NEWS
author haftmann
Mon Sep 13 14:53:56 2010 +0200 (2010-09-13)
changeset 39305 d4fa19eb0822
parent 39277 f263522ab226
child 39308 c2c9bb3c52c6
permissions -rw-r--r--
'class' and 'type' are now antiquoations by default
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    10 a Unicode character is treated as a single symbol, not a sequence of
    11 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    12 contain symbols without further backslash escapes, Unicode can now be
    13 used here as well.  Recall that Symbol.explode in ML provides a
    14 consistent view on symbols, while raw explode (or String.explode)
    15 merely give a byte-oriented representation.
    16 
    17 * Theory loading: only the master source file is looked-up in the
    18 implicit load path, all other files are addressed relatively to its
    19 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    20 
    21 * Special treatment of ML file names has been discontinued.
    22 Historically, optional extensions .ML or .sml were added on demand --
    23 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    24 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    25 
    26 * Various options that affect pretty printing etc. are now properly
    27 handled within the context via configuration options, instead of
    28 unsynchronized references.  There are both ML Config.T entities and
    29 Isar declaration attributes to access these.
    30 
    31   ML (Config.T)                 Isar (attribute)
    32 
    33   eta_contract                  eta_contract
    34   show_brackets                 show_brackets
    35   show_sorts                    show_sorts
    36   show_types                    show_types
    37   show_question_marks           show_question_marks
    38   show_consts                   show_consts
    39 
    40   Syntax.ambiguity_level        syntax_ambiguity_level
    41 
    42   Goal_Display.goals_limit      goals_limit
    43   Goal_Display.show_main_goal   show_main_goal
    44 
    45   Thy_Output.display            thy_output_display
    46   Thy_Output.quotes             thy_output_quotes
    47   Thy_Output.indent             thy_output_indent
    48   Thy_Output.source             thy_output_source
    49   Thy_Output.break              thy_output_break
    50 
    51 Note that corresponding "..._default" references in ML may be only
    52 changed globally at the ROOT session setup, but *not* within a theory.
    53 
    54 
    55 *** Pure ***
    56 
    57 * Interpretation command 'interpret' accepts a list of equations like
    58 'interpretation' does.
    59 
    60 * Diagnostic command 'print_interps' prints interpretations in proofs
    61 in addition to interpretations in theories.
    62 
    63 * Discontinued obsolete 'global' and 'local' commands to manipulate
    64 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    65 Sign.root_path and Sign.local_path may be applied directly where this
    66 feature is still required for historical reasons.
    67 
    68 * Discontinued ancient 'constdefs' command.  INCOMPATIBILITY, use
    69 'definition' instead.
    70 
    71 * Document antiquotations 'class' and 'type' for printing classes
    72 and type constructors.
    73 
    74 
    75 *** HOL ***
    76 
    77 * String.literal is a type, but not a datatype. INCOMPATIBILITY.
    78  
    79 * Renamed lemmas: expand_fun_eq -> ext_iff, expand_set_eq -> set_ext_iff
    80 
    81 * Renamed class eq and constant eq (for code generation) to class equal
    82 and constant equal, plus renaming of related facts and various tuning.
    83 INCOMPATIBILITY.
    84 
    85 * Scala (2.8 or higher) has been added to the target languages of
    86 the code generator.
    87 
    88 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    89 
    90 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    91 canonical names for instance definitions for functions; various improvements.
    92 INCOMPATIBILITY.
    93 
    94 * Records: logical foundation type for records do not carry a '_type' suffix
    95 any longer.  INCOMPATIBILITY.
    96 
    97 * Code generation for records: more idiomatic representation of record types.
    98 Warning: records are not covered by ancient SML code generation any longer.
    99 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
   100 helps to succeed then:
   101 
   102   record 'a foo = ...
   103   ...
   104   rep_datatype foo_ext ...
   105 
   106 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   107 INCOMPATIBILITY.
   108 
   109 * Quickcheck in locales considers interpretations of that locale for
   110 counter example search.
   111 
   112 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
   113 in Library/State_Monad has been changed to avoid ambiguities.
   114 INCOMPATIBILITY.
   115 
   116 * Code generator: export_code without explicit file declaration prints
   117 to standard output.  INCOMPATIBILITY.
   118 
   119 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   120 respectively.  INCOMPATIBILITY.
   121 
   122 * Constant "split" has been merged with constant "prod_case";  names
   123 of ML functions, facts etc. involving split have been retained so far,
   124 though.  INCOMPATIBILITY.
   125 
   126 * Dropped old infix syntax "mem" for List.member;  use "in set"
   127 instead.  INCOMPATIBILITY.
   128 
   129 * Refactoring of code-generation specific operations in List.thy
   130 
   131   constants
   132     null ~> List.null
   133 
   134   facts
   135     mem_iff ~> member_def
   136     null_empty ~> null_def
   137 
   138 INCOMPATIBILITY.  Note that these were not suppossed to be used
   139 regularly unless for striking reasons;  their main purpose was code
   140 generation.
   141 
   142 * Some previously unqualified names have been qualified:
   143 
   144   types
   145     bool ~> HOL.bool
   146     nat ~> Nat.nat
   147 
   148   constants
   149     Trueprop ~> HOL.Trueprop
   150     True ~> HOL.True
   151     False ~> HOL.False
   152     op & ~> HOL.conj
   153     op | ~> HOL.disj
   154     op --> ~> HOL.implies
   155     op = ~> HOL.eq
   156     Not ~> HOL.Not
   157     The ~> HOL.The
   158     All ~> HOL.All
   159     Ex ~> HOL.Ex
   160     Ex1 ~> HOL.Ex1
   161     Let ~> HOL.Let
   162     If ~> HOL.If
   163     Ball ~> Set.Ball
   164     Bex ~> Set.Bex
   165     Suc ~> Nat.Suc
   166     Pair ~> Product_Type.Pair
   167     fst ~> Product_Type.fst
   168     snd ~> Product_Type.snd
   169     curry ~> Product_Type.curry
   170     op : ~> Set.member
   171     Collect ~> Set.Collect
   172 
   173 INCOMPATIBILITY.
   174 
   175 * Removed simplifier congruence rule of "prod_case", as has for long
   176 been the case with "split".  INCOMPATIBILITY.
   177 
   178 * Datatype package: theorems generated for executable equality
   179 (class eq) carry proper names and are treated as default code
   180 equations.
   181 
   182 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   183 INCOMPATIBILITY.
   184 
   185 * List.thy: use various operations from the Haskell prelude when
   186 generating Haskell code.
   187 
   188 * code_simp.ML and method code_simp: simplification with rules determined
   189 by code generator.
   190 
   191 * code generator: do not print function definitions for case
   192 combinators any longer.
   193 
   194 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   195 theorems are now stated in terms of euclidean spaces instead of finite
   196 cartesian products.
   197 
   198   types
   199     real ^ 'n ~>  'a::real_vector
   200               ~>  'a::euclidean_space
   201               ~>  'a::ordered_euclidean_space
   202         (depends on your needs)
   203 
   204   constants
   205      _ $ _        ~> _ $$ _
   206      \<chi> x. _  ~> \<chi>\<chi> x. _
   207      CARD('n)     ~> DIM('a)
   208 
   209 Also note that the indices are now natural numbers and not from some finite
   210 type. Finite cartesian products of euclidean spaces, products of euclidean
   211 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   212 
   213 INCOMPATIBILITY.
   214 
   215 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   216 as value for measures. Introduces Lebesgue Measure based on the integral in
   217 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   218 spaces.
   219 
   220  INCOMPATIBILITY.
   221 
   222 * Inductive package: offers new command "inductive_simps" to automatically
   223 derive instantiated and simplified equations for inductive predicates,
   224 similar to inductive_cases.
   225 
   226 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". surj_on is a
   227 generalization of surj, and "surj f" is now a abbreviation of "surj_on f UNIV".
   228 The theorems bij_def and surj_def are unchanged.
   229 
   230 *** FOL ***
   231 
   232 * All constant names are now qualified.  INCOMPATIBILITY.
   233 
   234 
   235 *** ZF ***
   236 
   237 * All constant names are now qualified.  INCOMPATIBILITY.
   238 
   239 
   240 *** ML ***
   241 
   242 * Configuration option show_question_marks only affects regular pretty
   243 printing of types and terms, not raw Term.string_of_vname.
   244 
   245 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   246 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   247 @{thms} for most purposes.
   248 
   249 * ML structure Unsynchronized never opened, not even in Isar
   250 interaction mode as before.  Old Unsynchronized.set etc. have been
   251 discontinued -- use plain := instead.  This should be *rare* anyway,
   252 since modern tools always work via official context data, notably
   253 configuration options.
   254 
   255 * ML antiquotations @{theory} and @{theory_ref} refer to named
   256 theories from the ancestry of the current context, not any accidental
   257 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   258 change in semantics.
   259 
   260 * Parallel and asynchronous execution requires special care concerning
   261 interrupts.  Structure Exn provides some convenience functions that
   262 avoid working directly with raw Interrupt.  User code must not absorb
   263 interrupts -- intermediate handling (for cleanup etc.) needs to be
   264 followed by re-raising of the original exception.  Another common
   265 source of mistakes are "handle _" patterns, which make the meaning of
   266 the program subject to physical effects of the environment.
   267 
   268 
   269 *** System ***
   270 
   271 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   272 
   273 
   274 
   275 New in Isabelle2009-2 (June 2010)
   276 ---------------------------------
   277 
   278 *** General ***
   279 
   280 * Authentic syntax for *all* logical entities (type classes, type
   281 constructors, term constants): provides simple and robust
   282 correspondence between formal entities and concrete syntax.  Within
   283 the parse tree / AST representations, "constants" are decorated by
   284 their category (class, type, const) and spelled out explicitly with
   285 their full internal name.
   286 
   287 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   288 and translations (translation rules and translation functions in ML).
   289 Some hints on upgrading:
   290 
   291   - Many existing uses of 'syntax' and 'translations' can be replaced
   292     by more modern 'type_notation', 'notation' and 'abbreviation',
   293     which are independent of this issue.
   294 
   295   - 'translations' require markup within the AST; the term syntax
   296     provides the following special forms:
   297 
   298       CONST c   -- produces syntax version of constant c from context
   299       XCONST c  -- literally c, checked as constant from context
   300       c         -- literally c, if declared by 'syntax'
   301 
   302     Plain identifiers are treated as AST variables -- occasionally the
   303     system indicates accidental variables via the error "rhs contains
   304     extra variables".
   305 
   306     Type classes and type constructors are marked according to their
   307     concrete syntax.  Some old translations rules need to be written
   308     for the "type" category, using type constructor application
   309     instead of pseudo-term application of the default category
   310     "logic".
   311 
   312   - 'parse_translation' etc. in ML may use the following
   313     antiquotations:
   314 
   315       @{class_syntax c}   -- type class c within parse tree / AST
   316       @{term_syntax c}    -- type constructor c within parse tree / AST
   317       @{const_syntax c}   -- ML version of "CONST c" above
   318       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   319 
   320   - Literal types within 'typed_print_translations', i.e. those *not*
   321     represented as pseudo-terms are represented verbatim.  Use @{class
   322     c} or @{type_name c} here instead of the above syntax
   323     antiquotations.
   324 
   325 Note that old non-authentic syntax was based on unqualified base
   326 names, so all of the above "constant" names would coincide.  Recall
   327 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   328 diagnose syntax problems.
   329 
   330 * Type constructors admit general mixfix syntax, not just infix.
   331 
   332 * Concrete syntax may be attached to local entities without a proof
   333 body, too.  This works via regular mixfix annotations for 'fix',
   334 'def', 'obtain' etc. or via the explicit 'write' command, which is
   335 similar to the 'notation' command in theory specifications.
   336 
   337 * Discontinued unnamed infix syntax (legacy feature for many years) --
   338 need to specify constant name and syntax separately.  Internal ML
   339 datatype constructors have been renamed from InfixName to Infix etc.
   340 Minor INCOMPATIBILITY.
   341 
   342 * Schematic theorem statements need to be explicitly markup as such,
   343 via commands 'schematic_lemma', 'schematic_theorem',
   344 'schematic_corollary'.  Thus the relevance of the proof is made
   345 syntactically clear, which impacts performance in a parallel or
   346 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   347 
   348 * Use of cumulative prems via "!" in some proof methods has been
   349 discontinued (old legacy feature).
   350 
   351 * References 'trace_simp' and 'debug_simp' have been replaced by
   352 configuration options stored in the context. Enabling tracing (the
   353 case of debugging is similar) in proofs works via
   354 
   355   using [[trace_simp = true]]
   356 
   357 Tracing is then active for all invocations of the simplifier in
   358 subsequent goal refinement steps. Tracing may also still be enabled or
   359 disabled via the ProofGeneral settings menu.
   360 
   361 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   362 'hide_fact' replace the former 'hide' KIND command.  Minor
   363 INCOMPATIBILITY.
   364 
   365 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   366 more efficient than combinations with -q1 or -q2.
   367 
   368 
   369 *** Pure ***
   370 
   371 * Proofterms record type-class reasoning explicitly, using the
   372 "unconstrain" operation internally.  This eliminates all sort
   373 constraints from a theorem and proof, introducing explicit
   374 OFCLASS-premises.  On the proof term level, this operation is
   375 automatically applied at theorem boundaries, such that closed proofs
   376 are always free of sort constraints.  INCOMPATIBILITY for tools that
   377 inspect proof terms.
   378 
   379 * Local theory specifications may depend on extra type variables that
   380 are not present in the result type -- arguments TYPE('a) :: 'a itself
   381 are added internally.  For example:
   382 
   383   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   384 
   385 * Predicates of locales introduced by classes carry a mandatory
   386 "class" prefix.  INCOMPATIBILITY.
   387 
   388 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   389 
   390 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   391 'class' instead.
   392 
   393 * Command 'code_reflect' allows to incorporate generated ML code into
   394 runtime environment; replaces immature code_datatype antiquotation.
   395 INCOMPATIBILITY.
   396 
   397 * Code generator: simple concept for abstract datatypes obeying
   398 invariants.
   399 
   400 * Code generator: details of internal data cache have no impact on the
   401 user space functionality any longer.
   402 
   403 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   404 subgoals.  This is more appropriate for interpretations with 'where'.
   405 INCOMPATIBILITY.
   406 
   407 * Command 'example_proof' opens an empty proof body.  This allows to
   408 experiment with Isar, without producing any persistent result.
   409 
   410 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   411 within a local theory context, with explicit checking of the
   412 constructors involved (in contrast to the raw 'syntax' versions).
   413 
   414 * Commands 'types' and 'typedecl' now work within a local theory
   415 context -- without introducing dependencies on parameters or
   416 assumptions, which is not possible in Isabelle/Pure.
   417 
   418 * Command 'defaultsort' has been renamed to 'default_sort', it works
   419 within a local theory context.  Minor INCOMPATIBILITY.
   420 
   421 
   422 *** HOL ***
   423 
   424 * Command 'typedef' now works within a local theory context -- without
   425 introducing dependencies on parameters or assumptions, which is not
   426 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   427 contain multiple interpretations of local typedefs (with different
   428 non-emptiness proofs), even in a global theory context.
   429 
   430 * New package for quotient types.  Commands 'quotient_type' and
   431 'quotient_definition' may be used for defining types and constants by
   432 quotient constructions.  An example is the type of integers created by
   433 quotienting pairs of natural numbers:
   434 
   435   fun
   436     intrel :: "(nat * nat) => (nat * nat) => bool"
   437   where
   438     "intrel (x, y) (u, v) = (x + v = u + y)"
   439 
   440   quotient_type int = "nat * nat" / intrel
   441     by (auto simp add: equivp_def expand_fun_eq)
   442 
   443   quotient_definition
   444     "0::int" is "(0::nat, 0::nat)"
   445 
   446 The method "lifting" can be used to lift of theorems from the
   447 underlying "raw" type to the quotient type.  The example
   448 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   449 construction and provides a reasoning infrastructure for finite sets.
   450 
   451 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   452 clash with new theory Quotient in Main HOL.
   453 
   454 * Moved the SMT binding into the main HOL session, eliminating
   455 separate HOL-SMT session.
   456 
   457 * List membership infix mem operation is only an input abbreviation.
   458 INCOMPATIBILITY.
   459 
   460 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   461 for future developements; former Library/Word.thy is still present in
   462 the AFP entry RSAPPS.
   463 
   464 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   465 longer shadowed.  INCOMPATIBILITY.
   466 
   467 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   468 INCOMPATIBILITY.
   469 
   470 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   471 INCOMPATIBILITY.
   472 
   473 * Dropped normalizing_semiring etc; use the facts in semiring classes
   474 instead.  INCOMPATIBILITY.
   475 
   476 * Dropped several real-specific versions of lemmas about floor and
   477 ceiling; use the generic lemmas from theory "Archimedean_Field"
   478 instead.  INCOMPATIBILITY.
   479 
   480   floor_number_of_eq         ~> floor_number_of
   481   le_floor_eq_number_of      ~> number_of_le_floor
   482   le_floor_eq_zero           ~> zero_le_floor
   483   le_floor_eq_one            ~> one_le_floor
   484   floor_less_eq_number_of    ~> floor_less_number_of
   485   floor_less_eq_zero         ~> floor_less_zero
   486   floor_less_eq_one          ~> floor_less_one
   487   less_floor_eq_number_of    ~> number_of_less_floor
   488   less_floor_eq_zero         ~> zero_less_floor
   489   less_floor_eq_one          ~> one_less_floor
   490   floor_le_eq_number_of      ~> floor_le_number_of
   491   floor_le_eq_zero           ~> floor_le_zero
   492   floor_le_eq_one            ~> floor_le_one
   493   floor_subtract_number_of   ~> floor_diff_number_of
   494   floor_subtract_one         ~> floor_diff_one
   495   ceiling_number_of_eq       ~> ceiling_number_of
   496   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   497   ceiling_le_zero_eq         ~> ceiling_le_zero
   498   ceiling_le_eq_one          ~> ceiling_le_one
   499   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   500   less_ceiling_eq_zero       ~> zero_less_ceiling
   501   less_ceiling_eq_one        ~> one_less_ceiling
   502   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   503   ceiling_less_eq_zero       ~> ceiling_less_zero
   504   ceiling_less_eq_one        ~> ceiling_less_one
   505   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   506   le_ceiling_eq_zero         ~> zero_le_ceiling
   507   le_ceiling_eq_one          ~> one_le_ceiling
   508   ceiling_subtract_number_of ~> ceiling_diff_number_of
   509   ceiling_subtract_one       ~> ceiling_diff_one
   510 
   511 * Theory "Finite_Set": various folding_XXX locales facilitate the
   512 application of the various fold combinators on finite sets.
   513 
   514 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   515 provides abstract red-black tree type which is backed by "RBT_Impl" as
   516 implementation.  INCOMPATIBILTY.
   517 
   518 * Theory Library/Coinductive_List has been removed -- superseded by
   519 AFP/thys/Coinductive.
   520 
   521 * Theory PReal, including the type "preal" and related operations, has
   522 been removed.  INCOMPATIBILITY.
   523 
   524 * Real: new development using Cauchy Sequences.
   525 
   526 * Split off theory "Big_Operators" containing setsum, setprod,
   527 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   528 
   529 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   530 "Int" etc.  INCOMPATIBILITY.
   531 
   532 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   533 
   534 * New set of rules "ac_simps" provides combined assoc / commute
   535 rewrites for all interpretations of the appropriate generic locales.
   536 
   537 * Renamed theory "OrderedGroup" to "Groups" and split theory
   538 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   539 appropriate and more consistent names suitable for name prefixes
   540 within the HOL theories.  INCOMPATIBILITY.
   541 
   542 * Some generic constants have been put to appropriate theories:
   543   - less_eq, less: Orderings
   544   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   545   - inverse, divide: Rings
   546 INCOMPATIBILITY.
   547 
   548 * More consistent naming of type classes involving orderings (and
   549 lattices):
   550 
   551     lower_semilattice                   ~> semilattice_inf
   552     upper_semilattice                   ~> semilattice_sup
   553 
   554     dense_linear_order                  ~> dense_linorder
   555 
   556     pordered_ab_group_add               ~> ordered_ab_group_add
   557     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   558     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   559     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   560     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   561     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   562     pordered_cancel_semiring            ~> ordered_cancel_semiring
   563     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   564     pordered_comm_ring                  ~> ordered_comm_ring
   565     pordered_comm_semiring              ~> ordered_comm_semiring
   566     pordered_ring                       ~> ordered_ring
   567     pordered_ring_abs                   ~> ordered_ring_abs
   568     pordered_semiring                   ~> ordered_semiring
   569 
   570     ordered_ab_group_add                ~> linordered_ab_group_add
   571     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   572     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   573     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   574     ordered_field                       ~> linordered_field
   575     ordered_field_no_lb                 ~> linordered_field_no_lb
   576     ordered_field_no_ub                 ~> linordered_field_no_ub
   577     ordered_field_dense_linear_order    ~> dense_linordered_field
   578     ordered_idom                        ~> linordered_idom
   579     ordered_ring                        ~> linordered_ring
   580     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   581     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   582     ordered_ring_strict                 ~> linordered_ring_strict
   583     ordered_semidom                     ~> linordered_semidom
   584     ordered_semiring                    ~> linordered_semiring
   585     ordered_semiring_1                  ~> linordered_semiring_1
   586     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   587     ordered_semiring_strict             ~> linordered_semiring_strict
   588 
   589   The following slightly odd type classes have been moved to a
   590   separate theory Library/Lattice_Algebras:
   591 
   592     lordered_ab_group_add               ~> lattice_ab_group_add
   593     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   594     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   595     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   596     lordered_ring                       ~> lattice_ring
   597 
   598 INCOMPATIBILITY.
   599 
   600 * Refined field classes:
   601   - classes division_ring_inverse_zero, field_inverse_zero,
   602     linordered_field_inverse_zero include rule inverse 0 = 0 --
   603     subsumes former division_by_zero class;
   604   - numerous lemmas have been ported from field to division_ring.
   605 INCOMPATIBILITY.
   606 
   607 * Refined algebra theorem collections:
   608   - dropped theorem group group_simps, use algebra_simps instead;
   609   - dropped theorem group ring_simps, use field_simps instead;
   610   - proper theorem collection field_simps subsumes former theorem
   611     groups field_eq_simps and field_simps;
   612   - dropped lemma eq_minus_self_iff which is a duplicate for
   613     equal_neg_zero.
   614 INCOMPATIBILITY.
   615 
   616 * Theory Finite_Set and List: some lemmas have been generalized from
   617 sets to lattices:
   618 
   619   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   620   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   621   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   622   union_Union_fold_union        ~> sup_Sup_fold_sup
   623   Inter_fold_inter              ~> Inf_fold_inf
   624   Union_fold_union              ~> Sup_fold_sup
   625   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   626   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   627   INTER_fold_inter              ~> INFI_fold_inf
   628   UNION_fold_union              ~> SUPR_fold_sup
   629 
   630 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   631 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   632 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   633 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   634 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   635 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   636 
   637 * Reorganized theory Multiset: swapped notation of pointwise and
   638 multiset order:
   639 
   640   - pointwise ordering is instance of class order with standard syntax
   641     <= and <;
   642   - multiset ordering has syntax <=# and <#; partial order properties
   643     are provided by means of interpretation with prefix
   644     multiset_order;
   645   - less duplication, less historical organization of sections,
   646     conversion from associations lists to multisets, rudimentary code
   647     generation;
   648   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   649     if needed.
   650 
   651 Renamed:
   652 
   653   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   654   multi_count_ext  ~>  multiset_ext
   655   diff_union_inverse2  ~>  diff_union_cancelR
   656 
   657 INCOMPATIBILITY.
   658 
   659 * Theory Permutation: replaced local "remove" by List.remove1.
   660 
   661 * Code generation: ML and OCaml code is decorated with signatures.
   662 
   663 * Theory List: added transpose.
   664 
   665 * Library/Nat_Bijection.thy is a collection of bijective functions
   666 between nat and other types, which supersedes the older libraries
   667 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   668 
   669   Constants:
   670   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   671   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   672   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   673   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   674   Countable.pair_encode           ~> prod_encode
   675   NatIso.prod2nat                 ~> prod_encode
   676   NatIso.nat2prod                 ~> prod_decode
   677   NatIso.sum2nat                  ~> sum_encode
   678   NatIso.nat2sum                  ~> sum_decode
   679   NatIso.list2nat                 ~> list_encode
   680   NatIso.nat2list                 ~> list_decode
   681   NatIso.set2nat                  ~> set_encode
   682   NatIso.nat2set                  ~> set_decode
   683 
   684   Lemmas:
   685   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   686   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   687   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   688   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   689   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   690   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   691   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   692   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   693   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   694   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   695   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   696   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   697   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   698 
   699 * Sledgehammer:
   700   - Renamed ATP commands:
   701     atp_info     ~> sledgehammer running_atps
   702     atp_kill     ~> sledgehammer kill_atps
   703     atp_messages ~> sledgehammer messages
   704     atp_minimize ~> sledgehammer minimize
   705     print_atps   ~> sledgehammer available_atps
   706     INCOMPATIBILITY.
   707   - Added user's manual ("isabelle doc sledgehammer").
   708   - Added option syntax and "sledgehammer_params" to customize
   709     Sledgehammer's behavior.  See the manual for details.
   710   - Modified the Isar proof reconstruction code so that it produces
   711     direct proofs rather than proofs by contradiction.  (This feature
   712     is still experimental.)
   713   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   714     full-typed mode.
   715   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   716 
   717 * Nitpick:
   718   - Added and implemented "binary_ints" and "bits" options.
   719   - Added "std" option and implemented support for nonstandard models.
   720   - Added and implemented "finitize" option to improve the precision
   721     of infinite datatypes based on a monotonicity analysis.
   722   - Added support for quotient types.
   723   - Added support for "specification" and "ax_specification"
   724     constructs.
   725   - Added support for local definitions (for "function" and
   726     "termination" proofs).
   727   - Added support for term postprocessors.
   728   - Optimized "Multiset.multiset" and "FinFun.finfun".
   729   - Improved efficiency of "destroy_constrs" optimization.
   730   - Fixed soundness bugs related to "destroy_constrs" optimization and
   731     record getters.
   732   - Fixed soundness bug related to higher-order constructors.
   733   - Fixed soundness bug when "full_descrs" is enabled.
   734   - Improved precision of set constructs.
   735   - Added "atoms" option.
   736   - Added cache to speed up repeated Kodkod invocations on the same
   737     problems.
   738   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   739     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   740     "SAT4J_Light".  INCOMPATIBILITY.
   741   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   742     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   743   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   744 
   745 * Method "induct" now takes instantiations of the form t, where t is not
   746   a variable, as a shorthand for "x == t", where x is a fresh variable.
   747   If this is not intended, t has to be enclosed in parentheses.
   748   By default, the equalities generated by definitional instantiations
   749   are pre-simplified, which may cause parameters of inductive cases
   750   to disappear, or may even delete some of the inductive cases.
   751   Use "induct (no_simp)" instead of "induct" to restore the old
   752   behaviour. The (no_simp) option is also understood by the "cases"
   753   and "nominal_induct" methods, which now perform pre-simplification, too.
   754   INCOMPATIBILITY.
   755 
   756 
   757 *** HOLCF ***
   758 
   759 * Variable names in lemmas generated by the domain package have
   760 changed; the naming scheme is now consistent with the HOL datatype
   761 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   762 
   763 * The domain package no longer defines the function "foo_copy" for
   764 recursive domain "foo".  The reach lemma is now stated directly in
   765 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   766 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   767 
   768 * Most definedness lemmas generated by the domain package (previously
   769 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   770 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   771 Proofs that used definedness lemmas as intro rules may break,
   772 potential INCOMPATIBILITY.
   773 
   774 * Induction and casedist rules generated by the domain package now
   775 declare proper case_names (one called "bottom", and one named for each
   776 constructor).  INCOMPATIBILITY.
   777 
   778 * For mutually-recursive domains, separate "reach" and "take_lemma"
   779 rules are generated for each domain, INCOMPATIBILITY.
   780 
   781   foo_bar.reach       ~> foo.reach  bar.reach
   782   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   783 
   784 * Some lemmas generated by the domain package have been renamed for
   785 consistency with the datatype package, INCOMPATIBILITY.
   786 
   787   foo.ind        ~> foo.induct
   788   foo.finite_ind ~> foo.finite_induct
   789   foo.coind      ~> foo.coinduct
   790   foo.casedist   ~> foo.exhaust
   791   foo.exhaust    ~> foo.nchotomy
   792 
   793 * For consistency with other definition packages, the fixrec package
   794 now generates qualified theorem names, INCOMPATIBILITY.
   795 
   796   foo_simps  ~> foo.simps
   797   foo_unfold ~> foo.unfold
   798   foo_induct ~> foo.induct
   799 
   800 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   801 method and internal fixrec proofs now use the default simpset instead.
   802 INCOMPATIBILITY.
   803 
   804 * The "contlub" predicate has been removed.  Proof scripts should use
   805 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   806 
   807 * The "admw" predicate has been removed, INCOMPATIBILITY.
   808 
   809 * The constants cpair, cfst, and csnd have been removed in favor of
   810 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   811 
   812 
   813 *** ML ***
   814 
   815 * Antiquotations for basic formal entities:
   816 
   817     @{class NAME}         -- type class
   818     @{class_syntax NAME}  -- syntax representation of the above
   819 
   820     @{type_name NAME}     -- logical type
   821     @{type_abbrev NAME}   -- type abbreviation
   822     @{nonterminal NAME}   -- type of concrete syntactic category
   823     @{type_syntax NAME}   -- syntax representation of any of the above
   824 
   825     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   826     @{const_abbrev NAME}  -- abbreviated constant
   827     @{const_syntax NAME}  -- syntax representation of any of the above
   828 
   829 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   830 syntax constant (cf. 'syntax' command).
   831 
   832 * Antiquotation @{make_string} inlines a function to print arbitrary
   833 values similar to the ML toplevel.  The result is compiler dependent
   834 and may fall back on "?" in certain situations.
   835 
   836 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   837 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   838 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   839 not work with the asynchronous Isar document model.
   840 
   841 * Configuration options now admit dynamic default values, depending on
   842 the context or even global references.
   843 
   844 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   845 uses an efficient external library if available (for Poly/ML).
   846 
   847 * Renamed some important ML structures, while keeping the old names
   848 for some time as aliases within the structure Legacy:
   849 
   850   OuterKeyword  ~>  Keyword
   851   OuterLex      ~>  Token
   852   OuterParse    ~>  Parse
   853   OuterSyntax   ~>  Outer_Syntax
   854   PrintMode     ~>  Print_Mode
   855   SpecParse     ~>  Parse_Spec
   856   ThyInfo       ~>  Thy_Info
   857   ThyLoad       ~>  Thy_Load
   858   ThyOutput     ~>  Thy_Output
   859   TypeInfer     ~>  Type_Infer
   860 
   861 Note that "open Legacy" simplifies porting of sources, but forgetting
   862 to remove it again will complicate porting again in the future.
   863 
   864 * Most operations that refer to a global context are named
   865 accordingly, e.g. Simplifier.global_context or
   866 ProofContext.init_global.  There are some situations where a global
   867 context actually works, but under normal circumstances one needs to
   868 pass the proper local context through the code!
   869 
   870 * Discontinued old TheoryDataFun with its copy/init operation -- data
   871 needs to be pure.  Functor Theory_Data_PP retains the traditional
   872 Pretty.pp argument to merge, which is absent in the standard
   873 Theory_Data version.
   874 
   875 * Sorts.certify_sort and derived "cert" operations for types and terms
   876 no longer minimize sorts.  Thus certification at the boundary of the
   877 inference kernel becomes invariant under addition of class relations,
   878 which is an important monotonicity principle.  Sorts are now minimized
   879 in the syntax layer only, at the boundary between the end-user and the
   880 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   881 explicitly in rare situations.
   882 
   883 * Renamed old-style Drule.standard to Drule.export_without_context, to
   884 emphasize that this is in no way a standard operation.
   885 INCOMPATIBILITY.
   886 
   887 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   888 usual for resolution.  Rare INCOMPATIBILITY.
   889 
   890 * Renamed varify/unvarify operations to varify_global/unvarify_global
   891 to emphasize that these only work in a global situation (which is
   892 quite rare).
   893 
   894 * Curried take and drop in library.ML; negative length is interpreted
   895 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   896 
   897 * Proof terms: type substitutions on proof constants now use canonical
   898 order of type variables.  INCOMPATIBILITY for tools working with proof
   899 terms.
   900 
   901 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   902 may no longer carry premises.  User-level specifications are
   903 transformed accordingly by Thm.add_axiom/add_def.
   904 
   905 
   906 *** System ***
   907 
   908 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   909 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   910 proof terms are enabled unconditionally in the new HOL-Proofs image.
   911 
   912 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   913 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   914 respectively.
   915 
   916 * Old lib/scripts/polyml-platform is superseded by the
   917 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   918 variant, even on a 64 bit machine.  The following example setting
   919 prefers 64 bit if available:
   920 
   921   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   922 
   923 * The preliminary Isabelle/jEdit application demonstrates the emerging
   924 Isabelle/Scala layer for advanced prover interaction and integration.
   925 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   926 component.
   927 
   928 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   929 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   930 similar to the default assignment of the document preparation system
   931 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   932 provides some operations for direct access to the font without asking
   933 the user for manual installation.
   934 
   935 
   936 
   937 New in Isabelle2009-1 (December 2009)
   938 -------------------------------------
   939 
   940 *** General ***
   941 
   942 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   943 one backslash should be used, even in ML sources.
   944 
   945 
   946 *** Pure ***
   947 
   948 * Locale interpretation propagates mixins along the locale hierarchy.
   949 The currently only available mixins are the equations used to map
   950 local definitions to terms of the target domain of an interpretation.
   951 
   952 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   953 loc" to print all interpretations of locale "loc" in the theory.
   954 Interpretations in proofs are not shown.
   955 
   956 * Thoroughly revised locales tutorial.  New section on conditional
   957 interpretation.
   958 
   959 * On instantiation of classes, remaining undefined class parameters
   960 are formally declared.  INCOMPATIBILITY.
   961 
   962 
   963 *** Document preparation ***
   964 
   965 * New generalized style concept for printing terms: @{foo (style) ...}
   966 instead of @{foo_style style ...}  (old form is still retained for
   967 backward compatibility).  Styles can be also applied for
   968 antiquotations prop, term_type and typeof.
   969 
   970 
   971 *** HOL ***
   972 
   973 * New proof method "smt" for a combination of first-order logic with
   974 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   975 fixed-size bitvectors; there is also basic support for higher-order
   976 features (esp. lambda abstractions).  It is an incomplete decision
   977 procedure based on external SMT solvers using the oracle mechanism;
   978 for the SMT solver Z3, this method is proof-producing.  Certificates
   979 are provided to avoid calling the external solvers solely for
   980 re-checking proofs.  Due to a remote SMT service there is no need for
   981 installing SMT solvers locally.  See src/HOL/SMT.
   982 
   983 * New commands to load and prove verification conditions generated by
   984 the Boogie program verifier or derived systems (e.g. the Verifying C
   985 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   986 
   987 * New counterexample generator tool 'nitpick' based on the Kodkod
   988 relational model finder.  See src/HOL/Tools/Nitpick and
   989 src/HOL/Nitpick_Examples.
   990 
   991 * New commands 'code_pred' and 'values' to invoke the predicate
   992 compiler and to enumerate values of inductive predicates.
   993 
   994 * A tabled implementation of the reflexive transitive closure.
   995 
   996 * New implementation of quickcheck uses generic code generator;
   997 default generators are provided for all suitable HOL types, records
   998 and datatypes.  Old quickcheck can be re-activated importing theory
   999 Library/SML_Quickcheck.
  1000 
  1001 * New testing tool Mirabelle for automated proof tools.  Applies
  1002 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1003 every proof step in a theory.  To be used in batch mode via the
  1004 "mirabelle" utility.
  1005 
  1006 * New proof method "sos" (sum of squares) for nonlinear real
  1007 arithmetic (originally due to John Harison). It requires theory
  1008 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1009 works well in practice on quantifier-free real arithmetic with +, -,
  1010 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1011 inequalities between polynomials.  It makes use of external
  1012 semidefinite programming solvers.  Method "sos" generates a
  1013 certificate that can be pasted into the proof thus avoiding the need
  1014 to call an external tool every time the proof is checked.  See
  1015 src/HOL/Library/Sum_Of_Squares.
  1016 
  1017 * New method "linarith" invokes existing linear arithmetic decision
  1018 procedure only.
  1019 
  1020 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1021 
  1022 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1023 Causes full type information to be output to the ATPs.  This slows
  1024 ATPs down considerably but eliminates a source of unsound "proofs"
  1025 that fail later.
  1026 
  1027 * New method "metisFT": A version of metis that uses full type
  1028 information in order to avoid failures of proof reconstruction.
  1029 
  1030 * New evaluator "approximate" approximates an real valued term using
  1031 the same method as the approximation method.
  1032 
  1033 * Method "approximate" now supports arithmetic expressions as
  1034 boundaries of intervals and implements interval splitting and Taylor
  1035 series expansion.
  1036 
  1037 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1038 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1039 
  1040 * New theory SupInf of the supremum and infimum operators for sets of
  1041 reals.
  1042 
  1043 * New theory Probability, which contains a development of measure
  1044 theory, eventually leading to Lebesgue integration and probability.
  1045 
  1046 * Extended Multivariate Analysis to include derivation and Brouwer's
  1047 fixpoint theorem.
  1048 
  1049 * Reorganization of number theory, INCOMPATIBILITY:
  1050   - new number theory development for nat and int, in theories Divides
  1051     and GCD as well as in new session Number_Theory
  1052   - some constants and facts now suffixed with _nat and _int
  1053     accordingly
  1054   - former session NumberTheory now named Old_Number_Theory, including
  1055     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1056   - moved theory Pocklington from src/HOL/Library to
  1057     src/HOL/Old_Number_Theory
  1058 
  1059 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1060 lcm of finite and infinite sets. It is shown that they form a complete
  1061 lattice.
  1062 
  1063 * Class semiring_div requires superclass no_zero_divisors and proof of
  1064 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1065 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1066 generalized to class semiring_div, subsuming former theorems
  1067 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1068 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1069 INCOMPATIBILITY.
  1070 
  1071 * Refinements to lattice classes and sets:
  1072   - less default intro/elim rules in locale variant, more default
  1073     intro/elim rules in class variant: more uniformity
  1074   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1075     le_inf_iff
  1076   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1077     sup_aci)
  1078   - renamed ACI to inf_sup_aci
  1079   - new class "boolean_algebra"
  1080   - class "complete_lattice" moved to separate theory
  1081     "Complete_Lattice"; corresponding constants (and abbreviations)
  1082     renamed and with authentic syntax:
  1083     Set.Inf ~>    Complete_Lattice.Inf
  1084     Set.Sup ~>    Complete_Lattice.Sup
  1085     Set.INFI ~>   Complete_Lattice.INFI
  1086     Set.SUPR ~>   Complete_Lattice.SUPR
  1087     Set.Inter ~>  Complete_Lattice.Inter
  1088     Set.Union ~>  Complete_Lattice.Union
  1089     Set.INTER ~>  Complete_Lattice.INTER
  1090     Set.UNION ~>  Complete_Lattice.UNION
  1091   - authentic syntax for
  1092     Set.Pow
  1093     Set.image
  1094   - mere abbreviations:
  1095     Set.empty               (for bot)
  1096     Set.UNIV                (for top)
  1097     Set.inter               (for inf, formerly Set.Int)
  1098     Set.union               (for sup, formerly Set.Un)
  1099     Complete_Lattice.Inter  (for Inf)
  1100     Complete_Lattice.Union  (for Sup)
  1101     Complete_Lattice.INTER  (for INFI)
  1102     Complete_Lattice.UNION  (for SUPR)
  1103   - object-logic definitions as far as appropriate
  1104 
  1105 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1106 Un_subset_iff are explicitly deleted as default simp rules; then also
  1107 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1108 deleted to achieve the desired effect.
  1109 
  1110 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1111 rules by default any longer; the same applies to min_max.inf_absorb1
  1112 etc.  INCOMPATIBILITY.
  1113 
  1114 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1115 pred_set_conv by default.  INCOMPATIBILITY.
  1116 
  1117 * Power operations on relations and functions are now one dedicated
  1118 constant "compow" with infix syntax "^^".  Power operation on
  1119 multiplicative monoids retains syntax "^" and is now defined generic
  1120 in class power.  INCOMPATIBILITY.
  1121 
  1122 * Relation composition "R O S" now has a more standard argument order:
  1123 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1124 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1125 break, since the O_assoc rule was not rewritten like this.  Fix using
  1126 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1127 
  1128 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1129 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1130 INCOMPATIBILITY.
  1131 
  1132 * Most rules produced by inductive and datatype package have mandatory
  1133 prefixes.  INCOMPATIBILITY.
  1134 
  1135 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1136 the attribute of the same name.  Each of the theorems in the list
  1137 DERIV_intros assumes composition with an additional function and
  1138 matches a variable to the derivative, which has to be solved by the
  1139 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1140 of most elementary terms.  Former Maclauren.DERIV_tac and
  1141 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1142 INCOMPATIBILITY.
  1143 
  1144 * Code generator attributes follow the usual underscore convention:
  1145     code_unfold     replaces    code unfold
  1146     code_post       replaces    code post
  1147     etc.
  1148   INCOMPATIBILITY.
  1149 
  1150 * Renamed methods:
  1151     sizechange -> size_change
  1152     induct_scheme -> induction_schema
  1153   INCOMPATIBILITY.
  1154 
  1155 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1156 INCOMPATIBILITY, use "undefined" directly.
  1157 
  1158 * Renamed theorems:
  1159     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1160     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1161     Suc_plus1 -> Suc_eq_plus1
  1162     *anti_sym -> *antisym*
  1163     vector_less_eq_def -> vector_le_def
  1164   INCOMPATIBILITY.
  1165 
  1166 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1167 INCOMPATIBILITY.
  1168 
  1169 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1170 INCOMPATIBILITY.
  1171 
  1172 
  1173 *** HOLCF ***
  1174 
  1175 * Theory Representable defines a class "rep" of domains that are
  1176 representable (via an ep-pair) in the universal domain type "udom".
  1177 Instances are provided for all type constructors defined in HOLCF.
  1178 
  1179 * The 'new_domain' command is a purely definitional version of the
  1180 domain package, for representable domains.  Syntax is identical to the
  1181 old domain package.  The 'new_domain' package also supports indirect
  1182 recursion using previously-defined type constructors.  See
  1183 src/HOLCF/ex/New_Domain.thy for examples.
  1184 
  1185 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1186 on the left-hand side of an equation, and then performs
  1187 simplification.  Rewriting is done using rules declared with the
  1188 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1189 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1190 
  1191 * The pattern-match compiler in 'fixrec' can now handle constructors
  1192 with HOL function types.  Pattern-match combinators for the Pair
  1193 constructor are pre-configured.
  1194 
  1195 * The 'fixrec' package now produces better fixed-point induction rules
  1196 for mutually-recursive definitions:  Induction rules have conclusions
  1197 of the form "P foo bar" instead of "P <foo, bar>".
  1198 
  1199 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1200 been renamed to "below".  The name "below" now replaces "less" in many
  1201 theorem names.  (Legacy theorem names using "less" are still supported
  1202 as well.)
  1203 
  1204 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1205 patterns can be used to generate strictness rules, or to make
  1206 functions more strict (much like the bang-patterns supported by the
  1207 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1208 examples.
  1209 
  1210 
  1211 *** ML ***
  1212 
  1213 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1214 errors and run-time exceptions, including detailed source positions.
  1215 
  1216 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1217 identified entries, with some additional information such as source
  1218 position, logical grouping etc.
  1219 
  1220 * Theory and context data is now introduced by the simplified and
  1221 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1222 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1223 copy operation) is still available for some time.
  1224 
  1225 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1226 provides a high-level programming interface to synchronized state
  1227 variables with atomic update.  This works via pure function
  1228 application within a critical section -- its runtime should be as
  1229 short as possible; beware of deadlocks if critical code is nested,
  1230 either directly or indirectly via other synchronized variables!
  1231 
  1232 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1233 wraps raw ML references, explicitly indicating their non-thread-safe
  1234 behaviour.  The Isar toplevel keeps this structure open, to
  1235 accommodate Proof General as well as quick and dirty interactive
  1236 experiments with references.
  1237 
  1238 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1239 parallel tactical reasoning.
  1240 
  1241 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1242 are similar to SUBPROOF, but are slightly more flexible: only the
  1243 specified parts of the subgoal are imported into the context, and the
  1244 body tactic may introduce new subgoals and schematic variables.
  1245 
  1246 * Old tactical METAHYPS, which does not observe the proof context, has
  1247 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1248 or Subgoal.FOCUS etc.
  1249 
  1250 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1251 functors have their own ML name space there is no point to mark them
  1252 separately.)  Minor INCOMPATIBILITY.
  1253 
  1254 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1255 
  1256 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1257 INCOMPATIBILITY.
  1258 
  1259 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1260 mode, which avoids critical setmp.
  1261 
  1262 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1263 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1264 Attrib/Method.setup introduced in Isabelle2009.
  1265 
  1266 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1267 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1268 last resort.  INCOMPATIBILITY.
  1269 
  1270 * Display.pretty_thm now requires a proper context (cf. former
  1271 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1272 or even Display.pretty_thm_without_context as last resort.
  1273 INCOMPATIBILITY.
  1274 
  1275 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1276 Syntax.pretty_typ/term directly, preferably with proper context
  1277 instead of global theory.
  1278 
  1279 
  1280 *** System ***
  1281 
  1282 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1283 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1284 usedir option -q.
  1285 
  1286 * Support for additional "Isabelle components" via etc/components, see
  1287 also the system manual.
  1288 
  1289 * The isabelle makeall tool now operates on all components with
  1290 IsaMakefile, not just hardwired "logics".
  1291 
  1292 * Removed "compress" option from isabelle-process and isabelle usedir;
  1293 this is always enabled.
  1294 
  1295 * Discontinued support for Poly/ML 4.x versions.
  1296 
  1297 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1298 on a given logic image.  This requires the lighttpd webserver and is
  1299 currently supported on Linux only.
  1300 
  1301 
  1302 
  1303 New in Isabelle2009 (April 2009)
  1304 --------------------------------
  1305 
  1306 *** General ***
  1307 
  1308 * Simplified main Isabelle executables, with less surprises on
  1309 case-insensitive file-systems (such as Mac OS).
  1310 
  1311   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1312     "isatool."
  1313 
  1314   - The former "isabelle" alias for "isabelle-process" has been
  1315     removed (should rarely occur to regular users).
  1316 
  1317   - The former "isabelle-interface" and its alias "Isabelle" have been
  1318     removed (interfaces are now regular Isabelle tools).
  1319 
  1320 Within scripts and make files, the Isabelle environment variables
  1321 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1322 respectively.  (The latter are still available as legacy feature.)
  1323 
  1324 The old isabelle-interface wrapper could react in confusing ways if
  1325 the interface was uninstalled or changed otherwise.  Individual
  1326 interface tool configuration is now more explicit, see also the
  1327 Isabelle system manual.  In particular, Proof General is now available
  1328 via "isabelle emacs".
  1329 
  1330 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1331 purge installed copies of Isabelle executables and re-run "isabelle
  1332 install -p ...", or use symlinks.
  1333 
  1334 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1335 old ~/isabelle, which was slightly non-standard and apt to cause
  1336 surprises on case-insensitive file-systems (such as Mac OS).
  1337 
  1338 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1339 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1340 care is required when using older releases of Isabelle.  Note that
  1341 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1342 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1343 
  1344 * Proofs of fully specified statements are run in parallel on
  1345 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1346 a regular 4-core machine, if the initial heap space is made reasonably
  1347 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1348 
  1349 * The main reference manuals ("isar-ref", "implementation", and
  1350 "system") have been updated and extended.  Formally checked references
  1351 as hyperlinks are now available uniformly.
  1352 
  1353 
  1354 *** Pure ***
  1355 
  1356 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1357 respects.  The most important changes are listed below.  See the
  1358 Tutorial on Locales ("locales" manual) for details.
  1359 
  1360 - In locale expressions, instantiation replaces renaming.  Parameters
  1361 must be declared in a for clause.  To aid compatibility with previous
  1362 parameter inheritance, in locale declarations, parameters that are not
  1363 'touched' (instantiation position "_" or omitted) are implicitly added
  1364 with their syntax at the beginning of the for clause.
  1365 
  1366 - Syntax from abbreviations and definitions in locales is available in
  1367 locale expressions and context elements.  The latter is particularly
  1368 useful in locale declarations.
  1369 
  1370 - More flexible mechanisms to qualify names generated by locale
  1371 expressions.  Qualifiers (prefixes) may be specified in locale
  1372 expressions, and can be marked as mandatory (syntax: "name!:") or
  1373 optional (syntax "name?:").  The default depends for plain "name:"
  1374 depends on the situation where a locale expression is used: in
  1375 commands 'locale' and 'sublocale' prefixes are optional, in
  1376 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1377 implicit qualifiers derived from the parameter names of a locale are
  1378 no longer generated.
  1379 
  1380 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1381 instantiation clause in "interpretation" and "interpret" (square
  1382 brackets) is no longer available.  Use locale expressions.
  1383 
  1384 - When converting proof scripts, mandatory qualifiers in
  1385 'interpretation' and 'interpret' should be retained by default, even
  1386 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1387 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1388 in locale expressions range over a single locale instance only.
  1389 
  1390 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1391 In existing theorem specifications replace the includes element by the
  1392 respective context elements of the included locale, omitting those
  1393 that are already present in the theorem specification.  Multiple
  1394 assume elements of a locale should be replaced by a single one
  1395 involving the locale predicate.  In the proof body, declarations (most
  1396 notably theorems) may be regained by interpreting the respective
  1397 locales in the proof context as required (command "interpret").
  1398 
  1399 If using "includes" in replacement of a target solely because the
  1400 parameter types in the theorem are not as general as in the target,
  1401 consider declaring a new locale with additional type constraints on
  1402 the parameters (context element "constrains").
  1403 
  1404 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1405 
  1406 - Locale interpretation commands no longer attempt to simplify goal.
  1407 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1408 methods intro_locales and unfold_locales to clarify.
  1409 
  1410 - Locale interpretation commands no longer accept interpretation
  1411 attributes.  INCOMPATIBILITY.
  1412 
  1413 * Class declaration: so-called "base sort" must not be given in import
  1414 list any longer, but is inferred from the specification.  Particularly
  1415 in HOL, write
  1416 
  1417     class foo = ...
  1418 
  1419 instead of
  1420 
  1421     class foo = type + ...
  1422 
  1423 * Class target: global versions of theorems stemming do not carry a
  1424 parameter prefix any longer.  INCOMPATIBILITY.
  1425 
  1426 * Class 'instance' command no longer accepts attached definitions.
  1427 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1428 
  1429 * Recovered hiding of consts, which was accidentally broken in
  1430 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1431 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1432 
  1433 * Slightly more coherent Pure syntax, with updated documentation in
  1434 isar-ref manual.  Removed locales meta_term_syntax and
  1435 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1436 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1437 directly in regular applications.
  1438 
  1439 * There is a new syntactic category "float_const" for signed decimal
  1440 fractions (e.g. 123.45 or -123.45).
  1441 
  1442 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1443 interface with 'setup' command instead.
  1444 
  1445 * Command 'local_setup' is similar to 'setup', but operates on a local
  1446 theory context.
  1447 
  1448 * The 'axiomatization' command now only works within a global theory
  1449 context.  INCOMPATIBILITY.
  1450 
  1451 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1452 hypotheses.  Sorts required in the course of reasoning need to be
  1453 covered by the constraints in the initial statement, completed by the
  1454 type instance information of the background theory.  Non-trivial sort
  1455 hypotheses, which rarely occur in practice, may be specified via
  1456 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1457 
  1458   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1459 
  1460 The result contains an implicit sort hypotheses as before --
  1461 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1462 normalization.
  1463 
  1464 * Generalized Isar history, with support for linear undo, direct state
  1465 addressing etc.
  1466 
  1467 * Changed defaults for unify configuration options:
  1468 
  1469   unify_trace_bound = 50 (formerly 25)
  1470   unify_search_bound = 60 (formerly 30)
  1471 
  1472 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1473 
  1474   a) On theory merge, the last set of code equations for a particular
  1475      constant is taken (in accordance with the policy applied by other
  1476      parts of the code generator framework).
  1477 
  1478   b) Code equations stemming from explicit declarations (e.g. code
  1479      attribute) gain priority over default code equations stemming
  1480      from definition, primrec, fun etc.
  1481 
  1482 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1483 
  1484 * Unified theorem tables for both code generators.  Thus [code
  1485 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1486 
  1487 * Command 'find_consts' searches for constants based on type and name
  1488 patterns, e.g.
  1489 
  1490     find_consts "_ => bool"
  1491 
  1492 By default, matching is against subtypes, but it may be restricted to
  1493 the whole type.  Searching by name is possible.  Multiple queries are
  1494 conjunctive and queries may be negated by prefixing them with a
  1495 hyphen:
  1496 
  1497     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1498 
  1499 * New 'find_theorems' criterion "solves" matches theorems that
  1500 directly solve the current goal (modulo higher-order unification).
  1501 
  1502 * Auto solve feature for main theorem statements: whenever a new goal
  1503 is stated, "find_theorems solves" is called; any theorems that could
  1504 solve the lemma directly are listed as part of the goal state.
  1505 Cf. associated options in Proof General Isabelle settings menu,
  1506 enabled by default, with reasonable timeout for pathological cases of
  1507 higher-order unification.
  1508 
  1509 
  1510 *** Document preparation ***
  1511 
  1512 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1513 demanding keyword 'by' and supporting the full method expression
  1514 syntax just like the Isar command 'by'.
  1515 
  1516 
  1517 *** HOL ***
  1518 
  1519 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1520 points Main and Complex_Main remain as before.
  1521 
  1522 * Logic image HOL-Plain provides a minimal HOL with the most important
  1523 tools available (inductive, datatype, primrec, ...).  This facilitates
  1524 experimentation and tool development.  Note that user applications
  1525 (and library theories) should never refer to anything below theory
  1526 Main, as before.
  1527 
  1528 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1529 experimentation due to shorter build times.
  1530 
  1531 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1532 were previously part of former HOL-Complex.  Entry point Hyperreal
  1533 remains valid, but theories formerly using Complex_Main should now use
  1534 new entry point Hypercomplex.
  1535 
  1536 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1537 Posix processes.  Avoids potentially expensive forking of the ML
  1538 process.  New thread-based implementation also works on non-Unix
  1539 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1540 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1541 commands are covered in the isar-ref manual.
  1542 
  1543 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1544 sledgehammer without local ATP installation (Vampire etc.). Other
  1545 provers may be included via suitable ML wrappers, see also
  1546 src/HOL/ATP_Linkup.thy.
  1547 
  1548 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1549 menu.
  1550 
  1551 * The metis method no longer fails because the theorem is too trivial
  1552 (contains the empty clause).
  1553 
  1554 * The metis method now fails in the usual manner, rather than raising
  1555 an exception, if it determines that it cannot prove the theorem.
  1556 
  1557 * Method "coherent" implements a prover for coherent logic (see also
  1558 src/Tools/coherent.ML).
  1559 
  1560 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1561 "undefined" is the right choice to replace "arbitrary", though
  1562 logically there is no difference.  INCOMPATIBILITY.
  1563 
  1564 * Command "value" now integrates different evaluation mechanisms.  The
  1565 result of the first successful evaluation mechanism is printed.  In
  1566 square brackets a particular named evaluation mechanisms may be
  1567 specified (currently, [SML], [code] or [nbe]).  See further
  1568 src/HOL/ex/Eval_Examples.thy.
  1569 
  1570 * Normalization by evaluation now allows non-leftlinear equations.
  1571 Declare with attribute [code nbe].
  1572 
  1573 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1574 as the structured Isar versions "cases" and "induct", cf. the
  1575 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1576 are now presented as a list of individual projections
  1577 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1578 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1579 rare situations a different rule is selected --- notably nested tuple
  1580 elimination instead of former prod.exhaust: use explicit (case_tac t
  1581 rule: prod.exhaust) here.
  1582 
  1583 * Attributes "cases", "induct", "coinduct" support "del" option.
  1584 
  1585 * Removed fact "case_split_thm", which duplicates "case_split".
  1586 
  1587 * The option datatype has been moved to a new theory Option.  Renamed
  1588 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1589 
  1590 * New predicate "strict_mono" classifies strict functions on partial
  1591 orders.  With strict functions on linear orders, reasoning about
  1592 (in)equalities is facilitated by theorems "strict_mono_eq",
  1593 "strict_mono_less_eq" and "strict_mono_less".
  1594 
  1595 * Some set operations are now proper qualified constants with
  1596 authentic syntax.  INCOMPATIBILITY:
  1597 
  1598     op Int ~>   Set.Int
  1599     op Un ~>    Set.Un
  1600     INTER ~>    Set.INTER
  1601     UNION ~>    Set.UNION
  1602     Inter ~>    Set.Inter
  1603     Union ~>    Set.Union
  1604     {} ~>       Set.empty
  1605     UNIV ~>     Set.UNIV
  1606 
  1607 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1608 theory Set.
  1609 
  1610 * Auxiliary class "itself" has disappeared -- classes without any
  1611 parameter are treated as expected by the 'class' command.
  1612 
  1613 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1614 
  1615 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1616 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1617 
  1618 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1619 method "approximation".  It proves formulas on real values by using
  1620 interval arithmetic.  In the formulas are also the transcendental
  1621 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1622 allowed. For examples see
  1623 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1624 
  1625 * Theory "Reflection" now resides in HOL/Library.
  1626 
  1627 * Entry point to Word library now simply named "Word".
  1628 INCOMPATIBILITY.
  1629 
  1630 * Made source layout more coherent with logical distribution
  1631 structure:
  1632 
  1633     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1634     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1635     src/HOL/Library/GCD.thy ~> src/HOL/
  1636     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1637     src/HOL/Library/Parity.thy ~> src/HOL/
  1638     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1639     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1640     src/HOL/Real/Lubs.thy ~> src/HOL/
  1641     src/HOL/Real/PReal.thy ~> src/HOL/
  1642     src/HOL/Real/Rational.thy ~> src/HOL/
  1643     src/HOL/Real/RComplete.thy ~> src/HOL/
  1644     src/HOL/Real/RealDef.thy ~> src/HOL/
  1645     src/HOL/Real/RealPow.thy ~> src/HOL/
  1646     src/HOL/Real/Real.thy ~> src/HOL/
  1647     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1648     src/HOL/Complex/Complex.thy ~> src/HOL/
  1649     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1650     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1651     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1652     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1653     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1654     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1655     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1656     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1657     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1658     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1659     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1660     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1661     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1662     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1663     src/HOL/Real/Float ~> src/HOL/Library/
  1664     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1665     src/HOL/Real/RealVector.thy ~> src/HOL/
  1666 
  1667     src/HOL/arith_data.ML ~> src/HOL/Tools
  1668     src/HOL/hologic.ML ~> src/HOL/Tools
  1669     src/HOL/simpdata.ML ~> src/HOL/Tools
  1670     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1671     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1672     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1673     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1674     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1675     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1676     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1677 
  1678     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1679     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1680     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1681     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1682     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1683     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1684 
  1685 * If methods "eval" and "evaluation" encounter a structured proof
  1686 state with !!/==>, only the conclusion is evaluated to True (if
  1687 possible), avoiding strange error messages.
  1688 
  1689 * Method "sizechange" automates termination proofs using (a
  1690 modification of) the size-change principle.  Requires SAT solver.  See
  1691 src/HOL/ex/Termination.thy for examples.
  1692 
  1693 * Simplifier: simproc for let expressions now unfolds if bound
  1694 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1695 
  1696 * Method "arith": Linear arithmetic now ignores all inequalities when
  1697 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1698 
  1699 * New attribute "arith" for facts that should always be used
  1700 automatically by arithmetic. It is intended to be used locally in
  1701 proofs, e.g.
  1702 
  1703   assumes [arith]: "x > 0"
  1704 
  1705 Global usage is discouraged because of possible performance impact.
  1706 
  1707 * New classes "top" and "bot" with corresponding operations "top" and
  1708 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1709 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1710 
  1711 * Changed definition lemma "less_fun_def" in order to provide an
  1712 instance for preorders on functions; use lemma "less_le" instead.
  1713 INCOMPATIBILITY.
  1714 
  1715 * Theory Orderings: class "wellorder" moved here, with explicit
  1716 induction rule "less_induct" as assumption.  For instantiation of
  1717 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1718 INCOMPATIBILITY.
  1719 
  1720 * Theory Orderings: added class "preorder" as superclass of "order".
  1721 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1722 etc. slightly changed.  Some theorems named order_class.* now named
  1723 preorder_class.*.
  1724 
  1725 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1726 "diag" to "Id_on".
  1727 
  1728 * Theory Finite_Set: added a new fold combinator of type
  1729 
  1730   ('a => 'b => 'b) => 'b => 'a set => 'b
  1731 
  1732 Occasionally this is more convenient than the old fold combinator
  1733 which is now defined in terms of the new one and renamed to
  1734 fold_image.
  1735 
  1736 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1737 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1738 extended with further lemmas!).  At the moment both still exist but
  1739 the former will disappear at some point.
  1740 
  1741 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1742 class recpower.  Type-specific simp rules for various recpower types
  1743 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1744 
  1745 rat_power_0    -> power_0
  1746 rat_power_Suc  -> power_Suc
  1747 realpow_0      -> power_0
  1748 realpow_Suc    -> power_Suc
  1749 complexpow_0   -> power_0
  1750 complexpow_Suc -> power_Suc
  1751 power_poly_0   -> power_0
  1752 power_poly_Suc -> power_Suc
  1753 
  1754 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1755 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1756 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1757 of lemmas from Divides has been generalized from nat to class
  1758 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1759 renames resulting from duplicate elimination:
  1760 
  1761     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1762     zero_dvd_iff ~>         dvd_0_left_iff
  1763     dvd_0 ~>                dvd_0_right
  1764     DIVISION_BY_ZERO_DIV ~> div_by_0
  1765     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1766     mult_div ~>             div_mult_self2_is_id
  1767     mult_mod ~>             mod_mult_self2_is_0
  1768 
  1769 * Theory IntDiv: removed many lemmas that are instances of class-based
  1770 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1771 rename old lemmas as follows:
  1772 
  1773 dvd_diff               -> nat_dvd_diff
  1774 dvd_zminus_iff         -> dvd_minus_iff
  1775 mod_add1_eq            -> mod_add_eq
  1776 mod_mult1_eq           -> mod_mult_right_eq
  1777 mod_mult1_eq'          -> mod_mult_left_eq
  1778 mod_mult_distrib_mod   -> mod_mult_eq
  1779 nat_mod_add_left_eq    -> mod_add_left_eq
  1780 nat_mod_add_right_eq   -> mod_add_right_eq
  1781 nat_mod_div_trivial    -> mod_div_trivial
  1782 nat_mod_mod_trivial    -> mod_mod_trivial
  1783 zdiv_zadd_self1        -> div_add_self1
  1784 zdiv_zadd_self2        -> div_add_self2
  1785 zdiv_zmult_self1       -> div_mult_self2_is_id
  1786 zdiv_zmult_self2       -> div_mult_self1_is_id
  1787 zdvd_triv_left         -> dvd_triv_left
  1788 zdvd_triv_right        -> dvd_triv_right
  1789 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1790 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1791 zmod_zadd_left_eq      -> mod_add_left_eq
  1792 zmod_zadd_right_eq     -> mod_add_right_eq
  1793 zmod_zadd_self1        -> mod_add_self1
  1794 zmod_zadd_self2        -> mod_add_self2
  1795 zmod_zadd1_eq          -> mod_add_eq
  1796 zmod_zdiff1_eq         -> mod_diff_eq
  1797 zmod_zdvd_zmod         -> mod_mod_cancel
  1798 zmod_zmod_cancel       -> mod_mod_cancel
  1799 zmod_zmult_self1       -> mod_mult_self2_is_0
  1800 zmod_zmult_self2       -> mod_mult_self1_is_0
  1801 zmod_1                 -> mod_by_1
  1802 zdiv_1                 -> div_by_1
  1803 zdvd_abs1              -> abs_dvd_iff
  1804 zdvd_abs2              -> dvd_abs_iff
  1805 zdvd_refl              -> dvd_refl
  1806 zdvd_trans             -> dvd_trans
  1807 zdvd_zadd              -> dvd_add
  1808 zdvd_zdiff             -> dvd_diff
  1809 zdvd_zminus_iff        -> dvd_minus_iff
  1810 zdvd_zminus2_iff       -> minus_dvd_iff
  1811 zdvd_zmultD            -> dvd_mult_right
  1812 zdvd_zmultD2           -> dvd_mult_left
  1813 zdvd_zmult_mono        -> mult_dvd_mono
  1814 zdvd_0_right           -> dvd_0_right
  1815 zdvd_0_left            -> dvd_0_left_iff
  1816 zdvd_1_left            -> one_dvd
  1817 zminus_dvd_iff         -> minus_dvd_iff
  1818 
  1819 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1820 
  1821 * The real numbers offer decimal input syntax: 12.34 is translated
  1822 into 1234/10^2. This translation is not reversed upon output.
  1823 
  1824 * Theory Library/Polynomial defines an abstract type 'a poly of
  1825 univariate polynomials with coefficients of type 'a.  In addition to
  1826 the standard ring operations, it also supports div and mod.  Code
  1827 generation is also supported, using list-style constructors.
  1828 
  1829 * Theory Library/Inner_Product defines a class of real_inner for real
  1830 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1831 => real.  Class real_inner is a subclass of real_normed_vector from
  1832 theory RealVector.
  1833 
  1834 * Theory Library/Product_Vector provides instances for the product
  1835 type 'a * 'b of several classes from RealVector and Inner_Product.
  1836 Definitions of addition, subtraction, scalar multiplication, norms,
  1837 and inner products are included.
  1838 
  1839 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1840 addition to the field operations, numerals and case syntax are also
  1841 supported.
  1842 
  1843 * Theory Library/Diagonalize provides constructive version of Cantor's
  1844 first diagonalization argument.
  1845 
  1846 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1847 zlcm (for int); carried together from various gcd/lcm developements in
  1848 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1849 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1850 may recover tupled syntax as follows:
  1851 
  1852     hide (open) const gcd
  1853     abbreviation gcd where
  1854       "gcd == (%(a, b). GCD.gcd a b)"
  1855     notation (output)
  1856       GCD.gcd ("gcd '(_, _')")
  1857 
  1858 The same works for lcm, zgcd, zlcm.
  1859 
  1860 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1861 instantiations for algebraic structures.  Removed some duplicate
  1862 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1863 
  1864 * ML antiquotation @{code} takes a constant as argument and generates
  1865 corresponding code in background and inserts name of the corresponding
  1866 resulting ML value/function/datatype constructor binding in place.
  1867 All occurrences of @{code} with a single ML block are generated
  1868 simultaneously.  Provides a generic and safe interface for
  1869 instrumentalizing code generation.  See
  1870 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1871 In future you ought to refrain from ad-hoc compiling generated SML
  1872 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1873 cannot refer to constants for which user-defined serializations are
  1874 set.  Refer to the corresponding ML counterpart directly in that
  1875 cases.
  1876 
  1877 * Command 'rep_datatype': instead of theorem names the command now
  1878 takes a list of terms denoting the constructors of the type to be
  1879 represented as datatype.  The characteristic theorems have to be
  1880 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1881 have disappeared in favour of existing ones:
  1882 
  1883     unit_induct                 ~> unit.induct
  1884     prod_induct                 ~> prod.induct
  1885     sum_induct                  ~> sum.induct
  1886     Suc_Suc_eq                  ~> nat.inject
  1887     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1888 
  1889 
  1890 *** HOL-Algebra ***
  1891 
  1892 * New locales for orders and lattices where the equivalence relation
  1893 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1894 locales use a record structure with field eq for the equivalence.
  1895 
  1896 * New theory of factorial domains.
  1897 
  1898 * Units_l_inv and Units_r_inv are now simp rules by default.
  1899 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1900 and/or r_inv will now also require deletion of these lemmas.
  1901 
  1902 * Renamed the following theorems, INCOMPATIBILITY:
  1903 
  1904 UpperD ~> Upper_memD
  1905 LowerD ~> Lower_memD
  1906 least_carrier ~> least_closed
  1907 greatest_carrier ~> greatest_closed
  1908 greatest_Lower_above ~> greatest_Lower_below
  1909 one_zero ~> carrier_one_zero
  1910 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1911 
  1912 
  1913 *** HOL-Nominal ***
  1914 
  1915 * Nominal datatypes can now contain type-variables.
  1916 
  1917 * Commands 'nominal_inductive' and 'equivariance' work with local
  1918 theory targets.
  1919 
  1920 * Nominal primrec can now works with local theory targets and its
  1921 specification syntax now conforms to the general format as seen in
  1922 'inductive' etc.
  1923 
  1924 * Method "perm_simp" honours the standard simplifier attributes
  1925 (no_asm), (no_asm_use) etc.
  1926 
  1927 * The new predicate #* is defined like freshness, except that on the
  1928 left hand side can be a set or list of atoms.
  1929 
  1930 * Experimental command 'nominal_inductive2' derives strong induction
  1931 principles for inductive definitions.  In contrast to
  1932 'nominal_inductive', which can only deal with a fixed number of
  1933 binders, it can deal with arbitrary expressions standing for sets of
  1934 atoms to be avoided.  The only inductive definition we have at the
  1935 moment that needs this generalisation is the typing rule for Lets in
  1936 the algorithm W:
  1937 
  1938  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1939  -----------------------------------------------------------------
  1940          Gamma |- Let x be t1 in t2 : T2
  1941 
  1942 In this rule one wants to avoid all the binders that are introduced by
  1943 "close Gamma T1".  We are looking for other examples where this
  1944 feature might be useful.  Please let us know.
  1945 
  1946 
  1947 *** HOLCF ***
  1948 
  1949 * Reimplemented the simplification procedure for proving continuity
  1950 subgoals.  The new simproc is extensible; users can declare additional
  1951 continuity introduction rules with the attribute [cont2cont].
  1952 
  1953 * The continuity simproc now uses a different introduction rule for
  1954 solving continuity subgoals on terms with lambda abstractions.  In
  1955 some rare cases the new simproc may fail to solve subgoals that the
  1956 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1957 Potential INCOMPATIBILITY.
  1958 
  1959 * Command 'fixrec': specification syntax now conforms to the general
  1960 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1961 examples.  INCOMPATIBILITY.
  1962 
  1963 
  1964 *** ZF ***
  1965 
  1966 * Proof of Zorn's Lemma for partial orders.
  1967 
  1968 
  1969 *** ML ***
  1970 
  1971 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1972 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1973 depends on multithreading, so timouts will not work before Poly/ML
  1974 5.2.1!
  1975 
  1976 * High-level support for concurrent ML programming, see
  1977 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1978 particularly convenient to organize independent functional
  1979 computations.  The concept of "synchronized variables" provides a
  1980 higher-order interface for components with shared state, avoiding the
  1981 delicate details of mutexes and condition variables.  (Requires
  1982 Poly/ML 5.2.1 or later.)
  1983 
  1984 * ML bindings produced via Isar commands are stored within the Isar
  1985 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1986 become thread-safe and work with undo as expected (concerning
  1987 top-level bindings, not side-effects on global references).
  1988 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1989 compiler at runtime; really global bindings need to be given outside a
  1990 theory.  (Requires Poly/ML 5.2 or later.)
  1991 
  1992 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1993 context.  Top-level ML bindings are stored within the proof context in
  1994 a purely sequential fashion, disregarding the nested proof structure.
  1995 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1996 proof.  (Requires Poly/ML 5.2 or later.)
  1997 
  1998 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1999 and Method.setup, as well as Isar commands 'attribute_setup' and
  2000 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2001 existing code accordingly, or use plain 'setup' together with old
  2002 Method.add_method.
  2003 
  2004 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2005 to 'a -> thm, while results are always tagged with an authentic oracle
  2006 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2007 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2008 accordingly.  Note that extra performance may be gained by producing
  2009 the cterm carefully, avoiding slow Thm.cterm_of.
  2010 
  2011 * Simplified interface for defining document antiquotations via
  2012 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2013 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2014 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2015 examples.
  2016 
  2017 * More systematic treatment of long names, abstract name bindings, and
  2018 name space operations.  Basic operations on qualified names have been
  2019 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2020 Long_Name.append.  Old type bstring has been mostly replaced by
  2021 abstract type binding (see structure Binding), which supports precise
  2022 qualification by packages and local theory targets, as well as proper
  2023 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2024 bstring values into Binding.name, or better pass through abstract
  2025 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2026 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2027 
  2028 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2029 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2030 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2031 
  2032 * Disposed old type and term read functions (Sign.read_def_typ,
  2033 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2034 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2035 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2036 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2037 resort for legacy applications.
  2038 
  2039 * Disposed old declarations, tactics, tactic combinators that refer to
  2040 the simpset or claset of an implicit theory (such as Addsimps,
  2041 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2042 embedded ML text, or local_simpset_of with a proper context passed as
  2043 explicit runtime argument.
  2044 
  2045 * Rules and tactics that read instantiations (read_instantiate,
  2046 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2047 context, which is required for parsing and type-checking.  Moreover,
  2048 the variables are specified as plain indexnames, not string encodings
  2049 thereof.  INCOMPATIBILITY.
  2050 
  2051 * Generic Toplevel.add_hook interface allows to analyze the result of
  2052 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2053 for theorem dependency output of transactions resulting in a new
  2054 theory state.
  2055 
  2056 * ML antiquotations: block-structured compilation context indicated by
  2057 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2058 
  2059   @{binding name}                         - basic name binding
  2060   @{let ?pat = term}                      - term abbreviation (HO matching)
  2061   @{note name = fact}                     - fact abbreviation
  2062   @{thm fact}                             - singleton fact (with attributes)
  2063   @{thms fact}                            - general fact (with attributes)
  2064   @{lemma prop by method}                 - singleton goal
  2065   @{lemma prop by meth1 meth2}            - singleton goal
  2066   @{lemma prop1 ... propN by method}      - general goal
  2067   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2068   @{lemma (open) ...}                     - open derivation
  2069 
  2070 
  2071 *** System ***
  2072 
  2073 * The Isabelle "emacs" tool provides a specific interface to invoke
  2074 Proof General / Emacs, with more explicit failure if that is not
  2075 installed (the old isabelle-interface script silently falls back on
  2076 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2077 installation location of the Proof General distribution.
  2078 
  2079 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2080 the Isabelle process into a JVM/Scala application.  See
  2081 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2082 process wrapper has been discontinued.)
  2083 
  2084 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2085 
  2086 * Various status messages (with exact source position information) are
  2087 emitted, if proper markup print mode is enabled.  This allows
  2088 user-interface components to provide detailed feedback on internal
  2089 prover operations.
  2090 
  2091 
  2092 
  2093 New in Isabelle2008 (June 2008)
  2094 -------------------------------
  2095 
  2096 *** General ***
  2097 
  2098 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2099 and updated, with formally checked references as hyperlinks.
  2100 
  2101 * Theory loader: use_thy (and similar operations) no longer set the
  2102 implicit ML context, which was occasionally hard to predict and in
  2103 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2104 provides a proper context already.
  2105 
  2106 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2107 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2108 'use' within a theory file will do the job.
  2109 
  2110 * Name space merge now observes canonical order, i.e. the second space
  2111 is inserted into the first one, while existing entries in the first
  2112 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2113 swap theory imports.
  2114 
  2115 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2116 INCOMPATIBILITY in identifier syntax etc.
  2117 
  2118 * Outer syntax: string tokens no longer admit escaped white space,
  2119 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2120 white space without escapes.
  2121 
  2122 * Outer syntax: string tokens may contain arbitrary character codes
  2123 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2124 "foo_bar".
  2125 
  2126 
  2127 *** Pure ***
  2128 
  2129 * Context-dependent token translations.  Default setup reverts locally
  2130 fixed variables, and adds hilite markup for undeclared frees.
  2131 
  2132 * Unused theorems can be found using the new command 'unused_thms'.
  2133 There are three ways of invoking it:
  2134 
  2135 (1) unused_thms
  2136      Only finds unused theorems in the current theory.
  2137 
  2138 (2) unused_thms thy_1 ... thy_n -
  2139      Finds unused theorems in the current theory and all of its ancestors,
  2140      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2141 
  2142 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2143      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2144      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2145      their ancestors.
  2146 
  2147 In order to increase the readability of the list produced by
  2148 unused_thms, theorems that have been created by a particular instance
  2149 of a theory command such as 'inductive' or 'function' are considered
  2150 to belong to the same "group", meaning that if at least one theorem in
  2151 this group is used, the other theorems in the same group are no longer
  2152 reported as unused.  Moreover, if all theorems in the group are
  2153 unused, only one theorem in the group is displayed.
  2154 
  2155 Note that proof objects have to be switched on in order for
  2156 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2157 usually the case when using Proof General with the default settings).
  2158 
  2159 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2160 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2161 duplicate fact bindings, or even accidental fact duplications.  Note
  2162 that tools may maintain dynamically scoped facts systematically, using
  2163 PureThy.add_thms_dynamic.
  2164 
  2165 * Command 'hide' now allows to hide from "fact" name space as well.
  2166 
  2167 * Eliminated destructive theorem database, simpset, claset, and
  2168 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2169 update of theories within ML code.
  2170 
  2171 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2172 INCOMPATIBILITY, object-logics depending on former Pure require
  2173 additional setup PureThy.old_appl_syntax_setup; object-logics
  2174 depending on former CPure need to refer to Pure.
  2175 
  2176 * Commands 'use' and 'ML' are now purely functional, operating on
  2177 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2178 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2179 INCOMPATIBILITY.
  2180 
  2181 * Command 'setup': discontinued implicit version with ML reference.
  2182 
  2183 * Instantiation target allows for simultaneous specification of class
  2184 instance operations together with an instantiation proof.
  2185 Type-checking phase allows to refer to class operations uniformly.
  2186 See src/HOL/Complex/Complex.thy for an Isar example and
  2187 src/HOL/Library/Eval.thy for an ML example.
  2188 
  2189 * Indexing of literal facts: be more serious about including only
  2190 facts from the visible specification/proof context, but not the
  2191 background context (locale etc.).  Affects `prop` notation and method
  2192 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2193 situations.
  2194 
  2195 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2196 "(open)" option, which used to expose internal bound variables to the
  2197 proof text.
  2198 
  2199 * Isar statements: removed obsolete case "rule_context".
  2200 INCOMPATIBILITY, better use explicit fixes/assumes.
  2201 
  2202 * Locale proofs: default proof step now includes 'unfold_locales';
  2203 hence 'proof' without argument may be used to unfold locale
  2204 predicates.
  2205 
  2206 
  2207 *** Document preparation ***
  2208 
  2209 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2210 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2211 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2212 spot); renamed link color from "darkblue" to "linkcolor" (default
  2213 value unchanged, can be redefined via \definecolor); no longer sets
  2214 "a4paper" option (unnecessary or even intrusive).
  2215 
  2216 * Antiquotation @{lemma A method} proves proposition A by the given
  2217 method (either a method name or a method name plus (optional) method
  2218 arguments in parentheses) and prints A just like @{prop A}.
  2219 
  2220 
  2221 *** HOL ***
  2222 
  2223 * New primrec package.  Specification syntax conforms in style to
  2224 definition/function/....  No separate induction rule is provided.  The
  2225 "primrec" command distinguishes old-style and new-style specifications
  2226 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2227 When adjusting theories, beware: constants stemming from new-style
  2228 primrec specifications have authentic syntax.
  2229 
  2230 * Metis prover is now an order of magnitude faster, and also works
  2231 with multithreading.
  2232 
  2233 * Metis: the maximum number of clauses that can be produced from a
  2234 theorem is now given by the attribute max_clauses.  Theorems that
  2235 exceed this number are ignored, with a warning printed.
  2236 
  2237 * Sledgehammer no longer produces structured proofs by default. To
  2238 enable, declare [[sledgehammer_full = true]].  Attributes
  2239 reconstruction_modulus, reconstruction_sorts renamed
  2240 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2241 
  2242 * Method "induct_scheme" derives user-specified induction rules
  2243 from well-founded induction and completeness of patterns. This factors
  2244 out some operations that are done internally by the function package
  2245 and makes them available separately.  See
  2246 src/HOL/ex/Induction_Scheme.thy for examples.
  2247 
  2248 * More flexible generation of measure functions for termination
  2249 proofs: Measure functions can be declared by proving a rule of the
  2250 form "is_measure f" and giving it the [measure_function] attribute.
  2251 The "is_measure" predicate is logically meaningless (always true), and
  2252 just guides the heuristic.  To find suitable measure functions, the
  2253 termination prover sets up the goal "is_measure ?f" of the appropriate
  2254 type and generates all solutions by prolog-style backwards proof using
  2255 the declared rules.
  2256 
  2257 This setup also deals with rules like 
  2258 
  2259   "is_measure f ==> is_measure (list_size f)"
  2260 
  2261 which accommodates nested datatypes that recurse through lists.
  2262 Similar rules are predeclared for products and option types.
  2263 
  2264 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2265 
  2266   INCOMPATIBILITIES:
  2267 
  2268   - Definitions of overloaded constants on sets have to be replaced by
  2269     definitions on => and bool.
  2270 
  2271   - Some definitions of overloaded operators on sets can now be proved
  2272     using the definitions of the operators on => and bool.  Therefore,
  2273     the following theorems have been renamed:
  2274 
  2275       subset_def   -> subset_eq
  2276       psubset_def  -> psubset_eq
  2277       set_diff_def -> set_diff_eq
  2278       Compl_def    -> Compl_eq
  2279       Sup_set_def  -> Sup_set_eq
  2280       Inf_set_def  -> Inf_set_eq
  2281       sup_set_def  -> sup_set_eq
  2282       inf_set_def  -> inf_set_eq
  2283 
  2284   - Due to the incompleteness of the HO unification algorithm, some
  2285     rules such as subst may require manual instantiation, if some of
  2286     the unknowns in the rule is a set.
  2287 
  2288   - Higher order unification and forward proofs:
  2289     The proof pattern
  2290 
  2291       have "P (S::'a set)" <...>
  2292       then have "EX S. P S" ..
  2293 
  2294     no longer works (due to the incompleteness of the HO unification
  2295     algorithm) and must be replaced by the pattern
  2296 
  2297       have "EX S. P S"
  2298       proof
  2299         show "P S" <...>
  2300       qed
  2301 
  2302   - Calculational reasoning with subst (or similar rules):
  2303     The proof pattern
  2304 
  2305       have "P (S::'a set)" <...>
  2306       also have "S = T" <...>
  2307       finally have "P T" .
  2308 
  2309     no longer works (for similar reasons as the previous example) and
  2310     must be replaced by something like
  2311 
  2312       have "P (S::'a set)" <...>
  2313       moreover have "S = T" <...>
  2314       ultimately have "P T" by simp
  2315 
  2316   - Tactics or packages written in ML code:
  2317     Code performing pattern matching on types via
  2318 
  2319       Type ("set", [T]) => ...
  2320 
  2321     must be rewritten. Moreover, functions like strip_type or
  2322     binder_types no longer return the right value when applied to a
  2323     type of the form
  2324 
  2325       T1 => ... => Tn => U => bool
  2326 
  2327     rather than
  2328 
  2329       T1 => ... => Tn => U set
  2330 
  2331 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2332 Wellfounded_Relations to theory Wellfounded.
  2333 
  2334 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2335 
  2336 * Class finite no longer treats UNIV as class parameter.  Use class
  2337 enum from theory Library/Enum instead to achieve a similar effect.
  2338 INCOMPATIBILITY.
  2339 
  2340 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2341 and "Cons".  INCOMPATIBILITY.
  2342 
  2343 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2344 Potential INCOMPATIBILITY.
  2345 
  2346 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2347 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2348 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2349 
  2350 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2351 the same name in theory Orderings:
  2352 
  2353   less_trans
  2354   less_linear
  2355   le_imp_less_or_eq
  2356   le_less_trans
  2357   less_le_trans
  2358   less_not_sym
  2359   less_asym
  2360 
  2361 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2362 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2363 and different variable names.
  2364 
  2365 * Library/Option_ord.thy: Canonical order on option type.
  2366 
  2367 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2368 finite maps.
  2369 
  2370 * Library/Countable.thy: Type class for countable types.
  2371 
  2372 * Theory Int: The representation of numerals has changed.  The infix
  2373 operator BIT and the bit datatype with constructors B0 and B1 have
  2374 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2375 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2376 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2377 accordingly.
  2378 
  2379 * Theory Nat: definition of <= and < on natural numbers no longer
  2380 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2381 le_def and less_def have disappeared.  Consider lemmas not_less
  2382 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2383 
  2384 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2385 (whose purpose mainly is for various fold_set functionals) have been
  2386 abandoned in favor of the existing algebraic classes
  2387 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2388 lower_semilattice (resp. upper_semilattice) and linorder.
  2389 INCOMPATIBILITY.
  2390 
  2391 * Theory Transitive_Closure: induct and cases rules now declare proper
  2392 case_names ("base" and "step").  INCOMPATIBILITY.
  2393 
  2394 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2395 lattices.  The form set-specific version is available as
  2396 Inductive.lfp_ordinal_induct_set.
  2397 
  2398 * Renamed theorems "power.simps" to "power_int.simps".
  2399 INCOMPATIBILITY.
  2400 
  2401 * Class semiring_div provides basic abstract properties of semirings
  2402 with division and modulo operations.  Subsumes former class dvd_mod.
  2403 
  2404 * Merged theories IntDef, Numeral and IntArith into unified theory
  2405 Int.  INCOMPATIBILITY.
  2406 
  2407 * Theory Library/Code_Index: type "index" now represents natural
  2408 numbers rather than integers.  INCOMPATIBILITY.
  2409 
  2410 * New class "uminus" with operation "uminus" (split of from class
  2411 "minus" which now only has operation "minus", binary).
  2412 INCOMPATIBILITY.
  2413 
  2414 * Constants "card", "internal_split", "option_map" now with authentic
  2415 syntax.  INCOMPATIBILITY.
  2416 
  2417 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2418 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2419 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2420 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2421 Sup_set_def, le_def, less_def, option_map_def now with object
  2422 equality.  INCOMPATIBILITY.
  2423 
  2424 * Records. Removed K_record, and replaced it by pure lambda term
  2425 %x. c. The simplifier setup is now more robust against eta expansion.
  2426 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2427 
  2428 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2429 
  2430 * Library/ListVector: new theory of arithmetic vector operations.
  2431 
  2432 * Library/Order_Relation: new theory of various orderings as sets of
  2433 pairs.  Defines preorders, partial orders, linear orders and
  2434 well-orders on sets and on types.
  2435 
  2436 
  2437 *** ZF ***
  2438 
  2439 * Renamed some theories to allow to loading both ZF and HOL in the
  2440 same session:
  2441 
  2442   Datatype  -> Datatype_ZF
  2443   Inductive -> Inductive_ZF
  2444   Int       -> Int_ZF
  2445   IntDiv    -> IntDiv_ZF
  2446   Nat       -> Nat_ZF
  2447   List      -> List_ZF
  2448   Main      -> Main_ZF
  2449 
  2450 INCOMPATIBILITY: ZF theories that import individual theories below
  2451 Main might need to be adapted.  Regular theory Main is still
  2452 available, as trivial extension of Main_ZF.
  2453 
  2454 
  2455 *** ML ***
  2456 
  2457 * ML within Isar: antiquotation @{const name} or @{const
  2458 name(typargs)} produces statically-checked Const term.
  2459 
  2460 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2461 (of the same name).  Removed obsolete print command.
  2462 
  2463 * Removed obsolete "use_legacy_bindings" function.
  2464 
  2465 * The ``print mode'' is now a thread-local value derived from a global
  2466 template (the former print_mode reference), thus access becomes
  2467 non-critical.  The global print_mode reference is for session
  2468 management only; user-code should use print_mode_value,
  2469 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2470 
  2471 * Functions system/system_out provide a robust way to invoke external
  2472 shell commands, with propagation of interrupts (requires Poly/ML
  2473 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2474 
  2475 
  2476 *** System ***
  2477 
  2478 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2479 in accordance with Proof General 3.7, which prefers GNU emacs.
  2480 
  2481 * isatool tty runs Isabelle process with plain tty interaction;
  2482 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2483 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2484 
  2485 * isatool browser now works with Cygwin as well, using general
  2486 "javapath" function defined in Isabelle process environment.
  2487 
  2488 * YXML notation provides a simple and efficient alternative to
  2489 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2490 isatool yxml as described in the Isabelle system manual.
  2491 
  2492 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2493 provides general wrapper for managing an Isabelle process in a robust
  2494 fashion, with ``cooked'' output from stdin/stderr.
  2495 
  2496 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2497 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2498 
  2499 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2500 way of changing the user's settings is via
  2501 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2502 script.
  2503 
  2504 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2505 cores of the underlying machine, which is a good starting point for
  2506 optimal performance tuning.  The corresponding usedir option -M allows
  2507 "max" as an alias for "0".  WARNING: does not work on certain versions
  2508 of Mac OS (with Poly/ML 5.1).
  2509 
  2510 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2511 adverse effect of Isabelle flooding interactive front-ends (notably
  2512 ProofGeneral / XEmacs).
  2513 
  2514 
  2515 
  2516 New in Isabelle2007 (November 2007)
  2517 -----------------------------------
  2518 
  2519 *** General ***
  2520 
  2521 * More uniform information about legacy features, notably a
  2522 warning/error of "Legacy feature: ...", depending on the state of the
  2523 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2524 legacy features will disappear eventually.
  2525 
  2526 * Theory syntax: the header format ``theory A = B + C:'' has been
  2527 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2528 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2529 
  2530 * Theory syntax: the old non-Isar theory file format has been
  2531 discontinued altogether.  Note that ML proof scripts may still be used
  2532 with Isar theories; migration is usually quite simple with the ML
  2533 function use_legacy_bindings.  INCOMPATIBILITY.
  2534 
  2535 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2536 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2537 quotes.
  2538 
  2539 * Theory loader: be more serious about observing the static theory
  2540 header specifications (including optional directories), but not the
  2541 accidental file locations of previously successful loads.  The strict
  2542 update policy of former update_thy is now already performed by
  2543 use_thy, so the former has been removed; use_thys updates several
  2544 theories simultaneously, just as 'imports' within a theory header
  2545 specification, but without merging the results.  Potential
  2546 INCOMPATIBILITY: may need to refine theory headers and commands
  2547 ROOT.ML which depend on load order.
  2548 
  2549 * Theory loader: optional support for content-based file
  2550 identification, instead of the traditional scheme of full physical
  2551 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2552 (cf. the system manual).  The new scheme allows to work with
  2553 non-finished theories in persistent session images, such that source
  2554 files may be moved later on without requiring reloads.
  2555 
  2556 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2557 file (with the same base name as the theory) are considered a legacy
  2558 feature, which will disappear eventually. Even now, the theory loader
  2559 no longer maintains dependencies on such files.
  2560 
  2561 * Syntax: the scope for resolving ambiguities via type-inference is
  2562 now limited to individual terms, instead of whole simultaneous
  2563 specifications as before. This greatly reduces the complexity of the
  2564 syntax module and improves flexibility by separating parsing and
  2565 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2566 'fixes' etc.) are required in rare situations.
  2567 
  2568 * Syntax: constants introduced by new-style packages ('definition',
  2569 'abbreviation' etc.) are passed through the syntax module in
  2570 ``authentic mode''. This means that associated mixfix annotations
  2571 really stick to such constants, independently of potential name space
  2572 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2573 trees are represented slightly differently, may need to adapt syntax
  2574 translations accordingly. Use CONST marker in 'translations' and
  2575 @{const_syntax} antiquotation in 'parse_translation' etc.
  2576 
  2577 * Legacy goal package: reduced interface to the bare minimum required
  2578 to keep existing proof scripts running.  Most other user-level
  2579 functions are now part of the OldGoals structure, which is *not* open
  2580 by default (consider isatool expandshort before open OldGoals).
  2581 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2582 these tend to cause confusion about the actual goal (!) context being
  2583 used here, which is not necessarily the same as the_context().
  2584 
  2585 * Command 'find_theorems': supports "*" wild-card in "name:"
  2586 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2587 support a specific search form (see ProofGeneral/CHANGES).
  2588 
  2589 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2590 by default, which means that "prems" (and also "fixed variables") are
  2591 suppressed from proof state output.  Note that the ProofGeneral
  2592 settings mechanism allows to change and save options persistently, but
  2593 older versions of Isabelle will fail to start up if a negative prems
  2594 limit is imposed.
  2595 
  2596 * Local theory targets may be specified by non-nested blocks of
  2597 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2598 contain definitions, theorems etc., including any derived mechanism
  2599 that has been implemented on top of these primitives.  This concept
  2600 generalizes the existing ``theorem (in ...)'' towards more versatility
  2601 and scalability.
  2602 
  2603 * Proof General interface: proper undo of final 'end' command;
  2604 discontinued Isabelle/classic mode (ML proof scripts).
  2605 
  2606 
  2607 *** Document preparation ***
  2608 
  2609 * Added antiquotation @{theory name} which prints the given name,
  2610 after checking that it refers to a valid ancestor theory in the
  2611 current context.
  2612 
  2613 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2614 check the given source text as ML type/structure, printing verbatim.
  2615 
  2616 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2617 "c args == rhs" given in the current context.  (Any number of
  2618 arguments may be given on the LHS.)
  2619 
  2620 
  2621 *** Pure ***
  2622 
  2623 * The 'class' package offers a combination of axclass and locale to
  2624 achieve Haskell-like type classes in Isabelle.  Definitions and
  2625 theorems within a class context produce both relative results (with
  2626 implicit parameters according to the locale context), and polymorphic
  2627 constants with qualified polymorphism (according to the class
  2628 context).  Within the body context of a 'class' target, a separate
  2629 syntax layer ("user space type system") takes care of converting
  2630 between global polymorphic consts and internal locale representation.
  2631 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2632 "isatool doc classes" provides a tutorial.
  2633 
  2634 * Generic code generator framework allows to generate executable
  2635 code for ML and Haskell (including Isabelle classes).  A short usage
  2636 sketch:
  2637 
  2638     internal compilation:
  2639         export_code <list of constants (term syntax)> in SML
  2640     writing SML code to a file:
  2641         export_code <list of constants (term syntax)> in SML <filename>
  2642     writing OCaml code to a file:
  2643         export_code <list of constants (term syntax)> in OCaml <filename>
  2644     writing Haskell code to a bunch of files:
  2645         export_code <list of constants (term syntax)> in Haskell <filename>
  2646 
  2647     evaluating closed propositions to True/False using code generation:
  2648         method ``eval''
  2649 
  2650 Reasonable default setup of framework in HOL.
  2651 
  2652 Theorem attributs for selecting and transforming function equations theorems:
  2653 
  2654     [code fun]:        select a theorem as function equation for a specific constant
  2655     [code fun del]:    deselect a theorem as function equation for a specific constant
  2656     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2657     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2658 
  2659 User-defined serializations (target in {SML, OCaml, Haskell}):
  2660 
  2661     code_const <and-list of constants (term syntax)>
  2662       {(target) <and-list of const target syntax>}+
  2663 
  2664     code_type <and-list of type constructors>
  2665       {(target) <and-list of type target syntax>}+
  2666 
  2667     code_instance <and-list of instances>
  2668       {(target)}+
  2669         where instance ::= <type constructor> :: <class>
  2670 
  2671     code_class <and_list of classes>
  2672       {(target) <and-list of class target syntax>}+
  2673         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2674 
  2675 code_instance and code_class only are effective to target Haskell.
  2676 
  2677 For example usage see src/HOL/ex/Codegenerator.thy and
  2678 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2679 generation from Isabelle/HOL theories is available via "isatool doc
  2680 codegen".
  2681 
  2682 * Code generator: consts in 'consts_code' Isar commands are now
  2683 referred to by usual term syntax (including optional type
  2684 annotations).
  2685 
  2686 * Command 'no_translations' removes translation rules from theory
  2687 syntax.
  2688 
  2689 * Overloaded definitions are now actually checked for acyclic
  2690 dependencies.  The overloading scheme is slightly more general than
  2691 that of Haskell98, although Isabelle does not demand an exact
  2692 correspondence to type class and instance declarations.
  2693 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2694 exotic versions of overloading -- at the discretion of the user!
  2695 
  2696 Polymorphic constants are represented via type arguments, i.e. the
  2697 instantiation that matches an instance against the most general
  2698 declaration given in the signature.  For example, with the declaration
  2699 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2700 as c(nat).  Overloading is essentially simultaneous structural
  2701 recursion over such type arguments.  Incomplete specification patterns
  2702 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2703 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2704 Command 'print_theory' outputs the normalized system of recursive
  2705 equations, see section "definitions".
  2706 
  2707 * Configuration options are maintained within the theory or proof
  2708 context (with name and type bool/int/string), providing a very simple
  2709 interface to a poor-man's version of general context data.  Tools may
  2710 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2711 these values using Config.get etc.  Users may change options via an
  2712 associated attribute of the same name.  This form of context
  2713 declaration works particularly well with commands 'declare' or
  2714 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2715 very easy to avoid global references, which would not observe Isar
  2716 toplevel undo/redo and fail to work with multithreading.
  2717 
  2718 Various global ML references of Pure and HOL have been turned into
  2719 configuration options:
  2720 
  2721   Unify.search_bound		unify_search_bound
  2722   Unify.trace_bound		unify_trace_bound
  2723   Unify.trace_simp		unify_trace_simp
  2724   Unify.trace_types		unify_trace_types
  2725   Simplifier.simp_depth_limit	simp_depth_limit
  2726   Blast.depth_limit		blast_depth_limit
  2727   DatatypeProp.dtK		datatype_distinctness_limit
  2728   fast_arith_neq_limit  	fast_arith_neq_limit
  2729   fast_arith_split_limit	fast_arith_split_limit
  2730 
  2731 * Named collections of theorems may be easily installed as context
  2732 data using the functor NamedThmsFun (see also
  2733 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2734 attributes; there is also a toplevel print command.  This facility is
  2735 just a common case of general context data, which is the preferred way
  2736 for anything more complex than just a list of facts in canonical
  2737 order.
  2738 
  2739 * Isar: command 'declaration' augments a local theory by generic
  2740 declaration functions written in ML.  This enables arbitrary content
  2741 being added to the context, depending on a morphism that tells the
  2742 difference of the original declaration context wrt. the application
  2743 context encountered later on.
  2744 
  2745 * Isar: proper interfaces for simplification procedures.  Command
  2746 'simproc_setup' declares named simprocs (with match patterns, and body
  2747 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2748 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2749 
  2750 * Isar: an extra pair of brackets around attribute declarations
  2751 abbreviates a theorem reference involving an internal dummy fact,
  2752 which will be ignored later --- only the effect of the attribute on
  2753 the background context will persist.  This form of in-place
  2754 declarations is particularly useful with commands like 'declare' and
  2755 'using', for example ``have A using [[simproc a]] by simp''.
  2756 
  2757 * Isar: method "assumption" (and implicit closing of subproofs) now
  2758 takes simple non-atomic goal assumptions into account: after applying
  2759 an assumption as a rule the resulting subgoals are solved by atomic
  2760 assumption steps.  This is particularly useful to finish 'obtain'
  2761 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2762 without referring to the original premise "!!x. P x ==> thesis" in the
  2763 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2764 more permissive.
  2765 
  2766 * Isar: implicit use of prems from the Isar proof context is
  2767 considered a legacy feature.  Common applications like ``have A .''
  2768 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2769 referencing facts explicitly here improves readability and
  2770 maintainability of proof texts.
  2771 
  2772 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2773 the obtained context from the course of reasoning!  For example:
  2774 
  2775   assume "EX x y. A x & B y"   -- "any previous fact"
  2776   then guess x and y by clarify
  2777 
  2778 This technique is potentially adventurous, depending on the facts and
  2779 proof tools being involved here.
  2780 
  2781 * Isar: known facts from the proof context may be specified as literal
  2782 propositions, using ASCII back-quote syntax.  This works wherever
  2783 named facts used to be allowed so far, in proof commands, proof
  2784 methods, attributes etc.  Literal facts are retrieved from the context
  2785 according to unification of type and term parameters.  For example,
  2786 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2787 theorems in the current context, then these are valid literal facts:
  2788 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2789 
  2790 There is also a proof method "fact" which does the same composition
  2791 for explicit goal states, e.g. the following proof texts coincide with
  2792 certain special cases of literal facts:
  2793 
  2794   have "A" by fact                 ==  note `A`
  2795   have "A ==> B" by fact           ==  note `A ==> B`
  2796   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2797   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2798 
  2799 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2800 outer syntax.  Thus symbolic identifiers may be used without
  2801 additional white space in declarations like this: ``assume *: A''.
  2802 
  2803 * Isar: 'print_facts' prints all local facts of the current context,
  2804 both named and unnamed ones.
  2805 
  2806 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2807 
  2808   def x == "t" and y == "u"
  2809 
  2810 * Isar: added command 'unfolding', which is structurally similar to
  2811 'using', but affects both the goal state and facts by unfolding given
  2812 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2813 'unfolded' attribute may be replaced by first-class proof text.
  2814 
  2815 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2816 and command 'unfolding' now all support object-level equalities
  2817 (potentially conditional).  The underlying notion of rewrite rule is
  2818 analogous to the 'rule_format' attribute, but *not* that of the
  2819 Simplifier (which is usually more generous).
  2820 
  2821 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2822 premises of a theorem by n. Useful in conjunction with drule.
  2823 
  2824 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2825 method expression within a sandbox consisting of the first N
  2826 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2827 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2828 simplifies all new goals that emerge from applying rule foo to the
  2829 originally first one.
  2830 
  2831 * Isar: schematic goals are no longer restricted to higher-order
  2832 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2833 expected.
  2834 
  2835 * Isar: the conclusion of a long theorem statement is now either
  2836 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2837 (essentially a disjunction of cases with local parameters and
  2838 assumptions).  The latter allows to express general elimination rules
  2839 adequately; in this notation common elimination rules look like this:
  2840 
  2841   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2842     assumes "EX x. P x"
  2843     obtains x where "P x"
  2844 
  2845   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2846     assumes "A & B"
  2847     obtains A and B
  2848 
  2849   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2850     assumes "A | B"
  2851     obtains
  2852       A
  2853     | B
  2854 
  2855 The subsequent classical rules even refer to the formal "thesis"
  2856 explicitly:
  2857 
  2858   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2859     obtains "~ thesis"
  2860 
  2861   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2862     obtains "thesis ==> something"
  2863 
  2864 The actual proof of an 'obtains' statement is analogous to that of the
  2865 Isar proof element 'obtain', only that there may be several cases.
  2866 Optional case names may be specified in parentheses; these will be
  2867 available both in the present proof and as annotations in the
  2868 resulting rule, for later use with the 'cases' method (cf. attribute
  2869 case_names).
  2870 
  2871 * Isar: the assumptions of a long theorem statement are available as
  2872 "assms" fact in the proof context.  This is more appropriate than the
  2873 (historical) "prems", which refers to all assumptions of the current
  2874 context, including those from the target locale, proof body etc.
  2875 
  2876 * Isar: 'print_statement' prints theorems from the current theory or
  2877 proof context in long statement form, according to the syntax of a
  2878 top-level lemma.
  2879 
  2880 * Isar: 'obtain' takes an optional case name for the local context
  2881 introduction rule (default "that").
  2882 
  2883 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2884 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2885 to occur.
  2886 
  2887 * Pure: syntax "CONST name" produces a fully internalized constant
  2888 according to the current context.  This is particularly useful for
  2889 syntax translations that should refer to internal constant
  2890 representations independently of name spaces.
  2891 
  2892 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2893 instead of "FOO ". This allows multiple binder declarations to coexist
  2894 in the same context.  INCOMPATIBILITY.
  2895 
  2896 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2897 primitive that also works in a locale context (both for constants and
  2898 fixed variables). Type declaration and internal syntactic representation
  2899 of given constants retrieved from the context. Likewise, the
  2900 'no_notation' command allows to remove given syntax annotations from the
  2901 current context.
  2902 
  2903 * Isar/locales: new derived specification elements 'axiomatization',
  2904 'definition', 'abbreviation', which support type-inference, admit
  2905 object-level specifications (equality, equivalence).  See also the
  2906 isar-ref manual.  Examples:
  2907 
  2908   axiomatization
  2909     eq  (infix "===" 50) where
  2910     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2911 
  2912   definition "f x y = x + y + 1"
  2913   definition g where "g x = f x x"
  2914 
  2915   abbreviation
  2916     neq  (infix "=!=" 50) where
  2917     "x =!= y == ~ (x === y)"
  2918 
  2919 These specifications may be also used in a locale context.  Then the
  2920 constants being introduced depend on certain fixed parameters, and the
  2921 constant name is qualified by the locale base name.  An internal
  2922 abbreviation takes care for convenient input and output, making the
  2923 parameters implicit and using the original short name.  See also
  2924 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2925 entities from a monomorphic theory.
  2926 
  2927 Presently, abbreviations are only available 'in' a target locale, but
  2928 not inherited by general import expressions.  Also note that
  2929 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2930 'translations' in common applications.  The "no_abbrevs" print mode
  2931 prevents folding of abbreviations in term output.
  2932 
  2933 Concrete syntax is attached to specified constants in internal form,
  2934 independently of name spaces.  The parse tree representation is
  2935 slightly different -- use 'notation' instead of raw 'syntax', and
  2936 'translations' with explicit "CONST" markup to accommodate this.
  2937 
  2938 * Pure/Isar: unified syntax for new-style specification mechanisms
  2939 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2940 full type inference and dummy patterns ("_").  For example:
  2941 
  2942   definition "K x _ = x"
  2943 
  2944   inductive conj for A B
  2945   where "A ==> B ==> conj A B"
  2946 
  2947 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2948 the current context.  Print mode "no_abbrevs" prevents inversion of
  2949 abbreviations on output.
  2950 
  2951 * Isar/locales: improved parameter handling: use of locales "var" and
  2952 "struct" no longer necessary; - parameter renamings are no longer
  2953 required to be injective.  For example, this allows to define
  2954 endomorphisms as locale endom = homom mult mult h.
  2955 
  2956 * Isar/locales: changed the way locales with predicates are defined.
  2957 Instead of accumulating the specification, the imported expression is
  2958 now an interpretation.  INCOMPATIBILITY: different normal form of
  2959 locale expressions.  In particular, in interpretations of locales with
  2960 predicates, goals repesenting already interpreted fragments are not
  2961 removed automatically.  Use methods `intro_locales' and
  2962 `unfold_locales'; see below.
  2963 
  2964 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2965 provide backward reasoning on locales predicates.  The methods are
  2966 aware of interpretations and discharge corresponding goals.
  2967 `intro_locales' is less aggressive then `unfold_locales' and does not
  2968 unfold predicates to assumptions.
  2969 
  2970 * Isar/locales: the order in which locale fragments are accumulated
  2971 has changed.  This enables to override declarations from fragments due
  2972 to interpretations -- for example, unwanted simp rules.
  2973 
  2974 * Isar/locales: interpretation in theories and proof contexts has been
  2975 extended.  One may now specify (and prove) equations, which are
  2976 unfolded in interpreted theorems.  This is useful for replacing
  2977 defined concepts (constants depending on locale parameters) by
  2978 concepts already existing in the target context.  Example:
  2979 
  2980   interpretation partial_order ["op <= :: [int, int] => bool"]
  2981     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2982 
  2983 Typically, the constant `partial_order.less' is created by a
  2984 definition specification element in the context of locale
  2985 partial_order.
  2986 
  2987 * Method "induct": improved internal context management to support
  2988 local fixes and defines on-the-fly. Thus explicit meta-level
  2989 connectives !!  and ==> are rarely required anymore in inductive goals
  2990 (using object-logic connectives for this purpose has been long
  2991 obsolete anyway). Common proof patterns are explained in
  2992 src/HOL/Induct/Common_Patterns.thy, see also
  2993 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2994 examples.
  2995 
  2996 * Method "induct": improved handling of simultaneous goals. Instead of
  2997 introducing object-level conjunction, the statement is now split into
  2998 several conclusions, while the corresponding symbolic cases are nested
  2999 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3000 see src/HOL/Induct/Common_Patterns.thy, for example.
  3001 
  3002 * Method "induct": mutual induction rules are now specified as a list
  3003 of rule sharing the same induction cases. HOL packages usually provide
  3004 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3005 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3006 mutual induction rules differently, i.e. like this:
  3007 
  3008   (induct rule: foo_bar.inducts)
  3009   (induct set: foo bar)
  3010   (induct pred: foo bar)
  3011   (induct type: foo bar)
  3012 
  3013 The ML function ProjectRule.projections turns old-style rules into the
  3014 new format.
  3015 
  3016 * Method "coinduct": dual of induction, see
  3017 src/HOL/Library/Coinductive_List.thy for various examples.
  3018 
  3019 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3020 considered a legacy feature.
  3021 
  3022 * Attribute "symmetric" produces result with standardized schematic
  3023 variables (index 0).  Potential INCOMPATIBILITY.
  3024 
  3025 * Simplifier: by default the simplifier trace only shows top level
  3026 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3027 default. Thus there is less danger of being flooded by the trace. The
  3028 trace indicates where parts have been suppressed.
  3029   
  3030 * Provers/classical: removed obsolete classical version of elim_format
  3031 attribute; classical elim/dest rules are now treated uniformly when
  3032 manipulating the claset.
  3033 
  3034 * Provers/classical: stricter checks to ensure that supplied intro,
  3035 dest and elim rules are well-formed; dest and elim rules must have at
  3036 least one premise.
  3037 
  3038 * Provers/classical: attributes dest/elim/intro take an optional
  3039 weight argument for the rule (just as the Pure versions).  Weights are
  3040 ignored by automated tools, but determine the search order of single
  3041 rule steps.
  3042 
  3043 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3044 where the body does not mention the bound variable.  Note that dummy
  3045 patterns implicitly depend on their context of bounds, which makes
  3046 "{_. _}" match any set comprehension as expected.  Potential
  3047 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3048 constant "_idtdummy" in the binding position.
  3049 
  3050 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3051 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3052 for example "A -> B" => "Pi A (%_. B)".
  3053 
  3054 * Pure: 'class_deps' command visualizes the subclass relation, using
  3055 the graph browser tool.
  3056 
  3057 * Pure: 'print_theory' now suppresses certain internal declarations by
  3058 default; use '!' option for full details.
  3059 
  3060 
  3061 *** HOL ***
  3062 
  3063 * Method "metis" proves goals by applying the Metis general-purpose
  3064 resolution prover (see also http://gilith.com/software/metis/).
  3065 Examples are in the directory MetisExamples.  WARNING: the
  3066 Isabelle/HOL-Metis integration does not yet work properly with
  3067 multi-threading.
  3068   
  3069 * Command 'sledgehammer' invokes external automatic theorem provers as
  3070 background processes.  It generates calls to the "metis" method if
  3071 successful. These can be pasted into the proof.  Users do not have to
  3072 wait for the automatic provers to return.  WARNING: does not really
  3073 work with multi-threading.
  3074 
  3075 * New "auto_quickcheck" feature tests outermost goal statements for
  3076 potential counter-examples.  Controlled by ML references
  3077 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3078 5000 milliseconds).  Fails silently if statements is outside of
  3079 executable fragment, or any other codgenerator problem occurs.
  3080 
  3081 * New constant "undefined" with axiom "undefined x = undefined".
  3082 
  3083 * Added class "HOL.eq", allowing for code generation with polymorphic
  3084 equality.
  3085 
  3086 * Some renaming of class constants due to canonical name prefixing in
  3087 the new 'class' package:
  3088 
  3089     HOL.abs ~> HOL.abs_class.abs
  3090     HOL.divide ~> HOL.divide_class.divide
  3091     0 ~> HOL.zero_class.zero
  3092     1 ~> HOL.one_class.one
  3093     op + ~> HOL.plus_class.plus
  3094     op - ~> HOL.minus_class.minus
  3095     uminus ~> HOL.minus_class.uminus
  3096     op * ~> HOL.times_class.times
  3097     op < ~> HOL.ord_class.less
  3098     op <= > HOL.ord_class.less_eq
  3099     Nat.power ~> Power.power_class.power
  3100     Nat.size ~> Nat.size_class.size
  3101     Numeral.number_of ~> Numeral.number_class.number_of
  3102     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3103     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3104     Orderings.min ~> Orderings.ord_class.min
  3105     Orderings.max ~> Orderings.ord_class.max
  3106     Divides.op div ~> Divides.div_class.div
  3107     Divides.op mod ~> Divides.div_class.mod
  3108     Divides.op dvd ~> Divides.div_class.dvd
  3109 
  3110 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3111 
  3112 a) User-defined constants using any of the names "plus", "minus",
  3113 "times", "less" or "less_eq". The standard syntax translations for
  3114 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3115 names.
  3116 
  3117 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3118 INCOMPATIBILITY: use more specific names.
  3119 
  3120 c) Permutative equations (e.g. "a + b = b + a")
  3121 Since the change of names also changes the order of terms, permutative
  3122 rewrite rules may get applied in a different order. Experience shows
  3123 that this is rarely the case (only two adaptions in the whole Isabelle
  3124 distribution).  INCOMPATIBILITY: rewrite proofs
  3125 
  3126 d) ML code directly refering to constant names
  3127 This in general only affects hand-written proof tactics, simprocs and
  3128 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3129 Consider using @{const_name} antiquotation.
  3130 
  3131 * New class "default" with associated constant "default".
  3132 
  3133 * Function "sgn" is now overloaded and available on int, real, complex
  3134 (and other numeric types), using class "sgn".  Two possible defs of
  3135 sgn are given as equational assumptions in the classes sgn_if and
  3136 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3137 INCOMPATIBILITY.
  3138 
  3139 * Locale "partial_order" now unified with class "order" (cf. theory
  3140 Orderings), added parameter "less".  INCOMPATIBILITY.
  3141 
  3142 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3143 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3144 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3145 
  3146 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3147 changed order of proof goals in instance proofs.
  3148 
  3149 * The transitivity reasoner for partial and linear orders is set up
  3150 for classes "order" and "linorder".  Instances of the reasoner are available
  3151 in all contexts importing or interpreting the corresponding locales.
  3152 Method "order" invokes the reasoner separately; the reasoner
  3153 is also integrated with the Simplifier as a solver.  Diagnostic
  3154 command 'print_orders' shows the available instances of the reasoner
  3155 in the current context.
  3156 
  3157 * Localized monotonicity predicate in theory "Orderings"; integrated
  3158 lemmas max_of_mono and min_of_mono with this predicate.
  3159 INCOMPATIBILITY.
  3160 
  3161 * Formulation of theorem "dense" changed slightly due to integration
  3162 with new class dense_linear_order.
  3163 
  3164 * Uniform lattice theory development in HOL.
  3165 
  3166     constants "meet" and "join" now named "inf" and "sup"
  3167     constant "Meet" now named "Inf"
  3168 
  3169     classes "meet_semilorder" and "join_semilorder" now named
  3170       "lower_semilattice" and "upper_semilattice"
  3171     class "lorder" now named "lattice"
  3172     class "comp_lat" now named "complete_lattice"
  3173 
  3174     Instantiation of lattice classes allows explicit definitions
  3175     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3176 
  3177   INCOMPATIBILITY.  Theorem renames:
  3178 
  3179     meet_left_le            ~> inf_le1
  3180     meet_right_le           ~> inf_le2
  3181     join_left_le            ~> sup_ge1
  3182     join_right_le           ~> sup_ge2
  3183     meet_join_le            ~> inf_sup_ord
  3184     le_meetI                ~> le_infI
  3185     join_leI                ~> le_supI
  3186     le_meet                 ~> le_inf_iff
  3187     le_join                 ~> ge_sup_conv
  3188     meet_idempotent         ~> inf_idem
  3189     join_idempotent         ~> sup_idem
  3190     meet_comm               ~> inf_commute
  3191     join_comm               ~> sup_commute
  3192     meet_leI1               ~> le_infI1
  3193     meet_leI2               ~> le_infI2
  3194     le_joinI1               ~> le_supI1
  3195     le_joinI2               ~> le_supI2
  3196     meet_assoc              ~> inf_assoc
  3197     join_assoc              ~> sup_assoc
  3198     meet_left_comm          ~> inf_left_commute
  3199     meet_left_idempotent    ~> inf_left_idem
  3200     join_left_comm          ~> sup_left_commute
  3201     join_left_idempotent    ~> sup_left_idem
  3202     meet_aci                ~> inf_aci
  3203     join_aci                ~> sup_aci
  3204     le_def_meet             ~> le_iff_inf
  3205     le_def_join             ~> le_iff_sup
  3206     join_absorp2            ~> sup_absorb2
  3207     join_absorp1            ~> sup_absorb1
  3208     meet_absorp1            ~> inf_absorb1
  3209     meet_absorp2            ~> inf_absorb2
  3210     meet_join_absorp        ~> inf_sup_absorb
  3211     join_meet_absorp        ~> sup_inf_absorb
  3212     distrib_join_le         ~> distrib_sup_le
  3213     distrib_meet_le         ~> distrib_inf_le
  3214 
  3215     add_meet_distrib_left   ~> add_inf_distrib_left
  3216     add_join_distrib_left   ~> add_sup_distrib_left
  3217     is_join_neg_meet        ~> is_join_neg_inf
  3218     is_meet_neg_join        ~> is_meet_neg_sup
  3219     add_meet_distrib_right  ~> add_inf_distrib_right
  3220     add_join_distrib_right  ~> add_sup_distrib_right
  3221     add_meet_join_distribs  ~> add_sup_inf_distribs
  3222     join_eq_neg_meet        ~> sup_eq_neg_inf
  3223     meet_eq_neg_join        ~> inf_eq_neg_sup
  3224     add_eq_meet_join        ~> add_eq_inf_sup
  3225     meet_0_imp_0            ~> inf_0_imp_0
  3226     join_0_imp_0            ~> sup_0_imp_0
  3227     meet_0_eq_0             ~> inf_0_eq_0
  3228     join_0_eq_0             ~> sup_0_eq_0
  3229     neg_meet_eq_join        ~> neg_inf_eq_sup
  3230     neg_join_eq_meet        ~> neg_sup_eq_inf
  3231     join_eq_if              ~> sup_eq_if
  3232 
  3233     mono_meet               ~> mono_inf
  3234     mono_join               ~> mono_sup
  3235     meet_bool_eq            ~> inf_bool_eq
  3236     join_bool_eq            ~> sup_bool_eq
  3237     meet_fun_eq             ~> inf_fun_eq
  3238     join_fun_eq             ~> sup_fun_eq
  3239     meet_set_eq             ~> inf_set_eq
  3240     join_set_eq             ~> sup_set_eq
  3241     meet1_iff               ~> inf1_iff
  3242     meet2_iff               ~> inf2_iff
  3243     meet1I                  ~> inf1I
  3244     meet2I                  ~> inf2I
  3245     meet1D1                 ~> inf1D1
  3246     meet2D1                 ~> inf2D1
  3247     meet1D2                 ~> inf1D2
  3248     meet2D2                 ~> inf2D2
  3249     meet1E                  ~> inf1E
  3250     meet2E                  ~> inf2E
  3251     join1_iff               ~> sup1_iff
  3252     join2_iff               ~> sup2_iff
  3253     join1I1                 ~> sup1I1
  3254     join2I1                 ~> sup2I1
  3255     join1I1                 ~> sup1I1
  3256     join2I2                 ~> sup1I2
  3257     join1CI                 ~> sup1CI
  3258     join2CI                 ~> sup2CI
  3259     join1E                  ~> sup1E
  3260     join2E                  ~> sup2E
  3261 
  3262     is_meet_Meet            ~> is_meet_Inf
  3263     Meet_bool_def           ~> Inf_bool_def
  3264     Meet_fun_def            ~> Inf_fun_def
  3265     Meet_greatest           ~> Inf_greatest
  3266     Meet_lower              ~> Inf_lower
  3267     Meet_set_def            ~> Inf_set_def
  3268 
  3269     Sup_def                 ~> Sup_Inf
  3270     Sup_bool_eq             ~> Sup_bool_def
  3271     Sup_fun_eq              ~> Sup_fun_def
  3272     Sup_set_eq              ~> Sup_set_def
  3273 
  3274     listsp_meetI            ~> listsp_infI
  3275     listsp_meet_eq          ~> listsp_inf_eq
  3276 
  3277     meet_min                ~> inf_min
  3278     join_max                ~> sup_max
  3279 
  3280 * Added syntactic class "size"; overloaded constant "size" now has
  3281 type "'a::size ==> bool"
  3282 
  3283 * Internal reorganisation of `size' of datatypes: size theorems
  3284 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3285 simplification rules by default!); theorems "prod.size" now named
  3286 "*.size".
  3287 
  3288 * Class "div" now inherits from class "times" rather than "type".
  3289 INCOMPATIBILITY.
  3290 
  3291 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3292 Linorder etc.  have disappeared; operations defined in terms of
  3293 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3294 
  3295 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3296 
  3297 * HOL-Word: New extensive library and type for generic, fixed size
  3298 machine words, with arithemtic, bit-wise, shifting and rotating
  3299 operations, reflection into int, nat, and bool lists, automation for
  3300 linear arithmetic (by automatic reflection into nat or int), including
  3301 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3302 arithmetic type classes, supporting automatic simplification of
  3303 numerals on all operations.
  3304 
  3305 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3306 
  3307 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3308 
  3309 * Code generator library theories:
  3310   - Code_Integer represents HOL integers by big integer literals in target
  3311     languages.
  3312   - Code_Char represents HOL characters by character literals in target
  3313     languages.
  3314   - Code_Char_chr like Code_Char, but also offers treatment of character
  3315     codes; includes Code_Integer.
  3316   - Executable_Set allows to generate code for finite sets using lists.
  3317   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3318     denominator).
  3319   - Executable_Real implements a subset of real numbers, namly those
  3320     representable by rational numbers.
  3321   - Efficient_Nat implements natural numbers by integers, which in general will
  3322     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3323     includes Code_Integer.
  3324   - Code_Index provides an additional datatype index which is mapped to
  3325     target-language built-in integers.
  3326   - Code_Message provides an additional datatype message_string which is isomorphic to
  3327     strings; messages are mapped to target-language strings.
  3328 
  3329 * New package for inductive predicates
  3330 
  3331   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3332 
  3333     inductive
  3334       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3335       for z_1 :: U_1 and ... and z_n :: U_m
  3336     where
  3337       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3338     | ...
  3339 
  3340   with full support for type-inference, rather than
  3341 
  3342     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3343 
  3344     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3345     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3346 
  3347     inductive "s z_1 ... z_m"
  3348     intros
  3349       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3350       ...
  3351 
  3352   For backward compatibility, there is a wrapper allowing inductive
  3353   sets to be defined with the new package via
  3354 
  3355     inductive_set
  3356       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3357       for z_1 :: U_1 and ... and z_n :: U_m
  3358     where
  3359       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3360     | ...
  3361 
  3362   or
  3363 
  3364     inductive_set
  3365       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3366       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3367       for z_1 :: U_1 and ... and z_n :: U_m
  3368     where
  3369       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3370     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3371     | ...
  3372 
  3373   if the additional syntax "p ..." is required.
  3374 
  3375   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3376   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3377 
  3378   INCOMPATIBILITIES:
  3379 
  3380   - Since declaration and definition of inductive sets or predicates
  3381     is no longer separated, abbreviations involving the newly
  3382     introduced sets or predicates must be specified together with the
  3383     introduction rules after the 'where' keyword (see above), rather
  3384     than before the actual inductive definition.
  3385 
  3386   - The variables in induction and elimination rules are now
  3387     quantified in the order of their occurrence in the introduction
  3388     rules, rather than in alphabetical order. Since this may break
  3389     some proofs, these proofs either have to be repaired, e.g. by
  3390     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3391     statements of the form
  3392 
  3393       case (rule_i a_i_1 ... a_i_{k_i})
  3394 
  3395     or the old order of quantification has to be restored by explicitly adding
  3396     meta-level quantifiers in the introduction rules, i.e.
  3397 
  3398       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3399 
  3400   - The format of the elimination rules is now
  3401 
  3402       p z_1 ... z_m x_1 ... x_n ==>
  3403         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3404         ==> ... ==> P
  3405 
  3406     for predicates and
  3407 
  3408       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3409         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3410         ==> ... ==> P
  3411 
  3412     for sets rather than
  3413 
  3414       x : s z_1 ... z_m ==>
  3415         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3416         ==> ... ==> P
  3417 
  3418     This may require terms in goals to be expanded to n-tuples
  3419     (e.g. using case_tac or simplification with the split_paired_all
  3420     rule) before the above elimination rule is applicable.
  3421 
  3422   - The elimination or case analysis rules for (mutually) inductive
  3423     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3424     list of rules "p_1_..._p_k.elims" is no longer available.
  3425 
  3426 * New package "function"/"fun" for general recursive functions,
  3427 supporting mutual and nested recursion, definitions in local contexts,
  3428 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3429 for small examples, and the separate tutorial on the function
  3430 package. The old recdef "package" is still available as before, but
  3431 users are encouraged to use the new package.
  3432 
  3433 * Method "lexicographic_order" automatically synthesizes termination
  3434 relations as lexicographic combinations of size measures. 
  3435 
  3436 * Case-expressions allow arbitrary constructor-patterns (including
  3437 "_") and take their order into account, like in functional
  3438 programming.  Internally, this is translated into nested
  3439 case-expressions; missing cases are added and mapped to the predefined
  3440 constant "undefined". In complicated cases printing may no longer show
  3441 the original input but the internal form. Lambda-abstractions allow
  3442 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3443 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3444 variable.
  3445 
  3446 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3447 is an abbreviation for "of_nat :: nat => int". The simplification
  3448 rules for "of_nat" have been changed to work like "int" did
  3449 previously.  Potential INCOMPATIBILITY:
  3450   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3451   - of_nat_diff and of_nat_mult are no longer default simp rules
  3452 
  3453 * Method "algebra" solves polynomial equations over (semi)rings using
  3454 Groebner bases. The (semi)ring structure is defined by locales and the
  3455 tool setup depends on that generic context. Installing the method for
  3456 a specific type involves instantiating the locale and possibly adding
  3457 declarations for computation on the coefficients.  The method is
  3458 already instantiated for natural numbers and for the axiomatic class
  3459 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3460 CALCULEMUS 2007 for the general principles underlying this
  3461 architecture of context-aware proof-tools.
  3462 
  3463 * Method "ferrack" implements quantifier elimination over
  3464 special-purpose dense linear orders using locales (analogous to
  3465 "algebra"). The method is already installed for class
  3466 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3467 rat, etc.
  3468 
  3469 * Former constant "List.op @" now named "List.append".  Use ML
  3470 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3471 circumvent possible incompatibilities when working on ML level.
  3472 
  3473 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3474 
  3475 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3476 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3477 
  3478 * New syntax for Haskell-like list comprehension (input only), eg.
  3479 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3480 
  3481 * The special syntax for function "filter" has changed from [x :
  3482 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3483 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3484 
  3485 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3486 defined on nat only, as an abbreviation for [a..<Suc b]
  3487 INCOMPATIBILITY.
  3488 
  3489 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3490 
  3491 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3492 
  3493 * New lemma collection field_simps (an extension of ring_simps) for
  3494 manipulating (in)equations involving division. Multiplies with all
  3495 denominators that can be proved to be non-zero (in equations) or
  3496 positive/negative (in inequations).
  3497 
  3498 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3499 have been improved and renamed to ring_simps, group_simps and
  3500 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3501 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3502 
  3503 * Theory Library/Commutative_Ring: switched from recdef to function
  3504 package; constants add, mul, pow now curried.  Infix syntax for
  3505 algebraic operations.
  3506 
  3507 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3508 INCOMPATIBILITY.
  3509 
  3510 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3511 INCOMPATIBILITY.
  3512 
  3513 * HOL/records: generalised field-update to take a function on the
  3514 field rather than the new value: r(|A := x|) is translated to A_update
  3515 (K x) r The K-combinator that is internally used is called K_record.
  3516 INCOMPATIBILITY: Usage of the plain update functions has to be
  3517 adapted.
  3518  
  3519 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3520 * x = 0, which are required for a semiring.  Richer structures do not
  3521 inherit from semiring_0 anymore, because this property is a theorem
  3522 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3523 there is more to prove, but this is mostly trivial.
  3524 
  3525 * Class "recpower" is generalized to arbitrary monoids, not just
  3526 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3527 commutativity or semiring properties additionally.
  3528 
  3529 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3530 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3531 better use 'abbreviation'.
  3532 
  3533 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3534 
  3535 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3536 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3537 significant changes for setting up numeral syntax for types:
  3538   - New constants Numeral.pred and Numeral.succ instead
  3539       of former Numeral.bin_pred and Numeral.bin_succ.
  3540   - Use integer operations instead of bin_add, bin_mult and so on.
  3541   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3542   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3543 
  3544 See src/HOL/Integ/IntArith.thy for an example setup.
  3545 
  3546 * Command 'normal_form' computes the normal form of a term that may
  3547 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3548 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3549 heavy-duty computations because the functions are compiled to ML
  3550 first.  Correspondingly, a method "normalization" is provided.  See
  3551 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3552 
  3553 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3554 25 like -->); output depends on the "iff" print_mode, the default is
  3555 "A = B" (with priority 50).
  3556 
  3557 * Relations less (<) and less_eq (<=) are also available on type bool.
  3558 Modified syntax to disallow nesting without explicit parentheses,
  3559 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3560 INCOMPATIBILITY.
  3561 
  3562 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3563 
  3564 * Relation composition operator "op O" now has precedence 75 and binds
  3565 stronger than union and intersection. INCOMPATIBILITY.
  3566 
  3567 * The old set interval syntax "{m..n(}" (and relatives) has been
  3568 removed.  Use "{m..<n}" (and relatives) instead.
  3569 
  3570 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3571 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3572 ``declare [[simproc del: neq]]''.
  3573 
  3574 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3575 True/False.
  3576 
  3577 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3578 
  3579 * Theorem setsum_mult renamed to setsum_right_distrib.
  3580 
  3581 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3582 ``rule'' method.
  3583 
  3584 * Reimplemented methods "sat" and "satx", with several improvements:
  3585 goals no longer need to be stated as "<prems> ==> False", equivalences
  3586 (i.e. "=" on type bool) are handled, variable names of the form
  3587 "lit_<n>" are no longer reserved, significant speedup.
  3588 
  3589 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3590 zChaff is still supported as well.
  3591 
  3592 * 'inductive' and 'datatype': provide projections of mutual rules,
  3593 bundled as foo_bar.inducts;
  3594 
  3595 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3596 Library.
  3597 
  3598 * Library: moved theory Accessible_Part to main HOL.
  3599 
  3600 * Library: added theory Coinductive_List of potentially infinite lists
  3601 as greatest fixed-point.
  3602 
  3603 * Library: added theory AssocList which implements (finite) maps as
  3604 association lists.
  3605 
  3606 * Method "evaluation" solves goals (i.e. a boolean expression)
  3607 efficiently by compiling it to ML.  The goal is "proved" (via an
  3608 oracle) if it evaluates to True.
  3609 
  3610 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3611 also when invoked by the simplifier.  This results in the Simplifier
  3612 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3613 Configuration option fast_arith_split_limit=0 recovers the old
  3614 behavior.
  3615 
  3616 * Support for hex (0x20) and binary (0b1001) numerals.
  3617 
  3618 * New method: reify eqs (t), where eqs are equations for an
  3619 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3620 parameter, computes a term s::'b and a list xs::'a list and proves the
  3621 theorem I xs s = t. This is also known as reification or quoting. The
  3622 resulting theorem is applied to the subgoal to substitute t with I xs
  3623 s.  If t is omitted, the subgoal itself is reified.
  3624 
  3625 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3626 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3627 where f is supposed to be a computable function (in the sense of code
  3628 generattion). The method uses reify to compute s and xs as above then
  3629 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3630 r and finally gets the theorem t = r, which is again applied to the
  3631 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3632 
  3633 * Reflection: Automatic reification now handels binding, an example is
  3634 available in src/HOL/ex/ReflectionEx.thy
  3635 
  3636 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3637 command 'statespace' that is similar to 'record', but introduces an
  3638 abstract specification based on the locale infrastructure instead of
  3639 HOL types.  This leads to extra flexibility in composing state spaces,
  3640 in particular multiple inheritance and renaming of components.
  3641 
  3642 
  3643 *** HOL-Complex ***
  3644 
  3645 * Hyperreal: Functions root and sqrt are now defined on negative real
  3646 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3647 Nonnegativity side conditions have been removed from many lemmas, so
  3648 that more subgoals may now be solved by simplification; potential
  3649 INCOMPATIBILITY.
  3650 
  3651 * Real: new type classes formalize real normed vector spaces and
  3652 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3653 and norm :: 'a => real.
  3654 
  3655 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3656 reals into other types. The overloaded constant Reals :: 'a set is now
  3657 defined as range of_real; potential INCOMPATIBILITY.
  3658 
  3659 * Real: proper support for ML code generation, including 'quickcheck'.
  3660 Reals are implemented as arbitrary precision rationals.
  3661 
  3662 * Hyperreal: Several constants that previously worked only for the
  3663 reals have been generalized, so they now work over arbitrary vector
  3664 spaces. Type annotations may need to be added in some cases; potential
  3665 INCOMPATIBILITY.
  3666 
  3667   Infinitesimal  :: ('a::real_normed_vector) star set
  3668   HFinite        :: ('a::real_normed_vector) star set
  3669   HInfinite      :: ('a::real_normed_vector) star set
  3670   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3671   monad          :: ('a::real_normed_vector) star => 'a star set
  3672   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3673   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3674   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3675   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3676   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3677   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3678   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3679   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3680   sgn            :: 'a::real_normed_vector => 'a
  3681   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3682 
  3683 * Complex: Some complex-specific constants are now abbreviations for
  3684 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3685 hnorm.  Other constants have been entirely removed in favor of the
  3686 polymorphic versions (INCOMPATIBILITY):
  3687 
  3688   approx        <-- capprox
  3689   HFinite       <-- CFinite
  3690   HInfinite     <-- CInfinite
  3691   Infinitesimal <-- CInfinitesimal
  3692   monad         <-- cmonad
  3693   galaxy        <-- cgalaxy
  3694   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3695   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3696   (ns)deriv     <-- (ns)cderiv
  3697 
  3698 
  3699 *** HOL-Algebra ***
  3700 
  3701 * Formalisation of ideals and the quotient construction over rings.
  3702 
  3703 * Order and lattice theory no longer based on records.
  3704 INCOMPATIBILITY.
  3705 
  3706 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3707 greatest_closed.  INCOMPATIBILITY.
  3708 
  3709 * Method algebra is now set up via an attribute.  For examples see
  3710 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3711 of algebraic structures.
  3712 
  3713 * Renamed theory CRing to Ring.
  3714 
  3715 
  3716 *** HOL-Nominal ***
  3717 
  3718 * Substantial, yet incomplete support for nominal datatypes (binding
  3719 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3720 src/HOL/Nominal/Examples.  Prospective users should consult
  3721 http://isabelle.in.tum.de/nominal/
  3722 
  3723 
  3724 *** ML ***
  3725 
  3726 * ML basics: just one true type int, which coincides with IntInf.int
  3727 (even on SML/NJ).
  3728 
  3729 * ML within Isar: antiquotations allow to embed statically-checked
  3730 formal entities in the source, referring to the context available at
  3731 compile-time.  For example:
  3732 
  3733 ML {* @{sort "{zero,one}"} *}
  3734 ML {* @{typ "'a => 'b"} *}
  3735 ML {* @{term "%x. x"} *}
  3736 ML {* @{prop "x == y"} *}
  3737 ML {* @{ctyp "'a => 'b"} *}
  3738 ML {* @{cterm "%x. x"} *}
  3739 ML {* @{cprop "x == y"} *}
  3740 ML {* @{thm asm_rl} *}
  3741 ML {* @{thms asm_rl} *}
  3742 ML {* @{type_name c} *}
  3743 ML {* @{type_syntax c} *}
  3744 ML {* @{const_name c} *}
  3745 ML {* @{const_syntax c} *}
  3746 ML {* @{context} *}
  3747 ML {* @{theory} *}
  3748 ML {* @{theory Pure} *}
  3749 ML {* @{theory_ref} *}
  3750 ML {* @{theory_ref Pure} *}
  3751 ML {* @{simpset} *}
  3752 ML {* @{claset} *}
  3753 ML {* @{clasimpset} *}
  3754 
  3755 The same works for sources being ``used'' within an Isar context.
  3756 
  3757 * ML in Isar: improved error reporting; extra verbosity with
  3758 ML_Context.trace enabled.
  3759 
  3760 * Pure/General/table.ML: the join operations now works via exceptions
  3761 DUP/SAME instead of type option. This is simpler in simple cases, and
  3762 admits slightly more efficient complex applications.
  3763 
  3764 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3765 use Context.generic instead of just theory.
  3766 
  3767 * Pure: datatype Context.generic joins theory/Proof.context and
  3768 provides some facilities for code that works in either kind of
  3769 context, notably GenericDataFun for uniform theory and proof data.
  3770 
  3771 * Pure: simplified internal attribute type, which is now always
  3772 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3773 local (Proof.context) attributes have been discontinued, while
  3774 minimizing code duplication. Thm.rule_attribute and
  3775 Thm.declaration_attribute build canonical attributes; see also structure
  3776 Context for further operations on Context.generic, notably
  3777 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3778 declarations and definitions.
  3779 
  3780 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3781 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3782 init only required for impure data. INCOMPATIBILITY: empty really need
  3783 to be empty (no dependencies on theory content!)
  3784 
  3785 * Pure/kernel: consts certification ignores sort constraints given in
  3786 signature declarations. (This information is not relevant to the
  3787 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3788 potential INCOMPATIBILITY.
  3789 
  3790 * Pure: axiomatic type classes are now purely definitional, with
  3791 explicit proofs of class axioms and super class relations performed
  3792 internally. See Pure/axclass.ML for the main internal interfaces --
  3793 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3794 AxClass.axiomatize_class/classrel/arity supersede
  3795 Sign.add_classes/classrel/arities.
  3796 
  3797 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3798 global/local versions on theory vs. Proof.context have been
  3799 discontinued; Attrib.syntax and Method.syntax have been adapted
  3800 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3801 attributes, methods, etc.
  3802 
  3803 * Pure: several functions of signature "... -> theory -> theory * ..."
  3804 have been reoriented to "... -> theory -> ... * theory" in order to
  3805 allow natural usage in combination with the ||>, ||>>, |-> and
  3806 fold_map combinators.
  3807 
  3808 * Pure: official theorem names (closed derivations) and additional
  3809 comments (tags) are now strictly separate.  Name hints -- which are
  3810 maintained as tags -- may be attached any time without affecting the
  3811 derivation.
  3812 
  3813 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3814 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3815 achieve the old behaviour.
  3816 
  3817 * Pure: the "Goal" constant is now called "prop", supporting a
  3818 slightly more general idea of ``protecting'' meta-level rule
  3819 statements.
  3820 
  3821 * Pure: Logic.(un)varify only works in a global context, which is now
  3822 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3823 Logic.legacy_(un)varify as temporary workaround.
  3824 
  3825 * Pure: structure Name provides scalable operations for generating
  3826 internal variable names, notably Name.variants etc.  This replaces
  3827 some popular functions from term.ML:
  3828 
  3829   Term.variant		->  Name.variant
  3830   Term.variantlist	->  Name.variant_list
  3831   Term.invent_names	->  Name.invent_list
  3832 
  3833 Note that low-level renaming rarely occurs in new code -- operations
  3834 from structure Variable are used instead (see below).
  3835 
  3836 * Pure: structure Variable provides fundamental operations for proper
  3837 treatment of fixed/schematic variables in a context.  For example,
  3838 Variable.import introduces fixes for schematics of given facts and
  3839 Variable.export reverses the effect (up to renaming) -- this replaces
  3840 various freeze_thaw operations.
  3841 
  3842 * Pure: structure Goal provides simple interfaces for
  3843 init/conclude/finish and tactical prove operations (replacing former
  3844 Tactic.prove).  Goal.prove is the canonical way to prove results
  3845 within a given context; Goal.prove_global is a degraded version for
  3846 theory level goals, including a global Drule.standard.  Note that
  3847 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3848 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3849 in a locale context).
  3850 
  3851 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3852 and type checking (Syntax.check_term etc.), with common combinations
  3853 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3854 which are considered legacy and await removal.
  3855 
  3856 * Pure/Syntax: generic interfaces for type unchecking
  3857 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3858 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3859 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3860 available for convenience, but refer to the very same operations using
  3861 a mere theory instead of a full context.
  3862 
  3863 * Isar: simplified treatment of user-level errors, using exception
  3864 ERROR of string uniformly.  Function error now merely raises ERROR,
  3865 without any side effect on output channels.  The Isar toplevel takes
  3866 care of proper display of ERROR exceptions.  ML code may use plain
  3867 handle/can/try; cat_error may be used to concatenate errors like this:
  3868 
  3869   ... handle ERROR msg => cat_error msg "..."
  3870 
  3871 Toplevel ML code (run directly or through the Isar toplevel) may be
  3872 embedded into the Isar toplevel with exception display/debug like
  3873 this:
  3874 
  3875   Isar.toplevel (fn () => ...)
  3876 
  3877 INCOMPATIBILITY, removed special transform_error facilities, removed
  3878 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3879 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3880 -- use plain ERROR instead.
  3881 
  3882 * Isar: theory setup now has type (theory -> theory), instead of a
  3883 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3884 
  3885 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3886 ProofContext.debug/verbose flags.
  3887 
  3888 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3889 theory before entering a proof state.  Transactions now always see a
  3890 quasi-functional intermediate checkpoint, both in interactive and
  3891 batch mode.
  3892 
  3893 * Isar: simplified interfaces for outer syntax.  Renamed
  3894 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3895 OuterSyntax.add_parsers -- this functionality is now included in
  3896 OuterSyntax.command etc.  INCOMPATIBILITY.
  3897 
  3898 * Simplifier: the simpset of a running simplification process now
  3899 contains a proof context (cf. Simplifier.the_context), which is the
  3900 very context that the initial simpset has been retrieved from (by
  3901 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3902 (solver, looper etc.) may depend on arbitrary proof data.
  3903 
  3904 * Simplifier.inherit_context inherits the proof context (plus the
  3905 local bounds) of the current simplification process; any simproc
  3906 etc. that calls the Simplifier recursively should do this!  Removed
  3907 former Simplifier.inherit_bounds, which is already included here --
  3908 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3909 specify an explicit context using Simplifier.context/theory_context.
  3910 
  3911 * Simplifier/Classical Reasoner: more abstract interfaces
  3912 change_simpset/claset for modifying the simpset/claset reference of a
  3913 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3914 INCOMPATIBILITY.
  3915 
  3916 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3917 "Trueprop" etc.
  3918 
  3919 
  3920 *** System ***
  3921 
  3922 * settings: the default heap location within ISABELLE_HOME_USER now
  3923 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3924 Isabelle installations.
  3925 
  3926 * isabelle-process: option -S (secure mode) disables some critical
  3927 operations, notably runtime compilation and evaluation of ML source
  3928 code.
  3929 
  3930 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3931 
  3932 * Support for parallel execution, using native multicore support of
  3933 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3934 independent theories, according to the given theory header
  3935 specifications. The maximum number of worker threads is specified via
  3936 usedir option -M or the "max-threads" setting in Proof General. A
  3937 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3938 to 6 on a 8-core machine.  User-code needs to observe certain
  3939 guidelines for thread-safe programming, see appendix A in the Isar
  3940 Implementation manual.
  3941 
  3942 
  3943 
  3944 New in Isabelle2005 (October 2005)
  3945 ----------------------------------
  3946 
  3947 *** General ***
  3948 
  3949 * Theory headers: the new header syntax for Isar theories is
  3950 
  3951   theory <name>
  3952   imports <theory1> ... <theoryN>
  3953   uses <file1> ... <fileM>
  3954   begin
  3955 
  3956 where the 'uses' part is optional.  The previous syntax
  3957 
  3958   theory <name> = <theory1> + ... + <theoryN>:
  3959 
  3960 will disappear in the next release.  Use isatool fixheaders to convert
  3961 existing theory files.  Note that there is no change in ancient
  3962 non-Isar theories now, but these will disappear soon.
  3963 
  3964 * Theory loader: parent theories can now also be referred to via
  3965 relative and absolute paths.
  3966 
  3967 * Command 'find_theorems' searches for a list of criteria instead of a
  3968 list of constants. Known criteria are: intro, elim, dest, name:string,
  3969 simp:term, and any term. Criteria can be preceded by '-' to select
  3970 theorems that do not match. Intro, elim, dest select theorems that
  3971 match the current goal, name:s selects theorems whose fully qualified
  3972 name contain s, and simp:term selects all simplification rules whose
  3973 lhs match term.  Any other term is interpreted as pattern and selects
  3974 all theorems matching the pattern. Available in ProofGeneral under
  3975 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3976 
  3977   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3978 
  3979 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3980 matching the current goal as introduction rule and not having "HOL."
  3981 in their name (i.e. not being defined in theory HOL).
  3982 
  3983 * Command 'thms_containing' has been discontinued in favour of
  3984 'find_theorems'; INCOMPATIBILITY.
  3985 
  3986 * Communication with Proof General is now 8bit clean, which means that
  3987 Unicode text in UTF-8 encoding may be used within theory texts (both
  3988 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3989 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3990 
  3991   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3992   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3993 
  3994 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3995 Classical Reasoner.  Typical big applications run around 2 times
  3996 faster.
  3997 
  3998 
  3999 *** Document preparation ***
  4000 
  4001 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4002 of raw sources.  Only those symbols that do not require additional
  4003 LaTeX packages (depending on comments in isabellesym.sty) are
  4004 displayed properly, everything else is left verbatim.  isatool display
  4005 and isatool print are used as front ends (these are subject to the
  4006 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4007 
  4008 * Command tags control specific markup of certain regions of text,
  4009 notably folding and hiding.  Predefined tags include "theory" (for
  4010 theory begin and end), "proof" for proof commands, and "ML" for
  4011 commands involving ML code; the additional tags "visible" and
  4012 "invisible" are unused by default.  Users may give explicit tag
  4013 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4014 interpretation of tags is determined by the LaTeX job during document
  4015 preparation: see option -V of isatool usedir, or options -n and -t of
  4016 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4017 \isadroptag.
  4018 
  4019 Several document versions may be produced at the same time via isatool
  4020 usedir (the generated index.html will link all of them).  Typical
  4021 specifications include ''-V document=theory,proof,ML'' to present
  4022 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4023 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4024 these parts without any formal replacement text.  The Isabelle site
  4025 default settings produce ''document'' and ''outline'' versions as
  4026 specified above.
  4027 
  4028 * Several new antiquotations:
  4029 
  4030   @{term_type term} prints a term with its type annotated;
  4031 
  4032   @{typeof term} prints the type of a term;
  4033 
  4034   @{const const} is the same as @{term const}, but checks that the
  4035   argument is a known logical constant;
  4036 
  4037   @{term_style style term} and @{thm_style style thm} print a term or
  4038   theorem applying a "style" to it
  4039 
  4040   @{ML text}
  4041 
  4042 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4043 definitions, equations, inequations etc., 'concl' printing only the
  4044 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4045 to print the specified premise.  TermStyle.add_style provides an ML
  4046 interface for introducing further styles.  See also the "LaTeX Sugar"
  4047 document practical applications.  The ML antiquotation prints
  4048 type-checked ML expressions verbatim.
  4049 
  4050 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4051 and 'text' support optional locale specification '(in loc)', which
  4052 specifies the default context for interpreting antiquotations.  For
  4053 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4054 
  4055 * Option 'locale=NAME' of antiquotations specifies an alternative
  4056 context interpreting the subsequent argument.  For example: @{thm
  4057 [locale=lattice] inf_assoc}.
  4058 
  4059 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4060 a proof context.
  4061 
  4062 * Proper output of antiquotations for theory commands involving a
  4063 proof context (such as 'locale' or 'theorem (in loc) ...').
  4064 
  4065 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4066 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4067 
  4068 * isatool usedir: new option -C (default true) controls whether option
  4069 -D should include a copy of the original document directory; -C false
  4070 prevents unwanted effects such as copying of administrative CVS data.
  4071 
  4072 
  4073 *** Pure ***
  4074 
  4075 * Considerably improved version of 'constdefs' command.  Now performs
  4076 automatic type-inference of declared constants; additional support for
  4077 local structure declarations (cf. locales and HOL records), see also
  4078 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4079 sequential dependencies of definitions within a single 'constdefs'
  4080 section; moreover, the declared name needs to be an identifier.  If
  4081 all fails, consider to fall back on 'consts' and 'defs' separately.
  4082 
  4083 * Improved indexed syntax and implicit structures.  First of all,
  4084 indexed syntax provides a notational device for subscripted
  4085 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4086 expressions.  Secondly, in a local context with structure
  4087 declarations, number indexes \<^sub>n or the empty index (default
  4088 number 1) refer to a certain fixed variable implicitly; option
  4089 show_structs controls printing of implicit structures.  Typical
  4090 applications of these concepts involve record types and locales.
  4091 
  4092 * New command 'no_syntax' removes grammar declarations (and
  4093 translations) resulting from the given syntax specification, which is
  4094 interpreted in the same manner as for the 'syntax' command.
  4095 
  4096 * 'Advanced' translation functions (parse_translation etc.) may depend
  4097 on the signature of the theory context being presently used for
  4098 parsing/printing, see also isar-ref manual.
  4099 
  4100 * Improved 'oracle' command provides a type-safe interface to turn an
  4101 ML expression of type theory -> T -> term into a primitive rule of
  4102 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4103 is already included here); see also FOL/ex/IffExample.thy;
  4104 INCOMPATIBILITY.
  4105 
  4106 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4107 before); "cI" is no longer bound, use "c.intro" instead.
  4108 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4109 axclasses vs. locales.
  4110 
  4111 * Improved internal renaming of symbolic identifiers -- attach primes
  4112 instead of base 26 numbers.
  4113 
  4114 * New flag show_question_marks controls printing of leading question
  4115 marks in schematic variable names.
  4116 
  4117 * In schematic variable names, *any* symbol following \<^isub> or
  4118 \<^isup> is now treated as part of the base name.  For example, the
  4119 following works without printing of awkward ".0" indexes:
  4120 
  4121   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4122     by simp
  4123 
  4124 * Inner syntax includes (*(*nested*) comments*).
  4125 
  4126 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4127 annotations as "(00...)".
  4128 
  4129 * Clear separation of logical types and nonterminals, where the latter
  4130 may only occur in 'syntax' specifications or type abbreviations.
  4131 Before that distinction was only partially implemented via type class
  4132 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4133 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4134 exotic syntax specifications may require further adaption
  4135 (e.g. Cube/Cube.thy).
  4136 
  4137 * Removed obsolete type class "logic", use the top sort {} instead.
  4138 Note that non-logical types should be declared as 'nonterminals'
  4139 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4140 specifications.
  4141 
  4142 * Attributes 'induct' and 'cases': type or set names may now be
  4143 locally fixed variables as well.
  4144 
  4145 * Simplifier: can now control the depth to which conditional rewriting
  4146 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4147 Limit.
  4148 
  4149 * Simplifier: simplification procedures may now take the current
  4150 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4151 interface), which is very useful for calling the Simplifier
  4152 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4153 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4154 low-level mk_simproc no longer applies Logic.varify internally, to
  4155 allow for use in a context of fixed variables.
  4156 
  4157 * thin_tac now works even if the assumption being deleted contains !!
  4158 or ==>.  More generally, erule now works even if the major premise of
  4159 the elimination rule contains !! or ==>.
  4160 
  4161 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4162 
  4163 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4164 from Pure, which contains all common declarations already.  Both
  4165 theories are defined via plain Isabelle/Isar .thy files.
  4166 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4167 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4168 use isatool fixcpure to adapt your theory and ML sources.
  4169 
  4170 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4171 selections of theorems in named facts via index ranges.
  4172 
  4173 * 'print_theorems': in theory mode, really print the difference
  4174 wrt. the last state (works for interactive theory development only),
  4175 in proof mode print all local facts (cf. 'print_facts');
  4176 
  4177 * 'hide': option '(open)' hides only base names.
  4178 
  4179 * More efficient treatment of intermediate checkpoints in interactive
  4180 theory development.
  4181 
  4182 * Code generator is now invoked via code_module (incremental code
  4183 generation) and code_library (modular code generation, ML structures
  4184 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4185 must be quoted when used as identifiers.
  4186 
  4187 * New 'value' command for reading, evaluating and printing terms using
  4188 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4189 quoted when used as identifier.
  4190 
  4191 
  4192 *** Locales ***
  4193 
  4194 * New commands for the interpretation of locale expressions in
  4195 theories (1), locales (2) and proof contexts (3).  These generate
  4196 proof obligations from the expression specification.  After the
  4197 obligations have been discharged, theorems of the expression are added
  4198 to the theory, target locale or proof context.  The synopsis of the
  4199 commands is a follows:
  4200 
  4201   (1) interpretation expr inst
  4202   (2) interpretation target < expr
  4203   (3) interpret expr inst
  4204 
  4205 Interpretation in theories and proof contexts require a parameter
  4206 instantiation of terms from the current context.  This is applied to
  4207 specifications and theorems of the interpreted expression.
  4208 Interpretation in locales only permits parameter renaming through the
  4209 locale expression.  Interpretation is smart in that interpretations
  4210 that are active already do not occur in proof obligations, neither are
  4211 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4212 inspect active interpretations of a particular locale.  For details,
  4213 see the Isar Reference manual.  Examples can be found in
  4214 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4215 
  4216 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4217 'interpret' instead.
  4218 
  4219 * New context element 'constrains' for adding type constraints to
  4220 parameters.
  4221 
  4222 * Context expressions: renaming of parameters with syntax
  4223 redeclaration.
  4224 
  4225 * Locale declaration: 'includes' disallowed.
  4226 
  4227 * Proper static binding of attribute syntax -- i.e. types / terms /
  4228 facts mentioned as arguments are always those of the locale definition
  4229 context, independently of the context of later invocations.  Moreover,
  4230 locale operations (renaming and type / term instantiation) are applied
  4231 to attribute arguments as expected.
  4232 
  4233 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4234 actual attributes; rare situations may require Attrib.attribute to
  4235 embed those attributes into Attrib.src that lack concrete syntax.
  4236 Attribute implementations need to cooperate properly with the static
  4237 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4238 Attrib.XXX_thm etc. already do the right thing without further
  4239 intervention.  Only unusual applications -- such as "where" or "of"
  4240 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4241 on the context and the facts involved -- may have to assign parsed
  4242 values to argument tokens explicitly.
  4243 
  4244 * Changed parameter management in theorem generation for long goal
  4245 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4246 theorem statement in rare situations.
  4247 
  4248 * Locale inspection command 'print_locale' omits notes elements.  Use
  4249 'print_locale!' to have them included in the output.
  4250 
  4251 
  4252 *** Provers ***
  4253 
  4254 * Provers/hypsubst.ML: improved version of the subst method, for
  4255 single-step rewriting: it now works in bound variable contexts. New is
  4256 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4257 rewrite a different subterm than the original subst method, which is
  4258 still available as 'simplesubst'.
  4259 
  4260 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4261 and quasi orders.
  4262 
  4263 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4264 reflexive-transitive closure of relations.
  4265 
  4266 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4267 limit (previously hard-coded with a value of 20) user-definable.
  4268 
  4269 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4270 is peformed already.  Object-logics merely need to finish their
  4271 initial simpset configuration as before.  INCOMPATIBILITY.
  4272 
  4273 
  4274 *** HOL ***
  4275 
  4276 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4277 
  4278   syntax (epsilon)
  4279     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4280 
  4281 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4282 and x-symbol; use option '-m epsilon' to get it actually printed.
  4283 Moreover, the mathematically important symbolic identifier \<epsilon>
  4284 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4285 
  4286 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4287 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4288 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4289 support corresponding Isar calculations.
  4290 
  4291 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4292 instead of ":".
  4293 
  4294 * theory SetInterval: changed the syntax for open intervals:
  4295 
  4296   Old       New
  4297   {..n(}    {..<n}
  4298   {)n..}    {n<..}
  4299   {m..n(}   {m..<n}
  4300   {)m..n}   {m<..n}
  4301   {)m..n(}  {m<..<n}
  4302 
  4303 The old syntax is still supported but will disappear in the next
  4304 release.  For conversion use the following Emacs search and replace
  4305 patterns (these are not perfect but work quite well):
  4306 
  4307   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4308   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4309 
  4310 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4311 equalities in commutative rings; method 'algebra' provides a generic
  4312 interface.
  4313 
  4314 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4315 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4316 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4317 be a tuple pattern.
  4318 
  4319 Some new syntax forms are available:
  4320 
  4321   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4322   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4323   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4324   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4325 
  4326 The latter form "\<Sum>x < k. e" used to be based on a separate
  4327 function "Summation", which has been discontinued.
  4328 
  4329 * theory Finite_Set: in structured induction proofs, the insert case
  4330 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4331 (insert F x)'.
  4332 
  4333 * The 'refute' command has been extended to support a much larger
  4334 fragment of HOL, including axiomatic type classes, constdefs and
  4335 typedefs, inductive datatypes and recursion.
  4336 
  4337 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4338 Requires zChaff with proof generation to be installed.  See
  4339 HOL/ex/SAT_Examples.thy for examples.
  4340 
  4341 * Datatype induction via method 'induct' now preserves the name of the
  4342 induction variable. For example, when proving P(xs::'a list) by
  4343 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4344 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4345 in unstructured proof scripts.
  4346 
  4347 * Reworked implementation of records.  Improved scalability for
  4348 records with many fields, avoiding performance problems for type
  4349 inference. Records are no longer composed of nested field types, but
  4350 of nested extension types. Therefore the record type only grows linear
  4351 in the number of extensions and not in the number of fields.  The
  4352 top-level (users) view on records is preserved.  Potential
  4353 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4354 old record representation. The type generated for a record is called
  4355 <record_name>_ext_type.
  4356 
  4357 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4358 proofs triggered by a record definition or a simproc (if
  4359 quick_and_dirty is enabled).  Definitions of large records can take
  4360 quite long.
  4361 
  4362 New simproc record_upd_simproc for simplification of multiple record
  4363 updates enabled by default.  Moreover, trivial updates are also
  4364 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4365 occasionally, since simplification is more powerful by default.
  4366 
  4367 * typedef: proper support for polymorphic sets, which contain extra
  4368 type-variables in the term.
  4369 
  4370 * Simplifier: automatically reasons about transitivity chains
  4371 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4372 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4373 old proofs break occasionally as simplification may now solve more
  4374 goals than previously.
  4375 
  4376 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4377 present.  Works for all partial orders (class "order"), in particular
  4378 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4379 just like y <= x.
  4380 
  4381 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4382 bound variable or a constant then the let is unfolded.  Otherwise
  4383 first a is simplified to b, and then f b is simplified to g. If
  4384 possible we abstract b from g arriving at "let x = b in h x",
  4385 otherwise we unfold the let and arrive at g.  The simproc can be
  4386 enabled/disabled by the reference use_let_simproc.  Potential
  4387 INCOMPATIBILITY since simplification is more powerful by default.
  4388 
  4389 * Classical reasoning: the meson method now accepts theorems as arguments.
  4390 
  4391 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4392 jobs to provide advice on the provability of subgoals.
  4393 
  4394 * Theory OrderedGroup and Ring_and_Field: various additions and
  4395 improvements to faciliate calculations involving equalities and
  4396 inequalities.
  4397 
  4398 The following theorems have been eliminated or modified
  4399 (INCOMPATIBILITY):
  4400 
  4401   abs_eq             now named abs_of_nonneg
  4402   abs_of_ge_0        now named abs_of_nonneg
  4403   abs_minus_eq       now named abs_of_nonpos
  4404   imp_abs_id         now named abs_of_nonneg
  4405   imp_abs_neg_id     now named abs_of_nonpos
  4406   mult_pos           now named mult_pos_pos
  4407   mult_pos_le        now named mult_nonneg_nonneg
  4408   mult_pos_neg_le    now named mult_nonneg_nonpos
  4409   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4410   mult_neg           now named mult_neg_neg
  4411   mult_neg_le        now named mult_nonpos_nonpos
  4412 
  4413 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4414      
  4415      zero_le_square
  4416      not_square_less_zero 
  4417 
  4418   The following lemmas have been deleted from Real/RealPow:
  4419   
  4420      realpow_zero_zero
  4421      realpow_two
  4422      realpow_less
  4423      zero_le_power
  4424      realpow_two_le
  4425      abs_realpow_two
  4426      realpow_two_abs     
  4427 
  4428 * Theory Parity: added rules for simplifying exponents.
  4429 
  4430 * Theory List:
  4431 
  4432 The following theorems have been eliminated or modified
  4433 (INCOMPATIBILITY):
  4434 
  4435   list_all_Nil       now named list_all.simps(1)
  4436   list_all_Cons      now named list_all.simps(2)
  4437   list_all_conv      now named list_all_iff
  4438   set_mem_eq         now named mem_iff
  4439 
  4440 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4441 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4442 
  4443 
  4444 *** HOL-Complex ***
  4445 
  4446 * Theory RealDef: better support for embedding natural numbers and
  4447 integers in the reals.
  4448 
  4449 The following theorems have been eliminated or modified
  4450 (INCOMPATIBILITY):
  4451 
  4452   exp_ge_add_one_self  now requires no hypotheses
  4453   real_of_int_add      reversed direction of equality (use [symmetric])
  4454   real_of_int_minus    reversed direction of equality (use [symmetric])
  4455   real_of_int_diff     reversed direction of equality (use [symmetric])
  4456   real_of_int_mult     reversed direction of equality (use [symmetric])
  4457 
  4458 * Theory RComplete: expanded support for floor and ceiling functions.
  4459 
  4460 * Theory Ln is new, with properties of the natural logarithm
  4461 
  4462 * Hyperreal: There is a new type constructor "star" for making
  4463 nonstandard types.  The old type names are now type synonyms:
  4464 
  4465   hypreal = real star
  4466   hypnat = nat star
  4467   hcomplex = complex star
  4468 
  4469 * Hyperreal: Many groups of similarly-defined constants have been
  4470 replaced by polymorphic versions (INCOMPATIBILITY):
  4471 
  4472   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4473 
  4474   starset      <-- starsetNat, starsetC
  4475   *s*          <-- *sNat*, *sc*
  4476   starset_n    <-- starsetNat_n, starsetC_n
  4477   *sn*         <-- *sNatn*, *scn*
  4478   InternalSets <-- InternalNatSets, InternalCSets
  4479 
  4480   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4481   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4482   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4483   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4484   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4485 
  4486 * Hyperreal: Many type-specific theorems have been removed in favor of
  4487 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4488 
  4489   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4490   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4491   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4492   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4493   right_minus <-- hypreal_add_minus
  4494   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4495   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4496   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4497   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4498   mult_1_right <-- hcomplex_mult_one_right
  4499   mult_zero_left <-- hcomplex_mult_zero_left
  4500   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4501   right_distrib <-- hypnat_add_mult_distrib2
  4502   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4503   right_inverse <-- hypreal_mult_inverse
  4504   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4505   order_refl <-- {hypreal,hypnat}_le_refl
  4506   order_trans <-- {hypreal,hypnat}_le_trans
  4507   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4508   order_less_le <-- {hypreal,hypnat}_less_le
  4509   linorder_linear <-- {hypreal,hypnat}_le_linear
  4510   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4511   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4512   add_nonneg_nonneg <-- hypreal_le_add_order
  4513 
  4514 * Hyperreal: Separate theorems having to do with type-specific
  4515 versions of constants have been merged into theorems that apply to the
  4516 new polymorphic constants (INCOMPATIBILITY):
  4517 
  4518   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4519   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4520   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4521   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4522   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4523   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4524   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4525   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4526   STAR_diff <-- {STAR,STARC}_diff
  4527   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4528     STARC_hcomplex_of_complex}_image_subset
  4529   starset_n_Un <-- starset{Nat,C}_n_Un
  4530   starset_n_Int <-- starset{Nat,C}_n_Int
  4531   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4532   starset_n_diff <-- starset{Nat,C}_n_diff
  4533   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4534   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4535   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4536   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4537   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4538   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4539   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4540   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4541   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4542   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4543   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4544   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4545   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4546   starfun_diff <-- starfun{C,RC,CR}_diff
  4547   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4548   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4549   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4550   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4551   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4552   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4553   starfun_Id <-- starfunC_Id
  4554   starfun_approx <-- starfun{Nat,CR}_approx
  4555   starfun_capprox <-- starfun{C,RC}_capprox
  4556   starfun_abs <-- starfunNat_rabs
  4557   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4558   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4559   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4560   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4561   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4562   starfun_add_approx <-- starfunCR_add_approx
  4563   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4564   starfun_divide <-- starfun{C,CR,RC}_divide
  4565   starfun_n <-- starfun{Nat,C}_n
  4566   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4567   starfun_n_add <-- starfun{Nat,C}_n_add
  4568   starfun_n_add_minus <-- starfunNat_n_add_minus
  4569   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4570   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4571   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4572 
  4573   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4574   star_n_minus <-- {hypreal,hcomplex}_minus
  4575   star_n_diff <-- {hypreal,hcomplex}_diff
  4576   star_n_mult <-- {hypreal,hcomplex}_mult
  4577   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4578   star_n_le <-- {hypreal,hypnat}_le
  4579   star_n_less <-- {hypreal,hypnat}_less
  4580   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4581   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4582   star_n_abs <-- hypreal_hrabs
  4583   star_n_divide <-- hcomplex_divide
  4584 
  4585   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4586   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4587   star_of_diff <-- hypreal_of_real_diff
  4588   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4589   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4590   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4591   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4592   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4593   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4594   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4595   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4596   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4597   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4598   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4599   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4600   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4601   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4602   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4603   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4604   star_of_power <-- hypreal_of_real_power
  4605   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4606 
  4607 * Hyperreal: new method "transfer" that implements the transfer
  4608 principle of nonstandard analysis. With a subgoal that mentions
  4609 nonstandard types like "'a star", the command "apply transfer"
  4610 replaces it with an equivalent one that mentions only standard types.
  4611 To be successful, all free variables must have standard types; non-
  4612 standard variables must have explicit universal quantifiers.
  4613 
  4614 * Hyperreal: A theory of Taylor series.
  4615 
  4616 
  4617 *** HOLCF ***
  4618 
  4619 * Discontinued special version of 'constdefs' (which used to support
  4620 continuous functions) in favor of the general Pure one with full
  4621 type-inference.
  4622 
  4623 * New simplification procedure for solving continuity conditions; it
  4624 is much faster on terms with many nested lambda abstractions (cubic
  4625 instead of exponential time).
  4626 
  4627 * New syntax for domain package: selector names are now optional.
  4628 Parentheses should be omitted unless argument is lazy, for example:
  4629 
  4630   domain 'a stream = cons "'a" (lazy "'a stream")
  4631 
  4632 * New command 'fixrec' for defining recursive functions with pattern
  4633 matching; defining multiple functions with mutual recursion is also
  4634 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4635 sinr, or any data constructor defined by the domain package. The given
  4636 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4637 syntax and examples.
  4638 
  4639 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4640 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4641 but the proof obligation additionally includes an admissibility
  4642 requirement. The packages generate instances of class cpo or pcpo,
  4643 with continuity and strictness theorems for Rep and Abs.
  4644 
  4645 * HOLCF: Many theorems have been renamed according to a more standard naming
  4646 scheme (INCOMPATIBILITY):
  4647 
  4648   foo_inject:  "foo$x = foo$y ==> x = y"
  4649   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4650   foo_less:    "(foo$x << foo$y) = (x << y)"
  4651   foo_strict:  "foo$UU = UU"
  4652   foo_defined: "... ==> foo$x ~= UU"
  4653   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4654 
  4655 
  4656 *** ZF ***
  4657 
  4658 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4659 including the First Isomorphism Theorem (on quotienting by the kernel
  4660 of a homomorphism).
  4661 
  4662 * ZF/Simplifier: install second copy of type solver that actually
  4663 makes use of TC rules declared to Isar proof contexts (or locales);
  4664 the old version is still required for ML proof scripts.
  4665 
  4666 
  4667 *** Cube ***
  4668 
  4669 * Converted to Isar theory format; use locales instead of axiomatic
  4670 theories.
  4671 
  4672 
  4673 *** ML ***
  4674 
  4675 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4676 for ||>, ||>>, |>>,
  4677 
  4678 * Pure/library.ML no longer defines its own option datatype, but uses
  4679 that of the SML basis, which has constructors NONE and SOME instead of
  4680 None and Some, as well as exception Option.Option instead of OPTION.
  4681 The functions the, if_none, is_some, is_none have been adapted
  4682 accordingly, while Option.map replaces apsome.
  4683 
  4684 * Pure/library.ML: the exception LIST has been given up in favour of
  4685 the standard exceptions Empty and Subscript, as well as
  4686 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4687 superceded by the standard hd and tl functions etc.
  4688 
  4689 A number of basic list functions are no longer exported to the ML
  4690 toplevel, as they are variants of predefined functions.  The following
  4691 suggests how one can translate existing code:
  4692 
  4693     rev_append xs ys = List.revAppend (xs, ys)
  4694     nth_elem (i, xs) = List.nth (xs, i)
  4695     last_elem xs = List.last xs
  4696     flat xss = List.concat xss
  4697     seq fs = List.app fs
  4698     partition P xs = List.partition P xs
  4699     mapfilter f xs = List.mapPartial f xs
  4700 
  4701 * Pure/library.ML: several combinators for linear functional
  4702 transformations, notably reverse application and composition:
  4703 
  4704   x |> f                f #> g
  4705   (x, y) |-> f          f #-> g
  4706 
  4707 * Pure/library.ML: introduced/changed precedence of infix operators:
  4708 
  4709   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4710   infix 2 ?;
  4711   infix 3 o oo ooo oooo;
  4712   infix 4 ~~ upto downto;
  4713 
  4714 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4715 infix operators.
  4716 
  4717 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4718 fold_map support linear functional transformations and nesting.  For
  4719 example:
  4720 
  4721   fold f [x1, ..., xN] y =
  4722     y |> f x1 |> ... |> f xN
  4723 
  4724   (fold o fold) f [xs1, ..., xsN] y =
  4725     y |> fold f xs1 |> ... |> fold f xsN
  4726 
  4727   fold f [x1, ..., xN] =
  4728     f x1 #> ... #> f xN
  4729 
  4730   (fold o fold) f [xs1, ..., xsN] =
  4731     fold f xs1 #> ... #> fold f xsN
  4732 
  4733 * Pure/library.ML: the following selectors on type 'a option are
  4734 available:
  4735 
  4736   the:               'a option -> 'a  (*partial*)
  4737   these:             'a option -> 'a  where 'a = 'b list
  4738   the_default: 'a -> 'a option -> 'a
  4739   the_list:          'a option -> 'a list
  4740 
  4741 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4742 basic operations for association lists, following natural argument
  4743 order; moreover the explicit equality predicate passed here avoids
  4744 potentially expensive polymorphic runtime equality checks.
  4745 The old functions may be expressed as follows:
  4746 
  4747   assoc = uncurry (AList.lookup (op =))
  4748   assocs = these oo AList.lookup (op =)
  4749   overwrite = uncurry (AList.update (op =)) o swap
  4750 
  4751 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4752 
  4753   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4754   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4755 
  4756 replacing make_keylist and keyfilter (occassionally used)
  4757 Naive rewrites:
  4758 
  4759   make_keylist = AList.make
  4760   keyfilter = AList.find (op =)
  4761 
  4762 * eq_fst and eq_snd now take explicit equality parameter, thus
  4763   avoiding eqtypes. Naive rewrites:
  4764 
  4765     eq_fst = eq_fst (op =)
  4766     eq_snd = eq_snd (op =)
  4767 
  4768 * Removed deprecated apl and apr (rarely used).
  4769   Naive rewrites:
  4770 
  4771     apl (n, op) =>>= curry op n
  4772     apr (op, m) =>>= fn n => op (n, m)
  4773 
  4774 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4775 provides a reasonably efficient light-weight implementation of sets as
  4776 lists.
  4777 
  4778 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4779 few new operations; existing lookup and update are now curried to
  4780 follow natural argument order (for use with fold etc.);
  4781 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4782 
  4783 * Pure/General: output via the Isabelle channels of
  4784 writeln/warning/error etc. is now passed through Output.output, with a
  4785 hook for arbitrary transformations depending on the print_mode
  4786 (cf. Output.add_mode -- the first active mode that provides a output
  4787 function wins).  Already formatted output may be embedded into further
  4788 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4789 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4790 accommodate easy composition of diagnostic messages etc.  Programmers
  4791 rarely need to care about Output.output or Output.raw at all, with
  4792 some notable exceptions: Output.output is required when bypassing the
  4793 standard channels (writeln etc.), or in token translations to produce
  4794 properly formatted results; Output.raw is required when capturing
  4795 already output material that will eventually be presented to the user
  4796 a second time.  For the default print mode, both Output.output and
  4797 Output.raw have no effect.
  4798 
  4799 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4800 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4801 cumulative results are displayed at the end of a batch session.
  4802 
  4803 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4804 replaced by File.platform_path and File.shell_path (with appropriate
  4805 hooks).  This provides a clean interface for unusual systems where the
  4806 internal and external process view of file names are different.
  4807 
  4808 * Pure: more efficient orders for basic syntactic entities: added
  4809 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4810 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4811 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4812 orders now -- potential INCOMPATIBILITY for code that depends on a
  4813 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4814 Library.sort_strings on result).
  4815 
  4816 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4817 fold_types traverse types/terms from left to right, observing natural
  4818 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4819 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4820 
  4821 * Pure: name spaces have been refined, with significant changes of the
  4822 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4823 to extern(_table).  The plain name entry path is superceded by a
  4824 general 'naming' context, which also includes the 'policy' to produce
  4825 a fully qualified name and external accesses of a fully qualified
  4826 name; NameSpace.extend is superceded by context dependent
  4827 Sign.declare_name.  Several theory and proof context operations modify
  4828 the naming context.  Especially note Theory.restore_naming and
  4829 ProofContext.restore_naming to get back to a sane state; note that
  4830 Theory.add_path is no longer sufficient to recover from
  4831 Theory.absolute_path in particular.
  4832 
  4833 * Pure: new flags short_names (default false) and unique_names
  4834 (default true) for controlling output of qualified names.  If
  4835 short_names is set, names are printed unqualified.  If unique_names is
  4836 reset, the name prefix is reduced to the minimum required to achieve
  4837 the original result when interning again, even if there is an overlap
  4838 with earlier declarations.
  4839 
  4840 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4841 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4842 (useful for printing error messages).  INCOMPATIBILITY.
  4843 
  4844 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4845 Theory.theory are now identified, referring to the universal
  4846 Context.theory (see Pure/context.ML).  Actual signature and theory
  4847 content is managed as theory data.  The old code and interfaces were
  4848 spread over many files and structures; the new arrangement introduces
  4849 considerable INCOMPATIBILITY to gain more clarity:
  4850 
  4851   Context -- theory management operations (name, identity, inclusion,
  4852     parents, ancestors, merge, etc.), plus generic theory data;
  4853 
  4854   Sign -- logical signature and syntax operations (declaring consts,
  4855     types, etc.), plus certify/read for common entities;
  4856 
  4857   Theory -- logical theory operations (stating axioms, definitions,
  4858     oracles), plus a copy of logical signature operations (consts,
  4859     types, etc.); also a few basic management operations (Theory.copy,
  4860     Theory.merge, etc.)
  4861 
  4862 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4863 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4864 for convenience -- they merely return the theory.
  4865 
  4866 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4867 
  4868 * Pure: the Isar proof context type is already defined early in Pure
  4869 as Context.proof (note that ProofContext.context and Proof.context are
  4870 aliases, where the latter is the preferred name).  This enables other
  4871 Isabelle components to refer to that type even before Isar is present.
  4872 
  4873 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4874 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4875 any of these kinds.  For example, Sign.intern typeK is now
  4876 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4877 Theory.hide_types.  Also note that former
  4878 Theory.hide_classes/types/consts are now
  4879 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4880 internalize their arguments!  INCOMPATIBILITY.
  4881 
  4882 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4883 datatype thmref (with constructors Name and NameSelection) instead of
  4884 plain string -- INCOMPATIBILITY;
  4885 
  4886 * Pure: cases produced by proof methods specify options, where NONE
  4887 means to remove case bindings -- INCOMPATIBILITY in
  4888 (RAW_)METHOD_CASES.
  4889 
  4890 * Pure: the following operations retrieve axioms or theorems from a
  4891 theory node or theory hierarchy, respectively:
  4892 
  4893   Theory.axioms_of: theory -> (string * term) list
  4894   Theory.all_axioms_of: theory -> (string * term) list
  4895   PureThy.thms_of: theory -> (string * thm) list
  4896   PureThy.all_thms_of: theory -> (string * thm) list
  4897 
  4898 * Pure: print_tac now outputs the goal through the trace channel.
  4899 
  4900 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4901 Reference Toplevel.debug (default false) controls detailed printing
  4902 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4903 controls execution profiling -- set to 1 for time and 2 for space
  4904 (both increase the runtime).
  4905 
  4906 * Isar session: The initial use of ROOT.ML is now always timed,
  4907 i.e. the log will show the actual process times, in contrast to the
  4908 elapsed wall-clock time that the outer shell wrapper produces.
  4909 
  4910 * Simplifier: improved handling of bound variables (nameless
  4911 representation, avoid allocating new strings).  Simprocs that invoke
  4912 the Simplifier recursively should use Simplifier.inherit_bounds to
  4913 avoid local name clashes.  Failure to do so produces warnings
  4914 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4915 for further details.
  4916 
  4917 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4918 bindings for all theorems stored within a given theory; this may help
  4919 in porting non-Isar theories to Isar ones, while keeping ML proof
  4920 scripts for the time being.
  4921 
  4922 * ML operator HTML.with_charset specifies the charset begin used for
  4923 generated HTML files.  For example:
  4924 
  4925   HTML.with_charset "utf-8" use_thy "Hebrew";
  4926   HTML.with_charset "utf-8" use_thy "Chinese";
  4927 
  4928 
  4929 *** System ***
  4930 
  4931 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4932 isabelle, isatool etc.).
  4933 
  4934 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4935 isatool doc, isatool mkdir, display_drafts etc.).
  4936 
  4937 * isatool usedir: option -f allows specification of the ML file to be
  4938 used by Isabelle; default is ROOT.ML.
  4939 
  4940 * New isatool version outputs the version identifier of the Isabelle
  4941 distribution being used.
  4942 
  4943 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4944 (containing Boolean satisfiability problems) into Isabelle/HOL
  4945 theories.
  4946 
  4947 
  4948 
  4949 New in Isabelle2004 (April 2004)
  4950 --------------------------------
  4951 
  4952 *** General ***
  4953 
  4954 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4955   Replaces linorder.ML.
  4956 
  4957 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4958   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4959   (\<a>...\<z>), are now considered normal letters, and can therefore
  4960   be used anywhere where an ASCII letter (a...zA...Z) has until
  4961   now. COMPATIBILITY: This obviously changes the parsing of some
  4962   terms, especially where a symbol has been used as a binder, say
  4963   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4964   as an identifier.  Fix it by inserting a space around former
  4965   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4966   existing theory and ML files.
  4967 
  4968 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4969 
  4970 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4971   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4972   a normal (but invisible) letter. For multiple letter subscripts repeat
  4973   \<^isub> like this: x\<^isub>1\<^isub>2.
  4974 
  4975 * Pure: There are now sub-/superscripts that can span more than one
  4976   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4977   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4978   superscript. The new control characters are not identifier parts.
  4979 
  4980 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4981   content of "..." to the latex file instead of \isacntrl... . The "..."
  4982   may consist of any printable characters excluding the end bracket >.
  4983 
  4984 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4985   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4986   declare constants "final", which prevents their being given a definition
  4987   later.  It is useful for constants whose behaviour is fixed axiomatically
  4988   rather than definitionally, such as the meta-logic connectives.
  4989 
  4990 * Pure: 'instance' now handles general arities with general sorts
  4991   (i.e. intersections of classes),
  4992 
  4993 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4994   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4995   It can be changed to alter the colors/layout of generated pages.
  4996 
  4997 
  4998 *** Isar ***
  4999 
  5000 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5001   cut_tac, subgoal_tac and thin_tac:
  5002   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5003     locales are no longer forced to write Isar proof scripts.
  5004     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5005     emulations.
  5006   - INCOMPATIBILITY: names of variables to be instantiated may no
  5007     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5008     This is consistent with the instantiation attribute "where".
  5009 
  5010 * Attributes "where" and "of":
  5011   - Now take type variables of instantiated theorem into account when reading
  5012     the instantiation string.  This fixes a bug that caused instantiated
  5013     theorems to have too special types in some circumstances.
  5014   - "where" permits explicit instantiations of type variables.
  5015 
  5016 * Calculation commands "moreover" and "also" no longer interfere with
  5017   current facts ("this"), admitting arbitrary combinations with "then"
  5018   and derived forms.
  5019 
  5020 * Locales:
  5021   - Goal statements involving the context element "includes" no longer
  5022     generate theorems with internal delta predicates (those ending on
  5023     "_axioms") in the premise.
  5024     Resolve particular premise with <locale>.intro to obtain old form.
  5025   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5026     specification and "includes" elements in goal statement.
  5027   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5028     [intro?] and [elim?] (respectively) by default.
  5029   - Experimental command for instantiation of locales in proof contexts:
  5030         instantiate <label>[<attrs>]: <loc>
  5031     Instantiates locale <loc> and adds all its theorems to the current context
  5032     taking into account their attributes.  Label and attrs are optional
  5033     modifiers, like in theorem declarations.  If present, names of
  5034     instantiated theorems are qualified with <label>, and the attributes
  5035     <attrs> are applied after any attributes these theorems might have already.
  5036       If the locale has assumptions, a chained fact of the form
  5037     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5038     are derived.  The command does not support old-style locales declared
  5039     with "locale (open)".
  5040       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5041 
  5042 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5043   (Isar) contexts.
  5044 
  5045 
  5046 *** HOL ***
  5047 
  5048 * Proof import: new image HOL4 contains the imported library from
  5049   the HOL4 system with about 2500 theorems. It is imported by
  5050   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5051   can be used like any other Isabelle image.  See
  5052   HOL/Import/HOL/README for more information.
  5053 
  5054 * Simplifier:
  5055   - Much improved handling of linear and partial orders.
  5056     Reasoners for linear and partial orders are set up for type classes
  5057     "linorder" and "order" respectively, and are added to the default simpset
  5058     as solvers.  This means that the simplifier can build transitivity chains
  5059     to solve goals from the assumptions.
  5060   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5061     of blast or auto after simplification become unnecessary because the goal
  5062     is solved by simplification already.
  5063 
  5064 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5065     all proved in axiomatic type classes for semirings, rings and fields.
  5066 
  5067 * Numerics:
  5068   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5069     now formalized using the Ring_and_Field theory mentioned above.
  5070   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5071     than before, because now they are set up once in a generic manner.
  5072   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5073     Look for the general versions in Ring_and_Field (and Power if they concern
  5074     exponentiation).
  5075 
  5076 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5077 
  5078 * Records:
  5079   - Record types are now by default printed with their type abbreviation
  5080     instead of the list of all field types. This can be configured via
  5081     the reference "print_record_type_abbr".
  5082   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5083     (not enabled by default).
  5084   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5085     EX x. x = sel r to True (not enabled by default).
  5086   - Tactic "record_split_simp_tac" to split and simplify records added.
  5087 
  5088 * 'specification' command added, allowing for definition by
  5089   specification.  There is also an 'ax_specification' command that
  5090   introduces the new constants axiomatically.
  5091 
  5092 * arith(_tac) is now able to generate counterexamples for reals as well.
  5093 
  5094 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5095 
  5096 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5097   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5098 
  5099 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5100   matrix theory to linear programming.
  5101 
  5102 * Unions and Intersections:
  5103   The latex output syntax of UN and INT has been changed
  5104   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5105   i.e. the index formulae has become a subscript.
  5106   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5107 
  5108 * Unions and Intersections over Intervals:
  5109   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5110   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5111   like in normal math, and corresponding versions for < and for intersection.
  5112 
  5113 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5114   lexicographic dictonary ordering has been added as "lexord".
  5115 
  5116 * ML: the legacy theory structures Int and List have been removed. They had
  5117   conflicted with ML Basis Library structures having the same names.
  5118 
  5119 * 'refute' command added to search for (finite) countermodels.  Only works
  5120   for a fragment of HOL.  The installation of an external SAT solver is
  5121   highly recommended.  See "HOL/Refute.thy" for details.
  5122 
  5123 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5124   formulae under an assignment of free variables to random values.
  5125   In contrast to 'refute', it can deal with inductive datatypes,
  5126   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5127   for examples.
  5128 
  5129 
  5130 *** HOLCF ***
  5131 
  5132 * Streams now come with concatenation and are part of the HOLCF image
  5133 
  5134 
  5135 
  5136 New in Isabelle2003 (May 2003)
  5137 ------------------------------
  5138 
  5139 *** General ***
  5140 
  5141 * Provers/simplifier:
  5142 
  5143   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5144     Assumptions are now subject to complete mutual simplification,
  5145     not just from left to right. The simplifier now preserves
  5146     the order of assumptions.
  5147 
  5148     Potential INCOMPATIBILITY:
  5149 
  5150     -- simp sometimes diverges where the old version did
  5151        not, e.g. invoking simp on the goal
  5152 
  5153         [| P (f x); y = x; f x = f y |] ==> Q
  5154 
  5155        now gives rise to the infinite reduction sequence
  5156 
  5157         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5158 
  5159        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5160        kind of problem.
  5161 
  5162     -- Tactics combining classical reasoner and simplification (such as auto)
  5163        are also affected by this change, because many of them rely on
  5164        simp. They may sometimes diverge as well or yield a different numbers
  5165        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5166        in case of problems. Sometimes subsequent calls to the classical
  5167        reasoner will fail because a preceeding call to the simplifier too
  5168        eagerly simplified the goal, e.g. deleted redundant premises.
  5169 
  5170   - The simplifier trace now shows the names of the applied rewrite rules
  5171 
  5172   - You can limit the number of recursive invocations of the simplifier
  5173     during conditional rewriting (where the simplifie tries to solve the
  5174     conditions before applying the rewrite rule):
  5175     ML "simp_depth_limit := n"
  5176     where n is an integer. Thus you can force termination where previously
  5177     the simplifier would diverge.
  5178 
  5179   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5180 
  5181   - No longer aborts on failed congruence proof.  Instead, the
  5182     congruence is ignored.
  5183 
  5184 * Pure: New generic framework for extracting programs from constructive
  5185   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5186   as HOL/Extraction for some case studies.
  5187 
  5188 * Pure: The main goal of the proof state is no longer shown by default, only
  5189 the subgoals. This behaviour is controlled by a new flag.
  5190    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5191 (ML: Proof.show_main_goal).
  5192 
  5193 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5194 rules whose conclusion matches subgoal 1:
  5195       PG menu: Isabelle/Isar -> Show me -> matching rules
  5196 The rules are ordered by how closely they match the subgoal.
  5197 In particular, rules that solve a subgoal outright are displayed first
  5198 (or rather last, the way they are printed).
  5199 (ML: ProofGeneral.print_intros())
  5200 
  5201 * Pure: New flag trace_unify_fail causes unification to print
  5202 diagnostic information (PG: in trace buffer) when it fails. This is
  5203 useful for figuring out why single step proofs like rule, erule or
  5204 assumption failed.
  5205 
  5206 * Pure: Locale specifications now produce predicate definitions
  5207 according to the body of text (covering assumptions modulo local
  5208 definitions); predicate "loc_axioms" covers newly introduced text,
  5209 while "loc" is cumulative wrt. all included locale expressions; the
  5210 latter view is presented only on export into the global theory
  5211 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5212 on the old view without predicates;
  5213 
  5214 * Pure: predefined locales "var" and "struct" are useful for sharing
  5215 parameters (as in CASL, for example); just specify something like
  5216 ``var x + var y + struct M'' as import;
  5217 
  5218 * Pure: improved thms_containing: proper indexing of facts instead of
  5219 raw theorems; check validity of results wrt. current name space;
  5220 include local facts of proof configuration (also covers active
  5221 locales), cover fixed variables in index; may use "_" in term
  5222 specification; an optional limit for the number of printed facts may
  5223 be given (the default is 40);
  5224 
  5225 * Pure: disallow duplicate fact bindings within new-style theory files
  5226 (batch-mode only);
  5227 
  5228 * Provers: improved induct method: assumptions introduced by case
  5229 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5230 the goal statement); "foo" still refers to all facts collectively;
  5231 
  5232 * Provers: the function blast.overloaded has been removed: all constants
  5233 are regarded as potentially overloaded, which improves robustness in exchange
  5234 for slight decrease in efficiency;
  5235 
  5236 * Provers/linorder: New generic prover for transitivity reasoning over
  5237 linear orders.  Note: this prover is not efficient!
  5238 
  5239 * Isar: preview of problems to finish 'show' now produce an error
  5240 rather than just a warning (in interactive mode);
  5241 
  5242 
  5243 *** HOL ***
  5244 
  5245 * arith(_tac)
  5246 
  5247  - Produces a counter example if it cannot prove a goal.
  5248    Note that the counter example may be spurious if the goal is not a formula
  5249    of quantifier-free linear arithmetic.
  5250    In ProofGeneral the counter example appears in the trace buffer.
  5251 
  5252  - Knows about div k and mod k where k is a numeral of type nat or int.
  5253 
  5254  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5255    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5256    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5257 
  5258 * simp's arithmetic capabilities have been enhanced a bit: it now
  5259 takes ~= in premises into account (by performing a case split);
  5260 
  5261 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5262 are distributed over a sum of terms;
  5263 
  5264 * New tactic "trans_tac" and method "trans" instantiate
  5265 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5266 "<=", "<" and "=").
  5267 
  5268 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5269 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5270 
  5271 * 'typedef' command has new option "open" to suppress the set
  5272 definition;
  5273 
  5274 * functions Min and Max on finite sets have been introduced (theory
  5275 Finite_Set);
  5276 
  5277 * attribute [symmetric] now works for relations as well; it turns
  5278 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5279 
  5280 * induct over a !!-quantified statement (say !!x1..xn):
  5281   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5282 
  5283 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5284 %x. None. Warning: empty_def now refers to the previously hidden definition
  5285 of the empty set.
  5286 
  5287 * Algebra: formalization of classical algebra.  Intended as base for
  5288 any algebraic development in Isabelle.  Currently covers group theory
  5289 (up to Sylow's theorem) and ring theory (Universal Property of
  5290 Univariate Polynomials).  Contributions welcome;
  5291 
  5292 * GroupTheory: deleted, since its material has been moved to Algebra;
  5293 
  5294 * Complex: new directory of the complex numbers with numeric constants,
  5295 nonstandard complex numbers, and some complex analysis, standard and
  5296 nonstandard (Jacques Fleuriot);
  5297 
  5298 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5299 
  5300 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5301 Fleuriot);
  5302 
  5303 * Real/HahnBanach: updated and adapted to locales;
  5304 
  5305 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5306 Gray and Kramer);
  5307 
  5308 * UNITY: added the Meier-Sanders theory of progress sets;
  5309 
  5310 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5311 as abstract algorithms, instantiated to the JVM;
  5312 
  5313 * Bali: Java source language formalization. Type system, operational
  5314 semantics, axiomatic semantics. Supported language features:
  5315 classes, interfaces, objects,virtual methods, static methods,
  5316 static/instance fields, arrays, access modifiers, definite
  5317 assignment, exceptions.
  5318 
  5319 
  5320 *** ZF ***
  5321 
  5322 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5323 universe, etc.);
  5324 
  5325 * Main ZF: virtually all theories converted to new-style format;
  5326 
  5327 
  5328 *** ML ***
  5329 
  5330 * Pure: Tactic.prove provides sane interface for internal proofs;
  5331 omits the infamous "standard" operation, so this is more appropriate
  5332 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5333 
  5334 * Pure: improved error reporting of simprocs;
  5335 
  5336 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5337 up simprocs;
  5338 
  5339 
  5340 *** Document preparation ***
  5341 
  5342 * uses \par instead of \\ for line breaks in theory text. This may
  5343 shift some page breaks in large documents. To get the old behaviour
  5344 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5345 
  5346 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5347 other packages
  5348 
  5349 * \<euro> now needs package babel/greek instead of marvosym (which
  5350 broke \Rightarrow)
  5351 
  5352 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5353 textcomp package)
  5354 
  5355 
  5356 
  5357 New in Isabelle2002 (March 2002)
  5358 --------------------------------
  5359 
  5360 *** Document preparation ***
  5361 
  5362 * greatly simplified document preparation setup, including more
  5363 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5364 instructive isatool mkdir; users should basically be able to get
  5365 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5366 users may run a separate document processing stage manually like this:
  5367 "isatool usedir -D output HOL Test && isatool document Test/output";
  5368 
  5369 * theory dependency graph may now be incorporated into documents;
  5370 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5371 with \includegraphics of LaTeX;
  5372 
  5373 * proper spacing of consecutive markup elements, especially text
  5374 blocks after section headings;
  5375 
  5376 * support bold style (for single symbols only), input syntax is like
  5377 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5378 
  5379 * \<bullet> is now output as bold \cdot by default, which looks much
  5380 better in printed text;
  5381 
  5382 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5383 note that these symbols are currently unavailable in Proof General /
  5384 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5385 
  5386 * isatool latex no longer depends on changed TEXINPUTS, instead
  5387 isatool document copies the Isabelle style files to the target
  5388 location;
  5389 
  5390 
  5391 *** Isar ***
  5392 
  5393 * Pure/Provers: improved proof by cases and induction;
  5394   - 'case' command admits impromptu naming of parameters (such as
  5395     "case (Suc n)");
  5396   - 'induct' method divinates rule instantiation from the inductive
  5397     claim; no longer requires excessive ?P bindings for proper
  5398     instantiation of cases;
  5399   - 'induct' method properly enumerates all possibilities of set/type
  5400     rules; as a consequence facts may be also passed through *type*
  5401     rules without further ado;
  5402   - 'induct' method now derives symbolic cases from the *rulified*
  5403     rule (before it used to rulify cases stemming from the internal
  5404     atomized version); this means that the context of a non-atomic
  5405     statement becomes is included in the hypothesis, avoiding the
  5406     slightly cumbersome show "PROP ?case" form;
  5407   - 'induct' may now use elim-style induction rules without chaining
  5408     facts, using ``missing'' premises from the goal state; this allows
  5409     rules stemming from inductive sets to be applied in unstructured
  5410     scripts, while still benefitting from proper handling of non-atomic
  5411     statements; NB: major inductive premises need to be put first, all
  5412     the rest of the goal is passed through the induction;
  5413   - 'induct' proper support for mutual induction involving non-atomic
  5414     rule statements (uses the new concept of simultaneous goals, see
  5415     below);
  5416   - append all possible rule selections, but only use the first
  5417     success (no backtracking);
  5418   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5419   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5420   - added 'print_induct_rules' (covered by help item in recent Proof
  5421     General versions);
  5422   - moved induct/cases attributes to Pure, methods to Provers;
  5423   - generic method setup instantiated for FOL and HOL;
  5424 
  5425 * Pure: support multiple simultaneous goal statements, for example
  5426 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5427 meta-level mechanism, this acts as if several individual goals had
  5428 been stated separately; in particular common proof methods need to be
  5429 repeated in order to cover all claims; note that a single elimination
  5430 step is *not* sufficient to establish the two conjunctions, so this
  5431 fails:
  5432 
  5433   assume "A & B" then have A and B ..   (*".." fails*)
  5434 
  5435 better use "obtain" in situations as above; alternative refer to
  5436 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5437 
  5438 * Pure: proper integration with ``locales''; unlike the original
  5439 version by Florian Kammller, Isar locales package high-level proof
  5440 contexts rather than raw logical ones (e.g. we admit to include
  5441 attributes everywhere); operations on locales include merge and
  5442 rename; support for implicit arguments (``structures''); simultaneous
  5443 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5444 some examples;
  5445 
  5446 * Pure: the following commands have been ``localized'', supporting a
  5447 target locale specification "(in name)": 'lemma', 'theorem',
  5448 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5449 stored both within the locale and at the theory level (exported and
  5450 qualified by the locale name);
  5451 
  5452 * Pure: theory goals may now be specified in ``long'' form, with
  5453 ad-hoc contexts consisting of arbitrary locale elements. for example
  5454 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5455 definitions may be given, too); the result is a meta-level rule with
  5456 the context elements being discharged in the obvious way;
  5457 
  5458 * Pure: new proof command 'using' allows to augment currently used
  5459 facts after a goal statement ('using' is syntactically analogous to
  5460 'apply', but acts on the goal's facts only); this allows chained facts
  5461 to be separated into parts given before and after a claim, as in
  5462 ``from a and b have C using d and e <proof>'';
  5463 
  5464 * Pure: renamed "antecedent" case to "rule_context";
  5465 
  5466 * Pure: new 'judgment' command records explicit information about the
  5467 object-logic embedding (used by several tools internally); no longer
  5468 use hard-wired "Trueprop";
  5469 
  5470 * Pure: added 'corollary' command;
  5471 
  5472 * Pure: fixed 'token_translation' command;
  5473 
  5474 * Pure: removed obsolete 'exported' attribute;
  5475 
  5476 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5477 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5478 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5479 
  5480 * Pure: method 'atomize' presents local goal premises as object-level
  5481 statements (atomic meta-level propositions); setup controlled via
  5482 rewrite rules declarations of 'atomize' attribute; example
  5483 application: 'induct' method with proper rule statements in improper
  5484 proof *scripts*;
  5485 
  5486 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5487 now consider the syntactic context of assumptions, giving a better
  5488 chance to get type-inference of the arguments right (this is
  5489 especially important for locales);
  5490 
  5491 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5492 mode;
  5493 
  5494 * Pure/obtain: the formal conclusion "thesis", being marked as
  5495 ``internal'', may no longer be reference directly in the text;
  5496 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5497 situations;
  5498 
  5499 * Pure: generic 'sym' attribute which declares a rule both as pure
  5500 'elim?' and for the 'symmetric' operation;
  5501 
  5502 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5503 text; the fixed correlation with particular command syntax has been
  5504 discontinued;
  5505 
  5506 * Pure: new method 'rules' is particularly well-suited for proof
  5507 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5508 but often produces more compact proof terms with less detours;
  5509 
  5510 * Pure/Provers/classical: simplified integration with pure rule
  5511 attributes and methods; the classical "intro?/elim?/dest?"
  5512 declarations coincide with the pure ones; the "rule" method no longer
  5513 includes classically swapped intros; "intro" and "elim" methods no
  5514 longer pick rules from the context; also got rid of ML declarations
  5515 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5516 INCOMPATIBILITY;
  5517 
  5518 * Provers/classical: attribute 'swapped' produces classical inversions
  5519 of introduction rules;
  5520 
  5521 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5522 rules instead of full simplifier context; 'iff' attribute handles
  5523 conditional rules;
  5524 
  5525 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5526 
  5527 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5528 "(permissive)" option to recover old behavior;
  5529 
  5530 * HOL: 'inductive' no longer features separate (collective) attributes
  5531 for 'intros' (was found too confusing);
  5532 
  5533 * HOL: properly declared induction rules less_induct and
  5534 wf_induct_rule;
  5535 
  5536 
  5537 *** HOL ***
  5538 
  5539 * HOL: moved over to sane numeral syntax; the new policy is as
  5540 follows:
  5541 
  5542   - 0 and 1 are polymorphic constants, which are defined on any
  5543   numeric type (nat, int, real etc.);
  5544 
  5545   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5546   binary representation internally;
  5547 
  5548   - type nat has special constructor Suc, and generally prefers Suc 0
  5549   over 1::nat and Suc (Suc 0) over 2::nat;
  5550 
  5551 This change may cause significant problems of INCOMPATIBILITY; here
  5552 are some hints on converting existing sources:
  5553 
  5554   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5555   entities, so expressions involving "-" (unary or binary minus) need
  5556   to be spaced properly;
  5557 
  5558   - existing occurrences of "1" may need to be constraint "1::nat" or
  5559   even replaced by Suc 0; similar for old "2";
  5560 
  5561   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5562 
  5563   - remove all special provisions on numerals in proofs;
  5564 
  5565 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5566 representation (depends on bin_arith_simps in the default context);
  5567 
  5568 * HOL: symbolic syntax for x^2 (numeral 2);
  5569 
  5570 * HOL: the class of all HOL types is now called "type" rather than
  5571 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5572 in axclass/classes, instance/arities, and (usually rare) occurrences
  5573 in typings (of consts etc.); internally the class is called
  5574 "HOL.type", ML programs should refer to HOLogic.typeS;
  5575 
  5576 * HOL/record package improvements:
  5577   - new derived operations "fields" to build a partial record section,
  5578     "extend" to promote a fixed record to a record scheme, and
  5579     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5580     declared as simp by default;
  5581   - shared operations ("more", "fields", etc.) now need to be always
  5582     qualified) --- potential INCOMPATIBILITY;
  5583   - removed "make_scheme" operations (use "make" with "extend") --
  5584     INCOMPATIBILITY;
  5585   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5586   - provides cases/induct rules for use with corresponding Isar
  5587     methods (for concrete records, record schemes, concrete more
  5588     parts, and schematic more parts -- in that order);
  5589   - internal definitions directly based on a light-weight abstract
  5590     theory of product types over typedef rather than datatype;
  5591 
  5592 * HOL: generic code generator for generating executable ML code from
  5593 specifications; specific support for HOL constructs such as inductive
  5594 datatypes and sets, as well as recursive functions; can be invoked
  5595 via 'generate_code' theory section;
  5596 
  5597 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5598 
  5599 * HOL: consolidated and renamed several theories.  In particular:
  5600         Ord.thy has been absorbed into HOL.thy
  5601         String.thy has been absorbed into List.thy
  5602 
  5603 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5604 (beware of argument permutation!);
  5605 
  5606 * HOL: linorder_less_split superseded by linorder_cases;
  5607 
  5608 * HOL/List: "nodups" renamed to "distinct";
  5609 
  5610 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5611 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5612   - Ex_def has changed, now need to use some_eq_ex
  5613 
  5614 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5615 in this (rare) case use:
  5616 
  5617   delSWrapper "split_all_tac"
  5618   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5619 
  5620 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5621 MAY FAIL;
  5622 
  5623 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5624 Isabelle's type classes, ^ on functions and relations has too general
  5625 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5626 necessary to attach explicit type constraints;
  5627 
  5628 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5629 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5630 renamed accordingly (eg "compI" -> "rel_compI").
  5631 
  5632 * HOL: syntax translations now work properly with numerals and records
  5633 expressions;
  5634 
  5635 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5636 of "lam" -- INCOMPATIBILITY;
  5637 
  5638 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5639 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5640 renamed "Product_Type.unit";
  5641 
  5642 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5643 
  5644 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5645 the "cases" method);
  5646 
  5647 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5648 Florian Kammller);
  5649 
  5650 * HOL/IMP: updated and converted to new-style theory format; several
  5651 parts turned into readable document, with proper Isar proof texts and
  5652 some explanations (by Gerwin Klein);
  5653 
  5654 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5655 
  5656 * HOL-Hyperreal is now a logic image;
  5657 
  5658 
  5659 *** HOLCF ***
  5660 
  5661 * Isar: consts/constdefs supports mixfix syntax for continuous
  5662 operations;
  5663 
  5664 * Isar: domain package adapted to new-style theory format, e.g. see
  5665 HOLCF/ex/Dnat.thy;
  5666 
  5667 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5668 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5669 lift.induct_tac, always use UU instead of Undef;
  5670 
  5671 * HOLCF/IMP: updated and converted to new-style theory;
  5672 
  5673 
  5674 *** ZF ***
  5675 
  5676 * Isar: proper integration of logic-specific tools and packages,
  5677 including theory commands '(co)inductive', '(co)datatype',
  5678 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5679 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5680 
  5681 * theory Main no longer includes AC; for the Axiom of Choice, base
  5682 your theory on Main_ZFC;
  5683 
  5684 * the integer library now covers quotients and remainders, with many
  5685 laws relating division to addition, multiplication, etc.;
  5686 
  5687 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5688 typeless version of the formalism;
  5689 
  5690 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5691 format;
  5692 
  5693 * ZF/Induct: new directory for examples of inductive definitions,
  5694 including theory Multiset for multiset orderings; converted to
  5695 new-style theory format;
  5696 
  5697 * ZF: many new theorems about lists, ordinals, etc.;
  5698 
  5699 
  5700 *** General ***
  5701 
  5702 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5703 variable proof controls level of detail: 0 = no proofs (only oracle
  5704 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5705 also ref manual for further ML interfaces;
  5706 
  5707 * Pure/axclass: removed obsolete ML interface
  5708 goal_subclass/goal_arity;
  5709 
  5710 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5711 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5712 separate tokens, so expressions involving minus need to be spaced
  5713 properly;
  5714 
  5715 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5716 rather than "infixl" or "infixr";
  5717 
  5718 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5719 sort constraint specifications in type inference; e.g. "x::_::foo"
  5720 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5721 type variable);
  5722 
  5723 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5724 control output of nested => (types); the default behavior is
  5725 "type_brackets";
  5726 
  5727 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5728 tokens into AST constants;
  5729 
  5730 * Pure/syntax: prefer later declarations of translations and print
  5731 translation functions; potential INCOMPATIBILITY: need to reverse
  5732 multiple declarations for same syntax element constant;
  5733 
  5734 * Pure/show_hyps reset by default (in accordance to existing Isar
  5735 practice);
  5736 
  5737 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5738 addSafter;
  5739 
  5740 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5741 as well;
  5742 
  5743 * system: tested support for MacOS X; should be able to get Isabelle +
  5744 Proof General to work in a plain Terminal after installing Poly/ML
  5745 (e.g. from the Isabelle distribution area) and GNU bash alone
  5746 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5747 support requires further installations, e.g. from
  5748 http://fink.sourceforge.net/);
  5749 
  5750 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5751 
  5752 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5753 of 40 MB), cf. ML_OPTIONS;
  5754 
  5755 * system: Proof General keywords specification is now part of the
  5756 Isabelle distribution (see etc/isar-keywords.el);
  5757 
  5758 * system: support for persistent Proof General sessions (refrain from
  5759 outdating all loaded theories on startup); user may create writable
  5760 logic images like this: ``isabelle -q HOL Test'';
  5761 
  5762 * system: smart selection of Isabelle process versus Isabelle
  5763 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5764 run both "isabelle" and "Isabelle" even if file names are badly
  5765 damaged (executable inspects the case of the first letter of its own
  5766 name); added separate "isabelle-process" and "isabelle-interface";
  5767 
  5768 * system: refrain from any attempt at filtering input streams; no
  5769 longer support ``8bit'' encoding of old isabelle font, instead proper
  5770 iso-latin characters may now be used; the related isatools
  5771 "symbolinput" and "nonascii" have disappeared as well;
  5772 
  5773 * system: removed old "xterm" interface (the print modes "xterm" and
  5774 "xterm_color" are still available for direct use in a suitable
  5775 terminal);
  5776 
  5777 
  5778 
  5779 New in Isabelle99-2 (February 2001)
  5780 -----------------------------------
  5781 
  5782 *** Overview of INCOMPATIBILITIES ***
  5783 
  5784 * HOL: please note that theories in the Library and elsewhere often use the
  5785 new-style (Isar) format; to refer to their theorems in an ML script you must
  5786 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5787 
  5788 * HOL: inductive package no longer splits induction rule aggressively,
  5789 but only as far as specified by the introductions given; the old
  5790 format may be recovered via ML function complete_split_rule or attribute
  5791 'split_rule (complete)';
  5792 
  5793 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5794 gfp_Tarski to gfp_unfold;
  5795 
  5796 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5797 
  5798 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5799 relation); infix "^^" has been renamed "``"; infix "``" has been
  5800 renamed "`"; "univalent" has been renamed "single_valued";
  5801 
  5802 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5803 operation;
  5804 
  5805 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5806 
  5807 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5808 
  5809 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5810 consequence, it is no longer monotonic wrt. the local goal context
  5811 (which is now passed through the inductive cases);
  5812 
  5813 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5814 \<gg> to \<ggreater>;
  5815 
  5816 
  5817 *** Document preparation ***
  5818 
  5819 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5820 available: are "it" for near math-mode best-style output, "sl" for
  5821 slanted text style, and "tt" for plain type-writer; if no
  5822 \isabellestyle command is given, output is according to slanted
  5823 type-writer);
  5824 
  5825 * support sub/super scripts (for single symbols only), input syntax is
  5826 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5827 
  5828 * some more standard symbols; see Appendix A of the system manual for
  5829 the complete list of symbols defined in isabellesym.sty;
  5830 
  5831 * improved isabelle style files; more abstract symbol implementation
  5832 (should now use \isamath{...} and \isatext{...} in custom symbol
  5833 definitions);
  5834 
  5835 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5836 state; Note that presentation of goal states does not conform to
  5837 actual human-readable proof documents.  Please do not include goal
  5838 states into document output unless you really know what you are doing!
  5839 
  5840 * proper indentation of antiquoted output with proportional LaTeX
  5841 fonts;
  5842 
  5843 * no_document ML operator temporarily disables LaTeX document
  5844 generation;
  5845 
  5846 * isatool unsymbolize tunes sources for plain ASCII communication;
  5847 
  5848 
  5849 *** Isar ***
  5850 
  5851 * Pure: Isar now suffers initial goal statements to contain unbound
  5852 schematic variables (this does not conform to actual readable proof
  5853 documents, due to unpredictable outcome and non-compositional proof
  5854 checking); users who know what they are doing may use schematic goals
  5855 for Prolog-style synthesis of proven results;
  5856 
  5857 * Pure: assumption method (an implicit finishing) now handles actual
  5858 rules as well;
  5859 
  5860 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5861 initial goal, declare "that" only as Pure intro (only for single
  5862 steps); the "that" rule assumption may now be involved in implicit
  5863 finishing, thus ".." becomes a feasible for trivial obtains;
  5864 
  5865 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5866 instance proofs may be performed by "..";
  5867 
  5868 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5869 statements as well;
  5870 
  5871 * Pure: more robust selection of calculational rules;
  5872 
  5873 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5874 rule (as well as the assumption rule);
  5875 
  5876 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5877 lemmas, using the graph browser tool;
  5878 
  5879 * Pure: predict failure of "show" in interactive mode;
  5880 
  5881 * Pure: 'thms_containing' now takes actual terms as arguments;
  5882 
  5883 * HOL: improved method 'induct' --- now handles non-atomic goals
  5884 (potential INCOMPATIBILITY); tuned error handling;
  5885 
  5886 * HOL: cases and induct rules now provide explicit hints about the
  5887 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5888 any remaining facts are inserted into the goal verbatim;
  5889 
  5890 * HOL: local contexts (aka cases) may now contain term bindings as
  5891 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5892 the result to be shown in each case;
  5893 
  5894 * HOL: added 'recdef_tc' command;
  5895 
  5896 * isatool convert assists in eliminating legacy ML scripts;
  5897 
  5898 
  5899 *** HOL ***
  5900 
  5901 * HOL/Library: a collection of generic theories to be used together
  5902 with main HOL; the theory loader path already includes this directory
  5903 by default; the following existing theories have been moved here:
  5904 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5905 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5906 
  5907 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5908 modelling and verification task performed in Isabelle/HOL +
  5909 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5910 
  5911 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5912 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5913 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5914 'domain', this makes the theory consistent with mathematical
  5915 literature;
  5916 
  5917 * HOL basics: added overloaded operations "inverse" and "divide"
  5918 (infix "/"), syntax for generic "abs" operation, generic summation
  5919 operator \<Sum>;
  5920 
  5921 * HOL/typedef: simplified package, provide more useful rules (see also
  5922 HOL/subset.thy);
  5923 
  5924 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5925 now expressed as a proper nested rule (old-style tactic scripts may
  5926 require atomize_strip_tac to cope with non-atomic premises);
  5927 
  5928 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5929 to "split_conv" (old name still available for compatibility);
  5930 
  5931 * HOL: improved concrete syntax for strings (e.g. allows translation
  5932 rules with string literals);
  5933 
  5934 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5935  and Fleuriot's mechanization of analysis, including the transcendental
  5936  functions for the reals;
  5937 
  5938 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5939 
  5940 
  5941 *** CTT ***
  5942 
  5943 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5944 "lam" is displayed as TWO lambda-symbols
  5945 
  5946 * CTT: theory Main now available, containing everything (that is, Bool
  5947 and Arith);
  5948 
  5949 
  5950 *** General ***
  5951 
  5952 * Pure: the Simplifier has been implemented properly as a derived rule
  5953 outside of the actual kernel (at last!); the overall performance
  5954 penalty in practical applications is about 50%, while reliability of
  5955 the Isabelle inference kernel has been greatly improved;
  5956 
  5957 * print modes "brackets" and "no_brackets" control output of nested =>
  5958 (types) and ==> (props); the default behaviour is "brackets";
  5959 
  5960 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5961 as assumptions as well;
  5962 
  5963 * system: support Poly/ML 4.0;
  5964 
  5965 * system: isatool install handles KDE version 1 or 2;
  5966 
  5967 
  5968 
  5969 New in Isabelle99-1 (October 2000)
  5970 ----------------------------------
  5971 
  5972 *** Overview of INCOMPATIBILITIES ***
  5973 
  5974 * HOL: simplification of natural numbers is much changed; to partly
  5975 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5976 issue the following ML commands:
  5977 
  5978   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5979   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5980 
  5981 * HOL: simplification no longer dives into case-expressions; this is
  5982 controlled by "t.weak_case_cong" for each datatype t;
  5983 
  5984 * HOL: nat_less_induct renamed to less_induct;
  5985 
  5986 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5987 fixsome to patch .thy and .ML sources automatically;
  5988 
  5989   select_equality  -> some_equality
  5990   select_eq_Ex     -> some_eq_ex
  5991   selectI2EX       -> someI2_ex
  5992   selectI2         -> someI2
  5993   selectI          -> someI
  5994   select1_equality -> some1_equality
  5995   Eps_sym_eq       -> some_sym_eq_trivial
  5996   Eps_eq           -> some_eq_trivial
  5997 
  5998 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5999 
  6000 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6001 instead);
  6002 
  6003 * HOL: the recursion equations generated by 'recdef' are now called
  6004 f.simps instead of f.rules;
  6005 
  6006 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6007 
  6008 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6009 sometimes be needed;
  6010 
  6011 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6012 
  6013 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6014 
  6015 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6016 product is now "<*>" instead of "Times"; the lexicographic product is
  6017 now "<*lex*>" instead of "**";
  6018 
  6019 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6020 of main HOL, but was unused); better use HOL's datatype package;
  6021 
  6022 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6023 the old syntax may be recovered as follows:
  6024 
  6025   syntax (symbols)
  6026     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6027       (infixl "\\<oplus>" 100)
  6028 
  6029 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6030 
  6031 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6032 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6033 internally;
  6034 
  6035 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6036 changed from A/r to A//r;
  6037 
  6038 * ZF: new treatment of arithmetic (nat & int) may break some old
  6039 proofs;
  6040 
  6041 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6042 rulify -> rule_format, elimify -> elim_format, ...);
  6043 
  6044 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6045 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6046 should have to change intro!! to intro? only); replaced "delrule" by
  6047 "rule del";
  6048 
  6049 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6050 
  6051 * Provers: strengthened force_tac by using new first_best_tac;
  6052 
  6053 * LaTeX document preparation: several changes of isabelle.sty (see
  6054 lib/texinputs);
  6055 
  6056 
  6057 *** Document preparation ***
  6058 
  6059 * formal comments (text blocks etc.) in new-style theories may now
  6060 contain antiquotations of thm/prop/term/typ/text to be presented
  6061 according to latex print mode; concrete syntax is like this:
  6062 @{term[show_types] "f(x) = a + x"};
  6063 
  6064 * isatool mkdir provides easy setup of Isabelle session directories,
  6065 including proper document sources;
  6066 
  6067 * generated LaTeX sources are now deleted after successful run
  6068 (isatool document -c); may retain a copy somewhere else via -D option
  6069 of isatool usedir;
  6070 
  6071 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6072 style files, achieving self-contained LaTeX sources and simplifying
  6073 LaTeX debugging;
  6074 
  6075 * old-style theories now produce (crude) LaTeX output as well;
  6076 
  6077 * browser info session directories are now self-contained (may be put
  6078 on WWW server seperately); improved graphs of nested sessions; removed
  6079 graph for 'all sessions';
  6080 
  6081 * several improvements in isabelle style files; \isabellestyle{it}
  6082 produces fake math mode output; \isamarkupheader is now \section by
  6083 default; see lib/texinputs/isabelle.sty etc.;
  6084 
  6085 
  6086 *** Isar ***
  6087 
  6088 * Isar/Pure: local results and corresponding term bindings are now
  6089 subject to Hindley-Milner polymorphism (similar to ML); this
  6090 accommodates incremental type-inference very nicely;
  6091 
  6092 * Isar/Pure: new derived language element 'obtain' supports
  6093 generalized existence reasoning;
  6094 
  6095 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6096 support accumulation of results, without applying any rules yet;
  6097 useful to collect intermediate results without explicit name
  6098 references, and for use with transitivity rules with more than 2
  6099 premises;
  6100 
  6101 * Isar/Pure: scalable support for case-analysis type proofs: new
  6102 'case' language element refers to local contexts symbolically, as
  6103 produced by certain proof methods; internally, case names are attached
  6104 to theorems as "tags";
  6105 
  6106 * Isar/Pure: theory command 'hide' removes declarations from
  6107 class/type/const name spaces;
  6108 
  6109 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6110 indicate potential overloading;
  6111 
  6112 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6113 
  6114 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6115 "{a,b,c}" instead of {a,b,c};
  6116 
  6117 * Isar/Pure now provides its own version of intro/elim/dest
  6118 attributes; useful for building new logics, but beware of confusion
  6119 with the version in Provers/classical;
  6120 
  6121 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6122 case name 'antecedent';
  6123 
  6124 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6125 to the current context is now done automatically);
  6126 
  6127 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6128 for definining proof methods in ML;
  6129 
  6130 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6131 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6132 most cases, one should have to change intro!! to intro? only);
  6133 replaced "delrule" by "rule del";
  6134 
  6135 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6136 'symmetric' attribute (the latter supercedes [RS sym]);
  6137 
  6138 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6139 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6140 well (including splits);
  6141 
  6142 * Isar/Provers: Simplifier and Classical methods now support all kind
  6143 of modifiers used in the past, including 'cong', 'iff', etc.
  6144 
  6145 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6146 of Simplifier and Classical reasoner);
  6147 
  6148 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6149 now support named cases; major packages (inductive, datatype, primrec,
  6150 recdef) support case names and properly name parameters;
  6151 
  6152 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6153 monotonicity conditions are extracted to be proven at end of
  6154 calculations;
  6155 
  6156 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6157 method anyway;
  6158 
  6159 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6160 split_if split_if_asm; datatype package provides theorems foo.splits =
  6161 foo.split foo.split_asm for each datatype;
  6162 
  6163 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6164 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6165 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6166 use "(cases (simplified))" method in proper proof texts);
  6167 
  6168 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6169 
  6170 * Isar: names of theorems etc. may be natural numbers as well;
  6171 
  6172 * Isar: 'pr' command: optional arguments for goals_limit and
  6173 ProofContext.prems_limit; no longer prints theory contexts, but only
  6174 proof states;
  6175 
  6176 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6177 additional print modes to be specified; e.g. "pr(latex)" will print
  6178 proof state according to the Isabelle LaTeX style;
  6179 
  6180 * Isar: improved support for emulating tactic scripts, including proof
  6181 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6182 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6183 (for HOL datatypes);
  6184 
  6185 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6186 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6187 'proof method scripts' have to be in depth-first order;
  6188 
  6189 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6190 
  6191 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6192 should instead use individual commands for printing items
  6193 (print_commands, print_methods etc.);
  6194 
  6195 * Isar: added 'nothing' --- the empty list of theorems;
  6196 
  6197 
  6198 *** HOL ***
  6199 
  6200 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6201 corresponding virtual machine and a specification of its bytecode
  6202 verifier and a lightweight bytecode verifier, including proofs of
  6203 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6204 Cornelia Pusch (see also the homepage of project Bali at
  6205 http://isabelle.in.tum.de/Bali/);
  6206 
  6207 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6208 Clemens Ballarin;
  6209 
  6210 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6211 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6212 Rasmussen;
  6213 
  6214 * HOL/Lattice: fundamental concepts of lattice theory and order
  6215 structures, including duals, properties of bounds versus algebraic
  6216 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6217 Theorem for complete lattices etc.; may also serve as a demonstration
  6218 for abstract algebraic reasoning using axiomatic type classes, and
  6219 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6220 
  6221 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6222 von Oheimb;
  6223 
  6224 * HOL/IMPP: extension of IMP with local variables and mutually
  6225 recursive procedures, by David von Oheimb;
  6226 
  6227 * HOL/Lambda: converted into new-style theory and document;
  6228 
  6229 * HOL/ex/Multiquote: example of multiple nested quotations and
  6230 anti-quotations -- basically a generalized version of de-Bruijn
  6231 representation; very useful in avoiding lifting of operations;
  6232 
  6233 * HOL/record: added general record equality rule to simpset; fixed
  6234 select-update simplification procedure to handle extended records as
  6235 well; admit "r" as field name;
  6236