NEWS
author haftmann
Thu Jun 10 12:24:01 2010 +0200 (2010-06-10)
changeset 37389 09467cdfa198
parent 37387 3581483cca6c
child 37411 c88c44156083
child 37423 6167695009ad
permissions -rw-r--r--
qualified type "*"; qualified constants Pair, fst, snd, split
     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 
    29 New in Isabelle2009-2 (June 2010)
    30 ---------------------------------
    31 
    32 *** General ***
    33 
    34 * Authentic syntax for *all* logical entities (type classes, type
    35 constructors, term constants): provides simple and robust
    36 correspondence between formal entities and concrete syntax.  Within
    37 the parse tree / AST representations, "constants" are decorated by
    38 their category (class, type, const) and spelled out explicitly with
    39 their full internal name.
    40 
    41 Substantial INCOMPATIBILITY concerning low-level syntax declarations
    42 and translations (translation rules and translation functions in ML).
    43 Some hints on upgrading:
    44 
    45   - Many existing uses of 'syntax' and 'translations' can be replaced
    46     by more modern 'type_notation', 'notation' and 'abbreviation',
    47     which are independent of this issue.
    48 
    49   - 'translations' require markup within the AST; the term syntax
    50     provides the following special forms:
    51 
    52       CONST c   -- produces syntax version of constant c from context
    53       XCONST c  -- literally c, checked as constant from context
    54       c         -- literally c, if declared by 'syntax'
    55 
    56     Plain identifiers are treated as AST variables -- occasionally the
    57     system indicates accidental variables via the error "rhs contains
    58     extra variables".
    59 
    60     Type classes and type constructors are marked according to their
    61     concrete syntax.  Some old translations rules need to be written
    62     for the "type" category, using type constructor application
    63     instead of pseudo-term application of the default category
    64     "logic".
    65 
    66   - 'parse_translation' etc. in ML may use the following
    67     antiquotations:
    68 
    69       @{class_syntax c}   -- type class c within parse tree / AST
    70       @{term_syntax c}    -- type constructor c within parse tree / AST
    71       @{const_syntax c}   -- ML version of "CONST c" above
    72       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
    73 
    74   - Literal types within 'typed_print_translations', i.e. those *not*
    75     represented as pseudo-terms are represented verbatim.  Use @{class
    76     c} or @{type_name c} here instead of the above syntax
    77     antiquotations.
    78 
    79 Note that old non-authentic syntax was based on unqualified base
    80 names, so all of the above "constant" names would coincide.  Recall
    81 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
    82 diagnose syntax problems.
    83 
    84 * Type constructors admit general mixfix syntax, not just infix.
    85 
    86 * Concrete syntax may be attached to local entities without a proof
    87 body, too.  This works via regular mixfix annotations for 'fix',
    88 'def', 'obtain' etc. or via the explicit 'write' command, which is
    89 similar to the 'notation' command in theory specifications.
    90 
    91 * Discontinued unnamed infix syntax (legacy feature for many years) --
    92 need to specify constant name and syntax separately.  Internal ML
    93 datatype constructors have been renamed from InfixName to Infix etc.
    94 Minor INCOMPATIBILITY.
    95 
    96 * Schematic theorem statements need to be explicitly markup as such,
    97 via commands 'schematic_lemma', 'schematic_theorem',
    98 'schematic_corollary'.  Thus the relevance of the proof is made
    99 syntactically clear, which impacts performance in a parallel or
   100 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   101 
   102 * Use of cumulative prems via "!" in some proof methods has been
   103 discontinued (old legacy feature).
   104 
   105 * References 'trace_simp' and 'debug_simp' have been replaced by
   106 configuration options stored in the context. Enabling tracing (the
   107 case of debugging is similar) in proofs works via
   108 
   109   using [[trace_simp = true]]
   110 
   111 Tracing is then active for all invocations of the simplifier in
   112 subsequent goal refinement steps. Tracing may also still be enabled or
   113 disabled via the ProofGeneral settings menu.
   114 
   115 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   116 'hide_fact' replace the former 'hide' KIND command.  Minor
   117 INCOMPATIBILITY.
   118 
   119 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   120 more efficient than combinations with -q1 or -q2.
   121 
   122 
   123 *** Pure ***
   124 
   125 * Proofterms record type-class reasoning explicitly, using the
   126 "unconstrain" operation internally.  This eliminates all sort
   127 constraints from a theorem and proof, introducing explicit
   128 OFCLASS-premises.  On the proof term level, this operation is
   129 automatically applied at theorem boundaries, such that closed proofs
   130 are always free of sort constraints.  INCOMPATIBILITY for tools that
   131 inspect proof terms.
   132 
   133 * Local theory specifications may depend on extra type variables that
   134 are not present in the result type -- arguments TYPE('a) :: 'a itself
   135 are added internally.  For example:
   136 
   137   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   138 
   139 * Predicates of locales introduced by classes carry a mandatory
   140 "class" prefix.  INCOMPATIBILITY.
   141 
   142 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   143 
   144 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   145 'class' instead.
   146 
   147 * Command 'code_reflect' allows to incorporate generated ML code into
   148 runtime environment; replaces immature code_datatype antiquotation.
   149 INCOMPATIBILITY.
   150 
   151 * Code generator: simple concept for abstract datatypes obeying
   152 invariants.
   153 
   154 * Code generator: details of internal data cache have no impact on the
   155 user space functionality any longer.
   156 
   157 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   158 subgoals.  This is more appropriate for interpretations with 'where'.
   159 INCOMPATIBILITY.
   160 
   161 * Command 'example_proof' opens an empty proof body.  This allows to
   162 experiment with Isar, without producing any persistent result.
   163 
   164 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   165 within a local theory context, with explicit checking of the
   166 constructors involved (in contrast to the raw 'syntax' versions).
   167 
   168 * Commands 'types' and 'typedecl' now work within a local theory
   169 context -- without introducing dependencies on parameters or
   170 assumptions, which is not possible in Isabelle/Pure.
   171 
   172 * Command 'defaultsort' has been renamed to 'default_sort', it works
   173 within a local theory context.  Minor INCOMPATIBILITY.
   174 
   175 
   176 *** HOL ***
   177 
   178 * Command 'typedef' now works within a local theory context -- without
   179 introducing dependencies on parameters or assumptions, which is not
   180 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   181 contain multiple interpretations of local typedefs (with different
   182 non-emptiness proofs), even in a global theory context.
   183 
   184 * New package for quotient types.  Commands 'quotient_type' and
   185 'quotient_definition' may be used for defining types and constants by
   186 quotient constructions.  An example is the type of integers created by
   187 quotienting pairs of natural numbers:
   188   
   189   fun
   190     intrel :: "(nat * nat) => (nat * nat) => bool" 
   191   where
   192     "intrel (x, y) (u, v) = (x + v = u + y)"
   193 
   194   quotient_type int = "nat × nat" / intrel
   195     by (auto simp add: equivp_def expand_fun_eq)
   196   
   197   quotient_definition
   198     "0::int" is "(0::nat, 0::nat)"
   199 
   200 The method "lifting" can be used to lift of theorems from the
   201 underlying "raw" type to the quotient type.  The example
   202 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   203 construction and provides a reasoning infrastructure for finite sets.
   204 
   205 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   206 clash with new theory Quotient in Main HOL.
   207 
   208 * Moved the SMT binding into the main HOL session, eliminating
   209 separate HOL-SMT session.
   210 
   211 * List membership infix mem operation is only an input abbreviation.
   212 INCOMPATIBILITY.
   213 
   214 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   215 for future developements; former Library/Word.thy is still present in
   216 the AFP entry RSAPPS.
   217 
   218 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   219 longer shadowed.  INCOMPATIBILITY.
   220 
   221 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   222 INCOMPATIBILITY.
   223 
   224 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   225 INCOMPATIBILITY.
   226 
   227 * Dropped normalizing_semiring etc; use the facts in semiring classes
   228 instead.  INCOMPATIBILITY.
   229 
   230 * Dropped several real-specific versions of lemmas about floor and
   231 ceiling; use the generic lemmas from theory "Archimedean_Field"
   232 instead.  INCOMPATIBILITY.
   233 
   234   floor_number_of_eq         ~> floor_number_of
   235   le_floor_eq_number_of      ~> number_of_le_floor
   236   le_floor_eq_zero           ~> zero_le_floor
   237   le_floor_eq_one            ~> one_le_floor
   238   floor_less_eq_number_of    ~> floor_less_number_of
   239   floor_less_eq_zero         ~> floor_less_zero
   240   floor_less_eq_one          ~> floor_less_one
   241   less_floor_eq_number_of    ~> number_of_less_floor
   242   less_floor_eq_zero         ~> zero_less_floor
   243   less_floor_eq_one          ~> one_less_floor
   244   floor_le_eq_number_of      ~> floor_le_number_of
   245   floor_le_eq_zero           ~> floor_le_zero
   246   floor_le_eq_one            ~> floor_le_one
   247   floor_subtract_number_of   ~> floor_diff_number_of
   248   floor_subtract_one         ~> floor_diff_one
   249   ceiling_number_of_eq       ~> ceiling_number_of
   250   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   251   ceiling_le_zero_eq         ~> ceiling_le_zero
   252   ceiling_le_eq_one          ~> ceiling_le_one
   253   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   254   less_ceiling_eq_zero       ~> zero_less_ceiling
   255   less_ceiling_eq_one        ~> one_less_ceiling
   256   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   257   ceiling_less_eq_zero       ~> ceiling_less_zero
   258   ceiling_less_eq_one        ~> ceiling_less_one
   259   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   260   le_ceiling_eq_zero         ~> zero_le_ceiling
   261   le_ceiling_eq_one          ~> one_le_ceiling
   262   ceiling_subtract_number_of ~> ceiling_diff_number_of
   263   ceiling_subtract_one       ~> ceiling_diff_one
   264 
   265 * Theory "Finite_Set": various folding_XXX locales facilitate the
   266 application of the various fold combinators on finite sets.
   267 
   268 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   269 provides abstract red-black tree type which is backed by "RBT_Impl" as
   270 implementation.  INCOMPATIBILTY.
   271 
   272 * Theory Library/Coinductive_List has been removed -- superseded by
   273 AFP/thys/Coinductive.
   274 
   275 * Theory PReal, including the type "preal" and related operations, has
   276 been removed.  INCOMPATIBILITY.
   277 
   278 * Split off theory "Big_Operators" containing setsum, setprod,
   279 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   280 
   281 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   282 "Int" etc.  INCOMPATIBILITY.
   283 
   284 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   285 
   286 * New set of rules "ac_simps" provides combined assoc / commute
   287 rewrites for all interpretations of the appropriate generic locales.
   288 
   289 * Renamed theory "OrderedGroup" to "Groups" and split theory
   290 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   291 appropriate and more consistent names suitable for name prefixes
   292 within the HOL theories.  INCOMPATIBILITY.
   293 
   294 * Some generic constants have been put to appropriate theories:
   295   - less_eq, less: Orderings
   296   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   297   - inverse, divide: Rings
   298 INCOMPATIBILITY.
   299 
   300 * More consistent naming of type classes involving orderings (and
   301 lattices):
   302 
   303     lower_semilattice                   ~> semilattice_inf
   304     upper_semilattice                   ~> semilattice_sup
   305 
   306     dense_linear_order                  ~> dense_linorder
   307 
   308     pordered_ab_group_add               ~> ordered_ab_group_add
   309     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   310     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   311     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   312     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   313     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   314     pordered_cancel_semiring            ~> ordered_cancel_semiring
   315     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   316     pordered_comm_ring                  ~> ordered_comm_ring
   317     pordered_comm_semiring              ~> ordered_comm_semiring
   318     pordered_ring                       ~> ordered_ring
   319     pordered_ring_abs                   ~> ordered_ring_abs
   320     pordered_semiring                   ~> ordered_semiring
   321 
   322     ordered_ab_group_add                ~> linordered_ab_group_add
   323     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   324     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   325     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   326     ordered_field                       ~> linordered_field
   327     ordered_field_no_lb                 ~> linordered_field_no_lb
   328     ordered_field_no_ub                 ~> linordered_field_no_ub
   329     ordered_field_dense_linear_order    ~> dense_linordered_field
   330     ordered_idom                        ~> linordered_idom
   331     ordered_ring                        ~> linordered_ring
   332     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   333     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   334     ordered_ring_strict                 ~> linordered_ring_strict
   335     ordered_semidom                     ~> linordered_semidom
   336     ordered_semiring                    ~> linordered_semiring
   337     ordered_semiring_1                  ~> linordered_semiring_1
   338     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   339     ordered_semiring_strict             ~> linordered_semiring_strict
   340 
   341   The following slightly odd type classes have been moved to a
   342   separate theory Library/Lattice_Algebras:
   343 
   344     lordered_ab_group_add               ~> lattice_ab_group_add
   345     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   346     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   347     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   348     lordered_ring                       ~> lattice_ring
   349 
   350 INCOMPATIBILITY.
   351 
   352 * Refined field classes:
   353   - classes division_ring_inverse_zero, field_inverse_zero,
   354     linordered_field_inverse_zero include rule inverse 0 = 0 --
   355     subsumes former division_by_zero class;
   356   - numerous lemmas have been ported from field to division_ring.
   357 INCOMPATIBILITY.
   358 
   359 * Refined algebra theorem collections:
   360   - dropped theorem group group_simps, use algebra_simps instead;
   361   - dropped theorem group ring_simps, use field_simps instead;
   362   - proper theorem collection field_simps subsumes former theorem
   363     groups field_eq_simps and field_simps;
   364   - dropped lemma eq_minus_self_iff which is a duplicate for
   365     equal_neg_zero.
   366 INCOMPATIBILITY.
   367 
   368 * Theory Finite_Set and List: some lemmas have been generalized from
   369 sets to lattices:
   370 
   371   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   372   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   373   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   374   union_Union_fold_union        ~> sup_Sup_fold_sup
   375   Inter_fold_inter              ~> Inf_fold_inf
   376   Union_fold_union              ~> Sup_fold_sup
   377   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   378   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   379   INTER_fold_inter              ~> INFI_fold_inf
   380   UNION_fold_union              ~> SUPR_fold_sup
   381 
   382 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   383 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   384 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   385 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   386 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   387 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   388 
   389 * Reorganized theory Multiset: swapped notation of pointwise and
   390 multiset order:
   391 
   392   - pointwise ordering is instance of class order with standard syntax
   393     <= and <;
   394   - multiset ordering has syntax <=# and <#; partial order properties
   395     are provided by means of interpretation with prefix
   396     multiset_order;
   397   - less duplication, less historical organization of sections,
   398     conversion from associations lists to multisets, rudimentary code
   399     generation;
   400   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   401     if needed.
   402 
   403 Renamed:
   404 
   405   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   406   multi_count_ext  ~>  multiset_ext
   407   diff_union_inverse2  ~>  diff_union_cancelR
   408 
   409 INCOMPATIBILITY.
   410 
   411 * Theory Permutation: replaced local "remove" by List.remove1.
   412 
   413 * Code generation: ML and OCaml code is decorated with signatures.
   414 
   415 * Theory List: added transpose.
   416 
   417 * Library/Nat_Bijection.thy is a collection of bijective functions
   418 between nat and other types, which supersedes the older libraries
   419 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   420 
   421   Constants:
   422   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   423   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   424   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   425   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   426   Countable.pair_encode           ~> prod_encode
   427   NatIso.prod2nat                 ~> prod_encode
   428   NatIso.nat2prod                 ~> prod_decode
   429   NatIso.sum2nat                  ~> sum_encode
   430   NatIso.nat2sum                  ~> sum_decode
   431   NatIso.list2nat                 ~> list_encode
   432   NatIso.nat2list                 ~> list_decode
   433   NatIso.set2nat                  ~> set_encode
   434   NatIso.nat2set                  ~> set_decode
   435 
   436   Lemmas:
   437   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   438   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   439   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   440   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   441   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   442   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   443   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   444   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   445   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   446   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   447   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   448   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   449   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   450 
   451 * Sledgehammer:
   452   - Renamed ATP commands:
   453     atp_info     ~> sledgehammer running_atps
   454     atp_kill     ~> sledgehammer kill_atps
   455     atp_messages ~> sledgehammer messages
   456     atp_minimize ~> sledgehammer minimize
   457     print_atps   ~> sledgehammer available_atps
   458     INCOMPATIBILITY.
   459   - Added user's manual ("isabelle doc sledgehammer").
   460   - Added option syntax and "sledgehammer_params" to customize
   461     Sledgehammer's behavior.  See the manual for details.
   462   - Modified the Isar proof reconstruction code so that it produces
   463     direct proofs rather than proofs by contradiction.  (This feature
   464     is still experimental.)
   465   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   466     full-typed mode.
   467   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   468 
   469 * Nitpick:
   470   - Added and implemented "binary_ints" and "bits" options.
   471   - Added "std" option and implemented support for nonstandard models.
   472   - Added and implemented "finitize" option to improve the precision
   473     of infinite datatypes based on a monotonicity analysis.
   474   - Added support for quotient types.
   475   - Added support for "specification" and "ax_specification"
   476     constructs.
   477   - Added support for local definitions (for "function" and
   478     "termination" proofs).
   479   - Added support for term postprocessors.
   480   - Optimized "Multiset.multiset" and "FinFun.finfun".
   481   - Improved efficiency of "destroy_constrs" optimization.
   482   - Fixed soundness bugs related to "destroy_constrs" optimization and
   483     record getters.
   484   - Fixed soundness bug related to higher-order constructors.
   485   - Fixed soundness bug when "full_descrs" is enabled.
   486   - Improved precision of set constructs.
   487   - Added "atoms" option.
   488   - Added cache to speed up repeated Kodkod invocations on the same
   489     problems.
   490   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   491     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   492     "SAT4J_Light".  INCOMPATIBILITY.
   493   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   494     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   495   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   496 
   497 
   498 *** HOLCF ***
   499 
   500 * Variable names in lemmas generated by the domain package have
   501 changed; the naming scheme is now consistent with the HOL datatype
   502 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   503 
   504 * The domain package no longer defines the function "foo_copy" for
   505 recursive domain "foo".  The reach lemma is now stated directly in
   506 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   507 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   508 
   509 * Most definedness lemmas generated by the domain package (previously
   510 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   511 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   512 Proofs that used definedness lemmas as intro rules may break,
   513 potential INCOMPATIBILITY.
   514 
   515 * Induction and casedist rules generated by the domain package now
   516 declare proper case_names (one called "bottom", and one named for each
   517 constructor).  INCOMPATIBILITY.
   518 
   519 * For mutually-recursive domains, separate "reach" and "take_lemma"
   520 rules are generated for each domain, INCOMPATIBILITY.
   521 
   522   foo_bar.reach       ~> foo.reach  bar.reach
   523   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   524 
   525 * Some lemmas generated by the domain package have been renamed for
   526 consistency with the datatype package, INCOMPATIBILITY.
   527 
   528   foo.ind        ~> foo.induct
   529   foo.finite_ind ~> foo.finite_induct
   530   foo.coind      ~> foo.coinduct
   531   foo.casedist   ~> foo.exhaust
   532   foo.exhaust    ~> foo.nchotomy
   533 
   534 * For consistency with other definition packages, the fixrec package
   535 now generates qualified theorem names, INCOMPATIBILITY.
   536 
   537   foo_simps  ~> foo.simps
   538   foo_unfold ~> foo.unfold
   539   foo_induct ~> foo.induct
   540 
   541 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   542 method and internal fixrec proofs now use the default simpset instead.
   543 INCOMPATIBILITY.
   544 
   545 * The "contlub" predicate has been removed.  Proof scripts should use
   546 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   547 
   548 * The "admw" predicate has been removed, INCOMPATIBILITY.
   549 
   550 * The constants cpair, cfst, and csnd have been removed in favor of
   551 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   552 
   553 
   554 *** ML ***
   555 
   556 * Antiquotations for basic formal entities:
   557 
   558     @{class NAME}         -- type class
   559     @{class_syntax NAME}  -- syntax representation of the above
   560 
   561     @{type_name NAME}     -- logical type
   562     @{type_abbrev NAME}   -- type abbreviation
   563     @{nonterminal NAME}   -- type of concrete syntactic category
   564     @{type_syntax NAME}   -- syntax representation of any of the above
   565 
   566     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   567     @{const_abbrev NAME}  -- abbreviated constant
   568     @{const_syntax NAME}  -- syntax representation of any of the above
   569 
   570 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   571 syntax constant (cf. 'syntax' command).
   572 
   573 * Antiquotation @{make_string} inlines a function to print arbitrary
   574 values similar to the ML toplevel.  The result is compiler dependent
   575 and may fall back on "?" in certain situations.
   576 
   577 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   578 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   579 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   580 not work with the asynchronous Isar document model.
   581 
   582 * Configuration options now admit dynamic default values, depending on
   583 the context or even global references.
   584 
   585 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   586 uses an efficient external library if available (for Poly/ML).
   587 
   588 * Renamed some important ML structures, while keeping the old names
   589 for some time as aliases within the structure Legacy:
   590 
   591   OuterKeyword  ~>  Keyword
   592   OuterLex      ~>  Token
   593   OuterParse    ~>  Parse
   594   OuterSyntax   ~>  Outer_Syntax
   595   PrintMode     ~>  Print_Mode
   596   SpecParse     ~>  Parse_Spec
   597   ThyInfo       ~>  Thy_Info
   598   ThyLoad       ~>  Thy_Load
   599   ThyOutput     ~>  Thy_Output
   600   TypeInfer     ~>  Type_Infer
   601 
   602 Note that "open Legacy" simplifies porting of sources, but forgetting
   603 to remove it again will complicate porting again in the future.
   604 
   605 * Most operations that refer to a global context are named
   606 accordingly, e.g. Simplifier.global_context or
   607 ProofContext.init_global.  There are some situations where a global
   608 context actually works, but under normal circumstances one needs to
   609 pass the proper local context through the code!
   610 
   611 * Discontinued old TheoryDataFun with its copy/init operation -- data
   612 needs to be pure.  Functor Theory_Data_PP retains the traditional
   613 Pretty.pp argument to merge, which is absent in the standard
   614 Theory_Data version.
   615 
   616 * Sorts.certify_sort and derived "cert" operations for types and terms
   617 no longer minimize sorts.  Thus certification at the boundary of the
   618 inference kernel becomes invariant under addition of class relations,
   619 which is an important monotonicity principle.  Sorts are now minimized
   620 in the syntax layer only, at the boundary between the end-user and the
   621 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   622 explicitly in rare situations.
   623 
   624 * Renamed old-style Drule.standard to Drule.export_without_context, to
   625 emphasize that this is in no way a standard operation.
   626 INCOMPATIBILITY.
   627 
   628 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   629 usual for resolution.  Rare INCOMPATIBILITY.
   630 
   631 * Renamed varify/unvarify operations to varify_global/unvarify_global
   632 to emphasize that these only work in a global situation (which is
   633 quite rare).
   634 
   635 * Curried take and drop in library.ML; negative length is interpreted
   636 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   637 
   638 * Proof terms: type substitutions on proof constants now use canonical
   639 order of type variables.  INCOMPATIBILITY for tools working with proof
   640 terms.
   641 
   642 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   643 may no longer carry premises.  User-level specifications are
   644 transformed accordingly by Thm.add_axiom/add_def.
   645 
   646 
   647 *** System ***
   648 
   649 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   650 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   651 proof terms are enabled unconditionally in the new HOL-Proofs image.
   652 
   653 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   654 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   655 respectively.
   656 
   657 * Old lib/scripts/polyml-platform is superseded by the
   658 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   659 variant, even on a 64 bit machine.  The following example setting
   660 prefers 64 bit if available:
   661 
   662   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   663 
   664 * The preliminary Isabelle/jEdit application demonstrates the emerging
   665 Isabelle/Scala layer for advanced prover interaction and integration.
   666 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   667 component.
   668 
   669 
   670 
   671 New in Isabelle2009-1 (December 2009)
   672 -------------------------------------
   673 
   674 *** General ***
   675 
   676 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   677 one backslash should be used, even in ML sources.
   678 
   679 
   680 *** Pure ***
   681 
   682 * Locale interpretation propagates mixins along the locale hierarchy.
   683 The currently only available mixins are the equations used to map
   684 local definitions to terms of the target domain of an interpretation.
   685 
   686 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   687 loc" to print all interpretations of locale "loc" in the theory.
   688 Interpretations in proofs are not shown.
   689 
   690 * Thoroughly revised locales tutorial.  New section on conditional
   691 interpretation.
   692 
   693 * On instantiation of classes, remaining undefined class parameters
   694 are formally declared.  INCOMPATIBILITY.
   695 
   696 
   697 *** Document preparation ***
   698 
   699 * New generalized style concept for printing terms: @{foo (style) ...}
   700 instead of @{foo_style style ...}  (old form is still retained for
   701 backward compatibility).  Styles can be also applied for
   702 antiquotations prop, term_type and typeof.
   703 
   704 
   705 *** HOL ***
   706 
   707 * New proof method "smt" for a combination of first-order logic with
   708 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   709 fixed-size bitvectors; there is also basic support for higher-order
   710 features (esp. lambda abstractions).  It is an incomplete decision
   711 procedure based on external SMT solvers using the oracle mechanism;
   712 for the SMT solver Z3, this method is proof-producing.  Certificates
   713 are provided to avoid calling the external solvers solely for
   714 re-checking proofs.  Due to a remote SMT service there is no need for
   715 installing SMT solvers locally.  See src/HOL/SMT.
   716 
   717 * New commands to load and prove verification conditions generated by
   718 the Boogie program verifier or derived systems (e.g. the Verifying C
   719 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   720 
   721 * New counterexample generator tool 'nitpick' based on the Kodkod
   722 relational model finder.  See src/HOL/Tools/Nitpick and
   723 src/HOL/Nitpick_Examples.
   724 
   725 * New commands 'code_pred' and 'values' to invoke the predicate
   726 compiler and to enumerate values of inductive predicates.
   727 
   728 * A tabled implementation of the reflexive transitive closure.
   729 
   730 * New implementation of quickcheck uses generic code generator;
   731 default generators are provided for all suitable HOL types, records
   732 and datatypes.  Old quickcheck can be re-activated importing theory
   733 Library/SML_Quickcheck.
   734 
   735 * New testing tool Mirabelle for automated proof tools.  Applies
   736 several tools and tactics like sledgehammer, metis, or quickcheck, to
   737 every proof step in a theory.  To be used in batch mode via the
   738 "mirabelle" utility.
   739 
   740 * New proof method "sos" (sum of squares) for nonlinear real
   741 arithmetic (originally due to John Harison). It requires theory
   742 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   743 works well in practice on quantifier-free real arithmetic with +, -,
   744 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   745 inequalities between polynomials.  It makes use of external
   746 semidefinite programming solvers.  Method "sos" generates a
   747 certificate that can be pasted into the proof thus avoiding the need
   748 to call an external tool every time the proof is checked.  See
   749 src/HOL/Library/Sum_Of_Squares.
   750 
   751 * New method "linarith" invokes existing linear arithmetic decision
   752 procedure only.
   753 
   754 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   755 
   756 * New Sledgehammer option "Full Types" in Proof General settings menu.
   757 Causes full type information to be output to the ATPs.  This slows
   758 ATPs down considerably but eliminates a source of unsound "proofs"
   759 that fail later.
   760 
   761 * New method "metisFT": A version of metis that uses full type
   762 information in order to avoid failures of proof reconstruction.
   763 
   764 * New evaluator "approximate" approximates an real valued term using
   765 the same method as the approximation method.
   766 
   767 * Method "approximate" now supports arithmetic expressions as
   768 boundaries of intervals and implements interval splitting and Taylor
   769 series expansion.
   770 
   771 * ML antiquotation @{code_datatype} inserts definition of a datatype
   772 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   773 
   774 * New theory SupInf of the supremum and infimum operators for sets of
   775 reals.
   776 
   777 * New theory Probability, which contains a development of measure
   778 theory, eventually leading to Lebesgue integration and probability.
   779 
   780 * Extended Multivariate Analysis to include derivation and Brouwer's
   781 fixpoint theorem.
   782 
   783 * Reorganization of number theory, INCOMPATIBILITY:
   784   - new number theory development for nat and int, in theories Divides
   785     and GCD as well as in new session Number_Theory
   786   - some constants and facts now suffixed with _nat and _int
   787     accordingly
   788   - former session NumberTheory now named Old_Number_Theory, including
   789     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   790   - moved theory Pocklington from src/HOL/Library to
   791     src/HOL/Old_Number_Theory
   792 
   793 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   794 lcm of finite and infinite sets. It is shown that they form a complete
   795 lattice.
   796 
   797 * Class semiring_div requires superclass no_zero_divisors and proof of
   798 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   799 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   800 generalized to class semiring_div, subsuming former theorems
   801 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   802 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   803 INCOMPATIBILITY.
   804 
   805 * Refinements to lattice classes and sets:
   806   - less default intro/elim rules in locale variant, more default
   807     intro/elim rules in class variant: more uniformity
   808   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   809     le_inf_iff
   810   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   811     sup_aci)
   812   - renamed ACI to inf_sup_aci
   813   - new class "boolean_algebra"
   814   - class "complete_lattice" moved to separate theory
   815     "Complete_Lattice"; corresponding constants (and abbreviations)
   816     renamed and with authentic syntax:
   817     Set.Inf ~>    Complete_Lattice.Inf
   818     Set.Sup ~>    Complete_Lattice.Sup
   819     Set.INFI ~>   Complete_Lattice.INFI
   820     Set.SUPR ~>   Complete_Lattice.SUPR
   821     Set.Inter ~>  Complete_Lattice.Inter
   822     Set.Union ~>  Complete_Lattice.Union
   823     Set.INTER ~>  Complete_Lattice.INTER
   824     Set.UNION ~>  Complete_Lattice.UNION
   825   - authentic syntax for
   826     Set.Pow
   827     Set.image
   828   - mere abbreviations:
   829     Set.empty               (for bot)
   830     Set.UNIV                (for top)
   831     Set.inter               (for inf, formerly Set.Int)
   832     Set.union               (for sup, formerly Set.Un)
   833     Complete_Lattice.Inter  (for Inf)
   834     Complete_Lattice.Union  (for Sup)
   835     Complete_Lattice.INTER  (for INFI)
   836     Complete_Lattice.UNION  (for SUPR)
   837   - object-logic definitions as far as appropriate
   838 
   839 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   840 Un_subset_iff are explicitly deleted as default simp rules; then also
   841 their lattice counterparts le_inf_iff and le_sup_iff have to be
   842 deleted to achieve the desired effect.
   843 
   844 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   845 rules by default any longer; the same applies to min_max.inf_absorb1
   846 etc.  INCOMPATIBILITY.
   847 
   848 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   849 pred_set_conv by default.  INCOMPATIBILITY.
   850 
   851 * Power operations on relations and functions are now one dedicated
   852 constant "compow" with infix syntax "^^".  Power operation on
   853 multiplicative monoids retains syntax "^" and is now defined generic
   854 in class power.  INCOMPATIBILITY.
   855 
   856 * Relation composition "R O S" now has a more standard argument order:
   857 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   858 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   859 break, since the O_assoc rule was not rewritten like this.  Fix using
   860 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   861 
   862 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   863 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   864 INCOMPATIBILITY.
   865 
   866 * Most rules produced by inductive and datatype package have mandatory
   867 prefixes.  INCOMPATIBILITY.
   868 
   869 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   870 the attribute of the same name.  Each of the theorems in the list
   871 DERIV_intros assumes composition with an additional function and
   872 matches a variable to the derivative, which has to be solved by the
   873 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   874 of most elementary terms.  Former Maclauren.DERIV_tac and
   875 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   876 INCOMPATIBILITY.
   877 
   878 * Code generator attributes follow the usual underscore convention:
   879     code_unfold     replaces    code unfold
   880     code_post       replaces    code post
   881     etc.
   882   INCOMPATIBILITY.
   883 
   884 * Renamed methods:
   885     sizechange -> size_change
   886     induct_scheme -> induction_schema
   887   INCOMPATIBILITY.
   888 
   889 * Discontinued abbreviation "arbitrary" of constant "undefined".
   890 INCOMPATIBILITY, use "undefined" directly.
   891 
   892 * Renamed theorems:
   893     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   894     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   895     Suc_plus1 -> Suc_eq_plus1
   896     *anti_sym -> *antisym*
   897     vector_less_eq_def -> vector_le_def
   898   INCOMPATIBILITY.
   899 
   900 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   901 INCOMPATIBILITY.
   902 
   903 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   904 INCOMPATIBILITY.
   905 
   906 
   907 *** HOLCF ***
   908 
   909 * Theory Representable defines a class "rep" of domains that are
   910 representable (via an ep-pair) in the universal domain type "udom".
   911 Instances are provided for all type constructors defined in HOLCF.
   912 
   913 * The 'new_domain' command is a purely definitional version of the
   914 domain package, for representable domains.  Syntax is identical to the
   915 old domain package.  The 'new_domain' package also supports indirect
   916 recursion using previously-defined type constructors.  See
   917 src/HOLCF/ex/New_Domain.thy for examples.
   918 
   919 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   920 on the left-hand side of an equation, and then performs
   921 simplification.  Rewriting is done using rules declared with the
   922 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   923 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   924 
   925 * The pattern-match compiler in 'fixrec' can now handle constructors
   926 with HOL function types.  Pattern-match combinators for the Pair
   927 constructor are pre-configured.
   928 
   929 * The 'fixrec' package now produces better fixed-point induction rules
   930 for mutually-recursive definitions:  Induction rules have conclusions
   931 of the form "P foo bar" instead of "P <foo, bar>".
   932 
   933 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   934 been renamed to "below".  The name "below" now replaces "less" in many
   935 theorem names.  (Legacy theorem names using "less" are still supported
   936 as well.)
   937 
   938 * The 'fixrec' package now supports "bottom patterns".  Bottom
   939 patterns can be used to generate strictness rules, or to make
   940 functions more strict (much like the bang-patterns supported by the
   941 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   942 examples.
   943 
   944 
   945 *** ML ***
   946 
   947 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   948 errors and run-time exceptions, including detailed source positions.
   949 
   950 * Structure Name_Space (formerly NameSpace) now manages uniquely
   951 identified entries, with some additional information such as source
   952 position, logical grouping etc.
   953 
   954 * Theory and context data is now introduced by the simplified and
   955 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   956 to be pure, but the old TheoryDataFun for mutable data (with explicit
   957 copy operation) is still available for some time.
   958 
   959 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   960 provides a high-level programming interface to synchronized state
   961 variables with atomic update.  This works via pure function
   962 application within a critical section -- its runtime should be as
   963 short as possible; beware of deadlocks if critical code is nested,
   964 either directly or indirectly via other synchronized variables!
   965 
   966 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   967 wraps raw ML references, explicitly indicating their non-thread-safe
   968 behaviour.  The Isar toplevel keeps this structure open, to
   969 accommodate Proof General as well as quick and dirty interactive
   970 experiments with references.
   971 
   972 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   973 parallel tactical reasoning.
   974 
   975 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   976 are similar to SUBPROOF, but are slightly more flexible: only the
   977 specified parts of the subgoal are imported into the context, and the
   978 body tactic may introduce new subgoals and schematic variables.
   979 
   980 * Old tactical METAHYPS, which does not observe the proof context, has
   981 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   982 or Subgoal.FOCUS etc.
   983 
   984 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   985 functors have their own ML name space there is no point to mark them
   986 separately.)  Minor INCOMPATIBILITY.
   987 
   988 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   989 
   990 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   991 INCOMPATIBILITY.
   992 
   993 * Operations of structure Skip_Proof no longer require quick_and_dirty
   994 mode, which avoids critical setmp.
   995 
   996 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   997 combinators for "args".  INCOMPATIBILITY, need to use simplified
   998 Attrib/Method.setup introduced in Isabelle2009.
   999 
  1000 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1001 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1002 last resort.  INCOMPATIBILITY.
  1003 
  1004 * Display.pretty_thm now requires a proper context (cf. former
  1005 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1006 or even Display.pretty_thm_without_context as last resort.
  1007 INCOMPATIBILITY.
  1008 
  1009 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1010 Syntax.pretty_typ/term directly, preferably with proper context
  1011 instead of global theory.
  1012 
  1013 
  1014 *** System ***
  1015 
  1016 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1017 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1018 usedir option -q.
  1019 
  1020 * Support for additional "Isabelle components" via etc/components, see
  1021 also the system manual.
  1022 
  1023 * The isabelle makeall tool now operates on all components with
  1024 IsaMakefile, not just hardwired "logics".
  1025 
  1026 * Removed "compress" option from isabelle-process and isabelle usedir;
  1027 this is always enabled.
  1028 
  1029 * Discontinued support for Poly/ML 4.x versions.
  1030 
  1031 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1032 on a given logic image.  This requires the lighttpd webserver and is
  1033 currently supported on Linux only.
  1034 
  1035 
  1036 
  1037 New in Isabelle2009 (April 2009)
  1038 --------------------------------
  1039 
  1040 *** General ***
  1041 
  1042 * Simplified main Isabelle executables, with less surprises on
  1043 case-insensitive file-systems (such as Mac OS).
  1044 
  1045   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1046     "isatool."
  1047 
  1048   - The former "isabelle" alias for "isabelle-process" has been
  1049     removed (should rarely occur to regular users).
  1050 
  1051   - The former "isabelle-interface" and its alias "Isabelle" have been
  1052     removed (interfaces are now regular Isabelle tools).
  1053 
  1054 Within scripts and make files, the Isabelle environment variables
  1055 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1056 respectively.  (The latter are still available as legacy feature.)
  1057 
  1058 The old isabelle-interface wrapper could react in confusing ways if
  1059 the interface was uninstalled or changed otherwise.  Individual
  1060 interface tool configuration is now more explicit, see also the
  1061 Isabelle system manual.  In particular, Proof General is now available
  1062 via "isabelle emacs".
  1063 
  1064 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1065 purge installed copies of Isabelle executables and re-run "isabelle
  1066 install -p ...", or use symlinks.
  1067 
  1068 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1069 old ~/isabelle, which was slightly non-standard and apt to cause
  1070 surprises on case-insensitive file-systems (such as Mac OS).
  1071 
  1072 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1073 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1074 care is required when using older releases of Isabelle.  Note that
  1075 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1076 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1077 
  1078 * Proofs of fully specified statements are run in parallel on
  1079 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1080 a regular 4-core machine, if the initial heap space is made reasonably
  1081 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1082 
  1083 * The main reference manuals ("isar-ref", "implementation", and
  1084 "system") have been updated and extended.  Formally checked references
  1085 as hyperlinks are now available uniformly.
  1086 
  1087 
  1088 *** Pure ***
  1089 
  1090 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1091 respects.  The most important changes are listed below.  See the
  1092 Tutorial on Locales ("locales" manual) for details.
  1093 
  1094 - In locale expressions, instantiation replaces renaming.  Parameters
  1095 must be declared in a for clause.  To aid compatibility with previous
  1096 parameter inheritance, in locale declarations, parameters that are not
  1097 'touched' (instantiation position "_" or omitted) are implicitly added
  1098 with their syntax at the beginning of the for clause.
  1099 
  1100 - Syntax from abbreviations and definitions in locales is available in
  1101 locale expressions and context elements.  The latter is particularly
  1102 useful in locale declarations.
  1103 
  1104 - More flexible mechanisms to qualify names generated by locale
  1105 expressions.  Qualifiers (prefixes) may be specified in locale
  1106 expressions, and can be marked as mandatory (syntax: "name!:") or
  1107 optional (syntax "name?:").  The default depends for plain "name:"
  1108 depends on the situation where a locale expression is used: in
  1109 commands 'locale' and 'sublocale' prefixes are optional, in
  1110 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1111 implicit qualifiers derived from the parameter names of a locale are
  1112 no longer generated.
  1113 
  1114 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1115 instantiation clause in "interpretation" and "interpret" (square
  1116 brackets) is no longer available.  Use locale expressions.
  1117 
  1118 - When converting proof scripts, mandatory qualifiers in
  1119 'interpretation' and 'interpret' should be retained by default, even
  1120 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1121 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1122 in locale expressions range over a single locale instance only.
  1123 
  1124 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1125 In existing theorem specifications replace the includes element by the
  1126 respective context elements of the included locale, omitting those
  1127 that are already present in the theorem specification.  Multiple
  1128 assume elements of a locale should be replaced by a single one
  1129 involving the locale predicate.  In the proof body, declarations (most
  1130 notably theorems) may be regained by interpreting the respective
  1131 locales in the proof context as required (command "interpret").
  1132 
  1133 If using "includes" in replacement of a target solely because the
  1134 parameter types in the theorem are not as general as in the target,
  1135 consider declaring a new locale with additional type constraints on
  1136 the parameters (context element "constrains").
  1137 
  1138 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1139 
  1140 - Locale interpretation commands no longer attempt to simplify goal.
  1141 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1142 methods intro_locales and unfold_locales to clarify.
  1143 
  1144 - Locale interpretation commands no longer accept interpretation
  1145 attributes.  INCOMPATIBILITY.
  1146 
  1147 * Class declaration: so-called "base sort" must not be given in import
  1148 list any longer, but is inferred from the specification.  Particularly
  1149 in HOL, write
  1150 
  1151     class foo = ...
  1152 
  1153 instead of
  1154 
  1155     class foo = type + ...
  1156 
  1157 * Class target: global versions of theorems stemming do not carry a
  1158 parameter prefix any longer.  INCOMPATIBILITY.
  1159 
  1160 * Class 'instance' command no longer accepts attached definitions.
  1161 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1162 
  1163 * Recovered hiding of consts, which was accidentally broken in
  1164 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1165 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1166 
  1167 * Slightly more coherent Pure syntax, with updated documentation in
  1168 isar-ref manual.  Removed locales meta_term_syntax and
  1169 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1170 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1171 directly in regular applications.
  1172 
  1173 * There is a new syntactic category "float_const" for signed decimal
  1174 fractions (e.g. 123.45 or -123.45).
  1175 
  1176 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1177 interface with 'setup' command instead.
  1178 
  1179 * Command 'local_setup' is similar to 'setup', but operates on a local
  1180 theory context.
  1181 
  1182 * The 'axiomatization' command now only works within a global theory
  1183 context.  INCOMPATIBILITY.
  1184 
  1185 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1186 hypotheses.  Sorts required in the course of reasoning need to be
  1187 covered by the constraints in the initial statement, completed by the
  1188 type instance information of the background theory.  Non-trivial sort
  1189 hypotheses, which rarely occur in practice, may be specified via
  1190 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1191 
  1192   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1193 
  1194 The result contains an implicit sort hypotheses as before --
  1195 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1196 normalization.
  1197 
  1198 * Generalized Isar history, with support for linear undo, direct state
  1199 addressing etc.
  1200 
  1201 * Changed defaults for unify configuration options:
  1202 
  1203   unify_trace_bound = 50 (formerly 25)
  1204   unify_search_bound = 60 (formerly 30)
  1205 
  1206 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1207 
  1208   a) On theory merge, the last set of code equations for a particular
  1209      constant is taken (in accordance with the policy applied by other
  1210      parts of the code generator framework).
  1211 
  1212   b) Code equations stemming from explicit declarations (e.g. code
  1213      attribute) gain priority over default code equations stemming
  1214      from definition, primrec, fun etc.
  1215 
  1216 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1217 
  1218 * Unified theorem tables for both code generators.  Thus [code
  1219 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1220 
  1221 * Command 'find_consts' searches for constants based on type and name
  1222 patterns, e.g.
  1223 
  1224     find_consts "_ => bool"
  1225 
  1226 By default, matching is against subtypes, but it may be restricted to
  1227 the whole type.  Searching by name is possible.  Multiple queries are
  1228 conjunctive and queries may be negated by prefixing them with a
  1229 hyphen:
  1230 
  1231     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1232 
  1233 * New 'find_theorems' criterion "solves" matches theorems that
  1234 directly solve the current goal (modulo higher-order unification).
  1235 
  1236 * Auto solve feature for main theorem statements: whenever a new goal
  1237 is stated, "find_theorems solves" is called; any theorems that could
  1238 solve the lemma directly are listed as part of the goal state.
  1239 Cf. associated options in Proof General Isabelle settings menu,
  1240 enabled by default, with reasonable timeout for pathological cases of
  1241 higher-order unification.
  1242 
  1243 
  1244 *** Document preparation ***
  1245 
  1246 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1247 demanding keyword 'by' and supporting the full method expression
  1248 syntax just like the Isar command 'by'.
  1249 
  1250 
  1251 *** HOL ***
  1252 
  1253 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1254 points Main and Complex_Main remain as before.
  1255 
  1256 * Logic image HOL-Plain provides a minimal HOL with the most important
  1257 tools available (inductive, datatype, primrec, ...).  This facilitates
  1258 experimentation and tool development.  Note that user applications
  1259 (and library theories) should never refer to anything below theory
  1260 Main, as before.
  1261 
  1262 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1263 experimentation due to shorter build times.
  1264 
  1265 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1266 were previously part of former HOL-Complex.  Entry point Hyperreal
  1267 remains valid, but theories formerly using Complex_Main should now use
  1268 new entry point Hypercomplex.
  1269 
  1270 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1271 Posix processes.  Avoids potentially expensive forking of the ML
  1272 process.  New thread-based implementation also works on non-Unix
  1273 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1274 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1275 commands are covered in the isar-ref manual.
  1276 
  1277 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1278 sledgehammer without local ATP installation (Vampire etc.). Other
  1279 provers may be included via suitable ML wrappers, see also
  1280 src/HOL/ATP_Linkup.thy.
  1281 
  1282 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1283 menu.
  1284 
  1285 * The metis method no longer fails because the theorem is too trivial
  1286 (contains the empty clause).
  1287 
  1288 * The metis method now fails in the usual manner, rather than raising
  1289 an exception, if it determines that it cannot prove the theorem.
  1290 
  1291 * Method "coherent" implements a prover for coherent logic (see also
  1292 src/Tools/coherent.ML).
  1293 
  1294 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1295 "undefined" is the right choice to replace "arbitrary", though
  1296 logically there is no difference.  INCOMPATIBILITY.
  1297 
  1298 * Command "value" now integrates different evaluation mechanisms.  The
  1299 result of the first successful evaluation mechanism is printed.  In
  1300 square brackets a particular named evaluation mechanisms may be
  1301 specified (currently, [SML], [code] or [nbe]).  See further
  1302 src/HOL/ex/Eval_Examples.thy.
  1303 
  1304 * Normalization by evaluation now allows non-leftlinear equations.
  1305 Declare with attribute [code nbe].
  1306 
  1307 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1308 as the structured Isar versions "cases" and "induct", cf. the
  1309 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1310 are now presented as a list of individual projections
  1311 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1312 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1313 rare situations a different rule is selected --- notably nested tuple
  1314 elimination instead of former prod.exhaust: use explicit (case_tac t
  1315 rule: prod.exhaust) here.
  1316 
  1317 * Attributes "cases", "induct", "coinduct" support "del" option.
  1318 
  1319 * Removed fact "case_split_thm", which duplicates "case_split".
  1320 
  1321 * The option datatype has been moved to a new theory Option.  Renamed
  1322 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1323 
  1324 * New predicate "strict_mono" classifies strict functions on partial
  1325 orders.  With strict functions on linear orders, reasoning about
  1326 (in)equalities is facilitated by theorems "strict_mono_eq",
  1327 "strict_mono_less_eq" and "strict_mono_less".
  1328 
  1329 * Some set operations are now proper qualified constants with
  1330 authentic syntax.  INCOMPATIBILITY:
  1331 
  1332     op Int ~>   Set.Int
  1333     op Un ~>    Set.Un
  1334     INTER ~>    Set.INTER
  1335     UNION ~>    Set.UNION
  1336     Inter ~>    Set.Inter
  1337     Union ~>    Set.Union
  1338     {} ~>       Set.empty
  1339     UNIV ~>     Set.UNIV
  1340 
  1341 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1342 theory Set.
  1343 
  1344 * Auxiliary class "itself" has disappeared -- classes without any
  1345 parameter are treated as expected by the 'class' command.
  1346 
  1347 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1348 
  1349 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1350 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1351 
  1352 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1353 method "approximation".  It proves formulas on real values by using
  1354 interval arithmetic.  In the formulas are also the transcendental
  1355 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1356 allowed. For examples see
  1357 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1358 
  1359 * Theory "Reflection" now resides in HOL/Library.
  1360 
  1361 * Entry point to Word library now simply named "Word".
  1362 INCOMPATIBILITY.
  1363 
  1364 * Made source layout more coherent with logical distribution
  1365 structure:
  1366 
  1367     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1368     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1369     src/HOL/Library/GCD.thy ~> src/HOL/
  1370     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1371     src/HOL/Library/Parity.thy ~> src/HOL/
  1372     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1373     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1374     src/HOL/Real/Lubs.thy ~> src/HOL/
  1375     src/HOL/Real/PReal.thy ~> src/HOL/
  1376     src/HOL/Real/Rational.thy ~> src/HOL/
  1377     src/HOL/Real/RComplete.thy ~> src/HOL/
  1378     src/HOL/Real/RealDef.thy ~> src/HOL/
  1379     src/HOL/Real/RealPow.thy ~> src/HOL/
  1380     src/HOL/Real/Real.thy ~> src/HOL/
  1381     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1382     src/HOL/Complex/Complex.thy ~> src/HOL/
  1383     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1384     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1385     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1386     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1387     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1388     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1389     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1390     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1391     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1392     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1393     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1394     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1395     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1396     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1397     src/HOL/Real/Float ~> src/HOL/Library/
  1398     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1399     src/HOL/Real/RealVector.thy ~> src/HOL/
  1400 
  1401     src/HOL/arith_data.ML ~> src/HOL/Tools
  1402     src/HOL/hologic.ML ~> src/HOL/Tools
  1403     src/HOL/simpdata.ML ~> src/HOL/Tools
  1404     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1405     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1406     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1407     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1408     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1409     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1410     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1411 
  1412     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1413     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1414     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1415     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1416     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1417     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1418 
  1419 * If methods "eval" and "evaluation" encounter a structured proof
  1420 state with !!/==>, only the conclusion is evaluated to True (if
  1421 possible), avoiding strange error messages.
  1422 
  1423 * Method "sizechange" automates termination proofs using (a
  1424 modification of) the size-change principle.  Requires SAT solver.  See
  1425 src/HOL/ex/Termination.thy for examples.
  1426 
  1427 * Simplifier: simproc for let expressions now unfolds if bound
  1428 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1429 
  1430 * Method "arith": Linear arithmetic now ignores all inequalities when
  1431 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1432 
  1433 * New attribute "arith" for facts that should always be used
  1434 automatically by arithmetic. It is intended to be used locally in
  1435 proofs, e.g.
  1436 
  1437   assumes [arith]: "x > 0"
  1438 
  1439 Global usage is discouraged because of possible performance impact.
  1440 
  1441 * New classes "top" and "bot" with corresponding operations "top" and
  1442 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1443 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1444 
  1445 * Changed definition lemma "less_fun_def" in order to provide an
  1446 instance for preorders on functions; use lemma "less_le" instead.
  1447 INCOMPATIBILITY.
  1448 
  1449 * Theory Orderings: class "wellorder" moved here, with explicit
  1450 induction rule "less_induct" as assumption.  For instantiation of
  1451 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1452 INCOMPATIBILITY.
  1453 
  1454 * Theory Orderings: added class "preorder" as superclass of "order".
  1455 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1456 etc. slightly changed.  Some theorems named order_class.* now named
  1457 preorder_class.*.
  1458 
  1459 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1460 "diag" to "Id_on".
  1461 
  1462 * Theory Finite_Set: added a new fold combinator of type
  1463 
  1464   ('a => 'b => 'b) => 'b => 'a set => 'b
  1465 
  1466 Occasionally this is more convenient than the old fold combinator
  1467 which is now defined in terms of the new one and renamed to
  1468 fold_image.
  1469 
  1470 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1471 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1472 extended with further lemmas!).  At the moment both still exist but
  1473 the former will disappear at some point.
  1474 
  1475 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1476 class recpower.  Type-specific simp rules for various recpower types
  1477 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1478 
  1479 rat_power_0    -> power_0
  1480 rat_power_Suc  -> power_Suc
  1481 realpow_0      -> power_0
  1482 realpow_Suc    -> power_Suc
  1483 complexpow_0   -> power_0
  1484 complexpow_Suc -> power_Suc
  1485 power_poly_0   -> power_0
  1486 power_poly_Suc -> power_Suc
  1487 
  1488 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1489 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1490 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1491 of lemmas from Divides has been generalized from nat to class
  1492 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1493 renames resulting from duplicate elimination:
  1494 
  1495     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1496     zero_dvd_iff ~>         dvd_0_left_iff
  1497     dvd_0 ~>                dvd_0_right
  1498     DIVISION_BY_ZERO_DIV ~> div_by_0
  1499     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1500     mult_div ~>             div_mult_self2_is_id
  1501     mult_mod ~>             mod_mult_self2_is_0
  1502 
  1503 * Theory IntDiv: removed many lemmas that are instances of class-based
  1504 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1505 rename old lemmas as follows:
  1506 
  1507 dvd_diff               -> nat_dvd_diff
  1508 dvd_zminus_iff         -> dvd_minus_iff
  1509 mod_add1_eq            -> mod_add_eq
  1510 mod_mult1_eq           -> mod_mult_right_eq
  1511 mod_mult1_eq'          -> mod_mult_left_eq
  1512 mod_mult_distrib_mod   -> mod_mult_eq
  1513 nat_mod_add_left_eq    -> mod_add_left_eq
  1514 nat_mod_add_right_eq   -> mod_add_right_eq
  1515 nat_mod_div_trivial    -> mod_div_trivial
  1516 nat_mod_mod_trivial    -> mod_mod_trivial
  1517 zdiv_zadd_self1        -> div_add_self1
  1518 zdiv_zadd_self2        -> div_add_self2
  1519 zdiv_zmult_self1       -> div_mult_self2_is_id
  1520 zdiv_zmult_self2       -> div_mult_self1_is_id
  1521 zdvd_triv_left         -> dvd_triv_left
  1522 zdvd_triv_right        -> dvd_triv_right
  1523 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1524 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1525 zmod_zadd_left_eq      -> mod_add_left_eq
  1526 zmod_zadd_right_eq     -> mod_add_right_eq
  1527 zmod_zadd_self1        -> mod_add_self1
  1528 zmod_zadd_self2        -> mod_add_self2
  1529 zmod_zadd1_eq          -> mod_add_eq
  1530 zmod_zdiff1_eq         -> mod_diff_eq
  1531 zmod_zdvd_zmod         -> mod_mod_cancel
  1532 zmod_zmod_cancel       -> mod_mod_cancel
  1533 zmod_zmult_self1       -> mod_mult_self2_is_0
  1534 zmod_zmult_self2       -> mod_mult_self1_is_0
  1535 zmod_1                 -> mod_by_1
  1536 zdiv_1                 -> div_by_1
  1537 zdvd_abs1              -> abs_dvd_iff
  1538 zdvd_abs2              -> dvd_abs_iff
  1539 zdvd_refl              -> dvd_refl
  1540 zdvd_trans             -> dvd_trans
  1541 zdvd_zadd              -> dvd_add
  1542 zdvd_zdiff             -> dvd_diff
  1543 zdvd_zminus_iff        -> dvd_minus_iff
  1544 zdvd_zminus2_iff       -> minus_dvd_iff
  1545 zdvd_zmultD            -> dvd_mult_right
  1546 zdvd_zmultD2           -> dvd_mult_left
  1547 zdvd_zmult_mono        -> mult_dvd_mono
  1548 zdvd_0_right           -> dvd_0_right
  1549 zdvd_0_left            -> dvd_0_left_iff
  1550 zdvd_1_left            -> one_dvd
  1551 zminus_dvd_iff         -> minus_dvd_iff
  1552 
  1553 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1554 
  1555 * The real numbers offer decimal input syntax: 12.34 is translated
  1556 into 1234/10^2. This translation is not reversed upon output.
  1557 
  1558 * Theory Library/Polynomial defines an abstract type 'a poly of
  1559 univariate polynomials with coefficients of type 'a.  In addition to
  1560 the standard ring operations, it also supports div and mod.  Code
  1561 generation is also supported, using list-style constructors.
  1562 
  1563 * Theory Library/Inner_Product defines a class of real_inner for real
  1564 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1565 => real.  Class real_inner is a subclass of real_normed_vector from
  1566 theory RealVector.
  1567 
  1568 * Theory Library/Product_Vector provides instances for the product
  1569 type 'a * 'b of several classes from RealVector and Inner_Product.
  1570 Definitions of addition, subtraction, scalar multiplication, norms,
  1571 and inner products are included.
  1572 
  1573 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1574 addition to the field operations, numerals and case syntax are also
  1575 supported.
  1576 
  1577 * Theory Library/Diagonalize provides constructive version of Cantor's
  1578 first diagonalization argument.
  1579 
  1580 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1581 zlcm (for int); carried together from various gcd/lcm developements in
  1582 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1583 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1584 may recover tupled syntax as follows:
  1585 
  1586     hide (open) const gcd
  1587     abbreviation gcd where
  1588       "gcd == (%(a, b). GCD.gcd a b)"
  1589     notation (output)
  1590       GCD.gcd ("gcd '(_, _')")
  1591 
  1592 The same works for lcm, zgcd, zlcm.
  1593 
  1594 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1595 instantiations for algebraic structures.  Removed some duplicate
  1596 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1597 
  1598 * ML antiquotation @{code} takes a constant as argument and generates
  1599 corresponding code in background and inserts name of the corresponding
  1600 resulting ML value/function/datatype constructor binding in place.
  1601 All occurrences of @{code} with a single ML block are generated
  1602 simultaneously.  Provides a generic and safe interface for
  1603 instrumentalizing code generation.  See
  1604 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1605 In future you ought to refrain from ad-hoc compiling generated SML
  1606 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1607 cannot refer to constants for which user-defined serializations are
  1608 set.  Refer to the corresponding ML counterpart directly in that
  1609 cases.
  1610 
  1611 * Command 'rep_datatype': instead of theorem names the command now
  1612 takes a list of terms denoting the constructors of the type to be
  1613 represented as datatype.  The characteristic theorems have to be
  1614 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1615 have disappeared in favour of existing ones:
  1616 
  1617     unit_induct                 ~> unit.induct
  1618     prod_induct                 ~> prod.induct
  1619     sum_induct                  ~> sum.induct
  1620     Suc_Suc_eq                  ~> nat.inject
  1621     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1622 
  1623 
  1624 *** HOL-Algebra ***
  1625 
  1626 * New locales for orders and lattices where the equivalence relation
  1627 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1628 locales use a record structure with field eq for the equivalence.
  1629 
  1630 * New theory of factorial domains.
  1631 
  1632 * Units_l_inv and Units_r_inv are now simp rules by default.
  1633 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1634 and/or r_inv will now also require deletion of these lemmas.
  1635 
  1636 * Renamed the following theorems, INCOMPATIBILITY:
  1637 
  1638 UpperD ~> Upper_memD
  1639 LowerD ~> Lower_memD
  1640 least_carrier ~> least_closed
  1641 greatest_carrier ~> greatest_closed
  1642 greatest_Lower_above ~> greatest_Lower_below
  1643 one_zero ~> carrier_one_zero
  1644 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1645 
  1646 
  1647 *** HOL-Nominal ***
  1648 
  1649 * Nominal datatypes can now contain type-variables.
  1650 
  1651 * Commands 'nominal_inductive' and 'equivariance' work with local
  1652 theory targets.
  1653 
  1654 * Nominal primrec can now works with local theory targets and its
  1655 specification syntax now conforms to the general format as seen in
  1656 'inductive' etc.
  1657 
  1658 * Method "perm_simp" honours the standard simplifier attributes
  1659 (no_asm), (no_asm_use) etc.
  1660 
  1661 * The new predicate #* is defined like freshness, except that on the
  1662 left hand side can be a set or list of atoms.
  1663 
  1664 * Experimental command 'nominal_inductive2' derives strong induction
  1665 principles for inductive definitions.  In contrast to
  1666 'nominal_inductive', which can only deal with a fixed number of
  1667 binders, it can deal with arbitrary expressions standing for sets of
  1668 atoms to be avoided.  The only inductive definition we have at the
  1669 moment that needs this generalisation is the typing rule for Lets in
  1670 the algorithm W:
  1671 
  1672  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1673  -----------------------------------------------------------------
  1674          Gamma |- Let x be t1 in t2 : T2
  1675 
  1676 In this rule one wants to avoid all the binders that are introduced by
  1677 "close Gamma T1".  We are looking for other examples where this
  1678 feature might be useful.  Please let us know.
  1679 
  1680 
  1681 *** HOLCF ***
  1682 
  1683 * Reimplemented the simplification procedure for proving continuity
  1684 subgoals.  The new simproc is extensible; users can declare additional
  1685 continuity introduction rules with the attribute [cont2cont].
  1686 
  1687 * The continuity simproc now uses a different introduction rule for
  1688 solving continuity subgoals on terms with lambda abstractions.  In
  1689 some rare cases the new simproc may fail to solve subgoals that the
  1690 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1691 Potential INCOMPATIBILITY.
  1692 
  1693 * Command 'fixrec': specification syntax now conforms to the general
  1694 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1695 examples.  INCOMPATIBILITY.
  1696 
  1697 
  1698 *** ZF ***
  1699 
  1700 * Proof of Zorn's Lemma for partial orders.
  1701 
  1702 
  1703 *** ML ***
  1704 
  1705 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1706 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1707 depends on multithreading, so timouts will not work before Poly/ML
  1708 5.2.1!
  1709 
  1710 * High-level support for concurrent ML programming, see
  1711 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1712 particularly convenient to organize independent functional
  1713 computations.  The concept of "synchronized variables" provides a
  1714 higher-order interface for components with shared state, avoiding the
  1715 delicate details of mutexes and condition variables.  (Requires
  1716 Poly/ML 5.2.1 or later.)
  1717 
  1718 * ML bindings produced via Isar commands are stored within the Isar
  1719 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1720 become thread-safe and work with undo as expected (concerning
  1721 top-level bindings, not side-effects on global references).
  1722 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1723 compiler at runtime; really global bindings need to be given outside a
  1724 theory.  (Requires Poly/ML 5.2 or later.)
  1725 
  1726 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1727 context.  Top-level ML bindings are stored within the proof context in
  1728 a purely sequential fashion, disregarding the nested proof structure.
  1729 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1730 proof.  (Requires Poly/ML 5.2 or later.)
  1731 
  1732 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1733 and Method.setup, as well as Isar commands 'attribute_setup' and
  1734 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1735 existing code accordingly, or use plain 'setup' together with old
  1736 Method.add_method.
  1737 
  1738 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1739 to 'a -> thm, while results are always tagged with an authentic oracle
  1740 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1741 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1742 accordingly.  Note that extra performance may be gained by producing
  1743 the cterm carefully, avoiding slow Thm.cterm_of.
  1744 
  1745 * Simplified interface for defining document antiquotations via
  1746 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1747 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1748 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1749 examples.
  1750 
  1751 * More systematic treatment of long names, abstract name bindings, and
  1752 name space operations.  Basic operations on qualified names have been
  1753 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1754 Long_Name.append.  Old type bstring has been mostly replaced by
  1755 abstract type binding (see structure Binding), which supports precise
  1756 qualification by packages and local theory targets, as well as proper
  1757 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1758 bstring values into Binding.name, or better pass through abstract
  1759 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1760 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1761 
  1762 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1763 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1764 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1765 
  1766 * Disposed old type and term read functions (Sign.read_def_typ,
  1767 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1768 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1769 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1770 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1771 resort for legacy applications.
  1772 
  1773 * Disposed old declarations, tactics, tactic combinators that refer to
  1774 the simpset or claset of an implicit theory (such as Addsimps,
  1775 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1776 embedded ML text, or local_simpset_of with a proper context passed as
  1777 explicit runtime argument.
  1778 
  1779 * Rules and tactics that read instantiations (read_instantiate,
  1780 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1781 context, which is required for parsing and type-checking.  Moreover,
  1782 the variables are specified as plain indexnames, not string encodings
  1783 thereof.  INCOMPATIBILITY.
  1784 
  1785 * Generic Toplevel.add_hook interface allows to analyze the result of
  1786 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1787 for theorem dependency output of transactions resulting in a new
  1788 theory state.
  1789 
  1790 * ML antiquotations: block-structured compilation context indicated by
  1791 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1792 
  1793   @{binding name}                         - basic name binding
  1794   @{let ?pat = term}                      - term abbreviation (HO matching)
  1795   @{note name = fact}                     - fact abbreviation
  1796   @{thm fact}                             - singleton fact (with attributes)
  1797   @{thms fact}                            - general fact (with attributes)
  1798   @{lemma prop by method}                 - singleton goal
  1799   @{lemma prop by meth1 meth2}            - singleton goal
  1800   @{lemma prop1 ... propN by method}      - general goal
  1801   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1802   @{lemma (open) ...}                     - open derivation
  1803 
  1804 
  1805 *** System ***
  1806 
  1807 * The Isabelle "emacs" tool provides a specific interface to invoke
  1808 Proof General / Emacs, with more explicit failure if that is not
  1809 installed (the old isabelle-interface script silently falls back on
  1810 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1811 installation location of the Proof General distribution.
  1812 
  1813 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1814 the Isabelle process into a JVM/Scala application.  See
  1815 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1816 process wrapper has been discontinued.)
  1817 
  1818 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1819 
  1820 * Various status messages (with exact source position information) are
  1821 emitted, if proper markup print mode is enabled.  This allows
  1822 user-interface components to provide detailed feedback on internal
  1823 prover operations.
  1824 
  1825 
  1826 
  1827 New in Isabelle2008 (June 2008)
  1828 -------------------------------
  1829 
  1830 *** General ***
  1831 
  1832 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1833 and updated, with formally checked references as hyperlinks.
  1834 
  1835 * Theory loader: use_thy (and similar operations) no longer set the
  1836 implicit ML context, which was occasionally hard to predict and in
  1837 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1838 provides a proper context already.
  1839 
  1840 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1841 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1842 'use' within a theory file will do the job.
  1843 
  1844 * Name space merge now observes canonical order, i.e. the second space
  1845 is inserted into the first one, while existing entries in the first
  1846 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1847 swap theory imports.
  1848 
  1849 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1850 INCOMPATIBILITY in identifier syntax etc.
  1851 
  1852 * Outer syntax: string tokens no longer admit escaped white space,
  1853 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1854 white space without escapes.
  1855 
  1856 * Outer syntax: string tokens may contain arbitrary character codes
  1857 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1858 "foo_bar".
  1859 
  1860 
  1861 *** Pure ***
  1862 
  1863 * Context-dependent token translations.  Default setup reverts locally
  1864 fixed variables, and adds hilite markup for undeclared frees.
  1865 
  1866 * Unused theorems can be found using the new command 'unused_thms'.
  1867 There are three ways of invoking it:
  1868 
  1869 (1) unused_thms
  1870      Only finds unused theorems in the current theory.
  1871 
  1872 (2) unused_thms thy_1 ... thy_n -
  1873      Finds unused theorems in the current theory and all of its ancestors,
  1874      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1875 
  1876 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1877      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1878      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1879      their ancestors.
  1880 
  1881 In order to increase the readability of the list produced by
  1882 unused_thms, theorems that have been created by a particular instance
  1883 of a theory command such as 'inductive' or 'function' are considered
  1884 to belong to the same "group", meaning that if at least one theorem in
  1885 this group is used, the other theorems in the same group are no longer
  1886 reported as unused.  Moreover, if all theorems in the group are
  1887 unused, only one theorem in the group is displayed.
  1888 
  1889 Note that proof objects have to be switched on in order for
  1890 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1891 usually the case when using Proof General with the default settings).
  1892 
  1893 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1894 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1895 duplicate fact bindings, or even accidental fact duplications.  Note
  1896 that tools may maintain dynamically scoped facts systematically, using
  1897 PureThy.add_thms_dynamic.
  1898 
  1899 * Command 'hide' now allows to hide from "fact" name space as well.
  1900 
  1901 * Eliminated destructive theorem database, simpset, claset, and
  1902 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1903 update of theories within ML code.
  1904 
  1905 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1906 INCOMPATIBILITY, object-logics depending on former Pure require
  1907 additional setup PureThy.old_appl_syntax_setup; object-logics
  1908 depending on former CPure need to refer to Pure.
  1909 
  1910 * Commands 'use' and 'ML' are now purely functional, operating on
  1911 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1912 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1913 INCOMPATIBILITY.
  1914 
  1915 * Command 'setup': discontinued implicit version with ML reference.
  1916 
  1917 * Instantiation target allows for simultaneous specification of class
  1918 instance operations together with an instantiation proof.
  1919 Type-checking phase allows to refer to class operations uniformly.
  1920 See src/HOL/Complex/Complex.thy for an Isar example and
  1921 src/HOL/Library/Eval.thy for an ML example.
  1922 
  1923 * Indexing of literal facts: be more serious about including only
  1924 facts from the visible specification/proof context, but not the
  1925 background context (locale etc.).  Affects `prop` notation and method
  1926 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1927 situations.
  1928 
  1929 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1930 "(open)" option, which used to expose internal bound variables to the
  1931 proof text.
  1932 
  1933 * Isar statements: removed obsolete case "rule_context".
  1934 INCOMPATIBILITY, better use explicit fixes/assumes.
  1935 
  1936 * Locale proofs: default proof step now includes 'unfold_locales';
  1937 hence 'proof' without argument may be used to unfold locale
  1938 predicates.
  1939 
  1940 
  1941 *** Document preparation ***
  1942 
  1943 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1944 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1945 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1946 spot); renamed link color from "darkblue" to "linkcolor" (default
  1947 value unchanged, can be redefined via \definecolor); no longer sets
  1948 "a4paper" option (unnecessary or even intrusive).
  1949 
  1950 * Antiquotation @{lemma A method} proves proposition A by the given
  1951 method (either a method name or a method name plus (optional) method
  1952 arguments in parentheses) and prints A just like @{prop A}.
  1953 
  1954 
  1955 *** HOL ***
  1956 
  1957 * New primrec package.  Specification syntax conforms in style to
  1958 definition/function/....  No separate induction rule is provided.  The
  1959 "primrec" command distinguishes old-style and new-style specifications
  1960 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1961 When adjusting theories, beware: constants stemming from new-style
  1962 primrec specifications have authentic syntax.
  1963 
  1964 * Metis prover is now an order of magnitude faster, and also works
  1965 with multithreading.
  1966 
  1967 * Metis: the maximum number of clauses that can be produced from a
  1968 theorem is now given by the attribute max_clauses.  Theorems that
  1969 exceed this number are ignored, with a warning printed.
  1970 
  1971 * Sledgehammer no longer produces structured proofs by default. To
  1972 enable, declare [[sledgehammer_full = true]].  Attributes
  1973 reconstruction_modulus, reconstruction_sorts renamed
  1974 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1975 
  1976 * Method "induct_scheme" derives user-specified induction rules
  1977 from well-founded induction and completeness of patterns. This factors
  1978 out some operations that are done internally by the function package
  1979 and makes them available separately.  See
  1980 src/HOL/ex/Induction_Scheme.thy for examples.
  1981 
  1982 * More flexible generation of measure functions for termination
  1983 proofs: Measure functions can be declared by proving a rule of the
  1984 form "is_measure f" and giving it the [measure_function] attribute.
  1985 The "is_measure" predicate is logically meaningless (always true), and
  1986 just guides the heuristic.  To find suitable measure functions, the
  1987 termination prover sets up the goal "is_measure ?f" of the appropriate
  1988 type and generates all solutions by prolog-style backwards proof using
  1989 the declared rules.
  1990 
  1991 This setup also deals with rules like 
  1992 
  1993   "is_measure f ==> is_measure (list_size f)"
  1994 
  1995 which accommodates nested datatypes that recurse through lists.
  1996 Similar rules are predeclared for products and option types.
  1997 
  1998 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1999 
  2000   INCOMPATIBILITIES:
  2001 
  2002   - Definitions of overloaded constants on sets have to be replaced by
  2003     definitions on => and bool.
  2004 
  2005   - Some definitions of overloaded operators on sets can now be proved
  2006     using the definitions of the operators on => and bool.  Therefore,
  2007     the following theorems have been renamed:
  2008 
  2009       subset_def   -> subset_eq
  2010       psubset_def  -> psubset_eq
  2011       set_diff_def -> set_diff_eq
  2012       Compl_def    -> Compl_eq
  2013       Sup_set_def  -> Sup_set_eq
  2014       Inf_set_def  -> Inf_set_eq
  2015       sup_set_def  -> sup_set_eq
  2016       inf_set_def  -> inf_set_eq
  2017 
  2018   - Due to the incompleteness of the HO unification algorithm, some
  2019     rules such as subst may require manual instantiation, if some of
  2020     the unknowns in the rule is a set.
  2021 
  2022   - Higher order unification and forward proofs:
  2023     The proof pattern
  2024 
  2025       have "P (S::'a set)" <...>
  2026       then have "EX S. P S" ..
  2027 
  2028     no longer works (due to the incompleteness of the HO unification
  2029     algorithm) and must be replaced by the pattern
  2030 
  2031       have "EX S. P S"
  2032       proof
  2033         show "P S" <...>
  2034       qed
  2035 
  2036   - Calculational reasoning with subst (or similar rules):
  2037     The proof pattern
  2038 
  2039       have "P (S::'a set)" <...>
  2040       also have "S = T" <...>
  2041       finally have "P T" .
  2042 
  2043     no longer works (for similar reasons as the previous example) and
  2044     must be replaced by something like
  2045 
  2046       have "P (S::'a set)" <...>
  2047       moreover have "S = T" <...>
  2048       ultimately have "P T" by simp
  2049 
  2050   - Tactics or packages written in ML code:
  2051     Code performing pattern matching on types via
  2052 
  2053       Type ("set", [T]) => ...
  2054 
  2055     must be rewritten. Moreover, functions like strip_type or
  2056     binder_types no longer return the right value when applied to a
  2057     type of the form
  2058 
  2059       T1 => ... => Tn => U => bool
  2060 
  2061     rather than
  2062 
  2063       T1 => ... => Tn => U set
  2064 
  2065 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2066 Wellfounded_Relations to theory Wellfounded.
  2067 
  2068 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2069 
  2070 * Class finite no longer treats UNIV as class parameter.  Use class
  2071 enum from theory Library/Enum instead to achieve a similar effect.
  2072 INCOMPATIBILITY.
  2073 
  2074 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2075 and "Cons".  INCOMPATIBILITY.
  2076 
  2077 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2078 Potential INCOMPATIBILITY.
  2079 
  2080 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2081 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2082 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2083 
  2084 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2085 the same name in theory Orderings:
  2086 
  2087   less_trans
  2088   less_linear
  2089   le_imp_less_or_eq
  2090   le_less_trans
  2091   less_le_trans
  2092   less_not_sym
  2093   less_asym
  2094 
  2095 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2096 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2097 and different variable names.
  2098 
  2099 * Library/Option_ord.thy: Canonical order on option type.
  2100 
  2101 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2102 finite maps.
  2103 
  2104 * Library/Countable.thy: Type class for countable types.
  2105 
  2106 * Theory Int: The representation of numerals has changed.  The infix
  2107 operator BIT and the bit datatype with constructors B0 and B1 have
  2108 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2109 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2110 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2111 accordingly.
  2112 
  2113 * Theory Nat: definition of <= and < on natural numbers no longer
  2114 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2115 le_def and less_def have disappeared.  Consider lemmas not_less
  2116 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2117 
  2118 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2119 (whose purpose mainly is for various fold_set functionals) have been
  2120 abandoned in favor of the existing algebraic classes
  2121 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2122 lower_semilattice (resp. upper_semilattice) and linorder.
  2123 INCOMPATIBILITY.
  2124 
  2125 * Theory Transitive_Closure: induct and cases rules now declare proper
  2126 case_names ("base" and "step").  INCOMPATIBILITY.
  2127 
  2128 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2129 lattices.  The form set-specific version is available as
  2130 Inductive.lfp_ordinal_induct_set.
  2131 
  2132 * Renamed theorems "power.simps" to "power_int.simps".
  2133 INCOMPATIBILITY.
  2134 
  2135 * Class semiring_div provides basic abstract properties of semirings
  2136 with division and modulo operations.  Subsumes former class dvd_mod.
  2137 
  2138 * Merged theories IntDef, Numeral and IntArith into unified theory
  2139 Int.  INCOMPATIBILITY.
  2140 
  2141 * Theory Library/Code_Index: type "index" now represents natural
  2142 numbers rather than integers.  INCOMPATIBILITY.
  2143 
  2144 * New class "uminus" with operation "uminus" (split of from class
  2145 "minus" which now only has operation "minus", binary).
  2146 INCOMPATIBILITY.
  2147 
  2148 * Constants "card", "internal_split", "option_map" now with authentic
  2149 syntax.  INCOMPATIBILITY.
  2150 
  2151 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2152 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2153 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2154 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2155 Sup_set_def, le_def, less_def, option_map_def now with object
  2156 equality.  INCOMPATIBILITY.
  2157 
  2158 * Records. Removed K_record, and replaced it by pure lambda term
  2159 %x. c. The simplifier setup is now more robust against eta expansion.
  2160 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2161 
  2162 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2163 
  2164 * Library/ListVector: new theory of arithmetic vector operations.
  2165 
  2166 * Library/Order_Relation: new theory of various orderings as sets of
  2167 pairs.  Defines preorders, partial orders, linear orders and
  2168 well-orders on sets and on types.
  2169 
  2170 
  2171 *** ZF ***
  2172 
  2173 * Renamed some theories to allow to loading both ZF and HOL in the
  2174 same session:
  2175 
  2176   Datatype  -> Datatype_ZF
  2177   Inductive -> Inductive_ZF
  2178   Int       -> Int_ZF
  2179   IntDiv    -> IntDiv_ZF
  2180   Nat       -> Nat_ZF
  2181   List      -> List_ZF
  2182   Main      -> Main_ZF
  2183 
  2184 INCOMPATIBILITY: ZF theories that import individual theories below
  2185 Main might need to be adapted.  Regular theory Main is still
  2186 available, as trivial extension of Main_ZF.
  2187 
  2188 
  2189 *** ML ***
  2190 
  2191 * ML within Isar: antiquotation @{const name} or @{const
  2192 name(typargs)} produces statically-checked Const term.
  2193 
  2194 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2195 (of the same name).  Removed obsolete print command.
  2196 
  2197 * Removed obsolete "use_legacy_bindings" function.
  2198 
  2199 * The ``print mode'' is now a thread-local value derived from a global
  2200 template (the former print_mode reference), thus access becomes
  2201 non-critical.  The global print_mode reference is for session
  2202 management only; user-code should use print_mode_value,
  2203 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2204 
  2205 * Functions system/system_out provide a robust way to invoke external
  2206 shell commands, with propagation of interrupts (requires Poly/ML
  2207 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2208 
  2209 
  2210 *** System ***
  2211 
  2212 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2213 in accordance with Proof General 3.7, which prefers GNU emacs.
  2214 
  2215 * isatool tty runs Isabelle process with plain tty interaction;
  2216 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2217 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2218 
  2219 * isatool browser now works with Cygwin as well, using general
  2220 "javapath" function defined in Isabelle process environment.
  2221 
  2222 * YXML notation provides a simple and efficient alternative to
  2223 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2224 isatool yxml as described in the Isabelle system manual.
  2225 
  2226 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2227 provides general wrapper for managing an Isabelle process in a robust
  2228 fashion, with ``cooked'' output from stdin/stderr.
  2229 
  2230 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2231 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2232 
  2233 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2234 way of changing the user's settings is via
  2235 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2236 script.
  2237 
  2238 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2239 cores of the underlying machine, which is a good starting point for
  2240 optimal performance tuning.  The corresponding usedir option -M allows
  2241 "max" as an alias for "0".  WARNING: does not work on certain versions
  2242 of Mac OS (with Poly/ML 5.1).
  2243 
  2244 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2245 adverse effect of Isabelle flooding interactive front-ends (notably
  2246 ProofGeneral / XEmacs).
  2247 
  2248 
  2249 
  2250 New in Isabelle2007 (November 2007)
  2251 -----------------------------------
  2252 
  2253 *** General ***
  2254 
  2255 * More uniform information about legacy features, notably a
  2256 warning/error of "Legacy feature: ...", depending on the state of the
  2257 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2258 legacy features will disappear eventually.
  2259 
  2260 * Theory syntax: the header format ``theory A = B + C:'' has been
  2261 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2262 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2263 
  2264 * Theory syntax: the old non-Isar theory file format has been
  2265 discontinued altogether.  Note that ML proof scripts may still be used
  2266 with Isar theories; migration is usually quite simple with the ML
  2267 function use_legacy_bindings.  INCOMPATIBILITY.
  2268 
  2269 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2270 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2271 quotes.
  2272 
  2273 * Theory loader: be more serious about observing the static theory
  2274 header specifications (including optional directories), but not the
  2275 accidental file locations of previously successful loads.  The strict
  2276 update policy of former update_thy is now already performed by
  2277 use_thy, so the former has been removed; use_thys updates several
  2278 theories simultaneously, just as 'imports' within a theory header
  2279 specification, but without merging the results.  Potential
  2280 INCOMPATIBILITY: may need to refine theory headers and commands
  2281 ROOT.ML which depend on load order.
  2282 
  2283 * Theory loader: optional support for content-based file
  2284 identification, instead of the traditional scheme of full physical
  2285 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2286 (cf. the system manual).  The new scheme allows to work with
  2287 non-finished theories in persistent session images, such that source
  2288 files may be moved later on without requiring reloads.
  2289 
  2290 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2291 file (with the same base name as the theory) are considered a legacy
  2292 feature, which will disappear eventually. Even now, the theory loader
  2293 no longer maintains dependencies on such files.
  2294 
  2295 * Syntax: the scope for resolving ambiguities via type-inference is
  2296 now limited to individual terms, instead of whole simultaneous
  2297 specifications as before. This greatly reduces the complexity of the
  2298 syntax module and improves flexibility by separating parsing and
  2299 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2300 'fixes' etc.) are required in rare situations.
  2301 
  2302 * Syntax: constants introduced by new-style packages ('definition',
  2303 'abbreviation' etc.) are passed through the syntax module in
  2304 ``authentic mode''. This means that associated mixfix annotations
  2305 really stick to such constants, independently of potential name space
  2306 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2307 trees are represented slightly differently, may need to adapt syntax
  2308 translations accordingly. Use CONST marker in 'translations' and
  2309 @{const_syntax} antiquotation in 'parse_translation' etc.
  2310 
  2311 * Legacy goal package: reduced interface to the bare minimum required
  2312 to keep existing proof scripts running.  Most other user-level
  2313 functions are now part of the OldGoals structure, which is *not* open
  2314 by default (consider isatool expandshort before open OldGoals).
  2315 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2316 these tend to cause confusion about the actual goal (!) context being
  2317 used here, which is not necessarily the same as the_context().
  2318 
  2319 * Command 'find_theorems': supports "*" wild-card in "name:"
  2320 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2321 support a specific search form (see ProofGeneral/CHANGES).
  2322 
  2323 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2324 by default, which means that "prems" (and also "fixed variables") are
  2325 suppressed from proof state output.  Note that the ProofGeneral
  2326 settings mechanism allows to change and save options persistently, but
  2327 older versions of Isabelle will fail to start up if a negative prems
  2328 limit is imposed.
  2329 
  2330 * Local theory targets may be specified by non-nested blocks of
  2331 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2332 contain definitions, theorems etc., including any derived mechanism
  2333 that has been implemented on top of these primitives.  This concept
  2334 generalizes the existing ``theorem (in ...)'' towards more versatility
  2335 and scalability.
  2336 
  2337 * Proof General interface: proper undo of final 'end' command;
  2338 discontinued Isabelle/classic mode (ML proof scripts).
  2339 
  2340 
  2341 *** Document preparation ***
  2342 
  2343 * Added antiquotation @{theory name} which prints the given name,
  2344 after checking that it refers to a valid ancestor theory in the
  2345 current context.
  2346 
  2347 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2348 check the given source text as ML type/structure, printing verbatim.
  2349 
  2350 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2351 "c args == rhs" given in the current context.  (Any number of
  2352 arguments may be given on the LHS.)
  2353 
  2354 
  2355 *** Pure ***
  2356 
  2357 * The 'class' package offers a combination of axclass and locale to
  2358 achieve Haskell-like type classes in Isabelle.  Definitions and
  2359 theorems within a class context produce both relative results (with
  2360 implicit parameters according to the locale context), and polymorphic
  2361 constants with qualified polymorphism (according to the class
  2362 context).  Within the body context of a 'class' target, a separate
  2363 syntax layer ("user space type system") takes care of converting
  2364 between global polymorphic consts and internal locale representation.
  2365 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2366 "isatool doc classes" provides a tutorial.
  2367 
  2368 * Generic code generator framework allows to generate executable
  2369 code for ML and Haskell (including Isabelle classes).  A short usage
  2370 sketch:
  2371 
  2372     internal compilation:
  2373         export_code <list of constants (term syntax)> in SML
  2374     writing SML code to a file:
  2375         export_code <list of constants (term syntax)> in SML <filename>
  2376     writing OCaml code to a file:
  2377         export_code <list of constants (term syntax)> in OCaml <filename>
  2378     writing Haskell code to a bunch of files:
  2379         export_code <list of constants (term syntax)> in Haskell <filename>
  2380 
  2381     evaluating closed propositions to True/False using code generation:
  2382         method ``eval''
  2383 
  2384 Reasonable default setup of framework in HOL.
  2385 
  2386 Theorem attributs for selecting and transforming function equations theorems:
  2387 
  2388     [code fun]:        select a theorem as function equation for a specific constant
  2389     [code fun del]:    deselect a theorem as function equation for a specific constant
  2390     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2391     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2392 
  2393 User-defined serializations (target in {SML, OCaml, Haskell}):
  2394 
  2395     code_const <and-list of constants (term syntax)>
  2396       {(target) <and-list of const target syntax>}+
  2397 
  2398     code_type <and-list of type constructors>
  2399       {(target) <and-list of type target syntax>}+
  2400 
  2401     code_instance <and-list of instances>
  2402       {(target)}+
  2403         where instance ::= <type constructor> :: <class>
  2404 
  2405     code_class <and_list of classes>
  2406       {(target) <and-list of class target syntax>}+
  2407         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2408 
  2409 code_instance and code_class only are effective to target Haskell.
  2410 
  2411 For example usage see src/HOL/ex/Codegenerator.thy and
  2412 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2413 generation from Isabelle/HOL theories is available via "isatool doc
  2414 codegen".
  2415 
  2416 * Code generator: consts in 'consts_code' Isar commands are now
  2417 referred to by usual term syntax (including optional type
  2418 annotations).
  2419 
  2420 * Command 'no_translations' removes translation rules from theory
  2421 syntax.
  2422 
  2423 * Overloaded definitions are now actually checked for acyclic
  2424 dependencies.  The overloading scheme is slightly more general than
  2425 that of Haskell98, although Isabelle does not demand an exact
  2426 correspondence to type class and instance declarations.
  2427 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2428 exotic versions of overloading -- at the discretion of the user!
  2429 
  2430 Polymorphic constants are represented via type arguments, i.e. the
  2431 instantiation that matches an instance against the most general
  2432 declaration given in the signature.  For example, with the declaration
  2433 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2434 as c(nat).  Overloading is essentially simultaneous structural
  2435 recursion over such type arguments.  Incomplete specification patterns
  2436 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2437 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2438 Command 'print_theory' outputs the normalized system of recursive
  2439 equations, see section "definitions".
  2440 
  2441 * Configuration options are maintained within the theory or proof
  2442 context (with name and type bool/int/string), providing a very simple
  2443 interface to a poor-man's version of general context data.  Tools may
  2444 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2445 these values using Config.get etc.  Users may change options via an
  2446 associated attribute of the same name.  This form of context
  2447 declaration works particularly well with commands 'declare' or
  2448 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2449 very easy to avoid global references, which would not observe Isar
  2450 toplevel undo/redo and fail to work with multithreading.
  2451 
  2452 Various global ML references of Pure and HOL have been turned into
  2453 configuration options:
  2454 
  2455   Unify.search_bound		unify_search_bound
  2456   Unify.trace_bound		unify_trace_bound
  2457   Unify.trace_simp		unify_trace_simp
  2458   Unify.trace_types		unify_trace_types
  2459   Simplifier.simp_depth_limit	simp_depth_limit
  2460   Blast.depth_limit		blast_depth_limit
  2461   DatatypeProp.dtK		datatype_distinctness_limit
  2462   fast_arith_neq_limit  	fast_arith_neq_limit
  2463   fast_arith_split_limit	fast_arith_split_limit
  2464 
  2465 * Named collections of theorems may be easily installed as context
  2466 data using the functor NamedThmsFun (see also
  2467 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2468 attributes; there is also a toplevel print command.  This facility is
  2469 just a common case of general context data, which is the preferred way
  2470 for anything more complex than just a list of facts in canonical
  2471 order.
  2472 
  2473 * Isar: command 'declaration' augments a local theory by generic
  2474 declaration functions written in ML.  This enables arbitrary content
  2475 being added to the context, depending on a morphism that tells the
  2476 difference of the original declaration context wrt. the application
  2477 context encountered later on.
  2478 
  2479 * Isar: proper interfaces for simplification procedures.  Command
  2480 'simproc_setup' declares named simprocs (with match patterns, and body
  2481 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2482 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2483 
  2484 * Isar: an extra pair of brackets around attribute declarations
  2485 abbreviates a theorem reference involving an internal dummy fact,
  2486 which will be ignored later --- only the effect of the attribute on
  2487 the background context will persist.  This form of in-place
  2488 declarations is particularly useful with commands like 'declare' and
  2489 'using', for example ``have A using [[simproc a]] by simp''.
  2490 
  2491 * Isar: method "assumption" (and implicit closing of subproofs) now
  2492 takes simple non-atomic goal assumptions into account: after applying
  2493 an assumption as a rule the resulting subgoals are solved by atomic
  2494 assumption steps.  This is particularly useful to finish 'obtain'
  2495 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2496 without referring to the original premise "!!x. P x ==> thesis" in the
  2497 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2498 more permissive.
  2499 
  2500 * Isar: implicit use of prems from the Isar proof context is
  2501 considered a legacy feature.  Common applications like ``have A .''
  2502 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2503 referencing facts explicitly here improves readability and
  2504 maintainability of proof texts.
  2505 
  2506 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2507 the obtained context from the course of reasoning!  For example:
  2508 
  2509   assume "EX x y. A x & B y"   -- "any previous fact"
  2510   then guess x and y by clarify
  2511 
  2512 This technique is potentially adventurous, depending on the facts and
  2513 proof tools being involved here.
  2514 
  2515 * Isar: known facts from the proof context may be specified as literal
  2516 propositions, using ASCII back-quote syntax.  This works wherever
  2517 named facts used to be allowed so far, in proof commands, proof
  2518 methods, attributes etc.  Literal facts are retrieved from the context
  2519 according to unification of type and term parameters.  For example,
  2520 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2521 theorems in the current context, then these are valid literal facts:
  2522 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2523 
  2524 There is also a proof method "fact" which does the same composition
  2525 for explicit goal states, e.g. the following proof texts coincide with
  2526 certain special cases of literal facts:
  2527 
  2528   have "A" by fact                 ==  note `A`
  2529   have "A ==> B" by fact           ==  note `A ==> B`
  2530   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2531   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2532 
  2533 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2534 outer syntax.  Thus symbolic identifiers may be used without
  2535 additional white space in declarations like this: ``assume *: A''.
  2536 
  2537 * Isar: 'print_facts' prints all local facts of the current context,
  2538 both named and unnamed ones.
  2539 
  2540 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2541 
  2542   def x == "t" and y == "u"
  2543 
  2544 * Isar: added command 'unfolding', which is structurally similar to
  2545 'using', but affects both the goal state and facts by unfolding given
  2546 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2547 'unfolded' attribute may be replaced by first-class proof text.
  2548 
  2549 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2550 and command 'unfolding' now all support object-level equalities
  2551 (potentially conditional).  The underlying notion of rewrite rule is
  2552 analogous to the 'rule_format' attribute, but *not* that of the
  2553 Simplifier (which is usually more generous).
  2554 
  2555 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2556 premises of a theorem by n. Useful in conjunction with drule.
  2557 
  2558 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2559 method expression within a sandbox consisting of the first N
  2560 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2561 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2562 simplifies all new goals that emerge from applying rule foo to the
  2563 originally first one.
  2564 
  2565 * Isar: schematic goals are no longer restricted to higher-order
  2566 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2567 expected.
  2568 
  2569 * Isar: the conclusion of a long theorem statement is now either
  2570 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2571 (essentially a disjunction of cases with local parameters and
  2572 assumptions).  The latter allows to express general elimination rules
  2573 adequately; in this notation common elimination rules look like this:
  2574 
  2575   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2576     assumes "EX x. P x"
  2577     obtains x where "P x"
  2578 
  2579   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2580     assumes "A & B"
  2581     obtains A and B
  2582 
  2583   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2584     assumes "A | B"
  2585     obtains
  2586       A
  2587     | B
  2588 
  2589 The subsequent classical rules even refer to the formal "thesis"
  2590 explicitly:
  2591 
  2592   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2593     obtains "~ thesis"
  2594 
  2595   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2596     obtains "thesis ==> something"
  2597 
  2598 The actual proof of an 'obtains' statement is analogous to that of the
  2599 Isar proof element 'obtain', only that there may be several cases.
  2600 Optional case names may be specified in parentheses; these will be
  2601 available both in the present proof and as annotations in the
  2602 resulting rule, for later use with the 'cases' method (cf. attribute
  2603 case_names).
  2604 
  2605 * Isar: the assumptions of a long theorem statement are available as
  2606 "assms" fact in the proof context.  This is more appropriate than the
  2607 (historical) "prems", which refers to all assumptions of the current
  2608 context, including those from the target locale, proof body etc.
  2609 
  2610 * Isar: 'print_statement' prints theorems from the current theory or
  2611 proof context in long statement form, according to the syntax of a
  2612 top-level lemma.
  2613 
  2614 * Isar: 'obtain' takes an optional case name for the local context
  2615 introduction rule (default "that").
  2616 
  2617 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2618 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2619 to occur.
  2620 
  2621 * Pure: syntax "CONST name" produces a fully internalized constant
  2622 according to the current context.  This is particularly useful for
  2623 syntax translations that should refer to internal constant
  2624 representations independently of name spaces.
  2625 
  2626 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2627 instead of "FOO ". This allows multiple binder declarations to coexist
  2628 in the same context.  INCOMPATIBILITY.
  2629 
  2630 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2631 primitive that also works in a locale context (both for constants and
  2632 fixed variables). Type declaration and internal syntactic representation
  2633 of given constants retrieved from the context. Likewise, the
  2634 'no_notation' command allows to remove given syntax annotations from the
  2635 current context.
  2636 
  2637 * Isar/locales: new derived specification elements 'axiomatization',
  2638 'definition', 'abbreviation', which support type-inference, admit
  2639 object-level specifications (equality, equivalence).  See also the
  2640 isar-ref manual.  Examples:
  2641 
  2642   axiomatization
  2643     eq  (infix "===" 50) where
  2644     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2645 
  2646   definition "f x y = x + y + 1"
  2647   definition g where "g x = f x x"
  2648 
  2649   abbreviation
  2650     neq  (infix "=!=" 50) where
  2651     "x =!= y == ~ (x === y)"
  2652 
  2653 These specifications may be also used in a locale context.  Then the
  2654 constants being introduced depend on certain fixed parameters, and the
  2655 constant name is qualified by the locale base name.  An internal
  2656 abbreviation takes care for convenient input and output, making the
  2657 parameters implicit and using the original short name.  See also
  2658 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2659 entities from a monomorphic theory.
  2660 
  2661 Presently, abbreviations are only available 'in' a target locale, but
  2662 not inherited by general import expressions.  Also note that
  2663 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2664 'translations' in common applications.  The "no_abbrevs" print mode
  2665 prevents folding of abbreviations in term output.
  2666 
  2667 Concrete syntax is attached to specified constants in internal form,
  2668 independently of name spaces.  The parse tree representation is
  2669 slightly different -- use 'notation' instead of raw 'syntax', and
  2670 'translations' with explicit "CONST" markup to accommodate this.
  2671 
  2672 * Pure/Isar: unified syntax for new-style specification mechanisms
  2673 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2674 full type inference and dummy patterns ("_").  For example:
  2675 
  2676   definition "K x _ = x"
  2677 
  2678   inductive conj for A B
  2679   where "A ==> B ==> conj A B"
  2680 
  2681 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2682 the current context.  Print mode "no_abbrevs" prevents inversion of
  2683 abbreviations on output.
  2684 
  2685 * Isar/locales: improved parameter handling: use of locales "var" and
  2686 "struct" no longer necessary; - parameter renamings are no longer
  2687 required to be injective.  For example, this allows to define
  2688 endomorphisms as locale endom = homom mult mult h.
  2689 
  2690 * Isar/locales: changed the way locales with predicates are defined.
  2691 Instead of accumulating the specification, the imported expression is
  2692 now an interpretation.  INCOMPATIBILITY: different normal form of
  2693 locale expressions.  In particular, in interpretations of locales with
  2694 predicates, goals repesenting already interpreted fragments are not
  2695 removed automatically.  Use methods `intro_locales' and
  2696 `unfold_locales'; see below.
  2697 
  2698 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2699 provide backward reasoning on locales predicates.  The methods are
  2700 aware of interpretations and discharge corresponding goals.
  2701 `intro_locales' is less aggressive then `unfold_locales' and does not
  2702 unfold predicates to assumptions.
  2703 
  2704 * Isar/locales: the order in which locale fragments are accumulated
  2705 has changed.  This enables to override declarations from fragments due
  2706 to interpretations -- for example, unwanted simp rules.
  2707 
  2708 * Isar/locales: interpretation in theories and proof contexts has been
  2709 extended.  One may now specify (and prove) equations, which are
  2710 unfolded in interpreted theorems.  This is useful for replacing
  2711 defined concepts (constants depending on locale parameters) by
  2712 concepts already existing in the target context.  Example:
  2713 
  2714   interpretation partial_order ["op <= :: [int, int] => bool"]
  2715     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2716 
  2717 Typically, the constant `partial_order.less' is created by a
  2718 definition specification element in the context of locale
  2719 partial_order.
  2720 
  2721 * Method "induct": improved internal context management to support
  2722 local fixes and defines on-the-fly. Thus explicit meta-level
  2723 connectives !!  and ==> are rarely required anymore in inductive goals
  2724 (using object-logic connectives for this purpose has been long
  2725 obsolete anyway). Common proof patterns are explained in
  2726 src/HOL/Induct/Common_Patterns.thy, see also
  2727 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2728 examples.
  2729 
  2730 * Method "induct": improved handling of simultaneous goals. Instead of
  2731 introducing object-level conjunction, the statement is now split into
  2732 several conclusions, while the corresponding symbolic cases are nested
  2733 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2734 see src/HOL/Induct/Common_Patterns.thy, for example.
  2735 
  2736 * Method "induct": mutual induction rules are now specified as a list
  2737 of rule sharing the same induction cases. HOL packages usually provide
  2738 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2739 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2740 mutual induction rules differently, i.e. like this:
  2741 
  2742   (induct rule: foo_bar.inducts)
  2743   (induct set: foo bar)
  2744   (induct pred: foo bar)
  2745   (induct type: foo bar)
  2746 
  2747 The ML function ProjectRule.projections turns old-style rules into the
  2748 new format.
  2749 
  2750 * Method "coinduct": dual of induction, see
  2751 src/HOL/Library/Coinductive_List.thy for various examples.
  2752 
  2753 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2754 considered a legacy feature.
  2755 
  2756 * Attribute "symmetric" produces result with standardized schematic
  2757 variables (index 0).  Potential INCOMPATIBILITY.
  2758 
  2759 * Simplifier: by default the simplifier trace only shows top level
  2760 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2761 default. Thus there is less danger of being flooded by the trace. The
  2762 trace indicates where parts have been suppressed.
  2763   
  2764 * Provers/classical: removed obsolete classical version of elim_format
  2765 attribute; classical elim/dest rules are now treated uniformly when
  2766 manipulating the claset.
  2767 
  2768 * Provers/classical: stricter checks to ensure that supplied intro,
  2769 dest and elim rules are well-formed; dest and elim rules must have at
  2770 least one premise.
  2771 
  2772 * Provers/classical: attributes dest/elim/intro take an optional
  2773 weight argument for the rule (just as the Pure versions).  Weights are
  2774 ignored by automated tools, but determine the search order of single
  2775 rule steps.
  2776 
  2777 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2778 where the body does not mention the bound variable.  Note that dummy
  2779 patterns implicitly depend on their context of bounds, which makes
  2780 "{_. _}" match any set comprehension as expected.  Potential
  2781 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2782 constant "_idtdummy" in the binding position.
  2783 
  2784 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2785 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2786 for example "A -> B" => "Pi A (%_. B)".
  2787 
  2788 * Pure: 'class_deps' command visualizes the subclass relation, using
  2789 the graph browser tool.
  2790 
  2791 * Pure: 'print_theory' now suppresses certain internal declarations by
  2792 default; use '!' option for full details.
  2793 
  2794 
  2795 *** HOL ***
  2796 
  2797 * Method "metis" proves goals by applying the Metis general-purpose
  2798 resolution prover (see also http://gilith.com/software/metis/).
  2799 Examples are in the directory MetisExamples.  WARNING: the
  2800 Isabelle/HOL-Metis integration does not yet work properly with
  2801 multi-threading.
  2802   
  2803 * Command 'sledgehammer' invokes external automatic theorem provers as
  2804 background processes.  It generates calls to the "metis" method if
  2805 successful. These can be pasted into the proof.  Users do not have to
  2806 wait for the automatic provers to return.  WARNING: does not really
  2807 work with multi-threading.
  2808 
  2809 * New "auto_quickcheck" feature tests outermost goal statements for
  2810 potential counter-examples.  Controlled by ML references
  2811 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2812 5000 milliseconds).  Fails silently if statements is outside of
  2813 executable fragment, or any other codgenerator problem occurs.
  2814 
  2815 * New constant "undefined" with axiom "undefined x = undefined".
  2816 
  2817 * Added class "HOL.eq", allowing for code generation with polymorphic
  2818 equality.
  2819 
  2820 * Some renaming of class constants due to canonical name prefixing in
  2821 the new 'class' package:
  2822 
  2823     HOL.abs ~> HOL.abs_class.abs
  2824     HOL.divide ~> HOL.divide_class.divide
  2825     0 ~> HOL.zero_class.zero
  2826     1 ~> HOL.one_class.one
  2827     op + ~> HOL.plus_class.plus
  2828     op - ~> HOL.minus_class.minus
  2829     uminus ~> HOL.minus_class.uminus
  2830     op * ~> HOL.times_class.times
  2831     op < ~> HOL.ord_class.less
  2832     op <= > HOL.ord_class.less_eq
  2833     Nat.power ~> Power.power_class.power
  2834     Nat.size ~> Nat.size_class.size
  2835     Numeral.number_of ~> Numeral.number_class.number_of
  2836     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2837     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2838     Orderings.min ~> Orderings.ord_class.min
  2839     Orderings.max ~> Orderings.ord_class.max
  2840     Divides.op div ~> Divides.div_class.div
  2841     Divides.op mod ~> Divides.div_class.mod
  2842     Divides.op dvd ~> Divides.div_class.dvd
  2843 
  2844 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2845 
  2846 a) User-defined constants using any of the names "plus", "minus",
  2847 "times", "less" or "less_eq". The standard syntax translations for
  2848 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2849 names.
  2850 
  2851 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2852 INCOMPATIBILITY: use more specific names.
  2853 
  2854 c) Permutative equations (e.g. "a + b = b + a")
  2855 Since the change of names also changes the order of terms, permutative
  2856 rewrite rules may get applied in a different order. Experience shows
  2857 that this is rarely the case (only two adaptions in the whole Isabelle
  2858 distribution).  INCOMPATIBILITY: rewrite proofs
  2859 
  2860 d) ML code directly refering to constant names
  2861 This in general only affects hand-written proof tactics, simprocs and
  2862 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2863 Consider using @{const_name} antiquotation.
  2864 
  2865 * New class "default" with associated constant "default".
  2866 
  2867 * Function "sgn" is now overloaded and available on int, real, complex
  2868 (and other numeric types), using class "sgn".  Two possible defs of
  2869 sgn are given as equational assumptions in the classes sgn_if and
  2870 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2871 INCOMPATIBILITY.
  2872 
  2873 * Locale "partial_order" now unified with class "order" (cf. theory
  2874 Orderings), added parameter "less".  INCOMPATIBILITY.
  2875 
  2876 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2877 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2878 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2879 
  2880 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2881 changed order of proof goals in instance proofs.
  2882 
  2883 * The transitivity reasoner for partial and linear orders is set up
  2884 for classes "order" and "linorder".  Instances of the reasoner are available
  2885 in all contexts importing or interpreting the corresponding locales.
  2886 Method "order" invokes the reasoner separately; the reasoner
  2887 is also integrated with the Simplifier as a solver.  Diagnostic
  2888 command 'print_orders' shows the available instances of the reasoner
  2889 in the current context.
  2890 
  2891 * Localized monotonicity predicate in theory "Orderings"; integrated
  2892 lemmas max_of_mono and min_of_mono with this predicate.
  2893 INCOMPATIBILITY.
  2894 
  2895 * Formulation of theorem "dense" changed slightly due to integration
  2896 with new class dense_linear_order.
  2897 
  2898 * Uniform lattice theory development in HOL.
  2899 
  2900     constants "meet" and "join" now named "inf" and "sup"
  2901     constant "Meet" now named "Inf"
  2902 
  2903     classes "meet_semilorder" and "join_semilorder" now named
  2904       "lower_semilattice" and "upper_semilattice"
  2905     class "lorder" now named "lattice"
  2906     class "comp_lat" now named "complete_lattice"
  2907 
  2908     Instantiation of lattice classes allows explicit definitions
  2909     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2910 
  2911   INCOMPATIBILITY.  Theorem renames:
  2912 
  2913     meet_left_le            ~> inf_le1
  2914     meet_right_le           ~> inf_le2
  2915     join_left_le            ~> sup_ge1
  2916     join_right_le           ~> sup_ge2
  2917     meet_join_le            ~> inf_sup_ord
  2918     le_meetI                ~> le_infI
  2919     join_leI                ~> le_supI
  2920     le_meet                 ~> le_inf_iff
  2921     le_join                 ~> ge_sup_conv
  2922     meet_idempotent         ~> inf_idem
  2923     join_idempotent         ~> sup_idem
  2924     meet_comm               ~> inf_commute
  2925     join_comm               ~> sup_commute
  2926     meet_leI1               ~> le_infI1
  2927     meet_leI2               ~> le_infI2
  2928     le_joinI1               ~> le_supI1
  2929     le_joinI2               ~> le_supI2
  2930     meet_assoc              ~> inf_assoc
  2931     join_assoc              ~> sup_assoc
  2932     meet_left_comm          ~> inf_left_commute
  2933     meet_left_idempotent    ~> inf_left_idem
  2934     join_left_comm          ~> sup_left_commute
  2935     join_left_idempotent    ~> sup_left_idem
  2936     meet_aci                ~> inf_aci
  2937     join_aci                ~> sup_aci
  2938     le_def_meet             ~> le_iff_inf
  2939     le_def_join             ~> le_iff_sup
  2940     join_absorp2            ~> sup_absorb2
  2941     join_absorp1            ~> sup_absorb1
  2942     meet_absorp1            ~> inf_absorb1
  2943     meet_absorp2            ~> inf_absorb2
  2944     meet_join_absorp        ~> inf_sup_absorb
  2945     join_meet_absorp        ~> sup_inf_absorb
  2946     distrib_join_le         ~> distrib_sup_le
  2947     distrib_meet_le         ~> distrib_inf_le
  2948 
  2949     add_meet_distrib_left   ~> add_inf_distrib_left
  2950     add_join_distrib_left   ~> add_sup_distrib_left
  2951     is_join_neg_meet        ~> is_join_neg_inf
  2952     is_meet_neg_join        ~> is_meet_neg_sup
  2953     add_meet_distrib_right  ~> add_inf_distrib_right
  2954     add_join_distrib_right  ~> add_sup_distrib_right
  2955     add_meet_join_distribs  ~> add_sup_inf_distribs
  2956     join_eq_neg_meet        ~> sup_eq_neg_inf
  2957     meet_eq_neg_join        ~> inf_eq_neg_sup
  2958     add_eq_meet_join        ~> add_eq_inf_sup
  2959     meet_0_imp_0            ~> inf_0_imp_0
  2960     join_0_imp_0            ~> sup_0_imp_0
  2961     meet_0_eq_0             ~> inf_0_eq_0
  2962     join_0_eq_0             ~> sup_0_eq_0
  2963     neg_meet_eq_join        ~> neg_inf_eq_sup
  2964     neg_join_eq_meet        ~> neg_sup_eq_inf
  2965     join_eq_if              ~> sup_eq_if
  2966 
  2967     mono_meet               ~> mono_inf
  2968     mono_join               ~> mono_sup
  2969     meet_bool_eq            ~> inf_bool_eq
  2970     join_bool_eq            ~> sup_bool_eq
  2971     meet_fun_eq             ~> inf_fun_eq
  2972     join_fun_eq             ~> sup_fun_eq
  2973     meet_set_eq             ~> inf_set_eq
  2974     join_set_eq             ~> sup_set_eq
  2975     meet1_iff               ~> inf1_iff
  2976     meet2_iff               ~> inf2_iff
  2977     meet1I                  ~> inf1I
  2978     meet2I                  ~> inf2I
  2979     meet1D1                 ~> inf1D1
  2980     meet2D1                 ~> inf2D1
  2981     meet1D2                 ~> inf1D2
  2982     meet2D2                 ~> inf2D2
  2983     meet1E                  ~> inf1E
  2984     meet2E                  ~> inf2E
  2985     join1_iff               ~> sup1_iff
  2986     join2_iff               ~> sup2_iff
  2987     join1I1                 ~> sup1I1
  2988     join2I1                 ~> sup2I1
  2989     join1I1                 ~> sup1I1
  2990     join2I2                 ~> sup1I2
  2991     join1CI                 ~> sup1CI
  2992     join2CI                 ~> sup2CI
  2993     join1E                  ~> sup1E
  2994     join2E                  ~> sup2E
  2995 
  2996     is_meet_Meet            ~> is_meet_Inf
  2997     Meet_bool_def           ~> Inf_bool_def
  2998     Meet_fun_def            ~> Inf_fun_def
  2999     Meet_greatest           ~> Inf_greatest
  3000     Meet_lower              ~> Inf_lower
  3001     Meet_set_def            ~> Inf_set_def
  3002 
  3003     Sup_def                 ~> Sup_Inf
  3004     Sup_bool_eq             ~> Sup_bool_def
  3005     Sup_fun_eq              ~> Sup_fun_def
  3006     Sup_set_eq              ~> Sup_set_def
  3007 
  3008     listsp_meetI            ~> listsp_infI
  3009     listsp_meet_eq          ~> listsp_inf_eq
  3010 
  3011     meet_min                ~> inf_min
  3012     join_max                ~> sup_max
  3013 
  3014 * Added syntactic class "size"; overloaded constant "size" now has
  3015 type "'a::size ==> bool"
  3016 
  3017 * Internal reorganisation of `size' of datatypes: size theorems
  3018 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3019 simplification rules by default!); theorems "prod.size" now named
  3020 "*.size".
  3021 
  3022 * Class "div" now inherits from class "times" rather than "type".
  3023 INCOMPATIBILITY.
  3024 
  3025 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3026 Linorder etc.  have disappeared; operations defined in terms of
  3027 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3028 
  3029 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3030 
  3031 * HOL-Word: New extensive library and type for generic, fixed size
  3032 machine words, with arithemtic, bit-wise, shifting and rotating
  3033 operations, reflection into int, nat, and bool lists, automation for
  3034 linear arithmetic (by automatic reflection into nat or int), including
  3035 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3036 arithmetic type classes, supporting automatic simplification of
  3037 numerals on all operations.
  3038 
  3039 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3040 
  3041 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3042 
  3043 * Code generator library theories:
  3044   - Code_Integer represents HOL integers by big integer literals in target
  3045     languages.
  3046   - Code_Char represents HOL characters by character literals in target
  3047     languages.
  3048   - Code_Char_chr like Code_Char, but also offers treatment of character
  3049     codes; includes Code_Integer.
  3050   - Executable_Set allows to generate code for finite sets using lists.
  3051   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3052     denominator).
  3053   - Executable_Real implements a subset of real numbers, namly those
  3054     representable by rational numbers.
  3055   - Efficient_Nat implements natural numbers by integers, which in general will
  3056     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3057     includes Code_Integer.
  3058   - Code_Index provides an additional datatype index which is mapped to
  3059     target-language built-in integers.
  3060   - Code_Message provides an additional datatype message_string which is isomorphic to
  3061     strings; messages are mapped to target-language strings.
  3062 
  3063 * New package for inductive predicates
  3064 
  3065   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3066 
  3067     inductive
  3068       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3069       for z_1 :: U_1 and ... and z_n :: U_m
  3070     where
  3071       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3072     | ...
  3073 
  3074   with full support for type-inference, rather than
  3075 
  3076     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3077 
  3078     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3079     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3080 
  3081     inductive "s z_1 ... z_m"
  3082     intros
  3083       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3084       ...
  3085 
  3086   For backward compatibility, there is a wrapper allowing inductive
  3087   sets to be defined with the new package via
  3088 
  3089     inductive_set
  3090       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3091       for z_1 :: U_1 and ... and z_n :: U_m
  3092     where
  3093       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3094     | ...
  3095 
  3096   or
  3097 
  3098     inductive_set
  3099       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3100       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3101       for z_1 :: U_1 and ... and z_n :: U_m
  3102     where
  3103       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3104     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3105     | ...
  3106 
  3107   if the additional syntax "p ..." is required.
  3108 
  3109   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3110   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3111 
  3112   INCOMPATIBILITIES:
  3113 
  3114   - Since declaration and definition of inductive sets or predicates
  3115     is no longer separated, abbreviations involving the newly
  3116     introduced sets or predicates must be specified together with the
  3117     introduction rules after the 'where' keyword (see above), rather
  3118     than before the actual inductive definition.
  3119 
  3120   - The variables in induction and elimination rules are now
  3121     quantified in the order of their occurrence in the introduction
  3122     rules, rather than in alphabetical order. Since this may break
  3123     some proofs, these proofs either have to be repaired, e.g. by
  3124     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3125     statements of the form
  3126 
  3127       case (rule_i a_i_1 ... a_i_{k_i})
  3128 
  3129     or the old order of quantification has to be restored by explicitly adding
  3130     meta-level quantifiers in the introduction rules, i.e.
  3131 
  3132       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3133 
  3134   - The format of the elimination rules is now
  3135 
  3136       p z_1 ... z_m x_1 ... x_n ==>
  3137         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3138         ==> ... ==> P
  3139 
  3140     for predicates and
  3141 
  3142       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3143         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3144         ==> ... ==> P
  3145 
  3146     for sets rather than
  3147 
  3148       x : s z_1 ... z_m ==>
  3149         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3150         ==> ... ==> P
  3151 
  3152     This may require terms in goals to be expanded to n-tuples
  3153     (e.g. using case_tac or simplification with the split_paired_all
  3154     rule) before the above elimination rule is applicable.
  3155 
  3156   - The elimination or case analysis rules for (mutually) inductive
  3157     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3158     list of rules "p_1_..._p_k.elims" is no longer available.
  3159 
  3160 * New package "function"/"fun" for general recursive functions,
  3161 supporting mutual and nested recursion, definitions in local contexts,
  3162 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3163 for small examples, and the separate tutorial on the function
  3164 package. The old recdef "package" is still available as before, but
  3165 users are encouraged to use the new package.
  3166 
  3167 * Method "lexicographic_order" automatically synthesizes termination
  3168 relations as lexicographic combinations of size measures. 
  3169 
  3170 * Case-expressions allow arbitrary constructor-patterns (including
  3171 "_") and take their order into account, like in functional
  3172 programming.  Internally, this is translated into nested
  3173 case-expressions; missing cases are added and mapped to the predefined
  3174 constant "undefined". In complicated cases printing may no longer show
  3175 the original input but the internal form. Lambda-abstractions allow
  3176 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3177 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3178 variable.
  3179 
  3180 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3181 is an abbreviation for "of_nat :: nat => int". The simplification
  3182 rules for "of_nat" have been changed to work like "int" did
  3183 previously.  Potential INCOMPATIBILITY:
  3184   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3185   - of_nat_diff and of_nat_mult are no longer default simp rules
  3186 
  3187 * Method "algebra" solves polynomial equations over (semi)rings using
  3188 Groebner bases. The (semi)ring structure is defined by locales and the
  3189 tool setup depends on that generic context. Installing the method for
  3190 a specific type involves instantiating the locale and possibly adding
  3191 declarations for computation on the coefficients.  The method is
  3192 already instantiated for natural numbers and for the axiomatic class
  3193 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3194 CALCULEMUS 2007 for the general principles underlying this
  3195 architecture of context-aware proof-tools.
  3196 
  3197 * Method "ferrack" implements quantifier elimination over
  3198 special-purpose dense linear orders using locales (analogous to
  3199 "algebra"). The method is already installed for class
  3200 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3201 rat, etc.
  3202 
  3203 * Former constant "List.op @" now named "List.append".  Use ML
  3204 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3205 circumvent possible incompatibilities when working on ML level.
  3206 
  3207 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3208 
  3209 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3210 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3211 
  3212 * New syntax for Haskell-like list comprehension (input only), eg.
  3213 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3214 
  3215 * The special syntax for function "filter" has changed from [x :
  3216 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3217 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3218 
  3219 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3220 defined on nat only, as an abbreviation for [a..<Suc b]
  3221 INCOMPATIBILITY.
  3222 
  3223 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3224 
  3225 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3226 
  3227 * New lemma collection field_simps (an extension of ring_simps) for
  3228 manipulating (in)equations involving division. Multiplies with all
  3229 denominators that can be proved to be non-zero (in equations) or
  3230 positive/negative (in inequations).
  3231 
  3232 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3233 have been improved and renamed to ring_simps, group_simps and
  3234 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3235 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3236 
  3237 * Theory Library/Commutative_Ring: switched from recdef to function
  3238 package; constants add, mul, pow now curried.  Infix syntax for
  3239 algebraic operations.
  3240 
  3241 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3242 INCOMPATIBILITY.
  3243 
  3244 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3245 INCOMPATIBILITY.
  3246 
  3247 * HOL/records: generalised field-update to take a function on the
  3248 field rather than the new value: r(|A := x|) is translated to A_update
  3249 (K x) r The K-combinator that is internally used is called K_record.
  3250 INCOMPATIBILITY: Usage of the plain update functions has to be
  3251 adapted.
  3252  
  3253 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3254 * x = 0, which are required for a semiring.  Richer structures do not
  3255 inherit from semiring_0 anymore, because this property is a theorem
  3256 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3257 there is more to prove, but this is mostly trivial.
  3258 
  3259 * Class "recpower" is generalized to arbitrary monoids, not just
  3260 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3261 commutativity or semiring properties additionally.
  3262 
  3263 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3264 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3265 better use 'abbreviation'.
  3266 
  3267 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3268 
  3269 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3270 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3271 significant changes for setting up numeral syntax for types:
  3272   - New constants Numeral.pred and Numeral.succ instead
  3273       of former Numeral.bin_pred and Numeral.bin_succ.
  3274   - Use integer operations instead of bin_add, bin_mult and so on.
  3275   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3276   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3277 
  3278 See src/HOL/Integ/IntArith.thy for an example setup.
  3279 
  3280 * Command 'normal_form' computes the normal form of a term that may
  3281 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3282 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3283 heavy-duty computations because the functions are compiled to ML
  3284 first.  Correspondingly, a method "normalization" is provided.  See
  3285 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3286 
  3287 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3288 25 like -->); output depends on the "iff" print_mode, the default is
  3289 "A = B" (with priority 50).
  3290 
  3291 * Relations less (<) and less_eq (<=) are also available on type bool.
  3292 Modified syntax to disallow nesting without explicit parentheses,
  3293 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3294 INCOMPATIBILITY.
  3295 
  3296 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3297 
  3298 * Relation composition operator "op O" now has precedence 75 and binds
  3299 stronger than union and intersection. INCOMPATIBILITY.
  3300 
  3301 * The old set interval syntax "{m..n(}" (and relatives) has been
  3302 removed.  Use "{m..<n}" (and relatives) instead.
  3303 
  3304 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3305 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3306 ``declare [[simproc del: neq]]''.
  3307 
  3308 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3309 True/False.
  3310 
  3311 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3312 
  3313 * Theorem setsum_mult renamed to setsum_right_distrib.
  3314 
  3315 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3316 ``rule'' method.
  3317 
  3318 * Reimplemented methods "sat" and "satx", with several improvements:
  3319 goals no longer need to be stated as "<prems> ==> False", equivalences
  3320 (i.e. "=" on type bool) are handled, variable names of the form
  3321 "lit_<n>" are no longer reserved, significant speedup.
  3322 
  3323 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3324 zChaff is still supported as well.
  3325 
  3326 * 'inductive' and 'datatype': provide projections of mutual rules,
  3327 bundled as foo_bar.inducts;
  3328 
  3329 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3330 Library.
  3331 
  3332 * Library: moved theory Accessible_Part to main HOL.
  3333 
  3334 * Library: added theory Coinductive_List of potentially infinite lists
  3335 as greatest fixed-point.
  3336 
  3337 * Library: added theory AssocList which implements (finite) maps as
  3338 association lists.
  3339 
  3340 * Method "evaluation" solves goals (i.e. a boolean expression)
  3341 efficiently by compiling it to ML.  The goal is "proved" (via an
  3342 oracle) if it evaluates to True.
  3343 
  3344 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3345 also when invoked by the simplifier.  This results in the Simplifier
  3346 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3347 Configuration option fast_arith_split_limit=0 recovers the old
  3348 behavior.
  3349 
  3350 * Support for hex (0x20) and binary (0b1001) numerals.
  3351 
  3352 * New method: reify eqs (t), where eqs are equations for an
  3353 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3354 parameter, computes a term s::'b and a list xs::'a list and proves the
  3355 theorem I xs s = t. This is also known as reification or quoting. The
  3356 resulting theorem is applied to the subgoal to substitute t with I xs
  3357 s.  If t is omitted, the subgoal itself is reified.
  3358 
  3359 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3360 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3361 where f is supposed to be a computable function (in the sense of code
  3362 generattion). The method uses reify to compute s and xs as above then
  3363 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3364 r and finally gets the theorem t = r, which is again applied to the
  3365 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3366 
  3367 * Reflection: Automatic reification now handels binding, an example is
  3368 available in src/HOL/ex/ReflectionEx.thy
  3369 
  3370 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3371 command 'statespace' that is similar to 'record', but introduces an
  3372 abstract specification based on the locale infrastructure instead of
  3373 HOL types.  This leads to extra flexibility in composing state spaces,
  3374 in particular multiple inheritance and renaming of components.
  3375 
  3376 
  3377 *** HOL-Complex ***
  3378 
  3379 * Hyperreal: Functions root and sqrt are now defined on negative real
  3380 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3381 Nonnegativity side conditions have been removed from many lemmas, so
  3382 that more subgoals may now be solved by simplification; potential
  3383 INCOMPATIBILITY.
  3384 
  3385 * Real: new type classes formalize real normed vector spaces and
  3386 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3387 and norm :: 'a => real.
  3388 
  3389 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3390 reals into other types. The overloaded constant Reals :: 'a set is now
  3391 defined as range of_real; potential INCOMPATIBILITY.
  3392 
  3393 * Real: proper support for ML code generation, including 'quickcheck'.
  3394 Reals are implemented as arbitrary precision rationals.
  3395 
  3396 * Real: new development using Cauchy Sequences.
  3397 
  3398 * Hyperreal: Several constants that previously worked only for the
  3399 reals have been generalized, so they now work over arbitrary vector
  3400 spaces. Type annotations may need to be added in some cases; potential
  3401 INCOMPATIBILITY.
  3402 
  3403   Infinitesimal  :: ('a::real_normed_vector) star set
  3404   HFinite        :: ('a::real_normed_vector) star set
  3405   HInfinite      :: ('a::real_normed_vector) star set
  3406   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3407   monad          :: ('a::real_normed_vector) star => 'a star set
  3408   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3409   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3410   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3411   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3412   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3413   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3414   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3415   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3416   sgn            :: 'a::real_normed_vector => 'a
  3417   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3418 
  3419 * Complex: Some complex-specific constants are now abbreviations for
  3420 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3421 hnorm.  Other constants have been entirely removed in favor of the
  3422 polymorphic versions (INCOMPATIBILITY):
  3423 
  3424   approx        <-- capprox
  3425   HFinite       <-- CFinite
  3426   HInfinite     <-- CInfinite
  3427   Infinitesimal <-- CInfinitesimal
  3428   monad         <-- cmonad
  3429   galaxy        <-- cgalaxy
  3430   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3431   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3432   (ns)deriv     <-- (ns)cderiv
  3433 
  3434 
  3435 *** HOL-Algebra ***
  3436 
  3437 * Formalisation of ideals and the quotient construction over rings.
  3438 
  3439 * Order and lattice theory no longer based on records.
  3440 INCOMPATIBILITY.
  3441 
  3442 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3443 greatest_closed.  INCOMPATIBILITY.
  3444 
  3445 * Method algebra is now set up via an attribute.  For examples see
  3446 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3447 of algebraic structures.
  3448 
  3449 * Renamed theory CRing to Ring.
  3450 
  3451 
  3452 *** HOL-Nominal ***
  3453 
  3454 * Substantial, yet incomplete support for nominal datatypes (binding
  3455 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3456 src/HOL/Nominal/Examples.  Prospective users should consult
  3457 http://isabelle.in.tum.de/nominal/
  3458 
  3459 
  3460 *** ML ***
  3461 
  3462 * ML basics: just one true type int, which coincides with IntInf.int
  3463 (even on SML/NJ).
  3464 
  3465 * ML within Isar: antiquotations allow to embed statically-checked
  3466 formal entities in the source, referring to the context available at
  3467 compile-time.  For example:
  3468 
  3469 ML {* @{sort "{zero,one}"} *}
  3470 ML {* @{typ "'a => 'b"} *}
  3471 ML {* @{term "%x. x"} *}
  3472 ML {* @{prop "x == y"} *}
  3473 ML {* @{ctyp "'a => 'b"} *}
  3474 ML {* @{cterm "%x. x"} *}
  3475 ML {* @{cprop "x == y"} *}
  3476 ML {* @{thm asm_rl} *}
  3477 ML {* @{thms asm_rl} *}
  3478 ML {* @{type_name c} *}
  3479 ML {* @{type_syntax c} *}
  3480 ML {* @{const_name c} *}
  3481 ML {* @{const_syntax c} *}
  3482 ML {* @{context} *}
  3483 ML {* @{theory} *}
  3484 ML {* @{theory Pure} *}
  3485 ML {* @{theory_ref} *}
  3486 ML {* @{theory_ref Pure} *}
  3487 ML {* @{simpset} *}
  3488 ML {* @{claset} *}
  3489 ML {* @{clasimpset} *}
  3490 
  3491 The same works for sources being ``used'' within an Isar context.
  3492 
  3493 * ML in Isar: improved error reporting; extra verbosity with
  3494 ML_Context.trace enabled.
  3495 
  3496 * Pure/General/table.ML: the join operations now works via exceptions
  3497 DUP/SAME instead of type option. This is simpler in simple cases, and
  3498 admits slightly more efficient complex applications.
  3499 
  3500 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3501 use Context.generic instead of just theory.
  3502 
  3503 * Pure: datatype Context.generic joins theory/Proof.context and
  3504 provides some facilities for code that works in either kind of
  3505 context, notably GenericDataFun for uniform theory and proof data.
  3506 
  3507 * Pure: simplified internal attribute type, which is now always
  3508 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3509 local (Proof.context) attributes have been discontinued, while
  3510 minimizing code duplication. Thm.rule_attribute and
  3511 Thm.declaration_attribute build canonical attributes; see also structure
  3512 Context for further operations on Context.generic, notably
  3513 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3514 declarations and definitions.
  3515 
  3516 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3517 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3518 init only required for impure data. INCOMPATIBILITY: empty really need
  3519 to be empty (no dependencies on theory content!)
  3520 
  3521 * Pure/kernel: consts certification ignores sort constraints given in
  3522 signature declarations. (This information is not relevant to the
  3523 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3524 potential INCOMPATIBILITY.
  3525 
  3526 * Pure: axiomatic type classes are now purely definitional, with
  3527 explicit proofs of class axioms and super class relations performed
  3528 internally. See Pure/axclass.ML for the main internal interfaces --
  3529 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3530 AxClass.axiomatize_class/classrel/arity supersede
  3531 Sign.add_classes/classrel/arities.
  3532 
  3533 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3534 global/local versions on theory vs. Proof.context have been
  3535 discontinued; Attrib.syntax and Method.syntax have been adapted
  3536 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3537 attributes, methods, etc.
  3538 
  3539 * Pure: several functions of signature "... -> theory -> theory * ..."
  3540 have been reoriented to "... -> theory -> ... * theory" in order to
  3541 allow natural usage in combination with the ||>, ||>>, |-> and
  3542 fold_map combinators.
  3543 
  3544 * Pure: official theorem names (closed derivations) and additional
  3545 comments (tags) are now strictly separate.  Name hints -- which are
  3546 maintained as tags -- may be attached any time without affecting the
  3547 derivation.
  3548 
  3549 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3550 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3551 achieve the old behaviour.
  3552 
  3553 * Pure: the "Goal" constant is now called "prop", supporting a
  3554 slightly more general idea of ``protecting'' meta-level rule
  3555 statements.
  3556 
  3557 * Pure: Logic.(un)varify only works in a global context, which is now
  3558 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3559 Logic.legacy_(un)varify as temporary workaround.
  3560 
  3561 * Pure: structure Name provides scalable operations for generating
  3562 internal variable names, notably Name.variants etc.  This replaces
  3563 some popular functions from term.ML:
  3564 
  3565   Term.variant		->  Name.variant
  3566   Term.variantlist	->  Name.variant_list
  3567   Term.invent_names	->  Name.invent_list
  3568 
  3569 Note that low-level renaming rarely occurs in new code -- operations
  3570 from structure Variable are used instead (see below).
  3571 
  3572 * Pure: structure Variable provides fundamental operations for proper
  3573 treatment of fixed/schematic variables in a context.  For example,
  3574 Variable.import introduces fixes for schematics of given facts and
  3575 Variable.export reverses the effect (up to renaming) -- this replaces
  3576 various freeze_thaw operations.
  3577 
  3578 * Pure: structure Goal provides simple interfaces for
  3579 init/conclude/finish and tactical prove operations (replacing former
  3580 Tactic.prove).  Goal.prove is the canonical way to prove results
  3581 within a given context; Goal.prove_global is a degraded version for
  3582 theory level goals, including a global Drule.standard.  Note that
  3583 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3584 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3585 in a locale context).
  3586 
  3587 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3588 and type checking (Syntax.check_term etc.), with common combinations
  3589 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3590 which are considered legacy and await removal.
  3591 
  3592 * Pure/Syntax: generic interfaces for type unchecking
  3593 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3594 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3595 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3596 available for convenience, but refer to the very same operations using
  3597 a mere theory instead of a full context.
  3598 
  3599 * Isar: simplified treatment of user-level errors, using exception
  3600 ERROR of string uniformly.  Function error now merely raises ERROR,
  3601 without any side effect on output channels.  The Isar toplevel takes
  3602 care of proper display of ERROR exceptions.  ML code may use plain
  3603 handle/can/try; cat_error may be used to concatenate errors like this:
  3604 
  3605   ... handle ERROR msg => cat_error msg "..."
  3606 
  3607 Toplevel ML code (run directly or through the Isar toplevel) may be
  3608 embedded into the Isar toplevel with exception display/debug like
  3609 this:
  3610 
  3611   Isar.toplevel (fn () => ...)
  3612 
  3613 INCOMPATIBILITY, removed special transform_error facilities, removed
  3614 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3615 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3616 -- use plain ERROR instead.
  3617 
  3618 * Isar: theory setup now has type (theory -> theory), instead of a
  3619 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3620 
  3621 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3622 ProofContext.debug/verbose flags.
  3623 
  3624 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3625 theory before entering a proof state.  Transactions now always see a
  3626 quasi-functional intermediate checkpoint, both in interactive and
  3627 batch mode.
  3628 
  3629 * Isar: simplified interfaces for outer syntax.  Renamed
  3630 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3631 OuterSyntax.add_parsers -- this functionality is now included in
  3632 OuterSyntax.command etc.  INCOMPATIBILITY.
  3633 
  3634 * Simplifier: the simpset of a running simplification process now
  3635 contains a proof context (cf. Simplifier.the_context), which is the
  3636 very context that the initial simpset has been retrieved from (by
  3637 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3638 (solver, looper etc.) may depend on arbitrary proof data.
  3639 
  3640 * Simplifier.inherit_context inherits the proof context (plus the
  3641 local bounds) of the current simplification process; any simproc
  3642 etc. that calls the Simplifier recursively should do this!  Removed
  3643 former Simplifier.inherit_bounds, which is already included here --
  3644 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3645 specify an explicit context using Simplifier.context/theory_context.
  3646 
  3647 * Simplifier/Classical Reasoner: more abstract interfaces
  3648 change_simpset/claset for modifying the simpset/claset reference of a
  3649 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3650 INCOMPATIBILITY.
  3651 
  3652 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3653 "Trueprop" etc.
  3654 
  3655 
  3656 *** System ***
  3657 
  3658 * settings: the default heap location within ISABELLE_HOME_USER now
  3659 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3660 Isabelle installations.
  3661 
  3662 * isabelle-process: option -S (secure mode) disables some critical
  3663 operations, notably runtime compilation and evaluation of ML source
  3664 code.
  3665 
  3666 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3667 
  3668 * Support for parallel execution, using native multicore support of
  3669 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3670 independent theories, according to the given theory header
  3671 specifications. The maximum number of worker threads is specified via
  3672 usedir option -M or the "max-threads" setting in Proof General. A
  3673 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3674 to 6 on a 8-core machine.  User-code needs to observe certain
  3675 guidelines for thread-safe programming, see appendix A in the Isar
  3676 Implementation manual.
  3677 
  3678 
  3679 
  3680 New in Isabelle2005 (October 2005)
  3681 ----------------------------------
  3682 
  3683 *** General ***
  3684 
  3685 * Theory headers: the new header syntax for Isar theories is
  3686 
  3687   theory <name>
  3688   imports <theory1> ... <theoryN>
  3689   uses <file1> ... <fileM>
  3690   begin
  3691 
  3692 where the 'uses' part is optional.  The previous syntax
  3693 
  3694   theory <name> = <theory1> + ... + <theoryN>:
  3695 
  3696 will disappear in the next release.  Use isatool fixheaders to convert
  3697 existing theory files.  Note that there is no change in ancient
  3698 non-Isar theories now, but these will disappear soon.
  3699 
  3700 * Theory loader: parent theories can now also be referred to via
  3701 relative and absolute paths.
  3702 
  3703 * Command 'find_theorems' searches for a list of criteria instead of a
  3704 list of constants. Known criteria are: intro, elim, dest, name:string,
  3705 simp:term, and any term. Criteria can be preceded by '-' to select
  3706 theorems that do not match. Intro, elim, dest select theorems that
  3707 match the current goal, name:s selects theorems whose fully qualified
  3708 name contain s, and simp:term selects all simplification rules whose
  3709 lhs match term.  Any other term is interpreted as pattern and selects
  3710 all theorems matching the pattern. Available in ProofGeneral under
  3711 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3712 
  3713   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3714 
  3715 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3716 matching the current goal as introduction rule and not having "HOL."
  3717 in their name (i.e. not being defined in theory HOL).
  3718 
  3719 * Command 'thms_containing' has been discontinued in favour of
  3720 'find_theorems'; INCOMPATIBILITY.
  3721 
  3722 * Communication with Proof General is now 8bit clean, which means that
  3723 Unicode text in UTF-8 encoding may be used within theory texts (both
  3724 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3725 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3726 
  3727   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3728   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3729 
  3730 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3731 Classical Reasoner.  Typical big applications run around 2 times
  3732 faster.
  3733 
  3734 
  3735 *** Document preparation ***
  3736 
  3737 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3738 of raw sources.  Only those symbols that do not require additional
  3739 LaTeX packages (depending on comments in isabellesym.sty) are
  3740 displayed properly, everything else is left verbatim.  isatool display
  3741 and isatool print are used as front ends (these are subject to the
  3742 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3743 
  3744 * Command tags control specific markup of certain regions of text,
  3745 notably folding and hiding.  Predefined tags include "theory" (for
  3746 theory begin and end), "proof" for proof commands, and "ML" for
  3747 commands involving ML code; the additional tags "visible" and
  3748 "invisible" are unused by default.  Users may give explicit tag
  3749 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3750 interpretation of tags is determined by the LaTeX job during document
  3751 preparation: see option -V of isatool usedir, or options -n and -t of
  3752 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3753 \isadroptag.
  3754 
  3755 Several document versions may be produced at the same time via isatool
  3756 usedir (the generated index.html will link all of them).  Typical
  3757 specifications include ''-V document=theory,proof,ML'' to present
  3758 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3759 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3760 these parts without any formal replacement text.  The Isabelle site
  3761 default settings produce ''document'' and ''outline'' versions as
  3762 specified above.
  3763 
  3764 * Several new antiquotations:
  3765 
  3766   @{term_type term} prints a term with its type annotated;
  3767 
  3768   @{typeof term} prints the type of a term;
  3769 
  3770   @{const const} is the same as @{term const}, but checks that the
  3771   argument is a known logical constant;
  3772 
  3773   @{term_style style term} and @{thm_style style thm} print a term or
  3774   theorem applying a "style" to it
  3775 
  3776   @{ML text}
  3777 
  3778 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3779 definitions, equations, inequations etc., 'concl' printing only the
  3780 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3781 to print the specified premise.  TermStyle.add_style provides an ML
  3782 interface for introducing further styles.  See also the "LaTeX Sugar"
  3783 document practical applications.  The ML antiquotation prints
  3784 type-checked ML expressions verbatim.
  3785 
  3786 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3787 and 'text' support optional locale specification '(in loc)', which
  3788 specifies the default context for interpreting antiquotations.  For
  3789 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3790 
  3791 * Option 'locale=NAME' of antiquotations specifies an alternative
  3792 context interpreting the subsequent argument.  For example: @{thm
  3793 [locale=lattice] inf_assoc}.
  3794 
  3795 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3796 a proof context.
  3797 
  3798 * Proper output of antiquotations for theory commands involving a
  3799 proof context (such as 'locale' or 'theorem (in loc) ...').
  3800 
  3801 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3802 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3803 
  3804 * isatool usedir: new option -C (default true) controls whether option
  3805 -D should include a copy of the original document directory; -C false
  3806 prevents unwanted effects such as copying of administrative CVS data.
  3807 
  3808 
  3809 *** Pure ***
  3810 
  3811 * Considerably improved version of 'constdefs' command.  Now performs
  3812 automatic type-inference of declared constants; additional support for
  3813 local structure declarations (cf. locales and HOL records), see also
  3814 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3815 sequential dependencies of definitions within a single 'constdefs'
  3816 section; moreover, the declared name needs to be an identifier.  If
  3817 all fails, consider to fall back on 'consts' and 'defs' separately.
  3818 
  3819 * Improved indexed syntax and implicit structures.  First of all,
  3820 indexed syntax provides a notational device for subscripted
  3821 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3822 expressions.  Secondly, in a local context with structure
  3823 declarations, number indexes \<^sub>n or the empty index (default
  3824 number 1) refer to a certain fixed variable implicitly; option
  3825 show_structs controls printing of implicit structures.  Typical
  3826 applications of these concepts involve record types and locales.
  3827 
  3828 * New command 'no_syntax' removes grammar declarations (and
  3829 translations) resulting from the given syntax specification, which is
  3830 interpreted in the same manner as for the 'syntax' command.
  3831 
  3832 * 'Advanced' translation functions (parse_translation etc.) may depend
  3833 on the signature of the theory context being presently used for
  3834 parsing/printing, see also isar-ref manual.
  3835 
  3836 * Improved 'oracle' command provides a type-safe interface to turn an
  3837 ML expression of type theory -> T -> term into a primitive rule of
  3838 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3839 is already included here); see also FOL/ex/IffExample.thy;
  3840 INCOMPATIBILITY.
  3841 
  3842 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3843 before); "cI" is no longer bound, use "c.intro" instead.
  3844 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3845 axclasses vs. locales.
  3846 
  3847 * Improved internal renaming of symbolic identifiers -- attach primes
  3848 instead of base 26 numbers.
  3849 
  3850 * New flag show_question_marks controls printing of leading question
  3851 marks in schematic variable names.
  3852 
  3853 * In schematic variable names, *any* symbol following \<^isub> or
  3854 \<^isup> is now treated as part of the base name.  For example, the
  3855 following works without printing of awkward ".0" indexes:
  3856 
  3857   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3858     by simp
  3859 
  3860 * Inner syntax includes (*(*nested*) comments*).
  3861 
  3862 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3863 annotations as "(00...)".
  3864 
  3865 * Clear separation of logical types and nonterminals, where the latter
  3866 may only occur in 'syntax' specifications or type abbreviations.
  3867 Before that distinction was only partially implemented via type class
  3868 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3869 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3870 exotic syntax specifications may require further adaption
  3871 (e.g. Cube/Cube.thy).
  3872 
  3873 * Removed obsolete type class "logic", use the top sort {} instead.
  3874 Note that non-logical types should be declared as 'nonterminals'
  3875 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3876 specifications.
  3877 
  3878 * Attributes 'induct' and 'cases': type or set names may now be
  3879 locally fixed variables as well.
  3880 
  3881 * Simplifier: can now control the depth to which conditional rewriting
  3882 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3883 Limit.
  3884 
  3885 * Simplifier: simplification procedures may now take the current
  3886 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3887 interface), which is very useful for calling the Simplifier
  3888 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3889 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3890 low-level mk_simproc no longer applies Logic.varify internally, to
  3891 allow for use in a context of fixed variables.
  3892 
  3893 * thin_tac now works even if the assumption being deleted contains !!
  3894 or ==>.  More generally, erule now works even if the major premise of
  3895 the elimination rule contains !! or ==>.
  3896 
  3897 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3898 
  3899 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3900 from Pure, which contains all common declarations already.  Both
  3901 theories are defined via plain Isabelle/Isar .thy files.
  3902 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3903 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3904 use isatool fixcpure to adapt your theory and ML sources.
  3905 
  3906 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3907 selections of theorems in named facts via index ranges.
  3908 
  3909 * 'print_theorems': in theory mode, really print the difference
  3910 wrt. the last state (works for interactive theory development only),
  3911 in proof mode print all local facts (cf. 'print_facts');
  3912 
  3913 * 'hide': option '(open)' hides only base names.
  3914 
  3915 * More efficient treatment of intermediate checkpoints in interactive
  3916 theory development.
  3917 
  3918 * Code generator is now invoked via code_module (incremental code
  3919 generation) and code_library (modular code generation, ML structures
  3920 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3921 must be quoted when used as identifiers.
  3922 
  3923 * New 'value' command for reading, evaluating and printing terms using
  3924 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3925 quoted when used as identifier.
  3926 
  3927 
  3928 *** Locales ***
  3929 
  3930 * New commands for the interpretation of locale expressions in
  3931 theories (1), locales (2) and proof contexts (3).  These generate
  3932 proof obligations from the expression specification.  After the
  3933 obligations have been discharged, theorems of the expression are added
  3934 to the theory, target locale or proof context.  The synopsis of the
  3935 commands is a follows:
  3936 
  3937   (1) interpretation expr inst
  3938   (2) interpretation target < expr
  3939   (3) interpret expr inst
  3940 
  3941 Interpretation in theories and proof contexts require a parameter
  3942 instantiation of terms from the current context.  This is applied to
  3943 specifications and theorems of the interpreted expression.
  3944 Interpretation in locales only permits parameter renaming through the
  3945 locale expression.  Interpretation is smart in that interpretations
  3946 that are active already do not occur in proof obligations, neither are
  3947 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3948 inspect active interpretations of a particular locale.  For details,
  3949 see the Isar Reference manual.  Examples can be found in
  3950 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3951 
  3952 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3953 'interpret' instead.
  3954 
  3955 * New context element 'constrains' for adding type constraints to
  3956 parameters.
  3957 
  3958 * Context expressions: renaming of parameters with syntax
  3959 redeclaration.
  3960 
  3961 * Locale declaration: 'includes' disallowed.
  3962 
  3963 * Proper static binding of attribute syntax -- i.e. types / terms /
  3964 facts mentioned as arguments are always those of the locale definition
  3965 context, independently of the context of later invocations.  Moreover,
  3966 locale operations (renaming and type / term instantiation) are applied
  3967 to attribute arguments as expected.
  3968 
  3969 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3970 actual attributes; rare situations may require Attrib.attribute to
  3971 embed those attributes into Attrib.src that lack concrete syntax.
  3972 Attribute implementations need to cooperate properly with the static
  3973 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3974 Attrib.XXX_thm etc. already do the right thing without further
  3975 intervention.  Only unusual applications -- such as "where" or "of"
  3976 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3977 on the context and the facts involved -- may have to assign parsed
  3978 values to argument tokens explicitly.
  3979 
  3980 * Changed parameter management in theorem generation for long goal
  3981 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3982 theorem statement in rare situations.
  3983 
  3984 * Locale inspection command 'print_locale' omits notes elements.  Use
  3985 'print_locale!' to have them included in the output.
  3986 
  3987 
  3988 *** Provers ***
  3989 
  3990 * Provers/hypsubst.ML: improved version of the subst method, for
  3991 single-step rewriting: it now works in bound variable contexts. New is
  3992 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3993 rewrite a different subterm than the original subst method, which is
  3994 still available as 'simplesubst'.
  3995 
  3996 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3997 and quasi orders.
  3998 
  3999 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4000 reflexive-transitive closure of relations.
  4001 
  4002 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4003 limit (previously hard-coded with a value of 20) user-definable.
  4004 
  4005 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4006 is peformed already.  Object-logics merely need to finish their
  4007 initial simpset configuration as before.  INCOMPATIBILITY.
  4008 
  4009 
  4010 *** HOL ***
  4011 
  4012 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4013 
  4014   syntax (epsilon)
  4015     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4016 
  4017 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4018 and x-symbol; use option '-m epsilon' to get it actually printed.
  4019 Moreover, the mathematically important symbolic identifier \<epsilon>
  4020 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4021 
  4022 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4023 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4024 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4025 support corresponding Isar calculations.
  4026 
  4027 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4028 instead of ":".
  4029 
  4030 * theory SetInterval: changed the syntax for open intervals:
  4031 
  4032   Old       New
  4033   {..n(}    {..<n}
  4034   {)n..}    {n<..}
  4035   {m..n(}   {m..<n}
  4036   {)m..n}   {m<..n}
  4037   {)m..n(}  {m<..<n}
  4038 
  4039 The old syntax is still supported but will disappear in the next
  4040 release.  For conversion use the following Emacs search and replace
  4041 patterns (these are not perfect but work quite well):
  4042 
  4043   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4044   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4045 
  4046 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4047 equalities in commutative rings; method 'algebra' provides a generic
  4048 interface.
  4049 
  4050 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4051 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4052 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4053 be a tuple pattern.
  4054 
  4055 Some new syntax forms are available:
  4056 
  4057   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4058   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4059   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4060   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4061 
  4062 The latter form "\<Sum>x < k. e" used to be based on a separate
  4063 function "Summation", which has been discontinued.
  4064 
  4065 * theory Finite_Set: in structured induction proofs, the insert case
  4066 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4067 (insert F x)'.
  4068 
  4069 * The 'refute' command has been extended to support a much larger
  4070 fragment of HOL, including axiomatic type classes, constdefs and
  4071 typedefs, inductive datatypes and recursion.
  4072 
  4073 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4074 Requires zChaff with proof generation to be installed.  See
  4075 HOL/ex/SAT_Examples.thy for examples.
  4076 
  4077 * Datatype induction via method 'induct' now preserves the name of the
  4078 induction variable. For example, when proving P(xs::'a list) by
  4079 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4080 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4081 in unstructured proof scripts.
  4082 
  4083 * Reworked implementation of records.  Improved scalability for
  4084 records with many fields, avoiding performance problems for type
  4085 inference. Records are no longer composed of nested field types, but
  4086 of nested extension types. Therefore the record type only grows linear
  4087 in the number of extensions and not in the number of fields.  The
  4088 top-level (users) view on records is preserved.  Potential
  4089 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4090 old record representation. The type generated for a record is called
  4091 <record_name>_ext_type.
  4092 
  4093 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4094 proofs triggered by a record definition or a simproc (if
  4095 quick_and_dirty is enabled).  Definitions of large records can take
  4096 quite long.
  4097 
  4098 New simproc record_upd_simproc for simplification of multiple record
  4099 updates enabled by default.  Moreover, trivial updates are also
  4100 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4101 occasionally, since simplification is more powerful by default.
  4102 
  4103 * typedef: proper support for polymorphic sets, which contain extra
  4104 type-variables in the term.
  4105 
  4106 * Simplifier: automatically reasons about transitivity chains
  4107 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4108 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4109 old proofs break occasionally as simplification may now solve more
  4110 goals than previously.
  4111 
  4112 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4113 present.  Works for all partial orders (class "order"), in particular
  4114 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4115 just like y <= x.
  4116 
  4117 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4118 bound variable or a constant then the let is unfolded.  Otherwise
  4119 first a is simplified to b, and then f b is simplified to g. If
  4120 possible we abstract b from g arriving at "let x = b in h x",
  4121 otherwise we unfold the let and arrive at g.  The simproc can be
  4122 enabled/disabled by the reference use_let_simproc.  Potential
  4123 INCOMPATIBILITY since simplification is more powerful by default.
  4124 
  4125 * Classical reasoning: the meson method now accepts theorems as arguments.
  4126 
  4127 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4128 jobs to provide advice on the provability of subgoals.
  4129 
  4130 * Theory OrderedGroup and Ring_and_Field: various additions and
  4131 improvements to faciliate calculations involving equalities and
  4132 inequalities.
  4133 
  4134 The following theorems have been eliminated or modified
  4135 (INCOMPATIBILITY):
  4136 
  4137   abs_eq             now named abs_of_nonneg
  4138   abs_of_ge_0        now named abs_of_nonneg
  4139   abs_minus_eq       now named abs_of_nonpos
  4140   imp_abs_id         now named abs_of_nonneg
  4141   imp_abs_neg_id     now named abs_of_nonpos
  4142   mult_pos           now named mult_pos_pos
  4143   mult_pos_le        now named mult_nonneg_nonneg
  4144   mult_pos_neg_le    now named mult_nonneg_nonpos
  4145   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4146   mult_neg           now named mult_neg_neg
  4147   mult_neg_le        now named mult_nonpos_nonpos
  4148 
  4149 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4150      
  4151      zero_le_square
  4152      not_square_less_zero 
  4153 
  4154   The following lemmas have been deleted from Real/RealPow:
  4155   
  4156      realpow_zero_zero
  4157      realpow_two
  4158      realpow_less
  4159      zero_le_power
  4160      realpow_two_le
  4161      abs_realpow_two
  4162      realpow_two_abs     
  4163 
  4164 * Theory Parity: added rules for simplifying exponents.
  4165 
  4166 * Theory List:
  4167 
  4168 The following theorems have been eliminated or modified
  4169 (INCOMPATIBILITY):
  4170 
  4171   list_all_Nil       now named list_all.simps(1)
  4172   list_all_Cons      now named list_all.simps(2)
  4173   list_all_conv      now named list_all_iff
  4174   set_mem_eq         now named mem_iff
  4175 
  4176 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4177 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4178 
  4179 
  4180 *** HOL-Complex ***
  4181 
  4182 * Theory RealDef: better support for embedding natural numbers and
  4183 integers in the reals.
  4184 
  4185 The following theorems have been eliminated or modified
  4186 (INCOMPATIBILITY):
  4187 
  4188   exp_ge_add_one_self  now requires no hypotheses
  4189   real_of_int_add      reversed direction of equality (use [symmetric])
  4190   real_of_int_minus    reversed direction of equality (use [symmetric])
  4191   real_of_int_diff     reversed direction of equality (use [symmetric])
  4192   real_of_int_mult     reversed direction of equality (use [symmetric])
  4193 
  4194 * Theory RComplete: expanded support for floor and ceiling functions.
  4195 
  4196 * Theory Ln is new, with properties of the natural logarithm
  4197 
  4198 * Hyperreal: There is a new type constructor "star" for making
  4199 nonstandard types.  The old type names are now type synonyms:
  4200 
  4201   hypreal = real star
  4202   hypnat = nat star
  4203   hcomplex = complex star
  4204 
  4205 * Hyperreal: Many groups of similarly-defined constants have been
  4206 replaced by polymorphic versions (INCOMPATIBILITY):
  4207 
  4208   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4209 
  4210   starset      <-- starsetNat, starsetC
  4211   *s*          <-- *sNat*, *sc*
  4212   starset_n    <-- starsetNat_n, starsetC_n
  4213   *sn*         <-- *sNatn*, *scn*
  4214   InternalSets <-- InternalNatSets, InternalCSets
  4215 
  4216   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4217   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4218   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4219   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4220   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4221 
  4222 * Hyperreal: Many type-specific theorems have been removed in favor of
  4223 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4224 
  4225   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4226   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4227   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4228   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4229   right_minus <-- hypreal_add_minus
  4230   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4231   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4232   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4233   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4234   mult_1_right <-- hcomplex_mult_one_right
  4235   mult_zero_left <-- hcomplex_mult_zero_left
  4236   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4237   right_distrib <-- hypnat_add_mult_distrib2
  4238   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4239   right_inverse <-- hypreal_mult_inverse
  4240   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4241   order_refl <-- {hypreal,hypnat}_le_refl
  4242   order_trans <-- {hypreal,hypnat}_le_trans
  4243   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4244   order_less_le <-- {hypreal,hypnat}_less_le
  4245   linorder_linear <-- {hypreal,hypnat}_le_linear
  4246   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4247   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4248   add_nonneg_nonneg <-- hypreal_le_add_order
  4249 
  4250 * Hyperreal: Separate theorems having to do with type-specific
  4251 versions of constants have been merged into theorems that apply to the
  4252 new polymorphic constants (INCOMPATIBILITY):
  4253 
  4254   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4255   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4256   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4257   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4258   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4259   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4260   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4261   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4262   STAR_diff <-- {STAR,STARC}_diff
  4263   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4264     STARC_hcomplex_of_complex}_image_subset
  4265   starset_n_Un <-- starset{Nat,C}_n_Un
  4266   starset_n_Int <-- starset{Nat,C}_n_Int
  4267   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4268   starset_n_diff <-- starset{Nat,C}_n_diff
  4269   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4270   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4271   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4272   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4273   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4274   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4275   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4276   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4277   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4278   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4279   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4280   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4281   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4282   starfun_diff <-- starfun{C,RC,CR}_diff
  4283   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4284   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4285   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4286   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4287   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4288   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4289   starfun_Id <-- starfunC_Id
  4290   starfun_approx <-- starfun{Nat,CR}_approx
  4291   starfun_capprox <-- starfun{C,RC}_capprox
  4292   starfun_abs <-- starfunNat_rabs
  4293   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4294   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4295   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4296   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4297   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4298   starfun_add_approx <-- starfunCR_add_approx
  4299   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4300   starfun_divide <-- starfun{C,CR,RC}_divide
  4301   starfun_n <-- starfun{Nat,C}_n
  4302   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4303   starfun_n_add <-- starfun{Nat,C}_n_add
  4304   starfun_n_add_minus <-- starfunNat_n_add_minus
  4305   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4306   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4307   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4308 
  4309   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4310   star_n_minus <-- {hypreal,hcomplex}_minus
  4311   star_n_diff <-- {hypreal,hcomplex}_diff
  4312   star_n_mult <-- {hypreal,hcomplex}_mult
  4313   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4314   star_n_le <-- {hypreal,hypnat}_le
  4315   star_n_less <-- {hypreal,hypnat}_less
  4316   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4317   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4318   star_n_abs <-- hypreal_hrabs
  4319   star_n_divide <-- hcomplex_divide
  4320 
  4321   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4322   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4323   star_of_diff <-- hypreal_of_real_diff
  4324   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4325   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4326   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4327   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4328   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4329   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4330   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4331   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4332   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4333   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4334   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4335   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4336   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4337   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4338   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4339   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4340   star_of_power <-- hypreal_of_real_power
  4341   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4342 
  4343 * Hyperreal: new method "transfer" that implements the transfer
  4344 principle of nonstandard analysis. With a subgoal that mentions
  4345 nonstandard types like "'a star", the command "apply transfer"
  4346 replaces it with an equivalent one that mentions only standard types.
  4347 To be successful, all free variables must have standard types; non-
  4348 standard variables must have explicit universal quantifiers.
  4349 
  4350 * Hyperreal: A theory of Taylor series.
  4351 
  4352 
  4353 *** HOLCF ***
  4354 
  4355 * Discontinued special version of 'constdefs' (which used to support
  4356 continuous functions) in favor of the general Pure one with full
  4357 type-inference.
  4358 
  4359 * New simplification procedure for solving continuity conditions; it
  4360 is much faster on terms with many nested lambda abstractions (cubic
  4361 instead of exponential time).
  4362 
  4363 * New syntax for domain package: selector names are now optional.
  4364 Parentheses should be omitted unless argument is lazy, for example:
  4365 
  4366   domain 'a stream = cons "'a" (lazy "'a stream")
  4367 
  4368 * New command 'fixrec' for defining recursive functions with pattern
  4369 matching; defining multiple functions with mutual recursion is also
  4370 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4371 sinr, or any data constructor defined by the domain package. The given
  4372 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4373 syntax and examples.
  4374 
  4375 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4376 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4377 but the proof obligation additionally includes an admissibility
  4378 requirement. The packages generate instances of class cpo or pcpo,
  4379 with continuity and strictness theorems for Rep and Abs.
  4380 
  4381 * HOLCF: Many theorems have been renamed according to a more standard naming
  4382 scheme (INCOMPATIBILITY):
  4383 
  4384   foo_inject:  "foo$x = foo$y ==> x = y"
  4385   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4386   foo_less:    "(foo$x << foo$y) = (x << y)"
  4387   foo_strict:  "foo$UU = UU"
  4388   foo_defined: "... ==> foo$x ~= UU"
  4389   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4390 
  4391 
  4392 *** ZF ***
  4393 
  4394 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4395 including the First Isomorphism Theorem (on quotienting by the kernel
  4396 of a homomorphism).
  4397 
  4398 * ZF/Simplifier: install second copy of type solver that actually
  4399 makes use of TC rules declared to Isar proof contexts (or locales);
  4400 the old version is still required for ML proof scripts.
  4401 
  4402 
  4403 *** Cube ***
  4404 
  4405 * Converted to Isar theory format; use locales instead of axiomatic
  4406 theories.
  4407 
  4408 
  4409 *** ML ***
  4410 
  4411 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4412 for ||>, ||>>, |>>,
  4413 
  4414 * Pure/library.ML no longer defines its own option datatype, but uses
  4415 that of the SML basis, which has constructors NONE and SOME instead of
  4416 None and Some, as well as exception Option.Option instead of OPTION.
  4417 The functions the, if_none, is_some, is_none have been adapted
  4418 accordingly, while Option.map replaces apsome.
  4419 
  4420 * Pure/library.ML: the exception LIST has been given up in favour of
  4421 the standard exceptions Empty and Subscript, as well as
  4422 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4423 superceded by the standard hd and tl functions etc.
  4424 
  4425 A number of basic list functions are no longer exported to the ML
  4426 toplevel, as they are variants of predefined functions.  The following
  4427 suggests how one can translate existing code:
  4428 
  4429     rev_append xs ys = List.revAppend (xs, ys)
  4430     nth_elem (i, xs) = List.nth (xs, i)
  4431     last_elem xs = List.last xs
  4432     flat xss = List.concat xss
  4433     seq fs = List.app fs
  4434     partition P xs = List.partition P xs
  4435     mapfilter f xs = List.mapPartial f xs
  4436 
  4437 * Pure/library.ML: several combinators for linear functional
  4438 transformations, notably reverse application and composition:
  4439 
  4440   x |> f                f #> g
  4441   (x, y) |-> f          f #-> g
  4442 
  4443 * Pure/library.ML: introduced/changed precedence of infix operators:
  4444 
  4445   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4446   infix 2 ?;
  4447   infix 3 o oo ooo oooo;
  4448   infix 4 ~~ upto downto;
  4449 
  4450 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4451 infix operators.
  4452 
  4453 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4454 fold_map support linear functional transformations and nesting.  For
  4455 example:
  4456 
  4457   fold f [x1, ..., xN] y =
  4458     y |> f x1 |> ... |> f xN
  4459 
  4460   (fold o fold) f [xs1, ..., xsN] y =
  4461     y |> fold f xs1 |> ... |> fold f xsN
  4462 
  4463   fold f [x1, ..., xN] =
  4464     f x1 #> ... #> f xN
  4465 
  4466   (fold o fold) f [xs1, ..., xsN] =
  4467     fold f xs1 #> ... #> fold f xsN
  4468 
  4469 * Pure/library.ML: the following selectors on type 'a option are
  4470 available:
  4471 
  4472   the:               'a option -> 'a  (*partial*)
  4473   these:             'a option -> 'a  where 'a = 'b list
  4474   the_default: 'a -> 'a option -> 'a
  4475   the_list:          'a option -> 'a list
  4476 
  4477 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4478 basic operations for association lists, following natural argument
  4479 order; moreover the explicit equality predicate passed here avoids
  4480 potentially expensive polymorphic runtime equality checks.
  4481 The old functions may be expressed as follows:
  4482 
  4483   assoc = uncurry (AList.lookup (op =))
  4484   assocs = these oo AList.lookup (op =)
  4485   overwrite = uncurry (AList.update (op =)) o swap
  4486 
  4487 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4488 
  4489   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4490   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4491 
  4492 replacing make_keylist and keyfilter (occassionally used)
  4493 Naive rewrites:
  4494 
  4495   make_keylist = AList.make
  4496   keyfilter = AList.find (op =)
  4497 
  4498 * eq_fst and eq_snd now take explicit equality parameter, thus
  4499   avoiding eqtypes. Naive rewrites:
  4500 
  4501     eq_fst = eq_fst (op =)
  4502     eq_snd = eq_snd (op =)
  4503 
  4504 * Removed deprecated apl and apr (rarely used).
  4505   Naive rewrites:
  4506 
  4507     apl (n, op) =>>= curry op n
  4508     apr (op, m) =>>= fn n => op (n, m)
  4509 
  4510 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4511 provides a reasonably efficient light-weight implementation of sets as
  4512 lists.
  4513 
  4514 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4515 few new operations; existing lookup and update are now curried to
  4516 follow natural argument order (for use with fold etc.);
  4517 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4518 
  4519 * Pure/General: output via the Isabelle channels of
  4520 writeln/warning/error etc. is now passed through Output.output, with a
  4521 hook for arbitrary transformations depending on the print_mode
  4522 (cf. Output.add_mode -- the first active mode that provides a output
  4523 function wins).  Already formatted output may be embedded into further
  4524 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4525 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4526 accommodate easy composition of diagnostic messages etc.  Programmers
  4527 rarely need to care about Output.output or Output.raw at all, with
  4528 some notable exceptions: Output.output is required when bypassing the
  4529 standard channels (writeln etc.), or in token translations to produce
  4530 properly formatted results; Output.raw is required when capturing
  4531 already output material that will eventually be presented to the user
  4532 a second time.  For the default print mode, both Output.output and
  4533 Output.raw have no effect.
  4534 
  4535 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4536 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4537 cumulative results are displayed at the end of a batch session.
  4538 
  4539 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4540 replaced by File.platform_path and File.shell_path (with appropriate
  4541 hooks).  This provides a clean interface for unusual systems where the
  4542 internal and external process view of file names are different.
  4543 
  4544 * Pure: more efficient orders for basic syntactic entities: added
  4545 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4546 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4547 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4548 orders now -- potential INCOMPATIBILITY for code that depends on a
  4549 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4550 Library.sort_strings on result).
  4551 
  4552 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4553 fold_types traverse types/terms from left to right, observing natural
  4554 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4555 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4556 
  4557 * Pure: name spaces have been refined, with significant changes of the
  4558 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4559 to extern(_table).  The plain name entry path is superceded by a
  4560 general 'naming' context, which also includes the 'policy' to produce
  4561 a fully qualified name and external accesses of a fully qualified
  4562 name; NameSpace.extend is superceded by context dependent
  4563 Sign.declare_name.  Several theory and proof context operations modify
  4564 the naming context.  Especially note Theory.restore_naming and
  4565 ProofContext.restore_naming to get back to a sane state; note that
  4566 Theory.add_path is no longer sufficient to recover from
  4567 Theory.absolute_path in particular.
  4568 
  4569 * Pure: new flags short_names (default false) and unique_names
  4570 (default true) for controlling output of qualified names.  If
  4571 short_names is set, names are printed unqualified.  If unique_names is
  4572 reset, the name prefix is reduced to the minimum required to achieve
  4573 the original result when interning again, even if there is an overlap
  4574 with earlier declarations.
  4575 
  4576 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4577 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4578 (useful for printing error messages).  INCOMPATIBILITY.
  4579 
  4580 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4581 Theory.theory are now identified, referring to the universal
  4582 Context.theory (see Pure/context.ML).  Actual signature and theory
  4583 content is managed as theory data.  The old code and interfaces were
  4584 spread over many files and structures; the new arrangement introduces
  4585 considerable INCOMPATIBILITY to gain more clarity:
  4586 
  4587   Context -- theory management operations (name, identity, inclusion,
  4588     parents, ancestors, merge, etc.), plus generic theory data;
  4589 
  4590   Sign -- logical signature and syntax operations (declaring consts,
  4591     types, etc.), plus certify/read for common entities;
  4592 
  4593   Theory -- logical theory operations (stating axioms, definitions,
  4594     oracles), plus a copy of logical signature operations (consts,
  4595     types, etc.); also a few basic management operations (Theory.copy,
  4596     Theory.merge, etc.)
  4597 
  4598 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4599 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4600 for convenience -- they merely return the theory.
  4601 
  4602 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4603 
  4604 * Pure: the Isar proof context type is already defined early in Pure
  4605 as Context.proof (note that ProofContext.context and Proof.context are
  4606 aliases, where the latter is the preferred name).  This enables other
  4607 Isabelle components to refer to that type even before Isar is present.
  4608 
  4609 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4610 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4611 any of these kinds.  For example, Sign.intern typeK is now
  4612 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4613 Theory.hide_types.  Also note that former
  4614 Theory.hide_classes/types/consts are now
  4615 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4616 internalize their arguments!  INCOMPATIBILITY.
  4617 
  4618 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4619 datatype thmref (with constructors Name and NameSelection) instead of
  4620 plain string -- INCOMPATIBILITY;
  4621 
  4622 * Pure: cases produced by proof methods specify options, where NONE
  4623 means to remove case bindings -- INCOMPATIBILITY in
  4624 (RAW_)METHOD_CASES.
  4625 
  4626 * Pure: the following operations retrieve axioms or theorems from a
  4627 theory node or theory hierarchy, respectively:
  4628 
  4629   Theory.axioms_of: theory -> (string * term) list
  4630   Theory.all_axioms_of: theory -> (string * term) list
  4631   PureThy.thms_of: theory -> (string * thm) list
  4632   PureThy.all_thms_of: theory -> (string * thm) list
  4633 
  4634 * Pure: print_tac now outputs the goal through the trace channel.
  4635 
  4636 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4637 Reference Toplevel.debug (default false) controls detailed printing
  4638 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4639 controls execution profiling -- set to 1 for time and 2 for space
  4640 (both increase the runtime).
  4641 
  4642 * Isar session: The initial use of ROOT.ML is now always timed,
  4643 i.e. the log will show the actual process times, in contrast to the
  4644 elapsed wall-clock time that the outer shell wrapper produces.
  4645 
  4646 * Simplifier: improved handling of bound variables (nameless
  4647 representation, avoid allocating new strings).  Simprocs that invoke
  4648 the Simplifier recursively should use Simplifier.inherit_bounds to
  4649 avoid local name clashes.  Failure to do so produces warnings
  4650 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4651 for further details.
  4652 
  4653 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4654 bindings for all theorems stored within a given theory; this may help
  4655 in porting non-Isar theories to Isar ones, while keeping ML proof
  4656 scripts for the time being.
  4657 
  4658 * ML operator HTML.with_charset specifies the charset begin used for
  4659 generated HTML files.  For example:
  4660 
  4661   HTML.with_charset "utf-8" use_thy "Hebrew";
  4662   HTML.with_charset "utf-8" use_thy "Chinese";
  4663 
  4664 
  4665 *** System ***
  4666 
  4667 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4668 isabelle, isatool etc.).
  4669 
  4670 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4671 isatool doc, isatool mkdir, display_drafts etc.).
  4672 
  4673 * isatool usedir: option -f allows specification of the ML file to be
  4674 used by Isabelle; default is ROOT.ML.
  4675 
  4676 * New isatool version outputs the version identifier of the Isabelle
  4677 distribution being used.
  4678 
  4679 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4680 (containing Boolean satisfiability problems) into Isabelle/HOL
  4681 theories.
  4682 
  4683 
  4684 
  4685 New in Isabelle2004 (April 2004)
  4686 --------------------------------
  4687 
  4688 *** General ***
  4689 
  4690 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4691   Replaces linorder.ML.
  4692 
  4693 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4694   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4695   (\<a>...\<z>), are now considered normal letters, and can therefore
  4696   be used anywhere where an ASCII letter (a...zA...Z) has until
  4697   now. COMPATIBILITY: This obviously changes the parsing of some
  4698   terms, especially where a symbol has been used as a binder, say
  4699   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4700   as an identifier.  Fix it by inserting a space around former
  4701   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4702   existing theory and ML files.
  4703 
  4704 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4705 
  4706 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4707   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4708   a normal (but invisible) letter. For multiple letter subscripts repeat
  4709   \<^isub> like this: x\<^isub>1\<^isub>2.
  4710 
  4711 * Pure: There are now sub-/superscripts that can span more than one
  4712   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4713   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4714   superscript. The new control characters are not identifier parts.
  4715 
  4716 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4717   content of "..." to the latex file instead of \isacntrl... . The "..."
  4718   may consist of any printable characters excluding the end bracket >.
  4719 
  4720 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4721   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4722   declare constants "final", which prevents their being given a definition
  4723   later.  It is useful for constants whose behaviour is fixed axiomatically
  4724   rather than definitionally, such as the meta-logic connectives.
  4725 
  4726 * Pure: 'instance' now handles general arities with general sorts
  4727   (i.e. intersections of classes),
  4728 
  4729 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4730   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4731   It can be changed to alter the colors/layout of generated pages.
  4732 
  4733 
  4734 *** Isar ***
  4735 
  4736 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4737   cut_tac, subgoal_tac and thin_tac:
  4738   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4739     locales are no longer forced to write Isar proof scripts.
  4740     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4741     emulations.
  4742   - INCOMPATIBILITY: names of variables to be instantiated may no
  4743     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4744     This is consistent with the instantiation attribute "where".
  4745 
  4746 * Attributes "where" and "of":
  4747   - Now take type variables of instantiated theorem into account when reading
  4748     the instantiation string.  This fixes a bug that caused instantiated
  4749     theorems to have too special types in some circumstances.
  4750   - "where" permits explicit instantiations of type variables.
  4751 
  4752 * Calculation commands "moreover" and "also" no longer interfere with
  4753   current facts ("this"), admitting arbitrary combinations with "then"
  4754   and derived forms.
  4755 
  4756 * Locales:
  4757   - Goal statements involving the context element "includes" no longer
  4758     generate theorems with internal delta predicates (those ending on
  4759     "_axioms") in the premise.
  4760     Resolve particular premise with <locale>.intro to obtain old form.
  4761   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4762     specification and "includes" elements in goal statement.
  4763   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4764     [intro?] and [elim?] (respectively) by default.
  4765   - Experimental command for instantiation of locales in proof contexts:
  4766         instantiate <label>[<attrs>]: <loc>
  4767     Instantiates locale <loc> and adds all its theorems to the current context
  4768     taking into account their attributes.  Label and attrs are optional
  4769     modifiers, like in theorem declarations.  If present, names of
  4770     instantiated theorems are qualified with <label>, and the attributes
  4771     <attrs> are applied after any attributes these theorems might have already.
  4772       If the locale has assumptions, a chained fact of the form
  4773     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4774     are derived.  The command does not support old-style locales declared
  4775     with "locale (open)".
  4776       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4777 
  4778 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4779   (Isar) contexts.
  4780 
  4781 
  4782 *** HOL ***
  4783 
  4784 * Proof import: new image HOL4 contains the imported library from
  4785   the HOL4 system with about 2500 theorems. It is imported by
  4786   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4787   can be used like any other Isabelle image.  See
  4788   HOL/Import/HOL/README for more information.
  4789 
  4790 * Simplifier:
  4791   - Much improved handling of linear and partial orders.
  4792     Reasoners for linear and partial orders are set up for type classes
  4793     "linorder" and "order" respectively, and are added to the default simpset
  4794     as solvers.  This means that the simplifier can build transitivity chains
  4795     to solve goals from the assumptions.
  4796   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4797     of blast or auto after simplification become unnecessary because the goal
  4798     is solved by simplification already.
  4799 
  4800 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4801     all proved in axiomatic type classes for semirings, rings and fields.
  4802 
  4803 * Numerics:
  4804   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4805     now formalized using the Ring_and_Field theory mentioned above.
  4806   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4807     than before, because now they are set up once in a generic manner.
  4808   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4809     Look for the general versions in Ring_and_Field (and Power if they concern
  4810     exponentiation).
  4811 
  4812 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4813 
  4814 * Records:
  4815   - Record types are now by default printed with their type abbreviation
  4816     instead of the list of all field types. This can be configured via
  4817     the reference "print_record_type_abbr".
  4818   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4819     (not enabled by default).
  4820   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4821     EX x. x = sel r to True (not enabled by default).
  4822   - Tactic "record_split_simp_tac" to split and simplify records added.
  4823 
  4824 * 'specification' command added, allowing for definition by
  4825   specification.  There is also an 'ax_specification' command that
  4826   introduces the new constants axiomatically.
  4827 
  4828 * arith(_tac) is now able to generate counterexamples for reals as well.
  4829 
  4830 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4831 
  4832 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4833   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4834 
  4835 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4836   matrix theory to linear programming.
  4837 
  4838 * Unions and Intersections:
  4839   The latex output syntax of UN and INT has been changed
  4840   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4841   i.e. the index formulae has become a subscript.
  4842   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4843 
  4844 * Unions and Intersections over Intervals:
  4845   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4846   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4847   like in normal math, and corresponding versions for < and for intersection.
  4848 
  4849 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4850   lexicographic dictonary ordering has been added as "lexord".
  4851 
  4852 * ML: the legacy theory structures Int and List have been removed. They had
  4853   conflicted with ML Basis Library structures having the same names.
  4854 
  4855 * 'refute' command added to search for (finite) countermodels.  Only works
  4856   for a fragment of HOL.  The installation of an external SAT solver is
  4857   highly recommended.  See "HOL/Refute.thy" for details.
  4858 
  4859 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4860   formulae under an assignment of free variables to random values.
  4861   In contrast to 'refute', it can deal with inductive datatypes,
  4862   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4863   for examples.
  4864 
  4865 
  4866 *** HOLCF ***
  4867 
  4868 * Streams now come with concatenation and are part of the HOLCF image
  4869 
  4870 
  4871 
  4872 New in Isabelle2003 (May 2003)
  4873 ------------------------------
  4874 
  4875 *** General ***
  4876 
  4877 * Provers/simplifier:
  4878 
  4879   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4880     Assumptions are now subject to complete mutual simplification,
  4881     not just from left to right. The simplifier now preserves
  4882     the order of assumptions.
  4883 
  4884     Potential INCOMPATIBILITY:
  4885 
  4886     -- simp sometimes diverges where the old version did
  4887        not, e.g. invoking simp on the goal
  4888 
  4889         [| P (f x); y = x; f x = f y |] ==> Q
  4890 
  4891        now gives rise to the infinite reduction sequence
  4892 
  4893         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4894 
  4895        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4896        kind of problem.
  4897 
  4898     -- Tactics combining classical reasoner and simplification (such as auto)
  4899        are also affected by this change, because many of them rely on
  4900        simp. They may sometimes diverge as well or yield a different numbers
  4901        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4902        in case of problems. Sometimes subsequent calls to the classical
  4903        reasoner will fail because a preceeding call to the simplifier too
  4904        eagerly simplified the goal, e.g. deleted redundant premises.
  4905 
  4906   - The simplifier trace now shows the names of the applied rewrite rules
  4907 
  4908   - You can limit the number of recursive invocations of the simplifier
  4909     during conditional rewriting (where the simplifie tries to solve the
  4910     conditions before applying the rewrite rule):
  4911     ML "simp_depth_limit := n"
  4912     where n is an integer. Thus you can force termination where previously
  4913     the simplifier would diverge.
  4914 
  4915   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4916 
  4917   - No longer aborts on failed congruence proof.  Instead, the
  4918     congruence is ignored.
  4919 
  4920 * Pure: New generic framework for extracting programs from constructive
  4921   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4922   as HOL/Extraction for some case studies.
  4923 
  4924 * Pure: The main goal of the proof state is no longer shown by default, only
  4925 the subgoals. This behaviour is controlled by a new flag.
  4926    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4927 (ML: Proof.show_main_goal).
  4928 
  4929 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4930 rules whose conclusion matches subgoal 1:
  4931       PG menu: Isabelle/Isar -> Show me -> matching rules
  4932 The rules are ordered by how closely they match the subgoal.
  4933 In particular, rules that solve a subgoal outright are displayed first
  4934 (or rather last, the way they are printed).
  4935 (ML: ProofGeneral.print_intros())
  4936 
  4937 * Pure: New flag trace_unify_fail causes unification to print
  4938 diagnostic information (PG: in trace buffer) when it fails. This is
  4939 useful for figuring out why single step proofs like rule, erule or
  4940 assumption failed.
  4941 
  4942 * Pure: Locale specifications now produce predicate definitions
  4943 according to the body of text (covering assumptions modulo local
  4944 definitions); predicate "loc_axioms" covers newly introduced text,
  4945 while "loc" is cumulative wrt. all included locale expressions; the
  4946 latter view is presented only on export into the global theory
  4947 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4948 on the old view without predicates;
  4949 
  4950 * Pure: predefined locales "var" and "struct" are useful for sharing
  4951 parameters (as in CASL, for example); just specify something like
  4952 ``var x + var y + struct M'' as import;
  4953 
  4954 * Pure: improved thms_containing: proper indexing of facts instead of
  4955 raw theorems; check validity of results wrt. current name space;
  4956 include local facts of proof configuration (also covers active
  4957 locales), cover fixed variables in index; may use "_" in term
  4958 specification; an optional limit for the number of printed facts may
  4959 be given (the default is 40);
  4960 
  4961 * Pure: disallow duplicate fact bindings within new-style theory files
  4962 (batch-mode only);
  4963 
  4964 * Provers: improved induct method: assumptions introduced by case
  4965 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4966 the goal statement); "foo" still refers to all facts collectively;
  4967 
  4968 * Provers: the function blast.overloaded has been removed: all constants
  4969 are regarded as potentially overloaded, which improves robustness in exchange
  4970 for slight decrease in efficiency;
  4971 
  4972 * Provers/linorder: New generic prover for transitivity reasoning over
  4973 linear orders.  Note: this prover is not efficient!
  4974 
  4975 * Isar: preview of problems to finish 'show' now produce an error
  4976 rather than just a warning (in interactive mode);
  4977 
  4978 
  4979 *** HOL ***
  4980 
  4981 * arith(_tac)
  4982 
  4983  - Produces a counter example if it cannot prove a goal.
  4984    Note that the counter example may be spurious if the goal is not a formula
  4985    of quantifier-free linear arithmetic.
  4986    In ProofGeneral the counter example appears in the trace buffer.
  4987 
  4988  - Knows about div k and mod k where k is a numeral of type nat or int.
  4989 
  4990  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4991    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4992    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4993 
  4994 * simp's arithmetic capabilities have been enhanced a bit: it now
  4995 takes ~= in premises into account (by performing a case split);
  4996 
  4997 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4998 are distributed over a sum of terms;
  4999 
  5000 * New tactic "trans_tac" and method "trans" instantiate
  5001 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5002 "<=", "<" and "=").
  5003 
  5004 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5005 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5006 
  5007 * 'typedef' command has new option "open" to suppress the set
  5008 definition;
  5009 
  5010 * functions Min and Max on finite sets have been introduced (theory
  5011 Finite_Set);
  5012 
  5013 * attribute [symmetric] now works for relations as well; it turns
  5014 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5015 
  5016 * induct over a !!-quantified statement (say !!x1..xn):
  5017   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5018 
  5019 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5020 %x. None. Warning: empty_def now refers to the previously hidden definition
  5021 of the empty set.
  5022 
  5023 * Algebra: formalization of classical algebra.  Intended as base for
  5024 any algebraic development in Isabelle.  Currently covers group theory
  5025 (up to Sylow's theorem) and ring theory (Universal Property of
  5026 Univariate Polynomials).  Contributions welcome;
  5027 
  5028 * GroupTheory: deleted, since its material has been moved to Algebra;
  5029 
  5030 * Complex: new directory of the complex numbers with numeric constants,
  5031 nonstandard complex numbers, and some complex analysis, standard and
  5032 nonstandard (Jacques Fleuriot);
  5033 
  5034 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5035 
  5036 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5037 Fleuriot);
  5038 
  5039 * Real/HahnBanach: updated and adapted to locales;
  5040 
  5041 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5042 Gray and Kramer);
  5043 
  5044 * UNITY: added the Meier-Sanders theory of progress sets;
  5045 
  5046 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5047 as abstract algorithms, instantiated to the JVM;
  5048 
  5049 * Bali: Java source language formalization. Type system, operational
  5050 semantics, axiomatic semantics. Supported language features:
  5051 classes, interfaces, objects,virtual methods, static methods,
  5052 static/instance fields, arrays, access modifiers, definite
  5053 assignment, exceptions.
  5054 
  5055 
  5056 *** ZF ***
  5057 
  5058 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5059 universe, etc.);
  5060 
  5061 * Main ZF: virtually all theories converted to new-style format;
  5062 
  5063 
  5064 *** ML ***
  5065 
  5066 * Pure: Tactic.prove provides sane interface for internal proofs;
  5067 omits the infamous "standard" operation, so this is more appropriate
  5068 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5069 
  5070 * Pure: improved error reporting of simprocs;
  5071 
  5072 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5073 up simprocs;
  5074 
  5075 
  5076 *** Document preparation ***
  5077 
  5078 * uses \par instead of \\ for line breaks in theory text. This may
  5079 shift some page breaks in large documents. To get the old behaviour
  5080 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5081 
  5082 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5083 other packages
  5084 
  5085 * \<euro> now needs package babel/greek instead of marvosym (which
  5086 broke \Rightarrow)
  5087 
  5088 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5089 textcomp package)
  5090 
  5091 
  5092 
  5093 New in Isabelle2002 (March 2002)
  5094 --------------------------------
  5095 
  5096 *** Document preparation ***
  5097 
  5098 * greatly simplified document preparation setup, including more
  5099 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5100 instructive isatool mkdir; users should basically be able to get
  5101 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5102 users may run a separate document processing stage manually like this:
  5103 "isatool usedir -D output HOL Test && isatool document Test/output";
  5104 
  5105 * theory dependency graph may now be incorporated into documents;
  5106 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5107 with \includegraphics of LaTeX;
  5108 
  5109 * proper spacing of consecutive markup elements, especially text
  5110 blocks after section headings;
  5111 
  5112 * support bold style (for single symbols only), input syntax is like
  5113 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5114 
  5115 * \<bullet> is now output as bold \cdot by default, which looks much
  5116 better in printed text;
  5117 
  5118 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5119 note that these symbols are currently unavailable in Proof General /
  5120 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5121 
  5122 * isatool latex no longer depends on changed TEXINPUTS, instead
  5123 isatool document copies the Isabelle style files to the target
  5124 location;
  5125 
  5126 
  5127 *** Isar ***
  5128 
  5129 * Pure/Provers: improved proof by cases and induction;
  5130   - 'case' command admits impromptu naming of parameters (such as
  5131     "case (Suc n)");
  5132   - 'induct' method divinates rule instantiation from the inductive
  5133     claim; no longer requires excessive ?P bindings for proper
  5134     instantiation of cases;
  5135   - 'induct' method properly enumerates all possibilities of set/type
  5136     rules; as a consequence facts may be also passed through *type*
  5137     rules without further ado;
  5138   - 'induct' method now derives symbolic cases from the *rulified*
  5139     rule (before it used to rulify cases stemming from the internal
  5140     atomized version); this means that the context of a non-atomic
  5141     statement becomes is included in the hypothesis, avoiding the
  5142     slightly cumbersome show "PROP ?case" form;
  5143   - 'induct' may now use elim-style induction rules without chaining
  5144     facts, using ``missing'' premises from the goal state; this allows
  5145     rules stemming from inductive sets to be applied in unstructured
  5146     scripts, while still benefitting from proper handling of non-atomic
  5147     statements; NB: major inductive premises need to be put first, all
  5148     the rest of the goal is passed through the induction;
  5149   - 'induct' proper support for mutual induction involving non-atomic
  5150     rule statements (uses the new concept of simultaneous goals, see
  5151     below);
  5152   - append all possible rule selections, but only use the first
  5153     success (no backtracking);
  5154   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5155   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5156   - added 'print_induct_rules' (covered by help item in recent Proof
  5157     General versions);
  5158   - moved induct/cases attributes to Pure, methods to Provers;
  5159   - generic method setup instantiated for FOL and HOL;
  5160 
  5161 * Pure: support multiple simultaneous goal statements, for example
  5162 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5163 meta-level mechanism, this acts as if several individual goals had
  5164 been stated separately; in particular common proof methods need to be
  5165 repeated in order to cover all claims; note that a single elimination
  5166 step is *not* sufficient to establish the two conjunctions, so this
  5167 fails:
  5168 
  5169   assume "A & B" then have A and B ..   (*".." fails*)
  5170 
  5171 better use "obtain" in situations as above; alternative refer to
  5172 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5173 
  5174 * Pure: proper integration with ``locales''; unlike the original
  5175 version by Florian Kammller, Isar locales package high-level proof
  5176 contexts rather than raw logical ones (e.g. we admit to include
  5177 attributes everywhere); operations on locales include merge and
  5178 rename; support for implicit arguments (``structures''); simultaneous
  5179 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5180 some examples;
  5181 
  5182 * Pure: the following commands have been ``localized'', supporting a
  5183 target locale specification "(in name)": 'lemma', 'theorem',
  5184 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5185 stored both within the locale and at the theory level (exported and
  5186 qualified by the locale name);
  5187 
  5188 * Pure: theory goals may now be specified in ``long'' form, with
  5189 ad-hoc contexts consisting of arbitrary locale elements. for example
  5190 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5191 definitions may be given, too); the result is a meta-level rule with
  5192 the context elements being discharged in the obvious way;
  5193 
  5194 * Pure: new proof command 'using' allows to augment currently used
  5195 facts after a goal statement ('using' is syntactically analogous to
  5196 'apply', but acts on the goal's facts only); this allows chained facts
  5197 to be separated into parts given before and after a claim, as in
  5198 ``from a and b have C using d and e <proof>'';
  5199 
  5200 * Pure: renamed "antecedent" case to "rule_context";
  5201 
  5202 * Pure: new 'judgment' command records explicit information about the
  5203 object-logic embedding (used by several tools internally); no longer
  5204 use hard-wired "Trueprop";
  5205 
  5206 * Pure: added 'corollary' command;
  5207 
  5208 * Pure: fixed 'token_translation' command;
  5209 
  5210 * Pure: removed obsolete 'exported' attribute;
  5211 
  5212 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5213 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5214 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5215 
  5216 * Pure: method 'atomize' presents local goal premises as object-level
  5217 statements (atomic meta-level propositions); setup controlled via
  5218 rewrite rules declarations of 'atomize' attribute; example
  5219 application: 'induct' method with proper rule statements in improper
  5220 proof *scripts*;
  5221 
  5222 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5223 now consider the syntactic context of assumptions, giving a better
  5224 chance to get type-inference of the arguments right (this is
  5225 especially important for locales);
  5226 
  5227 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5228 mode;
  5229 
  5230 * Pure/obtain: the formal conclusion "thesis", being marked as
  5231 ``internal'', may no longer be reference directly in the text;
  5232 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5233 situations;
  5234 
  5235 * Pure: generic 'sym' attribute which declares a rule both as pure
  5236 'elim?' and for the 'symmetric' operation;
  5237 
  5238 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5239 text; the fixed correlation with particular command syntax has been
  5240 discontinued;
  5241 
  5242 * Pure: new method 'rules' is particularly well-suited for proof
  5243 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5244 but often produces more compact proof terms with less detours;
  5245 
  5246 * Pure/Provers/classical: simplified integration with pure rule
  5247 attributes and methods; the classical "intro?/elim?/dest?"
  5248 declarations coincide with the pure ones; the "rule" method no longer
  5249 includes classically swapped intros; "intro" and "elim" methods no
  5250 longer pick rules from the context; also got rid of ML declarations
  5251 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5252 INCOMPATIBILITY;
  5253 
  5254 * Provers/classical: attribute 'swapped' produces classical inversions
  5255 of introduction rules;
  5256 
  5257 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5258 rules instead of full simplifier context; 'iff' attribute handles
  5259 conditional rules;
  5260 
  5261 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5262 
  5263 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5264 "(permissive)" option to recover old behavior;
  5265 
  5266 * HOL: 'inductive' no longer features separate (collective) attributes
  5267 for 'intros' (was found too confusing);
  5268 
  5269 * HOL: properly declared induction rules less_induct and
  5270 wf_induct_rule;
  5271 
  5272 
  5273 *** HOL ***
  5274 
  5275 * HOL: moved over to sane numeral syntax; the new policy is as
  5276 follows:
  5277 
  5278   - 0 and 1 are polymorphic constants, which are defined on any
  5279   numeric type (nat, int, real etc.);
  5280 
  5281   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5282   binary representation internally;
  5283 
  5284   - type nat has special constructor Suc, and generally prefers Suc 0
  5285   over 1::nat and Suc (Suc 0) over 2::nat;
  5286 
  5287 This change may cause significant problems of INCOMPATIBILITY; here
  5288 are some hints on converting existing sources:
  5289 
  5290   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5291   entities, so expressions involving "-" (unary or binary minus) need
  5292   to be spaced properly;
  5293 
  5294   - existing occurrences of "1" may need to be constraint "1::nat" or
  5295   even replaced by Suc 0; similar for old "2";
  5296 
  5297   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5298 
  5299   - remove all special provisions on numerals in proofs;
  5300 
  5301 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5302 representation (depends on bin_arith_simps in the default context);
  5303 
  5304 * HOL: symbolic syntax for x^2 (numeral 2);
  5305 
  5306 * HOL: the class of all HOL types is now called "type" rather than
  5307 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5308 in axclass/classes, instance/arities, and (usually rare) occurrences
  5309 in typings (of consts etc.); internally the class is called
  5310 "HOL.type", ML programs should refer to HOLogic.typeS;
  5311 
  5312 * HOL/record package improvements:
  5313   - new derived operations "fields" to build a partial record section,
  5314     "extend" to promote a fixed record to a record scheme, and
  5315     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5316     declared as simp by default;
  5317   - shared operations ("more", "fields", etc.) now need to be always
  5318     qualified) --- potential INCOMPATIBILITY;
  5319   - removed "make_scheme" operations (use "make" with "extend") --
  5320     INCOMPATIBILITY;
  5321   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5322   - provides cases/induct rules for use with corresponding Isar
  5323     methods (for concrete records, record schemes, concrete more
  5324     parts, and schematic more parts -- in that order);
  5325   - internal definitions directly based on a light-weight abstract
  5326     theory of product types over typedef rather than datatype;
  5327 
  5328 * HOL: generic code generator for generating executable ML code from
  5329 specifications; specific support for HOL constructs such as inductive
  5330 datatypes and sets, as well as recursive functions; can be invoked
  5331 via 'generate_code' theory section;
  5332 
  5333 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5334 
  5335 * HOL: consolidated and renamed several theories.  In particular:
  5336         Ord.thy has been absorbed into HOL.thy
  5337         String.thy has been absorbed into List.thy
  5338 
  5339 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5340 (beware of argument permutation!);
  5341 
  5342 * HOL: linorder_less_split superseded by linorder_cases;
  5343 
  5344 * HOL/List: "nodups" renamed to "distinct";
  5345 
  5346 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5347 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5348   - Ex_def has changed, now need to use some_eq_ex
  5349 
  5350 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5351 in this (rare) case use:
  5352 
  5353   delSWrapper "split_all_tac"
  5354   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5355 
  5356 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5357 MAY FAIL;
  5358 
  5359 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5360 Isabelle's type classes, ^ on functions and relations has too general
  5361 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5362 necessary to attach explicit type constraints;
  5363 
  5364 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5365 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5366 renamed accordingly (eg "compI" -> "rel_compI").
  5367 
  5368 * HOL: syntax translations now work properly with numerals and records
  5369 expressions;
  5370 
  5371 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5372 of "lam" -- INCOMPATIBILITY;
  5373 
  5374 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5375 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5376 renamed "Product_Type.unit";
  5377 
  5378 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5379 
  5380 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5381 the "cases" method);
  5382 
  5383 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5384 Florian Kammller);
  5385 
  5386 * HOL/IMP: updated and converted to new-style theory format; several
  5387 parts turned into readable document, with proper Isar proof texts and
  5388 some explanations (by Gerwin Klein);
  5389 
  5390 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5391 
  5392 * HOL-Hyperreal is now a logic image;
  5393 
  5394 
  5395 *** HOLCF ***
  5396 
  5397 * Isar: consts/constdefs supports mixfix syntax for continuous
  5398 operations;
  5399 
  5400 * Isar: domain package adapted to new-style theory format, e.g. see
  5401 HOLCF/ex/Dnat.thy;
  5402 
  5403 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5404 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5405 lift.induct_tac, always use UU instead of Undef;
  5406 
  5407 * HOLCF/IMP: updated and converted to new-style theory;
  5408 
  5409 
  5410 *** ZF ***
  5411 
  5412 * Isar: proper integration of logic-specific tools and packages,
  5413 including theory commands '(co)inductive', '(co)datatype',
  5414 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5415 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5416 
  5417 * theory Main no longer includes AC; for the Axiom of Choice, base
  5418 your theory on Main_ZFC;
  5419 
  5420 * the integer library now covers quotients and remainders, with many
  5421 laws relating division to addition, multiplication, etc.;
  5422 
  5423 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5424 typeless version of the formalism;
  5425 
  5426 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5427 format;
  5428 
  5429 * ZF/Induct: new directory for examples of inductive definitions,
  5430 including theory Multiset for multiset orderings; converted to
  5431 new-style theory format;
  5432 
  5433 * ZF: many new theorems about lists, ordinals, etc.;
  5434 
  5435 
  5436 *** General ***
  5437 
  5438 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5439 variable proof controls level of detail: 0 = no proofs (only oracle
  5440 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5441 also ref manual for further ML interfaces;
  5442 
  5443 * Pure/axclass: removed obsolete ML interface
  5444 goal_subclass/goal_arity;
  5445 
  5446 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5447 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5448 separate tokens, so expressions involving minus need to be spaced
  5449 properly;
  5450 
  5451 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5452 rather than "infixl" or "infixr";
  5453 
  5454 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5455 sort constraint specifications in type inference; e.g. "x::_::foo"
  5456 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5457 type variable);
  5458 
  5459 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5460 control output of nested => (types); the default behavior is
  5461 "type_brackets";
  5462 
  5463 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5464 tokens into AST constants;
  5465 
  5466 * Pure/syntax: prefer later declarations of translations and print
  5467 translation functions; potential INCOMPATIBILITY: need to reverse
  5468 multiple declarations for same syntax element constant;
  5469 
  5470 * Pure/show_hyps reset by default (in accordance to existing Isar
  5471 practice);
  5472 
  5473 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5474 addSafter;
  5475 
  5476 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5477 as well;
  5478 
  5479 * system: tested support for MacOS X; should be able to get Isabelle +
  5480 Proof General to work in a plain Terminal after installing Poly/ML
  5481 (e.g. from the Isabelle distribution area) and GNU bash alone
  5482 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5483 support requires further installations, e.g. from
  5484 http://fink.sourceforge.net/);
  5485 
  5486 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5487 
  5488 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5489 of 40 MB), cf. ML_OPTIONS;
  5490 
  5491 * system: Proof General keywords specification is now part of the
  5492 Isabelle distribution (see etc/isar-keywords.el);
  5493 
  5494 * system: support for persistent Proof General sessions (refrain from
  5495 outdating all loaded theories on startup); user may create writable
  5496 logic images like this: ``isabelle -q HOL Test'';
  5497 
  5498 * system: smart selection of Isabelle process versus Isabelle
  5499 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5500 run both "isabelle" and "Isabelle" even if file names are badly
  5501 damaged (executable inspects the case of the first letter of its own
  5502 name); added separate "isabelle-process" and "isabelle-interface";
  5503 
  5504 * system: refrain from any attempt at filtering input streams; no
  5505 longer support ``8bit'' encoding of old isabelle font, instead proper
  5506 iso-latin characters may now be used; the related isatools
  5507 "symbolinput" and "nonascii" have disappeared as well;
  5508 
  5509 * system: removed old "xterm" interface (the print modes "xterm" and
  5510 "xterm_color" are still available for direct use in a suitable
  5511 terminal);
  5512 
  5513 
  5514 
  5515 New in Isabelle99-2 (February 2001)
  5516 -----------------------------------
  5517 
  5518 *** Overview of INCOMPATIBILITIES ***
  5519 
  5520 * HOL: please note that theories in the Library and elsewhere often use the
  5521 new-style (Isar) format; to refer to their theorems in an ML script you must
  5522 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5523 
  5524 * HOL: inductive package no longer splits induction rule aggressively,
  5525 but only as far as specified by the introductions given; the old
  5526 format may be recovered via ML function complete_split_rule or attribute
  5527 'split_rule (complete)';
  5528 
  5529 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5530 gfp_Tarski to gfp_unfold;
  5531 
  5532 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5533 
  5534 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5535 relation); infix "^^" has been renamed "``"; infix "``" has been
  5536 renamed "`"; "univalent" has been renamed "single_valued";
  5537 
  5538 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5539 operation;
  5540 
  5541 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5542 
  5543 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5544 
  5545 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5546 consequence, it is no longer monotonic wrt. the local goal context
  5547 (which is now passed through the inductive cases);
  5548 
  5549 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5550 \<gg> to \<ggreater>;
  5551 
  5552 
  5553 *** Document preparation ***
  5554 
  5555 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5556 available: are "it" for near math-mode best-style output, "sl" for
  5557 slanted text style, and "tt" for plain type-writer; if no
  5558 \isabellestyle command is given, output is according to slanted
  5559 type-writer);
  5560 
  5561 * support sub/super scripts (for single symbols only), input syntax is
  5562 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5563 
  5564 * some more standard symbols; see Appendix A of the system manual for
  5565 the complete list of symbols defined in isabellesym.sty;
  5566 
  5567 * improved isabelle style files; more abstract symbol implementation
  5568 (should now use \isamath{...} and \isatext{...} in custom symbol
  5569 definitions);
  5570 
  5571 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5572 state; Note that presentation of goal states does not conform to
  5573 actual human-readable proof documents.  Please do not include goal
  5574 states into document output unless you really know what you are doing!
  5575 
  5576 * proper indentation of antiquoted output with proportional LaTeX
  5577 fonts;
  5578 
  5579 * no_document ML operator temporarily disables LaTeX document
  5580 generation;
  5581 
  5582 * isatool unsymbolize tunes sources for plain ASCII communication;
  5583 
  5584 
  5585 *** Isar ***
  5586 
  5587 * Pure: Isar now suffers initial goal statements to contain unbound
  5588 schematic variables (this does not conform to actual readable proof
  5589 documents, due to unpredictable outcome and non-compositional proof
  5590 checking); users who know what they are doing may use schematic goals
  5591 for Prolog-style synthesis of proven results;
  5592 
  5593 * Pure: assumption method (an implicit finishing) now handles actual
  5594 rules as well;
  5595 
  5596 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5597 initial goal, declare "that" only as Pure intro (only for single
  5598 steps); the "that" rule assumption may now be involved in implicit
  5599 finishing, thus ".." becomes a feasible for trivial obtains;
  5600 
  5601 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5602 instance proofs may be performed by "..";
  5603 
  5604 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5605 statements as well;
  5606 
  5607 * Pure: more robust selection of calculational rules;
  5608 
  5609 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5610 rule (as well as the assumption rule);
  5611 
  5612 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5613 lemmas, using the graph browser tool;
  5614 
  5615 * Pure: predict failure of "show" in interactive mode;
  5616 
  5617 * Pure: 'thms_containing' now takes actual terms as arguments;
  5618 
  5619 * HOL: improved method 'induct' --- now handles non-atomic goals
  5620 (potential INCOMPATIBILITY); tuned error handling;
  5621 
  5622 * HOL: cases and induct rules now provide explicit hints about the
  5623 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5624 any remaining facts are inserted into the goal verbatim;
  5625 
  5626 * HOL: local contexts (aka cases) may now contain term bindings as
  5627 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5628 the result to be shown in each case;
  5629 
  5630 * HOL: added 'recdef_tc' command;
  5631 
  5632 * isatool convert assists in eliminating legacy ML scripts;
  5633 
  5634 
  5635 *** HOL ***
  5636 
  5637 * HOL/Library: a collection of generic theories to be used together
  5638 with main HOL; the theory loader path already includes this directory
  5639 by default; the following existing theories have been moved here:
  5640 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5641 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5642 
  5643 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5644 modelling and verification task performed in Isabelle/HOL +
  5645 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5646 
  5647 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5648 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5649 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5650 'domain', this makes the theory consistent with mathematical
  5651 literature;
  5652 
  5653 * HOL basics: added overloaded operations "inverse" and "divide"
  5654 (infix "/"), syntax for generic "abs" operation, generic summation
  5655 operator \<Sum>;
  5656 
  5657 * HOL/typedef: simplified package, provide more useful rules (see also
  5658 HOL/subset.thy);
  5659 
  5660 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5661 now expressed as a proper nested rule (old-style tactic scripts may
  5662 require atomize_strip_tac to cope with non-atomic premises);
  5663 
  5664 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5665 to "split_conv" (old name still available for compatibility);
  5666 
  5667 * HOL: improved concrete syntax for strings (e.g. allows translation
  5668 rules with string literals);
  5669 
  5670 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5671  and Fleuriot's mechanization of analysis, including the transcendental
  5672  functions for the reals;
  5673 
  5674 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5675 
  5676 
  5677 *** CTT ***
  5678 
  5679 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5680 "lam" is displayed as TWO lambda-symbols
  5681 
  5682 * CTT: theory Main now available, containing everything (that is, Bool
  5683 and Arith);
  5684 
  5685 
  5686 *** General ***
  5687 
  5688 * Pure: the Simplifier has been implemented properly as a derived rule
  5689 outside of the actual kernel (at last!); the overall performance
  5690 penalty in practical applications is about 50%, while reliability of
  5691 the Isabelle inference kernel has been greatly improved;
  5692 
  5693 * print modes "brackets" and "no_brackets" control output of nested =>
  5694 (types) and ==> (props); the default behaviour is "brackets";
  5695 
  5696 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5697 as assumptions as well;
  5698 
  5699 * system: support Poly/ML 4.0;
  5700 
  5701 * system: isatool install handles KDE version 1 or 2;
  5702 
  5703 
  5704 
  5705 New in Isabelle99-1 (October 2000)
  5706 ----------------------------------
  5707 
  5708 *** Overview of INCOMPATIBILITIES ***
  5709 
  5710 * HOL: simplification of natural numbers is much changed; to partly
  5711 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5712 issue the following ML commands:
  5713 
  5714   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5715   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5716 
  5717 * HOL: simplification no longer dives into case-expressions; this is
  5718 controlled by "t.weak_case_cong" for each datatype t;
  5719 
  5720 * HOL: nat_less_induct renamed to less_induct;
  5721 
  5722 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5723 fixsome to patch .thy and .ML sources automatically;
  5724 
  5725   select_equality  -> some_equality
  5726   select_eq_Ex     -> some_eq_ex
  5727   selectI2EX       -> someI2_ex
  5728   selectI2         -> someI2
  5729   selectI          -> someI
  5730   select1_equality -> some1_equality
  5731   Eps_sym_eq       -> some_sym_eq_trivial
  5732   Eps_eq           -> some_eq_trivial
  5733 
  5734 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5735 
  5736 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5737 instead);
  5738 
  5739 * HOL: the recursion equations generated by 'recdef' are now called
  5740 f.simps instead of f.rules;
  5741 
  5742 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5743 
  5744 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5745 sometimes be needed;
  5746 
  5747 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5748 
  5749 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5750 
  5751 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5752 product is now "<*>" instead of "Times"; the lexicographic product is
  5753 now "<*lex*>" instead of "**";
  5754 
  5755 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5756 of main HOL, but was unused); better use HOL's datatype package;
  5757 
  5758 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5759 the old syntax may be recovered as follows:
  5760 
  5761   syntax (symbols)
  5762     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5763       (infixl "\\<oplus>" 100)
  5764 
  5765 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5766 
  5767 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5768 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5769 internally;
  5770 
  5771 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5772 changed from A/r to A//r;
  5773 
  5774 * ZF: new treatment of arithmetic (nat & int) may break some old
  5775 proofs;
  5776 
  5777 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5778 rulify -> rule_format, elimify -> elim_format, ...);
  5779 
  5780 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5781 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5782 should have to change intro!! to intro? only); replaced "delrule" by
  5783 "rule del";
  5784 
  5785 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5786 
  5787 * Provers: strengthened force_tac by using new first_best_tac;
  5788 
  5789 * LaTeX document preparation: several changes of isabelle.sty (see
  5790 lib/texinputs);
  5791 
  5792 
  5793 *** Document preparation ***
  5794 
  5795 * formal comments (text blocks etc.) in new-style theories may now
  5796 contain antiquotations of thm/prop/term/typ/text to be presented
  5797 according to latex print mode; concrete syntax is like this:
  5798 @{term[show_types] "f(x) = a + x"};
  5799 
  5800 * isatool mkdir provides easy setup of Isabelle session directories,
  5801 including proper document sources;
  5802 
  5803 * generated LaTeX sources are now deleted after successful run
  5804 (isatool document -c); may retain a copy somewhere else via -D option
  5805 of isatool usedir;
  5806 
  5807 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5808 style files, achieving self-contained LaTeX sources and simplifying
  5809 LaTeX debugging;
  5810 
  5811 * old-style theories now produce (crude) LaTeX output as well;
  5812 
  5813 * browser info session directories are now self-contained (may be put
  5814 on WWW server seperately); improved graphs of nested sessions; removed
  5815 graph for 'all sessions';
  5816 
  5817 * several improvements in isabelle style files; \isabellestyle{it}
  5818 produces fake math mode output; \isamarkupheader is now \section by
  5819 default; see lib/texinputs/isabelle.sty etc.;
  5820 
  5821 
  5822 *** Isar ***
  5823 
  5824 * Isar/Pure: local results and corresponding term bindings are now
  5825 subject to Hindley-Milner polymorphism (similar to ML); this
  5826 accommodates incremental type-inference very nicely;
  5827 
  5828 * Isar/Pure: new derived language element 'obtain' supports
  5829 generalized existence reasoning;
  5830 
  5831 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5832 support accumulation of results, without applying any rules yet;
  5833 useful to collect intermediate results without explicit name
  5834 references, and for use with transitivity rules with more than 2
  5835 premises;
  5836 
  5837 * Isar/Pure: scalable support for case-analysis type proofs: new
  5838 'case' language element refers to local contexts symbolically, as
  5839 produced by certain proof methods; internally, case names are attached
  5840 to theorems as "tags";
  5841 
  5842 * Isar/Pure: theory command 'hide' removes declarations from
  5843 class/type/const name spaces;
  5844 
  5845 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5846 indicate potential overloading;
  5847 
  5848 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5849 
  5850 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5851 "{a,b,c}" instead of {a,b,c};
  5852 
  5853 * Isar/Pure now provides its own version of intro/elim/dest
  5854 attributes; useful for building new logics, but beware of confusion
  5855 with the version in Provers/classical;
  5856 
  5857 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5858 case name 'antecedent';
  5859 
  5860 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5861 to the current context is now done automatically);
  5862 
  5863 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5864 for definining proof methods in ML;
  5865 
  5866 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5867 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5868 most cases, one should have to change intro!! to intro? only);
  5869 replaced "delrule" by "rule del";
  5870 
  5871 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5872 'symmetric' attribute (the latter supercedes [RS sym]);
  5873 
  5874 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5875 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5876 well (including splits);
  5877 
  5878 * Isar/Provers: Simplifier and Classical methods now support all kind
  5879 of modifiers used in the past, including 'cong', 'iff', etc.
  5880 
  5881 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5882 of Simplifier and Classical reasoner);
  5883 
  5884 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5885 now support named cases; major packages (inductive, datatype, primrec,
  5886 recdef) support case names and properly name parameters;
  5887 
  5888 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5889 monotonicity conditions are extracted to be proven at end of
  5890 calculations;
  5891 
  5892 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5893 method anyway;
  5894 
  5895 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5896 split_if split_if_asm; datatype package provides theorems foo.splits =
  5897 foo.split foo.split_asm for each datatype;
  5898 
  5899 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5900 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5901 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5902 use "(cases (simplified))" method in proper proof texts);
  5903 
  5904 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5905 
  5906 * Isar: names of theorems etc. may be natural numbers as well;
  5907 
  5908 * Isar: 'pr' command: optional arguments for goals_limit and
  5909 ProofContext.prems_limit; no longer prints theory contexts, but only
  5910 proof states;
  5911 
  5912 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5913 additional print modes to be specified; e.g. "pr(latex)" will print
  5914 proof state according to the Isabelle LaTeX style;
  5915 
  5916 * Isar: improved support for emulating tactic scripts, including proof
  5917 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5918 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5919 (for HOL datatypes);
  5920 
  5921 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5922 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5923 'proof method scripts' have to be in depth-first order;
  5924 
  5925 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5926 
  5927 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5928 should instead use individual commands for printing items
  5929 (print_commands, print_methods etc.);
  5930 
  5931 * Isar: added 'nothing' --- the empty list of theorems;
  5932 
  5933 
  5934 *** HOL ***
  5935 
  5936 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5937 corresponding virtual machine and a specification of its bytecode
  5938 verifier and a lightweight bytecode verifier, including proofs of
  5939 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5940 Cornelia Pusch (see also the homepage of project Bali at
  5941 http://isabelle.in.tum.de/Bali/);
  5942 
  5943 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5944 Clemens Ballarin;
  5945 
  5946 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5947 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5948 Rasmussen;
  5949 
  5950 * HOL/Lattice: fundamental concepts of lattice theory and order
  5951 structures, including duals, properties of bounds versus algebraic
  5952 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5953 Theorem for complete lattices etc.; may also serve as a demonstration
  5954 for abstract algebraic reasoning using axiomatic type classes, and
  5955 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5956 
  5957 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5958 von Oheimb;
  5959 
  5960 * HOL/IMPP: extension of IMP with local variables and mutually
  5961 recursive procedures, by David von Oheimb;
  5962 
  5963 * HOL/Lambda: converted into new-style theory and document;
  5964 
  5965 * HOL/ex/Multiquote: example of multiple nested quotations and
  5966 anti-quotations -- basically a generalized version of de-Bruijn
  5967 representation; very useful in avoiding lifting of operations;
  5968 
  5969 * HOL/record: added general record equality rule to simpset; fixed
  5970 select-update simplification procedure to handle extended records as
  5971 well; admit "r" as field name;
  5972 
  5973 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5974 other numeric types and also as the identity of groups, rings, etc.;
  5975 
  5976 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5977 Types nat and int belong to this axclass;
  5978 
  5979 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5980    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5981    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5982   two terms #m*u and #n*u are replaced by #(m+n)*u
  5983     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5984   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5985     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5986 
  5987 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5988 powerful prover for predicate logic but knows nothing of clasets; see
  5989 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5990 
  5991 * HOL: new version of "case_tac" subsumes both boolean case split and
  5992 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5993 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5994 
  5995 * HOL: simplification no longer dives into case-expressions: only the
  5996 selector expression is simplified, but not the remaining arms; to
  5997 enable full simplification of case-expressions for datatype t, you may
  5998 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5999 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6000 
  6001 * HOL/recdef: the recursion equations generated by 'recdef' for
  6002 function 'f' are now called f.simps instead of f.rules; if all
  6003 termination conditions are proved automatically, these simplification
  6004 rules are added to the simpset, as in primrec; rules may be named
  6005 individually as well, resulting in a separate list of theorems for
  6006 each equation;
  6007 
  6008 * HOL/While is a new theory that provides a while-combinator. It
  6009 permits the definition of tail-recursive functions without the
  6010 provision of a termination measure. The latter is necessary once the
  6011 invariant proof rule for while is applied.
  6012 
  6013 * HOL: new (overloaded) notation for the set of elements below/above
  6014 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6015 
  6016 * HOL: theorems impI, allI, ballI bound as "strip";
  6017 
  6018 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6019 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6020 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6021 
  6022 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6023 
  6024 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6025 main HOL, but was unused);
  6026 
  6027 * HOL: fewer consts declared as global (e.g. have to refer to
  6028 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6029 
  6030 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6031 in case of overlap with user translations (e.g. judgements over
  6032 tuples); (note that the underlying logical represenation is still
  6033 bogus);
  6034 
  6035 
  6036 *** ZF ***
  6037 
  6038 * ZF: simplification automatically cancels common terms in arithmetic
  6039 expressions over nat and int;
  6040 
  6041 * ZF: new treatment of nat to minimize type-checking: all operators
  6042 coerce their operands to a natural number using the function natify,
  6043 making the algebraic laws unconditional;
  6044 
  6045 * ZF: as above, for int: operators coerce their operands to an integer
  6046 using the function intify;
  6047 
  6048 * ZF: the integer library now contains many of the usual laws for the
  6049 orderings, including $<=, and monotonicity laws for $+ and $*;
  6050 
  6051 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6052 simplification;
  6053 
  6054 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6055 to the simplifier and classical reasoner simultaneously;
  6056 
  6057 
  6058 *** General ***
  6059 
  6060 * Provers: blast_tac now handles actual object-logic rules as
  6061 assumptions; note that auto_tac uses blast_tac internally as well;
  6062 
  6063 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6064 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6065 
  6066 * Provers: delrules now handles destruct rules as well (no longer need
  6067 explicit make_elim);
  6068 
  6069 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6070   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6071 use instead the strong form,
  6072   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6073 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6074 from destruct-rules;
  6075 
  6076 * Provers: Simplifier.easy_setup provides a fast path to basic
  6077 Simplifier setup for new object-logics;
  6078 
  6079 * Pure: AST translation rules no longer require constant head on LHS;
  6080 
  6081 * Pure: improved name spaces: ambiguous output is qualified; support
  6082 for hiding of names;
  6083 
  6084 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6085 XSYMBOL_HOME; no longer need to do manual configuration in most
  6086 situations;
  6087 
  6088 * system: compression of ML heaps images may now be controlled via -c
  6089 option of isabelle and isatool usedir (currently only observed by
  6090 Poly/ML);
  6091 
  6092 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6093 useful for remote X11);
  6094 
  6095 * system: provide TAGS file for Isabelle sources;
  6096 
  6097 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6098 order;
  6099 
  6100 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6101 timing flag supersedes proof_timing and Toplevel.trace;
  6102 
  6103 * ML: new combinators |>> and |>>> for incremental transformations
  6104 with secondary results (e.g. certain theory extensions):
  6105 
  6106 * ML: PureThy.add_defs gets additional argument to indicate potential
  6107 overloading (usually false);
  6108 
  6109 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6110 results;
  6111 
  6112 
  6113 
  6114 New in Isabelle99 (October 1999)
  6115 --------------------------------
  6116 
  6117 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6118 
  6119 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6120 are no longer simplified.  (This allows the simplifier to unfold recursive
  6121 functional programs.)  To restore the old behaviour, declare
  6122 
  6123     Delcongs [if_weak_cong];
  6124 
  6125 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6126 complement;
  6127 
  6128 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6129 
  6130 * HOL/datatype: mutual_induct_tac no longer exists --
  6131   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6132 
  6133 * HOL/typedef: fixed type inference for representing set; type
  6134 arguments now have to occur explicitly on the rhs as type constraints;
  6135 
  6136 * ZF: The con_defs part of an inductive definition may no longer refer
  6137 to constants declared in the same theory;
  6138 
  6139 * HOL, ZF: the function mk_cases, generated by the inductive
  6140 definition package, has lost an argument.  To simplify its result, it
  6141 uses the default simpset instead of a supplied list of theorems.
  6142 
  6143 * HOL/List: the constructors of type list are now Nil and Cons;
  6144 
  6145 * Simplifier: the type of the infix ML functions
  6146         setSSolver addSSolver setSolver addSolver
  6147 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6148 for packaging solvers. A solver is created via
  6149         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6150 where the string argument is only a comment.
  6151 
  6152 
  6153 *** Proof tools ***
  6154 
  6155 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6156 decision procedure for linear arithmetic. Currently it is used for
  6157 types `nat', `int', and `real' in HOL (see below); it can, should and
  6158 will be instantiated for other types and logics as well.
  6159 
  6160 * The simplifier now accepts rewrite rules with flexible heads, eg
  6161      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6162   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6163   matching.
  6164 
  6165 
  6166 *** General ***
  6167 
  6168 * New Isabelle/Isar subsystem provides an alternative to traditional
  6169 tactical theorem proving; together with the ProofGeneral/isar user
  6170 interface it offers an interactive environment for developing human
  6171 readable proof documents (Isar == Intelligible semi-automated
  6172 reasoning); for further information see isatool doc isar-ref,
  6173 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6174 
  6175 * improved and simplified presentation of theories: better HTML markup
  6176 (including colors), graph views in several sizes; isatool usedir now
  6177 provides a proper interface for user theories (via -P option); actual
  6178 document preparation based on (PDF)LaTeX is available as well (for
  6179 new-style theories only); see isatool doc system for more information;
  6180 
  6181 * native support for Proof General, both for classic Isabelle and
  6182 Isabelle/Isar;
  6183 
  6184 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  6185 using the graph browser tool;
  6186 
  6187 * Isabelle manuals now also available as PDF;
  6188 
  6189 * theory loader rewritten from scratch (may not be fully
  6190 bug-compatible); old loadpath variable has been replaced by show_path,
  6191 add_path, del_path, reset_path functions; new operations such as
  6192 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6193 isatool doc ref);
  6194 
  6195 * improved isatool install: option -k creates KDE application icon,
  6196 option -p DIR installs standalone binaries;
  6197 
  6198 * added ML_PLATFORM setting (useful for cross-platform installations);
  6199 more robust handling of platform specific ML images for SML/NJ;
  6200 
  6201 * the settings environment is now statically scoped, i.e. it is never
  6202 created again in sub-processes invoked from isabelle, isatool, or
  6203 Isabelle;
  6204 
  6205 * path element specification '~~' refers to '$ISABELLE_HOME';
  6206 
  6207 * in locales, the "assumes" and "defines" parts may be omitted if
  6208 empty;
  6209 
  6210 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  6211 long arrows);
  6212 
  6213 * new print_mode "HTML";
  6214 
  6215 * new flag show_tags controls display of tags of theorems (which are
  6216 basically just comments that may be attached by some tools);
  6217 
  6218 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  6219 mode and goal output format:
  6220 
  6221 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  6222 244c244
  6223 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  6224 ---
  6225 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  6226 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  6227 181c181
  6228 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  6229 ---
  6230 > (def