NEWS
author wenzelm
Mon Sep 06 21:33:19 2010 +0200 (2010-09-06 ago)
changeset 39163 4d701c0388c3
parent 39154 14b16b380ca1
child 39164 e7e12555e763
permissions -rw-r--r--
more explicit indication of Config.raw options, which are only needed for bootstrapping Pure;
     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 pretty printing etc. 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 (Config.T)                 Isar (attribute)
    32 
    33   eta_contract                  eta_contract
    34   show_brackets                 show_brackets
    35   show_sorts                    show_sorts
    36   show_types                    show_types
    37   show_question_marks           show_question_marks
    38   show_consts                   show_consts
    39 
    40   Syntax.ambiguity_level        syntax_ambiguity_level
    41 
    42   Goal_Display.goals_limit      goals_limit
    43   Goal_Display.show_main_goal   show_main_goal
    44 
    45   Thy_Output.display            thy_output_display
    46   Thy_Output.quotes             thy_output_quotes
    47   Thy_Output.indent             thy_output_indent
    48   Thy_Output.source             thy_output_source
    49   Thy_Output.break              thy_output_break
    50 
    51 Note that corresponding "..._default" references in ML may be only
    52 changed globally at the ROOT session setup, but *not* within a theory.
    53 
    54 
    55 *** Pure ***
    56 
    57 * Interpretation command 'interpret' accepts a list of equations like
    58 'interpretation' does.
    59 
    60 * Diagnostic command 'print_interps' prints interpretations in proofs
    61 in addition to interpretations in theories.
    62 
    63 * Discontinued obsolete 'global' and 'local' commands to manipulate
    64 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    65 Sign.root_path and Sign.local_path may be applied directly where this
    66 feature is still required for historical reasons.
    67 
    68 
    69 *** HOL ***
    70 
    71 * Renamed class eq and constant eq (for code generation) to class equal
    72 and constant equal, plus renaming of related facts and various tuning.
    73 INCOMPATIBILITY.
    74 
    75 * Scala (2.8 or higher) has been added to the target languages of
    76 the code generator.
    77 
    78 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    79 
    80 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    81 canonical names for instance definitions for functions; various improvements.
    82 INCOMPATIBILITY.
    83 
    84 * Records: logical foundation type for records do not carry a '_type' suffix
    85 any longer.  INCOMPATIBILITY.
    86 
    87 * Code generation for records: more idiomatic representation of record types.
    88 Warning: records are not covered by ancient SML code generation any longer.
    89 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    90 helps to succeed then:
    91 
    92   record 'a foo = ...
    93   ...
    94   rep_datatype foo_ext ...
    95 
    96 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    97 INCOMPATIBILITY.
    98 
    99 * Quickcheck in locales considers interpretations of that locale for
   100 counter example search.
   101 
   102 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
   103 in Library/State_Monad has been changed to avoid ambiguities.
   104 INCOMPATIBILITY.
   105 
   106 * Code generator: export_code without explicit file declaration prints
   107 to standard output.  INCOMPATIBILITY.
   108 
   109 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   110 respectively.  INCOMPATIBILITY.
   111 
   112 * Constant "split" has been merged with constant "prod_case";  names
   113 of ML functions, facts etc. involving split have been retained so far,
   114 though.  INCOMPATIBILITY.
   115 
   116 * Dropped old infix syntax "mem" for List.member;  use "in set"
   117 instead.  INCOMPATIBILITY.
   118 
   119 * Refactoring of code-generation specific operations in List.thy
   120 
   121   constants
   122     null ~> List.null
   123 
   124   facts
   125     mem_iff ~> member_def
   126     null_empty ~> null_def
   127 
   128 INCOMPATIBILITY.  Note that these were not suppossed to be used
   129 regularly unless for striking reasons;  their main purpose was code
   130 generation.
   131 
   132 * Some previously unqualified names have been qualified:
   133 
   134   types
   135     bool ~> HOL.bool
   136     nat ~> Nat.nat
   137 
   138   constants
   139     Trueprop ~> HOL.Trueprop
   140     True ~> HOL.True
   141     False ~> HOL.False
   142     op & ~> HOL.conj
   143     op | ~> HOL.disj
   144     op --> ~> HOL.implies
   145     op = ~> HOL.eq
   146     Not ~> HOL.Not
   147     The ~> HOL.The
   148     All ~> HOL.All
   149     Ex ~> HOL.Ex
   150     Ex1 ~> HOL.Ex1
   151     Let ~> HOL.Let
   152     If ~> HOL.If
   153     Ball ~> Set.Ball
   154     Bex ~> Set.Bex
   155     Suc ~> Nat.Suc
   156     Pair ~> Product_Type.Pair
   157     fst ~> Product_Type.fst
   158     snd ~> Product_Type.snd
   159     curry ~> Product_Type.curry
   160     op : ~> Set.member
   161     Collect ~> Set.Collect
   162 
   163 INCOMPATIBILITY.
   164 
   165 * Removed simplifier congruence rule of "prod_case", as has for long
   166 been the case with "split".  INCOMPATIBILITY.
   167 
   168 * Datatype package: theorems generated for executable equality
   169 (class eq) carry proper names and are treated as default code
   170 equations.
   171 
   172 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   173 INCOMPATIBILITY.
   174 
   175 * List.thy: use various operations from the Haskell prelude when
   176 generating Haskell code.
   177 
   178 * code_simp.ML and method code_simp: simplification with rules determined
   179 by code generator.
   180 
   181 * code generator: do not print function definitions for case
   182 combinators any longer.
   183 
   184 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   185 theorems are now stated in terms of euclidean spaces instead of finite
   186 cartesian products.
   187 
   188   types
   189     real ^ 'n ~>  'a::real_vector
   190               ~>  'a::euclidean_space
   191               ~>  'a::ordered_euclidean_space
   192         (depends on your needs)
   193 
   194   constants
   195      _ $ _        ~> _ $$ _
   196      \<chi> x. _  ~> \<chi>\<chi> x. _
   197      CARD('n)     ~> DIM('a)
   198 
   199 Also note that the indices are now natural numbers and not from some finite
   200 type. Finite cartesian products of euclidean spaces, products of euclidean
   201 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   202 
   203 INCOMPATIBILITY.
   204 
   205 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   206 as value for measures. Introduces Lebesgue Measure based on the integral in
   207 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   208 spaces.
   209 
   210  INCOMPATIBILITY.
   211 
   212 * Inductive package: offers new command "inductive_simps" to automatically
   213 derive instantiated and simplified equations for inductive predicates,
   214 similar to inductive_cases.
   215 
   216 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". surj_on is a
   217 generalization of surj, and "surj f" is now a abbreviation of "surj_on f UNIV".
   218 The theorems bij_def and surj_def are unchanged.
   219 
   220 *** FOL ***
   221 
   222 * All constant names are now qualified.  INCOMPATIBILITY.
   223 
   224 
   225 *** ZF ***
   226 
   227 * All constant names are now qualified.  INCOMPATIBILITY.
   228 
   229 
   230 *** ML ***
   231 
   232 * Configuration option show_question_marks only affects regular pretty
   233 printing of types and terms, not raw Term.string_of_vname.
   234 
   235 * ML structure Unsynchronized never opened, not even in Isar
   236 interaction mode as before.  Old Unsynchronized.set etc. have been
   237 discontinued -- use plain := instead.  This should be *rare* anyway,
   238 since modern tools always work via official context data, notably
   239 configuration options.
   240 
   241 * ML antiquotations @{theory} and @{theory_ref} refer to named
   242 theories from the ancestry of the current context, not any accidental
   243 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   244 change in semantics.
   245 
   246 
   247 *** System ***
   248 
   249 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   250 
   251 
   252 
   253 New in Isabelle2009-2 (June 2010)
   254 ---------------------------------
   255 
   256 *** General ***
   257 
   258 * Authentic syntax for *all* logical entities (type classes, type
   259 constructors, term constants): provides simple and robust
   260 correspondence between formal entities and concrete syntax.  Within
   261 the parse tree / AST representations, "constants" are decorated by
   262 their category (class, type, const) and spelled out explicitly with
   263 their full internal name.
   264 
   265 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   266 and translations (translation rules and translation functions in ML).
   267 Some hints on upgrading:
   268 
   269   - Many existing uses of 'syntax' and 'translations' can be replaced
   270     by more modern 'type_notation', 'notation' and 'abbreviation',
   271     which are independent of this issue.
   272 
   273   - 'translations' require markup within the AST; the term syntax
   274     provides the following special forms:
   275 
   276       CONST c   -- produces syntax version of constant c from context
   277       XCONST c  -- literally c, checked as constant from context
   278       c         -- literally c, if declared by 'syntax'
   279 
   280     Plain identifiers are treated as AST variables -- occasionally the
   281     system indicates accidental variables via the error "rhs contains
   282     extra variables".
   283 
   284     Type classes and type constructors are marked according to their
   285     concrete syntax.  Some old translations rules need to be written
   286     for the "type" category, using type constructor application
   287     instead of pseudo-term application of the default category
   288     "logic".
   289 
   290   - 'parse_translation' etc. in ML may use the following
   291     antiquotations:
   292 
   293       @{class_syntax c}   -- type class c within parse tree / AST
   294       @{term_syntax c}    -- type constructor c within parse tree / AST
   295       @{const_syntax c}   -- ML version of "CONST c" above
   296       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   297 
   298   - Literal types within 'typed_print_translations', i.e. those *not*
   299     represented as pseudo-terms are represented verbatim.  Use @{class
   300     c} or @{type_name c} here instead of the above syntax
   301     antiquotations.
   302 
   303 Note that old non-authentic syntax was based on unqualified base
   304 names, so all of the above "constant" names would coincide.  Recall
   305 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   306 diagnose syntax problems.
   307 
   308 * Type constructors admit general mixfix syntax, not just infix.
   309 
   310 * Concrete syntax may be attached to local entities without a proof
   311 body, too.  This works via regular mixfix annotations for 'fix',
   312 'def', 'obtain' etc. or via the explicit 'write' command, which is
   313 similar to the 'notation' command in theory specifications.
   314 
   315 * Discontinued unnamed infix syntax (legacy feature for many years) --
   316 need to specify constant name and syntax separately.  Internal ML
   317 datatype constructors have been renamed from InfixName to Infix etc.
   318 Minor INCOMPATIBILITY.
   319 
   320 * Schematic theorem statements need to be explicitly markup as such,
   321 via commands 'schematic_lemma', 'schematic_theorem',
   322 'schematic_corollary'.  Thus the relevance of the proof is made
   323 syntactically clear, which impacts performance in a parallel or
   324 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   325 
   326 * Use of cumulative prems via "!" in some proof methods has been
   327 discontinued (old legacy feature).
   328 
   329 * References 'trace_simp' and 'debug_simp' have been replaced by
   330 configuration options stored in the context. Enabling tracing (the
   331 case of debugging is similar) in proofs works via
   332 
   333   using [[trace_simp = true]]
   334 
   335 Tracing is then active for all invocations of the simplifier in
   336 subsequent goal refinement steps. Tracing may also still be enabled or
   337 disabled via the ProofGeneral settings menu.
   338 
   339 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   340 'hide_fact' replace the former 'hide' KIND command.  Minor
   341 INCOMPATIBILITY.
   342 
   343 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   344 more efficient than combinations with -q1 or -q2.
   345 
   346 
   347 *** Pure ***
   348 
   349 * Proofterms record type-class reasoning explicitly, using the
   350 "unconstrain" operation internally.  This eliminates all sort
   351 constraints from a theorem and proof, introducing explicit
   352 OFCLASS-premises.  On the proof term level, this operation is
   353 automatically applied at theorem boundaries, such that closed proofs
   354 are always free of sort constraints.  INCOMPATIBILITY for tools that
   355 inspect proof terms.
   356 
   357 * Local theory specifications may depend on extra type variables that
   358 are not present in the result type -- arguments TYPE('a) :: 'a itself
   359 are added internally.  For example:
   360 
   361   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   362 
   363 * Predicates of locales introduced by classes carry a mandatory
   364 "class" prefix.  INCOMPATIBILITY.
   365 
   366 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   367 
   368 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   369 'class' instead.
   370 
   371 * Command 'code_reflect' allows to incorporate generated ML code into
   372 runtime environment; replaces immature code_datatype antiquotation.
   373 INCOMPATIBILITY.
   374 
   375 * Code generator: simple concept for abstract datatypes obeying
   376 invariants.
   377 
   378 * Code generator: details of internal data cache have no impact on the
   379 user space functionality any longer.
   380 
   381 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   382 subgoals.  This is more appropriate for interpretations with 'where'.
   383 INCOMPATIBILITY.
   384 
   385 * Command 'example_proof' opens an empty proof body.  This allows to
   386 experiment with Isar, without producing any persistent result.
   387 
   388 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   389 within a local theory context, with explicit checking of the
   390 constructors involved (in contrast to the raw 'syntax' versions).
   391 
   392 * Commands 'types' and 'typedecl' now work within a local theory
   393 context -- without introducing dependencies on parameters or
   394 assumptions, which is not possible in Isabelle/Pure.
   395 
   396 * Command 'defaultsort' has been renamed to 'default_sort', it works
   397 within a local theory context.  Minor INCOMPATIBILITY.
   398 
   399 
   400 *** HOL ***
   401 
   402 * Command 'typedef' now works within a local theory context -- without
   403 introducing dependencies on parameters or assumptions, which is not
   404 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   405 contain multiple interpretations of local typedefs (with different
   406 non-emptiness proofs), even in a global theory context.
   407 
   408 * New package for quotient types.  Commands 'quotient_type' and
   409 'quotient_definition' may be used for defining types and constants by
   410 quotient constructions.  An example is the type of integers created by
   411 quotienting pairs of natural numbers:
   412 
   413   fun
   414     intrel :: "(nat * nat) => (nat * nat) => bool"
   415   where
   416     "intrel (x, y) (u, v) = (x + v = u + y)"
   417 
   418   quotient_type int = "nat * nat" / intrel
   419     by (auto simp add: equivp_def expand_fun_eq)
   420 
   421   quotient_definition
   422     "0::int" is "(0::nat, 0::nat)"
   423 
   424 The method "lifting" can be used to lift of theorems from the
   425 underlying "raw" type to the quotient type.  The example
   426 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   427 construction and provides a reasoning infrastructure for finite sets.
   428 
   429 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   430 clash with new theory Quotient in Main HOL.
   431 
   432 * Moved the SMT binding into the main HOL session, eliminating
   433 separate HOL-SMT session.
   434 
   435 * List membership infix mem operation is only an input abbreviation.
   436 INCOMPATIBILITY.
   437 
   438 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   439 for future developements; former Library/Word.thy is still present in
   440 the AFP entry RSAPPS.
   441 
   442 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   443 longer shadowed.  INCOMPATIBILITY.
   444 
   445 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   446 INCOMPATIBILITY.
   447 
   448 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   449 INCOMPATIBILITY.
   450 
   451 * Dropped normalizing_semiring etc; use the facts in semiring classes
   452 instead.  INCOMPATIBILITY.
   453 
   454 * Dropped several real-specific versions of lemmas about floor and
   455 ceiling; use the generic lemmas from theory "Archimedean_Field"
   456 instead.  INCOMPATIBILITY.
   457 
   458   floor_number_of_eq         ~> floor_number_of
   459   le_floor_eq_number_of      ~> number_of_le_floor
   460   le_floor_eq_zero           ~> zero_le_floor
   461   le_floor_eq_one            ~> one_le_floor
   462   floor_less_eq_number_of    ~> floor_less_number_of
   463   floor_less_eq_zero         ~> floor_less_zero
   464   floor_less_eq_one          ~> floor_less_one
   465   less_floor_eq_number_of    ~> number_of_less_floor
   466   less_floor_eq_zero         ~> zero_less_floor
   467   less_floor_eq_one          ~> one_less_floor
   468   floor_le_eq_number_of      ~> floor_le_number_of
   469   floor_le_eq_zero           ~> floor_le_zero
   470   floor_le_eq_one            ~> floor_le_one
   471   floor_subtract_number_of   ~> floor_diff_number_of
   472   floor_subtract_one         ~> floor_diff_one
   473   ceiling_number_of_eq       ~> ceiling_number_of
   474   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   475   ceiling_le_zero_eq         ~> ceiling_le_zero
   476   ceiling_le_eq_one          ~> ceiling_le_one
   477   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   478   less_ceiling_eq_zero       ~> zero_less_ceiling
   479   less_ceiling_eq_one        ~> one_less_ceiling
   480   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   481   ceiling_less_eq_zero       ~> ceiling_less_zero
   482   ceiling_less_eq_one        ~> ceiling_less_one
   483   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   484   le_ceiling_eq_zero         ~> zero_le_ceiling
   485   le_ceiling_eq_one          ~> one_le_ceiling
   486   ceiling_subtract_number_of ~> ceiling_diff_number_of
   487   ceiling_subtract_one       ~> ceiling_diff_one
   488 
   489 * Theory "Finite_Set": various folding_XXX locales facilitate the
   490 application of the various fold combinators on finite sets.
   491 
   492 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   493 provides abstract red-black tree type which is backed by "RBT_Impl" as
   494 implementation.  INCOMPATIBILTY.
   495 
   496 * Theory Library/Coinductive_List has been removed -- superseded by
   497 AFP/thys/Coinductive.
   498 
   499 * Theory PReal, including the type "preal" and related operations, has
   500 been removed.  INCOMPATIBILITY.
   501 
   502 * Real: new development using Cauchy Sequences.
   503 
   504 * Split off theory "Big_Operators" containing setsum, setprod,
   505 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   506 
   507 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   508 "Int" etc.  INCOMPATIBILITY.
   509 
   510 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   511 
   512 * New set of rules "ac_simps" provides combined assoc / commute
   513 rewrites for all interpretations of the appropriate generic locales.
   514 
   515 * Renamed theory "OrderedGroup" to "Groups" and split theory
   516 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   517 appropriate and more consistent names suitable for name prefixes
   518 within the HOL theories.  INCOMPATIBILITY.
   519 
   520 * Some generic constants have been put to appropriate theories:
   521   - less_eq, less: Orderings
   522   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   523   - inverse, divide: Rings
   524 INCOMPATIBILITY.
   525 
   526 * More consistent naming of type classes involving orderings (and
   527 lattices):
   528 
   529     lower_semilattice                   ~> semilattice_inf
   530     upper_semilattice                   ~> semilattice_sup
   531 
   532     dense_linear_order                  ~> dense_linorder
   533 
   534     pordered_ab_group_add               ~> ordered_ab_group_add
   535     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   536     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   537     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   538     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   539     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   540     pordered_cancel_semiring            ~> ordered_cancel_semiring
   541     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   542     pordered_comm_ring                  ~> ordered_comm_ring
   543     pordered_comm_semiring              ~> ordered_comm_semiring
   544     pordered_ring                       ~> ordered_ring
   545     pordered_ring_abs                   ~> ordered_ring_abs
   546     pordered_semiring                   ~> ordered_semiring
   547 
   548     ordered_ab_group_add                ~> linordered_ab_group_add
   549     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   550     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   551     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   552     ordered_field                       ~> linordered_field
   553     ordered_field_no_lb                 ~> linordered_field_no_lb
   554     ordered_field_no_ub                 ~> linordered_field_no_ub
   555     ordered_field_dense_linear_order    ~> dense_linordered_field
   556     ordered_idom                        ~> linordered_idom
   557     ordered_ring                        ~> linordered_ring
   558     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   559     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   560     ordered_ring_strict                 ~> linordered_ring_strict
   561     ordered_semidom                     ~> linordered_semidom
   562     ordered_semiring                    ~> linordered_semiring
   563     ordered_semiring_1                  ~> linordered_semiring_1
   564     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   565     ordered_semiring_strict             ~> linordered_semiring_strict
   566 
   567   The following slightly odd type classes have been moved to a
   568   separate theory Library/Lattice_Algebras:
   569 
   570     lordered_ab_group_add               ~> lattice_ab_group_add
   571     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   572     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   573     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   574     lordered_ring                       ~> lattice_ring
   575 
   576 INCOMPATIBILITY.
   577 
   578 * Refined field classes:
   579   - classes division_ring_inverse_zero, field_inverse_zero,
   580     linordered_field_inverse_zero include rule inverse 0 = 0 --
   581     subsumes former division_by_zero class;
   582   - numerous lemmas have been ported from field to division_ring.
   583 INCOMPATIBILITY.
   584 
   585 * Refined algebra theorem collections:
   586   - dropped theorem group group_simps, use algebra_simps instead;
   587   - dropped theorem group ring_simps, use field_simps instead;
   588   - proper theorem collection field_simps subsumes former theorem
   589     groups field_eq_simps and field_simps;
   590   - dropped lemma eq_minus_self_iff which is a duplicate for
   591     equal_neg_zero.
   592 INCOMPATIBILITY.
   593 
   594 * Theory Finite_Set and List: some lemmas have been generalized from
   595 sets to lattices:
   596 
   597   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   598   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   599   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   600   union_Union_fold_union        ~> sup_Sup_fold_sup
   601   Inter_fold_inter              ~> Inf_fold_inf
   602   Union_fold_union              ~> Sup_fold_sup
   603   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   604   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   605   INTER_fold_inter              ~> INFI_fold_inf
   606   UNION_fold_union              ~> SUPR_fold_sup
   607 
   608 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   609 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   610 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   611 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   612 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   613 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   614 
   615 * Reorganized theory Multiset: swapped notation of pointwise and
   616 multiset order:
   617 
   618   - pointwise ordering is instance of class order with standard syntax
   619     <= and <;
   620   - multiset ordering has syntax <=# and <#; partial order properties
   621     are provided by means of interpretation with prefix
   622     multiset_order;
   623   - less duplication, less historical organization of sections,
   624     conversion from associations lists to multisets, rudimentary code
   625     generation;
   626   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   627     if needed.
   628 
   629 Renamed:
   630 
   631   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   632   multi_count_ext  ~>  multiset_ext
   633   diff_union_inverse2  ~>  diff_union_cancelR
   634 
   635 INCOMPATIBILITY.
   636 
   637 * Theory Permutation: replaced local "remove" by List.remove1.
   638 
   639 * Code generation: ML and OCaml code is decorated with signatures.
   640 
   641 * Theory List: added transpose.
   642 
   643 * Library/Nat_Bijection.thy is a collection of bijective functions
   644 between nat and other types, which supersedes the older libraries
   645 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   646 
   647   Constants:
   648   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   649   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   650   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   651   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   652   Countable.pair_encode           ~> prod_encode
   653   NatIso.prod2nat                 ~> prod_encode
   654   NatIso.nat2prod                 ~> prod_decode
   655   NatIso.sum2nat                  ~> sum_encode
   656   NatIso.nat2sum                  ~> sum_decode
   657   NatIso.list2nat                 ~> list_encode
   658   NatIso.nat2list                 ~> list_decode
   659   NatIso.set2nat                  ~> set_encode
   660   NatIso.nat2set                  ~> set_decode
   661 
   662   Lemmas:
   663   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   664   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   665   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   666   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   667   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   668   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   669   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   670   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   671   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   672   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   673   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   674   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   675   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   676 
   677 * Sledgehammer:
   678   - Renamed ATP commands:
   679     atp_info     ~> sledgehammer running_atps
   680     atp_kill     ~> sledgehammer kill_atps
   681     atp_messages ~> sledgehammer messages
   682     atp_minimize ~> sledgehammer minimize
   683     print_atps   ~> sledgehammer available_atps
   684     INCOMPATIBILITY.
   685   - Added user's manual ("isabelle doc sledgehammer").
   686   - Added option syntax and "sledgehammer_params" to customize
   687     Sledgehammer's behavior.  See the manual for details.
   688   - Modified the Isar proof reconstruction code so that it produces
   689     direct proofs rather than proofs by contradiction.  (This feature
   690     is still experimental.)
   691   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   692     full-typed mode.
   693   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   694 
   695 * Nitpick:
   696   - Added and implemented "binary_ints" and "bits" options.
   697   - Added "std" option and implemented support for nonstandard models.
   698   - Added and implemented "finitize" option to improve the precision
   699     of infinite datatypes based on a monotonicity analysis.
   700   - Added support for quotient types.
   701   - Added support for "specification" and "ax_specification"
   702     constructs.
   703   - Added support for local definitions (for "function" and
   704     "termination" proofs).
   705   - Added support for term postprocessors.
   706   - Optimized "Multiset.multiset" and "FinFun.finfun".
   707   - Improved efficiency of "destroy_constrs" optimization.
   708   - Fixed soundness bugs related to "destroy_constrs" optimization and
   709     record getters.
   710   - Fixed soundness bug related to higher-order constructors.
   711   - Fixed soundness bug when "full_descrs" is enabled.
   712   - Improved precision of set constructs.
   713   - Added "atoms" option.
   714   - Added cache to speed up repeated Kodkod invocations on the same
   715     problems.
   716   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   717     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   718     "SAT4J_Light".  INCOMPATIBILITY.
   719   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   720     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   721   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   722 
   723 * Method "induct" now takes instantiations of the form t, where t is not
   724   a variable, as a shorthand for "x == t", where x is a fresh variable.
   725   If this is not intended, t has to be enclosed in parentheses.
   726   By default, the equalities generated by definitional instantiations
   727   are pre-simplified, which may cause parameters of inductive cases
   728   to disappear, or may even delete some of the inductive cases.
   729   Use "induct (no_simp)" instead of "induct" to restore the old
   730   behaviour. The (no_simp) option is also understood by the "cases"
   731   and "nominal_induct" methods, which now perform pre-simplification, too.
   732   INCOMPATIBILITY.
   733 
   734 
   735 *** HOLCF ***
   736 
   737 * Variable names in lemmas generated by the domain package have
   738 changed; the naming scheme is now consistent with the HOL datatype
   739 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   740 
   741 * The domain package no longer defines the function "foo_copy" for
   742 recursive domain "foo".  The reach lemma is now stated directly in
   743 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   744 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   745 
   746 * Most definedness lemmas generated by the domain package (previously
   747 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   748 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   749 Proofs that used definedness lemmas as intro rules may break,
   750 potential INCOMPATIBILITY.
   751 
   752 * Induction and casedist rules generated by the domain package now
   753 declare proper case_names (one called "bottom", and one named for each
   754 constructor).  INCOMPATIBILITY.
   755 
   756 * For mutually-recursive domains, separate "reach" and "take_lemma"
   757 rules are generated for each domain, INCOMPATIBILITY.
   758 
   759   foo_bar.reach       ~> foo.reach  bar.reach
   760   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   761 
   762 * Some lemmas generated by the domain package have been renamed for
   763 consistency with the datatype package, INCOMPATIBILITY.
   764 
   765   foo.ind        ~> foo.induct
   766   foo.finite_ind ~> foo.finite_induct
   767   foo.coind      ~> foo.coinduct
   768   foo.casedist   ~> foo.exhaust
   769   foo.exhaust    ~> foo.nchotomy
   770 
   771 * For consistency with other definition packages, the fixrec package
   772 now generates qualified theorem names, INCOMPATIBILITY.
   773 
   774   foo_simps  ~> foo.simps
   775   foo_unfold ~> foo.unfold
   776   foo_induct ~> foo.induct
   777 
   778 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   779 method and internal fixrec proofs now use the default simpset instead.
   780 INCOMPATIBILITY.
   781 
   782 * The "contlub" predicate has been removed.  Proof scripts should use
   783 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   784 
   785 * The "admw" predicate has been removed, INCOMPATIBILITY.
   786 
   787 * The constants cpair, cfst, and csnd have been removed in favor of
   788 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   789 
   790 
   791 *** ML ***
   792 
   793 * Antiquotations for basic formal entities:
   794 
   795     @{class NAME}         -- type class
   796     @{class_syntax NAME}  -- syntax representation of the above
   797 
   798     @{type_name NAME}     -- logical type
   799     @{type_abbrev NAME}   -- type abbreviation
   800     @{nonterminal NAME}   -- type of concrete syntactic category
   801     @{type_syntax NAME}   -- syntax representation of any of the above
   802 
   803     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   804     @{const_abbrev NAME}  -- abbreviated constant
   805     @{const_syntax NAME}  -- syntax representation of any of the above
   806 
   807 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   808 syntax constant (cf. 'syntax' command).
   809 
   810 * Antiquotation @{make_string} inlines a function to print arbitrary
   811 values similar to the ML toplevel.  The result is compiler dependent
   812 and may fall back on "?" in certain situations.
   813 
   814 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   815 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   816 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   817 not work with the asynchronous Isar document model.
   818 
   819 * Configuration options now admit dynamic default values, depending on
   820 the context or even global references.
   821 
   822 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   823 uses an efficient external library if available (for Poly/ML).
   824 
   825 * Renamed some important ML structures, while keeping the old names
   826 for some time as aliases within the structure Legacy:
   827 
   828   OuterKeyword  ~>  Keyword
   829   OuterLex      ~>  Token
   830   OuterParse    ~>  Parse
   831   OuterSyntax   ~>  Outer_Syntax
   832   PrintMode     ~>  Print_Mode
   833   SpecParse     ~>  Parse_Spec
   834   ThyInfo       ~>  Thy_Info
   835   ThyLoad       ~>  Thy_Load
   836   ThyOutput     ~>  Thy_Output
   837   TypeInfer     ~>  Type_Infer
   838 
   839 Note that "open Legacy" simplifies porting of sources, but forgetting
   840 to remove it again will complicate porting again in the future.
   841 
   842 * Most operations that refer to a global context are named
   843 accordingly, e.g. Simplifier.global_context or
   844 ProofContext.init_global.  There are some situations where a global
   845 context actually works, but under normal circumstances one needs to
   846 pass the proper local context through the code!
   847 
   848 * Discontinued old TheoryDataFun with its copy/init operation -- data
   849 needs to be pure.  Functor Theory_Data_PP retains the traditional
   850 Pretty.pp argument to merge, which is absent in the standard
   851 Theory_Data version.
   852 
   853 * Sorts.certify_sort and derived "cert" operations for types and terms
   854 no longer minimize sorts.  Thus certification at the boundary of the
   855 inference kernel becomes invariant under addition of class relations,
   856 which is an important monotonicity principle.  Sorts are now minimized
   857 in the syntax layer only, at the boundary between the end-user and the
   858 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   859 explicitly in rare situations.
   860 
   861 * Renamed old-style Drule.standard to Drule.export_without_context, to
   862 emphasize that this is in no way a standard operation.
   863 INCOMPATIBILITY.
   864 
   865 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   866 usual for resolution.  Rare INCOMPATIBILITY.
   867 
   868 * Renamed varify/unvarify operations to varify_global/unvarify_global
   869 to emphasize that these only work in a global situation (which is
   870 quite rare).
   871 
   872 * Curried take and drop in library.ML; negative length is interpreted
   873 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   874 
   875 * Proof terms: type substitutions on proof constants now use canonical
   876 order of type variables.  INCOMPATIBILITY for tools working with proof
   877 terms.
   878 
   879 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   880 may no longer carry premises.  User-level specifications are
   881 transformed accordingly by Thm.add_axiom/add_def.
   882 
   883 
   884 *** System ***
   885 
   886 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   887 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   888 proof terms are enabled unconditionally in the new HOL-Proofs image.
   889 
   890 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   891 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   892 respectively.
   893 
   894 * Old lib/scripts/polyml-platform is superseded by the
   895 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   896 variant, even on a 64 bit machine.  The following example setting
   897 prefers 64 bit if available:
   898 
   899   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   900 
   901 * The preliminary Isabelle/jEdit application demonstrates the emerging
   902 Isabelle/Scala layer for advanced prover interaction and integration.
   903 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   904 component.
   905 
   906 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   907 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   908 similar to the default assignment of the document preparation system
   909 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   910 provides some operations for direct access to the font without asking
   911 the user for manual installation.
   912 
   913 
   914 
   915 New in Isabelle2009-1 (December 2009)
   916 -------------------------------------
   917 
   918 *** General ***
   919 
   920 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   921 one backslash should be used, even in ML sources.
   922 
   923 
   924 *** Pure ***
   925 
   926 * Locale interpretation propagates mixins along the locale hierarchy.
   927 The currently only available mixins are the equations used to map
   928 local definitions to terms of the target domain of an interpretation.
   929 
   930 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   931 loc" to print all interpretations of locale "loc" in the theory.
   932 Interpretations in proofs are not shown.
   933 
   934 * Thoroughly revised locales tutorial.  New section on conditional
   935 interpretation.
   936 
   937 * On instantiation of classes, remaining undefined class parameters
   938 are formally declared.  INCOMPATIBILITY.
   939 
   940 
   941 *** Document preparation ***
   942 
   943 * New generalized style concept for printing terms: @{foo (style) ...}
   944 instead of @{foo_style style ...}  (old form is still retained for
   945 backward compatibility).  Styles can be also applied for
   946 antiquotations prop, term_type and typeof.
   947 
   948 
   949 *** HOL ***
   950 
   951 * New proof method "smt" for a combination of first-order logic with
   952 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   953 fixed-size bitvectors; there is also basic support for higher-order
   954 features (esp. lambda abstractions).  It is an incomplete decision
   955 procedure based on external SMT solvers using the oracle mechanism;
   956 for the SMT solver Z3, this method is proof-producing.  Certificates
   957 are provided to avoid calling the external solvers solely for
   958 re-checking proofs.  Due to a remote SMT service there is no need for
   959 installing SMT solvers locally.  See src/HOL/SMT.
   960 
   961 * New commands to load and prove verification conditions generated by
   962 the Boogie program verifier or derived systems (e.g. the Verifying C
   963 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   964 
   965 * New counterexample generator tool 'nitpick' based on the Kodkod
   966 relational model finder.  See src/HOL/Tools/Nitpick and
   967 src/HOL/Nitpick_Examples.
   968 
   969 * New commands 'code_pred' and 'values' to invoke the predicate
   970 compiler and to enumerate values of inductive predicates.
   971 
   972 * A tabled implementation of the reflexive transitive closure.
   973 
   974 * New implementation of quickcheck uses generic code generator;
   975 default generators are provided for all suitable HOL types, records
   976 and datatypes.  Old quickcheck can be re-activated importing theory
   977 Library/SML_Quickcheck.
   978 
   979 * New testing tool Mirabelle for automated proof tools.  Applies
   980 several tools and tactics like sledgehammer, metis, or quickcheck, to
   981 every proof step in a theory.  To be used in batch mode via the
   982 "mirabelle" utility.
   983 
   984 * New proof method "sos" (sum of squares) for nonlinear real
   985 arithmetic (originally due to John Harison). It requires theory
   986 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   987 works well in practice on quantifier-free real arithmetic with +, -,
   988 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   989 inequalities between polynomials.  It makes use of external
   990 semidefinite programming solvers.  Method "sos" generates a
   991 certificate that can be pasted into the proof thus avoiding the need
   992 to call an external tool every time the proof is checked.  See
   993 src/HOL/Library/Sum_Of_Squares.
   994 
   995 * New method "linarith" invokes existing linear arithmetic decision
   996 procedure only.
   997 
   998 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   999 
  1000 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1001 Causes full type information to be output to the ATPs.  This slows
  1002 ATPs down considerably but eliminates a source of unsound "proofs"
  1003 that fail later.
  1004 
  1005 * New method "metisFT": A version of metis that uses full type
  1006 information in order to avoid failures of proof reconstruction.
  1007 
  1008 * New evaluator "approximate" approximates an real valued term using
  1009 the same method as the approximation method.
  1010 
  1011 * Method "approximate" now supports arithmetic expressions as
  1012 boundaries of intervals and implements interval splitting and Taylor
  1013 series expansion.
  1014 
  1015 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1016 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1017 
  1018 * New theory SupInf of the supremum and infimum operators for sets of
  1019 reals.
  1020 
  1021 * New theory Probability, which contains a development of measure
  1022 theory, eventually leading to Lebesgue integration and probability.
  1023 
  1024 * Extended Multivariate Analysis to include derivation and Brouwer's
  1025 fixpoint theorem.
  1026 
  1027 * Reorganization of number theory, INCOMPATIBILITY:
  1028   - new number theory development for nat and int, in theories Divides
  1029     and GCD as well as in new session Number_Theory
  1030   - some constants and facts now suffixed with _nat and _int
  1031     accordingly
  1032   - former session NumberTheory now named Old_Number_Theory, including
  1033     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1034   - moved theory Pocklington from src/HOL/Library to
  1035     src/HOL/Old_Number_Theory
  1036 
  1037 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1038 lcm of finite and infinite sets. It is shown that they form a complete
  1039 lattice.
  1040 
  1041 * Class semiring_div requires superclass no_zero_divisors and proof of
  1042 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1043 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1044 generalized to class semiring_div, subsuming former theorems
  1045 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1046 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1047 INCOMPATIBILITY.
  1048 
  1049 * Refinements to lattice classes and sets:
  1050   - less default intro/elim rules in locale variant, more default
  1051     intro/elim rules in class variant: more uniformity
  1052   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1053     le_inf_iff
  1054   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1055     sup_aci)
  1056   - renamed ACI to inf_sup_aci
  1057   - new class "boolean_algebra"
  1058   - class "complete_lattice" moved to separate theory
  1059     "Complete_Lattice"; corresponding constants (and abbreviations)
  1060     renamed and with authentic syntax:
  1061     Set.Inf ~>    Complete_Lattice.Inf
  1062     Set.Sup ~>    Complete_Lattice.Sup
  1063     Set.INFI ~>   Complete_Lattice.INFI
  1064     Set.SUPR ~>   Complete_Lattice.SUPR
  1065     Set.Inter ~>  Complete_Lattice.Inter
  1066     Set.Union ~>  Complete_Lattice.Union
  1067     Set.INTER ~>  Complete_Lattice.INTER
  1068     Set.UNION ~>  Complete_Lattice.UNION
  1069   - authentic syntax for
  1070     Set.Pow
  1071     Set.image
  1072   - mere abbreviations:
  1073     Set.empty               (for bot)
  1074     Set.UNIV                (for top)
  1075     Set.inter               (for inf, formerly Set.Int)
  1076     Set.union               (for sup, formerly Set.Un)
  1077     Complete_Lattice.Inter  (for Inf)
  1078     Complete_Lattice.Union  (for Sup)
  1079     Complete_Lattice.INTER  (for INFI)
  1080     Complete_Lattice.UNION  (for SUPR)
  1081   - object-logic definitions as far as appropriate
  1082 
  1083 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1084 Un_subset_iff are explicitly deleted as default simp rules; then also
  1085 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1086 deleted to achieve the desired effect.
  1087 
  1088 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1089 rules by default any longer; the same applies to min_max.inf_absorb1
  1090 etc.  INCOMPATIBILITY.
  1091 
  1092 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1093 pred_set_conv by default.  INCOMPATIBILITY.
  1094 
  1095 * Power operations on relations and functions are now one dedicated
  1096 constant "compow" with infix syntax "^^".  Power operation on
  1097 multiplicative monoids retains syntax "^" and is now defined generic
  1098 in class power.  INCOMPATIBILITY.
  1099 
  1100 * Relation composition "R O S" now has a more standard argument order:
  1101 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1102 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1103 break, since the O_assoc rule was not rewritten like this.  Fix using
  1104 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1105 
  1106 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1107 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1108 INCOMPATIBILITY.
  1109 
  1110 * Most rules produced by inductive and datatype package have mandatory
  1111 prefixes.  INCOMPATIBILITY.
  1112 
  1113 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1114 the attribute of the same name.  Each of the theorems in the list
  1115 DERIV_intros assumes composition with an additional function and
  1116 matches a variable to the derivative, which has to be solved by the
  1117 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1118 of most elementary terms.  Former Maclauren.DERIV_tac and
  1119 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1120 INCOMPATIBILITY.
  1121 
  1122 * Code generator attributes follow the usual underscore convention:
  1123     code_unfold     replaces    code unfold
  1124     code_post       replaces    code post
  1125     etc.
  1126   INCOMPATIBILITY.
  1127 
  1128 * Renamed methods:
  1129     sizechange -> size_change
  1130     induct_scheme -> induction_schema
  1131   INCOMPATIBILITY.
  1132 
  1133 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1134 INCOMPATIBILITY, use "undefined" directly.
  1135 
  1136 * Renamed theorems:
  1137     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1138     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1139     Suc_plus1 -> Suc_eq_plus1
  1140     *anti_sym -> *antisym*
  1141     vector_less_eq_def -> vector_le_def
  1142   INCOMPATIBILITY.
  1143 
  1144 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1145 INCOMPATIBILITY.
  1146 
  1147 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1148 INCOMPATIBILITY.
  1149 
  1150 
  1151 *** HOLCF ***
  1152 
  1153 * Theory Representable defines a class "rep" of domains that are
  1154 representable (via an ep-pair) in the universal domain type "udom".
  1155 Instances are provided for all type constructors defined in HOLCF.
  1156 
  1157 * The 'new_domain' command is a purely definitional version of the
  1158 domain package, for representable domains.  Syntax is identical to the
  1159 old domain package.  The 'new_domain' package also supports indirect
  1160 recursion using previously-defined type constructors.  See
  1161 src/HOLCF/ex/New_Domain.thy for examples.
  1162 
  1163 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1164 on the left-hand side of an equation, and then performs
  1165 simplification.  Rewriting is done using rules declared with the
  1166 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1167 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1168 
  1169 * The pattern-match compiler in 'fixrec' can now handle constructors
  1170 with HOL function types.  Pattern-match combinators for the Pair
  1171 constructor are pre-configured.
  1172 
  1173 * The 'fixrec' package now produces better fixed-point induction rules
  1174 for mutually-recursive definitions:  Induction rules have conclusions
  1175 of the form "P foo bar" instead of "P <foo, bar>".
  1176 
  1177 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1178 been renamed to "below".  The name "below" now replaces "less" in many
  1179 theorem names.  (Legacy theorem names using "less" are still supported
  1180 as well.)
  1181 
  1182 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1183 patterns can be used to generate strictness rules, or to make
  1184 functions more strict (much like the bang-patterns supported by the
  1185 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1186 examples.
  1187 
  1188 
  1189 *** ML ***
  1190 
  1191 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1192 errors and run-time exceptions, including detailed source positions.
  1193 
  1194 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1195 identified entries, with some additional information such as source
  1196 position, logical grouping etc.
  1197 
  1198 * Theory and context data is now introduced by the simplified and
  1199 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1200 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1201 copy operation) is still available for some time.
  1202 
  1203 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1204 provides a high-level programming interface to synchronized state
  1205 variables with atomic update.  This works via pure function
  1206 application within a critical section -- its runtime should be as
  1207 short as possible; beware of deadlocks if critical code is nested,
  1208 either directly or indirectly via other synchronized variables!
  1209 
  1210 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1211 wraps raw ML references, explicitly indicating their non-thread-safe
  1212 behaviour.  The Isar toplevel keeps this structure open, to
  1213 accommodate Proof General as well as quick and dirty interactive
  1214 experiments with references.
  1215 
  1216 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1217 parallel tactical reasoning.
  1218 
  1219 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1220 are similar to SUBPROOF, but are slightly more flexible: only the
  1221 specified parts of the subgoal are imported into the context, and the
  1222 body tactic may introduce new subgoals and schematic variables.
  1223 
  1224 * Old tactical METAHYPS, which does not observe the proof context, has
  1225 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1226 or Subgoal.FOCUS etc.
  1227 
  1228 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1229 functors have their own ML name space there is no point to mark them
  1230 separately.)  Minor INCOMPATIBILITY.
  1231 
  1232 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1233 
  1234 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1235 INCOMPATIBILITY.
  1236 
  1237 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1238 mode, which avoids critical setmp.
  1239 
  1240 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1241 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1242 Attrib/Method.setup introduced in Isabelle2009.
  1243 
  1244 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1245 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1246 last resort.  INCOMPATIBILITY.
  1247 
  1248 * Display.pretty_thm now requires a proper context (cf. former
  1249 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1250 or even Display.pretty_thm_without_context as last resort.
  1251 INCOMPATIBILITY.
  1252 
  1253 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1254 Syntax.pretty_typ/term directly, preferably with proper context
  1255 instead of global theory.
  1256 
  1257 
  1258 *** System ***
  1259 
  1260 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1261 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1262 usedir option -q.
  1263 
  1264 * Support for additional "Isabelle components" via etc/components, see
  1265 also the system manual.
  1266 
  1267 * The isabelle makeall tool now operates on all components with
  1268 IsaMakefile, not just hardwired "logics".
  1269 
  1270 * Removed "compress" option from isabelle-process and isabelle usedir;
  1271 this is always enabled.
  1272 
  1273 * Discontinued support for Poly/ML 4.x versions.
  1274 
  1275 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1276 on a given logic image.  This requires the lighttpd webserver and is
  1277 currently supported on Linux only.
  1278 
  1279 
  1280 
  1281 New in Isabelle2009 (April 2009)
  1282 --------------------------------
  1283 
  1284 *** General ***
  1285 
  1286 * Simplified main Isabelle executables, with less surprises on
  1287 case-insensitive file-systems (such as Mac OS).
  1288 
  1289   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1290     "isatool."
  1291 
  1292   - The former "isabelle" alias for "isabelle-process" has been
  1293     removed (should rarely occur to regular users).
  1294 
  1295   - The former "isabelle-interface" and its alias "Isabelle" have been
  1296     removed (interfaces are now regular Isabelle tools).
  1297 
  1298 Within scripts and make files, the Isabelle environment variables
  1299 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1300 respectively.  (The latter are still available as legacy feature.)
  1301 
  1302 The old isabelle-interface wrapper could react in confusing ways if
  1303 the interface was uninstalled or changed otherwise.  Individual
  1304 interface tool configuration is now more explicit, see also the
  1305 Isabelle system manual.  In particular, Proof General is now available
  1306 via "isabelle emacs".
  1307 
  1308 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1309 purge installed copies of Isabelle executables and re-run "isabelle
  1310 install -p ...", or use symlinks.
  1311 
  1312 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1313 old ~/isabelle, which was slightly non-standard and apt to cause
  1314 surprises on case-insensitive file-systems (such as Mac OS).
  1315 
  1316 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1317 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1318 care is required when using older releases of Isabelle.  Note that
  1319 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1320 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1321 
  1322 * Proofs of fully specified statements are run in parallel on
  1323 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1324 a regular 4-core machine, if the initial heap space is made reasonably
  1325 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1326 
  1327 * The main reference manuals ("isar-ref", "implementation", and
  1328 "system") have been updated and extended.  Formally checked references
  1329 as hyperlinks are now available uniformly.
  1330 
  1331 
  1332 *** Pure ***
  1333 
  1334 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1335 respects.  The most important changes are listed below.  See the
  1336 Tutorial on Locales ("locales" manual) for details.
  1337 
  1338 - In locale expressions, instantiation replaces renaming.  Parameters
  1339 must be declared in a for clause.  To aid compatibility with previous
  1340 parameter inheritance, in locale declarations, parameters that are not
  1341 'touched' (instantiation position "_" or omitted) are implicitly added
  1342 with their syntax at the beginning of the for clause.
  1343 
  1344 - Syntax from abbreviations and definitions in locales is available in
  1345 locale expressions and context elements.  The latter is particularly
  1346 useful in locale declarations.
  1347 
  1348 - More flexible mechanisms to qualify names generated by locale
  1349 expressions.  Qualifiers (prefixes) may be specified in locale
  1350 expressions, and can be marked as mandatory (syntax: "name!:") or
  1351 optional (syntax "name?:").  The default depends for plain "name:"
  1352 depends on the situation where a locale expression is used: in
  1353 commands 'locale' and 'sublocale' prefixes are optional, in
  1354 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1355 implicit qualifiers derived from the parameter names of a locale are
  1356 no longer generated.
  1357 
  1358 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1359 instantiation clause in "interpretation" and "interpret" (square
  1360 brackets) is no longer available.  Use locale expressions.
  1361 
  1362 - When converting proof scripts, mandatory qualifiers in
  1363 'interpretation' and 'interpret' should be retained by default, even
  1364 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1365 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1366 in locale expressions range over a single locale instance only.
  1367 
  1368 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1369 In existing theorem specifications replace the includes element by the
  1370 respective context elements of the included locale, omitting those
  1371 that are already present in the theorem specification.  Multiple
  1372 assume elements of a locale should be replaced by a single one
  1373 involving the locale predicate.  In the proof body, declarations (most
  1374 notably theorems) may be regained by interpreting the respective
  1375 locales in the proof context as required (command "interpret").
  1376 
  1377 If using "includes" in replacement of a target solely because the
  1378 parameter types in the theorem are not as general as in the target,
  1379 consider declaring a new locale with additional type constraints on
  1380 the parameters (context element "constrains").
  1381 
  1382 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1383 
  1384 - Locale interpretation commands no longer attempt to simplify goal.
  1385 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1386 methods intro_locales and unfold_locales to clarify.
  1387 
  1388 - Locale interpretation commands no longer accept interpretation
  1389 attributes.  INCOMPATIBILITY.
  1390 
  1391 * Class declaration: so-called "base sort" must not be given in import
  1392 list any longer, but is inferred from the specification.  Particularly
  1393 in HOL, write
  1394 
  1395     class foo = ...
  1396 
  1397 instead of
  1398 
  1399     class foo = type + ...
  1400 
  1401 * Class target: global versions of theorems stemming do not carry a
  1402 parameter prefix any longer.  INCOMPATIBILITY.
  1403 
  1404 * Class 'instance' command no longer accepts attached definitions.
  1405 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1406 
  1407 * Recovered hiding of consts, which was accidentally broken in
  1408 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1409 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1410 
  1411 * Slightly more coherent Pure syntax, with updated documentation in
  1412 isar-ref manual.  Removed locales meta_term_syntax and
  1413 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1414 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1415 directly in regular applications.
  1416 
  1417 * There is a new syntactic category "float_const" for signed decimal
  1418 fractions (e.g. 123.45 or -123.45).
  1419 
  1420 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1421 interface with 'setup' command instead.
  1422 
  1423 * Command 'local_setup' is similar to 'setup', but operates on a local
  1424 theory context.
  1425 
  1426 * The 'axiomatization' command now only works within a global theory
  1427 context.  INCOMPATIBILITY.
  1428 
  1429 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1430 hypotheses.  Sorts required in the course of reasoning need to be
  1431 covered by the constraints in the initial statement, completed by the
  1432 type instance information of the background theory.  Non-trivial sort
  1433 hypotheses, which rarely occur in practice, may be specified via
  1434 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1435 
  1436   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1437 
  1438 The result contains an implicit sort hypotheses as before --
  1439 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1440 normalization.
  1441 
  1442 * Generalized Isar history, with support for linear undo, direct state
  1443 addressing etc.
  1444 
  1445 * Changed defaults for unify configuration options:
  1446 
  1447   unify_trace_bound = 50 (formerly 25)
  1448   unify_search_bound = 60 (formerly 30)
  1449 
  1450 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1451 
  1452   a) On theory merge, the last set of code equations for a particular
  1453      constant is taken (in accordance with the policy applied by other
  1454      parts of the code generator framework).
  1455 
  1456   b) Code equations stemming from explicit declarations (e.g. code
  1457      attribute) gain priority over default code equations stemming
  1458      from definition, primrec, fun etc.
  1459 
  1460 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1461 
  1462 * Unified theorem tables for both code generators.  Thus [code
  1463 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1464 
  1465 * Command 'find_consts' searches for constants based on type and name
  1466 patterns, e.g.
  1467 
  1468     find_consts "_ => bool"
  1469 
  1470 By default, matching is against subtypes, but it may be restricted to
  1471 the whole type.  Searching by name is possible.  Multiple queries are
  1472 conjunctive and queries may be negated by prefixing them with a
  1473 hyphen:
  1474 
  1475     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1476 
  1477 * New 'find_theorems' criterion "solves" matches theorems that
  1478 directly solve the current goal (modulo higher-order unification).
  1479 
  1480 * Auto solve feature for main theorem statements: whenever a new goal
  1481 is stated, "find_theorems solves" is called; any theorems that could
  1482 solve the lemma directly are listed as part of the goal state.
  1483 Cf. associated options in Proof General Isabelle settings menu,
  1484 enabled by default, with reasonable timeout for pathological cases of
  1485 higher-order unification.
  1486 
  1487 
  1488 *** Document preparation ***
  1489 
  1490 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1491 demanding keyword 'by' and supporting the full method expression
  1492 syntax just like the Isar command 'by'.
  1493 
  1494 
  1495 *** HOL ***
  1496 
  1497 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1498 points Main and Complex_Main remain as before.
  1499 
  1500 * Logic image HOL-Plain provides a minimal HOL with the most important
  1501 tools available (inductive, datatype, primrec, ...).  This facilitates
  1502 experimentation and tool development.  Note that user applications
  1503 (and library theories) should never refer to anything below theory
  1504 Main, as before.
  1505 
  1506 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1507 experimentation due to shorter build times.
  1508 
  1509 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1510 were previously part of former HOL-Complex.  Entry point Hyperreal
  1511 remains valid, but theories formerly using Complex_Main should now use
  1512 new entry point Hypercomplex.
  1513 
  1514 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1515 Posix processes.  Avoids potentially expensive forking of the ML
  1516 process.  New thread-based implementation also works on non-Unix
  1517 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1518 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1519 commands are covered in the isar-ref manual.
  1520 
  1521 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1522 sledgehammer without local ATP installation (Vampire etc.). Other
  1523 provers may be included via suitable ML wrappers, see also
  1524 src/HOL/ATP_Linkup.thy.
  1525 
  1526 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1527 menu.
  1528 
  1529 * The metis method no longer fails because the theorem is too trivial
  1530 (contains the empty clause).
  1531 
  1532 * The metis method now fails in the usual manner, rather than raising
  1533 an exception, if it determines that it cannot prove the theorem.
  1534 
  1535 * Method "coherent" implements a prover for coherent logic (see also
  1536 src/Tools/coherent.ML).
  1537 
  1538 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1539 "undefined" is the right choice to replace "arbitrary", though
  1540 logically there is no difference.  INCOMPATIBILITY.
  1541 
  1542 * Command "value" now integrates different evaluation mechanisms.  The
  1543 result of the first successful evaluation mechanism is printed.  In
  1544 square brackets a particular named evaluation mechanisms may be
  1545 specified (currently, [SML], [code] or [nbe]).  See further
  1546 src/HOL/ex/Eval_Examples.thy.
  1547 
  1548 * Normalization by evaluation now allows non-leftlinear equations.
  1549 Declare with attribute [code nbe].
  1550 
  1551 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1552 as the structured Isar versions "cases" and "induct", cf. the
  1553 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1554 are now presented as a list of individual projections
  1555 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1556 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1557 rare situations a different rule is selected --- notably nested tuple
  1558 elimination instead of former prod.exhaust: use explicit (case_tac t
  1559 rule: prod.exhaust) here.
  1560 
  1561 * Attributes "cases", "induct", "coinduct" support "del" option.
  1562 
  1563 * Removed fact "case_split_thm", which duplicates "case_split".
  1564 
  1565 * The option datatype has been moved to a new theory Option.  Renamed
  1566 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1567 
  1568 * New predicate "strict_mono" classifies strict functions on partial
  1569 orders.  With strict functions on linear orders, reasoning about
  1570 (in)equalities is facilitated by theorems "strict_mono_eq",
  1571 "strict_mono_less_eq" and "strict_mono_less".
  1572 
  1573 * Some set operations are now proper qualified constants with
  1574 authentic syntax.  INCOMPATIBILITY:
  1575 
  1576     op Int ~>   Set.Int
  1577     op Un ~>    Set.Un
  1578     INTER ~>    Set.INTER
  1579     UNION ~>    Set.UNION
  1580     Inter ~>    Set.Inter
  1581     Union ~>    Set.Union
  1582     {} ~>       Set.empty
  1583     UNIV ~>     Set.UNIV
  1584 
  1585 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1586 theory Set.
  1587 
  1588 * Auxiliary class "itself" has disappeared -- classes without any
  1589 parameter are treated as expected by the 'class' command.
  1590 
  1591 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1592 
  1593 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1594 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1595 
  1596 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1597 method "approximation".  It proves formulas on real values by using
  1598 interval arithmetic.  In the formulas are also the transcendental
  1599 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1600 allowed. For examples see
  1601 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1602 
  1603 * Theory "Reflection" now resides in HOL/Library.
  1604 
  1605 * Entry point to Word library now simply named "Word".
  1606 INCOMPATIBILITY.
  1607 
  1608 * Made source layout more coherent with logical distribution
  1609 structure:
  1610 
  1611     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1612     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1613     src/HOL/Library/GCD.thy ~> src/HOL/
  1614     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1615     src/HOL/Library/Parity.thy ~> src/HOL/
  1616     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1617     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1618     src/HOL/Real/Lubs.thy ~> src/HOL/
  1619     src/HOL/Real/PReal.thy ~> src/HOL/
  1620     src/HOL/Real/Rational.thy ~> src/HOL/
  1621     src/HOL/Real/RComplete.thy ~> src/HOL/
  1622     src/HOL/Real/RealDef.thy ~> src/HOL/
  1623     src/HOL/Real/RealPow.thy ~> src/HOL/
  1624     src/HOL/Real/Real.thy ~> src/HOL/
  1625     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1626     src/HOL/Complex/Complex.thy ~> src/HOL/
  1627     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1628     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1629     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1630     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1631     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1632     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1633     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1634     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1635     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1636     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1637     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1638     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1639     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1640     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1641     src/HOL/Real/Float ~> src/HOL/Library/
  1642     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1643     src/HOL/Real/RealVector.thy ~> src/HOL/
  1644 
  1645     src/HOL/arith_data.ML ~> src/HOL/Tools
  1646     src/HOL/hologic.ML ~> src/HOL/Tools
  1647     src/HOL/simpdata.ML ~> src/HOL/Tools
  1648     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1649     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1650     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1651     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1652     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1653     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1654     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1655 
  1656     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1657     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1658     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1659     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1660     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1661     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1662 
  1663 * If methods "eval" and "evaluation" encounter a structured proof
  1664 state with !!/==>, only the conclusion is evaluated to True (if
  1665 possible), avoiding strange error messages.
  1666 
  1667 * Method "sizechange" automates termination proofs using (a
  1668 modification of) the size-change principle.  Requires SAT solver.  See
  1669 src/HOL/ex/Termination.thy for examples.
  1670 
  1671 * Simplifier: simproc for let expressions now unfolds if bound
  1672 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1673 
  1674 * Method "arith": Linear arithmetic now ignores all inequalities when
  1675 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1676 
  1677 * New attribute "arith" for facts that should always be used
  1678 automatically by arithmetic. It is intended to be used locally in
  1679 proofs, e.g.
  1680 
  1681   assumes [arith]: "x > 0"
  1682 
  1683 Global usage is discouraged because of possible performance impact.
  1684 
  1685 * New classes "top" and "bot" with corresponding operations "top" and
  1686 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1687 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1688 
  1689 * Changed definition lemma "less_fun_def" in order to provide an
  1690 instance for preorders on functions; use lemma "less_le" instead.
  1691 INCOMPATIBILITY.
  1692 
  1693 * Theory Orderings: class "wellorder" moved here, with explicit
  1694 induction rule "less_induct" as assumption.  For instantiation of
  1695 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1696 INCOMPATIBILITY.
  1697 
  1698 * Theory Orderings: added class "preorder" as superclass of "order".
  1699 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1700 etc. slightly changed.  Some theorems named order_class.* now named
  1701 preorder_class.*.
  1702 
  1703 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1704 "diag" to "Id_on".
  1705 
  1706 * Theory Finite_Set: added a new fold combinator of type
  1707 
  1708   ('a => 'b => 'b) => 'b => 'a set => 'b
  1709 
  1710 Occasionally this is more convenient than the old fold combinator
  1711 which is now defined in terms of the new one and renamed to
  1712 fold_image.
  1713 
  1714 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1715 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1716 extended with further lemmas!).  At the moment both still exist but
  1717 the former will disappear at some point.
  1718 
  1719 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1720 class recpower.  Type-specific simp rules for various recpower types
  1721 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1722 
  1723 rat_power_0    -> power_0
  1724 rat_power_Suc  -> power_Suc
  1725 realpow_0      -> power_0
  1726 realpow_Suc    -> power_Suc
  1727 complexpow_0   -> power_0
  1728 complexpow_Suc -> power_Suc
  1729 power_poly_0   -> power_0
  1730 power_poly_Suc -> power_Suc
  1731 
  1732 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1733 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1734 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1735 of lemmas from Divides has been generalized from nat to class
  1736 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1737 renames resulting from duplicate elimination:
  1738 
  1739     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1740     zero_dvd_iff ~>         dvd_0_left_iff
  1741     dvd_0 ~>                dvd_0_right
  1742     DIVISION_BY_ZERO_DIV ~> div_by_0
  1743     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1744     mult_div ~>             div_mult_self2_is_id
  1745     mult_mod ~>             mod_mult_self2_is_0
  1746 
  1747 * Theory IntDiv: removed many lemmas that are instances of class-based
  1748 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1749 rename old lemmas as follows:
  1750 
  1751 dvd_diff               -> nat_dvd_diff
  1752 dvd_zminus_iff         -> dvd_minus_iff
  1753 mod_add1_eq            -> mod_add_eq
  1754 mod_mult1_eq           -> mod_mult_right_eq
  1755 mod_mult1_eq'          -> mod_mult_left_eq
  1756 mod_mult_distrib_mod   -> mod_mult_eq
  1757 nat_mod_add_left_eq    -> mod_add_left_eq
  1758 nat_mod_add_right_eq   -> mod_add_right_eq
  1759 nat_mod_div_trivial    -> mod_div_trivial
  1760 nat_mod_mod_trivial    -> mod_mod_trivial
  1761 zdiv_zadd_self1        -> div_add_self1
  1762 zdiv_zadd_self2        -> div_add_self2
  1763 zdiv_zmult_self1       -> div_mult_self2_is_id
  1764 zdiv_zmult_self2       -> div_mult_self1_is_id
  1765 zdvd_triv_left         -> dvd_triv_left
  1766 zdvd_triv_right        -> dvd_triv_right
  1767 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1768 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1769 zmod_zadd_left_eq      -> mod_add_left_eq
  1770 zmod_zadd_right_eq     -> mod_add_right_eq
  1771 zmod_zadd_self1        -> mod_add_self1
  1772 zmod_zadd_self2        -> mod_add_self2
  1773 zmod_zadd1_eq          -> mod_add_eq
  1774 zmod_zdiff1_eq         -> mod_diff_eq
  1775 zmod_zdvd_zmod         -> mod_mod_cancel
  1776 zmod_zmod_cancel       -> mod_mod_cancel
  1777 zmod_zmult_self1       -> mod_mult_self2_is_0
  1778 zmod_zmult_self2       -> mod_mult_self1_is_0
  1779 zmod_1                 -> mod_by_1
  1780 zdiv_1                 -> div_by_1
  1781 zdvd_abs1              -> abs_dvd_iff
  1782 zdvd_abs2              -> dvd_abs_iff
  1783 zdvd_refl              -> dvd_refl
  1784 zdvd_trans             -> dvd_trans
  1785 zdvd_zadd              -> dvd_add
  1786 zdvd_zdiff             -> dvd_diff
  1787 zdvd_zminus_iff        -> dvd_minus_iff
  1788 zdvd_zminus2_iff       -> minus_dvd_iff
  1789 zdvd_zmultD            -> dvd_mult_right
  1790 zdvd_zmultD2           -> dvd_mult_left
  1791 zdvd_zmult_mono        -> mult_dvd_mono
  1792 zdvd_0_right           -> dvd_0_right
  1793 zdvd_0_left            -> dvd_0_left_iff
  1794 zdvd_1_left            -> one_dvd
  1795 zminus_dvd_iff         -> minus_dvd_iff
  1796 
  1797 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1798 
  1799 * The real numbers offer decimal input syntax: 12.34 is translated
  1800 into 1234/10^2. This translation is not reversed upon output.
  1801 
  1802 * Theory Library/Polynomial defines an abstract type 'a poly of
  1803 univariate polynomials with coefficients of type 'a.  In addition to
  1804 the standard ring operations, it also supports div and mod.  Code
  1805 generation is also supported, using list-style constructors.
  1806 
  1807 * Theory Library/Inner_Product defines a class of real_inner for real
  1808 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1809 => real.  Class real_inner is a subclass of real_normed_vector from
  1810 theory RealVector.
  1811 
  1812 * Theory Library/Product_Vector provides instances for the product
  1813 type 'a * 'b of several classes from RealVector and Inner_Product.
  1814 Definitions of addition, subtraction, scalar multiplication, norms,
  1815 and inner products are included.
  1816 
  1817 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1818 addition to the field operations, numerals and case syntax are also
  1819 supported.
  1820 
  1821 * Theory Library/Diagonalize provides constructive version of Cantor's
  1822 first diagonalization argument.
  1823 
  1824 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1825 zlcm (for int); carried together from various gcd/lcm developements in
  1826 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1827 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1828 may recover tupled syntax as follows:
  1829 
  1830     hide (open) const gcd
  1831     abbreviation gcd where
  1832       "gcd == (%(a, b). GCD.gcd a b)"
  1833     notation (output)
  1834       GCD.gcd ("gcd '(_, _')")
  1835 
  1836 The same works for lcm, zgcd, zlcm.
  1837 
  1838 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1839 instantiations for algebraic structures.  Removed some duplicate
  1840 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1841 
  1842 * ML antiquotation @{code} takes a constant as argument and generates
  1843 corresponding code in background and inserts name of the corresponding
  1844 resulting ML value/function/datatype constructor binding in place.
  1845 All occurrences of @{code} with a single ML block are generated
  1846 simultaneously.  Provides a generic and safe interface for
  1847 instrumentalizing code generation.  See
  1848 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1849 In future you ought to refrain from ad-hoc compiling generated SML
  1850 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1851 cannot refer to constants for which user-defined serializations are
  1852 set.  Refer to the corresponding ML counterpart directly in that
  1853 cases.
  1854 
  1855 * Command 'rep_datatype': instead of theorem names the command now
  1856 takes a list of terms denoting the constructors of the type to be
  1857 represented as datatype.  The characteristic theorems have to be
  1858 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1859 have disappeared in favour of existing ones:
  1860 
  1861     unit_induct                 ~> unit.induct
  1862     prod_induct                 ~> prod.induct
  1863     sum_induct                  ~> sum.induct
  1864     Suc_Suc_eq                  ~> nat.inject
  1865     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1866 
  1867 
  1868 *** HOL-Algebra ***
  1869 
  1870 * New locales for orders and lattices where the equivalence relation
  1871 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1872 locales use a record structure with field eq for the equivalence.
  1873 
  1874 * New theory of factorial domains.
  1875 
  1876 * Units_l_inv and Units_r_inv are now simp rules by default.
  1877 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1878 and/or r_inv will now also require deletion of these lemmas.
  1879 
  1880 * Renamed the following theorems, INCOMPATIBILITY:
  1881 
  1882 UpperD ~> Upper_memD
  1883 LowerD ~> Lower_memD
  1884 least_carrier ~> least_closed
  1885 greatest_carrier ~> greatest_closed
  1886 greatest_Lower_above ~> greatest_Lower_below
  1887 one_zero ~> carrier_one_zero
  1888 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1889 
  1890 
  1891 *** HOL-Nominal ***
  1892 
  1893 * Nominal datatypes can now contain type-variables.
  1894 
  1895 * Commands 'nominal_inductive' and 'equivariance' work with local
  1896 theory targets.
  1897 
  1898 * Nominal primrec can now works with local theory targets and its
  1899 specification syntax now conforms to the general format as seen in
  1900 'inductive' etc.
  1901 
  1902 * Method "perm_simp" honours the standard simplifier attributes
  1903 (no_asm), (no_asm_use) etc.
  1904 
  1905 * The new predicate #* is defined like freshness, except that on the
  1906 left hand side can be a set or list of atoms.
  1907 
  1908 * Experimental command 'nominal_inductive2' derives strong induction
  1909 principles for inductive definitions.  In contrast to
  1910 'nominal_inductive', which can only deal with a fixed number of
  1911 binders, it can deal with arbitrary expressions standing for sets of
  1912 atoms to be avoided.  The only inductive definition we have at the
  1913 moment that needs this generalisation is the typing rule for Lets in
  1914 the algorithm W:
  1915 
  1916  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1917  -----------------------------------------------------------------
  1918          Gamma |- Let x be t1 in t2 : T2
  1919 
  1920 In this rule one wants to avoid all the binders that are introduced by
  1921 "close Gamma T1".  We are looking for other examples where this
  1922 feature might be useful.  Please let us know.
  1923 
  1924 
  1925 *** HOLCF ***
  1926 
  1927 * Reimplemented the simplification procedure for proving continuity
  1928 subgoals.  The new simproc is extensible; users can declare additional
  1929 continuity introduction rules with the attribute [cont2cont].
  1930 
  1931 * The continuity simproc now uses a different introduction rule for
  1932 solving continuity subgoals on terms with lambda abstractions.  In
  1933 some rare cases the new simproc may fail to solve subgoals that the
  1934 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1935 Potential INCOMPATIBILITY.
  1936 
  1937 * Command 'fixrec': specification syntax now conforms to the general
  1938 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1939 examples.  INCOMPATIBILITY.
  1940 
  1941 
  1942 *** ZF ***
  1943 
  1944 * Proof of Zorn's Lemma for partial orders.
  1945 
  1946 
  1947 *** ML ***
  1948 
  1949 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1950 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1951 depends on multithreading, so timouts will not work before Poly/ML
  1952 5.2.1!
  1953 
  1954 * High-level support for concurrent ML programming, see
  1955 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1956 particularly convenient to organize independent functional
  1957 computations.  The concept of "synchronized variables" provides a
  1958 higher-order interface for components with shared state, avoiding the
  1959 delicate details of mutexes and condition variables.  (Requires
  1960 Poly/ML 5.2.1 or later.)
  1961 
  1962 * ML bindings produced via Isar commands are stored within the Isar
  1963 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1964 become thread-safe and work with undo as expected (concerning
  1965 top-level bindings, not side-effects on global references).
  1966 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1967 compiler at runtime; really global bindings need to be given outside a
  1968 theory.  (Requires Poly/ML 5.2 or later.)
  1969 
  1970 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1971 context.  Top-level ML bindings are stored within the proof context in
  1972 a purely sequential fashion, disregarding the nested proof structure.
  1973 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1974 proof.  (Requires Poly/ML 5.2 or later.)
  1975 
  1976 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1977 and Method.setup, as well as Isar commands 'attribute_setup' and
  1978 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1979 existing code accordingly, or use plain 'setup' together with old
  1980 Method.add_method.
  1981 
  1982 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1983 to 'a -> thm, while results are always tagged with an authentic oracle
  1984 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1985 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1986 accordingly.  Note that extra performance may be gained by producing
  1987 the cterm carefully, avoiding slow Thm.cterm_of.
  1988 
  1989 * Simplified interface for defining document antiquotations via
  1990 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1991 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1992 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1993 examples.
  1994 
  1995 * More systematic treatment of long names, abstract name bindings, and
  1996 name space operations.  Basic operations on qualified names have been
  1997 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1998 Long_Name.append.  Old type bstring has been mostly replaced by
  1999 abstract type binding (see structure Binding), which supports precise
  2000 qualification by packages and local theory targets, as well as proper
  2001 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2002 bstring values into Binding.name, or better pass through abstract
  2003 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2004 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2005 
  2006 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2007 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2008 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2009 
  2010 * Disposed old type and term read functions (Sign.read_def_typ,
  2011 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2012 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2013 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2014 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2015 resort for legacy applications.
  2016 
  2017 * Disposed old declarations, tactics, tactic combinators that refer to
  2018 the simpset or claset of an implicit theory (such as Addsimps,
  2019 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2020 embedded ML text, or local_simpset_of with a proper context passed as
  2021 explicit runtime argument.
  2022 
  2023 * Rules and tactics that read instantiations (read_instantiate,
  2024 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2025 context, which is required for parsing and type-checking.  Moreover,
  2026 the variables are specified as plain indexnames, not string encodings
  2027 thereof.  INCOMPATIBILITY.
  2028 
  2029 * Generic Toplevel.add_hook interface allows to analyze the result of
  2030 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2031 for theorem dependency output of transactions resulting in a new
  2032 theory state.
  2033 
  2034 * ML antiquotations: block-structured compilation context indicated by
  2035 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2036 
  2037   @{binding name}                         - basic name binding
  2038   @{let ?pat = term}                      - term abbreviation (HO matching)
  2039   @{note name = fact}                     - fact abbreviation
  2040   @{thm fact}                             - singleton fact (with attributes)
  2041   @{thms fact}                            - general fact (with attributes)
  2042   @{lemma prop by method}                 - singleton goal
  2043   @{lemma prop by meth1 meth2}            - singleton goal
  2044   @{lemma prop1 ... propN by method}      - general goal
  2045   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2046   @{lemma (open) ...}                     - open derivation
  2047 
  2048 
  2049 *** System ***
  2050 
  2051 * The Isabelle "emacs" tool provides a specific interface to invoke
  2052 Proof General / Emacs, with more explicit failure if that is not
  2053 installed (the old isabelle-interface script silently falls back on
  2054 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2055 installation location of the Proof General distribution.
  2056 
  2057 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2058 the Isabelle process into a JVM/Scala application.  See
  2059 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2060 process wrapper has been discontinued.)
  2061 
  2062 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2063 
  2064 * Various status messages (with exact source position information) are
  2065 emitted, if proper markup print mode is enabled.  This allows
  2066 user-interface components to provide detailed feedback on internal
  2067 prover operations.
  2068 
  2069 
  2070 
  2071 New in Isabelle2008 (June 2008)
  2072 -------------------------------
  2073 
  2074 *** General ***
  2075 
  2076 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2077 and updated, with formally checked references as hyperlinks.
  2078 
  2079 * Theory loader: use_thy (and similar operations) no longer set the
  2080 implicit ML context, which was occasionally hard to predict and in
  2081 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2082 provides a proper context already.
  2083 
  2084 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2085 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2086 'use' within a theory file will do the job.
  2087 
  2088 * Name space merge now observes canonical order, i.e. the second space
  2089 is inserted into the first one, while existing entries in the first
  2090 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2091 swap theory imports.
  2092 
  2093 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2094 INCOMPATIBILITY in identifier syntax etc.
  2095 
  2096 * Outer syntax: string tokens no longer admit escaped white space,
  2097 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2098 white space without escapes.
  2099 
  2100 * Outer syntax: string tokens may contain arbitrary character codes
  2101 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2102 "foo_bar".
  2103 
  2104 
  2105 *** Pure ***
  2106 
  2107 * Context-dependent token translations.  Default setup reverts locally
  2108 fixed variables, and adds hilite markup for undeclared frees.
  2109 
  2110 * Unused theorems can be found using the new command 'unused_thms'.
  2111 There are three ways of invoking it:
  2112 
  2113 (1) unused_thms
  2114      Only finds unused theorems in the current theory.
  2115 
  2116 (2) unused_thms thy_1 ... thy_n -
  2117      Finds unused theorems in the current theory and all of its ancestors,
  2118      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2119 
  2120 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2121      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2122      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2123      their ancestors.
  2124 
  2125 In order to increase the readability of the list produced by
  2126 unused_thms, theorems that have been created by a particular instance
  2127 of a theory command such as 'inductive' or 'function' are considered
  2128 to belong to the same "group", meaning that if at least one theorem in
  2129 this group is used, the other theorems in the same group are no longer
  2130 reported as unused.  Moreover, if all theorems in the group are
  2131 unused, only one theorem in the group is displayed.
  2132 
  2133 Note that proof objects have to be switched on in order for
  2134 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2135 usually the case when using Proof General with the default settings).
  2136 
  2137 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2138 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2139 duplicate fact bindings, or even accidental fact duplications.  Note
  2140 that tools may maintain dynamically scoped facts systematically, using
  2141 PureThy.add_thms_dynamic.
  2142 
  2143 * Command 'hide' now allows to hide from "fact" name space as well.
  2144 
  2145 * Eliminated destructive theorem database, simpset, claset, and
  2146 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2147 update of theories within ML code.
  2148 
  2149 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2150 INCOMPATIBILITY, object-logics depending on former Pure require
  2151 additional setup PureThy.old_appl_syntax_setup; object-logics
  2152 depending on former CPure need to refer to Pure.
  2153 
  2154 * Commands 'use' and 'ML' are now purely functional, operating on
  2155 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2156 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2157 INCOMPATIBILITY.
  2158 
  2159 * Command 'setup': discontinued implicit version with ML reference.
  2160 
  2161 * Instantiation target allows for simultaneous specification of class
  2162 instance operations together with an instantiation proof.
  2163 Type-checking phase allows to refer to class operations uniformly.
  2164 See src/HOL/Complex/Complex.thy for an Isar example and
  2165 src/HOL/Library/Eval.thy for an ML example.
  2166 
  2167 * Indexing of literal facts: be more serious about including only
  2168 facts from the visible specification/proof context, but not the
  2169 background context (locale etc.).  Affects `prop` notation and method
  2170 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2171 situations.
  2172 
  2173 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2174 "(open)" option, which used to expose internal bound variables to the
  2175 proof text.
  2176 
  2177 * Isar statements: removed obsolete case "rule_context".
  2178 INCOMPATIBILITY, better use explicit fixes/assumes.
  2179 
  2180 * Locale proofs: default proof step now includes 'unfold_locales';
  2181 hence 'proof' without argument may be used to unfold locale
  2182 predicates.
  2183 
  2184 
  2185 *** Document preparation ***
  2186 
  2187 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2188 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2189 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2190 spot); renamed link color from "darkblue" to "linkcolor" (default
  2191 value unchanged, can be redefined via \definecolor); no longer sets
  2192 "a4paper" option (unnecessary or even intrusive).
  2193 
  2194 * Antiquotation @{lemma A method} proves proposition A by the given
  2195 method (either a method name or a method name plus (optional) method
  2196 arguments in parentheses) and prints A just like @{prop A}.
  2197 
  2198 
  2199 *** HOL ***
  2200 
  2201 * New primrec package.  Specification syntax conforms in style to
  2202 definition/function/....  No separate induction rule is provided.  The
  2203 "primrec" command distinguishes old-style and new-style specifications
  2204 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2205 When adjusting theories, beware: constants stemming from new-style
  2206 primrec specifications have authentic syntax.
  2207 
  2208 * Metis prover is now an order of magnitude faster, and also works
  2209 with multithreading.
  2210 
  2211 * Metis: the maximum number of clauses that can be produced from a
  2212 theorem is now given by the attribute max_clauses.  Theorems that
  2213 exceed this number are ignored, with a warning printed.
  2214 
  2215 * Sledgehammer no longer produces structured proofs by default. To
  2216 enable, declare [[sledgehammer_full = true]].  Attributes
  2217 reconstruction_modulus, reconstruction_sorts renamed
  2218 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2219 
  2220 * Method "induct_scheme" derives user-specified induction rules
  2221 from well-founded induction and completeness of patterns. This factors
  2222 out some operations that are done internally by the function package
  2223 and makes them available separately.  See
  2224 src/HOL/ex/Induction_Scheme.thy for examples.
  2225 
  2226 * More flexible generation of measure functions for termination
  2227 proofs: Measure functions can be declared by proving a rule of the
  2228 form "is_measure f" and giving it the [measure_function] attribute.
  2229 The "is_measure" predicate is logically meaningless (always true), and
  2230 just guides the heuristic.  To find suitable measure functions, the
  2231 termination prover sets up the goal "is_measure ?f" of the appropriate
  2232 type and generates all solutions by prolog-style backwards proof using
  2233 the declared rules.
  2234 
  2235 This setup also deals with rules like 
  2236 
  2237   "is_measure f ==> is_measure (list_size f)"
  2238 
  2239 which accommodates nested datatypes that recurse through lists.
  2240 Similar rules are predeclared for products and option types.
  2241 
  2242 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2243 
  2244   INCOMPATIBILITIES:
  2245 
  2246   - Definitions of overloaded constants on sets have to be replaced by
  2247     definitions on => and bool.
  2248 
  2249   - Some definitions of overloaded operators on sets can now be proved
  2250     using the definitions of the operators on => and bool.  Therefore,
  2251     the following theorems have been renamed:
  2252 
  2253       subset_def   -> subset_eq
  2254       psubset_def  -> psubset_eq
  2255       set_diff_def -> set_diff_eq
  2256       Compl_def    -> Compl_eq
  2257       Sup_set_def  -> Sup_set_eq
  2258       Inf_set_def  -> Inf_set_eq
  2259       sup_set_def  -> sup_set_eq
  2260       inf_set_def  -> inf_set_eq
  2261 
  2262   - Due to the incompleteness of the HO unification algorithm, some
  2263     rules such as subst may require manual instantiation, if some of
  2264     the unknowns in the rule is a set.
  2265 
  2266   - Higher order unification and forward proofs:
  2267     The proof pattern
  2268 
  2269       have "P (S::'a set)" <...>
  2270       then have "EX S. P S" ..
  2271 
  2272     no longer works (due to the incompleteness of the HO unification
  2273     algorithm) and must be replaced by the pattern
  2274 
  2275       have "EX S. P S"
  2276       proof
  2277         show "P S" <...>
  2278       qed
  2279 
  2280   - Calculational reasoning with subst (or similar rules):
  2281     The proof pattern
  2282 
  2283       have "P (S::'a set)" <...>
  2284       also have "S = T" <...>
  2285       finally have "P T" .
  2286 
  2287     no longer works (for similar reasons as the previous example) and
  2288     must be replaced by something like
  2289 
  2290       have "P (S::'a set)" <...>
  2291       moreover have "S = T" <...>
  2292       ultimately have "P T" by simp
  2293 
  2294   - Tactics or packages written in ML code:
  2295     Code performing pattern matching on types via
  2296 
  2297       Type ("set", [T]) => ...
  2298 
  2299     must be rewritten. Moreover, functions like strip_type or
  2300     binder_types no longer return the right value when applied to a
  2301     type of the form
  2302 
  2303       T1 => ... => Tn => U => bool
  2304 
  2305     rather than
  2306 
  2307       T1 => ... => Tn => U set
  2308 
  2309 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2310 Wellfounded_Relations to theory Wellfounded.
  2311 
  2312 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2313 
  2314 * Class finite no longer treats UNIV as class parameter.  Use class
  2315 enum from theory Library/Enum instead to achieve a similar effect.
  2316 INCOMPATIBILITY.
  2317 
  2318 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2319 and "Cons".  INCOMPATIBILITY.
  2320 
  2321 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2322 Potential INCOMPATIBILITY.
  2323 
  2324 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2325 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2326 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2327 
  2328 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2329 the same name in theory Orderings:
  2330 
  2331   less_trans
  2332   less_linear
  2333   le_imp_less_or_eq
  2334   le_less_trans
  2335   less_le_trans
  2336   less_not_sym
  2337   less_asym
  2338 
  2339 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2340 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2341 and different variable names.
  2342 
  2343 * Library/Option_ord.thy: Canonical order on option type.
  2344 
  2345 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2346 finite maps.
  2347 
  2348 * Library/Countable.thy: Type class for countable types.
  2349 
  2350 * Theory Int: The representation of numerals has changed.  The infix
  2351 operator BIT and the bit datatype with constructors B0 and B1 have
  2352 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2353 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2354 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2355 accordingly.
  2356 
  2357 * Theory Nat: definition of <= and < on natural numbers no longer
  2358 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2359 le_def and less_def have disappeared.  Consider lemmas not_less
  2360 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2361 
  2362 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2363 (whose purpose mainly is for various fold_set functionals) have been
  2364 abandoned in favor of the existing algebraic classes
  2365 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2366 lower_semilattice (resp. upper_semilattice) and linorder.
  2367 INCOMPATIBILITY.
  2368 
  2369 * Theory Transitive_Closure: induct and cases rules now declare proper
  2370 case_names ("base" and "step").  INCOMPATIBILITY.
  2371 
  2372 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2373 lattices.  The form set-specific version is available as
  2374 Inductive.lfp_ordinal_induct_set.
  2375 
  2376 * Renamed theorems "power.simps" to "power_int.simps".
  2377 INCOMPATIBILITY.
  2378 
  2379 * Class semiring_div provides basic abstract properties of semirings
  2380 with division and modulo operations.  Subsumes former class dvd_mod.
  2381 
  2382 * Merged theories IntDef, Numeral and IntArith into unified theory
  2383 Int.  INCOMPATIBILITY.
  2384 
  2385 * Theory Library/Code_Index: type "index" now represents natural
  2386 numbers rather than integers.  INCOMPATIBILITY.
  2387 
  2388 * New class "uminus" with operation "uminus" (split of from class
  2389 "minus" which now only has operation "minus", binary).
  2390 INCOMPATIBILITY.
  2391 
  2392 * Constants "card", "internal_split", "option_map" now with authentic
  2393 syntax.  INCOMPATIBILITY.
  2394 
  2395 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2396 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2397 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2398 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2399 Sup_set_def, le_def, less_def, option_map_def now with object
  2400 equality.  INCOMPATIBILITY.
  2401 
  2402 * Records. Removed K_record, and replaced it by pure lambda term
  2403 %x. c. The simplifier setup is now more robust against eta expansion.
  2404 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2405 
  2406 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2407 
  2408 * Library/ListVector: new theory of arithmetic vector operations.
  2409 
  2410 * Library/Order_Relation: new theory of various orderings as sets of
  2411 pairs.  Defines preorders, partial orders, linear orders and
  2412 well-orders on sets and on types.
  2413 
  2414 
  2415 *** ZF ***
  2416 
  2417 * Renamed some theories to allow to loading both ZF and HOL in the
  2418 same session:
  2419 
  2420   Datatype  -> Datatype_ZF
  2421   Inductive -> Inductive_ZF
  2422   Int       -> Int_ZF
  2423   IntDiv    -> IntDiv_ZF
  2424   Nat       -> Nat_ZF
  2425   List      -> List_ZF
  2426   Main      -> Main_ZF
  2427 
  2428 INCOMPATIBILITY: ZF theories that import individual theories below
  2429 Main might need to be adapted.  Regular theory Main is still
  2430 available, as trivial extension of Main_ZF.
  2431 
  2432 
  2433 *** ML ***
  2434 
  2435 * ML within Isar: antiquotation @{const name} or @{const
  2436 name(typargs)} produces statically-checked Const term.
  2437 
  2438 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2439 (of the same name).  Removed obsolete print command.
  2440 
  2441 * Removed obsolete "use_legacy_bindings" function.
  2442 
  2443 * The ``print mode'' is now a thread-local value derived from a global
  2444 template (the former print_mode reference), thus access becomes
  2445 non-critical.  The global print_mode reference is for session
  2446 management only; user-code should use print_mode_value,
  2447 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2448 
  2449 * Functions system/system_out provide a robust way to invoke external
  2450 shell commands, with propagation of interrupts (requires Poly/ML
  2451 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2452 
  2453 
  2454 *** System ***
  2455 
  2456 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2457 in accordance with Proof General 3.7, which prefers GNU emacs.
  2458 
  2459 * isatool tty runs Isabelle process with plain tty interaction;
  2460 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2461 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2462 
  2463 * isatool browser now works with Cygwin as well, using general
  2464 "javapath" function defined in Isabelle process environment.
  2465 
  2466 * YXML notation provides a simple and efficient alternative to
  2467 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2468 isatool yxml as described in the Isabelle system manual.
  2469 
  2470 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2471 provides general wrapper for managing an Isabelle process in a robust
  2472 fashion, with ``cooked'' output from stdin/stderr.
  2473 
  2474 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2475 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2476 
  2477 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2478 way of changing the user's settings is via
  2479 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2480 script.
  2481 
  2482 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2483 cores of the underlying machine, which is a good starting point for
  2484 optimal performance tuning.  The corresponding usedir option -M allows
  2485 "max" as an alias for "0".  WARNING: does not work on certain versions
  2486 of Mac OS (with Poly/ML 5.1).
  2487 
  2488 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2489 adverse effect of Isabelle flooding interactive front-ends (notably
  2490 ProofGeneral / XEmacs).
  2491 
  2492 
  2493 
  2494 New in Isabelle2007 (November 2007)
  2495 -----------------------------------
  2496 
  2497 *** General ***
  2498 
  2499 * More uniform information about legacy features, notably a
  2500 warning/error of "Legacy feature: ...", depending on the state of the
  2501 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2502 legacy features will disappear eventually.
  2503 
  2504 * Theory syntax: the header format ``theory A = B + C:'' has been
  2505 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2506 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2507 
  2508 * Theory syntax: the old non-Isar theory file format has been
  2509 discontinued altogether.  Note that ML proof scripts may still be used
  2510 with Isar theories; migration is usually quite simple with the ML
  2511 function use_legacy_bindings.  INCOMPATIBILITY.
  2512 
  2513 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2514 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2515 quotes.
  2516 
  2517 * Theory loader: be more serious about observing the static theory
  2518 header specifications (including optional directories), but not the
  2519 accidental file locations of previously successful loads.  The strict
  2520 update policy of former update_thy is now already performed by
  2521 use_thy, so the former has been removed; use_thys updates several
  2522 theories simultaneously, just as 'imports' within a theory header
  2523 specification, but without merging the results.  Potential
  2524 INCOMPATIBILITY: may need to refine theory headers and commands
  2525 ROOT.ML which depend on load order.
  2526 
  2527 * Theory loader: optional support for content-based file
  2528 identification, instead of the traditional scheme of full physical
  2529 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2530 (cf. the system manual).  The new scheme allows to work with
  2531 non-finished theories in persistent session images, such that source
  2532 files may be moved later on without requiring reloads.
  2533 
  2534 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2535 file (with the same base name as the theory) are considered a legacy
  2536 feature, which will disappear eventually. Even now, the theory loader
  2537 no longer maintains dependencies on such files.
  2538 
  2539 * Syntax: the scope for resolving ambiguities via type-inference is
  2540 now limited to individual terms, instead of whole simultaneous
  2541 specifications as before. This greatly reduces the complexity of the
  2542 syntax module and improves flexibility by separating parsing and
  2543 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2544 'fixes' etc.) are required in rare situations.
  2545 
  2546 * Syntax: constants introduced by new-style packages ('definition',
  2547 'abbreviation' etc.) are passed through the syntax module in
  2548 ``authentic mode''. This means that associated mixfix annotations
  2549 really stick to such constants, independently of potential name space
  2550 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2551 trees are represented slightly differently, may need to adapt syntax
  2552 translations accordingly. Use CONST marker in 'translations' and
  2553 @{const_syntax} antiquotation in 'parse_translation' etc.
  2554 
  2555 * Legacy goal package: reduced interface to the bare minimum required
  2556 to keep existing proof scripts running.  Most other user-level
  2557 functions are now part of the OldGoals structure, which is *not* open
  2558 by default (consider isatool expandshort before open OldGoals).
  2559 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2560 these tend to cause confusion about the actual goal (!) context being
  2561 used here, which is not necessarily the same as the_context().
  2562 
  2563 * Command 'find_theorems': supports "*" wild-card in "name:"
  2564 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2565 support a specific search form (see ProofGeneral/CHANGES).
  2566 
  2567 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2568 by default, which means that "prems" (and also "fixed variables") are
  2569 suppressed from proof state output.  Note that the ProofGeneral
  2570 settings mechanism allows to change and save options persistently, but
  2571 older versions of Isabelle will fail to start up if a negative prems
  2572 limit is imposed.
  2573 
  2574 * Local theory targets may be specified by non-nested blocks of
  2575 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2576 contain definitions, theorems etc., including any derived mechanism
  2577 that has been implemented on top of these primitives.  This concept
  2578 generalizes the existing ``theorem (in ...)'' towards more versatility
  2579 and scalability.
  2580 
  2581 * Proof General interface: proper undo of final 'end' command;
  2582 discontinued Isabelle/classic mode (ML proof scripts).
  2583 
  2584 
  2585 *** Document preparation ***
  2586 
  2587 * Added antiquotation @{theory name} which prints the given name,
  2588 after checking that it refers to a valid ancestor theory in the
  2589 current context.
  2590 
  2591 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2592 check the given source text as ML type/structure, printing verbatim.
  2593 
  2594 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2595 "c args == rhs" given in the current context.  (Any number of
  2596 arguments may be given on the LHS.)
  2597 
  2598 
  2599 *** Pure ***
  2600 
  2601 * The 'class' package offers a combination of axclass and locale to
  2602 achieve Haskell-like type classes in Isabelle.  Definitions and
  2603 theorems within a class context produce both relative results (with
  2604 implicit parameters according to the locale context), and polymorphic
  2605 constants with qualified polymorphism (according to the class
  2606 context).  Within the body context of a 'class' target, a separate
  2607 syntax layer ("user space type system") takes care of converting
  2608 between global polymorphic consts and internal locale representation.
  2609 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2610 "isatool doc classes" provides a tutorial.
  2611 
  2612 * Generic code generator framework allows to generate executable
  2613 code for ML and Haskell (including Isabelle classes).  A short usage
  2614 sketch:
  2615 
  2616     internal compilation:
  2617         export_code <list of constants (term syntax)> in SML
  2618     writing SML code to a file:
  2619         export_code <list of constants (term syntax)> in SML <filename>
  2620     writing OCaml code to a file:
  2621         export_code <list of constants (term syntax)> in OCaml <filename>
  2622     writing Haskell code to a bunch of files:
  2623         export_code <list of constants (term syntax)> in Haskell <filename>
  2624 
  2625     evaluating closed propositions to True/False using code generation:
  2626         method ``eval''
  2627 
  2628 Reasonable default setup of framework in HOL.
  2629 
  2630 Theorem attributs for selecting and transforming function equations theorems:
  2631 
  2632     [code fun]:        select a theorem as function equation for a specific constant
  2633     [code fun del]:    deselect a theorem as function equation for a specific constant
  2634     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2635     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2636 
  2637 User-defined serializations (target in {SML, OCaml, Haskell}):
  2638 
  2639     code_const <and-list of constants (term syntax)>
  2640       {(target) <and-list of const target syntax>}+
  2641 
  2642     code_type <and-list of type constructors>
  2643       {(target) <and-list of type target syntax>}+
  2644 
  2645     code_instance <and-list of instances>
  2646       {(target)}+
  2647         where instance ::= <type constructor> :: <class>
  2648 
  2649     code_class <and_list of classes>
  2650       {(target) <and-list of class target syntax>}+
  2651         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2652 
  2653 code_instance and code_class only are effective to target Haskell.
  2654 
  2655 For example usage see src/HOL/ex/Codegenerator.thy and
  2656 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2657 generation from Isabelle/HOL theories is available via "isatool doc
  2658 codegen".
  2659 
  2660 * Code generator: consts in 'consts_code' Isar commands are now
  2661 referred to by usual term syntax (including optional type
  2662 annotations).
  2663 
  2664 * Command 'no_translations' removes translation rules from theory
  2665 syntax.
  2666 
  2667 * Overloaded definitions are now actually checked for acyclic
  2668 dependencies.  The overloading scheme is slightly more general than
  2669 that of Haskell98, although Isabelle does not demand an exact
  2670 correspondence to type class and instance declarations.
  2671 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2672 exotic versions of overloading -- at the discretion of the user!
  2673 
  2674 Polymorphic constants are represented via type arguments, i.e. the
  2675 instantiation that matches an instance against the most general
  2676 declaration given in the signature.  For example, with the declaration
  2677 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2678 as c(nat).  Overloading is essentially simultaneous structural
  2679 recursion over such type arguments.  Incomplete specification patterns
  2680 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2681 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2682 Command 'print_theory' outputs the normalized system of recursive
  2683 equations, see section "definitions".
  2684 
  2685 * Configuration options are maintained within the theory or proof
  2686 context (with name and type bool/int/string), providing a very simple
  2687 interface to a poor-man's version of general context data.  Tools may
  2688 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2689 these values using Config.get etc.  Users may change options via an
  2690 associated attribute of the same name.  This form of context
  2691 declaration works particularly well with commands 'declare' or
  2692 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2693 very easy to avoid global references, which would not observe Isar
  2694 toplevel undo/redo and fail to work with multithreading.
  2695 
  2696 Various global ML references of Pure and HOL have been turned into
  2697 configuration options:
  2698 
  2699   Unify.search_bound		unify_search_bound
  2700   Unify.trace_bound		unify_trace_bound
  2701   Unify.trace_simp		unify_trace_simp
  2702   Unify.trace_types		unify_trace_types
  2703   Simplifier.simp_depth_limit	simp_depth_limit
  2704   Blast.depth_limit		blast_depth_limit
  2705   DatatypeProp.dtK		datatype_distinctness_limit
  2706   fast_arith_neq_limit  	fast_arith_neq_limit
  2707   fast_arith_split_limit	fast_arith_split_limit
  2708 
  2709 * Named collections of theorems may be easily installed as context
  2710 data using the functor NamedThmsFun (see also
  2711 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2712 attributes; there is also a toplevel print command.  This facility is
  2713 just a common case of general context data, which is the preferred way
  2714 for anything more complex than just a list of facts in canonical
  2715 order.
  2716 
  2717 * Isar: command 'declaration' augments a local theory by generic
  2718 declaration functions written in ML.  This enables arbitrary content
  2719 being added to the context, depending on a morphism that tells the
  2720 difference of the original declaration context wrt. the application
  2721 context encountered later on.
  2722 
  2723 * Isar: proper interfaces for simplification procedures.  Command
  2724 'simproc_setup' declares named simprocs (with match patterns, and body
  2725 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2726 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2727 
  2728 * Isar: an extra pair of brackets around attribute declarations
  2729 abbreviates a theorem reference involving an internal dummy fact,
  2730 which will be ignored later --- only the effect of the attribute on
  2731 the background context will persist.  This form of in-place
  2732 declarations is particularly useful with commands like 'declare' and
  2733 'using', for example ``have A using [[simproc a]] by simp''.
  2734 
  2735 * Isar: method "assumption" (and implicit closing of subproofs) now
  2736 takes simple non-atomic goal assumptions into account: after applying
  2737 an assumption as a rule the resulting subgoals are solved by atomic
  2738 assumption steps.  This is particularly useful to finish 'obtain'
  2739 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2740 without referring to the original premise "!!x. P x ==> thesis" in the
  2741 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2742 more permissive.
  2743 
  2744 * Isar: implicit use of prems from the Isar proof context is
  2745 considered a legacy feature.  Common applications like ``have A .''
  2746 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2747 referencing facts explicitly here improves readability and
  2748 maintainability of proof texts.
  2749 
  2750 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2751 the obtained context from the course of reasoning!  For example:
  2752 
  2753   assume "EX x y. A x & B y"   -- "any previous fact"
  2754   then guess x and y by clarify
  2755 
  2756 This technique is potentially adventurous, depending on the facts and
  2757 proof tools being involved here.
  2758 
  2759 * Isar: known facts from the proof context may be specified as literal
  2760 propositions, using ASCII back-quote syntax.  This works wherever
  2761 named facts used to be allowed so far, in proof commands, proof
  2762 methods, attributes etc.  Literal facts are retrieved from the context
  2763 according to unification of type and term parameters.  For example,
  2764 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2765 theorems in the current context, then these are valid literal facts:
  2766 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2767 
  2768 There is also a proof method "fact" which does the same composition
  2769 for explicit goal states, e.g. the following proof texts coincide with
  2770 certain special cases of literal facts:
  2771 
  2772   have "A" by fact                 ==  note `A`
  2773   have "A ==> B" by fact           ==  note `A ==> B`
  2774   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2775   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2776 
  2777 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2778 outer syntax.  Thus symbolic identifiers may be used without
  2779 additional white space in declarations like this: ``assume *: A''.
  2780 
  2781 * Isar: 'print_facts' prints all local facts of the current context,
  2782 both named and unnamed ones.
  2783 
  2784 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2785 
  2786   def x == "t" and y == "u"
  2787 
  2788 * Isar: added command 'unfolding', which is structurally similar to
  2789 'using', but affects both the goal state and facts by unfolding given
  2790 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2791 'unfolded' attribute may be replaced by first-class proof text.
  2792 
  2793 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2794 and command 'unfolding' now all support object-level equalities
  2795 (potentially conditional).  The underlying notion of rewrite rule is
  2796 analogous to the 'rule_format' attribute, but *not* that of the
  2797 Simplifier (which is usually more generous).
  2798 
  2799 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2800 premises of a theorem by n. Useful in conjunction with drule.
  2801 
  2802 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2803 method expression within a sandbox consisting of the first N
  2804 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2805 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2806 simplifies all new goals that emerge from applying rule foo to the
  2807 originally first one.
  2808 
  2809 * Isar: schematic goals are no longer restricted to higher-order
  2810 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2811 expected.
  2812 
  2813 * Isar: the conclusion of a long theorem statement is now either
  2814 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2815 (essentially a disjunction of cases with local parameters and
  2816 assumptions).  The latter allows to express general elimination rules
  2817 adequately; in this notation common elimination rules look like this:
  2818 
  2819   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2820     assumes "EX x. P x"
  2821     obtains x where "P x"
  2822 
  2823   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2824     assumes "A & B"
  2825     obtains A and B
  2826 
  2827   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2828     assumes "A | B"
  2829     obtains
  2830       A
  2831     | B
  2832 
  2833 The subsequent classical rules even refer to the formal "thesis"
  2834 explicitly:
  2835 
  2836   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2837     obtains "~ thesis"
  2838 
  2839   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2840     obtains "thesis ==> something"
  2841 
  2842 The actual proof of an 'obtains' statement is analogous to that of the
  2843 Isar proof element 'obtain', only that there may be several cases.
  2844 Optional case names may be specified in parentheses; these will be
  2845 available both in the present proof and as annotations in the
  2846 resulting rule, for later use with the 'cases' method (cf. attribute
  2847 case_names).
  2848 
  2849 * Isar: the assumptions of a long theorem statement are available as
  2850 "assms" fact in the proof context.  This is more appropriate than the
  2851 (historical) "prems", which refers to all assumptions of the current
  2852 context, including those from the target locale, proof body etc.
  2853 
  2854 * Isar: 'print_statement' prints theorems from the current theory or
  2855 proof context in long statement form, according to the syntax of a
  2856 top-level lemma.
  2857 
  2858 * Isar: 'obtain' takes an optional case name for the local context
  2859 introduction rule (default "that").
  2860 
  2861 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2862 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2863 to occur.
  2864 
  2865 * Pure: syntax "CONST name" produces a fully internalized constant
  2866 according to the current context.  This is particularly useful for
  2867 syntax translations that should refer to internal constant
  2868 representations independently of name spaces.
  2869 
  2870 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2871 instead of "FOO ". This allows multiple binder declarations to coexist
  2872 in the same context.  INCOMPATIBILITY.
  2873 
  2874 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2875 primitive that also works in a locale context (both for constants and
  2876 fixed variables). Type declaration and internal syntactic representation
  2877 of given constants retrieved from the context. Likewise, the
  2878 'no_notation' command allows to remove given syntax annotations from the
  2879 current context.
  2880 
  2881 * Isar/locales: new derived specification elements 'axiomatization',
  2882 'definition', 'abbreviation', which support type-inference, admit
  2883 object-level specifications (equality, equivalence).  See also the
  2884 isar-ref manual.  Examples:
  2885 
  2886   axiomatization
  2887     eq  (infix "===" 50) where
  2888     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2889 
  2890   definition "f x y = x + y + 1"
  2891   definition g where "g x = f x x"
  2892 
  2893   abbreviation
  2894     neq  (infix "=!=" 50) where
  2895     "x =!= y == ~ (x === y)"
  2896 
  2897 These specifications may be also used in a locale context.  Then the
  2898 constants being introduced depend on certain fixed parameters, and the
  2899 constant name is qualified by the locale base name.  An internal
  2900 abbreviation takes care for convenient input and output, making the
  2901 parameters implicit and using the original short name.  See also
  2902 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2903 entities from a monomorphic theory.
  2904 
  2905 Presently, abbreviations are only available 'in' a target locale, but
  2906 not inherited by general import expressions.  Also note that
  2907 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2908 'translations' in common applications.  The "no_abbrevs" print mode
  2909 prevents folding of abbreviations in term output.
  2910 
  2911 Concrete syntax is attached to specified constants in internal form,
  2912 independently of name spaces.  The parse tree representation is
  2913 slightly different -- use 'notation' instead of raw 'syntax', and
  2914 'translations' with explicit "CONST" markup to accommodate this.
  2915 
  2916 * Pure/Isar: unified syntax for new-style specification mechanisms
  2917 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2918 full type inference and dummy patterns ("_").  For example:
  2919 
  2920   definition "K x _ = x"
  2921 
  2922   inductive conj for A B
  2923   where "A ==> B ==> conj A B"
  2924 
  2925 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2926 the current context.  Print mode "no_abbrevs" prevents inversion of
  2927 abbreviations on output.
  2928 
  2929 * Isar/locales: improved parameter handling: use of locales "var" and
  2930 "struct" no longer necessary; - parameter renamings are no longer
  2931 required to be injective.  For example, this allows to define
  2932 endomorphisms as locale endom = homom mult mult h.
  2933 
  2934 * Isar/locales: changed the way locales with predicates are defined.
  2935 Instead of accumulating the specification, the imported expression is
  2936 now an interpretation.  INCOMPATIBILITY: different normal form of
  2937 locale expressions.  In particular, in interpretations of locales with
  2938 predicates, goals repesenting already interpreted fragments are not
  2939 removed automatically.  Use methods `intro_locales' and
  2940 `unfold_locales'; see below.
  2941 
  2942 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2943 provide backward reasoning on locales predicates.  The methods are
  2944 aware of interpretations and discharge corresponding goals.
  2945 `intro_locales' is less aggressive then `unfold_locales' and does not
  2946 unfold predicates to assumptions.
  2947 
  2948 * Isar/locales: the order in which locale fragments are accumulated
  2949 has changed.  This enables to override declarations from fragments due
  2950 to interpretations -- for example, unwanted simp rules.
  2951 
  2952 * Isar/locales: interpretation in theories and proof contexts has been
  2953 extended.  One may now specify (and prove) equations, which are
  2954 unfolded in interpreted theorems.  This is useful for replacing
  2955 defined concepts (constants depending on locale parameters) by
  2956 concepts already existing in the target context.  Example:
  2957 
  2958   interpretation partial_order ["op <= :: [int, int] => bool"]
  2959     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2960 
  2961 Typically, the constant `partial_order.less' is created by a
  2962 definition specification element in the context of locale
  2963 partial_order.
  2964 
  2965 * Method "induct": improved internal context management to support
  2966 local fixes and defines on-the-fly. Thus explicit meta-level
  2967 connectives !!  and ==> are rarely required anymore in inductive goals
  2968 (using object-logic connectives for this purpose has been long
  2969 obsolete anyway). Common proof patterns are explained in
  2970 src/HOL/Induct/Common_Patterns.thy, see also
  2971 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2972 examples.
  2973 
  2974 * Method "induct": improved handling of simultaneous goals. Instead of
  2975 introducing object-level conjunction, the statement is now split into
  2976 several conclusions, while the corresponding symbolic cases are nested
  2977 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2978 see src/HOL/Induct/Common_Patterns.thy, for example.
  2979 
  2980 * Method "induct": mutual induction rules are now specified as a list
  2981 of rule sharing the same induction cases. HOL packages usually provide
  2982 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2983 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2984 mutual induction rules differently, i.e. like this:
  2985 
  2986   (induct rule: foo_bar.inducts)
  2987   (induct set: foo bar)
  2988   (induct pred: foo bar)
  2989   (induct type: foo bar)
  2990 
  2991 The ML function ProjectRule.projections turns old-style rules into the
  2992 new format.
  2993 
  2994 * Method "coinduct": dual of induction, see
  2995 src/HOL/Library/Coinductive_List.thy for various examples.
  2996 
  2997 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2998 considered a legacy feature.
  2999 
  3000 * Attribute "symmetric" produces result with standardized schematic
  3001 variables (index 0).  Potential INCOMPATIBILITY.
  3002 
  3003 * Simplifier: by default the simplifier trace only shows top level
  3004 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3005 default. Thus there is less danger of being flooded by the trace. The
  3006 trace indicates where parts have been suppressed.
  3007   
  3008 * Provers/classical: removed obsolete classical version of elim_format
  3009 attribute; classical elim/dest rules are now treated uniformly when
  3010 manipulating the claset.
  3011 
  3012 * Provers/classical: stricter checks to ensure that supplied intro,
  3013 dest and elim rules are well-formed; dest and elim rules must have at
  3014 least one premise.
  3015 
  3016 * Provers/classical: attributes dest/elim/intro take an optional
  3017 weight argument for the rule (just as the Pure versions).  Weights are
  3018 ignored by automated tools, but determine the search order of single
  3019 rule steps.
  3020 
  3021 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3022 where the body does not mention the bound variable.  Note that dummy
  3023 patterns implicitly depend on their context of bounds, which makes
  3024 "{_. _}" match any set comprehension as expected.  Potential
  3025 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3026 constant "_idtdummy" in the binding position.
  3027 
  3028 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3029 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3030 for example "A -> B" => "Pi A (%_. B)".
  3031 
  3032 * Pure: 'class_deps' command visualizes the subclass relation, using
  3033 the graph browser tool.
  3034 
  3035 * Pure: 'print_theory' now suppresses certain internal declarations by
  3036 default; use '!' option for full details.
  3037 
  3038 
  3039 *** HOL ***
  3040 
  3041 * Method "metis" proves goals by applying the Metis general-purpose
  3042 resolution prover (see also http://gilith.com/software/metis/).
  3043 Examples are in the directory MetisExamples.  WARNING: the
  3044 Isabelle/HOL-Metis integration does not yet work properly with
  3045 multi-threading.
  3046   
  3047 * Command 'sledgehammer' invokes external automatic theorem provers as
  3048 background processes.  It generates calls to the "metis" method if
  3049 successful. These can be pasted into the proof.  Users do not have to
  3050 wait for the automatic provers to return.  WARNING: does not really
  3051 work with multi-threading.
  3052 
  3053 * New "auto_quickcheck" feature tests outermost goal statements for
  3054 potential counter-examples.  Controlled by ML references
  3055 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3056 5000 milliseconds).  Fails silently if statements is outside of
  3057 executable fragment, or any other codgenerator problem occurs.
  3058 
  3059 * New constant "undefined" with axiom "undefined x = undefined".
  3060 
  3061 * Added class "HOL.eq", allowing for code generation with polymorphic
  3062 equality.
  3063 
  3064 * Some renaming of class constants due to canonical name prefixing in
  3065 the new 'class' package:
  3066 
  3067     HOL.abs ~> HOL.abs_class.abs
  3068     HOL.divide ~> HOL.divide_class.divide
  3069     0 ~> HOL.zero_class.zero
  3070     1 ~> HOL.one_class.one
  3071     op + ~> HOL.plus_class.plus
  3072     op - ~> HOL.minus_class.minus
  3073     uminus ~> HOL.minus_class.uminus
  3074     op * ~> HOL.times_class.times
  3075     op < ~> HOL.ord_class.less
  3076     op <= > HOL.ord_class.less_eq
  3077     Nat.power ~> Power.power_class.power
  3078     Nat.size ~> Nat.size_class.size
  3079     Numeral.number_of ~> Numeral.number_class.number_of
  3080     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3081     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3082     Orderings.min ~> Orderings.ord_class.min
  3083     Orderings.max ~> Orderings.ord_class.max
  3084     Divides.op div ~> Divides.div_class.div
  3085     Divides.op mod ~> Divides.div_class.mod
  3086     Divides.op dvd ~> Divides.div_class.dvd
  3087 
  3088 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3089 
  3090 a) User-defined constants using any of the names "plus", "minus",
  3091 "times", "less" or "less_eq". The standard syntax translations for
  3092 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3093 names.
  3094 
  3095 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3096 INCOMPATIBILITY: use more specific names.
  3097 
  3098 c) Permutative equations (e.g. "a + b = b + a")
  3099 Since the change of names also changes the order of terms, permutative
  3100 rewrite rules may get applied in a different order. Experience shows
  3101 that this is rarely the case (only two adaptions in the whole Isabelle
  3102 distribution).  INCOMPATIBILITY: rewrite proofs
  3103 
  3104 d) ML code directly refering to constant names
  3105 This in general only affects hand-written proof tactics, simprocs and
  3106 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3107 Consider using @{const_name} antiquotation.
  3108 
  3109 * New class "default" with associated constant "default".
  3110 
  3111 * Function "sgn" is now overloaded and available on int, real, complex
  3112 (and other numeric types), using class "sgn".  Two possible defs of
  3113 sgn are given as equational assumptions in the classes sgn_if and
  3114 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3115 INCOMPATIBILITY.
  3116 
  3117 * Locale "partial_order" now unified with class "order" (cf. theory
  3118 Orderings), added parameter "less".  INCOMPATIBILITY.
  3119 
  3120 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3121 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3122 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3123 
  3124 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3125 changed order of proof goals in instance proofs.
  3126 
  3127 * The transitivity reasoner for partial and linear orders is set up
  3128 for classes "order" and "linorder".  Instances of the reasoner are available
  3129 in all contexts importing or interpreting the corresponding locales.
  3130 Method "order" invokes the reasoner separately; the reasoner
  3131 is also integrated with the Simplifier as a solver.  Diagnostic
  3132 command 'print_orders' shows the available instances of the reasoner
  3133 in the current context.
  3134 
  3135 * Localized monotonicity predicate in theory "Orderings"; integrated
  3136 lemmas max_of_mono and min_of_mono with this predicate.
  3137 INCOMPATIBILITY.
  3138 
  3139 * Formulation of theorem "dense" changed slightly due to integration
  3140 with new class dense_linear_order.
  3141 
  3142 * Uniform lattice theory development in HOL.
  3143 
  3144     constants "meet" and "join" now named "inf" and "sup"
  3145     constant "Meet" now named "Inf"
  3146 
  3147     classes "meet_semilorder" and "join_semilorder" now named
  3148       "lower_semilattice" and "upper_semilattice"
  3149     class "lorder" now named "lattice"
  3150     class "comp_lat" now named "complete_lattice"
  3151 
  3152     Instantiation of lattice classes allows explicit definitions
  3153     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3154 
  3155   INCOMPATIBILITY.  Theorem renames:
  3156 
  3157     meet_left_le            ~> inf_le1
  3158     meet_right_le           ~> inf_le2
  3159     join_left_le            ~> sup_ge1
  3160     join_right_le           ~> sup_ge2
  3161     meet_join_le            ~> inf_sup_ord
  3162     le_meetI                ~> le_infI
  3163     join_leI                ~> le_supI
  3164     le_meet                 ~> le_inf_iff
  3165     le_join                 ~> ge_sup_conv
  3166     meet_idempotent         ~> inf_idem
  3167     join_idempotent         ~> sup_idem
  3168     meet_comm               ~> inf_commute
  3169     join_comm               ~> sup_commute
  3170     meet_leI1               ~> le_infI1
  3171     meet_leI2               ~> le_infI2
  3172     le_joinI1               ~> le_supI1
  3173     le_joinI2               ~> le_supI2
  3174     meet_assoc              ~> inf_assoc
  3175     join_assoc              ~> sup_assoc
  3176     meet_left_comm          ~> inf_left_commute
  3177     meet_left_idempotent    ~> inf_left_idem
  3178     join_left_comm          ~> sup_left_commute
  3179     join_left_idempotent    ~> sup_left_idem
  3180     meet_aci                ~> inf_aci
  3181     join_aci                ~> sup_aci
  3182     le_def_meet             ~> le_iff_inf
  3183     le_def_join             ~> le_iff_sup
  3184     join_absorp2            ~> sup_absorb2
  3185     join_absorp1            ~> sup_absorb1
  3186     meet_absorp1            ~> inf_absorb1
  3187     meet_absorp2            ~> inf_absorb2
  3188     meet_join_absorp        ~> inf_sup_absorb
  3189     join_meet_absorp        ~> sup_inf_absorb
  3190     distrib_join_le         ~> distrib_sup_le
  3191     distrib_meet_le         ~> distrib_inf_le
  3192 
  3193     add_meet_distrib_left   ~> add_inf_distrib_left
  3194     add_join_distrib_left   ~> add_sup_distrib_left
  3195     is_join_neg_meet        ~> is_join_neg_inf
  3196     is_meet_neg_join        ~> is_meet_neg_sup
  3197     add_meet_distrib_right  ~> add_inf_distrib_right
  3198     add_join_distrib_right  ~> add_sup_distrib_right
  3199     add_meet_join_distribs  ~> add_sup_inf_distribs
  3200     join_eq_neg_meet        ~> sup_eq_neg_inf
  3201     meet_eq_neg_join        ~> inf_eq_neg_sup
  3202     add_eq_meet_join        ~> add_eq_inf_sup
  3203     meet_0_imp_0            ~> inf_0_imp_0
  3204     join_0_imp_0            ~> sup_0_imp_0
  3205     meet_0_eq_0             ~> inf_0_eq_0
  3206     join_0_eq_0             ~> sup_0_eq_0
  3207     neg_meet_eq_join        ~> neg_inf_eq_sup
  3208     neg_join_eq_meet        ~> neg_sup_eq_inf
  3209     join_eq_if              ~> sup_eq_if
  3210 
  3211     mono_meet               ~> mono_inf
  3212     mono_join               ~> mono_sup
  3213     meet_bool_eq            ~> inf_bool_eq
  3214     join_bool_eq            ~> sup_bool_eq
  3215     meet_fun_eq             ~> inf_fun_eq
  3216     join_fun_eq             ~> sup_fun_eq
  3217     meet_set_eq             ~> inf_set_eq
  3218     join_set_eq             ~> sup_set_eq
  3219     meet1_iff               ~> inf1_iff
  3220     meet2_iff               ~> inf2_iff
  3221     meet1I                  ~> inf1I
  3222     meet2I                  ~> inf2I
  3223     meet1D1                 ~> inf1D1
  3224     meet2D1                 ~> inf2D1
  3225     meet1D2                 ~> inf1D2
  3226     meet2D2                 ~> inf2D2
  3227     meet1E                  ~> inf1E
  3228     meet2E                  ~> inf2E
  3229     join1_iff               ~> sup1_iff
  3230     join2_iff               ~> sup2_iff
  3231     join1I1                 ~> sup1I1
  3232     join2I1                 ~> sup2I1
  3233     join1I1                 ~> sup1I1
  3234     join2I2                 ~> sup1I2
  3235     join1CI                 ~> sup1CI
  3236     join2CI                 ~> sup2CI
  3237     join1E                  ~> sup1E
  3238     join2E                  ~> sup2E
  3239 
  3240     is_meet_Meet            ~> is_meet_Inf
  3241     Meet_bool_def           ~> Inf_bool_def
  3242     Meet_fun_def            ~> Inf_fun_def
  3243     Meet_greatest           ~> Inf_greatest
  3244     Meet_lower              ~> Inf_lower
  3245     Meet_set_def            ~> Inf_set_def
  3246 
  3247     Sup_def                 ~> Sup_Inf
  3248     Sup_bool_eq             ~> Sup_bool_def
  3249     Sup_fun_eq              ~> Sup_fun_def
  3250     Sup_set_eq              ~> Sup_set_def
  3251 
  3252     listsp_meetI            ~> listsp_infI
  3253     listsp_meet_eq          ~> listsp_inf_eq
  3254 
  3255     meet_min                ~> inf_min
  3256     join_max                ~> sup_max
  3257 
  3258 * Added syntactic class "size"; overloaded constant "size" now has
  3259 type "'a::size ==> bool"
  3260 
  3261 * Internal reorganisation of `size' of datatypes: size theorems
  3262 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3263 simplification rules by default!); theorems "prod.size" now named
  3264 "*.size".
  3265 
  3266 * Class "div" now inherits from class "times" rather than "type".
  3267 INCOMPATIBILITY.
  3268 
  3269 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3270 Linorder etc.  have disappeared; operations defined in terms of
  3271 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3272 
  3273 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3274 
  3275 * HOL-Word: New extensive library and type for generic, fixed size
  3276 machine words, with arithemtic, bit-wise, shifting and rotating
  3277 operations, reflection into int, nat, and bool lists, automation for
  3278 linear arithmetic (by automatic reflection into nat or int), including
  3279 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3280 arithmetic type classes, supporting automatic simplification of
  3281 numerals on all operations.
  3282 
  3283 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3284 
  3285 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3286 
  3287 * Code generator library theories:
  3288   - Code_Integer represents HOL integers by big integer literals in target
  3289     languages.
  3290   - Code_Char represents HOL characters by character literals in target
  3291     languages.
  3292   - Code_Char_chr like Code_Char, but also offers treatment of character
  3293     codes; includes Code_Integer.
  3294   - Executable_Set allows to generate code for finite sets using lists.
  3295   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3296     denominator).
  3297   - Executable_Real implements a subset of real numbers, namly those
  3298     representable by rational numbers.
  3299   - Efficient_Nat implements natural numbers by integers, which in general will
  3300     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3301     includes Code_Integer.
  3302   - Code_Index provides an additional datatype index which is mapped to
  3303     target-language built-in integers.
  3304   - Code_Message provides an additional datatype message_string which is isomorphic to
  3305     strings; messages are mapped to target-language strings.
  3306 
  3307 * New package for inductive predicates
  3308 
  3309   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3310 
  3311     inductive
  3312       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3313       for z_1 :: U_1 and ... and z_n :: U_m
  3314     where
  3315       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3316     | ...
  3317 
  3318   with full support for type-inference, rather than
  3319 
  3320     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3321 
  3322     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3323     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3324 
  3325     inductive "s z_1 ... z_m"
  3326     intros
  3327       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3328       ...
  3329 
  3330   For backward compatibility, there is a wrapper allowing inductive
  3331   sets to be defined with the new package via
  3332 
  3333     inductive_set
  3334       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3335       for z_1 :: U_1 and ... and z_n :: U_m
  3336     where
  3337       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3338     | ...
  3339 
  3340   or
  3341 
  3342     inductive_set
  3343       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3344       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3345       for z_1 :: U_1 and ... and z_n :: U_m
  3346     where
  3347       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3348     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3349     | ...
  3350 
  3351   if the additional syntax "p ..." is required.
  3352 
  3353   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3354   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3355 
  3356   INCOMPATIBILITIES:
  3357 
  3358   - Since declaration and definition of inductive sets or predicates
  3359     is no longer separated, abbreviations involving the newly
  3360     introduced sets or predicates must be specified together with the
  3361     introduction rules after the 'where' keyword (see above), rather
  3362     than before the actual inductive definition.
  3363 
  3364   - The variables in induction and elimination rules are now
  3365     quantified in the order of their occurrence in the introduction
  3366     rules, rather than in alphabetical order. Since this may break
  3367     some proofs, these proofs either have to be repaired, e.g. by
  3368     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3369     statements of the form
  3370 
  3371       case (rule_i a_i_1 ... a_i_{k_i})
  3372 
  3373     or the old order of quantification has to be restored by explicitly adding
  3374     meta-level quantifiers in the introduction rules, i.e.
  3375 
  3376       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3377 
  3378   - The format of the elimination rules is now
  3379 
  3380       p z_1 ... z_m x_1 ... x_n ==>
  3381         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3382         ==> ... ==> P
  3383 
  3384     for predicates and
  3385 
  3386       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3387         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3388         ==> ... ==> P
  3389 
  3390     for sets rather than
  3391 
  3392       x : s z_1 ... z_m ==>
  3393         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3394         ==> ... ==> P
  3395 
  3396     This may require terms in goals to be expanded to n-tuples
  3397     (e.g. using case_tac or simplification with the split_paired_all
  3398     rule) before the above elimination rule is applicable.
  3399 
  3400   - The elimination or case analysis rules for (mutually) inductive
  3401     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3402     list of rules "p_1_..._p_k.elims" is no longer available.
  3403 
  3404 * New package "function"/"fun" for general recursive functions,
  3405 supporting mutual and nested recursion, definitions in local contexts,
  3406 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3407 for small examples, and the separate tutorial on the function
  3408 package. The old recdef "package" is still available as before, but
  3409 users are encouraged to use the new package.
  3410 
  3411 * Method "lexicographic_order" automatically synthesizes termination
  3412 relations as lexicographic combinations of size measures. 
  3413 
  3414 * Case-expressions allow arbitrary constructor-patterns (including
  3415 "_") and take their order into account, like in functional
  3416 programming.  Internally, this is translated into nested
  3417 case-expressions; missing cases are added and mapped to the predefined
  3418 constant "undefined". In complicated cases printing may no longer show
  3419 the original input but the internal form. Lambda-abstractions allow
  3420 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3421 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3422 variable.
  3423 
  3424 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3425 is an abbreviation for "of_nat :: nat => int". The simplification
  3426 rules for "of_nat" have been changed to work like "int" did
  3427 previously.  Potential INCOMPATIBILITY:
  3428   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3429   - of_nat_diff and of_nat_mult are no longer default simp rules
  3430 
  3431 * Method "algebra" solves polynomial equations over (semi)rings using
  3432 Groebner bases. The (semi)ring structure is defined by locales and the
  3433 tool setup depends on that generic context. Installing the method for
  3434 a specific type involves instantiating the locale and possibly adding
  3435 declarations for computation on the coefficients.  The method is
  3436 already instantiated for natural numbers and for the axiomatic class
  3437 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3438 CALCULEMUS 2007 for the general principles underlying this
  3439 architecture of context-aware proof-tools.
  3440 
  3441 * Method "ferrack" implements quantifier elimination over
  3442 special-purpose dense linear orders using locales (analogous to
  3443 "algebra"). The method is already installed for class
  3444 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3445 rat, etc.
  3446 
  3447 * Former constant "List.op @" now named "List.append".  Use ML
  3448 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3449 circumvent possible incompatibilities when working on ML level.
  3450 
  3451 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3452 
  3453 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3454 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3455 
  3456 * New syntax for Haskell-like list comprehension (input only), eg.
  3457 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3458 
  3459 * The special syntax for function "filter" has changed from [x :
  3460 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3461 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3462 
  3463 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3464 defined on nat only, as an abbreviation for [a..<Suc b]
  3465 INCOMPATIBILITY.
  3466 
  3467 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3468 
  3469 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3470 
  3471 * New lemma collection field_simps (an extension of ring_simps) for
  3472 manipulating (in)equations involving division. Multiplies with all
  3473 denominators that can be proved to be non-zero (in equations) or
  3474 positive/negative (in inequations).
  3475 
  3476 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3477 have been improved and renamed to ring_simps, group_simps and
  3478 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3479 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3480 
  3481 * Theory Library/Commutative_Ring: switched from recdef to function
  3482 package; constants add, mul, pow now curried.  Infix syntax for
  3483 algebraic operations.
  3484 
  3485 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3486 INCOMPATIBILITY.
  3487 
  3488 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3489 INCOMPATIBILITY.
  3490 
  3491 * HOL/records: generalised field-update to take a function on the
  3492 field rather than the new value: r(|A := x|) is translated to A_update
  3493 (K x) r The K-combinator that is internally used is called K_record.
  3494 INCOMPATIBILITY: Usage of the plain update functions has to be
  3495 adapted.
  3496  
  3497 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3498 * x = 0, which are required for a semiring.  Richer structures do not
  3499 inherit from semiring_0 anymore, because this property is a theorem
  3500 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3501 there is more to prove, but this is mostly trivial.
  3502 
  3503 * Class "recpower" is generalized to arbitrary monoids, not just
  3504 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3505 commutativity or semiring properties additionally.
  3506 
  3507 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3508 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3509 better use 'abbreviation'.
  3510 
  3511 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3512 
  3513 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3514 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3515 significant changes for setting up numeral syntax for types:
  3516   - New constants Numeral.pred and Numeral.succ instead
  3517       of former Numeral.bin_pred and Numeral.bin_succ.
  3518   - Use integer operations instead of bin_add, bin_mult and so on.
  3519   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3520   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3521 
  3522 See src/HOL/Integ/IntArith.thy for an example setup.
  3523 
  3524 * Command 'normal_form' computes the normal form of a term that may
  3525 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3526 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3527 heavy-duty computations because the functions are compiled to ML
  3528 first.  Correspondingly, a method "normalization" is provided.  See
  3529 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3530 
  3531 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3532 25 like -->); output depends on the "iff" print_mode, the default is
  3533 "A = B" (with priority 50).
  3534 
  3535 * Relations less (<) and less_eq (<=) are also available on type bool.
  3536 Modified syntax to disallow nesting without explicit parentheses,
  3537 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3538 INCOMPATIBILITY.
  3539 
  3540 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3541 
  3542 * Relation composition operator "op O" now has precedence 75 and binds
  3543 stronger than union and intersection. INCOMPATIBILITY.
  3544 
  3545 * The old set interval syntax "{m..n(}" (and relatives) has been
  3546 removed.  Use "{m..<n}" (and relatives) instead.
  3547 
  3548 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3549 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3550 ``declare [[simproc del: neq]]''.
  3551 
  3552 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3553 True/False.
  3554 
  3555 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3556 
  3557 * Theorem setsum_mult renamed to setsum_right_distrib.
  3558 
  3559 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3560 ``rule'' method.
  3561 
  3562 * Reimplemented methods "sat" and "satx", with several improvements:
  3563 goals no longer need to be stated as "<prems> ==> False", equivalences
  3564 (i.e. "=" on type bool) are handled, variable names of the form
  3565 "lit_<n>" are no longer reserved, significant speedup.
  3566 
  3567 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3568 zChaff is still supported as well.
  3569 
  3570 * 'inductive' and 'datatype': provide projections of mutual rules,
  3571 bundled as foo_bar.inducts;
  3572 
  3573 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3574 Library.
  3575 
  3576 * Library: moved theory Accessible_Part to main HOL.
  3577 
  3578 * Library: added theory Coinductive_List of potentially infinite lists
  3579 as greatest fixed-point.
  3580 
  3581 * Library: added theory AssocList which implements (finite) maps as
  3582 association lists.
  3583 
  3584 * Method "evaluation" solves goals (i.e. a boolean expression)
  3585 efficiently by compiling it to ML.  The goal is "proved" (via an
  3586 oracle) if it evaluates to True.
  3587 
  3588 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3589 also when invoked by the simplifier.  This results in the Simplifier
  3590 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3591 Configuration option fast_arith_split_limit=0 recovers the old
  3592 behavior.
  3593 
  3594 * Support for hex (0x20) and binary (0b1001) numerals.
  3595 
  3596 * New method: reify eqs (t), where eqs are equations for an
  3597 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3598 parameter, computes a term s::'b and a list xs::'a list and proves the
  3599 theorem I xs s = t. This is also known as reification or quoting. The
  3600 resulting theorem is applied to the subgoal to substitute t with I xs
  3601 s.  If t is omitted, the subgoal itself is reified.
  3602 
  3603 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3604 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3605 where f is supposed to be a computable function (in the sense of code
  3606 generattion). The method uses reify to compute s and xs as above then
  3607 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3608 r and finally gets the theorem t = r, which is again applied to the
  3609 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3610 
  3611 * Reflection: Automatic reification now handels binding, an example is
  3612 available in src/HOL/ex/ReflectionEx.thy
  3613 
  3614 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3615 command 'statespace' that is similar to 'record', but introduces an
  3616 abstract specification based on the locale infrastructure instead of
  3617 HOL types.  This leads to extra flexibility in composing state spaces,
  3618 in particular multiple inheritance and renaming of components.
  3619 
  3620 
  3621 *** HOL-Complex ***
  3622 
  3623 * Hyperreal: Functions root and sqrt are now defined on negative real
  3624 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3625 Nonnegativity side conditions have been removed from many lemmas, so
  3626 that more subgoals may now be solved by simplification; potential
  3627 INCOMPATIBILITY.
  3628 
  3629 * Real: new type classes formalize real normed vector spaces and
  3630 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3631 and norm :: 'a => real.
  3632 
  3633 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3634 reals into other types. The overloaded constant Reals :: 'a set is now
  3635 defined as range of_real; potential INCOMPATIBILITY.
  3636 
  3637 * Real: proper support for ML code generation, including 'quickcheck'.
  3638 Reals are implemented as arbitrary precision rationals.
  3639 
  3640 * Hyperreal: Several constants that previously worked only for the
  3641 reals have been generalized, so they now work over arbitrary vector
  3642 spaces. Type annotations may need to be added in some cases; potential
  3643 INCOMPATIBILITY.
  3644 
  3645   Infinitesimal  :: ('a::real_normed_vector) star set
  3646   HFinite        :: ('a::real_normed_vector) star set
  3647   HInfinite      :: ('a::real_normed_vector) star set
  3648   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3649   monad          :: ('a::real_normed_vector) star => 'a star set
  3650   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3651   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3652   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3653   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3654   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3655   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3656   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3657   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3658   sgn            :: 'a::real_normed_vector => 'a
  3659   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3660 
  3661 * Complex: Some complex-specific constants are now abbreviations for
  3662 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3663 hnorm.  Other constants have been entirely removed in favor of the
  3664 polymorphic versions (INCOMPATIBILITY):
  3665 
  3666   approx        <-- capprox
  3667   HFinite       <-- CFinite
  3668   HInfinite     <-- CInfinite
  3669   Infinitesimal <-- CInfinitesimal
  3670   monad         <-- cmonad
  3671   galaxy        <-- cgalaxy
  3672   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3673   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3674   (ns)deriv     <-- (ns)cderiv
  3675 
  3676 
  3677 *** HOL-Algebra ***
  3678 
  3679 * Formalisation of ideals and the quotient construction over rings.
  3680 
  3681 * Order and lattice theory no longer based on records.
  3682 INCOMPATIBILITY.
  3683 
  3684 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3685 greatest_closed.  INCOMPATIBILITY.
  3686 
  3687 * Method algebra is now set up via an attribute.  For examples see
  3688 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3689 of algebraic structures.
  3690 
  3691 * Renamed theory CRing to Ring.
  3692 
  3693 
  3694 *** HOL-Nominal ***
  3695 
  3696 * Substantial, yet incomplete support for nominal datatypes (binding
  3697 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3698 src/HOL/Nominal/Examples.  Prospective users should consult
  3699 http://isabelle.in.tum.de/nominal/
  3700 
  3701 
  3702 *** ML ***
  3703 
  3704 * ML basics: just one true type int, which coincides with IntInf.int
  3705 (even on SML/NJ).
  3706 
  3707 * ML within Isar: antiquotations allow to embed statically-checked
  3708 formal entities in the source, referring to the context available at
  3709 compile-time.  For example:
  3710 
  3711 ML {* @{sort "{zero,one}"} *}
  3712 ML {* @{typ "'a => 'b"} *}
  3713 ML {* @{term "%x. x"} *}
  3714 ML {* @{prop "x == y"} *}
  3715 ML {* @{ctyp "'a => 'b"} *}
  3716 ML {* @{cterm "%x. x"} *}
  3717 ML {* @{cprop "x == y"} *}
  3718 ML {* @{thm asm_rl} *}
  3719 ML {* @{thms asm_rl} *}
  3720 ML {* @{type_name c} *}
  3721 ML {* @{type_syntax c} *}
  3722 ML {* @{const_name c} *}
  3723 ML {* @{const_syntax c} *}
  3724 ML {* @{context} *}
  3725 ML {* @{theory} *}
  3726 ML {* @{theory Pure} *}
  3727 ML {* @{theory_ref} *}
  3728 ML {* @{theory_ref Pure} *}
  3729 ML {* @{simpset} *}
  3730 ML {* @{claset} *}
  3731 ML {* @{clasimpset} *}
  3732 
  3733 The same works for sources being ``used'' within an Isar context.
  3734 
  3735 * ML in Isar: improved error reporting; extra verbosity with
  3736 ML_Context.trace enabled.
  3737 
  3738 * Pure/General/table.ML: the join operations now works via exceptions
  3739 DUP/SAME instead of type option. This is simpler in simple cases, and
  3740 admits slightly more efficient complex applications.
  3741 
  3742 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3743 use Context.generic instead of just theory.
  3744 
  3745 * Pure: datatype Context.generic joins theory/Proof.context and
  3746 provides some facilities for code that works in either kind of
  3747 context, notably GenericDataFun for uniform theory and proof data.
  3748 
  3749 * Pure: simplified internal attribute type, which is now always
  3750 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3751 local (Proof.context) attributes have been discontinued, while
  3752 minimizing code duplication. Thm.rule_attribute and
  3753 Thm.declaration_attribute build canonical attributes; see also structure
  3754 Context for further operations on Context.generic, notably
  3755 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3756 declarations and definitions.
  3757 
  3758 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3759 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3760 init only required for impure data. INCOMPATIBILITY: empty really need
  3761 to be empty (no dependencies on theory content!)
  3762 
  3763 * Pure/kernel: consts certification ignores sort constraints given in
  3764 signature declarations. (This information is not relevant to the
  3765 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3766 potential INCOMPATIBILITY.
  3767 
  3768 * Pure: axiomatic type classes are now purely definitional, with
  3769 explicit proofs of class axioms and super class relations performed
  3770 internally. See Pure/axclass.ML for the main internal interfaces --
  3771 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3772 AxClass.axiomatize_class/classrel/arity supersede
  3773 Sign.add_classes/classrel/arities.
  3774 
  3775 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3776 global/local versions on theory vs. Proof.context have been
  3777 discontinued; Attrib.syntax and Method.syntax have been adapted
  3778 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3779 attributes, methods, etc.
  3780 
  3781 * Pure: several functions of signature "... -> theory -> theory * ..."
  3782 have been reoriented to "... -> theory -> ... * theory" in order to
  3783 allow natural usage in combination with the ||>, ||>>, |-> and
  3784 fold_map combinators.
  3785 
  3786 * Pure: official theorem names (closed derivations) and additional
  3787 comments (tags) are now strictly separate.  Name hints -- which are
  3788 maintained as tags -- may be attached any time without affecting the
  3789 derivation.
  3790 
  3791 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3792 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3793 achieve the old behaviour.
  3794 
  3795 * Pure: the "Goal" constant is now called "prop", supporting a
  3796 slightly more general idea of ``protecting'' meta-level rule
  3797 statements.
  3798 
  3799 * Pure: Logic.(un)varify only works in a global context, which is now
  3800 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3801 Logic.legacy_(un)varify as temporary workaround.
  3802 
  3803 * Pure: structure Name provides scalable operations for generating
  3804 internal variable names, notably Name.variants etc.  This replaces
  3805 some popular functions from term.ML:
  3806 
  3807   Term.variant		->  Name.variant
  3808   Term.variantlist	->  Name.variant_list
  3809   Term.invent_names	->  Name.invent_list
  3810 
  3811 Note that low-level renaming rarely occurs in new code -- operations
  3812 from structure Variable are used instead (see below).
  3813 
  3814 * Pure: structure Variable provides fundamental operations for proper
  3815 treatment of fixed/schematic variables in a context.  For example,
  3816 Variable.import introduces fixes for schematics of given facts and
  3817 Variable.export reverses the effect (up to renaming) -- this replaces
  3818 various freeze_thaw operations.
  3819 
  3820 * Pure: structure Goal provides simple interfaces for
  3821 init/conclude/finish and tactical prove operations (replacing former
  3822 Tactic.prove).  Goal.prove is the canonical way to prove results
  3823 within a given context; Goal.prove_global is a degraded version for
  3824 theory level goals, including a global Drule.standard.  Note that
  3825 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3826 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3827 in a locale context).
  3828 
  3829 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3830 and type checking (Syntax.check_term etc.), with common combinations
  3831 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3832 which are considered legacy and await removal.
  3833 
  3834 * Pure/Syntax: generic interfaces for type unchecking
  3835 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3836 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3837 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3838 available for convenience, but refer to the very same operations using
  3839 a mere theory instead of a full context.
  3840 
  3841 * Isar: simplified treatment of user-level errors, using exception
  3842 ERROR of string uniformly.  Function error now merely raises ERROR,
  3843 without any side effect on output channels.  The Isar toplevel takes
  3844 care of proper display of ERROR exceptions.  ML code may use plain
  3845 handle/can/try; cat_error may be used to concatenate errors like this:
  3846 
  3847   ... handle ERROR msg => cat_error msg "..."
  3848 
  3849 Toplevel ML code (run directly or through the Isar toplevel) may be
  3850 embedded into the Isar toplevel with exception display/debug like
  3851 this:
  3852 
  3853   Isar.toplevel (fn () => ...)
  3854 
  3855 INCOMPATIBILITY, removed special transform_error facilities, removed
  3856 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3857 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3858 -- use plain ERROR instead.
  3859 
  3860 * Isar: theory setup now has type (theory -> theory), instead of a
  3861 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3862 
  3863 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3864 ProofContext.debug/verbose flags.
  3865 
  3866 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3867 theory before entering a proof state.  Transactions now always see a
  3868 quasi-functional intermediate checkpoint, both in interactive and
  3869 batch mode.
  3870 
  3871 * Isar: simplified interfaces for outer syntax.  Renamed
  3872 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3873 OuterSyntax.add_parsers -- this functionality is now included in
  3874 OuterSyntax.command etc.  INCOMPATIBILITY.
  3875 
  3876 * Simplifier: the simpset of a running simplification process now
  3877 contains a proof context (cf. Simplifier.the_context), which is the
  3878 very context that the initial simpset has been retrieved from (by
  3879 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3880 (solver, looper etc.) may depend on arbitrary proof data.
  3881 
  3882 * Simplifier.inherit_context inherits the proof context (plus the
  3883 local bounds) of the current simplification process; any simproc
  3884 etc. that calls the Simplifier recursively should do this!  Removed
  3885 former Simplifier.inherit_bounds, which is already included here --
  3886 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3887 specify an explicit context using Simplifier.context/theory_context.
  3888 
  3889 * Simplifier/Classical Reasoner: more abstract interfaces
  3890 change_simpset/claset for modifying the simpset/claset reference of a
  3891 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3892 INCOMPATIBILITY.
  3893 
  3894 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3895 "Trueprop" etc.
  3896 
  3897 
  3898 *** System ***
  3899 
  3900 * settings: the default heap location within ISABELLE_HOME_USER now
  3901 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3902 Isabelle installations.
  3903 
  3904 * isabelle-process: option -S (secure mode) disables some critical
  3905 operations, notably runtime compilation and evaluation of ML source
  3906 code.
  3907 
  3908 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3909 
  3910 * Support for parallel execution, using native multicore support of
  3911 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3912 independent theories, according to the given theory header
  3913 specifications. The maximum number of worker threads is specified via
  3914 usedir option -M or the "max-threads" setting in Proof General. A
  3915 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3916 to 6 on a 8-core machine.  User-code needs to observe certain
  3917 guidelines for thread-safe programming, see appendix A in the Isar
  3918 Implementation manual.
  3919 
  3920 
  3921 
  3922 New in Isabelle2005 (October 2005)
  3923 ----------------------------------
  3924 
  3925 *** General ***
  3926 
  3927 * Theory headers: the new header syntax for Isar theories is
  3928 
  3929   theory <name>
  3930   imports <theory1> ... <theoryN>
  3931   uses <file1> ... <fileM>
  3932   begin
  3933 
  3934 where the 'uses' part is optional.  The previous syntax
  3935 
  3936   theory <name> = <theory1> + ... + <theoryN>:
  3937 
  3938 will disappear in the next release.  Use isatool fixheaders to convert
  3939 existing theory files.  Note that there is no change in ancient
  3940 non-Isar theories now, but these will disappear soon.
  3941 
  3942 * Theory loader: parent theories can now also be referred to via
  3943 relative and absolute paths.
  3944 
  3945 * Command 'find_theorems' searches for a list of criteria instead of a
  3946 list of constants. Known criteria are: intro, elim, dest, name:string,
  3947 simp:term, and any term. Criteria can be preceded by '-' to select
  3948 theorems that do not match. Intro, elim, dest select theorems that
  3949 match the current goal, name:s selects theorems whose fully qualified
  3950 name contain s, and simp:term selects all simplification rules whose
  3951 lhs match term.  Any other term is interpreted as pattern and selects
  3952 all theorems matching the pattern. Available in ProofGeneral under
  3953 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3954 
  3955   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3956 
  3957 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3958 matching the current goal as introduction rule and not having "HOL."
  3959 in their name (i.e. not being defined in theory HOL).
  3960 
  3961 * Command 'thms_containing' has been discontinued in favour of
  3962 'find_theorems'; INCOMPATIBILITY.
  3963 
  3964 * Communication with Proof General is now 8bit clean, which means that
  3965 Unicode text in UTF-8 encoding may be used within theory texts (both
  3966 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3967 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3968 
  3969   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3970   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3971 
  3972 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3973 Classical Reasoner.  Typical big applications run around 2 times
  3974 faster.
  3975 
  3976 
  3977 *** Document preparation ***
  3978 
  3979 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3980 of raw sources.  Only those symbols that do not require additional
  3981 LaTeX packages (depending on comments in isabellesym.sty) are
  3982 displayed properly, everything else is left verbatim.  isatool display
  3983 and isatool print are used as front ends (these are subject to the
  3984 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3985 
  3986 * Command tags control specific markup of certain regions of text,
  3987 notably folding and hiding.  Predefined tags include "theory" (for
  3988 theory begin and end), "proof" for proof commands, and "ML" for
  3989 commands involving ML code; the additional tags "visible" and
  3990 "invisible" are unused by default.  Users may give explicit tag
  3991 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3992 interpretation of tags is determined by the LaTeX job during document
  3993 preparation: see option -V of isatool usedir, or options -n and -t of
  3994 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3995 \isadroptag.
  3996 
  3997 Several document versions may be produced at the same time via isatool
  3998 usedir (the generated index.html will link all of them).  Typical
  3999 specifications include ''-V document=theory,proof,ML'' to present
  4000 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4001 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4002 these parts without any formal replacement text.  The Isabelle site
  4003 default settings produce ''document'' and ''outline'' versions as
  4004 specified above.
  4005 
  4006 * Several new antiquotations:
  4007 
  4008   @{term_type term} prints a term with its type annotated;
  4009 
  4010   @{typeof term} prints the type of a term;
  4011 
  4012   @{const const} is the same as @{term const}, but checks that the
  4013   argument is a known logical constant;
  4014 
  4015   @{term_style style term} and @{thm_style style thm} print a term or
  4016   theorem applying a "style" to it
  4017 
  4018   @{ML text}
  4019 
  4020 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4021 definitions, equations, inequations etc., 'concl' printing only the
  4022 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4023 to print the specified premise.  TermStyle.add_style provides an ML
  4024 interface for introducing further styles.  See also the "LaTeX Sugar"
  4025 document practical applications.  The ML antiquotation prints
  4026 type-checked ML expressions verbatim.
  4027 
  4028 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4029 and 'text' support optional locale specification '(in loc)', which
  4030 specifies the default context for interpreting antiquotations.  For
  4031 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4032 
  4033 * Option 'locale=NAME' of antiquotations specifies an alternative
  4034 context interpreting the subsequent argument.  For example: @{thm
  4035 [locale=lattice] inf_assoc}.
  4036 
  4037 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4038 a proof context.
  4039 
  4040 * Proper output of antiquotations for theory commands involving a
  4041 proof context (such as 'locale' or 'theorem (in loc) ...').
  4042 
  4043 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4044 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4045 
  4046 * isatool usedir: new option -C (default true) controls whether option
  4047 -D should include a copy of the original document directory; -C false
  4048 prevents unwanted effects such as copying of administrative CVS data.
  4049 
  4050 
  4051 *** Pure ***
  4052 
  4053 * Considerably improved version of 'constdefs' command.  Now performs
  4054 automatic type-inference of declared constants; additional support for
  4055 local structure declarations (cf. locales and HOL records), see also
  4056 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4057 sequential dependencies of definitions within a single 'constdefs'
  4058 section; moreover, the declared name needs to be an identifier.  If
  4059 all fails, consider to fall back on 'consts' and 'defs' separately.
  4060 
  4061 * Improved indexed syntax and implicit structures.  First of all,
  4062 indexed syntax provides a notational device for subscripted
  4063 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4064 expressions.  Secondly, in a local context with structure
  4065 declarations, number indexes \<^sub>n or the empty index (default
  4066 number 1) refer to a certain fixed variable implicitly; option
  4067 show_structs controls printing of implicit structures.  Typical
  4068 applications of these concepts involve record types and locales.
  4069 
  4070 * New command 'no_syntax' removes grammar declarations (and
  4071 translations) resulting from the given syntax specification, which is
  4072 interpreted in the same manner as for the 'syntax' command.
  4073 
  4074 * 'Advanced' translation functions (parse_translation etc.) may depend
  4075 on the signature of the theory context being presently used for
  4076 parsing/printing, see also isar-ref manual.
  4077 
  4078 * Improved 'oracle' command provides a type-safe interface to turn an
  4079 ML expression of type theory -> T -> term into a primitive rule of
  4080 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4081 is already included here); see also FOL/ex/IffExample.thy;
  4082 INCOMPATIBILITY.
  4083 
  4084 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4085 before); "cI" is no longer bound, use "c.intro" instead.
  4086 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4087 axclasses vs. locales.
  4088 
  4089 * Improved internal renaming of symbolic identifiers -- attach primes
  4090 instead of base 26 numbers.
  4091 
  4092 * New flag show_question_marks controls printing of leading question
  4093 marks in schematic variable names.
  4094 
  4095 * In schematic variable names, *any* symbol following \<^isub> or
  4096 \<^isup> is now treated as part of the base name.  For example, the
  4097 following works without printing of awkward ".0" indexes:
  4098 
  4099   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4100     by simp
  4101 
  4102 * Inner syntax includes (*(*nested*) comments*).
  4103 
  4104 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4105 annotations as "(00...)".
  4106 
  4107 * Clear separation of logical types and nonterminals, where the latter
  4108 may only occur in 'syntax' specifications or type abbreviations.
  4109 Before that distinction was only partially implemented via type class
  4110 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4111 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4112 exotic syntax specifications may require further adaption
  4113 (e.g. Cube/Cube.thy).
  4114 
  4115 * Removed obsolete type class "logic", use the top sort {} instead.
  4116 Note that non-logical types should be declared as 'nonterminals'
  4117 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4118 specifications.
  4119 
  4120 * Attributes 'induct' and 'cases': type or set names may now be
  4121 locally fixed variables as well.
  4122 
  4123 * Simplifier: can now control the depth to which conditional rewriting
  4124 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4125 Limit.
  4126 
  4127 * Simplifier: simplification procedures may now take the current
  4128 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4129 interface), which is very useful for calling the Simplifier
  4130 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4131 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4132 low-level mk_simproc no longer applies Logic.varify internally, to
  4133 allow for use in a context of fixed variables.
  4134 
  4135 * thin_tac now works even if the assumption being deleted contains !!
  4136 or ==>.  More generally, erule now works even if the major premise of
  4137 the elimination rule contains !! or ==>.
  4138 
  4139 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4140 
  4141 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4142 from Pure, which contains all common declarations already.  Both
  4143 theories are defined via plain Isabelle/Isar .thy files.
  4144 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4145 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4146 use isatool fixcpure to adapt your theory and ML sources.
  4147 
  4148 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4149 selections of theorems in named facts via index ranges.
  4150 
  4151 * 'print_theorems': in theory mode, really print the difference
  4152 wrt. the last state (works for interactive theory development only),
  4153 in proof mode print all local facts (cf. 'print_facts');
  4154 
  4155 * 'hide': option '(open)' hides only base names.
  4156 
  4157 * More efficient treatment of intermediate checkpoints in interactive
  4158 theory development.
  4159 
  4160 * Code generator is now invoked via code_module (incremental code
  4161 generation) and code_library (modular code generation, ML structures
  4162 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4163 must be quoted when used as identifiers.
  4164 
  4165 * New 'value' command for reading, evaluating and printing terms using
  4166 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4167 quoted when used as identifier.
  4168 
  4169 
  4170 *** Locales ***
  4171 
  4172 * New commands for the interpretation of locale expressions in
  4173 theories (1), locales (2) and proof contexts (3).  These generate
  4174 proof obligations from the expression specification.  After the
  4175 obligations have been discharged, theorems of the expression are added
  4176 to the theory, target locale or proof context.  The synopsis of the
  4177 commands is a follows:
  4178 
  4179   (1) interpretation expr inst
  4180   (2) interpretation target < expr
  4181   (3) interpret expr inst
  4182 
  4183 Interpretation in theories and proof contexts require a parameter
  4184 instantiation of terms from the current context.  This is applied to
  4185 specifications and theorems of the interpreted expression.
  4186 Interpretation in locales only permits parameter renaming through the
  4187 locale expression.  Interpretation is smart in that interpretations
  4188 that are active already do not occur in proof obligations, neither are
  4189 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4190 inspect active interpretations of a particular locale.  For details,
  4191 see the Isar Reference manual.  Examples can be found in
  4192 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4193 
  4194 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4195 'interpret' instead.
  4196 
  4197 * New context element 'constrains' for adding type constraints to
  4198 parameters.
  4199 
  4200 * Context expressions: renaming of parameters with syntax
  4201 redeclaration.
  4202 
  4203 * Locale declaration: 'includes' disallowed.
  4204 
  4205 * Proper static binding of attribute syntax -- i.e. types / terms /
  4206 facts mentioned as arguments are always those of the locale definition
  4207 context, independently of the context of later invocations.  Moreover,
  4208 locale operations (renaming and type / term instantiation) are applied
  4209 to attribute arguments as expected.
  4210 
  4211 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4212 actual attributes; rare situations may require Attrib.attribute to
  4213 embed those attributes into Attrib.src that lack concrete syntax.
  4214 Attribute implementations need to cooperate properly with the static
  4215 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4216 Attrib.XXX_thm etc. already do the right thing without further
  4217 intervention.  Only unusual applications -- such as "where" or "of"
  4218 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4219 on the context and the facts involved -- may have to assign parsed
  4220 values to argument tokens explicitly.
  4221 
  4222 * Changed parameter management in theorem generation for long goal
  4223 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4224 theorem statement in rare situations.
  4225 
  4226 * Locale inspection command 'print_locale' omits notes elements.  Use
  4227 'print_locale!' to have them included in the output.
  4228 
  4229 
  4230 *** Provers ***
  4231 
  4232 * Provers/hypsubst.ML: improved version of the subst method, for
  4233 single-step rewriting: it now works in bound variable contexts. New is
  4234 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4235 rewrite a different subterm than the original subst method, which is
  4236 still available as 'simplesubst'.
  4237 
  4238 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4239 and quasi orders.
  4240 
  4241 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4242 reflexive-transitive closure of relations.
  4243 
  4244 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4245 limit (previously hard-coded with a value of 20) user-definable.
  4246 
  4247 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4248 is peformed already.  Object-logics merely need to finish their
  4249 initial simpset configuration as before.  INCOMPATIBILITY.
  4250 
  4251 
  4252 *** HOL ***
  4253 
  4254 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4255 
  4256   syntax (epsilon)
  4257     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4258 
  4259 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4260 and x-symbol; use option '-m epsilon' to get it actually printed.
  4261 Moreover, the mathematically important symbolic identifier \<epsilon>
  4262 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4263 
  4264 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4265 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4266 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4267 support corresponding Isar calculations.
  4268 
  4269 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4270 instead of ":".
  4271 
  4272 * theory SetInterval: changed the syntax for open intervals:
  4273 
  4274   Old       New
  4275   {..n(}    {..<n}
  4276   {)n..}    {n<..}
  4277   {m..n(}   {m..<n}
  4278   {)m..n}   {m<..n}
  4279   {)m..n(}  {m<..<n}
  4280 
  4281 The old syntax is still supported but will disappear in the next
  4282 release.  For conversion use the following Emacs search and replace
  4283 patterns (these are not perfect but work quite well):
  4284 
  4285   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4286   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4287 
  4288 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4289 equalities in commutative rings; method 'algebra' provides a generic
  4290 interface.
  4291 
  4292 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4293 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4294 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4295 be a tuple pattern.
  4296 
  4297 Some new syntax forms are available:
  4298 
  4299   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4300   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4301   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4302   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4303 
  4304 The latter form "\<Sum>x < k. e" used to be based on a separate
  4305 function "Summation", which has been discontinued.
  4306 
  4307 * theory Finite_Set: in structured induction proofs, the insert case
  4308 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4309 (insert F x)'.
  4310 
  4311 * The 'refute' command has been extended to support a much larger
  4312 fragment of HOL, including axiomatic type classes, constdefs and
  4313 typedefs, inductive datatypes and recursion.
  4314 
  4315 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4316 Requires zChaff with proof generation to be installed.  See
  4317 HOL/ex/SAT_Examples.thy for examples.
  4318 
  4319 * Datatype induction via method 'induct' now preserves the name of the
  4320 induction variable. For example, when proving P(xs::'a list) by
  4321 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4322 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4323 in unstructured proof scripts.
  4324 
  4325 * Reworked implementation of records.  Improved scalability for
  4326 records with many fields, avoiding performance problems for type
  4327 inference. Records are no longer composed of nested field types, but
  4328 of nested extension types. Therefore the record type only grows linear
  4329 in the number of extensions and not in the number of fields.  The
  4330 top-level (users) view on records is preserved.  Potential
  4331 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4332 old record representation. The type generated for a record is called
  4333 <record_name>_ext_type.
  4334 
  4335 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4336 proofs triggered by a record definition or a simproc (if
  4337 quick_and_dirty is enabled).  Definitions of large records can take
  4338 quite long.
  4339 
  4340 New simproc record_upd_simproc for simplification of multiple record
  4341 updates enabled by default.  Moreover, trivial updates are also
  4342 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4343 occasionally, since simplification is more powerful by default.
  4344 
  4345 * typedef: proper support for polymorphic sets, which contain extra
  4346 type-variables in the term.
  4347 
  4348 * Simplifier: automatically reasons about transitivity chains
  4349 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4350 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4351 old proofs break occasionally as simplification may now solve more
  4352 goals than previously.
  4353 
  4354 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4355 present.  Works for all partial orders (class "order"), in particular
  4356 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4357 just like y <= x.
  4358 
  4359 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4360 bound variable or a constant then the let is unfolded.  Otherwise
  4361 first a is simplified to b, and then f b is simplified to g. If
  4362 possible we abstract b from g arriving at "let x = b in h x",
  4363 otherwise we unfold the let and arrive at g.  The simproc can be
  4364 enabled/disabled by the reference use_let_simproc.  Potential
  4365 INCOMPATIBILITY since simplification is more powerful by default.
  4366 
  4367 * Classical reasoning: the meson method now accepts theorems as arguments.
  4368 
  4369 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4370 jobs to provide advice on the provability of subgoals.
  4371 
  4372 * Theory OrderedGroup and Ring_and_Field: various additions and
  4373 improvements to faciliate calculations involving equalities and
  4374 inequalities.
  4375 
  4376 The following theorems have been eliminated or modified
  4377 (INCOMPATIBILITY):
  4378 
  4379   abs_eq             now named abs_of_nonneg
  4380   abs_of_ge_0        now named abs_of_nonneg
  4381   abs_minus_eq       now named abs_of_nonpos
  4382   imp_abs_id         now named abs_of_nonneg
  4383   imp_abs_neg_id     now named abs_of_nonpos
  4384   mult_pos           now named mult_pos_pos
  4385   mult_pos_le        now named mult_nonneg_nonneg
  4386   mult_pos_neg_le    now named mult_nonneg_nonpos
  4387   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4388   mult_neg           now named mult_neg_neg
  4389   mult_neg_le        now named mult_nonpos_nonpos
  4390 
  4391 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4392      
  4393      zero_le_square
  4394      not_square_less_zero 
  4395 
  4396   The following lemmas have been deleted from Real/RealPow:
  4397   
  4398      realpow_zero_zero
  4399      realpow_two
  4400      realpow_less
  4401      zero_le_power
  4402      realpow_two_le
  4403      abs_realpow_two
  4404      realpow_two_abs     
  4405 
  4406 * Theory Parity: added rules for simplifying exponents.
  4407 
  4408 * Theory List:
  4409 
  4410 The following theorems have been eliminated or modified
  4411 (INCOMPATIBILITY):
  4412 
  4413   list_all_Nil       now named list_all.simps(1)
  4414   list_all_Cons      now named list_all.simps(2)
  4415   list_all_conv      now named list_all_iff
  4416   set_mem_eq         now named mem_iff
  4417 
  4418 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4419 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4420 
  4421 
  4422 *** HOL-Complex ***
  4423 
  4424 * Theory RealDef: better support for embedding natural numbers and
  4425 integers in the reals.
  4426 
  4427 The following theorems have been eliminated or modified
  4428 (INCOMPATIBILITY):
  4429 
  4430   exp_ge_add_one_self  now requires no hypotheses
  4431   real_of_int_add      reversed direction of equality (use [symmetric])
  4432   real_of_int_minus    reversed direction of equality (use [symmetric])
  4433   real_of_int_diff     reversed direction of equality (use [symmetric])
  4434   real_of_int_mult     reversed direction of equality (use [symmetric])
  4435 
  4436 * Theory RComplete: expanded support for floor and ceiling functions.
  4437 
  4438 * Theory Ln is new, with properties of the natural logarithm
  4439 
  4440 * Hyperreal: There is a new type constructor "star" for making
  4441 nonstandard types.  The old type names are now type synonyms:
  4442 
  4443   hypreal = real star
  4444   hypnat = nat star
  4445   hcomplex = complex star
  4446 
  4447 * Hyperreal: Many groups of similarly-defined constants have been
  4448 replaced by polymorphic versions (INCOMPATIBILITY):
  4449 
  4450   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4451 
  4452   starset      <-- starsetNat, starsetC
  4453   *s*          <-- *sNat*, *sc*
  4454   starset_n    <-- starsetNat_n, starsetC_n
  4455   *sn*         <-- *sNatn*, *scn*
  4456   InternalSets <-- InternalNatSets, InternalCSets
  4457 
  4458   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4459   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4460   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4461   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4462   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4463 
  4464 * Hyperreal: Many type-specific theorems have been removed in favor of
  4465 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4466 
  4467   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4468   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4469   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4470   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4471   right_minus <-- hypreal_add_minus
  4472   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4473   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4474   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4475   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4476   mult_1_right <-- hcomplex_mult_one_right
  4477   mult_zero_left <-- hcomplex_mult_zero_left
  4478   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4479   right_distrib <-- hypnat_add_mult_distrib2
  4480   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4481   right_inverse <-- hypreal_mult_inverse
  4482   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4483   order_refl <-- {hypreal,hypnat}_le_refl
  4484   order_trans <-- {hypreal,hypnat}_le_trans
  4485   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4486   order_less_le <-- {hypreal,hypnat}_less_le
  4487   linorder_linear <-- {hypreal,hypnat}_le_linear
  4488   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4489   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4490   add_nonneg_nonneg <-- hypreal_le_add_order
  4491 
  4492 * Hyperreal: Separate theorems having to do with type-specific
  4493 versions of constants have been merged into theorems that apply to the
  4494 new polymorphic constants (INCOMPATIBILITY):
  4495 
  4496   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4497   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4498   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4499   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4500   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4501   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4502   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4503   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4504   STAR_diff <-- {STAR,STARC}_diff
  4505   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4506     STARC_hcomplex_of_complex}_image_subset
  4507   starset_n_Un <-- starset{Nat,C}_n_Un
  4508   starset_n_Int <-- starset{Nat,C}_n_Int
  4509   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4510   starset_n_diff <-- starset{Nat,C}_n_diff
  4511   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4512   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4513   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4514   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4515   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4516   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4517   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4518   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4519   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4520   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4521   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4522   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4523   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4524   starfun_diff <-- starfun{C,RC,CR}_diff
  4525   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4526   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4527   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4528   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4529   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4530   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4531   starfun_Id <-- starfunC_Id
  4532   starfun_approx <-- starfun{Nat,CR}_approx
  4533   starfun_capprox <-- starfun{C,RC}_capprox
  4534   starfun_abs <-- starfunNat_rabs
  4535   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4536   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4537   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4538   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4539   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4540   starfun_add_approx <-- starfunCR_add_approx
  4541   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4542   starfun_divide <-- starfun{C,CR,RC}_divide
  4543   starfun_n <-- starfun{Nat,C}_n
  4544   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4545   starfun_n_add <-- starfun{Nat,C}_n_add
  4546   starfun_n_add_minus <-- starfunNat_n_add_minus
  4547   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4548   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4549   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4550 
  4551   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4552   star_n_minus <-- {hypreal,hcomplex}_minus
  4553   star_n_diff <-- {hypreal,hcomplex}_diff
  4554   star_n_mult <-- {hypreal,hcomplex}_mult
  4555   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4556   star_n_le <-- {hypreal,hypnat}_le
  4557   star_n_less <-- {hypreal,hypnat}_less
  4558   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4559   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4560   star_n_abs <-- hypreal_hrabs
  4561   star_n_divide <-- hcomplex_divide
  4562 
  4563   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4564   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4565   star_of_diff <-- hypreal_of_real_diff
  4566   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4567   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4568   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4569   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4570   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4571   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4572   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4573   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4574   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4575   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4576   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4577   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4578   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4579   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4580   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4581   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4582   star_of_power <-- hypreal_of_real_power
  4583   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4584 
  4585 * Hyperreal: new method "transfer" that implements the transfer
  4586 principle of nonstandard analysis. With a subgoal that mentions
  4587 nonstandard types like "'a star", the command "apply transfer"
  4588 replaces it with an equivalent one that mentions only standard types.
  4589 To be successful, all free variables must have standard types; non-
  4590 standard variables must have explicit universal quantifiers.
  4591 
  4592 * Hyperreal: A theory of Taylor series.
  4593 
  4594 
  4595 *** HOLCF ***
  4596 
  4597 * Discontinued special version of 'constdefs' (which used to support
  4598 continuous functions) in favor of the general Pure one with full
  4599 type-inference.
  4600 
  4601 * New simplification procedure for solving continuity conditions; it
  4602 is much faster on terms with many nested lambda abstractions (cubic
  4603 instead of exponential time).
  4604 
  4605 * New syntax for domain package: selector names are now optional.
  4606 Parentheses should be omitted unless argument is lazy, for example:
  4607 
  4608   domain 'a stream = cons "'a" (lazy "'a stream")
  4609 
  4610 * New command 'fixrec' for defining recursive functions with pattern
  4611 matching; defining multiple functions with mutual recursion is also
  4612 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4613 sinr, or any data constructor defined by the domain package. The given
  4614 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4615 syntax and examples.
  4616 
  4617 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4618 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4619 but the proof obligation additionally includes an admissibility
  4620 requirement. The packages generate instances of class cpo or pcpo,
  4621 with continuity and strictness theorems for Rep and Abs.
  4622 
  4623 * HOLCF: Many theorems have been renamed according to a more standard naming
  4624 scheme (INCOMPATIBILITY):
  4625 
  4626   foo_inject:  "foo$x = foo$y ==> x = y"
  4627   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4628   foo_less:    "(foo$x << foo$y) = (x << y)"
  4629   foo_strict:  "foo$UU = UU"
  4630   foo_defined: "... ==> foo$x ~= UU"
  4631   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4632 
  4633 
  4634 *** ZF ***
  4635 
  4636 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4637 including the First Isomorphism Theorem (on quotienting by the kernel
  4638 of a homomorphism).
  4639 
  4640 * ZF/Simplifier: install second copy of type solver that actually
  4641 makes use of TC rules declared to Isar proof contexts (or locales);
  4642 the old version is still required for ML proof scripts.
  4643 
  4644 
  4645 *** Cube ***
  4646 
  4647 * Converted to Isar theory format; use locales instead of axiomatic
  4648 theories.
  4649 
  4650 
  4651 *** ML ***
  4652 
  4653 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4654 for ||>, ||>>, |>>,
  4655 
  4656 * Pure/library.ML no longer defines its own option datatype, but uses
  4657 that of the SML basis, which has constructors NONE and SOME instead of
  4658 None and Some, as well as exception Option.Option instead of OPTION.
  4659 The functions the, if_none, is_some, is_none have been adapted
  4660 accordingly, while Option.map replaces apsome.
  4661 
  4662 * Pure/library.ML: the exception LIST has been given up in favour of
  4663 the standard exceptions Empty and Subscript, as well as
  4664 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4665 superceded by the standard hd and tl functions etc.
  4666 
  4667 A number of basic list functions are no longer exported to the ML
  4668 toplevel, as they are variants of predefined functions.  The following
  4669 suggests how one can translate existing code:
  4670 
  4671     rev_append xs ys = List.revAppend (xs, ys)
  4672     nth_elem (i, xs) = List.nth (xs, i)
  4673     last_elem xs = List.last xs
  4674     flat xss = List.concat xss
  4675     seq fs = List.app fs
  4676     partition P xs = List.partition P xs
  4677     mapfilter f xs = List.mapPartial f xs
  4678 
  4679 * Pure/library.ML: several combinators for linear functional
  4680 transformations, notably reverse application and composition:
  4681 
  4682   x |> f                f #> g
  4683   (x, y) |-> f          f #-> g
  4684 
  4685 * Pure/library.ML: introduced/changed precedence of infix operators:
  4686 
  4687   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4688   infix 2 ?;
  4689   infix 3 o oo ooo oooo;
  4690   infix 4 ~~ upto downto;
  4691 
  4692 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4693 infix operators.
  4694 
  4695 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4696 fold_map support linear functional transformations and nesting.  For
  4697 example:
  4698 
  4699   fold f [x1, ..., xN] y =
  4700     y |> f x1 |> ... |> f xN
  4701 
  4702   (fold o fold) f [xs1, ..., xsN] y =
  4703     y |> fold f xs1 |> ... |> fold f xsN
  4704 
  4705   fold f [x1, ..., xN] =
  4706     f x1 #> ... #> f xN
  4707 
  4708   (fold o fold) f [xs1, ..., xsN] =
  4709     fold f xs1 #> ... #> fold f xsN
  4710 
  4711 * Pure/library.ML: the following selectors on type 'a option are
  4712 available:
  4713 
  4714   the:               'a option -> 'a  (*partial*)
  4715   these:             'a option -> 'a  where 'a = 'b list
  4716   the_default: 'a -> 'a option -> 'a
  4717   the_list:          'a option -> 'a list
  4718 
  4719 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4720 basic operations for association lists, following natural argument
  4721 order; moreover the explicit equality predicate passed here avoids
  4722 potentially expensive polymorphic runtime equality checks.
  4723 The old functions may be expressed as follows:
  4724 
  4725   assoc = uncurry (AList.lookup (op =))
  4726   assocs = these oo AList.lookup (op =)
  4727   overwrite = uncurry (AList.update (op =)) o swap
  4728 
  4729 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4730 
  4731   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4732   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4733 
  4734 replacing make_keylist and keyfilter (occassionally used)
  4735 Naive rewrites:
  4736 
  4737   make_keylist = AList.make
  4738   keyfilter = AList.find (op =)
  4739 
  4740 * eq_fst and eq_snd now take explicit equality parameter, thus
  4741   avoiding eqtypes. Naive rewrites:
  4742 
  4743     eq_fst = eq_fst (op =)
  4744     eq_snd = eq_snd (op =)
  4745 
  4746 * Removed deprecated apl and apr (rarely used).
  4747   Naive rewrites:
  4748 
  4749     apl (n, op) =>>= curry op n
  4750     apr (op, m) =>>= fn n => op (n, m)
  4751 
  4752 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4753 provides a reasonably efficient light-weight implementation of sets as
  4754 lists.
  4755 
  4756 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4757 few new operations; existing lookup and update are now curried to
  4758 follow natural argument order (for use with fold etc.);
  4759 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4760 
  4761 * Pure/General: output via the Isabelle channels of
  4762 writeln/warning/error etc. is now passed through Output.output, with a
  4763 hook for arbitrary transformations depending on the print_mode
  4764 (cf. Output.add_mode -- the first active mode that provides a output
  4765 function wins).  Already formatted output may be embedded into further
  4766 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4767 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4768 accommodate easy composition of diagnostic messages etc.  Programmers
  4769 rarely need to care about Output.output or Output.raw at all, with
  4770 some notable exceptions: Output.output is required when bypassing the
  4771 standard channels (writeln etc.), or in token translations to produce
  4772 properly formatted results; Output.raw is required when capturing
  4773 already output material that will eventually be presented to the user
  4774 a second time.  For the default print mode, both Output.output and
  4775 Output.raw have no effect.
  4776 
  4777 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4778 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4779 cumulative results are displayed at the end of a batch session.
  4780 
  4781 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4782 replaced by File.platform_path and File.shell_path (with appropriate
  4783 hooks).  This provides a clean interface for unusual systems where the
  4784 internal and external process view of file names are different.
  4785 
  4786 * Pure: more efficient orders for basic syntactic entities: added
  4787 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4788 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4789 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4790 orders now -- potential INCOMPATIBILITY for code that depends on a
  4791 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4792 Library.sort_strings on result).
  4793 
  4794 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4795 fold_types traverse types/terms from left to right, observing natural
  4796 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4797 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4798 
  4799 * Pure: name spaces have been refined, with significant changes of the
  4800 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4801 to extern(_table).  The plain name entry path is superceded by a
  4802 general 'naming' context, which also includes the 'policy' to produce
  4803 a fully qualified name and external accesses of a fully qualified
  4804 name; NameSpace.extend is superceded by context dependent
  4805 Sign.declare_name.  Several theory and proof context operations modify
  4806 the naming context.  Especially note Theory.restore_naming and
  4807 ProofContext.restore_naming to get back to a sane state; note that
  4808 Theory.add_path is no longer sufficient to recover from
  4809 Theory.absolute_path in particular.
  4810 
  4811 * Pure: new flags short_names (default false) and unique_names
  4812 (default true) for controlling output of qualified names.  If
  4813 short_names is set, names are printed unqualified.  If unique_names is
  4814 reset, the name prefix is reduced to the minimum required to achieve
  4815 the original result when interning again, even if there is an overlap
  4816 with earlier declarations.
  4817 
  4818 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4819 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4820 (useful for printing error messages).  INCOMPATIBILITY.
  4821 
  4822 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4823 Theory.theory are now identified, referring to the universal
  4824 Context.theory (see Pure/context.ML).  Actual signature and theory
  4825 content is managed as theory data.  The old code and interfaces were
  4826 spread over many files and structures; the new arrangement introduces
  4827 considerable INCOMPATIBILITY to gain more clarity:
  4828 
  4829   Context -- theory management operations (name, identity, inclusion,
  4830     parents, ancestors, merge, etc.), plus generic theory data;
  4831 
  4832   Sign -- logical signature and syntax operations (declaring consts,
  4833     types, etc.), plus certify/read for common entities;
  4834 
  4835   Theory -- logical theory operations (stating axioms, definitions,
  4836     oracles), plus a copy of logical signature operations (consts,
  4837     types, etc.); also a few basic management operations (Theory.copy,
  4838     Theory.merge, etc.)
  4839 
  4840 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4841 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4842 for convenience -- they merely return the theory.
  4843 
  4844 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4845 
  4846 * Pure: the Isar proof context type is already defined early in Pure
  4847 as Context.proof (note that ProofContext.context and Proof.context are
  4848 aliases, where the latter is the preferred name).  This enables other
  4849 Isabelle components to refer to that type even before Isar is present.
  4850 
  4851 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4852 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4853 any of these kinds.  For example, Sign.intern typeK is now
  4854 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4855 Theory.hide_types.  Also note that former
  4856 Theory.hide_classes/types/consts are now
  4857 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4858 internalize their arguments!  INCOMPATIBILITY.
  4859 
  4860 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4861 datatype thmref (with constructors Name and NameSelection) instead of
  4862 plain string -- INCOMPATIBILITY;
  4863 
  4864 * Pure: cases produced by proof methods specify options, where NONE
  4865 means to remove case bindings -- INCOMPATIBILITY in
  4866 (RAW_)METHOD_CASES.
  4867 
  4868 * Pure: the following operations retrieve axioms or theorems from a
  4869 theory node or theory hierarchy, respectively:
  4870 
  4871   Theory.axioms_of: theory -> (string * term) list
  4872   Theory.all_axioms_of: theory -> (string * term) list
  4873   PureThy.thms_of: theory -> (string * thm) list
  4874   PureThy.all_thms_of: theory -> (string * thm) list
  4875 
  4876 * Pure: print_tac now outputs the goal through the trace channel.
  4877 
  4878 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4879 Reference Toplevel.debug (default false) controls detailed printing
  4880 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4881 controls execution profiling -- set to 1 for time and 2 for space
  4882 (both increase the runtime).
  4883 
  4884 * Isar session: The initial use of ROOT.ML is now always timed,
  4885 i.e. the log will show the actual process times, in contrast to the
  4886 elapsed wall-clock time that the outer shell wrapper produces.
  4887 
  4888 * Simplifier: improved handling of bound variables (nameless
  4889 representation, avoid allocating new strings).  Simprocs that invoke
  4890 the Simplifier recursively should use Simplifier.inherit_bounds to
  4891 avoid local name clashes.  Failure to do so produces warnings
  4892 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4893 for further details.
  4894 
  4895 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4896 bindings for all theorems stored within a given theory; this may help
  4897 in porting non-Isar theories to Isar ones, while keeping ML proof
  4898 scripts for the time being.
  4899 
  4900 * ML operator HTML.with_charset specifies the charset begin used for
  4901 generated HTML files.  For example:
  4902 
  4903   HTML.with_charset "utf-8" use_thy "Hebrew";
  4904   HTML.with_charset "utf-8" use_thy "Chinese";
  4905 
  4906 
  4907 *** System ***
  4908 
  4909 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4910 isabelle, isatool etc.).
  4911 
  4912 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4913 isatool doc, isatool mkdir, display_drafts etc.).
  4914 
  4915 * isatool usedir: option -f allows specification of the ML file to be
  4916 used by Isabelle; default is ROOT.ML.
  4917 
  4918 * New isatool version outputs the version identifier of the Isabelle
  4919 distribution being used.
  4920 
  4921 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4922 (containing Boolean satisfiability problems) into Isabelle/HOL
  4923 theories.
  4924 
  4925 
  4926 
  4927 New in Isabelle2004 (April 2004)
  4928 --------------------------------
  4929 
  4930 *** General ***
  4931 
  4932 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4933   Replaces linorder.ML.
  4934 
  4935 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4936   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4937   (\<a>...\<z>), are now considered normal letters, and can therefore
  4938   be used anywhere where an ASCII letter (a...zA...Z) has until
  4939   now. COMPATIBILITY: This obviously changes the parsing of some
  4940   terms, especially where a symbol has been used as a binder, say
  4941   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4942   as an identifier.  Fix it by inserting a space around former
  4943   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4944   existing theory and ML files.
  4945 
  4946 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4947 
  4948 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4949   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4950   a normal (but invisible) letter. For multiple letter subscripts repeat
  4951   \<^isub> like this: x\<^isub>1\<^isub>2.
  4952 
  4953 * Pure: There are now sub-/superscripts that can span more than one
  4954   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4955   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4956   superscript. The new control characters are not identifier parts.
  4957 
  4958 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4959   content of "..." to the latex file instead of \isacntrl... . The "..."
  4960   may consist of any printable characters excluding the end bracket >.
  4961 
  4962 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4963   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4964   declare constants "final", which prevents their being given a definition
  4965   later.  It is useful for constants whose behaviour is fixed axiomatically
  4966   rather than definitionally, such as the meta-logic connectives.
  4967 
  4968 * Pure: 'instance' now handles general arities with general sorts
  4969   (i.e. intersections of classes),
  4970 
  4971 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4972   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4973   It can be changed to alter the colors/layout of generated pages.
  4974 
  4975 
  4976 *** Isar ***
  4977 
  4978 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4979   cut_tac, subgoal_tac and thin_tac:
  4980   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4981     locales are no longer forced to write Isar proof scripts.
  4982     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4983     emulations.
  4984   - INCOMPATIBILITY: names of variables to be instantiated may no
  4985     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4986     This is consistent with the instantiation attribute "where".
  4987 
  4988 * Attributes "where" and "of":
  4989   - Now take type variables of instantiated theorem into account when reading
  4990     the instantiation string.  This fixes a bug that caused instantiated
  4991     theorems to have too special types in some circumstances.
  4992   - "where" permits explicit instantiations of type variables.
  4993 
  4994 * Calculation commands "moreover" and "also" no longer interfere with
  4995   current facts ("this"), admitting arbitrary combinations with "then"
  4996   and derived forms.
  4997 
  4998 * Locales:
  4999   - Goal statements involving the context element "includes" no longer
  5000     generate theorems with internal delta predicates (those ending on
  5001     "_axioms") in the premise.
  5002     Resolve particular premise with <locale>.intro to obtain old form.
  5003   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5004     specification and "includes" elements in goal statement.
  5005   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5006     [intro?] and [elim?] (respectively) by default.
  5007   - Experimental command for instantiation of locales in proof contexts:
  5008         instantiate <label>[<attrs>]: <loc>
  5009     Instantiates locale <loc> and adds all its theorems to the current context
  5010     taking into account their attributes.  Label and attrs are optional
  5011     modifiers, like in theorem declarations.  If present, names of
  5012     instantiated theorems are qualified with <label>, and the attributes
  5013     <attrs> are applied after any attributes these theorems might have already.
  5014       If the locale has assumptions, a chained fact of the form
  5015     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5016     are derived.  The command does not support old-style locales declared
  5017     with "locale (open)".
  5018       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5019 
  5020 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5021   (Isar) contexts.
  5022 
  5023 
  5024 *** HOL ***
  5025 
  5026 * Proof import: new image HOL4 contains the imported library from
  5027   the HOL4 system with about 2500 theorems. It is imported by
  5028   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5029   can be used like any other Isabelle image.  See
  5030   HOL/Import/HOL/README for more information.
  5031 
  5032 * Simplifier:
  5033   - Much improved handling of linear and partial orders.
  5034     Reasoners for linear and partial orders are set up for type classes
  5035     "linorder" and "order" respectively, and are added to the default simpset
  5036     as solvers.  This means that the simplifier can build transitivity chains
  5037     to solve goals from the assumptions.
  5038   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5039     of blast or auto after simplification become unnecessary because the goal
  5040     is solved by simplification already.
  5041 
  5042 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5043     all proved in axiomatic type classes for semirings, rings and fields.
  5044 
  5045 * Numerics:
  5046   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5047     now formalized using the Ring_and_Field theory mentioned above.
  5048   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5049     than before, because now they are set up once in a generic manner.
  5050   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5051     Look for the general versions in Ring_and_Field (and Power if they concern
  5052     exponentiation).
  5053 
  5054 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5055 
  5056 * Records:
  5057   - Record types are now by default printed with their type abbreviation
  5058     instead of the list of all field types. This can be configured via
  5059     the reference "print_record_type_abbr".
  5060   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5061     (not enabled by default).
  5062   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5063     EX x. x = sel r to True (not enabled by default).
  5064   - Tactic "record_split_simp_tac" to split and simplify records added.
  5065 
  5066 * 'specification' command added, allowing for definition by
  5067   specification.  There is also an 'ax_specification' command that
  5068   introduces the new constants axiomatically.
  5069 
  5070 * arith(_tac) is now able to generate counterexamples for reals as well.
  5071 
  5072 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5073 
  5074 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5075   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5076 
  5077 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5078   matrix theory to linear programming.
  5079 
  5080 * Unions and Intersections:
  5081   The latex output syntax of UN and INT has been changed
  5082   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5083   i.e. the index formulae has become a subscript.
  5084   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5085 
  5086 * Unions and Intersections over Intervals:
  5087   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5088   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5089   like in normal math, and corresponding versions for < and for intersection.
  5090 
  5091 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5092   lexicographic dictonary ordering has been added as "lexord".
  5093 
  5094 * ML: the legacy theory structures Int and List have been removed. They had
  5095   conflicted with ML Basis Library structures having the same names.
  5096 
  5097 * 'refute' command added to search for (finite) countermodels.  Only works
  5098   for a fragment of HOL.  The installation of an external SAT solver is
  5099   highly recommended.  See "HOL/Refute.thy" for details.
  5100 
  5101 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5102   formulae under an assignment of free variables to random values.
  5103   In contrast to 'refute', it can deal with inductive datatypes,
  5104   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5105   for examples.
  5106 
  5107 
  5108 *** HOLCF ***
  5109 
  5110 * Streams now come with concatenation and are part of the HOLCF image
  5111 
  5112 
  5113 
  5114 New in Isabelle2003 (May 2003)
  5115 ------------------------------
  5116 
  5117 *** General ***
  5118 
  5119 * Provers/simplifier:
  5120 
  5121   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5122     Assumptions are now subject to complete mutual simplification,
  5123     not just from left to right. The simplifier now preserves
  5124     the order of assumptions.
  5125 
  5126     Potential INCOMPATIBILITY:
  5127 
  5128     -- simp sometimes diverges where the old version did
  5129        not, e.g. invoking simp on the goal
  5130 
  5131         [| P (f x); y = x; f x = f y |] ==> Q
  5132 
  5133        now gives rise to the infinite reduction sequence
  5134 
  5135         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5136 
  5137        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5138        kind of problem.
  5139 
  5140     -- Tactics combining classical reasoner and simplification (such as auto)
  5141        are also affected by this change, because many of them rely on
  5142        simp. They may sometimes diverge as well or yield a different numbers
  5143        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5144        in case of problems. Sometimes subsequent calls to the classical
  5145        reasoner will fail because a preceeding call to the simplifier too
  5146        eagerly simplified the goal, e.g. deleted redundant premises.
  5147 
  5148   - The simplifier trace now shows the names of the applied rewrite rules
  5149 
  5150   - You can limit the number of recursive invocations of the simplifier
  5151     during conditional rewriting (where the simplifie tries to solve the
  5152     conditions before applying the rewrite rule):
  5153     ML "simp_depth_limit := n"
  5154     where n is an integer. Thus you can force termination where previously
  5155     the simplifier would diverge.
  5156 
  5157   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5158 
  5159   - No longer aborts on failed congruence proof.  Instead, the
  5160     congruence is ignored.
  5161 
  5162 * Pure: New generic framework for extracting programs from constructive
  5163   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5164   as HOL/Extraction for some case studies.
  5165 
  5166 * Pure: The main goal of the proof state is no longer shown by default, only
  5167 the subgoals. This behaviour is controlled by a new flag.
  5168    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5169 (ML: Proof.show_main_goal).
  5170 
  5171 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5172 rules whose conclusion matches subgoal 1:
  5173       PG menu: Isabelle/Isar -> Show me -> matching rules
  5174 The rules are ordered by how closely they match the subgoal.
  5175 In particular, rules that solve a subgoal outright are displayed first
  5176 (or rather last, the way they are printed).
  5177 (ML: ProofGeneral.print_intros())
  5178 
  5179 * Pure: New flag trace_unify_fail causes unification to print
  5180 diagnostic information (PG: in trace buffer) when it fails. This is
  5181 useful for figuring out why single step proofs like rule, erule or
  5182 assumption failed.
  5183 
  5184 * Pure: Locale specifications now produce predicate definitions
  5185 according to the body of text (covering assumptions modulo local
  5186 definitions); predicate "loc_axioms" covers newly introduced text,
  5187 while "loc" is cumulative wrt. all included locale expressions; the
  5188 latter view is presented only on export into the global theory
  5189 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5190 on the old view without predicates;
  5191 
  5192 * Pure: predefined locales "var" and "struct" are useful for sharing
  5193 parameters (as in CASL, for example); just specify something like
  5194 ``var x + var y + struct M'' as import;
  5195 
  5196 * Pure: improved thms_containing: proper indexing of facts instead of
  5197 raw theorems; check validity of results wrt. current name space;
  5198 include local facts of proof configuration (also covers active
  5199 locales), cover fixed variables in index; may use "_" in term
  5200 specification; an optional limit for the number of printed facts may
  5201 be given (the default is 40);
  5202 
  5203 * Pure: disallow duplicate fact bindings within new-style theory files
  5204 (batch-mode only);
  5205 
  5206 * Provers: improved induct method: assumptions introduced by case
  5207 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5208 the goal statement); "foo" still refers to all facts collectively;
  5209 
  5210 * Provers: the function blast.overloaded has been removed: all constants
  5211 are regarded as potentially overloaded, which improves robustness in exchange
  5212 for slight decrease in efficiency;
  5213 
  5214 * Provers/linorder: New generic prover for transitivity reasoning over
  5215 linear orders.  Note: this prover is not efficient!
  5216 
  5217 * Isar: preview of problems to finish 'show' now produce an error
  5218 rather than just a warning (in interactive mode);
  5219 
  5220 
  5221 *** HOL ***
  5222 
  5223 * arith(_tac)
  5224 
  5225  - Produces a counter example if it cannot prove a goal.
  5226    Note that the counter example may be spurious if the goal is not a formula
  5227    of quantifier-free linear arithmetic.
  5228    In ProofGeneral the counter example appears in the trace buffer.
  5229 
  5230  - Knows about div k and mod k where k is a numeral of type nat or int.
  5231 
  5232  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5233    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5234    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5235 
  5236 * simp's arithmetic capabilities have been enhanced a bit: it now
  5237 takes ~= in premises into account (by performing a case split);
  5238 
  5239 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5240 are distributed over a sum of terms;
  5241 
  5242 * New tactic "trans_tac" and method "trans" instantiate
  5243 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5244 "<=", "<" and "=").
  5245 
  5246 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5247 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5248 
  5249 * 'typedef' command has new option "open" to suppress the set
  5250 definition;
  5251 
  5252 * functions Min and Max on finite sets have been introduced (theory
  5253 Finite_Set);
  5254 
  5255 * attribute [symmetric] now works for relations as well; it turns
  5256 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5257 
  5258 * induct over a !!-quantified statement (say !!x1..xn):
  5259   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5260 
  5261 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5262 %x. None. Warning: empty_def now refers to the previously hidden definition
  5263 of the empty set.
  5264 
  5265 * Algebra: formalization of classical algebra.  Intended as base for
  5266 any algebraic development in Isabelle.  Currently covers group theory
  5267 (up to Sylow's theorem) and ring theory (Universal Property of
  5268 Univariate Polynomials).  Contributions welcome;
  5269 
  5270 * GroupTheory: deleted, since its material has been moved to Algebra;
  5271 
  5272 * Complex: new directory of the complex numbers with numeric constants,
  5273 nonstandard complex numbers, and some complex analysis, standard and
  5274 nonstandard (Jacques Fleuriot);
  5275 
  5276 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5277 
  5278 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5279 Fleuriot);
  5280 
  5281 * Real/HahnBanach: updated and adapted to locales;
  5282 
  5283 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5284 Gray and Kramer);
  5285 
  5286 * UNITY: added the Meier-Sanders theory of progress sets;
  5287 
  5288 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5289 as abstract algorithms, instantiated to the JVM;
  5290 
  5291 * Bali: Java source language formalization. Type system, operational
  5292 semantics, axiomatic semantics. Supported language features:
  5293 classes, interfaces, objects,virtual methods, static methods,
  5294 static/instance fields, arrays, access modifiers, definite
  5295 assignment, exceptions.
  5296 
  5297 
  5298 *** ZF ***
  5299 
  5300 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5301 universe, etc.);
  5302 
  5303 * Main ZF: virtually all theories converted to new-style format;
  5304 
  5305 
  5306 *** ML ***
  5307 
  5308 * Pure: Tactic.prove provides sane interface for internal proofs;
  5309 omits the infamous "standard" operation, so this is more appropriate
  5310 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5311 
  5312 * Pure: improved error reporting of simprocs;
  5313 
  5314 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5315 up simprocs;
  5316 
  5317 
  5318 *** Document preparation ***
  5319 
  5320 * uses \par instead of \\ for line breaks in theory text. This may
  5321 shift some page breaks in large documents. To get the old behaviour
  5322 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5323 
  5324 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5325 other packages
  5326 
  5327 * \<euro> now needs package babel/greek instead of marvosym (which
  5328 broke \Rightarrow)
  5329 
  5330 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5331 textcomp package)
  5332 
  5333 
  5334 
  5335 New in Isabelle2002 (March 2002)
  5336 --------------------------------
  5337 
  5338 *** Document preparation ***
  5339 
  5340 * greatly simplified document preparation setup, including more
  5341 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5342 instructive isatool mkdir; users should basically be able to get
  5343 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5344 users may run a separate document processing stage manually like this:
  5345 "isatool usedir -D output HOL Test && isatool document Test/output";
  5346 
  5347 * theory dependency graph may now be incorporated into documents;
  5348 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5349 with \includegraphics of LaTeX;
  5350 
  5351 * proper spacing of consecutive markup elements, especially text
  5352 blocks after section headings;
  5353 
  5354 * support bold style (for single symbols only), input syntax is like
  5355 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5356 
  5357 * \<bullet> is now output as bold \cdot by default, which looks much
  5358 better in printed text;
  5359 
  5360 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5361 note that these symbols are currently unavailable in Proof General /
  5362 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5363 
  5364 * isatool latex no longer depends on changed TEXINPUTS, instead
  5365 isatool document copies the Isabelle style files to the target
  5366 location;
  5367 
  5368 
  5369 *** Isar ***
  5370 
  5371 * Pure/Provers: improved proof by cases and induction;
  5372   - 'case' command admits impromptu naming of parameters (such as
  5373     "case (Suc n)");
  5374   - 'induct' method divinates rule instantiation from the inductive
  5375     claim; no longer requires excessive ?P bindings for proper
  5376     instantiation of cases;
  5377   - 'induct' method properly enumerates all possibilities of set/type
  5378     rules; as a consequence facts may be also passed through *type*
  5379     rules without further ado;
  5380   - 'induct' method now derives symbolic cases from the *rulified*
  5381     rule (before it used to rulify cases stemming from the internal
  5382     atomized version); this means that the context of a non-atomic
  5383     statement becomes is included in the hypothesis, avoiding the
  5384     slightly cumbersome show "PROP ?case" form;
  5385   - 'induct' may now use elim-style induction rules without chaining
  5386     facts, using ``missing'' premises from the goal state; this allows
  5387     rules stemming from inductive sets to be applied in unstructured
  5388     scripts, while still benefitting from proper handling of non-atomic
  5389     statements; NB: major inductive premises need to be put first, all
  5390     the rest of the goal is passed through the induction;
  5391   - 'induct' proper support for mutual induction involving non-atomic
  5392     rule statements (uses the new concept of simultaneous goals, see
  5393     below);
  5394   - append all possible rule selections, but only use the first
  5395     success (no backtracking);
  5396   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5397   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5398   - added 'print_induct_rules' (covered by help item in recent Proof
  5399     General versions);
  5400   - moved induct/cases attributes to Pure, methods to Provers;
  5401   - generic method setup instantiated for FOL and HOL;
  5402 
  5403 * Pure: support multiple simultaneous goal statements, for example
  5404 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5405 meta-level mechanism, this acts as if several individual goals had
  5406 been stated separately; in particular common proof methods need to be
  5407 repeated in order to cover all claims; note that a single elimination
  5408 step is *not* sufficient to establish the two conjunctions, so this
  5409 fails:
  5410 
  5411   assume "A & B" then have A and B ..   (*".." fails*)
  5412 
  5413 better use "obtain" in situations as above; alternative refer to
  5414 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5415 
  5416 * Pure: proper integration with ``locales''; unlike the original
  5417 version by Florian Kammller, Isar locales package high-level proof
  5418 contexts rather than raw logical ones (e.g. we admit to include
  5419 attributes everywhere); operations on locales include merge and
  5420 rename; support for implicit arguments (``structures''); simultaneous
  5421 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5422 some examples;
  5423 
  5424 * Pure: the following commands have been ``localized'', supporting a
  5425 target locale specification "(in name)": 'lemma', 'theorem',
  5426 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5427 stored both within the locale and at the theory level (exported and
  5428 qualified by the locale name);
  5429 
  5430 * Pure: theory goals may now be specified in ``long'' form, with
  5431 ad-hoc contexts consisting of arbitrary locale elements. for example
  5432 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5433 definitions may be given, too); the result is a meta-level rule with
  5434 the context elements being discharged in the obvious way;
  5435 
  5436 * Pure: new proof command 'using' allows to augment currently used
  5437 facts after a goal statement ('using' is syntactically analogous to
  5438 'apply', but acts on the goal's facts only); this allows chained facts
  5439 to be separated into parts given before and after a claim, as in
  5440 ``from a and b have C using d and e <proof>'';
  5441 
  5442 * Pure: renamed "antecedent" case to "rule_context";
  5443 
  5444 * Pure: new 'judgment' command records explicit information about the
  5445 object-logic embedding (used by several tools internally); no longer
  5446 use hard-wired "Trueprop";
  5447 
  5448 * Pure: added 'corollary' command;
  5449 
  5450 * Pure: fixed 'token_translation' command;
  5451 
  5452 * Pure: removed obsolete 'exported' attribute;
  5453 
  5454 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5455 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5456 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5457 
  5458 * Pure: method 'atomize' presents local goal premises as object-level
  5459 statements (atomic meta-level propositions); setup controlled via
  5460 rewrite rules declarations of 'atomize' attribute; example
  5461 application: 'induct' method with proper rule statements in improper
  5462 proof *scripts*;
  5463 
  5464 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5465 now consider the syntactic context of assumptions, giving a better
  5466 chance to get type-inference of the arguments right (this is
  5467 especially important for locales);
  5468 
  5469 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5470 mode;
  5471 
  5472 * Pure/obtain: the formal conclusion "thesis", being marked as
  5473 ``internal'', may no longer be reference directly in the text;
  5474 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5475 situations;
  5476 
  5477 * Pure: generic 'sym' attribute which declares a rule both as pure
  5478 'elim?' and for the 'symmetric' operation;
  5479 
  5480 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5481 text; the fixed correlation with particular command syntax has been
  5482 discontinued;
  5483 
  5484 * Pure: new method 'rules' is particularly well-suited for proof
  5485 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5486 but often produces more compact proof terms with less detours;
  5487 
  5488 * Pure/Provers/classical: simplified integration with pure rule
  5489 attributes and methods; the classical "intro?/elim?/dest?"
  5490 declarations coincide with the pure ones; the "rule" method no longer
  5491 includes classically swapped intros; "intro" and "elim" methods no
  5492 longer pick rules from the context; also got rid of ML declarations
  5493 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5494 INCOMPATIBILITY;
  5495 
  5496 * Provers/classical: attribute 'swapped' produces classical inversions
  5497 of introduction rules;
  5498 
  5499 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5500 rules instead of full simplifier context; 'iff' attribute handles
  5501 conditional rules;
  5502 
  5503 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5504 
  5505 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5506 "(permissive)" option to recover old behavior;
  5507 
  5508 * HOL: 'inductive' no longer features separate (collective) attributes
  5509 for 'intros' (was found too confusing);
  5510 
  5511 * HOL: properly declared induction rules less_induct and
  5512 wf_induct_rule;
  5513 
  5514 
  5515 *** HOL ***
  5516 
  5517 * HOL: moved over to sane numeral syntax; the new policy is as
  5518 follows:
  5519 
  5520   - 0 and 1 are polymorphic constants, which are defined on any
  5521   numeric type (nat, int, real etc.);
  5522 
  5523   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5524   binary representation internally;
  5525 
  5526   - type nat has special constructor Suc, and generally prefers Suc 0
  5527   over 1::nat and Suc (Suc 0) over 2::nat;
  5528 
  5529 This change may cause significant problems of INCOMPATIBILITY; here
  5530 are some hints on converting existing sources:
  5531 
  5532   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5533   entities, so expressions involving "-" (unary or binary minus) need
  5534   to be spaced properly;
  5535 
  5536   - existing occurrences of "1" may need to be constraint "1::nat" or
  5537   even replaced by Suc 0; similar for old "2";
  5538 
  5539   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5540 
  5541   - remove all special provisions on numerals in proofs;
  5542 
  5543 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5544 representation (depends on bin_arith_simps in the default context);
  5545 
  5546 * HOL: symbolic syntax for x^2 (numeral 2);
  5547 
  5548 * HOL: the class of all HOL types is now called "type" rather than
  5549 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5550 in axclass/classes, instance/arities, and (usually rare) occurrences
  5551 in typings (of consts etc.); internally the class is called
  5552 "HOL.type", ML programs should refer to HOLogic.typeS;
  5553 
  5554 * HOL/record package improvements:
  5555   - new derived operations "fields" to build a partial record section,
  5556     "extend" to promote a fixed record to a record scheme, and
  5557     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5558     declared as simp by default;
  5559   - shared operations ("more", "fields", etc.) now need to be always
  5560     qualified) --- potential INCOMPATIBILITY;
  5561   - removed "make_scheme" operations (use "make" with "extend") --
  5562     INCOMPATIBILITY;
  5563   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5564   - provides cases/induct rules for use with corresponding Isar
  5565     methods (for concrete records, record schemes, concrete more
  5566     parts, and schematic more parts -- in that order);
  5567   - internal definitions directly based on a light-weight abstract
  5568     theory of product types over typedef rather than datatype;
  5569 
  5570 * HOL: generic code generator for generating executable ML code from
  5571 specifications; specific support for HOL constructs such as inductive
  5572 datatypes and sets, as well as recursive functions; can be invoked
  5573 via 'generate_code' theory section;
  5574 
  5575 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5576 
  5577 * HOL: consolidated and renamed several theories.  In particular:
  5578         Ord.thy has been absorbed into HOL.thy
  5579         String.thy has been absorbed into List.thy
  5580 
  5581 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5582 (beware of argument permutation!);
  5583 
  5584 * HOL: linorder_less_split superseded by linorder_cases;
  5585 
  5586 * HOL/List: "nodups" renamed to "distinct";
  5587 
  5588 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5589 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5590   - Ex_def has changed, now need to use some_eq_ex
  5591 
  5592 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5593 in this (rare) case use:
  5594 
  5595   delSWrapper "split_all_tac"
  5596   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5597 
  5598 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5599 MAY FAIL;
  5600 
  5601 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5602 Isabelle's type classes, ^ on functions and relations has too general
  5603 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5604 necessary to attach explicit type constraints;
  5605 
  5606 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5607 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5608 renamed accordingly (eg "compI" -> "rel_compI").
  5609 
  5610 * HOL: syntax translations now work properly with numerals and records
  5611 expressions;
  5612 
  5613 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5614 of "lam" -- INCOMPATIBILITY;
  5615 
  5616 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5617 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5618 renamed "Product_Type.unit";
  5619 
  5620 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5621 
  5622 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5623 the "cases" method);
  5624 
  5625 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5626 Florian Kammller);
  5627 
  5628 * HOL/IMP: updated and converted to new-style theory format; several
  5629 parts turned into readable document, with proper Isar proof texts and
  5630 some explanations (by Gerwin Klein);
  5631 
  5632 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5633 
  5634 * HOL-Hyperreal is now a logic image;
  5635 
  5636 
  5637 *** HOLCF ***
  5638 
  5639 * Isar: consts/constdefs supports mixfix syntax for continuous
  5640 operations;
  5641 
  5642 * Isar: domain package adapted to new-style theory format, e.g. see
  5643 HOLCF/ex/Dnat.thy;
  5644 
  5645 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5646 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5647 lift.induct_tac, always use UU instead of Undef;
  5648 
  5649 * HOLCF/IMP: updated and converted to new-style theory;
  5650 
  5651 
  5652 *** ZF ***
  5653 
  5654 * Isar: proper integration of logic-specific tools and packages,
  5655 including theory commands '(co)inductive', '(co)datatype',
  5656 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5657 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5658 
  5659 * theory Main no longer includes AC; for the Axiom of Choice, base
  5660 your theory on Main_ZFC;
  5661 
  5662 * the integer library now covers quotients and remainders, with many
  5663 laws relating division to addition, multiplication, etc.;
  5664 
  5665 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5666 typeless version of the formalism;
  5667 
  5668 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5669 format;
  5670 
  5671 * ZF/Induct: new directory for examples of inductive definitions,
  5672 including theory Multiset for multiset orderings; converted to
  5673 new-style theory format;
  5674 
  5675 * ZF: many new theorems about lists, ordinals, etc.;
  5676 
  5677 
  5678 *** General ***
  5679 
  5680 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5681 variable proof controls level of detail: 0 = no proofs (only oracle
  5682 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5683 also ref manual for further ML interfaces;
  5684 
  5685 * Pure/axclass: removed obsolete ML interface
  5686 goal_subclass/goal_arity;
  5687 
  5688 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5689 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5690 separate tokens, so expressions involving minus need to be spaced
  5691 properly;
  5692 
  5693 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5694 rather than "infixl" or "infixr";
  5695 
  5696 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5697 sort constraint specifications in type inference; e.g. "x::_::foo"
  5698 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5699 type variable);
  5700 
  5701 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5702 control output of nested => (types); the default behavior is
  5703 "type_brackets";
  5704 
  5705 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5706 tokens into AST constants;
  5707 
  5708 * Pure/syntax: prefer later declarations of translations and print
  5709 translation functions; potential INCOMPATIBILITY: need to reverse
  5710 multiple declarations for same syntax element constant;
  5711 
  5712 * Pure/show_hyps reset by default (in accordance to existing Isar
  5713 practice);
  5714 
  5715 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5716 addSafter;
  5717 
  5718 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5719 as well;
  5720 
  5721 * system: tested support for MacOS X; should be able to get Isabelle +
  5722 Proof General to work in a plain Terminal after installing Poly/ML
  5723 (e.g. from the Isabelle distribution area) and GNU bash alone
  5724 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5725 support requires further installations, e.g. from
  5726 http://fink.sourceforge.net/);
  5727 
  5728 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5729 
  5730 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5731 of 40 MB), cf. ML_OPTIONS;
  5732 
  5733 * system: Proof General keywords specification is now part of the
  5734 Isabelle distribution (see etc/isar-keywords.el);
  5735 
  5736 * system: support for persistent Proof General sessions (refrain from
  5737 outdating all loaded theories on startup); user may create writable
  5738 logic images like this: ``isabelle -q HOL Test'';
  5739 
  5740 * system: smart selection of Isabelle process versus Isabelle
  5741 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5742 run both "isabelle" and "Isabelle" even if file names are badly
  5743 damaged (executable inspects the case of the first letter of its own
  5744 name); added separate "isabelle-process" and "isabelle-interface";
  5745 
  5746 * system: refrain from any attempt at filtering input streams; no
  5747 longer support ``8bit'' encoding of old isabelle font, instead proper
  5748 iso-latin characters may now be used; the related isatools
  5749 "symbolinput" and "nonascii" have disappeared as well;
  5750 
  5751 * system: removed old "xterm" interface (the print modes "xterm" and
  5752 "xterm_color" are still available for direct use in a suitable
  5753 terminal);
  5754 
  5755 
  5756 
  5757 New in Isabelle99-2 (February 2001)
  5758 -----------------------------------
  5759 
  5760 *** Overview of INCOMPATIBILITIES ***
  5761 
  5762 * HOL: please note that theories in the Library and elsewhere often use the
  5763 new-style (Isar) format; to refer to their theorems in an ML script you must
  5764 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5765 
  5766 * HOL: inductive package no longer splits induction rule aggressively,
  5767 but only as far as specified by the introductions given; the old
  5768 format may be recovered via ML function complete_split_rule or attribute
  5769 'split_rule (complete)';
  5770 
  5771 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5772 gfp_Tarski to gfp_unfold;
  5773 
  5774 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5775 
  5776 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5777 relation); infix "^^" has been renamed "``"; infix "``" has been
  5778 renamed "`"; "univalent" has been renamed "single_valued";
  5779 
  5780 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5781 operation;
  5782 
  5783 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5784 
  5785 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5786 
  5787 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5788 consequence, it is no longer monotonic wrt. the local goal context
  5789 (which is now passed through the inductive cases);
  5790 
  5791 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5792 \<gg> to \<ggreater>;
  5793 
  5794 
  5795 *** Document preparation ***
  5796 
  5797 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5798 available: are "it" for near math-mode best-style output, "sl" for
  5799 slanted text style, and "tt" for plain type-writer; if no
  5800 \isabellestyle command is given, output is according to slanted
  5801 type-writer);
  5802 
  5803 * support sub/super scripts (for single symbols only), input syntax is
  5804 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5805 
  5806 * some more standard symbols; see Appendix A of the system manual for
  5807 the complete list of symbols defined in isabellesym.sty;
  5808 
  5809 * improved isabelle style files; more abstract symbol implementation
  5810 (should now use \isamath{...} and \isatext{...} in custom symbol
  5811 definitions);
  5812 
  5813 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5814 state; Note that presentation of goal states does not conform to
  5815 actual human-readable proof documents.  Please do not include goal
  5816 states into document output unless you really know what you are doing!
  5817 
  5818 * proper indentation of antiquoted output with proportional LaTeX
  5819 fonts;
  5820 
  5821 * no_document ML operator temporarily disables LaTeX document
  5822 generation;
  5823 
  5824 * isatool unsymbolize tunes sources for plain ASCII communication;
  5825 
  5826 
  5827 *** Isar ***
  5828 
  5829 * Pure: Isar now suffers initial goal statements to contain unbound
  5830 schematic variables (this does not conform to actual readable proof
  5831 documents, due to unpredictable outcome and non-compositional proof
  5832 checking); users who know what they are doing may use schematic goals
  5833 for Prolog-style synthesis of proven results;
  5834 
  5835 * Pure: assumption method (an implicit finishing) now handles actual
  5836 rules as well;
  5837 
  5838 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5839 initial goal, declare "that" only as Pure intro (only for single
  5840 steps); the "that" rule assumption may now be involved in implicit
  5841 finishing, thus ".." becomes a feasible for trivial obtains;
  5842 
  5843 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5844 instance proofs may be performed by "..";
  5845 
  5846 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5847 statements as well;
  5848 
  5849 * Pure: more robust selection of calculational rules;
  5850 
  5851 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5852 rule (as well as the assumption rule);
  5853 
  5854 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5855 lemmas, using the graph browser tool;
  5856 
  5857 * Pure: predict failure of "show" in interactive mode;
  5858 
  5859 * Pure: 'thms_containing' now takes actual terms as arguments;
  5860 
  5861 * HOL: improved method 'induct' --- now handles non-atomic goals
  5862 (potential INCOMPATIBILITY); tuned error handling;
  5863 
  5864 * HOL: cases and induct rules now provide explicit hints about the
  5865 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5866 any remaining facts are inserted into the goal verbatim;
  5867 
  5868 * HOL: local contexts (aka cases) may now contain term bindings as
  5869 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5870 the result to be shown in each case;
  5871 
  5872 * HOL: added 'recdef_tc' command;
  5873 
  5874 * isatool convert assists in eliminating legacy ML scripts;
  5875 
  5876 
  5877 *** HOL ***
  5878 
  5879 * HOL/Library: a collection of generic theories to be used together
  5880 with main HOL; the theory loader path already includes this directory
  5881 by default; the following existing theories have been moved here:
  5882 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5883 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5884 
  5885 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5886 modelling and verification task performed in Isabelle/HOL +
  5887 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5888 
  5889 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5890 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5891 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5892 'domain', this makes the theory consistent with mathematical
  5893 literature;
  5894 
  5895 * HOL basics: added overloaded operations "inverse" and "divide"
  5896 (infix "/"), syntax for generic "abs" operation, generic summation
  5897 operator \<Sum>;
  5898 
  5899 * HOL/typedef: simplified package, provide more useful rules (see also
  5900 HOL/subset.thy);
  5901 
  5902 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5903 now expressed as a proper nested rule (old-style tactic scripts may
  5904 require atomize_strip_tac to cope with non-atomic premises);
  5905 
  5906 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5907 to "split_conv" (old name still available for compatibility);
  5908 
  5909 * HOL: improved concrete syntax for strings (e.g. allows translation
  5910 rules with string literals);
  5911 
  5912 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5913  and Fleuriot's mechanization of analysis, including the transcendental
  5914  functions for the reals;
  5915 
  5916 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5917 
  5918 
  5919 *** CTT ***
  5920 
  5921 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5922 "lam" is displayed as TWO lambda-symbols
  5923 
  5924 * CTT: theory Main now available, containing everything (that is, Bool
  5925 and Arith);
  5926 
  5927 
  5928 *** General ***
  5929 
  5930 * Pure: the Simplifier has been implemented properly as a derived rule
  5931 outside of the actual kernel (at last!); the overall performance
  5932 penalty in practical applications is about 50%, while reliability of
  5933 the Isabelle inference kernel has been greatly improved;
  5934 
  5935 * print modes "brackets" and "no_brackets" control output of nested =>
  5936 (types) and ==> (props); the default behaviour is "brackets";
  5937 
  5938 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5939 as assumptions as well;
  5940 
  5941 * system: support Poly/ML 4.0;
  5942 
  5943 * system: isatool install handles KDE version 1 or 2;
  5944 
  5945 
  5946 
  5947 New in Isabelle99-1 (October 2000)
  5948 ----------------------------------
  5949 
  5950 *** Overview of INCOMPATIBILITIES ***
  5951 
  5952 * HOL: simplification of natural numbers is much changed; to partly
  5953 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5954 issue the following ML commands:
  5955 
  5956   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5957   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5958 
  5959 * HOL: simplification no longer dives into case-expressions; this is
  5960 controlled by "t.weak_case_cong" for each datatype t;
  5961 
  5962 * HOL: nat_less_induct renamed to less_induct;
  5963 
  5964 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5965 fixsome to patch .thy and .ML sources automatically;
  5966 
  5967   select_equality  -> some_equality
  5968   select_eq_Ex     -> some_eq_ex
  5969   selectI2EX       -> someI2_ex
  5970   selectI2         -> someI2
  5971   selectI          -> someI
  5972   select1_equality -> some1_equality
  5973   Eps_sym_eq       -> some_sym_eq_trivial
  5974   Eps_eq           -> some_eq_trivial
  5975 
  5976 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5977 
  5978 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5979 instead);
  5980 
  5981 * HOL: the recursion equations generated by 'recdef' are now called
  5982 f.simps instead of f.rules;
  5983 
  5984 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5985 
  5986 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5987 sometimes be needed;
  5988 
  5989 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5990 
  5991 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5992 
  5993 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5994 product is now "<*>" instead of "Times"; the lexicographic product is
  5995 now "<*lex*>" instead of "**";
  5996 
  5997 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5998 of main HOL, but was unused); better use HOL's datatype package;
  5999 
  6000 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6001 the old syntax may be recovered as follows:
  6002 
  6003   syntax (symbols)
  6004     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6005       (infixl "\\<oplus>" 100)
  6006 
  6007 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6008 
  6009 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6010 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6011 internally;
  6012 
  6013 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6014 changed from A/r to A//r;
  6015 
  6016 * ZF: new treatment of arithmetic (nat & int) may break some old
  6017 proofs;
  6018 
  6019 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6020 rulify -> rule_format, elimify -> elim_format, ...);
  6021 
  6022 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6023 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6024 should have to change intro!! to intro? only); replaced "delrule" by
  6025 "rule del";
  6026 
  6027 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6028 
  6029 * Provers: strengthened force_tac by using new first_best_tac;
  6030 
  6031 * LaTeX document preparation: several changes of isabelle.sty (see
  6032 lib/texinputs);
  6033 
  6034 
  6035 *** Document preparation ***
  6036 
  6037 * formal comments (text blocks etc.) in new-style theories may now
  6038 contain antiquotations of thm/prop/term/typ/text to be presented
  6039 according to latex print mode; concrete syntax is like this:
  6040 @{term[show_types] "f(x) = a + x"};
  6041 
  6042 * isatool mkdir provides easy setup of Isabelle session directories,
  6043 including proper document sources;
  6044 
  6045 * generated LaTeX sources are now deleted after successful run
  6046 (isatool document -c); may retain a copy somewhere else via -D option
  6047 of isatool usedir;
  6048 
  6049 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6050 style files, achieving self-contained LaTeX sources and simplifying
  6051 LaTeX debugging;
  6052 
  6053 * old-style theories now produce (crude) LaTeX output as well;
  6054 
  6055 * browser info session directories are now self-contained (may be put
  6056 on WWW server seperately); improved graphs of nested sessions; removed
  6057 graph for 'all sessions';
  6058 
  6059 * several improvements in isabelle style files; \isabellestyle{it}
  6060 produces fake math mode output; \isamarkupheader is now \section by
  6061 default; see lib/texinputs/isabelle.sty etc.;
  6062 
  6063 
  6064 *** Isar ***
  6065 
  6066 * Isar/Pure: local results and corresponding term bindings are now
  6067 subject to Hindley-Milner polymorphism (similar to ML); this
  6068 accommodates incremental type-inference very nicely;
  6069 
  6070 * Isar/Pure: new derived language element 'obtain' supports
  6071 generalized existence reasoning;
  6072 
  6073 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6074 support accumulation of results, without applying any rules yet;
  6075 useful to collect intermediate results without explicit name
  6076 references, and for use with transitivity rules with more than 2
  6077 premises;
  6078 
  6079 * Isar/Pure: scalable support for case-analysis type proofs: new
  6080 'case' language element refers to local contexts symbolically, as
  6081 produced by certain proof methods; internally, case names are attached
  6082 to theorems as "tags";
  6083 
  6084 * Isar/Pure: theory command 'hide' removes declarations from
  6085 class/type/const name spaces;
  6086 
  6087 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6088 indicate potential overloading;
  6089 
  6090 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6091 
  6092 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6093 "{a,b,c}" instead of {a,b,c};
  6094 
  6095 * Isar/Pure now provides its own version of intro/elim/dest
  6096 attributes; useful for building new logics, but beware of confusion
  6097 with the version in Provers/classical;
  6098 
  6099 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6100 case name 'antecedent';
  6101 
  6102 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6103 to the current context is now done automatically);
  6104 
  6105 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6106 for definining proof methods in ML;
  6107 
  6108 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6109 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6110 most cases, one should have to change intro!! to intro? only);
  6111 replaced "delrule" by "rule del";
  6112 
  6113 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6114 'symmetric' attribute (the latter supercedes [RS sym]);
  6115 
  6116 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6117 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6118 well (including splits);
  6119 
  6120 * Isar/Provers: Simplifier and Classical methods now support all kind
  6121 of modifiers used in the past, including 'cong', 'iff', etc.
  6122 
  6123 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6124 of Simplifier and Classical reasoner);
  6125 
  6126 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6127 now support named cases; major packages (inductive, datatype, primrec,
  6128 recdef) support case names and properly name parameters;
  6129 
  6130 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6131 monotonicity conditions are extracted to be proven at end of
  6132 calculations;
  6133 
  6134 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6135 method anyway;
  6136 
  6137 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6138 split_if split_if_asm; datatype package provides theorems foo.splits =
  6139 foo.split foo.split_asm for each datatype;
  6140 
  6141 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6142 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6143 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6144 use "(cases (simplified))" method in proper proof texts);
  6145 
  6146 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6147 
  6148 * Isar: names of theorems etc. may be natural numbers as well;
  6149 
  6150 * Isar: 'pr' command: optional arguments for goals_limit and
  6151 ProofContext.prems_limit; no longer prints theory contexts, but only
  6152 proof states;
  6153 
  6154 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6155 additional print modes to be specified; e.g. "pr(latex)" will print
  6156 proof state according to the Isabelle LaTeX style;
  6157 
  6158 * Isar: improved support for emulating tactic scripts, including proof
  6159 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6160 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6161 (for HOL datatypes);
  6162 
  6163 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6164 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6165 'proof method scripts' have to be in depth-first order;
  6166 
  6167 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6168 
  6169 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6170 should instead use individual commands for printing items
  6171 (print_commands, print_methods etc.);
  6172 
  6173 * Isar: added 'nothing' --- the empty list of theorems;
  6174 
  6175 
  6176 *** HOL ***
  6177 
  6178 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6179 corresponding virtual machine and a specification of its bytecode
  6180 verifier and a lightweight bytecode verifier, including proofs of
  6181 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6182 Cornelia Pusch (see also the homepage of project Bali at
  6183 http://isabelle.in.tum.de/Bali/);
  6184 
  6185 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6186 Clemens Ballarin;
  6187 
  6188 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6189 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6190 Rasmussen;
  6191 
  6192 * HOL/Lattice: fundamental concepts of lattice theory and order
  6193 structures, including duals, properties of bounds versus algebraic
  6194 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6195 Theorem for complete lattices etc.; may also serve as a demonstration
  6196 for abstract algebraic reasoning using axiomatic type classes, and
  6197 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6198 
  6199 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6200 von Oheimb;
  6201 
  6202 * HOL/IMPP: extension of IMP with local variables and mutually
  6203 recursive procedures, by David von Oheimb;
  6204 
  6205 * HOL/Lambda: converted into new-style theory and document;
  6206 
  6207 * HOL/ex/Multiquote: example of multiple nested quotations and
  6208 anti-quotations -- basically a generalized version of de-Bruijn
  6209 representation; very useful in avoiding lifting of operations;
  6210 
  6211 * HOL/record: added general record equality rule to simpset; fixed
  6212 select-update simplification procedure to handle extended records as
  6213 well; admit "r" as field name;
  6214 
  6215 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6216 other numeric types and also as the identity of groups, rings, etc.;
  6217 
  6218 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6219 Types nat and int belong to this axclass;
  6220 
  6221 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6222    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6223    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6224   two terms #m*u and #n*u are replaced by #(m+n)*u
  6225     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6226   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6227     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6228 
  6229 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6230 powerful prover for predicate logic but knows nothing of clasets; see
  6231 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6232 
  6233 * HOL: new version of "case_tac" subsumes both boolean case split and
  6234 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer