NEWS
author haftmann
Sat Aug 28 11:42:33 2010 +0200 (2010-08-28)
changeset 38858 1920158cfa17
parent 38830 51efa72555bb
parent 38857 97775f3e8722
child 38864 4abe644fcea5
permissions -rw-r--r--
merged
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    10 a Unicode character is treated as a single symbol, not a sequence of
    11 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    12 contain symbols without further backslash escapes, Unicode can now be
    13 used here as well.  Recall that Symbol.explode in ML provides a
    14 consistent view on symbols, while raw explode (or String.explode)
    15 merely give a byte-oriented representation.
    16 
    17 * Theory loading: only the master source file is looked-up in the
    18 implicit load path, all other files are addressed relatively to its
    19 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    20 
    21 * Special treatment of ML file names has been discontinued.
    22 Historically, optional extensions .ML or .sml were added on demand --
    23 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    24 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    25 
    26 * Various options that affect document antiquotations are now properly
    27 handled within the context via configuration options, instead of
    28 unsynchronized references.  There are both ML Config.T entities and
    29 Isar declaration attributes to access these.
    30 
    31   ML:                       Isar:
    32 
    33   Thy_Output.display        thy_output_display
    34   Thy_Output.quotes         thy_output_quotes
    35   Thy_Output.indent         thy_output_indent
    36   Thy_Output.source         thy_output_source
    37   Thy_Output.break          thy_output_break
    38 
    39 Note that the corresponding "..._default" references may be only
    40 changed globally at the ROOT session setup, but *not* within a theory.
    41 
    42 * ML structure Unsynchronized never opened, not even in Isar
    43 interaction mode as before.  Old Unsynchronized.set etc. have been
    44 discontinued -- use plain := instead.  This should be *rare* anyway,
    45 since modern tools always work via official context data, notably
    46 configuration options.
    47 
    48 
    49 *** Pure ***
    50 
    51 * Interpretation command 'interpret' accepts a list of equations like
    52 'interpretation' does.
    53 
    54 * Diagnostic command 'print_interps' prints interpretations in proofs
    55 in addition to interpretations in theories.
    56 
    57 * Discontinued obsolete 'global' and 'local' commands to manipulate
    58 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    59 Sign.root_path and Sign.local_path may be applied directly where this
    60 feature is still required for historical reasons.
    61 
    62 
    63 *** HOL ***
    64 
    65 * Renamed class eq and constant eq (for code generation) to class equal
    66 and constant equal, plus renaming of related facts and various tuning.
    67 INCOMPATIBILITY.
    68 
    69 * Scala (2.8 or higher) has been added to the target languages of
    70 the code generator.
    71 
    72 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    73 
    74 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    75 canonical names for instance definitions for functions; various improvements.
    76 INCOMPATIBILITY.
    77 
    78 * Records: logical foundation type for records do not carry a '_type' suffix
    79 any longer.  INCOMPATIBILITY.
    80 
    81 * Code generation for records: more idiomatic representation of record types.
    82 Warning: records are not covered by ancient SML code generation any longer.
    83 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    84 helps to succeed then:
    85 
    86   record 'a foo = ...
    87   ...
    88   rep_datatype foo_ext ...
    89 
    90 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    91 INCOMPATIBILITY.
    92 
    93 * Quickcheck in locales considers interpretations of that locale for
    94 counter example search.
    95 
    96 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    97 in Library/State_Monad has been changed to avoid ambiguities.
    98 INCOMPATIBILITY.
    99 
   100 * Code generator: export_code without explicit file declaration prints
   101 to standard output.  INCOMPATIBILITY.
   102 
   103 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   104 respectively.  INCOMPATIBILITY.
   105 
   106 * Constant "split" has been merged with constant "prod_case";  names
   107 of ML functions, facts etc. involving split have been retained so far,
   108 though.  INCOMPATIBILITY.
   109 
   110 * Dropped old infix syntax "mem" for List.member;  use "in set"
   111 instead.  INCOMPATIBILITY.
   112 
   113 * Refactoring of code-generation specific operations in List.thy
   114 
   115   constants
   116     null ~> List.null
   117 
   118   facts
   119     mem_iff ~> member_def
   120     null_empty ~> null_def
   121 
   122 INCOMPATIBILITY.  Note that these were not suppossed to be used
   123 regularly unless for striking reasons;  their main purpose was code
   124 generation.
   125 
   126 * Some previously unqualified names have been qualified:
   127 
   128   types
   129     bool ~> HOL.bool
   130     nat ~> Nat.nat
   131 
   132   constants
   133     Trueprop ~> HOL.Trueprop
   134     True ~> HOL.True
   135     False ~> HOL.False
   136     op & ~> HOL.conj
   137     op | ~> HOL.disj
   138     op --> ~> HOL.implies
   139     Not ~> HOL.Not
   140     The ~> HOL.The
   141     All ~> HOL.All
   142     Ex ~> HOL.Ex
   143     Ex1 ~> HOL.Ex1
   144     Let ~> HOL.Let
   145     If ~> HOL.If
   146     Ball ~> Set.Ball
   147     Bex ~> Set.Bex
   148     Suc ~> Nat.Suc
   149     Pair ~> Product_Type.Pair
   150     fst ~> Product_Type.fst
   151     snd ~> Product_Type.snd
   152     curry ~> Product_Type.curry
   153     op : ~> Set.member
   154     Collect ~> Set.Collect
   155 
   156 INCOMPATIBILITY.
   157 
   158 * Removed simplifier congruence rule of "prod_case", as has for long
   159 been the case with "split".  INCOMPATIBILITY.
   160 
   161 * Datatype package: theorems generated for executable equality
   162 (class eq) carry proper names and are treated as default code
   163 equations.
   164 
   165 * List.thy: use various operations from the Haskell prelude when
   166 generating Haskell code.
   167 
   168 * code_simp.ML and method code_simp: simplification with rules determined
   169 by code generator.
   170 
   171 * code generator: do not print function definitions for case
   172 combinators any longer.
   173 
   174 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   175 theorems are now stated in terms of euclidean spaces instead of finite
   176 cartesian products.
   177 
   178   types
   179     real ^ 'n ~>  'a::real_vector
   180               ~>  'a::euclidean_space
   181               ~>  'a::ordered_euclidean_space
   182         (depends on your needs)
   183 
   184   constants
   185      _ $ _        ~> _ $$ _
   186      \<chi> x. _  ~> \<chi>\<chi> x. _
   187      CARD('n)     ~> DIM('a)
   188 
   189 Also note that the indices are now natural numbers and not from some finite
   190 type. Finite cartesian products of euclidean spaces, products of euclidean
   191 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   192 
   193 INCOMPATIBILITY.
   194 
   195 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   196 as value for measures. Introduces Lebesgue Measure based on the integral in
   197 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   198 spaces.
   199 
   200  INCOMPATIBILITY.
   201 
   202 * Inductive package: offers new command "inductive_simps" to automatically
   203 derive instantiated and simplified equations for inductive predicates,
   204 similar to inductive_cases.
   205 
   206 
   207 *** FOL ***
   208 
   209 * All constant names are now qualified.  INCOMPATIBILITY.
   210 
   211 
   212 *** ZF ***
   213 
   214 * All constant names are now qualified.  INCOMPATIBILITY.
   215 
   216 
   217 *** ML ***
   218 
   219 * ML antiquotations @{theory} and @{theory_ref} refer to named
   220 theories from the ancestry of the current context, not any accidental
   221 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   222 change in semantics.
   223 
   224 
   225 *** System ***
   226 
   227 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   228 
   229 
   230 
   231 New in Isabelle2009-2 (June 2010)
   232 ---------------------------------
   233 
   234 *** General ***
   235 
   236 * Authentic syntax for *all* logical entities (type classes, type
   237 constructors, term constants): provides simple and robust
   238 correspondence between formal entities and concrete syntax.  Within
   239 the parse tree / AST representations, "constants" are decorated by
   240 their category (class, type, const) and spelled out explicitly with
   241 their full internal name.
   242 
   243 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   244 and translations (translation rules and translation functions in ML).
   245 Some hints on upgrading:
   246 
   247   - Many existing uses of 'syntax' and 'translations' can be replaced
   248     by more modern 'type_notation', 'notation' and 'abbreviation',
   249     which are independent of this issue.
   250 
   251   - 'translations' require markup within the AST; the term syntax
   252     provides the following special forms:
   253 
   254       CONST c   -- produces syntax version of constant c from context
   255       XCONST c  -- literally c, checked as constant from context
   256       c         -- literally c, if declared by 'syntax'
   257 
   258     Plain identifiers are treated as AST variables -- occasionally the
   259     system indicates accidental variables via the error "rhs contains
   260     extra variables".
   261 
   262     Type classes and type constructors are marked according to their
   263     concrete syntax.  Some old translations rules need to be written
   264     for the "type" category, using type constructor application
   265     instead of pseudo-term application of the default category
   266     "logic".
   267 
   268   - 'parse_translation' etc. in ML may use the following
   269     antiquotations:
   270 
   271       @{class_syntax c}   -- type class c within parse tree / AST
   272       @{term_syntax c}    -- type constructor c within parse tree / AST
   273       @{const_syntax c}   -- ML version of "CONST c" above
   274       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   275 
   276   - Literal types within 'typed_print_translations', i.e. those *not*
   277     represented as pseudo-terms are represented verbatim.  Use @{class
   278     c} or @{type_name c} here instead of the above syntax
   279     antiquotations.
   280 
   281 Note that old non-authentic syntax was based on unqualified base
   282 names, so all of the above "constant" names would coincide.  Recall
   283 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   284 diagnose syntax problems.
   285 
   286 * Type constructors admit general mixfix syntax, not just infix.
   287 
   288 * Concrete syntax may be attached to local entities without a proof
   289 body, too.  This works via regular mixfix annotations for 'fix',
   290 'def', 'obtain' etc. or via the explicit 'write' command, which is
   291 similar to the 'notation' command in theory specifications.
   292 
   293 * Discontinued unnamed infix syntax (legacy feature for many years) --
   294 need to specify constant name and syntax separately.  Internal ML
   295 datatype constructors have been renamed from InfixName to Infix etc.
   296 Minor INCOMPATIBILITY.
   297 
   298 * Schematic theorem statements need to be explicitly markup as such,
   299 via commands 'schematic_lemma', 'schematic_theorem',
   300 'schematic_corollary'.  Thus the relevance of the proof is made
   301 syntactically clear, which impacts performance in a parallel or
   302 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   303 
   304 * Use of cumulative prems via "!" in some proof methods has been
   305 discontinued (old legacy feature).
   306 
   307 * References 'trace_simp' and 'debug_simp' have been replaced by
   308 configuration options stored in the context. Enabling tracing (the
   309 case of debugging is similar) in proofs works via
   310 
   311   using [[trace_simp = true]]
   312 
   313 Tracing is then active for all invocations of the simplifier in
   314 subsequent goal refinement steps. Tracing may also still be enabled or
   315 disabled via the ProofGeneral settings menu.
   316 
   317 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   318 'hide_fact' replace the former 'hide' KIND command.  Minor
   319 INCOMPATIBILITY.
   320 
   321 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   322 more efficient than combinations with -q1 or -q2.
   323 
   324 
   325 *** Pure ***
   326 
   327 * Proofterms record type-class reasoning explicitly, using the
   328 "unconstrain" operation internally.  This eliminates all sort
   329 constraints from a theorem and proof, introducing explicit
   330 OFCLASS-premises.  On the proof term level, this operation is
   331 automatically applied at theorem boundaries, such that closed proofs
   332 are always free of sort constraints.  INCOMPATIBILITY for tools that
   333 inspect proof terms.
   334 
   335 * Local theory specifications may depend on extra type variables that
   336 are not present in the result type -- arguments TYPE('a) :: 'a itself
   337 are added internally.  For example:
   338 
   339   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   340 
   341 * Predicates of locales introduced by classes carry a mandatory
   342 "class" prefix.  INCOMPATIBILITY.
   343 
   344 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   345 
   346 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   347 'class' instead.
   348 
   349 * Command 'code_reflect' allows to incorporate generated ML code into
   350 runtime environment; replaces immature code_datatype antiquotation.
   351 INCOMPATIBILITY.
   352 
   353 * Code generator: simple concept for abstract datatypes obeying
   354 invariants.
   355 
   356 * Code generator: details of internal data cache have no impact on the
   357 user space functionality any longer.
   358 
   359 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   360 subgoals.  This is more appropriate for interpretations with 'where'.
   361 INCOMPATIBILITY.
   362 
   363 * Command 'example_proof' opens an empty proof body.  This allows to
   364 experiment with Isar, without producing any persistent result.
   365 
   366 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   367 within a local theory context, with explicit checking of the
   368 constructors involved (in contrast to the raw 'syntax' versions).
   369 
   370 * Commands 'types' and 'typedecl' now work within a local theory
   371 context -- without introducing dependencies on parameters or
   372 assumptions, which is not possible in Isabelle/Pure.
   373 
   374 * Command 'defaultsort' has been renamed to 'default_sort', it works
   375 within a local theory context.  Minor INCOMPATIBILITY.
   376 
   377 
   378 *** HOL ***
   379 
   380 * Command 'typedef' now works within a local theory context -- without
   381 introducing dependencies on parameters or assumptions, which is not
   382 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   383 contain multiple interpretations of local typedefs (with different
   384 non-emptiness proofs), even in a global theory context.
   385 
   386 * New package for quotient types.  Commands 'quotient_type' and
   387 'quotient_definition' may be used for defining types and constants by
   388 quotient constructions.  An example is the type of integers created by
   389 quotienting pairs of natural numbers:
   390 
   391   fun
   392     intrel :: "(nat * nat) => (nat * nat) => bool"
   393   where
   394     "intrel (x, y) (u, v) = (x + v = u + y)"
   395 
   396   quotient_type int = "nat * nat" / intrel
   397     by (auto simp add: equivp_def expand_fun_eq)
   398 
   399   quotient_definition
   400     "0::int" is "(0::nat, 0::nat)"
   401 
   402 The method "lifting" can be used to lift of theorems from the
   403 underlying "raw" type to the quotient type.  The example
   404 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   405 construction and provides a reasoning infrastructure for finite sets.
   406 
   407 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   408 clash with new theory Quotient in Main HOL.
   409 
   410 * Moved the SMT binding into the main HOL session, eliminating
   411 separate HOL-SMT session.
   412 
   413 * List membership infix mem operation is only an input abbreviation.
   414 INCOMPATIBILITY.
   415 
   416 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   417 for future developements; former Library/Word.thy is still present in
   418 the AFP entry RSAPPS.
   419 
   420 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   421 longer shadowed.  INCOMPATIBILITY.
   422 
   423 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   424 INCOMPATIBILITY.
   425 
   426 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   427 INCOMPATIBILITY.
   428 
   429 * Dropped normalizing_semiring etc; use the facts in semiring classes
   430 instead.  INCOMPATIBILITY.
   431 
   432 * Dropped several real-specific versions of lemmas about floor and
   433 ceiling; use the generic lemmas from theory "Archimedean_Field"
   434 instead.  INCOMPATIBILITY.
   435 
   436   floor_number_of_eq         ~> floor_number_of
   437   le_floor_eq_number_of      ~> number_of_le_floor
   438   le_floor_eq_zero           ~> zero_le_floor
   439   le_floor_eq_one            ~> one_le_floor
   440   floor_less_eq_number_of    ~> floor_less_number_of
   441   floor_less_eq_zero         ~> floor_less_zero
   442   floor_less_eq_one          ~> floor_less_one
   443   less_floor_eq_number_of    ~> number_of_less_floor
   444   less_floor_eq_zero         ~> zero_less_floor
   445   less_floor_eq_one          ~> one_less_floor
   446   floor_le_eq_number_of      ~> floor_le_number_of
   447   floor_le_eq_zero           ~> floor_le_zero
   448   floor_le_eq_one            ~> floor_le_one
   449   floor_subtract_number_of   ~> floor_diff_number_of
   450   floor_subtract_one         ~> floor_diff_one
   451   ceiling_number_of_eq       ~> ceiling_number_of
   452   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   453   ceiling_le_zero_eq         ~> ceiling_le_zero
   454   ceiling_le_eq_one          ~> ceiling_le_one
   455   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   456   less_ceiling_eq_zero       ~> zero_less_ceiling
   457   less_ceiling_eq_one        ~> one_less_ceiling
   458   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   459   ceiling_less_eq_zero       ~> ceiling_less_zero
   460   ceiling_less_eq_one        ~> ceiling_less_one
   461   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   462   le_ceiling_eq_zero         ~> zero_le_ceiling
   463   le_ceiling_eq_one          ~> one_le_ceiling
   464   ceiling_subtract_number_of ~> ceiling_diff_number_of
   465   ceiling_subtract_one       ~> ceiling_diff_one
   466 
   467 * Theory "Finite_Set": various folding_XXX locales facilitate the
   468 application of the various fold combinators on finite sets.
   469 
   470 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   471 provides abstract red-black tree type which is backed by "RBT_Impl" as
   472 implementation.  INCOMPATIBILTY.
   473 
   474 * Theory Library/Coinductive_List has been removed -- superseded by
   475 AFP/thys/Coinductive.
   476 
   477 * Theory PReal, including the type "preal" and related operations, has
   478 been removed.  INCOMPATIBILITY.
   479 
   480 * Real: new development using Cauchy Sequences.
   481 
   482 * Split off theory "Big_Operators" containing setsum, setprod,
   483 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   484 
   485 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   486 "Int" etc.  INCOMPATIBILITY.
   487 
   488 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   489 
   490 * New set of rules "ac_simps" provides combined assoc / commute
   491 rewrites for all interpretations of the appropriate generic locales.
   492 
   493 * Renamed theory "OrderedGroup" to "Groups" and split theory
   494 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   495 appropriate and more consistent names suitable for name prefixes
   496 within the HOL theories.  INCOMPATIBILITY.
   497 
   498 * Some generic constants have been put to appropriate theories:
   499   - less_eq, less: Orderings
   500   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   501   - inverse, divide: Rings
   502 INCOMPATIBILITY.
   503 
   504 * More consistent naming of type classes involving orderings (and
   505 lattices):
   506 
   507     lower_semilattice                   ~> semilattice_inf
   508     upper_semilattice                   ~> semilattice_sup
   509 
   510     dense_linear_order                  ~> dense_linorder
   511 
   512     pordered_ab_group_add               ~> ordered_ab_group_add
   513     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   514     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   515     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   516     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   517     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   518     pordered_cancel_semiring            ~> ordered_cancel_semiring
   519     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   520     pordered_comm_ring                  ~> ordered_comm_ring
   521     pordered_comm_semiring              ~> ordered_comm_semiring
   522     pordered_ring                       ~> ordered_ring
   523     pordered_ring_abs                   ~> ordered_ring_abs
   524     pordered_semiring                   ~> ordered_semiring
   525 
   526     ordered_ab_group_add                ~> linordered_ab_group_add
   527     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   528     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   529     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   530     ordered_field                       ~> linordered_field
   531     ordered_field_no_lb                 ~> linordered_field_no_lb
   532     ordered_field_no_ub                 ~> linordered_field_no_ub
   533     ordered_field_dense_linear_order    ~> dense_linordered_field
   534     ordered_idom                        ~> linordered_idom
   535     ordered_ring                        ~> linordered_ring
   536     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   537     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   538     ordered_ring_strict                 ~> linordered_ring_strict
   539     ordered_semidom                     ~> linordered_semidom
   540     ordered_semiring                    ~> linordered_semiring
   541     ordered_semiring_1                  ~> linordered_semiring_1
   542     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   543     ordered_semiring_strict             ~> linordered_semiring_strict
   544 
   545   The following slightly odd type classes have been moved to a
   546   separate theory Library/Lattice_Algebras:
   547 
   548     lordered_ab_group_add               ~> lattice_ab_group_add
   549     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   550     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   551     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   552     lordered_ring                       ~> lattice_ring
   553 
   554 INCOMPATIBILITY.
   555 
   556 * Refined field classes:
   557   - classes division_ring_inverse_zero, field_inverse_zero,
   558     linordered_field_inverse_zero include rule inverse 0 = 0 --
   559     subsumes former division_by_zero class;
   560   - numerous lemmas have been ported from field to division_ring.
   561 INCOMPATIBILITY.
   562 
   563 * Refined algebra theorem collections:
   564   - dropped theorem group group_simps, use algebra_simps instead;
   565   - dropped theorem group ring_simps, use field_simps instead;
   566   - proper theorem collection field_simps subsumes former theorem
   567     groups field_eq_simps and field_simps;
   568   - dropped lemma eq_minus_self_iff which is a duplicate for
   569     equal_neg_zero.
   570 INCOMPATIBILITY.
   571 
   572 * Theory Finite_Set and List: some lemmas have been generalized from
   573 sets to lattices:
   574 
   575   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   576   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   577   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   578   union_Union_fold_union        ~> sup_Sup_fold_sup
   579   Inter_fold_inter              ~> Inf_fold_inf
   580   Union_fold_union              ~> Sup_fold_sup
   581   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   582   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   583   INTER_fold_inter              ~> INFI_fold_inf
   584   UNION_fold_union              ~> SUPR_fold_sup
   585 
   586 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   587 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   588 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   589 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   590 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   591 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   592 
   593 * Reorganized theory Multiset: swapped notation of pointwise and
   594 multiset order:
   595 
   596   - pointwise ordering is instance of class order with standard syntax
   597     <= and <;
   598   - multiset ordering has syntax <=# and <#; partial order properties
   599     are provided by means of interpretation with prefix
   600     multiset_order;
   601   - less duplication, less historical organization of sections,
   602     conversion from associations lists to multisets, rudimentary code
   603     generation;
   604   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   605     if needed.
   606 
   607 Renamed:
   608 
   609   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   610   multi_count_ext  ~>  multiset_ext
   611   diff_union_inverse2  ~>  diff_union_cancelR
   612 
   613 INCOMPATIBILITY.
   614 
   615 * Theory Permutation: replaced local "remove" by List.remove1.
   616 
   617 * Code generation: ML and OCaml code is decorated with signatures.
   618 
   619 * Theory List: added transpose.
   620 
   621 * Library/Nat_Bijection.thy is a collection of bijective functions
   622 between nat and other types, which supersedes the older libraries
   623 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   624 
   625   Constants:
   626   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   627   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   628   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   629   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   630   Countable.pair_encode           ~> prod_encode
   631   NatIso.prod2nat                 ~> prod_encode
   632   NatIso.nat2prod                 ~> prod_decode
   633   NatIso.sum2nat                  ~> sum_encode
   634   NatIso.nat2sum                  ~> sum_decode
   635   NatIso.list2nat                 ~> list_encode
   636   NatIso.nat2list                 ~> list_decode
   637   NatIso.set2nat                  ~> set_encode
   638   NatIso.nat2set                  ~> set_decode
   639 
   640   Lemmas:
   641   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   642   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   643   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   644   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   645   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   646   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   647   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   648   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   649   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   650   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   651   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   652   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   653   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   654 
   655 * Sledgehammer:
   656   - Renamed ATP commands:
   657     atp_info     ~> sledgehammer running_atps
   658     atp_kill     ~> sledgehammer kill_atps
   659     atp_messages ~> sledgehammer messages
   660     atp_minimize ~> sledgehammer minimize
   661     print_atps   ~> sledgehammer available_atps
   662     INCOMPATIBILITY.
   663   - Added user's manual ("isabelle doc sledgehammer").
   664   - Added option syntax and "sledgehammer_params" to customize
   665     Sledgehammer's behavior.  See the manual for details.
   666   - Modified the Isar proof reconstruction code so that it produces
   667     direct proofs rather than proofs by contradiction.  (This feature
   668     is still experimental.)
   669   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   670     full-typed mode.
   671   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   672 
   673 * Nitpick:
   674   - Added and implemented "binary_ints" and "bits" options.
   675   - Added "std" option and implemented support for nonstandard models.
   676   - Added and implemented "finitize" option to improve the precision
   677     of infinite datatypes based on a monotonicity analysis.
   678   - Added support for quotient types.
   679   - Added support for "specification" and "ax_specification"
   680     constructs.
   681   - Added support for local definitions (for "function" and
   682     "termination" proofs).
   683   - Added support for term postprocessors.
   684   - Optimized "Multiset.multiset" and "FinFun.finfun".
   685   - Improved efficiency of "destroy_constrs" optimization.
   686   - Fixed soundness bugs related to "destroy_constrs" optimization and
   687     record getters.
   688   - Fixed soundness bug related to higher-order constructors.
   689   - Fixed soundness bug when "full_descrs" is enabled.
   690   - Improved precision of set constructs.
   691   - Added "atoms" option.
   692   - Added cache to speed up repeated Kodkod invocations on the same
   693     problems.
   694   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   695     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   696     "SAT4J_Light".  INCOMPATIBILITY.
   697   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   698     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   699   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   700 
   701 * Method "induct" now takes instantiations of the form t, where t is not
   702   a variable, as a shorthand for "x == t", where x is a fresh variable.
   703   If this is not intended, t has to be enclosed in parentheses.
   704   By default, the equalities generated by definitional instantiations
   705   are pre-simplified, which may cause parameters of inductive cases
   706   to disappear, or may even delete some of the inductive cases.
   707   Use "induct (no_simp)" instead of "induct" to restore the old
   708   behaviour. The (no_simp) option is also understood by the "cases"
   709   and "nominal_induct" methods, which now perform pre-simplification, too.
   710   INCOMPATIBILITY.
   711 
   712 
   713 *** HOLCF ***
   714 
   715 * Variable names in lemmas generated by the domain package have
   716 changed; the naming scheme is now consistent with the HOL datatype
   717 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   718 
   719 * The domain package no longer defines the function "foo_copy" for
   720 recursive domain "foo".  The reach lemma is now stated directly in
   721 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   722 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   723 
   724 * Most definedness lemmas generated by the domain package (previously
   725 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   726 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   727 Proofs that used definedness lemmas as intro rules may break,
   728 potential INCOMPATIBILITY.
   729 
   730 * Induction and casedist rules generated by the domain package now
   731 declare proper case_names (one called "bottom", and one named for each
   732 constructor).  INCOMPATIBILITY.
   733 
   734 * For mutually-recursive domains, separate "reach" and "take_lemma"
   735 rules are generated for each domain, INCOMPATIBILITY.
   736 
   737   foo_bar.reach       ~> foo.reach  bar.reach
   738   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   739 
   740 * Some lemmas generated by the domain package have been renamed for
   741 consistency with the datatype package, INCOMPATIBILITY.
   742 
   743   foo.ind        ~> foo.induct
   744   foo.finite_ind ~> foo.finite_induct
   745   foo.coind      ~> foo.coinduct
   746   foo.casedist   ~> foo.exhaust
   747   foo.exhaust    ~> foo.nchotomy
   748 
   749 * For consistency with other definition packages, the fixrec package
   750 now generates qualified theorem names, INCOMPATIBILITY.
   751 
   752   foo_simps  ~> foo.simps
   753   foo_unfold ~> foo.unfold
   754   foo_induct ~> foo.induct
   755 
   756 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   757 method and internal fixrec proofs now use the default simpset instead.
   758 INCOMPATIBILITY.
   759 
   760 * The "contlub" predicate has been removed.  Proof scripts should use
   761 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   762 
   763 * The "admw" predicate has been removed, INCOMPATIBILITY.
   764 
   765 * The constants cpair, cfst, and csnd have been removed in favor of
   766 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   767 
   768 
   769 *** ML ***
   770 
   771 * Antiquotations for basic formal entities:
   772 
   773     @{class NAME}         -- type class
   774     @{class_syntax NAME}  -- syntax representation of the above
   775 
   776     @{type_name NAME}     -- logical type
   777     @{type_abbrev NAME}   -- type abbreviation
   778     @{nonterminal NAME}   -- type of concrete syntactic category
   779     @{type_syntax NAME}   -- syntax representation of any of the above
   780 
   781     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   782     @{const_abbrev NAME}  -- abbreviated constant
   783     @{const_syntax NAME}  -- syntax representation of any of the above
   784 
   785 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   786 syntax constant (cf. 'syntax' command).
   787 
   788 * Antiquotation @{make_string} inlines a function to print arbitrary
   789 values similar to the ML toplevel.  The result is compiler dependent
   790 and may fall back on "?" in certain situations.
   791 
   792 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   793 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   794 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   795 not work with the asynchronous Isar document model.
   796 
   797 * Configuration options now admit dynamic default values, depending on
   798 the context or even global references.
   799 
   800 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   801 uses an efficient external library if available (for Poly/ML).
   802 
   803 * Renamed some important ML structures, while keeping the old names
   804 for some time as aliases within the structure Legacy:
   805 
   806   OuterKeyword  ~>  Keyword
   807   OuterLex      ~>  Token
   808   OuterParse    ~>  Parse
   809   OuterSyntax   ~>  Outer_Syntax
   810   PrintMode     ~>  Print_Mode
   811   SpecParse     ~>  Parse_Spec
   812   ThyInfo       ~>  Thy_Info
   813   ThyLoad       ~>  Thy_Load
   814   ThyOutput     ~>  Thy_Output
   815   TypeInfer     ~>  Type_Infer
   816 
   817 Note that "open Legacy" simplifies porting of sources, but forgetting
   818 to remove it again will complicate porting again in the future.
   819 
   820 * Most operations that refer to a global context are named
   821 accordingly, e.g. Simplifier.global_context or
   822 ProofContext.init_global.  There are some situations where a global
   823 context actually works, but under normal circumstances one needs to
   824 pass the proper local context through the code!
   825 
   826 * Discontinued old TheoryDataFun with its copy/init operation -- data
   827 needs to be pure.  Functor Theory_Data_PP retains the traditional
   828 Pretty.pp argument to merge, which is absent in the standard
   829 Theory_Data version.
   830 
   831 * Sorts.certify_sort and derived "cert" operations for types and terms
   832 no longer minimize sorts.  Thus certification at the boundary of the
   833 inference kernel becomes invariant under addition of class relations,
   834 which is an important monotonicity principle.  Sorts are now minimized
   835 in the syntax layer only, at the boundary between the end-user and the
   836 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   837 explicitly in rare situations.
   838 
   839 * Renamed old-style Drule.standard to Drule.export_without_context, to
   840 emphasize that this is in no way a standard operation.
   841 INCOMPATIBILITY.
   842 
   843 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   844 usual for resolution.  Rare INCOMPATIBILITY.
   845 
   846 * Renamed varify/unvarify operations to varify_global/unvarify_global
   847 to emphasize that these only work in a global situation (which is
   848 quite rare).
   849 
   850 * Curried take and drop in library.ML; negative length is interpreted
   851 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   852 
   853 * Proof terms: type substitutions on proof constants now use canonical
   854 order of type variables.  INCOMPATIBILITY for tools working with proof
   855 terms.
   856 
   857 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   858 may no longer carry premises.  User-level specifications are
   859 transformed accordingly by Thm.add_axiom/add_def.
   860 
   861 
   862 *** System ***
   863 
   864 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   865 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   866 proof terms are enabled unconditionally in the new HOL-Proofs image.
   867 
   868 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   869 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   870 respectively.
   871 
   872 * Old lib/scripts/polyml-platform is superseded by the
   873 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   874 variant, even on a 64 bit machine.  The following example setting
   875 prefers 64 bit if available:
   876 
   877   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   878 
   879 * The preliminary Isabelle/jEdit application demonstrates the emerging
   880 Isabelle/Scala layer for advanced prover interaction and integration.
   881 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   882 component.
   883 
   884 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   885 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   886 similar to the default assignment of the document preparation system
   887 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   888 provides some operations for direct access to the font without asking
   889 the user for manual installation.
   890 
   891 
   892 
   893 New in Isabelle2009-1 (December 2009)
   894 -------------------------------------
   895 
   896 *** General ***
   897 
   898 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   899 one backslash should be used, even in ML sources.
   900 
   901 
   902 *** Pure ***
   903 
   904 * Locale interpretation propagates mixins along the locale hierarchy.
   905 The currently only available mixins are the equations used to map
   906 local definitions to terms of the target domain of an interpretation.
   907 
   908 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   909 loc" to print all interpretations of locale "loc" in the theory.
   910 Interpretations in proofs are not shown.
   911 
   912 * Thoroughly revised locales tutorial.  New section on conditional
   913 interpretation.
   914 
   915 * On instantiation of classes, remaining undefined class parameters
   916 are formally declared.  INCOMPATIBILITY.
   917 
   918 
   919 *** Document preparation ***
   920 
   921 * New generalized style concept for printing terms: @{foo (style) ...}
   922 instead of @{foo_style style ...}  (old form is still retained for
   923 backward compatibility).  Styles can be also applied for
   924 antiquotations prop, term_type and typeof.
   925 
   926 
   927 *** HOL ***
   928 
   929 * New proof method "smt" for a combination of first-order logic with
   930 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   931 fixed-size bitvectors; there is also basic support for higher-order
   932 features (esp. lambda abstractions).  It is an incomplete decision
   933 procedure based on external SMT solvers using the oracle mechanism;
   934 for the SMT solver Z3, this method is proof-producing.  Certificates
   935 are provided to avoid calling the external solvers solely for
   936 re-checking proofs.  Due to a remote SMT service there is no need for
   937 installing SMT solvers locally.  See src/HOL/SMT.
   938 
   939 * New commands to load and prove verification conditions generated by
   940 the Boogie program verifier or derived systems (e.g. the Verifying C
   941 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   942 
   943 * New counterexample generator tool 'nitpick' based on the Kodkod
   944 relational model finder.  See src/HOL/Tools/Nitpick and
   945 src/HOL/Nitpick_Examples.
   946 
   947 * New commands 'code_pred' and 'values' to invoke the predicate
   948 compiler and to enumerate values of inductive predicates.
   949 
   950 * A tabled implementation of the reflexive transitive closure.
   951 
   952 * New implementation of quickcheck uses generic code generator;
   953 default generators are provided for all suitable HOL types, records
   954 and datatypes.  Old quickcheck can be re-activated importing theory
   955 Library/SML_Quickcheck.
   956 
   957 * New testing tool Mirabelle for automated proof tools.  Applies
   958 several tools and tactics like sledgehammer, metis, or quickcheck, to
   959 every proof step in a theory.  To be used in batch mode via the
   960 "mirabelle" utility.
   961 
   962 * New proof method "sos" (sum of squares) for nonlinear real
   963 arithmetic (originally due to John Harison). It requires theory
   964 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   965 works well in practice on quantifier-free real arithmetic with +, -,
   966 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   967 inequalities between polynomials.  It makes use of external
   968 semidefinite programming solvers.  Method "sos" generates a
   969 certificate that can be pasted into the proof thus avoiding the need
   970 to call an external tool every time the proof is checked.  See
   971 src/HOL/Library/Sum_Of_Squares.
   972 
   973 * New method "linarith" invokes existing linear arithmetic decision
   974 procedure only.
   975 
   976 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   977 
   978 * New Sledgehammer option "Full Types" in Proof General settings menu.
   979 Causes full type information to be output to the ATPs.  This slows
   980 ATPs down considerably but eliminates a source of unsound "proofs"
   981 that fail later.
   982 
   983 * New method "metisFT": A version of metis that uses full type
   984 information in order to avoid failures of proof reconstruction.
   985 
   986 * New evaluator "approximate" approximates an real valued term using
   987 the same method as the approximation method.
   988 
   989 * Method "approximate" now supports arithmetic expressions as
   990 boundaries of intervals and implements interval splitting and Taylor
   991 series expansion.
   992 
   993 * ML antiquotation @{code_datatype} inserts definition of a datatype
   994 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   995 
   996 * New theory SupInf of the supremum and infimum operators for sets of
   997 reals.
   998 
   999 * New theory Probability, which contains a development of measure
  1000 theory, eventually leading to Lebesgue integration and probability.
  1001 
  1002 * Extended Multivariate Analysis to include derivation and Brouwer's
  1003 fixpoint theorem.
  1004 
  1005 * Reorganization of number theory, INCOMPATIBILITY:
  1006   - new number theory development for nat and int, in theories Divides
  1007     and GCD as well as in new session Number_Theory
  1008   - some constants and facts now suffixed with _nat and _int
  1009     accordingly
  1010   - former session NumberTheory now named Old_Number_Theory, including
  1011     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1012   - moved theory Pocklington from src/HOL/Library to
  1013     src/HOL/Old_Number_Theory
  1014 
  1015 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1016 lcm of finite and infinite sets. It is shown that they form a complete
  1017 lattice.
  1018 
  1019 * Class semiring_div requires superclass no_zero_divisors and proof of
  1020 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1021 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1022 generalized to class semiring_div, subsuming former theorems
  1023 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1024 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1025 INCOMPATIBILITY.
  1026 
  1027 * Refinements to lattice classes and sets:
  1028   - less default intro/elim rules in locale variant, more default
  1029     intro/elim rules in class variant: more uniformity
  1030   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1031     le_inf_iff
  1032   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1033     sup_aci)
  1034   - renamed ACI to inf_sup_aci
  1035   - new class "boolean_algebra"
  1036   - class "complete_lattice" moved to separate theory
  1037     "Complete_Lattice"; corresponding constants (and abbreviations)
  1038     renamed and with authentic syntax:
  1039     Set.Inf ~>    Complete_Lattice.Inf
  1040     Set.Sup ~>    Complete_Lattice.Sup
  1041     Set.INFI ~>   Complete_Lattice.INFI
  1042     Set.SUPR ~>   Complete_Lattice.SUPR
  1043     Set.Inter ~>  Complete_Lattice.Inter
  1044     Set.Union ~>  Complete_Lattice.Union
  1045     Set.INTER ~>  Complete_Lattice.INTER
  1046     Set.UNION ~>  Complete_Lattice.UNION
  1047   - authentic syntax for
  1048     Set.Pow
  1049     Set.image
  1050   - mere abbreviations:
  1051     Set.empty               (for bot)
  1052     Set.UNIV                (for top)
  1053     Set.inter               (for inf, formerly Set.Int)
  1054     Set.union               (for sup, formerly Set.Un)
  1055     Complete_Lattice.Inter  (for Inf)
  1056     Complete_Lattice.Union  (for Sup)
  1057     Complete_Lattice.INTER  (for INFI)
  1058     Complete_Lattice.UNION  (for SUPR)
  1059   - object-logic definitions as far as appropriate
  1060 
  1061 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1062 Un_subset_iff are explicitly deleted as default simp rules; then also
  1063 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1064 deleted to achieve the desired effect.
  1065 
  1066 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1067 rules by default any longer; the same applies to min_max.inf_absorb1
  1068 etc.  INCOMPATIBILITY.
  1069 
  1070 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1071 pred_set_conv by default.  INCOMPATIBILITY.
  1072 
  1073 * Power operations on relations and functions are now one dedicated
  1074 constant "compow" with infix syntax "^^".  Power operation on
  1075 multiplicative monoids retains syntax "^" and is now defined generic
  1076 in class power.  INCOMPATIBILITY.
  1077 
  1078 * Relation composition "R O S" now has a more standard argument order:
  1079 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1080 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1081 break, since the O_assoc rule was not rewritten like this.  Fix using
  1082 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1083 
  1084 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1085 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1086 INCOMPATIBILITY.
  1087 
  1088 * Most rules produced by inductive and datatype package have mandatory
  1089 prefixes.  INCOMPATIBILITY.
  1090 
  1091 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1092 the attribute of the same name.  Each of the theorems in the list
  1093 DERIV_intros assumes composition with an additional function and
  1094 matches a variable to the derivative, which has to be solved by the
  1095 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1096 of most elementary terms.  Former Maclauren.DERIV_tac and
  1097 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1098 INCOMPATIBILITY.
  1099 
  1100 * Code generator attributes follow the usual underscore convention:
  1101     code_unfold     replaces    code unfold
  1102     code_post       replaces    code post
  1103     etc.
  1104   INCOMPATIBILITY.
  1105 
  1106 * Renamed methods:
  1107     sizechange -> size_change
  1108     induct_scheme -> induction_schema
  1109   INCOMPATIBILITY.
  1110 
  1111 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1112 INCOMPATIBILITY, use "undefined" directly.
  1113 
  1114 * Renamed theorems:
  1115     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1116     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1117     Suc_plus1 -> Suc_eq_plus1
  1118     *anti_sym -> *antisym*
  1119     vector_less_eq_def -> vector_le_def
  1120   INCOMPATIBILITY.
  1121 
  1122 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1123 INCOMPATIBILITY.
  1124 
  1125 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1126 INCOMPATIBILITY.
  1127 
  1128 
  1129 *** HOLCF ***
  1130 
  1131 * Theory Representable defines a class "rep" of domains that are
  1132 representable (via an ep-pair) in the universal domain type "udom".
  1133 Instances are provided for all type constructors defined in HOLCF.
  1134 
  1135 * The 'new_domain' command is a purely definitional version of the
  1136 domain package, for representable domains.  Syntax is identical to the
  1137 old domain package.  The 'new_domain' package also supports indirect
  1138 recursion using previously-defined type constructors.  See
  1139 src/HOLCF/ex/New_Domain.thy for examples.
  1140 
  1141 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1142 on the left-hand side of an equation, and then performs
  1143 simplification.  Rewriting is done using rules declared with the
  1144 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1145 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1146 
  1147 * The pattern-match compiler in 'fixrec' can now handle constructors
  1148 with HOL function types.  Pattern-match combinators for the Pair
  1149 constructor are pre-configured.
  1150 
  1151 * The 'fixrec' package now produces better fixed-point induction rules
  1152 for mutually-recursive definitions:  Induction rules have conclusions
  1153 of the form "P foo bar" instead of "P <foo, bar>".
  1154 
  1155 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1156 been renamed to "below".  The name "below" now replaces "less" in many
  1157 theorem names.  (Legacy theorem names using "less" are still supported
  1158 as well.)
  1159 
  1160 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1161 patterns can be used to generate strictness rules, or to make
  1162 functions more strict (much like the bang-patterns supported by the
  1163 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1164 examples.
  1165 
  1166 
  1167 *** ML ***
  1168 
  1169 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1170 errors and run-time exceptions, including detailed source positions.
  1171 
  1172 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1173 identified entries, with some additional information such as source
  1174 position, logical grouping etc.
  1175 
  1176 * Theory and context data is now introduced by the simplified and
  1177 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1178 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1179 copy operation) is still available for some time.
  1180 
  1181 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1182 provides a high-level programming interface to synchronized state
  1183 variables with atomic update.  This works via pure function
  1184 application within a critical section -- its runtime should be as
  1185 short as possible; beware of deadlocks if critical code is nested,
  1186 either directly or indirectly via other synchronized variables!
  1187 
  1188 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1189 wraps raw ML references, explicitly indicating their non-thread-safe
  1190 behaviour.  The Isar toplevel keeps this structure open, to
  1191 accommodate Proof General as well as quick and dirty interactive
  1192 experiments with references.
  1193 
  1194 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1195 parallel tactical reasoning.
  1196 
  1197 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1198 are similar to SUBPROOF, but are slightly more flexible: only the
  1199 specified parts of the subgoal are imported into the context, and the
  1200 body tactic may introduce new subgoals and schematic variables.
  1201 
  1202 * Old tactical METAHYPS, which does not observe the proof context, has
  1203 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1204 or Subgoal.FOCUS etc.
  1205 
  1206 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1207 functors have their own ML name space there is no point to mark them
  1208 separately.)  Minor INCOMPATIBILITY.
  1209 
  1210 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1211 
  1212 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1213 INCOMPATIBILITY.
  1214 
  1215 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1216 mode, which avoids critical setmp.
  1217 
  1218 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1219 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1220 Attrib/Method.setup introduced in Isabelle2009.
  1221 
  1222 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1223 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1224 last resort.  INCOMPATIBILITY.
  1225 
  1226 * Display.pretty_thm now requires a proper context (cf. former
  1227 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1228 or even Display.pretty_thm_without_context as last resort.
  1229 INCOMPATIBILITY.
  1230 
  1231 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1232 Syntax.pretty_typ/term directly, preferably with proper context
  1233 instead of global theory.
  1234 
  1235 
  1236 *** System ***
  1237 
  1238 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1239 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1240 usedir option -q.
  1241 
  1242 * Support for additional "Isabelle components" via etc/components, see
  1243 also the system manual.
  1244 
  1245 * The isabelle makeall tool now operates on all components with
  1246 IsaMakefile, not just hardwired "logics".
  1247 
  1248 * Removed "compress" option from isabelle-process and isabelle usedir;
  1249 this is always enabled.
  1250 
  1251 * Discontinued support for Poly/ML 4.x versions.
  1252 
  1253 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1254 on a given logic image.  This requires the lighttpd webserver and is
  1255 currently supported on Linux only.
  1256 
  1257 
  1258 
  1259 New in Isabelle2009 (April 2009)
  1260 --------------------------------
  1261 
  1262 *** General ***
  1263 
  1264 * Simplified main Isabelle executables, with less surprises on
  1265 case-insensitive file-systems (such as Mac OS).
  1266 
  1267   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1268     "isatool."
  1269 
  1270   - The former "isabelle" alias for "isabelle-process" has been
  1271     removed (should rarely occur to regular users).
  1272 
  1273   - The former "isabelle-interface" and its alias "Isabelle" have been
  1274     removed (interfaces are now regular Isabelle tools).
  1275 
  1276 Within scripts and make files, the Isabelle environment variables
  1277 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1278 respectively.  (The latter are still available as legacy feature.)
  1279 
  1280 The old isabelle-interface wrapper could react in confusing ways if
  1281 the interface was uninstalled or changed otherwise.  Individual
  1282 interface tool configuration is now more explicit, see also the
  1283 Isabelle system manual.  In particular, Proof General is now available
  1284 via "isabelle emacs".
  1285 
  1286 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1287 purge installed copies of Isabelle executables and re-run "isabelle
  1288 install -p ...", or use symlinks.
  1289 
  1290 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1291 old ~/isabelle, which was slightly non-standard and apt to cause
  1292 surprises on case-insensitive file-systems (such as Mac OS).
  1293 
  1294 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1295 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1296 care is required when using older releases of Isabelle.  Note that
  1297 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1298 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1299 
  1300 * Proofs of fully specified statements are run in parallel on
  1301 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1302 a regular 4-core machine, if the initial heap space is made reasonably
  1303 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1304 
  1305 * The main reference manuals ("isar-ref", "implementation", and
  1306 "system") have been updated and extended.  Formally checked references
  1307 as hyperlinks are now available uniformly.
  1308 
  1309 
  1310 *** Pure ***
  1311 
  1312 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1313 respects.  The most important changes are listed below.  See the
  1314 Tutorial on Locales ("locales" manual) for details.
  1315 
  1316 - In locale expressions, instantiation replaces renaming.  Parameters
  1317 must be declared in a for clause.  To aid compatibility with previous
  1318 parameter inheritance, in locale declarations, parameters that are not
  1319 'touched' (instantiation position "_" or omitted) are implicitly added
  1320 with their syntax at the beginning of the for clause.
  1321 
  1322 - Syntax from abbreviations and definitions in locales is available in
  1323 locale expressions and context elements.  The latter is particularly
  1324 useful in locale declarations.
  1325 
  1326 - More flexible mechanisms to qualify names generated by locale
  1327 expressions.  Qualifiers (prefixes) may be specified in locale
  1328 expressions, and can be marked as mandatory (syntax: "name!:") or
  1329 optional (syntax "name?:").  The default depends for plain "name:"
  1330 depends on the situation where a locale expression is used: in
  1331 commands 'locale' and 'sublocale' prefixes are optional, in
  1332 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1333 implicit qualifiers derived from the parameter names of a locale are
  1334 no longer generated.
  1335 
  1336 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1337 instantiation clause in "interpretation" and "interpret" (square
  1338 brackets) is no longer available.  Use locale expressions.
  1339 
  1340 - When converting proof scripts, mandatory qualifiers in
  1341 'interpretation' and 'interpret' should be retained by default, even
  1342 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1343 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1344 in locale expressions range over a single locale instance only.
  1345 
  1346 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1347 In existing theorem specifications replace the includes element by the
  1348 respective context elements of the included locale, omitting those
  1349 that are already present in the theorem specification.  Multiple
  1350 assume elements of a locale should be replaced by a single one
  1351 involving the locale predicate.  In the proof body, declarations (most
  1352 notably theorems) may be regained by interpreting the respective
  1353 locales in the proof context as required (command "interpret").
  1354 
  1355 If using "includes" in replacement of a target solely because the
  1356 parameter types in the theorem are not as general as in the target,
  1357 consider declaring a new locale with additional type constraints on
  1358 the parameters (context element "constrains").
  1359 
  1360 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1361 
  1362 - Locale interpretation commands no longer attempt to simplify goal.
  1363 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1364 methods intro_locales and unfold_locales to clarify.
  1365 
  1366 - Locale interpretation commands no longer accept interpretation
  1367 attributes.  INCOMPATIBILITY.
  1368 
  1369 * Class declaration: so-called "base sort" must not be given in import
  1370 list any longer, but is inferred from the specification.  Particularly
  1371 in HOL, write
  1372 
  1373     class foo = ...
  1374 
  1375 instead of
  1376 
  1377     class foo = type + ...
  1378 
  1379 * Class target: global versions of theorems stemming do not carry a
  1380 parameter prefix any longer.  INCOMPATIBILITY.
  1381 
  1382 * Class 'instance' command no longer accepts attached definitions.
  1383 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1384 
  1385 * Recovered hiding of consts, which was accidentally broken in
  1386 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1387 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1388 
  1389 * Slightly more coherent Pure syntax, with updated documentation in
  1390 isar-ref manual.  Removed locales meta_term_syntax and
  1391 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1392 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1393 directly in regular applications.
  1394 
  1395 * There is a new syntactic category "float_const" for signed decimal
  1396 fractions (e.g. 123.45 or -123.45).
  1397 
  1398 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1399 interface with 'setup' command instead.
  1400 
  1401 * Command 'local_setup' is similar to 'setup', but operates on a local
  1402 theory context.
  1403 
  1404 * The 'axiomatization' command now only works within a global theory
  1405 context.  INCOMPATIBILITY.
  1406 
  1407 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1408 hypotheses.  Sorts required in the course of reasoning need to be
  1409 covered by the constraints in the initial statement, completed by the
  1410 type instance information of the background theory.  Non-trivial sort
  1411 hypotheses, which rarely occur in practice, may be specified via
  1412 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1413 
  1414   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1415 
  1416 The result contains an implicit sort hypotheses as before --
  1417 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1418 normalization.
  1419 
  1420 * Generalized Isar history, with support for linear undo, direct state
  1421 addressing etc.
  1422 
  1423 * Changed defaults for unify configuration options:
  1424 
  1425   unify_trace_bound = 50 (formerly 25)
  1426   unify_search_bound = 60 (formerly 30)
  1427 
  1428 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1429 
  1430   a) On theory merge, the last set of code equations for a particular
  1431      constant is taken (in accordance with the policy applied by other
  1432      parts of the code generator framework).
  1433 
  1434   b) Code equations stemming from explicit declarations (e.g. code
  1435      attribute) gain priority over default code equations stemming
  1436      from definition, primrec, fun etc.
  1437 
  1438 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1439 
  1440 * Unified theorem tables for both code generators.  Thus [code
  1441 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1442 
  1443 * Command 'find_consts' searches for constants based on type and name
  1444 patterns, e.g.
  1445 
  1446     find_consts "_ => bool"
  1447 
  1448 By default, matching is against subtypes, but it may be restricted to
  1449 the whole type.  Searching by name is possible.  Multiple queries are
  1450 conjunctive and queries may be negated by prefixing them with a
  1451 hyphen:
  1452 
  1453     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1454 
  1455 * New 'find_theorems' criterion "solves" matches theorems that
  1456 directly solve the current goal (modulo higher-order unification).
  1457 
  1458 * Auto solve feature for main theorem statements: whenever a new goal
  1459 is stated, "find_theorems solves" is called; any theorems that could
  1460 solve the lemma directly are listed as part of the goal state.
  1461 Cf. associated options in Proof General Isabelle settings menu,
  1462 enabled by default, with reasonable timeout for pathological cases of
  1463 higher-order unification.
  1464 
  1465 
  1466 *** Document preparation ***
  1467 
  1468 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1469 demanding keyword 'by' and supporting the full method expression
  1470 syntax just like the Isar command 'by'.
  1471 
  1472 
  1473 *** HOL ***
  1474 
  1475 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1476 points Main and Complex_Main remain as before.
  1477 
  1478 * Logic image HOL-Plain provides a minimal HOL with the most important
  1479 tools available (inductive, datatype, primrec, ...).  This facilitates
  1480 experimentation and tool development.  Note that user applications
  1481 (and library theories) should never refer to anything below theory
  1482 Main, as before.
  1483 
  1484 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1485 experimentation due to shorter build times.
  1486 
  1487 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1488 were previously part of former HOL-Complex.  Entry point Hyperreal
  1489 remains valid, but theories formerly using Complex_Main should now use
  1490 new entry point Hypercomplex.
  1491 
  1492 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1493 Posix processes.  Avoids potentially expensive forking of the ML
  1494 process.  New thread-based implementation also works on non-Unix
  1495 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1496 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1497 commands are covered in the isar-ref manual.
  1498 
  1499 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1500 sledgehammer without local ATP installation (Vampire etc.). Other
  1501 provers may be included via suitable ML wrappers, see also
  1502 src/HOL/ATP_Linkup.thy.
  1503 
  1504 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1505 menu.
  1506 
  1507 * The metis method no longer fails because the theorem is too trivial
  1508 (contains the empty clause).
  1509 
  1510 * The metis method now fails in the usual manner, rather than raising
  1511 an exception, if it determines that it cannot prove the theorem.
  1512 
  1513 * Method "coherent" implements a prover for coherent logic (see also
  1514 src/Tools/coherent.ML).
  1515 
  1516 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1517 "undefined" is the right choice to replace "arbitrary", though
  1518 logically there is no difference.  INCOMPATIBILITY.
  1519 
  1520 * Command "value" now integrates different evaluation mechanisms.  The
  1521 result of the first successful evaluation mechanism is printed.  In
  1522 square brackets a particular named evaluation mechanisms may be
  1523 specified (currently, [SML], [code] or [nbe]).  See further
  1524 src/HOL/ex/Eval_Examples.thy.
  1525 
  1526 * Normalization by evaluation now allows non-leftlinear equations.
  1527 Declare with attribute [code nbe].
  1528 
  1529 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1530 as the structured Isar versions "cases" and "induct", cf. the
  1531 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1532 are now presented as a list of individual projections
  1533 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1534 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1535 rare situations a different rule is selected --- notably nested tuple
  1536 elimination instead of former prod.exhaust: use explicit (case_tac t
  1537 rule: prod.exhaust) here.
  1538 
  1539 * Attributes "cases", "induct", "coinduct" support "del" option.
  1540 
  1541 * Removed fact "case_split_thm", which duplicates "case_split".
  1542 
  1543 * The option datatype has been moved to a new theory Option.  Renamed
  1544 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1545 
  1546 * New predicate "strict_mono" classifies strict functions on partial
  1547 orders.  With strict functions on linear orders, reasoning about
  1548 (in)equalities is facilitated by theorems "strict_mono_eq",
  1549 "strict_mono_less_eq" and "strict_mono_less".
  1550 
  1551 * Some set operations are now proper qualified constants with
  1552 authentic syntax.  INCOMPATIBILITY:
  1553 
  1554     op Int ~>   Set.Int
  1555     op Un ~>    Set.Un
  1556     INTER ~>    Set.INTER
  1557     UNION ~>    Set.UNION
  1558     Inter ~>    Set.Inter
  1559     Union ~>    Set.Union
  1560     {} ~>       Set.empty
  1561     UNIV ~>     Set.UNIV
  1562 
  1563 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1564 theory Set.
  1565 
  1566 * Auxiliary class "itself" has disappeared -- classes without any
  1567 parameter are treated as expected by the 'class' command.
  1568 
  1569 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1570 
  1571 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1572 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1573 
  1574 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1575 method "approximation".  It proves formulas on real values by using
  1576 interval arithmetic.  In the formulas are also the transcendental
  1577 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1578 allowed. For examples see
  1579 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1580 
  1581 * Theory "Reflection" now resides in HOL/Library.
  1582 
  1583 * Entry point to Word library now simply named "Word".
  1584 INCOMPATIBILITY.
  1585 
  1586 * Made source layout more coherent with logical distribution
  1587 structure:
  1588 
  1589     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1590     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1591     src/HOL/Library/GCD.thy ~> src/HOL/
  1592     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1593     src/HOL/Library/Parity.thy ~> src/HOL/
  1594     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1595     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1596     src/HOL/Real/Lubs.thy ~> src/HOL/
  1597     src/HOL/Real/PReal.thy ~> src/HOL/
  1598     src/HOL/Real/Rational.thy ~> src/HOL/
  1599     src/HOL/Real/RComplete.thy ~> src/HOL/
  1600     src/HOL/Real/RealDef.thy ~> src/HOL/
  1601     src/HOL/Real/RealPow.thy ~> src/HOL/
  1602     src/HOL/Real/Real.thy ~> src/HOL/
  1603     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1604     src/HOL/Complex/Complex.thy ~> src/HOL/
  1605     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1606     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1607     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1608     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1609     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1610     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1611     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1612     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1613     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1614     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1615     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1616     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1617     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1618     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1619     src/HOL/Real/Float ~> src/HOL/Library/
  1620     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1621     src/HOL/Real/RealVector.thy ~> src/HOL/
  1622 
  1623     src/HOL/arith_data.ML ~> src/HOL/Tools
  1624     src/HOL/hologic.ML ~> src/HOL/Tools
  1625     src/HOL/simpdata.ML ~> src/HOL/Tools
  1626     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1627     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1628     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1629     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1630     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1631     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1632     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1633 
  1634     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1635     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1636     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1637     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1638     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1639     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1640 
  1641 * If methods "eval" and "evaluation" encounter a structured proof
  1642 state with !!/==>, only the conclusion is evaluated to True (if
  1643 possible), avoiding strange error messages.
  1644 
  1645 * Method "sizechange" automates termination proofs using (a
  1646 modification of) the size-change principle.  Requires SAT solver.  See
  1647 src/HOL/ex/Termination.thy for examples.
  1648 
  1649 * Simplifier: simproc for let expressions now unfolds if bound
  1650 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1651 
  1652 * Method "arith": Linear arithmetic now ignores all inequalities when
  1653 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1654 
  1655 * New attribute "arith" for facts that should always be used
  1656 automatically by arithmetic. It is intended to be used locally in
  1657 proofs, e.g.
  1658 
  1659   assumes [arith]: "x > 0"
  1660 
  1661 Global usage is discouraged because of possible performance impact.
  1662 
  1663 * New classes "top" and "bot" with corresponding operations "top" and
  1664 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1665 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1666 
  1667 * Changed definition lemma "less_fun_def" in order to provide an
  1668 instance for preorders on functions; use lemma "less_le" instead.
  1669 INCOMPATIBILITY.
  1670 
  1671 * Theory Orderings: class "wellorder" moved here, with explicit
  1672 induction rule "less_induct" as assumption.  For instantiation of
  1673 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1674 INCOMPATIBILITY.
  1675 
  1676 * Theory Orderings: added class "preorder" as superclass of "order".
  1677 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1678 etc. slightly changed.  Some theorems named order_class.* now named
  1679 preorder_class.*.
  1680 
  1681 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1682 "diag" to "Id_on".
  1683 
  1684 * Theory Finite_Set: added a new fold combinator of type
  1685 
  1686   ('a => 'b => 'b) => 'b => 'a set => 'b
  1687 
  1688 Occasionally this is more convenient than the old fold combinator
  1689 which is now defined in terms of the new one and renamed to
  1690 fold_image.
  1691 
  1692 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1693 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1694 extended with further lemmas!).  At the moment both still exist but
  1695 the former will disappear at some point.
  1696 
  1697 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1698 class recpower.  Type-specific simp rules for various recpower types
  1699 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1700 
  1701 rat_power_0    -> power_0
  1702 rat_power_Suc  -> power_Suc
  1703 realpow_0      -> power_0
  1704 realpow_Suc    -> power_Suc
  1705 complexpow_0   -> power_0
  1706 complexpow_Suc -> power_Suc
  1707 power_poly_0   -> power_0
  1708 power_poly_Suc -> power_Suc
  1709 
  1710 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1711 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1712 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1713 of lemmas from Divides has been generalized from nat to class
  1714 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1715 renames resulting from duplicate elimination:
  1716 
  1717     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1718     zero_dvd_iff ~>         dvd_0_left_iff
  1719     dvd_0 ~>                dvd_0_right
  1720     DIVISION_BY_ZERO_DIV ~> div_by_0
  1721     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1722     mult_div ~>             div_mult_self2_is_id
  1723     mult_mod ~>             mod_mult_self2_is_0
  1724 
  1725 * Theory IntDiv: removed many lemmas that are instances of class-based
  1726 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1727 rename old lemmas as follows:
  1728 
  1729 dvd_diff               -> nat_dvd_diff
  1730 dvd_zminus_iff         -> dvd_minus_iff
  1731 mod_add1_eq            -> mod_add_eq
  1732 mod_mult1_eq           -> mod_mult_right_eq
  1733 mod_mult1_eq'          -> mod_mult_left_eq
  1734 mod_mult_distrib_mod   -> mod_mult_eq
  1735 nat_mod_add_left_eq    -> mod_add_left_eq
  1736 nat_mod_add_right_eq   -> mod_add_right_eq
  1737 nat_mod_div_trivial    -> mod_div_trivial
  1738 nat_mod_mod_trivial    -> mod_mod_trivial
  1739 zdiv_zadd_self1        -> div_add_self1
  1740 zdiv_zadd_self2        -> div_add_self2
  1741 zdiv_zmult_self1       -> div_mult_self2_is_id
  1742 zdiv_zmult_self2       -> div_mult_self1_is_id
  1743 zdvd_triv_left         -> dvd_triv_left
  1744 zdvd_triv_right        -> dvd_triv_right
  1745 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1746 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1747 zmod_zadd_left_eq      -> mod_add_left_eq
  1748 zmod_zadd_right_eq     -> mod_add_right_eq
  1749 zmod_zadd_self1        -> mod_add_self1
  1750 zmod_zadd_self2        -> mod_add_self2
  1751 zmod_zadd1_eq          -> mod_add_eq
  1752 zmod_zdiff1_eq         -> mod_diff_eq
  1753 zmod_zdvd_zmod         -> mod_mod_cancel
  1754 zmod_zmod_cancel       -> mod_mod_cancel
  1755 zmod_zmult_self1       -> mod_mult_self2_is_0
  1756 zmod_zmult_self2       -> mod_mult_self1_is_0
  1757 zmod_1                 -> mod_by_1
  1758 zdiv_1                 -> div_by_1
  1759 zdvd_abs1              -> abs_dvd_iff
  1760 zdvd_abs2              -> dvd_abs_iff
  1761 zdvd_refl              -> dvd_refl
  1762 zdvd_trans             -> dvd_trans
  1763 zdvd_zadd              -> dvd_add
  1764 zdvd_zdiff             -> dvd_diff
  1765 zdvd_zminus_iff        -> dvd_minus_iff
  1766 zdvd_zminus2_iff       -> minus_dvd_iff
  1767 zdvd_zmultD            -> dvd_mult_right
  1768 zdvd_zmultD2           -> dvd_mult_left
  1769 zdvd_zmult_mono        -> mult_dvd_mono
  1770 zdvd_0_right           -> dvd_0_right
  1771 zdvd_0_left            -> dvd_0_left_iff
  1772 zdvd_1_left            -> one_dvd
  1773 zminus_dvd_iff         -> minus_dvd_iff
  1774 
  1775 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1776 
  1777 * The real numbers offer decimal input syntax: 12.34 is translated
  1778 into 1234/10^2. This translation is not reversed upon output.
  1779 
  1780 * Theory Library/Polynomial defines an abstract type 'a poly of
  1781 univariate polynomials with coefficients of type 'a.  In addition to
  1782 the standard ring operations, it also supports div and mod.  Code
  1783 generation is also supported, using list-style constructors.
  1784 
  1785 * Theory Library/Inner_Product defines a class of real_inner for real
  1786 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1787 => real.  Class real_inner is a subclass of real_normed_vector from
  1788 theory RealVector.
  1789 
  1790 * Theory Library/Product_Vector provides instances for the product
  1791 type 'a * 'b of several classes from RealVector and Inner_Product.
  1792 Definitions of addition, subtraction, scalar multiplication, norms,
  1793 and inner products are included.
  1794 
  1795 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1796 addition to the field operations, numerals and case syntax are also
  1797 supported.
  1798 
  1799 * Theory Library/Diagonalize provides constructive version of Cantor's
  1800 first diagonalization argument.
  1801 
  1802 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1803 zlcm (for int); carried together from various gcd/lcm developements in
  1804 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1805 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1806 may recover tupled syntax as follows:
  1807 
  1808     hide (open) const gcd
  1809     abbreviation gcd where
  1810       "gcd == (%(a, b). GCD.gcd a b)"
  1811     notation (output)
  1812       GCD.gcd ("gcd '(_, _')")
  1813 
  1814 The same works for lcm, zgcd, zlcm.
  1815 
  1816 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1817 instantiations for algebraic structures.  Removed some duplicate
  1818 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1819 
  1820 * ML antiquotation @{code} takes a constant as argument and generates
  1821 corresponding code in background and inserts name of the corresponding
  1822 resulting ML value/function/datatype constructor binding in place.
  1823 All occurrences of @{code} with a single ML block are generated
  1824 simultaneously.  Provides a generic and safe interface for
  1825 instrumentalizing code generation.  See
  1826 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1827 In future you ought to refrain from ad-hoc compiling generated SML
  1828 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1829 cannot refer to constants for which user-defined serializations are
  1830 set.  Refer to the corresponding ML counterpart directly in that
  1831 cases.
  1832 
  1833 * Command 'rep_datatype': instead of theorem names the command now
  1834 takes a list of terms denoting the constructors of the type to be
  1835 represented as datatype.  The characteristic theorems have to be
  1836 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1837 have disappeared in favour of existing ones:
  1838 
  1839     unit_induct                 ~> unit.induct
  1840     prod_induct                 ~> prod.induct
  1841     sum_induct                  ~> sum.induct
  1842     Suc_Suc_eq                  ~> nat.inject
  1843     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1844 
  1845 
  1846 *** HOL-Algebra ***
  1847 
  1848 * New locales for orders and lattices where the equivalence relation
  1849 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1850 locales use a record structure with field eq for the equivalence.
  1851 
  1852 * New theory of factorial domains.
  1853 
  1854 * Units_l_inv and Units_r_inv are now simp rules by default.
  1855 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1856 and/or r_inv will now also require deletion of these lemmas.
  1857 
  1858 * Renamed the following theorems, INCOMPATIBILITY:
  1859 
  1860 UpperD ~> Upper_memD
  1861 LowerD ~> Lower_memD
  1862 least_carrier ~> least_closed
  1863 greatest_carrier ~> greatest_closed
  1864 greatest_Lower_above ~> greatest_Lower_below
  1865 one_zero ~> carrier_one_zero
  1866 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1867 
  1868 
  1869 *** HOL-Nominal ***
  1870 
  1871 * Nominal datatypes can now contain type-variables.
  1872 
  1873 * Commands 'nominal_inductive' and 'equivariance' work with local
  1874 theory targets.
  1875 
  1876 * Nominal primrec can now works with local theory targets and its
  1877 specification syntax now conforms to the general format as seen in
  1878 'inductive' etc.
  1879 
  1880 * Method "perm_simp" honours the standard simplifier attributes
  1881 (no_asm), (no_asm_use) etc.
  1882 
  1883 * The new predicate #* is defined like freshness, except that on the
  1884 left hand side can be a set or list of atoms.
  1885 
  1886 * Experimental command 'nominal_inductive2' derives strong induction
  1887 principles for inductive definitions.  In contrast to
  1888 'nominal_inductive', which can only deal with a fixed number of
  1889 binders, it can deal with arbitrary expressions standing for sets of
  1890 atoms to be avoided.  The only inductive definition we have at the
  1891 moment that needs this generalisation is the typing rule for Lets in
  1892 the algorithm W:
  1893 
  1894  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1895  -----------------------------------------------------------------
  1896          Gamma |- Let x be t1 in t2 : T2
  1897 
  1898 In this rule one wants to avoid all the binders that are introduced by
  1899 "close Gamma T1".  We are looking for other examples where this
  1900 feature might be useful.  Please let us know.
  1901 
  1902 
  1903 *** HOLCF ***
  1904 
  1905 * Reimplemented the simplification procedure for proving continuity
  1906 subgoals.  The new simproc is extensible; users can declare additional
  1907 continuity introduction rules with the attribute [cont2cont].
  1908 
  1909 * The continuity simproc now uses a different introduction rule for
  1910 solving continuity subgoals on terms with lambda abstractions.  In
  1911 some rare cases the new simproc may fail to solve subgoals that the
  1912 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1913 Potential INCOMPATIBILITY.
  1914 
  1915 * Command 'fixrec': specification syntax now conforms to the general
  1916 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1917 examples.  INCOMPATIBILITY.
  1918 
  1919 
  1920 *** ZF ***
  1921 
  1922 * Proof of Zorn's Lemma for partial orders.
  1923 
  1924 
  1925 *** ML ***
  1926 
  1927 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1928 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1929 depends on multithreading, so timouts will not work before Poly/ML
  1930 5.2.1!
  1931 
  1932 * High-level support for concurrent ML programming, see
  1933 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1934 particularly convenient to organize independent functional
  1935 computations.  The concept of "synchronized variables" provides a
  1936 higher-order interface for components with shared state, avoiding the
  1937 delicate details of mutexes and condition variables.  (Requires
  1938 Poly/ML 5.2.1 or later.)
  1939 
  1940 * ML bindings produced via Isar commands are stored within the Isar
  1941 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1942 become thread-safe and work with undo as expected (concerning
  1943 top-level bindings, not side-effects on global references).
  1944 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1945 compiler at runtime; really global bindings need to be given outside a
  1946 theory.  (Requires Poly/ML 5.2 or later.)
  1947 
  1948 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1949 context.  Top-level ML bindings are stored within the proof context in
  1950 a purely sequential fashion, disregarding the nested proof structure.
  1951 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1952 proof.  (Requires Poly/ML 5.2 or later.)
  1953 
  1954 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1955 and Method.setup, as well as Isar commands 'attribute_setup' and
  1956 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1957 existing code accordingly, or use plain 'setup' together with old
  1958 Method.add_method.
  1959 
  1960 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1961 to 'a -> thm, while results are always tagged with an authentic oracle
  1962 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1963 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1964 accordingly.  Note that extra performance may be gained by producing
  1965 the cterm carefully, avoiding slow Thm.cterm_of.
  1966 
  1967 * Simplified interface for defining document antiquotations via
  1968 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1969 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1970 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1971 examples.
  1972 
  1973 * More systematic treatment of long names, abstract name bindings, and
  1974 name space operations.  Basic operations on qualified names have been
  1975 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1976 Long_Name.append.  Old type bstring has been mostly replaced by
  1977 abstract type binding (see structure Binding), which supports precise
  1978 qualification by packages and local theory targets, as well as proper
  1979 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1980 bstring values into Binding.name, or better pass through abstract
  1981 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1982 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1983 
  1984 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1985 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1986 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1987 
  1988 * Disposed old type and term read functions (Sign.read_def_typ,
  1989 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1990 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1991 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1992 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1993 resort for legacy applications.
  1994 
  1995 * Disposed old declarations, tactics, tactic combinators that refer to
  1996 the simpset or claset of an implicit theory (such as Addsimps,
  1997 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1998 embedded ML text, or local_simpset_of with a proper context passed as
  1999 explicit runtime argument.
  2000 
  2001 * Rules and tactics that read instantiations (read_instantiate,
  2002 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2003 context, which is required for parsing and type-checking.  Moreover,
  2004 the variables are specified as plain indexnames, not string encodings
  2005 thereof.  INCOMPATIBILITY.
  2006 
  2007 * Generic Toplevel.add_hook interface allows to analyze the result of
  2008 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2009 for theorem dependency output of transactions resulting in a new
  2010 theory state.
  2011 
  2012 * ML antiquotations: block-structured compilation context indicated by
  2013 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2014 
  2015   @{binding name}                         - basic name binding
  2016   @{let ?pat = term}                      - term abbreviation (HO matching)
  2017   @{note name = fact}                     - fact abbreviation
  2018   @{thm fact}                             - singleton fact (with attributes)
  2019   @{thms fact}                            - general fact (with attributes)
  2020   @{lemma prop by method}                 - singleton goal
  2021   @{lemma prop by meth1 meth2}            - singleton goal
  2022   @{lemma prop1 ... propN by method}      - general goal
  2023   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2024   @{lemma (open) ...}                     - open derivation
  2025 
  2026 
  2027 *** System ***
  2028 
  2029 * The Isabelle "emacs" tool provides a specific interface to invoke
  2030 Proof General / Emacs, with more explicit failure if that is not
  2031 installed (the old isabelle-interface script silently falls back on
  2032 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2033 installation location of the Proof General distribution.
  2034 
  2035 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2036 the Isabelle process into a JVM/Scala application.  See
  2037 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2038 process wrapper has been discontinued.)
  2039 
  2040 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2041 
  2042 * Various status messages (with exact source position information) are
  2043 emitted, if proper markup print mode is enabled.  This allows
  2044 user-interface components to provide detailed feedback on internal
  2045 prover operations.
  2046 
  2047 
  2048 
  2049 New in Isabelle2008 (June 2008)
  2050 -------------------------------
  2051 
  2052 *** General ***
  2053 
  2054 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2055 and updated, with formally checked references as hyperlinks.
  2056 
  2057 * Theory loader: use_thy (and similar operations) no longer set the
  2058 implicit ML context, which was occasionally hard to predict and in
  2059 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2060 provides a proper context already.
  2061 
  2062 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2063 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2064 'use' within a theory file will do the job.
  2065 
  2066 * Name space merge now observes canonical order, i.e. the second space
  2067 is inserted into the first one, while existing entries in the first
  2068 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2069 swap theory imports.
  2070 
  2071 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2072 INCOMPATIBILITY in identifier syntax etc.
  2073 
  2074 * Outer syntax: string tokens no longer admit escaped white space,
  2075 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2076 white space without escapes.
  2077 
  2078 * Outer syntax: string tokens may contain arbitrary character codes
  2079 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2080 "foo_bar".
  2081 
  2082 
  2083 *** Pure ***
  2084 
  2085 * Context-dependent token translations.  Default setup reverts locally
  2086 fixed variables, and adds hilite markup for undeclared frees.
  2087 
  2088 * Unused theorems can be found using the new command 'unused_thms'.
  2089 There are three ways of invoking it:
  2090 
  2091 (1) unused_thms
  2092      Only finds unused theorems in the current theory.
  2093 
  2094 (2) unused_thms thy_1 ... thy_n -
  2095      Finds unused theorems in the current theory and all of its ancestors,
  2096      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2097 
  2098 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2099      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2100      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2101      their ancestors.
  2102 
  2103 In order to increase the readability of the list produced by
  2104 unused_thms, theorems that have been created by a particular instance
  2105 of a theory command such as 'inductive' or 'function' are considered
  2106 to belong to the same "group", meaning that if at least one theorem in
  2107 this group is used, the other theorems in the same group are no longer
  2108 reported as unused.  Moreover, if all theorems in the group are
  2109 unused, only one theorem in the group is displayed.
  2110 
  2111 Note that proof objects have to be switched on in order for
  2112 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2113 usually the case when using Proof General with the default settings).
  2114 
  2115 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2116 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2117 duplicate fact bindings, or even accidental fact duplications.  Note
  2118 that tools may maintain dynamically scoped facts systematically, using
  2119 PureThy.add_thms_dynamic.
  2120 
  2121 * Command 'hide' now allows to hide from "fact" name space as well.
  2122 
  2123 * Eliminated destructive theorem database, simpset, claset, and
  2124 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2125 update of theories within ML code.
  2126 
  2127 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2128 INCOMPATIBILITY, object-logics depending on former Pure require
  2129 additional setup PureThy.old_appl_syntax_setup; object-logics
  2130 depending on former CPure need to refer to Pure.
  2131 
  2132 * Commands 'use' and 'ML' are now purely functional, operating on
  2133 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2134 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2135 INCOMPATIBILITY.
  2136 
  2137 * Command 'setup': discontinued implicit version with ML reference.
  2138 
  2139 * Instantiation target allows for simultaneous specification of class
  2140 instance operations together with an instantiation proof.
  2141 Type-checking phase allows to refer to class operations uniformly.
  2142 See src/HOL/Complex/Complex.thy for an Isar example and
  2143 src/HOL/Library/Eval.thy for an ML example.
  2144 
  2145 * Indexing of literal facts: be more serious about including only
  2146 facts from the visible specification/proof context, but not the
  2147 background context (locale etc.).  Affects `prop` notation and method
  2148 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2149 situations.
  2150 
  2151 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2152 "(open)" option, which used to expose internal bound variables to the
  2153 proof text.
  2154 
  2155 * Isar statements: removed obsolete case "rule_context".
  2156 INCOMPATIBILITY, better use explicit fixes/assumes.
  2157 
  2158 * Locale proofs: default proof step now includes 'unfold_locales';
  2159 hence 'proof' without argument may be used to unfold locale
  2160 predicates.
  2161 
  2162 
  2163 *** Document preparation ***
  2164 
  2165 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2166 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2167 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2168 spot); renamed link color from "darkblue" to "linkcolor" (default
  2169 value unchanged, can be redefined via \definecolor); no longer sets
  2170 "a4paper" option (unnecessary or even intrusive).
  2171 
  2172 * Antiquotation @{lemma A method} proves proposition A by the given
  2173 method (either a method name or a method name plus (optional) method
  2174 arguments in parentheses) and prints A just like @{prop A}.
  2175 
  2176 
  2177 *** HOL ***
  2178 
  2179 * New primrec package.  Specification syntax conforms in style to
  2180 definition/function/....  No separate induction rule is provided.  The
  2181 "primrec" command distinguishes old-style and new-style specifications
  2182 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2183 When adjusting theories, beware: constants stemming from new-style
  2184 primrec specifications have authentic syntax.
  2185 
  2186 * Metis prover is now an order of magnitude faster, and also works
  2187 with multithreading.
  2188 
  2189 * Metis: the maximum number of clauses that can be produced from a
  2190 theorem is now given by the attribute max_clauses.  Theorems that
  2191 exceed this number are ignored, with a warning printed.
  2192 
  2193 * Sledgehammer no longer produces structured proofs by default. To
  2194 enable, declare [[sledgehammer_full = true]].  Attributes
  2195 reconstruction_modulus, reconstruction_sorts renamed
  2196 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2197 
  2198 * Method "induct_scheme" derives user-specified induction rules
  2199 from well-founded induction and completeness of patterns. This factors
  2200 out some operations that are done internally by the function package
  2201 and makes them available separately.  See
  2202 src/HOL/ex/Induction_Scheme.thy for examples.
  2203 
  2204 * More flexible generation of measure functions for termination
  2205 proofs: Measure functions can be declared by proving a rule of the
  2206 form "is_measure f" and giving it the [measure_function] attribute.
  2207 The "is_measure" predicate is logically meaningless (always true), and
  2208 just guides the heuristic.  To find suitable measure functions, the
  2209 termination prover sets up the goal "is_measure ?f" of the appropriate
  2210 type and generates all solutions by prolog-style backwards proof using
  2211 the declared rules.
  2212 
  2213 This setup also deals with rules like 
  2214 
  2215   "is_measure f ==> is_measure (list_size f)"
  2216 
  2217 which accommodates nested datatypes that recurse through lists.
  2218 Similar rules are predeclared for products and option types.
  2219 
  2220 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2221 
  2222   INCOMPATIBILITIES:
  2223 
  2224   - Definitions of overloaded constants on sets have to be replaced by
  2225     definitions on => and bool.
  2226 
  2227   - Some definitions of overloaded operators on sets can now be proved
  2228     using the definitions of the operators on => and bool.  Therefore,
  2229     the following theorems have been renamed:
  2230 
  2231       subset_def   -> subset_eq
  2232       psubset_def  -> psubset_eq
  2233       set_diff_def -> set_diff_eq
  2234       Compl_def    -> Compl_eq
  2235       Sup_set_def  -> Sup_set_eq
  2236       Inf_set_def  -> Inf_set_eq
  2237       sup_set_def  -> sup_set_eq
  2238       inf_set_def  -> inf_set_eq
  2239 
  2240   - Due to the incompleteness of the HO unification algorithm, some
  2241     rules such as subst may require manual instantiation, if some of
  2242     the unknowns in the rule is a set.
  2243 
  2244   - Higher order unification and forward proofs:
  2245     The proof pattern
  2246 
  2247       have "P (S::'a set)" <...>
  2248       then have "EX S. P S" ..
  2249 
  2250     no longer works (due to the incompleteness of the HO unification
  2251     algorithm) and must be replaced by the pattern
  2252 
  2253       have "EX S. P S"
  2254       proof
  2255         show "P S" <...>
  2256       qed
  2257 
  2258   - Calculational reasoning with subst (or similar rules):
  2259     The proof pattern
  2260 
  2261       have "P (S::'a set)" <...>
  2262       also have "S = T" <...>
  2263       finally have "P T" .
  2264 
  2265     no longer works (for similar reasons as the previous example) and
  2266     must be replaced by something like
  2267 
  2268       have "P (S::'a set)" <...>
  2269       moreover have "S = T" <...>
  2270       ultimately have "P T" by simp
  2271 
  2272   - Tactics or packages written in ML code:
  2273     Code performing pattern matching on types via
  2274 
  2275       Type ("set", [T]) => ...
  2276 
  2277     must be rewritten. Moreover, functions like strip_type or
  2278     binder_types no longer return the right value when applied to a
  2279     type of the form
  2280 
  2281       T1 => ... => Tn => U => bool
  2282 
  2283     rather than
  2284 
  2285       T1 => ... => Tn => U set
  2286 
  2287 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2288 Wellfounded_Relations to theory Wellfounded.
  2289 
  2290 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2291 
  2292 * Class finite no longer treats UNIV as class parameter.  Use class
  2293 enum from theory Library/Enum instead to achieve a similar effect.
  2294 INCOMPATIBILITY.
  2295 
  2296 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2297 and "Cons".  INCOMPATIBILITY.
  2298 
  2299 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2300 Potential INCOMPATIBILITY.
  2301 
  2302 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2303 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2304 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2305 
  2306 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2307 the same name in theory Orderings:
  2308 
  2309   less_trans
  2310   less_linear
  2311   le_imp_less_or_eq
  2312   le_less_trans
  2313   less_le_trans
  2314   less_not_sym
  2315   less_asym
  2316 
  2317 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2318 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2319 and different variable names.
  2320 
  2321 * Library/Option_ord.thy: Canonical order on option type.
  2322 
  2323 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2324 finite maps.
  2325 
  2326 * Library/Countable.thy: Type class for countable types.
  2327 
  2328 * Theory Int: The representation of numerals has changed.  The infix
  2329 operator BIT and the bit datatype with constructors B0 and B1 have
  2330 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2331 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2332 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2333 accordingly.
  2334 
  2335 * Theory Nat: definition of <= and < on natural numbers no longer
  2336 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2337 le_def and less_def have disappeared.  Consider lemmas not_less
  2338 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2339 
  2340 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2341 (whose purpose mainly is for various fold_set functionals) have been
  2342 abandoned in favor of the existing algebraic classes
  2343 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2344 lower_semilattice (resp. upper_semilattice) and linorder.
  2345 INCOMPATIBILITY.
  2346 
  2347 * Theory Transitive_Closure: induct and cases rules now declare proper
  2348 case_names ("base" and "step").  INCOMPATIBILITY.
  2349 
  2350 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2351 lattices.  The form set-specific version is available as
  2352 Inductive.lfp_ordinal_induct_set.
  2353 
  2354 * Renamed theorems "power.simps" to "power_int.simps".
  2355 INCOMPATIBILITY.
  2356 
  2357 * Class semiring_div provides basic abstract properties of semirings
  2358 with division and modulo operations.  Subsumes former class dvd_mod.
  2359 
  2360 * Merged theories IntDef, Numeral and IntArith into unified theory
  2361 Int.  INCOMPATIBILITY.
  2362 
  2363 * Theory Library/Code_Index: type "index" now represents natural
  2364 numbers rather than integers.  INCOMPATIBILITY.
  2365 
  2366 * New class "uminus" with operation "uminus" (split of from class
  2367 "minus" which now only has operation "minus", binary).
  2368 INCOMPATIBILITY.
  2369 
  2370 * Constants "card", "internal_split", "option_map" now with authentic
  2371 syntax.  INCOMPATIBILITY.
  2372 
  2373 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2374 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2375 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2376 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2377 Sup_set_def, le_def, less_def, option_map_def now with object
  2378 equality.  INCOMPATIBILITY.
  2379 
  2380 * Records. Removed K_record, and replaced it by pure lambda term
  2381 %x. c. The simplifier setup is now more robust against eta expansion.
  2382 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2383 
  2384 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2385 
  2386 * Library/ListVector: new theory of arithmetic vector operations.
  2387 
  2388 * Library/Order_Relation: new theory of various orderings as sets of
  2389 pairs.  Defines preorders, partial orders, linear orders and
  2390 well-orders on sets and on types.
  2391 
  2392 
  2393 *** ZF ***
  2394 
  2395 * Renamed some theories to allow to loading both ZF and HOL in the
  2396 same session:
  2397 
  2398   Datatype  -> Datatype_ZF
  2399   Inductive -> Inductive_ZF
  2400   Int       -> Int_ZF
  2401   IntDiv    -> IntDiv_ZF
  2402   Nat       -> Nat_ZF
  2403   List      -> List_ZF
  2404   Main      -> Main_ZF
  2405 
  2406 INCOMPATIBILITY: ZF theories that import individual theories below
  2407 Main might need to be adapted.  Regular theory Main is still
  2408 available, as trivial extension of Main_ZF.
  2409 
  2410 
  2411 *** ML ***
  2412 
  2413 * ML within Isar: antiquotation @{const name} or @{const
  2414 name(typargs)} produces statically-checked Const term.
  2415 
  2416 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2417 (of the same name).  Removed obsolete print command.
  2418 
  2419 * Removed obsolete "use_legacy_bindings" function.
  2420 
  2421 * The ``print mode'' is now a thread-local value derived from a global
  2422 template (the former print_mode reference), thus access becomes
  2423 non-critical.  The global print_mode reference is for session
  2424 management only; user-code should use print_mode_value,
  2425 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2426 
  2427 * Functions system/system_out provide a robust way to invoke external
  2428 shell commands, with propagation of interrupts (requires Poly/ML
  2429 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2430 
  2431 
  2432 *** System ***
  2433 
  2434 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2435 in accordance with Proof General 3.7, which prefers GNU emacs.
  2436 
  2437 * isatool tty runs Isabelle process with plain tty interaction;
  2438 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2439 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2440 
  2441 * isatool browser now works with Cygwin as well, using general
  2442 "javapath" function defined in Isabelle process environment.
  2443 
  2444 * YXML notation provides a simple and efficient alternative to
  2445 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2446 isatool yxml as described in the Isabelle system manual.
  2447 
  2448 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2449 provides general wrapper for managing an Isabelle process in a robust
  2450 fashion, with ``cooked'' output from stdin/stderr.
  2451 
  2452 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2453 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2454 
  2455 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2456 way of changing the user's settings is via
  2457 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2458 script.
  2459 
  2460 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2461 cores of the underlying machine, which is a good starting point for
  2462 optimal performance tuning.  The corresponding usedir option -M allows
  2463 "max" as an alias for "0".  WARNING: does not work on certain versions
  2464 of Mac OS (with Poly/ML 5.1).
  2465 
  2466 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2467 adverse effect of Isabelle flooding interactive front-ends (notably
  2468 ProofGeneral / XEmacs).
  2469 
  2470 
  2471 
  2472 New in Isabelle2007 (November 2007)
  2473 -----------------------------------
  2474 
  2475 *** General ***
  2476 
  2477 * More uniform information about legacy features, notably a
  2478 warning/error of "Legacy feature: ...", depending on the state of the
  2479 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2480 legacy features will disappear eventually.
  2481 
  2482 * Theory syntax: the header format ``theory A = B + C:'' has been
  2483 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2484 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2485 
  2486 * Theory syntax: the old non-Isar theory file format has been
  2487 discontinued altogether.  Note that ML proof scripts may still be used
  2488 with Isar theories; migration is usually quite simple with the ML
  2489 function use_legacy_bindings.  INCOMPATIBILITY.
  2490 
  2491 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2492 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2493 quotes.
  2494 
  2495 * Theory loader: be more serious about observing the static theory
  2496 header specifications (including optional directories), but not the
  2497 accidental file locations of previously successful loads.  The strict
  2498 update policy of former update_thy is now already performed by
  2499 use_thy, so the former has been removed; use_thys updates several
  2500 theories simultaneously, just as 'imports' within a theory header
  2501 specification, but without merging the results.  Potential
  2502 INCOMPATIBILITY: may need to refine theory headers and commands
  2503 ROOT.ML which depend on load order.
  2504 
  2505 * Theory loader: optional support for content-based file
  2506 identification, instead of the traditional scheme of full physical
  2507 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2508 (cf. the system manual).  The new scheme allows to work with
  2509 non-finished theories in persistent session images, such that source
  2510 files may be moved later on without requiring reloads.
  2511 
  2512 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2513 file (with the same base name as the theory) are considered a legacy
  2514 feature, which will disappear eventually. Even now, the theory loader
  2515 no longer maintains dependencies on such files.
  2516 
  2517 * Syntax: the scope for resolving ambiguities via type-inference is
  2518 now limited to individual terms, instead of whole simultaneous
  2519 specifications as before. This greatly reduces the complexity of the
  2520 syntax module and improves flexibility by separating parsing and
  2521 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2522 'fixes' etc.) are required in rare situations.
  2523 
  2524 * Syntax: constants introduced by new-style packages ('definition',
  2525 'abbreviation' etc.) are passed through the syntax module in
  2526 ``authentic mode''. This means that associated mixfix annotations
  2527 really stick to such constants, independently of potential name space
  2528 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2529 trees are represented slightly differently, may need to adapt syntax
  2530 translations accordingly. Use CONST marker in 'translations' and
  2531 @{const_syntax} antiquotation in 'parse_translation' etc.
  2532 
  2533 * Legacy goal package: reduced interface to the bare minimum required
  2534 to keep existing proof scripts running.  Most other user-level
  2535 functions are now part of the OldGoals structure, which is *not* open
  2536 by default (consider isatool expandshort before open OldGoals).
  2537 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2538 these tend to cause confusion about the actual goal (!) context being
  2539 used here, which is not necessarily the same as the_context().
  2540 
  2541 * Command 'find_theorems': supports "*" wild-card in "name:"
  2542 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2543 support a specific search form (see ProofGeneral/CHANGES).
  2544 
  2545 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2546 by default, which means that "prems" (and also "fixed variables") are
  2547 suppressed from proof state output.  Note that the ProofGeneral
  2548 settings mechanism allows to change and save options persistently, but
  2549 older versions of Isabelle will fail to start up if a negative prems
  2550 limit is imposed.
  2551 
  2552 * Local theory targets may be specified by non-nested blocks of
  2553 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2554 contain definitions, theorems etc., including any derived mechanism
  2555 that has been implemented on top of these primitives.  This concept
  2556 generalizes the existing ``theorem (in ...)'' towards more versatility
  2557 and scalability.
  2558 
  2559 * Proof General interface: proper undo of final 'end' command;
  2560 discontinued Isabelle/classic mode (ML proof scripts).
  2561 
  2562 
  2563 *** Document preparation ***
  2564 
  2565 * Added antiquotation @{theory name} which prints the given name,
  2566 after checking that it refers to a valid ancestor theory in the
  2567 current context.
  2568 
  2569 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2570 check the given source text as ML type/structure, printing verbatim.
  2571 
  2572 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2573 "c args == rhs" given in the current context.  (Any number of
  2574 arguments may be given on the LHS.)
  2575 
  2576 
  2577 *** Pure ***
  2578 
  2579 * The 'class' package offers a combination of axclass and locale to
  2580 achieve Haskell-like type classes in Isabelle.  Definitions and
  2581 theorems within a class context produce both relative results (with
  2582 implicit parameters according to the locale context), and polymorphic
  2583 constants with qualified polymorphism (according to the class
  2584 context).  Within the body context of a 'class' target, a separate
  2585 syntax layer ("user space type system") takes care of converting
  2586 between global polymorphic consts and internal locale representation.
  2587 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2588 "isatool doc classes" provides a tutorial.
  2589 
  2590 * Generic code generator framework allows to generate executable
  2591 code for ML and Haskell (including Isabelle classes).  A short usage
  2592 sketch:
  2593 
  2594     internal compilation:
  2595         export_code <list of constants (term syntax)> in SML
  2596     writing SML code to a file:
  2597         export_code <list of constants (term syntax)> in SML <filename>
  2598     writing OCaml code to a file:
  2599         export_code <list of constants (term syntax)> in OCaml <filename>
  2600     writing Haskell code to a bunch of files:
  2601         export_code <list of constants (term syntax)> in Haskell <filename>
  2602 
  2603     evaluating closed propositions to True/False using code generation:
  2604         method ``eval''
  2605 
  2606 Reasonable default setup of framework in HOL.
  2607 
  2608 Theorem attributs for selecting and transforming function equations theorems:
  2609 
  2610     [code fun]:        select a theorem as function equation for a specific constant
  2611     [code fun del]:    deselect a theorem as function equation for a specific constant
  2612     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2613     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2614 
  2615 User-defined serializations (target in {SML, OCaml, Haskell}):
  2616 
  2617     code_const <and-list of constants (term syntax)>
  2618       {(target) <and-list of const target syntax>}+
  2619 
  2620     code_type <and-list of type constructors>
  2621       {(target) <and-list of type target syntax>}+
  2622 
  2623     code_instance <and-list of instances>
  2624       {(target)}+
  2625         where instance ::= <type constructor> :: <class>
  2626 
  2627     code_class <and_list of classes>
  2628       {(target) <and-list of class target syntax>}+
  2629         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2630 
  2631 code_instance and code_class only are effective to target Haskell.
  2632 
  2633 For example usage see src/HOL/ex/Codegenerator.thy and
  2634 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2635 generation from Isabelle/HOL theories is available via "isatool doc
  2636 codegen".
  2637 
  2638 * Code generator: consts in 'consts_code' Isar commands are now
  2639 referred to by usual term syntax (including optional type
  2640 annotations).
  2641 
  2642 * Command 'no_translations' removes translation rules from theory
  2643 syntax.
  2644 
  2645 * Overloaded definitions are now actually checked for acyclic
  2646 dependencies.  The overloading scheme is slightly more general than
  2647 that of Haskell98, although Isabelle does not demand an exact
  2648 correspondence to type class and instance declarations.
  2649 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2650 exotic versions of overloading -- at the discretion of the user!
  2651 
  2652 Polymorphic constants are represented via type arguments, i.e. the
  2653 instantiation that matches an instance against the most general
  2654 declaration given in the signature.  For example, with the declaration
  2655 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2656 as c(nat).  Overloading is essentially simultaneous structural
  2657 recursion over such type arguments.  Incomplete specification patterns
  2658 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2659 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2660 Command 'print_theory' outputs the normalized system of recursive
  2661 equations, see section "definitions".
  2662 
  2663 * Configuration options are maintained within the theory or proof
  2664 context (with name and type bool/int/string), providing a very simple
  2665 interface to a poor-man's version of general context data.  Tools may
  2666 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2667 these values using Config.get etc.  Users may change options via an
  2668 associated attribute of the same name.  This form of context
  2669 declaration works particularly well with commands 'declare' or
  2670 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2671 very easy to avoid global references, which would not observe Isar
  2672 toplevel undo/redo and fail to work with multithreading.
  2673 
  2674 Various global ML references of Pure and HOL have been turned into
  2675 configuration options:
  2676 
  2677   Unify.search_bound		unify_search_bound
  2678   Unify.trace_bound		unify_trace_bound
  2679   Unify.trace_simp		unify_trace_simp
  2680   Unify.trace_types		unify_trace_types
  2681   Simplifier.simp_depth_limit	simp_depth_limit
  2682   Blast.depth_limit		blast_depth_limit
  2683   DatatypeProp.dtK		datatype_distinctness_limit
  2684   fast_arith_neq_limit  	fast_arith_neq_limit
  2685   fast_arith_split_limit	fast_arith_split_limit
  2686 
  2687 * Named collections of theorems may be easily installed as context
  2688 data using the functor NamedThmsFun (see also
  2689 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2690 attributes; there is also a toplevel print command.  This facility is
  2691 just a common case of general context data, which is the preferred way
  2692 for anything more complex than just a list of facts in canonical
  2693 order.
  2694 
  2695 * Isar: command 'declaration' augments a local theory by generic
  2696 declaration functions written in ML.  This enables arbitrary content
  2697 being added to the context, depending on a morphism that tells the
  2698 difference of the original declaration context wrt. the application
  2699 context encountered later on.
  2700 
  2701 * Isar: proper interfaces for simplification procedures.  Command
  2702 'simproc_setup' declares named simprocs (with match patterns, and body
  2703 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2704 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2705 
  2706 * Isar: an extra pair of brackets around attribute declarations
  2707 abbreviates a theorem reference involving an internal dummy fact,
  2708 which will be ignored later --- only the effect of the attribute on
  2709 the background context will persist.  This form of in-place
  2710 declarations is particularly useful with commands like 'declare' and
  2711 'using', for example ``have A using [[simproc a]] by simp''.
  2712 
  2713 * Isar: method "assumption" (and implicit closing of subproofs) now
  2714 takes simple non-atomic goal assumptions into account: after applying
  2715 an assumption as a rule the resulting subgoals are solved by atomic
  2716 assumption steps.  This is particularly useful to finish 'obtain'
  2717 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2718 without referring to the original premise "!!x. P x ==> thesis" in the
  2719 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2720 more permissive.
  2721 
  2722 * Isar: implicit use of prems from the Isar proof context is
  2723 considered a legacy feature.  Common applications like ``have A .''
  2724 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2725 referencing facts explicitly here improves readability and
  2726 maintainability of proof texts.
  2727 
  2728 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2729 the obtained context from the course of reasoning!  For example:
  2730 
  2731   assume "EX x y. A x & B y"   -- "any previous fact"
  2732   then guess x and y by clarify
  2733 
  2734 This technique is potentially adventurous, depending on the facts and
  2735 proof tools being involved here.
  2736 
  2737 * Isar: known facts from the proof context may be specified as literal
  2738 propositions, using ASCII back-quote syntax.  This works wherever
  2739 named facts used to be allowed so far, in proof commands, proof
  2740 methods, attributes etc.  Literal facts are retrieved from the context
  2741 according to unification of type and term parameters.  For example,
  2742 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2743 theorems in the current context, then these are valid literal facts:
  2744 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2745 
  2746 There is also a proof method "fact" which does the same composition
  2747 for explicit goal states, e.g. the following proof texts coincide with
  2748 certain special cases of literal facts:
  2749 
  2750   have "A" by fact                 ==  note `A`
  2751   have "A ==> B" by fact           ==  note `A ==> B`
  2752   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2753   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2754 
  2755 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2756 outer syntax.  Thus symbolic identifiers may be used without
  2757 additional white space in declarations like this: ``assume *: A''.
  2758 
  2759 * Isar: 'print_facts' prints all local facts of the current context,
  2760 both named and unnamed ones.
  2761 
  2762 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2763 
  2764   def x == "t" and y == "u"
  2765 
  2766 * Isar: added command 'unfolding', which is structurally similar to
  2767 'using', but affects both the goal state and facts by unfolding given
  2768 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2769 'unfolded' attribute may be replaced by first-class proof text.
  2770 
  2771 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2772 and command 'unfolding' now all support object-level equalities
  2773 (potentially conditional).  The underlying notion of rewrite rule is
  2774 analogous to the 'rule_format' attribute, but *not* that of the
  2775 Simplifier (which is usually more generous).
  2776 
  2777 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2778 premises of a theorem by n. Useful in conjunction with drule.
  2779 
  2780 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2781 method expression within a sandbox consisting of the first N
  2782 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2783 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2784 simplifies all new goals that emerge from applying rule foo to the
  2785 originally first one.
  2786 
  2787 * Isar: schematic goals are no longer restricted to higher-order
  2788 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2789 expected.
  2790 
  2791 * Isar: the conclusion of a long theorem statement is now either
  2792 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2793 (essentially a disjunction of cases with local parameters and
  2794 assumptions).  The latter allows to express general elimination rules
  2795 adequately; in this notation common elimination rules look like this:
  2796 
  2797   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2798     assumes "EX x. P x"
  2799     obtains x where "P x"
  2800 
  2801   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2802     assumes "A & B"
  2803     obtains A and B
  2804 
  2805   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2806     assumes "A | B"
  2807     obtains
  2808       A
  2809     | B
  2810 
  2811 The subsequent classical rules even refer to the formal "thesis"
  2812 explicitly:
  2813 
  2814   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2815     obtains "~ thesis"
  2816 
  2817   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2818     obtains "thesis ==> something"
  2819 
  2820 The actual proof of an 'obtains' statement is analogous to that of the
  2821 Isar proof element 'obtain', only that there may be several cases.
  2822 Optional case names may be specified in parentheses; these will be
  2823 available both in the present proof and as annotations in the
  2824 resulting rule, for later use with the 'cases' method (cf. attribute
  2825 case_names).
  2826 
  2827 * Isar: the assumptions of a long theorem statement are available as
  2828 "assms" fact in the proof context.  This is more appropriate than the
  2829 (historical) "prems", which refers to all assumptions of the current
  2830 context, including those from the target locale, proof body etc.
  2831 
  2832 * Isar: 'print_statement' prints theorems from the current theory or
  2833 proof context in long statement form, according to the syntax of a
  2834 top-level lemma.
  2835 
  2836 * Isar: 'obtain' takes an optional case name for the local context
  2837 introduction rule (default "that").
  2838 
  2839 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2840 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2841 to occur.
  2842 
  2843 * Pure: syntax "CONST name" produces a fully internalized constant
  2844 according to the current context.  This is particularly useful for
  2845 syntax translations that should refer to internal constant
  2846 representations independently of name spaces.
  2847 
  2848 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2849 instead of "FOO ". This allows multiple binder declarations to coexist
  2850 in the same context.  INCOMPATIBILITY.
  2851 
  2852 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2853 primitive that also works in a locale context (both for constants and
  2854 fixed variables). Type declaration and internal syntactic representation
  2855 of given constants retrieved from the context. Likewise, the
  2856 'no_notation' command allows to remove given syntax annotations from the
  2857 current context.
  2858 
  2859 * Isar/locales: new derived specification elements 'axiomatization',
  2860 'definition', 'abbreviation', which support type-inference, admit
  2861 object-level specifications (equality, equivalence).  See also the
  2862 isar-ref manual.  Examples:
  2863 
  2864   axiomatization
  2865     eq  (infix "===" 50) where
  2866     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2867 
  2868   definition "f x y = x + y + 1"
  2869   definition g where "g x = f x x"
  2870 
  2871   abbreviation
  2872     neq  (infix "=!=" 50) where
  2873     "x =!= y == ~ (x === y)"
  2874 
  2875 These specifications may be also used in a locale context.  Then the
  2876 constants being introduced depend on certain fixed parameters, and the
  2877 constant name is qualified by the locale base name.  An internal
  2878 abbreviation takes care for convenient input and output, making the
  2879 parameters implicit and using the original short name.  See also
  2880 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2881 entities from a monomorphic theory.
  2882 
  2883 Presently, abbreviations are only available 'in' a target locale, but
  2884 not inherited by general import expressions.  Also note that
  2885 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2886 'translations' in common applications.  The "no_abbrevs" print mode
  2887 prevents folding of abbreviations in term output.
  2888 
  2889 Concrete syntax is attached to specified constants in internal form,
  2890 independently of name spaces.  The parse tree representation is
  2891 slightly different -- use 'notation' instead of raw 'syntax', and
  2892 'translations' with explicit "CONST" markup to accommodate this.
  2893 
  2894 * Pure/Isar: unified syntax for new-style specification mechanisms
  2895 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2896 full type inference and dummy patterns ("_").  For example:
  2897 
  2898   definition "K x _ = x"
  2899 
  2900   inductive conj for A B
  2901   where "A ==> B ==> conj A B"
  2902 
  2903 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2904 the current context.  Print mode "no_abbrevs" prevents inversion of
  2905 abbreviations on output.
  2906 
  2907 * Isar/locales: improved parameter handling: use of locales "var" and
  2908 "struct" no longer necessary; - parameter renamings are no longer
  2909 required to be injective.  For example, this allows to define
  2910 endomorphisms as locale endom = homom mult mult h.
  2911 
  2912 * Isar/locales: changed the way locales with predicates are defined.
  2913 Instead of accumulating the specification, the imported expression is
  2914 now an interpretation.  INCOMPATIBILITY: different normal form of
  2915 locale expressions.  In particular, in interpretations of locales with
  2916 predicates, goals repesenting already interpreted fragments are not
  2917 removed automatically.  Use methods `intro_locales' and
  2918 `unfold_locales'; see below.
  2919 
  2920 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2921 provide backward reasoning on locales predicates.  The methods are
  2922 aware of interpretations and discharge corresponding goals.
  2923 `intro_locales' is less aggressive then `unfold_locales' and does not
  2924 unfold predicates to assumptions.
  2925 
  2926 * Isar/locales: the order in which locale fragments are accumulated
  2927 has changed.  This enables to override declarations from fragments due
  2928 to interpretations -- for example, unwanted simp rules.
  2929 
  2930 * Isar/locales: interpretation in theories and proof contexts has been
  2931 extended.  One may now specify (and prove) equations, which are
  2932 unfolded in interpreted theorems.  This is useful for replacing
  2933 defined concepts (constants depending on locale parameters) by
  2934 concepts already existing in the target context.  Example:
  2935 
  2936   interpretation partial_order ["op <= :: [int, int] => bool"]
  2937     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2938 
  2939 Typically, the constant `partial_order.less' is created by a
  2940 definition specification element in the context of locale
  2941 partial_order.
  2942 
  2943 * Method "induct": improved internal context management to support
  2944 local fixes and defines on-the-fly. Thus explicit meta-level
  2945 connectives !!  and ==> are rarely required anymore in inductive goals
  2946 (using object-logic connectives for this purpose has been long
  2947 obsolete anyway). Common proof patterns are explained in
  2948 src/HOL/Induct/Common_Patterns.thy, see also
  2949 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2950 examples.
  2951 
  2952 * Method "induct": improved handling of simultaneous goals. Instead of
  2953 introducing object-level conjunction, the statement is now split into
  2954 several conclusions, while the corresponding symbolic cases are nested
  2955 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2956 see src/HOL/Induct/Common_Patterns.thy, for example.
  2957 
  2958 * Method "induct": mutual induction rules are now specified as a list
  2959 of rule sharing the same induction cases. HOL packages usually provide
  2960 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2961 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2962 mutual induction rules differently, i.e. like this:
  2963 
  2964   (induct rule: foo_bar.inducts)
  2965   (induct set: foo bar)
  2966   (induct pred: foo bar)
  2967   (induct type: foo bar)
  2968 
  2969 The ML function ProjectRule.projections turns old-style rules into the
  2970 new format.
  2971 
  2972 * Method "coinduct": dual of induction, see
  2973 src/HOL/Library/Coinductive_List.thy for various examples.
  2974 
  2975 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2976 considered a legacy feature.
  2977 
  2978 * Attribute "symmetric" produces result with standardized schematic
  2979 variables (index 0).  Potential INCOMPATIBILITY.
  2980 
  2981 * Simplifier: by default the simplifier trace only shows top level
  2982 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2983 default. Thus there is less danger of being flooded by the trace. The
  2984 trace indicates where parts have been suppressed.
  2985   
  2986 * Provers/classical: removed obsolete classical version of elim_format
  2987 attribute; classical elim/dest rules are now treated uniformly when
  2988 manipulating the claset.
  2989 
  2990 * Provers/classical: stricter checks to ensure that supplied intro,
  2991 dest and elim rules are well-formed; dest and elim rules must have at
  2992 least one premise.
  2993 
  2994 * Provers/classical: attributes dest/elim/intro take an optional
  2995 weight argument for the rule (just as the Pure versions).  Weights are
  2996 ignored by automated tools, but determine the search order of single
  2997 rule steps.
  2998 
  2999 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3000 where the body does not mention the bound variable.  Note that dummy
  3001 patterns implicitly depend on their context of bounds, which makes
  3002 "{_. _}" match any set comprehension as expected.  Potential
  3003 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3004 constant "_idtdummy" in the binding position.
  3005 
  3006 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3007 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3008 for example "A -> B" => "Pi A (%_. B)".
  3009 
  3010 * Pure: 'class_deps' command visualizes the subclass relation, using
  3011 the graph browser tool.
  3012 
  3013 * Pure: 'print_theory' now suppresses certain internal declarations by
  3014 default; use '!' option for full details.
  3015 
  3016 
  3017 *** HOL ***
  3018 
  3019 * Method "metis" proves goals by applying the Metis general-purpose
  3020 resolution prover (see also http://gilith.com/software/metis/).
  3021 Examples are in the directory MetisExamples.  WARNING: the
  3022 Isabelle/HOL-Metis integration does not yet work properly with
  3023 multi-threading.
  3024   
  3025 * Command 'sledgehammer' invokes external automatic theorem provers as
  3026 background processes.  It generates calls to the "metis" method if
  3027 successful. These can be pasted into the proof.  Users do not have to
  3028 wait for the automatic provers to return.  WARNING: does not really
  3029 work with multi-threading.
  3030 
  3031 * New "auto_quickcheck" feature tests outermost goal statements for
  3032 potential counter-examples.  Controlled by ML references
  3033 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3034 5000 milliseconds).  Fails silently if statements is outside of
  3035 executable fragment, or any other codgenerator problem occurs.
  3036 
  3037 * New constant "undefined" with axiom "undefined x = undefined".
  3038 
  3039 * Added class "HOL.eq", allowing for code generation with polymorphic
  3040 equality.
  3041 
  3042 * Some renaming of class constants due to canonical name prefixing in
  3043 the new 'class' package:
  3044 
  3045     HOL.abs ~> HOL.abs_class.abs
  3046     HOL.divide ~> HOL.divide_class.divide
  3047     0 ~> HOL.zero_class.zero
  3048     1 ~> HOL.one_class.one
  3049     op + ~> HOL.plus_class.plus
  3050     op - ~> HOL.minus_class.minus
  3051     uminus ~> HOL.minus_class.uminus
  3052     op * ~> HOL.times_class.times
  3053     op < ~> HOL.ord_class.less
  3054     op <= > HOL.ord_class.less_eq
  3055     Nat.power ~> Power.power_class.power
  3056     Nat.size ~> Nat.size_class.size
  3057     Numeral.number_of ~> Numeral.number_class.number_of
  3058     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3059     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3060     Orderings.min ~> Orderings.ord_class.min
  3061     Orderings.max ~> Orderings.ord_class.max
  3062     Divides.op div ~> Divides.div_class.div
  3063     Divides.op mod ~> Divides.div_class.mod
  3064     Divides.op dvd ~> Divides.div_class.dvd
  3065 
  3066 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3067 
  3068 a) User-defined constants using any of the names "plus", "minus",
  3069 "times", "less" or "less_eq". The standard syntax translations for
  3070 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3071 names.
  3072 
  3073 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3074 INCOMPATIBILITY: use more specific names.
  3075 
  3076 c) Permutative equations (e.g. "a + b = b + a")
  3077 Since the change of names also changes the order of terms, permutative
  3078 rewrite rules may get applied in a different order. Experience shows
  3079 that this is rarely the case (only two adaptions in the whole Isabelle
  3080 distribution).  INCOMPATIBILITY: rewrite proofs
  3081 
  3082 d) ML code directly refering to constant names
  3083 This in general only affects hand-written proof tactics, simprocs and
  3084 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3085 Consider using @{const_name} antiquotation.
  3086 
  3087 * New class "default" with associated constant "default".
  3088 
  3089 * Function "sgn" is now overloaded and available on int, real, complex
  3090 (and other numeric types), using class "sgn".  Two possible defs of
  3091 sgn are given as equational assumptions in the classes sgn_if and
  3092 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3093 INCOMPATIBILITY.
  3094 
  3095 * Locale "partial_order" now unified with class "order" (cf. theory
  3096 Orderings), added parameter "less".  INCOMPATIBILITY.
  3097 
  3098 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3099 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3100 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3101 
  3102 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3103 changed order of proof goals in instance proofs.
  3104 
  3105 * The transitivity reasoner for partial and linear orders is set up
  3106 for classes "order" and "linorder".  Instances of the reasoner are available
  3107 in all contexts importing or interpreting the corresponding locales.
  3108 Method "order" invokes the reasoner separately; the reasoner
  3109 is also integrated with the Simplifier as a solver.  Diagnostic
  3110 command 'print_orders' shows the available instances of the reasoner
  3111 in the current context.
  3112 
  3113 * Localized monotonicity predicate in theory "Orderings"; integrated
  3114 lemmas max_of_mono and min_of_mono with this predicate.
  3115 INCOMPATIBILITY.
  3116 
  3117 * Formulation of theorem "dense" changed slightly due to integration
  3118 with new class dense_linear_order.
  3119 
  3120 * Uniform lattice theory development in HOL.
  3121 
  3122     constants "meet" and "join" now named "inf" and "sup"
  3123     constant "Meet" now named "Inf"
  3124 
  3125     classes "meet_semilorder" and "join_semilorder" now named
  3126       "lower_semilattice" and "upper_semilattice"
  3127     class "lorder" now named "lattice"
  3128     class "comp_lat" now named "complete_lattice"
  3129 
  3130     Instantiation of lattice classes allows explicit definitions
  3131     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3132 
  3133   INCOMPATIBILITY.  Theorem renames:
  3134 
  3135     meet_left_le            ~> inf_le1
  3136     meet_right_le           ~> inf_le2
  3137     join_left_le            ~> sup_ge1
  3138     join_right_le           ~> sup_ge2
  3139     meet_join_le            ~> inf_sup_ord
  3140     le_meetI                ~> le_infI
  3141     join_leI                ~> le_supI
  3142     le_meet                 ~> le_inf_iff
  3143     le_join                 ~> ge_sup_conv
  3144     meet_idempotent         ~> inf_idem
  3145     join_idempotent         ~> sup_idem
  3146     meet_comm               ~> inf_commute
  3147     join_comm               ~> sup_commute
  3148     meet_leI1               ~> le_infI1
  3149     meet_leI2               ~> le_infI2
  3150     le_joinI1               ~> le_supI1
  3151     le_joinI2               ~> le_supI2
  3152     meet_assoc              ~> inf_assoc
  3153     join_assoc              ~> sup_assoc
  3154     meet_left_comm          ~> inf_left_commute
  3155     meet_left_idempotent    ~> inf_left_idem
  3156     join_left_comm          ~> sup_left_commute
  3157     join_left_idempotent    ~> sup_left_idem
  3158     meet_aci                ~> inf_aci
  3159     join_aci                ~> sup_aci
  3160     le_def_meet             ~> le_iff_inf
  3161     le_def_join             ~> le_iff_sup
  3162     join_absorp2            ~> sup_absorb2
  3163     join_absorp1            ~> sup_absorb1
  3164     meet_absorp1            ~> inf_absorb1
  3165     meet_absorp2            ~> inf_absorb2
  3166     meet_join_absorp        ~> inf_sup_absorb
  3167     join_meet_absorp        ~> sup_inf_absorb
  3168     distrib_join_le         ~> distrib_sup_le
  3169     distrib_meet_le         ~> distrib_inf_le
  3170 
  3171     add_meet_distrib_left   ~> add_inf_distrib_left
  3172     add_join_distrib_left   ~> add_sup_distrib_left
  3173     is_join_neg_meet        ~> is_join_neg_inf
  3174     is_meet_neg_join        ~> is_meet_neg_sup
  3175     add_meet_distrib_right  ~> add_inf_distrib_right
  3176     add_join_distrib_right  ~> add_sup_distrib_right
  3177     add_meet_join_distribs  ~> add_sup_inf_distribs
  3178     join_eq_neg_meet        ~> sup_eq_neg_inf
  3179     meet_eq_neg_join        ~> inf_eq_neg_sup
  3180     add_eq_meet_join        ~> add_eq_inf_sup
  3181     meet_0_imp_0            ~> inf_0_imp_0
  3182     join_0_imp_0            ~> sup_0_imp_0
  3183     meet_0_eq_0             ~> inf_0_eq_0
  3184     join_0_eq_0             ~> sup_0_eq_0
  3185     neg_meet_eq_join        ~> neg_inf_eq_sup
  3186     neg_join_eq_meet        ~> neg_sup_eq_inf
  3187     join_eq_if              ~> sup_eq_if
  3188 
  3189     mono_meet               ~> mono_inf
  3190     mono_join               ~> mono_sup
  3191     meet_bool_eq            ~> inf_bool_eq
  3192     join_bool_eq            ~> sup_bool_eq
  3193     meet_fun_eq             ~> inf_fun_eq
  3194     join_fun_eq             ~> sup_fun_eq
  3195     meet_set_eq             ~> inf_set_eq
  3196     join_set_eq             ~> sup_set_eq
  3197     meet1_iff               ~> inf1_iff
  3198     meet2_iff               ~> inf2_iff
  3199     meet1I                  ~> inf1I
  3200     meet2I                  ~> inf2I
  3201     meet1D1                 ~> inf1D1
  3202     meet2D1                 ~> inf2D1
  3203     meet1D2                 ~> inf1D2
  3204     meet2D2                 ~> inf2D2
  3205     meet1E                  ~> inf1E
  3206     meet2E                  ~> inf2E
  3207     join1_iff               ~> sup1_iff
  3208     join2_iff               ~> sup2_iff
  3209     join1I1                 ~> sup1I1
  3210     join2I1                 ~> sup2I1
  3211     join1I1                 ~> sup1I1
  3212     join2I2                 ~> sup1I2
  3213     join1CI                 ~> sup1CI
  3214     join2CI                 ~> sup2CI
  3215     join1E                  ~> sup1E
  3216     join2E                  ~> sup2E
  3217 
  3218     is_meet_Meet            ~> is_meet_Inf
  3219     Meet_bool_def           ~> Inf_bool_def
  3220     Meet_fun_def            ~> Inf_fun_def
  3221     Meet_greatest           ~> Inf_greatest
  3222     Meet_lower              ~> Inf_lower
  3223     Meet_set_def            ~> Inf_set_def
  3224 
  3225     Sup_def                 ~> Sup_Inf
  3226     Sup_bool_eq             ~> Sup_bool_def
  3227     Sup_fun_eq              ~> Sup_fun_def
  3228     Sup_set_eq              ~> Sup_set_def
  3229 
  3230     listsp_meetI            ~> listsp_infI
  3231     listsp_meet_eq          ~> listsp_inf_eq
  3232 
  3233     meet_min                ~> inf_min
  3234     join_max                ~> sup_max
  3235 
  3236 * Added syntactic class "size"; overloaded constant "size" now has
  3237 type "'a::size ==> bool"
  3238 
  3239 * Internal reorganisation of `size' of datatypes: size theorems
  3240 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3241 simplification rules by default!); theorems "prod.size" now named
  3242 "*.size".
  3243 
  3244 * Class "div" now inherits from class "times" rather than "type".
  3245 INCOMPATIBILITY.
  3246 
  3247 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3248 Linorder etc.  have disappeared; operations defined in terms of
  3249 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3250 
  3251 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3252 
  3253 * HOL-Word: New extensive library and type for generic, fixed size
  3254 machine words, with arithemtic, bit-wise, shifting and rotating
  3255 operations, reflection into int, nat, and bool lists, automation for
  3256 linear arithmetic (by automatic reflection into nat or int), including
  3257 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3258 arithmetic type classes, supporting automatic simplification of
  3259 numerals on all operations.
  3260 
  3261 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3262 
  3263 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3264 
  3265 * Code generator library theories:
  3266   - Code_Integer represents HOL integers by big integer literals in target
  3267     languages.
  3268   - Code_Char represents HOL characters by character literals in target
  3269     languages.
  3270   - Code_Char_chr like Code_Char, but also offers treatment of character
  3271     codes; includes Code_Integer.
  3272   - Executable_Set allows to generate code for finite sets using lists.
  3273   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3274     denominator).
  3275   - Executable_Real implements a subset of real numbers, namly those
  3276     representable by rational numbers.
  3277   - Efficient_Nat implements natural numbers by integers, which in general will
  3278     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3279     includes Code_Integer.
  3280   - Code_Index provides an additional datatype index which is mapped to
  3281     target-language built-in integers.
  3282   - Code_Message provides an additional datatype message_string which is isomorphic to
  3283     strings; messages are mapped to target-language strings.
  3284 
  3285 * New package for inductive predicates
  3286 
  3287   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3288 
  3289     inductive
  3290       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3291       for z_1 :: U_1 and ... and z_n :: U_m
  3292     where
  3293       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3294     | ...
  3295 
  3296   with full support for type-inference, rather than
  3297 
  3298     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3299 
  3300     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3301     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3302 
  3303     inductive "s z_1 ... z_m"
  3304     intros
  3305       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3306       ...
  3307 
  3308   For backward compatibility, there is a wrapper allowing inductive
  3309   sets to be defined with the new package via
  3310 
  3311     inductive_set
  3312       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3313       for z_1 :: U_1 and ... and z_n :: U_m
  3314     where
  3315       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3316     | ...
  3317 
  3318   or
  3319 
  3320     inductive_set
  3321       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3322       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3323       for z_1 :: U_1 and ... and z_n :: U_m
  3324     where
  3325       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3326     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3327     | ...
  3328 
  3329   if the additional syntax "p ..." is required.
  3330 
  3331   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3332   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3333 
  3334   INCOMPATIBILITIES:
  3335 
  3336   - Since declaration and definition of inductive sets or predicates
  3337     is no longer separated, abbreviations involving the newly
  3338     introduced sets or predicates must be specified together with the
  3339     introduction rules after the 'where' keyword (see above), rather
  3340     than before the actual inductive definition.
  3341 
  3342   - The variables in induction and elimination rules are now
  3343     quantified in the order of their occurrence in the introduction
  3344     rules, rather than in alphabetical order. Since this may break
  3345     some proofs, these proofs either have to be repaired, e.g. by
  3346     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3347     statements of the form
  3348 
  3349       case (rule_i a_i_1 ... a_i_{k_i})
  3350 
  3351     or the old order of quantification has to be restored by explicitly adding
  3352     meta-level quantifiers in the introduction rules, i.e.
  3353 
  3354       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3355 
  3356   - The format of the elimination rules is now
  3357 
  3358       p z_1 ... z_m x_1 ... x_n ==>
  3359         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3360         ==> ... ==> P
  3361 
  3362     for predicates and
  3363 
  3364       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3365         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3366         ==> ... ==> P
  3367 
  3368     for sets rather than
  3369 
  3370       x : s z_1 ... z_m ==>
  3371         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3372         ==> ... ==> P
  3373 
  3374     This may require terms in goals to be expanded to n-tuples
  3375     (e.g. using case_tac or simplification with the split_paired_all
  3376     rule) before the above elimination rule is applicable.
  3377 
  3378   - The elimination or case analysis rules for (mutually) inductive
  3379     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3380     list of rules "p_1_..._p_k.elims" is no longer available.
  3381 
  3382 * New package "function"/"fun" for general recursive functions,
  3383 supporting mutual and nested recursion, definitions in local contexts,
  3384 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3385 for small examples, and the separate tutorial on the function
  3386 package. The old recdef "package" is still available as before, but
  3387 users are encouraged to use the new package.
  3388 
  3389 * Method "lexicographic_order" automatically synthesizes termination
  3390 relations as lexicographic combinations of size measures. 
  3391 
  3392 * Case-expressions allow arbitrary constructor-patterns (including
  3393 "_") and take their order into account, like in functional
  3394 programming.  Internally, this is translated into nested
  3395 case-expressions; missing cases are added and mapped to the predefined
  3396 constant "undefined". In complicated cases printing may no longer show
  3397 the original input but the internal form. Lambda-abstractions allow
  3398 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3399 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3400 variable.
  3401 
  3402 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3403 is an abbreviation for "of_nat :: nat => int". The simplification
  3404 rules for "of_nat" have been changed to work like "int" did
  3405 previously.  Potential INCOMPATIBILITY:
  3406   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3407   - of_nat_diff and of_nat_mult are no longer default simp rules
  3408 
  3409 * Method "algebra" solves polynomial equations over (semi)rings using
  3410 Groebner bases. The (semi)ring structure is defined by locales and the
  3411 tool setup depends on that generic context. Installing the method for
  3412 a specific type involves instantiating the locale and possibly adding
  3413 declarations for computation on the coefficients.  The method is
  3414 already instantiated for natural numbers and for the axiomatic class
  3415 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3416 CALCULEMUS 2007 for the general principles underlying this
  3417 architecture of context-aware proof-tools.
  3418 
  3419 * Method "ferrack" implements quantifier elimination over
  3420 special-purpose dense linear orders using locales (analogous to
  3421 "algebra"). The method is already installed for class
  3422 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3423 rat, etc.
  3424 
  3425 * Former constant "List.op @" now named "List.append".  Use ML
  3426 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3427 circumvent possible incompatibilities when working on ML level.
  3428 
  3429 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3430 
  3431 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3432 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3433 
  3434 * New syntax for Haskell-like list comprehension (input only), eg.
  3435 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3436 
  3437 * The special syntax for function "filter" has changed from [x :
  3438 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3439 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3440 
  3441 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3442 defined on nat only, as an abbreviation for [a..<Suc b]
  3443 INCOMPATIBILITY.
  3444 
  3445 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3446 
  3447 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3448 
  3449 * New lemma collection field_simps (an extension of ring_simps) for
  3450 manipulating (in)equations involving division. Multiplies with all
  3451 denominators that can be proved to be non-zero (in equations) or
  3452 positive/negative (in inequations).
  3453 
  3454 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3455 have been improved and renamed to ring_simps, group_simps and
  3456 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3457 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3458 
  3459 * Theory Library/Commutative_Ring: switched from recdef to function
  3460 package; constants add, mul, pow now curried.  Infix syntax for
  3461 algebraic operations.
  3462 
  3463 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3464 INCOMPATIBILITY.
  3465 
  3466 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3467 INCOMPATIBILITY.
  3468 
  3469 * HOL/records: generalised field-update to take a function on the
  3470 field rather than the new value: r(|A := x|) is translated to A_update
  3471 (K x) r The K-combinator that is internally used is called K_record.
  3472 INCOMPATIBILITY: Usage of the plain update functions has to be
  3473 adapted.
  3474  
  3475 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3476 * x = 0, which are required for a semiring.  Richer structures do not
  3477 inherit from semiring_0 anymore, because this property is a theorem
  3478 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3479 there is more to prove, but this is mostly trivial.
  3480 
  3481 * Class "recpower" is generalized to arbitrary monoids, not just
  3482 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3483 commutativity or semiring properties additionally.
  3484 
  3485 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3486 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3487 better use 'abbreviation'.
  3488 
  3489 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3490 
  3491 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3492 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3493 significant changes for setting up numeral syntax for types:
  3494   - New constants Numeral.pred and Numeral.succ instead
  3495       of former Numeral.bin_pred and Numeral.bin_succ.
  3496   - Use integer operations instead of bin_add, bin_mult and so on.
  3497   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3498   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3499 
  3500 See src/HOL/Integ/IntArith.thy for an example setup.
  3501 
  3502 * Command 'normal_form' computes the normal form of a term that may
  3503 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3504 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3505 heavy-duty computations because the functions are compiled to ML
  3506 first.  Correspondingly, a method "normalization" is provided.  See
  3507 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3508 
  3509 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3510 25 like -->); output depends on the "iff" print_mode, the default is
  3511 "A = B" (with priority 50).
  3512 
  3513 * Relations less (<) and less_eq (<=) are also available on type bool.
  3514 Modified syntax to disallow nesting without explicit parentheses,
  3515 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3516 INCOMPATIBILITY.
  3517 
  3518 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3519 
  3520 * Relation composition operator "op O" now has precedence 75 and binds
  3521 stronger than union and intersection. INCOMPATIBILITY.
  3522 
  3523 * The old set interval syntax "{m..n(}" (and relatives) has been
  3524 removed.  Use "{m..<n}" (and relatives) instead.
  3525 
  3526 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3527 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3528 ``declare [[simproc del: neq]]''.
  3529 
  3530 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3531 True/False.
  3532 
  3533 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3534 
  3535 * Theorem setsum_mult renamed to setsum_right_distrib.
  3536 
  3537 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3538 ``rule'' method.
  3539 
  3540 * Reimplemented methods "sat" and "satx", with several improvements:
  3541 goals no longer need to be stated as "<prems> ==> False", equivalences
  3542 (i.e. "=" on type bool) are handled, variable names of the form
  3543 "lit_<n>" are no longer reserved, significant speedup.
  3544 
  3545 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3546 zChaff is still supported as well.
  3547 
  3548 * 'inductive' and 'datatype': provide projections of mutual rules,
  3549 bundled as foo_bar.inducts;
  3550 
  3551 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3552 Library.
  3553 
  3554 * Library: moved theory Accessible_Part to main HOL.
  3555 
  3556 * Library: added theory Coinductive_List of potentially infinite lists
  3557 as greatest fixed-point.
  3558 
  3559 * Library: added theory AssocList which implements (finite) maps as
  3560 association lists.
  3561 
  3562 * Method "evaluation" solves goals (i.e. a boolean expression)
  3563 efficiently by compiling it to ML.  The goal is "proved" (via an
  3564 oracle) if it evaluates to True.
  3565 
  3566 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3567 also when invoked by the simplifier.  This results in the Simplifier
  3568 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3569 Configuration option fast_arith_split_limit=0 recovers the old
  3570 behavior.
  3571 
  3572 * Support for hex (0x20) and binary (0b1001) numerals.
  3573 
  3574 * New method: reify eqs (t), where eqs are equations for an
  3575 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3576 parameter, computes a term s::'b and a list xs::'a list and proves the
  3577 theorem I xs s = t. This is also known as reification or quoting. The
  3578 resulting theorem is applied to the subgoal to substitute t with I xs
  3579 s.  If t is omitted, the subgoal itself is reified.
  3580 
  3581 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3582 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3583 where f is supposed to be a computable function (in the sense of code
  3584 generattion). The method uses reify to compute s and xs as above then
  3585 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3586 r and finally gets the theorem t = r, which is again applied to the
  3587 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3588 
  3589 * Reflection: Automatic reification now handels binding, an example is
  3590 available in src/HOL/ex/ReflectionEx.thy
  3591 
  3592 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3593 command 'statespace' that is similar to 'record', but introduces an
  3594 abstract specification based on the locale infrastructure instead of
  3595 HOL types.  This leads to extra flexibility in composing state spaces,
  3596 in particular multiple inheritance and renaming of components.
  3597 
  3598 
  3599 *** HOL-Complex ***
  3600 
  3601 * Hyperreal: Functions root and sqrt are now defined on negative real
  3602 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3603 Nonnegativity side conditions have been removed from many lemmas, so
  3604 that more subgoals may now be solved by simplification; potential
  3605 INCOMPATIBILITY.
  3606 
  3607 * Real: new type classes formalize real normed vector spaces and
  3608 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3609 and norm :: 'a => real.
  3610 
  3611 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3612 reals into other types. The overloaded constant Reals :: 'a set is now
  3613 defined as range of_real; potential INCOMPATIBILITY.
  3614 
  3615 * Real: proper support for ML code generation, including 'quickcheck'.
  3616 Reals are implemented as arbitrary precision rationals.
  3617 
  3618 * Hyperreal: Several constants that previously worked only for the
  3619 reals have been generalized, so they now work over arbitrary vector
  3620 spaces. Type annotations may need to be added in some cases; potential
  3621 INCOMPATIBILITY.
  3622 
  3623   Infinitesimal  :: ('a::real_normed_vector) star set
  3624   HFinite        :: ('a::real_normed_vector) star set
  3625   HInfinite      :: ('a::real_normed_vector) star set
  3626   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3627   monad          :: ('a::real_normed_vector) star => 'a star set
  3628   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3629   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3630   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3631   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3632   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3633   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3634   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3635   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3636   sgn            :: 'a::real_normed_vector => 'a
  3637   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3638 
  3639 * Complex: Some complex-specific constants are now abbreviations for
  3640 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3641 hnorm.  Other constants have been entirely removed in favor of the
  3642 polymorphic versions (INCOMPATIBILITY):
  3643 
  3644   approx        <-- capprox
  3645   HFinite       <-- CFinite
  3646   HInfinite     <-- CInfinite
  3647   Infinitesimal <-- CInfinitesimal
  3648   monad         <-- cmonad
  3649   galaxy        <-- cgalaxy
  3650   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3651   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3652   (ns)deriv     <-- (ns)cderiv
  3653 
  3654 
  3655 *** HOL-Algebra ***
  3656 
  3657 * Formalisation of ideals and the quotient construction over rings.
  3658 
  3659 * Order and lattice theory no longer based on records.
  3660 INCOMPATIBILITY.
  3661 
  3662 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3663 greatest_closed.  INCOMPATIBILITY.
  3664 
  3665 * Method algebra is now set up via an attribute.  For examples see
  3666 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3667 of algebraic structures.
  3668 
  3669 * Renamed theory CRing to Ring.
  3670 
  3671 
  3672 *** HOL-Nominal ***
  3673 
  3674 * Substantial, yet incomplete support for nominal datatypes (binding
  3675 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3676 src/HOL/Nominal/Examples.  Prospective users should consult
  3677 http://isabelle.in.tum.de/nominal/
  3678 
  3679 
  3680 *** ML ***
  3681 
  3682 * ML basics: just one true type int, which coincides with IntInf.int
  3683 (even on SML/NJ).
  3684 
  3685 * ML within Isar: antiquotations allow to embed statically-checked
  3686 formal entities in the source, referring to the context available at
  3687 compile-time.  For example:
  3688 
  3689 ML {* @{sort "{zero,one}"} *}
  3690 ML {* @{typ "'a => 'b"} *}
  3691 ML {* @{term "%x. x"} *}
  3692 ML {* @{prop "x == y"} *}
  3693 ML {* @{ctyp "'a => 'b"} *}
  3694 ML {* @{cterm "%x. x"} *}
  3695 ML {* @{cprop "x == y"} *}
  3696 ML {* @{thm asm_rl} *}
  3697 ML {* @{thms asm_rl} *}
  3698 ML {* @{type_name c} *}
  3699 ML {* @{type_syntax c} *}
  3700 ML {* @{const_name c} *}
  3701 ML {* @{const_syntax c} *}
  3702 ML {* @{context} *}
  3703 ML {* @{theory} *}
  3704 ML {* @{theory Pure} *}
  3705 ML {* @{theory_ref} *}
  3706 ML {* @{theory_ref Pure} *}
  3707 ML {* @{simpset} *}
  3708 ML {* @{claset} *}
  3709 ML {* @{clasimpset} *}
  3710 
  3711 The same works for sources being ``used'' within an Isar context.
  3712 
  3713 * ML in Isar: improved error reporting; extra verbosity with
  3714 ML_Context.trace enabled.
  3715 
  3716 * Pure/General/table.ML: the join operations now works via exceptions
  3717 DUP/SAME instead of type option. This is simpler in simple cases, and
  3718 admits slightly more efficient complex applications.
  3719 
  3720 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3721 use Context.generic instead of just theory.
  3722 
  3723 * Pure: datatype Context.generic joins theory/Proof.context and
  3724 provides some facilities for code that works in either kind of
  3725 context, notably GenericDataFun for uniform theory and proof data.
  3726 
  3727 * Pure: simplified internal attribute type, which is now always
  3728 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3729 local (Proof.context) attributes have been discontinued, while
  3730 minimizing code duplication. Thm.rule_attribute and
  3731 Thm.declaration_attribute build canonical attributes; see also structure
  3732 Context for further operations on Context.generic, notably
  3733 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3734 declarations and definitions.
  3735 
  3736 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3737 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3738 init only required for impure data. INCOMPATIBILITY: empty really need
  3739 to be empty (no dependencies on theory content!)
  3740 
  3741 * Pure/kernel: consts certification ignores sort constraints given in
  3742 signature declarations. (This information is not relevant to the
  3743 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3744 potential INCOMPATIBILITY.
  3745 
  3746 * Pure: axiomatic type classes are now purely definitional, with
  3747 explicit proofs of class axioms and super class relations performed
  3748 internally. See Pure/axclass.ML for the main internal interfaces --
  3749 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3750 AxClass.axiomatize_class/classrel/arity supersede
  3751 Sign.add_classes/classrel/arities.
  3752 
  3753 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3754 global/local versions on theory vs. Proof.context have been
  3755 discontinued; Attrib.syntax and Method.syntax have been adapted
  3756 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3757 attributes, methods, etc.
  3758 
  3759 * Pure: several functions of signature "... -> theory -> theory * ..."
  3760 have been reoriented to "... -> theory -> ... * theory" in order to
  3761 allow natural usage in combination with the ||>, ||>>, |-> and
  3762 fold_map combinators.
  3763 
  3764 * Pure: official theorem names (closed derivations) and additional
  3765 comments (tags) are now strictly separate.  Name hints -- which are
  3766 maintained as tags -- may be attached any time without affecting the
  3767 derivation.
  3768 
  3769 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3770 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3771 achieve the old behaviour.
  3772 
  3773 * Pure: the "Goal" constant is now called "prop", supporting a
  3774 slightly more general idea of ``protecting'' meta-level rule
  3775 statements.
  3776 
  3777 * Pure: Logic.(un)varify only works in a global context, which is now
  3778 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3779 Logic.legacy_(un)varify as temporary workaround.
  3780 
  3781 * Pure: structure Name provides scalable operations for generating
  3782 internal variable names, notably Name.variants etc.  This replaces
  3783 some popular functions from term.ML:
  3784 
  3785   Term.variant		->  Name.variant
  3786   Term.variantlist	->  Name.variant_list
  3787   Term.invent_names	->  Name.invent_list
  3788 
  3789 Note that low-level renaming rarely occurs in new code -- operations
  3790 from structure Variable are used instead (see below).
  3791 
  3792 * Pure: structure Variable provides fundamental operations for proper
  3793 treatment of fixed/schematic variables in a context.  For example,
  3794 Variable.import introduces fixes for schematics of given facts and
  3795 Variable.export reverses the effect (up to renaming) -- this replaces
  3796 various freeze_thaw operations.
  3797 
  3798 * Pure: structure Goal provides simple interfaces for
  3799 init/conclude/finish and tactical prove operations (replacing former
  3800 Tactic.prove).  Goal.prove is the canonical way to prove results
  3801 within a given context; Goal.prove_global is a degraded version for
  3802 theory level goals, including a global Drule.standard.  Note that
  3803 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3804 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3805 in a locale context).
  3806 
  3807 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3808 and type checking (Syntax.check_term etc.), with common combinations
  3809 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3810 which are considered legacy and await removal.
  3811 
  3812 * Pure/Syntax: generic interfaces for type unchecking
  3813 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3814 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3815 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3816 available for convenience, but refer to the very same operations using
  3817 a mere theory instead of a full context.
  3818 
  3819 * Isar: simplified treatment of user-level errors, using exception
  3820 ERROR of string uniformly.  Function error now merely raises ERROR,
  3821 without any side effect on output channels.  The Isar toplevel takes
  3822 care of proper display of ERROR exceptions.  ML code may use plain
  3823 handle/can/try; cat_error may be used to concatenate errors like this:
  3824 
  3825   ... handle ERROR msg => cat_error msg "..."
  3826 
  3827 Toplevel ML code (run directly or through the Isar toplevel) may be
  3828 embedded into the Isar toplevel with exception display/debug like
  3829 this:
  3830 
  3831   Isar.toplevel (fn () => ...)
  3832 
  3833 INCOMPATIBILITY, removed special transform_error facilities, removed
  3834 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3835 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3836 -- use plain ERROR instead.
  3837 
  3838 * Isar: theory setup now has type (theory -> theory), instead of a
  3839 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3840 
  3841 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3842 ProofContext.debug/verbose flags.
  3843 
  3844 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3845 theory before entering a proof state.  Transactions now always see a
  3846 quasi-functional intermediate checkpoint, both in interactive and
  3847 batch mode.
  3848 
  3849 * Isar: simplified interfaces for outer syntax.  Renamed
  3850 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3851 OuterSyntax.add_parsers -- this functionality is now included in
  3852 OuterSyntax.command etc.  INCOMPATIBILITY.
  3853 
  3854 * Simplifier: the simpset of a running simplification process now
  3855 contains a proof context (cf. Simplifier.the_context), which is the
  3856 very context that the initial simpset has been retrieved from (by
  3857 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3858 (solver, looper etc.) may depend on arbitrary proof data.
  3859 
  3860 * Simplifier.inherit_context inherits the proof context (plus the
  3861 local bounds) of the current simplification process; any simproc
  3862 etc. that calls the Simplifier recursively should do this!  Removed
  3863 former Simplifier.inherit_bounds, which is already included here --
  3864 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3865 specify an explicit context using Simplifier.context/theory_context.
  3866 
  3867 * Simplifier/Classical Reasoner: more abstract interfaces
  3868 change_simpset/claset for modifying the simpset/claset reference of a
  3869 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3870 INCOMPATIBILITY.
  3871 
  3872 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3873 "Trueprop" etc.
  3874 
  3875 
  3876 *** System ***
  3877 
  3878 * settings: the default heap location within ISABELLE_HOME_USER now
  3879 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3880 Isabelle installations.
  3881 
  3882 * isabelle-process: option -S (secure mode) disables some critical
  3883 operations, notably runtime compilation and evaluation of ML source
  3884 code.
  3885 
  3886 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3887 
  3888 * Support for parallel execution, using native multicore support of
  3889 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3890 independent theories, according to the given theory header
  3891 specifications. The maximum number of worker threads is specified via
  3892 usedir option -M or the "max-threads" setting in Proof General. A
  3893 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3894 to 6 on a 8-core machine.  User-code needs to observe certain
  3895 guidelines for thread-safe programming, see appendix A in the Isar
  3896 Implementation manual.
  3897 
  3898 
  3899 
  3900 New in Isabelle2005 (October 2005)
  3901 ----------------------------------
  3902 
  3903 *** General ***
  3904 
  3905 * Theory headers: the new header syntax for Isar theories is
  3906 
  3907   theory <name>
  3908   imports <theory1> ... <theoryN>
  3909   uses <file1> ... <fileM>
  3910   begin
  3911 
  3912 where the 'uses' part is optional.  The previous syntax
  3913 
  3914   theory <name> = <theory1> + ... + <theoryN>:
  3915 
  3916 will disappear in the next release.  Use isatool fixheaders to convert
  3917 existing theory files.  Note that there is no change in ancient
  3918 non-Isar theories now, but these will disappear soon.
  3919 
  3920 * Theory loader: parent theories can now also be referred to via
  3921 relative and absolute paths.
  3922 
  3923 * Command 'find_theorems' searches for a list of criteria instead of a
  3924 list of constants. Known criteria are: intro, elim, dest, name:string,
  3925 simp:term, and any term. Criteria can be preceded by '-' to select
  3926 theorems that do not match. Intro, elim, dest select theorems that
  3927 match the current goal, name:s selects theorems whose fully qualified
  3928 name contain s, and simp:term selects all simplification rules whose
  3929 lhs match term.  Any other term is interpreted as pattern and selects
  3930 all theorems matching the pattern. Available in ProofGeneral under
  3931 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3932 
  3933   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3934 
  3935 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3936 matching the current goal as introduction rule and not having "HOL."
  3937 in their name (i.e. not being defined in theory HOL).
  3938 
  3939 * Command 'thms_containing' has been discontinued in favour of
  3940 'find_theorems'; INCOMPATIBILITY.
  3941 
  3942 * Communication with Proof General is now 8bit clean, which means that
  3943 Unicode text in UTF-8 encoding may be used within theory texts (both
  3944 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3945 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3946 
  3947   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3948   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3949 
  3950 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3951 Classical Reasoner.  Typical big applications run around 2 times
  3952 faster.
  3953 
  3954 
  3955 *** Document preparation ***
  3956 
  3957 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3958 of raw sources.  Only those symbols that do not require additional
  3959 LaTeX packages (depending on comments in isabellesym.sty) are
  3960 displayed properly, everything else is left verbatim.  isatool display
  3961 and isatool print are used as front ends (these are subject to the
  3962 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3963 
  3964 * Command tags control specific markup of certain regions of text,
  3965 notably folding and hiding.  Predefined tags include "theory" (for
  3966 theory begin and end), "proof" for proof commands, and "ML" for
  3967 commands involving ML code; the additional tags "visible" and
  3968 "invisible" are unused by default.  Users may give explicit tag
  3969 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3970 interpretation of tags is determined by the LaTeX job during document
  3971 preparation: see option -V of isatool usedir, or options -n and -t of
  3972 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3973 \isadroptag.
  3974 
  3975 Several document versions may be produced at the same time via isatool
  3976 usedir (the generated index.html will link all of them).  Typical
  3977 specifications include ''-V document=theory,proof,ML'' to present
  3978 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3979 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3980 these parts without any formal replacement text.  The Isabelle site
  3981 default settings produce ''document'' and ''outline'' versions as
  3982 specified above.
  3983 
  3984 * Several new antiquotations:
  3985 
  3986   @{term_type term} prints a term with its type annotated;
  3987 
  3988   @{typeof term} prints the type of a term;
  3989 
  3990   @{const const} is the same as @{term const}, but checks that the
  3991   argument is a known logical constant;
  3992 
  3993   @{term_style style term} and @{thm_style style thm} print a term or
  3994   theorem applying a "style" to it
  3995 
  3996   @{ML text}
  3997 
  3998 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3999 definitions, equations, inequations etc., 'concl' printing only the
  4000 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4001 to print the specified premise.  TermStyle.add_style provides an ML
  4002 interface for introducing further styles.  See also the "LaTeX Sugar"
  4003 document practical applications.  The ML antiquotation prints
  4004 type-checked ML expressions verbatim.
  4005 
  4006 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4007 and 'text' support optional locale specification '(in loc)', which
  4008 specifies the default context for interpreting antiquotations.  For
  4009 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4010 
  4011 * Option 'locale=NAME' of antiquotations specifies an alternative
  4012 context interpreting the subsequent argument.  For example: @{thm
  4013 [locale=lattice] inf_assoc}.
  4014 
  4015 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4016 a proof context.
  4017 
  4018 * Proper output of antiquotations for theory commands involving a
  4019 proof context (such as 'locale' or 'theorem (in loc) ...').
  4020 
  4021 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4022 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4023 
  4024 * isatool usedir: new option -C (default true) controls whether option
  4025 -D should include a copy of the original document directory; -C false
  4026 prevents unwanted effects such as copying of administrative CVS data.
  4027 
  4028 
  4029 *** Pure ***
  4030 
  4031 * Considerably improved version of 'constdefs' command.  Now performs
  4032 automatic type-inference of declared constants; additional support for
  4033 local structure declarations (cf. locales and HOL records), see also
  4034 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4035 sequential dependencies of definitions within a single 'constdefs'
  4036 section; moreover, the declared name needs to be an identifier.  If
  4037 all fails, consider to fall back on 'consts' and 'defs' separately.
  4038 
  4039 * Improved indexed syntax and implicit structures.  First of all,
  4040 indexed syntax provides a notational device for subscripted
  4041 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4042 expressions.  Secondly, in a local context with structure
  4043 declarations, number indexes \<^sub>n or the empty index (default
  4044 number 1) refer to a certain fixed variable implicitly; option
  4045 show_structs controls printing of implicit structures.  Typical
  4046 applications of these concepts involve record types and locales.
  4047 
  4048 * New command 'no_syntax' removes grammar declarations (and
  4049 translations) resulting from the given syntax specification, which is
  4050 interpreted in the same manner as for the 'syntax' command.
  4051 
  4052 * 'Advanced' translation functions (parse_translation etc.) may depend
  4053 on the signature of the theory context being presently used for
  4054 parsing/printing, see also isar-ref manual.
  4055 
  4056 * Improved 'oracle' command provides a type-safe interface to turn an
  4057 ML expression of type theory -> T -> term into a primitive rule of
  4058 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4059 is already included here); see also FOL/ex/IffExample.thy;
  4060 INCOMPATIBILITY.
  4061 
  4062 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4063 before); "cI" is no longer bound, use "c.intro" instead.
  4064 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4065 axclasses vs. locales.
  4066 
  4067 * Improved internal renaming of symbolic identifiers -- attach primes
  4068 instead of base 26 numbers.
  4069 
  4070 * New flag show_question_marks controls printing of leading question
  4071 marks in schematic variable names.
  4072 
  4073 * In schematic variable names, *any* symbol following \<^isub> or
  4074 \<^isup> is now treated as part of the base name.  For example, the
  4075 following works without printing of awkward ".0" indexes:
  4076 
  4077   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4078     by simp
  4079 
  4080 * Inner syntax includes (*(*nested*) comments*).
  4081 
  4082 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4083 annotations as "(00...)".
  4084 
  4085 * Clear separation of logical types and nonterminals, where the latter
  4086 may only occur in 'syntax' specifications or type abbreviations.
  4087 Before that distinction was only partially implemented via type class
  4088 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4089 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4090 exotic syntax specifications may require further adaption
  4091 (e.g. Cube/Cube.thy).
  4092 
  4093 * Removed obsolete type class "logic", use the top sort {} instead.
  4094 Note that non-logical types should be declared as 'nonterminals'
  4095 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4096 specifications.
  4097 
  4098 * Attributes 'induct' and 'cases': type or set names may now be
  4099 locally fixed variables as well.
  4100 
  4101 * Simplifier: can now control the depth to which conditional rewriting
  4102 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4103 Limit.
  4104 
  4105 * Simplifier: simplification procedures may now take the current
  4106 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4107 interface), which is very useful for calling the Simplifier
  4108 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4109 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4110 low-level mk_simproc no longer applies Logic.varify internally, to
  4111 allow for use in a context of fixed variables.
  4112 
  4113 * thin_tac now works even if the assumption being deleted contains !!
  4114 or ==>.  More generally, erule now works even if the major premise of
  4115 the elimination rule contains !! or ==>.
  4116 
  4117 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4118 
  4119 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4120 from Pure, which contains all common declarations already.  Both
  4121 theories are defined via plain Isabelle/Isar .thy files.
  4122 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4123 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4124 use isatool fixcpure to adapt your theory and ML sources.
  4125 
  4126 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4127 selections of theorems in named facts via index ranges.
  4128 
  4129 * 'print_theorems': in theory mode, really print the difference
  4130 wrt. the last state (works for interactive theory development only),
  4131 in proof mode print all local facts (cf. 'print_facts');
  4132 
  4133 * 'hide': option '(open)' hides only base names.
  4134 
  4135 * More efficient treatment of intermediate checkpoints in interactive
  4136 theory development.
  4137 
  4138 * Code generator is now invoked via code_module (incremental code
  4139 generation) and code_library (modular code generation, ML structures
  4140 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4141 must be quoted when used as identifiers.
  4142 
  4143 * New 'value' command for reading, evaluating and printing terms using
  4144 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4145 quoted when used as identifier.
  4146 
  4147 
  4148 *** Locales ***
  4149 
  4150 * New commands for the interpretation of locale expressions in
  4151 theories (1), locales (2) and proof contexts (3).  These generate
  4152 proof obligations from the expression specification.  After the
  4153 obligations have been discharged, theorems of the expression are added
  4154 to the theory, target locale or proof context.  The synopsis of the
  4155 commands is a follows:
  4156 
  4157   (1) interpretation expr inst
  4158   (2) interpretation target < expr
  4159   (3) interpret expr inst
  4160 
  4161 Interpretation in theories and proof contexts require a parameter
  4162 instantiation of terms from the current context.  This is applied to
  4163 specifications and theorems of the interpreted expression.
  4164 Interpretation in locales only permits parameter renaming through the
  4165 locale expression.  Interpretation is smart in that interpretations
  4166 that are active already do not occur in proof obligations, neither are
  4167 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4168 inspect active interpretations of a particular locale.  For details,
  4169 see the Isar Reference manual.  Examples can be found in
  4170 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4171 
  4172 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4173 'interpret' instead.
  4174 
  4175 * New context element 'constrains' for adding type constraints to
  4176 parameters.
  4177 
  4178 * Context expressions: renaming of parameters with syntax
  4179 redeclaration.
  4180 
  4181 * Locale declaration: 'includes' disallowed.
  4182 
  4183 * Proper static binding of attribute syntax -- i.e. types / terms /
  4184 facts mentioned as arguments are always those of the locale definition
  4185 context, independently of the context of later invocations.  Moreover,
  4186 locale operations (renaming and type / term instantiation) are applied
  4187 to attribute arguments as expected.
  4188 
  4189 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4190 actual attributes; rare situations may require Attrib.attribute to
  4191 embed those attributes into Attrib.src that lack concrete syntax.
  4192 Attribute implementations need to cooperate properly with the static
  4193 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4194 Attrib.XXX_thm etc. already do the right thing without further
  4195 intervention.  Only unusual applications -- such as "where" or "of"
  4196 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4197 on the context and the facts involved -- may have to assign parsed
  4198 values to argument tokens explicitly.
  4199 
  4200 * Changed parameter management in theorem generation for long goal
  4201 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4202 theorem statement in rare situations.
  4203 
  4204 * Locale inspection command 'print_locale' omits notes elements.  Use
  4205 'print_locale!' to have them included in the output.
  4206 
  4207 
  4208 *** Provers ***
  4209 
  4210 * Provers/hypsubst.ML: improved version of the subst method, for
  4211 single-step rewriting: it now works in bound variable contexts. New is
  4212 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4213 rewrite a different subterm than the original subst method, which is
  4214 still available as 'simplesubst'.
  4215 
  4216 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4217 and quasi orders.
  4218 
  4219 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4220 reflexive-transitive closure of relations.
  4221 
  4222 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4223 limit (previously hard-coded with a value of 20) user-definable.
  4224 
  4225 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4226 is peformed already.  Object-logics merely need to finish their
  4227 initial simpset configuration as before.  INCOMPATIBILITY.
  4228 
  4229 
  4230 *** HOL ***
  4231 
  4232 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4233 
  4234   syntax (epsilon)
  4235     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4236 
  4237 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4238 and x-symbol; use option '-m epsilon' to get it actually printed.
  4239 Moreover, the mathematically important symbolic identifier \<epsilon>
  4240 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4241 
  4242 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4243 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4244 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4245 support corresponding Isar calculations.
  4246 
  4247 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4248 instead of ":".
  4249 
  4250 * theory SetInterval: changed the syntax for open intervals:
  4251 
  4252   Old       New
  4253   {..n(}    {..<n}
  4254   {)n..}    {n<..}
  4255   {m..n(}   {m..<n}
  4256   {)m..n}   {m<..n}
  4257   {)m..n(}  {m<..<n}
  4258 
  4259 The old syntax is still supported but will disappear in the next
  4260 release.  For conversion use the following Emacs search and replace
  4261 patterns (these are not perfect but work quite well):
  4262 
  4263   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4264   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4265 
  4266 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4267 equalities in commutative rings; method 'algebra' provides a generic
  4268 interface.
  4269 
  4270 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4271 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4272 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4273 be a tuple pattern.
  4274 
  4275 Some new syntax forms are available:
  4276 
  4277   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4278   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4279   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4280   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4281 
  4282 The latter form "\<Sum>x < k. e" used to be based on a separate
  4283 function "Summation", which has been discontinued.
  4284 
  4285 * theory Finite_Set: in structured induction proofs, the insert case
  4286 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4287 (insert F x)'.
  4288 
  4289 * The 'refute' command has been extended to support a much larger
  4290 fragment of HOL, including axiomatic type classes, constdefs and
  4291 typedefs, inductive datatypes and recursion.
  4292 
  4293 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4294 Requires zChaff with proof generation to be installed.  See
  4295 HOL/ex/SAT_Examples.thy for examples.
  4296 
  4297 * Datatype induction via method 'induct' now preserves the name of the
  4298 induction variable. For example, when proving P(xs::'a list) by
  4299 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4300 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4301 in unstructured proof scripts.
  4302 
  4303 * Reworked implementation of records.  Improved scalability for
  4304 records with many fields, avoiding performance problems for type
  4305 inference. Records are no longer composed of nested field types, but
  4306 of nested extension types. Therefore the record type only grows linear
  4307 in the number of extensions and not in the number of fields.  The
  4308 top-level (users) view on records is preserved.  Potential
  4309 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4310 old record representation. The type generated for a record is called
  4311 <record_name>_ext_type.
  4312 
  4313 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4314 proofs triggered by a record definition or a simproc (if
  4315 quick_and_dirty is enabled).  Definitions of large records can take
  4316 quite long.
  4317 
  4318 New simproc record_upd_simproc for simplification of multiple record
  4319 updates enabled by default.  Moreover, trivial updates are also
  4320 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4321 occasionally, since simplification is more powerful by default.
  4322 
  4323 * typedef: proper support for polymorphic sets, which contain extra
  4324 type-variables in the term.
  4325 
  4326 * Simplifier: automatically reasons about transitivity chains
  4327 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4328 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4329 old proofs break occasionally as simplification may now solve more
  4330 goals than previously.
  4331 
  4332 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4333 present.  Works for all partial orders (class "order"), in particular
  4334 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4335 just like y <= x.
  4336 
  4337 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4338 bound variable or a constant then the let is unfolded.  Otherwise
  4339 first a is simplified to b, and then f b is simplified to g. If
  4340 possible we abstract b from g arriving at "let x = b in h x",
  4341 otherwise we unfold the let and arrive at g.  The simproc can be
  4342 enabled/disabled by the reference use_let_simproc.  Potential
  4343 INCOMPATIBILITY since simplification is more powerful by default.
  4344 
  4345 * Classical reasoning: the meson method now accepts theorems as arguments.
  4346 
  4347 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4348 jobs to provide advice on the provability of subgoals.
  4349 
  4350 * Theory OrderedGroup and Ring_and_Field: various additions and
  4351 improvements to faciliate calculations involving equalities and
  4352 inequalities.
  4353 
  4354 The following theorems have been eliminated or modified
  4355 (INCOMPATIBILITY):
  4356 
  4357   abs_eq             now named abs_of_nonneg
  4358   abs_of_ge_0        now named abs_of_nonneg
  4359   abs_minus_eq       now named abs_of_nonpos
  4360   imp_abs_id         now named abs_of_nonneg
  4361   imp_abs_neg_id     now named abs_of_nonpos
  4362   mult_pos           now named mult_pos_pos
  4363   mult_pos_le        now named mult_nonneg_nonneg
  4364   mult_pos_neg_le    now named mult_nonneg_nonpos
  4365   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4366   mult_neg           now named mult_neg_neg
  4367   mult_neg_le        now named mult_nonpos_nonpos
  4368 
  4369 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4370      
  4371      zero_le_square
  4372      not_square_less_zero 
  4373 
  4374   The following lemmas have been deleted from Real/RealPow:
  4375   
  4376      realpow_zero_zero
  4377      realpow_two
  4378      realpow_less
  4379      zero_le_power
  4380      realpow_two_le
  4381      abs_realpow_two
  4382      realpow_two_abs     
  4383 
  4384 * Theory Parity: added rules for simplifying exponents.
  4385 
  4386 * Theory List:
  4387 
  4388 The following theorems have been eliminated or modified
  4389 (INCOMPATIBILITY):
  4390 
  4391   list_all_Nil       now named list_all.simps(1)
  4392   list_all_Cons      now named list_all.simps(2)
  4393   list_all_conv      now named list_all_iff
  4394   set_mem_eq         now named mem_iff
  4395 
  4396 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4397 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4398 
  4399 
  4400 *** HOL-Complex ***
  4401 
  4402 * Theory RealDef: better support for embedding natural numbers and
  4403 integers in the reals.
  4404 
  4405 The following theorems have been eliminated or modified
  4406 (INCOMPATIBILITY):
  4407 
  4408   exp_ge_add_one_self  now requires no hypotheses
  4409   real_of_int_add      reversed direction of equality (use [symmetric])
  4410   real_of_int_minus    reversed direction of equality (use [symmetric])
  4411   real_of_int_diff     reversed direction of equality (use [symmetric])
  4412   real_of_int_mult     reversed direction of equality (use [symmetric])
  4413 
  4414 * Theory RComplete: expanded support for floor and ceiling functions.
  4415 
  4416 * Theory Ln is new, with properties of the natural logarithm
  4417 
  4418 * Hyperreal: There is a new type constructor "star" for making
  4419 nonstandard types.  The old type names are now type synonyms:
  4420 
  4421   hypreal = real star
  4422   hypnat = nat star
  4423   hcomplex = complex star
  4424 
  4425 * Hyperreal: Many groups of similarly-defined constants have been
  4426 replaced by polymorphic versions (INCOMPATIBILITY):
  4427 
  4428   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4429 
  4430   starset      <-- starsetNat, starsetC
  4431   *s*          <-- *sNat*, *sc*
  4432   starset_n    <-- starsetNat_n, starsetC_n
  4433   *sn*         <-- *sNatn*, *scn*
  4434   InternalSets <-- InternalNatSets, InternalCSets
  4435 
  4436   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4437   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4438   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4439   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4440   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4441 
  4442 * Hyperreal: Many type-specific theorems have been removed in favor of
  4443 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4444 
  4445   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4446   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4447   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4448   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4449   right_minus <-- hypreal_add_minus
  4450   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4451   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4452   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4453   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4454   mult_1_right <-- hcomplex_mult_one_right
  4455   mult_zero_left <-- hcomplex_mult_zero_left
  4456   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4457   right_distrib <-- hypnat_add_mult_distrib2
  4458   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4459   right_inverse <-- hypreal_mult_inverse
  4460   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4461   order_refl <-- {hypreal,hypnat}_le_refl
  4462   order_trans <-- {hypreal,hypnat}_le_trans
  4463   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4464   order_less_le <-- {hypreal,hypnat}_less_le
  4465   linorder_linear <-- {hypreal,hypnat}_le_linear
  4466   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4467   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4468   add_nonneg_nonneg <-- hypreal_le_add_order
  4469 
  4470 * Hyperreal: Separate theorems having to do with type-specific
  4471 versions of constants have been merged into theorems that apply to the
  4472 new polymorphic constants (INCOMPATIBILITY):
  4473 
  4474   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4475   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4476   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4477   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4478   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4479   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4480   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4481   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4482   STAR_diff <-- {STAR,STARC}_diff
  4483   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4484     STARC_hcomplex_of_complex}_image_subset
  4485   starset_n_Un <-- starset{Nat,C}_n_Un
  4486   starset_n_Int <-- starset{Nat,C}_n_Int
  4487   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4488   starset_n_diff <-- starset{Nat,C}_n_diff
  4489   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4490   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4491   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4492   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4493   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4494   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4495   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4496   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4497   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4498   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4499   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4500   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4501   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4502   starfun_diff <-- starfun{C,RC,CR}_diff
  4503   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4504   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4505   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4506   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4507   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4508   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4509   starfun_Id <-- starfunC_Id
  4510   starfun_approx <-- starfun{Nat,CR}_approx
  4511   starfun_capprox <-- starfun{C,RC}_capprox
  4512   starfun_abs <-- starfunNat_rabs
  4513   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4514   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4515   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4516   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4517   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4518   starfun_add_approx <-- starfunCR_add_approx
  4519   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4520   starfun_divide <-- starfun{C,CR,RC}_divide
  4521   starfun_n <-- starfun{Nat,C}_n
  4522   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4523   starfun_n_add <-- starfun{Nat,C}_n_add
  4524   starfun_n_add_minus <-- starfunNat_n_add_minus
  4525   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4526   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4527   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4528 
  4529   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4530   star_n_minus <-- {hypreal,hcomplex}_minus
  4531   star_n_diff <-- {hypreal,hcomplex}_diff
  4532   star_n_mult <-- {hypreal,hcomplex}_mult
  4533   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4534   star_n_le <-- {hypreal,hypnat}_le
  4535   star_n_less <-- {hypreal,hypnat}_less
  4536   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4537   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4538   star_n_abs <-- hypreal_hrabs
  4539   star_n_divide <-- hcomplex_divide
  4540 
  4541   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4542   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4543   star_of_diff <-- hypreal_of_real_diff
  4544   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4545   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4546   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4547   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4548   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4549   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4550   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4551   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4552   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4553   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4554   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4555   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4556   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4557   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4558   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4559   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4560   star_of_power <-- hypreal_of_real_power
  4561   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4562 
  4563 * Hyperreal: new method "transfer" that implements the transfer
  4564 principle of nonstandard analysis. With a subgoal that mentions
  4565 nonstandard types like "'a star", the command "apply transfer"
  4566 replaces it with an equivalent one that mentions only standard types.
  4567 To be successful, all free variables must have standard types; non-
  4568 standard variables must have explicit universal quantifiers.
  4569 
  4570 * Hyperreal: A theory of Taylor series.
  4571 
  4572 
  4573 *** HOLCF ***
  4574 
  4575 * Discontinued special version of 'constdefs' (which used to support
  4576 continuous functions) in favor of the general Pure one with full
  4577 type-inference.
  4578 
  4579 * New simplification procedure for solving continuity conditions; it
  4580 is much faster on terms with many nested lambda abstractions (cubic
  4581 instead of exponential time).
  4582 
  4583 * New syntax for domain package: selector names are now optional.
  4584 Parentheses should be omitted unless argument is lazy, for example:
  4585 
  4586   domain 'a stream = cons "'a" (lazy "'a stream")
  4587 
  4588 * New command 'fixrec' for defining recursive functions with pattern
  4589 matching; defining multiple functions with mutual recursion is also
  4590 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4591 sinr, or any data constructor defined by the domain package. The given
  4592 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4593 syntax and examples.
  4594 
  4595 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4596 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4597 but the proof obligation additionally includes an admissibility
  4598 requirement. The packages generate instances of class cpo or pcpo,
  4599 with continuity and strictness theorems for Rep and Abs.
  4600 
  4601 * HOLCF: Many theorems have been renamed according to a more standard naming
  4602 scheme (INCOMPATIBILITY):
  4603 
  4604   foo_inject:  "foo$x = foo$y ==> x = y"
  4605   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4606   foo_less:    "(foo$x << foo$y) = (x << y)"
  4607   foo_strict:  "foo$UU = UU"
  4608   foo_defined: "... ==> foo$x ~= UU"
  4609   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4610 
  4611 
  4612 *** ZF ***
  4613 
  4614 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4615 including the First Isomorphism Theorem (on quotienting by the kernel
  4616 of a homomorphism).
  4617 
  4618 * ZF/Simplifier: install second copy of type solver that actually
  4619 makes use of TC rules declared to Isar proof contexts (or locales);
  4620 the old version is still required for ML proof scripts.
  4621 
  4622 
  4623 *** Cube ***
  4624 
  4625 * Converted to Isar theory format; use locales instead of axiomatic
  4626 theories.
  4627 
  4628 
  4629 *** ML ***
  4630 
  4631 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4632 for ||>, ||>>, |>>,
  4633 
  4634 * Pure/library.ML no longer defines its own option datatype, but uses
  4635 that of the SML basis, which has constructors NONE and SOME instead of
  4636 None and Some, as well as exception Option.Option instead of OPTION.
  4637 The functions the, if_none, is_some, is_none have been adapted
  4638 accordingly, while Option.map replaces apsome.
  4639 
  4640 * Pure/library.ML: the exception LIST has been given up in favour of
  4641 the standard exceptions Empty and Subscript, as well as
  4642 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4643 superceded by the standard hd and tl functions etc.
  4644 
  4645 A number of basic list functions are no longer exported to the ML
  4646 toplevel, as they are variants of predefined functions.  The following
  4647 suggests how one can translate existing code:
  4648 
  4649     rev_append xs ys = List.revAppend (xs, ys)
  4650     nth_elem (i, xs) = List.nth (xs, i)
  4651     last_elem xs = List.last xs
  4652     flat xss = List.concat xss
  4653     seq fs = List.app fs
  4654     partition P xs = List.partition P xs
  4655     mapfilter f xs = List.mapPartial f xs
  4656 
  4657 * Pure/library.ML: several combinators for linear functional
  4658 transformations, notably reverse application and composition:
  4659 
  4660   x |> f                f #> g
  4661   (x, y) |-> f          f #-> g
  4662 
  4663 * Pure/library.ML: introduced/changed precedence of infix operators:
  4664 
  4665   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4666   infix 2 ?;
  4667   infix 3 o oo ooo oooo;
  4668   infix 4 ~~ upto downto;
  4669 
  4670 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4671 infix operators.
  4672 
  4673 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4674 fold_map support linear functional transformations and nesting.  For
  4675 example:
  4676 
  4677   fold f [x1, ..., xN] y =
  4678     y |> f x1 |> ... |> f xN
  4679 
  4680   (fold o fold) f [xs1, ..., xsN] y =
  4681     y |> fold f xs1 |> ... |> fold f xsN
  4682 
  4683   fold f [x1, ..., xN] =
  4684     f x1 #> ... #> f xN
  4685 
  4686   (fold o fold) f [xs1, ..., xsN] =
  4687     fold f xs1 #> ... #> fold f xsN
  4688 
  4689 * Pure/library.ML: the following selectors on type 'a option are
  4690 available:
  4691 
  4692   the:               'a option -> 'a  (*partial*)
  4693   these:             'a option -> 'a  where 'a = 'b list
  4694   the_default: 'a -> 'a option -> 'a
  4695   the_list:          'a option -> 'a list
  4696 
  4697 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4698 basic operations for association lists, following natural argument
  4699 order; moreover the explicit equality predicate passed here avoids
  4700 potentially expensive polymorphic runtime equality checks.
  4701 The old functions may be expressed as follows:
  4702 
  4703   assoc = uncurry (AList.lookup (op =))
  4704   assocs = these oo AList.lookup (op =)
  4705   overwrite = uncurry (AList.update (op =)) o swap
  4706 
  4707 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4708 
  4709   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4710   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4711 
  4712 replacing make_keylist and keyfilter (occassionally used)
  4713 Naive rewrites:
  4714 
  4715   make_keylist = AList.make
  4716   keyfilter = AList.find (op =)
  4717 
  4718 * eq_fst and eq_snd now take explicit equality parameter, thus
  4719   avoiding eqtypes. Naive rewrites:
  4720 
  4721     eq_fst = eq_fst (op =)
  4722     eq_snd = eq_snd (op =)
  4723 
  4724 * Removed deprecated apl and apr (rarely used).
  4725   Naive rewrites:
  4726 
  4727     apl (n, op) =>>= curry op n
  4728     apr (op, m) =>>= fn n => op (n, m)
  4729 
  4730 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4731 provides a reasonably efficient light-weight implementation of sets as
  4732 lists.
  4733 
  4734 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4735 few new operations; existing lookup and update are now curried to
  4736 follow natural argument order (for use with fold etc.);
  4737 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4738 
  4739 * Pure/General: output via the Isabelle channels of
  4740 writeln/warning/error etc. is now passed through Output.output, with a
  4741 hook for arbitrary transformations depending on the print_mode
  4742 (cf. Output.add_mode -- the first active mode that provides a output
  4743 function wins).  Already formatted output may be embedded into further
  4744 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4745 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4746 accommodate easy composition of diagnostic messages etc.  Programmers
  4747 rarely need to care about Output.output or Output.raw at all, with
  4748 some notable exceptions: Output.output is required when bypassing the
  4749 standard channels (writeln etc.), or in token translations to produce
  4750 properly formatted results; Output.raw is required when capturing
  4751 already output material that will eventually be presented to the user
  4752 a second time.  For the default print mode, both Output.output and
  4753 Output.raw have no effect.
  4754 
  4755 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4756 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4757 cumulative results are displayed at the end of a batch session.
  4758 
  4759 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4760 replaced by File.platform_path and File.shell_path (with appropriate
  4761 hooks).  This provides a clean interface for unusual systems where the
  4762 internal and external process view of file names are different.
  4763 
  4764 * Pure: more efficient orders for basic syntactic entities: added
  4765 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4766 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4767 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4768 orders now -- potential INCOMPATIBILITY for code that depends on a
  4769 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4770 Library.sort_strings on result).
  4771 
  4772 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4773 fold_types traverse types/terms from left to right, observing natural
  4774 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4775 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4776 
  4777 * Pure: name spaces have been refined, with significant changes of the
  4778 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4779 to extern(_table).  The plain name entry path is superceded by a
  4780 general 'naming' context, which also includes the 'policy' to produce
  4781 a fully qualified name and external accesses of a fully qualified
  4782 name; NameSpace.extend is superceded by context dependent
  4783 Sign.declare_name.  Several theory and proof context operations modify
  4784 the naming context.  Especially note Theory.restore_naming and
  4785 ProofContext.restore_naming to get back to a sane state; note that
  4786 Theory.add_path is no longer sufficient to recover from
  4787 Theory.absolute_path in particular.
  4788 
  4789 * Pure: new flags short_names (default false) and unique_names
  4790 (default true) for controlling output of qualified names.  If
  4791 short_names is set, names are printed unqualified.  If unique_names is
  4792 reset, the name prefix is reduced to the minimum required to achieve
  4793 the original result when interning again, even if there is an overlap
  4794 with earlier declarations.
  4795 
  4796 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4797 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4798 (useful for printing error messages).  INCOMPATIBILITY.
  4799 
  4800 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4801 Theory.theory are now identified, referring to the universal
  4802 Context.theory (see Pure/context.ML).  Actual signature and theory
  4803 content is managed as theory data.  The old code and interfaces were
  4804 spread over many files and structures; the new arrangement introduces
  4805 considerable INCOMPATIBILITY to gain more clarity:
  4806 
  4807   Context -- theory management operations (name, identity, inclusion,
  4808     parents, ancestors, merge, etc.), plus generic theory data;
  4809 
  4810   Sign -- logical signature and syntax operations (declaring consts,
  4811     types, etc.), plus certify/read for common entities;
  4812 
  4813   Theory -- logical theory operations (stating axioms, definitions,
  4814     oracles), plus a copy of logical signature operations (consts,
  4815     types, etc.); also a few basic management operations (Theory.copy,
  4816     Theory.merge, etc.)
  4817 
  4818 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4819 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4820 for convenience -- they merely return the theory.
  4821 
  4822 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4823 
  4824 * Pure: the Isar proof context type is already defined early in Pure
  4825 as Context.proof (note that ProofContext.context and Proof.context are
  4826 aliases, where the latter is the preferred name).  This enables other
  4827 Isabelle components to refer to that type even before Isar is present.
  4828 
  4829 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4830 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4831 any of these kinds.  For example, Sign.intern typeK is now
  4832 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4833 Theory.hide_types.  Also note that former
  4834 Theory.hide_classes/types/consts are now
  4835 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4836 internalize their arguments!  INCOMPATIBILITY.
  4837 
  4838 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4839 datatype thmref (with constructors Name and NameSelection) instead of
  4840 plain string -- INCOMPATIBILITY;
  4841 
  4842 * Pure: cases produced by proof methods specify options, where NONE
  4843 means to remove case bindings -- INCOMPATIBILITY in
  4844 (RAW_)METHOD_CASES.
  4845 
  4846 * Pure: the following operations retrieve axioms or theorems from a
  4847 theory node or theory hierarchy, respectively:
  4848 
  4849   Theory.axioms_of: theory -> (string * term) list
  4850   Theory.all_axioms_of: theory -> (string * term) list
  4851   PureThy.thms_of: theory -> (string * thm) list
  4852   PureThy.all_thms_of: theory -> (string * thm) list
  4853 
  4854 * Pure: print_tac now outputs the goal through the trace channel.
  4855 
  4856 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4857 Reference Toplevel.debug (default false) controls detailed printing
  4858 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4859 controls execution profiling -- set to 1 for time and 2 for space
  4860 (both increase the runtime).
  4861 
  4862 * Isar session: The initial use of ROOT.ML is now always timed,
  4863 i.e. the log will show the actual process times, in contrast to the
  4864 elapsed wall-clock time that the outer shell wrapper produces.
  4865 
  4866 * Simplifier: improved handling of bound variables (nameless
  4867 representation, avoid allocating new strings).  Simprocs that invoke
  4868 the Simplifier recursively should use Simplifier.inherit_bounds to
  4869 avoid local name clashes.  Failure to do so produces warnings
  4870 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4871 for further details.
  4872 
  4873 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4874 bindings for all theorems stored within a given theory; this may help
  4875 in porting non-Isar theories to Isar ones, while keeping ML proof
  4876 scripts for the time being.
  4877 
  4878 * ML operator HTML.with_charset specifies the charset begin used for
  4879 generated HTML files.  For example:
  4880 
  4881   HTML.with_charset "utf-8" use_thy "Hebrew";
  4882   HTML.with_charset "utf-8" use_thy "Chinese";
  4883 
  4884 
  4885 *** System ***
  4886 
  4887 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4888 isabelle, isatool etc.).
  4889 
  4890 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4891 isatool doc, isatool mkdir, display_drafts etc.).
  4892 
  4893 * isatool usedir: option -f allows specification of the ML file to be
  4894 used by Isabelle; default is ROOT.ML.
  4895 
  4896 * New isatool version outputs the version identifier of the Isabelle
  4897 distribution being used.
  4898 
  4899 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4900 (containing Boolean satisfiability problems) into Isabelle/HOL
  4901 theories.
  4902 
  4903 
  4904 
  4905 New in Isabelle2004 (April 2004)
  4906 --------------------------------
  4907 
  4908 *** General ***
  4909 
  4910 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4911   Replaces linorder.ML.
  4912 
  4913 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4914   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4915   (\<a>...\<z>), are now considered normal letters, and can therefore
  4916   be used anywhere where an ASCII letter (a...zA...Z) has until
  4917   now. COMPATIBILITY: This obviously changes the parsing of some
  4918   terms, especially where a symbol has been used as a binder, say
  4919   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4920   as an identifier.  Fix it by inserting a space around former
  4921   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4922   existing theory and ML files.
  4923 
  4924 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4925 
  4926 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4927   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4928   a normal (but invisible) letter. For multiple letter subscripts repeat
  4929   \<^isub> like this: x\<^isub>1\<^isub>2.
  4930 
  4931 * Pure: There are now sub-/superscripts that can span more than one
  4932   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4933   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4934   superscript. The new control characters are not identifier parts.
  4935 
  4936 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4937   content of "..." to the latex file instead of \isacntrl... . The "..."
  4938   may consist of any printable characters excluding the end bracket >.
  4939 
  4940 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4941   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4942   declare constants "final", which prevents their being given a definition
  4943   later.  It is useful for constants whose behaviour is fixed axiomatically
  4944   rather than definitionally, such as the meta-logic connectives.
  4945 
  4946 * Pure: 'instance' now handles general arities with general sorts
  4947   (i.e. intersections of classes),
  4948 
  4949 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4950   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4951   It can be changed to alter the colors/layout of generated pages.
  4952 
  4953 
  4954 *** Isar ***
  4955 
  4956 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4957   cut_tac, subgoal_tac and thin_tac:
  4958   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4959     locales are no longer forced to write Isar proof scripts.
  4960     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4961     emulations.
  4962   - INCOMPATIBILITY: names of variables to be instantiated may no
  4963     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4964     This is consistent with the instantiation attribute "where".
  4965 
  4966 * Attributes "where" and "of":
  4967   - Now take type variables of instantiated theorem into account when reading
  4968     the instantiation string.  This fixes a bug that caused instantiated
  4969     theorems to have too special types in some circumstances.
  4970   - "where" permits explicit instantiations of type variables.
  4971 
  4972 * Calculation commands "moreover" and "also" no longer interfere with
  4973   current facts ("this"), admitting arbitrary combinations with "then"
  4974   and derived forms.
  4975 
  4976 * Locales:
  4977   - Goal statements involving the context element "includes" no longer
  4978     generate theorems with internal delta predicates (those ending on
  4979     "_axioms") in the premise.
  4980     Resolve particular premise with <locale>.intro to obtain old form.
  4981   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4982     specification and "includes" elements in goal statement.
  4983   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4984     [intro?] and [elim?] (respectively) by default.
  4985   - Experimental command for instantiation of locales in proof contexts:
  4986         instantiate <label>[<attrs>]: <loc>
  4987     Instantiates locale <loc> and adds all its theorems to the current context
  4988     taking into account their attributes.  Label and attrs are optional
  4989     modifiers, like in theorem declarations.  If present, names of
  4990     instantiated theorems are qualified with <label>, and the attributes
  4991     <attrs> are applied after any attributes these theorems might have already.
  4992       If the locale has assumptions, a chained fact of the form
  4993     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4994     are derived.  The command does not support old-style locales declared
  4995     with "locale (open)".
  4996       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4997 
  4998 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4999   (Isar) contexts.
  5000 
  5001 
  5002 *** HOL ***
  5003 
  5004 * Proof import: new image HOL4 contains the imported library from
  5005   the HOL4 system with about 2500 theorems. It is imported by
  5006   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5007   can be used like any other Isabelle image.  See
  5008   HOL/Import/HOL/README for more information.
  5009 
  5010 * Simplifier:
  5011   - Much improved handling of linear and partial orders.
  5012     Reasoners for linear and partial orders are set up for type classes
  5013     "linorder" and "order" respectively, and are added to the default simpset
  5014     as solvers.  This means that the simplifier can build transitivity chains
  5015     to solve goals from the assumptions.
  5016   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5017     of blast or auto after simplification become unnecessary because the goal
  5018     is solved by simplification already.
  5019 
  5020 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5021     all proved in axiomatic type classes for semirings, rings and fields.
  5022 
  5023 * Numerics:
  5024   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5025     now formalized using the Ring_and_Field theory mentioned above.
  5026   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5027     than before, because now they are set up once in a generic manner.
  5028   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5029     Look for the general versions in Ring_and_Field (and Power if they concern
  5030     exponentiation).
  5031 
  5032 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5033 
  5034 * Records:
  5035   - Record types are now by default printed with their type abbreviation
  5036     instead of the list of all field types. This can be configured via
  5037     the reference "print_record_type_abbr".
  5038   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5039     (not enabled by default).
  5040   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5041     EX x. x = sel r to True (not enabled by default).
  5042   - Tactic "record_split_simp_tac" to split and simplify records added.
  5043 
  5044 * 'specification' command added, allowing for definition by
  5045   specification.  There is also an 'ax_specification' command that
  5046   introduces the new constants axiomatically.
  5047 
  5048 * arith(_tac) is now able to generate counterexamples for reals as well.
  5049 
  5050 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5051 
  5052 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5053   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5054 
  5055 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5056   matrix theory to linear programming.
  5057 
  5058 * Unions and Intersections:
  5059   The latex output syntax of UN and INT has been changed
  5060   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5061   i.e. the index formulae has become a subscript.
  5062   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5063 
  5064 * Unions and Intersections over Intervals:
  5065   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5066   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5067   like in normal math, and corresponding versions for < and for intersection.
  5068 
  5069 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5070   lexicographic dictonary ordering has been added as "lexord".
  5071 
  5072 * ML: the legacy theory structures Int and List have been removed. They had
  5073   conflicted with ML Basis Library structures having the same names.
  5074 
  5075 * 'refute' command added to search for (finite) countermodels.  Only works
  5076   for a fragment of HOL.  The installation of an external SAT solver is
  5077   highly recommended.  See "HOL/Refute.thy" for details.
  5078 
  5079 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5080   formulae under an assignment of free variables to random values.
  5081   In contrast to 'refute', it can deal with inductive datatypes,
  5082   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5083   for examples.
  5084 
  5085 
  5086 *** HOLCF ***
  5087 
  5088 * Streams now come with concatenation and are part of the HOLCF image
  5089 
  5090 
  5091 
  5092 New in Isabelle2003 (May 2003)
  5093 ------------------------------
  5094 
  5095 *** General ***
  5096 
  5097 * Provers/simplifier:
  5098 
  5099   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5100     Assumptions are now subject to complete mutual simplification,
  5101     not just from left to right. The simplifier now preserves
  5102     the order of assumptions.
  5103 
  5104     Potential INCOMPATIBILITY:
  5105 
  5106     -- simp sometimes diverges where the old version did
  5107        not, e.g. invoking simp on the goal
  5108 
  5109         [| P (f x); y = x; f x = f y |] ==> Q
  5110 
  5111        now gives rise to the infinite reduction sequence
  5112 
  5113         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5114 
  5115        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5116        kind of problem.
  5117 
  5118     -- Tactics combining classical reasoner and simplification (such as auto)
  5119        are also affected by this change, because many of them rely on
  5120        simp. They may sometimes diverge as well or yield a different numbers
  5121        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5122        in case of problems. Sometimes subsequent calls to the classical
  5123        reasoner will fail because a preceeding call to the simplifier too
  5124        eagerly simplified the goal, e.g. deleted redundant premises.
  5125 
  5126   - The simplifier trace now shows the names of the applied rewrite rules
  5127 
  5128   - You can limit the number of recursive invocations of the simplifier
  5129     during conditional rewriting (where the simplifie tries to solve the
  5130     conditions before applying the rewrite rule):
  5131     ML "simp_depth_limit := n"
  5132     where n is an integer. Thus you can force termination where previously
  5133     the simplifier would diverge.
  5134 
  5135   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5136 
  5137   - No longer aborts on failed congruence proof.  Instead, the
  5138     congruence is ignored.
  5139 
  5140 * Pure: New generic framework for extracting programs from constructive
  5141   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5142   as HOL/Extraction for some case studies.
  5143 
  5144 * Pure: The main goal of the proof state is no longer shown by default, only
  5145 the subgoals. This behaviour is controlled by a new flag.
  5146    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5147 (ML: Proof.show_main_goal).
  5148 
  5149 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5150 rules whose conclusion matches subgoal 1:
  5151       PG menu: Isabelle/Isar -> Show me -> matching rules
  5152 The rules are ordered by how closely they match the subgoal.
  5153 In particular, rules that solve a subgoal outright are displayed first
  5154 (or rather last, the way they are printed).
  5155 (ML: ProofGeneral.print_intros())
  5156 
  5157 * Pure: New flag trace_unify_fail causes unification to print
  5158 diagnostic information (PG: in trace buffer) when it fails. This is
  5159 useful for figuring out why single step proofs like rule, erule or
  5160 assumption failed.
  5161 
  5162 * Pure: Locale specifications now produce predicate definitions
  5163 according to the body of text (covering assumptions modulo local
  5164 definitions); predicate "loc_axioms" covers newly introduced text,
  5165 while "loc" is cumulative wrt. all included locale expressions; the
  5166 latter view is presented only on export into the global theory
  5167 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5168 on the old view without predicates;
  5169 
  5170 * Pure: predefined locales "var" and "struct" are useful for sharing
  5171 parameters (as in CASL, for example); just specify something like
  5172 ``var x + var y + struct M'' as import;
  5173 
  5174 * Pure: improved thms_containing: proper indexing of facts instead of
  5175 raw theorems; check validity of results wrt. current name space;
  5176 include local facts of proof configuration (also covers active
  5177 locales), cover fixed variables in index; may use "_" in term
  5178 specification; an optional limit for the number of printed facts may
  5179 be given (the default is 40);
  5180 
  5181 * Pure: disallow duplicate fact bindings within new-style theory files
  5182 (batch-mode only);
  5183 
  5184 * Provers: improved induct method: assumptions introduced by case
  5185 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5186 the goal statement); "foo" still refers to all facts collectively;
  5187 
  5188 * Provers: the function blast.overloaded has been removed: all constants
  5189 are regarded as potentially overloaded, which improves robustness in exchange
  5190 for slight decrease in efficiency;
  5191 
  5192 * Provers/linorder: New generic prover for transitivity reasoning over
  5193 linear orders.  Note: this prover is not efficient!
  5194 
  5195 * Isar: preview of problems to finish 'show' now produce an error
  5196 rather than just a warning (in interactive mode);
  5197 
  5198 
  5199 *** HOL ***
  5200 
  5201 * arith(_tac)
  5202 
  5203  - Produces a counter example if it cannot prove a goal.
  5204    Note that the counter example may be spurious if the goal is not a formula
  5205    of quantifier-free linear arithmetic.
  5206    In ProofGeneral the counter example appears in the trace buffer.
  5207 
  5208  - Knows about div k and mod k where k is a numeral of type nat or int.
  5209 
  5210  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5211    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5212    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5213 
  5214 * simp's arithmetic capabilities have been enhanced a bit: it now
  5215 takes ~= in premises into account (by performing a case split);
  5216 
  5217 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5218 are distributed over a sum of terms;
  5219 
  5220 * New tactic "trans_tac" and method "trans" instantiate
  5221 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5222 "<=", "<" and "=").
  5223 
  5224 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5225 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5226 
  5227 * 'typedef' command has new option "open" to suppress the set
  5228 definition;
  5229 
  5230 * functions Min and Max on finite sets have been introduced (theory
  5231 Finite_Set);
  5232 
  5233 * attribute [symmetric] now works for relations as well; it turns
  5234 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5235 
  5236 * induct over a !!-quantified statement (say !!x1..xn):
  5237   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5238 
  5239 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5240 %x. None. Warning: empty_def now refers to the previously hidden definition
  5241 of the empty set.
  5242 
  5243 * Algebra: formalization of classical algebra.  Intended as base for
  5244 any algebraic development in Isabelle.  Currently covers group theory
  5245 (up to Sylow's theorem) and ring theory (Universal Property of
  5246 Univariate Polynomials).  Contributions welcome;
  5247 
  5248 * GroupTheory: deleted, since its material has been moved to Algebra;
  5249 
  5250 * Complex: new directory of the complex numbers with numeric constants,
  5251 nonstandard complex numbers, and some complex analysis, standard and
  5252 nonstandard (Jacques Fleuriot);
  5253 
  5254 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5255 
  5256 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5257 Fleuriot);
  5258 
  5259 * Real/HahnBanach: updated and adapted to locales;
  5260 
  5261 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5262 Gray and Kramer);
  5263 
  5264 * UNITY: added the Meier-Sanders theory of progress sets;
  5265 
  5266 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5267 as abstract algorithms, instantiated to the JVM;
  5268 
  5269 * Bali: Java source language formalization. Type system, operational
  5270 semantics, axiomatic semantics. Supported language features:
  5271 classes, interfaces, objects,virtual methods, static methods,
  5272 static/instance fields, arrays, access modifiers, definite
  5273 assignment, exceptions.
  5274 
  5275 
  5276 *** ZF ***
  5277 
  5278 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5279 universe, etc.);
  5280 
  5281 * Main ZF: virtually all theories converted to new-style format;
  5282 
  5283 
  5284 *** ML ***
  5285 
  5286 * Pure: Tactic.prove provides sane interface for internal proofs;
  5287 omits the infamous "standard" operation, so this is more appropriate
  5288 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5289 
  5290 * Pure: improved error reporting of simprocs;
  5291 
  5292 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5293 up simprocs;
  5294 
  5295 
  5296 *** Document preparation ***
  5297 
  5298 * uses \par instead of \\ for line breaks in theory text. This may
  5299 shift some page breaks in large documents. To get the old behaviour
  5300 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5301 
  5302 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5303 other packages
  5304 
  5305 * \<euro> now needs package babel/greek instead of marvosym (which
  5306 broke \Rightarrow)
  5307 
  5308 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5309 textcomp package)
  5310 
  5311 
  5312 
  5313 New in Isabelle2002 (March 2002)
  5314 --------------------------------
  5315 
  5316 *** Document preparation ***
  5317 
  5318 * greatly simplified document preparation setup, including more
  5319 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5320 instructive isatool mkdir; users should basically be able to get
  5321 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5322 users may run a separate document processing stage manually like this:
  5323 "isatool usedir -D output HOL Test && isatool document Test/output";
  5324 
  5325 * theory dependency graph may now be incorporated into documents;
  5326 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5327 with \includegraphics of LaTeX;
  5328 
  5329 * proper spacing of consecutive markup elements, especially text
  5330 blocks after section headings;
  5331 
  5332 * support bold style (for single symbols only), input syntax is like
  5333 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5334 
  5335 * \<bullet> is now output as bold \cdot by default, which looks much
  5336 better in printed text;
  5337 
  5338 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5339 note that these symbols are currently unavailable in Proof General /
  5340 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5341 
  5342 * isatool latex no longer depends on changed TEXINPUTS, instead
  5343 isatool document copies the Isabelle style files to the target
  5344 location;
  5345 
  5346 
  5347 *** Isar ***
  5348 
  5349 * Pure/Provers: improved proof by cases and induction;
  5350   - 'case' command admits impromptu naming of parameters (such as
  5351     "case (Suc n)");
  5352   - 'induct' method divinates rule instantiation from the inductive
  5353     claim; no longer requires excessive ?P bindings for proper
  5354     instantiation of cases;
  5355   - 'induct' method properly enumerates all possibilities of set/type
  5356     rules; as a consequence facts may be also passed through *type*
  5357     rules without further ado;
  5358   - 'induct' method now derives symbolic cases from the *rulified*
  5359     rule (before it used to rulify cases stemming from the internal
  5360     atomized version); this means that the context of a non-atomic
  5361     statement becomes is included in the hypothesis, avoiding the
  5362     slightly cumbersome show "PROP ?case" form;
  5363   - 'induct' may now use elim-style induction rules without chaining
  5364     facts, using ``missing'' premises from the goal state; this allows
  5365     rules stemming from inductive sets to be applied in unstructured
  5366     scripts, while still benefitting from proper handling of non-atomic
  5367     statements; NB: major inductive premises need to be put first, all
  5368     the rest of the goal is passed through the induction;
  5369   - 'induct' proper support for mutual induction involving non-atomic
  5370     rule statements (uses the new concept of simultaneous goals, see
  5371     below);
  5372   - append all possible rule selections, but only use the first
  5373     success (no backtracking);
  5374   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5375   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5376   - added 'print_induct_rules' (covered by help item in recent Proof
  5377     General versions);
  5378   - moved induct/cases attributes to Pure, methods to Provers;
  5379   - generic method setup instantiated for FOL and HOL;
  5380 
  5381 * Pure: support multiple simultaneous goal statements, for example
  5382 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5383 meta-level mechanism, this acts as if several individual goals had
  5384 been stated separately; in particular common proof methods need to be
  5385 repeated in order to cover all claims; note that a single elimination
  5386 step is *not* sufficient to establish the two conjunctions, so this
  5387 fails:
  5388 
  5389   assume "A & B" then have A and B ..   (*".." fails*)
  5390 
  5391 better use "obtain" in situations as above; alternative refer to
  5392 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5393 
  5394 * Pure: proper integration with ``locales''; unlike the original
  5395 version by Florian Kammller, Isar locales package high-level proof
  5396 contexts rather than raw logical ones (e.g. we admit to include
  5397 attributes everywhere); operations on locales include merge and
  5398 rename; support for implicit arguments (``structures''); simultaneous
  5399 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5400 some examples;
  5401 
  5402 * Pure: the following commands have been ``localized'', supporting a
  5403 target locale specification "(in name)": 'lemma', 'theorem',
  5404 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5405 stored both within the locale and at the theory level (exported and
  5406 qualified by the locale name);
  5407 
  5408 * Pure: theory goals may now be specified in ``long'' form, with
  5409 ad-hoc contexts consisting of arbitrary locale elements. for example
  5410 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5411 definitions may be given, too); the result is a meta-level rule with
  5412 the context elements being discharged in the obvious way;
  5413 
  5414 * Pure: new proof command 'using' allows to augment currently used
  5415 facts after a goal statement ('using' is syntactically analogous to
  5416 'apply', but acts on the goal's facts only); this allows chained facts
  5417 to be separated into parts given before and after a claim, as in
  5418 ``from a and b have C using d and e <proof>'';
  5419 
  5420 * Pure: renamed "antecedent" case to "rule_context";
  5421 
  5422 * Pure: new 'judgment' command records explicit information about the
  5423 object-logic embedding (used by several tools internally); no longer
  5424 use hard-wired "Trueprop";
  5425 
  5426 * Pure: added 'corollary' command;
  5427 
  5428 * Pure: fixed 'token_translation' command;
  5429 
  5430 * Pure: removed obsolete 'exported' attribute;
  5431 
  5432 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5433 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5434 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5435 
  5436 * Pure: method 'atomize' presents local goal premises as object-level
  5437 statements (atomic meta-level propositions); setup controlled via
  5438 rewrite rules declarations of 'atomize' attribute; example
  5439 application: 'induct' method with proper rule statements in improper
  5440 proof *scripts*;
  5441 
  5442 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5443 now consider the syntactic context of assumptions, giving a better
  5444 chance to get type-inference of the arguments right (this is
  5445 especially important for locales);
  5446 
  5447 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5448 mode;
  5449 
  5450 * Pure/obtain: the formal conclusion "thesis", being marked as
  5451 ``internal'', may no longer be reference directly in the text;
  5452 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5453 situations;
  5454 
  5455 * Pure: generic 'sym' attribute which declares a rule both as pure
  5456 'elim?' and for the 'symmetric' operation;
  5457 
  5458 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5459 text; the fixed correlation with particular command syntax has been
  5460 discontinued;
  5461 
  5462 * Pure: new method 'rules' is particularly well-suited for proof
  5463 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5464 but often produces more compact proof terms with less detours;
  5465 
  5466 * Pure/Provers/classical: simplified integration with pure rule
  5467 attributes and methods; the classical "intro?/elim?/dest?"
  5468 declarations coincide with the pure ones; the "rule" method no longer
  5469 includes classically swapped intros; "intro" and "elim" methods no
  5470 longer pick rules from the context; also got rid of ML declarations
  5471 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5472 INCOMPATIBILITY;
  5473 
  5474 * Provers/classical: attribute 'swapped' produces classical inversions
  5475 of introduction rules;
  5476 
  5477 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5478 rules instead of full simplifier context; 'iff' attribute handles
  5479 conditional rules;
  5480 
  5481 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5482 
  5483 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5484 "(permissive)" option to recover old behavior;
  5485 
  5486 * HOL: 'inductive' no longer features separate (collective) attributes
  5487 for 'intros' (was found too confusing);
  5488 
  5489 * HOL: properly declared induction rules less_induct and
  5490 wf_induct_rule;
  5491 
  5492 
  5493 *** HOL ***
  5494 
  5495 * HOL: moved over to sane numeral syntax; the new policy is as
  5496 follows:
  5497 
  5498   - 0 and 1 are polymorphic constants, which are defined on any
  5499   numeric type (nat, int, real etc.);
  5500 
  5501   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5502   binary representation internally;
  5503 
  5504   - type nat has special constructor Suc, and generally prefers Suc 0
  5505   over 1::nat and Suc (Suc 0) over 2::nat;
  5506 
  5507 This change may cause significant problems of INCOMPATIBILITY; here
  5508 are some hints on converting existing sources:
  5509 
  5510   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5511   entities, so expressions involving "-" (unary or binary minus) need
  5512   to be spaced properly;
  5513 
  5514   - existing occurrences of "1" may need to be constraint "1::nat" or
  5515   even replaced by Suc 0; similar for old "2";
  5516 
  5517   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5518 
  5519   - remove all special provisions on numerals in proofs;
  5520 
  5521 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5522 representation (depends on bin_arith_simps in the default context);
  5523 
  5524 * HOL: symbolic syntax for x^2 (numeral 2);
  5525 
  5526 * HOL: the class of all HOL types is now called "type" rather than
  5527 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5528 in axclass/classes, instance/arities, and (usually rare) occurrences
  5529 in typings (of consts etc.); internally the class is called
  5530 "HOL.type", ML programs should refer to HOLogic.typeS;
  5531 
  5532 * HOL/record package improvements:
  5533   - new derived operations "fields" to build a partial record section,
  5534     "extend" to promote a fixed record to a record scheme, and
  5535     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5536     declared as simp by default;
  5537   - shared operations ("more", "fields", etc.) now need to be always
  5538     qualified) --- potential INCOMPATIBILITY;
  5539   - removed "make_scheme" operations (use "make" with "extend") --
  5540     INCOMPATIBILITY;
  5541   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5542   - provides cases/induct rules for use with corresponding Isar
  5543     methods (for concrete records, record schemes, concrete more
  5544     parts, and schematic more parts -- in that order);
  5545   - internal definitions directly based on a light-weight abstract
  5546     theory of product types over typedef rather than datatype;
  5547 
  5548 * HOL: generic code generator for generating executable ML code from
  5549 specifications; specific support for HOL constructs such as inductive
  5550 datatypes and sets, as well as recursive functions; can be invoked
  5551 via 'generate_code' theory section;
  5552 
  5553 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5554 
  5555 * HOL: consolidated and renamed several theories.  In particular:
  5556         Ord.thy has been absorbed into HOL.thy
  5557         String.thy has been absorbed into List.thy
  5558 
  5559 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5560 (beware of argument permutation!);
  5561 
  5562 * HOL: linorder_less_split superseded by linorder_cases;
  5563 
  5564 * HOL/List: "nodups" renamed to "distinct";
  5565 
  5566 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5567 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5568   - Ex_def has changed, now need to use some_eq_ex
  5569 
  5570 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5571 in this (rare) case use:
  5572 
  5573   delSWrapper "split_all_tac"
  5574   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5575 
  5576 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5577 MAY FAIL;
  5578 
  5579 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5580 Isabelle's type classes, ^ on functions and relations has too general
  5581 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5582 necessary to attach explicit type constraints;
  5583 
  5584 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5585 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5586 renamed accordingly (eg "compI" -> "rel_compI").
  5587 
  5588 * HOL: syntax translations now work properly with numerals and records
  5589 expressions;
  5590 
  5591 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5592 of "lam" -- INCOMPATIBILITY;
  5593 
  5594 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5595 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5596 renamed "Product_Type.unit";
  5597 
  5598 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5599 
  5600 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5601 the "cases" method);
  5602 
  5603 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5604 Florian Kammller);
  5605 
  5606 * HOL/IMP: updated and converted to new-style theory format; several
  5607 parts turned into readable document, with proper Isar proof texts and
  5608 some explanations (by Gerwin Klein);
  5609 
  5610 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5611 
  5612 * HOL-Hyperreal is now a logic image;
  5613 
  5614 
  5615 *** HOLCF ***
  5616 
  5617 * Isar: consts/constdefs supports mixfix syntax for continuous
  5618 operations;
  5619 
  5620 * Isar: domain package adapted to new-style theory format, e.g. see
  5621 HOLCF/ex/Dnat.thy;
  5622 
  5623 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5624 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5625 lift.induct_tac, always use UU instead of Undef;
  5626 
  5627 * HOLCF/IMP: updated and converted to new-style theory;
  5628 
  5629 
  5630 *** ZF ***
  5631 
  5632 * Isar: proper integration of logic-specific tools and packages,
  5633 including theory commands '(co)inductive', '(co)datatype',
  5634 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5635 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5636 
  5637 * theory Main no longer includes AC; for the Axiom of Choice, base
  5638 your theory on Main_ZFC;
  5639 
  5640 * the integer library now covers quotients and remainders, with many
  5641 laws relating division to addition, multiplication, etc.;
  5642 
  5643 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5644 typeless version of the formalism;
  5645 
  5646 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5647 format;
  5648 
  5649 * ZF/Induct: new directory for examples of inductive definitions,
  5650 including theory Multiset for multiset orderings; converted to
  5651 new-style theory format;
  5652 
  5653 * ZF: many new theorems about lists, ordinals, etc.;
  5654 
  5655 
  5656 *** General ***
  5657 
  5658 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5659 variable proof controls level of detail: 0 = no proofs (only oracle
  5660 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5661 also ref manual for further ML interfaces;
  5662 
  5663 * Pure/axclass: removed obsolete ML interface
  5664 goal_subclass/goal_arity;
  5665 
  5666 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5667 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5668 separate tokens, so expressions involving minus need to be spaced
  5669 properly;
  5670 
  5671 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5672 rather than "infixl" or "infixr";
  5673 
  5674 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5675 sort constraint specifications in type inference; e.g. "x::_::foo"
  5676 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5677 type variable);
  5678 
  5679 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5680 control output of nested => (types); the default behavior is
  5681 "type_brackets";
  5682 
  5683 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5684 tokens into AST constants;
  5685 
  5686 * Pure/syntax: prefer later declarations of translations and print
  5687 translation functions; potential INCOMPATIBILITY: need to reverse
  5688 multiple declarations for same syntax element constant;
  5689 
  5690 * Pure/show_hyps reset by default (in accordance to existing Isar
  5691 practice);
  5692 
  5693 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5694 addSafter;
  5695 
  5696 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5697 as well;
  5698 
  5699 * system: tested support for MacOS X; should be able to get Isabelle +
  5700 Proof General to work in a plain Terminal after installing Poly/ML
  5701 (e.g. from the Isabelle distribution area) and GNU bash alone
  5702 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5703 support requires further installations, e.g. from
  5704 http://fink.sourceforge.net/);
  5705 
  5706 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5707 
  5708 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5709 of 40 MB), cf. ML_OPTIONS;
  5710 
  5711 * system: Proof General keywords specification is now part of the
  5712 Isabelle distribution (see etc/isar-keywords.el);
  5713 
  5714 * system: support for persistent Proof General sessions (refrain from
  5715 outdating all loaded theories on startup); user may create writable
  5716 logic images like this: ``isabelle -q HOL Test'';
  5717 
  5718 * system: smart selection of Isabelle process versus Isabelle
  5719 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5720 run both "isabelle" and "Isabelle" even if file names are badly
  5721 damaged (executable inspects the case of the first letter of its own
  5722 name); added separate "isabelle-process" and "isabelle-interface";
  5723 
  5724 * system: refrain from any attempt at filtering input streams; no
  5725 longer support ``8bit'' encoding of old isabelle font, instead proper
  5726 iso-latin characters may now be used; the related isatools
  5727 "symbolinput" and "nonascii" have disappeared as well;
  5728 
  5729 * system: removed old "xterm" interface (the print modes "xterm" and
  5730 "xterm_color" are still available for direct use in a suitable
  5731 terminal);
  5732 
  5733 
  5734 
  5735 New in Isabelle99-2 (February 2001)
  5736 -----------------------------------
  5737 
  5738 *** Overview of INCOMPATIBILITIES ***
  5739 
  5740 * HOL: please note that theories in the Library and elsewhere often use the
  5741 new-style (Isar) format; to refer to their theorems in an ML script you must
  5742 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5743 
  5744 * HOL: inductive package no longer splits induction rule aggressively,
  5745 but only as far as specified by the introductions given; the old
  5746 format may be recovered via ML function complete_split_rule or attribute
  5747 'split_rule (complete)';
  5748 
  5749 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5750 gfp_Tarski to gfp_unfold;
  5751 
  5752 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5753 
  5754 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5755 relation); infix "^^" has been renamed "``"; infix "``" has been
  5756 renamed "`"; "univalent" has been renamed "single_valued";
  5757 
  5758 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5759 operation;
  5760 
  5761 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5762 
  5763 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5764 
  5765 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5766 consequence, it is no longer monotonic wrt. the local goal context
  5767 (which is now passed through the inductive cases);
  5768 
  5769 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5770 \<gg> to \<ggreater>;
  5771 
  5772 
  5773 *** Document preparation ***
  5774 
  5775 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5776 available: are "it" for near math-mode best-style output, "sl" for
  5777 slanted text style, and "tt" for plain type-writer; if no
  5778 \isabellestyle command is given, output is according to slanted
  5779 type-writer);
  5780 
  5781 * support sub/super scripts (for single symbols only), input syntax is
  5782 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5783 
  5784 * some more standard symbols; see Appendix A of the system manual for
  5785 the complete list of symbols defined in isabellesym.sty;
  5786 
  5787 * improved isabelle style files; more abstract symbol implementation
  5788 (should now use \isamath{...} and \isatext{...} in custom symbol
  5789 definitions);
  5790 
  5791 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5792 state; Note that presentation of goal states does not conform to
  5793 actual human-readable proof documents.  Please do not include goal
  5794 states into document output unless you really know what you are doing!
  5795 
  5796 * proper indentation of antiquoted output with proportional LaTeX
  5797 fonts;
  5798 
  5799 * no_document ML operator temporarily disables LaTeX document
  5800 generation;
  5801 
  5802 * isatool unsymbolize tunes sources for plain ASCII communication;
  5803 
  5804 
  5805 *** Isar ***
  5806 
  5807 * Pure: Isar now suffers initial goal statements to contain unbound
  5808 schematic variables (this does not conform to actual readable proof
  5809 documents, due to unpredictable outcome and non-compositional proof
  5810 checking); users who know what they are doing may use schematic goals
  5811 for Prolog-style synthesis of proven results;
  5812 
  5813 * Pure: assumption method (an implicit finishing) now handles actual
  5814 rules as well;
  5815 
  5816 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5817 initial goal, declare "that" only as Pure intro (only for single
  5818 steps); the "that" rule assumption may now be involved in implicit
  5819 finishing, thus ".." becomes a feasible for trivial obtains;
  5820 
  5821 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5822 instance proofs may be performed by "..";
  5823 
  5824 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5825 statements as well;
  5826 
  5827 * Pure: more robust selection of calculational rules;
  5828 
  5829 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5830 rule (as well as the assumption rule);
  5831 
  5832 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5833 lemmas, using the graph browser tool;
  5834 
  5835 * Pure: predict failure of "show" in interactive mode;
  5836 
  5837 * Pure: 'thms_containing' now takes actual terms as arguments;
  5838 
  5839 * HOL: improved method 'induct' --- now handles non-atomic goals
  5840 (potential INCOMPATIBILITY); tuned error handling;
  5841 
  5842 * HOL: cases and induct rules now provide explicit hints about the
  5843 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5844 any remaining facts are inserted into the goal verbatim;
  5845 
  5846 * HOL: local contexts (aka cases) may now contain term bindings as
  5847 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5848 the result to be shown in each case;
  5849 
  5850 * HOL: added 'recdef_tc' command;
  5851 
  5852 * isatool convert assists in eliminating legacy ML scripts;
  5853 
  5854 
  5855 *** HOL ***
  5856 
  5857 * HOL/Library: a collection of generic theories to be used together
  5858 with main HOL; the theory loader path already includes this directory
  5859 by default; the following existing theories have been moved here:
  5860 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5861 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5862 
  5863 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5864 modelling and verification task performed in Isabelle/HOL +
  5865 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5866 
  5867 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5868 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5869 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5870 'domain', this makes the theory consistent with mathematical
  5871 literature;
  5872 
  5873 * HOL basics: added overloaded operations "inverse" and "divide"
  5874 (infix "/"), syntax for generic "abs" operation, generic summation
  5875 operator \<Sum>;
  5876 
  5877 * HOL/typedef: simplified package, provide more useful rules (see also
  5878 HOL/subset.thy);
  5879 
  5880 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5881 now expressed as a proper nested rule (old-style tactic scripts may
  5882 require atomize_strip_tac to cope with non-atomic premises);
  5883 
  5884 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5885 to "split_conv" (old name still available for compatibility);
  5886 
  5887 * HOL: improved concrete syntax for strings (e.g. allows translation
  5888 rules with string literals);
  5889 
  5890 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5891  and Fleuriot's mechanization of analysis, including the transcendental
  5892  functions for the reals;
  5893 
  5894 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5895 
  5896 
  5897 *** CTT ***
  5898 
  5899 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5900 "lam" is displayed as TWO lambda-symbols
  5901 
  5902 * CTT: theory Main now available, containing everything (that is, Bool
  5903 and Arith);
  5904 
  5905 
  5906 *** General ***
  5907 
  5908 * Pure: the Simplifier has been implemented properly as a derived rule
  5909 outside of the actual kernel (at last!); the overall performance
  5910 penalty in practical applications is about 50%, while reliability of
  5911 the Isabelle inference kernel has been greatly improved;
  5912 
  5913 * print modes "brackets" and "no_brackets" control output of nested =>
  5914 (types) and ==> (props); the default behaviour is "brackets";
  5915 
  5916 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5917 as assumptions as well;
  5918 
  5919 * system: support Poly/ML 4.0;
  5920 
  5921 * system: isatool install handles KDE version 1 or 2;
  5922 
  5923 
  5924 
  5925 New in Isabelle99-1 (October 2000)
  5926 ----------------------------------
  5927 
  5928 *** Overview of INCOMPATIBILITIES ***
  5929 
  5930 * HOL: simplification of natural numbers is much changed; to partly
  5931 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5932 issue the following ML commands:
  5933 
  5934   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5935   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5936 
  5937 * HOL: simplification no longer dives into case-expressions; this is
  5938 controlled by "t.weak_case_cong" for each datatype t;
  5939 
  5940 * HOL: nat_less_induct renamed to less_induct;
  5941 
  5942 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5943 fixsome to patch .thy and .ML sources automatically;
  5944 
  5945   select_equality  -> some_equality
  5946   select_eq_Ex     -> some_eq_ex
  5947   selectI2EX       -> someI2_ex
  5948   selectI2         -> someI2
  5949   selectI          -> someI
  5950   select1_equality -> some1_equality
  5951   Eps_sym_eq       -> some_sym_eq_trivial
  5952   Eps_eq           -> some_eq_trivial
  5953 
  5954 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5955 
  5956 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5957 instead);
  5958 
  5959 * HOL: the recursion equations generated by 'recdef' are now called
  5960 f.simps instead of f.rules;
  5961 
  5962 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5963 
  5964 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5965 sometimes be needed;
  5966 
  5967 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5968 
  5969 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5970 
  5971 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5972 product is now "<*>" instead of "Times"; the lexicographic product is
  5973 now "<*lex*>" instead of "**";
  5974 
  5975 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5976 of main HOL, but was unused); better use HOL's datatype package;
  5977 
  5978 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5979 the old syntax may be recovered as follows:
  5980 
  5981   syntax (symbols)
  5982     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5983       (infixl "\\<oplus>" 100)
  5984 
  5985 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5986 
  5987 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5988 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5989 internally;
  5990 
  5991 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5992 changed from A/r to A//r;
  5993 
  5994 * ZF: new treatment of arithmetic (nat & int) may break some old
  5995 proofs;
  5996 
  5997 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5998 rulify -> rule_format, elimify -> elim_format, ...);
  5999 
  6000 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6001 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6002 should have to change intro!! to intro? only); replaced "delrule" by
  6003 "rule del";
  6004 
  6005 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6006 
  6007 * Provers: strengthened force_tac by using new first_best_tac;
  6008 
  6009 * LaTeX document preparation: several changes of isabelle.sty (see
  6010 lib/texinputs);
  6011 
  6012 
  6013 *** Document preparation ***
  6014 
  6015 * formal comments (text blocks etc.) in new-style theories may now
  6016 contain antiquotations of thm/prop/term/typ/text to be presented
  6017 according to latex print mode; concrete syntax is like this:
  6018 @{term[show_types] "f(x) = a + x"};
  6019 
  6020 * isatool mkdir provides easy setup of Isabelle session directories,
  6021 including proper document sources;
  6022 
  6023 * generated LaTeX sources are now deleted after successful run
  6024 (isatool document -c); may retain a copy somewhere else via -D option
  6025 of isatool usedir;
  6026 
  6027 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6028 style files, achieving self-contained LaTeX sources and simplifying
  6029 LaTeX debugging;
  6030 
  6031 * old-style theories now produce (crude) LaTeX output as well;
  6032 
  6033 * browser info session directories are now self-contained (may be put
  6034 on WWW server seperately); improved graphs of nested sessions; removed
  6035 graph for 'all sessions';
  6036 
  6037 * several improvements in isabelle style files; \isabellestyle{it}
  6038 produces fake math mode output; \isamarkupheader is now \section by
  6039 default; see lib/texinputs/isabelle.sty etc.;
  6040 
  6041 
  6042 *** Isar ***
  6043 
  6044 * Isar/Pure: local results and corresponding term bindings are now
  6045 subject to Hindley-Milner polymorphism (similar to ML); this
  6046 accommodates incremental type-inference very nicely;
  6047 
  6048 * Isar/Pure: new derived language element 'obtain' supports
  6049 generalized existence reasoning;
  6050 
  6051 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6052 support accumulation of results, without applying any rules yet;
  6053 useful to collect intermediate results without explicit name
  6054 references, and for use with transitivity rules with more than 2
  6055 premises;
  6056 
  6057 * Isar/Pure: scalable support for case-analysis type proofs: new
  6058 'case' language element refers to local contexts symbolically, as
  6059 produced by certain proof methods; internally, case names are attached
  6060 to theorems as "tags";
  6061 
  6062 * Isar/Pure: theory command 'hide' removes declarations from
  6063 class/type/const name spaces;
  6064 
  6065 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6066 indicate potential overloading;
  6067 
  6068 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6069 
  6070 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6071 "{a,b,c}" instead of {a,b,c};
  6072 
  6073 * Isar/Pure now provides its own version of intro/elim/dest
  6074 attributes; useful for building new logics, but beware of confusion
  6075 with the version in Provers/classical;
  6076 
  6077 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6078 case name 'antecedent';
  6079 
  6080 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6081 to the current context is now done automatically);
  6082 
  6083 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6084 for definining proof methods in ML;
  6085 
  6086 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6087 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6088 most cases, one should have to change intro!! to intro? only);
  6089 replaced "delrule" by "rule del";
  6090 
  6091 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6092 'symmetric' attribute (the latter supercedes [RS sym]);
  6093 
  6094 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6095 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6096 well (including splits);
  6097 
  6098 * Isar/Provers: Simplifier and Classical methods now support all kind
  6099 of modifiers used in the past, including 'cong', 'iff', etc.
  6100 
  6101 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6102 of Simplifier and Classical reasoner);
  6103 
  6104 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6105 now support named cases; major packages (inductive, datatype, primrec,
  6106 recdef) support case names and properly name parameters;
  6107 
  6108 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6109 monotonicity conditions are extracted to be proven at end of
  6110 calculations;
  6111 
  6112 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6113 method anyway;
  6114 
  6115 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6116 split_if split_if_asm; datatype package provides theorems foo.splits =
  6117 foo.split foo.split_asm for each datatype;
  6118 
  6119 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6120 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6121 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6122 use "(cases (simplified))" method in proper proof texts);
  6123 
  6124 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6125 
  6126 * Isar: names of theorems etc. may be natural numbers as well;
  6127 
  6128 * Isar: 'pr' command: optional arguments for goals_limit and
  6129 ProofContext.prems_limit; no longer prints theory contexts, but only
  6130 proof states;
  6131 
  6132 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6133 additional print modes to be specified; e.g. "pr(latex)" will print
  6134 proof state according to the Isabelle LaTeX style;
  6135 
  6136 * Isar: improved support for emulating tactic scripts, including proof
  6137 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6138 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6139 (for HOL datatypes);
  6140 
  6141 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6142 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6143 'proof method scripts' have to be in depth-first order;
  6144 
  6145 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6146 
  6147 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6148 should instead use individual commands for printing items
  6149 (print_commands, print_methods etc.);
  6150 
  6151 * Isar: added 'nothing' --- the empty list of theorems;
  6152 
  6153 
  6154 *** HOL ***
  6155 
  6156 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6157 corresponding virtual machine and a specification of its bytecode
  6158 verifier and a lightweight bytecode verifier, including proofs of
  6159 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6160 Cornelia Pusch (see also the homepage of project Bali at
  6161 http://isabelle.in.tum.de/Bali/);
  6162 
  6163 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6164 Clemens Ballarin;
  6165 
  6166 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6167 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6168 Rasmussen;
  6169 
  6170 * HOL/Lattice: fundamental concepts of lattice theory and order
  6171 structures, including duals, properties of bounds versus algebraic
  6172 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6173 Theorem for complete lattices etc.; may also serve as a demonstration
  6174 for abstract algebraic reasoning using axiomatic type classes, and
  6175 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6176 
  6177 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6178 von Oheimb;
  6179 
  6180 * HOL/IMPP: extension of IMP with local variables and mutually
  6181 recursive procedures, by David von Oheimb;
  6182 
  6183 * HOL/Lambda: converted into new-style theory and document;
  6184 
  6185 * HOL/ex/Multiquote: example of multiple nested quotations and
  6186 anti-quotations -- basically a generalized version of de-Bruijn
  6187 representation; very useful in avoiding lifting of operations;
  6188 
  6189 * HOL/record: added general record equality rule to simpset; fixed
  6190 select-update simplification procedure to handle extended records as
  6191 well; admit "r" as field name;
  6192 
  6193 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6194 other numeric types and also as the identity of groups, rings, etc.;
  6195 
  6196 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6197 Types nat and int belong to this axclass;
  6198 
  6199 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6200    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6201    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6202   two terms #m*u and #n*u are replaced by #(m+n)*u
  6203     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6204   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6205     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6206 
  6207 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6208 powerful prover for predicate logic but knows nothing of clasets; see
  6209 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6210 
  6211 * HOL: new version of "case_tac" subsumes both boolean case split and
  6212 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6213 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6214 
  6215 * HOL: simplification no longer dives into case-expressions: only the
  6216 selector expression is simplified, but not the remaining arms; to
  6217 enable full simplification of case-expressions for datatype t, you may
  6218 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6219 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6220 
  6221 * HOL/recdef: the recursion equations generated by 'recdef' for
  6222 function 'f' are now called f.simps instead of f.rules; if all
  6223 termination conditions are proved automatically, these simplification
  6224 rules are added to the simpset, as in primrec; rules may be named
  6225 individually as well, resulting in a separate list of theorems for
  6226 each equation;
  6227 
  6228 * HOL/While is a new theory that provides a while-combinator. It
  6229 permits the definition of tail-recursive functions without the
  6230 provision of a termination measure. The latter is necessary once the
  6231 invariant proof rule for while is applied.
  6232 
  6233 * HOL: new (overloaded) notation for the set of elements below/abov