and its alias "Isabelle" have been
   971     removed (interfaces are now regular Isabelle tools).
   972 
   973 Within scripts and make files, the Isabelle environment variables
   974 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   975 respectively.  (The latter are still available as legacy feature.)
   976 
   977 The old isabelle-interface wrapper could react in confusing ways if
   978 the interface was uninstalled or changed otherwise.  Individual
   979 interface tool configuration is now more explicit, see also the
   980 Isabelle system manual.  In particular, Proof General is now available
   981 via "isabelle emacs".
   982 
   983 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   984 purge installed copies of Isabelle executables and re-run "isabelle
   985 install -p ...", or use symlinks.
   986 
   987 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   988 old ~/isabelle, which was slightly non-standard and apt to cause
   989 surprises on case-insensitive file-systems (such as Mac OS).
   990 
   991 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   992 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   993 care is required when using older releases of Isabelle.  Note that
   994 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   995 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   996 
   997 * Proofs of fully specified statements are run in parallel on
   998 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   999 a regular 4-core machine, if the initial heap space is made reasonably
  1000 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1001 
  1002 * The main reference manuals ("isar-ref", "implementation", and
  1003 "system") have been updated and extended.  Formally checked references
  1004 as hyperlinks are now available uniformly.
  1005 
  1006 
  1007 *** Pure ***
  1008 
  1009 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1010 respects.  The most important changes are listed below.  See the
  1011 Tutorial on Locales ("locales" manual) for details.
  1012 
  1013 - In locale expressions, instantiation replaces renaming.  Parameters
  1014 must be declared in a for clause.  To aid compatibility with previous
  1015 parameter inheritance, in locale declarations, parameters that are not
  1016 'touched' (instantiation position "_" or omitted) are implicitly added
  1017 with their syntax at the beginning of the for clause.
  1018 
  1019 - Syntax from abbreviations and definitions in locales is available in
  1020 locale expressions and context elements.  The latter is particularly
  1021 useful in locale declarations.
  1022 
  1023 - More flexible mechanisms to qualify names generated by locale
  1024 expressions.  Qualifiers (prefixes) may be specified in locale
  1025 expressions, and can be marked as mandatory (syntax: "name!:") or
  1026 optional (syntax "name?:").  The default depends for plain "name:"
  1027 depends on the situation where a locale expression is used: in
  1028 commands 'locale' and 'sublocale' prefixes are optional, in
  1029 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1030 implicit qualifiers derived from the parameter names of a locale are
  1031 no longer generated.
  1032 
  1033 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1034 instantiation clause in "interpretation" and "interpret" (square
  1035 brackets) is no longer available.  Use locale expressions.
  1036 
  1037 - When converting proof scripts, mandatory qualifiers in
  1038 'interpretation' and 'interpret' should be retained by default, even
  1039 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1040 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1041 in locale expressions range over a single locale instance only.
  1042 
  1043 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1044 In existing theorem specifications replace the includes element by the
  1045 respective context elements of the included locale, omitting those
  1046 that are already present in the theorem specification.  Multiple
  1047 assume elements of a locale should be replaced by a single one
  1048 involving the locale predicate.  In the proof body, declarations (most
  1049 notably theorems) may be regained by interpreting the respective
  1050 locales in the proof context as required (command "interpret").
  1051 
  1052 If using "includes" in replacement of a target solely because the
  1053 parameter types in the theorem are not as general as in the target,
  1054 consider declaring a new locale with additional type constraints on
  1055 the parameters (context element "constrains").
  1056 
  1057 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1058 
  1059 - Locale interpretation commands no longer attempt to simplify goal.
  1060 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1061 methods intro_locales and unfold_locales to clarify.
  1062 
  1063 - Locale interpretation commands no longer accept interpretation
  1064 attributes.  INCOMPATIBILITY.
  1065 
  1066 * Class declaration: so-called "base sort" must not be given in import
  1067 list any longer, but is inferred from the specification.  Particularly
  1068 in HOL, write
  1069 
  1070     class foo = ...
  1071 
  1072 instead of
  1073 
  1074     class foo = type + ...
  1075 
  1076 * Class target: global versions of theorems stemming do not carry a
  1077 parameter prefix any longer.  INCOMPATIBILITY.
  1078 
  1079 * Class 'instance' command no longer accepts attached definitions.
  1080 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1081 
  1082 * Recovered hiding of consts, which was accidentally broken in
  1083 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1084 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1085 
  1086 * Slightly more coherent Pure syntax, with updated documentation in
  1087 isar-ref manual.  Removed locales meta_term_syntax and
  1088 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1089 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1090 directly in regular applications.
  1091 
  1092 * There is a new syntactic category "float_const" for signed decimal
  1093 fractions (e.g. 123.45 or -123.45).
  1094 
  1095 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1096 interface with 'setup' command instead.
  1097 
  1098 * Command 'local_setup' is similar to 'setup', but operates on a local
  1099 theory context.
  1100 
  1101 * The 'axiomatization' command now only works within a global theory
  1102 context.  INCOMPATIBILITY.
  1103 
  1104 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1105 hypotheses.  Sorts required in the course of reasoning need to be
  1106 covered by the constraints in the initial statement, completed by the
  1107 type instance information of the background theory.  Non-trivial sort
  1108 hypotheses, which rarely occur in practice, may be specified via
  1109 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1110 
  1111   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1112 
  1113 The result contains an implicit sort hypotheses as before --
  1114 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1115 normalization.
  1116 
  1117 * Generalized Isar history, with support for linear undo, direct state
  1118 addressing etc.
  1119 
  1120 * Changed defaults for unify configuration options:
  1121 
  1122   unify_trace_bound = 50 (formerly 25)
  1123   unify_search_bound = 60 (formerly 30)
  1124 
  1125 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1126 
  1127   a) On theory merge, the last set of code equations for a particular
  1128      constant is taken (in accordance with the policy applied by other
  1129      parts of the code generator framework).
  1130 
  1131   b) Code equations stemming from explicit declarations (e.g. code
  1132      attribute) gain priority over default code equations stemming
  1133      from definition, primrec, fun etc.
  1134 
  1135 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1136 
  1137 * Unified theorem tables for both code generators.  Thus [code
  1138 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1139 
  1140 * Command 'find_consts' searches for constants based on type and name
  1141 patterns, e.g.
  1142 
  1143     find_consts "_ => bool"
  1144 
  1145 By default, matching is against subtypes, but it may be restricted to
  1146 the whole type.  Searching by name is possible.  Multiple queries are
  1147 conjunctive and queries may be negated by prefixing them with a
  1148 hyphen:
  1149 
  1150     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1151 
  1152 * New 'find_theorems' criterion "solves" matches theorems that
  1153 directly solve the current goal (modulo higher-order unification).
  1154 
  1155 * Auto solve feature for main theorem statements: whenever a new goal
  1156 is stated, "find_theorems solves" is called; any theorems that could
  1157 solve the lemma directly are listed as part of the goal state.
  1158 Cf. associated options in Proof General Isabelle settings menu,
  1159 enabled by default, with reasonable timeout for pathological cases of
  1160 higher-order unification.
  1161 
  1162 
  1163 *** Document preparation ***
  1164 
  1165 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1166 demanding keyword 'by' and supporting the full method expression
  1167 syntax just like the Isar command 'by'.
  1168 
  1169 
  1170 *** HOL ***
  1171 
  1172 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1173 points Main and Complex_Main remain as before.
  1174 
  1175 * Logic image HOL-Plain provides a minimal HOL with the most important
  1176 tools available (inductive, datatype, primrec, ...).  This facilitates
  1177 experimentation and tool development.  Note that user applications
  1178 (and library theories) should never refer to anything below theory
  1179 Main, as before.
  1180 
  1181 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1182 experimentation due to shorter build times.
  1183 
  1184 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1185 were previously part of former HOL-Complex.  Entry point Hyperreal
  1186 remains valid, but theories formerly using Complex_Main should now use
  1187 new entry point Hypercomplex.
  1188 
  1189 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1190 Posix processes.  Avoids potentially expensive forking of the ML
  1191 process.  New thread-based implementation also works on non-Unix
  1192 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1193 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1194 commands are covered in the isar-ref manual.
  1195 
  1196 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1197 sledgehammer without local ATP installation (Vampire etc.). Other
  1198 provers may be included via suitable ML wrappers, see also
  1199 src/HOL/ATP_Linkup.thy.
  1200 
  1201 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1202 menu.
  1203 
  1204 * The metis method no longer fails because the theorem is too trivial
  1205 (contains the empty clause).
  1206 
  1207 * The metis method now fails in the usual manner, rather than raising
  1208 an exception, if it determines that it cannot prove the theorem.
  1209 
  1210 * Method "coherent" implements a prover for coherent logic (see also
  1211 src/Tools/coherent.ML).
  1212 
  1213 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1214 "undefined" is the right choice to replace "arbitrary", though
  1215 logically there is no difference.  INCOMPATIBILITY.
  1216 
  1217 * Command "value" now integrates different evaluation mechanisms.  The
  1218 result of the first successful evaluation mechanism is printed.  In
  1219 square brackets a particular named evaluation mechanisms may be
  1220 specified (currently, [SML], [code] or [nbe]).  See further
  1221 src/HOL/ex/Eval_Examples.thy.
  1222 
  1223 * Normalization by evaluation now allows non-leftlinear equations.
  1224 Declare with attribute [code nbe].
  1225 
  1226 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1227 as the structured Isar versions "cases" and "induct", cf. the
  1228 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1229 are now presented as a list of individual projections
  1230 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1231 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1232 rare situations a different rule is selected --- notably nested tuple
  1233 elimination instead of former prod.exhaust: use explicit (case_tac t
  1234 rule: prod.exhaust) here.
  1235 
  1236 * Attributes "cases", "induct", "coinduct" support "del" option.
  1237 
  1238 * Removed fact "case_split_thm", which duplicates "case_split".
  1239 
  1240 * The option datatype has been moved to a new theory Option.  Renamed
  1241 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1242 
  1243 * New predicate "strict_mono" classifies strict functions on partial
  1244 orders.  With strict functions on linear orders, reasoning about
  1245 (in)equalities is facilitated by theorems "strict_mono_eq",
  1246 "strict_mono_less_eq" and "strict_mono_less".
  1247 
  1248 * Some set operations are now proper qualified constants with
  1249 authentic syntax.  INCOMPATIBILITY:
  1250 
  1251     op Int ~>   Set.Int
  1252     op Un ~>    Set.Un
  1253     INTER ~>    Set.INTER
  1254     UNION ~>    Set.UNION
  1255     Inter ~>    Set.Inter
  1256     Union ~>    Set.Union
  1257     {} ~>       Set.empty
  1258     UNIV ~>     Set.UNIV
  1259 
  1260 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1261 theory Set.
  1262 
  1263 * Auxiliary class "itself" has disappeared -- classes without any
  1264 parameter are treated as expected by the 'class' command.
  1265 
  1266 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1267 
  1268 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1269 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1270 
  1271 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1272 method "approximation".  It proves formulas on real values by using
  1273 interval arithmetic.  In the formulas are also the transcendental
  1274 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1275 allowed. For examples see
  1276 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1277 
  1278 * Theory "Reflection" now resides in HOL/Library.
  1279 
  1280 * Entry point to Word library now simply named "Word".
  1281 INCOMPATIBILITY.
  1282 
  1283 * Made source layout more coherent with logical distribution
  1284 structure:
  1285 
  1286     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1287     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1288     src/HOL/Library/GCD.thy ~> src/HOL/
  1289     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1290     src/HOL/Library/Parity.thy ~> src/HOL/
  1291     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1292     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1293     src/HOL/Real/Lubs.thy ~> src/HOL/
  1294     src/HOL/Real/PReal.thy ~> src/HOL/
  1295     src/HOL/Real/Rational.thy ~> src/HOL/
  1296     src/HOL/Real/RComplete.thy ~> src/HOL/
  1297     src/HOL/Real/RealDef.thy ~> src/HOL/
  1298     src/HOL/Real/RealPow.thy ~> src/HOL/
  1299     src/HOL/Real/Real.thy ~> src/HOL/
  1300     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1301     src/HOL/Complex/Complex.thy ~> src/HOL/
  1302     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1303     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1304     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1305     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1306     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1307     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1308     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1309     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1310     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1311     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1312     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1313     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1314     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1315     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1316     src/HOL/Real/Float ~> src/HOL/Library/
  1317     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1318     src/HOL/Real/RealVector.thy ~> src/HOL/
  1319 
  1320     src/HOL/arith_data.ML ~> src/HOL/Tools
  1321     src/HOL/hologic.ML ~> src/HOL/Tools
  1322     src/HOL/simpdata.ML ~> src/HOL/Tools
  1323     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1324     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1325     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1326     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1327     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1328     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1329     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1330 
  1331     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1332     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1333     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1334     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1335     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1336     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1337 
  1338 * If methods "eval" and "evaluation" encounter a structured proof
  1339 state with !!/==>, only the conclusion is evaluated to True (if
  1340 possible), avoiding strange error messages.
  1341 
  1342 * Method "sizechange" automates termination proofs using (a
  1343 modification of) the size-change principle.  Requires SAT solver.  See
  1344 src/HOL/ex/Termination.thy for examples.
  1345 
  1346 * Simplifier: simproc for let expressions now unfolds if bound
  1347 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1348 
  1349 * Method "arith": Linear arithmetic now ignores all inequalities when
  1350 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1351 
  1352 * New attribute "arith" for facts that should always be used
  1353 automatically by arithmetic. It is intended to be used locally in
  1354 proofs, e.g.
  1355 
  1356   assumes [arith]: "x > 0"
  1357 
  1358 Global usage is discouraged because of possible performance impact.
  1359 
  1360 * New classes "top" and "bot" with corresponding operations "top" and
  1361 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1362 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1363 
  1364 * Changed definition lemma "less_fun_def" in order to provide an
  1365 instance for preorders on functions; use lemma "less_le" instead.
  1366 INCOMPATIBILITY.
  1367 
  1368 * Theory Orderings: class "wellorder" moved here, with explicit
  1369 induction rule "less_induct" as assumption.  For instantiation of
  1370 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1371 INCOMPATIBILITY.
  1372 
  1373 * Theory Orderings: added class "preorder" as superclass of "order".
  1374 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1375 etc. slightly changed.  Some theorems named order_class.* now named
  1376 preorder_class.*.
  1377 
  1378 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1379 "diag" to "Id_on".
  1380 
  1381 * Theory Finite_Set: added a new fold combinator of type
  1382 
  1383   ('a => 'b => 'b) => 'b => 'a set => 'b
  1384 
  1385 Occasionally this is more convenient than the old fold combinator
  1386 which is now defined in terms of the new one and renamed to
  1387 fold_image.
  1388 
  1389 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1390 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1391 extended with further lemmas!).  At the moment both still exist but
  1392 the former will disappear at some point.
  1393 
  1394 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1395 class recpower.  Type-specific simp rules for various recpower types
  1396 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1397 
  1398 rat_power_0    -> power_0
  1399 rat_power_Suc  -> power_Suc
  1400 realpow_0      -> power_0
  1401 realpow_Suc    -> power_Suc
  1402 complexpow_0   -> power_0
  1403 complexpow_Suc -> power_Suc
  1404 power_poly_0   -> power_0
  1405 power_poly_Suc -> power_Suc
  1406 
  1407 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1408 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1409 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1410 of lemmas from Divides has been generalized from nat to class
  1411 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1412 renames resulting from duplicate elimination:
  1413 
  1414     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1415     zero_dvd_iff ~>         dvd_0_left_iff
  1416     dvd_0 ~>                dvd_0_right
  1417     DIVISION_BY_ZERO_DIV ~> div_by_0
  1418     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1419     mult_div ~>             div_mult_self2_is_id
  1420     mult_mod ~>             mod_mult_self2_is_0
  1421 
  1422 * Theory IntDiv: removed many lemmas that are instances of class-based
  1423 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1424 rename old lemmas as follows:
  1425 
  1426 dvd_diff               -> nat_dvd_diff
  1427 dvd_zminus_iff         -> dvd_minus_iff
  1428 mod_add1_eq            -> mod_add_eq
  1429 mod_mult1_eq           -> mod_mult_right_eq
  1430 mod_mult1_eq'          -> mod_mult_left_eq
  1431 mod_mult_distrib_mod   -> mod_mult_eq
  1432 nat_mod_add_left_eq    -> mod_add_left_eq
  1433 nat_mod_add_right_eq   -> mod_add_right_eq
  1434 nat_mod_div_trivial    -> mod_div_trivial
  1435 nat_mod_mod_trivial    -> mod_mod_trivial
  1436 zdiv_zadd_self1        -> div_add_self1
  1437 zdiv_zadd_self2        -> div_add_self2
  1438 zdiv_zmult_self1       -> div_mult_self2_is_id
  1439 zdiv_zmult_self2       -> div_mult_self1_is_id
  1440 zdvd_triv_left         -> dvd_triv_left
  1441 zdvd_triv_right        -> dvd_triv_right
  1442 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1443 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1444 zmod_zadd_left_eq      -> mod_add_left_eq
  1445 zmod_zadd_right_eq     -> mod_add_right_eq
  1446 zmod_zadd_self1        -> mod_add_self1
  1447 zmod_zadd_self2        -> mod_add_self2
  1448 zmod_zadd1_eq          -> mod_add_eq
  1449 zmod_zdiff1_eq         -> mod_diff_eq
  1450 zmod_zdvd_zmod         -> mod_mod_cancel
  1451 zmod_zmod_cancel       -> mod_mod_cancel
  1452 zmod_zmult_self1       -> mod_mult_self2_is_0
  1453 zmod_zmult_self2       -> mod_mult_self1_is_0
  1454 zmod_1                 -> mod_by_1
  1455 zdiv_1                 -> div_by_1
  1456 zdvd_abs1              -> abs_dvd_iff
  1457 zdvd_abs2              -> dvd_abs_iff
  1458 zdvd_refl              -> dvd_refl
  1459 zdvd_trans             -> dvd_trans
  1460 zdvd_zadd              -> dvd_add
  1461 zdvd_zdiff             -> dvd_diff
  1462 zdvd_zminus_iff        -> dvd_minus_iff
  1463 zdvd_zminus2_iff       -> minus_dvd_iff
  1464 zdvd_zmultD            -> dvd_mult_right
  1465 zdvd_zmultD2           -> dvd_mult_left
  1466 zdvd_zmult_mono        -> mult_dvd_mono
  1467 zdvd_0_right           -> dvd_0_right
  1468 zdvd_0_left            -> dvd_0_left_iff
  1469 zdvd_1_left            -> one_dvd
  1470 zminus_dvd_iff         -> minus_dvd_iff
  1471 
  1472 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1473 
  1474 * The real numbers offer decimal input syntax: 12.34 is translated
  1475 into 1234/10^2. This translation is not reversed upon output.
  1476 
  1477 * Theory Library/Polynomial defines an abstract type 'a poly of
  1478 univariate polynomials with coefficients of type 'a.  In addition to
  1479 the standard ring operations, it also supports div and mod.  Code
  1480 generation is also supported, using list-style constructors.
  1481 
  1482 * Theory Library/Inner_Product defines a class of real_inner for real
  1483 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1484 => real.  Class real_inner is a subclass of real_normed_vector from
  1485 theory RealVector.
  1486 
  1487 * Theory Library/Product_Vector provides instances for the product
  1488 type 'a * 'b of several classes from RealVector and Inner_Product.
  1489 Definitions of addition, subtraction, scalar multiplication, norms,
  1490 and inner products are included.
  1491 
  1492 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1493 addition to the field operations, numerals and case syntax are also
  1494 supported.
  1495 
  1496 * Theory Library/Diagonalize provides constructive version of Cantor's
  1497 first diagonalization argument.
  1498 
  1499 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1500 zlcm (for int); carried together from various gcd/lcm developements in
  1501 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1502 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1503 may recover tupled syntax as follows:
  1504 
  1505     hide (open) const gcd
  1506     abbreviation gcd where
  1507       "gcd == (%(a, b). GCD.gcd a b)"
  1508     notation (output)
  1509       GCD.gcd ("gcd '(_, _')")
  1510 
  1511 The same works for lcm, zgcd, zlcm.
  1512 
  1513 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1514 instantiations for algebraic structures.  Removed some duplicate
  1515 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1516 
  1517 * ML antiquotation @{code} takes a constant as argument and generates
  1518 corresponding code in background and inserts name of the corresponding
  1519 resulting ML value/function/datatype constructor binding in place.
  1520 All occurrences of @{code} with a single ML block are generated
  1521 simultaneously.  Provides a generic and safe interface for
  1522 instrumentalizing code generation.  See
  1523 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1524 In future you ought to refrain from ad-hoc compiling generated SML
  1525 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1526 cannot refer to constants for which user-defined serializations are
  1527 set.  Refer to the corresponding ML counterpart directly in that
  1528 cases.
  1529 
  1530 * Command 'rep_datatype': instead of theorem names the command now
  1531 takes a list of terms denoting the constructors of the type to be
  1532 represented as datatype.  The characteristic theorems have to be
  1533 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1534 have disappeared in favour of existing ones:
  1535 
  1536     unit_induct                 ~> unit.induct
  1537     prod_induct                 ~> prod.induct
  1538     sum_induct                  ~> sum.induct
  1539     Suc_Suc_eq                  ~> nat.inject
  1540     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1541 
  1542 
  1543 *** HOL-Algebra ***
  1544 
  1545 * New locales for orders and lattices where the equivalence relation
  1546 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1547 locales use a record structure with field eq for the equivalence.
  1548 
  1549 * New theory of factorial domains.
  1550 
  1551 * Units_l_inv and Units_r_inv are now simp rules by default.
  1552 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1553 and/or r_inv will now also require deletion of these lemmas.
  1554 
  1555 * Renamed the following theorems, INCOMPATIBILITY:
  1556 
  1557 UpperD ~> Upper_memD
  1558 LowerD ~> Lower_memD
  1559 least_carrier ~> least_closed
  1560 greatest_carrier ~> greatest_closed
  1561 greatest_Lower_above ~> greatest_Lower_below
  1562 one_zero ~> carrier_one_zero
  1563 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1564 
  1565 
  1566 *** HOL-Nominal ***
  1567 
  1568 * Nominal datatypes can now contain type-variables.
  1569 
  1570 * Commands 'nominal_inductive' and 'equivariance' work with local
  1571 theory targets.
  1572 
  1573 * Nominal primrec can now works with local theory targets and its
  1574 specification syntax now conforms to the general format as seen in
  1575 'inductive' etc.
  1576 
  1577 * Method "perm_simp" honours the standard simplifier attributes
  1578 (no_asm), (no_asm_use) etc.
  1579 
  1580 * The new predicate #* is defined like freshness, except that on the
  1581 left hand side can be a set or list of atoms.
  1582 
  1583 * Experimental command 'nominal_inductive2' derives strong induction
  1584 principles for inductive definitions.  In contrast to
  1585 'nominal_inductive', which can only deal with a fixed number of
  1586 binders, it can deal with arbitrary expressions standing for sets of
  1587 atoms to be avoided.  The only inductive definition we have at the
  1588 moment that needs this generalisation is the typing rule for Lets in
  1589 the algorithm W:
  1590 
  1591  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1592  -----------------------------------------------------------------
  1593          Gamma |- Let x be t1 in t2 : T2
  1594 
  1595 In this rule one wants to avoid all the binders that are introduced by
  1596 "close Gamma T1".  We are looking for other examples where this
  1597 feature might be useful.  Please let us know.
  1598 
  1599 
  1600 *** HOLCF ***
  1601 
  1602 * Reimplemented the simplification procedure for proving continuity
  1603 subgoals.  The new simproc is extensible; users can declare additional
  1604 continuity introduction rules with the attribute [cont2cont].
  1605 
  1606 * The continuity simproc now uses a different introduction rule for
  1607 solving continuity subgoals on terms with lambda abstractions.  In
  1608 some rare cases the new simproc may fail to solve subgoals that the
  1609 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1610 Potential INCOMPATIBILITY.
  1611 
  1612 * Command 'fixrec': specification syntax now conforms to the general
  1613 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1614 examples.  INCOMPATIBILITY.
  1615 
  1616 
  1617 *** ZF ***
  1618 
  1619 * Proof of Zorn's Lemma for partial orders.
  1620 
  1621 
  1622 *** ML ***
  1623 
  1624 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1625 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1626 depends on multithreading, so timouts will not work before Poly/ML
  1627 5.2.1!
  1628 
  1629 * High-level support for concurrent ML programming, see
  1630 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1631 particularly convenient to organize independent functional
  1632 computations.  The concept of "synchronized variables" provides a
  1633 higher-order interface for components with shared state, avoiding the
  1634 delicate details of mutexes and condition variables.  (Requires
  1635 Poly/ML 5.2.1 or later.)
  1636 
  1637 * ML bindings produced via Isar commands are stored within the Isar
  1638 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1639 become thread-safe and work with undo as expected (concerning
  1640 top-level bindings, not side-effects on global references).
  1641 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1642 compiler at runtime; really global bindings need to be given outside a
  1643 theory.  (Requires Poly/ML 5.2 or later.)
  1644 
  1645 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1646 context.  Top-level ML bindings are stored within the proof context in
  1647 a purely sequential fashion, disregarding the nested proof structure.
  1648 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1649 proof.  (Requires Poly/ML 5.2 or later.)
  1650 
  1651 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1652 and Method.setup, as well as Isar commands 'attribute_setup' and
  1653 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1654 existing code accordingly, or use plain 'setup' together with old
  1655 Method.add_method.
  1656 
  1657 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1658 to 'a -> thm, while results are always tagged with an authentic oracle
  1659 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1660 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1661 accordingly.  Note that extra performance may be gained by producing
  1662 the cterm carefully, avoiding slow Thm.cterm_of.
  1663 
  1664 * Simplified interface for defining document antiquotations via
  1665 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1666 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1667 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1668 examples.
  1669 
  1670 * More systematic treatment of long names, abstract name bindings, and
  1671 name space operations.  Basic operations on qualified names have been
  1672 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1673 Long_Name.append.  Old type bstring has been mostly replaced by
  1674 abstract type binding (see structure Binding), which supports precise
  1675 qualification by packages and local theory targets, as well as proper
  1676 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1677 bstring values into Binding.name, or better pass through abstract
  1678 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1679 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1680 
  1681 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1682 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1683 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1684 
  1685 * Disposed old type and term read functions (Sign.read_def_typ,
  1686 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1687 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1688 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1689 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1690 resort for legacy applications.
  1691 
  1692 * Disposed old declarations, tactics, tactic combinators that refer to
  1693 the simpset or claset of an implicit theory (such as Addsimps,
  1694 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1695 embedded ML text, or local_simpset_of with a proper context passed as
  1696 explicit runtime argument.
  1697 
  1698 * Rules and tactics that read instantiations (read_instantiate,
  1699 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1700 context, which is required for parsing and type-checking.  Moreover,
  1701 the variables are specified as plain indexnames, not string encodings
  1702 thereof.  INCOMPATIBILITY.
  1703 
  1704 * Generic Toplevel.add_hook interface allows to analyze the result of
  1705 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1706 for theorem dependency output of transactions resulting in a new
  1707 theory state.
  1708 
  1709 * ML antiquotations: block-structured compilation context indicated by
  1710 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1711 
  1712   @{binding name}                         - basic name binding
  1713   @{let ?pat = term}                      - term abbreviation (HO matching)
  1714   @{note name = fact}                     - fact abbreviation
  1715   @{thm fact}                             - singleton fact (with attributes)
  1716   @{thms fact}                            - general fact (with attributes)
  1717   @{lemma prop by method}                 - singleton goal
  1718   @{lemma prop by meth1 meth2}            - singleton goal
  1719   @{lemma prop1 ... propN by method}      - general goal
  1720   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1721   @{lemma (open) ...}                     - open derivation
  1722 
  1723 
  1724 *** System ***
  1725 
  1726 * The Isabelle "emacs" tool provides a specific interface to invoke
  1727 Proof General / Emacs, with more explicit failure if that is not
  1728 installed (the old isabelle-interface script silently falls back on
  1729 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1730 installation location of the Proof General distribution.
  1731 
  1732 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1733 the Isabelle process into a JVM/Scala application.  See
  1734 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1735 process wrapper has been discontinued.)
  1736 
  1737 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1738 
  1739 * Various status messages (with exact source position information) are
  1740 emitted, if proper markup print mode is enabled.  This allows
  1741 user-interface components to provide detailed feedback on internal
  1742 prover operations.
  1743 
  1744 
  1745 
  1746 New in Isabelle2008 (June 2008)
  1747 -------------------------------
  1748 
  1749 *** General ***
  1750 
  1751 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1752 and updated, with formally checked references as hyperlinks.
  1753 
  1754 * Theory loader: use_thy (and similar operations) no longer set the
  1755 implicit ML context, which was occasionally hard to predict and in
  1756 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1757 provides a proper context already.
  1758 
  1759 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1760 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1761 'use' within a theory file will do the job.
  1762 
  1763 * Name space merge now observes canonical order, i.e. the second space
  1764 is inserted into the first one, while existing entries in the first
  1765 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1766 swap theory imports.
  1767 
  1768 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1769 INCOMPATIBILITY in identifier syntax etc.
  1770 
  1771 * Outer syntax: string tokens no longer admit escaped white space,
  1772 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1773 white space without escapes.
  1774 
  1775 * Outer syntax: string tokens may contain arbitrary character codes
  1776 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1777 "foo_bar".
  1778 
  1779 
  1780 *** Pure ***
  1781 
  1782 * Context-dependent token translations.  Default setup reverts locally
  1783 fixed variables, and adds hilite markup for undeclared frees.
  1784 
  1785 * Unused theorems can be found using the new command 'unused_thms'.
  1786 There are three ways of invoking it:
  1787 
  1788 (1) unused_thms
  1789      Only finds unused theorems in the current theory.
  1790 
  1791 (2) unused_thms thy_1 ... thy_n -
  1792      Finds unused theorems in the current theory and all of its ancestors,
  1793      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1794 
  1795 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1796      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1797      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1798      their ancestors.
  1799 
  1800 In order to increase the readability of the list produced by
  1801 unused_thms, theorems that have been created by a particular instance
  1802 of a theory command such as 'inductive' or 'function' are considered
  1803 to belong to the same "group", meaning that if at least one theorem in
  1804 this group is used, the other theorems in the same group are no longer
  1805 reported as unused.  Moreover, if all theorems in the group are
  1806 unused, only one theorem in the group is displayed.
  1807 
  1808 Note that proof objects have to be switched on in order for
  1809 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1810 usually the case when using Proof General with the default settings).
  1811 
  1812 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1813 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1814 duplicate fact bindings, or even accidental fact duplications.  Note
  1815 that tools may maintain dynamically scoped facts systematically, using
  1816 PureThy.add_thms_dynamic.
  1817 
  1818 * Command 'hide' now allows to hide from "fact" name space as well.
  1819 
  1820 * Eliminated destructive theorem database, simpset, claset, and
  1821 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1822 update of theories within ML code.
  1823 
  1824 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1825 INCOMPATIBILITY, object-logics depending on former Pure require
  1826 additional setup PureThy.old_appl_syntax_setup; object-logics
  1827 depending on former CPure need to refer to Pure.
  1828 
  1829 * Commands 'use' and 'ML' are now purely functional, operating on
  1830 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1831 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1832 INCOMPATIBILITY.
  1833 
  1834 * Command 'setup': discontinued implicit version with ML reference.
  1835 
  1836 * Instantiation target allows for simultaneous specification of class
  1837 instance operations together with an instantiation proof.
  1838 Type-checking phase allows to refer to class operations uniformly.
  1839 See src/HOL/Complex/Complex.thy for an Isar example and
  1840 src/HOL/Library/Eval.thy for an ML example.
  1841 
  1842 * Indexing of literal facts: be more serious about including only
  1843 facts from the visible specification/proof context, but not the
  1844 background context (locale etc.).  Affects `prop` notation and method
  1845 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1846 situations.
  1847 
  1848 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1849 "(open)" option, which used to expose internal bound variables to the
  1850 proof text.
  1851 
  1852 * Isar statements: removed obsolete case "rule_context".
  1853 INCOMPATIBILITY, better use explicit fixes/assumes.
  1854 
  1855 * Locale proofs: default proof step now includes 'unfold_locales';
  1856 hence 'proof' without argument may be used to unfold locale
  1857 predicates.
  1858 
  1859 
  1860 *** Document preparation ***
  1861 
  1862 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1863 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1864 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1865 spot); renamed link color from "darkblue" to "linkcolor" (default
  1866 value unchanged, can be redefined via \definecolor); no longer sets
  1867 "a4paper" option (unnecessary or even intrusive).
  1868 
  1869 * Antiquotation @{lemma A method} proves proposition A by the given
  1870 method (either a method name or a method name plus (optional) method
  1871 arguments in parentheses) and prints A just like @{prop A}.
  1872 
  1873 
  1874 *** HOL ***
  1875 
  1876 * New primrec package.  Specification syntax conforms in style to
  1877 definition/function/....  No separate induction rule is provided.  The
  1878 "primrec" command distinguishes old-style and new-style specifications
  1879 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1880 When adjusting theories, beware: constants stemming from new-style
  1881 primrec specifications have authentic syntax.
  1882 
  1883 * Metis prover is now an order of magnitude faster, and also works
  1884 with multithreading.
  1885 
  1886 * Metis: the maximum number of clauses that can be produced from a
  1887 theorem is now given by the attribute max_clauses.  Theorems that
  1888 exceed this number are ignored, with a warning printed.
  1889 
  1890 * Sledgehammer no longer produces structured proofs by default. To
  1891 enable, declare [[sledgehammer_full = true]].  Attributes
  1892 reconstruction_modulus, reconstruction_sorts renamed
  1893 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1894 
  1895 * Method "induct_scheme" derives user-specified induction rules
  1896 from well-founded induction and completeness of patterns. This factors
  1897 out some operations that are done internally by the function package
  1898 and makes them available separately.  See
  1899 src/HOL/ex/Induction_Scheme.thy for examples.
  1900 
  1901 * More flexible generation of measure functions for termination
  1902 proofs: Measure functions can be declared by proving a rule of the
  1903 form "is_measure f" and giving it the [measure_function] attribute.
  1904 The "is_measure" predicate is logically meaningless (always true), and
  1905 just guides the heuristic.  To find suitable measure functions, the
  1906 termination prover sets up the goal "is_measure ?f" of the appropriate
  1907 type and generates all solutions by prolog-style backwards proof using
  1908 the declared rules.
  1909 
  1910 This setup also deals with rules like 
  1911 
  1912   "is_measure f ==> is_measure (list_size f)"
  1913 
  1914 which accommodates nested datatypes that recurse through lists.
  1915 Similar rules are predeclared for products and option types.
  1916 
  1917 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1918 
  1919   INCOMPATIBILITIES:
  1920 
  1921   - Definitions of overloaded constants on sets have to be replaced by
  1922     definitions on => and bool.
  1923 
  1924   - Some definitions of overloaded operators on sets can now be proved
  1925     using the definitions of the operators on => and bool.  Therefore,
  1926     the following theorems have been renamed:
  1927 
  1928       subset_def   -> subset_eq
  1929       psubset_def  -> psubset_eq
  1930       set_diff_def -> set_diff_eq
  1931       Compl_def    -> Compl_eq
  1932       Sup_set_def  -> Sup_set_eq
  1933       Inf_set_def  -> Inf_set_eq
  1934       sup_set_def  -> sup_set_eq
  1935       inf_set_def  -> inf_set_eq
  1936 
  1937   - Due to the incompleteness of the HO unification algorithm, some
  1938     rules such as subst may require manual instantiation, if some of
  1939     the unknowns in the rule is a set.
  1940 
  1941   - Higher order unification and forward proofs:
  1942     The proof pattern
  1943 
  1944       have "P (S::'a set)" <...>
  1945       then have "EX S. P S" ..
  1946 
  1947     no longer works (due to the incompleteness of the HO unification
  1948     algorithm) and must be replaced by the pattern
  1949 
  1950       have "EX S. P S"
  1951       proof
  1952         show "P S" <...>
  1953       qed
  1954 
  1955   - Calculational reasoning with subst (or similar rules):
  1956     The proof pattern
  1957 
  1958       have "P (S::'a set)" <...>
  1959       also have "S = T" <...>
  1960       finally have "P T" .
  1961 
  1962     no longer works (for similar reasons as the previous example) and
  1963     must be replaced by something like
  1964 
  1965       have "P (S::'a set)" <...>
  1966       moreover have "S = T" <...>
  1967       ultimately have "P T" by simp
  1968 
  1969   - Tactics or packages written in ML code:
  1970     Code performing pattern matching on types via
  1971 
  1972       Type ("set", [T]) => ...
  1973 
  1974     must be rewritten. Moreover, functions like strip_type or
  1975     binder_types no longer return the right value when applied to a
  1976     type of the form
  1977 
  1978       T1 => ... => Tn => U => bool
  1979 
  1980     rather than
  1981 
  1982       T1 => ... => Tn => U set
  1983 
  1984 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1985 Wellfounded_Relations to theory Wellfounded.
  1986 
  1987 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1988 
  1989 * Class finite no longer treats UNIV as class parameter.  Use class
  1990 enum from theory Library/Enum instead to achieve a similar effect.
  1991 INCOMPATIBILITY.
  1992 
  1993 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1994 and "Cons".  INCOMPATIBILITY.
  1995 
  1996 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1997 Potential INCOMPATIBILITY.
  1998 
  1999 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2000 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2001 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2002 
  2003 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2004 the same name in theory Orderings:
  2005 
  2006   less_trans
  2007   less_linear
  2008   le_imp_less_or_eq
  2009   le_less_trans
  2010   less_le_trans
  2011   less_not_sym
  2012   less_asym
  2013 
  2014 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2015 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2016 and different variable names.
  2017 
  2018 * Library/Option_ord.thy: Canonical order on option type.
  2019 
  2020 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2021 finite maps.
  2022 
  2023 * Library/Countable.thy: Type class for countable types.
  2024 
  2025 * Theory Int: The representation of numerals has changed.  The infix
  2026 operator BIT and the bit datatype with constructors B0 and B1 have
  2027 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2028 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2029 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2030 accordingly.
  2031 
  2032 * Theory Nat: definition of <= and < on natural numbers no longer
  2033 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2034 le_def and less_def have disappeared.  Consider lemmas not_less
  2035 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2036 
  2037 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2038 (whose purpose mainly is for various fold_set functionals) have been
  2039 abandoned in favor of the existing algebraic classes
  2040 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2041 lower_semilattice (resp. upper_semilattice) and linorder.
  2042 INCOMPATIBILITY.
  2043 
  2044 * Theory Transitive_Closure: induct and cases rules now declare proper
  2045 case_names ("base" and "step").  INCOMPATIBILITY.
  2046 
  2047 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2048 lattices.  The form set-specific version is available as
  2049 Inductive.lfp_ordinal_induct_set.
  2050 
  2051 * Renamed theorems "power.simps" to "power_int.simps".
  2052 INCOMPATIBILITY.
  2053 
  2054 * Class semiring_div provides basic abstract properties of semirings
  2055 with division and modulo operations.  Subsumes former class dvd_mod.
  2056 
  2057 * Merged theories IntDef, Numeral and IntArith into unified theory
  2058 Int.  INCOMPATIBILITY.
  2059 
  2060 * Theory Library/Code_Index: type "index" now represents natural
  2061 numbers rather than integers.  INCOMPATIBILITY.
  2062 
  2063 * New class "uminus" with operation "uminus" (split of from class
  2064 "minus" which now only has operation "minus", binary).
  2065 INCOMPATIBILITY.
  2066 
  2067 * Constants "card", "internal_split", "option_map" now with authentic
  2068 syntax.  INCOMPATIBILITY.
  2069 
  2070 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2071 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2072 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2073 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2074 Sup_set_def, le_def, less_def, option_map_def now with object
  2075 equality.  INCOMPATIBILITY.
  2076 
  2077 * Records. Removed K_record, and replaced it by pure lambda term
  2078 %x. c. The simplifier setup is now more robust against eta expansion.
  2079 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2080 
  2081 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2082 
  2083 * Library/ListVector: new theory of arithmetic vector operations.
  2084 
  2085 * Library/Order_Relation: new theory of various orderings as sets of
  2086 pairs.  Defines preorders, partial orders, linear orders and
  2087 well-orders on sets and on types.
  2088 
  2089 
  2090 *** ZF ***
  2091 
  2092 * Renamed some theories to allow to loading both ZF and HOL in the
  2093 same session:
  2094 
  2095   Datatype  -> Datatype_ZF
  2096   Inductive -> Inductive_ZF
  2097   Int       -> Int_ZF
  2098   IntDiv    -> IntDiv_ZF
  2099   Nat       -> Nat_ZF
  2100   List      -> List_ZF
  2101   Main      -> Main_ZF
  2102 
  2103 INCOMPATIBILITY: ZF theories that import individual theories below
  2104 Main might need to be adapted.  Regular theory Main is still
  2105 available, as trivial extension of Main_ZF.
  2106 
  2107 
  2108 *** ML ***
  2109 
  2110 * ML within Isar: antiquotation @{const name} or @{const
  2111 name(typargs)} produces statically-checked Const term.
  2112 
  2113 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2114 (of the same name).  Removed obsolete print command.
  2115 
  2116 * Removed obsolete "use_legacy_bindings" function.
  2117 
  2118 * The ``print mode'' is now a thread-local value derived from a global
  2119 template (the former print_mode reference), thus access becomes
  2120 non-critical.  The global print_mode reference is for session
  2121 management only; user-code should use print_mode_value,
  2122 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2123 
  2124 * Functions system/system_out provide a robust way to invoke external
  2125 shell commands, with propagation of interrupts (requires Poly/ML
  2126 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2127 
  2128 
  2129 *** System ***
  2130 
  2131 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2132 in accordance with Proof General 3.7, which prefers GNU emacs.
  2133 
  2134 * isatool tty runs Isabelle process with plain tty interaction;
  2135 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2136 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2137 
  2138 * isatool browser now works with Cygwin as well, using general
  2139 "javapath" function defined in Isabelle process environment.
  2140 
  2141 * YXML notation provides a simple and efficient alternative to
  2142 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2143 isatool yxml as described in the Isabelle system manual.
  2144 
  2145 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2146 provides general wrapper for managing an Isabelle process in a robust
  2147 fashion, with ``cooked'' output from stdin/stderr.
  2148 
  2149 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2150 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2151 
  2152 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2153 way of changing the user's settings is via
  2154 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2155 script.
  2156 
  2157 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2158 cores of the underlying machine, which is a good starting point for
  2159 optimal performance tuning.  The corresponding usedir option -M allows
  2160 "max" as an alias for "0".  WARNING: does not work on certain versions
  2161 of Mac OS (with Poly/ML 5.1).
  2162 
  2163 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2164 adverse effect of Isabelle flooding interactive front-ends (notably
  2165 ProofGeneral / XEmacs).
  2166 
  2167 
  2168 
  2169 New in Isabelle2007 (November 2007)
  2170 -----------------------------------
  2171 
  2172 *** General ***
  2173 
  2174 * More uniform information about legacy features, notably a
  2175 warning/error of "Legacy feature: ...", depending on the state of the
  2176 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2177 legacy features will disappear eventually.
  2178 
  2179 * Theory syntax: the header format ``theory A = B + C:'' has been
  2180 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2181 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2182 
  2183 * Theory syntax: the old non-Isar theory file format has been
  2184 discontinued altogether.  Note that ML proof scripts may still be used
  2185 with Isar theories; migration is usually quite simple with the ML
  2186 function use_legacy_bindings.  INCOMPATIBILITY.
  2187 
  2188 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2189 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2190 quotes.
  2191 
  2192 * Theory loader: be more serious about observing the static theory
  2193 header specifications (including optional directories), but not the
  2194 accidental file locations of previously successful loads.  The strict
  2195 update policy of former update_thy is now already performed by
  2196 use_thy, so the former has been removed; use_thys updates several
  2197 theories simultaneously, just as 'imports' within a theory header
  2198 specification, but without merging the results.  Potential
  2199 INCOMPATIBILITY: may need to refine theory headers and commands
  2200 ROOT.ML which depend on load order.
  2201 
  2202 * Theory loader: optional support for content-based file
  2203 identification, instead of the traditional scheme of full physical
  2204 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2205 (cf. the system manual).  The new scheme allows to work with
  2206 non-finished theories in persistent session images, such that source
  2207 files may be moved later on without requiring reloads.
  2208 
  2209 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2210 file (with the same base name as the theory) are considered a legacy
  2211 feature, which will disappear eventually. Even now, the theory loader
  2212 no longer maintains dependencies on such files.
  2213 
  2214 * Syntax: the scope for resolving ambiguities via type-inference is
  2215 now limited to individual terms, instead of whole simultaneous
  2216 specifications as before. This greatly reduces the complexity of the
  2217 syntax module and improves flexibility by separating parsing and
  2218 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2219 'fixes' etc.) are required in rare situations.
  2220 
  2221 * Syntax: constants introduced by new-style packages ('definition',
  2222 'abbreviation' etc.) are passed through the syntax module in
  2223 ``authentic mode''. This means that associated mixfix annotations
  2224 really stick to such constants, independently of potential name space
  2225 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2226 trees are represented slightly differently, may need to adapt syntax
  2227 translations accordingly. Use CONST marker in 'translations' and
  2228 @{const_syntax} antiquotation in 'parse_translation' etc.
  2229 
  2230 * Legacy goal package: reduced interface to the bare minimum required
  2231 to keep existing proof scripts running.  Most other user-level
  2232 functions are now part of the OldGoals structure, which is *not* open
  2233 by default (consider isatool expandshort before open OldGoals).
  2234 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2235 these tend to cause confusion about the actual goal (!) context being
  2236 used here, which is not necessarily the same as the_context().
  2237 
  2238 * Command 'find_theorems': supports "*" wild-card in "name:"
  2239 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2240 support a specific search form (see ProofGeneral/CHANGES).
  2241 
  2242 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2243 by default, which means that "prems" (and also "fixed variables") are
  2244 suppressed from proof state output.  Note that the ProofGeneral
  2245 settings mechanism allows to change and save options persistently, but
  2246 older versions of Isabelle will fail to start up if a negative prems
  2247 limit is imposed.
  2248 
  2249 * Local theory targets may be specified by non-nested blocks of
  2250 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2251 contain definitions, theorems etc., including any derived mechanism
  2252 that has been implemented on top of these primitives.  This concept
  2253 generalizes the existing ``theorem (in ...)'' towards more versatility
  2254 and scalability.
  2255 
  2256 * Proof General interface: proper undo of final 'end' command;
  2257 discontinued Isabelle/classic mode (ML proof scripts).
  2258 
  2259 
  2260 *** Document preparation ***
  2261 
  2262 * Added antiquotation @{theory name} which prints the given name,
  2263 after checking that it refers to a valid ancestor theory in the
  2264 current context.
  2265 
  2266 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2267 check the given source text as ML type/structure, printing verbatim.
  2268 
  2269 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2270 "c args == rhs" given in the current context.  (Any number of
  2271 arguments may be given on the LHS.)
  2272 
  2273 
  2274 *** Pure ***
  2275 
  2276 * The 'class' package offers a combination of axclass and locale to
  2277 achieve Haskell-like type classes in Isabelle.  Definitions and
  2278 theorems within a class context produce both relative results (with
  2279 implicit parameters according to the locale context), and polymorphic
  2280 constants with qualified polymorphism (according to the class
  2281 context).  Within the body context of a 'class' target, a separate
  2282 syntax layer ("user space type system") takes care of converting
  2283 between global polymorphic consts and internal locale representation.
  2284 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2285 "isatool doc classes" provides a tutorial.
  2286 
  2287 * Generic code generator framework allows to generate executable
  2288 code for ML and Haskell (including Isabelle classes).  A short usage
  2289 sketch:
  2290 
  2291     internal compilation:
  2292         export_code <list of constants (term syntax)> in SML
  2293     writing SML code to a file:
  2294         export_code <list of constants (term syntax)> in SML <filename>
  2295     writing OCaml code to a file:
  2296         export_code <list of constants (term syntax)> in OCaml <filename>
  2297     writing Haskell code to a bunch of files:
  2298         export_code <list of constants (term syntax)> in Haskell <filename>
  2299 
  2300     evaluating closed propositions to True/False using code generation:
  2301         method ``eval''
  2302 
  2303 Reasonable default setup of framework in HOL.
  2304 
  2305 Theorem attributs for selecting and transforming function equations theorems:
  2306 
  2307     [code fun]:        select a theorem as function equation for a specific constant
  2308     [code fun del]:    deselect a theorem as function equation for a specific constant
  2309     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2310     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2311 
  2312 User-defined serializations (target in {SML, OCaml, Haskell}):
  2313 
  2314     code_const <and-list of constants (term syntax)>
  2315       {(target) <and-list of const target syntax>}+
  2316 
  2317     code_type <and-list of type constructors>
  2318       {(target) <and-list of type target syntax>}+
  2319 
  2320     code_instance <and-list of instances>
  2321       {(target)}+
  2322         where instance ::= <type constructor> :: <class>
  2323 
  2324     code_class <and_list of classes>
  2325       {(target) <and-list of class target syntax>}+
  2326         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2327 
  2328 code_instance and code_class only are effective to target Haskell.
  2329 
  2330 For example usage see src/HOL/ex/Codegenerator.thy and
  2331 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2332 generation from Isabelle/HOL theories is available via "isatool doc
  2333 codegen".
  2334 
  2335 * Code generator: consts in 'consts_code' Isar commands are now
  2336 referred to by usual term syntax (including optional type
  2337 annotations).
  2338 
  2339 * Command 'no_translations' removes translation rules from theory
  2340 syntax.
  2341 
  2342 * Overloaded definitions are now actually checked for acyclic
  2343 dependencies.  The overloading scheme is slightly more general than
  2344 that of Haskell98, although Isabelle does not demand an exact
  2345 correspondence to type class and instance declarations.
  2346 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2347 exotic versions of overloading -- at the discretion of the user!
  2348 
  2349 Polymorphic constants are represented via type arguments, i.e. the
  2350 instantiation that matches an instance against the most general
  2351 declaration given in the signature.  For example, with the declaration
  2352 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2353 as c(nat).  Overloading is essentially simultaneous structural
  2354 recursion over such type arguments.  Incomplete specification patterns
  2355 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2356 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2357 Command 'print_theory' outputs the normalized system of recursive
  2358 equations, see section "definitions".
  2359 
  2360 * Configuration options are maintained within the theory or proof
  2361 context (with name and type bool/int/string), providing a very simple
  2362 interface to a poor-man's version of general context data.  Tools may
  2363 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2364 these values using Config.get etc.  Users may change options via an
  2365 associated attribute of the same name.  This form of context
  2366 declaration works particularly well with commands 'declare' or
  2367 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2368 very easy to avoid global references, which would not observe Isar
  2369 toplevel undo/redo and fail to work with multithreading.
  2370 
  2371 Various global ML references of Pure and HOL have been turned into
  2372 configuration options:
  2373 
  2374   Unify.search_bound		unify_search_bound
  2375   Unify.trace_bound		unify_trace_bound
  2376   Unify.trace_simp		unify_trace_simp
  2377   Unify.trace_types		unify_trace_types
  2378   Simplifier.simp_depth_limit	simp_depth_limit
  2379   Blast.depth_limit		blast_depth_limit
  2380   DatatypeProp.dtK		datatype_distinctness_limit
  2381   fast_arith_neq_limit  	fast_arith_neq_limit
  2382   fast_arith_split_limit	fast_arith_split_limit
  2383 
  2384 * Named collections of theorems may be easily installed as context
  2385 data using the functor NamedThmsFun (see also
  2386 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2387 attributes; there is also a toplevel print command.  This facility is
  2388 just a common case of general context data, which is the preferred way
  2389 for anything more complex than just a list of facts in canonical
  2390 order.
  2391 
  2392 * Isar: command 'declaration' augments a local theory by generic
  2393 declaration functions written in ML.  This enables arbitrary content
  2394 being added to the context, depending on a morphism that tells the
  2395 difference of the original declaration context wrt. the application
  2396 context encountered later on.
  2397 
  2398 * Isar: proper interfaces for simplification procedures.  Command
  2399 'simproc_setup' declares named simprocs (with match patterns, and body
  2400 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2401 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2402 
  2403 * Isar: an extra pair of brackets around attribute declarations
  2404 abbreviates a theorem reference involving an internal dummy fact,
  2405 which will be ignored later --- only the effect of the attribute on
  2406 the background context will persist.  This form of in-place
  2407 declarations is particularly useful with commands like 'declare' and
  2408 'using', for example ``have A using [[simproc a]] by simp''.
  2409 
  2410 * Isar: method "assumption" (and implicit closing of subproofs) now
  2411 takes simple non-atomic goal assumptions into account: after applying
  2412 an assumption as a rule the resulting subgoals are solved by atomic
  2413 assumption steps.  This is particularly useful to finish 'obtain'
  2414 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2415 without referring to the original premise "!!x. P x ==> thesis" in the
  2416 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2417 more permissive.
  2418 
  2419 * Isar: implicit use of prems from the Isar proof context is
  2420 considered a legacy feature.  Common applications like ``have A .''
  2421 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2422 referencing facts explicitly here improves readability and
  2423 maintainability of proof texts.
  2424 
  2425 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2426 the obtained context from the course of reasoning!  For example:
  2427 
  2428   assume "EX x y. A x & B y"   -- "any previous fact"
  2429   then guess x and y by clarify
  2430 
  2431 This technique is potentially adventurous, depending on the facts and
  2432 proof tools being involved here.
  2433 
  2434 * Isar: known facts from the proof context may be specified as literal
  2435 propositions, using ASCII back-quote syntax.  This works wherever
  2436 named facts used to be allowed so far, in proof commands, proof
  2437 methods, attributes etc.  Literal facts are retrieved from the context
  2438 according to unification of type and term parameters.  For example,
  2439 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2440 theorems in the current context, then these are valid literal facts:
  2441 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2442 
  2443 There is also a proof method "fact" which does the same composition
  2444 for explicit goal states, e.g. the following proof texts coincide with
  2445 certain special cases of literal facts:
  2446 
  2447   have "A" by fact                 ==  note `A`
  2448   have "A ==> B" by fact           ==  note `A ==> B`
  2449   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2450   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2451 
  2452 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2453 outer syntax.  Thus symbolic identifiers may be used without
  2454 additional white space in declarations like this: ``assume *: A''.
  2455 
  2456 * Isar: 'print_facts' prints all local facts of the current context,
  2457 both named and unnamed ones.
  2458 
  2459 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2460 
  2461   def x == "t" and y == "u"
  2462 
  2463 * Isar: added command 'unfolding', which is structurally similar to
  2464 'using', but affects both the goal state and facts by unfolding given
  2465 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2466 'unfolded' attribute may be replaced by first-class proof text.
  2467 
  2468 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2469 and command 'unfolding' now all support object-level equalities
  2470 (potentially conditional).  The underlying notion of rewrite rule is
  2471 analogous to the 'rule_format' attribute, but *not* that of the
  2472 Simplifier (which is usually more generous).
  2473 
  2474 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2475 premises of a theorem by n. Useful in conjunction with drule.
  2476 
  2477 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2478 method expression within a sandbox consisting of the first N
  2479 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2480 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2481 simplifies all new goals that emerge from applying rule foo to the
  2482 originally first one.
  2483 
  2484 * Isar: schematic goals are no longer restricted to higher-order
  2485 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2486 expected.
  2487 
  2488 * Isar: the conclusion of a long theorem statement is now either
  2489 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2490 (essentially a disjunction of cases with local parameters and
  2491 assumptions).  The latter allows to express general elimination rules
  2492 adequately; in this notation common elimination rules look like this:
  2493 
  2494   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2495     assumes "EX x. P x"
  2496     obtains x where "P x"
  2497 
  2498   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2499     assumes "A & B"
  2500     obtains A and B
  2501 
  2502   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2503     assumes "A | B"
  2504     obtains
  2505       A
  2506     | B
  2507 
  2508 The subsequent classical rules even refer to the formal "thesis"
  2509 explicitly:
  2510 
  2511   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2512     obtains "~ thesis"
  2513 
  2514   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2515     obtains "thesis ==> something"
  2516 
  2517 The actual proof of an 'obtains' statement is analogous to that of the
  2518 Isar proof element 'obtain', only that there may be several cases.
  2519 Optional case names may be specified in parentheses; these will be
  2520 available both in the present proof and as annotations in the
  2521 resulting rule, for later use with the 'cases' method (cf. attribute
  2522 case_names).
  2523 
  2524 * Isar: the assumptions of a long theorem statement are available as
  2525 "assms" fact in the proof context.  This is more appropriate than the
  2526 (historical) "prems", which refers to all assumptions of the current
  2527 context, including those from the target locale, proof body etc.
  2528 
  2529 * Isar: 'print_statement' prints theorems from the current theory or
  2530 proof context in long statement form, according to the syntax of a
  2531 top-level lemma.
  2532 
  2533 * Isar: 'obtain' takes an optional case name for the local context
  2534 introduction rule (default "that").
  2535 
  2536 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2537 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2538 to occur.
  2539 
  2540 * Pure: syntax "CONST name" produces a fully internalized constant
  2541 according to the current context.  This is particularly useful for
  2542 syntax translations that should refer to internal constant
  2543 representations independently of name spaces.
  2544 
  2545 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2546 instead of "FOO ". This allows multiple binder declarations to coexist
  2547 in the same context.  INCOMPATIBILITY.
  2548 
  2549 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2550 primitive that also works in a locale context (both for constants and
  2551 fixed variables). Type declaration and internal syntactic representation
  2552 of given constants retrieved from the context. Likewise, the
  2553 'no_notation' command allows to remove given syntax annotations from the
  2554 current context.
  2555 
  2556 * Isar/locales: new derived specification elements 'axiomatization',
  2557 'definition', 'abbreviation', which support type-inference, admit
  2558 object-level specifications (equality, equivalence).  See also the
  2559 isar-ref manual.  Examples:
  2560 
  2561   axiomatization
  2562     eq  (infix "===" 50) where
  2563     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2564 
  2565   definition "f x y = x + y + 1"
  2566   definition g where "g x = f x x"
  2567 
  2568   abbreviation
  2569     neq  (infix "=!=" 50) where
  2570     "x =!= y == ~ (x === y)"
  2571 
  2572 These specifications may be also used in a locale context.  Then the
  2573 constants being introduced depend on certain fixed parameters, and the
  2574 constant name is qualified by the locale base name.  An internal
  2575 abbreviation takes care for convenient input and output, making the
  2576 parameters implicit and using the original short name.  See also
  2577 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2578 entities from a monomorphic theory.
  2579 
  2580 Presently, abbreviations are only available 'in' a target locale, but
  2581 not inherited by general import expressions.  Also note that
  2582 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2583 'translations' in common applications.  The "no_abbrevs" print mode
  2584 prevents folding of abbreviations in term output.
  2585 
  2586 Concrete syntax is attached to specified constants in internal form,
  2587 independently of name spaces.  The parse tree representation is
  2588 slightly different -- use 'notation' instead of raw 'syntax', and
  2589 'translations' with explicit "CONST" markup to accommodate this.
  2590 
  2591 * Pure/Isar: unified syntax for new-style specification mechanisms
  2592 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2593 full type inference and dummy patterns ("_").  For example:
  2594 
  2595   definition "K x _ = x"
  2596 
  2597   inductive conj for A B
  2598   where "A ==> B ==> conj A B"
  2599 
  2600 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2601 the current context.  Print mode "no_abbrevs" prevents inversion of
  2602 abbreviations on output.
  2603 
  2604 * Isar/locales: improved parameter handling: use of locales "var" and
  2605 "struct" no longer necessary; - parameter renamings are no longer
  2606 required to be injective.  For example, this allows to define
  2607 endomorphisms as locale endom = homom mult mult h.
  2608 
  2609 * Isar/locales: changed the way locales with predicates are defined.
  2610 Instead of accumulating the specification, the imported expression is
  2611 now an interpretation.  INCOMPATIBILITY: different normal form of
  2612 locale expressions.  In particular, in interpretations of locales with
  2613 predicates, goals repesenting already interpreted fragments are not
  2614 removed automatically.  Use methods `intro_locales' and
  2615 `unfold_locales'; see below.
  2616 
  2617 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2618 provide backward reasoning on locales predicates.  The methods are
  2619 aware of interpretations and discharge corresponding goals.
  2620 `intro_locales' is less aggressive then `unfold_locales' and does not
  2621 unfold predicates to assumptions.
  2622 
  2623 * Isar/locales: the order in which locale fragments are accumulated
  2624 has changed.  This enables to override declarations from fragments due
  2625 to interpretations -- for example, unwanted simp rules.
  2626 
  2627 * Isar/locales: interpretation in theories and proof contexts has been
  2628 extended.  One may now specify (and prove) equations, which are
  2629 unfolded in interpreted theorems.  This is useful for replacing
  2630 defined concepts (constants depending on locale parameters) by
  2631 concepts already existing in the target context.  Example:
  2632 
  2633   interpretation partial_order ["op <= :: [int, int] => bool"]
  2634     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2635 
  2636 Typically, the constant `partial_order.less' is created by a
  2637 definition specification element in the context of locale
  2638 partial_order.
  2639 
  2640 * Method "induct": improved internal context management to support
  2641 local fixes and defines on-the-fly. Thus explicit meta-level
  2642 connectives !!  and ==> are rarely required anymore in inductive goals
  2643 (using object-logic connectives for this purpose has been long
  2644 obsolete anyway). Common proof patterns are explained in
  2645 src/HOL/Induct/Common_Patterns.thy, see also
  2646 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2647 examples.
  2648 
  2649 * Method "induct": improved handling of simultaneous goals. Instead of
  2650 introducing object-level conjunction, the statement is now split into
  2651 several conclusions, while the corresponding symbolic cases are nested
  2652 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2653 see src/HOL/Induct/Common_Patterns.thy, for example.
  2654 
  2655 * Method "induct": mutual induction rules are now specified as a list
  2656 of rule sharing the same induction cases. HOL packages usually provide
  2657 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2658 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2659 mutual induction rules differently, i.e. like this:
  2660 
  2661   (induct rule: foo_bar.inducts)
  2662   (induct set: foo bar)
  2663   (induct pred: foo bar)
  2664   (induct type: foo bar)
  2665 
  2666 The ML function ProjectRule.projections turns old-style rules into the
  2667 new format.
  2668 
  2669 * Method "coinduct": dual of induction, see
  2670 src/HOL/Library/Coinductive_List.thy for various examples.
  2671 
  2672 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2673 considered a legacy feature.
  2674 
  2675 * Attribute "symmetric" produces result with standardized schematic
  2676 variables (index 0).  Potential INCOMPATIBILITY.
  2677 
  2678 * Simplifier: by default the simplifier trace only shows top level
  2679 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2680 default. Thus there is less danger of being flooded by the trace. The
  2681 trace indicates where parts have been suppressed.
  2682   
  2683 * Provers/classical: removed obsolete classical version of elim_format
  2684 attribute; classical elim/dest rules are now treated uniformly when
  2685 manipulating the claset.
  2686 
  2687 * Provers/classical: stricter checks to ensure that supplied intro,
  2688 dest and elim rules are well-formed; dest and elim rules must have at
  2689 least one premise.
  2690 
  2691 * Provers/classical: attributes dest/elim/intro take an optional
  2692 weight argument for the rule (just as the Pure versions).  Weights are
  2693 ignored by automated tools, but determine the search order of single
  2694 rule steps.
  2695 
  2696 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2697 where the body does not mention the bound variable.  Note that dummy
  2698 patterns implicitly depend on their context of bounds, which makes
  2699 "{_. _}" match any set comprehension as expected.  Potential
  2700 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2701 constant "_idtdummy" in the binding position.
  2702 
  2703 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2704 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2705 for example "A -> B" => "Pi A (%_. B)".
  2706 
  2707 * Pure: 'class_deps' command visualizes the subclass relation, using
  2708 the graph browser tool.
  2709 
  2710 * Pure: 'print_theory' now suppresses certain internal declarations by
  2711 default; use '!' option for full details.
  2712 
  2713 
  2714 *** HOL ***
  2715 
  2716 * Method "metis" proves goals by applying the Metis general-purpose
  2717 resolution prover (see also http://gilith.com/software/metis/).
  2718 Examples are in the directory MetisExamples.  WARNING: the
  2719 Isabelle/HOL-Metis integration does not yet work properly with
  2720 multi-threading.
  2721   
  2722 * Command 'sledgehammer' invokes external automatic theorem provers as
  2723 background processes.  It generates calls to the "metis" method if
  2724 successful. These can be pasted into the proof.  Users do not have to
  2725 wait for the automatic provers to return.  WARNING: does not really
  2726 work with multi-threading.
  2727 
  2728 * New "auto_quickcheck" feature tests outermost goal statements for
  2729 potential counter-examples.  Controlled by ML references
  2730 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2731 5000 milliseconds).  Fails silently if statements is outside of
  2732 executable fragment, or any other codgenerator problem occurs.
  2733 
  2734 * New constant "undefined" with axiom "undefined x = undefined".
  2735 
  2736 * Added class "HOL.eq", allowing for code generation with polymorphic
  2737 equality.
  2738 
  2739 * Some renaming of class constants due to canonical name prefixing in
  2740 the new 'class' package:
  2741 
  2742     HOL.abs ~> HOL.abs_class.abs
  2743     HOL.divide ~> HOL.divide_class.divide
  2744     0 ~> HOL.zero_class.zero
  2745     1 ~> HOL.one_class.one
  2746     op + ~> HOL.plus_class.plus
  2747     op - ~> HOL.minus_class.minus
  2748     uminus ~> HOL.minus_class.uminus
  2749     op * ~> HOL.times_class.times
  2750     op < ~> HOL.ord_class.less
  2751     op <= > HOL.ord_class.less_eq
  2752     Nat.power ~> Power.power_class.power
  2753     Nat.size ~> Nat.size_class.size
  2754     Numeral.number_of ~> Numeral.number_class.number_of
  2755     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2756     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2757     Orderings.min ~> Orderings.ord_class.min
  2758     Orderings.max ~> Orderings.ord_class.max
  2759     Divides.op div ~> Divides.div_class.div
  2760     Divides.op mod ~> Divides.div_class.mod
  2761     Divides.op dvd ~> Divides.div_class.dvd
  2762 
  2763 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2764 
  2765 a) User-defined constants using any of the names "plus", "minus",
  2766 "times", "less" or "less_eq". The standard syntax translations for
  2767 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2768 names.
  2769 
  2770 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2771 INCOMPATIBILITY: use more specific names.
  2772 
  2773 c) Permutative equations (e.g. "a + b = b + a")
  2774 Since the change of names also changes the order of terms, permutative
  2775 rewrite rules may get applied in a different order. Experience shows
  2776 that this is rarely the case (only two adaptions in the whole Isabelle
  2777 distribution).  INCOMPATIBILITY: rewrite proofs
  2778 
  2779 d) ML code directly refering to constant names
  2780 This in general only affects hand-written proof tactics, simprocs and
  2781 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2782 Consider using @{const_name} antiquotation.
  2783 
  2784 * New class "default" with associated constant "default".
  2785 
  2786 * Function "sgn" is now overloaded and available on int, real, complex
  2787 (and other numeric types), using class "sgn".  Two possible defs of
  2788 sgn are given as equational assumptions in the classes sgn_if and
  2789 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2790 INCOMPATIBILITY.
  2791 
  2792 * Locale "partial_order" now unified with class "order" (cf. theory
  2793 Orderings), added parameter "less".  INCOMPATIBILITY.
  2794 
  2795 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2796 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2797 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2798 
  2799 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2800 changed order of proof goals in instance proofs.
  2801 
  2802 * The transitivity reasoner for partial and linear orders is set up
  2803 for classes "order" and "linorder".  Instances of the reasoner are available
  2804 in all contexts importing or interpreting the corresponding locales.
  2805 Method "order" invokes the reasoner separately; the reasoner
  2806 is also integrated with the Simplifier as a solver.  Diagnostic
  2807 command 'print_orders' shows the available instances of the reasoner
  2808 in the current context.
  2809 
  2810 * Localized monotonicity predicate in theory "Orderings"; integrated
  2811 lemmas max_of_mono and min_of_mono with this predicate.
  2812 INCOMPATIBILITY.
  2813 
  2814 * Formulation of theorem "dense" changed slightly due to integration
  2815 with new class dense_linear_order.
  2816 
  2817 * Uniform lattice theory development in HOL.
  2818 
  2819     constants "meet" and "join" now named "inf" and "sup"
  2820     constant "Meet" now named "Inf"
  2821 
  2822     classes "meet_semilorder" and "join_semilorder" now named
  2823       "lower_semilattice" and "upper_semilattice"
  2824     class "lorder" now named "lattice"
  2825     class "comp_lat" now named "complete_lattice"
  2826 
  2827     Instantiation of lattice classes allows explicit definitions
  2828     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2829 
  2830   INCOMPATIBILITY.  Theorem renames:
  2831 
  2832     meet_left_le            ~> inf_le1
  2833     meet_right_le           ~> inf_le2
  2834     join_left_le            ~> sup_ge1
  2835     join_right_le           ~> sup_ge2
  2836     meet_join_le            ~> inf_sup_ord
  2837     le_meetI                ~> le_infI
  2838     join_leI                ~> le_supI
  2839     le_meet                 ~> le_inf_iff
  2840     le_join                 ~> ge_sup_conv
  2841     meet_idempotent         ~> inf_idem
  2842     join_idempotent         ~> sup_idem
  2843     meet_comm               ~> inf_commute
  2844     join_comm               ~> sup_commute
  2845     meet_leI1               ~> le_infI1
  2846     meet_leI2               ~> le_infI2
  2847     le_joinI1               ~> le_supI1
  2848     le_joinI2               ~> le_supI2
  2849     meet_assoc              ~> inf_assoc
  2850     join_assoc              ~> sup_assoc
  2851     meet_left_comm          ~> inf_left_commute
  2852     meet_left_idempotent    ~> inf_left_idem
  2853     join_left_comm          ~> sup_left_commute
  2854     join_left_idempotent    ~> sup_left_idem
  2855     meet_aci                ~> inf_aci
  2856     join_aci                ~> sup_aci
  2857     le_def_meet             ~> le_iff_inf
  2858     le_def_join             ~> le_iff_sup
  2859     join_absorp2            ~> sup_absorb2
  2860     join_absorp1            ~> sup_absorb1
  2861     meet_absorp1            ~> inf_absorb1
  2862     meet_absorp2            ~> inf_absorb2
  2863     meet_join_absorp        ~> inf_sup_absorb
  2864     join_meet_absorp        ~> sup_inf_absorb
  2865     distrib_join_le         ~> distrib_sup_le
  2866     distrib_meet_le         ~> distrib_inf_le
  2867 
  2868     add_meet_distrib_left   ~> add_inf_distrib_left
  2869     add_join_distrib_left   ~> add_sup_distrib_left
  2870     is_join_neg_meet        ~> is_join_neg_inf
  2871     is_meet_neg_join        ~> is_meet_neg_sup
  2872     add_meet_distrib_right  ~> add_inf_distrib_right
  2873     add_join_distrib_right  ~> add_sup_distrib_right
  2874     add_meet_join_distribs  ~> add_sup_inf_distribs
  2875     join_eq_neg_meet        ~> sup_eq_neg_inf
  2876     meet_eq_neg_join        ~> inf_eq_neg_sup
  2877     add_eq_meet_join        ~> add_eq_inf_sup
  2878     meet_0_imp_0            ~> inf_0_imp_0
  2879     join_0_imp_0            ~> sup_0_imp_0
  2880     meet_0_eq_0             ~> inf_0_eq_0
  2881     join_0_eq_0             ~> sup_0_eq_0
  2882     neg_meet_eq_join        ~> neg_inf_eq_sup
  2883     neg_join_eq_meet        ~> neg_sup_eq_inf
  2884     join_eq_if              ~> sup_eq_if
  2885 
  2886     mono_meet               ~> mono_inf
  2887     mono_join               ~> mono_sup
  2888     meet_bool_eq            ~> inf_bool_eq
  2889     join_bool_eq            ~> sup_bool_eq
  2890     meet_fun_eq             ~> inf_fun_eq
  2891     join_fun_eq             ~> sup_fun_eq
  2892     meet_set_eq             ~> inf_set_eq
  2893     join_set_eq             ~> sup_set_eq
  2894     meet1_iff               ~> inf1_iff
  2895     meet2_iff               ~> inf2_iff
  2896     meet1I                  ~> inf1I
  2897     meet2I                  ~> inf2I
  2898     meet1D1                 ~> inf1D1
  2899     meet2D1                 ~> inf2D1
  2900     meet1D2                 ~> inf1D2
  2901     meet2D2                 ~> inf2D2
  2902     meet1E                  ~> inf1E
  2903     meet2E                  ~> inf2E
  2904     join1_iff               ~> sup1_iff
  2905     join2_iff               ~> sup2_iff
  2906     join1I1                 ~> sup1I1
  2907     join2I1                 ~> sup2I1
  2908     join1I1                 ~> sup1I1
  2909     join2I2                 ~> sup1I2
  2910     join1CI                 ~> sup1CI
  2911     join2CI                 ~> sup2CI
  2912     join1E                  ~> sup1E
  2913     join2E                  ~> sup2E
  2914 
  2915     is_meet_Meet            ~> is_meet_Inf
  2916     Meet_bool_def           ~> Inf_bool_def
  2917     Meet_fun_def            ~> Inf_fun_def
  2918     Meet_greatest           ~> Inf_greatest
  2919     Meet_lower              ~> Inf_lower
  2920     Meet_set_def            ~> Inf_set_def
  2921 
  2922     Sup_def                 ~> Sup_Inf
  2923     Sup_bool_eq             ~> Sup_bool_def
  2924     Sup_fun_eq              ~> Sup_fun_def
  2925     Sup_set_eq              ~> Sup_set_def
  2926 
  2927     listsp_meetI            ~> listsp_infI
  2928     listsp_meet_eq          ~> listsp_inf_eq
  2929 
  2930     meet_min                ~> inf_min
  2931     join_max                ~> sup_max
  2932 
  2933 * Added syntactic class "size"; overloaded constant "size" now has
  2934 type "'a::size ==> bool"
  2935 
  2936 * Internal reorganisation of `size' of datatypes: size theorems
  2937 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2938 simplification rules by default!); theorems "prod.size" now named
  2939 "*.size".
  2940 
  2941 * Class "div" now inherits from class "times" rather than "type".
  2942 INCOMPATIBILITY.
  2943 
  2944 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2945 Linorder etc.  have disappeared; operations defined in terms of
  2946 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2947 
  2948 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2949 
  2950 * HOL-Word: New extensive library and type for generic, fixed size
  2951 machine words, with arithemtic, bit-wise, shifting and rotating
  2952 operations, reflection into int, nat, and bool lists, automation for
  2953 linear arithmetic (by automatic reflection into nat or int), including
  2954 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2955 arithmetic type classes, supporting automatic simplification of
  2956 numerals on all operations.
  2957 
  2958 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2959 
  2960 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2961 
  2962 * Code generator library theories:
  2963   - Code_Integer represents HOL integers by big integer literals in target
  2964     languages.
  2965   - Code_Char represents HOL characters by character literals in target
  2966     languages.
  2967   - Code_Char_chr like Code_Char, but also offers treatment of character
  2968     codes; includes Code_Integer.
  2969   - Executable_Set allows to generate code for finite sets using lists.
  2970   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2971     denominator).
  2972   - Executable_Real implements a subset of real numbers, namly those
  2973     representable by rational numbers.
  2974   - Efficient_Nat implements natural numbers by integers, which in general will
  2975     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2976     includes Code_Integer.
  2977   - Code_Index provides an additional datatype index which is mapped to
  2978     target-language built-in integers.
  2979   - Code_Message provides an additional datatype message_string which is isomorphic to
  2980     strings; messages are mapped to target-language strings.
  2981 
  2982 * New package for inductive predicates
  2983 
  2984   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2985 
  2986     inductive
  2987       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2988       for z_1 :: U_1 and ... and z_n :: U_m
  2989     where
  2990       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2991     | ...
  2992 
  2993   with full support for type-inference, rather than
  2994 
  2995     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2996 
  2997     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2998     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2999 
  3000     inductive "s z_1 ... z_m"
  3001     intros
  3002       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3003       ...
  3004 
  3005   For backward compatibility, there is a wrapper allowing inductive
  3006   sets to be defined with the new package via
  3007 
  3008     inductive_set
  3009       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3010       for z_1 :: U_1 and ... and z_n :: U_m
  3011     where
  3012       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3013     | ...
  3014 
  3015   or
  3016 
  3017     inductive_set
  3018       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3019       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3020       for z_1 :: U_1 and ... and z_n :: U_m
  3021     where
  3022       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3023     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3024     | ...
  3025 
  3026   if the additional syntax "p ..." is required.
  3027 
  3028   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3029   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3030 
  3031   INCOMPATIBILITIES:
  3032 
  3033   - Since declaration and definition of inductive sets or predicates
  3034     is no longer separated, abbreviations involving the newly
  3035     introduced sets or predicates must be specified together with the
  3036     introduction rules after the 'where' keyword (see above), rather
  3037     than before the actual inductive definition.
  3038 
  3039   - The variables in induction and elimination rules are now
  3040     quantified in the order of their occurrence in the introduction
  3041     rules, rather than in alphabetical order. Since this may break
  3042     some proofs, these proofs either have to be repaired, e.g. by
  3043     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3044     statements of the form
  3045 
  3046       case (rule_i a_i_1 ... a_i_{k_i})
  3047 
  3048     or the old order of quantification has to be restored by explicitly adding
  3049     meta-level quantifiers in the introduction rules, i.e.
  3050 
  3051       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3052 
  3053   - The format of the elimination rules is now
  3054 
  3055       p z_1 ... z_m x_1 ... x_n ==>
  3056         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3057         ==> ... ==> P
  3058 
  3059     for predicates and
  3060 
  3061       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3062         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3063         ==> ... ==> P
  3064 
  3065     for sets rather than
  3066 
  3067       x : s z_1 ... z_m ==>
  3068         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3069         ==> ... ==> P
  3070 
  3071     This may require terms in goals to be expanded to n-tuples
  3072     (e.g. using case_tac or simplification with the split_paired_all
  3073     rule) before the above elimination rule is applicable.
  3074 
  3075   - The elimination or case analysis rules for (mutually) inductive
  3076     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3077     list of rules "p_1_..._p_k.elims" is no longer available.
  3078 
  3079 * New package "function"/"fun" for general recursive functions,
  3080 supporting mutual and nested recursion, definitions in local contexts,
  3081 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3082 for small examples, and the separate tutorial on the function
  3083 package. The old recdef "package" is still available as before, but
  3084 users are encouraged to use the new package.
  3085 
  3086 * Method "lexicographic_order" automatically synthesizes termination
  3087 relations as lexicographic combinations of size measures. 
  3088 
  3089 * Case-expressions allow arbitrary constructor-patterns (including
  3090 "_") and take their order into account, like in functional
  3091 programming.  Internally, this is translated into nested
  3092 case-expressions; missing cases are added and mapped to the predefined
  3093 constant "undefined". In complicated cases printing may no longer show
  3094 the original input but the internal form. Lambda-abstractions allow
  3095 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3096 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3097 variable.
  3098 
  3099 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3100 is an abbreviation for "of_nat :: nat => int". The simplification
  3101 rules for "of_nat" have been changed to work like "int" did
  3102 previously.  Potential INCOMPATIBILITY:
  3103   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3104   - of_nat_diff and of_nat_mult are no longer default simp rules
  3105 
  3106 * Method "algebra" solves polynomial equations over (semi)rings using
  3107 Groebner bases. The (semi)ring structure is defined by locales and the
  3108 tool setup depends on that generic context. Installing the method for
  3109 a specific type involves instantiating the locale and possibly adding
  3110 declarations for computation on the coefficients.  The method is
  3111 already instantiated for natural numbers and for the axiomatic class
  3112 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3113 CALCULEMUS 2007 for the general principles underlying this
  3114 architecture of context-aware proof-tools.
  3115 
  3116 * Method "ferrack" implements quantifier elimination over
  3117 special-purpose dense linear orders using locales (analogous to
  3118 "algebra"). The method is already installed for class
  3119 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3120 rat, etc.
  3121 
  3122 * Former constant "List.op @" now named "List.append".  Use ML
  3123 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3124 circumvent possible incompatibilities when working on ML level.
  3125 
  3126 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3127 
  3128 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3129 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3130 
  3131 * New syntax for Haskell-like list comprehension (input only), eg.
  3132 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3133 
  3134 * The special syntax for function "filter" has changed from [x :
  3135 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3136 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3137 
  3138 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3139 defined on nat only, as an abbreviation for [a..<Suc b]
  3140 INCOMPATIBILITY.
  3141 
  3142 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3143 
  3144 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3145 
  3146 * New lemma collection field_simps (an extension of ring_simps) for
  3147 manipulating (in)equations involving division. Multiplies with all
  3148 denominators that can be proved to be non-zero (in equations) or
  3149 positive/negative (in inequations).
  3150 
  3151 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3152 have been improved and renamed to ring_simps, group_simps and
  3153 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3154 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3155 
  3156 * Theory Library/Commutative_Ring: switched from recdef to function
  3157 package; constants add, mul, pow now curried.  Infix syntax for
  3158 algebraic operations.
  3159 
  3160 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3161 INCOMPATIBILITY.
  3162 
  3163 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3164 INCOMPATIBILITY.
  3165 
  3166 * HOL/records: generalised field-update to take a function on the
  3167 field rather than the new value: r(|A := x|) is translated to A_update
  3168 (K x) r The K-combinator that is internally used is called K_record.
  3169 INCOMPATIBILITY: Usage of the plain update functions has to be
  3170 adapted.
  3171  
  3172 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3173 * x = 0, which are required for a semiring.  Richer structures do not
  3174 inherit from semiring_0 anymore, because this property is a theorem
  3175 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3176 there is more to prove, but this is mostly trivial.
  3177 
  3178 * Class "recpower" is generalized to arbitrary monoids, not just
  3179 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3180 commutativity or semiring properties additionally.
  3181 
  3182 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3183 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3184 better use 'abbreviation'.
  3185 
  3186 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3187 
  3188 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3189 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3190 significant changes for setting up numeral syntax for types:
  3191   - New constants Numeral.pred and Numeral.succ instead
  3192       of former Numeral.bin_pred and Numeral.bin_succ.
  3193   - Use integer operations instead of bin_add, bin_mult and so on.
  3194   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3195   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3196 
  3197 See src/HOL/Integ/IntArith.thy for an example setup.
  3198 
  3199 * Command 'normal_form' computes the normal form of a term that may
  3200 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3201 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3202 heavy-duty computations because the functions are compiled to ML
  3203 first.  Correspondingly, a method "normalization" is provided.  See
  3204 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3205 
  3206 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3207 25 like -->); output depends on the "iff" print_mode, the default is
  3208 "A = B" (with priority 50).
  3209 
  3210 * Relations less (<) and less_eq (<=) are also available on type bool.
  3211 Modified syntax to disallow nesting without explicit parentheses,
  3212 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3213 INCOMPATIBILITY.
  3214 
  3215 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3216 
  3217 * Relation composition operator "op O" now has precedence 75 and binds
  3218 stronger than union and intersection. INCOMPATIBILITY.
  3219 
  3220 * The old set interval syntax "{m..n(}" (and relatives) has been
  3221 removed.  Use "{m..<n}" (and relatives) instead.
  3222 
  3223 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3224 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3225 ``declare [[simproc del: neq]]''.
  3226 
  3227 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3228 True/False.
  3229 
  3230 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3231 
  3232 * Theorem setsum_mult renamed to setsum_right_distrib.
  3233 
  3234 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3235 ``rule'' method.
  3236 
  3237 * Reimplemented methods "sat" and "satx", with several improvements:
  3238 goals no longer need to be stated as "<prems> ==> False", equivalences
  3239 (i.e. "=" on type bool) are handled, variable names of the form
  3240 "lit_<n>" are no longer reserved, significant speedup.
  3241 
  3242 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3243 zChaff is still supported as well.
  3244 
  3245 * 'inductive' and 'datatype': provide projections of mutual rules,
  3246 bundled as foo_bar.inducts;
  3247 
  3248 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3249 Library.
  3250 
  3251 * Library: moved theory Accessible_Part to main HOL.
  3252 
  3253 * Library: added theory Coinductive_List of potentially infinite lists
  3254 as greatest fixed-point.
  3255 
  3256 * Library: added theory AssocList which implements (finite) maps as
  3257 association lists.
  3258 
  3259 * Method "evaluation" solves goals (i.e. a boolean expression)
  3260 efficiently by compiling it to ML.  The goal is "proved" (via an
  3261 oracle) if it evaluates to True.
  3262 
  3263 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3264 also when invoked by the simplifier.  This results in the Simplifier
  3265 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3266 Configuration option fast_arith_split_limit=0 recovers the old
  3267 behavior.
  3268 
  3269 * Support for hex (0x20) and binary (0b1001) numerals.
  3270 
  3271 * New method: reify eqs (t), where eqs are equations for an
  3272 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3273 parameter, computes a term s::'b and a list xs::'a list and proves the
  3274 theorem I xs s = t. This is also known as reification or quoting. The
  3275 resulting theorem is applied to the subgoal to substitute t with I xs
  3276 s.  If t is omitted, the subgoal itself is reified.
  3277 
  3278 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3279 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3280 where f is supposed to be a computable function (in the sense of code
  3281 generattion). The method uses reify to compute s and xs as above then
  3282 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3283 r and finally gets the theorem t = r, which is again applied to the
  3284 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3285 
  3286 * Reflection: Automatic reification now handels binding, an example is
  3287 available in src/HOL/ex/ReflectionEx.thy
  3288 
  3289 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3290 command 'statespace' that is similar to 'record', but introduces an
  3291 abstract specification based on the locale infrastructure instead of
  3292 HOL types.  This leads to extra flexibility in composing state spaces,
  3293 in particular multiple inheritance and renaming of components.
  3294 
  3295 
  3296 *** HOL-Complex ***
  3297 
  3298 * Hyperreal: Functions root and sqrt are now defined on negative real
  3299 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3300 Nonnegativity side conditions have been removed from many lemmas, so
  3301 that more subgoals may now be solved by simplification; potential
  3302 INCOMPATIBILITY.
  3303 
  3304 * Real: new type classes formalize real normed vector spaces and
  3305 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3306 and norm :: 'a => real.
  3307 
  3308 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3309 reals into other types. The overloaded constant Reals :: 'a set is now
  3310 defined as range of_real; potential INCOMPATIBILITY.
  3311 
  3312 * Real: proper support for ML code generation, including 'quickcheck'.
  3313 Reals are implemented as arbitrary precision rationals.
  3314 
  3315 * Hyperreal: Several constants that previously worked only for the
  3316 reals have been generalized, so they now work over arbitrary vector
  3317 spaces. Type annotations may need to be added in some cases; potential
  3318 INCOMPATIBILITY.
  3319 
  3320   Infinitesimal  :: ('a::real_normed_vector) star set
  3321   HFinite        :: ('a::real_normed_vector) star set
  3322   HInfinite      :: ('a::real_normed_vector) star set
  3323   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3324   monad          :: ('a::real_normed_vector) star => 'a star set
  3325   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3326   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3327   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3328   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3329   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3330   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3331   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3332   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3333   sgn            :: 'a::real_normed_vector => 'a
  3334   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3335 
  3336 * Complex: Some complex-specific constants are now abbreviations for
  3337 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3338 hnorm.  Other constants have been entirely removed in favor of the
  3339 polymorphic versions (INCOMPATIBILITY):
  3340 
  3341   approx        <-- capprox
  3342   HFinite       <-- CFinite
  3343   HInfinite     <-- CInfinite
  3344   Infinitesimal <-- CInfinitesimal
  3345   monad         <-- cmonad
  3346   galaxy        <-- cgalaxy
  3347   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3348   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3349   (ns)deriv     <-- (ns)cderiv
  3350 
  3351 
  3352 *** HOL-Algebra ***
  3353 
  3354 * Formalisation of ideals and the quotient construction over rings.
  3355 
  3356 * Order and lattice theory no longer based on records.
  3357 INCOMPATIBILITY.
  3358 
  3359 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3360 greatest_closed.  INCOMPATIBILITY.
  3361 
  3362 * Method algebra is now set up via an attribute.  For examples see
  3363 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3364 of algebraic structures.
  3365 
  3366 * Renamed theory CRing to Ring.
  3367 
  3368 
  3369 *** HOL-Nominal ***
  3370 
  3371 * Substantial, yet incomplete support for nominal datatypes (binding
  3372 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3373 src/HOL/Nominal/Examples.  Prospective users should consult
  3374 http://isabelle.in.tum.de/nominal/
  3375 
  3376 
  3377 *** ML ***
  3378 
  3379 * ML basics: just one true type int, which coincides with IntInf.int
  3380 (even on SML/NJ).
  3381 
  3382 * ML within Isar: antiquotations allow to embed statically-checked
  3383 formal entities in the source, referring to the context available at
  3384 compile-time.  For example:
  3385 
  3386 ML {* @{sort "{zero,one}"} *}
  3387 ML {* @{typ "'a => 'b"} *}
  3388 ML {* @{term "%x. x"} *}
  3389 ML {* @{prop "x == y"} *}
  3390 ML {* @{ctyp "'a => 'b"} *}
  3391 ML {* @{cterm "%x. x"} *}
  3392 ML {* @{cprop "x == y"} *}
  3393 ML {* @{thm asm_rl} *}
  3394 ML {* @{thms asm_rl} *}
  3395 ML {* @{type_name c} *}
  3396 ML {* @{type_syntax c} *}
  3397 ML {* @{const_name c} *}
  3398 ML {* @{const_syntax c} *}
  3399 ML {* @{context} *}
  3400 ML {* @{theory} *}
  3401 ML {* @{theory Pure} *}
  3402 ML {* @{theory_ref} *}
  3403 ML {* @{theory_ref Pure} *}
  3404 ML {* @{simpset} *}
  3405 ML {* @{claset} *}
  3406 ML {* @{clasimpset} *}
  3407 
  3408 The same works for sources being ``used'' within an Isar context.
  3409 
  3410 * ML in Isar: improved error reporting; extra verbosity with
  3411 ML_Context.trace enabled.
  3412 
  3413 * Pure/General/table.ML: the join operations now works via exceptions
  3414 DUP/SAME instead of type option. This is simpler in simple cases, and
  3415 admits slightly more efficient complex applications.
  3416 
  3417 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3418 use Context.generic instead of just theory.
  3419 
  3420 * Pure: datatype Context.generic joins theory/Proof.context and
  3421 provides some facilities for code that works in either kind of
  3422 context, notably GenericDataFun for uniform theory and proof data.
  3423 
  3424 * Pure: simplified internal attribute type, which is now always
  3425 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3426 local (Proof.context) attributes have been discontinued, while
  3427 minimizing code duplication. Thm.rule_attribute and
  3428 Thm.declaration_attribute build canonical attributes; see also structure
  3429 Context for further operations on Context.generic, notably
  3430 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3431 declarations and definitions.
  3432 
  3433 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3434 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3435 init only required for impure data. INCOMPATIBILITY: empty really need
  3436 to be empty (no dependencies on theory content!)
  3437 
  3438 * Pure/kernel: consts certification ignores sort constraints given in
  3439 signature declarations. (This information is not relevant to the
  3440 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3441 potential INCOMPATIBILITY.
  3442 
  3443 * Pure: axiomatic type classes are now purely definitional, with
  3444 explicit proofs of class axioms and super class relations performed
  3445 internally. See Pure/axclass.ML for the main internal interfaces --
  3446 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3447 AxClass.axiomatize_class/classrel/arity supersede
  3448 Sign.add_classes/classrel/arities.
  3449 
  3450 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3451 global/local versions on theory vs. Proof.context have been
  3452 discontinued; Attrib.syntax and Method.syntax have been adapted
  3453 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3454 attributes, methods, etc.
  3455 
  3456 * Pure: several functions of signature "... -> theory -> theory * ..."
  3457 have been reoriented to "... -> theory -> ... * theory" in order to
  3458 allow natural usage in combination with the ||>, ||>>, |-> and
  3459 fold_map combinators.
  3460 
  3461 * Pure: official theorem names (closed derivations) and additional
  3462 comments (tags) are now strictly separate.  Name hints -- which are
  3463 maintained as tags -- may be attached any time without affecting the
  3464 derivation.
  3465 
  3466 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3467 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3468 achieve the old behaviour.
  3469 
  3470 * Pure: the "Goal" constant is now called "prop", supporting a
  3471 slightly more general idea of ``protecting'' meta-level rule
  3472 statements.
  3473 
  3474 * Pure: Logic.(un)varify only works in a global context, which is now
  3475 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3476 Logic.legacy_(un)varify as temporary workaround.
  3477 
  3478 * Pure: structure Name provides scalable operations for generating
  3479 internal variable names, notably Name.variants etc.  This replaces
  3480 some popular functions from term.ML:
  3481 
  3482   Term.variant		->  Name.variant
  3483   Term.variantlist	->  Name.variant_list
  3484   Term.invent_names	->  Name.invent_list
  3485 
  3486 Note that low-level renaming rarely occurs in new code -- operations
  3487 from structure Variable are used instead (see below).
  3488 
  3489 * Pure: structure Variable provides fundamental operations for proper
  3490 treatment of fixed/schematic variables in a context.  For example,
  3491 Variable.import introduces fixes for schematics of given facts and
  3492 Variable.export reverses the effect (up to renaming) -- this replaces
  3493 various freeze_thaw operations.
  3494 
  3495 * Pure: structure Goal provides simple interfaces for
  3496 init/conclude/finish and tactical prove operations (replacing former
  3497 Tactic.prove).  Goal.prove is the canonical way to prove results
  3498 within a given context; Goal.prove_global is a degraded version for
  3499 theory level goals, including a global Drule.standard.  Note that
  3500 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3501 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3502 in a locale context).
  3503 
  3504 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3505 and type checking (Syntax.check_term etc.), with common combinations
  3506 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3507 which are considered legacy and await removal.
  3508 
  3509 * Pure/Syntax: generic interfaces for type unchecking
  3510 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3511 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3512 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3513 available for convenience, but refer to the very same operations using
  3514 a mere theory instead of a full context.
  3515 
  3516 * Isar: simplified treatment of user-level errors, using exception
  3517 ERROR of string uniformly.  Function error now merely raises ERROR,
  3518 without any side effect on output channels.  The Isar toplevel takes
  3519 care of proper display of ERROR exceptions.  ML code may use plain
  3520 handle/can/try; cat_error may be used to concatenate errors like this:
  3521 
  3522   ... handle ERROR msg => cat_error msg "..."
  3523 
  3524 Toplevel ML code (run directly or through the Isar toplevel) may be
  3525 embedded into the Isar toplevel with exception display/debug like
  3526 this:
  3527 
  3528   Isar.toplevel (fn () => ...)
  3529 
  3530 INCOMPATIBILITY, removed special transform_error facilities, removed
  3531 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3532 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3533 -- use plain ERROR instead.
  3534 
  3535 * Isar: theory setup now has type (theory -> theory), instead of a
  3536 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3537 
  3538 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3539 ProofContext.debug/verbose flags.
  3540 
  3541 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3542 theory before entering a proof state.  Transactions now always see a
  3543 quasi-functional intermediate checkpoint, both in interactive and
  3544 batch mode.
  3545 
  3546 * Isar: simplified interfaces for outer syntax.  Renamed
  3547 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3548 OuterSyntax.add_parsers -- this functionality is now included in
  3549 OuterSyntax.command etc.  INCOMPATIBILITY.
  3550 
  3551 * Simplifier: the simpset of a running simplification process now
  3552 contains a proof context (cf. Simplifier.the_context), which is the
  3553 very context that the initial simpset has been retrieved from (by
  3554 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3555 (solver, looper etc.) may depend on arbitrary proof data.
  3556 
  3557 * Simplifier.inherit_context inherits the proof context (plus the
  3558 local bounds) of the current simplification process; any simproc
  3559 etc. that calls the Simplifier recursively should do this!  Removed
  3560 former Simplifier.inherit_bounds, which is already included here --
  3561 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3562 specify an explicit context using Simplifier.context/theory_context.
  3563 
  3564 * Simplifier/Classical Reasoner: more abstract interfaces
  3565 change_simpset/claset for modifying the simpset/claset reference of a
  3566 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3567 INCOMPATIBILITY.
  3568 
  3569 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3570 "Trueprop" etc.
  3571 
  3572 
  3573 *** System ***
  3574 
  3575 * settings: the default heap location within ISABELLE_HOME_USER now
  3576 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3577 Isabelle installations.
  3578 
  3579 * isabelle-process: option -S (secure mode) disables some critical
  3580 operations, notably runtime compilation and evaluation of ML source
  3581 code.
  3582 
  3583 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3584 
  3585 * Support for parallel execution, using native multicore support of
  3586 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3587 independent theories, according to the given theory header
  3588 specifications. The maximum number of worker threads is specified via
  3589 usedir option -M or the "max-threads" setting in Proof General. A
  3590 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3591 to 6 on a 8-core machine.  User-code needs to observe certain
  3592 guidelines for thread-safe programming, see appendix A in the Isar
  3593 Implementation manual.
  3594 
  3595 
  3596 
  3597 New in Isabelle2005 (October 2005)
  3598 ----------------------------------
  3599 
  3600 *** General ***
  3601 
  3602 * Theory headers: the new header syntax for Isar theories is
  3603 
  3604   theory <name>
  3605   imports <theory1> ... <theoryN>
  3606   uses <file1> ... <fileM>
  3607   begin
  3608 
  3609 where the 'uses' part is optional.  The previous syntax
  3610 
  3611   theory <name> = <theory1> + ... + <theoryN>:
  3612 
  3613 will disappear in the next release.  Use isatool fixheaders to convert
  3614 existing theory files.  Note that there is no change in ancient
  3615 non-Isar theories now, but these will disappear soon.
  3616 
  3617 * Theory loader: parent theories can now also be referred to via
  3618 relative and absolute paths.
  3619 
  3620 * Command 'find_theorems' searches for a list of criteria instead of a
  3621 list of constants. Known criteria are: intro, elim, dest, name:string,
  3622 simp:term, and any term. Criteria can be preceded by '-' to select
  3623 theorems that do not match. Intro, elim, dest select theorems that
  3624 match the current goal, name:s selects theorems whose fully qualified
  3625 name contain s, and simp:term selects all simplification rules whose
  3626 lhs match term.  Any other term is interpreted as pattern and selects
  3627 all theorems matching the pattern. Available in ProofGeneral under
  3628 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3629 
  3630   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3631 
  3632 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3633 matching the current goal as introduction rule and not having "HOL."
  3634 in their name (i.e. not being defined in theory HOL).
  3635 
  3636 * Command 'thms_containing' has been discontinued in favour of
  3637 'find_theorems'; INCOMPATIBILITY.
  3638 
  3639 * Communication with Proof General is now 8bit clean, which means that
  3640 Unicode text in UTF-8 encoding may be used within theory texts (both
  3641 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3642 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3643 
  3644   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3645   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3646 
  3647 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3648 Classical Reasoner.  Typical big applications run around 2 times
  3649 faster.
  3650 
  3651 
  3652 *** Document preparation ***
  3653 
  3654 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3655 of raw sources.  Only those symbols that do not require additional
  3656 LaTeX packages (depending on comments in isabellesym.sty) are
  3657 displayed properly, everything else is left verbatim.  isatool display
  3658 and isatool print are used as front ends (these are subject to the
  3659 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3660 
  3661 * Command tags control specific markup of certain regions of text,
  3662 notably folding and hiding.  Predefined tags include "theory" (for
  3663 theory begin and end), "proof" for proof commands, and "ML" for
  3664 commands involving ML code; the additional tags "visible" and
  3665 "invisible" are unused by default.  Users may give explicit tag
  3666 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3667 interpretation of tags is determined by the LaTeX job during document
  3668 preparation: see option -V of isatool usedir, or options -n and -t of
  3669 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3670 \isadroptag.
  3671 
  3672 Several document versions may be produced at the same time via isatool
  3673 usedir (the generated index.html will link all of them).  Typical
  3674 specifications include ''-V document=theory,proof,ML'' to present
  3675 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3676 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3677 these parts without any formal replacement text.  The Isabelle site
  3678 default settings produce ''document'' and ''outline'' versions as
  3679 specified above.
  3680 
  3681 * Several new antiquotations:
  3682 
  3683   @{term_type term} prints a term with its type annotated;
  3684 
  3685   @{typeof term} prints the type of a term;
  3686 
  3687   @{const const} is the same as @{term const}, but checks that the
  3688   argument is a known logical constant;
  3689 
  3690   @{term_style style term} and @{thm_style style thm} print a term or
  3691   theorem applying a "style" to it
  3692 
  3693   @{ML text}
  3694 
  3695 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3696 definitions, equations, inequations etc., 'concl' printing only the
  3697 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3698 to print the specified premise.  TermStyle.add_style provides an ML
  3699 interface for introducing further styles.  See also the "LaTeX Sugar"
  3700 document practical applications.  The ML antiquotation prints
  3701 type-checked ML expressions verbatim.
  3702 
  3703 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3704 and 'text' support optional locale specification '(in loc)', which
  3705 specifies the default context for interpreting antiquotations.  For
  3706 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3707 
  3708 * Option 'locale=NAME' of antiquotations specifies an alternative
  3709 context interpreting the subsequent argument.  For example: @{thm
  3710 [locale=lattice] inf_assoc}.
  3711 
  3712 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3713 a proof context.
  3714 
  3715 * Proper output of antiquotations for theory commands involving a
  3716 proof context (such as 'locale' or 'theorem (in loc) ...').
  3717 
  3718 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3719 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3720 
  3721 * isatool usedir: new option -C (default true) controls whether option
  3722 -D should include a copy of the original document directory; -C false
  3723 prevents unwanted effects such as copying of administrative CVS data.
  3724 
  3725 
  3726 *** Pure ***
  3727 
  3728 * Considerably improved version of 'constdefs' command.  Now performs
  3729 automatic type-inference of declared constants; additional support for
  3730 local structure declarations (cf. locales and HOL records), see also
  3731 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3732 sequential dependencies of definitions within a single 'constdefs'
  3733 section; moreover, the declared name needs to be an identifier.  If
  3734 all fails, consider to fall back on 'consts' and 'defs' separately.
  3735 
  3736 * Improved indexed syntax and implicit structures.  First of all,
  3737 indexed syntax provides a notational device for subscripted
  3738 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3739 expressions.  Secondly, in a local context with structure
  3740 declarations, number indexes \<^sub>n or the empty index (default
  3741 number 1) refer to a certain fixed variable implicitly; option
  3742 show_structs controls printing of implicit structures.  Typical
  3743 applications of these concepts involve record types and locales.
  3744 
  3745 * New command 'no_syntax' removes grammar declarations (and
  3746 translations) resulting from the given syntax specification, which is
  3747 interpreted in the same manner as for the 'syntax' command.
  3748 
  3749 * 'Advanced' translation functions (parse_translation etc.) may depend
  3750 on the signature of the theory context being presently used for
  3751 parsing/printing, see also isar-ref manual.
  3752 
  3753 * Improved 'oracle' command provides a type-safe interface to turn an
  3754 ML expression of type theory -> T -> term into a primitive rule of
  3755 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3756 is already included here); see also FOL/ex/IffExample.thy;
  3757 INCOMPATIBILITY.
  3758 
  3759 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3760 before); "cI" is no longer bound, use "c.intro" instead.
  3761 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3762 axclasses vs. locales.
  3763 
  3764 * Improved internal renaming of symbolic identifiers -- attach primes
  3765 instead of base 26 numbers.
  3766 
  3767 * New flag show_question_marks controls printing of leading question
  3768 marks in schematic variable names.
  3769 
  3770 * In schematic variable names, *any* symbol following \<^isub> or
  3771 \<^isup> is now treated as part of the base name.  For example, the
  3772 following works without printing of awkward ".0" indexes:
  3773 
  3774   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3775     by simp
  3776 
  3777 * Inner syntax includes (*(*nested*) comments*).
  3778 
  3779 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3780 annotations as "(00...)".
  3781 
  3782 * Clear separation of logical types and nonterminals, where the latter
  3783 may only occur in 'syntax' specifications or type abbreviations.
  3784 Before that distinction was only partially implemented via type class
  3785 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3786 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3787 exotic syntax specifications may require further adaption
  3788 (e.g. Cube/Cube.thy).
  3789 
  3790 * Removed obsolete type class "logic", use the top sort {} instead.
  3791 Note that non-logical types should be declared as 'nonterminals'
  3792 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3793 specifications.
  3794 
  3795 * Attributes 'induct' and 'cases': type or set names may now be
  3796 locally fixed variables as well.
  3797 
  3798 * Simplifier: can now control the depth to which conditional rewriting
  3799 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3800 Limit.
  3801 
  3802 * Simplifier: simplification procedures may now take the current
  3803 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3804 interface), which is very useful for calling the Simplifier
  3805 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3806 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3807 low-level mk_simproc no longer applies Logic.varify internally, to
  3808 allow for use in a context of fixed variables.
  3809 
  3810 * thin_tac now works even if the assumption being deleted contains !!
  3811 or ==>.  More generally, erule now works even if the major premise of
  3812 the elimination rule contains !! or ==>.
  3813 
  3814 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3815 
  3816 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3817 from Pure, which contains all common declarations already.  Both
  3818 theories are defined via plain Isabelle/Isar .thy files.
  3819 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3820 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3821 use isatool fixcpure to adapt your theory and ML sources.
  3822 
  3823 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3824 selections of theorems in named facts via index ranges.
  3825 
  3826 * 'print_theorems': in theory mode, really print the difference
  3827 wrt. the last state (works for interactive theory development only),
  3828 in proof mode print all local facts (cf. 'print_facts');
  3829 
  3830 * 'hide': option '(open)' hides only base names.
  3831 
  3832 * More efficient treatment of intermediate checkpoints in interactive
  3833 theory development.
  3834 
  3835 * Code generator is now invoked via code_module (incremental code
  3836 generation) and code_library (modular code generation, ML structures
  3837 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3838 must be quoted when used as identifiers.
  3839 
  3840 * New 'value' command for reading, evaluating and printing terms using
  3841 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3842 quoted when used as identifier.
  3843 
  3844 
  3845 *** Locales ***
  3846 
  3847 * New commands for the interpretation of locale expressions in
  3848 theories (1), locales (2) and proof contexts (3).  These generate
  3849 proof obligations from the expression specification.  After the
  3850 obligations have been discharged, theorems of the expression are added
  3851 to the theory, target locale or proof context.  The synopsis of the
  3852 commands is a follows:
  3853 
  3854   (1) interpretation expr inst
  3855   (2) interpretation target < expr
  3856   (3) interpret expr inst
  3857 
  3858 Interpretation in theories and proof contexts require a parameter
  3859 instantiation of terms from the current context.  This is applied to
  3860 specifications and theorems of the interpreted expression.
  3861 Interpretation in locales only permits parameter renaming through the
  3862 locale expression.  Interpretation is smart in that interpretations
  3863 that are active already do not occur in proof obligations, neither are
  3864 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3865 inspect active interpretations of a particular locale.  For details,
  3866 see the Isar Reference manual.  Examples can be found in
  3867 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3868 
  3869 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3870 'interpret' instead.
  3871 
  3872 * New context element 'constrains' for adding type constraints to
  3873 parameters.
  3874 
  3875 * Context expressions: renaming of parameters with syntax
  3876 redeclaration.
  3877 
  3878 * Locale declaration: 'includes' disallowed.
  3879 
  3880 * Proper static binding of attribute syntax -- i.e. types / terms /
  3881 facts mentioned as arguments are always those of the locale definition
  3882 context, independently of the context of later invocations.  Moreover,
  3883 locale operations (renaming and type / term instantiation) are applied
  3884 to attribute arguments as expected.
  3885 
  3886 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3887 actual attributes; rare situations may require Attrib.attribute to
  3888 embed those attributes into Attrib.src that lack concrete syntax.
  3889 Attribute implementations need to cooperate properly with the static
  3890 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3891 Attrib.XXX_thm etc. already do the right thing without further
  3892 intervention.  Only unusual applications -- such as "where" or "of"
  3893 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3894 on the context and the facts involved -- may have to assign parsed
  3895 values to argument tokens explicitly.
  3896 
  3897 * Changed parameter management in theorem generation for long goal
  3898 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3899 theorem statement in rare situations.
  3900 
  3901 * Locale inspection command 'print_locale' omits notes elements.  Use
  3902 'print_locale!' to have them included in the output.
  3903 
  3904 
  3905 *** Provers ***
  3906 
  3907 * Provers/hypsubst.ML: improved version of the subst method, for
  3908 single-step rewriting: it now works in bound variable contexts. New is
  3909 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3910 rewrite a different subterm than the original subst method, which is
  3911 still available as 'simplesubst'.
  3912 
  3913 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3914 and quasi orders.
  3915 
  3916 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3917 reflexive-transitive closure of relations.
  3918 
  3919 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3920 limit (previously hard-coded with a value of 20) user-definable.
  3921 
  3922 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3923 is peformed already.  Object-logics merely need to finish their
  3924 initial simpset configuration as before.  INCOMPATIBILITY.
  3925 
  3926 
  3927 *** HOL ***
  3928 
  3929 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3930 
  3931   syntax (epsilon)
  3932     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3933 
  3934 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3935 and x-symbol; use option '-m epsilon' to get it actually printed.
  3936 Moreover, the mathematically important symbolic identifier \<epsilon>
  3937 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3938 
  3939 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3940 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3941 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3942 support corresponding Isar calculations.
  3943 
  3944 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3945 instead of ":".
  3946 
  3947 * theory SetInterval: changed the syntax for open intervals:
  3948 
  3949   Old       New
  3950   {..n(}    {..<n}
  3951   {)n..}    {n<..}
  3952   {m..n(}   {m..<n}
  3953   {)m..n}   {m<..n}
  3954   {)m..n(}  {m<..<n}
  3955 
  3956 The old syntax is still supported but will disappear in the next
  3957 release.  For conversion use the following Emacs search and replace
  3958 patterns (these are not perfect but work quite well):
  3959 
  3960   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3961   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3962 
  3963 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3964 equalities in commutative rings; method 'algebra' provides a generic
  3965 interface.
  3966 
  3967 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3968 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3969 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3970 be a tuple pattern.
  3971 
  3972 Some new syntax forms are available:
  3973 
  3974   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3975   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3976   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3977   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3978 
  3979 The latter form "\<Sum>x < k. e" used to be based on a separate
  3980 function "Summation", which has been discontinued.
  3981 
  3982 * theory Finite_Set: in structured induction proofs, the insert case
  3983 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3984 (insert F x)'.
  3985 
  3986 * The 'refute' command has been extended to support a much larger
  3987 fragment of HOL, including axiomatic type classes, constdefs and
  3988 typedefs, inductive datatypes and recursion.
  3989 
  3990 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3991 Requires zChaff with proof generation to be installed.  See
  3992 HOL/ex/SAT_Examples.thy for examples.
  3993 
  3994 * Datatype induction via method 'induct' now preserves the name of the
  3995 induction variable. For example, when proving P(xs::'a list) by
  3996 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3997 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3998 in unstructured proof scripts.
  3999 
  4000 * Reworked implementation of records.  Improved scalability for
  4001 records with many fields, avoiding performance problems for type
  4002 inference. Records are no longer composed of nested field types, but
  4003 of nested extension types. Therefore the record type only grows linear
  4004 in the number of extensions and not in the number of fields.  The
  4005 top-level (users) view on records is preserved.  Potential
  4006 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4007 old record representation. The type generated for a record is called
  4008 <record_name>_ext_type.
  4009 
  4010 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4011 proofs triggered by a record definition or a simproc (if
  4012 quick_and_dirty is enabled).  Definitions of large records can take
  4013 quite long.
  4014 
  4015 New simproc record_upd_simproc for simplification of multiple record
  4016 updates enabled by default.  Moreover, trivial updates are also
  4017 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4018 occasionally, since simplification is more powerful by default.
  4019 
  4020 * typedef: proper support for polymorphic sets, which contain extra
  4021 type-variables in the term.
  4022 
  4023 * Simplifier: automatically reasons about transitivity chains
  4024 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4025 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4026 old proofs break occasionally as simplification may now solve more
  4027 goals than previously.
  4028 
  4029 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4030 present.  Works for all partial orders (class "order"), in particular
  4031 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4032 just like y <= x.
  4033 
  4034 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4035 bound variable or a constant then the let is unfolded.  Otherwise
  4036 first a is simplified to b, and then f b is simplified to g. If
  4037 possible we abstract b from g arriving at "let x = b in h x",
  4038 otherwise we unfold the let and arrive at g.  The simproc can be
  4039 enabled/disabled by the reference use_let_simproc.  Potential
  4040 INCOMPATIBILITY since simplification is more powerful by default.
  4041 
  4042 * Classical reasoning: the meson method now accepts theorems as arguments.
  4043 
  4044 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4045 jobs to provide advice on the provability of subgoals.
  4046 
  4047 * Theory OrderedGroup and Ring_and_Field: various additions and
  4048 improvements to faciliate calculations involving equalities and
  4049 inequalities.
  4050 
  4051 The following theorems have been eliminated or modified
  4052 (INCOMPATIBILITY):
  4053 
  4054   abs_eq             now named abs_of_nonneg
  4055   abs_of_ge_0        now named abs_of_nonneg
  4056   abs_minus_eq       now named abs_of_nonpos
  4057   imp_abs_id         now named abs_of_nonneg
  4058   imp_abs_neg_id     now named abs_of_nonpos
  4059   mult_pos           now named mult_pos_pos
  4060   mult_pos_le        now named mult_nonneg_nonneg
  4061   mult_pos_neg_le    now named mult_nonneg_nonpos
  4062   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4063   mult_neg           now named mult_neg_neg
  4064   mult_neg_le        now named mult_nonpos_nonpos
  4065 
  4066 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4067      
  4068      zero_le_square
  4069      not_square_less_zero 
  4070 
  4071   The following lemmas have been deleted from Real/RealPow:
  4072   
  4073      realpow_zero_zero
  4074      realpow_two
  4075      realpow_less
  4076      zero_le_power
  4077      realpow_two_le
  4078      abs_realpow_two
  4079      realpow_two_abs     
  4080 
  4081 * Theory Parity: added rules for simplifying exponents.
  4082 
  4083 * Theory List:
  4084 
  4085 The following theorems have been eliminated or modified
  4086 (INCOMPATIBILITY):
  4087 
  4088   list_all_Nil       now named list_all.simps(1)
  4089   list_all_Cons      now named list_all.simps(2)
  4090   list_all_conv      now named list_all_iff
  4091   set_mem_eq         now named mem_iff
  4092 
  4093 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4094 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4095 
  4096 
  4097 *** HOL-Complex ***
  4098 
  4099 * Theory RealDef: better support for embedding natural numbers and
  4100 integers in the reals.
  4101 
  4102 The following theorems have been eliminated or modified
  4103 (INCOMPATIBILITY):
  4104 
  4105   exp_ge_add_one_self  now requires no hypotheses
  4106   real_of_int_add      reversed direction of equality (use [symmetric])
  4107   real_of_int_minus    reversed direction of equality (use [symmetric])
  4108   real_of_int_diff     reversed direction of equality (use [symmetric])
  4109   real_of_int_mult     reversed direction of equality (use [symmetric])
  4110 
  4111 * Theory RComplete: expanded support for floor and ceiling functions.
  4112 
  4113 * Theory Ln is new, with properties of the natural logarithm
  4114 
  4115 * Hyperreal: There is a new type constructor "star" for making
  4116 nonstandard types.  The old type names are now type synonyms:
  4117 
  4118   hypreal = real star
  4119   hypnat = nat star
  4120   hcomplex = complex star
  4121 
  4122 * Hyperreal: Many groups of similarly-defined constants have been
  4123 replaced by polymorphic versions (INCOMPATIBILITY):
  4124 
  4125   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4126 
  4127   starset      <-- starsetNat, starsetC
  4128   *s*          <-- *sNat*, *sc*
  4129   starset_n    <-- starsetNat_n, starsetC_n
  4130   *sn*         <-- *sNatn*, *scn*
  4131   InternalSets <-- InternalNatSets, InternalCSets
  4132 
  4133   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4134   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4135   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4136   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4137   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4138 
  4139 * Hyperreal: Many type-specific theorems have been removed in favor of
  4140 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4141 
  4142   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4143   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4144   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4145   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4146   right_minus <-- hypreal_add_minus
  4147   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4148   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4149   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4150   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4151   mult_1_right <-- hcomplex_mult_one_right
  4152   mult_zero_left <-- hcomplex_mult_zero_left
  4153   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4154   right_distrib <-- hypnat_add_mult_distrib2
  4155   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4156   right_inverse <-- hypreal_mult_inverse
  4157   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4158   order_refl <-- {hypreal,hypnat}_le_refl
  4159   order_trans <-- {hypreal,hypnat}_le_trans
  4160   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4161   order_less_le <-- {hypreal,hypnat}_less_le
  4162   linorder_linear <-- {hypreal,hypnat}_le_linear
  4163   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4164   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4165   add_nonneg_nonneg <-- hypreal_le_add_order
  4166 
  4167 * Hyperreal: Separate theorems having to do with type-specific
  4168 versions of constants have been merged into theorems that apply to the
  4169 new polymorphic constants (INCOMPATIBILITY):
  4170 
  4171   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4172   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4173   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4174   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4175   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4176   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4177   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4178   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4179   STAR_diff <-- {STAR,STARC}_diff
  4180   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4181     STARC_hcomplex_of_complex}_image_subset
  4182   starset_n_Un <-- starset{Nat,C}_n_Un
  4183   starset_n_Int <-- starset{Nat,C}_n_Int
  4184   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4185   starset_n_diff <-- starset{Nat,C}_n_diff
  4186   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4187   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4188   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4189   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4190   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4191   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4192   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4193   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4194   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4195   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4196   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4197   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4198   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4199   starfun_diff <-- starfun{C,RC,CR}_diff
  4200   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4201   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4202   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4203   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4204   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4205   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4206   starfun_Id <-- starfunC_Id
  4207   starfun_approx <-- starfun{Nat,CR}_approx
  4208   starfun_capprox <-- starfun{C,RC}_capprox
  4209   starfun_abs <-- starfunNat_rabs
  4210   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4211   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4212   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4213   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4214   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4215   starfun_add_approx <-- starfunCR_add_approx
  4216   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4217   starfun_divide <-- starfun{C,CR,RC}_divide
  4218   starfun_n <-- starfun{Nat,C}_n
  4219   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4220   starfun_n_add <-- starfun{Nat,C}_n_add
  4221   starfun_n_add_minus <-- starfunNat_n_add_minus
  4222   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4223   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4224   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4225 
  4226   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4227   star_n_minus <-- {hypreal,hcomplex}_minus
  4228   star_n_diff <-- {hypreal,hcomplex}_diff
  4229   star_n_mult <-- {hypreal,hcomplex}_mult
  4230   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4231   star_n_le <-- {hypreal,hypnat}_le
  4232   star_n_less <-- {hypreal,hypnat}_less
  4233   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4234   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4235   star_n_abs <-- hypreal_hrabs
  4236   star_n_divide <-- hcomplex_divide
  4237 
  4238   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4239   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4240   star_of_diff <-- hypreal_of_real_diff
  4241   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4242   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4243   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4244   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4245   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4246   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4247   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4248   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4249   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4250   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4251   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4252   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4253   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4254   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4255   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4256   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4257   star_of_power <-- hypreal_of_real_power
  4258   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4259 
  4260 * Hyperreal: new method "transfer" that implements the transfer
  4261 principle of nonstandard analysis. With a subgoal that mentions
  4262 nonstandard types like "'a star", the command "apply transfer"
  4263 replaces it with an equivalent one that mentions only standard types.
  4264 To be successful, all free variables must have standard types; non-
  4265 standard variables must have explicit universal quantifiers.
  4266 
  4267 * Hyperreal: A theory of Taylor series.
  4268 
  4269 
  4270 *** HOLCF ***
  4271 
  4272 * Discontinued special version of 'constdefs' (which used to support
  4273 continuous functions) in favor of the general Pure one with full
  4274 type-inference.
  4275 
  4276 * New simplification procedure for solving continuity conditions; it
  4277 is much faster on terms with many nested lambda abstractions (cubic
  4278 instead of exponential time).
  4279 
  4280 * New syntax for domain package: selector names are now optional.
  4281 Parentheses should be omitted unless argument is lazy, for example:
  4282 
  4283   domain 'a stream = cons "'a" (lazy "'a stream")
  4284 
  4285 * New command 'fixrec' for defining recursive functions with pattern
  4286 matching; defining multiple functions with mutual recursion is also
  4287 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4288 sinr, or any data constructor defined by the domain package. The given
  4289 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4290 syntax and examples.
  4291 
  4292 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4293 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4294 but the proof obligation additionally includes an admissibility
  4295 requirement. The packages generate instances of class cpo or pcpo,
  4296 with continuity and strictness theorems for Rep and Abs.
  4297 
  4298 * HOLCF: Many theorems have been renamed according to a more standard naming
  4299 scheme (INCOMPATIBILITY):
  4300 
  4301   foo_inject:  "foo$x = foo$y ==> x = y"
  4302   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4303   foo_less:    "(foo$x << foo$y) = (x << y)"
  4304   foo_strict:  "foo$UU = UU"
  4305   foo_defined: "... ==> foo$x ~= UU"
  4306   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4307 
  4308 
  4309 *** ZF ***
  4310 
  4311 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4312 including the First Isomorphism Theorem (on quotienting by the kernel
  4313 of a homomorphism).
  4314 
  4315 * ZF/Simplifier: install second copy of type solver that actually
  4316 makes use of TC rules declared to Isar proof contexts (or locales);
  4317 the old version is still required for ML proof scripts.
  4318 
  4319 
  4320 *** Cube ***
  4321 
  4322 * Converted to Isar theory format; use locales instead of axiomatic
  4323 theories.
  4324 
  4325 
  4326 *** ML ***
  4327 
  4328 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4329 for ||>, ||>>, |>>,
  4330 
  4331 * Pure/library.ML no longer defines its own option datatype, but uses
  4332 that of the SML basis, which has constructors NONE and SOME instead of
  4333 None and Some, as well as exception Option.Option instead of OPTION.
  4334 The functions the, if_none, is_some, is_none have been adapted
  4335 accordingly, while Option.map replaces apsome.
  4336 
  4337 * Pure/library.ML: the exception LIST has been given up in favour of
  4338 the standard exceptions Empty and Subscript, as well as
  4339 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4340 superceded by the standard hd and tl functions etc.
  4341 
  4342 A number of basic list functions are no longer exported to the ML
  4343 toplevel, as they are variants of predefined functions.  The following
  4344 suggests how one can translate existing code:
  4345 
  4346     rev_append xs ys = List.revAppend (xs, ys)
  4347     nth_elem (i, xs) = List.nth (xs, i)
  4348     last_elem xs = List.last xs
  4349     flat xss = List.concat xss
  4350     seq fs = List.app fs
  4351     partition P xs = List.partition P xs
  4352     mapfilter f xs = List.mapPartial f xs
  4353 
  4354 * Pure/library.ML: several combinators for linear functional
  4355 transformations, notably reverse application and composition:
  4356 
  4357   x |> f                f #> g
  4358   (x, y) |-> f          f #-> g
  4359 
  4360 * Pure/library.ML: introduced/changed precedence of infix operators:
  4361 
  4362   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4363   infix 2 ?;
  4364   infix 3 o oo ooo oooo;
  4365   infix 4 ~~ upto downto;
  4366 
  4367 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4368 infix operators.
  4369 
  4370 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4371 fold_map support linear functional transformations and nesting.  For
  4372 example:
  4373 
  4374   fold f [x1, ..., xN] y =
  4375     y |> f x1 |> ... |> f xN
  4376 
  4377   (fold o fold) f [xs1, ..., xsN] y =
  4378     y |> fold f xs1 |> ... |> fold f xsN
  4379 
  4380   fold f [x1, ..., xN] =
  4381     f x1 #> ... #> f xN
  4382 
  4383   (fold o fold) f [xs1, ..., xsN] =
  4384     fold f xs1 #> ... #> fold f xsN
  4385 
  4386 * Pure/library.ML: the following selectors on type 'a option are
  4387 available:
  4388 
  4389   the:               'a option -> 'a  (*partial*)
  4390   these:             'a option -> 'a  where 'a = 'b list
  4391   the_default: 'a -> 'a option -> 'a
  4392   the_list:          'a option -> 'a list
  4393 
  4394 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4395 basic operations for association lists, following natural argument
  4396 order; moreover the explicit equality predicate passed here avoids
  4397 potentially expensive polymorphic runtime equality checks.
  4398 The old functions may be expressed as follows:
  4399 
  4400   assoc = uncurry (AList.lookup (op =))
  4401   assocs = these oo AList.lookup (op =)
  4402   overwrite = uncurry (AList.update (op =)) o swap
  4403 
  4404 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4405 
  4406   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4407   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4408 
  4409 replacing make_keylist and keyfilter (occassionally used)
  4410 Naive rewrites:
  4411 
  4412   make_keylist = AList.make
  4413   keyfilter = AList.find (op =)
  4414 
  4415 * eq_fst and eq_snd now take explicit equality parameter, thus
  4416   avoiding eqtypes. Naive rewrites:
  4417 
  4418     eq_fst = eq_fst (op =)
  4419     eq_snd = eq_snd (op =)
  4420 
  4421 * Removed deprecated apl and apr (rarely used).
  4422   Naive rewrites:
  4423 
  4424     apl (n, op) =>>= curry op n
  4425     apr (op, m) =>>= fn n => op (n, m)
  4426 
  4427 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4428 provides a reasonably efficient light-weight implementation of sets as
  4429 lists.
  4430 
  4431 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4432 few new operations; existing lookup and update are now curried to
  4433 follow natural argument order (for use with fold etc.);
  4434 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4435 
  4436 * Pure/General: output via the Isabelle channels of
  4437 writeln/warning/error etc. is now passed through Output.output, with a
  4438 hook for arbitrary transformations depending on the print_mode
  4439 (cf. Output.add_mode -- the first active mode that provides a output
  4440 function wins).  Already formatted output may be embedded into further
  4441 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4442 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4443 accommodate easy composition of diagnostic messages etc.  Programmers
  4444 rarely need to care about Output.output or Output.raw at all, with
  4445 some notable exceptions: Output.output is required when bypassing the
  4446 standard channels (writeln etc.), or in token translations to produce
  4447 properly formatted results; Output.raw is required when capturing
  4448 already output material that will eventually be presented to the user
  4449 a second time.  For the default print mode, both Output.output and
  4450 Output.raw have no effect.
  4451 
  4452 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4453 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4454 cumulative results are displayed at the end of a batch session.
  4455 
  4456 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4457 replaced by File.platform_path and File.shell_path (with appropriate
  4458 hooks).  This provides a clean interface for unusual systems where the
  4459 internal and external process view of file names are different.
  4460 
  4461 * Pure: more efficient orders for basic syntactic entities: added
  4462 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4463 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4464 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4465 orders now -- potential INCOMPATIBILITY for code that depends on a
  4466 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4467 Library.sort_strings on result).
  4468 
  4469 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4470 fold_types traverse types/terms from left to right, observing natural
  4471 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4472 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4473 
  4474 * Pure: name spaces have been refined, with significant changes of the
  4475 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4476 to extern(_table).  The plain name entry path is superceded by a
  4477 general 'naming' context, which also includes the 'policy' to produce
  4478 a fully qualified name and external accesses of a fully qualified
  4479 name; NameSpace.extend is superceded by context dependent
  4480 Sign.declare_name.  Several theory and proof context operations modify
  4481 the naming context.  Especially note Theory.restore_naming and
  4482 ProofContext.restore_naming to get back to a sane state; note that
  4483 Theory.add_path is no longer sufficient to recover from
  4484 Theory.absolute_path in particular.
  4485 
  4486 * Pure: new flags short_names (default false) and unique_names
  4487 (default true) for controlling output of qualified names.  If
  4488 short_names is set, names are printed unqualified.  If unique_names is
  4489 reset, the name prefix is reduced to the minimum required to achieve
  4490 the original result when interning again, even if there is an overlap
  4491 with earlier declarations.
  4492 
  4493 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4494 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4495 (useful for printing error messages).  INCOMPATIBILITY.
  4496 
  4497 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4498 Theory.theory are now identified, referring to the universal
  4499 Context.theory (see Pure/context.ML).  Actual signature and theory
  4500 content is managed as theory data.  The old code and interfaces were
  4501 spread over many files and structures; the new arrangement introduces
  4502 considerable INCOMPATIBILITY to gain more clarity:
  4503 
  4504   Context -- theory management operations (name, identity, inclusion,
  4505     parents, ancestors, merge, etc.), plus generic theory data;
  4506 
  4507   Sign -- logical signature and syntax operations (declaring consts,
  4508     types, etc.), plus certify/read for common entities;
  4509 
  4510   Theory -- logical theory operations (stating axioms, definitions,
  4511     oracles), plus a copy of logical signature operations (consts,
  4512     types, etc.); also a few basic management operations (Theory.copy,
  4513     Theory.merge, etc.)
  4514 
  4515 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4516 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4517 for convenience -- they merely return the theory.
  4518 
  4519 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4520 
  4521 * Pure: the Isar proof context type is already defined early in Pure
  4522 as Context.proof (note that ProofContext.context and Proof.context are
  4523 aliases, where the latter is the preferred name).  This enables other
  4524 Isabelle components to refer to that type even before Isar is present.
  4525 
  4526 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4527 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4528 any of these kinds.  For example, Sign.intern typeK is now
  4529 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4530 Theory.hide_types.  Also note that former
  4531 Theory.hide_classes/types/consts are now
  4532 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4533 internalize their arguments!  INCOMPATIBILITY.
  4534 
  4535 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4536 datatype thmref (with constructors Name and NameSelection) instead of
  4537 plain string -- INCOMPATIBILITY;
  4538 
  4539 * Pure: cases produced by proof methods specify options, where NONE
  4540 means to remove case bindings -- INCOMPATIBILITY in
  4541 (RAW_)METHOD_CASES.
  4542 
  4543 * Pure: the following operations retrieve axioms or theorems from a
  4544 theory node or theory hierarchy, respectively:
  4545 
  4546   Theory.axioms_of: theory -> (string * term) list
  4547   Theory.all_axioms_of: theory -> (string * term) list
  4548   PureThy.thms_of: theory -> (string * thm) list
  4549   PureThy.all_thms_of: theory -> (string * thm) list
  4550 
  4551 * Pure: print_tac now outputs the goal through the trace channel.
  4552 
  4553 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4554 Reference Toplevel.debug (default false) controls detailed printing
  4555 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4556 controls execution profiling -- set to 1 for time and 2 for space
  4557 (both increase the runtime).
  4558 
  4559 * Isar session: The initial use of ROOT.ML is now always timed,
  4560 i.e. the log will show the actual process times, in contrast to the
  4561 elapsed wall-clock time that the outer shell wrapper produces.
  4562 
  4563 * Simplifier: improved handling of bound variables (nameless
  4564 representation, avoid allocating new strings).  Simprocs that invoke
  4565 the Simplifier recursively should use Simplifier.inherit_bounds to
  4566 avoid local name clashes.  Failure to do so produces warnings
  4567 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4568 for further details.
  4569 
  4570 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4571 bindings for all theorems stored within a given theory; this may help
  4572 in porting non-Isar theories to Isar ones, while keeping ML proof
  4573 scripts for the time being.
  4574 
  4575 * ML operator HTML.with_charset specifies the charset begin used for
  4576 generated HTML files.  For example:
  4577 
  4578   HTML.with_charset "utf-8" use_thy "Hebrew";
  4579   HTML.with_charset "utf-8" use_thy "Chinese";
  4580 
  4581 
  4582 *** System ***
  4583 
  4584 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4585 isabelle, isatool etc.).
  4586 
  4587 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4588 isatool doc, isatool mkdir, display_drafts etc.).
  4589 
  4590 * isatool usedir: option -f allows specification of the ML file to be
  4591 used by Isabelle; default is ROOT.ML.
  4592 
  4593 * New isatool version outputs the version identifier of the Isabelle
  4594 distribution being used.
  4595 
  4596 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4597 (containing Boolean satisfiability problems) into Isabelle/HOL
  4598 theories.
  4599 
  4600 
  4601 
  4602 New in Isabelle2004 (April 2004)
  4603 --------------------------------
  4604 
  4605 *** General ***
  4606 
  4607 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4608   Replaces linorder.ML.
  4609 
  4610 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4611   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4612   (\<a>...\<z>), are now considered normal letters, and can therefore
  4613   be used anywhere where an ASCII letter (a...zA...Z) has until
  4614   now. COMPATIBILITY: This obviously changes the parsing of some
  4615   terms, especially where a symbol has been used as a binder, say
  4616   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4617   as an identifier.  Fix it by inserting a space around former
  4618   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4619   existing theory and ML files.
  4620 
  4621 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4622 
  4623 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4624   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4625   a normal (but invisible) letter. For multiple letter subscripts repeat
  4626   \<^isub> like this: x\<^isub>1\<^isub>2.
  4627 
  4628 * Pure: There are now sub-/superscripts that can span more than one
  4629   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4630   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4631   superscript. The new control characters are not identifier parts.
  4632 
  4633 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4634   content of "..." to the latex file instead of \isacntrl... . The "..."
  4635   may consist of any printable characters excluding the end bracket >.
  4636 
  4637 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4638   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4639   declare constants "final", which prevents their being given a definition
  4640   later.  It is useful for constants whose behaviour is fixed axiomatically
  4641   rather than definitionally, such as the meta-logic connectives.
  4642 
  4643 * Pure: 'instance' now handles general arities with general sorts
  4644   (i.e. intersections of classes),
  4645 
  4646 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4647   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4648   It can be changed to alter the colors/layout of generated pages.
  4649 
  4650 
  4651 *** Isar ***
  4652 
  4653 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4654   cut_tac, subgoal_tac and thin_tac:
  4655   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4656     locales are no longer forced to write Isar proof scripts.
  4657     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4658     emulations.
  4659   - INCOMPATIBILITY: names of variables to be instantiated may no
  4660     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4661     This is consistent with the instantiation attribute "where".
  4662 
  4663 * Attributes "where" and "of":
  4664   - Now take type variables of instantiated theorem into account when reading
  4665     the instantiation string.  This fixes a bug that caused instantiated
  4666     theorems to have too special types in some circumstances.
  4667   - "where" permits explicit instantiations of type variables.
  4668 
  4669 * Calculation commands "moreover" and "also" no longer interfere with
  4670   current facts ("this"), admitting arbitrary combinations with "then"
  4671   and derived forms.
  4672 
  4673 * Locales:
  4674   - Goal statements involving the context element "includes" no longer
  4675     generate theorems with internal delta predicates (those ending on
  4676     "_axioms") in the premise.
  4677     Resolve particular premise with <locale>.intro to obtain old form.
  4678   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4679     specification and "includes" elements in goal statement.
  4680   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4681     [intro?] and [elim?] (respectively) by default.
  4682   - Experimental command for instantiation of locales in proof contexts:
  4683         instantiate <label>[<attrs>]: <loc>
  4684     Instantiates locale <loc> and adds all its theorems to the current context
  4685     taking into account their attributes.  Label and attrs are optional
  4686     modifiers, like in theorem declarations.  If present, names of
  4687     instantiated theorems are qualified with <label>, and the attributes
  4688     <attrs> are applied after any attributes these theorems might have already.
  4689       If the locale has assumptions, a chained fact of the form
  4690     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4691     are derived.  The command does not support old-style locales declared
  4692     with "locale (open)".
  4693       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4694 
  4695 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4696   (Isar) contexts.
  4697 
  4698 
  4699 *** HOL ***
  4700 
  4701 * Proof import: new image HOL4 contains the imported library from
  4702   the HOL4 system with about 2500 theorems. It is imported by
  4703   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4704   can be used like any other Isabelle image.  See
  4705   HOL/Import/HOL/README for more information.
  4706 
  4707 * Simplifier:
  4708   - Much improved handling of linear and partial orders.
  4709     Reasoners for linear and partial orders are set up for type classes
  4710     "linorder" and "order" respectively, and are added to the default simpset
  4711     as solvers.  This means that the simplifier can build transitivity chains
  4712     to solve goals from the assumptions.
  4713   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4714     of blast or auto after simplification become unnecessary because the goal
  4715     is solved by simplification already.
  4716 
  4717 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4718     all proved in axiomatic type classes for semirings, rings and fields.
  4719 
  4720 * Numerics:
  4721   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4722     now formalized using the Ring_and_Field theory mentioned above.
  4723   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4724     than before, because now they are set up once in a generic manner.
  4725   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4726     Look for the general versions in Ring_and_Field (and Power if they concern
  4727     exponentiation).
  4728 
  4729 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4730 
  4731 * Records:
  4732   - Record types are now by default printed with their type abbreviation
  4733     instead of the list of all field types. This can be configured via
  4734     the reference "print_record_type_abbr".
  4735   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4736     (not enabled by default).
  4737   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4738     EX x. x = sel r to True (not enabled by default).
  4739   - Tactic "record_split_simp_tac" to split and simplify records added.
  4740 
  4741 * 'specification' command added, allowing for definition by
  4742   specification.  There is also an 'ax_specification' command that
  4743   introduces the new constants axiomatically.
  4744 
  4745 * arith(_tac) is now able to generate counterexamples for reals as well.
  4746 
  4747 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4748 
  4749 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4750   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4751 
  4752 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4753   matrix theory to linear programming.
  4754 
  4755 * Unions and Intersections:
  4756   The latex output syntax of UN and INT has been changed
  4757   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4758   i.e. the index formulae has become a subscript.
  4759   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4760 
  4761 * Unions and Intersections over Intervals:
  4762   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4763   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4764   like in normal math, and corresponding versions for < and for intersection.
  4765 
  4766 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4767   lexicographic dictonary ordering has been added as "lexord".
  4768 
  4769 * ML: the legacy theory structures Int and List have been removed. They had
  4770   conflicted with ML Basis Library structures having the same names.
  4771 
  4772 * 'refute' command added to search for (finite) countermodels.  Only works
  4773   for a fragment of HOL.  The installation of an external SAT solver is
  4774   highly recommended.  See "HOL/Refute.thy" for details.
  4775 
  4776 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4777   formulae under an assignment of free variables to random values.
  4778   In contrast to 'refute', it can deal with inductive datatypes,
  4779   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4780   for examples.
  4781 
  4782 
  4783 *** HOLCF ***
  4784 
  4785 * Streams now come with concatenation and are part of the HOLCF image
  4786 
  4787 
  4788 
  4789 New in Isabelle2003 (May 2003)
  4790 ------------------------------
  4791 
  4792 *** General ***
  4793 
  4794 * Provers/simplifier:
  4795 
  4796   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4797     Assumptions are now subject to complete mutual simplification,
  4798     not just from left to right. The simplifier now preserves
  4799     the order of assumptions.
  4800 
  4801     Potential INCOMPATIBILITY:
  4802 
  4803     -- simp sometimes diverges where the old version did
  4804        not, e.g. invoking simp on the goal
  4805 
  4806         [| P (f x); y = x; f x = f y |] ==> Q
  4807 
  4808        now gives rise to the infinite reduction sequence
  4809 
  4810         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4811 
  4812        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4813        kind of problem.
  4814 
  4815     -- Tactics combining classical reasoner and simplification (such as auto)
  4816        are also affected by this change, because many of them rely on
  4817        simp. They may sometimes diverge as well or yield a different numbers
  4818        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4819        in case of problems. Sometimes subsequent calls to the classical
  4820        reasoner will fail because a preceeding call to the simplifier too
  4821        eagerly simplified the goal, e.g. deleted redundant premises.
  4822 
  4823   - The simplifier trace now shows the names of the applied rewrite rules
  4824 
  4825   - You can limit the number of recursive invocations of the simplifier
  4826     during conditional rewriting (where the simplifie tries to solve the
  4827     conditions before applying the rewrite rule):
  4828     ML "simp_depth_limit := n"
  4829     where n is an integer. Thus you can force termination where previously
  4830     the simplifier would diverge.
  4831 
  4832   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4833 
  4834   - No longer aborts on failed congruence proof.  Instead, the
  4835     congruence is ignored.
  4836 
  4837 * Pure: New generic framework for extracting programs from constructive
  4838   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4839   as HOL/Extraction for some case studies.
  4840 
  4841 * Pure: The main goal of the proof state is no longer shown by default, only
  4842 the subgoals. This behaviour is controlled by a new flag.
  4843    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4844 (ML: Proof.show_main_goal).
  4845 
  4846 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4847 rules whose conclusion matches subgoal 1:
  4848       PG menu: Isabelle/Isar -> Show me -> matching rules
  4849 The rules are ordered by how closely they match the subgoal.
  4850 In particular, rules that solve a subgoal outright are displayed first
  4851 (or rather last, the way they are printed).
  4852 (ML: ProofGeneral.print_intros())
  4853 
  4854 * Pure: New flag trace_unify_fail causes unification to print
  4855 diagnostic information (PG: in trace buffer) when it fails. This is
  4856 useful for figuring out why single step proofs like rule, erule or
  4857 assumption failed.
  4858 
  4859 * Pure: Locale specifications now produce predicate definitions
  4860 according to the body of text (covering assumptions modulo local
  4861 definitions); predicate "loc_axioms" covers newly introduced text,
  4862 while "loc" is cumulative wrt. all included locale expressions; the
  4863 latter view is presented only on export into the global theory
  4864 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4865 on the old view without predicates;
  4866 
  4867 * Pure: predefined locales "var" and "struct" are useful for sharing
  4868 parameters (as in CASL, for example); just specify something like
  4869 ``var x + var y + struct M'' as import;
  4870 
  4871 * Pure: improved thms_containing: proper indexing of facts instead of
  4872 raw theorems; check validity of results wrt. current name space;
  4873 include local facts of proof configuration (also covers active
  4874 locales), cover fixed variables in index; may use "_" in term
  4875 specification; an optional limit for the number of printed facts may
  4876 be given (the default is 40);
  4877 
  4878 * Pure: disallow duplicate fact bindings within new-style theory files
  4879 (batch-mode only);
  4880 
  4881 * Provers: improved induct method: assumptions introduced by case
  4882 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4883 the goal statement); "foo" still refers to all facts collectively;
  4884 
  4885 * Provers: the function blast.overloaded has been removed: all constants
  4886 are regarded as potentially overloaded, which improves robustness in exchange
  4887 for slight decrease in efficiency;
  4888 
  4889 * Provers/linorder: New generic prover for transitivity reasoning over
  4890 linear orders.  Note: this prover is not efficient!
  4891 
  4892 * Isar: preview of problems to finish 'show' now produce an error
  4893 rather than just a warning (in interactive mode);
  4894 
  4895 
  4896 *** HOL ***
  4897 
  4898 * arith(_tac)
  4899 
  4900  - Produces a counter example if it cannot prove a goal.
  4901    Note that the counter example may be spurious if the goal is not a formula
  4902    of quantifier-free linear arithmetic.
  4903    In ProofGeneral the counter example appears in the trace buffer.
  4904 
  4905  - Knows about div k and mod k where k is a numeral of type nat or int.
  4906 
  4907  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4908    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4909    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4910 
  4911 * simp's arithmetic capabilities have been enhanced a bit: it now
  4912 takes ~= in premises into account (by performing a case split);
  4913 
  4914 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4915 are distributed over a sum of terms;
  4916 
  4917 * New tactic "trans_tac" and method "trans" instantiate
  4918 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4919 "<=", "<" and "=").
  4920 
  4921 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4922 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4923 
  4924 * 'typedef' command has new option "open" to suppress the set
  4925 definition;
  4926 
  4927 * functions Min and Max on finite sets have been introduced (theory
  4928 Finite_Set);
  4929 
  4930 * attribute [symmetric] now works for relations as well; it turns
  4931 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4932 
  4933 * induct over a !!-quantified statement (say !!x1..xn):
  4934   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4935 
  4936 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4937 %x. None. Warning: empty_def now refers to the previously hidden definition
  4938 of the empty set.
  4939 
  4940 * Algebra: formalization of classical algebra.  Intended as base for
  4941 any algebraic development in Isabelle.  Currently covers group theory
  4942 (up to Sylow's theorem) and ring theory (Universal Property of
  4943 Univariate Polynomials).  Contributions welcome;
  4944 
  4945 * GroupTheory: deleted, since its material has been moved to Algebra;
  4946 
  4947 * Complex: new directory of the complex numbers with numeric constants,
  4948 nonstandard complex numbers, and some complex analysis, standard and
  4949 nonstandard (Jacques Fleuriot);
  4950 
  4951 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4952 
  4953 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4954 Fleuriot);
  4955 
  4956 * Real/HahnBanach: updated and adapted to locales;
  4957 
  4958 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4959 Gray and Kramer);
  4960 
  4961 * UNITY: added the Meier-Sanders theory of progress sets;
  4962 
  4963 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4964 as abstract algorithms, instantiated to the JVM;
  4965 
  4966 * Bali: Java source language formalization. Type system, operational
  4967 semantics, axiomatic semantics. Supported language features:
  4968 classes, interfaces, objects,virtual methods, static methods,
  4969 static/instance fields, arrays, access modifiers, definite
  4970 assignment, exceptions.
  4971 
  4972 
  4973 *** ZF ***
  4974 
  4975 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4976 universe, etc.);
  4977 
  4978 * Main ZF: virtually all theories converted to new-style format;
  4979 
  4980 
  4981 *** ML ***
  4982 
  4983 * Pure: Tactic.prove provides sane interface for internal proofs;
  4984 omits the infamous "standard" operation, so this is more appropriate
  4985 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4986 
  4987 * Pure: improved error reporting of simprocs;
  4988 
  4989 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4990 up simprocs;
  4991 
  4992 
  4993 *** Document preparation ***
  4994 
  4995 * uses \par instead of \\ for line breaks in theory text. This may
  4996 shift some page breaks in large documents. To get the old behaviour
  4997 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4998 
  4999 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5000 other packages
  5001 
  5002 * \<euro> now needs package babel/greek instead of marvosym (which
  5003 broke \Rightarrow)
  5004 
  5005 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5006 textcomp package)
  5007 
  5008 
  5009 
  5010 New in Isabelle2002 (March 2002)
  5011 --------------------------------
  5012 
  5013 *** Document preparation ***
  5014 
  5015 * greatly simplified document preparation setup, including more
  5016 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5017 instructive isatool mkdir; users should basically be able to get
  5018 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5019 users may run a separate document processing stage manually like this:
  5020 "isatool usedir -D output HOL Test && isatool document Test/output";
  5021 
  5022 * theory dependency graph may now be incorporated into documents;
  5023 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5024 with \includegraphics of LaTeX;
  5025 
  5026 * proper spacing of consecutive markup elements, especially text
  5027 blocks after section headings;
  5028 
  5029 * support bold style (for single symbols only), input syntax is like
  5030 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5031 
  5032 * \<bullet> is now output as bold \cdot by default, which looks much
  5033 better in printed text;
  5034 
  5035 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5036 note that these symbols are currently unavailable in Proof General /
  5037 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5038 
  5039 * isatool latex no longer depends on changed TEXINPUTS, instead
  5040 isatool document copies the Isabelle style files to the target
  5041 location;
  5042 
  5043 
  5044 *** Isar ***
  5045 
  5046 * Pure/Provers: improved proof by cases and induction;
  5047   - 'case' command admits impromptu naming of parameters (such as
  5048     "case (Suc n)");
  5049   - 'induct' method divinates rule instantiation from the inductive
  5050     claim; no longer requires excessive ?P bindings for proper
  5051     instantiation of cases;
  5052   - 'induct' method properly enumerates all possibilities of set/type
  5053     rules; as a consequence facts may be also passed through *type*
  5054     rules without further ado;
  5055   - 'induct' method now derives symbolic cases from the *rulified*
  5056     rule (before it used to rulify cases stemming from the internal
  5057     atomized version); this means that the context of a non-atomic
  5058     statement becomes is included in the hypothesis, avoiding the
  5059     slightly cumbersome show "PROP ?case" form;
  5060   - 'induct' may now use elim-style induction rules without chaining
  5061     facts, using ``missing'' premises from the goal state; this allows
  5062     rules stemming from inductive sets to be applied in unstructured
  5063     scripts, while still benefitting from proper handling of non-atomic
  5064     statements; NB: major inductive premises need to be put first, all
  5065     the rest of the goal is passed through the induction;
  5066   - 'induct' proper support for mutual induction involving non-atomic
  5067     rule statements (uses the new concept of simultaneous goals, see
  5068     below);
  5069   - append all possible rule selections, but only use the first
  5070     success (no backtracking);
  5071   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5072   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5073   - added 'print_induct_rules' (covered by help item in recent Proof
  5074     General versions);
  5075   - moved induct/cases attributes to Pure, methods to Provers;
  5076   - generic method setup instantiated for FOL and HOL;
  5077 
  5078 * Pure: support multiple simultaneous goal statements, for example
  5079 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5080 meta-level mechanism, this acts as if several individual goals had
  5081 been stated separately; in particular common proof methods need to be
  5082 repeated in order to cover all claims; note that a single elimination
  5083 step is *not* sufficient to establish the two conjunctions, so this
  5084 fails:
  5085 
  5086   assume "A & B" then have A and B ..   (*".." fails*)
  5087 
  5088 better use "obtain" in situations as above; alternative refer to
  5089 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5090 
  5091 * Pure: proper integration with ``locales''; unlike the original
  5092 version by Florian Kammller, Isar locales package high-level proof
  5093 contexts rather than raw logical ones (e.g. we admit to include
  5094 attributes everywhere); operations on locales include merge and
  5095 rename; support for implicit arguments (``structures''); simultaneous
  5096 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5097 some examples;
  5098 
  5099 * Pure: the following commands have been ``localized'', supporting a
  5100 target locale specification "(in name)": 'lemma', 'theorem',
  5101 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5102 stored both within the locale and at the theory level (exported and
  5103 qualified by the locale name);
  5104 
  5105 * Pure: theory goals may now be specified in ``long'' form, with
  5106 ad-hoc contexts consisting of arbitrary locale elements. for example
  5107 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5108 definitions may be given, too); the result is a meta-level rule with
  5109 the context elements being discharged in the obvious way;
  5110 
  5111 * Pure: new proof command 'using' allows to augment currently used
  5112 facts after a goal statement ('using' is syntactically analogous to
  5113 'apply', but acts on the goal's facts only); this allows chained facts
  5114 to be separated into parts given before and after a claim, as in
  5115 ``from a and b have C using d and e <proof>'';
  5116 
  5117 * Pure: renamed "antecedent" case to "rule_context";
  5118 
  5119 * Pure: new 'judgment' command records explicit information about the
  5120 object-logic embedding (used by several tools internally); no longer
  5121 use hard-wired "Trueprop";
  5122 
  5123 * Pure: added 'corollary' command;
  5124 
  5125 * Pure: fixed 'token_translation' command;
  5126 
  5127 * Pure: removed obsolete 'exported' attribute;
  5128 
  5129 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5130 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5131 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5132 
  5133 * Pure: method 'atomize' presents local goal premises as object-level
  5134 statements (atomic meta-level propositions); setup controlled via
  5135 rewrite rules declarations of 'atomize' attribute; example
  5136 application: 'induct' method with proper rule statements in improper
  5137 proof *scripts*;
  5138 
  5139 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5140 now consider the syntactic context of assumptions, giving a better
  5141 chance to get type-inference of the arguments right (this is
  5142 especially important for locales);
  5143 
  5144 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5145 mode;
  5146 
  5147 * Pure/obtain: the formal conclusion "thesis", being marked as
  5148 ``internal'', may no longer be reference directly in the text;
  5149 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5150 situations;
  5151 
  5152 * Pure: generic 'sym' attribute which declares a rule both as pure
  5153 'elim?' and for the 'symmetric' operation;
  5154 
  5155 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5156 text; the fixed correlation with particular command syntax has been
  5157 discontinued;
  5158 
  5159 * Pure: new method 'rules' is particularly well-suited for proof
  5160 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5161 but often produces more compact proof terms with less detours;
  5162 
  5163 * Pure/Provers/classical: simplified integration with pure rule
  5164 attributes and methods; the classical "intro?/elim?/dest?"
  5165 declarations coincide with the pure ones; the "rule" method no longer
  5166 includes classically swapped intros; "intro" and "elim" methods no
  5167 longer pick rules from the context; also got rid of ML declarations
  5168 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5169 INCOMPATIBILITY;
  5170 
  5171 * Provers/classical: attribute 'swapped' produces classical inversions
  5172 of introduction rules;
  5173 
  5174 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5175 rules instead of full simplifier context; 'iff' attribute handles
  5176 conditional rules;
  5177 
  5178 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5179 
  5180 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5181 "(permissive)" option to recover old behavior;
  5182 
  5183 * HOL: 'inductive' no longer features separate (collective) attributes
  5184 for 'intros' (was found too confusing);
  5185 
  5186 * HOL: properly declared induction rules less_induct and
  5187 wf_induct_rule;
  5188 
  5189 
  5190 *** HOL ***
  5191 
  5192 * HOL: moved over to sane numeral syntax; the new policy is as
  5193 follows:
  5194 
  5195   - 0 and 1 are polymorphic constants, which are defined on any
  5196   numeric type (nat, int, real etc.);
  5197 
  5198   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5199   binary representation internally;
  5200 
  5201   - type nat has special constructor Suc, and generally prefers Suc 0
  5202   over 1::nat and Suc (Suc 0) over 2::nat;
  5203 
  5204 This change may cause significant problems of INCOMPATIBILITY; here
  5205 are some hints on converting existing sources:
  5206 
  5207   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5208   entities, so expressions involving "-" (unary or binary minus) need
  5209   to be spaced properly;
  5210 
  5211   - existing occurrences of "1" may need to be constraint "1::nat" or
  5212   even replaced by Suc 0; similar for old "2";
  5213 
  5214   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5215 
  5216   - remove all special provisions on numerals in proofs;
  5217 
  5218 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5219 representation (depends on bin_arith_simps in the default context);
  5220 
  5221 * HOL: symbolic syntax for x^2 (numeral 2);
  5222 
  5223 * HOL: the class of all HOL types is now called "type" rather than
  5224 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5225 in axclass/classes, instance/arities, and (usually rare) occurrences
  5226 in typings (of consts etc.); internally the class is called
  5227 "HOL.type", ML programs should refer to HOLogic.typeS;
  5228 
  5229 * HOL/record package improvements:
  5230   - new derived operations "fields" to build a partial record section,
  5231     "extend" to promote a fixed record to a record scheme, and
  5232     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5233     declared as simp by default;
  5234   - shared operations ("more", "fields", etc.) now need to be always
  5235     qualified) --- potential INCOMPATIBILITY;
  5236   - removed "make_scheme" operations (use "make" with "extend") --
  5237     INCOMPATIBILITY;
  5238   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5239   - provides cases/induct rules for use with corresponding Isar
  5240     methods (for concrete records, record schemes, concrete more
  5241     parts, and schematic more parts -- in that order);
  5242   - internal definitions directly based on a light-weight abstract
  5243     theory of product types over typedef rather than datatype;
  5244 
  5245 * HOL: generic code generator for generating executable ML code from
  5246 specifications; specific support for HOL constructs such as inductive
  5247 datatypes and sets, as well as recursive functions; can be invoked
  5248 via 'generate_code' theory section;
  5249 
  5250 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5251 
  5252 * HOL: consolidated and renamed several theories.  In particular:
  5253         Ord.thy has been absorbed into HOL.thy
  5254         String.thy has been absorbed into List.thy
  5255 
  5256 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5257 (beware of argument permutation!);
  5258 
  5259 * HOL: linorder_less_split superseded by linorder_cases;
  5260 
  5261 * HOL/List: "nodups" renamed to "distinct";
  5262 
  5263 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5264 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5265   - Ex_def has changed, now need to use some_eq_ex
  5266 
  5267 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5268 in this (rare) case use:
  5269 
  5270   delSWrapper "split_all_tac"
  5271   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5272 
  5273 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5274 MAY FAIL;
  5275 
  5276 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5277 Isabelle's type classes, ^ on functions and relations has too general
  5278 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5279 necessary to attach explicit type constraints;
  5280 
  5281 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5282 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5283 renamed accordingly (eg "compI" -> "rel_compI").
  5284 
  5285 * HOL: syntax translations now work properly with numerals and records
  5286 expressions;
  5287 
  5288 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5289 of "lam" -- INCOMPATIBILITY;
  5290 
  5291 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5292 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5293 renamed "Product_Type.unit";
  5294 
  5295 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5296 
  5297 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5298 the "cases" method);
  5299 
  5300 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5301 Florian Kammller);
  5302 
  5303 * HOL/IMP: updated and converted to new-style theory format; several
  5304 parts turned into readable document, with proper Isar proof texts and
  5305 some explanations (by Gerwin Klein);
  5306 
  5307 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5308 
  5309 * HOL-Hyperreal is now a logic image;
  5310 
  5311 
  5312 *** HOLCF ***
  5313 
  5314 * Isar: consts/constdefs supports mixfix syntax for continuous
  5315 operations;
  5316 
  5317 * Isar: domain package adapted to new-style theory format, e.g. see
  5318 HOLCF/ex/Dnat.thy;
  5319 
  5320 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5321 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5322 lift.induct_tac, always use UU instead of Undef;
  5323 
  5324 * HOLCF/IMP: updated and converted to new-style theory;
  5325 
  5326 
  5327 *** ZF ***
  5328 
  5329 * Isar: proper integration of logic-specific tools and packages,
  5330 including theory commands '(co)inductive', '(co)datatype',
  5331 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5332 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5333 
  5334 * theory Main no longer includes AC; for the Axiom of Choice, base
  5335 your theory on Main_ZFC;
  5336 
  5337 * the integer library now covers quotients and remainders, with many
  5338 laws relating division to addition, multiplication, etc.;
  5339 
  5340 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5341 typeless version of the formalism;
  5342 
  5343 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5344 format;
  5345 
  5346 * ZF/Induct: new directory for examples of inductive definitions,
  5347 including theory Multiset for multiset orderings; converted to
  5348 new-style theory format;
  5349 
  5350 * ZF: many new theorems about lists, ordinals, etc.;
  5351 
  5352 
  5353 *** General ***
  5354 
  5355 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5356 variable proof controls level of detail: 0 = no proofs (only oracle
  5357 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5358 also ref manual for further ML interfaces;
  5359 
  5360 * Pure/axclass: removed obsolete ML interface
  5361 goal_subclass/goal_arity;
  5362 
  5363 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5364 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5365 separate tokens, so expressions involving minus need to be spaced
  5366 properly;
  5367 
  5368 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5369 rather than "infixl" or "infixr";
  5370 
  5371 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5372 sort constraint specifications in type inference; e.g. "x::_::foo"
  5373 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5374 type variable);
  5375 
  5376 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5377 control output of nested => (types); the default behavior is
  5378 "type_brackets";
  5379 
  5380 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5381 tokens into AST constants;
  5382 
  5383 * Pure/syntax: prefer later declarations of translations and print
  5384 translation functions; potential INCOMPATIBILITY: need to reverse
  5385 multiple declarations for same syntax element constant;
  5386 
  5387 * Pure/show_hyps reset by default (in accordance to existing Isar
  5388 practice);
  5389 
  5390 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5391 addSafter;
  5392 
  5393 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5394 as well;
  5395 
  5396 * system: tested support for MacOS X; should be able to get Isabelle +
  5397 Proof General to work in a plain Terminal after installing Poly/ML
  5398 (e.g. from the Isabelle distribution area) and GNU bash alone
  5399 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5400 support requires further installations, e.g. from
  5401 http://fink.sourceforge.net/);
  5402 
  5403 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5404 
  5405 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5406 of 40 MB), cf. ML_OPTIONS;
  5407 
  5408 * system: Proof General keywords specification is now part of the
  5409 Isabelle distribution (see etc/isar-keywords.el);
  5410 
  5411 * system: support for persistent Proof General sessions (refrain from
  5412 outdating all loaded theories on startup); user may create writable
  5413 logic images like this: ``isabelle -q HOL Test'';
  5414 
  5415 * system: smart selection of Isabelle process versus Isabelle
  5416 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5417 run both "isabelle" and "Isabelle" even if file names are badly
  5418 damaged (executable inspects the case of the first letter of its own
  5419 name); added separate "isabelle-process" and "isabelle-interface";
  5420 
  5421 * system: refrain from any attempt at filtering input streams; no
  5422 longer support ``8bit'' encoding of old isabelle font, instead proper
  5423 iso-latin characters may now be used; the related isatools
  5424 "symbolinput" and "nonascii" have disappeared as well;
  5425 
  5426 * system: removed old "xterm" interface (the print modes "xterm" and
  5427 "xterm_color" are still available for direct use in a suitable
  5428 terminal);
  5429 
  5430 
  5431 
  5432 New in Isabelle99-2 (February 2001)
  5433 -----------------------------------
  5434 
  5435 *** Overview of INCOMPATIBILITIES ***
  5436 
  5437 * HOL: please note that theories in the Library and elsewhere often use the
  5438 new-style (Isar) format; to refer to their theorems in an ML script you must
  5439 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5440 
  5441 * HOL: inductive package no longer splits induction rule aggressively,
  5442 but only as far as specified by the introductions given; the old
  5443 format may be recovered via ML function complete_split_rule or attribute
  5444 'split_rule (complete)';
  5445 
  5446 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5447 gfp_Tarski to gfp_unfold;
  5448 
  5449 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5450 
  5451 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5452 relation); infix "^^" has been renamed "``"; infix "``" has been
  5453 renamed "`"; "univalent" has been renamed "single_valued";
  5454 
  5455 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5456 operation;
  5457 
  5458 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5459 
  5460 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5461 
  5462 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5463 consequence, it is no longer monotonic wrt. the local goal context
  5464 (which is now passed through the inductive cases);
  5465 
  5466 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5467 \<gg> to \<ggreater>;
  5468 
  5469 
  5470 *** Document preparation ***
  5471 
  5472 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5473 available: are "it" for near math-mode best-style output, "sl" for
  5474 slanted text style, and "tt" for plain type-writer; if no
  5475 \isabellestyle command is given, output is according to slanted
  5476 type-writer);
  5477 
  5478 * support sub/super scripts (for single symbols only), input syntax is
  5479 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5480 
  5481 * some more standard symbols; see Appendix A of the system manual for
  5482 the complete list of symbols defined in isabellesym.sty;
  5483 
  5484 * improved isabelle style files; more abstract symbol implementation
  5485 (should now use \isamath{...} and \isatext{...} in custom symbol
  5486 definitions);
  5487 
  5488 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5489 state; Note that presentation of goal states does not conform to
  5490 actual human-readable proof documents.  Please do not include goal
  5491 states into document output unless you really know what you are doing!
  5492 
  5493 * proper indentation of antiquoted output with proportional LaTeX
  5494 fonts;
  5495 
  5496 * no_document ML operator temporarily disables LaTeX document
  5497 generation;
  5498 
  5499 * isatool unsymbolize tunes sources for plain ASCII communication;
  5500 
  5501 
  5502 *** Isar ***
  5503 
  5504 * Pure: Isar now suffers initial goal statements to contain unbound
  5505 schematic variables (this does not conform to actual readable proof
  5506 documents, due to unpredictable outcome and non-compositional proof
  5507 checking); users who know what they are doing may use schematic goals
  5508 for Prolog-style synthesis of proven results;
  5509 
  5510 * Pure: assumption method (an implicit finishing) now handles actual
  5511 rules as well;
  5512 
  5513 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5514 initial goal, declare "that" only as Pure intro (only for single
  5515 steps); the "that" rule assumption may now be involved in implicit
  5516 finishing, thus ".." becomes a feasible for trivial obtains;
  5517 
  5518 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5519 instance proofs may be performed by "..";
  5520 
  5521 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5522 statements as well;
  5523 
  5524 * Pure: more robust selection of calculational rules;
  5525 
  5526 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5527 rule (as well as the assumption rule);
  5528 
  5529 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5530 lemmas, using the graph browser tool;
  5531 
  5532 * Pure: predict failure of "show" in interactive mode;
  5533 
  5534 * Pure: 'thms_containing' now takes actual terms as arguments;
  5535 
  5536 * HOL: improved method 'induct' --- now handles non-atomic goals
  5537 (potential INCOMPATIBILITY); tuned error handling;
  5538 
  5539 * HOL: cases and induct rules now provide explicit hints about the
  5540 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5541 any remaining facts are inserted into the goal verbatim;
  5542 
  5543 * HOL: local contexts (aka cases) may now contain term bindings as
  5544 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5545 the result to be shown in each case;
  5546 
  5547 * HOL: added 'recdef_tc' command;
  5548 
  5549 * isatool convert assists in eliminating legacy ML scripts;
  5550 
  5551 
  5552 *** HOL ***
  5553 
  5554 * HOL/Library: a collection of generic theories to be used together
  5555 with main HOL; the theory loader path already includes this directory
  5556 by default; the following existing theories have been moved here:
  5557 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5558 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5559 
  5560 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5561 modelling and verification task performed in Isabelle/HOL +
  5562 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5563 
  5564 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5565 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5566 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5567 'domain', this makes the theory consistent with mathematical
  5568 literature;
  5569 
  5570 * HOL basics: added overloaded operations "inverse" and "divide"
  5571 (infix "/"), syntax for generic "abs" operation, generic summation
  5572 operator \<Sum>;
  5573 
  5574 * HOL/typedef: simplified package, provide more useful rules (see also
  5575 HOL/subset.thy);
  5576 
  5577 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5578 now expressed as a proper nested rule (old-style tactic scripts may
  5579 require atomize_strip_tac to cope with non-atomic premises);
  5580 
  5581 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5582 to "split_conv" (old name still available for compatibility);
  5583 
  5584 * HOL: improved concrete syntax for strings (e.g. allows translation
  5585 rules with string literals);
  5586 
  5587 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5588  and Fleuriot's mechanization of analysis, including the transcendental
  5589  functions for the reals;
  5590 
  5591 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5592 
  5593 
  5594 *** CTT ***
  5595 
  5596 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5597 "lam" is displayed as TWO lambda-symbols
  5598 
  5599 * CTT: theory Main now available, containing everything (that is, Bool
  5600 and Arith);
  5601 
  5602 
  5603 *** General ***
  5604 
  5605 * Pure: the Simplifier has been implemented properly as a derived rule
  5606 outside of the actual kernel (at last!); the overall performance
  5607 penalty in practical applications is about 50%, while reliability of
  5608 the Isabelle inference kernel has been greatly improved;
  5609 
  5610 * print modes "brackets" and "no_brackets" control output of nested =>
  5611 (types) and ==> (props); the default behaviour is "brackets";
  5612 
  5613 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5614 as assumptions as well;
  5615 
  5616 * system: support Poly/ML 4.0;
  5617 
  5618 * system: isatool install handles KDE version 1 or 2;
  5619 
  5620 
  5621 
  5622 New in Isabelle99-1 (October 2000)
  5623 ----------------------------------
  5624 
  5625 *** Overview of INCOMPATIBILITIES ***
  5626 
  5627 * HOL: simplification of natural numbers is much changed; to partly
  5628 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5629 issue the following ML commands:
  5630 
  5631   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5632   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5633 
  5634 * HOL: simplification no longer dives into case-expressions; this is
  5635 controlled by "t.weak_case_cong" for each datatype t;
  5636 
  5637 * HOL: nat_less_induct renamed to less_induct;
  5638 
  5639 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5640 fixsome to patch .thy and .ML sources automatically;
  5641 
  5642   select_equality  -> some_equality
  5643   select_eq_Ex     -> some_eq_ex
  5644   selectI2EX       -> someI2_ex
  5645   selectI2         -> someI2
  5646   selectI          -> someI
  5647   select1_equality -> some1_equality
  5648   Eps_sym_eq       -> some_sym_eq_trivial
  5649   Eps_eq           -> some_eq_trivial
  5650 
  5651 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5652 
  5653 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5654 instead);
  5655 
  5656 * HOL: the recursion equations generated by 'recdef' are now called
  5657 f.simps instead of f.rules;
  5658 
  5659 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5660 
  5661 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5662 sometimes be needed;
  5663 
  5664 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5665 
  5666 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5667 
  5668 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5669 product is now "<*>" instead of "Times"; the lexicographic product is
  5670 now "<*lex*>" instead of "**";
  5671 
  5672 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5673 of main HOL, but was unused); better use HOL's datatype package;
  5674 
  5675 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5676 the old syntax may be recovered as follows:
  5677 
  5678   syntax (symbols)
  5679     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5680       (infixl "\\<oplus>" 100)
  5681 
  5682 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5683 
  5684 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5685 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5686 internally;
  5687 
  5688 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5689 changed from A/r to A//r;
  5690 
  5691 * ZF: new treatment of arithmetic (nat & int) may break some old
  5692 proofs;
  5693 
  5694 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5695 rulify -> rule_format, elimify -> elim_format, ...);
  5696 
  5697 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5698 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5699 should have to change intro!! to intro? only); replaced "delrule" by
  5700 "rule del";
  5701 
  5702 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5703 
  5704 * Provers: strengthened force_tac by using new first_best_tac;
  5705 
  5706 * LaTeX document preparation: several changes of isabelle.sty (see
  5707 lib/texinputs);
  5708 
  5709 
  5710 *** Document preparation ***
  5711 
  5712 * formal comments (text blocks etc.) in new-style theories may now
  5713 contain antiquotations of thm/prop/term/typ/text to be presented
  5714 according to latex print mode; concrete syntax is like this:
  5715 @{term[show_types] "f(x) = a + x"};
  5716 
  5717 * isatool mkdir provides easy setup of Isabelle session directories,
  5718 including proper document sources;
  5719 
  5720 * generated LaTeX sources are now deleted after successful run
  5721 (isatool document -c); may retain a copy somewhere else via -D option
  5722 of isatool usedir;
  5723 
  5724 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5725 style files, achieving self-contained LaTeX sources and simplifying
  5726 LaTeX debugging;
  5727 
  5728 * old-style theories now produce (crude) LaTeX output as well;
  5729 
  5730 * browser info session directories are now self-contained (may be put
  5731 on WWW server seperately); improved graphs of nested sessions; removed
  5732 graph for 'all sessions';
  5733 
  5734 * several improvements in isabelle style files; \isabellestyle{it}
  5735 produces fake math mode output; \isamarkupheader is now \section by
  5736 default; see lib/texinputs/isabelle.sty etc.;
  5737 
  5738 
  5739 *** Isar ***
  5740 
  5741 * Isar/Pure: local results and corresponding term bindings are now
  5742 subject to Hindley-Milner polymorphism (similar to ML); this
  5743 accommodates incremental type-inference very nicely;
  5744 
  5745 * Isar/Pure: new derived language element 'obtain' supports
  5746 generalized existence reasoning;
  5747 
  5748 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5749 support accumulation of results, without applying any rules yet;
  5750 useful to collect intermediate results without explicit name
  5751 references, and for use with transitivity rules with more than 2
  5752 premises;
  5753 
  5754 * Isar/Pure: scalable support for case-analysis type proofs: new
  5755 'case' language element refers to local contexts symbolically, as
  5756 produced by certain proof methods; internally, case names are attached
  5757 to theorems as "tags";
  5758 
  5759 * Isar/Pure: theory command 'hide' removes declarations from
  5760 class/type/const name spaces;
  5761 
  5762 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5763 indicate potential overloading;
  5764 
  5765 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5766 
  5767 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5768 "{a,b,c}" instead of {a,b,c};
  5769 
  5770 * Isar/Pure now provides its own version of intro/elim/dest
  5771 attributes; useful for building new logics, but beware of confusion
  5772 with the version in Provers/classical;
  5773 
  5774 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5775 case name 'antecedent';
  5776 
  5777 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5778 to the current context is now done automatically);
  5779 
  5780 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5781 for definining proof methods in ML;
  5782 
  5783 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5784 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5785 most cases, one should have to change intro!! to intro? only);
  5786 replaced "delrule" by "rule del";
  5787 
  5788 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5789 'symmetric' attribute (the latter supercedes [RS sym]);
  5790 
  5791 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5792 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5793 well (including splits);
  5794 
  5795 * Isar/Provers: Simplifier and Classical methods now support all kind
  5796 of modifiers used in the past, including 'cong', 'iff', etc.
  5797 
  5798 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5799 of Simplifier and Classical reasoner);
  5800 
  5801 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5802 now support named cases; major packages (inductive, datatype, primrec,
  5803 recdef) support case names and properly name parameters;
  5804 
  5805 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5806 monotonicity conditions are extracted to be proven at end of
  5807 calculations;
  5808 
  5809 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5810 method anyway;
  5811 
  5812 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5813 split_if split_if_asm; datatype package provides theorems foo.splits =
  5814 foo.split foo.split_asm for each datatype;
  5815 
  5816 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5817 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5818 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5819 use "(cases (simplified))" method in proper proof texts);
  5820 
  5821 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5822 
  5823 * Isar: names of theorems etc. may be natural numbers as well;
  5824 
  5825 * Isar: 'pr' command: optional arguments for goals_limit and
  5826 ProofContext.prems_limit; no longer prints theory contexts, but only
  5827 proof states;
  5828 
  5829 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5830 additional print modes to be specified; e.g. "pr(latex)" will print
  5831 proof state according to the Isabelle LaTeX style;
  5832 
  5833 * Isar: improved support for emulating tactic scripts, including proof
  5834 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5835 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5836 (for HOL datatypes);
  5837 
  5838 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5839 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5840 'proof method scripts' have to be in depth-first order;
  5841 
  5842 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5843 
  5844 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5845 should instead use individual commands for printing items
  5846 (print_commands, print_methods etc.);
  5847 
  5848 * Isar: added 'nothing' --- the empty list of theorems;
  5849 
  5850 
  5851 *** HOL ***
  5852 
  5853 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5854 corresponding virtual machine and a specification of its bytecode
  5855 verifier and a lightweight bytecode verifier, including proofs of
  5856 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5857 Cornelia Pusch (see also the homepage of project Bali at
  5858 http://isabelle.in.tum.de/Bali/);
  5859 
  5860 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5861 Clemens Ballarin;
  5862 
  5863 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5864 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5865 Rasmussen;
  5866 
  5867 * HOL/Lattice: fundamental concepts of lattice theory and order
  5868 structures, including duals, properties of bounds versus algebraic
  5869 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5870 Theorem for complete lattices etc.; may also serve as a demonstration
  5871 for abstract algebraic reasoning using axiomatic type classes, and
  5872 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5873 
  5874 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5875 von Oheimb;
  5876 
  5877 * HOL/IMPP: extension of IMP with local variables and mutually
  5878 recursive procedures, by David von Oheimb;
  5879 
  5880 * HOL/Lambda: converted into new-style theory and document;
  5881 
  5882 * HOL/ex/Multiquote: example of multiple nested quotations and
  5883 anti-quotations -- basically a generalized version of de-Bruijn
  5884 representation; very useful in avoiding lifting of operations;
  5885 
  5886 * HOL/record: added general record equality rule to simpset; fixed
  5887 select-update simplification procedure to handle extended records as
  5888 well; admit "r" as field name;
  5889 
  5890 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5891 other numeric types and also as the identity of groups, rings, etc.;
  5892 
  5893 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5894 Types nat and int belong to this axclass;
  5895 
  5896 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5897    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5898    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5899   two terms #m*u and #n*u are replaced by #(m+n)*u
  5900     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5901   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5902     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5903 
  5904 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5905 powerful prover for predicate logic but knows nothing of clasets; see
  5906 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5907 
  5908 * HOL: new version of "case_tac" subsumes both boolean case split and
  5909 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5910 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5911 
  5912 * HOL: simplification no longer dives into case-expressions: only the
  5913 selector expression is simplified, but not the remaining arms; to
  5914 enable full simplification of case-expressions for datatype t, you may
  5915 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5916 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5917 
  5918 * HOL/recdef: the recursion equations generated by 'recdef' for
  5919 function 'f' are now called f.simps instead of f.rules; if all
  5920 termination conditions are proved automatically, these simplification
  5921 rules are added to the simpset, as in primrec; rules may be named
  5922 individually as well, resulting in a separate list of theorems for
  5923 each equation;
  5924 
  5925 * HOL/While is a new theory that provides a while-combinator. It
  5926 permits the definition of tail-recursive functions without the
  5927 provision of a termination measure. The latter is necessary once the
  5928 invariant proof rule for while is applied.
  5929 
  5930 * HOL: new (overloaded) notation for the set of elements below/above
  5931 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5932 
  5933 * HOL: theorems impI, allI, ballI bound as "strip";
  5934 
  5935 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5936 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5937 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5938 
  5939 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5940 
  5941 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5942 main HOL, but was unused);
  5943 
  5944 * HOL: fewer consts declared as global (e.g. have to refer to
  5945 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5946 
  5947 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5948 in case of overlap with user translations (e.g. judgements over
  5949 tuples); (note that the underlying logical represenation is still
  5950 bogus);
  5951 
  5952 
  5953 *** ZF ***
  5954 
  5955 * ZF: simplification automatically cancels common terms in arithmetic
  5956 expressions over nat and int;
  5957 
  5958 * ZF: new treatment of nat to minimize type-checking: all operators
  5959 coerce their operands to a natural number using the function natify,
  5960 making the algebraic laws unconditional;
  5961 
  5962 * ZF: as above, for int: operators coerce their operands to an integer
  5963 using the function intify;
  5964 
  5965 * ZF: the integer library now contains many of the usual laws for the
  5966 orderings, including $<=, and monotonicity laws for $+ and $*;
  5967 
  5968 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5969 simplification;
  5970 
  5971 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5972 to the simplifier and classical reasoner simultaneously;
  5973 
  5974 
  5975 *** General ***
  5976 
  5977 * Provers: blast_tac now handles actual object-logic rules as
  5978 assumptions; note that auto_tac uses blast_tac internally as well;
  5979 
  5980 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5981 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5982 
  5983 * Provers: delrules now handles destruct rules as well (no longer need
  5984 explicit make_elim);
  5985 
  5986 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5987   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5988 use instead the strong form,
  5989   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5990 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5991 from destruct-rules;
  5992 
  5993 * Provers: Simplifier.easy_setup provides a fast path to basic
  5994 Simplifier setup for new object-logics;
  5995 
  5996 * Pure: AST translation rules no longer require constant head on LHS;
  5997 
  5998 * Pure: improved name spaces: ambiguous output is qualified; support
  5999 for hiding of names;
  6000 
  6001 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6002 XSYMBOL_HOME; no longer need to do manual configuration in most
  6003 situations;
  6004 
  6005 * system: compression of ML heaps images may now be controlled via -c
  6006 option of isabelle and isatool usedir (currently only observed by
  6007 Poly/ML);
  6008 
  6009 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6010 useful for remote X11);
  6011 
  6012 * system: provide TAGS file for Isabelle sources;
  6013 
  6014 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6015 order;
  6016 
  6017 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6018 timing flag supersedes proof_timing and Toplevel.trace;
  6019 
  6020 * ML: new combinators |>> and |>>> for incremental transformations
  6021 with secondary results (e.g. certain theory extensions):
  6022 
  6023 * ML: PureThy.add_defs gets additional argument to indicate potential
  6024 overloading (usually false);
  6025 
  6026 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6027 results;
  6028 
  6029 
  6030 
  6031 New in Isabelle99 (October 1999)
  6032 --------------------------------
  6033 
  6034 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6035 
  6036 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6037 are no longer simplified.  (This allows the simplifier to unfold recursive
  6038 functional programs.)  To restore the old behaviour, declare
  6039 
  6040     Delcongs [if_weak_cong];
  6041 
  6042 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6043 complement;
  6044 
  6045 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6046 
  6047 * HOL/datatype: mutual_induct_tac no longer exists --
  6048   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6049 
  6050 * HOL/typedef: fixed type inference for representing set; type
  6051 arguments now have to occur explicitly on the rhs as type constraints;
  6052 
  6053 * ZF: The con_defs part of an inductive definition may no longer refer
  6054 to constants declared in the same theory;
  6055 
  6056 * HOL, ZF: the function mk_cases, generated by the inductive
  6057 definition package, has lost an argument.  To simplify its result, it
  6058 uses the default simpset instead of a supplied list of theorems.
  6059 
  6060 * HOL/List: the constructors of type list are now Nil and Cons;
  6061 
  6062 * Simplifier: the type of the infix ML functions
  6063         setSSolver addSSolver setSolver addSolver
  6064 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6065 for packaging solvers. A solver is created via
  6066         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6067 where the string argument is only a comment.
  6068 
  6069 
  6070 *** Proof tools ***
  6071 
  6072 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6073 decision procedure for linear arithmetic. Currently it is used for
  6074 types `nat', `int', and `real' in HOL (see below); it can, should and
  6075 will be instantiated for other types and logics as well.
  6076 
  6077 * The simplifier now accepts rewrite rules with flexible heads, eg
  6078      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6079   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6080   matching.
  6081 
  6082 
  6083 *** General ***
  6084 
  6085 * New Isabelle/Isar subsystem provides an alternative to traditional
  6086 tactical theorem proving; together with the ProofGeneral/isar user
  6087 interface it offers an interactive environment for developing human
  6088 readable proof documents (Isar == Intelligible semi-automated
  6089 reasoning); for further information see isatool doc isar-ref,
  6090 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6091 
  6092 * improved and simplified presentation of theories: better HTML markup
  6093 (including colors), graph views in several sizes; isatool usedir now
  6094 provides a proper interface for user theories (via -P option); actual
  6095 document preparation based on (PDF)LaTeX is available as well (for
  6096 new-style theories only); see isatool doc system for more information;
  6097 
  6098 * native support for Proof General, both for classic Isabelle and
  6099 Isabelle/Isar;
  6100 
  6101 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  6102 using the graph browser tool;
  6103 
  6104 * Isabelle manuals now also available as PDF;
  6105 
  6106 * theory loader rewritten from scratch (may not be fully
  6107 bug-compatible); old loadpath variable has been replaced by show_path,
  6108 add_path, del_path, reset_path functions; new operations such as
  6109 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6110 isatool doc ref);
  6111 
  6112 * improved isatool install: option -k creates KDE application icon,
  6113 option -p DIR installs standalone binaries;
  6114 
  6115 * added ML_PLATFORM setting (useful for cross-platform installations);
  6116 more robust handling of platform specific ML images for SML/NJ;
  6117 
  6118 * the settings environment is now statically scoped, i.e. it is never
  6119 created again in sub-processes invoked from isabelle, isatool, or
  6120 Isabelle;
  6121 
  6122 * path element specification '~~' refers to '$ISABELLE_HOME';
  6123 
  6124 * in locales, the "assumes" and "defines" parts may be omitted if
  6125 empty;
  6126 
  6127 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  6128 long arrows);
  6129 
  6130 * new print_mode "HTML";
  6131 
  6132 * new flag show_tags controls display of tags of theorems (which are
  6133 basically just comments that may be attached by some tools);
  6134 
  6135 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  6136 mode and goal output format:
  6137 
  6138 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  6139 244c244
  6140 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  6141 ---
  6142 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  6143 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  6144 181c181
  6145 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  6146 ---
  6147 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  6148 
  6149 * function bind_thms stores lists of theorems (cf. bind_thm);
  6150 
  6151 * new shorthand tactics ftac, eatac, datac, fatac;
  6152 
  6153 * qed (and friends) now accept "" as result name; in that case the
  6154 theorem is not stored, but proper checks and presentation of the
  6155 result still apply;
  6156 
  6157 * theorem database now also indexes constants "Trueprop", "all",
  6158 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  6159 
  6160 
  6161 *** HOL ***
  6162 
  6163 ** HOL arithmetic **
  6164 
  6165 * There are now decision procedures for linear arithmetic over nat and
  6166 int:
  6167 
  6168 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  6169 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  6170 are treated as atomic; subformulae not involving type `nat' or `int'
  6171 are ignored; quantified subformulae are ignored unless they are
  6172 positive universal or negative existential. The tactic has to be
  6173 invoked by hand and can be a little bit slow. In particular, the
  6174 running time is exponential in the number of occurrences of `min' and
  6175 `max', and `-' on `nat'.
  6176 
  6177 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  6178 (negated) (in)equalities among the premises and the conclusion into
  6179 account (i.e. no compound formulae) and does not know about `min' and
  6180 `max', and `-' on `nat'. It is fast and is used automatically by the
  6181 simplifier.
  6182 
  6183 NB: At the moment, these decision procedures do not cope with mixed
  6184 nat/int formulae where the two parts interact, such as `m < n ==>
  6185 int(m) < int(n)'.
  6186 
  6187 * HOL/Numeral provides a generic theory of numerals (encoded
  6188 efficiently as bit strings); setup for types nat/int/real is in place;
  6189 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  6190 int, existing theories and proof scripts may require a few additional
  6191 type constraints;
  6192 
  6193 * integer division and remainder can now be performed on constant
  6194 arguments;
  6195 
  6196 * many properties of integer multiplication, division and remainder
  6197 are now available;
  6198 
  6199 * An interface to the Stanford Validity Checker (SVC) is available through the
  6200 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  6201 are proved automatically.  SVC must be installed separately, and its results
  6202 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  6203 invocation of the underlying oracle).  For SVC see
  6204   http://verify.stanford.edu/SVC
  6205 
  6206 * IsaMakefile: the HOL-Real target now builds an actual image;
  6207 
  6208 
  6209 ** HOL misc **
  6210 
  6211 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  6212 (in Isabelle/Isar) -- by Gertrud Bauer;
  6213 
  6214 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  6215 analysis for assembly languages with subtypes;
  6216 
  6217 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  6218 -- avoids syntactic ambiguities and treats state, transition, and
  6219 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  6220 changed syntax and (many) tactics;
  6221 
  6222 * HOL/inductive: Now also handles more general introduction rules such
  6223   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  6224   theorems are now maintained within the theory (maintained via the
  6225   "mono" attribute);
  6226 
  6227 * HOL/datatype: Now also handles arbitrarily branching datatypes