NEWS
author nipkow
Mon Sep 13 08:43:48 2010 +0200 (2010-09-13)
changeset 39301 e1bd8a54c40f
parent 39277 f263522ab226
child 39302 d7728f65b353
permissions -rw-r--r--
added and renamed lemmas
     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 
    72 *** HOL ***
    73 
    74 * String.literal is a type, but not a datatype. INCOMPATIBILITY.
    75  
    76 * Renamed lemmas: expand_fun_eq -> ext_iff, expand_set_eq -> set_ext_iff
    77 
    78 * Renamed class eq and constant eq (for code generation) to class equal
    79 and constant equal, plus renaming of related facts and various tuning.
    80 INCOMPATIBILITY.
    81 
    82 * Scala (2.8 or higher) has been added to the target languages of
    83 the code generator.
    84 
    85 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    86 
    87 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    88 canonical names for instance definitions for functions; various improvements.
    89 INCOMPATIBILITY.
    90 
    91 * Records: logical foundation type for records do not carry a '_type' suffix
    92 any longer.  INCOMPATIBILITY.
    93 
    94 * Code generation for records: more idiomatic representation of record types.
    95 Warning: records are not covered by ancient SML code generation any longer.
    96 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    97 helps to succeed then:
    98 
    99   record 'a foo = ...
   100   ...
   101   rep_datatype foo_ext ...
   102 
   103 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   104 INCOMPATIBILITY.
   105 
   106 * Quickcheck in locales considers interpretations of that locale for
   107 counter example search.
   108 
   109 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
   110 in Library/State_Monad has been changed to avoid ambiguities.
   111 INCOMPATIBILITY.
   112 
   113 * Code generator: export_code without explicit file declaration prints
   114 to standard output.  INCOMPATIBILITY.
   115 
   116 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   117 respectively.  INCOMPATIBILITY.
   118 
   119 * Constant "split" has been merged with constant "prod_case";  names
   120 of ML functions, facts etc. involving split have been retained so far,
   121 though.  INCOMPATIBILITY.
   122 
   123 * Dropped old infix syntax "mem" for List.member;  use "in set"
   124 instead.  INCOMPATIBILITY.
   125 
   126 * Refactoring of code-generation specific operations in List.thy
   127 
   128   constants
   129     null ~> List.null
   130 
   131   facts
   132     mem_iff ~> member_def
   133     null_empty ~> null_def
   134 
   135 INCOMPATIBILITY.  Note that these were not suppossed to be used
   136 regularly unless for striking reasons;  their main purpose was code
   137 generation.
   138 
   139 * Some previously unqualified names have been qualified:
   140 
   141   types
   142     bool ~> HOL.bool
   143     nat ~> Nat.nat
   144 
   145   constants
   146     Trueprop ~> HOL.Trueprop
   147     True ~> HOL.True
   148     False ~> HOL.False
   149     op & ~> HOL.conj
   150     op | ~> HOL.disj
   151     op --> ~> HOL.implies
   152     op = ~> HOL.eq
   153     Not ~> HOL.Not
   154     The ~> HOL.The
   155     All ~> HOL.All
   156     Ex ~> HOL.Ex
   157     Ex1 ~> HOL.Ex1
   158     Let ~> HOL.Let
   159     If ~> HOL.If
   160     Ball ~> Set.Ball
   161     Bex ~> Set.Bex
   162     Suc ~> Nat.Suc
   163     Pair ~> Product_Type.Pair
   164     fst ~> Product_Type.fst
   165     snd ~> Product_Type.snd
   166     curry ~> Product_Type.curry
   167     op : ~> Set.member
   168     Collect ~> Set.Collect
   169 
   170 INCOMPATIBILITY.
   171 
   172 * Removed simplifier congruence rule of "prod_case", as has for long
   173 been the case with "split".  INCOMPATIBILITY.
   174 
   175 * Datatype package: theorems generated for executable equality
   176 (class eq) carry proper names and are treated as default code
   177 equations.
   178 
   179 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   180 INCOMPATIBILITY.
   181 
   182 * List.thy: use various operations from the Haskell prelude when
   183 generating Haskell code.
   184 
   185 * Multiset.thy: renamed empty_idemp -> empty_neutral
   186 
   187 * code_simp.ML and method code_simp: simplification with rules determined
   188 by code generator.
   189 
   190 * code generator: do not print function definitions for case
   191 combinators any longer.
   192 
   193 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   194 theorems are now stated in terms of euclidean spaces instead of finite
   195 cartesian products.
   196 
   197   types
   198     real ^ 'n ~>  'a::real_vector
   199               ~>  'a::euclidean_space
   200               ~>  'a::ordered_euclidean_space
   201         (depends on your needs)
   202 
   203   constants
   204      _ $ _        ~> _ $$ _
   205      \<chi> x. _  ~> \<chi>\<chi> x. _
   206      CARD('n)     ~> DIM('a)
   207 
   208 Also note that the indices are now natural numbers and not from some finite
   209 type. Finite cartesian products of euclidean spaces, products of euclidean
   210 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   211 
   212 INCOMPATIBILITY.
   213 
   214 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   215 as value for measures. Introduces Lebesgue Measure based on the integral in
   216 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   217 spaces.
   218 
   219  INCOMPATIBILITY.
   220 
   221 * Inductive package: offers new command "inductive_simps" to automatically
   222 derive instantiated and simplified equations for inductive predicates,
   223 similar to inductive_cases.
   224 
   225 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". surj_on is a
   226 generalization of surj, and "surj f" is now a abbreviation of "surj_on f UNIV".
   227 The theorems bij_def and surj_def are unchanged.
   228 
   229 *** FOL ***
   230 
   231 * All constant names are now qualified.  INCOMPATIBILITY.
   232 
   233 
   234 *** ZF ***
   235 
   236 * All constant names are now qualified.  INCOMPATIBILITY.
   237 
   238 
   239 *** ML ***
   240 
   241 * Configuration option show_question_marks only affects regular pretty
   242 printing of types and terms, not raw Term.string_of_vname.
   243 
   244 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   245 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   246 @{thms} for most purposes.
   247 
   248 * ML structure Unsynchronized never opened, not even in Isar
   249 interaction mode as before.  Old Unsynchronized.set etc. have been
   250 discontinued -- use plain := instead.  This should be *rare* anyway,
   251 since modern tools always work via official context data, notably
   252 configuration options.
   253 
   254 * ML antiquotations @{theory} and @{theory_ref} refer to named
   255 theories from the ancestry of the current context, not any accidental
   256 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   257 change in semantics.
   258 
   259 * Parallel and asynchronous execution requires special care concerning
   260 interrupts.  Structure Exn provides some convenience functions that
   261 avoid working directly with raw Interrupt.  User code must not absorb
   262 interrupts -- intermediate handling (for cleanup etc.) needs to be
   263 followed by re-raising of the original exception.  Another common
   264 source of mistakes are "handle _" patterns, which make the meaning of
   265 the program subject to physical effects of the environment.
   266 
   267 
   268 *** System ***
   269 
   270 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   271 
   272 
   273 
   274 New in Isabelle2009-2 (June 2010)
   275 ---------------------------------
   276 
   277 *** General ***
   278 
   279 * Authentic syntax for *all* logical entities (type classes, type
   280 constructors, term constants): provides simple and robust
   281 correspondence between formal entities and concrete syntax.  Within
   282 the parse tree / AST representations, "constants" are decorated by
   283 their category (class, type, const) and spelled out explicitly with
   284 their full internal name.
   285 
   286 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   287 and translations (translation rules and translation functions in ML).
   288 Some hints on upgrading:
   289 
   290   - Many existing uses of 'syntax' and 'translations' can be replaced
   291     by more modern 'type_notation', 'notation' and 'abbreviation',
   292     which are independent of this issue.
   293 
   294   - 'translations' require markup within the AST; the term syntax
   295     provides the following special forms:
   296 
   297       CONST c   -- produces syntax version of constant c from context
   298       XCONST c  -- literally c, checked as constant from context
   299       c         -- literally c, if declared by 'syntax'
   300 
   301     Plain identifiers are treated as AST variables -- occasionally the
   302     system indicates accidental variables via the error "rhs contains
   303     extra variables".
   304 
   305     Type classes and type constructors are marked according to their
   306     concrete syntax.  Some old translations rules need to be written
   307     for the "type" category, using type constructor application
   308     instead of pseudo-term application of the default category
   309     "logic".
   310 
   311   - 'parse_translation' etc. in ML may use the following
   312     antiquotations:
   313 
   314       @{class_syntax c}   -- type class c within parse tree / AST
   315       @{term_syntax c}    -- type constructor c within parse tree / AST
   316       @{const_syntax c}   -- ML version of "CONST c" above
   317       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   318 
   319   - Literal types within 'typed_print_translations', i.e. those *not*
   320     represented as pseudo-terms are represented verbatim.  Use @{class
   321     c} or @{type_name c} here instead of the above syntax
   322     antiquotations.
   323 
   324 Note that old non-authentic syntax was based on unqualified base
   325 names, so all of the above "constant" names would coincide.  Recall
   326 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   327 diagnose syntax problems.
   328 
   329 * Type constructors admit general mixfix syntax, not just infix.
   330 
   331 * Concrete syntax may be attached to local entities without a proof
   332 body, too.  This works via regular mixfix annotations for 'fix',
   333 'def', 'obtain' etc. or via the explicit 'write' command, which is
   334 similar to the 'notation' command in theory specifications.
   335 
   336 * Discontinued unnamed infix syntax (legacy feature for many years) --
   337 need to specify constant name and syntax separately.  Internal ML
   338 datatype constructors have been renamed from InfixName to Infix etc.
   339 Minor INCOMPATIBILITY.
   340 
   341 * Schematic theorem statements need to be explicitly markup as such,
   342 via commands 'schematic_lemma', 'schematic_theorem',
   343 'schematic_corollary'.  Thus the relevance of the proof is made
   344 syntactically clear, which impacts performance in a parallel or
   345 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   346 
   347 * Use of cumulative prems via "!" in some proof methods has been
   348 discontinued (old legacy feature).
   349 
   350 * References 'trace_simp' and 'debug_simp' have been replaced by
   351 configuration options stored in the context. Enabling tracing (the
   352 case of debugging is similar) in proofs works via
   353 
   354   using [[trace_simp = true]]
   355 
   356 Tracing is then active for all invocations of the simplifier in
   357 subsequent goal refinement steps. Tracing may also still be enabled or
   358 disabled via the ProofGeneral settings menu.
   359 
   360 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   361 'hide_fact' replace the former 'hide' KIND command.  Minor
   362 INCOMPATIBILITY.
   363 
   364 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   365 more efficient than combinations with -q1 or -q2.
   366 
   367 
   368 *** Pure ***
   369 
   370 * Proofterms record type-class reasoning explicitly, using the
   371 "unconstrain" operation internally.  This eliminates all sort
   372 constraints from a theorem and proof, introducing explicit
   373 OFCLASS-premises.  On the proof term level, this operation is
   374 automatically applied at theorem boundaries, such that closed proofs
   375 are always free of sort constraints.  INCOMPATIBILITY for tools that
   376 inspect proof terms.
   377 
   378 * Local theory specifications may depend on extra type variables that
   379 are not present in the result type -- arguments TYPE('a) :: 'a itself
   380 are added internally.  For example:
   381 
   382   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   383 
   384 * Predicates of locales introduced by classes carry a mandatory
   385 "class" prefix.  INCOMPATIBILITY.
   386 
   387 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   388 
   389 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   390 'class' instead.
   391 
   392 * Command 'code_reflect' allows to incorporate generated ML code into
   393 runtime environment; replaces immature code_datatype antiquotation.
   394 INCOMPATIBILITY.
   395 
   396 * Code generator: simple concept for abstract datatypes obeying
   397 invariants.
   398 
   399 * Code generator: details of internal data cache have no impact on the
   400 user space functionality any longer.
   401 
   402 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   403 subgoals.  This is more appropriate for interpretations with 'where'.
   404 INCOMPATIBILITY.
   405 
   406 * Command 'example_proof' opens an empty proof body.  This allows to
   407 experiment with Isar, without producing any persistent result.
   408 
   409 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   410 within a local theory context, with explicit checking of the
   411 constructors involved (in contrast to the raw 'syntax' versions).
   412 
   413 * Commands 'types' and 'typedecl' now work within a local theory
   414 context -- without introducing dependencies on parameters or
   415 assumptions, which is not possible in Isabelle/Pure.
   416 
   417 * Command 'defaultsort' has been renamed to 'default_sort', it works
   418 within a local theory context.  Minor INCOMPATIBILITY.
   419 
   420 
   421 *** HOL ***
   422 
   423 * Command 'typedef' now works within a local theory context -- without
   424 introducing dependencies on parameters or assumptions, which is not
   425 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   426 contain multiple interpretations of local typedefs (with different
   427 non-emptiness proofs), even in a global theory context.
   428 
   429 * New package for quotient types.  Commands 'quotient_type' and
   430 'quotient_definition' may be used for defining types and constants by
   431 quotient constructions.  An example is the type of integers created by
   432 quotienting pairs of natural numbers:
   433 
   434   fun
   435     intrel :: "(nat * nat) => (nat * nat) => bool"
   436   where
   437     "intrel (x, y) (u, v) = (x + v = u + y)"
   438 
   439   quotient_type int = "nat * nat" / intrel
   440     by (auto simp add: equivp_def expand_fun_eq)
   441 
   442   quotient_definition
   443     "0::int" is "(0::nat, 0::nat)"
   444 
   445 The method "lifting" can be used to lift of theorems from the
   446 underlying "raw" type to the quotient type.  The example
   447 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   448 construction and provides a reasoning infrastructure for finite sets.
   449 
   450 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   451 clash with new theory Quotient in Main HOL.
   452 
   453 * Moved the SMT binding into the main HOL session, eliminating
   454 separate HOL-SMT session.
   455 
   456 * List membership infix mem operation is only an input abbreviation.
   457 INCOMPATIBILITY.
   458 
   459 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   460 for future developements; former Library/Word.thy is still present in
   461 the AFP entry RSAPPS.
   462 
   463 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   464 longer shadowed.  INCOMPATIBILITY.
   465 
   466 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   467 INCOMPATIBILITY.
   468 
   469 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   470 INCOMPATIBILITY.
   471 
   472 * Dropped normalizing_semiring etc; use the facts in semiring classes
   473 instead.  INCOMPATIBILITY.
   474 
   475 * Dropped several real-specific versions of lemmas about floor and
   476 ceiling; use the generic lemmas from theory "Archimedean_Field"
   477 instead.  INCOMPATIBILITY.
   478 
   479   floor_number_of_eq         ~> floor_number_of
   480   le_floor_eq_number_of      ~> number_of_le_floor
   481   le_floor_eq_zero           ~> zero_le_floor
   482   le_floor_eq_one            ~> one_le_floor
   483   floor_less_eq_number_of    ~> floor_less_number_of
   484   floor_less_eq_zero         ~> floor_less_zero
   485   floor_less_eq_one          ~> floor_less_one
   486   less_floor_eq_number_of    ~> number_of_less_floor
   487   less_floor_eq_zero         ~> zero_less_floor
   488   less_floor_eq_one          ~> one_less_floor
   489   floor_le_eq_number_of      ~> floor_le_number_of
   490   floor_le_eq_zero           ~> floor_le_zero
   491   floor_le_eq_one            ~> floor_le_one
   492   floor_subtract_number_of   ~> floor_diff_number_of
   493   floor_subtract_one         ~> floor_diff_one
   494   ceiling_number_of_eq       ~> ceiling_number_of
   495   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   496   ceiling_le_zero_eq         ~> ceiling_le_zero
   497   ceiling_le_eq_one          ~> ceiling_le_one
   498   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   499   less_ceiling_eq_zero       ~> zero_less_ceiling
   500   less_ceiling_eq_one        ~> one_less_ceiling
   501   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   502   ceiling_less_eq_zero       ~> ceiling_less_zero
   503   ceiling_less_eq_one        ~> ceiling_less_one
   504   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   505   le_ceiling_eq_zero         ~> zero_le_ceiling
   506   le_ceiling_eq_one          ~> one_le_ceiling
   507   ceiling_subtract_number_of ~> ceiling_diff_number_of
   508   ceiling_subtract_one       ~> ceiling_diff_one
   509 
   510 * Theory "Finite_Set": various folding_XXX locales facilitate the
   511 application of the various fold combinators on finite sets.
   512 
   513 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   514 provides abstract red-black tree type which is backed by "RBT_Impl" as
   515 implementation.  INCOMPATIBILTY.
   516 
   517 * Theory Library/Coinductive_List has been removed -- superseded by
   518 AFP/thys/Coinductive.
   519 
   520 * Theory PReal, including the type "preal" and related operations, has
   521 been removed.  INCOMPATIBILITY.
   522 
   523 * Real: new development using Cauchy Sequences.
   524 
   525 * Split off theory "Big_Operators" containing setsum, setprod,
   526 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   527 
   528 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   529 "Int" etc.  INCOMPATIBILITY.
   530 
   531 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   532 
   533 * New set of rules "ac_simps" provides combined assoc / commute
   534 rewrites for all interpretations of the appropriate generic locales.
   535 
   536 * Renamed theory "OrderedGroup" to "Groups" and split theory
   537 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   538 appropriate and more consistent names suitable for name prefixes
   539 within the HOL theories.  INCOMPATIBILITY.
   540 
   541 * Some generic constants have been put to appropriate theories:
   542   - less_eq, less: Orderings
   543   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   544   - inverse, divide: Rings
   545 INCOMPATIBILITY.
   546 
   547 * More consistent naming of type classes involving orderings (and
   548 lattices):
   549 
   550     lower_semilattice                   ~> semilattice_inf
   551     upper_semilattice                   ~> semilattice_sup
   552 
   553     dense_linear_order                  ~> dense_linorder
   554 
   555     pordered_ab_group_add               ~> ordered_ab_group_add
   556     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   557     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   558     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   559     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   560     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   561     pordered_cancel_semiring            ~> ordered_cancel_semiring
   562     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   563     pordered_comm_ring                  ~> ordered_comm_ring
   564     pordered_comm_semiring              ~> ordered_comm_semiring
   565     pordered_ring                       ~> ordered_ring
   566     pordered_ring_abs                   ~> ordered_ring_abs
   567     pordered_semiring                   ~> ordered_semiring
   568 
   569     ordered_ab_group_add                ~> linordered_ab_group_add
   570     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   571     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   572     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   573     ordered_field                       ~> linordered_field
   574     ordered_field_no_lb                 ~> linordered_field_no_lb
   575     ordered_field_no_ub                 ~> linordered_field_no_ub
   576     ordered_field_dense_linear_order    ~> dense_linordered_field
   577     ordered_idom                        ~> linordered_idom
   578     ordered_ring                        ~> linordered_ring
   579     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   580     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   581     ordered_ring_strict                 ~> linordered_ring_strict
   582     ordered_semidom                     ~> linordered_semidom
   583     ordered_semiring                    ~> linordered_semiring
   584     ordered_semiring_1                  ~> linordered_semiring_1
   585     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   586     ordered_semiring_strict             ~> linordered_semiring_strict
   587 
   588   The following slightly odd type classes have been moved to a
   589   separate theory Library/Lattice_Algebras:
   590 
   591     lordered_ab_group_add               ~> lattice_ab_group_add
   592     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   593     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   594     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   595     lordered_ring                       ~> lattice_ring
   596 
   597 INCOMPATIBILITY.
   598 
   599 * Refined field classes:
   600   - classes division_ring_inverse_zero, field_inverse_zero,
   601     linordered_field_inverse_zero include rule inverse 0 = 0 --
   602     subsumes former division_by_zero class;
   603   - numerous lemmas have been ported from field to division_ring.
   604 INCOMPATIBILITY.
   605 
   606 * Refined algebra theorem collections:
   607   - dropped theorem group group_simps, use algebra_simps instead;
   608   - dropped theorem group ring_simps, use field_simps instead;
   609   - proper theorem collection field_simps subsumes former theorem
   610     groups field_eq_simps and field_simps;
   611   - dropped lemma eq_minus_self_iff which is a duplicate for
   612     equal_neg_zero.
   613 INCOMPATIBILITY.
   614 
   615 * Theory Finite_Set and List: some lemmas have been generalized from
   616 sets to lattices:
   617 
   618   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   619   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   620   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   621   union_Union_fold_union        ~> sup_Sup_fold_sup
   622   Inter_fold_inter              ~> Inf_fold_inf
   623   Union_fold_union              ~> Sup_fold_sup
   624   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   625   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   626   INTER_fold_inter              ~> INFI_fold_inf
   627   UNION_fold_union              ~> SUPR_fold_sup
   628 
   629 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   630 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   631 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   632 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   633 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   634 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   635 
   636 * Reorganized theory Multiset: swapped notation of pointwise and
   637 multiset order:
   638 
   639   - pointwise ordering is instance of class order with standard syntax
   640     <= and <;
   641   - multiset ordering has syntax <=# and <#; partial order properties
   642     are provided by means of interpretation with prefix
   643     multiset_order;
   644   - less duplication, less historical organization of sections,
   645     conversion from associations lists to multisets, rudimentary code
   646     generation;
   647   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   648     if needed.
   649 
   650 Renamed:
   651 
   652   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   653   multi_count_ext  ~>  multiset_ext
   654   diff_union_inverse2  ~>  diff_union_cancelR
   655 
   656 INCOMPATIBILITY.
   657 
   658 * Theory Permutation: replaced local "remove" by List.remove1.
   659 
   660 * Code generation: ML and OCaml code is decorated with signatures.
   661 
   662 * Theory List: added transpose.
   663 
   664 * Library/Nat_Bijection.thy is a collection of bijective functions
   665 between nat and other types, which supersedes the older libraries
   666 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   667 
   668   Constants:
   669   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   670   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   671   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   672   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   673   Countable.pair_encode           ~> prod_encode
   674   NatIso.prod2nat                 ~> prod_encode
   675   NatIso.nat2prod                 ~> prod_decode
   676   NatIso.sum2nat                  ~> sum_encode
   677   NatIso.nat2sum                  ~> sum_decode
   678   NatIso.list2nat                 ~> list_encode
   679   NatIso.nat2list                 ~> list_decode
   680   NatIso.set2nat                  ~> set_encode
   681   NatIso.nat2set                  ~> set_decode
   682 
   683   Lemmas:
   684   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   685   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   686   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   687   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   688   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   689   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   690   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   691   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   692   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   693   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   694   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   695   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   696   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   697 
   698 * Sledgehammer:
   699   - Renamed ATP commands:
   700     atp_info     ~> sledgehammer running_atps
   701     atp_kill     ~> sledgehammer kill_atps
   702     atp_messages ~> sledgehammer messages
   703     atp_minimize ~> sledgehammer minimize
   704     print_atps   ~> sledgehammer available_atps
   705     INCOMPATIBILITY.
   706   - Added user's manual ("isabelle doc sledgehammer").
   707   - Added option syntax and "sledgehammer_params" to customize
   708     Sledgehammer's behavior.  See the manual for details.
   709   - Modified the Isar proof reconstruction code so that it produces
   710     direct proofs rather than proofs by contradiction.  (This feature
   711     is still experimental.)
   712   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   713     full-typed mode.
   714   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   715 
   716 * Nitpick:
   717   - Added and implemented "binary_ints" and "bits" options.
   718   - Added "std" option and implemented support for nonstandard models.
   719   - Added and implemented "finitize" option to improve the precision
   720     of infinite datatypes based on a monotonicity analysis.
   721   - Added support for quotient types.
   722   - Added support for "specification" and "ax_specification"
   723     constructs.
   724   - Added support for local definitions (for "function" and
   725     "termination" proofs).
   726   - Added support for term postprocessors.
   727   - Optimized "Multiset.multiset" and "FinFun.finfun".
   728   - Improved efficiency of "destroy_constrs" optimization.
   729   - Fixed soundness bugs related to "destroy_constrs" optimization and
   730     record getters.
   731   - Fixed soundness bug related to higher-order constructors.
   732   - Fixed soundness bug when "full_descrs" is enabled.
   733   - Improved precision of set constructs.
   734   - Added "atoms" option.
   735   - Added cache to speed up repeated Kodkod invocations on the same
   736     problems.
   737   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   738     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   739     "SAT4J_Light".  INCOMPATIBILITY.
   740   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   741     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   742   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   743 
   744 * Method "induct" now takes instantiations of the form t, where t is not
   745   a variable, as a shorthand for "x == t", where x is a fresh variable.
   746   If this is not intended, t has to be enclosed in parentheses.
   747   By default, the equalities generated by definitional instantiations
   748   are pre-simplified, which may cause parameters of inductive cases
   749   to disappear, or may even delete some of the inductive cases.
   750   Use "induct (no_simp)" instead of "induct" to restore the old
   751   behaviour. The (no_simp) option is also understood by the "cases"
   752   and "nominal_induct" methods, which now perform pre-simplification, too.
   753   INCOMPATIBILITY.
   754 
   755 
   756 *** HOLCF ***
   757 
   758 * Variable names in lemmas generated by the domain package have
   759 changed; the naming scheme is now consistent with the HOL datatype
   760 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   761 
   762 * The domain package no longer defines the function "foo_copy" for
   763 recursive domain "foo".  The reach lemma is now stated directly in
   764 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   765 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   766 
   767 * Most definedness lemmas generated by the domain package (previously
   768 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   769 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   770 Proofs that used definedness lemmas as intro rules may break,
   771 potential INCOMPATIBILITY.
   772 
   773 * Induction and casedist rules generated by the domain package now
   774 declare proper case_names (one called "bottom", and one named for each
   775 constructor).  INCOMPATIBILITY.
   776 
   777 * For mutually-recursive domains, separate "reach" and "take_lemma"
   778 rules are generated for each domain, INCOMPATIBILITY.
   779 
   780   foo_bar.reach       ~> foo.reach  bar.reach
   781   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   782 
   783 * Some lemmas generated by the domain package have been renamed for
   784 consistency with the datatype package, INCOMPATIBILITY.
   785 
   786   foo.ind        ~> foo.induct
   787   foo.finite_ind ~> foo.finite_induct
   788   foo.coind      ~> foo.coinduct
   789   foo.casedist   ~> foo.exhaust
   790   foo.exhaust    ~> foo.nchotomy
   791 
   792 * For consistency with other definition packages, the fixrec package
   793 now generates qualified theorem names, INCOMPATIBILITY.
   794 
   795   foo_simps  ~> foo.simps
   796   foo_unfold ~> foo.unfold
   797   foo_induct ~> foo.induct
   798 
   799 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   800 method and internal fixrec proofs now use the default simpset instead.
   801 INCOMPATIBILITY.
   802 
   803 * The "contlub" predicate has been removed.  Proof scripts should use
   804 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   805 
   806 * The "admw" predicate has been removed, INCOMPATIBILITY.
   807 
   808 * The constants cpair, cfst, and csnd have been removed in favor of
   809 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   810 
   811 
   812 *** ML ***
   813 
   814 * Antiquotations for basic formal entities:
   815 
   816     @{class NAME}         -- type class
   817     @{class_syntax NAME}  -- syntax representation of the above
   818 
   819     @{type_name NAME}     -- logical type
   820     @{type_abbrev NAME}   -- type abbreviation
   821     @{nonterminal NAME}   -- type of concrete syntactic category
   822     @{type_syntax NAME}   -- syntax representation of any of the above
   823 
   824     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   825     @{const_abbrev NAME}  -- abbreviated constant
   826     @{const_syntax NAME}  -- syntax representation of any of the above
   827 
   828 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   829 syntax constant (cf. 'syntax' command).
   830 
   831 * Antiquotation @{make_string} inlines a function to print arbitrary
   832 values similar to the ML toplevel.  The result is compiler dependent
   833 and may fall back on "?" in certain situations.
   834 
   835 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   836 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   837 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   838 not work with the asynchronous Isar document model.
   839 
   840 * Configuration options now admit dynamic default values, depending on
   841 the context or even global references.
   842 
   843 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   844 uses an efficient external library if available (for Poly/ML).
   845 
   846 * Renamed some important ML structures, while keeping the old names
   847 for some time as aliases within the structure Legacy:
   848 
   849   OuterKeyword  ~>  Keyword
   850   OuterLex      ~>  Token
   851   OuterParse    ~>  Parse
   852   OuterSyntax   ~>  Outer_Syntax
   853   PrintMode     ~>  Print_Mode
   854   SpecParse     ~>  Parse_Spec
   855   ThyInfo       ~>  Thy_Info
   856   ThyLoad       ~>  Thy_Load
   857   ThyOutput     ~>  Thy_Output
   858   TypeInfer     ~>  Type_Infer
   859 
   860 Note that "open Legacy" simplifies porting of sources, but forgetting
   861 to remove it again will complicate porting again in the future.
   862 
   863 * Most operations that refer to a global context are named
   864 accordingly, e.g. Simplifier.global_context or
   865 ProofContext.init_global.  There are some situations where a global
   866 context actually works, but under normal circumstances one needs to
   867 pass the proper local context through the code!
   868 
   869 * Discontinued old TheoryDataFun with its copy/init operation -- data
   870 needs to be pure.  Functor Theory_Data_PP retains the traditional
   871 Pretty.pp argument to merge, which is absent in the standard
   872 Theory_Data version.
   873 
   874 * Sorts.certify_sort and derived "cert" operations for types and terms
   875 no longer minimize sorts.  Thus certification at the boundary of the
   876 inference kernel becomes invariant under addition of class relations,
   877 which is an important monotonicity principle.  Sorts are now minimized
   878 in the syntax layer only, at the boundary between the end-user and the
   879 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   880 explicitly in rare situations.
   881 
   882 * Renamed old-style Drule.standard to Drule.export_without_context, to
   883 emphasize that this is in no way a standard operation.
   884 INCOMPATIBILITY.
   885 
   886 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   887 usual for resolution.  Rare INCOMPATIBILITY.
   888 
   889 * Renamed varify/unvarify operations to varify_global/unvarify_global
   890 to emphasize that these only work in a global situation (which is
   891 quite rare).
   892 
   893 * Curried take and drop in library.ML; negative length is interpreted
   894 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   895 
   896 * Proof terms: type substitutions on proof constants now use canonical
   897 order of type variables.  INCOMPATIBILITY for tools working with proof
   898 terms.
   899 
   900 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   901 may no longer carry premises.  User-level specifications are
   902 transformed accordingly by Thm.add_axiom/add_def.
   903 
   904 
   905 *** System ***
   906 
   907 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   908 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   909 proof terms are enabled unconditionally in the new HOL-Proofs image.
   910 
   911 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   912 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   913 respectively.
   914 
   915 * Old lib/scripts/polyml-platform is superseded by the
   916 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   917 variant, even on a 64 bit machine.  The following example setting
   918 prefers 64 bit if available:
   919 
   920   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   921 
   922 * The preliminary Isabelle/jEdit application demonstrates the emerging
   923 Isabelle/Scala layer for advanced prover interaction and integration.
   924 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   925 component.
   926 
   927 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   928 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   929 similar to the default assignment of the document preparation system
   930 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   931 provides some operations for direct access to the font without asking
   932 the user for manual installation.
   933 
   934 
   935 
   936 New in Isabelle2009-1 (December 2009)
   937 -------------------------------------
   938 
   939 *** General ***
   940 
   941 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   942 one backslash should be used, even in ML sources.
   943 
   944 
   945 *** Pure ***
   946 
   947 * Locale interpretation propagates mixins along the locale hierarchy.
   948 The currently only available mixins are the equations used to map
   949 local definitions to terms of the target domain of an interpretation.
   950 
   951 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   952 loc" to print all interpretations of locale "loc" in the theory.
   953 Interpretations in proofs are not shown.
   954 
   955 * Thoroughly revised locales tutorial.  New section on conditional
   956 interpretation.
   957 
   958 * On instantiation of classes, remaining undefined class parameters
   959 are formally declared.  INCOMPATIBILITY.
   960 
   961 
   962 *** Document preparation ***
   963 
   964 * New generalized style concept for printing terms: @{foo (style) ...}
   965 instead of @{foo_style style ...}  (old form is still retained for
   966 backward compatibility).  Styles can be also applied for
   967 antiquotations prop, term_type and typeof.
   968 
   969 
   970 *** HOL ***
   971 
   972 * New proof method "smt" for a combination of first-order logic with
   973 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   974 fixed-size bitvectors; there is also basic support for higher-order
   975 features (esp. lambda abstractions).  It is an incomplete decision
   976 procedure based on external SMT solvers using the oracle mechanism;
   977 for the SMT solver Z3, this method is proof-producing.  Certificates
   978 are provided to avoid calling the external solvers solely for
   979 re-checking proofs.  Due to a remote SMT service there is no need for
   980 installing SMT solvers locally.  See src/HOL/SMT.
   981 
   982 * New commands to load and prove verification conditions generated by
   983 the Boogie program verifier or derived systems (e.g. the Verifying C
   984 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   985 
   986 * New counterexample generator tool 'nitpick' based on the Kodkod
   987 relational model finder.  See src/HOL/Tools/Nitpick and
   988 src/HOL/Nitpick_Examples.
   989 
   990 * New commands 'code_pred' and 'values' to invoke the predicate
   991 compiler and to enumerate values of inductive predicates.
   992 
   993 * A tabled implementation of the reflexive transitive closure.
   994 
   995 * New implementation of quickcheck uses generic code generator;
   996 default generators are provided for all suitable HOL types, records
   997 and datatypes.  Old quickcheck can be re-activated importing theory
   998 Library/SML_Quickcheck.
   999 
  1000 * New testing tool Mirabelle for automated proof tools.  Applies
  1001 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1002 every proof step in a theory.  To be used in batch mode via the
  1003 "mirabelle" utility.
  1004 
  1005 * New proof method "sos" (sum of squares) for nonlinear real
  1006 arithmetic (originally due to John Harison). It requires theory
  1007 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1008 works well in practice on quantifier-free real arithmetic with +, -,
  1009 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1010 inequalities between polynomials.  It makes use of external
  1011 semidefinite programming solvers.  Method "sos" generates a
  1012 certificate that can be pasted into the proof thus avoiding the need
  1013 to call an external tool every time the proof is checked.  See
  1014 src/HOL/Library/Sum_Of_Squares.
  1015 
  1016 * New method "linarith" invokes existing linear arithmetic decision
  1017 procedure only.
  1018 
  1019 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1020 
  1021 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1022 Causes full type information to be output to the ATPs.  This slows
  1023 ATPs down considerably but eliminates a source of unsound "proofs"
  1024 that fail later.
  1025 
  1026 * New method "metisFT": A version of metis that uses full type
  1027 information in order to avoid failures of proof reconstruction.
  1028 
  1029 * New evaluator "approximate" approximates an real valued term using
  1030 the same method as the approximation method.
  1031 
  1032 * Method "approximate" now supports arithmetic expressions as
  1033 boundaries of intervals and implements interval splitting and Taylor
  1034 series expansion.
  1035 
  1036 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1037 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1038 
  1039 * New theory SupInf of the supremum and infimum operators for sets of
  1040 reals.
  1041 
  1042 * New theory Probability, which contains a development of measure
  1043 theory, eventually leading to Lebesgue integration and probability.
  1044 
  1045 * Extended Multivariate Analysis to include derivation and Brouwer's
  1046 fixpoint theorem.
  1047 
  1048 * Reorganization of number theory, INCOMPATIBILITY:
  1049   - new number theory development for nat and int, in theories Divides
  1050     and GCD as well as in new session Number_Theory
  1051   - some constants and facts now suffixed with _nat and _int
  1052     accordingly
  1053   - former session NumberTheory now named Old_Number_Theory, including
  1054     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1055   - moved theory Pocklington from src/HOL/Library to
  1056     src/HOL/Old_Number_Theory
  1057 
  1058 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1059 lcm of finite and infinite sets. It is shown that they form a complete
  1060 lattice.
  1061 
  1062 * Class semiring_div requires superclass no_zero_divisors and proof of
  1063 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1064 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1065 generalized to class semiring_div, subsuming former theorems
  1066 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1067 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1068 INCOMPATIBILITY.
  1069 
  1070 * Refinements to lattice classes and sets:
  1071   - less default intro/elim rules in locale variant, more default
  1072     intro/elim rules in class variant: more uniformity
  1073   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1074     le_inf_iff
  1075   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1076     sup_aci)
  1077   - renamed ACI to inf_sup_aci
  1078   - new class "boolean_algebra"
  1079   - class "complete_lattice" moved to separate theory
  1080     "Complete_Lattice"; corresponding constants (and abbreviations)
  1081     renamed and with authentic syntax:
  1082     Set.Inf ~>    Complete_Lattice.Inf
  1083     Set.Sup ~>    Complete_Lattice.Sup
  1084     Set.INFI ~>   Complete_Lattice.INFI
  1085     Set.SUPR ~>   Complete_Lattice.SUPR
  1086     Set.Inter ~>  Complete_Lattice.Inter
  1087     Set.Union ~>  Complete_Lattice.Union
  1088     Set.INTER ~>  Complete_Lattice.INTER
  1089     Set.UNION ~>  Complete_Lattice.UNION
  1090   - authentic syntax for
  1091     Set.Pow
  1092     Set.image
  1093   - mere abbreviations:
  1094     Set.empty               (for bot)
  1095     Set.UNIV                (for top)
  1096     Set.inter               (for inf, formerly Set.Int)
  1097     Set.union               (for sup, formerly Set.Un)
  1098     Complete_Lattice.Inter  (for Inf)
  1099     Complete_Lattice.Union  (for Sup)
  1100     Complete_Lattice.INTER  (for INFI)
  1101     Complete_Lattice.UNION  (for SUPR)
  1102   - object-logic definitions as far as appropriate
  1103 
  1104 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1105 Un_subset_iff are explicitly deleted as default simp rules; then also
  1106 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1107 deleted to achieve the desired effect.
  1108 
  1109 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1110 rules by default any longer; the same applies to min_max.inf_absorb1
  1111 etc.  INCOMPATIBILITY.
  1112 
  1113 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1114 pred_set_conv by default.  INCOMPATIBILITY.
  1115 
  1116 * Power operations on relations and functions are now one dedicated
  1117 constant "compow" with infix syntax "^^".  Power operation on
  1118 multiplicative monoids retains syntax "^" and is now defined generic
  1119 in class power.  INCOMPATIBILITY.
  1120 
  1121 * Relation composition "R O S" now has a more standard argument order:
  1122 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1123 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1124 break, since the O_assoc rule was not rewritten like this.  Fix using
  1125 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1126 
  1127 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1128 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1129 INCOMPATIBILITY.
  1130 
  1131 * Most rules produced by inductive and datatype package have mandatory
  1132 prefixes.  INCOMPATIBILITY.
  1133 
  1134 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1135 the attribute of the same name.  Each of the theorems in the list
  1136 DERIV_intros assumes composition with an additional function and
  1137 matches a variable to the derivative, which has to be solved by the
  1138 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1139 of most elementary terms.  Former Maclauren.DERIV_tac and
  1140 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1141 INCOMPATIBILITY.
  1142 
  1143 * Code generator attributes follow the usual underscore convention:
  1144     code_unfold     replaces    code unfold
  1145     code_post       replaces    code post
  1146     etc.
  1147   INCOMPATIBILITY.
  1148 
  1149 * Renamed methods:
  1150     sizechange -> size_change
  1151     induct_scheme -> induction_schema
  1152   INCOMPATIBILITY.
  1153 
  1154 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1155 INCOMPATIBILITY, use "undefined" directly.
  1156 
  1157 * Renamed theorems:
  1158     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1159     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1160     Suc_plus1 -> Suc_eq_plus1
  1161     *anti_sym -> *antisym*
  1162     vector_less_eq_def -> vector_le_def
  1163   INCOMPATIBILITY.
  1164 
  1165 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1166 INCOMPATIBILITY.
  1167 
  1168 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1169 INCOMPATIBILITY.
  1170 
  1171 
  1172 *** HOLCF ***
  1173 
  1174 * Theory Representable defines a class "rep" of domains that are
  1175 representable (via an ep-pair) in the universal domain type "udom".
  1176 Instances are provided for all type constructors defined in HOLCF.
  1177 
  1178 * The 'new_domain' command is a purely definitional version of the
  1179 domain package, for representable domains.  Syntax is identical to the
  1180 old domain package.  The 'new_domain' package also supports indirect
  1181 recursion using previously-defined type constructors.  See
  1182 src/HOLCF/ex/New_Domain.thy for examples.
  1183 
  1184 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1185 on the left-hand side of an equation, and then performs
  1186 simplification.  Rewriting is done using rules declared with the
  1187 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1188 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1189 
  1190 * The pattern-match compiler in 'fixrec' can now handle constructors
  1191 with HOL function types.  Pattern-match combinators for the Pair
  1192 constructor are pre-configured.
  1193 
  1194 * The 'fixrec' package now produces better fixed-point induction rules
  1195 for mutually-recursive definitions:  Induction rules have conclusions
  1196 of the form "P foo bar" instead of "P <foo, bar>".
  1197 
  1198 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1199 been renamed to "below".  The name "below" now replaces "less" in many
  1200 theorem names.  (Legacy theorem names using "less" are still supported
  1201 as well.)
  1202 
  1203 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1204 patterns can be used to generate strictness rules, or to make
  1205 functions more strict (much like the bang-patterns supported by the
  1206 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1207 examples.
  1208 
  1209 
  1210 *** ML ***
  1211 
  1212 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1213 errors and run-time exceptions, including detailed source positions.
  1214 
  1215 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1216 identified entries, with some additional information such as source
  1217 position, logical grouping etc.
  1218 
  1219 * Theory and context data is now introduced by the simplified and
  1220 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1221 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1222 copy operation) is still available for some time.
  1223 
  1224 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1225 provides a high-level programming interface to synchronized state
  1226 variables with atomic update.  This works via pure function
  1227 application within a critical section -- its runtime should be as
  1228 short as possible; beware of deadlocks if critical code is nested,
  1229 either directly or indirectly via other synchronized variables!
  1230 
  1231 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1232 wraps raw ML references, explicitly indicating their non-thread-safe
  1233 behaviour.  The Isar toplevel keeps this structure open, to
  1234 accommodate Proof General as well as quick and dirty interactive
  1235 experiments with references.
  1236 
  1237 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1238 parallel tactical reasoning.
  1239 
  1240 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1241 are similar to SUBPROOF, but are slightly more flexible: only the
  1242 specified parts of the subgoal are imported into the context, and the
  1243 body tactic may introduce new subgoals and schematic variables.
  1244 
  1245 * Old tactical METAHYPS, which does not observe the proof context, has
  1246 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1247 or Subgoal.FOCUS etc.
  1248 
  1249 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1250 functors have their own ML name space there is no point to mark them
  1251 separately.)  Minor INCOMPATIBILITY.
  1252 
  1253 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1254 
  1255 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1256 INCOMPATIBILITY.
  1257 
  1258 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1259 mode, which avoids critical setmp.
  1260 
  1261 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1262 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1263 Attrib/Method.setup introduced in Isabelle2009.
  1264 
  1265 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1266 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1267 last resort.  INCOMPATIBILITY.
  1268 
  1269 * Display.pretty_thm now requires a proper context (cf. former
  1270 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1271 or even Display.pretty_thm_without_context as last resort.
  1272 INCOMPATIBILITY.
  1273 
  1274 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1275 Syntax.pretty_typ/term directly, preferably with proper context
  1276 instead of global theory.
  1277 
  1278 
  1279 *** System ***
  1280 
  1281 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1282 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1283 usedir option -q.
  1284 
  1285 * Support for additional "Isabelle components" via etc/components, see
  1286 also the system manual.
  1287 
  1288 * The isabelle makeall tool now operates on all components with
  1289 IsaMakefile, not just hardwired "logics".
  1290 
  1291 * Removed "compress" option from isabelle-process and isabelle usedir;
  1292 this is always enabled.
  1293 
  1294 * Discontinued support for Poly/ML 4.x versions.
  1295 
  1296 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1297 on a given logic image.  This requires the lighttpd webserver and is
  1298 currently supported on Linux only.
  1299 
  1300 
  1301 
  1302 New in Isabelle2009 (April 2009)
  1303 --------------------------------
  1304 
  1305 *** General ***
  1306 
  1307 * Simplified main Isabelle executables, with less surprises on
  1308 case-insensitive file-systems (such as Mac OS).
  1309 
  1310   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1311     "isatool."
  1312 
  1313   - The former "isabelle" alias for "isabelle-process" has been
  1314     removed (should rarely occur to regular users).
  1315 
  1316   - The former "isabelle-interface" and its alias "Isabelle" have been
  1317     removed (interfaces are now regular Isabelle tools).
  1318 
  1319 Within scripts and make files, the Isabelle environment variables
  1320 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1321 respectively.  (The latter are still available as legacy feature.)
  1322 
  1323 The old isabelle-interface wrapper could react in confusing ways if
  1324 the interface was uninstalled or changed otherwise.  Individual
  1325 interface tool configuration is now more explicit, see also the
  1326 Isabelle system manual.  In particular, Proof General is now available
  1327 via "isabelle emacs".
  1328 
  1329 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1330 purge installed copies of Isabelle executables and re-run "isabelle
  1331 install -p ...", or use symlinks.
  1332 
  1333 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1334 old ~/isabelle, which was slightly non-standard and apt to cause
  1335 surprises on case-insensitive file-systems (such as Mac OS).
  1336 
  1337 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1338 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1339 care is required when using older releases of Isabelle.  Note that
  1340 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1341 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1342 
  1343 * Proofs of fully specified statements are run in parallel on
  1344 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1345 a regular 4-core machine, if the initial heap space is made reasonably
  1346 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1347 
  1348 * The main reference manuals ("isar-ref", "implementation", and
  1349 "system") have been updated and extended.  Formally checked references
  1350 as hyperlinks are now available uniformly.
  1351 
  1352 
  1353 *** Pure ***
  1354 
  1355 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1356 respects.  The most important changes are listed below.  See the
  1357 Tutorial on Locales ("locales" manual) for details.
  1358 
  1359 - In locale expressions, instantiation replaces renaming.  Parameters
  1360 must be declared in a for clause.  To aid compatibility with previous
  1361 parameter inheritance, in locale declarations, parameters that are not
  1362 'touched' (instantiation position "_" or omitted) are implicitly added
  1363 with their syntax at the beginning of the for clause.
  1364 
  1365 - Syntax from abbreviations and definitions in locales is available in
  1366 locale expressions and context elements.  The latter is particularly
  1367 useful in locale declarations.
  1368 
  1369 - More flexible mechanisms to qualify names generated by locale
  1370 expressions.  Qualifiers (prefixes) may be specified in locale
  1371 expressions, and can be marked as mandatory (syntax: "name!:") or
  1372 optional (syntax "name?:").  The default depends for plain "name:"
  1373 depends on the situation where a locale expression is used: in
  1374 commands 'locale' and 'sublocale' prefixes are optional, in
  1375 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1376 implicit qualifiers derived from the parameter names of a locale are
  1377 no longer generated.
  1378 
  1379 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1380 instantiation clause in "interpretation" and "interpret" (square
  1381 brackets) is no longer available.  Use locale expressions.
  1382 
  1383 - When converting proof scripts, mandatory qualifiers in
  1384 'interpretation' and 'interpret' should be retained by default, even
  1385 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1386 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1387 in locale expressions range over a single locale instance only.
  1388 
  1389 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1390 In existing theorem specifications replace the includes element by the
  1391 respective context elements of the included locale, omitting those
  1392 that are already present in the theorem specification.  Multiple
  1393 assume elements of a locale should be replaced by a single one
  1394 involving the locale predicate.  In the proof body, declarations (most
  1395 notably theorems) may be regained by interpreting the respective
  1396 locales in the proof context as required (command "interpret").
  1397 
  1398 If using "includes" in replacement of a target solely because the
  1399 parameter types in the theorem are not as general as in the target,
  1400 consider declaring a new locale with additional type constraints on
  1401 the parameters (context element "constrains").
  1402 
  1403 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1404 
  1405 - Locale interpretation commands no longer attempt to simplify goal.
  1406 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1407 methods intro_locales and unfold_locales to clarify.
  1408 
  1409 - Locale interpretation commands no longer accept interpretation
  1410 attributes.  INCOMPATIBILITY.
  1411 
  1412 * Class declaration: so-called "base sort" must not be given in import
  1413 list any longer, but is inferred from the specification.  Particularly
  1414 in HOL, write
  1415 
  1416     class foo = ...
  1417 
  1418 instead of
  1419 
  1420     class foo = type + ...
  1421 
  1422 * Class target: global versions of theorems stemming do not carry a
  1423 parameter prefix any longer.  INCOMPATIBILITY.
  1424 
  1425 * Class 'instance' command no longer accepts attached definitions.
  1426 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1427 
  1428 * Recovered hiding of consts, which was accidentally broken in
  1429 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1430 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1431 
  1432 * Slightly more coherent Pure syntax, with updated documentation in
  1433 isar-ref manual.  Removed locales meta_term_syntax and
  1434 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1435 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1436 directly in regular applications.
  1437 
  1438 * There is a new syntactic category "float_const" for signed decimal
  1439 fractions (e.g. 123.45 or -123.45).
  1440 
  1441 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1442 interface with 'setup' command instead.
  1443 
  1444 * Command 'local_setup' is similar to 'setup', but operates on a local
  1445 theory context.
  1446 
  1447 * The 'axiomatization' command now only works within a global theory
  1448 context.  INCOMPATIBILITY.
  1449 
  1450 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1451 hypotheses.  Sorts required in the course of reasoning need to be
  1452 covered by the constraints in the initial statement, completed by the
  1453 type instance information of the background theory.  Non-trivial sort
  1454 hypotheses, which rarely occur in practice, may be specified via
  1455 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1456 
  1457   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1458 
  1459 The result contains an implicit sort hypotheses as before --
  1460 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1461 normalization.
  1462 
  1463 * Generalized Isar history, with support for linear undo, direct state
  1464 addressing etc.
  1465 
  1466 * Changed defaults for unify configuration options:
  1467 
  1468   unify_trace_bound = 50 (formerly 25)
  1469   unify_search_bound = 60 (formerly 30)
  1470 
  1471 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1472 
  1473   a) On theory merge, the last set of code equations for a particular
  1474      constant is taken (in accordance with the policy applied by other
  1475      parts of the code generator framework).
  1476 
  1477   b) Code equations stemming from explicit declarations (e.g. code
  1478      attribute) gain priority over default code equations stemming
  1479      from definition, primrec, fun etc.
  1480 
  1481 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1482 
  1483 * Unified theorem tables for both code generators.  Thus [code
  1484 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1485 
  1486 * Command 'find_consts' searches for constants based on type and name
  1487 patterns, e.g.
  1488 
  1489     find_consts "_ => bool"
  1490 
  1491 By default, matching is against subtypes, but it may be restricted to
  1492 the whole type.  Searching by name is possible.  Multiple queries are
  1493 conjunctive and queries may be negated by prefixing them with a
  1494 hyphen:
  1495 
  1496     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1497 
  1498 * New 'find_theorems' criterion "solves" matches theorems that
  1499 directly solve the current goal (modulo higher-order unification).
  1500 
  1501 * Auto solve feature for main theorem statements: whenever a new goal
  1502 is stated, "find_theorems solves" is called; any theorems that could
  1503 solve the lemma directly are listed as part of the goal state.
  1504 Cf. associated options in Proof General Isabelle settings menu,
  1505 enabled by default, with reasonable timeout for pathological cases of
  1506 higher-order unification.
  1507 
  1508 
  1509 *** Document preparation ***
  1510 
  1511 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1512 demanding keyword 'by' and supporting the full method expression
  1513 syntax just like the Isar command 'by'.
  1514 
  1515 
  1516 *** HOL ***
  1517 
  1518 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1519 points Main and Complex_Main remain as before.
  1520 
  1521 * Logic image HOL-Plain provides a minimal HOL with the most important
  1522 tools available (inductive, datatype, primrec, ...).  This facilitates
  1523 experimentation and tool development.  Note that user applications
  1524 (and library theories) should never refer to anything below theory
  1525 Main, as before.
  1526 
  1527 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1528 experimentation due to shorter build times.
  1529 
  1530 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1531 were previously part of former HOL-Complex.  Entry point Hyperreal
  1532 remains valid, but theories formerly using Complex_Main should now use
  1533 new entry point Hypercomplex.
  1534 
  1535 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1536 Posix processes.  Avoids potentially expensive forking of the ML
  1537 process.  New thread-based implementation also works on non-Unix
  1538 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1539 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1540 commands are covered in the isar-ref manual.
  1541 
  1542 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1543 sledgehammer without local ATP installation (Vampire etc.). Other
  1544 provers may be included via suitable ML wrappers, see also
  1545 src/HOL/ATP_Linkup.thy.
  1546 
  1547 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1548 menu.
  1549 
  1550 * The metis method no longer fails because the theorem is too trivial
  1551 (contains the empty clause).
  1552 
  1553 * The metis method now fails in the usual manner, rather than raising
  1554 an exception, if it determines that it cannot prove the theorem.
  1555 
  1556 * Method "coherent" implements a prover for coherent logic (see also
  1557 src/Tools/coherent.ML).
  1558 
  1559 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1560 "undefined" is the right choice to replace "arbitrary", though
  1561 logically there is no difference.  INCOMPATIBILITY.
  1562 
  1563 * Command "value" now integrates different evaluation mechanisms.  The
  1564 result of the first successful evaluation mechanism is printed.  In
  1565 square brackets a particular named evaluation mechanisms may be
  1566 specified (currently, [SML], [code] or [nbe]).  See further
  1567 src/HOL/ex/Eval_Examples.thy.
  1568 
  1569 * Normalization by evaluation now allows non-leftlinear equations.
  1570 Declare with attribute [code nbe].
  1571 
  1572 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1573 as the structured Isar versions "cases" and "induct", cf. the
  1574 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1575 are now presented as a list of individual projections
  1576 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1577 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1578 rare situations a different rule is selected --- notably nested tuple
  1579 elimination instead of former prod.exhaust: use explicit (case_tac t
  1580 rule: prod.exhaust) here.
  1581 
  1582 * Attributes "cases", "induct", "coinduct" support "del" option.
  1583 
  1584 * Removed fact "case_split_thm", which duplicates "case_split".
  1585 
  1586 * The option datatype has been moved to a new theory Option.  Renamed
  1587 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1588 
  1589 * New predicate "strict_mono" classifies strict functions on partial
  1590 orders.  With strict functions on linear orders, reasoning about
  1591 (in)equalities is facilitated by theorems "strict_mono_eq",
  1592 "strict_mono_less_eq" and "strict_mono_less".
  1593 
  1594 * Some set operations are now proper qualified constants with
  1595 authentic syntax.  INCOMPATIBILITY:
  1596 
  1597     op Int ~>   Set.Int
  1598     op Un ~>    Set.Un
  1599     INTER ~>    Set.INTER
  1600     UNION ~>    Set.UNION
  1601     Inter ~>    Set.Inter
  1602     Union ~>    Set.Union
  1603     {} ~>       Set.empty
  1604     UNIV ~>     Set.UNIV
  1605 
  1606 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1607 theory Set.
  1608 
  1609 * Auxiliary class "itself" has disappeared -- classes without any
  1610 parameter are treated as expected by the 'class' command.
  1611 
  1612 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1613 
  1614 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1615 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1616 
  1617 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1618 method "approximation".  It proves formulas on real values by using
  1619 interval arithmetic.  In the formulas are also the transcendental
  1620 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1621 allowed. For examples see
  1622 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1623 
  1624 * Theory "Reflection" now resides in HOL/Library.
  1625 
  1626 * Entry point to Word library now simply named "Word".
  1627 INCOMPATIBILITY.
  1628 
  1629 * Made source layout more coherent with logical distribution
  1630 structure:
  1631 
  1632     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1633     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1634     src/HOL/Library/GCD.thy ~> src/HOL/
  1635     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1636     src/HOL/Library/Parity.thy ~> src/HOL/
  1637     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1638     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1639     src/HOL/Real/Lubs.thy ~> src/HOL/
  1640     src/HOL/Real/PReal.thy ~> src/HOL/
  1641     src/HOL/Real/Rational.thy ~> src/HOL/
  1642     src/HOL/Real/RComplete.thy ~> src/HOL/
  1643     src/HOL/Real/RealDef.thy ~> src/HOL/
  1644     src/HOL/Real/RealPow.thy ~> src/HOL/
  1645     src/HOL/Real/Real.thy ~> src/HOL/
  1646     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1647     src/HOL/Complex/Complex.thy ~> src/HOL/
  1648     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1649     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1650     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1651     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1652     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1653     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1654     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1655     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1656     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1657     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1658     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1659     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1660     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1661     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1662     src/HOL/Real/Float ~> src/HOL/Library/
  1663     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1664     src/HOL/Real/RealVector.thy ~> src/HOL/
  1665 
  1666     src/HOL/arith_data.ML ~> src/HOL/Tools
  1667     src/HOL/hologic.ML ~> src/HOL/Tools
  1668     src/HOL/simpdata.ML ~> src/HOL/Tools
  1669     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1670     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1671     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1672     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1673     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1674     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1675     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1676 
  1677     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1678     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1679     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1680     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1681     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1682     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1683 
  1684 * If methods "eval" and "evaluation" encounter a structured proof
  1685 state with !!/==>, only the conclusion is evaluated to True (if
  1686 possible), avoiding strange error messages.
  1687 
  1688 * Method "sizechange" automates termination proofs using (a
  1689 modification of) the size-change principle.  Requires SAT solver.  See
  1690 src/HOL/ex/Termination.thy for examples.
  1691 
  1692 * Simplifier: simproc for let expressions now unfolds if bound
  1693 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1694 
  1695 * Method "arith": Linear arithmetic now ignores all inequalities when
  1696 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1697 
  1698 * New attribute "arith" for facts that should always be used
  1699 automatically by arithmetic. It is intended to be used locally in
  1700 proofs, e.g.
  1701 
  1702   assumes [arith]: "x > 0"
  1703 
  1704 Global usage is discouraged because of possible performance impact.
  1705 
  1706 * New classes "top" and "bot" with corresponding operations "top" and
  1707 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1708 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1709 
  1710 * Changed definition lemma "less_fun_def" in order to provide an
  1711 instance for preorders on functions; use lemma "less_le" instead.
  1712 INCOMPATIBILITY.
  1713 
  1714 * Theory Orderings: class "wellorder" moved here, with explicit
  1715 induction rule "less_induct" as assumption.  For instantiation of
  1716 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1717 INCOMPATIBILITY.
  1718 
  1719 * Theory Orderings: added class "preorder" as superclass of "order".
  1720 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1721 etc. slightly changed.  Some theorems named order_class.* now named
  1722 preorder_class.*.
  1723 
  1724 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1725 "diag" to "Id_on".
  1726 
  1727 * Theory Finite_Set: added a new fold combinator of type
  1728 
  1729   ('a => 'b => 'b) => 'b => 'a set => 'b
  1730 
  1731 Occasionally this is more convenient than the old fold combinator
  1732 which is now defined in terms of the new one and renamed to
  1733 fold_image.
  1734 
  1735 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1736 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1737 extended with further lemmas!).  At the moment both still exist but
  1738 the former will disappear at some point.
  1739 
  1740 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1741 class recpower.  Type-specific simp rules for various recpower types
  1742 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1743 
  1744 rat_power_0    -> power_0
  1745 rat_power_Suc  -> power_Suc
  1746 realpow_0      -> power_0
  1747 realpow_Suc    -> power_Suc
  1748 complexpow_0   -> power_0
  1749 complexpow_Suc -> power_Suc
  1750 power_poly_0   -> power_0
  1751 power_poly_Suc -> power_Suc
  1752 
  1753 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1754 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1755 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1756 of lemmas from Divides has been generalized from nat to class
  1757 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1758 renames resulting from duplicate elimination:
  1759 
  1760     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1761     zero_dvd_iff ~>         dvd_0_left_iff
  1762     dvd_0 ~>                dvd_0_right
  1763     DIVISION_BY_ZERO_DIV ~> div_by_0
  1764     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1765     mult_div ~>             div_mult_self2_is_id
  1766     mult_mod ~>             mod_mult_self2_is_0
  1767 
  1768 * Theory IntDiv: removed many lemmas that are instances of class-based
  1769 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1770 rename old lemmas as follows:
  1771 
  1772 dvd_diff               -> nat_dvd_diff
  1773 dvd_zminus_iff         -> dvd_minus_iff
  1774 mod_add1_eq            -> mod_add_eq
  1775 mod_mult1_eq           -> mod_mult_right_eq
  1776 mod_mult1_eq'          -> mod_mult_left_eq
  1777 mod_mult_distrib_mod   -> mod_mult_eq
  1778 nat_mod_add_left_eq    -> mod_add_left_eq
  1779 nat_mod_add_right_eq   -> mod_add_right_eq
  1780 nat_mod_div_trivial    -> mod_div_trivial
  1781 nat_mod_mod_trivial    -> mod_mod_trivial
  1782 zdiv_zadd_self1        -> div_add_self1
  1783 zdiv_zadd_self2        -> div_add_self2
  1784 zdiv_zmult_self1       -> div_mult_self2_is_id
  1785 zdiv_zmult_self2       -> div_mult_self1_is_id
  1786 zdvd_triv_left         -> dvd_triv_left
  1787 zdvd_triv_right        -> dvd_triv_right
  1788 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1789 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1790 zmod_zadd_left_eq      -> mod_add_left_eq
  1791 zmod_zadd_right_eq     -> mod_add_right_eq
  1792 zmod_zadd_self1        -> mod_add_self1
  1793 zmod_zadd_self2        -> mod_add_self2
  1794 zmod_zadd1_eq          -> mod_add_eq
  1795 zmod_zdiff1_eq         -> mod_diff_eq
  1796 zmod_zdvd_zmod         -> mod_mod_cancel
  1797 zmod_zmod_cancel       -> mod_mod_cancel
  1798 zmod_zmult_self1       -> mod_mult_self2_is_0
  1799 zmod_zmult_self2       -> mod_mult_self1_is_0
  1800 zmod_1                 -> mod_by_1
  1801 zdiv_1                 -> div_by_1
  1802 zdvd_abs1              -> abs_dvd_iff
  1803 zdvd_abs2              -> dvd_abs_iff
  1804 zdvd_refl              -> dvd_refl
  1805 zdvd_trans             -> dvd_trans
  1806 zdvd_zadd              -> dvd_add
  1807 zdvd_zdiff             -> dvd_diff
  1808 zdvd_zminus_iff        -> dvd_minus_iff
  1809 zdvd_zminus2_iff       -> minus_dvd_iff
  1810 zdvd_zmultD            -> dvd_mult_right
  1811 zdvd_zmultD2           -> dvd_mult_left
  1812 zdvd_zmult_mono        -> mult_dvd_mono
  1813 zdvd_0_right           -> dvd_0_right
  1814 zdvd_0_left            -> dvd_0_left_iff
  1815 zdvd_1_left            -> one_dvd
  1816 zminus_dvd_iff         -> minus_dvd_iff
  1817 
  1818 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1819 
  1820 * The real numbers offer decimal input syntax: 12.34 is translated
  1821 into 1234/10^2. This translation is not reversed upon output.
  1822 
  1823 * Theory Library/Polynomial defines an abstract type 'a poly of
  1824 univariate polynomials with coefficients of type 'a.  In addition to
  1825 the standard ring operations, it also supports div and mod.  Code
  1826 generation is also supported, using list-style constructors.
  1827 
  1828 * Theory Library/Inner_Product defines a class of real_inner for real
  1829 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1830 => real.  Class real_inner is a subclass of real_normed_vector from
  1831 theory RealVector.
  1832 
  1833 * Theory Library/Product_Vector provides instances for the product
  1834 type 'a * 'b of several classes from RealVector and Inner_Product.
  1835 Definitions of addition, subtraction, scalar multiplication, norms,
  1836 and inner products are included.
  1837 
  1838 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1839 addition to the field operations, numerals and case syntax are also
  1840 supported.
  1841 
  1842 * Theory Library/Diagonalize provides constructive version of Cantor's
  1843 first diagonalization argument.
  1844 
  1845 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1846 zlcm (for int); carried together from various gcd/lcm developements in
  1847 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1848 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1849 may recover tupled syntax as follows:
  1850 
  1851     hide (open) const gcd
  1852     abbreviation gcd where
  1853       "gcd == (%(a, b). GCD.gcd a b)"
  1854     notation (output)
  1855       GCD.gcd ("gcd '(_, _')")
  1856 
  1857 The same works for lcm, zgcd, zlcm.
  1858 
  1859 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1860 instantiations for algebraic structures.  Removed some duplicate
  1861 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1862 
  1863 * ML antiquotation @{code} takes a constant as argument and generates
  1864 corresponding code in background and inserts name of the corresponding
  1865 resulting ML value/function/datatype constructor binding in place.
  1866 All occurrences of @{code} with a single ML block are generated
  1867 simultaneously.  Provides a generic and safe interface for
  1868 instrumentalizing code generation.  See
  1869 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1870 In future you ought to refrain from ad-hoc compiling generated SML
  1871 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1872 cannot refer to constants for which user-defined serializations are
  1873 set.  Refer to the corresponding ML counterpart directly in that
  1874 cases.
  1875 
  1876 * Command 'rep_datatype': instead of theorem names the command now
  1877 takes a list of terms denoting the constructors of the type to be
  1878 represented as datatype.  The characteristic theorems have to be
  1879 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1880 have disappeared in favour of existing ones:
  1881 
  1882     unit_induct                 ~> unit.induct
  1883     prod_induct                 ~> prod.induct
  1884     sum_induct                  ~> sum.induct
  1885     Suc_Suc_eq                  ~> nat.inject
  1886     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1887 
  1888 
  1889 *** HOL-Algebra ***
  1890 
  1891 * New locales for orders and lattices where the equivalence relation
  1892 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1893 locales use a record structure with field eq for the equivalence.
  1894 
  1895 * New theory of factorial domains.
  1896 
  1897 * Units_l_inv and Units_r_inv are now simp rules by default.
  1898 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1899 and/or r_inv will now also require deletion of these lemmas.
  1900 
  1901 * Renamed the following theorems, INCOMPATIBILITY:
  1902 
  1903 UpperD ~> Upper_memD
  1904 LowerD ~> Lower_memD
  1905 least_carrier ~> least_closed
  1906 greatest_carrier ~> greatest_closed
  1907 greatest_Lower_above ~> greatest_Lower_below
  1908 one_zero ~> carrier_one_zero
  1909 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1910 
  1911 
  1912 *** HOL-Nominal ***
  1913 
  1914 * Nominal datatypes can now contain type-variables.
  1915 
  1916 * Commands 'nominal_inductive' and 'equivariance' work with local
  1917 theory targets.
  1918 
  1919 * Nominal primrec can now works with local theory targets and its
  1920 specification syntax now conforms to the general format as seen in
  1921 'inductive' etc.
  1922 
  1923 * Method "perm_simp" honours the standard simplifier attributes
  1924 (no_asm), (no_asm_use) etc.
  1925 
  1926 * The new predicate #* is defined like freshness, except that on the
  1927 left hand side can be a set or list of atoms.
  1928 
  1929 * Experimental command 'nominal_inductive2' derives strong induction
  1930 principles for inductive definitions.  In contrast to
  1931 'nominal_inductive', which can only deal with a fixed number of
  1932 binders, it can deal with arbitrary expressions standing for sets of
  1933 atoms to be avoided.  The only inductive definition we have at the
  1934 moment that needs this generalisation is the typing rule for Lets in
  1935 the algorithm W:
  1936 
  1937  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1938  -----------------------------------------------------------------
  1939          Gamma |- Let x be t1 in t2 : T2
  1940 
  1941 In this rule one wants to avoid all the binders that are introduced by
  1942 "close Gamma T1".  We are looking for other examples where this
  1943 feature might be useful.  Please let us know.
  1944 
  1945 
  1946 *** HOLCF ***
  1947 
  1948 * Reimplemented the simplification procedure for proving continuity
  1949 subgoals.  The new simproc is extensible; users can declare additional
  1950 continuity introduction rules with the attribute [cont2cont].
  1951 
  1952 * The continuity simproc now uses a different introduction rule for
  1953 solving continuity subgoals on terms with lambda abstractions.  In
  1954 some rare cases the new simproc may fail to solve subgoals that the
  1955 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1956 Potential INCOMPATIBILITY.
  1957 
  1958 * Command 'fixrec': specification syntax now conforms to the general
  1959 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1960 examples.  INCOMPATIBILITY.
  1961 
  1962 
  1963 *** ZF ***
  1964 
  1965 * Proof of Zorn's Lemma for partial orders.
  1966 
  1967 
  1968 *** ML ***
  1969 
  1970 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1971 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1972 depends on multithreading, so timouts will not work before Poly/ML
  1973 5.2.1!
  1974 
  1975 * High-level support for concurrent ML programming, see
  1976 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1977 particularly convenient to organize independent functional
  1978 computations.  The concept of "synchronized variables" provides a
  1979 higher-order interface for components with shared state, avoiding the
  1980 delicate details of mutexes and condition variables.  (Requires
  1981 Poly/ML 5.2.1 or later.)
  1982 
  1983 * ML bindings produced via Isar commands are stored within the Isar
  1984 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1985 become thread-safe and work with undo as expected (concerning
  1986 top-level bindings, not side-effects on global references).
  1987 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1988 compiler at runtime; really global bindings need to be given outside a
  1989 theory.  (Requires Poly/ML 5.2 or later.)
  1990 
  1991 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1992 context.  Top-level ML bindings are stored within the proof context in
  1993 a purely sequential fashion, disregarding the nested proof structure.
  1994 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1995 proof.  (Requires Poly/ML 5.2 or later.)
  1996 
  1997 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1998 and Method.setup, as well as Isar commands 'attribute_setup' and
  1999 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2000 existing code accordingly, or use plain 'setup' together with old
  2001 Method.add_method.
  2002 
  2003 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2004 to 'a -> thm, while results are always tagged with an authentic oracle
  2005 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2006 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2007 accordingly.  Note that extra performance may be gained by producing
  2008 the cterm carefully, avoiding slow Thm.cterm_of.
  2009 
  2010 * Simplified interface for defining document antiquotations via
  2011 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2012 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2013 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2014 examples.
  2015 
  2016 * More systematic treatment of long names, abstract name bindings, and
  2017 name space operations.  Basic operations on qualified names have been
  2018 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2019 Long_Name.append.  Old type bstring has been mostly replaced by
  2020 abstract type binding (see structure Binding), which supports precise
  2021 qualification by packages and local theory targets, as well as proper
  2022 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2023 bstring values into Binding.name, or better pass through abstract
  2024 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2025 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2026 
  2027 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2028 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2029 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2030 
  2031 * Disposed old type and term read functions (Sign.read_def_typ,
  2032 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2033 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2034 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2035 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2036 resort for legacy applications.
  2037 
  2038 * Disposed old declarations, tactics, tactic combinators that refer to
  2039 the simpset or claset of an implicit theory (such as Addsimps,
  2040 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2041 embedded ML text, or local_simpset_of with a proper context passed as
  2042 explicit runtime argument.
  2043 
  2044 * Rules and tactics that read instantiations (read_instantiate,
  2045 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2046 context, which is required for parsing and type-checking.  Moreover,
  2047 the variables are specified as plain indexnames, not string encodings
  2048 thereof.  INCOMPATIBILITY.
  2049 
  2050 * Generic Toplevel.add_hook interface allows to analyze the result of
  2051 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2052 for theorem dependency output of transactions resulting in a new
  2053 theory state.
  2054 
  2055 * ML antiquotations: block-structured compilation context indicated by
  2056 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2057 
  2058   @{binding name}                         - basic name binding
  2059   @{let ?pat = term}                      - term abbreviation (HO matching)
  2060   @{note name = fact}                     - fact abbreviation
  2061   @{thm fact}                             - singleton fact (with attributes)
  2062   @{thms fact}                            - general fact (with attributes)
  2063   @{lemma prop by method}                 - singleton goal
  2064   @{lemma prop by meth1 meth2}            - singleton goal
  2065   @{lemma prop1 ... propN by method}      - general goal
  2066   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2067   @{lemma (open) ...}                     - open derivation
  2068 
  2069 
  2070 *** System ***
  2071 
  2072 * The Isabelle "emacs" tool provides a specific interface to invoke
  2073 Proof General / Emacs, with more explicit failure if that is not
  2074 installed (the old isabelle-interface script silently falls back on
  2075 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2076 installation location of the Proof General distribution.
  2077 
  2078 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2079 the Isabelle process into a JVM/Scala application.  See
  2080 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2081 process wrapper has been discontinued.)
  2082 
  2083 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2084 
  2085 * Various status messages (with exact source position information) are
  2086 emitted, if proper markup print mode is enabled.  This allows
  2087 user-interface components to provide detailed feedback on internal
  2088 prover operations.
  2089 
  2090 
  2091 
  2092 New in Isabelle2008 (June 2008)
  2093 -------------------------------
  2094 
  2095 *** General ***
  2096 
  2097 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2098 and updated, with formally checked references as hyperlinks.
  2099 
  2100 * Theory loader: use_thy (and similar operations) no longer set the
  2101 implicit ML context, which was occasionally hard to predict and in
  2102 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2103 provides a proper context already.
  2104 
  2105 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2106 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2107 'use' within a theory file will do the job.
  2108 
  2109 * Name space merge now observes canonical order, i.e. the second space
  2110 is inserted into the first one, while existing entries in the first
  2111 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2112 swap theory imports.
  2113 
  2114 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2115 INCOMPATIBILITY in identifier syntax etc.
  2116 
  2117 * Outer syntax: string tokens no longer admit escaped white space,
  2118 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2119 white space without escapes.
  2120 
  2121 * Outer syntax: string tokens may contain arbitrary character codes
  2122 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2123 "foo_bar".
  2124 
  2125 
  2126 *** Pure ***
  2127 
  2128 * Context-dependent token translations.  Default setup reverts locally
  2129 fixed variables, and adds hilite markup for undeclared frees.
  2130 
  2131 * Unused theorems can be found using the new command 'unused_thms'.
  2132 There are three ways of invoking it:
  2133 
  2134 (1) unused_thms
  2135      Only finds unused theorems in the current theory.
  2136 
  2137 (2) unused_thms thy_1 ... thy_n -
  2138      Finds unused theorems in the current theory and all of its ancestors,
  2139      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2140 
  2141 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2142      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2143      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2144      their ancestors.
  2145 
  2146 In order to increase the readability of the list produced by
  2147 unused_thms, theorems that have been created by a particular instance
  2148 of a theory command such as 'inductive' or 'function' are considered
  2149 to belong to the same "group", meaning that if at least one theorem in
  2150 this group is used, the other theorems in the same group are no longer
  2151 reported as unused.  Moreover, if all theorems in the group are
  2152 unused, only one theorem in the group is displayed.
  2153 
  2154 Note that proof objects have to be switched on in order for
  2155 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2156 usually the case when using Proof General with the default settings).
  2157 
  2158 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2159 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2160 duplicate fact bindings, or even accidental fact duplications.  Note
  2161 that tools may maintain dynamically scoped facts systematically, using
  2162 PureThy.add_thms_dynamic.
  2163 
  2164 * Command 'hide' now allows to hide from "fact" name space as well.
  2165 
  2166 * Eliminated destructive theorem database, simpset, claset, and
  2167 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2168 update of theories within ML code.
  2169 
  2170 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2171 INCOMPATIBILITY, object-logics depending on former Pure require
  2172 additional setup PureThy.old_appl_syntax_setup; object-logics
  2173 depending on former CPure need to refer to Pure.
  2174 
  2175 * Commands 'use' and 'ML' are now purely functional, operating on
  2176 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2177 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2178 INCOMPATIBILITY.
  2179 
  2180 * Command 'setup': discontinued implicit version with ML reference.
  2181 
  2182 * Instantiation target allows for simultaneous specification of class
  2183 instance operations together with an instantiation proof.
  2184 Type-checking phase allows to refer to class operations uniformly.
  2185 See src/HOL/Complex/Complex.thy for an Isar example and
  2186 src/HOL/Library/Eval.thy for an ML example.
  2187 
  2188 * Indexing of literal facts: be more serious about including only
  2189 facts from the visible specification/proof context, but not the
  2190 background context (locale etc.).  Affects `prop` notation and method
  2191 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2192 situations.
  2193 
  2194 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2195 "(open)" option, which used to expose internal bound variables to the
  2196 proof text.
  2197 
  2198 * Isar statements: removed obsolete case "rule_context".
  2199 INCOMPATIBILITY, better use explicit fixes/assumes.
  2200 
  2201 * Locale proofs: default proof step now includes 'unfold_locales';
  2202 hence 'proof' without argument may be used to unfold locale
  2203 predicates.
  2204 
  2205 
  2206 *** Document preparation ***
  2207 
  2208 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2209 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2210 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2211 spot); renamed link color from "darkblue" to "linkcolor" (default
  2212 value unchanged, can be redefined via \definecolor); no longer sets
  2213 "a4paper" option (unnecessary or even intrusive).
  2214 
  2215 * Antiquotation @{lemma A method} proves proposition A by the given
  2216 method (either a method name or a method name plus (optional) method
  2217 arguments in parentheses) and prints A just like @{prop A}.
  2218 
  2219 
  2220 *** HOL ***
  2221 
  2222 * New primrec package.  Specification syntax conforms in style to
  2223 definition/function/....  No separate induction rule is provided.  The
  2224 "primrec" command distinguishes old-style and new-style specifications
  2225 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2226 When adjusting theories, beware: constants stemming from new-style
  2227 primrec specifications have authentic syntax.
  2228 
  2229 * Metis prover is now an order of magnitude faster, and also works
  2230 with multithreading.
  2231 
  2232 * Metis: the maximum number of clauses that can be produced from a
  2233 theorem is now given by the attribute max_clauses.  Theorems that
  2234 exceed this number are ignored, with a warning printed.
  2235 
  2236 * Sledgehammer no longer produces structured proofs by default. To
  2237 enable, declare [[sledgehammer_full = true]].  Attributes
  2238 reconstruction_modulus, reconstruction_sorts renamed
  2239 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2240 
  2241 * Method "induct_scheme" derives user-specified induction rules
  2242 from well-founded induction and completeness of patterns. This factors
  2243 out some operations that are done internally by the function package
  2244 and makes them available separately.  See
  2245 src/HOL/ex/Induction_Scheme.thy for examples.
  2246 
  2247 * More flexible generation of measure functions for termination
  2248 proofs: Measure functions can be declared by proving a rule of the
  2249 form "is_measure f" and giving it the [measure_function] attribute.
  2250 The "is_measure" predicate is logically meaningless (always true), and
  2251 just guides the heuristic.  To find suitable measure functions, the
  2252 termination prover sets up the goal "is_measure ?f" of the appropriate
  2253 type and generates all solutions by prolog-style backwards proof using
  2254 the declared rules.
  2255 
  2256 This setup also deals with rules like 
  2257 
  2258   "is_measure f ==> is_measure (list_size f)"
  2259 
  2260 which accommodates nested datatypes that recurse through lists.
  2261 Similar rules are predeclared for products and option types.
  2262 
  2263 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2264 
  2265   INCOMPATIBILITIES:
  2266 
  2267   - Definitions of overloaded constants on sets have to be replaced by
  2268     definitions on => and bool.
  2269 
  2270   - Some definitions of overloaded operators on sets can now be proved
  2271     using the definitions of the operators on => and bool.  Therefore,
  2272     the following theorems have been renamed:
  2273 
  2274       subset_def   -> subset_eq
  2275       psubset_def  -> psubset_eq
  2276       set_diff_def -> set_diff_eq
  2277       Compl_def    -> Compl_eq
  2278       Sup_set_def  -> Sup_set_eq
  2279       Inf_set_def  -> Inf_set_eq
  2280       sup_set_def  -> sup_set_eq
  2281       inf_set_def  -> inf_set_eq
  2282 
  2283   - Due to the incompleteness of the HO unification algorithm, some
  2284     rules such as subst may require manual instantiation, if some of
  2285     the unknowns in the rule is a set.
  2286 
  2287   - Higher order unification and forward proofs:
  2288     The proof pattern
  2289 
  2290       have "P (S::'a set)" <...>
  2291       then have "EX S. P S" ..
  2292 
  2293     no longer works (due to the incompleteness of the HO unification
  2294     algorithm) and must be replaced by the pattern
  2295 
  2296       have "EX S. P S"
  2297       proof
  2298         show "P S" <...>
  2299       qed
  2300 
  2301   - Calculational reasoning with subst (or similar rules):
  2302     The proof pattern
  2303 
  2304       have "P (S::'a set)" <...>
  2305       also have "S = T" <...>
  2306       finally have "P T" .
  2307 
  2308     no longer works (for similar reasons as the previous example) and
  2309     must be replaced by something like
  2310 
  2311       have "P (S::'a set)" <...>
  2312       moreover have "S = T" <...>
  2313       ultimately have "P T" by simp
  2314 
  2315   - Tactics or packages written in ML code:
  2316     Code performing pattern matching on types via
  2317 
  2318       Type ("set", [T]) => ...
  2319 
  2320     must be rewritten. Moreover, functions like strip_type or
  2321     binder_types no longer return the right value when applied to a
  2322     type of the form
  2323 
  2324       T1 => ... => Tn => U => bool
  2325 
  2326     rather than
  2327 
  2328       T1 => ... => Tn => U set
  2329 
  2330 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2331 Wellfounded_Relations to theory Wellfounded.
  2332 
  2333 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2334 
  2335 * Class finite no longer treats UNIV as class parameter.  Use class
  2336 enum from theory Library/Enum instead to achieve a similar effect.
  2337 INCOMPATIBILITY.
  2338 
  2339 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2340 and "Cons".  INCOMPATIBILITY.
  2341 
  2342 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2343 Potential INCOMPATIBILITY.
  2344 
  2345 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2346 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2347 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2348 
  2349 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2350 the same name in theory Orderings:
  2351 
  2352   less_trans
  2353   less_linear
  2354   le_imp_less_or_eq
  2355   le_less_trans
  2356   less_le_trans
  2357   less_not_sym
  2358   less_asym
  2359 
  2360 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2361 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2362 and different variable names.
  2363 
  2364 * Library/Option_ord.thy: Canonical order on option type.
  2365 
  2366 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2367 finite maps.
  2368 
  2369 * Library/Countable.thy: Type class for countable types.
  2370 
  2371 * Theory Int: The representation of numerals has changed.  The infix
  2372 operator BIT and the bit datatype with constructors B0 and B1 have
  2373 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2374 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2375 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2376 accordingly.
  2377 
  2378 * Theory Nat: definition of <= and < on natural numbers no longer
  2379 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2380 le_def and less_def have disappeared.  Consider lemmas not_less
  2381 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2382 
  2383 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2384 (whose purpose mainly is for various fold_set functionals) have been
  2385 abandoned in favor of the existing algebraic classes
  2386 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2387 lower_semilattice (resp. upper_semilattice) and linorder.
  2388 INCOMPATIBILITY.
  2389 
  2390 * Theory Transitive_Closure: induct and cases rules now declare proper
  2391 case_names ("base" and "step").  INCOMPATIBILITY.
  2392 
  2393 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2394 lattices.  The form set-specific version is available as
  2395 Inductive.lfp_ordinal_induct_set.
  2396 
  2397 * Renamed theorems "power.simps" to "power_int.simps".
  2398 INCOMPATIBILITY.
  2399 
  2400 * Class semiring_div provides basic abstract properties of semirings
  2401 with division and modulo operations.  Subsumes former class dvd_mod.
  2402 
  2403 * Merged theories IntDef, Numeral and IntArith into unified theory
  2404 Int.  INCOMPATIBILITY.
  2405 
  2406 * Theory Library/Code_Index: type "index" now represents natural
  2407 numbers rather than integers.  INCOMPATIBILITY.
  2408 
  2409 * New class "uminus" with operation "uminus" (split of from class
  2410 "minus" which now only has operation "minus", binary).
  2411 INCOMPATIBILITY.
  2412 
  2413 * Constants "card", "internal_split", "option_map" now with authentic
  2414 syntax.  INCOMPATIBILITY.
  2415 
  2416 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2417 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2418 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2419 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2420 Sup_set_def, le_def, less_def, option_map_def now with object
  2421 equality.  INCOMPATIBILITY.
  2422 
  2423 * Records. Removed K_record, and replaced it by pure lambda term
  2424 %x. c. The simplifier setup is now more robust against eta expansion.
  2425 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2426 
  2427 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2428 
  2429 * Library/ListVector: new theory of arithmetic vector operations.
  2430 
  2431 * Library/Order_Relation: new theory of various orderings as sets of
  2432 pairs.  Defines preorders, partial orders, linear orders and
  2433 well-orders on sets and on types.
  2434 
  2435 
  2436 *** ZF ***
  2437 
  2438 * Renamed some theories to allow to loading both ZF and HOL in the
  2439 same session:
  2440 
  2441   Datatype  -> Datatype_ZF
  2442   Inductive -> Inductive_ZF
  2443   Int       -> Int_ZF
  2444   IntDiv    -> IntDiv_ZF
  2445   Nat       -> Nat_ZF
  2446   List      -> List_ZF
  2447   Main      -> Main_ZF
  2448 
  2449 INCOMPATIBILITY: ZF theories that import individual theories below
  2450 Main might need to be adapted.  Regular theory Main is still
  2451 available, as trivial extension of Main_ZF.
  2452 
  2453 
  2454 *** ML ***
  2455 
  2456 * ML within Isar: antiquotation @{const name} or @{const
  2457 name(typargs)} produces statically-checked Const term.
  2458 
  2459 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2460 (of the same name).  Removed obsolete print command.
  2461 
  2462 * Removed obsolete "use_legacy_bindings" function.
  2463 
  2464 * The ``print mode'' is now a thread-local value derived from a global
  2465 template (the former print_mode reference), thus access becomes
  2466 non-critical.  The global print_mode reference is for session
  2467 management only; user-code should use print_mode_value,
  2468 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2469 
  2470 * Functions system/system_out provide a robust way to invoke external
  2471 shell commands, with propagation of interrupts (requires Poly/ML
  2472 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2473 
  2474 
  2475 *** System ***
  2476 
  2477 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2478 in accordance with Proof General 3.7, which prefers GNU emacs.
  2479 
  2480 * isatool tty runs Isabelle process with plain tty interaction;
  2481 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2482 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2483 
  2484 * isatool browser now works with Cygwin as well, using general
  2485 "javapath" function defined in Isabelle process environment.
  2486 
  2487 * YXML notation provides a simple and efficient alternative to
  2488 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2489 isatool yxml as described in the Isabelle system manual.
  2490 
  2491 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2492 provides general wrapper for managing an Isabelle process in a robust
  2493 fashion, with ``cooked'' output from stdin/stderr.
  2494 
  2495 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2496 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2497 
  2498 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2499 way of changing the user's settings is via
  2500 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2501 script.
  2502 
  2503 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2504 cores of the underlying machine, which is a good starting point for
  2505 optimal performance tuning.  The corresponding usedir option -M allows
  2506 "max" as an alias for "0".  WARNING: does not work on certain versions
  2507 of Mac OS (with Poly/ML 5.1).
  2508 
  2509 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2510 adverse effect of Isabelle flooding interactive front-ends (notably
  2511 ProofGeneral / XEmacs).
  2512 
  2513 
  2514 
  2515 New in Isabelle2007 (November 2007)
  2516 -----------------------------------
  2517 
  2518 *** General ***
  2519 
  2520 * More uniform information about legacy features, notably a
  2521 warning/error of "Legacy feature: ...", depending on the state of the
  2522 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2523 legacy features will disappear eventually.
  2524 
  2525 * Theory syntax: the header format ``theory A = B + C:'' has been
  2526 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2527 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2528 
  2529 * Theory syntax: the old non-Isar theory file format has been
  2530 discontinued altogether.  Note that ML proof scripts may still be used
  2531 with Isar theories; migration is usually quite simple with the ML
  2532 function use_legacy_bindings.  INCOMPATIBILITY.
  2533 
  2534 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2535 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2536 quotes.
  2537 
  2538 * Theory loader: be more serious about observing the static theory
  2539 header specifications (including optional directories), but not the
  2540 accidental file locations of previously successful loads.  The strict
  2541 update policy of former update_thy is now already performed by
  2542 use_thy, so the former has been removed; use_thys updates several
  2543 theories simultaneously, just as 'imports' within a theory header
  2544 specification, but without merging the results.  Potential
  2545 INCOMPATIBILITY: may need to refine theory headers and commands
  2546 ROOT.ML which depend on load order.
  2547 
  2548 * Theory loader: optional support for content-based file
  2549 identification, instead of the traditional scheme of full physical
  2550 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2551 (cf. the system manual).  The new scheme allows to work with
  2552 non-finished theories in persistent session images, such that source
  2553 files may be moved later on without requiring reloads.
  2554 
  2555 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2556 file (with the same base name as the theory) are considered a legacy
  2557 feature, which will disappear eventually. Even now, the theory loader
  2558 no longer maintains dependencies on such files.
  2559 
  2560 * Syntax: the scope for resolving ambiguities via type-inference is
  2561 now limited to individual terms, instead of whole simultaneous
  2562 specifications as before. This greatly reduces the complexity of the
  2563 syntax module and improves flexibility by separating parsing and
  2564 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2565 'fixes' etc.) are required in rare situations.
  2566 
  2567 * Syntax: constants introduced by new-style packages ('definition',
  2568 'abbreviation' etc.) are passed through the syntax module in
  2569 ``authentic mode''. This means that associated mixfix annotations
  2570 really stick to such constants, independently of potential name space
  2571 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2572 trees are represented slightly differently, may need to adapt syntax
  2573 translations accordingly. Use CONST marker in 'translations' and
  2574 @{const_syntax} antiquotation in 'parse_translation' etc.
  2575 
  2576 * Legacy goal package: reduced interface to the bare minimum required
  2577 to keep existing proof scripts running.  Most other user-level
  2578 functions are now part of the OldGoals structure, which is *not* open
  2579 by default (consider isatool expandshort before open OldGoals).
  2580 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2581 these tend to cause confusion about the actual goal (!) context being
  2582 used here, which is not necessarily the same as the_context().
  2583 
  2584 * Command 'find_theorems': supports "*" wild-card in "name:"
  2585 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2586 support a specific search form (see ProofGeneral/CHANGES).
  2587 
  2588 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2589 by default, which means that "prems" (and also "fixed variables") are
  2590 suppressed from proof state output.  Note that the ProofGeneral
  2591 settings mechanism allows to change and save options persistently, but
  2592 older versions of Isabelle will fail to start up if a negative prems
  2593 limit is imposed.
  2594 
  2595 * Local theory targets may be specified by non-nested blocks of
  2596 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2597 contain definitions, theorems etc., including any derived mechanism
  2598 that has been implemented on top of these primitives.  This concept
  2599 generalizes the existing ``theorem (in ...)'' towards more versatility
  2600 and scalability.
  2601 
  2602 * Proof General interface: proper undo of final 'end' command;
  2603 discontinued Isabelle/classic mode (ML proof scripts).
  2604 
  2605 
  2606 *** Document preparation ***
  2607 
  2608 * Added antiquotation @{theory name} which prints the given name,
  2609 after checking that it refers to a valid ancestor theory in the
  2610 current context.
  2611 
  2612 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2613 check the given source text as ML type/structure, printing verbatim.
  2614 
  2615 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2616 "c args == rhs" given in the current context.  (Any number of
  2617 arguments may be given on the LHS.)
  2618 
  2619 
  2620 *** Pure ***
  2621 
  2622 * The 'class' package offers a combination of axclass and locale to
  2623 achieve Haskell-like type classes in Isabelle.  Definitions and
  2624 theorems within a class context produce both relative results (with
  2625 implicit parameters according to the locale context), and polymorphic
  2626 constants with qualified polymorphism (according to the class
  2627 context).  Within the body context of a 'class' target, a separate
  2628 syntax layer ("user space type system") takes care of converting
  2629 between global polymorphic consts and internal locale representation.
  2630 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2631 "isatool doc classes" provides a tutorial.
  2632 
  2633 * Generic code generator framework allows to generate executable
  2634 code for ML and Haskell (including Isabelle classes).  A short usage
  2635 sketch:
  2636 
  2637     internal compilation:
  2638         export_code <list of constants (term syntax)> in SML
  2639     writing SML code to a file:
  2640         export_code <list of constants (term syntax)> in SML <filename>
  2641     writing OCaml code to a file:
  2642         export_code <list of constants (term syntax)> in OCaml <filename>
  2643     writing Haskell code to a bunch of files:
  2644         export_code <list of constants (term syntax)> in Haskell <filename>
  2645 
  2646     evaluating closed propositions to True/False using code generation:
  2647         method ``eval''
  2648 
  2649 Reasonable default setup of framework in HOL.
  2650 
  2651 Theorem attributs for selecting and transforming function equations theorems:
  2652 
  2653     [code fun]:        select a theorem as function equation for a specific constant
  2654     [code fun del]:    deselect a theorem as function equation for a specific constant
  2655     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2656     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2657 
  2658 User-defined serializations (target in {SML, OCaml, Haskell}):
  2659 
  2660     code_const <and-list of constants (term syntax)>
  2661       {(target) <and-list of const target syntax>}+
  2662 
  2663     code_type <and-list of type constructors>
  2664       {(target) <and-list of type target syntax>}+
  2665 
  2666     code_instance <and-list of instances>
  2667       {(target)}+
  2668         where instance ::= <type constructor> :: <class>
  2669 
  2670     code_class <and_list of classes>
  2671       {(target) <and-list of class target syntax>}+
  2672         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2673 
  2674 code_instance and code_class only are effective to target Haskell.
  2675 
  2676 For example usage see src/HOL/ex/Codegenerator.thy and
  2677 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2678 generation from Isabelle/HOL theories is available via "isatool doc
  2679 codegen".
  2680 
  2681 * Code generator: consts in 'consts_code' Isar commands are now
  2682 referred to by usual term syntax (including optional type
  2683 annotations).
  2684 
  2685 * Command 'no_translations' removes translation rules from theory
  2686 syntax.
  2687 
  2688 * Overloaded definitions are now actually checked for acyclic
  2689 dependencies.  The overloading scheme is slightly more general than
  2690 that of Haskell98, although Isabelle does not demand an exact
  2691 correspondence to type class and instance declarations.
  2692 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2693 exotic versions of overloading -- at the discretion of the user!
  2694 
  2695 Polymorphic constants are represented via type arguments, i.e. the
  2696 instantiation that matches an instance against the most general
  2697 declaration given in the signature.  For example, with the declaration
  2698 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2699 as c(nat).  Overloading is essentially simultaneous structural
  2700 recursion over such type arguments.  Incomplete specification patterns
  2701 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2702 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2703 Command 'print_theory' outputs the normalized system of recursive
  2704 equations, see section "definitions".
  2705 
  2706 * Configuration options are maintained within the theory or proof
  2707 context (with name and type bool/int/string), providing a very simple
  2708 interface to a poor-man's version of general context data.  Tools may
  2709 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2710 these values using Config.get etc.  Users may change options via an
  2711 associated attribute of the same name.  This form of context
  2712 declaration works particularly well with commands 'declare' or
  2713 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2714 very easy to avoid global references, which would not observe Isar
  2715 toplevel undo/redo and fail to work with multithreading.
  2716 
  2717 Various global ML references of Pure and HOL have been turned into
  2718 configuration options:
  2719 
  2720   Unify.search_bound		unify_search_bound
  2721   Unify.trace_bound		unify_trace_bound
  2722   Unify.trace_simp		unify_trace_simp
  2723   Unify.trace_types		unify_trace_types
  2724   Simplifier.simp_depth_limit	simp_depth_limit
  2725   Blast.depth_limit		blast_depth_limit
  2726   DatatypeProp.dtK		datatype_distinctness_limit
  2727   fast_arith_neq_limit  	fast_arith_neq_limit
  2728   fast_arith_split_limit	fast_arith_split_limit
  2729 
  2730 * Named collections of theorems may be easily installed as context
  2731 data using the functor NamedThmsFun (see also
  2732 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2733 attributes; there is also a toplevel print command.  This facility is
  2734 just a common case of general context data, which is the preferred way
  2735 for anything more complex than just a list of facts in canonical
  2736 order.
  2737 
  2738 * Isar: command 'declaration' augments a local theory by generic
  2739 declaration functions written in ML.  This enables arbitrary content
  2740 being added to the context, depending on a morphism that tells the
  2741 difference of the original declaration context wrt. the application
  2742 context encountered later on.
  2743 
  2744 * Isar: proper interfaces for simplification procedures.  Command
  2745 'simproc_setup' declares named simprocs (with match patterns, and body
  2746 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2747 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2748 
  2749 * Isar: an extra pair of brackets around attribute declarations
  2750 abbreviates a theorem reference involving an internal dummy fact,
  2751 which will be ignored later --- only the effect of the attribute on
  2752 the background context will persist.  This form of in-place
  2753 declarations is particularly useful with commands like 'declare' and
  2754 'using', for example ``have A using [[simproc a]] by simp''.
  2755 
  2756 * Isar: method "assumption" (and implicit closing of subproofs) now
  2757 takes simple non-atomic goal assumptions into account: after applying
  2758 an assumption as a rule the resulting subgoals are solved by atomic
  2759 assumption steps.  This is particularly useful to finish 'obtain'
  2760 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2761 without referring to the original premise "!!x. P x ==> thesis" in the
  2762 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2763 more permissive.
  2764 
  2765 * Isar: implicit use of prems from the Isar proof context is
  2766 considered a legacy feature.  Common applications like ``have A .''
  2767 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2768 referencing facts explicitly here improves readability and
  2769 maintainability of proof texts.
  2770 
  2771 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2772 the obtained context from the course of reasoning!  For example:
  2773 
  2774   assume "EX x y. A x & B y"   -- "any previous fact"
  2775   then guess x and y by clarify
  2776 
  2777 This technique is potentially adventurous, depending on the facts and
  2778 proof tools being involved here.
  2779 
  2780 * Isar: known facts from the proof context may be specified as literal
  2781 propositions, using ASCII back-quote syntax.  This works wherever
  2782 named facts used to be allowed so far, in proof commands, proof
  2783 methods, attributes etc.  Literal facts are retrieved from the context
  2784 according to unification of type and term parameters.  For example,
  2785 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2786 theorems in the current context, then these are valid literal facts:
  2787 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2788 
  2789 There is also a proof method "fact" which does the same composition
  2790 for explicit goal states, e.g. the following proof texts coincide with
  2791 certain special cases of literal facts:
  2792 
  2793   have "A" by fact                 ==  note `A`
  2794   have "A ==> B" by fact           ==  note `A ==> B`
  2795   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2796   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2797 
  2798 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2799 outer syntax.  Thus symbolic identifiers may be used without
  2800 additional white space in declarations like this: ``assume *: A''.
  2801 
  2802 * Isar: 'print_facts' prints all local facts of the current context,
  2803 both named and unnamed ones.
  2804 
  2805 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2806 
  2807   def x == "t" and y == "u"
  2808 
  2809 * Isar: added command 'unfolding', which is structurally similar to
  2810 'using', but affects both the goal state and facts by unfolding given
  2811 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2812 'unfolded' attribute may be replaced by first-class proof text.
  2813 
  2814 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2815 and command 'unfolding' now all support object-level equalities
  2816 (potentially conditional).  The underlying notion of rewrite rule is
  2817 analogous to the 'rule_format' attribute, but *not* that of the
  2818 Simplifier (which is usually more generous).
  2819 
  2820 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2821 premises of a theorem by n. Useful in conjunction with drule.
  2822 
  2823 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2824 method expression within a sandbox consisting of the first N
  2825 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2826 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2827 simplifies all new goals that emerge from applying rule foo to the
  2828 originally first one.
  2829 
  2830 * Isar: schematic goals are no longer restricted to higher-order
  2831 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2832 expected.
  2833 
  2834 * Isar: the conclusion of a long theorem statement is now either
  2835 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2836 (essentially a disjunction of cases with local parameters and
  2837 assumptions).  The latter allows to express general elimination rules
  2838 adequately; in this notation common elimination rules look like this:
  2839 
  2840   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2841     assumes "EX x. P x"
  2842     obtains x where "P x"
  2843 
  2844   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2845     assumes "A & B"
  2846     obtains A and B
  2847 
  2848   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2849     assumes "A | B"
  2850     obtains
  2851       A
  2852     | B
  2853 
  2854 The subsequent classical rules even refer to the formal "thesis"
  2855 explicitly:
  2856 
  2857   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2858     obtains "~ thesis"
  2859 
  2860   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2861     obtains "thesis ==> something"
  2862 
  2863 The actual proof of an 'obtains' statement is analogous to that of the
  2864 Isar proof element 'obtain', only that there may be several cases.
  2865 Optional case names may be specified in parentheses; these will be
  2866 available both in the present proof and as annotations in the
  2867 resulting rule, for later use with the 'cases' method (cf. attribute
  2868 case_names).
  2869 
  2870 * Isar: the assumptions of a long theorem statement are available as
  2871 "assms" fact in the proof context.  This is more appropriate than the
  2872 (historical) "prems", which refers to all assumptions of the current
  2873 context, including those from the target locale, proof body etc.
  2874 
  2875 * Isar: 'print_statement' prints theorems from the current theory or
  2876 proof context in long statement form, according to the syntax of a
  2877 top-level lemma.
  2878 
  2879 * Isar: 'obtain' takes an optional case name for the local context
  2880 introduction rule (default "that").
  2881 
  2882 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2883 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2884 to occur.
  2885 
  2886 * Pure: syntax "CONST name" produces a fully internalized constant
  2887 according to the current context.  This is particularly useful for
  2888 syntax translations that should refer to internal constant
  2889 representations independently of name spaces.
  2890 
  2891 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2892 instead of "FOO ". This allows multiple binder declarations to coexist
  2893 in the same context.  INCOMPATIBILITY.
  2894 
  2895 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2896 primitive that also works in a locale context (both for constants and
  2897 fixed variables). Type declaration and internal syntactic representation
  2898 of given constants retrieved from the context. Likewise, the
  2899 'no_notation' command allows to remove given syntax annotations from the
  2900 current context.
  2901 
  2902 * Isar/locales: new derived specification elements 'axiomatization',
  2903 'definition', 'abbreviation', which support type-inference, admit
  2904 object-level specifications (equality, equivalence).  See also the
  2905 isar-ref manual.  Examples:
  2906 
  2907   axiomatization
  2908     eq  (infix "===" 50) where
  2909     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2910 
  2911   definition "f x y = x + y + 1"
  2912   definition g where "g x = f x x"
  2913 
  2914   abbreviation
  2915     neq  (infix "=!=" 50) where
  2916     "x =!= y == ~ (x === y)"
  2917 
  2918 These specifications may be also used in a locale context.  Then the
  2919 constants being introduced depend on certain fixed parameters, and the
  2920 constant name is qualified by the locale base name.  An internal
  2921 abbreviation takes care for convenient input and output, making the
  2922 parameters implicit and using the original short name.  See also
  2923 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2924 entities from a monomorphic theory.
  2925 
  2926 Presently, abbreviations are only available 'in' a target locale, but
  2927 not inherited by general import expressions.  Also note that
  2928 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2929 'translations' in common applications.  The "no_abbrevs" print mode
  2930 prevents folding of abbreviations in term output.
  2931 
  2932 Concrete syntax is attached to specified constants in internal form,
  2933 independently of name spaces.  The parse tree representation is
  2934 slightly different -- use 'notation' instead of raw 'syntax', and
  2935 'translations' with explicit "CONST" markup to accommodate this.
  2936 
  2937 * Pure/Isar: unified syntax for new-style specification mechanisms
  2938 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2939 full type inference and dummy patterns ("_").  For example:
  2940 
  2941   definition "K x _ = x"
  2942 
  2943   inductive conj for A B
  2944   where "A ==> B ==> conj A B"
  2945 
  2946 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2947 the current context.  Print mode "no_abbrevs" prevents inversion of
  2948 abbreviations on output.
  2949 
  2950 * Isar/locales: improved parameter handling: use of locales "var" and
  2951 "struct" no longer necessary; - parameter renamings are no longer
  2952 required to be injective.  For example, this allows to define
  2953 endomorphisms as locale endom = homom mult mult h.
  2954 
  2955 * Isar/locales: changed the way locales with predicates are defined.
  2956 Instead of accumulating the specification, the imported expression is
  2957 now an interpretation.  INCOMPATIBILITY: different normal form of
  2958 locale expressions.  In particular, in interpretations of locales with
  2959 predicates, goals repesenting already interpreted fragments are not
  2960 removed automatically.  Use methods `intro_locales' and
  2961 `unfold_locales'; see below.
  2962 
  2963 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2964 provide backward reasoning on locales predicates.  The methods are
  2965 aware of interpretations and discharge corresponding goals.
  2966 `intro_locales' is less aggressive then `unfold_locales' and does not
  2967 unfold predicates to assumptions.
  2968 
  2969 * Isar/locales: the order in which locale fragments are accumulated
  2970 has changed.  This enables to override declarations from fragments due
  2971 to interpretations -- for example, unwanted simp rules.
  2972 
  2973 * Isar/locales: interpretation in theories and proof contexts has been
  2974 extended.  One may now specify (and prove) equations, which are
  2975 unfolded in interpreted theorems.  This is useful for replacing
  2976 defined concepts (constants depending on locale parameters) by
  2977 concepts already existing in the target context.  Example:
  2978 
  2979   interpretation partial_order ["op <= :: [int, int] => bool"]
  2980     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2981 
  2982 Typically, the constant `partial_order.less' is created by a
  2983 definition specification element in the context of locale
  2984 partial_order.
  2985 
  2986 * Method "induct": improved internal context management to support
  2987 local fixes and defines on-the-fly. Thus explicit meta-level
  2988 connectives !!  and ==> are rarely required anymore in inductive goals
  2989 (using object-logic connectives for this purpose has been long
  2990 obsolete anyway). Common proof patterns are explained in
  2991 src/HOL/Induct/Common_Patterns.thy, see also
  2992 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2993 examples.
  2994 
  2995 * Method "induct": improved handling of simultaneous goals. Instead of
  2996 introducing object-level conjunction, the statement is now split into
  2997 several conclusions, while the corresponding symbolic cases are nested
  2998 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2999 see src/HOL/Induct/Common_Patterns.thy, for example.
  3000 
  3001 * Method "induct": mutual induction rules are now specified as a list
  3002 of rule sharing the same induction cases. HOL packages usually provide
  3003 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3004 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3005 mutual induction rules differently, i.e. like this:
  3006 
  3007   (induct rule: foo_bar.inducts)
  3008   (induct set: foo bar)
  3009   (induct pred: foo bar)
  3010   (induct type: foo bar)
  3011 
  3012 The ML function ProjectRule.projections turns old-style rules into the
  3013 new format.
  3014 
  3015 * Method "coinduct": dual of induction, see
  3016 src/HOL/Library/Coinductive_List.thy for various examples.
  3017 
  3018 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3019 considered a legacy feature.
  3020 
  3021 * Attribute "symmetric" produces result with standardized schematic
  3022 variables (index 0).  Potential INCOMPATIBILITY.
  3023 
  3024 * Simplifier: by default the simplifier trace only shows top level
  3025 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3026 default. Thus there is less danger of being flooded by the trace. The
  3027 trace indicates where parts have been suppressed.
  3028   
  3029 * Provers/classical: removed obsolete classical version of elim_format
  3030 attribute; classical elim/dest rules are now treated uniformly when
  3031 manipulating the claset.
  3032 
  3033 * Provers/classical: stricter checks to ensure that supplied intro,
  3034 dest and elim rules are well-formed; dest and elim rules must have at
  3035 least one premise.
  3036 
  3037 * Provers/classical: attributes dest/elim/intro take an optional
  3038 weight argument for the rule (just as the Pure versions).  Weights are
  3039 ignored by automated tools, but determine the search order of single
  3040 rule steps.
  3041 
  3042 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3043 where the body does not mention the bound variable.  Note that dummy
  3044 patterns implicitly depend on their context of bounds, which makes
  3045 "{_. _}" match any set comprehension as expected.  Potential
  3046 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3047 constant "_idtdummy" in the binding position.
  3048 
  3049 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3050 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3051 for example "A -> B" => "Pi A (%_. B)".
  3052 
  3053 * Pure: 'class_deps' command visualizes the subclass relation, using
  3054 the graph browser tool.
  3055 
  3056 * Pure: 'print_theory' now suppresses certain internal declarations by
  3057 default; use '!' option for full details.
  3058 
  3059 
  3060 *** HOL ***
  3061 
  3062 * Method "metis" proves goals by applying the Metis general-purpose
  3063 resolution prover (see also http://gilith.com/software/metis/).
  3064 Examples are in the directory MetisExamples.  WARNING: the
  3065 Isabelle/HOL-Metis integration does not yet work properly with
  3066 multi-threading.
  3067   
  3068 * Command 'sledgehammer' invokes external automatic theorem provers as
  3069 background processes.  It generates calls to the "metis" method if
  3070 successful. These can be pasted into the proof.  Users do not have to
  3071 wait for the automatic provers to return.  WARNING: does not really
  3072 work with multi-threading.
  3073 
  3074 * New "auto_quickcheck" feature tests outermost goal statements for
  3075 potential counter-examples.  Controlled by ML references
  3076 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3077 5000 milliseconds).  Fails silently if statements is outside of
  3078 executable fragment, or any other codgenerator problem occurs.
  3079 
  3080 * New constant "undefined" with axiom "undefined x = undefined".
  3081 
  3082 * Added class "HOL.eq", allowing for code generation with polymorphic
  3083 equality.
  3084 
  3085 * Some renaming of class constants due to canonical name prefixing in
  3086 the new 'class' package:
  3087 
  3088     HOL.abs ~> HOL.abs_class.abs
  3089     HOL.divide ~> HOL.divide_class.divide
  3090     0 ~> HOL.zero_class.zero
  3091     1 ~> HOL.one_class.one
  3092     op + ~> HOL.plus_class.plus
  3093     op - ~> HOL.minus_class.minus
  3094     uminus ~> HOL.minus_class.uminus
  3095     op * ~> HOL.times_class.times
  3096     op < ~> HOL.ord_class.less
  3097     op <= > HOL.ord_class.less_eq
  3098     Nat.power ~> Power.power_class.power
  3099     Nat.size ~> Nat.size_class.size
  3100     Numeral.number_of ~> Numeral.number_class.number_of
  3101     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3102     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3103     Orderings.min ~> Orderings.ord_class.min
  3104     Orderings.max ~> Orderings.ord_class.max
  3105     Divides.op div ~> Divides.div_class.div
  3106     Divides.op mod ~> Divides.div_class.mod
  3107     Divides.op dvd ~> Divides.div_class.dvd
  3108 
  3109 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3110 
  3111 a) User-defined constants using any of the names "plus", "minus",
  3112 "times", "less" or "less_eq". The standard syntax translations for
  3113 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3114 names.
  3115 
  3116 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3117 INCOMPATIBILITY: use more specific names.
  3118 
  3119 c) Permutative equations (e.g. "a + b = b + a")
  3120 Since the change of names also changes the order of terms, permutative
  3121 rewrite rules may get applied in a different order. Experience shows
  3122 that this is rarely the case (only two adaptions in the whole Isabelle
  3123 distribution).  INCOMPATIBILITY: rewrite proofs
  3124 
  3125 d) ML code directly refering to constant names
  3126 This in general only affects hand-written proof tactics, simprocs and
  3127 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3128 Consider using @{const_name} antiquotation.
  3129 
  3130 * New class "default" with associated constant "default".
  3131 
  3132 * Function "sgn" is now overloaded and available on int, real, complex
  3133 (and other numeric types), using class "sgn".  Two possible defs of
  3134 sgn are given as equational assumptions in the classes sgn_if and
  3135 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3136 INCOMPATIBILITY.
  3137 
  3138 * Locale "partial_order" now unified with class "order" (cf. theory
  3139 Orderings), added parameter "less".  INCOMPATIBILITY.
  3140 
  3141 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3142 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3143 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3144 
  3145 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3146 changed order of proof goals in instance proofs.
  3147 
  3148 * The transitivity reasoner for partial and linear orders is set up
  3149 for classes "order" and "linorder".  Instances of the reasoner are available
  3150 in all contexts importing or interpreting the corresponding locales.
  3151 Method "order" invokes the reasoner separately; the reasoner
  3152 is also integrated with the Simplifier as a solver.  Diagnostic
  3153 command 'print_orders' shows the available instances of the reasoner
  3154 in the current context.
  3155 
  3156 * Localized monotonicity predicate in theory "Orderings"; integrated
  3157 lemmas max_of_mono and min_of_mono with this predicate.
  3158 INCOMPATIBILITY.
  3159 
  3160 * Formulation of theorem "dense" changed slightly due to integration
  3161 with new class dense_linear_order.
  3162 
  3163 * Uniform lattice theory development in HOL.
  3164 
  3165     constants "meet" and "join" now named "inf" and "sup"
  3166     constant "Meet" now named "Inf"
  3167 
  3168     classes "meet_semilorder" and "join_semilorder" now named
  3169       "lower_semilattice" and "upper_semilattice"
  3170     class "lorder" now named "lattice"
  3171     class "comp_lat" now named "complete_lattice"
  3172 
  3173     Instantiation of lattice classes allows explicit definitions
  3174     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3175 
  3176   INCOMPATIBILITY.  Theorem renames:
  3177 
  3178     meet_left_le            ~> inf_le1
  3179     meet_right_le           ~> inf_le2
  3180     join_left_le            ~> sup_ge1
  3181     join_right_le           ~> sup_ge2
  3182     meet_join_le            ~> inf_sup_ord
  3183     le_meetI                ~> le_infI
  3184     join_leI                ~> le_supI
  3185     le_meet                 ~> le_inf_iff
  3186     le_join                 ~> ge_sup_conv
  3187     meet_idempotent         ~> inf_idem
  3188     join_idempotent         ~> sup_idem
  3189     meet_comm               ~> inf_commute
  3190     join_comm               ~> sup_commute
  3191     meet_leI1               ~> le_infI1
  3192     meet_leI2               ~> le_infI2
  3193     le_joinI1               ~> le_supI1
  3194     le_joinI2               ~> le_supI2
  3195     meet_assoc              ~> inf_assoc
  3196     join_assoc              ~> sup_assoc
  3197     meet_left_comm          ~> inf_left_commute
  3198     meet_left_idempotent    ~> inf_left_idem
  3199     join_left_comm          ~> sup_left_commute
  3200     join_left_idempotent    ~> sup_left_idem
  3201     meet_aci                ~> inf_aci
  3202     join_aci                ~> sup_aci
  3203     le_def_meet             ~> le_iff_inf
  3204     le_def_join             ~> le_iff_sup
  3205     join_absorp2            ~> sup_absorb2
  3206     join_absorp1            ~> sup_absorb1
  3207     meet_absorp1            ~> inf_absorb1
  3208     meet_absorp2            ~> inf_absorb2
  3209     meet_join_absorp        ~> inf_sup_absorb
  3210     join_meet_absorp        ~> sup_inf_absorb
  3211     distrib_join_le         ~> distrib_sup_le
  3212     distrib_meet_le         ~> distrib_inf_le
  3213 
  3214     add_meet_distrib_left   ~> add_inf_distrib_left
  3215     add_join_distrib_left   ~> add_sup_distrib_left
  3216     is_join_neg_meet        ~> is_join_neg_inf
  3217     is_meet_neg_join        ~> is_meet_neg_sup
  3218     add_meet_distrib_right  ~> add_inf_distrib_right
  3219     add_join_distrib_right  ~> add_sup_distrib_right
  3220     add_meet_join_distribs  ~> add_sup_inf_distribs
  3221     join_eq_neg_meet        ~> sup_eq_neg_inf
  3222     meet_eq_neg_join        ~> inf_eq_neg_sup
  3223     add_eq_meet_join        ~> add_eq_inf_sup
  3224     meet_0_imp_0            ~> inf_0_imp_0
  3225     join_0_imp_0            ~> sup_0_imp_0
  3226     meet_0_eq_0             ~> inf_0_eq_0
  3227     join_0_eq_0             ~> sup_0_eq_0
  3228     neg_meet_eq_join        ~> neg_inf_eq_sup
  3229     neg_join_eq_meet        ~> neg_sup_eq_inf
  3230     join_eq_if              ~> sup_eq_if
  3231 
  3232     mono_meet               ~> mono_inf
  3233     mono_join               ~> mono_sup
  3234     meet_bool_eq            ~> inf_bool_eq
  3235     join_bool_eq            ~> sup_bool_eq
  3236     meet_fun_eq             ~> inf_fun_eq
  3237     join_fun_eq             ~> sup_fun_eq
  3238     meet_set_eq             ~> inf_set_eq
  3239     join_set_eq             ~> sup_set_eq
  3240     meet1_iff               ~> inf1_iff
  3241     meet2_iff               ~> inf2_iff
  3242     meet1I                  ~> inf1I
  3243     meet2I                  ~> inf2I
  3244     meet1D1                 ~> inf1D1
  3245     meet2D1                 ~> inf2D1
  3246     meet1D2                 ~> inf1D2
  3247     meet2D2                 ~> inf2D2
  3248     meet1E                  ~> inf1E
  3249     meet2E                  ~> inf2E
  3250     join1_iff               ~> sup1_iff
  3251     join2_iff               ~> sup2_iff
  3252     join1I1                 ~> sup1I1
  3253     join2I1                 ~> sup2I1
  3254     join1I1                 ~> sup1I1
  3255     join2I2                 ~> sup1I2
  3256     join1CI                 ~> sup1CI
  3257     join2CI                 ~> sup2CI
  3258     join1E                  ~> sup1E
  3259     join2E                  ~> sup2E
  3260 
  3261     is_meet_Meet            ~> is_meet_Inf
  3262     Meet_bool_def           ~> Inf_bool_def
  3263     Meet_fun_def            ~> Inf_fun_def
  3264     Meet_greatest           ~> Inf_greatest
  3265     Meet_lower              ~> Inf_lower
  3266     Meet_set_def            ~> Inf_set_def
  3267 
  3268     Sup_def                 ~> Sup_Inf
  3269     Sup_bool_eq             ~> Sup_bool_def
  3270     Sup_fun_eq              ~> Sup_fun_def
  3271     Sup_set_eq              ~> Sup_set_def
  3272 
  3273     listsp_meetI            ~> listsp_infI
  3274     listsp_meet_eq          ~> listsp_inf_eq
  3275 
  3276     meet_min                ~> inf_min
  3277     join_max                ~> sup_max
  3278 
  3279 * Added syntactic class "size"; overloaded constant "size" now has
  3280 type "'a::size ==> bool"
  3281 
  3282 * Internal reorganisation of `size' of datatypes: size theorems
  3283 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3284 simplification rules by default!); theorems "prod.size" now named
  3285 "*.size".
  3286 
  3287 * Class "div" now inherits from class "times" rather than "type".
  3288 INCOMPATIBILITY.
  3289 
  3290 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3291 Linorder etc.  have disappeared; operations defined in terms of
  3292 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3293 
  3294 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3295 
  3296 * HOL-Word: New extensive library and type for generic, fixed size
  3297 machine words, with arithemtic, bit-wise, shifting and rotating
  3298 operations, reflection into int, nat, and bool lists, automation for
  3299 linear arithmetic (by automatic reflection into nat or int), including
  3300 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3301 arithmetic type classes, supporting automatic simplification of
  3302 numerals on all operations.
  3303 
  3304 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3305 
  3306 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3307 
  3308 * Code generator library theories:
  3309   - Code_Integer represents HOL integers by big integer literals in target
  3310     languages.
  3311   - Code_Char represents HOL characters by character literals in target
  3312     languages.
  3313   - Code_Char_chr like Code_Char, but also offers treatment of character
  3314     codes; includes Code_Integer.
  3315   - Executable_Set allows to generate code for finite sets using lists.
  3316   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3317     denominator).
  3318   - Executable_Real implements a subset of real numbers, namly those
  3319     representable by rational numbers.
  3320   - Efficient_Nat implements natural numbers by integers, which in general will
  3321     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3322     includes Code_Integer.
  3323   - Code_Index provides an additional datatype index which is mapped to
  3324     target-language built-in integers.
  3325   - Code_Message provides an additional datatype message_string which is isomorphic to
  3326     strings; messages are mapped to target-language strings.
  3327 
  3328 * New package for inductive predicates
  3329 
  3330   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3331 
  3332     inductive
  3333       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3334       for z_1 :: U_1 and ... and z_n :: U_m
  3335     where
  3336       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3337     | ...
  3338 
  3339   with full support for type-inference, rather than
  3340 
  3341     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3342 
  3343     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3344     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3345 
  3346     inductive "s z_1 ... z_m"
  3347     intros
  3348       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3349       ...
  3350 
  3351   For backward compatibility, there is a wrapper allowing inductive
  3352   sets to be defined with the new package via
  3353 
  3354     inductive_set
  3355       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3356       for z_1 :: U_1 and ... and z_n :: U_m
  3357     where
  3358       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3359     | ...
  3360 
  3361   or
  3362 
  3363     inductive_set
  3364       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3365       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3366       for z_1 :: U_1 and ... and z_n :: U_m
  3367     where
  3368       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3369     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3370     | ...
  3371 
  3372   if the additional syntax "p ..." is required.
  3373 
  3374   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3375   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3376 
  3377   INCOMPATIBILITIES:
  3378 
  3379   - Since declaration and definition of inductive sets or predicates
  3380     is no longer separated, abbreviations involving the newly
  3381     introduced sets or predicates must be specified together with the
  3382     introduction rules after the 'where' keyword (see above), rather
  3383     than before the actual inductive definition.
  3384 
  3385   - The variables in induction and elimination rules are now
  3386     quantified in the order of their occurrence in the introduction
  3387     rules, rather than in alphabetical order. Since this may break
  3388     some proofs, these proofs either have to be repaired, e.g. by
  3389     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3390     statements of the form
  3391 
  3392       case (rule_i a_i_1 ... a_i_{k_i})
  3393 
  3394     or the old order of quantification has to be restored by explicitly adding
  3395     meta-level quantifiers in the introduction rules, i.e.
  3396 
  3397       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3398 
  3399   - The format of the elimination rules is now
  3400 
  3401       p z_1 ... z_m x_1 ... x_n ==>
  3402         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3403         ==> ... ==> P
  3404 
  3405     for predicates and
  3406 
  3407       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3408         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3409         ==> ... ==> P
  3410 
  3411     for sets rather than
  3412 
  3413       x : s z_1 ... z_m ==>
  3414         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3415         ==> ... ==> P
  3416 
  3417     This may require terms in goals to be expanded to n-tuples
  3418     (e.g. using case_tac or simplification with the split_paired_all
  3419     rule) before the above elimination rule is applicable.
  3420 
  3421   - The elimination or case analysis rules for (mutually) inductive
  3422     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3423     list of rules "p_1_..._p_k.elims" is no longer available.
  3424 
  3425 * New package "function"/"fun" for general recursive functions,
  3426 supporting mutual and nested recursion, definitions in local contexts,
  3427 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3428 for small examples, and the separate tutorial on the function
  3429 package. The old recdef "package" is still available as before, but
  3430 users are encouraged to use the new package.
  3431 
  3432 * Method "lexicographic_order" automatically synthesizes termination
  3433 relations as lexicographic combinations of size measures. 
  3434 
  3435 * Case-expressions allow arbitrary constructor-patterns (including
  3436 "_") and take their order into account, like in functional
  3437 programming.  Internally, this is translated into nested
  3438 case-expressions; missing cases are added and mapped to the predefined
  3439 constant "undefined". In complicated cases printing may no longer show
  3440 the original input but the internal form. Lambda-abstractions allow
  3441 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3442 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3443 variable.
  3444 
  3445 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3446 is an abbreviation for "of_nat :: nat => int". The simplification
  3447 rules for "of_nat" have been changed to work like "int" did
  3448 previously.  Potential INCOMPATIBILITY:
  3449   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3450   - of_nat_diff and of_nat_mult are no longer default simp rules
  3451 
  3452 * Method "algebra" solves polynomial equations over (semi)rings using
  3453 Groebner bases. The (semi)ring structure is defined by locales and the
  3454 tool setup depends on that generic context. Installing the method for
  3455 a specific type involves instantiating the locale and possibly adding
  3456 declarations for computation on the coefficients.  The method is
  3457 already instantiated for natural numbers and for the axiomatic class
  3458 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3459 CALCULEMUS 2007 for the general principles underlying this
  3460 architecture of context-aware proof-tools.
  3461 
  3462 * Method "ferrack" implements quantifier elimination over
  3463 special-purpose dense linear orders using locales (analogous to
  3464 "algebra"). The method is already installed for class
  3465 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3466 rat, etc.
  3467 
  3468 * Former constant "List.op @" now named "List.append".  Use ML
  3469 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3470 circumvent possible incompatibilities when working on ML level.
  3471 
  3472 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3473 
  3474 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3475 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3476 
  3477 * New syntax for Haskell-like list comprehension (input only), eg.
  3478 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3479 
  3480 * The special syntax for function "filter" has changed from [x :
  3481 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3482 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3483 
  3484 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3485 defined on nat only, as an abbreviation for [a..<Suc b]
  3486 INCOMPATIBILITY.
  3487 
  3488 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3489 
  3490 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3491 
  3492 * New lemma collection field_simps (an extension of ring_simps) for
  3493 manipulating (in)equations involving division. Multiplies with all
  3494 denominators that can be proved to be non-zero (in equations) or
  3495 positive/negative (in inequations).
  3496 
  3497 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3498 have been improved and renamed to ring_simps, group_simps and
  3499 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3500 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3501 
  3502 * Theory Library/Commutative_Ring: switched from recdef to function
  3503 package; constants add, mul, pow now curried.  Infix syntax for
  3504 algebraic operations.
  3505 
  3506 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3507 INCOMPATIBILITY.
  3508 
  3509 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3510 INCOMPATIBILITY.
  3511 
  3512 * HOL/records: generalised field-update to take a function on the
  3513 field rather than the new value: r(|A := x|) is translated to A_update
  3514 (K x) r The K-combinator that is internally used is called K_record.
  3515 INCOMPATIBILITY: Usage of the plain update functions has to be
  3516 adapted.
  3517  
  3518 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3519 * x = 0, which are required for a semiring.  Richer structures do not
  3520 inherit from semiring_0 anymore, because this property is a theorem
  3521 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3522 there is more to prove, but this is mostly trivial.
  3523 
  3524 * Class "recpower" is generalized to arbitrary monoids, not just
  3525 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3526 commutativity or semiring properties additionally.
  3527 
  3528 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3529 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3530 better use 'abbreviation'.
  3531 
  3532 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3533 
  3534 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3535 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3536 significant changes for setting up numeral syntax for types:
  3537   - New constants Numeral.pred and Numeral.succ instead
  3538       of former Numeral.bin_pred and Numeral.bin_succ.
  3539   - Use integer operations instead of bin_add, bin_mult and so on.
  3540   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3541   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3542 
  3543 See src/HOL/Integ/IntArith.thy for an example setup.
  3544 
  3545 * Command 'normal_form' computes the normal form of a term that may
  3546 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3547 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3548 heavy-duty computations because the functions are compiled to ML
  3549 first.  Correspondingly, a method "normalization" is provided.  See
  3550 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3551 
  3552 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3553 25 like -->); output depends on the "iff" print_mode, the default is
  3554 "A = B" (with priority 50).
  3555 
  3556 * Relations less (<) and less_eq (<=) are also available on type bool.
  3557 Modified syntax to disallow nesting without explicit parentheses,
  3558 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3559 INCOMPATIBILITY.
  3560 
  3561 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3562 
  3563 * Relation composition operator "op O" now has precedence 75 and binds
  3564 stronger than union and intersection. INCOMPATIBILITY.
  3565 
  3566 * The old set interval syntax "{m..n(}" (and relatives) has been
  3567 removed.  Use "{m..<n}" (and relatives) instead.
  3568 
  3569 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3570 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3571 ``declare [[simproc del: neq]]''.
  3572 
  3573 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3574 True/False.
  3575 
  3576 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3577 
  3578 * Theorem setsum_mult renamed to setsum_right_distrib.
  3579 
  3580 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3581 ``rule'' method.
  3582 
  3583 * Reimplemented methods "sat" and "satx", with several improvements:
  3584 goals no longer need to be stated as "<prems> ==> False", equivalences
  3585 (i.e. "=" on type bool) are handled, variable names of the form
  3586 "lit_<n>" are no longer reserved, significant speedup.
  3587 
  3588 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3589 zChaff is still supported as well.
  3590 
  3591 * 'inductive' and 'datatype': provide projections of mutual rules,
  3592 bundled as foo_bar.inducts;
  3593 
  3594 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3595 Library.
  3596 
  3597 * Library: moved theory Accessible_Part to main HOL.
  3598 
  3599 * Library: added theory Coinductive_List of potentially infinite lists
  3600 as greatest fixed-point.
  3601 
  3602 * Library: added theory AssocList which implements (finite) maps as
  3603 association lists.
  3604 
  3605 * Method "evaluation" solves goals (i.e. a boolean expression)
  3606 efficiently by compiling it to ML.  The goal is "proved" (via an
  3607 oracle) if it evaluates to True.
  3608 
  3609 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3610 also when invoked by the simplifier.  This results in the Simplifier
  3611 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3612 Configuration option fast_arith_split_limit=0 recovers the old
  3613 behavior.
  3614 
  3615 * Support for hex (0x20) and binary (0b1001) numerals.
  3616 
  3617 * New method: reify eqs (t), where eqs are equations for an
  3618 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3619 parameter, computes a term s::'b and a list xs::'a list and proves the
  3620 theorem I xs s = t. This is also known as reification or quoting. The
  3621 resulting theorem is applied to the subgoal to substitute t with I xs
  3622 s.  If t is omitted, the subgoal itself is reified.
  3623 
  3624 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3625 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3626 where f is supposed to be a computable function (in the sense of code
  3627 generattion). The method uses reify to compute s and xs as above then
  3628 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3629 r and finally gets the theorem t = r, which is again applied to the
  3630 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3631 
  3632 * Reflection: Automatic reification now handels binding, an example is
  3633 available in src/HOL/ex/ReflectionEx.thy
  3634 
  3635 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3636 command 'statespace' that is similar to 'record', but introduces an
  3637 abstract specification based on the locale infrastructure instead of
  3638 HOL types.  This leads to extra flexibility in composing state spaces,
  3639 in particular multiple inheritance and renaming of components.
  3640 
  3641 
  3642 *** HOL-Complex ***
  3643 
  3644 * Hyperreal: Functions root and sqrt are now defined on negative real
  3645 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3646 Nonnegativity side conditions have been removed from many lemmas, so
  3647 that more subgoals may now be solved by simplification; potential
  3648 INCOMPATIBILITY.
  3649 
  3650 * Real: new type classes formalize real normed vector spaces and
  3651 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3652 and norm :: 'a => real.
  3653 
  3654 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3655 reals into other types. The overloaded constant Reals :: 'a set is now
  3656 defined as range of_real; potential INCOMPATIBILITY.
  3657 
  3658 * Real: proper support for ML code generation, including 'quickcheck'.
  3659 Reals are implemented as arbitrary precision rationals.
  3660 
  3661 * Hyperreal: Several constants that previously worked only for the
  3662 reals have been generalized, so they now work over arbitrary vector
  3663 spaces. Type annotations may need to be added in some cases; potential
  3664 INCOMPATIBILITY.
  3665 
  3666   Infinitesimal  :: ('a::real_normed_vector) star set
  3667   HFinite        :: ('a::real_normed_vector) star set
  3668   HInfinite      :: ('a::real_normed_vector) star set
  3669   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3670   monad          :: ('a::real_normed_vector) star => 'a star set
  3671   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3672   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3673   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3674   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3675   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3676   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3677   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3678   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3679   sgn            :: 'a::real_normed_vector => 'a
  3680   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3681 
  3682 * Complex: Some complex-specific constants are now abbreviations for
  3683 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3684 hnorm.  Other constants have been entirely removed in favor of the
  3685 polymorphic versions (INCOMPATIBILITY):
  3686 
  3687   approx        <-- capprox
  3688   HFinite       <-- CFinite
  3689   HInfinite     <-- CInfinite
  3690   Infinitesimal <-- CInfinitesimal
  3691   monad         <-- cmonad
  3692   galaxy        <-- cgalaxy
  3693   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3694   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3695   (ns)deriv     <-- (ns)cderiv
  3696 
  3697 
  3698 *** HOL-Algebra ***
  3699 
  3700 * Formalisation of ideals and the quotient construction over rings.
  3701 
  3702 * Order and lattice theory no longer based on records.
  3703 INCOMPATIBILITY.
  3704 
  3705 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3706 greatest_closed.  INCOMPATIBILITY.
  3707 
  3708 * Method algebra is now set up via an attribute.  For examples see
  3709 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3710 of algebraic structures.
  3711 
  3712 * Renamed theory CRing to Ring.
  3713 
  3714 
  3715 *** HOL-Nominal ***
  3716 
  3717 * Substantial, yet incomplete support for nominal datatypes (binding
  3718 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3719 src/HOL/Nominal/Examples.  Prospective users should consult
  3720 http://isabelle.in.tum.de/nominal/
  3721 
  3722 
  3723 *** ML ***
  3724 
  3725 * ML basics: just one true type int, which coincides with IntInf.int
  3726 (even on SML/NJ).
  3727 
  3728 * ML within Isar: antiquotations allow to embed statically-checked
  3729 formal entities in the source, referring to the context available at
  3730 compile-time.  For example:
  3731 
  3732 ML {* @{sort "{zero,one}"} *}
  3733 ML {* @{typ "'a => 'b"} *}
  3734 ML {* @{term "%x. x"} *}
  3735 ML {* @{prop "x == y"} *}
  3736 ML {* @{ctyp "'a => 'b"} *}
  3737 ML {* @{cterm "%x. x"} *}
  3738 ML {* @{cprop "x == y"} *}
  3739 ML {* @{thm asm_rl} *}
  3740 ML {* @{thms asm_rl} *}
  3741 ML {* @{type_name c} *}
  3742 ML {* @{type_syntax c} *}
  3743 ML {* @{const_name c} *}
  3744 ML {* @{const_syntax c} *}
  3745 ML {* @{context} *}
  3746 ML {* @{theory} *}
  3747 ML {* @{theory Pure} *}
  3748 ML {* @{theory_ref} *}
  3749 ML {* @{theory_ref Pure} *}
  3750 ML {* @{simpset} *}
  3751 ML {* @{claset} *}
  3752 ML {* @{clasimpset} *}
  3753 
  3754 The same works for sources being ``used'' within an Isar context.
  3755 
  3756 * ML in Isar: improved error reporting; extra verbosity with
  3757 ML_Context.trace enabled.
  3758 
  3759 * Pure/General/table.ML: the join operations now works via exceptions
  3760 DUP/SAME instead of type option. This is simpler in simple cases, and
  3761 admits slightly more efficient complex applications.
  3762 
  3763 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3764 use Context.generic instead of just theory.
  3765 
  3766 * Pure: datatype Context.generic joins theory/Proof.context and
  3767 provides some facilities for code that works in either kind of
  3768 context, notably GenericDataFun for uniform theory and proof data.
  3769 
  3770 * Pure: simplified internal attribute type, which is now always
  3771 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3772 local (Proof.context) attributes have been discontinued, while
  3773 minimizing code duplication. Thm.rule_attribute and
  3774 Thm.declaration_attribute build canonical attributes; see also structure
  3775 Context for further operations on Context.generic, notably
  3776 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3777 declarations and definitions.
  3778 
  3779 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3780 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3781 init only required for impure data. INCOMPATIBILITY: empty really need
  3782 to be empty (no dependencies on theory content!)
  3783 
  3784 * Pure/kernel: consts certification ignores sort constraints given in
  3785 signature declarations. (This information is not relevant to the
  3786 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3787 potential INCOMPATIBILITY.
  3788 
  3789 * Pure: axiomatic type classes are now purely definitional, with
  3790 explicit proofs of class axioms and super class relations performed
  3791 internally. See Pure/axclass.ML for the main internal interfaces --
  3792 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3793 AxClass.axiomatize_class/classrel/arity supersede
  3794 Sign.add_classes/classrel/arities.
  3795 
  3796 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3797 global/local versions on theory vs. Proof.context have been
  3798 discontinued; Attrib.syntax and Method.syntax have been adapted
  3799 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3800 attributes, methods, etc.
  3801 
  3802 * Pure: several functions of signature "... -> theory -> theory * ..."
  3803 have been reoriented to "... -> theory -> ... * theory" in order to
  3804 allow natural usage in combination with the ||>, ||>>, |-> and
  3805 fold_map combinators.
  3806 
  3807 * Pure: official theorem names (closed derivations) and additional
  3808 comments (tags) are now strictly separate.  Name hints -- which are
  3809 maintained as tags -- may be attached any time without affecting the
  3810 derivation.
  3811 
  3812 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3813 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3814 achieve the old behaviour.
  3815 
  3816 * Pure: the "Goal" constant is now called "prop", supporting a
  3817 slightly more general idea of ``protecting'' meta-level rule
  3818 statements.
  3819 
  3820 * Pure: Logic.(un)varify only works in a global context, which is now
  3821 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3822 Logic.legacy_(un)varify as temporary workaround.
  3823 
  3824 * Pure: structure Name provides scalable operations for generating
  3825 internal variable names, notably Name.variants etc.  This replaces
  3826 some popular functions from term.ML:
  3827 
  3828   Term.variant		->  Name.variant
  3829   Term.variantlist	->  Name.variant_list
  3830   Term.invent_names	->  Name.invent_list
  3831 
  3832 Note that low-level renaming rarely occurs in new code -- operations
  3833 from structure Variable are used instead (see below).
  3834 
  3835 * Pure: structure Variable provides fundamental operations for proper
  3836 treatment of fixed/schematic variables in a context.  For example,
  3837 Variable.import introduces fixes for schematics of given facts and
  3838 Variable.export reverses the effect (up to renaming) -- this replaces
  3839 various freeze_thaw operations.
  3840 
  3841 * Pure: structure Goal provides simple interfaces for
  3842 init/conclude/finish and tactical prove operations (replacing former
  3843 Tactic.prove).  Goal.prove is the canonical way to prove results
  3844 within a given context; Goal.prove_global is a degraded version for
  3845 theory level goals, including a global Drule.standard.  Note that
  3846 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3847 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3848 in a locale context).
  3849 
  3850 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3851 and type checking (Syntax.check_term etc.), with common combinations
  3852 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3853 which are considered legacy and await removal.
  3854 
  3855 * Pure/Syntax: generic interfaces for type unchecking
  3856 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3857 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3858 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3859 available for convenience, but refer to the very same operations using
  3860 a mere theory instead of a full context.
  3861 
  3862 * Isar: simplified treatment of user-level errors, using exception
  3863 ERROR of string uniformly.  Function error now merely raises ERROR,
  3864 without any side effect on output channels.  The Isar toplevel takes
  3865 care of proper display of ERROR exceptions.  ML code may use plain
  3866 handle/can/try; cat_error may be used to concatenate errors like this:
  3867 
  3868   ... handle ERROR msg => cat_error msg "..."
  3869 
  3870 Toplevel ML code (run directly or through the Isar toplevel) may be
  3871 embedded into the Isar toplevel with exception display/debug like
  3872 this:
  3873 
  3874   Isar.toplevel (fn () => ...)
  3875 
  3876 INCOMPATIBILITY, removed special transform_error facilities, removed
  3877 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3878 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3879 -- use plain ERROR instead.
  3880 
  3881 * Isar: theory setup now has type (theory -> theory), instead of a
  3882 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3883 
  3884 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3885 ProofContext.debug/verbose flags.
  3886 
  3887 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3888 theory before entering a proof state.  Transactions now always see a
  3889 quasi-functional intermediate checkpoint, both in interactive and
  3890 batch mode.
  3891 
  3892 * Isar: simplified interfaces for outer syntax.  Renamed
  3893 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3894 OuterSyntax.add_parsers -- this functionality is now included in
  3895 OuterSyntax.command etc.  INCOMPATIBILITY.
  3896 
  3897 * Simplifier: the simpset of a running simplification process now
  3898 contains a proof context (cf. Simplifier.the_context), which is the
  3899 very context that the initial simpset has been retrieved from (by
  3900 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3901 (solver, looper etc.) may depend on arbitrary proof data.
  3902 
  3903 * Simplifier.inherit_context inherits the proof context (plus the
  3904 local bounds) of the current simplification process; any simproc
  3905 etc. that calls the Simplifier recursively should do this!  Removed
  3906 former Simplifier.inherit_bounds, which is already included here --
  3907 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3908 specify an explicit context using Simplifier.context/theory_context.
  3909 
  3910 * Simplifier/Classical Reasoner: more abstract interfaces
  3911 change_simpset/claset for modifying the simpset/claset reference of a
  3912 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3913 INCOMPATIBILITY.
  3914 
  3915 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3916 "Trueprop" etc.
  3917 
  3918 
  3919 *** System ***
  3920 
  3921 * settings: the default heap location within ISABELLE_HOME_USER now
  3922 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3923 Isabelle installations.
  3924 
  3925 * isabelle-process: option -S (secure mode) disables some critical
  3926 operations, notably runtime compilation and evaluation of ML source
  3927 code.
  3928 
  3929 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3930 
  3931 * Support for parallel execution, using native multicore support of
  3932 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3933 independent theories, according to the given theory header
  3934 specifications. The maximum number of worker threads is specified via
  3935 usedir option -M or the "max-threads" setting in Proof General. A
  3936 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3937 to 6 on a 8-core machine.  User-code needs to observe certain
  3938 guidelines for thread-safe programming, see appendix A in the Isar
  3939 Implementation manual.
  3940 
  3941 
  3942 
  3943 New in Isabelle2005 (October 2005)
  3944 ----------------------------------
  3945 
  3946 *** General ***
  3947 
  3948 * Theory headers: the new header syntax for Isar theories is
  3949 
  3950   theory <name>
  3951   imports <theory1> ... <theoryN>
  3952   uses <file1> ... <fileM>
  3953   begin
  3954 
  3955 where the 'uses' part is optional.  The previous syntax
  3956 
  3957   theory <name> = <theory1> + ... + <theoryN>:
  3958 
  3959 will disappear in the next release.  Use isatool fixheaders to convert
  3960 existing theory files.  Note that there is no change in ancient
  3961 non-Isar theories now, but these will disappear soon.
  3962 
  3963 * Theory loader: parent theories can now also be referred to via
  3964 relative and absolute paths.
  3965 
  3966 * Command 'find_theorems' searches for a list of criteria instead of a
  3967 list of constants. Known criteria are: intro, elim, dest, name:string,
  3968 simp:term, and any term. Criteria can be preceded by '-' to select
  3969 theorems that do not match. Intro, elim, dest select theorems that
  3970 match the current goal, name:s selects theorems whose fully qualified
  3971 name contain s, and simp:term selects all simplification rules whose
  3972 lhs match term.  Any other term is interpreted as pattern and selects
  3973 all theorems matching the pattern. Available in ProofGeneral under
  3974 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3975 
  3976   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3977 
  3978 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3979 matching the current goal as introduction rule and not having "HOL."
  3980 in their name (i.e. not being defined in theory HOL).
  3981 
  3982 * Command 'thms_containing' has been discontinued in favour of
  3983 'find_theorems'; INCOMPATIBILITY.
  3984 
  3985 * Communication with Proof General is now 8bit clean, which means that
  3986 Unicode text in UTF-8 encoding may be used within theory texts (both
  3987 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3988 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3989 
  3990   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3991   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3992 
  3993 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3994 Classical Reasoner.  Typical big applications run around 2 times
  3995 faster.
  3996 
  3997 
  3998 *** Document preparation ***
  3999 
  4000 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4001 of raw sources.  Only those symbols that do not require additional
  4002 LaTeX packages (depending on comments in isabellesym.sty) are
  4003 displayed properly, everything else is left verbatim.  isatool display
  4004 and isatool print are used as front ends (these are subject to the
  4005 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4006 
  4007 * Command tags control specific markup of certain regions of text,
  4008 notably folding and hiding.  Predefined tags include "theory" (for
  4009 theory begin and end), "proof" for proof commands, and "ML" for
  4010 commands involving ML code; the additional tags "visible" and
  4011 "invisible" are unused by default.  Users may give explicit tag
  4012 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4013 interpretation of tags is determined by the LaTeX job during document
  4014 preparation: see option -V of isatool usedir, or options -n and -t of
  4015 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4016 \isadroptag.
  4017 
  4018 Several document versions may be produced at the same time via isatool
  4019 usedir (the generated index.html will link all of them).  Typical
  4020 specifications include ''-V document=theory,proof,ML'' to present
  4021 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4022 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4023 these parts without any formal replacement text.  The Isabelle site
  4024 default settings produce ''document'' and ''outline'' versions as
  4025 specified above.
  4026 
  4027 * Several new antiquotations:
  4028 
  4029   @{term_type term} prints a term with its type annotated;
  4030 
  4031   @{typeof term} prints the type of a term;
  4032 
  4033   @{const const} is the same as @{term const}, but checks that the
  4034   argument is a known logical constant;
  4035 
  4036   @{term_style style term} and @{thm_style style thm} print a term or
  4037   theorem applying a "style" to it
  4038 
  4039   @{ML text}
  4040 
  4041 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4042 definitions, equations, inequations etc., 'concl' printing only the
  4043 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4044 to print the specified premise.  TermStyle.add_style provides an ML
  4045 interface for introducing further styles.  See also the "LaTeX Sugar"
  4046 document practical applications.  The ML antiquotation prints
  4047 type-checked ML expressions verbatim.
  4048 
  4049 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4050 and 'text' support optional locale specification '(in loc)', which
  4051 specifies the default context for interpreting antiquotations.  For
  4052 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4053 
  4054 * Option 'locale=NAME' of antiquotations specifies an alternative
  4055 context interpreting the subsequent argument.  For example: @{thm
  4056 [locale=lattice] inf_assoc}.
  4057 
  4058 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4059 a proof context.
  4060 
  4061 * Proper output of antiquotations for theory commands involving a
  4062 proof context (such as 'locale' or 'theorem (in loc) ...').
  4063 
  4064 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4065 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4066 
  4067 * isatool usedir: new option -C (default true) controls whether option
  4068 -D should include a copy of the original document directory; -C false
  4069 prevents unwanted effects such as copying of administrative CVS data.
  4070 
  4071 
  4072 *** Pure ***
  4073 
  4074 * Considerably improved version of 'constdefs' command.  Now performs
  4075 automatic type-inference of declared constants; additional support for
  4076 local structure declarations (cf. locales and HOL records), see also
  4077 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4078 sequential dependencies of definitions within a single 'constdefs'
  4079 section; moreover, the declared name needs to be an identifier.  If
  4080 all fails, consider to fall back on 'consts' and 'defs' separately.
  4081 
  4082 * Improved indexed syntax and implicit structures.  First of all,
  4083 indexed syntax provides a notational device for subscripted
  4084 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4085 expressions.  Secondly, in a local context with structure
  4086 declarations, number indexes \<^sub>n or the empty index (default
  4087 number 1) refer to a certain fixed variable implicitly; option
  4088 show_structs controls printing of implicit structures.  Typical
  4089 applications of these concepts involve record types and locales.
  4090 
  4091 * New command 'no_syntax' removes grammar declarations (and
  4092 translations) resulting from the given syntax specification, which is
  4093 interpreted in the same manner as for the 'syntax' command.
  4094 
  4095 * 'Advanced' translation functions (parse_translation etc.) may depend
  4096 on the signature of the theory context being presently used for
  4097 parsing/printing, see also isar-ref manual.
  4098 
  4099 * Improved 'oracle' command provides a type-safe interface to turn an
  4100 ML expression of type theory -> T -> term into a primitive rule of
  4101 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4102 is already included here); see also FOL/ex/IffExample.thy;
  4103 INCOMPATIBILITY.
  4104 
  4105 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4106 before); "cI" is no longer bound, use "c.intro" instead.
  4107 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4108 axclasses vs. locales.
  4109 
  4110 * Improved internal renaming of symbolic identifiers -- attach primes
  4111 instead of base 26 numbers.
  4112 
  4113 * New flag show_question_marks controls printing of leading question
  4114 marks in schematic variable names.
  4115 
  4116 * In schematic variable names, *any* symbol following \<^isub> or
  4117 \<^isup> is now treated as part of the base name.  For example, the
  4118 following works without printing of awkward ".0" indexes:
  4119 
  4120   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4121     by simp
  4122 
  4123 * Inner syntax includes (*(*nested*) comments*).
  4124 
  4125 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4126 annotations as "(00...)".
  4127 
  4128 * Clear separation of logical types and nonterminals, where the latter
  4129 may only occur in 'syntax' specifications or type abbreviations.
  4130 Before that distinction was only partially implemented via type class
  4131 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4132 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4133 exotic syntax specifications may require further adaption
  4134 (e.g. Cube/Cube.thy).
  4135 
  4136 * Removed obsolete type class "logic", use the top sort {} instead.
  4137 Note that non-logical types should be declared as 'nonterminals'
  4138 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4139 specifications.
  4140 
  4141 * Attributes 'induct' and 'cases': type or set names may now be
  4142 locally fixed variables as well.
  4143 
  4144 * Simplifier: can now control the depth to which conditional rewriting
  4145 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4146 Limit.
  4147 
  4148 * Simplifier: simplification procedures may now take the current
  4149 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4150 interface), which is very useful for calling the Simplifier
  4151 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4152 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4153 low-level mk_simproc no longer applies Logic.varify internally, to
  4154 allow for use in a context of fixed variables.
  4155 
  4156 * thin_tac now works even if the assumption being deleted contains !!
  4157 or ==>.  More generally, erule now works even if the major premise of
  4158 the elimination rule contains !! or ==>.
  4159 
  4160 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4161 
  4162 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4163 from Pure, which contains all common declarations already.  Both
  4164 theories are defined via plain Isabelle/Isar .thy files.
  4165 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4166 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4167 use isatool fixcpure to adapt your theory and ML sources.
  4168 
  4169 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4170 selections of theorems in named facts via index ranges.
  4171 
  4172 * 'print_theorems': in theory mode, really print the difference
  4173 wrt. the last state (works for interactive theory development only),
  4174 in proof mode print all local facts (cf. 'print_facts');
  4175 
  4176 * 'hide': option '(open)' hides only base names.
  4177 
  4178 * More efficient treatment of intermediate checkpoints in interactive
  4179 theory development.
  4180 
  4181 * Code generator is now invoked via code_module (incremental code
  4182 generation) and code_library (modular code generation, ML structures
  4183 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4184 must be quoted when used as identifiers.
  4185 
  4186 * New 'value' command for reading, evaluating and printing terms using
  4187 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4188 quoted when used as identifier.
  4189 
  4190 
  4191 *** Locales ***
  4192 
  4193 * New commands for the interpretation of locale expressions in
  4194 theories (1), locales (2) and proof contexts (3).  These generate
  4195 proof obligations from the expression specification.  After the
  4196 obligations have been discharged, theorems of the expression are added
  4197 to the theory, target locale or proof context.  The synopsis of the
  4198 commands is a follows:
  4199 
  4200   (1) interpretation expr inst
  4201   (2) interpretation target < expr
  4202   (3) interpret expr inst
  4203 
  4204 Interpretation in theories and proof contexts require a parameter
  4205 instantiation of terms from the current context.  This is applied to
  4206 specifications and theorems of the interpreted expression.
  4207 Interpretation in locales only permits parameter renaming through the
  4208 locale expression.  Interpretation is smart in that interpretations
  4209 that are active already do not occur in proof obligations, neither are
  4210 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4211 inspect active interpretations of a particular locale.  For details,
  4212 see the Isar Reference manual.  Examples can be found in
  4213 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4214 
  4215 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4216 'interpret' instead.
  4217 
  4218 * New context element 'constrains' for adding type constraints to
  4219 parameters.
  4220 
  4221 * Context expressions: renaming of parameters with syntax
  4222 redeclaration.
  4223 
  4224 * Locale declaration: 'includes' disallowed.
  4225 
  4226 * Proper static binding of attribute syntax -- i.e. types / terms /
  4227 facts mentioned as arguments are always those of the locale definition
  4228 context, independently of the context of later invocations.  Moreover,
  4229 locale operations (renaming and type / term instantiation) are applied
  4230 to attribute arguments as expected.
  4231 
  4232 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4233 actual attributes; rare situations may require Attrib.attribute to
  4234 embed those attributes into Attrib.src that lack concrete syntax.
  4235 Attribute implementations need to cooperate properly with the static
  4236 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4237 Attrib.XXX_thm etc. already do the right thing without further
  4238 intervention.  Only unusual applications -- such as "where" or "of"
  4239 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4240 on the context and the facts involved -- may have to assign parsed
  4241 values to argument tokens explicitly.
  4242 
  4243 * Changed parameter management in theorem generation for long goal
  4244 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4245 theorem statement in rare situations.
  4246 
  4247 * Locale inspection command 'print_locale' omits notes elements.  Use
  4248 'print_locale!' to have them included in the output.
  4249 
  4250 
  4251 *** Provers ***
  4252 
  4253 * Provers/hypsubst.ML: improved version of the subst method, for
  4254 single-step rewriting: it now works in bound variable contexts. New is
  4255 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4256 rewrite a different subterm than the original subst method, which is
  4257 still available as 'simplesubst'.
  4258 
  4259 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4260 and quasi orders.
  4261 
  4262 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4263 reflexive-transitive closure of relations.
  4264 
  4265 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4266 limit (previously hard-coded with a value of 20) user-definable.
  4267 
  4268 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4269 is peformed already.  Object-logics merely need to finish their
  4270 initial simpset configuration as before.  INCOMPATIBILITY.
  4271 
  4272 
  4273 *** HOL ***
  4274 
  4275 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4276 
  4277   syntax (epsilon)
  4278     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4279 
  4280 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4281 and x-symbol; use option '-m epsilon' to get it actually printed.
  4282 Moreover, the mathematically important symbolic identifier \<epsilon>
  4283 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4284 
  4285 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4286 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4287 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4288 support corresponding Isar calculations.
  4289 
  4290 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4291 instead of ":".
  4292 
  4293 * theory SetInterval: changed the syntax for open intervals:
  4294 
  4295   Old       New
  4296   {..n(}    {..<n}
  4297   {)n..}    {n<..}
  4298   {m..n(}   {m..<n}
  4299   {)m..n}   {m<..n}
  4300   {)m..n(}  {m<..<n}
  4301 
  4302 The old syntax is still supported but will disappear in the next
  4303 release.  For conversion use the following Emacs search and replace
  4304 patterns (these are not perfect but work quite well):
  4305 
  4306   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4307   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4308 
  4309 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4310 equalities in commutative rings; method 'algebra' provides a generic
  4311 interface.
  4312 
  4313 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4314 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4315 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4316 be a tuple pattern.
  4317 
  4318 Some new syntax forms are available:
  4319 
  4320   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4321   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4322   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4323   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4324 
  4325 The latter form "\<Sum>x < k. e" used to be based on a separate
  4326 function "Summation", which has been discontinued.
  4327 
  4328 * theory Finite_Set: in structured induction proofs, the insert case
  4329 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4330 (insert F x)'.
  4331 
  4332 * The 'refute' command has been extended to support a much larger
  4333 fragment of HOL, including axiomatic type classes, constdefs and
  4334 typedefs, inductive datatypes and recursion.
  4335 
  4336 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4337 Requires zChaff with proof generation to be installed.  See
  4338 HOL/ex/SAT_Examples.thy for examples.
  4339 
  4340 * Datatype induction via method 'induct' now preserves the name of the
  4341 induction variable. For example, when proving P(xs::'a list) by
  4342 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4343 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4344 in unstructured proof scripts.
  4345 
  4346 * Reworked implementation of records.  Improved scalability for
  4347 records with many fields, avoiding performance problems for type
  4348 inference. Records are no longer composed of nested field types, but
  4349 of nested extension types. Therefore the record type only grows linear
  4350 in the number of extensions and not in the number of fields.  The
  4351 top-level (users) view on records is preserved.  Potential
  4352 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4353 old record representation. The type generated for a record is called
  4354 <record_name>_ext_type.
  4355 
  4356 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4357 proofs triggered by a record definition or a simproc (if
  4358 quick_and_dirty is enabled).  Definitions of large records can take
  4359 quite long.
  4360 
  4361 New simproc record_upd_simproc for simplification of multiple record
  4362 updates enabled by default.  Moreover, trivial updates are also
  4363 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4364 occasionally, since simplification is more powerful by default.
  4365 
  4366 * typedef: proper support for polymorphic sets, which contain extra
  4367 type-variables in the term.
  4368 
  4369 * Simplifier: automatically reasons about transitivity chains
  4370 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4371 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4372 old proofs break occasionally as simplification may now solve more
  4373 goals than previously.
  4374 
  4375 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4376 present.  Works for all partial orders (class "order"), in particular
  4377 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4378 just like y <= x.
  4379 
  4380 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4381 bound variable or a constant then the let is unfolded.  Otherwise
  4382 first a is simplified to b, and then f b is simplified to g. If
  4383 possible we abstract b from g arriving at "let x = b in h x",
  4384 otherwise we unfold the let and arrive at g.  The simproc can be
  4385 enabled/disabled by the reference use_let_simproc.  Potential
  4386 INCOMPATIBILITY since simplification is more powerful by default.
  4387 
  4388 * Classical reasoning: the meson method now accepts theorems as arguments.
  4389 
  4390 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4391 jobs to provide advice on the provability of subgoals.
  4392 
  4393 * Theory OrderedGroup and Ring_and_Field: various additions and
  4394 improvements to faciliate calculations involving equalities and
  4395 inequalities.
  4396 
  4397 The following theorems have been eliminated or modified
  4398 (INCOMPATIBILITY):
  4399 
  4400   abs_eq             now named abs_of_nonneg
  4401   abs_of_ge_0        now named abs_of_nonneg
  4402   abs_minus_eq       now named abs_of_nonpos
  4403   imp_abs_id         now named abs_of_nonneg
  4404   imp_abs_neg_id     now named abs_of_nonpos
  4405   mult_pos           now named mult_pos_pos
  4406   mult_pos_le        now named mult_nonneg_nonneg
  4407   mult_pos_neg_le    now named mult_nonneg_nonpos
  4408   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4409   mult_neg           now named mult_neg_neg
  4410   mult_neg_le        now named mult_nonpos_nonpos
  4411 
  4412 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4413      
  4414      zero_le_square
  4415      not_square_less_zero 
  4416 
  4417   The following lemmas have been deleted from Real/RealPow:
  4418   
  4419      realpow_zero_zero
  4420      realpow_two
  4421      realpow_less
  4422      zero_le_power
  4423      realpow_two_le
  4424      abs_realpow_two
  4425      realpow_two_abs     
  4426 
  4427 * Theory Parity: added rules for simplifying exponents.
  4428 
  4429 * Theory List:
  4430 
  4431 The following theorems have been eliminated or modified
  4432 (INCOMPATIBILITY):
  4433 
  4434   list_all_Nil       now named list_all.simps(1)
  4435   list_all_Cons      now named list_all.simps(2)
  4436   list_all_conv      now named list_all_iff
  4437   set_mem_eq         now named mem_iff
  4438 
  4439 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4440 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4441 
  4442 
  4443 *** HOL-Complex ***
  4444 
  4445 * Theory RealDef: better support for embedding natural numbers and
  4446 integers in the reals.
  4447 
  4448 The following theorems have been eliminated or modified
  4449 (INCOMPATIBILITY):
  4450 
  4451   exp_ge_add_one_self  now requires no hypotheses
  4452   real_of_int_add      reversed direction of equality (use [symmetric])
  4453   real_of_int_minus    reversed direction of equality (use [symmetric])
  4454   real_of_int_diff     reversed direction of equality (use [symmetric])
  4455   real_of_int_mult     reversed direction of equality (use [symmetric])
  4456 
  4457 * Theory RComplete: expanded support for floor and ceiling functions.
  4458 
  4459 * Theory Ln is new, with properties of the natural logarithm
  4460 
  4461 * Hyperreal: There is a new type constructor "star" for making
  4462 nonstandard types.  The old type names are now type synonyms:
  4463 
  4464   hypreal = real star
  4465   hypnat = nat star
  4466   hcomplex = complex star
  4467 
  4468 * Hyperreal: Many groups of similarly-defined constants have been
  4469 replaced by polymorphic versions (INCOMPATIBILITY):
  4470 
  4471   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4472 
  4473   starset      <-- starsetNat, starsetC
  4474   *s*          <-- *sNat*, *sc*
  4475   starset_n    <-- starsetNat_n, starsetC_n
  4476   *sn*         <-- *sNatn*, *scn*
  4477   InternalSets <-- InternalNatSets, InternalCSets
  4478 
  4479   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4480   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4481   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4482   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4483   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4484 
  4485 * Hyperreal: Many type-specific theorems have been removed in favor of
  4486 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4487 
  4488   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4489   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4490   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4491   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4492   right_minus <-- hypreal_add_minus
  4493   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4494   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4495   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4496   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4497   mult_1_right <-- hcomplex_mult_one_right
  4498   mult_zero_left <-- hcomplex_mult_zero_left
  4499   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4500   right_distrib <-- hypnat_add_mult_distrib2
  4501   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4502   right_inverse <-- hypreal_mult_inverse
  4503   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4504   order_refl <-- {hypreal,hypnat}_le_refl
  4505   order_trans <-- {hypreal,hypnat}_le_trans
  4506   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4507   order_less_le <-- {hypreal,hypnat}_less_le
  4508   linorder_linear <-- {hypreal,hypnat}_le_linear
  4509   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4510   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4511   add_nonneg_nonneg <-- hypreal_le_add_order
  4512 
  4513 * Hyperreal: Separate theorems having to do with type-specific
  4514 versions of constants have been merged into theorems that apply to the
  4515 new polymorphic constants (INCOMPATIBILITY):
  4516 
  4517   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4518   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4519   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4520   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4521   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4522   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4523   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4524   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4525   STAR_diff <-- {STAR,STARC}_diff
  4526   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4527     STARC_hcomplex_of_complex}_image_subset
  4528   starset_n_Un <-- starset{Nat,C}_n_Un
  4529   starset_n_Int <-- starset{Nat,C}_n_Int
  4530   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4531   starset_n_diff <-- starset{Nat,C}_n_diff
  4532   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4533   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4534   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4535   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4536   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4537   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4538   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4539   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4540   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4541   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4542   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4543   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4544   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4545   starfun_diff <-- starfun{C,RC,CR}_diff
  4546   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4547   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4548   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4549   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4550   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4551   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4552   starfun_Id <-- starfunC_Id
  4553   starfun_approx <-- starfun{Nat,CR}_approx
  4554   starfun_capprox <-- starfun{C,RC}_capprox
  4555   starfun_abs <-- starfunNat_rabs
  4556   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4557   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4558   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4559   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4560   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4561   starfun_add_approx <-- starfunCR_add_approx
  4562   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4563   starfun_divide <-- starfun{C,CR,RC}_divide
  4564   starfun_n <-- starfun{Nat,C}_n
  4565   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4566   starfun_n_add <-- starfun{Nat,C}_n_add
  4567   starfun_n_add_minus <-- starfunNat_n_add_minus
  4568   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4569   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4570   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4571 
  4572   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4573   star_n_minus <-- {hypreal,hcomplex}_minus
  4574   star_n_diff <-- {hypreal,hcomplex}_diff
  4575   star_n_mult <-- {hypreal,hcomplex}_mult
  4576   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4577   star_n_le <-- {hypreal,hypnat}_le
  4578   star_n_less <-- {hypreal,hypnat}_less
  4579   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4580   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4581   star_n_abs <-- hypreal_hrabs
  4582   star_n_divide <-- hcomplex_divide
  4583 
  4584   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4585   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4586   star_of_diff <-- hypreal_of_real_diff
  4587   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4588   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4589   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4590   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4591   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4592   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4593   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4594   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4595   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4596   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4597   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4598   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4599   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4600   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4601   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4602   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4603   star_of_power <-- hypreal_of_real_power
  4604   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4605 
  4606 * Hyperreal: new method "transfer" that implements the transfer
  4607 principle of nonstandard analysis. With a subgoal that mentions
  4608 nonstandard types like "'a star", the command "apply transfer"
  4609 replaces it with an equivalent one that mentions only standard types.
  4610 To be successful, all free variables must have standard types; non-
  4611 standard variables must have explicit universal quantifiers.
  4612 
  4613 * Hyperreal: A theory of Taylor series.
  4614 
  4615 
  4616 *** HOLCF ***
  4617 
  4618 * Discontinued special version of 'constdefs' (which used to support
  4619 continuous functions) in favor of the general Pure one with full
  4620 type-inference.
  4621 
  4622 * New simplification procedure for solving continuity conditions; it
  4623 is much faster on terms with many nested lambda abstractions (cubic
  4624 instead of exponential time).
  4625 
  4626 * New syntax for domain package: selector names are now optional.
  4627 Parentheses should be omitted unless argument is lazy, for example:
  4628 
  4629   domain 'a stream = cons "'a" (lazy "'a stream")
  4630 
  4631 * New command 'fixrec' for defining recursive functions with pattern
  4632 matching; defining multiple functions with mutual recursion is also
  4633 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4634 sinr, or any data constructor defined by the domain package. The given
  4635 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4636 syntax and examples.
  4637 
  4638 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4639 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4640 but the proof obligation additionally includes an admissibility
  4641 requirement. The packages generate instances of class cpo or pcpo,
  4642 with continuity and strictness theorems for Rep and Abs.
  4643 
  4644 * HOLCF: Many theorems have been renamed according to a more standard naming
  4645 scheme (INCOMPATIBILITY):
  4646 
  4647   foo_inject:  "foo$x = foo$y ==> x = y"
  4648   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4649   foo_less:    "(foo$x << foo$y) = (x << y)"
  4650   foo_strict:  "foo$UU = UU"
  4651   foo_defined: "... ==> foo$x ~= UU"
  4652   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4653 
  4654 
  4655 *** ZF ***
  4656 
  4657 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4658 including the First Isomorphism Theorem (on quotienting by the kernel
  4659 of a homomorphism).
  4660 
  4661 * ZF/Simplifier: install second copy of type solver that actually
  4662 makes use of TC rules declared to Isar proof contexts (or locales);
  4663 the old version is still required for ML proof scripts.
  4664 
  4665 
  4666 *** Cube ***
  4667 
  4668 * Converted to Isar theory format; use locales instead of axiomatic
  4669 theories.
  4670 
  4671 
  4672 *** ML ***
  4673 
  4674 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4675 for ||>, ||>>, |>>,
  4676 
  4677 * Pure/library.ML no longer defines its own option datatype, but uses
  4678 that of the SML basis, which has constructors NONE and SOME instead of
  4679 None and Some, as well as exception Option.Option instead of OPTION.
  4680 The functions the, if_none, is_some, is_none have been adapted
  4681 accordingly, while Option.map replaces apsome.
  4682 
  4683 * Pure/library.ML: the exception LIST has been given up in favour of
  4684 the standard exceptions Empty and Subscript, as well as
  4685 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4686 superceded by the standard hd and tl functions etc.
  4687 
  4688 A number of basic list functions are no longer exported to the ML
  4689 toplevel, as they are variants of predefined functions.  The following
  4690 suggests how one can translate existing code:
  4691 
  4692     rev_append xs ys = List.revAppend (xs, ys)
  4693     nth_elem (i, xs) = List.nth (xs, i)
  4694     last_elem xs = List.last xs
  4695     flat xss = List.concat xss
  4696     seq fs = List.app fs
  4697     partition P xs = List.partition P xs
  4698     mapfilter f xs = List.mapPartial f xs
  4699 
  4700 * Pure/library.ML: several combinators for linear functional
  4701 transformations, notably reverse application and composition:
  4702 
  4703   x |> f                f #> g
  4704   (x, y) |-> f          f #-> g
  4705 
  4706 * Pure/library.ML: introduced/changed precedence of infix operators:
  4707 
  4708   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4709   infix 2 ?;
  4710   infix 3 o oo ooo oooo;
  4711   infix 4 ~~ upto downto;
  4712 
  4713 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4714 infix operators.
  4715 
  4716 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4717 fold_map support linear functional transformations and nesting.  For
  4718 example:
  4719 
  4720   fold f [x1, ..., xN] y =
  4721     y |> f x1 |> ... |> f xN
  4722 
  4723   (fold o fold) f [xs1, ..., xsN] y =
  4724     y |> fold f xs1 |> ... |> fold f xsN
  4725 
  4726   fold f [x1, ..., xN] =
  4727     f x1 #> ... #> f xN
  4728 
  4729   (fold o fold) f [xs1, ..., xsN] =
  4730     fold f xs1 #> ... #> fold f xsN
  4731 
  4732 * Pure/library.ML: the following selectors on type 'a option are
  4733 available:
  4734 
  4735   the:               'a option -> 'a  (*partial*)
  4736   these:             'a option -> 'a  where 'a = 'b list
  4737   the_default: 'a -> 'a option -> 'a
  4738   the_list:          'a option -> 'a list
  4739 
  4740 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4741 basic operations for association lists, following natural argument
  4742 order; moreover the explicit equality predicate passed here avoids
  4743 potentially expensive polymorphic runtime equality checks.
  4744 The old functions may be expressed as follows:
  4745 
  4746   assoc = uncurry (AList.lookup (op =))
  4747   assocs = these oo AList.lookup (op =)
  4748   overwrite = uncurry (AList.update (op =)) o swap
  4749 
  4750 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4751 
  4752   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4753   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4754 
  4755 replacing make_keylist and keyfilter (occassionally used)
  4756 Naive rewrites:
  4757 
  4758   make_keylist = AList.make
  4759   keyfilter = AList.find (op =)
  4760 
  4761 * eq_fst and eq_snd now take explicit equality parameter, thus
  4762   avoiding eqtypes. Naive rewrites:
  4763 
  4764     eq_fst = eq_fst (op =)
  4765     eq_snd = eq_snd (op =)
  4766 
  4767 * Removed deprecated apl and apr (rarely used).
  4768   Naive rewrites:
  4769 
  4770     apl (n, op) =>>= curry op n
  4771     apr (op, m) =>>= fn n => op (n, m)
  4772 
  4773 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4774 provides a reasonably efficient light-weight implementation of sets as
  4775 lists.
  4776 
  4777 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4778 few new operations; existing lookup and update are now curried to
  4779 follow natural argument order (for use with fold etc.);
  4780 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4781 
  4782 * Pure/General: output via the Isabelle channels of
  4783 writeln/warning/error etc. is now passed through Output.output, with a
  4784 hook for arbitrary transformations depending on the print_mode
  4785 (cf. Output.add_mode -- the first active mode that provides a output
  4786 function wins).  Already formatted output may be embedded into further
  4787 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4788 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4789 accommodate easy composition of diagnostic messages etc.  Programmers
  4790 rarely need to care about Output.output or Output.raw at all, with
  4791 some notable exceptions: Output.output is required when bypassing the
  4792 standard channels (writeln etc.), or in token translations to produce
  4793 properly formatted results; Output.raw is required when capturing
  4794 already output material that will eventually be presented to the user
  4795 a second time.  For the default print mode, both Output.output and
  4796 Output.raw have no effect.
  4797 
  4798 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4799 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4800 cumulative results are displayed at the end of a batch session.
  4801 
  4802 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4803 replaced by File.platform_path and File.shell_path (with appropriate
  4804 hooks).  This provides a clean interface for unusual systems where the
  4805 internal and external process view of file names are different.
  4806 
  4807 * Pure: more efficient orders for basic syntactic entities: added
  4808 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4809 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4810 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4811 orders now -- potential INCOMPATIBILITY for code that depends on a
  4812 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4813 Library.sort_strings on result).
  4814 
  4815 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4816 fold_types traverse types/terms from left to right, observing natural
  4817 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4818 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4819 
  4820 * Pure: name spaces have been refined, with significant changes of the
  4821 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4822 to extern(_table).  The plain name entry path is superceded by a
  4823 general 'naming' context, which also includes the 'policy' to produce
  4824 a fully qualified name and external accesses of a fully qualified
  4825 name; NameSpace.extend is superceded by context dependent
  4826 Sign.declare_name.  Several theory and proof context operations modify
  4827 the naming context.  Especially note Theory.restore_naming and
  4828 ProofContext.restore_naming to get back to a sane state; note that
  4829 Theory.add_path is no longer sufficient to recover from
  4830 Theory.absolute_path in particular.
  4831 
  4832 * Pure: new flags short_names (default false) and unique_names
  4833 (default true) for controlling output of qualified names.  If
  4834 short_names is set, names are printed unqualified.  If unique_names is
  4835 reset, the name prefix is reduced to the minimum required to achieve
  4836 the original result when interning again, even if there is an overlap
  4837 with earlier declarations.
  4838 
  4839 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4840 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4841 (useful for printing error messages).  INCOMPATIBILITY.
  4842 
  4843 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4844 Theory.theory are now identified, referring to the universal
  4845 Context.theory (see Pure/context.ML).  Actual signature and theory
  4846 content is managed as theory data.  The old code and interfaces were
  4847 spread over many files and structures; the new arrangement introduces
  4848 considerable INCOMPATIBILITY to gain more clarity:
  4849 
  4850   Context -- theory management operations (name, identity, inclusion,
  4851     parents, ancestors, merge, etc.), plus generic theory data;
  4852 
  4853   Sign -- logical signature and syntax operations (declaring consts,
  4854     types, etc.), plus certify/read for common entities;
  4855 
  4856   Theory -- logical theory operations (stating axioms, definitions,
  4857     oracles), plus a copy of logical signature operations (consts,
  4858     types, etc.); also a few basic management operations (Theory.copy,
  4859     Theory.merge, etc.)
  4860 
  4861 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4862 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4863 for convenience -- they merely return the theory.
  4864 
  4865 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4866 
  4867 * Pure: the Isar proof context type is already defined early in Pure
  4868 as Context.proof (note that ProofContext.context and Proof.context are
  4869 aliases, where the latter is the preferred name).  This enables other
  4870 Isabelle components to refer to that type even before Isar is present.
  4871 
  4872 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4873 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4874 any of these kinds.  For example, Sign.intern typeK is now
  4875 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4876 Theory.hide_types.  Also note that former
  4877 Theory.hide_classes/types/consts are now
  4878 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4879 internalize their arguments!  INCOMPATIBILITY.
  4880 
  4881 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4882 datatype thmref (with constructors Name and NameSelection) instead of
  4883 plain string -- INCOMPATIBILITY;
  4884 
  4885 * Pure: cases produced by proof methods specify options, where NONE
  4886 means to remove case bindings -- INCOMPATIBILITY in
  4887 (RAW_)METHOD_CASES.
  4888 
  4889 * Pure: the following operations retrieve axioms or theorems from a
  4890 theory node or theory hierarchy, respectively:
  4891 
  4892   Theory.axioms_of: theory -> (string * term) list
  4893   Theory.all_axioms_of: theory -> (string * term) list
  4894   PureThy.thms_of: theory -> (string * thm) list
  4895   PureThy.all_thms_of: theory -> (string * thm) list
  4896 
  4897 * Pure: print_tac now outputs the goal through the trace channel.
  4898 
  4899 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4900 Reference Toplevel.debug (default false) controls detailed printing
  4901 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4902 controls execution profiling -- set to 1 for time and 2 for space
  4903 (both increase the runtime).
  4904 
  4905 * Isar session: The initial use of ROOT.ML is now always timed,
  4906 i.e. the log will show the actual process times, in contrast to the
  4907 elapsed wall-clock time that the outer shell wrapper produces.
  4908 
  4909 * Simplifier: improved handling of bound variables (nameless
  4910 representation, avoid allocating new strings).  Simprocs that invoke
  4911 the Simplifier recursively should use Simplifier.inherit_bounds to
  4912 avoid local name clashes.  Failure to do so produces warnings
  4913 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4914 for further details.
  4915 
  4916 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4917 bindings for all theorems stored within a given theory; this may help
  4918 in porting non-Isar theories to Isar ones, while keeping ML proof
  4919 scripts for the time being.
  4920 
  4921 * ML operator HTML.with_charset specifies the charset begin used for
  4922 generated HTML files.  For example:
  4923 
  4924   HTML.with_charset "utf-8" use_thy "Hebrew";
  4925   HTML.with_charset "utf-8" use_thy "Chinese";
  4926 
  4927 
  4928 *** System ***
  4929 
  4930 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4931 isabelle, isatool etc.).
  4932 
  4933 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4934 isatool doc, isatool mkdir, display_drafts etc.).
  4935 
  4936 * isatool usedir: option -f allows specification of the ML file to be
  4937 used by Isabelle; default is ROOT.ML.
  4938 
  4939 * New isatool version outputs the version identifier of the Isabelle
  4940 distribution being used.
  4941 
  4942 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4943 (containing Boolean satisfiability problems) into Isabelle/HOL
  4944 theories.
  4945 
  4946 
  4947 
  4948 New in Isabelle2004 (April 2004)
  4949 --------------------------------
  4950 
  4951 *** General ***
  4952 
  4953 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4954   Replaces linorder.ML.
  4955 
  4956 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4957   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4958   (\<a>...\<z>), are now considered normal letters, and can therefore
  4959   be used anywhere where an ASCII letter (a...zA...Z) has until
  4960   now. COMPATIBILITY: This obviously changes the parsing of some
  4961   terms, especially where a symbol has been used as a binder, say
  4962   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4963   as an identifier.  Fix it by inserting a space around former
  4964   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4965   existing theory and ML files.
  4966 
  4967 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4968 
  4969 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4970   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4971   a normal (but invisible) letter. For multiple letter subscripts repeat
  4972   \<^isub> like this: x\<^isub>1\<^isub>2.
  4973 
  4974 * Pure: There are now sub-/superscripts that can span more than one
  4975   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4976   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4977   superscript. The new control characters are not identifier parts.
  4978 
  4979 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4980   content of "..." to the latex file instead of \isacntrl... . The "..."
  4981   may consist of any printable characters excluding the end bracket >.
  4982 
  4983 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4984   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4985   declare constants "final", which prevents their being given a definition
  4986   later.  It is useful for constants whose behaviour is fixed axiomatically
  4987   rather than definitionally, such as the meta-logic connectives.
  4988 
  4989 * Pure: 'instance' now handles general arities with general sorts
  4990   (i.e. intersections of classes),
  4991 
  4992 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4993   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4994   It can be changed to alter the colors/layout of generated pages.
  4995 
  4996 
  4997 *** Isar ***
  4998 
  4999 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5000   cut_tac, subgoal_tac and thin_tac:
  5001   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5002     locales are no longer forced to write Isar proof scripts.
  5003     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5004     emulations.
  5005   - INCOMPATIBILITY: names of variables to be instantiated may no
  5006     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5007     This is consistent with the instantiation attribute "where".
  5008 
  5009 * Attributes "where" and "of":
  5010   - Now take type variables of instantiated theorem into account when reading
  5011     the instantiation string.  This fixes a bug that caused instantiated
  5012     theorems to have too special types in some circumstances.
  5013   - "where" permits explicit instantiations of type variables.
  5014 
  5015 * Calculation commands "moreover" and "also" no longer interfere with
  5016   current facts ("this"), admitting arbitrary combinations with "then"
  5017   and derived forms.
  5018 
  5019 * Locales:
  5020   - Goal statements involving the context element "includes" no longer
  5021     generate theorems with internal delta predicates (those ending on
  5022     "_axioms") in the premise.
  5023     Resolve particular premise with <locale>.intro to obtain old form.
  5024   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5025     specification and "includes" elements in goal statement.
  5026   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5027     [intro?] and [elim?] (respectively) by default.
  5028   - Experimental command for instantiation of locales in proof contexts:
  5029         instantiate <label>[<attrs>]: <loc>
  5030     Instantiates locale <loc> and adds all its theorems to the current context
  5031     taking into account their attributes.  Label and attrs are optional
  5032     modifiers, like in theorem declarations.  If present, names of
  5033     instantiated theorems are qualified with <label>, and the attributes
  5034     <attrs> are applied after any attributes these theorems might have already.
  5035       If the locale has assumptions, a chained fact of the form
  5036     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5037     are derived.  The command does not support old-style locales declared
  5038     with "locale (open)".
  5039       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5040 
  5041 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5042   (Isar) contexts.
  5043 
  5044 
  5045 *** HOL ***
  5046 
  5047 * Proof import: new image HOL4 contains the imported library from
  5048   the HOL4 system with about 2500 theorems. It is imported by
  5049   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5050   can be used like any other Isabelle image.  See
  5051   HOL/Import/HOL/README for more information.
  5052 
  5053 * Simplifier:
  5054   - Much improved handling of linear and partial orders.
  5055     Reasoners for linear and partial orders are set up for type classes
  5056     "linorder" and "order" respectively, and are added to the default simpset
  5057     as solvers.  This means that the simplifier can build transitivity chains
  5058     to solve goals from the assumptions.
  5059   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5060     of blast or auto after simplification become unnecessary because the goal
  5061     is solved by simplification already.
  5062 
  5063 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5064     all proved in axiomatic type classes for semirings, rings and fields.
  5065 
  5066 * Numerics:
  5067   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5068     now formalized using the Ring_and_Field theory mentioned above.
  5069   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5070     than before, because now they are set up once in a generic manner.
  5071   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5072     Look for the general versions in Ring_and_Field (and Power if they concern
  5073     exponentiation).
  5074 
  5075 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5076 
  5077 * Records:
  5078   - Record types are now by default printed with their type abbreviation
  5079     instead of the list of all field types. This can be configured via
  5080     the reference "print_record_type_abbr".
  5081   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5082     (not enabled by default).
  5083   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5084     EX x. x = sel r to True (not enabled by default).
  5085   - Tactic "record_split_simp_tac" to split and simplify records added.
  5086 
  5087 * 'specification' command added, allowing for definition by
  5088   specification.  There is also an 'ax_specification' command that
  5089   introduces the new constants axiomatically.
  5090 
  5091 * arith(_tac) is now able to generate counterexamples for reals as well.
  5092 
  5093 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5094 
  5095 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5096   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5097 
  5098 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5099   matrix theory to linear programming.
  5100 
  5101 * Unions and Intersections:
  5102   The latex output syntax of UN and INT has been changed
  5103   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5104   i.e. the index formulae has become a subscript.
  5105   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5106 
  5107 * Unions and Intersections over Intervals:
  5108   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5109   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5110   like in normal math, and corresponding versions for < and for intersection.
  5111 
  5112 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5113   lexicographic dictonary ordering has been added as "lexord".
  5114 
  5115 * ML: the legacy theory structures Int and List have been removed. They had
  5116   conflicted with ML Basis Library structures having the same names.
  5117 
  5118 * 'refute' command added to search for (finite) countermodels.  Only works
  5119   for a fragment of HOL.  The installation of an external SAT solver is
  5120   highly recommended.  See "HOL/Refute.thy" for details.
  5121 
  5122 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5123   formulae under an assignment of free variables to random values.
  5124   In contrast to 'refute', it can deal with inductive datatypes,
  5125   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5126   for examples.
  5127 
  5128 
  5129 *** HOLCF ***
  5130 
  5131 * Streams now come with concatenation and are part of the HOLCF image
  5132 
  5133 
  5134 
  5135 New in Isabelle2003 (May 2003)
  5136 ------------------------------
  5137 
  5138 *** General ***
  5139 
  5140 * Provers/simplifier:
  5141 
  5142   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5143     Assumptions are now subject to complete mutual simplification,
  5144     not just from left to right. The simplifier now preserves
  5145     the order of assumptions.
  5146 
  5147     Potential INCOMPATIBILITY:
  5148 
  5149     -- simp sometimes diverges where the old version did
  5150        not, e.g. invoking simp on the goal
  5151 
  5152         [| P (f x); y = x; f x = f y |] ==> Q
  5153 
  5154        now gives rise to the infinite reduction sequence
  5155 
  5156         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5157 
  5158        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5159        kind of problem.
  5160 
  5161     -- Tactics combining classical reasoner and simplification (such as auto)
  5162        are also affected by this change, because many of them rely on
  5163        simp. They may sometimes diverge as well or yield a different numbers
  5164        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5165        in case of problems. Sometimes subsequent calls to the classical
  5166        reasoner will fail because a preceeding call to the simplifier too
  5167        eagerly simplified the goal, e.g. deleted redundant premises.
  5168 
  5169   - The simplifier trace now shows the names of the applied rewrite rules
  5170 
  5171   - You can limit the number of recursive invocations of the simplifier
  5172     during conditional rewriting (where the simplifie tries to solve the
  5173     conditions before applying the rewrite rule):
  5174     ML "simp_depth_limit := n"
  5175     where n is an integer. Thus you can force termination where previously
  5176     the simplifier would diverge.
  5177 
  5178   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5179 
  5180   - No longer aborts on failed congruence proof.  Instead, the
  5181     congruence is ignored.
  5182 
  5183 * Pure: New generic framework for extracting programs from constructive
  5184   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5185   as HOL/Extraction for some case studies.
  5186 
  5187 * Pure: The main goal of the proof state is no longer shown by default, only
  5188 the subgoals. This behaviour is controlled by a new flag.
  5189    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5190 (ML: Proof.show_main_goal).
  5191 
  5192 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5193 rules whose conclusion matches subgoal 1:
  5194       PG menu: Isabelle/Isar -> Show me -> matching rules
  5195 The rules are ordered by how closely they match the subgoal.
  5196 In particular, rules that solve a subgoal outright are displayed first
  5197 (or rather last, the way they are printed).
  5198 (ML: ProofGeneral.print_intros())
  5199 
  5200 * Pure: New flag trace_unify_fail causes unification to print
  5201 diagnostic information (PG: in trace buffer) when it fails. This is
  5202 useful for figuring out why single step proofs like rule, erule or
  5203 assumption failed.
  5204 
  5205 * Pure: Locale specifications now produce predicate definitions
  5206 according to the body of text (covering assumptions modulo local
  5207 definitions); predicate "loc_axioms" covers newly introduced text,
  5208 while "loc" is cumulative wrt. all included locale expressions; the
  5209 latter view is presented only on export into the global theory
  5210 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5211 on the old view without predicates;
  5212 
  5213 * Pure: predefined locales "var" and "struct" are useful for sharing
  5214 parameters (as in CASL, for example); just specify something like
  5215 ``var x + var y + struct M'' as import;
  5216 
  5217 * Pure: improved thms_containing: proper indexing of facts instead of
  5218 raw theorems; check validity of results wrt. current name space;
  5219 include local facts of proof configuration (also covers active
  5220 locales), cover fixed variables in index; may use "_" in term
  5221 specification; an optional limit for the number of printed facts may
  5222 be given (the default is 40);
  5223 
  5224 * Pure: disallow duplicate fact bindings within new-style theory files
  5225 (batch-mode only);
  5226 
  5227 * Provers: improved induct method: assumptions introduced by case
  5228 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5229 the goal statement); "foo" still refers to all facts collectively;
  5230 
  5231 * Provers: the function blast.overloaded has been removed: all constants
  5232 are regarded as potentially overloaded, which improves robustness in exchange
  5233 for slight decrease in efficiency;
  5234 
  5235 * Provers/linorder: New generic prover for transitivity reasoning over
  5236 linear orders.  Note: this prover is not efficient!
  5237 
  5238 * Isar: preview of problems to finish 'show' now produce an error
  5239 rather than just a warning (in interactive mode);
  5240 
  5241 
  5242 *** HOL ***
  5243 
  5244 * arith(_tac)
  5245 
  5246  - Produces a counter example if it cannot prove a goal.
  5247    Note that the counter example may be spurious if the goal is not a formula
  5248    of quantifier-free linear arithmetic.
  5249    In ProofGeneral the counter example appears in the trace buffer.
  5250 
  5251  - Knows about div k and mod k where k is a numeral of type nat or int.
  5252 
  5253  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5254    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5255    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5256 
  5257 * simp's arithmetic capabilities have been enhanced a bit: it now
  5258 takes ~= in premises into account (by performing a case split);
  5259 
  5260 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5261 are distributed over a sum of terms;
  5262 
  5263 * New tactic "trans_tac" and method "trans" instantiate
  5264 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5265 "<=", "<" and "=").
  5266 
  5267 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5268 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5269 
  5270 * 'typedef' command has new option "open" to suppress the set
  5271 definition;
  5272 
  5273 * functions Min and Max on finite sets have been introduced (theory
  5274 Finite_Set);
  5275 
  5276 * attribute [symmetric] now works for relations as well; it turns
  5277 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5278 
  5279 * induct over a !!-quantified statement (say !!x1..xn):
  5280   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5281 
  5282 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5283 %x. None. Warning: empty_def now refers to the previously hidden definition
  5284 of the empty set.
  5285 
  5286 * Algebra: formalization of classical algebra.  Intended as base for
  5287 any algebraic development in Isabelle.  Currently covers group theory
  5288 (up to Sylow's theorem) and ring theory (Universal Property of
  5289 Univariate Polynomials).  Contributions welcome;
  5290 
  5291 * GroupTheory: deleted, since its material has been moved to Algebra;
  5292 
  5293 * Complex: new directory of the complex numbers with numeric constants,
  5294 nonstandard complex numbers, and some complex analysis, standard and
  5295 nonstandard (Jacques Fleuriot);
  5296 
  5297 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5298 
  5299 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5300 Fleuriot);
  5301 
  5302 * Real/HahnBanach: updated and adapted to locales;
  5303 
  5304 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5305 Gray and Kramer);
  5306 
  5307 * UNITY: added the Meier-Sanders theory of progress sets;
  5308 
  5309 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5310 as abstract algorithms, instantiated to the JVM;
  5311 
  5312 * Bali: Java source language formalization. Type system, operational
  5313 semantics, axiomatic semantics. Supported language features:
  5314 classes, interfaces, objects,virtual methods, static methods,
  5315 static/instance fields, arrays, access modifiers, definite
  5316 assignment, exceptions.
  5317 
  5318 
  5319 *** ZF ***
  5320 
  5321 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5322 universe, etc.);
  5323 
  5324 * Main ZF: virtually all theories converted to new-style format;
  5325 
  5326 
  5327 *** ML ***
  5328 
  5329 * Pure: Tactic.prove provides sane interface for internal proofs;
  5330 omits the infamous "standard" operation, so this is more appropriate
  5331 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5332 
  5333 * Pure: improved error reporting of simprocs;
  5334 
  5335 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5336 up simprocs;
  5337 
  5338 
  5339 *** Document preparation ***
  5340 
  5341 * uses \par instead of \\ for line breaks in theory text. This may
  5342 shift some page breaks in large documents. To get the old behaviour
  5343 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5344 
  5345 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5346 other packages
  5347 
  5348 * \<euro> now needs package babel/greek instead of marvosym (which
  5349 broke \Rightarrow)
  5350 
  5351 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5352 textcomp package)
  5353 
  5354 
  5355 
  5356 New in Isabelle2002 (March 2002)
  5357 --------------------------------
  5358 
  5359 *** Document preparation ***
  5360 
  5361 * greatly simplified document preparation setup, including more
  5362 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5363 instructive isatool mkdir; users should basically be able to get
  5364 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5365 users may run a separate document processing stage manually like this:
  5366 "isatool usedir -D output HOL Test && isatool document Test/output";
  5367 
  5368 * theory dependency graph may now be incorporated into documents;
  5369 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5370 with \includegraphics of LaTeX;
  5371 
  5372 * proper spacing of consecutive markup elements, especially text
  5373 blocks after section headings;
  5374 
  5375 * support bold style (for single symbols only), input syntax is like
  5376 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5377 
  5378 * \<bullet> is now output as bold \cdot by default, which looks much
  5379 better in printed text;
  5380 
  5381 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5382 note that these symbols are currently unavailable in Proof General /
  5383 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5384 
  5385 * isatool latex no longer depends on changed TEXINPUTS, instead
  5386 isatool document copies the Isabelle style files to the target
  5387 location;
  5388 
  5389 
  5390 *** Isar ***
  5391 
  5392 * Pure/Provers: improved proof by cases and induction;
  5393   - 'case' command admits impromptu naming of parameters (such as
  5394     "case (Suc n)");
  5395   - 'induct' method divinates rule instantiation from the inductive
  5396     claim; no longer requires excessive ?P bindings for proper
  5397     instantiation of cases;
  5398   - 'induct' method properly enumerates all possibilities of set/type
  5399     rules; as a consequence facts may be also passed through *type*
  5400     rules without further ado;
  5401   - 'induct' method now derives symbolic cases from the *rulified*
  5402     rule (before it used to rulify cases stemming from the internal
  5403     atomized version); this means that the context of a non-atomic
  5404     statement becomes is included in the hypothesis, avoiding the
  5405     slightly cumbersome show "PROP ?case" form;
  5406   - 'induct' may now use elim-style induction rules without chaining
  5407     facts, using ``missing'' premises from the goal state; this allows
  5408     rules stemming from inductive sets to be applied in unstructured
  5409     scripts, while still benefitting from proper handling of non-atomic
  5410     statements; NB: major inductive premises need to be put first, all
  5411     the rest of the goal is passed through the induction;
  5412   - 'induct' proper support for mutual induction involving non-atomic
  5413     rule statements (uses the new concept of simultaneous goals, see
  5414     below);
  5415   - append all possible rule selections, but only use the first
  5416     success (no backtracking);
  5417   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5418   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5419   - added 'print_induct_rules' (covered by help item in recent Proof
  5420     General versions);
  5421   - moved induct/cases attributes to Pure, methods to Provers;
  5422   - generic method setup instantiated for FOL and HOL;
  5423 
  5424 * Pure: support multiple simultaneous goal statements, for example
  5425 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5426 meta-level mechanism, this acts as if several individual goals had
  5427 been stated separately; in particular common proof methods need to be
  5428 repeated in order to cover all claims; note that a single elimination
  5429 step is *not* sufficient to establish the two conjunctions, so this
  5430 fails:
  5431 
  5432   assume "A & B" then have A and B ..   (*".." fails*)
  5433 
  5434 better use "obtain" in situations as above; alternative refer to
  5435 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5436 
  5437 * Pure: proper integration with ``locales''; unlike the original
  5438 version by Florian Kammller, Isar locales package high-level proof
  5439 contexts rather than raw logical ones (e.g. we admit to include
  5440 attributes everywhere); operations on locales include merge and
  5441 rename; support for implicit arguments (``structures''); simultaneous
  5442 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5443 some examples;
  5444 
  5445 * Pure: the following commands have been ``localized'', supporting a
  5446 target locale specification "(in name)": 'lemma', 'theorem',
  5447 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5448 stored both within the locale and at the theory level (exported and
  5449 qualified by the locale name);
  5450 
  5451 * Pure: theory goals may now be specified in ``long'' form, with
  5452 ad-hoc contexts consisting of arbitrary locale elements. for example
  5453 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5454 definitions may be given, too); the result is a meta-level rule with
  5455 the context elements being discharged in the obvious way;
  5456 
  5457 * Pure: new proof command 'using' allows to augment currently used
  5458 facts after a goal statement ('using' is syntactically analogous to
  5459 'apply', but acts on the goal's facts only); this allows chained facts
  5460 to be separated into parts given before and after a claim, as in
  5461 ``from a and b have C using d and e <proof>'';
  5462 
  5463 * Pure: renamed "antecedent" case to "rule_context";
  5464 
  5465 * Pure: new 'judgment' command records explicit information about the
  5466 object-logic embedding (used by several tools internally); no longer
  5467 use hard-wired "Trueprop";
  5468 
  5469 * Pure: added 'corollary' command;
  5470 
  5471 * Pure: fixed 'token_translation' command;
  5472 
  5473 * Pure: removed obsolete 'exported' attribute;
  5474 
  5475 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5476 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5477 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5478 
  5479 * Pure: method 'atomize' presents local goal premises as object-level
  5480 statements (atomic meta-level propositions); setup controlled via
  5481 rewrite rules declarations of 'atomize' attribute; example
  5482 application: 'induct' method with proper rule statements in improper
  5483 proof *scripts*;
  5484 
  5485 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5486 now consider the syntactic context of assumptions, giving a better
  5487 chance to get type-inference of the arguments right (this is
  5488 especially important for locales);
  5489 
  5490 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5491 mode;
  5492 
  5493 * Pure/obtain: the formal conclusion "thesis", being marked as
  5494 ``internal'', may no longer be reference directly in the text;
  5495 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5496 situations;
  5497 
  5498 * Pure: generic 'sym' attribute which declares a rule both as pure
  5499 'elim?' and for the 'symmetric' operation;
  5500 
  5501 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5502 text; the fixed correlation with particular command syntax has been
  5503 discontinued;
  5504 
  5505 * Pure: new method 'rules' is particularly well-suited for proof
  5506 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5507 but often produces more compact proof terms with less detours;
  5508 
  5509 * Pure/Provers/classical: simplified integration with pure rule
  5510 attributes and methods; the classical "intro?/elim?/dest?"
  5511 declarations coincide with the pure ones; the "rule" method no longer
  5512 includes classically swapped intros; "intro" and "elim" methods no
  5513 longer pick rules from the context; also got rid of ML declarations
  5514 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5515 INCOMPATIBILITY;
  5516 
  5517 * Provers/classical: attribute 'swapped' produces classical inversions
  5518 of introduction rules;
  5519 
  5520 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5521 rules instead of full simplifier context; 'iff' attribute handles
  5522 conditional rules;
  5523 
  5524 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5525 
  5526 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5527 "(permissive)" option to recover old behavior;
  5528 
  5529 * HOL: 'inductive' no longer features separate (collective) attributes
  5530 for 'intros' (was found too confusing);
  5531 
  5532 * HOL: properly declared induction rules less_induct and
  5533 wf_induct_rule;
  5534 
  5535 
  5536 *** HOL ***
  5537 
  5538 * HOL: moved over to sane numeral syntax; the new policy is as
  5539 follows:
  5540 
  5541   - 0 and 1 are polymorphic constants, which are defined on any
  5542   numeric type (nat, int, real etc.);
  5543 
  5544   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5545   binary representation internally;
  5546 
  5547   - type nat has special constructor Suc, and generally prefers Suc 0
  5548   over 1::nat and Suc (Suc 0) over 2::nat;
  5549 
  5550 This change may cause significant problems of INCOMPATIBILITY; here
  5551 are some hints on converting existing sources:
  5552 
  5553   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5554   entities, so expressions involving "-" (unary or binary minus) need
  5555   to be spaced properly;
  5556 
  5557   - existing occurrences of "1" may need to be constraint "1::nat" or
  5558   even replaced by Suc 0; similar for old "2";
  5559 
  5560   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5561 
  5562   - remove all special provisions on numerals in proofs;
  5563 
  5564 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5565 representation (depends on bin_arith_simps in the default context);
  5566 
  5567 * HOL: symbolic syntax for x^2 (numeral 2);
  5568 
  5569 * HOL: the class of all HOL types is now called "type" rather than
  5570 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5571 in axclass/classes, instance/arities, and (usually rare) occurrences
  5572 in typings (of consts etc.); internally the class is called
  5573 "HOL.type", ML programs should refer to HOLogic.typeS;
  5574 
  5575 * HOL/record package improvements:
  5576   - new derived operations "fields" to build a partial record section,
  5577     "extend" to promote a fixed record to a record scheme, and
  5578     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5579     declared as simp by default;
  5580   - shared operations ("more", "fields", etc.) now need to be always
  5581     qualified) --- potential INCOMPATIBILITY;
  5582   - removed "make_scheme" operations (use "make" with "extend") --
  5583     INCOMPATIBILITY;
  5584   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5585   - provides cases/induct rules for use with corresponding Isar
  5586     methods (for concrete records, record schemes, concrete more
  5587     parts, and schematic more parts -- in that order);
  5588   - internal definitions directly based on a light-weight abstract
  5589     theory of product types over typedef rather than datatype;
  5590 
  5591 * HOL: generic code generator for generating executable ML code from
  5592 specifications; specific support for HOL constructs such as inductive
  5593 datatypes and sets, as well as recursive functions; can be invoked
  5594 via 'generate_code' theory section;
  5595 
  5596 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5597 
  5598 * HOL: consolidated and renamed several theories.  In particular:
  5599         Ord.thy has been absorbed into HOL.thy
  5600         String.thy has been absorbed into List.thy
  5601 
  5602 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5603 (beware of argument permutation!);
  5604 
  5605 * HOL: linorder_less_split superseded by linorder_cases;
  5606 
  5607 * HOL/List: "nodups" renamed to "distinct";
  5608 
  5609 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5610 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5611   - Ex_def has changed, now need to use some_eq_ex
  5612 
  5613 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5614 in this (rare) case use:
  5615 
  5616   delSWrapper "split_all_tac"
  5617   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5618 
  5619 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5620 MAY FAIL;
  5621 
  5622 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5623 Isabelle's type classes, ^ on functions and relations has too general
  5624 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5625 necessary to attach explicit type constraints;
  5626 
  5627 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5628 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5629 renamed accordingly (eg "compI" -> "rel_compI").
  5630 
  5631 * HOL: syntax translations now work properly with numerals and records
  5632 expressions;
  5633 
  5634 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5635 of "lam" -- INCOMPATIBILITY;
  5636 
  5637 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5638 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5639 renamed "Product_Type.unit";
  5640 
  5641 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5642 
  5643 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5644 the "cases" method);
  5645 
  5646 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5647 Florian Kammller);
  5648 
  5649 * HOL/IMP: updated and converted to new-style theory format; several
  5650 parts turned into readable document, with proper Isar proof texts and
  5651 some explanations (by Gerwin Klein);
  5652 
  5653 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5654 
  5655 * HOL-Hyperreal is now a logic image;
  5656 
  5657 
  5658 *** HOLCF ***
  5659 
  5660 * Isar: consts/constdefs supports mixfix syntax for continuous
  5661 operations;
  5662 
  5663 * Isar: domain package adapted to new-style theory format, e.g. see
  5664 HOLCF/ex/Dnat.thy;
  5665 
  5666 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5667 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5668 lift.induct_tac, always use UU instead of Undef;
  5669 
  5670 * HOLCF/IMP: updated and converted to new-style theory;
  5671 
  5672 
  5673 *** ZF ***
  5674 
  5675 * Isar: proper integration of logic-specific tools and packages,
  5676 including theory commands '(co)inductive', '(co)datatype',
  5677 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5678 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5679 
  5680 * theory Main no longer includes AC; for the Axiom of Choice, base
  5681 your theory on Main_ZFC;
  5682 
  5683 * the integer library now covers quotients and remainders, with many
  5684 laws relating division to addition, multiplication, etc.;
  5685 
  5686 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5687 typeless version of the formalism;
  5688 
  5689 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5690 format;
  5691 
  5692 * ZF/Induct: new directory for examples of inductive definitions,
  5693 including theory Multiset for multiset orderings; converted to
  5694 new-style theory format;
  5695 
  5696 * ZF: many new theorems about lists, ordinals, etc.;
  5697 
  5698 
  5699 *** General ***
  5700 
  5701 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5702 variable proof controls level of detail: 0 = no proofs (only oracle
  5703 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5704 also ref manual for further ML interfaces;
  5705 
  5706 * Pure/axclass: removed obsolete ML interface
  5707 goal_subclass/goal_arity;
  5708 
  5709 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5710 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5711 separate tokens, so expressions involving minus need to be spaced
  5712 properly;
  5713 
  5714 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5715 rather than "infixl" or "infixr";
  5716 
  5717 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5718 sort constraint specifications in type inference; e.g. "x::_::foo"
  5719 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5720 type variable);
  5721 
  5722 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5723 control output of nested => (types); the default behavior is
  5724 "type_brackets";
  5725 
  5726 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5727 tokens into AST constants;
  5728 
  5729 * Pure/syntax: prefer later declarations of translations and print
  5730 translation functions; potential INCOMPATIBILITY: need to reverse
  5731 multiple declarations for same syntax element constant;
  5732 
  5733 * Pure/show_hyps reset by default (in accordance to existing Isar
  5734 practice);
  5735 
  5736 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5737 addSafter;
  5738 
  5739 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5740 as well;
  5741 
  5742 * system: tested support for MacOS X; should be able to get Isabelle +
  5743 Proof General to work in a plain Terminal after installing Poly/ML
  5744 (e.g. from the Isabelle distribution area) and GNU bash alone
  5745 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5746 support requires further installations, e.g. from
  5747 http://fink.sourceforge.net/);
  5748 
  5749 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5750 
  5751 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5752 of 40 MB), cf. ML_OPTIONS;
  5753 
  5754 * system: Proof General keywords specification is now part of the
  5755 Isabelle distribution (see etc/isar-keywords.el);
  5756 
  5757 * system: support for persistent Proof General sessions (refrain from
  5758 outdating all loaded theories on startup); user may create writable
  5759 logic images like this: ``isabelle -q HOL Test'';
  5760 
  5761 * system: smart selection of Isabelle process versus Isabelle
  5762 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5763 run both "isabelle" and "Isabelle" even if file names are badly
  5764 damaged (executable inspects the case of the first letter of its own
  5765 name); added separate "isabelle-process" and "isabelle-interface";
  5766 
  5767 * system: refrain from any attempt at filtering input streams; no
  5768 longer support ``8bit'' encoding of old isabelle font, instead proper
  5769 iso-latin characters may now be used; the related isatools
  5770 "symbolinput" and "nonascii" have disappeared as well;
  5771 
  5772 * system: removed old "xterm" interface (the print modes "xterm" and
  5773 "xterm_color" are still available for direct use in a suitable
  5774 terminal);
  5775 
  5776 
  5777 
  5778 New in Isabelle99-2 (February 2001)
  5779 -----------------------------------
  5780 
  5781 *** Overview of INCOMPATIBILITIES ***
  5782 
  5783 * HOL: please note that theories in the Library and elsewhere often use the
  5784 new-style (Isar) format; to refer to their theorems in an ML script you must
  5785 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5786 
  5787 * HOL: inductive package no longer splits induction rule aggressively,
  5788 but only as far as specified by the introductions given; the old
  5789 format may be recovered via ML function complete_split_rule or attribute
  5790 'split_rule (complete)';
  5791 
  5792 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5793 gfp_Tarski to gfp_unfold;
  5794 
  5795 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5796 
  5797 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5798 relation); infix "^^" has been renamed "``"; infix "``" has been
  5799 renamed "`"; "univalent" has been renamed "single_valued";
  5800 
  5801 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5802 operation;
  5803 
  5804 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5805 
  5806 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5807 
  5808 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5809 consequence, it is no longer monotonic wrt. the local goal context
  5810 (which is now passed through the inductive cases);
  5811 
  5812 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5813 \<gg> to \<ggreater>;
  5814 
  5815 
  5816 *** Document preparation ***
  5817 
  5818 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5819 available: are "it" for near math-mode best-style output, "sl" for
  5820 slanted text style, and "tt" for plain type-writer; if no
  5821 \isabellestyle command is given, output is according to slanted
  5822 type-writer);
  5823 
  5824 * support sub/super scripts (for single symbols only), input syntax is
  5825 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5826 
  5827 * some more standard symbols; see Appendix A of the system manual for
  5828 the complete list of symbols defined in isabellesym.sty;
  5829 
  5830 * improved isabelle style files; more abstract symbol implementation
  5831 (should now use \isamath{...} and \isatext{...} in custom symbol
  5832 definitions);
  5833 
  5834 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5835 state; Note that presentation of goal states does not conform to
  5836 actual human-readable proof documents.  Please do not include goal
  5837 states into document output unless you really know what you are doing!
  5838 
  5839 * proper indentation of antiquoted output with proportional LaTeX
  5840 fonts;
  5841 
  5842 * no_document ML operator temporarily disables LaTeX document
  5843 generation;
  5844 
  5845 * isatool unsymbolize tunes sources for plain ASCII communication;
  5846 
  5847 
  5848 *** Isar ***
  5849 
  5850 * Pure: Isar now suffers initial goal statements to contain unbound
  5851 schematic variables (this does not conform to actual readable proof
  5852 documents, due to unpredictable outcome and non-compositional proof
  5853 checking); users who know what they are doing may use schematic goals
  5854 for Prolog-style synthesis of proven results;
  5855 
  5856 * Pure: assumption method (an implicit finishing) now handles actual
  5857 rules as well;
  5858 
  5859 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5860 initial goal, declare "that" only as Pure intro (only for single
  5861 steps); the "that" rule assumption may now be involved in implicit
  5862 finishing, thus ".." becomes a feasible for trivial obtains;
  5863 
  5864 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5865 instance proofs may be performed by "..";
  5866 
  5867 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5868 statements as well;
  5869 
  5870 * Pure: more robust selection of calculational rules;
  5871 
  5872 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5873 rule (as well as the assumption rule);
  5874 
  5875 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5876 lemmas, using the graph browser tool;
  5877 
  5878 * Pure: predict failure of "show" in interactive mode;
  5879 
  5880 * Pure: 'thms_containing' now takes actual terms as arguments;
  5881 
  5882 * HOL: improved method 'induct' --- now handles non-atomic goals
  5883 (potential INCOMPATIBILITY); tuned error handling;
  5884 
  5885 * HOL: cases and induct rules now provide explicit hints about the
  5886 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5887 any remaining facts are inserted into the goal verbatim;
  5888 
  5889 * HOL: local contexts (aka cases) may now contain term bindings as
  5890 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5891 the result to be shown in each case;
  5892 
  5893 * HOL: added 'recdef_tc' command;
  5894 
  5895 * isatool convert assists in eliminating legacy ML scripts;
  5896 
  5897 
  5898 *** HOL ***
  5899 
  5900 * HOL/Library: a collection of generic theories to be used together
  5901 with main HOL; the theory loader path already includes this directory
  5902 by default; the following existing theories have been moved here:
  5903 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5904 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5905 
  5906 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5907 modelling and verification task performed in Isabelle/HOL +
  5908 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5909 
  5910 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5911 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5912 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5913 'domain', this makes the theory consistent with mathematical
  5914 literature;
  5915 
  5916 * HOL basics: added overloaded operations "inverse" and "divide"
  5917 (infix "/"), syntax for generic "abs" operation, generic summation
  5918 operator \<Sum>;
  5919 
  5920 * HOL/typedef: simplified package, provide more useful rules (see also
  5921 HOL/subset.thy);
  5922 
  5923 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5924 now expressed as a proper nested rule (old-style tactic scripts may
  5925 require atomize_strip_tac to cope with non-atomic premises);
  5926 
  5927 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5928 to "split_conv" (old name still available for compatibility);
  5929 
  5930 * HOL: improved concrete syntax for strings (e.g. allows translation
  5931 rules with string literals);
  5932 
  5933 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5934  and Fleuriot's mechanization of analysis, including the transcendental
  5935  functions for the reals;
  5936 
  5937 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5938 
  5939 
  5940 *** CTT ***
  5941 
  5942 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5943 "lam" is displayed as TWO lambda-symbols
  5944 
  5945 * CTT: theory Main now available, containing everything (that is, Bool
  5946 and Arith);
  5947 
  5948 
  5949 *** General ***
  5950 
  5951 * Pure: the Simplifier has been implemented properly as a derived rule
  5952 outside of the actual kernel (at last!); the overall performance
  5953 penalty in practical applications is about 50%, while reliability of
  5954 the Isabelle inference kernel has been greatly improved;
  5955 
  5956 * print modes "brackets" and "no_brackets" control output of nested =>
  5957 (types) and ==> (props); the default behaviour is "brackets";
  5958 
  5959 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5960 as assumptions as well;
  5961 
  5962 * system: support Poly/ML 4.0;
  5963 
  5964 * system: isatool install handles KDE version 1 or 2;
  5965 
  5966 
  5967 
  5968 New in Isabelle99-1 (October 2000)
  5969 ----------------------------------
  5970 
  5971 *** Overview of INCOMPATIBILITIES ***
  5972 
  5973 * HOL: simplification of natural numbers is much changed; to partly
  5974 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5975 issue the following ML commands:
  5976 
  5977   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5978   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5979 
  5980 * HOL: simplification no longer dives into case-expressions; this is
  5981 controlled by "t.weak_case_cong" for each datatype t;
  5982 
  5983 * HOL: nat_less_induct renamed to less_induct;
  5984 
  5985 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5986 fixsome to patch .thy and .ML sources automatically;
  5987 
  5988   select_equality  -> some_equality
  5989   select_eq_Ex     -> some_eq_ex
  5990   selectI2EX       -> someI2_ex
  5991   selectI2         -> someI2
  5992   selectI          -> someI
  5993   select1_equality -> some1_equality
  5994   Eps_sym_eq       -> some_sym_eq_trivial
  5995   Eps_eq           -> some_eq_trivial
  5996 
  5997 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5998 
  5999 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6000 instead);
  6001 
  6002 * HOL: the recursion equations generated by 'recdef' are now called
  6003 f.simps instead of f.rules;
  6004 
  6005 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6006 
  6007 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6008 sometimes be needed;
  6009 
  6010 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6011 
  6012 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6013 
  6014 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6015 product is now "<*>" instead of "Times"; the lexicographic product is
  6016 now "<*lex*>" instead of "**";
  6017 
  6018 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6019 of main HOL, but was unused); better use HOL's datatype package;
  6020 
  6021 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6022 the old syntax may be recovered as follows:
  6023 
  6024   syntax (symbols)
  6025     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6026       (infixl "\\<oplus>" 100)
  6027 
  6028 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6029 
  6030 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6031 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6032 internally;
  6033 
  6034 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6035 changed from A/r to A//r;
  6036 
  6037 * ZF: new treatment of arithmetic (nat & int) may break some old
  6038 proofs;
  6039 
  6040 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6041 rulify -> rule_format, elimify -> elim_format, ...);
  6042 
  6043 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6044 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6045 should have to change intro!! to intro? only); replaced "delrule" by
  6046 "rule del";
  6047 
  6048 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6049 
  6050 * Provers: strengthened force_tac by using new first_best_tac;
  6051 
  6052 * LaTeX document preparation: several changes of isabelle.sty (see
  6053 lib/texinputs);
  6054 
  6055 
  6056 *** Document preparation ***
  6057 
  6058 * formal comments (text blocks etc.) in new-style theories may now
  6059 contain antiquotations of thm/prop/term/typ/text to be presented
  6060 according to latex print mode; concrete syntax is like this:
  6061 @{term[show_types] "f(x) = a + x"};
  6062 
  6063 * isatool mkdir provides easy setup of Isabelle session directories,
  6064 including proper document sources;
  6065 
  6066 * generated LaTeX sources are now deleted after successful run
  6067 (isatool document -c); may retain a copy somewhere else via -D option
  6068 of isatool usedir;
  6069 
  6070 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6071 style files, achieving self-contained LaTeX sources and simplifying
  6072 LaTeX debugging;
  6073 
  6074 * old-style theories now produce (crude) LaTeX output as well;
  6075 
  6076 * browser info session directories are now self-contained (may be put
  6077 on WWW server seperately); improved graphs of nested sessions; removed
  6078 graph for 'all sessions';
  6079 
  6080 * several improvements in isabelle style files; \isabellestyle{it}
  6081 produces fake math mode output; \isamarkupheader is now \section by
  6082 default; see lib/texinputs/isabelle.sty etc.;
  6083 
  6084 
  6085 *** Isar ***
  6086 
  6087 * Isar/Pure: local results and corresponding term bindings are now
  6088 subject to Hindley-Milner polymorphism (similar to ML); this
  6089 accommodates incremental type-inference very nicely;
  6090 
  6091 * Isar/Pure: new derived language element 'obtain' supports
  6092 generalized existence reasoning;
  6093 
  6094 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6095 support accumulation of results, without applying any rules yet;
  6096 useful to collect intermediate results without explicit name
  6097 references, and for use with transitivity rules with more than 2
  6098 premises;
  6099 
  6100 * Isar/Pure: scalable support for case-analysis type proofs: new
  6101 'case' language element refers to local contexts symbolically, as
  6102 produced by certain proof methods; internally, case names are attached
  6103 to theorems as "tags";
  6104 
  6105 * Isar/Pure: theory command 'hide' removes declarations from
  6106 class/type/const name spaces;
  6107 
  6108 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6109 indicate potential overloading;
  6110 
  6111 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6112 
  6113 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6114 "{a,b,c}" instead of {a,b,c};
  6115 
  6116 * Isar/Pure now provides its own version of intro/elim/dest
  6117 attributes; useful for building new logics, but beware of confusion
  6118 with the version in Provers/classical;
  6119 
  6120 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6121 case name 'antecedent';
  6122 
  6123 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6124 to the current context is now done automatically);
  6125 
  6126 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6127 for definining proof methods in ML;
  6128 
  6129 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6130 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6131 most cases, one should have to change intro!! to intro? only);
  6132 replaced "delrule" by "rule del";
  6133 
  6134 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6135 'symmetric' attribute (the latter supercedes [RS sym]);
  6136 
  6137 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6138 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6139 well (including splits);
  6140 
  6141 * Isar/Provers: Simplifier and Classical methods now support all kind
  6142 of modifiers used in the past, including 'cong', 'iff', etc.
  6143 
  6144 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6145 of Simplifier and Classical reasoner);
  6146 
  6147 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6148 now support named cases; major packages (inductive, datatype, primrec,
  6149 recdef) support case names and properly name parameters;
  6150 
  6151 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6152 monotonicity conditions are extracted to be proven at end of
  6153 calculations;
  6154 
  6155 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6156 method anyway;
  6157 
  6158 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6159 split_if split_if_asm; datatype package provides theorems foo.splits =
  6160 foo.split foo.split_asm for each datatype;
  6161 
  6162 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6163 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6164 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6165 use "(cases (simplified))" method in proper proof texts);
  6166 
  6167 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6168 
  6169 * Isar: names of theorems etc. may be natural numbers as well;
  6170 
  6171 * Isar: 'pr' command: optional arguments for goals_limit and
  6172 ProofContext.prems_limit; no longer prints theory contexts, but only
  6173 proof states;
  6174 
  6175 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6176 additional print modes to be specified; e.g. "pr(latex)" will print
  6177 proof state according to the Isabelle LaTeX style;
  6178 
  6179 * Isar: improved support for emulating tactic scripts, including proof
  6180 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6181 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6182 (for HOL datatypes);
  6183 
  6184 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6185 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6186 'proof method scripts' have to be in depth-first order;
  6187 
  6188 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6189 
  6190 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6191 should instead use individual commands for printing items
  6192 (print_commands, print_methods etc.);
  6193 
  6194 * Isar: added 'nothing' --- the empty list of theorems;
  6195 
  6196 
  6197 *** HOL ***
  6198 
  6199 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6200 corresponding virtual machine and a specification of its bytecode
  6201 verifier and a lightweight bytecode verifier, including proofs of
  6202 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6203 Cornelia Pusch (see also the homepage of project Bali at
  6204 http://isabelle.in.tum.de/Bali/);
  6205 
  6206 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6207 Clemens Ballarin;
  6208 
  6209 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6210 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6211 Rasmussen;
  6212 
  6213 * HOL/Lattice: fundamental concepts of lattice theory and order
  6214 structures, including duals, properties of bounds versus algebraic
  6215 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6216 Theorem for complete lattices etc.; may also serve as a demonstration
  6217 for abstract algebraic reasoning using axiomatic type classes, and
  6218 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6219 
  6220 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6221 von Oheimb;
  6222 
  6223 * HOL/IMPP: extension of IMP with local variables and mutually
  6224 recursive procedures, by David von Oheimb;
  6225 
  6226 * HOL/Lambda: converted into new-style theory and document;
  6227 
  6228 * HOL/ex/Multiquote: example of multiple nested quotations and
  6229 anti-quotations -- basically a generalized version of de-Bruijn
  6230 representation; very useful in avoiding lifting of operations;
  6231 
  6232 * HOL/record: added general record equality rule to simpset; fixed
  6233 select-update simplification procedure to handle extended records as
  6234 well; admit "r" as field name;
  6235 
  6236 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with