NEWS
author haftmann
Wed Aug 11 14:31:40 2010 +0200 (2010-08-11)
changeset 38347 19000bb11ff5
parent 38135 2b9bfa0b44f1
child 38461 75fc4087764e
permissions -rw-r--r--
NEWS
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    10 a Unicode character is treated as a single symbol, not a sequence of
    11 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    12 contain symbols without further backslash escapes, Unicode can now be
    13 used here as well.  Recall that Symbol.explode in ML provides a
    14 consistent view on symbols, while raw explode (or String.explode)
    15 merely give a byte-oriented representation.
    16 
    17 * Theory loading: only the master source file is looked-up in the
    18 implicit load path, all other files are addressed relatively to its
    19 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    20 
    21 * Special treatment of ML file names has been discontinued.
    22 Historically, optional extensions .ML or .sml were added on demand --
    23 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    24 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    25 
    26 
    27 *** Pure ***
    28 
    29 * Interpretation command 'interpret' accepts a list of equations like
    30 'interpretation' does.
    31 
    32 * Diagnostic command 'print_interps' prints interpretations in proofs
    33 in addition to interpretations in theories.
    34 
    35 
    36 *** HOL ***
    37 
    38 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    39 in Library/State_Monad has been changed to avoid ambiguities.
    40 INCOMPATIBILITY.
    41 
    42 * code generator: export_code without explicit file declaration prints
    43 to standard output.  INCOMPATIBILITY.
    44 
    45 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
    46 respectively.  INCOMPATIBILITY.
    47 
    48 * Constant "split" has been merged with constant "prod_case";  names
    49 of ML functions, facts etc. involving split have been retained so far,
    50 though.  INCOMPATIBILITY.
    51 
    52 * Dropped old infix syntax "mem" for List.member;  use "in set"
    53 instead.  INCOMPATIBILITY.
    54 
    55 * Refactoring of code-generation specific operations in List.thy
    56 
    57   constants
    58     null ~> List.null
    59 
    60   facts
    61     mem_iff ~> member_def
    62     null_empty ~> null_def
    63 
    64 INCOMPATIBILITY.  Note that these were not suppossed to be used
    65 regularly unless for striking reasons;  their main purpose was code
    66 generation.
    67 
    68 * Some previously unqualified names have been qualified:
    69 
    70   types
    71     nat ~> Nat.nat
    72 
    73   constants
    74     Ball ~> Set.Ball
    75     Bex ~> Set.Bex
    76     Suc ~> Nat.Suc
    77     Pair ~> Product_Type.Pair
    78     fst ~> Product_Type.fst
    79     snd ~> Product_Type.snd
    80     curry ~> Product_Type.curry
    81     op : ~> Set.member
    82     Collect ~> Set.Collect
    83 
    84 INCOMPATIBILITY.
    85 
    86 * Removed simplifier congruence rule of "prod_case", as has for long
    87 been the case with "split".
    88 
    89 * Datatype package: theorems generated for executable equality
    90 (class eq) carry proper names and are treated as default code
    91 equations.
    92 
    93 * List.thy: use various operations from the Haskell prelude when
    94 generating Haskell code.
    95 
    96 * code_simp.ML: simplification with rules determined by
    97 code generator.
    98 
    99 * code generator: do not print function definitions for case
   100 combinators any longer.
   101 
   102 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   103 theorems are now stated in terms of euclidean spaces instead of finite
   104 cartesian products.
   105 
   106   types
   107     real ^ 'n ~>  'a::real_vector
   108               ~>  'a::euclidean_space
   109               ~>  'a::ordered_euclidean_space
   110         (depends on your needs)
   111 
   112   constants
   113      _ $ _        ~> _ $$ _
   114      \<chi> x. _  ~> \<chi>\<chi> x. _
   115      CARD('n)     ~> DIM('a)
   116 
   117 Also note that the indices are now natural numbers and not from some finite
   118 type. Finite cartesian products of euclidean spaces, products of euclidean
   119 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   120 
   121 INCOMPATIBILITY.
   122 
   123 * Inductive package: offers new command "inductive_simps" to automatically
   124   derive instantiated and simplified equations for inductive predicates,
   125   similar to inductive_cases.
   126 
   127 
   128 *** ML ***
   129 
   130 * ML antiquotations @{theory} and @{theory_ref} refer to named
   131 theories from the ancestry of the current context, not any accidental
   132 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   133 change in semantics.
   134 
   135 
   136 
   137 New in Isabelle2009-2 (June 2010)
   138 ---------------------------------
   139 
   140 *** General ***
   141 
   142 * Authentic syntax for *all* logical entities (type classes, type
   143 constructors, term constants): provides simple and robust
   144 correspondence between formal entities and concrete syntax.  Within
   145 the parse tree / AST representations, "constants" are decorated by
   146 their category (class, type, const) and spelled out explicitly with
   147 their full internal name.
   148 
   149 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   150 and translations (translation rules and translation functions in ML).
   151 Some hints on upgrading:
   152 
   153   - Many existing uses of 'syntax' and 'translations' can be replaced
   154     by more modern 'type_notation', 'notation' and 'abbreviation',
   155     which are independent of this issue.
   156 
   157   - 'translations' require markup within the AST; the term syntax
   158     provides the following special forms:
   159 
   160       CONST c   -- produces syntax version of constant c from context
   161       XCONST c  -- literally c, checked as constant from context
   162       c         -- literally c, if declared by 'syntax'
   163 
   164     Plain identifiers are treated as AST variables -- occasionally the
   165     system indicates accidental variables via the error "rhs contains
   166     extra variables".
   167 
   168     Type classes and type constructors are marked according to their
   169     concrete syntax.  Some old translations rules need to be written
   170     for the "type" category, using type constructor application
   171     instead of pseudo-term application of the default category
   172     "logic".
   173 
   174   - 'parse_translation' etc. in ML may use the following
   175     antiquotations:
   176 
   177       @{class_syntax c}   -- type class c within parse tree / AST
   178       @{term_syntax c}    -- type constructor c within parse tree / AST
   179       @{const_syntax c}   -- ML version of "CONST c" above
   180       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   181 
   182   - Literal types within 'typed_print_translations', i.e. those *not*
   183     represented as pseudo-terms are represented verbatim.  Use @{class
   184     c} or @{type_name c} here instead of the above syntax
   185     antiquotations.
   186 
   187 Note that old non-authentic syntax was based on unqualified base
   188 names, so all of the above "constant" names would coincide.  Recall
   189 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   190 diagnose syntax problems.
   191 
   192 * Type constructors admit general mixfix syntax, not just infix.
   193 
   194 * Concrete syntax may be attached to local entities without a proof
   195 body, too.  This works via regular mixfix annotations for 'fix',
   196 'def', 'obtain' etc. or via the explicit 'write' command, which is
   197 similar to the 'notation' command in theory specifications.
   198 
   199 * Discontinued unnamed infix syntax (legacy feature for many years) --
   200 need to specify constant name and syntax separately.  Internal ML
   201 datatype constructors have been renamed from InfixName to Infix etc.
   202 Minor INCOMPATIBILITY.
   203 
   204 * Schematic theorem statements need to be explicitly markup as such,
   205 via commands 'schematic_lemma', 'schematic_theorem',
   206 'schematic_corollary'.  Thus the relevance of the proof is made
   207 syntactically clear, which impacts performance in a parallel or
   208 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   209 
   210 * Use of cumulative prems via "!" in some proof methods has been
   211 discontinued (old legacy feature).
   212 
   213 * References 'trace_simp' and 'debug_simp' have been replaced by
   214 configuration options stored in the context. Enabling tracing (the
   215 case of debugging is similar) in proofs works via
   216 
   217   using [[trace_simp = true]]
   218 
   219 Tracing is then active for all invocations of the simplifier in
   220 subsequent goal refinement steps. Tracing may also still be enabled or
   221 disabled via the ProofGeneral settings menu.
   222 
   223 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   224 'hide_fact' replace the former 'hide' KIND command.  Minor
   225 INCOMPATIBILITY.
   226 
   227 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   228 more efficient than combinations with -q1 or -q2.
   229 
   230 
   231 *** Pure ***
   232 
   233 * Proofterms record type-class reasoning explicitly, using the
   234 "unconstrain" operation internally.  This eliminates all sort
   235 constraints from a theorem and proof, introducing explicit
   236 OFCLASS-premises.  On the proof term level, this operation is
   237 automatically applied at theorem boundaries, such that closed proofs
   238 are always free of sort constraints.  INCOMPATIBILITY for tools that
   239 inspect proof terms.
   240 
   241 * Local theory specifications may depend on extra type variables that
   242 are not present in the result type -- arguments TYPE('a) :: 'a itself
   243 are added internally.  For example:
   244 
   245   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   246 
   247 * Predicates of locales introduced by classes carry a mandatory
   248 "class" prefix.  INCOMPATIBILITY.
   249 
   250 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   251 
   252 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   253 'class' instead.
   254 
   255 * Command 'code_reflect' allows to incorporate generated ML code into
   256 runtime environment; replaces immature code_datatype antiquotation.
   257 INCOMPATIBILITY.
   258 
   259 * Code generator: simple concept for abstract datatypes obeying
   260 invariants.
   261 
   262 * Code generator: details of internal data cache have no impact on the
   263 user space functionality any longer.
   264 
   265 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   266 subgoals.  This is more appropriate for interpretations with 'where'.
   267 INCOMPATIBILITY.
   268 
   269 * Command 'example_proof' opens an empty proof body.  This allows to
   270 experiment with Isar, without producing any persistent result.
   271 
   272 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   273 within a local theory context, with explicit checking of the
   274 constructors involved (in contrast to the raw 'syntax' versions).
   275 
   276 * Commands 'types' and 'typedecl' now work within a local theory
   277 context -- without introducing dependencies on parameters or
   278 assumptions, which is not possible in Isabelle/Pure.
   279 
   280 * Command 'defaultsort' has been renamed to 'default_sort', it works
   281 within a local theory context.  Minor INCOMPATIBILITY.
   282 
   283 
   284 *** HOL ***
   285 
   286 * Command 'typedef' now works within a local theory context -- without
   287 introducing dependencies on parameters or assumptions, which is not
   288 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   289 contain multiple interpretations of local typedefs (with different
   290 non-emptiness proofs), even in a global theory context.
   291 
   292 * New package for quotient types.  Commands 'quotient_type' and
   293 'quotient_definition' may be used for defining types and constants by
   294 quotient constructions.  An example is the type of integers created by
   295 quotienting pairs of natural numbers:
   296 
   297   fun
   298     intrel :: "(nat * nat) => (nat * nat) => bool"
   299   where
   300     "intrel (x, y) (u, v) = (x + v = u + y)"
   301 
   302   quotient_type int = "nat * nat" / intrel
   303     by (auto simp add: equivp_def expand_fun_eq)
   304 
   305   quotient_definition
   306     "0::int" is "(0::nat, 0::nat)"
   307 
   308 The method "lifting" can be used to lift of theorems from the
   309 underlying "raw" type to the quotient type.  The example
   310 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   311 construction and provides a reasoning infrastructure for finite sets.
   312 
   313 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   314 clash with new theory Quotient in Main HOL.
   315 
   316 * Moved the SMT binding into the main HOL session, eliminating
   317 separate HOL-SMT session.
   318 
   319 * List membership infix mem operation is only an input abbreviation.
   320 INCOMPATIBILITY.
   321 
   322 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   323 for future developements; former Library/Word.thy is still present in
   324 the AFP entry RSAPPS.
   325 
   326 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   327 longer shadowed.  INCOMPATIBILITY.
   328 
   329 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   330 INCOMPATIBILITY.
   331 
   332 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   333 INCOMPATIBILITY.
   334 
   335 * Dropped normalizing_semiring etc; use the facts in semiring classes
   336 instead.  INCOMPATIBILITY.
   337 
   338 * Dropped several real-specific versions of lemmas about floor and
   339 ceiling; use the generic lemmas from theory "Archimedean_Field"
   340 instead.  INCOMPATIBILITY.
   341 
   342   floor_number_of_eq         ~> floor_number_of
   343   le_floor_eq_number_of      ~> number_of_le_floor
   344   le_floor_eq_zero           ~> zero_le_floor
   345   le_floor_eq_one            ~> one_le_floor
   346   floor_less_eq_number_of    ~> floor_less_number_of
   347   floor_less_eq_zero         ~> floor_less_zero
   348   floor_less_eq_one          ~> floor_less_one
   349   less_floor_eq_number_of    ~> number_of_less_floor
   350   less_floor_eq_zero         ~> zero_less_floor
   351   less_floor_eq_one          ~> one_less_floor
   352   floor_le_eq_number_of      ~> floor_le_number_of
   353   floor_le_eq_zero           ~> floor_le_zero
   354   floor_le_eq_one            ~> floor_le_one
   355   floor_subtract_number_of   ~> floor_diff_number_of
   356   floor_subtract_one         ~> floor_diff_one
   357   ceiling_number_of_eq       ~> ceiling_number_of
   358   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   359   ceiling_le_zero_eq         ~> ceiling_le_zero
   360   ceiling_le_eq_one          ~> ceiling_le_one
   361   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   362   less_ceiling_eq_zero       ~> zero_less_ceiling
   363   less_ceiling_eq_one        ~> one_less_ceiling
   364   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   365   ceiling_less_eq_zero       ~> ceiling_less_zero
   366   ceiling_less_eq_one        ~> ceiling_less_one
   367   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   368   le_ceiling_eq_zero         ~> zero_le_ceiling
   369   le_ceiling_eq_one          ~> one_le_ceiling
   370   ceiling_subtract_number_of ~> ceiling_diff_number_of
   371   ceiling_subtract_one       ~> ceiling_diff_one
   372 
   373 * Theory "Finite_Set": various folding_XXX locales facilitate the
   374 application of the various fold combinators on finite sets.
   375 
   376 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   377 provides abstract red-black tree type which is backed by "RBT_Impl" as
   378 implementation.  INCOMPATIBILTY.
   379 
   380 * Theory Library/Coinductive_List has been removed -- superseded by
   381 AFP/thys/Coinductive.
   382 
   383 * Theory PReal, including the type "preal" and related operations, has
   384 been removed.  INCOMPATIBILITY.
   385 
   386 * Real: new development using Cauchy Sequences.
   387 
   388 * Split off theory "Big_Operators" containing setsum, setprod,
   389 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   390 
   391 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   392 "Int" etc.  INCOMPATIBILITY.
   393 
   394 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   395 
   396 * New set of rules "ac_simps" provides combined assoc / commute
   397 rewrites for all interpretations of the appropriate generic locales.
   398 
   399 * Renamed theory "OrderedGroup" to "Groups" and split theory
   400 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   401 appropriate and more consistent names suitable for name prefixes
   402 within the HOL theories.  INCOMPATIBILITY.
   403 
   404 * Some generic constants have been put to appropriate theories:
   405   - less_eq, less: Orderings
   406   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   407   - inverse, divide: Rings
   408 INCOMPATIBILITY.
   409 
   410 * More consistent naming of type classes involving orderings (and
   411 lattices):
   412 
   413     lower_semilattice                   ~> semilattice_inf
   414     upper_semilattice                   ~> semilattice_sup
   415 
   416     dense_linear_order                  ~> dense_linorder
   417 
   418     pordered_ab_group_add               ~> ordered_ab_group_add
   419     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   420     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   421     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   422     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   423     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   424     pordered_cancel_semiring            ~> ordered_cancel_semiring
   425     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   426     pordered_comm_ring                  ~> ordered_comm_ring
   427     pordered_comm_semiring              ~> ordered_comm_semiring
   428     pordered_ring                       ~> ordered_ring
   429     pordered_ring_abs                   ~> ordered_ring_abs
   430     pordered_semiring                   ~> ordered_semiring
   431 
   432     ordered_ab_group_add                ~> linordered_ab_group_add
   433     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   434     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   435     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   436     ordered_field                       ~> linordered_field
   437     ordered_field_no_lb                 ~> linordered_field_no_lb
   438     ordered_field_no_ub                 ~> linordered_field_no_ub
   439     ordered_field_dense_linear_order    ~> dense_linordered_field
   440     ordered_idom                        ~> linordered_idom
   441     ordered_ring                        ~> linordered_ring
   442     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   443     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   444     ordered_ring_strict                 ~> linordered_ring_strict
   445     ordered_semidom                     ~> linordered_semidom
   446     ordered_semiring                    ~> linordered_semiring
   447     ordered_semiring_1                  ~> linordered_semiring_1
   448     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   449     ordered_semiring_strict             ~> linordered_semiring_strict
   450 
   451   The following slightly odd type classes have been moved to a
   452   separate theory Library/Lattice_Algebras:
   453 
   454     lordered_ab_group_add               ~> lattice_ab_group_add
   455     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   456     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   457     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   458     lordered_ring                       ~> lattice_ring
   459 
   460 INCOMPATIBILITY.
   461 
   462 * Refined field classes:
   463   - classes division_ring_inverse_zero, field_inverse_zero,
   464     linordered_field_inverse_zero include rule inverse 0 = 0 --
   465     subsumes former division_by_zero class;
   466   - numerous lemmas have been ported from field to division_ring.
   467 INCOMPATIBILITY.
   468 
   469 * Refined algebra theorem collections:
   470   - dropped theorem group group_simps, use algebra_simps instead;
   471   - dropped theorem group ring_simps, use field_simps instead;
   472   - proper theorem collection field_simps subsumes former theorem
   473     groups field_eq_simps and field_simps;
   474   - dropped lemma eq_minus_self_iff which is a duplicate for
   475     equal_neg_zero.
   476 INCOMPATIBILITY.
   477 
   478 * Theory Finite_Set and List: some lemmas have been generalized from
   479 sets to lattices:
   480 
   481   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   482   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   483   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   484   union_Union_fold_union        ~> sup_Sup_fold_sup
   485   Inter_fold_inter              ~> Inf_fold_inf
   486   Union_fold_union              ~> Sup_fold_sup
   487   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   488   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   489   INTER_fold_inter              ~> INFI_fold_inf
   490   UNION_fold_union              ~> SUPR_fold_sup
   491 
   492 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   493 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   494 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   495 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   496 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   497 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   498 
   499 * Reorganized theory Multiset: swapped notation of pointwise and
   500 multiset order:
   501 
   502   - pointwise ordering is instance of class order with standard syntax
   503     <= and <;
   504   - multiset ordering has syntax <=# and <#; partial order properties
   505     are provided by means of interpretation with prefix
   506     multiset_order;
   507   - less duplication, less historical organization of sections,
   508     conversion from associations lists to multisets, rudimentary code
   509     generation;
   510   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   511     if needed.
   512 
   513 Renamed:
   514 
   515   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   516   multi_count_ext  ~>  multiset_ext
   517   diff_union_inverse2  ~>  diff_union_cancelR
   518 
   519 INCOMPATIBILITY.
   520 
   521 * Theory Permutation: replaced local "remove" by List.remove1.
   522 
   523 * Code generation: ML and OCaml code is decorated with signatures.
   524 
   525 * Theory List: added transpose.
   526 
   527 * Library/Nat_Bijection.thy is a collection of bijective functions
   528 between nat and other types, which supersedes the older libraries
   529 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   530 
   531   Constants:
   532   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   533   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   534   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   535   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   536   Countable.pair_encode           ~> prod_encode
   537   NatIso.prod2nat                 ~> prod_encode
   538   NatIso.nat2prod                 ~> prod_decode
   539   NatIso.sum2nat                  ~> sum_encode
   540   NatIso.nat2sum                  ~> sum_decode
   541   NatIso.list2nat                 ~> list_encode
   542   NatIso.nat2list                 ~> list_decode
   543   NatIso.set2nat                  ~> set_encode
   544   NatIso.nat2set                  ~> set_decode
   545 
   546   Lemmas:
   547   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   548   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   549   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   550   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   551   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   552   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   553   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   554   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   555   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   556   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   557   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   558   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   559   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   560 
   561 * Sledgehammer:
   562   - Renamed ATP commands:
   563     atp_info     ~> sledgehammer running_atps
   564     atp_kill     ~> sledgehammer kill_atps
   565     atp_messages ~> sledgehammer messages
   566     atp_minimize ~> sledgehammer minimize
   567     print_atps   ~> sledgehammer available_atps
   568     INCOMPATIBILITY.
   569   - Added user's manual ("isabelle doc sledgehammer").
   570   - Added option syntax and "sledgehammer_params" to customize
   571     Sledgehammer's behavior.  See the manual for details.
   572   - Modified the Isar proof reconstruction code so that it produces
   573     direct proofs rather than proofs by contradiction.  (This feature
   574     is still experimental.)
   575   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   576     full-typed mode.
   577   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   578 
   579 * Nitpick:
   580   - Added and implemented "binary_ints" and "bits" options.
   581   - Added "std" option and implemented support for nonstandard models.
   582   - Added and implemented "finitize" option to improve the precision
   583     of infinite datatypes based on a monotonicity analysis.
   584   - Added support for quotient types.
   585   - Added support for "specification" and "ax_specification"
   586     constructs.
   587   - Added support for local definitions (for "function" and
   588     "termination" proofs).
   589   - Added support for term postprocessors.
   590   - Optimized "Multiset.multiset" and "FinFun.finfun".
   591   - Improved efficiency of "destroy_constrs" optimization.
   592   - Fixed soundness bugs related to "destroy_constrs" optimization and
   593     record getters.
   594   - Fixed soundness bug related to higher-order constructors.
   595   - Fixed soundness bug when "full_descrs" is enabled.
   596   - Improved precision of set constructs.
   597   - Added "atoms" option.
   598   - Added cache to speed up repeated Kodkod invocations on the same
   599     problems.
   600   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   601     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   602     "SAT4J_Light".  INCOMPATIBILITY.
   603   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   604     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   605   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   606 
   607 * Method "induct" now takes instantiations of the form t, where t is not
   608   a variable, as a shorthand for "x == t", where x is a fresh variable.
   609   If this is not intended, t has to be enclosed in parentheses.
   610   By default, the equalities generated by definitional instantiations
   611   are pre-simplified, which may cause parameters of inductive cases
   612   to disappear, or may even delete some of the inductive cases.
   613   Use "induct (no_simp)" instead of "induct" to restore the old
   614   behaviour. The (no_simp) option is also understood by the "cases"
   615   and "nominal_induct" methods, which now perform pre-simplification, too.
   616   INCOMPATIBILITY.
   617 
   618 
   619 *** HOLCF ***
   620 
   621 * Variable names in lemmas generated by the domain package have
   622 changed; the naming scheme is now consistent with the HOL datatype
   623 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   624 
   625 * The domain package no longer defines the function "foo_copy" for
   626 recursive domain "foo".  The reach lemma is now stated directly in
   627 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   628 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   629 
   630 * Most definedness lemmas generated by the domain package (previously
   631 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   632 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   633 Proofs that used definedness lemmas as intro rules may break,
   634 potential INCOMPATIBILITY.
   635 
   636 * Induction and casedist rules generated by the domain package now
   637 declare proper case_names (one called "bottom", and one named for each
   638 constructor).  INCOMPATIBILITY.
   639 
   640 * For mutually-recursive domains, separate "reach" and "take_lemma"
   641 rules are generated for each domain, INCOMPATIBILITY.
   642 
   643   foo_bar.reach       ~> foo.reach  bar.reach
   644   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   645 
   646 * Some lemmas generated by the domain package have been renamed for
   647 consistency with the datatype package, INCOMPATIBILITY.
   648 
   649   foo.ind        ~> foo.induct
   650   foo.finite_ind ~> foo.finite_induct
   651   foo.coind      ~> foo.coinduct
   652   foo.casedist   ~> foo.exhaust
   653   foo.exhaust    ~> foo.nchotomy
   654 
   655 * For consistency with other definition packages, the fixrec package
   656 now generates qualified theorem names, INCOMPATIBILITY.
   657 
   658   foo_simps  ~> foo.simps
   659   foo_unfold ~> foo.unfold
   660   foo_induct ~> foo.induct
   661 
   662 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   663 method and internal fixrec proofs now use the default simpset instead.
   664 INCOMPATIBILITY.
   665 
   666 * The "contlub" predicate has been removed.  Proof scripts should use
   667 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   668 
   669 * The "admw" predicate has been removed, INCOMPATIBILITY.
   670 
   671 * The constants cpair, cfst, and csnd have been removed in favor of
   672 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   673 
   674 
   675 *** ML ***
   676 
   677 * Antiquotations for basic formal entities:
   678 
   679     @{class NAME}         -- type class
   680     @{class_syntax NAME}  -- syntax representation of the above
   681 
   682     @{type_name NAME}     -- logical type
   683     @{type_abbrev NAME}   -- type abbreviation
   684     @{nonterminal NAME}   -- type of concrete syntactic category
   685     @{type_syntax NAME}   -- syntax representation of any of the above
   686 
   687     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   688     @{const_abbrev NAME}  -- abbreviated constant
   689     @{const_syntax NAME}  -- syntax representation of any of the above
   690 
   691 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   692 syntax constant (cf. 'syntax' command).
   693 
   694 * Antiquotation @{make_string} inlines a function to print arbitrary
   695 values similar to the ML toplevel.  The result is compiler dependent
   696 and may fall back on "?" in certain situations.
   697 
   698 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   699 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   700 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   701 not work with the asynchronous Isar document model.
   702 
   703 * Configuration options now admit dynamic default values, depending on
   704 the context or even global references.
   705 
   706 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   707 uses an efficient external library if available (for Poly/ML).
   708 
   709 * Renamed some important ML structures, while keeping the old names
   710 for some time as aliases within the structure Legacy:
   711 
   712   OuterKeyword  ~>  Keyword
   713   OuterLex      ~>  Token
   714   OuterParse    ~>  Parse
   715   OuterSyntax   ~>  Outer_Syntax
   716   PrintMode     ~>  Print_Mode
   717   SpecParse     ~>  Parse_Spec
   718   ThyInfo       ~>  Thy_Info
   719   ThyLoad       ~>  Thy_Load
   720   ThyOutput     ~>  Thy_Output
   721   TypeInfer     ~>  Type_Infer
   722 
   723 Note that "open Legacy" simplifies porting of sources, but forgetting
   724 to remove it again will complicate porting again in the future.
   725 
   726 * Most operations that refer to a global context are named
   727 accordingly, e.g. Simplifier.global_context or
   728 ProofContext.init_global.  There are some situations where a global
   729 context actually works, but under normal circumstances one needs to
   730 pass the proper local context through the code!
   731 
   732 * Discontinued old TheoryDataFun with its copy/init operation -- data
   733 needs to be pure.  Functor Theory_Data_PP retains the traditional
   734 Pretty.pp argument to merge, which is absent in the standard
   735 Theory_Data version.
   736 
   737 * Sorts.certify_sort and derived "cert" operations for types and terms
   738 no longer minimize sorts.  Thus certification at the boundary of the
   739 inference kernel becomes invariant under addition of class relations,
   740 which is an important monotonicity principle.  Sorts are now minimized
   741 in the syntax layer only, at the boundary between the end-user and the
   742 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   743 explicitly in rare situations.
   744 
   745 * Renamed old-style Drule.standard to Drule.export_without_context, to
   746 emphasize that this is in no way a standard operation.
   747 INCOMPATIBILITY.
   748 
   749 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   750 usual for resolution.  Rare INCOMPATIBILITY.
   751 
   752 * Renamed varify/unvarify operations to varify_global/unvarify_global
   753 to emphasize that these only work in a global situation (which is
   754 quite rare).
   755 
   756 * Curried take and drop in library.ML; negative length is interpreted
   757 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   758 
   759 * Proof terms: type substitutions on proof constants now use canonical
   760 order of type variables.  INCOMPATIBILITY for tools working with proof
   761 terms.
   762 
   763 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   764 may no longer carry premises.  User-level specifications are
   765 transformed accordingly by Thm.add_axiom/add_def.
   766 
   767 
   768 *** System ***
   769 
   770 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   771 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   772 proof terms are enabled unconditionally in the new HOL-Proofs image.
   773 
   774 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   775 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   776 respectively.
   777 
   778 * Old lib/scripts/polyml-platform is superseded by the
   779 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   780 variant, even on a 64 bit machine.  The following example setting
   781 prefers 64 bit if available:
   782 
   783   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   784 
   785 * The preliminary Isabelle/jEdit application demonstrates the emerging
   786 Isabelle/Scala layer for advanced prover interaction and integration.
   787 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   788 component.
   789 
   790 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   791 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   792 similar to the default assignment of the document preparation system
   793 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   794 provides some operations for direct access to the font without asking
   795 the user for manual installation.
   796 
   797 
   798 
   799 New in Isabelle2009-1 (December 2009)
   800 -------------------------------------
   801 
   802 *** General ***
   803 
   804 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   805 one backslash should be used, even in ML sources.
   806 
   807 
   808 *** Pure ***
   809 
   810 * Locale interpretation propagates mixins along the locale hierarchy.
   811 The currently only available mixins are the equations used to map
   812 local definitions to terms of the target domain of an interpretation.
   813 
   814 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   815 loc" to print all interpretations of locale "loc" in the theory.
   816 Interpretations in proofs are not shown.
   817 
   818 * Thoroughly revised locales tutorial.  New section on conditional
   819 interpretation.
   820 
   821 * On instantiation of classes, remaining undefined class parameters
   822 are formally declared.  INCOMPATIBILITY.
   823 
   824 
   825 *** Document preparation ***
   826 
   827 * New generalized style concept for printing terms: @{foo (style) ...}
   828 instead of @{foo_style style ...}  (old form is still retained for
   829 backward compatibility).  Styles can be also applied for
   830 antiquotations prop, term_type and typeof.
   831 
   832 
   833 *** HOL ***
   834 
   835 * New proof method "smt" for a combination of first-order logic with
   836 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   837 fixed-size bitvectors; there is also basic support for higher-order
   838 features (esp. lambda abstractions).  It is an incomplete decision
   839 procedure based on external SMT solvers using the oracle mechanism;
   840 for the SMT solver Z3, this method is proof-producing.  Certificates
   841 are provided to avoid calling the external solvers solely for
   842 re-checking proofs.  Due to a remote SMT service there is no need for
   843 installing SMT solvers locally.  See src/HOL/SMT.
   844 
   845 * New commands to load and prove verification conditions generated by
   846 the Boogie program verifier or derived systems (e.g. the Verifying C
   847 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   848 
   849 * New counterexample generator tool 'nitpick' based on the Kodkod
   850 relational model finder.  See src/HOL/Tools/Nitpick and
   851 src/HOL/Nitpick_Examples.
   852 
   853 * New commands 'code_pred' and 'values' to invoke the predicate
   854 compiler and to enumerate values of inductive predicates.
   855 
   856 * A tabled implementation of the reflexive transitive closure.
   857 
   858 * New implementation of quickcheck uses generic code generator;
   859 default generators are provided for all suitable HOL types, records
   860 and datatypes.  Old quickcheck can be re-activated importing theory
   861 Library/SML_Quickcheck.
   862 
   863 * New testing tool Mirabelle for automated proof tools.  Applies
   864 several tools and tactics like sledgehammer, metis, or quickcheck, to
   865 every proof step in a theory.  To be used in batch mode via the
   866 "mirabelle" utility.
   867 
   868 * New proof method "sos" (sum of squares) for nonlinear real
   869 arithmetic (originally due to John Harison). It requires theory
   870 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   871 works well in practice on quantifier-free real arithmetic with +, -,
   872 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   873 inequalities between polynomials.  It makes use of external
   874 semidefinite programming solvers.  Method "sos" generates a
   875 certificate that can be pasted into the proof thus avoiding the need
   876 to call an external tool every time the proof is checked.  See
   877 src/HOL/Library/Sum_Of_Squares.
   878 
   879 * New method "linarith" invokes existing linear arithmetic decision
   880 procedure only.
   881 
   882 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   883 
   884 * New Sledgehammer option "Full Types" in Proof General settings menu.
   885 Causes full type information to be output to the ATPs.  This slows
   886 ATPs down considerably but eliminates a source of unsound "proofs"
   887 that fail later.
   888 
   889 * New method "metisFT": A version of metis that uses full type
   890 information in order to avoid failures of proof reconstruction.
   891 
   892 * New evaluator "approximate" approximates an real valued term using
   893 the same method as the approximation method.
   894 
   895 * Method "approximate" now supports arithmetic expressions as
   896 boundaries of intervals and implements interval splitting and Taylor
   897 series expansion.
   898 
   899 * ML antiquotation @{code_datatype} inserts definition of a datatype
   900 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   901 
   902 * New theory SupInf of the supremum and infimum operators for sets of
   903 reals.
   904 
   905 * New theory Probability, which contains a development of measure
   906 theory, eventually leading to Lebesgue integration and probability.
   907 
   908 * Extended Multivariate Analysis to include derivation and Brouwer's
   909 fixpoint theorem.
   910 
   911 * Reorganization of number theory, INCOMPATIBILITY:
   912   - new number theory development for nat and int, in theories Divides
   913     and GCD as well as in new session Number_Theory
   914   - some constants and facts now suffixed with _nat and _int
   915     accordingly
   916   - former session NumberTheory now named Old_Number_Theory, including
   917     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   918   - moved theory Pocklington from src/HOL/Library to
   919     src/HOL/Old_Number_Theory
   920 
   921 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   922 lcm of finite and infinite sets. It is shown that they form a complete
   923 lattice.
   924 
   925 * Class semiring_div requires superclass no_zero_divisors and proof of
   926 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   927 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   928 generalized to class semiring_div, subsuming former theorems
   929 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   930 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   931 INCOMPATIBILITY.
   932 
   933 * Refinements to lattice classes and sets:
   934   - less default intro/elim rules in locale variant, more default
   935     intro/elim rules in class variant: more uniformity
   936   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   937     le_inf_iff
   938   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   939     sup_aci)
   940   - renamed ACI to inf_sup_aci
   941   - new class "boolean_algebra"
   942   - class "complete_lattice" moved to separate theory
   943     "Complete_Lattice"; corresponding constants (and abbreviations)
   944     renamed and with authentic syntax:
   945     Set.Inf ~>    Complete_Lattice.Inf
   946     Set.Sup ~>    Complete_Lattice.Sup
   947     Set.INFI ~>   Complete_Lattice.INFI
   948     Set.SUPR ~>   Complete_Lattice.SUPR
   949     Set.Inter ~>  Complete_Lattice.Inter
   950     Set.Union ~>  Complete_Lattice.Union
   951     Set.INTER ~>  Complete_Lattice.INTER
   952     Set.UNION ~>  Complete_Lattice.UNION
   953   - authentic syntax for
   954     Set.Pow
   955     Set.image
   956   - mere abbreviations:
   957     Set.empty               (for bot)
   958     Set.UNIV                (for top)
   959     Set.inter               (for inf, formerly Set.Int)
   960     Set.union               (for sup, formerly Set.Un)
   961     Complete_Lattice.Inter  (for Inf)
   962     Complete_Lattice.Union  (for Sup)
   963     Complete_Lattice.INTER  (for INFI)
   964     Complete_Lattice.UNION  (for SUPR)
   965   - object-logic definitions as far as appropriate
   966 
   967 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   968 Un_subset_iff are explicitly deleted as default simp rules; then also
   969 their lattice counterparts le_inf_iff and le_sup_iff have to be
   970 deleted to achieve the desired effect.
   971 
   972 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   973 rules by default any longer; the same applies to min_max.inf_absorb1
   974 etc.  INCOMPATIBILITY.
   975 
   976 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   977 pred_set_conv by default.  INCOMPATIBILITY.
   978 
   979 * Power operations on relations and functions are now one dedicated
   980 constant "compow" with infix syntax "^^".  Power operation on
   981 multiplicative monoids retains syntax "^" and is now defined generic
   982 in class power.  INCOMPATIBILITY.
   983 
   984 * Relation composition "R O S" now has a more standard argument order:
   985 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   986 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   987 break, since the O_assoc rule was not rewritten like this.  Fix using
   988 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   989 
   990 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   991 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   992 INCOMPATIBILITY.
   993 
   994 * Most rules produced by inductive and datatype package have mandatory
   995 prefixes.  INCOMPATIBILITY.
   996 
   997 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   998 the attribute of the same name.  Each of the theorems in the list
   999 DERIV_intros assumes composition with an additional function and
  1000 matches a variable to the derivative, which has to be solved by the
  1001 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1002 of most elementary terms.  Former Maclauren.DERIV_tac and
  1003 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1004 INCOMPATIBILITY.
  1005 
  1006 * Code generator attributes follow the usual underscore convention:
  1007     code_unfold     replaces    code unfold
  1008     code_post       replaces    code post
  1009     etc.
  1010   INCOMPATIBILITY.
  1011 
  1012 * Renamed methods:
  1013     sizechange -> size_change
  1014     induct_scheme -> induction_schema
  1015   INCOMPATIBILITY.
  1016 
  1017 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1018 INCOMPATIBILITY, use "undefined" directly.
  1019 
  1020 * Renamed theorems:
  1021     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1022     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1023     Suc_plus1 -> Suc_eq_plus1
  1024     *anti_sym -> *antisym*
  1025     vector_less_eq_def -> vector_le_def
  1026   INCOMPATIBILITY.
  1027 
  1028 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1029 INCOMPATIBILITY.
  1030 
  1031 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1032 INCOMPATIBILITY.
  1033 
  1034 
  1035 *** HOLCF ***
  1036 
  1037 * Theory Representable defines a class "rep" of domains that are
  1038 representable (via an ep-pair) in the universal domain type "udom".
  1039 Instances are provided for all type constructors defined in HOLCF.
  1040 
  1041 * The 'new_domain' command is a purely definitional version of the
  1042 domain package, for representable domains.  Syntax is identical to the
  1043 old domain package.  The 'new_domain' package also supports indirect
  1044 recursion using previously-defined type constructors.  See
  1045 src/HOLCF/ex/New_Domain.thy for examples.
  1046 
  1047 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1048 on the left-hand side of an equation, and then performs
  1049 simplification.  Rewriting is done using rules declared with the
  1050 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1051 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1052 
  1053 * The pattern-match compiler in 'fixrec' can now handle constructors
  1054 with HOL function types.  Pattern-match combinators for the Pair
  1055 constructor are pre-configured.
  1056 
  1057 * The 'fixrec' package now produces better fixed-point induction rules
  1058 for mutually-recursive definitions:  Induction rules have conclusions
  1059 of the form "P foo bar" instead of "P <foo, bar>".
  1060 
  1061 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1062 been renamed to "below".  The name "below" now replaces "less" in many
  1063 theorem names.  (Legacy theorem names using "less" are still supported
  1064 as well.)
  1065 
  1066 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1067 patterns can be used to generate strictness rules, or to make
  1068 functions more strict (much like the bang-patterns supported by the
  1069 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1070 examples.
  1071 
  1072 
  1073 *** ML ***
  1074 
  1075 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1076 errors and run-time exceptions, including detailed source positions.
  1077 
  1078 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1079 identified entries, with some additional information such as source
  1080 position, logical grouping etc.
  1081 
  1082 * Theory and context data is now introduced by the simplified and
  1083 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1084 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1085 copy operation) is still available for some time.
  1086 
  1087 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1088 provides a high-level programming interface to synchronized state
  1089 variables with atomic update.  This works via pure function
  1090 application within a critical section -- its runtime should be as
  1091 short as possible; beware of deadlocks if critical code is nested,
  1092 either directly or indirectly via other synchronized variables!
  1093 
  1094 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1095 wraps raw ML references, explicitly indicating their non-thread-safe
  1096 behaviour.  The Isar toplevel keeps this structure open, to
  1097 accommodate Proof General as well as quick and dirty interactive
  1098 experiments with references.
  1099 
  1100 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1101 parallel tactical reasoning.
  1102 
  1103 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1104 are similar to SUBPROOF, but are slightly more flexible: only the
  1105 specified parts of the subgoal are imported into the context, and the
  1106 body tactic may introduce new subgoals and schematic variables.
  1107 
  1108 * Old tactical METAHYPS, which does not observe the proof context, has
  1109 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1110 or Subgoal.FOCUS etc.
  1111 
  1112 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1113 functors have their own ML name space there is no point to mark them
  1114 separately.)  Minor INCOMPATIBILITY.
  1115 
  1116 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1117 
  1118 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1119 INCOMPATIBILITY.
  1120 
  1121 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1122 mode, which avoids critical setmp.
  1123 
  1124 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1125 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1126 Attrib/Method.setup introduced in Isabelle2009.
  1127 
  1128 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1129 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1130 last resort.  INCOMPATIBILITY.
  1131 
  1132 * Display.pretty_thm now requires a proper context (cf. former
  1133 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1134 or even Display.pretty_thm_without_context as last resort.
  1135 INCOMPATIBILITY.
  1136 
  1137 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1138 Syntax.pretty_typ/term directly, preferably with proper context
  1139 instead of global theory.
  1140 
  1141 
  1142 *** System ***
  1143 
  1144 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1145 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1146 usedir option -q.
  1147 
  1148 * Support for additional "Isabelle components" via etc/components, see
  1149 also the system manual.
  1150 
  1151 * The isabelle makeall tool now operates on all components with
  1152 IsaMakefile, not just hardwired "logics".
  1153 
  1154 * Removed "compress" option from isabelle-process and isabelle usedir;
  1155 this is always enabled.
  1156 
  1157 * Discontinued support for Poly/ML 4.x versions.
  1158 
  1159 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1160 on a given logic image.  This requires the lighttpd webserver and is
  1161 currently supported on Linux only.
  1162 
  1163 
  1164 
  1165 New in Isabelle2009 (April 2009)
  1166 --------------------------------
  1167 
  1168 *** General ***
  1169 
  1170 * Simplified main Isabelle executables, with less surprises on
  1171 case-insensitive file-systems (such as Mac OS).
  1172 
  1173   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1174     "isatool."
  1175 
  1176   - The former "isabelle" alias for "isabelle-process" has been
  1177     removed (should rarely occur to regular users).
  1178 
  1179   - The former "isabelle-interface" and its alias "Isabelle" have been
  1180     removed (interfaces are now regular Isabelle tools).
  1181 
  1182 Within scripts and make files, the Isabelle environment variables
  1183 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1184 respectively.  (The latter are still available as legacy feature.)
  1185 
  1186 The old isabelle-interface wrapper could react in confusing ways if
  1187 the interface was uninstalled or changed otherwise.  Individual
  1188 interface tool configuration is now more explicit, see also the
  1189 Isabelle system manual.  In particular, Proof General is now available
  1190 via "isabelle emacs".
  1191 
  1192 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1193 purge installed copies of Isabelle executables and re-run "isabelle
  1194 install -p ...", or use symlinks.
  1195 
  1196 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1197 old ~/isabelle, which was slightly non-standard and apt to cause
  1198 surprises on case-insensitive file-systems (such as Mac OS).
  1199 
  1200 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1201 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1202 care is required when using older releases of Isabelle.  Note that
  1203 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1204 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1205 
  1206 * Proofs of fully specified statements are run in parallel on
  1207 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1208 a regular 4-core machine, if the initial heap space is made reasonably
  1209 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1210 
  1211 * The main reference manuals ("isar-ref", "implementation", and
  1212 "system") have been updated and extended.  Formally checked references
  1213 as hyperlinks are now available uniformly.
  1214 
  1215 
  1216 *** Pure ***
  1217 
  1218 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1219 respects.  The most important changes are listed below.  See the
  1220 Tutorial on Locales ("locales" manual) for details.
  1221 
  1222 - In locale expressions, instantiation replaces renaming.  Parameters
  1223 must be declared in a for clause.  To aid compatibility with previous
  1224 parameter inheritance, in locale declarations, parameters that are not
  1225 'touched' (instantiation position "_" or omitted) are implicitly added
  1226 with their syntax at the beginning of the for clause.
  1227 
  1228 - Syntax from abbreviations and definitions in locales is available in
  1229 locale expressions and context elements.  The latter is particularly
  1230 useful in locale declarations.
  1231 
  1232 - More flexible mechanisms to qualify names generated by locale
  1233 expressions.  Qualifiers (prefixes) may be specified in locale
  1234 expressions, and can be marked as mandatory (syntax: "name!:") or
  1235 optional (syntax "name?:").  The default depends for plain "name:"
  1236 depends on the situation where a locale expression is used: in
  1237 commands 'locale' and 'sublocale' prefixes are optional, in
  1238 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1239 implicit qualifiers derived from the parameter names of a locale are
  1240 no longer generated.
  1241 
  1242 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1243 instantiation clause in "interpretation" and "interpret" (square
  1244 brackets) is no longer available.  Use locale expressions.
  1245 
  1246 - When converting proof scripts, mandatory qualifiers in
  1247 'interpretation' and 'interpret' should be retained by default, even
  1248 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1249 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1250 in locale expressions range over a single locale instance only.
  1251 
  1252 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1253 In existing theorem specifications replace the includes element by the
  1254 respective context elements of the included locale, omitting those
  1255 that are already present in the theorem specification.  Multiple
  1256 assume elements of a locale should be replaced by a single one
  1257 involving the locale predicate.  In the proof body, declarations (most
  1258 notably theorems) may be regained by interpreting the respective
  1259 locales in the proof context as required (command "interpret").
  1260 
  1261 If using "includes" in replacement of a target solely because the
  1262 parameter types in the theorem are not as general as in the target,
  1263 consider declaring a new locale with additional type constraints on
  1264 the parameters (context element "constrains").
  1265 
  1266 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1267 
  1268 - Locale interpretation commands no longer attempt to simplify goal.
  1269 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1270 methods intro_locales and unfold_locales to clarify.
  1271 
  1272 - Locale interpretation commands no longer accept interpretation
  1273 attributes.  INCOMPATIBILITY.
  1274 
  1275 * Class declaration: so-called "base sort" must not be given in import
  1276 list any longer, but is inferred from the specification.  Particularly
  1277 in HOL, write
  1278 
  1279     class foo = ...
  1280 
  1281 instead of
  1282 
  1283     class foo = type + ...
  1284 
  1285 * Class target: global versions of theorems stemming do not carry a
  1286 parameter prefix any longer.  INCOMPATIBILITY.
  1287 
  1288 * Class 'instance' command no longer accepts attached definitions.
  1289 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1290 
  1291 * Recovered hiding of consts, which was accidentally broken in
  1292 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1293 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1294 
  1295 * Slightly more coherent Pure syntax, with updated documentation in
  1296 isar-ref manual.  Removed locales meta_term_syntax and
  1297 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1298 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1299 directly in regular applications.
  1300 
  1301 * There is a new syntactic category "float_const" for signed decimal
  1302 fractions (e.g. 123.45 or -123.45).
  1303 
  1304 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1305 interface with 'setup' command instead.
  1306 
  1307 * Command 'local_setup' is similar to 'setup', but operates on a local
  1308 theory context.
  1309 
  1310 * The 'axiomatization' command now only works within a global theory
  1311 context.  INCOMPATIBILITY.
  1312 
  1313 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1314 hypotheses.  Sorts required in the course of reasoning need to be
  1315 covered by the constraints in the initial statement, completed by the
  1316 type instance information of the background theory.  Non-trivial sort
  1317 hypotheses, which rarely occur in practice, may be specified via
  1318 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1319 
  1320   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1321 
  1322 The result contains an implicit sort hypotheses as before --
  1323 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1324 normalization.
  1325 
  1326 * Generalized Isar history, with support for linear undo, direct state
  1327 addressing etc.
  1328 
  1329 * Changed defaults for unify configuration options:
  1330 
  1331   unify_trace_bound = 50 (formerly 25)
  1332   unify_search_bound = 60 (formerly 30)
  1333 
  1334 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1335 
  1336   a) On theory merge, the last set of code equations for a particular
  1337      constant is taken (in accordance with the policy applied by other
  1338      parts of the code generator framework).
  1339 
  1340   b) Code equations stemming from explicit declarations (e.g. code
  1341      attribute) gain priority over default code equations stemming
  1342      from definition, primrec, fun etc.
  1343 
  1344 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1345 
  1346 * Unified theorem tables for both code generators.  Thus [code
  1347 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1348 
  1349 * Command 'find_consts' searches for constants based on type and name
  1350 patterns, e.g.
  1351 
  1352     find_consts "_ => bool"
  1353 
  1354 By default, matching is against subtypes, but it may be restricted to
  1355 the whole type.  Searching by name is possible.  Multiple queries are
  1356 conjunctive and queries may be negated by prefixing them with a
  1357 hyphen:
  1358 
  1359     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1360 
  1361 * New 'find_theorems' criterion "solves" matches theorems that
  1362 directly solve the current goal (modulo higher-order unification).
  1363 
  1364 * Auto solve feature for main theorem statements: whenever a new goal
  1365 is stated, "find_theorems solves" is called; any theorems that could
  1366 solve the lemma directly are listed as part of the goal state.
  1367 Cf. associated options in Proof General Isabelle settings menu,
  1368 enabled by default, with reasonable timeout for pathological cases of
  1369 higher-order unification.
  1370 
  1371 
  1372 *** Document preparation ***
  1373 
  1374 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1375 demanding keyword 'by' and supporting the full method expression
  1376 syntax just like the Isar command 'by'.
  1377 
  1378 
  1379 *** HOL ***
  1380 
  1381 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1382 points Main and Complex_Main remain as before.
  1383 
  1384 * Logic image HOL-Plain provides a minimal HOL with the most important
  1385 tools available (inductive, datatype, primrec, ...).  This facilitates
  1386 experimentation and tool development.  Note that user applications
  1387 (and library theories) should never refer to anything below theory
  1388 Main, as before.
  1389 
  1390 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1391 experimentation due to shorter build times.
  1392 
  1393 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1394 were previously part of former HOL-Complex.  Entry point Hyperreal
  1395 remains valid, but theories formerly using Complex_Main should now use
  1396 new entry point Hypercomplex.
  1397 
  1398 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1399 Posix processes.  Avoids potentially expensive forking of the ML
  1400 process.  New thread-based implementation also works on non-Unix
  1401 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1402 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1403 commands are covered in the isar-ref manual.
  1404 
  1405 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1406 sledgehammer without local ATP installation (Vampire etc.). Other
  1407 provers may be included via suitable ML wrappers, see also
  1408 src/HOL/ATP_Linkup.thy.
  1409 
  1410 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1411 menu.
  1412 
  1413 * The metis method no longer fails because the theorem is too trivial
  1414 (contains the empty clause).
  1415 
  1416 * The metis method now fails in the usual manner, rather than raising
  1417 an exception, if it determines that it cannot prove the theorem.
  1418 
  1419 * Method "coherent" implements a prover for coherent logic (see also
  1420 src/Tools/coherent.ML).
  1421 
  1422 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1423 "undefined" is the right choice to replace "arbitrary", though
  1424 logically there is no difference.  INCOMPATIBILITY.
  1425 
  1426 * Command "value" now integrates different evaluation mechanisms.  The
  1427 result of the first successful evaluation mechanism is printed.  In
  1428 square brackets a particular named evaluation mechanisms may be
  1429 specified (currently, [SML], [code] or [nbe]).  See further
  1430 src/HOL/ex/Eval_Examples.thy.
  1431 
  1432 * Normalization by evaluation now allows non-leftlinear equations.
  1433 Declare with attribute [code nbe].
  1434 
  1435 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1436 as the structured Isar versions "cases" and "induct", cf. the
  1437 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1438 are now presented as a list of individual projections
  1439 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1440 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1441 rare situations a different rule is selected --- notably nested tuple
  1442 elimination instead of former prod.exhaust: use explicit (case_tac t
  1443 rule: prod.exhaust) here.
  1444 
  1445 * Attributes "cases", "induct", "coinduct" support "del" option.
  1446 
  1447 * Removed fact "case_split_thm", which duplicates "case_split".
  1448 
  1449 * The option datatype has been moved to a new theory Option.  Renamed
  1450 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1451 
  1452 * New predicate "strict_mono" classifies strict functions on partial
  1453 orders.  With strict functions on linear orders, reasoning about
  1454 (in)equalities is facilitated by theorems "strict_mono_eq",
  1455 "strict_mono_less_eq" and "strict_mono_less".
  1456 
  1457 * Some set operations are now proper qualified constants with
  1458 authentic syntax.  INCOMPATIBILITY:
  1459 
  1460     op Int ~>   Set.Int
  1461     op Un ~>    Set.Un
  1462     INTER ~>    Set.INTER
  1463     UNION ~>    Set.UNION
  1464     Inter ~>    Set.Inter
  1465     Union ~>    Set.Union
  1466     {} ~>       Set.empty
  1467     UNIV ~>     Set.UNIV
  1468 
  1469 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1470 theory Set.
  1471 
  1472 * Auxiliary class "itself" has disappeared -- classes without any
  1473 parameter are treated as expected by the 'class' command.
  1474 
  1475 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1476 
  1477 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1478 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1479 
  1480 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1481 method "approximation".  It proves formulas on real values by using
  1482 interval arithmetic.  In the formulas are also the transcendental
  1483 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1484 allowed. For examples see
  1485 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1486 
  1487 * Theory "Reflection" now resides in HOL/Library.
  1488 
  1489 * Entry point to Word library now simply named "Word".
  1490 INCOMPATIBILITY.
  1491 
  1492 * Made source layout more coherent with logical distribution
  1493 structure:
  1494 
  1495     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1496     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1497     src/HOL/Library/GCD.thy ~> src/HOL/
  1498     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1499     src/HOL/Library/Parity.thy ~> src/HOL/
  1500     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1501     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1502     src/HOL/Real/Lubs.thy ~> src/HOL/
  1503     src/HOL/Real/PReal.thy ~> src/HOL/
  1504     src/HOL/Real/Rational.thy ~> src/HOL/
  1505     src/HOL/Real/RComplete.thy ~> src/HOL/
  1506     src/HOL/Real/RealDef.thy ~> src/HOL/
  1507     src/HOL/Real/RealPow.thy ~> src/HOL/
  1508     src/HOL/Real/Real.thy ~> src/HOL/
  1509     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1510     src/HOL/Complex/Complex.thy ~> src/HOL/
  1511     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1512     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1513     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1514     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1515     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1516     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1517     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1518     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1519     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1520     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1521     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1522     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1523     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1524     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1525     src/HOL/Real/Float ~> src/HOL/Library/
  1526     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1527     src/HOL/Real/RealVector.thy ~> src/HOL/
  1528 
  1529     src/HOL/arith_data.ML ~> src/HOL/Tools
  1530     src/HOL/hologic.ML ~> src/HOL/Tools
  1531     src/HOL/simpdata.ML ~> src/HOL/Tools
  1532     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1533     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1534     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1535     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1536     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1537     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1538     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1539 
  1540     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1541     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1542     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1543     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1544     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1545     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1546 
  1547 * If methods "eval" and "evaluation" encounter a structured proof
  1548 state with !!/==>, only the conclusion is evaluated to True (if
  1549 possible), avoiding strange error messages.
  1550 
  1551 * Method "sizechange" automates termination proofs using (a
  1552 modification of) the size-change principle.  Requires SAT solver.  See
  1553 src/HOL/ex/Termination.thy for examples.
  1554 
  1555 * Simplifier: simproc for let expressions now unfolds if bound
  1556 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1557 
  1558 * Method "arith": Linear arithmetic now ignores all inequalities when
  1559 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1560 
  1561 * New attribute "arith" for facts that should always be used
  1562 automatically by arithmetic. It is intended to be used locally in
  1563 proofs, e.g.
  1564 
  1565   assumes [arith]: "x > 0"
  1566 
  1567 Global usage is discouraged because of possible performance impact.
  1568 
  1569 * New classes "top" and "bot" with corresponding operations "top" and
  1570 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1571 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1572 
  1573 * Changed definition lemma "less_fun_def" in order to provide an
  1574 instance for preorders on functions; use lemma "less_le" instead.
  1575 INCOMPATIBILITY.
  1576 
  1577 * Theory Orderings: class "wellorder" moved here, with explicit
  1578 induction rule "less_induct" as assumption.  For instantiation of
  1579 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1580 INCOMPATIBILITY.
  1581 
  1582 * Theory Orderings: added class "preorder" as superclass of "order".
  1583 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1584 etc. slightly changed.  Some theorems named order_class.* now named
  1585 preorder_class.*.
  1586 
  1587 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1588 "diag" to "Id_on".
  1589 
  1590 * Theory Finite_Set: added a new fold combinator of type
  1591 
  1592   ('a => 'b => 'b) => 'b => 'a set => 'b
  1593 
  1594 Occasionally this is more convenient than the old fold combinator
  1595 which is now defined in terms of the new one and renamed to
  1596 fold_image.
  1597 
  1598 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1599 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1600 extended with further lemmas!).  At the moment both still exist but
  1601 the former will disappear at some point.
  1602 
  1603 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1604 class recpower.  Type-specific simp rules for various recpower types
  1605 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1606 
  1607 rat_power_0    -> power_0
  1608 rat_power_Suc  -> power_Suc
  1609 realpow_0      -> power_0
  1610 realpow_Suc    -> power_Suc
  1611 complexpow_0   -> power_0
  1612 complexpow_Suc -> power_Suc
  1613 power_poly_0   -> power_0
  1614 power_poly_Suc -> power_Suc
  1615 
  1616 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1617 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1618 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1619 of lemmas from Divides has been generalized from nat to class
  1620 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1621 renames resulting from duplicate elimination:
  1622 
  1623     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1624     zero_dvd_iff ~>         dvd_0_left_iff
  1625     dvd_0 ~>                dvd_0_right
  1626     DIVISION_BY_ZERO_DIV ~> div_by_0
  1627     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1628     mult_div ~>             div_mult_self2_is_id
  1629     mult_mod ~>             mod_mult_self2_is_0
  1630 
  1631 * Theory IntDiv: removed many lemmas that are instances of class-based
  1632 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1633 rename old lemmas as follows:
  1634 
  1635 dvd_diff               -> nat_dvd_diff
  1636 dvd_zminus_iff         -> dvd_minus_iff
  1637 mod_add1_eq            -> mod_add_eq
  1638 mod_mult1_eq           -> mod_mult_right_eq
  1639 mod_mult1_eq'          -> mod_mult_left_eq
  1640 mod_mult_distrib_mod   -> mod_mult_eq
  1641 nat_mod_add_left_eq    -> mod_add_left_eq
  1642 nat_mod_add_right_eq   -> mod_add_right_eq
  1643 nat_mod_div_trivial    -> mod_div_trivial
  1644 nat_mod_mod_trivial    -> mod_mod_trivial
  1645 zdiv_zadd_self1        -> div_add_self1
  1646 zdiv_zadd_self2        -> div_add_self2
  1647 zdiv_zmult_self1       -> div_mult_self2_is_id
  1648 zdiv_zmult_self2       -> div_mult_self1_is_id
  1649 zdvd_triv_left         -> dvd_triv_left
  1650 zdvd_triv_right        -> dvd_triv_right
  1651 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1652 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1653 zmod_zadd_left_eq      -> mod_add_left_eq
  1654 zmod_zadd_right_eq     -> mod_add_right_eq
  1655 zmod_zadd_self1        -> mod_add_self1
  1656 zmod_zadd_self2        -> mod_add_self2
  1657 zmod_zadd1_eq          -> mod_add_eq
  1658 zmod_zdiff1_eq         -> mod_diff_eq
  1659 zmod_zdvd_zmod         -> mod_mod_cancel
  1660 zmod_zmod_cancel       -> mod_mod_cancel
  1661 zmod_zmult_self1       -> mod_mult_self2_is_0
  1662 zmod_zmult_self2       -> mod_mult_self1_is_0
  1663 zmod_1                 -> mod_by_1
  1664 zdiv_1                 -> div_by_1
  1665 zdvd_abs1              -> abs_dvd_iff
  1666 zdvd_abs2              -> dvd_abs_iff
  1667 zdvd_refl              -> dvd_refl
  1668 zdvd_trans             -> dvd_trans
  1669 zdvd_zadd              -> dvd_add
  1670 zdvd_zdiff             -> dvd_diff
  1671 zdvd_zminus_iff        -> dvd_minus_iff
  1672 zdvd_zminus2_iff       -> minus_dvd_iff
  1673 zdvd_zmultD            -> dvd_mult_right
  1674 zdvd_zmultD2           -> dvd_mult_left
  1675 zdvd_zmult_mono        -> mult_dvd_mono
  1676 zdvd_0_right           -> dvd_0_right
  1677 zdvd_0_left            -> dvd_0_left_iff
  1678 zdvd_1_left            -> one_dvd
  1679 zminus_dvd_iff         -> minus_dvd_iff
  1680 
  1681 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1682 
  1683 * The real numbers offer decimal input syntax: 12.34 is translated
  1684 into 1234/10^2. This translation is not reversed upon output.
  1685 
  1686 * Theory Library/Polynomial defines an abstract type 'a poly of
  1687 univariate polynomials with coefficients of type 'a.  In addition to
  1688 the standard ring operations, it also supports div and mod.  Code
  1689 generation is also supported, using list-style constructors.
  1690 
  1691 * Theory Library/Inner_Product defines a class of real_inner for real
  1692 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1693 => real.  Class real_inner is a subclass of real_normed_vector from
  1694 theory RealVector.
  1695 
  1696 * Theory Library/Product_Vector provides instances for the product
  1697 type 'a * 'b of several classes from RealVector and Inner_Product.
  1698 Definitions of addition, subtraction, scalar multiplication, norms,
  1699 and inner products are included.
  1700 
  1701 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1702 addition to the field operations, numerals and case syntax are also
  1703 supported.
  1704 
  1705 * Theory Library/Diagonalize provides constructive version of Cantor's
  1706 first diagonalization argument.
  1707 
  1708 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1709 zlcm (for int); carried together from various gcd/lcm developements in
  1710 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1711 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1712 may recover tupled syntax as follows:
  1713 
  1714     hide (open) const gcd
  1715     abbreviation gcd where
  1716       "gcd == (%(a, b). GCD.gcd a b)"
  1717     notation (output)
  1718       GCD.gcd ("gcd '(_, _')")
  1719 
  1720 The same works for lcm, zgcd, zlcm.
  1721 
  1722 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1723 instantiations for algebraic structures.  Removed some duplicate
  1724 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1725 
  1726 * ML antiquotation @{code} takes a constant as argument and generates
  1727 corresponding code in background and inserts name of the corresponding
  1728 resulting ML value/function/datatype constructor binding in place.
  1729 All occurrences of @{code} with a single ML block are generated
  1730 simultaneously.  Provides a generic and safe interface for
  1731 instrumentalizing code generation.  See
  1732 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1733 In future you ought to refrain from ad-hoc compiling generated SML
  1734 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1735 cannot refer to constants for which user-defined serializations are
  1736 set.  Refer to the corresponding ML counterpart directly in that
  1737 cases.
  1738 
  1739 * Command 'rep_datatype': instead of theorem names the command now
  1740 takes a list of terms denoting the constructors of the type to be
  1741 represented as datatype.  The characteristic theorems have to be
  1742 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1743 have disappeared in favour of existing ones:
  1744 
  1745     unit_induct                 ~> unit.induct
  1746     prod_induct                 ~> prod.induct
  1747     sum_induct                  ~> sum.induct
  1748     Suc_Suc_eq                  ~> nat.inject
  1749     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1750 
  1751 
  1752 *** HOL-Algebra ***
  1753 
  1754 * New locales for orders and lattices where the equivalence relation
  1755 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1756 locales use a record structure with field eq for the equivalence.
  1757 
  1758 * New theory of factorial domains.
  1759 
  1760 * Units_l_inv and Units_r_inv are now simp rules by default.
  1761 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1762 and/or r_inv will now also require deletion of these lemmas.
  1763 
  1764 * Renamed the following theorems, INCOMPATIBILITY:
  1765 
  1766 UpperD ~> Upper_memD
  1767 LowerD ~> Lower_memD
  1768 least_carrier ~> least_closed
  1769 greatest_carrier ~> greatest_closed
  1770 greatest_Lower_above ~> greatest_Lower_below
  1771 one_zero ~> carrier_one_zero
  1772 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1773 
  1774 
  1775 *** HOL-Nominal ***
  1776 
  1777 * Nominal datatypes can now contain type-variables.
  1778 
  1779 * Commands 'nominal_inductive' and 'equivariance' work with local
  1780 theory targets.
  1781 
  1782 * Nominal primrec can now works with local theory targets and its
  1783 specification syntax now conforms to the general format as seen in
  1784 'inductive' etc.
  1785 
  1786 * Method "perm_simp" honours the standard simplifier attributes
  1787 (no_asm), (no_asm_use) etc.
  1788 
  1789 * The new predicate #* is defined like freshness, except that on the
  1790 left hand side can be a set or list of atoms.
  1791 
  1792 * Experimental command 'nominal_inductive2' derives strong induction
  1793 principles for inductive definitions.  In contrast to
  1794 'nominal_inductive', which can only deal with a fixed number of
  1795 binders, it can deal with arbitrary expressions standing for sets of
  1796 atoms to be avoided.  The only inductive definition we have at the
  1797 moment that needs this generalisation is the typing rule for Lets in
  1798 the algorithm W:
  1799 
  1800  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1801  -----------------------------------------------------------------
  1802          Gamma |- Let x be t1 in t2 : T2
  1803 
  1804 In this rule one wants to avoid all the binders that are introduced by
  1805 "close Gamma T1".  We are looking for other examples where this
  1806 feature might be useful.  Please let us know.
  1807 
  1808 
  1809 *** HOLCF ***
  1810 
  1811 * Reimplemented the simplification procedure for proving continuity
  1812 subgoals.  The new simproc is extensible; users can declare additional
  1813 continuity introduction rules with the attribute [cont2cont].
  1814 
  1815 * The continuity simproc now uses a different introduction rule for
  1816 solving continuity subgoals on terms with lambda abstractions.  In
  1817 some rare cases the new simproc may fail to solve subgoals that the
  1818 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1819 Potential INCOMPATIBILITY.
  1820 
  1821 * Command 'fixrec': specification syntax now conforms to the general
  1822 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1823 examples.  INCOMPATIBILITY.
  1824 
  1825 
  1826 *** ZF ***
  1827 
  1828 * Proof of Zorn's Lemma for partial orders.
  1829 
  1830 
  1831 *** ML ***
  1832 
  1833 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1834 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1835 depends on multithreading, so timouts will not work before Poly/ML
  1836 5.2.1!
  1837 
  1838 * High-level support for concurrent ML programming, see
  1839 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1840 particularly convenient to organize independent functional
  1841 computations.  The concept of "synchronized variables" provides a
  1842 higher-order interface for components with shared state, avoiding the
  1843 delicate details of mutexes and condition variables.  (Requires
  1844 Poly/ML 5.2.1 or later.)
  1845 
  1846 * ML bindings produced via Isar commands are stored within the Isar
  1847 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1848 become thread-safe and work with undo as expected (concerning
  1849 top-level bindings, not side-effects on global references).
  1850 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1851 compiler at runtime; really global bindings need to be given outside a
  1852 theory.  (Requires Poly/ML 5.2 or later.)
  1853 
  1854 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1855 context.  Top-level ML bindings are stored within the proof context in
  1856 a purely sequential fashion, disregarding the nested proof structure.
  1857 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1858 proof.  (Requires Poly/ML 5.2 or later.)
  1859 
  1860 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1861 and Method.setup, as well as Isar commands 'attribute_setup' and
  1862 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1863 existing code accordingly, or use plain 'setup' together with old
  1864 Method.add_method.
  1865 
  1866 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1867 to 'a -> thm, while results are always tagged with an authentic oracle
  1868 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1869 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1870 accordingly.  Note that extra performance may be gained by producing
  1871 the cterm carefully, avoiding slow Thm.cterm_of.
  1872 
  1873 * Simplified interface for defining document antiquotations via
  1874 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1875 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1876 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1877 examples.
  1878 
  1879 * More systematic treatment of long names, abstract name bindings, and
  1880 name space operations.  Basic operations on qualified names have been
  1881 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1882 Long_Name.append.  Old type bstring has been mostly replaced by
  1883 abstract type binding (see structure Binding), which supports precise
  1884 qualification by packages and local theory targets, as well as proper
  1885 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1886 bstring values into Binding.name, or better pass through abstract
  1887 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1888 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1889 
  1890 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1891 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1892 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1893 
  1894 * Disposed old type and term read functions (Sign.read_def_typ,
  1895 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1896 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1897 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1898 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1899 resort for legacy applications.
  1900 
  1901 * Disposed old declarations, tactics, tactic combinators that refer to
  1902 the simpset or claset of an implicit theory (such as Addsimps,
  1903 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1904 embedded ML text, or local_simpset_of with a proper context passed as
  1905 explicit runtime argument.
  1906 
  1907 * Rules and tactics that read instantiations (read_instantiate,
  1908 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1909 context, which is required for parsing and type-checking.  Moreover,
  1910 the variables are specified as plain indexnames, not string encodings
  1911 thereof.  INCOMPATIBILITY.
  1912 
  1913 * Generic Toplevel.add_hook interface allows to analyze the result of
  1914 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1915 for theorem dependency output of transactions resulting in a new
  1916 theory state.
  1917 
  1918 * ML antiquotations: block-structured compilation context indicated by
  1919 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1920 
  1921   @{binding name}                         - basic name binding
  1922   @{let ?pat = term}                      - term abbreviation (HO matching)
  1923   @{note name = fact}                     - fact abbreviation
  1924   @{thm fact}                             - singleton fact (with attributes)
  1925   @{thms fact}                            - general fact (with attributes)
  1926   @{lemma prop by method}                 - singleton goal
  1927   @{lemma prop by meth1 meth2}            - singleton goal
  1928   @{lemma prop1 ... propN by method}      - general goal
  1929   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1930   @{lemma (open) ...}                     - open derivation
  1931 
  1932 
  1933 *** System ***
  1934 
  1935 * The Isabelle "emacs" tool provides a specific interface to invoke
  1936 Proof General / Emacs, with more explicit failure if that is not
  1937 installed (the old isabelle-interface script silently falls back on
  1938 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1939 installation location of the Proof General distribution.
  1940 
  1941 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1942 the Isabelle process into a JVM/Scala application.  See
  1943 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1944 process wrapper has been discontinued.)
  1945 
  1946 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1947 
  1948 * Various status messages (with exact source position information) are
  1949 emitted, if proper markup print mode is enabled.  This allows
  1950 user-interface components to provide detailed feedback on internal
  1951 prover operations.
  1952 
  1953 
  1954 
  1955 New in Isabelle2008 (June 2008)
  1956 -------------------------------
  1957 
  1958 *** General ***
  1959 
  1960 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1961 and updated, with formally checked references as hyperlinks.
  1962 
  1963 * Theory loader: use_thy (and similar operations) no longer set the
  1964 implicit ML context, which was occasionally hard to predict and in
  1965 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1966 provides a proper context already.
  1967 
  1968 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1969 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1970 'use' within a theory file will do the job.
  1971 
  1972 * Name space merge now observes canonical order, i.e. the second space
  1973 is inserted into the first one, while existing entries in the first
  1974 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1975 swap theory imports.
  1976 
  1977 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1978 INCOMPATIBILITY in identifier syntax etc.
  1979 
  1980 * Outer syntax: string tokens no longer admit escaped white space,
  1981 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1982 white space without escapes.
  1983 
  1984 * Outer syntax: string tokens may contain arbitrary character codes
  1985 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1986 "foo_bar".
  1987 
  1988 
  1989 *** Pure ***
  1990 
  1991 * Context-dependent token translations.  Default setup reverts locally
  1992 fixed variables, and adds hilite markup for undeclared frees.
  1993 
  1994 * Unused theorems can be found using the new command 'unused_thms'.
  1995 There are three ways of invoking it:
  1996 
  1997 (1) unused_thms
  1998      Only finds unused theorems in the current theory.
  1999 
  2000 (2) unused_thms thy_1 ... thy_n -
  2001      Finds unused theorems in the current theory and all of its ancestors,
  2002      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2003 
  2004 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2005      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2006      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2007      their ancestors.
  2008 
  2009 In order to increase the readability of the list produced by
  2010 unused_thms, theorems that have been created by a particular instance
  2011 of a theory command such as 'inductive' or 'function' are considered
  2012 to belong to the same "group", meaning that if at least one theorem in
  2013 this group is used, the other theorems in the same group are no longer
  2014 reported as unused.  Moreover, if all theorems in the group are
  2015 unused, only one theorem in the group is displayed.
  2016 
  2017 Note that proof objects have to be switched on in order for
  2018 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2019 usually the case when using Proof General with the default settings).
  2020 
  2021 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2022 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2023 duplicate fact bindings, or even accidental fact duplications.  Note
  2024 that tools may maintain dynamically scoped facts systematically, using
  2025 PureThy.add_thms_dynamic.
  2026 
  2027 * Command 'hide' now allows to hide from "fact" name space as well.
  2028 
  2029 * Eliminated destructive theorem database, simpset, claset, and
  2030 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2031 update of theories within ML code.
  2032 
  2033 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2034 INCOMPATIBILITY, object-logics depending on former Pure require
  2035 additional setup PureThy.old_appl_syntax_setup; object-logics
  2036 depending on former CPure need to refer to Pure.
  2037 
  2038 * Commands 'use' and 'ML' are now purely functional, operating on
  2039 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2040 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2041 INCOMPATIBILITY.
  2042 
  2043 * Command 'setup': discontinued implicit version with ML reference.
  2044 
  2045 * Instantiation target allows for simultaneous specification of class
  2046 instance operations together with an instantiation proof.
  2047 Type-checking phase allows to refer to class operations uniformly.
  2048 See src/HOL/Complex/Complex.thy for an Isar example and
  2049 src/HOL/Library/Eval.thy for an ML example.
  2050 
  2051 * Indexing of literal facts: be more serious about including only
  2052 facts from the visible specification/proof context, but not the
  2053 background context (locale etc.).  Affects `prop` notation and method
  2054 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2055 situations.
  2056 
  2057 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2058 "(open)" option, which used to expose internal bound variables to the
  2059 proof text.
  2060 
  2061 * Isar statements: removed obsolete case "rule_context".
  2062 INCOMPATIBILITY, better use explicit fixes/assumes.
  2063 
  2064 * Locale proofs: default proof step now includes 'unfold_locales';
  2065 hence 'proof' without argument may be used to unfold locale
  2066 predicates.
  2067 
  2068 
  2069 *** Document preparation ***
  2070 
  2071 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2072 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2073 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2074 spot); renamed link color from "darkblue" to "linkcolor" (default
  2075 value unchanged, can be redefined via \definecolor); no longer sets
  2076 "a4paper" option (unnecessary or even intrusive).
  2077 
  2078 * Antiquotation @{lemma A method} proves proposition A by the given
  2079 method (either a method name or a method name plus (optional) method
  2080 arguments in parentheses) and prints A just like @{prop A}.
  2081 
  2082 
  2083 *** HOL ***
  2084 
  2085 * New primrec package.  Specification syntax conforms in style to
  2086 definition/function/....  No separate induction rule is provided.  The
  2087 "primrec" command distinguishes old-style and new-style specifications
  2088 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2089 When adjusting theories, beware: constants stemming from new-style
  2090 primrec specifications have authentic syntax.
  2091 
  2092 * Metis prover is now an order of magnitude faster, and also works
  2093 with multithreading.
  2094 
  2095 * Metis: the maximum number of clauses that can be produced from a
  2096 theorem is now given by the attribute max_clauses.  Theorems that
  2097 exceed this number are ignored, with a warning printed.
  2098 
  2099 * Sledgehammer no longer produces structured proofs by default. To
  2100 enable, declare [[sledgehammer_full = true]].  Attributes
  2101 reconstruction_modulus, reconstruction_sorts renamed
  2102 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2103 
  2104 * Method "induct_scheme" derives user-specified induction rules
  2105 from well-founded induction and completeness of patterns. This factors
  2106 out some operations that are done internally by the function package
  2107 and makes them available separately.  See
  2108 src/HOL/ex/Induction_Scheme.thy for examples.
  2109 
  2110 * More flexible generation of measure functions for termination
  2111 proofs: Measure functions can be declared by proving a rule of the
  2112 form "is_measure f" and giving it the [measure_function] attribute.
  2113 The "is_measure" predicate is logically meaningless (always true), and
  2114 just guides the heuristic.  To find suitable measure functions, the
  2115 termination prover sets up the goal "is_measure ?f" of the appropriate
  2116 type and generates all solutions by prolog-style backwards proof using
  2117 the declared rules.
  2118 
  2119 This setup also deals with rules like 
  2120 
  2121   "is_measure f ==> is_measure (list_size f)"
  2122 
  2123 which accommodates nested datatypes that recurse through lists.
  2124 Similar rules are predeclared for products and option types.
  2125 
  2126 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2127 
  2128   INCOMPATIBILITIES:
  2129 
  2130   - Definitions of overloaded constants on sets have to be replaced by
  2131     definitions on => and bool.
  2132 
  2133   - Some definitions of overloaded operators on sets can now be proved
  2134     using the definitions of the operators on => and bool.  Therefore,
  2135     the following theorems have been renamed:
  2136 
  2137       subset_def   -> subset_eq
  2138       psubset_def  -> psubset_eq
  2139       set_diff_def -> set_diff_eq
  2140       Compl_def    -> Compl_eq
  2141       Sup_set_def  -> Sup_set_eq
  2142       Inf_set_def  -> Inf_set_eq
  2143       sup_set_def  -> sup_set_eq
  2144       inf_set_def  -> inf_set_eq
  2145 
  2146   - Due to the incompleteness of the HO unification algorithm, some
  2147     rules such as subst may require manual instantiation, if some of
  2148     the unknowns in the rule is a set.
  2149 
  2150   - Higher order unification and forward proofs:
  2151     The proof pattern
  2152 
  2153       have "P (S::'a set)" <...>
  2154       then have "EX S. P S" ..
  2155 
  2156     no longer works (due to the incompleteness of the HO unification
  2157     algorithm) and must be replaced by the pattern
  2158 
  2159       have "EX S. P S"
  2160       proof
  2161         show "P S" <...>
  2162       qed
  2163 
  2164   - Calculational reasoning with subst (or similar rules):
  2165     The proof pattern
  2166 
  2167       have "P (S::'a set)" <...>
  2168       also have "S = T" <...>
  2169       finally have "P T" .
  2170 
  2171     no longer works (for similar reasons as the previous example) and
  2172     must be replaced by something like
  2173 
  2174       have "P (S::'a set)" <...>
  2175       moreover have "S = T" <...>
  2176       ultimately have "P T" by simp
  2177 
  2178   - Tactics or packages written in ML code:
  2179     Code performing pattern matching on types via
  2180 
  2181       Type ("set", [T]) => ...
  2182 
  2183     must be rewritten. Moreover, functions like strip_type or
  2184     binder_types no longer return the right value when applied to a
  2185     type of the form
  2186 
  2187       T1 => ... => Tn => U => bool
  2188 
  2189     rather than
  2190 
  2191       T1 => ... => Tn => U set
  2192 
  2193 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2194 Wellfounded_Relations to theory Wellfounded.
  2195 
  2196 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2197 
  2198 * Class finite no longer treats UNIV as class parameter.  Use class
  2199 enum from theory Library/Enum instead to achieve a similar effect.
  2200 INCOMPATIBILITY.
  2201 
  2202 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2203 and "Cons".  INCOMPATIBILITY.
  2204 
  2205 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2206 Potential INCOMPATIBILITY.
  2207 
  2208 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2209 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2210 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2211 
  2212 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2213 the same name in theory Orderings:
  2214 
  2215   less_trans
  2216   less_linear
  2217   le_imp_less_or_eq
  2218   le_less_trans
  2219   less_le_trans
  2220   less_not_sym
  2221   less_asym
  2222 
  2223 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2224 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2225 and different variable names.
  2226 
  2227 * Library/Option_ord.thy: Canonical order on option type.
  2228 
  2229 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2230 finite maps.
  2231 
  2232 * Library/Countable.thy: Type class for countable types.
  2233 
  2234 * Theory Int: The representation of numerals has changed.  The infix
  2235 operator BIT and the bit datatype with constructors B0 and B1 have
  2236 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2237 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2238 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2239 accordingly.
  2240 
  2241 * Theory Nat: definition of <= and < on natural numbers no longer
  2242 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2243 le_def and less_def have disappeared.  Consider lemmas not_less
  2244 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2245 
  2246 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2247 (whose purpose mainly is for various fold_set functionals) have been
  2248 abandoned in favor of the existing algebraic classes
  2249 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2250 lower_semilattice (resp. upper_semilattice) and linorder.
  2251 INCOMPATIBILITY.
  2252 
  2253 * Theory Transitive_Closure: induct and cases rules now declare proper
  2254 case_names ("base" and "step").  INCOMPATIBILITY.
  2255 
  2256 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2257 lattices.  The form set-specific version is available as
  2258 Inductive.lfp_ordinal_induct_set.
  2259 
  2260 * Renamed theorems "power.simps" to "power_int.simps".
  2261 INCOMPATIBILITY.
  2262 
  2263 * Class semiring_div provides basic abstract properties of semirings
  2264 with division and modulo operations.  Subsumes former class dvd_mod.
  2265 
  2266 * Merged theories IntDef, Numeral and IntArith into unified theory
  2267 Int.  INCOMPATIBILITY.
  2268 
  2269 * Theory Library/Code_Index: type "index" now represents natural
  2270 numbers rather than integers.  INCOMPATIBILITY.
  2271 
  2272 * New class "uminus" with operation "uminus" (split of from class
  2273 "minus" which now only has operation "minus", binary).
  2274 INCOMPATIBILITY.
  2275 
  2276 * Constants "card", "internal_split", "option_map" now with authentic
  2277 syntax.  INCOMPATIBILITY.
  2278 
  2279 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2280 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2281 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2282 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2283 Sup_set_def, le_def, less_def, option_map_def now with object
  2284 equality.  INCOMPATIBILITY.
  2285 
  2286 * Records. Removed K_record, and replaced it by pure lambda term
  2287 %x. c. The simplifier setup is now more robust against eta expansion.
  2288 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2289 
  2290 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2291 
  2292 * Library/ListVector: new theory of arithmetic vector operations.
  2293 
  2294 * Library/Order_Relation: new theory of various orderings as sets of
  2295 pairs.  Defines preorders, partial orders, linear orders and
  2296 well-orders on sets and on types.
  2297 
  2298 
  2299 *** ZF ***
  2300 
  2301 * Renamed some theories to allow to loading both ZF and HOL in the
  2302 same session:
  2303 
  2304   Datatype  -> Datatype_ZF
  2305   Inductive -> Inductive_ZF
  2306   Int       -> Int_ZF
  2307   IntDiv    -> IntDiv_ZF
  2308   Nat       -> Nat_ZF
  2309   List      -> List_ZF
  2310   Main      -> Main_ZF
  2311 
  2312 INCOMPATIBILITY: ZF theories that import individual theories below
  2313 Main might need to be adapted.  Regular theory Main is still
  2314 available, as trivial extension of Main_ZF.
  2315 
  2316 
  2317 *** ML ***
  2318 
  2319 * ML within Isar: antiquotation @{const name} or @{const
  2320 name(typargs)} produces statically-checked Const term.
  2321 
  2322 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2323 (of the same name).  Removed obsolete print command.
  2324 
  2325 * Removed obsolete "use_legacy_bindings" function.
  2326 
  2327 * The ``print mode'' is now a thread-local value derived from a global
  2328 template (the former print_mode reference), thus access becomes
  2329 non-critical.  The global print_mode reference is for session
  2330 management only; user-code should use print_mode_value,
  2331 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2332 
  2333 * Functions system/system_out provide a robust way to invoke external
  2334 shell commands, with propagation of interrupts (requires Poly/ML
  2335 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2336 
  2337 
  2338 *** System ***
  2339 
  2340 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2341 in accordance with Proof General 3.7, which prefers GNU emacs.
  2342 
  2343 * isatool tty runs Isabelle process with plain tty interaction;
  2344 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2345 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2346 
  2347 * isatool browser now works with Cygwin as well, using general
  2348 "javapath" function defined in Isabelle process environment.
  2349 
  2350 * YXML notation provides a simple and efficient alternative to
  2351 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2352 isatool yxml as described in the Isabelle system manual.
  2353 
  2354 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2355 provides general wrapper for managing an Isabelle process in a robust
  2356 fashion, with ``cooked'' output from stdin/stderr.
  2357 
  2358 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2359 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2360 
  2361 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2362 way of changing the user's settings is via
  2363 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2364 script.
  2365 
  2366 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2367 cores of the underlying machine, which is a good starting point for
  2368 optimal performance tuning.  The corresponding usedir option -M allows
  2369 "max" as an alias for "0".  WARNING: does not work on certain versions
  2370 of Mac OS (with Poly/ML 5.1).
  2371 
  2372 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2373 adverse effect of Isabelle flooding interactive front-ends (notably
  2374 ProofGeneral / XEmacs).
  2375 
  2376 
  2377 
  2378 New in Isabelle2007 (November 2007)
  2379 -----------------------------------
  2380 
  2381 *** General ***
  2382 
  2383 * More uniform information about legacy features, notably a
  2384 warning/error of "Legacy feature: ...", depending on the state of the
  2385 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2386 legacy features will disappear eventually.
  2387 
  2388 * Theory syntax: the header format ``theory A = B + C:'' has been
  2389 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2390 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2391 
  2392 * Theory syntax: the old non-Isar theory file format has been
  2393 discontinued altogether.  Note that ML proof scripts may still be used
  2394 with Isar theories; migration is usually quite simple with the ML
  2395 function use_legacy_bindings.  INCOMPATIBILITY.
  2396 
  2397 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2398 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2399 quotes.
  2400 
  2401 * Theory loader: be more serious about observing the static theory
  2402 header specifications (including optional directories), but not the
  2403 accidental file locations of previously successful loads.  The strict
  2404 update policy of former update_thy is now already performed by
  2405 use_thy, so the former has been removed; use_thys updates several
  2406 theories simultaneously, just as 'imports' within a theory header
  2407 specification, but without merging the results.  Potential
  2408 INCOMPATIBILITY: may need to refine theory headers and commands
  2409 ROOT.ML which depend on load order.
  2410 
  2411 * Theory loader: optional support for content-based file
  2412 identification, instead of the traditional scheme of full physical
  2413 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2414 (cf. the system manual).  The new scheme allows to work with
  2415 non-finished theories in persistent session images, such that source
  2416 files may be moved later on without requiring reloads.
  2417 
  2418 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2419 file (with the same base name as the theory) are considered a legacy
  2420 feature, which will disappear eventually. Even now, the theory loader
  2421 no longer maintains dependencies on such files.
  2422 
  2423 * Syntax: the scope for resolving ambiguities via type-inference is
  2424 now limited to individual terms, instead of whole simultaneous
  2425 specifications as before. This greatly reduces the complexity of the
  2426 syntax module and improves flexibility by separating parsing and
  2427 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2428 'fixes' etc.) are required in rare situations.
  2429 
  2430 * Syntax: constants introduced by new-style packages ('definition',
  2431 'abbreviation' etc.) are passed through the syntax module in
  2432 ``authentic mode''. This means that associated mixfix annotations
  2433 really stick to such constants, independently of potential name space
  2434 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2435 trees are represented slightly differently, may need to adapt syntax
  2436 translations accordingly. Use CONST marker in 'translations' and
  2437 @{const_syntax} antiquotation in 'parse_translation' etc.
  2438 
  2439 * Legacy goal package: reduced interface to the bare minimum required
  2440 to keep existing proof scripts running.  Most other user-level
  2441 functions are now part of the OldGoals structure, which is *not* open
  2442 by default (consider isatool expandshort before open OldGoals).
  2443 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2444 these tend to cause confusion about the actual goal (!) context being
  2445 used here, which is not necessarily the same as the_context().
  2446 
  2447 * Command 'find_theorems': supports "*" wild-card in "name:"
  2448 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2449 support a specific search form (see ProofGeneral/CHANGES).
  2450 
  2451 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2452 by default, which means that "prems" (and also "fixed variables") are
  2453 suppressed from proof state output.  Note that the ProofGeneral
  2454 settings mechanism allows to change and save options persistently, but
  2455 older versions of Isabelle will fail to start up if a negative prems
  2456 limit is imposed.
  2457 
  2458 * Local theory targets may be specified by non-nested blocks of
  2459 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2460 contain definitions, theorems etc., including any derived mechanism
  2461 that has been implemented on top of these primitives.  This concept
  2462 generalizes the existing ``theorem (in ...)'' towards more versatility
  2463 and scalability.
  2464 
  2465 * Proof General interface: proper undo of final 'end' command;
  2466 discontinued Isabelle/classic mode (ML proof scripts).
  2467 
  2468 
  2469 *** Document preparation ***
  2470 
  2471 * Added antiquotation @{theory name} which prints the given name,
  2472 after checking that it refers to a valid ancestor theory in the
  2473 current context.
  2474 
  2475 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2476 check the given source text as ML type/structure, printing verbatim.
  2477 
  2478 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2479 "c args == rhs" given in the current context.  (Any number of
  2480 arguments may be given on the LHS.)
  2481 
  2482 
  2483 *** Pure ***
  2484 
  2485 * The 'class' package offers a combination of axclass and locale to
  2486 achieve Haskell-like type classes in Isabelle.  Definitions and
  2487 theorems within a class context produce both relative results (with
  2488 implicit parameters according to the locale context), and polymorphic
  2489 constants with qualified polymorphism (according to the class
  2490 context).  Within the body context of a 'class' target, a separate
  2491 syntax layer ("user space type system") takes care of converting
  2492 between global polymorphic consts and internal locale representation.
  2493 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2494 "isatool doc classes" provides a tutorial.
  2495 
  2496 * Generic code generator framework allows to generate executable
  2497 code for ML and Haskell (including Isabelle classes).  A short usage
  2498 sketch:
  2499 
  2500     internal compilation:
  2501         export_code <list of constants (term syntax)> in SML
  2502     writing SML code to a file:
  2503         export_code <list of constants (term syntax)> in SML <filename>
  2504     writing OCaml code to a file:
  2505         export_code <list of constants (term syntax)> in OCaml <filename>
  2506     writing Haskell code to a bunch of files:
  2507         export_code <list of constants (term syntax)> in Haskell <filename>
  2508 
  2509     evaluating closed propositions to True/False using code generation:
  2510         method ``eval''
  2511 
  2512 Reasonable default setup of framework in HOL.
  2513 
  2514 Theorem attributs for selecting and transforming function equations theorems:
  2515 
  2516     [code fun]:        select a theorem as function equation for a specific constant
  2517     [code fun del]:    deselect a theorem as function equation for a specific constant
  2518     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2519     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2520 
  2521 User-defined serializations (target in {SML, OCaml, Haskell}):
  2522 
  2523     code_const <and-list of constants (term syntax)>
  2524       {(target) <and-list of const target syntax>}+
  2525 
  2526     code_type <and-list of type constructors>
  2527       {(target) <and-list of type target syntax>}+
  2528 
  2529     code_instance <and-list of instances>
  2530       {(target)}+
  2531         where instance ::= <type constructor> :: <class>
  2532 
  2533     code_class <and_list of classes>
  2534       {(target) <and-list of class target syntax>}+
  2535         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2536 
  2537 code_instance and code_class only are effective to target Haskell.
  2538 
  2539 For example usage see src/HOL/ex/Codegenerator.thy and
  2540 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2541 generation from Isabelle/HOL theories is available via "isatool doc
  2542 codegen".
  2543 
  2544 * Code generator: consts in 'consts_code' Isar commands are now
  2545 referred to by usual term syntax (including optional type
  2546 annotations).
  2547 
  2548 * Command 'no_translations' removes translation rules from theory
  2549 syntax.
  2550 
  2551 * Overloaded definitions are now actually checked for acyclic
  2552 dependencies.  The overloading scheme is slightly more general than
  2553 that of Haskell98, although Isabelle does not demand an exact
  2554 correspondence to type class and instance declarations.
  2555 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2556 exotic versions of overloading -- at the discretion of the user!
  2557 
  2558 Polymorphic constants are represented via type arguments, i.e. the
  2559 instantiation that matches an instance against the most general
  2560 declaration given in the signature.  For example, with the declaration
  2561 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2562 as c(nat).  Overloading is essentially simultaneous structural
  2563 recursion over such type arguments.  Incomplete specification patterns
  2564 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2565 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2566 Command 'print_theory' outputs the normalized system of recursive
  2567 equations, see section "definitions".
  2568 
  2569 * Configuration options are maintained within the theory or proof
  2570 context (with name and type bool/int/string), providing a very simple
  2571 interface to a poor-man's version of general context data.  Tools may
  2572 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2573 these values using Config.get etc.  Users may change options via an
  2574 associated attribute of the same name.  This form of context
  2575 declaration works particularly well with commands 'declare' or
  2576 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2577 very easy to avoid global references, which would not observe Isar
  2578 toplevel undo/redo and fail to work with multithreading.
  2579 
  2580 Various global ML references of Pure and HOL have been turned into
  2581 configuration options:
  2582 
  2583   Unify.search_bound		unify_search_bound
  2584   Unify.trace_bound		unify_trace_bound
  2585   Unify.trace_simp		unify_trace_simp
  2586   Unify.trace_types		unify_trace_types
  2587   Simplifier.simp_depth_limit	simp_depth_limit
  2588   Blast.depth_limit		blast_depth_limit
  2589   DatatypeProp.dtK		datatype_distinctness_limit
  2590   fast_arith_neq_limit  	fast_arith_neq_limit
  2591   fast_arith_split_limit	fast_arith_split_limit
  2592 
  2593 * Named collections of theorems may be easily installed as context
  2594 data using the functor NamedThmsFun (see also
  2595 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2596 attributes; there is also a toplevel print command.  This facility is
  2597 just a common case of general context data, which is the preferred way
  2598 for anything more complex than just a list of facts in canonical
  2599 order.
  2600 
  2601 * Isar: command 'declaration' augments a local theory by generic
  2602 declaration functions written in ML.  This enables arbitrary content
  2603 being added to the context, depending on a morphism that tells the
  2604 difference of the original declaration context wrt. the application
  2605 context encountered later on.
  2606 
  2607 * Isar: proper interfaces for simplification procedures.  Command
  2608 'simproc_setup' declares named simprocs (with match patterns, and body
  2609 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2610 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2611 
  2612 * Isar: an extra pair of brackets around attribute declarations
  2613 abbreviates a theorem reference involving an internal dummy fact,
  2614 which will be ignored later --- only the effect of the attribute on
  2615 the background context will persist.  This form of in-place
  2616 declarations is particularly useful with commands like 'declare' and
  2617 'using', for example ``have A using [[simproc a]] by simp''.
  2618 
  2619 * Isar: method "assumption" (and implicit closing of subproofs) now
  2620 takes simple non-atomic goal assumptions into account: after applying
  2621 an assumption as a rule the resulting subgoals are solved by atomic
  2622 assumption steps.  This is particularly useful to finish 'obtain'
  2623 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2624 without referring to the original premise "!!x. P x ==> thesis" in the
  2625 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2626 more permissive.
  2627 
  2628 * Isar: implicit use of prems from the Isar proof context is
  2629 considered a legacy feature.  Common applications like ``have A .''
  2630 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2631 referencing facts explicitly here improves readability and
  2632 maintainability of proof texts.
  2633 
  2634 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2635 the obtained context from the course of reasoning!  For example:
  2636 
  2637   assume "EX x y. A x & B y"   -- "any previous fact"
  2638   then guess x and y by clarify
  2639 
  2640 This technique is potentially adventurous, depending on the facts and
  2641 proof tools being involved here.
  2642 
  2643 * Isar: known facts from the proof context may be specified as literal
  2644 propositions, using ASCII back-quote syntax.  This works wherever
  2645 named facts used to be allowed so far, in proof commands, proof
  2646 methods, attributes etc.  Literal facts are retrieved from the context
  2647 according to unification of type and term parameters.  For example,
  2648 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2649 theorems in the current context, then these are valid literal facts:
  2650 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2651 
  2652 There is also a proof method "fact" which does the same composition
  2653 for explicit goal states, e.g. the following proof texts coincide with
  2654 certain special cases of literal facts:
  2655 
  2656   have "A" by fact                 ==  note `A`
  2657   have "A ==> B" by fact           ==  note `A ==> B`
  2658   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2659   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2660 
  2661 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2662 outer syntax.  Thus symbolic identifiers may be used without
  2663 additional white space in declarations like this: ``assume *: A''.
  2664 
  2665 * Isar: 'print_facts' prints all local facts of the current context,
  2666 both named and unnamed ones.
  2667 
  2668 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2669 
  2670   def x == "t" and y == "u"
  2671 
  2672 * Isar: added command 'unfolding', which is structurally similar to
  2673 'using', but affects both the goal state and facts by unfolding given
  2674 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2675 'unfolded' attribute may be replaced by first-class proof text.
  2676 
  2677 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2678 and command 'unfolding' now all support object-level equalities
  2679 (potentially conditional).  The underlying notion of rewrite rule is
  2680 analogous to the 'rule_format' attribute, but *not* that of the
  2681 Simplifier (which is usually more generous).
  2682 
  2683 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2684 premises of a theorem by n. Useful in conjunction with drule.
  2685 
  2686 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2687 method expression within a sandbox consisting of the first N
  2688 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2689 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2690 simplifies all new goals that emerge from applying rule foo to the
  2691 originally first one.
  2692 
  2693 * Isar: schematic goals are no longer restricted to higher-order
  2694 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2695 expected.
  2696 
  2697 * Isar: the conclusion of a long theorem statement is now either
  2698 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2699 (essentially a disjunction of cases with local parameters and
  2700 assumptions).  The latter allows to express general elimination rules
  2701 adequately; in this notation common elimination rules look like this:
  2702 
  2703   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2704     assumes "EX x. P x"
  2705     obtains x where "P x"
  2706 
  2707   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2708     assumes "A & B"
  2709     obtains A and B
  2710 
  2711   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2712     assumes "A | B"
  2713     obtains
  2714       A
  2715     | B
  2716 
  2717 The subsequent classical rules even refer to the formal "thesis"
  2718 explicitly:
  2719 
  2720   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2721     obtains "~ thesis"
  2722 
  2723   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2724     obtains "thesis ==> something"
  2725 
  2726 The actual proof of an 'obtains' statement is analogous to that of the
  2727 Isar proof element 'obtain', only that there may be several cases.
  2728 Optional case names may be specified in parentheses; these will be
  2729 available both in the present proof and as annotations in the
  2730 resulting rule, for later use with the 'cases' method (cf. attribute
  2731 case_names).
  2732 
  2733 * Isar: the assumptions of a long theorem statement are available as
  2734 "assms" fact in the proof context.  This is more appropriate than the
  2735 (historical) "prems", which refers to all assumptions of the current
  2736 context, including those from the target locale, proof body etc.
  2737 
  2738 * Isar: 'print_statement' prints theorems from the current theory or
  2739 proof context in long statement form, according to the syntax of a
  2740 top-level lemma.
  2741 
  2742 * Isar: 'obtain' takes an optional case name for the local context
  2743 introduction rule (default "that").
  2744 
  2745 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2746 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2747 to occur.
  2748 
  2749 * Pure: syntax "CONST name" produces a fully internalized constant
  2750 according to the current context.  This is particularly useful for
  2751 syntax translations that should refer to internal constant
  2752 representations independently of name spaces.
  2753 
  2754 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2755 instead of "FOO ". This allows multiple binder declarations to coexist
  2756 in the same context.  INCOMPATIBILITY.
  2757 
  2758 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2759 primitive that also works in a locale context (both for constants and
  2760 fixed variables). Type declaration and internal syntactic representation
  2761 of given constants retrieved from the context. Likewise, the
  2762 'no_notation' command allows to remove given syntax annotations from the
  2763 current context.
  2764 
  2765 * Isar/locales: new derived specification elements 'axiomatization',
  2766 'definition', 'abbreviation', which support type-inference, admit
  2767 object-level specifications (equality, equivalence).  See also the
  2768 isar-ref manual.  Examples:
  2769 
  2770   axiomatization
  2771     eq  (infix "===" 50) where
  2772     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2773 
  2774   definition "f x y = x + y + 1"
  2775   definition g where "g x = f x x"
  2776 
  2777   abbreviation
  2778     neq  (infix "=!=" 50) where
  2779     "x =!= y == ~ (x === y)"
  2780 
  2781 These specifications may be also used in a locale context.  Then the
  2782 constants being introduced depend on certain fixed parameters, and the
  2783 constant name is qualified by the locale base name.  An internal
  2784 abbreviation takes care for convenient input and output, making the
  2785 parameters implicit and using the original short name.  See also
  2786 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2787 entities from a monomorphic theory.
  2788 
  2789 Presently, abbreviations are only available 'in' a target locale, but
  2790 not inherited by general import expressions.  Also note that
  2791 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2792 'translations' in common applications.  The "no_abbrevs" print mode
  2793 prevents folding of abbreviations in term output.
  2794 
  2795 Concrete syntax is attached to specified constants in internal form,
  2796 independently of name spaces.  The parse tree representation is
  2797 slightly different -- use 'notation' instead of raw 'syntax', and
  2798 'translations' with explicit "CONST" markup to accommodate this.
  2799 
  2800 * Pure/Isar: unified syntax for new-style specification mechanisms
  2801 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2802 full type inference and dummy patterns ("_").  For example:
  2803 
  2804   definition "K x _ = x"
  2805 
  2806   inductive conj for A B
  2807   where "A ==> B ==> conj A B"
  2808 
  2809 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2810 the current context.  Print mode "no_abbrevs" prevents inversion of
  2811 abbreviations on output.
  2812 
  2813 * Isar/locales: improved parameter handling: use of locales "var" and
  2814 "struct" no longer necessary; - parameter renamings are no longer
  2815 required to be injective.  For example, this allows to define
  2816 endomorphisms as locale endom = homom mult mult h.
  2817 
  2818 * Isar/locales: changed the way locales with predicates are defined.
  2819 Instead of accumulating the specification, the imported expression is
  2820 now an interpretation.  INCOMPATIBILITY: different normal form of
  2821 locale expressions.  In particular, in interpretations of locales with
  2822 predicates, goals repesenting already interpreted fragments are not
  2823 removed automatically.  Use methods `intro_locales' and
  2824 `unfold_locales'; see below.
  2825 
  2826 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2827 provide backward reasoning on locales predicates.  The methods are
  2828 aware of interpretations and discharge corresponding goals.
  2829 `intro_locales' is less aggressive then `unfold_locales' and does not
  2830 unfold predicates to assumptions.
  2831 
  2832 * Isar/locales: the order in which locale fragments are accumulated
  2833 has changed.  This enables to override declarations from fragments due
  2834 to interpretations -- for example, unwanted simp rules.
  2835 
  2836 * Isar/locales: interpretation in theories and proof contexts has been
  2837 extended.  One may now specify (and prove) equations, which are
  2838 unfolded in interpreted theorems.  This is useful for replacing
  2839 defined concepts (constants depending on locale parameters) by
  2840 concepts already existing in the target context.  Example:
  2841 
  2842   interpretation partial_order ["op <= :: [int, int] => bool"]
  2843     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2844 
  2845 Typically, the constant `partial_order.less' is created by a
  2846 definition specification element in the context of locale
  2847 partial_order.
  2848 
  2849 * Method "induct": improved internal context management to support
  2850 local fixes and defines on-the-fly. Thus explicit meta-level
  2851 connectives !!  and ==> are rarely required anymore in inductive goals
  2852 (using object-logic connectives for this purpose has been long
  2853 obsolete anyway). Common proof patterns are explained in
  2854 src/HOL/Induct/Common_Patterns.thy, see also
  2855 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2856 examples.
  2857 
  2858 * Method "induct": improved handling of simultaneous goals. Instead of
  2859 introducing object-level conjunction, the statement is now split into
  2860 several conclusions, while the corresponding symbolic cases are nested
  2861 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2862 see src/HOL/Induct/Common_Patterns.thy, for example.
  2863 
  2864 * Method "induct": mutual induction rules are now specified as a list
  2865 of rule sharing the same induction cases. HOL packages usually provide
  2866 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2867 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2868 mutual induction rules differently, i.e. like this:
  2869 
  2870   (induct rule: foo_bar.inducts)
  2871   (induct set: foo bar)
  2872   (induct pred: foo bar)
  2873   (induct type: foo bar)
  2874 
  2875 The ML function ProjectRule.projections turns old-style rules into the
  2876 new format.
  2877 
  2878 * Method "coinduct": dual of induction, see
  2879 src/HOL/Library/Coinductive_List.thy for various examples.
  2880 
  2881 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2882 considered a legacy feature.
  2883 
  2884 * Attribute "symmetric" produces result with standardized schematic
  2885 variables (index 0).  Potential INCOMPATIBILITY.
  2886 
  2887 * Simplifier: by default the simplifier trace only shows top level
  2888 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2889 default. Thus there is less danger of being flooded by the trace. The
  2890 trace indicates where parts have been suppressed.
  2891   
  2892 * Provers/classical: removed obsolete classical version of elim_format
  2893 attribute; classical elim/dest rules are now treated uniformly when
  2894 manipulating the claset.
  2895 
  2896 * Provers/classical: stricter checks to ensure that supplied intro,
  2897 dest and elim rules are well-formed; dest and elim rules must have at
  2898 least one premise.
  2899 
  2900 * Provers/classical: attributes dest/elim/intro take an optional
  2901 weight argument for the rule (just as the Pure versions).  Weights are
  2902 ignored by automated tools, but determine the search order of single
  2903 rule steps.
  2904 
  2905 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2906 where the body does not mention the bound variable.  Note that dummy
  2907 patterns implicitly depend on their context of bounds, which makes
  2908 "{_. _}" match any set comprehension as expected.  Potential
  2909 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2910 constant "_idtdummy" in the binding position.
  2911 
  2912 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2913 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2914 for example "A -> B" => "Pi A (%_. B)".
  2915 
  2916 * Pure: 'class_deps' command visualizes the subclass relation, using
  2917 the graph browser tool.
  2918 
  2919 * Pure: 'print_theory' now suppresses certain internal declarations by
  2920 default; use '!' option for full details.
  2921 
  2922 
  2923 *** HOL ***
  2924 
  2925 * Method "metis" proves goals by applying the Metis general-purpose
  2926 resolution prover (see also http://gilith.com/software/metis/).
  2927 Examples are in the directory MetisExamples.  WARNING: the
  2928 Isabelle/HOL-Metis integration does not yet work properly with
  2929 multi-threading.
  2930   
  2931 * Command 'sledgehammer' invokes external automatic theorem provers as
  2932 background processes.  It generates calls to the "metis" method if
  2933 successful. These can be pasted into the proof.  Users do not have to
  2934 wait for the automatic provers to return.  WARNING: does not really
  2935 work with multi-threading.
  2936 
  2937 * New "auto_quickcheck" feature tests outermost goal statements for
  2938 potential counter-examples.  Controlled by ML references
  2939 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2940 5000 milliseconds).  Fails silently if statements is outside of
  2941 executable fragment, or any other codgenerator problem occurs.
  2942 
  2943 * New constant "undefined" with axiom "undefined x = undefined".
  2944 
  2945 * Added class "HOL.eq", allowing for code generation with polymorphic
  2946 equality.
  2947 
  2948 * Some renaming of class constants due to canonical name prefixing in
  2949 the new 'class' package:
  2950 
  2951     HOL.abs ~> HOL.abs_class.abs
  2952     HOL.divide ~> HOL.divide_class.divide
  2953     0 ~> HOL.zero_class.zero
  2954     1 ~> HOL.one_class.one
  2955     op + ~> HOL.plus_class.plus
  2956     op - ~> HOL.minus_class.minus
  2957     uminus ~> HOL.minus_class.uminus
  2958     op * ~> HOL.times_class.times
  2959     op < ~> HOL.ord_class.less
  2960     op <= > HOL.ord_class.less_eq
  2961     Nat.power ~> Power.power_class.power
  2962     Nat.size ~> Nat.size_class.size
  2963     Numeral.number_of ~> Numeral.number_class.number_of
  2964     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2965     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2966     Orderings.min ~> Orderings.ord_class.min
  2967     Orderings.max ~> Orderings.ord_class.max
  2968     Divides.op div ~> Divides.div_class.div
  2969     Divides.op mod ~> Divides.div_class.mod
  2970     Divides.op dvd ~> Divides.div_class.dvd
  2971 
  2972 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2973 
  2974 a) User-defined constants using any of the names "plus", "minus",
  2975 "times", "less" or "less_eq". The standard syntax translations for
  2976 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2977 names.
  2978 
  2979 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2980 INCOMPATIBILITY: use more specific names.
  2981 
  2982 c) Permutative equations (e.g. "a + b = b + a")
  2983 Since the change of names also changes the order of terms, permutative
  2984 rewrite rules may get applied in a different order. Experience shows
  2985 that this is rarely the case (only two adaptions in the whole Isabelle
  2986 distribution).  INCOMPATIBILITY: rewrite proofs
  2987 
  2988 d) ML code directly refering to constant names
  2989 This in general only affects hand-written proof tactics, simprocs and
  2990 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2991 Consider using @{const_name} antiquotation.
  2992 
  2993 * New class "default" with associated constant "default".
  2994 
  2995 * Function "sgn" is now overloaded and available on int, real, complex
  2996 (and other numeric types), using class "sgn".  Two possible defs of
  2997 sgn are given as equational assumptions in the classes sgn_if and
  2998 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2999 INCOMPATIBILITY.
  3000 
  3001 * Locale "partial_order" now unified with class "order" (cf. theory
  3002 Orderings), added parameter "less".  INCOMPATIBILITY.
  3003 
  3004 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3005 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3006 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3007 
  3008 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3009 changed order of proof goals in instance proofs.
  3010 
  3011 * The transitivity reasoner for partial and linear orders is set up
  3012 for classes "order" and "linorder".  Instances of the reasoner are available
  3013 in all contexts importing or interpreting the corresponding locales.
  3014 Method "order" invokes the reasoner separately; the reasoner
  3015 is also integrated with the Simplifier as a solver.  Diagnostic
  3016 command 'print_orders' shows the available instances of the reasoner
  3017 in the current context.
  3018 
  3019 * Localized monotonicity predicate in theory "Orderings"; integrated
  3020 lemmas max_of_mono and min_of_mono with this predicate.
  3021 INCOMPATIBILITY.
  3022 
  3023 * Formulation of theorem "dense" changed slightly due to integration
  3024 with new class dense_linear_order.
  3025 
  3026 * Uniform lattice theory development in HOL.
  3027 
  3028     constants "meet" and "join" now named "inf" and "sup"
  3029     constant "Meet" now named "Inf"
  3030 
  3031     classes "meet_semilorder" and "join_semilorder" now named
  3032       "lower_semilattice" and "upper_semilattice"
  3033     class "lorder" now named "lattice"
  3034     class "comp_lat" now named "complete_lattice"
  3035 
  3036     Instantiation of lattice classes allows explicit definitions
  3037     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3038 
  3039   INCOMPATIBILITY.  Theorem renames:
  3040 
  3041     meet_left_le            ~> inf_le1
  3042     meet_right_le           ~> inf_le2
  3043     join_left_le            ~> sup_ge1
  3044     join_right_le           ~> sup_ge2
  3045     meet_join_le            ~> inf_sup_ord
  3046     le_meetI                ~> le_infI
  3047     join_leI                ~> le_supI
  3048     le_meet                 ~> le_inf_iff
  3049     le_join                 ~> ge_sup_conv
  3050     meet_idempotent         ~> inf_idem
  3051     join_idempotent         ~> sup_idem
  3052     meet_comm               ~> inf_commute
  3053     join_comm               ~> sup_commute
  3054     meet_leI1               ~> le_infI1
  3055     meet_leI2               ~> le_infI2
  3056     le_joinI1               ~> le_supI1
  3057     le_joinI2               ~> le_supI2
  3058     meet_assoc              ~> inf_assoc
  3059     join_assoc              ~> sup_assoc
  3060     meet_left_comm          ~> inf_left_commute
  3061     meet_left_idempotent    ~> inf_left_idem
  3062     join_left_comm          ~> sup_left_commute
  3063     join_left_idempotent    ~> sup_left_idem
  3064     meet_aci                ~> inf_aci
  3065     join_aci                ~> sup_aci
  3066     le_def_meet             ~> le_iff_inf
  3067     le_def_join             ~> le_iff_sup
  3068     join_absorp2            ~> sup_absorb2
  3069     join_absorp1            ~> sup_absorb1
  3070     meet_absorp1            ~> inf_absorb1
  3071     meet_absorp2            ~> inf_absorb2
  3072     meet_join_absorp        ~> inf_sup_absorb
  3073     join_meet_absorp        ~> sup_inf_absorb
  3074     distrib_join_le         ~> distrib_sup_le
  3075     distrib_meet_le         ~> distrib_inf_le
  3076 
  3077     add_meet_distrib_left   ~> add_inf_distrib_left
  3078     add_join_distrib_left   ~> add_sup_distrib_left
  3079     is_join_neg_meet        ~> is_join_neg_inf
  3080     is_meet_neg_join        ~> is_meet_neg_sup
  3081     add_meet_distrib_right  ~> add_inf_distrib_right
  3082     add_join_distrib_right  ~> add_sup_distrib_right
  3083     add_meet_join_distribs  ~> add_sup_inf_distribs
  3084     join_eq_neg_meet        ~> sup_eq_neg_inf
  3085     meet_eq_neg_join        ~> inf_eq_neg_sup
  3086     add_eq_meet_join        ~> add_eq_inf_sup
  3087     meet_0_imp_0            ~> inf_0_imp_0
  3088     join_0_imp_0            ~> sup_0_imp_0
  3089     meet_0_eq_0             ~> inf_0_eq_0
  3090     join_0_eq_0             ~> sup_0_eq_0
  3091     neg_meet_eq_join        ~> neg_inf_eq_sup
  3092     neg_join_eq_meet        ~> neg_sup_eq_inf
  3093     join_eq_if              ~> sup_eq_if
  3094 
  3095     mono_meet               ~> mono_inf
  3096     mono_join               ~> mono_sup
  3097     meet_bool_eq            ~> inf_bool_eq
  3098     join_bool_eq            ~> sup_bool_eq
  3099     meet_fun_eq             ~> inf_fun_eq
  3100     join_fun_eq             ~> sup_fun_eq
  3101     meet_set_eq             ~> inf_set_eq
  3102     join_set_eq             ~> sup_set_eq
  3103     meet1_iff               ~> inf1_iff
  3104     meet2_iff               ~> inf2_iff
  3105     meet1I                  ~> inf1I
  3106     meet2I                  ~> inf2I
  3107     meet1D1                 ~> inf1D1
  3108     meet2D1                 ~> inf2D1
  3109     meet1D2                 ~> inf1D2
  3110     meet2D2                 ~> inf2D2
  3111     meet1E                  ~> inf1E
  3112     meet2E                  ~> inf2E
  3113     join1_iff               ~> sup1_iff
  3114     join2_iff               ~> sup2_iff
  3115     join1I1                 ~> sup1I1
  3116     join2I1                 ~> sup2I1
  3117     join1I1                 ~> sup1I1
  3118     join2I2                 ~> sup1I2
  3119     join1CI                 ~> sup1CI
  3120     join2CI                 ~> sup2CI
  3121     join1E                  ~> sup1E
  3122     join2E                  ~> sup2E
  3123 
  3124     is_meet_Meet            ~> is_meet_Inf
  3125     Meet_bool_def           ~> Inf_bool_def
  3126     Meet_fun_def            ~> Inf_fun_def
  3127     Meet_greatest           ~> Inf_greatest
  3128     Meet_lower              ~> Inf_lower
  3129     Meet_set_def            ~> Inf_set_def
  3130 
  3131     Sup_def                 ~> Sup_Inf
  3132     Sup_bool_eq             ~> Sup_bool_def
  3133     Sup_fun_eq              ~> Sup_fun_def
  3134     Sup_set_eq              ~> Sup_set_def
  3135 
  3136     listsp_meetI            ~> listsp_infI
  3137     listsp_meet_eq          ~> listsp_inf_eq
  3138 
  3139     meet_min                ~> inf_min
  3140     join_max                ~> sup_max
  3141 
  3142 * Added syntactic class "size"; overloaded constant "size" now has
  3143 type "'a::size ==> bool"
  3144 
  3145 * Internal reorganisation of `size' of datatypes: size theorems
  3146 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3147 simplification rules by default!); theorems "prod.size" now named
  3148 "*.size".
  3149 
  3150 * Class "div" now inherits from class "times" rather than "type".
  3151 INCOMPATIBILITY.
  3152 
  3153 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3154 Linorder etc.  have disappeared; operations defined in terms of
  3155 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3156 
  3157 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3158 
  3159 * HOL-Word: New extensive library and type for generic, fixed size
  3160 machine words, with arithemtic, bit-wise, shifting and rotating
  3161 operations, reflection into int, nat, and bool lists, automation for
  3162 linear arithmetic (by automatic reflection into nat or int), including
  3163 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3164 arithmetic type classes, supporting automatic simplification of
  3165 numerals on all operations.
  3166 
  3167 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3168 
  3169 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3170 
  3171 * Code generator library theories:
  3172   - Code_Integer represents HOL integers by big integer literals in target
  3173     languages.
  3174   - Code_Char represents HOL characters by character literals in target
  3175     languages.
  3176   - Code_Char_chr like Code_Char, but also offers treatment of character
  3177     codes; includes Code_Integer.
  3178   - Executable_Set allows to generate code for finite sets using lists.
  3179   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3180     denominator).
  3181   - Executable_Real implements a subset of real numbers, namly those
  3182     representable by rational numbers.
  3183   - Efficient_Nat implements natural numbers by integers, which in general will
  3184     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3185     includes Code_Integer.
  3186   - Code_Index provides an additional datatype index which is mapped to
  3187     target-language built-in integers.
  3188   - Code_Message provides an additional datatype message_string which is isomorphic to
  3189     strings; messages are mapped to target-language strings.
  3190 
  3191 * New package for inductive predicates
  3192 
  3193   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3194 
  3195     inductive
  3196       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3197       for z_1 :: U_1 and ... and z_n :: U_m
  3198     where
  3199       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3200     | ...
  3201 
  3202   with full support for type-inference, rather than
  3203 
  3204     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3205 
  3206     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3207     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3208 
  3209     inductive "s z_1 ... z_m"
  3210     intros
  3211       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3212       ...
  3213 
  3214   For backward compatibility, there is a wrapper allowing inductive
  3215   sets to be defined with the new package via
  3216 
  3217     inductive_set
  3218       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3219       for z_1 :: U_1 and ... and z_n :: U_m
  3220     where
  3221       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3222     | ...
  3223 
  3224   or
  3225 
  3226     inductive_set
  3227       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3228       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3229       for z_1 :: U_1 and ... and z_n :: U_m
  3230     where
  3231       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3232     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3233     | ...
  3234 
  3235   if the additional syntax "p ..." is required.
  3236 
  3237   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3238   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3239 
  3240   INCOMPATIBILITIES:
  3241 
  3242   - Since declaration and definition of inductive sets or predicates
  3243     is no longer separated, abbreviations involving the newly
  3244     introduced sets or predicates must be specified together with the
  3245     introduction rules after the 'where' keyword (see above), rather
  3246     than before the actual inductive definition.
  3247 
  3248   - The variables in induction and elimination rules are now
  3249     quantified in the order of their occurrence in the introduction
  3250     rules, rather than in alphabetical order. Since this may break
  3251     some proofs, these proofs either have to be repaired, e.g. by
  3252     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3253     statements of the form
  3254 
  3255       case (rule_i a_i_1 ... a_i_{k_i})
  3256 
  3257     or the old order of quantification has to be restored by explicitly adding
  3258     meta-level quantifiers in the introduction rules, i.e.
  3259 
  3260       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3261 
  3262   - The format of the elimination rules is now
  3263 
  3264       p z_1 ... z_m x_1 ... x_n ==>
  3265         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3266         ==> ... ==> P
  3267 
  3268     for predicates and
  3269 
  3270       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3271         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3272         ==> ... ==> P
  3273 
  3274     for sets rather than
  3275 
  3276       x : s z_1 ... z_m ==>
  3277         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3278         ==> ... ==> P
  3279 
  3280     This may require terms in goals to be expanded to n-tuples
  3281     (e.g. using case_tac or simplification with the split_paired_all
  3282     rule) before the above elimination rule is applicable.
  3283 
  3284   - The elimination or case analysis rules for (mutually) inductive
  3285     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3286     list of rules "p_1_..._p_k.elims" is no longer available.
  3287 
  3288 * New package "function"/"fun" for general recursive functions,
  3289 supporting mutual and nested recursion, definitions in local contexts,
  3290 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3291 for small examples, and the separate tutorial on the function
  3292 package. The old recdef "package" is still available as before, but
  3293 users are encouraged to use the new package.
  3294 
  3295 * Method "lexicographic_order" automatically synthesizes termination
  3296 relations as lexicographic combinations of size measures. 
  3297 
  3298 * Case-expressions allow arbitrary constructor-patterns (including
  3299 "_") and take their order into account, like in functional
  3300 programming.  Internally, this is translated into nested
  3301 case-expressions; missing cases are added and mapped to the predefined
  3302 constant "undefined". In complicated cases printing may no longer show
  3303 the original input but the internal form. Lambda-abstractions allow
  3304 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3305 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3306 variable.
  3307 
  3308 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3309 is an abbreviation for "of_nat :: nat => int". The simplification
  3310 rules for "of_nat" have been changed to work like "int" did
  3311 previously.  Potential INCOMPATIBILITY:
  3312   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3313   - of_nat_diff and of_nat_mult are no longer default simp rules
  3314 
  3315 * Method "algebra" solves polynomial equations over (semi)rings using
  3316 Groebner bases. The (semi)ring structure is defined by locales and the
  3317 tool setup depends on that generic context. Installing the method for
  3318 a specific type involves instantiating the locale and possibly adding
  3319 declarations for computation on the coefficients.  The method is
  3320 already instantiated for natural numbers and for the axiomatic class
  3321 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3322 CALCULEMUS 2007 for the general principles underlying this
  3323 architecture of context-aware proof-tools.
  3324 
  3325 * Method "ferrack" implements quantifier elimination over
  3326 special-purpose dense linear orders using locales (analogous to
  3327 "algebra"). The method is already installed for class
  3328 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3329 rat, etc.
  3330 
  3331 * Former constant "List.op @" now named "List.append".  Use ML
  3332 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3333 circumvent possible incompatibilities when working on ML level.
  3334 
  3335 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3336 
  3337 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3338 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3339 
  3340 * New syntax for Haskell-like list comprehension (input only), eg.
  3341 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3342 
  3343 * The special syntax for function "filter" has changed from [x :
  3344 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3345 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3346 
  3347 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3348 defined on nat only, as an abbreviation for [a..<Suc b]
  3349 INCOMPATIBILITY.
  3350 
  3351 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3352 
  3353 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3354 
  3355 * New lemma collection field_simps (an extension of ring_simps) for
  3356 manipulating (in)equations involving division. Multiplies with all
  3357 denominators that can be proved to be non-zero (in equations) or
  3358 positive/negative (in inequations).
  3359 
  3360 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3361 have been improved and renamed to ring_simps, group_simps and
  3362 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3363 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3364 
  3365 * Theory Library/Commutative_Ring: switched from recdef to function
  3366 package; constants add, mul, pow now curried.  Infix syntax for
  3367 algebraic operations.
  3368 
  3369 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3370 INCOMPATIBILITY.
  3371 
  3372 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3373 INCOMPATIBILITY.
  3374 
  3375 * HOL/records: generalised field-update to take a function on the
  3376 field rather than the new value: r(|A := x|) is translated to A_update
  3377 (K x) r The K-combinator that is internally used is called K_record.
  3378 INCOMPATIBILITY: Usage of the plain update functions has to be
  3379 adapted.
  3380  
  3381 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3382 * x = 0, which are required for a semiring.  Richer structures do not
  3383 inherit from semiring_0 anymore, because this property is a theorem
  3384 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3385 there is more to prove, but this is mostly trivial.
  3386 
  3387 * Class "recpower" is generalized to arbitrary monoids, not just
  3388 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3389 commutativity or semiring properties additionally.
  3390 
  3391 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3392 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3393 better use 'abbreviation'.
  3394 
  3395 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3396 
  3397 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3398 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3399 significant changes for setting up numeral syntax for types:
  3400   - New constants Numeral.pred and Numeral.succ instead
  3401       of former Numeral.bin_pred and Numeral.bin_succ.
  3402   - Use integer operations instead of bin_add, bin_mult and so on.
  3403   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3404   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3405 
  3406 See src/HOL/Integ/IntArith.thy for an example setup.
  3407 
  3408 * Command 'normal_form' computes the normal form of a term that may
  3409 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3410 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3411 heavy-duty computations because the functions are compiled to ML
  3412 first.  Correspondingly, a method "normalization" is provided.  See
  3413 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3414 
  3415 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3416 25 like -->); output depends on the "iff" print_mode, the default is
  3417 "A = B" (with priority 50).
  3418 
  3419 * Relations less (<) and less_eq (<=) are also available on type bool.
  3420 Modified syntax to disallow nesting without explicit parentheses,
  3421 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3422 INCOMPATIBILITY.
  3423 
  3424 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3425 
  3426 * Relation composition operator "op O" now has precedence 75 and binds
  3427 stronger than union and intersection. INCOMPATIBILITY.
  3428 
  3429 * The old set interval syntax "{m..n(}" (and relatives) has been
  3430 removed.  Use "{m..<n}" (and relatives) instead.
  3431 
  3432 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3433 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3434 ``declare [[simproc del: neq]]''.
  3435 
  3436 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3437 True/False.
  3438 
  3439 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3440 
  3441 * Theorem setsum_mult renamed to setsum_right_distrib.
  3442 
  3443 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3444 ``rule'' method.
  3445 
  3446 * Reimplemented methods "sat" and "satx", with several improvements:
  3447 goals no longer need to be stated as "<prems> ==> False", equivalences
  3448 (i.e. "=" on type bool) are handled, variable names of the form
  3449 "lit_<n>" are no longer reserved, significant speedup.
  3450 
  3451 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3452 zChaff is still supported as well.
  3453 
  3454 * 'inductive' and 'datatype': provide projections of mutual rules,
  3455 bundled as foo_bar.inducts;
  3456 
  3457 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3458 Library.
  3459 
  3460 * Library: moved theory Accessible_Part to main HOL.
  3461 
  3462 * Library: added theory Coinductive_List of potentially infinite lists
  3463 as greatest fixed-point.
  3464 
  3465 * Library: added theory AssocList which implements (finite) maps as
  3466 association lists.
  3467 
  3468 * Method "evaluation" solves goals (i.e. a boolean expression)
  3469 efficiently by compiling it to ML.  The goal is "proved" (via an
  3470 oracle) if it evaluates to True.
  3471 
  3472 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3473 also when invoked by the simplifier.  This results in the Simplifier
  3474 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3475 Configuration option fast_arith_split_limit=0 recovers the old
  3476 behavior.
  3477 
  3478 * Support for hex (0x20) and binary (0b1001) numerals.
  3479 
  3480 * New method: reify eqs (t), where eqs are equations for an
  3481 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3482 parameter, computes a term s::'b and a list xs::'a list and proves the
  3483 theorem I xs s = t. This is also known as reification or quoting. The
  3484 resulting theorem is applied to the subgoal to substitute t with I xs
  3485 s.  If t is omitted, the subgoal itself is reified.
  3486 
  3487 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3488 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3489 where f is supposed to be a computable function (in the sense of code
  3490 generattion). The method uses reify to compute s and xs as above then
  3491 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3492 r and finally gets the theorem t = r, which is again applied to the
  3493 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3494 
  3495 * Reflection: Automatic reification now handels binding, an example is
  3496 available in src/HOL/ex/ReflectionEx.thy
  3497 
  3498 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3499 command 'statespace' that is similar to 'record', but introduces an
  3500 abstract specification based on the locale infrastructure instead of
  3501 HOL types.  This leads to extra flexibility in composing state spaces,
  3502 in particular multiple inheritance and renaming of components.
  3503 
  3504 
  3505 *** HOL-Complex ***
  3506 
  3507 * Hyperreal: Functions root and sqrt are now defined on negative real
  3508 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3509 Nonnegativity side conditions have been removed from many lemmas, so
  3510 that more subgoals may now be solved by simplification; potential
  3511 INCOMPATIBILITY.
  3512 
  3513 * Real: new type classes formalize real normed vector spaces and
  3514 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3515 and norm :: 'a => real.
  3516 
  3517 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3518 reals into other types. The overloaded constant Reals :: 'a set is now
  3519 defined as range of_real; potential INCOMPATIBILITY.
  3520 
  3521 * Real: proper support for ML code generation, including 'quickcheck'.
  3522 Reals are implemented as arbitrary precision rationals.
  3523 
  3524 * Hyperreal: Several constants that previously worked only for the
  3525 reals have been generalized, so they now work over arbitrary vector
  3526 spaces. Type annotations may need to be added in some cases; potential
  3527 INCOMPATIBILITY.
  3528 
  3529   Infinitesimal  :: ('a::real_normed_vector) star set
  3530   HFinite        :: ('a::real_normed_vector) star set
  3531   HInfinite      :: ('a::real_normed_vector) star set
  3532   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3533   monad          :: ('a::real_normed_vector) star => 'a star set
  3534   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3535   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3536   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3537   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3538   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3539   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3540   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3541   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3542   sgn            :: 'a::real_normed_vector => 'a
  3543   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3544 
  3545 * Complex: Some complex-specific constants are now abbreviations for
  3546 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3547 hnorm.  Other constants have been entirely removed in favor of the
  3548 polymorphic versions (INCOMPATIBILITY):
  3549 
  3550   approx        <-- capprox
  3551   HFinite       <-- CFinite
  3552   HInfinite     <-- CInfinite
  3553   Infinitesimal <-- CInfinitesimal
  3554   monad         <-- cmonad
  3555   galaxy        <-- cgalaxy
  3556   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3557   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3558   (ns)deriv     <-- (ns)cderiv
  3559 
  3560 
  3561 *** HOL-Algebra ***
  3562 
  3563 * Formalisation of ideals and the quotient construction over rings.
  3564 
  3565 * Order and lattice theory no longer based on records.
  3566 INCOMPATIBILITY.
  3567 
  3568 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3569 greatest_closed.  INCOMPATIBILITY.
  3570 
  3571 * Method algebra is now set up via an attribute.  For examples see
  3572 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3573 of algebraic structures.
  3574 
  3575 * Renamed theory CRing to Ring.
  3576 
  3577 
  3578 *** HOL-Nominal ***
  3579 
  3580 * Substantial, yet incomplete support for nominal datatypes (binding
  3581 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3582 src/HOL/Nominal/Examples.  Prospective users should consult
  3583 http://isabelle.in.tum.de/nominal/
  3584 
  3585 
  3586 *** ML ***
  3587 
  3588 * ML basics: just one true type int, which coincides with IntInf.int
  3589 (even on SML/NJ).
  3590 
  3591 * ML within Isar: antiquotations allow to embed statically-checked
  3592 formal entities in the source, referring to the context available at
  3593 compile-time.  For example:
  3594 
  3595 ML {* @{sort "{zero,one}"} *}
  3596 ML {* @{typ "'a => 'b"} *}
  3597 ML {* @{term "%x. x"} *}
  3598 ML {* @{prop "x == y"} *}
  3599 ML {* @{ctyp "'a => 'b"} *}
  3600 ML {* @{cterm "%x. x"} *}
  3601 ML {* @{cprop "x == y"} *}
  3602 ML {* @{thm asm_rl} *}
  3603 ML {* @{thms asm_rl} *}
  3604 ML {* @{type_name c} *}
  3605 ML {* @{type_syntax c} *}
  3606 ML {* @{const_name c} *}
  3607 ML {* @{const_syntax c} *}
  3608 ML {* @{context} *}
  3609 ML {* @{theory} *}
  3610 ML {* @{theory Pure} *}
  3611 ML {* @{theory_ref} *}
  3612 ML {* @{theory_ref Pure} *}
  3613 ML {* @{simpset} *}
  3614 ML {* @{claset} *}
  3615 ML {* @{clasimpset} *}
  3616 
  3617 The same works for sources being ``used'' within an Isar context.
  3618 
  3619 * ML in Isar: improved error reporting; extra verbosity with
  3620 ML_Context.trace enabled.
  3621 
  3622 * Pure/General/table.ML: the join operations now works via exceptions
  3623 DUP/SAME instead of type option. This is simpler in simple cases, and
  3624 admits slightly more efficient complex applications.
  3625 
  3626 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3627 use Context.generic instead of just theory.
  3628 
  3629 * Pure: datatype Context.generic joins theory/Proof.context and
  3630 provides some facilities for code that works in either kind of
  3631 context, notably GenericDataFun for uniform theory and proof data.
  3632 
  3633 * Pure: simplified internal attribute type, which is now always
  3634 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3635 local (Proof.context) attributes have been discontinued, while
  3636 minimizing code duplication. Thm.rule_attribute and
  3637 Thm.declaration_attribute build canonical attributes; see also structure
  3638 Context for further operations on Context.generic, notably
  3639 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3640 declarations and definitions.
  3641 
  3642 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3643 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3644 init only required for impure data. INCOMPATIBILITY: empty really need
  3645 to be empty (no dependencies on theory content!)
  3646 
  3647 * Pure/kernel: consts certification ignores sort constraints given in
  3648 signature declarations. (This information is not relevant to the
  3649 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3650 potential INCOMPATIBILITY.
  3651 
  3652 * Pure: axiomatic type classes are now purely definitional, with
  3653 explicit proofs of class axioms and super class relations performed
  3654 internally. See Pure/axclass.ML for the main internal interfaces --
  3655 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3656 AxClass.axiomatize_class/classrel/arity supersede
  3657 Sign.add_classes/classrel/arities.
  3658 
  3659 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3660 global/local versions on theory vs. Proof.context have been
  3661 discontinued; Attrib.syntax and Method.syntax have been adapted
  3662 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3663 attributes, methods, etc.
  3664 
  3665 * Pure: several functions of signature "... -> theory -> theory * ..."
  3666 have been reoriented to "... -> theory -> ... * theory" in order to
  3667 allow natural usage in combination with the ||>, ||>>, |-> and
  3668 fold_map combinators.
  3669 
  3670 * Pure: official theorem names (closed derivations) and additional
  3671 comments (tags) are now strictly separate.  Name hints -- which are
  3672 maintained as tags -- may be attached any time without affecting the
  3673 derivation.
  3674 
  3675 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3676 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3677 achieve the old behaviour.
  3678 
  3679 * Pure: the "Goal" constant is now called "prop", supporting a
  3680 slightly more general idea of ``protecting'' meta-level rule
  3681 statements.
  3682 
  3683 * Pure: Logic.(un)varify only works in a global context, which is now
  3684 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3685 Logic.legacy_(un)varify as temporary workaround.
  3686 
  3687 * Pure: structure Name provides scalable operations for generating
  3688 internal variable names, notably Name.variants etc.  This replaces
  3689 some popular functions from term.ML:
  3690 
  3691   Term.variant		->  Name.variant
  3692   Term.variantlist	->  Name.variant_list
  3693   Term.invent_names	->  Name.invent_list
  3694 
  3695 Note that low-level renaming rarely occurs in new code -- operations
  3696 from structure Variable are used instead (see below).
  3697 
  3698 * Pure: structure Variable provides fundamental operations for proper
  3699 treatment of fixed/schematic variables in a context.  For example,
  3700 Variable.import introduces fixes for schematics of given facts and
  3701 Variable.export reverses the effect (up to renaming) -- this replaces
  3702 various freeze_thaw operations.
  3703 
  3704 * Pure: structure Goal provides simple interfaces for
  3705 init/conclude/finish and tactical prove operations (replacing former
  3706 Tactic.prove).  Goal.prove is the canonical way to prove results
  3707 within a given context; Goal.prove_global is a degraded version for
  3708 theory level goals, including a global Drule.standard.  Note that
  3709 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3710 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3711 in a locale context).
  3712 
  3713 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3714 and type checking (Syntax.check_term etc.), with common combinations
  3715 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3716 which are considered legacy and await removal.
  3717 
  3718 * Pure/Syntax: generic interfaces for type unchecking
  3719 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3720 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3721 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3722 available for convenience, but refer to the very same operations using
  3723 a mere theory instead of a full context.
  3724 
  3725 * Isar: simplified treatment of user-level errors, using exception
  3726 ERROR of string uniformly.  Function error now merely raises ERROR,
  3727 without any side effect on output channels.  The Isar toplevel takes
  3728 care of proper display of ERROR exceptions.  ML code may use plain
  3729 handle/can/try; cat_error may be used to concatenate errors like this:
  3730 
  3731   ... handle ERROR msg => cat_error msg "..."
  3732 
  3733 Toplevel ML code (run directly or through the Isar toplevel) may be
  3734 embedded into the Isar toplevel with exception display/debug like
  3735 this:
  3736 
  3737   Isar.toplevel (fn () => ...)
  3738 
  3739 INCOMPATIBILITY, removed special transform_error facilities, removed
  3740 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3741 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3742 -- use plain ERROR instead.
  3743 
  3744 * Isar: theory setup now has type (theory -> theory), instead of a
  3745 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3746 
  3747 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3748 ProofContext.debug/verbose flags.
  3749 
  3750 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3751 theory before entering a proof state.  Transactions now always see a
  3752 quasi-functional intermediate checkpoint, both in interactive and
  3753 batch mode.
  3754 
  3755 * Isar: simplified interfaces for outer syntax.  Renamed
  3756 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3757 OuterSyntax.add_parsers -- this functionality is now included in
  3758 OuterSyntax.command etc.  INCOMPATIBILITY.
  3759 
  3760 * Simplifier: the simpset of a running simplification process now
  3761 contains a proof context (cf. Simplifier.the_context), which is the
  3762 very context that the initial simpset has been retrieved from (by
  3763 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3764 (solver, looper etc.) may depend on arbitrary proof data.
  3765 
  3766 * Simplifier.inherit_context inherits the proof context (plus the
  3767 local bounds) of the current simplification process; any simproc
  3768 etc. that calls the Simplifier recursively should do this!  Removed
  3769 former Simplifier.inherit_bounds, which is already included here --
  3770 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3771 specify an explicit context using Simplifier.context/theory_context.
  3772 
  3773 * Simplifier/Classical Reasoner: more abstract interfaces
  3774 change_simpset/claset for modifying the simpset/claset reference of a
  3775 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3776 INCOMPATIBILITY.
  3777 
  3778 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3779 "Trueprop" etc.
  3780 
  3781 
  3782 *** System ***
  3783 
  3784 * settings: the default heap location within ISABELLE_HOME_USER now
  3785 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3786 Isabelle installations.
  3787 
  3788 * isabelle-process: option -S (secure mode) disables some critical
  3789 operations, notably runtime compilation and evaluation of ML source
  3790 code.
  3791 
  3792 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3793 
  3794 * Support for parallel execution, using native multicore support of
  3795 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3796 independent theories, according to the given theory header
  3797 specifications. The maximum number of worker threads is specified via
  3798 usedir option -M or the "max-threads" setting in Proof General. A
  3799 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3800 to 6 on a 8-core machine.  User-code needs to observe certain
  3801 guidelines for thread-safe programming, see appendix A in the Isar
  3802 Implementation manual.
  3803 
  3804 
  3805 
  3806 New in Isabelle2005 (October 2005)
  3807 ----------------------------------
  3808 
  3809 *** General ***
  3810 
  3811 * Theory headers: the new header syntax for Isar theories is
  3812 
  3813   theory <name>
  3814   imports <theory1> ... <theoryN>
  3815   uses <file1> ... <fileM>
  3816   begin
  3817 
  3818 where the 'uses' part is optional.  The previous syntax
  3819 
  3820   theory <name> = <theory1> + ... + <theoryN>:
  3821 
  3822 will disappear in the next release.  Use isatool fixheaders to convert
  3823 existing theory files.  Note that there is no change in ancient
  3824 non-Isar theories now, but these will disappear soon.
  3825 
  3826 * Theory loader: parent theories can now also be referred to via
  3827 relative and absolute paths.
  3828 
  3829 * Command 'find_theorems' searches for a list of criteria instead of a
  3830 list of constants. Known criteria are: intro, elim, dest, name:string,
  3831 simp:term, and any term. Criteria can be preceded by '-' to select
  3832 theorems that do not match. Intro, elim, dest select theorems that
  3833 match the current goal, name:s selects theorems whose fully qualified
  3834 name contain s, and simp:term selects all simplification rules whose
  3835 lhs match term.  Any other term is interpreted as pattern and selects
  3836 all theorems matching the pattern. Available in ProofGeneral under
  3837 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3838 
  3839   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3840 
  3841 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3842 matching the current goal as introduction rule and not having "HOL."
  3843 in their name (i.e. not being defined in theory HOL).
  3844 
  3845 * Command 'thms_containing' has been discontinued in favour of
  3846 'find_theorems'; INCOMPATIBILITY.
  3847 
  3848 * Communication with Proof General is now 8bit clean, which means that
  3849 Unicode text in UTF-8 encoding may be used within theory texts (both
  3850 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3851 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3852 
  3853   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3854   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3855 
  3856 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3857 Classical Reasoner.  Typical big applications run around 2 times
  3858 faster.
  3859 
  3860 
  3861 *** Document preparation ***
  3862 
  3863 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3864 of raw sources.  Only those symbols that do not require additional
  3865 LaTeX packages (depending on comments in isabellesym.sty) are
  3866 displayed properly, everything else is left verbatim.  isatool display
  3867 and isatool print are used as front ends (these are subject to the
  3868 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3869 
  3870 * Command tags control specific markup of certain regions of text,
  3871 notably folding and hiding.  Predefined tags include "theory" (for
  3872 theory begin and end), "proof" for proof commands, and "ML" for
  3873 commands involving ML code; the additional tags "visible" and
  3874 "invisible" are unused by default.  Users may give explicit tag
  3875 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3876 interpretation of tags is determined by the LaTeX job during document
  3877 preparation: see option -V of isatool usedir, or options -n and -t of
  3878 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3879 \isadroptag.
  3880 
  3881 Several document versions may be produced at the same time via isatool
  3882 usedir (the generated index.html will link all of them).  Typical
  3883 specifications include ''-V document=theory,proof,ML'' to present
  3884 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3885 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3886 these parts without any formal replacement text.  The Isabelle site
  3887 default settings produce ''document'' and ''outline'' versions as
  3888 specified above.
  3889 
  3890 * Several new antiquotations:
  3891 
  3892   @{term_type term} prints a term with its type annotated;
  3893 
  3894   @{typeof term} prints the type of a term;
  3895 
  3896   @{const const} is the same as @{term const}, but checks that the
  3897   argument is a known logical constant;
  3898 
  3899   @{term_style style term} and @{thm_style style thm} print a term or
  3900   theorem applying a "style" to it
  3901 
  3902   @{ML text}
  3903 
  3904 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3905 definitions, equations, inequations etc., 'concl' printing only the
  3906 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3907 to print the specified premise.  TermStyle.add_style provides an ML
  3908 interface for introducing further styles.  See also the "LaTeX Sugar"
  3909 document practical applications.  The ML antiquotation prints
  3910 type-checked ML expressions verbatim.
  3911 
  3912 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3913 and 'text' support optional locale specification '(in loc)', which
  3914 specifies the default context for interpreting antiquotations.  For
  3915 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3916 
  3917 * Option 'locale=NAME' of antiquotations specifies an alternative
  3918 context interpreting the subsequent argument.  For example: @{thm
  3919 [locale=lattice] inf_assoc}.
  3920 
  3921 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3922 a proof context.
  3923 
  3924 * Proper output of antiquotations for theory commands involving a
  3925 proof context (such as 'locale' or 'theorem (in loc) ...').
  3926 
  3927 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3928 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3929 
  3930 * isatool usedir: new option -C (default true) controls whether option
  3931 -D should include a copy of the original document directory; -C false
  3932 prevents unwanted effects such as copying of administrative CVS data.
  3933 
  3934 
  3935 *** Pure ***
  3936 
  3937 * Considerably improved version of 'constdefs' command.  Now performs
  3938 automatic type-inference of declared constants; additional support for
  3939 local structure declarations (cf. locales and HOL records), see also
  3940 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3941 sequential dependencies of definitions within a single 'constdefs'
  3942 section; moreover, the declared name needs to be an identifier.  If
  3943 all fails, consider to fall back on 'consts' and 'defs' separately.
  3944 
  3945 * Improved indexed syntax and implicit structures.  First of all,
  3946 indexed syntax provides a notational device for subscripted
  3947 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3948 expressions.  Secondly, in a local context with structure
  3949 declarations, number indexes \<^sub>n or the empty index (default
  3950 number 1) refer to a certain fixed variable implicitly; option
  3951 show_structs controls printing of implicit structures.  Typical
  3952 applications of these concepts involve record types and locales.
  3953 
  3954 * New command 'no_syntax' removes grammar declarations (and
  3955 translations) resulting from the given syntax specification, which is
  3956 interpreted in the same manner as for the 'syntax' command.
  3957 
  3958 * 'Advanced' translation functions (parse_translation etc.) may depend
  3959 on the signature of the theory context being presently used for
  3960 parsing/printing, see also isar-ref manual.
  3961 
  3962 * Improved 'oracle' command provides a type-safe interface to turn an
  3963 ML expression of type theory -> T -> term into a primitive rule of
  3964 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3965 is already included here); see also FOL/ex/IffExample.thy;
  3966 INCOMPATIBILITY.
  3967 
  3968 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3969 before); "cI" is no longer bound, use "c.intro" instead.
  3970 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3971 axclasses vs. locales.
  3972 
  3973 * Improved internal renaming of symbolic identifiers -- attach primes
  3974 instead of base 26 numbers.
  3975 
  3976 * New flag show_question_marks controls printing of leading question
  3977 marks in schematic variable names.
  3978 
  3979 * In schematic variable names, *any* symbol following \<^isub> or
  3980 \<^isup> is now treated as part of the base name.  For example, the
  3981 following works without printing of awkward ".0" indexes:
  3982 
  3983   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3984     by simp
  3985 
  3986 * Inner syntax includes (*(*nested*) comments*).
  3987 
  3988 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3989 annotations as "(00...)".
  3990 
  3991 * Clear separation of logical types and nonterminals, where the latter
  3992 may only occur in 'syntax' specifications or type abbreviations.
  3993 Before that distinction was only partially implemented via type class
  3994 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3995 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3996 exotic syntax specifications may require further adaption
  3997 (e.g. Cube/Cube.thy).
  3998 
  3999 * Removed obsolete type class "logic", use the top sort {} instead.
  4000 Note that non-logical types should be declared as 'nonterminals'
  4001 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4002 specifications.
  4003 
  4004 * Attributes 'induct' and 'cases': type or set names may now be
  4005 locally fixed variables as well.
  4006 
  4007 * Simplifier: can now control the depth to which conditional rewriting
  4008 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4009 Limit.
  4010 
  4011 * Simplifier: simplification procedures may now take the current
  4012 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4013 interface), which is very useful for calling the Simplifier
  4014 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4015 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4016 low-level mk_simproc no longer applies Logic.varify internally, to
  4017 allow for use in a context of fixed variables.
  4018 
  4019 * thin_tac now works even if the assumption being deleted contains !!
  4020 or ==>.  More generally, erule now works even if the major premise of
  4021 the elimination rule contains !! or ==>.
  4022 
  4023 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4024 
  4025 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4026 from Pure, which contains all common declarations already.  Both
  4027 theories are defined via plain Isabelle/Isar .thy files.
  4028 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4029 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4030 use isatool fixcpure to adapt your theory and ML sources.
  4031 
  4032 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4033 selections of theorems in named facts via index ranges.
  4034 
  4035 * 'print_theorems': in theory mode, really print the difference
  4036 wrt. the last state (works for interactive theory development only),
  4037 in proof mode print all local facts (cf. 'print_facts');
  4038 
  4039 * 'hide': option '(open)' hides only base names.
  4040 
  4041 * More efficient treatment of intermediate checkpoints in interactive
  4042 theory development.
  4043 
  4044 * Code generator is now invoked via code_module (incremental code
  4045 generation) and code_library (modular code generation, ML structures
  4046 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4047 must be quoted when used as identifiers.
  4048 
  4049 * New 'value' command for reading, evaluating and printing terms using
  4050 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4051 quoted when used as identifier.
  4052 
  4053 
  4054 *** Locales ***
  4055 
  4056 * New commands for the interpretation of locale expressions in
  4057 theories (1), locales (2) and proof contexts (3).  These generate
  4058 proof obligations from the expression specification.  After the
  4059 obligations have been discharged, theorems of the expression are added
  4060 to the theory, target locale or proof context.  The synopsis of the
  4061 commands is a follows:
  4062 
  4063   (1) interpretation expr inst
  4064   (2) interpretation target < expr
  4065   (3) interpret expr inst
  4066 
  4067 Interpretation in theories and proof contexts require a parameter
  4068 instantiation of terms from the current context.  This is applied to
  4069 specifications and theorems of the interpreted expression.
  4070 Interpretation in locales only permits parameter renaming through the
  4071 locale expression.  Interpretation is smart in that interpretations
  4072 that are active already do not occur in proof obligations, neither are
  4073 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4074 inspect active interpretations of a particular locale.  For details,
  4075 see the Isar Reference manual.  Examples can be found in
  4076 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4077 
  4078 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4079 'interpret' instead.
  4080 
  4081 * New context element 'constrains' for adding type constraints to
  4082 parameters.
  4083 
  4084 * Context expressions: renaming of parameters with syntax
  4085 redeclaration.
  4086 
  4087 * Locale declaration: 'includes' disallowed.
  4088 
  4089 * Proper static binding of attribute syntax -- i.e. types / terms /
  4090 facts mentioned as arguments are always those of the locale definition
  4091 context, independently of the context of later invocations.  Moreover,
  4092 locale operations (renaming and type / term instantiation) are applied
  4093 to attribute arguments as expected.
  4094 
  4095 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4096 actual attributes; rare situations may require Attrib.attribute to
  4097 embed those attributes into Attrib.src that lack concrete syntax.
  4098 Attribute implementations need to cooperate properly with the static
  4099 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4100 Attrib.XXX_thm etc. already do the right thing without further
  4101 intervention.  Only unusual applications -- such as "where" or "of"
  4102 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4103 on the context and the facts involved -- may have to assign parsed
  4104 values to argument tokens explicitly.
  4105 
  4106 * Changed parameter management in theorem generation for long goal
  4107 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4108 theorem statement in rare situations.
  4109 
  4110 * Locale inspection command 'print_locale' omits notes elements.  Use
  4111 'print_locale!' to have them included in the output.
  4112 
  4113 
  4114 *** Provers ***
  4115 
  4116 * Provers/hypsubst.ML: improved version of the subst method, for
  4117 single-step rewriting: it now works in bound variable contexts. New is
  4118 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4119 rewrite a different subterm than the original subst method, which is
  4120 still available as 'simplesubst'.
  4121 
  4122 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4123 and quasi orders.
  4124 
  4125 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4126 reflexive-transitive closure of relations.
  4127 
  4128 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4129 limit (previously hard-coded with a value of 20) user-definable.
  4130 
  4131 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4132 is peformed already.  Object-logics merely need to finish their
  4133 initial simpset configuration as before.  INCOMPATIBILITY.
  4134 
  4135 
  4136 *** HOL ***
  4137 
  4138 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4139 
  4140   syntax (epsilon)
  4141     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4142 
  4143 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4144 and x-symbol; use option '-m epsilon' to get it actually printed.
  4145 Moreover, the mathematically important symbolic identifier \<epsilon>
  4146 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4147 
  4148 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4149 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4150 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4151 support corresponding Isar calculations.
  4152 
  4153 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4154 instead of ":".
  4155 
  4156 * theory SetInterval: changed the syntax for open intervals:
  4157 
  4158   Old       New
  4159   {..n(}    {..<n}
  4160   {)n..}    {n<..}
  4161   {m..n(}   {m..<n}
  4162   {)m..n}   {m<..n}
  4163   {)m..n(}  {m<..<n}
  4164 
  4165 The old syntax is still supported but will disappear in the next
  4166 release.  For conversion use the following Emacs search and replace
  4167 patterns (these are not perfect but work quite well):
  4168 
  4169   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4170   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4171 
  4172 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4173 equalities in commutative rings; method 'algebra' provides a generic
  4174 interface.
  4175 
  4176 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4177 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4178 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4179 be a tuple pattern.
  4180 
  4181 Some new syntax forms are available:
  4182 
  4183   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4184   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4185   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4186   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4187 
  4188 The latter form "\<Sum>x < k. e" used to be based on a separate
  4189 function "Summation", which has been discontinued.
  4190 
  4191 * theory Finite_Set: in structured induction proofs, the insert case
  4192 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4193 (insert F x)'.
  4194 
  4195 * The 'refute' command has been extended to support a much larger
  4196 fragment of HOL, including axiomatic type classes, constdefs and
  4197 typedefs, inductive datatypes and recursion.
  4198 
  4199 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4200 Requires zChaff with proof generation to be installed.  See
  4201 HOL/ex/SAT_Examples.thy for examples.
  4202 
  4203 * Datatype induction via method 'induct' now preserves the name of the
  4204 induction variable. For example, when proving P(xs::'a list) by
  4205 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4206 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4207 in unstructured proof scripts.
  4208 
  4209 * Reworked implementation of records.  Improved scalability for
  4210 records with many fields, avoiding performance problems for type
  4211 inference. Records are no longer composed of nested field types, but
  4212 of nested extension types. Therefore the record type only grows linear
  4213 in the number of extensions and not in the number of fields.  The
  4214 top-level (users) view on records is preserved.  Potential
  4215 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4216 old record representation. The type generated for a record is called
  4217 <record_name>_ext_type.
  4218 
  4219 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4220 proofs triggered by a record definition or a simproc (if
  4221 quick_and_dirty is enabled).  Definitions of large records can take
  4222 quite long.
  4223 
  4224 New simproc record_upd_simproc for simplification of multiple record
  4225 updates enabled by default.  Moreover, trivial updates are also
  4226 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4227 occasionally, since simplification is more powerful by default.
  4228 
  4229 * typedef: proper support for polymorphic sets, which contain extra
  4230 type-variables in the term.
  4231 
  4232 * Simplifier: automatically reasons about transitivity chains
  4233 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4234 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4235 old proofs break occasionally as simplification may now solve more
  4236 goals than previously.
  4237 
  4238 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4239 present.  Works for all partial orders (class "order"), in particular
  4240 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4241 just like y <= x.
  4242 
  4243 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4244 bound variable or a constant then the let is unfolded.  Otherwise
  4245 first a is simplified to b, and then f b is simplified to g. If
  4246 possible we abstract b from g arriving at "let x = b in h x",
  4247 otherwise we unfold the let and arrive at g.  The simproc can be
  4248 enabled/disabled by the reference use_let_simproc.  Potential
  4249 INCOMPATIBILITY since simplification is more powerful by default.
  4250 
  4251 * Classical reasoning: the meson method now accepts theorems as arguments.
  4252 
  4253 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4254 jobs to provide advice on the provability of subgoals.
  4255 
  4256 * Theory OrderedGroup and Ring_and_Field: various additions and
  4257 improvements to faciliate calculations involving equalities and
  4258 inequalities.
  4259 
  4260 The following theorems have been eliminated or modified
  4261 (INCOMPATIBILITY):
  4262 
  4263   abs_eq             now named abs_of_nonneg
  4264   abs_of_ge_0        now named abs_of_nonneg
  4265   abs_minus_eq       now named abs_of_nonpos
  4266   imp_abs_id         now named abs_of_nonneg
  4267   imp_abs_neg_id     now named abs_of_nonpos
  4268   mult_pos           now named mult_pos_pos
  4269   mult_pos_le        now named mult_nonneg_nonneg
  4270   mult_pos_neg_le    now named mult_nonneg_nonpos
  4271   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4272   mult_neg           now named mult_neg_neg
  4273   mult_neg_le        now named mult_nonpos_nonpos
  4274 
  4275 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4276      
  4277      zero_le_square
  4278      not_square_less_zero 
  4279 
  4280   The following lemmas have been deleted from Real/RealPow:
  4281   
  4282      realpow_zero_zero
  4283      realpow_two
  4284      realpow_less
  4285      zero_le_power
  4286      realpow_two_le
  4287      abs_realpow_two
  4288      realpow_two_abs     
  4289 
  4290 * Theory Parity: added rules for simplifying exponents.
  4291 
  4292 * Theory List:
  4293 
  4294 The following theorems have been eliminated or modified
  4295 (INCOMPATIBILITY):
  4296 
  4297   list_all_Nil       now named list_all.simps(1)
  4298   list_all_Cons      now named list_all.simps(2)
  4299   list_all_conv      now named list_all_iff
  4300   set_mem_eq         now named mem_iff
  4301 
  4302 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4303 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4304 
  4305 
  4306 *** HOL-Complex ***
  4307 
  4308 * Theory RealDef: better support for embedding natural numbers and
  4309 integers in the reals.
  4310 
  4311 The following theorems have been eliminated or modified
  4312 (INCOMPATIBILITY):
  4313 
  4314   exp_ge_add_one_self  now requires no hypotheses
  4315   real_of_int_add      reversed direction of equality (use [symmetric])
  4316   real_of_int_minus    reversed direction of equality (use [symmetric])
  4317   real_of_int_diff     reversed direction of equality (use [symmetric])
  4318   real_of_int_mult     reversed direction of equality (use [symmetric])
  4319 
  4320 * Theory RComplete: expanded support for floor and ceiling functions.
  4321 
  4322 * Theory Ln is new, with properties of the natural logarithm
  4323 
  4324 * Hyperreal: There is a new type constructor "star" for making
  4325 nonstandard types.  The old type names are now type synonyms:
  4326 
  4327   hypreal = real star
  4328   hypnat = nat star
  4329   hcomplex = complex star
  4330 
  4331 * Hyperreal: Many groups of similarly-defined constants have been
  4332 replaced by polymorphic versions (INCOMPATIBILITY):
  4333 
  4334   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4335 
  4336   starset      <-- starsetNat, starsetC
  4337   *s*          <-- *sNat*, *sc*
  4338   starset_n    <-- starsetNat_n, starsetC_n
  4339   *sn*         <-- *sNatn*, *scn*
  4340   InternalSets <-- InternalNatSets, InternalCSets
  4341 
  4342   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4343   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4344   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4345   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4346   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4347 
  4348 * Hyperreal: Many type-specific theorems have been removed in favor of
  4349 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4350 
  4351   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4352   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4353   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4354   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4355   right_minus <-- hypreal_add_minus
  4356   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4357   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4358   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4359   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4360   mult_1_right <-- hcomplex_mult_one_right
  4361   mult_zero_left <-- hcomplex_mult_zero_left
  4362   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4363   right_distrib <-- hypnat_add_mult_distrib2
  4364   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4365   right_inverse <-- hypreal_mult_inverse
  4366   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4367   order_refl <-- {hypreal,hypnat}_le_refl
  4368   order_trans <-- {hypreal,hypnat}_le_trans
  4369   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4370   order_less_le <-- {hypreal,hypnat}_less_le
  4371   linorder_linear <-- {hypreal,hypnat}_le_linear
  4372   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4373   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4374   add_nonneg_nonneg <-- hypreal_le_add_order
  4375 
  4376 * Hyperreal: Separate theorems having to do with type-specific
  4377 versions of constants have been merged into theorems that apply to the
  4378 new polymorphic constants (INCOMPATIBILITY):
  4379 
  4380   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4381   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4382   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4383   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4384   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4385   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4386   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4387   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4388   STAR_diff <-- {STAR,STARC}_diff
  4389   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4390     STARC_hcomplex_of_complex}_image_subset
  4391   starset_n_Un <-- starset{Nat,C}_n_Un
  4392   starset_n_Int <-- starset{Nat,C}_n_Int
  4393   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4394   starset_n_diff <-- starset{Nat,C}_n_diff
  4395   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4396   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4397   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4398   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4399   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4400   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4401   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4402   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4403   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4404   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4405   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4406   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4407   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4408   starfun_diff <-- starfun{C,RC,CR}_diff
  4409   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4410   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4411   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4412   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4413   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4414   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4415   starfun_Id <-- starfunC_Id
  4416   starfun_approx <-- starfun{Nat,CR}_approx
  4417   starfun_capprox <-- starfun{C,RC}_capprox
  4418   starfun_abs <-- starfunNat_rabs
  4419   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4420   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4421   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4422   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4423   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4424   starfun_add_approx <-- starfunCR_add_approx
  4425   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4426   starfun_divide <-- starfun{C,CR,RC}_divide
  4427   starfun_n <-- starfun{Nat,C}_n
  4428   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4429   starfun_n_add <-- starfun{Nat,C}_n_add
  4430   starfun_n_add_minus <-- starfunNat_n_add_minus
  4431   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4432   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4433   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4434 
  4435   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4436   star_n_minus <-- {hypreal,hcomplex}_minus
  4437   star_n_diff <-- {hypreal,hcomplex}_diff
  4438   star_n_mult <-- {hypreal,hcomplex}_mult
  4439   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4440   star_n_le <-- {hypreal,hypnat}_le
  4441   star_n_less <-- {hypreal,hypnat}_less
  4442   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4443   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4444   star_n_abs <-- hypreal_hrabs
  4445   star_n_divide <-- hcomplex_divide
  4446 
  4447   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4448   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4449   star_of_diff <-- hypreal_of_real_diff
  4450   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4451   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4452   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4453   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4454   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4455   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4456   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4457   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4458   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4459   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4460   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4461   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4462   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4463   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4464   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4465   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4466   star_of_power <-- hypreal_of_real_power
  4467   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4468 
  4469 * Hyperreal: new method "transfer" that implements the transfer
  4470 principle of nonstandard analysis. With a subgoal that mentions
  4471 nonstandard types like "'a star", the command "apply transfer"
  4472 replaces it with an equivalent one that mentions only standard types.
  4473 To be successful, all free variables must have standard types; non-
  4474 standard variables must have explicit universal quantifiers.
  4475 
  4476 * Hyperreal: A theory of Taylor series.
  4477 
  4478 
  4479 *** HOLCF ***
  4480 
  4481 * Discontinued special version of 'constdefs' (which used to support
  4482 continuous functions) in favor of the general Pure one with full
  4483 type-inference.
  4484 
  4485 * New simplification procedure for solving continuity conditions; it
  4486 is much faster on terms with many nested lambda abstractions (cubic
  4487 instead of exponential time).
  4488 
  4489 * New syntax for domain package: selector names are now optional.
  4490 Parentheses should be omitted unless argument is lazy, for example:
  4491 
  4492   domain 'a stream = cons "'a" (lazy "'a stream")
  4493 
  4494 * New command 'fixrec' for defining recursive functions with pattern
  4495 matching; defining multiple functions with mutual recursion is also
  4496 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4497 sinr, or any data constructor defined by the domain package. The given
  4498 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4499 syntax and examples.
  4500 
  4501 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4502 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4503 but the proof obligation additionally includes an admissibility
  4504 requirement. The packages generate instances of class cpo or pcpo,
  4505 with continuity and strictness theorems for Rep and Abs.
  4506 
  4507 * HOLCF: Many theorems have been renamed according to a more standard naming
  4508 scheme (INCOMPATIBILITY):
  4509 
  4510   foo_inject:  "foo$x = foo$y ==> x = y"
  4511   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4512   foo_less:    "(foo$x << foo$y) = (x << y)"
  4513   foo_strict:  "foo$UU = UU"
  4514   foo_defined: "... ==> foo$x ~= UU"
  4515   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4516 
  4517 
  4518 *** ZF ***
  4519 
  4520 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4521 including the First Isomorphism Theorem (on quotienting by the kernel
  4522 of a homomorphism).
  4523 
  4524 * ZF/Simplifier: install second copy of type solver that actually
  4525 makes use of TC rules declared to Isar proof contexts (or locales);
  4526 the old version is still required for ML proof scripts.
  4527 
  4528 
  4529 *** Cube ***
  4530 
  4531 * Converted to Isar theory format; use locales instead of axiomatic
  4532 theories.
  4533 
  4534 
  4535 *** ML ***
  4536 
  4537 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4538 for ||>, ||>>, |>>,
  4539 
  4540 * Pure/library.ML no longer defines its own option datatype, but uses
  4541 that of the SML basis, which has constructors NONE and SOME instead of
  4542 None and Some, as well as exception Option.Option instead of OPTION.
  4543 The functions the, if_none, is_some, is_none have been adapted
  4544 accordingly, while Option.map replaces apsome.
  4545 
  4546 * Pure/library.ML: the exception LIST has been given up in favour of
  4547 the standard exceptions Empty and Subscript, as well as
  4548 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4549 superceded by the standard hd and tl functions etc.
  4550 
  4551 A number of basic list functions are no longer exported to the ML
  4552 toplevel, as they are variants of predefined functions.  The following
  4553 suggests how one can translate existing code:
  4554 
  4555     rev_append xs ys = List.revAppend (xs, ys)
  4556     nth_elem (i, xs) = List.nth (xs, i)
  4557     last_elem xs = List.last xs
  4558     flat xss = List.concat xss
  4559     seq fs = List.app fs
  4560     partition P xs = List.partition P xs
  4561     mapfilter f xs = List.mapPartial f xs
  4562 
  4563 * Pure/library.ML: several combinators for linear functional
  4564 transformations, notably reverse application and composition:
  4565 
  4566   x |> f                f #> g
  4567   (x, y) |-> f          f #-> g
  4568 
  4569 * Pure/library.ML: introduced/changed precedence of infix operators:
  4570 
  4571   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4572   infix 2 ?;
  4573   infix 3 o oo ooo oooo;
  4574   infix 4 ~~ upto downto;
  4575 
  4576 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4577 infix operators.
  4578 
  4579 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4580 fold_map support linear functional transformations and nesting.  For
  4581 example:
  4582 
  4583   fold f [x1, ..., xN] y =
  4584     y |> f x1 |> ... |> f xN
  4585 
  4586   (fold o fold) f [xs1, ..., xsN] y =
  4587     y |> fold f xs1 |> ... |> fold f xsN
  4588 
  4589   fold f [x1, ..., xN] =
  4590     f x1 #> ... #> f xN
  4591 
  4592   (fold o fold) f [xs1, ..., xsN] =
  4593     fold f xs1 #> ... #> fold f xsN
  4594 
  4595 * Pure/library.ML: the following selectors on type 'a option are
  4596 available:
  4597 
  4598   the:               'a option -> 'a  (*partial*)
  4599   these:             'a option -> 'a  where 'a = 'b list
  4600   the_default: 'a -> 'a option -> 'a
  4601   the_list:          'a option -> 'a list
  4602 
  4603 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4604 basic operations for association lists, following natural argument
  4605 order; moreover the explicit equality predicate passed here avoids
  4606 potentially expensive polymorphic runtime equality checks.
  4607 The old functions may be expressed as follows:
  4608 
  4609   assoc = uncurry (AList.lookup (op =))
  4610   assocs = these oo AList.lookup (op =)
  4611   overwrite = uncurry (AList.update (op =)) o swap
  4612 
  4613 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4614 
  4615   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4616   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4617 
  4618 replacing make_keylist and keyfilter (occassionally used)
  4619 Naive rewrites:
  4620 
  4621   make_keylist = AList.make
  4622   keyfilter = AList.find (op =)
  4623 
  4624 * eq_fst and eq_snd now take explicit equality parameter, thus
  4625   avoiding eqtypes. Naive rewrites:
  4626 
  4627     eq_fst = eq_fst (op =)
  4628     eq_snd = eq_snd (op =)
  4629 
  4630 * Removed deprecated apl and apr (rarely used).
  4631   Naive rewrites:
  4632 
  4633     apl (n, op) =>>= curry op n
  4634     apr (op, m) =>>= fn n => op (n, m)
  4635 
  4636 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4637 provides a reasonably efficient light-weight implementation of sets as
  4638 lists.
  4639 
  4640 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4641 few new operations; existing lookup and update are now curried to
  4642 follow natural argument order (for use with fold etc.);
  4643 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4644 
  4645 * Pure/General: output via the Isabelle channels of
  4646 writeln/warning/error etc. is now passed through Output.output, with a
  4647 hook for arbitrary transformations depending on the print_mode
  4648 (cf. Output.add_mode -- the first active mode that provides a output
  4649 function wins).  Already formatted output may be embedded into further
  4650 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4651 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4652 accommodate easy composition of diagnostic messages etc.  Programmers
  4653 rarely need to care about Output.output or Output.raw at all, with
  4654 some notable exceptions: Output.output is required when bypassing the
  4655 standard channels (writeln etc.), or in token translations to produce
  4656 properly formatted results; Output.raw is required when capturing
  4657 already output material that will eventually be presented to the user
  4658 a second time.  For the default print mode, both Output.output and
  4659 Output.raw have no effect.
  4660 
  4661 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4662 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4663 cumulative results are displayed at the end of a batch session.
  4664 
  4665 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4666 replaced by File.platform_path and File.shell_path (with appropriate
  4667 hooks).  This provides a clean interface for unusual systems where the
  4668 internal and external process view of file names are different.
  4669 
  4670 * Pure: more efficient orders for basic syntactic entities: added
  4671 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4672 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4673 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4674 orders now -- potential INCOMPATIBILITY for code that depends on a
  4675 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4676 Library.sort_strings on result).
  4677 
  4678 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4679 fold_types traverse types/terms from left to right, observing natural
  4680 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4681 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4682 
  4683 * Pure: name spaces have been refined, with significant changes of the
  4684 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4685 to extern(_table).  The plain name entry path is superceded by a
  4686 general 'naming' context, which also includes the 'policy' to produce
  4687 a fully qualified name and external accesses of a fully qualified
  4688 name; NameSpace.extend is superceded by context dependent
  4689 Sign.declare_name.  Several theory and proof context operations modify
  4690 the naming context.  Especially note Theory.restore_naming and
  4691 ProofContext.restore_naming to get back to a sane state; note that
  4692 Theory.add_path is no longer sufficient to recover from
  4693 Theory.absolute_path in particular.
  4694 
  4695 * Pure: new flags short_names (default false) and unique_names
  4696 (default true) for controlling output of qualified names.  If
  4697 short_names is set, names are printed unqualified.  If unique_names is
  4698 reset, the name prefix is reduced to the minimum required to achieve
  4699 the original result when interning again, even if there is an overlap
  4700 with earlier declarations.
  4701 
  4702 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4703 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4704 (useful for printing error messages).  INCOMPATIBILITY.
  4705 
  4706 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4707 Theory.theory are now identified, referring to the universal
  4708 Context.theory (see Pure/context.ML).  Actual signature and theory
  4709 content is managed as theory data.  The old code and interfaces were
  4710 spread over many files and structures; the new arrangement introduces
  4711 considerable INCOMPATIBILITY to gain more clarity:
  4712 
  4713   Context -- theory management operations (name, identity, inclusion,
  4714     parents, ancestors, merge, etc.), plus generic theory data;
  4715 
  4716   Sign -- logical signature and syntax operations (declaring consts,
  4717     types, etc.), plus certify/read for common entities;
  4718 
  4719   Theory -- logical theory operations (stating axioms, definitions,
  4720     oracles), plus a copy of logical signature operations (consts,
  4721     types, etc.); also a few basic management operations (Theory.copy,
  4722     Theory.merge, etc.)
  4723 
  4724 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4725 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4726 for convenience -- they merely return the theory.
  4727 
  4728 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4729 
  4730 * Pure: the Isar proof context type is already defined early in Pure
  4731 as Context.proof (note that ProofContext.context and Proof.context are
  4732 aliases, where the latter is the preferred name).  This enables other
  4733 Isabelle components to refer to that type even before Isar is present.
  4734 
  4735 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4736 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4737 any of these kinds.  For example, Sign.intern typeK is now
  4738 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4739 Theory.hide_types.  Also note that former
  4740 Theory.hide_classes/types/consts are now
  4741 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4742 internalize their arguments!  INCOMPATIBILITY.
  4743 
  4744 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4745 datatype thmref (with constructors Name and NameSelection) instead of
  4746 plain string -- INCOMPATIBILITY;
  4747 
  4748 * Pure: cases produced by proof methods specify options, where NONE
  4749 means to remove case bindings -- INCOMPATIBILITY in
  4750 (RAW_)METHOD_CASES.
  4751 
  4752 * Pure: the following operations retrieve axioms or theorems from a
  4753 theory node or theory hierarchy, respectively:
  4754 
  4755   Theory.axioms_of: theory -> (string * term) list
  4756   Theory.all_axioms_of: theory -> (string * term) list
  4757   PureThy.thms_of: theory -> (string * thm) list
  4758   PureThy.all_thms_of: theory -> (string * thm) list
  4759 
  4760 * Pure: print_tac now outputs the goal through the trace channel.
  4761 
  4762 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4763 Reference Toplevel.debug (default false) controls detailed printing
  4764 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4765 controls execution profiling -- set to 1 for time and 2 for space
  4766 (both increase the runtime).
  4767 
  4768 * Isar session: The initial use of ROOT.ML is now always timed,
  4769 i.e. the log will show the actual process times, in contrast to the
  4770 elapsed wall-clock time that the outer shell wrapper produces.
  4771 
  4772 * Simplifier: improved handling of bound variables (nameless
  4773 representation, avoid allocating new strings).  Simprocs that invoke
  4774 the Simplifier recursively should use Simplifier.inherit_bounds to
  4775 avoid local name clashes.  Failure to do so produces warnings
  4776 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4777 for further details.
  4778 
  4779 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4780 bindings for all theorems stored within a given theory; this may help
  4781 in porting non-Isar theories to Isar ones, while keeping ML proof
  4782 scripts for the time being.
  4783 
  4784 * ML operator HTML.with_charset specifies the charset begin used for
  4785 generated HTML files.  For example:
  4786 
  4787   HTML.with_charset "utf-8" use_thy "Hebrew";
  4788   HTML.with_charset "utf-8" use_thy "Chinese";
  4789 
  4790 
  4791 *** System ***
  4792 
  4793 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4794 isabelle, isatool etc.).
  4795 
  4796 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4797 isatool doc, isatool mkdir, display_drafts etc.).
  4798 
  4799 * isatool usedir: option -f allows specification of the ML file to be
  4800 used by Isabelle; default is ROOT.ML.
  4801 
  4802 * New isatool version outputs the version identifier of the Isabelle
  4803 distribution being used.
  4804 
  4805 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4806 (containing Boolean satisfiability problems) into Isabelle/HOL
  4807 theories.
  4808 
  4809 
  4810 
  4811 New in Isabelle2004 (April 2004)
  4812 --------------------------------
  4813 
  4814 *** General ***
  4815 
  4816 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4817   Replaces linorder.ML.
  4818 
  4819 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4820   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4821   (\<a>...\<z>), are now considered normal letters, and can therefore
  4822   be used anywhere where an ASCII letter (a...zA...Z) has until
  4823   now. COMPATIBILITY: This obviously changes the parsing of some
  4824   terms, especially where a symbol has been used as a binder, say
  4825   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4826   as an identifier.  Fix it by inserting a space around former
  4827   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4828   existing theory and ML files.
  4829 
  4830 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4831 
  4832 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4833   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4834   a normal (but invisible) letter. For multiple letter subscripts repeat
  4835   \<^isub> like this: x\<^isub>1\<^isub>2.
  4836 
  4837 * Pure: There are now sub-/superscripts that can span more than one
  4838   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4839   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4840   superscript. The new control characters are not identifier parts.
  4841 
  4842 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4843   content of "..." to the latex file instead of \isacntrl... . The "..."
  4844   may consist of any printable characters excluding the end bracket >.
  4845 
  4846 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4847   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4848   declare constants "final", which prevents their being given a definition
  4849   later.  It is useful for constants whose behaviour is fixed axiomatically
  4850   rather than definitionally, such as the meta-logic connectives.
  4851 
  4852 * Pure: 'instance' now handles general arities with general sorts
  4853   (i.e. intersections of classes),
  4854 
  4855 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4856   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4857   It can be changed to alter the colors/layout of generated pages.
  4858 
  4859 
  4860 *** Isar ***
  4861 
  4862 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4863   cut_tac, subgoal_tac and thin_tac:
  4864   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4865     locales are no longer forced to write Isar proof scripts.
  4866     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4867     emulations.
  4868   - INCOMPATIBILITY: names of variables to be instantiated may no
  4869     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4870     This is consistent with the instantiation attribute "where".
  4871 
  4872 * Attributes "where" and "of":
  4873   - Now take type variables of instantiated theorem into account when reading
  4874     the instantiation string.  This fixes a bug that caused instantiated
  4875     theorems to have too special types in some circumstances.
  4876   - "where" permits explicit instantiations of type variables.
  4877 
  4878 * Calculation commands "moreover" and "also" no longer interfere with
  4879   current facts ("this"), admitting arbitrary combinations with "then"
  4880   and derived forms.
  4881 
  4882 * Locales:
  4883   - Goal statements involving the context element "includes" no longer
  4884     generate theorems with internal delta predicates (those ending on
  4885     "_axioms") in the premise.
  4886     Resolve particular premise with <locale>.intro to obtain old form.
  4887   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4888     specification and "includes" elements in goal statement.
  4889   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4890     [intro?] and [elim?] (respectively) by default.
  4891   - Experimental command for instantiation of locales in proof contexts:
  4892         instantiate <label>[<attrs>]: <loc>
  4893     Instantiates locale <loc> and adds all its theorems to the current context
  4894     taking into account their attributes.  Label and attrs are optional
  4895     modifiers, like in theorem declarations.  If present, names of
  4896     instantiated theorems are qualified with <label>, and the attributes
  4897     <attrs> are applied after any attributes these theorems might have already.
  4898       If the locale has assumptions, a chained fact of the form
  4899     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4900     are derived.  The command does not support old-style locales declared
  4901     with "locale (open)".
  4902       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4903 
  4904 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4905   (Isar) contexts.
  4906 
  4907 
  4908 *** HOL ***
  4909 
  4910 * Proof import: new image HOL4 contains the imported library from
  4911   the HOL4 system with about 2500 theorems. It is imported by
  4912   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4913   can be used like any other Isabelle image.  See
  4914   HOL/Import/HOL/README for more information.
  4915 
  4916 * Simplifier:
  4917   - Much improved handling of linear and partial orders.
  4918     Reasoners for linear and partial orders are set up for type classes
  4919     "linorder" and "order" respectively, and are added to the default simpset
  4920     as solvers.  This means that the simplifier can build transitivity chains
  4921     to solve goals from the assumptions.
  4922   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4923     of blast or auto after simplification become unnecessary because the goal
  4924     is solved by simplification already.
  4925 
  4926 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4927     all proved in axiomatic type classes for semirings, rings and fields.
  4928 
  4929 * Numerics:
  4930   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4931     now formalized using the Ring_and_Field theory mentioned above.
  4932   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4933     than before, because now they are set up once in a generic manner.
  4934   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4935     Look for the general versions in Ring_and_Field (and Power if they concern
  4936     exponentiation).
  4937 
  4938 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4939 
  4940 * Records:
  4941   - Record types are now by default printed with their type abbreviation
  4942     instead of the list of all field types. This can be configured via
  4943     the reference "print_record_type_abbr".
  4944   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4945     (not enabled by default).
  4946   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4947     EX x. x = sel r to True (not enabled by default).
  4948   - Tactic "record_split_simp_tac" to split and simplify records added.
  4949 
  4950 * 'specification' command added, allowing for definition by
  4951   specification.  There is also an 'ax_specification' command that
  4952   introduces the new constants axiomatically.
  4953 
  4954 * arith(_tac) is now able to generate counterexamples for reals as well.
  4955 
  4956 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4957 
  4958 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4959   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4960 
  4961 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4962   matrix theory to linear programming.
  4963 
  4964 * Unions and Intersections:
  4965   The latex output syntax of UN and INT has been changed
  4966   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4967   i.e. the index formulae has become a subscript.
  4968   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4969 
  4970 * Unions and Intersections over Intervals:
  4971   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4972   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4973   like in normal math, and corresponding versions for < and for intersection.
  4974 
  4975 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4976   lexicographic dictonary ordering has been added as "lexord".
  4977 
  4978 * ML: the legacy theory structures Int and List have been removed. They had
  4979   conflicted with ML Basis Library structures having the same names.
  4980 
  4981 * 'refute' command added to search for (finite) countermodels.  Only works
  4982   for a fragment of HOL.  The installation of an external SAT solver is
  4983   highly recommended.  See "HOL/Refute.thy" for details.
  4984 
  4985 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4986   formulae under an assignment of free variables to random values.
  4987   In contrast to 'refute', it can deal with inductive datatypes,
  4988   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4989   for examples.
  4990 
  4991 
  4992 *** HOLCF ***
  4993 
  4994 * Streams now come with concatenation and are part of the HOLCF image
  4995 
  4996 
  4997 
  4998 New in Isabelle2003 (May 2003)
  4999 ------------------------------
  5000 
  5001 *** General ***
  5002 
  5003 * Provers/simplifier:
  5004 
  5005   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5006     Assumptions are now subject to complete mutual simplification,
  5007     not just from left to right. The simplifier now preserves
  5008     the order of assumptions.
  5009 
  5010     Potential INCOMPATIBILITY:
  5011 
  5012     -- simp sometimes diverges where the old version did
  5013        not, e.g. invoking simp on the goal
  5014 
  5015         [| P (f x); y = x; f x = f y |] ==> Q
  5016 
  5017        now gives rise to the infinite reduction sequence
  5018 
  5019         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5020 
  5021        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5022        kind of problem.
  5023 
  5024     -- Tactics combining classical reasoner and simplification (such as auto)
  5025        are also affected by this change, because many of them rely on
  5026        simp. They may sometimes diverge as well or yield a different numbers
  5027        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5028        in case of problems. Sometimes subsequent calls to the classical
  5029        reasoner will fail because a preceeding call to the simplifier too
  5030        eagerly simplified the goal, e.g. deleted redundant premises.
  5031 
  5032   - The simplifier trace now shows the names of the applied rewrite rules
  5033 
  5034   - You can limit the number of recursive invocations of the simplifier
  5035     during conditional rewriting (where the simplifie tries to solve the
  5036     conditions before applying the rewrite rule):
  5037     ML "simp_depth_limit := n"
  5038     where n is an integer. Thus you can force termination where previously
  5039     the simplifier would diverge.
  5040 
  5041   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5042 
  5043   - No longer aborts on failed congruence proof.  Instead, the
  5044     congruence is ignored.
  5045 
  5046 * Pure: New generic framework for extracting programs from constructive
  5047   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5048   as HOL/Extraction for some case studies.
  5049 
  5050 * Pure: The main goal of the proof state is no longer shown by default, only
  5051 the subgoals. This behaviour is controlled by a new flag.
  5052    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5053 (ML: Proof.show_main_goal).
  5054 
  5055 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5056 rules whose conclusion matches subgoal 1:
  5057       PG menu: Isabelle/Isar -> Show me -> matching rules
  5058 The rules are ordered by how closely they match the subgoal.
  5059 In particular, rules that solve a subgoal outright are displayed first
  5060 (or rather last, the way they are printed).
  5061 (ML: ProofGeneral.print_intros())
  5062 
  5063 * Pure: New flag trace_unify_fail causes unification to print
  5064 diagnostic information (PG: in trace buffer) when it fails. This is
  5065 useful for figuring out why single step proofs like rule, erule or
  5066 assumption failed.
  5067 
  5068 * Pure: Locale specifications now produce predicate definitions
  5069 according to the body of text (covering assumptions modulo local
  5070 definitions); predicate "loc_axioms" covers newly introduced text,
  5071 while "loc" is cumulative wrt. all included locale expressions; the
  5072 latter view is presented only on export into the global theory
  5073 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5074 on the old view without predicates;
  5075 
  5076 * Pure: predefined locales "var" and "struct" are useful for sharing
  5077 parameters (as in CASL, for example); just specify something like
  5078 ``var x + var y + struct M'' as import;
  5079 
  5080 * Pure: improved thms_containing: proper indexing of facts instead of
  5081 raw theorems; check validity of results wrt. current name space;
  5082 include local facts of proof configuration (also covers active
  5083 locales), cover fixed variables in index; may use "_" in term
  5084 specification; an optional limit for the number of printed facts may
  5085 be given (the default is 40);
  5086 
  5087 * Pure: disallow duplicate fact bindings within new-style theory files
  5088 (batch-mode only);
  5089 
  5090 * Provers: improved induct method: assumptions introduced by case
  5091 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5092 the goal statement); "foo" still refers to all facts collectively;
  5093 
  5094 * Provers: the function blast.overloaded has been removed: all constants
  5095 are regarded as potentially overloaded, which improves robustness in exchange
  5096 for slight decrease in efficiency;
  5097 
  5098 * Provers/linorder: New generic prover for transitivity reasoning over
  5099 linear orders.  Note: this prover is not efficient!
  5100 
  5101 * Isar: preview of problems to finish 'show' now produce an error
  5102 rather than just a warning (in interactive mode);
  5103 
  5104 
  5105 *** HOL ***
  5106 
  5107 * arith(_tac)
  5108 
  5109  - Produces a counter example if it cannot prove a goal.
  5110    Note that the counter example may be spurious if the goal is not a formula
  5111    of quantifier-free linear arithmetic.
  5112    In ProofGeneral the counter example appears in the trace buffer.
  5113 
  5114  - Knows about div k and mod k where k is a numeral of type nat or int.
  5115 
  5116  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5117    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5118    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5119 
  5120 * simp's arithmetic capabilities have been enhanced a bit: it now
  5121 takes ~= in premises into account (by performing a case split);
  5122 
  5123 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5124 are distributed over a sum of terms;
  5125 
  5126 * New tactic "trans_tac" and method "trans" instantiate
  5127 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5128 "<=", "<" and "=").
  5129 
  5130 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5131 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5132 
  5133 * 'typedef' command has new option "open" to suppress the set
  5134 definition;
  5135 
  5136 * functions Min and Max on finite sets have been introduced (theory
  5137 Finite_Set);
  5138 
  5139 * attribute [symmetric] now works for relations as well; it turns
  5140 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5141 
  5142 * induct over a !!-quantified statement (say !!x1..xn):
  5143   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5144 
  5145 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5146 %x. None. Warning: empty_def now refers to the previously hidden definition
  5147 of the empty set.
  5148 
  5149 * Algebra: formalization of classical algebra.  Intended as base for
  5150 any algebraic development in Isabelle.  Currently covers group theory
  5151 (up to Sylow's theorem) and ring theory (Universal Property of
  5152 Univariate Polynomials).  Contributions welcome;
  5153 
  5154 * GroupTheory: deleted, since its material has been moved to Algebra;
  5155 
  5156 * Complex: new directory of the complex numbers with numeric constants,
  5157 nonstandard complex numbers, and some complex analysis, standard and
  5158 nonstandard (Jacques Fleuriot);
  5159 
  5160 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5161 
  5162 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5163 Fleuriot);
  5164 
  5165 * Real/HahnBanach: updated and adapted to locales;
  5166 
  5167 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5168 Gray and Kramer);
  5169 
  5170 * UNITY: added the Meier-Sanders theory of progress sets;
  5171 
  5172 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5173 as abstract algorithms, instantiated to the JVM;
  5174 
  5175 * Bali: Java source language formalization. Type system, operational
  5176 semantics, axiomatic semantics. Supported language features:
  5177 classes, interfaces, objects,virtual methods, static methods,
  5178 static/instance fields, arrays, access modifiers, definite
  5179 assignment, exceptions.
  5180 
  5181 
  5182 *** ZF ***
  5183 
  5184 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5185 universe, etc.);
  5186 
  5187 * Main ZF: virtually all theories converted to new-style format;
  5188 
  5189 
  5190 *** ML ***
  5191 
  5192 * Pure: Tactic.prove provides sane interface for internal proofs;
  5193 omits the infamous "standard" operation, so this is more appropriate
  5194 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5195 
  5196 * Pure: improved error reporting of simprocs;
  5197 
  5198 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5199 up simprocs;
  5200 
  5201 
  5202 *** Document preparation ***
  5203 
  5204 * uses \par instead of \\ for line breaks in theory text. This may
  5205 shift some page breaks in large documents. To get the old behaviour
  5206 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5207 
  5208 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5209 other packages
  5210 
  5211 * \<euro> now needs package babel/greek instead of marvosym (which
  5212 broke \Rightarrow)
  5213 
  5214 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5215 textcomp package)
  5216 
  5217 
  5218 
  5219 New in Isabelle2002 (March 2002)
  5220 --------------------------------
  5221 
  5222 *** Document preparation ***
  5223 
  5224 * greatly simplified document preparation setup, including more
  5225 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5226 instructive isatool mkdir; users should basically be able to get
  5227 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5228 users may run a separate document processing stage manually like this:
  5229 "isatool usedir -D output HOL Test && isatool document Test/output";
  5230 
  5231 * theory dependency graph may now be incorporated into documents;
  5232 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5233 with \includegraphics of LaTeX;
  5234 
  5235 * proper spacing of consecutive markup elements, especially text
  5236 blocks after section headings;
  5237 
  5238 * support bold style (for single symbols only), input syntax is like
  5239 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5240 
  5241 * \<bullet> is now output as bold \cdot by default, which looks much
  5242 better in printed text;
  5243 
  5244 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5245 note that these symbols are currently unavailable in Proof General /
  5246 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5247 
  5248 * isatool latex no longer depends on changed TEXINPUTS, instead
  5249 isatool document copies the Isabelle style files to the target
  5250 location;
  5251 
  5252 
  5253 *** Isar ***
  5254 
  5255 * Pure/Provers: improved proof by cases and induction;
  5256   - 'case' command admits impromptu naming of parameters (such as
  5257     "case (Suc n)");
  5258   - 'induct' method divinates rule instantiation from the inductive
  5259     claim; no longer requires excessive ?P bindings for proper
  5260     instantiation of cases;
  5261   - 'induct' method properly enumerates all possibilities of set/type
  5262     rules; as a consequence facts may be also passed through *type*
  5263     rules without further ado;
  5264   - 'induct' method now derives symbolic cases from the *rulified*
  5265     rule (before it used to rulify cases stemming from the internal
  5266     atomized version); this means that the context of a non-atomic
  5267     statement becomes is included in the hypothesis, avoiding the
  5268     slightly cumbersome show "PROP ?case" form;
  5269   - 'induct' may now use elim-style induction rules without chaining
  5270     facts, using ``missing'' premises from the goal state; this allows
  5271     rules stemming from inductive sets to be applied in unstructured
  5272     scripts, while still benefitting from proper handling of non-atomic
  5273     statements; NB: major inductive premises need to be put first, all
  5274     the rest of the goal is passed through the induction;
  5275   - 'induct' proper support for mutual induction involving non-atomic
  5276     rule statements (uses the new concept of simultaneous goals, see
  5277     below);
  5278   - append all possible rule selections, but only use the first
  5279     success (no backtracking);
  5280   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5281   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5282   - added 'print_induct_rules' (covered by help item in recent Proof
  5283     General versions);
  5284   - moved induct/cases attributes to Pure, methods to Provers;
  5285   - generic method setup instantiated for FOL and HOL;
  5286 
  5287 * Pure: support multiple simultaneous goal statements, for example
  5288 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5289 meta-level mechanism, this acts as if several individual goals had
  5290 been stated separately; in particular common proof methods need to be
  5291 repeated in order to cover all claims; note that a single elimination
  5292 step is *not* sufficient to establish the two conjunctions, so this
  5293 fails:
  5294 
  5295   assume "A & B" then have A and B ..   (*".." fails*)
  5296 
  5297 better use "obtain" in situations as above; alternative refer to
  5298 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5299 
  5300 * Pure: proper integration with ``locales''; unlike the original
  5301 version by Florian Kammller, Isar locales package high-level proof
  5302 contexts rather than raw logical ones (e.g. we admit to include
  5303 attributes everywhere); operations on locales include merge and
  5304 rename; support for implicit arguments (``structures''); simultaneous
  5305 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5306 some examples;
  5307 
  5308 * Pure: the following commands have been ``localized'', supporting a
  5309 target locale specification "(in name)": 'lemma', 'theorem',
  5310 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5311 stored both within the locale and at the theory level (exported and
  5312 qualified by the locale name);
  5313 
  5314 * Pure: theory goals may now be specified in ``long'' form, with
  5315 ad-hoc contexts consisting of arbitrary locale elements. for example
  5316 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5317 definitions may be given, too); the result is a meta-level rule with
  5318 the context elements being discharged in the obvious way;
  5319 
  5320 * Pure: new proof command 'using' allows to augment currently used
  5321 facts after a goal statement ('using' is syntactically analogous to
  5322 'apply', but acts on the goal's facts only); this allows chained facts
  5323 to be separated into parts given before and after a claim, as in
  5324 ``from a and b have C using d and e <proof>'';
  5325 
  5326 * Pure: renamed "antecedent" case to "rule_context";
  5327 
  5328 * Pure: new 'judgment' command records explicit information about the
  5329 object-logic embedding (used by several tools internally); no longer
  5330 use hard-wired "Trueprop";
  5331 
  5332 * Pure: added 'corollary' command;
  5333 
  5334 * Pure: fixed 'token_translation' command;
  5335 
  5336 * Pure: removed obsolete 'exported' attribute;
  5337 
  5338 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5339 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5340 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5341 
  5342 * Pure: method 'atomize' presents local goal premises as object-level
  5343 statements (atomic meta-level propositions); setup controlled via
  5344 rewrite rules declarations of 'atomize' attribute; example
  5345 application: 'induct' method with proper rule statements in improper
  5346 proof *scripts*;
  5347 
  5348 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5349 now consider the syntactic context of assumptions, giving a better
  5350 chance to get type-inference of the arguments right (this is
  5351 especially important for locales);
  5352 
  5353 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5354 mode;
  5355 
  5356 * Pure/obtain: the formal conclusion "thesis", being marked as
  5357 ``internal'', may no longer be reference directly in the text;
  5358 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5359 situations;
  5360 
  5361 * Pure: generic 'sym' attribute which declares a rule both as pure
  5362 'elim?' and for the 'symmetric' operation;
  5363 
  5364 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5365 text; the fixed correlation with particular command syntax has been
  5366 discontinued;
  5367 
  5368 * Pure: new method 'rules' is particularly well-suited for proof
  5369 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5370 but often produces more compact proof terms with less detours;
  5371 
  5372 * Pure/Provers/classical: simplified integration with pure rule
  5373 attributes and methods; the classical "intro?/elim?/dest?"
  5374 declarations coincide with the pure ones; the "rule" method no longer
  5375 includes classically swapped intros; "intro" and "elim" methods no
  5376 longer pick rules from the context; also got rid of ML declarations
  5377 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5378 INCOMPATIBILITY;
  5379 
  5380 * Provers/classical: attribute 'swapped' produces classical inversions
  5381 of introduction rules;
  5382 
  5383 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5384 rules instead of full simplifier context; 'iff' attribute handles
  5385 conditional rules;
  5386 
  5387 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5388 
  5389 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5390 "(permissive)" option to recover old behavior;
  5391 
  5392 * HOL: 'inductive' no longer features separate (collective) attributes
  5393 for 'intros' (was found too confusing);
  5394 
  5395 * HOL: properly declared induction rules less_induct and
  5396 wf_induct_rule;
  5397 
  5398 
  5399 *** HOL ***
  5400 
  5401 * HOL: moved over to sane numeral syntax; the new policy is as
  5402 follows:
  5403 
  5404   - 0 and 1 are polymorphic constants, which are defined on any
  5405   numeric type (nat, int, real etc.);
  5406 
  5407   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5408   binary representation internally;
  5409 
  5410   - type nat has special constructor Suc, and generally prefers Suc 0
  5411   over 1::nat and Suc (Suc 0) over 2::nat;
  5412 
  5413 This change may cause significant problems of INCOMPATIBILITY; here
  5414 are some hints on converting existing sources:
  5415 
  5416   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5417   entities, so expressions involving "-" (unary or binary minus) need
  5418   to be spaced properly;
  5419 
  5420   - existing occurrences of "1" may need to be constraint "1::nat" or
  5421   even replaced by Suc 0; similar for old "2";
  5422 
  5423   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5424 
  5425   - remove all special provisions on numerals in proofs;
  5426 
  5427 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5428 representation (depends on bin_arith_simps in the default context);
  5429 
  5430 * HOL: symbolic syntax for x^2 (numeral 2);
  5431 
  5432 * HOL: the class of all HOL types is now called "type" rather than
  5433 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5434 in axclass/classes, instance/arities, and (usually rare) occurrences
  5435 in typings (of consts etc.); internally the class is called
  5436 "HOL.type", ML programs should refer to HOLogic.typeS;
  5437 
  5438 * HOL/record package improvements:
  5439   - new derived operations "fields" to build a partial record section,
  5440     "extend" to promote a fixed record to a record scheme, and
  5441     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5442     declared as simp by default;
  5443   - shared operations ("more", "fields", etc.) now need to be always
  5444     qualified) --- potential INCOMPATIBILITY;
  5445   - removed "make_scheme" operations (use "make" with "extend") --
  5446     INCOMPATIBILITY;
  5447   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5448   - provides cases/induct rules for use with corresponding Isar
  5449     methods (for concrete records, record schemes, concrete more
  5450     parts, and schematic more parts -- in that order);
  5451   - internal definitions directly based on a light-weight abstract
  5452     theory of product types over typedef rather than datatype;
  5453 
  5454 * HOL: generic code generator for generating executable ML code from
  5455 specifications; specific support for HOL constructs such as inductive
  5456 datatypes and sets, as well as recursive functions; can be invoked
  5457 via 'generate_code' theory section;
  5458 
  5459 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5460 
  5461 * HOL: consolidated and renamed several theories.  In particular:
  5462         Ord.thy has been absorbed into HOL.thy
  5463         String.thy has been absorbed into List.thy
  5464 
  5465 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5466 (beware of argument permutation!);
  5467 
  5468 * HOL: linorder_less_split superseded by linorder_cases;
  5469 
  5470 * HOL/List: "nodups" renamed to "distinct";
  5471 
  5472 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5473 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5474   - Ex_def has changed, now need to use some_eq_ex
  5475 
  5476 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5477 in this (rare) case use:
  5478 
  5479   delSWrapper "split_all_tac"
  5480   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5481 
  5482 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5483 MAY FAIL;
  5484 
  5485 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5486 Isabelle's type classes, ^ on functions and relations has too general
  5487 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5488 necessary to attach explicit type constraints;
  5489 
  5490 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5491 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5492 renamed accordingly (eg "compI" -> "rel_compI").
  5493 
  5494 * HOL: syntax translations now work properly with numerals and records
  5495 expressions;
  5496 
  5497 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5498 of "lam" -- INCOMPATIBILITY;
  5499 
  5500 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5501 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5502 renamed "Product_Type.unit";
  5503 
  5504 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5505 
  5506 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5507 the "cases" method);
  5508 
  5509 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5510 Florian Kammller);
  5511 
  5512 * HOL/IMP: updated and converted to new-style theory format; several
  5513 parts turned into readable document, with proper Isar proof texts and
  5514 some explanations (by Gerwin Klein);
  5515 
  5516 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5517 
  5518 * HOL-Hyperreal is now a logic image;
  5519 
  5520 
  5521 *** HOLCF ***
  5522 
  5523 * Isar: consts/constdefs supports mixfix syntax for continuous
  5524 operations;
  5525 
  5526 * Isar: domain package adapted to new-style theory format, e.g. see
  5527 HOLCF/ex/Dnat.thy;
  5528 
  5529 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5530 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5531 lift.induct_tac, always use UU instead of Undef;
  5532 
  5533 * HOLCF/IMP: updated and converted to new-style theory;
  5534 
  5535 
  5536 *** ZF ***
  5537 
  5538 * Isar: proper integration of logic-specific tools and packages,
  5539 including theory commands '(co)inductive', '(co)datatype',
  5540 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5541 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5542 
  5543 * theory Main no longer includes AC; for the Axiom of Choice, base
  5544 your theory on Main_ZFC;
  5545 
  5546 * the integer library now covers quotients and remainders, with many
  5547 laws relating division to addition, multiplication, etc.;
  5548 
  5549 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5550 typeless version of the formalism;
  5551 
  5552 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5553 format;
  5554 
  5555 * ZF/Induct: new directory for examples of inductive definitions,
  5556 including theory Multiset for multiset orderings; converted to
  5557 new-style theory format;
  5558 
  5559 * ZF: many new theorems about lists, ordinals, etc.;
  5560 
  5561 
  5562 *** General ***
  5563 
  5564 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5565 variable proof controls level of detail: 0 = no proofs (only oracle
  5566 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5567 also ref manual for further ML interfaces;
  5568 
  5569 * Pure/axclass: removed obsolete ML interface
  5570 goal_subclass/goal_arity;
  5571 
  5572 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5573 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5574 separate tokens, so expressions involving minus need to be spaced
  5575 properly;
  5576 
  5577 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5578 rather than "infixl" or "infixr";
  5579 
  5580 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5581 sort constraint specifications in type inference; e.g. "x::_::foo"
  5582 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5583 type variable);
  5584 
  5585 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5586 control output of nested => (types); the default behavior is
  5587 "type_brackets";
  5588 
  5589 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5590 tokens into AST constants;
  5591 
  5592 * Pure/syntax: prefer later declarations of translations and print
  5593 translation functions; potential INCOMPATIBILITY: need to reverse
  5594 multiple declarations for same syntax element constant;
  5595 
  5596 * Pure/show_hyps reset by default (in accordance to existing Isar
  5597 practice);
  5598 
  5599 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5600 addSafter;
  5601 
  5602 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5603 as well;
  5604 
  5605 * system: tested support for MacOS X; should be able to get Isabelle +
  5606 Proof General to work in a plain Terminal after installing Poly/ML
  5607 (e.g. from the Isabelle distribution area) and GNU bash alone
  5608 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5609 support requires further installations, e.g. from
  5610 http://fink.sourceforge.net/);
  5611 
  5612 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5613 
  5614 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5615 of 40 MB), cf. ML_OPTIONS;
  5616 
  5617 * system: Proof General keywords specification is now part of the
  5618 Isabelle distribution (see etc/isar-keywords.el);
  5619 
  5620 * system: support for persistent Proof General sessions (refrain from
  5621 outdating all loaded theories on startup); user may create writable
  5622 logic images like this: ``isabelle -q HOL Test'';
  5623 
  5624 * system: smart selection of Isabelle process versus Isabelle
  5625 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5626 run both "isabelle" and "Isabelle" even if file names are badly
  5627 damaged (executable inspects the case of the first letter of its own
  5628 name); added separate "isabelle-process" and "isabelle-interface";
  5629 
  5630 * system: refrain from any attempt at filtering input streams; no
  5631 longer support ``8bit'' encoding of old isabelle font, instead proper
  5632 iso-latin characters may now be used; the related isatools
  5633 "symbolinput" and "nonascii" have disappeared as well;
  5634 
  5635 * system: removed old "xterm" interface (the print modes "xterm" and
  5636 "xterm_color" are still available for direct use in a suitable
  5637 terminal);
  5638 
  5639 
  5640 
  5641 New in Isabelle99-2 (February 2001)
  5642 -----------------------------------
  5643 
  5644 *** Overview of INCOMPATIBILITIES ***
  5645 
  5646 * HOL: please note that theories in the Library and elsewhere often use the
  5647 new-style (Isar) format; to refer to their theorems in an ML script you must
  5648 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5649 
  5650 * HOL: inductive package no longer splits induction rule aggressively,
  5651 but only as far as specified by the introductions given; the old
  5652 format may be recovered via ML function complete_split_rule or attribute
  5653 'split_rule (complete)';
  5654 
  5655 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5656 gfp_Tarski to gfp_unfold;
  5657 
  5658 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5659 
  5660 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5661 relation); infix "^^" has been renamed "``"; infix "``" has been
  5662 renamed "`"; "univalent" has been renamed "single_valued";
  5663 
  5664 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5665 operation;
  5666 
  5667 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5668 
  5669 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5670 
  5671 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5672 consequence, it is no longer monotonic wrt. the local goal context
  5673 (which is now passed through the inductive cases);
  5674 
  5675 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5676 \<gg> to \<ggreater>;
  5677 
  5678 
  5679 *** Document preparation ***
  5680 
  5681 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5682 available: are "it" for near math-mode best-style output, "sl" for
  5683 slanted text style, and "tt" for plain type-writer; if no
  5684 \isabellestyle command is given, output is according to slanted
  5685 type-writer);
  5686 
  5687 * support sub/super scripts (for single symbols only), input syntax is
  5688 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5689 
  5690 * some more standard symbols; see Appendix A of the system manual for
  5691 the complete list of symbols defined in isabellesym.sty;
  5692 
  5693 * improved isabelle style files; more abstract symbol implementation
  5694 (should now use \isamath{...} and \isatext{...} in custom symbol
  5695 definitions);
  5696 
  5697 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5698 state; Note that presentation of goal states does not conform to
  5699 actual human-readable proof documents.  Please do not include goal
  5700 states into document output unless you really know what you are doing!
  5701 
  5702 * proper indentation of antiquoted output with proportional LaTeX
  5703 fonts;
  5704 
  5705 * no_document ML operator temporarily disables LaTeX document
  5706 generation;
  5707 
  5708 * isatool unsymbolize tunes sources for plain ASCII communication;
  5709 
  5710 
  5711 *** Isar ***
  5712 
  5713 * Pure: Isar now suffers initial goal statements to contain unbound
  5714 schematic variables (this does not conform to actual readable proof
  5715 documents, due to unpredictable outcome and non-compositional proof
  5716 checking); users who know what they are doing may use schematic goals
  5717 for Prolog-style synthesis of proven results;
  5718 
  5719 * Pure: assumption method (an implicit finishing) now handles actual
  5720 rules as well;
  5721 
  5722 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5723 initial goal, declare "that" only as Pure intro (only for single
  5724 steps); the "that" rule assumption may now be involved in implicit
  5725 finishing, thus ".." becomes a feasible for trivial obtains;
  5726 
  5727 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5728 instance proofs may be performed by "..";
  5729 
  5730 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5731 statements as well;
  5732 
  5733 * Pure: more robust selection of calculational rules;
  5734 
  5735 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5736 rule (as well as the assumption rule);
  5737 
  5738 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5739 lemmas, using the graph browser tool;
  5740 
  5741 * Pure: predict failure of "show" in interactive mode;
  5742 
  5743 * Pure: 'thms_containing' now takes actual terms as arguments;
  5744 
  5745 * HOL: improved method 'induct' --- now handles non-atomic goals
  5746 (potential INCOMPATIBILITY); tuned error handling;
  5747 
  5748 * HOL: cases and induct rules now provide explicit hints about the
  5749 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5750 any remaining facts are inserted into the goal verbatim;
  5751 
  5752 * HOL: local contexts (aka cases) may now contain term bindings as
  5753 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5754 the result to be shown in each case;
  5755 
  5756 * HOL: added 'recdef_tc' command;
  5757 
  5758 * isatool convert assists in eliminating legacy ML scripts;
  5759 
  5760 
  5761 *** HOL ***
  5762 
  5763 * HOL/Library: a collection of generic theories to be used together
  5764 with main HOL; the theory loader path already includes this directory
  5765 by default; the following existing theories have been moved here:
  5766 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5767 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5768 
  5769 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5770 modelling and verification task performed in Isabelle/HOL +
  5771 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5772 
  5773 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5774 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5775 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5776 'domain', this makes the theory consistent with mathematical
  5777 literature;
  5778 
  5779 * HOL basics: added overloaded operations "inverse" and "divide"
  5780 (infix "/"), syntax for generic "abs" operation, generic summation
  5781 operator \<Sum>;
  5782 
  5783 * HOL/typedef: simplified package, provide more useful rules (see also
  5784 HOL/subset.thy);
  5785 
  5786 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5787 now expressed as a proper nested rule (old-style tactic scripts may
  5788 require atomize_strip_tac to cope with non-atomic premises);
  5789 
  5790 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5791 to "split_conv" (old name still available for compatibility);
  5792 
  5793 * HOL: improved concrete syntax for strings (e.g. allows translation
  5794 rules with string literals);
  5795 
  5796 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5797  and Fleuriot's mechanization of analysis, including the transcendental
  5798  functions for the reals;
  5799 
  5800 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5801 
  5802 
  5803 *** CTT ***
  5804 
  5805 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5806 "lam" is displayed as TWO lambda-symbols
  5807 
  5808 * CTT: theory Main now available, containing everything (that is, Bool
  5809 and Arith);
  5810 
  5811 
  5812 *** General ***
  5813 
  5814 * Pure: the Simplifier has been implemented properly as a derived rule
  5815 outside of the actual kernel (at last!); the overall performance
  5816 penalty in practical applications is about 50%, while reliability of
  5817 the Isabelle inference kernel has been greatly improved;
  5818 
  5819 * print modes "brackets" and "no_brackets" control output of nested =>
  5820 (types) and ==> (props); the default behaviour is "brackets";
  5821 
  5822 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5823 as assumptions as well;
  5824 
  5825 * system: support Poly/ML 4.0;
  5826 
  5827 * system: isatool install handles KDE version 1 or 2;
  5828 
  5829 
  5830 
  5831 New in Isabelle99-1 (October 2000)
  5832 ----------------------------------
  5833 
  5834 *** Overview of INCOMPATIBILITIES ***
  5835 
  5836 * HOL: simplification of natural numbers is much changed; to partly
  5837 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5838 issue the following ML commands:
  5839 
  5840   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5841   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5842 
  5843 * HOL: simplification no longer dives into case-expressions; this is
  5844 controlled by "t.weak_case_cong" for each datatype t;
  5845 
  5846 * HOL: nat_less_induct renamed to less_induct;
  5847 
  5848 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5849 fixsome to patch .thy and .ML sources automatically;
  5850 
  5851   select_equality  -> some_equality
  5852   select_eq_Ex     -> some_eq_ex
  5853   selectI2EX       -> someI2_ex
  5854   selectI2         -> someI2
  5855   selectI          -> someI
  5856   select1_equality -> some1_equality
  5857   Eps_sym_eq       -> some_sym_eq_trivial
  5858   Eps_eq           -> some_eq_trivial
  5859 
  5860 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5861 
  5862 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5863 instead);
  5864 
  5865 * HOL: the recursion equations generated by 'recdef' are now called
  5866 f.simps instead of f.rules;
  5867 
  5868 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5869 
  5870 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5871 sometimes be needed;
  5872 
  5873 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5874 
  5875 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5876 
  5877 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5878 product is now "<*>" instead of "Times"; the lexicographic product is
  5879 now "<*lex*>" instead of "**";
  5880 
  5881 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5882 of main HOL, but was unused); better use HOL's datatype package;
  5883 
  5884 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5885 the old syntax may be recovered as follows:
  5886 
  5887   syntax (symbols)
  5888     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5889       (infixl "\\<oplus>" 100)
  5890 
  5891 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5892 
  5893 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5894 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5895 internally;
  5896 
  5897 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5898 changed from A/r to A//r;
  5899 
  5900 * ZF: new treatment of arithmetic (nat & int) may break some old
  5901 proofs;
  5902 
  5903 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5904 rulify -> rule_format, elimify -> elim_format, ...);
  5905 
  5906 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5907 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5908 should have to change intro!! to intro? only); replaced "delrule" by
  5909 "rule del";
  5910 
  5911 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5912 
  5913 * Provers: strengthened force_tac by using new first_best_tac;
  5914 
  5915 * LaTeX document preparation: several changes of isabelle.sty (see
  5916 lib/texinputs);
  5917 
  5918 
  5919 *** Document preparation ***
  5920 
  5921 * formal comments (text blocks etc.) in new-style theories may now
  5922 contain antiquotations of thm/prop/term/typ/text to be presented
  5923 according to latex print mode; concrete syntax is like this:
  5924 @{term[show_types] "f(x) = a + x"};
  5925 
  5926 * isatool mkdir provides easy setup of Isabelle session directories,
  5927 including proper document sources;
  5928 
  5929 * generated LaTeX sources are now deleted after successful run
  5930 (isatool document -c); may retain a copy somewhere else via -D option
  5931 of isatool usedir;
  5932 
  5933 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5934 style files, achieving self-contained LaTeX sources and simplifying
  5935 LaTeX debugging;
  5936 
  5937 * old-style theories now produce (crude) LaTeX output as well;
  5938 
  5939 * browser info session directories are now self-contained (may be put
  5940 on WWW server seperately); improved graphs of nested sessions; removed
  5941 graph for 'all sessions';
  5942 
  5943 * several improvements in isabelle style files; \isabellestyle{it}
  5944 produces fake math mode output; \isamarkupheader is now \section by
  5945 default; see lib/texinputs/isabelle.sty etc.;
  5946 
  5947 
  5948 *** Isar ***
  5949 
  5950 * Isar/Pure: local results and corresponding term bindings are now
  5951 subject to Hindley-Milner polymorphism (similar to ML); this
  5952 accommodates incremental type-inference very nicely;
  5953 
  5954 * Isar/Pure: new derived language element 'obtain' supports
  5955 generalized existence reasoning;
  5956 
  5957 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5958 support accumulation of results, without applying any rules yet;
  5959 useful to collect intermediate results without explicit name
  5960 references, and for use with transitivity rules with more than 2
  5961 premises;
  5962 
  5963 * Isar/Pure: scalable support for case-analysis type proofs: new
  5964 'case' language element refers to local contexts symbolically, as
  5965 produced by certain proof methods; internally, case names are attached
  5966 to theorems as "tags";
  5967 
  5968 * Isar/Pure: theory command 'hide' removes declarations from
  5969 class/type/const name spaces;
  5970 
  5971 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5972 indicate potential overloading;
  5973 
  5974 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5975 
  5976 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5977 "{a,b,c}" instead of {a,b,c};
  5978 
  5979 * Isar/Pure now provides its own version of intro/elim/dest
  5980 attributes; useful for building new logics, but beware of confusion
  5981 with the version in Provers/classical;
  5982 
  5983 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5984 case name 'antecedent';
  5985 
  5986 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5987 to the current context is now done automatically);
  5988 
  5989 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5990 for definining proof methods in ML;
  5991 
  5992 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5993 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5994 most cases, one should have to change intro!! to intro? only);
  5995 replaced "delrule" by "rule del";
  5996 
  5997 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5998 'symmetric' attribute (the latter supercedes [RS sym]);
  5999 
  6000 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6001 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6002 well (including splits);
  6003 
  6004 * Isar/Provers: Simplifier and Classical methods now support all kind
  6005 of modifiers used in the past, including 'cong', 'iff', etc.
  6006 
  6007 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6008 of Simplifier and Classical reasoner);
  6009 
  6010 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6011 now support named cases; major packages (inductive, datatype, primrec,
  6012 recdef) support case names and properly name parameters;
  6013 
  6014 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6015 monotonicity conditions are extracted to be proven at end of
  6016 calculations;
  6017 
  6018 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6019 method anyway;
  6020 
  6021 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6022 split_if split_if_asm; datatype package provides theorems foo.splits =
  6023 foo.split foo.split_asm for each datatype;
  6024 
  6025 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6026 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6027 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6028 use "(cases (simplified))" method in proper proof texts);
  6029 
  6030 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6031 
  6032 * Isar: names of theorems etc. may be natural numbers as well;
  6033 
  6034 * Isar: 'pr' command: optional arguments for goals_limit and
  6035 ProofContext.prems_limit; no longer prints theory contexts, but only
  6036 proof states;
  6037 
  6038 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6039 additional print modes to be specified; e.g. "pr(latex)" will print
  6040 proof state according to the Isabelle LaTeX style;
  6041 
  6042 * Isar: improved support for emulating tactic scripts, including proof
  6043 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6044 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6045 (for HOL datatypes);
  6046 
  6047 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6048 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6049 'proof method scripts' have to be in depth-first order;
  6050 
  6051 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6052 
  6053 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6054 should instead use individual commands for printing items
  6055 (print_commands, print_methods etc.);
  6056 
  6057 * Isar: added 'nothing' --- the empty list of theorems;
  6058 
  6059 
  6060 *** HOL ***
  6061 
  6062 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6063 corresponding virtual machine and a specification of its bytecode
  6064 verifier and a lightweight bytecode verifier, including proofs of
  6065 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6066 Cornelia Pusch (see also the homepage of project Bali at
  6067 http://isabelle.in.tum.de/Bali/);
  6068 
  6069 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6070 Clemens Ballarin;
  6071 
  6072 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6073 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6074 Rasmussen;
  6075 
  6076 * HOL/Lattice: fundamental concepts of lattice theory and order
  6077 structures, including duals, properties of bounds versus algebraic
  6078 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6079 Theorem for complete lattices etc.; may also serve as a demonstration
  6080 for abstract algebraic reasoning using axiomatic type classes, and
  6081 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6082 
  6083 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6084 von Oheimb;
  6085 
  6086 * HOL/IMPP: extension of IMP with local variables and mutually
  6087 recursive procedures, by David von Oheimb;
  6088 
  6089 * HOL/Lambda: converted into new-style theory and document;
  6090 
  6091 * HOL/ex/Multiquote: example of multiple nested quotations and
  6092 anti-quotations -- basically a generalized version of de-Bruijn
  6093 representation; very useful in avoiding lifting of operations;
  6094 
  6095 * HOL/record: added general record equality rule to simpset; fixed
  6096 select-update simplification procedure to handle extended records as
  6097 well; admit "r" as field name;
  6098 
  6099 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6100 other numeric types and also as the identity of groups, rings, etc.;
  6101 
  6102 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6103 Types nat and int belong to this axclass;
  6104 
  6105 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6106    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6107    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6108   two terms #m*u and #n*u are replaced by #(m+n)*u
  6109     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6110   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6111     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6112 
  6113 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6114 powerful prover for predicate logic but knows nothing of clasets; see
  6115 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6116 
  6117 * HOL: new version of "case_tac" subsumes both boolean case split and
  6118 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6119 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6120 
  6121 * HOL: simplification no longer dives into case-expressions: only the
  6122 selector expression is simplified, but not the remaining arms; to
  6123 enable full simplification of case-expressions for datatype t, you may
  6124 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6125 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6126 
  6127 * HOL/recdef: the recursion equations generated by 'recdef' for
  6128 function 'f' are now called f.simps instead of f.rules; if all
  6129 termination conditions are proved automatically, these simplification
  6130 rules are added to the simpset, as in primrec; rules may be named
  6131 individually as well, resulting in a separate list of theorems for
  6132 each equation;
  6133 
  6134 * HOL/While is a new theory that provides a while-combinator. It
  6135 permits the definition of tail-recursive functions without the
  6136 provision of a termination measure. The latter is necessary once the
  6137 invariant proof rule for while is applied.
  6138 
  6139 * HOL: new (overloaded) notation for the set of elements below/above
  6140 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6141 
  6142 * HOL: theorems impI, allI, ballI bound as "strip";
  6143 
  6144 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6145 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6146 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6147 
  6148 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6149 
  6150 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6151 main HOL, but was unused);
  6152 
  6153 * HOL: fewer consts declared as global (e.g. have to refer to
  6154 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6155 
  6156 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6157 in case of overlap with user translations (e.g. judgements over
  6158 tuples); (note that the underlying logical represenation is still
  6159 bogus);
  6160 
  6161 
  6162 *** ZF ***
  6163 
  6164 * ZF: simplification automatically cancels common terms in arithmetic
  6165 expressions over nat and int;
  6166 
  6167 * ZF: new treatment of nat to minimize type-checking: all operators
  6168 coerce their operands to a natural number using the function natify,
  6169 making the algebraic laws unconditional;
  6170 
  6171 * ZF: as above, for int: operators coerce their operands to an integer
  6172 using the function intify;
  6173 
  6174 * ZF: the integer library now contains many of the usual laws for the
  6175 orderings, including $<=, and monotonicity laws for $+ and $*;
  6176 
  6177 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6178 simplification;
  6179 
  6180 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6181 to the simplifier and classical reasoner simultaneously;
  6182 
  6183 
  6184 *** General ***
  6185 
  6186 * Provers: blast_tac now handles actual object-logic rules as
  6187 assumptions; note that auto_tac uses blast_tac internally as well;
  6188 
  6189 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6190 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6191 
  6192 * Provers: delrules now handles destruct rules as well (no longer need
  6193 explicit make_elim);
  6194 
  6195 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6196   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6197 use instead the strong form,
  6198   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6199 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6200 from destruct-rules;
  6201 
  6202 * Provers: Simplifier.easy_setup provides a fast path to basic
  6203 Simplifier setup for new object-logics;
  6204 
  6205 * Pure: AST translation rules no longer require constant head on LHS;
  6206 
  6207 * Pure: improved name spaces: ambiguous output is qualified; support
  6208 for hiding of names;
  6209 
  6210 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6211 XSYMBOL_HOME; no longer need to do manual configuration in most
  6212 situations;
  6213 
  6214 * system: compression of ML heaps images may now be controlled via -c
  6215 option of isabelle and isatool usedir (currently only observed by
  6216 Poly/ML);
  6217 
  6218 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6219 useful for remote X11);
  6220 
  6221 * system: provide TAGS file for Isabelle sources;
  6222 
  6223 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6224 order;
  6225 
  6226 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6227 timing flag supersedes proof_timing and Toplevel.trace;
  6228 
  6229 * ML: new combinators |>> and |>>> for incremental transformations
  6230 with secondary results (e.g. certain theory extensions):
  6231