NEWS
author wenzelm
Thu May 27 18:10:37 2010 +0200 (2010-05-27)
changeset 37146 f652333bbf8e
parent 37145 01aa36932739
child 37158 c96e119b7fe9
permissions -rw-r--r--
renamed structure PrintMode to Print_Mode, 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   PrintMode     ~>  Print_Mode
   507 
   508 Note that "open Legacy" simplifies porting of sources, but forgetting
   509 to remove it again will complicate porting again in the future.
   510 
   511 * Most operations that refer to a global context are named
   512 accordingly, e.g. Simplifier.global_context or
   513 ProofContext.init_global.  There are some situations where a global
   514 context actually works, but under normal circumstances one needs to
   515 pass the proper local context through the code!
   516 
   517 * Discontinued old TheoryDataFun with its copy/init operation -- data
   518 needs to be pure.  Functor Theory_Data_PP retains the traditional
   519 Pretty.pp argument to merge, which is absent in the standard
   520 Theory_Data version.
   521 
   522 * Antiquotations for basic formal entities:
   523 
   524     @{class NAME}         -- type class
   525     @{class_syntax NAME}  -- syntax representation of the above
   526 
   527     @{type_name NAME}     -- logical type
   528     @{type_abbrev NAME}   -- type abbreviation
   529     @{nonterminal NAME}   -- type of concrete syntactic category
   530     @{type_syntax NAME}   -- syntax representation of any of the above
   531 
   532     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   533     @{const_abbrev NAME}  -- abbreviated constant
   534     @{const_syntax NAME}  -- syntax representation of any of the above
   535 
   536 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   537 syntax constant (cf. 'syntax' command).
   538 
   539 * Antiquotation @{make_string} inlines a function to print arbitrary
   540 values similar to the ML toplevel.  The result is compiler dependent
   541 and may fall back on "?" in certain situations.
   542 
   543 * Sorts.certify_sort and derived "cert" operations for types and terms
   544 no longer minimize sorts.  Thus certification at the boundary of the
   545 inference kernel becomes invariant under addition of class relations,
   546 which is an important monotonicity principle.  Sorts are now minimized
   547 in the syntax layer only, at the boundary between the end-user and the
   548 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   549 explicitly in rare situations.
   550 
   551 * Renamed old-style Drule.standard to Drule.export_without_context, to
   552 emphasize that this is in no way a standard operation.
   553 INCOMPATIBILITY.
   554 
   555 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   556 usual for resolution.  Rare INCOMPATIBILITY.
   557 
   558 * Renamed varify/unvarify operations to varify_global/unvarify_global
   559 to emphasize that these only work in a global situation (which is
   560 quite rare).
   561 
   562 * Configuration options now admit dynamic default values, depending on
   563 the context or even global references.
   564 
   565 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   566 uses an efficient external library if available (for Poly/ML).
   567 
   568 * Curried take and drop in library.ML; negative length is interpreted
   569 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   570 
   571 
   572 *** System ***
   573 
   574 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   575 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   576 proof terms are enabled unconditionally in the new HOL-Proofs image.
   577 
   578 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   579 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   580 respectively.
   581 
   582 * Old lib/scripts/polyml-platform is superseded by the
   583 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   584 variant, even on a 64 bit machine.  The following example setting
   585 prefers 64 bit if available:
   586 
   587   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   588 
   589 
   590 
   591 New in Isabelle2009-1 (December 2009)
   592 -------------------------------------
   593 
   594 *** General ***
   595 
   596 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   597 one backslash should be used, even in ML sources.
   598 
   599 
   600 *** Pure ***
   601 
   602 * Locale interpretation propagates mixins along the locale hierarchy.
   603 The currently only available mixins are the equations used to map
   604 local definitions to terms of the target domain of an interpretation.
   605 
   606 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   607 loc" to print all interpretations of locale "loc" in the theory.
   608 Interpretations in proofs are not shown.
   609 
   610 * Thoroughly revised locales tutorial.  New section on conditional
   611 interpretation.
   612 
   613 * On instantiation of classes, remaining undefined class parameters
   614 are formally declared.  INCOMPATIBILITY.
   615 
   616 
   617 *** Document preparation ***
   618 
   619 * New generalized style concept for printing terms: @{foo (style) ...}
   620 instead of @{foo_style style ...}  (old form is still retained for
   621 backward compatibility).  Styles can be also applied for
   622 antiquotations prop, term_type and typeof.
   623 
   624 
   625 *** HOL ***
   626 
   627 * New proof method "smt" for a combination of first-order logic with
   628 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   629 fixed-size bitvectors; there is also basic support for higher-order
   630 features (esp. lambda abstractions).  It is an incomplete decision
   631 procedure based on external SMT solvers using the oracle mechanism;
   632 for the SMT solver Z3, this method is proof-producing.  Certificates
   633 are provided to avoid calling the external solvers solely for
   634 re-checking proofs.  Due to a remote SMT service there is no need for
   635 installing SMT solvers locally.  See src/HOL/SMT.
   636 
   637 * New commands to load and prove verification conditions generated by
   638 the Boogie program verifier or derived systems (e.g. the Verifying C
   639 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   640 
   641 * New counterexample generator tool 'nitpick' based on the Kodkod
   642 relational model finder.  See src/HOL/Tools/Nitpick and
   643 src/HOL/Nitpick_Examples.
   644 
   645 * New commands 'code_pred' and 'values' to invoke the predicate
   646 compiler and to enumerate values of inductive predicates.
   647 
   648 * A tabled implementation of the reflexive transitive closure.
   649 
   650 * New implementation of quickcheck uses generic code generator;
   651 default generators are provided for all suitable HOL types, records
   652 and datatypes.  Old quickcheck can be re-activated importing theory
   653 Library/SML_Quickcheck.
   654 
   655 * New testing tool Mirabelle for automated proof tools.  Applies
   656 several tools and tactics like sledgehammer, metis, or quickcheck, to
   657 every proof step in a theory.  To be used in batch mode via the
   658 "mirabelle" utility.
   659 
   660 * New proof method "sos" (sum of squares) for nonlinear real
   661 arithmetic (originally due to John Harison). It requires theory
   662 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   663 works well in practice on quantifier-free real arithmetic with +, -,
   664 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   665 inequalities between polynomials.  It makes use of external
   666 semidefinite programming solvers.  Method "sos" generates a
   667 certificate that can be pasted into the proof thus avoiding the need
   668 to call an external tool every time the proof is checked.  See
   669 src/HOL/Library/Sum_Of_Squares.
   670 
   671 * New method "linarith" invokes existing linear arithmetic decision
   672 procedure only.
   673 
   674 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   675 
   676 * New Sledgehammer option "Full Types" in Proof General settings menu.
   677 Causes full type information to be output to the ATPs.  This slows
   678 ATPs down considerably but eliminates a source of unsound "proofs"
   679 that fail later.
   680 
   681 * New method "metisFT": A version of metis that uses full type
   682 information in order to avoid failures of proof reconstruction.
   683 
   684 * New evaluator "approximate" approximates an real valued term using
   685 the same method as the approximation method.
   686 
   687 * Method "approximate" now supports arithmetic expressions as
   688 boundaries of intervals and implements interval splitting and Taylor
   689 series expansion.
   690 
   691 * ML antiquotation @{code_datatype} inserts definition of a datatype
   692 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   693 
   694 * New theory SupInf of the supremum and infimum operators for sets of
   695 reals.
   696 
   697 * New theory Probability, which contains a development of measure
   698 theory, eventually leading to Lebesgue integration and probability.
   699 
   700 * Extended Multivariate Analysis to include derivation and Brouwer's
   701 fixpoint theorem.
   702 
   703 * Reorganization of number theory, INCOMPATIBILITY:
   704   - new number theory development for nat and int, in theories Divides
   705     and GCD as well as in new session Number_Theory
   706   - some constants and facts now suffixed with _nat and _int
   707     accordingly
   708   - former session NumberTheory now named Old_Number_Theory, including
   709     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   710   - moved theory Pocklington from src/HOL/Library to
   711     src/HOL/Old_Number_Theory
   712 
   713 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   714 lcm of finite and infinite sets. It is shown that they form a complete
   715 lattice.
   716 
   717 * Class semiring_div requires superclass no_zero_divisors and proof of
   718 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   719 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   720 generalized to class semiring_div, subsuming former theorems
   721 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   722 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   723 INCOMPATIBILITY.
   724 
   725 * Refinements to lattice classes and sets:
   726   - less default intro/elim rules in locale variant, more default
   727     intro/elim rules in class variant: more uniformity
   728   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   729     le_inf_iff
   730   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   731     sup_aci)
   732   - renamed ACI to inf_sup_aci
   733   - new class "boolean_algebra"
   734   - class "complete_lattice" moved to separate theory
   735     "Complete_Lattice"; corresponding constants (and abbreviations)
   736     renamed and with authentic syntax:
   737     Set.Inf ~>    Complete_Lattice.Inf
   738     Set.Sup ~>    Complete_Lattice.Sup
   739     Set.INFI ~>   Complete_Lattice.INFI
   740     Set.SUPR ~>   Complete_Lattice.SUPR
   741     Set.Inter ~>  Complete_Lattice.Inter
   742     Set.Union ~>  Complete_Lattice.Union
   743     Set.INTER ~>  Complete_Lattice.INTER
   744     Set.UNION ~>  Complete_Lattice.UNION
   745   - authentic syntax for
   746     Set.Pow
   747     Set.image
   748   - mere abbreviations:
   749     Set.empty               (for bot)
   750     Set.UNIV                (for top)
   751     Set.inter               (for inf, formerly Set.Int)
   752     Set.union               (for sup, formerly Set.Un)
   753     Complete_Lattice.Inter  (for Inf)
   754     Complete_Lattice.Union  (for Sup)
   755     Complete_Lattice.INTER  (for INFI)
   756     Complete_Lattice.UNION  (for SUPR)
   757   - object-logic definitions as far as appropriate
   758 
   759 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   760 Un_subset_iff are explicitly deleted as default simp rules; then also
   761 their lattice counterparts le_inf_iff and le_sup_iff have to be
   762 deleted to achieve the desired effect.
   763 
   764 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   765 rules by default any longer; the same applies to min_max.inf_absorb1
   766 etc.  INCOMPATIBILITY.
   767 
   768 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   769 pred_set_conv by default.  INCOMPATIBILITY.
   770 
   771 * Power operations on relations and functions are now one dedicated
   772 constant "compow" with infix syntax "^^".  Power operation on
   773 multiplicative monoids retains syntax "^" and is now defined generic
   774 in class power.  INCOMPATIBILITY.
   775 
   776 * Relation composition "R O S" now has a more standard argument order:
   777 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   778 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   779 break, since the O_assoc rule was not rewritten like this.  Fix using
   780 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   781 
   782 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   783 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   784 INCOMPATIBILITY.
   785 
   786 * Most rules produced by inductive and datatype package have mandatory
   787 prefixes.  INCOMPATIBILITY.
   788 
   789 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   790 the attribute of the same name.  Each of the theorems in the list
   791 DERIV_intros assumes composition with an additional function and
   792 matches a variable to the derivative, which has to be solved by the
   793 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   794 of most elementary terms.  Former Maclauren.DERIV_tac and
   795 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   796 INCOMPATIBILITY.
   797 
   798 * Code generator attributes follow the usual underscore convention:
   799     code_unfold     replaces    code unfold
   800     code_post       replaces    code post
   801     etc.
   802   INCOMPATIBILITY.
   803 
   804 * Renamed methods:
   805     sizechange -> size_change
   806     induct_scheme -> induction_schema
   807   INCOMPATIBILITY.
   808 
   809 * Discontinued abbreviation "arbitrary" of constant "undefined".
   810 INCOMPATIBILITY, use "undefined" directly.
   811 
   812 * Renamed theorems:
   813     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   814     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   815     Suc_plus1 -> Suc_eq_plus1
   816     *anti_sym -> *antisym*
   817     vector_less_eq_def -> vector_le_def
   818   INCOMPATIBILITY.
   819 
   820 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   821 INCOMPATIBILITY.
   822 
   823 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   824 INCOMPATIBILITY.
   825 
   826 
   827 *** HOLCF ***
   828 
   829 * Theory Representable defines a class "rep" of domains that are
   830 representable (via an ep-pair) in the universal domain type "udom".
   831 Instances are provided for all type constructors defined in HOLCF.
   832 
   833 * The 'new_domain' command is a purely definitional version of the
   834 domain package, for representable domains.  Syntax is identical to the
   835 old domain package.  The 'new_domain' package also supports indirect
   836 recursion using previously-defined type constructors.  See
   837 src/HOLCF/ex/New_Domain.thy for examples.
   838 
   839 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   840 on the left-hand side of an equation, and then performs
   841 simplification.  Rewriting is done using rules declared with the
   842 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   843 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   844 
   845 * The pattern-match compiler in 'fixrec' can now handle constructors
   846 with HOL function types.  Pattern-match combinators for the Pair
   847 constructor are pre-configured.
   848 
   849 * The 'fixrec' package now produces better fixed-point induction rules
   850 for mutually-recursive definitions:  Induction rules have conclusions
   851 of the form "P foo bar" instead of "P <foo, bar>".
   852 
   853 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   854 been renamed to "below".  The name "below" now replaces "less" in many
   855 theorem names.  (Legacy theorem names using "less" are still supported
   856 as well.)
   857 
   858 * The 'fixrec' package now supports "bottom patterns".  Bottom
   859 patterns can be used to generate strictness rules, or to make
   860 functions more strict (much like the bang-patterns supported by the
   861 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   862 examples.
   863 
   864 
   865 *** ML ***
   866 
   867 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   868 errors and run-time exceptions, including detailed source positions.
   869 
   870 * Structure Name_Space (formerly NameSpace) now manages uniquely
   871 identified entries, with some additional information such as source
   872 position, logical grouping etc.
   873 
   874 * Theory and context data is now introduced by the simplified and
   875 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   876 to be pure, but the old TheoryDataFun for mutable data (with explicit
   877 copy operation) is still available for some time.
   878 
   879 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   880 provides a high-level programming interface to synchronized state
   881 variables with atomic update.  This works via pure function
   882 application within a critical section -- its runtime should be as
   883 short as possible; beware of deadlocks if critical code is nested,
   884 either directly or indirectly via other synchronized variables!
   885 
   886 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   887 wraps raw ML references, explicitly indicating their non-thread-safe
   888 behaviour.  The Isar toplevel keeps this structure open, to
   889 accommodate Proof General as well as quick and dirty interactive
   890 experiments with references.
   891 
   892 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   893 parallel tactical reasoning.
   894 
   895 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   896 are similar to SUBPROOF, but are slightly more flexible: only the
   897 specified parts of the subgoal are imported into the context, and the
   898 body tactic may introduce new subgoals and schematic variables.
   899 
   900 * Old tactical METAHYPS, which does not observe the proof context, has
   901 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   902 or Subgoal.FOCUS etc.
   903 
   904 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   905 functors have their own ML name space there is no point to mark them
   906 separately.)  Minor INCOMPATIBILITY.
   907 
   908 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   909 
   910 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   911 INCOMPATIBILITY.
   912 
   913 * Operations of structure Skip_Proof no longer require quick_and_dirty
   914 mode, which avoids critical setmp.
   915 
   916 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   917 combinators for "args".  INCOMPATIBILITY, need to use simplified
   918 Attrib/Method.setup introduced in Isabelle2009.
   919 
   920 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   921 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   922 last resort.  INCOMPATIBILITY.
   923 
   924 * Display.pretty_thm now requires a proper context (cf. former
   925 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   926 or even Display.pretty_thm_without_context as last resort.
   927 INCOMPATIBILITY.
   928 
   929 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   930 Syntax.pretty_typ/term directly, preferably with proper context
   931 instead of global theory.
   932 
   933 
   934 *** System ***
   935 
   936 * Further fine tuning of parallel proof checking, scales up to 8 cores
   937 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   938 usedir option -q.
   939 
   940 * Support for additional "Isabelle components" via etc/components, see
   941 also the system manual.
   942 
   943 * The isabelle makeall tool now operates on all components with
   944 IsaMakefile, not just hardwired "logics".
   945 
   946 * Removed "compress" option from isabelle-process and isabelle usedir;
   947 this is always enabled.
   948 
   949 * Discontinued support for Poly/ML 4.x versions.
   950 
   951 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   952 on a given logic image.  This requires the lighttpd webserver and is
   953 currently supported on Linux only.
   954 
   955 
   956 
   957 New in Isabelle2009 (April 2009)
   958 --------------------------------
   959 
   960 *** General ***
   961 
   962 * Simplified main Isabelle executables, with less surprises on
   963 case-insensitive file-systems (such as Mac OS).
   964 
   965   - The main Isabelle tool wrapper is now called "isabelle" instead of
   966     "isatool."
   967 
   968   - The former "isabelle" alias for "isabelle-process" has been
   969     removed (should rarely occur to regular users).
   970 
   971   - The former "isabelle-interface" and its alias "Isabelle" have been
   972     removed (interfaces are now regular Isabelle tools).
   973 
   974 Within scripts and make files, the Isabelle environment variables
   975 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   976 respectively.  (The latter are still available as legacy feature.)
   977 
   978 The old isabelle-interface wrapper could react in confusing ways if
   979 the interface was uninstalled or changed otherwise.  Individual
   980 interface tool configuration is now more explicit, see also the
   981 Isabelle system manual.  In particular, Proof General is now available
   982 via "isabelle emacs".
   983 
   984 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   985 purge installed copies of Isabelle executables and re-run "isabelle
   986 install -p ...", or use symlinks.
   987 
   988 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   989 old ~/isabelle, which was slightly non-standard and apt to cause
   990 surprises on case-insensitive file-systems (such as Mac OS).
   991 
   992 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   993 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   994 care is required when using older releases of Isabelle.  Note that
   995 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   996 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   997 
   998 * Proofs of fully specified statements are run in parallel on
   999 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1000 a regular 4-core machine, if the initial heap space is made reasonably
  1001 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1002 
  1003 * The main reference manuals ("isar-ref", "implementation", and
  1004 "system") have been updated and extended.  Formally checked references
  1005 as hyperlinks are now available uniformly.
  1006 
  1007 
  1008 *** Pure ***
  1009 
  1010 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1011 respects.  The most important changes are listed below.  See the
  1012 Tutorial on Locales ("locales" manual) for details.
  1013 
  1014 - In locale expressions, instantiation replaces renaming.  Parameters
  1015 must be declared in a for clause.  To aid compatibility with previous
  1016 parameter inheritance, in locale declarations, parameters that are not
  1017 'touched' (instantiation position "_" or omitted) are implicitly added
  1018 with their syntax at the beginning of the for clause.
  1019 
  1020 - Syntax from abbreviations and definitions in locales is available in
  1021 locale expressions and context elements.  The latter is particularly
  1022 useful in locale declarations.
  1023 
  1024 - More flexible mechanisms to qualify names generated by locale
  1025 expressions.  Qualifiers (prefixes) may be specified in locale
  1026 expressions, and can be marked as mandatory (syntax: "name!:") or
  1027 optional (syntax "name?:").  The default depends for plain "name:"
  1028 depends on the situation where a locale expression is used: in
  1029 commands 'locale' and 'sublocale' prefixes are optional, in
  1030 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1031 implicit qualifiers derived from the parameter names of a locale are
  1032 no longer generated.
  1033 
  1034 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1035 instantiation clause in "interpretation" and "interpret" (square
  1036 brackets) is no longer available.  Use locale expressions.
  1037 
  1038 - When converting proof scripts, mandatory qualifiers in
  1039 'interpretation' and 'interpret' should be retained by default, even
  1040 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1041 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1042 in locale expressions range over a single locale instance only.
  1043 
  1044 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1045 In existing theorem specifications replace the includes element by the
  1046 respective context elements of the included locale, omitting those
  1047 that are already present in the theorem specification.  Multiple
  1048 assume elements of a locale should be replaced by a single one
  1049 involving the locale predicate.  In the proof body, declarations (most
  1050 notably theorems) may be regained by interpreting the respective
  1051 locales in the proof context as required (command "interpret").
  1052 
  1053 If using "includes" in replacement of a target solely because the
  1054 parameter types in the theorem are not as general as in the target,
  1055 consider declaring a new locale with additional type constraints on
  1056 the parameters (context element "constrains").
  1057 
  1058 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1059 
  1060 - Locale interpretation commands no longer attempt to simplify goal.
  1061 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1062 methods intro_locales and unfold_locales to clarify.
  1063 
  1064 - Locale interpretation commands no longer accept interpretation
  1065 attributes.  INCOMPATIBILITY.
  1066 
  1067 * Class declaration: so-called "base sort" must not be given in import
  1068 list any longer, but is inferred from the specification.  Particularly
  1069 in HOL, write
  1070 
  1071     class foo = ...
  1072 
  1073 instead of
  1074 
  1075     class foo = type + ...
  1076 
  1077 * Class target: global versions of theorems stemming do not carry a
  1078 parameter prefix any longer.  INCOMPATIBILITY.
  1079 
  1080 * Class 'instance' command no longer accepts attached definitions.
  1081 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1082 
  1083 * Recovered hiding of consts, which was accidentally broken in
  1084 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1085 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1086 
  1087 * Slightly more coherent Pure syntax, with updated documentation in
  1088 isar-ref manual.  Removed locales meta_term_syntax and
  1089 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1090 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1091 directly in regular applications.
  1092 
  1093 * There is a new syntactic category "float_const" for signed decimal
  1094 fractions (e.g. 123.45 or -123.45).
  1095 
  1096 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1097 interface with 'setup' command instead.
  1098 
  1099 * Command 'local_setup' is similar to 'setup', but operates on a local
  1100 theory context.
  1101 
  1102 * The 'axiomatization' command now only works within a global theory
  1103 context.  INCOMPATIBILITY.
  1104 
  1105 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1106 hypotheses.  Sorts required in the course of reasoning need to be
  1107 covered by the constraints in the initial statement, completed by the
  1108 type instance information of the background theory.  Non-trivial sort
  1109 hypotheses, which rarely occur in practice, may be specified via
  1110 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1111 
  1112   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1113 
  1114 The result contains an implicit sort hypotheses as before --
  1115 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1116 normalization.
  1117 
  1118 * Generalized Isar history, with support for linear undo, direct state
  1119 addressing etc.
  1120 
  1121 * Changed defaults for unify configuration options:
  1122 
  1123   unify_trace_bound = 50 (formerly 25)
  1124   unify_search_bound = 60 (formerly 30)
  1125 
  1126 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1127 
  1128   a) On theory merge, the last set of code equations for a particular
  1129      constant is taken (in accordance with the policy applied by other
  1130      parts of the code generator framework).
  1131 
  1132   b) Code equations stemming from explicit declarations (e.g. code
  1133      attribute) gain priority over default code equations stemming
  1134      from definition, primrec, fun etc.
  1135 
  1136 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1137 
  1138 * Unified theorem tables for both code generators.  Thus [code
  1139 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1140 
  1141 * Command 'find_consts' searches for constants based on type and name
  1142 patterns, e.g.
  1143 
  1144     find_consts "_ => bool"
  1145 
  1146 By default, matching is against subtypes, but it may be restricted to
  1147 the whole type.  Searching by name is possible.  Multiple queries are
  1148 conjunctive and queries may be negated by prefixing them with a
  1149 hyphen:
  1150 
  1151     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1152 
  1153 * New 'find_theorems' criterion "solves" matches theorems that
  1154 directly solve the current goal (modulo higher-order unification).
  1155 
  1156 * Auto solve feature for main theorem statements: whenever a new goal
  1157 is stated, "find_theorems solves" is called; any theorems that could
  1158 solve the lemma directly are listed as part of the goal state.
  1159 Cf. associated options in Proof General Isabelle settings menu,
  1160 enabled by default, with reasonable timeout for pathological cases of
  1161 higher-order unification.
  1162 
  1163 
  1164 *** Document preparation ***
  1165 
  1166 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1167 demanding keyword 'by' and supporting the full method expression
  1168 syntax just like the Isar command 'by'.
  1169 
  1170 
  1171 *** HOL ***
  1172 
  1173 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1174 points Main and Complex_Main remain as before.
  1175 
  1176 * Logic image HOL-Plain provides a minimal HOL with the most important
  1177 tools available (inductive, datatype, primrec, ...).  This facilitates
  1178 experimentation and tool development.  Note that user applications
  1179 (and library theories) should never refer to anything below theory
  1180 Main, as before.
  1181 
  1182 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1183 experimentation due to shorter build times.
  1184 
  1185 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1186 were previously part of former HOL-Complex.  Entry point Hyperreal
  1187 remains valid, but theories formerly using Complex_Main should now use
  1188 new entry point Hypercomplex.
  1189 
  1190 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1191 Posix processes.  Avoids potentially expensive forking of the ML
  1192 process.  New thread-based implementation also works on non-Unix
  1193 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1194 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1195 commands are covered in the isar-ref manual.
  1196 
  1197 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1198 sledgehammer without local ATP installation (Vampire etc.). Other
  1199 provers may be included via suitable ML wrappers, see also
  1200 src/HOL/ATP_Linkup.thy.
  1201 
  1202 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1203 menu.
  1204 
  1205 * The metis method no longer fails because the theorem is too trivial
  1206 (contains the empty clause).
  1207 
  1208 * The metis method now fails in the usual manner, rather than raising
  1209 an exception, if it determines that it cannot prove the theorem.
  1210 
  1211 * Method "coherent" implements a prover for coherent logic (see also
  1212 src/Tools/coherent.ML).
  1213 
  1214 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1215 "undefined" is the right choice to replace "arbitrary", though
  1216 logically there is no difference.  INCOMPATIBILITY.
  1217 
  1218 * Command "value" now integrates different evaluation mechanisms.  The
  1219 result of the first successful evaluation mechanism is printed.  In
  1220 square brackets a particular named evaluation mechanisms may be
  1221 specified (currently, [SML], [code] or [nbe]).  See further
  1222 src/HOL/ex/Eval_Examples.thy.
  1223 
  1224 * Normalization by evaluation now allows non-leftlinear equations.
  1225 Declare with attribute [code nbe].
  1226 
  1227 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1228 as the structured Isar versions "cases" and "induct", cf. the
  1229 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1230 are now presented as a list of individual projections
  1231 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1232 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1233 rare situations a different rule is selected --- notably nested tuple
  1234 elimination instead of former prod.exhaust: use explicit (case_tac t
  1235 rule: prod.exhaust) here.
  1236 
  1237 * Attributes "cases", "induct", "coinduct" support "del" option.
  1238 
  1239 * Removed fact "case_split_thm", which duplicates "case_split".
  1240 
  1241 * The option datatype has been moved to a new theory Option.  Renamed
  1242 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1243 
  1244 * New predicate "strict_mono" classifies strict functions on partial
  1245 orders.  With strict functions on linear orders, reasoning about
  1246 (in)equalities is facilitated by theorems "strict_mono_eq",
  1247 "strict_mono_less_eq" and "strict_mono_less".
  1248 
  1249 * Some set operations are now proper qualified constants with
  1250 authentic syntax.  INCOMPATIBILITY:
  1251 
  1252     op Int ~>   Set.Int
  1253     op Un ~>    Set.Un
  1254     INTER ~>    Set.INTER
  1255     UNION ~>    Set.UNION
  1256     Inter ~>    Set.Inter
  1257     Union ~>    Set.Union
  1258     {} ~>       Set.empty
  1259     UNIV ~>     Set.UNIV
  1260 
  1261 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1262 theory Set.
  1263 
  1264 * Auxiliary class "itself" has disappeared -- classes without any
  1265 parameter are treated as expected by the 'class' command.
  1266 
  1267 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1268 
  1269 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1270 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1271 
  1272 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1273 method "approximation".  It proves formulas on real values by using
  1274 interval arithmetic.  In the formulas are also the transcendental
  1275 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1276 allowed. For examples see
  1277 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1278 
  1279 * Theory "Reflection" now resides in HOL/Library.
  1280 
  1281 * Entry point to Word library now simply named "Word".
  1282 INCOMPATIBILITY.
  1283 
  1284 * Made source layout more coherent with logical distribution
  1285 structure:
  1286 
  1287     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1288     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1289     src/HOL/Library/GCD.thy ~> src/HOL/
  1290     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1291     src/HOL/Library/Parity.thy ~> src/HOL/
  1292     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1293     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1294     src/HOL/Real/Lubs.thy ~> src/HOL/
  1295     src/HOL/Real/PReal.thy ~> src/HOL/
  1296     src/HOL/Real/Rational.thy ~> src/HOL/
  1297     src/HOL/Real/RComplete.thy ~> src/HOL/
  1298     src/HOL/Real/RealDef.thy ~> src/HOL/
  1299     src/HOL/Real/RealPow.thy ~> src/HOL/
  1300     src/HOL/Real/Real.thy ~> src/HOL/
  1301     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1302     src/HOL/Complex/Complex.thy ~> src/HOL/
  1303     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1304     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1305     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1306     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1307     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1308     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1309     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1310     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1311     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1312     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1313     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1314     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1315     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1316     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1317     src/HOL/Real/Float ~> src/HOL/Library/
  1318     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1319     src/HOL/Real/RealVector.thy ~> src/HOL/
  1320 
  1321     src/HOL/arith_data.ML ~> src/HOL/Tools
  1322     src/HOL/hologic.ML ~> src/HOL/Tools
  1323     src/HOL/simpdata.ML ~> src/HOL/Tools
  1324     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1325     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1326     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1327     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1328     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1329     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1330     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1331 
  1332     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1333     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1334     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1335     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1336     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1337     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1338 
  1339 * If methods "eval" and "evaluation" encounter a structured proof
  1340 state with !!/==>, only the conclusion is evaluated to True (if
  1341 possible), avoiding strange error messages.
  1342 
  1343 * Method "sizechange" automates termination proofs using (a
  1344 modification of) the size-change principle.  Requires SAT solver.  See
  1345 src/HOL/ex/Termination.thy for examples.
  1346 
  1347 * Simplifier: simproc for let expressions now unfolds if bound
  1348 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1349 
  1350 * Method "arith": Linear arithmetic now ignores all inequalities when
  1351 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1352 
  1353 * New attribute "arith" for facts that should always be used
  1354 automatically by arithmetic. It is intended to be used locally in
  1355 proofs, e.g.
  1356 
  1357   assumes [arith]: "x > 0"
  1358 
  1359 Global usage is discouraged because of possible performance impact.
  1360 
  1361 * New classes "top" and "bot" with corresponding operations "top" and
  1362 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1363 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1364 
  1365 * Changed definition lemma "less_fun_def" in order to provide an
  1366 instance for preorders on functions; use lemma "less_le" instead.
  1367 INCOMPATIBILITY.
  1368 
  1369 * Theory Orderings: class "wellorder" moved here, with explicit
  1370 induction rule "less_induct" as assumption.  For instantiation of
  1371 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1372 INCOMPATIBILITY.
  1373 
  1374 * Theory Orderings: added class "preorder" as superclass of "order".
  1375 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1376 etc. slightly changed.  Some theorems named order_class.* now named
  1377 preorder_class.*.
  1378 
  1379 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1380 "diag" to "Id_on".
  1381 
  1382 * Theory Finite_Set: added a new fold combinator of type
  1383 
  1384   ('a => 'b => 'b) => 'b => 'a set => 'b
  1385 
  1386 Occasionally this is more convenient than the old fold combinator
  1387 which is now defined in terms of the new one and renamed to
  1388 fold_image.
  1389 
  1390 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1391 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1392 extended with further lemmas!).  At the moment both still exist but
  1393 the former will disappear at some point.
  1394 
  1395 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1396 class recpower.  Type-specific simp rules for various recpower types
  1397 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1398 
  1399 rat_power_0    -> power_0
  1400 rat_power_Suc  -> power_Suc
  1401 realpow_0      -> power_0
  1402 realpow_Suc    -> power_Suc
  1403 complexpow_0   -> power_0
  1404 complexpow_Suc -> power_Suc
  1405 power_poly_0   -> power_0
  1406 power_poly_Suc -> power_Suc
  1407 
  1408 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1409 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1410 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1411 of lemmas from Divides has been generalized from nat to class
  1412 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1413 renames resulting from duplicate elimination:
  1414 
  1415     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1416     zero_dvd_iff ~>         dvd_0_left_iff
  1417     dvd_0 ~>                dvd_0_right
  1418     DIVISION_BY_ZERO_DIV ~> div_by_0
  1419     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1420     mult_div ~>             div_mult_self2_is_id
  1421     mult_mod ~>             mod_mult_self2_is_0
  1422 
  1423 * Theory IntDiv: removed many lemmas that are instances of class-based
  1424 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1425 rename old lemmas as follows:
  1426 
  1427 dvd_diff               -> nat_dvd_diff
  1428 dvd_zminus_iff         -> dvd_minus_iff
  1429 mod_add1_eq            -> mod_add_eq
  1430 mod_mult1_eq           -> mod_mult_right_eq
  1431 mod_mult1_eq'          -> mod_mult_left_eq
  1432 mod_mult_distrib_mod   -> mod_mult_eq
  1433 nat_mod_add_left_eq    -> mod_add_left_eq
  1434 nat_mod_add_right_eq   -> mod_add_right_eq
  1435 nat_mod_div_trivial    -> mod_div_trivial
  1436 nat_mod_mod_trivial    -> mod_mod_trivial
  1437 zdiv_zadd_self1        -> div_add_self1
  1438 zdiv_zadd_self2        -> div_add_self2
  1439 zdiv_zmult_self1       -> div_mult_self2_is_id
  1440 zdiv_zmult_self2       -> div_mult_self1_is_id
  1441 zdvd_triv_left         -> dvd_triv_left
  1442 zdvd_triv_right        -> dvd_triv_right
  1443 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1444 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1445 zmod_zadd_left_eq      -> mod_add_left_eq
  1446 zmod_zadd_right_eq     -> mod_add_right_eq
  1447 zmod_zadd_self1        -> mod_add_self1
  1448 zmod_zadd_self2        -> mod_add_self2
  1449 zmod_zadd1_eq          -> mod_add_eq
  1450 zmod_zdiff1_eq         -> mod_diff_eq
  1451 zmod_zdvd_zmod         -> mod_mod_cancel
  1452 zmod_zmod_cancel       -> mod_mod_cancel
  1453 zmod_zmult_self1       -> mod_mult_self2_is_0
  1454 zmod_zmult_self2       -> mod_mult_self1_is_0
  1455 zmod_1                 -> mod_by_1
  1456 zdiv_1                 -> div_by_1
  1457 zdvd_abs1              -> abs_dvd_iff
  1458 zdvd_abs2              -> dvd_abs_iff
  1459 zdvd_refl              -> dvd_refl
  1460 zdvd_trans             -> dvd_trans
  1461 zdvd_zadd              -> dvd_add
  1462 zdvd_zdiff             -> dvd_diff
  1463 zdvd_zminus_iff        -> dvd_minus_iff
  1464 zdvd_zminus2_iff       -> minus_dvd_iff
  1465 zdvd_zmultD            -> dvd_mult_right
  1466 zdvd_zmultD2           -> dvd_mult_left
  1467 zdvd_zmult_mono        -> mult_dvd_mono
  1468 zdvd_0_right           -> dvd_0_right
  1469 zdvd_0_left            -> dvd_0_left_iff
  1470 zdvd_1_left            -> one_dvd
  1471 zminus_dvd_iff         -> minus_dvd_iff
  1472 
  1473 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1474 
  1475 * The real numbers offer decimal input syntax: 12.34 is translated
  1476 into 1234/10^2. This translation is not reversed upon output.
  1477 
  1478 * Theory Library/Polynomial defines an abstract type 'a poly of
  1479 univariate polynomials with coefficients of type 'a.  In addition to
  1480 the standard ring operations, it also supports div and mod.  Code
  1481 generation is also supported, using list-style constructors.
  1482 
  1483 * Theory Library/Inner_Product defines a class of real_inner for real
  1484 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1485 => real.  Class real_inner is a subclass of real_normed_vector from
  1486 theory RealVector.
  1487 
  1488 * Theory Library/Product_Vector provides instances for the product
  1489 type 'a * 'b of several classes from RealVector and Inner_Product.
  1490 Definitions of addition, subtraction, scalar multiplication, norms,
  1491 and inner products are included.
  1492 
  1493 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1494 addition to the field operations, numerals and case syntax are also
  1495 supported.
  1496 
  1497 * Theory Library/Diagonalize provides constructive version of Cantor's
  1498 first diagonalization argument.
  1499 
  1500 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1501 zlcm (for int); carried together from various gcd/lcm developements in
  1502 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1503 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1504 may recover tupled syntax as follows:
  1505 
  1506     hide (open) const gcd
  1507     abbreviation gcd where
  1508       "gcd == (%(a, b). GCD.gcd a b)"
  1509     notation (output)
  1510       GCD.gcd ("gcd '(_, _')")
  1511 
  1512 The same works for lcm, zgcd, zlcm.
  1513 
  1514 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1515 instantiations for algebraic structures.  Removed some duplicate
  1516 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1517 
  1518 * ML antiquotation @{code} takes a constant as argument and generates
  1519 corresponding code in background and inserts name of the corresponding
  1520 resulting ML value/function/datatype constructor binding in place.
  1521 All occurrences of @{code} with a single ML block are generated
  1522 simultaneously.  Provides a generic and safe interface for
  1523 instrumentalizing code generation.  See
  1524 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1525 In future you ought to refrain from ad-hoc compiling generated SML
  1526 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1527 cannot refer to constants for which user-defined serializations are
  1528 set.  Refer to the corresponding ML counterpart directly in that
  1529 cases.
  1530 
  1531 * Command 'rep_datatype': instead of theorem names the command now
  1532 takes a list of terms denoting the constructors of the type to be
  1533 represented as datatype.  The characteristic theorems have to be
  1534 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1535 have disappeared in favour of existing ones:
  1536 
  1537     unit_induct                 ~> unit.induct
  1538     prod_induct                 ~> prod.induct
  1539     sum_induct                  ~> sum.induct
  1540     Suc_Suc_eq                  ~> nat.inject
  1541     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1542 
  1543 
  1544 *** HOL-Algebra ***
  1545 
  1546 * New locales for orders and lattices where the equivalence relation
  1547 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1548 locales use a record structure with field eq for the equivalence.
  1549 
  1550 * New theory of factorial domains.
  1551 
  1552 * Units_l_inv and Units_r_inv are now simp rules by default.
  1553 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1554 and/or r_inv will now also require deletion of these lemmas.
  1555 
  1556 * Renamed the following theorems, INCOMPATIBILITY:
  1557 
  1558 UpperD ~> Upper_memD
  1559 LowerD ~> Lower_memD
  1560 least_carrier ~> least_closed
  1561 greatest_carrier ~> greatest_closed
  1562 greatest_Lower_above ~> greatest_Lower_below
  1563 one_zero ~> carrier_one_zero
  1564 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1565 
  1566 
  1567 *** HOL-Nominal ***
  1568 
  1569 * Nominal datatypes can now contain type-variables.
  1570 
  1571 * Commands 'nominal_inductive' and 'equivariance' work with local
  1572 theory targets.
  1573 
  1574 * Nominal primrec can now works with local theory targets and its
  1575 specification syntax now conforms to the general format as seen in
  1576 'inductive' etc.
  1577 
  1578 * Method "perm_simp" honours the standard simplifier attributes
  1579 (no_asm), (no_asm_use) etc.
  1580 
  1581 * The new predicate #* is defined like freshness, except that on the
  1582 left hand side can be a set or list of atoms.
  1583 
  1584 * Experimental command 'nominal_inductive2' derives strong induction
  1585 principles for inductive definitions.  In contrast to
  1586 'nominal_inductive', which can only deal with a fixed number of
  1587 binders, it can deal with arbitrary expressions standing for sets of
  1588 atoms to be avoided.  The only inductive definition we have at the
  1589 moment that needs this generalisation is the typing rule for Lets in
  1590 the algorithm W:
  1591 
  1592  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1593  -----------------------------------------------------------------
  1594          Gamma |- Let x be t1 in t2 : T2
  1595 
  1596 In this rule one wants to avoid all the binders that are introduced by
  1597 "close Gamma T1".  We are looking for other examples where this
  1598 feature might be useful.  Please let us know.
  1599 
  1600 
  1601 *** HOLCF ***
  1602 
  1603 * Reimplemented the simplification procedure for proving continuity
  1604 subgoals.  The new simproc is extensible; users can declare additional
  1605 continuity introduction rules with the attribute [cont2cont].
  1606 
  1607 * The continuity simproc now uses a different introduction rule for
  1608 solving continuity subgoals on terms with lambda abstractions.  In
  1609 some rare cases the new simproc may fail to solve subgoals that the
  1610 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1611 Potential INCOMPATIBILITY.
  1612 
  1613 * Command 'fixrec': specification syntax now conforms to the general
  1614 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1615 examples.  INCOMPATIBILITY.
  1616 
  1617 
  1618 *** ZF ***
  1619 
  1620 * Proof of Zorn's Lemma for partial orders.
  1621 
  1622 
  1623 *** ML ***
  1624 
  1625 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1626 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1627 depends on multithreading, so timouts will not work before Poly/ML
  1628 5.2.1!
  1629 
  1630 * High-level support for concurrent ML programming, see
  1631 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1632 particularly convenient to organize independent functional
  1633 computations.  The concept of "synchronized variables" provides a
  1634 higher-order interface for components with shared state, avoiding the
  1635 delicate details of mutexes and condition variables.  (Requires
  1636 Poly/ML 5.2.1 or later.)
  1637 
  1638 * ML bindings produced via Isar commands are stored within the Isar
  1639 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1640 become thread-safe and work with undo as expected (concerning
  1641 top-level bindings, not side-effects on global references).
  1642 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1643 compiler at runtime; really global bindings need to be given outside a
  1644 theory.  (Requires Poly/ML 5.2 or later.)
  1645 
  1646 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1647 context.  Top-level ML bindings are stored within the proof context in
  1648 a purely sequential fashion, disregarding the nested proof structure.
  1649 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1650 proof.  (Requires Poly/ML 5.2 or later.)
  1651 
  1652 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1653 and Method.setup, as well as Isar commands 'attribute_setup' and
  1654 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1655 existing code accordingly, or use plain 'setup' together with old
  1656 Method.add_method.
  1657 
  1658 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1659 to 'a -> thm, while results are always tagged with an authentic oracle
  1660 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1661 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1662 accordingly.  Note that extra performance may be gained by producing
  1663 the cterm carefully, avoiding slow Thm.cterm_of.
  1664 
  1665 * Simplified interface for defining document antiquotations via
  1666 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1667 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1668 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1669 examples.
  1670 
  1671 * More systematic treatment of long names, abstract name bindings, and
  1672 name space operations.  Basic operations on qualified names have been
  1673 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1674 Long_Name.append.  Old type bstring has been mostly replaced by
  1675 abstract type binding (see structure Binding), which supports precise
  1676 qualification by packages and local theory targets, as well as proper
  1677 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1678 bstring values into Binding.name, or better pass through abstract
  1679 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1680 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1681 
  1682 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1683 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1684 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1685 
  1686 * Disposed old type and term read functions (Sign.read_def_typ,
  1687 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1688 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1689 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1690 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1691 resort for legacy applications.
  1692 
  1693 * Disposed old declarations, tactics, tactic combinators that refer to
  1694 the simpset or claset of an implicit theory (such as Addsimps,
  1695 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1696 embedded ML text, or local_simpset_of with a proper context passed as
  1697 explicit runtime argument.
  1698 
  1699 * Rules and tactics that read instantiations (read_instantiate,
  1700 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1701 context, which is required for parsing and type-checking.  Moreover,
  1702 the variables are specified as plain indexnames, not string encodings
  1703 thereof.  INCOMPATIBILITY.
  1704 
  1705 * Generic Toplevel.add_hook interface allows to analyze the result of
  1706 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1707 for theorem dependency output of transactions resulting in a new
  1708 theory state.
  1709 
  1710 * ML antiquotations: block-structured compilation context indicated by
  1711 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1712 
  1713   @{binding name}                         - basic name binding
  1714   @{let ?pat = term}                      - term abbreviation (HO matching)
  1715   @{note name = fact}                     - fact abbreviation
  1716   @{thm fact}                             - singleton fact (with attributes)
  1717   @{thms fact}                            - general fact (with attributes)
  1718   @{lemma prop by method}                 - singleton goal
  1719   @{lemma prop by meth1 meth2}            - singleton goal
  1720   @{lemma prop1 ... propN by method}      - general goal
  1721   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1722   @{lemma (open) ...}                     - open derivation
  1723 
  1724 
  1725 *** System ***
  1726 
  1727 * The Isabelle "emacs" tool provides a specific interface to invoke
  1728 Proof General / Emacs, with more explicit failure if that is not
  1729 installed (the old isabelle-interface script silently falls back on
  1730 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1731 installation location of the Proof General distribution.
  1732 
  1733 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1734 the Isabelle process into a JVM/Scala application.  See
  1735 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1736 process wrapper has been discontinued.)
  1737 
  1738 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1739 
  1740 * Various status messages (with exact source position information) are
  1741 emitted, if proper markup print mode is enabled.  This allows
  1742 user-interface components to provide detailed feedback on internal
  1743 prover operations.
  1744 
  1745 
  1746 
  1747 New in Isabelle2008 (June 2008)
  1748 -------------------------------
  1749 
  1750 *** General ***
  1751 
  1752 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1753 and updated, with formally checked references as hyperlinks.
  1754 
  1755 * Theory loader: use_thy (and similar operations) no longer set the
  1756 implicit ML context, which was occasionally hard to predict and in
  1757 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1758 provides a proper context already.
  1759 
  1760 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1761 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1762 'use' within a theory file will do the job.
  1763 
  1764 * Name space merge now observes canonical order, i.e. the second space
  1765 is inserted into the first one, while existing entries in the first
  1766 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1767 swap theory imports.
  1768 
  1769 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1770 INCOMPATIBILITY in identifier syntax etc.
  1771 
  1772 * Outer syntax: string tokens no longer admit escaped white space,
  1773 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1774 white space without escapes.
  1775 
  1776 * Outer syntax: string tokens may contain arbitrary character codes
  1777 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1778 "foo_bar".
  1779 
  1780 
  1781 *** Pure ***
  1782 
  1783 * Context-dependent token translations.  Default setup reverts locally
  1784 fixed variables, and adds hilite markup for undeclared frees.
  1785 
  1786 * Unused theorems can be found using the new command 'unused_thms'.
  1787 There are three ways of invoking it:
  1788 
  1789 (1) unused_thms
  1790      Only finds unused theorems in the current theory.
  1791 
  1792 (2) unused_thms thy_1 ... thy_n -
  1793      Finds unused theorems in the current theory and all of its ancestors,
  1794      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1795 
  1796 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1797      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1798      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1799      their ancestors.
  1800 
  1801 In order to increase the readability of the list produced by
  1802 unused_thms, theorems that have been created by a particular instance
  1803 of a theory command such as 'inductive' or 'function' are considered
  1804 to belong to the same "group", meaning that if at least one theorem in
  1805 this group is used, the other theorems in the same group are no longer
  1806 reported as unused.  Moreover, if all theorems in the group are
  1807 unused, only one theorem in the group is displayed.
  1808 
  1809 Note that proof objects have to be switched on in order for
  1810 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1811 usually the case when using Proof General with the default settings).
  1812 
  1813 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1814 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1815 duplicate fact bindings, or even accidental fact duplications.  Note
  1816 that tools may maintain dynamically scoped facts systematically, using
  1817 PureThy.add_thms_dynamic.
  1818 
  1819 * Command 'hide' now allows to hide from "fact" name space as well.
  1820 
  1821 * Eliminated destructive theorem database, simpset, claset, and
  1822 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1823 update of theories within ML code.
  1824 
  1825 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1826 INCOMPATIBILITY, object-logics depending on former Pure require
  1827 additional setup PureThy.old_appl_syntax_setup; object-logics
  1828 depending on former CPure need to refer to Pure.
  1829 
  1830 * Commands 'use' and 'ML' are now purely functional, operating on
  1831 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1832 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1833 INCOMPATIBILITY.
  1834 
  1835 * Command 'setup': discontinued implicit version with ML reference.
  1836 
  1837 * Instantiation target allows for simultaneous specification of class
  1838 instance operations together with an instantiation proof.
  1839 Type-checking phase allows to refer to class operations uniformly.
  1840 See src/HOL/Complex/Complex.thy for an Isar example and
  1841 src/HOL/Library/Eval.thy for an ML example.
  1842 
  1843 * Indexing of literal facts: be more serious about including only
  1844 facts from the visible specification/proof context, but not the
  1845 background context (locale etc.).  Affects `prop` notation and method
  1846 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1847 situations.
  1848 
  1849 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1850 "(open)" option, which used to expose internal bound variables to the
  1851 proof text.
  1852 
  1853 * Isar statements: removed obsolete case "rule_context".
  1854 INCOMPATIBILITY, better use explicit fixes/assumes.
  1855 
  1856 * Locale proofs: default proof step now includes 'unfold_locales';
  1857 hence 'proof' without argument may be used to unfold locale
  1858 predicates.
  1859 
  1860 
  1861 *** Document preparation ***
  1862 
  1863 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1864 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1865 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1866 spot); renamed link color from "darkblue" to "linkcolor" (default
  1867 value unchanged, can be redefined via \definecolor); no longer sets
  1868 "a4paper" option (unnecessary or even intrusive).
  1869 
  1870 * Antiquotation @{lemma A method} proves proposition A by the given
  1871 method (either a method name or a method name plus (optional) method
  1872 arguments in parentheses) and prints A just like @{prop A}.
  1873 
  1874 
  1875 *** HOL ***
  1876 
  1877 * New primrec package.  Specification syntax conforms in style to
  1878 definition/function/....  No separate induction rule is provided.  The
  1879 "primrec" command distinguishes old-style and new-style specifications
  1880 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1881 When adjusting theories, beware: constants stemming from new-style
  1882 primrec specifications have authentic syntax.
  1883 
  1884 * Metis prover is now an order of magnitude faster, and also works
  1885 with multithreading.
  1886 
  1887 * Metis: the maximum number of clauses that can be produced from a
  1888 theorem is now given by the attribute max_clauses.  Theorems that
  1889 exceed this number are ignored, with a warning printed.
  1890 
  1891 * Sledgehammer no longer produces structured proofs by default. To
  1892 enable, declare [[sledgehammer_full = true]].  Attributes
  1893 reconstruction_modulus, reconstruction_sorts renamed
  1894 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1895 
  1896 * Method "induct_scheme" derives user-specified induction rules
  1897 from well-founded induction and completeness of patterns. This factors
  1898 out some operations that are done internally by the function package
  1899 and makes them available separately.  See
  1900 src/HOL/ex/Induction_Scheme.thy for examples.
  1901 
  1902 * More flexible generation of measure functions for termination
  1903 proofs: Measure functions can be declared by proving a rule of the
  1904 form "is_measure f" and giving it the [measure_function] attribute.
  1905 The "is_measure" predicate is logically meaningless (always true), and
  1906 just guides the heuristic.  To find suitable measure functions, the
  1907 termination prover sets up the goal "is_measure ?f" of the appropriate
  1908 type and generates all solutions by prolog-style backwards proof using
  1909 the declared rules.
  1910 
  1911 This setup also deals with rules like 
  1912 
  1913   "is_measure f ==> is_measure (list_size f)"
  1914 
  1915 which accommodates nested datatypes that recurse through lists.
  1916 Similar rules are predeclared for products and option types.
  1917 
  1918 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1919 
  1920   INCOMPATIBILITIES:
  1921 
  1922   - Definitions of overloaded constants on sets have to be replaced by
  1923     definitions on => and bool.
  1924 
  1925   - Some definitions of overloaded operators on sets can now be proved
  1926     using the definitions of the operators on => and bool.  Therefore,
  1927     the following theorems have been renamed:
  1928 
  1929       subset_def   -> subset_eq
  1930       psubset_def  -> psubset_eq
  1931       set_diff_def -> set_diff_eq
  1932       Compl_def    -> Compl_eq
  1933       Sup_set_def  -> Sup_set_eq
  1934       Inf_set_def  -> Inf_set_eq
  1935       sup_set_def  -> sup_set_eq
  1936       inf_set_def  -> inf_set_eq
  1937 
  1938   - Due to the incompleteness of the HO unification algorithm, some
  1939     rules such as subst may require manual instantiation, if some of
  1940     the unknowns in the rule is a set.
  1941 
  1942   - Higher order unification and forward proofs:
  1943     The proof pattern
  1944 
  1945       have "P (S::'a set)" <...>
  1946       then have "EX S. P S" ..
  1947 
  1948     no longer works (due to the incompleteness of the HO unification
  1949     algorithm) and must be replaced by the pattern
  1950 
  1951       have "EX S. P S"
  1952       proof
  1953         show "P S" <...>
  1954       qed
  1955 
  1956   - Calculational reasoning with subst (or similar rules):
  1957     The proof pattern
  1958 
  1959       have "P (S::'a set)" <...>
  1960       also have "S = T" <...>
  1961       finally have "P T" .
  1962 
  1963     no longer works (for similar reasons as the previous example) and
  1964     must be replaced by something like
  1965 
  1966       have "P (S::'a set)" <...>
  1967       moreover have "S = T" <...>
  1968       ultimately have "P T" by simp
  1969 
  1970   - Tactics or packages written in ML code:
  1971     Code performing pattern matching on types via
  1972 
  1973       Type ("set", [T]) => ...
  1974 
  1975     must be rewritten. Moreover, functions like strip_type or
  1976     binder_types no longer return the right value when applied to a
  1977     type of the form
  1978 
  1979       T1 => ... => Tn => U => bool
  1980 
  1981     rather than
  1982 
  1983       T1 => ... => Tn => U set
  1984 
  1985 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1986 Wellfounded_Relations to theory Wellfounded.
  1987 
  1988 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1989 
  1990 * Class finite no longer treats UNIV as class parameter.  Use class
  1991 enum from theory Library/Enum instead to achieve a similar effect.
  1992 INCOMPATIBILITY.
  1993 
  1994 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1995 and "Cons".  INCOMPATIBILITY.
  1996 
  1997 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1998 Potential INCOMPATIBILITY.
  1999 
  2000 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2001 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2002 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2003 
  2004 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2005 the same name in theory Orderings:
  2006 
  2007   less_trans
  2008   less_linear
  2009   le_imp_less_or_eq
  2010   le_less_trans
  2011   less_le_trans
  2012   less_not_sym
  2013   less_asym
  2014 
  2015 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2016 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2017 and different variable names.
  2018 
  2019 * Library/Option_ord.thy: Canonical order on option type.
  2020 
  2021 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2022 finite maps.
  2023 
  2024 * Library/Countable.thy: Type class for countable types.
  2025 
  2026 * Theory Int: The representation of numerals has changed.  The infix
  2027 operator BIT and the bit datatype with constructors B0 and B1 have
  2028 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2029 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2030 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2031 accordingly.
  2032 
  2033 * Theory Nat: definition of <= and < on natural numbers no longer
  2034 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2035 le_def and less_def have disappeared.  Consider lemmas not_less
  2036 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2037 
  2038 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2039 (whose purpose mainly is for various fold_set functionals) have been
  2040 abandoned in favor of the existing algebraic classes
  2041 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2042 lower_semilattice (resp. upper_semilattice) and linorder.
  2043 INCOMPATIBILITY.
  2044 
  2045 * Theory Transitive_Closure: induct and cases rules now declare proper
  2046 case_names ("base" and "step").  INCOMPATIBILITY.
  2047 
  2048 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2049 lattices.  The form set-specific version is available as
  2050 Inductive.lfp_ordinal_induct_set.
  2051 
  2052 * Renamed theorems "power.simps" to "power_int.simps".
  2053 INCOMPATIBILITY.
  2054 
  2055 * Class semiring_div provides basic abstract properties of semirings
  2056 with division and modulo operations.  Subsumes former class dvd_mod.
  2057 
  2058 * Merged theories IntDef, Numeral and IntArith into unified theory
  2059 Int.  INCOMPATIBILITY.
  2060 
  2061 * Theory Library/Code_Index: type "index" now represents natural
  2062 numbers rather than integers.  INCOMPATIBILITY.
  2063 
  2064 * New class "uminus" with operation "uminus" (split of from class
  2065 "minus" which now only has operation "minus", binary).
  2066 INCOMPATIBILITY.
  2067 
  2068 * Constants "card", "internal_split", "option_map" now with authentic
  2069 syntax.  INCOMPATIBILITY.
  2070 
  2071 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2072 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2073 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2074 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2075 Sup_set_def, le_def, less_def, option_map_def now with object
  2076 equality.  INCOMPATIBILITY.
  2077 
  2078 * Records. Removed K_record, and replaced it by pure lambda term
  2079 %x. c. The simplifier setup is now more robust against eta expansion.
  2080 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2081 
  2082 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2083 
  2084 * Library/ListVector: new theory of arithmetic vector operations.
  2085 
  2086 * Library/Order_Relation: new theory of various orderings as sets of
  2087 pairs.  Defines preorders, partial orders, linear orders and
  2088 well-orders on sets and on types.
  2089 
  2090 
  2091 *** ZF ***
  2092 
  2093 * Renamed some theories to allow to loading both ZF and HOL in the
  2094 same session:
  2095 
  2096   Datatype  -> Datatype_ZF
  2097   Inductive -> Inductive_ZF
  2098   Int       -> Int_ZF
  2099   IntDiv    -> IntDiv_ZF
  2100   Nat       -> Nat_ZF
  2101   List      -> List_ZF
  2102   Main      -> Main_ZF
  2103 
  2104 INCOMPATIBILITY: ZF theories that import individual theories below
  2105 Main might need to be adapted.  Regular theory Main is still
  2106 available, as trivial extension of Main_ZF.
  2107 
  2108 
  2109 *** ML ***
  2110 
  2111 * ML within Isar: antiquotation @{const name} or @{const
  2112 name(typargs)} produces statically-checked Const term.
  2113 
  2114 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2115 (of the same name).  Removed obsolete print command.
  2116 
  2117 * Removed obsolete "use_legacy_bindings" function.
  2118 
  2119 * The ``print mode'' is now a thread-local value derived from a global
  2120 template (the former print_mode reference), thus access becomes
  2121 non-critical.  The global print_mode reference is for session
  2122 management only; user-code should use print_mode_value,
  2123 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2124 
  2125 * Functions system/system_out provide a robust way to invoke external
  2126 shell commands, with propagation of interrupts (requires Poly/ML
  2127 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2128 
  2129 
  2130 *** System ***
  2131 
  2132 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2133 in accordance with Proof General 3.7, which prefers GNU emacs.
  2134 
  2135 * isatool tty runs Isabelle process with plain tty interaction;
  2136 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2137 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2138 
  2139 * isatool browser now works with Cygwin as well, using general
  2140 "javapath" function defined in Isabelle process environment.
  2141 
  2142 * YXML notation provides a simple and efficient alternative to
  2143 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2144 isatool yxml as described in the Isabelle system manual.
  2145 
  2146 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2147 provides general wrapper for managing an Isabelle process in a robust
  2148 fashion, with ``cooked'' output from stdin/stderr.
  2149 
  2150 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2151 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2152 
  2153 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2154 way of changing the user's settings is via
  2155 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2156 script.
  2157 
  2158 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2159 cores of the underlying machine, which is a good starting point for
  2160 optimal performance tuning.  The corresponding usedir option -M allows
  2161 "max" as an alias for "0".  WARNING: does not work on certain versions
  2162 of Mac OS (with Poly/ML 5.1).
  2163 
  2164 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2165 adverse effect of Isabelle flooding interactive front-ends (notably
  2166 ProofGeneral / XEmacs).
  2167 
  2168 
  2169 
  2170 New in Isabelle2007 (November 2007)
  2171 -----------------------------------
  2172 
  2173 *** General ***
  2174 
  2175 * More uniform information about legacy features, notably a
  2176 warning/error of "Legacy feature: ...", depending on the state of the
  2177 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2178 legacy features will disappear eventually.
  2179 
  2180 * Theory syntax: the header format ``theory A = B + C:'' has been
  2181 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2182 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2183 
  2184 * Theory syntax: the old non-Isar theory file format has been
  2185 discontinued altogether.  Note that ML proof scripts may still be used
  2186 with Isar theories; migration is usually quite simple with the ML
  2187 function use_legacy_bindings.  INCOMPATIBILITY.
  2188 
  2189 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2190 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2191 quotes.
  2192 
  2193 * Theory loader: be more serious about observing the static theory
  2194 header specifications (including optional directories), but not the
  2195 accidental file locations of previously successful loads.  The strict
  2196 update policy of former update_thy is now already performed by
  2197 use_thy, so the former has been removed; use_thys updates several
  2198 theories simultaneously, just as 'imports' within a theory header
  2199 specification, but without merging the results.  Potential
  2200 INCOMPATIBILITY: may need to refine theory headers and commands
  2201 ROOT.ML which depend on load order.
  2202 
  2203 * Theory loader: optional support for content-based file
  2204 identification, instead of the traditional scheme of full physical
  2205 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2206 (cf. the system manual).  The new scheme allows to work with
  2207 non-finished theories in persistent session images, such that source
  2208 files may be moved later on without requiring reloads.
  2209 
  2210 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2211 file (with the same base name as the theory) are considered a legacy
  2212 feature, which will disappear eventually. Even now, the theory loader
  2213 no longer maintains dependencies on such files.
  2214 
  2215 * Syntax: the scope for resolving ambiguities via type-inference is
  2216 now limited to individual terms, instead of whole simultaneous
  2217 specifications as before. This greatly reduces the complexity of the
  2218 syntax module and improves flexibility by separating parsing and
  2219 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2220 'fixes' etc.) are required in rare situations.
  2221 
  2222 * Syntax: constants introduced by new-style packages ('definition',
  2223 'abbreviation' etc.) are passed through the syntax module in
  2224 ``authentic mode''. This means that associated mixfix annotations
  2225 really stick to such constants, independently of potential name space
  2226 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2227 trees are represented slightly differently, may need to adapt syntax
  2228 translations accordingly. Use CONST marker in 'translations' and
  2229 @{const_syntax} antiquotation in 'parse_translation' etc.
  2230 
  2231 * Legacy goal package: reduced interface to the bare minimum required
  2232 to keep existing proof scripts running.  Most other user-level
  2233 functions are now part of the OldGoals structure, which is *not* open
  2234 by default (consider isatool expandshort before open OldGoals).
  2235 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2236 these tend to cause confusion about the actual goal (!) context being
  2237 used here, which is not necessarily the same as the_context().
  2238 
  2239 * Command 'find_theorems': supports "*" wild-card in "name:"
  2240 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2241 support a specific search form (see ProofGeneral/CHANGES).
  2242 
  2243 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2244 by default, which means that "prems" (and also "fixed variables") are
  2245 suppressed from proof state output.  Note that the ProofGeneral
  2246 settings mechanism allows to change and save options persistently, but
  2247 older versions of Isabelle will fail to start up if a negative prems
  2248 limit is imposed.
  2249 
  2250 * Local theory targets may be specified by non-nested blocks of
  2251 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2252 contain definitions, theorems etc., including any derived mechanism
  2253 that has been implemented on top of these primitives.  This concept
  2254 generalizes the existing ``theorem (in ...)'' towards more versatility
  2255 and scalability.
  2256 
  2257 * Proof General interface: proper undo of final 'end' command;
  2258 discontinued Isabelle/classic mode (ML proof scripts).
  2259 
  2260 
  2261 *** Document preparation ***
  2262 
  2263 * Added antiquotation @{theory name} which prints the given name,
  2264 after checking that it refers to a valid ancestor theory in the
  2265 current context.
  2266 
  2267 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2268 check the given source text as ML type/structure, printing verbatim.
  2269 
  2270 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2271 "c args == rhs" given in the current context.  (Any number of
  2272 arguments may be given on the LHS.)
  2273 
  2274 
  2275 *** Pure ***
  2276 
  2277 * The 'class' package offers a combination of axclass and locale to
  2278 achieve Haskell-like type classes in Isabelle.  Definitions and
  2279 theorems within a class context produce both relative results (with
  2280 implicit parameters according to the locale context), and polymorphic
  2281 constants with qualified polymorphism (according to the class
  2282 context).  Within the body context of a 'class' target, a separate
  2283 syntax layer ("user space type system") takes care of converting
  2284 between global polymorphic consts and internal locale representation.
  2285 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2286 "isatool doc classes" provides a tutorial.
  2287 
  2288 * Generic code generator framework allows to generate executable
  2289 code for ML and Haskell (including Isabelle classes).  A short usage
  2290 sketch:
  2291 
  2292     internal compilation:
  2293         export_code <list of constants (term syntax)> in SML
  2294     writing SML code to a file:
  2295         export_code <list of constants (term syntax)> in SML <filename>
  2296     writing OCaml code to a file:
  2297         export_code <list of constants (term syntax)> in OCaml <filename>
  2298     writing Haskell code to a bunch of files:
  2299         export_code <list of constants (term syntax)> in Haskell <filename>
  2300 
  2301     evaluating closed propositions to True/False using code generation:
  2302         method ``eval''
  2303 
  2304 Reasonable default setup of framework in HOL.
  2305 
  2306 Theorem attributs for selecting and transforming function equations theorems:
  2307 
  2308     [code fun]:        select a theorem as function equation for a specific constant
  2309     [code fun del]:    deselect a theorem as function equation for a specific constant
  2310     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2311     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2312 
  2313 User-defined serializations (target in {SML, OCaml, Haskell}):
  2314 
  2315     code_const <and-list of constants (term syntax)>
  2316       {(target) <and-list of const target syntax>}+
  2317 
  2318     code_type <and-list of type constructors>
  2319       {(target) <and-list of type target syntax>}+
  2320 
  2321     code_instance <and-list of instances>
  2322       {(target)}+
  2323         where instance ::= <type constructor> :: <class>
  2324 
  2325     code_class <and_list of classes>
  2326       {(target) <and-list of class target syntax>}+
  2327         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2328 
  2329 code_instance and code_class only are effective to target Haskell.
  2330 
  2331 For example usage see src/HOL/ex/Codegenerator.thy and
  2332 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2333 generation from Isabelle/HOL theories is available via "isatool doc
  2334 codegen".
  2335 
  2336 * Code generator: consts in 'consts_code' Isar commands are now
  2337 referred to by usual term syntax (including optional type
  2338 annotations).
  2339 
  2340 * Command 'no_translations' removes translation rules from theory
  2341 syntax.
  2342 
  2343 * Overloaded definitions are now actually checked for acyclic
  2344 dependencies.  The overloading scheme is slightly more general than
  2345 that of Haskell98, although Isabelle does not demand an exact
  2346 correspondence to type class and instance declarations.
  2347 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2348 exotic versions of overloading -- at the discretion of the user!
  2349 
  2350 Polymorphic constants are represented via type arguments, i.e. the
  2351 instantiation that matches an instance against the most general
  2352 declaration given in the signature.  For example, with the declaration
  2353 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2354 as c(nat).  Overloading is essentially simultaneous structural
  2355 recursion over such type arguments.  Incomplete specification patterns
  2356 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2357 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2358 Command 'print_theory' outputs the normalized system of recursive
  2359 equations, see section "definitions".
  2360 
  2361 * Configuration options are maintained within the theory or proof
  2362 context (with name and type bool/int/string), providing a very simple
  2363 interface to a poor-man's version of general context data.  Tools may
  2364 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2365 these values using Config.get etc.  Users may change options via an
  2366 associated attribute of the same name.  This form of context
  2367 declaration works particularly well with commands 'declare' or
  2368 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2369 very easy to avoid global references, which would not observe Isar
  2370 toplevel undo/redo and fail to work with multithreading.
  2371 
  2372 Various global ML references of Pure and HOL have been turned into
  2373 configuration options:
  2374 
  2375   Unify.search_bound		unify_search_bound
  2376   Unify.trace_bound		unify_trace_bound
  2377   Unify.trace_simp		unify_trace_simp
  2378   Unify.trace_types		unify_trace_types
  2379   Simplifier.simp_depth_limit	simp_depth_limit
  2380   Blast.depth_limit		blast_depth_limit
  2381   DatatypeProp.dtK		datatype_distinctness_limit
  2382   fast_arith_neq_limit  	fast_arith_neq_limit
  2383   fast_arith_split_limit	fast_arith_split_limit
  2384 
  2385 * Named collections of theorems may be easily installed as context
  2386 data using the functor NamedThmsFun (see also
  2387 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2388 attributes; there is also a toplevel print command.  This facility is
  2389 just a common case of general context data, which is the preferred way
  2390 for anything more complex than just a list of facts in canonical
  2391 order.
  2392 
  2393 * Isar: command 'declaration' augments a local theory by generic
  2394 declaration functions written in ML.  This enables arbitrary content
  2395 being added to the context, depending on a morphism that tells the
  2396 difference of the original declaration context wrt. the application
  2397 context encountered later on.
  2398 
  2399 * Isar: proper interfaces for simplification procedures.  Command
  2400 'simproc_setup' declares named simprocs (with match patterns, and body
  2401 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2402 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2403 
  2404 * Isar: an extra pair of brackets around attribute declarations
  2405 abbreviates a theorem reference involving an internal dummy fact,
  2406 which will be ignored later --- only the effect of the attribute on
  2407 the background context will persist.  This form of in-place
  2408 declarations is particularly useful with commands like 'declare' and
  2409 'using', for example ``have A using [[simproc a]] by simp''.
  2410 
  2411 * Isar: method "assumption" (and implicit closing of subproofs) now
  2412 takes simple non-atomic goal assumptions into account: after applying
  2413 an assumption as a rule the resulting subgoals are solved by atomic
  2414 assumption steps.  This is particularly useful to finish 'obtain'
  2415 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2416 without referring to the original premise "!!x. P x ==> thesis" in the
  2417 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2418 more permissive.
  2419 
  2420 * Isar: implicit use of prems from the Isar proof context is
  2421 considered a legacy feature.  Common applications like ``have A .''
  2422 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2423 referencing facts explicitly here improves readability and
  2424 maintainability of proof texts.
  2425 
  2426 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2427 the obtained context from the course of reasoning!  For example:
  2428 
  2429   assume "EX x y. A x & B y"   -- "any previous fact"
  2430   then guess x and y by clarify
  2431 
  2432 This technique is potentially adventurous, depending on the facts and
  2433 proof tools being involved here.
  2434 
  2435 * Isar: known facts from the proof context may be specified as literal
  2436 propositions, using ASCII back-quote syntax.  This works wherever
  2437 named facts used to be allowed so far, in proof commands, proof
  2438 methods, attributes etc.  Literal facts are retrieved from the context
  2439 according to unification of type and term parameters.  For example,
  2440 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2441 theorems in the current context, then these are valid literal facts:
  2442 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2443 
  2444 There is also a proof method "fact" which does the same composition
  2445 for explicit goal states, e.g. the following proof texts coincide with
  2446 certain special cases of literal facts:
  2447 
  2448   have "A" by fact                 ==  note `A`
  2449   have "A ==> B" by fact           ==  note `A ==> B`
  2450   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2451   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2452 
  2453 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2454 outer syntax.  Thus symbolic identifiers may be used without
  2455 additional white space in declarations like this: ``assume *: A''.
  2456 
  2457 * Isar: 'print_facts' prints all local facts of the current context,
  2458 both named and unnamed ones.
  2459 
  2460 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2461 
  2462   def x == "t" and y == "u"
  2463 
  2464 * Isar: added command 'unfolding', which is structurally similar to
  2465 'using', but affects both the goal state and facts by unfolding given
  2466 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2467 'unfolded' attribute may be replaced by first-class proof text.
  2468 
  2469 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2470 and command 'unfolding' now all support object-level equalities
  2471 (potentially conditional).  The underlying notion of rewrite rule is
  2472 analogous to the 'rule_format' attribute, but *not* that of the
  2473 Simplifier (which is usually more generous).
  2474 
  2475 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2476 premises of a theorem by n. Useful in conjunction with drule.
  2477 
  2478 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2479 method expression within a sandbox consisting of the first N
  2480 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2481 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2482 simplifies all new goals that emerge from applying rule foo to the
  2483 originally first one.
  2484 
  2485 * Isar: schematic goals are no longer restricted to higher-order
  2486 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2487 expected.
  2488 
  2489 * Isar: the conclusion of a long theorem statement is now either
  2490 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2491 (essentially a disjunction of cases with local parameters and
  2492 assumptions).  The latter allows to express general elimination rules
  2493 adequately; in this notation common elimination rules look like this:
  2494 
  2495   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2496     assumes "EX x. P x"
  2497     obtains x where "P x"
  2498 
  2499   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2500     assumes "A & B"
  2501     obtains A and B
  2502 
  2503   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2504     assumes "A | B"
  2505     obtains
  2506       A
  2507     | B
  2508 
  2509 The subsequent classical rules even refer to the formal "thesis"
  2510 explicitly:
  2511 
  2512   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2513     obtains "~ thesis"
  2514 
  2515   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2516     obtains "thesis ==> something"
  2517 
  2518 The actual proof of an 'obtains' statement is analogous to that of the
  2519 Isar proof element 'obtain', only that there may be several cases.
  2520 Optional case names may be specified in parentheses; these will be
  2521 available both in the present proof and as annotations in the
  2522 resulting rule, for later use with the 'cases' method (cf. attribute
  2523 case_names).
  2524 
  2525 * Isar: the assumptions of a long theorem statement are available as
  2526 "assms" fact in the proof context.  This is more appropriate than the
  2527 (historical) "prems", which refers to all assumptions of the current
  2528 context, including those from the target locale, proof body etc.
  2529 
  2530 * Isar: 'print_statement' prints theorems from the current theory or
  2531 proof context in long statement form, according to the syntax of a
  2532 top-level lemma.
  2533 
  2534 * Isar: 'obtain' takes an optional case name for the local context
  2535 introduction rule (default "that").
  2536 
  2537 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2538 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2539 to occur.
  2540 
  2541 * Pure: syntax "CONST name" produces a fully internalized constant
  2542 according to the current context.  This is particularly useful for
  2543 syntax translations that should refer to internal constant
  2544 representations independently of name spaces.
  2545 
  2546 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2547 instead of "FOO ". This allows multiple binder declarations to coexist
  2548 in the same context.  INCOMPATIBILITY.
  2549 
  2550 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2551 primitive that also works in a locale context (both for constants and
  2552 fixed variables). Type declaration and internal syntactic representation
  2553 of given constants retrieved from the context. Likewise, the
  2554 'no_notation' command allows to remove given syntax annotations from the
  2555 current context.
  2556 
  2557 * Isar/locales: new derived specification elements 'axiomatization',
  2558 'definition', 'abbreviation', which support type-inference, admit
  2559 object-level specifications (equality, equivalence).  See also the
  2560 isar-ref manual.  Examples:
  2561 
  2562   axiomatization
  2563     eq  (infix "===" 50) where
  2564     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2565 
  2566   definition "f x y = x + y + 1"
  2567   definition g where "g x = f x x"
  2568 
  2569   abbreviation
  2570     neq  (infix "=!=" 50) where
  2571     "x =!= y == ~ (x === y)"
  2572 
  2573 These specifications may be also used in a locale context.  Then the
  2574 constants being introduced depend on certain fixed parameters, and the
  2575 constant name is qualified by the locale base name.  An internal
  2576 abbreviation takes care for convenient input and output, making the
  2577 parameters implicit and using the original short name.  See also
  2578 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2579 entities from a monomorphic theory.
  2580 
  2581 Presently, abbreviations are only available 'in' a target locale, but
  2582 not inherited by general import expressions.  Also note that
  2583 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2584 'translations' in common applications.  The "no_abbrevs" print mode
  2585 prevents folding of abbreviations in term output.
  2586 
  2587 Concrete syntax is attached to specified constants in internal form,
  2588 independently of name spaces.  The parse tree representation is
  2589 slightly different -- use 'notation' instead of raw 'syntax', and
  2590 'translations' with explicit "CONST" markup to accommodate this.
  2591 
  2592 * Pure/Isar: unified syntax for new-style specification mechanisms
  2593 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2594 full type inference and dummy patterns ("_").  For example:
  2595 
  2596   definition "K x _ = x"
  2597 
  2598   inductive conj for A B
  2599   where "A ==> B ==> conj A B"
  2600 
  2601 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2602 the current context.  Print mode "no_abbrevs" prevents inversion of
  2603 abbreviations on output.
  2604 
  2605 * Isar/locales: improved parameter handling: use of locales "var" and
  2606 "struct" no longer necessary; - parameter renamings are no longer
  2607 required to be injective.  For example, this allows to define
  2608 endomorphisms as locale endom = homom mult mult h.
  2609 
  2610 * Isar/locales: changed the way locales with predicates are defined.
  2611 Instead of accumulating the specification, the imported expression is
  2612 now an interpretation.  INCOMPATIBILITY: different normal form of
  2613 locale expressions.  In particular, in interpretations of locales with
  2614 predicates, goals repesenting already interpreted fragments are not
  2615 removed automatically.  Use methods `intro_locales' and
  2616 `unfold_locales'; see below.
  2617 
  2618 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2619 provide backward reasoning on locales predicates.  The methods are
  2620 aware of interpretations and discharge corresponding goals.
  2621 `intro_locales' is less aggressive then `unfold_locales' and does not
  2622 unfold predicates to assumptions.
  2623 
  2624 * Isar/locales: the order in which locale fragments are accumulated
  2625 has changed.  This enables to override declarations from fragments due
  2626 to interpretations -- for example, unwanted simp rules.
  2627 
  2628 * Isar/locales: interpretation in theories and proof contexts has been
  2629 extended.  One may now specify (and prove) equations, which are
  2630 unfolded in interpreted theorems.  This is useful for replacing
  2631 defined concepts (constants depending on locale parameters) by
  2632 concepts already existing in the target context.  Example:
  2633 
  2634   interpretation partial_order ["op <= :: [int, int] => bool"]
  2635     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2636 
  2637 Typically, the constant `partial_order.less' is created by a
  2638 definition specification element in the context of locale
  2639 partial_order.
  2640 
  2641 * Method "induct": improved internal context management to support
  2642 local fixes and defines on-the-fly. Thus explicit meta-level
  2643 connectives !!  and ==> are rarely required anymore in inductive goals
  2644 (using object-logic connectives for this purpose has been long
  2645 obsolete anyway). Common proof patterns are explained in
  2646 src/HOL/Induct/Common_Patterns.thy, see also
  2647 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2648 examples.
  2649 
  2650 * Method "induct": improved handling of simultaneous goals. Instead of
  2651 introducing object-level conjunction, the statement is now split into
  2652 several conclusions, while the corresponding symbolic cases are nested
  2653 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2654 see src/HOL/Induct/Common_Patterns.thy, for example.
  2655 
  2656 * Method "induct": mutual induction rules are now specified as a list
  2657 of rule sharing the same induction cases. HOL packages usually provide
  2658 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2659 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2660 mutual induction rules differently, i.e. like this:
  2661 
  2662   (induct rule: foo_bar.inducts)
  2663   (induct set: foo bar)
  2664   (induct pred: foo bar)
  2665   (induct type: foo bar)
  2666 
  2667 The ML function ProjectRule.projections turns old-style rules into the
  2668 new format.
  2669 
  2670 * Method "coinduct": dual of induction, see
  2671 src/HOL/Library/Coinductive_List.thy for various examples.
  2672 
  2673 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2674 considered a legacy feature.
  2675 
  2676 * Attribute "symmetric" produces result with standardized schematic
  2677 variables (index 0).  Potential INCOMPATIBILITY.
  2678 
  2679 * Simplifier: by default the simplifier trace only shows top level
  2680 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2681 default. Thus there is less danger of being flooded by the trace. The
  2682 trace indicates where parts have been suppressed.
  2683   
  2684 * Provers/classical: removed obsolete classical version of elim_format
  2685 attribute; classical elim/dest rules are now treated uniformly when
  2686 manipulating the claset.
  2687 
  2688 * Provers/classical: stricter checks to ensure that supplied intro,
  2689 dest and elim rules are well-formed; dest and elim rules must have at
  2690 least one premise.
  2691 
  2692 * Provers/classical: attributes dest/elim/intro take an optional
  2693 weight argument for the rule (just as the Pure versions).  Weights are
  2694 ignored by automated tools, but determine the search order of single
  2695 rule steps.
  2696 
  2697 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2698 where the body does not mention the bound variable.  Note that dummy
  2699 patterns implicitly depend on their context of bounds, which makes
  2700 "{_. _}" match any set comprehension as expected.  Potential
  2701 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2702 constant "_idtdummy" in the binding position.
  2703 
  2704 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2705 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2706 for example "A -> B" => "Pi A (%_. B)".
  2707 
  2708 * Pure: 'class_deps' command visualizes the subclass relation, using
  2709 the graph browser tool.
  2710 
  2711 * Pure: 'print_theory' now suppresses certain internal declarations by
  2712 default; use '!' option for full details.
  2713 
  2714 
  2715 *** HOL ***
  2716 
  2717 * Method "metis" proves goals by applying the Metis general-purpose
  2718 resolution prover (see also http://gilith.com/software/metis/).
  2719 Examples are in the directory MetisExamples.  WARNING: the
  2720 Isabelle/HOL-Metis integration does not yet work properly with
  2721 multi-threading.
  2722   
  2723 * Command 'sledgehammer' invokes external automatic theorem provers as
  2724 background processes.  It generates calls to the "metis" method if
  2725 successful. These can be pasted into the proof.  Users do not have to
  2726 wait for the automatic provers to return.  WARNING: does not really
  2727 work with multi-threading.
  2728 
  2729 * New "auto_quickcheck" feature tests outermost goal statements for
  2730 potential counter-examples.  Controlled by ML references
  2731 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2732 5000 milliseconds).  Fails silently if statements is outside of
  2733 executable fragment, or any other codgenerator problem occurs.
  2734 
  2735 * New constant "undefined" with axiom "undefined x = undefined".
  2736 
  2737 * Added class "HOL.eq", allowing for code generation with polymorphic
  2738 equality.
  2739 
  2740 * Some renaming of class constants due to canonical name prefixing in
  2741 the new 'class' package:
  2742 
  2743     HOL.abs ~> HOL.abs_class.abs
  2744     HOL.divide ~> HOL.divide_class.divide
  2745     0 ~> HOL.zero_class.zero
  2746     1 ~> HOL.one_class.one
  2747     op + ~> HOL.plus_class.plus
  2748     op - ~> HOL.minus_class.minus
  2749     uminus ~> HOL.minus_class.uminus
  2750     op * ~> HOL.times_class.times
  2751     op < ~> HOL.ord_class.less
  2752     op <= > HOL.ord_class.less_eq
  2753     Nat.power ~> Power.power_class.power
  2754     Nat.size ~> Nat.size_class.size
  2755     Numeral.number_of ~> Numeral.number_class.number_of
  2756     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2757     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2758     Orderings.min ~> Orderings.ord_class.min
  2759     Orderings.max ~> Orderings.ord_class.max
  2760     Divides.op div ~> Divides.div_class.div
  2761     Divides.op mod ~> Divides.div_class.mod
  2762     Divides.op dvd ~> Divides.div_class.dvd
  2763 
  2764 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2765 
  2766 a) User-defined constants using any of the names "plus", "minus",
  2767 "times", "less" or "less_eq". The standard syntax translations for
  2768 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2769 names.
  2770 
  2771 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2772 INCOMPATIBILITY: use more specific names.
  2773 
  2774 c) Permutative equations (e.g. "a + b = b + a")
  2775 Since the change of names also changes the order of terms, permutative
  2776 rewrite rules may get applied in a different order. Experience shows
  2777 that this is rarely the case (only two adaptions in the whole Isabelle
  2778 distribution).  INCOMPATIBILITY: rewrite proofs
  2779 
  2780 d) ML code directly refering to constant names
  2781 This in general only affects hand-written proof tactics, simprocs and
  2782 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2783 Consider using @{const_name} antiquotation.
  2784 
  2785 * New class "default" with associated constant "default".
  2786 
  2787 * Function "sgn" is now overloaded and available on int, real, complex
  2788 (and other numeric types), using class "sgn".  Two possible defs of
  2789 sgn are given as equational assumptions in the classes sgn_if and
  2790 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2791 INCOMPATIBILITY.
  2792 
  2793 * Locale "partial_order" now unified with class "order" (cf. theory
  2794 Orderings), added parameter "less".  INCOMPATIBILITY.
  2795 
  2796 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2797 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2798 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2799 
  2800 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2801 changed order of proof goals in instance proofs.
  2802 
  2803 * The transitivity reasoner for partial and linear orders is set up
  2804 for classes "order" and "linorder".  Instances of the reasoner are available
  2805 in all contexts importing or interpreting the corresponding locales.
  2806 Method "order" invokes the reasoner separately; the reasoner
  2807 is also integrated with the Simplifier as a solver.  Diagnostic
  2808 command 'print_orders' shows the available instances of the reasoner
  2809 in the current context.
  2810 
  2811 * Localized monotonicity predicate in theory "Orderings"; integrated
  2812 lemmas max_of_mono and min_of_mono with this predicate.
  2813 INCOMPATIBILITY.
  2814 
  2815 * Formulation of theorem "dense" changed slightly due to integration
  2816 with new class dense_linear_order.
  2817 
  2818 * Uniform lattice theory development in HOL.
  2819 
  2820     constants "meet" and "join" now named "inf" and "sup"
  2821     constant "Meet" now named "Inf"
  2822 
  2823     classes "meet_semilorder" and "join_semilorder" now named
  2824       "lower_semilattice" and "upper_semilattice"
  2825     class "lorder" now named "lattice"
  2826     class "comp_lat" now named "complete_lattice"
  2827 
  2828     Instantiation of lattice classes allows explicit definitions
  2829     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2830 
  2831   INCOMPATIBILITY.  Theorem renames:
  2832 
  2833     meet_left_le            ~> inf_le1
  2834     meet_right_le           ~> inf_le2
  2835     join_left_le            ~> sup_ge1
  2836     join_right_le           ~> sup_ge2
  2837     meet_join_le            ~> inf_sup_ord
  2838     le_meetI                ~> le_infI
  2839     join_leI                ~> le_supI
  2840     le_meet                 ~> le_inf_iff
  2841     le_join                 ~> ge_sup_conv
  2842     meet_idempotent         ~> inf_idem
  2843     join_idempotent         ~> sup_idem
  2844     meet_comm               ~> inf_commute
  2845     join_comm               ~> sup_commute
  2846     meet_leI1               ~> le_infI1
  2847     meet_leI2               ~> le_infI2
  2848     le_joinI1               ~> le_supI1
  2849     le_joinI2               ~> le_supI2
  2850     meet_assoc              ~> inf_assoc
  2851     join_assoc              ~> sup_assoc
  2852     meet_left_comm          ~> inf_left_commute
  2853     meet_left_idempotent    ~> inf_left_idem
  2854     join_left_comm          ~> sup_left_commute
  2855     join_left_idempotent    ~> sup_left_idem
  2856     meet_aci                ~> inf_aci
  2857     join_aci                ~> sup_aci
  2858     le_def_meet             ~> le_iff_inf
  2859     le_def_join             ~> le_iff_sup
  2860     join_absorp2            ~> sup_absorb2
  2861     join_absorp1            ~> sup_absorb1
  2862     meet_absorp1            ~> inf_absorb1
  2863     meet_absorp2            ~> inf_absorb2
  2864     meet_join_absorp        ~> inf_sup_absorb
  2865     join_meet_absorp        ~> sup_inf_absorb
  2866     distrib_join_le         ~> distrib_sup_le
  2867     distrib_meet_le         ~> distrib_inf_le
  2868 
  2869     add_meet_distrib_left   ~> add_inf_distrib_left
  2870     add_join_distrib_left   ~> add_sup_distrib_left
  2871     is_join_neg_meet        ~> is_join_neg_inf
  2872     is_meet_neg_join        ~> is_meet_neg_sup
  2873     add_meet_distrib_right  ~> add_inf_distrib_right
  2874     add_join_distrib_right  ~> add_sup_distrib_right
  2875     add_meet_join_distribs  ~> add_sup_inf_distribs
  2876     join_eq_neg_meet        ~> sup_eq_neg_inf
  2877     meet_eq_neg_join        ~> inf_eq_neg_sup
  2878     add_eq_meet_join        ~> add_eq_inf_sup
  2879     meet_0_imp_0            ~> inf_0_imp_0
  2880     join_0_imp_0            ~> sup_0_imp_0
  2881     meet_0_eq_0             ~> inf_0_eq_0
  2882     join_0_eq_0             ~> sup_0_eq_0
  2883     neg_meet_eq_join        ~> neg_inf_eq_sup
  2884     neg_join_eq_meet        ~> neg_sup_eq_inf
  2885     join_eq_if              ~> sup_eq_if
  2886 
  2887     mono_meet               ~> mono_inf
  2888     mono_join               ~> mono_sup
  2889     meet_bool_eq            ~> inf_bool_eq
  2890     join_bool_eq            ~> sup_bool_eq
  2891     meet_fun_eq             ~> inf_fun_eq
  2892     join_fun_eq             ~> sup_fun_eq
  2893     meet_set_eq             ~> inf_set_eq
  2894     join_set_eq             ~> sup_set_eq
  2895     meet1_iff               ~> inf1_iff
  2896     meet2_iff               ~> inf2_iff
  2897     meet1I                  ~> inf1I
  2898     meet2I                  ~> inf2I
  2899     meet1D1                 ~> inf1D1
  2900     meet2D1                 ~> inf2D1
  2901     meet1D2                 ~> inf1D2
  2902     meet2D2                 ~> inf2D2
  2903     meet1E                  ~> inf1E
  2904     meet2E                  ~> inf2E
  2905     join1_iff               ~> sup1_iff
  2906     join2_iff               ~> sup2_iff
  2907     join1I1                 ~> sup1I1
  2908     join2I1                 ~> sup2I1
  2909     join1I1                 ~> sup1I1
  2910     join2I2                 ~> sup1I2
  2911     join1CI                 ~> sup1CI
  2912     join2CI                 ~> sup2CI
  2913     join1E                  ~> sup1E
  2914     join2E                  ~> sup2E
  2915 
  2916     is_meet_Meet            ~> is_meet_Inf
  2917     Meet_bool_def           ~> Inf_bool_def
  2918     Meet_fun_def            ~> Inf_fun_def
  2919     Meet_greatest           ~> Inf_greatest
  2920     Meet_lower              ~> Inf_lower
  2921     Meet_set_def            ~> Inf_set_def
  2922 
  2923     Sup_def                 ~> Sup_Inf
  2924     Sup_bool_eq             ~> Sup_bool_def
  2925     Sup_fun_eq              ~> Sup_fun_def
  2926     Sup_set_eq              ~> Sup_set_def
  2927 
  2928     listsp_meetI            ~> listsp_infI
  2929     listsp_meet_eq          ~> listsp_inf_eq
  2930 
  2931     meet_min                ~> inf_min
  2932     join_max                ~> sup_max
  2933 
  2934 * Added syntactic class "size"; overloaded constant "size" now has
  2935 type "'a::size ==> bool"
  2936 
  2937 * Internal reorganisation of `size' of datatypes: size theorems
  2938 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2939 simplification rules by default!); theorems "prod.size" now named
  2940 "*.size".
  2941 
  2942 * Class "div" now inherits from class "times" rather than "type".
  2943 INCOMPATIBILITY.
  2944 
  2945 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2946 Linorder etc.  have disappeared; operations defined in terms of
  2947 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2948 
  2949 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2950 
  2951 * HOL-Word: New extensive library and type for generic, fixed size
  2952 machine words, with arithemtic, bit-wise, shifting and rotating
  2953 operations, reflection into int, nat, and bool lists, automation for
  2954 linear arithmetic (by automatic reflection into nat or int), including
  2955 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2956 arithmetic type classes, supporting automatic simplification of
  2957 numerals on all operations.
  2958 
  2959 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2960 
  2961 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2962 
  2963 * Code generator library theories:
  2964   - Code_Integer represents HOL integers by big integer literals in target
  2965     languages.
  2966   - Code_Char represents HOL characters by character literals in target
  2967     languages.
  2968   - Code_Char_chr like Code_Char, but also offers treatment of character
  2969     codes; includes Code_Integer.
  2970   - Executable_Set allows to generate code for finite sets using lists.
  2971   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2972     denominator).
  2973   - Executable_Real implements a subset of real numbers, namly those
  2974     representable by rational numbers.
  2975   - Efficient_Nat implements natural numbers by integers, which in general will
  2976     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2977     includes Code_Integer.
  2978   - Code_Index provides an additional datatype index which is mapped to
  2979     target-language built-in integers.
  2980   - Code_Message provides an additional datatype message_string which is isomorphic to
  2981     strings; messages are mapped to target-language strings.
  2982 
  2983 * New package for inductive predicates
  2984 
  2985   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2986 
  2987     inductive
  2988       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2989       for z_1 :: U_1 and ... and z_n :: U_m
  2990     where
  2991       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2992     | ...
  2993 
  2994   with full support for type-inference, rather than
  2995 
  2996     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2997 
  2998     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2999     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3000 
  3001     inductive "s z_1 ... z_m"
  3002     intros
  3003       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3004       ...
  3005 
  3006   For backward compatibility, there is a wrapper allowing inductive
  3007   sets to be defined with the new package via
  3008 
  3009     inductive_set
  3010       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3011       for z_1 :: U_1 and ... and z_n :: U_m
  3012     where
  3013       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3014     | ...
  3015 
  3016   or
  3017 
  3018     inductive_set
  3019       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3020       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3021       for z_1 :: U_1 and ... and z_n :: U_m
  3022     where
  3023       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3024     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3025     | ...
  3026 
  3027   if the additional syntax "p ..." is required.
  3028 
  3029   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3030   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3031 
  3032   INCOMPATIBILITIES:
  3033 
  3034   - Since declaration and definition of inductive sets or predicates
  3035     is no longer separated, abbreviations involving the newly
  3036     introduced sets or predicates must be specified together with the
  3037     introduction rules after the 'where' keyword (see above), rather
  3038     than before the actual inductive definition.
  3039 
  3040   - The variables in induction and elimination rules are now
  3041     quantified in the order of their occurrence in the introduction
  3042     rules, rather than in alphabetical order. Since this may break
  3043     some proofs, these proofs either have to be repaired, e.g. by
  3044     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3045     statements of the form
  3046 
  3047       case (rule_i a_i_1 ... a_i_{k_i})
  3048 
  3049     or the old order of quantification has to be restored by explicitly adding
  3050     meta-level quantifiers in the introduction rules, i.e.
  3051 
  3052       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3053 
  3054   - The format of the elimination rules is now
  3055 
  3056       p z_1 ... z_m x_1 ... x_n ==>
  3057         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3058         ==> ... ==> P
  3059 
  3060     for predicates and
  3061 
  3062       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3063         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3064         ==> ... ==> P
  3065 
  3066     for sets rather than
  3067 
  3068       x : s z_1 ... z_m ==>
  3069         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3070         ==> ... ==> P
  3071 
  3072     This may require terms in goals to be expanded to n-tuples
  3073     (e.g. using case_tac or simplification with the split_paired_all
  3074     rule) before the above elimination rule is applicable.
  3075 
  3076   - The elimination or case analysis rules for (mutually) inductive
  3077     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3078     list of rules "p_1_..._p_k.elims" is no longer available.
  3079 
  3080 * New package "function"/"fun" for general recursive functions,
  3081 supporting mutual and nested recursion, definitions in local contexts,
  3082 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3083 for small examples, and the separate tutorial on the function
  3084 package. The old recdef "package" is still available as before, but
  3085 users are encouraged to use the new package.
  3086 
  3087 * Method "lexicographic_order" automatically synthesizes termination
  3088 relations as lexicographic combinations of size measures. 
  3089 
  3090 * Case-expressions allow arbitrary constructor-patterns (including
  3091 "_") and take their order into account, like in functional
  3092 programming.  Internally, this is translated into nested
  3093 case-expressions; missing cases are added and mapped to the predefined
  3094 constant "undefined". In complicated cases printing may no longer show
  3095 the original input but the internal form. Lambda-abstractions allow
  3096 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3097 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3098 variable.
  3099 
  3100 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3101 is an abbreviation for "of_nat :: nat => int". The simplification
  3102 rules for "of_nat" have been changed to work like "int" did
  3103 previously.  Potential INCOMPATIBILITY:
  3104   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3105   - of_nat_diff and of_nat_mult are no longer default simp rules
  3106 
  3107 * Method "algebra" solves polynomial equations over (semi)rings using
  3108 Groebner bases. The (semi)ring structure is defined by locales and the
  3109 tool setup depends on that generic context. Installing the method for
  3110 a specific type involves instantiating the locale and possibly adding
  3111 declarations for computation on the coefficients.  The method is
  3112 already instantiated for natural numbers and for the axiomatic class
  3113 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3114 CALCULEMUS 2007 for the general principles underlying this
  3115 architecture of context-aware proof-tools.
  3116 
  3117 * Method "ferrack" implements quantifier elimination over
  3118 special-purpose dense linear orders using locales (analogous to
  3119 "algebra"). The method is already installed for class
  3120 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3121 rat, etc.
  3122 
  3123 * Former constant "List.op @" now named "List.append".  Use ML
  3124 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3125 circumvent possible incompatibilities when working on ML level.
  3126 
  3127 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3128 
  3129 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3130 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3131 
  3132 * New syntax for Haskell-like list comprehension (input only), eg.
  3133 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3134 
  3135 * The special syntax for function "filter" has changed from [x :
  3136 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3137 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3138 
  3139 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3140 defined on nat only, as an abbreviation for [a..<Suc b]
  3141 INCOMPATIBILITY.
  3142 
  3143 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3144 
  3145 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3146 
  3147 * New lemma collection field_simps (an extension of ring_simps) for
  3148 manipulating (in)equations involving division. Multiplies with all
  3149 denominators that can be proved to be non-zero (in equations) or
  3150 positive/negative (in inequations).
  3151 
  3152 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3153 have been improved and renamed to ring_simps, group_simps and
  3154 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3155 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3156 
  3157 * Theory Library/Commutative_Ring: switched from recdef to function
  3158 package; constants add, mul, pow now curried.  Infix syntax for
  3159 algebraic operations.
  3160 
  3161 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3162 INCOMPATIBILITY.
  3163 
  3164 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3165 INCOMPATIBILITY.
  3166 
  3167 * HOL/records: generalised field-update to take a function on the
  3168 field rather than the new value: r(|A := x|) is translated to A_update
  3169 (K x) r The K-combinator that is internally used is called K_record.
  3170 INCOMPATIBILITY: Usage of the plain update functions has to be
  3171 adapted.
  3172  
  3173 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3174 * x = 0, which are required for a semiring.  Richer structures do not
  3175 inherit from semiring_0 anymore, because this property is a theorem
  3176 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3177 there is more to prove, but this is mostly trivial.
  3178 
  3179 * Class "recpower" is generalized to arbitrary monoids, not just
  3180 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3181 commutativity or semiring properties additionally.
  3182 
  3183 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3184 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3185 better use 'abbreviation'.
  3186 
  3187 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3188 
  3189 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3190 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3191 significant changes for setting up numeral syntax for types:
  3192   - New constants Numeral.pred and Numeral.succ instead
  3193       of former Numeral.bin_pred and Numeral.bin_succ.
  3194   - Use integer operations instead of bin_add, bin_mult and so on.
  3195   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3196   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3197 
  3198 See src/HOL/Integ/IntArith.thy for an example setup.
  3199 
  3200 * Command 'normal_form' computes the normal form of a term that may
  3201 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3202 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3203 heavy-duty computations because the functions are compiled to ML
  3204 first.  Correspondingly, a method "normalization" is provided.  See
  3205 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3206 
  3207 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3208 25 like -->); output depends on the "iff" print_mode, the default is
  3209 "A = B" (with priority 50).
  3210 
  3211 * Relations less (<) and less_eq (<=) are also available on type bool.
  3212 Modified syntax to disallow nesting without explicit parentheses,
  3213 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3214 INCOMPATIBILITY.
  3215 
  3216 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3217 
  3218 * Relation composition operator "op O" now has precedence 75 and binds
  3219 stronger than union and intersection. INCOMPATIBILITY.
  3220 
  3221 * The old set interval syntax "{m..n(}" (and relatives) has been
  3222 removed.  Use "{m..<n}" (and relatives) instead.
  3223 
  3224 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3225 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3226 ``declare [[simproc del: neq]]''.
  3227 
  3228 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3229 True/False.
  3230 
  3231 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3232 
  3233 * Theorem setsum_mult renamed to setsum_right_distrib.
  3234 
  3235 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3236 ``rule'' method.
  3237 
  3238 * Reimplemented methods "sat" and "satx", with several improvements:
  3239 goals no longer need to be stated as "<prems> ==> False", equivalences
  3240 (i.e. "=" on type bool) are handled, variable names of the form
  3241 "lit_<n>" are no longer reserved, significant speedup.
  3242 
  3243 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3244 zChaff is still supported as well.
  3245 
  3246 * 'inductive' and 'datatype': provide projections of mutual rules,
  3247 bundled as foo_bar.inducts;
  3248 
  3249 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3250 Library.
  3251 
  3252 * Library: moved theory Accessible_Part to main HOL.
  3253 
  3254 * Library: added theory Coinductive_List of potentially infinite lists
  3255 as greatest fixed-point.
  3256 
  3257 * Library: added theory AssocList which implements (finite) maps as
  3258 association lists.
  3259 
  3260 * Method "evaluation" solves goals (i.e. a boolean expression)
  3261 efficiently by compiling it to ML.  The goal is "proved" (via an
  3262 oracle) if it evaluates to True.
  3263 
  3264 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3265 also when invoked by the simplifier.  This results in the Simplifier
  3266 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3267 Configuration option fast_arith_split_limit=0 recovers the old
  3268 behavior.
  3269 
  3270 * Support for hex (0x20) and binary (0b1001) numerals.
  3271 
  3272 * New method: reify eqs (t), where eqs are equations for an
  3273 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3274 parameter, computes a term s::'b and a list xs::'a list and proves the
  3275 theorem I xs s = t. This is also known as reification or quoting. The
  3276 resulting theorem is applied to the subgoal to substitute t with I xs
  3277 s.  If t is omitted, the subgoal itself is reified.
  3278 
  3279 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3280 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3281 where f is supposed to be a computable function (in the sense of code
  3282 generattion). The method uses reify to compute s and xs as above then
  3283 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3284 r and finally gets the theorem t = r, which is again applied to the
  3285 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3286 
  3287 * Reflection: Automatic reification now handels binding, an example is
  3288 available in src/HOL/ex/ReflectionEx.thy
  3289 
  3290 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3291 command 'statespace' that is similar to 'record', but introduces an
  3292 abstract specification based on the locale infrastructure instead of
  3293 HOL types.  This leads to extra flexibility in composing state spaces,
  3294 in particular multiple inheritance and renaming of components.
  3295 
  3296 
  3297 *** HOL-Complex ***
  3298 
  3299 * Hyperreal: Functions root and sqrt are now defined on negative real
  3300 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3301 Nonnegativity side conditions have been removed from many lemmas, so
  3302 that more subgoals may now be solved by simplification; potential
  3303 INCOMPATIBILITY.
  3304 
  3305 * Real: new type classes formalize real normed vector spaces and
  3306 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3307 and norm :: 'a => real.
  3308 
  3309 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3310 reals into other types. The overloaded constant Reals :: 'a set is now
  3311 defined as range of_real; potential INCOMPATIBILITY.
  3312 
  3313 * Real: proper support for ML code generation, including 'quickcheck'.
  3314 Reals are implemented as arbitrary precision rationals.
  3315 
  3316 * Hyperreal: Several constants that previously worked only for the
  3317 reals have been generalized, so they now work over arbitrary vector
  3318 spaces. Type annotations may need to be added in some cases; potential
  3319 INCOMPATIBILITY.
  3320 
  3321   Infinitesimal  :: ('a::real_normed_vector) star set
  3322   HFinite        :: ('a::real_normed_vector) star set
  3323   HInfinite      :: ('a::real_normed_vector) star set
  3324   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3325   monad          :: ('a::real_normed_vector) star => 'a star set
  3326   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3327   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3328   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3329   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3330   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3331   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3332   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3333   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3334   sgn            :: 'a::real_normed_vector => 'a
  3335   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3336 
  3337 * Complex: Some complex-specific constants are now abbreviations for
  3338 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3339 hnorm.  Other constants have been entirely removed in favor of the
  3340 polymorphic versions (INCOMPATIBILITY):
  3341 
  3342   approx        <-- capprox
  3343   HFinite       <-- CFinite
  3344   HInfinite     <-- CInfinite
  3345   Infinitesimal <-- CInfinitesimal
  3346   monad         <-- cmonad
  3347   galaxy        <-- cgalaxy
  3348   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3349   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3350   (ns)deriv     <-- (ns)cderiv
  3351 
  3352 
  3353 *** HOL-Algebra ***
  3354 
  3355 * Formalisation of ideals and the quotient construction over rings.
  3356 
  3357 * Order and lattice theory no longer based on records.
  3358 INCOMPATIBILITY.
  3359 
  3360 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3361 greatest_closed.  INCOMPATIBILITY.
  3362 
  3363 * Method algebra is now set up via an attribute.  For examples see
  3364 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3365 of algebraic structures.
  3366 
  3367 * Renamed theory CRing to Ring.
  3368 
  3369 
  3370 *** HOL-Nominal ***
  3371 
  3372 * Substantial, yet incomplete support for nominal datatypes (binding
  3373 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3374 src/HOL/Nominal/Examples.  Prospective users should consult
  3375 http://isabelle.in.tum.de/nominal/
  3376 
  3377 
  3378 *** ML ***
  3379 
  3380 * ML basics: just one true type int, which coincides with IntInf.int
  3381 (even on SML/NJ).
  3382 
  3383 * ML within Isar: antiquotations allow to embed statically-checked
  3384 formal entities in the source, referring to the context available at
  3385 compile-time.  For example:
  3386 
  3387 ML {* @{sort "{zero,one}"} *}
  3388 ML {* @{typ "'a => 'b"} *}
  3389 ML {* @{term "%x. x"} *}
  3390 ML {* @{prop "x == y"} *}
  3391 ML {* @{ctyp "'a => 'b"} *}
  3392 ML {* @{cterm "%x. x"} *}
  3393 ML {* @{cprop "x == y"} *}
  3394 ML {* @{thm asm_rl} *}
  3395 ML {* @{thms asm_rl} *}
  3396 ML {* @{type_name c} *}
  3397 ML {* @{type_syntax c} *}
  3398 ML {* @{const_name c} *}
  3399 ML {* @{const_syntax c} *}
  3400 ML {* @{context} *}
  3401 ML {* @{theory} *}
  3402 ML {* @{theory Pure} *}
  3403 ML {* @{theory_ref} *}
  3404 ML {* @{theory_ref Pure} *}
  3405 ML {* @{simpset} *}
  3406 ML {* @{claset} *}
  3407 ML {* @{clasimpset} *}
  3408 
  3409 The same works for sources being ``used'' within an Isar context.
  3410 
  3411 * ML in Isar: improved error reporting; extra verbosity with
  3412 ML_Context.trace enabled.
  3413 
  3414 * Pure/General/table.ML: the join operations now works via exceptions
  3415 DUP/SAME instead of type option. This is simpler in simple cases, and
  3416 admits slightly more efficient complex applications.
  3417 
  3418 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3419 use Context.generic instead of just theory.
  3420 
  3421 * Pure: datatype Context.generic joins theory/Proof.context and
  3422 provides some facilities for code that works in either kind of
  3423 context, notably GenericDataFun for uniform theory and proof data.
  3424 
  3425 * Pure: simplified internal attribute type, which is now always
  3426 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3427 local (Proof.context) attributes have been discontinued, while
  3428 minimizing code duplication. Thm.rule_attribute and
  3429 Thm.declaration_attribute build canonical attributes; see also structure
  3430 Context for further operations on Context.generic, notably
  3431 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3432 declarations and definitions.
  3433 
  3434 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3435 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3436 init only required for impure data. INCOMPATIBILITY: empty really need
  3437 to be empty (no dependencies on theory content!)
  3438 
  3439 * Pure/kernel: consts certification ignores sort constraints given in
  3440 signature declarations. (This information is not relevant to the
  3441 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3442 potential INCOMPATIBILITY.
  3443 
  3444 * Pure: axiomatic type classes are now purely definitional, with
  3445 explicit proofs of class axioms and super class relations performed
  3446 internally. See Pure/axclass.ML for the main internal interfaces --
  3447 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3448 AxClass.axiomatize_class/classrel/arity supersede
  3449 Sign.add_classes/classrel/arities.
  3450 
  3451 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3452 global/local versions on theory vs. Proof.context have been
  3453 discontinued; Attrib.syntax and Method.syntax have been adapted
  3454 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3455 attributes, methods, etc.
  3456 
  3457 * Pure: several functions of signature "... -> theory -> theory * ..."
  3458 have been reoriented to "... -> theory -> ... * theory" in order to
  3459 allow natural usage in combination with the ||>, ||>>, |-> and
  3460 fold_map combinators.
  3461 
  3462 * Pure: official theorem names (closed derivations) and additional
  3463 comments (tags) are now strictly separate.  Name hints -- which are
  3464 maintained as tags -- may be attached any time without affecting the
  3465 derivation.
  3466 
  3467 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3468 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3469 achieve the old behaviour.
  3470 
  3471 * Pure: the "Goal" constant is now called "prop", supporting a
  3472 slightly more general idea of ``protecting'' meta-level rule
  3473 statements.
  3474 
  3475 * Pure: Logic.(un)varify only works in a global context, which is now
  3476 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3477 Logic.legacy_(un)varify as temporary workaround.
  3478 
  3479 * Pure: structure Name provides scalable operations for generating
  3480 internal variable names, notably Name.variants etc.  This replaces
  3481 some popular functions from term.ML:
  3482 
  3483   Term.variant		->  Name.variant
  3484   Term.variantlist	->  Name.variant_list
  3485   Term.invent_names	->  Name.invent_list
  3486 
  3487 Note that low-level renaming rarely occurs in new code -- operations
  3488 from structure Variable are used instead (see below).
  3489 
  3490 * Pure: structure Variable provides fundamental operations for proper
  3491 treatment of fixed/schematic variables in a context.  For example,
  3492 Variable.import introduces fixes for schematics of given facts and
  3493 Variable.export reverses the effect (up to renaming) -- this replaces
  3494 various freeze_thaw operations.
  3495 
  3496 * Pure: structure Goal provides simple interfaces for
  3497 init/conclude/finish and tactical prove operations (replacing former
  3498 Tactic.prove).  Goal.prove is the canonical way to prove results
  3499 within a given context; Goal.prove_global is a degraded version for
  3500 theory level goals, including a global Drule.standard.  Note that
  3501 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3502 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3503 in a locale context).
  3504 
  3505 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3506 and type checking (Syntax.check_term etc.), with common combinations
  3507 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3508 which are considered legacy and await removal.
  3509 
  3510 * Pure/Syntax: generic interfaces for type unchecking
  3511 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3512 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3513 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3514 available for convenience, but refer to the very same operations using
  3515 a mere theory instead of a full context.
  3516 
  3517 * Isar: simplified treatment of user-level errors, using exception
  3518 ERROR of string uniformly.  Function error now merely raises ERROR,
  3519 without any side effect on output channels.  The Isar toplevel takes
  3520 care of proper display of ERROR exceptions.  ML code may use plain
  3521 handle/can/try; cat_error may be used to concatenate errors like this:
  3522 
  3523   ... handle ERROR msg => cat_error msg "..."
  3524 
  3525 Toplevel ML code (run directly or through the Isar toplevel) may be
  3526 embedded into the Isar toplevel with exception display/debug like
  3527 this:
  3528 
  3529   Isar.toplevel (fn () => ...)
  3530 
  3531 INCOMPATIBILITY, removed special transform_error facilities, removed
  3532 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3533 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3534 -- use plain ERROR instead.
  3535 
  3536 * Isar: theory setup now has type (theory -> theory), instead of a
  3537 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3538 
  3539 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3540 ProofContext.debug/verbose flags.
  3541 
  3542 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3543 theory before entering a proof state.  Transactions now always see a
  3544 quasi-functional intermediate checkpoint, both in interactive and
  3545 batch mode.
  3546 
  3547 * Isar: simplified interfaces for outer syntax.  Renamed
  3548 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3549 OuterSyntax.add_parsers -- this functionality is now included in
  3550 OuterSyntax.command etc.  INCOMPATIBILITY.
  3551 
  3552 * Simplifier: the simpset of a running simplification process now
  3553 contains a proof context (cf. Simplifier.the_context), which is the
  3554 very context that the initial simpset has been retrieved from (by
  3555 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3556 (solver, looper etc.) may depend on arbitrary proof data.
  3557 
  3558 * Simplifier.inherit_context inherits the proof context (plus the
  3559 local bounds) of the current simplification process; any simproc
  3560 etc. that calls the Simplifier recursively should do this!  Removed
  3561 former Simplifier.inherit_bounds, which is already included here --
  3562 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3563 specify an explicit context using Simplifier.context/theory_context.
  3564 
  3565 * Simplifier/Classical Reasoner: more abstract interfaces
  3566 change_simpset/claset for modifying the simpset/claset reference of a
  3567 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3568 INCOMPATIBILITY.
  3569 
  3570 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3571 "Trueprop" etc.
  3572 
  3573 
  3574 *** System ***
  3575 
  3576 * settings: the default heap location within ISABELLE_HOME_USER now
  3577 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3578 Isabelle installations.
  3579 
  3580 * isabelle-process: option -S (secure mode) disables some critical
  3581 operations, notably runtime compilation and evaluation of ML source
  3582 code.
  3583 
  3584 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3585 
  3586 * Support for parallel execution, using native multicore support of
  3587 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3588 independent theories, according to the given theory header
  3589 specifications. The maximum number of worker threads is specified via
  3590 usedir option -M or the "max-threads" setting in Proof General. A
  3591 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3592 to 6 on a 8-core machine.  User-code needs to observe certain
  3593 guidelines for thread-safe programming, see appendix A in the Isar
  3594 Implementation manual.
  3595 
  3596 
  3597 
  3598 New in Isabelle2005 (October 2005)
  3599 ----------------------------------
  3600 
  3601 *** General ***
  3602 
  3603 * Theory headers: the new header syntax for Isar theories is
  3604 
  3605   theory <name>
  3606   imports <theory1> ... <theoryN>
  3607   uses <file1> ... <fileM>
  3608   begin
  3609 
  3610 where the 'uses' part is optional.  The previous syntax
  3611 
  3612   theory <name> = <theory1> + ... + <theoryN>:
  3613 
  3614 will disappear in the next release.  Use isatool fixheaders to convert
  3615 existing theory files.  Note that there is no change in ancient
  3616 non-Isar theories now, but these will disappear soon.
  3617 
  3618 * Theory loader: parent theories can now also be referred to via
  3619 relative and absolute paths.
  3620 
  3621 * Command 'find_theorems' searches for a list of criteria instead of a
  3622 list of constants. Known criteria are: intro, elim, dest, name:string,
  3623 simp:term, and any term. Criteria can be preceded by '-' to select
  3624 theorems that do not match. Intro, elim, dest select theorems that
  3625 match the current goal, name:s selects theorems whose fully qualified
  3626 name contain s, and simp:term selects all simplification rules whose
  3627 lhs match term.  Any other term is interpreted as pattern and selects
  3628 all theorems matching the pattern. Available in ProofGeneral under
  3629 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3630 
  3631   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3632 
  3633 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3634 matching the current goal as introduction rule and not having "HOL."
  3635 in their name (i.e. not being defined in theory HOL).
  3636 
  3637 * Command 'thms_containing' has been discontinued in favour of
  3638 'find_theorems'; INCOMPATIBILITY.
  3639 
  3640 * Communication with Proof General is now 8bit clean, which means that
  3641 Unicode text in UTF-8 encoding may be used within theory texts (both
  3642 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3643 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3644 
  3645   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3646   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3647 
  3648 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3649 Classical Reasoner.  Typical big applications run around 2 times
  3650 faster.
  3651 
  3652 
  3653 *** Document preparation ***
  3654 
  3655 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3656 of raw sources.  Only those symbols that do not require additional
  3657 LaTeX packages (depending on comments in isabellesym.sty) are
  3658 displayed properly, everything else is left verbatim.  isatool display
  3659 and isatool print are used as front ends (these are subject to the
  3660 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3661 
  3662 * Command tags control specific markup of certain regions of text,
  3663 notably folding and hiding.  Predefined tags include "theory" (for
  3664 theory begin and end), "proof" for proof commands, and "ML" for
  3665 commands involving ML code; the additional tags "visible" and
  3666 "invisible" are unused by default.  Users may give explicit tag
  3667 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3668 interpretation of tags is determined by the LaTeX job during document
  3669 preparation: see option -V of isatool usedir, or options -n and -t of
  3670 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3671 \isadroptag.
  3672 
  3673 Several document versions may be produced at the same time via isatool
  3674 usedir (the generated index.html will link all of them).  Typical
  3675 specifications include ''-V document=theory,proof,ML'' to present
  3676 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3677 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3678 these parts without any formal replacement text.  The Isabelle site
  3679 default settings produce ''document'' and ''outline'' versions as
  3680 specified above.
  3681 
  3682 * Several new antiquotations:
  3683 
  3684   @{term_type term} prints a term with its type annotated;
  3685 
  3686   @{typeof term} prints the type of a term;
  3687 
  3688   @{const const} is the same as @{term const}, but checks that the
  3689   argument is a known logical constant;
  3690 
  3691   @{term_style style term} and @{thm_style style thm} print a term or
  3692   theorem applying a "style" to it
  3693 
  3694   @{ML text}
  3695 
  3696 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3697 definitions, equations, inequations etc., 'concl' printing only the
  3698 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3699 to print the specified premise.  TermStyle.add_style provides an ML
  3700 interface for introducing further styles.  See also the "LaTeX Sugar"
  3701 document practical applications.  The ML antiquotation prints
  3702 type-checked ML expressions verbatim.
  3703 
  3704 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3705 and 'text' support optional locale specification '(in loc)', which
  3706 specifies the default context for interpreting antiquotations.  For
  3707 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3708 
  3709 * Option 'locale=NAME' of antiquotations specifies an alternative
  3710 context interpreting the subsequent argument.  For example: @{thm
  3711 [locale=lattice] inf_assoc}.
  3712 
  3713 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3714 a proof context.
  3715 
  3716 * Proper output of antiquotations for theory commands involving a
  3717 proof context (such as 'locale' or 'theorem (in loc) ...').
  3718 
  3719 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3720 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3721 
  3722 * isatool usedir: new option -C (default true) controls whether option
  3723 -D should include a copy of the original document directory; -C false
  3724 prevents unwanted effects such as copying of administrative CVS data.
  3725 
  3726 
  3727 *** Pure ***
  3728 
  3729 * Considerably improved version of 'constdefs' command.  Now performs
  3730 automatic type-inference of declared constants; additional support for
  3731 local structure declarations (cf. locales and HOL records), see also
  3732 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3733 sequential dependencies of definitions within a single 'constdefs'
  3734 section; moreover, the declared name needs to be an identifier.  If
  3735 all fails, consider to fall back on 'consts' and 'defs' separately.
  3736 
  3737 * Improved indexed syntax and implicit structures.  First of all,
  3738 indexed syntax provides a notational device for subscripted
  3739 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3740 expressions.  Secondly, in a local context with structure
  3741 declarations, number indexes \<^sub>n or the empty index (default
  3742 number 1) refer to a certain fixed variable implicitly; option
  3743 show_structs controls printing of implicit structures.  Typical
  3744 applications of these concepts involve record types and locales.
  3745 
  3746 * New command 'no_syntax' removes grammar declarations (and
  3747 translations) resulting from the given syntax specification, which is
  3748 interpreted in the same manner as for the 'syntax' command.
  3749 
  3750 * 'Advanced' translation functions (parse_translation etc.) may depend
  3751 on the signature of the theory context being presently used for
  3752 parsing/printing, see also isar-ref manual.
  3753 
  3754 * Improved 'oracle' command provides a type-safe interface to turn an
  3755 ML expression of type theory -> T -> term into a primitive rule of
  3756 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3757 is already included here); see also FOL/ex/IffExample.thy;
  3758 INCOMPATIBILITY.
  3759 
  3760 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3761 before); "cI" is no longer bound, use "c.intro" instead.
  3762 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3763 axclasses vs. locales.
  3764 
  3765 * Improved internal renaming of symbolic identifiers -- attach primes
  3766 instead of base 26 numbers.
  3767 
  3768 * New flag show_question_marks controls printing of leading question
  3769 marks in schematic variable names.
  3770 
  3771 * In schematic variable names, *any* symbol following \<^isub> or
  3772 \<^isup> is now treated as part of the base name.  For example, the
  3773 following works without printing of awkward ".0" indexes:
  3774 
  3775   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3776     by simp
  3777 
  3778 * Inner syntax includes (*(*nested*) comments*).
  3779 
  3780 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3781 annotations as "(00...)".
  3782 
  3783 * Clear separation of logical types and nonterminals, where the latter
  3784 may only occur in 'syntax' specifications or type abbreviations.
  3785 Before that distinction was only partially implemented via type class
  3786 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3787 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3788 exotic syntax specifications may require further adaption
  3789 (e.g. Cube/Cube.thy).
  3790 
  3791 * Removed obsolete type class "logic", use the top sort {} instead.
  3792 Note that non-logical types should be declared as 'nonterminals'
  3793 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3794 specifications.
  3795 
  3796 * Attributes 'induct' and 'cases': type or set names may now be
  3797 locally fixed variables as well.
  3798 
  3799 * Simplifier: can now control the depth to which conditional rewriting
  3800 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3801 Limit.
  3802 
  3803 * Simplifier: simplification procedures may now take the current
  3804 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3805 interface), which is very useful for calling the Simplifier
  3806 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3807 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3808 low-level mk_simproc no longer applies Logic.varify internally, to
  3809 allow for use in a context of fixed variables.
  3810 
  3811 * thin_tac now works even if the assumption being deleted contains !!
  3812 or ==>.  More generally, erule now works even if the major premise of
  3813 the elimination rule contains !! or ==>.
  3814 
  3815 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3816 
  3817 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3818 from Pure, which contains all common declarations already.  Both
  3819 theories are defined via plain Isabelle/Isar .thy files.
  3820 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3821 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3822 use isatool fixcpure to adapt your theory and ML sources.
  3823 
  3824 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3825 selections of theorems in named facts via index ranges.
  3826 
  3827 * 'print_theorems': in theory mode, really print the difference
  3828 wrt. the last state (works for interactive theory development only),
  3829 in proof mode print all local facts (cf. 'print_facts');
  3830 
  3831 * 'hide': option '(open)' hides only base names.
  3832 
  3833 * More efficient treatment of intermediate checkpoints in interactive
  3834 theory development.
  3835 
  3836 * Code generator is now invoked via code_module (incremental code
  3837 generation) and code_library (modular code generation, ML structures
  3838 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3839 must be quoted when used as identifiers.
  3840 
  3841 * New 'value' command for reading, evaluating and printing terms using
  3842 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3843 quoted when used as identifier.
  3844 
  3845 
  3846 *** Locales ***
  3847 
  3848 * New commands for the interpretation of locale expressions in
  3849 theories (1), locales (2) and proof contexts (3).  These generate
  3850 proof obligations from the expression specification.  After the
  3851 obligations have been discharged, theorems of the expression are added
  3852 to the theory, target locale or proof context.  The synopsis of the
  3853 commands is a follows:
  3854 
  3855   (1) interpretation expr inst
  3856   (2) interpretation target < expr
  3857   (3) interpret expr inst
  3858 
  3859 Interpretation in theories and proof contexts require a parameter
  3860 instantiation of terms from the current context.  This is applied to
  3861 specifications and theorems of the interpreted expression.
  3862 Interpretation in locales only permits parameter renaming through the
  3863 locale expression.  Interpretation is smart in that interpretations
  3864 that are active already do not occur in proof obligations, neither are
  3865 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3866 inspect active interpretations of a particular locale.  For details,
  3867 see the Isar Reference manual.  Examples can be found in
  3868 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3869 
  3870 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3871 'interpret' instead.
  3872 
  3873 * New context element 'constrains' for adding type constraints to
  3874 parameters.
  3875 
  3876 * Context expressions: renaming of parameters with syntax
  3877 redeclaration.
  3878 
  3879 * Locale declaration: 'includes' disallowed.
  3880 
  3881 * Proper static binding of attribute syntax -- i.e. types / terms /
  3882 facts mentioned as arguments are always those of the locale definition
  3883 context, independently of the context of later invocations.  Moreover,
  3884 locale operations (renaming and type / term instantiation) are applied
  3885 to attribute arguments as expected.
  3886 
  3887 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3888 actual attributes; rare situations may require Attrib.attribute to
  3889 embed those attributes into Attrib.src that lack concrete syntax.
  3890 Attribute implementations need to cooperate properly with the static
  3891 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3892 Attrib.XXX_thm etc. already do the right thing without further
  3893 intervention.  Only unusual applications -- such as "where" or "of"
  3894 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3895 on the context and the facts involved -- may have to assign parsed
  3896 values to argument tokens explicitly.
  3897 
  3898 * Changed parameter management in theorem generation for long goal
  3899 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3900 theorem statement in rare situations.
  3901 
  3902 * Locale inspection command 'print_locale' omits notes elements.  Use
  3903 'print_locale!' to have them included in the output.
  3904 
  3905 
  3906 *** Provers ***
  3907 
  3908 * Provers/hypsubst.ML: improved version of the subst method, for
  3909 single-step rewriting: it now works in bound variable contexts. New is
  3910 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3911 rewrite a different subterm than the original subst method, which is
  3912 still available as 'simplesubst'.
  3913 
  3914 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3915 and quasi orders.
  3916 
  3917 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3918 reflexive-transitive closure of relations.
  3919 
  3920 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3921 limit (previously hard-coded with a value of 20) user-definable.
  3922 
  3923 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3924 is peformed already.  Object-logics merely need to finish their
  3925 initial simpset configuration as before.  INCOMPATIBILITY.
  3926 
  3927 
  3928 *** HOL ***
  3929 
  3930 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3931 
  3932   syntax (epsilon)
  3933     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3934 
  3935 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3936 and x-symbol; use option '-m epsilon' to get it actually printed.
  3937 Moreover, the mathematically important symbolic identifier \<epsilon>
  3938 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3939 
  3940 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3941 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3942 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3943 support corresponding Isar calculations.
  3944 
  3945 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3946 instead of ":".
  3947 
  3948 * theory SetInterval: changed the syntax for open intervals:
  3949 
  3950   Old       New
  3951   {..n(}    {..<n}
  3952   {)n..}    {n<..}
  3953   {m..n(}   {m..<n}
  3954   {)m..n}   {m<..n}
  3955   {)m..n(}  {m<..<n}
  3956 
  3957 The old syntax is still supported but will disappear in the next
  3958 release.  For conversion use the following Emacs search and replace
  3959 patterns (these are not perfect but work quite well):
  3960 
  3961   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3962   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3963 
  3964 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3965 equalities in commutative rings; method 'algebra' provides a generic
  3966 interface.
  3967 
  3968 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3969 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3970 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3971 be a tuple pattern.
  3972 
  3973 Some new syntax forms are available:
  3974 
  3975   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3976   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3977   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3978   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3979 
  3980 The latter form "\<Sum>x < k. e" used to be based on a separate
  3981 function "Summation", which has been discontinued.
  3982 
  3983 * theory Finite_Set: in structured induction proofs, the insert case
  3984 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3985 (insert F x)'.
  3986 
  3987 * The 'refute' command has been extended to support a much larger
  3988 fragment of HOL, including axiomatic type classes, constdefs and
  3989 typedefs, inductive datatypes and recursion.
  3990 
  3991 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3992 Requires zChaff with proof generation to be installed.  See
  3993 HOL/ex/SAT_Examples.thy for examples.
  3994 
  3995 * Datatype induction via method 'induct' now preserves the name of the
  3996 induction variable. For example, when proving P(xs::'a list) by
  3997 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3998 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3999 in unstructured proof scripts.
  4000 
  4001 * Reworked implementation of records.  Improved scalability for
  4002 records with many fields, avoiding performance problems for type
  4003 inference. Records are no longer composed of nested field types, but
  4004 of nested extension types. Therefore the record type only grows linear
  4005 in the number of extensions and not in the number of fields.  The
  4006 top-level (users) view on records is preserved.  Potential
  4007 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4008 old record representation. The type generated for a record is called
  4009 <record_name>_ext_type.
  4010 
  4011 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4012 proofs triggered by a record definition or a simproc (if
  4013 quick_and_dirty is enabled).  Definitions of large records can take
  4014 quite long.
  4015 
  4016 New simproc record_upd_simproc for simplification of multiple record
  4017 updates enabled by default.  Moreover, trivial updates are also
  4018 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4019 occasionally, since simplification is more powerful by default.
  4020 
  4021 * typedef: proper support for polymorphic sets, which contain extra
  4022 type-variables in the term.
  4023 
  4024 * Simplifier: automatically reasons about transitivity chains
  4025 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4026 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4027 old proofs break occasionally as simplification may now solve more
  4028 goals than previously.
  4029 
  4030 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4031 present.  Works for all partial orders (class "order"), in particular
  4032 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4033 just like y <= x.
  4034 
  4035 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4036 bound variable or a constant then the let is unfolded.  Otherwise
  4037 first a is simplified to b, and then f b is simplified to g. If
  4038 possible we abstract b from g arriving at "let x = b in h x",
  4039 otherwise we unfold the let and arrive at g.  The simproc can be
  4040 enabled/disabled by the reference use_let_simproc.  Potential
  4041 INCOMPATIBILITY since simplification is more powerful by default.
  4042 
  4043 * Classical reasoning: the meson method now accepts theorems as arguments.
  4044 
  4045 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4046 jobs to provide advice on the provability of subgoals.
  4047 
  4048 * Theory OrderedGroup and Ring_and_Field: various additions and
  4049 improvements to faciliate calculations involving equalities and
  4050 inequalities.
  4051 
  4052 The following theorems have been eliminated or modified
  4053 (INCOMPATIBILITY):
  4054 
  4055   abs_eq             now named abs_of_nonneg
  4056   abs_of_ge_0        now named abs_of_nonneg
  4057   abs_minus_eq       now named abs_of_nonpos
  4058   imp_abs_id         now named abs_of_nonneg
  4059   imp_abs_neg_id     now named abs_of_nonpos
  4060   mult_pos           now named mult_pos_pos
  4061   mult_pos_le        now named mult_nonneg_nonneg
  4062   mult_pos_neg_le    now named mult_nonneg_nonpos
  4063   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4064   mult_neg           now named mult_neg_neg
  4065   mult_neg_le        now named mult_nonpos_nonpos
  4066 
  4067 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4068      
  4069      zero_le_square
  4070      not_square_less_zero 
  4071 
  4072   The following lemmas have been deleted from Real/RealPow:
  4073   
  4074      realpow_zero_zero
  4075      realpow_two
  4076      realpow_less
  4077      zero_le_power
  4078      realpow_two_le
  4079      abs_realpow_two
  4080      realpow_two_abs     
  4081 
  4082 * Theory Parity: added rules for simplifying exponents.
  4083 
  4084 * Theory List:
  4085 
  4086 The following theorems have been eliminated or modified
  4087 (INCOMPATIBILITY):
  4088 
  4089   list_all_Nil       now named list_all.simps(1)
  4090   list_all_Cons      now named list_all.simps(2)
  4091   list_all_conv      now named list_all_iff
  4092   set_mem_eq         now named mem_iff
  4093 
  4094 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4095 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4096 
  4097 
  4098 *** HOL-Complex ***
  4099 
  4100 * Theory RealDef: better support for embedding natural numbers and
  4101 integers in the reals.
  4102 
  4103 The following theorems have been eliminated or modified
  4104 (INCOMPATIBILITY):
  4105 
  4106   exp_ge_add_one_self  now requires no hypotheses
  4107   real_of_int_add      reversed direction of equality (use [symmetric])
  4108   real_of_int_minus    reversed direction of equality (use [symmetric])
  4109   real_of_int_diff     reversed direction of equality (use [symmetric])
  4110   real_of_int_mult     reversed direction of equality (use [symmetric])
  4111 
  4112 * Theory RComplete: expanded support for floor and ceiling functions.
  4113 
  4114 * Theory Ln is new, with properties of the natural logarithm
  4115 
  4116 * Hyperreal: There is a new type constructor "star" for making
  4117 nonstandard types.  The old type names are now type synonyms:
  4118 
  4119   hypreal = real star
  4120   hypnat = nat star
  4121   hcomplex = complex star
  4122 
  4123 * Hyperreal: Many groups of similarly-defined constants have been
  4124 replaced by polymorphic versions (INCOMPATIBILITY):
  4125 
  4126   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4127 
  4128   starset      <-- starsetNat, starsetC
  4129   *s*          <-- *sNat*, *sc*
  4130   starset_n    <-- starsetNat_n, starsetC_n
  4131   *sn*         <-- *sNatn*, *scn*
  4132   InternalSets <-- InternalNatSets, InternalCSets
  4133 
  4134   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4135   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4136   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4137   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4138   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4139 
  4140 * Hyperreal: Many type-specific theorems have been removed in favor of
  4141 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4142 
  4143   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4144   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4145   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4146   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4147   right_minus <-- hypreal_add_minus
  4148   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4149   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4150   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4151   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4152   mult_1_right <-- hcomplex_mult_one_right
  4153   mult_zero_left <-- hcomplex_mult_zero_left
  4154   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4155   right_distrib <-- hypnat_add_mult_distrib2
  4156   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4157   right_inverse <-- hypreal_mult_inverse
  4158   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4159   order_refl <-- {hypreal,hypnat}_le_refl
  4160   order_trans <-- {hypreal,hypnat}_le_trans
  4161   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4162   order_less_le <-- {hypreal,hypnat}_less_le
  4163   linorder_linear <-- {hypreal,hypnat}_le_linear
  4164   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4165   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4166   add_nonneg_nonneg <-- hypreal_le_add_order
  4167 
  4168 * Hyperreal: Separate theorems having to do with type-specific
  4169 versions of constants have been merged into theorems that apply to the
  4170 new polymorphic constants (INCOMPATIBILITY):
  4171 
  4172   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4173   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4174   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4175   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4176   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4177   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4178   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4179   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4180   STAR_diff <-- {STAR,STARC}_diff
  4181   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4182     STARC_hcomplex_of_complex}_image_subset
  4183   starset_n_Un <-- starset{Nat,C}_n_Un
  4184   starset_n_Int <-- starset{Nat,C}_n_Int
  4185   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4186   starset_n_diff <-- starset{Nat,C}_n_diff
  4187   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4188   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4189   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4190   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4191   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4192   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4193   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4194   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4195   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4196   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4197   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4198   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4199   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4200   starfun_diff <-- starfun{C,RC,CR}_diff
  4201   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4202   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4203   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4204   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4205   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4206   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4207   starfun_Id <-- starfunC_Id
  4208   starfun_approx <-- starfun{Nat,CR}_approx
  4209   starfun_capprox <-- starfun{C,RC}_capprox
  4210   starfun_abs <-- starfunNat_rabs
  4211   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4212   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4213   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4214   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4215   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4216   starfun_add_approx <-- starfunCR_add_approx
  4217   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4218   starfun_divide <-- starfun{C,CR,RC}_divide
  4219   starfun_n <-- starfun{Nat,C}_n
  4220   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4221   starfun_n_add <-- starfun{Nat,C}_n_add
  4222   starfun_n_add_minus <-- starfunNat_n_add_minus
  4223   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4224   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4225   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4226 
  4227   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4228   star_n_minus <-- {hypreal,hcomplex}_minus
  4229   star_n_diff <-- {hypreal,hcomplex}_diff
  4230   star_n_mult <-- {hypreal,hcomplex}_mult
  4231   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4232   star_n_le <-- {hypreal,hypnat}_le
  4233   star_n_less <-- {hypreal,hypnat}_less
  4234   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4235   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4236   star_n_abs <-- hypreal_hrabs
  4237   star_n_divide <-- hcomplex_divide
  4238 
  4239   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4240   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4241   star_of_diff <-- hypreal_of_real_diff
  4242   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4243   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4244   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4245   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4246   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4247   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4248   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4249   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4250   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4251   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4252   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4253   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4254   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4255   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4256   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4257   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4258   star_of_power <-- hypreal_of_real_power
  4259   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4260 
  4261 * Hyperreal: new method "transfer" that implements the transfer
  4262 principle of nonstandard analysis. With a subgoal that mentions
  4263 nonstandard types like "'a star", the command "apply transfer"
  4264 replaces it with an equivalent one that mentions only standard types.
  4265 To be successful, all free variables must have standard types; non-
  4266 standard variables must have explicit universal quantifiers.
  4267 
  4268 * Hyperreal: A theory of Taylor series.
  4269 
  4270 
  4271 *** HOLCF ***
  4272 
  4273 * Discontinued special version of 'constdefs' (which used to support
  4274 continuous functions) in favor of the general Pure one with full
  4275 type-inference.
  4276 
  4277 * New simplification procedure for solving continuity conditions; it
  4278 is much faster on terms with many nested lambda abstractions (cubic
  4279 instead of exponential time).
  4280 
  4281 * New syntax for domain package: selector names are now optional.
  4282 Parentheses should be omitted unless argument is lazy, for example:
  4283 
  4284   domain 'a stream = cons "'a" (lazy "'a stream")
  4285 
  4286 * New command 'fixrec' for defining recursive functions with pattern
  4287 matching; defining multiple functions with mutual recursion is also
  4288 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4289 sinr, or any data constructor defined by the domain package. The given
  4290 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4291 syntax and examples.
  4292 
  4293 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4294 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4295 but the proof obligation additionally includes an admissibility
  4296 requirement. The packages generate instances of class cpo or pcpo,
  4297 with continuity and strictness theorems for Rep and Abs.
  4298 
  4299 * HOLCF: Many theorems have been renamed according to a more standard naming
  4300 scheme (INCOMPATIBILITY):
  4301 
  4302   foo_inject:  "foo$x = foo$y ==> x = y"
  4303   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4304   foo_less:    "(foo$x << foo$y) = (x << y)"
  4305   foo_strict:  "foo$UU = UU"
  4306   foo_defined: "... ==> foo$x ~= UU"
  4307   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4308 
  4309 
  4310 *** ZF ***
  4311 
  4312 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4313 including the First Isomorphism Theorem (on quotienting by the kernel
  4314 of a homomorphism).
  4315 
  4316 * ZF/Simplifier: install second copy of type solver that actually
  4317 makes use of TC rules declared to Isar proof contexts (or locales);
  4318 the old version is still required for ML proof scripts.
  4319 
  4320 
  4321 *** Cube ***
  4322 
  4323 * Converted to Isar theory format; use locales instead of axiomatic
  4324 theories.
  4325 
  4326 
  4327 *** ML ***
  4328 
  4329 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4330 for ||>, ||>>, |>>,
  4331 
  4332 * Pure/library.ML no longer defines its own option datatype, but uses
  4333 that of the SML basis, which has constructors NONE and SOME instead of
  4334 None and Some, as well as exception Option.Option instead of OPTION.
  4335 The functions the, if_none, is_some, is_none have been adapted
  4336 accordingly, while Option.map replaces apsome.
  4337 
  4338 * Pure/library.ML: the exception LIST has been given up in favour of
  4339 the standard exceptions Empty and Subscript, as well as
  4340 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4341 superceded by the standard hd and tl functions etc.
  4342 
  4343 A number of basic list functions are no longer exported to the ML
  4344 toplevel, as they are variants of predefined functions.  The following
  4345 suggests how one can translate existing code:
  4346 
  4347     rev_append xs ys = List.revAppend (xs, ys)
  4348     nth_elem (i, xs) = List.nth (xs, i)
  4349     last_elem xs = List.last xs
  4350     flat xss = List.concat xss
  4351     seq fs = List.app fs
  4352     partition P xs = List.partition P xs
  4353     mapfilter f xs = List.mapPartial f xs
  4354 
  4355 * Pure/library.ML: several combinators for linear functional
  4356 transformations, notably reverse application and composition:
  4357 
  4358   x |> f                f #> g
  4359   (x, y) |-> f          f #-> g
  4360 
  4361 * Pure/library.ML: introduced/changed precedence of infix operators:
  4362 
  4363   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4364   infix 2 ?;
  4365   infix 3 o oo ooo oooo;
  4366   infix 4 ~~ upto downto;
  4367 
  4368 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4369 infix operators.
  4370 
  4371 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4372 fold_map support linear functional transformations and nesting.  For
  4373 example:
  4374 
  4375   fold f [x1, ..., xN] y =
  4376     y |> f x1 |> ... |> f xN
  4377 
  4378   (fold o fold) f [xs1, ..., xsN] y =
  4379     y |> fold f xs1 |> ... |> fold f xsN
  4380 
  4381   fold f [x1, ..., xN] =
  4382     f x1 #> ... #> f xN
  4383 
  4384   (fold o fold) f [xs1, ..., xsN] =
  4385     fold f xs1 #> ... #> fold f xsN
  4386 
  4387 * Pure/library.ML: the following selectors on type 'a option are
  4388 available:
  4389 
  4390   the:               'a option -> 'a  (*partial*)
  4391   these:             'a option -> 'a  where 'a = 'b list
  4392   the_default: 'a -> 'a option -> 'a
  4393   the_list:          'a option -> 'a list
  4394 
  4395 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4396 basic operations for association lists, following natural argument
  4397 order; moreover the explicit equality predicate passed here avoids
  4398 potentially expensive polymorphic runtime equality checks.
  4399 The old functions may be expressed as follows:
  4400 
  4401   assoc = uncurry (AList.lookup (op =))
  4402   assocs = these oo AList.lookup (op =)
  4403   overwrite = uncurry (AList.update (op =)) o swap
  4404 
  4405 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4406 
  4407   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4408   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4409 
  4410 replacing make_keylist and keyfilter (occassionally used)
  4411 Naive rewrites:
  4412 
  4413   make_keylist = AList.make
  4414   keyfilter = AList.find (op =)
  4415 
  4416 * eq_fst and eq_snd now take explicit equality parameter, thus
  4417   avoiding eqtypes. Naive rewrites:
  4418 
  4419     eq_fst = eq_fst (op =)
  4420     eq_snd = eq_snd (op =)
  4421 
  4422 * Removed deprecated apl and apr (rarely used).
  4423   Naive rewrites:
  4424 
  4425     apl (n, op) =>>= curry op n
  4426     apr (op, m) =>>= fn n => op (n, m)
  4427 
  4428 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4429 provides a reasonably efficient light-weight implementation of sets as
  4430 lists.
  4431 
  4432 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4433 few new operations; existing lookup and update are now curried to
  4434 follow natural argument order (for use with fold etc.);
  4435 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4436 
  4437 * Pure/General: output via the Isabelle channels of
  4438 writeln/warning/error etc. is now passed through Output.output, with a
  4439 hook for arbitrary transformations depending on the print_mode
  4440 (cf. Output.add_mode -- the first active mode that provides a output
  4441 function wins).  Already formatted output may be embedded into further
  4442 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4443 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4444 accommodate easy composition of diagnostic messages etc.  Programmers
  4445 rarely need to care about Output.output or Output.raw at all, with
  4446 some notable exceptions: Output.output is required when bypassing the
  4447 standard channels (writeln etc.), or in token translations to produce
  4448 properly formatted results; Output.raw is required when capturing
  4449 already output material that will eventually be presented to the user
  4450 a second time.  For the default print mode, both Output.output and
  4451 Output.raw have no effect.
  4452 
  4453 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4454 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4455 cumulative results are displayed at the end of a batch session.
  4456 
  4457 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4458 replaced by File.platform_path and File.shell_path (with appropriate
  4459 hooks).  This provides a clean interface for unusual systems where the
  4460 internal and external process view of file names are different.
  4461 
  4462 * Pure: more efficient orders for basic syntactic entities: added
  4463 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4464 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4465 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4466 orders now -- potential INCOMPATIBILITY for code that depends on a
  4467 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4468 Library.sort_strings on result).
  4469 
  4470 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4471 fold_types traverse types/terms from left to right, observing natural
  4472 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4473 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4474 
  4475 * Pure: name spaces have been refined, with significant changes of the
  4476 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4477 to extern(_table).  The plain name entry path is superceded by a
  4478 general 'naming' context, which also includes the 'policy' to produce
  4479 a fully qualified name and external accesses of a fully qualified
  4480 name; NameSpace.extend is superceded by context dependent
  4481 Sign.declare_name.  Several theory and proof context operations modify
  4482 the naming context.  Especially note Theory.restore_naming and
  4483 ProofContext.restore_naming to get back to a sane state; note that
  4484 Theory.add_path is no longer sufficient to recover from
  4485 Theory.absolute_path in particular.
  4486 
  4487 * Pure: new flags short_names (default false) and unique_names
  4488 (default true) for controlling output of qualified names.  If
  4489 short_names is set, names are printed unqualified.  If unique_names is
  4490 reset, the name prefix is reduced to the minimum required to achieve
  4491 the original result when interning again, even if there is an overlap
  4492 with earlier declarations.
  4493 
  4494 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4495 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4496 (useful for printing error messages).  INCOMPATIBILITY.
  4497 
  4498 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4499 Theory.theory are now identified, referring to the universal
  4500 Context.theory (see Pure/context.ML).  Actual signature and theory
  4501 content is managed as theory data.  The old code and interfaces were
  4502 spread over many files and structures; the new arrangement introduces
  4503 considerable INCOMPATIBILITY to gain more clarity:
  4504 
  4505   Context -- theory management operations (name, identity, inclusion,
  4506     parents, ancestors, merge, etc.), plus generic theory data;
  4507 
  4508   Sign -- logical signature and syntax operations (declaring consts,
  4509     types, etc.), plus certify/read for common entities;
  4510 
  4511   Theory -- logical theory operations (stating axioms, definitions,
  4512     oracles), plus a copy of logical signature operations (consts,
  4513     types, etc.); also a few basic management operations (Theory.copy,
  4514     Theory.merge, etc.)
  4515 
  4516 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4517 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4518 for convenience -- they merely return the theory.
  4519 
  4520 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4521 
  4522 * Pure: the Isar proof context type is already defined early in Pure
  4523 as Context.proof (note that ProofContext.context and Proof.context are
  4524 aliases, where the latter is the preferred name).  This enables other
  4525 Isabelle components to refer to that type even before Isar is present.
  4526 
  4527 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4528 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4529 any of these kinds.  For example, Sign.intern typeK is now
  4530 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4531 Theory.hide_types.  Also note that former
  4532 Theory.hide_classes/types/consts are now
  4533 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4534 internalize their arguments!  INCOMPATIBILITY.
  4535 
  4536 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4537 datatype thmref (with constructors Name and NameSelection) instead of
  4538 plain string -- INCOMPATIBILITY;
  4539 
  4540 * Pure: cases produced by proof methods specify options, where NONE
  4541 means to remove case bindings -- INCOMPATIBILITY in
  4542 (RAW_)METHOD_CASES.
  4543 
  4544 * Pure: the following operations retrieve axioms or theorems from a
  4545 theory node or theory hierarchy, respectively:
  4546 
  4547   Theory.axioms_of: theory -> (string * term) list
  4548   Theory.all_axioms_of: theory -> (string * term) list
  4549   PureThy.thms_of: theory -> (string * thm) list
  4550   PureThy.all_thms_of: theory -> (string * thm) list
  4551 
  4552 * Pure: print_tac now outputs the goal through the trace channel.
  4553 
  4554 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4555 Reference Toplevel.debug (default false) controls detailed printing
  4556 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4557 controls execution profiling -- set to 1 for time and 2 for space
  4558 (both increase the runtime).
  4559 
  4560 * Isar session: The initial use of ROOT.ML is now always timed,
  4561 i.e. the log will show the actual process times, in contrast to the
  4562 elapsed wall-clock time that the outer shell wrapper produces.
  4563 
  4564 * Simplifier: improved handling of bound variables (nameless
  4565 representation, avoid allocating new strings).  Simprocs that invoke
  4566 the Simplifier recursively should use Simplifier.inherit_bounds to
  4567 avoid local name clashes.  Failure to do so produces warnings
  4568 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4569 for further details.
  4570 
  4571 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4572 bindings for all theorems stored within a given theory; this may help
  4573 in porting non-Isar theories to Isar ones, while keeping ML proof
  4574 scripts for the time being.
  4575 
  4576 * ML operator HTML.with_charset specifies the charset begin used for
  4577 generated HTML files.  For example:
  4578 
  4579   HTML.with_charset "utf-8" use_thy "Hebrew";
  4580   HTML.with_charset "utf-8" use_thy "Chinese";
  4581 
  4582 
  4583 *** System ***
  4584 
  4585 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4586 isabelle, isatool etc.).
  4587 
  4588 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4589 isatool doc, isatool mkdir, display_drafts etc.).
  4590 
  4591 * isatool usedir: option -f allows specification of the ML file to be
  4592 used by Isabelle; default is ROOT.ML.
  4593 
  4594 * New isatool version outputs the version identifier of the Isabelle
  4595 distribution being used.
  4596 
  4597 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4598 (containing Boolean satisfiability problems) into Isabelle/HOL
  4599 theories.
  4600 
  4601 
  4602 
  4603 New in Isabelle2004 (April 2004)
  4604 --------------------------------
  4605 
  4606 *** General ***
  4607 
  4608 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4609   Replaces linorder.ML.
  4610 
  4611 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4612   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4613   (\<a>...\<z>), are now considered normal letters, and can therefore
  4614   be used anywhere where an ASCII letter (a...zA...Z) has until
  4615   now. COMPATIBILITY: This obviously changes the parsing of some
  4616   terms, especially where a symbol has been used as a binder, say
  4617   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4618   as an identifier.  Fix it by inserting a space around former
  4619   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4620   existing theory and ML files.
  4621 
  4622 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4623 
  4624 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4625   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4626   a normal (but invisible) letter. For multiple letter subscripts repeat
  4627   \<^isub> like this: x\<^isub>1\<^isub>2.
  4628 
  4629 * Pure: There are now sub-/superscripts that can span more than one
  4630   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4631   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4632   superscript. The new control characters are not identifier parts.
  4633 
  4634 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4635   content of "..." to the latex file instead of \isacntrl... . The "..."
  4636   may consist of any printable characters excluding the end bracket >.
  4637 
  4638 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4639   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4640   declare constants "final", which prevents their being given a definition
  4641   later.  It is useful for constants whose behaviour is fixed axiomatically
  4642   rather than definitionally, such as the meta-logic connectives.
  4643 
  4644 * Pure: 'instance' now handles general arities with general sorts
  4645   (i.e. intersections of classes),
  4646 
  4647 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4648   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4649   It can be changed to alter the colors/layout of generated pages.
  4650 
  4651 
  4652 *** Isar ***
  4653 
  4654 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4655   cut_tac, subgoal_tac and thin_tac:
  4656   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4657     locales are no longer forced to write Isar proof scripts.
  4658     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4659     emulations.
  4660   - INCOMPATIBILITY: names of variables to be instantiated may no
  4661     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4662     This is consistent with the instantiation attribute "where".
  4663 
  4664 * Attributes "where" and "of":
  4665   - Now take type variables of instantiated theorem into account when reading
  4666     the instantiation string.  This fixes a bug that caused instantiated
  4667     theorems to have too special types in some circumstances.
  4668   - "where" permits explicit instantiations of type variables.
  4669 
  4670 * Calculation commands "moreover" and "also" no longer interfere with
  4671   current facts ("this"), admitting arbitrary combinations with "then"
  4672   and derived forms.
  4673 
  4674 * Locales:
  4675   - Goal statements involving the context element "includes" no longer
  4676     generate theorems with internal delta predicates (those ending on
  4677     "_axioms") in the premise.
  4678     Resolve particular premise with <locale>.intro to obtain old form.
  4679   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4680     specification and "includes" elements in goal statement.
  4681   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4682     [intro?] and [elim?] (respectively) by default.
  4683   - Experimental command for instantiation of locales in proof contexts:
  4684         instantiate <label>[<attrs>]: <loc>
  4685     Instantiates locale <loc> and adds all its theorems to the current context
  4686     taking into account their attributes.  Label and attrs are optional
  4687     modifiers, like in theorem declarations.  If present, names of
  4688     instantiated theorems are qualified with <label>, and the attributes
  4689     <attrs> are applied after any attributes these theorems might have already.
  4690       If the locale has assumptions, a chained fact of the form
  4691     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4692     are derived.  The command does not support old-style locales declared
  4693     with "locale (open)".
  4694       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4695 
  4696 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4697   (Isar) contexts.
  4698 
  4699 
  4700 *** HOL ***
  4701 
  4702 * Proof import: new image HOL4 contains the imported library from
  4703   the HOL4 system with about 2500 theorems. It is imported by
  4704   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4705   can be used like any other Isabelle image.  See
  4706   HOL/Import/HOL/README for more information.
  4707 
  4708 * Simplifier:
  4709   - Much improved handling of linear and partial orders.
  4710     Reasoners for linear and partial orders are set up for type classes
  4711     "linorder" and "order" respectively, and are added to the default simpset
  4712     as solvers.  This means that the simplifier can build transitivity chains
  4713     to solve goals from the assumptions.
  4714   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4715     of blast or auto after simplification become unnecessary because the goal
  4716     is solved by simplification already.
  4717 
  4718 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4719     all proved in axiomatic type classes for semirings, rings and fields.
  4720 
  4721 * Numerics:
  4722   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4723     now formalized using the Ring_and_Field theory mentioned above.
  4724   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4725     than before, because now they are set up once in a generic manner.
  4726   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4727     Look for the general versions in Ring_and_Field (and Power if they concern
  4728     exponentiation).
  4729 
  4730 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4731 
  4732 * Records:
  4733   - Record types are now by default printed with their type abbreviation
  4734     instead of the list of all field types. This can be configured via
  4735     the reference "print_record_type_abbr".
  4736   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4737     (not enabled by default).
  4738   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4739     EX x. x = sel r to True (not enabled by default).
  4740   - Tactic "record_split_simp_tac" to split and simplify records added.
  4741 
  4742 * 'specification' command added, allowing for definition by
  4743   specification.  There is also an 'ax_specification' command that
  4744   introduces the new constants axiomatically.
  4745 
  4746 * arith(_tac) is now able to generate counterexamples for reals as well.
  4747 
  4748 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4749 
  4750 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4751   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4752 
  4753 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4754   matrix theory to linear programming.
  4755 
  4756 * Unions and Intersections:
  4757   The latex output syntax of UN and INT has been changed
  4758   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4759   i.e. the index formulae has become a subscript.
  4760   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4761 
  4762 * Unions and Intersections over Intervals:
  4763   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4764   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4765   like in normal math, and corresponding versions for < and for intersection.
  4766 
  4767 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4768   lexicographic dictonary ordering has been added as "lexord".
  4769 
  4770 * ML: the legacy theory structures Int and List have been removed. They had
  4771   conflicted with ML Basis Library structures having the same names.
  4772 
  4773 * 'refute' command added to search for (finite) countermodels.  Only works
  4774   for a fragment of HOL.  The installation of an external SAT solver is
  4775   highly recommended.  See "HOL/Refute.thy" for details.
  4776 
  4777 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4778   formulae under an assignment of free variables to random values.
  4779   In contrast to 'refute', it can deal with inductive datatypes,
  4780   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4781   for examples.
  4782 
  4783 
  4784 *** HOLCF ***
  4785 
  4786 * Streams now come with concatenation and are part of the HOLCF image
  4787 
  4788 
  4789 
  4790 New in Isabelle2003 (May 2003)
  4791 ------------------------------
  4792 
  4793 *** General ***
  4794 
  4795 * Provers/simplifier:
  4796 
  4797   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4798     Assumptions are now subject to complete mutual simplification,
  4799     not just from left to right. The simplifier now preserves
  4800     the order of assumptions.
  4801 
  4802     Potential INCOMPATIBILITY:
  4803 
  4804     -- simp sometimes diverges where the old version did
  4805        not, e.g. invoking simp on the goal
  4806 
  4807         [| P (f x); y = x; f x = f y |] ==> Q
  4808 
  4809        now gives rise to the infinite reduction sequence
  4810 
  4811         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4812 
  4813        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4814        kind of problem.
  4815 
  4816     -- Tactics combining classical reasoner and simplification (such as auto)
  4817        are also affected by this change, because many of them rely on
  4818        simp. They may sometimes diverge as well or yield a different numbers
  4819        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4820        in case of problems. Sometimes subsequent calls to the classical
  4821        reasoner will fail because a preceeding call to the simplifier too
  4822        eagerly simplified the goal, e.g. deleted redundant premises.
  4823 
  4824   - The simplifier trace now shows the names of the applied rewrite rules
  4825 
  4826   - You can limit the number of recursive invocations of the simplifier
  4827     during conditional rewriting (where the simplifie tries to solve the
  4828     conditions before applying the rewrite rule):
  4829     ML "simp_depth_limit := n"
  4830     where n is an integer. Thus you can force termination where previously
  4831     the simplifier would diverge.
  4832 
  4833   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4834 
  4835   - No longer aborts on failed congruence proof.  Instead, the
  4836     congruence is ignored.
  4837 
  4838 * Pure: New generic framework for extracting programs from constructive
  4839   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4840   as HOL/Extraction for some case studies.
  4841 
  4842 * Pure: The main goal of the proof state is no longer shown by default, only
  4843 the subgoals. This behaviour is controlled by a new flag.
  4844    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4845 (ML: Proof.show_main_goal).
  4846 
  4847 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4848 rules whose conclusion matches subgoal 1:
  4849       PG menu: Isabelle/Isar -> Show me -> matching rules
  4850 The rules are ordered by how closely they match the subgoal.
  4851 In particular, rules that solve a subgoal outright are displayed first
  4852 (or rather last, the way they are printed).
  4853 (ML: ProofGeneral.print_intros())
  4854 
  4855 * Pure: New flag trace_unify_fail causes unification to print
  4856 diagnostic information (PG: in trace buffer) when it fails. This is
  4857 useful for figuring out why single step proofs like rule, erule or
  4858 assumption failed.
  4859 
  4860 * Pure: Locale specifications now produce predicate definitions
  4861 according to the body of text (covering assumptions modulo local
  4862 definitions); predicate "loc_axioms" covers newly introduced text,
  4863 while "loc" is cumulative wrt. all included locale expressions; the
  4864 latter view is presented only on export into the global theory
  4865 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4866 on the old view without predicates;
  4867 
  4868 * Pure: predefined locales "var" and "struct" are useful for sharing
  4869 parameters (as in CASL, for example); just specify something like
  4870 ``var x + var y + struct M'' as import;
  4871 
  4872 * Pure: improved thms_containing: proper indexing of facts instead of
  4873 raw theorems; check validity of results wrt. current name space;
  4874 include local facts of proof configuration (also covers active
  4875 locales), cover fixed variables in index; may use "_" in term
  4876 specification; an optional limit for the number of printed facts may
  4877 be given (the default is 40);
  4878 
  4879 * Pure: disallow duplicate fact bindings within new-style theory files
  4880 (batch-mode only);
  4881 
  4882 * Provers: improved induct method: assumptions introduced by case
  4883 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4884 the goal statement); "foo" still refers to all facts collectively;
  4885 
  4886 * Provers: the function blast.overloaded has been removed: all constants
  4887 are regarded as potentially overloaded, which improves robustness in exchange
  4888 for slight decrease in efficiency;
  4889 
  4890 * Provers/linorder: New generic prover for transitivity reasoning over
  4891 linear orders.  Note: this prover is not efficient!
  4892 
  4893 * Isar: preview of problems to finish 'show' now produce an error
  4894 rather than just a warning (in interactive mode);
  4895 
  4896 
  4897 *** HOL ***
  4898 
  4899 * arith(_tac)
  4900 
  4901  - Produces a counter example if it cannot prove a goal.
  4902    Note that the counter example may be spurious if the goal is not a formula
  4903    of quantifier-free linear arithmetic.
  4904    In ProofGeneral the counter example appears in the trace buffer.
  4905 
  4906  - Knows about div k and mod k where k is a numeral of type nat or int.
  4907 
  4908  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4909    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4910    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4911 
  4912 * simp's arithmetic capabilities have been enhanced a bit: it now
  4913 takes ~= in premises into account (by performing a case split);
  4914 
  4915 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4916 are distributed over a sum of terms;
  4917 
  4918 * New tactic "trans_tac" and method "trans" instantiate
  4919 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4920 "<=", "<" and "=").
  4921 
  4922 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4923 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4924 
  4925 * 'typedef' command has new option "open" to suppress the set
  4926 definition;
  4927 
  4928 * functions Min and Max on finite sets have been introduced (theory
  4929 Finite_Set);
  4930 
  4931 * attribute [symmetric] now works for relations as well; it turns
  4932 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4933 
  4934 * induct over a !!-quantified statement (say !!x1..xn):
  4935   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4936 
  4937 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4938 %x. None. Warning: empty_def now refers to the previously hidden definition
  4939 of the empty set.
  4940 
  4941 * Algebra: formalization of classical algebra.  Intended as base for
  4942 any algebraic development in Isabelle.  Currently covers group theory
  4943 (up to Sylow's theorem) and ring theory (Universal Property of
  4944 Univariate Polynomials).  Contributions welcome;
  4945 
  4946 * GroupTheory: deleted, since its material has been moved to Algebra;
  4947 
  4948 * Complex: new directory of the complex numbers with numeric constants,
  4949 nonstandard complex numbers, and some complex analysis, standard and
  4950 nonstandard (Jacques Fleuriot);
  4951 
  4952 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4953 
  4954 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4955 Fleuriot);
  4956 
  4957 * Real/HahnBanach: updated and adapted to locales;
  4958 
  4959 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4960 Gray and Kramer);
  4961 
  4962 * UNITY: added the Meier-Sanders theory of progress sets;
  4963 
  4964 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4965 as abstract algorithms, instantiated to the JVM;
  4966 
  4967 * Bali: Java source language formalization. Type system, operational
  4968 semantics, axiomatic semantics. Supported language features:
  4969 classes, interfaces, objects,virtual methods, static methods,
  4970 static/instance fields, arrays, access modifiers, definite
  4971 assignment, exceptions.
  4972 
  4973 
  4974 *** ZF ***
  4975 
  4976 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4977 universe, etc.);
  4978 
  4979 * Main ZF: virtually all theories converted to new-style format;
  4980 
  4981 
  4982 *** ML ***
  4983 
  4984 * Pure: Tactic.prove provides sane interface for internal proofs;
  4985 omits the infamous "standard" operation, so this is more appropriate
  4986 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4987 
  4988 * Pure: improved error reporting of simprocs;
  4989 
  4990 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4991 up simprocs;
  4992 
  4993 
  4994 *** Document preparation ***
  4995 
  4996 * uses \par instead of \\ for line breaks in theory text. This may
  4997 shift some page breaks in large documents. To get the old behaviour
  4998 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4999 
  5000 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5001 other packages
  5002 
  5003 * \<euro> now needs package babel/greek instead of marvosym (which
  5004 broke \Rightarrow)
  5005 
  5006 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5007 textcomp package)
  5008 
  5009 
  5010 
  5011 New in Isabelle2002 (March 2002)
  5012 --------------------------------
  5013 
  5014 *** Document preparation ***
  5015 
  5016 * greatly simplified document preparation setup, including more
  5017 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5018 instructive isatool mkdir; users should basically be able to get
  5019 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5020 users may run a separate document processing stage manually like this:
  5021 "isatool usedir -D output HOL Test && isatool document Test/output";
  5022 
  5023 * theory dependency graph may now be incorporated into documents;
  5024 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5025 with \includegraphics of LaTeX;
  5026 
  5027 * proper spacing of consecutive markup elements, especially text
  5028 blocks after section headings;
  5029 
  5030 * support bold style (for single symbols only), input syntax is like
  5031 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5032 
  5033 * \<bullet> is now output as bold \cdot by default, which looks much
  5034 better in printed text;
  5035 
  5036 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5037 note that these symbols are currently unavailable in Proof General /
  5038 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5039 
  5040 * isatool latex no longer depends on changed TEXINPUTS, instead
  5041 isatool document copies the Isabelle style files to the target
  5042 location;
  5043 
  5044 
  5045 *** Isar ***
  5046 
  5047 * Pure/Provers: improved proof by cases and induction;
  5048   - 'case' command admits impromptu naming of parameters (such as
  5049     "case (Suc n)");
  5050   - 'induct' method divinates rule instantiation from the inductive
  5051     claim; no longer requires excessive ?P bindings for proper
  5052     instantiation of cases;
  5053   - 'induct' method properly enumerates all possibilities of set/type
  5054     rules; as a consequence facts may be also passed through *type*
  5055     rules without further ado;
  5056   - 'induct' method now derives symbolic cases from the *rulified*
  5057     rule (before it used to rulify cases stemming from the internal
  5058     atomized version); this means that the context of a non-atomic
  5059     statement becomes is included in the hypothesis, avoiding the
  5060     slightly cumbersome show "PROP ?case" form;
  5061   - 'induct' may now use elim-style induction rules without chaining
  5062     facts, using ``missing'' premises from the goal state; this allows
  5063     rules stemming from inductive sets to be applied in unstructured
  5064     scripts, while still benefitting from proper handling of non-atomic
  5065     statements; NB: major inductive premises need to be put first, all
  5066     the rest of the goal is passed through the induction;
  5067   - 'induct' proper support for mutual induction involving non-atomic
  5068     rule statements (uses the new concept of simultaneous goals, see
  5069     below);
  5070   - append all possible rule selections, but only use the first
  5071     success (no backtracking);
  5072   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5073   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5074   - added 'print_induct_rules' (covered by help item in recent Proof
  5075     General versions);
  5076   - moved induct/cases attributes to Pure, methods to Provers;
  5077   - generic method setup instantiated for FOL and HOL;
  5078 
  5079 * Pure: support multiple simultaneous goal statements, for example
  5080 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5081 meta-level mechanism, this acts as if several individual goals had
  5082 been stated separately; in particular common proof methods need to be
  5083 repeated in order to cover all claims; note that a single elimination
  5084 step is *not* sufficient to establish the two conjunctions, so this
  5085 fails:
  5086 
  5087   assume "A & B" then have A and B ..   (*".." fails*)
  5088 
  5089 better use "obtain" in situations as above; alternative refer to
  5090 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5091 
  5092 * Pure: proper integration with ``locales''; unlike the original
  5093 version by Florian Kammller, Isar locales package high-level proof
  5094 contexts rather than raw logical ones (e.g. we admit to include
  5095 attributes everywhere); operations on locales include merge and
  5096 rename; support for implicit arguments (``structures''); simultaneous
  5097 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5098 some examples;
  5099 
  5100 * Pure: the following commands have been ``localized'', supporting a
  5101 target locale specification "(in name)": 'lemma', 'theorem',
  5102 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5103 stored both within the locale and at the theory level (exported and
  5104 qualified by the locale name);
  5105 
  5106 * Pure: theory goals may now be specified in ``long'' form, with
  5107 ad-hoc contexts consisting of arbitrary locale elements. for example
  5108 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5109 definitions may be given, too); the result is a meta-level rule with
  5110 the context elements being discharged in the obvious way;
  5111 
  5112 * Pure: new proof command 'using' allows to augment currently used
  5113 facts after a goal statement ('using' is syntactically analogous to
  5114 'apply', but acts on the goal's facts only); this allows chained facts
  5115 to be separated into parts given before and after a claim, as in
  5116 ``from a and b have C using d and e <proof>'';
  5117 
  5118 * Pure: renamed "antecedent" case to "rule_context";
  5119 
  5120 * Pure: new 'judgment' command records explicit information about the
  5121 object-logic embedding (used by several tools internally); no longer
  5122 use hard-wired "Trueprop";
  5123 
  5124 * Pure: added 'corollary' command;
  5125 
  5126 * Pure: fixed 'token_translation' command;
  5127 
  5128 * Pure: removed obsolete 'exported' attribute;
  5129 
  5130 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5131 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5132 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5133 
  5134 * Pure: method 'atomize' presents local goal premises as object-level
  5135 statements (atomic meta-level propositions); setup controlled via
  5136 rewrite rules declarations of 'atomize' attribute; example
  5137 application: 'induct' method with proper rule statements in improper
  5138 proof *scripts*;
  5139 
  5140 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5141 now consider the syntactic context of assumptions, giving a better
  5142 chance to get type-inference of the arguments right (this is
  5143 especially important for locales);
  5144 
  5145 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5146 mode;
  5147 
  5148 * Pure/obtain: the formal conclusion "thesis", being marked as
  5149 ``internal'', may no longer be reference directly in the text;
  5150 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5151 situations;
  5152 
  5153 * Pure: generic 'sym' attribute which declares a rule both as pure
  5154 'elim?' and for the 'symmetric' operation;
  5155 
  5156 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5157 text; the fixed correlation with particular command syntax has been
  5158 discontinued;
  5159 
  5160 * Pure: new method 'rules' is particularly well-suited for proof
  5161 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5162 but often produces more compact proof terms with less detours;
  5163 
  5164 * Pure/Provers/classical: simplified integration with pure rule
  5165 attributes and methods; the classical "intro?/elim?/dest?"
  5166 declarations coincide with the pure ones; the "rule" method no longer
  5167 includes classically swapped intros; "intro" and "elim" methods no
  5168 longer pick rules from the context; also got rid of ML declarations
  5169 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5170 INCOMPATIBILITY;
  5171 
  5172 * Provers/classical: attribute 'swapped' produces classical inversions
  5173 of introduction rules;
  5174 
  5175 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5176 rules instead of full simplifier context; 'iff' attribute handles
  5177 conditional rules;
  5178 
  5179 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5180 
  5181 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5182 "(permissive)" option to recover old behavior;
  5183 
  5184 * HOL: 'inductive' no longer features separate (collective) attributes
  5185 for 'intros' (was found too confusing);
  5186 
  5187 * HOL: properly declared induction rules less_induct and
  5188 wf_induct_rule;
  5189 
  5190 
  5191 *** HOL ***
  5192 
  5193 * HOL: moved over to sane numeral syntax; the new policy is as
  5194 follows:
  5195 
  5196   - 0 and 1 are polymorphic constants, which are defined on any
  5197   numeric type (nat, int, real etc.);
  5198 
  5199   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5200   binary representation internally;
  5201 
  5202   - type nat has special constructor Suc, and generally prefers Suc 0
  5203   over 1::nat and Suc (Suc 0) over 2::nat;
  5204 
  5205 This change may cause significant problems of INCOMPATIBILITY; here
  5206 are some hints on converting existing sources:
  5207 
  5208   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5209   entities, so expressions involving "-" (unary or binary minus) need
  5210   to be spaced properly;
  5211 
  5212   - existing occurrences of "1" may need to be constraint "1::nat" or
  5213   even replaced by Suc 0; similar for old "2";
  5214 
  5215   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5216 
  5217   - remove all special provisions on numerals in proofs;
  5218 
  5219 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5220 representation (depends on bin_arith_simps in the default context);
  5221 
  5222 * HOL: symbolic syntax for x^2 (numeral 2);
  5223 
  5224 * HOL: the class of all HOL types is now called "type" rather than
  5225 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5226 in axclass/classes, instance/arities, and (usually rare) occurrences
  5227 in typings (of consts etc.); internally the class is called
  5228 "HOL.type", ML programs should refer to HOLogic.typeS;
  5229 
  5230 * HOL/record package improvements:
  5231   - new derived operations "fields" to build a partial record section,
  5232     "extend" to promote a fixed record to a record scheme, and
  5233     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5234     declared as simp by default;
  5235   - shared operations ("more", "fields", etc.) now need to be always
  5236     qualified) --- potential INCOMPATIBILITY;
  5237   - removed "make_scheme" operations (use "make" with "extend") --
  5238     INCOMPATIBILITY;
  5239   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5240   - provides cases/induct rules for use with corresponding Isar
  5241     methods (for concrete records, record schemes, concrete more
  5242     parts, and schematic more parts -- in that order);
  5243   - internal definitions directly based on a light-weight abstract
  5244     theory of product types over typedef rather than datatype;
  5245 
  5246 * HOL: generic code generator for generating executable ML code from
  5247 specifications; specific support for HOL constructs such as inductive
  5248 datatypes and sets, as well as recursive functions; can be invoked
  5249 via 'generate_code' theory section;
  5250 
  5251 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5252 
  5253 * HOL: consolidated and renamed several theories.  In particular:
  5254         Ord.thy has been absorbed into HOL.thy
  5255         String.thy has been absorbed into List.thy
  5256 
  5257 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5258 (beware of argument permutation!);
  5259 
  5260 * HOL: linorder_less_split superseded by linorder_cases;
  5261 
  5262 * HOL/List: "nodups" renamed to "distinct";
  5263 
  5264 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5265 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5266   - Ex_def has changed, now need to use some_eq_ex
  5267 
  5268 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5269 in this (rare) case use:
  5270 
  5271   delSWrapper "split_all_tac"
  5272   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5273 
  5274 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5275 MAY FAIL;
  5276 
  5277 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5278 Isabelle's type classes, ^ on functions and relations has too general
  5279 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5280 necessary to attach explicit type constraints;
  5281 
  5282 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5283 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5284 renamed accordingly (eg "compI" -> "rel_compI").
  5285 
  5286 * HOL: syntax translations now work properly with numerals and records
  5287 expressions;
  5288 
  5289 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5290 of "lam" -- INCOMPATIBILITY;
  5291 
  5292 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5293 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5294 renamed "Product_Type.unit";
  5295 
  5296 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5297 
  5298 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5299 the "cases" method);
  5300 
  5301 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5302 Florian Kammller);
  5303 
  5304 * HOL/IMP: updated and converted to new-style theory format; several
  5305 parts turned into readable document, with proper Isar proof texts and
  5306 some explanations (by Gerwin Klein);
  5307 
  5308 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5309 
  5310 * HOL-Hyperreal is now a logic image;
  5311 
  5312 
  5313 *** HOLCF ***
  5314 
  5315 * Isar: consts/constdefs supports mixfix syntax for continuous
  5316 operations;
  5317 
  5318 * Isar: domain package adapted to new-style theory format, e.g. see
  5319 HOLCF/ex/Dnat.thy;
  5320 
  5321 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5322 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5323 lift.induct_tac, always use UU instead of Undef;
  5324 
  5325 * HOLCF/IMP: updated and converted to new-style theory;
  5326 
  5327 
  5328 *** ZF ***
  5329 
  5330 * Isar: proper integration of logic-specific tools and packages,
  5331 including theory commands '(co)inductive', '(co)datatype',
  5332 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5333 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5334 
  5335 * theory Main no longer includes AC; for the Axiom of Choice, base
  5336 your theory on Main_ZFC;
  5337 
  5338 * the integer library now covers quotients and remainders, with many
  5339 laws relating division to addition, multiplication, etc.;
  5340 
  5341 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5342 typeless version of the formalism;
  5343 
  5344 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5345 format;
  5346 
  5347 * ZF/Induct: new directory for examples of inductive definitions,
  5348 including theory Multiset for multiset orderings; converted to
  5349 new-style theory format;
  5350 
  5351 * ZF: many new theorems about lists, ordinals, etc.;
  5352 
  5353 
  5354 *** General ***
  5355 
  5356 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5357 variable proof controls level of detail: 0 = no proofs (only oracle
  5358 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5359 also ref manual for further ML interfaces;
  5360 
  5361 * Pure/axclass: removed obsolete ML interface
  5362 goal_subclass/goal_arity;
  5363 
  5364 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5365 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5366 separate tokens, so expressions involving minus need to be spaced
  5367 properly;
  5368 
  5369 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5370 rather than "infixl" or "infixr";
  5371 
  5372 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5373 sort constraint specifications in type inference; e.g. "x::_::foo"
  5374 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5375 type variable);
  5376 
  5377 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5378 control output of nested => (types); the default behavior is
  5379 "type_brackets";
  5380 
  5381 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5382 tokens into AST constants;
  5383 
  5384 * Pure/syntax: prefer later declarations of translations and print
  5385 translation functions; potential INCOMPATIBILITY: need to reverse
  5386 multiple declarations for same syntax element constant;
  5387 
  5388 * Pure/show_hyps reset by default (in accordance to existing Isar
  5389 practice);
  5390 
  5391 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5392 addSafter;
  5393 
  5394 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5395 as well;
  5396 
  5397 * system: tested support for MacOS X; should be able to get Isabelle +
  5398 Proof General to work in a plain Terminal after installing Poly/ML
  5399 (e.g. from the Isabelle distribution area) and GNU bash alone
  5400 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5401 support requires further installations, e.g. from
  5402 http://fink.sourceforge.net/);
  5403 
  5404 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5405 
  5406 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5407 of 40 MB), cf. ML_OPTIONS;
  5408 
  5409 * system: Proof General keywords specification is now part of the
  5410 Isabelle distribution (see etc/isar-keywords.el);
  5411 
  5412 * system: support for persistent Proof General sessions (refrain from
  5413 outdating all loaded theories on startup); user may create writable
  5414 logic images like this: ``isabelle -q HOL Test'';
  5415 
  5416 * system: smart selection of Isabelle process versus Isabelle
  5417 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5418 run both "isabelle" and "Isabelle" even if file names are badly
  5419 damaged (executable inspects the case of the first letter of its own
  5420 name); added separate "isabelle-process" and "isabelle-interface";
  5421 
  5422 * system: refrain from any attempt at filtering input streams; no
  5423 longer support ``8bit'' encoding of old isabelle font, instead proper
  5424 iso-latin characters may now be used; the related isatools
  5425 "symbolinput" and "nonascii" have disappeared as well;
  5426 
  5427 * system: removed old "xterm" interface (the print modes "xterm" and
  5428 "xterm_color" are still available for direct use in a suitable
  5429 terminal);
  5430 
  5431 
  5432 
  5433 New in Isabelle99-2 (February 2001)
  5434 -----------------------------------
  5435 
  5436 *** Overview of INCOMPATIBILITIES ***
  5437 
  5438 * HOL: please note that theories in the Library and elsewhere often use the
  5439 new-style (Isar) format; to refer to their theorems in an ML script you must
  5440 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5441 
  5442 * HOL: inductive package no longer splits induction rule aggressively,
  5443 but only as far as specified by the introductions given; the old
  5444 format may be recovered via ML function complete_split_rule or attribute
  5445 'split_rule (complete)';
  5446 
  5447 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5448 gfp_Tarski to gfp_unfold;
  5449 
  5450 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5451 
  5452 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5453 relation); infix "^^" has been renamed "``"; infix "``" has been
  5454 renamed "`"; "univalent" has been renamed "single_valued";
  5455 
  5456 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5457 operation;
  5458 
  5459 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5460 
  5461 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5462 
  5463 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5464 consequence, it is no longer monotonic wrt. the local goal context
  5465 (which is now passed through the inductive cases);
  5466 
  5467 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5468 \<gg> to \<ggreater>;
  5469 
  5470 
  5471 *** Document preparation ***
  5472 
  5473 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5474 available: are "it" for near math-mode best-style output, "sl" for
  5475 slanted text style, and "tt" for plain type-writer; if no
  5476 \isabellestyle command is given, output is according to slanted
  5477 type-writer);
  5478 
  5479 * support sub/super scripts (for single symbols only), input syntax is
  5480 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5481 
  5482 * some more standard symbols; see Appendix A of the system manual for
  5483 the complete list of symbols defined in isabellesym.sty;
  5484 
  5485 * improved isabelle style files; more abstract symbol implementation
  5486 (should now use \isamath{...} and \isatext{...} in custom symbol
  5487 definitions);
  5488 
  5489 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5490 state; Note that presentation of goal states does not conform to
  5491 actual human-readable proof documents.  Please do not include goal
  5492 states into document output unless you really know what you are doing!
  5493 
  5494 * proper indentation of antiquoted output with proportional LaTeX
  5495 fonts;
  5496 
  5497 * no_document ML operator temporarily disables LaTeX document
  5498 generation;
  5499 
  5500 * isatool unsymbolize tunes sources for plain ASCII communication;
  5501 
  5502 
  5503 *** Isar ***
  5504 
  5505 * Pure: Isar now suffers initial goal statements to contain unbound
  5506 schematic variables (this does not conform to actual readable proof
  5507 documents, due to unpredictable outcome and non-compositional proof
  5508 checking); users who know what they are doing may use schematic goals
  5509 for Prolog-style synthesis of proven results;
  5510 
  5511 * Pure: assumption method (an implicit finishing) now handles actual
  5512 rules as well;
  5513 
  5514 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5515 initial goal, declare "that" only as Pure intro (only for single
  5516 steps); the "that" rule assumption may now be involved in implicit
  5517 finishing, thus ".." becomes a feasible for trivial obtains;
  5518 
  5519 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5520 instance proofs may be performed by "..";
  5521 
  5522 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5523 statements as well;
  5524 
  5525 * Pure: more robust selection of calculational rules;
  5526 
  5527 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5528 rule (as well as the assumption rule);
  5529 
  5530 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5531 lemmas, using the graph browser tool;
  5532 
  5533 * Pure: predict failure of "show" in interactive mode;
  5534 
  5535 * Pure: 'thms_containing' now takes actual terms as arguments;
  5536 
  5537 * HOL: improved method 'induct' --- now handles non-atomic goals
  5538 (potential INCOMPATIBILITY); tuned error handling;
  5539 
  5540 * HOL: cases and induct rules now provide explicit hints about the
  5541 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5542 any remaining facts are inserted into the goal verbatim;
  5543 
  5544 * HOL: local contexts (aka cases) may now contain term bindings as
  5545 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5546 the result to be shown in each case;
  5547 
  5548 * HOL: added 'recdef_tc' command;
  5549 
  5550 * isatool convert assists in eliminating legacy ML scripts;
  5551 
  5552 
  5553 *** HOL ***
  5554 
  5555 * HOL/Library: a collection of generic theories to be used together
  5556 with main HOL; the theory loader path already includes this directory
  5557 by default; the following existing theories have been moved here:
  5558 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5559 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5560 
  5561 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5562 modelling and verification task performed in Isabelle/HOL +
  5563 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5564 
  5565 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5566 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5567 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5568 'domain', this makes the theory consistent with mathematical
  5569 literature;
  5570 
  5571 * HOL basics: added overloaded operations "inverse" and "divide"
  5572 (infix "/"), syntax for generic "abs" operation, generic summation
  5573 operator \<Sum>;
  5574 
  5575 * HOL/typedef: simplified package, provide more useful rules (see also
  5576 HOL/subset.thy);
  5577 
  5578 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5579 now expressed as a proper nested rule (old-style tactic scripts may
  5580 require atomize_strip_tac to cope with non-atomic premises);
  5581 
  5582 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5583 to "split_conv" (old name still available for compatibility);
  5584 
  5585 * HOL: improved concrete syntax for strings (e.g. allows translation
  5586 rules with string literals);
  5587 
  5588 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5589  and Fleuriot's mechanization of analysis, including the transcendental
  5590  functions for the reals;
  5591 
  5592 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5593 
  5594 
  5595 *** CTT ***
  5596 
  5597 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5598 "lam" is displayed as TWO lambda-symbols
  5599 
  5600 * CTT: theory Main now available, containing everything (that is, Bool
  5601 and Arith);
  5602 
  5603 
  5604 *** General ***
  5605 
  5606 * Pure: the Simplifier has been implemented properly as a derived rule
  5607 outside of the actual kernel (at last!); the overall performance
  5608 penalty in practical applications is about 50%, while reliability of
  5609 the Isabelle inference kernel has been greatly improved;
  5610 
  5611 * print modes "brackets" and "no_brackets" control output of nested =>
  5612 (types) and ==> (props); the default behaviour is "brackets";
  5613 
  5614 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5615 as assumptions as well;
  5616 
  5617 * system: support Poly/ML 4.0;
  5618 
  5619 * system: isatool install handles KDE version 1 or 2;
  5620 
  5621 
  5622 
  5623 New in Isabelle99-1 (October 2000)
  5624 ----------------------------------
  5625 
  5626 *** Overview of INCOMPATIBILITIES ***
  5627 
  5628 * HOL: simplification of natural numbers is much changed; to partly
  5629 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5630 issue the following ML commands:
  5631 
  5632   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5633   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5634 
  5635 * HOL: simplification no longer dives into case-expressions; this is
  5636 controlled by "t.weak_case_cong" for each datatype t;
  5637 
  5638 * HOL: nat_less_induct renamed to less_induct;
  5639 
  5640 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5641 fixsome to patch .thy and .ML sources automatically;
  5642 
  5643   select_equality  -> some_equality
  5644   select_eq_Ex     -> some_eq_ex
  5645   selectI2EX       -> someI2_ex
  5646   selectI2         -> someI2
  5647   selectI          -> someI
  5648   select1_equality -> some1_equality
  5649   Eps_sym_eq       -> some_sym_eq_trivial
  5650   Eps_eq           -> some_eq_trivial
  5651 
  5652 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5653 
  5654 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5655 instead);
  5656 
  5657 * HOL: the recursion equations generated by 'recdef' are now called
  5658 f.simps instead of f.rules;
  5659 
  5660 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5661 
  5662 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5663 sometimes be needed;
  5664 
  5665 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5666 
  5667 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5668 
  5669 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5670 product is now "<*>" instead of "Times"; the lexicographic product is
  5671 now "<*lex*>" instead of "**";
  5672 
  5673 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5674 of main HOL, but was unused); better use HOL's datatype package;
  5675 
  5676 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5677 the old syntax may be recovered as follows:
  5678 
  5679   syntax (symbols)
  5680     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5681       (infixl "\\<oplus>" 100)
  5682 
  5683 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5684 
  5685 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5686 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5687 internally;
  5688 
  5689 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5690 changed from A/r to A//r;
  5691 
  5692 * ZF: new treatment of arithmetic (nat & int) may break some old
  5693 proofs;
  5694 
  5695 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5696 rulify -> rule_format, elimify -> elim_format, ...);
  5697 
  5698 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5699 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5700 should have to change intro!! to intro? only); replaced "delrule" by
  5701 "rule del";
  5702 
  5703 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5704 
  5705 * Provers: strengthened force_tac by using new first_best_tac;
  5706 
  5707 * LaTeX document preparation: several changes of isabelle.sty (see
  5708 lib/texinputs);
  5709 
  5710 
  5711 *** Document preparation ***
  5712 
  5713 * formal comments (text blocks etc.) in new-style theories may now
  5714 contain antiquotations of thm/prop/term/typ/text to be presented
  5715 according to latex print mode; concrete syntax is like this:
  5716 @{term[show_types] "f(x) = a + x"};
  5717 
  5718 * isatool mkdir provides easy setup of Isabelle session directories,
  5719 including proper document sources;
  5720 
  5721 * generated LaTeX sources are now deleted after successful run
  5722 (isatool document -c); may retain a copy somewhere else via -D option
  5723 of isatool usedir;
  5724 
  5725 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5726 style files, achieving self-contained LaTeX sources and simplifying
  5727 LaTeX debugging;
  5728 
  5729 * old-style theories now produce (crude) LaTeX output as well;
  5730 
  5731 * browser info session directories are now self-contained (may be put
  5732 on WWW server seperately); improved graphs of nested sessions; removed
  5733 graph for 'all sessions';
  5734 
  5735 * several improvements in isabelle style files; \isabellestyle{it}
  5736 produces fake math mode output; \isamarkupheader is now \section by
  5737 default; see lib/texinputs/isabelle.sty etc.;
  5738 
  5739 
  5740 *** Isar ***
  5741 
  5742 * Isar/Pure: local results and corresponding term bindings are now
  5743 subject to Hindley-Milner polymorphism (similar to ML); this
  5744 accommodates incremental type-inference very nicely;
  5745 
  5746 * Isar/Pure: new derived language element 'obtain' supports
  5747 generalized existence reasoning;
  5748 
  5749 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5750 support accumulation of results, without applying any rules yet;
  5751 useful to collect intermediate results without explicit name
  5752 references, and for use with transitivity rules with more than 2
  5753 premises;
  5754 
  5755 * Isar/Pure: scalable support for case-analysis type proofs: new
  5756 'case' language element refers to local contexts symbolically, as
  5757 produced by certain proof methods; internally, case names are attached
  5758 to theorems as "tags";
  5759 
  5760 * Isar/Pure: theory command 'hide' removes declarations from
  5761 class/type/const name spaces;
  5762 
  5763 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5764 indicate potential overloading;
  5765 
  5766 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5767 
  5768 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5769 "{a,b,c}" instead of {a,b,c};
  5770 
  5771 * Isar/Pure now provides its own version of intro/elim/dest
  5772 attributes; useful for building new logics, but beware of confusion
  5773 with the version in Provers/classical;
  5774 
  5775 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5776 case name 'antecedent';
  5777 
  5778 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5779 to the current context is now done automatically);
  5780 
  5781 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5782 for definining proof methods in ML;
  5783 
  5784 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5785 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5786 most cases, one should have to change intro!! to intro? only);
  5787 replaced "delrule" by "rule del";
  5788 
  5789 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5790 'symmetric' attribute (the latter supercedes [RS sym]);
  5791 
  5792 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5793 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5794 well (including splits);
  5795 
  5796 * Isar/Provers: Simplifier and Classical methods now support all kind
  5797 of modifiers used in the past, including 'cong', 'iff', etc.
  5798 
  5799 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5800 of Simplifier and Classical reasoner);
  5801 
  5802 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5803 now support named cases; major packages (inductive, datatype, primrec,
  5804 recdef) support case names and properly name parameters;
  5805 
  5806 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5807 monotonicity conditions are extracted to be proven at end of
  5808 calculations;
  5809 
  5810 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5811 method anyway;
  5812 
  5813 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5814 split_if split_if_asm; datatype package provides theorems foo.splits =
  5815 foo.split foo.split_asm for each datatype;
  5816 
  5817 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5818 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5819 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5820 use "(cases (simplified))" method in proper proof texts);
  5821 
  5822 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5823 
  5824 * Isar: names of theorems etc. may be natural numbers as well;
  5825 
  5826 * Isar: 'pr' command: optional arguments for goals_limit and
  5827 ProofContext.prems_limit; no longer prints theory contexts, but only
  5828 proof states;
  5829 
  5830 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5831 additional print modes to be specified; e.g. "pr(latex)" will print
  5832 proof state according to the Isabelle LaTeX style;
  5833 
  5834 * Isar: improved support for emulating tactic scripts, including proof
  5835 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5836 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5837 (for HOL datatypes);
  5838 
  5839 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5840 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5841 'proof method scripts' have to be in depth-first order;
  5842 
  5843 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5844 
  5845 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5846 should instead use individual commands for printing items
  5847 (print_commands, print_methods etc.);
  5848 
  5849 * Isar: added 'nothing' --- the empty list of theorems;
  5850 
  5851 
  5852 *** HOL ***
  5853 
  5854 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5855 corresponding virtual machine and a specification of its bytecode
  5856 verifier and a lightweight bytecode verifier, including proofs of
  5857 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5858 Cornelia Pusch (see also the homepage of project Bali at
  5859 http://isabelle.in.tum.de/Bali/);
  5860 
  5861 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5862 Clemens Ballarin;
  5863 
  5864 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5865 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5866 Rasmussen;
  5867 
  5868 * HOL/Lattice: fundamental concepts of lattice theory and order
  5869 structures, including duals, properties of bounds versus algebraic
  5870 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5871 Theorem for complete lattices etc.; may also serve as a demonstration
  5872 for abstract algebraic reasoning using axiomatic type classes, and
  5873 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5874 
  5875 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5876 von Oheimb;
  5877 
  5878 * HOL/IMPP: extension of IMP with local variables and mutually
  5879 recursive procedures, by David von Oheimb;
  5880 
  5881 * HOL/Lambda: converted into new-style theory and document;
  5882 
  5883 * HOL/ex/Multiquote: example of multiple nested quotations and
  5884 anti-quotations -- basically a generalized version of de-Bruijn
  5885 representation; very useful in avoiding lifting of operations;
  5886 
  5887 * HOL/record: added general record equality rule to simpset; fixed
  5888 select-update simplification procedure to handle extended records as
  5889 well; admit "r" as field name;
  5890 
  5891 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5892 other numeric types and also as the identity of groups, rings, etc.;
  5893 
  5894 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5895 Types nat and int belong to this axclass;
  5896 
  5897 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5898    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5899    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5900   two terms #m*u and #n*u are replaced by #(m+n)*u
  5901     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5902   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5903     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5904 
  5905 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5906 powerful prover for predicate logic but knows nothing of clasets; see
  5907 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5908 
  5909 * HOL: new version of "case_tac" subsumes both boolean case split and
  5910 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5911 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5912 
  5913 * HOL: simplification no longer dives into case-expressions: only the
  5914 selector expression is simplified, but not the remaining arms; to
  5915 enable full simplification of case-expressions for datatype t, you may
  5916 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5917 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5918 
  5919 * HOL/recdef: the recursion equations generated by 'recdef' for
  5920 function 'f' are now called f.simps instead of f.rules; if all
  5921 termination conditions are proved automatically, these simplification
  5922 rules are added to the simpset, as in primrec; rules may be named
  5923 individually as well, resulting in a separate list of theorems for
  5924 each equation;
  5925 
  5926 * HOL/While is a new theory that provides a while-combinator. It
  5927 permits the definition of tail-recursive functions without the
  5928 provision of a termination measure. The latter is necessary once the
  5929 invariant proof rule for while is applied.
  5930 
  5931 * HOL: new (overloaded) notation for the set of elements below/above
  5932 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5933 
  5934 * HOL: theorems impI, allI, ballI bound as "strip";
  5935 
  5936 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5937 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5938 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5939 
  5940 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5941 
  5942 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5943 main HOL, but was unused);
  5944 
  5945 * HOL: fewer consts declared as global (e.g. have to refer to
  5946 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5947 
  5948 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5949 in case of overlap with user translations (e.g. judgements over
  5950 tuples); (note that the underlying logical represenation is still
  5951 bogus);
  5952 
  5953 
  5954 *** ZF ***
  5955 
  5956 * ZF: simplification automatically cancels common terms in arithmetic
  5957 expressions over nat and int;
  5958 
  5959 * ZF: new treatment of nat to minimize type-checking: all operators
  5960 coerce their operands to a natural number using the function natify,
  5961 making the algebraic laws unconditional;
  5962 
  5963 * ZF: as above, for int: operators coerce their operands to an integer
  5964 using the function intify;
  5965 
  5966 * ZF: the integer library now contains many of the usual laws for the
  5967 orderings, including $<=, and monotonicity laws for $+ and $*;
  5968 
  5969 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5970 simplification;
  5971 
  5972 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5973 to the simplifier and classical reasoner simultaneously;
  5974 
  5975 
  5976 *** General ***
  5977 
  5978 * Provers: blast_tac now handles actual object-logic rules as
  5979 assumptions; note that auto_tac uses blast_tac internally as well;
  5980 
  5981 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5982 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5983 
  5984 * Provers: delrules now handles destruct rules as well (no longer need
  5985 explicit make_elim);
  5986 
  5987 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5988   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5989 use instead the strong form,
  5990   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5991 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5992 from destruct-rules;
  5993 
  5994 * Provers: Simplifier.easy_setup provides a fast path to basic
  5995 Simplifier setup for new object-logics;
  5996 
  5997 * Pure: AST translation rules no longer require constant head on LHS;
  5998 
  5999 * Pure: improved name spaces: ambiguous output is qualified; support
  6000 for hiding of names;
  6001 
  6002 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6003 XSYMBOL_HOME; no longer need to do manual configuration in most
  6004 situations;
  6005 
  6006 * system: compression of ML heaps images may now be controlled via -c
  6007 option of isabelle and isatool usedir (currently only observed by
  6008 Poly/ML);
  6009 
  6010 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6011 useful for remote X11);
  6012 
  6013 * system: provide TAGS file for Isabelle sources;
  6014 
  6015 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6016 order;
  6017 
  6018 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6019 timing flag supersedes proof_timing and Toplevel.trace;
  6020 
  6021 * ML: new combinators |>> and |>>> for incremental transformations
  6022 with secondary results (e.g. certain theory extensions):
  6023 
  6024 * ML: PureThy.add_defs gets additional argument to indicate potential
  6025 overloading (usually false);
  6026 
  6027 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6028 results;
  6029 
  6030 
  6031 
  6032 New in Isabelle99 (October 1999)
  6033 --------------------------------
  6034 
  6035 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6036 
  6037 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6038 are no longer simplified.  (This allows the simplifier to unfold recursive
  6039 functional programs.)  To restore the old behaviour, declare
  6040 
  6041     Delcongs [if_weak_cong];
  6042 
  6043 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6044 complement;
  6045 
  6046 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6047 
  6048 * HOL/datatype: mutual_induct_tac no longer exists --
  6049   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6050 
  6051 * HOL/typedef: fixed type inference for representing set; type
  6052 arguments now have to occur explicitly on the rhs as type constraints;
  6053 
  6054 * ZF: The con_defs part of an inductive definition may no longer refer
  6055 to constants declared in the same theory;
  6056 
  6057 * HOL, ZF: the function mk_cases, generated by the inductive
  6058 definition package, has lost an argument.  To simplify its result, it
  6059 uses the default simpset instead of a supplied list of theorems.
  6060 
  6061 * HOL/List: the constructors of type list are now Nil and Cons;
  6062 
  6063 * Simplifier: the type of the infix ML functions
  6064         setSSolver addSSolver setSolver addSolver
  6065 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6066 for packaging solvers. A solver is created via
  6067         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6068 where the string argument is only a comment.
  6069 
  6070 
  6071 *** Proof tools ***
  6072 
  6073 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6074 decision procedure for linear arithmetic. Currently it is used for
  6075 types `nat', `int', and `real' in HOL (see below); it can, should and
  6076 will be instantiated for other types and logics as well.
  6077 
  6078 * The simplifier now accepts rewrite rules with flexible heads, eg
  6079      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6080   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6081   matching.
  6082 
  6083 
  6084 *** General ***
  6085 
  6086 * New Isabelle/Isar subsystem provides an alternative to traditional
  6087 tactical theorem proving; together with the ProofGeneral/isar user
  6088 interface it offers an interactive environment for developing human
  6089 readable proof documents (Isar == Intelligible semi-automated
  6090 reasoning); for further information see isatool doc isar-ref,
  6091 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6092 
  6093 * improved and simplified presentation of theories: better HTML markup
  6094 (including colors), graph views in several sizes; isatool usedir now
  6095 provides a proper interface for user theories (via -P option); actual
  6096 document preparation based on (PDF)LaTeX is available as well (for
  6097 new-style theories only); see isatool doc system for more information;
  6098 
  6099 * native support for Proof General, both for classic Isabelle and
  6100 Isabelle/Isar;
  6101 
  6102 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  6103 using the graph browser tool;
  6104 
  6105 * Isabelle manuals now also available as PDF;
  6106 
  6107 * theory loader rewritten from scratch (may not be fully
  6108 bug-compatible); old loadpath variable has been replaced by show_path,
  6109 add_path, del_path, reset_path functions; new operations such as
  6110 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6111 isatool doc ref);
  6112 
  6113 * improved isatool install: option -k creates KDE application icon,
  6114 option -p DIR installs standalone binaries;
  6115 
  6116 * added ML_PLATFORM setting (useful for cross-platform installations);
  6117 more robust handling of platform specific ML images for SML/NJ;
  6118 
  6119 * the settings environment is now statically scoped, i.e. it is never
  6120 created again in sub-processes invoked from isabelle, isatool, or
  6121 Isabelle;
  6122 
  6123 * path element specification '~~' refers to '$ISABELLE_HOME';
  6124 
  6125 * in locales, the "assumes" and "defines" parts may be omitted if
  6126 empty;
  6127 
  6128 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  6129 long arrows);
  6130 
  6131 * new print_mode "HTML";
  6132 
  6133 * new flag show_tags controls display of tags of theorems (which are
  6134 basically just comments that may be attached by some tools);
  6135 
  6136 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  6137 mode and goal output format:
  6138 
  6139 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  6140 244c244
  6141 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  6142 ---
  6143 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  6144 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  6145 181c181
  6146 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  6147 ---
  6148 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  6149 
  6150 * function bind_thms stores lists of theorems (cf. bind_thm);
  6151 
  6152 * new shorthand tactics ftac, eatac, datac, fatac;
  6153 
  6154 * qed (and friends) now accept "" as result name; in that case the
  6155 theorem is not stored, but proper checks and presentation of the
  6156 result still apply;
  6157 
  6158 * theorem database now also indexes constants "Trueprop", "all",
  6159 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  6160 
  6161 
  6162 *** HOL ***
  6163 
  6164 ** HOL arithmetic **
  6165 
  6166 * There are now decision procedures for linear arithmetic over nat and
  6167 int:
  6168 
  6169 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  6170 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  6171 are treated as atomic; subformulae not involving type `nat' or `int'
  6172 are ignored; quantified subformulae are ignored unless they are
  6173 positive universal or negative existential. The tactic has to be
  6174 invoked by hand and can be a little bit slow. In particular, the
  6175 running time is exponential in the number of occurrences of `min' and
  6176 `max', and `-' on `nat'.
  6177 
  6178 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  6179 (negated) (in)equalities among the premises and the conclusion into
  6180 account (i.e. no compound formulae) and does not know about `min' and
  6181 `max', and `-' on `nat'. It is fast and is used automatically by the
  6182 simplifier.
  6183 
  6184 NB: At the moment, these decision procedures do not cope with mixed
  6185 nat/int formulae where the two parts interact, such as `m < n ==>
  6186 int(m) < int(n)'.
  6187 
  6188 * HOL/Numeral provides a generic theory of numerals (encoded
  6189 efficiently as bit strings); setup for types nat/int/real is in place;
  6190 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  6191 int, existing theories and proof scripts may require a few additional
  6192 type constraints;
  6193 
  6194 * integer division and remainder can now be performed on constant
  6195 arguments;
  6196 
  6197 * many properties of integer multiplication, division and remainder
  6198 are now available;
  6199 
  6200 * An interface to the Stanford Validity Checker (SVC) is available through the
  6201 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  6202 are proved automatically.  SVC must be installed separately, and its results
  6203 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  6204 invocation of the underlying oracle).  For SVC see
  6205   http://verify.stanford.edu/SVC
  6206 
  6207 * IsaMakefile: the HOL-Real target now builds an actual image;
  6208 
  6209 
  6210 ** HOL misc **
  6211 
  6212 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  6213 (in Isabelle/Isar) -- by Gertrud Bauer;
  6214 
  6215 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  6216 analysis for assembly languages with subtypes;
  6217 
  6218 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  6219 -- avoids syntactic ambiguities and treats state, transition, and
  6220 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  6221 changed syntax and (many) tactics;
  6222 
  6223 * HOL/inductive: Now also handles more general introduction rules such
  6224   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  6225   theorems are now maintained within the theory (maintained via the
  6226   "mono" attribute);
  6227 
  6228