NEWS
author wenzelm
Fri Sep 03 22:36:16 2010 +0200 (2010-09-03)
changeset 39126 ee117c5b3b75
parent 39125 f45d332a90e3
child 39128 93a7365fb4ee
permissions -rw-r--r--
configuration options Syntax.ambiguity_enabled (inverse of former Syntax.ambiguity_is_error), Syntax.ambiguity_level (with Isar attribute "syntax_ambiguity_level"), Syntax.ambiguity_limit;
     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   show_question_marks           show_question_marks
    34   show_consts                   show_consts
    35 
    36   Syntax.ambiguity_level        syntax_ambiguity_level
    37 
    38   Goal_Display.goals_limit      goals_limit
    39   Goal_Display.show_main_goal   show_main_goal
    40 
    41   Thy_Output.display            thy_output_display
    42   Thy_Output.quotes             thy_output_quotes
    43   Thy_Output.indent             thy_output_indent
    44   Thy_Output.source             thy_output_source
    45   Thy_Output.break              thy_output_break
    46 
    47 Note that corresponding "..._default" references in ML may be only
    48 changed globally at the ROOT session setup, but *not* within a theory.
    49 
    50 
    51 *** Pure ***
    52 
    53 * Interpretation command 'interpret' accepts a list of equations like
    54 'interpretation' does.
    55 
    56 * Diagnostic command 'print_interps' prints interpretations in proofs
    57 in addition to interpretations in theories.
    58 
    59 * Discontinued obsolete 'global' and 'local' commands to manipulate
    60 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    61 Sign.root_path and Sign.local_path may be applied directly where this
    62 feature is still required for historical reasons.
    63 
    64 
    65 *** HOL ***
    66 
    67 * Renamed class eq and constant eq (for code generation) to class equal
    68 and constant equal, plus renaming of related facts and various tuning.
    69 INCOMPATIBILITY.
    70 
    71 * Scala (2.8 or higher) has been added to the target languages of
    72 the code generator.
    73 
    74 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    75 
    76 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    77 canonical names for instance definitions for functions; various improvements.
    78 INCOMPATIBILITY.
    79 
    80 * Records: logical foundation type for records do not carry a '_type' suffix
    81 any longer.  INCOMPATIBILITY.
    82 
    83 * Code generation for records: more idiomatic representation of record types.
    84 Warning: records are not covered by ancient SML code generation any longer.
    85 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    86 helps to succeed then:
    87 
    88   record 'a foo = ...
    89   ...
    90   rep_datatype foo_ext ...
    91 
    92 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    93 INCOMPATIBILITY.
    94 
    95 * Quickcheck in locales considers interpretations of that locale for
    96 counter example search.
    97 
    98 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    99 in Library/State_Monad has been changed to avoid ambiguities.
   100 INCOMPATIBILITY.
   101 
   102 * Code generator: export_code without explicit file declaration prints
   103 to standard output.  INCOMPATIBILITY.
   104 
   105 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   106 respectively.  INCOMPATIBILITY.
   107 
   108 * Constant "split" has been merged with constant "prod_case";  names
   109 of ML functions, facts etc. involving split have been retained so far,
   110 though.  INCOMPATIBILITY.
   111 
   112 * Dropped old infix syntax "mem" for List.member;  use "in set"
   113 instead.  INCOMPATIBILITY.
   114 
   115 * Refactoring of code-generation specific operations in List.thy
   116 
   117   constants
   118     null ~> List.null
   119 
   120   facts
   121     mem_iff ~> member_def
   122     null_empty ~> null_def
   123 
   124 INCOMPATIBILITY.  Note that these were not suppossed to be used
   125 regularly unless for striking reasons;  their main purpose was code
   126 generation.
   127 
   128 * Some previously unqualified names have been qualified:
   129 
   130   types
   131     bool ~> HOL.bool
   132     nat ~> Nat.nat
   133 
   134   constants
   135     Trueprop ~> HOL.Trueprop
   136     True ~> HOL.True
   137     False ~> HOL.False
   138     op & ~> HOL.conj
   139     op | ~> HOL.disj
   140     op --> ~> HOL.implies
   141     op = ~> HOL.eq
   142     Not ~> HOL.Not
   143     The ~> HOL.The
   144     All ~> HOL.All
   145     Ex ~> HOL.Ex
   146     Ex1 ~> HOL.Ex1
   147     Let ~> HOL.Let
   148     If ~> HOL.If
   149     Ball ~> Set.Ball
   150     Bex ~> Set.Bex
   151     Suc ~> Nat.Suc
   152     Pair ~> Product_Type.Pair
   153     fst ~> Product_Type.fst
   154     snd ~> Product_Type.snd
   155     curry ~> Product_Type.curry
   156     op : ~> Set.member
   157     Collect ~> Set.Collect
   158 
   159 INCOMPATIBILITY.
   160 
   161 * Removed simplifier congruence rule of "prod_case", as has for long
   162 been the case with "split".  INCOMPATIBILITY.
   163 
   164 * Datatype package: theorems generated for executable equality
   165 (class eq) carry proper names and are treated as default code
   166 equations.
   167 
   168 * List.thy: use various operations from the Haskell prelude when
   169 generating Haskell code.
   170 
   171 * code_simp.ML and method code_simp: simplification with rules determined
   172 by code generator.
   173 
   174 * code generator: do not print function definitions for case
   175 combinators any longer.
   176 
   177 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   178 theorems are now stated in terms of euclidean spaces instead of finite
   179 cartesian products.
   180 
   181   types
   182     real ^ 'n ~>  'a::real_vector
   183               ~>  'a::euclidean_space
   184               ~>  'a::ordered_euclidean_space
   185         (depends on your needs)
   186 
   187   constants
   188      _ $ _        ~> _ $$ _
   189      \<chi> x. _  ~> \<chi>\<chi> x. _
   190      CARD('n)     ~> DIM('a)
   191 
   192 Also note that the indices are now natural numbers and not from some finite
   193 type. Finite cartesian products of euclidean spaces, products of euclidean
   194 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   195 
   196 INCOMPATIBILITY.
   197 
   198 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   199 as value for measures. Introduces Lebesgue Measure based on the integral in
   200 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   201 spaces.
   202 
   203  INCOMPATIBILITY.
   204 
   205 * Inductive package: offers new command "inductive_simps" to automatically
   206 derive instantiated and simplified equations for inductive predicates,
   207 similar to inductive_cases.
   208 
   209 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". surj_on is a
   210 generalization of surj, and "surj f" is now a abbreviation of "surj_on f UNIV".
   211 The theorems bij_def and surj_def are unchanged.
   212 
   213 *** FOL ***
   214 
   215 * All constant names are now qualified.  INCOMPATIBILITY.
   216 
   217 
   218 *** ZF ***
   219 
   220 * All constant names are now qualified.  INCOMPATIBILITY.
   221 
   222 
   223 *** ML ***
   224 
   225 * Configuration option show_question_marks only affects regular pretty
   226 printing of types and terms, not raw Term.string_of_vname.
   227 
   228 * ML structure Unsynchronized never opened, not even in Isar
   229 interaction mode as before.  Old Unsynchronized.set etc. have been
   230 discontinued -- use plain := instead.  This should be *rare* anyway,
   231 since modern tools always work via official context data, notably
   232 configuration options.
   233 
   234 * ML antiquotations @{theory} and @{theory_ref} refer to named
   235 theories from the ancestry of the current context, not any accidental
   236 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   237 change in semantics.
   238 
   239 
   240 *** System ***
   241 
   242 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   243 
   244 
   245 
   246 New in Isabelle2009-2 (June 2010)
   247 ---------------------------------
   248 
   249 *** General ***
   250 
   251 * Authentic syntax for *all* logical entities (type classes, type
   252 constructors, term constants): provides simple and robust
   253 correspondence between formal entities and concrete syntax.  Within
   254 the parse tree / AST representations, "constants" are decorated by
   255 their category (class, type, const) and spelled out explicitly with
   256 their full internal name.
   257 
   258 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   259 and translations (translation rules and translation functions in ML).
   260 Some hints on upgrading:
   261 
   262   - Many existing uses of 'syntax' and 'translations' can be replaced
   263     by more modern 'type_notation', 'notation' and 'abbreviation',
   264     which are independent of this issue.
   265 
   266   - 'translations' require markup within the AST; the term syntax
   267     provides the following special forms:
   268 
   269       CONST c   -- produces syntax version of constant c from context
   270       XCONST c  -- literally c, checked as constant from context
   271       c         -- literally c, if declared by 'syntax'
   272 
   273     Plain identifiers are treated as AST variables -- occasionally the
   274     system indicates accidental variables via the error "rhs contains
   275     extra variables".
   276 
   277     Type classes and type constructors are marked according to their
   278     concrete syntax.  Some old translations rules need to be written
   279     for the "type" category, using type constructor application
   280     instead of pseudo-term application of the default category
   281     "logic".
   282 
   283   - 'parse_translation' etc. in ML may use the following
   284     antiquotations:
   285 
   286       @{class_syntax c}   -- type class c within parse tree / AST
   287       @{term_syntax c}    -- type constructor c within parse tree / AST
   288       @{const_syntax c}   -- ML version of "CONST c" above
   289       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   290 
   291   - Literal types within 'typed_print_translations', i.e. those *not*
   292     represented as pseudo-terms are represented verbatim.  Use @{class
   293     c} or @{type_name c} here instead of the above syntax
   294     antiquotations.
   295 
   296 Note that old non-authentic syntax was based on unqualified base
   297 names, so all of the above "constant" names would coincide.  Recall
   298 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   299 diagnose syntax problems.
   300 
   301 * Type constructors admit general mixfix syntax, not just infix.
   302 
   303 * Concrete syntax may be attached to local entities without a proof
   304 body, too.  This works via regular mixfix annotations for 'fix',
   305 'def', 'obtain' etc. or via the explicit 'write' command, which is
   306 similar to the 'notation' command in theory specifications.
   307 
   308 * Discontinued unnamed infix syntax (legacy feature for many years) --
   309 need to specify constant name and syntax separately.  Internal ML
   310 datatype constructors have been renamed from InfixName to Infix etc.
   311 Minor INCOMPATIBILITY.
   312 
   313 * Schematic theorem statements need to be explicitly markup as such,
   314 via commands 'schematic_lemma', 'schematic_theorem',
   315 'schematic_corollary'.  Thus the relevance of the proof is made
   316 syntactically clear, which impacts performance in a parallel or
   317 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   318 
   319 * Use of cumulative prems via "!" in some proof methods has been
   320 discontinued (old legacy feature).
   321 
   322 * References 'trace_simp' and 'debug_simp' have been replaced by
   323 configuration options stored in the context. Enabling tracing (the
   324 case of debugging is similar) in proofs works via
   325 
   326   using [[trace_simp = true]]
   327 
   328 Tracing is then active for all invocations of the simplifier in
   329 subsequent goal refinement steps. Tracing may also still be enabled or
   330 disabled via the ProofGeneral settings menu.
   331 
   332 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   333 'hide_fact' replace the former 'hide' KIND command.  Minor
   334 INCOMPATIBILITY.
   335 
   336 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   337 more efficient than combinations with -q1 or -q2.
   338 
   339 
   340 *** Pure ***
   341 
   342 * Proofterms record type-class reasoning explicitly, using the
   343 "unconstrain" operation internally.  This eliminates all sort
   344 constraints from a theorem and proof, introducing explicit
   345 OFCLASS-premises.  On the proof term level, this operation is
   346 automatically applied at theorem boundaries, such that closed proofs
   347 are always free of sort constraints.  INCOMPATIBILITY for tools that
   348 inspect proof terms.
   349 
   350 * Local theory specifications may depend on extra type variables that
   351 are not present in the result type -- arguments TYPE('a) :: 'a itself
   352 are added internally.  For example:
   353 
   354   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   355 
   356 * Predicates of locales introduced by classes carry a mandatory
   357 "class" prefix.  INCOMPATIBILITY.
   358 
   359 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   360 
   361 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   362 'class' instead.
   363 
   364 * Command 'code_reflect' allows to incorporate generated ML code into
   365 runtime environment; replaces immature code_datatype antiquotation.
   366 INCOMPATIBILITY.
   367 
   368 * Code generator: simple concept for abstract datatypes obeying
   369 invariants.
   370 
   371 * Code generator: details of internal data cache have no impact on the
   372 user space functionality any longer.
   373 
   374 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   375 subgoals.  This is more appropriate for interpretations with 'where'.
   376 INCOMPATIBILITY.
   377 
   378 * Command 'example_proof' opens an empty proof body.  This allows to
   379 experiment with Isar, without producing any persistent result.
   380 
   381 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   382 within a local theory context, with explicit checking of the
   383 constructors involved (in contrast to the raw 'syntax' versions).
   384 
   385 * Commands 'types' and 'typedecl' now work within a local theory
   386 context -- without introducing dependencies on parameters or
   387 assumptions, which is not possible in Isabelle/Pure.
   388 
   389 * Command 'defaultsort' has been renamed to 'default_sort', it works
   390 within a local theory context.  Minor INCOMPATIBILITY.
   391 
   392 
   393 *** HOL ***
   394 
   395 * Command 'typedef' now works within a local theory context -- without
   396 introducing dependencies on parameters or assumptions, which is not
   397 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   398 contain multiple interpretations of local typedefs (with different
   399 non-emptiness proofs), even in a global theory context.
   400 
   401 * New package for quotient types.  Commands 'quotient_type' and
   402 'quotient_definition' may be used for defining types and constants by
   403 quotient constructions.  An example is the type of integers created by
   404 quotienting pairs of natural numbers:
   405 
   406   fun
   407     intrel :: "(nat * nat) => (nat * nat) => bool"
   408   where
   409     "intrel (x, y) (u, v) = (x + v = u + y)"
   410 
   411   quotient_type int = "nat * nat" / intrel
   412     by (auto simp add: equivp_def expand_fun_eq)
   413 
   414   quotient_definition
   415     "0::int" is "(0::nat, 0::nat)"
   416 
   417 The method "lifting" can be used to lift of theorems from the
   418 underlying "raw" type to the quotient type.  The example
   419 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   420 construction and provides a reasoning infrastructure for finite sets.
   421 
   422 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   423 clash with new theory Quotient in Main HOL.
   424 
   425 * Moved the SMT binding into the main HOL session, eliminating
   426 separate HOL-SMT session.
   427 
   428 * List membership infix mem operation is only an input abbreviation.
   429 INCOMPATIBILITY.
   430 
   431 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   432 for future developements; former Library/Word.thy is still present in
   433 the AFP entry RSAPPS.
   434 
   435 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   436 longer shadowed.  INCOMPATIBILITY.
   437 
   438 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   439 INCOMPATIBILITY.
   440 
   441 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   442 INCOMPATIBILITY.
   443 
   444 * Dropped normalizing_semiring etc; use the facts in semiring classes
   445 instead.  INCOMPATIBILITY.
   446 
   447 * Dropped several real-specific versions of lemmas about floor and
   448 ceiling; use the generic lemmas from theory "Archimedean_Field"
   449 instead.  INCOMPATIBILITY.
   450 
   451   floor_number_of_eq         ~> floor_number_of
   452   le_floor_eq_number_of      ~> number_of_le_floor
   453   le_floor_eq_zero           ~> zero_le_floor
   454   le_floor_eq_one            ~> one_le_floor
   455   floor_less_eq_number_of    ~> floor_less_number_of
   456   floor_less_eq_zero         ~> floor_less_zero
   457   floor_less_eq_one          ~> floor_less_one
   458   less_floor_eq_number_of    ~> number_of_less_floor
   459   less_floor_eq_zero         ~> zero_less_floor
   460   less_floor_eq_one          ~> one_less_floor
   461   floor_le_eq_number_of      ~> floor_le_number_of
   462   floor_le_eq_zero           ~> floor_le_zero
   463   floor_le_eq_one            ~> floor_le_one
   464   floor_subtract_number_of   ~> floor_diff_number_of
   465   floor_subtract_one         ~> floor_diff_one
   466   ceiling_number_of_eq       ~> ceiling_number_of
   467   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   468   ceiling_le_zero_eq         ~> ceiling_le_zero
   469   ceiling_le_eq_one          ~> ceiling_le_one
   470   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   471   less_ceiling_eq_zero       ~> zero_less_ceiling
   472   less_ceiling_eq_one        ~> one_less_ceiling
   473   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   474   ceiling_less_eq_zero       ~> ceiling_less_zero
   475   ceiling_less_eq_one        ~> ceiling_less_one
   476   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   477   le_ceiling_eq_zero         ~> zero_le_ceiling
   478   le_ceiling_eq_one          ~> one_le_ceiling
   479   ceiling_subtract_number_of ~> ceiling_diff_number_of
   480   ceiling_subtract_one       ~> ceiling_diff_one
   481 
   482 * Theory "Finite_Set": various folding_XXX locales facilitate the
   483 application of the various fold combinators on finite sets.
   484 
   485 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   486 provides abstract red-black tree type which is backed by "RBT_Impl" as
   487 implementation.  INCOMPATIBILTY.
   488 
   489 * Theory Library/Coinductive_List has been removed -- superseded by
   490 AFP/thys/Coinductive.
   491 
   492 * Theory PReal, including the type "preal" and related operations, has
   493 been removed.  INCOMPATIBILITY.
   494 
   495 * Real: new development using Cauchy Sequences.
   496 
   497 * Split off theory "Big_Operators" containing setsum, setprod,
   498 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   499 
   500 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   501 "Int" etc.  INCOMPATIBILITY.
   502 
   503 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   504 
   505 * New set of rules "ac_simps" provides combined assoc / commute
   506 rewrites for all interpretations of the appropriate generic locales.
   507 
   508 * Renamed theory "OrderedGroup" to "Groups" and split theory
   509 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   510 appropriate and more consistent names suitable for name prefixes
   511 within the HOL theories.  INCOMPATIBILITY.
   512 
   513 * Some generic constants have been put to appropriate theories:
   514   - less_eq, less: Orderings
   515   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   516   - inverse, divide: Rings
   517 INCOMPATIBILITY.
   518 
   519 * More consistent naming of type classes involving orderings (and
   520 lattices):
   521 
   522     lower_semilattice                   ~> semilattice_inf
   523     upper_semilattice                   ~> semilattice_sup
   524 
   525     dense_linear_order                  ~> dense_linorder
   526 
   527     pordered_ab_group_add               ~> ordered_ab_group_add
   528     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   529     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   530     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   531     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   532     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   533     pordered_cancel_semiring            ~> ordered_cancel_semiring
   534     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   535     pordered_comm_ring                  ~> ordered_comm_ring
   536     pordered_comm_semiring              ~> ordered_comm_semiring
   537     pordered_ring                       ~> ordered_ring
   538     pordered_ring_abs                   ~> ordered_ring_abs
   539     pordered_semiring                   ~> ordered_semiring
   540 
   541     ordered_ab_group_add                ~> linordered_ab_group_add
   542     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   543     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   544     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   545     ordered_field                       ~> linordered_field
   546     ordered_field_no_lb                 ~> linordered_field_no_lb
   547     ordered_field_no_ub                 ~> linordered_field_no_ub
   548     ordered_field_dense_linear_order    ~> dense_linordered_field
   549     ordered_idom                        ~> linordered_idom
   550     ordered_ring                        ~> linordered_ring
   551     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   552     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   553     ordered_ring_strict                 ~> linordered_ring_strict
   554     ordered_semidom                     ~> linordered_semidom
   555     ordered_semiring                    ~> linordered_semiring
   556     ordered_semiring_1                  ~> linordered_semiring_1
   557     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   558     ordered_semiring_strict             ~> linordered_semiring_strict
   559 
   560   The following slightly odd type classes have been moved to a
   561   separate theory Library/Lattice_Algebras:
   562 
   563     lordered_ab_group_add               ~> lattice_ab_group_add
   564     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   565     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   566     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   567     lordered_ring                       ~> lattice_ring
   568 
   569 INCOMPATIBILITY.
   570 
   571 * Refined field classes:
   572   - classes division_ring_inverse_zero, field_inverse_zero,
   573     linordered_field_inverse_zero include rule inverse 0 = 0 --
   574     subsumes former division_by_zero class;
   575   - numerous lemmas have been ported from field to division_ring.
   576 INCOMPATIBILITY.
   577 
   578 * Refined algebra theorem collections:
   579   - dropped theorem group group_simps, use algebra_simps instead;
   580   - dropped theorem group ring_simps, use field_simps instead;
   581   - proper theorem collection field_simps subsumes former theorem
   582     groups field_eq_simps and field_simps;
   583   - dropped lemma eq_minus_self_iff which is a duplicate for
   584     equal_neg_zero.
   585 INCOMPATIBILITY.
   586 
   587 * Theory Finite_Set and List: some lemmas have been generalized from
   588 sets to lattices:
   589 
   590   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   591   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   592   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   593   union_Union_fold_union        ~> sup_Sup_fold_sup
   594   Inter_fold_inter              ~> Inf_fold_inf
   595   Union_fold_union              ~> Sup_fold_sup
   596   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   597   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   598   INTER_fold_inter              ~> INFI_fold_inf
   599   UNION_fold_union              ~> SUPR_fold_sup
   600 
   601 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   602 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   603 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   604 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   605 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   606 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   607 
   608 * Reorganized theory Multiset: swapped notation of pointwise and
   609 multiset order:
   610 
   611   - pointwise ordering is instance of class order with standard syntax
   612     <= and <;
   613   - multiset ordering has syntax <=# and <#; partial order properties
   614     are provided by means of interpretation with prefix
   615     multiset_order;
   616   - less duplication, less historical organization of sections,
   617     conversion from associations lists to multisets, rudimentary code
   618     generation;
   619   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   620     if needed.
   621 
   622 Renamed:
   623 
   624   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   625   multi_count_ext  ~>  multiset_ext
   626   diff_union_inverse2  ~>  diff_union_cancelR
   627 
   628 INCOMPATIBILITY.
   629 
   630 * Theory Permutation: replaced local "remove" by List.remove1.
   631 
   632 * Code generation: ML and OCaml code is decorated with signatures.
   633 
   634 * Theory List: added transpose.
   635 
   636 * Library/Nat_Bijection.thy is a collection of bijective functions
   637 between nat and other types, which supersedes the older libraries
   638 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   639 
   640   Constants:
   641   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   642   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   643   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   644   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   645   Countable.pair_encode           ~> prod_encode
   646   NatIso.prod2nat                 ~> prod_encode
   647   NatIso.nat2prod                 ~> prod_decode
   648   NatIso.sum2nat                  ~> sum_encode
   649   NatIso.nat2sum                  ~> sum_decode
   650   NatIso.list2nat                 ~> list_encode
   651   NatIso.nat2list                 ~> list_decode
   652   NatIso.set2nat                  ~> set_encode
   653   NatIso.nat2set                  ~> set_decode
   654 
   655   Lemmas:
   656   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   657   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   658   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   659   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   660   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   661   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   662   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   663   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   664   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   665   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   666   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   667   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   668   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   669 
   670 * Sledgehammer:
   671   - Renamed ATP commands:
   672     atp_info     ~> sledgehammer running_atps
   673     atp_kill     ~> sledgehammer kill_atps
   674     atp_messages ~> sledgehammer messages
   675     atp_minimize ~> sledgehammer minimize
   676     print_atps   ~> sledgehammer available_atps
   677     INCOMPATIBILITY.
   678   - Added user's manual ("isabelle doc sledgehammer").
   679   - Added option syntax and "sledgehammer_params" to customize
   680     Sledgehammer's behavior.  See the manual for details.
   681   - Modified the Isar proof reconstruction code so that it produces
   682     direct proofs rather than proofs by contradiction.  (This feature
   683     is still experimental.)
   684   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   685     full-typed mode.
   686   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   687 
   688 * Nitpick:
   689   - Added and implemented "binary_ints" and "bits" options.
   690   - Added "std" option and implemented support for nonstandard models.
   691   - Added and implemented "finitize" option to improve the precision
   692     of infinite datatypes based on a monotonicity analysis.
   693   - Added support for quotient types.
   694   - Added support for "specification" and "ax_specification"
   695     constructs.
   696   - Added support for local definitions (for "function" and
   697     "termination" proofs).
   698   - Added support for term postprocessors.
   699   - Optimized "Multiset.multiset" and "FinFun.finfun".
   700   - Improved efficiency of "destroy_constrs" optimization.
   701   - Fixed soundness bugs related to "destroy_constrs" optimization and
   702     record getters.
   703   - Fixed soundness bug related to higher-order constructors.
   704   - Fixed soundness bug when "full_descrs" is enabled.
   705   - Improved precision of set constructs.
   706   - Added "atoms" option.
   707   - Added cache to speed up repeated Kodkod invocations on the same
   708     problems.
   709   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   710     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   711     "SAT4J_Light".  INCOMPATIBILITY.
   712   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   713     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   714   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   715 
   716 * Method "induct" now takes instantiations of the form t, where t is not
   717   a variable, as a shorthand for "x == t", where x is a fresh variable.
   718   If this is not intended, t has to be enclosed in parentheses.
   719   By default, the equalities generated by definitional instantiations
   720   are pre-simplified, which may cause parameters of inductive cases
   721   to disappear, or may even delete some of the inductive cases.
   722   Use "induct (no_simp)" instead of "induct" to restore the old
   723   behaviour. The (no_simp) option is also understood by the "cases"
   724   and "nominal_induct" methods, which now perform pre-simplification, too.
   725   INCOMPATIBILITY.
   726 
   727 
   728 *** HOLCF ***
   729 
   730 * Variable names in lemmas generated by the domain package have
   731 changed; the naming scheme is now consistent with the HOL datatype
   732 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   733 
   734 * The domain package no longer defines the function "foo_copy" for
   735 recursive domain "foo".  The reach lemma is now stated directly in
   736 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   737 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   738 
   739 * Most definedness lemmas generated by the domain package (previously
   740 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   741 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   742 Proofs that used definedness lemmas as intro rules may break,
   743 potential INCOMPATIBILITY.
   744 
   745 * Induction and casedist rules generated by the domain package now
   746 declare proper case_names (one called "bottom", and one named for each
   747 constructor).  INCOMPATIBILITY.
   748 
   749 * For mutually-recursive domains, separate "reach" and "take_lemma"
   750 rules are generated for each domain, INCOMPATIBILITY.
   751 
   752   foo_bar.reach       ~> foo.reach  bar.reach
   753   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   754 
   755 * Some lemmas generated by the domain package have been renamed for
   756 consistency with the datatype package, INCOMPATIBILITY.
   757 
   758   foo.ind        ~> foo.induct
   759   foo.finite_ind ~> foo.finite_induct
   760   foo.coind      ~> foo.coinduct
   761   foo.casedist   ~> foo.exhaust
   762   foo.exhaust    ~> foo.nchotomy
   763 
   764 * For consistency with other definition packages, the fixrec package
   765 now generates qualified theorem names, INCOMPATIBILITY.
   766 
   767   foo_simps  ~> foo.simps
   768   foo_unfold ~> foo.unfold
   769   foo_induct ~> foo.induct
   770 
   771 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   772 method and internal fixrec proofs now use the default simpset instead.
   773 INCOMPATIBILITY.
   774 
   775 * The "contlub" predicate has been removed.  Proof scripts should use
   776 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   777 
   778 * The "admw" predicate has been removed, INCOMPATIBILITY.
   779 
   780 * The constants cpair, cfst, and csnd have been removed in favor of
   781 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   782 
   783 
   784 *** ML ***
   785 
   786 * Antiquotations for basic formal entities:
   787 
   788     @{class NAME}         -- type class
   789     @{class_syntax NAME}  -- syntax representation of the above
   790 
   791     @{type_name NAME}     -- logical type
   792     @{type_abbrev NAME}   -- type abbreviation
   793     @{nonterminal NAME}   -- type of concrete syntactic category
   794     @{type_syntax NAME}   -- syntax representation of any of the above
   795 
   796     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   797     @{const_abbrev NAME}  -- abbreviated constant
   798     @{const_syntax NAME}  -- syntax representation of any of the above
   799 
   800 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   801 syntax constant (cf. 'syntax' command).
   802 
   803 * Antiquotation @{make_string} inlines a function to print arbitrary
   804 values similar to the ML toplevel.  The result is compiler dependent
   805 and may fall back on "?" in certain situations.
   806 
   807 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   808 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   809 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   810 not work with the asynchronous Isar document model.
   811 
   812 * Configuration options now admit dynamic default values, depending on
   813 the context or even global references.
   814 
   815 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   816 uses an efficient external library if available (for Poly/ML).
   817 
   818 * Renamed some important ML structures, while keeping the old names
   819 for some time as aliases within the structure Legacy:
   820 
   821   OuterKeyword  ~>  Keyword
   822   OuterLex      ~>  Token
   823   OuterParse    ~>  Parse
   824   OuterSyntax   ~>  Outer_Syntax
   825   PrintMode     ~>  Print_Mode
   826   SpecParse     ~>  Parse_Spec
   827   ThyInfo       ~>  Thy_Info
   828   ThyLoad       ~>  Thy_Load
   829   ThyOutput     ~>  Thy_Output
   830   TypeInfer     ~>  Type_Infer
   831 
   832 Note that "open Legacy" simplifies porting of sources, but forgetting
   833 to remove it again will complicate porting again in the future.
   834 
   835 * Most operations that refer to a global context are named
   836 accordingly, e.g. Simplifier.global_context or
   837 ProofContext.init_global.  There are some situations where a global
   838 context actually works, but under normal circumstances one needs to
   839 pass the proper local context through the code!
   840 
   841 * Discontinued old TheoryDataFun with its copy/init operation -- data
   842 needs to be pure.  Functor Theory_Data_PP retains the traditional
   843 Pretty.pp argument to merge, which is absent in the standard
   844 Theory_Data version.
   845 
   846 * Sorts.certify_sort and derived "cert" operations for types and terms
   847 no longer minimize sorts.  Thus certification at the boundary of the
   848 inference kernel becomes invariant under addition of class relations,
   849 which is an important monotonicity principle.  Sorts are now minimized
   850 in the syntax layer only, at the boundary between the end-user and the
   851 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   852 explicitly in rare situations.
   853 
   854 * Renamed old-style Drule.standard to Drule.export_without_context, to
   855 emphasize that this is in no way a standard operation.
   856 INCOMPATIBILITY.
   857 
   858 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   859 usual for resolution.  Rare INCOMPATIBILITY.
   860 
   861 * Renamed varify/unvarify operations to varify_global/unvarify_global
   862 to emphasize that these only work in a global situation (which is
   863 quite rare).
   864 
   865 * Curried take and drop in library.ML; negative length is interpreted
   866 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   867 
   868 * Proof terms: type substitutions on proof constants now use canonical
   869 order of type variables.  INCOMPATIBILITY for tools working with proof
   870 terms.
   871 
   872 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   873 may no longer carry premises.  User-level specifications are
   874 transformed accordingly by Thm.add_axiom/add_def.
   875 
   876 
   877 *** System ***
   878 
   879 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   880 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   881 proof terms are enabled unconditionally in the new HOL-Proofs image.
   882 
   883 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   884 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   885 respectively.
   886 
   887 * Old lib/scripts/polyml-platform is superseded by the
   888 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   889 variant, even on a 64 bit machine.  The following example setting
   890 prefers 64 bit if available:
   891 
   892   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   893 
   894 * The preliminary Isabelle/jEdit application demonstrates the emerging
   895 Isabelle/Scala layer for advanced prover interaction and integration.
   896 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   897 component.
   898 
   899 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   900 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   901 similar to the default assignment of the document preparation system
   902 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   903 provides some operations for direct access to the font without asking
   904 the user for manual installation.
   905 
   906 
   907 
   908 New in Isabelle2009-1 (December 2009)
   909 -------------------------------------
   910 
   911 *** General ***
   912 
   913 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   914 one backslash should be used, even in ML sources.
   915 
   916 
   917 *** Pure ***
   918 
   919 * Locale interpretation propagates mixins along the locale hierarchy.
   920 The currently only available mixins are the equations used to map
   921 local definitions to terms of the target domain of an interpretation.
   922 
   923 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   924 loc" to print all interpretations of locale "loc" in the theory.
   925 Interpretations in proofs are not shown.
   926 
   927 * Thoroughly revised locales tutorial.  New section on conditional
   928 interpretation.
   929 
   930 * On instantiation of classes, remaining undefined class parameters
   931 are formally declared.  INCOMPATIBILITY.
   932 
   933 
   934 *** Document preparation ***
   935 
   936 * New generalized style concept for printing terms: @{foo (style) ...}
   937 instead of @{foo_style style ...}  (old form is still retained for
   938 backward compatibility).  Styles can be also applied for
   939 antiquotations prop, term_type and typeof.
   940 
   941 
   942 *** HOL ***
   943 
   944 * New proof method "smt" for a combination of first-order logic with
   945 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   946 fixed-size bitvectors; there is also basic support for higher-order
   947 features (esp. lambda abstractions).  It is an incomplete decision
   948 procedure based on external SMT solvers using the oracle mechanism;
   949 for the SMT solver Z3, this method is proof-producing.  Certificates
   950 are provided to avoid calling the external solvers solely for
   951 re-checking proofs.  Due to a remote SMT service there is no need for
   952 installing SMT solvers locally.  See src/HOL/SMT.
   953 
   954 * New commands to load and prove verification conditions generated by
   955 the Boogie program verifier or derived systems (e.g. the Verifying C
   956 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   957 
   958 * New counterexample generator tool 'nitpick' based on the Kodkod
   959 relational model finder.  See src/HOL/Tools/Nitpick and
   960 src/HOL/Nitpick_Examples.
   961 
   962 * New commands 'code_pred' and 'values' to invoke the predicate
   963 compiler and to enumerate values of inductive predicates.
   964 
   965 * A tabled implementation of the reflexive transitive closure.
   966 
   967 * New implementation of quickcheck uses generic code generator;
   968 default generators are provided for all suitable HOL types, records
   969 and datatypes.  Old quickcheck can be re-activated importing theory
   970 Library/SML_Quickcheck.
   971 
   972 * New testing tool Mirabelle for automated proof tools.  Applies
   973 several tools and tactics like sledgehammer, metis, or quickcheck, to
   974 every proof step in a theory.  To be used in batch mode via the
   975 "mirabelle" utility.
   976 
   977 * New proof method "sos" (sum of squares) for nonlinear real
   978 arithmetic (originally due to John Harison). It requires theory
   979 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   980 works well in practice on quantifier-free real arithmetic with +, -,
   981 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   982 inequalities between polynomials.  It makes use of external
   983 semidefinite programming solvers.  Method "sos" generates a
   984 certificate that can be pasted into the proof thus avoiding the need
   985 to call an external tool every time the proof is checked.  See
   986 src/HOL/Library/Sum_Of_Squares.
   987 
   988 * New method "linarith" invokes existing linear arithmetic decision
   989 procedure only.
   990 
   991 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   992 
   993 * New Sledgehammer option "Full Types" in Proof General settings menu.
   994 Causes full type information to be output to the ATPs.  This slows
   995 ATPs down considerably but eliminates a source of unsound "proofs"
   996 that fail later.
   997 
   998 * New method "metisFT": A version of metis that uses full type
   999 information in order to avoid failures of proof reconstruction.
  1000 
  1001 * New evaluator "approximate" approximates an real valued term using
  1002 the same method as the approximation method.
  1003 
  1004 * Method "approximate" now supports arithmetic expressions as
  1005 boundaries of intervals and implements interval splitting and Taylor
  1006 series expansion.
  1007 
  1008 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1009 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1010 
  1011 * New theory SupInf of the supremum and infimum operators for sets of
  1012 reals.
  1013 
  1014 * New theory Probability, which contains a development of measure
  1015 theory, eventually leading to Lebesgue integration and probability.
  1016 
  1017 * Extended Multivariate Analysis to include derivation and Brouwer's
  1018 fixpoint theorem.
  1019 
  1020 * Reorganization of number theory, INCOMPATIBILITY:
  1021   - new number theory development for nat and int, in theories Divides
  1022     and GCD as well as in new session Number_Theory
  1023   - some constants and facts now suffixed with _nat and _int
  1024     accordingly
  1025   - former session NumberTheory now named Old_Number_Theory, including
  1026     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1027   - moved theory Pocklington from src/HOL/Library to
  1028     src/HOL/Old_Number_Theory
  1029 
  1030 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1031 lcm of finite and infinite sets. It is shown that they form a complete
  1032 lattice.
  1033 
  1034 * Class semiring_div requires superclass no_zero_divisors and proof of
  1035 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1036 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1037 generalized to class semiring_div, subsuming former theorems
  1038 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1039 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1040 INCOMPATIBILITY.
  1041 
  1042 * Refinements to lattice classes and sets:
  1043   - less default intro/elim rules in locale variant, more default
  1044     intro/elim rules in class variant: more uniformity
  1045   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1046     le_inf_iff
  1047   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1048     sup_aci)
  1049   - renamed ACI to inf_sup_aci
  1050   - new class "boolean_algebra"
  1051   - class "complete_lattice" moved to separate theory
  1052     "Complete_Lattice"; corresponding constants (and abbreviations)
  1053     renamed and with authentic syntax:
  1054     Set.Inf ~>    Complete_Lattice.Inf
  1055     Set.Sup ~>    Complete_Lattice.Sup
  1056     Set.INFI ~>   Complete_Lattice.INFI
  1057     Set.SUPR ~>   Complete_Lattice.SUPR
  1058     Set.Inter ~>  Complete_Lattice.Inter
  1059     Set.Union ~>  Complete_Lattice.Union
  1060     Set.INTER ~>  Complete_Lattice.INTER
  1061     Set.UNION ~>  Complete_Lattice.UNION
  1062   - authentic syntax for
  1063     Set.Pow
  1064     Set.image
  1065   - mere abbreviations:
  1066     Set.empty               (for bot)
  1067     Set.UNIV                (for top)
  1068     Set.inter               (for inf, formerly Set.Int)
  1069     Set.union               (for sup, formerly Set.Un)
  1070     Complete_Lattice.Inter  (for Inf)
  1071     Complete_Lattice.Union  (for Sup)
  1072     Complete_Lattice.INTER  (for INFI)
  1073     Complete_Lattice.UNION  (for SUPR)
  1074   - object-logic definitions as far as appropriate
  1075 
  1076 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1077 Un_subset_iff are explicitly deleted as default simp rules; then also
  1078 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1079 deleted to achieve the desired effect.
  1080 
  1081 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1082 rules by default any longer; the same applies to min_max.inf_absorb1
  1083 etc.  INCOMPATIBILITY.
  1084 
  1085 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1086 pred_set_conv by default.  INCOMPATIBILITY.
  1087 
  1088 * Power operations on relations and functions are now one dedicated
  1089 constant "compow" with infix syntax "^^".  Power operation on
  1090 multiplicative monoids retains syntax "^" and is now defined generic
  1091 in class power.  INCOMPATIBILITY.
  1092 
  1093 * Relation composition "R O S" now has a more standard argument order:
  1094 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1095 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1096 break, since the O_assoc rule was not rewritten like this.  Fix using
  1097 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1098 
  1099 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1100 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1101 INCOMPATIBILITY.
  1102 
  1103 * Most rules produced by inductive and datatype package have mandatory
  1104 prefixes.  INCOMPATIBILITY.
  1105 
  1106 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1107 the attribute of the same name.  Each of the theorems in the list
  1108 DERIV_intros assumes composition with an additional function and
  1109 matches a variable to the derivative, which has to be solved by the
  1110 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1111 of most elementary terms.  Former Maclauren.DERIV_tac and
  1112 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1113 INCOMPATIBILITY.
  1114 
  1115 * Code generator attributes follow the usual underscore convention:
  1116     code_unfold     replaces    code unfold
  1117     code_post       replaces    code post
  1118     etc.
  1119   INCOMPATIBILITY.
  1120 
  1121 * Renamed methods:
  1122     sizechange -> size_change
  1123     induct_scheme -> induction_schema
  1124   INCOMPATIBILITY.
  1125 
  1126 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1127 INCOMPATIBILITY, use "undefined" directly.
  1128 
  1129 * Renamed theorems:
  1130     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1131     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1132     Suc_plus1 -> Suc_eq_plus1
  1133     *anti_sym -> *antisym*
  1134     vector_less_eq_def -> vector_le_def
  1135   INCOMPATIBILITY.
  1136 
  1137 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1138 INCOMPATIBILITY.
  1139 
  1140 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1141 INCOMPATIBILITY.
  1142 
  1143 
  1144 *** HOLCF ***
  1145 
  1146 * Theory Representable defines a class "rep" of domains that are
  1147 representable (via an ep-pair) in the universal domain type "udom".
  1148 Instances are provided for all type constructors defined in HOLCF.
  1149 
  1150 * The 'new_domain' command is a purely definitional version of the
  1151 domain package, for representable domains.  Syntax is identical to the
  1152 old domain package.  The 'new_domain' package also supports indirect
  1153 recursion using previously-defined type constructors.  See
  1154 src/HOLCF/ex/New_Domain.thy for examples.
  1155 
  1156 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1157 on the left-hand side of an equation, and then performs
  1158 simplification.  Rewriting is done using rules declared with the
  1159 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1160 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1161 
  1162 * The pattern-match compiler in 'fixrec' can now handle constructors
  1163 with HOL function types.  Pattern-match combinators for the Pair
  1164 constructor are pre-configured.
  1165 
  1166 * The 'fixrec' package now produces better fixed-point induction rules
  1167 for mutually-recursive definitions:  Induction rules have conclusions
  1168 of the form "P foo bar" instead of "P <foo, bar>".
  1169 
  1170 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1171 been renamed to "below".  The name "below" now replaces "less" in many
  1172 theorem names.  (Legacy theorem names using "less" are still supported
  1173 as well.)
  1174 
  1175 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1176 patterns can be used to generate strictness rules, or to make
  1177 functions more strict (much like the bang-patterns supported by the
  1178 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1179 examples.
  1180 
  1181 
  1182 *** ML ***
  1183 
  1184 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1185 errors and run-time exceptions, including detailed source positions.
  1186 
  1187 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1188 identified entries, with some additional information such as source
  1189 position, logical grouping etc.
  1190 
  1191 * Theory and context data is now introduced by the simplified and
  1192 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1193 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1194 copy operation) is still available for some time.
  1195 
  1196 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1197 provides a high-level programming interface to synchronized state
  1198 variables with atomic update.  This works via pure function
  1199 application within a critical section -- its runtime should be as
  1200 short as possible; beware of deadlocks if critical code is nested,
  1201 either directly or indirectly via other synchronized variables!
  1202 
  1203 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1204 wraps raw ML references, explicitly indicating their non-thread-safe
  1205 behaviour.  The Isar toplevel keeps this structure open, to
  1206 accommodate Proof General as well as quick and dirty interactive
  1207 experiments with references.
  1208 
  1209 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1210 parallel tactical reasoning.
  1211 
  1212 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1213 are similar to SUBPROOF, but are slightly more flexible: only the
  1214 specified parts of the subgoal are imported into the context, and the
  1215 body tactic may introduce new subgoals and schematic variables.
  1216 
  1217 * Old tactical METAHYPS, which does not observe the proof context, has
  1218 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1219 or Subgoal.FOCUS etc.
  1220 
  1221 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1222 functors have their own ML name space there is no point to mark them
  1223 separately.)  Minor INCOMPATIBILITY.
  1224 
  1225 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1226 
  1227 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1228 INCOMPATIBILITY.
  1229 
  1230 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1231 mode, which avoids critical setmp.
  1232 
  1233 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1234 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1235 Attrib/Method.setup introduced in Isabelle2009.
  1236 
  1237 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1238 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1239 last resort.  INCOMPATIBILITY.
  1240 
  1241 * Display.pretty_thm now requires a proper context (cf. former
  1242 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1243 or even Display.pretty_thm_without_context as last resort.
  1244 INCOMPATIBILITY.
  1245 
  1246 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1247 Syntax.pretty_typ/term directly, preferably with proper context
  1248 instead of global theory.
  1249 
  1250 
  1251 *** System ***
  1252 
  1253 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1254 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1255 usedir option -q.
  1256 
  1257 * Support for additional "Isabelle components" via etc/components, see
  1258 also the system manual.
  1259 
  1260 * The isabelle makeall tool now operates on all components with
  1261 IsaMakefile, not just hardwired "logics".
  1262 
  1263 * Removed "compress" option from isabelle-process and isabelle usedir;
  1264 this is always enabled.
  1265 
  1266 * Discontinued support for Poly/ML 4.x versions.
  1267 
  1268 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1269 on a given logic image.  This requires the lighttpd webserver and is
  1270 currently supported on Linux only.
  1271 
  1272 
  1273 
  1274 New in Isabelle2009 (April 2009)
  1275 --------------------------------
  1276 
  1277 *** General ***
  1278 
  1279 * Simplified main Isabelle executables, with less surprises on
  1280 case-insensitive file-systems (such as Mac OS).
  1281 
  1282   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1283     "isatool."
  1284 
  1285   - The former "isabelle" alias for "isabelle-process" has been
  1286     removed (should rarely occur to regular users).
  1287 
  1288   - The former "isabelle-interface" and its alias "Isabelle" have been
  1289     removed (interfaces are now regular Isabelle tools).
  1290 
  1291 Within scripts and make files, the Isabelle environment variables
  1292 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1293 respectively.  (The latter are still available as legacy feature.)
  1294 
  1295 The old isabelle-interface wrapper could react in confusing ways if
  1296 the interface was uninstalled or changed otherwise.  Individual
  1297 interface tool configuration is now more explicit, see also the
  1298 Isabelle system manual.  In particular, Proof General is now available
  1299 via "isabelle emacs".
  1300 
  1301 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1302 purge installed copies of Isabelle executables and re-run "isabelle
  1303 install -p ...", or use symlinks.
  1304 
  1305 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1306 old ~/isabelle, which was slightly non-standard and apt to cause
  1307 surprises on case-insensitive file-systems (such as Mac OS).
  1308 
  1309 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1310 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1311 care is required when using older releases of Isabelle.  Note that
  1312 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1313 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1314 
  1315 * Proofs of fully specified statements are run in parallel on
  1316 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1317 a regular 4-core machine, if the initial heap space is made reasonably
  1318 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1319 
  1320 * The main reference manuals ("isar-ref", "implementation", and
  1321 "system") have been updated and extended.  Formally checked references
  1322 as hyperlinks are now available uniformly.
  1323 
  1324 
  1325 *** Pure ***
  1326 
  1327 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1328 respects.  The most important changes are listed below.  See the
  1329 Tutorial on Locales ("locales" manual) for details.
  1330 
  1331 - In locale expressions, instantiation replaces renaming.  Parameters
  1332 must be declared in a for clause.  To aid compatibility with previous
  1333 parameter inheritance, in locale declarations, parameters that are not
  1334 'touched' (instantiation position "_" or omitted) are implicitly added
  1335 with their syntax at the beginning of the for clause.
  1336 
  1337 - Syntax from abbreviations and definitions in locales is available in
  1338 locale expressions and context elements.  The latter is particularly
  1339 useful in locale declarations.
  1340 
  1341 - More flexible mechanisms to qualify names generated by locale
  1342 expressions.  Qualifiers (prefixes) may be specified in locale
  1343 expressions, and can be marked as mandatory (syntax: "name!:") or
  1344 optional (syntax "name?:").  The default depends for plain "name:"
  1345 depends on the situation where a locale expression is used: in
  1346 commands 'locale' and 'sublocale' prefixes are optional, in
  1347 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1348 implicit qualifiers derived from the parameter names of a locale are
  1349 no longer generated.
  1350 
  1351 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1352 instantiation clause in "interpretation" and "interpret" (square
  1353 brackets) is no longer available.  Use locale expressions.
  1354 
  1355 - When converting proof scripts, mandatory qualifiers in
  1356 'interpretation' and 'interpret' should be retained by default, even
  1357 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1358 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1359 in locale expressions range over a single locale instance only.
  1360 
  1361 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1362 In existing theorem specifications replace the includes element by the
  1363 respective context elements of the included locale, omitting those
  1364 that are already present in the theorem specification.  Multiple
  1365 assume elements of a locale should be replaced by a single one
  1366 involving the locale predicate.  In the proof body, declarations (most
  1367 notably theorems) may be regained by interpreting the respective
  1368 locales in the proof context as required (command "interpret").
  1369 
  1370 If using "includes" in replacement of a target solely because the
  1371 parameter types in the theorem are not as general as in the target,
  1372 consider declaring a new locale with additional type constraints on
  1373 the parameters (context element "constrains").
  1374 
  1375 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1376 
  1377 - Locale interpretation commands no longer attempt to simplify goal.
  1378 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1379 methods intro_locales and unfold_locales to clarify.
  1380 
  1381 - Locale interpretation commands no longer accept interpretation
  1382 attributes.  INCOMPATIBILITY.
  1383 
  1384 * Class declaration: so-called "base sort" must not be given in import
  1385 list any longer, but is inferred from the specification.  Particularly
  1386 in HOL, write
  1387 
  1388     class foo = ...
  1389 
  1390 instead of
  1391 
  1392     class foo = type + ...
  1393 
  1394 * Class target: global versions of theorems stemming do not carry a
  1395 parameter prefix any longer.  INCOMPATIBILITY.
  1396 
  1397 * Class 'instance' command no longer accepts attached definitions.
  1398 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1399 
  1400 * Recovered hiding of consts, which was accidentally broken in
  1401 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1402 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1403 
  1404 * Slightly more coherent Pure syntax, with updated documentation in
  1405 isar-ref manual.  Removed locales meta_term_syntax and
  1406 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1407 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1408 directly in regular applications.
  1409 
  1410 * There is a new syntactic category "float_const" for signed decimal
  1411 fractions (e.g. 123.45 or -123.45).
  1412 
  1413 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1414 interface with 'setup' command instead.
  1415 
  1416 * Command 'local_setup' is similar to 'setup', but operates on a local
  1417 theory context.
  1418 
  1419 * The 'axiomatization' command now only works within a global theory
  1420 context.  INCOMPATIBILITY.
  1421 
  1422 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1423 hypotheses.  Sorts required in the course of reasoning need to be
  1424 covered by the constraints in the initial statement, completed by the
  1425 type instance information of the background theory.  Non-trivial sort
  1426 hypotheses, which rarely occur in practice, may be specified via
  1427 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1428 
  1429   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1430 
  1431 The result contains an implicit sort hypotheses as before --
  1432 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1433 normalization.
  1434 
  1435 * Generalized Isar history, with support for linear undo, direct state
  1436 addressing etc.
  1437 
  1438 * Changed defaults for unify configuration options:
  1439 
  1440   unify_trace_bound = 50 (formerly 25)
  1441   unify_search_bound = 60 (formerly 30)
  1442 
  1443 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1444 
  1445   a) On theory merge, the last set of code equations for a particular
  1446      constant is taken (in accordance with the policy applied by other
  1447      parts of the code generator framework).
  1448 
  1449   b) Code equations stemming from explicit declarations (e.g. code
  1450      attribute) gain priority over default code equations stemming
  1451      from definition, primrec, fun etc.
  1452 
  1453 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1454 
  1455 * Unified theorem tables for both code generators.  Thus [code
  1456 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1457 
  1458 * Command 'find_consts' searches for constants based on type and name
  1459 patterns, e.g.
  1460 
  1461     find_consts "_ => bool"
  1462 
  1463 By default, matching is against subtypes, but it may be restricted to
  1464 the whole type.  Searching by name is possible.  Multiple queries are
  1465 conjunctive and queries may be negated by prefixing them with a
  1466 hyphen:
  1467 
  1468     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1469 
  1470 * New 'find_theorems' criterion "solves" matches theorems that
  1471 directly solve the current goal (modulo higher-order unification).
  1472 
  1473 * Auto solve feature for main theorem statements: whenever a new goal
  1474 is stated, "find_theorems solves" is called; any theorems that could
  1475 solve the lemma directly are listed as part of the goal state.
  1476 Cf. associated options in Proof General Isabelle settings menu,
  1477 enabled by default, with reasonable timeout for pathological cases of
  1478 higher-order unification.
  1479 
  1480 
  1481 *** Document preparation ***
  1482 
  1483 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1484 demanding keyword 'by' and supporting the full method expression
  1485 syntax just like the Isar command 'by'.
  1486 
  1487 
  1488 *** HOL ***
  1489 
  1490 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1491 points Main and Complex_Main remain as before.
  1492 
  1493 * Logic image HOL-Plain provides a minimal HOL with the most important
  1494 tools available (inductive, datatype, primrec, ...).  This facilitates
  1495 experimentation and tool development.  Note that user applications
  1496 (and library theories) should never refer to anything below theory
  1497 Main, as before.
  1498 
  1499 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1500 experimentation due to shorter build times.
  1501 
  1502 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1503 were previously part of former HOL-Complex.  Entry point Hyperreal
  1504 remains valid, but theories formerly using Complex_Main should now use
  1505 new entry point Hypercomplex.
  1506 
  1507 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1508 Posix processes.  Avoids potentially expensive forking of the ML
  1509 process.  New thread-based implementation also works on non-Unix
  1510 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1511 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1512 commands are covered in the isar-ref manual.
  1513 
  1514 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1515 sledgehammer without local ATP installation (Vampire etc.). Other
  1516 provers may be included via suitable ML wrappers, see also
  1517 src/HOL/ATP_Linkup.thy.
  1518 
  1519 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1520 menu.
  1521 
  1522 * The metis method no longer fails because the theorem is too trivial
  1523 (contains the empty clause).
  1524 
  1525 * The metis method now fails in the usual manner, rather than raising
  1526 an exception, if it determines that it cannot prove the theorem.
  1527 
  1528 * Method "coherent" implements a prover for coherent logic (see also
  1529 src/Tools/coherent.ML).
  1530 
  1531 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1532 "undefined" is the right choice to replace "arbitrary", though
  1533 logically there is no difference.  INCOMPATIBILITY.
  1534 
  1535 * Command "value" now integrates different evaluation mechanisms.  The
  1536 result of the first successful evaluation mechanism is printed.  In
  1537 square brackets a particular named evaluation mechanisms may be
  1538 specified (currently, [SML], [code] or [nbe]).  See further
  1539 src/HOL/ex/Eval_Examples.thy.
  1540 
  1541 * Normalization by evaluation now allows non-leftlinear equations.
  1542 Declare with attribute [code nbe].
  1543 
  1544 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1545 as the structured Isar versions "cases" and "induct", cf. the
  1546 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1547 are now presented as a list of individual projections
  1548 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1549 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1550 rare situations a different rule is selected --- notably nested tuple
  1551 elimination instead of former prod.exhaust: use explicit (case_tac t
  1552 rule: prod.exhaust) here.
  1553 
  1554 * Attributes "cases", "induct", "coinduct" support "del" option.
  1555 
  1556 * Removed fact "case_split_thm", which duplicates "case_split".
  1557 
  1558 * The option datatype has been moved to a new theory Option.  Renamed
  1559 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1560 
  1561 * New predicate "strict_mono" classifies strict functions on partial
  1562 orders.  With strict functions on linear orders, reasoning about
  1563 (in)equalities is facilitated by theorems "strict_mono_eq",
  1564 "strict_mono_less_eq" and "strict_mono_less".
  1565 
  1566 * Some set operations are now proper qualified constants with
  1567 authentic syntax.  INCOMPATIBILITY:
  1568 
  1569     op Int ~>   Set.Int
  1570     op Un ~>    Set.Un
  1571     INTER ~>    Set.INTER
  1572     UNION ~>    Set.UNION
  1573     Inter ~>    Set.Inter
  1574     Union ~>    Set.Union
  1575     {} ~>       Set.empty
  1576     UNIV ~>     Set.UNIV
  1577 
  1578 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1579 theory Set.
  1580 
  1581 * Auxiliary class "itself" has disappeared -- classes without any
  1582 parameter are treated as expected by the 'class' command.
  1583 
  1584 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1585 
  1586 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1587 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1588 
  1589 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1590 method "approximation".  It proves formulas on real values by using
  1591 interval arithmetic.  In the formulas are also the transcendental
  1592 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1593 allowed. For examples see
  1594 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1595 
  1596 * Theory "Reflection" now resides in HOL/Library.
  1597 
  1598 * Entry point to Word library now simply named "Word".
  1599 INCOMPATIBILITY.
  1600 
  1601 * Made source layout more coherent with logical distribution
  1602 structure:
  1603 
  1604     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1605     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1606     src/HOL/Library/GCD.thy ~> src/HOL/
  1607     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1608     src/HOL/Library/Parity.thy ~> src/HOL/
  1609     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1610     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1611     src/HOL/Real/Lubs.thy ~> src/HOL/
  1612     src/HOL/Real/PReal.thy ~> src/HOL/
  1613     src/HOL/Real/Rational.thy ~> src/HOL/
  1614     src/HOL/Real/RComplete.thy ~> src/HOL/
  1615     src/HOL/Real/RealDef.thy ~> src/HOL/
  1616     src/HOL/Real/RealPow.thy ~> src/HOL/
  1617     src/HOL/Real/Real.thy ~> src/HOL/
  1618     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1619     src/HOL/Complex/Complex.thy ~> src/HOL/
  1620     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1621     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1622     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1623     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1624     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1625     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1626     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1627     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1628     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1629     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1630     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1631     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1632     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1633     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1634     src/HOL/Real/Float ~> src/HOL/Library/
  1635     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1636     src/HOL/Real/RealVector.thy ~> src/HOL/
  1637 
  1638     src/HOL/arith_data.ML ~> src/HOL/Tools
  1639     src/HOL/hologic.ML ~> src/HOL/Tools
  1640     src/HOL/simpdata.ML ~> src/HOL/Tools
  1641     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1642     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1643     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1644     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1645     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1646     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1647     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1648 
  1649     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1650     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1651     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1652     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1653     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1654     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1655 
  1656 * If methods "eval" and "evaluation" encounter a structured proof
  1657 state with !!/==>, only the conclusion is evaluated to True (if
  1658 possible), avoiding strange error messages.
  1659 
  1660 * Method "sizechange" automates termination proofs using (a
  1661 modification of) the size-change principle.  Requires SAT solver.  See
  1662 src/HOL/ex/Termination.thy for examples.
  1663 
  1664 * Simplifier: simproc for let expressions now unfolds if bound
  1665 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1666 
  1667 * Method "arith": Linear arithmetic now ignores all inequalities when
  1668 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1669 
  1670 * New attribute "arith" for facts that should always be used
  1671 automatically by arithmetic. It is intended to be used locally in
  1672 proofs, e.g.
  1673 
  1674   assumes [arith]: "x > 0"
  1675 
  1676 Global usage is discouraged because of possible performance impact.
  1677 
  1678 * New classes "top" and "bot" with corresponding operations "top" and
  1679 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1680 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1681 
  1682 * Changed definition lemma "less_fun_def" in order to provide an
  1683 instance for preorders on functions; use lemma "less_le" instead.
  1684 INCOMPATIBILITY.
  1685 
  1686 * Theory Orderings: class "wellorder" moved here, with explicit
  1687 induction rule "less_induct" as assumption.  For instantiation of
  1688 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1689 INCOMPATIBILITY.
  1690 
  1691 * Theory Orderings: added class "preorder" as superclass of "order".
  1692 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1693 etc. slightly changed.  Some theorems named order_class.* now named
  1694 preorder_class.*.
  1695 
  1696 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1697 "diag" to "Id_on".
  1698 
  1699 * Theory Finite_Set: added a new fold combinator of type
  1700 
  1701   ('a => 'b => 'b) => 'b => 'a set => 'b
  1702 
  1703 Occasionally this is more convenient than the old fold combinator
  1704 which is now defined in terms of the new one and renamed to
  1705 fold_image.
  1706 
  1707 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1708 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1709 extended with further lemmas!).  At the moment both still exist but
  1710 the former will disappear at some point.
  1711 
  1712 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1713 class recpower.  Type-specific simp rules for various recpower types
  1714 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1715 
  1716 rat_power_0    -> power_0
  1717 rat_power_Suc  -> power_Suc
  1718 realpow_0      -> power_0
  1719 realpow_Suc    -> power_Suc
  1720 complexpow_0   -> power_0
  1721 complexpow_Suc -> power_Suc
  1722 power_poly_0   -> power_0
  1723 power_poly_Suc -> power_Suc
  1724 
  1725 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1726 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1727 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1728 of lemmas from Divides has been generalized from nat to class
  1729 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1730 renames resulting from duplicate elimination:
  1731 
  1732     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1733     zero_dvd_iff ~>         dvd_0_left_iff
  1734     dvd_0 ~>                dvd_0_right
  1735     DIVISION_BY_ZERO_DIV ~> div_by_0
  1736     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1737     mult_div ~>             div_mult_self2_is_id
  1738     mult_mod ~>             mod_mult_self2_is_0
  1739 
  1740 * Theory IntDiv: removed many lemmas that are instances of class-based
  1741 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1742 rename old lemmas as follows:
  1743 
  1744 dvd_diff               -> nat_dvd_diff
  1745 dvd_zminus_iff         -> dvd_minus_iff
  1746 mod_add1_eq            -> mod_add_eq
  1747 mod_mult1_eq           -> mod_mult_right_eq
  1748 mod_mult1_eq'          -> mod_mult_left_eq
  1749 mod_mult_distrib_mod   -> mod_mult_eq
  1750 nat_mod_add_left_eq    -> mod_add_left_eq
  1751 nat_mod_add_right_eq   -> mod_add_right_eq
  1752 nat_mod_div_trivial    -> mod_div_trivial
  1753 nat_mod_mod_trivial    -> mod_mod_trivial
  1754 zdiv_zadd_self1        -> div_add_self1
  1755 zdiv_zadd_self2        -> div_add_self2
  1756 zdiv_zmult_self1       -> div_mult_self2_is_id
  1757 zdiv_zmult_self2       -> div_mult_self1_is_id
  1758 zdvd_triv_left         -> dvd_triv_left
  1759 zdvd_triv_right        -> dvd_triv_right
  1760 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1761 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1762 zmod_zadd_left_eq      -> mod_add_left_eq
  1763 zmod_zadd_right_eq     -> mod_add_right_eq
  1764 zmod_zadd_self1        -> mod_add_self1
  1765 zmod_zadd_self2        -> mod_add_self2
  1766 zmod_zadd1_eq          -> mod_add_eq
  1767 zmod_zdiff1_eq         -> mod_diff_eq
  1768 zmod_zdvd_zmod         -> mod_mod_cancel
  1769 zmod_zmod_cancel       -> mod_mod_cancel
  1770 zmod_zmult_self1       -> mod_mult_self2_is_0
  1771 zmod_zmult_self2       -> mod_mult_self1_is_0
  1772 zmod_1                 -> mod_by_1
  1773 zdiv_1                 -> div_by_1
  1774 zdvd_abs1              -> abs_dvd_iff
  1775 zdvd_abs2              -> dvd_abs_iff
  1776 zdvd_refl              -> dvd_refl
  1777 zdvd_trans             -> dvd_trans
  1778 zdvd_zadd              -> dvd_add
  1779 zdvd_zdiff             -> dvd_diff
  1780 zdvd_zminus_iff        -> dvd_minus_iff
  1781 zdvd_zminus2_iff       -> minus_dvd_iff
  1782 zdvd_zmultD            -> dvd_mult_right
  1783 zdvd_zmultD2           -> dvd_mult_left
  1784 zdvd_zmult_mono        -> mult_dvd_mono
  1785 zdvd_0_right           -> dvd_0_right
  1786 zdvd_0_left            -> dvd_0_left_iff
  1787 zdvd_1_left            -> one_dvd
  1788 zminus_dvd_iff         -> minus_dvd_iff
  1789 
  1790 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1791 
  1792 * The real numbers offer decimal input syntax: 12.34 is translated
  1793 into 1234/10^2. This translation is not reversed upon output.
  1794 
  1795 * Theory Library/Polynomial defines an abstract type 'a poly of
  1796 univariate polynomials with coefficients of type 'a.  In addition to
  1797 the standard ring operations, it also supports div and mod.  Code
  1798 generation is also supported, using list-style constructors.
  1799 
  1800 * Theory Library/Inner_Product defines a class of real_inner for real
  1801 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1802 => real.  Class real_inner is a subclass of real_normed_vector from
  1803 theory RealVector.
  1804 
  1805 * Theory Library/Product_Vector provides instances for the product
  1806 type 'a * 'b of several classes from RealVector and Inner_Product.
  1807 Definitions of addition, subtraction, scalar multiplication, norms,
  1808 and inner products are included.
  1809 
  1810 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1811 addition to the field operations, numerals and case syntax are also
  1812 supported.
  1813 
  1814 * Theory Library/Diagonalize provides constructive version of Cantor's
  1815 first diagonalization argument.
  1816 
  1817 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1818 zlcm (for int); carried together from various gcd/lcm developements in
  1819 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1820 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1821 may recover tupled syntax as follows:
  1822 
  1823     hide (open) const gcd
  1824     abbreviation gcd where
  1825       "gcd == (%(a, b). GCD.gcd a b)"
  1826     notation (output)
  1827       GCD.gcd ("gcd '(_, _')")
  1828 
  1829 The same works for lcm, zgcd, zlcm.
  1830 
  1831 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1832 instantiations for algebraic structures.  Removed some duplicate
  1833 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1834 
  1835 * ML antiquotation @{code} takes a constant as argument and generates
  1836 corresponding code in background and inserts name of the corresponding
  1837 resulting ML value/function/datatype constructor binding in place.
  1838 All occurrences of @{code} with a single ML block are generated
  1839 simultaneously.  Provides a generic and safe interface for
  1840 instrumentalizing code generation.  See
  1841 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1842 In future you ought to refrain from ad-hoc compiling generated SML
  1843 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1844 cannot refer to constants for which user-defined serializations are
  1845 set.  Refer to the corresponding ML counterpart directly in that
  1846 cases.
  1847 
  1848 * Command 'rep_datatype': instead of theorem names the command now
  1849 takes a list of terms denoting the constructors of the type to be
  1850 represented as datatype.  The characteristic theorems have to be
  1851 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1852 have disappeared in favour of existing ones:
  1853 
  1854     unit_induct                 ~> unit.induct
  1855     prod_induct                 ~> prod.induct
  1856     sum_induct                  ~> sum.induct
  1857     Suc_Suc_eq                  ~> nat.inject
  1858     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1859 
  1860 
  1861 *** HOL-Algebra ***
  1862 
  1863 * New locales for orders and lattices where the equivalence relation
  1864 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1865 locales use a record structure with field eq for the equivalence.
  1866 
  1867 * New theory of factorial domains.
  1868 
  1869 * Units_l_inv and Units_r_inv are now simp rules by default.
  1870 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1871 and/or r_inv will now also require deletion of these lemmas.
  1872 
  1873 * Renamed the following theorems, INCOMPATIBILITY:
  1874 
  1875 UpperD ~> Upper_memD
  1876 LowerD ~> Lower_memD
  1877 least_carrier ~> least_closed
  1878 greatest_carrier ~> greatest_closed
  1879 greatest_Lower_above ~> greatest_Lower_below
  1880 one_zero ~> carrier_one_zero
  1881 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1882 
  1883 
  1884 *** HOL-Nominal ***
  1885 
  1886 * Nominal datatypes can now contain type-variables.
  1887 
  1888 * Commands 'nominal_inductive' and 'equivariance' work with local
  1889 theory targets.
  1890 
  1891 * Nominal primrec can now works with local theory targets and its
  1892 specification syntax now conforms to the general format as seen in
  1893 'inductive' etc.
  1894 
  1895 * Method "perm_simp" honours the standard simplifier attributes
  1896 (no_asm), (no_asm_use) etc.
  1897 
  1898 * The new predicate #* is defined like freshness, except that on the
  1899 left hand side can be a set or list of atoms.
  1900 
  1901 * Experimental command 'nominal_inductive2' derives strong induction
  1902 principles for inductive definitions.  In contrast to
  1903 'nominal_inductive', which can only deal with a fixed number of
  1904 binders, it can deal with arbitrary expressions standing for sets of
  1905 atoms to be avoided.  The only inductive definition we have at the
  1906 moment that needs this generalisation is the typing rule for Lets in
  1907 the algorithm W:
  1908 
  1909  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1910  -----------------------------------------------------------------
  1911          Gamma |- Let x be t1 in t2 : T2
  1912 
  1913 In this rule one wants to avoid all the binders that are introduced by
  1914 "close Gamma T1".  We are looking for other examples where this
  1915 feature might be useful.  Please let us know.
  1916 
  1917 
  1918 *** HOLCF ***
  1919 
  1920 * Reimplemented the simplification procedure for proving continuity
  1921 subgoals.  The new simproc is extensible; users can declare additional
  1922 continuity introduction rules with the attribute [cont2cont].
  1923 
  1924 * The continuity simproc now uses a different introduction rule for
  1925 solving continuity subgoals on terms with lambda abstractions.  In
  1926 some rare cases the new simproc may fail to solve subgoals that the
  1927 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1928 Potential INCOMPATIBILITY.
  1929 
  1930 * Command 'fixrec': specification syntax now conforms to the general
  1931 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1932 examples.  INCOMPATIBILITY.
  1933 
  1934 
  1935 *** ZF ***
  1936 
  1937 * Proof of Zorn's Lemma for partial orders.
  1938 
  1939 
  1940 *** ML ***
  1941 
  1942 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1943 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1944 depends on multithreading, so timouts will not work before Poly/ML
  1945 5.2.1!
  1946 
  1947 * High-level support for concurrent ML programming, see
  1948 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1949 particularly convenient to organize independent functional
  1950 computations.  The concept of "synchronized variables" provides a
  1951 higher-order interface for components with shared state, avoiding the
  1952 delicate details of mutexes and condition variables.  (Requires
  1953 Poly/ML 5.2.1 or later.)
  1954 
  1955 * ML bindings produced via Isar commands are stored within the Isar
  1956 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1957 become thread-safe and work with undo as expected (concerning
  1958 top-level bindings, not side-effects on global references).
  1959 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1960 compiler at runtime; really global bindings need to be given outside a
  1961 theory.  (Requires Poly/ML 5.2 or later.)
  1962 
  1963 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1964 context.  Top-level ML bindings are stored within the proof context in
  1965 a purely sequential fashion, disregarding the nested proof structure.
  1966 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1967 proof.  (Requires Poly/ML 5.2 or later.)
  1968 
  1969 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1970 and Method.setup, as well as Isar commands 'attribute_setup' and
  1971 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1972 existing code accordingly, or use plain 'setup' together with old
  1973 Method.add_method.
  1974 
  1975 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1976 to 'a -> thm, while results are always tagged with an authentic oracle
  1977 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1978 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1979 accordingly.  Note that extra performance may be gained by producing
  1980 the cterm carefully, avoiding slow Thm.cterm_of.
  1981 
  1982 * Simplified interface for defining document antiquotations via
  1983 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1984 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1985 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1986 examples.
  1987 
  1988 * More systematic treatment of long names, abstract name bindings, and
  1989 name space operations.  Basic operations on qualified names have been
  1990 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1991 Long_Name.append.  Old type bstring has been mostly replaced by
  1992 abstract type binding (see structure Binding), which supports precise
  1993 qualification by packages and local theory targets, as well as proper
  1994 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1995 bstring values into Binding.name, or better pass through abstract
  1996 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1997 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1998 
  1999 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2000 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2001 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2002 
  2003 * Disposed old type and term read functions (Sign.read_def_typ,
  2004 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2005 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2006 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2007 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2008 resort for legacy applications.
  2009 
  2010 * Disposed old declarations, tactics, tactic combinators that refer to
  2011 the simpset or claset of an implicit theory (such as Addsimps,
  2012 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2013 embedded ML text, or local_simpset_of with a proper context passed as
  2014 explicit runtime argument.
  2015 
  2016 * Rules and tactics that read instantiations (read_instantiate,
  2017 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2018 context, which is required for parsing and type-checking.  Moreover,
  2019 the variables are specified as plain indexnames, not string encodings
  2020 thereof.  INCOMPATIBILITY.
  2021 
  2022 * Generic Toplevel.add_hook interface allows to analyze the result of
  2023 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2024 for theorem dependency output of transactions resulting in a new
  2025 theory state.
  2026 
  2027 * ML antiquotations: block-structured compilation context indicated by
  2028 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2029 
  2030   @{binding name}                         - basic name binding
  2031   @{let ?pat = term}                      - term abbreviation (HO matching)
  2032   @{note name = fact}                     - fact abbreviation
  2033   @{thm fact}                             - singleton fact (with attributes)
  2034   @{thms fact}                            - general fact (with attributes)
  2035   @{lemma prop by method}                 - singleton goal
  2036   @{lemma prop by meth1 meth2}            - singleton goal
  2037   @{lemma prop1 ... propN by method}      - general goal
  2038   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2039   @{lemma (open) ...}                     - open derivation
  2040 
  2041 
  2042 *** System ***
  2043 
  2044 * The Isabelle "emacs" tool provides a specific interface to invoke
  2045 Proof General / Emacs, with more explicit failure if that is not
  2046 installed (the old isabelle-interface script silently falls back on
  2047 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2048 installation location of the Proof General distribution.
  2049 
  2050 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2051 the Isabelle process into a JVM/Scala application.  See
  2052 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2053 process wrapper has been discontinued.)
  2054 
  2055 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2056 
  2057 * Various status messages (with exact source position information) are
  2058 emitted, if proper markup print mode is enabled.  This allows
  2059 user-interface components to provide detailed feedback on internal
  2060 prover operations.
  2061 
  2062 
  2063 
  2064 New in Isabelle2008 (June 2008)
  2065 -------------------------------
  2066 
  2067 *** General ***
  2068 
  2069 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2070 and updated, with formally checked references as hyperlinks.
  2071 
  2072 * Theory loader: use_thy (and similar operations) no longer set the
  2073 implicit ML context, which was occasionally hard to predict and in
  2074 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2075 provides a proper context already.
  2076 
  2077 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2078 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2079 'use' within a theory file will do the job.
  2080 
  2081 * Name space merge now observes canonical order, i.e. the second space
  2082 is inserted into the first one, while existing entries in the first
  2083 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2084 swap theory imports.
  2085 
  2086 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2087 INCOMPATIBILITY in identifier syntax etc.
  2088 
  2089 * Outer syntax: string tokens no longer admit escaped white space,
  2090 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2091 white space without escapes.
  2092 
  2093 * Outer syntax: string tokens may contain arbitrary character codes
  2094 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2095 "foo_bar".
  2096 
  2097 
  2098 *** Pure ***
  2099 
  2100 * Context-dependent token translations.  Default setup reverts locally
  2101 fixed variables, and adds hilite markup for undeclared frees.
  2102 
  2103 * Unused theorems can be found using the new command 'unused_thms'.
  2104 There are three ways of invoking it:
  2105 
  2106 (1) unused_thms
  2107      Only finds unused theorems in the current theory.
  2108 
  2109 (2) unused_thms thy_1 ... thy_n -
  2110      Finds unused theorems in the current theory and all of its ancestors,
  2111      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2112 
  2113 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2114      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2115      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2116      their ancestors.
  2117 
  2118 In order to increase the readability of the list produced by
  2119 unused_thms, theorems that have been created by a particular instance
  2120 of a theory command such as 'inductive' or 'function' are considered
  2121 to belong to the same "group", meaning that if at least one theorem in
  2122 this group is used, the other theorems in the same group are no longer
  2123 reported as unused.  Moreover, if all theorems in the group are
  2124 unused, only one theorem in the group is displayed.
  2125 
  2126 Note that proof objects have to be switched on in order for
  2127 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2128 usually the case when using Proof General with the default settings).
  2129 
  2130 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2131 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2132 duplicate fact bindings, or even accidental fact duplications.  Note
  2133 that tools may maintain dynamically scoped facts systematically, using
  2134 PureThy.add_thms_dynamic.
  2135 
  2136 * Command 'hide' now allows to hide from "fact" name space as well.
  2137 
  2138 * Eliminated destructive theorem database, simpset, claset, and
  2139 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2140 update of theories within ML code.
  2141 
  2142 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2143 INCOMPATIBILITY, object-logics depending on former Pure require
  2144 additional setup PureThy.old_appl_syntax_setup; object-logics
  2145 depending on former CPure need to refer to Pure.
  2146 
  2147 * Commands 'use' and 'ML' are now purely functional, operating on
  2148 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2149 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2150 INCOMPATIBILITY.
  2151 
  2152 * Command 'setup': discontinued implicit version with ML reference.
  2153 
  2154 * Instantiation target allows for simultaneous specification of class
  2155 instance operations together with an instantiation proof.
  2156 Type-checking phase allows to refer to class operations uniformly.
  2157 See src/HOL/Complex/Complex.thy for an Isar example and
  2158 src/HOL/Library/Eval.thy for an ML example.
  2159 
  2160 * Indexing of literal facts: be more serious about including only
  2161 facts from the visible specification/proof context, but not the
  2162 background context (locale etc.).  Affects `prop` notation and method
  2163 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2164 situations.
  2165 
  2166 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2167 "(open)" option, which used to expose internal bound variables to the
  2168 proof text.
  2169 
  2170 * Isar statements: removed obsolete case "rule_context".
  2171 INCOMPATIBILITY, better use explicit fixes/assumes.
  2172 
  2173 * Locale proofs: default proof step now includes 'unfold_locales';
  2174 hence 'proof' without argument may be used to unfold locale
  2175 predicates.
  2176 
  2177 
  2178 *** Document preparation ***
  2179 
  2180 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2181 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2182 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2183 spot); renamed link color from "darkblue" to "linkcolor" (default
  2184 value unchanged, can be redefined via \definecolor); no longer sets
  2185 "a4paper" option (unnecessary or even intrusive).
  2186 
  2187 * Antiquotation @{lemma A method} proves proposition A by the given
  2188 method (either a method name or a method name plus (optional) method
  2189 arguments in parentheses) and prints A just like @{prop A}.
  2190 
  2191 
  2192 *** HOL ***
  2193 
  2194 * New primrec package.  Specification syntax conforms in style to
  2195 definition/function/....  No separate induction rule is provided.  The
  2196 "primrec" command distinguishes old-style and new-style specifications
  2197 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2198 When adjusting theories, beware: constants stemming from new-style
  2199 primrec specifications have authentic syntax.
  2200 
  2201 * Metis prover is now an order of magnitude faster, and also works
  2202 with multithreading.
  2203 
  2204 * Metis: the maximum number of clauses that can be produced from a
  2205 theorem is now given by the attribute max_clauses.  Theorems that
  2206 exceed this number are ignored, with a warning printed.
  2207 
  2208 * Sledgehammer no longer produces structured proofs by default. To
  2209 enable, declare [[sledgehammer_full = true]].  Attributes
  2210 reconstruction_modulus, reconstruction_sorts renamed
  2211 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2212 
  2213 * Method "induct_scheme" derives user-specified induction rules
  2214 from well-founded induction and completeness of patterns. This factors
  2215 out some operations that are done internally by the function package
  2216 and makes them available separately.  See
  2217 src/HOL/ex/Induction_Scheme.thy for examples.
  2218 
  2219 * More flexible generation of measure functions for termination
  2220 proofs: Measure functions can be declared by proving a rule of the
  2221 form "is_measure f" and giving it the [measure_function] attribute.
  2222 The "is_measure" predicate is logically meaningless (always true), and
  2223 just guides the heuristic.  To find suitable measure functions, the
  2224 termination prover sets up the goal "is_measure ?f" of the appropriate
  2225 type and generates all solutions by prolog-style backwards proof using
  2226 the declared rules.
  2227 
  2228 This setup also deals with rules like 
  2229 
  2230   "is_measure f ==> is_measure (list_size f)"
  2231 
  2232 which accommodates nested datatypes that recurse through lists.
  2233 Similar rules are predeclared for products and option types.
  2234 
  2235 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2236 
  2237   INCOMPATIBILITIES:
  2238 
  2239   - Definitions of overloaded constants on sets have to be replaced by
  2240     definitions on => and bool.
  2241 
  2242   - Some definitions of overloaded operators on sets can now be proved
  2243     using the definitions of the operators on => and bool.  Therefore,
  2244     the following theorems have been renamed:
  2245 
  2246       subset_def   -> subset_eq
  2247       psubset_def  -> psubset_eq
  2248       set_diff_def -> set_diff_eq
  2249       Compl_def    -> Compl_eq
  2250       Sup_set_def  -> Sup_set_eq
  2251       Inf_set_def  -> Inf_set_eq
  2252       sup_set_def  -> sup_set_eq
  2253       inf_set_def  -> inf_set_eq
  2254 
  2255   - Due to the incompleteness of the HO unification algorithm, some
  2256     rules such as subst may require manual instantiation, if some of
  2257     the unknowns in the rule is a set.
  2258 
  2259   - Higher order unification and forward proofs:
  2260     The proof pattern
  2261 
  2262       have "P (S::'a set)" <...>
  2263       then have "EX S. P S" ..
  2264 
  2265     no longer works (due to the incompleteness of the HO unification
  2266     algorithm) and must be replaced by the pattern
  2267 
  2268       have "EX S. P S"
  2269       proof
  2270         show "P S" <...>
  2271       qed
  2272 
  2273   - Calculational reasoning with subst (or similar rules):
  2274     The proof pattern
  2275 
  2276       have "P (S::'a set)" <...>
  2277       also have "S = T" <...>
  2278       finally have "P T" .
  2279 
  2280     no longer works (for similar reasons as the previous example) and
  2281     must be replaced by something like
  2282 
  2283       have "P (S::'a set)" <...>
  2284       moreover have "S = T" <...>
  2285       ultimately have "P T" by simp
  2286 
  2287   - Tactics or packages written in ML code:
  2288     Code performing pattern matching on types via
  2289 
  2290       Type ("set", [T]) => ...
  2291 
  2292     must be rewritten. Moreover, functions like strip_type or
  2293     binder_types no longer return the right value when applied to a
  2294     type of the form
  2295 
  2296       T1 => ... => Tn => U => bool
  2297 
  2298     rather than
  2299 
  2300       T1 => ... => Tn => U set
  2301 
  2302 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2303 Wellfounded_Relations to theory Wellfounded.
  2304 
  2305 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2306 
  2307 * Class finite no longer treats UNIV as class parameter.  Use class
  2308 enum from theory Library/Enum instead to achieve a similar effect.
  2309 INCOMPATIBILITY.
  2310 
  2311 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2312 and "Cons".  INCOMPATIBILITY.
  2313 
  2314 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2315 Potential INCOMPATIBILITY.
  2316 
  2317 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2318 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2319 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2320 
  2321 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2322 the same name in theory Orderings:
  2323 
  2324   less_trans
  2325   less_linear
  2326   le_imp_less_or_eq
  2327   le_less_trans
  2328   less_le_trans
  2329   less_not_sym
  2330   less_asym
  2331 
  2332 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2333 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2334 and different variable names.
  2335 
  2336 * Library/Option_ord.thy: Canonical order on option type.
  2337 
  2338 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2339 finite maps.
  2340 
  2341 * Library/Countable.thy: Type class for countable types.
  2342 
  2343 * Theory Int: The representation of numerals has changed.  The infix
  2344 operator BIT and the bit datatype with constructors B0 and B1 have
  2345 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2346 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2347 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2348 accordingly.
  2349 
  2350 * Theory Nat: definition of <= and < on natural numbers no longer
  2351 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2352 le_def and less_def have disappeared.  Consider lemmas not_less
  2353 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2354 
  2355 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2356 (whose purpose mainly is for various fold_set functionals) have been
  2357 abandoned in favor of the existing algebraic classes
  2358 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2359 lower_semilattice (resp. upper_semilattice) and linorder.
  2360 INCOMPATIBILITY.
  2361 
  2362 * Theory Transitive_Closure: induct and cases rules now declare proper
  2363 case_names ("base" and "step").  INCOMPATIBILITY.
  2364 
  2365 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2366 lattices.  The form set-specific version is available as
  2367 Inductive.lfp_ordinal_induct_set.
  2368 
  2369 * Renamed theorems "power.simps" to "power_int.simps".
  2370 INCOMPATIBILITY.
  2371 
  2372 * Class semiring_div provides basic abstract properties of semirings
  2373 with division and modulo operations.  Subsumes former class dvd_mod.
  2374 
  2375 * Merged theories IntDef, Numeral and IntArith into unified theory
  2376 Int.  INCOMPATIBILITY.
  2377 
  2378 * Theory Library/Code_Index: type "index" now represents natural
  2379 numbers rather than integers.  INCOMPATIBILITY.
  2380 
  2381 * New class "uminus" with operation "uminus" (split of from class
  2382 "minus" which now only has operation "minus", binary).
  2383 INCOMPATIBILITY.
  2384 
  2385 * Constants "card", "internal_split", "option_map" now with authentic
  2386 syntax.  INCOMPATIBILITY.
  2387 
  2388 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2389 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2390 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2391 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2392 Sup_set_def, le_def, less_def, option_map_def now with object
  2393 equality.  INCOMPATIBILITY.
  2394 
  2395 * Records. Removed K_record, and replaced it by pure lambda term
  2396 %x. c. The simplifier setup is now more robust against eta expansion.
  2397 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2398 
  2399 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2400 
  2401 * Library/ListVector: new theory of arithmetic vector operations.
  2402 
  2403 * Library/Order_Relation: new theory of various orderings as sets of
  2404 pairs.  Defines preorders, partial orders, linear orders and
  2405 well-orders on sets and on types.
  2406 
  2407 
  2408 *** ZF ***
  2409 
  2410 * Renamed some theories to allow to loading both ZF and HOL in the
  2411 same session:
  2412 
  2413   Datatype  -> Datatype_ZF
  2414   Inductive -> Inductive_ZF
  2415   Int       -> Int_ZF
  2416   IntDiv    -> IntDiv_ZF
  2417   Nat       -> Nat_ZF
  2418   List      -> List_ZF
  2419   Main      -> Main_ZF
  2420 
  2421 INCOMPATIBILITY: ZF theories that import individual theories below
  2422 Main might need to be adapted.  Regular theory Main is still
  2423 available, as trivial extension of Main_ZF.
  2424 
  2425 
  2426 *** ML ***
  2427 
  2428 * ML within Isar: antiquotation @{const name} or @{const
  2429 name(typargs)} produces statically-checked Const term.
  2430 
  2431 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2432 (of the same name).  Removed obsolete print command.
  2433 
  2434 * Removed obsolete "use_legacy_bindings" function.
  2435 
  2436 * The ``print mode'' is now a thread-local value derived from a global
  2437 template (the former print_mode reference), thus access becomes
  2438 non-critical.  The global print_mode reference is for session
  2439 management only; user-code should use print_mode_value,
  2440 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2441 
  2442 * Functions system/system_out provide a robust way to invoke external
  2443 shell commands, with propagation of interrupts (requires Poly/ML
  2444 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2445 
  2446 
  2447 *** System ***
  2448 
  2449 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2450 in accordance with Proof General 3.7, which prefers GNU emacs.
  2451 
  2452 * isatool tty runs Isabelle process with plain tty interaction;
  2453 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2454 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2455 
  2456 * isatool browser now works with Cygwin as well, using general
  2457 "javapath" function defined in Isabelle process environment.
  2458 
  2459 * YXML notation provides a simple and efficient alternative to
  2460 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2461 isatool yxml as described in the Isabelle system manual.
  2462 
  2463 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2464 provides general wrapper for managing an Isabelle process in a robust
  2465 fashion, with ``cooked'' output from stdin/stderr.
  2466 
  2467 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2468 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2469 
  2470 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2471 way of changing the user's settings is via
  2472 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2473 script.
  2474 
  2475 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2476 cores of the underlying machine, which is a good starting point for
  2477 optimal performance tuning.  The corresponding usedir option -M allows
  2478 "max" as an alias for "0".  WARNING: does not work on certain versions
  2479 of Mac OS (with Poly/ML 5.1).
  2480 
  2481 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2482 adverse effect of Isabelle flooding interactive front-ends (notably
  2483 ProofGeneral / XEmacs).
  2484 
  2485 
  2486 
  2487 New in Isabelle2007 (November 2007)
  2488 -----------------------------------
  2489 
  2490 *** General ***
  2491 
  2492 * More uniform information about legacy features, notably a
  2493 warning/error of "Legacy feature: ...", depending on the state of the
  2494 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2495 legacy features will disappear eventually.
  2496 
  2497 * Theory syntax: the header format ``theory A = B + C:'' has been
  2498 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2499 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2500 
  2501 * Theory syntax: the old non-Isar theory file format has been
  2502 discontinued altogether.  Note that ML proof scripts may still be used
  2503 with Isar theories; migration is usually quite simple with the ML
  2504 function use_legacy_bindings.  INCOMPATIBILITY.
  2505 
  2506 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2507 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2508 quotes.
  2509 
  2510 * Theory loader: be more serious about observing the static theory
  2511 header specifications (including optional directories), but not the
  2512 accidental file locations of previously successful loads.  The strict
  2513 update policy of former update_thy is now already performed by
  2514 use_thy, so the former has been removed; use_thys updates several
  2515 theories simultaneously, just as 'imports' within a theory header
  2516 specification, but without merging the results.  Potential
  2517 INCOMPATIBILITY: may need to refine theory headers and commands
  2518 ROOT.ML which depend on load order.
  2519 
  2520 * Theory loader: optional support for content-based file
  2521 identification, instead of the traditional scheme of full physical
  2522 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2523 (cf. the system manual).  The new scheme allows to work with
  2524 non-finished theories in persistent session images, such that source
  2525 files may be moved later on without requiring reloads.
  2526 
  2527 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2528 file (with the same base name as the theory) are considered a legacy
  2529 feature, which will disappear eventually. Even now, the theory loader
  2530 no longer maintains dependencies on such files.
  2531 
  2532 * Syntax: the scope for resolving ambiguities via type-inference is
  2533 now limited to individual terms, instead of whole simultaneous
  2534 specifications as before. This greatly reduces the complexity of the
  2535 syntax module and improves flexibility by separating parsing and
  2536 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2537 'fixes' etc.) are required in rare situations.
  2538 
  2539 * Syntax: constants introduced by new-style packages ('definition',
  2540 'abbreviation' etc.) are passed through the syntax module in
  2541 ``authentic mode''. This means that associated mixfix annotations
  2542 really stick to such constants, independently of potential name space
  2543 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2544 trees are represented slightly differently, may need to adapt syntax
  2545 translations accordingly. Use CONST marker in 'translations' and
  2546 @{const_syntax} antiquotation in 'parse_translation' etc.
  2547 
  2548 * Legacy goal package: reduced interface to the bare minimum required
  2549 to keep existing proof scripts running.  Most other user-level
  2550 functions are now part of the OldGoals structure, which is *not* open
  2551 by default (consider isatool expandshort before open OldGoals).
  2552 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2553 these tend to cause confusion about the actual goal (!) context being
  2554 used here, which is not necessarily the same as the_context().
  2555 
  2556 * Command 'find_theorems': supports "*" wild-card in "name:"
  2557 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2558 support a specific search form (see ProofGeneral/CHANGES).
  2559 
  2560 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2561 by default, which means that "prems" (and also "fixed variables") are
  2562 suppressed from proof state output.  Note that the ProofGeneral
  2563 settings mechanism allows to change and save options persistently, but
  2564 older versions of Isabelle will fail to start up if a negative prems
  2565 limit is imposed.
  2566 
  2567 * Local theory targets may be specified by non-nested blocks of
  2568 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2569 contain definitions, theorems etc., including any derived mechanism
  2570 that has been implemented on top of these primitives.  This concept
  2571 generalizes the existing ``theorem (in ...)'' towards more versatility
  2572 and scalability.
  2573 
  2574 * Proof General interface: proper undo of final 'end' command;
  2575 discontinued Isabelle/classic mode (ML proof scripts).
  2576 
  2577 
  2578 *** Document preparation ***
  2579 
  2580 * Added antiquotation @{theory name} which prints the given name,
  2581 after checking that it refers to a valid ancestor theory in the
  2582 current context.
  2583 
  2584 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2585 check the given source text as ML type/structure, printing verbatim.
  2586 
  2587 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2588 "c args == rhs" given in the current context.  (Any number of
  2589 arguments may be given on the LHS.)
  2590 
  2591 
  2592 *** Pure ***
  2593 
  2594 * The 'class' package offers a combination of axclass and locale to
  2595 achieve Haskell-like type classes in Isabelle.  Definitions and
  2596 theorems within a class context produce both relative results (with
  2597 implicit parameters according to the locale context), and polymorphic
  2598 constants with qualified polymorphism (according to the class
  2599 context).  Within the body context of a 'class' target, a separate
  2600 syntax layer ("user space type system") takes care of converting
  2601 between global polymorphic consts and internal locale representation.
  2602 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2603 "isatool doc classes" provides a tutorial.
  2604 
  2605 * Generic code generator framework allows to generate executable
  2606 code for ML and Haskell (including Isabelle classes).  A short usage
  2607 sketch:
  2608 
  2609     internal compilation:
  2610         export_code <list of constants (term syntax)> in SML
  2611     writing SML code to a file:
  2612         export_code <list of constants (term syntax)> in SML <filename>
  2613     writing OCaml code to a file:
  2614         export_code <list of constants (term syntax)> in OCaml <filename>
  2615     writing Haskell code to a bunch of files:
  2616         export_code <list of constants (term syntax)> in Haskell <filename>
  2617 
  2618     evaluating closed propositions to True/False using code generation:
  2619         method ``eval''
  2620 
  2621 Reasonable default setup of framework in HOL.
  2622 
  2623 Theorem attributs for selecting and transforming function equations theorems:
  2624 
  2625     [code fun]:        select a theorem as function equation for a specific constant
  2626     [code fun del]:    deselect a theorem as function equation for a specific constant
  2627     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2628     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2629 
  2630 User-defined serializations (target in {SML, OCaml, Haskell}):
  2631 
  2632     code_const <and-list of constants (term syntax)>
  2633       {(target) <and-list of const target syntax>}+
  2634 
  2635     code_type <and-list of type constructors>
  2636       {(target) <and-list of type target syntax>}+
  2637 
  2638     code_instance <and-list of instances>
  2639       {(target)}+
  2640         where instance ::= <type constructor> :: <class>
  2641 
  2642     code_class <and_list of classes>
  2643       {(target) <and-list of class target syntax>}+
  2644         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2645 
  2646 code_instance and code_class only are effective to target Haskell.
  2647 
  2648 For example usage see src/HOL/ex/Codegenerator.thy and
  2649 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2650 generation from Isabelle/HOL theories is available via "isatool doc
  2651 codegen".
  2652 
  2653 * Code generator: consts in 'consts_code' Isar commands are now
  2654 referred to by usual term syntax (including optional type
  2655 annotations).
  2656 
  2657 * Command 'no_translations' removes translation rules from theory
  2658 syntax.
  2659 
  2660 * Overloaded definitions are now actually checked for acyclic
  2661 dependencies.  The overloading scheme is slightly more general than
  2662 that of Haskell98, although Isabelle does not demand an exact
  2663 correspondence to type class and instance declarations.
  2664 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2665 exotic versions of overloading -- at the discretion of the user!
  2666 
  2667 Polymorphic constants are represented via type arguments, i.e. the
  2668 instantiation that matches an instance against the most general
  2669 declaration given in the signature.  For example, with the declaration
  2670 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2671 as c(nat).  Overloading is essentially simultaneous structural
  2672 recursion over such type arguments.  Incomplete specification patterns
  2673 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2674 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2675 Command 'print_theory' outputs the normalized system of recursive
  2676 equations, see section "definitions".
  2677 
  2678 * Configuration options are maintained within the theory or proof
  2679 context (with name and type bool/int/string), providing a very simple
  2680 interface to a poor-man's version of general context data.  Tools may
  2681 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2682 these values using Config.get etc.  Users may change options via an
  2683 associated attribute of the same name.  This form of context
  2684 declaration works particularly well with commands 'declare' or
  2685 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2686 very easy to avoid global references, which would not observe Isar
  2687 toplevel undo/redo and fail to work with multithreading.
  2688 
  2689 Various global ML references of Pure and HOL have been turned into
  2690 configuration options:
  2691 
  2692   Unify.search_bound		unify_search_bound
  2693   Unify.trace_bound		unify_trace_bound
  2694   Unify.trace_simp		unify_trace_simp
  2695   Unify.trace_types		unify_trace_types
  2696   Simplifier.simp_depth_limit	simp_depth_limit
  2697   Blast.depth_limit		blast_depth_limit
  2698   DatatypeProp.dtK		datatype_distinctness_limit
  2699   fast_arith_neq_limit  	fast_arith_neq_limit
  2700   fast_arith_split_limit	fast_arith_split_limit
  2701 
  2702 * Named collections of theorems may be easily installed as context
  2703 data using the functor NamedThmsFun (see also
  2704 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2705 attributes; there is also a toplevel print command.  This facility is
  2706 just a common case of general context data, which is the preferred way
  2707 for anything more complex than just a list of facts in canonical
  2708 order.
  2709 
  2710 * Isar: command 'declaration' augments a local theory by generic
  2711 declaration functions written in ML.  This enables arbitrary content
  2712 being added to the context, depending on a morphism that tells the
  2713 difference of the original declaration context wrt. the application
  2714 context encountered later on.
  2715 
  2716 * Isar: proper interfaces for simplification procedures.  Command
  2717 'simproc_setup' declares named simprocs (with match patterns, and body
  2718 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2719 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2720 
  2721 * Isar: an extra pair of brackets around attribute declarations
  2722 abbreviates a theorem reference involving an internal dummy fact,
  2723 which will be ignored later --- only the effect of the attribute on
  2724 the background context will persist.  This form of in-place
  2725 declarations is particularly useful with commands like 'declare' and
  2726 'using', for example ``have A using [[simproc a]] by simp''.
  2727 
  2728 * Isar: method "assumption" (and implicit closing of subproofs) now
  2729 takes simple non-atomic goal assumptions into account: after applying
  2730 an assumption as a rule the resulting subgoals are solved by atomic
  2731 assumption steps.  This is particularly useful to finish 'obtain'
  2732 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2733 without referring to the original premise "!!x. P x ==> thesis" in the
  2734 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2735 more permissive.
  2736 
  2737 * Isar: implicit use of prems from the Isar proof context is
  2738 considered a legacy feature.  Common applications like ``have A .''
  2739 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2740 referencing facts explicitly here improves readability and
  2741 maintainability of proof texts.
  2742 
  2743 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2744 the obtained context from the course of reasoning!  For example:
  2745 
  2746   assume "EX x y. A x & B y"   -- "any previous fact"
  2747   then guess x and y by clarify
  2748 
  2749 This technique is potentially adventurous, depending on the facts and
  2750 proof tools being involved here.
  2751 
  2752 * Isar: known facts from the proof context may be specified as literal
  2753 propositions, using ASCII back-quote syntax.  This works wherever
  2754 named facts used to be allowed so far, in proof commands, proof
  2755 methods, attributes etc.  Literal facts are retrieved from the context
  2756 according to unification of type and term parameters.  For example,
  2757 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2758 theorems in the current context, then these are valid literal facts:
  2759 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2760 
  2761 There is also a proof method "fact" which does the same composition
  2762 for explicit goal states, e.g. the following proof texts coincide with
  2763 certain special cases of literal facts:
  2764 
  2765   have "A" by fact                 ==  note `A`
  2766   have "A ==> B" by fact           ==  note `A ==> B`
  2767   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2768   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2769 
  2770 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2771 outer syntax.  Thus symbolic identifiers may be used without
  2772 additional white space in declarations like this: ``assume *: A''.
  2773 
  2774 * Isar: 'print_facts' prints all local facts of the current context,
  2775 both named and unnamed ones.
  2776 
  2777 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2778 
  2779   def x == "t" and y == "u"
  2780 
  2781 * Isar: added command 'unfolding', which is structurally similar to
  2782 'using', but affects both the goal state and facts by unfolding given
  2783 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2784 'unfolded' attribute may be replaced by first-class proof text.
  2785 
  2786 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2787 and command 'unfolding' now all support object-level equalities
  2788 (potentially conditional).  The underlying notion of rewrite rule is
  2789 analogous to the 'rule_format' attribute, but *not* that of the
  2790 Simplifier (which is usually more generous).
  2791 
  2792 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2793 premises of a theorem by n. Useful in conjunction with drule.
  2794 
  2795 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2796 method expression within a sandbox consisting of the first N
  2797 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2798 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2799 simplifies all new goals that emerge from applying rule foo to the
  2800 originally first one.
  2801 
  2802 * Isar: schematic goals are no longer restricted to higher-order
  2803 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2804 expected.
  2805 
  2806 * Isar: the conclusion of a long theorem statement is now either
  2807 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2808 (essentially a disjunction of cases with local parameters and
  2809 assumptions).  The latter allows to express general elimination rules
  2810 adequately; in this notation common elimination rules look like this:
  2811 
  2812   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2813     assumes "EX x. P x"
  2814     obtains x where "P x"
  2815 
  2816   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2817     assumes "A & B"
  2818     obtains A and B
  2819 
  2820   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2821     assumes "A | B"
  2822     obtains
  2823       A
  2824     | B
  2825 
  2826 The subsequent classical rules even refer to the formal "thesis"
  2827 explicitly:
  2828 
  2829   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2830     obtains "~ thesis"
  2831 
  2832   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2833     obtains "thesis ==> something"
  2834 
  2835 The actual proof of an 'obtains' statement is analogous to that of the
  2836 Isar proof element 'obtain', only that there may be several cases.
  2837 Optional case names may be specified in parentheses; these will be
  2838 available both in the present proof and as annotations in the
  2839 resulting rule, for later use with the 'cases' method (cf. attribute
  2840 case_names).
  2841 
  2842 * Isar: the assumptions of a long theorem statement are available as
  2843 "assms" fact in the proof context.  This is more appropriate than the
  2844 (historical) "prems", which refers to all assumptions of the current
  2845 context, including those from the target locale, proof body etc.
  2846 
  2847 * Isar: 'print_statement' prints theorems from the current theory or
  2848 proof context in long statement form, according to the syntax of a
  2849 top-level lemma.
  2850 
  2851 * Isar: 'obtain' takes an optional case name for the local context
  2852 introduction rule (default "that").
  2853 
  2854 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2855 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2856 to occur.
  2857 
  2858 * Pure: syntax "CONST name" produces a fully internalized constant
  2859 according to the current context.  This is particularly useful for
  2860 syntax translations that should refer to internal constant
  2861 representations independently of name spaces.
  2862 
  2863 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2864 instead of "FOO ". This allows multiple binder declarations to coexist
  2865 in the same context.  INCOMPATIBILITY.
  2866 
  2867 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2868 primitive that also works in a locale context (both for constants and
  2869 fixed variables). Type declaration and internal syntactic representation
  2870 of given constants retrieved from the context. Likewise, the
  2871 'no_notation' command allows to remove given syntax annotations from the
  2872 current context.
  2873 
  2874 * Isar/locales: new derived specification elements 'axiomatization',
  2875 'definition', 'abbreviation', which support type-inference, admit
  2876 object-level specifications (equality, equivalence).  See also the
  2877 isar-ref manual.  Examples:
  2878 
  2879   axiomatization
  2880     eq  (infix "===" 50) where
  2881     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2882 
  2883   definition "f x y = x + y + 1"
  2884   definition g where "g x = f x x"
  2885 
  2886   abbreviation
  2887     neq  (infix "=!=" 50) where
  2888     "x =!= y == ~ (x === y)"
  2889 
  2890 These specifications may be also used in a locale context.  Then the
  2891 constants being introduced depend on certain fixed parameters, and the
  2892 constant name is qualified by the locale base name.  An internal
  2893 abbreviation takes care for convenient input and output, making the
  2894 parameters implicit and using the original short name.  See also
  2895 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2896 entities from a monomorphic theory.
  2897 
  2898 Presently, abbreviations are only available 'in' a target locale, but
  2899 not inherited by general import expressions.  Also note that
  2900 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2901 'translations' in common applications.  The "no_abbrevs" print mode
  2902 prevents folding of abbreviations in term output.
  2903 
  2904 Concrete syntax is attached to specified constants in internal form,
  2905 independently of name spaces.  The parse tree representation is
  2906 slightly different -- use 'notation' instead of raw 'syntax', and
  2907 'translations' with explicit "CONST" markup to accommodate this.
  2908 
  2909 * Pure/Isar: unified syntax for new-style specification mechanisms
  2910 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2911 full type inference and dummy patterns ("_").  For example:
  2912 
  2913   definition "K x _ = x"
  2914 
  2915   inductive conj for A B
  2916   where "A ==> B ==> conj A B"
  2917 
  2918 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2919 the current context.  Print mode "no_abbrevs" prevents inversion of
  2920 abbreviations on output.
  2921 
  2922 * Isar/locales: improved parameter handling: use of locales "var" and
  2923 "struct" no longer necessary; - parameter renamings are no longer
  2924 required to be injective.  For example, this allows to define
  2925 endomorphisms as locale endom = homom mult mult h.
  2926 
  2927 * Isar/locales: changed the way locales with predicates are defined.
  2928 Instead of accumulating the specification, the imported expression is
  2929 now an interpretation.  INCOMPATIBILITY: different normal form of
  2930 locale expressions.  In particular, in interpretations of locales with
  2931 predicates, goals repesenting already interpreted fragments are not
  2932 removed automatically.  Use methods `intro_locales' and
  2933 `unfold_locales'; see below.
  2934 
  2935 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2936 provide backward reasoning on locales predicates.  The methods are
  2937 aware of interpretations and discharge corresponding goals.
  2938 `intro_locales' is less aggressive then `unfold_locales' and does not
  2939 unfold predicates to assumptions.
  2940 
  2941 * Isar/locales: the order in which locale fragments are accumulated
  2942 has changed.  This enables to override declarations from fragments due
  2943 to interpretations -- for example, unwanted simp rules.
  2944 
  2945 * Isar/locales: interpretation in theories and proof contexts has been
  2946 extended.  One may now specify (and prove) equations, which are
  2947 unfolded in interpreted theorems.  This is useful for replacing
  2948 defined concepts (constants depending on locale parameters) by
  2949 concepts already existing in the target context.  Example:
  2950 
  2951   interpretation partial_order ["op <= :: [int, int] => bool"]
  2952     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2953 
  2954 Typically, the constant `partial_order.less' is created by a
  2955 definition specification element in the context of locale
  2956 partial_order.
  2957 
  2958 * Method "induct": improved internal context management to support
  2959 local fixes and defines on-the-fly. Thus explicit meta-level
  2960 connectives !!  and ==> are rarely required anymore in inductive goals
  2961 (using object-logic connectives for this purpose has been long
  2962 obsolete anyway). Common proof patterns are explained in
  2963 src/HOL/Induct/Common_Patterns.thy, see also
  2964 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2965 examples.
  2966 
  2967 * Method "induct": improved handling of simultaneous goals. Instead of
  2968 introducing object-level conjunction, the statement is now split into
  2969 several conclusions, while the corresponding symbolic cases are nested
  2970 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2971 see src/HOL/Induct/Common_Patterns.thy, for example.
  2972 
  2973 * Method "induct": mutual induction rules are now specified as a list
  2974 of rule sharing the same induction cases. HOL packages usually provide
  2975 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2976 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2977 mutual induction rules differently, i.e. like this:
  2978 
  2979   (induct rule: foo_bar.inducts)
  2980   (induct set: foo bar)
  2981   (induct pred: foo bar)
  2982   (induct type: foo bar)
  2983 
  2984 The ML function ProjectRule.projections turns old-style rules into the
  2985 new format.
  2986 
  2987 * Method "coinduct": dual of induction, see
  2988 src/HOL/Library/Coinductive_List.thy for various examples.
  2989 
  2990 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2991 considered a legacy feature.
  2992 
  2993 * Attribute "symmetric" produces result with standardized schematic
  2994 variables (index 0).  Potential INCOMPATIBILITY.
  2995 
  2996 * Simplifier: by default the simplifier trace only shows top level
  2997 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2998 default. Thus there is less danger of being flooded by the trace. The
  2999 trace indicates where parts have been suppressed.
  3000   
  3001 * Provers/classical: removed obsolete classical version of elim_format
  3002 attribute; classical elim/dest rules are now treated uniformly when
  3003 manipulating the claset.
  3004 
  3005 * Provers/classical: stricter checks to ensure that supplied intro,
  3006 dest and elim rules are well-formed; dest and elim rules must have at
  3007 least one premise.
  3008 
  3009 * Provers/classical: attributes dest/elim/intro take an optional
  3010 weight argument for the rule (just as the Pure versions).  Weights are
  3011 ignored by automated tools, but determine the search order of single
  3012 rule steps.
  3013 
  3014 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3015 where the body does not mention the bound variable.  Note that dummy
  3016 patterns implicitly depend on their context of bounds, which makes
  3017 "{_. _}" match any set comprehension as expected.  Potential
  3018 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3019 constant "_idtdummy" in the binding position.
  3020 
  3021 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3022 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3023 for example "A -> B" => "Pi A (%_. B)".
  3024 
  3025 * Pure: 'class_deps' command visualizes the subclass relation, using
  3026 the graph browser tool.
  3027 
  3028 * Pure: 'print_theory' now suppresses certain internal declarations by
  3029 default; use '!' option for full details.
  3030 
  3031 
  3032 *** HOL ***
  3033 
  3034 * Method "metis" proves goals by applying the Metis general-purpose
  3035 resolution prover (see also http://gilith.com/software/metis/).
  3036 Examples are in the directory MetisExamples.  WARNING: the
  3037 Isabelle/HOL-Metis integration does not yet work properly with
  3038 multi-threading.
  3039   
  3040 * Command 'sledgehammer' invokes external automatic theorem provers as
  3041 background processes.  It generates calls to the "metis" method if
  3042 successful. These can be pasted into the proof.  Users do not have to
  3043 wait for the automatic provers to return.  WARNING: does not really
  3044 work with multi-threading.
  3045 
  3046 * New "auto_quickcheck" feature tests outermost goal statements for
  3047 potential counter-examples.  Controlled by ML references
  3048 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3049 5000 milliseconds).  Fails silently if statements is outside of
  3050 executable fragment, or any other codgenerator problem occurs.
  3051 
  3052 * New constant "undefined" with axiom "undefined x = undefined".
  3053 
  3054 * Added class "HOL.eq", allowing for code generation with polymorphic
  3055 equality.
  3056 
  3057 * Some renaming of class constants due to canonical name prefixing in
  3058 the new 'class' package:
  3059 
  3060     HOL.abs ~> HOL.abs_class.abs
  3061     HOL.divide ~> HOL.divide_class.divide
  3062     0 ~> HOL.zero_class.zero
  3063     1 ~> HOL.one_class.one
  3064     op + ~> HOL.plus_class.plus
  3065     op - ~> HOL.minus_class.minus
  3066     uminus ~> HOL.minus_class.uminus
  3067     op * ~> HOL.times_class.times
  3068     op < ~> HOL.ord_class.less
  3069     op <= > HOL.ord_class.less_eq
  3070     Nat.power ~> Power.power_class.power
  3071     Nat.size ~> Nat.size_class.size
  3072     Numeral.number_of ~> Numeral.number_class.number_of
  3073     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3074     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3075     Orderings.min ~> Orderings.ord_class.min
  3076     Orderings.max ~> Orderings.ord_class.max
  3077     Divides.op div ~> Divides.div_class.div
  3078     Divides.op mod ~> Divides.div_class.mod
  3079     Divides.op dvd ~> Divides.div_class.dvd
  3080 
  3081 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3082 
  3083 a) User-defined constants using any of the names "plus", "minus",
  3084 "times", "less" or "less_eq". The standard syntax translations for
  3085 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3086 names.
  3087 
  3088 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3089 INCOMPATIBILITY: use more specific names.
  3090 
  3091 c) Permutative equations (e.g. "a + b = b + a")
  3092 Since the change of names also changes the order of terms, permutative
  3093 rewrite rules may get applied in a different order. Experience shows
  3094 that this is rarely the case (only two adaptions in the whole Isabelle
  3095 distribution).  INCOMPATIBILITY: rewrite proofs
  3096 
  3097 d) ML code directly refering to constant names
  3098 This in general only affects hand-written proof tactics, simprocs and
  3099 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3100 Consider using @{const_name} antiquotation.
  3101 
  3102 * New class "default" with associated constant "default".
  3103 
  3104 * Function "sgn" is now overloaded and available on int, real, complex
  3105 (and other numeric types), using class "sgn".  Two possible defs of
  3106 sgn are given as equational assumptions in the classes sgn_if and
  3107 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3108 INCOMPATIBILITY.
  3109 
  3110 * Locale "partial_order" now unified with class "order" (cf. theory
  3111 Orderings), added parameter "less".  INCOMPATIBILITY.
  3112 
  3113 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3114 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3115 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3116 
  3117 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3118 changed order of proof goals in instance proofs.
  3119 
  3120 * The transitivity reasoner for partial and linear orders is set up
  3121 for classes "order" and "linorder".  Instances of the reasoner are available
  3122 in all contexts importing or interpreting the corresponding locales.
  3123 Method "order" invokes the reasoner separately; the reasoner
  3124 is also integrated with the Simplifier as a solver.  Diagnostic
  3125 command 'print_orders' shows the available instances of the reasoner
  3126 in the current context.
  3127 
  3128 * Localized monotonicity predicate in theory "Orderings"; integrated
  3129 lemmas max_of_mono and min_of_mono with this predicate.
  3130 INCOMPATIBILITY.
  3131 
  3132 * Formulation of theorem "dense" changed slightly due to integration
  3133 with new class dense_linear_order.
  3134 
  3135 * Uniform lattice theory development in HOL.
  3136 
  3137     constants "meet" and "join" now named "inf" and "sup"
  3138     constant "Meet" now named "Inf"
  3139 
  3140     classes "meet_semilorder" and "join_semilorder" now named
  3141       "lower_semilattice" and "upper_semilattice"
  3142     class "lorder" now named "lattice"
  3143     class "comp_lat" now named "complete_lattice"
  3144 
  3145     Instantiation of lattice classes allows explicit definitions
  3146     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3147 
  3148   INCOMPATIBILITY.  Theorem renames:
  3149 
  3150     meet_left_le            ~> inf_le1
  3151     meet_right_le           ~> inf_le2
  3152     join_left_le            ~> sup_ge1
  3153     join_right_le           ~> sup_ge2
  3154     meet_join_le            ~> inf_sup_ord
  3155     le_meetI                ~> le_infI
  3156     join_leI                ~> le_supI
  3157     le_meet                 ~> le_inf_iff
  3158     le_join                 ~> ge_sup_conv
  3159     meet_idempotent         ~> inf_idem
  3160     join_idempotent         ~> sup_idem
  3161     meet_comm               ~> inf_commute
  3162     join_comm               ~> sup_commute
  3163     meet_leI1               ~> le_infI1
  3164     meet_leI2               ~> le_infI2
  3165     le_joinI1               ~> le_supI1
  3166     le_joinI2               ~> le_supI2
  3167     meet_assoc              ~> inf_assoc
  3168     join_assoc              ~> sup_assoc
  3169     meet_left_comm          ~> inf_left_commute
  3170     meet_left_idempotent    ~> inf_left_idem
  3171     join_left_comm          ~> sup_left_commute
  3172     join_left_idempotent    ~> sup_left_idem
  3173     meet_aci                ~> inf_aci
  3174     join_aci                ~> sup_aci
  3175     le_def_meet             ~> le_iff_inf
  3176     le_def_join             ~> le_iff_sup
  3177     join_absorp2            ~> sup_absorb2
  3178     join_absorp1            ~> sup_absorb1
  3179     meet_absorp1            ~> inf_absorb1
  3180     meet_absorp2            ~> inf_absorb2
  3181     meet_join_absorp        ~> inf_sup_absorb
  3182     join_meet_absorp        ~> sup_inf_absorb
  3183     distrib_join_le         ~> distrib_sup_le
  3184     distrib_meet_le         ~> distrib_inf_le
  3185 
  3186     add_meet_distrib_left   ~> add_inf_distrib_left
  3187     add_join_distrib_left   ~> add_sup_distrib_left
  3188     is_join_neg_meet        ~> is_join_neg_inf
  3189     is_meet_neg_join        ~> is_meet_neg_sup
  3190     add_meet_distrib_right  ~> add_inf_distrib_right
  3191     add_join_distrib_right  ~> add_sup_distrib_right
  3192     add_meet_join_distribs  ~> add_sup_inf_distribs
  3193     join_eq_neg_meet        ~> sup_eq_neg_inf
  3194     meet_eq_neg_join        ~> inf_eq_neg_sup
  3195     add_eq_meet_join        ~> add_eq_inf_sup
  3196     meet_0_imp_0            ~> inf_0_imp_0
  3197     join_0_imp_0            ~> sup_0_imp_0
  3198     meet_0_eq_0             ~> inf_0_eq_0
  3199     join_0_eq_0             ~> sup_0_eq_0
  3200     neg_meet_eq_join        ~> neg_inf_eq_sup
  3201     neg_join_eq_meet        ~> neg_sup_eq_inf
  3202     join_eq_if              ~> sup_eq_if
  3203 
  3204     mono_meet               ~> mono_inf
  3205     mono_join               ~> mono_sup
  3206     meet_bool_eq            ~> inf_bool_eq
  3207     join_bool_eq            ~> sup_bool_eq
  3208     meet_fun_eq             ~> inf_fun_eq
  3209     join_fun_eq             ~> sup_fun_eq
  3210     meet_set_eq             ~> inf_set_eq
  3211     join_set_eq             ~> sup_set_eq
  3212     meet1_iff               ~> inf1_iff
  3213     meet2_iff               ~> inf2_iff
  3214     meet1I                  ~> inf1I
  3215     meet2I                  ~> inf2I
  3216     meet1D1                 ~> inf1D1
  3217     meet2D1                 ~> inf2D1
  3218     meet1D2                 ~> inf1D2
  3219     meet2D2                 ~> inf2D2
  3220     meet1E                  ~> inf1E
  3221     meet2E                  ~> inf2E
  3222     join1_iff               ~> sup1_iff
  3223     join2_iff               ~> sup2_iff
  3224     join1I1                 ~> sup1I1
  3225     join2I1                 ~> sup2I1
  3226     join1I1                 ~> sup1I1
  3227     join2I2                 ~> sup1I2
  3228     join1CI                 ~> sup1CI
  3229     join2CI                 ~> sup2CI
  3230     join1E                  ~> sup1E
  3231     join2E                  ~> sup2E
  3232 
  3233     is_meet_Meet            ~> is_meet_Inf
  3234     Meet_bool_def           ~> Inf_bool_def
  3235     Meet_fun_def            ~> Inf_fun_def
  3236     Meet_greatest           ~> Inf_greatest
  3237     Meet_lower              ~> Inf_lower
  3238     Meet_set_def            ~> Inf_set_def
  3239 
  3240     Sup_def                 ~> Sup_Inf
  3241     Sup_bool_eq             ~> Sup_bool_def
  3242     Sup_fun_eq              ~> Sup_fun_def
  3243     Sup_set_eq              ~> Sup_set_def
  3244 
  3245     listsp_meetI            ~> listsp_infI
  3246     listsp_meet_eq          ~> listsp_inf_eq
  3247 
  3248     meet_min                ~> inf_min
  3249     join_max                ~> sup_max
  3250 
  3251 * Added syntactic class "size"; overloaded constant "size" now has
  3252 type "'a::size ==> bool"
  3253 
  3254 * Internal reorganisation of `size' of datatypes: size theorems
  3255 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3256 simplification rules by default!); theorems "prod.size" now named
  3257 "*.size".
  3258 
  3259 * Class "div" now inherits from class "times" rather than "type".
  3260 INCOMPATIBILITY.
  3261 
  3262 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3263 Linorder etc.  have disappeared; operations defined in terms of
  3264 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3265 
  3266 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3267 
  3268 * HOL-Word: New extensive library and type for generic, fixed size
  3269 machine words, with arithemtic, bit-wise, shifting and rotating
  3270 operations, reflection into int, nat, and bool lists, automation for
  3271 linear arithmetic (by automatic reflection into nat or int), including
  3272 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3273 arithmetic type classes, supporting automatic simplification of
  3274 numerals on all operations.
  3275 
  3276 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3277 
  3278 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3279 
  3280 * Code generator library theories:
  3281   - Code_Integer represents HOL integers by big integer literals in target
  3282     languages.
  3283   - Code_Char represents HOL characters by character literals in target
  3284     languages.
  3285   - Code_Char_chr like Code_Char, but also offers treatment of character
  3286     codes; includes Code_Integer.
  3287   - Executable_Set allows to generate code for finite sets using lists.
  3288   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3289     denominator).
  3290   - Executable_Real implements a subset of real numbers, namly those
  3291     representable by rational numbers.
  3292   - Efficient_Nat implements natural numbers by integers, which in general will
  3293     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3294     includes Code_Integer.
  3295   - Code_Index provides an additional datatype index which is mapped to
  3296     target-language built-in integers.
  3297   - Code_Message provides an additional datatype message_string which is isomorphic to
  3298     strings; messages are mapped to target-language strings.
  3299 
  3300 * New package for inductive predicates
  3301 
  3302   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3303 
  3304     inductive
  3305       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3306       for z_1 :: U_1 and ... and z_n :: U_m
  3307     where
  3308       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3309     | ...
  3310 
  3311   with full support for type-inference, rather than
  3312 
  3313     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3314 
  3315     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3316     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3317 
  3318     inductive "s z_1 ... z_m"
  3319     intros
  3320       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3321       ...
  3322 
  3323   For backward compatibility, there is a wrapper allowing inductive
  3324   sets to be defined with the new package via
  3325 
  3326     inductive_set
  3327       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3328       for z_1 :: U_1 and ... and z_n :: U_m
  3329     where
  3330       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3331     | ...
  3332 
  3333   or
  3334 
  3335     inductive_set
  3336       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3337       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3338       for z_1 :: U_1 and ... and z_n :: U_m
  3339     where
  3340       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3341     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3342     | ...
  3343 
  3344   if the additional syntax "p ..." is required.
  3345 
  3346   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3347   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3348 
  3349   INCOMPATIBILITIES:
  3350 
  3351   - Since declaration and definition of inductive sets or predicates
  3352     is no longer separated, abbreviations involving the newly
  3353     introduced sets or predicates must be specified together with the
  3354     introduction rules after the 'where' keyword (see above), rather
  3355     than before the actual inductive definition.
  3356 
  3357   - The variables in induction and elimination rules are now
  3358     quantified in the order of their occurrence in the introduction
  3359     rules, rather than in alphabetical order. Since this may break
  3360     some proofs, these proofs either have to be repaired, e.g. by
  3361     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3362     statements of the form
  3363 
  3364       case (rule_i a_i_1 ... a_i_{k_i})
  3365 
  3366     or the old order of quantification has to be restored by explicitly adding
  3367     meta-level quantifiers in the introduction rules, i.e.
  3368 
  3369       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3370 
  3371   - The format of the elimination rules is now
  3372 
  3373       p z_1 ... z_m x_1 ... x_n ==>
  3374         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3375         ==> ... ==> P
  3376 
  3377     for predicates and
  3378 
  3379       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3380         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3381         ==> ... ==> P
  3382 
  3383     for sets rather than
  3384 
  3385       x : s z_1 ... z_m ==>
  3386         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3387         ==> ... ==> P
  3388 
  3389     This may require terms in goals to be expanded to n-tuples
  3390     (e.g. using case_tac or simplification with the split_paired_all
  3391     rule) before the above elimination rule is applicable.
  3392 
  3393   - The elimination or case analysis rules for (mutually) inductive
  3394     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3395     list of rules "p_1_..._p_k.elims" is no longer available.
  3396 
  3397 * New package "function"/"fun" for general recursive functions,
  3398 supporting mutual and nested recursion, definitions in local contexts,
  3399 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3400 for small examples, and the separate tutorial on the function
  3401 package. The old recdef "package" is still available as before, but
  3402 users are encouraged to use the new package.
  3403 
  3404 * Method "lexicographic_order" automatically synthesizes termination
  3405 relations as lexicographic combinations of size measures. 
  3406 
  3407 * Case-expressions allow arbitrary constructor-patterns (including
  3408 "_") and take their order into account, like in functional
  3409 programming.  Internally, this is translated into nested
  3410 case-expressions; missing cases are added and mapped to the predefined
  3411 constant "undefined". In complicated cases printing may no longer show
  3412 the original input but the internal form. Lambda-abstractions allow
  3413 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3414 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3415 variable.
  3416 
  3417 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3418 is an abbreviation for "of_nat :: nat => int". The simplification
  3419 rules for "of_nat" have been changed to work like "int" did
  3420 previously.  Potential INCOMPATIBILITY:
  3421   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3422   - of_nat_diff and of_nat_mult are no longer default simp rules
  3423 
  3424 * Method "algebra" solves polynomial equations over (semi)rings using
  3425 Groebner bases. The (semi)ring structure is defined by locales and the
  3426 tool setup depends on that generic context. Installing the method for
  3427 a specific type involves instantiating the locale and possibly adding
  3428 declarations for computation on the coefficients.  The method is
  3429 already instantiated for natural numbers and for the axiomatic class
  3430 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3431 CALCULEMUS 2007 for the general principles underlying this
  3432 architecture of context-aware proof-tools.
  3433 
  3434 * Method "ferrack" implements quantifier elimination over
  3435 special-purpose dense linear orders using locales (analogous to
  3436 "algebra"). The method is already installed for class
  3437 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3438 rat, etc.
  3439 
  3440 * Former constant "List.op @" now named "List.append".  Use ML
  3441 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3442 circumvent possible incompatibilities when working on ML level.
  3443 
  3444 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3445 
  3446 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3447 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3448 
  3449 * New syntax for Haskell-like list comprehension (input only), eg.
  3450 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3451 
  3452 * The special syntax for function "filter" has changed from [x :
  3453 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3454 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3455 
  3456 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3457 defined on nat only, as an abbreviation for [a..<Suc b]
  3458 INCOMPATIBILITY.
  3459 
  3460 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3461 
  3462 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3463 
  3464 * New lemma collection field_simps (an extension of ring_simps) for
  3465 manipulating (in)equations involving division. Multiplies with all
  3466 denominators that can be proved to be non-zero (in equations) or
  3467 positive/negative (in inequations).
  3468 
  3469 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3470 have been improved and renamed to ring_simps, group_simps and
  3471 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3472 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3473 
  3474 * Theory Library/Commutative_Ring: switched from recdef to function
  3475 package; constants add, mul, pow now curried.  Infix syntax for
  3476 algebraic operations.
  3477 
  3478 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3479 INCOMPATIBILITY.
  3480 
  3481 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3482 INCOMPATIBILITY.
  3483 
  3484 * HOL/records: generalised field-update to take a function on the
  3485 field rather than the new value: r(|A := x|) is translated to A_update
  3486 (K x) r The K-combinator that is internally used is called K_record.
  3487 INCOMPATIBILITY: Usage of the plain update functions has to be
  3488 adapted.
  3489  
  3490 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3491 * x = 0, which are required for a semiring.  Richer structures do not
  3492 inherit from semiring_0 anymore, because this property is a theorem
  3493 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3494 there is more to prove, but this is mostly trivial.
  3495 
  3496 * Class "recpower" is generalized to arbitrary monoids, not just
  3497 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3498 commutativity or semiring properties additionally.
  3499 
  3500 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3501 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3502 better use 'abbreviation'.
  3503 
  3504 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3505 
  3506 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3507 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3508 significant changes for setting up numeral syntax for types:
  3509   - New constants Numeral.pred and Numeral.succ instead
  3510       of former Numeral.bin_pred and Numeral.bin_succ.
  3511   - Use integer operations instead of bin_add, bin_mult and so on.
  3512   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3513   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3514 
  3515 See src/HOL/Integ/IntArith.thy for an example setup.
  3516 
  3517 * Command 'normal_form' computes the normal form of a term that may
  3518 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3519 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3520 heavy-duty computations because the functions are compiled to ML
  3521 first.  Correspondingly, a method "normalization" is provided.  See
  3522 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3523 
  3524 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3525 25 like -->); output depends on the "iff" print_mode, the default is
  3526 "A = B" (with priority 50).
  3527 
  3528 * Relations less (<) and less_eq (<=) are also available on type bool.
  3529 Modified syntax to disallow nesting without explicit parentheses,
  3530 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3531 INCOMPATIBILITY.
  3532 
  3533 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3534 
  3535 * Relation composition operator "op O" now has precedence 75 and binds
  3536 stronger than union and intersection. INCOMPATIBILITY.
  3537 
  3538 * The old set interval syntax "{m..n(}" (and relatives) has been
  3539 removed.  Use "{m..<n}" (and relatives) instead.
  3540 
  3541 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3542 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3543 ``declare [[simproc del: neq]]''.
  3544 
  3545 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3546 True/False.
  3547 
  3548 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3549 
  3550 * Theorem setsum_mult renamed to setsum_right_distrib.
  3551 
  3552 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3553 ``rule'' method.
  3554 
  3555 * Reimplemented methods "sat" and "satx", with several improvements:
  3556 goals no longer need to be stated as "<prems> ==> False", equivalences
  3557 (i.e. "=" on type bool) are handled, variable names of the form
  3558 "lit_<n>" are no longer reserved, significant speedup.
  3559 
  3560 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3561 zChaff is still supported as well.
  3562 
  3563 * 'inductive' and 'datatype': provide projections of mutual rules,
  3564 bundled as foo_bar.inducts;
  3565 
  3566 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3567 Library.
  3568 
  3569 * Library: moved theory Accessible_Part to main HOL.
  3570 
  3571 * Library: added theory Coinductive_List of potentially infinite lists
  3572 as greatest fixed-point.
  3573 
  3574 * Library: added theory AssocList which implements (finite) maps as
  3575 association lists.
  3576 
  3577 * Method "evaluation" solves goals (i.e. a boolean expression)
  3578 efficiently by compiling it to ML.  The goal is "proved" (via an
  3579 oracle) if it evaluates to True.
  3580 
  3581 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3582 also when invoked by the simplifier.  This results in the Simplifier
  3583 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3584 Configuration option fast_arith_split_limit=0 recovers the old
  3585 behavior.
  3586 
  3587 * Support for hex (0x20) and binary (0b1001) numerals.
  3588 
  3589 * New method: reify eqs (t), where eqs are equations for an
  3590 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3591 parameter, computes a term s::'b and a list xs::'a list and proves the
  3592 theorem I xs s = t. This is also known as reification or quoting. The
  3593 resulting theorem is applied to the subgoal to substitute t with I xs
  3594 s.  If t is omitted, the subgoal itself is reified.
  3595 
  3596 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3597 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3598 where f is supposed to be a computable function (in the sense of code
  3599 generattion). The method uses reify to compute s and xs as above then
  3600 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3601 r and finally gets the theorem t = r, which is again applied to the
  3602 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3603 
  3604 * Reflection: Automatic reification now handels binding, an example is
  3605 available in src/HOL/ex/ReflectionEx.thy
  3606 
  3607 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3608 command 'statespace' that is similar to 'record', but introduces an
  3609 abstract specification based on the locale infrastructure instead of
  3610 HOL types.  This leads to extra flexibility in composing state spaces,
  3611 in particular multiple inheritance and renaming of components.
  3612 
  3613 
  3614 *** HOL-Complex ***
  3615 
  3616 * Hyperreal: Functions root and sqrt are now defined on negative real
  3617 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3618 Nonnegativity side conditions have been removed from many lemmas, so
  3619 that more subgoals may now be solved by simplification; potential
  3620 INCOMPATIBILITY.
  3621 
  3622 * Real: new type classes formalize real normed vector spaces and
  3623 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3624 and norm :: 'a => real.
  3625 
  3626 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3627 reals into other types. The overloaded constant Reals :: 'a set is now
  3628 defined as range of_real; potential INCOMPATIBILITY.
  3629 
  3630 * Real: proper support for ML code generation, including 'quickcheck'.
  3631 Reals are implemented as arbitrary precision rationals.
  3632 
  3633 * Hyperreal: Several constants that previously worked only for the
  3634 reals have been generalized, so they now work over arbitrary vector
  3635 spaces. Type annotations may need to be added in some cases; potential
  3636 INCOMPATIBILITY.
  3637 
  3638   Infinitesimal  :: ('a::real_normed_vector) star set
  3639   HFinite        :: ('a::real_normed_vector) star set
  3640   HInfinite      :: ('a::real_normed_vector) star set
  3641   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3642   monad          :: ('a::real_normed_vector) star => 'a star set
  3643   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3644   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3645   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3646   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3647   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3648   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3649   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3650   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3651   sgn            :: 'a::real_normed_vector => 'a
  3652   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3653 
  3654 * Complex: Some complex-specific constants are now abbreviations for
  3655 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3656 hnorm.  Other constants have been entirely removed in favor of the
  3657 polymorphic versions (INCOMPATIBILITY):
  3658 
  3659   approx        <-- capprox
  3660   HFinite       <-- CFinite
  3661   HInfinite     <-- CInfinite
  3662   Infinitesimal <-- CInfinitesimal
  3663   monad         <-- cmonad
  3664   galaxy        <-- cgalaxy
  3665   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3666   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3667   (ns)deriv     <-- (ns)cderiv
  3668 
  3669 
  3670 *** HOL-Algebra ***
  3671 
  3672 * Formalisation of ideals and the quotient construction over rings.
  3673 
  3674 * Order and lattice theory no longer based on records.
  3675 INCOMPATIBILITY.
  3676 
  3677 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3678 greatest_closed.  INCOMPATIBILITY.
  3679 
  3680 * Method algebra is now set up via an attribute.  For examples see
  3681 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3682 of algebraic structures.
  3683 
  3684 * Renamed theory CRing to Ring.
  3685 
  3686 
  3687 *** HOL-Nominal ***
  3688 
  3689 * Substantial, yet incomplete support for nominal datatypes (binding
  3690 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3691 src/HOL/Nominal/Examples.  Prospective users should consult
  3692 http://isabelle.in.tum.de/nominal/
  3693 
  3694 
  3695 *** ML ***
  3696 
  3697 * ML basics: just one true type int, which coincides with IntInf.int
  3698 (even on SML/NJ).
  3699 
  3700 * ML within Isar: antiquotations allow to embed statically-checked
  3701 formal entities in the source, referring to the context available at
  3702 compile-time.  For example:
  3703 
  3704 ML {* @{sort "{zero,one}"} *}
  3705 ML {* @{typ "'a => 'b"} *}
  3706 ML {* @{term "%x. x"} *}
  3707 ML {* @{prop "x == y"} *}
  3708 ML {* @{ctyp "'a => 'b"} *}
  3709 ML {* @{cterm "%x. x"} *}
  3710 ML {* @{cprop "x == y"} *}
  3711 ML {* @{thm asm_rl} *}
  3712 ML {* @{thms asm_rl} *}
  3713 ML {* @{type_name c} *}
  3714 ML {* @{type_syntax c} *}
  3715 ML {* @{const_name c} *}
  3716 ML {* @{const_syntax c} *}
  3717 ML {* @{context} *}
  3718 ML {* @{theory} *}
  3719 ML {* @{theory Pure} *}
  3720 ML {* @{theory_ref} *}
  3721 ML {* @{theory_ref Pure} *}
  3722 ML {* @{simpset} *}
  3723 ML {* @{claset} *}
  3724 ML {* @{clasimpset} *}
  3725 
  3726 The same works for sources being ``used'' within an Isar context.
  3727 
  3728 * ML in Isar: improved error reporting; extra verbosity with
  3729 ML_Context.trace enabled.
  3730 
  3731 * Pure/General/table.ML: the join operations now works via exceptions
  3732 DUP/SAME instead of type option. This is simpler in simple cases, and
  3733 admits slightly more efficient complex applications.
  3734 
  3735 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3736 use Context.generic instead of just theory.
  3737 
  3738 * Pure: datatype Context.generic joins theory/Proof.context and
  3739 provides some facilities for code that works in either kind of
  3740 context, notably GenericDataFun for uniform theory and proof data.
  3741 
  3742 * Pure: simplified internal attribute type, which is now always
  3743 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3744 local (Proof.context) attributes have been discontinued, while
  3745 minimizing code duplication. Thm.rule_attribute and
  3746 Thm.declaration_attribute build canonical attributes; see also structure
  3747 Context for further operations on Context.generic, notably
  3748 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3749 declarations and definitions.
  3750 
  3751 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3752 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3753 init only required for impure data. INCOMPATIBILITY: empty really need
  3754 to be empty (no dependencies on theory content!)
  3755 
  3756 * Pure/kernel: consts certification ignores sort constraints given in
  3757 signature declarations. (This information is not relevant to the
  3758 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3759 potential INCOMPATIBILITY.
  3760 
  3761 * Pure: axiomatic type classes are now purely definitional, with
  3762 explicit proofs of class axioms and super class relations performed
  3763 internally. See Pure/axclass.ML for the main internal interfaces --
  3764 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3765 AxClass.axiomatize_class/classrel/arity supersede
  3766 Sign.add_classes/classrel/arities.
  3767 
  3768 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3769 global/local versions on theory vs. Proof.context have been
  3770 discontinued; Attrib.syntax and Method.syntax have been adapted
  3771 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3772 attributes, methods, etc.
  3773 
  3774 * Pure: several functions of signature "... -> theory -> theory * ..."
  3775 have been reoriented to "... -> theory -> ... * theory" in order to
  3776 allow natural usage in combination with the ||>, ||>>, |-> and
  3777 fold_map combinators.
  3778 
  3779 * Pure: official theorem names (closed derivations) and additional
  3780 comments (tags) are now strictly separate.  Name hints -- which are
  3781 maintained as tags -- may be attached any time without affecting the
  3782 derivation.
  3783 
  3784 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3785 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3786 achieve the old behaviour.
  3787 
  3788 * Pure: the "Goal" constant is now called "prop", supporting a
  3789 slightly more general idea of ``protecting'' meta-level rule
  3790 statements.
  3791 
  3792 * Pure: Logic.(un)varify only works in a global context, which is now
  3793 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3794 Logic.legacy_(un)varify as temporary workaround.
  3795 
  3796 * Pure: structure Name provides scalable operations for generating
  3797 internal variable names, notably Name.variants etc.  This replaces
  3798 some popular functions from term.ML:
  3799 
  3800   Term.variant		->  Name.variant
  3801   Term.variantlist	->  Name.variant_list
  3802   Term.invent_names	->  Name.invent_list
  3803 
  3804 Note that low-level renaming rarely occurs in new code -- operations
  3805 from structure Variable are used instead (see below).
  3806 
  3807 * Pure: structure Variable provides fundamental operations for proper
  3808 treatment of fixed/schematic variables in a context.  For example,
  3809 Variable.import introduces fixes for schematics of given facts and
  3810 Variable.export reverses the effect (up to renaming) -- this replaces
  3811 various freeze_thaw operations.
  3812 
  3813 * Pure: structure Goal provides simple interfaces for
  3814 init/conclude/finish and tactical prove operations (replacing former
  3815 Tactic.prove).  Goal.prove is the canonical way to prove results
  3816 within a given context; Goal.prove_global is a degraded version for
  3817 theory level goals, including a global Drule.standard.  Note that
  3818 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3819 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3820 in a locale context).
  3821 
  3822 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3823 and type checking (Syntax.check_term etc.), with common combinations
  3824 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3825 which are considered legacy and await removal.
  3826 
  3827 * Pure/Syntax: generic interfaces for type unchecking
  3828 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3829 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3830 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3831 available for convenience, but refer to the very same operations using
  3832 a mere theory instead of a full context.
  3833 
  3834 * Isar: simplified treatment of user-level errors, using exception
  3835 ERROR of string uniformly.  Function error now merely raises ERROR,
  3836 without any side effect on output channels.  The Isar toplevel takes
  3837 care of proper display of ERROR exceptions.  ML code may use plain
  3838 handle/can/try; cat_error may be used to concatenate errors like this:
  3839 
  3840   ... handle ERROR msg => cat_error msg "..."
  3841 
  3842 Toplevel ML code (run directly or through the Isar toplevel) may be
  3843 embedded into the Isar toplevel with exception display/debug like
  3844 this:
  3845 
  3846   Isar.toplevel (fn () => ...)
  3847 
  3848 INCOMPATIBILITY, removed special transform_error facilities, removed
  3849 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3850 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3851 -- use plain ERROR instead.
  3852 
  3853 * Isar: theory setup now has type (theory -> theory), instead of a
  3854 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3855 
  3856 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3857 ProofContext.debug/verbose flags.
  3858 
  3859 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3860 theory before entering a proof state.  Transactions now always see a
  3861 quasi-functional intermediate checkpoint, both in interactive and
  3862 batch mode.
  3863 
  3864 * Isar: simplified interfaces for outer syntax.  Renamed
  3865 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3866 OuterSyntax.add_parsers -- this functionality is now included in
  3867 OuterSyntax.command etc.  INCOMPATIBILITY.
  3868 
  3869 * Simplifier: the simpset of a running simplification process now
  3870 contains a proof context (cf. Simplifier.the_context), which is the
  3871 very context that the initial simpset has been retrieved from (by
  3872 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3873 (solver, looper etc.) may depend on arbitrary proof data.
  3874 
  3875 * Simplifier.inherit_context inherits the proof context (plus the
  3876 local bounds) of the current simplification process; any simproc
  3877 etc. that calls the Simplifier recursively should do this!  Removed
  3878 former Simplifier.inherit_bounds, which is already included here --
  3879 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3880 specify an explicit context using Simplifier.context/theory_context.
  3881 
  3882 * Simplifier/Classical Reasoner: more abstract interfaces
  3883 change_simpset/claset for modifying the simpset/claset reference of a
  3884 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3885 INCOMPATIBILITY.
  3886 
  3887 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3888 "Trueprop" etc.
  3889 
  3890 
  3891 *** System ***
  3892 
  3893 * settings: the default heap location within ISABELLE_HOME_USER now
  3894 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3895 Isabelle installations.
  3896 
  3897 * isabelle-process: option -S (secure mode) disables some critical
  3898 operations, notably runtime compilation and evaluation of ML source
  3899 code.
  3900 
  3901 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3902 
  3903 * Support for parallel execution, using native multicore support of
  3904 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3905 independent theories, according to the given theory header
  3906 specifications. The maximum number of worker threads is specified via
  3907 usedir option -M or the "max-threads" setting in Proof General. A
  3908 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3909 to 6 on a 8-core machine.  User-code needs to observe certain
  3910 guidelines for thread-safe programming, see appendix A in the Isar
  3911 Implementation manual.
  3912 
  3913 
  3914 
  3915 New in Isabelle2005 (October 2005)
  3916 ----------------------------------
  3917 
  3918 *** General ***
  3919 
  3920 * Theory headers: the new header syntax for Isar theories is
  3921 
  3922   theory <name>
  3923   imports <theory1> ... <theoryN>
  3924   uses <file1> ... <fileM>
  3925   begin
  3926 
  3927 where the 'uses' part is optional.  The previous syntax
  3928 
  3929   theory <name> = <theory1> + ... + <theoryN>:
  3930 
  3931 will disappear in the next release.  Use isatool fixheaders to convert
  3932 existing theory files.  Note that there is no change in ancient
  3933 non-Isar theories now, but these will disappear soon.
  3934 
  3935 * Theory loader: parent theories can now also be referred to via
  3936 relative and absolute paths.
  3937 
  3938 * Command 'find_theorems' searches for a list of criteria instead of a
  3939 list of constants. Known criteria are: intro, elim, dest, name:string,
  3940 simp:term, and any term. Criteria can be preceded by '-' to select
  3941 theorems that do not match. Intro, elim, dest select theorems that
  3942 match the current goal, name:s selects theorems whose fully qualified
  3943 name contain s, and simp:term selects all simplification rules whose
  3944 lhs match term.  Any other term is interpreted as pattern and selects
  3945 all theorems matching the pattern. Available in ProofGeneral under
  3946 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3947 
  3948   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3949 
  3950 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3951 matching the current goal as introduction rule and not having "HOL."
  3952 in their name (i.e. not being defined in theory HOL).
  3953 
  3954 * Command 'thms_containing' has been discontinued in favour of
  3955 'find_theorems'; INCOMPATIBILITY.
  3956 
  3957 * Communication with Proof General is now 8bit clean, which means that
  3958 Unicode text in UTF-8 encoding may be used within theory texts (both
  3959 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3960 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3961 
  3962   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3963   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3964 
  3965 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3966 Classical Reasoner.  Typical big applications run around 2 times
  3967 faster.
  3968 
  3969 
  3970 *** Document preparation ***
  3971 
  3972 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3973 of raw sources.  Only those symbols that do not require additional
  3974 LaTeX packages (depending on comments in isabellesym.sty) are
  3975 displayed properly, everything else is left verbatim.  isatool display
  3976 and isatool print are used as front ends (these are subject to the
  3977 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3978 
  3979 * Command tags control specific markup of certain regions of text,
  3980 notably folding and hiding.  Predefined tags include "theory" (for
  3981 theory begin and end), "proof" for proof commands, and "ML" for
  3982 commands involving ML code; the additional tags "visible" and
  3983 "invisible" are unused by default.  Users may give explicit tag
  3984 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3985 interpretation of tags is determined by the LaTeX job during document
  3986 preparation: see option -V of isatool usedir, or options -n and -t of
  3987 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3988 \isadroptag.
  3989 
  3990 Several document versions may be produced at the same time via isatool
  3991 usedir (the generated index.html will link all of them).  Typical
  3992 specifications include ''-V document=theory,proof,ML'' to present
  3993 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3994 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3995 these parts without any formal replacement text.  The Isabelle site
  3996 default settings produce ''document'' and ''outline'' versions as
  3997 specified above.
  3998 
  3999 * Several new antiquotations:
  4000 
  4001   @{term_type term} prints a term with its type annotated;
  4002 
  4003   @{typeof term} prints the type of a term;
  4004 
  4005   @{const const} is the same as @{term const}, but checks that the
  4006   argument is a known logical constant;
  4007 
  4008   @{term_style style term} and @{thm_style style thm} print a term or
  4009   theorem applying a "style" to it
  4010 
  4011   @{ML text}
  4012 
  4013 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4014 definitions, equations, inequations etc., 'concl' printing only the
  4015 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4016 to print the specified premise.  TermStyle.add_style provides an ML
  4017 interface for introducing further styles.  See also the "LaTeX Sugar"
  4018 document practical applications.  The ML antiquotation prints
  4019 type-checked ML expressions verbatim.
  4020 
  4021 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4022 and 'text' support optional locale specification '(in loc)', which
  4023 specifies the default context for interpreting antiquotations.  For
  4024 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4025 
  4026 * Option 'locale=NAME' of antiquotations specifies an alternative
  4027 context interpreting the subsequent argument.  For example: @{thm
  4028 [locale=lattice] inf_assoc}.
  4029 
  4030 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4031 a proof context.
  4032 
  4033 * Proper output of antiquotations for theory commands involving a
  4034 proof context (such as 'locale' or 'theorem (in loc) ...').
  4035 
  4036 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4037 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4038 
  4039 * isatool usedir: new option -C (default true) controls whether option
  4040 -D should include a copy of the original document directory; -C false
  4041 prevents unwanted effects such as copying of administrative CVS data.
  4042 
  4043 
  4044 *** Pure ***
  4045 
  4046 * Considerably improved version of 'constdefs' command.  Now performs
  4047 automatic type-inference of declared constants; additional support for
  4048 local structure declarations (cf. locales and HOL records), see also
  4049 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4050 sequential dependencies of definitions within a single 'constdefs'
  4051 section; moreover, the declared name needs to be an identifier.  If
  4052 all fails, consider to fall back on 'consts' and 'defs' separately.
  4053 
  4054 * Improved indexed syntax and implicit structures.  First of all,
  4055 indexed syntax provides a notational device for subscripted
  4056 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4057 expressions.  Secondly, in a local context with structure
  4058 declarations, number indexes \<^sub>n or the empty index (default
  4059 number 1) refer to a certain fixed variable implicitly; option
  4060 show_structs controls printing of implicit structures.  Typical
  4061 applications of these concepts involve record types and locales.
  4062 
  4063 * New command 'no_syntax' removes grammar declarations (and
  4064 translations) resulting from the given syntax specification, which is
  4065 interpreted in the same manner as for the 'syntax' command.
  4066 
  4067 * 'Advanced' translation functions (parse_translation etc.) may depend
  4068 on the signature of the theory context being presently used for
  4069 parsing/printing, see also isar-ref manual.
  4070 
  4071 * Improved 'oracle' command provides a type-safe interface to turn an
  4072 ML expression of type theory -> T -> term into a primitive rule of
  4073 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4074 is already included here); see also FOL/ex/IffExample.thy;
  4075 INCOMPATIBILITY.
  4076 
  4077 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4078 before); "cI" is no longer bound, use "c.intro" instead.
  4079 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4080 axclasses vs. locales.
  4081 
  4082 * Improved internal renaming of symbolic identifiers -- attach primes
  4083 instead of base 26 numbers.
  4084 
  4085 * New flag show_question_marks controls printing of leading question
  4086 marks in schematic variable names.
  4087 
  4088 * In schematic variable names, *any* symbol following \<^isub> or
  4089 \<^isup> is now treated as part of the base name.  For example, the
  4090 following works without printing of awkward ".0" indexes:
  4091 
  4092   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4093     by simp
  4094 
  4095 * Inner syntax includes (*(*nested*) comments*).
  4096 
  4097 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4098 annotations as "(00...)".
  4099 
  4100 * Clear separation of logical types and nonterminals, where the latter
  4101 may only occur in 'syntax' specifications or type abbreviations.
  4102 Before that distinction was only partially implemented via type class
  4103 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4104 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4105 exotic syntax specifications may require further adaption
  4106 (e.g. Cube/Cube.thy).
  4107 
  4108 * Removed obsolete type class "logic", use the top sort {} instead.
  4109 Note that non-logical types should be declared as 'nonterminals'
  4110 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4111 specifications.
  4112 
  4113 * Attributes 'induct' and 'cases': type or set names may now be
  4114 locally fixed variables as well.
  4115 
  4116 * Simplifier: can now control the depth to which conditional rewriting
  4117 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4118 Limit.
  4119 
  4120 * Simplifier: simplification procedures may now take the current
  4121 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4122 interface), which is very useful for calling the Simplifier
  4123 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4124 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4125 low-level mk_simproc no longer applies Logic.varify internally, to
  4126 allow for use in a context of fixed variables.
  4127 
  4128 * thin_tac now works even if the assumption being deleted contains !!
  4129 or ==>.  More generally, erule now works even if the major premise of
  4130 the elimination rule contains !! or ==>.
  4131 
  4132 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4133 
  4134 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4135 from Pure, which contains all common declarations already.  Both
  4136 theories are defined via plain Isabelle/Isar .thy files.
  4137 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4138 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4139 use isatool fixcpure to adapt your theory and ML sources.
  4140 
  4141 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4142 selections of theorems in named facts via index ranges.
  4143 
  4144 * 'print_theorems': in theory mode, really print the difference
  4145 wrt. the last state (works for interactive theory development only),
  4146 in proof mode print all local facts (cf. 'print_facts');
  4147 
  4148 * 'hide': option '(open)' hides only base names.
  4149 
  4150 * More efficient treatment of intermediate checkpoints in interactive
  4151 theory development.
  4152 
  4153 * Code generator is now invoked via code_module (incremental code
  4154 generation) and code_library (modular code generation, ML structures
  4155 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4156 must be quoted when used as identifiers.
  4157 
  4158 * New 'value' command for reading, evaluating and printing terms using
  4159 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4160 quoted when used as identifier.
  4161 
  4162 
  4163 *** Locales ***
  4164 
  4165 * New commands for the interpretation of locale expressions in
  4166 theories (1), locales (2) and proof contexts (3).  These generate
  4167 proof obligations from the expression specification.  After the
  4168 obligations have been discharged, theorems of the expression are added
  4169 to the theory, target locale or proof context.  The synopsis of the
  4170 commands is a follows:
  4171 
  4172   (1) interpretation expr inst
  4173   (2) interpretation target < expr
  4174   (3) interpret expr inst
  4175 
  4176 Interpretation in theories and proof contexts require a parameter
  4177 instantiation of terms from the current context.  This is applied to
  4178 specifications and theorems of the interpreted expression.
  4179 Interpretation in locales only permits parameter renaming through the
  4180 locale expression.  Interpretation is smart in that interpretations
  4181 that are active already do not occur in proof obligations, neither are
  4182 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4183 inspect active interpretations of a particular locale.  For details,
  4184 see the Isar Reference manual.  Examples can be found in
  4185 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4186 
  4187 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4188 'interpret' instead.
  4189 
  4190 * New context element 'constrains' for adding type constraints to
  4191 parameters.
  4192 
  4193 * Context expressions: renaming of parameters with syntax
  4194 redeclaration.
  4195 
  4196 * Locale declaration: 'includes' disallowed.
  4197 
  4198 * Proper static binding of attribute syntax -- i.e. types / terms /
  4199 facts mentioned as arguments are always those of the locale definition
  4200 context, independently of the context of later invocations.  Moreover,
  4201 locale operations (renaming and type / term instantiation) are applied
  4202 to attribute arguments as expected.
  4203 
  4204 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4205 actual attributes; rare situations may require Attrib.attribute to
  4206 embed those attributes into Attrib.src that lack concrete syntax.
  4207 Attribute implementations need to cooperate properly with the static
  4208 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4209 Attrib.XXX_thm etc. already do the right thing without further
  4210 intervention.  Only unusual applications -- such as "where" or "of"
  4211 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4212 on the context and the facts involved -- may have to assign parsed
  4213 values to argument tokens explicitly.
  4214 
  4215 * Changed parameter management in theorem generation for long goal
  4216 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4217 theorem statement in rare situations.
  4218 
  4219 * Locale inspection command 'print_locale' omits notes elements.  Use
  4220 'print_locale!' to have them included in the output.
  4221 
  4222 
  4223 *** Provers ***
  4224 
  4225 * Provers/hypsubst.ML: improved version of the subst method, for
  4226 single-step rewriting: it now works in bound variable contexts. New is
  4227 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4228 rewrite a different subterm than the original subst method, which is
  4229 still available as 'simplesubst'.
  4230 
  4231 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4232 and quasi orders.
  4233 
  4234 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4235 reflexive-transitive closure of relations.
  4236 
  4237 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4238 limit (previously hard-coded with a value of 20) user-definable.
  4239 
  4240 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4241 is peformed already.  Object-logics merely need to finish their
  4242 initial simpset configuration as before.  INCOMPATIBILITY.
  4243 
  4244 
  4245 *** HOL ***
  4246 
  4247 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4248 
  4249   syntax (epsilon)
  4250     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4251 
  4252 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4253 and x-symbol; use option '-m epsilon' to get it actually printed.
  4254 Moreover, the mathematically important symbolic identifier \<epsilon>
  4255 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4256 
  4257 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4258 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4259 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4260 support corresponding Isar calculations.
  4261 
  4262 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4263 instead of ":".
  4264 
  4265 * theory SetInterval: changed the syntax for open intervals:
  4266 
  4267   Old       New
  4268   {..n(}    {..<n}
  4269   {)n..}    {n<..}
  4270   {m..n(}   {m..<n}
  4271   {)m..n}   {m<..n}
  4272   {)m..n(}  {m<..<n}
  4273 
  4274 The old syntax is still supported but will disappear in the next
  4275 release.  For conversion use the following Emacs search and replace
  4276 patterns (these are not perfect but work quite well):
  4277 
  4278   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4279   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4280 
  4281 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4282 equalities in commutative rings; method 'algebra' provides a generic
  4283 interface.
  4284 
  4285 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4286 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4287 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4288 be a tuple pattern.
  4289 
  4290 Some new syntax forms are available:
  4291 
  4292   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4293   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4294   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4295   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4296 
  4297 The latter form "\<Sum>x < k. e" used to be based on a separate
  4298 function "Summation", which has been discontinued.
  4299 
  4300 * theory Finite_Set: in structured induction proofs, the insert case
  4301 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4302 (insert F x)'.
  4303 
  4304 * The 'refute' command has been extended to support a much larger
  4305 fragment of HOL, including axiomatic type classes, constdefs and
  4306 typedefs, inductive datatypes and recursion.
  4307 
  4308 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4309 Requires zChaff with proof generation to be installed.  See
  4310 HOL/ex/SAT_Examples.thy for examples.
  4311 
  4312 * Datatype induction via method 'induct' now preserves the name of the
  4313 induction variable. For example, when proving P(xs::'a list) by
  4314 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4315 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4316 in unstructured proof scripts.
  4317 
  4318 * Reworked implementation of records.  Improved scalability for
  4319 records with many fields, avoiding performance problems for type
  4320 inference. Records are no longer composed of nested field types, but
  4321 of nested extension types. Therefore the record type only grows linear
  4322 in the number of extensions and not in the number of fields.  The
  4323 top-level (users) view on records is preserved.  Potential
  4324 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4325 old record representation. The type generated for a record is called
  4326 <record_name>_ext_type.
  4327 
  4328 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4329 proofs triggered by a record definition or a simproc (if
  4330 quick_and_dirty is enabled).  Definitions of large records can take
  4331 quite long.
  4332 
  4333 New simproc record_upd_simproc for simplification of multiple record
  4334 updates enabled by default.  Moreover, trivial updates are also
  4335 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4336 occasionally, since simplification is more powerful by default.
  4337 
  4338 * typedef: proper support for polymorphic sets, which contain extra
  4339 type-variables in the term.
  4340 
  4341 * Simplifier: automatically reasons about transitivity chains
  4342 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4343 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4344 old proofs break occasionally as simplification may now solve more
  4345 goals than previously.
  4346 
  4347 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4348 present.  Works for all partial orders (class "order"), in particular
  4349 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4350 just like y <= x.
  4351 
  4352 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4353 bound variable or a constant then the let is unfolded.  Otherwise
  4354 first a is simplified to b, and then f b is simplified to g. If
  4355 possible we abstract b from g arriving at "let x = b in h x",
  4356 otherwise we unfold the let and arrive at g.  The simproc can be
  4357 enabled/disabled by the reference use_let_simproc.  Potential
  4358 INCOMPATIBILITY since simplification is more powerful by default.
  4359 
  4360 * Classical reasoning: the meson method now accepts theorems as arguments.
  4361 
  4362 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4363 jobs to provide advice on the provability of subgoals.
  4364 
  4365 * Theory OrderedGroup and Ring_and_Field: various additions and
  4366 improvements to faciliate calculations involving equalities and
  4367 inequalities.
  4368 
  4369 The following theorems have been eliminated or modified
  4370 (INCOMPATIBILITY):
  4371 
  4372   abs_eq             now named abs_of_nonneg
  4373   abs_of_ge_0        now named abs_of_nonneg
  4374   abs_minus_eq       now named abs_of_nonpos
  4375   imp_abs_id         now named abs_of_nonneg
  4376   imp_abs_neg_id     now named abs_of_nonpos
  4377   mult_pos           now named mult_pos_pos
  4378   mult_pos_le        now named mult_nonneg_nonneg
  4379   mult_pos_neg_le    now named mult_nonneg_nonpos
  4380   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4381   mult_neg           now named mult_neg_neg
  4382   mult_neg_le        now named mult_nonpos_nonpos
  4383 
  4384 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4385      
  4386      zero_le_square
  4387      not_square_less_zero 
  4388 
  4389   The following lemmas have been deleted from Real/RealPow:
  4390   
  4391      realpow_zero_zero
  4392      realpow_two
  4393      realpow_less
  4394      zero_le_power
  4395      realpow_two_le
  4396      abs_realpow_two
  4397      realpow_two_abs     
  4398 
  4399 * Theory Parity: added rules for simplifying exponents.
  4400 
  4401 * Theory List:
  4402 
  4403 The following theorems have been eliminated or modified
  4404 (INCOMPATIBILITY):
  4405 
  4406   list_all_Nil       now named list_all.simps(1)
  4407   list_all_Cons      now named list_all.simps(2)
  4408   list_all_conv      now named list_all_iff
  4409   set_mem_eq         now named mem_iff
  4410 
  4411 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4412 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4413 
  4414 
  4415 *** HOL-Complex ***
  4416 
  4417 * Theory RealDef: better support for embedding natural numbers and
  4418 integers in the reals.
  4419 
  4420 The following theorems have been eliminated or modified
  4421 (INCOMPATIBILITY):
  4422 
  4423   exp_ge_add_one_self  now requires no hypotheses
  4424   real_of_int_add      reversed direction of equality (use [symmetric])
  4425   real_of_int_minus    reversed direction of equality (use [symmetric])
  4426   real_of_int_diff     reversed direction of equality (use [symmetric])
  4427   real_of_int_mult     reversed direction of equality (use [symmetric])
  4428 
  4429 * Theory RComplete: expanded support for floor and ceiling functions.
  4430 
  4431 * Theory Ln is new, with properties of the natural logarithm
  4432 
  4433 * Hyperreal: There is a new type constructor "star" for making
  4434 nonstandard types.  The old type names are now type synonyms:
  4435 
  4436   hypreal = real star
  4437   hypnat = nat star
  4438   hcomplex = complex star
  4439 
  4440 * Hyperreal: Many groups of similarly-defined constants have been
  4441 replaced by polymorphic versions (INCOMPATIBILITY):
  4442 
  4443   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4444 
  4445   starset      <-- starsetNat, starsetC
  4446   *s*          <-- *sNat*, *sc*
  4447   starset_n    <-- starsetNat_n, starsetC_n
  4448   *sn*         <-- *sNatn*, *scn*
  4449   InternalSets <-- InternalNatSets, InternalCSets
  4450 
  4451   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4452   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4453   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4454   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4455   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4456 
  4457 * Hyperreal: Many type-specific theorems have been removed in favor of
  4458 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4459 
  4460   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4461   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4462   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4463   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4464   right_minus <-- hypreal_add_minus
  4465   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4466   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4467   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4468   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4469   mult_1_right <-- hcomplex_mult_one_right
  4470   mult_zero_left <-- hcomplex_mult_zero_left
  4471   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4472   right_distrib <-- hypnat_add_mult_distrib2
  4473   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4474   right_inverse <-- hypreal_mult_inverse
  4475   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4476   order_refl <-- {hypreal,hypnat}_le_refl
  4477   order_trans <-- {hypreal,hypnat}_le_trans
  4478   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4479   order_less_le <-- {hypreal,hypnat}_less_le
  4480   linorder_linear <-- {hypreal,hypnat}_le_linear
  4481   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4482   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4483   add_nonneg_nonneg <-- hypreal_le_add_order
  4484 
  4485 * Hyperreal: Separate theorems having to do with type-specific
  4486 versions of constants have been merged into theorems that apply to the
  4487 new polymorphic constants (INCOMPATIBILITY):
  4488 
  4489   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4490   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4491   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4492   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4493   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4494   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4495   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4496   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4497   STAR_diff <-- {STAR,STARC}_diff
  4498   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4499     STARC_hcomplex_of_complex}_image_subset
  4500   starset_n_Un <-- starset{Nat,C}_n_Un
  4501   starset_n_Int <-- starset{Nat,C}_n_Int
  4502   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4503   starset_n_diff <-- starset{Nat,C}_n_diff
  4504   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4505   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4506   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4507   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4508   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4509   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4510   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4511   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4512   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4513   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4514   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4515   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4516   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4517   starfun_diff <-- starfun{C,RC,CR}_diff
  4518   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4519   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4520   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4521   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4522   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4523   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4524   starfun_Id <-- starfunC_Id
  4525   starfun_approx <-- starfun{Nat,CR}_approx
  4526   starfun_capprox <-- starfun{C,RC}_capprox
  4527   starfun_abs <-- starfunNat_rabs
  4528   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4529   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4530   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4531   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4532   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4533   starfun_add_approx <-- starfunCR_add_approx
  4534   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4535   starfun_divide <-- starfun{C,CR,RC}_divide
  4536   starfun_n <-- starfun{Nat,C}_n
  4537   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4538   starfun_n_add <-- starfun{Nat,C}_n_add
  4539   starfun_n_add_minus <-- starfunNat_n_add_minus
  4540   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4541   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4542   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4543 
  4544   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4545   star_n_minus <-- {hypreal,hcomplex}_minus
  4546   star_n_diff <-- {hypreal,hcomplex}_diff
  4547   star_n_mult <-- {hypreal,hcomplex}_mult
  4548   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4549   star_n_le <-- {hypreal,hypnat}_le
  4550   star_n_less <-- {hypreal,hypnat}_less
  4551   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4552   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4553   star_n_abs <-- hypreal_hrabs
  4554   star_n_divide <-- hcomplex_divide
  4555 
  4556   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4557   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4558   star_of_diff <-- hypreal_of_real_diff
  4559   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4560   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4561   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4562   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4563   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4564   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4565   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4566   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4567   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4568   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4569   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4570   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4571   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4572   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4573   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4574   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4575   star_of_power <-- hypreal_of_real_power
  4576   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4577 
  4578 * Hyperreal: new method "transfer" that implements the transfer
  4579 principle of nonstandard analysis. With a subgoal that mentions
  4580 nonstandard types like "'a star", the command "apply transfer"
  4581 replaces it with an equivalent one that mentions only standard types.
  4582 To be successful, all free variables must have standard types; non-
  4583 standard variables must have explicit universal quantifiers.
  4584 
  4585 * Hyperreal: A theory of Taylor series.
  4586 
  4587 
  4588 *** HOLCF ***
  4589 
  4590 * Discontinued special version of 'constdefs' (which used to support
  4591 continuous functions) in favor of the general Pure one with full
  4592 type-inference.
  4593 
  4594 * New simplification procedure for solving continuity conditions; it
  4595 is much faster on terms with many nested lambda abstractions (cubic
  4596 instead of exponential time).
  4597 
  4598 * New syntax for domain package: selector names are now optional.
  4599 Parentheses should be omitted unless argument is lazy, for example:
  4600 
  4601   domain 'a stream = cons "'a" (lazy "'a stream")
  4602 
  4603 * New command 'fixrec' for defining recursive functions with pattern
  4604 matching; defining multiple functions with mutual recursion is also
  4605 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4606 sinr, or any data constructor defined by the domain package. The given
  4607 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4608 syntax and examples.
  4609 
  4610 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4611 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4612 but the proof obligation additionally includes an admissibility
  4613 requirement. The packages generate instances of class cpo or pcpo,
  4614 with continuity and strictness theorems for Rep and Abs.
  4615 
  4616 * HOLCF: Many theorems have been renamed according to a more standard naming
  4617 scheme (INCOMPATIBILITY):
  4618 
  4619   foo_inject:  "foo$x = foo$y ==> x = y"
  4620   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4621   foo_less:    "(foo$x << foo$y) = (x << y)"
  4622   foo_strict:  "foo$UU = UU"
  4623   foo_defined: "... ==> foo$x ~= UU"
  4624   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4625 
  4626 
  4627 *** ZF ***
  4628 
  4629 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4630 including the First Isomorphism Theorem (on quotienting by the kernel
  4631 of a homomorphism).
  4632 
  4633 * ZF/Simplifier: install second copy of type solver that actually
  4634 makes use of TC rules declared to Isar proof contexts (or locales);
  4635 the old version is still required for ML proof scripts.
  4636 
  4637 
  4638 *** Cube ***
  4639 
  4640 * Converted to Isar theory format; use locales instead of axiomatic
  4641 theories.
  4642 
  4643 
  4644 *** ML ***
  4645 
  4646 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4647 for ||>, ||>>, |>>,
  4648 
  4649 * Pure/library.ML no longer defines its own option datatype, but uses
  4650 that of the SML basis, which has constructors NONE and SOME instead of
  4651 None and Some, as well as exception Option.Option instead of OPTION.
  4652 The functions the, if_none, is_some, is_none have been adapted
  4653 accordingly, while Option.map replaces apsome.
  4654 
  4655 * Pure/library.ML: the exception LIST has been given up in favour of
  4656 the standard exceptions Empty and Subscript, as well as
  4657 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4658 superceded by the standard hd and tl functions etc.
  4659 
  4660 A number of basic list functions are no longer exported to the ML
  4661 toplevel, as they are variants of predefined functions.  The following
  4662 suggests how one can translate existing code:
  4663 
  4664     rev_append xs ys = List.revAppend (xs, ys)
  4665     nth_elem (i, xs) = List.nth (xs, i)
  4666     last_elem xs = List.last xs
  4667     flat xss = List.concat xss
  4668     seq fs = List.app fs
  4669     partition P xs = List.partition P xs
  4670     mapfilter f xs = List.mapPartial f xs
  4671 
  4672 * Pure/library.ML: several combinators for linear functional
  4673 transformations, notably reverse application and composition:
  4674 
  4675   x |> f                f #> g
  4676   (x, y) |-> f          f #-> g
  4677 
  4678 * Pure/library.ML: introduced/changed precedence of infix operators:
  4679 
  4680   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4681   infix 2 ?;
  4682   infix 3 o oo ooo oooo;
  4683   infix 4 ~~ upto downto;
  4684 
  4685 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4686 infix operators.
  4687 
  4688 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4689 fold_map support linear functional transformations and nesting.  For
  4690 example:
  4691 
  4692   fold f [x1, ..., xN] y =
  4693     y |> f x1 |> ... |> f xN
  4694 
  4695   (fold o fold) f [xs1, ..., xsN] y =
  4696     y |> fold f xs1 |> ... |> fold f xsN
  4697 
  4698   fold f [x1, ..., xN] =
  4699     f x1 #> ... #> f xN
  4700 
  4701   (fold o fold) f [xs1, ..., xsN] =
  4702     fold f xs1 #> ... #> fold f xsN
  4703 
  4704 * Pure/library.ML: the following selectors on type 'a option are
  4705 available:
  4706 
  4707   the:               'a option -> 'a  (*partial*)
  4708   these:             'a option -> 'a  where 'a = 'b list
  4709   the_default: 'a -> 'a option -> 'a
  4710   the_list:          'a option -> 'a list
  4711 
  4712 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4713 basic operations for association lists, following natural argument
  4714 order; moreover the explicit equality predicate passed here avoids
  4715 potentially expensive polymorphic runtime equality checks.
  4716 The old functions may be expressed as follows:
  4717 
  4718   assoc = uncurry (AList.lookup (op =))
  4719   assocs = these oo AList.lookup (op =)
  4720   overwrite = uncurry (AList.update (op =)) o swap
  4721 
  4722 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4723 
  4724   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4725   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4726 
  4727 replacing make_keylist and keyfilter (occassionally used)
  4728 Naive rewrites:
  4729 
  4730   make_keylist = AList.make
  4731   keyfilter = AList.find (op =)
  4732 
  4733 * eq_fst and eq_snd now take explicit equality parameter, thus
  4734   avoiding eqtypes. Naive rewrites:
  4735 
  4736     eq_fst = eq_fst (op =)
  4737     eq_snd = eq_snd (op =)
  4738 
  4739 * Removed deprecated apl and apr (rarely used).
  4740   Naive rewrites:
  4741 
  4742     apl (n, op) =>>= curry op n
  4743     apr (op, m) =>>= fn n => op (n, m)
  4744 
  4745 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4746 provides a reasonably efficient light-weight implementation of sets as
  4747 lists.
  4748 
  4749 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4750 few new operations; existing lookup and update are now curried to
  4751 follow natural argument order (for use with fold etc.);
  4752 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4753 
  4754 * Pure/General: output via the Isabelle channels of
  4755 writeln/warning/error etc. is now passed through Output.output, with a
  4756 hook for arbitrary transformations depending on the print_mode
  4757 (cf. Output.add_mode -- the first active mode that provides a output
  4758 function wins).  Already formatted output may be embedded into further
  4759 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4760 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4761 accommodate easy composition of diagnostic messages etc.  Programmers
  4762 rarely need to care about Output.output or Output.raw at all, with
  4763 some notable exceptions: Output.output is required when bypassing the
  4764 standard channels (writeln etc.), or in token translations to produce
  4765 properly formatted results; Output.raw is required when capturing
  4766 already output material that will eventually be presented to the user
  4767 a second time.  For the default print mode, both Output.output and
  4768 Output.raw have no effect.
  4769 
  4770 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4771 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4772 cumulative results are displayed at the end of a batch session.
  4773 
  4774 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4775 replaced by File.platform_path and File.shell_path (with appropriate
  4776 hooks).  This provides a clean interface for unusual systems where the
  4777 internal and external process view of file names are different.
  4778 
  4779 * Pure: more efficient orders for basic syntactic entities: added
  4780 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4781 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4782 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4783 orders now -- potential INCOMPATIBILITY for code that depends on a
  4784 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4785 Library.sort_strings on result).
  4786 
  4787 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4788 fold_types traverse types/terms from left to right, observing natural
  4789 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4790 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4791 
  4792 * Pure: name spaces have been refined, with significant changes of the
  4793 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4794 to extern(_table).  The plain name entry path is superceded by a
  4795 general 'naming' context, which also includes the 'policy' to produce
  4796 a fully qualified name and external accesses of a fully qualified
  4797 name; NameSpace.extend is superceded by context dependent
  4798 Sign.declare_name.  Several theory and proof context operations modify
  4799 the naming context.  Especially note Theory.restore_naming and
  4800 ProofContext.restore_naming to get back to a sane state; note that
  4801 Theory.add_path is no longer sufficient to recover from
  4802 Theory.absolute_path in particular.
  4803 
  4804 * Pure: new flags short_names (default false) and unique_names
  4805 (default true) for controlling output of qualified names.  If
  4806 short_names is set, names are printed unqualified.  If unique_names is
  4807 reset, the name prefix is reduced to the minimum required to achieve
  4808 the original result when interning again, even if there is an overlap
  4809 with earlier declarations.
  4810 
  4811 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4812 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4813 (useful for printing error messages).  INCOMPATIBILITY.
  4814 
  4815 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4816 Theory.theory are now identified, referring to the universal
  4817 Context.theory (see Pure/context.ML).  Actual signature and theory
  4818 content is managed as theory data.  The old code and interfaces were
  4819 spread over many files and structures; the new arrangement introduces
  4820 considerable INCOMPATIBILITY to gain more clarity:
  4821 
  4822   Context -- theory management operations (name, identity, inclusion,
  4823     parents, ancestors, merge, etc.), plus generic theory data;
  4824 
  4825   Sign -- logical signature and syntax operations (declaring consts,
  4826     types, etc.), plus certify/read for common entities;
  4827 
  4828   Theory -- logical theory operations (stating axioms, definitions,
  4829     oracles), plus a copy of logical signature operations (consts,
  4830     types, etc.); also a few basic management operations (Theory.copy,
  4831     Theory.merge, etc.)
  4832 
  4833 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4834 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4835 for convenience -- they merely return the theory.
  4836 
  4837 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4838 
  4839 * Pure: the Isar proof context type is already defined early in Pure
  4840 as Context.proof (note that ProofContext.context and Proof.context are
  4841 aliases, where the latter is the preferred name).  This enables other
  4842 Isabelle components to refer to that type even before Isar is present.
  4843 
  4844 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4845 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4846 any of these kinds.  For example, Sign.intern typeK is now
  4847 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4848 Theory.hide_types.  Also note that former
  4849 Theory.hide_classes/types/consts are now
  4850 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4851 internalize their arguments!  INCOMPATIBILITY.
  4852 
  4853 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4854 datatype thmref (with constructors Name and NameSelection) instead of
  4855 plain string -- INCOMPATIBILITY;
  4856 
  4857 * Pure: cases produced by proof methods specify options, where NONE
  4858 means to remove case bindings -- INCOMPATIBILITY in
  4859 (RAW_)METHOD_CASES.
  4860 
  4861 * Pure: the following operations retrieve axioms or theorems from a
  4862 theory node or theory hierarchy, respectively:
  4863 
  4864   Theory.axioms_of: theory -> (string * term) list
  4865   Theory.all_axioms_of: theory -> (string * term) list
  4866   PureThy.thms_of: theory -> (string * thm) list
  4867   PureThy.all_thms_of: theory -> (string * thm) list
  4868 
  4869 * Pure: print_tac now outputs the goal through the trace channel.
  4870 
  4871 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4872 Reference Toplevel.debug (default false) controls detailed printing
  4873 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4874 controls execution profiling -- set to 1 for time and 2 for space
  4875 (both increase the runtime).
  4876 
  4877 * Isar session: The initial use of ROOT.ML is now always timed,
  4878 i.e. the log will show the actual process times, in contrast to the
  4879 elapsed wall-clock time that the outer shell wrapper produces.
  4880 
  4881 * Simplifier: improved handling of bound variables (nameless
  4882 representation, avoid allocating new strings).  Simprocs that invoke
  4883 the Simplifier recursively should use Simplifier.inherit_bounds to
  4884 avoid local name clashes.  Failure to do so produces warnings
  4885 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4886 for further details.
  4887 
  4888 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4889 bindings for all theorems stored within a given theory; this may help
  4890 in porting non-Isar theories to Isar ones, while keeping ML proof
  4891 scripts for the time being.
  4892 
  4893 * ML operator HTML.with_charset specifies the charset begin used for
  4894 generated HTML files.  For example:
  4895 
  4896   HTML.with_charset "utf-8" use_thy "Hebrew";
  4897   HTML.with_charset "utf-8" use_thy "Chinese";
  4898 
  4899 
  4900 *** System ***
  4901 
  4902 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4903 isabelle, isatool etc.).
  4904 
  4905 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4906 isatool doc, isatool mkdir, display_drafts etc.).
  4907 
  4908 * isatool usedir: option -f allows specification of the ML file to be
  4909 used by Isabelle; default is ROOT.ML.
  4910 
  4911 * New isatool version outputs the version identifier of the Isabelle
  4912 distribution being used.
  4913 
  4914 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4915 (containing Boolean satisfiability problems) into Isabelle/HOL
  4916 theories.
  4917 
  4918 
  4919 
  4920 New in Isabelle2004 (April 2004)
  4921 --------------------------------
  4922 
  4923 *** General ***
  4924 
  4925 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4926   Replaces linorder.ML.
  4927 
  4928 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4929   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4930   (\<a>...\<z>), are now considered normal letters, and can therefore
  4931   be used anywhere where an ASCII letter (a...zA...Z) has until
  4932   now. COMPATIBILITY: This obviously changes the parsing of some
  4933   terms, especially where a symbol has been used as a binder, say
  4934   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4935   as an identifier.  Fix it by inserting a space around former
  4936   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4937   existing theory and ML files.
  4938 
  4939 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4940 
  4941 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4942   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4943   a normal (but invisible) letter. For multiple letter subscripts repeat
  4944   \<^isub> like this: x\<^isub>1\<^isub>2.
  4945 
  4946 * Pure: There are now sub-/superscripts that can span more than one
  4947   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4948   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4949   superscript. The new control characters are not identifier parts.
  4950 
  4951 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4952   content of "..." to the latex file instead of \isacntrl... . The "..."
  4953   may consist of any printable characters excluding the end bracket >.
  4954 
  4955 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4956   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4957   declare constants "final", which prevents their being given a definition
  4958   later.  It is useful for constants whose behaviour is fixed axiomatically
  4959   rather than definitionally, such as the meta-logic connectives.
  4960 
  4961 * Pure: 'instance' now handles general arities with general sorts
  4962   (i.e. intersections of classes),
  4963 
  4964 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4965   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4966   It can be changed to alter the colors/layout of generated pages.
  4967 
  4968 
  4969 *** Isar ***
  4970 
  4971 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4972   cut_tac, subgoal_tac and thin_tac:
  4973   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4974     locales are no longer forced to write Isar proof scripts.
  4975     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4976     emulations.
  4977   - INCOMPATIBILITY: names of variables to be instantiated may no
  4978     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4979     This is consistent with the instantiation attribute "where".
  4980 
  4981 * Attributes "where" and "of":
  4982   - Now take type variables of instantiated theorem into account when reading
  4983     the instantiation string.  This fixes a bug that caused instantiated
  4984     theorems to have too special types in some circumstances.
  4985   - "where" permits explicit instantiations of type variables.
  4986 
  4987 * Calculation commands "moreover" and "also" no longer interfere with
  4988   current facts ("this"), admitting arbitrary combinations with "then"
  4989   and derived forms.
  4990 
  4991 * Locales:
  4992   - Goal statements involving the context element "includes" no longer
  4993     generate theorems with internal delta predicates (those ending on
  4994     "_axioms") in the premise.
  4995     Resolve particular premise with <locale>.intro to obtain old form.
  4996   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4997     specification and "includes" elements in goal statement.
  4998   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4999     [intro?] and [elim?] (respectively) by default.
  5000   - Experimental command for instantiation of locales in proof contexts:
  5001         instantiate <label>[<attrs>]: <loc>
  5002     Instantiates locale <loc> and adds all its theorems to the current context
  5003     taking into account their attributes.  Label and attrs are optional
  5004     modifiers, like in theorem declarations.  If present, names of
  5005     instantiated theorems are qualified with <label>, and the attributes
  5006     <attrs> are applied after any attributes these theorems might have already.
  5007       If the locale has assumptions, a chained fact of the form
  5008     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5009     are derived.  The command does not support old-style locales declared
  5010     with "locale (open)".
  5011       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5012 
  5013 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5014   (Isar) contexts.
  5015 
  5016 
  5017 *** HOL ***
  5018 
  5019 * Proof import: new image HOL4 contains the imported library from
  5020   the HOL4 system with about 2500 theorems. It is imported by
  5021   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5022   can be used like any other Isabelle image.  See
  5023   HOL/Import/HOL/README for more information.
  5024 
  5025 * Simplifier:
  5026   - Much improved handling of linear and partial orders.
  5027     Reasoners for linear and partial orders are set up for type classes
  5028     "linorder" and "order" respectively, and are added to the default simpset
  5029     as solvers.  This means that the simplifier can build transitivity chains
  5030     to solve goals from the assumptions.
  5031   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5032     of blast or auto after simplification become unnecessary because the goal
  5033     is solved by simplification already.
  5034 
  5035 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5036     all proved in axiomatic type classes for semirings, rings and fields.
  5037 
  5038 * Numerics:
  5039   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5040     now formalized using the Ring_and_Field theory mentioned above.
  5041   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5042     than before, because now they are set up once in a generic manner.
  5043   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5044     Look for the general versions in Ring_and_Field (and Power if they concern
  5045     exponentiation).
  5046 
  5047 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5048 
  5049 * Records:
  5050   - Record types are now by default printed with their type abbreviation
  5051     instead of the list of all field types. This can be configured via
  5052     the reference "print_record_type_abbr".
  5053   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5054     (not enabled by default).
  5055   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5056     EX x. x = sel r to True (not enabled by default).
  5057   - Tactic "record_split_simp_tac" to split and simplify records added.
  5058 
  5059 * 'specification' command added, allowing for definition by
  5060   specification.  There is also an 'ax_specification' command that
  5061   introduces the new constants axiomatically.
  5062 
  5063 * arith(_tac) is now able to generate counterexamples for reals as well.
  5064 
  5065 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5066 
  5067 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5068   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5069 
  5070 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5071   matrix theory to linear programming.
  5072 
  5073 * Unions and Intersections:
  5074   The latex output syntax of UN and INT has been changed
  5075   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5076   i.e. the index formulae has become a subscript.
  5077   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5078 
  5079 * Unions and Intersections over Intervals:
  5080   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5081   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5082   like in normal math, and corresponding versions for < and for intersection.
  5083 
  5084 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5085   lexicographic dictonary ordering has been added as "lexord".
  5086 
  5087 * ML: the legacy theory structures Int and List have been removed. They had
  5088   conflicted with ML Basis Library structures having the same names.
  5089 
  5090 * 'refute' command added to search for (finite) countermodels.  Only works
  5091   for a fragment of HOL.  The installation of an external SAT solver is
  5092   highly recommended.  See "HOL/Refute.thy" for details.
  5093 
  5094 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5095   formulae under an assignment of free variables to random values.
  5096   In contrast to 'refute', it can deal with inductive datatypes,
  5097   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5098   for examples.
  5099 
  5100 
  5101 *** HOLCF ***
  5102 
  5103 * Streams now come with concatenation and are part of the HOLCF image
  5104 
  5105 
  5106 
  5107 New in Isabelle2003 (May 2003)
  5108 ------------------------------
  5109 
  5110 *** General ***
  5111 
  5112 * Provers/simplifier:
  5113 
  5114   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5115     Assumptions are now subject to complete mutual simplification,
  5116     not just from left to right. The simplifier now preserves
  5117     the order of assumptions.
  5118 
  5119     Potential INCOMPATIBILITY:
  5120 
  5121     -- simp sometimes diverges where the old version did
  5122        not, e.g. invoking simp on the goal
  5123 
  5124         [| P (f x); y = x; f x = f y |] ==> Q
  5125 
  5126        now gives rise to the infinite reduction sequence
  5127 
  5128         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5129 
  5130        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5131        kind of problem.
  5132 
  5133     -- Tactics combining classical reasoner and simplification (such as auto)
  5134        are also affected by this change, because many of them rely on
  5135        simp. They may sometimes diverge as well or yield a different numbers
  5136        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5137        in case of problems. Sometimes subsequent calls to the classical
  5138        reasoner will fail because a preceeding call to the simplifier too
  5139        eagerly simplified the goal, e.g. deleted redundant premises.
  5140 
  5141   - The simplifier trace now shows the names of the applied rewrite rules
  5142 
  5143   - You can limit the number of recursive invocations of the simplifier
  5144     during conditional rewriting (where the simplifie tries to solve the
  5145     conditions before applying the rewrite rule):
  5146     ML "simp_depth_limit := n"
  5147     where n is an integer. Thus you can force termination where previously
  5148     the simplifier would diverge.
  5149 
  5150   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5151 
  5152   - No longer aborts on failed congruence proof.  Instead, the
  5153     congruence is ignored.
  5154 
  5155 * Pure: New generic framework for extracting programs from constructive
  5156   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5157   as HOL/Extraction for some case studies.
  5158 
  5159 * Pure: The main goal of the proof state is no longer shown by default, only
  5160 the subgoals. This behaviour is controlled by a new flag.
  5161    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5162 (ML: Proof.show_main_goal).
  5163 
  5164 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5165 rules whose conclusion matches subgoal 1:
  5166       PG menu: Isabelle/Isar -> Show me -> matching rules
  5167 The rules are ordered by how closely they match the subgoal.
  5168 In particular, rules that solve a subgoal outright are displayed first
  5169 (or rather last, the way they are printed).
  5170 (ML: ProofGeneral.print_intros())
  5171 
  5172 * Pure: New flag trace_unify_fail causes unification to print
  5173 diagnostic information (PG: in trace buffer) when it fails. This is
  5174 useful for figuring out why single step proofs like rule, erule or
  5175 assumption failed.
  5176 
  5177 * Pure: Locale specifications now produce predicate definitions
  5178 according to the body of text (covering assumptions modulo local
  5179 definitions); predicate "loc_axioms" covers newly introduced text,
  5180 while "loc" is cumulative wrt. all included locale expressions; the
  5181 latter view is presented only on export into the global theory
  5182 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5183 on the old view without predicates;
  5184 
  5185 * Pure: predefined locales "var" and "struct" are useful for sharing
  5186 parameters (as in CASL, for example); just specify something like
  5187 ``var x + var y + struct M'' as import;
  5188 
  5189 * Pure: improved thms_containing: proper indexing of facts instead of
  5190 raw theorems; check validity of results wrt. current name space;
  5191 include local facts of proof configuration (also covers active
  5192 locales), cover fixed variables in index; may use "_" in term
  5193 specification; an optional limit for the number of printed facts may
  5194 be given (the default is 40);
  5195 
  5196 * Pure: disallow duplicate fact bindings within new-style theory files
  5197 (batch-mode only);
  5198 
  5199 * Provers: improved induct method: assumptions introduced by case
  5200 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5201 the goal statement); "foo" still refers to all facts collectively;
  5202 
  5203 * Provers: the function blast.overloaded has been removed: all constants
  5204 are regarded as potentially overloaded, which improves robustness in exchange
  5205 for slight decrease in efficiency;
  5206 
  5207 * Provers/linorder: New generic prover for transitivity reasoning over
  5208 linear orders.  Note: this prover is not efficient!
  5209 
  5210 * Isar: preview of problems to finish 'show' now produce an error
  5211 rather than just a warning (in interactive mode);
  5212 
  5213 
  5214 *** HOL ***
  5215 
  5216 * arith(_tac)
  5217 
  5218  - Produces a counter example if it cannot prove a goal.
  5219    Note that the counter example may be spurious if the goal is not a formula
  5220    of quantifier-free linear arithmetic.
  5221    In ProofGeneral the counter example appears in the trace buffer.
  5222 
  5223  - Knows about div k and mod k where k is a numeral of type nat or int.
  5224 
  5225  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5226    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5227    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5228 
  5229 * simp's arithmetic capabilities have been enhanced a bit: it now
  5230 takes ~= in premises into account (by performing a case split);
  5231 
  5232 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5233 are distributed over a sum of terms;
  5234 
  5235 * New tactic "trans_tac" and method "trans" instantiate
  5236 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5237 "<=", "<" and "=").
  5238 
  5239 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5240 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5241 
  5242 * 'typedef' command has new option "open" to suppress the set
  5243 definition;
  5244 
  5245 * functions Min and Max on finite sets have been introduced (theory
  5246 Finite_Set);
  5247 
  5248 * attribute [symmetric] now works for relations as well; it turns
  5249 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5250 
  5251 * induct over a !!-quantified statement (say !!x1..xn):
  5252   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5253 
  5254 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5255 %x. None. Warning: empty_def now refers to the previously hidden definition
  5256 of the empty set.
  5257 
  5258 * Algebra: formalization of classical algebra.  Intended as base for
  5259 any algebraic development in Isabelle.  Currently covers group theory
  5260 (up to Sylow's theorem) and ring theory (Universal Property of
  5261 Univariate Polynomials).  Contributions welcome;
  5262 
  5263 * GroupTheory: deleted, since its material has been moved to Algebra;
  5264 
  5265 * Complex: new directory of the complex numbers with numeric constants,
  5266 nonstandard complex numbers, and some complex analysis, standard and
  5267 nonstandard (Jacques Fleuriot);
  5268 
  5269 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5270 
  5271 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5272 Fleuriot);
  5273 
  5274 * Real/HahnBanach: updated and adapted to locales;
  5275 
  5276 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5277 Gray and Kramer);
  5278 
  5279 * UNITY: added the Meier-Sanders theory of progress sets;
  5280 
  5281 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5282 as abstract algorithms, instantiated to the JVM;
  5283 
  5284 * Bali: Java source language formalization. Type system, operational
  5285 semantics, axiomatic semantics. Supported language features:
  5286 classes, interfaces, objects,virtual methods, static methods,
  5287 static/instance fields, arrays, access modifiers, definite
  5288 assignment, exceptions.
  5289 
  5290 
  5291 *** ZF ***
  5292 
  5293 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5294 universe, etc.);
  5295 
  5296 * Main ZF: virtually all theories converted to new-style format;
  5297 
  5298 
  5299 *** ML ***
  5300 
  5301 * Pure: Tactic.prove provides sane interface for internal proofs;
  5302 omits the infamous "standard" operation, so this is more appropriate
  5303 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5304 
  5305 * Pure: improved error reporting of simprocs;
  5306 
  5307 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5308 up simprocs;
  5309 
  5310 
  5311 *** Document preparation ***
  5312 
  5313 * uses \par instead of \\ for line breaks in theory text. This may
  5314 shift some page breaks in large documents. To get the old behaviour
  5315 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5316 
  5317 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5318 other packages
  5319 
  5320 * \<euro> now needs package babel/greek instead of marvosym (which
  5321 broke \Rightarrow)
  5322 
  5323 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5324 textcomp package)
  5325 
  5326 
  5327 
  5328 New in Isabelle2002 (March 2002)
  5329 --------------------------------
  5330 
  5331 *** Document preparation ***
  5332 
  5333 * greatly simplified document preparation setup, including more
  5334 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5335 instructive isatool mkdir; users should basically be able to get
  5336 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5337 users may run a separate document processing stage manually like this:
  5338 "isatool usedir -D output HOL Test && isatool document Test/output";
  5339 
  5340 * theory dependency graph may now be incorporated into documents;
  5341 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5342 with \includegraphics of LaTeX;
  5343 
  5344 * proper spacing of consecutive markup elements, especially text
  5345 blocks after section headings;
  5346 
  5347 * support bold style (for single symbols only), input syntax is like
  5348 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5349 
  5350 * \<bullet> is now output as bold \cdot by default, which looks much
  5351 better in printed text;
  5352 
  5353 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5354 note that these symbols are currently unavailable in Proof General /
  5355 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5356 
  5357 * isatool latex no longer depends on changed TEXINPUTS, instead
  5358 isatool document copies the Isabelle style files to the target
  5359 location;
  5360 
  5361 
  5362 *** Isar ***
  5363 
  5364 * Pure/Provers: improved proof by cases and induction;
  5365   - 'case' command admits impromptu naming of parameters (such as
  5366     "case (Suc n)");
  5367   - 'induct' method divinates rule instantiation from the inductive
  5368     claim; no longer requires excessive ?P bindings for proper
  5369     instantiation of cases;
  5370   - 'induct' method properly enumerates all possibilities of set/type
  5371     rules; as a consequence facts may be also passed through *type*
  5372     rules without further ado;
  5373   - 'induct' method now derives symbolic cases from the *rulified*
  5374     rule (before it used to rulify cases stemming from the internal
  5375     atomized version); this means that the context of a non-atomic
  5376     statement becomes is included in the hypothesis, avoiding the
  5377     slightly cumbersome show "PROP ?case" form;
  5378   - 'induct' may now use elim-style induction rules without chaining
  5379     facts, using ``missing'' premises from the goal state; this allows
  5380     rules stemming from inductive sets to be applied in unstructured
  5381     scripts, while still benefitting from proper handling of non-atomic
  5382     statements; NB: major inductive premises need to be put first, all
  5383     the rest of the goal is passed through the induction;
  5384   - 'induct' proper support for mutual induction involving non-atomic
  5385     rule statements (uses the new concept of simultaneous goals, see
  5386     below);
  5387   - append all possible rule selections, but only use the first
  5388     success (no backtracking);
  5389   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5390   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5391   - added 'print_induct_rules' (covered by help item in recent Proof
  5392     General versions);
  5393   - moved induct/cases attributes to Pure, methods to Provers;
  5394   - generic method setup instantiated for FOL and HOL;
  5395 
  5396 * Pure: support multiple simultaneous goal statements, for example
  5397 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5398 meta-level mechanism, this acts as if several individual goals had
  5399 been stated separately; in particular common proof methods need to be
  5400 repeated in order to cover all claims; note that a single elimination
  5401 step is *not* sufficient to establish the two conjunctions, so this
  5402 fails:
  5403 
  5404   assume "A & B" then have A and B ..   (*".." fails*)
  5405 
  5406 better use "obtain" in situations as above; alternative refer to
  5407 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5408 
  5409 * Pure: proper integration with ``locales''; unlike the original
  5410 version by Florian Kammller, Isar locales package high-level proof
  5411 contexts rather than raw logical ones (e.g. we admit to include
  5412 attributes everywhere); operations on locales include merge and
  5413 rename; support for implicit arguments (``structures''); simultaneous
  5414 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5415 some examples;
  5416 
  5417 * Pure: the following commands have been ``localized'', supporting a
  5418 target locale specification "(in name)": 'lemma', 'theorem',
  5419 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5420 stored both within the locale and at the theory level (exported and
  5421 qualified by the locale name);
  5422 
  5423 * Pure: theory goals may now be specified in ``long'' form, with
  5424 ad-hoc contexts consisting of arbitrary locale elements. for example
  5425 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5426 definitions may be given, too); the result is a meta-level rule with
  5427 the context elements being discharged in the obvious way;
  5428 
  5429 * Pure: new proof command 'using' allows to augment currently used
  5430 facts after a goal statement ('using' is syntactically analogous to
  5431 'apply', but acts on the goal's facts only); this allows chained facts
  5432 to be separated into parts given before and after a claim, as in
  5433 ``from a and b have C using d and e <proof>'';
  5434 
  5435 * Pure: renamed "antecedent" case to "rule_context";
  5436 
  5437 * Pure: new 'judgment' command records explicit information about the
  5438 object-logic embedding (used by several tools internally); no longer
  5439 use hard-wired "Trueprop";
  5440 
  5441 * Pure: added 'corollary' command;
  5442 
  5443 * Pure: fixed 'token_translation' command;
  5444 
  5445 * Pure: removed obsolete 'exported' attribute;
  5446 
  5447 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5448 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5449 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5450 
  5451 * Pure: method 'atomize' presents local goal premises as object-level
  5452 statements (atomic meta-level propositions); setup controlled via
  5453 rewrite rules declarations of 'atomize' attribute; example
  5454 application: 'induct' method with proper rule statements in improper
  5455 proof *scripts*;
  5456 
  5457 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5458 now consider the syntactic context of assumptions, giving a better
  5459 chance to get type-inference of the arguments right (this is
  5460 especially important for locales);
  5461 
  5462 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5463 mode;
  5464 
  5465 * Pure/obtain: the formal conclusion "thesis", being marked as
  5466 ``internal'', may no longer be reference directly in the text;
  5467 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5468 situations;
  5469 
  5470 * Pure: generic 'sym' attribute which declares a rule both as pure
  5471 'elim?' and for the 'symmetric' operation;
  5472 
  5473 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5474 text; the fixed correlation with particular command syntax has been
  5475 discontinued;
  5476 
  5477 * Pure: new method 'rules' is particularly well-suited for proof
  5478 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5479 but often produces more compact proof terms with less detours;
  5480 
  5481 * Pure/Provers/classical: simplified integration with pure rule
  5482 attributes and methods; the classical "intro?/elim?/dest?"
  5483 declarations coincide with the pure ones; the "rule" method no longer
  5484 includes classically swapped intros; "intro" and "elim" methods no
  5485 longer pick rules from the context; also got rid of ML declarations
  5486 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5487 INCOMPATIBILITY;
  5488 
  5489 * Provers/classical: attribute 'swapped' produces classical inversions
  5490 of introduction rules;
  5491 
  5492 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5493 rules instead of full simplifier context; 'iff' attribute handles
  5494 conditional rules;
  5495 
  5496 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5497 
  5498 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5499 "(permissive)" option to recover old behavior;
  5500 
  5501 * HOL: 'inductive' no longer features separate (collective) attributes
  5502 for 'intros' (was found too confusing);
  5503 
  5504 * HOL: properly declared induction rules less_induct and
  5505 wf_induct_rule;
  5506 
  5507 
  5508 *** HOL ***
  5509 
  5510 * HOL: moved over to sane numeral syntax; the new policy is as
  5511 follows:
  5512 
  5513   - 0 and 1 are polymorphic constants, which are defined on any
  5514   numeric type (nat, int, real etc.);
  5515 
  5516   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5517   binary representation internally;
  5518 
  5519   - type nat has special constructor Suc, and generally prefers Suc 0
  5520   over 1::nat and Suc (Suc 0) over 2::nat;
  5521 
  5522 This change may cause significant problems of INCOMPATIBILITY; here
  5523 are some hints on converting existing sources:
  5524 
  5525   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5526   entities, so expressions involving "-" (unary or binary minus) need
  5527   to be spaced properly;
  5528 
  5529   - existing occurrences of "1" may need to be constraint "1::nat" or
  5530   even replaced by Suc 0; similar for old "2";
  5531 
  5532   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5533 
  5534   - remove all special provisions on numerals in proofs;
  5535 
  5536 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5537 representation (depends on bin_arith_simps in the default context);
  5538 
  5539 * HOL: symbolic syntax for x^2 (numeral 2);
  5540 
  5541 * HOL: the class of all HOL types is now called "type" rather than
  5542 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5543 in axclass/classes, instance/arities, and (usually rare) occurrences
  5544 in typings (of consts etc.); internally the class is called
  5545 "HOL.type", ML programs should refer to HOLogic.typeS;
  5546 
  5547 * HOL/record package improvements:
  5548   - new derived operations "fields" to build a partial record section,
  5549     "extend" to promote a fixed record to a record scheme, and
  5550     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5551     declared as simp by default;
  5552   - shared operations ("more", "fields", etc.) now need to be always
  5553     qualified) --- potential INCOMPATIBILITY;
  5554   - removed "make_scheme" operations (use "make" with "extend") --
  5555     INCOMPATIBILITY;
  5556   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5557   - provides cases/induct rules for use with corresponding Isar
  5558     methods (for concrete records, record schemes, concrete more
  5559     parts, and schematic more parts -- in that order);
  5560   - internal definitions directly based on a light-weight abstract
  5561     theory of product types over typedef rather than datatype;
  5562 
  5563 * HOL: generic code generator for generating executable ML code from
  5564 specifications; specific support for HOL constructs such as inductive
  5565 datatypes and sets, as well as recursive functions; can be invoked
  5566 via 'generate_code' theory section;
  5567 
  5568 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5569 
  5570 * HOL: consolidated and renamed several theories.  In particular:
  5571         Ord.thy has been absorbed into HOL.thy
  5572         String.thy has been absorbed into List.thy
  5573 
  5574 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5575 (beware of argument permutation!);
  5576 
  5577 * HOL: linorder_less_split superseded by linorder_cases;
  5578 
  5579 * HOL/List: "nodups" renamed to "distinct";
  5580 
  5581 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5582 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5583   - Ex_def has changed, now need to use some_eq_ex
  5584 
  5585 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5586 in this (rare) case use:
  5587 
  5588   delSWrapper "split_all_tac"
  5589   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5590 
  5591 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5592 MAY FAIL;
  5593 
  5594 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5595 Isabelle's type classes, ^ on functions and relations has too general
  5596 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5597 necessary to attach explicit type constraints;
  5598 
  5599 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5600 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5601 renamed accordingly (eg "compI" -> "rel_compI").
  5602 
  5603 * HOL: syntax translations now work properly with numerals and records
  5604 expressions;
  5605 
  5606 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5607 of "lam" -- INCOMPATIBILITY;
  5608 
  5609 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5610 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5611 renamed "Product_Type.unit";
  5612 
  5613 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5614 
  5615 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5616 the "cases" method);
  5617 
  5618 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5619 Florian Kammller);
  5620 
  5621 * HOL/IMP: updated and converted to new-style theory format; several
  5622 parts turned into readable document, with proper Isar proof texts and
  5623 some explanations (by Gerwin Klein);
  5624 
  5625 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5626 
  5627 * HOL-Hyperreal is now a logic image;
  5628 
  5629 
  5630 *** HOLCF ***
  5631 
  5632 * Isar: consts/constdefs supports mixfix syntax for continuous
  5633 operations;
  5634 
  5635 * Isar: domain package adapted to new-style theory format, e.g. see
  5636 HOLCF/ex/Dnat.thy;
  5637 
  5638 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5639 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5640 lift.induct_tac, always use UU instead of Undef;
  5641 
  5642 * HOLCF/IMP: updated and converted to new-style theory;
  5643 
  5644 
  5645 *** ZF ***
  5646 
  5647 * Isar: proper integration of logic-specific tools and packages,
  5648 including theory commands '(co)inductive', '(co)datatype',
  5649 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5650 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5651 
  5652 * theory Main no longer includes AC; for the Axiom of Choice, base
  5653 your theory on Main_ZFC;
  5654 
  5655 * the integer library now covers quotients and remainders, with many
  5656 laws relating division to addition, multiplication, etc.;
  5657 
  5658 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5659 typeless version of the formalism;
  5660 
  5661 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5662 format;
  5663 
  5664 * ZF/Induct: new directory for examples of inductive definitions,
  5665 including theory Multiset for multiset orderings; converted to
  5666 new-style theory format;
  5667 
  5668 * ZF: many new theorems about lists, ordinals, etc.;
  5669 
  5670 
  5671 *** General ***
  5672 
  5673 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5674 variable proof controls level of detail: 0 = no proofs (only oracle
  5675 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5676 also ref manual for further ML interfaces;
  5677 
  5678 * Pure/axclass: removed obsolete ML interface
  5679 goal_subclass/goal_arity;
  5680 
  5681 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5682 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5683 separate tokens, so expressions involving minus need to be spaced
  5684 properly;
  5685 
  5686 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5687 rather than "infixl" or "infixr";
  5688 
  5689 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5690 sort constraint specifications in type inference; e.g. "x::_::foo"
  5691 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5692 type variable);
  5693 
  5694 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5695 control output of nested => (types); the default behavior is
  5696 "type_brackets";
  5697 
  5698 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5699 tokens into AST constants;
  5700 
  5701 * Pure/syntax: prefer later declarations of translations and print
  5702 translation functions; potential INCOMPATIBILITY: need to reverse
  5703 multiple declarations for same syntax element constant;
  5704 
  5705 * Pure/show_hyps reset by default (in accordance to existing Isar
  5706 practice);
  5707 
  5708 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5709 addSafter;
  5710 
  5711 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5712 as well;
  5713 
  5714 * system: tested support for MacOS X; should be able to get Isabelle +
  5715 Proof General to work in a plain Terminal after installing Poly/ML
  5716 (e.g. from the Isabelle distribution area) and GNU bash alone
  5717 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5718 support requires further installations, e.g. from
  5719 http://fink.sourceforge.net/);
  5720 
  5721 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5722 
  5723 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5724 of 40 MB), cf. ML_OPTIONS;
  5725 
  5726 * system: Proof General keywords specification is now part of the
  5727 Isabelle distribution (see etc/isar-keywords.el);
  5728 
  5729 * system: support for persistent Proof General sessions (refrain from
  5730 outdating all loaded theories on startup); user may create writable
  5731 logic images like this: ``isabelle -q HOL Test'';
  5732 
  5733 * system: smart selection of Isabelle process versus Isabelle
  5734 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5735 run both "isabelle" and "Isabelle" even if file names are badly
  5736 damaged (executable inspects the case of the first letter of its own
  5737 name); added separate "isabelle-process" and "isabelle-interface";
  5738 
  5739 * system: refrain from any attempt at filtering input streams; no
  5740 longer support ``8bit'' encoding of old isabelle font, instead proper
  5741 iso-latin characters may now be used; the related isatools
  5742 "symbolinput" and "nonascii" have disappeared as well;
  5743 
  5744 * system: removed old "xterm" interface (the print modes "xterm" and
  5745 "xterm_color" are still available for direct use in a suitable
  5746 terminal);
  5747 
  5748 
  5749 
  5750 New in Isabelle99-2 (February 2001)
  5751 -----------------------------------
  5752 
  5753 *** Overview of INCOMPATIBILITIES ***
  5754 
  5755 * HOL: please note that theories in the Library and elsewhere often use the
  5756 new-style (Isar) format; to refer to their theorems in an ML script you must
  5757 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5758 
  5759 * HOL: inductive package no longer splits induction rule aggressively,
  5760 but only as far as specified by the introductions given; the old
  5761 format may be recovered via ML function complete_split_rule or attribute
  5762 'split_rule (complete)';
  5763 
  5764 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5765 gfp_Tarski to gfp_unfold;
  5766 
  5767 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5768 
  5769 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5770 relation); infix "^^" has been renamed "``"; infix "``" has been
  5771 renamed "`"; "univalent" has been renamed "single_valued";
  5772 
  5773 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5774 operation;
  5775 
  5776 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5777 
  5778 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5779 
  5780 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5781 consequence, it is no longer monotonic wrt. the local goal context
  5782 (which is now passed through the inductive cases);
  5783 
  5784 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5785 \<gg> to \<ggreater>;
  5786 
  5787 
  5788 *** Document preparation ***
  5789 
  5790 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5791 available: are "it" for near math-mode best-style output, "sl" for
  5792 slanted text style, and "tt" for plain type-writer; if no
  5793 \isabellestyle command is given, output is according to slanted
  5794 type-writer);
  5795 
  5796 * support sub/super scripts (for single symbols only), input syntax is
  5797 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5798 
  5799 * some more standard symbols; see Appendix A of the system manual for
  5800 the complete list of symbols defined in isabellesym.sty;
  5801 
  5802 * improved isabelle style files; more abstract symbol implementation
  5803 (should now use \isamath{...} and \isatext{...} in custom symbol
  5804 definitions);
  5805 
  5806 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5807 state; Note that presentation of goal states does not conform to
  5808 actual human-readable proof documents.  Please do not include goal
  5809 states into document output unless you really know what you are doing!
  5810 
  5811 * proper indentation of antiquoted output with proportional LaTeX
  5812 fonts;
  5813 
  5814 * no_document ML operator temporarily disables LaTeX document
  5815 generation;
  5816 
  5817 * isatool unsymbolize tunes sources for plain ASCII communication;
  5818 
  5819 
  5820 *** Isar ***
  5821 
  5822 * Pure: Isar now suffers initial goal statements to contain unbound
  5823 schematic variables (this does not conform to actual readable proof
  5824 documents, due to unpredictable outcome and non-compositional proof
  5825 checking); users who know what they are doing may use schematic goals
  5826 for Prolog-style synthesis of proven results;
  5827 
  5828 * Pure: assumption method (an implicit finishing) now handles actual
  5829 rules as well;
  5830 
  5831 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5832 initial goal, declare "that" only as Pure intro (only for single
  5833 steps); the "that" rule assumption may now be involved in implicit
  5834 finishing, thus ".." becomes a feasible for trivial obtains;
  5835 
  5836 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5837 instance proofs may be performed by "..";
  5838 
  5839 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5840 statements as well;
  5841 
  5842 * Pure: more robust selection of calculational rules;
  5843 
  5844 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5845 rule (as well as the assumption rule);
  5846 
  5847 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5848 lemmas, using the graph browser tool;
  5849 
  5850 * Pure: predict failure of "show" in interactive mode;
  5851 
  5852 * Pure: 'thms_containing' now takes actual terms as arguments;
  5853 
  5854 * HOL: improved method 'induct' --- now handles non-atomic goals
  5855 (potential INCOMPATIBILITY); tuned error handling;
  5856 
  5857 * HOL: cases and induct rules now provide explicit hints about the
  5858 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5859 any remaining facts are inserted into the goal verbatim;
  5860 
  5861 * HOL: local contexts (aka cases) may now contain term bindings as
  5862 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5863 the result to be shown in each case;
  5864 
  5865 * HOL: added 'recdef_tc' command;
  5866 
  5867 * isatool convert assists in eliminating legacy ML scripts;
  5868 
  5869 
  5870 *** HOL ***
  5871 
  5872 * HOL/Library: a collection of generic theories to be used together
  5873 with main HOL; the theory loader path already includes this directory
  5874 by default; the following existing theories have been moved here:
  5875 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5876 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5877 
  5878 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5879 modelling and verification task performed in Isabelle/HOL +
  5880 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5881 
  5882 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5883 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5884 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5885 'domain', this makes the theory consistent with mathematical
  5886 literature;
  5887 
  5888 * HOL basics: added overloaded operations "inverse" and "divide"
  5889 (infix "/"), syntax for generic "abs" operation, generic summation
  5890 operator \<Sum>;
  5891 
  5892 * HOL/typedef: simplified package, provide more useful rules (see also
  5893 HOL/subset.thy);
  5894 
  5895 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5896 now expressed as a proper nested rule (old-style tactic scripts may
  5897 require atomize_strip_tac to cope with non-atomic premises);
  5898 
  5899 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5900 to "split_conv" (old name still available for compatibility);
  5901 
  5902 * HOL: improved concrete syntax for strings (e.g. allows translation
  5903 rules with string literals);
  5904 
  5905 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5906  and Fleuriot's mechanization of analysis, including the transcendental
  5907  functions for the reals;
  5908 
  5909 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5910 
  5911 
  5912 *** CTT ***
  5913 
  5914 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5915 "lam" is displayed as TWO lambda-symbols
  5916 
  5917 * CTT: theory Main now available, containing everything (that is, Bool
  5918 and Arith);
  5919 
  5920 
  5921 *** General ***
  5922 
  5923 * Pure: the Simplifier has been implemented properly as a derived rule
  5924 outside of the actual kernel (at last!); the overall performance
  5925 penalty in practical applications is about 50%, while reliability of
  5926 the Isabelle inference kernel has been greatly improved;
  5927 
  5928 * print modes "brackets" and "no_brackets" control output of nested =>
  5929 (types) and ==> (props); the default behaviour is "brackets";
  5930 
  5931 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5932 as assumptions as well;
  5933 
  5934 * system: support Poly/ML 4.0;
  5935 
  5936 * system: isatool install handles KDE version 1 or 2;
  5937 
  5938 
  5939 
  5940 New in Isabelle99-1 (October 2000)
  5941 ----------------------------------
  5942 
  5943 *** Overview of INCOMPATIBILITIES ***
  5944 
  5945 * HOL: simplification of natural numbers is much changed; to partly
  5946 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5947 issue the following ML commands:
  5948 
  5949   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5950   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5951 
  5952 * HOL: simplification no longer dives into case-expressions; this is
  5953 controlled by "t.weak_case_cong" for each datatype t;
  5954 
  5955 * HOL: nat_less_induct renamed to less_induct;
  5956 
  5957 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5958 fixsome to patch .thy and .ML sources automatically;
  5959 
  5960   select_equality  -> some_equality
  5961   select_eq_Ex     -> some_eq_ex
  5962   selectI2EX       -> someI2_ex
  5963   selectI2         -> someI2
  5964   selectI          -> someI
  5965   select1_equality -> some1_equality
  5966   Eps_sym_eq       -> some_sym_eq_trivial
  5967   Eps_eq           -> some_eq_trivial
  5968 
  5969 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5970 
  5971 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5972 instead);
  5973 
  5974 * HOL: the recursion equations generated by 'recdef' are now called
  5975 f.simps instead of f.rules;
  5976 
  5977 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5978 
  5979 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5980 sometimes be needed;
  5981 
  5982 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5983 
  5984 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5985 
  5986 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5987 product is now "<*>" instead of "Times"; the lexicographic product is
  5988 now "<*lex*>" instead of "**";
  5989 
  5990 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5991 of main HOL, but was unused); better use HOL's datatype package;
  5992 
  5993 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5994 the old syntax may be recovered as follows:
  5995 
  5996   syntax (symbols)
  5997     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5998       (infixl "\\<oplus>" 100)
  5999 
  6000 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6001 
  6002 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6003 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6004 internally;
  6005 
  6006 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6007 changed from A/r to A//r;
  6008 
  6009 * ZF: new treatment of arithmetic (nat & int) may break some old
  6010 proofs;
  6011 
  6012 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6013 rulify -> rule_format, elimify -> elim_format, ...);
  6014 
  6015 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6016 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6017 should have to change intro!! to intro? only); replaced "delrule" by
  6018 "rule del";
  6019 
  6020 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6021 
  6022 * Provers: strengthened force_tac by using new first_best_tac;
  6023 
  6024 * LaTeX document preparation: several changes of isabelle.sty (see
  6025 lib/texinputs);
  6026 
  6027 
  6028 *** Document preparation ***
  6029 
  6030 * formal comments (text blocks etc.) in new-style theories may now
  6031 contain antiquotations of thm/prop/term/typ/text to be presented
  6032 according to latex print mode; concrete syntax is like this:
  6033 @{term[show_types] "f(x) = a + x"};
  6034 
  6035 * isatool mkdir provides easy setup of Isabelle session directories,
  6036 including proper document sources;
  6037 
  6038 * generated LaTeX sources are now deleted after successful run
  6039 (isatool document -c); may retain a copy somewhere else via -D option
  6040 of isatool usedir;
  6041 
  6042 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6043 style files, achieving self-contained LaTeX sources and simplifying
  6044 LaTeX debugging;
  6045 
  6046 * old-style theories now produce (crude) LaTeX output as well;
  6047 
  6048 * browser info session directories are now self-contained (may be put
  6049 on WWW server seperately); improved graphs of nested sessions; removed
  6050 graph for 'all sessions';
  6051 
  6052 * several improvements in isabelle style files; \isabellestyle{it}
  6053 produces fake math mode output; \isamarkupheader is now \section by
  6054 default; see lib/texinputs/isabelle.sty etc.;
  6055 
  6056 
  6057 *** Isar ***
  6058 
  6059 * Isar/Pure: local results and corresponding term bindings are now
  6060 subject to Hindley-Milner polymorphism (similar to ML); this
  6061 accommodates incremental type-inference very nicely;
  6062 
  6063 * Isar/Pure: new derived language element 'obtain' supports
  6064 generalized existence reasoning;
  6065 
  6066 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6067 support accumulation of results, without applying any rules yet;
  6068 useful to collect intermediate results without explicit name
  6069 references, and for use with transitivity rules with more than 2
  6070 premises;
  6071 
  6072 * Isar/Pure: scalable support for case-analysis type proofs: new
  6073 'case' language element refers to local contexts symbolically, as
  6074 produced by certain proof methods; internally, case names are attached
  6075 to theorems as "tags";
  6076 
  6077 * Isar/Pure: theory command 'hide' removes declarations from
  6078 class/type/const name spaces;
  6079 
  6080 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6081 indicate potential overloading;
  6082 
  6083 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6084 
  6085 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6086 "{a,b,c}" instead of {a,b,c};
  6087 
  6088 * Isar/Pure now provides its own version of intro/elim/dest
  6089 attributes; useful for building new logics, but beware of confusion
  6090 with the version in Provers/classical;
  6091 
  6092 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6093 case name 'antecedent';
  6094 
  6095 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6096 to the current context is now done automatically);
  6097 
  6098 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6099 for definining proof methods in ML;
  6100 
  6101 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6102 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6103 most cases, one should have to change intro!! to intro? only);
  6104 replaced "delrule" by "rule del";
  6105 
  6106 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6107 'symmetric' attribute (the latter supercedes [RS sym]);
  6108 
  6109 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6110 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6111 well (including splits);
  6112 
  6113 * Isar/Provers: Simplifier and Classical methods now support all kind
  6114 of modifiers used in the past, including 'cong', 'iff', etc.
  6115 
  6116 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6117 of Simplifier and Classical reasoner);
  6118 
  6119 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6120 now support named cases; major packages (inductive, datatype, primrec,
  6121 recdef) support case names and properly name parameters;
  6122 
  6123 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6124 monotonicity conditions are extracted to be proven at end of
  6125 calculations;
  6126 
  6127 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6128 method anyway;
  6129 
  6130 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6131 split_if split_if_asm; datatype package provides theorems foo.splits =
  6132 foo.split foo.split_asm for each datatype;
  6133 
  6134 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6135 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6136 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6137 use "(cases (simplified))" method in proper proof texts);
  6138 
  6139 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6140 
  6141 * Isar: names of theorems etc. may be natural numbers as well;
  6142 
  6143 * Isar: 'pr' command: optional arguments for goals_limit and
  6144 ProofContext.prems_limit; no longer prints theory contexts, but only
  6145 proof states;
  6146 
  6147 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6148 additional print modes to be specified; e.g. "pr(latex)" will print
  6149 proof state according to the Isabelle LaTeX style;
  6150 
  6151 * Isar: improved support for emulating tactic scripts, including proof
  6152 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6153 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6154 (for HOL datatypes);
  6155 
  6156 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6157 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6158 'proof method scripts' have to be in depth-first order;
  6159 
  6160 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6161 
  6162 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6163 should instead use individual commands for printing items
  6164 (print_commands, print_methods etc.);
  6165 
  6166 * Isar: added 'nothing' --- the empty list of theorems;
  6167 
  6168 
  6169 *** HOL ***
  6170 
  6171 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6172 corresponding virtual machine and a specification of its bytecode
  6173 verifier and a lightweight bytecode verifier, including proofs of
  6174 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6175 Cornelia Pusch (see also the homepage of project Bali at
  6176 http://isabelle.in.tum.de/Bali/);
  6177 
  6178 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6179 Clemens Ballarin;
  6180 
  6181 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6182 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6183 Rasmussen;
  6184 
  6185 * HOL/Lattice: fundamental concepts of lattice theory and order
  6186 structures, including duals, properties of bounds versus algebraic
  6187 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6188 Theorem for complete lattices etc.; may also serve as a demonstration
  6189 for abstract algebraic reasoning using axiomatic type classes, and
  6190 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6191 
  6192 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6193 von Oheimb;
  6194 
  6195 * HOL/IMPP: extension of IMP with local variables and mutually
  6196 recursive procedures, by David von Oheimb;
  6197 
  6198 * HOL/Lambda: converted into new-style theory and document;
  6199 
  6200 * HOL/ex/Multiquote: example of multiple nested quotations and
  6201 anti-quotations -- basically a generalized version of de-Bruijn
  6202 representation; very useful in avoiding lifting of operations;
  6203 
  6204 * HOL/record: added general record equality rule to simpset; fixed
  6205 select-update simplification procedure to handle extended records as
  6206 well; admit "r" as field name;
  6207 
  6208 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6209 other numeric types and also as the identity of groups, rings, etc.;
  6210 
  6211 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6212 Types nat and int belong to this axclass;
  6213 
  6214 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6215    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6216    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6217   two terms #m*u and #n*u are replaced by #(m+n)*u
  6218     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6219   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6220     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6221 
  6222 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6223 powerful prover for predicate logic but knows nothing of clasets; see
  6224 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6225 
  6226 * HOL: new version of "case_tac" subsumes both boolean case split and
  6227 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6228 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6229 
  6230 * HOL: simplification no longer dives into case-expressions: only the
  6231 selector expression is simplified, but not the remaining arms; to
  6232 enable full simplification of case-expressions for datatype t, you may
  6233 remove t.weak_case_cong from the simpset, either globally (Delcongs