NEWS
author wenzelm
Mon, 21 Jun 2010 17:41:57 +0200
changeset 37484 b7821e89fb79
parent 37417 037ee7b712b2
parent 37481 35815ce9218a
child 37553 c62aa9281101
child 37595 9591362629e3
permissions -rw-r--r--
merged, resolving conflicts in doc-src/IsarRef/Thy/HOL_Specific.thy;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** HOL ***
     8 
     9 * Some previously unqualified names have been qualified:
    10 
    11   types
    12     nat ~> Nat.nat
    13     * ~> Product_Type,*
    14     + ~> Sum_Type.+
    15 
    16   constants
    17     Ball ~> Set.Ball
    18     Bex ~> Set.Bex
    19     Suc ~> Nat.Suc
    20     Pair ~> Product_Type.Pair
    21     fst ~> Product_Type.fst
    22     snd ~> Product_Type.snd
    23     split ~> Product_Type.split
    24     curry ~> Product_Type.curry
    25 
    26 INCOMPATIBILITY.
    27 
    28 * Removed simplifier congruence rule of "prod_case", as has for long
    29 been the case with "split".
    30 
    31 * Datatype package: theorems generated for executable equality
    32 (class eq) carry proper names and are treated as default code
    33 equations.
    34 
    35 * List.thy: use various operations from the Haskell prelude when
    36 generating Haskell code.
    37 
    38 * code_simp.ML: simplification with rules determined by
    39 code generator.
    40 
    41 * code generator: do not print function definitions for case
    42 combinators any longer.
    43 
    44 
    45 
    46 New in Isabelle2009-2 (June 2010)
    47 ---------------------------------
    48 
    49 *** General ***
    50 
    51 * Authentic syntax for *all* logical entities (type classes, type
    52 constructors, term constants): provides simple and robust
    53 correspondence between formal entities and concrete syntax.  Within
    54 the parse tree / AST representations, "constants" are decorated by
    55 their category (class, type, const) and spelled out explicitly with
    56 their full internal name.
    57 
    58 Substantial INCOMPATIBILITY concerning low-level syntax declarations
    59 and translations (translation rules and translation functions in ML).
    60 Some hints on upgrading:
    61 
    62   - Many existing uses of 'syntax' and 'translations' can be replaced
    63     by more modern 'type_notation', 'notation' and 'abbreviation',
    64     which are independent of this issue.
    65 
    66   - 'translations' require markup within the AST; the term syntax
    67     provides the following special forms:
    68 
    69       CONST c   -- produces syntax version of constant c from context
    70       XCONST c  -- literally c, checked as constant from context
    71       c         -- literally c, if declared by 'syntax'
    72 
    73     Plain identifiers are treated as AST variables -- occasionally the
    74     system indicates accidental variables via the error "rhs contains
    75     extra variables".
    76 
    77     Type classes and type constructors are marked according to their
    78     concrete syntax.  Some old translations rules need to be written
    79     for the "type" category, using type constructor application
    80     instead of pseudo-term application of the default category
    81     "logic".
    82 
    83   - 'parse_translation' etc. in ML may use the following
    84     antiquotations:
    85 
    86       @{class_syntax c}   -- type class c within parse tree / AST
    87       @{term_syntax c}    -- type constructor c within parse tree / AST
    88       @{const_syntax c}   -- ML version of "CONST c" above
    89       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
    90 
    91   - Literal types within 'typed_print_translations', i.e. those *not*
    92     represented as pseudo-terms are represented verbatim.  Use @{class
    93     c} or @{type_name c} here instead of the above syntax
    94     antiquotations.
    95 
    96 Note that old non-authentic syntax was based on unqualified base
    97 names, so all of the above "constant" names would coincide.  Recall
    98 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
    99 diagnose syntax problems.
   100 
   101 * Type constructors admit general mixfix syntax, not just infix.
   102 
   103 * Concrete syntax may be attached to local entities without a proof
   104 body, too.  This works via regular mixfix annotations for 'fix',
   105 'def', 'obtain' etc. or via the explicit 'write' command, which is
   106 similar to the 'notation' command in theory specifications.
   107 
   108 * Discontinued unnamed infix syntax (legacy feature for many years) --
   109 need to specify constant name and syntax separately.  Internal ML
   110 datatype constructors have been renamed from InfixName to Infix etc.
   111 Minor INCOMPATIBILITY.
   112 
   113 * Schematic theorem statements need to be explicitly markup as such,
   114 via commands 'schematic_lemma', 'schematic_theorem',
   115 'schematic_corollary'.  Thus the relevance of the proof is made
   116 syntactically clear, which impacts performance in a parallel or
   117 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   118 
   119 * Use of cumulative prems via "!" in some proof methods has been
   120 discontinued (old legacy feature).
   121 
   122 * References 'trace_simp' and 'debug_simp' have been replaced by
   123 configuration options stored in the context. Enabling tracing (the
   124 case of debugging is similar) in proofs works via
   125 
   126   using [[trace_simp = true]]
   127 
   128 Tracing is then active for all invocations of the simplifier in
   129 subsequent goal refinement steps. Tracing may also still be enabled or
   130 disabled via the ProofGeneral settings menu.
   131 
   132 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   133 'hide_fact' replace the former 'hide' KIND command.  Minor
   134 INCOMPATIBILITY.
   135 
   136 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   137 more efficient than combinations with -q1 or -q2.
   138 
   139 
   140 *** Pure ***
   141 
   142 * Proofterms record type-class reasoning explicitly, using the
   143 "unconstrain" operation internally.  This eliminates all sort
   144 constraints from a theorem and proof, introducing explicit
   145 OFCLASS-premises.  On the proof term level, this operation is
   146 automatically applied at theorem boundaries, such that closed proofs
   147 are always free of sort constraints.  INCOMPATIBILITY for tools that
   148 inspect proof terms.
   149 
   150 * Local theory specifications may depend on extra type variables that
   151 are not present in the result type -- arguments TYPE('a) :: 'a itself
   152 are added internally.  For example:
   153 
   154   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   155 
   156 * Predicates of locales introduced by classes carry a mandatory
   157 "class" prefix.  INCOMPATIBILITY.
   158 
   159 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   160 
   161 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   162 'class' instead.
   163 
   164 * Command 'code_reflect' allows to incorporate generated ML code into
   165 runtime environment; replaces immature code_datatype antiquotation.
   166 INCOMPATIBILITY.
   167 
   168 * Code generator: simple concept for abstract datatypes obeying
   169 invariants.
   170 
   171 * Code generator: details of internal data cache have no impact on the
   172 user space functionality any longer.
   173 
   174 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   175 subgoals.  This is more appropriate for interpretations with 'where'.
   176 INCOMPATIBILITY.
   177 
   178 * Command 'example_proof' opens an empty proof body.  This allows to
   179 experiment with Isar, without producing any persistent result.
   180 
   181 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   182 within a local theory context, with explicit checking of the
   183 constructors involved (in contrast to the raw 'syntax' versions).
   184 
   185 * Commands 'types' and 'typedecl' now work within a local theory
   186 context -- without introducing dependencies on parameters or
   187 assumptions, which is not possible in Isabelle/Pure.
   188 
   189 * Command 'defaultsort' has been renamed to 'default_sort', it works
   190 within a local theory context.  Minor INCOMPATIBILITY.
   191 
   192 
   193 *** HOL ***
   194 
   195 * Command 'typedef' now works within a local theory context -- without
   196 introducing dependencies on parameters or assumptions, which is not
   197 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   198 contain multiple interpretations of local typedefs (with different
   199 non-emptiness proofs), even in a global theory context.
   200 
   201 * New package for quotient types.  Commands 'quotient_type' and
   202 'quotient_definition' may be used for defining types and constants by
   203 quotient constructions.  An example is the type of integers created by
   204 quotienting pairs of natural numbers:
   205 
   206   fun
   207     intrel :: "(nat * nat) => (nat * nat) => bool"
   208   where
   209     "intrel (x, y) (u, v) = (x + v = u + y)"
   210 
   211   quotient_type int = "nat * nat" / intrel
   212     by (auto simp add: equivp_def expand_fun_eq)
   213 
   214   quotient_definition
   215     "0::int" is "(0::nat, 0::nat)"
   216 
   217 The method "lifting" can be used to lift of theorems from the
   218 underlying "raw" type to the quotient type.  The example
   219 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   220 construction and provides a reasoning infrastructure for finite sets.
   221 
   222 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   223 clash with new theory Quotient in Main HOL.
   224 
   225 * Moved the SMT binding into the main HOL session, eliminating
   226 separate HOL-SMT session.
   227 
   228 * List membership infix mem operation is only an input abbreviation.
   229 INCOMPATIBILITY.
   230 
   231 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   232 for future developements; former Library/Word.thy is still present in
   233 the AFP entry RSAPPS.
   234 
   235 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   236 longer shadowed.  INCOMPATIBILITY.
   237 
   238 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   239 INCOMPATIBILITY.
   240 
   241 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   242 INCOMPATIBILITY.
   243 
   244 * Dropped normalizing_semiring etc; use the facts in semiring classes
   245 instead.  INCOMPATIBILITY.
   246 
   247 * Dropped several real-specific versions of lemmas about floor and
   248 ceiling; use the generic lemmas from theory "Archimedean_Field"
   249 instead.  INCOMPATIBILITY.
   250 
   251   floor_number_of_eq         ~> floor_number_of
   252   le_floor_eq_number_of      ~> number_of_le_floor
   253   le_floor_eq_zero           ~> zero_le_floor
   254   le_floor_eq_one            ~> one_le_floor
   255   floor_less_eq_number_of    ~> floor_less_number_of
   256   floor_less_eq_zero         ~> floor_less_zero
   257   floor_less_eq_one          ~> floor_less_one
   258   less_floor_eq_number_of    ~> number_of_less_floor
   259   less_floor_eq_zero         ~> zero_less_floor
   260   less_floor_eq_one          ~> one_less_floor
   261   floor_le_eq_number_of      ~> floor_le_number_of
   262   floor_le_eq_zero           ~> floor_le_zero
   263   floor_le_eq_one            ~> floor_le_one
   264   floor_subtract_number_of   ~> floor_diff_number_of
   265   floor_subtract_one         ~> floor_diff_one
   266   ceiling_number_of_eq       ~> ceiling_number_of
   267   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   268   ceiling_le_zero_eq         ~> ceiling_le_zero
   269   ceiling_le_eq_one          ~> ceiling_le_one
   270   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   271   less_ceiling_eq_zero       ~> zero_less_ceiling
   272   less_ceiling_eq_one        ~> one_less_ceiling
   273   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   274   ceiling_less_eq_zero       ~> ceiling_less_zero
   275   ceiling_less_eq_one        ~> ceiling_less_one
   276   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   277   le_ceiling_eq_zero         ~> zero_le_ceiling
   278   le_ceiling_eq_one          ~> one_le_ceiling
   279   ceiling_subtract_number_of ~> ceiling_diff_number_of
   280   ceiling_subtract_one       ~> ceiling_diff_one
   281 
   282 * Theory "Finite_Set": various folding_XXX locales facilitate the
   283 application of the various fold combinators on finite sets.
   284 
   285 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   286 provides abstract red-black tree type which is backed by "RBT_Impl" as
   287 implementation.  INCOMPATIBILTY.
   288 
   289 * Theory Library/Coinductive_List has been removed -- superseded by
   290 AFP/thys/Coinductive.
   291 
   292 * Theory PReal, including the type "preal" and related operations, has
   293 been removed.  INCOMPATIBILITY.
   294 
   295 * Real: new development using Cauchy Sequences.
   296 
   297 * Split off theory "Big_Operators" containing setsum, setprod,
   298 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   299 
   300 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   301 "Int" etc.  INCOMPATIBILITY.
   302 
   303 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   304 
   305 * New set of rules "ac_simps" provides combined assoc / commute
   306 rewrites for all interpretations of the appropriate generic locales.
   307 
   308 * Renamed theory "OrderedGroup" to "Groups" and split theory
   309 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   310 appropriate and more consistent names suitable for name prefixes
   311 within the HOL theories.  INCOMPATIBILITY.
   312 
   313 * Some generic constants have been put to appropriate theories:
   314   - less_eq, less: Orderings
   315   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   316   - inverse, divide: Rings
   317 INCOMPATIBILITY.
   318 
   319 * More consistent naming of type classes involving orderings (and
   320 lattices):
   321 
   322     lower_semilattice                   ~> semilattice_inf
   323     upper_semilattice                   ~> semilattice_sup
   324 
   325     dense_linear_order                  ~> dense_linorder
   326 
   327     pordered_ab_group_add               ~> ordered_ab_group_add
   328     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   329     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   330     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   331     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   332     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   333     pordered_cancel_semiring            ~> ordered_cancel_semiring
   334     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   335     pordered_comm_ring                  ~> ordered_comm_ring
   336     pordered_comm_semiring              ~> ordered_comm_semiring
   337     pordered_ring                       ~> ordered_ring
   338     pordered_ring_abs                   ~> ordered_ring_abs
   339     pordered_semiring                   ~> ordered_semiring
   340 
   341     ordered_ab_group_add                ~> linordered_ab_group_add
   342     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   343     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   344     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   345     ordered_field                       ~> linordered_field
   346     ordered_field_no_lb                 ~> linordered_field_no_lb
   347     ordered_field_no_ub                 ~> linordered_field_no_ub
   348     ordered_field_dense_linear_order    ~> dense_linordered_field
   349     ordered_idom                        ~> linordered_idom
   350     ordered_ring                        ~> linordered_ring
   351     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   352     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   353     ordered_ring_strict                 ~> linordered_ring_strict
   354     ordered_semidom                     ~> linordered_semidom
   355     ordered_semiring                    ~> linordered_semiring
   356     ordered_semiring_1                  ~> linordered_semiring_1
   357     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   358     ordered_semiring_strict             ~> linordered_semiring_strict
   359 
   360   The following slightly odd type classes have been moved to a
   361   separate theory Library/Lattice_Algebras:
   362 
   363     lordered_ab_group_add               ~> lattice_ab_group_add
   364     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   365     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   366     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   367     lordered_ring                       ~> lattice_ring
   368 
   369 INCOMPATIBILITY.
   370 
   371 * Refined field classes:
   372   - classes division_ring_inverse_zero, field_inverse_zero,
   373     linordered_field_inverse_zero include rule inverse 0 = 0 --
   374     subsumes former division_by_zero class;
   375   - numerous lemmas have been ported from field to division_ring.
   376 INCOMPATIBILITY.
   377 
   378 * Refined algebra theorem collections:
   379   - dropped theorem group group_simps, use algebra_simps instead;
   380   - dropped theorem group ring_simps, use field_simps instead;
   381   - proper theorem collection field_simps subsumes former theorem
   382     groups field_eq_simps and field_simps;
   383   - dropped lemma eq_minus_self_iff which is a duplicate for
   384     equal_neg_zero.
   385 INCOMPATIBILITY.
   386 
   387 * Theory Finite_Set and List: some lemmas have been generalized from
   388 sets to lattices:
   389 
   390   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   391   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   392   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   393   union_Union_fold_union        ~> sup_Sup_fold_sup
   394   Inter_fold_inter              ~> Inf_fold_inf
   395   Union_fold_union              ~> Sup_fold_sup
   396   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   397   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   398   INTER_fold_inter              ~> INFI_fold_inf
   399   UNION_fold_union              ~> SUPR_fold_sup
   400 
   401 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   402 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   403 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   404 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   405 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   406 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   407 
   408 * Reorganized theory Multiset: swapped notation of pointwise and
   409 multiset order:
   410 
   411   - pointwise ordering is instance of class order with standard syntax
   412     <= and <;
   413   - multiset ordering has syntax <=# and <#; partial order properties
   414     are provided by means of interpretation with prefix
   415     multiset_order;
   416   - less duplication, less historical organization of sections,
   417     conversion from associations lists to multisets, rudimentary code
   418     generation;
   419   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   420     if needed.
   421 
   422 Renamed:
   423 
   424   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   425   multi_count_ext  ~>  multiset_ext
   426   diff_union_inverse2  ~>  diff_union_cancelR
   427 
   428 INCOMPATIBILITY.
   429 
   430 * Theory Permutation: replaced local "remove" by List.remove1.
   431 
   432 * Code generation: ML and OCaml code is decorated with signatures.
   433 
   434 * Theory List: added transpose.
   435 
   436 * Library/Nat_Bijection.thy is a collection of bijective functions
   437 between nat and other types, which supersedes the older libraries
   438 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   439 
   440   Constants:
   441   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   442   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   443   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   444   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   445   Countable.pair_encode           ~> prod_encode
   446   NatIso.prod2nat                 ~> prod_encode
   447   NatIso.nat2prod                 ~> prod_decode
   448   NatIso.sum2nat                  ~> sum_encode
   449   NatIso.nat2sum                  ~> sum_decode
   450   NatIso.list2nat                 ~> list_encode
   451   NatIso.nat2list                 ~> list_decode
   452   NatIso.set2nat                  ~> set_encode
   453   NatIso.nat2set                  ~> set_decode
   454 
   455   Lemmas:
   456   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   457   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   458   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   459   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   460   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   461   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   462   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   463   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   464   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   465   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   466   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   467   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   468   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   469 
   470 * Sledgehammer:
   471   - Renamed ATP commands:
   472     atp_info     ~> sledgehammer running_atps
   473     atp_kill     ~> sledgehammer kill_atps
   474     atp_messages ~> sledgehammer messages
   475     atp_minimize ~> sledgehammer minimize
   476     print_atps   ~> sledgehammer available_atps
   477     INCOMPATIBILITY.
   478   - Added user's manual ("isabelle doc sledgehammer").
   479   - Added option syntax and "sledgehammer_params" to customize
   480     Sledgehammer's behavior.  See the manual for details.
   481   - Modified the Isar proof reconstruction code so that it produces
   482     direct proofs rather than proofs by contradiction.  (This feature
   483     is still experimental.)
   484   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   485     full-typed mode.
   486   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   487 
   488 * Nitpick:
   489   - Added and implemented "binary_ints" and "bits" options.
   490   - Added "std" option and implemented support for nonstandard models.
   491   - Added and implemented "finitize" option to improve the precision
   492     of infinite datatypes based on a monotonicity analysis.
   493   - Added support for quotient types.
   494   - Added support for "specification" and "ax_specification"
   495     constructs.
   496   - Added support for local definitions (for "function" and
   497     "termination" proofs).
   498   - Added support for term postprocessors.
   499   - Optimized "Multiset.multiset" and "FinFun.finfun".
   500   - Improved efficiency of "destroy_constrs" optimization.
   501   - Fixed soundness bugs related to "destroy_constrs" optimization and
   502     record getters.
   503   - Fixed soundness bug related to higher-order constructors.
   504   - Fixed soundness bug when "full_descrs" is enabled.
   505   - Improved precision of set constructs.
   506   - Added "atoms" option.
   507   - Added cache to speed up repeated Kodkod invocations on the same
   508     problems.
   509   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   510     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   511     "SAT4J_Light".  INCOMPATIBILITY.
   512   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   513     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   514   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   515 
   516 * Method "induct" now takes instantiations of the form t, where t is not
   517   a variable, as a shorthand for "x == t", where x is a fresh variable.
   518   If this is not intended, t has to be enclosed in parentheses.
   519   By default, the equalities generated by definitional instantiations
   520   are pre-simplified, which may cause parameters of inductive cases
   521   to disappear, or may even delete some of the inductive cases.
   522   Use "induct (no_simp)" instead of "induct" to restore the old
   523   behaviour. The (no_simp) option is also understood by the "cases"
   524   and "nominal_induct" methods, which now perform pre-simplification, too.
   525   INCOMPATIBILITY.
   526 
   527 
   528 *** HOLCF ***
   529 
   530 * Variable names in lemmas generated by the domain package have
   531 changed; the naming scheme is now consistent with the HOL datatype
   532 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   533 
   534 * The domain package no longer defines the function "foo_copy" for
   535 recursive domain "foo".  The reach lemma is now stated directly in
   536 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   537 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   538 
   539 * Most definedness lemmas generated by the domain package (previously
   540 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   541 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   542 Proofs that used definedness lemmas as intro rules may break,
   543 potential INCOMPATIBILITY.
   544 
   545 * Induction and casedist rules generated by the domain package now
   546 declare proper case_names (one called "bottom", and one named for each
   547 constructor).  INCOMPATIBILITY.
   548 
   549 * For mutually-recursive domains, separate "reach" and "take_lemma"
   550 rules are generated for each domain, INCOMPATIBILITY.
   551 
   552   foo_bar.reach       ~> foo.reach  bar.reach
   553   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   554 
   555 * Some lemmas generated by the domain package have been renamed for
   556 consistency with the datatype package, INCOMPATIBILITY.
   557 
   558   foo.ind        ~> foo.induct
   559   foo.finite_ind ~> foo.finite_induct
   560   foo.coind      ~> foo.coinduct
   561   foo.casedist   ~> foo.exhaust
   562   foo.exhaust    ~> foo.nchotomy
   563 
   564 * For consistency with other definition packages, the fixrec package
   565 now generates qualified theorem names, INCOMPATIBILITY.
   566 
   567   foo_simps  ~> foo.simps
   568   foo_unfold ~> foo.unfold
   569   foo_induct ~> foo.induct
   570 
   571 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   572 method and internal fixrec proofs now use the default simpset instead.
   573 INCOMPATIBILITY.
   574 
   575 * The "contlub" predicate has been removed.  Proof scripts should use
   576 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   577 
   578 * The "admw" predicate has been removed, INCOMPATIBILITY.
   579 
   580 * The constants cpair, cfst, and csnd have been removed in favor of
   581 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   582 
   583 
   584 *** ML ***
   585 
   586 * Antiquotations for basic formal entities:
   587 
   588     @{class NAME}         -- type class
   589     @{class_syntax NAME}  -- syntax representation of the above
   590 
   591     @{type_name NAME}     -- logical type
   592     @{type_abbrev NAME}   -- type abbreviation
   593     @{nonterminal NAME}   -- type of concrete syntactic category
   594     @{type_syntax NAME}   -- syntax representation of any of the above
   595 
   596     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   597     @{const_abbrev NAME}  -- abbreviated constant
   598     @{const_syntax NAME}  -- syntax representation of any of the above
   599 
   600 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   601 syntax constant (cf. 'syntax' command).
   602 
   603 * Antiquotation @{make_string} inlines a function to print arbitrary
   604 values similar to the ML toplevel.  The result is compiler dependent
   605 and may fall back on "?" in certain situations.
   606 
   607 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   608 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   609 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   610 not work with the asynchronous Isar document model.
   611 
   612 * Configuration options now admit dynamic default values, depending on
   613 the context or even global references.
   614 
   615 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   616 uses an efficient external library if available (for Poly/ML).
   617 
   618 * Renamed some important ML structures, while keeping the old names
   619 for some time as aliases within the structure Legacy:
   620 
   621   OuterKeyword  ~>  Keyword
   622   OuterLex      ~>  Token
   623   OuterParse    ~>  Parse
   624   OuterSyntax   ~>  Outer_Syntax
   625   PrintMode     ~>  Print_Mode
   626   SpecParse     ~>  Parse_Spec
   627   ThyInfo       ~>  Thy_Info
   628   ThyLoad       ~>  Thy_Load
   629   ThyOutput     ~>  Thy_Output
   630   TypeInfer     ~>  Type_Infer
   631 
   632 Note that "open Legacy" simplifies porting of sources, but forgetting
   633 to remove it again will complicate porting again in the future.
   634 
   635 * Most operations that refer to a global context are named
   636 accordingly, e.g. Simplifier.global_context or
   637 ProofContext.init_global.  There are some situations where a global
   638 context actually works, but under normal circumstances one needs to
   639 pass the proper local context through the code!
   640 
   641 * Discontinued old TheoryDataFun with its copy/init operation -- data
   642 needs to be pure.  Functor Theory_Data_PP retains the traditional
   643 Pretty.pp argument to merge, which is absent in the standard
   644 Theory_Data version.
   645 
   646 * Sorts.certify_sort and derived "cert" operations for types and terms
   647 no longer minimize sorts.  Thus certification at the boundary of the
   648 inference kernel becomes invariant under addition of class relations,
   649 which is an important monotonicity principle.  Sorts are now minimized
   650 in the syntax layer only, at the boundary between the end-user and the
   651 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   652 explicitly in rare situations.
   653 
   654 * Renamed old-style Drule.standard to Drule.export_without_context, to
   655 emphasize that this is in no way a standard operation.
   656 INCOMPATIBILITY.
   657 
   658 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   659 usual for resolution.  Rare INCOMPATIBILITY.
   660 
   661 * Renamed varify/unvarify operations to varify_global/unvarify_global
   662 to emphasize that these only work in a global situation (which is
   663 quite rare).
   664 
   665 * Curried take and drop in library.ML; negative length is interpreted
   666 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   667 
   668 * Proof terms: type substitutions on proof constants now use canonical
   669 order of type variables.  INCOMPATIBILITY for tools working with proof
   670 terms.
   671 
   672 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   673 may no longer carry premises.  User-level specifications are
   674 transformed accordingly by Thm.add_axiom/add_def.
   675 
   676 
   677 *** System ***
   678 
   679 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   680 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   681 proof terms are enabled unconditionally in the new HOL-Proofs image.
   682 
   683 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   684 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   685 respectively.
   686 
   687 * Old lib/scripts/polyml-platform is superseded by the
   688 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   689 variant, even on a 64 bit machine.  The following example setting
   690 prefers 64 bit if available:
   691 
   692   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   693 
   694 * The preliminary Isabelle/jEdit application demonstrates the emerging
   695 Isabelle/Scala layer for advanced prover interaction and integration.
   696 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   697 component.
   698 
   699 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   700 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   701 similar to the default assignment of the document preparation system
   702 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   703 provides some operations for direct access to the font without asking
   704 the user for manual installation.
   705 
   706 
   707 
   708 New in Isabelle2009-1 (December 2009)
   709 -------------------------------------
   710 
   711 *** General ***
   712 
   713 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   714 one backslash should be used, even in ML sources.
   715 
   716 
   717 *** Pure ***
   718 
   719 * Locale interpretation propagates mixins along the locale hierarchy.
   720 The currently only available mixins are the equations used to map
   721 local definitions to terms of the target domain of an interpretation.
   722 
   723 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   724 loc" to print all interpretations of locale "loc" in the theory.
   725 Interpretations in proofs are not shown.
   726 
   727 * Thoroughly revised locales tutorial.  New section on conditional
   728 interpretation.
   729 
   730 * On instantiation of classes, remaining undefined class parameters
   731 are formally declared.  INCOMPATIBILITY.
   732 
   733 
   734 *** Document preparation ***
   735 
   736 * New generalized style concept for printing terms: @{foo (style) ...}
   737 instead of @{foo_style style ...}  (old form is still retained for
   738 backward compatibility).  Styles can be also applied for
   739 antiquotations prop, term_type and typeof.
   740 
   741 
   742 *** HOL ***
   743 
   744 * New proof method "smt" for a combination of first-order logic with
   745 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   746 fixed-size bitvectors; there is also basic support for higher-order
   747 features (esp. lambda abstractions).  It is an incomplete decision
   748 procedure based on external SMT solvers using the oracle mechanism;
   749 for the SMT solver Z3, this method is proof-producing.  Certificates
   750 are provided to avoid calling the external solvers solely for
   751 re-checking proofs.  Due to a remote SMT service there is no need for
   752 installing SMT solvers locally.  See src/HOL/SMT.
   753 
   754 * New commands to load and prove verification conditions generated by
   755 the Boogie program verifier or derived systems (e.g. the Verifying C
   756 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   757 
   758 * New counterexample generator tool 'nitpick' based on the Kodkod
   759 relational model finder.  See src/HOL/Tools/Nitpick and
   760 src/HOL/Nitpick_Examples.
   761 
   762 * New commands 'code_pred' and 'values' to invoke the predicate
   763 compiler and to enumerate values of inductive predicates.
   764 
   765 * A tabled implementation of the reflexive transitive closure.
   766 
   767 * New implementation of quickcheck uses generic code generator;
   768 default generators are provided for all suitable HOL types, records
   769 and datatypes.  Old quickcheck can be re-activated importing theory
   770 Library/SML_Quickcheck.
   771 
   772 * New testing tool Mirabelle for automated proof tools.  Applies
   773 several tools and tactics like sledgehammer, metis, or quickcheck, to
   774 every proof step in a theory.  To be used in batch mode via the
   775 "mirabelle" utility.
   776 
   777 * New proof method "sos" (sum of squares) for nonlinear real
   778 arithmetic (originally due to John Harison). It requires theory
   779 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   780 works well in practice on quantifier-free real arithmetic with +, -,
   781 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   782 inequalities between polynomials.  It makes use of external
   783 semidefinite programming solvers.  Method "sos" generates a
   784 certificate that can be pasted into the proof thus avoiding the need
   785 to call an external tool every time the proof is checked.  See
   786 src/HOL/Library/Sum_Of_Squares.
   787 
   788 * New method "linarith" invokes existing linear arithmetic decision
   789 procedure only.
   790 
   791 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   792 
   793 * New Sledgehammer option "Full Types" in Proof General settings menu.
   794 Causes full type information to be output to the ATPs.  This slows
   795 ATPs down considerably but eliminates a source of unsound "proofs"
   796 that fail later.
   797 
   798 * New method "metisFT": A version of metis that uses full type
   799 information in order to avoid failures of proof reconstruction.
   800 
   801 * New evaluator "approximate" approximates an real valued term using
   802 the same method as the approximation method.
   803 
   804 * Method "approximate" now supports arithmetic expressions as
   805 boundaries of intervals and implements interval splitting and Taylor
   806 series expansion.
   807 
   808 * ML antiquotation @{code_datatype} inserts definition of a datatype
   809 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   810 
   811 * New theory SupInf of the supremum and infimum operators for sets of
   812 reals.
   813 
   814 * New theory Probability, which contains a development of measure
   815 theory, eventually leading to Lebesgue integration and probability.
   816 
   817 * Extended Multivariate Analysis to include derivation and Brouwer's
   818 fixpoint theorem.
   819 
   820 * Reorganization of number theory, INCOMPATIBILITY:
   821   - new number theory development for nat and int, in theories Divides
   822     and GCD as well as in new session Number_Theory
   823   - some constants and facts now suffixed with _nat and _int
   824     accordingly
   825   - former session NumberTheory now named Old_Number_Theory, including
   826     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   827   - moved theory Pocklington from src/HOL/Library to
   828     src/HOL/Old_Number_Theory
   829 
   830 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   831 lcm of finite and infinite sets. It is shown that they form a complete
   832 lattice.
   833 
   834 * Class semiring_div requires superclass no_zero_divisors and proof of
   835 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   836 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   837 generalized to class semiring_div, subsuming former theorems
   838 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   839 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   840 INCOMPATIBILITY.
   841 
   842 * Refinements to lattice classes and sets:
   843   - less default intro/elim rules in locale variant, more default
   844     intro/elim rules in class variant: more uniformity
   845   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   846     le_inf_iff
   847   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   848     sup_aci)
   849   - renamed ACI to inf_sup_aci
   850   - new class "boolean_algebra"
   851   - class "complete_lattice" moved to separate theory
   852     "Complete_Lattice"; corresponding constants (and abbreviations)
   853     renamed and with authentic syntax:
   854     Set.Inf ~>    Complete_Lattice.Inf
   855     Set.Sup ~>    Complete_Lattice.Sup
   856     Set.INFI ~>   Complete_Lattice.INFI
   857     Set.SUPR ~>   Complete_Lattice.SUPR
   858     Set.Inter ~>  Complete_Lattice.Inter
   859     Set.Union ~>  Complete_Lattice.Union
   860     Set.INTER ~>  Complete_Lattice.INTER
   861     Set.UNION ~>  Complete_Lattice.UNION
   862   - authentic syntax for
   863     Set.Pow
   864     Set.image
   865   - mere abbreviations:
   866     Set.empty               (for bot)
   867     Set.UNIV                (for top)
   868     Set.inter               (for inf, formerly Set.Int)
   869     Set.union               (for sup, formerly Set.Un)
   870     Complete_Lattice.Inter  (for Inf)
   871     Complete_Lattice.Union  (for Sup)
   872     Complete_Lattice.INTER  (for INFI)
   873     Complete_Lattice.UNION  (for SUPR)
   874   - object-logic definitions as far as appropriate
   875 
   876 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   877 Un_subset_iff are explicitly deleted as default simp rules; then also
   878 their lattice counterparts le_inf_iff and le_sup_iff have to be
   879 deleted to achieve the desired effect.
   880 
   881 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   882 rules by default any longer; the same applies to min_max.inf_absorb1
   883 etc.  INCOMPATIBILITY.
   884 
   885 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   886 pred_set_conv by default.  INCOMPATIBILITY.
   887 
   888 * Power operations on relations and functions are now one dedicated
   889 constant "compow" with infix syntax "^^".  Power operation on
   890 multiplicative monoids retains syntax "^" and is now defined generic
   891 in class power.  INCOMPATIBILITY.
   892 
   893 * Relation composition "R O S" now has a more standard argument order:
   894 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   895 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   896 break, since the O_assoc rule was not rewritten like this.  Fix using
   897 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   898 
   899 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   900 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   901 INCOMPATIBILITY.
   902 
   903 * Most rules produced by inductive and datatype package have mandatory
   904 prefixes.  INCOMPATIBILITY.
   905 
   906 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   907 the attribute of the same name.  Each of the theorems in the list
   908 DERIV_intros assumes composition with an additional function and
   909 matches a variable to the derivative, which has to be solved by the
   910 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   911 of most elementary terms.  Former Maclauren.DERIV_tac and
   912 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   913 INCOMPATIBILITY.
   914 
   915 * Code generator attributes follow the usual underscore convention:
   916     code_unfold     replaces    code unfold
   917     code_post       replaces    code post
   918     etc.
   919   INCOMPATIBILITY.
   920 
   921 * Renamed methods:
   922     sizechange -> size_change
   923     induct_scheme -> induction_schema
   924   INCOMPATIBILITY.
   925 
   926 * Discontinued abbreviation "arbitrary" of constant "undefined".
   927 INCOMPATIBILITY, use "undefined" directly.
   928 
   929 * Renamed theorems:
   930     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   931     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   932     Suc_plus1 -> Suc_eq_plus1
   933     *anti_sym -> *antisym*
   934     vector_less_eq_def -> vector_le_def
   935   INCOMPATIBILITY.
   936 
   937 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   938 INCOMPATIBILITY.
   939 
   940 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   941 INCOMPATIBILITY.
   942 
   943 
   944 *** HOLCF ***
   945 
   946 * Theory Representable defines a class "rep" of domains that are
   947 representable (via an ep-pair) in the universal domain type "udom".
   948 Instances are provided for all type constructors defined in HOLCF.
   949 
   950 * The 'new_domain' command is a purely definitional version of the
   951 domain package, for representable domains.  Syntax is identical to the
   952 old domain package.  The 'new_domain' package also supports indirect
   953 recursion using previously-defined type constructors.  See
   954 src/HOLCF/ex/New_Domain.thy for examples.
   955 
   956 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   957 on the left-hand side of an equation, and then performs
   958 simplification.  Rewriting is done using rules declared with the
   959 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   960 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   961 
   962 * The pattern-match compiler in 'fixrec' can now handle constructors
   963 with HOL function types.  Pattern-match combinators for the Pair
   964 constructor are pre-configured.
   965 
   966 * The 'fixrec' package now produces better fixed-point induction rules
   967 for mutually-recursive definitions:  Induction rules have conclusions
   968 of the form "P foo bar" instead of "P <foo, bar>".
   969 
   970 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   971 been renamed to "below".  The name "below" now replaces "less" in many
   972 theorem names.  (Legacy theorem names using "less" are still supported
   973 as well.)
   974 
   975 * The 'fixrec' package now supports "bottom patterns".  Bottom
   976 patterns can be used to generate strictness rules, or to make
   977 functions more strict (much like the bang-patterns supported by the
   978 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   979 examples.
   980 
   981 
   982 *** ML ***
   983 
   984 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   985 errors and run-time exceptions, including detailed source positions.
   986 
   987 * Structure Name_Space (formerly NameSpace) now manages uniquely
   988 identified entries, with some additional information such as source
   989 position, logical grouping etc.
   990 
   991 * Theory and context data is now introduced by the simplified and
   992 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   993 to be pure, but the old TheoryDataFun for mutable data (with explicit
   994 copy operation) is still available for some time.
   995 
   996 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   997 provides a high-level programming interface to synchronized state
   998 variables with atomic update.  This works via pure function
   999 application within a critical section -- its runtime should be as
  1000 short as possible; beware of deadlocks if critical code is nested,
  1001 either directly or indirectly via other synchronized variables!
  1002 
  1003 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1004 wraps raw ML references, explicitly indicating their non-thread-safe
  1005 behaviour.  The Isar toplevel keeps this structure open, to
  1006 accommodate Proof General as well as quick and dirty interactive
  1007 experiments with references.
  1008 
  1009 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1010 parallel tactical reasoning.
  1011 
  1012 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1013 are similar to SUBPROOF, but are slightly more flexible: only the
  1014 specified parts of the subgoal are imported into the context, and the
  1015 body tactic may introduce new subgoals and schematic variables.
  1016 
  1017 * Old tactical METAHYPS, which does not observe the proof context, has
  1018 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1019 or Subgoal.FOCUS etc.
  1020 
  1021 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1022 functors have their own ML name space there is no point to mark them
  1023 separately.)  Minor INCOMPATIBILITY.
  1024 
  1025 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1026 
  1027 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1028 INCOMPATIBILITY.
  1029 
  1030 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1031 mode, which avoids critical setmp.
  1032 
  1033 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1034 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1035 Attrib/Method.setup introduced in Isabelle2009.
  1036 
  1037 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1038 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1039 last resort.  INCOMPATIBILITY.
  1040 
  1041 * Display.pretty_thm now requires a proper context (cf. former
  1042 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1043 or even Display.pretty_thm_without_context as last resort.
  1044 INCOMPATIBILITY.
  1045 
  1046 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1047 Syntax.pretty_typ/term directly, preferably with proper context
  1048 instead of global theory.
  1049 
  1050 
  1051 *** System ***
  1052 
  1053 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1054 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1055 usedir option -q.
  1056 
  1057 * Support for additional "Isabelle components" via etc/components, see
  1058 also the system manual.
  1059 
  1060 * The isabelle makeall tool now operates on all components with
  1061 IsaMakefile, not just hardwired "logics".
  1062 
  1063 * Removed "compress" option from isabelle-process and isabelle usedir;
  1064 this is always enabled.
  1065 
  1066 * Discontinued support for Poly/ML 4.x versions.
  1067 
  1068 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1069 on a given logic image.  This requires the lighttpd webserver and is
  1070 currently supported on Linux only.
  1071 
  1072 
  1073 
  1074 New in Isabelle2009 (April 2009)
  1075 --------------------------------
  1076 
  1077 *** General ***
  1078 
  1079 * Simplified main Isabelle executables, with less surprises on
  1080 case-insensitive file-systems (such as Mac OS).
  1081 
  1082   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1083     "isatool."
  1084 
  1085   - The former "isabelle" alias for "isabelle-process" has been
  1086     removed (should rarely occur to regular users).
  1087 
  1088   - The former "isabelle-interface" and its alias "Isabelle" have been
  1089     removed (interfaces are now regular Isabelle tools).
  1090 
  1091 Within scripts and make files, the Isabelle environment variables
  1092 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1093 respectively.  (The latter are still available as legacy feature.)
  1094 
  1095 The old isabelle-interface wrapper could react in confusing ways if
  1096 the interface was uninstalled or changed otherwise.  Individual
  1097 interface tool configuration is now more explicit, see also the
  1098 Isabelle system manual.  In particular, Proof General is now available
  1099 via "isabelle emacs".
  1100 
  1101 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1102 purge installed copies of Isabelle executables and re-run "isabelle
  1103 install -p ...", or use symlinks.
  1104 
  1105 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1106 old ~/isabelle, which was slightly non-standard and apt to cause
  1107 surprises on case-insensitive file-systems (such as Mac OS).
  1108 
  1109 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1110 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1111 care is required when using older releases of Isabelle.  Note that
  1112 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1113 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1114 
  1115 * Proofs of fully specified statements are run in parallel on
  1116 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1117 a regular 4-core machine, if the initial heap space is made reasonably
  1118 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1119 
  1120 * The main reference manuals ("isar-ref", "implementation", and
  1121 "system") have been updated and extended.  Formally checked references
  1122 as hyperlinks are now available uniformly.
  1123 
  1124 
  1125 *** Pure ***
  1126 
  1127 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1128 respects.  The most important changes are listed below.  See the
  1129 Tutorial on Locales ("locales" manual) for details.
  1130 
  1131 - In locale expressions, instantiation replaces renaming.  Parameters
  1132 must be declared in a for clause.  To aid compatibility with previous
  1133 parameter inheritance, in locale declarations, parameters that are not
  1134 'touched' (instantiation position "_" or omitted) are implicitly added
  1135 with their syntax at the beginning of the for clause.
  1136 
  1137 - Syntax from abbreviations and definitions in locales is available in
  1138 locale expressions and context elements.  The latter is particularly
  1139 useful in locale declarations.
  1140 
  1141 - More flexible mechanisms to qualify names generated by locale
  1142 expressions.  Qualifiers (prefixes) may be specified in locale
  1143 expressions, and can be marked as mandatory (syntax: "name!:") or
  1144 optional (syntax "name?:").  The default depends for plain "name:"
  1145 depends on the situation where a locale expression is used: in
  1146 commands 'locale' and 'sublocale' prefixes are optional, in
  1147 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1148 implicit qualifiers derived from the parameter names of a locale are
  1149 no longer generated.
  1150 
  1151 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1152 instantiation clause in "interpretation" and "interpret" (square
  1153 brackets) is no longer available.  Use locale expressions.
  1154 
  1155 - When converting proof scripts, mandatory qualifiers in
  1156 'interpretation' and 'interpret' should be retained by default, even
  1157 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1158 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1159 in locale expressions range over a single locale instance only.
  1160 
  1161 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1162 In existing theorem specifications replace the includes element by the
  1163 respective context elements of the included locale, omitting those
  1164 that are already present in the theorem specification.  Multiple
  1165 assume elements of a locale should be replaced by a single one
  1166 involving the locale predicate.  In the proof body, declarations (most
  1167 notably theorems) may be regained by interpreting the respective
  1168 locales in the proof context as required (command "interpret").
  1169 
  1170 If using "includes" in replacement of a target solely because the
  1171 parameter types in the theorem are not as general as in the target,
  1172 consider declaring a new locale with additional type constraints on
  1173 the parameters (context element "constrains").
  1174 
  1175 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1176 
  1177 - Locale interpretation commands no longer attempt to simplify goal.
  1178 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1179 methods intro_locales and unfold_locales to clarify.
  1180 
  1181 - Locale interpretation commands no longer accept interpretation
  1182 attributes.  INCOMPATIBILITY.
  1183 
  1184 * Class declaration: so-called "base sort" must not be given in import
  1185 list any longer, but is inferred from the specification.  Particularly
  1186 in HOL, write
  1187 
  1188     class foo = ...
  1189 
  1190 instead of
  1191 
  1192     class foo = type + ...
  1193 
  1194 * Class target: global versions of theorems stemming do not carry a
  1195 parameter prefix any longer.  INCOMPATIBILITY.
  1196 
  1197 * Class 'instance' command no longer accepts attached definitions.
  1198 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1199 
  1200 * Recovered hiding of consts, which was accidentally broken in
  1201 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1202 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1203 
  1204 * Slightly more coherent Pure syntax, with updated documentation in
  1205 isar-ref manual.  Removed locales meta_term_syntax and
  1206 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1207 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1208 directly in regular applications.
  1209 
  1210 * There is a new syntactic category "float_const" for signed decimal
  1211 fractions (e.g. 123.45 or -123.45).
  1212 
  1213 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1214 interface with 'setup' command instead.
  1215 
  1216 * Command 'local_setup' is similar to 'setup', but operates on a local
  1217 theory context.
  1218 
  1219 * The 'axiomatization' command now only works within a global theory
  1220 context.  INCOMPATIBILITY.
  1221 
  1222 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1223 hypotheses.  Sorts required in the course of reasoning need to be
  1224 covered by the constraints in the initial statement, completed by the
  1225 type instance information of the background theory.  Non-trivial sort
  1226 hypotheses, which rarely occur in practice, may be specified via
  1227 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1228 
  1229   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1230 
  1231 The result contains an implicit sort hypotheses as before --
  1232 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1233 normalization.
  1234 
  1235 * Generalized Isar history, with support for linear undo, direct state
  1236 addressing etc.
  1237 
  1238 * Changed defaults for unify configuration options:
  1239 
  1240   unify_trace_bound = 50 (formerly 25)
  1241   unify_search_bound = 60 (formerly 30)
  1242 
  1243 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1244 
  1245   a) On theory merge, the last set of code equations for a particular
  1246      constant is taken (in accordance with the policy applied by other
  1247      parts of the code generator framework).
  1248 
  1249   b) Code equations stemming from explicit declarations (e.g. code
  1250      attribute) gain priority over default code equations stemming
  1251      from definition, primrec, fun etc.
  1252 
  1253 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1254 
  1255 * Unified theorem tables for both code generators.  Thus [code
  1256 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1257 
  1258 * Command 'find_consts' searches for constants based on type and name
  1259 patterns, e.g.
  1260 
  1261     find_consts "_ => bool"
  1262 
  1263 By default, matching is against subtypes, but it may be restricted to
  1264 the whole type.  Searching by name is possible.  Multiple queries are
  1265 conjunctive and queries may be negated by prefixing them with a
  1266 hyphen:
  1267 
  1268     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1269 
  1270 * New 'find_theorems' criterion "solves" matches theorems that
  1271 directly solve the current goal (modulo higher-order unification).
  1272 
  1273 * Auto solve feature for main theorem statements: whenever a new goal
  1274 is stated, "find_theorems solves" is called; any theorems that could
  1275 solve the lemma directly are listed as part of the goal state.
  1276 Cf. associated options in Proof General Isabelle settings menu,
  1277 enabled by default, with reasonable timeout for pathological cases of
  1278 higher-order unification.
  1279 
  1280 
  1281 *** Document preparation ***
  1282 
  1283 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1284 demanding keyword 'by' and supporting the full method expression
  1285 syntax just like the Isar command 'by'.
  1286 
  1287 
  1288 *** HOL ***
  1289 
  1290 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1291 points Main and Complex_Main remain as before.
  1292 
  1293 * Logic image HOL-Plain provides a minimal HOL with the most important
  1294 tools available (inductive, datatype, primrec, ...).  This facilitates
  1295 experimentation and tool development.  Note that user applications
  1296 (and library theories) should never refer to anything below theory
  1297 Main, as before.
  1298 
  1299 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1300 experimentation due to shorter build times.
  1301 
  1302 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1303 were previously part of former HOL-Complex.  Entry point Hyperreal
  1304 remains valid, but theories formerly using Complex_Main should now use
  1305 new entry point Hypercomplex.
  1306 
  1307 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1308 Posix processes.  Avoids potentially expensive forking of the ML
  1309 process.  New thread-based implementation also works on non-Unix
  1310 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1311 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1312 commands are covered in the isar-ref manual.
  1313 
  1314 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1315 sledgehammer without local ATP installation (Vampire etc.). Other
  1316 provers may be included via suitable ML wrappers, see also
  1317 src/HOL/ATP_Linkup.thy.
  1318 
  1319 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1320 menu.
  1321 
  1322 * The metis method no longer fails because the theorem is too trivial
  1323 (contains the empty clause).
  1324 
  1325 * The metis method now fails in the usual manner, rather than raising
  1326 an exception, if it determines that it cannot prove the theorem.
  1327 
  1328 * Method "coherent" implements a prover for coherent logic (see also
  1329 src/Tools/coherent.ML).
  1330 
  1331 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1332 "undefined" is the right choice to replace "arbitrary", though
  1333 logically there is no difference.  INCOMPATIBILITY.
  1334 
  1335 * Command "value" now integrates different evaluation mechanisms.  The
  1336 result of the first successful evaluation mechanism is printed.  In
  1337 square brackets a particular named evaluation mechanisms may be
  1338 specified (currently, [SML], [code] or [nbe]).  See further
  1339 src/HOL/ex/Eval_Examples.thy.
  1340 
  1341 * Normalization by evaluation now allows non-leftlinear equations.
  1342 Declare with attribute [code nbe].
  1343 
  1344 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1345 as the structured Isar versions "cases" and "induct", cf. the
  1346 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1347 are now presented as a list of individual projections
  1348 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1349 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1350 rare situations a different rule is selected --- notably nested tuple
  1351 elimination instead of former prod.exhaust: use explicit (case_tac t
  1352 rule: prod.exhaust) here.
  1353 
  1354 * Attributes "cases", "induct", "coinduct" support "del" option.
  1355 
  1356 * Removed fact "case_split_thm", which duplicates "case_split".
  1357 
  1358 * The option datatype has been moved to a new theory Option.  Renamed
  1359 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1360 
  1361 * New predicate "strict_mono" classifies strict functions on partial
  1362 orders.  With strict functions on linear orders, reasoning about
  1363 (in)equalities is facilitated by theorems "strict_mono_eq",
  1364 "strict_mono_less_eq" and "strict_mono_less".
  1365 
  1366 * Some set operations are now proper qualified constants with
  1367 authentic syntax.  INCOMPATIBILITY:
  1368 
  1369     op Int ~>   Set.Int
  1370     op Un ~>    Set.Un
  1371     INTER ~>    Set.INTER
  1372     UNION ~>    Set.UNION
  1373     Inter ~>    Set.Inter
  1374     Union ~>    Set.Union
  1375     {} ~>       Set.empty
  1376     UNIV ~>     Set.UNIV
  1377 
  1378 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1379 theory Set.
  1380 
  1381 * Auxiliary class "itself" has disappeared -- classes without any
  1382 parameter are treated as expected by the 'class' command.
  1383 
  1384 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1385 
  1386 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1387 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1388 
  1389 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1390 method "approximation".  It proves formulas on real values by using
  1391 interval arithmetic.  In the formulas are also the transcendental
  1392 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1393 allowed. For examples see
  1394 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1395 
  1396 * Theory "Reflection" now resides in HOL/Library.
  1397 
  1398 * Entry point to Word library now simply named "Word".
  1399 INCOMPATIBILITY.
  1400 
  1401 * Made source layout more coherent with logical distribution
  1402 structure:
  1403 
  1404     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1405     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1406     src/HOL/Library/GCD.thy ~> src/HOL/
  1407     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1408     src/HOL/Library/Parity.thy ~> src/HOL/
  1409     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1410     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1411     src/HOL/Real/Lubs.thy ~> src/HOL/
  1412     src/HOL/Real/PReal.thy ~> src/HOL/
  1413     src/HOL/Real/Rational.thy ~> src/HOL/
  1414     src/HOL/Real/RComplete.thy ~> src/HOL/
  1415     src/HOL/Real/RealDef.thy ~> src/HOL/
  1416     src/HOL/Real/RealPow.thy ~> src/HOL/
  1417     src/HOL/Real/Real.thy ~> src/HOL/
  1418     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1419     src/HOL/Complex/Complex.thy ~> src/HOL/
  1420     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1421     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1422     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1423     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1424     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1425     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1426     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1427     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1428     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1429     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1430     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1431     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1432     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1433     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1434     src/HOL/Real/Float ~> src/HOL/Library/
  1435     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1436     src/HOL/Real/RealVector.thy ~> src/HOL/
  1437 
  1438     src/HOL/arith_data.ML ~> src/HOL/Tools
  1439     src/HOL/hologic.ML ~> src/HOL/Tools
  1440     src/HOL/simpdata.ML ~> src/HOL/Tools
  1441     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1442     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1443     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1444     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1445     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1446     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1447     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1448 
  1449     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1450     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1451     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1452     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1453     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1454     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1455 
  1456 * If methods "eval" and "evaluation" encounter a structured proof
  1457 state with !!/==>, only the conclusion is evaluated to True (if
  1458 possible), avoiding strange error messages.
  1459 
  1460 * Method "sizechange" automates termination proofs using (a
  1461 modification of) the size-change principle.  Requires SAT solver.  See
  1462 src/HOL/ex/Termination.thy for examples.
  1463 
  1464 * Simplifier: simproc for let expressions now unfolds if bound
  1465 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1466 
  1467 * Method "arith": Linear arithmetic now ignores all inequalities when
  1468 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1469 
  1470 * New attribute "arith" for facts that should always be used
  1471 automatically by arithmetic. It is intended to be used locally in
  1472 proofs, e.g.
  1473 
  1474   assumes [arith]: "x > 0"
  1475 
  1476 Global usage is discouraged because of possible performance impact.
  1477 
  1478 * New classes "top" and "bot" with corresponding operations "top" and
  1479 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1480 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1481 
  1482 * Changed definition lemma "less_fun_def" in order to provide an
  1483 instance for preorders on functions; use lemma "less_le" instead.
  1484 INCOMPATIBILITY.
  1485 
  1486 * Theory Orderings: class "wellorder" moved here, with explicit
  1487 induction rule "less_induct" as assumption.  For instantiation of
  1488 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1489 INCOMPATIBILITY.
  1490 
  1491 * Theory Orderings: added class "preorder" as superclass of "order".
  1492 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1493 etc. slightly changed.  Some theorems named order_class.* now named
  1494 preorder_class.*.
  1495 
  1496 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1497 "diag" to "Id_on".
  1498 
  1499 * Theory Finite_Set: added a new fold combinator of type
  1500 
  1501   ('a => 'b => 'b) => 'b => 'a set => 'b
  1502 
  1503 Occasionally this is more convenient than the old fold combinator
  1504 which is now defined in terms of the new one and renamed to
  1505 fold_image.
  1506 
  1507 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1508 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1509 extended with further lemmas!).  At the moment both still exist but
  1510 the former will disappear at some point.
  1511 
  1512 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1513 class recpower.  Type-specific simp rules for various recpower types
  1514 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1515 
  1516 rat_power_0    -> power_0
  1517 rat_power_Suc  -> power_Suc
  1518 realpow_0      -> power_0
  1519 realpow_Suc    -> power_Suc
  1520 complexpow_0   -> power_0
  1521 complexpow_Suc -> power_Suc
  1522 power_poly_0   -> power_0
  1523 power_poly_Suc -> power_Suc
  1524 
  1525 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1526 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1527 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1528 of lemmas from Divides has been generalized from nat to class
  1529 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1530 renames resulting from duplicate elimination:
  1531 
  1532     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1533     zero_dvd_iff ~>         dvd_0_left_iff
  1534     dvd_0 ~>                dvd_0_right
  1535     DIVISION_BY_ZERO_DIV ~> div_by_0
  1536     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1537     mult_div ~>             div_mult_self2_is_id
  1538     mult_mod ~>             mod_mult_self2_is_0
  1539 
  1540 * Theory IntDiv: removed many lemmas that are instances of class-based
  1541 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1542 rename old lemmas as follows:
  1543 
  1544 dvd_diff               -> nat_dvd_diff
  1545 dvd_zminus_iff         -> dvd_minus_iff
  1546 mod_add1_eq            -> mod_add_eq
  1547 mod_mult1_eq           -> mod_mult_right_eq
  1548 mod_mult1_eq'          -> mod_mult_left_eq
  1549 mod_mult_distrib_mod   -> mod_mult_eq
  1550 nat_mod_add_left_eq    -> mod_add_left_eq
  1551 nat_mod_add_right_eq   -> mod_add_right_eq
  1552 nat_mod_div_trivial    -> mod_div_trivial
  1553 nat_mod_mod_trivial    -> mod_mod_trivial
  1554 zdiv_zadd_self1        -> div_add_self1
  1555 zdiv_zadd_self2        -> div_add_self2
  1556 zdiv_zmult_self1       -> div_mult_self2_is_id
  1557 zdiv_zmult_self2       -> div_mult_self1_is_id
  1558 zdvd_triv_left         -> dvd_triv_left
  1559 zdvd_triv_right        -> dvd_triv_right
  1560 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1561 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1562 zmod_zadd_left_eq      -> mod_add_left_eq
  1563 zmod_zadd_right_eq     -> mod_add_right_eq
  1564 zmod_zadd_self1        -> mod_add_self1
  1565 zmod_zadd_self2        -> mod_add_self2
  1566 zmod_zadd1_eq          -> mod_add_eq
  1567 zmod_zdiff1_eq         -> mod_diff_eq
  1568 zmod_zdvd_zmod         -> mod_mod_cancel
  1569 zmod_zmod_cancel       -> mod_mod_cancel
  1570 zmod_zmult_self1       -> mod_mult_self2_is_0
  1571 zmod_zmult_self2       -> mod_mult_self1_is_0
  1572 zmod_1                 -> mod_by_1
  1573 zdiv_1                 -> div_by_1
  1574 zdvd_abs1              -> abs_dvd_iff
  1575 zdvd_abs2              -> dvd_abs_iff
  1576 zdvd_refl              -> dvd_refl
  1577 zdvd_trans             -> dvd_trans
  1578 zdvd_zadd              -> dvd_add
  1579 zdvd_zdiff             -> dvd_diff
  1580 zdvd_zminus_iff        -> dvd_minus_iff
  1581 zdvd_zminus2_iff       -> minus_dvd_iff
  1582 zdvd_zmultD            -> dvd_mult_right
  1583 zdvd_zmultD2           -> dvd_mult_left
  1584 zdvd_zmult_mono        -> mult_dvd_mono
  1585 zdvd_0_right           -> dvd_0_right
  1586 zdvd_0_left            -> dvd_0_left_iff
  1587 zdvd_1_left            -> one_dvd
  1588 zminus_dvd_iff         -> minus_dvd_iff
  1589 
  1590 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1591 
  1592 * The real numbers offer decimal input syntax: 12.34 is translated
  1593 into 1234/10^2. This translation is not reversed upon output.
  1594 
  1595 * Theory Library/Polynomial defines an abstract type 'a poly of
  1596 univariate polynomials with coefficients of type 'a.  In addition to
  1597 the standard ring operations, it also supports div and mod.  Code
  1598 generation is also supported, using list-style constructors.
  1599 
  1600 * Theory Library/Inner_Product defines a class of real_inner for real
  1601 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1602 => real.  Class real_inner is a subclass of real_normed_vector from
  1603 theory RealVector.
  1604 
  1605 * Theory Library/Product_Vector provides instances for the product
  1606 type 'a * 'b of several classes from RealVector and Inner_Product.
  1607 Definitions of addition, subtraction, scalar multiplication, norms,
  1608 and inner products are included.
  1609 
  1610 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1611 addition to the field operations, numerals and case syntax are also
  1612 supported.
  1613 
  1614 * Theory Library/Diagonalize provides constructive version of Cantor's
  1615 first diagonalization argument.
  1616 
  1617 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1618 zlcm (for int); carried together from various gcd/lcm developements in
  1619 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1620 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1621 may recover tupled syntax as follows:
  1622 
  1623     hide (open) const gcd
  1624     abbreviation gcd where
  1625       "gcd == (%(a, b). GCD.gcd a b)"
  1626     notation (output)
  1627       GCD.gcd ("gcd '(_, _')")
  1628 
  1629 The same works for lcm, zgcd, zlcm.
  1630 
  1631 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1632 instantiations for algebraic structures.  Removed some duplicate
  1633 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1634 
  1635 * ML antiquotation @{code} takes a constant as argument and generates
  1636 corresponding code in background and inserts name of the corresponding
  1637 resulting ML value/function/datatype constructor binding in place.
  1638 All occurrences of @{code} with a single ML block are generated
  1639 simultaneously.  Provides a generic and safe interface for
  1640 instrumentalizing code generation.  See
  1641 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1642 In future you ought to refrain from ad-hoc compiling generated SML
  1643 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1644 cannot refer to constants for which user-defined serializations are
  1645 set.  Refer to the corresponding ML counterpart directly in that
  1646 cases.
  1647 
  1648 * Command 'rep_datatype': instead of theorem names the command now
  1649 takes a list of terms denoting the constructors of the type to be
  1650 represented as datatype.  The characteristic theorems have to be
  1651 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1652 have disappeared in favour of existing ones:
  1653 
  1654     unit_induct                 ~> unit.induct
  1655     prod_induct                 ~> prod.induct
  1656     sum_induct                  ~> sum.induct
  1657     Suc_Suc_eq                  ~> nat.inject
  1658     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1659 
  1660 
  1661 *** HOL-Algebra ***
  1662 
  1663 * New locales for orders and lattices where the equivalence relation
  1664 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1665 locales use a record structure with field eq for the equivalence.
  1666 
  1667 * New theory of factorial domains.
  1668 
  1669 * Units_l_inv and Units_r_inv are now simp rules by default.
  1670 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1671 and/or r_inv will now also require deletion of these lemmas.
  1672 
  1673 * Renamed the following theorems, INCOMPATIBILITY:
  1674 
  1675 UpperD ~> Upper_memD
  1676 LowerD ~> Lower_memD
  1677 least_carrier ~> least_closed
  1678 greatest_carrier ~> greatest_closed
  1679 greatest_Lower_above ~> greatest_Lower_below
  1680 one_zero ~> carrier_one_zero
  1681 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1682 
  1683 
  1684 *** HOL-Nominal ***
  1685 
  1686 * Nominal datatypes can now contain type-variables.
  1687 
  1688 * Commands 'nominal_inductive' and 'equivariance' work with local
  1689 theory targets.
  1690 
  1691 * Nominal primrec can now works with local theory targets and its
  1692 specification syntax now conforms to the general format as seen in
  1693 'inductive' etc.
  1694 
  1695 * Method "perm_simp" honours the standard simplifier attributes
  1696 (no_asm), (no_asm_use) etc.
  1697 
  1698 * The new predicate #* is defined like freshness, except that on the
  1699 left hand side can be a set or list of atoms.
  1700 
  1701 * Experimental command 'nominal_inductive2' derives strong induction
  1702 principles for inductive definitions.  In contrast to
  1703 'nominal_inductive', which can only deal with a fixed number of
  1704 binders, it can deal with arbitrary expressions standing for sets of
  1705 atoms to be avoided.  The only inductive definition we have at the
  1706 moment that needs this generalisation is the typing rule for Lets in
  1707 the algorithm W:
  1708 
  1709  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1710  -----------------------------------------------------------------
  1711          Gamma |- Let x be t1 in t2 : T2
  1712 
  1713 In this rule one wants to avoid all the binders that are introduced by
  1714 "close Gamma T1".  We are looking for other examples where this
  1715 feature might be useful.  Please let us know.
  1716 
  1717 
  1718 *** HOLCF ***
  1719 
  1720 * Reimplemented the simplification procedure for proving continuity
  1721 subgoals.  The new simproc is extensible; users can declare additional
  1722 continuity introduction rules with the attribute [cont2cont].
  1723 
  1724 * The continuity simproc now uses a different introduction rule for
  1725 solving continuity subgoals on terms with lambda abstractions.  In
  1726 some rare cases the new simproc may fail to solve subgoals that the
  1727 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1728 Potential INCOMPATIBILITY.
  1729 
  1730 * Command 'fixrec': specification syntax now conforms to the general
  1731 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1732 examples.  INCOMPATIBILITY.
  1733 
  1734 
  1735 *** ZF ***
  1736 
  1737 * Proof of Zorn's Lemma for partial orders.
  1738 
  1739 
  1740 *** ML ***
  1741 
  1742 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1743 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1744 depends on multithreading, so timouts will not work before Poly/ML
  1745 5.2.1!
  1746 
  1747 * High-level support for concurrent ML programming, see
  1748 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1749 particularly convenient to organize independent functional
  1750 computations.  The concept of "synchronized variables" provides a
  1751 higher-order interface for components with shared state, avoiding the
  1752 delicate details of mutexes and condition variables.  (Requires
  1753 Poly/ML 5.2.1 or later.)
  1754 
  1755 * ML bindings produced via Isar commands are stored within the Isar
  1756 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1757 become thread-safe and work with undo as expected (concerning
  1758 top-level bindings, not side-effects on global references).
  1759 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1760 compiler at runtime; really global bindings need to be given outside a
  1761 theory.  (Requires Poly/ML 5.2 or later.)
  1762 
  1763 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1764 context.  Top-level ML bindings are stored within the proof context in
  1765 a purely sequential fashion, disregarding the nested proof structure.
  1766 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1767 proof.  (Requires Poly/ML 5.2 or later.)
  1768 
  1769 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1770 and Method.setup, as well as Isar commands 'attribute_setup' and
  1771 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1772 existing code accordingly, or use plain 'setup' together with old
  1773 Method.add_method.
  1774 
  1775 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1776 to 'a -> thm, while results are always tagged with an authentic oracle
  1777 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1778 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1779 accordingly.  Note that extra performance may be gained by producing
  1780 the cterm carefully, avoiding slow Thm.cterm_of.
  1781 
  1782 * Simplified interface for defining document antiquotations via
  1783 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1784 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1785 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1786 examples.
  1787 
  1788 * More systematic treatment of long names, abstract name bindings, and
  1789 name space operations.  Basic operations on qualified names have been
  1790 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1791 Long_Name.append.  Old type bstring has been mostly replaced by
  1792 abstract type binding (see structure Binding), which supports precise
  1793 qualification by packages and local theory targets, as well as proper
  1794 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1795 bstring values into Binding.name, or better pass through abstract
  1796 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1797 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1798 
  1799 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1800 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1801 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1802 
  1803 * Disposed old type and term read functions (Sign.read_def_typ,
  1804 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1805 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1806 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1807 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1808 resort for legacy applications.
  1809 
  1810 * Disposed old declarations, tactics, tactic combinators that refer to
  1811 the simpset or claset of an implicit theory (such as Addsimps,
  1812 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1813 embedded ML text, or local_simpset_of with a proper context passed as
  1814 explicit runtime argument.
  1815 
  1816 * Rules and tactics that read instantiations (read_instantiate,
  1817 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1818 context, which is required for parsing and type-checking.  Moreover,
  1819 the variables are specified as plain indexnames, not string encodings
  1820 thereof.  INCOMPATIBILITY.
  1821 
  1822 * Generic Toplevel.add_hook interface allows to analyze the result of
  1823 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1824 for theorem dependency output of transactions resulting in a new
  1825 theory state.
  1826 
  1827 * ML antiquotations: block-structured compilation context indicated by
  1828 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1829 
  1830   @{binding name}                         - basic name binding
  1831   @{let ?pat = term}                      - term abbreviation (HO matching)
  1832   @{note name = fact}                     - fact abbreviation
  1833   @{thm fact}                             - singleton fact (with attributes)
  1834   @{thms fact}                            - general fact (with attributes)
  1835   @{lemma prop by method}                 - singleton goal
  1836   @{lemma prop by meth1 meth2}            - singleton goal
  1837   @{lemma prop1 ... propN by method}      - general goal
  1838   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1839   @{lemma (open) ...}                     - open derivation
  1840 
  1841 
  1842 *** System ***
  1843 
  1844 * The Isabelle "emacs" tool provides a specific interface to invoke
  1845 Proof General / Emacs, with more explicit failure if that is not
  1846 installed (the old isabelle-interface script silently falls back on
  1847 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1848 installation location of the Proof General distribution.
  1849 
  1850 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1851 the Isabelle process into a JVM/Scala application.  See
  1852 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1853 process wrapper has been discontinued.)
  1854 
  1855 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1856 
  1857 * Various status messages (with exact source position information) are
  1858 emitted, if proper markup print mode is enabled.  This allows
  1859 user-interface components to provide detailed feedback on internal
  1860 prover operations.
  1861 
  1862 
  1863 
  1864 New in Isabelle2008 (June 2008)
  1865 -------------------------------
  1866 
  1867 *** General ***
  1868 
  1869 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1870 and updated, with formally checked references as hyperlinks.
  1871 
  1872 * Theory loader: use_thy (and similar operations) no longer set the
  1873 implicit ML context, which was occasionally hard to predict and in
  1874 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1875 provides a proper context already.
  1876 
  1877 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1878 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1879 'use' within a theory file will do the job.
  1880 
  1881 * Name space merge now observes canonical order, i.e. the second space
  1882 is inserted into the first one, while existing entries in the first
  1883 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1884 swap theory imports.
  1885 
  1886 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1887 INCOMPATIBILITY in identifier syntax etc.
  1888 
  1889 * Outer syntax: string tokens no longer admit escaped white space,
  1890 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1891 white space without escapes.
  1892 
  1893 * Outer syntax: string tokens may contain arbitrary character codes
  1894 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1895 "foo_bar".
  1896 
  1897 
  1898 *** Pure ***
  1899 
  1900 * Context-dependent token translations.  Default setup reverts locally
  1901 fixed variables, and adds hilite markup for undeclared frees.
  1902 
  1903 * Unused theorems can be found using the new command 'unused_thms'.
  1904 There are three ways of invoking it:
  1905 
  1906 (1) unused_thms
  1907      Only finds unused theorems in the current theory.
  1908 
  1909 (2) unused_thms thy_1 ... thy_n -
  1910      Finds unused theorems in the current theory and all of its ancestors,
  1911      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1912 
  1913 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1914      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1915      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1916      their ancestors.
  1917 
  1918 In order to increase the readability of the list produced by
  1919 unused_thms, theorems that have been created by a particular instance
  1920 of a theory command such as 'inductive' or 'function' are considered
  1921 to belong to the same "group", meaning that if at least one theorem in
  1922 this group is used, the other theorems in the same group are no longer
  1923 reported as unused.  Moreover, if all theorems in the group are
  1924 unused, only one theorem in the group is displayed.
  1925 
  1926 Note that proof objects have to be switched on in order for
  1927 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1928 usually the case when using Proof General with the default settings).
  1929 
  1930 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1931 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1932 duplicate fact bindings, or even accidental fact duplications.  Note
  1933 that tools may maintain dynamically scoped facts systematically, using
  1934 PureThy.add_thms_dynamic.
  1935 
  1936 * Command 'hide' now allows to hide from "fact" name space as well.
  1937 
  1938 * Eliminated destructive theorem database, simpset, claset, and
  1939 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1940 update of theories within ML code.
  1941 
  1942 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1943 INCOMPATIBILITY, object-logics depending on former Pure require
  1944 additional setup PureThy.old_appl_syntax_setup; object-logics
  1945 depending on former CPure need to refer to Pure.
  1946 
  1947 * Commands 'use' and 'ML' are now purely functional, operating on
  1948 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1949 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1950 INCOMPATIBILITY.
  1951 
  1952 * Command 'setup': discontinued implicit version with ML reference.
  1953 
  1954 * Instantiation target allows for simultaneous specification of class
  1955 instance operations together with an instantiation proof.
  1956 Type-checking phase allows to refer to class operations uniformly.
  1957 See src/HOL/Complex/Complex.thy for an Isar example and
  1958 src/HOL/Library/Eval.thy for an ML example.
  1959 
  1960 * Indexing of literal facts: be more serious about including only
  1961 facts from the visible specification/proof context, but not the
  1962 background context (locale etc.).  Affects `prop` notation and method
  1963 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1964 situations.
  1965 
  1966 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1967 "(open)" option, which used to expose internal bound variables to the
  1968 proof text.
  1969 
  1970 * Isar statements: removed obsolete case "rule_context".
  1971 INCOMPATIBILITY, better use explicit fixes/assumes.
  1972 
  1973 * Locale proofs: default proof step now includes 'unfold_locales';
  1974 hence 'proof' without argument may be used to unfold locale
  1975 predicates.
  1976 
  1977 
  1978 *** Document preparation ***
  1979 
  1980 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1981 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1982 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1983 spot); renamed link color from "darkblue" to "linkcolor" (default
  1984 value unchanged, can be redefined via \definecolor); no longer sets
  1985 "a4paper" option (unnecessary or even intrusive).
  1986 
  1987 * Antiquotation @{lemma A method} proves proposition A by the given
  1988 method (either a method name or a method name plus (optional) method
  1989 arguments in parentheses) and prints A just like @{prop A}.
  1990 
  1991 
  1992 *** HOL ***
  1993 
  1994 * New primrec package.  Specification syntax conforms in style to
  1995 definition/function/....  No separate induction rule is provided.  The
  1996 "primrec" command distinguishes old-style and new-style specifications
  1997 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1998 When adjusting theories, beware: constants stemming from new-style
  1999 primrec specifications have authentic syntax.
  2000 
  2001 * Metis prover is now an order of magnitude faster, and also works
  2002 with multithreading.
  2003 
  2004 * Metis: the maximum number of clauses that can be produced from a
  2005 theorem is now given by the attribute max_clauses.  Theorems that
  2006 exceed this number are ignored, with a warning printed.
  2007 
  2008 * Sledgehammer no longer produces structured proofs by default. To
  2009 enable, declare [[sledgehammer_full = true]].  Attributes
  2010 reconstruction_modulus, reconstruction_sorts renamed
  2011 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2012 
  2013 * Method "induct_scheme" derives user-specified induction rules
  2014 from well-founded induction and completeness of patterns. This factors
  2015 out some operations that are done internally by the function package
  2016 and makes them available separately.  See
  2017 src/HOL/ex/Induction_Scheme.thy for examples.
  2018 
  2019 * More flexible generation of measure functions for termination
  2020 proofs: Measure functions can be declared by proving a rule of the
  2021 form "is_measure f" and giving it the [measure_function] attribute.
  2022 The "is_measure" predicate is logically meaningless (always true), and
  2023 just guides the heuristic.  To find suitable measure functions, the
  2024 termination prover sets up the goal "is_measure ?f" of the appropriate
  2025 type and generates all solutions by prolog-style backwards proof using
  2026 the declared rules.
  2027 
  2028 This setup also deals with rules like 
  2029 
  2030   "is_measure f ==> is_measure (list_size f)"
  2031 
  2032 which accommodates nested datatypes that recurse through lists.
  2033 Similar rules are predeclared for products and option types.
  2034 
  2035 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2036 
  2037   INCOMPATIBILITIES:
  2038 
  2039   - Definitions of overloaded constants on sets have to be replaced by
  2040     definitions on => and bool.
  2041 
  2042   - Some definitions of overloaded operators on sets can now be proved
  2043     using the definitions of the operators on => and bool.  Therefore,
  2044     the following theorems have been renamed:
  2045 
  2046       subset_def   -> subset_eq
  2047       psubset_def  -> psubset_eq
  2048       set_diff_def -> set_diff_eq
  2049       Compl_def    -> Compl_eq
  2050       Sup_set_def  -> Sup_set_eq
  2051       Inf_set_def  -> Inf_set_eq
  2052       sup_set_def  -> sup_set_eq
  2053       inf_set_def  -> inf_set_eq
  2054 
  2055   - Due to the incompleteness of the HO unification algorithm, some
  2056     rules such as subst may require manual instantiation, if some of
  2057     the unknowns in the rule is a set.
  2058 
  2059   - Higher order unification and forward proofs:
  2060     The proof pattern
  2061 
  2062       have "P (S::'a set)" <...>
  2063       then have "EX S. P S" ..
  2064 
  2065     no longer works (due to the incompleteness of the HO unification
  2066     algorithm) and must be replaced by the pattern
  2067 
  2068       have "EX S. P S"
  2069       proof
  2070         show "P S" <...>
  2071       qed
  2072 
  2073   - Calculational reasoning with subst (or similar rules):
  2074     The proof pattern
  2075 
  2076       have "P (S::'a set)" <...>
  2077       also have "S = T" <...>
  2078       finally have "P T" .
  2079 
  2080     no longer works (for similar reasons as the previous example) and
  2081     must be replaced by something like
  2082 
  2083       have "P (S::'a set)" <...>
  2084       moreover have "S = T" <...>
  2085       ultimately have "P T" by simp
  2086 
  2087   - Tactics or packages written in ML code:
  2088     Code performing pattern matching on types via
  2089 
  2090       Type ("set", [T]) => ...
  2091 
  2092     must be rewritten. Moreover, functions like strip_type or
  2093     binder_types no longer return the right value when applied to a
  2094     type of the form
  2095 
  2096       T1 => ... => Tn => U => bool
  2097 
  2098     rather than
  2099 
  2100       T1 => ... => Tn => U set
  2101 
  2102 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2103 Wellfounded_Relations to theory Wellfounded.
  2104 
  2105 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2106 
  2107 * Class finite no longer treats UNIV as class parameter.  Use class
  2108 enum from theory Library/Enum instead to achieve a similar effect.
  2109 INCOMPATIBILITY.
  2110 
  2111 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2112 and "Cons".  INCOMPATIBILITY.
  2113 
  2114 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2115 Potential INCOMPATIBILITY.
  2116 
  2117 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2118 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2119 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2120 
  2121 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2122 the same name in theory Orderings:
  2123 
  2124   less_trans
  2125   less_linear
  2126   le_imp_less_or_eq
  2127   le_less_trans
  2128   less_le_trans
  2129   less_not_sym
  2130   less_asym
  2131 
  2132 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2133 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2134 and different variable names.
  2135 
  2136 * Library/Option_ord.thy: Canonical order on option type.
  2137 
  2138 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2139 finite maps.
  2140 
  2141 * Library/Countable.thy: Type class for countable types.
  2142 
  2143 * Theory Int: The representation of numerals has changed.  The infix
  2144 operator BIT and the bit datatype with constructors B0 and B1 have
  2145 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2146 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2147 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2148 accordingly.
  2149 
  2150 * Theory Nat: definition of <= and < on natural numbers no longer
  2151 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2152 le_def and less_def have disappeared.  Consider lemmas not_less
  2153 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2154 
  2155 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2156 (whose purpose mainly is for various fold_set functionals) have been
  2157 abandoned in favor of the existing algebraic classes
  2158 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2159 lower_semilattice (resp. upper_semilattice) and linorder.
  2160 INCOMPATIBILITY.
  2161 
  2162 * Theory Transitive_Closure: induct and cases rules now declare proper
  2163 case_names ("base" and "step").  INCOMPATIBILITY.
  2164 
  2165 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2166 lattices.  The form set-specific version is available as
  2167 Inductive.lfp_ordinal_induct_set.
  2168 
  2169 * Renamed theorems "power.simps" to "power_int.simps".
  2170 INCOMPATIBILITY.
  2171 
  2172 * Class semiring_div provides basic abstract properties of semirings
  2173 with division and modulo operations.  Subsumes former class dvd_mod.
  2174 
  2175 * Merged theories IntDef, Numeral and IntArith into unified theory
  2176 Int.  INCOMPATIBILITY.
  2177 
  2178 * Theory Library/Code_Index: type "index" now represents natural
  2179 numbers rather than integers.  INCOMPATIBILITY.
  2180 
  2181 * New class "uminus" with operation "uminus" (split of from class
  2182 "minus" which now only has operation "minus", binary).
  2183 INCOMPATIBILITY.
  2184 
  2185 * Constants "card", "internal_split", "option_map" now with authentic
  2186 syntax.  INCOMPATIBILITY.
  2187 
  2188 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2189 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2190 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2191 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2192 Sup_set_def, le_def, less_def, option_map_def now with object
  2193 equality.  INCOMPATIBILITY.
  2194 
  2195 * Records. Removed K_record, and replaced it by pure lambda term
  2196 %x. c. The simplifier setup is now more robust against eta expansion.
  2197 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2198 
  2199 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2200 
  2201 * Library/ListVector: new theory of arithmetic vector operations.
  2202 
  2203 * Library/Order_Relation: new theory of various orderings as sets of
  2204 pairs.  Defines preorders, partial orders, linear orders and
  2205 well-orders on sets and on types.
  2206 
  2207 
  2208 *** ZF ***
  2209 
  2210 * Renamed some theories to allow to loading both ZF and HOL in the
  2211 same session:
  2212 
  2213   Datatype  -> Datatype_ZF
  2214   Inductive -> Inductive_ZF
  2215   Int       -> Int_ZF
  2216   IntDiv    -> IntDiv_ZF
  2217   Nat       -> Nat_ZF
  2218   List      -> List_ZF
  2219   Main      -> Main_ZF
  2220 
  2221 INCOMPATIBILITY: ZF theories that import individual theories below
  2222 Main might need to be adapted.  Regular theory Main is still
  2223 available, as trivial extension of Main_ZF.
  2224 
  2225 
  2226 *** ML ***
  2227 
  2228 * ML within Isar: antiquotation @{const name} or @{const
  2229 name(typargs)} produces statically-checked Const term.
  2230 
  2231 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2232 (of the same name).  Removed obsolete print command.
  2233 
  2234 * Removed obsolete "use_legacy_bindings" function.
  2235 
  2236 * The ``print mode'' is now a thread-local value derived from a global
  2237 template (the former print_mode reference), thus access becomes
  2238 non-critical.  The global print_mode reference is for session
  2239 management only; user-code should use print_mode_value,
  2240 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2241 
  2242 * Functions system/system_out provide a robust way to invoke external
  2243 shell commands, with propagation of interrupts (requires Poly/ML
  2244 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2245 
  2246 
  2247 *** System ***
  2248 
  2249 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2250 in accordance with Proof General 3.7, which prefers GNU emacs.
  2251 
  2252 * isatool tty runs Isabelle process with plain tty interaction;
  2253 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2254 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2255 
  2256 * isatool browser now works with Cygwin as well, using general
  2257 "javapath" function defined in Isabelle process environment.
  2258 
  2259 * YXML notation provides a simple and efficient alternative to
  2260 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2261 isatool yxml as described in the Isabelle system manual.
  2262 
  2263 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2264 provides general wrapper for managing an Isabelle process in a robust
  2265 fashion, with ``cooked'' output from stdin/stderr.
  2266 
  2267 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2268 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2269 
  2270 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2271 way of changing the user's settings is via
  2272 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2273 script.
  2274 
  2275 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2276 cores of the underlying machine, which is a good starting point for
  2277 optimal performance tuning.  The corresponding usedir option -M allows
  2278 "max" as an alias for "0".  WARNING: does not work on certain versions
  2279 of Mac OS (with Poly/ML 5.1).
  2280 
  2281 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2282 adverse effect of Isabelle flooding interactive front-ends (notably
  2283 ProofGeneral / XEmacs).
  2284 
  2285 
  2286 
  2287 New in Isabelle2007 (November 2007)
  2288 -----------------------------------
  2289 
  2290 *** General ***
  2291 
  2292 * More uniform information about legacy features, notably a
  2293 warning/error of "Legacy feature: ...", depending on the state of the
  2294 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2295 legacy features will disappear eventually.
  2296 
  2297 * Theory syntax: the header format ``theory A = B + C:'' has been
  2298 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2299 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2300 
  2301 * Theory syntax: the old non-Isar theory file format has been
  2302 discontinued altogether.  Note that ML proof scripts may still be used
  2303 with Isar theories; migration is usually quite simple with the ML
  2304 function use_legacy_bindings.  INCOMPATIBILITY.
  2305 
  2306 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2307 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2308 quotes.
  2309 
  2310 * Theory loader: be more serious about observing the static theory
  2311 header specifications (including optional directories), but not the
  2312 accidental file locations of previously successful loads.  The strict
  2313 update policy of former update_thy is now already performed by
  2314 use_thy, so the former has been removed; use_thys updates several
  2315 theories simultaneously, just as 'imports' within a theory header
  2316 specification, but without merging the results.  Potential
  2317 INCOMPATIBILITY: may need to refine theory headers and commands
  2318 ROOT.ML which depend on load order.
  2319 
  2320 * Theory loader: optional support for content-based file
  2321 identification, instead of the traditional scheme of full physical
  2322 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2323 (cf. the system manual).  The new scheme allows to work with
  2324 non-finished theories in persistent session images, such that source
  2325 files may be moved later on without requiring reloads.
  2326 
  2327 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2328 file (with the same base name as the theory) are considered a legacy
  2329 feature, which will disappear eventually. Even now, the theory loader
  2330 no longer maintains dependencies on such files.
  2331 
  2332 * Syntax: the scope for resolving ambiguities via type-inference is
  2333 now limited to individual terms, instead of whole simultaneous
  2334 specifications as before. This greatly reduces the complexity of the
  2335 syntax module and improves flexibility by separating parsing and
  2336 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2337 'fixes' etc.) are required in rare situations.
  2338 
  2339 * Syntax: constants introduced by new-style packages ('definition',
  2340 'abbreviation' etc.) are passed through the syntax module in
  2341 ``authentic mode''. This means that associated mixfix annotations
  2342 really stick to such constants, independently of potential name space
  2343 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2344 trees are represented slightly differently, may need to adapt syntax
  2345 translations accordingly. Use CONST marker in 'translations' and
  2346 @{const_syntax} antiquotation in 'parse_translation' etc.
  2347 
  2348 * Legacy goal package: reduced interface to the bare minimum required
  2349 to keep existing proof scripts running.  Most other user-level
  2350 functions are now part of the OldGoals structure, which is *not* open
  2351 by default (consider isatool expandshort before open OldGoals).
  2352 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2353 these tend to cause confusion about the actual goal (!) context being
  2354 used here, which is not necessarily the same as the_context().
  2355 
  2356 * Command 'find_theorems': supports "*" wild-card in "name:"
  2357 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2358 support a specific search form (see ProofGeneral/CHANGES).
  2359 
  2360 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2361 by default, which means that "prems" (and also "fixed variables") are
  2362 suppressed from proof state output.  Note that the ProofGeneral
  2363 settings mechanism allows to change and save options persistently, but
  2364 older versions of Isabelle will fail to start up if a negative prems
  2365 limit is imposed.
  2366 
  2367 * Local theory targets may be specified by non-nested blocks of
  2368 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2369 contain definitions, theorems etc., including any derived mechanism
  2370 that has been implemented on top of these primitives.  This concept
  2371 generalizes the existing ``theorem (in ...)'' towards more versatility
  2372 and scalability.
  2373 
  2374 * Proof General interface: proper undo of final 'end' command;
  2375 discontinued Isabelle/classic mode (ML proof scripts).
  2376 
  2377 
  2378 *** Document preparation ***
  2379 
  2380 * Added antiquotation @{theory name} which prints the given name,
  2381 after checking that it refers to a valid ancestor theory in the
  2382 current context.
  2383 
  2384 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2385 check the given source text as ML type/structure, printing verbatim.
  2386 
  2387 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2388 "c args == rhs" given in the current context.  (Any number of
  2389 arguments may be given on the LHS.)
  2390 
  2391 
  2392 *** Pure ***
  2393 
  2394 * The 'class' package offers a combination of axclass and locale to
  2395 achieve Haskell-like type classes in Isabelle.  Definitions and
  2396 theorems within a class context produce both relative results (with
  2397 implicit parameters according to the locale context), and polymorphic
  2398 constants with qualified polymorphism (according to the class
  2399 context).  Within the body context of a 'class' target, a separate
  2400 syntax layer ("user space type system") takes care of converting
  2401 between global polymorphic consts and internal locale representation.
  2402 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2403 "isatool doc classes" provides a tutorial.
  2404 
  2405 * Generic code generator framework allows to generate executable
  2406 code for ML and Haskell (including Isabelle classes).  A short usage
  2407 sketch:
  2408 
  2409     internal compilation:
  2410         export_code <list of constants (term syntax)> in SML
  2411     writing SML code to a file:
  2412         export_code <list of constants (term syntax)> in SML <filename>
  2413     writing OCaml code to a file:
  2414         export_code <list of constants (term syntax)> in OCaml <filename>
  2415     writing Haskell code to a bunch of files:
  2416         export_code <list of constants (term syntax)> in Haskell <filename>
  2417 
  2418     evaluating closed propositions to True/False using code generation:
  2419         method ``eval''
  2420 
  2421 Reasonable default setup of framework in HOL.
  2422 
  2423 Theorem attributs for selecting and transforming function equations theorems:
  2424 
  2425     [code fun]:        select a theorem as function equation for a specific constant
  2426     [code fun del]:    deselect a theorem as function equation for a specific constant
  2427     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2428     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2429 
  2430 User-defined serializations (target in {SML, OCaml, Haskell}):
  2431 
  2432     code_const <and-list of constants (term syntax)>
  2433       {(target) <and-list of const target syntax>}+
  2434 
  2435     code_type <and-list of type constructors>
  2436       {(target) <and-list of type target syntax>}+
  2437 
  2438     code_instance <and-list of instances>
  2439       {(target)}+
  2440         where instance ::= <type constructor> :: <class>
  2441 
  2442     code_class <and_list of classes>
  2443       {(target) <and-list of class target syntax>}+
  2444         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2445 
  2446 code_instance and code_class only are effective to target Haskell.
  2447 
  2448 For example usage see src/HOL/ex/Codegenerator.thy and
  2449 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2450 generation from Isabelle/HOL theories is available via "isatool doc
  2451 codegen".
  2452 
  2453 * Code generator: consts in 'consts_code' Isar commands are now
  2454 referred to by usual term syntax (including optional type
  2455 annotations).
  2456 
  2457 * Command 'no_translations' removes translation rules from theory
  2458 syntax.
  2459 
  2460 * Overloaded definitions are now actually checked for acyclic
  2461 dependencies.  The overloading scheme is slightly more general than
  2462 that of Haskell98, although Isabelle does not demand an exact
  2463 correspondence to type class and instance declarations.
  2464 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2465 exotic versions of overloading -- at the discretion of the user!
  2466 
  2467 Polymorphic constants are represented via type arguments, i.e. the
  2468 instantiation that matches an instance against the most general
  2469 declaration given in the signature.  For example, with the declaration
  2470 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2471 as c(nat).  Overloading is essentially simultaneous structural
  2472 recursion over such type arguments.  Incomplete specification patterns
  2473 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2474 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2475 Command 'print_theory' outputs the normalized system of recursive
  2476 equations, see section "definitions".
  2477 
  2478 * Configuration options are maintained within the theory or proof
  2479 context (with name and type bool/int/string), providing a very simple
  2480 interface to a poor-man's version of general context data.  Tools may
  2481 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2482 these values using Config.get etc.  Users may change options via an
  2483 associated attribute of the same name.  This form of context
  2484 declaration works particularly well with commands 'declare' or
  2485 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2486 very easy to avoid global references, which would not observe Isar
  2487 toplevel undo/redo and fail to work with multithreading.
  2488 
  2489 Various global ML references of Pure and HOL have been turned into
  2490 configuration options:
  2491 
  2492   Unify.search_bound		unify_search_bound
  2493   Unify.trace_bound		unify_trace_bound
  2494   Unify.trace_simp		unify_trace_simp
  2495   Unify.trace_types		unify_trace_types
  2496   Simplifier.simp_depth_limit	simp_depth_limit
  2497   Blast.depth_limit		blast_depth_limit
  2498   DatatypeProp.dtK		datatype_distinctness_limit
  2499   fast_arith_neq_limit  	fast_arith_neq_limit
  2500   fast_arith_split_limit	fast_arith_split_limit
  2501 
  2502 * Named collections of theorems may be easily installed as context
  2503 data using the functor NamedThmsFun (see also
  2504 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2505 attributes; there is also a toplevel print command.  This facility is
  2506 just a common case of general context data, which is the preferred way
  2507 for anything more complex than just a list of facts in canonical
  2508 order.
  2509 
  2510 * Isar: command 'declaration' augments a local theory by generic
  2511 declaration functions written in ML.  This enables arbitrary content
  2512 being added to the context, depending on a morphism that tells the
  2513 difference of the original declaration context wrt. the application
  2514 context encountered later on.
  2515 
  2516 * Isar: proper interfaces for simplification procedures.  Command
  2517 'simproc_setup' declares named simprocs (with match patterns, and body
  2518 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2519 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2520 
  2521 * Isar: an extra pair of brackets around attribute declarations
  2522 abbreviates a theorem reference involving an internal dummy fact,
  2523 which will be ignored later --- only the effect of the attribute on
  2524 the background context will persist.  This form of in-place
  2525 declarations is particularly useful with commands like 'declare' and
  2526 'using', for example ``have A using [[simproc a]] by simp''.
  2527 
  2528 * Isar: method "assumption" (and implicit closing of subproofs) now
  2529 takes simple non-atomic goal assumptions into account: after applying
  2530 an assumption as a rule the resulting subgoals are solved by atomic
  2531 assumption steps.  This is particularly useful to finish 'obtain'
  2532 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2533 without referring to the original premise "!!x. P x ==> thesis" in the
  2534 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2535 more permissive.
  2536 
  2537 * Isar: implicit use of prems from the Isar proof context is
  2538 considered a legacy feature.  Common applications like ``have A .''
  2539 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2540 referencing facts explicitly here improves readability and
  2541 maintainability of proof texts.
  2542 
  2543 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2544 the obtained context from the course of reasoning!  For example:
  2545 
  2546   assume "EX x y. A x & B y"   -- "any previous fact"
  2547   then guess x and y by clarify
  2548 
  2549 This technique is potentially adventurous, depending on the facts and
  2550 proof tools being involved here.
  2551 
  2552 * Isar: known facts from the proof context may be specified as literal
  2553 propositions, using ASCII back-quote syntax.  This works wherever
  2554 named facts used to be allowed so far, in proof commands, proof
  2555 methods, attributes etc.  Literal facts are retrieved from the context
  2556 according to unification of type and term parameters.  For example,
  2557 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2558 theorems in the current context, then these are valid literal facts:
  2559 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2560 
  2561 There is also a proof method "fact" which does the same composition
  2562 for explicit goal states, e.g. the following proof texts coincide with
  2563 certain special cases of literal facts:
  2564 
  2565   have "A" by fact                 ==  note `A`
  2566   have "A ==> B" by fact           ==  note `A ==> B`
  2567   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2568   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2569 
  2570 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2571 outer syntax.  Thus symbolic identifiers may be used without
  2572 additional white space in declarations like this: ``assume *: A''.
  2573 
  2574 * Isar: 'print_facts' prints all local facts of the current context,
  2575 both named and unnamed ones.
  2576 
  2577 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2578 
  2579   def x == "t" and y == "u"
  2580 
  2581 * Isar: added command 'unfolding', which is structurally similar to
  2582 'using', but affects both the goal state and facts by unfolding given
  2583 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2584 'unfolded' attribute may be replaced by first-class proof text.
  2585 
  2586 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2587 and command 'unfolding' now all support object-level equalities
  2588 (potentially conditional).  The underlying notion of rewrite rule is
  2589 analogous to the 'rule_format' attribute, but *not* that of the
  2590 Simplifier (which is usually more generous).
  2591 
  2592 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2593 premises of a theorem by n. Useful in conjunction with drule.
  2594 
  2595 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2596 method expression within a sandbox consisting of the first N
  2597 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2598 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2599 simplifies all new goals that emerge from applying rule foo to the
  2600 originally first one.
  2601 
  2602 * Isar: schematic goals are no longer restricted to higher-order
  2603 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2604 expected.
  2605 
  2606 * Isar: the conclusion of a long theorem statement is now either
  2607 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2608 (essentially a disjunction of cases with local parameters and
  2609 assumptions).  The latter allows to express general elimination rules
  2610 adequately; in this notation common elimination rules look like this:
  2611 
  2612   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2613     assumes "EX x. P x"
  2614     obtains x where "P x"
  2615 
  2616   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2617     assumes "A & B"
  2618     obtains A and B
  2619 
  2620   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2621     assumes "A | B"
  2622     obtains
  2623       A
  2624     | B
  2625 
  2626 The subsequent classical rules even refer to the formal "thesis"
  2627 explicitly:
  2628 
  2629   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2630     obtains "~ thesis"
  2631 
  2632   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2633     obtains "thesis ==> something"
  2634 
  2635 The actual proof of an 'obtains' statement is analogous to that of the
  2636 Isar proof element 'obtain', only that there may be several cases.
  2637 Optional case names may be specified in parentheses; these will be
  2638 available both in the present proof and as annotations in the
  2639 resulting rule, for later use with the 'cases' method (cf. attribute
  2640 case_names).
  2641 
  2642 * Isar: the assumptions of a long theorem statement are available as
  2643 "assms" fact in the proof context.  This is more appropriate than the
  2644 (historical) "prems", which refers to all assumptions of the current
  2645 context, including those from the target locale, proof body etc.
  2646 
  2647 * Isar: 'print_statement' prints theorems from the current theory or
  2648 proof context in long statement form, according to the syntax of a
  2649 top-level lemma.
  2650 
  2651 * Isar: 'obtain' takes an optional case name for the local context
  2652 introduction rule (default "that").
  2653 
  2654 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2655 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2656 to occur.
  2657 
  2658 * Pure: syntax "CONST name" produces a fully internalized constant
  2659 according to the current context.  This is particularly useful for
  2660 syntax translations that should refer to internal constant
  2661 representations independently of name spaces.
  2662 
  2663 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2664 instead of "FOO ". This allows multiple binder declarations to coexist
  2665 in the same context.  INCOMPATIBILITY.
  2666 
  2667 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2668 primitive that also works in a locale context (both for constants and
  2669 fixed variables). Type declaration and internal syntactic representation
  2670 of given constants retrieved from the context. Likewise, the
  2671 'no_notation' command allows to remove given syntax annotations from the
  2672 current context.
  2673 
  2674 * Isar/locales: new derived specification elements 'axiomatization',
  2675 'definition', 'abbreviation', which support type-inference, admit
  2676 object-level specifications (equality, equivalence).  See also the
  2677 isar-ref manual.  Examples:
  2678 
  2679   axiomatization
  2680     eq  (infix "===" 50) where
  2681     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2682 
  2683   definition "f x y = x + y + 1"
  2684   definition g where "g x = f x x"
  2685 
  2686   abbreviation
  2687     neq  (infix "=!=" 50) where
  2688     "x =!= y == ~ (x === y)"
  2689 
  2690 These specifications may be also used in a locale context.  Then the
  2691 constants being introduced depend on certain fixed parameters, and the
  2692 constant name is qualified by the locale base name.  An internal
  2693 abbreviation takes care for convenient input and output, making the
  2694 parameters implicit and using the original short name.  See also
  2695 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2696 entities from a monomorphic theory.
  2697 
  2698 Presently, abbreviations are only available 'in' a target locale, but
  2699 not inherited by general import expressions.  Also note that
  2700 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2701 'translations' in common applications.  The "no_abbrevs" print mode
  2702 prevents folding of abbreviations in term output.
  2703 
  2704 Concrete syntax is attached to specified constants in internal form,
  2705 independently of name spaces.  The parse tree representation is
  2706 slightly different -- use 'notation' instead of raw 'syntax', and
  2707 'translations' with explicit "CONST" markup to accommodate this.
  2708 
  2709 * Pure/Isar: unified syntax for new-style specification mechanisms
  2710 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2711 full type inference and dummy patterns ("_").  For example:
  2712 
  2713   definition "K x _ = x"
  2714 
  2715   inductive conj for A B
  2716   where "A ==> B ==> conj A B"
  2717 
  2718 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2719 the current context.  Print mode "no_abbrevs" prevents inversion of
  2720 abbreviations on output.
  2721 
  2722 * Isar/locales: improved parameter handling: use of locales "var" and
  2723 "struct" no longer necessary; - parameter renamings are no longer
  2724 required to be injective.  For example, this allows to define
  2725 endomorphisms as locale endom = homom mult mult h.
  2726 
  2727 * Isar/locales: changed the way locales with predicates are defined.
  2728 Instead of accumulating the specification, the imported expression is
  2729 now an interpretation.  INCOMPATIBILITY: different normal form of
  2730 locale expressions.  In particular, in interpretations of locales with
  2731 predicates, goals repesenting already interpreted fragments are not
  2732 removed automatically.  Use methods `intro_locales' and
  2733 `unfold_locales'; see below.
  2734 
  2735 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2736 provide backward reasoning on locales predicates.  The methods are
  2737 aware of interpretations and discharge corresponding goals.
  2738 `intro_locales' is less aggressive then `unfold_locales' and does not
  2739 unfold predicates to assumptions.
  2740 
  2741 * Isar/locales: the order in which locale fragments are accumulated
  2742 has changed.  This enables to override declarations from fragments due
  2743 to interpretations -- for example, unwanted simp rules.
  2744 
  2745 * Isar/locales: interpretation in theories and proof contexts has been
  2746 extended.  One may now specify (and prove) equations, which are
  2747 unfolded in interpreted theorems.  This is useful for replacing
  2748 defined concepts (constants depending on locale parameters) by
  2749 concepts already existing in the target context.  Example:
  2750 
  2751   interpretation partial_order ["op <= :: [int, int] => bool"]
  2752     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2753 
  2754 Typically, the constant `partial_order.less' is created by a
  2755 definition specification element in the context of locale
  2756 partial_order.
  2757 
  2758 * Method "induct": improved internal context management to support
  2759 local fixes and defines on-the-fly. Thus explicit meta-level
  2760 connectives !!  and ==> are rarely required anymore in inductive goals
  2761 (using object-logic connectives for this purpose has been long
  2762 obsolete anyway). Common proof patterns are explained in
  2763 src/HOL/Induct/Common_Patterns.thy, see also
  2764 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2765 examples.
  2766 
  2767 * Method "induct": improved handling of simultaneous goals. Instead of
  2768 introducing object-level conjunction, the statement is now split into
  2769 several conclusions, while the corresponding symbolic cases are nested
  2770 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2771 see src/HOL/Induct/Common_Patterns.thy, for example.
  2772 
  2773 * Method "induct": mutual induction rules are now specified as a list
  2774 of rule sharing the same induction cases. HOL packages usually provide
  2775 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2776 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2777 mutual induction rules differently, i.e. like this:
  2778 
  2779   (induct rule: foo_bar.inducts)
  2780   (induct set: foo bar)
  2781   (induct pred: foo bar)
  2782   (induct type: foo bar)
  2783 
  2784 The ML function ProjectRule.projections turns old-style rules into the
  2785 new format.
  2786 
  2787 * Method "coinduct": dual of induction, see
  2788 src/HOL/Library/Coinductive_List.thy for various examples.
  2789 
  2790 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2791 considered a legacy feature.
  2792 
  2793 * Attribute "symmetric" produces result with standardized schematic
  2794 variables (index 0).  Potential INCOMPATIBILITY.
  2795 
  2796 * Simplifier: by default the simplifier trace only shows top level
  2797 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2798 default. Thus there is less danger of being flooded by the trace. The
  2799 trace indicates where parts have been suppressed.
  2800   
  2801 * Provers/classical: removed obsolete classical version of elim_format
  2802 attribute; classical elim/dest rules are now treated uniformly when
  2803 manipulating the claset.
  2804 
  2805 * Provers/classical: stricter checks to ensure that supplied intro,
  2806 dest and elim rules are well-formed; dest and elim rules must have at
  2807 least one premise.
  2808 
  2809 * Provers/classical: attributes dest/elim/intro take an optional
  2810 weight argument for the rule (just as the Pure versions).  Weights are
  2811 ignored by automated tools, but determine the search order of single
  2812 rule steps.
  2813 
  2814 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2815 where the body does not mention the bound variable.  Note that dummy
  2816 patterns implicitly depend on their context of bounds, which makes
  2817 "{_. _}" match any set comprehension as expected.  Potential
  2818 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2819 constant "_idtdummy" in the binding position.
  2820 
  2821 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2822 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2823 for example "A -> B" => "Pi A (%_. B)".
  2824 
  2825 * Pure: 'class_deps' command visualizes the subclass relation, using
  2826 the graph browser tool.
  2827 
  2828 * Pure: 'print_theory' now suppresses certain internal declarations by
  2829 default; use '!' option for full details.
  2830 
  2831 
  2832 *** HOL ***
  2833 
  2834 * Method "metis" proves goals by applying the Metis general-purpose
  2835 resolution prover (see also http://gilith.com/software/metis/).
  2836 Examples are in the directory MetisExamples.  WARNING: the
  2837 Isabelle/HOL-Metis integration does not yet work properly with
  2838 multi-threading.
  2839   
  2840 * Command 'sledgehammer' invokes external automatic theorem provers as
  2841 background processes.  It generates calls to the "metis" method if
  2842 successful. These can be pasted into the proof.  Users do not have to
  2843 wait for the automatic provers to return.  WARNING: does not really
  2844 work with multi-threading.
  2845 
  2846 * New "auto_quickcheck" feature tests outermost goal statements for
  2847 potential counter-examples.  Controlled by ML references
  2848 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2849 5000 milliseconds).  Fails silently if statements is outside of
  2850 executable fragment, or any other codgenerator problem occurs.
  2851 
  2852 * New constant "undefined" with axiom "undefined x = undefined".
  2853 
  2854 * Added class "HOL.eq", allowing for code generation with polymorphic
  2855 equality.
  2856 
  2857 * Some renaming of class constants due to canonical name prefixing in
  2858 the new 'class' package:
  2859 
  2860     HOL.abs ~> HOL.abs_class.abs
  2861     HOL.divide ~> HOL.divide_class.divide
  2862     0 ~> HOL.zero_class.zero
  2863     1 ~> HOL.one_class.one
  2864     op + ~> HOL.plus_class.plus
  2865     op - ~> HOL.minus_class.minus
  2866     uminus ~> HOL.minus_class.uminus
  2867     op * ~> HOL.times_class.times
  2868     op < ~> HOL.ord_class.less
  2869     op <= > HOL.ord_class.less_eq
  2870     Nat.power ~> Power.power_class.power
  2871     Nat.size ~> Nat.size_class.size
  2872     Numeral.number_of ~> Numeral.number_class.number_of
  2873     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2874     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2875     Orderings.min ~> Orderings.ord_class.min
  2876     Orderings.max ~> Orderings.ord_class.max
  2877     Divides.op div ~> Divides.div_class.div
  2878     Divides.op mod ~> Divides.div_class.mod
  2879     Divides.op dvd ~> Divides.div_class.dvd
  2880 
  2881 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2882 
  2883 a) User-defined constants using any of the names "plus", "minus",
  2884 "times", "less" or "less_eq". The standard syntax translations for
  2885 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2886 names.
  2887 
  2888 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2889 INCOMPATIBILITY: use more specific names.
  2890 
  2891 c) Permutative equations (e.g. "a + b = b + a")
  2892 Since the change of names also changes the order of terms, permutative
  2893 rewrite rules may get applied in a different order. Experience shows
  2894 that this is rarely the case (only two adaptions in the whole Isabelle
  2895 distribution).  INCOMPATIBILITY: rewrite proofs
  2896 
  2897 d) ML code directly refering to constant names
  2898 This in general only affects hand-written proof tactics, simprocs and
  2899 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2900 Consider using @{const_name} antiquotation.
  2901 
  2902 * New class "default" with associated constant "default".
  2903 
  2904 * Function "sgn" is now overloaded and available on int, real, complex
  2905 (and other numeric types), using class "sgn".  Two possible defs of
  2906 sgn are given as equational assumptions in the classes sgn_if and
  2907 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2908 INCOMPATIBILITY.
  2909 
  2910 * Locale "partial_order" now unified with class "order" (cf. theory
  2911 Orderings), added parameter "less".  INCOMPATIBILITY.
  2912 
  2913 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2914 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2915 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2916 
  2917 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2918 changed order of proof goals in instance proofs.
  2919 
  2920 * The transitivity reasoner for partial and linear orders is set up
  2921 for classes "order" and "linorder".  Instances of the reasoner are available
  2922 in all contexts importing or interpreting the corresponding locales.
  2923 Method "order" invokes the reasoner separately; the reasoner
  2924 is also integrated with the Simplifier as a solver.  Diagnostic
  2925 command 'print_orders' shows the available instances of the reasoner
  2926 in the current context.
  2927 
  2928 * Localized monotonicity predicate in theory "Orderings"; integrated
  2929 lemmas max_of_mono and min_of_mono with this predicate.
  2930 INCOMPATIBILITY.
  2931 
  2932 * Formulation of theorem "dense" changed slightly due to integration
  2933 with new class dense_linear_order.
  2934 
  2935 * Uniform lattice theory development in HOL.
  2936 
  2937     constants "meet" and "join" now named "inf" and "sup"
  2938     constant "Meet" now named "Inf"
  2939 
  2940     classes "meet_semilorder" and "join_semilorder" now named
  2941       "lower_semilattice" and "upper_semilattice"
  2942     class "lorder" now named "lattice"
  2943     class "comp_lat" now named "complete_lattice"
  2944 
  2945     Instantiation of lattice classes allows explicit definitions
  2946     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2947 
  2948   INCOMPATIBILITY.  Theorem renames:
  2949 
  2950     meet_left_le            ~> inf_le1
  2951     meet_right_le           ~> inf_le2
  2952     join_left_le            ~> sup_ge1
  2953     join_right_le           ~> sup_ge2
  2954     meet_join_le            ~> inf_sup_ord
  2955     le_meetI                ~> le_infI
  2956     join_leI                ~> le_supI
  2957     le_meet                 ~> le_inf_iff
  2958     le_join                 ~> ge_sup_conv
  2959     meet_idempotent         ~> inf_idem
  2960     join_idempotent         ~> sup_idem
  2961     meet_comm               ~> inf_commute
  2962     join_comm               ~> sup_commute
  2963     meet_leI1               ~> le_infI1
  2964     meet_leI2               ~> le_infI2
  2965     le_joinI1               ~> le_supI1
  2966     le_joinI2               ~> le_supI2
  2967     meet_assoc              ~> inf_assoc
  2968     join_assoc              ~> sup_assoc
  2969     meet_left_comm          ~> inf_left_commute
  2970     meet_left_idempotent    ~> inf_left_idem
  2971     join_left_comm          ~> sup_left_commute
  2972     join_left_idempotent    ~> sup_left_idem
  2973     meet_aci                ~> inf_aci
  2974     join_aci                ~> sup_aci
  2975     le_def_meet             ~> le_iff_inf
  2976     le_def_join             ~> le_iff_sup
  2977     join_absorp2            ~> sup_absorb2
  2978     join_absorp1            ~> sup_absorb1
  2979     meet_absorp1            ~> inf_absorb1
  2980     meet_absorp2            ~> inf_absorb2
  2981     meet_join_absorp        ~> inf_sup_absorb
  2982     join_meet_absorp        ~> sup_inf_absorb
  2983     distrib_join_le         ~> distrib_sup_le
  2984     distrib_meet_le         ~> distrib_inf_le
  2985 
  2986     add_meet_distrib_left   ~> add_inf_distrib_left
  2987     add_join_distrib_left   ~> add_sup_distrib_left
  2988     is_join_neg_meet        ~> is_join_neg_inf
  2989     is_meet_neg_join        ~> is_meet_neg_sup
  2990     add_meet_distrib_right  ~> add_inf_distrib_right
  2991     add_join_distrib_right  ~> add_sup_distrib_right
  2992     add_meet_join_distribs  ~> add_sup_inf_distribs
  2993     join_eq_neg_meet        ~> sup_eq_neg_inf
  2994     meet_eq_neg_join        ~> inf_eq_neg_sup
  2995     add_eq_meet_join        ~> add_eq_inf_sup
  2996     meet_0_imp_0            ~> inf_0_imp_0
  2997     join_0_imp_0            ~> sup_0_imp_0
  2998     meet_0_eq_0             ~> inf_0_eq_0
  2999     join_0_eq_0             ~> sup_0_eq_0
  3000     neg_meet_eq_join        ~> neg_inf_eq_sup
  3001     neg_join_eq_meet        ~> neg_sup_eq_inf
  3002     join_eq_if              ~> sup_eq_if
  3003 
  3004     mono_meet               ~> mono_inf
  3005     mono_join               ~> mono_sup
  3006     meet_bool_eq            ~> inf_bool_eq
  3007     join_bool_eq            ~> sup_bool_eq
  3008     meet_fun_eq             ~> inf_fun_eq
  3009     join_fun_eq             ~> sup_fun_eq
  3010     meet_set_eq             ~> inf_set_eq
  3011     join_set_eq             ~> sup_set_eq
  3012     meet1_iff               ~> inf1_iff
  3013     meet2_iff               ~> inf2_iff
  3014     meet1I                  ~> inf1I
  3015     meet2I                  ~> inf2I
  3016     meet1D1                 ~> inf1D1
  3017     meet2D1                 ~> inf2D1
  3018     meet1D2                 ~> inf1D2
  3019     meet2D2                 ~> inf2D2
  3020     meet1E                  ~> inf1E
  3021     meet2E                  ~> inf2E
  3022     join1_iff               ~> sup1_iff
  3023     join2_iff               ~> sup2_iff
  3024     join1I1                 ~> sup1I1
  3025     join2I1                 ~> sup2I1
  3026     join1I1                 ~> sup1I1
  3027     join2I2                 ~> sup1I2
  3028     join1CI                 ~> sup1CI
  3029     join2CI                 ~> sup2CI
  3030     join1E                  ~> sup1E
  3031     join2E                  ~> sup2E
  3032 
  3033     is_meet_Meet            ~> is_meet_Inf
  3034     Meet_bool_def           ~> Inf_bool_def
  3035     Meet_fun_def            ~> Inf_fun_def
  3036     Meet_greatest           ~> Inf_greatest
  3037     Meet_lower              ~> Inf_lower
  3038     Meet_set_def            ~> Inf_set_def
  3039 
  3040     Sup_def                 ~> Sup_Inf
  3041     Sup_bool_eq             ~> Sup_bool_def
  3042     Sup_fun_eq              ~> Sup_fun_def
  3043     Sup_set_eq              ~> Sup_set_def
  3044 
  3045     listsp_meetI            ~> listsp_infI
  3046     listsp_meet_eq          ~> listsp_inf_eq
  3047 
  3048     meet_min                ~> inf_min
  3049     join_max                ~> sup_max
  3050 
  3051 * Added syntactic class "size"; overloaded constant "size" now has
  3052 type "'a::size ==> bool"
  3053 
  3054 * Internal reorganisation of `size' of datatypes: size theorems
  3055 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3056 simplification rules by default!); theorems "prod.size" now named
  3057 "*.size".
  3058 
  3059 * Class "div" now inherits from class "times" rather than "type".
  3060 INCOMPATIBILITY.
  3061 
  3062 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3063 Linorder etc.  have disappeared; operations defined in terms of
  3064 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3065 
  3066 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3067 
  3068 * HOL-Word: New extensive library and type for generic, fixed size
  3069 machine words, with arithemtic, bit-wise, shifting and rotating
  3070 operations, reflection into int, nat, and bool lists, automation for
  3071 linear arithmetic (by automatic reflection into nat or int), including
  3072 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3073 arithmetic type classes, supporting automatic simplification of
  3074 numerals on all operations.
  3075 
  3076 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3077 
  3078 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3079 
  3080 * Code generator library theories:
  3081   - Code_Integer represents HOL integers by big integer literals in target
  3082     languages.
  3083   - Code_Char represents HOL characters by character literals in target
  3084     languages.
  3085   - Code_Char_chr like Code_Char, but also offers treatment of character
  3086     codes; includes Code_Integer.
  3087   - Executable_Set allows to generate code for finite sets using lists.
  3088   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3089     denominator).
  3090   - Executable_Real implements a subset of real numbers, namly those
  3091     representable by rational numbers.
  3092   - Efficient_Nat implements natural numbers by integers, which in general will
  3093     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3094     includes Code_Integer.
  3095   - Code_Index provides an additional datatype index which is mapped to
  3096     target-language built-in integers.
  3097   - Code_Message provides an additional datatype message_string which is isomorphic to
  3098     strings; messages are mapped to target-language strings.
  3099 
  3100 * New package for inductive predicates
  3101 
  3102   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3103 
  3104     inductive
  3105       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3106       for z_1 :: U_1 and ... and z_n :: U_m
  3107     where
  3108       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3109     | ...
  3110 
  3111   with full support for type-inference, rather than
  3112 
  3113     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3114 
  3115     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3116     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3117 
  3118     inductive "s z_1 ... z_m"
  3119     intros
  3120       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3121       ...
  3122 
  3123   For backward compatibility, there is a wrapper allowing inductive
  3124   sets to be defined with the new package via
  3125 
  3126     inductive_set
  3127       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3128       for z_1 :: U_1 and ... and z_n :: U_m
  3129     where
  3130       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3131     | ...
  3132 
  3133   or
  3134 
  3135     inductive_set
  3136       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3137       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3138       for z_1 :: U_1 and ... and z_n :: U_m
  3139     where
  3140       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3141     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3142     | ...
  3143 
  3144   if the additional syntax "p ..." is required.
  3145 
  3146   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3147   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3148 
  3149   INCOMPATIBILITIES:
  3150 
  3151   - Since declaration and definition of inductive sets or predicates
  3152     is no longer separated, abbreviations involving the newly
  3153     introduced sets or predicates must be specified together with the
  3154     introduction rules after the 'where' keyword (see above), rather
  3155     than before the actual inductive definition.
  3156 
  3157   - The variables in induction and elimination rules are now
  3158     quantified in the order of their occurrence in the introduction
  3159     rules, rather than in alphabetical order. Since this may break
  3160     some proofs, these proofs either have to be repaired, e.g. by
  3161     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3162     statements of the form
  3163 
  3164       case (rule_i a_i_1 ... a_i_{k_i})
  3165 
  3166     or the old order of quantification has to be restored by explicitly adding
  3167     meta-level quantifiers in the introduction rules, i.e.
  3168 
  3169       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3170 
  3171   - The format of the elimination rules is now
  3172 
  3173       p z_1 ... z_m x_1 ... x_n ==>
  3174         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3175         ==> ... ==> P
  3176 
  3177     for predicates and
  3178 
  3179       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3180         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3181         ==> ... ==> P
  3182 
  3183     for sets rather than
  3184 
  3185       x : s z_1 ... z_m ==>
  3186         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3187         ==> ... ==> P
  3188 
  3189     This may require terms in goals to be expanded to n-tuples
  3190     (e.g. using case_tac or simplification with the split_paired_all
  3191     rule) before the above elimination rule is applicable.
  3192 
  3193   - The elimination or case analysis rules for (mutually) inductive
  3194     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3195     list of rules "p_1_..._p_k.elims" is no longer available.
  3196 
  3197 * New package "function"/"fun" for general recursive functions,
  3198 supporting mutual and nested recursion, definitions in local contexts,
  3199 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3200 for small examples, and the separate tutorial on the function
  3201 package. The old recdef "package" is still available as before, but
  3202 users are encouraged to use the new package.
  3203 
  3204 * Method "lexicographic_order" automatically synthesizes termination
  3205 relations as lexicographic combinations of size measures. 
  3206 
  3207 * Case-expressions allow arbitrary constructor-patterns (including
  3208 "_") and take their order into account, like in functional
  3209 programming.  Internally, this is translated into nested
  3210 case-expressions; missing cases are added and mapped to the predefined
  3211 constant "undefined". In complicated cases printing may no longer show
  3212 the original input but the internal form. Lambda-abstractions allow
  3213 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3214 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3215 variable.
  3216 
  3217 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3218 is an abbreviation for "of_nat :: nat => int". The simplification
  3219 rules for "of_nat" have been changed to work like "int" did
  3220 previously.  Potential INCOMPATIBILITY:
  3221   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3222   - of_nat_diff and of_nat_mult are no longer default simp rules
  3223 
  3224 * Method "algebra" solves polynomial equations over (semi)rings using
  3225 Groebner bases. The (semi)ring structure is defined by locales and the
  3226 tool setup depends on that generic context. Installing the method for
  3227 a specific type involves instantiating the locale and possibly adding
  3228 declarations for computation on the coefficients.  The method is
  3229 already instantiated for natural numbers and for the axiomatic class
  3230 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3231 CALCULEMUS 2007 for the general principles underlying this
  3232 architecture of context-aware proof-tools.
  3233 
  3234 * Method "ferrack" implements quantifier elimination over
  3235 special-purpose dense linear orders using locales (analogous to
  3236 "algebra"). The method is already installed for class
  3237 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3238 rat, etc.
  3239 
  3240 * Former constant "List.op @" now named "List.append".  Use ML
  3241 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3242 circumvent possible incompatibilities when working on ML level.
  3243 
  3244 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3245 
  3246 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3247 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3248 
  3249 * New syntax for Haskell-like list comprehension (input only), eg.
  3250 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3251 
  3252 * The special syntax for function "filter" has changed from [x :
  3253 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3254 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3255 
  3256 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3257 defined on nat only, as an abbreviation for [a..<Suc b]
  3258 INCOMPATIBILITY.
  3259 
  3260 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3261 
  3262 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3263 
  3264 * New lemma collection field_simps (an extension of ring_simps) for
  3265 manipulating (in)equations involving division. Multiplies with all
  3266 denominators that can be proved to be non-zero (in equations) or
  3267 positive/negative (in inequations).
  3268 
  3269 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3270 have been improved and renamed to ring_simps, group_simps and
  3271 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3272 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3273 
  3274 * Theory Library/Commutative_Ring: switched from recdef to function
  3275 package; constants add, mul, pow now curried.  Infix syntax for
  3276 algebraic operations.
  3277 
  3278 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3279 INCOMPATIBILITY.
  3280 
  3281 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3282 INCOMPATIBILITY.
  3283 
  3284 * HOL/records: generalised field-update to take a function on the
  3285 field rather than the new value: r(|A := x|) is translated to A_update
  3286 (K x) r The K-combinator that is internally used is called K_record.
  3287 INCOMPATIBILITY: Usage of the plain update functions has to be
  3288 adapted.
  3289  
  3290 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3291 * x = 0, which are required for a semiring.  Richer structures do not
  3292 inherit from semiring_0 anymore, because this property is a theorem
  3293 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3294 there is more to prove, but this is mostly trivial.
  3295 
  3296 * Class "recpower" is generalized to arbitrary monoids, not just
  3297 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3298 commutativity or semiring properties additionally.
  3299 
  3300 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3301 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3302 better use 'abbreviation'.
  3303 
  3304 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3305 
  3306 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3307 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3308 significant changes for setting up numeral syntax for types:
  3309   - New constants Numeral.pred and Numeral.succ instead
  3310       of former Numeral.bin_pred and Numeral.bin_succ.
  3311   - Use integer operations instead of bin_add, bin_mult and so on.
  3312   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3313   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3314 
  3315 See src/HOL/Integ/IntArith.thy for an example setup.
  3316 
  3317 * Command 'normal_form' computes the normal form of a term that may
  3318 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3319 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3320 heavy-duty computations because the functions are compiled to ML
  3321 first.  Correspondingly, a method "normalization" is provided.  See
  3322 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3323 
  3324 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3325 25 like -->); output depends on the "iff" print_mode, the default is
  3326 "A = B" (with priority 50).
  3327 
  3328 * Relations less (<) and less_eq (<=) are also available on type bool.
  3329 Modified syntax to disallow nesting without explicit parentheses,
  3330 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3331 INCOMPATIBILITY.
  3332 
  3333 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3334 
  3335 * Relation composition operator "op O" now has precedence 75 and binds
  3336 stronger than union and intersection. INCOMPATIBILITY.
  3337 
  3338 * The old set interval syntax "{m..n(}" (and relatives) has been
  3339 removed.  Use "{m..<n}" (and relatives) instead.
  3340 
  3341 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3342 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3343 ``declare [[simproc del: neq]]''.
  3344 
  3345 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3346 True/False.
  3347 
  3348 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3349 
  3350 * Theorem setsum_mult renamed to setsum_right_distrib.
  3351 
  3352 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3353 ``rule'' method.
  3354 
  3355 * Reimplemented methods "sat" and "satx", with several improvements:
  3356 goals no longer need to be stated as "<prems> ==> False", equivalences
  3357 (i.e. "=" on type bool) are handled, variable names of the form
  3358 "lit_<n>" are no longer reserved, significant speedup.
  3359 
  3360 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3361 zChaff is still supported as well.
  3362 
  3363 * 'inductive' and 'datatype': provide projections of mutual rules,
  3364 bundled as foo_bar.inducts;
  3365 
  3366 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3367 Library.
  3368 
  3369 * Library: moved theory Accessible_Part to main HOL.
  3370 
  3371 * Library: added theory Coinductive_List of potentially infinite lists
  3372 as greatest fixed-point.
  3373 
  3374 * Library: added theory AssocList which implements (finite) maps as
  3375 association lists.
  3376 
  3377 * Method "evaluation" solves goals (i.e. a boolean expression)
  3378 efficiently by compiling it to ML.  The goal is "proved" (via an
  3379 oracle) if it evaluates to True.
  3380 
  3381 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3382 also when invoked by the simplifier.  This results in the Simplifier
  3383 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3384 Configuration option fast_arith_split_limit=0 recovers the old
  3385 behavior.
  3386 
  3387 * Support for hex (0x20) and binary (0b1001) numerals.
  3388 
  3389 * New method: reify eqs (t), where eqs are equations for an
  3390 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3391 parameter, computes a term s::'b and a list xs::'a list and proves the
  3392 theorem I xs s = t. This is also known as reification or quoting. The
  3393 resulting theorem is applied to the subgoal to substitute t with I xs
  3394 s.  If t is omitted, the subgoal itself is reified.
  3395 
  3396 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3397 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3398 where f is supposed to be a computable function (in the sense of code
  3399 generattion). The method uses reify to compute s and xs as above then
  3400 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3401 r and finally gets the theorem t = r, which is again applied to the
  3402 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3403 
  3404 * Reflection: Automatic reification now handels binding, an example is
  3405 available in src/HOL/ex/ReflectionEx.thy
  3406 
  3407 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3408 command 'statespace' that is similar to 'record', but introduces an
  3409 abstract specification based on the locale infrastructure instead of
  3410 HOL types.  This leads to extra flexibility in composing state spaces,
  3411 in particular multiple inheritance and renaming of components.
  3412 
  3413 
  3414 *** HOL-Complex ***
  3415 
  3416 * Hyperreal: Functions root and sqrt are now defined on negative real
  3417 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3418 Nonnegativity side conditions have been removed from many lemmas, so
  3419 that more subgoals may now be solved by simplification; potential
  3420 INCOMPATIBILITY.
  3421 
  3422 * Real: new type classes formalize real normed vector spaces and
  3423 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3424 and norm :: 'a => real.
  3425 
  3426 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3427 reals into other types. The overloaded constant Reals :: 'a set is now
  3428 defined as range of_real; potential INCOMPATIBILITY.
  3429 
  3430 * Real: proper support for ML code generation, including 'quickcheck'.
  3431 Reals are implemented as arbitrary precision rationals.
  3432 
  3433 * Hyperreal: Several constants that previously worked only for the
  3434 reals have been generalized, so they now work over arbitrary vector
  3435 spaces. Type annotations may need to be added in some cases; potential
  3436 INCOMPATIBILITY.
  3437 
  3438   Infinitesimal  :: ('a::real_normed_vector) star set
  3439   HFinite        :: ('a::real_normed_vector) star set
  3440   HInfinite      :: ('a::real_normed_vector) star set
  3441   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3442   monad          :: ('a::real_normed_vector) star => 'a star set
  3443   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3444   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3445   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3446   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3447   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3448   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3449   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3450   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3451   sgn            :: 'a::real_normed_vector => 'a
  3452   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3453 
  3454 * Complex: Some complex-specific constants are now abbreviations for
  3455 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3456 hnorm.  Other constants have been entirely removed in favor of the
  3457 polymorphic versions (INCOMPATIBILITY):
  3458 
  3459   approx        <-- capprox
  3460   HFinite       <-- CFinite
  3461   HInfinite     <-- CInfinite
  3462   Infinitesimal <-- CInfinitesimal
  3463   monad         <-- cmonad
  3464   galaxy        <-- cgalaxy
  3465   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3466   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3467   (ns)deriv     <-- (ns)cderiv
  3468 
  3469 
  3470 *** HOL-Algebra ***
  3471 
  3472 * Formalisation of ideals and the quotient construction over rings.
  3473 
  3474 * Order and lattice theory no longer based on records.
  3475 INCOMPATIBILITY.
  3476 
  3477 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3478 greatest_closed.  INCOMPATIBILITY.
  3479 
  3480 * Method algebra is now set up via an attribute.  For examples see
  3481 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3482 of algebraic structures.
  3483 
  3484 * Renamed theory CRing to Ring.
  3485 
  3486 
  3487 *** HOL-Nominal ***
  3488 
  3489 * Substantial, yet incomplete support for nominal datatypes (binding
  3490 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3491 src/HOL/Nominal/Examples.  Prospective users should consult
  3492 http://isabelle.in.tum.de/nominal/
  3493 
  3494 
  3495 *** ML ***
  3496 
  3497 * ML basics: just one true type int, which coincides with IntInf.int
  3498 (even on SML/NJ).
  3499 
  3500 * ML within Isar: antiquotations allow to embed statically-checked
  3501 formal entities in the source, referring to the context available at
  3502 compile-time.  For example:
  3503 
  3504 ML {* @{sort "{zero,one}"} *}
  3505 ML {* @{typ "'a => 'b"} *}
  3506 ML {* @{term "%x. x"} *}
  3507 ML {* @{prop "x == y"} *}
  3508 ML {* @{ctyp "'a => 'b"} *}
  3509 ML {* @{cterm "%x. x"} *}
  3510 ML {* @{cprop "x == y"} *}
  3511 ML {* @{thm asm_rl} *}
  3512 ML {* @{thms asm_rl} *}
  3513 ML {* @{type_name c} *}
  3514 ML {* @{type_syntax c} *}
  3515 ML {* @{const_name c} *}
  3516 ML {* @{const_syntax c} *}
  3517 ML {* @{context} *}
  3518 ML {* @{theory} *}
  3519 ML {* @{theory Pure} *}
  3520 ML {* @{theory_ref} *}
  3521 ML {* @{theory_ref Pure} *}
  3522 ML {* @{simpset} *}
  3523 ML {* @{claset} *}
  3524 ML {* @{clasimpset} *}
  3525 
  3526 The same works for sources being ``used'' within an Isar context.
  3527 
  3528 * ML in Isar: improved error reporting; extra verbosity with
  3529 ML_Context.trace enabled.
  3530 
  3531 * Pure/General/table.ML: the join operations now works via exceptions
  3532 DUP/SAME instead of type option. This is simpler in simple cases, and
  3533 admits slightly more efficient complex applications.
  3534 
  3535 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3536 use Context.generic instead of just theory.
  3537 
  3538 * Pure: datatype Context.generic joins theory/Proof.context and
  3539 provides some facilities for code that works in either kind of
  3540 context, notably GenericDataFun for uniform theory and proof data.
  3541 
  3542 * Pure: simplified internal attribute type, which is now always
  3543 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3544 local (Proof.context) attributes have been discontinued, while
  3545 minimizing code duplication. Thm.rule_attribute and
  3546 Thm.declaration_attribute build canonical attributes; see also structure
  3547 Context for further operations on Context.generic, notably
  3548 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3549 declarations and definitions.
  3550 
  3551 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3552 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3553 init only required for impure data. INCOMPATIBILITY: empty really need
  3554 to be empty (no dependencies on theory content!)
  3555 
  3556 * Pure/kernel: consts certification ignores sort constraints given in
  3557 signature declarations. (This information is not relevant to the
  3558 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3559 potential INCOMPATIBILITY.
  3560 
  3561 * Pure: axiomatic type classes are now purely definitional, with
  3562 explicit proofs of class axioms and super class relations performed
  3563 internally. See Pure/axclass.ML for the main internal interfaces --
  3564 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3565 AxClass.axiomatize_class/classrel/arity supersede
  3566 Sign.add_classes/classrel/arities.
  3567 
  3568 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3569 global/local versions on theory vs. Proof.context have been
  3570 discontinued; Attrib.syntax and Method.syntax have been adapted
  3571 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3572 attributes, methods, etc.
  3573 
  3574 * Pure: several functions of signature "... -> theory -> theory * ..."
  3575 have been reoriented to "... -> theory -> ... * theory" in order to
  3576 allow natural usage in combination with the ||>, ||>>, |-> and
  3577 fold_map combinators.
  3578 
  3579 * Pure: official theorem names (closed derivations) and additional
  3580 comments (tags) are now strictly separate.  Name hints -- which are
  3581 maintained as tags -- may be attached any time without affecting the
  3582 derivation.
  3583 
  3584 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3585 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3586 achieve the old behaviour.
  3587 
  3588 * Pure: the "Goal" constant is now called "prop", supporting a
  3589 slightly more general idea of ``protecting'' meta-level rule
  3590 statements.
  3591 
  3592 * Pure: Logic.(un)varify only works in a global context, which is now
  3593 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3594 Logic.legacy_(un)varify as temporary workaround.
  3595 
  3596 * Pure: structure Name provides scalable operations for generating
  3597 internal variable names, notably Name.variants etc.  This replaces
  3598 some popular functions from term.ML:
  3599 
  3600   Term.variant		->  Name.variant
  3601   Term.variantlist	->  Name.variant_list
  3602   Term.invent_names	->  Name.invent_list
  3603 
  3604 Note that low-level renaming rarely occurs in new code -- operations
  3605 from structure Variable are used instead (see below).
  3606 
  3607 * Pure: structure Variable provides fundamental operations for proper
  3608 treatment of fixed/schematic variables in a context.  For example,
  3609 Variable.import introduces fixes for schematics of given facts and
  3610 Variable.export reverses the effect (up to renaming) -- this replaces
  3611 various freeze_thaw operations.
  3612 
  3613 * Pure: structure Goal provides simple interfaces for
  3614 init/conclude/finish and tactical prove operations (replacing former
  3615 Tactic.prove).  Goal.prove is the canonical way to prove results
  3616 within a given context; Goal.prove_global is a degraded version for
  3617 theory level goals, including a global Drule.standard.  Note that
  3618 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3619 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3620 in a locale context).
  3621 
  3622 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3623 and type checking (Syntax.check_term etc.), with common combinations
  3624 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3625 which are considered legacy and await removal.
  3626 
  3627 * Pure/Syntax: generic interfaces for type unchecking
  3628 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3629 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3630 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3631 available for convenience, but refer to the very same operations using
  3632 a mere theory instead of a full context.
  3633 
  3634 * Isar: simplified treatment of user-level errors, using exception
  3635 ERROR of string uniformly.  Function error now merely raises ERROR,
  3636 without any side effect on output channels.  The Isar toplevel takes
  3637 care of proper display of ERROR exceptions.  ML code may use plain
  3638 handle/can/try; cat_error may be used to concatenate errors like this:
  3639 
  3640   ... handle ERROR msg => cat_error msg "..."
  3641 
  3642 Toplevel ML code (run directly or through the Isar toplevel) may be
  3643 embedded into the Isar toplevel with exception display/debug like
  3644 this:
  3645 
  3646   Isar.toplevel (fn () => ...)
  3647 
  3648 INCOMPATIBILITY, removed special transform_error facilities, removed
  3649 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3650 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3651 -- use plain ERROR instead.
  3652 
  3653 * Isar: theory setup now has type (theory -> theory), instead of a
  3654 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3655 
  3656 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3657 ProofContext.debug/verbose flags.
  3658 
  3659 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3660 theory before entering a proof state.  Transactions now always see a
  3661 quasi-functional intermediate checkpoint, both in interactive and
  3662 batch mode.
  3663 
  3664 * Isar: simplified interfaces for outer syntax.  Renamed
  3665 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3666 OuterSyntax.add_parsers -- this functionality is now included in
  3667 OuterSyntax.command etc.  INCOMPATIBILITY.
  3668 
  3669 * Simplifier: the simpset of a running simplification process now
  3670 contains a proof context (cf. Simplifier.the_context), which is the
  3671 very context that the initial simpset has been retrieved from (by
  3672 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3673 (solver, looper etc.) may depend on arbitrary proof data.
  3674 
  3675 * Simplifier.inherit_context inherits the proof context (plus the
  3676 local bounds) of the current simplification process; any simproc
  3677 etc. that calls the Simplifier recursively should do this!  Removed
  3678 former Simplifier.inherit_bounds, which is already included here --
  3679 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3680 specify an explicit context using Simplifier.context/theory_context.
  3681 
  3682 * Simplifier/Classical Reasoner: more abstract interfaces
  3683 change_simpset/claset for modifying the simpset/claset reference of a
  3684 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3685 INCOMPATIBILITY.
  3686 
  3687 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3688 "Trueprop" etc.
  3689 
  3690 
  3691 *** System ***
  3692 
  3693 * settings: the default heap location within ISABELLE_HOME_USER now
  3694 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3695 Isabelle installations.
  3696 
  3697 * isabelle-process: option -S (secure mode) disables some critical
  3698 operations, notably runtime compilation and evaluation of ML source
  3699 code.
  3700 
  3701 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3702 
  3703 * Support for parallel execution, using native multicore support of
  3704 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3705 independent theories, according to the given theory header
  3706 specifications. The maximum number of worker threads is specified via
  3707 usedir option -M or the "max-threads" setting in Proof General. A
  3708 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3709 to 6 on a 8-core machine.  User-code needs to observe certain
  3710 guidelines for thread-safe programming, see appendix A in the Isar
  3711 Implementation manual.
  3712 
  3713 
  3714 
  3715 New in Isabelle2005 (October 2005)
  3716 ----------------------------------
  3717 
  3718 *** General ***
  3719 
  3720 * Theory headers: the new header syntax for Isar theories is
  3721 
  3722   theory <name>
  3723   imports <theory1> ... <theoryN>
  3724   uses <file1> ... <fileM>
  3725   begin
  3726 
  3727 where the 'uses' part is optional.  The previous syntax
  3728 
  3729   theory <name> = <theory1> + ... + <theoryN>:
  3730 
  3731 will disappear in the next release.  Use isatool fixheaders to convert
  3732 existing theory files.  Note that there is no change in ancient
  3733 non-Isar theories now, but these will disappear soon.
  3734 
  3735 * Theory loader: parent theories can now also be referred to via
  3736 relative and absolute paths.
  3737 
  3738 * Command 'find_theorems' searches for a list of criteria instead of a
  3739 list of constants. Known criteria are: intro, elim, dest, name:string,
  3740 simp:term, and any term. Criteria can be preceded by '-' to select
  3741 theorems that do not match. Intro, elim, dest select theorems that
  3742 match the current goal, name:s selects theorems whose fully qualified
  3743 name contain s, and simp:term selects all simplification rules whose
  3744 lhs match term.  Any other term is interpreted as pattern and selects
  3745 all theorems matching the pattern. Available in ProofGeneral under
  3746 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3747 
  3748   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3749 
  3750 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3751 matching the current goal as introduction rule and not having "HOL."
  3752 in their name (i.e. not being defined in theory HOL).
  3753 
  3754 * Command 'thms_containing' has been discontinued in favour of
  3755 'find_theorems'; INCOMPATIBILITY.
  3756 
  3757 * Communication with Proof General is now 8bit clean, which means that
  3758 Unicode text in UTF-8 encoding may be used within theory texts (both
  3759 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3760 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3761 
  3762   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3763   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3764 
  3765 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3766 Classical Reasoner.  Typical big applications run around 2 times
  3767 faster.
  3768 
  3769 
  3770 *** Document preparation ***
  3771 
  3772 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3773 of raw sources.  Only those symbols that do not require additional
  3774 LaTeX packages (depending on comments in isabellesym.sty) are
  3775 displayed properly, everything else is left verbatim.  isatool display
  3776 and isatool print are used as front ends (these are subject to the
  3777 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3778 
  3779 * Command tags control specific markup of certain regions of text,
  3780 notably folding and hiding.  Predefined tags include "theory" (for
  3781 theory begin and end), "proof" for proof commands, and "ML" for
  3782 commands involving ML code; the additional tags "visible" and
  3783 "invisible" are unused by default.  Users may give explicit tag
  3784 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3785 interpretation of tags is determined by the LaTeX job during document
  3786 preparation: see option -V of isatool usedir, or options -n and -t of
  3787 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3788 \isadroptag.
  3789 
  3790 Several document versions may be produced at the same time via isatool
  3791 usedir (the generated index.html will link all of them).  Typical
  3792 specifications include ''-V document=theory,proof,ML'' to present
  3793 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3794 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3795 these parts without any formal replacement text.  The Isabelle site
  3796 default settings produce ''document'' and ''outline'' versions as
  3797 specified above.
  3798 
  3799 * Several new antiquotations:
  3800 
  3801   @{term_type term} prints a term with its type annotated;
  3802 
  3803   @{typeof term} prints the type of a term;
  3804 
  3805   @{const const} is the same as @{term const}, but checks that the
  3806   argument is a known logical constant;
  3807 
  3808   @{term_style style term} and @{thm_style style thm} print a term or
  3809   theorem applying a "style" to it
  3810 
  3811   @{ML text}
  3812 
  3813 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3814 definitions, equations, inequations etc., 'concl' printing only the
  3815 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3816 to print the specified premise.  TermStyle.add_style provides an ML
  3817 interface for introducing further styles.  See also the "LaTeX Sugar"
  3818 document practical applications.  The ML antiquotation prints
  3819 type-checked ML expressions verbatim.
  3820 
  3821 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3822 and 'text' support optional locale specification '(in loc)', which
  3823 specifies the default context for interpreting antiquotations.  For
  3824 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3825 
  3826 * Option 'locale=NAME' of antiquotations specifies an alternative
  3827 context interpreting the subsequent argument.  For example: @{thm
  3828 [locale=lattice] inf_assoc}.
  3829 
  3830 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3831 a proof context.
  3832 
  3833 * Proper output of antiquotations for theory commands involving a
  3834 proof context (such as 'locale' or 'theorem (in loc) ...').
  3835 
  3836 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3837 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3838 
  3839 * isatool usedir: new option -C (default true) controls whether option
  3840 -D should include a copy of the original document directory; -C false
  3841 prevents unwanted effects such as copying of administrative CVS data.
  3842 
  3843 
  3844 *** Pure ***
  3845 
  3846 * Considerably improved version of 'constdefs' command.  Now performs
  3847 automatic type-inference of declared constants; additional support for
  3848 local structure declarations (cf. locales and HOL records), see also
  3849 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3850 sequential dependencies of definitions within a single 'constdefs'
  3851 section; moreover, the declared name needs to be an identifier.  If
  3852 all fails, consider to fall back on 'consts' and 'defs' separately.
  3853 
  3854 * Improved indexed syntax and implicit structures.  First of all,
  3855 indexed syntax provides a notational device for subscripted
  3856 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3857 expressions.  Secondly, in a local context with structure
  3858 declarations, number indexes \<^sub>n or the empty index (default
  3859 number 1) refer to a certain fixed variable implicitly; option
  3860 show_structs controls printing of implicit structures.  Typical
  3861 applications of these concepts involve record types and locales.
  3862 
  3863 * New command 'no_syntax' removes grammar declarations (and
  3864 translations) resulting from the given syntax specification, which is
  3865 interpreted in the same manner as for the 'syntax' command.
  3866 
  3867 * 'Advanced' translation functions (parse_translation etc.) may depend
  3868 on the signature of the theory context being presently used for
  3869 parsing/printing, see also isar-ref manual.
  3870 
  3871 * Improved 'oracle' command provides a type-safe interface to turn an
  3872 ML expression of type theory -> T -> term into a primitive rule of
  3873 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3874 is already included here); see also FOL/ex/IffExample.thy;
  3875 INCOMPATIBILITY.
  3876 
  3877 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3878 before); "cI" is no longer bound, use "c.intro" instead.
  3879 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3880 axclasses vs. locales.
  3881 
  3882 * Improved internal renaming of symbolic identifiers -- attach primes
  3883 instead of base 26 numbers.
  3884 
  3885 * New flag show_question_marks controls printing of leading question
  3886 marks in schematic variable names.
  3887 
  3888 * In schematic variable names, *any* symbol following \<^isub> or
  3889 \<^isup> is now treated as part of the base name.  For example, the
  3890 following works without printing of awkward ".0" indexes:
  3891 
  3892   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3893     by simp
  3894 
  3895 * Inner syntax includes (*(*nested*) comments*).
  3896 
  3897 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3898 annotations as "(00...)".
  3899 
  3900 * Clear separation of logical types and nonterminals, where the latter
  3901 may only occur in 'syntax' specifications or type abbreviations.
  3902 Before that distinction was only partially implemented via type class
  3903 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3904 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3905 exotic syntax specifications may require further adaption
  3906 (e.g. Cube/Cube.thy).
  3907 
  3908 * Removed obsolete type class "logic", use the top sort {} instead.
  3909 Note that non-logical types should be declared as 'nonterminals'
  3910 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3911 specifications.
  3912 
  3913 * Attributes 'induct' and 'cases': type or set names may now be
  3914 locally fixed variables as well.
  3915 
  3916 * Simplifier: can now control the depth to which conditional rewriting
  3917 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3918 Limit.
  3919 
  3920 * Simplifier: simplification procedures may now take the current
  3921 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3922 interface), which is very useful for calling the Simplifier
  3923 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3924 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3925 low-level mk_simproc no longer applies Logic.varify internally, to
  3926 allow for use in a context of fixed variables.
  3927 
  3928 * thin_tac now works even if the assumption being deleted contains !!
  3929 or ==>.  More generally, erule now works even if the major premise of
  3930 the elimination rule contains !! or ==>.
  3931 
  3932 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3933 
  3934 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3935 from Pure, which contains all common declarations already.  Both
  3936 theories are defined via plain Isabelle/Isar .thy files.
  3937 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3938 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3939 use isatool fixcpure to adapt your theory and ML sources.
  3940 
  3941 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3942 selections of theorems in named facts via index ranges.
  3943 
  3944 * 'print_theorems': in theory mode, really print the difference
  3945 wrt. the last state (works for interactive theory development only),
  3946 in proof mode print all local facts (cf. 'print_facts');
  3947 
  3948 * 'hide': option '(open)' hides only base names.
  3949 
  3950 * More efficient treatment of intermediate checkpoints in interactive
  3951 theory development.
  3952 
  3953 * Code generator is now invoked via code_module (incremental code
  3954 generation) and code_library (modular code generation, ML structures
  3955 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3956 must be quoted when used as identifiers.
  3957 
  3958 * New 'value' command for reading, evaluating and printing terms using
  3959 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3960 quoted when used as identifier.
  3961 
  3962 
  3963 *** Locales ***
  3964 
  3965 * New commands for the interpretation of locale expressions in
  3966 theories (1), locales (2) and proof contexts (3).  These generate
  3967 proof obligations from the expression specification.  After the
  3968 obligations have been discharged, theorems of the expression are added
  3969 to the theory, target locale or proof context.  The synopsis of the
  3970 commands is a follows:
  3971 
  3972   (1) interpretation expr inst
  3973   (2) interpretation target < expr
  3974   (3) interpret expr inst
  3975 
  3976 Interpretation in theories and proof contexts require a parameter
  3977 instantiation of terms from the current context.  This is applied to
  3978 specifications and theorems of the interpreted expression.
  3979 Interpretation in locales only permits parameter renaming through the
  3980 locale expression.  Interpretation is smart in that interpretations
  3981 that are active already do not occur in proof obligations, neither are
  3982 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3983 inspect active interpretations of a particular locale.  For details,
  3984 see the Isar Reference manual.  Examples can be found in
  3985 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3986 
  3987 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3988 'interpret' instead.
  3989 
  3990 * New context element 'constrains' for adding type constraints to
  3991 parameters.
  3992 
  3993 * Context expressions: renaming of parameters with syntax
  3994 redeclaration.
  3995 
  3996 * Locale declaration: 'includes' disallowed.
  3997 
  3998 * Proper static binding of attribute syntax -- i.e. types / terms /
  3999 facts mentioned as arguments are always those of the locale definition
  4000 context, independently of the context of later invocations.  Moreover,
  4001 locale operations (renaming and type / term instantiation) are applied
  4002 to attribute arguments as expected.
  4003 
  4004 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4005 actual attributes; rare situations may require Attrib.attribute to
  4006 embed those attributes into Attrib.src that lack concrete syntax.
  4007 Attribute implementations need to cooperate properly with the static
  4008 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4009 Attrib.XXX_thm etc. already do the right thing without further
  4010 intervention.  Only unusual applications -- such as "where" or "of"
  4011 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4012 on the context and the facts involved -- may have to assign parsed
  4013 values to argument tokens explicitly.
  4014 
  4015 * Changed parameter management in theorem generation for long goal
  4016 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4017 theorem statement in rare situations.
  4018 
  4019 * Locale inspection command 'print_locale' omits notes elements.  Use
  4020 'print_locale!' to have them included in the output.
  4021 
  4022 
  4023 *** Provers ***
  4024 
  4025 * Provers/hypsubst.ML: improved version of the subst method, for
  4026 single-step rewriting: it now works in bound variable contexts. New is
  4027 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4028 rewrite a different subterm than the original subst method, which is
  4029 still available as 'simplesubst'.
  4030 
  4031 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4032 and quasi orders.
  4033 
  4034 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4035 reflexive-transitive closure of relations.
  4036 
  4037 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4038 limit (previously hard-coded with a value of 20) user-definable.
  4039 
  4040 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4041 is peformed already.  Object-logics merely need to finish their
  4042 initial simpset configuration as before.  INCOMPATIBILITY.
  4043 
  4044 
  4045 *** HOL ***
  4046 
  4047 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4048 
  4049   syntax (epsilon)
  4050     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4051 
  4052 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4053 and x-symbol; use option '-m epsilon' to get it actually printed.
  4054 Moreover, the mathematically important symbolic identifier \<epsilon>
  4055 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4056 
  4057 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4058 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4059 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4060 support corresponding Isar calculations.
  4061 
  4062 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4063 instead of ":".
  4064 
  4065 * theory SetInterval: changed the syntax for open intervals:
  4066 
  4067   Old       New
  4068   {..n(}    {..<n}
  4069   {)n..}    {n<..}
  4070   {m..n(}   {m..<n}
  4071   {)m..n}   {m<..n}
  4072   {)m..n(}  {m<..<n}
  4073 
  4074 The old syntax is still supported but will disappear in the next
  4075 release.  For conversion use the following Emacs search and replace
  4076 patterns (these are not perfect but work quite well):
  4077 
  4078   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4079   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4080 
  4081 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4082 equalities in commutative rings; method 'algebra' provides a generic
  4083 interface.
  4084 
  4085 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4086 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4087 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4088 be a tuple pattern.
  4089 
  4090 Some new syntax forms are available:
  4091 
  4092   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4093   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4094   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4095   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4096 
  4097 The latter form "\<Sum>x < k. e" used to be based on a separate
  4098 function "Summation", which has been discontinued.
  4099 
  4100 * theory Finite_Set: in structured induction proofs, the insert case
  4101 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4102 (insert F x)'.
  4103 
  4104 * The 'refute' command has been extended to support a much larger
  4105 fragment of HOL, including axiomatic type classes, constdefs and
  4106 typedefs, inductive datatypes and recursion.
  4107 
  4108 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4109 Requires zChaff with proof generation to be installed.  See
  4110 HOL/ex/SAT_Examples.thy for examples.
  4111 
  4112 * Datatype induction via method 'induct' now preserves the name of the
  4113 induction variable. For example, when proving P(xs::'a list) by
  4114 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4115 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4116 in unstructured proof scripts.
  4117 
  4118 * Reworked implementation of records.  Improved scalability for
  4119 records with many fields, avoiding performance problems for type
  4120 inference. Records are no longer composed of nested field types, but
  4121 of nested extension types. Therefore the record type only grows linear
  4122 in the number of extensions and not in the number of fields.  The
  4123 top-level (users) view on records is preserved.  Potential
  4124 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4125 old record representation. The type generated for a record is called
  4126 <record_name>_ext_type.
  4127 
  4128 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4129 proofs triggered by a record definition or a simproc (if
  4130 quick_and_dirty is enabled).  Definitions of large records can take
  4131 quite long.
  4132 
  4133 New simproc record_upd_simproc for simplification of multiple record
  4134 updates enabled by default.  Moreover, trivial updates are also
  4135 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4136 occasionally, since simplification is more powerful by default.
  4137 
  4138 * typedef: proper support for polymorphic sets, which contain extra
  4139 type-variables in the term.
  4140 
  4141 * Simplifier: automatically reasons about transitivity chains
  4142 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4143 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4144 old proofs break occasionally as simplification may now solve more
  4145 goals than previously.
  4146 
  4147 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4148 present.  Works for all partial orders (class "order"), in particular
  4149 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4150 just like y <= x.
  4151 
  4152 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4153 bound variable or a constant then the let is unfolded.  Otherwise
  4154 first a is simplified to b, and then f b is simplified to g. If
  4155 possible we abstract b from g arriving at "let x = b in h x",
  4156 otherwise we unfold the let and arrive at g.  The simproc can be
  4157 enabled/disabled by the reference use_let_simproc.  Potential
  4158 INCOMPATIBILITY since simplification is more powerful by default.
  4159 
  4160 * Classical reasoning: the meson method now accepts theorems as arguments.
  4161 
  4162 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4163 jobs to provide advice on the provability of subgoals.
  4164 
  4165 * Theory OrderedGroup and Ring_and_Field: various additions and
  4166 improvements to faciliate calculations involving equalities and
  4167 inequalities.
  4168 
  4169 The following theorems have been eliminated or modified
  4170 (INCOMPATIBILITY):
  4171 
  4172   abs_eq             now named abs_of_nonneg
  4173   abs_of_ge_0        now named abs_of_nonneg
  4174   abs_minus_eq       now named abs_of_nonpos
  4175   imp_abs_id         now named abs_of_nonneg
  4176   imp_abs_neg_id     now named abs_of_nonpos
  4177   mult_pos           now named mult_pos_pos
  4178   mult_pos_le        now named mult_nonneg_nonneg
  4179   mult_pos_neg_le    now named mult_nonneg_nonpos
  4180   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4181   mult_neg           now named mult_neg_neg
  4182   mult_neg_le        now named mult_nonpos_nonpos
  4183 
  4184 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4185      
  4186      zero_le_square
  4187      not_square_less_zero 
  4188 
  4189   The following lemmas have been deleted from Real/RealPow:
  4190   
  4191      realpow_zero_zero
  4192      realpow_two
  4193      realpow_less
  4194      zero_le_power
  4195      realpow_two_le
  4196      abs_realpow_two
  4197      realpow_two_abs     
  4198 
  4199 * Theory Parity: added rules for simplifying exponents.
  4200 
  4201 * Theory List:
  4202 
  4203 The following theorems have been eliminated or modified
  4204 (INCOMPATIBILITY):
  4205 
  4206   list_all_Nil       now named list_all.simps(1)
  4207   list_all_Cons      now named list_all.simps(2)
  4208   list_all_conv      now named list_all_iff
  4209   set_mem_eq         now named mem_iff
  4210 
  4211 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4212 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4213 
  4214 
  4215 *** HOL-Complex ***
  4216 
  4217 * Theory RealDef: better support for embedding natural numbers and
  4218 integers in the reals.
  4219 
  4220 The following theorems have been eliminated or modified
  4221 (INCOMPATIBILITY):
  4222 
  4223   exp_ge_add_one_self  now requires no hypotheses
  4224   real_of_int_add      reversed direction of equality (use [symmetric])
  4225   real_of_int_minus    reversed direction of equality (use [symmetric])
  4226   real_of_int_diff     reversed direction of equality (use [symmetric])
  4227   real_of_int_mult     reversed direction of equality (use [symmetric])
  4228 
  4229 * Theory RComplete: expanded support for floor and ceiling functions.
  4230 
  4231 * Theory Ln is new, with properties of the natural logarithm
  4232 
  4233 * Hyperreal: There is a new type constructor "star" for making
  4234 nonstandard types.  The old type names are now type synonyms:
  4235 
  4236   hypreal = real star
  4237   hypnat = nat star
  4238   hcomplex = complex star
  4239 
  4240 * Hyperreal: Many groups of similarly-defined constants have been
  4241 replaced by polymorphic versions (INCOMPATIBILITY):
  4242 
  4243   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4244 
  4245   starset      <-- starsetNat, starsetC
  4246   *s*          <-- *sNat*, *sc*
  4247   starset_n    <-- starsetNat_n, starsetC_n
  4248   *sn*         <-- *sNatn*, *scn*
  4249   InternalSets <-- InternalNatSets, InternalCSets
  4250 
  4251   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4252   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4253   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4254   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4255   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4256 
  4257 * Hyperreal: Many type-specific theorems have been removed in favor of
  4258 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4259 
  4260   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4261   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4262   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4263   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4264   right_minus <-- hypreal_add_minus
  4265   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4266   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4267   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4268   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4269   mult_1_right <-- hcomplex_mult_one_right
  4270   mult_zero_left <-- hcomplex_mult_zero_left
  4271   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4272   right_distrib <-- hypnat_add_mult_distrib2
  4273   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4274   right_inverse <-- hypreal_mult_inverse
  4275   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4276   order_refl <-- {hypreal,hypnat}_le_refl
  4277   order_trans <-- {hypreal,hypnat}_le_trans
  4278   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4279   order_less_le <-- {hypreal,hypnat}_less_le
  4280   linorder_linear <-- {hypreal,hypnat}_le_linear
  4281   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4282   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4283   add_nonneg_nonneg <-- hypreal_le_add_order
  4284 
  4285 * Hyperreal: Separate theorems having to do with type-specific
  4286 versions of constants have been merged into theorems that apply to the
  4287 new polymorphic constants (INCOMPATIBILITY):
  4288 
  4289   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4290   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4291   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4292   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4293   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4294   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4295   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4296   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4297   STAR_diff <-- {STAR,STARC}_diff
  4298   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4299     STARC_hcomplex_of_complex}_image_subset
  4300   starset_n_Un <-- starset{Nat,C}_n_Un
  4301   starset_n_Int <-- starset{Nat,C}_n_Int
  4302   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4303   starset_n_diff <-- starset{Nat,C}_n_diff
  4304   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4305   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4306   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4307   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4308   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4309   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4310   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4311   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4312   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4313   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4314   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4315   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4316   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4317   starfun_diff <-- starfun{C,RC,CR}_diff
  4318   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4319   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4320   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4321   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4322   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4323   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4324   starfun_Id <-- starfunC_Id
  4325   starfun_approx <-- starfun{Nat,CR}_approx
  4326   starfun_capprox <-- starfun{C,RC}_capprox
  4327   starfun_abs <-- starfunNat_rabs
  4328   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4329   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4330   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4331   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4332   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4333   starfun_add_approx <-- starfunCR_add_approx
  4334   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4335   starfun_divide <-- starfun{C,CR,RC}_divide
  4336   starfun_n <-- starfun{Nat,C}_n
  4337   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4338   starfun_n_add <-- starfun{Nat,C}_n_add
  4339   starfun_n_add_minus <-- starfunNat_n_add_minus
  4340   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4341   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4342   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4343 
  4344   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4345   star_n_minus <-- {hypreal,hcomplex}_minus
  4346   star_n_diff <-- {hypreal,hcomplex}_diff
  4347   star_n_mult <-- {hypreal,hcomplex}_mult
  4348   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4349   star_n_le <-- {hypreal,hypnat}_le
  4350   star_n_less <-- {hypreal,hypnat}_less
  4351   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4352   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4353   star_n_abs <-- hypreal_hrabs
  4354   star_n_divide <-- hcomplex_divide
  4355 
  4356   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4357   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4358   star_of_diff <-- hypreal_of_real_diff
  4359   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4360   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4361   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4362   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4363   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4364   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4365   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4366   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4367   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4368   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4369   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4370   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4371   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4372   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4373   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4374   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4375   star_of_power <-- hypreal_of_real_power
  4376   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4377 
  4378 * Hyperreal: new method "transfer" that implements the transfer
  4379 principle of nonstandard analysis. With a subgoal that mentions
  4380 nonstandard types like "'a star", the command "apply transfer"
  4381 replaces it with an equivalent one that mentions only standard types.
  4382 To be successful, all free variables must have standard types; non-
  4383 standard variables must have explicit universal quantifiers.
  4384 
  4385 * Hyperreal: A theory of Taylor series.
  4386 
  4387 
  4388 *** HOLCF ***
  4389 
  4390 * Discontinued special version of 'constdefs' (which used to support
  4391 continuous functions) in favor of the general Pure one with full
  4392 type-inference.
  4393 
  4394 * New simplification procedure for solving continuity conditions; it
  4395 is much faster on terms with many nested lambda abstractions (cubic
  4396 instead of exponential time).
  4397 
  4398 * New syntax for domain package: selector names are now optional.
  4399 Parentheses should be omitted unless argument is lazy, for example:
  4400 
  4401   domain 'a stream = cons "'a" (lazy "'a stream")
  4402 
  4403 * New command 'fixrec' for defining recursive functions with pattern
  4404 matching; defining multiple functions with mutual recursion is also
  4405 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4406 sinr, or any data constructor defined by the domain package. The given
  4407 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4408 syntax and examples.
  4409 
  4410 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4411 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4412 but the proof obligation additionally includes an admissibility
  4413 requirement. The packages generate instances of class cpo or pcpo,
  4414 with continuity and strictness theorems for Rep and Abs.
  4415 
  4416 * HOLCF: Many theorems have been renamed according to a more standard naming
  4417 scheme (INCOMPATIBILITY):
  4418 
  4419   foo_inject:  "foo$x = foo$y ==> x = y"
  4420   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4421   foo_less:    "(foo$x << foo$y) = (x << y)"
  4422   foo_strict:  "foo$UU = UU"
  4423   foo_defined: "... ==> foo$x ~= UU"
  4424   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4425 
  4426 
  4427 *** ZF ***
  4428 
  4429 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4430 including the First Isomorphism Theorem (on quotienting by the kernel
  4431 of a homomorphism).
  4432 
  4433 * ZF/Simplifier: install second copy of type solver that actually
  4434 makes use of TC rules declared to Isar proof contexts (or locales);
  4435 the old version is still required for ML proof scripts.
  4436 
  4437 
  4438 *** Cube ***
  4439 
  4440 * Converted to Isar theory format; use locales instead of axiomatic
  4441 theories.
  4442 
  4443 
  4444 *** ML ***
  4445 
  4446 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4447 for ||>, ||>>, |>>,
  4448 
  4449 * Pure/library.ML no longer defines its own option datatype, but uses
  4450 that of the SML basis, which has constructors NONE and SOME instead of
  4451 None and Some, as well as exception Option.Option instead of OPTION.
  4452 The functions the, if_none, is_some, is_none have been adapted
  4453 accordingly, while Option.map replaces apsome.
  4454 
  4455 * Pure/library.ML: the exception LIST has been given up in favour of
  4456 the standard exceptions Empty and Subscript, as well as
  4457 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4458 superceded by the standard hd and tl functions etc.
  4459 
  4460 A number of basic list functions are no longer exported to the ML
  4461 toplevel, as they are variants of predefined functions.  The following
  4462 suggests how one can translate existing code:
  4463 
  4464     rev_append xs ys = List.revAppend (xs, ys)
  4465     nth_elem (i, xs) = List.nth (xs, i)
  4466     last_elem xs = List.last xs
  4467     flat xss = List.concat xss
  4468     seq fs = List.app fs
  4469     partition P xs = List.partition P xs
  4470     mapfilter f xs = List.mapPartial f xs
  4471 
  4472 * Pure/library.ML: several combinators for linear functional
  4473 transformations, notably reverse application and composition:
  4474 
  4475   x |> f                f #> g
  4476   (x, y) |-> f          f #-> g
  4477 
  4478 * Pure/library.ML: introduced/changed precedence of infix operators:
  4479 
  4480   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4481   infix 2 ?;
  4482   infix 3 o oo ooo oooo;
  4483   infix 4 ~~ upto downto;
  4484 
  4485 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4486 infix operators.
  4487 
  4488 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4489 fold_map support linear functional transformations and nesting.  For
  4490 example:
  4491 
  4492   fold f [x1, ..., xN] y =
  4493     y |> f x1 |> ... |> f xN
  4494 
  4495   (fold o fold) f [xs1, ..., xsN] y =
  4496     y |> fold f xs1 |> ... |> fold f xsN
  4497 
  4498   fold f [x1, ..., xN] =
  4499     f x1 #> ... #> f xN
  4500 
  4501   (fold o fold) f [xs1, ..., xsN] =
  4502     fold f xs1 #> ... #> fold f xsN
  4503 
  4504 * Pure/library.ML: the following selectors on type 'a option are
  4505 available:
  4506 
  4507   the:               'a option -> 'a  (*partial*)
  4508   these:             'a option -> 'a  where 'a = 'b list
  4509   the_default: 'a -> 'a option -> 'a
  4510   the_list:          'a option -> 'a list
  4511 
  4512 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4513 basic operations for association lists, following natural argument
  4514 order; moreover the explicit equality predicate passed here avoids
  4515 potentially expensive polymorphic runtime equality checks.
  4516 The old functions may be expressed as follows:
  4517 
  4518   assoc = uncurry (AList.lookup (op =))
  4519   assocs = these oo AList.lookup (op =)
  4520   overwrite = uncurry (AList.update (op =)) o swap
  4521 
  4522 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4523 
  4524   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4525   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4526 
  4527 replacing make_keylist and keyfilter (occassionally used)
  4528 Naive rewrites:
  4529 
  4530   make_keylist = AList.make
  4531   keyfilter = AList.find (op =)
  4532 
  4533 * eq_fst and eq_snd now take explicit equality parameter, thus
  4534   avoiding eqtypes. Naive rewrites:
  4535 
  4536     eq_fst = eq_fst (op =)
  4537     eq_snd = eq_snd (op =)
  4538 
  4539 * Removed deprecated apl and apr (rarely used).
  4540   Naive rewrites:
  4541 
  4542     apl (n, op) =>>= curry op n
  4543     apr (op, m) =>>= fn n => op (n, m)
  4544 
  4545 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4546 provides a reasonably efficient light-weight implementation of sets as
  4547 lists.
  4548 
  4549 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4550 few new operations; existing lookup and update are now curried to
  4551 follow natural argument order (for use with fold etc.);
  4552 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4553 
  4554 * Pure/General: output via the Isabelle channels of
  4555 writeln/warning/error etc. is now passed through Output.output, with a
  4556 hook for arbitrary transformations depending on the print_mode
  4557 (cf. Output.add_mode -- the first active mode that provides a output
  4558 function wins).  Already formatted output may be embedded into further
  4559 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4560 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4561 accommodate easy composition of diagnostic messages etc.  Programmers
  4562 rarely need to care about Output.output or Output.raw at all, with
  4563 some notable exceptions: Output.output is required when bypassing the
  4564 standard channels (writeln etc.), or in token translations to produce
  4565 properly formatted results; Output.raw is required when capturing
  4566 already output material that will eventually be presented to the user
  4567 a second time.  For the default print mode, both Output.output and
  4568 Output.raw have no effect.
  4569 
  4570 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4571 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4572 cumulative results are displayed at the end of a batch session.
  4573 
  4574 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4575 replaced by File.platform_path and File.shell_path (with appropriate
  4576 hooks).  This provides a clean interface for unusual systems where the
  4577 internal and external process view of file names are different.
  4578 
  4579 * Pure: more efficient orders for basic syntactic entities: added
  4580 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4581 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4582 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4583 orders now -- potential INCOMPATIBILITY for code that depends on a
  4584 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4585 Library.sort_strings on result).
  4586 
  4587 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4588 fold_types traverse types/terms from left to right, observing natural
  4589 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4590 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4591 
  4592 * Pure: name spaces have been refined, with significant changes of the
  4593 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4594 to extern(_table).  The plain name entry path is superceded by a
  4595 general 'naming' context, which also includes the 'policy' to produce
  4596 a fully qualified name and external accesses of a fully qualified
  4597 name; NameSpace.extend is superceded by context dependent
  4598 Sign.declare_name.  Several theory and proof context operations modify
  4599 the naming context.  Especially note Theory.restore_naming and
  4600 ProofContext.restore_naming to get back to a sane state; note that
  4601 Theory.add_path is no longer sufficient to recover from
  4602 Theory.absolute_path in particular.
  4603 
  4604 * Pure: new flags short_names (default false) and unique_names
  4605 (default true) for controlling output of qualified names.  If
  4606 short_names is set, names are printed unqualified.  If unique_names is
  4607 reset, the name prefix is reduced to the minimum required to achieve
  4608 the original result when interning again, even if there is an overlap
  4609 with earlier declarations.
  4610 
  4611 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4612 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4613 (useful for printing error messages).  INCOMPATIBILITY.
  4614 
  4615 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4616 Theory.theory are now identified, referring to the universal
  4617 Context.theory (see Pure/context.ML).  Actual signature and theory
  4618 content is managed as theory data.  The old code and interfaces were
  4619 spread over many files and structures; the new arrangement introduces
  4620 considerable INCOMPATIBILITY to gain more clarity:
  4621 
  4622   Context -- theory management operations (name, identity, inclusion,
  4623     parents, ancestors, merge, etc.), plus generic theory data;
  4624 
  4625   Sign -- logical signature and syntax operations (declaring consts,
  4626     types, etc.), plus certify/read for common entities;
  4627 
  4628   Theory -- logical theory operations (stating axioms, definitions,
  4629     oracles), plus a copy of logical signature operations (consts,
  4630     types, etc.); also a few basic management operations (Theory.copy,
  4631     Theory.merge, etc.)
  4632 
  4633 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4634 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4635 for convenience -- they merely return the theory.
  4636 
  4637 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4638 
  4639 * Pure: the Isar proof context type is already defined early in Pure
  4640 as Context.proof (note that ProofContext.context and Proof.context are
  4641 aliases, where the latter is the preferred name).  This enables other
  4642 Isabelle components to refer to that type even before Isar is present.
  4643 
  4644 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4645 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4646 any of these kinds.  For example, Sign.intern typeK is now
  4647 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4648 Theory.hide_types.  Also note that former
  4649 Theory.hide_classes/types/consts are now
  4650 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4651 internalize their arguments!  INCOMPATIBILITY.
  4652 
  4653 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4654 datatype thmref (with constructors Name and NameSelection) instead of
  4655 plain string -- INCOMPATIBILITY;
  4656 
  4657 * Pure: cases produced by proof methods specify options, where NONE
  4658 means to remove case bindings -- INCOMPATIBILITY in
  4659 (RAW_)METHOD_CASES.
  4660 
  4661 * Pure: the following operations retrieve axioms or theorems from a
  4662 theory node or theory hierarchy, respectively:
  4663 
  4664   Theory.axioms_of: theory -> (string * term) list
  4665   Theory.all_axioms_of: theory -> (string * term) list
  4666   PureThy.thms_of: theory -> (string * thm) list
  4667   PureThy.all_thms_of: theory -> (string * thm) list
  4668 
  4669 * Pure: print_tac now outputs the goal through the trace channel.
  4670 
  4671 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4672 Reference Toplevel.debug (default false) controls detailed printing
  4673 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4674 controls execution profiling -- set to 1 for time and 2 for space
  4675 (both increase the runtime).
  4676 
  4677 * Isar session: The initial use of ROOT.ML is now always timed,
  4678 i.e. the log will show the actual process times, in contrast to the
  4679 elapsed wall-clock time that the outer shell wrapper produces.
  4680 
  4681 * Simplifier: improved handling of bound variables (nameless
  4682 representation, avoid allocating new strings).  Simprocs that invoke
  4683 the Simplifier recursively should use Simplifier.inherit_bounds to
  4684 avoid local name clashes.  Failure to do so produces warnings
  4685 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4686 for further details.
  4687 
  4688 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4689 bindings for all theorems stored within a given theory; this may help
  4690 in porting non-Isar theories to Isar ones, while keeping ML proof
  4691 scripts for the time being.
  4692 
  4693 * ML operator HTML.with_charset specifies the charset begin used for
  4694 generated HTML files.  For example:
  4695 
  4696   HTML.with_charset "utf-8" use_thy "Hebrew";
  4697   HTML.with_charset "utf-8" use_thy "Chinese";
  4698 
  4699 
  4700 *** System ***
  4701 
  4702 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4703 isabelle, isatool etc.).
  4704 
  4705 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4706 isatool doc, isatool mkdir, display_drafts etc.).
  4707 
  4708 * isatool usedir: option -f allows specification of the ML file to be
  4709 used by Isabelle; default is ROOT.ML.
  4710 
  4711 * New isatool version outputs the version identifier of the Isabelle
  4712 distribution being used.
  4713 
  4714 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4715 (containing Boolean satisfiability problems) into Isabelle/HOL
  4716 theories.
  4717 
  4718 
  4719 
  4720 New in Isabelle2004 (April 2004)
  4721 --------------------------------
  4722 
  4723 *** General ***
  4724 
  4725 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4726   Replaces linorder.ML.
  4727 
  4728 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4729   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4730   (\<a>...\<z>), are now considered normal letters, and can therefore
  4731   be used anywhere where an ASCII letter (a...zA...Z) has until
  4732   now. COMPATIBILITY: This obviously changes the parsing of some
  4733   terms, especially where a symbol has been used as a binder, say
  4734   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4735   as an identifier.  Fix it by inserting a space around former
  4736   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4737   existing theory and ML files.
  4738 
  4739 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4740 
  4741 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4742   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4743   a normal (but invisible) letter. For multiple letter subscripts repeat
  4744   \<^isub> like this: x\<^isub>1\<^isub>2.
  4745 
  4746 * Pure: There are now sub-/superscripts that can span more than one
  4747   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4748   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4749   superscript. The new control characters are not identifier parts.
  4750 
  4751 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4752   content of "..." to the latex file instead of \isacntrl... . The "..."
  4753   may consist of any printable characters excluding the end bracket >.
  4754 
  4755 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4756   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4757   declare constants "final", which prevents their being given a definition
  4758   later.  It is useful for constants whose behaviour is fixed axiomatically
  4759   rather than definitionally, such as the meta-logic connectives.
  4760 
  4761 * Pure: 'instance' now handles general arities with general sorts
  4762   (i.e. intersections of classes),
  4763 
  4764 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4765   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4766   It can be changed to alter the colors/layout of generated pages.
  4767 
  4768 
  4769 *** Isar ***
  4770 
  4771 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4772   cut_tac, subgoal_tac and thin_tac:
  4773   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4774     locales are no longer forced to write Isar proof scripts.
  4775     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4776     emulations.
  4777   - INCOMPATIBILITY: names of variables to be instantiated may no
  4778     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4779     This is consistent with the instantiation attribute "where".
  4780 
  4781 * Attributes "where" and "of":
  4782   - Now take type variables of instantiated theorem into account when reading
  4783     the instantiation string.  This fixes a bug that caused instantiated
  4784     theorems to have too special types in some circumstances.
  4785   - "where" permits explicit instantiations of type variables.
  4786 
  4787 * Calculation commands "moreover" and "also" no longer interfere with
  4788   current facts ("this"), admitting arbitrary combinations with "then"
  4789   and derived forms.
  4790 
  4791 * Locales:
  4792   - Goal statements involving the context element "includes" no longer
  4793     generate theorems with internal delta predicates (those ending on
  4794     "_axioms") in the premise.
  4795     Resolve particular premise with <locale>.intro to obtain old form.
  4796   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4797     specification and "includes" elements in goal statement.
  4798   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4799     [intro?] and [elim?] (respectively) by default.
  4800   - Experimental command for instantiation of locales in proof contexts:
  4801         instantiate <label>[<attrs>]: <loc>
  4802     Instantiates locale <loc> and adds all its theorems to the current context
  4803     taking into account their attributes.  Label and attrs are optional
  4804     modifiers, like in theorem declarations.  If present, names of
  4805     instantiated theorems are qualified with <label>, and the attributes
  4806     <attrs> are applied after any attributes these theorems might have already.
  4807       If the locale has assumptions, a chained fact of the form
  4808     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4809     are derived.  The command does not support old-style locales declared
  4810     with "locale (open)".
  4811       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4812 
  4813 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4814   (Isar) contexts.
  4815 
  4816 
  4817 *** HOL ***
  4818 
  4819 * Proof import: new image HOL4 contains the imported library from
  4820   the HOL4 system with about 2500 theorems. It is imported by
  4821   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4822   can be used like any other Isabelle image.  See
  4823   HOL/Import/HOL/README for more information.
  4824 
  4825 * Simplifier:
  4826   - Much improved handling of linear and partial orders.
  4827     Reasoners for linear and partial orders are set up for type classes
  4828     "linorder" and "order" respectively, and are added to the default simpset
  4829     as solvers.  This means that the simplifier can build transitivity chains
  4830     to solve goals from the assumptions.
  4831   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4832     of blast or auto after simplification become unnecessary because the goal
  4833     is solved by simplification already.
  4834 
  4835 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4836     all proved in axiomatic type classes for semirings, rings and fields.
  4837 
  4838 * Numerics:
  4839   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4840     now formalized using the Ring_and_Field theory mentioned above.
  4841   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4842     than before, because now they are set up once in a generic manner.
  4843   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4844     Look for the general versions in Ring_and_Field (and Power if they concern
  4845     exponentiation).
  4846 
  4847 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4848 
  4849 * Records:
  4850   - Record types are now by default printed with their type abbreviation
  4851     instead of the list of all field types. This can be configured via
  4852     the reference "print_record_type_abbr".
  4853   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4854     (not enabled by default).
  4855   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4856     EX x. x = sel r to True (not enabled by default).
  4857   - Tactic "record_split_simp_tac" to split and simplify records added.
  4858 
  4859 * 'specification' command added, allowing for definition by
  4860   specification.  There is also an 'ax_specification' command that
  4861   introduces the new constants axiomatically.
  4862 
  4863 * arith(_tac) is now able to generate counterexamples for reals as well.
  4864 
  4865 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4866 
  4867 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4868   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4869 
  4870 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4871   matrix theory to linear programming.
  4872 
  4873 * Unions and Intersections:
  4874   The latex output syntax of UN and INT has been changed
  4875   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4876   i.e. the index formulae has become a subscript.
  4877   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4878 
  4879 * Unions and Intersections over Intervals:
  4880   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4881   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4882   like in normal math, and corresponding versions for < and for intersection.
  4883 
  4884 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4885   lexicographic dictonary ordering has been added as "lexord".
  4886 
  4887 * ML: the legacy theory structures Int and List have been removed. They had
  4888   conflicted with ML Basis Library structures having the same names.
  4889 
  4890 * 'refute' command added to search for (finite) countermodels.  Only works
  4891   for a fragment of HOL.  The installation of an external SAT solver is
  4892   highly recommended.  See "HOL/Refute.thy" for details.
  4893 
  4894 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4895   formulae under an assignment of free variables to random values.
  4896   In contrast to 'refute', it can deal with inductive datatypes,
  4897   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4898   for examples.
  4899 
  4900 
  4901 *** HOLCF ***
  4902 
  4903 * Streams now come with concatenation and are part of the HOLCF image
  4904 
  4905 
  4906 
  4907 New in Isabelle2003 (May 2003)
  4908 ------------------------------
  4909 
  4910 *** General ***
  4911 
  4912 * Provers/simplifier:
  4913 
  4914   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4915     Assumptions are now subject to complete mutual simplification,
  4916     not just from left to right. The simplifier now preserves
  4917     the order of assumptions.
  4918 
  4919     Potential INCOMPATIBILITY:
  4920 
  4921     -- simp sometimes diverges where the old version did
  4922        not, e.g. invoking simp on the goal
  4923 
  4924         [| P (f x); y = x; f x = f y |] ==> Q
  4925 
  4926        now gives rise to the infinite reduction sequence
  4927 
  4928         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4929 
  4930        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4931        kind of problem.
  4932 
  4933     -- Tactics combining classical reasoner and simplification (such as auto)
  4934        are also affected by this change, because many of them rely on
  4935        simp. They may sometimes diverge as well or yield a different numbers
  4936        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4937        in case of problems. Sometimes subsequent calls to the classical
  4938        reasoner will fail because a preceeding call to the simplifier too
  4939        eagerly simplified the goal, e.g. deleted redundant premises.
  4940 
  4941   - The simplifier trace now shows the names of the applied rewrite rules
  4942 
  4943   - You can limit the number of recursive invocations of the simplifier
  4944     during conditional rewriting (where the simplifie tries to solve the
  4945     conditions before applying the rewrite rule):
  4946     ML "simp_depth_limit := n"
  4947     where n is an integer. Thus you can force termination where previously
  4948     the simplifier would diverge.
  4949 
  4950   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4951 
  4952   - No longer aborts on failed congruence proof.  Instead, the
  4953     congruence is ignored.
  4954 
  4955 * Pure: New generic framework for extracting programs from constructive
  4956   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4957   as HOL/Extraction for some case studies.
  4958 
  4959 * Pure: The main goal of the proof state is no longer shown by default, only
  4960 the subgoals. This behaviour is controlled by a new flag.
  4961    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4962 (ML: Proof.show_main_goal).
  4963 
  4964 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4965 rules whose conclusion matches subgoal 1:
  4966       PG menu: Isabelle/Isar -> Show me -> matching rules
  4967 The rules are ordered by how closely they match the subgoal.
  4968 In particular, rules that solve a subgoal outright are displayed first
  4969 (or rather last, the way they are printed).
  4970 (ML: ProofGeneral.print_intros())
  4971 
  4972 * Pure: New flag trace_unify_fail causes unification to print
  4973 diagnostic information (PG: in trace buffer) when it fails. This is
  4974 useful for figuring out why single step proofs like rule, erule or
  4975 assumption failed.
  4976 
  4977 * Pure: Locale specifications now produce predicate definitions
  4978 according to the body of text (covering assumptions modulo local
  4979 definitions); predicate "loc_axioms" covers newly introduced text,
  4980 while "loc" is cumulative wrt. all included locale expressions; the
  4981 latter view is presented only on export into the global theory
  4982 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4983 on the old view without predicates;
  4984 
  4985 * Pure: predefined locales "var" and "struct" are useful for sharing
  4986 parameters (as in CASL, for example); just specify something like
  4987 ``var x + var y + struct M'' as import;
  4988 
  4989 * Pure: improved thms_containing: proper indexing of facts instead of
  4990 raw theorems; check validity of results wrt. current name space;
  4991 include local facts of proof configuration (also covers active
  4992 locales), cover fixed variables in index; may use "_" in term
  4993 specification; an optional limit for the number of printed facts may
  4994 be given (the default is 40);
  4995 
  4996 * Pure: disallow duplicate fact bindings within new-style theory files
  4997 (batch-mode only);
  4998 
  4999 * Provers: improved induct method: assumptions introduced by case
  5000 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5001 the goal statement); "foo" still refers to all facts collectively;
  5002 
  5003 * Provers: the function blast.overloaded has been removed: all constants
  5004 are regarded as potentially overloaded, which improves robustness in exchange
  5005 for slight decrease in efficiency;
  5006 
  5007 * Provers/linorder: New generic prover for transitivity reasoning over
  5008 linear orders.  Note: this prover is not efficient!
  5009 
  5010 * Isar: preview of problems to finish 'show' now produce an error
  5011 rather than just a warning (in interactive mode);
  5012 
  5013 
  5014 *** HOL ***
  5015 
  5016 * arith(_tac)
  5017 
  5018  - Produces a counter example if it cannot prove a goal.
  5019    Note that the counter example may be spurious if the goal is not a formula
  5020    of quantifier-free linear arithmetic.
  5021    In ProofGeneral the counter example appears in the trace buffer.
  5022 
  5023  - Knows about div k and mod k where k is a numeral of type nat or int.
  5024 
  5025  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5026    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5027    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5028 
  5029 * simp's arithmetic capabilities have been enhanced a bit: it now
  5030 takes ~= in premises into account (by performing a case split);
  5031 
  5032 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5033 are distributed over a sum of terms;
  5034 
  5035 * New tactic "trans_tac" and method "trans" instantiate
  5036 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5037 "<=", "<" and "=").
  5038 
  5039 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5040 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5041 
  5042 * 'typedef' command has new option "open" to suppress the set
  5043 definition;
  5044 
  5045 * functions Min and Max on finite sets have been introduced (theory
  5046 Finite_Set);
  5047 
  5048 * attribute [symmetric] now works for relations as well; it turns
  5049 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5050 
  5051 * induct over a !!-quantified statement (say !!x1..xn):
  5052   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5053 
  5054 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5055 %x. None. Warning: empty_def now refers to the previously hidden definition
  5056 of the empty set.
  5057 
  5058 * Algebra: formalization of classical algebra.  Intended as base for
  5059 any algebraic development in Isabelle.  Currently covers group theory
  5060 (up to Sylow's theorem) and ring theory (Universal Property of
  5061 Univariate Polynomials).  Contributions welcome;
  5062 
  5063 * GroupTheory: deleted, since its material has been moved to Algebra;
  5064 
  5065 * Complex: new directory of the complex numbers with numeric constants,
  5066 nonstandard complex numbers, and some complex analysis, standard and
  5067 nonstandard (Jacques Fleuriot);
  5068 
  5069 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5070 
  5071 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5072 Fleuriot);
  5073 
  5074 * Real/HahnBanach: updated and adapted to locales;
  5075 
  5076 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5077 Gray and Kramer);
  5078 
  5079 * UNITY: added the Meier-Sanders theory of progress sets;
  5080 
  5081 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5082 as abstract algorithms, instantiated to the JVM;
  5083 
  5084 * Bali: Java source language formalization. Type system, operational
  5085 semantics, axiomatic semantics. Supported language features:
  5086 classes, interfaces, objects,virtual methods, static methods,
  5087 static/instance fields, arrays, access modifiers, definite
  5088 assignment, exceptions.
  5089 
  5090 
  5091 *** ZF ***
  5092 
  5093 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5094 universe, etc.);
  5095 
  5096 * Main ZF: virtually all theories converted to new-style format;
  5097 
  5098 
  5099 *** ML ***
  5100 
  5101 * Pure: Tactic.prove provides sane interface for internal proofs;
  5102 omits the infamous "standard" operation, so this is more appropriate
  5103 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5104 
  5105 * Pure: improved error reporting of simprocs;
  5106 
  5107 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5108 up simprocs;
  5109 
  5110 
  5111 *** Document preparation ***
  5112 
  5113 * uses \par instead of \\ for line breaks in theory text. This may
  5114 shift some page breaks in large documents. To get the old behaviour
  5115 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5116 
  5117 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5118 other packages
  5119 
  5120 * \<euro> now needs package babel/greek instead of marvosym (which
  5121 broke \Rightarrow)
  5122 
  5123 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5124 textcomp package)
  5125 
  5126 
  5127 
  5128 New in Isabelle2002 (March 2002)
  5129 --------------------------------
  5130 
  5131 *** Document preparation ***
  5132 
  5133 * greatly simplified document preparation setup, including more
  5134 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5135 instructive isatool mkdir; users should basically be able to get
  5136 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5137 users may run a separate document processing stage manually like this:
  5138 "isatool usedir -D output HOL Test && isatool document Test/output";
  5139 
  5140 * theory dependency graph may now be incorporated into documents;
  5141 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5142 with \includegraphics of LaTeX;
  5143 
  5144 * proper spacing of consecutive markup elements, especially text
  5145 blocks after section headings;
  5146 
  5147 * support bold style (for single symbols only), input syntax is like
  5148 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5149 
  5150 * \<bullet> is now output as bold \cdot by default, which looks much
  5151 better in printed text;
  5152 
  5153 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5154 note that these symbols are currently unavailable in Proof General /
  5155 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5156 
  5157 * isatool latex no longer depends on changed TEXINPUTS, instead
  5158 isatool document copies the Isabelle style files to the target
  5159 location;
  5160 
  5161 
  5162 *** Isar ***
  5163 
  5164 * Pure/Provers: improved proof by cases and induction;
  5165   - 'case' command admits impromptu naming of parameters (such as
  5166     "case (Suc n)");
  5167   - 'induct' method divinates rule instantiation from the inductive
  5168     claim; no longer requires excessive ?P bindings for proper
  5169     instantiation of cases;
  5170   - 'induct' method properly enumerates all possibilities of set/type
  5171     rules; as a consequence facts may be also passed through *type*
  5172     rules without further ado;
  5173   - 'induct' method now derives symbolic cases from the *rulified*
  5174     rule (before it used to rulify cases stemming from the internal
  5175     atomized version); this means that the context of a non-atomic
  5176     statement becomes is included in the hypothesis, avoiding the
  5177     slightly cumbersome show "PROP ?case" form;
  5178   - 'induct' may now use elim-style induction rules without chaining
  5179     facts, using ``missing'' premises from the goal state; this allows
  5180     rules stemming from inductive sets to be applied in unstructured
  5181     scripts, while still benefitting from proper handling of non-atomic
  5182     statements; NB: major inductive premises need to be put first, all
  5183     the rest of the goal is passed through the induction;
  5184   - 'induct' proper support for mutual induction involving non-atomic
  5185     rule statements (uses the new concept of simultaneous goals, see
  5186     below);
  5187   - append all possible rule selections, but only use the first
  5188     success (no backtracking);
  5189   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5190   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5191   - added 'print_induct_rules' (covered by help item in recent Proof
  5192     General versions);
  5193   - moved induct/cases attributes to Pure, methods to Provers;
  5194   - generic method setup instantiated for FOL and HOL;
  5195 
  5196 * Pure: support multiple simultaneous goal statements, for example
  5197 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5198 meta-level mechanism, this acts as if several individual goals had
  5199 been stated separately; in particular common proof methods need to be
  5200 repeated in order to cover all claims; note that a single elimination
  5201 step is *not* sufficient to establish the two conjunctions, so this
  5202 fails:
  5203 
  5204   assume "A & B" then have A and B ..   (*".." fails*)
  5205 
  5206 better use "obtain" in situations as above; alternative refer to
  5207 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5208 
  5209 * Pure: proper integration with ``locales''; unlike the original
  5210 version by Florian Kammller, Isar locales package high-level proof
  5211 contexts rather than raw logical ones (e.g. we admit to include
  5212 attributes everywhere); operations on locales include merge and
  5213 rename; support for implicit arguments (``structures''); simultaneous
  5214 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5215 some examples;
  5216 
  5217 * Pure: the following commands have been ``localized'', supporting a
  5218 target locale specification "(in name)": 'lemma', 'theorem',
  5219 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5220 stored both within the locale and at the theory level (exported and
  5221 qualified by the locale name);
  5222 
  5223 * Pure: theory goals may now be specified in ``long'' form, with
  5224 ad-hoc contexts consisting of arbitrary locale elements. for example
  5225 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5226 definitions may be given, too); the result is a meta-level rule with
  5227 the context elements being discharged in the obvious way;
  5228 
  5229 * Pure: new proof command 'using' allows to augment currently used
  5230 facts after a goal statement ('using' is syntactically analogous to
  5231 'apply', but acts on the goal's facts only); this allows chained facts
  5232 to be separated into parts given before and after a claim, as in
  5233 ``from a and b have C using d and e <proof>'';
  5234 
  5235 * Pure: renamed "antecedent" case to "rule_context";
  5236 
  5237 * Pure: new 'judgment' command records explicit information about the
  5238 object-logic embedding (used by several tools internally); no longer
  5239 use hard-wired "Trueprop";
  5240 
  5241 * Pure: added 'corollary' command;
  5242 
  5243 * Pure: fixed 'token_translation' command;
  5244 
  5245 * Pure: removed obsolete 'exported' attribute;
  5246 
  5247 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5248 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5249 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5250 
  5251 * Pure: method 'atomize' presents local goal premises as object-level
  5252 statements (atomic meta-level propositions); setup controlled via
  5253 rewrite rules declarations of 'atomize' attribute; example
  5254 application: 'induct' method with proper rule statements in improper
  5255 proof *scripts*;
  5256 
  5257 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5258 now consider the syntactic context of assumptions, giving a better
  5259 chance to get type-inference of the arguments right (this is
  5260 especially important for locales);
  5261 
  5262 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5263 mode;
  5264 
  5265 * Pure/obtain: the formal conclusion "thesis", being marked as
  5266 ``internal'', may no longer be reference directly in the text;
  5267 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5268 situations;
  5269 
  5270 * Pure: generic 'sym' attribute which declares a rule both as pure
  5271 'elim?' and for the 'symmetric' operation;
  5272 
  5273 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5274 text; the fixed correlation with particular command syntax has been
  5275 discontinued;
  5276 
  5277 * Pure: new method 'rules' is particularly well-suited for proof
  5278 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5279 but often produces more compact proof terms with less detours;
  5280 
  5281 * Pure/Provers/classical: simplified integration with pure rule
  5282 attributes and methods; the classical "intro?/elim?/dest?"
  5283 declarations coincide with the pure ones; the "rule" method no longer
  5284 includes classically swapped intros; "intro" and "elim" methods no
  5285 longer pick rules from the context; also got rid of ML declarations
  5286 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5287 INCOMPATIBILITY;
  5288 
  5289 * Provers/classical: attribute 'swapped' produces classical inversions
  5290 of introduction rules;
  5291 
  5292 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5293 rules instead of full simplifier context; 'iff' attribute handles
  5294 conditional rules;
  5295 
  5296 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5297 
  5298 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5299 "(permissive)" option to recover old behavior;
  5300 
  5301 * HOL: 'inductive' no longer features separate (collective) attributes
  5302 for 'intros' (was found too confusing);
  5303 
  5304 * HOL: properly declared induction rules less_induct and
  5305 wf_induct_rule;
  5306 
  5307 
  5308 *** HOL ***
  5309 
  5310 * HOL: moved over to sane numeral syntax; the new policy is as
  5311 follows:
  5312 
  5313   - 0 and 1 are polymorphic constants, which are defined on any
  5314   numeric type (nat, int, real etc.);
  5315 
  5316   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5317   binary representation internally;
  5318 
  5319   - type nat has special constructor Suc, and generally prefers Suc 0
  5320   over 1::nat and Suc (Suc 0) over 2::nat;
  5321 
  5322 This change may cause significant problems of INCOMPATIBILITY; here
  5323 are some hints on converting existing sources:
  5324 
  5325   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5326   entities, so expressions involving "-" (unary or binary minus) need
  5327   to be spaced properly;
  5328 
  5329   - existing occurrences of "1" may need to be constraint "1::nat" or
  5330   even replaced by Suc 0; similar for old "2";
  5331 
  5332   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5333 
  5334   - remove all special provisions on numerals in proofs;
  5335 
  5336 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5337 representation (depends on bin_arith_simps in the default context);
  5338 
  5339 * HOL: symbolic syntax for x^2 (numeral 2);
  5340 
  5341 * HOL: the class of all HOL types is now called "type" rather than
  5342 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5343 in axclass/classes, instance/arities, and (usually rare) occurrences
  5344 in typings (of consts etc.); internally the class is called
  5345 "HOL.type", ML programs should refer to HOLogic.typeS;
  5346 
  5347 * HOL/record package improvements:
  5348   - new derived operations "fields" to build a partial record section,
  5349     "extend" to promote a fixed record to a record scheme, and
  5350     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5351     declared as simp by default;
  5352   - shared operations ("more", "fields", etc.) now need to be always
  5353     qualified) --- potential INCOMPATIBILITY;
  5354   - removed "make_scheme" operations (use "make" with "extend") --
  5355     INCOMPATIBILITY;
  5356   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5357   - provides cases/induct rules for use with corresponding Isar
  5358     methods (for concrete records, record schemes, concrete more
  5359     parts, and schematic more parts -- in that order);
  5360   - internal definitions directly based on a light-weight abstract
  5361     theory of product types over typedef rather than datatype;
  5362 
  5363 * HOL: generic code generator for generating executable ML code from
  5364 specifications; specific support for HOL constructs such as inductive
  5365 datatypes and sets, as well as recursive functions; can be invoked
  5366 via 'generate_code' theory section;
  5367 
  5368 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5369 
  5370 * HOL: consolidated and renamed several theories.  In particular:
  5371         Ord.thy has been absorbed into HOL.thy
  5372         String.thy has been absorbed into List.thy
  5373 
  5374 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5375 (beware of argument permutation!);
  5376 
  5377 * HOL: linorder_less_split superseded by linorder_cases;
  5378 
  5379 * HOL/List: "nodups" renamed to "distinct";
  5380 
  5381 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5382 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5383   - Ex_def has changed, now need to use some_eq_ex
  5384 
  5385 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5386 in this (rare) case use:
  5387 
  5388   delSWrapper "split_all_tac"
  5389   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5390 
  5391 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5392 MAY FAIL;
  5393 
  5394 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5395 Isabelle's type classes, ^ on functions and relations has too general
  5396 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5397 necessary to attach explicit type constraints;
  5398 
  5399 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5400 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5401 renamed accordingly (eg "compI" -> "rel_compI").
  5402 
  5403 * HOL: syntax translations now work properly with numerals and records
  5404 expressions;
  5405 
  5406 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5407 of "lam" -- INCOMPATIBILITY;
  5408 
  5409 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5410 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5411 renamed "Product_Type.unit";
  5412 
  5413 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5414 
  5415 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5416 the "cases" method);
  5417 
  5418 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5419 Florian Kammller);
  5420 
  5421 * HOL/IMP: updated and converted to new-style theory format; several
  5422 parts turned into readable document, with proper Isar proof texts and
  5423 some explanations (by Gerwin Klein);
  5424 
  5425 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5426 
  5427 * HOL-Hyperreal is now a logic image;
  5428 
  5429 
  5430 *** HOLCF ***
  5431 
  5432 * Isar: consts/constdefs supports mixfix syntax for continuous
  5433 operations;
  5434 
  5435 * Isar: domain package adapted to new-style theory format, e.g. see
  5436 HOLCF/ex/Dnat.thy;
  5437 
  5438 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5439 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5440 lift.induct_tac, always use UU instead of Undef;
  5441 
  5442 * HOLCF/IMP: updated and converted to new-style theory;
  5443 
  5444 
  5445 *** ZF ***
  5446 
  5447 * Isar: proper integration of logic-specific tools and packages,
  5448 including theory commands '(co)inductive', '(co)datatype',
  5449 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5450 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5451 
  5452 * theory Main no longer includes AC; for the Axiom of Choice, base
  5453 your theory on Main_ZFC;
  5454 
  5455 * the integer library now covers quotients and remainders, with many
  5456 laws relating division to addition, multiplication, etc.;
  5457 
  5458 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5459 typeless version of the formalism;
  5460 
  5461 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5462 format;
  5463 
  5464 * ZF/Induct: new directory for examples of inductive definitions,
  5465 including theory Multiset for multiset orderings; converted to
  5466 new-style theory format;
  5467 
  5468 * ZF: many new theorems about lists, ordinals, etc.;
  5469 
  5470 
  5471 *** General ***
  5472 
  5473 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5474 variable proof controls level of detail: 0 = no proofs (only oracle
  5475 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5476 also ref manual for further ML interfaces;
  5477 
  5478 * Pure/axclass: removed obsolete ML interface
  5479 goal_subclass/goal_arity;
  5480 
  5481 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5482 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5483 separate tokens, so expressions involving minus need to be spaced
  5484 properly;
  5485 
  5486 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5487 rather than "infixl" or "infixr";
  5488 
  5489 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5490 sort constraint specifications in type inference; e.g. "x::_::foo"
  5491 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5492 type variable);
  5493 
  5494 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5495 control output of nested => (types); the default behavior is
  5496 "type_brackets";
  5497 
  5498 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5499 tokens into AST constants;
  5500 
  5501 * Pure/syntax: prefer later declarations of translations and print
  5502 translation functions; potential INCOMPATIBILITY: need to reverse
  5503 multiple declarations for same syntax element constant;
  5504 
  5505 * Pure/show_hyps reset by default (in accordance to existing Isar
  5506 practice);
  5507 
  5508 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5509 addSafter;
  5510 
  5511 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5512 as well;
  5513 
  5514 * system: tested support for MacOS X; should be able to get Isabelle +
  5515 Proof General to work in a plain Terminal after installing Poly/ML
  5516 (e.g. from the Isabelle distribution area) and GNU bash alone
  5517 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5518 support requires further installations, e.g. from
  5519 http://fink.sourceforge.net/);
  5520 
  5521 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5522 
  5523 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5524 of 40 MB), cf. ML_OPTIONS;
  5525 
  5526 * system: Proof General keywords specification is now part of the
  5527 Isabelle distribution (see etc/isar-keywords.el);
  5528 
  5529 * system: support for persistent Proof General sessions (refrain from
  5530 outdating all loaded theories on startup); user may create writable
  5531 logic images like this: ``isabelle -q HOL Test'';
  5532 
  5533 * system: smart selection of Isabelle process versus Isabelle
  5534 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5535 run both "isabelle" and "Isabelle" even if file names are badly
  5536 damaged (executable inspects the case of the first letter of its own
  5537 name); added separate "isabelle-process" and "isabelle-interface";
  5538 
  5539 * system: refrain from any attempt at filtering input streams; no
  5540 longer support ``8bit'' encoding of old isabelle font, instead proper
  5541 iso-latin characters may now be used; the related isatools
  5542 "symbolinput" and "nonascii" have disappeared as well;
  5543 
  5544 * system: removed old "xterm" interface (the print modes "xterm" and
  5545 "xterm_color" are still available for direct use in a suitable
  5546 terminal);
  5547 
  5548 
  5549 
  5550 New in Isabelle99-2 (February 2001)
  5551 -----------------------------------
  5552 
  5553 *** Overview of INCOMPATIBILITIES ***
  5554 
  5555 * HOL: please note that theories in the Library and elsewhere often use the
  5556 new-style (Isar) format; to refer to their theorems in an ML script you must
  5557 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5558 
  5559 * HOL: inductive package no longer splits induction rule aggressively,
  5560 but only as far as specified by the introductions given; the old
  5561 format may be recovered via ML function complete_split_rule or attribute
  5562 'split_rule (complete)';
  5563 
  5564 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5565 gfp_Tarski to gfp_unfold;
  5566 
  5567 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5568 
  5569 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5570 relation); infix "^^" has been renamed "``"; infix "``" has been
  5571 renamed "`"; "univalent" has been renamed "single_valued";
  5572 
  5573 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5574 operation;
  5575 
  5576 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5577 
  5578 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5579 
  5580 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5581 consequence, it is no longer monotonic wrt. the local goal context
  5582 (which is now passed through the inductive cases);
  5583 
  5584 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5585 \<gg> to \<ggreater>;
  5586 
  5587 
  5588 *** Document preparation ***
  5589 
  5590 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5591 available: are "it" for near math-mode best-style output, "sl" for
  5592 slanted text style, and "tt" for plain type-writer; if no
  5593 \isabellestyle command is given, output is according to slanted
  5594 type-writer);
  5595 
  5596 * support sub/super scripts (for single symbols only), input syntax is
  5597 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5598 
  5599 * some more standard symbols; see Appendix A of the system manual for
  5600 the complete list of symbols defined in isabellesym.sty;
  5601 
  5602 * improved isabelle style files; more abstract symbol implementation
  5603 (should now use \isamath{...} and \isatext{...} in custom symbol
  5604 definitions);
  5605 
  5606 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5607 state; Note that presentation of goal states does not conform to
  5608 actual human-readable proof documents.  Please do not include goal
  5609 states into document output unless you really know what you are doing!
  5610 
  5611 * proper indentation of antiquoted output with proportional LaTeX
  5612 fonts;
  5613 
  5614 * no_document ML operator temporarily disables LaTeX document
  5615 generation;
  5616 
  5617 * isatool unsymbolize tunes sources for plain ASCII communication;
  5618 
  5619 
  5620 *** Isar ***
  5621 
  5622 * Pure: Isar now suffers initial goal statements to contain unbound
  5623 schematic variables (this does not conform to actual readable proof
  5624 documents, due to unpredictable outcome and non-compositional proof
  5625 checking); users who know what they are doing may use schematic goals
  5626 for Prolog-style synthesis of proven results;
  5627 
  5628 * Pure: assumption method (an implicit finishing) now handles actual
  5629 rules as well;
  5630 
  5631 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5632 initial goal, declare "that" only as Pure intro (only for single
  5633 steps); the "that" rule assumption may now be involved in implicit
  5634 finishing, thus ".." becomes a feasible for trivial obtains;
  5635 
  5636 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5637 instance proofs may be performed by "..";
  5638 
  5639 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5640 statements as well;
  5641 
  5642 * Pure: more robust selection of calculational rules;
  5643 
  5644 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5645 rule (as well as the assumption rule);
  5646 
  5647 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5648 lemmas, using the graph browser tool;
  5649 
  5650 * Pure: predict failure of "show" in interactive mode;
  5651 
  5652 * Pure: 'thms_containing' now takes actual terms as arguments;
  5653 
  5654 * HOL: improved method 'induct' --- now handles non-atomic goals
  5655 (potential INCOMPATIBILITY); tuned error handling;
  5656 
  5657 * HOL: cases and induct rules now provide explicit hints about the
  5658 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5659 any remaining facts are inserted into the goal verbatim;
  5660 
  5661 * HOL: local contexts (aka cases) may now contain term bindings as
  5662 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5663 the result to be shown in each case;
  5664 
  5665 * HOL: added 'recdef_tc' command;
  5666 
  5667 * isatool convert assists in eliminating legacy ML scripts;
  5668 
  5669 
  5670 *** HOL ***
  5671 
  5672 * HOL/Library: a collection of generic theories to be used together
  5673 with main HOL; the theory loader path already includes this directory
  5674 by default; the following existing theories have been moved here:
  5675 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5676 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5677 
  5678 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5679 modelling and verification task performed in Isabelle/HOL +
  5680 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5681 
  5682 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5683 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5684 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5685 'domain', this makes the theory consistent with mathematical
  5686 literature;
  5687 
  5688 * HOL basics: added overloaded operations "inverse" and "divide"
  5689 (infix "/"), syntax for generic "abs" operation, generic summation
  5690 operator \<Sum>;
  5691 
  5692 * HOL/typedef: simplified package, provide more useful rules (see also
  5693 HOL/subset.thy);
  5694 
  5695 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5696 now expressed as a proper nested rule (old-style tactic scripts may
  5697 require atomize_strip_tac to cope with non-atomic premises);
  5698 
  5699 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5700 to "split_conv" (old name still available for compatibility);
  5701 
  5702 * HOL: improved concrete syntax for strings (e.g. allows translation
  5703 rules with string literals);
  5704 
  5705 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5706  and Fleuriot's mechanization of analysis, including the transcendental
  5707  functions for the reals;
  5708 
  5709 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5710 
  5711 
  5712 *** CTT ***
  5713 
  5714 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5715 "lam" is displayed as TWO lambda-symbols
  5716 
  5717 * CTT: theory Main now available, containing everything (that is, Bool
  5718 and Arith);
  5719 
  5720 
  5721 *** General ***
  5722 
  5723 * Pure: the Simplifier has been implemented properly as a derived rule
  5724 outside of the actual kernel (at last!); the overall performance
  5725 penalty in practical applications is about 50%, while reliability of
  5726 the Isabelle inference kernel has been greatly improved;
  5727 
  5728 * print modes "brackets" and "no_brackets" control output of nested =>
  5729 (types) and ==> (props); the default behaviour is "brackets";
  5730 
  5731 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5732 as assumptions as well;
  5733 
  5734 * system: support Poly/ML 4.0;
  5735 
  5736 * system: isatool install handles KDE version 1 or 2;
  5737 
  5738 
  5739 
  5740 New in Isabelle99-1 (October 2000)
  5741 ----------------------------------
  5742 
  5743 *** Overview of INCOMPATIBILITIES ***
  5744 
  5745 * HOL: simplification of natural numbers is much changed; to partly
  5746 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5747 issue the following ML commands:
  5748 
  5749   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5750   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5751 
  5752 * HOL: simplification no longer dives into case-expressions; this is
  5753 controlled by "t.weak_case_cong" for each datatype t;
  5754 
  5755 * HOL: nat_less_induct renamed to less_induct;
  5756 
  5757 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5758 fixsome to patch .thy and .ML sources automatically;
  5759 
  5760   select_equality  -> some_equality
  5761   select_eq_Ex     -> some_eq_ex
  5762   selectI2EX       -> someI2_ex
  5763   selectI2         -> someI2
  5764   selectI          -> someI
  5765   select1_equality -> some1_equality
  5766   Eps_sym_eq       -> some_sym_eq_trivial
  5767   Eps_eq           -> some_eq_trivial
  5768 
  5769 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5770 
  5771 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5772 instead);
  5773 
  5774 * HOL: the recursion equations generated by 'recdef' are now called
  5775 f.simps instead of f.rules;
  5776 
  5777 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5778 
  5779 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5780 sometimes be needed;
  5781 
  5782 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5783 
  5784 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5785 
  5786 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5787 product is now "<*>" instead of "Times"; the lexicographic product is
  5788 now "<*lex*>" instead of "**";
  5789 
  5790 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5791 of main HOL, but was unused); better use HOL's datatype package;
  5792 
  5793 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5794 the old syntax may be recovered as follows:
  5795 
  5796   syntax (symbols)
  5797     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5798       (infixl "\\<oplus>" 100)
  5799 
  5800 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5801 
  5802 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5803 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5804 internally;
  5805 
  5806 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5807 changed from A/r to A//r;
  5808 
  5809 * ZF: new treatment of arithmetic (nat & int) may break some old
  5810 proofs;
  5811 
  5812 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5813 rulify -> rule_format, elimify -> elim_format, ...);
  5814 
  5815 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5816 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5817 should have to change intro!! to intro? only); replaced "delrule" by
  5818 "rule del";
  5819 
  5820 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5821 
  5822 * Provers: strengthened force_tac by using new first_best_tac;
  5823 
  5824 * LaTeX document preparation: several changes of isabelle.sty (see
  5825 lib/texinputs);
  5826 
  5827 
  5828 *** Document preparation ***
  5829 
  5830 * formal comments (text blocks etc.) in new-style theories may now
  5831 contain antiquotations of thm/prop/term/typ/text to be presented
  5832 according to latex print mode; concrete syntax is like this:
  5833 @{term[show_types] "f(x) = a + x"};
  5834 
  5835 * isatool mkdir provides easy setup of Isabelle session directories,
  5836 including proper document sources;
  5837 
  5838 * generated LaTeX sources are now deleted after successful run
  5839 (isatool document -c); may retain a copy somewhere else via -D option
  5840 of isatool usedir;
  5841 
  5842 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5843 style files, achieving self-contained LaTeX sources and simplifying
  5844 LaTeX debugging;
  5845 
  5846 * old-style theories now produce (crude) LaTeX output as well;
  5847 
  5848 * browser info session directories are now self-contained (may be put
  5849 on WWW server seperately); improved graphs of nested sessions; removed
  5850 graph for 'all sessions';
  5851 
  5852 * several improvements in isabelle style files; \isabellestyle{it}
  5853 produces fake math mode output; \isamarkupheader is now \section by
  5854 default; see lib/texinputs/isabelle.sty etc.;
  5855 
  5856 
  5857 *** Isar ***
  5858 
  5859 * Isar/Pure: local results and corresponding term bindings are now
  5860 subject to Hindley-Milner polymorphism (similar to ML); this
  5861 accommodates incremental type-inference very nicely;
  5862 
  5863 * Isar/Pure: new derived language element 'obtain' supports
  5864 generalized existence reasoning;
  5865 
  5866 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5867 support accumulation of results, without applying any rules yet;
  5868 useful to collect intermediate results without explicit name
  5869 references, and for use with transitivity rules with more than 2
  5870 premises;
  5871 
  5872 * Isar/Pure: scalable support for case-analysis type proofs: new
  5873 'case' language element refers to local contexts symbolically, as
  5874 produced by certain proof methods; internally, case names are attached
  5875 to theorems as "tags";
  5876 
  5877 * Isar/Pure: theory command 'hide' removes declarations from
  5878 class/type/const name spaces;
  5879 
  5880 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5881 indicate potential overloading;
  5882 
  5883 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5884 
  5885 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5886 "{a,b,c}" instead of {a,b,c};
  5887 
  5888 * Isar/Pure now provides its own version of intro/elim/dest
  5889 attributes; useful for building new logics, but beware of confusion
  5890 with the version in Provers/classical;
  5891 
  5892 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5893 case name 'antecedent';
  5894 
  5895 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5896 to the current context is now done automatically);
  5897 
  5898 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5899 for definining proof methods in ML;
  5900 
  5901 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5902 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5903 most cases, one should have to change intro!! to intro? only);
  5904 replaced "delrule" by "rule del";
  5905 
  5906 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5907 'symmetric' attribute (the latter supercedes [RS sym]);
  5908 
  5909 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5910 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5911 well (including splits);
  5912 
  5913 * Isar/Provers: Simplifier and Classical methods now support all kind
  5914 of modifiers used in the past, including 'cong', 'iff', etc.
  5915 
  5916 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5917 of Simplifier and Classical reasoner);
  5918 
  5919 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5920 now support named cases; major packages (inductive, datatype, primrec,
  5921 recdef) support case names and properly name parameters;
  5922 
  5923 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5924 monotonicity conditions are extracted to be proven at end of
  5925 calculations;
  5926 
  5927 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5928 method anyway;
  5929 
  5930 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5931 split_if split_if_asm; datatype package provides theorems foo.splits =
  5932 foo.split foo.split_asm for each datatype;
  5933 
  5934 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5935 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5936 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5937 use "(cases (simplified))" method in proper proof texts);
  5938 
  5939 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5940 
  5941 * Isar: names of theorems etc. may be natural numbers as well;
  5942 
  5943 * Isar: 'pr' command: optional arguments for goals_limit and
  5944 ProofContext.prems_limit; no longer prints theory contexts, but only
  5945 proof states;
  5946 
  5947 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5948 additional print modes to be specified; e.g. "pr(latex)" will print
  5949 proof state according to the Isabelle LaTeX style;
  5950 
  5951 * Isar: improved support for emulating tactic scripts, including proof
  5952 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5953 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5954 (for HOL datatypes);
  5955 
  5956 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5957 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5958 'proof method scripts' have to be in depth-first order;
  5959 
  5960 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5961 
  5962 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5963 should instead use individual commands for printing items
  5964 (print_commands, print_methods etc.);
  5965 
  5966 * Isar: added 'nothing' --- the empty list of theorems;
  5967 
  5968 
  5969 *** HOL ***
  5970 
  5971 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5972 corresponding virtual machine and a specification of its bytecode
  5973 verifier and a lightweight bytecode verifier, including proofs of
  5974 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5975 Cornelia Pusch (see also the homepage of project Bali at
  5976 http://isabelle.in.tum.de/Bali/);
  5977 
  5978 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5979 Clemens Ballarin;
  5980 
  5981 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5982 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5983 Rasmussen;
  5984 
  5985 * HOL/Lattice: fundamental concepts of lattice theory and order
  5986 structures, including duals, properties of bounds versus algebraic
  5987 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5988 Theorem for complete lattices etc.; may also serve as a demonstration
  5989 for abstract algebraic reasoning using axiomatic type classes, and
  5990 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5991 
  5992 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5993 von Oheimb;
  5994 
  5995 * HOL/IMPP: extension of IMP with local variables and mutually
  5996 recursive procedures, by David von Oheimb;
  5997 
  5998 * HOL/Lambda: converted into new-style theory and document;
  5999 
  6000 * HOL/ex/Multiquote: example of multiple nested quotations and
  6001 anti-quotations -- basically a generalized version of de-Bruijn
  6002 representation; very useful in avoiding lifting of operations;
  6003 
  6004 * HOL/record: added general record equality rule to simpset; fixed
  6005 select-update simplification procedure to handle extended records as
  6006 well; admit "r" as field name;
  6007 
  6008 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6009 other numeric types and also as the identity of groups, rings, etc.;
  6010 
  6011 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6012 Types nat and int belong to this axclass;
  6013 
  6014 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6015    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6016    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6017   two terms #m*u and #n*u are replaced by #(m+n)*u
  6018     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6019   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6020     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6021 
  6022 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6023 powerful prover for predicate logic but knows nothing of clasets; see
  6024 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6025 
  6026 * HOL: new version of "case_tac" subsumes both boolean case split and
  6027 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6028 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6029 
  6030 * HOL: simplification no longer dives into case-expressions: only the
  6031 selector expression is simplified, but not the remaining arms; to
  6032 enable full simplification of case-expressions for datatype t, you may
  6033 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6034 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6035 
  6036 * HOL/recdef: the recursion equations generated by 'recdef' for
  6037 function 'f' are now called f.simps instead of f.rules; if all
  6038 termination conditions are proved automatically, these simplification
  6039 rules are added to the simpset, as in primrec; rules may be named
  6040 individually as well, resulting in a separate list of theorems for
  6041 each equation;
  6042 
  6043 * HOL/While is a new theory that provides a while-combinator. It
  6044 permits the definition of tail-recursive functions without the
  6045 provision of a termination measure. The latter is necessary once the
  6046 invariant proof rule for while is applied.
  6047 
  6048 * HOL: new (overloaded) notation for the set of elements below/above
  6049 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6050 
  6051 * HOL: theorems impI, allI, ballI bound as "strip";
  6052 
  6053 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6054 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6055 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6056 
  6057 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6058 
  6059 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6060 main HOL, but was unused);
  6061 
  6062 * HOL: fewer consts declared as global (e.g. have to refer to
  6063 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6064 
  6065 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6066 in case of overlap with user translations (e.g. judgements over
  6067 tuples); (note that the underlying logical represenation is still
  6068 bogus);
  6069 
  6070 
  6071 *** ZF ***
  6072 
  6073 * ZF: simplification automatically cancels common terms in arithmetic
  6074 expressions over nat and int;
  6075 
  6076 * ZF: new treatment of nat to minimize type-checking: all operators
  6077 coerce their operands to a natural number using the function natify,
  6078 making the algebraic laws unconditional;
  6079 
  6080 * ZF: as above, for int: operators coerce their operands to an integer
  6081 using the function intify;
  6082 
  6083 * ZF: the integer library now contains many of the usual laws for the
  6084 orderings, including $<=, and monotonicity laws for $+ and $*;
  6085 
  6086 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6087 simplification;
  6088 
  6089 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6090 to the simplifier and classical reasoner simultaneously;
  6091 
  6092 
  6093 *** General ***
  6094 
  6095 * Provers: blast_tac now handles actual object-logic rules as
  6096 assumptions; note that auto_tac uses blast_tac internally as well;
  6097 
  6098 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6099 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6100 
  6101 * Provers: delrules now handles destruct rules as well (no longer need
  6102 explicit make_elim);
  6103 
  6104 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6105   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6106 use instead the strong form,
  6107   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6108 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6109 from destruct-rules;
  6110 
  6111 * Provers: Simplifier.easy_setup provides a fast path to basic
  6112 Simplifier setup for new object-logics;
  6113 
  6114 * Pure: AST translation rules no longer require constant head on LHS;
  6115 
  6116 * Pure: improved name spaces: ambiguous output is qualified; support
  6117 for hiding of names;
  6118 
  6119 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6120 XSYMBOL_HOME; no longer need to do manual configuration in most
  6121 situations;
  6122 
  6123 * system: compression of ML heaps images may now be controlled via -c
  6124 option of isabelle and isatool usedir (currently only observed by
  6125 Poly/ML);
  6126 
  6127 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6128 useful for remote X11);
  6129 
  6130 * system: provide TAGS file for Isabelle sources;
  6131 
  6132 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6133 order;
  6134 
  6135 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6136 timing flag supersedes proof_timing and Toplevel.trace;
  6137 
  6138 * ML: new combinators |>> and |>>> for incremental transformations
  6139 with secondary results (e.g. certain theory extensions):
  6140 
  6141 * ML: PureThy.add_defs gets additional argument to indicate potential
  6142 overloading (usually false);
  6143 
  6144 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6145 results;
  6146 
  6147 
  6148 
  6149 New in Isabelle99 (October 1999)
  6150 --------------------------------
  6151 
  6152 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6153 
  6154 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6155 are no longer simplified.  (This allows the simplifier to unfold recursive
  6156 functional programs.)  To restore the old behaviour, declare
  6157 
  6158     Delcongs [if_weak_cong];
  6159 
  6160 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6161 complement;
  6162 
  6163 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6164 
  6165 * HOL/datatype: mutual_induct_tac no longer exists --
  6166   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6167 
  6168 * HOL/typedef: fixed type inference for representing set; type
  6169 arguments now have to occur explicitly on the rhs as type constraints;
  6170 
  6171 * ZF: The con_defs part of an inductive definition may no longer refer
  6172 to constants declared in the same theory;
  6173 
  6174 * HOL, ZF: the function mk_cases, generated by the inductive
  6175 definition package, has lost an argument.  To simplify its result, it
  6176 uses the default simpset instead of a supplied list of theorems.
  6177 
  6178 * HOL/List: the constructors of type list are now Nil and Cons;
  6179 
  6180 * Simplifier: the type of the infix ML functions
  6181         setSSolver addSSolver setSolver addSolver
  6182 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6183 for packaging solvers. A solver is created via
  6184         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6185 where the string argument is only a comment.
  6186 
  6187 
  6188 *** Proof tools ***
  6189 
  6190 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6191 decision procedure for linear arithmetic. Currently it is used for
  6192 types `nat', `int', and `real' in HOL (see below); it can, should and
  6193 will be instantiated for other types and logics as well.
  6194 
  6195 * The simplifier now accepts rewrite rules with flexible heads, eg
  6196      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6197   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6198   matching.
  6199 
  6200 
  6201 *** General ***
  6202 
  6203 * New Isabelle/Isar subsystem provides an alternative to traditional
  6204 tactical theorem proving; together with the ProofGeneral/isar user
  6205 interface it offers an interactive environment for developing human
  6206 readable proof documents (Isar == Intelligible semi-automated
  6207 reasoning); for further information see isatool doc isar-ref,
  6208 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6209 
  6210 * improved and simplified presentation of theories: better HTML markup
  6211 (including colors), graph views in several sizes; isatool usedir now
  6212 provides a proper interface for user theories (via -P option); actual
  6213 document preparation based on (PDF)LaTeX is available as well (for
  6214 new-style theories only); see isatool doc system for more information;
  6215 
  6216 * native support for Proof General, both for classic Isabelle and
  6217 Isabelle/Isar;
  6218 
  6219 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  6220 using the graph browser tool;
  6221 
  6222 * Isabelle manuals now also available as PDF;
  6223 
  6224 * theory loader rewritten from scratch (may not be fully
  6225 bug-compatible); old loadpath variable has been replaced by show_path,
  6226 add_path, del_path, reset_path functions; new operations such as
  6227 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6228 isatool doc ref);
  6229 
  6230 * improved isatool install: option -k creates KDE application icon,
  6231 option -p DIR installs standalone binaries;
  6232 
  6233 * added ML_PLATFORM setting (useful for cross-platform installations);
  6234 more robust handling of platform specific ML images for SML/NJ;
  6235 
  6236 * the settings environment is now statically scoped, i.e. it is never
  6237 created again in sub-processes invoked from isabelle, isatool, or
  6238 Isabelle;
  6239 
  6240 * path element specification '~~' refers to '$ISABELLE_HOME';
  6241 
  6242 * in locales, the "assumes" and "defines" parts may be omitted if
  6243 empty;
  6244 
  6245 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  6246 long arrows);
  6247 
  6248 * new print_mode "HTML";
  6249 
  6250 * new flag show_tags controls display of tags of theorems (which are
  6251 basically just comments that may be attached by some tools);
  6252 
  6253 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  6254 mode and goal output format:
  6255 
  6256 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  6257 244c244
  6258 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  6259 ---
  6260 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  6261 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  6262 181c181
  6263 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  6264 ---
  6265 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  6266 
  6267 * function bind_thms stores lists of theorems (cf. bind_thm);
  6268 
  6269 * new shorthand tactics ftac, eatac, datac, fatac;
  6270 
  6271 * qed (and friends) now accept "" as result name; in that case the
  6272 theorem is not stored, but proper checks and presentation of the
  6273 result still apply;
  6274 
  6275 * theorem database now also indexes constants "Trueprop", "all",
  6276 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  6277 
  6278 
  6279 *** HOL ***
  6280 
  6281 ** HOL arithmetic **
  6282 
  6283 * There are now decision procedures for linear arithmetic over nat and
  6284 int:
  6285 
  6286 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  6287 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  6288 are treated as atomic; subformulae not involving type `nat' or `int'
  6289 are ignored; quantified subformulae are ignored unless they are
  6290 positive universal or negative existential. The tactic has to be
  6291 invoked by hand and can be a little bit slow. In particular, the
  6292 running time is exponential in the number of occurrences of `min' and
  6293 `max', and `-' on `nat'.
  6294 
  6295 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  6296 (negated) (in)equalities among the premises and the conclusion into
  6297 account (i.e. no compound formulae) and does not know about `min' and
  6298 `max', and `-' on `nat'. It is fast and is used automatically by the
  6299 simplifier.
  6300 
  6301 NB: At the moment, these decision procedures do not cope with mixed
  6302 nat/int formulae where the two parts interact, such as `m < n ==>
  6303 int(m) < int(n)'.
  6304 
  6305 * HOL/Numeral provides a generic theory of numerals (encoded
  6306 efficiently as bit strings); setup for types nat/int/real is in place;
  6307 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  6308 int, existing theories and proof scripts may require a few additional
  6309 type constraints;
  6310 
  6311 * integer division and remainder can now be performed on constant
  6312 arguments;
  6313 
  6314 * many properties of integer multiplication, division and remainder
  6315 are now available;
  6316 
  6317 * An interface to the Stanford Validity Checker (SVC) is available through the
  6318 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  6319 are proved automatically.  SVC must be installed separately, and its results
  6320 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  6321 invocation of the underlying oracle).  For SVC see
  6322   http://verify.stanford.edu/SVC
  6323 
  6324 * IsaMakefile: the HOL-Real target now builds an actual image;
  6325 
  6326 
  6327 ** HOL misc **
  6328 
  6329 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  6330 (in Isabelle/Isar) -- by Gertrud Bauer;
  6331 
  6332 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  6333 analysis for assembly languages with subtypes;
  6334 
  6335 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  6336 -- avoids syntactic ambiguities and treats state, transition, and
  6337 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  6338 changed syntax and (many) tactics;
  6339 
  6340 * HOL/inductive: Now also handles more general introduction rules such
  6341   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  6342   theorems are now maintained within the theory (maintained via the
  6343   "mono" attribute);
  6344 
  6345 * HOL/datatype: Now also handles arbitrarily branching datatypes
  6346   (using function types) such as
  6347 
  6348   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  6349 
  6350 * HOL/record: record_simproc (part of the default simpset) takes care
  6351 of selectors applied to updated records; record_split_tac is no longer
  6352 part of the default claset; update_defs may now be removed from the
  6353 simpset in many cases; COMPATIBILITY: old behavior achieved by
  6354 
  6355   claset_ref () := claset() addSWrapper record_split_wrapper;
  6356   Delsimprocs [record_simproc]
  6357 
  6358 * HOL/typedef: fixed type inference for representing set; type
  6359 arguments now have to occur explicitly on the rhs as type constraints;
  6360 
  6361 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  6362 names rather than an ML expression;
  6363 
  6364 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  6365 supplied later.  Program schemes can be defined, such as
  6366     "While B C s = (if B s then While B C (C s) else s)"
  6367 where the well-founded relation can be chosen after B and C have been given.
  6368 
  6369 * HOL/List: the constructors of type list are now Nil and Cons;
  6370 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  6371 course, ML tools referring to List.list.op # etc. have to be adapted;
  6372 
  6373 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  6374 disabled by default; run isabelle with option -m HOL to get back to
  6375 the original Gordon/HOL-style output;
  6376 
  6377 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  6378 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  6379 
  6380 * HOL basic syntax simplified (more orthogonal): all variants of
  6381 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  6382 Eps operator is provided as well: "SOME x. P[x]";
  6383 
  6384 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  6385 
  6386 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  6387 thus available for user theories;
  6388 
  6389 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  6390 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  6391 time;
  6392 
  6393 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  6394 several times and then mp;
  6395 
  6396 
  6397 *** LK ***
  6398 
  6399 * the notation <<...>> is now available as a notation for sequences of
  6400 formulas;
  6401 
  6402 * the simplifier is now installed
  6403 
  6404 * the axiom system has been generalized (thanks to Soren Heilmann)
  6405 
  6406 * the classical reasoner now has a default rule database
  6407 
  6408 
  6409 *** ZF ***
  6410 
  6411 * new primrec section allows primitive recursive functions to be given
  6412 directly (as in HOL) over datatypes and the natural numbers;
  6413 
  6414 * new tactics induct_tac and exhaust_tac for induction (or case
  6415 analysis) over datatypes and the natural numbers;
  6416 
  6417 * the datatype declaration of type T now defines the recursor T_rec;
  6418 
  6419 * simplification automatically does freeness reasoning for datatype
  6420 constructors;
  6421 
  6422 * automatic type-inference, with AddTCs command to insert new
  6423 type-checking rules;
  6424 
  6425 * datatype introduction rules are now added as Safe Introduction rules
  6426 to the claset;
  6427 
  6428 * the syntax "if P then x else y" is now available in addition to
  6429 if(P,x,y);
  6430 
  6431 
  6432 *** Internal programming interfaces ***
  6433 
  6434 * tuned simplifier trace output; new flag debug_simp;
  6435 
  6436 * structures Vartab / Termtab (instances of TableFun) offer efficient
  6437 tables indexed by indexname_ord / term_ord (compatible with aconv);
  6438 
  6439 * AxClass.axclass_tac lost the theory argument;
  6440 
  6441 * tuned current_goals_markers semantics: begin / end goal avoids
  6442 printing empty lines;
  6443 
  6444 * removed prs and prs_fn hook, which was broken because it did not
  6445 include \n in its semantics, forcing writeln to add one
  6446 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  6447 string -> unit if you really want to output text without newline;
  6448 
  6449 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  6450 plain output, interface builders may have to enable 'isabelle_font'
  6451 mode to get Isabelle font glyphs as before;
  6452 
  6453 * refined token_translation interface; INCOMPATIBILITY: output length
  6454 now of type real instead of int;
  6455 
  6456 * theory loader actions may be traced via new ThyInfo.add_hook
  6457 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  6458 your own database of information attached to *whole* theories -- as
  6459 opposed to intra-theory data slots offered via TheoryDataFun;
  6460 
  6461 * proper handling of dangling sort hypotheses (at last!);
  6462 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  6463 extra sort hypotheses that can be witnessed from the type signature;
  6464 the force_strip_shyps flag is gone, any remaining shyps are simply
  6465 left in the theorem (with a warning issued by strip_shyps_warning);
  6466 
  6467 
  6468 
  6469 New in Isabelle98-1 (October 1998)
  6470 ----------------------------------
  6471 
  6472 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6473 
  6474 * several changes of automated proof tools;
  6475 
  6476 * HOL: major changes to the inductive and datatype packages, including
  6477 some minor incompatibilities of theory syntax;
  6478 
  6479 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  6480 called `inj_on';
  6481 
  6482 * HOL: removed duplicate thms in Arith:
  6483   less_imp_add_less  should be replaced by  trans_less_add1
  6484   le_imp_add_le      should be replaced by  trans_le_add1
  6485 
  6486 * HOL: unary minus is now overloaded (new type constraints may be
  6487 required);
  6488 
  6489 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  6490 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  6491 now taken as an integer constant.
  6492 
  6493 * Pure: ML function 'theory_of' renamed to 'theory';
  6494 
  6495 
  6496 *** Proof tools ***
  6497 
  6498 * Simplifier:
  6499   1. Asm_full_simp_tac is now more aggressive.
  6500      1. It will sometimes reorient premises if that increases their power to
  6501         simplify.
  6502      2. It does no longer proceed strictly from left to right but may also
  6503         rotate premises to achieve further simplification.
  6504      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  6505      old Asm_full_simp_tac in that it does not rotate premises.
  6506   2. The simplifier now knows a little bit about nat-arithmetic.
  6507 
  6508 * Classical reasoner: wrapper mechanism for the classical reasoner now
  6509 allows for selected deletion of wrappers, by introduction of names for
  6510 wrapper functionals.  This implies that addbefore, addSbefore,
  6511 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  6512 and that adding two tactics with the same name overwrites the first
  6513 one (emitting a warning).
  6514   type wrapper = (int -> tactic) -> (int -> tactic)
  6515   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  6516   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  6517   delWrapper, delSWrapper: claset *  string            -> claset
  6518   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  6519 
  6520 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  6521 semantics; addbefore now affects only the unsafe part of step_tac
  6522 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  6523 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  6524 by Force_tac;
  6525 
  6526 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  6527 compWrapper; added safe wrapper (and access functions for it);
  6528 
  6529 * HOL/split_all_tac is now much faster and fails if there is nothing
  6530 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  6531 and the names of the automatically generated variables have changed.
  6532 split_all_tac has moved within claset() from unsafe wrappers to safe
  6533 wrappers, which means that !!-bound variables are split much more
  6534 aggressively, and safe_tac and clarify_tac now split such variables.
  6535 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  6536 Note: the same holds for record_split_tac, which does the job of
  6537 split_all_tac for record fields.
  6538 
  6539 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  6540 permanently to the default simpset using Addsplits just like
  6541 Addsimps. They can be removed via Delsplits just like
  6542 Delsimps. Lower-case versions are also available.
  6543 
  6544 * HOL/Simplifier: The rule split_if is now part of the default
  6545 simpset. This means that the simplifier will eliminate all occurrences
  6546 of if-then-else in the conclusion of a goal. To prevent this, you can
  6547 either remove split_if completely from the default simpset by
  6548 `Delsplits [split_if]' or remove it in a specific call of the
  6549 simplifier using `... delsplits [split_if]'.  You can also add/delete
  6550 other case splitting rules to/from the default simpset: every datatype
  6551 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  6552 t is the name of the datatype).
  6553 
  6554 * Classical reasoner / Simplifier combination: new force_tac (and
  6555 derivatives Force_tac, force) combines rewriting and classical
  6556 reasoning (and whatever other tools) similarly to auto_tac, but is
  6557 aimed to solve the given subgoal completely.
  6558 
  6559 
  6560 *** General ***
  6561 
  6562 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  6563 and `goalw': the theory is no longer needed as an explicit argument -
  6564 the current theory context is used; assumptions are no longer returned
  6565 at the ML-level unless one of them starts with ==> or !!; it is
  6566 recommended to convert to these new commands using isatool fixgoal
  6567 (backup your sources first!);
  6568 
  6569 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  6570 the current theory context, and 'theory' to lookup stored theories;
  6571 
  6572 * new theory section 'locale' for declaring constants, assumptions and
  6573 definitions that have local scope;
  6574 
  6575 * new theory section 'nonterminals' for purely syntactic types;
  6576 
  6577 * new theory section 'setup' for generic ML setup functions
  6578 (e.g. package initialization);
  6579 
  6580 * the distribution now includes Isabelle icons: see
  6581 lib/logo/isabelle-{small,tiny}.xpm;
  6582 
  6583 * isatool install - install binaries with absolute references to
  6584 ISABELLE_HOME/bin;
  6585 
  6586 * isatool logo -- create instances of the Isabelle logo (as EPS);
  6587 
  6588 * print mode 'emacs' reserved for Isamode;
  6589 
  6590 * support multiple print (ast) translations per constant name;
  6591 
  6592 * theorems involving oracles are now printed with a suffixed [!];
  6593 
  6594 
  6595 *** HOL ***
  6596 
  6597 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  6598 
  6599 * HOL/inductive package reorganized and improved: now supports mutual
  6600 definitions such as
  6601 
  6602   inductive EVEN ODD
  6603     intrs
  6604       null "0 : EVEN"
  6605       oddI "n : EVEN ==> Suc n : ODD"
  6606       evenI "n : ODD ==> Suc n : EVEN"
  6607 
  6608 new theorem list "elims" contains an elimination rule for each of the
  6609 recursive sets; inductive definitions now handle disjunctive premises
  6610 correctly (also ZF);
  6611 
  6612 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  6613 "mutual_induct" no longer exists - the induction rule is always
  6614 contained in "induct";
  6615 
  6616 
  6617 * HOL/datatype package re-implemented and greatly improved: now
  6618 supports mutually recursive datatypes such as
  6619 
  6620   datatype
  6621     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  6622             | SUM ('a aexp) ('a aexp)
  6623             | DIFF ('a aexp) ('a aexp)
  6624             | NUM 'a
  6625   and
  6626     'a bexp = LESS ('a aexp) ('a aexp)
  6627             | AND ('a bexp) ('a bexp)
  6628             | OR ('a bexp) ('a bexp)
  6629 
  6630 as well as indirectly recursive datatypes such as
  6631 
  6632   datatype
  6633     ('a, 'b) term = Var 'a
  6634                   | App 'b ((('a, 'b) term) list)
  6635 
  6636 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  6637 induction on mutually / indirectly recursive datatypes.
  6638 
  6639 Primrec equations are now stored in theory and can be accessed via
  6640 <function_name>.simps.
  6641 
  6642 INCOMPATIBILITIES:
  6643 
  6644   - Theories using datatypes must now have theory Datatype as an
  6645     ancestor.
  6646   - The specific <typename>.induct_tac no longer exists - use the
  6647     generic induct_tac instead.
  6648   - natE has been renamed to nat.exhaust - use exhaust_tac
  6649     instead of res_inst_tac ... natE. Note that the variable
  6650     names in nat.exhaust differ from the names in natE, this
  6651     may cause some "fragile" proofs to fail.
  6652   - The theorems split_<typename>_case and split_<typename>_case_asm
  6653     have been renamed to <typename>.split and <typename>.split_asm.
  6654   - Since default sorts of type variables are now handled correctly,
  6655     some datatype definitions may have to be annotated with explicit
  6656     sort constraints.
  6657   - Primrec definitions no longer require function name and type
  6658     of recursive argument.
  6659 
  6660 Consider using isatool fixdatatype to adapt your theories and proof
  6661 scripts to the new package (backup your sources first!).
  6662 
  6663 
  6664 * HOL/record package: considerably improved implementation; now
  6665 includes concrete syntax for record types, terms, updates; theorems
  6666 for surjective pairing and splitting !!-bound record variables; proof
  6667 support is as follows:
  6668 
  6669   1) standard conversions (selectors or updates applied to record
  6670 constructor terms) are part of the standard simpset;
  6671 
  6672   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  6673 made part of standard simpset and claset via addIffs;
  6674 
  6675   3) a tactic for record field splitting (record_split_tac) is part of
  6676 the standard claset (addSWrapper);
  6677 
  6678 To get a better idea about these rules you may retrieve them via
  6679 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  6680 the name of your record type.
  6681 
  6682 The split tactic 3) conceptually simplifies by the following rule:
  6683 
  6684   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  6685 
  6686 Thus any record variable that is bound by meta-all will automatically
  6687 blow up into some record constructor term, consequently the
  6688 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  6689 solve record problems automatically.
  6690 
  6691 
  6692 * reorganized the main HOL image: HOL/Integ and String loaded by
  6693 default; theory Main includes everything;
  6694 
  6695 * automatic simplification of integer sums and comparisons, using cancellation;
  6696 
  6697 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  6698 
  6699 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  6700 
  6701 * many new identities for unions, intersections, set difference, etc.;
  6702 
  6703 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6704 called split_if, split_split, split_sum_case and split_nat_case (to go
  6705 with add/delsplits);
  6706 
  6707 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6708 (?x::unit) = (); this is made part of the default simpset, which COULD
  6709 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6710 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6711 unit_abs_eta_conv is added in order to counter the effect of
  6712 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6713 %u.f();
  6714 
  6715 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6716 makes more sense);
  6717 
  6718 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6719   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6720   disjointness reasoning but breaking a few old proofs.
  6721 
  6722 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  6723 to 'converse' from 'inverse' (for compatibility with ZF and some
  6724 literature);
  6725 
  6726 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  6727 the well-founded relation;
  6728 
  6729 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  6730     Compl A.  The "Compl" syntax remains available as input syntax for this
  6731     release ONLY.
  6732 
  6733 * HOL/Update: new theory of function updates:
  6734     f(a:=b) == %x. if x=a then b else f x
  6735 may also be iterated as in f(a:=b,c:=d,...);
  6736 
  6737 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  6738 
  6739 * HOL/List:
  6740   - new function list_update written xs[i:=v] that updates the i-th
  6741     list position. May also be iterated as in xs[i:=a,j:=b,...].
  6742   - new function `upt' written [i..j(] which generates the list
  6743     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  6744     bound write [i..j], which is a shorthand for [i..j+1(].
  6745   - new lexicographic orderings and corresponding wellfoundedness theorems.
  6746 
  6747 * HOL/Arith:
  6748   - removed 'pred' (predecessor) function;
  6749   - generalized some theorems about n-1;
  6750   - many new laws about "div" and "mod";
  6751   - new laws about greatest common divisors (see theory ex/Primes);
  6752 
  6753 * HOL/Relation: renamed the relational operator r^-1 "converse"
  6754 instead of "inverse";
  6755 
  6756 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  6757   of the multiset ordering;
  6758 
  6759 * directory HOL/Real: a construction of the reals using Dedekind cuts
  6760   (not included by default);
  6761 
  6762 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  6763 
  6764 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  6765   programs, i.e. different program variables may have different types.
  6766 
  6767 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6768   [previously, this check worked only if the rewrite rule was unconditional]
  6769   Now rew can involve either definitions or equalities (either == or =).
  6770 
  6771 
  6772 *** ZF ***
  6773 
  6774 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  6775   only the theorems proved on ZF.ML;
  6776 
  6777 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6778   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6779   disjointness reasoning but breaking a few old proofs.
  6780 
  6781 * ZF/Update: new theory of function updates
  6782     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  6783   may also be iterated as in f(a:=b,c:=d,...);
  6784 
  6785 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6786 
  6787 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6788   [previously, this check worked only if the rewrite rule was unconditional]
  6789   Now rew can involve either definitions or equalities (either == or =).
  6790 
  6791 * case_tac provided for compatibility with HOL
  6792     (like the old excluded_middle_tac, but with subgoals swapped)
  6793 
  6794 
  6795 *** Internal programming interfaces ***
  6796 
  6797 * Pure: several new basic modules made available for general use, see
  6798 also src/Pure/README;
  6799 
  6800 * improved the theory data mechanism to support encapsulation (data
  6801 kind name replaced by private Object.kind, acting as authorization
  6802 key); new type-safe user interface via functor TheoryDataFun; generic
  6803 print_data function becomes basically useless;
  6804 
  6805 * removed global_names compatibility flag -- all theory declarations
  6806 are qualified by default;
  6807 
  6808 * module Pure/Syntax now offers quote / antiquote translation
  6809 functions (useful for Hoare logic etc. with implicit dependencies);
  6810 see HOL/ex/Antiquote for an example use;
  6811 
  6812 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6813 cterm -> thm;
  6814 
  6815 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6816 subgoal;
  6817 
  6818 * Display.print_goals function moved to Locale.print_goals;
  6819 
  6820 * standard print function for goals supports current_goals_markers
  6821 variable for marking begin of proof, end of proof, start of goal; the
  6822 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6823 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6824 for example;
  6825 
  6826 
  6827 
  6828 New in Isabelle98 (January 1998)
  6829 --------------------------------
  6830 
  6831 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6832 
  6833 * changed lexical syntax of terms / types: dots made part of long
  6834 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6835 
  6836 * simpset (and claset) reference variable replaced by functions
  6837 simpset / simpset_ref;
  6838 
  6839 * no longer supports theory aliases (via merge) and non-trivial
  6840 implicit merge of thms' signatures;
  6841 
  6842 * most internal names of constants changed due to qualified names;
  6843 
  6844 * changed Pure/Sequence interface (see Pure/seq.ML);
  6845 
  6846 
  6847 *** General Changes ***
  6848 
  6849 * hierachically structured name spaces (for consts, types, axms, thms
  6850 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6851 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6852 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6853 long_names for fully qualified output names; NOTE: ML programs
  6854 (special tactics, packages etc.) referring to internal names may have
  6855 to be adapted to cope with fully qualified names; in case of severe
  6856 backward campatibility problems try setting 'global_names' at compile
  6857 time to have enrything declared within a flat name space; one may also
  6858 fine tune name declarations in theories via the 'global' and 'local'
  6859 section;
  6860 
  6861 * reimplemented the implicit simpset and claset using the new anytype
  6862 data filed in signatures; references simpset:simpset ref etc. are
  6863 replaced by functions simpset:unit->simpset and
  6864 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6865 to patch your ML files accordingly;
  6866 
  6867 * HTML output now includes theory graph data for display with Java
  6868 applet or isatool browser; data generated automatically via isatool
  6869 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6870 
  6871 * defs may now be conditional; improved rewrite_goals_tac to handle
  6872 conditional equations;
  6873 
  6874 * defs now admits additional type arguments, using TYPE('a) syntax;
  6875 
  6876 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6877 creates a new theory node; implicit merge of thms' signatures is
  6878 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6879 transfer:theory->thm->thm in (rare) cases;
  6880 
  6881 * improved handling of draft signatures / theories; draft thms (and
  6882 ctyps, cterms) are automatically promoted to real ones;
  6883 
  6884 * slightly changed interfaces for oracles: admit many per theory, named
  6885 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6886 
  6887 * print_goals: optional output of const types (set show_consts and
  6888 show_types);
  6889 
  6890 * improved output of warnings (###) and errors (***);
  6891 
  6892 * subgoal_tac displays a warning if the new subgoal has type variables;
  6893 
  6894 * removed old README and Makefiles;
  6895 
  6896 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6897 
  6898 * removed obsolete init_pps and init_database;
  6899 
  6900 * deleted the obsolete tactical STATE, which was declared by
  6901     fun STATE tacfun st = tacfun st st;
  6902 
  6903 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6904 (which abbreviates $HOME);
  6905 
  6906 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6907 use isatool fixseq to adapt your ML programs (this works for fully
  6908 qualified references to the Sequence structure only!);
  6909 
  6910 * use_thy no longer requires writable current directory; it always
  6911 reloads .ML *and* .thy file, if either one is out of date;
  6912 
  6913 
  6914 *** Classical Reasoner ***
  6915 
  6916 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6917 tactics that use classical reasoning to simplify a subgoal without
  6918 splitting it into several subgoals;
  6919 
  6920 * Safe_tac: like safe_tac but uses the default claset;
  6921 
  6922 
  6923 *** Simplifier ***
  6924 
  6925 * added simplification meta rules:
  6926     (asm_)(full_)simplify: simpset -> thm -> thm;
  6927 
  6928 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6929 logics (again);
  6930 
  6931 * added prems argument to simplification procedures;
  6932 
  6933 * HOL, FOL, ZF: added infix function `addsplits':
  6934   instead of `<simpset> setloop (split_tac <thms>)'
  6935   you can simply write `<simpset> addsplits <thms>'
  6936 
  6937 
  6938 *** Syntax ***
  6939 
  6940 * TYPE('a) syntax for type reflection terms;
  6941 
  6942 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6943 
  6944 * pretty printer: changed order of mixfix annotation preference (again!);
  6945 
  6946 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6947 
  6948 
  6949 *** HOL ***
  6950 
  6951 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6952   with `addloop' of the simplifier to faciliate case splitting in premises.
  6953 
  6954 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6955 
  6956 * HOL/Auth: new protocol proofs including some for the Internet
  6957   protocol TLS;
  6958 
  6959 * HOL/Map: new theory of `maps' a la VDM;
  6960 
  6961 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6962 cancelling out common nat summands from =, <, <= (in)equalities, or
  6963 differences; simplification procedures nat_cancel_factor for
  6964 cancelling common factor from =, <, <= (in)equalities over natural
  6965 sums; nat_cancel contains both kinds of procedures, it is installed by
  6966 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6967 
  6968 * HOL/simplifier: terms of the form
  6969   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6970   are rewritten to
  6971   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6972   and those of the form
  6973   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6974   are rewritten to
  6975   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6976 
  6977 * HOL/datatype
  6978   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6979 
  6980   P(t_case f1 ... fn x) =
  6981      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6982         ...
  6983        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6984      )
  6985 
  6986   and a theorem `split_t_case_asm' of the form
  6987 
  6988   P(t_case f1 ... fn x) =
  6989     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6990         ...
  6991        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6992      )
  6993   which can be added to a simpset via `addsplits'. The existing theorems
  6994   expand_list_case and expand_option_case have been renamed to
  6995   split_list_case and split_option_case.
  6996 
  6997 * HOL/Arithmetic:
  6998   - `pred n' is automatically converted to `n-1'.
  6999     Users are strongly encouraged not to use `pred' any longer,
  7000     because it will disappear altogether at some point.
  7001   - Users are strongly encouraged to write "0 < n" rather than
  7002     "n ~= 0". Theorems and proof tools have been modified towards this
  7003     `standard'.
  7004 
  7005 * HOL/Lists:
  7006   the function "set_of_list" has been renamed "set" (and its theorems too);
  7007   the function "nth" now takes its arguments in the reverse order and
  7008   has acquired the infix notation "!" as in "xs!n".
  7009 
  7010 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7011 
  7012 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7013   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7014 
  7015 * HOL/record: extensible records with schematic structural subtyping
  7016 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7017 still lacks various theorems and concrete record syntax;
  7018 
  7019 
  7020 *** HOLCF ***
  7021 
  7022 * removed "axioms" and "generated by" sections;
  7023 
  7024 * replaced "ops" section by extended "consts" section, which is capable of
  7025   handling the continuous function space "->" directly;
  7026 
  7027 * domain package:
  7028   . proves theorems immediately and stores them in the theory,
  7029   . creates hierachical name space,
  7030   . now uses normal mixfix annotations (instead of cinfix...),
  7031   . minor changes to some names and values (for consistency),
  7032   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7033   . separator between mutual domain defs: changed "," to "and",
  7034   . improved handling of sort constraints;  now they have to
  7035     appear on the left-hand side of the equations only;
  7036 
  7037 * fixed LAM <x,y,zs>.b syntax;
  7038 
  7039 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7040 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7041 
  7042 
  7043 *** FOL and ZF ***
  7044 
  7045 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7046   with `addloop' of the simplifier to faciliate case splitting in premises.
  7047 
  7048 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7049 in HOL, they strip ALL and --> from proved theorems;
  7050 
  7051 
  7052 
  7053 New in Isabelle94-8 (May 1997)
  7054 ------------------------------
  7055 
  7056 *** General Changes ***
  7057 
  7058 * new utilities to build / run / maintain Isabelle etc. (in parts
  7059 still somewhat experimental); old Makefiles etc. still functional;
  7060 
  7061 * new 'Isabelle System Manual';
  7062 
  7063 * INSTALL text, together with ./configure and ./build scripts;
  7064 
  7065 * reimplemented type inference for greater efficiency, better error
  7066 messages and clean internal interface;
  7067 
  7068 * prlim command for dealing with lots of subgoals (an easier way of
  7069 setting goals_limit);
  7070 
  7071 
  7072 *** Syntax ***
  7073 
  7074 * supports alternative (named) syntax tables (parser and pretty
  7075 printer); internal interface is provided by add_modesyntax(_i);
  7076 
  7077 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7078 be used in conjunction with the Isabelle symbol font; uses the
  7079 "symbols" syntax table;
  7080 
  7081 * added token_translation interface (may translate name tokens in
  7082 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7083 the current print_mode); IMPORTANT: user print translation functions
  7084 are responsible for marking newly introduced bounds
  7085 (Syntax.mark_boundT);
  7086 
  7087 * token translations for modes "xterm" and "xterm_color" that display
  7088 names in bold, underline etc. or colors (which requires a color
  7089 version of xterm);
  7090 
  7091 * infixes may now be declared with names independent of their syntax;
  7092 
  7093 * added typed_print_translation (like print_translation, but may
  7094 access type of constant);
  7095 
  7096 
  7097 *** Classical Reasoner ***
  7098 
  7099 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7100 some limitations.  Blast_tac...
  7101   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7102   + ignores elimination rules that don't have the correct format
  7103         (the conclusion MUST be a formula variable)
  7104   + ignores types, which can make HOL proofs fail
  7105   + rules must not require higher-order unification, e.g. apply_type in ZF
  7106     [message "Function Var's argument not a bound variable" relates to this]
  7107   + its proof strategy is more general but can actually be slower
  7108 
  7109 * substitution with equality assumptions no longer permutes other
  7110 assumptions;
  7111 
  7112 * minor changes in semantics of addafter (now called addaltern); renamed
  7113 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7114 (and access functions for it);
  7115 
  7116 * improved combination of classical reasoner and simplifier:
  7117   + functions for handling clasimpsets
  7118   + improvement of addss: now the simplifier is called _after_ the
  7119     safe steps.
  7120   + safe variant of addss called addSss: uses safe simplifications
  7121     _during_ the safe steps. It is more complete as it allows multiple
  7122     instantiations of unknowns (e.g. with slow_tac).
  7123 
  7124 *** Simplifier ***
  7125 
  7126 * added interface for simplification procedures (functions that
  7127 produce *proven* rewrite rules on the fly, depending on current
  7128 redex);
  7129 
  7130 * ordering on terms as parameter (used for ordered rewriting);
  7131 
  7132 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7133 
  7134 * the solver is now split into a safe and an unsafe part.
  7135 This should be invisible for the normal user, except that the
  7136 functions setsolver and addsolver have been renamed to setSolver and
  7137 addSolver; added safe_asm_full_simp_tac;
  7138 
  7139 
  7140 *** HOL ***
  7141 
  7142 * a generic induction tactic `induct_tac' which works for all datatypes and
  7143 also for type `nat';
  7144 
  7145 * a generic case distinction tactic `exhaust_tac' which works for all
  7146 datatypes and also for type `nat';
  7147 
  7148 * each datatype comes with a function `size';
  7149 
  7150 * patterns in case expressions allow tuple patterns as arguments to
  7151 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7152 
  7153 * primrec now also works with type nat;
  7154 
  7155 * recdef: a new declaration form, allows general recursive functions to be
  7156 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7157 
  7158 * the constant for negation has been renamed from "not" to "Not" to
  7159 harmonize with FOL, ZF, LK, etc.;
  7160 
  7161 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7162 infinite lists;
  7163 
  7164 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7165 
  7166 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7167 problems in commutative rings, using axiomatic type classes for + and *;
  7168 
  7169 * more examples in HOL/MiniML and HOL/Auth;
  7170 
  7171 * more default rewrite rules for quantifiers, union/intersection;
  7172 
  7173 * a new constant `arbitrary == @x.False';
  7174 
  7175 * HOLCF/IOA replaces old HOL/IOA;
  7176 
  7177 * HOLCF changes: derived all rules and arities
  7178   + axiomatic type classes instead of classes
  7179   + typedef instead of faking type definitions
  7180   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7181   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7182   + eliminated the types void, one, tr
  7183   + use unit lift and bool lift (with translations) instead of one and tr
  7184   + eliminated blift from Lift3.thy (use Def instead of blift)
  7185   all eliminated rules are derived as theorems --> no visible changes ;
  7186 
  7187 
  7188 *** ZF ***
  7189 
  7190 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  7191 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  7192 as ZF_cs addSIs [equalityI];
  7193 
  7194 
  7195 
  7196 New in Isabelle94-7 (November 96)
  7197 ---------------------------------
  7198 
  7199 * allowing negative levels (as offsets) in prlev and choplev;
  7200 
  7201 * super-linear speedup for large simplifications;
  7202 
  7203 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  7204 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  7205 FAIL); can suppress it using the command Delsimps (ex_simps @
  7206 all_simps); De Morgan laws are also now included, by default;
  7207 
  7208 * improved printing of ==>  :  ~:
  7209 
  7210 * new object-logic "Sequents" adds linear logic, while replacing LK
  7211 and Modal (thanks to Sara Kalvala);
  7212 
  7213 * HOL/Auth: correctness proofs for authentication protocols;
  7214 
  7215 * HOL: new auto_tac combines rewriting and classical reasoning (many
  7216 examples on HOL/Auth);
  7217 
  7218 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  7219 the rewriter and classical reasoner simultaneously;
  7220 
  7221 * function uresult no longer returns theorems in "standard" format;
  7222 regain previous version by: val uresult = standard o uresult;
  7223 
  7224 
  7225 
  7226 New in Isabelle94-6
  7227 -------------------
  7228 
  7229 * oracles -- these establish an interface between Isabelle and trusted
  7230 external reasoners, which may deliver results as theorems;
  7231 
  7232 * proof objects (in particular record all uses of oracles);
  7233 
  7234 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  7235 
  7236 * "constdefs" section in theory files;
  7237 
  7238 * "primrec" section (HOL) no longer requires names;
  7239 
  7240 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  7241 
  7242 
  7243 
  7244 New in Isabelle94-5
  7245 -------------------
  7246 
  7247 * reduced space requirements;
  7248 
  7249 * automatic HTML generation from theories;
  7250 
  7251 * theory files no longer require "..." (quotes) around most types;
  7252 
  7253 * new examples, including two proofs of the Church-Rosser theorem;
  7254 
  7255 * non-curried (1994) version of HOL is no longer distributed;
  7256 
  7257 
  7258 
  7259 New in Isabelle94-4
  7260 -------------------
  7261 
  7262 * greatly reduced space requirements;
  7263 
  7264 * theory files (.thy) no longer require \...\ escapes at line breaks;
  7265 
  7266 * searchable theorem database (see the section "Retrieving theorems" on
  7267 page 8 of the Reference Manual);
  7268 
  7269 * new examples, including Grabczewski's monumental case study of the
  7270 Axiom of Choice;
  7271 
  7272 * The previous version of HOL renamed to Old_HOL;
  7273 
  7274 * The new version of HOL (previously called CHOL) uses a curried syntax
  7275 for functions.  Application looks like f a b instead of f(a,b);
  7276 
  7277 * Mutually recursive inductive definitions finally work in HOL;
  7278 
  7279 * In ZF, pattern-matching on tuples is now available in all abstractions and
  7280 translates to the operator "split";
  7281 
  7282 
  7283 
  7284 New in Isabelle94-3
  7285 -------------------
  7286 
  7287 * new infix operator, addss, allowing the classical reasoner to
  7288 perform simplification at each step of its search.  Example:
  7289         fast_tac (cs addss ss)
  7290 
  7291 * a new logic, CHOL, the same as HOL, but with a curried syntax
  7292 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  7293 look like (a,b) instead of <a,b>;
  7294 
  7295 * PLEASE NOTE: CHOL will eventually replace HOL!
  7296 
  7297 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  7298 It translates to the operator "split".  A new theory of integers is available;
  7299 
  7300 * In ZF, integer numerals now denote two's-complement binary integers.
  7301 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  7302 
  7303 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  7304 of the Axiom of Choice;
  7305 
  7306 
  7307 
  7308 New in Isabelle94-2
  7309 -------------------
  7310 
  7311 * Significantly faster resolution;
  7312 
  7313 * the different sections in a .thy file can now be mixed and repeated
  7314 freely;
  7315 
  7316 * Database of theorems for FOL, HOL and ZF.  New
  7317 commands including qed, qed_goal and bind_thm store theorems in the database.
  7318 
  7319 * Simple database queries: return a named theorem (get_thm) or all theorems of
  7320 a given theory (thms_of), or find out what theory a theorem was proved in
  7321 (theory_of_thm);
  7322 
  7323 * Bugs fixed in the inductive definition and datatype packages;
  7324 
  7325 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  7326 and HOL_dup_cs obsolete;
  7327 
  7328 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  7329 have been removed;
  7330 
  7331 * Simpler definition of function space in ZF;
  7332 
  7333 * new results about cardinal and ordinal arithmetic in ZF;
  7334 
  7335 * 'subtype' facility in HOL for introducing new types as subsets of existing
  7336 types;
  7337 
  7338 :mode=text:wrap=hard:maxLineLen=72: