NEWS
author haftmann
Sat Aug 28 16:14:32 2010 +0200 (2010-08-28)
changeset 38864 4abe644fcea5
parent 38858 1920158cfa17
child 38980 af73cf0dc31f
child 39077 ee78849c1624
permissions -rw-r--r--
formerly unnamed infix equality now named HOL.eq
     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 * Various options that affect document antiquotations are now properly
    27 handled within the context via configuration options, instead of
    28 unsynchronized references.  There are both ML Config.T entities and
    29 Isar declaration attributes to access these.
    30 
    31   ML:                       Isar:
    32 
    33   Thy_Output.display        thy_output_display
    34   Thy_Output.quotes         thy_output_quotes
    35   Thy_Output.indent         thy_output_indent
    36   Thy_Output.source         thy_output_source
    37   Thy_Output.break          thy_output_break
    38 
    39 Note that the corresponding "..._default" references may be only
    40 changed globally at the ROOT session setup, but *not* within a theory.
    41 
    42 * ML structure Unsynchronized never opened, not even in Isar
    43 interaction mode as before.  Old Unsynchronized.set etc. have been
    44 discontinued -- use plain := instead.  This should be *rare* anyway,
    45 since modern tools always work via official context data, notably
    46 configuration options.
    47 
    48 
    49 *** Pure ***
    50 
    51 * Interpretation command 'interpret' accepts a list of equations like
    52 'interpretation' does.
    53 
    54 * Diagnostic command 'print_interps' prints interpretations in proofs
    55 in addition to interpretations in theories.
    56 
    57 * Discontinued obsolete 'global' and 'local' commands to manipulate
    58 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    59 Sign.root_path and Sign.local_path may be applied directly where this
    60 feature is still required for historical reasons.
    61 
    62 
    63 *** HOL ***
    64 
    65 * Renamed class eq and constant eq (for code generation) to class equal
    66 and constant equal, plus renaming of related facts and various tuning.
    67 INCOMPATIBILITY.
    68 
    69 * Scala (2.8 or higher) has been added to the target languages of
    70 the code generator.
    71 
    72 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    73 
    74 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    75 canonical names for instance definitions for functions; various improvements.
    76 INCOMPATIBILITY.
    77 
    78 * Records: logical foundation type for records do not carry a '_type' suffix
    79 any longer.  INCOMPATIBILITY.
    80 
    81 * Code generation for records: more idiomatic representation of record types.
    82 Warning: records are not covered by ancient SML code generation any longer.
    83 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    84 helps to succeed then:
    85 
    86   record 'a foo = ...
    87   ...
    88   rep_datatype foo_ext ...
    89 
    90 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    91 INCOMPATIBILITY.
    92 
    93 * Quickcheck in locales considers interpretations of that locale for
    94 counter example search.
    95 
    96 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    97 in Library/State_Monad has been changed to avoid ambiguities.
    98 INCOMPATIBILITY.
    99 
   100 * Code generator: export_code without explicit file declaration prints
   101 to standard output.  INCOMPATIBILITY.
   102 
   103 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   104 respectively.  INCOMPATIBILITY.
   105 
   106 * Constant "split" has been merged with constant "prod_case";  names
   107 of ML functions, facts etc. involving split have been retained so far,
   108 though.  INCOMPATIBILITY.
   109 
   110 * Dropped old infix syntax "mem" for List.member;  use "in set"
   111 instead.  INCOMPATIBILITY.
   112 
   113 * Refactoring of code-generation specific operations in List.thy
   114 
   115   constants
   116     null ~> List.null
   117 
   118   facts
   119     mem_iff ~> member_def
   120     null_empty ~> null_def
   121 
   122 INCOMPATIBILITY.  Note that these were not suppossed to be used
   123 regularly unless for striking reasons;  their main purpose was code
   124 generation.
   125 
   126 * Some previously unqualified names have been qualified:
   127 
   128   types
   129     bool ~> HOL.bool
   130     nat ~> Nat.nat
   131 
   132   constants
   133     Trueprop ~> HOL.Trueprop
   134     True ~> HOL.True
   135     False ~> HOL.False
   136     op & ~> HOL.conj
   137     op | ~> HOL.disj
   138     op --> ~> HOL.implies
   139     op = ~> HOL.eq
   140     Not ~> HOL.Not
   141     The ~> HOL.The
   142     All ~> HOL.All
   143     Ex ~> HOL.Ex
   144     Ex1 ~> HOL.Ex1
   145     Let ~> HOL.Let
   146     If ~> HOL.If
   147     Ball ~> Set.Ball
   148     Bex ~> Set.Bex
   149     Suc ~> Nat.Suc
   150     Pair ~> Product_Type.Pair
   151     fst ~> Product_Type.fst
   152     snd ~> Product_Type.snd
   153     curry ~> Product_Type.curry
   154     op : ~> Set.member
   155     Collect ~> Set.Collect
   156 
   157 INCOMPATIBILITY.
   158 
   159 * Removed simplifier congruence rule of "prod_case", as has for long
   160 been the case with "split".  INCOMPATIBILITY.
   161 
   162 * Datatype package: theorems generated for executable equality
   163 (class eq) carry proper names and are treated as default code
   164 equations.
   165 
   166 * List.thy: use various operations from the Haskell prelude when
   167 generating Haskell code.
   168 
   169 * code_simp.ML and method code_simp: simplification with rules determined
   170 by code generator.
   171 
   172 * code generator: do not print function definitions for case
   173 combinators any longer.
   174 
   175 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   176 theorems are now stated in terms of euclidean spaces instead of finite
   177 cartesian products.
   178 
   179   types
   180     real ^ 'n ~>  'a::real_vector
   181               ~>  'a::euclidean_space
   182               ~>  'a::ordered_euclidean_space
   183         (depends on your needs)
   184 
   185   constants
   186      _ $ _        ~> _ $$ _
   187      \<chi> x. _  ~> \<chi>\<chi> x. _
   188      CARD('n)     ~> DIM('a)
   189 
   190 Also note that the indices are now natural numbers and not from some finite
   191 type. Finite cartesian products of euclidean spaces, products of euclidean
   192 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   193 
   194 INCOMPATIBILITY.
   195 
   196 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   197 as value for measures. Introduces Lebesgue Measure based on the integral in
   198 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   199 spaces.
   200 
   201  INCOMPATIBILITY.
   202 
   203 * Inductive package: offers new command "inductive_simps" to automatically
   204 derive instantiated and simplified equations for inductive predicates,
   205 similar to inductive_cases.
   206 
   207 
   208 *** FOL ***
   209 
   210 * All constant names are now qualified.  INCOMPATIBILITY.
   211 
   212 
   213 *** ZF ***
   214 
   215 * All constant names are now qualified.  INCOMPATIBILITY.
   216 
   217 
   218 *** ML ***
   219 
   220 * ML antiquotations @{theory} and @{theory_ref} refer to named
   221 theories from the ancestry of the current context, not any accidental
   222 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   223 change in semantics.
   224 
   225 
   226 *** System ***
   227 
   228 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   229 
   230 
   231 
   232 New in Isabelle2009-2 (June 2010)
   233 ---------------------------------
   234 
   235 *** General ***
   236 
   237 * Authentic syntax for *all* logical entities (type classes, type
   238 constructors, term constants): provides simple and robust
   239 correspondence between formal entities and concrete syntax.  Within
   240 the parse tree / AST representations, "constants" are decorated by
   241 their category (class, type, const) and spelled out explicitly with
   242 their full internal name.
   243 
   244 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   245 and translations (translation rules and translation functions in ML).
   246 Some hints on upgrading:
   247 
   248   - Many existing uses of 'syntax' and 'translations' can be replaced
   249     by more modern 'type_notation', 'notation' and 'abbreviation',
   250     which are independent of this issue.
   251 
   252   - 'translations' require markup within the AST; the term syntax
   253     provides the following special forms:
   254 
   255       CONST c   -- produces syntax version of constant c from context
   256       XCONST c  -- literally c, checked as constant from context
   257       c         -- literally c, if declared by 'syntax'
   258 
   259     Plain identifiers are treated as AST variables -- occasionally the
   260     system indicates accidental variables via the error "rhs contains
   261     extra variables".
   262 
   263     Type classes and type constructors are marked according to their
   264     concrete syntax.  Some old translations rules need to be written
   265     for the "type" category, using type constructor application
   266     instead of pseudo-term application of the default category
   267     "logic".
   268 
   269   - 'parse_translation' etc. in ML may use the following
   270     antiquotations:
   271 
   272       @{class_syntax c}   -- type class c within parse tree / AST
   273       @{term_syntax c}    -- type constructor c within parse tree / AST
   274       @{const_syntax c}   -- ML version of "CONST c" above
   275       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   276 
   277   - Literal types within 'typed_print_translations', i.e. those *not*
   278     represented as pseudo-terms are represented verbatim.  Use @{class
   279     c} or @{type_name c} here instead of the above syntax
   280     antiquotations.
   281 
   282 Note that old non-authentic syntax was based on unqualified base
   283 names, so all of the above "constant" names would coincide.  Recall
   284 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   285 diagnose syntax problems.
   286 
   287 * Type constructors admit general mixfix syntax, not just infix.
   288 
   289 * Concrete syntax may be attached to local entities without a proof
   290 body, too.  This works via regular mixfix annotations for 'fix',
   291 'def', 'obtain' etc. or via the explicit 'write' command, which is
   292 similar to the 'notation' command in theory specifications.
   293 
   294 * Discontinued unnamed infix syntax (legacy feature for many years) --
   295 need to specify constant name and syntax separately.  Internal ML
   296 datatype constructors have been renamed from InfixName to Infix etc.
   297 Minor INCOMPATIBILITY.
   298 
   299 * Schematic theorem statements need to be explicitly markup as such,
   300 via commands 'schematic_lemma', 'schematic_theorem',
   301 'schematic_corollary'.  Thus the relevance of the proof is made
   302 syntactically clear, which impacts performance in a parallel or
   303 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   304 
   305 * Use of cumulative prems via "!" in some proof methods has been
   306 discontinued (old legacy feature).
   307 
   308 * References 'trace_simp' and 'debug_simp' have been replaced by
   309 configuration options stored in the context. Enabling tracing (the
   310 case of debugging is similar) in proofs works via
   311 
   312   using [[trace_simp = true]]
   313 
   314 Tracing is then active for all invocations of the simplifier in
   315 subsequent goal refinement steps. Tracing may also still be enabled or
   316 disabled via the ProofGeneral settings menu.
   317 
   318 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   319 'hide_fact' replace the former 'hide' KIND command.  Minor
   320 INCOMPATIBILITY.
   321 
   322 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   323 more efficient than combinations with -q1 or -q2.
   324 
   325 
   326 *** Pure ***
   327 
   328 * Proofterms record type-class reasoning explicitly, using the
   329 "unconstrain" operation internally.  This eliminates all sort
   330 constraints from a theorem and proof, introducing explicit
   331 OFCLASS-premises.  On the proof term level, this operation is
   332 automatically applied at theorem boundaries, such that closed proofs
   333 are always free of sort constraints.  INCOMPATIBILITY for tools that
   334 inspect proof terms.
   335 
   336 * Local theory specifications may depend on extra type variables that
   337 are not present in the result type -- arguments TYPE('a) :: 'a itself
   338 are added internally.  For example:
   339 
   340   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   341 
   342 * Predicates of locales introduced by classes carry a mandatory
   343 "class" prefix.  INCOMPATIBILITY.
   344 
   345 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   346 
   347 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   348 'class' instead.
   349 
   350 * Command 'code_reflect' allows to incorporate generated ML code into
   351 runtime environment; replaces immature code_datatype antiquotation.
   352 INCOMPATIBILITY.
   353 
   354 * Code generator: simple concept for abstract datatypes obeying
   355 invariants.
   356 
   357 * Code generator: details of internal data cache have no impact on the
   358 user space functionality any longer.
   359 
   360 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   361 subgoals.  This is more appropriate for interpretations with 'where'.
   362 INCOMPATIBILITY.
   363 
   364 * Command 'example_proof' opens an empty proof body.  This allows to
   365 experiment with Isar, without producing any persistent result.
   366 
   367 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   368 within a local theory context, with explicit checking of the
   369 constructors involved (in contrast to the raw 'syntax' versions).
   370 
   371 * Commands 'types' and 'typedecl' now work within a local theory
   372 context -- without introducing dependencies on parameters or
   373 assumptions, which is not possible in Isabelle/Pure.
   374 
   375 * Command 'defaultsort' has been renamed to 'default_sort', it works
   376 within a local theory context.  Minor INCOMPATIBILITY.
   377 
   378 
   379 *** HOL ***
   380 
   381 * Command 'typedef' now works within a local theory context -- without
   382 introducing dependencies on parameters or assumptions, which is not
   383 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   384 contain multiple interpretations of local typedefs (with different
   385 non-emptiness proofs), even in a global theory context.
   386 
   387 * New package for quotient types.  Commands 'quotient_type' and
   388 'quotient_definition' may be used for defining types and constants by
   389 quotient constructions.  An example is the type of integers created by
   390 quotienting pairs of natural numbers:
   391 
   392   fun
   393     intrel :: "(nat * nat) => (nat * nat) => bool"
   394   where
   395     "intrel (x, y) (u, v) = (x + v = u + y)"
   396 
   397   quotient_type int = "nat * nat" / intrel
   398     by (auto simp add: equivp_def expand_fun_eq)
   399 
   400   quotient_definition
   401     "0::int" is "(0::nat, 0::nat)"
   402 
   403 The method "lifting" can be used to lift of theorems from the
   404 underlying "raw" type to the quotient type.  The example
   405 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   406 construction and provides a reasoning infrastructure for finite sets.
   407 
   408 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   409 clash with new theory Quotient in Main HOL.
   410 
   411 * Moved the SMT binding into the main HOL session, eliminating
   412 separate HOL-SMT session.
   413 
   414 * List membership infix mem operation is only an input abbreviation.
   415 INCOMPATIBILITY.
   416 
   417 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   418 for future developements; former Library/Word.thy is still present in
   419 the AFP entry RSAPPS.
   420 
   421 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   422 longer shadowed.  INCOMPATIBILITY.
   423 
   424 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   425 INCOMPATIBILITY.
   426 
   427 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   428 INCOMPATIBILITY.
   429 
   430 * Dropped normalizing_semiring etc; use the facts in semiring classes
   431 instead.  INCOMPATIBILITY.
   432 
   433 * Dropped several real-specific versions of lemmas about floor and
   434 ceiling; use the generic lemmas from theory "Archimedean_Field"
   435 instead.  INCOMPATIBILITY.
   436 
   437   floor_number_of_eq         ~> floor_number_of
   438   le_floor_eq_number_of      ~> number_of_le_floor
   439   le_floor_eq_zero           ~> zero_le_floor
   440   le_floor_eq_one            ~> one_le_floor
   441   floor_less_eq_number_of    ~> floor_less_number_of
   442   floor_less_eq_zero         ~> floor_less_zero
   443   floor_less_eq_one          ~> floor_less_one
   444   less_floor_eq_number_of    ~> number_of_less_floor
   445   less_floor_eq_zero         ~> zero_less_floor
   446   less_floor_eq_one          ~> one_less_floor
   447   floor_le_eq_number_of      ~> floor_le_number_of
   448   floor_le_eq_zero           ~> floor_le_zero
   449   floor_le_eq_one            ~> floor_le_one
   450   floor_subtract_number_of   ~> floor_diff_number_of
   451   floor_subtract_one         ~> floor_diff_one
   452   ceiling_number_of_eq       ~> ceiling_number_of
   453   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   454   ceiling_le_zero_eq         ~> ceiling_le_zero
   455   ceiling_le_eq_one          ~> ceiling_le_one
   456   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   457   less_ceiling_eq_zero       ~> zero_less_ceiling
   458   less_ceiling_eq_one        ~> one_less_ceiling
   459   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   460   ceiling_less_eq_zero       ~> ceiling_less_zero
   461   ceiling_less_eq_one        ~> ceiling_less_one
   462   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   463   le_ceiling_eq_zero         ~> zero_le_ceiling
   464   le_ceiling_eq_one          ~> one_le_ceiling
   465   ceiling_subtract_number_of ~> ceiling_diff_number_of
   466   ceiling_subtract_one       ~> ceiling_diff_one
   467 
   468 * Theory "Finite_Set": various folding_XXX locales facilitate the
   469 application of the various fold combinators on finite sets.
   470 
   471 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   472 provides abstract red-black tree type which is backed by "RBT_Impl" as
   473 implementation.  INCOMPATIBILTY.
   474 
   475 * Theory Library/Coinductive_List has been removed -- superseded by
   476 AFP/thys/Coinductive.
   477 
   478 * Theory PReal, including the type "preal" and related operations, has
   479 been removed.  INCOMPATIBILITY.
   480 
   481 * Real: new development using Cauchy Sequences.
   482 
   483 * Split off theory "Big_Operators" containing setsum, setprod,
   484 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   485 
   486 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   487 "Int" etc.  INCOMPATIBILITY.
   488 
   489 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   490 
   491 * New set of rules "ac_simps" provides combined assoc / commute
   492 rewrites for all interpretations of the appropriate generic locales.
   493 
   494 * Renamed theory "OrderedGroup" to "Groups" and split theory
   495 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   496 appropriate and more consistent names suitable for name prefixes
   497 within the HOL theories.  INCOMPATIBILITY.
   498 
   499 * Some generic constants have been put to appropriate theories:
   500   - less_eq, less: Orderings
   501   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   502   - inverse, divide: Rings
   503 INCOMPATIBILITY.
   504 
   505 * More consistent naming of type classes involving orderings (and
   506 lattices):
   507 
   508     lower_semilattice                   ~> semilattice_inf
   509     upper_semilattice                   ~> semilattice_sup
   510 
   511     dense_linear_order                  ~> dense_linorder
   512 
   513     pordered_ab_group_add               ~> ordered_ab_group_add
   514     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   515     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   516     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   517     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   518     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   519     pordered_cancel_semiring            ~> ordered_cancel_semiring
   520     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   521     pordered_comm_ring                  ~> ordered_comm_ring
   522     pordered_comm_semiring              ~> ordered_comm_semiring
   523     pordered_ring                       ~> ordered_ring
   524     pordered_ring_abs                   ~> ordered_ring_abs
   525     pordered_semiring                   ~> ordered_semiring
   526 
   527     ordered_ab_group_add                ~> linordered_ab_group_add
   528     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   529     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   530     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   531     ordered_field                       ~> linordered_field
   532     ordered_field_no_lb                 ~> linordered_field_no_lb
   533     ordered_field_no_ub                 ~> linordered_field_no_ub
   534     ordered_field_dense_linear_order    ~> dense_linordered_field
   535     ordered_idom                        ~> linordered_idom
   536     ordered_ring                        ~> linordered_ring
   537     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   538     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   539     ordered_ring_strict                 ~> linordered_ring_strict
   540     ordered_semidom                     ~> linordered_semidom
   541     ordered_semiring                    ~> linordered_semiring
   542     ordered_semiring_1                  ~> linordered_semiring_1
   543     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   544     ordered_semiring_strict             ~> linordered_semiring_strict
   545 
   546   The following slightly odd type classes have been moved to a
   547   separate theory Library/Lattice_Algebras:
   548 
   549     lordered_ab_group_add               ~> lattice_ab_group_add
   550     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   551     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   552     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   553     lordered_ring                       ~> lattice_ring
   554 
   555 INCOMPATIBILITY.
   556 
   557 * Refined field classes:
   558   - classes division_ring_inverse_zero, field_inverse_zero,
   559     linordered_field_inverse_zero include rule inverse 0 = 0 --
   560     subsumes former division_by_zero class;
   561   - numerous lemmas have been ported from field to division_ring.
   562 INCOMPATIBILITY.
   563 
   564 * Refined algebra theorem collections:
   565   - dropped theorem group group_simps, use algebra_simps instead;
   566   - dropped theorem group ring_simps, use field_simps instead;
   567   - proper theorem collection field_simps subsumes former theorem
   568     groups field_eq_simps and field_simps;
   569   - dropped lemma eq_minus_self_iff which is a duplicate for
   570     equal_neg_zero.
   571 INCOMPATIBILITY.
   572 
   573 * Theory Finite_Set and List: some lemmas have been generalized from
   574 sets to lattices:
   575 
   576   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   577   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   578   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   579   union_Union_fold_union        ~> sup_Sup_fold_sup
   580   Inter_fold_inter              ~> Inf_fold_inf
   581   Union_fold_union              ~> Sup_fold_sup
   582   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   583   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   584   INTER_fold_inter              ~> INFI_fold_inf
   585   UNION_fold_union              ~> SUPR_fold_sup
   586 
   587 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   588 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   589 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   590 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   591 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   592 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   593 
   594 * Reorganized theory Multiset: swapped notation of pointwise and
   595 multiset order:
   596 
   597   - pointwise ordering is instance of class order with standard syntax
   598     <= and <;
   599   - multiset ordering has syntax <=# and <#; partial order properties
   600     are provided by means of interpretation with prefix
   601     multiset_order;
   602   - less duplication, less historical organization of sections,
   603     conversion from associations lists to multisets, rudimentary code
   604     generation;
   605   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   606     if needed.
   607 
   608 Renamed:
   609 
   610   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   611   multi_count_ext  ~>  multiset_ext
   612   diff_union_inverse2  ~>  diff_union_cancelR
   613 
   614 INCOMPATIBILITY.
   615 
   616 * Theory Permutation: replaced local "remove" by List.remove1.
   617 
   618 * Code generation: ML and OCaml code is decorated with signatures.
   619 
   620 * Theory List: added transpose.
   621 
   622 * Library/Nat_Bijection.thy is a collection of bijective functions
   623 between nat and other types, which supersedes the older libraries
   624 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   625 
   626   Constants:
   627   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   628   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   629   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   630   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   631   Countable.pair_encode           ~> prod_encode
   632   NatIso.prod2nat                 ~> prod_encode
   633   NatIso.nat2prod                 ~> prod_decode
   634   NatIso.sum2nat                  ~> sum_encode
   635   NatIso.nat2sum                  ~> sum_decode
   636   NatIso.list2nat                 ~> list_encode
   637   NatIso.nat2list                 ~> list_decode
   638   NatIso.set2nat                  ~> set_encode
   639   NatIso.nat2set                  ~> set_decode
   640 
   641   Lemmas:
   642   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   643   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   644   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   645   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   646   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   647   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   648   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   649   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   650   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   651   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   652   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   653   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   654   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   655 
   656 * Sledgehammer:
   657   - Renamed ATP commands:
   658     atp_info     ~> sledgehammer running_atps
   659     atp_kill     ~> sledgehammer kill_atps
   660     atp_messages ~> sledgehammer messages
   661     atp_minimize ~> sledgehammer minimize
   662     print_atps   ~> sledgehammer available_atps
   663     INCOMPATIBILITY.
   664   - Added user's manual ("isabelle doc sledgehammer").
   665   - Added option syntax and "sledgehammer_params" to customize
   666     Sledgehammer's behavior.  See the manual for details.
   667   - Modified the Isar proof reconstruction code so that it produces
   668     direct proofs rather than proofs by contradiction.  (This feature
   669     is still experimental.)
   670   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   671     full-typed mode.
   672   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   673 
   674 * Nitpick:
   675   - Added and implemented "binary_ints" and "bits" options.
   676   - Added "std" option and implemented support for nonstandard models.
   677   - Added and implemented "finitize" option to improve the precision
   678     of infinite datatypes based on a monotonicity analysis.
   679   - Added support for quotient types.
   680   - Added support for "specification" and "ax_specification"
   681     constructs.
   682   - Added support for local definitions (for "function" and
   683     "termination" proofs).
   684   - Added support for term postprocessors.
   685   - Optimized "Multiset.multiset" and "FinFun.finfun".
   686   - Improved efficiency of "destroy_constrs" optimization.
   687   - Fixed soundness bugs related to "destroy_constrs" optimization and
   688     record getters.
   689   - Fixed soundness bug related to higher-order constructors.
   690   - Fixed soundness bug when "full_descrs" is enabled.
   691   - Improved precision of set constructs.
   692   - Added "atoms" option.
   693   - Added cache to speed up repeated Kodkod invocations on the same
   694     problems.
   695   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   696     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   697     "SAT4J_Light".  INCOMPATIBILITY.
   698   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   699     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   700   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   701 
   702 * Method "induct" now takes instantiations of the form t, where t is not
   703   a variable, as a shorthand for "x == t", where x is a fresh variable.
   704   If this is not intended, t has to be enclosed in parentheses.
   705   By default, the equalities generated by definitional instantiations
   706   are pre-simplified, which may cause parameters of inductive cases
   707   to disappear, or may even delete some of the inductive cases.
   708   Use "induct (no_simp)" instead of "induct" to restore the old
   709   behaviour. The (no_simp) option is also understood by the "cases"
   710   and "nominal_induct" methods, which now perform pre-simplification, too.
   711   INCOMPATIBILITY.
   712 
   713 
   714 *** HOLCF ***
   715 
   716 * Variable names in lemmas generated by the domain package have
   717 changed; the naming scheme is now consistent with the HOL datatype
   718 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   719 
   720 * The domain package no longer defines the function "foo_copy" for
   721 recursive domain "foo".  The reach lemma is now stated directly in
   722 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   723 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   724 
   725 * Most definedness lemmas generated by the domain package (previously
   726 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   727 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   728 Proofs that used definedness lemmas as intro rules may break,
   729 potential INCOMPATIBILITY.
   730 
   731 * Induction and casedist rules generated by the domain package now
   732 declare proper case_names (one called "bottom", and one named for each
   733 constructor).  INCOMPATIBILITY.
   734 
   735 * For mutually-recursive domains, separate "reach" and "take_lemma"
   736 rules are generated for each domain, INCOMPATIBILITY.
   737 
   738   foo_bar.reach       ~> foo.reach  bar.reach
   739   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   740 
   741 * Some lemmas generated by the domain package have been renamed for
   742 consistency with the datatype package, INCOMPATIBILITY.
   743 
   744   foo.ind        ~> foo.induct
   745   foo.finite_ind ~> foo.finite_induct
   746   foo.coind      ~> foo.coinduct
   747   foo.casedist   ~> foo.exhaust
   748   foo.exhaust    ~> foo.nchotomy
   749 
   750 * For consistency with other definition packages, the fixrec package
   751 now generates qualified theorem names, INCOMPATIBILITY.
   752 
   753   foo_simps  ~> foo.simps
   754   foo_unfold ~> foo.unfold
   755   foo_induct ~> foo.induct
   756 
   757 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   758 method and internal fixrec proofs now use the default simpset instead.
   759 INCOMPATIBILITY.
   760 
   761 * The "contlub" predicate has been removed.  Proof scripts should use
   762 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   763 
   764 * The "admw" predicate has been removed, INCOMPATIBILITY.
   765 
   766 * The constants cpair, cfst, and csnd have been removed in favor of
   767 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   768 
   769 
   770 *** ML ***
   771 
   772 * Antiquotations for basic formal entities:
   773 
   774     @{class NAME}         -- type class
   775     @{class_syntax NAME}  -- syntax representation of the above
   776 
   777     @{type_name NAME}     -- logical type
   778     @{type_abbrev NAME}   -- type abbreviation
   779     @{nonterminal NAME}   -- type of concrete syntactic category
   780     @{type_syntax NAME}   -- syntax representation of any of the above
   781 
   782     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   783     @{const_abbrev NAME}  -- abbreviated constant
   784     @{const_syntax NAME}  -- syntax representation of any of the above
   785 
   786 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   787 syntax constant (cf. 'syntax' command).
   788 
   789 * Antiquotation @{make_string} inlines a function to print arbitrary
   790 values similar to the ML toplevel.  The result is compiler dependent
   791 and may fall back on "?" in certain situations.
   792 
   793 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   794 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   795 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   796 not work with the asynchronous Isar document model.
   797 
   798 * Configuration options now admit dynamic default values, depending on
   799 the context or even global references.
   800 
   801 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   802 uses an efficient external library if available (for Poly/ML).
   803 
   804 * Renamed some important ML structures, while keeping the old names
   805 for some time as aliases within the structure Legacy:
   806 
   807   OuterKeyword  ~>  Keyword
   808   OuterLex      ~>  Token
   809   OuterParse    ~>  Parse
   810   OuterSyntax   ~>  Outer_Syntax
   811   PrintMode     ~>  Print_Mode
   812   SpecParse     ~>  Parse_Spec
   813   ThyInfo       ~>  Thy_Info
   814   ThyLoad       ~>  Thy_Load
   815   ThyOutput     ~>  Thy_Output
   816   TypeInfer     ~>  Type_Infer
   817 
   818 Note that "open Legacy" simplifies porting of sources, but forgetting
   819 to remove it again will complicate porting again in the future.
   820 
   821 * Most operations that refer to a global context are named
   822 accordingly, e.g. Simplifier.global_context or
   823 ProofContext.init_global.  There are some situations where a global
   824 context actually works, but under normal circumstances one needs to
   825 pass the proper local context through the code!
   826 
   827 * Discontinued old TheoryDataFun with its copy/init operation -- data
   828 needs to be pure.  Functor Theory_Data_PP retains the traditional
   829 Pretty.pp argument to merge, which is absent in the standard
   830 Theory_Data version.
   831 
   832 * Sorts.certify_sort and derived "cert" operations for types and terms
   833 no longer minimize sorts.  Thus certification at the boundary of the
   834 inference kernel becomes invariant under addition of class relations,
   835 which is an important monotonicity principle.  Sorts are now minimized
   836 in the syntax layer only, at the boundary between the end-user and the
   837 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   838 explicitly in rare situations.
   839 
   840 * Renamed old-style Drule.standard to Drule.export_without_context, to
   841 emphasize that this is in no way a standard operation.
   842 INCOMPATIBILITY.
   843 
   844 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   845 usual for resolution.  Rare INCOMPATIBILITY.
   846 
   847 * Renamed varify/unvarify operations to varify_global/unvarify_global
   848 to emphasize that these only work in a global situation (which is
   849 quite rare).
   850 
   851 * Curried take and drop in library.ML; negative length is interpreted
   852 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   853 
   854 * Proof terms: type substitutions on proof constants now use canonical
   855 order of type variables.  INCOMPATIBILITY for tools working with proof
   856 terms.
   857 
   858 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   859 may no longer carry premises.  User-level specifications are
   860 transformed accordingly by Thm.add_axiom/add_def.
   861 
   862 
   863 *** System ***
   864 
   865 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   866 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   867 proof terms are enabled unconditionally in the new HOL-Proofs image.
   868 
   869 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   870 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   871 respectively.
   872 
   873 * Old lib/scripts/polyml-platform is superseded by the
   874 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   875 variant, even on a 64 bit machine.  The following example setting
   876 prefers 64 bit if available:
   877 
   878   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   879 
   880 * The preliminary Isabelle/jEdit application demonstrates the emerging
   881 Isabelle/Scala layer for advanced prover interaction and integration.
   882 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   883 component.
   884 
   885 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   886 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   887 similar to the default assignment of the document preparation system
   888 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   889 provides some operations for direct access to the font without asking
   890 the user for manual installation.
   891 
   892 
   893 
   894 New in Isabelle2009-1 (December 2009)
   895 -------------------------------------
   896 
   897 *** General ***
   898 
   899 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   900 one backslash should be used, even in ML sources.
   901 
   902 
   903 *** Pure ***
   904 
   905 * Locale interpretation propagates mixins along the locale hierarchy.
   906 The currently only available mixins are the equations used to map
   907 local definitions to terms of the target domain of an interpretation.
   908 
   909 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   910 loc" to print all interpretations of locale "loc" in the theory.
   911 Interpretations in proofs are not shown.
   912 
   913 * Thoroughly revised locales tutorial.  New section on conditional
   914 interpretation.
   915 
   916 * On instantiation of classes, remaining undefined class parameters
   917 are formally declared.  INCOMPATIBILITY.
   918 
   919 
   920 *** Document preparation ***
   921 
   922 * New generalized style concept for printing terms: @{foo (style) ...}
   923 instead of @{foo_style style ...}  (old form is still retained for
   924 backward compatibility).  Styles can be also applied for
   925 antiquotations prop, term_type and typeof.
   926 
   927 
   928 *** HOL ***
   929 
   930 * New proof method "smt" for a combination of first-order logic with
   931 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   932 fixed-size bitvectors; there is also basic support for higher-order
   933 features (esp. lambda abstractions).  It is an incomplete decision
   934 procedure based on external SMT solvers using the oracle mechanism;
   935 for the SMT solver Z3, this method is proof-producing.  Certificates
   936 are provided to avoid calling the external solvers solely for
   937 re-checking proofs.  Due to a remote SMT service there is no need for
   938 installing SMT solvers locally.  See src/HOL/SMT.
   939 
   940 * New commands to load and prove verification conditions generated by
   941 the Boogie program verifier or derived systems (e.g. the Verifying C
   942 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   943 
   944 * New counterexample generator tool 'nitpick' based on the Kodkod
   945 relational model finder.  See src/HOL/Tools/Nitpick and
   946 src/HOL/Nitpick_Examples.
   947 
   948 * New commands 'code_pred' and 'values' to invoke the predicate
   949 compiler and to enumerate values of inductive predicates.
   950 
   951 * A tabled implementation of the reflexive transitive closure.
   952 
   953 * New implementation of quickcheck uses generic code generator;
   954 default generators are provided for all suitable HOL types, records
   955 and datatypes.  Old quickcheck can be re-activated importing theory
   956 Library/SML_Quickcheck.
   957 
   958 * New testing tool Mirabelle for automated proof tools.  Applies
   959 several tools and tactics like sledgehammer, metis, or quickcheck, to
   960 every proof step in a theory.  To be used in batch mode via the
   961 "mirabelle" utility.
   962 
   963 * New proof method "sos" (sum of squares) for nonlinear real
   964 arithmetic (originally due to John Harison). It requires theory
   965 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   966 works well in practice on quantifier-free real arithmetic with +, -,
   967 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   968 inequalities between polynomials.  It makes use of external
   969 semidefinite programming solvers.  Method "sos" generates a
   970 certificate that can be pasted into the proof thus avoiding the need
   971 to call an external tool every time the proof is checked.  See
   972 src/HOL/Library/Sum_Of_Squares.
   973 
   974 * New method "linarith" invokes existing linear arithmetic decision
   975 procedure only.
   976 
   977 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   978 
   979 * New Sledgehammer option "Full Types" in Proof General settings menu.
   980 Causes full type information to be output to the ATPs.  This slows
   981 ATPs down considerably but eliminates a source of unsound "proofs"
   982 that fail later.
   983 
   984 * New method "metisFT": A version of metis that uses full type
   985 information in order to avoid failures of proof reconstruction.
   986 
   987 * New evaluator "approximate" approximates an real valued term using
   988 the same method as the approximation method.
   989 
   990 * Method "approximate" now supports arithmetic expressions as
   991 boundaries of intervals and implements interval splitting and Taylor
   992 series expansion.
   993 
   994 * ML antiquotation @{code_datatype} inserts definition of a datatype
   995 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   996 
   997 * New theory SupInf of the supremum and infimum operators for sets of
   998 reals.
   999 
  1000 * New theory Probability, which contains a development of measure
  1001 theory, eventually leading to Lebesgue integration and probability.
  1002 
  1003 * Extended Multivariate Analysis to include derivation and Brouwer's
  1004 fixpoint theorem.
  1005 
  1006 * Reorganization of number theory, INCOMPATIBILITY:
  1007   - new number theory development for nat and int, in theories Divides
  1008     and GCD as well as in new session Number_Theory
  1009   - some constants and facts now suffixed with _nat and _int
  1010     accordingly
  1011   - former session NumberTheory now named Old_Number_Theory, including
  1012     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1013   - moved theory Pocklington from src/HOL/Library to
  1014     src/HOL/Old_Number_Theory
  1015 
  1016 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1017 lcm of finite and infinite sets. It is shown that they form a complete
  1018 lattice.
  1019 
  1020 * Class semiring_div requires superclass no_zero_divisors and proof of
  1021 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1022 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1023 generalized to class semiring_div, subsuming former theorems
  1024 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1025 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1026 INCOMPATIBILITY.
  1027 
  1028 * Refinements to lattice classes and sets:
  1029   - less default intro/elim rules in locale variant, more default
  1030     intro/elim rules in class variant: more uniformity
  1031   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1032     le_inf_iff
  1033   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1034     sup_aci)
  1035   - renamed ACI to inf_sup_aci
  1036   - new class "boolean_algebra"
  1037   - class "complete_lattice" moved to separate theory
  1038     "Complete_Lattice"; corresponding constants (and abbreviations)
  1039     renamed and with authentic syntax:
  1040     Set.Inf ~>    Complete_Lattice.Inf
  1041     Set.Sup ~>    Complete_Lattice.Sup
  1042     Set.INFI ~>   Complete_Lattice.INFI
  1043     Set.SUPR ~>   Complete_Lattice.SUPR
  1044     Set.Inter ~>  Complete_Lattice.Inter
  1045     Set.Union ~>  Complete_Lattice.Union
  1046     Set.INTER ~>  Complete_Lattice.INTER
  1047     Set.UNION ~>  Complete_Lattice.UNION
  1048   - authentic syntax for
  1049     Set.Pow
  1050     Set.image
  1051   - mere abbreviations:
  1052     Set.empty               (for bot)
  1053     Set.UNIV                (for top)
  1054     Set.inter               (for inf, formerly Set.Int)
  1055     Set.union               (for sup, formerly Set.Un)
  1056     Complete_Lattice.Inter  (for Inf)
  1057     Complete_Lattice.Union  (for Sup)
  1058     Complete_Lattice.INTER  (for INFI)
  1059     Complete_Lattice.UNION  (for SUPR)
  1060   - object-logic definitions as far as appropriate
  1061 
  1062 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1063 Un_subset_iff are explicitly deleted as default simp rules; then also
  1064 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1065 deleted to achieve the desired effect.
  1066 
  1067 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1068 rules by default any longer; the same applies to min_max.inf_absorb1
  1069 etc.  INCOMPATIBILITY.
  1070 
  1071 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1072 pred_set_conv by default.  INCOMPATIBILITY.
  1073 
  1074 * Power operations on relations and functions are now one dedicated
  1075 constant "compow" with infix syntax "^^".  Power operation on
  1076 multiplicative monoids retains syntax "^" and is now defined generic
  1077 in class power.  INCOMPATIBILITY.
  1078 
  1079 * Relation composition "R O S" now has a more standard argument order:
  1080 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1081 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1082 break, since the O_assoc rule was not rewritten like this.  Fix using
  1083 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1084 
  1085 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1086 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1087 INCOMPATIBILITY.
  1088 
  1089 * Most rules produced by inductive and datatype package have mandatory
  1090 prefixes.  INCOMPATIBILITY.
  1091 
  1092 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1093 the attribute of the same name.  Each of the theorems in the list
  1094 DERIV_intros assumes composition with an additional function and
  1095 matches a variable to the derivative, which has to be solved by the
  1096 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1097 of most elementary terms.  Former Maclauren.DERIV_tac and
  1098 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1099 INCOMPATIBILITY.
  1100 
  1101 * Code generator attributes follow the usual underscore convention:
  1102     code_unfold     replaces    code unfold
  1103     code_post       replaces    code post
  1104     etc.
  1105   INCOMPATIBILITY.
  1106 
  1107 * Renamed methods:
  1108     sizechange -> size_change
  1109     induct_scheme -> induction_schema
  1110   INCOMPATIBILITY.
  1111 
  1112 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1113 INCOMPATIBILITY, use "undefined" directly.
  1114 
  1115 * Renamed theorems:
  1116     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1117     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1118     Suc_plus1 -> Suc_eq_plus1
  1119     *anti_sym -> *antisym*
  1120     vector_less_eq_def -> vector_le_def
  1121   INCOMPATIBILITY.
  1122 
  1123 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1124 INCOMPATIBILITY.
  1125 
  1126 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1127 INCOMPATIBILITY.
  1128 
  1129 
  1130 *** HOLCF ***
  1131 
  1132 * Theory Representable defines a class "rep" of domains that are
  1133 representable (via an ep-pair) in the universal domain type "udom".
  1134 Instances are provided for all type constructors defined in HOLCF.
  1135 
  1136 * The 'new_domain' command is a purely definitional version of the
  1137 domain package, for representable domains.  Syntax is identical to the
  1138 old domain package.  The 'new_domain' package also supports indirect
  1139 recursion using previously-defined type constructors.  See
  1140 src/HOLCF/ex/New_Domain.thy for examples.
  1141 
  1142 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1143 on the left-hand side of an equation, and then performs
  1144 simplification.  Rewriting is done using rules declared with the
  1145 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1146 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1147 
  1148 * The pattern-match compiler in 'fixrec' can now handle constructors
  1149 with HOL function types.  Pattern-match combinators for the Pair
  1150 constructor are pre-configured.
  1151 
  1152 * The 'fixrec' package now produces better fixed-point induction rules
  1153 for mutually-recursive definitions:  Induction rules have conclusions
  1154 of the form "P foo bar" instead of "P <foo, bar>".
  1155 
  1156 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1157 been renamed to "below".  The name "below" now replaces "less" in many
  1158 theorem names.  (Legacy theorem names using "less" are still supported
  1159 as well.)
  1160 
  1161 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1162 patterns can be used to generate strictness rules, or to make
  1163 functions more strict (much like the bang-patterns supported by the
  1164 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1165 examples.
  1166 
  1167 
  1168 *** ML ***
  1169 
  1170 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1171 errors and run-time exceptions, including detailed source positions.
  1172 
  1173 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1174 identified entries, with some additional information such as source
  1175 position, logical grouping etc.
  1176 
  1177 * Theory and context data is now introduced by the simplified and
  1178 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1179 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1180 copy operation) is still available for some time.
  1181 
  1182 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1183 provides a high-level programming interface to synchronized state
  1184 variables with atomic update.  This works via pure function
  1185 application within a critical section -- its runtime should be as
  1186 short as possible; beware of deadlocks if critical code is nested,
  1187 either directly or indirectly via other synchronized variables!
  1188 
  1189 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1190 wraps raw ML references, explicitly indicating their non-thread-safe
  1191 behaviour.  The Isar toplevel keeps this structure open, to
  1192 accommodate Proof General as well as quick and dirty interactive
  1193 experiments with references.
  1194 
  1195 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1196 parallel tactical reasoning.
  1197 
  1198 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1199 are similar to SUBPROOF, but are slightly more flexible: only the
  1200 specified parts of the subgoal are imported into the context, and the
  1201 body tactic may introduce new subgoals and schematic variables.
  1202 
  1203 * Old tactical METAHYPS, which does not observe the proof context, has
  1204 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1205 or Subgoal.FOCUS etc.
  1206 
  1207 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1208 functors have their own ML name space there is no point to mark them
  1209 separately.)  Minor INCOMPATIBILITY.
  1210 
  1211 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1212 
  1213 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1214 INCOMPATIBILITY.
  1215 
  1216 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1217 mode, which avoids critical setmp.
  1218 
  1219 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1220 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1221 Attrib/Method.setup introduced in Isabelle2009.
  1222 
  1223 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1224 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1225 last resort.  INCOMPATIBILITY.
  1226 
  1227 * Display.pretty_thm now requires a proper context (cf. former
  1228 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1229 or even Display.pretty_thm_without_context as last resort.
  1230 INCOMPATIBILITY.
  1231 
  1232 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1233 Syntax.pretty_typ/term directly, preferably with proper context
  1234 instead of global theory.
  1235 
  1236 
  1237 *** System ***
  1238 
  1239 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1240 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1241 usedir option -q.
  1242 
  1243 * Support for additional "Isabelle components" via etc/components, see
  1244 also the system manual.
  1245 
  1246 * The isabelle makeall tool now operates on all components with
  1247 IsaMakefile, not just hardwired "logics".
  1248 
  1249 * Removed "compress" option from isabelle-process and isabelle usedir;
  1250 this is always enabled.
  1251 
  1252 * Discontinued support for Poly/ML 4.x versions.
  1253 
  1254 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1255 on a given logic image.  This requires the lighttpd webserver and is
  1256 currently supported on Linux only.
  1257 
  1258 
  1259 
  1260 New in Isabelle2009 (April 2009)
  1261 --------------------------------
  1262 
  1263 *** General ***
  1264 
  1265 * Simplified main Isabelle executables, with less surprises on
  1266 case-insensitive file-systems (such as Mac OS).
  1267 
  1268   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1269     "isatool."
  1270 
  1271   - The former "isabelle" alias for "isabelle-process" has been
  1272     removed (should rarely occur to regular users).
  1273 
  1274   - The former "isabelle-interface" and its alias "Isabelle" have been
  1275     removed (interfaces are now regular Isabelle tools).
  1276 
  1277 Within scripts and make files, the Isabelle environment variables
  1278 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1279 respectively.  (The latter are still available as legacy feature.)
  1280 
  1281 The old isabelle-interface wrapper could react in confusing ways if
  1282 the interface was uninstalled or changed otherwise.  Individual
  1283 interface tool configuration is now more explicit, see also the
  1284 Isabelle system manual.  In particular, Proof General is now available
  1285 via "isabelle emacs".
  1286 
  1287 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1288 purge installed copies of Isabelle executables and re-run "isabelle
  1289 install -p ...", or use symlinks.
  1290 
  1291 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1292 old ~/isabelle, which was slightly non-standard and apt to cause
  1293 surprises on case-insensitive file-systems (such as Mac OS).
  1294 
  1295 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1296 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1297 care is required when using older releases of Isabelle.  Note that
  1298 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1299 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1300 
  1301 * Proofs of fully specified statements are run in parallel on
  1302 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1303 a regular 4-core machine, if the initial heap space is made reasonably
  1304 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1305 
  1306 * The main reference manuals ("isar-ref", "implementation", and
  1307 "system") have been updated and extended.  Formally checked references
  1308 as hyperlinks are now available uniformly.
  1309 
  1310 
  1311 *** Pure ***
  1312 
  1313 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1314 respects.  The most important changes are listed below.  See the
  1315 Tutorial on Locales ("locales" manual) for details.
  1316 
  1317 - In locale expressions, instantiation replaces renaming.  Parameters
  1318 must be declared in a for clause.  To aid compatibility with previous
  1319 parameter inheritance, in locale declarations, parameters that are not
  1320 'touched' (instantiation position "_" or omitted) are implicitly added
  1321 with their syntax at the beginning of the for clause.
  1322 
  1323 - Syntax from abbreviations and definitions in locales is available in
  1324 locale expressions and context elements.  The latter is particularly
  1325 useful in locale declarations.
  1326 
  1327 - More flexible mechanisms to qualify names generated by locale
  1328 expressions.  Qualifiers (prefixes) may be specified in locale
  1329 expressions, and can be marked as mandatory (syntax: "name!:") or
  1330 optional (syntax "name?:").  The default depends for plain "name:"
  1331 depends on the situation where a locale expression is used: in
  1332 commands 'locale' and 'sublocale' prefixes are optional, in
  1333 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1334 implicit qualifiers derived from the parameter names of a locale are
  1335 no longer generated.
  1336 
  1337 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1338 instantiation clause in "interpretation" and "interpret" (square
  1339 brackets) is no longer available.  Use locale expressions.
  1340 
  1341 - When converting proof scripts, mandatory qualifiers in
  1342 'interpretation' and 'interpret' should be retained by default, even
  1343 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1344 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1345 in locale expressions range over a single locale instance only.
  1346 
  1347 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1348 In existing theorem specifications replace the includes element by the
  1349 respective context elements of the included locale, omitting those
  1350 that are already present in the theorem specification.  Multiple
  1351 assume elements of a locale should be replaced by a single one
  1352 involving the locale predicate.  In the proof body, declarations (most
  1353 notably theorems) may be regained by interpreting the respective
  1354 locales in the proof context as required (command "interpret").
  1355 
  1356 If using "includes" in replacement of a target solely because the
  1357 parameter types in the theorem are not as general as in the target,
  1358 consider declaring a new locale with additional type constraints on
  1359 the parameters (context element "constrains").
  1360 
  1361 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1362 
  1363 - Locale interpretation commands no longer attempt to simplify goal.
  1364 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1365 methods intro_locales and unfold_locales to clarify.
  1366 
  1367 - Locale interpretation commands no longer accept interpretation
  1368 attributes.  INCOMPATIBILITY.
  1369 
  1370 * Class declaration: so-called "base sort" must not be given in import
  1371 list any longer, but is inferred from the specification.  Particularly
  1372 in HOL, write
  1373 
  1374     class foo = ...
  1375 
  1376 instead of
  1377 
  1378     class foo = type + ...
  1379 
  1380 * Class target: global versions of theorems stemming do not carry a
  1381 parameter prefix any longer.  INCOMPATIBILITY.
  1382 
  1383 * Class 'instance' command no longer accepts attached definitions.
  1384 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1385 
  1386 * Recovered hiding of consts, which was accidentally broken in
  1387 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1388 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1389 
  1390 * Slightly more coherent Pure syntax, with updated documentation in
  1391 isar-ref manual.  Removed locales meta_term_syntax and
  1392 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1393 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1394 directly in regular applications.
  1395 
  1396 * There is a new syntactic category "float_const" for signed decimal
  1397 fractions (e.g. 123.45 or -123.45).
  1398 
  1399 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1400 interface with 'setup' command instead.
  1401 
  1402 * Command 'local_setup' is similar to 'setup', but operates on a local
  1403 theory context.
  1404 
  1405 * The 'axiomatization' command now only works within a global theory
  1406 context.  INCOMPATIBILITY.
  1407 
  1408 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1409 hypotheses.  Sorts required in the course of reasoning need to be
  1410 covered by the constraints in the initial statement, completed by the
  1411 type instance information of the background theory.  Non-trivial sort
  1412 hypotheses, which rarely occur in practice, may be specified via
  1413 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1414 
  1415   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1416 
  1417 The result contains an implicit sort hypotheses as before --
  1418 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1419 normalization.
  1420 
  1421 * Generalized Isar history, with support for linear undo, direct state
  1422 addressing etc.
  1423 
  1424 * Changed defaults for unify configuration options:
  1425 
  1426   unify_trace_bound = 50 (formerly 25)
  1427   unify_search_bound = 60 (formerly 30)
  1428 
  1429 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1430 
  1431   a) On theory merge, the last set of code equations for a particular
  1432      constant is taken (in accordance with the policy applied by other
  1433      parts of the code generator framework).
  1434 
  1435   b) Code equations stemming from explicit declarations (e.g. code
  1436      attribute) gain priority over default code equations stemming
  1437      from definition, primrec, fun etc.
  1438 
  1439 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1440 
  1441 * Unified theorem tables for both code generators.  Thus [code
  1442 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1443 
  1444 * Command 'find_consts' searches for constants based on type and name
  1445 patterns, e.g.
  1446 
  1447     find_consts "_ => bool"
  1448 
  1449 By default, matching is against subtypes, but it may be restricted to
  1450 the whole type.  Searching by name is possible.  Multiple queries are
  1451 conjunctive and queries may be negated by prefixing them with a
  1452 hyphen:
  1453 
  1454     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1455 
  1456 * New 'find_theorems' criterion "solves" matches theorems that
  1457 directly solve the current goal (modulo higher-order unification).
  1458 
  1459 * Auto solve feature for main theorem statements: whenever a new goal
  1460 is stated, "find_theorems solves" is called; any theorems that could
  1461 solve the lemma directly are listed as part of the goal state.
  1462 Cf. associated options in Proof General Isabelle settings menu,
  1463 enabled by default, with reasonable timeout for pathological cases of
  1464 higher-order unification.
  1465 
  1466 
  1467 *** Document preparation ***
  1468 
  1469 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1470 demanding keyword 'by' and supporting the full method expression
  1471 syntax just like the Isar command 'by'.
  1472 
  1473 
  1474 *** HOL ***
  1475 
  1476 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1477 points Main and Complex_Main remain as before.
  1478 
  1479 * Logic image HOL-Plain provides a minimal HOL with the most important
  1480 tools available (inductive, datatype, primrec, ...).  This facilitates
  1481 experimentation and tool development.  Note that user applications
  1482 (and library theories) should never refer to anything below theory
  1483 Main, as before.
  1484 
  1485 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1486 experimentation due to shorter build times.
  1487 
  1488 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1489 were previously part of former HOL-Complex.  Entry point Hyperreal
  1490 remains valid, but theories formerly using Complex_Main should now use
  1491 new entry point Hypercomplex.
  1492 
  1493 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1494 Posix processes.  Avoids potentially expensive forking of the ML
  1495 process.  New thread-based implementation also works on non-Unix
  1496 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1497 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1498 commands are covered in the isar-ref manual.
  1499 
  1500 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1501 sledgehammer without local ATP installation (Vampire etc.). Other
  1502 provers may be included via suitable ML wrappers, see also
  1503 src/HOL/ATP_Linkup.thy.
  1504 
  1505 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1506 menu.
  1507 
  1508 * The metis method no longer fails because the theorem is too trivial
  1509 (contains the empty clause).
  1510 
  1511 * The metis method now fails in the usual manner, rather than raising
  1512 an exception, if it determines that it cannot prove the theorem.
  1513 
  1514 * Method "coherent" implements a prover for coherent logic (see also
  1515 src/Tools/coherent.ML).
  1516 
  1517 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1518 "undefined" is the right choice to replace "arbitrary", though
  1519 logically there is no difference.  INCOMPATIBILITY.
  1520 
  1521 * Command "value" now integrates different evaluation mechanisms.  The
  1522 result of the first successful evaluation mechanism is printed.  In
  1523 square brackets a particular named evaluation mechanisms may be
  1524 specified (currently, [SML], [code] or [nbe]).  See further
  1525 src/HOL/ex/Eval_Examples.thy.
  1526 
  1527 * Normalization by evaluation now allows non-leftlinear equations.
  1528 Declare with attribute [code nbe].
  1529 
  1530 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1531 as the structured Isar versions "cases" and "induct", cf. the
  1532 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1533 are now presented as a list of individual projections
  1534 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1535 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1536 rare situations a different rule is selected --- notably nested tuple
  1537 elimination instead of former prod.exhaust: use explicit (case_tac t
  1538 rule: prod.exhaust) here.
  1539 
  1540 * Attributes "cases", "induct", "coinduct" support "del" option.
  1541 
  1542 * Removed fact "case_split_thm", which duplicates "case_split".
  1543 
  1544 * The option datatype has been moved to a new theory Option.  Renamed
  1545 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1546 
  1547 * New predicate "strict_mono" classifies strict functions on partial
  1548 orders.  With strict functions on linear orders, reasoning about
  1549 (in)equalities is facilitated by theorems "strict_mono_eq",
  1550 "strict_mono_less_eq" and "strict_mono_less".
  1551 
  1552 * Some set operations are now proper qualified constants with
  1553 authentic syntax.  INCOMPATIBILITY:
  1554 
  1555     op Int ~>   Set.Int
  1556     op Un ~>    Set.Un
  1557     INTER ~>    Set.INTER
  1558     UNION ~>    Set.UNION
  1559     Inter ~>    Set.Inter
  1560     Union ~>    Set.Union
  1561     {} ~>       Set.empty
  1562     UNIV ~>     Set.UNIV
  1563 
  1564 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1565 theory Set.
  1566 
  1567 * Auxiliary class "itself" has disappeared -- classes without any
  1568 parameter are treated as expected by the 'class' command.
  1569 
  1570 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1571 
  1572 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1573 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1574 
  1575 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1576 method "approximation".  It proves formulas on real values by using
  1577 interval arithmetic.  In the formulas are also the transcendental
  1578 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1579 allowed. For examples see
  1580 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1581 
  1582 * Theory "Reflection" now resides in HOL/Library.
  1583 
  1584 * Entry point to Word library now simply named "Word".
  1585 INCOMPATIBILITY.
  1586 
  1587 * Made source layout more coherent with logical distribution
  1588 structure:
  1589 
  1590     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1591     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1592     src/HOL/Library/GCD.thy ~> src/HOL/
  1593     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1594     src/HOL/Library/Parity.thy ~> src/HOL/
  1595     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1596     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1597     src/HOL/Real/Lubs.thy ~> src/HOL/
  1598     src/HOL/Real/PReal.thy ~> src/HOL/
  1599     src/HOL/Real/Rational.thy ~> src/HOL/
  1600     src/HOL/Real/RComplete.thy ~> src/HOL/
  1601     src/HOL/Real/RealDef.thy ~> src/HOL/
  1602     src/HOL/Real/RealPow.thy ~> src/HOL/
  1603     src/HOL/Real/Real.thy ~> src/HOL/
  1604     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1605     src/HOL/Complex/Complex.thy ~> src/HOL/
  1606     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1607     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1608     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1609     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1610     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1611     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1612     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1613     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1614     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1615     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1616     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1617     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1618     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1619     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1620     src/HOL/Real/Float ~> src/HOL/Library/
  1621     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1622     src/HOL/Real/RealVector.thy ~> src/HOL/
  1623 
  1624     src/HOL/arith_data.ML ~> src/HOL/Tools
  1625     src/HOL/hologic.ML ~> src/HOL/Tools
  1626     src/HOL/simpdata.ML ~> src/HOL/Tools
  1627     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1628     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1629     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1630     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1631     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1632     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1633     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1634 
  1635     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1636     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1637     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1638     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1639     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1640     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1641 
  1642 * If methods "eval" and "evaluation" encounter a structured proof
  1643 state with !!/==>, only the conclusion is evaluated to True (if
  1644 possible), avoiding strange error messages.
  1645 
  1646 * Method "sizechange" automates termination proofs using (a
  1647 modification of) the size-change principle.  Requires SAT solver.  See
  1648 src/HOL/ex/Termination.thy for examples.
  1649 
  1650 * Simplifier: simproc for let expressions now unfolds if bound
  1651 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1652 
  1653 * Method "arith": Linear arithmetic now ignores all inequalities when
  1654 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1655 
  1656 * New attribute "arith" for facts that should always be used
  1657 automatically by arithmetic. It is intended to be used locally in
  1658 proofs, e.g.
  1659 
  1660   assumes [arith]: "x > 0"
  1661 
  1662 Global usage is discouraged because of possible performance impact.
  1663 
  1664 * New classes "top" and "bot" with corresponding operations "top" and
  1665 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1666 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1667 
  1668 * Changed definition lemma "less_fun_def" in order to provide an
  1669 instance for preorders on functions; use lemma "less_le" instead.
  1670 INCOMPATIBILITY.
  1671 
  1672 * Theory Orderings: class "wellorder" moved here, with explicit
  1673 induction rule "less_induct" as assumption.  For instantiation of
  1674 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1675 INCOMPATIBILITY.
  1676 
  1677 * Theory Orderings: added class "preorder" as superclass of "order".
  1678 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1679 etc. slightly changed.  Some theorems named order_class.* now named
  1680 preorder_class.*.
  1681 
  1682 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1683 "diag" to "Id_on".
  1684 
  1685 * Theory Finite_Set: added a new fold combinator of type
  1686 
  1687   ('a => 'b => 'b) => 'b => 'a set => 'b
  1688 
  1689 Occasionally this is more convenient than the old fold combinator
  1690 which is now defined in terms of the new one and renamed to
  1691 fold_image.
  1692 
  1693 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1694 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1695 extended with further lemmas!).  At the moment both still exist but
  1696 the former will disappear at some point.
  1697 
  1698 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1699 class recpower.  Type-specific simp rules for various recpower types
  1700 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1701 
  1702 rat_power_0    -> power_0
  1703 rat_power_Suc  -> power_Suc
  1704 realpow_0      -> power_0
  1705 realpow_Suc    -> power_Suc
  1706 complexpow_0   -> power_0
  1707 complexpow_Suc -> power_Suc
  1708 power_poly_0   -> power_0
  1709 power_poly_Suc -> power_Suc
  1710 
  1711 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1712 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1713 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1714 of lemmas from Divides has been generalized from nat to class
  1715 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1716 renames resulting from duplicate elimination:
  1717 
  1718     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1719     zero_dvd_iff ~>         dvd_0_left_iff
  1720     dvd_0 ~>                dvd_0_right
  1721     DIVISION_BY_ZERO_DIV ~> div_by_0
  1722     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1723     mult_div ~>             div_mult_self2_is_id
  1724     mult_mod ~>             mod_mult_self2_is_0
  1725 
  1726 * Theory IntDiv: removed many lemmas that are instances of class-based
  1727 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1728 rename old lemmas as follows:
  1729 
  1730 dvd_diff               -> nat_dvd_diff
  1731 dvd_zminus_iff         -> dvd_minus_iff
  1732 mod_add1_eq            -> mod_add_eq
  1733 mod_mult1_eq           -> mod_mult_right_eq
  1734 mod_mult1_eq'          -> mod_mult_left_eq
  1735 mod_mult_distrib_mod   -> mod_mult_eq
  1736 nat_mod_add_left_eq    -> mod_add_left_eq
  1737 nat_mod_add_right_eq   -> mod_add_right_eq
  1738 nat_mod_div_trivial    -> mod_div_trivial
  1739 nat_mod_mod_trivial    -> mod_mod_trivial
  1740 zdiv_zadd_self1        -> div_add_self1
  1741 zdiv_zadd_self2        -> div_add_self2
  1742 zdiv_zmult_self1       -> div_mult_self2_is_id
  1743 zdiv_zmult_self2       -> div_mult_self1_is_id
  1744 zdvd_triv_left         -> dvd_triv_left
  1745 zdvd_triv_right        -> dvd_triv_right
  1746 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1747 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1748 zmod_zadd_left_eq      -> mod_add_left_eq
  1749 zmod_zadd_right_eq     -> mod_add_right_eq
  1750 zmod_zadd_self1        -> mod_add_self1
  1751 zmod_zadd_self2        -> mod_add_self2
  1752 zmod_zadd1_eq          -> mod_add_eq
  1753 zmod_zdiff1_eq         -> mod_diff_eq
  1754 zmod_zdvd_zmod         -> mod_mod_cancel
  1755 zmod_zmod_cancel       -> mod_mod_cancel
  1756 zmod_zmult_self1       -> mod_mult_self2_is_0
  1757 zmod_zmult_self2       -> mod_mult_self1_is_0
  1758 zmod_1                 -> mod_by_1
  1759 zdiv_1                 -> div_by_1
  1760 zdvd_abs1              -> abs_dvd_iff
  1761 zdvd_abs2              -> dvd_abs_iff
  1762 zdvd_refl              -> dvd_refl
  1763 zdvd_trans             -> dvd_trans
  1764 zdvd_zadd              -> dvd_add
  1765 zdvd_zdiff             -> dvd_diff
  1766 zdvd_zminus_iff        -> dvd_minus_iff
  1767 zdvd_zminus2_iff       -> minus_dvd_iff
  1768 zdvd_zmultD            -> dvd_mult_right
  1769 zdvd_zmultD2           -> dvd_mult_left
  1770 zdvd_zmult_mono        -> mult_dvd_mono
  1771 zdvd_0_right           -> dvd_0_right
  1772 zdvd_0_left            -> dvd_0_left_iff
  1773 zdvd_1_left            -> one_dvd
  1774 zminus_dvd_iff         -> minus_dvd_iff
  1775 
  1776 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1777 
  1778 * The real numbers offer decimal input syntax: 12.34 is translated
  1779 into 1234/10^2. This translation is not reversed upon output.
  1780 
  1781 * Theory Library/Polynomial defines an abstract type 'a poly of
  1782 univariate polynomials with coefficients of type 'a.  In addition to
  1783 the standard ring operations, it also supports div and mod.  Code
  1784 generation is also supported, using list-style constructors.
  1785 
  1786 * Theory Library/Inner_Product defines a class of real_inner for real
  1787 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1788 => real.  Class real_inner is a subclass of real_normed_vector from
  1789 theory RealVector.
  1790 
  1791 * Theory Library/Product_Vector provides instances for the product
  1792 type 'a * 'b of several classes from RealVector and Inner_Product.
  1793 Definitions of addition, subtraction, scalar multiplication, norms,
  1794 and inner products are included.
  1795 
  1796 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1797 addition to the field operations, numerals and case syntax are also
  1798 supported.
  1799 
  1800 * Theory Library/Diagonalize provides constructive version of Cantor's
  1801 first diagonalization argument.
  1802 
  1803 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1804 zlcm (for int); carried together from various gcd/lcm developements in
  1805 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1806 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1807 may recover tupled syntax as follows:
  1808 
  1809     hide (open) const gcd
  1810     abbreviation gcd where
  1811       "gcd == (%(a, b). GCD.gcd a b)"
  1812     notation (output)
  1813       GCD.gcd ("gcd '(_, _')")
  1814 
  1815 The same works for lcm, zgcd, zlcm.
  1816 
  1817 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1818 instantiations for algebraic structures.  Removed some duplicate
  1819 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1820 
  1821 * ML antiquotation @{code} takes a constant as argument and generates
  1822 corresponding code in background and inserts name of the corresponding
  1823 resulting ML value/function/datatype constructor binding in place.
  1824 All occurrences of @{code} with a single ML block are generated
  1825 simultaneously.  Provides a generic and safe interface for
  1826 instrumentalizing code generation.  See
  1827 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1828 In future you ought to refrain from ad-hoc compiling generated SML
  1829 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1830 cannot refer to constants for which user-defined serializations are
  1831 set.  Refer to the corresponding ML counterpart directly in that
  1832 cases.
  1833 
  1834 * Command 'rep_datatype': instead of theorem names the command now
  1835 takes a list of terms denoting the constructors of the type to be
  1836 represented as datatype.  The characteristic theorems have to be
  1837 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1838 have disappeared in favour of existing ones:
  1839 
  1840     unit_induct                 ~> unit.induct
  1841     prod_induct                 ~> prod.induct
  1842     sum_induct                  ~> sum.induct
  1843     Suc_Suc_eq                  ~> nat.inject
  1844     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1845 
  1846 
  1847 *** HOL-Algebra ***
  1848 
  1849 * New locales for orders and lattices where the equivalence relation
  1850 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1851 locales use a record structure with field eq for the equivalence.
  1852 
  1853 * New theory of factorial domains.
  1854 
  1855 * Units_l_inv and Units_r_inv are now simp rules by default.
  1856 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1857 and/or r_inv will now also require deletion of these lemmas.
  1858 
  1859 * Renamed the following theorems, INCOMPATIBILITY:
  1860 
  1861 UpperD ~> Upper_memD
  1862 LowerD ~> Lower_memD
  1863 least_carrier ~> least_closed
  1864 greatest_carrier ~> greatest_closed
  1865 greatest_Lower_above ~> greatest_Lower_below
  1866 one_zero ~> carrier_one_zero
  1867 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1868 
  1869 
  1870 *** HOL-Nominal ***
  1871 
  1872 * Nominal datatypes can now contain type-variables.
  1873 
  1874 * Commands 'nominal_inductive' and 'equivariance' work with local
  1875 theory targets.
  1876 
  1877 * Nominal primrec can now works with local theory targets and its
  1878 specification syntax now conforms to the general format as seen in
  1879 'inductive' etc.
  1880 
  1881 * Method "perm_simp" honours the standard simplifier attributes
  1882 (no_asm), (no_asm_use) etc.
  1883 
  1884 * The new predicate #* is defined like freshness, except that on the
  1885 left hand side can be a set or list of atoms.
  1886 
  1887 * Experimental command 'nominal_inductive2' derives strong induction
  1888 principles for inductive definitions.  In contrast to
  1889 'nominal_inductive', which can only deal with a fixed number of
  1890 binders, it can deal with arbitrary expressions standing for sets of
  1891 atoms to be avoided.  The only inductive definition we have at the
  1892 moment that needs this generalisation is the typing rule for Lets in
  1893 the algorithm W:
  1894 
  1895  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1896  -----------------------------------------------------------------
  1897          Gamma |- Let x be t1 in t2 : T2
  1898 
  1899 In this rule one wants to avoid all the binders that are introduced by
  1900 "close Gamma T1".  We are looking for other examples where this
  1901 feature might be useful.  Please let us know.
  1902 
  1903 
  1904 *** HOLCF ***
  1905 
  1906 * Reimplemented the simplification procedure for proving continuity
  1907 subgoals.  The new simproc is extensible; users can declare additional
  1908 continuity introduction rules with the attribute [cont2cont].
  1909 
  1910 * The continuity simproc now uses a different introduction rule for
  1911 solving continuity subgoals on terms with lambda abstractions.  In
  1912 some rare cases the new simproc may fail to solve subgoals that the
  1913 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1914 Potential INCOMPATIBILITY.
  1915 
  1916 * Command 'fixrec': specification syntax now conforms to the general
  1917 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1918 examples.  INCOMPATIBILITY.
  1919 
  1920 
  1921 *** ZF ***
  1922 
  1923 * Proof of Zorn's Lemma for partial orders.
  1924 
  1925 
  1926 *** ML ***
  1927 
  1928 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1929 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1930 depends on multithreading, so timouts will not work before Poly/ML
  1931 5.2.1!
  1932 
  1933 * High-level support for concurrent ML programming, see
  1934 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1935 particularly convenient to organize independent functional
  1936 computations.  The concept of "synchronized variables" provides a
  1937 higher-order interface for components with shared state, avoiding the
  1938 delicate details of mutexes and condition variables.  (Requires
  1939 Poly/ML 5.2.1 or later.)
  1940 
  1941 * ML bindings produced via Isar commands are stored within the Isar
  1942 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1943 become thread-safe and work with undo as expected (concerning
  1944 top-level bindings, not side-effects on global references).
  1945 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1946 compiler at runtime; really global bindings need to be given outside a
  1947 theory.  (Requires Poly/ML 5.2 or later.)
  1948 
  1949 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1950 context.  Top-level ML bindings are stored within the proof context in
  1951 a purely sequential fashion, disregarding the nested proof structure.
  1952 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1953 proof.  (Requires Poly/ML 5.2 or later.)
  1954 
  1955 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1956 and Method.setup, as well as Isar commands 'attribute_setup' and
  1957 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1958 existing code accordingly, or use plain 'setup' together with old
  1959 Method.add_method.
  1960 
  1961 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1962 to 'a -> thm, while results are always tagged with an authentic oracle
  1963 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1964 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1965 accordingly.  Note that extra performance may be gained by producing
  1966 the cterm carefully, avoiding slow Thm.cterm_of.
  1967 
  1968 * Simplified interface for defining document antiquotations via
  1969 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1970 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1971 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1972 examples.
  1973 
  1974 * More systematic treatment of long names, abstract name bindings, and
  1975 name space operations.  Basic operations on qualified names have been
  1976 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1977 Long_Name.append.  Old type bstring has been mostly replaced by
  1978 abstract type binding (see structure Binding), which supports precise
  1979 qualification by packages and local theory targets, as well as proper
  1980 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1981 bstring values into Binding.name, or better pass through abstract
  1982 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1983 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1984 
  1985 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1986 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1987 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1988 
  1989 * Disposed old type and term read functions (Sign.read_def_typ,
  1990 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1991 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1992 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1993 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1994 resort for legacy applications.
  1995 
  1996 * Disposed old declarations, tactics, tactic combinators that refer to
  1997 the simpset or claset of an implicit theory (such as Addsimps,
  1998 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1999 embedded ML text, or local_simpset_of with a proper context passed as
  2000 explicit runtime argument.
  2001 
  2002 * Rules and tactics that read instantiations (read_instantiate,
  2003 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2004 context, which is required for parsing and type-checking.  Moreover,
  2005 the variables are specified as plain indexnames, not string encodings
  2006 thereof.  INCOMPATIBILITY.
  2007 
  2008 * Generic Toplevel.add_hook interface allows to analyze the result of
  2009 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2010 for theorem dependency output of transactions resulting in a new
  2011 theory state.
  2012 
  2013 * ML antiquotations: block-structured compilation context indicated by
  2014 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2015 
  2016   @{binding name}                         - basic name binding
  2017   @{let ?pat = term}                      - term abbreviation (HO matching)
  2018   @{note name = fact}                     - fact abbreviation
  2019   @{thm fact}                             - singleton fact (with attributes)
  2020   @{thms fact}                            - general fact (with attributes)
  2021   @{lemma prop by method}                 - singleton goal
  2022   @{lemma prop by meth1 meth2}            - singleton goal
  2023   @{lemma prop1 ... propN by method}      - general goal
  2024   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2025   @{lemma (open) ...}                     - open derivation
  2026 
  2027 
  2028 *** System ***
  2029 
  2030 * The Isabelle "emacs" tool provides a specific interface to invoke
  2031 Proof General / Emacs, with more explicit failure if that is not
  2032 installed (the old isabelle-interface script silently falls back on
  2033 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2034 installation location of the Proof General distribution.
  2035 
  2036 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2037 the Isabelle process into a JVM/Scala application.  See
  2038 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2039 process wrapper has been discontinued.)
  2040 
  2041 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2042 
  2043 * Various status messages (with exact source position information) are
  2044 emitted, if proper markup print mode is enabled.  This allows
  2045 user-interface components to provide detailed feedback on internal
  2046 prover operations.
  2047 
  2048 
  2049 
  2050 New in Isabelle2008 (June 2008)
  2051 -------------------------------
  2052 
  2053 *** General ***
  2054 
  2055 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2056 and updated, with formally checked references as hyperlinks.
  2057 
  2058 * Theory loader: use_thy (and similar operations) no longer set the
  2059 implicit ML context, which was occasionally hard to predict and in
  2060 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2061 provides a proper context already.
  2062 
  2063 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2064 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2065 'use' within a theory file will do the job.
  2066 
  2067 * Name space merge now observes canonical order, i.e. the second space
  2068 is inserted into the first one, while existing entries in the first
  2069 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2070 swap theory imports.
  2071 
  2072 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2073 INCOMPATIBILITY in identifier syntax etc.
  2074 
  2075 * Outer syntax: string tokens no longer admit escaped white space,
  2076 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2077 white space without escapes.
  2078 
  2079 * Outer syntax: string tokens may contain arbitrary character codes
  2080 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2081 "foo_bar".
  2082 
  2083 
  2084 *** Pure ***
  2085 
  2086 * Context-dependent token translations.  Default setup reverts locally
  2087 fixed variables, and adds hilite markup for undeclared frees.
  2088 
  2089 * Unused theorems can be found using the new command 'unused_thms'.
  2090 There are three ways of invoking it:
  2091 
  2092 (1) unused_thms
  2093      Only finds unused theorems in the current theory.
  2094 
  2095 (2) unused_thms thy_1 ... thy_n -
  2096      Finds unused theorems in the current theory and all of its ancestors,
  2097      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2098 
  2099 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2100      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2101      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2102      their ancestors.
  2103 
  2104 In order to increase the readability of the list produced by
  2105 unused_thms, theorems that have been created by a particular instance
  2106 of a theory command such as 'inductive' or 'function' are considered
  2107 to belong to the same "group", meaning that if at least one theorem in
  2108 this group is used, the other theorems in the same group are no longer
  2109 reported as unused.  Moreover, if all theorems in the group are
  2110 unused, only one theorem in the group is displayed.
  2111 
  2112 Note that proof objects have to be switched on in order for
  2113 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2114 usually the case when using Proof General with the default settings).
  2115 
  2116 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2117 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2118 duplicate fact bindings, or even accidental fact duplications.  Note
  2119 that tools may maintain dynamically scoped facts systematically, using
  2120 PureThy.add_thms_dynamic.
  2121 
  2122 * Command 'hide' now allows to hide from "fact" name space as well.
  2123 
  2124 * Eliminated destructive theorem database, simpset, claset, and
  2125 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2126 update of theories within ML code.
  2127 
  2128 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2129 INCOMPATIBILITY, object-logics depending on former Pure require
  2130 additional setup PureThy.old_appl_syntax_setup; object-logics
  2131 depending on former CPure need to refer to Pure.
  2132 
  2133 * Commands 'use' and 'ML' are now purely functional, operating on
  2134 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2135 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2136 INCOMPATIBILITY.
  2137 
  2138 * Command 'setup': discontinued implicit version with ML reference.
  2139 
  2140 * Instantiation target allows for simultaneous specification of class
  2141 instance operations together with an instantiation proof.
  2142 Type-checking phase allows to refer to class operations uniformly.
  2143 See src/HOL/Complex/Complex.thy for an Isar example and
  2144 src/HOL/Library/Eval.thy for an ML example.
  2145 
  2146 * Indexing of literal facts: be more serious about including only
  2147 facts from the visible specification/proof context, but not the
  2148 background context (locale etc.).  Affects `prop` notation and method
  2149 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2150 situations.
  2151 
  2152 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2153 "(open)" option, which used to expose internal bound variables to the
  2154 proof text.
  2155 
  2156 * Isar statements: removed obsolete case "rule_context".
  2157 INCOMPATIBILITY, better use explicit fixes/assumes.
  2158 
  2159 * Locale proofs: default proof step now includes 'unfold_locales';
  2160 hence 'proof' without argument may be used to unfold locale
  2161 predicates.
  2162 
  2163 
  2164 *** Document preparation ***
  2165 
  2166 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2167 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2168 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2169 spot); renamed link color from "darkblue" to "linkcolor" (default
  2170 value unchanged, can be redefined via \definecolor); no longer sets
  2171 "a4paper" option (unnecessary or even intrusive).
  2172 
  2173 * Antiquotation @{lemma A method} proves proposition A by the given
  2174 method (either a method name or a method name plus (optional) method
  2175 arguments in parentheses) and prints A just like @{prop A}.
  2176 
  2177 
  2178 *** HOL ***
  2179 
  2180 * New primrec package.  Specification syntax conforms in style to
  2181 definition/function/....  No separate induction rule is provided.  The
  2182 "primrec" command distinguishes old-style and new-style specifications
  2183 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2184 When adjusting theories, beware: constants stemming from new-style
  2185 primrec specifications have authentic syntax.
  2186 
  2187 * Metis prover is now an order of magnitude faster, and also works
  2188 with multithreading.
  2189 
  2190 * Metis: the maximum number of clauses that can be produced from a
  2191 theorem is now given by the attribute max_clauses.  Theorems that
  2192 exceed this number are ignored, with a warning printed.
  2193 
  2194 * Sledgehammer no longer produces structured proofs by default. To
  2195 enable, declare [[sledgehammer_full = true]].  Attributes
  2196 reconstruction_modulus, reconstruction_sorts renamed
  2197 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2198 
  2199 * Method "induct_scheme" derives user-specified induction rules
  2200 from well-founded induction and completeness of patterns. This factors
  2201 out some operations that are done internally by the function package
  2202 and makes them available separately.  See
  2203 src/HOL/ex/Induction_Scheme.thy for examples.
  2204 
  2205 * More flexible generation of measure functions for termination
  2206 proofs: Measure functions can be declared by proving a rule of the
  2207 form "is_measure f" and giving it the [measure_function] attribute.
  2208 The "is_measure" predicate is logically meaningless (always true), and
  2209 just guides the heuristic.  To find suitable measure functions, the
  2210 termination prover sets up the goal "is_measure ?f" of the appropriate
  2211 type and generates all solutions by prolog-style backwards proof using
  2212 the declared rules.
  2213 
  2214 This setup also deals with rules like 
  2215 
  2216   "is_measure f ==> is_measure (list_size f)"
  2217 
  2218 which accommodates nested datatypes that recurse through lists.
  2219 Similar rules are predeclared for products and option types.
  2220 
  2221 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2222 
  2223   INCOMPATIBILITIES:
  2224 
  2225   - Definitions of overloaded constants on sets have to be replaced by
  2226     definitions on => and bool.
  2227 
  2228   - Some definitions of overloaded operators on sets can now be proved
  2229     using the definitions of the operators on => and bool.  Therefore,
  2230     the following theorems have been renamed:
  2231 
  2232       subset_def   -> subset_eq
  2233       psubset_def  -> psubset_eq
  2234       set_diff_def -> set_diff_eq
  2235       Compl_def    -> Compl_eq
  2236       Sup_set_def  -> Sup_set_eq
  2237       Inf_set_def  -> Inf_set_eq
  2238       sup_set_def  -> sup_set_eq
  2239       inf_set_def  -> inf_set_eq
  2240 
  2241   - Due to the incompleteness of the HO unification algorithm, some
  2242     rules such as subst may require manual instantiation, if some of
  2243     the unknowns in the rule is a set.
  2244 
  2245   - Higher order unification and forward proofs:
  2246     The proof pattern
  2247 
  2248       have "P (S::'a set)" <...>
  2249       then have "EX S. P S" ..
  2250 
  2251     no longer works (due to the incompleteness of the HO unification
  2252     algorithm) and must be replaced by the pattern
  2253 
  2254       have "EX S. P S"
  2255       proof
  2256         show "P S" <...>
  2257       qed
  2258 
  2259   - Calculational reasoning with subst (or similar rules):
  2260     The proof pattern
  2261 
  2262       have "P (S::'a set)" <...>
  2263       also have "S = T" <...>
  2264       finally have "P T" .
  2265 
  2266     no longer works (for similar reasons as the previous example) and
  2267     must be replaced by something like
  2268 
  2269       have "P (S::'a set)" <...>
  2270       moreover have "S = T" <...>
  2271       ultimately have "P T" by simp
  2272 
  2273   - Tactics or packages written in ML code:
  2274     Code performing pattern matching on types via
  2275 
  2276       Type ("set", [T]) => ...
  2277 
  2278     must be rewritten. Moreover, functions like strip_type or
  2279     binder_types no longer return the right value when applied to a
  2280     type of the form
  2281 
  2282       T1 => ... => Tn => U => bool
  2283 
  2284     rather than
  2285 
  2286       T1 => ... => Tn => U set
  2287 
  2288 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2289 Wellfounded_Relations to theory Wellfounded.
  2290 
  2291 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2292 
  2293 * Class finite no longer treats UNIV as class parameter.  Use class
  2294 enum from theory Library/Enum instead to achieve a similar effect.
  2295 INCOMPATIBILITY.
  2296 
  2297 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2298 and "Cons".  INCOMPATIBILITY.
  2299 
  2300 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2301 Potential INCOMPATIBILITY.
  2302 
  2303 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2304 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2305 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2306 
  2307 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2308 the same name in theory Orderings:
  2309 
  2310   less_trans
  2311   less_linear
  2312   le_imp_less_or_eq
  2313   le_less_trans
  2314   less_le_trans
  2315   less_not_sym
  2316   less_asym
  2317 
  2318 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2319 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2320 and different variable names.
  2321 
  2322 * Library/Option_ord.thy: Canonical order on option type.
  2323 
  2324 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2325 finite maps.
  2326 
  2327 * Library/Countable.thy: Type class for countable types.
  2328 
  2329 * Theory Int: The representation of numerals has changed.  The infix
  2330 operator BIT and the bit datatype with constructors B0 and B1 have
  2331 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2332 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2333 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2334 accordingly.
  2335 
  2336 * Theory Nat: definition of <= and < on natural numbers no longer
  2337 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2338 le_def and less_def have disappeared.  Consider lemmas not_less
  2339 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2340 
  2341 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2342 (whose purpose mainly is for various fold_set functionals) have been
  2343 abandoned in favor of the existing algebraic classes
  2344 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2345 lower_semilattice (resp. upper_semilattice) and linorder.
  2346 INCOMPATIBILITY.
  2347 
  2348 * Theory Transitive_Closure: induct and cases rules now declare proper
  2349 case_names ("base" and "step").  INCOMPATIBILITY.
  2350 
  2351 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2352 lattices.  The form set-specific version is available as
  2353 Inductive.lfp_ordinal_induct_set.
  2354 
  2355 * Renamed theorems "power.simps" to "power_int.simps".
  2356 INCOMPATIBILITY.
  2357 
  2358 * Class semiring_div provides basic abstract properties of semirings
  2359 with division and modulo operations.  Subsumes former class dvd_mod.
  2360 
  2361 * Merged theories IntDef, Numeral and IntArith into unified theory
  2362 Int.  INCOMPATIBILITY.
  2363 
  2364 * Theory Library/Code_Index: type "index" now represents natural
  2365 numbers rather than integers.  INCOMPATIBILITY.
  2366 
  2367 * New class "uminus" with operation "uminus" (split of from class
  2368 "minus" which now only has operation "minus", binary).
  2369 INCOMPATIBILITY.
  2370 
  2371 * Constants "card", "internal_split", "option_map" now with authentic
  2372 syntax.  INCOMPATIBILITY.
  2373 
  2374 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2375 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2376 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2377 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2378 Sup_set_def, le_def, less_def, option_map_def now with object
  2379 equality.  INCOMPATIBILITY.
  2380 
  2381 * Records. Removed K_record, and replaced it by pure lambda term
  2382 %x. c. The simplifier setup is now more robust against eta expansion.
  2383 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2384 
  2385 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2386 
  2387 * Library/ListVector: new theory of arithmetic vector operations.
  2388 
  2389 * Library/Order_Relation: new theory of various orderings as sets of
  2390 pairs.  Defines preorders, partial orders, linear orders and
  2391 well-orders on sets and on types.
  2392 
  2393 
  2394 *** ZF ***
  2395 
  2396 * Renamed some theories to allow to loading both ZF and HOL in the
  2397 same session:
  2398 
  2399   Datatype  -> Datatype_ZF
  2400   Inductive -> Inductive_ZF
  2401   Int       -> Int_ZF
  2402   IntDiv    -> IntDiv_ZF
  2403   Nat       -> Nat_ZF
  2404   List      -> List_ZF
  2405   Main      -> Main_ZF
  2406 
  2407 INCOMPATIBILITY: ZF theories that import individual theories below
  2408 Main might need to be adapted.  Regular theory Main is still
  2409 available, as trivial extension of Main_ZF.
  2410 
  2411 
  2412 *** ML ***
  2413 
  2414 * ML within Isar: antiquotation @{const name} or @{const
  2415 name(typargs)} produces statically-checked Const term.
  2416 
  2417 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2418 (of the same name).  Removed obsolete print command.
  2419 
  2420 * Removed obsolete "use_legacy_bindings" function.
  2421 
  2422 * The ``print mode'' is now a thread-local value derived from a global
  2423 template (the former print_mode reference), thus access becomes
  2424 non-critical.  The global print_mode reference is for session
  2425 management only; user-code should use print_mode_value,
  2426 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2427 
  2428 * Functions system/system_out provide a robust way to invoke external
  2429 shell commands, with propagation of interrupts (requires Poly/ML
  2430 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2431 
  2432 
  2433 *** System ***
  2434 
  2435 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2436 in accordance with Proof General 3.7, which prefers GNU emacs.
  2437 
  2438 * isatool tty runs Isabelle process with plain tty interaction;
  2439 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2440 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2441 
  2442 * isatool browser now works with Cygwin as well, using general
  2443 "javapath" function defined in Isabelle process environment.
  2444 
  2445 * YXML notation provides a simple and efficient alternative to
  2446 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2447 isatool yxml as described in the Isabelle system manual.
  2448 
  2449 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2450 provides general wrapper for managing an Isabelle process in a robust
  2451 fashion, with ``cooked'' output from stdin/stderr.
  2452 
  2453 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2454 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2455 
  2456 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2457 way of changing the user's settings is via
  2458 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2459 script.
  2460 
  2461 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2462 cores of the underlying machine, which is a good starting point for
  2463 optimal performance tuning.  The corresponding usedir option -M allows
  2464 "max" as an alias for "0".  WARNING: does not work on certain versions
  2465 of Mac OS (with Poly/ML 5.1).
  2466 
  2467 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2468 adverse effect of Isabelle flooding interactive front-ends (notably
  2469 ProofGeneral / XEmacs).
  2470 
  2471 
  2472 
  2473 New in Isabelle2007 (November 2007)
  2474 -----------------------------------
  2475 
  2476 *** General ***
  2477 
  2478 * More uniform information about legacy features, notably a
  2479 warning/error of "Legacy feature: ...", depending on the state of the
  2480 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2481 legacy features will disappear eventually.
  2482 
  2483 * Theory syntax: the header format ``theory A = B + C:'' has been
  2484 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2485 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2486 
  2487 * Theory syntax: the old non-Isar theory file format has been
  2488 discontinued altogether.  Note that ML proof scripts may still be used
  2489 with Isar theories; migration is usually quite simple with the ML
  2490 function use_legacy_bindings.  INCOMPATIBILITY.
  2491 
  2492 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2493 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2494 quotes.
  2495 
  2496 * Theory loader: be more serious about observing the static theory
  2497 header specifications (including optional directories), but not the
  2498 accidental file locations of previously successful loads.  The strict
  2499 update policy of former update_thy is now already performed by
  2500 use_thy, so the former has been removed; use_thys updates several
  2501 theories simultaneously, just as 'imports' within a theory header
  2502 specification, but without merging the results.  Potential
  2503 INCOMPATIBILITY: may need to refine theory headers and commands
  2504 ROOT.ML which depend on load order.
  2505 
  2506 * Theory loader: optional support for content-based file
  2507 identification, instead of the traditional scheme of full physical
  2508 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2509 (cf. the system manual).  The new scheme allows to work with
  2510 non-finished theories in persistent session images, such that source
  2511 files may be moved later on without requiring reloads.
  2512 
  2513 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2514 file (with the same base name as the theory) are considered a legacy
  2515 feature, which will disappear eventually. Even now, the theory loader
  2516 no longer maintains dependencies on such files.
  2517 
  2518 * Syntax: the scope for resolving ambiguities via type-inference is
  2519 now limited to individual terms, instead of whole simultaneous
  2520 specifications as before. This greatly reduces the complexity of the
  2521 syntax module and improves flexibility by separating parsing and
  2522 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2523 'fixes' etc.) are required in rare situations.
  2524 
  2525 * Syntax: constants introduced by new-style packages ('definition',
  2526 'abbreviation' etc.) are passed through the syntax module in
  2527 ``authentic mode''. This means that associated mixfix annotations
  2528 really stick to such constants, independently of potential name space
  2529 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2530 trees are represented slightly differently, may need to adapt syntax
  2531 translations accordingly. Use CONST marker in 'translations' and
  2532 @{const_syntax} antiquotation in 'parse_translation' etc.
  2533 
  2534 * Legacy goal package: reduced interface to the bare minimum required
  2535 to keep existing proof scripts running.  Most other user-level
  2536 functions are now part of the OldGoals structure, which is *not* open
  2537 by default (consider isatool expandshort before open OldGoals).
  2538 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2539 these tend to cause confusion about the actual goal (!) context being
  2540 used here, which is not necessarily the same as the_context().
  2541 
  2542 * Command 'find_theorems': supports "*" wild-card in "name:"
  2543 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2544 support a specific search form (see ProofGeneral/CHANGES).
  2545 
  2546 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2547 by default, which means that "prems" (and also "fixed variables") are
  2548 suppressed from proof state output.  Note that the ProofGeneral
  2549 settings mechanism allows to change and save options persistently, but
  2550 older versions of Isabelle will fail to start up if a negative prems
  2551 limit is imposed.
  2552 
  2553 * Local theory targets may be specified by non-nested blocks of
  2554 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2555 contain definitions, theorems etc., including any derived mechanism
  2556 that has been implemented on top of these primitives.  This concept
  2557 generalizes the existing ``theorem (in ...)'' towards more versatility
  2558 and scalability.
  2559 
  2560 * Proof General interface: proper undo of final 'end' command;
  2561 discontinued Isabelle/classic mode (ML proof scripts).
  2562 
  2563 
  2564 *** Document preparation ***
  2565 
  2566 * Added antiquotation @{theory name} which prints the given name,
  2567 after checking that it refers to a valid ancestor theory in the
  2568 current context.
  2569 
  2570 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2571 check the given source text as ML type/structure, printing verbatim.
  2572 
  2573 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2574 "c args == rhs" given in the current context.  (Any number of
  2575 arguments may be given on the LHS.)
  2576 
  2577 
  2578 *** Pure ***
  2579 
  2580 * The 'class' package offers a combination of axclass and locale to
  2581 achieve Haskell-like type classes in Isabelle.  Definitions and
  2582 theorems within a class context produce both relative results (with
  2583 implicit parameters according to the locale context), and polymorphic
  2584 constants with qualified polymorphism (according to the class
  2585 context).  Within the body context of a 'class' target, a separate
  2586 syntax layer ("user space type system") takes care of converting
  2587 between global polymorphic consts and internal locale representation.
  2588 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2589 "isatool doc classes" provides a tutorial.
  2590 
  2591 * Generic code generator framework allows to generate executable
  2592 code for ML and Haskell (including Isabelle classes).  A short usage
  2593 sketch:
  2594 
  2595     internal compilation:
  2596         export_code <list of constants (term syntax)> in SML
  2597     writing SML code to a file:
  2598         export_code <list of constants (term syntax)> in SML <filename>
  2599     writing OCaml code to a file:
  2600         export_code <list of constants (term syntax)> in OCaml <filename>
  2601     writing Haskell code to a bunch of files:
  2602         export_code <list of constants (term syntax)> in Haskell <filename>
  2603 
  2604     evaluating closed propositions to True/False using code generation:
  2605         method ``eval''
  2606 
  2607 Reasonable default setup of framework in HOL.
  2608 
  2609 Theorem attributs for selecting and transforming function equations theorems:
  2610 
  2611     [code fun]:        select a theorem as function equation for a specific constant
  2612     [code fun del]:    deselect a theorem as function equation for a specific constant
  2613     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2614     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2615 
  2616 User-defined serializations (target in {SML, OCaml, Haskell}):
  2617 
  2618     code_const <and-list of constants (term syntax)>
  2619       {(target) <and-list of const target syntax>}+
  2620 
  2621     code_type <and-list of type constructors>
  2622       {(target) <and-list of type target syntax>}+
  2623 
  2624     code_instance <and-list of instances>
  2625       {(target)}+
  2626         where instance ::= <type constructor> :: <class>
  2627 
  2628     code_class <and_list of classes>
  2629       {(target) <and-list of class target syntax>}+
  2630         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2631 
  2632 code_instance and code_class only are effective to target Haskell.
  2633 
  2634 For example usage see src/HOL/ex/Codegenerator.thy and
  2635 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2636 generation from Isabelle/HOL theories is available via "isatool doc
  2637 codegen".
  2638 
  2639 * Code generator: consts in 'consts_code' Isar commands are now
  2640 referred to by usual term syntax (including optional type
  2641 annotations).
  2642 
  2643 * Command 'no_translations' removes translation rules from theory
  2644 syntax.
  2645 
  2646 * Overloaded definitions are now actually checked for acyclic
  2647 dependencies.  The overloading scheme is slightly more general than
  2648 that of Haskell98, although Isabelle does not demand an exact
  2649 correspondence to type class and instance declarations.
  2650 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2651 exotic versions of overloading -- at the discretion of the user!
  2652 
  2653 Polymorphic constants are represented via type arguments, i.e. the
  2654 instantiation that matches an instance against the most general
  2655 declaration given in the signature.  For example, with the declaration
  2656 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2657 as c(nat).  Overloading is essentially simultaneous structural
  2658 recursion over such type arguments.  Incomplete specification patterns
  2659 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2660 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2661 Command 'print_theory' outputs the normalized system of recursive
  2662 equations, see section "definitions".
  2663 
  2664 * Configuration options are maintained within the theory or proof
  2665 context (with name and type bool/int/string), providing a very simple
  2666 interface to a poor-man's version of general context data.  Tools may
  2667 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2668 these values using Config.get etc.  Users may change options via an
  2669 associated attribute of the same name.  This form of context
  2670 declaration works particularly well with commands 'declare' or
  2671 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2672 very easy to avoid global references, which would not observe Isar
  2673 toplevel undo/redo and fail to work with multithreading.
  2674 
  2675 Various global ML references of Pure and HOL have been turned into
  2676 configuration options:
  2677 
  2678   Unify.search_bound		unify_search_bound
  2679   Unify.trace_bound		unify_trace_bound
  2680   Unify.trace_simp		unify_trace_simp
  2681   Unify.trace_types		unify_trace_types
  2682   Simplifier.simp_depth_limit	simp_depth_limit
  2683   Blast.depth_limit		blast_depth_limit
  2684   DatatypeProp.dtK		datatype_distinctness_limit
  2685   fast_arith_neq_limit  	fast_arith_neq_limit
  2686   fast_arith_split_limit	fast_arith_split_limit
  2687 
  2688 * Named collections of theorems may be easily installed as context
  2689 data using the functor NamedThmsFun (see also
  2690 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2691 attributes; there is also a toplevel print command.  This facility is
  2692 just a common case of general context data, which is the preferred way
  2693 for anything more complex than just a list of facts in canonical
  2694 order.
  2695 
  2696 * Isar: command 'declaration' augments a local theory by generic
  2697 declaration functions written in ML.  This enables arbitrary content
  2698 being added to the context, depending on a morphism that tells the
  2699 difference of the original declaration context wrt. the application
  2700 context encountered later on.
  2701 
  2702 * Isar: proper interfaces for simplification procedures.  Command
  2703 'simproc_setup' declares named simprocs (with match patterns, and body
  2704 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2705 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2706 
  2707 * Isar: an extra pair of brackets around attribute declarations
  2708 abbreviates a theorem reference involving an internal dummy fact,
  2709 which will be ignored later --- only the effect of the attribute on
  2710 the background context will persist.  This form of in-place
  2711 declarations is particularly useful with commands like 'declare' and
  2712 'using', for example ``have A using [[simproc a]] by simp''.
  2713 
  2714 * Isar: method "assumption" (and implicit closing of subproofs) now
  2715 takes simple non-atomic goal assumptions into account: after applying
  2716 an assumption as a rule the resulting subgoals are solved by atomic
  2717 assumption steps.  This is particularly useful to finish 'obtain'
  2718 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2719 without referring to the original premise "!!x. P x ==> thesis" in the
  2720 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2721 more permissive.
  2722 
  2723 * Isar: implicit use of prems from the Isar proof context is
  2724 considered a legacy feature.  Common applications like ``have A .''
  2725 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2726 referencing facts explicitly here improves readability and
  2727 maintainability of proof texts.
  2728 
  2729 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2730 the obtained context from the course of reasoning!  For example:
  2731 
  2732   assume "EX x y. A x & B y"   -- "any previous fact"
  2733   then guess x and y by clarify
  2734 
  2735 This technique is potentially adventurous, depending on the facts and
  2736 proof tools being involved here.
  2737 
  2738 * Isar: known facts from the proof context may be specified as literal
  2739 propositions, using ASCII back-quote syntax.  This works wherever
  2740 named facts used to be allowed so far, in proof commands, proof
  2741 methods, attributes etc.  Literal facts are retrieved from the context
  2742 according to unification of type and term parameters.  For example,
  2743 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2744 theorems in the current context, then these are valid literal facts:
  2745 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2746 
  2747 There is also a proof method "fact" which does the same composition
  2748 for explicit goal states, e.g. the following proof texts coincide with
  2749 certain special cases of literal facts:
  2750 
  2751   have "A" by fact                 ==  note `A`
  2752   have "A ==> B" by fact           ==  note `A ==> B`
  2753   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2754   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2755 
  2756 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2757 outer syntax.  Thus symbolic identifiers may be used without
  2758 additional white space in declarations like this: ``assume *: A''.
  2759 
  2760 * Isar: 'print_facts' prints all local facts of the current context,
  2761 both named and unnamed ones.
  2762 
  2763 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2764 
  2765   def x == "t" and y == "u"
  2766 
  2767 * Isar: added command 'unfolding', which is structurally similar to
  2768 'using', but affects both the goal state and facts by unfolding given
  2769 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2770 'unfolded' attribute may be replaced by first-class proof text.
  2771 
  2772 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2773 and command 'unfolding' now all support object-level equalities
  2774 (potentially conditional).  The underlying notion of rewrite rule is
  2775 analogous to the 'rule_format' attribute, but *not* that of the
  2776 Simplifier (which is usually more generous).
  2777 
  2778 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2779 premises of a theorem by n. Useful in conjunction with drule.
  2780 
  2781 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2782 method expression within a sandbox consisting of the first N
  2783 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2784 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2785 simplifies all new goals that emerge from applying rule foo to the
  2786 originally first one.
  2787 
  2788 * Isar: schematic goals are no longer restricted to higher-order
  2789 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2790 expected.
  2791 
  2792 * Isar: the conclusion of a long theorem statement is now either
  2793 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2794 (essentially a disjunction of cases with local parameters and
  2795 assumptions).  The latter allows to express general elimination rules
  2796 adequately; in this notation common elimination rules look like this:
  2797 
  2798   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2799     assumes "EX x. P x"
  2800     obtains x where "P x"
  2801 
  2802   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2803     assumes "A & B"
  2804     obtains A and B
  2805 
  2806   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2807     assumes "A | B"
  2808     obtains
  2809       A
  2810     | B
  2811 
  2812 The subsequent classical rules even refer to the formal "thesis"
  2813 explicitly:
  2814 
  2815   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2816     obtains "~ thesis"
  2817 
  2818   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2819     obtains "thesis ==> something"
  2820 
  2821 The actual proof of an 'obtains' statement is analogous to that of the
  2822 Isar proof element 'obtain', only that there may be several cases.
  2823 Optional case names may be specified in parentheses; these will be
  2824 available both in the present proof and as annotations in the
  2825 resulting rule, for later use with the 'cases' method (cf. attribute
  2826 case_names).
  2827 
  2828 * Isar: the assumptions of a long theorem statement are available as
  2829 "assms" fact in the proof context.  This is more appropriate than the
  2830 (historical) "prems", which refers to all assumptions of the current
  2831 context, including those from the target locale, proof body etc.
  2832 
  2833 * Isar: 'print_statement' prints theorems from the current theory or
  2834 proof context in long statement form, according to the syntax of a
  2835 top-level lemma.
  2836 
  2837 * Isar: 'obtain' takes an optional case name for the local context
  2838 introduction rule (default "that").
  2839 
  2840 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2841 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2842 to occur.
  2843 
  2844 * Pure: syntax "CONST name" produces a fully internalized constant
  2845 according to the current context.  This is particularly useful for
  2846 syntax translations that should refer to internal constant
  2847 representations independently of name spaces.
  2848 
  2849 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2850 instead of "FOO ". This allows multiple binder declarations to coexist
  2851 in the same context.  INCOMPATIBILITY.
  2852 
  2853 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2854 primitive that also works in a locale context (both for constants and
  2855 fixed variables). Type declaration and internal syntactic representation
  2856 of given constants retrieved from the context. Likewise, the
  2857 'no_notation' command allows to remove given syntax annotations from the
  2858 current context.
  2859 
  2860 * Isar/locales: new derived specification elements 'axiomatization',
  2861 'definition', 'abbreviation', which support type-inference, admit
  2862 object-level specifications (equality, equivalence).  See also the
  2863 isar-ref manual.  Examples:
  2864 
  2865   axiomatization
  2866     eq  (infix "===" 50) where
  2867     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2868 
  2869   definition "f x y = x + y + 1"
  2870   definition g where "g x = f x x"
  2871 
  2872   abbreviation
  2873     neq  (infix "=!=" 50) where
  2874     "x =!= y == ~ (x === y)"
  2875 
  2876 These specifications may be also used in a locale context.  Then the
  2877 constants being introduced depend on certain fixed parameters, and the
  2878 constant name is qualified by the locale base name.  An internal
  2879 abbreviation takes care for convenient input and output, making the
  2880 parameters implicit and using the original short name.  See also
  2881 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2882 entities from a monomorphic theory.
  2883 
  2884 Presently, abbreviations are only available 'in' a target locale, but
  2885 not inherited by general import expressions.  Also note that
  2886 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2887 'translations' in common applications.  The "no_abbrevs" print mode
  2888 prevents folding of abbreviations in term output.
  2889 
  2890 Concrete syntax is attached to specified constants in internal form,
  2891 independently of name spaces.  The parse tree representation is
  2892 slightly different -- use 'notation' instead of raw 'syntax', and
  2893 'translations' with explicit "CONST" markup to accommodate this.
  2894 
  2895 * Pure/Isar: unified syntax for new-style specification mechanisms
  2896 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2897 full type inference and dummy patterns ("_").  For example:
  2898 
  2899   definition "K x _ = x"
  2900 
  2901   inductive conj for A B
  2902   where "A ==> B ==> conj A B"
  2903 
  2904 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2905 the current context.  Print mode "no_abbrevs" prevents inversion of
  2906 abbreviations on output.
  2907 
  2908 * Isar/locales: improved parameter handling: use of locales "var" and
  2909 "struct" no longer necessary; - parameter renamings are no longer
  2910 required to be injective.  For example, this allows to define
  2911 endomorphisms as locale endom = homom mult mult h.
  2912 
  2913 * Isar/locales: changed the way locales with predicates are defined.
  2914 Instead of accumulating the specification, the imported expression is
  2915 now an interpretation.  INCOMPATIBILITY: different normal form of
  2916 locale expressions.  In particular, in interpretations of locales with
  2917 predicates, goals repesenting already interpreted fragments are not
  2918 removed automatically.  Use methods `intro_locales' and
  2919 `unfold_locales'; see below.
  2920 
  2921 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2922 provide backward reasoning on locales predicates.  The methods are
  2923 aware of interpretations and discharge corresponding goals.
  2924 `intro_locales' is less aggressive then `unfold_locales' and does not
  2925 unfold predicates to assumptions.
  2926 
  2927 * Isar/locales: the order in which locale fragments are accumulated
  2928 has changed.  This enables to override declarations from fragments due
  2929 to interpretations -- for example, unwanted simp rules.
  2930 
  2931 * Isar/locales: interpretation in theories and proof contexts has been
  2932 extended.  One may now specify (and prove) equations, which are
  2933 unfolded in interpreted theorems.  This is useful for replacing
  2934 defined concepts (constants depending on locale parameters) by
  2935 concepts already existing in the target context.  Example:
  2936 
  2937   interpretation partial_order ["op <= :: [int, int] => bool"]
  2938     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2939 
  2940 Typically, the constant `partial_order.less' is created by a
  2941 definition specification element in the context of locale
  2942 partial_order.
  2943 
  2944 * Method "induct": improved internal context management to support
  2945 local fixes and defines on-the-fly. Thus explicit meta-level
  2946 connectives !!  and ==> are rarely required anymore in inductive goals
  2947 (using object-logic connectives for this purpose has been long
  2948 obsolete anyway). Common proof patterns are explained in
  2949 src/HOL/Induct/Common_Patterns.thy, see also
  2950 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2951 examples.
  2952 
  2953 * Method "induct": improved handling of simultaneous goals. Instead of
  2954 introducing object-level conjunction, the statement is now split into
  2955 several conclusions, while the corresponding symbolic cases are nested
  2956 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2957 see src/HOL/Induct/Common_Patterns.thy, for example.
  2958 
  2959 * Method "induct": mutual induction rules are now specified as a list
  2960 of rule sharing the same induction cases. HOL packages usually provide
  2961 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2962 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2963 mutual induction rules differently, i.e. like this:
  2964 
  2965   (induct rule: foo_bar.inducts)
  2966   (induct set: foo bar)
  2967   (induct pred: foo bar)
  2968   (induct type: foo bar)
  2969 
  2970 The ML function ProjectRule.projections turns old-style rules into the
  2971 new format.
  2972 
  2973 * Method "coinduct": dual of induction, see
  2974 src/HOL/Library/Coinductive_List.thy for various examples.
  2975 
  2976 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2977 considered a legacy feature.
  2978 
  2979 * Attribute "symmetric" produces result with standardized schematic
  2980 variables (index 0).  Potential INCOMPATIBILITY.
  2981 
  2982 * Simplifier: by default the simplifier trace only shows top level
  2983 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2984 default. Thus there is less danger of being flooded by the trace. The
  2985 trace indicates where parts have been suppressed.
  2986   
  2987 * Provers/classical: removed obsolete classical version of elim_format
  2988 attribute; classical elim/dest rules are now treated uniformly when
  2989 manipulating the claset.
  2990 
  2991 * Provers/classical: stricter checks to ensure that supplied intro,
  2992 dest and elim rules are well-formed; dest and elim rules must have at
  2993 least one premise.
  2994 
  2995 * Provers/classical: attributes dest/elim/intro take an optional
  2996 weight argument for the rule (just as the Pure versions).  Weights are
  2997 ignored by automated tools, but determine the search order of single
  2998 rule steps.
  2999 
  3000 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3001 where the body does not mention the bound variable.  Note that dummy
  3002 patterns implicitly depend on their context of bounds, which makes
  3003 "{_. _}" match any set comprehension as expected.  Potential
  3004 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3005 constant "_idtdummy" in the binding position.
  3006 
  3007 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3008 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3009 for example "A -> B" => "Pi A (%_. B)".
  3010 
  3011 * Pure: 'class_deps' command visualizes the subclass relation, using
  3012 the graph browser tool.
  3013 
  3014 * Pure: 'print_theory' now suppresses certain internal declarations by
  3015 default; use '!' option for full details.
  3016 
  3017 
  3018 *** HOL ***
  3019 
  3020 * Method "metis" proves goals by applying the Metis general-purpose
  3021 resolution prover (see also http://gilith.com/software/metis/).
  3022 Examples are in the directory MetisExamples.  WARNING: the
  3023 Isabelle/HOL-Metis integration does not yet work properly with
  3024 multi-threading.
  3025   
  3026 * Command 'sledgehammer' invokes external automatic theorem provers as
  3027 background processes.  It generates calls to the "metis" method if
  3028 successful. These can be pasted into the proof.  Users do not have to
  3029 wait for the automatic provers to return.  WARNING: does not really
  3030 work with multi-threading.
  3031 
  3032 * New "auto_quickcheck" feature tests outermost goal statements for
  3033 potential counter-examples.  Controlled by ML references
  3034 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3035 5000 milliseconds).  Fails silently if statements is outside of
  3036 executable fragment, or any other codgenerator problem occurs.
  3037 
  3038 * New constant "undefined" with axiom "undefined x = undefined".
  3039 
  3040 * Added class "HOL.eq", allowing for code generation with polymorphic
  3041 equality.
  3042 
  3043 * Some renaming of class constants due to canonical name prefixing in
  3044 the new 'class' package:
  3045 
  3046     HOL.abs ~> HOL.abs_class.abs
  3047     HOL.divide ~> HOL.divide_class.divide
  3048     0 ~> HOL.zero_class.zero
  3049     1 ~> HOL.one_class.one
  3050     op + ~> HOL.plus_class.plus
  3051     op - ~> HOL.minus_class.minus
  3052     uminus ~> HOL.minus_class.uminus
  3053     op * ~> HOL.times_class.times
  3054     op < ~> HOL.ord_class.less
  3055     op <= > HOL.ord_class.less_eq
  3056     Nat.power ~> Power.power_class.power
  3057     Nat.size ~> Nat.size_class.size
  3058     Numeral.number_of ~> Numeral.number_class.number_of
  3059     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3060     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3061     Orderings.min ~> Orderings.ord_class.min
  3062     Orderings.max ~> Orderings.ord_class.max
  3063     Divides.op div ~> Divides.div_class.div
  3064     Divides.op mod ~> Divides.div_class.mod
  3065     Divides.op dvd ~> Divides.div_class.dvd
  3066 
  3067 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3068 
  3069 a) User-defined constants using any of the names "plus", "minus",
  3070 "times", "less" or "less_eq". The standard syntax translations for
  3071 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3072 names.
  3073 
  3074 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3075 INCOMPATIBILITY: use more specific names.
  3076 
  3077 c) Permutative equations (e.g. "a + b = b + a")
  3078 Since the change of names also changes the order of terms, permutative
  3079 rewrite rules may get applied in a different order. Experience shows
  3080 that this is rarely the case (only two adaptions in the whole Isabelle
  3081 distribution).  INCOMPATIBILITY: rewrite proofs
  3082 
  3083 d) ML code directly refering to constant names
  3084 This in general only affects hand-written proof tactics, simprocs and
  3085 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3086 Consider using @{const_name} antiquotation.
  3087 
  3088 * New class "default" with associated constant "default".
  3089 
  3090 * Function "sgn" is now overloaded and available on int, real, complex
  3091 (and other numeric types), using class "sgn".  Two possible defs of
  3092 sgn are given as equational assumptions in the classes sgn_if and
  3093 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3094 INCOMPATIBILITY.
  3095 
  3096 * Locale "partial_order" now unified with class "order" (cf. theory
  3097 Orderings), added parameter "less".  INCOMPATIBILITY.
  3098 
  3099 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3100 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3101 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3102 
  3103 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3104 changed order of proof goals in instance proofs.
  3105 
  3106 * The transitivity reasoner for partial and linear orders is set up
  3107 for classes "order" and "linorder".  Instances of the reasoner are available
  3108 in all contexts importing or interpreting the corresponding locales.
  3109 Method "order" invokes the reasoner separately; the reasoner
  3110 is also integrated with the Simplifier as a solver.  Diagnostic
  3111 command 'print_orders' shows the available instances of the reasoner
  3112 in the current context.
  3113 
  3114 * Localized monotonicity predicate in theory "Orderings"; integrated
  3115 lemmas max_of_mono and min_of_mono with this predicate.
  3116 INCOMPATIBILITY.
  3117 
  3118 * Formulation of theorem "dense" changed slightly due to integration
  3119 with new class dense_linear_order.
  3120 
  3121 * Uniform lattice theory development in HOL.
  3122 
  3123     constants "meet" and "join" now named "inf" and "sup"
  3124     constant "Meet" now named "Inf"
  3125 
  3126     classes "meet_semilorder" and "join_semilorder" now named
  3127       "lower_semilattice" and "upper_semilattice"
  3128     class "lorder" now named "lattice"
  3129     class "comp_lat" now named "complete_lattice"
  3130 
  3131     Instantiation of lattice classes allows explicit definitions
  3132     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3133 
  3134   INCOMPATIBILITY.  Theorem renames:
  3135 
  3136     meet_left_le            ~> inf_le1
  3137     meet_right_le           ~> inf_le2
  3138     join_left_le            ~> sup_ge1
  3139     join_right_le           ~> sup_ge2
  3140     meet_join_le            ~> inf_sup_ord
  3141     le_meetI                ~> le_infI
  3142     join_leI                ~> le_supI
  3143     le_meet                 ~> le_inf_iff
  3144     le_join                 ~> ge_sup_conv
  3145     meet_idempotent         ~> inf_idem
  3146     join_idempotent         ~> sup_idem
  3147     meet_comm               ~> inf_commute
  3148     join_comm               ~> sup_commute
  3149     meet_leI1               ~> le_infI1
  3150     meet_leI2               ~> le_infI2
  3151     le_joinI1               ~> le_supI1
  3152     le_joinI2               ~> le_supI2
  3153     meet_assoc              ~> inf_assoc
  3154     join_assoc              ~> sup_assoc
  3155     meet_left_comm          ~> inf_left_commute
  3156     meet_left_idempotent    ~> inf_left_idem
  3157     join_left_comm          ~> sup_left_commute
  3158     join_left_idempotent    ~> sup_left_idem
  3159     meet_aci                ~> inf_aci
  3160     join_aci                ~> sup_aci
  3161     le_def_meet             ~> le_iff_inf
  3162     le_def_join             ~> le_iff_sup
  3163     join_absorp2            ~> sup_absorb2
  3164     join_absorp1            ~> sup_absorb1
  3165     meet_absorp1            ~> inf_absorb1
  3166     meet_absorp2            ~> inf_absorb2
  3167     meet_join_absorp        ~> inf_sup_absorb
  3168     join_meet_absorp        ~> sup_inf_absorb
  3169     distrib_join_le         ~> distrib_sup_le
  3170     distrib_meet_le         ~> distrib_inf_le
  3171 
  3172     add_meet_distrib_left   ~> add_inf_distrib_left
  3173     add_join_distrib_left   ~> add_sup_distrib_left
  3174     is_join_neg_meet        ~> is_join_neg_inf
  3175     is_meet_neg_join        ~> is_meet_neg_sup
  3176     add_meet_distrib_right  ~> add_inf_distrib_right
  3177     add_join_distrib_right  ~> add_sup_distrib_right
  3178     add_meet_join_distribs  ~> add_sup_inf_distribs
  3179     join_eq_neg_meet        ~> sup_eq_neg_inf
  3180     meet_eq_neg_join        ~> inf_eq_neg_sup
  3181     add_eq_meet_join        ~> add_eq_inf_sup
  3182     meet_0_imp_0            ~> inf_0_imp_0
  3183     join_0_imp_0            ~> sup_0_imp_0
  3184     meet_0_eq_0             ~> inf_0_eq_0
  3185     join_0_eq_0             ~> sup_0_eq_0
  3186     neg_meet_eq_join        ~> neg_inf_eq_sup
  3187     neg_join_eq_meet        ~> neg_sup_eq_inf
  3188     join_eq_if              ~> sup_eq_if
  3189 
  3190     mono_meet               ~> mono_inf
  3191     mono_join               ~> mono_sup
  3192     meet_bool_eq            ~> inf_bool_eq
  3193     join_bool_eq            ~> sup_bool_eq
  3194     meet_fun_eq             ~> inf_fun_eq
  3195     join_fun_eq             ~> sup_fun_eq
  3196     meet_set_eq             ~> inf_set_eq
  3197     join_set_eq             ~> sup_set_eq
  3198     meet1_iff               ~> inf1_iff
  3199     meet2_iff               ~> inf2_iff
  3200     meet1I                  ~> inf1I
  3201     meet2I                  ~> inf2I
  3202     meet1D1                 ~> inf1D1
  3203     meet2D1                 ~> inf2D1
  3204     meet1D2                 ~> inf1D2
  3205     meet2D2                 ~> inf2D2
  3206     meet1E                  ~> inf1E
  3207     meet2E                  ~> inf2E
  3208     join1_iff               ~> sup1_iff
  3209     join2_iff               ~> sup2_iff
  3210     join1I1                 ~> sup1I1
  3211     join2I1                 ~> sup2I1
  3212     join1I1                 ~> sup1I1
  3213     join2I2                 ~> sup1I2
  3214     join1CI                 ~> sup1CI
  3215     join2CI                 ~> sup2CI
  3216     join1E                  ~> sup1E
  3217     join2E                  ~> sup2E
  3218 
  3219     is_meet_Meet            ~> is_meet_Inf
  3220     Meet_bool_def           ~> Inf_bool_def
  3221     Meet_fun_def            ~> Inf_fun_def
  3222     Meet_greatest           ~> Inf_greatest
  3223     Meet_lower              ~> Inf_lower
  3224     Meet_set_def            ~> Inf_set_def
  3225 
  3226     Sup_def                 ~> Sup_Inf
  3227     Sup_bool_eq             ~> Sup_bool_def
  3228     Sup_fun_eq              ~> Sup_fun_def
  3229     Sup_set_eq              ~> Sup_set_def
  3230 
  3231     listsp_meetI            ~> listsp_infI
  3232     listsp_meet_eq          ~> listsp_inf_eq
  3233 
  3234     meet_min                ~> inf_min
  3235     join_max                ~> sup_max
  3236 
  3237 * Added syntactic class "size"; overloaded constant "size" now has
  3238 type "'a::size ==> bool"
  3239 
  3240 * Internal reorganisation of `size' of datatypes: size theorems
  3241 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3242 simplification rules by default!); theorems "prod.size" now named
  3243 "*.size".
  3244 
  3245 * Class "div" now inherits from class "times" rather than "type".
  3246 INCOMPATIBILITY.
  3247 
  3248 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3249 Linorder etc.  have disappeared; operations defined in terms of
  3250 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3251 
  3252 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3253 
  3254 * HOL-Word: New extensive library and type for generic, fixed size
  3255 machine words, with arithemtic, bit-wise, shifting and rotating
  3256 operations, reflection into int, nat, and bool lists, automation for
  3257 linear arithmetic (by automatic reflection into nat or int), including
  3258 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3259 arithmetic type classes, supporting automatic simplification of
  3260 numerals on all operations.
  3261 
  3262 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3263 
  3264 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3265 
  3266 * Code generator library theories:
  3267   - Code_Integer represents HOL integers by big integer literals in target
  3268     languages.
  3269   - Code_Char represents HOL characters by character literals in target
  3270     languages.
  3271   - Code_Char_chr like Code_Char, but also offers treatment of character
  3272     codes; includes Code_Integer.
  3273   - Executable_Set allows to generate code for finite sets using lists.
  3274   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3275     denominator).
  3276   - Executable_Real implements a subset of real numbers, namly those
  3277     representable by rational numbers.
  3278   - Efficient_Nat implements natural numbers by integers, which in general will
  3279     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3280     includes Code_Integer.
  3281   - Code_Index provides an additional datatype index which is mapped to
  3282     target-language built-in integers.
  3283   - Code_Message provides an additional datatype message_string which is isomorphic to
  3284     strings; messages are mapped to target-language strings.
  3285 
  3286 * New package for inductive predicates
  3287 
  3288   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3289 
  3290     inductive
  3291       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3292       for z_1 :: U_1 and ... and z_n :: U_m
  3293     where
  3294       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3295     | ...
  3296 
  3297   with full support for type-inference, rather than
  3298 
  3299     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3300 
  3301     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3302     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3303 
  3304     inductive "s z_1 ... z_m"
  3305     intros
  3306       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3307       ...
  3308 
  3309   For backward compatibility, there is a wrapper allowing inductive
  3310   sets to be defined with the new package via
  3311 
  3312     inductive_set
  3313       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3314       for z_1 :: U_1 and ... and z_n :: U_m
  3315     where
  3316       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3317     | ...
  3318 
  3319   or
  3320 
  3321     inductive_set
  3322       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3323       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3324       for z_1 :: U_1 and ... and z_n :: U_m
  3325     where
  3326       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3327     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3328     | ...
  3329 
  3330   if the additional syntax "p ..." is required.
  3331 
  3332   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3333   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3334 
  3335   INCOMPATIBILITIES:
  3336 
  3337   - Since declaration and definition of inductive sets or predicates
  3338     is no longer separated, abbreviations involving the newly
  3339     introduced sets or predicates must be specified together with the
  3340     introduction rules after the 'where' keyword (see above), rather
  3341     than before the actual inductive definition.
  3342 
  3343   - The variables in induction and elimination rules are now
  3344     quantified in the order of their occurrence in the introduction
  3345     rules, rather than in alphabetical order. Since this may break
  3346     some proofs, these proofs either have to be repaired, e.g. by
  3347     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3348     statements of the form
  3349 
  3350       case (rule_i a_i_1 ... a_i_{k_i})
  3351 
  3352     or the old order of quantification has to be restored by explicitly adding
  3353     meta-level quantifiers in the introduction rules, i.e.
  3354 
  3355       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3356 
  3357   - The format of the elimination rules is now
  3358 
  3359       p z_1 ... z_m x_1 ... x_n ==>
  3360         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3361         ==> ... ==> P
  3362 
  3363     for predicates and
  3364 
  3365       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3366         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3367         ==> ... ==> P
  3368 
  3369     for sets rather than
  3370 
  3371       x : s z_1 ... z_m ==>
  3372         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3373         ==> ... ==> P
  3374 
  3375     This may require terms in goals to be expanded to n-tuples
  3376     (e.g. using case_tac or simplification with the split_paired_all
  3377     rule) before the above elimination rule is applicable.
  3378 
  3379   - The elimination or case analysis rules for (mutually) inductive
  3380     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3381     list of rules "p_1_..._p_k.elims" is no longer available.
  3382 
  3383 * New package "function"/"fun" for general recursive functions,
  3384 supporting mutual and nested recursion, definitions in local contexts,
  3385 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3386 for small examples, and the separate tutorial on the function
  3387 package. The old recdef "package" is still available as before, but
  3388 users are encouraged to use the new package.
  3389 
  3390 * Method "lexicographic_order" automatically synthesizes termination
  3391 relations as lexicographic combinations of size measures. 
  3392 
  3393 * Case-expressions allow arbitrary constructor-patterns (including
  3394 "_") and take their order into account, like in functional
  3395 programming.  Internally, this is translated into nested
  3396 case-expressions; missing cases are added and mapped to the predefined
  3397 constant "undefined". In complicated cases printing may no longer show
  3398 the original input but the internal form. Lambda-abstractions allow
  3399 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3400 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3401 variable.
  3402 
  3403 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3404 is an abbreviation for "of_nat :: nat => int". The simplification
  3405 rules for "of_nat" have been changed to work like "int" did
  3406 previously.  Potential INCOMPATIBILITY:
  3407   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3408   - of_nat_diff and of_nat_mult are no longer default simp rules
  3409 
  3410 * Method "algebra" solves polynomial equations over (semi)rings using
  3411 Groebner bases. The (semi)ring structure is defined by locales and the
  3412 tool setup depends on that generic context. Installing the method for
  3413 a specific type involves instantiating the locale and possibly adding
  3414 declarations for computation on the coefficients.  The method is
  3415 already instantiated for natural numbers and for the axiomatic class
  3416 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3417 CALCULEMUS 2007 for the general principles underlying this
  3418 architecture of context-aware proof-tools.
  3419 
  3420 * Method "ferrack" implements quantifier elimination over
  3421 special-purpose dense linear orders using locales (analogous to
  3422 "algebra"). The method is already installed for class
  3423 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3424 rat, etc.
  3425 
  3426 * Former constant "List.op @" now named "List.append".  Use ML
  3427 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3428 circumvent possible incompatibilities when working on ML level.
  3429 
  3430 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3431 
  3432 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3433 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3434 
  3435 * New syntax for Haskell-like list comprehension (input only), eg.
  3436 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3437 
  3438 * The special syntax for function "filter" has changed from [x :
  3439 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3440 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3441 
  3442 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3443 defined on nat only, as an abbreviation for [a..<Suc b]
  3444 INCOMPATIBILITY.
  3445 
  3446 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3447 
  3448 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3449 
  3450 * New lemma collection field_simps (an extension of ring_simps) for
  3451 manipulating (in)equations involving division. Multiplies with all
  3452 denominators that can be proved to be non-zero (in equations) or
  3453 positive/negative (in inequations).
  3454 
  3455 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3456 have been improved and renamed to ring_simps, group_simps and
  3457 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3458 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3459 
  3460 * Theory Library/Commutative_Ring: switched from recdef to function
  3461 package; constants add, mul, pow now curried.  Infix syntax for
  3462 algebraic operations.
  3463 
  3464 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3465 INCOMPATIBILITY.
  3466 
  3467 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3468 INCOMPATIBILITY.
  3469 
  3470 * HOL/records: generalised field-update to take a function on the
  3471 field rather than the new value: r(|A := x|) is translated to A_update
  3472 (K x) r The K-combinator that is internally used is called K_record.
  3473 INCOMPATIBILITY: Usage of the plain update functions has to be
  3474 adapted.
  3475  
  3476 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3477 * x = 0, which are required for a semiring.  Richer structures do not
  3478 inherit from semiring_0 anymore, because this property is a theorem
  3479 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3480 there is more to prove, but this is mostly trivial.
  3481 
  3482 * Class "recpower" is generalized to arbitrary monoids, not just
  3483 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3484 commutativity or semiring properties additionally.
  3485 
  3486 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3487 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3488 better use 'abbreviation'.
  3489 
  3490 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3491 
  3492 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3493 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3494 significant changes for setting up numeral syntax for types:
  3495   - New constants Numeral.pred and Numeral.succ instead
  3496       of former Numeral.bin_pred and Numeral.bin_succ.
  3497   - Use integer operations instead of bin_add, bin_mult and so on.
  3498   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3499   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3500 
  3501 See src/HOL/Integ/IntArith.thy for an example setup.
  3502 
  3503 * Command 'normal_form' computes the normal form of a term that may
  3504 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3505 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3506 heavy-duty computations because the functions are compiled to ML
  3507 first.  Correspondingly, a method "normalization" is provided.  See
  3508 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3509 
  3510 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3511 25 like -->); output depends on the "iff" print_mode, the default is
  3512 "A = B" (with priority 50).
  3513 
  3514 * Relations less (<) and less_eq (<=) are also available on type bool.
  3515 Modified syntax to disallow nesting without explicit parentheses,
  3516 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3517 INCOMPATIBILITY.
  3518 
  3519 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3520 
  3521 * Relation composition operator "op O" now has precedence 75 and binds
  3522 stronger than union and intersection. INCOMPATIBILITY.
  3523 
  3524 * The old set interval syntax "{m..n(}" (and relatives) has been
  3525 removed.  Use "{m..<n}" (and relatives) instead.
  3526 
  3527 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3528 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3529 ``declare [[simproc del: neq]]''.
  3530 
  3531 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3532 True/False.
  3533 
  3534 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3535 
  3536 * Theorem setsum_mult renamed to setsum_right_distrib.
  3537 
  3538 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3539 ``rule'' method.
  3540 
  3541 * Reimplemented methods "sat" and "satx", with several improvements:
  3542 goals no longer need to be stated as "<prems> ==> False", equivalences
  3543 (i.e. "=" on type bool) are handled, variable names of the form
  3544 "lit_<n>" are no longer reserved, significant speedup.
  3545 
  3546 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3547 zChaff is still supported as well.
  3548 
  3549 * 'inductive' and 'datatype': provide projections of mutual rules,
  3550 bundled as foo_bar.inducts;
  3551 
  3552 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3553 Library.
  3554 
  3555 * Library: moved theory Accessible_Part to main HOL.
  3556 
  3557 * Library: added theory Coinductive_List of potentially infinite lists
  3558 as greatest fixed-point.
  3559 
  3560 * Library: added theory AssocList which implements (finite) maps as
  3561 association lists.
  3562 
  3563 * Method "evaluation" solves goals (i.e. a boolean expression)
  3564 efficiently by compiling it to ML.  The goal is "proved" (via an
  3565 oracle) if it evaluates to True.
  3566 
  3567 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3568 also when invoked by the simplifier.  This results in the Simplifier
  3569 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3570 Configuration option fast_arith_split_limit=0 recovers the old
  3571 behavior.
  3572 
  3573 * Support for hex (0x20) and binary (0b1001) numerals.
  3574 
  3575 * New method: reify eqs (t), where eqs are equations for an
  3576 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3577 parameter, computes a term s::'b and a list xs::'a list and proves the
  3578 theorem I xs s = t. This is also known as reification or quoting. The
  3579 resulting theorem is applied to the subgoal to substitute t with I xs
  3580 s.  If t is omitted, the subgoal itself is reified.
  3581 
  3582 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3583 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3584 where f is supposed to be a computable function (in the sense of code
  3585 generattion). The method uses reify to compute s and xs as above then
  3586 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3587 r and finally gets the theorem t = r, which is again applied to the
  3588 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3589 
  3590 * Reflection: Automatic reification now handels binding, an example is
  3591 available in src/HOL/ex/ReflectionEx.thy
  3592 
  3593 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3594 command 'statespace' that is similar to 'record', but introduces an
  3595 abstract specification based on the locale infrastructure instead of
  3596 HOL types.  This leads to extra flexibility in composing state spaces,
  3597 in particular multiple inheritance and renaming of components.
  3598 
  3599 
  3600 *** HOL-Complex ***
  3601 
  3602 * Hyperreal: Functions root and sqrt are now defined on negative real
  3603 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3604 Nonnegativity side conditions have been removed from many lemmas, so
  3605 that more subgoals may now be solved by simplification; potential
  3606 INCOMPATIBILITY.
  3607 
  3608 * Real: new type classes formalize real normed vector spaces and
  3609 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3610 and norm :: 'a => real.
  3611 
  3612 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3613 reals into other types. The overloaded constant Reals :: 'a set is now
  3614 defined as range of_real; potential INCOMPATIBILITY.
  3615 
  3616 * Real: proper support for ML code generation, including 'quickcheck'.
  3617 Reals are implemented as arbitrary precision rationals.
  3618 
  3619 * Hyperreal: Several constants that previously worked only for the
  3620 reals have been generalized, so they now work over arbitrary vector
  3621 spaces. Type annotations may need to be added in some cases; potential
  3622 INCOMPATIBILITY.
  3623 
  3624   Infinitesimal  :: ('a::real_normed_vector) star set
  3625   HFinite        :: ('a::real_normed_vector) star set
  3626   HInfinite      :: ('a::real_normed_vector) star set
  3627   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3628   monad          :: ('a::real_normed_vector) star => 'a star set
  3629   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3630   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3631   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3632   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3633   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3634   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3635   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3636   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3637   sgn            :: 'a::real_normed_vector => 'a
  3638   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3639 
  3640 * Complex: Some complex-specific constants are now abbreviations for
  3641 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3642 hnorm.  Other constants have been entirely removed in favor of the
  3643 polymorphic versions (INCOMPATIBILITY):
  3644 
  3645   approx        <-- capprox
  3646   HFinite       <-- CFinite
  3647   HInfinite     <-- CInfinite
  3648   Infinitesimal <-- CInfinitesimal
  3649   monad         <-- cmonad
  3650   galaxy        <-- cgalaxy
  3651   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3652   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3653   (ns)deriv     <-- (ns)cderiv
  3654 
  3655 
  3656 *** HOL-Algebra ***
  3657 
  3658 * Formalisation of ideals and the quotient construction over rings.
  3659 
  3660 * Order and lattice theory no longer based on records.
  3661 INCOMPATIBILITY.
  3662 
  3663 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3664 greatest_closed.  INCOMPATIBILITY.
  3665 
  3666 * Method algebra is now set up via an attribute.  For examples see
  3667 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3668 of algebraic structures.
  3669 
  3670 * Renamed theory CRing to Ring.
  3671 
  3672 
  3673 *** HOL-Nominal ***
  3674 
  3675 * Substantial, yet incomplete support for nominal datatypes (binding
  3676 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3677 src/HOL/Nominal/Examples.  Prospective users should consult
  3678 http://isabelle.in.tum.de/nominal/
  3679 
  3680 
  3681 *** ML ***
  3682 
  3683 * ML basics: just one true type int, which coincides with IntInf.int
  3684 (even on SML/NJ).
  3685 
  3686 * ML within Isar: antiquotations allow to embed statically-checked
  3687 formal entities in the source, referring to the context available at
  3688 compile-time.  For example:
  3689 
  3690 ML {* @{sort "{zero,one}"} *}
  3691 ML {* @{typ "'a => 'b"} *}
  3692 ML {* @{term "%x. x"} *}
  3693 ML {* @{prop "x == y"} *}
  3694 ML {* @{ctyp "'a => 'b"} *}
  3695 ML {* @{cterm "%x. x"} *}
  3696 ML {* @{cprop "x == y"} *}
  3697 ML {* @{thm asm_rl} *}
  3698 ML {* @{thms asm_rl} *}
  3699 ML {* @{type_name c} *}
  3700 ML {* @{type_syntax c} *}
  3701 ML {* @{const_name c} *}
  3702 ML {* @{const_syntax c} *}
  3703 ML {* @{context} *}
  3704 ML {* @{theory} *}
  3705 ML {* @{theory Pure} *}
  3706 ML {* @{theory_ref} *}
  3707 ML {* @{theory_ref Pure} *}
  3708 ML {* @{simpset} *}
  3709 ML {* @{claset} *}
  3710 ML {* @{clasimpset} *}
  3711 
  3712 The same works for sources being ``used'' within an Isar context.
  3713 
  3714 * ML in Isar: improved error reporting; extra verbosity with
  3715 ML_Context.trace enabled.
  3716 
  3717 * Pure/General/table.ML: the join operations now works via exceptions
  3718 DUP/SAME instead of type option. This is simpler in simple cases, and
  3719 admits slightly more efficient complex applications.
  3720 
  3721 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3722 use Context.generic instead of just theory.
  3723 
  3724 * Pure: datatype Context.generic joins theory/Proof.context and
  3725 provides some facilities for code that works in either kind of
  3726 context, notably GenericDataFun for uniform theory and proof data.
  3727 
  3728 * Pure: simplified internal attribute type, which is now always
  3729 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3730 local (Proof.context) attributes have been discontinued, while
  3731 minimizing code duplication. Thm.rule_attribute and
  3732 Thm.declaration_attribute build canonical attributes; see also structure
  3733 Context for further operations on Context.generic, notably
  3734 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3735 declarations and definitions.
  3736 
  3737 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3738 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3739 init only required for impure data. INCOMPATIBILITY: empty really need
  3740 to be empty (no dependencies on theory content!)
  3741 
  3742 * Pure/kernel: consts certification ignores sort constraints given in
  3743 signature declarations. (This information is not relevant to the
  3744 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3745 potential INCOMPATIBILITY.
  3746 
  3747 * Pure: axiomatic type classes are now purely definitional, with
  3748 explicit proofs of class axioms and super class relations performed
  3749 internally. See Pure/axclass.ML for the main internal interfaces --
  3750 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3751 AxClass.axiomatize_class/classrel/arity supersede
  3752 Sign.add_classes/classrel/arities.
  3753 
  3754 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3755 global/local versions on theory vs. Proof.context have been
  3756 discontinued; Attrib.syntax and Method.syntax have been adapted
  3757 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3758 attributes, methods, etc.
  3759 
  3760 * Pure: several functions of signature "... -> theory -> theory * ..."
  3761 have been reoriented to "... -> theory -> ... * theory" in order to
  3762 allow natural usage in combination with the ||>, ||>>, |-> and
  3763 fold_map combinators.
  3764 
  3765 * Pure: official theorem names (closed derivations) and additional
  3766 comments (tags) are now strictly separate.  Name hints -- which are
  3767 maintained as tags -- may be attached any time without affecting the
  3768 derivation.
  3769 
  3770 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3771 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3772 achieve the old behaviour.
  3773 
  3774 * Pure: the "Goal" constant is now called "prop", supporting a
  3775 slightly more general idea of ``protecting'' meta-level rule
  3776 statements.
  3777 
  3778 * Pure: Logic.(un)varify only works in a global context, which is now
  3779 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3780 Logic.legacy_(un)varify as temporary workaround.
  3781 
  3782 * Pure: structure Name provides scalable operations for generating
  3783 internal variable names, notably Name.variants etc.  This replaces
  3784 some popular functions from term.ML:
  3785 
  3786   Term.variant		->  Name.variant
  3787   Term.variantlist	->  Name.variant_list
  3788   Term.invent_names	->  Name.invent_list
  3789 
  3790 Note that low-level renaming rarely occurs in new code -- operations
  3791 from structure Variable are used instead (see below).
  3792 
  3793 * Pure: structure Variable provides fundamental operations for proper
  3794 treatment of fixed/schematic variables in a context.  For example,
  3795 Variable.import introduces fixes for schematics of given facts and
  3796 Variable.export reverses the effect (up to renaming) -- this replaces
  3797 various freeze_thaw operations.
  3798 
  3799 * Pure: structure Goal provides simple interfaces for
  3800 init/conclude/finish and tactical prove operations (replacing former
  3801 Tactic.prove).  Goal.prove is the canonical way to prove results
  3802 within a given context; Goal.prove_global is a degraded version for
  3803 theory level goals, including a global Drule.standard.  Note that
  3804 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3805 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3806 in a locale context).
  3807 
  3808 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3809 and type checking (Syntax.check_term etc.), with common combinations
  3810 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3811 which are considered legacy and await removal.
  3812 
  3813 * Pure/Syntax: generic interfaces for type unchecking
  3814 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3815 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3816 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3817 available for convenience, but refer to the very same operations using
  3818 a mere theory instead of a full context.
  3819 
  3820 * Isar: simplified treatment of user-level errors, using exception
  3821 ERROR of string uniformly.  Function error now merely raises ERROR,
  3822 without any side effect on output channels.  The Isar toplevel takes
  3823 care of proper display of ERROR exceptions.  ML code may use plain
  3824 handle/can/try; cat_error may be used to concatenate errors like this:
  3825 
  3826   ... handle ERROR msg => cat_error msg "..."
  3827 
  3828 Toplevel ML code (run directly or through the Isar toplevel) may be
  3829 embedded into the Isar toplevel with exception display/debug like
  3830 this:
  3831 
  3832   Isar.toplevel (fn () => ...)
  3833 
  3834 INCOMPATIBILITY, removed special transform_error facilities, removed
  3835 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3836 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3837 -- use plain ERROR instead.
  3838 
  3839 * Isar: theory setup now has type (theory -> theory), instead of a
  3840 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3841 
  3842 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3843 ProofContext.debug/verbose flags.
  3844 
  3845 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3846 theory before entering a proof state.  Transactions now always see a
  3847 quasi-functional intermediate checkpoint, both in interactive and
  3848 batch mode.
  3849 
  3850 * Isar: simplified interfaces for outer syntax.  Renamed
  3851 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3852 OuterSyntax.add_parsers -- this functionality is now included in
  3853 OuterSyntax.command etc.  INCOMPATIBILITY.
  3854 
  3855 * Simplifier: the simpset of a running simplification process now
  3856 contains a proof context (cf. Simplifier.the_context), which is the
  3857 very context that the initial simpset has been retrieved from (by
  3858 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3859 (solver, looper etc.) may depend on arbitrary proof data.
  3860 
  3861 * Simplifier.inherit_context inherits the proof context (plus the
  3862 local bounds) of the current simplification process; any simproc
  3863 etc. that calls the Simplifier recursively should do this!  Removed
  3864 former Simplifier.inherit_bounds, which is already included here --
  3865 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3866 specify an explicit context using Simplifier.context/theory_context.
  3867 
  3868 * Simplifier/Classical Reasoner: more abstract interfaces
  3869 change_simpset/claset for modifying the simpset/claset reference of a
  3870 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3871 INCOMPATIBILITY.
  3872 
  3873 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3874 "Trueprop" etc.
  3875 
  3876 
  3877 *** System ***
  3878 
  3879 * settings: the default heap location within ISABELLE_HOME_USER now
  3880 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3881 Isabelle installations.
  3882 
  3883 * isabelle-process: option -S (secure mode) disables some critical
  3884 operations, notably runtime compilation and evaluation of ML source
  3885 code.
  3886 
  3887 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3888 
  3889 * Support for parallel execution, using native multicore support of
  3890 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3891 independent theories, according to the given theory header
  3892 specifications. The maximum number of worker threads is specified via
  3893 usedir option -M or the "max-threads" setting in Proof General. A
  3894 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3895 to 6 on a 8-core machine.  User-code needs to observe certain
  3896 guidelines for thread-safe programming, see appendix A in the Isar
  3897 Implementation manual.
  3898 
  3899 
  3900 
  3901 New in Isabelle2005 (October 2005)
  3902 ----------------------------------
  3903 
  3904 *** General ***
  3905 
  3906 * Theory headers: the new header syntax for Isar theories is
  3907 
  3908   theory <name>
  3909   imports <theory1> ... <theoryN>
  3910   uses <file1> ... <fileM>
  3911   begin
  3912 
  3913 where the 'uses' part is optional.  The previous syntax
  3914 
  3915   theory <name> = <theory1> + ... + <theoryN>:
  3916 
  3917 will disappear in the next release.  Use isatool fixheaders to convert
  3918 existing theory files.  Note that there is no change in ancient
  3919 non-Isar theories now, but these will disappear soon.
  3920 
  3921 * Theory loader: parent theories can now also be referred to via
  3922 relative and absolute paths.
  3923 
  3924 * Command 'find_theorems' searches for a list of criteria instead of a
  3925 list of constants. Known criteria are: intro, elim, dest, name:string,
  3926 simp:term, and any term. Criteria can be preceded by '-' to select
  3927 theorems that do not match. Intro, elim, dest select theorems that
  3928 match the current goal, name:s selects theorems whose fully qualified
  3929 name contain s, and simp:term selects all simplification rules whose
  3930 lhs match term.  Any other term is interpreted as pattern and selects
  3931 all theorems matching the pattern. Available in ProofGeneral under
  3932 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3933 
  3934   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3935 
  3936 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3937 matching the current goal as introduction rule and not having "HOL."
  3938 in their name (i.e. not being defined in theory HOL).
  3939 
  3940 * Command 'thms_containing' has been discontinued in favour of
  3941 'find_theorems'; INCOMPATIBILITY.
  3942 
  3943 * Communication with Proof General is now 8bit clean, which means that
  3944 Unicode text in UTF-8 encoding may be used within theory texts (both
  3945 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3946 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3947 
  3948   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3949   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3950 
  3951 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3952 Classical Reasoner.  Typical big applications run around 2 times
  3953 faster.
  3954 
  3955 
  3956 *** Document preparation ***
  3957 
  3958 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3959 of raw sources.  Only those symbols that do not require additional
  3960 LaTeX packages (depending on comments in isabellesym.sty) are
  3961 displayed properly, everything else is left verbatim.  isatool display
  3962 and isatool print are used as front ends (these are subject to the
  3963 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3964 
  3965 * Command tags control specific markup of certain regions of text,
  3966 notably folding and hiding.  Predefined tags include "theory" (for
  3967 theory begin and end), "proof" for proof commands, and "ML" for
  3968 commands involving ML code; the additional tags "visible" and
  3969 "invisible" are unused by default.  Users may give explicit tag
  3970 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3971 interpretation of tags is determined by the LaTeX job during document
  3972 preparation: see option -V of isatool usedir, or options -n and -t of
  3973 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3974 \isadroptag.
  3975 
  3976 Several document versions may be produced at the same time via isatool
  3977 usedir (the generated index.html will link all of them).  Typical
  3978 specifications include ''-V document=theory,proof,ML'' to present
  3979 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3980 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3981 these parts without any formal replacement text.  The Isabelle site
  3982 default settings produce ''document'' and ''outline'' versions as
  3983 specified above.
  3984 
  3985 * Several new antiquotations:
  3986 
  3987   @{term_type term} prints a term with its type annotated;
  3988 
  3989   @{typeof term} prints the type of a term;
  3990 
  3991   @{const const} is the same as @{term const}, but checks that the
  3992   argument is a known logical constant;
  3993 
  3994   @{term_style style term} and @{thm_style style thm} print a term or
  3995   theorem applying a "style" to it
  3996 
  3997   @{ML text}
  3998 
  3999 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4000 definitions, equations, inequations etc., 'concl' printing only the
  4001 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4002 to print the specified premise.  TermStyle.add_style provides an ML
  4003 interface for introducing further styles.  See also the "LaTeX Sugar"
  4004 document practical applications.  The ML antiquotation prints
  4005 type-checked ML expressions verbatim.
  4006 
  4007 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4008 and 'text' support optional locale specification '(in loc)', which
  4009 specifies the default context for interpreting antiquotations.  For
  4010 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4011 
  4012 * Option 'locale=NAME' of antiquotations specifies an alternative
  4013 context interpreting the subsequent argument.  For example: @{thm
  4014 [locale=lattice] inf_assoc}.
  4015 
  4016 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4017 a proof context.
  4018 
  4019 * Proper output of antiquotations for theory commands involving a
  4020 proof context (such as 'locale' or 'theorem (in loc) ...').
  4021 
  4022 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4023 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4024 
  4025 * isatool usedir: new option -C (default true) controls whether option
  4026 -D should include a copy of the original document directory; -C false
  4027 prevents unwanted effects such as copying of administrative CVS data.
  4028 
  4029 
  4030 *** Pure ***
  4031 
  4032 * Considerably improved version of 'constdefs' command.  Now performs
  4033 automatic type-inference of declared constants; additional support for
  4034 local structure declarations (cf. locales and HOL records), see also
  4035 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4036 sequential dependencies of definitions within a single 'constdefs'
  4037 section; moreover, the declared name needs to be an identifier.  If
  4038 all fails, consider to fall back on 'consts' and 'defs' separately.
  4039 
  4040 * Improved indexed syntax and implicit structures.  First of all,
  4041 indexed syntax provides a notational device for subscripted
  4042 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4043 expressions.  Secondly, in a local context with structure
  4044 declarations, number indexes \<^sub>n or the empty index (default
  4045 number 1) refer to a certain fixed variable implicitly; option
  4046 show_structs controls printing of implicit structures.  Typical
  4047 applications of these concepts involve record types and locales.
  4048 
  4049 * New command 'no_syntax' removes grammar declarations (and
  4050 translations) resulting from the given syntax specification, which is
  4051 interpreted in the same manner as for the 'syntax' command.
  4052 
  4053 * 'Advanced' translation functions (parse_translation etc.) may depend
  4054 on the signature of the theory context being presently used for
  4055 parsing/printing, see also isar-ref manual.
  4056 
  4057 * Improved 'oracle' command provides a type-safe interface to turn an
  4058 ML expression of type theory -> T -> term into a primitive rule of
  4059 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4060 is already included here); see also FOL/ex/IffExample.thy;
  4061 INCOMPATIBILITY.
  4062 
  4063 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4064 before); "cI" is no longer bound, use "c.intro" instead.
  4065 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4066 axclasses vs. locales.
  4067 
  4068 * Improved internal renaming of symbolic identifiers -- attach primes
  4069 instead of base 26 numbers.
  4070 
  4071 * New flag show_question_marks controls printing of leading question
  4072 marks in schematic variable names.
  4073 
  4074 * In schematic variable names, *any* symbol following \<^isub> or
  4075 \<^isup> is now treated as part of the base name.  For example, the
  4076 following works without printing of awkward ".0" indexes:
  4077 
  4078   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4079     by simp
  4080 
  4081 * Inner syntax includes (*(*nested*) comments*).
  4082 
  4083 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4084 annotations as "(00...)".
  4085 
  4086 * Clear separation of logical types and nonterminals, where the latter
  4087 may only occur in 'syntax' specifications or type abbreviations.
  4088 Before that distinction was only partially implemented via type class
  4089 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4090 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4091 exotic syntax specifications may require further adaption
  4092 (e.g. Cube/Cube.thy).
  4093 
  4094 * Removed obsolete type class "logic", use the top sort {} instead.
  4095 Note that non-logical types should be declared as 'nonterminals'
  4096 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4097 specifications.
  4098 
  4099 * Attributes 'induct' and 'cases': type or set names may now be
  4100 locally fixed variables as well.
  4101 
  4102 * Simplifier: can now control the depth to which conditional rewriting
  4103 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4104 Limit.
  4105 
  4106 * Simplifier: simplification procedures may now take the current
  4107 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4108 interface), which is very useful for calling the Simplifier
  4109 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4110 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4111 low-level mk_simproc no longer applies Logic.varify internally, to
  4112 allow for use in a context of fixed variables.
  4113 
  4114 * thin_tac now works even if the assumption being deleted contains !!
  4115 or ==>.  More generally, erule now works even if the major premise of
  4116 the elimination rule contains !! or ==>.
  4117 
  4118 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4119 
  4120 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4121 from Pure, which contains all common declarations already.  Both
  4122 theories are defined via plain Isabelle/Isar .thy files.
  4123 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4124 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4125 use isatool fixcpure to adapt your theory and ML sources.
  4126 
  4127 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4128 selections of theorems in named facts via index ranges.
  4129 
  4130 * 'print_theorems': in theory mode, really print the difference
  4131 wrt. the last state (works for interactive theory development only),
  4132 in proof mode print all local facts (cf. 'print_facts');
  4133 
  4134 * 'hide': option '(open)' hides only base names.
  4135 
  4136 * More efficient treatment of intermediate checkpoints in interactive
  4137 theory development.
  4138 
  4139 * Code generator is now invoked via code_module (incremental code
  4140 generation) and code_library (modular code generation, ML structures
  4141 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4142 must be quoted when used as identifiers.
  4143 
  4144 * New 'value' command for reading, evaluating and printing terms using
  4145 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4146 quoted when used as identifier.
  4147 
  4148 
  4149 *** Locales ***
  4150 
  4151 * New commands for the interpretation of locale expressions in
  4152 theories (1), locales (2) and proof contexts (3).  These generate
  4153 proof obligations from the expression specification.  After the
  4154 obligations have been discharged, theorems of the expression are added
  4155 to the theory, target locale or proof context.  The synopsis of the
  4156 commands is a follows:
  4157 
  4158   (1) interpretation expr inst
  4159   (2) interpretation target < expr
  4160   (3) interpret expr inst
  4161 
  4162 Interpretation in theories and proof contexts require a parameter
  4163 instantiation of terms from the current context.  This is applied to
  4164 specifications and theorems of the interpreted expression.
  4165 Interpretation in locales only permits parameter renaming through the
  4166 locale expression.  Interpretation is smart in that interpretations
  4167 that are active already do not occur in proof obligations, neither are
  4168 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4169 inspect active interpretations of a particular locale.  For details,
  4170 see the Isar Reference manual.  Examples can be found in
  4171 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4172 
  4173 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4174 'interpret' instead.
  4175 
  4176 * New context element 'constrains' for adding type constraints to
  4177 parameters.
  4178 
  4179 * Context expressions: renaming of parameters with syntax
  4180 redeclaration.
  4181 
  4182 * Locale declaration: 'includes' disallowed.
  4183 
  4184 * Proper static binding of attribute syntax -- i.e. types / terms /
  4185 facts mentioned as arguments are always those of the locale definition
  4186 context, independently of the context of later invocations.  Moreover,
  4187 locale operations (renaming and type / term instantiation) are applied
  4188 to attribute arguments as expected.
  4189 
  4190 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4191 actual attributes; rare situations may require Attrib.attribute to
  4192 embed those attributes into Attrib.src that lack concrete syntax.
  4193 Attribute implementations need to cooperate properly with the static
  4194 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4195 Attrib.XXX_thm etc. already do the right thing without further
  4196 intervention.  Only unusual applications -- such as "where" or "of"
  4197 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4198 on the context and the facts involved -- may have to assign parsed
  4199 values to argument tokens explicitly.
  4200 
  4201 * Changed parameter management in theorem generation for long goal
  4202 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4203 theorem statement in rare situations.
  4204 
  4205 * Locale inspection command 'print_locale' omits notes elements.  Use
  4206 'print_locale!' to have them included in the output.
  4207 
  4208 
  4209 *** Provers ***
  4210 
  4211 * Provers/hypsubst.ML: improved version of the subst method, for
  4212 single-step rewriting: it now works in bound variable contexts. New is
  4213 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4214 rewrite a different subterm than the original subst method, which is
  4215 still available as 'simplesubst'.
  4216 
  4217 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4218 and quasi orders.
  4219 
  4220 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4221 reflexive-transitive closure of relations.
  4222 
  4223 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4224 limit (previously hard-coded with a value of 20) user-definable.
  4225 
  4226 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4227 is peformed already.  Object-logics merely need to finish their
  4228 initial simpset configuration as before.  INCOMPATIBILITY.
  4229 
  4230 
  4231 *** HOL ***
  4232 
  4233 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4234 
  4235   syntax (epsilon)
  4236     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4237 
  4238 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4239 and x-symbol; use option '-m epsilon' to get it actually printed.
  4240 Moreover, the mathematically important symbolic identifier \<epsilon>
  4241 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4242 
  4243 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4244 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4245 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4246 support corresponding Isar calculations.
  4247 
  4248 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4249 instead of ":".
  4250 
  4251 * theory SetInterval: changed the syntax for open intervals:
  4252 
  4253   Old       New
  4254   {..n(}    {..<n}
  4255   {)n..}    {n<..}
  4256   {m..n(}   {m..<n}
  4257   {)m..n}   {m<..n}
  4258   {)m..n(}  {m<..<n}
  4259 
  4260 The old syntax is still supported but will disappear in the next
  4261 release.  For conversion use the following Emacs search and replace
  4262 patterns (these are not perfect but work quite well):
  4263 
  4264   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4265   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4266 
  4267 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4268 equalities in commutative rings; method 'algebra' provides a generic
  4269 interface.
  4270 
  4271 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4272 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4273 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4274 be a tuple pattern.
  4275 
  4276 Some new syntax forms are available:
  4277 
  4278   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4279   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4280   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4281   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4282 
  4283 The latter form "\<Sum>x < k. e" used to be based on a separate
  4284 function "Summation", which has been discontinued.
  4285 
  4286 * theory Finite_Set: in structured induction proofs, the insert case
  4287 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4288 (insert F x)'.
  4289 
  4290 * The 'refute' command has been extended to support a much larger
  4291 fragment of HOL, including axiomatic type classes, constdefs and
  4292 typedefs, inductive datatypes and recursion.
  4293 
  4294 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4295 Requires zChaff with proof generation to be installed.  See
  4296 HOL/ex/SAT_Examples.thy for examples.
  4297 
  4298 * Datatype induction via method 'induct' now preserves the name of the
  4299 induction variable. For example, when proving P(xs::'a list) by
  4300 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4301 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4302 in unstructured proof scripts.
  4303 
  4304 * Reworked implementation of records.  Improved scalability for
  4305 records with many fields, avoiding performance problems for type
  4306 inference. Records are no longer composed of nested field types, but
  4307 of nested extension types. Therefore the record type only grows linear
  4308 in the number of extensions and not in the number of fields.  The
  4309 top-level (users) view on records is preserved.  Potential
  4310 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4311 old record representation. The type generated for a record is called
  4312 <record_name>_ext_type.
  4313 
  4314 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4315 proofs triggered by a record definition or a simproc (if
  4316 quick_and_dirty is enabled).  Definitions of large records can take
  4317 quite long.
  4318 
  4319 New simproc record_upd_simproc for simplification of multiple record
  4320 updates enabled by default.  Moreover, trivial updates are also
  4321 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4322 occasionally, since simplification is more powerful by default.
  4323 
  4324 * typedef: proper support for polymorphic sets, which contain extra
  4325 type-variables in the term.
  4326 
  4327 * Simplifier: automatically reasons about transitivity chains
  4328 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4329 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4330 old proofs break occasionally as simplification may now solve more
  4331 goals than previously.
  4332 
  4333 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4334 present.  Works for all partial orders (class "order"), in particular
  4335 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4336 just like y <= x.
  4337 
  4338 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4339 bound variable or a constant then the let is unfolded.  Otherwise
  4340 first a is simplified to b, and then f b is simplified to g. If
  4341 possible we abstract b from g arriving at "let x = b in h x",
  4342 otherwise we unfold the let and arrive at g.  The simproc can be
  4343 enabled/disabled by the reference use_let_simproc.  Potential
  4344 INCOMPATIBILITY since simplification is more powerful by default.
  4345 
  4346 * Classical reasoning: the meson method now accepts theorems as arguments.
  4347 
  4348 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4349 jobs to provide advice on the provability of subgoals.
  4350 
  4351 * Theory OrderedGroup and Ring_and_Field: various additions and
  4352 improvements to faciliate calculations involving equalities and
  4353 inequalities.
  4354 
  4355 The following theorems have been eliminated or modified
  4356 (INCOMPATIBILITY):
  4357 
  4358   abs_eq             now named abs_of_nonneg
  4359   abs_of_ge_0        now named abs_of_nonneg
  4360   abs_minus_eq       now named abs_of_nonpos
  4361   imp_abs_id         now named abs_of_nonneg
  4362   imp_abs_neg_id     now named abs_of_nonpos
  4363   mult_pos           now named mult_pos_pos
  4364   mult_pos_le        now named mult_nonneg_nonneg
  4365   mult_pos_neg_le    now named mult_nonneg_nonpos
  4366   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4367   mult_neg           now named mult_neg_neg
  4368   mult_neg_le        now named mult_nonpos_nonpos
  4369 
  4370 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4371      
  4372      zero_le_square
  4373      not_square_less_zero 
  4374 
  4375   The following lemmas have been deleted from Real/RealPow:
  4376   
  4377      realpow_zero_zero
  4378      realpow_two
  4379      realpow_less
  4380      zero_le_power
  4381      realpow_two_le
  4382      abs_realpow_two
  4383      realpow_two_abs     
  4384 
  4385 * Theory Parity: added rules for simplifying exponents.
  4386 
  4387 * Theory List:
  4388 
  4389 The following theorems have been eliminated or modified
  4390 (INCOMPATIBILITY):
  4391 
  4392   list_all_Nil       now named list_all.simps(1)
  4393   list_all_Cons      now named list_all.simps(2)
  4394   list_all_conv      now named list_all_iff
  4395   set_mem_eq         now named mem_iff
  4396 
  4397 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4398 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4399 
  4400 
  4401 *** HOL-Complex ***
  4402 
  4403 * Theory RealDef: better support for embedding natural numbers and
  4404 integers in the reals.
  4405 
  4406 The following theorems have been eliminated or modified
  4407 (INCOMPATIBILITY):
  4408 
  4409   exp_ge_add_one_self  now requires no hypotheses
  4410   real_of_int_add      reversed direction of equality (use [symmetric])
  4411   real_of_int_minus    reversed direction of equality (use [symmetric])
  4412   real_of_int_diff     reversed direction of equality (use [symmetric])
  4413   real_of_int_mult     reversed direction of equality (use [symmetric])
  4414 
  4415 * Theory RComplete: expanded support for floor and ceiling functions.
  4416 
  4417 * Theory Ln is new, with properties of the natural logarithm
  4418 
  4419 * Hyperreal: There is a new type constructor "star" for making
  4420 nonstandard types.  The old type names are now type synonyms:
  4421 
  4422   hypreal = real star
  4423   hypnat = nat star
  4424   hcomplex = complex star
  4425 
  4426 * Hyperreal: Many groups of similarly-defined constants have been
  4427 replaced by polymorphic versions (INCOMPATIBILITY):
  4428 
  4429   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4430 
  4431   starset      <-- starsetNat, starsetC
  4432   *s*          <-- *sNat*, *sc*
  4433   starset_n    <-- starsetNat_n, starsetC_n
  4434   *sn*         <-- *sNatn*, *scn*
  4435   InternalSets <-- InternalNatSets, InternalCSets
  4436 
  4437   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4438   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4439   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4440   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4441   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4442 
  4443 * Hyperreal: Many type-specific theorems have been removed in favor of
  4444 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4445 
  4446   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4447   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4448   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4449   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4450   right_minus <-- hypreal_add_minus
  4451   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4452   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4453   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4454   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4455   mult_1_right <-- hcomplex_mult_one_right
  4456   mult_zero_left <-- hcomplex_mult_zero_left
  4457   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4458   right_distrib <-- hypnat_add_mult_distrib2
  4459   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4460   right_inverse <-- hypreal_mult_inverse
  4461   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4462   order_refl <-- {hypreal,hypnat}_le_refl
  4463   order_trans <-- {hypreal,hypnat}_le_trans
  4464   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4465   order_less_le <-- {hypreal,hypnat}_less_le
  4466   linorder_linear <-- {hypreal,hypnat}_le_linear
  4467   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4468   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4469   add_nonneg_nonneg <-- hypreal_le_add_order
  4470 
  4471 * Hyperreal: Separate theorems having to do with type-specific
  4472 versions of constants have been merged into theorems that apply to the
  4473 new polymorphic constants (INCOMPATIBILITY):
  4474 
  4475   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4476   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4477   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4478   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4479   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4480   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4481   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4482   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4483   STAR_diff <-- {STAR,STARC}_diff
  4484   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4485     STARC_hcomplex_of_complex}_image_subset
  4486   starset_n_Un <-- starset{Nat,C}_n_Un
  4487   starset_n_Int <-- starset{Nat,C}_n_Int
  4488   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4489   starset_n_diff <-- starset{Nat,C}_n_diff
  4490   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4491   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4492   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4493   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4494   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4495   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4496   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4497   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4498   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4499   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4500   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4501   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4502   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4503   starfun_diff <-- starfun{C,RC,CR}_diff
  4504   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4505   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4506   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4507   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4508   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4509   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4510   starfun_Id <-- starfunC_Id
  4511   starfun_approx <-- starfun{Nat,CR}_approx
  4512   starfun_capprox <-- starfun{C,RC}_capprox
  4513   starfun_abs <-- starfunNat_rabs
  4514   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4515   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4516   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4517   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4518   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4519   starfun_add_approx <-- starfunCR_add_approx
  4520   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4521   starfun_divide <-- starfun{C,CR,RC}_divide
  4522   starfun_n <-- starfun{Nat,C}_n
  4523   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4524   starfun_n_add <-- starfun{Nat,C}_n_add
  4525   starfun_n_add_minus <-- starfunNat_n_add_minus
  4526   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4527   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4528   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4529 
  4530   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4531   star_n_minus <-- {hypreal,hcomplex}_minus
  4532   star_n_diff <-- {hypreal,hcomplex}_diff
  4533   star_n_mult <-- {hypreal,hcomplex}_mult
  4534   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4535   star_n_le <-- {hypreal,hypnat}_le
  4536   star_n_less <-- {hypreal,hypnat}_less
  4537   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4538   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4539   star_n_abs <-- hypreal_hrabs
  4540   star_n_divide <-- hcomplex_divide
  4541 
  4542   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4543   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4544   star_of_diff <-- hypreal_of_real_diff
  4545   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4546   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4547   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4548   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4549   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4550   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4551   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4552   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4553   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4554   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4555   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4556   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4557   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4558   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4559   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4560   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4561   star_of_power <-- hypreal_of_real_power
  4562   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4563 
  4564 * Hyperreal: new method "transfer" that implements the transfer
  4565 principle of nonstandard analysis. With a subgoal that mentions
  4566 nonstandard types like "'a star", the command "apply transfer"
  4567 replaces it with an equivalent one that mentions only standard types.
  4568 To be successful, all free variables must have standard types; non-
  4569 standard variables must have explicit universal quantifiers.
  4570 
  4571 * Hyperreal: A theory of Taylor series.
  4572 
  4573 
  4574 *** HOLCF ***
  4575 
  4576 * Discontinued special version of 'constdefs' (which used to support
  4577 continuous functions) in favor of the general Pure one with full
  4578 type-inference.
  4579 
  4580 * New simplification procedure for solving continuity conditions; it
  4581 is much faster on terms with many nested lambda abstractions (cubic
  4582 instead of exponential time).
  4583 
  4584 * New syntax for domain package: selector names are now optional.
  4585 Parentheses should be omitted unless argument is lazy, for example:
  4586 
  4587   domain 'a stream = cons "'a" (lazy "'a stream")
  4588 
  4589 * New command 'fixrec' for defining recursive functions with pattern
  4590 matching; defining multiple functions with mutual recursion is also
  4591 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4592 sinr, or any data constructor defined by the domain package. The given
  4593 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4594 syntax and examples.
  4595 
  4596 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4597 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4598 but the proof obligation additionally includes an admissibility
  4599 requirement. The packages generate instances of class cpo or pcpo,
  4600 with continuity and strictness theorems for Rep and Abs.
  4601 
  4602 * HOLCF: Many theorems have been renamed according to a more standard naming
  4603 scheme (INCOMPATIBILITY):
  4604 
  4605   foo_inject:  "foo$x = foo$y ==> x = y"
  4606   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4607   foo_less:    "(foo$x << foo$y) = (x << y)"
  4608   foo_strict:  "foo$UU = UU"
  4609   foo_defined: "... ==> foo$x ~= UU"
  4610   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4611 
  4612 
  4613 *** ZF ***
  4614 
  4615 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4616 including the First Isomorphism Theorem (on quotienting by the kernel
  4617 of a homomorphism).
  4618 
  4619 * ZF/Simplifier: install second copy of type solver that actually
  4620 makes use of TC rules declared to Isar proof contexts (or locales);
  4621 the old version is still required for ML proof scripts.
  4622 
  4623 
  4624 *** Cube ***
  4625 
  4626 * Converted to Isar theory format; use locales instead of axiomatic
  4627 theories.
  4628 
  4629 
  4630 *** ML ***
  4631 
  4632 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4633 for ||>, ||>>, |>>,
  4634 
  4635 * Pure/library.ML no longer defines its own option datatype, but uses
  4636 that of the SML basis, which has constructors NONE and SOME instead of
  4637 None and Some, as well as exception Option.Option instead of OPTION.
  4638 The functions the, if_none, is_some, is_none have been adapted
  4639 accordingly, while Option.map replaces apsome.
  4640 
  4641 * Pure/library.ML: the exception LIST has been given up in favour of
  4642 the standard exceptions Empty and Subscript, as well as
  4643 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4644 superceded by the standard hd and tl functions etc.
  4645 
  4646 A number of basic list functions are no longer exported to the ML
  4647 toplevel, as they are variants of predefined functions.  The following
  4648 suggests how one can translate existing code:
  4649 
  4650     rev_append xs ys = List.revAppend (xs, ys)
  4651     nth_elem (i, xs) = List.nth (xs, i)
  4652     last_elem xs = List.last xs
  4653     flat xss = List.concat xss
  4654     seq fs = List.app fs
  4655     partition P xs = List.partition P xs
  4656     mapfilter f xs = List.mapPartial f xs
  4657 
  4658 * Pure/library.ML: several combinators for linear functional
  4659 transformations, notably reverse application and composition:
  4660 
  4661   x |> f                f #> g
  4662   (x, y) |-> f          f #-> g
  4663 
  4664 * Pure/library.ML: introduced/changed precedence of infix operators:
  4665 
  4666   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4667   infix 2 ?;
  4668   infix 3 o oo ooo oooo;
  4669   infix 4 ~~ upto downto;
  4670 
  4671 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4672 infix operators.
  4673 
  4674 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4675 fold_map support linear functional transformations and nesting.  For
  4676 example:
  4677 
  4678   fold f [x1, ..., xN] y =
  4679     y |> f x1 |> ... |> f xN
  4680 
  4681   (fold o fold) f [xs1, ..., xsN] y =
  4682     y |> fold f xs1 |> ... |> fold f xsN
  4683 
  4684   fold f [x1, ..., xN] =
  4685     f x1 #> ... #> f xN
  4686 
  4687   (fold o fold) f [xs1, ..., xsN] =
  4688     fold f xs1 #> ... #> fold f xsN
  4689 
  4690 * Pure/library.ML: the following selectors on type 'a option are
  4691 available:
  4692 
  4693   the:               'a option -> 'a  (*partial*)
  4694   these:             'a option -> 'a  where 'a = 'b list
  4695   the_default: 'a -> 'a option -> 'a
  4696   the_list:          'a option -> 'a list
  4697 
  4698 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4699 basic operations for association lists, following natural argument
  4700 order; moreover the explicit equality predicate passed here avoids
  4701 potentially expensive polymorphic runtime equality checks.
  4702 The old functions may be expressed as follows:
  4703 
  4704   assoc = uncurry (AList.lookup (op =))
  4705   assocs = these oo AList.lookup (op =)
  4706   overwrite = uncurry (AList.update (op =)) o swap
  4707 
  4708 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4709 
  4710   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4711   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4712 
  4713 replacing make_keylist and keyfilter (occassionally used)
  4714 Naive rewrites:
  4715 
  4716   make_keylist = AList.make
  4717   keyfilter = AList.find (op =)
  4718 
  4719 * eq_fst and eq_snd now take explicit equality parameter, thus
  4720   avoiding eqtypes. Naive rewrites:
  4721 
  4722     eq_fst = eq_fst (op =)
  4723     eq_snd = eq_snd (op =)
  4724 
  4725 * Removed deprecated apl and apr (rarely used).
  4726   Naive rewrites:
  4727 
  4728     apl (n, op) =>>= curry op n
  4729     apr (op, m) =>>= fn n => op (n, m)
  4730 
  4731 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4732 provides a reasonably efficient light-weight implementation of sets as
  4733 lists.
  4734 
  4735 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4736 few new operations; existing lookup and update are now curried to
  4737 follow natural argument order (for use with fold etc.);
  4738 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4739 
  4740 * Pure/General: output via the Isabelle channels of
  4741 writeln/warning/error etc. is now passed through Output.output, with a
  4742 hook for arbitrary transformations depending on the print_mode
  4743 (cf. Output.add_mode -- the first active mode that provides a output
  4744 function wins).  Already formatted output may be embedded into further
  4745 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4746 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4747 accommodate easy composition of diagnostic messages etc.  Programmers
  4748 rarely need to care about Output.output or Output.raw at all, with
  4749 some notable exceptions: Output.output is required when bypassing the
  4750 standard channels (writeln etc.), or in token translations to produce
  4751 properly formatted results; Output.raw is required when capturing
  4752 already output material that will eventually be presented to the user
  4753 a second time.  For the default print mode, both Output.output and
  4754 Output.raw have no effect.
  4755 
  4756 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4757 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4758 cumulative results are displayed at the end of a batch session.
  4759 
  4760 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4761 replaced by File.platform_path and File.shell_path (with appropriate
  4762 hooks).  This provides a clean interface for unusual systems where the
  4763 internal and external process view of file names are different.
  4764 
  4765 * Pure: more efficient orders for basic syntactic entities: added
  4766 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4767 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4768 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4769 orders now -- potential INCOMPATIBILITY for code that depends on a
  4770 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4771 Library.sort_strings on result).
  4772 
  4773 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4774 fold_types traverse types/terms from left to right, observing natural
  4775 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4776 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4777 
  4778 * Pure: name spaces have been refined, with significant changes of the
  4779 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4780 to extern(_table).  The plain name entry path is superceded by a
  4781 general 'naming' context, which also includes the 'policy' to produce
  4782 a fully qualified name and external accesses of a fully qualified
  4783 name; NameSpace.extend is superceded by context dependent
  4784 Sign.declare_name.  Several theory and proof context operations modify
  4785 the naming context.  Especially note Theory.restore_naming and
  4786 ProofContext.restore_naming to get back to a sane state; note that
  4787 Theory.add_path is no longer sufficient to recover from
  4788 Theory.absolute_path in particular.
  4789 
  4790 * Pure: new flags short_names (default false) and unique_names
  4791 (default true) for controlling output of qualified names.  If
  4792 short_names is set, names are printed unqualified.  If unique_names is
  4793 reset, the name prefix is reduced to the minimum required to achieve
  4794 the original result when interning again, even if there is an overlap
  4795 with earlier declarations.
  4796 
  4797 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4798 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4799 (useful for printing error messages).  INCOMPATIBILITY.
  4800 
  4801 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4802 Theory.theory are now identified, referring to the universal
  4803 Context.theory (see Pure/context.ML).  Actual signature and theory
  4804 content is managed as theory data.  The old code and interfaces were
  4805 spread over many files and structures; the new arrangement introduces
  4806 considerable INCOMPATIBILITY to gain more clarity:
  4807 
  4808   Context -- theory management operations (name, identity, inclusion,
  4809     parents, ancestors, merge, etc.), plus generic theory data;
  4810 
  4811   Sign -- logical signature and syntax operations (declaring consts,
  4812     types, etc.), plus certify/read for common entities;
  4813 
  4814   Theory -- logical theory operations (stating axioms, definitions,
  4815     oracles), plus a copy of logical signature operations (consts,
  4816     types, etc.); also a few basic management operations (Theory.copy,
  4817     Theory.merge, etc.)
  4818 
  4819 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4820 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4821 for convenience -- they merely return the theory.
  4822 
  4823 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4824 
  4825 * Pure: the Isar proof context type is already defined early in Pure
  4826 as Context.proof (note that ProofContext.context and Proof.context are
  4827 aliases, where the latter is the preferred name).  This enables other
  4828 Isabelle components to refer to that type even before Isar is present.
  4829 
  4830 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4831 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4832 any of these kinds.  For example, Sign.intern typeK is now
  4833 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4834 Theory.hide_types.  Also note that former
  4835 Theory.hide_classes/types/consts are now
  4836 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4837 internalize their arguments!  INCOMPATIBILITY.
  4838 
  4839 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4840 datatype thmref (with constructors Name and NameSelection) instead of
  4841 plain string -- INCOMPATIBILITY;
  4842 
  4843 * Pure: cases produced by proof methods specify options, where NONE
  4844 means to remove case bindings -- INCOMPATIBILITY in
  4845 (RAW_)METHOD_CASES.
  4846 
  4847 * Pure: the following operations retrieve axioms or theorems from a
  4848 theory node or theory hierarchy, respectively:
  4849 
  4850   Theory.axioms_of: theory -> (string * term) list
  4851   Theory.all_axioms_of: theory -> (string * term) list
  4852   PureThy.thms_of: theory -> (string * thm) list
  4853   PureThy.all_thms_of: theory -> (string * thm) list
  4854 
  4855 * Pure: print_tac now outputs the goal through the trace channel.
  4856 
  4857 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4858 Reference Toplevel.debug (default false) controls detailed printing
  4859 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4860 controls execution profiling -- set to 1 for time and 2 for space
  4861 (both increase the runtime).
  4862 
  4863 * Isar session: The initial use of ROOT.ML is now always timed,
  4864 i.e. the log will show the actual process times, in contrast to the
  4865 elapsed wall-clock time that the outer shell wrapper produces.
  4866 
  4867 * Simplifier: improved handling of bound variables (nameless
  4868 representation, avoid allocating new strings).  Simprocs that invoke
  4869 the Simplifier recursively should use Simplifier.inherit_bounds to
  4870 avoid local name clashes.  Failure to do so produces warnings
  4871 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4872 for further details.
  4873 
  4874 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4875 bindings for all theorems stored within a given theory; this may help
  4876 in porting non-Isar theories to Isar ones, while keeping ML proof
  4877 scripts for the time being.
  4878 
  4879 * ML operator HTML.with_charset specifies the charset begin used for
  4880 generated HTML files.  For example:
  4881 
  4882   HTML.with_charset "utf-8" use_thy "Hebrew";
  4883   HTML.with_charset "utf-8" use_thy "Chinese";
  4884 
  4885 
  4886 *** System ***
  4887 
  4888 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4889 isabelle, isatool etc.).
  4890 
  4891 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4892 isatool doc, isatool mkdir, display_drafts etc.).
  4893 
  4894 * isatool usedir: option -f allows specification of the ML file to be
  4895 used by Isabelle; default is ROOT.ML.
  4896 
  4897 * New isatool version outputs the version identifier of the Isabelle
  4898 distribution being used.
  4899 
  4900 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4901 (containing Boolean satisfiability problems) into Isabelle/HOL
  4902 theories.
  4903 
  4904 
  4905 
  4906 New in Isabelle2004 (April 2004)
  4907 --------------------------------
  4908 
  4909 *** General ***
  4910 
  4911 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4912   Replaces linorder.ML.
  4913 
  4914 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4915   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4916   (\<a>...\<z>), are now considered normal letters, and can therefore
  4917   be used anywhere where an ASCII letter (a...zA...Z) has until
  4918   now. COMPATIBILITY: This obviously changes the parsing of some
  4919   terms, especially where a symbol has been used as a binder, say
  4920   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4921   as an identifier.  Fix it by inserting a space around former
  4922   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4923   existing theory and ML files.
  4924 
  4925 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4926 
  4927 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4928   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4929   a normal (but invisible) letter. For multiple letter subscripts repeat
  4930   \<^isub> like this: x\<^isub>1\<^isub>2.
  4931 
  4932 * Pure: There are now sub-/superscripts that can span more than one
  4933   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4934   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4935   superscript. The new control characters are not identifier parts.
  4936 
  4937 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4938   content of "..." to the latex file instead of \isacntrl... . The "..."
  4939   may consist of any printable characters excluding the end bracket >.
  4940 
  4941 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4942   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4943   declare constants "final", which prevents their being given a definition
  4944   later.  It is useful for constants whose behaviour is fixed axiomatically
  4945   rather than definitionally, such as the meta-logic connectives.
  4946 
  4947 * Pure: 'instance' now handles general arities with general sorts
  4948   (i.e. intersections of classes),
  4949 
  4950 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4951   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4952   It can be changed to alter the colors/layout of generated pages.
  4953 
  4954 
  4955 *** Isar ***
  4956 
  4957 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4958   cut_tac, subgoal_tac and thin_tac:
  4959   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4960     locales are no longer forced to write Isar proof scripts.
  4961     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4962     emulations.
  4963   - INCOMPATIBILITY: names of variables to be instantiated may no
  4964     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4965     This is consistent with the instantiation attribute "where".
  4966 
  4967 * Attributes "where" and "of":
  4968   - Now take type variables of instantiated theorem into account when reading
  4969     the instantiation string.  This fixes a bug that caused instantiated
  4970     theorems to have too special types in some circumstances.
  4971   - "where" permits explicit instantiations of type variables.
  4972 
  4973 * Calculation commands "moreover" and "also" no longer interfere with
  4974   current facts ("this"), admitting arbitrary combinations with "then"
  4975   and derived forms.
  4976 
  4977 * Locales:
  4978   - Goal statements involving the context element "includes" no longer
  4979     generate theorems with internal delta predicates (those ending on
  4980     "_axioms") in the premise.
  4981     Resolve particular premise with <locale>.intro to obtain old form.
  4982   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4983     specification and "includes" elements in goal statement.
  4984   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4985     [intro?] and [elim?] (respectively) by default.
  4986   - Experimental command for instantiation of locales in proof contexts:
  4987         instantiate <label>[<attrs>]: <loc>
  4988     Instantiates locale <loc> and adds all its theorems to the current context
  4989     taking into account their attributes.  Label and attrs are optional
  4990     modifiers, like in theorem declarations.  If present, names of
  4991     instantiated theorems are qualified with <label>, and the attributes
  4992     <attrs> are applied after any attributes these theorems might have already.
  4993       If the locale has assumptions, a chained fact of the form
  4994     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4995     are derived.  The command does not support old-style locales declared
  4996     with "locale (open)".
  4997       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4998 
  4999 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5000   (Isar) contexts.
  5001 
  5002 
  5003 *** HOL ***
  5004 
  5005 * Proof import: new image HOL4 contains the imported library from
  5006   the HOL4 system with about 2500 theorems. It is imported by
  5007   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5008   can be used like any other Isabelle image.  See
  5009   HOL/Import/HOL/README for more information.
  5010 
  5011 * Simplifier:
  5012   - Much improved handling of linear and partial orders.
  5013     Reasoners for linear and partial orders are set up for type classes
  5014     "linorder" and "order" respectively, and are added to the default simpset
  5015     as solvers.  This means that the simplifier can build transitivity chains
  5016     to solve goals from the assumptions.
  5017   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5018     of blast or auto after simplification become unnecessary because the goal
  5019     is solved by simplification already.
  5020 
  5021 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5022     all proved in axiomatic type classes for semirings, rings and fields.
  5023 
  5024 * Numerics:
  5025   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5026     now formalized using the Ring_and_Field theory mentioned above.
  5027   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5028     than before, because now they are set up once in a generic manner.
  5029   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5030     Look for the general versions in Ring_and_Field (and Power if they concern
  5031     exponentiation).
  5032 
  5033 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5034 
  5035 * Records:
  5036   - Record types are now by default printed with their type abbreviation
  5037     instead of the list of all field types. This can be configured via
  5038     the reference "print_record_type_abbr".
  5039   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5040     (not enabled by default).
  5041   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5042     EX x. x = sel r to True (not enabled by default).
  5043   - Tactic "record_split_simp_tac" to split and simplify records added.
  5044 
  5045 * 'specification' command added, allowing for definition by
  5046   specification.  There is also an 'ax_specification' command that
  5047   introduces the new constants axiomatically.
  5048 
  5049 * arith(_tac) is now able to generate counterexamples for reals as well.
  5050 
  5051 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5052 
  5053 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5054   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5055 
  5056 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5057   matrix theory to linear programming.
  5058 
  5059 * Unions and Intersections:
  5060   The latex output syntax of UN and INT has been changed
  5061   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5062   i.e. the index formulae has become a subscript.
  5063   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5064 
  5065 * Unions and Intersections over Intervals:
  5066   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5067   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5068   like in normal math, and corresponding versions for < and for intersection.
  5069 
  5070 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5071   lexicographic dictonary ordering has been added as "lexord".
  5072 
  5073 * ML: the legacy theory structures Int and List have been removed. They had
  5074   conflicted with ML Basis Library structures having the same names.
  5075 
  5076 * 'refute' command added to search for (finite) countermodels.  Only works
  5077   for a fragment of HOL.  The installation of an external SAT solver is
  5078   highly recommended.  See "HOL/Refute.thy" for details.
  5079 
  5080 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5081   formulae under an assignment of free variables to random values.
  5082   In contrast to 'refute', it can deal with inductive datatypes,
  5083   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5084   for examples.
  5085 
  5086 
  5087 *** HOLCF ***
  5088 
  5089 * Streams now come with concatenation and are part of the HOLCF image
  5090 
  5091 
  5092 
  5093 New in Isabelle2003 (May 2003)
  5094 ------------------------------
  5095 
  5096 *** General ***
  5097 
  5098 * Provers/simplifier:
  5099 
  5100   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5101     Assumptions are now subject to complete mutual simplification,
  5102     not just from left to right. The simplifier now preserves
  5103     the order of assumptions.
  5104 
  5105     Potential INCOMPATIBILITY:
  5106 
  5107     -- simp sometimes diverges where the old version did
  5108        not, e.g. invoking simp on the goal
  5109 
  5110         [| P (f x); y = x; f x = f y |] ==> Q
  5111 
  5112        now gives rise to the infinite reduction sequence
  5113 
  5114         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5115 
  5116        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5117        kind of problem.
  5118 
  5119     -- Tactics combining classical reasoner and simplification (such as auto)
  5120        are also affected by this change, because many of them rely on
  5121        simp. They may sometimes diverge as well or yield a different numbers
  5122        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5123        in case of problems. Sometimes subsequent calls to the classical
  5124        reasoner will fail because a preceeding call to the simplifier too
  5125        eagerly simplified the goal, e.g. deleted redundant premises.
  5126 
  5127   - The simplifier trace now shows the names of the applied rewrite rules
  5128 
  5129   - You can limit the number of recursive invocations of the simplifier
  5130     during conditional rewriting (where the simplifie tries to solve the
  5131     conditions before applying the rewrite rule):
  5132     ML "simp_depth_limit := n"
  5133     where n is an integer. Thus you can force termination where previously
  5134     the simplifier would diverge.
  5135 
  5136   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5137 
  5138   - No longer aborts on failed congruence proof.  Instead, the
  5139     congruence is ignored.
  5140 
  5141 * Pure: New generic framework for extracting programs from constructive
  5142   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5143   as HOL/Extraction for some case studies.
  5144 
  5145 * Pure: The main goal of the proof state is no longer shown by default, only
  5146 the subgoals. This behaviour is controlled by a new flag.
  5147    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5148 (ML: Proof.show_main_goal).
  5149 
  5150 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5151 rules whose conclusion matches subgoal 1:
  5152       PG menu: Isabelle/Isar -> Show me -> matching rules
  5153 The rules are ordered by how closely they match the subgoal.
  5154 In particular, rules that solve a subgoal outright are displayed first
  5155 (or rather last, the way they are printed).
  5156 (ML: ProofGeneral.print_intros())
  5157 
  5158 * Pure: New flag trace_unify_fail causes unification to print
  5159 diagnostic information (PG: in trace buffer) when it fails. This is
  5160 useful for figuring out why single step proofs like rule, erule or
  5161 assumption failed.
  5162 
  5163 * Pure: Locale specifications now produce predicate definitions
  5164 according to the body of text (covering assumptions modulo local
  5165 definitions); predicate "loc_axioms" covers newly introduced text,
  5166 while "loc" is cumulative wrt. all included locale expressions; the
  5167 latter view is presented only on export into the global theory
  5168 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5169 on the old view without predicates;
  5170 
  5171 * Pure: predefined locales "var" and "struct" are useful for sharing
  5172 parameters (as in CASL, for example); just specify something like
  5173 ``var x + var y + struct M'' as import;
  5174 
  5175 * Pure: improved thms_containing: proper indexing of facts instead of
  5176 raw theorems; check validity of results wrt. current name space;
  5177 include local facts of proof configuration (also covers active
  5178 locales), cover fixed variables in index; may use "_" in term
  5179 specification; an optional limit for the number of printed facts may
  5180 be given (the default is 40);
  5181 
  5182 * Pure: disallow duplicate fact bindings within new-style theory files
  5183 (batch-mode only);
  5184 
  5185 * Provers: improved induct method: assumptions introduced by case
  5186 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5187 the goal statement); "foo" still refers to all facts collectively;
  5188 
  5189 * Provers: the function blast.overloaded has been removed: all constants
  5190 are regarded as potentially overloaded, which improves robustness in exchange
  5191 for slight decrease in efficiency;
  5192 
  5193 * Provers/linorder: New generic prover for transitivity reasoning over
  5194 linear orders.  Note: this prover is not efficient!
  5195 
  5196 * Isar: preview of problems to finish 'show' now produce an error
  5197 rather than just a warning (in interactive mode);
  5198 
  5199 
  5200 *** HOL ***
  5201 
  5202 * arith(_tac)
  5203 
  5204  - Produces a counter example if it cannot prove a goal.
  5205    Note that the counter example may be spurious if the goal is not a formula
  5206    of quantifier-free linear arithmetic.
  5207    In ProofGeneral the counter example appears in the trace buffer.
  5208 
  5209  - Knows about div k and mod k where k is a numeral of type nat or int.
  5210 
  5211  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5212    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5213    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5214 
  5215 * simp's arithmetic capabilities have been enhanced a bit: it now
  5216 takes ~= in premises into account (by performing a case split);
  5217 
  5218 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5219 are distributed over a sum of terms;
  5220 
  5221 * New tactic "trans_tac" and method "trans" instantiate
  5222 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5223 "<=", "<" and "=").
  5224 
  5225 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5226 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5227 
  5228 * 'typedef' command has new option "open" to suppress the set
  5229 definition;
  5230 
  5231 * functions Min and Max on finite sets have been introduced (theory
  5232 Finite_Set);
  5233 
  5234 * attribute [symmetric] now works for relations as well; it turns
  5235 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5236 
  5237 * induct over a !!-quantified statement (say !!x1..xn):
  5238   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5239 
  5240 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5241 %x. None. Warning: empty_def now refers to the previously hidden definition
  5242 of the empty set.
  5243 
  5244 * Algebra: formalization of classical algebra.  Intended as base for
  5245 any algebraic development in Isabelle.  Currently covers group theory
  5246 (up to Sylow's theorem) and ring theory (Universal Property of
  5247 Univariate Polynomials).  Contributions welcome;
  5248 
  5249 * GroupTheory: deleted, since its material has been moved to Algebra;
  5250 
  5251 * Complex: new directory of the complex numbers with numeric constants,
  5252 nonstandard complex numbers, and some complex analysis, standard and
  5253 nonstandard (Jacques Fleuriot);
  5254 
  5255 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5256 
  5257 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5258 Fleuriot);
  5259 
  5260 * Real/HahnBanach: updated and adapted to locales;
  5261 
  5262 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5263 Gray and Kramer);
  5264 
  5265 * UNITY: added the Meier-Sanders theory of progress sets;
  5266 
  5267 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5268 as abstract algorithms, instantiated to the JVM;
  5269 
  5270 * Bali: Java source language formalization. Type system, operational
  5271 semantics, axiomatic semantics. Supported language features:
  5272 classes, interfaces, objects,virtual methods, static methods,
  5273 static/instance fields, arrays, access modifiers, definite
  5274 assignment, exceptions.
  5275 
  5276 
  5277 *** ZF ***
  5278 
  5279 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5280 universe, etc.);
  5281 
  5282 * Main ZF: virtually all theories converted to new-style format;
  5283 
  5284 
  5285 *** ML ***
  5286 
  5287 * Pure: Tactic.prove provides sane interface for internal proofs;
  5288 omits the infamous "standard" operation, so this is more appropriate
  5289 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5290 
  5291 * Pure: improved error reporting of simprocs;
  5292 
  5293 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5294 up simprocs;
  5295 
  5296 
  5297 *** Document preparation ***
  5298 
  5299 * uses \par instead of \\ for line breaks in theory text. This may
  5300 shift some page breaks in large documents. To get the old behaviour
  5301 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5302 
  5303 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5304 other packages
  5305 
  5306 * \<euro> now needs package babel/greek instead of marvosym (which
  5307 broke \Rightarrow)
  5308 
  5309 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5310 textcomp package)
  5311 
  5312 
  5313 
  5314 New in Isabelle2002 (March 2002)
  5315 --------------------------------
  5316 
  5317 *** Document preparation ***
  5318 
  5319 * greatly simplified document preparation setup, including more
  5320 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5321 instructive isatool mkdir; users should basically be able to get
  5322 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5323 users may run a separate document processing stage manually like this:
  5324 "isatool usedir -D output HOL Test && isatool document Test/output";
  5325 
  5326 * theory dependency graph may now be incorporated into documents;
  5327 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5328 with \includegraphics of LaTeX;
  5329 
  5330 * proper spacing of consecutive markup elements, especially text
  5331 blocks after section headings;
  5332 
  5333 * support bold style (for single symbols only), input syntax is like
  5334 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5335 
  5336 * \<bullet> is now output as bold \cdot by default, which looks much
  5337 better in printed text;
  5338 
  5339 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5340 note that these symbols are currently unavailable in Proof General /
  5341 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5342 
  5343 * isatool latex no longer depends on changed TEXINPUTS, instead
  5344 isatool document copies the Isabelle style files to the target
  5345 location;
  5346 
  5347 
  5348 *** Isar ***
  5349 
  5350 * Pure/Provers: improved proof by cases and induction;
  5351   - 'case' command admits impromptu naming of parameters (such as
  5352     "case (Suc n)");
  5353   - 'induct' method divinates rule instantiation from the inductive
  5354     claim; no longer requires excessive ?P bindings for proper
  5355     instantiation of cases;
  5356   - 'induct' method properly enumerates all possibilities of set/type
  5357     rules; as a consequence facts may be also passed through *type*
  5358     rules without further ado;
  5359   - 'induct' method now derives symbolic cases from the *rulified*
  5360     rule (before it used to rulify cases stemming from the internal
  5361     atomized version); this means that the context of a non-atomic
  5362     statement becomes is included in the hypothesis, avoiding the
  5363     slightly cumbersome show "PROP ?case" form;
  5364   - 'induct' may now use elim-style induction rules without chaining
  5365     facts, using ``missing'' premises from the goal state; this allows
  5366     rules stemming from inductive sets to be applied in unstructured
  5367     scripts, while still benefitting from proper handling of non-atomic
  5368     statements; NB: major inductive premises need to be put first, all
  5369     the rest of the goal is passed through the induction;
  5370   - 'induct' proper support for mutual induction involving non-atomic
  5371     rule statements (uses the new concept of simultaneous goals, see
  5372     below);
  5373   - append all possible rule selections, but only use the first
  5374     success (no backtracking);
  5375   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5376   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5377   - added 'print_induct_rules' (covered by help item in recent Proof
  5378     General versions);
  5379   - moved induct/cases attributes to Pure, methods to Provers;
  5380   - generic method setup instantiated for FOL and HOL;
  5381 
  5382 * Pure: support multiple simultaneous goal statements, for example
  5383 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5384 meta-level mechanism, this acts as if several individual goals had
  5385 been stated separately; in particular common proof methods need to be
  5386 repeated in order to cover all claims; note that a single elimination
  5387 step is *not* sufficient to establish the two conjunctions, so this
  5388 fails:
  5389 
  5390   assume "A & B" then have A and B ..   (*".." fails*)
  5391 
  5392 better use "obtain" in situations as above; alternative refer to
  5393 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5394 
  5395 * Pure: proper integration with ``locales''; unlike the original
  5396 version by Florian Kammller, Isar locales package high-level proof
  5397 contexts rather than raw logical ones (e.g. we admit to include
  5398 attributes everywhere); operations on locales include merge and
  5399 rename; support for implicit arguments (``structures''); simultaneous
  5400 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5401 some examples;
  5402 
  5403 * Pure: the following commands have been ``localized'', supporting a
  5404 target locale specification "(in name)": 'lemma', 'theorem',
  5405 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5406 stored both within the locale and at the theory level (exported and
  5407 qualified by the locale name);
  5408 
  5409 * Pure: theory goals may now be specified in ``long'' form, with
  5410 ad-hoc contexts consisting of arbitrary locale elements. for example
  5411 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5412 definitions may be given, too); the result is a meta-level rule with
  5413 the context elements being discharged in the obvious way;
  5414 
  5415 * Pure: new proof command 'using' allows to augment currently used
  5416 facts after a goal statement ('using' is syntactically analogous to
  5417 'apply', but acts on the goal's facts only); this allows chained facts
  5418 to be separated into parts given before and after a claim, as in
  5419 ``from a and b have C using d and e <proof>'';
  5420 
  5421 * Pure: renamed "antecedent" case to "rule_context";
  5422 
  5423 * Pure: new 'judgment' command records explicit information about the
  5424 object-logic embedding (used by several tools internally); no longer
  5425 use hard-wired "Trueprop";
  5426 
  5427 * Pure: added 'corollary' command;
  5428 
  5429 * Pure: fixed 'token_translation' command;
  5430 
  5431 * Pure: removed obsolete 'exported' attribute;
  5432 
  5433 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5434 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5435 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5436 
  5437 * Pure: method 'atomize' presents local goal premises as object-level
  5438 statements (atomic meta-level propositions); setup controlled via
  5439 rewrite rules declarations of 'atomize' attribute; example
  5440 application: 'induct' method with proper rule statements in improper
  5441 proof *scripts*;
  5442 
  5443 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5444 now consider the syntactic context of assumptions, giving a better
  5445 chance to get type-inference of the arguments right (this is
  5446 especially important for locales);
  5447 
  5448 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5449 mode;
  5450 
  5451 * Pure/obtain: the formal conclusion "thesis", being marked as
  5452 ``internal'', may no longer be reference directly in the text;
  5453 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5454 situations;
  5455 
  5456 * Pure: generic 'sym' attribute which declares a rule both as pure
  5457 'elim?' and for the 'symmetric' operation;
  5458 
  5459 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5460 text; the fixed correlation with particular command syntax has been
  5461 discontinued;
  5462 
  5463 * Pure: new method 'rules' is particularly well-suited for proof
  5464 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5465 but often produces more compact proof terms with less detours;
  5466 
  5467 * Pure/Provers/classical: simplified integration with pure rule
  5468 attributes and methods; the classical "intro?/elim?/dest?"
  5469 declarations coincide with the pure ones; the "rule" method no longer
  5470 includes classically swapped intros; "intro" and "elim" methods no
  5471 longer pick rules from the context; also got rid of ML declarations
  5472 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5473 INCOMPATIBILITY;
  5474 
  5475 * Provers/classical: attribute 'swapped' produces classical inversions
  5476 of introduction rules;
  5477 
  5478 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5479 rules instead of full simplifier context; 'iff' attribute handles
  5480 conditional rules;
  5481 
  5482 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5483 
  5484 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5485 "(permissive)" option to recover old behavior;
  5486 
  5487 * HOL: 'inductive' no longer features separate (collective) attributes
  5488 for 'intros' (was found too confusing);
  5489 
  5490 * HOL: properly declared induction rules less_induct and
  5491 wf_induct_rule;
  5492 
  5493 
  5494 *** HOL ***
  5495 
  5496 * HOL: moved over to sane numeral syntax; the new policy is as
  5497 follows:
  5498 
  5499   - 0 and 1 are polymorphic constants, which are defined on any
  5500   numeric type (nat, int, real etc.);
  5501 
  5502   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5503   binary representation internally;
  5504 
  5505   - type nat has special constructor Suc, and generally prefers Suc 0
  5506   over 1::nat and Suc (Suc 0) over 2::nat;
  5507 
  5508 This change may cause significant problems of INCOMPATIBILITY; here
  5509 are some hints on converting existing sources:
  5510 
  5511   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5512   entities, so expressions involving "-" (unary or binary minus) need
  5513   to be spaced properly;
  5514 
  5515   - existing occurrences of "1" may need to be constraint "1::nat" or
  5516   even replaced by Suc 0; similar for old "2";
  5517 
  5518   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5519 
  5520   - remove all special provisions on numerals in proofs;
  5521 
  5522 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5523 representation (depends on bin_arith_simps in the default context);
  5524 
  5525 * HOL: symbolic syntax for x^2 (numeral 2);
  5526 
  5527 * HOL: the class of all HOL types is now called "type" rather than
  5528 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5529 in axclass/classes, instance/arities, and (usually rare) occurrences
  5530 in typings (of consts etc.); internally the class is called
  5531 "HOL.type", ML programs should refer to HOLogic.typeS;
  5532 
  5533 * HOL/record package improvements:
  5534   - new derived operations "fields" to build a partial record section,
  5535     "extend" to promote a fixed record to a record scheme, and
  5536     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5537     declared as simp by default;
  5538   - shared operations ("more", "fields", etc.) now need to be always
  5539     qualified) --- potential INCOMPATIBILITY;
  5540   - removed "make_scheme" operations (use "make" with "extend") --
  5541     INCOMPATIBILITY;
  5542   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5543   - provides cases/induct rules for use with corresponding Isar
  5544     methods (for concrete records, record schemes, concrete more
  5545     parts, and schematic more parts -- in that order);
  5546   - internal definitions directly based on a light-weight abstract
  5547     theory of product types over typedef rather than datatype;
  5548 
  5549 * HOL: generic code generator for generating executable ML code from
  5550 specifications; specific support for HOL constructs such as inductive
  5551 datatypes and sets, as well as recursive functions; can be invoked
  5552 via 'generate_code' theory section;
  5553 
  5554 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5555 
  5556 * HOL: consolidated and renamed several theories.  In particular:
  5557         Ord.thy has been absorbed into HOL.thy
  5558         String.thy has been absorbed into List.thy
  5559 
  5560 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5561 (beware of argument permutation!);
  5562 
  5563 * HOL: linorder_less_split superseded by linorder_cases;
  5564 
  5565 * HOL/List: "nodups" renamed to "distinct";
  5566 
  5567 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5568 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5569   - Ex_def has changed, now need to use some_eq_ex
  5570 
  5571 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5572 in this (rare) case use:
  5573 
  5574   delSWrapper "split_all_tac"
  5575   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5576 
  5577 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5578 MAY FAIL;
  5579 
  5580 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5581 Isabelle's type classes, ^ on functions and relations has too general
  5582 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5583 necessary to attach explicit type constraints;
  5584 
  5585 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5586 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5587 renamed accordingly (eg "compI" -> "rel_compI").
  5588 
  5589 * HOL: syntax translations now work properly with numerals and records
  5590 expressions;
  5591 
  5592 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5593 of "lam" -- INCOMPATIBILITY;
  5594 
  5595 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5596 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5597 renamed "Product_Type.unit";
  5598 
  5599 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5600 
  5601 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5602 the "cases" method);
  5603 
  5604 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5605 Florian Kammller);
  5606 
  5607 * HOL/IMP: updated and converted to new-style theory format; several
  5608 parts turned into readable document, with proper Isar proof texts and
  5609 some explanations (by Gerwin Klein);
  5610 
  5611 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5612 
  5613 * HOL-Hyperreal is now a logic image;
  5614 
  5615 
  5616 *** HOLCF ***
  5617 
  5618 * Isar: consts/constdefs supports mixfix syntax for continuous
  5619 operations;
  5620 
  5621 * Isar: domain package adapted to new-style theory format, e.g. see
  5622 HOLCF/ex/Dnat.thy;
  5623 
  5624 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5625 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5626 lift.induct_tac, always use UU instead of Undef;
  5627 
  5628 * HOLCF/IMP: updated and converted to new-style theory;
  5629 
  5630 
  5631 *** ZF ***
  5632 
  5633 * Isar: proper integration of logic-specific tools and packages,
  5634 including theory commands '(co)inductive', '(co)datatype',
  5635 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5636 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5637 
  5638 * theory Main no longer includes AC; for the Axiom of Choice, base
  5639 your theory on Main_ZFC;
  5640 
  5641 * the integer library now covers quotients and remainders, with many
  5642 laws relating division to addition, multiplication, etc.;
  5643 
  5644 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5645 typeless version of the formalism;
  5646 
  5647 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5648 format;
  5649 
  5650 * ZF/Induct: new directory for examples of inductive definitions,
  5651 including theory Multiset for multiset orderings; converted to
  5652 new-style theory format;
  5653 
  5654 * ZF: many new theorems about lists, ordinals, etc.;
  5655 
  5656 
  5657 *** General ***
  5658 
  5659 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5660 variable proof controls level of detail: 0 = no proofs (only oracle
  5661 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5662 also ref manual for further ML interfaces;
  5663 
  5664 * Pure/axclass: removed obsolete ML interface
  5665 goal_subclass/goal_arity;
  5666 
  5667 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5668 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5669 separate tokens, so expressions involving minus need to be spaced
  5670 properly;
  5671 
  5672 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5673 rather than "infixl" or "infixr";
  5674 
  5675 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5676 sort constraint specifications in type inference; e.g. "x::_::foo"
  5677 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5678 type variable);
  5679 
  5680 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5681 control output of nested => (types); the default behavior is
  5682 "type_brackets";
  5683 
  5684 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5685 tokens into AST constants;
  5686 
  5687 * Pure/syntax: prefer later declarations of translations and print
  5688 translation functions; potential INCOMPATIBILITY: need to reverse
  5689 multiple declarations for same syntax element constant;
  5690 
  5691 * Pure/show_hyps reset by default (in accordance to existing Isar
  5692 practice);
  5693 
  5694 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5695 addSafter;
  5696 
  5697 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5698 as well;
  5699 
  5700 * system: tested support for MacOS X; should be able to get Isabelle +
  5701 Proof General to work in a plain Terminal after installing Poly/ML
  5702 (e.g. from the Isabelle distribution area) and GNU bash alone
  5703 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5704 support requires further installations, e.g. from
  5705 http://fink.sourceforge.net/);
  5706 
  5707 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5708 
  5709 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5710 of 40 MB), cf. ML_OPTIONS;
  5711 
  5712 * system: Proof General keywords specification is now part of the
  5713 Isabelle distribution (see etc/isar-keywords.el);
  5714 
  5715 * system: support for persistent Proof General sessions (refrain from
  5716 outdating all loaded theories on startup); user may create writable
  5717 logic images like this: ``isabelle -q HOL Test'';
  5718 
  5719 * system: smart selection of Isabelle process versus Isabelle
  5720 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5721 run both "isabelle" and "Isabelle" even if file names are badly
  5722 damaged (executable inspects the case of the first letter of its own
  5723 name); added separate "isabelle-process" and "isabelle-interface";
  5724 
  5725 * system: refrain from any attempt at filtering input streams; no
  5726 longer support ``8bit'' encoding of old isabelle font, instead proper
  5727 iso-latin characters may now be used; the related isatools
  5728 "symbolinput" and "nonascii" have disappeared as well;
  5729 
  5730 * system: removed old "xterm" interface (the print modes "xterm" and
  5731 "xterm_color" are still available for direct use in a suitable
  5732 terminal);
  5733 
  5734 
  5735 
  5736 New in Isabelle99-2 (February 2001)
  5737 -----------------------------------
  5738 
  5739 *** Overview of INCOMPATIBILITIES ***
  5740 
  5741 * HOL: please note that theories in the Library and elsewhere often use the
  5742 new-style (Isar) format; to refer to their theorems in an ML script you must
  5743 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5744 
  5745 * HOL: inductive package no longer splits induction rule aggressively,
  5746 but only as far as specified by the introductions given; the old
  5747 format may be recovered via ML function complete_split_rule or attribute
  5748 'split_rule (complete)';
  5749 
  5750 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5751 gfp_Tarski to gfp_unfold;
  5752 
  5753 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5754 
  5755 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5756 relation); infix "^^" has been renamed "``"; infix "``" has been
  5757 renamed "`"; "univalent" has been renamed "single_valued";
  5758 
  5759 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5760 operation;
  5761 
  5762 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5763 
  5764 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5765 
  5766 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5767 consequence, it is no longer monotonic wrt. the local goal context
  5768 (which is now passed through the inductive cases);
  5769 
  5770 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5771 \<gg> to \<ggreater>;
  5772 
  5773 
  5774 *** Document preparation ***
  5775 
  5776 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5777 available: are "it" for near math-mode best-style output, "sl" for
  5778 slanted text style, and "tt" for plain type-writer; if no
  5779 \isabellestyle command is given, output is according to slanted
  5780 type-writer);
  5781 
  5782 * support sub/super scripts (for single symbols only), input syntax is
  5783 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5784 
  5785 * some more standard symbols; see Appendix A of the system manual for
  5786 the complete list of symbols defined in isabellesym.sty;
  5787 
  5788 * improved isabelle style files; more abstract symbol implementation
  5789 (should now use \isamath{...} and \isatext{...} in custom symbol
  5790 definitions);
  5791 
  5792 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5793 state; Note that presentation of goal states does not conform to
  5794 actual human-readable proof documents.  Please do not include goal
  5795 states into document output unless you really know what you are doing!
  5796 
  5797 * proper indentation of antiquoted output with proportional LaTeX
  5798 fonts;
  5799 
  5800 * no_document ML operator temporarily disables LaTeX document
  5801 generation;
  5802 
  5803 * isatool unsymbolize tunes sources for plain ASCII communication;
  5804 
  5805 
  5806 *** Isar ***
  5807 
  5808 * Pure: Isar now suffers initial goal statements to contain unbound
  5809 schematic variables (this does not conform to actual readable proof
  5810 documents, due to unpredictable outcome and non-compositional proof
  5811 checking); users who know what they are doing may use schematic goals
  5812 for Prolog-style synthesis of proven results;
  5813 
  5814 * Pure: assumption method (an implicit finishing) now handles actual
  5815 rules as well;
  5816 
  5817 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5818 initial goal, declare "that" only as Pure intro (only for single
  5819 steps); the "that" rule assumption may now be involved in implicit
  5820 finishing, thus ".." becomes a feasible for trivial obtains;
  5821 
  5822 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5823 instance proofs may be performed by "..";
  5824 
  5825 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5826 statements as well;
  5827 
  5828 * Pure: more robust selection of calculational rules;
  5829 
  5830 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5831 rule (as well as the assumption rule);
  5832 
  5833 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5834 lemmas, using the graph browser tool;
  5835 
  5836 * Pure: predict failure of "show" in interactive mode;
  5837 
  5838 * Pure: 'thms_containing' now takes actual terms as arguments;
  5839 
  5840 * HOL: improved method 'induct' --- now handles non-atomic goals
  5841 (potential INCOMPATIBILITY); tuned error handling;
  5842 
  5843 * HOL: cases and induct rules now provide explicit hints about the
  5844 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5845 any remaining facts are inserted into the goal verbatim;
  5846 
  5847 * HOL: local contexts (aka cases) may now contain term bindings as
  5848 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5849 the result to be shown in each case;
  5850 
  5851 * HOL: added 'recdef_tc' command;
  5852 
  5853 * isatool convert assists in eliminating legacy ML scripts;
  5854 
  5855 
  5856 *** HOL ***
  5857 
  5858 * HOL/Library: a collection of generic theories to be used together
  5859 with main HOL; the theory loader path already includes this directory
  5860 by default; the following existing theories have been moved here:
  5861 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5862 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5863 
  5864 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5865 modelling and verification task performed in Isabelle/HOL +
  5866 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5867 
  5868 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5869 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5870 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5871 'domain', this makes the theory consistent with mathematical
  5872 literature;
  5873 
  5874 * HOL basics: added overloaded operations "inverse" and "divide"
  5875 (infix "/"), syntax for generic "abs" operation, generic summation
  5876 operator \<Sum>;
  5877 
  5878 * HOL/typedef: simplified package, provide more useful rules (see also
  5879 HOL/subset.thy);
  5880 
  5881 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5882 now expressed as a proper nested rule (old-style tactic scripts may
  5883 require atomize_strip_tac to cope with non-atomic premises);
  5884 
  5885 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5886 to "split_conv" (old name still available for compatibility);
  5887 
  5888 * HOL: improved concrete syntax for strings (e.g. allows translation
  5889 rules with string literals);
  5890 
  5891 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5892  and Fleuriot's mechanization of analysis, including the transcendental
  5893  functions for the reals;
  5894 
  5895 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5896 
  5897 
  5898 *** CTT ***
  5899 
  5900 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5901 "lam" is displayed as TWO lambda-symbols
  5902 
  5903 * CTT: theory Main now available, containing everything (that is, Bool
  5904 and Arith);
  5905 
  5906 
  5907 *** General ***
  5908 
  5909 * Pure: the Simplifier has been implemented properly as a derived rule
  5910 outside of the actual kernel (at last!); the overall performance
  5911 penalty in practical applications is about 50%, while reliability of
  5912 the Isabelle inference kernel has been greatly improved;
  5913 
  5914 * print modes "brackets" and "no_brackets" control output of nested =>
  5915 (types) and ==> (props); the default behaviour is "brackets";
  5916 
  5917 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5918 as assumptions as well;
  5919 
  5920 * system: support Poly/ML 4.0;
  5921 
  5922 * system: isatool install handles KDE version 1 or 2;
  5923 
  5924 
  5925 
  5926 New in Isabelle99-1 (October 2000)
  5927 ----------------------------------
  5928 
  5929 *** Overview of INCOMPATIBILITIES ***
  5930 
  5931 * HOL: simplification of natural numbers is much changed; to partly
  5932 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5933 issue the following ML commands:
  5934 
  5935   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5936   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5937 
  5938 * HOL: simplification no longer dives into case-expressions; this is
  5939 controlled by "t.weak_case_cong" for each datatype t;
  5940 
  5941 * HOL: nat_less_induct renamed to less_induct;
  5942 
  5943 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5944 fixsome to patch .thy and .ML sources automatically;
  5945 
  5946   select_equality  -> some_equality
  5947   select_eq_Ex     -> some_eq_ex
  5948   selectI2EX       -> someI2_ex
  5949   selectI2         -> someI2
  5950   selectI          -> someI
  5951   select1_equality -> some1_equality
  5952   Eps_sym_eq       -> some_sym_eq_trivial
  5953   Eps_eq           -> some_eq_trivial
  5954 
  5955 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5956 
  5957 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5958 instead);
  5959 
  5960 * HOL: the recursion equations generated by 'recdef' are now called
  5961 f.simps instead of f.rules;
  5962 
  5963 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5964 
  5965 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5966 sometimes be needed;
  5967 
  5968 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5969 
  5970 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5971 
  5972 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5973 product is now "<*>" instead of "Times"; the lexicographic product is
  5974 now "<*lex*>" instead of "**";
  5975 
  5976 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5977 of main HOL, but was unused); better use HOL's datatype package;
  5978 
  5979 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5980 the old syntax may be recovered as follows:
  5981 
  5982   syntax (symbols)
  5983     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5984       (infixl "\\<oplus>" 100)
  5985 
  5986 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5987 
  5988 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5989 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5990 internally;
  5991 
  5992 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5993 changed from A/r to A//r;
  5994 
  5995 * ZF: new treatment of arithmetic (nat & int) may break some old
  5996 proofs;
  5997 
  5998 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5999 rulify -> rule_format, elimify -> elim_format, ...);
  6000 
  6001 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6002 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6003 should have to change intro!! to intro? only); replaced "delrule" by
  6004 "rule del";
  6005 
  6006 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6007 
  6008 * Provers: strengthened force_tac by using new first_best_tac;
  6009 
  6010 * LaTeX document preparation: several changes of isabelle.sty (see
  6011 lib/texinputs);
  6012 
  6013 
  6014 *** Document preparation ***
  6015 
  6016 * formal comments (text blocks etc.) in new-style theories may now
  6017 contain antiquotations of thm/prop/term/typ/text to be presented
  6018 according to latex print mode; concrete syntax is like this:
  6019 @{term[show_types] "f(x) = a + x"};
  6020 
  6021 * isatool mkdir provides easy setup of Isabelle session directories,
  6022 including proper document sources;
  6023 
  6024 * generated LaTeX sources are now deleted after successful run
  6025 (isatool document -c); may retain a copy somewhere else via -D option
  6026 of isatool usedir;
  6027 
  6028 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6029 style files, achieving self-contained LaTeX sources and simplifying
  6030 LaTeX debugging;
  6031 
  6032 * old-style theories now produce (crude) LaTeX output as well;
  6033 
  6034 * browser info session directories are now self-contained (may be put
  6035 on WWW server seperately); improved graphs of nested sessions; removed
  6036 graph for 'all sessions';
  6037 
  6038 * several improvements in isabelle style files; \isabellestyle{it}
  6039 produces fake math mode output; \isamarkupheader is now \section by
  6040 default; see lib/texinputs/isabelle.sty etc.;
  6041 
  6042 
  6043 *** Isar ***
  6044 
  6045 * Isar/Pure: local results and corresponding term bindings are now
  6046 subject to Hindley-Milner polymorphism (similar to ML); this
  6047 accommodates incremental type-inference very nicely;
  6048 
  6049 * Isar/Pure: new derived language element 'obtain' supports
  6050 generalized existence reasoning;
  6051 
  6052 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6053 support accumulation of results, without applying any rules yet;
  6054 useful to collect intermediate results without explicit name
  6055 references, and for use with transitivity rules with more than 2
  6056 premises;
  6057 
  6058 * Isar/Pure: scalable support for case-analysis type proofs: new
  6059 'case' language element refers to local contexts symbolically, as
  6060 produced by certain proof methods; internally, case names are attached
  6061 to theorems as "tags";
  6062 
  6063 * Isar/Pure: theory command 'hide' removes declarations from
  6064 class/type/const name spaces;
  6065 
  6066 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6067 indicate potential overloading;
  6068 
  6069 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6070 
  6071 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6072 "{a,b,c}" instead of {a,b,c};
  6073 
  6074 * Isar/Pure now provides its own version of intro/elim/dest
  6075 attributes; useful for building new logics, but beware of confusion
  6076 with the version in Provers/classical;
  6077 
  6078 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6079 case name 'antecedent';
  6080 
  6081 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6082 to the current context is now done automatically);
  6083 
  6084 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6085 for definining proof methods in ML;
  6086 
  6087 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6088 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6089 most cases, one should have to change intro!! to intro? only);
  6090 replaced "delrule" by "rule del";
  6091 
  6092 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6093 'symmetric' attribute (the latter supercedes [RS sym]);
  6094 
  6095 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6096 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6097 well (including splits);
  6098 
  6099 * Isar/Provers: Simplifier and Classical methods now support all kind
  6100 of modifiers used in the past, including 'cong', 'iff', etc.
  6101 
  6102 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6103 of Simplifier and Classical reasoner);
  6104 
  6105 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6106 now support named cases; major packages (inductive, datatype, primrec,
  6107 recdef) support case names and properly name parameters;
  6108 
  6109 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6110 monotonicity conditions are extracted to be proven at end of
  6111 calculations;
  6112 
  6113 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6114 method anyway;
  6115 
  6116 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6117 split_if split_if_asm; datatype package provides theorems foo.splits =
  6118 foo.split foo.split_asm for each datatype;
  6119 
  6120 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6121 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6122 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6123 use "(cases (simplified))" method in proper proof texts);
  6124 
  6125 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6126 
  6127 * Isar: names of theorems etc. may be natural numbers as well;
  6128 
  6129 * Isar: 'pr' command: optional arguments for goals_limit and
  6130 ProofContext.prems_limit; no longer prints theory contexts, but only
  6131 proof states;
  6132 
  6133 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6134 additional print modes to be specified; e.g. "pr(latex)" will print
  6135 proof state according to the Isabelle LaTeX style;
  6136 
  6137 * Isar: improved support for emulating tactic scripts, including proof
  6138 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6139 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6140 (for HOL datatypes);
  6141 
  6142 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6143 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6144 'proof method scripts' have to be in depth-first order;
  6145 
  6146 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6147 
  6148 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6149 should instead use individual commands for printing items
  6150 (print_commands, print_methods etc.);
  6151 
  6152 * Isar: added 'nothing' --- the empty list of theorems;
  6153 
  6154 
  6155 *** HOL ***
  6156 
  6157 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6158 corresponding virtual machine and a specification of its bytecode
  6159 verifier and a lightweight bytecode verifier, including proofs of
  6160 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6161 Cornelia Pusch (see also the homepage of project Bali at
  6162 http://isabelle.in.tum.de/Bali/);
  6163 
  6164 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6165 Clemens Ballarin;
  6166 
  6167 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6168 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6169 Rasmussen;
  6170 
  6171 * HOL/Lattice: fundamental concepts of lattice theory and order
  6172 structures, including duals, properties of bounds versus algebraic
  6173 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6174 Theorem for complete lattices etc.; may also serve as a demonstration
  6175 for abstract algebraic reasoning using axiomatic type classes, and
  6176 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6177 
  6178 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6179 von Oheimb;
  6180 
  6181 * HOL/IMPP: extension of IMP with local variables and mutually
  6182 recursive procedures, by David von Oheimb;
  6183 
  6184 * HOL/Lambda: converted into new-style theory and document;
  6185 
  6186 * HOL/ex/Multiquote: example of multiple nested quotations and
  6187 anti-quotations -- basically a generalized version of de-Bruijn
  6188 representation; very useful in avoiding lifting of operations;
  6189 
  6190 * HOL/record: added general record equality rule to simpset; fixed
  6191 select-update simplification procedure to handle extended records as
  6192 well; admit "r" as field name;
  6193 
  6194 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6195 other numeric types and also as the identity of groups, rings, etc.;
  6196 
  6197 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6198 Types nat and int belong to this axclass;
  6199 
  6200 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6201    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6202    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6203   two terms #m*u and #n*u are replaced by #(m+n)*u
  6204     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6205   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6206     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6207 
  6208 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6209 powerful prover for predicate logic but knows nothing of clasets; see
  6210 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6211 
  6212 * HOL: new version of "case_tac" subsumes both boolean case split and
  6213 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6214 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6215 
  6216 * HOL: simplification no longer dives into case-expressions: only the
  6217 selector expression is simplified, but not the remaining arms; to
  6218 enable full simplification of case-expressions for datatype t, you may
  6219 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6220 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6221 
  6222 * HOL/recdef: the recursion equations generated by 'recdef' for
  6223 function 'f' are now called f.simps instead of f.rules; if all
  6224 termination conditions are proved automatically, these simplification
  6225 rules are added to the simpset, as in primrec; rules may be named
  6226 individually as well, resulting in a separate list of theorems for
  6227 each equation;
  6228 
  6229 * HOL/While is a new theory that provides a while-combinator. It
  6230 permits the definition of tail-recursive functions without the
  6231 provision of a termination measure. The latter is necessary once the
  6232 invariant proof rule for while is applied.
  6233