NEWS
author haftmann
Mon Jun 28 15:32:08 2010 +0200 (2010-06-28)
changeset 37596 248db70c9bcf
parent 37595 9591362629e3
child 37608 165cd386288d
permissions -rw-r--r--
dropped ancient infix mem
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** HOL ***
     8 
     9 * Dropped old infix syntax "mem" for List.member;  use "in set"
    10 instead.  INCOMPATIBILITY.
    11 
    12 * Refactoring of code-generation specific operations in List.thy
    13 
    14   constants
    15     null ~> List.null
    16 
    17   facts
    18     mem_iff ~> member_def
    19     null_empty ~> null_def
    20 
    21 INCOMPATIBILITY.  Note that these were not suppossed to be used
    22 regularly unless for striking reasons;  their main purpose was code
    23 generation.
    24 
    25 * Some previously unqualified names have been qualified:
    26 
    27   types
    28     nat ~> Nat.nat
    29     * ~> Product_Type,*
    30     + ~> Sum_Type.+
    31 
    32   constants
    33     Ball ~> Set.Ball
    34     Bex ~> Set.Bex
    35     Suc ~> Nat.Suc
    36     Pair ~> Product_Type.Pair
    37     fst ~> Product_Type.fst
    38     snd ~> Product_Type.snd
    39     split ~> Product_Type.split
    40     curry ~> Product_Type.curry
    41 
    42 INCOMPATIBILITY.
    43 
    44 * Removed simplifier congruence rule of "prod_case", as has for long
    45 been the case with "split".
    46 
    47 * Datatype package: theorems generated for executable equality
    48 (class eq) carry proper names and are treated as default code
    49 equations.
    50 
    51 * List.thy: use various operations from the Haskell prelude when
    52 generating Haskell code.
    53 
    54 * code_simp.ML: simplification with rules determined by
    55 code generator.
    56 
    57 * code generator: do not print function definitions for case
    58 combinators any longer.
    59 
    60 
    61 
    62 New in Isabelle2009-2 (June 2010)
    63 ---------------------------------
    64 
    65 *** General ***
    66 
    67 * Authentic syntax for *all* logical entities (type classes, type
    68 constructors, term constants): provides simple and robust
    69 correspondence between formal entities and concrete syntax.  Within
    70 the parse tree / AST representations, "constants" are decorated by
    71 their category (class, type, const) and spelled out explicitly with
    72 their full internal name.
    73 
    74 Substantial INCOMPATIBILITY concerning low-level syntax declarations
    75 and translations (translation rules and translation functions in ML).
    76 Some hints on upgrading:
    77 
    78   - Many existing uses of 'syntax' and 'translations' can be replaced
    79     by more modern 'type_notation', 'notation' and 'abbreviation',
    80     which are independent of this issue.
    81 
    82   - 'translations' require markup within the AST; the term syntax
    83     provides the following special forms:
    84 
    85       CONST c   -- produces syntax version of constant c from context
    86       XCONST c  -- literally c, checked as constant from context
    87       c         -- literally c, if declared by 'syntax'
    88 
    89     Plain identifiers are treated as AST variables -- occasionally the
    90     system indicates accidental variables via the error "rhs contains
    91     extra variables".
    92 
    93     Type classes and type constructors are marked according to their
    94     concrete syntax.  Some old translations rules need to be written
    95     for the "type" category, using type constructor application
    96     instead of pseudo-term application of the default category
    97     "logic".
    98 
    99   - 'parse_translation' etc. in ML may use the following
   100     antiquotations:
   101 
   102       @{class_syntax c}   -- type class c within parse tree / AST
   103       @{term_syntax c}    -- type constructor c within parse tree / AST
   104       @{const_syntax c}   -- ML version of "CONST c" above
   105       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   106 
   107   - Literal types within 'typed_print_translations', i.e. those *not*
   108     represented as pseudo-terms are represented verbatim.  Use @{class
   109     c} or @{type_name c} here instead of the above syntax
   110     antiquotations.
   111 
   112 Note that old non-authentic syntax was based on unqualified base
   113 names, so all of the above "constant" names would coincide.  Recall
   114 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   115 diagnose syntax problems.
   116 
   117 * Type constructors admit general mixfix syntax, not just infix.
   118 
   119 * Concrete syntax may be attached to local entities without a proof
   120 body, too.  This works via regular mixfix annotations for 'fix',
   121 'def', 'obtain' etc. or via the explicit 'write' command, which is
   122 similar to the 'notation' command in theory specifications.
   123 
   124 * Discontinued unnamed infix syntax (legacy feature for many years) --
   125 need to specify constant name and syntax separately.  Internal ML
   126 datatype constructors have been renamed from InfixName to Infix etc.
   127 Minor INCOMPATIBILITY.
   128 
   129 * Schematic theorem statements need to be explicitly markup as such,
   130 via commands 'schematic_lemma', 'schematic_theorem',
   131 'schematic_corollary'.  Thus the relevance of the proof is made
   132 syntactically clear, which impacts performance in a parallel or
   133 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   134 
   135 * Use of cumulative prems via "!" in some proof methods has been
   136 discontinued (old legacy feature).
   137 
   138 * References 'trace_simp' and 'debug_simp' have been replaced by
   139 configuration options stored in the context. Enabling tracing (the
   140 case of debugging is similar) in proofs works via
   141 
   142   using [[trace_simp = true]]
   143 
   144 Tracing is then active for all invocations of the simplifier in
   145 subsequent goal refinement steps. Tracing may also still be enabled or
   146 disabled via the ProofGeneral settings menu.
   147 
   148 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   149 'hide_fact' replace the former 'hide' KIND command.  Minor
   150 INCOMPATIBILITY.
   151 
   152 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   153 more efficient than combinations with -q1 or -q2.
   154 
   155 
   156 *** Pure ***
   157 
   158 * Proofterms record type-class reasoning explicitly, using the
   159 "unconstrain" operation internally.  This eliminates all sort
   160 constraints from a theorem and proof, introducing explicit
   161 OFCLASS-premises.  On the proof term level, this operation is
   162 automatically applied at theorem boundaries, such that closed proofs
   163 are always free of sort constraints.  INCOMPATIBILITY for tools that
   164 inspect proof terms.
   165 
   166 * Local theory specifications may depend on extra type variables that
   167 are not present in the result type -- arguments TYPE('a) :: 'a itself
   168 are added internally.  For example:
   169 
   170   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   171 
   172 * Predicates of locales introduced by classes carry a mandatory
   173 "class" prefix.  INCOMPATIBILITY.
   174 
   175 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   176 
   177 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   178 'class' instead.
   179 
   180 * Command 'code_reflect' allows to incorporate generated ML code into
   181 runtime environment; replaces immature code_datatype antiquotation.
   182 INCOMPATIBILITY.
   183 
   184 * Code generator: simple concept for abstract datatypes obeying
   185 invariants.
   186 
   187 * Code generator: details of internal data cache have no impact on the
   188 user space functionality any longer.
   189 
   190 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   191 subgoals.  This is more appropriate for interpretations with 'where'.
   192 INCOMPATIBILITY.
   193 
   194 * Command 'example_proof' opens an empty proof body.  This allows to
   195 experiment with Isar, without producing any persistent result.
   196 
   197 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   198 within a local theory context, with explicit checking of the
   199 constructors involved (in contrast to the raw 'syntax' versions).
   200 
   201 * Commands 'types' and 'typedecl' now work within a local theory
   202 context -- without introducing dependencies on parameters or
   203 assumptions, which is not possible in Isabelle/Pure.
   204 
   205 * Command 'defaultsort' has been renamed to 'default_sort', it works
   206 within a local theory context.  Minor INCOMPATIBILITY.
   207 
   208 
   209 *** HOL ***
   210 
   211 * Command 'typedef' now works within a local theory context -- without
   212 introducing dependencies on parameters or assumptions, which is not
   213 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   214 contain multiple interpretations of local typedefs (with different
   215 non-emptiness proofs), even in a global theory context.
   216 
   217 * New package for quotient types.  Commands 'quotient_type' and
   218 'quotient_definition' may be used for defining types and constants by
   219 quotient constructions.  An example is the type of integers created by
   220 quotienting pairs of natural numbers:
   221 
   222   fun
   223     intrel :: "(nat * nat) => (nat * nat) => bool"
   224   where
   225     "intrel (x, y) (u, v) = (x + v = u + y)"
   226 
   227   quotient_type int = "nat * nat" / intrel
   228     by (auto simp add: equivp_def expand_fun_eq)
   229 
   230   quotient_definition
   231     "0::int" is "(0::nat, 0::nat)"
   232 
   233 The method "lifting" can be used to lift of theorems from the
   234 underlying "raw" type to the quotient type.  The example
   235 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   236 construction and provides a reasoning infrastructure for finite sets.
   237 
   238 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   239 clash with new theory Quotient in Main HOL.
   240 
   241 * Moved the SMT binding into the main HOL session, eliminating
   242 separate HOL-SMT session.
   243 
   244 * List membership infix mem operation is only an input abbreviation.
   245 INCOMPATIBILITY.
   246 
   247 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   248 for future developements; former Library/Word.thy is still present in
   249 the AFP entry RSAPPS.
   250 
   251 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   252 longer shadowed.  INCOMPATIBILITY.
   253 
   254 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   255 INCOMPATIBILITY.
   256 
   257 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   258 INCOMPATIBILITY.
   259 
   260 * Dropped normalizing_semiring etc; use the facts in semiring classes
   261 instead.  INCOMPATIBILITY.
   262 
   263 * Dropped several real-specific versions of lemmas about floor and
   264 ceiling; use the generic lemmas from theory "Archimedean_Field"
   265 instead.  INCOMPATIBILITY.
   266 
   267   floor_number_of_eq         ~> floor_number_of
   268   le_floor_eq_number_of      ~> number_of_le_floor
   269   le_floor_eq_zero           ~> zero_le_floor
   270   le_floor_eq_one            ~> one_le_floor
   271   floor_less_eq_number_of    ~> floor_less_number_of
   272   floor_less_eq_zero         ~> floor_less_zero
   273   floor_less_eq_one          ~> floor_less_one
   274   less_floor_eq_number_of    ~> number_of_less_floor
   275   less_floor_eq_zero         ~> zero_less_floor
   276   less_floor_eq_one          ~> one_less_floor
   277   floor_le_eq_number_of      ~> floor_le_number_of
   278   floor_le_eq_zero           ~> floor_le_zero
   279   floor_le_eq_one            ~> floor_le_one
   280   floor_subtract_number_of   ~> floor_diff_number_of
   281   floor_subtract_one         ~> floor_diff_one
   282   ceiling_number_of_eq       ~> ceiling_number_of
   283   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   284   ceiling_le_zero_eq         ~> ceiling_le_zero
   285   ceiling_le_eq_one          ~> ceiling_le_one
   286   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   287   less_ceiling_eq_zero       ~> zero_less_ceiling
   288   less_ceiling_eq_one        ~> one_less_ceiling
   289   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   290   ceiling_less_eq_zero       ~> ceiling_less_zero
   291   ceiling_less_eq_one        ~> ceiling_less_one
   292   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   293   le_ceiling_eq_zero         ~> zero_le_ceiling
   294   le_ceiling_eq_one          ~> one_le_ceiling
   295   ceiling_subtract_number_of ~> ceiling_diff_number_of
   296   ceiling_subtract_one       ~> ceiling_diff_one
   297 
   298 * Theory "Finite_Set": various folding_XXX locales facilitate the
   299 application of the various fold combinators on finite sets.
   300 
   301 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   302 provides abstract red-black tree type which is backed by "RBT_Impl" as
   303 implementation.  INCOMPATIBILTY.
   304 
   305 * Theory Library/Coinductive_List has been removed -- superseded by
   306 AFP/thys/Coinductive.
   307 
   308 * Theory PReal, including the type "preal" and related operations, has
   309 been removed.  INCOMPATIBILITY.
   310 
   311 * Real: new development using Cauchy Sequences.
   312 
   313 * Split off theory "Big_Operators" containing setsum, setprod,
   314 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   315 
   316 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   317 "Int" etc.  INCOMPATIBILITY.
   318 
   319 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   320 
   321 * New set of rules "ac_simps" provides combined assoc / commute
   322 rewrites for all interpretations of the appropriate generic locales.
   323 
   324 * Renamed theory "OrderedGroup" to "Groups" and split theory
   325 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   326 appropriate and more consistent names suitable for name prefixes
   327 within the HOL theories.  INCOMPATIBILITY.
   328 
   329 * Some generic constants have been put to appropriate theories:
   330   - less_eq, less: Orderings
   331   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   332   - inverse, divide: Rings
   333 INCOMPATIBILITY.
   334 
   335 * More consistent naming of type classes involving orderings (and
   336 lattices):
   337 
   338     lower_semilattice                   ~> semilattice_inf
   339     upper_semilattice                   ~> semilattice_sup
   340 
   341     dense_linear_order                  ~> dense_linorder
   342 
   343     pordered_ab_group_add               ~> ordered_ab_group_add
   344     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   345     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   346     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   347     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   348     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   349     pordered_cancel_semiring            ~> ordered_cancel_semiring
   350     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   351     pordered_comm_ring                  ~> ordered_comm_ring
   352     pordered_comm_semiring              ~> ordered_comm_semiring
   353     pordered_ring                       ~> ordered_ring
   354     pordered_ring_abs                   ~> ordered_ring_abs
   355     pordered_semiring                   ~> ordered_semiring
   356 
   357     ordered_ab_group_add                ~> linordered_ab_group_add
   358     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   359     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   360     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   361     ordered_field                       ~> linordered_field
   362     ordered_field_no_lb                 ~> linordered_field_no_lb
   363     ordered_field_no_ub                 ~> linordered_field_no_ub
   364     ordered_field_dense_linear_order    ~> dense_linordered_field
   365     ordered_idom                        ~> linordered_idom
   366     ordered_ring                        ~> linordered_ring
   367     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   368     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   369     ordered_ring_strict                 ~> linordered_ring_strict
   370     ordered_semidom                     ~> linordered_semidom
   371     ordered_semiring                    ~> linordered_semiring
   372     ordered_semiring_1                  ~> linordered_semiring_1
   373     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   374     ordered_semiring_strict             ~> linordered_semiring_strict
   375 
   376   The following slightly odd type classes have been moved to a
   377   separate theory Library/Lattice_Algebras:
   378 
   379     lordered_ab_group_add               ~> lattice_ab_group_add
   380     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   381     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   382     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   383     lordered_ring                       ~> lattice_ring
   384 
   385 INCOMPATIBILITY.
   386 
   387 * Refined field classes:
   388   - classes division_ring_inverse_zero, field_inverse_zero,
   389     linordered_field_inverse_zero include rule inverse 0 = 0 --
   390     subsumes former division_by_zero class;
   391   - numerous lemmas have been ported from field to division_ring.
   392 INCOMPATIBILITY.
   393 
   394 * Refined algebra theorem collections:
   395   - dropped theorem group group_simps, use algebra_simps instead;
   396   - dropped theorem group ring_simps, use field_simps instead;
   397   - proper theorem collection field_simps subsumes former theorem
   398     groups field_eq_simps and field_simps;
   399   - dropped lemma eq_minus_self_iff which is a duplicate for
   400     equal_neg_zero.
   401 INCOMPATIBILITY.
   402 
   403 * Theory Finite_Set and List: some lemmas have been generalized from
   404 sets to lattices:
   405 
   406   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   407   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   408   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   409   union_Union_fold_union        ~> sup_Sup_fold_sup
   410   Inter_fold_inter              ~> Inf_fold_inf
   411   Union_fold_union              ~> Sup_fold_sup
   412   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   413   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   414   INTER_fold_inter              ~> INFI_fold_inf
   415   UNION_fold_union              ~> SUPR_fold_sup
   416 
   417 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   418 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   419 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   420 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   421 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   422 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   423 
   424 * Reorganized theory Multiset: swapped notation of pointwise and
   425 multiset order:
   426 
   427   - pointwise ordering is instance of class order with standard syntax
   428     <= and <;
   429   - multiset ordering has syntax <=# and <#; partial order properties
   430     are provided by means of interpretation with prefix
   431     multiset_order;
   432   - less duplication, less historical organization of sections,
   433     conversion from associations lists to multisets, rudimentary code
   434     generation;
   435   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   436     if needed.
   437 
   438 Renamed:
   439 
   440   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   441   multi_count_ext  ~>  multiset_ext
   442   diff_union_inverse2  ~>  diff_union_cancelR
   443 
   444 INCOMPATIBILITY.
   445 
   446 * Theory Permutation: replaced local "remove" by List.remove1.
   447 
   448 * Code generation: ML and OCaml code is decorated with signatures.
   449 
   450 * Theory List: added transpose.
   451 
   452 * Library/Nat_Bijection.thy is a collection of bijective functions
   453 between nat and other types, which supersedes the older libraries
   454 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   455 
   456   Constants:
   457   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   458   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   459   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   460   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   461   Countable.pair_encode           ~> prod_encode
   462   NatIso.prod2nat                 ~> prod_encode
   463   NatIso.nat2prod                 ~> prod_decode
   464   NatIso.sum2nat                  ~> sum_encode
   465   NatIso.nat2sum                  ~> sum_decode
   466   NatIso.list2nat                 ~> list_encode
   467   NatIso.nat2list                 ~> list_decode
   468   NatIso.set2nat                  ~> set_encode
   469   NatIso.nat2set                  ~> set_decode
   470 
   471   Lemmas:
   472   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   473   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   474   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   475   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   476   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   477   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   478   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   479   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   480   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   481   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   482   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   483   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   484   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   485 
   486 * Sledgehammer:
   487   - Renamed ATP commands:
   488     atp_info     ~> sledgehammer running_atps
   489     atp_kill     ~> sledgehammer kill_atps
   490     atp_messages ~> sledgehammer messages
   491     atp_minimize ~> sledgehammer minimize
   492     print_atps   ~> sledgehammer available_atps
   493     INCOMPATIBILITY.
   494   - Added user's manual ("isabelle doc sledgehammer").
   495   - Added option syntax and "sledgehammer_params" to customize
   496     Sledgehammer's behavior.  See the manual for details.
   497   - Modified the Isar proof reconstruction code so that it produces
   498     direct proofs rather than proofs by contradiction.  (This feature
   499     is still experimental.)
   500   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   501     full-typed mode.
   502   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   503 
   504 * Nitpick:
   505   - Added and implemented "binary_ints" and "bits" options.
   506   - Added "std" option and implemented support for nonstandard models.
   507   - Added and implemented "finitize" option to improve the precision
   508     of infinite datatypes based on a monotonicity analysis.
   509   - Added support for quotient types.
   510   - Added support for "specification" and "ax_specification"
   511     constructs.
   512   - Added support for local definitions (for "function" and
   513     "termination" proofs).
   514   - Added support for term postprocessors.
   515   - Optimized "Multiset.multiset" and "FinFun.finfun".
   516   - Improved efficiency of "destroy_constrs" optimization.
   517   - Fixed soundness bugs related to "destroy_constrs" optimization and
   518     record getters.
   519   - Fixed soundness bug related to higher-order constructors.
   520   - Fixed soundness bug when "full_descrs" is enabled.
   521   - Improved precision of set constructs.
   522   - Added "atoms" option.
   523   - Added cache to speed up repeated Kodkod invocations on the same
   524     problems.
   525   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   526     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   527     "SAT4J_Light".  INCOMPATIBILITY.
   528   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   529     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   530   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   531 
   532 * Method "induct" now takes instantiations of the form t, where t is not
   533   a variable, as a shorthand for "x == t", where x is a fresh variable.
   534   If this is not intended, t has to be enclosed in parentheses.
   535   By default, the equalities generated by definitional instantiations
   536   are pre-simplified, which may cause parameters of inductive cases
   537   to disappear, or may even delete some of the inductive cases.
   538   Use "induct (no_simp)" instead of "induct" to restore the old
   539   behaviour. The (no_simp) option is also understood by the "cases"
   540   and "nominal_induct" methods, which now perform pre-simplification, too.
   541   INCOMPATIBILITY.
   542 
   543 
   544 *** HOLCF ***
   545 
   546 * Variable names in lemmas generated by the domain package have
   547 changed; the naming scheme is now consistent with the HOL datatype
   548 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   549 
   550 * The domain package no longer defines the function "foo_copy" for
   551 recursive domain "foo".  The reach lemma is now stated directly in
   552 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   553 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   554 
   555 * Most definedness lemmas generated by the domain package (previously
   556 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   557 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   558 Proofs that used definedness lemmas as intro rules may break,
   559 potential INCOMPATIBILITY.
   560 
   561 * Induction and casedist rules generated by the domain package now
   562 declare proper case_names (one called "bottom", and one named for each
   563 constructor).  INCOMPATIBILITY.
   564 
   565 * For mutually-recursive domains, separate "reach" and "take_lemma"
   566 rules are generated for each domain, INCOMPATIBILITY.
   567 
   568   foo_bar.reach       ~> foo.reach  bar.reach
   569   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   570 
   571 * Some lemmas generated by the domain package have been renamed for
   572 consistency with the datatype package, INCOMPATIBILITY.
   573 
   574   foo.ind        ~> foo.induct
   575   foo.finite_ind ~> foo.finite_induct
   576   foo.coind      ~> foo.coinduct
   577   foo.casedist   ~> foo.exhaust
   578   foo.exhaust    ~> foo.nchotomy
   579 
   580 * For consistency with other definition packages, the fixrec package
   581 now generates qualified theorem names, INCOMPATIBILITY.
   582 
   583   foo_simps  ~> foo.simps
   584   foo_unfold ~> foo.unfold
   585   foo_induct ~> foo.induct
   586 
   587 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   588 method and internal fixrec proofs now use the default simpset instead.
   589 INCOMPATIBILITY.
   590 
   591 * The "contlub" predicate has been removed.  Proof scripts should use
   592 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   593 
   594 * The "admw" predicate has been removed, INCOMPATIBILITY.
   595 
   596 * The constants cpair, cfst, and csnd have been removed in favor of
   597 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   598 
   599 
   600 *** ML ***
   601 
   602 * Antiquotations for basic formal entities:
   603 
   604     @{class NAME}         -- type class
   605     @{class_syntax NAME}  -- syntax representation of the above
   606 
   607     @{type_name NAME}     -- logical type
   608     @{type_abbrev NAME}   -- type abbreviation
   609     @{nonterminal NAME}   -- type of concrete syntactic category
   610     @{type_syntax NAME}   -- syntax representation of any of the above
   611 
   612     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   613     @{const_abbrev NAME}  -- abbreviated constant
   614     @{const_syntax NAME}  -- syntax representation of any of the above
   615 
   616 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   617 syntax constant (cf. 'syntax' command).
   618 
   619 * Antiquotation @{make_string} inlines a function to print arbitrary
   620 values similar to the ML toplevel.  The result is compiler dependent
   621 and may fall back on "?" in certain situations.
   622 
   623 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   624 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   625 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   626 not work with the asynchronous Isar document model.
   627 
   628 * Configuration options now admit dynamic default values, depending on
   629 the context or even global references.
   630 
   631 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   632 uses an efficient external library if available (for Poly/ML).
   633 
   634 * Renamed some important ML structures, while keeping the old names
   635 for some time as aliases within the structure Legacy:
   636 
   637   OuterKeyword  ~>  Keyword
   638   OuterLex      ~>  Token
   639   OuterParse    ~>  Parse
   640   OuterSyntax   ~>  Outer_Syntax
   641   PrintMode     ~>  Print_Mode
   642   SpecParse     ~>  Parse_Spec
   643   ThyInfo       ~>  Thy_Info
   644   ThyLoad       ~>  Thy_Load
   645   ThyOutput     ~>  Thy_Output
   646   TypeInfer     ~>  Type_Infer
   647 
   648 Note that "open Legacy" simplifies porting of sources, but forgetting
   649 to remove it again will complicate porting again in the future.
   650 
   651 * Most operations that refer to a global context are named
   652 accordingly, e.g. Simplifier.global_context or
   653 ProofContext.init_global.  There are some situations where a global
   654 context actually works, but under normal circumstances one needs to
   655 pass the proper local context through the code!
   656 
   657 * Discontinued old TheoryDataFun with its copy/init operation -- data
   658 needs to be pure.  Functor Theory_Data_PP retains the traditional
   659 Pretty.pp argument to merge, which is absent in the standard
   660 Theory_Data version.
   661 
   662 * Sorts.certify_sort and derived "cert" operations for types and terms
   663 no longer minimize sorts.  Thus certification at the boundary of the
   664 inference kernel becomes invariant under addition of class relations,
   665 which is an important monotonicity principle.  Sorts are now minimized
   666 in the syntax layer only, at the boundary between the end-user and the
   667 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   668 explicitly in rare situations.
   669 
   670 * Renamed old-style Drule.standard to Drule.export_without_context, to
   671 emphasize that this is in no way a standard operation.
   672 INCOMPATIBILITY.
   673 
   674 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   675 usual for resolution.  Rare INCOMPATIBILITY.
   676 
   677 * Renamed varify/unvarify operations to varify_global/unvarify_global
   678 to emphasize that these only work in a global situation (which is
   679 quite rare).
   680 
   681 * Curried take and drop in library.ML; negative length is interpreted
   682 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   683 
   684 * Proof terms: type substitutions on proof constants now use canonical
   685 order of type variables.  INCOMPATIBILITY for tools working with proof
   686 terms.
   687 
   688 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   689 may no longer carry premises.  User-level specifications are
   690 transformed accordingly by Thm.add_axiom/add_def.
   691 
   692 
   693 *** System ***
   694 
   695 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   696 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   697 proof terms are enabled unconditionally in the new HOL-Proofs image.
   698 
   699 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   700 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   701 respectively.
   702 
   703 * Old lib/scripts/polyml-platform is superseded by the
   704 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   705 variant, even on a 64 bit machine.  The following example setting
   706 prefers 64 bit if available:
   707 
   708   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   709 
   710 * The preliminary Isabelle/jEdit application demonstrates the emerging
   711 Isabelle/Scala layer for advanced prover interaction and integration.
   712 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   713 component.
   714 
   715 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   716 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   717 similar to the default assignment of the document preparation system
   718 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   719 provides some operations for direct access to the font without asking
   720 the user for manual installation.
   721 
   722 
   723 
   724 New in Isabelle2009-1 (December 2009)
   725 -------------------------------------
   726 
   727 *** General ***
   728 
   729 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   730 one backslash should be used, even in ML sources.
   731 
   732 
   733 *** Pure ***
   734 
   735 * Locale interpretation propagates mixins along the locale hierarchy.
   736 The currently only available mixins are the equations used to map
   737 local definitions to terms of the target domain of an interpretation.
   738 
   739 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   740 loc" to print all interpretations of locale "loc" in the theory.
   741 Interpretations in proofs are not shown.
   742 
   743 * Thoroughly revised locales tutorial.  New section on conditional
   744 interpretation.
   745 
   746 * On instantiation of classes, remaining undefined class parameters
   747 are formally declared.  INCOMPATIBILITY.
   748 
   749 
   750 *** Document preparation ***
   751 
   752 * New generalized style concept for printing terms: @{foo (style) ...}
   753 instead of @{foo_style style ...}  (old form is still retained for
   754 backward compatibility).  Styles can be also applied for
   755 antiquotations prop, term_type and typeof.
   756 
   757 
   758 *** HOL ***
   759 
   760 * New proof method "smt" for a combination of first-order logic with
   761 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   762 fixed-size bitvectors; there is also basic support for higher-order
   763 features (esp. lambda abstractions).  It is an incomplete decision
   764 procedure based on external SMT solvers using the oracle mechanism;
   765 for the SMT solver Z3, this method is proof-producing.  Certificates
   766 are provided to avoid calling the external solvers solely for
   767 re-checking proofs.  Due to a remote SMT service there is no need for
   768 installing SMT solvers locally.  See src/HOL/SMT.
   769 
   770 * New commands to load and prove verification conditions generated by
   771 the Boogie program verifier or derived systems (e.g. the Verifying C
   772 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   773 
   774 * New counterexample generator tool 'nitpick' based on the Kodkod
   775 relational model finder.  See src/HOL/Tools/Nitpick and
   776 src/HOL/Nitpick_Examples.
   777 
   778 * New commands 'code_pred' and 'values' to invoke the predicate
   779 compiler and to enumerate values of inductive predicates.
   780 
   781 * A tabled implementation of the reflexive transitive closure.
   782 
   783 * New implementation of quickcheck uses generic code generator;
   784 default generators are provided for all suitable HOL types, records
   785 and datatypes.  Old quickcheck can be re-activated importing theory
   786 Library/SML_Quickcheck.
   787 
   788 * New testing tool Mirabelle for automated proof tools.  Applies
   789 several tools and tactics like sledgehammer, metis, or quickcheck, to
   790 every proof step in a theory.  To be used in batch mode via the
   791 "mirabelle" utility.
   792 
   793 * New proof method "sos" (sum of squares) for nonlinear real
   794 arithmetic (originally due to John Harison). It requires theory
   795 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   796 works well in practice on quantifier-free real arithmetic with +, -,
   797 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   798 inequalities between polynomials.  It makes use of external
   799 semidefinite programming solvers.  Method "sos" generates a
   800 certificate that can be pasted into the proof thus avoiding the need
   801 to call an external tool every time the proof is checked.  See
   802 src/HOL/Library/Sum_Of_Squares.
   803 
   804 * New method "linarith" invokes existing linear arithmetic decision
   805 procedure only.
   806 
   807 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   808 
   809 * New Sledgehammer option "Full Types" in Proof General settings menu.
   810 Causes full type information to be output to the ATPs.  This slows
   811 ATPs down considerably but eliminates a source of unsound "proofs"
   812 that fail later.
   813 
   814 * New method "metisFT": A version of metis that uses full type
   815 information in order to avoid failures of proof reconstruction.
   816 
   817 * New evaluator "approximate" approximates an real valued term using
   818 the same method as the approximation method.
   819 
   820 * Method "approximate" now supports arithmetic expressions as
   821 boundaries of intervals and implements interval splitting and Taylor
   822 series expansion.
   823 
   824 * ML antiquotation @{code_datatype} inserts definition of a datatype
   825 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   826 
   827 * New theory SupInf of the supremum and infimum operators for sets of
   828 reals.
   829 
   830 * New theory Probability, which contains a development of measure
   831 theory, eventually leading to Lebesgue integration and probability.
   832 
   833 * Extended Multivariate Analysis to include derivation and Brouwer's
   834 fixpoint theorem.
   835 
   836 * Reorganization of number theory, INCOMPATIBILITY:
   837   - new number theory development for nat and int, in theories Divides
   838     and GCD as well as in new session Number_Theory
   839   - some constants and facts now suffixed with _nat and _int
   840     accordingly
   841   - former session NumberTheory now named Old_Number_Theory, including
   842     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   843   - moved theory Pocklington from src/HOL/Library to
   844     src/HOL/Old_Number_Theory
   845 
   846 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   847 lcm of finite and infinite sets. It is shown that they form a complete
   848 lattice.
   849 
   850 * Class semiring_div requires superclass no_zero_divisors and proof of
   851 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   852 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   853 generalized to class semiring_div, subsuming former theorems
   854 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   855 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   856 INCOMPATIBILITY.
   857 
   858 * Refinements to lattice classes and sets:
   859   - less default intro/elim rules in locale variant, more default
   860     intro/elim rules in class variant: more uniformity
   861   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   862     le_inf_iff
   863   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   864     sup_aci)
   865   - renamed ACI to inf_sup_aci
   866   - new class "boolean_algebra"
   867   - class "complete_lattice" moved to separate theory
   868     "Complete_Lattice"; corresponding constants (and abbreviations)
   869     renamed and with authentic syntax:
   870     Set.Inf ~>    Complete_Lattice.Inf
   871     Set.Sup ~>    Complete_Lattice.Sup
   872     Set.INFI ~>   Complete_Lattice.INFI
   873     Set.SUPR ~>   Complete_Lattice.SUPR
   874     Set.Inter ~>  Complete_Lattice.Inter
   875     Set.Union ~>  Complete_Lattice.Union
   876     Set.INTER ~>  Complete_Lattice.INTER
   877     Set.UNION ~>  Complete_Lattice.UNION
   878   - authentic syntax for
   879     Set.Pow
   880     Set.image
   881   - mere abbreviations:
   882     Set.empty               (for bot)
   883     Set.UNIV                (for top)
   884     Set.inter               (for inf, formerly Set.Int)
   885     Set.union               (for sup, formerly Set.Un)
   886     Complete_Lattice.Inter  (for Inf)
   887     Complete_Lattice.Union  (for Sup)
   888     Complete_Lattice.INTER  (for INFI)
   889     Complete_Lattice.UNION  (for SUPR)
   890   - object-logic definitions as far as appropriate
   891 
   892 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   893 Un_subset_iff are explicitly deleted as default simp rules; then also
   894 their lattice counterparts le_inf_iff and le_sup_iff have to be
   895 deleted to achieve the desired effect.
   896 
   897 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   898 rules by default any longer; the same applies to min_max.inf_absorb1
   899 etc.  INCOMPATIBILITY.
   900 
   901 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   902 pred_set_conv by default.  INCOMPATIBILITY.
   903 
   904 * Power operations on relations and functions are now one dedicated
   905 constant "compow" with infix syntax "^^".  Power operation on
   906 multiplicative monoids retains syntax "^" and is now defined generic
   907 in class power.  INCOMPATIBILITY.
   908 
   909 * Relation composition "R O S" now has a more standard argument order:
   910 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   911 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   912 break, since the O_assoc rule was not rewritten like this.  Fix using
   913 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   914 
   915 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   916 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   917 INCOMPATIBILITY.
   918 
   919 * Most rules produced by inductive and datatype package have mandatory
   920 prefixes.  INCOMPATIBILITY.
   921 
   922 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   923 the attribute of the same name.  Each of the theorems in the list
   924 DERIV_intros assumes composition with an additional function and
   925 matches a variable to the derivative, which has to be solved by the
   926 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   927 of most elementary terms.  Former Maclauren.DERIV_tac and
   928 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   929 INCOMPATIBILITY.
   930 
   931 * Code generator attributes follow the usual underscore convention:
   932     code_unfold     replaces    code unfold
   933     code_post       replaces    code post
   934     etc.
   935   INCOMPATIBILITY.
   936 
   937 * Renamed methods:
   938     sizechange -> size_change
   939     induct_scheme -> induction_schema
   940   INCOMPATIBILITY.
   941 
   942 * Discontinued abbreviation "arbitrary" of constant "undefined".
   943 INCOMPATIBILITY, use "undefined" directly.
   944 
   945 * Renamed theorems:
   946     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   947     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   948     Suc_plus1 -> Suc_eq_plus1
   949     *anti_sym -> *antisym*
   950     vector_less_eq_def -> vector_le_def
   951   INCOMPATIBILITY.
   952 
   953 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   954 INCOMPATIBILITY.
   955 
   956 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   957 INCOMPATIBILITY.
   958 
   959 
   960 *** HOLCF ***
   961 
   962 * Theory Representable defines a class "rep" of domains that are
   963 representable (via an ep-pair) in the universal domain type "udom".
   964 Instances are provided for all type constructors defined in HOLCF.
   965 
   966 * The 'new_domain' command is a purely definitional version of the
   967 domain package, for representable domains.  Syntax is identical to the
   968 old domain package.  The 'new_domain' package also supports indirect
   969 recursion using previously-defined type constructors.  See
   970 src/HOLCF/ex/New_Domain.thy for examples.
   971 
   972 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   973 on the left-hand side of an equation, and then performs
   974 simplification.  Rewriting is done using rules declared with the
   975 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   976 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   977 
   978 * The pattern-match compiler in 'fixrec' can now handle constructors
   979 with HOL function types.  Pattern-match combinators for the Pair
   980 constructor are pre-configured.
   981 
   982 * The 'fixrec' package now produces better fixed-point induction rules
   983 for mutually-recursive definitions:  Induction rules have conclusions
   984 of the form "P foo bar" instead of "P <foo, bar>".
   985 
   986 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   987 been renamed to "below".  The name "below" now replaces "less" in many
   988 theorem names.  (Legacy theorem names using "less" are still supported
   989 as well.)
   990 
   991 * The 'fixrec' package now supports "bottom patterns".  Bottom
   992 patterns can be used to generate strictness rules, or to make
   993 functions more strict (much like the bang-patterns supported by the
   994 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   995 examples.
   996 
   997 
   998 *** ML ***
   999 
  1000 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1001 errors and run-time exceptions, including detailed source positions.
  1002 
  1003 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1004 identified entries, with some additional information such as source
  1005 position, logical grouping etc.
  1006 
  1007 * Theory and context data is now introduced by the simplified and
  1008 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1009 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1010 copy operation) is still available for some time.
  1011 
  1012 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1013 provides a high-level programming interface to synchronized state
  1014 variables with atomic update.  This works via pure function
  1015 application within a critical section -- its runtime should be as
  1016 short as possible; beware of deadlocks if critical code is nested,
  1017 either directly or indirectly via other synchronized variables!
  1018 
  1019 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1020 wraps raw ML references, explicitly indicating their non-thread-safe
  1021 behaviour.  The Isar toplevel keeps this structure open, to
  1022 accommodate Proof General as well as quick and dirty interactive
  1023 experiments with references.
  1024 
  1025 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1026 parallel tactical reasoning.
  1027 
  1028 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1029 are similar to SUBPROOF, but are slightly more flexible: only the
  1030 specified parts of the subgoal are imported into the context, and the
  1031 body tactic may introduce new subgoals and schematic variables.
  1032 
  1033 * Old tactical METAHYPS, which does not observe the proof context, has
  1034 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1035 or Subgoal.FOCUS etc.
  1036 
  1037 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1038 functors have their own ML name space there is no point to mark them
  1039 separately.)  Minor INCOMPATIBILITY.
  1040 
  1041 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1042 
  1043 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1044 INCOMPATIBILITY.
  1045 
  1046 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1047 mode, which avoids critical setmp.
  1048 
  1049 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1050 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1051 Attrib/Method.setup introduced in Isabelle2009.
  1052 
  1053 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1054 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1055 last resort.  INCOMPATIBILITY.
  1056 
  1057 * Display.pretty_thm now requires a proper context (cf. former
  1058 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1059 or even Display.pretty_thm_without_context as last resort.
  1060 INCOMPATIBILITY.
  1061 
  1062 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1063 Syntax.pretty_typ/term directly, preferably with proper context
  1064 instead of global theory.
  1065 
  1066 
  1067 *** System ***
  1068 
  1069 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1070 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1071 usedir option -q.
  1072 
  1073 * Support for additional "Isabelle components" via etc/components, see
  1074 also the system manual.
  1075 
  1076 * The isabelle makeall tool now operates on all components with
  1077 IsaMakefile, not just hardwired "logics".
  1078 
  1079 * Removed "compress" option from isabelle-process and isabelle usedir;
  1080 this is always enabled.
  1081 
  1082 * Discontinued support for Poly/ML 4.x versions.
  1083 
  1084 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1085 on a given logic image.  This requires the lighttpd webserver and is
  1086 currently supported on Linux only.
  1087 
  1088 
  1089 
  1090 New in Isabelle2009 (April 2009)
  1091 --------------------------------
  1092 
  1093 *** General ***
  1094 
  1095 * Simplified main Isabelle executables, with less surprises on
  1096 case-insensitive file-systems (such as Mac OS).
  1097 
  1098   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1099     "isatool."
  1100 
  1101   - The former "isabelle" alias for "isabelle-process" has been
  1102     removed (should rarely occur to regular users).
  1103 
  1104   - The former "isabelle-interface" and its alias "Isabelle" have been
  1105     removed (interfaces are now regular Isabelle tools).
  1106 
  1107 Within scripts and make files, the Isabelle environment variables
  1108 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1109 respectively.  (The latter are still available as legacy feature.)
  1110 
  1111 The old isabelle-interface wrapper could react in confusing ways if
  1112 the interface was uninstalled or changed otherwise.  Individual
  1113 interface tool configuration is now more explicit, see also the
  1114 Isabelle system manual.  In particular, Proof General is now available
  1115 via "isabelle emacs".
  1116 
  1117 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1118 purge installed copies of Isabelle executables and re-run "isabelle
  1119 install -p ...", or use symlinks.
  1120 
  1121 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1122 old ~/isabelle, which was slightly non-standard and apt to cause
  1123 surprises on case-insensitive file-systems (such as Mac OS).
  1124 
  1125 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1126 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1127 care is required when using older releases of Isabelle.  Note that
  1128 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1129 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1130 
  1131 * Proofs of fully specified statements are run in parallel on
  1132 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1133 a regular 4-core machine, if the initial heap space is made reasonably
  1134 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1135 
  1136 * The main reference manuals ("isar-ref", "implementation", and
  1137 "system") have been updated and extended.  Formally checked references
  1138 as hyperlinks are now available uniformly.
  1139 
  1140 
  1141 *** Pure ***
  1142 
  1143 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1144 respects.  The most important changes are listed below.  See the
  1145 Tutorial on Locales ("locales" manual) for details.
  1146 
  1147 - In locale expressions, instantiation replaces renaming.  Parameters
  1148 must be declared in a for clause.  To aid compatibility with previous
  1149 parameter inheritance, in locale declarations, parameters that are not
  1150 'touched' (instantiation position "_" or omitted) are implicitly added
  1151 with their syntax at the beginning of the for clause.
  1152 
  1153 - Syntax from abbreviations and definitions in locales is available in
  1154 locale expressions and context elements.  The latter is particularly
  1155 useful in locale declarations.
  1156 
  1157 - More flexible mechanisms to qualify names generated by locale
  1158 expressions.  Qualifiers (prefixes) may be specified in locale
  1159 expressions, and can be marked as mandatory (syntax: "name!:") or
  1160 optional (syntax "name?:").  The default depends for plain "name:"
  1161 depends on the situation where a locale expression is used: in
  1162 commands 'locale' and 'sublocale' prefixes are optional, in
  1163 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1164 implicit qualifiers derived from the parameter names of a locale are
  1165 no longer generated.
  1166 
  1167 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1168 instantiation clause in "interpretation" and "interpret" (square
  1169 brackets) is no longer available.  Use locale expressions.
  1170 
  1171 - When converting proof scripts, mandatory qualifiers in
  1172 'interpretation' and 'interpret' should be retained by default, even
  1173 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1174 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1175 in locale expressions range over a single locale instance only.
  1176 
  1177 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1178 In existing theorem specifications replace the includes element by the
  1179 respective context elements of the included locale, omitting those
  1180 that are already present in the theorem specification.  Multiple
  1181 assume elements of a locale should be replaced by a single one
  1182 involving the locale predicate.  In the proof body, declarations (most
  1183 notably theorems) may be regained by interpreting the respective
  1184 locales in the proof context as required (command "interpret").
  1185 
  1186 If using "includes" in replacement of a target solely because the
  1187 parameter types in the theorem are not as general as in the target,
  1188 consider declaring a new locale with additional type constraints on
  1189 the parameters (context element "constrains").
  1190 
  1191 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1192 
  1193 - Locale interpretation commands no longer attempt to simplify goal.
  1194 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1195 methods intro_locales and unfold_locales to clarify.
  1196 
  1197 - Locale interpretation commands no longer accept interpretation
  1198 attributes.  INCOMPATIBILITY.
  1199 
  1200 * Class declaration: so-called "base sort" must not be given in import
  1201 list any longer, but is inferred from the specification.  Particularly
  1202 in HOL, write
  1203 
  1204     class foo = ...
  1205 
  1206 instead of
  1207 
  1208     class foo = type + ...
  1209 
  1210 * Class target: global versions of theorems stemming do not carry a
  1211 parameter prefix any longer.  INCOMPATIBILITY.
  1212 
  1213 * Class 'instance' command no longer accepts attached definitions.
  1214 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1215 
  1216 * Recovered hiding of consts, which was accidentally broken in
  1217 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1218 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1219 
  1220 * Slightly more coherent Pure syntax, with updated documentation in
  1221 isar-ref manual.  Removed locales meta_term_syntax and
  1222 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1223 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1224 directly in regular applications.
  1225 
  1226 * There is a new syntactic category "float_const" for signed decimal
  1227 fractions (e.g. 123.45 or -123.45).
  1228 
  1229 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1230 interface with 'setup' command instead.
  1231 
  1232 * Command 'local_setup' is similar to 'setup', but operates on a local
  1233 theory context.
  1234 
  1235 * The 'axiomatization' command now only works within a global theory
  1236 context.  INCOMPATIBILITY.
  1237 
  1238 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1239 hypotheses.  Sorts required in the course of reasoning need to be
  1240 covered by the constraints in the initial statement, completed by the
  1241 type instance information of the background theory.  Non-trivial sort
  1242 hypotheses, which rarely occur in practice, may be specified via
  1243 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1244 
  1245   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1246 
  1247 The result contains an implicit sort hypotheses as before --
  1248 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1249 normalization.
  1250 
  1251 * Generalized Isar history, with support for linear undo, direct state
  1252 addressing etc.
  1253 
  1254 * Changed defaults for unify configuration options:
  1255 
  1256   unify_trace_bound = 50 (formerly 25)
  1257   unify_search_bound = 60 (formerly 30)
  1258 
  1259 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1260 
  1261   a) On theory merge, the last set of code equations for a particular
  1262      constant is taken (in accordance with the policy applied by other
  1263      parts of the code generator framework).
  1264 
  1265   b) Code equations stemming from explicit declarations (e.g. code
  1266      attribute) gain priority over default code equations stemming
  1267      from definition, primrec, fun etc.
  1268 
  1269 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1270 
  1271 * Unified theorem tables for both code generators.  Thus [code
  1272 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1273 
  1274 * Command 'find_consts' searches for constants based on type and name
  1275 patterns, e.g.
  1276 
  1277     find_consts "_ => bool"
  1278 
  1279 By default, matching is against subtypes, but it may be restricted to
  1280 the whole type.  Searching by name is possible.  Multiple queries are
  1281 conjunctive and queries may be negated by prefixing them with a
  1282 hyphen:
  1283 
  1284     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1285 
  1286 * New 'find_theorems' criterion "solves" matches theorems that
  1287 directly solve the current goal (modulo higher-order unification).
  1288 
  1289 * Auto solve feature for main theorem statements: whenever a new goal
  1290 is stated, "find_theorems solves" is called; any theorems that could
  1291 solve the lemma directly are listed as part of the goal state.
  1292 Cf. associated options in Proof General Isabelle settings menu,
  1293 enabled by default, with reasonable timeout for pathological cases of
  1294 higher-order unification.
  1295 
  1296 
  1297 *** Document preparation ***
  1298 
  1299 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1300 demanding keyword 'by' and supporting the full method expression
  1301 syntax just like the Isar command 'by'.
  1302 
  1303 
  1304 *** HOL ***
  1305 
  1306 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1307 points Main and Complex_Main remain as before.
  1308 
  1309 * Logic image HOL-Plain provides a minimal HOL with the most important
  1310 tools available (inductive, datatype, primrec, ...).  This facilitates
  1311 experimentation and tool development.  Note that user applications
  1312 (and library theories) should never refer to anything below theory
  1313 Main, as before.
  1314 
  1315 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1316 experimentation due to shorter build times.
  1317 
  1318 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1319 were previously part of former HOL-Complex.  Entry point Hyperreal
  1320 remains valid, but theories formerly using Complex_Main should now use
  1321 new entry point Hypercomplex.
  1322 
  1323 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1324 Posix processes.  Avoids potentially expensive forking of the ML
  1325 process.  New thread-based implementation also works on non-Unix
  1326 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1327 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1328 commands are covered in the isar-ref manual.
  1329 
  1330 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1331 sledgehammer without local ATP installation (Vampire etc.). Other
  1332 provers may be included via suitable ML wrappers, see also
  1333 src/HOL/ATP_Linkup.thy.
  1334 
  1335 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1336 menu.
  1337 
  1338 * The metis method no longer fails because the theorem is too trivial
  1339 (contains the empty clause).
  1340 
  1341 * The metis method now fails in the usual manner, rather than raising
  1342 an exception, if it determines that it cannot prove the theorem.
  1343 
  1344 * Method "coherent" implements a prover for coherent logic (see also
  1345 src/Tools/coherent.ML).
  1346 
  1347 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1348 "undefined" is the right choice to replace "arbitrary", though
  1349 logically there is no difference.  INCOMPATIBILITY.
  1350 
  1351 * Command "value" now integrates different evaluation mechanisms.  The
  1352 result of the first successful evaluation mechanism is printed.  In
  1353 square brackets a particular named evaluation mechanisms may be
  1354 specified (currently, [SML], [code] or [nbe]).  See further
  1355 src/HOL/ex/Eval_Examples.thy.
  1356 
  1357 * Normalization by evaluation now allows non-leftlinear equations.
  1358 Declare with attribute [code nbe].
  1359 
  1360 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1361 as the structured Isar versions "cases" and "induct", cf. the
  1362 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1363 are now presented as a list of individual projections
  1364 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1365 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1366 rare situations a different rule is selected --- notably nested tuple
  1367 elimination instead of former prod.exhaust: use explicit (case_tac t
  1368 rule: prod.exhaust) here.
  1369 
  1370 * Attributes "cases", "induct", "coinduct" support "del" option.
  1371 
  1372 * Removed fact "case_split_thm", which duplicates "case_split".
  1373 
  1374 * The option datatype has been moved to a new theory Option.  Renamed
  1375 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1376 
  1377 * New predicate "strict_mono" classifies strict functions on partial
  1378 orders.  With strict functions on linear orders, reasoning about
  1379 (in)equalities is facilitated by theorems "strict_mono_eq",
  1380 "strict_mono_less_eq" and "strict_mono_less".
  1381 
  1382 * Some set operations are now proper qualified constants with
  1383 authentic syntax.  INCOMPATIBILITY:
  1384 
  1385     op Int ~>   Set.Int
  1386     op Un ~>    Set.Un
  1387     INTER ~>    Set.INTER
  1388     UNION ~>    Set.UNION
  1389     Inter ~>    Set.Inter
  1390     Union ~>    Set.Union
  1391     {} ~>       Set.empty
  1392     UNIV ~>     Set.UNIV
  1393 
  1394 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1395 theory Set.
  1396 
  1397 * Auxiliary class "itself" has disappeared -- classes without any
  1398 parameter are treated as expected by the 'class' command.
  1399 
  1400 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1401 
  1402 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1403 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1404 
  1405 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1406 method "approximation".  It proves formulas on real values by using
  1407 interval arithmetic.  In the formulas are also the transcendental
  1408 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1409 allowed. For examples see
  1410 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1411 
  1412 * Theory "Reflection" now resides in HOL/Library.
  1413 
  1414 * Entry point to Word library now simply named "Word".
  1415 INCOMPATIBILITY.
  1416 
  1417 * Made source layout more coherent with logical distribution
  1418 structure:
  1419 
  1420     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1421     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1422     src/HOL/Library/GCD.thy ~> src/HOL/
  1423     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1424     src/HOL/Library/Parity.thy ~> src/HOL/
  1425     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1426     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1427     src/HOL/Real/Lubs.thy ~> src/HOL/
  1428     src/HOL/Real/PReal.thy ~> src/HOL/
  1429     src/HOL/Real/Rational.thy ~> src/HOL/
  1430     src/HOL/Real/RComplete.thy ~> src/HOL/
  1431     src/HOL/Real/RealDef.thy ~> src/HOL/
  1432     src/HOL/Real/RealPow.thy ~> src/HOL/
  1433     src/HOL/Real/Real.thy ~> src/HOL/
  1434     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1435     src/HOL/Complex/Complex.thy ~> src/HOL/
  1436     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1437     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1438     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1439     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1440     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1441     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1442     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1443     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1444     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1445     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1446     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1447     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1448     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1449     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1450     src/HOL/Real/Float ~> src/HOL/Library/
  1451     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1452     src/HOL/Real/RealVector.thy ~> src/HOL/
  1453 
  1454     src/HOL/arith_data.ML ~> src/HOL/Tools
  1455     src/HOL/hologic.ML ~> src/HOL/Tools
  1456     src/HOL/simpdata.ML ~> src/HOL/Tools
  1457     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1458     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1459     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1460     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1461     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1462     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1463     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1464 
  1465     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1466     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1467     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1468     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1469     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1470     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1471 
  1472 * If methods "eval" and "evaluation" encounter a structured proof
  1473 state with !!/==>, only the conclusion is evaluated to True (if
  1474 possible), avoiding strange error messages.
  1475 
  1476 * Method "sizechange" automates termination proofs using (a
  1477 modification of) the size-change principle.  Requires SAT solver.  See
  1478 src/HOL/ex/Termination.thy for examples.
  1479 
  1480 * Simplifier: simproc for let expressions now unfolds if bound
  1481 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1482 
  1483 * Method "arith": Linear arithmetic now ignores all inequalities when
  1484 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1485 
  1486 * New attribute "arith" for facts that should always be used
  1487 automatically by arithmetic. It is intended to be used locally in
  1488 proofs, e.g.
  1489 
  1490   assumes [arith]: "x > 0"
  1491 
  1492 Global usage is discouraged because of possible performance impact.
  1493 
  1494 * New classes "top" and "bot" with corresponding operations "top" and
  1495 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1496 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1497 
  1498 * Changed definition lemma "less_fun_def" in order to provide an
  1499 instance for preorders on functions; use lemma "less_le" instead.
  1500 INCOMPATIBILITY.
  1501 
  1502 * Theory Orderings: class "wellorder" moved here, with explicit
  1503 induction rule "less_induct" as assumption.  For instantiation of
  1504 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1505 INCOMPATIBILITY.
  1506 
  1507 * Theory Orderings: added class "preorder" as superclass of "order".
  1508 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1509 etc. slightly changed.  Some theorems named order_class.* now named
  1510 preorder_class.*.
  1511 
  1512 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1513 "diag" to "Id_on".
  1514 
  1515 * Theory Finite_Set: added a new fold combinator of type
  1516 
  1517   ('a => 'b => 'b) => 'b => 'a set => 'b
  1518 
  1519 Occasionally this is more convenient than the old fold combinator
  1520 which is now defined in terms of the new one and renamed to
  1521 fold_image.
  1522 
  1523 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1524 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1525 extended with further lemmas!).  At the moment both still exist but
  1526 the former will disappear at some point.
  1527 
  1528 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1529 class recpower.  Type-specific simp rules for various recpower types
  1530 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1531 
  1532 rat_power_0    -> power_0
  1533 rat_power_Suc  -> power_Suc
  1534 realpow_0      -> power_0
  1535 realpow_Suc    -> power_Suc
  1536 complexpow_0   -> power_0
  1537 complexpow_Suc -> power_Suc
  1538 power_poly_0   -> power_0
  1539 power_poly_Suc -> power_Suc
  1540 
  1541 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1542 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1543 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1544 of lemmas from Divides has been generalized from nat to class
  1545 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1546 renames resulting from duplicate elimination:
  1547 
  1548     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1549     zero_dvd_iff ~>         dvd_0_left_iff
  1550     dvd_0 ~>                dvd_0_right
  1551     DIVISION_BY_ZERO_DIV ~> div_by_0
  1552     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1553     mult_div ~>             div_mult_self2_is_id
  1554     mult_mod ~>             mod_mult_self2_is_0
  1555 
  1556 * Theory IntDiv: removed many lemmas that are instances of class-based
  1557 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1558 rename old lemmas as follows:
  1559 
  1560 dvd_diff               -> nat_dvd_diff
  1561 dvd_zminus_iff         -> dvd_minus_iff
  1562 mod_add1_eq            -> mod_add_eq
  1563 mod_mult1_eq           -> mod_mult_right_eq
  1564 mod_mult1_eq'          -> mod_mult_left_eq
  1565 mod_mult_distrib_mod   -> mod_mult_eq
  1566 nat_mod_add_left_eq    -> mod_add_left_eq
  1567 nat_mod_add_right_eq   -> mod_add_right_eq
  1568 nat_mod_div_trivial    -> mod_div_trivial
  1569 nat_mod_mod_trivial    -> mod_mod_trivial
  1570 zdiv_zadd_self1        -> div_add_self1
  1571 zdiv_zadd_self2        -> div_add_self2
  1572 zdiv_zmult_self1       -> div_mult_self2_is_id
  1573 zdiv_zmult_self2       -> div_mult_self1_is_id
  1574 zdvd_triv_left         -> dvd_triv_left
  1575 zdvd_triv_right        -> dvd_triv_right
  1576 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1577 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1578 zmod_zadd_left_eq      -> mod_add_left_eq
  1579 zmod_zadd_right_eq     -> mod_add_right_eq
  1580 zmod_zadd_self1        -> mod_add_self1
  1581 zmod_zadd_self2        -> mod_add_self2
  1582 zmod_zadd1_eq          -> mod_add_eq
  1583 zmod_zdiff1_eq         -> mod_diff_eq
  1584 zmod_zdvd_zmod         -> mod_mod_cancel
  1585 zmod_zmod_cancel       -> mod_mod_cancel
  1586 zmod_zmult_self1       -> mod_mult_self2_is_0
  1587 zmod_zmult_self2       -> mod_mult_self1_is_0
  1588 zmod_1                 -> mod_by_1
  1589 zdiv_1                 -> div_by_1
  1590 zdvd_abs1              -> abs_dvd_iff
  1591 zdvd_abs2              -> dvd_abs_iff
  1592 zdvd_refl              -> dvd_refl
  1593 zdvd_trans             -> dvd_trans
  1594 zdvd_zadd              -> dvd_add
  1595 zdvd_zdiff             -> dvd_diff
  1596 zdvd_zminus_iff        -> dvd_minus_iff
  1597 zdvd_zminus2_iff       -> minus_dvd_iff
  1598 zdvd_zmultD            -> dvd_mult_right
  1599 zdvd_zmultD2           -> dvd_mult_left
  1600 zdvd_zmult_mono        -> mult_dvd_mono
  1601 zdvd_0_right           -> dvd_0_right
  1602 zdvd_0_left            -> dvd_0_left_iff
  1603 zdvd_1_left            -> one_dvd
  1604 zminus_dvd_iff         -> minus_dvd_iff
  1605 
  1606 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1607 
  1608 * The real numbers offer decimal input syntax: 12.34 is translated
  1609 into 1234/10^2. This translation is not reversed upon output.
  1610 
  1611 * Theory Library/Polynomial defines an abstract type 'a poly of
  1612 univariate polynomials with coefficients of type 'a.  In addition to
  1613 the standard ring operations, it also supports div and mod.  Code
  1614 generation is also supported, using list-style constructors.
  1615 
  1616 * Theory Library/Inner_Product defines a class of real_inner for real
  1617 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1618 => real.  Class real_inner is a subclass of real_normed_vector from
  1619 theory RealVector.
  1620 
  1621 * Theory Library/Product_Vector provides instances for the product
  1622 type 'a * 'b of several classes from RealVector and Inner_Product.
  1623 Definitions of addition, subtraction, scalar multiplication, norms,
  1624 and inner products are included.
  1625 
  1626 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1627 addition to the field operations, numerals and case syntax are also
  1628 supported.
  1629 
  1630 * Theory Library/Diagonalize provides constructive version of Cantor's
  1631 first diagonalization argument.
  1632 
  1633 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1634 zlcm (for int); carried together from various gcd/lcm developements in
  1635 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1636 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1637 may recover tupled syntax as follows:
  1638 
  1639     hide (open) const gcd
  1640     abbreviation gcd where
  1641       "gcd == (%(a, b). GCD.gcd a b)"
  1642     notation (output)
  1643       GCD.gcd ("gcd '(_, _')")
  1644 
  1645 The same works for lcm, zgcd, zlcm.
  1646 
  1647 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1648 instantiations for algebraic structures.  Removed some duplicate
  1649 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1650 
  1651 * ML antiquotation @{code} takes a constant as argument and generates
  1652 corresponding code in background and inserts name of the corresponding
  1653 resulting ML value/function/datatype constructor binding in place.
  1654 All occurrences of @{code} with a single ML block are generated
  1655 simultaneously.  Provides a generic and safe interface for
  1656 instrumentalizing code generation.  See
  1657 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1658 In future you ought to refrain from ad-hoc compiling generated SML
  1659 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1660 cannot refer to constants for which user-defined serializations are
  1661 set.  Refer to the corresponding ML counterpart directly in that
  1662 cases.
  1663 
  1664 * Command 'rep_datatype': instead of theorem names the command now
  1665 takes a list of terms denoting the constructors of the type to be
  1666 represented as datatype.  The characteristic theorems have to be
  1667 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1668 have disappeared in favour of existing ones:
  1669 
  1670     unit_induct                 ~> unit.induct
  1671     prod_induct                 ~> prod.induct
  1672     sum_induct                  ~> sum.induct
  1673     Suc_Suc_eq                  ~> nat.inject
  1674     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1675 
  1676 
  1677 *** HOL-Algebra ***
  1678 
  1679 * New locales for orders and lattices where the equivalence relation
  1680 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1681 locales use a record structure with field eq for the equivalence.
  1682 
  1683 * New theory of factorial domains.
  1684 
  1685 * Units_l_inv and Units_r_inv are now simp rules by default.
  1686 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1687 and/or r_inv will now also require deletion of these lemmas.
  1688 
  1689 * Renamed the following theorems, INCOMPATIBILITY:
  1690 
  1691 UpperD ~> Upper_memD
  1692 LowerD ~> Lower_memD
  1693 least_carrier ~> least_closed
  1694 greatest_carrier ~> greatest_closed
  1695 greatest_Lower_above ~> greatest_Lower_below
  1696 one_zero ~> carrier_one_zero
  1697 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1698 
  1699 
  1700 *** HOL-Nominal ***
  1701 
  1702 * Nominal datatypes can now contain type-variables.
  1703 
  1704 * Commands 'nominal_inductive' and 'equivariance' work with local
  1705 theory targets.
  1706 
  1707 * Nominal primrec can now works with local theory targets and its
  1708 specification syntax now conforms to the general format as seen in
  1709 'inductive' etc.
  1710 
  1711 * Method "perm_simp" honours the standard simplifier attributes
  1712 (no_asm), (no_asm_use) etc.
  1713 
  1714 * The new predicate #* is defined like freshness, except that on the
  1715 left hand side can be a set or list of atoms.
  1716 
  1717 * Experimental command 'nominal_inductive2' derives strong induction
  1718 principles for inductive definitions.  In contrast to
  1719 'nominal_inductive', which can only deal with a fixed number of
  1720 binders, it can deal with arbitrary expressions standing for sets of
  1721 atoms to be avoided.  The only inductive definition we have at the
  1722 moment that needs this generalisation is the typing rule for Lets in
  1723 the algorithm W:
  1724 
  1725  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1726  -----------------------------------------------------------------
  1727          Gamma |- Let x be t1 in t2 : T2
  1728 
  1729 In this rule one wants to avoid all the binders that are introduced by
  1730 "close Gamma T1".  We are looking for other examples where this
  1731 feature might be useful.  Please let us know.
  1732 
  1733 
  1734 *** HOLCF ***
  1735 
  1736 * Reimplemented the simplification procedure for proving continuity
  1737 subgoals.  The new simproc is extensible; users can declare additional
  1738 continuity introduction rules with the attribute [cont2cont].
  1739 
  1740 * The continuity simproc now uses a different introduction rule for
  1741 solving continuity subgoals on terms with lambda abstractions.  In
  1742 some rare cases the new simproc may fail to solve subgoals that the
  1743 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1744 Potential INCOMPATIBILITY.
  1745 
  1746 * Command 'fixrec': specification syntax now conforms to the general
  1747 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1748 examples.  INCOMPATIBILITY.
  1749 
  1750 
  1751 *** ZF ***
  1752 
  1753 * Proof of Zorn's Lemma for partial orders.
  1754 
  1755 
  1756 *** ML ***
  1757 
  1758 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1759 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1760 depends on multithreading, so timouts will not work before Poly/ML
  1761 5.2.1!
  1762 
  1763 * High-level support for concurrent ML programming, see
  1764 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1765 particularly convenient to organize independent functional
  1766 computations.  The concept of "synchronized variables" provides a
  1767 higher-order interface for components with shared state, avoiding the
  1768 delicate details of mutexes and condition variables.  (Requires
  1769 Poly/ML 5.2.1 or later.)
  1770 
  1771 * ML bindings produced via Isar commands are stored within the Isar
  1772 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1773 become thread-safe and work with undo as expected (concerning
  1774 top-level bindings, not side-effects on global references).
  1775 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1776 compiler at runtime; really global bindings need to be given outside a
  1777 theory.  (Requires Poly/ML 5.2 or later.)
  1778 
  1779 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1780 context.  Top-level ML bindings are stored within the proof context in
  1781 a purely sequential fashion, disregarding the nested proof structure.
  1782 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1783 proof.  (Requires Poly/ML 5.2 or later.)
  1784 
  1785 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1786 and Method.setup, as well as Isar commands 'attribute_setup' and
  1787 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1788 existing code accordingly, or use plain 'setup' together with old
  1789 Method.add_method.
  1790 
  1791 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1792 to 'a -> thm, while results are always tagged with an authentic oracle
  1793 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1794 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1795 accordingly.  Note that extra performance may be gained by producing
  1796 the cterm carefully, avoiding slow Thm.cterm_of.
  1797 
  1798 * Simplified interface for defining document antiquotations via
  1799 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1800 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1801 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1802 examples.
  1803 
  1804 * More systematic treatment of long names, abstract name bindings, and
  1805 name space operations.  Basic operations on qualified names have been
  1806 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1807 Long_Name.append.  Old type bstring has been mostly replaced by
  1808 abstract type binding (see structure Binding), which supports precise
  1809 qualification by packages and local theory targets, as well as proper
  1810 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1811 bstring values into Binding.name, or better pass through abstract
  1812 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1813 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1814 
  1815 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1816 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1817 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1818 
  1819 * Disposed old type and term read functions (Sign.read_def_typ,
  1820 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1821 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1822 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1823 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1824 resort for legacy applications.
  1825 
  1826 * Disposed old declarations, tactics, tactic combinators that refer to
  1827 the simpset or claset of an implicit theory (such as Addsimps,
  1828 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1829 embedded ML text, or local_simpset_of with a proper context passed as
  1830 explicit runtime argument.
  1831 
  1832 * Rules and tactics that read instantiations (read_instantiate,
  1833 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1834 context, which is required for parsing and type-checking.  Moreover,
  1835 the variables are specified as plain indexnames, not string encodings
  1836 thereof.  INCOMPATIBILITY.
  1837 
  1838 * Generic Toplevel.add_hook interface allows to analyze the result of
  1839 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1840 for theorem dependency output of transactions resulting in a new
  1841 theory state.
  1842 
  1843 * ML antiquotations: block-structured compilation context indicated by
  1844 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1845 
  1846   @{binding name}                         - basic name binding
  1847   @{let ?pat = term}                      - term abbreviation (HO matching)
  1848   @{note name = fact}                     - fact abbreviation
  1849   @{thm fact}                             - singleton fact (with attributes)
  1850   @{thms fact}                            - general fact (with attributes)
  1851   @{lemma prop by method}                 - singleton goal
  1852   @{lemma prop by meth1 meth2}            - singleton goal
  1853   @{lemma prop1 ... propN by method}      - general goal
  1854   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1855   @{lemma (open) ...}                     - open derivation
  1856 
  1857 
  1858 *** System ***
  1859 
  1860 * The Isabelle "emacs" tool provides a specific interface to invoke
  1861 Proof General / Emacs, with more explicit failure if that is not
  1862 installed (the old isabelle-interface script silently falls back on
  1863 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1864 installation location of the Proof General distribution.
  1865 
  1866 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1867 the Isabelle process into a JVM/Scala application.  See
  1868 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1869 process wrapper has been discontinued.)
  1870 
  1871 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1872 
  1873 * Various status messages (with exact source position information) are
  1874 emitted, if proper markup print mode is enabled.  This allows
  1875 user-interface components to provide detailed feedback on internal
  1876 prover operations.
  1877 
  1878 
  1879 
  1880 New in Isabelle2008 (June 2008)
  1881 -------------------------------
  1882 
  1883 *** General ***
  1884 
  1885 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1886 and updated, with formally checked references as hyperlinks.
  1887 
  1888 * Theory loader: use_thy (and similar operations) no longer set the
  1889 implicit ML context, which was occasionally hard to predict and in
  1890 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1891 provides a proper context already.
  1892 
  1893 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1894 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1895 'use' within a theory file will do the job.
  1896 
  1897 * Name space merge now observes canonical order, i.e. the second space
  1898 is inserted into the first one, while existing entries in the first
  1899 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1900 swap theory imports.
  1901 
  1902 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1903 INCOMPATIBILITY in identifier syntax etc.
  1904 
  1905 * Outer syntax: string tokens no longer admit escaped white space,
  1906 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1907 white space without escapes.
  1908 
  1909 * Outer syntax: string tokens may contain arbitrary character codes
  1910 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1911 "foo_bar".
  1912 
  1913 
  1914 *** Pure ***
  1915 
  1916 * Context-dependent token translations.  Default setup reverts locally
  1917 fixed variables, and adds hilite markup for undeclared frees.
  1918 
  1919 * Unused theorems can be found using the new command 'unused_thms'.
  1920 There are three ways of invoking it:
  1921 
  1922 (1) unused_thms
  1923      Only finds unused theorems in the current theory.
  1924 
  1925 (2) unused_thms thy_1 ... thy_n -
  1926      Finds unused theorems in the current theory and all of its ancestors,
  1927      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1928 
  1929 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1930      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1931      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1932      their ancestors.
  1933 
  1934 In order to increase the readability of the list produced by
  1935 unused_thms, theorems that have been created by a particular instance
  1936 of a theory command such as 'inductive' or 'function' are considered
  1937 to belong to the same "group", meaning that if at least one theorem in
  1938 this group is used, the other theorems in the same group are no longer
  1939 reported as unused.  Moreover, if all theorems in the group are
  1940 unused, only one theorem in the group is displayed.
  1941 
  1942 Note that proof objects have to be switched on in order for
  1943 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1944 usually the case when using Proof General with the default settings).
  1945 
  1946 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1947 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1948 duplicate fact bindings, or even accidental fact duplications.  Note
  1949 that tools may maintain dynamically scoped facts systematically, using
  1950 PureThy.add_thms_dynamic.
  1951 
  1952 * Command 'hide' now allows to hide from "fact" name space as well.
  1953 
  1954 * Eliminated destructive theorem database, simpset, claset, and
  1955 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1956 update of theories within ML code.
  1957 
  1958 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1959 INCOMPATIBILITY, object-logics depending on former Pure require
  1960 additional setup PureThy.old_appl_syntax_setup; object-logics
  1961 depending on former CPure need to refer to Pure.
  1962 
  1963 * Commands 'use' and 'ML' are now purely functional, operating on
  1964 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1965 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1966 INCOMPATIBILITY.
  1967 
  1968 * Command 'setup': discontinued implicit version with ML reference.
  1969 
  1970 * Instantiation target allows for simultaneous specification of class
  1971 instance operations together with an instantiation proof.
  1972 Type-checking phase allows to refer to class operations uniformly.
  1973 See src/HOL/Complex/Complex.thy for an Isar example and
  1974 src/HOL/Library/Eval.thy for an ML example.
  1975 
  1976 * Indexing of literal facts: be more serious about including only
  1977 facts from the visible specification/proof context, but not the
  1978 background context (locale etc.).  Affects `prop` notation and method
  1979 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1980 situations.
  1981 
  1982 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1983 "(open)" option, which used to expose internal bound variables to the
  1984 proof text.
  1985 
  1986 * Isar statements: removed obsolete case "rule_context".
  1987 INCOMPATIBILITY, better use explicit fixes/assumes.
  1988 
  1989 * Locale proofs: default proof step now includes 'unfold_locales';
  1990 hence 'proof' without argument may be used to unfold locale
  1991 predicates.
  1992 
  1993 
  1994 *** Document preparation ***
  1995 
  1996 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1997 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1998 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1999 spot); renamed link color from "darkblue" to "linkcolor" (default
  2000 value unchanged, can be redefined via \definecolor); no longer sets
  2001 "a4paper" option (unnecessary or even intrusive).
  2002 
  2003 * Antiquotation @{lemma A method} proves proposition A by the given
  2004 method (either a method name or a method name plus (optional) method
  2005 arguments in parentheses) and prints A just like @{prop A}.
  2006 
  2007 
  2008 *** HOL ***
  2009 
  2010 * New primrec package.  Specification syntax conforms in style to
  2011 definition/function/....  No separate induction rule is provided.  The
  2012 "primrec" command distinguishes old-style and new-style specifications
  2013 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2014 When adjusting theories, beware: constants stemming from new-style
  2015 primrec specifications have authentic syntax.
  2016 
  2017 * Metis prover is now an order of magnitude faster, and also works
  2018 with multithreading.
  2019 
  2020 * Metis: the maximum number of clauses that can be produced from a
  2021 theorem is now given by the attribute max_clauses.  Theorems that
  2022 exceed this number are ignored, with a warning printed.
  2023 
  2024 * Sledgehammer no longer produces structured proofs by default. To
  2025 enable, declare [[sledgehammer_full = true]].  Attributes
  2026 reconstruction_modulus, reconstruction_sorts renamed
  2027 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2028 
  2029 * Method "induct_scheme" derives user-specified induction rules
  2030 from well-founded induction and completeness of patterns. This factors
  2031 out some operations that are done internally by the function package
  2032 and makes them available separately.  See
  2033 src/HOL/ex/Induction_Scheme.thy for examples.
  2034 
  2035 * More flexible generation of measure functions for termination
  2036 proofs: Measure functions can be declared by proving a rule of the
  2037 form "is_measure f" and giving it the [measure_function] attribute.
  2038 The "is_measure" predicate is logically meaningless (always true), and
  2039 just guides the heuristic.  To find suitable measure functions, the
  2040 termination prover sets up the goal "is_measure ?f" of the appropriate
  2041 type and generates all solutions by prolog-style backwards proof using
  2042 the declared rules.
  2043 
  2044 This setup also deals with rules like 
  2045 
  2046   "is_measure f ==> is_measure (list_size f)"
  2047 
  2048 which accommodates nested datatypes that recurse through lists.
  2049 Similar rules are predeclared for products and option types.
  2050 
  2051 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2052 
  2053   INCOMPATIBILITIES:
  2054 
  2055   - Definitions of overloaded constants on sets have to be replaced by
  2056     definitions on => and bool.
  2057 
  2058   - Some definitions of overloaded operators on sets can now be proved
  2059     using the definitions of the operators on => and bool.  Therefore,
  2060     the following theorems have been renamed:
  2061 
  2062       subset_def   -> subset_eq
  2063       psubset_def  -> psubset_eq
  2064       set_diff_def -> set_diff_eq
  2065       Compl_def    -> Compl_eq
  2066       Sup_set_def  -> Sup_set_eq
  2067       Inf_set_def  -> Inf_set_eq
  2068       sup_set_def  -> sup_set_eq
  2069       inf_set_def  -> inf_set_eq
  2070 
  2071   - Due to the incompleteness of the HO unification algorithm, some
  2072     rules such as subst may require manual instantiation, if some of
  2073     the unknowns in the rule is a set.
  2074 
  2075   - Higher order unification and forward proofs:
  2076     The proof pattern
  2077 
  2078       have "P (S::'a set)" <...>
  2079       then have "EX S. P S" ..
  2080 
  2081     no longer works (due to the incompleteness of the HO unification
  2082     algorithm) and must be replaced by the pattern
  2083 
  2084       have "EX S. P S"
  2085       proof
  2086         show "P S" <...>
  2087       qed
  2088 
  2089   - Calculational reasoning with subst (or similar rules):
  2090     The proof pattern
  2091 
  2092       have "P (S::'a set)" <...>
  2093       also have "S = T" <...>
  2094       finally have "P T" .
  2095 
  2096     no longer works (for similar reasons as the previous example) and
  2097     must be replaced by something like
  2098 
  2099       have "P (S::'a set)" <...>
  2100       moreover have "S = T" <...>
  2101       ultimately have "P T" by simp
  2102 
  2103   - Tactics or packages written in ML code:
  2104     Code performing pattern matching on types via
  2105 
  2106       Type ("set", [T]) => ...
  2107 
  2108     must be rewritten. Moreover, functions like strip_type or
  2109     binder_types no longer return the right value when applied to a
  2110     type of the form
  2111 
  2112       T1 => ... => Tn => U => bool
  2113 
  2114     rather than
  2115 
  2116       T1 => ... => Tn => U set
  2117 
  2118 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2119 Wellfounded_Relations to theory Wellfounded.
  2120 
  2121 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2122 
  2123 * Class finite no longer treats UNIV as class parameter.  Use class
  2124 enum from theory Library/Enum instead to achieve a similar effect.
  2125 INCOMPATIBILITY.
  2126 
  2127 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2128 and "Cons".  INCOMPATIBILITY.
  2129 
  2130 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2131 Potential INCOMPATIBILITY.
  2132 
  2133 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2134 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2135 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2136 
  2137 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2138 the same name in theory Orderings:
  2139 
  2140   less_trans
  2141   less_linear
  2142   le_imp_less_or_eq
  2143   le_less_trans
  2144   less_le_trans
  2145   less_not_sym
  2146   less_asym
  2147 
  2148 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2149 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2150 and different variable names.
  2151 
  2152 * Library/Option_ord.thy: Canonical order on option type.
  2153 
  2154 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2155 finite maps.
  2156 
  2157 * Library/Countable.thy: Type class for countable types.
  2158 
  2159 * Theory Int: The representation of numerals has changed.  The infix
  2160 operator BIT and the bit datatype with constructors B0 and B1 have
  2161 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2162 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2163 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2164 accordingly.
  2165 
  2166 * Theory Nat: definition of <= and < on natural numbers no longer
  2167 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2168 le_def and less_def have disappeared.  Consider lemmas not_less
  2169 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2170 
  2171 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2172 (whose purpose mainly is for various fold_set functionals) have been
  2173 abandoned in favor of the existing algebraic classes
  2174 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2175 lower_semilattice (resp. upper_semilattice) and linorder.
  2176 INCOMPATIBILITY.
  2177 
  2178 * Theory Transitive_Closure: induct and cases rules now declare proper
  2179 case_names ("base" and "step").  INCOMPATIBILITY.
  2180 
  2181 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2182 lattices.  The form set-specific version is available as
  2183 Inductive.lfp_ordinal_induct_set.
  2184 
  2185 * Renamed theorems "power.simps" to "power_int.simps".
  2186 INCOMPATIBILITY.
  2187 
  2188 * Class semiring_div provides basic abstract properties of semirings
  2189 with division and modulo operations.  Subsumes former class dvd_mod.
  2190 
  2191 * Merged theories IntDef, Numeral and IntArith into unified theory
  2192 Int.  INCOMPATIBILITY.
  2193 
  2194 * Theory Library/Code_Index: type "index" now represents natural
  2195 numbers rather than integers.  INCOMPATIBILITY.
  2196 
  2197 * New class "uminus" with operation "uminus" (split of from class
  2198 "minus" which now only has operation "minus", binary).
  2199 INCOMPATIBILITY.
  2200 
  2201 * Constants "card", "internal_split", "option_map" now with authentic
  2202 syntax.  INCOMPATIBILITY.
  2203 
  2204 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2205 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2206 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2207 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2208 Sup_set_def, le_def, less_def, option_map_def now with object
  2209 equality.  INCOMPATIBILITY.
  2210 
  2211 * Records. Removed K_record, and replaced it by pure lambda term
  2212 %x. c. The simplifier setup is now more robust against eta expansion.
  2213 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2214 
  2215 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2216 
  2217 * Library/ListVector: new theory of arithmetic vector operations.
  2218 
  2219 * Library/Order_Relation: new theory of various orderings as sets of
  2220 pairs.  Defines preorders, partial orders, linear orders and
  2221 well-orders on sets and on types.
  2222 
  2223 
  2224 *** ZF ***
  2225 
  2226 * Renamed some theories to allow to loading both ZF and HOL in the
  2227 same session:
  2228 
  2229   Datatype  -> Datatype_ZF
  2230   Inductive -> Inductive_ZF
  2231   Int       -> Int_ZF
  2232   IntDiv    -> IntDiv_ZF
  2233   Nat       -> Nat_ZF
  2234   List      -> List_ZF
  2235   Main      -> Main_ZF
  2236 
  2237 INCOMPATIBILITY: ZF theories that import individual theories below
  2238 Main might need to be adapted.  Regular theory Main is still
  2239 available, as trivial extension of Main_ZF.
  2240 
  2241 
  2242 *** ML ***
  2243 
  2244 * ML within Isar: antiquotation @{const name} or @{const
  2245 name(typargs)} produces statically-checked Const term.
  2246 
  2247 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2248 (of the same name).  Removed obsolete print command.
  2249 
  2250 * Removed obsolete "use_legacy_bindings" function.
  2251 
  2252 * The ``print mode'' is now a thread-local value derived from a global
  2253 template (the former print_mode reference), thus access becomes
  2254 non-critical.  The global print_mode reference is for session
  2255 management only; user-code should use print_mode_value,
  2256 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2257 
  2258 * Functions system/system_out provide a robust way to invoke external
  2259 shell commands, with propagation of interrupts (requires Poly/ML
  2260 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2261 
  2262 
  2263 *** System ***
  2264 
  2265 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2266 in accordance with Proof General 3.7, which prefers GNU emacs.
  2267 
  2268 * isatool tty runs Isabelle process with plain tty interaction;
  2269 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2270 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2271 
  2272 * isatool browser now works with Cygwin as well, using general
  2273 "javapath" function defined in Isabelle process environment.
  2274 
  2275 * YXML notation provides a simple and efficient alternative to
  2276 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2277 isatool yxml as described in the Isabelle system manual.
  2278 
  2279 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2280 provides general wrapper for managing an Isabelle process in a robust
  2281 fashion, with ``cooked'' output from stdin/stderr.
  2282 
  2283 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2284 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2285 
  2286 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2287 way of changing the user's settings is via
  2288 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2289 script.
  2290 
  2291 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2292 cores of the underlying machine, which is a good starting point for
  2293 optimal performance tuning.  The corresponding usedir option -M allows
  2294 "max" as an alias for "0".  WARNING: does not work on certain versions
  2295 of Mac OS (with Poly/ML 5.1).
  2296 
  2297 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2298 adverse effect of Isabelle flooding interactive front-ends (notably
  2299 ProofGeneral / XEmacs).
  2300 
  2301 
  2302 
  2303 New in Isabelle2007 (November 2007)
  2304 -----------------------------------
  2305 
  2306 *** General ***
  2307 
  2308 * More uniform information about legacy features, notably a
  2309 warning/error of "Legacy feature: ...", depending on the state of the
  2310 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2311 legacy features will disappear eventually.
  2312 
  2313 * Theory syntax: the header format ``theory A = B + C:'' has been
  2314 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2315 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2316 
  2317 * Theory syntax: the old non-Isar theory file format has been
  2318 discontinued altogether.  Note that ML proof scripts may still be used
  2319 with Isar theories; migration is usually quite simple with the ML
  2320 function use_legacy_bindings.  INCOMPATIBILITY.
  2321 
  2322 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2323 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2324 quotes.
  2325 
  2326 * Theory loader: be more serious about observing the static theory
  2327 header specifications (including optional directories), but not the
  2328 accidental file locations of previously successful loads.  The strict
  2329 update policy of former update_thy is now already performed by
  2330 use_thy, so the former has been removed; use_thys updates several
  2331 theories simultaneously, just as 'imports' within a theory header
  2332 specification, but without merging the results.  Potential
  2333 INCOMPATIBILITY: may need to refine theory headers and commands
  2334 ROOT.ML which depend on load order.
  2335 
  2336 * Theory loader: optional support for content-based file
  2337 identification, instead of the traditional scheme of full physical
  2338 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2339 (cf. the system manual).  The new scheme allows to work with
  2340 non-finished theories in persistent session images, such that source
  2341 files may be moved later on without requiring reloads.
  2342 
  2343 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2344 file (with the same base name as the theory) are considered a legacy
  2345 feature, which will disappear eventually. Even now, the theory loader
  2346 no longer maintains dependencies on such files.
  2347 
  2348 * Syntax: the scope for resolving ambiguities via type-inference is
  2349 now limited to individual terms, instead of whole simultaneous
  2350 specifications as before. This greatly reduces the complexity of the
  2351 syntax module and improves flexibility by separating parsing and
  2352 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2353 'fixes' etc.) are required in rare situations.
  2354 
  2355 * Syntax: constants introduced by new-style packages ('definition',
  2356 'abbreviation' etc.) are passed through the syntax module in
  2357 ``authentic mode''. This means that associated mixfix annotations
  2358 really stick to such constants, independently of potential name space
  2359 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2360 trees are represented slightly differently, may need to adapt syntax
  2361 translations accordingly. Use CONST marker in 'translations' and
  2362 @{const_syntax} antiquotation in 'parse_translation' etc.
  2363 
  2364 * Legacy goal package: reduced interface to the bare minimum required
  2365 to keep existing proof scripts running.  Most other user-level
  2366 functions are now part of the OldGoals structure, which is *not* open
  2367 by default (consider isatool expandshort before open OldGoals).
  2368 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2369 these tend to cause confusion about the actual goal (!) context being
  2370 used here, which is not necessarily the same as the_context().
  2371 
  2372 * Command 'find_theorems': supports "*" wild-card in "name:"
  2373 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2374 support a specific search form (see ProofGeneral/CHANGES).
  2375 
  2376 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2377 by default, which means that "prems" (and also "fixed variables") are
  2378 suppressed from proof state output.  Note that the ProofGeneral
  2379 settings mechanism allows to change and save options persistently, but
  2380 older versions of Isabelle will fail to start up if a negative prems
  2381 limit is imposed.
  2382 
  2383 * Local theory targets may be specified by non-nested blocks of
  2384 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2385 contain definitions, theorems etc., including any derived mechanism
  2386 that has been implemented on top of these primitives.  This concept
  2387 generalizes the existing ``theorem (in ...)'' towards more versatility
  2388 and scalability.
  2389 
  2390 * Proof General interface: proper undo of final 'end' command;
  2391 discontinued Isabelle/classic mode (ML proof scripts).
  2392 
  2393 
  2394 *** Document preparation ***
  2395 
  2396 * Added antiquotation @{theory name} which prints the given name,
  2397 after checking that it refers to a valid ancestor theory in the
  2398 current context.
  2399 
  2400 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2401 check the given source text as ML type/structure, printing verbatim.
  2402 
  2403 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2404 "c args == rhs" given in the current context.  (Any number of
  2405 arguments may be given on the LHS.)
  2406 
  2407 
  2408 *** Pure ***
  2409 
  2410 * The 'class' package offers a combination of axclass and locale to
  2411 achieve Haskell-like type classes in Isabelle.  Definitions and
  2412 theorems within a class context produce both relative results (with
  2413 implicit parameters according to the locale context), and polymorphic
  2414 constants with qualified polymorphism (according to the class
  2415 context).  Within the body context of a 'class' target, a separate
  2416 syntax layer ("user space type system") takes care of converting
  2417 between global polymorphic consts and internal locale representation.
  2418 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2419 "isatool doc classes" provides a tutorial.
  2420 
  2421 * Generic code generator framework allows to generate executable
  2422 code for ML and Haskell (including Isabelle classes).  A short usage
  2423 sketch:
  2424 
  2425     internal compilation:
  2426         export_code <list of constants (term syntax)> in SML
  2427     writing SML code to a file:
  2428         export_code <list of constants (term syntax)> in SML <filename>
  2429     writing OCaml code to a file:
  2430         export_code <list of constants (term syntax)> in OCaml <filename>
  2431     writing Haskell code to a bunch of files:
  2432         export_code <list of constants (term syntax)> in Haskell <filename>
  2433 
  2434     evaluating closed propositions to True/False using code generation:
  2435         method ``eval''
  2436 
  2437 Reasonable default setup of framework in HOL.
  2438 
  2439 Theorem attributs for selecting and transforming function equations theorems:
  2440 
  2441     [code fun]:        select a theorem as function equation for a specific constant
  2442     [code fun del]:    deselect a theorem as function equation for a specific constant
  2443     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2444     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2445 
  2446 User-defined serializations (target in {SML, OCaml, Haskell}):
  2447 
  2448     code_const <and-list of constants (term syntax)>
  2449       {(target) <and-list of const target syntax>}+
  2450 
  2451     code_type <and-list of type constructors>
  2452       {(target) <and-list of type target syntax>}+
  2453 
  2454     code_instance <and-list of instances>
  2455       {(target)}+
  2456         where instance ::= <type constructor> :: <class>
  2457 
  2458     code_class <and_list of classes>
  2459       {(target) <and-list of class target syntax>}+
  2460         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2461 
  2462 code_instance and code_class only are effective to target Haskell.
  2463 
  2464 For example usage see src/HOL/ex/Codegenerator.thy and
  2465 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2466 generation from Isabelle/HOL theories is available via "isatool doc
  2467 codegen".
  2468 
  2469 * Code generator: consts in 'consts_code' Isar commands are now
  2470 referred to by usual term syntax (including optional type
  2471 annotations).
  2472 
  2473 * Command 'no_translations' removes translation rules from theory
  2474 syntax.
  2475 
  2476 * Overloaded definitions are now actually checked for acyclic
  2477 dependencies.  The overloading scheme is slightly more general than
  2478 that of Haskell98, although Isabelle does not demand an exact
  2479 correspondence to type class and instance declarations.
  2480 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2481 exotic versions of overloading -- at the discretion of the user!
  2482 
  2483 Polymorphic constants are represented via type arguments, i.e. the
  2484 instantiation that matches an instance against the most general
  2485 declaration given in the signature.  For example, with the declaration
  2486 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2487 as c(nat).  Overloading is essentially simultaneous structural
  2488 recursion over such type arguments.  Incomplete specification patterns
  2489 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2490 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2491 Command 'print_theory' outputs the normalized system of recursive
  2492 equations, see section "definitions".
  2493 
  2494 * Configuration options are maintained within the theory or proof
  2495 context (with name and type bool/int/string), providing a very simple
  2496 interface to a poor-man's version of general context data.  Tools may
  2497 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2498 these values using Config.get etc.  Users may change options via an
  2499 associated attribute of the same name.  This form of context
  2500 declaration works particularly well with commands 'declare' or
  2501 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2502 very easy to avoid global references, which would not observe Isar
  2503 toplevel undo/redo and fail to work with multithreading.
  2504 
  2505 Various global ML references of Pure and HOL have been turned into
  2506 configuration options:
  2507 
  2508   Unify.search_bound		unify_search_bound
  2509   Unify.trace_bound		unify_trace_bound
  2510   Unify.trace_simp		unify_trace_simp
  2511   Unify.trace_types		unify_trace_types
  2512   Simplifier.simp_depth_limit	simp_depth_limit
  2513   Blast.depth_limit		blast_depth_limit
  2514   DatatypeProp.dtK		datatype_distinctness_limit
  2515   fast_arith_neq_limit  	fast_arith_neq_limit
  2516   fast_arith_split_limit	fast_arith_split_limit
  2517 
  2518 * Named collections of theorems may be easily installed as context
  2519 data using the functor NamedThmsFun (see also
  2520 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2521 attributes; there is also a toplevel print command.  This facility is
  2522 just a common case of general context data, which is the preferred way
  2523 for anything more complex than just a list of facts in canonical
  2524 order.
  2525 
  2526 * Isar: command 'declaration' augments a local theory by generic
  2527 declaration functions written in ML.  This enables arbitrary content
  2528 being added to the context, depending on a morphism that tells the
  2529 difference of the original declaration context wrt. the application
  2530 context encountered later on.
  2531 
  2532 * Isar: proper interfaces for simplification procedures.  Command
  2533 'simproc_setup' declares named simprocs (with match patterns, and body
  2534 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2535 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2536 
  2537 * Isar: an extra pair of brackets around attribute declarations
  2538 abbreviates a theorem reference involving an internal dummy fact,
  2539 which will be ignored later --- only the effect of the attribute on
  2540 the background context will persist.  This form of in-place
  2541 declarations is particularly useful with commands like 'declare' and
  2542 'using', for example ``have A using [[simproc a]] by simp''.
  2543 
  2544 * Isar: method "assumption" (and implicit closing of subproofs) now
  2545 takes simple non-atomic goal assumptions into account: after applying
  2546 an assumption as a rule the resulting subgoals are solved by atomic
  2547 assumption steps.  This is particularly useful to finish 'obtain'
  2548 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2549 without referring to the original premise "!!x. P x ==> thesis" in the
  2550 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2551 more permissive.
  2552 
  2553 * Isar: implicit use of prems from the Isar proof context is
  2554 considered a legacy feature.  Common applications like ``have A .''
  2555 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2556 referencing facts explicitly here improves readability and
  2557 maintainability of proof texts.
  2558 
  2559 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2560 the obtained context from the course of reasoning!  For example:
  2561 
  2562   assume "EX x y. A x & B y"   -- "any previous fact"
  2563   then guess x and y by clarify
  2564 
  2565 This technique is potentially adventurous, depending on the facts and
  2566 proof tools being involved here.
  2567 
  2568 * Isar: known facts from the proof context may be specified as literal
  2569 propositions, using ASCII back-quote syntax.  This works wherever
  2570 named facts used to be allowed so far, in proof commands, proof
  2571 methods, attributes etc.  Literal facts are retrieved from the context
  2572 according to unification of type and term parameters.  For example,
  2573 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2574 theorems in the current context, then these are valid literal facts:
  2575 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2576 
  2577 There is also a proof method "fact" which does the same composition
  2578 for explicit goal states, e.g. the following proof texts coincide with
  2579 certain special cases of literal facts:
  2580 
  2581   have "A" by fact                 ==  note `A`
  2582   have "A ==> B" by fact           ==  note `A ==> B`
  2583   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2584   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2585 
  2586 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2587 outer syntax.  Thus symbolic identifiers may be used without
  2588 additional white space in declarations like this: ``assume *: A''.
  2589 
  2590 * Isar: 'print_facts' prints all local facts of the current context,
  2591 both named and unnamed ones.
  2592 
  2593 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2594 
  2595   def x == "t" and y == "u"
  2596 
  2597 * Isar: added command 'unfolding', which is structurally similar to
  2598 'using', but affects both the goal state and facts by unfolding given
  2599 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2600 'unfolded' attribute may be replaced by first-class proof text.
  2601 
  2602 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2603 and command 'unfolding' now all support object-level equalities
  2604 (potentially conditional).  The underlying notion of rewrite rule is
  2605 analogous to the 'rule_format' attribute, but *not* that of the
  2606 Simplifier (which is usually more generous).
  2607 
  2608 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2609 premises of a theorem by n. Useful in conjunction with drule.
  2610 
  2611 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2612 method expression within a sandbox consisting of the first N
  2613 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2614 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2615 simplifies all new goals that emerge from applying rule foo to the
  2616 originally first one.
  2617 
  2618 * Isar: schematic goals are no longer restricted to higher-order
  2619 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2620 expected.
  2621 
  2622 * Isar: the conclusion of a long theorem statement is now either
  2623 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2624 (essentially a disjunction of cases with local parameters and
  2625 assumptions).  The latter allows to express general elimination rules
  2626 adequately; in this notation common elimination rules look like this:
  2627 
  2628   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2629     assumes "EX x. P x"
  2630     obtains x where "P x"
  2631 
  2632   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2633     assumes "A & B"
  2634     obtains A and B
  2635 
  2636   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2637     assumes "A | B"
  2638     obtains
  2639       A
  2640     | B
  2641 
  2642 The subsequent classical rules even refer to the formal "thesis"
  2643 explicitly:
  2644 
  2645   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2646     obtains "~ thesis"
  2647 
  2648   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2649     obtains "thesis ==> something"
  2650 
  2651 The actual proof of an 'obtains' statement is analogous to that of the
  2652 Isar proof element 'obtain', only that there may be several cases.
  2653 Optional case names may be specified in parentheses; these will be
  2654 available both in the present proof and as annotations in the
  2655 resulting rule, for later use with the 'cases' method (cf. attribute
  2656 case_names).
  2657 
  2658 * Isar: the assumptions of a long theorem statement are available as
  2659 "assms" fact in the proof context.  This is more appropriate than the
  2660 (historical) "prems", which refers to all assumptions of the current
  2661 context, including those from the target locale, proof body etc.
  2662 
  2663 * Isar: 'print_statement' prints theorems from the current theory or
  2664 proof context in long statement form, according to the syntax of a
  2665 top-level lemma.
  2666 
  2667 * Isar: 'obtain' takes an optional case name for the local context
  2668 introduction rule (default "that").
  2669 
  2670 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2671 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2672 to occur.
  2673 
  2674 * Pure: syntax "CONST name" produces a fully internalized constant
  2675 according to the current context.  This is particularly useful for
  2676 syntax translations that should refer to internal constant
  2677 representations independently of name spaces.
  2678 
  2679 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2680 instead of "FOO ". This allows multiple binder declarations to coexist
  2681 in the same context.  INCOMPATIBILITY.
  2682 
  2683 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2684 primitive that also works in a locale context (both for constants and
  2685 fixed variables). Type declaration and internal syntactic representation
  2686 of given constants retrieved from the context. Likewise, the
  2687 'no_notation' command allows to remove given syntax annotations from the
  2688 current context.
  2689 
  2690 * Isar/locales: new derived specification elements 'axiomatization',
  2691 'definition', 'abbreviation', which support type-inference, admit
  2692 object-level specifications (equality, equivalence).  See also the
  2693 isar-ref manual.  Examples:
  2694 
  2695   axiomatization
  2696     eq  (infix "===" 50) where
  2697     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2698 
  2699   definition "f x y = x + y + 1"
  2700   definition g where "g x = f x x"
  2701 
  2702   abbreviation
  2703     neq  (infix "=!=" 50) where
  2704     "x =!= y == ~ (x === y)"
  2705 
  2706 These specifications may be also used in a locale context.  Then the
  2707 constants being introduced depend on certain fixed parameters, and the
  2708 constant name is qualified by the locale base name.  An internal
  2709 abbreviation takes care for convenient input and output, making the
  2710 parameters implicit and using the original short name.  See also
  2711 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2712 entities from a monomorphic theory.
  2713 
  2714 Presently, abbreviations are only available 'in' a target locale, but
  2715 not inherited by general import expressions.  Also note that
  2716 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2717 'translations' in common applications.  The "no_abbrevs" print mode
  2718 prevents folding of abbreviations in term output.
  2719 
  2720 Concrete syntax is attached to specified constants in internal form,
  2721 independently of name spaces.  The parse tree representation is
  2722 slightly different -- use 'notation' instead of raw 'syntax', and
  2723 'translations' with explicit "CONST" markup to accommodate this.
  2724 
  2725 * Pure/Isar: unified syntax for new-style specification mechanisms
  2726 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2727 full type inference and dummy patterns ("_").  For example:
  2728 
  2729   definition "K x _ = x"
  2730 
  2731   inductive conj for A B
  2732   where "A ==> B ==> conj A B"
  2733 
  2734 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2735 the current context.  Print mode "no_abbrevs" prevents inversion of
  2736 abbreviations on output.
  2737 
  2738 * Isar/locales: improved parameter handling: use of locales "var" and
  2739 "struct" no longer necessary; - parameter renamings are no longer
  2740 required to be injective.  For example, this allows to define
  2741 endomorphisms as locale endom = homom mult mult h.
  2742 
  2743 * Isar/locales: changed the way locales with predicates are defined.
  2744 Instead of accumulating the specification, the imported expression is
  2745 now an interpretation.  INCOMPATIBILITY: different normal form of
  2746 locale expressions.  In particular, in interpretations of locales with
  2747 predicates, goals repesenting already interpreted fragments are not
  2748 removed automatically.  Use methods `intro_locales' and
  2749 `unfold_locales'; see below.
  2750 
  2751 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2752 provide backward reasoning on locales predicates.  The methods are
  2753 aware of interpretations and discharge corresponding goals.
  2754 `intro_locales' is less aggressive then `unfold_locales' and does not
  2755 unfold predicates to assumptions.
  2756 
  2757 * Isar/locales: the order in which locale fragments are accumulated
  2758 has changed.  This enables to override declarations from fragments due
  2759 to interpretations -- for example, unwanted simp rules.
  2760 
  2761 * Isar/locales: interpretation in theories and proof contexts has been
  2762 extended.  One may now specify (and prove) equations, which are
  2763 unfolded in interpreted theorems.  This is useful for replacing
  2764 defined concepts (constants depending on locale parameters) by
  2765 concepts already existing in the target context.  Example:
  2766 
  2767   interpretation partial_order ["op <= :: [int, int] => bool"]
  2768     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2769 
  2770 Typically, the constant `partial_order.less' is created by a
  2771 definition specification element in the context of locale
  2772 partial_order.
  2773 
  2774 * Method "induct": improved internal context management to support
  2775 local fixes and defines on-the-fly. Thus explicit meta-level
  2776 connectives !!  and ==> are rarely required anymore in inductive goals
  2777 (using object-logic connectives for this purpose has been long
  2778 obsolete anyway). Common proof patterns are explained in
  2779 src/HOL/Induct/Common_Patterns.thy, see also
  2780 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2781 examples.
  2782 
  2783 * Method "induct": improved handling of simultaneous goals. Instead of
  2784 introducing object-level conjunction, the statement is now split into
  2785 several conclusions, while the corresponding symbolic cases are nested
  2786 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2787 see src/HOL/Induct/Common_Patterns.thy, for example.
  2788 
  2789 * Method "induct": mutual induction rules are now specified as a list
  2790 of rule sharing the same induction cases. HOL packages usually provide
  2791 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2792 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2793 mutual induction rules differently, i.e. like this:
  2794 
  2795   (induct rule: foo_bar.inducts)
  2796   (induct set: foo bar)
  2797   (induct pred: foo bar)
  2798   (induct type: foo bar)
  2799 
  2800 The ML function ProjectRule.projections turns old-style rules into the
  2801 new format.
  2802 
  2803 * Method "coinduct": dual of induction, see
  2804 src/HOL/Library/Coinductive_List.thy for various examples.
  2805 
  2806 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2807 considered a legacy feature.
  2808 
  2809 * Attribute "symmetric" produces result with standardized schematic
  2810 variables (index 0).  Potential INCOMPATIBILITY.
  2811 
  2812 * Simplifier: by default the simplifier trace only shows top level
  2813 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2814 default. Thus there is less danger of being flooded by the trace. The
  2815 trace indicates where parts have been suppressed.
  2816   
  2817 * Provers/classical: removed obsolete classical version of elim_format
  2818 attribute; classical elim/dest rules are now treated uniformly when
  2819 manipulating the claset.
  2820 
  2821 * Provers/classical: stricter checks to ensure that supplied intro,
  2822 dest and elim rules are well-formed; dest and elim rules must have at
  2823 least one premise.
  2824 
  2825 * Provers/classical: attributes dest/elim/intro take an optional
  2826 weight argument for the rule (just as the Pure versions).  Weights are
  2827 ignored by automated tools, but determine the search order of single
  2828 rule steps.
  2829 
  2830 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2831 where the body does not mention the bound variable.  Note that dummy
  2832 patterns implicitly depend on their context of bounds, which makes
  2833 "{_. _}" match any set comprehension as expected.  Potential
  2834 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2835 constant "_idtdummy" in the binding position.
  2836 
  2837 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2838 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2839 for example "A -> B" => "Pi A (%_. B)".
  2840 
  2841 * Pure: 'class_deps' command visualizes the subclass relation, using
  2842 the graph browser tool.
  2843 
  2844 * Pure: 'print_theory' now suppresses certain internal declarations by
  2845 default; use '!' option for full details.
  2846 
  2847 
  2848 *** HOL ***
  2849 
  2850 * Method "metis" proves goals by applying the Metis general-purpose
  2851 resolution prover (see also http://gilith.com/software/metis/).
  2852 Examples are in the directory MetisExamples.  WARNING: the
  2853 Isabelle/HOL-Metis integration does not yet work properly with
  2854 multi-threading.
  2855   
  2856 * Command 'sledgehammer' invokes external automatic theorem provers as
  2857 background processes.  It generates calls to the "metis" method if
  2858 successful. These can be pasted into the proof.  Users do not have to
  2859 wait for the automatic provers to return.  WARNING: does not really
  2860 work with multi-threading.
  2861 
  2862 * New "auto_quickcheck" feature tests outermost goal statements for
  2863 potential counter-examples.  Controlled by ML references
  2864 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2865 5000 milliseconds).  Fails silently if statements is outside of
  2866 executable fragment, or any other codgenerator problem occurs.
  2867 
  2868 * New constant "undefined" with axiom "undefined x = undefined".
  2869 
  2870 * Added class "HOL.eq", allowing for code generation with polymorphic
  2871 equality.
  2872 
  2873 * Some renaming of class constants due to canonical name prefixing in
  2874 the new 'class' package:
  2875 
  2876     HOL.abs ~> HOL.abs_class.abs
  2877     HOL.divide ~> HOL.divide_class.divide
  2878     0 ~> HOL.zero_class.zero
  2879     1 ~> HOL.one_class.one
  2880     op + ~> HOL.plus_class.plus
  2881     op - ~> HOL.minus_class.minus
  2882     uminus ~> HOL.minus_class.uminus
  2883     op * ~> HOL.times_class.times
  2884     op < ~> HOL.ord_class.less
  2885     op <= > HOL.ord_class.less_eq
  2886     Nat.power ~> Power.power_class.power
  2887     Nat.size ~> Nat.size_class.size
  2888     Numeral.number_of ~> Numeral.number_class.number_of
  2889     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2890     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2891     Orderings.min ~> Orderings.ord_class.min
  2892     Orderings.max ~> Orderings.ord_class.max
  2893     Divides.op div ~> Divides.div_class.div
  2894     Divides.op mod ~> Divides.div_class.mod
  2895     Divides.op dvd ~> Divides.div_class.dvd
  2896 
  2897 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2898 
  2899 a) User-defined constants using any of the names "plus", "minus",
  2900 "times", "less" or "less_eq". The standard syntax translations for
  2901 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2902 names.
  2903 
  2904 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2905 INCOMPATIBILITY: use more specific names.
  2906 
  2907 c) Permutative equations (e.g. "a + b = b + a")
  2908 Since the change of names also changes the order of terms, permutative
  2909 rewrite rules may get applied in a different order. Experience shows
  2910 that this is rarely the case (only two adaptions in the whole Isabelle
  2911 distribution).  INCOMPATIBILITY: rewrite proofs
  2912 
  2913 d) ML code directly refering to constant names
  2914 This in general only affects hand-written proof tactics, simprocs and
  2915 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2916 Consider using @{const_name} antiquotation.
  2917 
  2918 * New class "default" with associated constant "default".
  2919 
  2920 * Function "sgn" is now overloaded and available on int, real, complex
  2921 (and other numeric types), using class "sgn".  Two possible defs of
  2922 sgn are given as equational assumptions in the classes sgn_if and
  2923 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2924 INCOMPATIBILITY.
  2925 
  2926 * Locale "partial_order" now unified with class "order" (cf. theory
  2927 Orderings), added parameter "less".  INCOMPATIBILITY.
  2928 
  2929 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2930 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2931 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2932 
  2933 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2934 changed order of proof goals in instance proofs.
  2935 
  2936 * The transitivity reasoner for partial and linear orders is set up
  2937 for classes "order" and "linorder".  Instances of the reasoner are available
  2938 in all contexts importing or interpreting the corresponding locales.
  2939 Method "order" invokes the reasoner separately; the reasoner
  2940 is also integrated with the Simplifier as a solver.  Diagnostic
  2941 command 'print_orders' shows the available instances of the reasoner
  2942 in the current context.
  2943 
  2944 * Localized monotonicity predicate in theory "Orderings"; integrated
  2945 lemmas max_of_mono and min_of_mono with this predicate.
  2946 INCOMPATIBILITY.
  2947 
  2948 * Formulation of theorem "dense" changed slightly due to integration
  2949 with new class dense_linear_order.
  2950 
  2951 * Uniform lattice theory development in HOL.
  2952 
  2953     constants "meet" and "join" now named "inf" and "sup"
  2954     constant "Meet" now named "Inf"
  2955 
  2956     classes "meet_semilorder" and "join_semilorder" now named
  2957       "lower_semilattice" and "upper_semilattice"
  2958     class "lorder" now named "lattice"
  2959     class "comp_lat" now named "complete_lattice"
  2960 
  2961     Instantiation of lattice classes allows explicit definitions
  2962     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2963 
  2964   INCOMPATIBILITY.  Theorem renames:
  2965 
  2966     meet_left_le            ~> inf_le1
  2967     meet_right_le           ~> inf_le2
  2968     join_left_le            ~> sup_ge1
  2969     join_right_le           ~> sup_ge2
  2970     meet_join_le            ~> inf_sup_ord
  2971     le_meetI                ~> le_infI
  2972     join_leI                ~> le_supI
  2973     le_meet                 ~> le_inf_iff
  2974     le_join                 ~> ge_sup_conv
  2975     meet_idempotent         ~> inf_idem
  2976     join_idempotent         ~> sup_idem
  2977     meet_comm               ~> inf_commute
  2978     join_comm               ~> sup_commute
  2979     meet_leI1               ~> le_infI1
  2980     meet_leI2               ~> le_infI2
  2981     le_joinI1               ~> le_supI1
  2982     le_joinI2               ~> le_supI2
  2983     meet_assoc              ~> inf_assoc
  2984     join_assoc              ~> sup_assoc
  2985     meet_left_comm          ~> inf_left_commute
  2986     meet_left_idempotent    ~> inf_left_idem
  2987     join_left_comm          ~> sup_left_commute
  2988     join_left_idempotent    ~> sup_left_idem
  2989     meet_aci                ~> inf_aci
  2990     join_aci                ~> sup_aci
  2991     le_def_meet             ~> le_iff_inf
  2992     le_def_join             ~> le_iff_sup
  2993     join_absorp2            ~> sup_absorb2
  2994     join_absorp1            ~> sup_absorb1
  2995     meet_absorp1            ~> inf_absorb1
  2996     meet_absorp2            ~> inf_absorb2
  2997     meet_join_absorp        ~> inf_sup_absorb
  2998     join_meet_absorp        ~> sup_inf_absorb
  2999     distrib_join_le         ~> distrib_sup_le
  3000     distrib_meet_le         ~> distrib_inf_le
  3001 
  3002     add_meet_distrib_left   ~> add_inf_distrib_left
  3003     add_join_distrib_left   ~> add_sup_distrib_left
  3004     is_join_neg_meet        ~> is_join_neg_inf
  3005     is_meet_neg_join        ~> is_meet_neg_sup
  3006     add_meet_distrib_right  ~> add_inf_distrib_right
  3007     add_join_distrib_right  ~> add_sup_distrib_right
  3008     add_meet_join_distribs  ~> add_sup_inf_distribs
  3009     join_eq_neg_meet        ~> sup_eq_neg_inf
  3010     meet_eq_neg_join        ~> inf_eq_neg_sup
  3011     add_eq_meet_join        ~> add_eq_inf_sup
  3012     meet_0_imp_0            ~> inf_0_imp_0
  3013     join_0_imp_0            ~> sup_0_imp_0
  3014     meet_0_eq_0             ~> inf_0_eq_0
  3015     join_0_eq_0             ~> sup_0_eq_0
  3016     neg_meet_eq_join        ~> neg_inf_eq_sup
  3017     neg_join_eq_meet        ~> neg_sup_eq_inf
  3018     join_eq_if              ~> sup_eq_if
  3019 
  3020     mono_meet               ~> mono_inf
  3021     mono_join               ~> mono_sup
  3022     meet_bool_eq            ~> inf_bool_eq
  3023     join_bool_eq            ~> sup_bool_eq
  3024     meet_fun_eq             ~> inf_fun_eq
  3025     join_fun_eq             ~> sup_fun_eq
  3026     meet_set_eq             ~> inf_set_eq
  3027     join_set_eq             ~> sup_set_eq
  3028     meet1_iff               ~> inf1_iff
  3029     meet2_iff               ~> inf2_iff
  3030     meet1I                  ~> inf1I
  3031     meet2I                  ~> inf2I
  3032     meet1D1                 ~> inf1D1
  3033     meet2D1                 ~> inf2D1
  3034     meet1D2                 ~> inf1D2
  3035     meet2D2                 ~> inf2D2
  3036     meet1E                  ~> inf1E
  3037     meet2E                  ~> inf2E
  3038     join1_iff               ~> sup1_iff
  3039     join2_iff               ~> sup2_iff
  3040     join1I1                 ~> sup1I1
  3041     join2I1                 ~> sup2I1
  3042     join1I1                 ~> sup1I1
  3043     join2I2                 ~> sup1I2
  3044     join1CI                 ~> sup1CI
  3045     join2CI                 ~> sup2CI
  3046     join1E                  ~> sup1E
  3047     join2E                  ~> sup2E
  3048 
  3049     is_meet_Meet            ~> is_meet_Inf
  3050     Meet_bool_def           ~> Inf_bool_def
  3051     Meet_fun_def            ~> Inf_fun_def
  3052     Meet_greatest           ~> Inf_greatest
  3053     Meet_lower              ~> Inf_lower
  3054     Meet_set_def            ~> Inf_set_def
  3055 
  3056     Sup_def                 ~> Sup_Inf
  3057     Sup_bool_eq             ~> Sup_bool_def
  3058     Sup_fun_eq              ~> Sup_fun_def
  3059     Sup_set_eq              ~> Sup_set_def
  3060 
  3061     listsp_meetI            ~> listsp_infI
  3062     listsp_meet_eq          ~> listsp_inf_eq
  3063 
  3064     meet_min                ~> inf_min
  3065     join_max                ~> sup_max
  3066 
  3067 * Added syntactic class "size"; overloaded constant "size" now has
  3068 type "'a::size ==> bool"
  3069 
  3070 * Internal reorganisation of `size' of datatypes: size theorems
  3071 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3072 simplification rules by default!); theorems "prod.size" now named
  3073 "*.size".
  3074 
  3075 * Class "div" now inherits from class "times" rather than "type".
  3076 INCOMPATIBILITY.
  3077 
  3078 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3079 Linorder etc.  have disappeared; operations defined in terms of
  3080 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3081 
  3082 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3083 
  3084 * HOL-Word: New extensive library and type for generic, fixed size
  3085 machine words, with arithemtic, bit-wise, shifting and rotating
  3086 operations, reflection into int, nat, and bool lists, automation for
  3087 linear arithmetic (by automatic reflection into nat or int), including
  3088 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3089 arithmetic type classes, supporting automatic simplification of
  3090 numerals on all operations.
  3091 
  3092 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3093 
  3094 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3095 
  3096 * Code generator library theories:
  3097   - Code_Integer represents HOL integers by big integer literals in target
  3098     languages.
  3099   - Code_Char represents HOL characters by character literals in target
  3100     languages.
  3101   - Code_Char_chr like Code_Char, but also offers treatment of character
  3102     codes; includes Code_Integer.
  3103   - Executable_Set allows to generate code for finite sets using lists.
  3104   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3105     denominator).
  3106   - Executable_Real implements a subset of real numbers, namly those
  3107     representable by rational numbers.
  3108   - Efficient_Nat implements natural numbers by integers, which in general will
  3109     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3110     includes Code_Integer.
  3111   - Code_Index provides an additional datatype index which is mapped to
  3112     target-language built-in integers.
  3113   - Code_Message provides an additional datatype message_string which is isomorphic to
  3114     strings; messages are mapped to target-language strings.
  3115 
  3116 * New package for inductive predicates
  3117 
  3118   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3119 
  3120     inductive
  3121       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3122       for z_1 :: U_1 and ... and z_n :: U_m
  3123     where
  3124       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3125     | ...
  3126 
  3127   with full support for type-inference, rather than
  3128 
  3129     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3130 
  3131     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3132     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3133 
  3134     inductive "s z_1 ... z_m"
  3135     intros
  3136       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3137       ...
  3138 
  3139   For backward compatibility, there is a wrapper allowing inductive
  3140   sets to be defined with the new package via
  3141 
  3142     inductive_set
  3143       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3144       for z_1 :: U_1 and ... and z_n :: U_m
  3145     where
  3146       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3147     | ...
  3148 
  3149   or
  3150 
  3151     inductive_set
  3152       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3153       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3154       for z_1 :: U_1 and ... and z_n :: U_m
  3155     where
  3156       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3157     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3158     | ...
  3159 
  3160   if the additional syntax "p ..." is required.
  3161 
  3162   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3163   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3164 
  3165   INCOMPATIBILITIES:
  3166 
  3167   - Since declaration and definition of inductive sets or predicates
  3168     is no longer separated, abbreviations involving the newly
  3169     introduced sets or predicates must be specified together with the
  3170     introduction rules after the 'where' keyword (see above), rather
  3171     than before the actual inductive definition.
  3172 
  3173   - The variables in induction and elimination rules are now
  3174     quantified in the order of their occurrence in the introduction
  3175     rules, rather than in alphabetical order. Since this may break
  3176     some proofs, these proofs either have to be repaired, e.g. by
  3177     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3178     statements of the form
  3179 
  3180       case (rule_i a_i_1 ... a_i_{k_i})
  3181 
  3182     or the old order of quantification has to be restored by explicitly adding
  3183     meta-level quantifiers in the introduction rules, i.e.
  3184 
  3185       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3186 
  3187   - The format of the elimination rules is now
  3188 
  3189       p z_1 ... z_m x_1 ... x_n ==>
  3190         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3191         ==> ... ==> P
  3192 
  3193     for predicates and
  3194 
  3195       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3196         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3197         ==> ... ==> P
  3198 
  3199     for sets rather than
  3200 
  3201       x : s z_1 ... z_m ==>
  3202         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3203         ==> ... ==> P
  3204 
  3205     This may require terms in goals to be expanded to n-tuples
  3206     (e.g. using case_tac or simplification with the split_paired_all
  3207     rule) before the above elimination rule is applicable.
  3208 
  3209   - The elimination or case analysis rules for (mutually) inductive
  3210     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3211     list of rules "p_1_..._p_k.elims" is no longer available.
  3212 
  3213 * New package "function"/"fun" for general recursive functions,
  3214 supporting mutual and nested recursion, definitions in local contexts,
  3215 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3216 for small examples, and the separate tutorial on the function
  3217 package. The old recdef "package" is still available as before, but
  3218 users are encouraged to use the new package.
  3219 
  3220 * Method "lexicographic_order" automatically synthesizes termination
  3221 relations as lexicographic combinations of size measures. 
  3222 
  3223 * Case-expressions allow arbitrary constructor-patterns (including
  3224 "_") and take their order into account, like in functional
  3225 programming.  Internally, this is translated into nested
  3226 case-expressions; missing cases are added and mapped to the predefined
  3227 constant "undefined". In complicated cases printing may no longer show
  3228 the original input but the internal form. Lambda-abstractions allow
  3229 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3230 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3231 variable.
  3232 
  3233 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3234 is an abbreviation for "of_nat :: nat => int". The simplification
  3235 rules for "of_nat" have been changed to work like "int" did
  3236 previously.  Potential INCOMPATIBILITY:
  3237   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3238   - of_nat_diff and of_nat_mult are no longer default simp rules
  3239 
  3240 * Method "algebra" solves polynomial equations over (semi)rings using
  3241 Groebner bases. The (semi)ring structure is defined by locales and the
  3242 tool setup depends on that generic context. Installing the method for
  3243 a specific type involves instantiating the locale and possibly adding
  3244 declarations for computation on the coefficients.  The method is
  3245 already instantiated for natural numbers and for the axiomatic class
  3246 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3247 CALCULEMUS 2007 for the general principles underlying this
  3248 architecture of context-aware proof-tools.
  3249 
  3250 * Method "ferrack" implements quantifier elimination over
  3251 special-purpose dense linear orders using locales (analogous to
  3252 "algebra"). The method is already installed for class
  3253 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3254 rat, etc.
  3255 
  3256 * Former constant "List.op @" now named "List.append".  Use ML
  3257 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3258 circumvent possible incompatibilities when working on ML level.
  3259 
  3260 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3261 
  3262 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3263 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3264 
  3265 * New syntax for Haskell-like list comprehension (input only), eg.
  3266 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3267 
  3268 * The special syntax for function "filter" has changed from [x :
  3269 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3270 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3271 
  3272 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3273 defined on nat only, as an abbreviation for [a..<Suc b]
  3274 INCOMPATIBILITY.
  3275 
  3276 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3277 
  3278 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3279 
  3280 * New lemma collection field_simps (an extension of ring_simps) for
  3281 manipulating (in)equations involving division. Multiplies with all
  3282 denominators that can be proved to be non-zero (in equations) or
  3283 positive/negative (in inequations).
  3284 
  3285 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3286 have been improved and renamed to ring_simps, group_simps and
  3287 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3288 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3289 
  3290 * Theory Library/Commutative_Ring: switched from recdef to function
  3291 package; constants add, mul, pow now curried.  Infix syntax for
  3292 algebraic operations.
  3293 
  3294 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3295 INCOMPATIBILITY.
  3296 
  3297 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3298 INCOMPATIBILITY.
  3299 
  3300 * HOL/records: generalised field-update to take a function on the
  3301 field rather than the new value: r(|A := x|) is translated to A_update
  3302 (K x) r The K-combinator that is internally used is called K_record.
  3303 INCOMPATIBILITY: Usage of the plain update functions has to be
  3304 adapted.
  3305  
  3306 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3307 * x = 0, which are required for a semiring.  Richer structures do not
  3308 inherit from semiring_0 anymore, because this property is a theorem
  3309 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3310 there is more to prove, but this is mostly trivial.
  3311 
  3312 * Class "recpower" is generalized to arbitrary monoids, not just
  3313 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3314 commutativity or semiring properties additionally.
  3315 
  3316 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3317 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3318 better use 'abbreviation'.
  3319 
  3320 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3321 
  3322 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3323 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3324 significant changes for setting up numeral syntax for types:
  3325   - New constants Numeral.pred and Numeral.succ instead
  3326       of former Numeral.bin_pred and Numeral.bin_succ.
  3327   - Use integer operations instead of bin_add, bin_mult and so on.
  3328   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3329   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3330 
  3331 See src/HOL/Integ/IntArith.thy for an example setup.
  3332 
  3333 * Command 'normal_form' computes the normal form of a term that may
  3334 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3335 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3336 heavy-duty computations because the functions are compiled to ML
  3337 first.  Correspondingly, a method "normalization" is provided.  See
  3338 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3339 
  3340 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3341 25 like -->); output depends on the "iff" print_mode, the default is
  3342 "A = B" (with priority 50).
  3343 
  3344 * Relations less (<) and less_eq (<=) are also available on type bool.
  3345 Modified syntax to disallow nesting without explicit parentheses,
  3346 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3347 INCOMPATIBILITY.
  3348 
  3349 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3350 
  3351 * Relation composition operator "op O" now has precedence 75 and binds
  3352 stronger than union and intersection. INCOMPATIBILITY.
  3353 
  3354 * The old set interval syntax "{m..n(}" (and relatives) has been
  3355 removed.  Use "{m..<n}" (and relatives) instead.
  3356 
  3357 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3358 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3359 ``declare [[simproc del: neq]]''.
  3360 
  3361 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3362 True/False.
  3363 
  3364 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3365 
  3366 * Theorem setsum_mult renamed to setsum_right_distrib.
  3367 
  3368 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3369 ``rule'' method.
  3370 
  3371 * Reimplemented methods "sat" and "satx", with several improvements:
  3372 goals no longer need to be stated as "<prems> ==> False", equivalences
  3373 (i.e. "=" on type bool) are handled, variable names of the form
  3374 "lit_<n>" are no longer reserved, significant speedup.
  3375 
  3376 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3377 zChaff is still supported as well.
  3378 
  3379 * 'inductive' and 'datatype': provide projections of mutual rules,
  3380 bundled as foo_bar.inducts;
  3381 
  3382 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3383 Library.
  3384 
  3385 * Library: moved theory Accessible_Part to main HOL.
  3386 
  3387 * Library: added theory Coinductive_List of potentially infinite lists
  3388 as greatest fixed-point.
  3389 
  3390 * Library: added theory AssocList which implements (finite) maps as
  3391 association lists.
  3392 
  3393 * Method "evaluation" solves goals (i.e. a boolean expression)
  3394 efficiently by compiling it to ML.  The goal is "proved" (via an
  3395 oracle) if it evaluates to True.
  3396 
  3397 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3398 also when invoked by the simplifier.  This results in the Simplifier
  3399 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3400 Configuration option fast_arith_split_limit=0 recovers the old
  3401 behavior.
  3402 
  3403 * Support for hex (0x20) and binary (0b1001) numerals.
  3404 
  3405 * New method: reify eqs (t), where eqs are equations for an
  3406 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3407 parameter, computes a term s::'b and a list xs::'a list and proves the
  3408 theorem I xs s = t. This is also known as reification or quoting. The
  3409 resulting theorem is applied to the subgoal to substitute t with I xs
  3410 s.  If t is omitted, the subgoal itself is reified.
  3411 
  3412 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3413 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3414 where f is supposed to be a computable function (in the sense of code
  3415 generattion). The method uses reify to compute s and xs as above then
  3416 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3417 r and finally gets the theorem t = r, which is again applied to the
  3418 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3419 
  3420 * Reflection: Automatic reification now handels binding, an example is
  3421 available in src/HOL/ex/ReflectionEx.thy
  3422 
  3423 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3424 command 'statespace' that is similar to 'record', but introduces an
  3425 abstract specification based on the locale infrastructure instead of
  3426 HOL types.  This leads to extra flexibility in composing state spaces,
  3427 in particular multiple inheritance and renaming of components.
  3428 
  3429 
  3430 *** HOL-Complex ***
  3431 
  3432 * Hyperreal: Functions root and sqrt are now defined on negative real
  3433 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3434 Nonnegativity side conditions have been removed from many lemmas, so
  3435 that more subgoals may now be solved by simplification; potential
  3436 INCOMPATIBILITY.
  3437 
  3438 * Real: new type classes formalize real normed vector spaces and
  3439 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3440 and norm :: 'a => real.
  3441 
  3442 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3443 reals into other types. The overloaded constant Reals :: 'a set is now
  3444 defined as range of_real; potential INCOMPATIBILITY.
  3445 
  3446 * Real: proper support for ML code generation, including 'quickcheck'.
  3447 Reals are implemented as arbitrary precision rationals.
  3448 
  3449 * Hyperreal: Several constants that previously worked only for the
  3450 reals have been generalized, so they now work over arbitrary vector
  3451 spaces. Type annotations may need to be added in some cases; potential
  3452 INCOMPATIBILITY.
  3453 
  3454   Infinitesimal  :: ('a::real_normed_vector) star set
  3455   HFinite        :: ('a::real_normed_vector) star set
  3456   HInfinite      :: ('a::real_normed_vector) star set
  3457   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3458   monad          :: ('a::real_normed_vector) star => 'a star set
  3459   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3460   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3461   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3462   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3463   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3464   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3465   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3466   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3467   sgn            :: 'a::real_normed_vector => 'a
  3468   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3469 
  3470 * Complex: Some complex-specific constants are now abbreviations for
  3471 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3472 hnorm.  Other constants have been entirely removed in favor of the
  3473 polymorphic versions (INCOMPATIBILITY):
  3474 
  3475   approx        <-- capprox
  3476   HFinite       <-- CFinite
  3477   HInfinite     <-- CInfinite
  3478   Infinitesimal <-- CInfinitesimal
  3479   monad         <-- cmonad
  3480   galaxy        <-- cgalaxy
  3481   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3482   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3483   (ns)deriv     <-- (ns)cderiv
  3484 
  3485 
  3486 *** HOL-Algebra ***
  3487 
  3488 * Formalisation of ideals and the quotient construction over rings.
  3489 
  3490 * Order and lattice theory no longer based on records.
  3491 INCOMPATIBILITY.
  3492 
  3493 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3494 greatest_closed.  INCOMPATIBILITY.
  3495 
  3496 * Method algebra is now set up via an attribute.  For examples see
  3497 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3498 of algebraic structures.
  3499 
  3500 * Renamed theory CRing to Ring.
  3501 
  3502 
  3503 *** HOL-Nominal ***
  3504 
  3505 * Substantial, yet incomplete support for nominal datatypes (binding
  3506 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3507 src/HOL/Nominal/Examples.  Prospective users should consult
  3508 http://isabelle.in.tum.de/nominal/
  3509 
  3510 
  3511 *** ML ***
  3512 
  3513 * ML basics: just one true type int, which coincides with IntInf.int
  3514 (even on SML/NJ).
  3515 
  3516 * ML within Isar: antiquotations allow to embed statically-checked
  3517 formal entities in the source, referring to the context available at
  3518 compile-time.  For example:
  3519 
  3520 ML {* @{sort "{zero,one}"} *}
  3521 ML {* @{typ "'a => 'b"} *}
  3522 ML {* @{term "%x. x"} *}
  3523 ML {* @{prop "x == y"} *}
  3524 ML {* @{ctyp "'a => 'b"} *}
  3525 ML {* @{cterm "%x. x"} *}
  3526 ML {* @{cprop "x == y"} *}
  3527 ML {* @{thm asm_rl} *}
  3528 ML {* @{thms asm_rl} *}
  3529 ML {* @{type_name c} *}
  3530 ML {* @{type_syntax c} *}
  3531 ML {* @{const_name c} *}
  3532 ML {* @{const_syntax c} *}
  3533 ML {* @{context} *}
  3534 ML {* @{theory} *}
  3535 ML {* @{theory Pure} *}
  3536 ML {* @{theory_ref} *}
  3537 ML {* @{theory_ref Pure} *}
  3538 ML {* @{simpset} *}
  3539 ML {* @{claset} *}
  3540 ML {* @{clasimpset} *}
  3541 
  3542 The same works for sources being ``used'' within an Isar context.
  3543 
  3544 * ML in Isar: improved error reporting; extra verbosity with
  3545 ML_Context.trace enabled.
  3546 
  3547 * Pure/General/table.ML: the join operations now works via exceptions
  3548 DUP/SAME instead of type option. This is simpler in simple cases, and
  3549 admits slightly more efficient complex applications.
  3550 
  3551 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3552 use Context.generic instead of just theory.
  3553 
  3554 * Pure: datatype Context.generic joins theory/Proof.context and
  3555 provides some facilities for code that works in either kind of
  3556 context, notably GenericDataFun for uniform theory and proof data.
  3557 
  3558 * Pure: simplified internal attribute type, which is now always
  3559 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3560 local (Proof.context) attributes have been discontinued, while
  3561 minimizing code duplication. Thm.rule_attribute and
  3562 Thm.declaration_attribute build canonical attributes; see also structure
  3563 Context for further operations on Context.generic, notably
  3564 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3565 declarations and definitions.
  3566 
  3567 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3568 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3569 init only required for impure data. INCOMPATIBILITY: empty really need
  3570 to be empty (no dependencies on theory content!)
  3571 
  3572 * Pure/kernel: consts certification ignores sort constraints given in
  3573 signature declarations. (This information is not relevant to the
  3574 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3575 potential INCOMPATIBILITY.
  3576 
  3577 * Pure: axiomatic type classes are now purely definitional, with
  3578 explicit proofs of class axioms and super class relations performed
  3579 internally. See Pure/axclass.ML for the main internal interfaces --
  3580 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3581 AxClass.axiomatize_class/classrel/arity supersede
  3582 Sign.add_classes/classrel/arities.
  3583 
  3584 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3585 global/local versions on theory vs. Proof.context have been
  3586 discontinued; Attrib.syntax and Method.syntax have been adapted
  3587 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3588 attributes, methods, etc.
  3589 
  3590 * Pure: several functions of signature "... -> theory -> theory * ..."
  3591 have been reoriented to "... -> theory -> ... * theory" in order to
  3592 allow natural usage in combination with the ||>, ||>>, |-> and
  3593 fold_map combinators.
  3594 
  3595 * Pure: official theorem names (closed derivations) and additional
  3596 comments (tags) are now strictly separate.  Name hints -- which are
  3597 maintained as tags -- may be attached any time without affecting the
  3598 derivation.
  3599 
  3600 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3601 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3602 achieve the old behaviour.
  3603 
  3604 * Pure: the "Goal" constant is now called "prop", supporting a
  3605 slightly more general idea of ``protecting'' meta-level rule
  3606 statements.
  3607 
  3608 * Pure: Logic.(un)varify only works in a global context, which is now
  3609 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3610 Logic.legacy_(un)varify as temporary workaround.
  3611 
  3612 * Pure: structure Name provides scalable operations for generating
  3613 internal variable names, notably Name.variants etc.  This replaces
  3614 some popular functions from term.ML:
  3615 
  3616   Term.variant		->  Name.variant
  3617   Term.variantlist	->  Name.variant_list
  3618   Term.invent_names	->  Name.invent_list
  3619 
  3620 Note that low-level renaming rarely occurs in new code -- operations
  3621 from structure Variable are used instead (see below).
  3622 
  3623 * Pure: structure Variable provides fundamental operations for proper
  3624 treatment of fixed/schematic variables in a context.  For example,
  3625 Variable.import introduces fixes for schematics of given facts and
  3626 Variable.export reverses the effect (up to renaming) -- this replaces
  3627 various freeze_thaw operations.
  3628 
  3629 * Pure: structure Goal provides simple interfaces for
  3630 init/conclude/finish and tactical prove operations (replacing former
  3631 Tactic.prove).  Goal.prove is the canonical way to prove results
  3632 within a given context; Goal.prove_global is a degraded version for
  3633 theory level goals, including a global Drule.standard.  Note that
  3634 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3635 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3636 in a locale context).
  3637 
  3638 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3639 and type checking (Syntax.check_term etc.), with common combinations
  3640 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3641 which are considered legacy and await removal.
  3642 
  3643 * Pure/Syntax: generic interfaces for type unchecking
  3644 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3645 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3646 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3647 available for convenience, but refer to the very same operations using
  3648 a mere theory instead of a full context.
  3649 
  3650 * Isar: simplified treatment of user-level errors, using exception
  3651 ERROR of string uniformly.  Function error now merely raises ERROR,
  3652 without any side effect on output channels.  The Isar toplevel takes
  3653 care of proper display of ERROR exceptions.  ML code may use plain
  3654 handle/can/try; cat_error may be used to concatenate errors like this:
  3655 
  3656   ... handle ERROR msg => cat_error msg "..."
  3657 
  3658 Toplevel ML code (run directly or through the Isar toplevel) may be
  3659 embedded into the Isar toplevel with exception display/debug like
  3660 this:
  3661 
  3662   Isar.toplevel (fn () => ...)
  3663 
  3664 INCOMPATIBILITY, removed special transform_error facilities, removed
  3665 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3666 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3667 -- use plain ERROR instead.
  3668 
  3669 * Isar: theory setup now has type (theory -> theory), instead of a
  3670 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3671 
  3672 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3673 ProofContext.debug/verbose flags.
  3674 
  3675 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3676 theory before entering a proof state.  Transactions now always see a
  3677 quasi-functional intermediate checkpoint, both in interactive and
  3678 batch mode.
  3679 
  3680 * Isar: simplified interfaces for outer syntax.  Renamed
  3681 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3682 OuterSyntax.add_parsers -- this functionality is now included in
  3683 OuterSyntax.command etc.  INCOMPATIBILITY.
  3684 
  3685 * Simplifier: the simpset of a running simplification process now
  3686 contains a proof context (cf. Simplifier.the_context), which is the
  3687 very context that the initial simpset has been retrieved from (by
  3688 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3689 (solver, looper etc.) may depend on arbitrary proof data.
  3690 
  3691 * Simplifier.inherit_context inherits the proof context (plus the
  3692 local bounds) of the current simplification process; any simproc
  3693 etc. that calls the Simplifier recursively should do this!  Removed
  3694 former Simplifier.inherit_bounds, which is already included here --
  3695 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3696 specify an explicit context using Simplifier.context/theory_context.
  3697 
  3698 * Simplifier/Classical Reasoner: more abstract interfaces
  3699 change_simpset/claset for modifying the simpset/claset reference of a
  3700 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3701 INCOMPATIBILITY.
  3702 
  3703 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3704 "Trueprop" etc.
  3705 
  3706 
  3707 *** System ***
  3708 
  3709 * settings: the default heap location within ISABELLE_HOME_USER now
  3710 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3711 Isabelle installations.
  3712 
  3713 * isabelle-process: option -S (secure mode) disables some critical
  3714 operations, notably runtime compilation and evaluation of ML source
  3715 code.
  3716 
  3717 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3718 
  3719 * Support for parallel execution, using native multicore support of
  3720 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3721 independent theories, according to the given theory header
  3722 specifications. The maximum number of worker threads is specified via
  3723 usedir option -M or the "max-threads" setting in Proof General. A
  3724 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3725 to 6 on a 8-core machine.  User-code needs to observe certain
  3726 guidelines for thread-safe programming, see appendix A in the Isar
  3727 Implementation manual.
  3728 
  3729 
  3730 
  3731 New in Isabelle2005 (October 2005)
  3732 ----------------------------------
  3733 
  3734 *** General ***
  3735 
  3736 * Theory headers: the new header syntax for Isar theories is
  3737 
  3738   theory <name>
  3739   imports <theory1> ... <theoryN>
  3740   uses <file1> ... <fileM>
  3741   begin
  3742 
  3743 where the 'uses' part is optional.  The previous syntax
  3744 
  3745   theory <name> = <theory1> + ... + <theoryN>:
  3746 
  3747 will disappear in the next release.  Use isatool fixheaders to convert
  3748 existing theory files.  Note that there is no change in ancient
  3749 non-Isar theories now, but these will disappear soon.
  3750 
  3751 * Theory loader: parent theories can now also be referred to via
  3752 relative and absolute paths.
  3753 
  3754 * Command 'find_theorems' searches for a list of criteria instead of a
  3755 list of constants. Known criteria are: intro, elim, dest, name:string,
  3756 simp:term, and any term. Criteria can be preceded by '-' to select
  3757 theorems that do not match. Intro, elim, dest select theorems that
  3758 match the current goal, name:s selects theorems whose fully qualified
  3759 name contain s, and simp:term selects all simplification rules whose
  3760 lhs match term.  Any other term is interpreted as pattern and selects
  3761 all theorems matching the pattern. Available in ProofGeneral under
  3762 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3763 
  3764   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3765 
  3766 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3767 matching the current goal as introduction rule and not having "HOL."
  3768 in their name (i.e. not being defined in theory HOL).
  3769 
  3770 * Command 'thms_containing' has been discontinued in favour of
  3771 'find_theorems'; INCOMPATIBILITY.
  3772 
  3773 * Communication with Proof General is now 8bit clean, which means that
  3774 Unicode text in UTF-8 encoding may be used within theory texts (both
  3775 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3776 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3777 
  3778   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3779   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3780 
  3781 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3782 Classical Reasoner.  Typical big applications run around 2 times
  3783 faster.
  3784 
  3785 
  3786 *** Document preparation ***
  3787 
  3788 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3789 of raw sources.  Only those symbols that do not require additional
  3790 LaTeX packages (depending on comments in isabellesym.sty) are
  3791 displayed properly, everything else is left verbatim.  isatool display
  3792 and isatool print are used as front ends (these are subject to the
  3793 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3794 
  3795 * Command tags control specific markup of certain regions of text,
  3796 notably folding and hiding.  Predefined tags include "theory" (for
  3797 theory begin and end), "proof" for proof commands, and "ML" for
  3798 commands involving ML code; the additional tags "visible" and
  3799 "invisible" are unused by default.  Users may give explicit tag
  3800 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3801 interpretation of tags is determined by the LaTeX job during document
  3802 preparation: see option -V of isatool usedir, or options -n and -t of
  3803 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3804 \isadroptag.
  3805 
  3806 Several document versions may be produced at the same time via isatool
  3807 usedir (the generated index.html will link all of them).  Typical
  3808 specifications include ''-V document=theory,proof,ML'' to present
  3809 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3810 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3811 these parts without any formal replacement text.  The Isabelle site
  3812 default settings produce ''document'' and ''outline'' versions as
  3813 specified above.
  3814 
  3815 * Several new antiquotations:
  3816 
  3817   @{term_type term} prints a term with its type annotated;
  3818 
  3819   @{typeof term} prints the type of a term;
  3820 
  3821   @{const const} is the same as @{term const}, but checks that the
  3822   argument is a known logical constant;
  3823 
  3824   @{term_style style term} and @{thm_style style thm} print a term or
  3825   theorem applying a "style" to it
  3826 
  3827   @{ML text}
  3828 
  3829 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3830 definitions, equations, inequations etc., 'concl' printing only the
  3831 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3832 to print the specified premise.  TermStyle.add_style provides an ML
  3833 interface for introducing further styles.  See also the "LaTeX Sugar"
  3834 document practical applications.  The ML antiquotation prints
  3835 type-checked ML expressions verbatim.
  3836 
  3837 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3838 and 'text' support optional locale specification '(in loc)', which
  3839 specifies the default context for interpreting antiquotations.  For
  3840 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3841 
  3842 * Option 'locale=NAME' of antiquotations specifies an alternative
  3843 context interpreting the subsequent argument.  For example: @{thm
  3844 [locale=lattice] inf_assoc}.
  3845 
  3846 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3847 a proof context.
  3848 
  3849 * Proper output of antiquotations for theory commands involving a
  3850 proof context (such as 'locale' or 'theorem (in loc) ...').
  3851 
  3852 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3853 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3854 
  3855 * isatool usedir: new option -C (default true) controls whether option
  3856 -D should include a copy of the original document directory; -C false
  3857 prevents unwanted effects such as copying of administrative CVS data.
  3858 
  3859 
  3860 *** Pure ***
  3861 
  3862 * Considerably improved version of 'constdefs' command.  Now performs
  3863 automatic type-inference of declared constants; additional support for
  3864 local structure declarations (cf. locales and HOL records), see also
  3865 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3866 sequential dependencies of definitions within a single 'constdefs'
  3867 section; moreover, the declared name needs to be an identifier.  If
  3868 all fails, consider to fall back on 'consts' and 'defs' separately.
  3869 
  3870 * Improved indexed syntax and implicit structures.  First of all,
  3871 indexed syntax provides a notational device for subscripted
  3872 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3873 expressions.  Secondly, in a local context with structure
  3874 declarations, number indexes \<^sub>n or the empty index (default
  3875 number 1) refer to a certain fixed variable implicitly; option
  3876 show_structs controls printing of implicit structures.  Typical
  3877 applications of these concepts involve record types and locales.
  3878 
  3879 * New command 'no_syntax' removes grammar declarations (and
  3880 translations) resulting from the given syntax specification, which is
  3881 interpreted in the same manner as for the 'syntax' command.
  3882 
  3883 * 'Advanced' translation functions (parse_translation etc.) may depend
  3884 on the signature of the theory context being presently used for
  3885 parsing/printing, see also isar-ref manual.
  3886 
  3887 * Improved 'oracle' command provides a type-safe interface to turn an
  3888 ML expression of type theory -> T -> term into a primitive rule of
  3889 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3890 is already included here); see also FOL/ex/IffExample.thy;
  3891 INCOMPATIBILITY.
  3892 
  3893 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3894 before); "cI" is no longer bound, use "c.intro" instead.
  3895 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3896 axclasses vs. locales.
  3897 
  3898 * Improved internal renaming of symbolic identifiers -- attach primes
  3899 instead of base 26 numbers.
  3900 
  3901 * New flag show_question_marks controls printing of leading question
  3902 marks in schematic variable names.
  3903 
  3904 * In schematic variable names, *any* symbol following \<^isub> or
  3905 \<^isup> is now treated as part of the base name.  For example, the
  3906 following works without printing of awkward ".0" indexes:
  3907 
  3908   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3909     by simp
  3910 
  3911 * Inner syntax includes (*(*nested*) comments*).
  3912 
  3913 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3914 annotations as "(00...)".
  3915 
  3916 * Clear separation of logical types and nonterminals, where the latter
  3917 may only occur in 'syntax' specifications or type abbreviations.
  3918 Before that distinction was only partially implemented via type class
  3919 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3920 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3921 exotic syntax specifications may require further adaption
  3922 (e.g. Cube/Cube.thy).
  3923 
  3924 * Removed obsolete type class "logic", use the top sort {} instead.
  3925 Note that non-logical types should be declared as 'nonterminals'
  3926 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3927 specifications.
  3928 
  3929 * Attributes 'induct' and 'cases': type or set names may now be
  3930 locally fixed variables as well.
  3931 
  3932 * Simplifier: can now control the depth to which conditional rewriting
  3933 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3934 Limit.
  3935 
  3936 * Simplifier: simplification procedures may now take the current
  3937 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3938 interface), which is very useful for calling the Simplifier
  3939 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3940 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3941 low-level mk_simproc no longer applies Logic.varify internally, to
  3942 allow for use in a context of fixed variables.
  3943 
  3944 * thin_tac now works even if the assumption being deleted contains !!
  3945 or ==>.  More generally, erule now works even if the major premise of
  3946 the elimination rule contains !! or ==>.
  3947 
  3948 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3949 
  3950 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3951 from Pure, which contains all common declarations already.  Both
  3952 theories are defined via plain Isabelle/Isar .thy files.
  3953 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3954 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3955 use isatool fixcpure to adapt your theory and ML sources.
  3956 
  3957 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3958 selections of theorems in named facts via index ranges.
  3959 
  3960 * 'print_theorems': in theory mode, really print the difference
  3961 wrt. the last state (works for interactive theory development only),
  3962 in proof mode print all local facts (cf. 'print_facts');
  3963 
  3964 * 'hide': option '(open)' hides only base names.
  3965 
  3966 * More efficient treatment of intermediate checkpoints in interactive
  3967 theory development.
  3968 
  3969 * Code generator is now invoked via code_module (incremental code
  3970 generation) and code_library (modular code generation, ML structures
  3971 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3972 must be quoted when used as identifiers.
  3973 
  3974 * New 'value' command for reading, evaluating and printing terms using
  3975 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3976 quoted when used as identifier.
  3977 
  3978 
  3979 *** Locales ***
  3980 
  3981 * New commands for the interpretation of locale expressions in
  3982 theories (1), locales (2) and proof contexts (3).  These generate
  3983 proof obligations from the expression specification.  After the
  3984 obligations have been discharged, theorems of the expression are added
  3985 to the theory, target locale or proof context.  The synopsis of the
  3986 commands is a follows:
  3987 
  3988   (1) interpretation expr inst
  3989   (2) interpretation target < expr
  3990   (3) interpret expr inst
  3991 
  3992 Interpretation in theories and proof contexts require a parameter
  3993 instantiation of terms from the current context.  This is applied to
  3994 specifications and theorems of the interpreted expression.
  3995 Interpretation in locales only permits parameter renaming through the
  3996 locale expression.  Interpretation is smart in that interpretations
  3997 that are active already do not occur in proof obligations, neither are
  3998 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3999 inspect active interpretations of a particular locale.  For details,
  4000 see the Isar Reference manual.  Examples can be found in
  4001 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4002 
  4003 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4004 'interpret' instead.
  4005 
  4006 * New context element 'constrains' for adding type constraints to
  4007 parameters.
  4008 
  4009 * Context expressions: renaming of parameters with syntax
  4010 redeclaration.
  4011 
  4012 * Locale declaration: 'includes' disallowed.
  4013 
  4014 * Proper static binding of attribute syntax -- i.e. types / terms /
  4015 facts mentioned as arguments are always those of the locale definition
  4016 context, independently of the context of later invocations.  Moreover,
  4017 locale operations (renaming and type / term instantiation) are applied
  4018 to attribute arguments as expected.
  4019 
  4020 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4021 actual attributes; rare situations may require Attrib.attribute to
  4022 embed those attributes into Attrib.src that lack concrete syntax.
  4023 Attribute implementations need to cooperate properly with the static
  4024 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4025 Attrib.XXX_thm etc. already do the right thing without further
  4026 intervention.  Only unusual applications -- such as "where" or "of"
  4027 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4028 on the context and the facts involved -- may have to assign parsed
  4029 values to argument tokens explicitly.
  4030 
  4031 * Changed parameter management in theorem generation for long goal
  4032 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4033 theorem statement in rare situations.
  4034 
  4035 * Locale inspection command 'print_locale' omits notes elements.  Use
  4036 'print_locale!' to have them included in the output.
  4037 
  4038 
  4039 *** Provers ***
  4040 
  4041 * Provers/hypsubst.ML: improved version of the subst method, for
  4042 single-step rewriting: it now works in bound variable contexts. New is
  4043 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4044 rewrite a different subterm than the original subst method, which is
  4045 still available as 'simplesubst'.
  4046 
  4047 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4048 and quasi orders.
  4049 
  4050 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4051 reflexive-transitive closure of relations.
  4052 
  4053 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4054 limit (previously hard-coded with a value of 20) user-definable.
  4055 
  4056 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4057 is peformed already.  Object-logics merely need to finish their
  4058 initial simpset configuration as before.  INCOMPATIBILITY.
  4059 
  4060 
  4061 *** HOL ***
  4062 
  4063 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4064 
  4065   syntax (epsilon)
  4066     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4067 
  4068 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4069 and x-symbol; use option '-m epsilon' to get it actually printed.
  4070 Moreover, the mathematically important symbolic identifier \<epsilon>
  4071 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4072 
  4073 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4074 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4075 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4076 support corresponding Isar calculations.
  4077 
  4078 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4079 instead of ":".
  4080 
  4081 * theory SetInterval: changed the syntax for open intervals:
  4082 
  4083   Old       New
  4084   {..n(}    {..<n}
  4085   {)n..}    {n<..}
  4086   {m..n(}   {m..<n}
  4087   {)m..n}   {m<..n}
  4088   {)m..n(}  {m<..<n}
  4089 
  4090 The old syntax is still supported but will disappear in the next
  4091 release.  For conversion use the following Emacs search and replace
  4092 patterns (these are not perfect but work quite well):
  4093 
  4094   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4095   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4096 
  4097 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4098 equalities in commutative rings; method 'algebra' provides a generic
  4099 interface.
  4100 
  4101 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4102 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4103 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4104 be a tuple pattern.
  4105 
  4106 Some new syntax forms are available:
  4107 
  4108   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4109   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4110   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4111   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4112 
  4113 The latter form "\<Sum>x < k. e" used to be based on a separate
  4114 function "Summation", which has been discontinued.
  4115 
  4116 * theory Finite_Set: in structured induction proofs, the insert case
  4117 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4118 (insert F x)'.
  4119 
  4120 * The 'refute' command has been extended to support a much larger
  4121 fragment of HOL, including axiomatic type classes, constdefs and
  4122 typedefs, inductive datatypes and recursion.
  4123 
  4124 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4125 Requires zChaff with proof generation to be installed.  See
  4126 HOL/ex/SAT_Examples.thy for examples.
  4127 
  4128 * Datatype induction via method 'induct' now preserves the name of the
  4129 induction variable. For example, when proving P(xs::'a list) by
  4130 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4131 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4132 in unstructured proof scripts.
  4133 
  4134 * Reworked implementation of records.  Improved scalability for
  4135 records with many fields, avoiding performance problems for type
  4136 inference. Records are no longer composed of nested field types, but
  4137 of nested extension types. Therefore the record type only grows linear
  4138 in the number of extensions and not in the number of fields.  The
  4139 top-level (users) view on records is preserved.  Potential
  4140 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4141 old record representation. The type generated for a record is called
  4142 <record_name>_ext_type.
  4143 
  4144 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4145 proofs triggered by a record definition or a simproc (if
  4146 quick_and_dirty is enabled).  Definitions of large records can take
  4147 quite long.
  4148 
  4149 New simproc record_upd_simproc for simplification of multiple record
  4150 updates enabled by default.  Moreover, trivial updates are also
  4151 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4152 occasionally, since simplification is more powerful by default.
  4153 
  4154 * typedef: proper support for polymorphic sets, which contain extra
  4155 type-variables in the term.
  4156 
  4157 * Simplifier: automatically reasons about transitivity chains
  4158 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4159 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4160 old proofs break occasionally as simplification may now solve more
  4161 goals than previously.
  4162 
  4163 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4164 present.  Works for all partial orders (class "order"), in particular
  4165 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4166 just like y <= x.
  4167 
  4168 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4169 bound variable or a constant then the let is unfolded.  Otherwise
  4170 first a is simplified to b, and then f b is simplified to g. If
  4171 possible we abstract b from g arriving at "let x = b in h x",
  4172 otherwise we unfold the let and arrive at g.  The simproc can be
  4173 enabled/disabled by the reference use_let_simproc.  Potential
  4174 INCOMPATIBILITY since simplification is more powerful by default.
  4175 
  4176 * Classical reasoning: the meson method now accepts theorems as arguments.
  4177 
  4178 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4179 jobs to provide advice on the provability of subgoals.
  4180 
  4181 * Theory OrderedGroup and Ring_and_Field: various additions and
  4182 improvements to faciliate calculations involving equalities and
  4183 inequalities.
  4184 
  4185 The following theorems have been eliminated or modified
  4186 (INCOMPATIBILITY):
  4187 
  4188   abs_eq             now named abs_of_nonneg
  4189   abs_of_ge_0        now named abs_of_nonneg
  4190   abs_minus_eq       now named abs_of_nonpos
  4191   imp_abs_id         now named abs_of_nonneg
  4192   imp_abs_neg_id     now named abs_of_nonpos
  4193   mult_pos           now named mult_pos_pos
  4194   mult_pos_le        now named mult_nonneg_nonneg
  4195   mult_pos_neg_le    now named mult_nonneg_nonpos
  4196   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4197   mult_neg           now named mult_neg_neg
  4198   mult_neg_le        now named mult_nonpos_nonpos
  4199 
  4200 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4201      
  4202      zero_le_square
  4203      not_square_less_zero 
  4204 
  4205   The following lemmas have been deleted from Real/RealPow:
  4206   
  4207      realpow_zero_zero
  4208      realpow_two
  4209      realpow_less
  4210      zero_le_power
  4211      realpow_two_le
  4212      abs_realpow_two
  4213      realpow_two_abs     
  4214 
  4215 * Theory Parity: added rules for simplifying exponents.
  4216 
  4217 * Theory List:
  4218 
  4219 The following theorems have been eliminated or modified
  4220 (INCOMPATIBILITY):
  4221 
  4222   list_all_Nil       now named list_all.simps(1)
  4223   list_all_Cons      now named list_all.simps(2)
  4224   list_all_conv      now named list_all_iff
  4225   set_mem_eq         now named mem_iff
  4226 
  4227 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4228 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4229 
  4230 
  4231 *** HOL-Complex ***
  4232 
  4233 * Theory RealDef: better support for embedding natural numbers and
  4234 integers in the reals.
  4235 
  4236 The following theorems have been eliminated or modified
  4237 (INCOMPATIBILITY):
  4238 
  4239   exp_ge_add_one_self  now requires no hypotheses
  4240   real_of_int_add      reversed direction of equality (use [symmetric])
  4241   real_of_int_minus    reversed direction of equality (use [symmetric])
  4242   real_of_int_diff     reversed direction of equality (use [symmetric])
  4243   real_of_int_mult     reversed direction of equality (use [symmetric])
  4244 
  4245 * Theory RComplete: expanded support for floor and ceiling functions.
  4246 
  4247 * Theory Ln is new, with properties of the natural logarithm
  4248 
  4249 * Hyperreal: There is a new type constructor "star" for making
  4250 nonstandard types.  The old type names are now type synonyms:
  4251 
  4252   hypreal = real star
  4253   hypnat = nat star
  4254   hcomplex = complex star
  4255 
  4256 * Hyperreal: Many groups of similarly-defined constants have been
  4257 replaced by polymorphic versions (INCOMPATIBILITY):
  4258 
  4259   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4260 
  4261   starset      <-- starsetNat, starsetC
  4262   *s*          <-- *sNat*, *sc*
  4263   starset_n    <-- starsetNat_n, starsetC_n
  4264   *sn*         <-- *sNatn*, *scn*
  4265   InternalSets <-- InternalNatSets, InternalCSets
  4266 
  4267   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4268   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4269   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4270   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4271   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4272 
  4273 * Hyperreal: Many type-specific theorems have been removed in favor of
  4274 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4275 
  4276   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4277   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4278   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4279   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4280   right_minus <-- hypreal_add_minus
  4281   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4282   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4283   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4284   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4285   mult_1_right <-- hcomplex_mult_one_right
  4286   mult_zero_left <-- hcomplex_mult_zero_left
  4287   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4288   right_distrib <-- hypnat_add_mult_distrib2
  4289   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4290   right_inverse <-- hypreal_mult_inverse
  4291   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4292   order_refl <-- {hypreal,hypnat}_le_refl
  4293   order_trans <-- {hypreal,hypnat}_le_trans
  4294   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4295   order_less_le <-- {hypreal,hypnat}_less_le
  4296   linorder_linear <-- {hypreal,hypnat}_le_linear
  4297   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4298   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4299   add_nonneg_nonneg <-- hypreal_le_add_order
  4300 
  4301 * Hyperreal: Separate theorems having to do with type-specific
  4302 versions of constants have been merged into theorems that apply to the
  4303 new polymorphic constants (INCOMPATIBILITY):
  4304 
  4305   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4306   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4307   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4308   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4309   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4310   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4311   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4312   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4313   STAR_diff <-- {STAR,STARC}_diff
  4314   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4315     STARC_hcomplex_of_complex}_image_subset
  4316   starset_n_Un <-- starset{Nat,C}_n_Un
  4317   starset_n_Int <-- starset{Nat,C}_n_Int
  4318   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4319   starset_n_diff <-- starset{Nat,C}_n_diff
  4320   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4321   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4322   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4323   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4324   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4325   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4326   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4327   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4328   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4329   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4330   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4331   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4332   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4333   starfun_diff <-- starfun{C,RC,CR}_diff
  4334   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4335   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4336   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4337   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4338   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4339   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4340   starfun_Id <-- starfunC_Id
  4341   starfun_approx <-- starfun{Nat,CR}_approx
  4342   starfun_capprox <-- starfun{C,RC}_capprox
  4343   starfun_abs <-- starfunNat_rabs
  4344   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4345   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4346   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4347   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4348   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4349   starfun_add_approx <-- starfunCR_add_approx
  4350   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4351   starfun_divide <-- starfun{C,CR,RC}_divide
  4352   starfun_n <-- starfun{Nat,C}_n
  4353   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4354   starfun_n_add <-- starfun{Nat,C}_n_add
  4355   starfun_n_add_minus <-- starfunNat_n_add_minus
  4356   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4357   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4358   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4359 
  4360   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4361   star_n_minus <-- {hypreal,hcomplex}_minus
  4362   star_n_diff <-- {hypreal,hcomplex}_diff
  4363   star_n_mult <-- {hypreal,hcomplex}_mult
  4364   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4365   star_n_le <-- {hypreal,hypnat}_le
  4366   star_n_less <-- {hypreal,hypnat}_less
  4367   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4368   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4369   star_n_abs <-- hypreal_hrabs
  4370   star_n_divide <-- hcomplex_divide
  4371 
  4372   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4373   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4374   star_of_diff <-- hypreal_of_real_diff
  4375   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4376   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4377   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4378   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4379   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4380   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4381   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4382   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4383   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4384   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4385   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4386   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4387   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4388   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4389   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4390   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4391   star_of_power <-- hypreal_of_real_power
  4392   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4393 
  4394 * Hyperreal: new method "transfer" that implements the transfer
  4395 principle of nonstandard analysis. With a subgoal that mentions
  4396 nonstandard types like "'a star", the command "apply transfer"
  4397 replaces it with an equivalent one that mentions only standard types.
  4398 To be successful, all free variables must have standard types; non-
  4399 standard variables must have explicit universal quantifiers.
  4400 
  4401 * Hyperreal: A theory of Taylor series.
  4402 
  4403 
  4404 *** HOLCF ***
  4405 
  4406 * Discontinued special version of 'constdefs' (which used to support
  4407 continuous functions) in favor of the general Pure one with full
  4408 type-inference.
  4409 
  4410 * New simplification procedure for solving continuity conditions; it
  4411 is much faster on terms with many nested lambda abstractions (cubic
  4412 instead of exponential time).
  4413 
  4414 * New syntax for domain package: selector names are now optional.
  4415 Parentheses should be omitted unless argument is lazy, for example:
  4416 
  4417   domain 'a stream = cons "'a" (lazy "'a stream")
  4418 
  4419 * New command 'fixrec' for defining recursive functions with pattern
  4420 matching; defining multiple functions with mutual recursion is also
  4421 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4422 sinr, or any data constructor defined by the domain package. The given
  4423 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4424 syntax and examples.
  4425 
  4426 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4427 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4428 but the proof obligation additionally includes an admissibility
  4429 requirement. The packages generate instances of class cpo or pcpo,
  4430 with continuity and strictness theorems for Rep and Abs.
  4431 
  4432 * HOLCF: Many theorems have been renamed according to a more standard naming
  4433 scheme (INCOMPATIBILITY):
  4434 
  4435   foo_inject:  "foo$x = foo$y ==> x = y"
  4436   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4437   foo_less:    "(foo$x << foo$y) = (x << y)"
  4438   foo_strict:  "foo$UU = UU"
  4439   foo_defined: "... ==> foo$x ~= UU"
  4440   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4441 
  4442 
  4443 *** ZF ***
  4444 
  4445 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4446 including the First Isomorphism Theorem (on quotienting by the kernel
  4447 of a homomorphism).
  4448 
  4449 * ZF/Simplifier: install second copy of type solver that actually
  4450 makes use of TC rules declared to Isar proof contexts (or locales);
  4451 the old version is still required for ML proof scripts.
  4452 
  4453 
  4454 *** Cube ***
  4455 
  4456 * Converted to Isar theory format; use locales instead of axiomatic
  4457 theories.
  4458 
  4459 
  4460 *** ML ***
  4461 
  4462 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4463 for ||>, ||>>, |>>,
  4464 
  4465 * Pure/library.ML no longer defines its own option datatype, but uses
  4466 that of the SML basis, which has constructors NONE and SOME instead of
  4467 None and Some, as well as exception Option.Option instead of OPTION.
  4468 The functions the, if_none, is_some, is_none have been adapted
  4469 accordingly, while Option.map replaces apsome.
  4470 
  4471 * Pure/library.ML: the exception LIST has been given up in favour of
  4472 the standard exceptions Empty and Subscript, as well as
  4473 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4474 superceded by the standard hd and tl functions etc.
  4475 
  4476 A number of basic list functions are no longer exported to the ML
  4477 toplevel, as they are variants of predefined functions.  The following
  4478 suggests how one can translate existing code:
  4479 
  4480     rev_append xs ys = List.revAppend (xs, ys)
  4481     nth_elem (i, xs) = List.nth (xs, i)
  4482     last_elem xs = List.last xs
  4483     flat xss = List.concat xss
  4484     seq fs = List.app fs
  4485     partition P xs = List.partition P xs
  4486     mapfilter f xs = List.mapPartial f xs
  4487 
  4488 * Pure/library.ML: several combinators for linear functional
  4489 transformations, notably reverse application and composition:
  4490 
  4491   x |> f                f #> g
  4492   (x, y) |-> f          f #-> g
  4493 
  4494 * Pure/library.ML: introduced/changed precedence of infix operators:
  4495 
  4496   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4497   infix 2 ?;
  4498   infix 3 o oo ooo oooo;
  4499   infix 4 ~~ upto downto;
  4500 
  4501 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4502 infix operators.
  4503 
  4504 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4505 fold_map support linear functional transformations and nesting.  For
  4506 example:
  4507 
  4508   fold f [x1, ..., xN] y =
  4509     y |> f x1 |> ... |> f xN
  4510 
  4511   (fold o fold) f [xs1, ..., xsN] y =
  4512     y |> fold f xs1 |> ... |> fold f xsN
  4513 
  4514   fold f [x1, ..., xN] =
  4515     f x1 #> ... #> f xN
  4516 
  4517   (fold o fold) f [xs1, ..., xsN] =
  4518     fold f xs1 #> ... #> fold f xsN
  4519 
  4520 * Pure/library.ML: the following selectors on type 'a option are
  4521 available:
  4522 
  4523   the:               'a option -> 'a  (*partial*)
  4524   these:             'a option -> 'a  where 'a = 'b list
  4525   the_default: 'a -> 'a option -> 'a
  4526   the_list:          'a option -> 'a list
  4527 
  4528 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4529 basic operations for association lists, following natural argument
  4530 order; moreover the explicit equality predicate passed here avoids
  4531 potentially expensive polymorphic runtime equality checks.
  4532 The old functions may be expressed as follows:
  4533 
  4534   assoc = uncurry (AList.lookup (op =))
  4535   assocs = these oo AList.lookup (op =)
  4536   overwrite = uncurry (AList.update (op =)) o swap
  4537 
  4538 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4539 
  4540   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4541   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4542 
  4543 replacing make_keylist and keyfilter (occassionally used)
  4544 Naive rewrites:
  4545 
  4546   make_keylist = AList.make
  4547   keyfilter = AList.find (op =)
  4548 
  4549 * eq_fst and eq_snd now take explicit equality parameter, thus
  4550   avoiding eqtypes. Naive rewrites:
  4551 
  4552     eq_fst = eq_fst (op =)
  4553     eq_snd = eq_snd (op =)
  4554 
  4555 * Removed deprecated apl and apr (rarely used).
  4556   Naive rewrites:
  4557 
  4558     apl (n, op) =>>= curry op n
  4559     apr (op, m) =>>= fn n => op (n, m)
  4560 
  4561 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4562 provides a reasonably efficient light-weight implementation of sets as
  4563 lists.
  4564 
  4565 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4566 few new operations; existing lookup and update are now curried to
  4567 follow natural argument order (for use with fold etc.);
  4568 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4569 
  4570 * Pure/General: output via the Isabelle channels of
  4571 writeln/warning/error etc. is now passed through Output.output, with a
  4572 hook for arbitrary transformations depending on the print_mode
  4573 (cf. Output.add_mode -- the first active mode that provides a output
  4574 function wins).  Already formatted output may be embedded into further
  4575 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4576 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4577 accommodate easy composition of diagnostic messages etc.  Programmers
  4578 rarely need to care about Output.output or Output.raw at all, with
  4579 some notable exceptions: Output.output is required when bypassing the
  4580 standard channels (writeln etc.), or in token translations to produce
  4581 properly formatted results; Output.raw is required when capturing
  4582 already output material that will eventually be presented to the user
  4583 a second time.  For the default print mode, both Output.output and
  4584 Output.raw have no effect.
  4585 
  4586 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4587 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4588 cumulative results are displayed at the end of a batch session.
  4589 
  4590 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4591 replaced by File.platform_path and File.shell_path (with appropriate
  4592 hooks).  This provides a clean interface for unusual systems where the
  4593 internal and external process view of file names are different.
  4594 
  4595 * Pure: more efficient orders for basic syntactic entities: added
  4596 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4597 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4598 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4599 orders now -- potential INCOMPATIBILITY for code that depends on a
  4600 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4601 Library.sort_strings on result).
  4602 
  4603 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4604 fold_types traverse types/terms from left to right, observing natural
  4605 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4606 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4607 
  4608 * Pure: name spaces have been refined, with significant changes of the
  4609 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4610 to extern(_table).  The plain name entry path is superceded by a
  4611 general 'naming' context, which also includes the 'policy' to produce
  4612 a fully qualified name and external accesses of a fully qualified
  4613 name; NameSpace.extend is superceded by context dependent
  4614 Sign.declare_name.  Several theory and proof context operations modify
  4615 the naming context.  Especially note Theory.restore_naming and
  4616 ProofContext.restore_naming to get back to a sane state; note that
  4617 Theory.add_path is no longer sufficient to recover from
  4618 Theory.absolute_path in particular.
  4619 
  4620 * Pure: new flags short_names (default false) and unique_names
  4621 (default true) for controlling output of qualified names.  If
  4622 short_names is set, names are printed unqualified.  If unique_names is
  4623 reset, the name prefix is reduced to the minimum required to achieve
  4624 the original result when interning again, even if there is an overlap
  4625 with earlier declarations.
  4626 
  4627 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4628 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4629 (useful for printing error messages).  INCOMPATIBILITY.
  4630 
  4631 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4632 Theory.theory are now identified, referring to the universal
  4633 Context.theory (see Pure/context.ML).  Actual signature and theory
  4634 content is managed as theory data.  The old code and interfaces were
  4635 spread over many files and structures; the new arrangement introduces
  4636 considerable INCOMPATIBILITY to gain more clarity:
  4637 
  4638   Context -- theory management operations (name, identity, inclusion,
  4639     parents, ancestors, merge, etc.), plus generic theory data;
  4640 
  4641   Sign -- logical signature and syntax operations (declaring consts,
  4642     types, etc.), plus certify/read for common entities;
  4643 
  4644   Theory -- logical theory operations (stating axioms, definitions,
  4645     oracles), plus a copy of logical signature operations (consts,
  4646     types, etc.); also a few basic management operations (Theory.copy,
  4647     Theory.merge, etc.)
  4648 
  4649 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4650 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4651 for convenience -- they merely return the theory.
  4652 
  4653 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4654 
  4655 * Pure: the Isar proof context type is already defined early in Pure
  4656 as Context.proof (note that ProofContext.context and Proof.context are
  4657 aliases, where the latter is the preferred name).  This enables other
  4658 Isabelle components to refer to that type even before Isar is present.
  4659 
  4660 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4661 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4662 any of these kinds.  For example, Sign.intern typeK is now
  4663 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4664 Theory.hide_types.  Also note that former
  4665 Theory.hide_classes/types/consts are now
  4666 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4667 internalize their arguments!  INCOMPATIBILITY.
  4668 
  4669 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4670 datatype thmref (with constructors Name and NameSelection) instead of
  4671 plain string -- INCOMPATIBILITY;
  4672 
  4673 * Pure: cases produced by proof methods specify options, where NONE
  4674 means to remove case bindings -- INCOMPATIBILITY in
  4675 (RAW_)METHOD_CASES.
  4676 
  4677 * Pure: the following operations retrieve axioms or theorems from a
  4678 theory node or theory hierarchy, respectively:
  4679 
  4680   Theory.axioms_of: theory -> (string * term) list
  4681   Theory.all_axioms_of: theory -> (string * term) list
  4682   PureThy.thms_of: theory -> (string * thm) list
  4683   PureThy.all_thms_of: theory -> (string * thm) list
  4684 
  4685 * Pure: print_tac now outputs the goal through the trace channel.
  4686 
  4687 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4688 Reference Toplevel.debug (default false) controls detailed printing
  4689 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4690 controls execution profiling -- set to 1 for time and 2 for space
  4691 (both increase the runtime).
  4692 
  4693 * Isar session: The initial use of ROOT.ML is now always timed,
  4694 i.e. the log will show the actual process times, in contrast to the
  4695 elapsed wall-clock time that the outer shell wrapper produces.
  4696 
  4697 * Simplifier: improved handling of bound variables (nameless
  4698 representation, avoid allocating new strings).  Simprocs that invoke
  4699 the Simplifier recursively should use Simplifier.inherit_bounds to
  4700 avoid local name clashes.  Failure to do so produces warnings
  4701 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4702 for further details.
  4703 
  4704 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4705 bindings for all theorems stored within a given theory; this may help
  4706 in porting non-Isar theories to Isar ones, while keeping ML proof
  4707 scripts for the time being.
  4708 
  4709 * ML operator HTML.with_charset specifies the charset begin used for
  4710 generated HTML files.  For example:
  4711 
  4712   HTML.with_charset "utf-8" use_thy "Hebrew";
  4713   HTML.with_charset "utf-8" use_thy "Chinese";
  4714 
  4715 
  4716 *** System ***
  4717 
  4718 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4719 isabelle, isatool etc.).
  4720 
  4721 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4722 isatool doc, isatool mkdir, display_drafts etc.).
  4723 
  4724 * isatool usedir: option -f allows specification of the ML file to be
  4725 used by Isabelle; default is ROOT.ML.
  4726 
  4727 * New isatool version outputs the version identifier of the Isabelle
  4728 distribution being used.
  4729 
  4730 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4731 (containing Boolean satisfiability problems) into Isabelle/HOL
  4732 theories.
  4733 
  4734 
  4735 
  4736 New in Isabelle2004 (April 2004)
  4737 --------------------------------
  4738 
  4739 *** General ***
  4740 
  4741 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4742   Replaces linorder.ML.
  4743 
  4744 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4745   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4746   (\<a>...\<z>), are now considered normal letters, and can therefore
  4747   be used anywhere where an ASCII letter (a...zA...Z) has until
  4748   now. COMPATIBILITY: This obviously changes the parsing of some
  4749   terms, especially where a symbol has been used as a binder, say
  4750   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4751   as an identifier.  Fix it by inserting a space around former
  4752   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4753   existing theory and ML files.
  4754 
  4755 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4756 
  4757 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4758   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4759   a normal (but invisible) letter. For multiple letter subscripts repeat
  4760   \<^isub> like this: x\<^isub>1\<^isub>2.
  4761 
  4762 * Pure: There are now sub-/superscripts that can span more than one
  4763   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4764   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4765   superscript. The new control characters are not identifier parts.
  4766 
  4767 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4768   content of "..." to the latex file instead of \isacntrl... . The "..."
  4769   may consist of any printable characters excluding the end bracket >.
  4770 
  4771 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4772   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4773   declare constants "final", which prevents their being given a definition
  4774   later.  It is useful for constants whose behaviour is fixed axiomatically
  4775   rather than definitionally, such as the meta-logic connectives.
  4776 
  4777 * Pure: 'instance' now handles general arities with general sorts
  4778   (i.e. intersections of classes),
  4779 
  4780 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4781   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4782   It can be changed to alter the colors/layout of generated pages.
  4783 
  4784 
  4785 *** Isar ***
  4786 
  4787 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4788   cut_tac, subgoal_tac and thin_tac:
  4789   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4790     locales are no longer forced to write Isar proof scripts.
  4791     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4792     emulations.
  4793   - INCOMPATIBILITY: names of variables to be instantiated may no
  4794     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4795     This is consistent with the instantiation attribute "where".
  4796 
  4797 * Attributes "where" and "of":
  4798   - Now take type variables of instantiated theorem into account when reading
  4799     the instantiation string.  This fixes a bug that caused instantiated
  4800     theorems to have too special types in some circumstances.
  4801   - "where" permits explicit instantiations of type variables.
  4802 
  4803 * Calculation commands "moreover" and "also" no longer interfere with
  4804   current facts ("this"), admitting arbitrary combinations with "then"
  4805   and derived forms.
  4806 
  4807 * Locales:
  4808   - Goal statements involving the context element "includes" no longer
  4809     generate theorems with internal delta predicates (those ending on
  4810     "_axioms") in the premise.
  4811     Resolve particular premise with <locale>.intro to obtain old form.
  4812   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4813     specification and "includes" elements in goal statement.
  4814   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4815     [intro?] and [elim?] (respectively) by default.
  4816   - Experimental command for instantiation of locales in proof contexts:
  4817         instantiate <label>[<attrs>]: <loc>
  4818     Instantiates locale <loc> and adds all its theorems to the current context
  4819     taking into account their attributes.  Label and attrs are optional
  4820     modifiers, like in theorem declarations.  If present, names of
  4821     instantiated theorems are qualified with <label>, and the attributes
  4822     <attrs> are applied after any attributes these theorems might have already.
  4823       If the locale has assumptions, a chained fact of the form
  4824     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4825     are derived.  The command does not support old-style locales declared
  4826     with "locale (open)".
  4827       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4828 
  4829 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4830   (Isar) contexts.
  4831 
  4832 
  4833 *** HOL ***
  4834 
  4835 * Proof import: new image HOL4 contains the imported library from
  4836   the HOL4 system with about 2500 theorems. It is imported by
  4837   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4838   can be used like any other Isabelle image.  See
  4839   HOL/Import/HOL/README for more information.
  4840 
  4841 * Simplifier:
  4842   - Much improved handling of linear and partial orders.
  4843     Reasoners for linear and partial orders are set up for type classes
  4844     "linorder" and "order" respectively, and are added to the default simpset
  4845     as solvers.  This means that the simplifier can build transitivity chains
  4846     to solve goals from the assumptions.
  4847   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4848     of blast or auto after simplification become unnecessary because the goal
  4849     is solved by simplification already.
  4850 
  4851 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4852     all proved in axiomatic type classes for semirings, rings and fields.
  4853 
  4854 * Numerics:
  4855   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4856     now formalized using the Ring_and_Field theory mentioned above.
  4857   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4858     than before, because now they are set up once in a generic manner.
  4859   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4860     Look for the general versions in Ring_and_Field (and Power if they concern
  4861     exponentiation).
  4862 
  4863 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4864 
  4865 * Records:
  4866   - Record types are now by default printed with their type abbreviation
  4867     instead of the list of all field types. This can be configured via
  4868     the reference "print_record_type_abbr".
  4869   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4870     (not enabled by default).
  4871   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4872     EX x. x = sel r to True (not enabled by default).
  4873   - Tactic "record_split_simp_tac" to split and simplify records added.
  4874 
  4875 * 'specification' command added, allowing for definition by
  4876   specification.  There is also an 'ax_specification' command that
  4877   introduces the new constants axiomatically.
  4878 
  4879 * arith(_tac) is now able to generate counterexamples for reals as well.
  4880 
  4881 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4882 
  4883 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4884   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4885 
  4886 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4887   matrix theory to linear programming.
  4888 
  4889 * Unions and Intersections:
  4890   The latex output syntax of UN and INT has been changed
  4891   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4892   i.e. the index formulae has become a subscript.
  4893   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4894 
  4895 * Unions and Intersections over Intervals:
  4896   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4897   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4898   like in normal math, and corresponding versions for < and for intersection.
  4899 
  4900 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4901   lexicographic dictonary ordering has been added as "lexord".
  4902 
  4903 * ML: the legacy theory structures Int and List have been removed. They had
  4904   conflicted with ML Basis Library structures having the same names.
  4905 
  4906 * 'refute' command added to search for (finite) countermodels.  Only works
  4907   for a fragment of HOL.  The installation of an external SAT solver is
  4908   highly recommended.  See "HOL/Refute.thy" for details.
  4909 
  4910 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4911   formulae under an assignment of free variables to random values.
  4912   In contrast to 'refute', it can deal with inductive datatypes,
  4913   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4914   for examples.
  4915 
  4916 
  4917 *** HOLCF ***
  4918 
  4919 * Streams now come with concatenation and are part of the HOLCF image
  4920 
  4921 
  4922 
  4923 New in Isabelle2003 (May 2003)
  4924 ------------------------------
  4925 
  4926 *** General ***
  4927 
  4928 * Provers/simplifier:
  4929 
  4930   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4931     Assumptions are now subject to complete mutual simplification,
  4932     not just from left to right. The simplifier now preserves
  4933     the order of assumptions.
  4934 
  4935     Potential INCOMPATIBILITY:
  4936 
  4937     -- simp sometimes diverges where the old version did
  4938        not, e.g. invoking simp on the goal
  4939 
  4940         [| P (f x); y = x; f x = f y |] ==> Q
  4941 
  4942        now gives rise to the infinite reduction sequence
  4943 
  4944         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4945 
  4946        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4947        kind of problem.
  4948 
  4949     -- Tactics combining classical reasoner and simplification (such as auto)
  4950        are also affected by this change, because many of them rely on
  4951        simp. They may sometimes diverge as well or yield a different numbers
  4952        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4953        in case of problems. Sometimes subsequent calls to the classical
  4954        reasoner will fail because a preceeding call to the simplifier too
  4955        eagerly simplified the goal, e.g. deleted redundant premises.
  4956 
  4957   - The simplifier trace now shows the names of the applied rewrite rules
  4958 
  4959   - You can limit the number of recursive invocations of the simplifier
  4960     during conditional rewriting (where the simplifie tries to solve the
  4961     conditions before applying the rewrite rule):
  4962     ML "simp_depth_limit := n"
  4963     where n is an integer. Thus you can force termination where previously
  4964     the simplifier would diverge.
  4965 
  4966   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4967 
  4968   - No longer aborts on failed congruence proof.  Instead, the
  4969     congruence is ignored.
  4970 
  4971 * Pure: New generic framework for extracting programs from constructive
  4972   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4973   as HOL/Extraction for some case studies.
  4974 
  4975 * Pure: The main goal of the proof state is no longer shown by default, only
  4976 the subgoals. This behaviour is controlled by a new flag.
  4977    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4978 (ML: Proof.show_main_goal).
  4979 
  4980 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4981 rules whose conclusion matches subgoal 1:
  4982       PG menu: Isabelle/Isar -> Show me -> matching rules
  4983 The rules are ordered by how closely they match the subgoal.
  4984 In particular, rules that solve a subgoal outright are displayed first
  4985 (or rather last, the way they are printed).
  4986 (ML: ProofGeneral.print_intros())
  4987 
  4988 * Pure: New flag trace_unify_fail causes unification to print
  4989 diagnostic information (PG: in trace buffer) when it fails. This is
  4990 useful for figuring out why single step proofs like rule, erule or
  4991 assumption failed.
  4992 
  4993 * Pure: Locale specifications now produce predicate definitions
  4994 according to the body of text (covering assumptions modulo local
  4995 definitions); predicate "loc_axioms" covers newly introduced text,
  4996 while "loc" is cumulative wrt. all included locale expressions; the
  4997 latter view is presented only on export into the global theory
  4998 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4999 on the old view without predicates;
  5000 
  5001 * Pure: predefined locales "var" and "struct" are useful for sharing
  5002 parameters (as in CASL, for example); just specify something like
  5003 ``var x + var y + struct M'' as import;
  5004 
  5005 * Pure: improved thms_containing: proper indexing of facts instead of
  5006 raw theorems; check validity of results wrt. current name space;
  5007 include local facts of proof configuration (also covers active
  5008 locales), cover fixed variables in index; may use "_" in term
  5009 specification; an optional limit for the number of printed facts may
  5010 be given (the default is 40);
  5011 
  5012 * Pure: disallow duplicate fact bindings within new-style theory files
  5013 (batch-mode only);
  5014 
  5015 * Provers: improved induct method: assumptions introduced by case
  5016 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5017 the goal statement); "foo" still refers to all facts collectively;
  5018 
  5019 * Provers: the function blast.overloaded has been removed: all constants
  5020 are regarded as potentially overloaded, which improves robustness in exchange
  5021 for slight decrease in efficiency;
  5022 
  5023 * Provers/linorder: New generic prover for transitivity reasoning over
  5024 linear orders.  Note: this prover is not efficient!
  5025 
  5026 * Isar: preview of problems to finish 'show' now produce an error
  5027 rather than just a warning (in interactive mode);
  5028 
  5029 
  5030 *** HOL ***
  5031 
  5032 * arith(_tac)
  5033 
  5034  - Produces a counter example if it cannot prove a goal.
  5035    Note that the counter example may be spurious if the goal is not a formula
  5036    of quantifier-free linear arithmetic.
  5037    In ProofGeneral the counter example appears in the trace buffer.
  5038 
  5039  - Knows about div k and mod k where k is a numeral of type nat or int.
  5040 
  5041  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5042    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5043    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5044 
  5045 * simp's arithmetic capabilities have been enhanced a bit: it now
  5046 takes ~= in premises into account (by performing a case split);
  5047 
  5048 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5049 are distributed over a sum of terms;
  5050 
  5051 * New tactic "trans_tac" and method "trans" instantiate
  5052 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5053 "<=", "<" and "=").
  5054 
  5055 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5056 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5057 
  5058 * 'typedef' command has new option "open" to suppress the set
  5059 definition;
  5060 
  5061 * functions Min and Max on finite sets have been introduced (theory
  5062 Finite_Set);
  5063 
  5064 * attribute [symmetric] now works for relations as well; it turns
  5065 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5066 
  5067 * induct over a !!-quantified statement (say !!x1..xn):
  5068   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5069 
  5070 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5071 %x. None. Warning: empty_def now refers to the previously hidden definition
  5072 of the empty set.
  5073 
  5074 * Algebra: formalization of classical algebra.  Intended as base for
  5075 any algebraic development in Isabelle.  Currently covers group theory
  5076 (up to Sylow's theorem) and ring theory (Universal Property of
  5077 Univariate Polynomials).  Contributions welcome;
  5078 
  5079 * GroupTheory: deleted, since its material has been moved to Algebra;
  5080 
  5081 * Complex: new directory of the complex numbers with numeric constants,
  5082 nonstandard complex numbers, and some complex analysis, standard and
  5083 nonstandard (Jacques Fleuriot);
  5084 
  5085 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5086 
  5087 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5088 Fleuriot);
  5089 
  5090 * Real/HahnBanach: updated and adapted to locales;
  5091 
  5092 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5093 Gray and Kramer);
  5094 
  5095 * UNITY: added the Meier-Sanders theory of progress sets;
  5096 
  5097 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5098 as abstract algorithms, instantiated to the JVM;
  5099 
  5100 * Bali: Java source language formalization. Type system, operational
  5101 semantics, axiomatic semantics. Supported language features:
  5102 classes, interfaces, objects,virtual methods, static methods,
  5103 static/instance fields, arrays, access modifiers, definite
  5104 assignment, exceptions.
  5105 
  5106 
  5107 *** ZF ***
  5108 
  5109 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5110 universe, etc.);
  5111 
  5112 * Main ZF: virtually all theories converted to new-style format;
  5113 
  5114 
  5115 *** ML ***
  5116 
  5117 * Pure: Tactic.prove provides sane interface for internal proofs;
  5118 omits the infamous "standard" operation, so this is more appropriate
  5119 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5120 
  5121 * Pure: improved error reporting of simprocs;
  5122 
  5123 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5124 up simprocs;
  5125 
  5126 
  5127 *** Document preparation ***
  5128 
  5129 * uses \par instead of \\ for line breaks in theory text. This may
  5130 shift some page breaks in large documents. To get the old behaviour
  5131 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5132 
  5133 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5134 other packages
  5135 
  5136 * \<euro> now needs package babel/greek instead of marvosym (which
  5137 broke \Rightarrow)
  5138 
  5139 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5140 textcomp package)
  5141 
  5142 
  5143 
  5144 New in Isabelle2002 (March 2002)
  5145 --------------------------------
  5146 
  5147 *** Document preparation ***
  5148 
  5149 * greatly simplified document preparation setup, including more
  5150 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5151 instructive isatool mkdir; users should basically be able to get
  5152 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5153 users may run a separate document processing stage manually like this:
  5154 "isatool usedir -D output HOL Test && isatool document Test/output";
  5155 
  5156 * theory dependency graph may now be incorporated into documents;
  5157 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5158 with \includegraphics of LaTeX;
  5159 
  5160 * proper spacing of consecutive markup elements, especially text
  5161 blocks after section headings;
  5162 
  5163 * support bold style (for single symbols only), input syntax is like
  5164 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5165 
  5166 * \<bullet> is now output as bold \cdot by default, which looks much
  5167 better in printed text;
  5168 
  5169 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5170 note that these symbols are currently unavailable in Proof General /
  5171 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5172 
  5173 * isatool latex no longer depends on changed TEXINPUTS, instead
  5174 isatool document copies the Isabelle style files to the target
  5175 location;
  5176 
  5177 
  5178 *** Isar ***
  5179 
  5180 * Pure/Provers: improved proof by cases and induction;
  5181   - 'case' command admits impromptu naming of parameters (such as
  5182     "case (Suc n)");
  5183   - 'induct' method divinates rule instantiation from the inductive
  5184     claim; no longer requires excessive ?P bindings for proper
  5185     instantiation of cases;
  5186   - 'induct' method properly enumerates all possibilities of set/type
  5187     rules; as a consequence facts may be also passed through *type*
  5188     rules without further ado;
  5189   - 'induct' method now derives symbolic cases from the *rulified*
  5190     rule (before it used to rulify cases stemming from the internal
  5191     atomized version); this means that the context of a non-atomic
  5192     statement becomes is included in the hypothesis, avoiding the
  5193     slightly cumbersome show "PROP ?case" form;
  5194   - 'induct' may now use elim-style induction rules without chaining
  5195     facts, using ``missing'' premises from the goal state; this allows
  5196     rules stemming from inductive sets to be applied in unstructured
  5197     scripts, while still benefitting from proper handling of non-atomic
  5198     statements; NB: major inductive premises need to be put first, all
  5199     the rest of the goal is passed through the induction;
  5200   - 'induct' proper support for mutual induction involving non-atomic
  5201     rule statements (uses the new concept of simultaneous goals, see
  5202     below);
  5203   - append all possible rule selections, but only use the first
  5204     success (no backtracking);
  5205   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5206   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5207   - added 'print_induct_rules' (covered by help item in recent Proof
  5208     General versions);
  5209   - moved induct/cases attributes to Pure, methods to Provers;
  5210   - generic method setup instantiated for FOL and HOL;
  5211 
  5212 * Pure: support multiple simultaneous goal statements, for example
  5213 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5214 meta-level mechanism, this acts as if several individual goals had
  5215 been stated separately; in particular common proof methods need to be
  5216 repeated in order to cover all claims; note that a single elimination
  5217 step is *not* sufficient to establish the two conjunctions, so this
  5218 fails:
  5219 
  5220   assume "A & B" then have A and B ..   (*".." fails*)
  5221 
  5222 better use "obtain" in situations as above; alternative refer to
  5223 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5224 
  5225 * Pure: proper integration with ``locales''; unlike the original
  5226 version by Florian Kammller, Isar locales package high-level proof
  5227 contexts rather than raw logical ones (e.g. we admit to include
  5228 attributes everywhere); operations on locales include merge and
  5229 rename; support for implicit arguments (``structures''); simultaneous
  5230 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5231 some examples;
  5232 
  5233 * Pure: the following commands have been ``localized'', supporting a
  5234 target locale specification "(in name)": 'lemma', 'theorem',
  5235 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5236 stored both within the locale and at the theory level (exported and
  5237 qualified by the locale name);
  5238 
  5239 * Pure: theory goals may now be specified in ``long'' form, with
  5240 ad-hoc contexts consisting of arbitrary locale elements. for example
  5241 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5242 definitions may be given, too); the result is a meta-level rule with
  5243 the context elements being discharged in the obvious way;
  5244 
  5245 * Pure: new proof command 'using' allows to augment currently used
  5246 facts after a goal statement ('using' is syntactically analogous to
  5247 'apply', but acts on the goal's facts only); this allows chained facts
  5248 to be separated into parts given before and after a claim, as in
  5249 ``from a and b have C using d and e <proof>'';
  5250 
  5251 * Pure: renamed "antecedent" case to "rule_context";
  5252 
  5253 * Pure: new 'judgment' command records explicit information about the
  5254 object-logic embedding (used by several tools internally); no longer
  5255 use hard-wired "Trueprop";
  5256 
  5257 * Pure: added 'corollary' command;
  5258 
  5259 * Pure: fixed 'token_translation' command;
  5260 
  5261 * Pure: removed obsolete 'exported' attribute;
  5262 
  5263 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5264 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5265 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5266 
  5267 * Pure: method 'atomize' presents local goal premises as object-level
  5268 statements (atomic meta-level propositions); setup controlled via
  5269 rewrite rules declarations of 'atomize' attribute; example
  5270 application: 'induct' method with proper rule statements in improper
  5271 proof *scripts*;
  5272 
  5273 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5274 now consider the syntactic context of assumptions, giving a better
  5275 chance to get type-inference of the arguments right (this is
  5276 especially important for locales);
  5277 
  5278 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5279 mode;
  5280 
  5281 * Pure/obtain: the formal conclusion "thesis", being marked as
  5282 ``internal'', may no longer be reference directly in the text;
  5283 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5284 situations;
  5285 
  5286 * Pure: generic 'sym' attribute which declares a rule both as pure
  5287 'elim?' and for the 'symmetric' operation;
  5288 
  5289 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5290 text; the fixed correlation with particular command syntax has been
  5291 discontinued;
  5292 
  5293 * Pure: new method 'rules' is particularly well-suited for proof
  5294 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5295 but often produces more compact proof terms with less detours;
  5296 
  5297 * Pure/Provers/classical: simplified integration with pure rule
  5298 attributes and methods; the classical "intro?/elim?/dest?"
  5299 declarations coincide with the pure ones; the "rule" method no longer
  5300 includes classically swapped intros; "intro" and "elim" methods no
  5301 longer pick rules from the context; also got rid of ML declarations
  5302 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5303 INCOMPATIBILITY;
  5304 
  5305 * Provers/classical: attribute 'swapped' produces classical inversions
  5306 of introduction rules;
  5307 
  5308 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5309 rules instead of full simplifier context; 'iff' attribute handles
  5310 conditional rules;
  5311 
  5312 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5313 
  5314 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5315 "(permissive)" option to recover old behavior;
  5316 
  5317 * HOL: 'inductive' no longer features separate (collective) attributes
  5318 for 'intros' (was found too confusing);
  5319 
  5320 * HOL: properly declared induction rules less_induct and
  5321 wf_induct_rule;
  5322 
  5323 
  5324 *** HOL ***
  5325 
  5326 * HOL: moved over to sane numeral syntax; the new policy is as
  5327 follows:
  5328 
  5329   - 0 and 1 are polymorphic constants, which are defined on any
  5330   numeric type (nat, int, real etc.);
  5331 
  5332   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5333   binary representation internally;
  5334 
  5335   - type nat has special constructor Suc, and generally prefers Suc 0
  5336   over 1::nat and Suc (Suc 0) over 2::nat;
  5337 
  5338 This change may cause significant problems of INCOMPATIBILITY; here
  5339 are some hints on converting existing sources:
  5340 
  5341   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5342   entities, so expressions involving "-" (unary or binary minus) need
  5343   to be spaced properly;
  5344 
  5345   - existing occurrences of "1" may need to be constraint "1::nat" or
  5346   even replaced by Suc 0; similar for old "2";
  5347 
  5348   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5349 
  5350   - remove all special provisions on numerals in proofs;
  5351 
  5352 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5353 representation (depends on bin_arith_simps in the default context);
  5354 
  5355 * HOL: symbolic syntax for x^2 (numeral 2);
  5356 
  5357 * HOL: the class of all HOL types is now called "type" rather than
  5358 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5359 in axclass/classes, instance/arities, and (usually rare) occurrences
  5360 in typings (of consts etc.); internally the class is called
  5361 "HOL.type", ML programs should refer to HOLogic.typeS;
  5362 
  5363 * HOL/record package improvements:
  5364   - new derived operations "fields" to build a partial record section,
  5365     "extend" to promote a fixed record to a record scheme, and
  5366     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5367     declared as simp by default;
  5368   - shared operations ("more", "fields", etc.) now need to be always
  5369     qualified) --- potential INCOMPATIBILITY;
  5370   - removed "make_scheme" operations (use "make" with "extend") --
  5371     INCOMPATIBILITY;
  5372   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5373   - provides cases/induct rules for use with corresponding Isar
  5374     methods (for concrete records, record schemes, concrete more
  5375     parts, and schematic more parts -- in that order);
  5376   - internal definitions directly based on a light-weight abstract
  5377     theory of product types over typedef rather than datatype;
  5378 
  5379 * HOL: generic code generator for generating executable ML code from
  5380 specifications; specific support for HOL constructs such as inductive
  5381 datatypes and sets, as well as recursive functions; can be invoked
  5382 via 'generate_code' theory section;
  5383 
  5384 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5385 
  5386 * HOL: consolidated and renamed several theories.  In particular:
  5387         Ord.thy has been absorbed into HOL.thy
  5388         String.thy has been absorbed into List.thy
  5389 
  5390 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5391 (beware of argument permutation!);
  5392 
  5393 * HOL: linorder_less_split superseded by linorder_cases;
  5394 
  5395 * HOL/List: "nodups" renamed to "distinct";
  5396 
  5397 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5398 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5399   - Ex_def has changed, now need to use some_eq_ex
  5400 
  5401 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5402 in this (rare) case use:
  5403 
  5404   delSWrapper "split_all_tac"
  5405   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5406 
  5407 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5408 MAY FAIL;
  5409 
  5410 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5411 Isabelle's type classes, ^ on functions and relations has too general
  5412 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5413 necessary to attach explicit type constraints;
  5414 
  5415 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5416 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5417 renamed accordingly (eg "compI" -> "rel_compI").
  5418 
  5419 * HOL: syntax translations now work properly with numerals and records
  5420 expressions;
  5421 
  5422 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5423 of "lam" -- INCOMPATIBILITY;
  5424 
  5425 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5426 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5427 renamed "Product_Type.unit";
  5428 
  5429 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5430 
  5431 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5432 the "cases" method);
  5433 
  5434 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5435 Florian Kammller);
  5436 
  5437 * HOL/IMP: updated and converted to new-style theory format; several
  5438 parts turned into readable document, with proper Isar proof texts and
  5439 some explanations (by Gerwin Klein);
  5440 
  5441 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5442 
  5443 * HOL-Hyperreal is now a logic image;
  5444 
  5445 
  5446 *** HOLCF ***
  5447 
  5448 * Isar: consts/constdefs supports mixfix syntax for continuous
  5449 operations;
  5450 
  5451 * Isar: domain package adapted to new-style theory format, e.g. see
  5452 HOLCF/ex/Dnat.thy;
  5453 
  5454 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5455 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5456 lift.induct_tac, always use UU instead of Undef;
  5457 
  5458 * HOLCF/IMP: updated and converted to new-style theory;
  5459 
  5460 
  5461 *** ZF ***
  5462 
  5463 * Isar: proper integration of logic-specific tools and packages,
  5464 including theory commands '(co)inductive', '(co)datatype',
  5465 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5466 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5467 
  5468 * theory Main no longer includes AC; for the Axiom of Choice, base
  5469 your theory on Main_ZFC;
  5470 
  5471 * the integer library now covers quotients and remainders, with many
  5472 laws relating division to addition, multiplication, etc.;
  5473 
  5474 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5475 typeless version of the formalism;
  5476 
  5477 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5478 format;
  5479 
  5480 * ZF/Induct: new directory for examples of inductive definitions,
  5481 including theory Multiset for multiset orderings; converted to
  5482 new-style theory format;
  5483 
  5484 * ZF: many new theorems about lists, ordinals, etc.;
  5485 
  5486 
  5487 *** General ***
  5488 
  5489 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5490 variable proof controls level of detail: 0 = no proofs (only oracle
  5491 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5492 also ref manual for further ML interfaces;
  5493 
  5494 * Pure/axclass: removed obsolete ML interface
  5495 goal_subclass/goal_arity;
  5496 
  5497 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5498 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5499 separate tokens, so expressions involving minus need to be spaced
  5500 properly;
  5501 
  5502 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5503 rather than "infixl" or "infixr";
  5504 
  5505 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5506 sort constraint specifications in type inference; e.g. "x::_::foo"
  5507 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5508 type variable);
  5509 
  5510 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5511 control output of nested => (types); the default behavior is
  5512 "type_brackets";
  5513 
  5514 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5515 tokens into AST constants;
  5516 
  5517 * Pure/syntax: prefer later declarations of translations and print
  5518 translation functions; potential INCOMPATIBILITY: need to reverse
  5519 multiple declarations for same syntax element constant;
  5520 
  5521 * Pure/show_hyps reset by default (in accordance to existing Isar
  5522 practice);
  5523 
  5524 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5525 addSafter;
  5526 
  5527 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5528 as well;
  5529 
  5530 * system: tested support for MacOS X; should be able to get Isabelle +
  5531 Proof General to work in a plain Terminal after installing Poly/ML
  5532 (e.g. from the Isabelle distribution area) and GNU bash alone
  5533 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5534 support requires further installations, e.g. from
  5535 http://fink.sourceforge.net/);
  5536 
  5537 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5538 
  5539 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5540 of 40 MB), cf. ML_OPTIONS;
  5541 
  5542 * system: Proof General keywords specification is now part of the
  5543 Isabelle distribution (see etc/isar-keywords.el);
  5544 
  5545 * system: support for persistent Proof General sessions (refrain from
  5546 outdating all loaded theories on startup); user may create writable
  5547 logic images like this: ``isabelle -q HOL Test'';
  5548 
  5549 * system: smart selection of Isabelle process versus Isabelle
  5550 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5551 run both "isabelle" and "Isabelle" even if file names are badly
  5552 damaged (executable inspects the case of the first letter of its own
  5553 name); added separate "isabelle-process" and "isabelle-interface";
  5554 
  5555 * system: refrain from any attempt at filtering input streams; no
  5556 longer support ``8bit'' encoding of old isabelle font, instead proper
  5557 iso-latin characters may now be used; the related isatools
  5558 "symbolinput" and "nonascii" have disappeared as well;
  5559 
  5560 * system: removed old "xterm" interface (the print modes "xterm" and
  5561 "xterm_color" are still available for direct use in a suitable
  5562 terminal);
  5563 
  5564 
  5565 
  5566 New in Isabelle99-2 (February 2001)
  5567 -----------------------------------
  5568 
  5569 *** Overview of INCOMPATIBILITIES ***
  5570 
  5571 * HOL: please note that theories in the Library and elsewhere often use the
  5572 new-style (Isar) format; to refer to their theorems in an ML script you must
  5573 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5574 
  5575 * HOL: inductive package no longer splits induction rule aggressively,
  5576 but only as far as specified by the introductions given; the old
  5577 format may be recovered via ML function complete_split_rule or attribute
  5578 'split_rule (complete)';
  5579 
  5580 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5581 gfp_Tarski to gfp_unfold;
  5582 
  5583 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5584 
  5585 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5586 relation); infix "^^" has been renamed "``"; infix "``" has been
  5587 renamed "`"; "univalent" has been renamed "single_valued";
  5588 
  5589 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5590 operation;
  5591 
  5592 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5593 
  5594 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5595 
  5596 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5597 consequence, it is no longer monotonic wrt. the local goal context
  5598 (which is now passed through the inductive cases);
  5599 
  5600 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5601 \<gg> to \<ggreater>;
  5602 
  5603 
  5604 *** Document preparation ***
  5605 
  5606 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5607 available: are "it" for near math-mode best-style output, "sl" for
  5608 slanted text style, and "tt" for plain type-writer; if no
  5609 \isabellestyle command is given, output is according to slanted
  5610 type-writer);
  5611 
  5612 * support sub/super scripts (for single symbols only), input syntax is
  5613 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5614 
  5615 * some more standard symbols; see Appendix A of the system manual for
  5616 the complete list of symbols defined in isabellesym.sty;
  5617 
  5618 * improved isabelle style files; more abstract symbol implementation
  5619 (should now use \isamath{...} and \isatext{...} in custom symbol
  5620 definitions);
  5621 
  5622 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5623 state; Note that presentation of goal states does not conform to
  5624 actual human-readable proof documents.  Please do not include goal
  5625 states into document output unless you really know what you are doing!
  5626 
  5627 * proper indentation of antiquoted output with proportional LaTeX
  5628 fonts;
  5629 
  5630 * no_document ML operator temporarily disables LaTeX document
  5631 generation;
  5632 
  5633 * isatool unsymbolize tunes sources for plain ASCII communication;
  5634 
  5635 
  5636 *** Isar ***
  5637 
  5638 * Pure: Isar now suffers initial goal statements to contain unbound
  5639 schematic variables (this does not conform to actual readable proof
  5640 documents, due to unpredictable outcome and non-compositional proof
  5641 checking); users who know what they are doing may use schematic goals
  5642 for Prolog-style synthesis of proven results;
  5643 
  5644 * Pure: assumption method (an implicit finishing) now handles actual
  5645 rules as well;
  5646 
  5647 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5648 initial goal, declare "that" only as Pure intro (only for single
  5649 steps); the "that" rule assumption may now be involved in implicit
  5650 finishing, thus ".." becomes a feasible for trivial obtains;
  5651 
  5652 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5653 instance proofs may be performed by "..";
  5654 
  5655 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5656 statements as well;
  5657 
  5658 * Pure: more robust selection of calculational rules;
  5659 
  5660 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5661 rule (as well as the assumption rule);
  5662 
  5663 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5664 lemmas, using the graph browser tool;
  5665 
  5666 * Pure: predict failure of "show" in interactive mode;
  5667 
  5668 * Pure: 'thms_containing' now takes actual terms as arguments;
  5669 
  5670 * HOL: improved method 'induct' --- now handles non-atomic goals
  5671 (potential INCOMPATIBILITY); tuned error handling;
  5672 
  5673 * HOL: cases and induct rules now provide explicit hints about the
  5674 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5675 any remaining facts are inserted into the goal verbatim;
  5676 
  5677 * HOL: local contexts (aka cases) may now contain term bindings as
  5678 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5679 the result to be shown in each case;
  5680 
  5681 * HOL: added 'recdef_tc' command;
  5682 
  5683 * isatool convert assists in eliminating legacy ML scripts;
  5684 
  5685 
  5686 *** HOL ***
  5687 
  5688 * HOL/Library: a collection of generic theories to be used together
  5689 with main HOL; the theory loader path already includes this directory
  5690 by default; the following existing theories have been moved here:
  5691 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5692 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5693 
  5694 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5695 modelling and verification task performed in Isabelle/HOL +
  5696 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5697 
  5698 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5699 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5700 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5701 'domain', this makes the theory consistent with mathematical
  5702 literature;
  5703 
  5704 * HOL basics: added overloaded operations "inverse" and "divide"
  5705 (infix "/"), syntax for generic "abs" operation, generic summation
  5706 operator \<Sum>;
  5707 
  5708 * HOL/typedef: simplified package, provide more useful rules (see also
  5709 HOL/subset.thy);
  5710 
  5711 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5712 now expressed as a proper nested rule (old-style tactic scripts may
  5713 require atomize_strip_tac to cope with non-atomic premises);
  5714 
  5715 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5716 to "split_conv" (old name still available for compatibility);
  5717 
  5718 * HOL: improved concrete syntax for strings (e.g. allows translation
  5719 rules with string literals);
  5720 
  5721 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5722  and Fleuriot's mechanization of analysis, including the transcendental
  5723  functions for the reals;
  5724 
  5725 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5726 
  5727 
  5728 *** CTT ***
  5729 
  5730 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5731 "lam" is displayed as TWO lambda-symbols
  5732 
  5733 * CTT: theory Main now available, containing everything (that is, Bool
  5734 and Arith);
  5735 
  5736 
  5737 *** General ***
  5738 
  5739 * Pure: the Simplifier has been implemented properly as a derived rule
  5740 outside of the actual kernel (at last!); the overall performance
  5741 penalty in practical applications is about 50%, while reliability of
  5742 the Isabelle inference kernel has been greatly improved;
  5743 
  5744 * print modes "brackets" and "no_brackets" control output of nested =>
  5745 (types) and ==> (props); the default behaviour is "brackets";
  5746 
  5747 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5748 as assumptions as well;
  5749 
  5750 * system: support Poly/ML 4.0;
  5751 
  5752 * system: isatool install handles KDE version 1 or 2;
  5753 
  5754 
  5755 
  5756 New in Isabelle99-1 (October 2000)
  5757 ----------------------------------
  5758 
  5759 *** Overview of INCOMPATIBILITIES ***
  5760 
  5761 * HOL: simplification of natural numbers is much changed; to partly
  5762 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5763 issue the following ML commands:
  5764 
  5765   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5766   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5767 
  5768 * HOL: simplification no longer dives into case-expressions; this is
  5769 controlled by "t.weak_case_cong" for each datatype t;
  5770 
  5771 * HOL: nat_less_induct renamed to less_induct;
  5772 
  5773 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5774 fixsome to patch .thy and .ML sources automatically;
  5775 
  5776   select_equality  -> some_equality
  5777   select_eq_Ex     -> some_eq_ex
  5778   selectI2EX       -> someI2_ex
  5779   selectI2         -> someI2
  5780   selectI          -> someI
  5781   select1_equality -> some1_equality
  5782   Eps_sym_eq       -> some_sym_eq_trivial
  5783   Eps_eq           -> some_eq_trivial
  5784 
  5785 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5786 
  5787 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5788 instead);
  5789 
  5790 * HOL: the recursion equations generated by 'recdef' are now called
  5791 f.simps instead of f.rules;
  5792 
  5793 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5794 
  5795 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5796 sometimes be needed;
  5797 
  5798 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5799 
  5800 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5801 
  5802 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5803 product is now "<*>" instead of "Times"; the lexicographic product is
  5804 now "<*lex*>" instead of "**";
  5805 
  5806 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5807 of main HOL, but was unused); better use HOL's datatype package;
  5808 
  5809 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5810 the old syntax may be recovered as follows:
  5811 
  5812   syntax (symbols)
  5813     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5814       (infixl "\\<oplus>" 100)
  5815 
  5816 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5817 
  5818 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5819 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5820 internally;
  5821 
  5822 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5823 changed from A/r to A//r;
  5824 
  5825 * ZF: new treatment of arithmetic (nat & int) may break some old
  5826 proofs;
  5827 
  5828 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5829 rulify -> rule_format, elimify -> elim_format, ...);
  5830 
  5831 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5832 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5833 should have to change intro!! to intro? only); replaced "delrule" by
  5834 "rule del";
  5835 
  5836 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5837 
  5838 * Provers: strengthened force_tac by using new first_best_tac;
  5839 
  5840 * LaTeX document preparation: several changes of isabelle.sty (see
  5841 lib/texinputs);
  5842 
  5843 
  5844 *** Document preparation ***
  5845 
  5846 * formal comments (text blocks etc.) in new-style theories may now
  5847 contain antiquotations of thm/prop/term/typ/text to be presented
  5848 according to latex print mode; concrete syntax is like this:
  5849 @{term[show_types] "f(x) = a + x"};
  5850 
  5851 * isatool mkdir provides easy setup of Isabelle session directories,
  5852 including proper document sources;
  5853 
  5854 * generated LaTeX sources are now deleted after successful run
  5855 (isatool document -c); may retain a copy somewhere else via -D option
  5856 of isatool usedir;
  5857 
  5858 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5859 style files, achieving self-contained LaTeX sources and simplifying
  5860 LaTeX debugging;
  5861 
  5862 * old-style theories now produce (crude) LaTeX output as well;
  5863 
  5864 * browser info session directories are now self-contained (may be put
  5865 on WWW server seperately); improved graphs of nested sessions; removed
  5866 graph for 'all sessions';
  5867 
  5868 * several improvements in isabelle style files; \isabellestyle{it}
  5869 produces fake math mode output; \isamarkupheader is now \section by
  5870 default; see lib/texinputs/isabelle.sty etc.;
  5871 
  5872 
  5873 *** Isar ***
  5874 
  5875 * Isar/Pure: local results and corresponding term bindings are now
  5876 subject to Hindley-Milner polymorphism (similar to ML); this
  5877 accommodates incremental type-inference very nicely;
  5878 
  5879 * Isar/Pure: new derived language element 'obtain' supports
  5880 generalized existence reasoning;
  5881 
  5882 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5883 support accumulation of results, without applying any rules yet;
  5884 useful to collect intermediate results without explicit name
  5885 references, and for use with transitivity rules with more than 2
  5886 premises;
  5887 
  5888 * Isar/Pure: scalable support for case-analysis type proofs: new
  5889 'case' language element refers to local contexts symbolically, as
  5890 produced by certain proof methods; internally, case names are attached
  5891 to theorems as "tags";
  5892 
  5893 * Isar/Pure: theory command 'hide' removes declarations from
  5894 class/type/const name spaces;
  5895 
  5896 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5897 indicate potential overloading;
  5898 
  5899 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5900 
  5901 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5902 "{a,b,c}" instead of {a,b,c};
  5903 
  5904 * Isar/Pure now provides its own version of intro/elim/dest
  5905 attributes; useful for building new logics, but beware of confusion
  5906 with the version in Provers/classical;
  5907 
  5908 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5909 case name 'antecedent';
  5910 
  5911 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5912 to the current context is now done automatically);
  5913 
  5914 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5915 for definining proof methods in ML;
  5916 
  5917 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5918 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5919 most cases, one should have to change intro!! to intro? only);
  5920 replaced "delrule" by "rule del";
  5921 
  5922 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5923 'symmetric' attribute (the latter supercedes [RS sym]);
  5924 
  5925 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5926 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5927 well (including splits);
  5928 
  5929 * Isar/Provers: Simplifier and Classical methods now support all kind
  5930 of modifiers used in the past, including 'cong', 'iff', etc.
  5931 
  5932 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5933 of Simplifier and Classical reasoner);
  5934 
  5935 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5936 now support named cases; major packages (inductive, datatype, primrec,
  5937 recdef) support case names and properly name parameters;
  5938 
  5939 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5940 monotonicity conditions are extracted to be proven at end of
  5941 calculations;
  5942 
  5943 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5944 method anyway;
  5945 
  5946 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5947 split_if split_if_asm; datatype package provides theorems foo.splits =
  5948 foo.split foo.split_asm for each datatype;
  5949 
  5950 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5951 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5952 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5953 use "(cases (simplified))" method in proper proof texts);
  5954 
  5955 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5956 
  5957 * Isar: names of theorems etc. may be natural numbers as well;
  5958 
  5959 * Isar: 'pr' command: optional arguments for goals_limit and
  5960 ProofContext.prems_limit; no longer prints theory contexts, but only
  5961 proof states;
  5962 
  5963 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5964 additional print modes to be specified; e.g. "pr(latex)" will print
  5965 proof state according to the Isabelle LaTeX style;
  5966 
  5967 * Isar: improved support for emulating tactic scripts, including proof
  5968 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5969 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5970 (for HOL datatypes);
  5971 
  5972 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5973 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5974 'proof method scripts' have to be in depth-first order;
  5975 
  5976 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5977 
  5978 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5979 should instead use individual commands for printing items
  5980 (print_commands, print_methods etc.);
  5981 
  5982 * Isar: added 'nothing' --- the empty list of theorems;
  5983 
  5984 
  5985 *** HOL ***
  5986 
  5987 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5988 corresponding virtual machine and a specification of its bytecode
  5989 verifier and a lightweight bytecode verifier, including proofs of
  5990 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5991 Cornelia Pusch (see also the homepage of project Bali at
  5992 http://isabelle.in.tum.de/Bali/);
  5993 
  5994 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5995 Clemens Ballarin;
  5996 
  5997 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5998 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5999 Rasmussen;
  6000 
  6001 * HOL/Lattice: fundamental concepts of lattice theory and order
  6002 structures, including duals, properties of bounds versus algebraic
  6003 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6004 Theorem for complete lattices etc.; may also serve as a demonstration
  6005 for abstract algebraic reasoning using axiomatic type classes, and
  6006 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6007 
  6008 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6009 von Oheimb;
  6010 
  6011 * HOL/IMPP: extension of IMP with local variables and mutually
  6012 recursive procedures, by David von Oheimb;
  6013 
  6014 * HOL/Lambda: converted into new-style theory and document;
  6015 
  6016 * HOL/ex/Multiquote: example of multiple nested quotations and
  6017 anti-quotations -- basically a generalized version of de-Bruijn
  6018 representation; very useful in avoiding lifting of operations;
  6019 
  6020 * HOL/record: added general record equality rule to simpset; fixed
  6021 select-update simplification procedure to handle extended records as
  6022 well; admit "r" as field name;
  6023 
  6024 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6025 other numeric types and also as the identity of groups, rings, etc.;
  6026 
  6027 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6028 Types nat and int belong to this axclass;
  6029 
  6030 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6031    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6032    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6033   two terms #m*u and #n*u are replaced by #(m+n)*u
  6034     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6035   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6036     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6037 
  6038 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6039 powerful prover for predicate logic but knows nothing of clasets; see
  6040 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6041 
  6042 * HOL: new version of "case_tac" subsumes both boolean case split and
  6043 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6044 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6045 
  6046 * HOL: simplification no longer dives into case-expressions: only the
  6047 selector expression is simplified, but not the remaining arms; to
  6048 enable full simplification of case-expressions for datatype t, you may
  6049 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6050 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6051 
  6052 * HOL/recdef: the recursion equations generated by 'recdef' for
  6053 function 'f' are now called f.simps instead of f.rules; if all
  6054 termination conditions are proved automatically, these simplification
  6055 rules are added to the simpset, as in primrec; rules may be named
  6056 individually as well, resulting in a separate list of theorems for
  6057 each equation;
  6058 
  6059 * HOL/While is a new theory that provides a while-combinator. It
  6060 permits the definition of tail-recursive functions without the
  6061 provision of a termination measure. The latter is necessary once the
  6062 invariant proof rule for while is applied.
  6063 
  6064 * HOL: new (overloaded) notation for the set of elements below/above
  6065 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6066 
  6067 * HOL: theorems impI, allI, ballI bound as "strip";
  6068 
  6069 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6070 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6071 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6072 
  6073 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6074 
  6075 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6076 main HOL, but was unused);
  6077 
  6078 * HOL: fewer consts declared as global (e.g. have to refer to
  6079 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6080 
  6081 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6082 in case of overlap with user translations (e.g. judgements over
  6083 tuples); (note that the underlying logical represenation is still
  6084 bogus);
  6085 
  6086 
  6087 *** ZF ***
  6088 
  6089 * ZF: simplification automatically cancels common terms in arithmetic
  6090 expressions over nat and int;
  6091 
  6092 * ZF: new treatment of nat to minimize type-checking: all operators
  6093 coerce their operands to a natural number using the function natify,
  6094 making the algebraic laws unconditional;
  6095 
  6096 * ZF: as above, for int: operators coerce their operands to an integer
  6097 using the function intify;
  6098 
  6099 * ZF: the integer library now contains many of the usual laws for the
  6100 orderings, including $<=, and monotonicity laws for $+ and $*;
  6101 
  6102 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6103 simplification;
  6104 
  6105 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6106 to the simplifier and classical reasoner simultaneously;
  6107 
  6108 
  6109 *** General ***
  6110 
  6111 * Provers: blast_tac now handles actual object-logic rules as
  6112 assumptions; note that auto_tac uses blast_tac internally as well;
  6113 
  6114 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6115 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6116 
  6117 * Provers: delrules now handles destruct rules as well (no longer need
  6118 explicit make_elim);
  6119 
  6120 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6121   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6122 use instead the strong form,
  6123   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6124 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6125 from destruct-rules;
  6126 
  6127 * Provers: Simplifier.easy_setup provides a fast path to basic
  6128 Simplifier setup for new object-logics;
  6129 
  6130 * Pure: AST translation rules no longer require constant head on LHS;
  6131 
  6132 * Pure: improved name spaces: ambiguous output is qualified; support
  6133 for hiding of names;
  6134 
  6135 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6136 XSYMBOL_HOME; no longer need to do manual configuration in most
  6137 situations;
  6138 
  6139 * system: compression of ML heaps images may now be controlled via -c
  6140 option of isabelle and isatool usedir (currently only observed by
  6141 Poly/ML);
  6142 
  6143 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6144 useful for remote X11);
  6145 
  6146 * system: provide TAGS file for Isabelle sources;
  6147 
  6148 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6149 order;
  6150 
  6151 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6152 timing flag supersedes proof_timing and Toplevel.trace;
  6153 
  6154 * ML: new combinators |>> and |>>> for incremental transformations
  6155 with secondary results (e.g. certain theory extensions):
  6156 
  6157 * ML: PureThy.add_defs gets additional argument to indicate potential
  6158 overloading (usually false);
  6159 
  6160 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6161 results;
  6162 
  6163 
  6164 
  6165 New in Isabelle99 (October 1999)
  6166 --------------------------------
  6167 
  6168 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6169 
  6170 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6171 are no longer simplified.  (This allows the simplifier to unfold recursive
  6172 functional programs.)  To restore the old behaviour, declare
  6173 
  6174     Delcongs [if_weak_cong];
  6175 
  6176 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6177 complement;
  6178 
  6179 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6180 
  6181 * HOL/datatype: mutual_induct_tac no longer exists --
  6182   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6183 
  6184 * HOL/typedef: fixed type inference for representing set; type
  6185 arguments now have to occur explicitly on the rhs as type constraints;
  6186 
  6187 * ZF: The con_defs part of an inductive definition may no longer refer
  6188 to constants declared in the same theory;
  6189 
  6190 * HOL, ZF: the function mk_cases, generated by the inductive
  6191 definition package, has lost an argument.  To simplify its result, it
  6192 uses the default simpset instead of a supplied list of theorems.
  6193 
  6194 * HOL/List: the constructors of type list are now Nil and Cons;
  6195 
  6196 * Simplifier: the type of the infix ML functions
  6197         setSSolver addSSolver setSolver addSolver
  6198 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6199 for packaging solvers. A solver is created via
  6200         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6201 where the string argument is only a comment.
  6202 
  6203 
  6204 *** Proof tools ***
  6205 
  6206 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6207 decision procedure for linear arithmetic. Currently it is used for
  6208 types `nat', `int', and `real' in HOL (see below); it can, should and
  6209 will be instantiated for other types and logics as well.
  6210 
  6211 * The simplifier now accepts rewrite rules with flexible heads, eg
  6212      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6213   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6214   matching.
  6215 
  6216 
  6217 *** General ***
  6218 
  6219 * New Isabelle/Isar subsystem provides an alternative to traditional
  6220 tactical theorem proving; together with the ProofGeneral/isar user
  6221 interface it offers an interactive environment for developing human
  6222 readable proof documents (Isar == Intelligible semi-automated
  6223 reasoning); for further information see isatool doc isar-ref,
  6224 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6225 
  6226 * improved and simplified presentation of theories: better HTML markup
  6227 (including colors), graph views in several sizes; isatool usedir now
  6228 provides a proper interface for user theories (via -P option); actual
  6229 document preparation based on (PDF)LaTeX is available as well (for
  6230 new-style theories only); see isatool doc system for more information;