NEWS
author haftmann
Tue Aug 17 14:33:39 2010 +0200 (2010-08-17)
changeset 38461 75fc4087764e
parent 38347 19000bb11ff5
child 38470 484e483eb606
child 38522 de7984a7172b
child 38535 9f64860c6ec0
permissions -rw-r--r--
NEWS and CONTRIBUTORS
     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 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    39 INCOMPATIBILITY.
    40 
    41 * Quickcheck in locales considers interpretations of that locale for
    42 counter example search.
    43 
    44 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    45 in Library/State_Monad has been changed to avoid ambiguities.
    46 INCOMPATIBILITY.
    47 
    48 * Code generator: export_code without explicit file declaration prints
    49 to standard output.  INCOMPATIBILITY.
    50 
    51 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
    52 respectively.  INCOMPATIBILITY.
    53 
    54 * Constant "split" has been merged with constant "prod_case";  names
    55 of ML functions, facts etc. involving split have been retained so far,
    56 though.  INCOMPATIBILITY.
    57 
    58 * Dropped old infix syntax "mem" for List.member;  use "in set"
    59 instead.  INCOMPATIBILITY.
    60 
    61 * Refactoring of code-generation specific operations in List.thy
    62 
    63   constants
    64     null ~> List.null
    65 
    66   facts
    67     mem_iff ~> member_def
    68     null_empty ~> null_def
    69 
    70 INCOMPATIBILITY.  Note that these were not suppossed to be used
    71 regularly unless for striking reasons;  their main purpose was code
    72 generation.
    73 
    74 * Some previously unqualified names have been qualified:
    75 
    76   types
    77     nat ~> Nat.nat
    78 
    79   constants
    80     Ball ~> Set.Ball
    81     Bex ~> Set.Bex
    82     Suc ~> Nat.Suc
    83     Pair ~> Product_Type.Pair
    84     fst ~> Product_Type.fst
    85     snd ~> Product_Type.snd
    86     curry ~> Product_Type.curry
    87     op : ~> Set.member
    88     Collect ~> Set.Collect
    89 
    90 INCOMPATIBILITY.
    91 
    92 * Removed simplifier congruence rule of "prod_case", as has for long
    93 been the case with "split".
    94 
    95 * Datatype package: theorems generated for executable equality
    96 (class eq) carry proper names and are treated as default code
    97 equations.
    98 
    99 * List.thy: use various operations from the Haskell prelude when
   100 generating Haskell code.
   101 
   102 * code_simp.ML: simplification with rules determined by
   103 code generator.
   104 
   105 * code generator: do not print function definitions for case
   106 combinators any longer.
   107 
   108 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   109 theorems are now stated in terms of euclidean spaces instead of finite
   110 cartesian products.
   111 
   112   types
   113     real ^ 'n ~>  'a::real_vector
   114               ~>  'a::euclidean_space
   115               ~>  'a::ordered_euclidean_space
   116         (depends on your needs)
   117 
   118   constants
   119      _ $ _        ~> _ $$ _
   120      \<chi> x. _  ~> \<chi>\<chi> x. _
   121      CARD('n)     ~> DIM('a)
   122 
   123 Also note that the indices are now natural numbers and not from some finite
   124 type. Finite cartesian products of euclidean spaces, products of euclidean
   125 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   126 
   127 INCOMPATIBILITY.
   128 
   129 * Inductive package: offers new command "inductive_simps" to automatically
   130 derive instantiated and simplified equations for inductive predicates,
   131 similar to inductive_cases.
   132 
   133 
   134 *** ML ***
   135 
   136 * ML antiquotations @{theory} and @{theory_ref} refer to named
   137 theories from the ancestry of the current context, not any accidental
   138 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   139 change in semantics.
   140 
   141 
   142 
   143 New in Isabelle2009-2 (June 2010)
   144 ---------------------------------
   145 
   146 *** General ***
   147 
   148 * Authentic syntax for *all* logical entities (type classes, type
   149 constructors, term constants): provides simple and robust
   150 correspondence between formal entities and concrete syntax.  Within
   151 the parse tree / AST representations, "constants" are decorated by
   152 their category (class, type, const) and spelled out explicitly with
   153 their full internal name.
   154 
   155 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   156 and translations (translation rules and translation functions in ML).
   157 Some hints on upgrading:
   158 
   159   - Many existing uses of 'syntax' and 'translations' can be replaced
   160     by more modern 'type_notation', 'notation' and 'abbreviation',
   161     which are independent of this issue.
   162 
   163   - 'translations' require markup within the AST; the term syntax
   164     provides the following special forms:
   165 
   166       CONST c   -- produces syntax version of constant c from context
   167       XCONST c  -- literally c, checked as constant from context
   168       c         -- literally c, if declared by 'syntax'
   169 
   170     Plain identifiers are treated as AST variables -- occasionally the
   171     system indicates accidental variables via the error "rhs contains
   172     extra variables".
   173 
   174     Type classes and type constructors are marked according to their
   175     concrete syntax.  Some old translations rules need to be written
   176     for the "type" category, using type constructor application
   177     instead of pseudo-term application of the default category
   178     "logic".
   179 
   180   - 'parse_translation' etc. in ML may use the following
   181     antiquotations:
   182 
   183       @{class_syntax c}   -- type class c within parse tree / AST
   184       @{term_syntax c}    -- type constructor c within parse tree / AST
   185       @{const_syntax c}   -- ML version of "CONST c" above
   186       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   187 
   188   - Literal types within 'typed_print_translations', i.e. those *not*
   189     represented as pseudo-terms are represented verbatim.  Use @{class
   190     c} or @{type_name c} here instead of the above syntax
   191     antiquotations.
   192 
   193 Note that old non-authentic syntax was based on unqualified base
   194 names, so all of the above "constant" names would coincide.  Recall
   195 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   196 diagnose syntax problems.
   197 
   198 * Type constructors admit general mixfix syntax, not just infix.
   199 
   200 * Concrete syntax may be attached to local entities without a proof
   201 body, too.  This works via regular mixfix annotations for 'fix',
   202 'def', 'obtain' etc. or via the explicit 'write' command, which is
   203 similar to the 'notation' command in theory specifications.
   204 
   205 * Discontinued unnamed infix syntax (legacy feature for many years) --
   206 need to specify constant name and syntax separately.  Internal ML
   207 datatype constructors have been renamed from InfixName to Infix etc.
   208 Minor INCOMPATIBILITY.
   209 
   210 * Schematic theorem statements need to be explicitly markup as such,
   211 via commands 'schematic_lemma', 'schematic_theorem',
   212 'schematic_corollary'.  Thus the relevance of the proof is made
   213 syntactically clear, which impacts performance in a parallel or
   214 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   215 
   216 * Use of cumulative prems via "!" in some proof methods has been
   217 discontinued (old legacy feature).
   218 
   219 * References 'trace_simp' and 'debug_simp' have been replaced by
   220 configuration options stored in the context. Enabling tracing (the
   221 case of debugging is similar) in proofs works via
   222 
   223   using [[trace_simp = true]]
   224 
   225 Tracing is then active for all invocations of the simplifier in
   226 subsequent goal refinement steps. Tracing may also still be enabled or
   227 disabled via the ProofGeneral settings menu.
   228 
   229 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   230 'hide_fact' replace the former 'hide' KIND command.  Minor
   231 INCOMPATIBILITY.
   232 
   233 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   234 more efficient than combinations with -q1 or -q2.
   235 
   236 
   237 *** Pure ***
   238 
   239 * Proofterms record type-class reasoning explicitly, using the
   240 "unconstrain" operation internally.  This eliminates all sort
   241 constraints from a theorem and proof, introducing explicit
   242 OFCLASS-premises.  On the proof term level, this operation is
   243 automatically applied at theorem boundaries, such that closed proofs
   244 are always free of sort constraints.  INCOMPATIBILITY for tools that
   245 inspect proof terms.
   246 
   247 * Local theory specifications may depend on extra type variables that
   248 are not present in the result type -- arguments TYPE('a) :: 'a itself
   249 are added internally.  For example:
   250 
   251   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   252 
   253 * Predicates of locales introduced by classes carry a mandatory
   254 "class" prefix.  INCOMPATIBILITY.
   255 
   256 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   257 
   258 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   259 'class' instead.
   260 
   261 * Command 'code_reflect' allows to incorporate generated ML code into
   262 runtime environment; replaces immature code_datatype antiquotation.
   263 INCOMPATIBILITY.
   264 
   265 * Code generator: simple concept for abstract datatypes obeying
   266 invariants.
   267 
   268 * Code generator: details of internal data cache have no impact on the
   269 user space functionality any longer.
   270 
   271 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   272 subgoals.  This is more appropriate for interpretations with 'where'.
   273 INCOMPATIBILITY.
   274 
   275 * Command 'example_proof' opens an empty proof body.  This allows to
   276 experiment with Isar, without producing any persistent result.
   277 
   278 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   279 within a local theory context, with explicit checking of the
   280 constructors involved (in contrast to the raw 'syntax' versions).
   281 
   282 * Commands 'types' and 'typedecl' now work within a local theory
   283 context -- without introducing dependencies on parameters or
   284 assumptions, which is not possible in Isabelle/Pure.
   285 
   286 * Command 'defaultsort' has been renamed to 'default_sort', it works
   287 within a local theory context.  Minor INCOMPATIBILITY.
   288 
   289 
   290 *** HOL ***
   291 
   292 * Command 'typedef' now works within a local theory context -- without
   293 introducing dependencies on parameters or assumptions, which is not
   294 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   295 contain multiple interpretations of local typedefs (with different
   296 non-emptiness proofs), even in a global theory context.
   297 
   298 * New package for quotient types.  Commands 'quotient_type' and
   299 'quotient_definition' may be used for defining types and constants by
   300 quotient constructions.  An example is the type of integers created by
   301 quotienting pairs of natural numbers:
   302 
   303   fun
   304     intrel :: "(nat * nat) => (nat * nat) => bool"
   305   where
   306     "intrel (x, y) (u, v) = (x + v = u + y)"
   307 
   308   quotient_type int = "nat * nat" / intrel
   309     by (auto simp add: equivp_def expand_fun_eq)
   310 
   311   quotient_definition
   312     "0::int" is "(0::nat, 0::nat)"
   313 
   314 The method "lifting" can be used to lift of theorems from the
   315 underlying "raw" type to the quotient type.  The example
   316 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   317 construction and provides a reasoning infrastructure for finite sets.
   318 
   319 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   320 clash with new theory Quotient in Main HOL.
   321 
   322 * Moved the SMT binding into the main HOL session, eliminating
   323 separate HOL-SMT session.
   324 
   325 * List membership infix mem operation is only an input abbreviation.
   326 INCOMPATIBILITY.
   327 
   328 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   329 for future developements; former Library/Word.thy is still present in
   330 the AFP entry RSAPPS.
   331 
   332 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   333 longer shadowed.  INCOMPATIBILITY.
   334 
   335 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   336 INCOMPATIBILITY.
   337 
   338 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   339 INCOMPATIBILITY.
   340 
   341 * Dropped normalizing_semiring etc; use the facts in semiring classes
   342 instead.  INCOMPATIBILITY.
   343 
   344 * Dropped several real-specific versions of lemmas about floor and
   345 ceiling; use the generic lemmas from theory "Archimedean_Field"
   346 instead.  INCOMPATIBILITY.
   347 
   348   floor_number_of_eq         ~> floor_number_of
   349   le_floor_eq_number_of      ~> number_of_le_floor
   350   le_floor_eq_zero           ~> zero_le_floor
   351   le_floor_eq_one            ~> one_le_floor
   352   floor_less_eq_number_of    ~> floor_less_number_of
   353   floor_less_eq_zero         ~> floor_less_zero
   354   floor_less_eq_one          ~> floor_less_one
   355   less_floor_eq_number_of    ~> number_of_less_floor
   356   less_floor_eq_zero         ~> zero_less_floor
   357   less_floor_eq_one          ~> one_less_floor
   358   floor_le_eq_number_of      ~> floor_le_number_of
   359   floor_le_eq_zero           ~> floor_le_zero
   360   floor_le_eq_one            ~> floor_le_one
   361   floor_subtract_number_of   ~> floor_diff_number_of
   362   floor_subtract_one         ~> floor_diff_one
   363   ceiling_number_of_eq       ~> ceiling_number_of
   364   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   365   ceiling_le_zero_eq         ~> ceiling_le_zero
   366   ceiling_le_eq_one          ~> ceiling_le_one
   367   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   368   less_ceiling_eq_zero       ~> zero_less_ceiling
   369   less_ceiling_eq_one        ~> one_less_ceiling
   370   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   371   ceiling_less_eq_zero       ~> ceiling_less_zero
   372   ceiling_less_eq_one        ~> ceiling_less_one
   373   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   374   le_ceiling_eq_zero         ~> zero_le_ceiling
   375   le_ceiling_eq_one          ~> one_le_ceiling
   376   ceiling_subtract_number_of ~> ceiling_diff_number_of
   377   ceiling_subtract_one       ~> ceiling_diff_one
   378 
   379 * Theory "Finite_Set": various folding_XXX locales facilitate the
   380 application of the various fold combinators on finite sets.
   381 
   382 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   383 provides abstract red-black tree type which is backed by "RBT_Impl" as
   384 implementation.  INCOMPATIBILTY.
   385 
   386 * Theory Library/Coinductive_List has been removed -- superseded by
   387 AFP/thys/Coinductive.
   388 
   389 * Theory PReal, including the type "preal" and related operations, has
   390 been removed.  INCOMPATIBILITY.
   391 
   392 * Real: new development using Cauchy Sequences.
   393 
   394 * Split off theory "Big_Operators" containing setsum, setprod,
   395 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   396 
   397 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   398 "Int" etc.  INCOMPATIBILITY.
   399 
   400 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   401 
   402 * New set of rules "ac_simps" provides combined assoc / commute
   403 rewrites for all interpretations of the appropriate generic locales.
   404 
   405 * Renamed theory "OrderedGroup" to "Groups" and split theory
   406 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   407 appropriate and more consistent names suitable for name prefixes
   408 within the HOL theories.  INCOMPATIBILITY.
   409 
   410 * Some generic constants have been put to appropriate theories:
   411   - less_eq, less: Orderings
   412   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   413   - inverse, divide: Rings
   414 INCOMPATIBILITY.
   415 
   416 * More consistent naming of type classes involving orderings (and
   417 lattices):
   418 
   419     lower_semilattice                   ~> semilattice_inf
   420     upper_semilattice                   ~> semilattice_sup
   421 
   422     dense_linear_order                  ~> dense_linorder
   423 
   424     pordered_ab_group_add               ~> ordered_ab_group_add
   425     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   426     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   427     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   428     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   429     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   430     pordered_cancel_semiring            ~> ordered_cancel_semiring
   431     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   432     pordered_comm_ring                  ~> ordered_comm_ring
   433     pordered_comm_semiring              ~> ordered_comm_semiring
   434     pordered_ring                       ~> ordered_ring
   435     pordered_ring_abs                   ~> ordered_ring_abs
   436     pordered_semiring                   ~> ordered_semiring
   437 
   438     ordered_ab_group_add                ~> linordered_ab_group_add
   439     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   440     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   441     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   442     ordered_field                       ~> linordered_field
   443     ordered_field_no_lb                 ~> linordered_field_no_lb
   444     ordered_field_no_ub                 ~> linordered_field_no_ub
   445     ordered_field_dense_linear_order    ~> dense_linordered_field
   446     ordered_idom                        ~> linordered_idom
   447     ordered_ring                        ~> linordered_ring
   448     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   449     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   450     ordered_ring_strict                 ~> linordered_ring_strict
   451     ordered_semidom                     ~> linordered_semidom
   452     ordered_semiring                    ~> linordered_semiring
   453     ordered_semiring_1                  ~> linordered_semiring_1
   454     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   455     ordered_semiring_strict             ~> linordered_semiring_strict
   456 
   457   The following slightly odd type classes have been moved to a
   458   separate theory Library/Lattice_Algebras:
   459 
   460     lordered_ab_group_add               ~> lattice_ab_group_add
   461     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   462     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   463     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   464     lordered_ring                       ~> lattice_ring
   465 
   466 INCOMPATIBILITY.
   467 
   468 * Refined field classes:
   469   - classes division_ring_inverse_zero, field_inverse_zero,
   470     linordered_field_inverse_zero include rule inverse 0 = 0 --
   471     subsumes former division_by_zero class;
   472   - numerous lemmas have been ported from field to division_ring.
   473 INCOMPATIBILITY.
   474 
   475 * Refined algebra theorem collections:
   476   - dropped theorem group group_simps, use algebra_simps instead;
   477   - dropped theorem group ring_simps, use field_simps instead;
   478   - proper theorem collection field_simps subsumes former theorem
   479     groups field_eq_simps and field_simps;
   480   - dropped lemma eq_minus_self_iff which is a duplicate for
   481     equal_neg_zero.
   482 INCOMPATIBILITY.
   483 
   484 * Theory Finite_Set and List: some lemmas have been generalized from
   485 sets to lattices:
   486 
   487   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   488   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   489   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   490   union_Union_fold_union        ~> sup_Sup_fold_sup
   491   Inter_fold_inter              ~> Inf_fold_inf
   492   Union_fold_union              ~> Sup_fold_sup
   493   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   494   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   495   INTER_fold_inter              ~> INFI_fold_inf
   496   UNION_fold_union              ~> SUPR_fold_sup
   497 
   498 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   499 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   500 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   501 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   502 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   503 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   504 
   505 * Reorganized theory Multiset: swapped notation of pointwise and
   506 multiset order:
   507 
   508   - pointwise ordering is instance of class order with standard syntax
   509     <= and <;
   510   - multiset ordering has syntax <=# and <#; partial order properties
   511     are provided by means of interpretation with prefix
   512     multiset_order;
   513   - less duplication, less historical organization of sections,
   514     conversion from associations lists to multisets, rudimentary code
   515     generation;
   516   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   517     if needed.
   518 
   519 Renamed:
   520 
   521   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   522   multi_count_ext  ~>  multiset_ext
   523   diff_union_inverse2  ~>  diff_union_cancelR
   524 
   525 INCOMPATIBILITY.
   526 
   527 * Theory Permutation: replaced local "remove" by List.remove1.
   528 
   529 * Code generation: ML and OCaml code is decorated with signatures.
   530 
   531 * Theory List: added transpose.
   532 
   533 * Library/Nat_Bijection.thy is a collection of bijective functions
   534 between nat and other types, which supersedes the older libraries
   535 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   536 
   537   Constants:
   538   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   539   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   540   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   541   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   542   Countable.pair_encode           ~> prod_encode
   543   NatIso.prod2nat                 ~> prod_encode
   544   NatIso.nat2prod                 ~> prod_decode
   545   NatIso.sum2nat                  ~> sum_encode
   546   NatIso.nat2sum                  ~> sum_decode
   547   NatIso.list2nat                 ~> list_encode
   548   NatIso.nat2list                 ~> list_decode
   549   NatIso.set2nat                  ~> set_encode
   550   NatIso.nat2set                  ~> set_decode
   551 
   552   Lemmas:
   553   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   554   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   555   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   556   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   557   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   558   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   559   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   560   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   561   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   562   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   563   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   564   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   565   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   566 
   567 * Sledgehammer:
   568   - Renamed ATP commands:
   569     atp_info     ~> sledgehammer running_atps
   570     atp_kill     ~> sledgehammer kill_atps
   571     atp_messages ~> sledgehammer messages
   572     atp_minimize ~> sledgehammer minimize
   573     print_atps   ~> sledgehammer available_atps
   574     INCOMPATIBILITY.
   575   - Added user's manual ("isabelle doc sledgehammer").
   576   - Added option syntax and "sledgehammer_params" to customize
   577     Sledgehammer's behavior.  See the manual for details.
   578   - Modified the Isar proof reconstruction code so that it produces
   579     direct proofs rather than proofs by contradiction.  (This feature
   580     is still experimental.)
   581   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   582     full-typed mode.
   583   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   584 
   585 * Nitpick:
   586   - Added and implemented "binary_ints" and "bits" options.
   587   - Added "std" option and implemented support for nonstandard models.
   588   - Added and implemented "finitize" option to improve the precision
   589     of infinite datatypes based on a monotonicity analysis.
   590   - Added support for quotient types.
   591   - Added support for "specification" and "ax_specification"
   592     constructs.
   593   - Added support for local definitions (for "function" and
   594     "termination" proofs).
   595   - Added support for term postprocessors.
   596   - Optimized "Multiset.multiset" and "FinFun.finfun".
   597   - Improved efficiency of "destroy_constrs" optimization.
   598   - Fixed soundness bugs related to "destroy_constrs" optimization and
   599     record getters.
   600   - Fixed soundness bug related to higher-order constructors.
   601   - Fixed soundness bug when "full_descrs" is enabled.
   602   - Improved precision of set constructs.
   603   - Added "atoms" option.
   604   - Added cache to speed up repeated Kodkod invocations on the same
   605     problems.
   606   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   607     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   608     "SAT4J_Light".  INCOMPATIBILITY.
   609   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   610     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   611   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   612 
   613 * Method "induct" now takes instantiations of the form t, where t is not
   614   a variable, as a shorthand for "x == t", where x is a fresh variable.
   615   If this is not intended, t has to be enclosed in parentheses.
   616   By default, the equalities generated by definitional instantiations
   617   are pre-simplified, which may cause parameters of inductive cases
   618   to disappear, or may even delete some of the inductive cases.
   619   Use "induct (no_simp)" instead of "induct" to restore the old
   620   behaviour. The (no_simp) option is also understood by the "cases"
   621   and "nominal_induct" methods, which now perform pre-simplification, too.
   622   INCOMPATIBILITY.
   623 
   624 
   625 *** HOLCF ***
   626 
   627 * Variable names in lemmas generated by the domain package have
   628 changed; the naming scheme is now consistent with the HOL datatype
   629 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   630 
   631 * The domain package no longer defines the function "foo_copy" for
   632 recursive domain "foo".  The reach lemma is now stated directly in
   633 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   634 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   635 
   636 * Most definedness lemmas generated by the domain package (previously
   637 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   638 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   639 Proofs that used definedness lemmas as intro rules may break,
   640 potential INCOMPATIBILITY.
   641 
   642 * Induction and casedist rules generated by the domain package now
   643 declare proper case_names (one called "bottom", and one named for each
   644 constructor).  INCOMPATIBILITY.
   645 
   646 * For mutually-recursive domains, separate "reach" and "take_lemma"
   647 rules are generated for each domain, INCOMPATIBILITY.
   648 
   649   foo_bar.reach       ~> foo.reach  bar.reach
   650   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   651 
   652 * Some lemmas generated by the domain package have been renamed for
   653 consistency with the datatype package, INCOMPATIBILITY.
   654 
   655   foo.ind        ~> foo.induct
   656   foo.finite_ind ~> foo.finite_induct
   657   foo.coind      ~> foo.coinduct
   658   foo.casedist   ~> foo.exhaust
   659   foo.exhaust    ~> foo.nchotomy
   660 
   661 * For consistency with other definition packages, the fixrec package
   662 now generates qualified theorem names, INCOMPATIBILITY.
   663 
   664   foo_simps  ~> foo.simps
   665   foo_unfold ~> foo.unfold
   666   foo_induct ~> foo.induct
   667 
   668 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   669 method and internal fixrec proofs now use the default simpset instead.
   670 INCOMPATIBILITY.
   671 
   672 * The "contlub" predicate has been removed.  Proof scripts should use
   673 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   674 
   675 * The "admw" predicate has been removed, INCOMPATIBILITY.
   676 
   677 * The constants cpair, cfst, and csnd have been removed in favor of
   678 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   679 
   680 
   681 *** ML ***
   682 
   683 * Antiquotations for basic formal entities:
   684 
   685     @{class NAME}         -- type class
   686     @{class_syntax NAME}  -- syntax representation of the above
   687 
   688     @{type_name NAME}     -- logical type
   689     @{type_abbrev NAME}   -- type abbreviation
   690     @{nonterminal NAME}   -- type of concrete syntactic category
   691     @{type_syntax NAME}   -- syntax representation of any of the above
   692 
   693     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   694     @{const_abbrev NAME}  -- abbreviated constant
   695     @{const_syntax NAME}  -- syntax representation of any of the above
   696 
   697 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   698 syntax constant (cf. 'syntax' command).
   699 
   700 * Antiquotation @{make_string} inlines a function to print arbitrary
   701 values similar to the ML toplevel.  The result is compiler dependent
   702 and may fall back on "?" in certain situations.
   703 
   704 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   705 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   706 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   707 not work with the asynchronous Isar document model.
   708 
   709 * Configuration options now admit dynamic default values, depending on
   710 the context or even global references.
   711 
   712 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   713 uses an efficient external library if available (for Poly/ML).
   714 
   715 * Renamed some important ML structures, while keeping the old names
   716 for some time as aliases within the structure Legacy:
   717 
   718   OuterKeyword  ~>  Keyword
   719   OuterLex      ~>  Token
   720   OuterParse    ~>  Parse
   721   OuterSyntax   ~>  Outer_Syntax
   722   PrintMode     ~>  Print_Mode
   723   SpecParse     ~>  Parse_Spec
   724   ThyInfo       ~>  Thy_Info
   725   ThyLoad       ~>  Thy_Load
   726   ThyOutput     ~>  Thy_Output
   727   TypeInfer     ~>  Type_Infer
   728 
   729 Note that "open Legacy" simplifies porting of sources, but forgetting
   730 to remove it again will complicate porting again in the future.
   731 
   732 * Most operations that refer to a global context are named
   733 accordingly, e.g. Simplifier.global_context or
   734 ProofContext.init_global.  There are some situations where a global
   735 context actually works, but under normal circumstances one needs to
   736 pass the proper local context through the code!
   737 
   738 * Discontinued old TheoryDataFun with its copy/init operation -- data
   739 needs to be pure.  Functor Theory_Data_PP retains the traditional
   740 Pretty.pp argument to merge, which is absent in the standard
   741 Theory_Data version.
   742 
   743 * Sorts.certify_sort and derived "cert" operations for types and terms
   744 no longer minimize sorts.  Thus certification at the boundary of the
   745 inference kernel becomes invariant under addition of class relations,
   746 which is an important monotonicity principle.  Sorts are now minimized
   747 in the syntax layer only, at the boundary between the end-user and the
   748 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   749 explicitly in rare situations.
   750 
   751 * Renamed old-style Drule.standard to Drule.export_without_context, to
   752 emphasize that this is in no way a standard operation.
   753 INCOMPATIBILITY.
   754 
   755 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   756 usual for resolution.  Rare INCOMPATIBILITY.
   757 
   758 * Renamed varify/unvarify operations to varify_global/unvarify_global
   759 to emphasize that these only work in a global situation (which is
   760 quite rare).
   761 
   762 * Curried take and drop in library.ML; negative length is interpreted
   763 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   764 
   765 * Proof terms: type substitutions on proof constants now use canonical
   766 order of type variables.  INCOMPATIBILITY for tools working with proof
   767 terms.
   768 
   769 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   770 may no longer carry premises.  User-level specifications are
   771 transformed accordingly by Thm.add_axiom/add_def.
   772 
   773 
   774 *** System ***
   775 
   776 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   777 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   778 proof terms are enabled unconditionally in the new HOL-Proofs image.
   779 
   780 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   781 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   782 respectively.
   783 
   784 * Old lib/scripts/polyml-platform is superseded by the
   785 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   786 variant, even on a 64 bit machine.  The following example setting
   787 prefers 64 bit if available:
   788 
   789   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   790 
   791 * The preliminary Isabelle/jEdit application demonstrates the emerging
   792 Isabelle/Scala layer for advanced prover interaction and integration.
   793 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   794 component.
   795 
   796 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   797 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   798 similar to the default assignment of the document preparation system
   799 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   800 provides some operations for direct access to the font without asking
   801 the user for manual installation.
   802 
   803 
   804 
   805 New in Isabelle2009-1 (December 2009)
   806 -------------------------------------
   807 
   808 *** General ***
   809 
   810 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   811 one backslash should be used, even in ML sources.
   812 
   813 
   814 *** Pure ***
   815 
   816 * Locale interpretation propagates mixins along the locale hierarchy.
   817 The currently only available mixins are the equations used to map
   818 local definitions to terms of the target domain of an interpretation.
   819 
   820 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   821 loc" to print all interpretations of locale "loc" in the theory.
   822 Interpretations in proofs are not shown.
   823 
   824 * Thoroughly revised locales tutorial.  New section on conditional
   825 interpretation.
   826 
   827 * On instantiation of classes, remaining undefined class parameters
   828 are formally declared.  INCOMPATIBILITY.
   829 
   830 
   831 *** Document preparation ***
   832 
   833 * New generalized style concept for printing terms: @{foo (style) ...}
   834 instead of @{foo_style style ...}  (old form is still retained for
   835 backward compatibility).  Styles can be also applied for
   836 antiquotations prop, term_type and typeof.
   837 
   838 
   839 *** HOL ***
   840 
   841 * New proof method "smt" for a combination of first-order logic with
   842 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   843 fixed-size bitvectors; there is also basic support for higher-order
   844 features (esp. lambda abstractions).  It is an incomplete decision
   845 procedure based on external SMT solvers using the oracle mechanism;
   846 for the SMT solver Z3, this method is proof-producing.  Certificates
   847 are provided to avoid calling the external solvers solely for
   848 re-checking proofs.  Due to a remote SMT service there is no need for
   849 installing SMT solvers locally.  See src/HOL/SMT.
   850 
   851 * New commands to load and prove verification conditions generated by
   852 the Boogie program verifier or derived systems (e.g. the Verifying C
   853 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   854 
   855 * New counterexample generator tool 'nitpick' based on the Kodkod
   856 relational model finder.  See src/HOL/Tools/Nitpick and
   857 src/HOL/Nitpick_Examples.
   858 
   859 * New commands 'code_pred' and 'values' to invoke the predicate
   860 compiler and to enumerate values of inductive predicates.
   861 
   862 * A tabled implementation of the reflexive transitive closure.
   863 
   864 * New implementation of quickcheck uses generic code generator;
   865 default generators are provided for all suitable HOL types, records
   866 and datatypes.  Old quickcheck can be re-activated importing theory
   867 Library/SML_Quickcheck.
   868 
   869 * New testing tool Mirabelle for automated proof tools.  Applies
   870 several tools and tactics like sledgehammer, metis, or quickcheck, to
   871 every proof step in a theory.  To be used in batch mode via the
   872 "mirabelle" utility.
   873 
   874 * New proof method "sos" (sum of squares) for nonlinear real
   875 arithmetic (originally due to John Harison). It requires theory
   876 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   877 works well in practice on quantifier-free real arithmetic with +, -,
   878 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   879 inequalities between polynomials.  It makes use of external
   880 semidefinite programming solvers.  Method "sos" generates a
   881 certificate that can be pasted into the proof thus avoiding the need
   882 to call an external tool every time the proof is checked.  See
   883 src/HOL/Library/Sum_Of_Squares.
   884 
   885 * New method "linarith" invokes existing linear arithmetic decision
   886 procedure only.
   887 
   888 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   889 
   890 * New Sledgehammer option "Full Types" in Proof General settings menu.
   891 Causes full type information to be output to the ATPs.  This slows
   892 ATPs down considerably but eliminates a source of unsound "proofs"
   893 that fail later.
   894 
   895 * New method "metisFT": A version of metis that uses full type
   896 information in order to avoid failures of proof reconstruction.
   897 
   898 * New evaluator "approximate" approximates an real valued term using
   899 the same method as the approximation method.
   900 
   901 * Method "approximate" now supports arithmetic expressions as
   902 boundaries of intervals and implements interval splitting and Taylor
   903 series expansion.
   904 
   905 * ML antiquotation @{code_datatype} inserts definition of a datatype
   906 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   907 
   908 * New theory SupInf of the supremum and infimum operators for sets of
   909 reals.
   910 
   911 * New theory Probability, which contains a development of measure
   912 theory, eventually leading to Lebesgue integration and probability.
   913 
   914 * Extended Multivariate Analysis to include derivation and Brouwer's
   915 fixpoint theorem.
   916 
   917 * Reorganization of number theory, INCOMPATIBILITY:
   918   - new number theory development for nat and int, in theories Divides
   919     and GCD as well as in new session Number_Theory
   920   - some constants and facts now suffixed with _nat and _int
   921     accordingly
   922   - former session NumberTheory now named Old_Number_Theory, including
   923     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   924   - moved theory Pocklington from src/HOL/Library to
   925     src/HOL/Old_Number_Theory
   926 
   927 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   928 lcm of finite and infinite sets. It is shown that they form a complete
   929 lattice.
   930 
   931 * Class semiring_div requires superclass no_zero_divisors and proof of
   932 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   933 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   934 generalized to class semiring_div, subsuming former theorems
   935 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   936 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   937 INCOMPATIBILITY.
   938 
   939 * Refinements to lattice classes and sets:
   940   - less default intro/elim rules in locale variant, more default
   941     intro/elim rules in class variant: more uniformity
   942   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   943     le_inf_iff
   944   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   945     sup_aci)
   946   - renamed ACI to inf_sup_aci
   947   - new class "boolean_algebra"
   948   - class "complete_lattice" moved to separate theory
   949     "Complete_Lattice"; corresponding constants (and abbreviations)
   950     renamed and with authentic syntax:
   951     Set.Inf ~>    Complete_Lattice.Inf
   952     Set.Sup ~>    Complete_Lattice.Sup
   953     Set.INFI ~>   Complete_Lattice.INFI
   954     Set.SUPR ~>   Complete_Lattice.SUPR
   955     Set.Inter ~>  Complete_Lattice.Inter
   956     Set.Union ~>  Complete_Lattice.Union
   957     Set.INTER ~>  Complete_Lattice.INTER
   958     Set.UNION ~>  Complete_Lattice.UNION
   959   - authentic syntax for
   960     Set.Pow
   961     Set.image
   962   - mere abbreviations:
   963     Set.empty               (for bot)
   964     Set.UNIV                (for top)
   965     Set.inter               (for inf, formerly Set.Int)
   966     Set.union               (for sup, formerly Set.Un)
   967     Complete_Lattice.Inter  (for Inf)
   968     Complete_Lattice.Union  (for Sup)
   969     Complete_Lattice.INTER  (for INFI)
   970     Complete_Lattice.UNION  (for SUPR)
   971   - object-logic definitions as far as appropriate
   972 
   973 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   974 Un_subset_iff are explicitly deleted as default simp rules; then also
   975 their lattice counterparts le_inf_iff and le_sup_iff have to be
   976 deleted to achieve the desired effect.
   977 
   978 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   979 rules by default any longer; the same applies to min_max.inf_absorb1
   980 etc.  INCOMPATIBILITY.
   981 
   982 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   983 pred_set_conv by default.  INCOMPATIBILITY.
   984 
   985 * Power operations on relations and functions are now one dedicated
   986 constant "compow" with infix syntax "^^".  Power operation on
   987 multiplicative monoids retains syntax "^" and is now defined generic
   988 in class power.  INCOMPATIBILITY.
   989 
   990 * Relation composition "R O S" now has a more standard argument order:
   991 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   992 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   993 break, since the O_assoc rule was not rewritten like this.  Fix using
   994 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   995 
   996 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   997 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   998 INCOMPATIBILITY.
   999 
  1000 * Most rules produced by inductive and datatype package have mandatory
  1001 prefixes.  INCOMPATIBILITY.
  1002 
  1003 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1004 the attribute of the same name.  Each of the theorems in the list
  1005 DERIV_intros assumes composition with an additional function and
  1006 matches a variable to the derivative, which has to be solved by the
  1007 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1008 of most elementary terms.  Former Maclauren.DERIV_tac and
  1009 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1010 INCOMPATIBILITY.
  1011 
  1012 * Code generator attributes follow the usual underscore convention:
  1013     code_unfold     replaces    code unfold
  1014     code_post       replaces    code post
  1015     etc.
  1016   INCOMPATIBILITY.
  1017 
  1018 * Renamed methods:
  1019     sizechange -> size_change
  1020     induct_scheme -> induction_schema
  1021   INCOMPATIBILITY.
  1022 
  1023 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1024 INCOMPATIBILITY, use "undefined" directly.
  1025 
  1026 * Renamed theorems:
  1027     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1028     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1029     Suc_plus1 -> Suc_eq_plus1
  1030     *anti_sym -> *antisym*
  1031     vector_less_eq_def -> vector_le_def
  1032   INCOMPATIBILITY.
  1033 
  1034 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1035 INCOMPATIBILITY.
  1036 
  1037 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1038 INCOMPATIBILITY.
  1039 
  1040 
  1041 *** HOLCF ***
  1042 
  1043 * Theory Representable defines a class "rep" of domains that are
  1044 representable (via an ep-pair) in the universal domain type "udom".
  1045 Instances are provided for all type constructors defined in HOLCF.
  1046 
  1047 * The 'new_domain' command is a purely definitional version of the
  1048 domain package, for representable domains.  Syntax is identical to the
  1049 old domain package.  The 'new_domain' package also supports indirect
  1050 recursion using previously-defined type constructors.  See
  1051 src/HOLCF/ex/New_Domain.thy for examples.
  1052 
  1053 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1054 on the left-hand side of an equation, and then performs
  1055 simplification.  Rewriting is done using rules declared with the
  1056 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1057 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1058 
  1059 * The pattern-match compiler in 'fixrec' can now handle constructors
  1060 with HOL function types.  Pattern-match combinators for the Pair
  1061 constructor are pre-configured.
  1062 
  1063 * The 'fixrec' package now produces better fixed-point induction rules
  1064 for mutually-recursive definitions:  Induction rules have conclusions
  1065 of the form "P foo bar" instead of "P <foo, bar>".
  1066 
  1067 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1068 been renamed to "below".  The name "below" now replaces "less" in many
  1069 theorem names.  (Legacy theorem names using "less" are still supported
  1070 as well.)
  1071 
  1072 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1073 patterns can be used to generate strictness rules, or to make
  1074 functions more strict (much like the bang-patterns supported by the
  1075 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1076 examples.
  1077 
  1078 
  1079 *** ML ***
  1080 
  1081 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1082 errors and run-time exceptions, including detailed source positions.
  1083 
  1084 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1085 identified entries, with some additional information such as source
  1086 position, logical grouping etc.
  1087 
  1088 * Theory and context data is now introduced by the simplified and
  1089 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1090 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1091 copy operation) is still available for some time.
  1092 
  1093 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1094 provides a high-level programming interface to synchronized state
  1095 variables with atomic update.  This works via pure function
  1096 application within a critical section -- its runtime should be as
  1097 short as possible; beware of deadlocks if critical code is nested,
  1098 either directly or indirectly via other synchronized variables!
  1099 
  1100 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1101 wraps raw ML references, explicitly indicating their non-thread-safe
  1102 behaviour.  The Isar toplevel keeps this structure open, to
  1103 accommodate Proof General as well as quick and dirty interactive
  1104 experiments with references.
  1105 
  1106 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1107 parallel tactical reasoning.
  1108 
  1109 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1110 are similar to SUBPROOF, but are slightly more flexible: only the
  1111 specified parts of the subgoal are imported into the context, and the
  1112 body tactic may introduce new subgoals and schematic variables.
  1113 
  1114 * Old tactical METAHYPS, which does not observe the proof context, has
  1115 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1116 or Subgoal.FOCUS etc.
  1117 
  1118 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1119 functors have their own ML name space there is no point to mark them
  1120 separately.)  Minor INCOMPATIBILITY.
  1121 
  1122 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1123 
  1124 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1125 INCOMPATIBILITY.
  1126 
  1127 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1128 mode, which avoids critical setmp.
  1129 
  1130 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1131 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1132 Attrib/Method.setup introduced in Isabelle2009.
  1133 
  1134 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1135 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1136 last resort.  INCOMPATIBILITY.
  1137 
  1138 * Display.pretty_thm now requires a proper context (cf. former
  1139 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1140 or even Display.pretty_thm_without_context as last resort.
  1141 INCOMPATIBILITY.
  1142 
  1143 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1144 Syntax.pretty_typ/term directly, preferably with proper context
  1145 instead of global theory.
  1146 
  1147 
  1148 *** System ***
  1149 
  1150 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1151 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1152 usedir option -q.
  1153 
  1154 * Support for additional "Isabelle components" via etc/components, see
  1155 also the system manual.
  1156 
  1157 * The isabelle makeall tool now operates on all components with
  1158 IsaMakefile, not just hardwired "logics".
  1159 
  1160 * Removed "compress" option from isabelle-process and isabelle usedir;
  1161 this is always enabled.
  1162 
  1163 * Discontinued support for Poly/ML 4.x versions.
  1164 
  1165 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1166 on a given logic image.  This requires the lighttpd webserver and is
  1167 currently supported on Linux only.
  1168 
  1169 
  1170 
  1171 New in Isabelle2009 (April 2009)
  1172 --------------------------------
  1173 
  1174 *** General ***
  1175 
  1176 * Simplified main Isabelle executables, with less surprises on
  1177 case-insensitive file-systems (such as Mac OS).
  1178 
  1179   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1180     "isatool."
  1181 
  1182   - The former "isabelle" alias for "isabelle-process" has been
  1183     removed (should rarely occur to regular users).
  1184 
  1185   - The former "isabelle-interface" and its alias "Isabelle" have been
  1186     removed (interfaces are now regular Isabelle tools).
  1187 
  1188 Within scripts and make files, the Isabelle environment variables
  1189 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1190 respectively.  (The latter are still available as legacy feature.)
  1191 
  1192 The old isabelle-interface wrapper could react in confusing ways if
  1193 the interface was uninstalled or changed otherwise.  Individual
  1194 interface tool configuration is now more explicit, see also the
  1195 Isabelle system manual.  In particular, Proof General is now available
  1196 via "isabelle emacs".
  1197 
  1198 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1199 purge installed copies of Isabelle executables and re-run "isabelle
  1200 install -p ...", or use symlinks.
  1201 
  1202 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1203 old ~/isabelle, which was slightly non-standard and apt to cause
  1204 surprises on case-insensitive file-systems (such as Mac OS).
  1205 
  1206 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1207 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1208 care is required when using older releases of Isabelle.  Note that
  1209 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1210 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1211 
  1212 * Proofs of fully specified statements are run in parallel on
  1213 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1214 a regular 4-core machine, if the initial heap space is made reasonably
  1215 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1216 
  1217 * The main reference manuals ("isar-ref", "implementation", and
  1218 "system") have been updated and extended.  Formally checked references
  1219 as hyperlinks are now available uniformly.
  1220 
  1221 
  1222 *** Pure ***
  1223 
  1224 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1225 respects.  The most important changes are listed below.  See the
  1226 Tutorial on Locales ("locales" manual) for details.
  1227 
  1228 - In locale expressions, instantiation replaces renaming.  Parameters
  1229 must be declared in a for clause.  To aid compatibility with previous
  1230 parameter inheritance, in locale declarations, parameters that are not
  1231 'touched' (instantiation position "_" or omitted) are implicitly added
  1232 with their syntax at the beginning of the for clause.
  1233 
  1234 - Syntax from abbreviations and definitions in locales is available in
  1235 locale expressions and context elements.  The latter is particularly
  1236 useful in locale declarations.
  1237 
  1238 - More flexible mechanisms to qualify names generated by locale
  1239 expressions.  Qualifiers (prefixes) may be specified in locale
  1240 expressions, and can be marked as mandatory (syntax: "name!:") or
  1241 optional (syntax "name?:").  The default depends for plain "name:"
  1242 depends on the situation where a locale expression is used: in
  1243 commands 'locale' and 'sublocale' prefixes are optional, in
  1244 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1245 implicit qualifiers derived from the parameter names of a locale are
  1246 no longer generated.
  1247 
  1248 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1249 instantiation clause in "interpretation" and "interpret" (square
  1250 brackets) is no longer available.  Use locale expressions.
  1251 
  1252 - When converting proof scripts, mandatory qualifiers in
  1253 'interpretation' and 'interpret' should be retained by default, even
  1254 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1255 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1256 in locale expressions range over a single locale instance only.
  1257 
  1258 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1259 In existing theorem specifications replace the includes element by the
  1260 respective context elements of the included locale, omitting those
  1261 that are already present in the theorem specification.  Multiple
  1262 assume elements of a locale should be replaced by a single one
  1263 involving the locale predicate.  In the proof body, declarations (most
  1264 notably theorems) may be regained by interpreting the respective
  1265 locales in the proof context as required (command "interpret").
  1266 
  1267 If using "includes" in replacement of a target solely because the
  1268 parameter types in the theorem are not as general as in the target,
  1269 consider declaring a new locale with additional type constraints on
  1270 the parameters (context element "constrains").
  1271 
  1272 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1273 
  1274 - Locale interpretation commands no longer attempt to simplify goal.
  1275 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1276 methods intro_locales and unfold_locales to clarify.
  1277 
  1278 - Locale interpretation commands no longer accept interpretation
  1279 attributes.  INCOMPATIBILITY.
  1280 
  1281 * Class declaration: so-called "base sort" must not be given in import
  1282 list any longer, but is inferred from the specification.  Particularly
  1283 in HOL, write
  1284 
  1285     class foo = ...
  1286 
  1287 instead of
  1288 
  1289     class foo = type + ...
  1290 
  1291 * Class target: global versions of theorems stemming do not carry a
  1292 parameter prefix any longer.  INCOMPATIBILITY.
  1293 
  1294 * Class 'instance' command no longer accepts attached definitions.
  1295 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1296 
  1297 * Recovered hiding of consts, which was accidentally broken in
  1298 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1299 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1300 
  1301 * Slightly more coherent Pure syntax, with updated documentation in
  1302 isar-ref manual.  Removed locales meta_term_syntax and
  1303 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1304 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1305 directly in regular applications.
  1306 
  1307 * There is a new syntactic category "float_const" for signed decimal
  1308 fractions (e.g. 123.45 or -123.45).
  1309 
  1310 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1311 interface with 'setup' command instead.
  1312 
  1313 * Command 'local_setup' is similar to 'setup', but operates on a local
  1314 theory context.
  1315 
  1316 * The 'axiomatization' command now only works within a global theory
  1317 context.  INCOMPATIBILITY.
  1318 
  1319 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1320 hypotheses.  Sorts required in the course of reasoning need to be
  1321 covered by the constraints in the initial statement, completed by the
  1322 type instance information of the background theory.  Non-trivial sort
  1323 hypotheses, which rarely occur in practice, may be specified via
  1324 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1325 
  1326   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1327 
  1328 The result contains an implicit sort hypotheses as before --
  1329 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1330 normalization.
  1331 
  1332 * Generalized Isar history, with support for linear undo, direct state
  1333 addressing etc.
  1334 
  1335 * Changed defaults for unify configuration options:
  1336 
  1337   unify_trace_bound = 50 (formerly 25)
  1338   unify_search_bound = 60 (formerly 30)
  1339 
  1340 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1341 
  1342   a) On theory merge, the last set of code equations for a particular
  1343      constant is taken (in accordance with the policy applied by other
  1344      parts of the code generator framework).
  1345 
  1346   b) Code equations stemming from explicit declarations (e.g. code
  1347      attribute) gain priority over default code equations stemming
  1348      from definition, primrec, fun etc.
  1349 
  1350 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1351 
  1352 * Unified theorem tables for both code generators.  Thus [code
  1353 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1354 
  1355 * Command 'find_consts' searches for constants based on type and name
  1356 patterns, e.g.
  1357 
  1358     find_consts "_ => bool"
  1359 
  1360 By default, matching is against subtypes, but it may be restricted to
  1361 the whole type.  Searching by name is possible.  Multiple queries are
  1362 conjunctive and queries may be negated by prefixing them with a
  1363 hyphen:
  1364 
  1365     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1366 
  1367 * New 'find_theorems' criterion "solves" matches theorems that
  1368 directly solve the current goal (modulo higher-order unification).
  1369 
  1370 * Auto solve feature for main theorem statements: whenever a new goal
  1371 is stated, "find_theorems solves" is called; any theorems that could
  1372 solve the lemma directly are listed as part of the goal state.
  1373 Cf. associated options in Proof General Isabelle settings menu,
  1374 enabled by default, with reasonable timeout for pathological cases of
  1375 higher-order unification.
  1376 
  1377 
  1378 *** Document preparation ***
  1379 
  1380 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1381 demanding keyword 'by' and supporting the full method expression
  1382 syntax just like the Isar command 'by'.
  1383 
  1384 
  1385 *** HOL ***
  1386 
  1387 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1388 points Main and Complex_Main remain as before.
  1389 
  1390 * Logic image HOL-Plain provides a minimal HOL with the most important
  1391 tools available (inductive, datatype, primrec, ...).  This facilitates
  1392 experimentation and tool development.  Note that user applications
  1393 (and library theories) should never refer to anything below theory
  1394 Main, as before.
  1395 
  1396 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1397 experimentation due to shorter build times.
  1398 
  1399 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1400 were previously part of former HOL-Complex.  Entry point Hyperreal
  1401 remains valid, but theories formerly using Complex_Main should now use
  1402 new entry point Hypercomplex.
  1403 
  1404 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1405 Posix processes.  Avoids potentially expensive forking of the ML
  1406 process.  New thread-based implementation also works on non-Unix
  1407 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1408 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1409 commands are covered in the isar-ref manual.
  1410 
  1411 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1412 sledgehammer without local ATP installation (Vampire etc.). Other
  1413 provers may be included via suitable ML wrappers, see also
  1414 src/HOL/ATP_Linkup.thy.
  1415 
  1416 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1417 menu.
  1418 
  1419 * The metis method no longer fails because the theorem is too trivial
  1420 (contains the empty clause).
  1421 
  1422 * The metis method now fails in the usual manner, rather than raising
  1423 an exception, if it determines that it cannot prove the theorem.
  1424 
  1425 * Method "coherent" implements a prover for coherent logic (see also
  1426 src/Tools/coherent.ML).
  1427 
  1428 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1429 "undefined" is the right choice to replace "arbitrary", though
  1430 logically there is no difference.  INCOMPATIBILITY.
  1431 
  1432 * Command "value" now integrates different evaluation mechanisms.  The
  1433 result of the first successful evaluation mechanism is printed.  In
  1434 square brackets a particular named evaluation mechanisms may be
  1435 specified (currently, [SML], [code] or [nbe]).  See further
  1436 src/HOL/ex/Eval_Examples.thy.
  1437 
  1438 * Normalization by evaluation now allows non-leftlinear equations.
  1439 Declare with attribute [code nbe].
  1440 
  1441 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1442 as the structured Isar versions "cases" and "induct", cf. the
  1443 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1444 are now presented as a list of individual projections
  1445 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1446 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1447 rare situations a different rule is selected --- notably nested tuple
  1448 elimination instead of former prod.exhaust: use explicit (case_tac t
  1449 rule: prod.exhaust) here.
  1450 
  1451 * Attributes "cases", "induct", "coinduct" support "del" option.
  1452 
  1453 * Removed fact "case_split_thm", which duplicates "case_split".
  1454 
  1455 * The option datatype has been moved to a new theory Option.  Renamed
  1456 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1457 
  1458 * New predicate "strict_mono" classifies strict functions on partial
  1459 orders.  With strict functions on linear orders, reasoning about
  1460 (in)equalities is facilitated by theorems "strict_mono_eq",
  1461 "strict_mono_less_eq" and "strict_mono_less".
  1462 
  1463 * Some set operations are now proper qualified constants with
  1464 authentic syntax.  INCOMPATIBILITY:
  1465 
  1466     op Int ~>   Set.Int
  1467     op Un ~>    Set.Un
  1468     INTER ~>    Set.INTER
  1469     UNION ~>    Set.UNION
  1470     Inter ~>    Set.Inter
  1471     Union ~>    Set.Union
  1472     {} ~>       Set.empty
  1473     UNIV ~>     Set.UNIV
  1474 
  1475 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1476 theory Set.
  1477 
  1478 * Auxiliary class "itself" has disappeared -- classes without any
  1479 parameter are treated as expected by the 'class' command.
  1480 
  1481 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1482 
  1483 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1484 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1485 
  1486 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1487 method "approximation".  It proves formulas on real values by using
  1488 interval arithmetic.  In the formulas are also the transcendental
  1489 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1490 allowed. For examples see
  1491 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1492 
  1493 * Theory "Reflection" now resides in HOL/Library.
  1494 
  1495 * Entry point to Word library now simply named "Word".
  1496 INCOMPATIBILITY.
  1497 
  1498 * Made source layout more coherent with logical distribution
  1499 structure:
  1500 
  1501     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1502     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1503     src/HOL/Library/GCD.thy ~> src/HOL/
  1504     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1505     src/HOL/Library/Parity.thy ~> src/HOL/
  1506     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1507     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1508     src/HOL/Real/Lubs.thy ~> src/HOL/
  1509     src/HOL/Real/PReal.thy ~> src/HOL/
  1510     src/HOL/Real/Rational.thy ~> src/HOL/
  1511     src/HOL/Real/RComplete.thy ~> src/HOL/
  1512     src/HOL/Real/RealDef.thy ~> src/HOL/
  1513     src/HOL/Real/RealPow.thy ~> src/HOL/
  1514     src/HOL/Real/Real.thy ~> src/HOL/
  1515     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1516     src/HOL/Complex/Complex.thy ~> src/HOL/
  1517     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1518     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1519     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1520     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1521     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1522     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1523     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1524     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1525     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1526     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1527     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1528     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1529     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1530     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1531     src/HOL/Real/Float ~> src/HOL/Library/
  1532     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1533     src/HOL/Real/RealVector.thy ~> src/HOL/
  1534 
  1535     src/HOL/arith_data.ML ~> src/HOL/Tools
  1536     src/HOL/hologic.ML ~> src/HOL/Tools
  1537     src/HOL/simpdata.ML ~> src/HOL/Tools
  1538     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1539     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1540     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1541     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1542     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1543     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1544     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1545 
  1546     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1547     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1548     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1549     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1550     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1551     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1552 
  1553 * If methods "eval" and "evaluation" encounter a structured proof
  1554 state with !!/==>, only the conclusion is evaluated to True (if
  1555 possible), avoiding strange error messages.
  1556 
  1557 * Method "sizechange" automates termination proofs using (a
  1558 modification of) the size-change principle.  Requires SAT solver.  See
  1559 src/HOL/ex/Termination.thy for examples.
  1560 
  1561 * Simplifier: simproc for let expressions now unfolds if bound
  1562 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1563 
  1564 * Method "arith": Linear arithmetic now ignores all inequalities when
  1565 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1566 
  1567 * New attribute "arith" for facts that should always be used
  1568 automatically by arithmetic. It is intended to be used locally in
  1569 proofs, e.g.
  1570 
  1571   assumes [arith]: "x > 0"
  1572 
  1573 Global usage is discouraged because of possible performance impact.
  1574 
  1575 * New classes "top" and "bot" with corresponding operations "top" and
  1576 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1577 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1578 
  1579 * Changed definition lemma "less_fun_def" in order to provide an
  1580 instance for preorders on functions; use lemma "less_le" instead.
  1581 INCOMPATIBILITY.
  1582 
  1583 * Theory Orderings: class "wellorder" moved here, with explicit
  1584 induction rule "less_induct" as assumption.  For instantiation of
  1585 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1586 INCOMPATIBILITY.
  1587 
  1588 * Theory Orderings: added class "preorder" as superclass of "order".
  1589 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1590 etc. slightly changed.  Some theorems named order_class.* now named
  1591 preorder_class.*.
  1592 
  1593 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1594 "diag" to "Id_on".
  1595 
  1596 * Theory Finite_Set: added a new fold combinator of type
  1597 
  1598   ('a => 'b => 'b) => 'b => 'a set => 'b
  1599 
  1600 Occasionally this is more convenient than the old fold combinator
  1601 which is now defined in terms of the new one and renamed to
  1602 fold_image.
  1603 
  1604 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1605 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1606 extended with further lemmas!).  At the moment both still exist but
  1607 the former will disappear at some point.
  1608 
  1609 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1610 class recpower.  Type-specific simp rules for various recpower types
  1611 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1612 
  1613 rat_power_0    -> power_0
  1614 rat_power_Suc  -> power_Suc
  1615 realpow_0      -> power_0
  1616 realpow_Suc    -> power_Suc
  1617 complexpow_0   -> power_0
  1618 complexpow_Suc -> power_Suc
  1619 power_poly_0   -> power_0
  1620 power_poly_Suc -> power_Suc
  1621 
  1622 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1623 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1624 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1625 of lemmas from Divides has been generalized from nat to class
  1626 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1627 renames resulting from duplicate elimination:
  1628 
  1629     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1630     zero_dvd_iff ~>         dvd_0_left_iff
  1631     dvd_0 ~>                dvd_0_right
  1632     DIVISION_BY_ZERO_DIV ~> div_by_0
  1633     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1634     mult_div ~>             div_mult_self2_is_id
  1635     mult_mod ~>             mod_mult_self2_is_0
  1636 
  1637 * Theory IntDiv: removed many lemmas that are instances of class-based
  1638 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1639 rename old lemmas as follows:
  1640 
  1641 dvd_diff               -> nat_dvd_diff
  1642 dvd_zminus_iff         -> dvd_minus_iff
  1643 mod_add1_eq            -> mod_add_eq
  1644 mod_mult1_eq           -> mod_mult_right_eq
  1645 mod_mult1_eq'          -> mod_mult_left_eq
  1646 mod_mult_distrib_mod   -> mod_mult_eq
  1647 nat_mod_add_left_eq    -> mod_add_left_eq
  1648 nat_mod_add_right_eq   -> mod_add_right_eq
  1649 nat_mod_div_trivial    -> mod_div_trivial
  1650 nat_mod_mod_trivial    -> mod_mod_trivial
  1651 zdiv_zadd_self1        -> div_add_self1
  1652 zdiv_zadd_self2        -> div_add_self2
  1653 zdiv_zmult_self1       -> div_mult_self2_is_id
  1654 zdiv_zmult_self2       -> div_mult_self1_is_id
  1655 zdvd_triv_left         -> dvd_triv_left
  1656 zdvd_triv_right        -> dvd_triv_right
  1657 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1658 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1659 zmod_zadd_left_eq      -> mod_add_left_eq
  1660 zmod_zadd_right_eq     -> mod_add_right_eq
  1661 zmod_zadd_self1        -> mod_add_self1
  1662 zmod_zadd_self2        -> mod_add_self2
  1663 zmod_zadd1_eq          -> mod_add_eq
  1664 zmod_zdiff1_eq         -> mod_diff_eq
  1665 zmod_zdvd_zmod         -> mod_mod_cancel
  1666 zmod_zmod_cancel       -> mod_mod_cancel
  1667 zmod_zmult_self1       -> mod_mult_self2_is_0
  1668 zmod_zmult_self2       -> mod_mult_self1_is_0
  1669 zmod_1                 -> mod_by_1
  1670 zdiv_1                 -> div_by_1
  1671 zdvd_abs1              -> abs_dvd_iff
  1672 zdvd_abs2              -> dvd_abs_iff
  1673 zdvd_refl              -> dvd_refl
  1674 zdvd_trans             -> dvd_trans
  1675 zdvd_zadd              -> dvd_add
  1676 zdvd_zdiff             -> dvd_diff
  1677 zdvd_zminus_iff        -> dvd_minus_iff
  1678 zdvd_zminus2_iff       -> minus_dvd_iff
  1679 zdvd_zmultD            -> dvd_mult_right
  1680 zdvd_zmultD2           -> dvd_mult_left
  1681 zdvd_zmult_mono        -> mult_dvd_mono
  1682 zdvd_0_right           -> dvd_0_right
  1683 zdvd_0_left            -> dvd_0_left_iff
  1684 zdvd_1_left            -> one_dvd
  1685 zminus_dvd_iff         -> minus_dvd_iff
  1686 
  1687 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1688 
  1689 * The real numbers offer decimal input syntax: 12.34 is translated
  1690 into 1234/10^2. This translation is not reversed upon output.
  1691 
  1692 * Theory Library/Polynomial defines an abstract type 'a poly of
  1693 univariate polynomials with coefficients of type 'a.  In addition to
  1694 the standard ring operations, it also supports div and mod.  Code
  1695 generation is also supported, using list-style constructors.
  1696 
  1697 * Theory Library/Inner_Product defines a class of real_inner for real
  1698 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1699 => real.  Class real_inner is a subclass of real_normed_vector from
  1700 theory RealVector.
  1701 
  1702 * Theory Library/Product_Vector provides instances for the product
  1703 type 'a * 'b of several classes from RealVector and Inner_Product.
  1704 Definitions of addition, subtraction, scalar multiplication, norms,
  1705 and inner products are included.
  1706 
  1707 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1708 addition to the field operations, numerals and case syntax are also
  1709 supported.
  1710 
  1711 * Theory Library/Diagonalize provides constructive version of Cantor's
  1712 first diagonalization argument.
  1713 
  1714 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1715 zlcm (for int); carried together from various gcd/lcm developements in
  1716 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1717 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1718 may recover tupled syntax as follows:
  1719 
  1720     hide (open) const gcd
  1721     abbreviation gcd where
  1722       "gcd == (%(a, b). GCD.gcd a b)"
  1723     notation (output)
  1724       GCD.gcd ("gcd '(_, _')")
  1725 
  1726 The same works for lcm, zgcd, zlcm.
  1727 
  1728 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1729 instantiations for algebraic structures.  Removed some duplicate
  1730 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1731 
  1732 * ML antiquotation @{code} takes a constant as argument and generates
  1733 corresponding code in background and inserts name of the corresponding
  1734 resulting ML value/function/datatype constructor binding in place.
  1735 All occurrences of @{code} with a single ML block are generated
  1736 simultaneously.  Provides a generic and safe interface for
  1737 instrumentalizing code generation.  See
  1738 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1739 In future you ought to refrain from ad-hoc compiling generated SML
  1740 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1741 cannot refer to constants for which user-defined serializations are
  1742 set.  Refer to the corresponding ML counterpart directly in that
  1743 cases.
  1744 
  1745 * Command 'rep_datatype': instead of theorem names the command now
  1746 takes a list of terms denoting the constructors of the type to be
  1747 represented as datatype.  The characteristic theorems have to be
  1748 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1749 have disappeared in favour of existing ones:
  1750 
  1751     unit_induct                 ~> unit.induct
  1752     prod_induct                 ~> prod.induct
  1753     sum_induct                  ~> sum.induct
  1754     Suc_Suc_eq                  ~> nat.inject
  1755     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1756 
  1757 
  1758 *** HOL-Algebra ***
  1759 
  1760 * New locales for orders and lattices where the equivalence relation
  1761 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1762 locales use a record structure with field eq for the equivalence.
  1763 
  1764 * New theory of factorial domains.
  1765 
  1766 * Units_l_inv and Units_r_inv are now simp rules by default.
  1767 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1768 and/or r_inv will now also require deletion of these lemmas.
  1769 
  1770 * Renamed the following theorems, INCOMPATIBILITY:
  1771 
  1772 UpperD ~> Upper_memD
  1773 LowerD ~> Lower_memD
  1774 least_carrier ~> least_closed
  1775 greatest_carrier ~> greatest_closed
  1776 greatest_Lower_above ~> greatest_Lower_below
  1777 one_zero ~> carrier_one_zero
  1778 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1779 
  1780 
  1781 *** HOL-Nominal ***
  1782 
  1783 * Nominal datatypes can now contain type-variables.
  1784 
  1785 * Commands 'nominal_inductive' and 'equivariance' work with local
  1786 theory targets.
  1787 
  1788 * Nominal primrec can now works with local theory targets and its
  1789 specification syntax now conforms to the general format as seen in
  1790 'inductive' etc.
  1791 
  1792 * Method "perm_simp" honours the standard simplifier attributes
  1793 (no_asm), (no_asm_use) etc.
  1794 
  1795 * The new predicate #* is defined like freshness, except that on the
  1796 left hand side can be a set or list of atoms.
  1797 
  1798 * Experimental command 'nominal_inductive2' derives strong induction
  1799 principles for inductive definitions.  In contrast to
  1800 'nominal_inductive', which can only deal with a fixed number of
  1801 binders, it can deal with arbitrary expressions standing for sets of
  1802 atoms to be avoided.  The only inductive definition we have at the
  1803 moment that needs this generalisation is the typing rule for Lets in
  1804 the algorithm W:
  1805 
  1806  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1807  -----------------------------------------------------------------
  1808          Gamma |- Let x be t1 in t2 : T2
  1809 
  1810 In this rule one wants to avoid all the binders that are introduced by
  1811 "close Gamma T1".  We are looking for other examples where this
  1812 feature might be useful.  Please let us know.
  1813 
  1814 
  1815 *** HOLCF ***
  1816 
  1817 * Reimplemented the simplification procedure for proving continuity
  1818 subgoals.  The new simproc is extensible; users can declare additional
  1819 continuity introduction rules with the attribute [cont2cont].
  1820 
  1821 * The continuity simproc now uses a different introduction rule for
  1822 solving continuity subgoals on terms with lambda abstractions.  In
  1823 some rare cases the new simproc may fail to solve subgoals that the
  1824 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1825 Potential INCOMPATIBILITY.
  1826 
  1827 * Command 'fixrec': specification syntax now conforms to the general
  1828 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1829 examples.  INCOMPATIBILITY.
  1830 
  1831 
  1832 *** ZF ***
  1833 
  1834 * Proof of Zorn's Lemma for partial orders.
  1835 
  1836 
  1837 *** ML ***
  1838 
  1839 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1840 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1841 depends on multithreading, so timouts will not work before Poly/ML
  1842 5.2.1!
  1843 
  1844 * High-level support for concurrent ML programming, see
  1845 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1846 particularly convenient to organize independent functional
  1847 computations.  The concept of "synchronized variables" provides a
  1848 higher-order interface for components with shared state, avoiding the
  1849 delicate details of mutexes and condition variables.  (Requires
  1850 Poly/ML 5.2.1 or later.)
  1851 
  1852 * ML bindings produced via Isar commands are stored within the Isar
  1853 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1854 become thread-safe and work with undo as expected (concerning
  1855 top-level bindings, not side-effects on global references).
  1856 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1857 compiler at runtime; really global bindings need to be given outside a
  1858 theory.  (Requires Poly/ML 5.2 or later.)
  1859 
  1860 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1861 context.  Top-level ML bindings are stored within the proof context in
  1862 a purely sequential fashion, disregarding the nested proof structure.
  1863 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1864 proof.  (Requires Poly/ML 5.2 or later.)
  1865 
  1866 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1867 and Method.setup, as well as Isar commands 'attribute_setup' and
  1868 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1869 existing code accordingly, or use plain 'setup' together with old
  1870 Method.add_method.
  1871 
  1872 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1873 to 'a -> thm, while results are always tagged with an authentic oracle
  1874 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1875 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1876 accordingly.  Note that extra performance may be gained by producing
  1877 the cterm carefully, avoiding slow Thm.cterm_of.
  1878 
  1879 * Simplified interface for defining document antiquotations via
  1880 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1881 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1882 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1883 examples.
  1884 
  1885 * More systematic treatment of long names, abstract name bindings, and
  1886 name space operations.  Basic operations on qualified names have been
  1887 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1888 Long_Name.append.  Old type bstring has been mostly replaced by
  1889 abstract type binding (see structure Binding), which supports precise
  1890 qualification by packages and local theory targets, as well as proper
  1891 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1892 bstring values into Binding.name, or better pass through abstract
  1893 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1894 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1895 
  1896 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1897 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1898 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1899 
  1900 * Disposed old type and term read functions (Sign.read_def_typ,
  1901 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1902 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1903 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1904 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1905 resort for legacy applications.
  1906 
  1907 * Disposed old declarations, tactics, tactic combinators that refer to
  1908 the simpset or claset of an implicit theory (such as Addsimps,
  1909 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1910 embedded ML text, or local_simpset_of with a proper context passed as
  1911 explicit runtime argument.
  1912 
  1913 * Rules and tactics that read instantiations (read_instantiate,
  1914 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1915 context, which is required for parsing and type-checking.  Moreover,
  1916 the variables are specified as plain indexnames, not string encodings
  1917 thereof.  INCOMPATIBILITY.
  1918 
  1919 * Generic Toplevel.add_hook interface allows to analyze the result of
  1920 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1921 for theorem dependency output of transactions resulting in a new
  1922 theory state.
  1923 
  1924 * ML antiquotations: block-structured compilation context indicated by
  1925 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1926 
  1927   @{binding name}                         - basic name binding
  1928   @{let ?pat = term}                      - term abbreviation (HO matching)
  1929   @{note name = fact}                     - fact abbreviation
  1930   @{thm fact}                             - singleton fact (with attributes)
  1931   @{thms fact}                            - general fact (with attributes)
  1932   @{lemma prop by method}                 - singleton goal
  1933   @{lemma prop by meth1 meth2}            - singleton goal
  1934   @{lemma prop1 ... propN by method}      - general goal
  1935   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1936   @{lemma (open) ...}                     - open derivation
  1937 
  1938 
  1939 *** System ***
  1940 
  1941 * The Isabelle "emacs" tool provides a specific interface to invoke
  1942 Proof General / Emacs, with more explicit failure if that is not
  1943 installed (the old isabelle-interface script silently falls back on
  1944 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1945 installation location of the Proof General distribution.
  1946 
  1947 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1948 the Isabelle process into a JVM/Scala application.  See
  1949 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1950 process wrapper has been discontinued.)
  1951 
  1952 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1953 
  1954 * Various status messages (with exact source position information) are
  1955 emitted, if proper markup print mode is enabled.  This allows
  1956 user-interface components to provide detailed feedback on internal
  1957 prover operations.
  1958 
  1959 
  1960 
  1961 New in Isabelle2008 (June 2008)
  1962 -------------------------------
  1963 
  1964 *** General ***
  1965 
  1966 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1967 and updated, with formally checked references as hyperlinks.
  1968 
  1969 * Theory loader: use_thy (and similar operations) no longer set the
  1970 implicit ML context, which was occasionally hard to predict and in
  1971 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1972 provides a proper context already.
  1973 
  1974 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1975 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1976 'use' within a theory file will do the job.
  1977 
  1978 * Name space merge now observes canonical order, i.e. the second space
  1979 is inserted into the first one, while existing entries in the first
  1980 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1981 swap theory imports.
  1982 
  1983 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1984 INCOMPATIBILITY in identifier syntax etc.
  1985 
  1986 * Outer syntax: string tokens no longer admit escaped white space,
  1987 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1988 white space without escapes.
  1989 
  1990 * Outer syntax: string tokens may contain arbitrary character codes
  1991 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1992 "foo_bar".
  1993 
  1994 
  1995 *** Pure ***
  1996 
  1997 * Context-dependent token translations.  Default setup reverts locally
  1998 fixed variables, and adds hilite markup for undeclared frees.
  1999 
  2000 * Unused theorems can be found using the new command 'unused_thms'.
  2001 There are three ways of invoking it:
  2002 
  2003 (1) unused_thms
  2004      Only finds unused theorems in the current theory.
  2005 
  2006 (2) unused_thms thy_1 ... thy_n -
  2007      Finds unused theorems in the current theory and all of its ancestors,
  2008      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2009 
  2010 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2011      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2012      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2013      their ancestors.
  2014 
  2015 In order to increase the readability of the list produced by
  2016 unused_thms, theorems that have been created by a particular instance
  2017 of a theory command such as 'inductive' or 'function' are considered
  2018 to belong to the same "group", meaning that if at least one theorem in
  2019 this group is used, the other theorems in the same group are no longer
  2020 reported as unused.  Moreover, if all theorems in the group are
  2021 unused, only one theorem in the group is displayed.
  2022 
  2023 Note that proof objects have to be switched on in order for
  2024 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2025 usually the case when using Proof General with the default settings).
  2026 
  2027 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2028 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2029 duplicate fact bindings, or even accidental fact duplications.  Note
  2030 that tools may maintain dynamically scoped facts systematically, using
  2031 PureThy.add_thms_dynamic.
  2032 
  2033 * Command 'hide' now allows to hide from "fact" name space as well.
  2034 
  2035 * Eliminated destructive theorem database, simpset, claset, and
  2036 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2037 update of theories within ML code.
  2038 
  2039 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2040 INCOMPATIBILITY, object-logics depending on former Pure require
  2041 additional setup PureThy.old_appl_syntax_setup; object-logics
  2042 depending on former CPure need to refer to Pure.
  2043 
  2044 * Commands 'use' and 'ML' are now purely functional, operating on
  2045 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2046 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2047 INCOMPATIBILITY.
  2048 
  2049 * Command 'setup': discontinued implicit version with ML reference.
  2050 
  2051 * Instantiation target allows for simultaneous specification of class
  2052 instance operations together with an instantiation proof.
  2053 Type-checking phase allows to refer to class operations uniformly.
  2054 See src/HOL/Complex/Complex.thy for an Isar example and
  2055 src/HOL/Library/Eval.thy for an ML example.
  2056 
  2057 * Indexing of literal facts: be more serious about including only
  2058 facts from the visible specification/proof context, but not the
  2059 background context (locale etc.).  Affects `prop` notation and method
  2060 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2061 situations.
  2062 
  2063 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2064 "(open)" option, which used to expose internal bound variables to the
  2065 proof text.
  2066 
  2067 * Isar statements: removed obsolete case "rule_context".
  2068 INCOMPATIBILITY, better use explicit fixes/assumes.
  2069 
  2070 * Locale proofs: default proof step now includes 'unfold_locales';
  2071 hence 'proof' without argument may be used to unfold locale
  2072 predicates.
  2073 
  2074 
  2075 *** Document preparation ***
  2076 
  2077 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2078 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2079 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2080 spot); renamed link color from "darkblue" to "linkcolor" (default
  2081 value unchanged, can be redefined via \definecolor); no longer sets
  2082 "a4paper" option (unnecessary or even intrusive).
  2083 
  2084 * Antiquotation @{lemma A method} proves proposition A by the given
  2085 method (either a method name or a method name plus (optional) method
  2086 arguments in parentheses) and prints A just like @{prop A}.
  2087 
  2088 
  2089 *** HOL ***
  2090 
  2091 * New primrec package.  Specification syntax conforms in style to
  2092 definition/function/....  No separate induction rule is provided.  The
  2093 "primrec" command distinguishes old-style and new-style specifications
  2094 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2095 When adjusting theories, beware: constants stemming from new-style
  2096 primrec specifications have authentic syntax.
  2097 
  2098 * Metis prover is now an order of magnitude faster, and also works
  2099 with multithreading.
  2100 
  2101 * Metis: the maximum number of clauses that can be produced from a
  2102 theorem is now given by the attribute max_clauses.  Theorems that
  2103 exceed this number are ignored, with a warning printed.
  2104 
  2105 * Sledgehammer no longer produces structured proofs by default. To
  2106 enable, declare [[sledgehammer_full = true]].  Attributes
  2107 reconstruction_modulus, reconstruction_sorts renamed
  2108 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2109 
  2110 * Method "induct_scheme" derives user-specified induction rules
  2111 from well-founded induction and completeness of patterns. This factors
  2112 out some operations that are done internally by the function package
  2113 and makes them available separately.  See
  2114 src/HOL/ex/Induction_Scheme.thy for examples.
  2115 
  2116 * More flexible generation of measure functions for termination
  2117 proofs: Measure functions can be declared by proving a rule of the
  2118 form "is_measure f" and giving it the [measure_function] attribute.
  2119 The "is_measure" predicate is logically meaningless (always true), and
  2120 just guides the heuristic.  To find suitable measure functions, the
  2121 termination prover sets up the goal "is_measure ?f" of the appropriate
  2122 type and generates all solutions by prolog-style backwards proof using
  2123 the declared rules.
  2124 
  2125 This setup also deals with rules like 
  2126 
  2127   "is_measure f ==> is_measure (list_size f)"
  2128 
  2129 which accommodates nested datatypes that recurse through lists.
  2130 Similar rules are predeclared for products and option types.
  2131 
  2132 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2133 
  2134   INCOMPATIBILITIES:
  2135 
  2136   - Definitions of overloaded constants on sets have to be replaced by
  2137     definitions on => and bool.
  2138 
  2139   - Some definitions of overloaded operators on sets can now be proved
  2140     using the definitions of the operators on => and bool.  Therefore,
  2141     the following theorems have been renamed:
  2142 
  2143       subset_def   -> subset_eq
  2144       psubset_def  -> psubset_eq
  2145       set_diff_def -> set_diff_eq
  2146       Compl_def    -> Compl_eq
  2147       Sup_set_def  -> Sup_set_eq
  2148       Inf_set_def  -> Inf_set_eq
  2149       sup_set_def  -> sup_set_eq
  2150       inf_set_def  -> inf_set_eq
  2151 
  2152   - Due to the incompleteness of the HO unification algorithm, some
  2153     rules such as subst may require manual instantiation, if some of
  2154     the unknowns in the rule is a set.
  2155 
  2156   - Higher order unification and forward proofs:
  2157     The proof pattern
  2158 
  2159       have "P (S::'a set)" <...>
  2160       then have "EX S. P S" ..
  2161 
  2162     no longer works (due to the incompleteness of the HO unification
  2163     algorithm) and must be replaced by the pattern
  2164 
  2165       have "EX S. P S"
  2166       proof
  2167         show "P S" <...>
  2168       qed
  2169 
  2170   - Calculational reasoning with subst (or similar rules):
  2171     The proof pattern
  2172 
  2173       have "P (S::'a set)" <...>
  2174       also have "S = T" <...>
  2175       finally have "P T" .
  2176 
  2177     no longer works (for similar reasons as the previous example) and
  2178     must be replaced by something like
  2179 
  2180       have "P (S::'a set)" <...>
  2181       moreover have "S = T" <...>
  2182       ultimately have "P T" by simp
  2183 
  2184   - Tactics or packages written in ML code:
  2185     Code performing pattern matching on types via
  2186 
  2187       Type ("set", [T]) => ...
  2188 
  2189     must be rewritten. Moreover, functions like strip_type or
  2190     binder_types no longer return the right value when applied to a
  2191     type of the form
  2192 
  2193       T1 => ... => Tn => U => bool
  2194 
  2195     rather than
  2196 
  2197       T1 => ... => Tn => U set
  2198 
  2199 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2200 Wellfounded_Relations to theory Wellfounded.
  2201 
  2202 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2203 
  2204 * Class finite no longer treats UNIV as class parameter.  Use class
  2205 enum from theory Library/Enum instead to achieve a similar effect.
  2206 INCOMPATIBILITY.
  2207 
  2208 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2209 and "Cons".  INCOMPATIBILITY.
  2210 
  2211 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2212 Potential INCOMPATIBILITY.
  2213 
  2214 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2215 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2216 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2217 
  2218 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2219 the same name in theory Orderings:
  2220 
  2221   less_trans
  2222   less_linear
  2223   le_imp_less_or_eq
  2224   le_less_trans
  2225   less_le_trans
  2226   less_not_sym
  2227   less_asym
  2228 
  2229 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2230 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2231 and different variable names.
  2232 
  2233 * Library/Option_ord.thy: Canonical order on option type.
  2234 
  2235 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2236 finite maps.
  2237 
  2238 * Library/Countable.thy: Type class for countable types.
  2239 
  2240 * Theory Int: The representation of numerals has changed.  The infix
  2241 operator BIT and the bit datatype with constructors B0 and B1 have
  2242 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2243 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2244 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2245 accordingly.
  2246 
  2247 * Theory Nat: definition of <= and < on natural numbers no longer
  2248 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2249 le_def and less_def have disappeared.  Consider lemmas not_less
  2250 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2251 
  2252 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2253 (whose purpose mainly is for various fold_set functionals) have been
  2254 abandoned in favor of the existing algebraic classes
  2255 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2256 lower_semilattice (resp. upper_semilattice) and linorder.
  2257 INCOMPATIBILITY.
  2258 
  2259 * Theory Transitive_Closure: induct and cases rules now declare proper
  2260 case_names ("base" and "step").  INCOMPATIBILITY.
  2261 
  2262 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2263 lattices.  The form set-specific version is available as
  2264 Inductive.lfp_ordinal_induct_set.
  2265 
  2266 * Renamed theorems "power.simps" to "power_int.simps".
  2267 INCOMPATIBILITY.
  2268 
  2269 * Class semiring_div provides basic abstract properties of semirings
  2270 with division and modulo operations.  Subsumes former class dvd_mod.
  2271 
  2272 * Merged theories IntDef, Numeral and IntArith into unified theory
  2273 Int.  INCOMPATIBILITY.
  2274 
  2275 * Theory Library/Code_Index: type "index" now represents natural
  2276 numbers rather than integers.  INCOMPATIBILITY.
  2277 
  2278 * New class "uminus" with operation "uminus" (split of from class
  2279 "minus" which now only has operation "minus", binary).
  2280 INCOMPATIBILITY.
  2281 
  2282 * Constants "card", "internal_split", "option_map" now with authentic
  2283 syntax.  INCOMPATIBILITY.
  2284 
  2285 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2286 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2287 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2288 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2289 Sup_set_def, le_def, less_def, option_map_def now with object
  2290 equality.  INCOMPATIBILITY.
  2291 
  2292 * Records. Removed K_record, and replaced it by pure lambda term
  2293 %x. c. The simplifier setup is now more robust against eta expansion.
  2294 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2295 
  2296 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2297 
  2298 * Library/ListVector: new theory of arithmetic vector operations.
  2299 
  2300 * Library/Order_Relation: new theory of various orderings as sets of
  2301 pairs.  Defines preorders, partial orders, linear orders and
  2302 well-orders on sets and on types.
  2303 
  2304 
  2305 *** ZF ***
  2306 
  2307 * Renamed some theories to allow to loading both ZF and HOL in the
  2308 same session:
  2309 
  2310   Datatype  -> Datatype_ZF
  2311   Inductive -> Inductive_ZF
  2312   Int       -> Int_ZF
  2313   IntDiv    -> IntDiv_ZF
  2314   Nat       -> Nat_ZF
  2315   List      -> List_ZF
  2316   Main      -> Main_ZF
  2317 
  2318 INCOMPATIBILITY: ZF theories that import individual theories below
  2319 Main might need to be adapted.  Regular theory Main is still
  2320 available, as trivial extension of Main_ZF.
  2321 
  2322 
  2323 *** ML ***
  2324 
  2325 * ML within Isar: antiquotation @{const name} or @{const
  2326 name(typargs)} produces statically-checked Const term.
  2327 
  2328 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2329 (of the same name).  Removed obsolete print command.
  2330 
  2331 * Removed obsolete "use_legacy_bindings" function.
  2332 
  2333 * The ``print mode'' is now a thread-local value derived from a global
  2334 template (the former print_mode reference), thus access becomes
  2335 non-critical.  The global print_mode reference is for session
  2336 management only; user-code should use print_mode_value,
  2337 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2338 
  2339 * Functions system/system_out provide a robust way to invoke external
  2340 shell commands, with propagation of interrupts (requires Poly/ML
  2341 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2342 
  2343 
  2344 *** System ***
  2345 
  2346 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2347 in accordance with Proof General 3.7, which prefers GNU emacs.
  2348 
  2349 * isatool tty runs Isabelle process with plain tty interaction;
  2350 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2351 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2352 
  2353 * isatool browser now works with Cygwin as well, using general
  2354 "javapath" function defined in Isabelle process environment.
  2355 
  2356 * YXML notation provides a simple and efficient alternative to
  2357 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2358 isatool yxml as described in the Isabelle system manual.
  2359 
  2360 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2361 provides general wrapper for managing an Isabelle process in a robust
  2362 fashion, with ``cooked'' output from stdin/stderr.
  2363 
  2364 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2365 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2366 
  2367 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2368 way of changing the user's settings is via
  2369 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2370 script.
  2371 
  2372 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2373 cores of the underlying machine, which is a good starting point for
  2374 optimal performance tuning.  The corresponding usedir option -M allows
  2375 "max" as an alias for "0".  WARNING: does not work on certain versions
  2376 of Mac OS (with Poly/ML 5.1).
  2377 
  2378 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2379 adverse effect of Isabelle flooding interactive front-ends (notably
  2380 ProofGeneral / XEmacs).
  2381 
  2382 
  2383 
  2384 New in Isabelle2007 (November 2007)
  2385 -----------------------------------
  2386 
  2387 *** General ***
  2388 
  2389 * More uniform information about legacy features, notably a
  2390 warning/error of "Legacy feature: ...", depending on the state of the
  2391 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2392 legacy features will disappear eventually.
  2393 
  2394 * Theory syntax: the header format ``theory A = B + C:'' has been
  2395 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2396 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2397 
  2398 * Theory syntax: the old non-Isar theory file format has been
  2399 discontinued altogether.  Note that ML proof scripts may still be used
  2400 with Isar theories; migration is usually quite simple with the ML
  2401 function use_legacy_bindings.  INCOMPATIBILITY.
  2402 
  2403 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2404 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2405 quotes.
  2406 
  2407 * Theory loader: be more serious about observing the static theory
  2408 header specifications (including optional directories), but not the
  2409 accidental file locations of previously successful loads.  The strict
  2410 update policy of former update_thy is now already performed by
  2411 use_thy, so the former has been removed; use_thys updates several
  2412 theories simultaneously, just as 'imports' within a theory header
  2413 specification, but without merging the results.  Potential
  2414 INCOMPATIBILITY: may need to refine theory headers and commands
  2415 ROOT.ML which depend on load order.
  2416 
  2417 * Theory loader: optional support for content-based file
  2418 identification, instead of the traditional scheme of full physical
  2419 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2420 (cf. the system manual).  The new scheme allows to work with
  2421 non-finished theories in persistent session images, such that source
  2422 files may be moved later on without requiring reloads.
  2423 
  2424 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2425 file (with the same base name as the theory) are considered a legacy
  2426 feature, which will disappear eventually. Even now, the theory loader
  2427 no longer maintains dependencies on such files.
  2428 
  2429 * Syntax: the scope for resolving ambiguities via type-inference is
  2430 now limited to individual terms, instead of whole simultaneous
  2431 specifications as before. This greatly reduces the complexity of the
  2432 syntax module and improves flexibility by separating parsing and
  2433 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2434 'fixes' etc.) are required in rare situations.
  2435 
  2436 * Syntax: constants introduced by new-style packages ('definition',
  2437 'abbreviation' etc.) are passed through the syntax module in
  2438 ``authentic mode''. This means that associated mixfix annotations
  2439 really stick to such constants, independently of potential name space
  2440 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2441 trees are represented slightly differently, may need to adapt syntax
  2442 translations accordingly. Use CONST marker in 'translations' and
  2443 @{const_syntax} antiquotation in 'parse_translation' etc.
  2444 
  2445 * Legacy goal package: reduced interface to the bare minimum required
  2446 to keep existing proof scripts running.  Most other user-level
  2447 functions are now part of the OldGoals structure, which is *not* open
  2448 by default (consider isatool expandshort before open OldGoals).
  2449 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2450 these tend to cause confusion about the actual goal (!) context being
  2451 used here, which is not necessarily the same as the_context().
  2452 
  2453 * Command 'find_theorems': supports "*" wild-card in "name:"
  2454 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2455 support a specific search form (see ProofGeneral/CHANGES).
  2456 
  2457 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2458 by default, which means that "prems" (and also "fixed variables") are
  2459 suppressed from proof state output.  Note that the ProofGeneral
  2460 settings mechanism allows to change and save options persistently, but
  2461 older versions of Isabelle will fail to start up if a negative prems
  2462 limit is imposed.
  2463 
  2464 * Local theory targets may be specified by non-nested blocks of
  2465 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2466 contain definitions, theorems etc., including any derived mechanism
  2467 that has been implemented on top of these primitives.  This concept
  2468 generalizes the existing ``theorem (in ...)'' towards more versatility
  2469 and scalability.
  2470 
  2471 * Proof General interface: proper undo of final 'end' command;
  2472 discontinued Isabelle/classic mode (ML proof scripts).
  2473 
  2474 
  2475 *** Document preparation ***
  2476 
  2477 * Added antiquotation @{theory name} which prints the given name,
  2478 after checking that it refers to a valid ancestor theory in the
  2479 current context.
  2480 
  2481 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2482 check the given source text as ML type/structure, printing verbatim.
  2483 
  2484 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2485 "c args == rhs" given in the current context.  (Any number of
  2486 arguments may be given on the LHS.)
  2487 
  2488 
  2489 *** Pure ***
  2490 
  2491 * The 'class' package offers a combination of axclass and locale to
  2492 achieve Haskell-like type classes in Isabelle.  Definitions and
  2493 theorems within a class context produce both relative results (with
  2494 implicit parameters according to the locale context), and polymorphic
  2495 constants with qualified polymorphism (according to the class
  2496 context).  Within the body context of a 'class' target, a separate
  2497 syntax layer ("user space type system") takes care of converting
  2498 between global polymorphic consts and internal locale representation.
  2499 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2500 "isatool doc classes" provides a tutorial.
  2501 
  2502 * Generic code generator framework allows to generate executable
  2503 code for ML and Haskell (including Isabelle classes).  A short usage
  2504 sketch:
  2505 
  2506     internal compilation:
  2507         export_code <list of constants (term syntax)> in SML
  2508     writing SML code to a file:
  2509         export_code <list of constants (term syntax)> in SML <filename>
  2510     writing OCaml code to a file:
  2511         export_code <list of constants (term syntax)> in OCaml <filename>
  2512     writing Haskell code to a bunch of files:
  2513         export_code <list of constants (term syntax)> in Haskell <filename>
  2514 
  2515     evaluating closed propositions to True/False using code generation:
  2516         method ``eval''
  2517 
  2518 Reasonable default setup of framework in HOL.
  2519 
  2520 Theorem attributs for selecting and transforming function equations theorems:
  2521 
  2522     [code fun]:        select a theorem as function equation for a specific constant
  2523     [code fun del]:    deselect a theorem as function equation for a specific constant
  2524     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2525     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2526 
  2527 User-defined serializations (target in {SML, OCaml, Haskell}):
  2528 
  2529     code_const <and-list of constants (term syntax)>
  2530       {(target) <and-list of const target syntax>}+
  2531 
  2532     code_type <and-list of type constructors>
  2533       {(target) <and-list of type target syntax>}+
  2534 
  2535     code_instance <and-list of instances>
  2536       {(target)}+
  2537         where instance ::= <type constructor> :: <class>
  2538 
  2539     code_class <and_list of classes>
  2540       {(target) <and-list of class target syntax>}+
  2541         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2542 
  2543 code_instance and code_class only are effective to target Haskell.
  2544 
  2545 For example usage see src/HOL/ex/Codegenerator.thy and
  2546 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2547 generation from Isabelle/HOL theories is available via "isatool doc
  2548 codegen".
  2549 
  2550 * Code generator: consts in 'consts_code' Isar commands are now
  2551 referred to by usual term syntax (including optional type
  2552 annotations).
  2553 
  2554 * Command 'no_translations' removes translation rules from theory
  2555 syntax.
  2556 
  2557 * Overloaded definitions are now actually checked for acyclic
  2558 dependencies.  The overloading scheme is slightly more general than
  2559 that of Haskell98, although Isabelle does not demand an exact
  2560 correspondence to type class and instance declarations.
  2561 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2562 exotic versions of overloading -- at the discretion of the user!
  2563 
  2564 Polymorphic constants are represented via type arguments, i.e. the
  2565 instantiation that matches an instance against the most general
  2566 declaration given in the signature.  For example, with the declaration
  2567 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2568 as c(nat).  Overloading is essentially simultaneous structural
  2569 recursion over such type arguments.  Incomplete specification patterns
  2570 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2571 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2572 Command 'print_theory' outputs the normalized system of recursive
  2573 equations, see section "definitions".
  2574 
  2575 * Configuration options are maintained within the theory or proof
  2576 context (with name and type bool/int/string), providing a very simple
  2577 interface to a poor-man's version of general context data.  Tools may
  2578 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2579 these values using Config.get etc.  Users may change options via an
  2580 associated attribute of the same name.  This form of context
  2581 declaration works particularly well with commands 'declare' or
  2582 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2583 very easy to avoid global references, which would not observe Isar
  2584 toplevel undo/redo and fail to work with multithreading.
  2585 
  2586 Various global ML references of Pure and HOL have been turned into
  2587 configuration options:
  2588 
  2589   Unify.search_bound		unify_search_bound
  2590   Unify.trace_bound		unify_trace_bound
  2591   Unify.trace_simp		unify_trace_simp
  2592   Unify.trace_types		unify_trace_types
  2593   Simplifier.simp_depth_limit	simp_depth_limit
  2594   Blast.depth_limit		blast_depth_limit
  2595   DatatypeProp.dtK		datatype_distinctness_limit
  2596   fast_arith_neq_limit  	fast_arith_neq_limit
  2597   fast_arith_split_limit	fast_arith_split_limit
  2598 
  2599 * Named collections of theorems may be easily installed as context
  2600 data using the functor NamedThmsFun (see also
  2601 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2602 attributes; there is also a toplevel print command.  This facility is
  2603 just a common case of general context data, which is the preferred way
  2604 for anything more complex than just a list of facts in canonical
  2605 order.
  2606 
  2607 * Isar: command 'declaration' augments a local theory by generic
  2608 declaration functions written in ML.  This enables arbitrary content
  2609 being added to the context, depending on a morphism that tells the
  2610 difference of the original declaration context wrt. the application
  2611 context encountered later on.
  2612 
  2613 * Isar: proper interfaces for simplification procedures.  Command
  2614 'simproc_setup' declares named simprocs (with match patterns, and body
  2615 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2616 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2617 
  2618 * Isar: an extra pair of brackets around attribute declarations
  2619 abbreviates a theorem reference involving an internal dummy fact,
  2620 which will be ignored later --- only the effect of the attribute on
  2621 the background context will persist.  This form of in-place
  2622 declarations is particularly useful with commands like 'declare' and
  2623 'using', for example ``have A using [[simproc a]] by simp''.
  2624 
  2625 * Isar: method "assumption" (and implicit closing of subproofs) now
  2626 takes simple non-atomic goal assumptions into account: after applying
  2627 an assumption as a rule the resulting subgoals are solved by atomic
  2628 assumption steps.  This is particularly useful to finish 'obtain'
  2629 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2630 without referring to the original premise "!!x. P x ==> thesis" in the
  2631 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2632 more permissive.
  2633 
  2634 * Isar: implicit use of prems from the Isar proof context is
  2635 considered a legacy feature.  Common applications like ``have A .''
  2636 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2637 referencing facts explicitly here improves readability and
  2638 maintainability of proof texts.
  2639 
  2640 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2641 the obtained context from the course of reasoning!  For example:
  2642 
  2643   assume "EX x y. A x & B y"   -- "any previous fact"
  2644   then guess x and y by clarify
  2645 
  2646 This technique is potentially adventurous, depending on the facts and
  2647 proof tools being involved here.
  2648 
  2649 * Isar: known facts from the proof context may be specified as literal
  2650 propositions, using ASCII back-quote syntax.  This works wherever
  2651 named facts used to be allowed so far, in proof commands, proof
  2652 methods, attributes etc.  Literal facts are retrieved from the context
  2653 according to unification of type and term parameters.  For example,
  2654 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2655 theorems in the current context, then these are valid literal facts:
  2656 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2657 
  2658 There is also a proof method "fact" which does the same composition
  2659 for explicit goal states, e.g. the following proof texts coincide with
  2660 certain special cases of literal facts:
  2661 
  2662   have "A" by fact                 ==  note `A`
  2663   have "A ==> B" by fact           ==  note `A ==> B`
  2664   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2665   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2666 
  2667 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2668 outer syntax.  Thus symbolic identifiers may be used without
  2669 additional white space in declarations like this: ``assume *: A''.
  2670 
  2671 * Isar: 'print_facts' prints all local facts of the current context,
  2672 both named and unnamed ones.
  2673 
  2674 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2675 
  2676   def x == "t" and y == "u"
  2677 
  2678 * Isar: added command 'unfolding', which is structurally similar to
  2679 'using', but affects both the goal state and facts by unfolding given
  2680 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2681 'unfolded' attribute may be replaced by first-class proof text.
  2682 
  2683 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2684 and command 'unfolding' now all support object-level equalities
  2685 (potentially conditional).  The underlying notion of rewrite rule is
  2686 analogous to the 'rule_format' attribute, but *not* that of the
  2687 Simplifier (which is usually more generous).
  2688 
  2689 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2690 premises of a theorem by n. Useful in conjunction with drule.
  2691 
  2692 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2693 method expression within a sandbox consisting of the first N
  2694 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2695 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2696 simplifies all new goals that emerge from applying rule foo to the
  2697 originally first one.
  2698 
  2699 * Isar: schematic goals are no longer restricted to higher-order
  2700 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2701 expected.
  2702 
  2703 * Isar: the conclusion of a long theorem statement is now either
  2704 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2705 (essentially a disjunction of cases with local parameters and
  2706 assumptions).  The latter allows to express general elimination rules
  2707 adequately; in this notation common elimination rules look like this:
  2708 
  2709   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2710     assumes "EX x. P x"
  2711     obtains x where "P x"
  2712 
  2713   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2714     assumes "A & B"
  2715     obtains A and B
  2716 
  2717   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2718     assumes "A | B"
  2719     obtains
  2720       A
  2721     | B
  2722 
  2723 The subsequent classical rules even refer to the formal "thesis"
  2724 explicitly:
  2725 
  2726   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2727     obtains "~ thesis"
  2728 
  2729   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2730     obtains "thesis ==> something"
  2731 
  2732 The actual proof of an 'obtains' statement is analogous to that of the
  2733 Isar proof element 'obtain', only that there may be several cases.
  2734 Optional case names may be specified in parentheses; these will be
  2735 available both in the present proof and as annotations in the
  2736 resulting rule, for later use with the 'cases' method (cf. attribute
  2737 case_names).
  2738 
  2739 * Isar: the assumptions of a long theorem statement are available as
  2740 "assms" fact in the proof context.  This is more appropriate than the
  2741 (historical) "prems", which refers to all assumptions of the current
  2742 context, including those from the target locale, proof body etc.
  2743 
  2744 * Isar: 'print_statement' prints theorems from the current theory or
  2745 proof context in long statement form, according to the syntax of a
  2746 top-level lemma.
  2747 
  2748 * Isar: 'obtain' takes an optional case name for the local context
  2749 introduction rule (default "that").
  2750 
  2751 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2752 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2753 to occur.
  2754 
  2755 * Pure: syntax "CONST name" produces a fully internalized constant
  2756 according to the current context.  This is particularly useful for
  2757 syntax translations that should refer to internal constant
  2758 representations independently of name spaces.
  2759 
  2760 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2761 instead of "FOO ". This allows multiple binder declarations to coexist
  2762 in the same context.  INCOMPATIBILITY.
  2763 
  2764 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2765 primitive that also works in a locale context (both for constants and
  2766 fixed variables). Type declaration and internal syntactic representation
  2767 of given constants retrieved from the context. Likewise, the
  2768 'no_notation' command allows to remove given syntax annotations from the
  2769 current context.
  2770 
  2771 * Isar/locales: new derived specification elements 'axiomatization',
  2772 'definition', 'abbreviation', which support type-inference, admit
  2773 object-level specifications (equality, equivalence).  See also the
  2774 isar-ref manual.  Examples:
  2775 
  2776   axiomatization
  2777     eq  (infix "===" 50) where
  2778     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2779 
  2780   definition "f x y = x + y + 1"
  2781   definition g where "g x = f x x"
  2782 
  2783   abbreviation
  2784     neq  (infix "=!=" 50) where
  2785     "x =!= y == ~ (x === y)"
  2786 
  2787 These specifications may be also used in a locale context.  Then the
  2788 constants being introduced depend on certain fixed parameters, and the
  2789 constant name is qualified by the locale base name.  An internal
  2790 abbreviation takes care for convenient input and output, making the
  2791 parameters implicit and using the original short name.  See also
  2792 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2793 entities from a monomorphic theory.
  2794 
  2795 Presently, abbreviations are only available 'in' a target locale, but
  2796 not inherited by general import expressions.  Also note that
  2797 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2798 'translations' in common applications.  The "no_abbrevs" print mode
  2799 prevents folding of abbreviations in term output.
  2800 
  2801 Concrete syntax is attached to specified constants in internal form,
  2802 independently of name spaces.  The parse tree representation is
  2803 slightly different -- use 'notation' instead of raw 'syntax', and
  2804 'translations' with explicit "CONST" markup to accommodate this.
  2805 
  2806 * Pure/Isar: unified syntax for new-style specification mechanisms
  2807 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2808 full type inference and dummy patterns ("_").  For example:
  2809 
  2810   definition "K x _ = x"
  2811 
  2812   inductive conj for A B
  2813   where "A ==> B ==> conj A B"
  2814 
  2815 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2816 the current context.  Print mode "no_abbrevs" prevents inversion of
  2817 abbreviations on output.
  2818 
  2819 * Isar/locales: improved parameter handling: use of locales "var" and
  2820 "struct" no longer necessary; - parameter renamings are no longer
  2821 required to be injective.  For example, this allows to define
  2822 endomorphisms as locale endom = homom mult mult h.
  2823 
  2824 * Isar/locales: changed the way locales with predicates are defined.
  2825 Instead of accumulating the specification, the imported expression is
  2826 now an interpretation.  INCOMPATIBILITY: different normal form of
  2827 locale expressions.  In particular, in interpretations of locales with
  2828 predicates, goals repesenting already interpreted fragments are not
  2829 removed automatically.  Use methods `intro_locales' and
  2830 `unfold_locales'; see below.
  2831 
  2832 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2833 provide backward reasoning on locales predicates.  The methods are
  2834 aware of interpretations and discharge corresponding goals.
  2835 `intro_locales' is less aggressive then `unfold_locales' and does not
  2836 unfold predicates to assumptions.
  2837 
  2838 * Isar/locales: the order in which locale fragments are accumulated
  2839 has changed.  This enables to override declarations from fragments due
  2840 to interpretations -- for example, unwanted simp rules.
  2841 
  2842 * Isar/locales: interpretation in theories and proof contexts has been
  2843 extended.  One may now specify (and prove) equations, which are
  2844 unfolded in interpreted theorems.  This is useful for replacing
  2845 defined concepts (constants depending on locale parameters) by
  2846 concepts already existing in the target context.  Example:
  2847 
  2848   interpretation partial_order ["op <= :: [int, int] => bool"]
  2849     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2850 
  2851 Typically, the constant `partial_order.less' is created by a
  2852 definition specification element in the context of locale
  2853 partial_order.
  2854 
  2855 * Method "induct": improved internal context management to support
  2856 local fixes and defines on-the-fly. Thus explicit meta-level
  2857 connectives !!  and ==> are rarely required anymore in inductive goals
  2858 (using object-logic connectives for this purpose has been long
  2859 obsolete anyway). Common proof patterns are explained in
  2860 src/HOL/Induct/Common_Patterns.thy, see also
  2861 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2862 examples.
  2863 
  2864 * Method "induct": improved handling of simultaneous goals. Instead of
  2865 introducing object-level conjunction, the statement is now split into
  2866 several conclusions, while the corresponding symbolic cases are nested
  2867 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2868 see src/HOL/Induct/Common_Patterns.thy, for example.
  2869 
  2870 * Method "induct": mutual induction rules are now specified as a list
  2871 of rule sharing the same induction cases. HOL packages usually provide
  2872 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2873 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2874 mutual induction rules differently, i.e. like this:
  2875 
  2876   (induct rule: foo_bar.inducts)
  2877   (induct set: foo bar)
  2878   (induct pred: foo bar)
  2879   (induct type: foo bar)
  2880 
  2881 The ML function ProjectRule.projections turns old-style rules into the
  2882 new format.
  2883 
  2884 * Method "coinduct": dual of induction, see
  2885 src/HOL/Library/Coinductive_List.thy for various examples.
  2886 
  2887 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2888 considered a legacy feature.
  2889 
  2890 * Attribute "symmetric" produces result with standardized schematic
  2891 variables (index 0).  Potential INCOMPATIBILITY.
  2892 
  2893 * Simplifier: by default the simplifier trace only shows top level
  2894 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2895 default. Thus there is less danger of being flooded by the trace. The
  2896 trace indicates where parts have been suppressed.
  2897   
  2898 * Provers/classical: removed obsolete classical version of elim_format
  2899 attribute; classical elim/dest rules are now treated uniformly when
  2900 manipulating the claset.
  2901 
  2902 * Provers/classical: stricter checks to ensure that supplied intro,
  2903 dest and elim rules are well-formed; dest and elim rules must have at
  2904 least one premise.
  2905 
  2906 * Provers/classical: attributes dest/elim/intro take an optional
  2907 weight argument for the rule (just as the Pure versions).  Weights are
  2908 ignored by automated tools, but determine the search order of single
  2909 rule steps.
  2910 
  2911 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2912 where the body does not mention the bound variable.  Note that dummy
  2913 patterns implicitly depend on their context of bounds, which makes
  2914 "{_. _}" match any set comprehension as expected.  Potential
  2915 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2916 constant "_idtdummy" in the binding position.
  2917 
  2918 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2919 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2920 for example "A -> B" => "Pi A (%_. B)".
  2921 
  2922 * Pure: 'class_deps' command visualizes the subclass relation, using
  2923 the graph browser tool.
  2924 
  2925 * Pure: 'print_theory' now suppresses certain internal declarations by
  2926 default; use '!' option for full details.
  2927 
  2928 
  2929 *** HOL ***
  2930 
  2931 * Method "metis" proves goals by applying the Metis general-purpose
  2932 resolution prover (see also http://gilith.com/software/metis/).
  2933 Examples are in the directory MetisExamples.  WARNING: the
  2934 Isabelle/HOL-Metis integration does not yet work properly with
  2935 multi-threading.
  2936   
  2937 * Command 'sledgehammer' invokes external automatic theorem provers as
  2938 background processes.  It generates calls to the "metis" method if
  2939 successful. These can be pasted into the proof.  Users do not have to
  2940 wait for the automatic provers to return.  WARNING: does not really
  2941 work with multi-threading.
  2942 
  2943 * New "auto_quickcheck" feature tests outermost goal statements for
  2944 potential counter-examples.  Controlled by ML references
  2945 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2946 5000 milliseconds).  Fails silently if statements is outside of
  2947 executable fragment, or any other codgenerator problem occurs.
  2948 
  2949 * New constant "undefined" with axiom "undefined x = undefined".
  2950 
  2951 * Added class "HOL.eq", allowing for code generation with polymorphic
  2952 equality.
  2953 
  2954 * Some renaming of class constants due to canonical name prefixing in
  2955 the new 'class' package:
  2956 
  2957     HOL.abs ~> HOL.abs_class.abs
  2958     HOL.divide ~> HOL.divide_class.divide
  2959     0 ~> HOL.zero_class.zero
  2960     1 ~> HOL.one_class.one
  2961     op + ~> HOL.plus_class.plus
  2962     op - ~> HOL.minus_class.minus
  2963     uminus ~> HOL.minus_class.uminus
  2964     op * ~> HOL.times_class.times
  2965     op < ~> HOL.ord_class.less
  2966     op <= > HOL.ord_class.less_eq
  2967     Nat.power ~> Power.power_class.power
  2968     Nat.size ~> Nat.size_class.size
  2969     Numeral.number_of ~> Numeral.number_class.number_of
  2970     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2971     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2972     Orderings.min ~> Orderings.ord_class.min
  2973     Orderings.max ~> Orderings.ord_class.max
  2974     Divides.op div ~> Divides.div_class.div
  2975     Divides.op mod ~> Divides.div_class.mod
  2976     Divides.op dvd ~> Divides.div_class.dvd
  2977 
  2978 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2979 
  2980 a) User-defined constants using any of the names "plus", "minus",
  2981 "times", "less" or "less_eq". The standard syntax translations for
  2982 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2983 names.
  2984 
  2985 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2986 INCOMPATIBILITY: use more specific names.
  2987 
  2988 c) Permutative equations (e.g. "a + b = b + a")
  2989 Since the change of names also changes the order of terms, permutative
  2990 rewrite rules may get applied in a different order. Experience shows
  2991 that this is rarely the case (only two adaptions in the whole Isabelle
  2992 distribution).  INCOMPATIBILITY: rewrite proofs
  2993 
  2994 d) ML code directly refering to constant names
  2995 This in general only affects hand-written proof tactics, simprocs and
  2996 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2997 Consider using @{const_name} antiquotation.
  2998 
  2999 * New class "default" with associated constant "default".
  3000 
  3001 * Function "sgn" is now overloaded and available on int, real, complex
  3002 (and other numeric types), using class "sgn".  Two possible defs of
  3003 sgn are given as equational assumptions in the classes sgn_if and
  3004 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3005 INCOMPATIBILITY.
  3006 
  3007 * Locale "partial_order" now unified with class "order" (cf. theory
  3008 Orderings), added parameter "less".  INCOMPATIBILITY.
  3009 
  3010 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3011 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3012 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3013 
  3014 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3015 changed order of proof goals in instance proofs.
  3016 
  3017 * The transitivity reasoner for partial and linear orders is set up
  3018 for classes "order" and "linorder".  Instances of the reasoner are available
  3019 in all contexts importing or interpreting the corresponding locales.
  3020 Method "order" invokes the reasoner separately; the reasoner
  3021 is also integrated with the Simplifier as a solver.  Diagnostic
  3022 command 'print_orders' shows the available instances of the reasoner
  3023 in the current context.
  3024 
  3025 * Localized monotonicity predicate in theory "Orderings"; integrated
  3026 lemmas max_of_mono and min_of_mono with this predicate.
  3027 INCOMPATIBILITY.
  3028 
  3029 * Formulation of theorem "dense" changed slightly due to integration
  3030 with new class dense_linear_order.
  3031 
  3032 * Uniform lattice theory development in HOL.
  3033 
  3034     constants "meet" and "join" now named "inf" and "sup"
  3035     constant "Meet" now named "Inf"
  3036 
  3037     classes "meet_semilorder" and "join_semilorder" now named
  3038       "lower_semilattice" and "upper_semilattice"
  3039     class "lorder" now named "lattice"
  3040     class "comp_lat" now named "complete_lattice"
  3041 
  3042     Instantiation of lattice classes allows explicit definitions
  3043     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3044 
  3045   INCOMPATIBILITY.  Theorem renames:
  3046 
  3047     meet_left_le            ~> inf_le1
  3048     meet_right_le           ~> inf_le2
  3049     join_left_le            ~> sup_ge1
  3050     join_right_le           ~> sup_ge2
  3051     meet_join_le            ~> inf_sup_ord
  3052     le_meetI                ~> le_infI
  3053     join_leI                ~> le_supI
  3054     le_meet                 ~> le_inf_iff
  3055     le_join                 ~> ge_sup_conv
  3056     meet_idempotent         ~> inf_idem
  3057     join_idempotent         ~> sup_idem
  3058     meet_comm               ~> inf_commute
  3059     join_comm               ~> sup_commute
  3060     meet_leI1               ~> le_infI1
  3061     meet_leI2               ~> le_infI2
  3062     le_joinI1               ~> le_supI1
  3063     le_joinI2               ~> le_supI2
  3064     meet_assoc              ~> inf_assoc
  3065     join_assoc              ~> sup_assoc
  3066     meet_left_comm          ~> inf_left_commute
  3067     meet_left_idempotent    ~> inf_left_idem
  3068     join_left_comm          ~> sup_left_commute
  3069     join_left_idempotent    ~> sup_left_idem
  3070     meet_aci                ~> inf_aci
  3071     join_aci                ~> sup_aci
  3072     le_def_meet             ~> le_iff_inf
  3073     le_def_join             ~> le_iff_sup
  3074     join_absorp2            ~> sup_absorb2
  3075     join_absorp1            ~> sup_absorb1
  3076     meet_absorp1            ~> inf_absorb1
  3077     meet_absorp2            ~> inf_absorb2
  3078     meet_join_absorp        ~> inf_sup_absorb
  3079     join_meet_absorp        ~> sup_inf_absorb
  3080     distrib_join_le         ~> distrib_sup_le
  3081     distrib_meet_le         ~> distrib_inf_le
  3082 
  3083     add_meet_distrib_left   ~> add_inf_distrib_left
  3084     add_join_distrib_left   ~> add_sup_distrib_left
  3085     is_join_neg_meet        ~> is_join_neg_inf
  3086     is_meet_neg_join        ~> is_meet_neg_sup
  3087     add_meet_distrib_right  ~> add_inf_distrib_right
  3088     add_join_distrib_right  ~> add_sup_distrib_right
  3089     add_meet_join_distribs  ~> add_sup_inf_distribs
  3090     join_eq_neg_meet        ~> sup_eq_neg_inf
  3091     meet_eq_neg_join        ~> inf_eq_neg_sup
  3092     add_eq_meet_join        ~> add_eq_inf_sup
  3093     meet_0_imp_0            ~> inf_0_imp_0
  3094     join_0_imp_0            ~> sup_0_imp_0
  3095     meet_0_eq_0             ~> inf_0_eq_0
  3096     join_0_eq_0             ~> sup_0_eq_0
  3097     neg_meet_eq_join        ~> neg_inf_eq_sup
  3098     neg_join_eq_meet        ~> neg_sup_eq_inf
  3099     join_eq_if              ~> sup_eq_if
  3100 
  3101     mono_meet               ~> mono_inf
  3102     mono_join               ~> mono_sup
  3103     meet_bool_eq            ~> inf_bool_eq
  3104     join_bool_eq            ~> sup_bool_eq
  3105     meet_fun_eq             ~> inf_fun_eq
  3106     join_fun_eq             ~> sup_fun_eq
  3107     meet_set_eq             ~> inf_set_eq
  3108     join_set_eq             ~> sup_set_eq
  3109     meet1_iff               ~> inf1_iff
  3110     meet2_iff               ~> inf2_iff
  3111     meet1I                  ~> inf1I
  3112     meet2I                  ~> inf2I
  3113     meet1D1                 ~> inf1D1
  3114     meet2D1                 ~> inf2D1
  3115     meet1D2                 ~> inf1D2
  3116     meet2D2                 ~> inf2D2
  3117     meet1E                  ~> inf1E
  3118     meet2E                  ~> inf2E
  3119     join1_iff               ~> sup1_iff
  3120     join2_iff               ~> sup2_iff
  3121     join1I1                 ~> sup1I1
  3122     join2I1                 ~> sup2I1
  3123     join1I1                 ~> sup1I1
  3124     join2I2                 ~> sup1I2
  3125     join1CI                 ~> sup1CI
  3126     join2CI                 ~> sup2CI
  3127     join1E                  ~> sup1E
  3128     join2E                  ~> sup2E
  3129 
  3130     is_meet_Meet            ~> is_meet_Inf
  3131     Meet_bool_def           ~> Inf_bool_def
  3132     Meet_fun_def            ~> Inf_fun_def
  3133     Meet_greatest           ~> Inf_greatest
  3134     Meet_lower              ~> Inf_lower
  3135     Meet_set_def            ~> Inf_set_def
  3136 
  3137     Sup_def                 ~> Sup_Inf
  3138     Sup_bool_eq             ~> Sup_bool_def
  3139     Sup_fun_eq              ~> Sup_fun_def
  3140     Sup_set_eq              ~> Sup_set_def
  3141 
  3142     listsp_meetI            ~> listsp_infI
  3143     listsp_meet_eq          ~> listsp_inf_eq
  3144 
  3145     meet_min                ~> inf_min
  3146     join_max                ~> sup_max
  3147 
  3148 * Added syntactic class "size"; overloaded constant "size" now has
  3149 type "'a::size ==> bool"
  3150 
  3151 * Internal reorganisation of `size' of datatypes: size theorems
  3152 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3153 simplification rules by default!); theorems "prod.size" now named
  3154 "*.size".
  3155 
  3156 * Class "div" now inherits from class "times" rather than "type".
  3157 INCOMPATIBILITY.
  3158 
  3159 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3160 Linorder etc.  have disappeared; operations defined in terms of
  3161 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3162 
  3163 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3164 
  3165 * HOL-Word: New extensive library and type for generic, fixed size
  3166 machine words, with arithemtic, bit-wise, shifting and rotating
  3167 operations, reflection into int, nat, and bool lists, automation for
  3168 linear arithmetic (by automatic reflection into nat or int), including
  3169 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3170 arithmetic type classes, supporting automatic simplification of
  3171 numerals on all operations.
  3172 
  3173 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3174 
  3175 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3176 
  3177 * Code generator library theories:
  3178   - Code_Integer represents HOL integers by big integer literals in target
  3179     languages.
  3180   - Code_Char represents HOL characters by character literals in target
  3181     languages.
  3182   - Code_Char_chr like Code_Char, but also offers treatment of character
  3183     codes; includes Code_Integer.
  3184   - Executable_Set allows to generate code for finite sets using lists.
  3185   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3186     denominator).
  3187   - Executable_Real implements a subset of real numbers, namly those
  3188     representable by rational numbers.
  3189   - Efficient_Nat implements natural numbers by integers, which in general will
  3190     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3191     includes Code_Integer.
  3192   - Code_Index provides an additional datatype index which is mapped to
  3193     target-language built-in integers.
  3194   - Code_Message provides an additional datatype message_string which is isomorphic to
  3195     strings; messages are mapped to target-language strings.
  3196 
  3197 * New package for inductive predicates
  3198 
  3199   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3200 
  3201     inductive
  3202       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3203       for z_1 :: U_1 and ... and z_n :: U_m
  3204     where
  3205       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3206     | ...
  3207 
  3208   with full support for type-inference, rather than
  3209 
  3210     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3211 
  3212     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3213     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3214 
  3215     inductive "s z_1 ... z_m"
  3216     intros
  3217       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3218       ...
  3219 
  3220   For backward compatibility, there is a wrapper allowing inductive
  3221   sets to be defined with the new package via
  3222 
  3223     inductive_set
  3224       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3225       for z_1 :: U_1 and ... and z_n :: U_m
  3226     where
  3227       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3228     | ...
  3229 
  3230   or
  3231 
  3232     inductive_set
  3233       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3234       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3235       for z_1 :: U_1 and ... and z_n :: U_m
  3236     where
  3237       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3238     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3239     | ...
  3240 
  3241   if the additional syntax "p ..." is required.
  3242 
  3243   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3244   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3245 
  3246   INCOMPATIBILITIES:
  3247 
  3248   - Since declaration and definition of inductive sets or predicates
  3249     is no longer separated, abbreviations involving the newly
  3250     introduced sets or predicates must be specified together with the
  3251     introduction rules after the 'where' keyword (see above), rather
  3252     than before the actual inductive definition.
  3253 
  3254   - The variables in induction and elimination rules are now
  3255     quantified in the order of their occurrence in the introduction
  3256     rules, rather than in alphabetical order. Since this may break
  3257     some proofs, these proofs either have to be repaired, e.g. by
  3258     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3259     statements of the form
  3260 
  3261       case (rule_i a_i_1 ... a_i_{k_i})
  3262 
  3263     or the old order of quantification has to be restored by explicitly adding
  3264     meta-level quantifiers in the introduction rules, i.e.
  3265 
  3266       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3267 
  3268   - The format of the elimination rules is now
  3269 
  3270       p z_1 ... z_m x_1 ... x_n ==>
  3271         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3272         ==> ... ==> P
  3273 
  3274     for predicates and
  3275 
  3276       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3277         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3278         ==> ... ==> P
  3279 
  3280     for sets rather than
  3281 
  3282       x : s z_1 ... z_m ==>
  3283         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3284         ==> ... ==> P
  3285 
  3286     This may require terms in goals to be expanded to n-tuples
  3287     (e.g. using case_tac or simplification with the split_paired_all
  3288     rule) before the above elimination rule is applicable.
  3289 
  3290   - The elimination or case analysis rules for (mutually) inductive
  3291     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3292     list of rules "p_1_..._p_k.elims" is no longer available.
  3293 
  3294 * New package "function"/"fun" for general recursive functions,
  3295 supporting mutual and nested recursion, definitions in local contexts,
  3296 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3297 for small examples, and the separate tutorial on the function
  3298 package. The old recdef "package" is still available as before, but
  3299 users are encouraged to use the new package.
  3300 
  3301 * Method "lexicographic_order" automatically synthesizes termination
  3302 relations as lexicographic combinations of size measures. 
  3303 
  3304 * Case-expressions allow arbitrary constructor-patterns (including
  3305 "_") and take their order into account, like in functional
  3306 programming.  Internally, this is translated into nested
  3307 case-expressions; missing cases are added and mapped to the predefined
  3308 constant "undefined". In complicated cases printing may no longer show
  3309 the original input but the internal form. Lambda-abstractions allow
  3310 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3311 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3312 variable.
  3313 
  3314 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3315 is an abbreviation for "of_nat :: nat => int". The simplification
  3316 rules for "of_nat" have been changed to work like "int" did
  3317 previously.  Potential INCOMPATIBILITY:
  3318   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3319   - of_nat_diff and of_nat_mult are no longer default simp rules
  3320 
  3321 * Method "algebra" solves polynomial equations over (semi)rings using
  3322 Groebner bases. The (semi)ring structure is defined by locales and the
  3323 tool setup depends on that generic context. Installing the method for
  3324 a specific type involves instantiating the locale and possibly adding
  3325 declarations for computation on the coefficients.  The method is
  3326 already instantiated for natural numbers and for the axiomatic class
  3327 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3328 CALCULEMUS 2007 for the general principles underlying this
  3329 architecture of context-aware proof-tools.
  3330 
  3331 * Method "ferrack" implements quantifier elimination over
  3332 special-purpose dense linear orders using locales (analogous to
  3333 "algebra"). The method is already installed for class
  3334 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3335 rat, etc.
  3336 
  3337 * Former constant "List.op @" now named "List.append".  Use ML
  3338 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3339 circumvent possible incompatibilities when working on ML level.
  3340 
  3341 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3342 
  3343 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3344 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3345 
  3346 * New syntax for Haskell-like list comprehension (input only), eg.
  3347 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3348 
  3349 * The special syntax for function "filter" has changed from [x :
  3350 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3351 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3352 
  3353 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3354 defined on nat only, as an abbreviation for [a..<Suc b]
  3355 INCOMPATIBILITY.
  3356 
  3357 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3358 
  3359 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3360 
  3361 * New lemma collection field_simps (an extension of ring_simps) for
  3362 manipulating (in)equations involving division. Multiplies with all
  3363 denominators that can be proved to be non-zero (in equations) or
  3364 positive/negative (in inequations).
  3365 
  3366 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3367 have been improved and renamed to ring_simps, group_simps and
  3368 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3369 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3370 
  3371 * Theory Library/Commutative_Ring: switched from recdef to function
  3372 package; constants add, mul, pow now curried.  Infix syntax for
  3373 algebraic operations.
  3374 
  3375 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3376 INCOMPATIBILITY.
  3377 
  3378 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3379 INCOMPATIBILITY.
  3380 
  3381 * HOL/records: generalised field-update to take a function on the
  3382 field rather than the new value: r(|A := x|) is translated to A_update
  3383 (K x) r The K-combinator that is internally used is called K_record.
  3384 INCOMPATIBILITY: Usage of the plain update functions has to be
  3385 adapted.
  3386  
  3387 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3388 * x = 0, which are required for a semiring.  Richer structures do not
  3389 inherit from semiring_0 anymore, because this property is a theorem
  3390 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3391 there is more to prove, but this is mostly trivial.
  3392 
  3393 * Class "recpower" is generalized to arbitrary monoids, not just
  3394 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3395 commutativity or semiring properties additionally.
  3396 
  3397 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3398 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3399 better use 'abbreviation'.
  3400 
  3401 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3402 
  3403 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3404 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3405 significant changes for setting up numeral syntax for types:
  3406   - New constants Numeral.pred and Numeral.succ instead
  3407       of former Numeral.bin_pred and Numeral.bin_succ.
  3408   - Use integer operations instead of bin_add, bin_mult and so on.
  3409   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3410   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3411 
  3412 See src/HOL/Integ/IntArith.thy for an example setup.
  3413 
  3414 * Command 'normal_form' computes the normal form of a term that may
  3415 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3416 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3417 heavy-duty computations because the functions are compiled to ML
  3418 first.  Correspondingly, a method "normalization" is provided.  See
  3419 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3420 
  3421 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3422 25 like -->); output depends on the "iff" print_mode, the default is
  3423 "A = B" (with priority 50).
  3424 
  3425 * Relations less (<) and less_eq (<=) are also available on type bool.
  3426 Modified syntax to disallow nesting without explicit parentheses,
  3427 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3428 INCOMPATIBILITY.
  3429 
  3430 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3431 
  3432 * Relation composition operator "op O" now has precedence 75 and binds
  3433 stronger than union and intersection. INCOMPATIBILITY.
  3434 
  3435 * The old set interval syntax "{m..n(}" (and relatives) has been
  3436 removed.  Use "{m..<n}" (and relatives) instead.
  3437 
  3438 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3439 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3440 ``declare [[simproc del: neq]]''.
  3441 
  3442 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3443 True/False.
  3444 
  3445 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3446 
  3447 * Theorem setsum_mult renamed to setsum_right_distrib.
  3448 
  3449 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3450 ``rule'' method.
  3451 
  3452 * Reimplemented methods "sat" and "satx", with several improvements:
  3453 goals no longer need to be stated as "<prems> ==> False", equivalences
  3454 (i.e. "=" on type bool) are handled, variable names of the form
  3455 "lit_<n>" are no longer reserved, significant speedup.
  3456 
  3457 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3458 zChaff is still supported as well.
  3459 
  3460 * 'inductive' and 'datatype': provide projections of mutual rules,
  3461 bundled as foo_bar.inducts;
  3462 
  3463 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3464 Library.
  3465 
  3466 * Library: moved theory Accessible_Part to main HOL.
  3467 
  3468 * Library: added theory Coinductive_List of potentially infinite lists
  3469 as greatest fixed-point.
  3470 
  3471 * Library: added theory AssocList which implements (finite) maps as
  3472 association lists.
  3473 
  3474 * Method "evaluation" solves goals (i.e. a boolean expression)
  3475 efficiently by compiling it to ML.  The goal is "proved" (via an
  3476 oracle) if it evaluates to True.
  3477 
  3478 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3479 also when invoked by the simplifier.  This results in the Simplifier
  3480 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3481 Configuration option fast_arith_split_limit=0 recovers the old
  3482 behavior.
  3483 
  3484 * Support for hex (0x20) and binary (0b1001) numerals.
  3485 
  3486 * New method: reify eqs (t), where eqs are equations for an
  3487 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3488 parameter, computes a term s::'b and a list xs::'a list and proves the
  3489 theorem I xs s = t. This is also known as reification or quoting. The
  3490 resulting theorem is applied to the subgoal to substitute t with I xs
  3491 s.  If t is omitted, the subgoal itself is reified.
  3492 
  3493 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3494 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3495 where f is supposed to be a computable function (in the sense of code
  3496 generattion). The method uses reify to compute s and xs as above then
  3497 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3498 r and finally gets the theorem t = r, which is again applied to the
  3499 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3500 
  3501 * Reflection: Automatic reification now handels binding, an example is
  3502 available in src/HOL/ex/ReflectionEx.thy
  3503 
  3504 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3505 command 'statespace' that is similar to 'record', but introduces an
  3506 abstract specification based on the locale infrastructure instead of
  3507 HOL types.  This leads to extra flexibility in composing state spaces,
  3508 in particular multiple inheritance and renaming of components.
  3509 
  3510 
  3511 *** HOL-Complex ***
  3512 
  3513 * Hyperreal: Functions root and sqrt are now defined on negative real
  3514 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3515 Nonnegativity side conditions have been removed from many lemmas, so
  3516 that more subgoals may now be solved by simplification; potential
  3517 INCOMPATIBILITY.
  3518 
  3519 * Real: new type classes formalize real normed vector spaces and
  3520 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3521 and norm :: 'a => real.
  3522 
  3523 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3524 reals into other types. The overloaded constant Reals :: 'a set is now
  3525 defined as range of_real; potential INCOMPATIBILITY.
  3526 
  3527 * Real: proper support for ML code generation, including 'quickcheck'.
  3528 Reals are implemented as arbitrary precision rationals.
  3529 
  3530 * Hyperreal: Several constants that previously worked only for the
  3531 reals have been generalized, so they now work over arbitrary vector
  3532 spaces. Type annotations may need to be added in some cases; potential
  3533 INCOMPATIBILITY.
  3534 
  3535   Infinitesimal  :: ('a::real_normed_vector) star set
  3536   HFinite        :: ('a::real_normed_vector) star set
  3537   HInfinite      :: ('a::real_normed_vector) star set
  3538   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3539   monad          :: ('a::real_normed_vector) star => 'a star set
  3540   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3541   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3542   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3543   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3544   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3545   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3546   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3547   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3548   sgn            :: 'a::real_normed_vector => 'a
  3549   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3550 
  3551 * Complex: Some complex-specific constants are now abbreviations for
  3552 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3553 hnorm.  Other constants have been entirely removed in favor of the
  3554 polymorphic versions (INCOMPATIBILITY):
  3555 
  3556   approx        <-- capprox
  3557   HFinite       <-- CFinite
  3558   HInfinite     <-- CInfinite
  3559   Infinitesimal <-- CInfinitesimal
  3560   monad         <-- cmonad
  3561   galaxy        <-- cgalaxy
  3562   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3563   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3564   (ns)deriv     <-- (ns)cderiv
  3565 
  3566 
  3567 *** HOL-Algebra ***
  3568 
  3569 * Formalisation of ideals and the quotient construction over rings.
  3570 
  3571 * Order and lattice theory no longer based on records.
  3572 INCOMPATIBILITY.
  3573 
  3574 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3575 greatest_closed.  INCOMPATIBILITY.
  3576 
  3577 * Method algebra is now set up via an attribute.  For examples see
  3578 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3579 of algebraic structures.
  3580 
  3581 * Renamed theory CRing to Ring.
  3582 
  3583 
  3584 *** HOL-Nominal ***
  3585 
  3586 * Substantial, yet incomplete support for nominal datatypes (binding
  3587 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3588 src/HOL/Nominal/Examples.  Prospective users should consult
  3589 http://isabelle.in.tum.de/nominal/
  3590 
  3591 
  3592 *** ML ***
  3593 
  3594 * ML basics: just one true type int, which coincides with IntInf.int
  3595 (even on SML/NJ).
  3596 
  3597 * ML within Isar: antiquotations allow to embed statically-checked
  3598 formal entities in the source, referring to the context available at
  3599 compile-time.  For example:
  3600 
  3601 ML {* @{sort "{zero,one}"} *}
  3602 ML {* @{typ "'a => 'b"} *}
  3603 ML {* @{term "%x. x"} *}
  3604 ML {* @{prop "x == y"} *}
  3605 ML {* @{ctyp "'a => 'b"} *}
  3606 ML {* @{cterm "%x. x"} *}
  3607 ML {* @{cprop "x == y"} *}
  3608 ML {* @{thm asm_rl} *}
  3609 ML {* @{thms asm_rl} *}
  3610 ML {* @{type_name c} *}
  3611 ML {* @{type_syntax c} *}
  3612 ML {* @{const_name c} *}
  3613 ML {* @{const_syntax c} *}
  3614 ML {* @{context} *}
  3615 ML {* @{theory} *}
  3616 ML {* @{theory Pure} *}
  3617 ML {* @{theory_ref} *}
  3618 ML {* @{theory_ref Pure} *}
  3619 ML {* @{simpset} *}
  3620 ML {* @{claset} *}
  3621 ML {* @{clasimpset} *}
  3622 
  3623 The same works for sources being ``used'' within an Isar context.
  3624 
  3625 * ML in Isar: improved error reporting; extra verbosity with
  3626 ML_Context.trace enabled.
  3627 
  3628 * Pure/General/table.ML: the join operations now works via exceptions
  3629 DUP/SAME instead of type option. This is simpler in simple cases, and
  3630 admits slightly more efficient complex applications.
  3631 
  3632 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3633 use Context.generic instead of just theory.
  3634 
  3635 * Pure: datatype Context.generic joins theory/Proof.context and
  3636 provides some facilities for code that works in either kind of
  3637 context, notably GenericDataFun for uniform theory and proof data.
  3638 
  3639 * Pure: simplified internal attribute type, which is now always
  3640 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3641 local (Proof.context) attributes have been discontinued, while
  3642 minimizing code duplication. Thm.rule_attribute and
  3643 Thm.declaration_attribute build canonical attributes; see also structure
  3644 Context for further operations on Context.generic, notably
  3645 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3646 declarations and definitions.
  3647 
  3648 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3649 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3650 init only required for impure data. INCOMPATIBILITY: empty really need
  3651 to be empty (no dependencies on theory content!)
  3652 
  3653 * Pure/kernel: consts certification ignores sort constraints given in
  3654 signature declarations. (This information is not relevant to the
  3655 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3656 potential INCOMPATIBILITY.
  3657 
  3658 * Pure: axiomatic type classes are now purely definitional, with
  3659 explicit proofs of class axioms and super class relations performed
  3660 internally. See Pure/axclass.ML for the main internal interfaces --
  3661 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3662 AxClass.axiomatize_class/classrel/arity supersede
  3663 Sign.add_classes/classrel/arities.
  3664 
  3665 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3666 global/local versions on theory vs. Proof.context have been
  3667 discontinued; Attrib.syntax and Method.syntax have been adapted
  3668 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3669 attributes, methods, etc.
  3670 
  3671 * Pure: several functions of signature "... -> theory -> theory * ..."
  3672 have been reoriented to "... -> theory -> ... * theory" in order to
  3673 allow natural usage in combination with the ||>, ||>>, |-> and
  3674 fold_map combinators.
  3675 
  3676 * Pure: official theorem names (closed derivations) and additional
  3677 comments (tags) are now strictly separate.  Name hints -- which are
  3678 maintained as tags -- may be attached any time without affecting the
  3679 derivation.
  3680 
  3681 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3682 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3683 achieve the old behaviour.
  3684 
  3685 * Pure: the "Goal" constant is now called "prop", supporting a
  3686 slightly more general idea of ``protecting'' meta-level rule
  3687 statements.
  3688 
  3689 * Pure: Logic.(un)varify only works in a global context, which is now
  3690 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3691 Logic.legacy_(un)varify as temporary workaround.
  3692 
  3693 * Pure: structure Name provides scalable operations for generating
  3694 internal variable names, notably Name.variants etc.  This replaces
  3695 some popular functions from term.ML:
  3696 
  3697   Term.variant		->  Name.variant
  3698   Term.variantlist	->  Name.variant_list
  3699   Term.invent_names	->  Name.invent_list
  3700 
  3701 Note that low-level renaming rarely occurs in new code -- operations
  3702 from structure Variable are used instead (see below).
  3703 
  3704 * Pure: structure Variable provides fundamental operations for proper
  3705 treatment of fixed/schematic variables in a context.  For example,
  3706 Variable.import introduces fixes for schematics of given facts and
  3707 Variable.export reverses the effect (up to renaming) -- this replaces
  3708 various freeze_thaw operations.
  3709 
  3710 * Pure: structure Goal provides simple interfaces for
  3711 init/conclude/finish and tactical prove operations (replacing former
  3712 Tactic.prove).  Goal.prove is the canonical way to prove results
  3713 within a given context; Goal.prove_global is a degraded version for
  3714 theory level goals, including a global Drule.standard.  Note that
  3715 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3716 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3717 in a locale context).
  3718 
  3719 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3720 and type checking (Syntax.check_term etc.), with common combinations
  3721 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3722 which are considered legacy and await removal.
  3723 
  3724 * Pure/Syntax: generic interfaces for type unchecking
  3725 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3726 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3727 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3728 available for convenience, but refer to the very same operations using
  3729 a mere theory instead of a full context.
  3730 
  3731 * Isar: simplified treatment of user-level errors, using exception
  3732 ERROR of string uniformly.  Function error now merely raises ERROR,
  3733 without any side effect on output channels.  The Isar toplevel takes
  3734 care of proper display of ERROR exceptions.  ML code may use plain
  3735 handle/can/try; cat_error may be used to concatenate errors like this:
  3736 
  3737   ... handle ERROR msg => cat_error msg "..."
  3738 
  3739 Toplevel ML code (run directly or through the Isar toplevel) may be
  3740 embedded into the Isar toplevel with exception display/debug like
  3741 this:
  3742 
  3743   Isar.toplevel (fn () => ...)
  3744 
  3745 INCOMPATIBILITY, removed special transform_error facilities, removed
  3746 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3747 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3748 -- use plain ERROR instead.
  3749 
  3750 * Isar: theory setup now has type (theory -> theory), instead of a
  3751 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3752 
  3753 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3754 ProofContext.debug/verbose flags.
  3755 
  3756 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3757 theory before entering a proof state.  Transactions now always see a
  3758 quasi-functional intermediate checkpoint, both in interactive and
  3759 batch mode.
  3760 
  3761 * Isar: simplified interfaces for outer syntax.  Renamed
  3762 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3763 OuterSyntax.add_parsers -- this functionality is now included in
  3764 OuterSyntax.command etc.  INCOMPATIBILITY.
  3765 
  3766 * Simplifier: the simpset of a running simplification process now
  3767 contains a proof context (cf. Simplifier.the_context), which is the
  3768 very context that the initial simpset has been retrieved from (by
  3769 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3770 (solver, looper etc.) may depend on arbitrary proof data.
  3771 
  3772 * Simplifier.inherit_context inherits the proof context (plus the
  3773 local bounds) of the current simplification process; any simproc
  3774 etc. that calls the Simplifier recursively should do this!  Removed
  3775 former Simplifier.inherit_bounds, which is already included here --
  3776 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3777 specify an explicit context using Simplifier.context/theory_context.
  3778 
  3779 * Simplifier/Classical Reasoner: more abstract interfaces
  3780 change_simpset/claset for modifying the simpset/claset reference of a
  3781 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3782 INCOMPATIBILITY.
  3783 
  3784 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3785 "Trueprop" etc.
  3786 
  3787 
  3788 *** System ***
  3789 
  3790 * settings: the default heap location within ISABELLE_HOME_USER now
  3791 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3792 Isabelle installations.
  3793 
  3794 * isabelle-process: option -S (secure mode) disables some critical
  3795 operations, notably runtime compilation and evaluation of ML source
  3796 code.
  3797 
  3798 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3799 
  3800 * Support for parallel execution, using native multicore support of
  3801 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3802 independent theories, according to the given theory header
  3803 specifications. The maximum number of worker threads is specified via
  3804 usedir option -M or the "max-threads" setting in Proof General. A
  3805 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3806 to 6 on a 8-core machine.  User-code needs to observe certain
  3807 guidelines for thread-safe programming, see appendix A in the Isar
  3808 Implementation manual.
  3809 
  3810 
  3811 
  3812 New in Isabelle2005 (October 2005)
  3813 ----------------------------------
  3814 
  3815 *** General ***
  3816 
  3817 * Theory headers: the new header syntax for Isar theories is
  3818 
  3819   theory <name>
  3820   imports <theory1> ... <theoryN>
  3821   uses <file1> ... <fileM>
  3822   begin
  3823 
  3824 where the 'uses' part is optional.  The previous syntax
  3825 
  3826   theory <name> = <theory1> + ... + <theoryN>:
  3827 
  3828 will disappear in the next release.  Use isatool fixheaders to convert
  3829 existing theory files.  Note that there is no change in ancient
  3830 non-Isar theories now, but these will disappear soon.
  3831 
  3832 * Theory loader: parent theories can now also be referred to via
  3833 relative and absolute paths.
  3834 
  3835 * Command 'find_theorems' searches for a list of criteria instead of a
  3836 list of constants. Known criteria are: intro, elim, dest, name:string,
  3837 simp:term, and any term. Criteria can be preceded by '-' to select
  3838 theorems that do not match. Intro, elim, dest select theorems that
  3839 match the current goal, name:s selects theorems whose fully qualified
  3840 name contain s, and simp:term selects all simplification rules whose
  3841 lhs match term.  Any other term is interpreted as pattern and selects
  3842 all theorems matching the pattern. Available in ProofGeneral under
  3843 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3844 
  3845   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3846 
  3847 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3848 matching the current goal as introduction rule and not having "HOL."
  3849 in their name (i.e. not being defined in theory HOL).
  3850 
  3851 * Command 'thms_containing' has been discontinued in favour of
  3852 'find_theorems'; INCOMPATIBILITY.
  3853 
  3854 * Communication with Proof General is now 8bit clean, which means that
  3855 Unicode text in UTF-8 encoding may be used within theory texts (both
  3856 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3857 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3858 
  3859   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3860   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3861 
  3862 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3863 Classical Reasoner.  Typical big applications run around 2 times
  3864 faster.
  3865 
  3866 
  3867 *** Document preparation ***
  3868 
  3869 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3870 of raw sources.  Only those symbols that do not require additional
  3871 LaTeX packages (depending on comments in isabellesym.sty) are
  3872 displayed properly, everything else is left verbatim.  isatool display
  3873 and isatool print are used as front ends (these are subject to the
  3874 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3875 
  3876 * Command tags control specific markup of certain regions of text,
  3877 notably folding and hiding.  Predefined tags include "theory" (for
  3878 theory begin and end), "proof" for proof commands, and "ML" for
  3879 commands involving ML code; the additional tags "visible" and
  3880 "invisible" are unused by default.  Users may give explicit tag
  3881 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3882 interpretation of tags is determined by the LaTeX job during document
  3883 preparation: see option -V of isatool usedir, or options -n and -t of
  3884 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3885 \isadroptag.
  3886 
  3887 Several document versions may be produced at the same time via isatool
  3888 usedir (the generated index.html will link all of them).  Typical
  3889 specifications include ''-V document=theory,proof,ML'' to present
  3890 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3891 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3892 these parts without any formal replacement text.  The Isabelle site
  3893 default settings produce ''document'' and ''outline'' versions as
  3894 specified above.
  3895 
  3896 * Several new antiquotations:
  3897 
  3898   @{term_type term} prints a term with its type annotated;
  3899 
  3900   @{typeof term} prints the type of a term;
  3901 
  3902   @{const const} is the same as @{term const}, but checks that the
  3903   argument is a known logical constant;
  3904 
  3905   @{term_style style term} and @{thm_style style thm} print a term or
  3906   theorem applying a "style" to it
  3907 
  3908   @{ML text}
  3909 
  3910 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3911 definitions, equations, inequations etc., 'concl' printing only the
  3912 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3913 to print the specified premise.  TermStyle.add_style provides an ML
  3914 interface for introducing further styles.  See also the "LaTeX Sugar"
  3915 document practical applications.  The ML antiquotation prints
  3916 type-checked ML expressions verbatim.
  3917 
  3918 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3919 and 'text' support optional locale specification '(in loc)', which
  3920 specifies the default context for interpreting antiquotations.  For
  3921 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3922 
  3923 * Option 'locale=NAME' of antiquotations specifies an alternative
  3924 context interpreting the subsequent argument.  For example: @{thm
  3925 [locale=lattice] inf_assoc}.
  3926 
  3927 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3928 a proof context.
  3929 
  3930 * Proper output of antiquotations for theory commands involving a
  3931 proof context (such as 'locale' or 'theorem (in loc) ...').
  3932 
  3933 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3934 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3935 
  3936 * isatool usedir: new option -C (default true) controls whether option
  3937 -D should include a copy of the original document directory; -C false
  3938 prevents unwanted effects such as copying of administrative CVS data.
  3939 
  3940 
  3941 *** Pure ***
  3942 
  3943 * Considerably improved version of 'constdefs' command.  Now performs
  3944 automatic type-inference of declared constants; additional support for
  3945 local structure declarations (cf. locales and HOL records), see also
  3946 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3947 sequential dependencies of definitions within a single 'constdefs'
  3948 section; moreover, the declared name needs to be an identifier.  If
  3949 all fails, consider to fall back on 'consts' and 'defs' separately.
  3950 
  3951 * Improved indexed syntax and implicit structures.  First of all,
  3952 indexed syntax provides a notational device for subscripted
  3953 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3954 expressions.  Secondly, in a local context with structure
  3955 declarations, number indexes \<^sub>n or the empty index (default
  3956 number 1) refer to a certain fixed variable implicitly; option
  3957 show_structs controls printing of implicit structures.  Typical
  3958 applications of these concepts involve record types and locales.
  3959 
  3960 * New command 'no_syntax' removes grammar declarations (and
  3961 translations) resulting from the given syntax specification, which is
  3962 interpreted in the same manner as for the 'syntax' command.
  3963 
  3964 * 'Advanced' translation functions (parse_translation etc.) may depend
  3965 on the signature of the theory context being presently used for
  3966 parsing/printing, see also isar-ref manual.
  3967 
  3968 * Improved 'oracle' command provides a type-safe interface to turn an
  3969 ML expression of type theory -> T -> term into a primitive rule of
  3970 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3971 is already included here); see also FOL/ex/IffExample.thy;
  3972 INCOMPATIBILITY.
  3973 
  3974 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3975 before); "cI" is no longer bound, use "c.intro" instead.
  3976 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3977 axclasses vs. locales.
  3978 
  3979 * Improved internal renaming of symbolic identifiers -- attach primes
  3980 instead of base 26 numbers.
  3981 
  3982 * New flag show_question_marks controls printing of leading question
  3983 marks in schematic variable names.
  3984 
  3985 * In schematic variable names, *any* symbol following \<^isub> or
  3986 \<^isup> is now treated as part of the base name.  For example, the
  3987 following works without printing of awkward ".0" indexes:
  3988 
  3989   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3990     by simp
  3991 
  3992 * Inner syntax includes (*(*nested*) comments*).
  3993 
  3994 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3995 annotations as "(00...)".
  3996 
  3997 * Clear separation of logical types and nonterminals, where the latter
  3998 may only occur in 'syntax' specifications or type abbreviations.
  3999 Before that distinction was only partially implemented via type class
  4000 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4001 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4002 exotic syntax specifications may require further adaption
  4003 (e.g. Cube/Cube.thy).
  4004 
  4005 * Removed obsolete type class "logic", use the top sort {} instead.
  4006 Note that non-logical types should be declared as 'nonterminals'
  4007 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4008 specifications.
  4009 
  4010 * Attributes 'induct' and 'cases': type or set names may now be
  4011 locally fixed variables as well.
  4012 
  4013 * Simplifier: can now control the depth to which conditional rewriting
  4014 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4015 Limit.
  4016 
  4017 * Simplifier: simplification procedures may now take the current
  4018 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4019 interface), which is very useful for calling the Simplifier
  4020 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4021 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4022 low-level mk_simproc no longer applies Logic.varify internally, to
  4023 allow for use in a context of fixed variables.
  4024 
  4025 * thin_tac now works even if the assumption being deleted contains !!
  4026 or ==>.  More generally, erule now works even if the major premise of
  4027 the elimination rule contains !! or ==>.
  4028 
  4029 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4030 
  4031 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4032 from Pure, which contains all common declarations already.  Both
  4033 theories are defined via plain Isabelle/Isar .thy files.
  4034 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4035 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4036 use isatool fixcpure to adapt your theory and ML sources.
  4037 
  4038 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4039 selections of theorems in named facts via index ranges.
  4040 
  4041 * 'print_theorems': in theory mode, really print the difference
  4042 wrt. the last state (works for interactive theory development only),
  4043 in proof mode print all local facts (cf. 'print_facts');
  4044 
  4045 * 'hide': option '(open)' hides only base names.
  4046 
  4047 * More efficient treatment of intermediate checkpoints in interactive
  4048 theory development.
  4049 
  4050 * Code generator is now invoked via code_module (incremental code
  4051 generation) and code_library (modular code generation, ML structures
  4052 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4053 must be quoted when used as identifiers.
  4054 
  4055 * New 'value' command for reading, evaluating and printing terms using
  4056 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4057 quoted when used as identifier.
  4058 
  4059 
  4060 *** Locales ***
  4061 
  4062 * New commands for the interpretation of locale expressions in
  4063 theories (1), locales (2) and proof contexts (3).  These generate
  4064 proof obligations from the expression specification.  After the
  4065 obligations have been discharged, theorems of the expression are added
  4066 to the theory, target locale or proof context.  The synopsis of the
  4067 commands is a follows:
  4068 
  4069   (1) interpretation expr inst
  4070   (2) interpretation target < expr
  4071   (3) interpret expr inst
  4072 
  4073 Interpretation in theories and proof contexts require a parameter
  4074 instantiation of terms from the current context.  This is applied to
  4075 specifications and theorems of the interpreted expression.
  4076 Interpretation in locales only permits parameter renaming through the
  4077 locale expression.  Interpretation is smart in that interpretations
  4078 that are active already do not occur in proof obligations, neither are
  4079 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4080 inspect active interpretations of a particular locale.  For details,
  4081 see the Isar Reference manual.  Examples can be found in
  4082 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4083 
  4084 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4085 'interpret' instead.
  4086 
  4087 * New context element 'constrains' for adding type constraints to
  4088 parameters.
  4089 
  4090 * Context expressions: renaming of parameters with syntax
  4091 redeclaration.
  4092 
  4093 * Locale declaration: 'includes' disallowed.
  4094 
  4095 * Proper static binding of attribute syntax -- i.e. types / terms /
  4096 facts mentioned as arguments are always those of the locale definition
  4097 context, independently of the context of later invocations.  Moreover,
  4098 locale operations (renaming and type / term instantiation) are applied
  4099 to attribute arguments as expected.
  4100 
  4101 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4102 actual attributes; rare situations may require Attrib.attribute to
  4103 embed those attributes into Attrib.src that lack concrete syntax.
  4104 Attribute implementations need to cooperate properly with the static
  4105 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4106 Attrib.XXX_thm etc. already do the right thing without further
  4107 intervention.  Only unusual applications -- such as "where" or "of"
  4108 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4109 on the context and the facts involved -- may have to assign parsed
  4110 values to argument tokens explicitly.
  4111 
  4112 * Changed parameter management in theorem generation for long goal
  4113 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4114 theorem statement in rare situations.
  4115 
  4116 * Locale inspection command 'print_locale' omits notes elements.  Use
  4117 'print_locale!' to have them included in the output.
  4118 
  4119 
  4120 *** Provers ***
  4121 
  4122 * Provers/hypsubst.ML: improved version of the subst method, for
  4123 single-step rewriting: it now works in bound variable contexts. New is
  4124 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4125 rewrite a different subterm than the original subst method, which is
  4126 still available as 'simplesubst'.
  4127 
  4128 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4129 and quasi orders.
  4130 
  4131 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4132 reflexive-transitive closure of relations.
  4133 
  4134 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4135 limit (previously hard-coded with a value of 20) user-definable.
  4136 
  4137 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4138 is peformed already.  Object-logics merely need to finish their
  4139 initial simpset configuration as before.  INCOMPATIBILITY.
  4140 
  4141 
  4142 *** HOL ***
  4143 
  4144 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4145 
  4146   syntax (epsilon)
  4147     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4148 
  4149 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4150 and x-symbol; use option '-m epsilon' to get it actually printed.
  4151 Moreover, the mathematically important symbolic identifier \<epsilon>
  4152 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4153 
  4154 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4155 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4156 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4157 support corresponding Isar calculations.
  4158 
  4159 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4160 instead of ":".
  4161 
  4162 * theory SetInterval: changed the syntax for open intervals:
  4163 
  4164   Old       New
  4165   {..n(}    {..<n}
  4166   {)n..}    {n<..}
  4167   {m..n(}   {m..<n}
  4168   {)m..n}   {m<..n}
  4169   {)m..n(}  {m<..<n}
  4170 
  4171 The old syntax is still supported but will disappear in the next
  4172 release.  For conversion use the following Emacs search and replace
  4173 patterns (these are not perfect but work quite well):
  4174 
  4175   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4176   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4177 
  4178 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4179 equalities in commutative rings; method 'algebra' provides a generic
  4180 interface.
  4181 
  4182 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4183 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4184 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4185 be a tuple pattern.
  4186 
  4187 Some new syntax forms are available:
  4188 
  4189   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4190   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4191   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4192   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4193 
  4194 The latter form "\<Sum>x < k. e" used to be based on a separate
  4195 function "Summation", which has been discontinued.
  4196 
  4197 * theory Finite_Set: in structured induction proofs, the insert case
  4198 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4199 (insert F x)'.
  4200 
  4201 * The 'refute' command has been extended to support a much larger
  4202 fragment of HOL, including axiomatic type classes, constdefs and
  4203 typedefs, inductive datatypes and recursion.
  4204 
  4205 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4206 Requires zChaff with proof generation to be installed.  See
  4207 HOL/ex/SAT_Examples.thy for examples.
  4208 
  4209 * Datatype induction via method 'induct' now preserves the name of the
  4210 induction variable. For example, when proving P(xs::'a list) by
  4211 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4212 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4213 in unstructured proof scripts.
  4214 
  4215 * Reworked implementation of records.  Improved scalability for
  4216 records with many fields, avoiding performance problems for type
  4217 inference. Records are no longer composed of nested field types, but
  4218 of nested extension types. Therefore the record type only grows linear
  4219 in the number of extensions and not in the number of fields.  The
  4220 top-level (users) view on records is preserved.  Potential
  4221 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4222 old record representation. The type generated for a record is called
  4223 <record_name>_ext_type.
  4224 
  4225 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4226 proofs triggered by a record definition or a simproc (if
  4227 quick_and_dirty is enabled).  Definitions of large records can take
  4228 quite long.
  4229 
  4230 New simproc record_upd_simproc for simplification of multiple record
  4231 updates enabled by default.  Moreover, trivial updates are also
  4232 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4233 occasionally, since simplification is more powerful by default.
  4234 
  4235 * typedef: proper support for polymorphic sets, which contain extra
  4236 type-variables in the term.
  4237 
  4238 * Simplifier: automatically reasons about transitivity chains
  4239 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4240 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4241 old proofs break occasionally as simplification may now solve more
  4242 goals than previously.
  4243 
  4244 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4245 present.  Works for all partial orders (class "order"), in particular
  4246 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4247 just like y <= x.
  4248 
  4249 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4250 bound variable or a constant then the let is unfolded.  Otherwise
  4251 first a is simplified to b, and then f b is simplified to g. If
  4252 possible we abstract b from g arriving at "let x = b in h x",
  4253 otherwise we unfold the let and arrive at g.  The simproc can be
  4254 enabled/disabled by the reference use_let_simproc.  Potential
  4255 INCOMPATIBILITY since simplification is more powerful by default.
  4256 
  4257 * Classical reasoning: the meson method now accepts theorems as arguments.
  4258 
  4259 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4260 jobs to provide advice on the provability of subgoals.
  4261 
  4262 * Theory OrderedGroup and Ring_and_Field: various additions and
  4263 improvements to faciliate calculations involving equalities and
  4264 inequalities.
  4265 
  4266 The following theorems have been eliminated or modified
  4267 (INCOMPATIBILITY):
  4268 
  4269   abs_eq             now named abs_of_nonneg
  4270   abs_of_ge_0        now named abs_of_nonneg
  4271   abs_minus_eq       now named abs_of_nonpos
  4272   imp_abs_id         now named abs_of_nonneg
  4273   imp_abs_neg_id     now named abs_of_nonpos
  4274   mult_pos           now named mult_pos_pos
  4275   mult_pos_le        now named mult_nonneg_nonneg
  4276   mult_pos_neg_le    now named mult_nonneg_nonpos
  4277   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4278   mult_neg           now named mult_neg_neg
  4279   mult_neg_le        now named mult_nonpos_nonpos
  4280 
  4281 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4282      
  4283      zero_le_square
  4284      not_square_less_zero 
  4285 
  4286   The following lemmas have been deleted from Real/RealPow:
  4287   
  4288      realpow_zero_zero
  4289      realpow_two
  4290      realpow_less
  4291      zero_le_power
  4292      realpow_two_le
  4293      abs_realpow_two
  4294      realpow_two_abs     
  4295 
  4296 * Theory Parity: added rules for simplifying exponents.
  4297 
  4298 * Theory List:
  4299 
  4300 The following theorems have been eliminated or modified
  4301 (INCOMPATIBILITY):
  4302 
  4303   list_all_Nil       now named list_all.simps(1)
  4304   list_all_Cons      now named list_all.simps(2)
  4305   list_all_conv      now named list_all_iff
  4306   set_mem_eq         now named mem_iff
  4307 
  4308 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4309 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4310 
  4311 
  4312 *** HOL-Complex ***
  4313 
  4314 * Theory RealDef: better support for embedding natural numbers and
  4315 integers in the reals.
  4316 
  4317 The following theorems have been eliminated or modified
  4318 (INCOMPATIBILITY):
  4319 
  4320   exp_ge_add_one_self  now requires no hypotheses
  4321   real_of_int_add      reversed direction of equality (use [symmetric])
  4322   real_of_int_minus    reversed direction of equality (use [symmetric])
  4323   real_of_int_diff     reversed direction of equality (use [symmetric])
  4324   real_of_int_mult     reversed direction of equality (use [symmetric])
  4325 
  4326 * Theory RComplete: expanded support for floor and ceiling functions.
  4327 
  4328 * Theory Ln is new, with properties of the natural logarithm
  4329 
  4330 * Hyperreal: There is a new type constructor "star" for making
  4331 nonstandard types.  The old type names are now type synonyms:
  4332 
  4333   hypreal = real star
  4334   hypnat = nat star
  4335   hcomplex = complex star
  4336 
  4337 * Hyperreal: Many groups of similarly-defined constants have been
  4338 replaced by polymorphic versions (INCOMPATIBILITY):
  4339 
  4340   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4341 
  4342   starset      <-- starsetNat, starsetC
  4343   *s*          <-- *sNat*, *sc*
  4344   starset_n    <-- starsetNat_n, starsetC_n
  4345   *sn*         <-- *sNatn*, *scn*
  4346   InternalSets <-- InternalNatSets, InternalCSets
  4347 
  4348   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4349   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4350   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4351   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4352   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4353 
  4354 * Hyperreal: Many type-specific theorems have been removed in favor of
  4355 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4356 
  4357   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4358   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4359   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4360   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4361   right_minus <-- hypreal_add_minus
  4362   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4363   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4364   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4365   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4366   mult_1_right <-- hcomplex_mult_one_right
  4367   mult_zero_left <-- hcomplex_mult_zero_left
  4368   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4369   right_distrib <-- hypnat_add_mult_distrib2
  4370   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4371   right_inverse <-- hypreal_mult_inverse
  4372   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4373   order_refl <-- {hypreal,hypnat}_le_refl
  4374   order_trans <-- {hypreal,hypnat}_le_trans
  4375   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4376   order_less_le <-- {hypreal,hypnat}_less_le
  4377   linorder_linear <-- {hypreal,hypnat}_le_linear
  4378   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4379   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4380   add_nonneg_nonneg <-- hypreal_le_add_order
  4381 
  4382 * Hyperreal: Separate theorems having to do with type-specific
  4383 versions of constants have been merged into theorems that apply to the
  4384 new polymorphic constants (INCOMPATIBILITY):
  4385 
  4386   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4387   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4388   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4389   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4390   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4391   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4392   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4393   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4394   STAR_diff <-- {STAR,STARC}_diff
  4395   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4396     STARC_hcomplex_of_complex}_image_subset
  4397   starset_n_Un <-- starset{Nat,C}_n_Un
  4398   starset_n_Int <-- starset{Nat,C}_n_Int
  4399   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4400   starset_n_diff <-- starset{Nat,C}_n_diff
  4401   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4402   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4403   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4404   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4405   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4406   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4407   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4408   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4409   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4410   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4411   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4412   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4413   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4414   starfun_diff <-- starfun{C,RC,CR}_diff
  4415   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4416   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4417   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4418   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4419   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4420   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4421   starfun_Id <-- starfunC_Id
  4422   starfun_approx <-- starfun{Nat,CR}_approx
  4423   starfun_capprox <-- starfun{C,RC}_capprox
  4424   starfun_abs <-- starfunNat_rabs
  4425   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4426   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4427   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4428   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4429   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4430   starfun_add_approx <-- starfunCR_add_approx
  4431   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4432   starfun_divide <-- starfun{C,CR,RC}_divide
  4433   starfun_n <-- starfun{Nat,C}_n
  4434   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4435   starfun_n_add <-- starfun{Nat,C}_n_add
  4436   starfun_n_add_minus <-- starfunNat_n_add_minus
  4437   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4438   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4439   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4440 
  4441   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4442   star_n_minus <-- {hypreal,hcomplex}_minus
  4443   star_n_diff <-- {hypreal,hcomplex}_diff
  4444   star_n_mult <-- {hypreal,hcomplex}_mult
  4445   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4446   star_n_le <-- {hypreal,hypnat}_le
  4447   star_n_less <-- {hypreal,hypnat}_less
  4448   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4449   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4450   star_n_abs <-- hypreal_hrabs
  4451   star_n_divide <-- hcomplex_divide
  4452 
  4453   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4454   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4455   star_of_diff <-- hypreal_of_real_diff
  4456   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4457   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4458   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4459   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4460   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4461   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4462   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4463   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4464   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4465   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4466   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4467   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4468   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4469   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4470   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4471   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4472   star_of_power <-- hypreal_of_real_power
  4473   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4474 
  4475 * Hyperreal: new method "transfer" that implements the transfer
  4476 principle of nonstandard analysis. With a subgoal that mentions
  4477 nonstandard types like "'a star", the command "apply transfer"
  4478 replaces it with an equivalent one that mentions only standard types.
  4479 To be successful, all free variables must have standard types; non-
  4480 standard variables must have explicit universal quantifiers.
  4481 
  4482 * Hyperreal: A theory of Taylor series.
  4483 
  4484 
  4485 *** HOLCF ***
  4486 
  4487 * Discontinued special version of 'constdefs' (which used to support
  4488 continuous functions) in favor of the general Pure one with full
  4489 type-inference.
  4490 
  4491 * New simplification procedure for solving continuity conditions; it
  4492 is much faster on terms with many nested lambda abstractions (cubic
  4493 instead of exponential time).
  4494 
  4495 * New syntax for domain package: selector names are now optional.
  4496 Parentheses should be omitted unless argument is lazy, for example:
  4497 
  4498   domain 'a stream = cons "'a" (lazy "'a stream")
  4499 
  4500 * New command 'fixrec' for defining recursive functions with pattern
  4501 matching; defining multiple functions with mutual recursion is also
  4502 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4503 sinr, or any data constructor defined by the domain package. The given
  4504 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4505 syntax and examples.
  4506 
  4507 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4508 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4509 but the proof obligation additionally includes an admissibility
  4510 requirement. The packages generate instances of class cpo or pcpo,
  4511 with continuity and strictness theorems for Rep and Abs.
  4512 
  4513 * HOLCF: Many theorems have been renamed according to a more standard naming
  4514 scheme (INCOMPATIBILITY):
  4515 
  4516   foo_inject:  "foo$x = foo$y ==> x = y"
  4517   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4518   foo_less:    "(foo$x << foo$y) = (x << y)"
  4519   foo_strict:  "foo$UU = UU"
  4520   foo_defined: "... ==> foo$x ~= UU"
  4521   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4522 
  4523 
  4524 *** ZF ***
  4525 
  4526 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4527 including the First Isomorphism Theorem (on quotienting by the kernel
  4528 of a homomorphism).
  4529 
  4530 * ZF/Simplifier: install second copy of type solver that actually
  4531 makes use of TC rules declared to Isar proof contexts (or locales);
  4532 the old version is still required for ML proof scripts.
  4533 
  4534 
  4535 *** Cube ***
  4536 
  4537 * Converted to Isar theory format; use locales instead of axiomatic
  4538 theories.
  4539 
  4540 
  4541 *** ML ***
  4542 
  4543 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4544 for ||>, ||>>, |>>,
  4545 
  4546 * Pure/library.ML no longer defines its own option datatype, but uses
  4547 that of the SML basis, which has constructors NONE and SOME instead of
  4548 None and Some, as well as exception Option.Option instead of OPTION.
  4549 The functions the, if_none, is_some, is_none have been adapted
  4550 accordingly, while Option.map replaces apsome.
  4551 
  4552 * Pure/library.ML: the exception LIST has been given up in favour of
  4553 the standard exceptions Empty and Subscript, as well as
  4554 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4555 superceded by the standard hd and tl functions etc.
  4556 
  4557 A number of basic list functions are no longer exported to the ML
  4558 toplevel, as they are variants of predefined functions.  The following
  4559 suggests how one can translate existing code:
  4560 
  4561     rev_append xs ys = List.revAppend (xs, ys)
  4562     nth_elem (i, xs) = List.nth (xs, i)
  4563     last_elem xs = List.last xs
  4564     flat xss = List.concat xss
  4565     seq fs = List.app fs
  4566     partition P xs = List.partition P xs
  4567     mapfilter f xs = List.mapPartial f xs
  4568 
  4569 * Pure/library.ML: several combinators for linear functional
  4570 transformations, notably reverse application and composition:
  4571 
  4572   x |> f                f #> g
  4573   (x, y) |-> f          f #-> g
  4574 
  4575 * Pure/library.ML: introduced/changed precedence of infix operators:
  4576 
  4577   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4578   infix 2 ?;
  4579   infix 3 o oo ooo oooo;
  4580   infix 4 ~~ upto downto;
  4581 
  4582 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4583 infix operators.
  4584 
  4585 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4586 fold_map support linear functional transformations and nesting.  For
  4587 example:
  4588 
  4589   fold f [x1, ..., xN] y =
  4590     y |> f x1 |> ... |> f xN
  4591 
  4592   (fold o fold) f [xs1, ..., xsN] y =
  4593     y |> fold f xs1 |> ... |> fold f xsN
  4594 
  4595   fold f [x1, ..., xN] =
  4596     f x1 #> ... #> f xN
  4597 
  4598   (fold o fold) f [xs1, ..., xsN] =
  4599     fold f xs1 #> ... #> fold f xsN
  4600 
  4601 * Pure/library.ML: the following selectors on type 'a option are
  4602 available:
  4603 
  4604   the:               'a option -> 'a  (*partial*)
  4605   these:             'a option -> 'a  where 'a = 'b list
  4606   the_default: 'a -> 'a option -> 'a
  4607   the_list:          'a option -> 'a list
  4608 
  4609 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4610 basic operations for association lists, following natural argument
  4611 order; moreover the explicit equality predicate passed here avoids
  4612 potentially expensive polymorphic runtime equality checks.
  4613 The old functions may be expressed as follows:
  4614 
  4615   assoc = uncurry (AList.lookup (op =))
  4616   assocs = these oo AList.lookup (op =)
  4617   overwrite = uncurry (AList.update (op =)) o swap
  4618 
  4619 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4620 
  4621   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4622   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4623 
  4624 replacing make_keylist and keyfilter (occassionally used)
  4625 Naive rewrites:
  4626 
  4627   make_keylist = AList.make
  4628   keyfilter = AList.find (op =)
  4629 
  4630 * eq_fst and eq_snd now take explicit equality parameter, thus
  4631   avoiding eqtypes. Naive rewrites:
  4632 
  4633     eq_fst = eq_fst (op =)
  4634     eq_snd = eq_snd (op =)
  4635 
  4636 * Removed deprecated apl and apr (rarely used).
  4637   Naive rewrites:
  4638 
  4639     apl (n, op) =>>= curry op n
  4640     apr (op, m) =>>= fn n => op (n, m)
  4641 
  4642 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4643 provides a reasonably efficient light-weight implementation of sets as
  4644 lists.
  4645 
  4646 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4647 few new operations; existing lookup and update are now curried to
  4648 follow natural argument order (for use with fold etc.);
  4649 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4650 
  4651 * Pure/General: output via the Isabelle channels of
  4652 writeln/warning/error etc. is now passed through Output.output, with a
  4653 hook for arbitrary transformations depending on the print_mode
  4654 (cf. Output.add_mode -- the first active mode that provides a output
  4655 function wins).  Already formatted output may be embedded into further
  4656 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4657 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4658 accommodate easy composition of diagnostic messages etc.  Programmers
  4659 rarely need to care about Output.output or Output.raw at all, with
  4660 some notable exceptions: Output.output is required when bypassing the
  4661 standard channels (writeln etc.), or in token translations to produce
  4662 properly formatted results; Output.raw is required when capturing
  4663 already output material that will eventually be presented to the user
  4664 a second time.  For the default print mode, both Output.output and
  4665 Output.raw have no effect.
  4666 
  4667 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4668 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4669 cumulative results are displayed at the end of a batch session.
  4670 
  4671 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4672 replaced by File.platform_path and File.shell_path (with appropriate
  4673 hooks).  This provides a clean interface for unusual systems where the
  4674 internal and external process view of file names are different.
  4675 
  4676 * Pure: more efficient orders for basic syntactic entities: added
  4677 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4678 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4679 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4680 orders now -- potential INCOMPATIBILITY for code that depends on a
  4681 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4682 Library.sort_strings on result).
  4683 
  4684 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4685 fold_types traverse types/terms from left to right, observing natural
  4686 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4687 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4688 
  4689 * Pure: name spaces have been refined, with significant changes of the
  4690 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4691 to extern(_table).  The plain name entry path is superceded by a
  4692 general 'naming' context, which also includes the 'policy' to produce
  4693 a fully qualified name and external accesses of a fully qualified
  4694 name; NameSpace.extend is superceded by context dependent
  4695 Sign.declare_name.  Several theory and proof context operations modify
  4696 the naming context.  Especially note Theory.restore_naming and
  4697 ProofContext.restore_naming to get back to a sane state; note that
  4698 Theory.add_path is no longer sufficient to recover from
  4699 Theory.absolute_path in particular.
  4700 
  4701 * Pure: new flags short_names (default false) and unique_names
  4702 (default true) for controlling output of qualified names.  If
  4703 short_names is set, names are printed unqualified.  If unique_names is
  4704 reset, the name prefix is reduced to the minimum required to achieve
  4705 the original result when interning again, even if there is an overlap
  4706 with earlier declarations.
  4707 
  4708 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4709 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4710 (useful for printing error messages).  INCOMPATIBILITY.
  4711 
  4712 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4713 Theory.theory are now identified, referring to the universal
  4714 Context.theory (see Pure/context.ML).  Actual signature and theory
  4715 content is managed as theory data.  The old code and interfaces were
  4716 spread over many files and structures; the new arrangement introduces
  4717 considerable INCOMPATIBILITY to gain more clarity:
  4718 
  4719   Context -- theory management operations (name, identity, inclusion,
  4720     parents, ancestors, merge, etc.), plus generic theory data;
  4721 
  4722   Sign -- logical signature and syntax operations (declaring consts,
  4723     types, etc.), plus certify/read for common entities;
  4724 
  4725   Theory -- logical theory operations (stating axioms, definitions,
  4726     oracles), plus a copy of logical signature operations (consts,
  4727     types, etc.); also a few basic management operations (Theory.copy,
  4728     Theory.merge, etc.)
  4729 
  4730 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4731 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4732 for convenience -- they merely return the theory.
  4733 
  4734 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4735 
  4736 * Pure: the Isar proof context type is already defined early in Pure
  4737 as Context.proof (note that ProofContext.context and Proof.context are
  4738 aliases, where the latter is the preferred name).  This enables other
  4739 Isabelle components to refer to that type even before Isar is present.
  4740 
  4741 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4742 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4743 any of these kinds.  For example, Sign.intern typeK is now
  4744 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4745 Theory.hide_types.  Also note that former
  4746 Theory.hide_classes/types/consts are now
  4747 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4748 internalize their arguments!  INCOMPATIBILITY.
  4749 
  4750 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4751 datatype thmref (with constructors Name and NameSelection) instead of
  4752 plain string -- INCOMPATIBILITY;
  4753 
  4754 * Pure: cases produced by proof methods specify options, where NONE
  4755 means to remove case bindings -- INCOMPATIBILITY in
  4756 (RAW_)METHOD_CASES.
  4757 
  4758 * Pure: the following operations retrieve axioms or theorems from a
  4759 theory node or theory hierarchy, respectively:
  4760 
  4761   Theory.axioms_of: theory -> (string * term) list
  4762   Theory.all_axioms_of: theory -> (string * term) list
  4763   PureThy.thms_of: theory -> (string * thm) list
  4764   PureThy.all_thms_of: theory -> (string * thm) list
  4765 
  4766 * Pure: print_tac now outputs the goal through the trace channel.
  4767 
  4768 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4769 Reference Toplevel.debug (default false) controls detailed printing
  4770 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4771 controls execution profiling -- set to 1 for time and 2 for space
  4772 (both increase the runtime).
  4773 
  4774 * Isar session: The initial use of ROOT.ML is now always timed,
  4775 i.e. the log will show the actual process times, in contrast to the
  4776 elapsed wall-clock time that the outer shell wrapper produces.
  4777 
  4778 * Simplifier: improved handling of bound variables (nameless
  4779 representation, avoid allocating new strings).  Simprocs that invoke
  4780 the Simplifier recursively should use Simplifier.inherit_bounds to
  4781 avoid local name clashes.  Failure to do so produces warnings
  4782 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4783 for further details.
  4784 
  4785 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4786 bindings for all theorems stored within a given theory; this may help
  4787 in porting non-Isar theories to Isar ones, while keeping ML proof
  4788 scripts for the time being.
  4789 
  4790 * ML operator HTML.with_charset specifies the charset begin used for
  4791 generated HTML files.  For example:
  4792 
  4793   HTML.with_charset "utf-8" use_thy "Hebrew";
  4794   HTML.with_charset "utf-8" use_thy "Chinese";
  4795 
  4796 
  4797 *** System ***
  4798 
  4799 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4800 isabelle, isatool etc.).
  4801 
  4802 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4803 isatool doc, isatool mkdir, display_drafts etc.).
  4804 
  4805 * isatool usedir: option -f allows specification of the ML file to be
  4806 used by Isabelle; default is ROOT.ML.
  4807 
  4808 * New isatool version outputs the version identifier of the Isabelle
  4809 distribution being used.
  4810 
  4811 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4812 (containing Boolean satisfiability problems) into Isabelle/HOL
  4813 theories.
  4814 
  4815 
  4816 
  4817 New in Isabelle2004 (April 2004)
  4818 --------------------------------
  4819 
  4820 *** General ***
  4821 
  4822 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4823   Replaces linorder.ML.
  4824 
  4825 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4826   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4827   (\<a>...\<z>), are now considered normal letters, and can therefore
  4828   be used anywhere where an ASCII letter (a...zA...Z) has until
  4829   now. COMPATIBILITY: This obviously changes the parsing of some
  4830   terms, especially where a symbol has been used as a binder, say
  4831   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4832   as an identifier.  Fix it by inserting a space around former
  4833   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4834   existing theory and ML files.
  4835 
  4836 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4837 
  4838 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4839   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4840   a normal (but invisible) letter. For multiple letter subscripts repeat
  4841   \<^isub> like this: x\<^isub>1\<^isub>2.
  4842 
  4843 * Pure: There are now sub-/superscripts that can span more than one
  4844   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4845   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4846   superscript. The new control characters are not identifier parts.
  4847 
  4848 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4849   content of "..." to the latex file instead of \isacntrl... . The "..."
  4850   may consist of any printable characters excluding the end bracket >.
  4851 
  4852 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4853   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4854   declare constants "final", which prevents their being given a definition
  4855   later.  It is useful for constants whose behaviour is fixed axiomatically
  4856   rather than definitionally, such as the meta-logic connectives.
  4857 
  4858 * Pure: 'instance' now handles general arities with general sorts
  4859   (i.e. intersections of classes),
  4860 
  4861 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4862   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4863   It can be changed to alter the colors/layout of generated pages.
  4864 
  4865 
  4866 *** Isar ***
  4867 
  4868 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4869   cut_tac, subgoal_tac and thin_tac:
  4870   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4871     locales are no longer forced to write Isar proof scripts.
  4872     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4873     emulations.
  4874   - INCOMPATIBILITY: names of variables to be instantiated may no
  4875     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4876     This is consistent with the instantiation attribute "where".
  4877 
  4878 * Attributes "where" and "of":
  4879   - Now take type variables of instantiated theorem into account when reading
  4880     the instantiation string.  This fixes a bug that caused instantiated
  4881     theorems to have too special types in some circumstances.
  4882   - "where" permits explicit instantiations of type variables.
  4883 
  4884 * Calculation commands "moreover" and "also" no longer interfere with
  4885   current facts ("this"), admitting arbitrary combinations with "then"
  4886   and derived forms.
  4887 
  4888 * Locales:
  4889   - Goal statements involving the context element "includes" no longer
  4890     generate theorems with internal delta predicates (those ending on
  4891     "_axioms") in the premise.
  4892     Resolve particular premise with <locale>.intro to obtain old form.
  4893   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4894     specification and "includes" elements in goal statement.
  4895   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4896     [intro?] and [elim?] (respectively) by default.
  4897   - Experimental command for instantiation of locales in proof contexts:
  4898         instantiate <label>[<attrs>]: <loc>
  4899     Instantiates locale <loc> and adds all its theorems to the current context
  4900     taking into account their attributes.  Label and attrs are optional
  4901     modifiers, like in theorem declarations.  If present, names of
  4902     instantiated theorems are qualified with <label>, and the attributes
  4903     <attrs> are applied after any attributes these theorems might have already.
  4904       If the locale has assumptions, a chained fact of the form
  4905     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4906     are derived.  The command does not support old-style locales declared
  4907     with "locale (open)".
  4908       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4909 
  4910 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4911   (Isar) contexts.
  4912 
  4913 
  4914 *** HOL ***
  4915 
  4916 * Proof import: new image HOL4 contains the imported library from
  4917   the HOL4 system with about 2500 theorems. It is imported by
  4918   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4919   can be used like any other Isabelle image.  See
  4920   HOL/Import/HOL/README for more information.
  4921 
  4922 * Simplifier:
  4923   - Much improved handling of linear and partial orders.
  4924     Reasoners for linear and partial orders are set up for type classes
  4925     "linorder" and "order" respectively, and are added to the default simpset
  4926     as solvers.  This means that the simplifier can build transitivity chains
  4927     to solve goals from the assumptions.
  4928   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4929     of blast or auto after simplification become unnecessary because the goal
  4930     is solved by simplification already.
  4931 
  4932 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4933     all proved in axiomatic type classes for semirings, rings and fields.
  4934 
  4935 * Numerics:
  4936   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4937     now formalized using the Ring_and_Field theory mentioned above.
  4938   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4939     than before, because now they are set up once in a generic manner.
  4940   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4941     Look for the general versions in Ring_and_Field (and Power if they concern
  4942     exponentiation).
  4943 
  4944 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4945 
  4946 * Records:
  4947   - Record types are now by default printed with their type abbreviation
  4948     instead of the list of all field types. This can be configured via
  4949     the reference "print_record_type_abbr".
  4950   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4951     (not enabled by default).
  4952   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4953     EX x. x = sel r to True (not enabled by default).
  4954   - Tactic "record_split_simp_tac" to split and simplify records added.
  4955 
  4956 * 'specification' command added, allowing for definition by
  4957   specification.  There is also an 'ax_specification' command that
  4958   introduces the new constants axiomatically.
  4959 
  4960 * arith(_tac) is now able to generate counterexamples for reals as well.
  4961 
  4962 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4963 
  4964 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4965   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4966 
  4967 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4968   matrix theory to linear programming.
  4969 
  4970 * Unions and Intersections:
  4971   The latex output syntax of UN and INT has been changed
  4972   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4973   i.e. the index formulae has become a subscript.
  4974   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4975 
  4976 * Unions and Intersections over Intervals:
  4977   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4978   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4979   like in normal math, and corresponding versions for < and for intersection.
  4980 
  4981 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4982   lexicographic dictonary ordering has been added as "lexord".
  4983 
  4984 * ML: the legacy theory structures Int and List have been removed. They had
  4985   conflicted with ML Basis Library structures having the same names.
  4986 
  4987 * 'refute' command added to search for (finite) countermodels.  Only works
  4988   for a fragment of HOL.  The installation of an external SAT solver is
  4989   highly recommended.  See "HOL/Refute.thy" for details.
  4990 
  4991 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4992   formulae under an assignment of free variables to random values.
  4993   In contrast to 'refute', it can deal with inductive datatypes,
  4994   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4995   for examples.
  4996 
  4997 
  4998 *** HOLCF ***
  4999 
  5000 * Streams now come with concatenation and are part of the HOLCF image
  5001 
  5002 
  5003 
  5004 New in Isabelle2003 (May 2003)
  5005 ------------------------------
  5006 
  5007 *** General ***
  5008 
  5009 * Provers/simplifier:
  5010 
  5011   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5012     Assumptions are now subject to complete mutual simplification,
  5013     not just from left to right. The simplifier now preserves
  5014     the order of assumptions.
  5015 
  5016     Potential INCOMPATIBILITY:
  5017 
  5018     -- simp sometimes diverges where the old version did
  5019        not, e.g. invoking simp on the goal
  5020 
  5021         [| P (f x); y = x; f x = f y |] ==> Q
  5022 
  5023        now gives rise to the infinite reduction sequence
  5024 
  5025         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5026 
  5027        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5028        kind of problem.
  5029 
  5030     -- Tactics combining classical reasoner and simplification (such as auto)
  5031        are also affected by this change, because many of them rely on
  5032        simp. They may sometimes diverge as well or yield a different numbers
  5033        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5034        in case of problems. Sometimes subsequent calls to the classical
  5035        reasoner will fail because a preceeding call to the simplifier too
  5036        eagerly simplified the goal, e.g. deleted redundant premises.
  5037 
  5038   - The simplifier trace now shows the names of the applied rewrite rules
  5039 
  5040   - You can limit the number of recursive invocations of the simplifier
  5041     during conditional rewriting (where the simplifie tries to solve the
  5042     conditions before applying the rewrite rule):
  5043     ML "simp_depth_limit := n"
  5044     where n is an integer. Thus you can force termination where previously
  5045     the simplifier would diverge.
  5046 
  5047   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5048 
  5049   - No longer aborts on failed congruence proof.  Instead, the
  5050     congruence is ignored.
  5051 
  5052 * Pure: New generic framework for extracting programs from constructive
  5053   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5054   as HOL/Extraction for some case studies.
  5055 
  5056 * Pure: The main goal of the proof state is no longer shown by default, only
  5057 the subgoals. This behaviour is controlled by a new flag.
  5058    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5059 (ML: Proof.show_main_goal).
  5060 
  5061 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5062 rules whose conclusion matches subgoal 1:
  5063       PG menu: Isabelle/Isar -> Show me -> matching rules
  5064 The rules are ordered by how closely they match the subgoal.
  5065 In particular, rules that solve a subgoal outright are displayed first
  5066 (or rather last, the way they are printed).
  5067 (ML: ProofGeneral.print_intros())
  5068 
  5069 * Pure: New flag trace_unify_fail causes unification to print
  5070 diagnostic information (PG: in trace buffer) when it fails. This is
  5071 useful for figuring out why single step proofs like rule, erule or
  5072 assumption failed.
  5073 
  5074 * Pure: Locale specifications now produce predicate definitions
  5075 according to the body of text (covering assumptions modulo local
  5076 definitions); predicate "loc_axioms" covers newly introduced text,
  5077 while "loc" is cumulative wrt. all included locale expressions; the
  5078 latter view is presented only on export into the global theory
  5079 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5080 on the old view without predicates;
  5081 
  5082 * Pure: predefined locales "var" and "struct" are useful for sharing
  5083 parameters (as in CASL, for example); just specify something like
  5084 ``var x + var y + struct M'' as import;
  5085 
  5086 * Pure: improved thms_containing: proper indexing of facts instead of
  5087 raw theorems; check validity of results wrt. current name space;
  5088 include local facts of proof configuration (also covers active
  5089 locales), cover fixed variables in index; may use "_" in term
  5090 specification; an optional limit for the number of printed facts may
  5091 be given (the default is 40);
  5092 
  5093 * Pure: disallow duplicate fact bindings within new-style theory files
  5094 (batch-mode only);
  5095 
  5096 * Provers: improved induct method: assumptions introduced by case
  5097 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5098 the goal statement); "foo" still refers to all facts collectively;
  5099 
  5100 * Provers: the function blast.overloaded has been removed: all constants
  5101 are regarded as potentially overloaded, which improves robustness in exchange
  5102 for slight decrease in efficiency;
  5103 
  5104 * Provers/linorder: New generic prover for transitivity reasoning over
  5105 linear orders.  Note: this prover is not efficient!
  5106 
  5107 * Isar: preview of problems to finish 'show' now produce an error
  5108 rather than just a warning (in interactive mode);
  5109 
  5110 
  5111 *** HOL ***
  5112 
  5113 * arith(_tac)
  5114 
  5115  - Produces a counter example if it cannot prove a goal.
  5116    Note that the counter example may be spurious if the goal is not a formula
  5117    of quantifier-free linear arithmetic.
  5118    In ProofGeneral the counter example appears in the trace buffer.
  5119 
  5120  - Knows about div k and mod k where k is a numeral of type nat or int.
  5121 
  5122  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5123    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5124    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5125 
  5126 * simp's arithmetic capabilities have been enhanced a bit: it now
  5127 takes ~= in premises into account (by performing a case split);
  5128 
  5129 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5130 are distributed over a sum of terms;
  5131 
  5132 * New tactic "trans_tac" and method "trans" instantiate
  5133 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5134 "<=", "<" and "=").
  5135 
  5136 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5137 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5138 
  5139 * 'typedef' command has new option "open" to suppress the set
  5140 definition;
  5141 
  5142 * functions Min and Max on finite sets have been introduced (theory
  5143 Finite_Set);
  5144 
  5145 * attribute [symmetric] now works for relations as well; it turns
  5146 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5147 
  5148 * induct over a !!-quantified statement (say !!x1..xn):
  5149   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5150 
  5151 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5152 %x. None. Warning: empty_def now refers to the previously hidden definition
  5153 of the empty set.
  5154 
  5155 * Algebra: formalization of classical algebra.  Intended as base for
  5156 any algebraic development in Isabelle.  Currently covers group theory
  5157 (up to Sylow's theorem) and ring theory (Universal Property of
  5158 Univariate Polynomials).  Contributions welcome;
  5159 
  5160 * GroupTheory: deleted, since its material has been moved to Algebra;
  5161 
  5162 * Complex: new directory of the complex numbers with numeric constants,
  5163 nonstandard complex numbers, and some complex analysis, standard and
  5164 nonstandard (Jacques Fleuriot);
  5165 
  5166 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5167 
  5168 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5169 Fleuriot);
  5170 
  5171 * Real/HahnBanach: updated and adapted to locales;
  5172 
  5173 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5174 Gray and Kramer);
  5175 
  5176 * UNITY: added the Meier-Sanders theory of progress sets;
  5177 
  5178 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5179 as abstract algorithms, instantiated to the JVM;
  5180 
  5181 * Bali: Java source language formalization. Type system, operational
  5182 semantics, axiomatic semantics. Supported language features:
  5183 classes, interfaces, objects,virtual methods, static methods,
  5184 static/instance fields, arrays, access modifiers, definite
  5185 assignment, exceptions.
  5186 
  5187 
  5188 *** ZF ***
  5189 
  5190 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5191 universe, etc.);
  5192 
  5193 * Main ZF: virtually all theories converted to new-style format;
  5194 
  5195 
  5196 *** ML ***
  5197 
  5198 * Pure: Tactic.prove provides sane interface for internal proofs;
  5199 omits the infamous "standard" operation, so this is more appropriate
  5200 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5201 
  5202 * Pure: improved error reporting of simprocs;
  5203 
  5204 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5205 up simprocs;
  5206 
  5207 
  5208 *** Document preparation ***
  5209 
  5210 * uses \par instead of \\ for line breaks in theory text. This may
  5211 shift some page breaks in large documents. To get the old behaviour
  5212 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5213 
  5214 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5215 other packages
  5216 
  5217 * \<euro> now needs package babel/greek instead of marvosym (which
  5218 broke \Rightarrow)
  5219 
  5220 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5221 textcomp package)
  5222 
  5223 
  5224 
  5225 New in Isabelle2002 (March 2002)
  5226 --------------------------------
  5227 
  5228 *** Document preparation ***
  5229 
  5230 * greatly simplified document preparation setup, including more
  5231 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5232 instructive isatool mkdir; users should basically be able to get
  5233 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5234 users may run a separate document processing stage manually like this:
  5235 "isatool usedir -D output HOL Test && isatool document Test/output";
  5236 
  5237 * theory dependency graph may now be incorporated into documents;
  5238 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5239 with \includegraphics of LaTeX;
  5240 
  5241 * proper spacing of consecutive markup elements, especially text
  5242 blocks after section headings;
  5243 
  5244 * support bold style (for single symbols only), input syntax is like
  5245 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5246 
  5247 * \<bullet> is now output as bold \cdot by default, which looks much
  5248 better in printed text;
  5249 
  5250 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5251 note that these symbols are currently unavailable in Proof General /
  5252 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5253 
  5254 * isatool latex no longer depends on changed TEXINPUTS, instead
  5255 isatool document copies the Isabelle style files to the target
  5256 location;
  5257 
  5258 
  5259 *** Isar ***
  5260 
  5261 * Pure/Provers: improved proof by cases and induction;
  5262   - 'case' command admits impromptu naming of parameters (such as
  5263     "case (Suc n)");
  5264   - 'induct' method divinates rule instantiation from the inductive
  5265     claim; no longer requires excessive ?P bindings for proper
  5266     instantiation of cases;
  5267   - 'induct' method properly enumerates all possibilities of set/type
  5268     rules; as a consequence facts may be also passed through *type*
  5269     rules without further ado;
  5270   - 'induct' method now derives symbolic cases from the *rulified*
  5271     rule (before it used to rulify cases stemming from the internal
  5272     atomized version); this means that the context of a non-atomic
  5273     statement becomes is included in the hypothesis, avoiding the
  5274     slightly cumbersome show "PROP ?case" form;
  5275   - 'induct' may now use elim-style induction rules without chaining
  5276     facts, using ``missing'' premises from the goal state; this allows
  5277     rules stemming from inductive sets to be applied in unstructured
  5278     scripts, while still benefitting from proper handling of non-atomic
  5279     statements; NB: major inductive premises need to be put first, all
  5280     the rest of the goal is passed through the induction;
  5281   - 'induct' proper support for mutual induction involving non-atomic
  5282     rule statements (uses the new concept of simultaneous goals, see
  5283     below);
  5284   - append all possible rule selections, but only use the first
  5285     success (no backtracking);
  5286   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5287   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5288   - added 'print_induct_rules' (covered by help item in recent Proof
  5289     General versions);
  5290   - moved induct/cases attributes to Pure, methods to Provers;
  5291   - generic method setup instantiated for FOL and HOL;
  5292 
  5293 * Pure: support multiple simultaneous goal statements, for example
  5294 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5295 meta-level mechanism, this acts as if several individual goals had
  5296 been stated separately; in particular common proof methods need to be
  5297 repeated in order to cover all claims; note that a single elimination
  5298 step is *not* sufficient to establish the two conjunctions, so this
  5299 fails:
  5300 
  5301   assume "A & B" then have A and B ..   (*".." fails*)
  5302 
  5303 better use "obtain" in situations as above; alternative refer to
  5304 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5305 
  5306 * Pure: proper integration with ``locales''; unlike the original
  5307 version by Florian Kammller, Isar locales package high-level proof
  5308 contexts rather than raw logical ones (e.g. we admit to include
  5309 attributes everywhere); operations on locales include merge and
  5310 rename; support for implicit arguments (``structures''); simultaneous
  5311 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5312 some examples;
  5313 
  5314 * Pure: the following commands have been ``localized'', supporting a
  5315 target locale specification "(in name)": 'lemma', 'theorem',
  5316 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5317 stored both within the locale and at the theory level (exported and
  5318 qualified by the locale name);
  5319 
  5320 * Pure: theory goals may now be specified in ``long'' form, with
  5321 ad-hoc contexts consisting of arbitrary locale elements. for example
  5322 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5323 definitions may be given, too); the result is a meta-level rule with
  5324 the context elements being discharged in the obvious way;
  5325 
  5326 * Pure: new proof command 'using' allows to augment currently used
  5327 facts after a goal statement ('using' is syntactically analogous to
  5328 'apply', but acts on the goal's facts only); this allows chained facts
  5329 to be separated into parts given before and after a claim, as in
  5330 ``from a and b have C using d and e <proof>'';
  5331 
  5332 * Pure: renamed "antecedent" case to "rule_context";
  5333 
  5334 * Pure: new 'judgment' command records explicit information about the
  5335 object-logic embedding (used by several tools internally); no longer
  5336 use hard-wired "Trueprop";
  5337 
  5338 * Pure: added 'corollary' command;
  5339 
  5340 * Pure: fixed 'token_translation' command;
  5341 
  5342 * Pure: removed obsolete 'exported' attribute;
  5343 
  5344 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5345 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5346 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5347 
  5348 * Pure: method 'atomize' presents local goal premises as object-level
  5349 statements (atomic meta-level propositions); setup controlled via
  5350 rewrite rules declarations of 'atomize' attribute; example
  5351 application: 'induct' method with proper rule statements in improper
  5352 proof *scripts*;
  5353 
  5354 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5355 now consider the syntactic context of assumptions, giving a better
  5356 chance to get type-inference of the arguments right (this is
  5357 especially important for locales);
  5358 
  5359 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5360 mode;
  5361 
  5362 * Pure/obtain: the formal conclusion "thesis", being marked as
  5363 ``internal'', may no longer be reference directly in the text;
  5364 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5365 situations;
  5366 
  5367 * Pure: generic 'sym' attribute which declares a rule both as pure
  5368 'elim?' and for the 'symmetric' operation;
  5369 
  5370 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5371 text; the fixed correlation with particular command syntax has been
  5372 discontinued;
  5373 
  5374 * Pure: new method 'rules' is particularly well-suited for proof
  5375 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5376 but often produces more compact proof terms with less detours;
  5377 
  5378 * Pure/Provers/classical: simplified integration with pure rule
  5379 attributes and methods; the classical "intro?/elim?/dest?"
  5380 declarations coincide with the pure ones; the "rule" method no longer
  5381 includes classically swapped intros; "intro" and "elim" methods no
  5382 longer pick rules from the context; also got rid of ML declarations
  5383 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5384 INCOMPATIBILITY;
  5385 
  5386 * Provers/classical: attribute 'swapped' produces classical inversions
  5387 of introduction rules;
  5388 
  5389 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5390 rules instead of full simplifier context; 'iff' attribute handles
  5391 conditional rules;
  5392 
  5393 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5394 
  5395 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5396 "(permissive)" option to recover old behavior;
  5397 
  5398 * HOL: 'inductive' no longer features separate (collective) attributes
  5399 for 'intros' (was found too confusing);
  5400 
  5401 * HOL: properly declared induction rules less_induct and
  5402 wf_induct_rule;
  5403 
  5404 
  5405 *** HOL ***
  5406 
  5407 * HOL: moved over to sane numeral syntax; the new policy is as
  5408 follows:
  5409 
  5410   - 0 and 1 are polymorphic constants, which are defined on any
  5411   numeric type (nat, int, real etc.);
  5412 
  5413   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5414   binary representation internally;
  5415 
  5416   - type nat has special constructor Suc, and generally prefers Suc 0
  5417   over 1::nat and Suc (Suc 0) over 2::nat;
  5418 
  5419 This change may cause significant problems of INCOMPATIBILITY; here
  5420 are some hints on converting existing sources:
  5421 
  5422   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5423   entities, so expressions involving "-" (unary or binary minus) need
  5424   to be spaced properly;
  5425 
  5426   - existing occurrences of "1" may need to be constraint "1::nat" or
  5427   even replaced by Suc 0; similar for old "2";
  5428 
  5429   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5430 
  5431   - remove all special provisions on numerals in proofs;
  5432 
  5433 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5434 representation (depends on bin_arith_simps in the default context);
  5435 
  5436 * HOL: symbolic syntax for x^2 (numeral 2);
  5437 
  5438 * HOL: the class of all HOL types is now called "type" rather than
  5439 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5440 in axclass/classes, instance/arities, and (usually rare) occurrences
  5441 in typings (of consts etc.); internally the class is called
  5442 "HOL.type", ML programs should refer to HOLogic.typeS;
  5443 
  5444 * HOL/record package improvements:
  5445   - new derived operations "fields" to build a partial record section,
  5446     "extend" to promote a fixed record to a record scheme, and
  5447     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5448     declared as simp by default;
  5449   - shared operations ("more", "fields", etc.) now need to be always
  5450     qualified) --- potential INCOMPATIBILITY;
  5451   - removed "make_scheme" operations (use "make" with "extend") --
  5452     INCOMPATIBILITY;
  5453   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5454   - provides cases/induct rules for use with corresponding Isar
  5455     methods (for concrete records, record schemes, concrete more
  5456     parts, and schematic more parts -- in that order);
  5457   - internal definitions directly based on a light-weight abstract
  5458     theory of product types over typedef rather than datatype;
  5459 
  5460 * HOL: generic code generator for generating executable ML code from
  5461 specifications; specific support for HOL constructs such as inductive
  5462 datatypes and sets, as well as recursive functions; can be invoked
  5463 via 'generate_code' theory section;
  5464 
  5465 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5466 
  5467 * HOL: consolidated and renamed several theories.  In particular:
  5468         Ord.thy has been absorbed into HOL.thy
  5469         String.thy has been absorbed into List.thy
  5470 
  5471 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5472 (beware of argument permutation!);
  5473 
  5474 * HOL: linorder_less_split superseded by linorder_cases;
  5475 
  5476 * HOL/List: "nodups" renamed to "distinct";
  5477 
  5478 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5479 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5480   - Ex_def has changed, now need to use some_eq_ex
  5481 
  5482 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5483 in this (rare) case use:
  5484 
  5485   delSWrapper "split_all_tac"
  5486   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5487 
  5488 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5489 MAY FAIL;
  5490 
  5491 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5492 Isabelle's type classes, ^ on functions and relations has too general
  5493 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5494 necessary to attach explicit type constraints;
  5495 
  5496 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5497 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5498 renamed accordingly (eg "compI" -> "rel_compI").
  5499 
  5500 * HOL: syntax translations now work properly with numerals and records
  5501 expressions;
  5502 
  5503 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5504 of "lam" -- INCOMPATIBILITY;
  5505 
  5506 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5507 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5508 renamed "Product_Type.unit";
  5509 
  5510 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5511 
  5512 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5513 the "cases" method);
  5514 
  5515 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5516 Florian Kammller);
  5517 
  5518 * HOL/IMP: updated and converted to new-style theory format; several
  5519 parts turned into readable document, with proper Isar proof texts and
  5520 some explanations (by Gerwin Klein);
  5521 
  5522 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5523 
  5524 * HOL-Hyperreal is now a logic image;
  5525 
  5526 
  5527 *** HOLCF ***
  5528 
  5529 * Isar: consts/constdefs supports mixfix syntax for continuous
  5530 operations;
  5531 
  5532 * Isar: domain package adapted to new-style theory format, e.g. see
  5533 HOLCF/ex/Dnat.thy;
  5534 
  5535 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5536 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5537 lift.induct_tac, always use UU instead of Undef;
  5538 
  5539 * HOLCF/IMP: updated and converted to new-style theory;
  5540 
  5541 
  5542 *** ZF ***
  5543 
  5544 * Isar: proper integration of logic-specific tools and packages,
  5545 including theory commands '(co)inductive', '(co)datatype',
  5546 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5547 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5548 
  5549 * theory Main no longer includes AC; for the Axiom of Choice, base
  5550 your theory on Main_ZFC;
  5551 
  5552 * the integer library now covers quotients and remainders, with many
  5553 laws relating division to addition, multiplication, etc.;
  5554 
  5555 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5556 typeless version of the formalism;
  5557 
  5558 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5559 format;
  5560 
  5561 * ZF/Induct: new directory for examples of inductive definitions,
  5562 including theory Multiset for multiset orderings; converted to
  5563 new-style theory format;
  5564 
  5565 * ZF: many new theorems about lists, ordinals, etc.;
  5566 
  5567 
  5568 *** General ***
  5569 
  5570 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5571 variable proof controls level of detail: 0 = no proofs (only oracle
  5572 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5573 also ref manual for further ML interfaces;
  5574 
  5575 * Pure/axclass: removed obsolete ML interface
  5576 goal_subclass/goal_arity;
  5577 
  5578 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5579 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5580 separate tokens, so expressions involving minus need to be spaced
  5581 properly;
  5582 
  5583 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5584 rather than "infixl" or "infixr";
  5585 
  5586 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5587 sort constraint specifications in type inference; e.g. "x::_::foo"
  5588 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5589 type variable);
  5590 
  5591 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5592 control output of nested => (types); the default behavior is
  5593 "type_brackets";
  5594 
  5595 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5596 tokens into AST constants;
  5597 
  5598 * Pure/syntax: prefer later declarations of translations and print
  5599 translation functions; potential INCOMPATIBILITY: need to reverse
  5600 multiple declarations for same syntax element constant;
  5601 
  5602 * Pure/show_hyps reset by default (in accordance to existing Isar
  5603 practice);
  5604 
  5605 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5606 addSafter;
  5607 
  5608 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5609 as well;
  5610 
  5611 * system: tested support for MacOS X; should be able to get Isabelle +
  5612 Proof General to work in a plain Terminal after installing Poly/ML
  5613 (e.g. from the Isabelle distribution area) and GNU bash alone
  5614 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5615 support requires further installations, e.g. from
  5616 http://fink.sourceforge.net/);
  5617 
  5618 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5619 
  5620 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5621 of 40 MB), cf. ML_OPTIONS;
  5622 
  5623 * system: Proof General keywords specification is now part of the
  5624 Isabelle distribution (see etc/isar-keywords.el);
  5625 
  5626 * system: support for persistent Proof General sessions (refrain from
  5627 outdating all loaded theories on startup); user may create writable
  5628 logic images like this: ``isabelle -q HOL Test'';
  5629 
  5630 * system: smart selection of Isabelle process versus Isabelle
  5631 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5632 run both "isabelle" and "Isabelle" even if file names are badly
  5633 damaged (executable inspects the case of the first letter of its own
  5634 name); added separate "isabelle-process" and "isabelle-interface";
  5635 
  5636 * system: refrain from any attempt at filtering input streams; no
  5637 longer support ``8bit'' encoding of old isabelle font, instead proper
  5638 iso-latin characters may now be used; the related isatools
  5639 "symbolinput" and "nonascii" have disappeared as well;
  5640 
  5641 * system: removed old "xterm" interface (the print modes "xterm" and
  5642 "xterm_color" are still available for direct use in a suitable
  5643 terminal);
  5644 
  5645 
  5646 
  5647 New in Isabelle99-2 (February 2001)
  5648 -----------------------------------
  5649 
  5650 *** Overview of INCOMPATIBILITIES ***
  5651 
  5652 * HOL: please note that theories in the Library and elsewhere often use the
  5653 new-style (Isar) format; to refer to their theorems in an ML script you must
  5654 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5655 
  5656 * HOL: inductive package no longer splits induction rule aggressively,
  5657 but only as far as specified by the introductions given; the old
  5658 format may be recovered via ML function complete_split_rule or attribute
  5659 'split_rule (complete)';
  5660 
  5661 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5662 gfp_Tarski to gfp_unfold;
  5663 
  5664 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5665 
  5666 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5667 relation); infix "^^" has been renamed "``"; infix "``" has been
  5668 renamed "`"; "univalent" has been renamed "single_valued";
  5669 
  5670 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5671 operation;
  5672 
  5673 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5674 
  5675 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5676 
  5677 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5678 consequence, it is no longer monotonic wrt. the local goal context
  5679 (which is now passed through the inductive cases);
  5680 
  5681 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5682 \<gg> to \<ggreater>;
  5683 
  5684 
  5685 *** Document preparation ***
  5686 
  5687 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5688 available: are "it" for near math-mode best-style output, "sl" for
  5689 slanted text style, and "tt" for plain type-writer; if no
  5690 \isabellestyle command is given, output is according to slanted
  5691 type-writer);
  5692 
  5693 * support sub/super scripts (for single symbols only), input syntax is
  5694 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5695 
  5696 * some more standard symbols; see Appendix A of the system manual for
  5697 the complete list of symbols defined in isabellesym.sty;
  5698 
  5699 * improved isabelle style files; more abstract symbol implementation
  5700 (should now use \isamath{...} and \isatext{...} in custom symbol
  5701 definitions);
  5702 
  5703 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5704 state; Note that presentation of goal states does not conform to
  5705 actual human-readable proof documents.  Please do not include goal
  5706 states into document output unless you really know what you are doing!
  5707 
  5708 * proper indentation of antiquoted output with proportional LaTeX
  5709 fonts;
  5710 
  5711 * no_document ML operator temporarily disables LaTeX document
  5712 generation;
  5713 
  5714 * isatool unsymbolize tunes sources for plain ASCII communication;
  5715 
  5716 
  5717 *** Isar ***
  5718 
  5719 * Pure: Isar now suffers initial goal statements to contain unbound
  5720 schematic variables (this does not conform to actual readable proof
  5721 documents, due to unpredictable outcome and non-compositional proof
  5722 checking); users who know what they are doing may use schematic goals
  5723 for Prolog-style synthesis of proven results;
  5724 
  5725 * Pure: assumption method (an implicit finishing) now handles actual
  5726 rules as well;
  5727 
  5728 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5729 initial goal, declare "that" only as Pure intro (only for single
  5730 steps); the "that" rule assumption may now be involved in implicit
  5731 finishing, thus ".." becomes a feasible for trivial obtains;
  5732 
  5733 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5734 instance proofs may be performed by "..";
  5735 
  5736 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5737 statements as well;
  5738 
  5739 * Pure: more robust selection of calculational rules;
  5740 
  5741 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5742 rule (as well as the assumption rule);
  5743 
  5744 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5745 lemmas, using the graph browser tool;
  5746 
  5747 * Pure: predict failure of "show" in interactive mode;
  5748 
  5749 * Pure: 'thms_containing' now takes actual terms as arguments;
  5750 
  5751 * HOL: improved method 'induct' --- now handles non-atomic goals
  5752 (potential INCOMPATIBILITY); tuned error handling;
  5753 
  5754 * HOL: cases and induct rules now provide explicit hints about the
  5755 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5756 any remaining facts are inserted into the goal verbatim;
  5757 
  5758 * HOL: local contexts (aka cases) may now contain term bindings as
  5759 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5760 the result to be shown in each case;
  5761 
  5762 * HOL: added 'recdef_tc' command;
  5763 
  5764 * isatool convert assists in eliminating legacy ML scripts;
  5765 
  5766 
  5767 *** HOL ***
  5768 
  5769 * HOL/Library: a collection of generic theories to be used together
  5770 with main HOL; the theory loader path already includes this directory
  5771 by default; the following existing theories have been moved here:
  5772 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5773 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5774 
  5775 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5776 modelling and verification task performed in Isabelle/HOL +
  5777 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5778 
  5779 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5780 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5781 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5782 'domain', this makes the theory consistent with mathematical
  5783 literature;
  5784 
  5785 * HOL basics: added overloaded operations "inverse" and "divide"
  5786 (infix "/"), syntax for generic "abs" operation, generic summation
  5787 operator \<Sum>;
  5788 
  5789 * HOL/typedef: simplified package, provide more useful rules (see also
  5790 HOL/subset.thy);
  5791 
  5792 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5793 now expressed as a proper nested rule (old-style tactic scripts may
  5794 require atomize_strip_tac to cope with non-atomic premises);
  5795 
  5796 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5797 to "split_conv" (old name still available for compatibility);
  5798 
  5799 * HOL: improved concrete syntax for strings (e.g. allows translation
  5800 rules with string literals);
  5801 
  5802 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5803  and Fleuriot's mechanization of analysis, including the transcendental
  5804  functions for the reals;
  5805 
  5806 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5807 
  5808 
  5809 *** CTT ***
  5810 
  5811 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5812 "lam" is displayed as TWO lambda-symbols
  5813 
  5814 * CTT: theory Main now available, containing everything (that is, Bool
  5815 and Arith);
  5816 
  5817 
  5818 *** General ***
  5819 
  5820 * Pure: the Simplifier has been implemented properly as a derived rule
  5821 outside of the actual kernel (at last!); the overall performance
  5822 penalty in practical applications is about 50%, while reliability of
  5823 the Isabelle inference kernel has been greatly improved;
  5824 
  5825 * print modes "brackets" and "no_brackets" control output of nested =>
  5826 (types) and ==> (props); the default behaviour is "brackets";
  5827 
  5828 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5829 as assumptions as well;
  5830 
  5831 * system: support Poly/ML 4.0;
  5832 
  5833 * system: isatool install handles KDE version 1 or 2;
  5834 
  5835 
  5836 
  5837 New in Isabelle99-1 (October 2000)
  5838 ----------------------------------
  5839 
  5840 *** Overview of INCOMPATIBILITIES ***
  5841 
  5842 * HOL: simplification of natural numbers is much changed; to partly
  5843 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5844 issue the following ML commands:
  5845 
  5846   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5847   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5848 
  5849 * HOL: simplification no longer dives into case-expressions; this is
  5850 controlled by "t.weak_case_cong" for each datatype t;
  5851 
  5852 * HOL: nat_less_induct renamed to less_induct;
  5853 
  5854 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5855 fixsome to patch .thy and .ML sources automatically;
  5856 
  5857   select_equality  -> some_equality
  5858   select_eq_Ex     -> some_eq_ex
  5859   selectI2EX       -> someI2_ex
  5860   selectI2         -> someI2
  5861   selectI          -> someI
  5862   select1_equality -> some1_equality
  5863   Eps_sym_eq       -> some_sym_eq_trivial
  5864   Eps_eq           -> some_eq_trivial
  5865 
  5866 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5867 
  5868 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5869 instead);
  5870 
  5871 * HOL: the recursion equations generated by 'recdef' are now called
  5872 f.simps instead of f.rules;
  5873 
  5874 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5875 
  5876 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5877 sometimes be needed;
  5878 
  5879 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5880 
  5881 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5882 
  5883 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5884 product is now "<*>" instead of "Times"; the lexicographic product is
  5885 now "<*lex*>" instead of "**";
  5886 
  5887 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5888 of main HOL, but was unused); better use HOL's datatype package;
  5889 
  5890 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5891 the old syntax may be recovered as follows:
  5892 
  5893   syntax (symbols)
  5894     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5895       (infixl "\\<oplus>" 100)
  5896 
  5897 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5898 
  5899 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5900 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5901 internally;
  5902 
  5903 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5904 changed from A/r to A//r;
  5905 
  5906 * ZF: new treatment of arithmetic (nat & int) may break some old
  5907 proofs;
  5908 
  5909 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5910 rulify -> rule_format, elimify -> elim_format, ...);
  5911 
  5912 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5913 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5914 should have to change intro!! to intro? only); replaced "delrule" by
  5915 "rule del";
  5916 
  5917 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5918 
  5919 * Provers: strengthened force_tac by using new first_best_tac;
  5920 
  5921 * LaTeX document preparation: several changes of isabelle.sty (see
  5922 lib/texinputs);
  5923 
  5924 
  5925 *** Document preparation ***
  5926 
  5927 * formal comments (text blocks etc.) in new-style theories may now
  5928 contain antiquotations of thm/prop/term/typ/text to be presented
  5929 according to latex print mode; concrete syntax is like this:
  5930 @{term[show_types] "f(x) = a + x"};
  5931 
  5932 * isatool mkdir provides easy setup of Isabelle session directories,
  5933 including proper document sources;
  5934 
  5935 * generated LaTeX sources are now deleted after successful run
  5936 (isatool document -c); may retain a copy somewhere else via -D option
  5937 of isatool usedir;
  5938 
  5939 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5940 style files, achieving self-contained LaTeX sources and simplifying
  5941 LaTeX debugging;
  5942 
  5943 * old-style theories now produce (crude) LaTeX output as well;
  5944 
  5945 * browser info session directories are now self-contained (may be put
  5946 on WWW server seperately); improved graphs of nested sessions; removed
  5947 graph for 'all sessions';
  5948 
  5949 * several improvements in isabelle style files; \isabellestyle{it}
  5950 produces fake math mode output; \isamarkupheader is now \section by
  5951 default; see lib/texinputs/isabelle.sty etc.;
  5952 
  5953 
  5954 *** Isar ***
  5955 
  5956 * Isar/Pure: local results and corresponding term bindings are now
  5957 subject to Hindley-Milner polymorphism (similar to ML); this
  5958 accommodates incremental type-inference very nicely;
  5959 
  5960 * Isar/Pure: new derived language element 'obtain' supports
  5961 generalized existence reasoning;
  5962 
  5963 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5964 support accumulation of results, without applying any rules yet;
  5965 useful to collect intermediate results without explicit name
  5966 references, and for use with transitivity rules with more than 2
  5967 premises;
  5968 
  5969 * Isar/Pure: scalable support for case-analysis type proofs: new
  5970 'case' language element refers to local contexts symbolically, as
  5971 produced by certain proof methods; internally, case names are attached
  5972 to theorems as "tags";
  5973 
  5974 * Isar/Pure: theory command 'hide' removes declarations from
  5975 class/type/const name spaces;
  5976 
  5977 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5978 indicate potential overloading;
  5979 
  5980 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5981 
  5982 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5983 "{a,b,c}" instead of {a,b,c};
  5984 
  5985 * Isar/Pure now provides its own version of intro/elim/dest
  5986 attributes; useful for building new logics, but beware of confusion
  5987 with the version in Provers/classical;
  5988 
  5989 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5990 case name 'antecedent';
  5991 
  5992 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5993 to the current context is now done automatically);
  5994 
  5995 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5996 for definining proof methods in ML;
  5997 
  5998 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5999 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6000 most cases, one should have to change intro!! to intro? only);
  6001 replaced "delrule" by "rule del";
  6002 
  6003 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6004 'symmetric' attribute (the latter supercedes [RS sym]);
  6005 
  6006 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6007 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6008 well (including splits);
  6009 
  6010 * Isar/Provers: Simplifier and Classical methods now support all kind
  6011 of modifiers used in the past, including 'cong', 'iff', etc.
  6012 
  6013 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6014 of Simplifier and Classical reasoner);
  6015 
  6016 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6017 now support named cases; major packages (inductive, datatype, primrec,
  6018 recdef) support case names and properly name parameters;
  6019 
  6020 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6021 monotonicity conditions are extracted to be proven at end of
  6022 calculations;
  6023 
  6024 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6025 method anyway;
  6026 
  6027 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6028 split_if split_if_asm; datatype package provides theorems foo.splits =
  6029 foo.split foo.split_asm for each datatype;
  6030 
  6031 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6032 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6033 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6034 use "(cases (simplified))" method in proper proof texts);
  6035 
  6036 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6037 
  6038 * Isar: names of theorems etc. may be natural numbers as well;
  6039 
  6040 * Isar: 'pr' command: optional arguments for goals_limit and
  6041 ProofContext.prems_limit; no longer prints theory contexts, but only
  6042 proof states;
  6043 
  6044 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6045 additional print modes to be specified; e.g. "pr(latex)" will print
  6046 proof state according to the Isabelle LaTeX style;
  6047 
  6048 * Isar: improved support for emulating tactic scripts, including proof
  6049 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6050 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6051 (for HOL datatypes);
  6052 
  6053 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6054 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6055 'proof method scripts' have to be in depth-first order;
  6056 
  6057 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6058 
  6059 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6060 should instead use individual commands for printing items
  6061 (print_commands, print_methods etc.);
  6062 
  6063 * Isar: added 'nothing' --- the empty list of theorems;
  6064 
  6065 
  6066 *** HOL ***
  6067 
  6068 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6069 corresponding virtual machine and a specification of its bytecode
  6070 verifier and a lightweight bytecode verifier, including proofs of
  6071 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6072 Cornelia Pusch (see also the homepage of project Bali at
  6073 http://isabelle.in.tum.de/Bali/);
  6074 
  6075 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6076 Clemens Ballarin;
  6077 
  6078 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6079 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6080 Rasmussen;
  6081 
  6082 * HOL/Lattice: fundamental concepts of lattice theory and order
  6083 structures, including duals, properties of bounds versus algebraic
  6084 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6085 Theorem for complete lattices etc.; may also serve as a demonstration
  6086 for abstract algebraic reasoning using axiomatic type classes, and
  6087 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6088 
  6089 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6090 von Oheimb;
  6091 
  6092 * HOL/IMPP: extension of IMP with local variables and mutually
  6093 recursive procedures, by David von Oheimb;
  6094 
  6095 * HOL/Lambda: converted into new-style theory and document;
  6096 
  6097 * HOL/ex/Multiquote: example of multiple nested quotations and
  6098 anti-quotations -- basically a generalized version of de-Bruijn
  6099 representation; very useful in avoiding lifting of operations;
  6100 
  6101 * HOL/record: added general record equality rule to simpset; fixed
  6102 select-update simplification procedure to handle extended records as
  6103 well; admit "r" as field name;
  6104 
  6105 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6106 other numeric types and also as the identity of groups, rings, etc.;
  6107 
  6108 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6109 Types nat and int belong to this axclass;
  6110 
  6111 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6112    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6113    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6114   two terms #m*u and #n*u are replaced by #(m+n)*u
  6115     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6116   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6117     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6118 
  6119 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6120 powerful prover for predicate logic but knows nothing of clasets; see
  6121 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6122 
  6123 * HOL: new version of "case_tac" subsumes both boolean case split and
  6124 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6125 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6126 
  6127 * HOL: simplification no longer dives into case-expressions: only the
  6128 selector expression is simplified, but not the remaining arms; to
  6129 enable full simplification of case-expressions for datatype t, you may
  6130 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6131 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6132 
  6133 * HOL/recdef: the recursion equations generated by 'recdef' for
  6134 function 'f' are now called f.simps instead of f.rules; if all
  6135 termination conditions are proved automatically, these simplification
  6136 rules are added to the simpset, as in primrec; rules may be named
  6137 individually as well, resulting in a separate list of theorems for
  6138 each equation;
  6139 
  6140 * HOL/While is a new theory that provides a while-combinator. It
  6141 permits the definition of tail-recursive functions without the
  6142 provision of a termination measure. The latter is necessary once the
  6143 invariant proof rule for while is applied.
  6144 
  6145 * HOL: new (overloaded) notation for the set of elements below/above
  6146 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6147 
  6148 * HOL: theorems impI, allI, ballI bound as "strip";
  6149 
  6150 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6151 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6152 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6153 
  6154 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6155 
  6156 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6157 main HOL, but was unused);
  6158 
  6159 * HOL: fewer consts declared as global (e.g. have to refer to
  6160 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6161 
  6162 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6163 in case of overlap with user translations (e.g. judgements over
  6164 tuples); (note that the underlying logical represenation is still
  6165 bogus);
  6166 
  6167 
  6168 *** ZF ***
  6169 
  6170 * ZF: simplification automatically cancels common terms in arithmetic
  6171 expressions over nat and int;
  6172 
  6173 * ZF: new treatment of nat to minimize type-checking: all operators
  6174 coerce their operands to a natural number using the function natify,
  6175 making the algebraic laws unconditional;
  6176 
  6177 * ZF: as above, for int: operators coerce their operands to an integer
  6178 using the function intify;
  6179 
  6180 * ZF: the integer library now contains many of the usual laws for the
  6181 orderings, including $<=, and monotonicity laws for $+ and $*;
  6182 
  6183 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6184 simplification;
  6185 
  6186 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6187 to the simplifier and classical reasoner simultaneously;
  6188 
  6189 
  6190 *** General ***
  6191 
  6192 * Provers: blast_tac now handles actual object-logic rules as
  6193 assumptions; note that auto_tac uses blast_tac internally as well;
  6194 
  6195 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6196 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6197 
  6198 * Provers: delrules now handles destruct rules as well (no longer need
  6199 explicit make_elim);
  6200 
  6201 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6202   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6203 use instead the strong form,
  6204   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6205 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6206 from destruct-rules;
  6207 
  6208 * Provers: Simplifier.easy_setup provides a fast path to basic
  6209 Simplifier setup for new object-logics;
  6210 
  6211 * Pure: AST translation rules no longer require constant head on LHS;
  6212 
  6213 * Pure: improved name spaces: ambiguous output is qualified; support
  6214 for hiding of names;
  6215 
  6216 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6217 XSYMBOL_HOME; no longer need to do manual configuration in most
  6218 situations;
  6219 
  6220 * system: compression of ML heaps images may now be controlled via -c
  6221 option of isabelle and isatool usedir (currently only observed by
  6222 Poly/ML);
  6223 
  6224 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6225 useful for remote X11);
  6226 
  6227 * system: provide TAGS file for Isabelle sources;
  6228 
  6229 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument