NEWS
author wenzelm
Thu Sep 02 00:48:07 2010 +0200 (2010-09-02)
changeset 38980 af73cf0dc31f
parent 38864 4abe644fcea5
child 39050 600de0485859
child 39079 bddc3d3f6e53
permissions -rw-r--r--
turned show_question_marks into proper configuration option;
show_question_marks only affects regular type/term pretty printing, not raw Term.string_of_vname;
tuned;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    10 a Unicode character is treated as a single symbol, not a sequence of
    11 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    12 contain symbols without further backslash escapes, Unicode can now be
    13 used here as well.  Recall that Symbol.explode in ML provides a
    14 consistent view on symbols, while raw explode (or String.explode)
    15 merely give a byte-oriented representation.
    16 
    17 * Theory loading: only the master source file is looked-up in the
    18 implicit load path, all other files are addressed relatively to its
    19 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    20 
    21 * Special treatment of ML file names has been discontinued.
    22 Historically, optional extensions .ML or .sml were added on demand --
    23 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    24 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    25 
    26 * Various options that affect pretty printing etc. are now properly
    27 handled within the context via configuration options, instead of
    28 unsynchronized references.  There are both ML Config.T entities and
    29 Isar declaration attributes to access these.
    30 
    31   ML:                       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   show_question_marks       show_question_marks
    40 
    41 Note that the corresponding "..._default" references may be only
    42 changed globally at the ROOT session setup, but *not* within a theory.
    43 
    44 
    45 *** Pure ***
    46 
    47 * Interpretation command 'interpret' accepts a list of equations like
    48 'interpretation' does.
    49 
    50 * Diagnostic command 'print_interps' prints interpretations in proofs
    51 in addition to interpretations in theories.
    52 
    53 * Discontinued obsolete 'global' and 'local' commands to manipulate
    54 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    55 Sign.root_path and Sign.local_path may be applied directly where this
    56 feature is still required for historical reasons.
    57 
    58 
    59 *** HOL ***
    60 
    61 * Renamed class eq and constant eq (for code generation) to class equal
    62 and constant equal, plus renaming of related facts and various tuning.
    63 INCOMPATIBILITY.
    64 
    65 * Scala (2.8 or higher) has been added to the target languages of
    66 the code generator.
    67 
    68 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    69 
    70 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    71 canonical names for instance definitions for functions; various improvements.
    72 INCOMPATIBILITY.
    73 
    74 * Records: logical foundation type for records do not carry a '_type' suffix
    75 any longer.  INCOMPATIBILITY.
    76 
    77 * Code generation for records: more idiomatic representation of record types.
    78 Warning: records are not covered by ancient SML code generation any longer.
    79 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    80 helps to succeed then:
    81 
    82   record 'a foo = ...
    83   ...
    84   rep_datatype foo_ext ...
    85 
    86 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    87 INCOMPATIBILITY.
    88 
    89 * Quickcheck in locales considers interpretations of that locale for
    90 counter example search.
    91 
    92 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    93 in Library/State_Monad has been changed to avoid ambiguities.
    94 INCOMPATIBILITY.
    95 
    96 * Code generator: export_code without explicit file declaration prints
    97 to standard output.  INCOMPATIBILITY.
    98 
    99 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   100 respectively.  INCOMPATIBILITY.
   101 
   102 * Constant "split" has been merged with constant "prod_case";  names
   103 of ML functions, facts etc. involving split have been retained so far,
   104 though.  INCOMPATIBILITY.
   105 
   106 * Dropped old infix syntax "mem" for List.member;  use "in set"
   107 instead.  INCOMPATIBILITY.
   108 
   109 * Refactoring of code-generation specific operations in List.thy
   110 
   111   constants
   112     null ~> List.null
   113 
   114   facts
   115     mem_iff ~> member_def
   116     null_empty ~> null_def
   117 
   118 INCOMPATIBILITY.  Note that these were not suppossed to be used
   119 regularly unless for striking reasons;  their main purpose was code
   120 generation.
   121 
   122 * Some previously unqualified names have been qualified:
   123 
   124   types
   125     bool ~> HOL.bool
   126     nat ~> Nat.nat
   127 
   128   constants
   129     Trueprop ~> HOL.Trueprop
   130     True ~> HOL.True
   131     False ~> HOL.False
   132     op & ~> HOL.conj
   133     op | ~> HOL.disj
   134     op --> ~> HOL.implies
   135     op = ~> HOL.eq
   136     Not ~> HOL.Not
   137     The ~> HOL.The
   138     All ~> HOL.All
   139     Ex ~> HOL.Ex
   140     Ex1 ~> HOL.Ex1
   141     Let ~> HOL.Let
   142     If ~> HOL.If
   143     Ball ~> Set.Ball
   144     Bex ~> Set.Bex
   145     Suc ~> Nat.Suc
   146     Pair ~> Product_Type.Pair
   147     fst ~> Product_Type.fst
   148     snd ~> Product_Type.snd
   149     curry ~> Product_Type.curry
   150     op : ~> Set.member
   151     Collect ~> Set.Collect
   152 
   153 INCOMPATIBILITY.
   154 
   155 * Removed simplifier congruence rule of "prod_case", as has for long
   156 been the case with "split".  INCOMPATIBILITY.
   157 
   158 * Datatype package: theorems generated for executable equality
   159 (class eq) carry proper names and are treated as default code
   160 equations.
   161 
   162 * List.thy: use various operations from the Haskell prelude when
   163 generating Haskell code.
   164 
   165 * code_simp.ML and method code_simp: simplification with rules determined
   166 by code generator.
   167 
   168 * code generator: do not print function definitions for case
   169 combinators any longer.
   170 
   171 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   172 theorems are now stated in terms of euclidean spaces instead of finite
   173 cartesian products.
   174 
   175   types
   176     real ^ 'n ~>  'a::real_vector
   177               ~>  'a::euclidean_space
   178               ~>  'a::ordered_euclidean_space
   179         (depends on your needs)
   180 
   181   constants
   182      _ $ _        ~> _ $$ _
   183      \<chi> x. _  ~> \<chi>\<chi> x. _
   184      CARD('n)     ~> DIM('a)
   185 
   186 Also note that the indices are now natural numbers and not from some finite
   187 type. Finite cartesian products of euclidean spaces, products of euclidean
   188 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   189 
   190 INCOMPATIBILITY.
   191 
   192 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   193 as value for measures. Introduces Lebesgue Measure based on the integral in
   194 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   195 spaces.
   196 
   197  INCOMPATIBILITY.
   198 
   199 * Inductive package: offers new command "inductive_simps" to automatically
   200 derive instantiated and simplified equations for inductive predicates,
   201 similar to inductive_cases.
   202 
   203 
   204 *** FOL ***
   205 
   206 * All constant names are now qualified.  INCOMPATIBILITY.
   207 
   208 
   209 *** ZF ***
   210 
   211 * All constant names are now qualified.  INCOMPATIBILITY.
   212 
   213 
   214 *** ML ***
   215 
   216 * Configuration option show_question_marks only affects regular pretty
   217 printing of types and terms, not raw Term.string_of_vname.
   218 
   219 * ML structure Unsynchronized never opened, not even in Isar
   220 interaction mode as before.  Old Unsynchronized.set etc. have been
   221 discontinued -- use plain := instead.  This should be *rare* anyway,
   222 since modern tools always work via official context data, notably
   223 configuration options.
   224 
   225 * ML antiquotations @{theory} and @{theory_ref} refer to named
   226 theories from the ancestry of the current context, not any accidental
   227 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   228 change in semantics.
   229 
   230 
   231 *** System ***
   232 
   233 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   234 
   235 
   236 
   237 New in Isabelle2009-2 (June 2010)
   238 ---------------------------------
   239 
   240 *** General ***
   241 
   242 * Authentic syntax for *all* logical entities (type classes, type
   243 constructors, term constants): provides simple and robust
   244 correspondence between formal entities and concrete syntax.  Within
   245 the parse tree / AST representations, "constants" are decorated by
   246 their category (class, type, const) and spelled out explicitly with
   247 their full internal name.
   248 
   249 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   250 and translations (translation rules and translation functions in ML).
   251 Some hints on upgrading:
   252 
   253   - Many existing uses of 'syntax' and 'translations' can be replaced
   254     by more modern 'type_notation', 'notation' and 'abbreviation',
   255     which are independent of this issue.
   256 
   257   - 'translations' require markup within the AST; the term syntax
   258     provides the following special forms:
   259 
   260       CONST c   -- produces syntax version of constant c from context
   261       XCONST c  -- literally c, checked as constant from context
   262       c         -- literally c, if declared by 'syntax'
   263 
   264     Plain identifiers are treated as AST variables -- occasionally the
   265     system indicates accidental variables via the error "rhs contains
   266     extra variables".
   267 
   268     Type classes and type constructors are marked according to their
   269     concrete syntax.  Some old translations rules need to be written
   270     for the "type" category, using type constructor application
   271     instead of pseudo-term application of the default category
   272     "logic".
   273 
   274   - 'parse_translation' etc. in ML may use the following
   275     antiquotations:
   276 
   277       @{class_syntax c}   -- type class c within parse tree / AST
   278       @{term_syntax c}    -- type constructor c within parse tree / AST
   279       @{const_syntax c}   -- ML version of "CONST c" above
   280       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   281 
   282   - Literal types within 'typed_print_translations', i.e. those *not*
   283     represented as pseudo-terms are represented verbatim.  Use @{class
   284     c} or @{type_name c} here instead of the above syntax
   285     antiquotations.
   286 
   287 Note that old non-authentic syntax was based on unqualified base
   288 names, so all of the above "constant" names would coincide.  Recall
   289 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   290 diagnose syntax problems.
   291 
   292 * Type constructors admit general mixfix syntax, not just infix.
   293 
   294 * Concrete syntax may be attached to local entities without a proof
   295 body, too.  This works via regular mixfix annotations for 'fix',
   296 'def', 'obtain' etc. or via the explicit 'write' command, which is
   297 similar to the 'notation' command in theory specifications.
   298 
   299 * Discontinued unnamed infix syntax (legacy feature for many years) --
   300 need to specify constant name and syntax separately.  Internal ML
   301 datatype constructors have been renamed from InfixName to Infix etc.
   302 Minor INCOMPATIBILITY.
   303 
   304 * Schematic theorem statements need to be explicitly markup as such,
   305 via commands 'schematic_lemma', 'schematic_theorem',
   306 'schematic_corollary'.  Thus the relevance of the proof is made
   307 syntactically clear, which impacts performance in a parallel or
   308 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   309 
   310 * Use of cumulative prems via "!" in some proof methods has been
   311 discontinued (old legacy feature).
   312 
   313 * References 'trace_simp' and 'debug_simp' have been replaced by
   314 configuration options stored in the context. Enabling tracing (the
   315 case of debugging is similar) in proofs works via
   316 
   317   using [[trace_simp = true]]
   318 
   319 Tracing is then active for all invocations of the simplifier in
   320 subsequent goal refinement steps. Tracing may also still be enabled or
   321 disabled via the ProofGeneral settings menu.
   322 
   323 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   324 'hide_fact' replace the former 'hide' KIND command.  Minor
   325 INCOMPATIBILITY.
   326 
   327 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   328 more efficient than combinations with -q1 or -q2.
   329 
   330 
   331 *** Pure ***
   332 
   333 * Proofterms record type-class reasoning explicitly, using the
   334 "unconstrain" operation internally.  This eliminates all sort
   335 constraints from a theorem and proof, introducing explicit
   336 OFCLASS-premises.  On the proof term level, this operation is
   337 automatically applied at theorem boundaries, such that closed proofs
   338 are always free of sort constraints.  INCOMPATIBILITY for tools that
   339 inspect proof terms.
   340 
   341 * Local theory specifications may depend on extra type variables that
   342 are not present in the result type -- arguments TYPE('a) :: 'a itself
   343 are added internally.  For example:
   344 
   345   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   346 
   347 * Predicates of locales introduced by classes carry a mandatory
   348 "class" prefix.  INCOMPATIBILITY.
   349 
   350 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   351 
   352 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   353 'class' instead.
   354 
   355 * Command 'code_reflect' allows to incorporate generated ML code into
   356 runtime environment; replaces immature code_datatype antiquotation.
   357 INCOMPATIBILITY.
   358 
   359 * Code generator: simple concept for abstract datatypes obeying
   360 invariants.
   361 
   362 * Code generator: details of internal data cache have no impact on the
   363 user space functionality any longer.
   364 
   365 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   366 subgoals.  This is more appropriate for interpretations with 'where'.
   367 INCOMPATIBILITY.
   368 
   369 * Command 'example_proof' opens an empty proof body.  This allows to
   370 experiment with Isar, without producing any persistent result.
   371 
   372 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   373 within a local theory context, with explicit checking of the
   374 constructors involved (in contrast to the raw 'syntax' versions).
   375 
   376 * Commands 'types' and 'typedecl' now work within a local theory
   377 context -- without introducing dependencies on parameters or
   378 assumptions, which is not possible in Isabelle/Pure.
   379 
   380 * Command 'defaultsort' has been renamed to 'default_sort', it works
   381 within a local theory context.  Minor INCOMPATIBILITY.
   382 
   383 
   384 *** HOL ***
   385 
   386 * Command 'typedef' now works within a local theory context -- without
   387 introducing dependencies on parameters or assumptions, which is not
   388 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   389 contain multiple interpretations of local typedefs (with different
   390 non-emptiness proofs), even in a global theory context.
   391 
   392 * New package for quotient types.  Commands 'quotient_type' and
   393 'quotient_definition' may be used for defining types and constants by
   394 quotient constructions.  An example is the type of integers created by
   395 quotienting pairs of natural numbers:
   396 
   397   fun
   398     intrel :: "(nat * nat) => (nat * nat) => bool"
   399   where
   400     "intrel (x, y) (u, v) = (x + v = u + y)"
   401 
   402   quotient_type int = "nat * nat" / intrel
   403     by (auto simp add: equivp_def expand_fun_eq)
   404 
   405   quotient_definition
   406     "0::int" is "(0::nat, 0::nat)"
   407 
   408 The method "lifting" can be used to lift of theorems from the
   409 underlying "raw" type to the quotient type.  The example
   410 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   411 construction and provides a reasoning infrastructure for finite sets.
   412 
   413 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   414 clash with new theory Quotient in Main HOL.
   415 
   416 * Moved the SMT binding into the main HOL session, eliminating
   417 separate HOL-SMT session.
   418 
   419 * List membership infix mem operation is only an input abbreviation.
   420 INCOMPATIBILITY.
   421 
   422 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   423 for future developements; former Library/Word.thy is still present in
   424 the AFP entry RSAPPS.
   425 
   426 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   427 longer shadowed.  INCOMPATIBILITY.
   428 
   429 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   430 INCOMPATIBILITY.
   431 
   432 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   433 INCOMPATIBILITY.
   434 
   435 * Dropped normalizing_semiring etc; use the facts in semiring classes
   436 instead.  INCOMPATIBILITY.
   437 
   438 * Dropped several real-specific versions of lemmas about floor and
   439 ceiling; use the generic lemmas from theory "Archimedean_Field"
   440 instead.  INCOMPATIBILITY.
   441 
   442   floor_number_of_eq         ~> floor_number_of
   443   le_floor_eq_number_of      ~> number_of_le_floor
   444   le_floor_eq_zero           ~> zero_le_floor
   445   le_floor_eq_one            ~> one_le_floor
   446   floor_less_eq_number_of    ~> floor_less_number_of
   447   floor_less_eq_zero         ~> floor_less_zero
   448   floor_less_eq_one          ~> floor_less_one
   449   less_floor_eq_number_of    ~> number_of_less_floor
   450   less_floor_eq_zero         ~> zero_less_floor
   451   less_floor_eq_one          ~> one_less_floor
   452   floor_le_eq_number_of      ~> floor_le_number_of
   453   floor_le_eq_zero           ~> floor_le_zero
   454   floor_le_eq_one            ~> floor_le_one
   455   floor_subtract_number_of   ~> floor_diff_number_of
   456   floor_subtract_one         ~> floor_diff_one
   457   ceiling_number_of_eq       ~> ceiling_number_of
   458   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   459   ceiling_le_zero_eq         ~> ceiling_le_zero
   460   ceiling_le_eq_one          ~> ceiling_le_one
   461   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   462   less_ceiling_eq_zero       ~> zero_less_ceiling
   463   less_ceiling_eq_one        ~> one_less_ceiling
   464   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   465   ceiling_less_eq_zero       ~> ceiling_less_zero
   466   ceiling_less_eq_one        ~> ceiling_less_one
   467   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   468   le_ceiling_eq_zero         ~> zero_le_ceiling
   469   le_ceiling_eq_one          ~> one_le_ceiling
   470   ceiling_subtract_number_of ~> ceiling_diff_number_of
   471   ceiling_subtract_one       ~> ceiling_diff_one
   472 
   473 * Theory "Finite_Set": various folding_XXX locales facilitate the
   474 application of the various fold combinators on finite sets.
   475 
   476 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   477 provides abstract red-black tree type which is backed by "RBT_Impl" as
   478 implementation.  INCOMPATIBILTY.
   479 
   480 * Theory Library/Coinductive_List has been removed -- superseded by
   481 AFP/thys/Coinductive.
   482 
   483 * Theory PReal, including the type "preal" and related operations, has
   484 been removed.  INCOMPATIBILITY.
   485 
   486 * Real: new development using Cauchy Sequences.
   487 
   488 * Split off theory "Big_Operators" containing setsum, setprod,
   489 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   490 
   491 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   492 "Int" etc.  INCOMPATIBILITY.
   493 
   494 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   495 
   496 * New set of rules "ac_simps" provides combined assoc / commute
   497 rewrites for all interpretations of the appropriate generic locales.
   498 
   499 * Renamed theory "OrderedGroup" to "Groups" and split theory
   500 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   501 appropriate and more consistent names suitable for name prefixes
   502 within the HOL theories.  INCOMPATIBILITY.
   503 
   504 * Some generic constants have been put to appropriate theories:
   505   - less_eq, less: Orderings
   506   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   507   - inverse, divide: Rings
   508 INCOMPATIBILITY.
   509 
   510 * More consistent naming of type classes involving orderings (and
   511 lattices):
   512 
   513     lower_semilattice                   ~> semilattice_inf
   514     upper_semilattice                   ~> semilattice_sup
   515 
   516     dense_linear_order                  ~> dense_linorder
   517 
   518     pordered_ab_group_add               ~> ordered_ab_group_add
   519     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   520     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   521     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   522     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   523     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   524     pordered_cancel_semiring            ~> ordered_cancel_semiring
   525     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   526     pordered_comm_ring                  ~> ordered_comm_ring
   527     pordered_comm_semiring              ~> ordered_comm_semiring
   528     pordered_ring                       ~> ordered_ring
   529     pordered_ring_abs                   ~> ordered_ring_abs
   530     pordered_semiring                   ~> ordered_semiring
   531 
   532     ordered_ab_group_add                ~> linordered_ab_group_add
   533     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   534     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   535     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   536     ordered_field                       ~> linordered_field
   537     ordered_field_no_lb                 ~> linordered_field_no_lb
   538     ordered_field_no_ub                 ~> linordered_field_no_ub
   539     ordered_field_dense_linear_order    ~> dense_linordered_field
   540     ordered_idom                        ~> linordered_idom
   541     ordered_ring                        ~> linordered_ring
   542     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   543     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   544     ordered_ring_strict                 ~> linordered_ring_strict
   545     ordered_semidom                     ~> linordered_semidom
   546     ordered_semiring                    ~> linordered_semiring
   547     ordered_semiring_1                  ~> linordered_semiring_1
   548     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   549     ordered_semiring_strict             ~> linordered_semiring_strict
   550 
   551   The following slightly odd type classes have been moved to a
   552   separate theory Library/Lattice_Algebras:
   553 
   554     lordered_ab_group_add               ~> lattice_ab_group_add
   555     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   556     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   557     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   558     lordered_ring                       ~> lattice_ring
   559 
   560 INCOMPATIBILITY.
   561 
   562 * Refined field classes:
   563   - classes division_ring_inverse_zero, field_inverse_zero,
   564     linordered_field_inverse_zero include rule inverse 0 = 0 --
   565     subsumes former division_by_zero class;
   566   - numerous lemmas have been ported from field to division_ring.
   567 INCOMPATIBILITY.
   568 
   569 * Refined algebra theorem collections:
   570   - dropped theorem group group_simps, use algebra_simps instead;
   571   - dropped theorem group ring_simps, use field_simps instead;
   572   - proper theorem collection field_simps subsumes former theorem
   573     groups field_eq_simps and field_simps;
   574   - dropped lemma eq_minus_self_iff which is a duplicate for
   575     equal_neg_zero.
   576 INCOMPATIBILITY.
   577 
   578 * Theory Finite_Set and List: some lemmas have been generalized from
   579 sets to lattices:
   580 
   581   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   582   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   583   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   584   union_Union_fold_union        ~> sup_Sup_fold_sup
   585   Inter_fold_inter              ~> Inf_fold_inf
   586   Union_fold_union              ~> Sup_fold_sup
   587   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   588   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   589   INTER_fold_inter              ~> INFI_fold_inf
   590   UNION_fold_union              ~> SUPR_fold_sup
   591 
   592 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   593 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   594 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   595 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   596 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   597 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   598 
   599 * Reorganized theory Multiset: swapped notation of pointwise and
   600 multiset order:
   601 
   602   - pointwise ordering is instance of class order with standard syntax
   603     <= and <;
   604   - multiset ordering has syntax <=# and <#; partial order properties
   605     are provided by means of interpretation with prefix
   606     multiset_order;
   607   - less duplication, less historical organization of sections,
   608     conversion from associations lists to multisets, rudimentary code
   609     generation;
   610   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   611     if needed.
   612 
   613 Renamed:
   614 
   615   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   616   multi_count_ext  ~>  multiset_ext
   617   diff_union_inverse2  ~>  diff_union_cancelR
   618 
   619 INCOMPATIBILITY.
   620 
   621 * Theory Permutation: replaced local "remove" by List.remove1.
   622 
   623 * Code generation: ML and OCaml code is decorated with signatures.
   624 
   625 * Theory List: added transpose.
   626 
   627 * Library/Nat_Bijection.thy is a collection of bijective functions
   628 between nat and other types, which supersedes the older libraries
   629 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   630 
   631   Constants:
   632   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   633   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   634   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   635   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   636   Countable.pair_encode           ~> prod_encode
   637   NatIso.prod2nat                 ~> prod_encode
   638   NatIso.nat2prod                 ~> prod_decode
   639   NatIso.sum2nat                  ~> sum_encode
   640   NatIso.nat2sum                  ~> sum_decode
   641   NatIso.list2nat                 ~> list_encode
   642   NatIso.nat2list                 ~> list_decode
   643   NatIso.set2nat                  ~> set_encode
   644   NatIso.nat2set                  ~> set_decode
   645 
   646   Lemmas:
   647   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   648   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   649   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   650   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   651   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   652   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   653   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   654   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   655   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   656   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   657   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   658   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   659   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   660 
   661 * Sledgehammer:
   662   - Renamed ATP commands:
   663     atp_info     ~> sledgehammer running_atps
   664     atp_kill     ~> sledgehammer kill_atps
   665     atp_messages ~> sledgehammer messages
   666     atp_minimize ~> sledgehammer minimize
   667     print_atps   ~> sledgehammer available_atps
   668     INCOMPATIBILITY.
   669   - Added user's manual ("isabelle doc sledgehammer").
   670   - Added option syntax and "sledgehammer_params" to customize
   671     Sledgehammer's behavior.  See the manual for details.
   672   - Modified the Isar proof reconstruction code so that it produces
   673     direct proofs rather than proofs by contradiction.  (This feature
   674     is still experimental.)
   675   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   676     full-typed mode.
   677   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   678 
   679 * Nitpick:
   680   - Added and implemented "binary_ints" and "bits" options.
   681   - Added "std" option and implemented support for nonstandard models.
   682   - Added and implemented "finitize" option to improve the precision
   683     of infinite datatypes based on a monotonicity analysis.
   684   - Added support for quotient types.
   685   - Added support for "specification" and "ax_specification"
   686     constructs.
   687   - Added support for local definitions (for "function" and
   688     "termination" proofs).
   689   - Added support for term postprocessors.
   690   - Optimized "Multiset.multiset" and "FinFun.finfun".
   691   - Improved efficiency of "destroy_constrs" optimization.
   692   - Fixed soundness bugs related to "destroy_constrs" optimization and
   693     record getters.
   694   - Fixed soundness bug related to higher-order constructors.
   695   - Fixed soundness bug when "full_descrs" is enabled.
   696   - Improved precision of set constructs.
   697   - Added "atoms" option.
   698   - Added cache to speed up repeated Kodkod invocations on the same
   699     problems.
   700   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   701     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   702     "SAT4J_Light".  INCOMPATIBILITY.
   703   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   704     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   705   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   706 
   707 * Method "induct" now takes instantiations of the form t, where t is not
   708   a variable, as a shorthand for "x == t", where x is a fresh variable.
   709   If this is not intended, t has to be enclosed in parentheses.
   710   By default, the equalities generated by definitional instantiations
   711   are pre-simplified, which may cause parameters of inductive cases
   712   to disappear, or may even delete some of the inductive cases.
   713   Use "induct (no_simp)" instead of "induct" to restore the old
   714   behaviour. The (no_simp) option is also understood by the "cases"
   715   and "nominal_induct" methods, which now perform pre-simplification, too.
   716   INCOMPATIBILITY.
   717 
   718 
   719 *** HOLCF ***
   720 
   721 * Variable names in lemmas generated by the domain package have
   722 changed; the naming scheme is now consistent with the HOL datatype
   723 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   724 
   725 * The domain package no longer defines the function "foo_copy" for
   726 recursive domain "foo".  The reach lemma is now stated directly in
   727 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   728 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   729 
   730 * Most definedness lemmas generated by the domain package (previously
   731 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   732 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   733 Proofs that used definedness lemmas as intro rules may break,
   734 potential INCOMPATIBILITY.
   735 
   736 * Induction and casedist rules generated by the domain package now
   737 declare proper case_names (one called "bottom", and one named for each
   738 constructor).  INCOMPATIBILITY.
   739 
   740 * For mutually-recursive domains, separate "reach" and "take_lemma"
   741 rules are generated for each domain, INCOMPATIBILITY.
   742 
   743   foo_bar.reach       ~> foo.reach  bar.reach
   744   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   745 
   746 * Some lemmas generated by the domain package have been renamed for
   747 consistency with the datatype package, INCOMPATIBILITY.
   748 
   749   foo.ind        ~> foo.induct
   750   foo.finite_ind ~> foo.finite_induct
   751   foo.coind      ~> foo.coinduct
   752   foo.casedist   ~> foo.exhaust
   753   foo.exhaust    ~> foo.nchotomy
   754 
   755 * For consistency with other definition packages, the fixrec package
   756 now generates qualified theorem names, INCOMPATIBILITY.
   757 
   758   foo_simps  ~> foo.simps
   759   foo_unfold ~> foo.unfold
   760   foo_induct ~> foo.induct
   761 
   762 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   763 method and internal fixrec proofs now use the default simpset instead.
   764 INCOMPATIBILITY.
   765 
   766 * The "contlub" predicate has been removed.  Proof scripts should use
   767 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   768 
   769 * The "admw" predicate has been removed, INCOMPATIBILITY.
   770 
   771 * The constants cpair, cfst, and csnd have been removed in favor of
   772 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   773 
   774 
   775 *** ML ***
   776 
   777 * Antiquotations for basic formal entities:
   778 
   779     @{class NAME}         -- type class
   780     @{class_syntax NAME}  -- syntax representation of the above
   781 
   782     @{type_name NAME}     -- logical type
   783     @{type_abbrev NAME}   -- type abbreviation
   784     @{nonterminal NAME}   -- type of concrete syntactic category
   785     @{type_syntax NAME}   -- syntax representation of any of the above
   786 
   787     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   788     @{const_abbrev NAME}  -- abbreviated constant
   789     @{const_syntax NAME}  -- syntax representation of any of the above
   790 
   791 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   792 syntax constant (cf. 'syntax' command).
   793 
   794 * Antiquotation @{make_string} inlines a function to print arbitrary
   795 values similar to the ML toplevel.  The result is compiler dependent
   796 and may fall back on "?" in certain situations.
   797 
   798 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   799 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   800 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   801 not work with the asynchronous Isar document model.
   802 
   803 * Configuration options now admit dynamic default values, depending on
   804 the context or even global references.
   805 
   806 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   807 uses an efficient external library if available (for Poly/ML).
   808 
   809 * Renamed some important ML structures, while keeping the old names
   810 for some time as aliases within the structure Legacy:
   811 
   812   OuterKeyword  ~>  Keyword
   813   OuterLex      ~>  Token
   814   OuterParse    ~>  Parse
   815   OuterSyntax   ~>  Outer_Syntax
   816   PrintMode     ~>  Print_Mode
   817   SpecParse     ~>  Parse_Spec
   818   ThyInfo       ~>  Thy_Info
   819   ThyLoad       ~>  Thy_Load
   820   ThyOutput     ~>  Thy_Output
   821   TypeInfer     ~>  Type_Infer
   822 
   823 Note that "open Legacy" simplifies porting of sources, but forgetting
   824 to remove it again will complicate porting again in the future.
   825 
   826 * Most operations that refer to a global context are named
   827 accordingly, e.g. Simplifier.global_context or
   828 ProofContext.init_global.  There are some situations where a global
   829 context actually works, but under normal circumstances one needs to
   830 pass the proper local context through the code!
   831 
   832 * Discontinued old TheoryDataFun with its copy/init operation -- data
   833 needs to be pure.  Functor Theory_Data_PP retains the traditional
   834 Pretty.pp argument to merge, which is absent in the standard
   835 Theory_Data version.
   836 
   837 * Sorts.certify_sort and derived "cert" operations for types and terms
   838 no longer minimize sorts.  Thus certification at the boundary of the
   839 inference kernel becomes invariant under addition of class relations,
   840 which is an important monotonicity principle.  Sorts are now minimized
   841 in the syntax layer only, at the boundary between the end-user and the
   842 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   843 explicitly in rare situations.
   844 
   845 * Renamed old-style Drule.standard to Drule.export_without_context, to
   846 emphasize that this is in no way a standard operation.
   847 INCOMPATIBILITY.
   848 
   849 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   850 usual for resolution.  Rare INCOMPATIBILITY.
   851 
   852 * Renamed varify/unvarify operations to varify_global/unvarify_global
   853 to emphasize that these only work in a global situation (which is
   854 quite rare).
   855 
   856 * Curried take and drop in library.ML; negative length is interpreted
   857 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   858 
   859 * Proof terms: type substitutions on proof constants now use canonical
   860 order of type variables.  INCOMPATIBILITY for tools working with proof
   861 terms.
   862 
   863 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   864 may no longer carry premises.  User-level specifications are
   865 transformed accordingly by Thm.add_axiom/add_def.
   866 
   867 
   868 *** System ***
   869 
   870 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   871 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   872 proof terms are enabled unconditionally in the new HOL-Proofs image.
   873 
   874 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   875 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   876 respectively.
   877 
   878 * Old lib/scripts/polyml-platform is superseded by the
   879 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   880 variant, even on a 64 bit machine.  The following example setting
   881 prefers 64 bit if available:
   882 
   883   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   884 
   885 * The preliminary Isabelle/jEdit application demonstrates the emerging
   886 Isabelle/Scala layer for advanced prover interaction and integration.
   887 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   888 component.
   889 
   890 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   891 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   892 similar to the default assignment of the document preparation system
   893 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   894 provides some operations for direct access to the font without asking
   895 the user for manual installation.
   896 
   897 
   898 
   899 New in Isabelle2009-1 (December 2009)
   900 -------------------------------------
   901 
   902 *** General ***
   903 
   904 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   905 one backslash should be used, even in ML sources.
   906 
   907 
   908 *** Pure ***
   909 
   910 * Locale interpretation propagates mixins along the locale hierarchy.
   911 The currently only available mixins are the equations used to map
   912 local definitions to terms of the target domain of an interpretation.
   913 
   914 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   915 loc" to print all interpretations of locale "loc" in the theory.
   916 Interpretations in proofs are not shown.
   917 
   918 * Thoroughly revised locales tutorial.  New section on conditional
   919 interpretation.
   920 
   921 * On instantiation of classes, remaining undefined class parameters
   922 are formally declared.  INCOMPATIBILITY.
   923 
   924 
   925 *** Document preparation ***
   926 
   927 * New generalized style concept for printing terms: @{foo (style) ...}
   928 instead of @{foo_style style ...}  (old form is still retained for
   929 backward compatibility).  Styles can be also applied for
   930 antiquotations prop, term_type and typeof.
   931 
   932 
   933 *** HOL ***
   934 
   935 * New proof method "smt" for a combination of first-order logic with
   936 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   937 fixed-size bitvectors; there is also basic support for higher-order
   938 features (esp. lambda abstractions).  It is an incomplete decision
   939 procedure based on external SMT solvers using the oracle mechanism;
   940 for the SMT solver Z3, this method is proof-producing.  Certificates
   941 are provided to avoid calling the external solvers solely for
   942 re-checking proofs.  Due to a remote SMT service there is no need for
   943 installing SMT solvers locally.  See src/HOL/SMT.
   944 
   945 * New commands to load and prove verification conditions generated by
   946 the Boogie program verifier or derived systems (e.g. the Verifying C
   947 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   948 
   949 * New counterexample generator tool 'nitpick' based on the Kodkod
   950 relational model finder.  See src/HOL/Tools/Nitpick and
   951 src/HOL/Nitpick_Examples.
   952 
   953 * New commands 'code_pred' and 'values' to invoke the predicate
   954 compiler and to enumerate values of inductive predicates.
   955 
   956 * A tabled implementation of the reflexive transitive closure.
   957 
   958 * New implementation of quickcheck uses generic code generator;
   959 default generators are provided for all suitable HOL types, records
   960 and datatypes.  Old quickcheck can be re-activated importing theory
   961 Library/SML_Quickcheck.
   962 
   963 * New testing tool Mirabelle for automated proof tools.  Applies
   964 several tools and tactics like sledgehammer, metis, or quickcheck, to
   965 every proof step in a theory.  To be used in batch mode via the
   966 "mirabelle" utility.
   967 
   968 * New proof method "sos" (sum of squares) for nonlinear real
   969 arithmetic (originally due to John Harison). It requires theory
   970 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   971 works well in practice on quantifier-free real arithmetic with +, -,
   972 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   973 inequalities between polynomials.  It makes use of external
   974 semidefinite programming solvers.  Method "sos" generates a
   975 certificate that can be pasted into the proof thus avoiding the need
   976 to call an external tool every time the proof is checked.  See
   977 src/HOL/Library/Sum_Of_Squares.
   978 
   979 * New method "linarith" invokes existing linear arithmetic decision
   980 procedure only.
   981 
   982 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   983 
   984 * New Sledgehammer option "Full Types" in Proof General settings menu.
   985 Causes full type information to be output to the ATPs.  This slows
   986 ATPs down considerably but eliminates a source of unsound "proofs"
   987 that fail later.
   988 
   989 * New method "metisFT": A version of metis that uses full type
   990 information in order to avoid failures of proof reconstruction.
   991 
   992 * New evaluator "approximate" approximates an real valued term using
   993 the same method as the approximation method.
   994 
   995 * Method "approximate" now supports arithmetic expressions as
   996 boundaries of intervals and implements interval splitting and Taylor
   997 series expansion.
   998 
   999 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1000 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1001 
  1002 * New theory SupInf of the supremum and infimum operators for sets of
  1003 reals.
  1004 
  1005 * New theory Probability, which contains a development of measure
  1006 theory, eventually leading to Lebesgue integration and probability.
  1007 
  1008 * Extended Multivariate Analysis to include derivation and Brouwer's
  1009 fixpoint theorem.
  1010 
  1011 * Reorganization of number theory, INCOMPATIBILITY:
  1012   - new number theory development for nat and int, in theories Divides
  1013     and GCD as well as in new session Number_Theory
  1014   - some constants and facts now suffixed with _nat and _int
  1015     accordingly
  1016   - former session NumberTheory now named Old_Number_Theory, including
  1017     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1018   - moved theory Pocklington from src/HOL/Library to
  1019     src/HOL/Old_Number_Theory
  1020 
  1021 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1022 lcm of finite and infinite sets. It is shown that they form a complete
  1023 lattice.
  1024 
  1025 * Class semiring_div requires superclass no_zero_divisors and proof of
  1026 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1027 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1028 generalized to class semiring_div, subsuming former theorems
  1029 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1030 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1031 INCOMPATIBILITY.
  1032 
  1033 * Refinements to lattice classes and sets:
  1034   - less default intro/elim rules in locale variant, more default
  1035     intro/elim rules in class variant: more uniformity
  1036   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1037     le_inf_iff
  1038   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1039     sup_aci)
  1040   - renamed ACI to inf_sup_aci
  1041   - new class "boolean_algebra"
  1042   - class "complete_lattice" moved to separate theory
  1043     "Complete_Lattice"; corresponding constants (and abbreviations)
  1044     renamed and with authentic syntax:
  1045     Set.Inf ~>    Complete_Lattice.Inf
  1046     Set.Sup ~>    Complete_Lattice.Sup
  1047     Set.INFI ~>   Complete_Lattice.INFI
  1048     Set.SUPR ~>   Complete_Lattice.SUPR
  1049     Set.Inter ~>  Complete_Lattice.Inter
  1050     Set.Union ~>  Complete_Lattice.Union
  1051     Set.INTER ~>  Complete_Lattice.INTER
  1052     Set.UNION ~>  Complete_Lattice.UNION
  1053   - authentic syntax for
  1054     Set.Pow
  1055     Set.image
  1056   - mere abbreviations:
  1057     Set.empty               (for bot)
  1058     Set.UNIV                (for top)
  1059     Set.inter               (for inf, formerly Set.Int)
  1060     Set.union               (for sup, formerly Set.Un)
  1061     Complete_Lattice.Inter  (for Inf)
  1062     Complete_Lattice.Union  (for Sup)
  1063     Complete_Lattice.INTER  (for INFI)
  1064     Complete_Lattice.UNION  (for SUPR)
  1065   - object-logic definitions as far as appropriate
  1066 
  1067 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1068 Un_subset_iff are explicitly deleted as default simp rules; then also
  1069 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1070 deleted to achieve the desired effect.
  1071 
  1072 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1073 rules by default any longer; the same applies to min_max.inf_absorb1
  1074 etc.  INCOMPATIBILITY.
  1075 
  1076 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1077 pred_set_conv by default.  INCOMPATIBILITY.
  1078 
  1079 * Power operations on relations and functions are now one dedicated
  1080 constant "compow" with infix syntax "^^".  Power operation on
  1081 multiplicative monoids retains syntax "^" and is now defined generic
  1082 in class power.  INCOMPATIBILITY.
  1083 
  1084 * Relation composition "R O S" now has a more standard argument order:
  1085 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1086 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1087 break, since the O_assoc rule was not rewritten like this.  Fix using
  1088 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1089 
  1090 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1091 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1092 INCOMPATIBILITY.
  1093 
  1094 * Most rules produced by inductive and datatype package have mandatory
  1095 prefixes.  INCOMPATIBILITY.
  1096 
  1097 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1098 the attribute of the same name.  Each of the theorems in the list
  1099 DERIV_intros assumes composition with an additional function and
  1100 matches a variable to the derivative, which has to be solved by the
  1101 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1102 of most elementary terms.  Former Maclauren.DERIV_tac and
  1103 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1104 INCOMPATIBILITY.
  1105 
  1106 * Code generator attributes follow the usual underscore convention:
  1107     code_unfold     replaces    code unfold
  1108     code_post       replaces    code post
  1109     etc.
  1110   INCOMPATIBILITY.
  1111 
  1112 * Renamed methods:
  1113     sizechange -> size_change
  1114     induct_scheme -> induction_schema
  1115   INCOMPATIBILITY.
  1116 
  1117 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1118 INCOMPATIBILITY, use "undefined" directly.
  1119 
  1120 * Renamed theorems:
  1121     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1122     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1123     Suc_plus1 -> Suc_eq_plus1
  1124     *anti_sym -> *antisym*
  1125     vector_less_eq_def -> vector_le_def
  1126   INCOMPATIBILITY.
  1127 
  1128 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1129 INCOMPATIBILITY.
  1130 
  1131 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1132 INCOMPATIBILITY.
  1133 
  1134 
  1135 *** HOLCF ***
  1136 
  1137 * Theory Representable defines a class "rep" of domains that are
  1138 representable (via an ep-pair) in the universal domain type "udom".
  1139 Instances are provided for all type constructors defined in HOLCF.
  1140 
  1141 * The 'new_domain' command is a purely definitional version of the
  1142 domain package, for representable domains.  Syntax is identical to the
  1143 old domain package.  The 'new_domain' package also supports indirect
  1144 recursion using previously-defined type constructors.  See
  1145 src/HOLCF/ex/New_Domain.thy for examples.
  1146 
  1147 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1148 on the left-hand side of an equation, and then performs
  1149 simplification.  Rewriting is done using rules declared with the
  1150 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1151 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1152 
  1153 * The pattern-match compiler in 'fixrec' can now handle constructors
  1154 with HOL function types.  Pattern-match combinators for the Pair
  1155 constructor are pre-configured.
  1156 
  1157 * The 'fixrec' package now produces better fixed-point induction rules
  1158 for mutually-recursive definitions:  Induction rules have conclusions
  1159 of the form "P foo bar" instead of "P <foo, bar>".
  1160 
  1161 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1162 been renamed to "below".  The name "below" now replaces "less" in many
  1163 theorem names.  (Legacy theorem names using "less" are still supported
  1164 as well.)
  1165 
  1166 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1167 patterns can be used to generate strictness rules, or to make
  1168 functions more strict (much like the bang-patterns supported by the
  1169 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1170 examples.
  1171 
  1172 
  1173 *** ML ***
  1174 
  1175 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1176 errors and run-time exceptions, including detailed source positions.
  1177 
  1178 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1179 identified entries, with some additional information such as source
  1180 position, logical grouping etc.
  1181 
  1182 * Theory and context data is now introduced by the simplified and
  1183 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1184 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1185 copy operation) is still available for some time.
  1186 
  1187 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1188 provides a high-level programming interface to synchronized state
  1189 variables with atomic update.  This works via pure function
  1190 application within a critical section -- its runtime should be as
  1191 short as possible; beware of deadlocks if critical code is nested,
  1192 either directly or indirectly via other synchronized variables!
  1193 
  1194 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1195 wraps raw ML references, explicitly indicating their non-thread-safe
  1196 behaviour.  The Isar toplevel keeps this structure open, to
  1197 accommodate Proof General as well as quick and dirty interactive
  1198 experiments with references.
  1199 
  1200 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1201 parallel tactical reasoning.
  1202 
  1203 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1204 are similar to SUBPROOF, but are slightly more flexible: only the
  1205 specified parts of the subgoal are imported into the context, and the
  1206 body tactic may introduce new subgoals and schematic variables.
  1207 
  1208 * Old tactical METAHYPS, which does not observe the proof context, has
  1209 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1210 or Subgoal.FOCUS etc.
  1211 
  1212 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1213 functors have their own ML name space there is no point to mark them
  1214 separately.)  Minor INCOMPATIBILITY.
  1215 
  1216 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1217 
  1218 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1219 INCOMPATIBILITY.
  1220 
  1221 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1222 mode, which avoids critical setmp.
  1223 
  1224 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1225 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1226 Attrib/Method.setup introduced in Isabelle2009.
  1227 
  1228 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1229 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1230 last resort.  INCOMPATIBILITY.
  1231 
  1232 * Display.pretty_thm now requires a proper context (cf. former
  1233 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1234 or even Display.pretty_thm_without_context as last resort.
  1235 INCOMPATIBILITY.
  1236 
  1237 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1238 Syntax.pretty_typ/term directly, preferably with proper context
  1239 instead of global theory.
  1240 
  1241 
  1242 *** System ***
  1243 
  1244 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1245 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1246 usedir option -q.
  1247 
  1248 * Support for additional "Isabelle components" via etc/components, see
  1249 also the system manual.
  1250 
  1251 * The isabelle makeall tool now operates on all components with
  1252 IsaMakefile, not just hardwired "logics".
  1253 
  1254 * Removed "compress" option from isabelle-process and isabelle usedir;
  1255 this is always enabled.
  1256 
  1257 * Discontinued support for Poly/ML 4.x versions.
  1258 
  1259 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1260 on a given logic image.  This requires the lighttpd webserver and is
  1261 currently supported on Linux only.
  1262 
  1263 
  1264 
  1265 New in Isabelle2009 (April 2009)
  1266 --------------------------------
  1267 
  1268 *** General ***
  1269 
  1270 * Simplified main Isabelle executables, with less surprises on
  1271 case-insensitive file-systems (such as Mac OS).
  1272 
  1273   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1274     "isatool."
  1275 
  1276   - The former "isabelle" alias for "isabelle-process" has been
  1277     removed (should rarely occur to regular users).
  1278 
  1279   - The former "isabelle-interface" and its alias "Isabelle" have been
  1280     removed (interfaces are now regular Isabelle tools).
  1281 
  1282 Within scripts and make files, the Isabelle environment variables
  1283 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1284 respectively.  (The latter are still available as legacy feature.)
  1285 
  1286 The old isabelle-interface wrapper could react in confusing ways if
  1287 the interface was uninstalled or changed otherwise.  Individual
  1288 interface tool configuration is now more explicit, see also the
  1289 Isabelle system manual.  In particular, Proof General is now available
  1290 via "isabelle emacs".
  1291 
  1292 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1293 purge installed copies of Isabelle executables and re-run "isabelle
  1294 install -p ...", or use symlinks.
  1295 
  1296 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1297 old ~/isabelle, which was slightly non-standard and apt to cause
  1298 surprises on case-insensitive file-systems (such as Mac OS).
  1299 
  1300 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1301 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1302 care is required when using older releases of Isabelle.  Note that
  1303 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1304 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1305 
  1306 * Proofs of fully specified statements are run in parallel on
  1307 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1308 a regular 4-core machine, if the initial heap space is made reasonably
  1309 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1310 
  1311 * The main reference manuals ("isar-ref", "implementation", and
  1312 "system") have been updated and extended.  Formally checked references
  1313 as hyperlinks are now available uniformly.
  1314 
  1315 
  1316 *** Pure ***
  1317 
  1318 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1319 respects.  The most important changes are listed below.  See the
  1320 Tutorial on Locales ("locales" manual) for details.
  1321 
  1322 - In locale expressions, instantiation replaces renaming.  Parameters
  1323 must be declared in a for clause.  To aid compatibility with previous
  1324 parameter inheritance, in locale declarations, parameters that are not
  1325 'touched' (instantiation position "_" or omitted) are implicitly added
  1326 with their syntax at the beginning of the for clause.
  1327 
  1328 - Syntax from abbreviations and definitions in locales is available in
  1329 locale expressions and context elements.  The latter is particularly
  1330 useful in locale declarations.
  1331 
  1332 - More flexible mechanisms to qualify names generated by locale
  1333 expressions.  Qualifiers (prefixes) may be specified in locale
  1334 expressions, and can be marked as mandatory (syntax: "name!:") or
  1335 optional (syntax "name?:").  The default depends for plain "name:"
  1336 depends on the situation where a locale expression is used: in
  1337 commands 'locale' and 'sublocale' prefixes are optional, in
  1338 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1339 implicit qualifiers derived from the parameter names of a locale are
  1340 no longer generated.
  1341 
  1342 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1343 instantiation clause in "interpretation" and "interpret" (square
  1344 brackets) is no longer available.  Use locale expressions.
  1345 
  1346 - When converting proof scripts, mandatory qualifiers in
  1347 'interpretation' and 'interpret' should be retained by default, even
  1348 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1349 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1350 in locale expressions range over a single locale instance only.
  1351 
  1352 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1353 In existing theorem specifications replace the includes element by the
  1354 respective context elements of the included locale, omitting those
  1355 that are already present in the theorem specification.  Multiple
  1356 assume elements of a locale should be replaced by a single one
  1357 involving the locale predicate.  In the proof body, declarations (most
  1358 notably theorems) may be regained by interpreting the respective
  1359 locales in the proof context as required (command "interpret").
  1360 
  1361 If using "includes" in replacement of a target solely because the
  1362 parameter types in the theorem are not as general as in the target,
  1363 consider declaring a new locale with additional type constraints on
  1364 the parameters (context element "constrains").
  1365 
  1366 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1367 
  1368 - Locale interpretation commands no longer attempt to simplify goal.
  1369 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1370 methods intro_locales and unfold_locales to clarify.
  1371 
  1372 - Locale interpretation commands no longer accept interpretation
  1373 attributes.  INCOMPATIBILITY.
  1374 
  1375 * Class declaration: so-called "base sort" must not be given in import
  1376 list any longer, but is inferred from the specification.  Particularly
  1377 in HOL, write
  1378 
  1379     class foo = ...
  1380 
  1381 instead of
  1382 
  1383     class foo = type + ...
  1384 
  1385 * Class target: global versions of theorems stemming do not carry a
  1386 parameter prefix any longer.  INCOMPATIBILITY.
  1387 
  1388 * Class 'instance' command no longer accepts attached definitions.
  1389 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1390 
  1391 * Recovered hiding of consts, which was accidentally broken in
  1392 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1393 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1394 
  1395 * Slightly more coherent Pure syntax, with updated documentation in
  1396 isar-ref manual.  Removed locales meta_term_syntax and
  1397 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1398 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1399 directly in regular applications.
  1400 
  1401 * There is a new syntactic category "float_const" for signed decimal
  1402 fractions (e.g. 123.45 or -123.45).
  1403 
  1404 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1405 interface with 'setup' command instead.
  1406 
  1407 * Command 'local_setup' is similar to 'setup', but operates on a local
  1408 theory context.
  1409 
  1410 * The 'axiomatization' command now only works within a global theory
  1411 context.  INCOMPATIBILITY.
  1412 
  1413 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1414 hypotheses.  Sorts required in the course of reasoning need to be
  1415 covered by the constraints in the initial statement, completed by the
  1416 type instance information of the background theory.  Non-trivial sort
  1417 hypotheses, which rarely occur in practice, may be specified via
  1418 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1419 
  1420   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1421 
  1422 The result contains an implicit sort hypotheses as before --
  1423 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1424 normalization.
  1425 
  1426 * Generalized Isar history, with support for linear undo, direct state
  1427 addressing etc.
  1428 
  1429 * Changed defaults for unify configuration options:
  1430 
  1431   unify_trace_bound = 50 (formerly 25)
  1432   unify_search_bound = 60 (formerly 30)
  1433 
  1434 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1435 
  1436   a) On theory merge, the last set of code equations for a particular
  1437      constant is taken (in accordance with the policy applied by other
  1438      parts of the code generator framework).
  1439 
  1440   b) Code equations stemming from explicit declarations (e.g. code
  1441      attribute) gain priority over default code equations stemming
  1442      from definition, primrec, fun etc.
  1443 
  1444 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1445 
  1446 * Unified theorem tables for both code generators.  Thus [code
  1447 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1448 
  1449 * Command 'find_consts' searches for constants based on type and name
  1450 patterns, e.g.
  1451 
  1452     find_consts "_ => bool"
  1453 
  1454 By default, matching is against subtypes, but it may be restricted to
  1455 the whole type.  Searching by name is possible.  Multiple queries are
  1456 conjunctive and queries may be negated by prefixing them with a
  1457 hyphen:
  1458 
  1459     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1460 
  1461 * New 'find_theorems' criterion "solves" matches theorems that
  1462 directly solve the current goal (modulo higher-order unification).
  1463 
  1464 * Auto solve feature for main theorem statements: whenever a new goal
  1465 is stated, "find_theorems solves" is called; any theorems that could
  1466 solve the lemma directly are listed as part of the goal state.
  1467 Cf. associated options in Proof General Isabelle settings menu,
  1468 enabled by default, with reasonable timeout for pathological cases of
  1469 higher-order unification.
  1470 
  1471 
  1472 *** Document preparation ***
  1473 
  1474 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1475 demanding keyword 'by' and supporting the full method expression
  1476 syntax just like the Isar command 'by'.
  1477 
  1478 
  1479 *** HOL ***
  1480 
  1481 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1482 points Main and Complex_Main remain as before.
  1483 
  1484 * Logic image HOL-Plain provides a minimal HOL with the most important
  1485 tools available (inductive, datatype, primrec, ...).  This facilitates
  1486 experimentation and tool development.  Note that user applications
  1487 (and library theories) should never refer to anything below theory
  1488 Main, as before.
  1489 
  1490 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1491 experimentation due to shorter build times.
  1492 
  1493 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1494 were previously part of former HOL-Complex.  Entry point Hyperreal
  1495 remains valid, but theories formerly using Complex_Main should now use
  1496 new entry point Hypercomplex.
  1497 
  1498 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1499 Posix processes.  Avoids potentially expensive forking of the ML
  1500 process.  New thread-based implementation also works on non-Unix
  1501 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1502 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1503 commands are covered in the isar-ref manual.
  1504 
  1505 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1506 sledgehammer without local ATP installation (Vampire etc.). Other
  1507 provers may be included via suitable ML wrappers, see also
  1508 src/HOL/ATP_Linkup.thy.
  1509 
  1510 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1511 menu.
  1512 
  1513 * The metis method no longer fails because the theorem is too trivial
  1514 (contains the empty clause).
  1515 
  1516 * The metis method now fails in the usual manner, rather than raising
  1517 an exception, if it determines that it cannot prove the theorem.
  1518 
  1519 * Method "coherent" implements a prover for coherent logic (see also
  1520 src/Tools/coherent.ML).
  1521 
  1522 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1523 "undefined" is the right choice to replace "arbitrary", though
  1524 logically there is no difference.  INCOMPATIBILITY.
  1525 
  1526 * Command "value" now integrates different evaluation mechanisms.  The
  1527 result of the first successful evaluation mechanism is printed.  In
  1528 square brackets a particular named evaluation mechanisms may be
  1529 specified (currently, [SML], [code] or [nbe]).  See further
  1530 src/HOL/ex/Eval_Examples.thy.
  1531 
  1532 * Normalization by evaluation now allows non-leftlinear equations.
  1533 Declare with attribute [code nbe].
  1534 
  1535 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1536 as the structured Isar versions "cases" and "induct", cf. the
  1537 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1538 are now presented as a list of individual projections
  1539 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1540 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1541 rare situations a different rule is selected --- notably nested tuple
  1542 elimination instead of former prod.exhaust: use explicit (case_tac t
  1543 rule: prod.exhaust) here.
  1544 
  1545 * Attributes "cases", "induct", "coinduct" support "del" option.
  1546 
  1547 * Removed fact "case_split_thm", which duplicates "case_split".
  1548 
  1549 * The option datatype has been moved to a new theory Option.  Renamed
  1550 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1551 
  1552 * New predicate "strict_mono" classifies strict functions on partial
  1553 orders.  With strict functions on linear orders, reasoning about
  1554 (in)equalities is facilitated by theorems "strict_mono_eq",
  1555 "strict_mono_less_eq" and "strict_mono_less".
  1556 
  1557 * Some set operations are now proper qualified constants with
  1558 authentic syntax.  INCOMPATIBILITY:
  1559 
  1560     op Int ~>   Set.Int
  1561     op Un ~>    Set.Un
  1562     INTER ~>    Set.INTER
  1563     UNION ~>    Set.UNION
  1564     Inter ~>    Set.Inter
  1565     Union ~>    Set.Union
  1566     {} ~>       Set.empty
  1567     UNIV ~>     Set.UNIV
  1568 
  1569 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1570 theory Set.
  1571 
  1572 * Auxiliary class "itself" has disappeared -- classes without any
  1573 parameter are treated as expected by the 'class' command.
  1574 
  1575 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1576 
  1577 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1578 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1579 
  1580 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1581 method "approximation".  It proves formulas on real values by using
  1582 interval arithmetic.  In the formulas are also the transcendental
  1583 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1584 allowed. For examples see
  1585 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1586 
  1587 * Theory "Reflection" now resides in HOL/Library.
  1588 
  1589 * Entry point to Word library now simply named "Word".
  1590 INCOMPATIBILITY.
  1591 
  1592 * Made source layout more coherent with logical distribution
  1593 structure:
  1594 
  1595     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1596     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1597     src/HOL/Library/GCD.thy ~> src/HOL/
  1598     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1599     src/HOL/Library/Parity.thy ~> src/HOL/
  1600     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1601     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1602     src/HOL/Real/Lubs.thy ~> src/HOL/
  1603     src/HOL/Real/PReal.thy ~> src/HOL/
  1604     src/HOL/Real/Rational.thy ~> src/HOL/
  1605     src/HOL/Real/RComplete.thy ~> src/HOL/
  1606     src/HOL/Real/RealDef.thy ~> src/HOL/
  1607     src/HOL/Real/RealPow.thy ~> src/HOL/
  1608     src/HOL/Real/Real.thy ~> src/HOL/
  1609     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1610     src/HOL/Complex/Complex.thy ~> src/HOL/
  1611     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1612     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1613     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1614     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1615     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1616     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1617     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1618     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1619     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1620     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1621     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1622     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1623     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1624     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1625     src/HOL/Real/Float ~> src/HOL/Library/
  1626     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1627     src/HOL/Real/RealVector.thy ~> src/HOL/
  1628 
  1629     src/HOL/arith_data.ML ~> src/HOL/Tools
  1630     src/HOL/hologic.ML ~> src/HOL/Tools
  1631     src/HOL/simpdata.ML ~> src/HOL/Tools
  1632     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1633     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1634     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1635     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1636     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1637     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1638     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1639 
  1640     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1641     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1642     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1643     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1644     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1645     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1646 
  1647 * If methods "eval" and "evaluation" encounter a structured proof
  1648 state with !!/==>, only the conclusion is evaluated to True (if
  1649 possible), avoiding strange error messages.
  1650 
  1651 * Method "sizechange" automates termination proofs using (a
  1652 modification of) the size-change principle.  Requires SAT solver.  See
  1653 src/HOL/ex/Termination.thy for examples.
  1654 
  1655 * Simplifier: simproc for let expressions now unfolds if bound
  1656 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1657 
  1658 * Method "arith": Linear arithmetic now ignores all inequalities when
  1659 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1660 
  1661 * New attribute "arith" for facts that should always be used
  1662 automatically by arithmetic. It is intended to be used locally in
  1663 proofs, e.g.
  1664 
  1665   assumes [arith]: "x > 0"
  1666 
  1667 Global usage is discouraged because of possible performance impact.
  1668 
  1669 * New classes "top" and "bot" with corresponding operations "top" and
  1670 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1671 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1672 
  1673 * Changed definition lemma "less_fun_def" in order to provide an
  1674 instance for preorders on functions; use lemma "less_le" instead.
  1675 INCOMPATIBILITY.
  1676 
  1677 * Theory Orderings: class "wellorder" moved here, with explicit
  1678 induction rule "less_induct" as assumption.  For instantiation of
  1679 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1680 INCOMPATIBILITY.
  1681 
  1682 * Theory Orderings: added class "preorder" as superclass of "order".
  1683 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1684 etc. slightly changed.  Some theorems named order_class.* now named
  1685 preorder_class.*.
  1686 
  1687 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1688 "diag" to "Id_on".
  1689 
  1690 * Theory Finite_Set: added a new fold combinator of type
  1691 
  1692   ('a => 'b => 'b) => 'b => 'a set => 'b
  1693 
  1694 Occasionally this is more convenient than the old fold combinator
  1695 which is now defined in terms of the new one and renamed to
  1696 fold_image.
  1697 
  1698 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1699 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1700 extended with further lemmas!).  At the moment both still exist but
  1701 the former will disappear at some point.
  1702 
  1703 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1704 class recpower.  Type-specific simp rules for various recpower types
  1705 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1706 
  1707 rat_power_0    -> power_0
  1708 rat_power_Suc  -> power_Suc
  1709 realpow_0      -> power_0
  1710 realpow_Suc    -> power_Suc
  1711 complexpow_0   -> power_0
  1712 complexpow_Suc -> power_Suc
  1713 power_poly_0   -> power_0
  1714 power_poly_Suc -> power_Suc
  1715 
  1716 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1717 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1718 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1719 of lemmas from Divides has been generalized from nat to class
  1720 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1721 renames resulting from duplicate elimination:
  1722 
  1723     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1724     zero_dvd_iff ~>         dvd_0_left_iff
  1725     dvd_0 ~>                dvd_0_right
  1726     DIVISION_BY_ZERO_DIV ~> div_by_0
  1727     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1728     mult_div ~>             div_mult_self2_is_id
  1729     mult_mod ~>             mod_mult_self2_is_0
  1730 
  1731 * Theory IntDiv: removed many lemmas that are instances of class-based
  1732 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1733 rename old lemmas as follows:
  1734 
  1735 dvd_diff               -> nat_dvd_diff
  1736 dvd_zminus_iff         -> dvd_minus_iff
  1737 mod_add1_eq            -> mod_add_eq
  1738 mod_mult1_eq           -> mod_mult_right_eq
  1739 mod_mult1_eq'          -> mod_mult_left_eq
  1740 mod_mult_distrib_mod   -> mod_mult_eq
  1741 nat_mod_add_left_eq    -> mod_add_left_eq
  1742 nat_mod_add_right_eq   -> mod_add_right_eq
  1743 nat_mod_div_trivial    -> mod_div_trivial
  1744 nat_mod_mod_trivial    -> mod_mod_trivial
  1745 zdiv_zadd_self1        -> div_add_self1
  1746 zdiv_zadd_self2        -> div_add_self2
  1747 zdiv_zmult_self1       -> div_mult_self2_is_id
  1748 zdiv_zmult_self2       -> div_mult_self1_is_id
  1749 zdvd_triv_left         -> dvd_triv_left
  1750 zdvd_triv_right        -> dvd_triv_right
  1751 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1752 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1753 zmod_zadd_left_eq      -> mod_add_left_eq
  1754 zmod_zadd_right_eq     -> mod_add_right_eq
  1755 zmod_zadd_self1        -> mod_add_self1
  1756 zmod_zadd_self2        -> mod_add_self2
  1757 zmod_zadd1_eq          -> mod_add_eq
  1758 zmod_zdiff1_eq         -> mod_diff_eq
  1759 zmod_zdvd_zmod         -> mod_mod_cancel
  1760 zmod_zmod_cancel       -> mod_mod_cancel
  1761 zmod_zmult_self1       -> mod_mult_self2_is_0
  1762 zmod_zmult_self2       -> mod_mult_self1_is_0
  1763 zmod_1                 -> mod_by_1
  1764 zdiv_1                 -> div_by_1
  1765 zdvd_abs1              -> abs_dvd_iff
  1766 zdvd_abs2              -> dvd_abs_iff
  1767 zdvd_refl              -> dvd_refl
  1768 zdvd_trans             -> dvd_trans
  1769 zdvd_zadd              -> dvd_add
  1770 zdvd_zdiff             -> dvd_diff
  1771 zdvd_zminus_iff        -> dvd_minus_iff
  1772 zdvd_zminus2_iff       -> minus_dvd_iff
  1773 zdvd_zmultD            -> dvd_mult_right
  1774 zdvd_zmultD2           -> dvd_mult_left
  1775 zdvd_zmult_mono        -> mult_dvd_mono
  1776 zdvd_0_right           -> dvd_0_right
  1777 zdvd_0_left            -> dvd_0_left_iff
  1778 zdvd_1_left            -> one_dvd
  1779 zminus_dvd_iff         -> minus_dvd_iff
  1780 
  1781 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1782 
  1783 * The real numbers offer decimal input syntax: 12.34 is translated
  1784 into 1234/10^2. This translation is not reversed upon output.
  1785 
  1786 * Theory Library/Polynomial defines an abstract type 'a poly of
  1787 univariate polynomials with coefficients of type 'a.  In addition to
  1788 the standard ring operations, it also supports div and mod.  Code
  1789 generation is also supported, using list-style constructors.
  1790 
  1791 * Theory Library/Inner_Product defines a class of real_inner for real
  1792 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1793 => real.  Class real_inner is a subclass of real_normed_vector from
  1794 theory RealVector.
  1795 
  1796 * Theory Library/Product_Vector provides instances for the product
  1797 type 'a * 'b of several classes from RealVector and Inner_Product.
  1798 Definitions of addition, subtraction, scalar multiplication, norms,
  1799 and inner products are included.
  1800 
  1801 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1802 addition to the field operations, numerals and case syntax are also
  1803 supported.
  1804 
  1805 * Theory Library/Diagonalize provides constructive version of Cantor's
  1806 first diagonalization argument.
  1807 
  1808 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1809 zlcm (for int); carried together from various gcd/lcm developements in
  1810 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1811 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1812 may recover tupled syntax as follows:
  1813 
  1814     hide (open) const gcd
  1815     abbreviation gcd where
  1816       "gcd == (%(a, b). GCD.gcd a b)"
  1817     notation (output)
  1818       GCD.gcd ("gcd '(_, _')")
  1819 
  1820 The same works for lcm, zgcd, zlcm.
  1821 
  1822 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1823 instantiations for algebraic structures.  Removed some duplicate
  1824 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1825 
  1826 * ML antiquotation @{code} takes a constant as argument and generates
  1827 corresponding code in background and inserts name of the corresponding
  1828 resulting ML value/function/datatype constructor binding in place.
  1829 All occurrences of @{code} with a single ML block are generated
  1830 simultaneously.  Provides a generic and safe interface for
  1831 instrumentalizing code generation.  See
  1832 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1833 In future you ought to refrain from ad-hoc compiling generated SML
  1834 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1835 cannot refer to constants for which user-defined serializations are
  1836 set.  Refer to the corresponding ML counterpart directly in that
  1837 cases.
  1838 
  1839 * Command 'rep_datatype': instead of theorem names the command now
  1840 takes a list of terms denoting the constructors of the type to be
  1841 represented as datatype.  The characteristic theorems have to be
  1842 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1843 have disappeared in favour of existing ones:
  1844 
  1845     unit_induct                 ~> unit.induct
  1846     prod_induct                 ~> prod.induct
  1847     sum_induct                  ~> sum.induct
  1848     Suc_Suc_eq                  ~> nat.inject
  1849     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1850 
  1851 
  1852 *** HOL-Algebra ***
  1853 
  1854 * New locales for orders and lattices where the equivalence relation
  1855 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1856 locales use a record structure with field eq for the equivalence.
  1857 
  1858 * New theory of factorial domains.
  1859 
  1860 * Units_l_inv and Units_r_inv are now simp rules by default.
  1861 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1862 and/or r_inv will now also require deletion of these lemmas.
  1863 
  1864 * Renamed the following theorems, INCOMPATIBILITY:
  1865 
  1866 UpperD ~> Upper_memD
  1867 LowerD ~> Lower_memD
  1868 least_carrier ~> least_closed
  1869 greatest_carrier ~> greatest_closed
  1870 greatest_Lower_above ~> greatest_Lower_below
  1871 one_zero ~> carrier_one_zero
  1872 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1873 
  1874 
  1875 *** HOL-Nominal ***
  1876 
  1877 * Nominal datatypes can now contain type-variables.
  1878 
  1879 * Commands 'nominal_inductive' and 'equivariance' work with local
  1880 theory targets.
  1881 
  1882 * Nominal primrec can now works with local theory targets and its
  1883 specification syntax now conforms to the general format as seen in
  1884 'inductive' etc.
  1885 
  1886 * Method "perm_simp" honours the standard simplifier attributes
  1887 (no_asm), (no_asm_use) etc.
  1888 
  1889 * The new predicate #* is defined like freshness, except that on the
  1890 left hand side can be a set or list of atoms.
  1891 
  1892 * Experimental command 'nominal_inductive2' derives strong induction
  1893 principles for inductive definitions.  In contrast to
  1894 'nominal_inductive', which can only deal with a fixed number of
  1895 binders, it can deal with arbitrary expressions standing for sets of
  1896 atoms to be avoided.  The only inductive definition we have at the
  1897 moment that needs this generalisation is the typing rule for Lets in
  1898 the algorithm W:
  1899 
  1900  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1901  -----------------------------------------------------------------
  1902          Gamma |- Let x be t1 in t2 : T2
  1903 
  1904 In this rule one wants to avoid all the binders that are introduced by
  1905 "close Gamma T1".  We are looking for other examples where this
  1906 feature might be useful.  Please let us know.
  1907 
  1908 
  1909 *** HOLCF ***
  1910 
  1911 * Reimplemented the simplification procedure for proving continuity
  1912 subgoals.  The new simproc is extensible; users can declare additional
  1913 continuity introduction rules with the attribute [cont2cont].
  1914 
  1915 * The continuity simproc now uses a different introduction rule for
  1916 solving continuity subgoals on terms with lambda abstractions.  In
  1917 some rare cases the new simproc may fail to solve subgoals that the
  1918 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1919 Potential INCOMPATIBILITY.
  1920 
  1921 * Command 'fixrec': specification syntax now conforms to the general
  1922 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1923 examples.  INCOMPATIBILITY.
  1924 
  1925 
  1926 *** ZF ***
  1927 
  1928 * Proof of Zorn's Lemma for partial orders.
  1929 
  1930 
  1931 *** ML ***
  1932 
  1933 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1934 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1935 depends on multithreading, so timouts will not work before Poly/ML
  1936 5.2.1!
  1937 
  1938 * High-level support for concurrent ML programming, see
  1939 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1940 particularly convenient to organize independent functional
  1941 computations.  The concept of "synchronized variables" provides a
  1942 higher-order interface for components with shared state, avoiding the
  1943 delicate details of mutexes and condition variables.  (Requires
  1944 Poly/ML 5.2.1 or later.)
  1945 
  1946 * ML bindings produced via Isar commands are stored within the Isar
  1947 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1948 become thread-safe and work with undo as expected (concerning
  1949 top-level bindings, not side-effects on global references).
  1950 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1951 compiler at runtime; really global bindings need to be given outside a
  1952 theory.  (Requires Poly/ML 5.2 or later.)
  1953 
  1954 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1955 context.  Top-level ML bindings are stored within the proof context in
  1956 a purely sequential fashion, disregarding the nested proof structure.
  1957 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1958 proof.  (Requires Poly/ML 5.2 or later.)
  1959 
  1960 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1961 and Method.setup, as well as Isar commands 'attribute_setup' and
  1962 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1963 existing code accordingly, or use plain 'setup' together with old
  1964 Method.add_method.
  1965 
  1966 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1967 to 'a -> thm, while results are always tagged with an authentic oracle
  1968 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1969 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1970 accordingly.  Note that extra performance may be gained by producing
  1971 the cterm carefully, avoiding slow Thm.cterm_of.
  1972 
  1973 * Simplified interface for defining document antiquotations via
  1974 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1975 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1976 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1977 examples.
  1978 
  1979 * More systematic treatment of long names, abstract name bindings, and
  1980 name space operations.  Basic operations on qualified names have been
  1981 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1982 Long_Name.append.  Old type bstring has been mostly replaced by
  1983 abstract type binding (see structure Binding), which supports precise
  1984 qualification by packages and local theory targets, as well as proper
  1985 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1986 bstring values into Binding.name, or better pass through abstract
  1987 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1988 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1989 
  1990 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1991 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1992 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1993 
  1994 * Disposed old type and term read functions (Sign.read_def_typ,
  1995 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1996 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1997 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1998 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1999 resort for legacy applications.
  2000 
  2001 * Disposed old declarations, tactics, tactic combinators that refer to
  2002 the simpset or claset of an implicit theory (such as Addsimps,
  2003 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2004 embedded ML text, or local_simpset_of with a proper context passed as
  2005 explicit runtime argument.
  2006 
  2007 * Rules and tactics that read instantiations (read_instantiate,
  2008 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2009 context, which is required for parsing and type-checking.  Moreover,
  2010 the variables are specified as plain indexnames, not string encodings
  2011 thereof.  INCOMPATIBILITY.
  2012 
  2013 * Generic Toplevel.add_hook interface allows to analyze the result of
  2014 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2015 for theorem dependency output of transactions resulting in a new
  2016 theory state.
  2017 
  2018 * ML antiquotations: block-structured compilation context indicated by
  2019 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2020 
  2021   @{binding name}                         - basic name binding
  2022   @{let ?pat = term}                      - term abbreviation (HO matching)
  2023   @{note name = fact}                     - fact abbreviation
  2024   @{thm fact}                             - singleton fact (with attributes)
  2025   @{thms fact}                            - general fact (with attributes)
  2026   @{lemma prop by method}                 - singleton goal
  2027   @{lemma prop by meth1 meth2}            - singleton goal
  2028   @{lemma prop1 ... propN by method}      - general goal
  2029   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2030   @{lemma (open) ...}                     - open derivation
  2031 
  2032 
  2033 *** System ***
  2034 
  2035 * The Isabelle "emacs" tool provides a specific interface to invoke
  2036 Proof General / Emacs, with more explicit failure if that is not
  2037 installed (the old isabelle-interface script silently falls back on
  2038 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2039 installation location of the Proof General distribution.
  2040 
  2041 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2042 the Isabelle process into a JVM/Scala application.  See
  2043 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2044 process wrapper has been discontinued.)
  2045 
  2046 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2047 
  2048 * Various status messages (with exact source position information) are
  2049 emitted, if proper markup print mode is enabled.  This allows
  2050 user-interface components to provide detailed feedback on internal
  2051 prover operations.
  2052 
  2053 
  2054 
  2055 New in Isabelle2008 (June 2008)
  2056 -------------------------------
  2057 
  2058 *** General ***
  2059 
  2060 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2061 and updated, with formally checked references as hyperlinks.
  2062 
  2063 * Theory loader: use_thy (and similar operations) no longer set the
  2064 implicit ML context, which was occasionally hard to predict and in
  2065 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2066 provides a proper context already.
  2067 
  2068 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2069 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2070 'use' within a theory file will do the job.
  2071 
  2072 * Name space merge now observes canonical order, i.e. the second space
  2073 is inserted into the first one, while existing entries in the first
  2074 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2075 swap theory imports.
  2076 
  2077 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2078 INCOMPATIBILITY in identifier syntax etc.
  2079 
  2080 * Outer syntax: string tokens no longer admit escaped white space,
  2081 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2082 white space without escapes.
  2083 
  2084 * Outer syntax: string tokens may contain arbitrary character codes
  2085 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2086 "foo_bar".
  2087 
  2088 
  2089 *** Pure ***
  2090 
  2091 * Context-dependent token translations.  Default setup reverts locally
  2092 fixed variables, and adds hilite markup for undeclared frees.
  2093 
  2094 * Unused theorems can be found using the new command 'unused_thms'.
  2095 There are three ways of invoking it:
  2096 
  2097 (1) unused_thms
  2098      Only finds unused theorems in the current theory.
  2099 
  2100 (2) unused_thms thy_1 ... thy_n -
  2101      Finds unused theorems in the current theory and all of its ancestors,
  2102      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2103 
  2104 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2105      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2106      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2107      their ancestors.
  2108 
  2109 In order to increase the readability of the list produced by
  2110 unused_thms, theorems that have been created by a particular instance
  2111 of a theory command such as 'inductive' or 'function' are considered
  2112 to belong to the same "group", meaning that if at least one theorem in
  2113 this group is used, the other theorems in the same group are no longer
  2114 reported as unused.  Moreover, if all theorems in the group are
  2115 unused, only one theorem in the group is displayed.
  2116 
  2117 Note that proof objects have to be switched on in order for
  2118 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2119 usually the case when using Proof General with the default settings).
  2120 
  2121 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2122 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2123 duplicate fact bindings, or even accidental fact duplications.  Note
  2124 that tools may maintain dynamically scoped facts systematically, using
  2125 PureThy.add_thms_dynamic.
  2126 
  2127 * Command 'hide' now allows to hide from "fact" name space as well.
  2128 
  2129 * Eliminated destructive theorem database, simpset, claset, and
  2130 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2131 update of theories within ML code.
  2132 
  2133 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2134 INCOMPATIBILITY, object-logics depending on former Pure require
  2135 additional setup PureThy.old_appl_syntax_setup; object-logics
  2136 depending on former CPure need to refer to Pure.
  2137 
  2138 * Commands 'use' and 'ML' are now purely functional, operating on
  2139 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2140 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2141 INCOMPATIBILITY.
  2142 
  2143 * Command 'setup': discontinued implicit version with ML reference.
  2144 
  2145 * Instantiation target allows for simultaneous specification of class
  2146 instance operations together with an instantiation proof.
  2147 Type-checking phase allows to refer to class operations uniformly.
  2148 See src/HOL/Complex/Complex.thy for an Isar example and
  2149 src/HOL/Library/Eval.thy for an ML example.
  2150 
  2151 * Indexing of literal facts: be more serious about including only
  2152 facts from the visible specification/proof context, but not the
  2153 background context (locale etc.).  Affects `prop` notation and method
  2154 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2155 situations.
  2156 
  2157 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2158 "(open)" option, which used to expose internal bound variables to the
  2159 proof text.
  2160 
  2161 * Isar statements: removed obsolete case "rule_context".
  2162 INCOMPATIBILITY, better use explicit fixes/assumes.
  2163 
  2164 * Locale proofs: default proof step now includes 'unfold_locales';
  2165 hence 'proof' without argument may be used to unfold locale
  2166 predicates.
  2167 
  2168 
  2169 *** Document preparation ***
  2170 
  2171 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2172 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2173 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2174 spot); renamed link color from "darkblue" to "linkcolor" (default
  2175 value unchanged, can be redefined via \definecolor); no longer sets
  2176 "a4paper" option (unnecessary or even intrusive).
  2177 
  2178 * Antiquotation @{lemma A method} proves proposition A by the given
  2179 method (either a method name or a method name plus (optional) method
  2180 arguments in parentheses) and prints A just like @{prop A}.
  2181 
  2182 
  2183 *** HOL ***
  2184 
  2185 * New primrec package.  Specification syntax conforms in style to
  2186 definition/function/....  No separate induction rule is provided.  The
  2187 "primrec" command distinguishes old-style and new-style specifications
  2188 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2189 When adjusting theories, beware: constants stemming from new-style
  2190 primrec specifications have authentic syntax.
  2191 
  2192 * Metis prover is now an order of magnitude faster, and also works
  2193 with multithreading.
  2194 
  2195 * Metis: the maximum number of clauses that can be produced from a
  2196 theorem is now given by the attribute max_clauses.  Theorems that
  2197 exceed this number are ignored, with a warning printed.
  2198 
  2199 * Sledgehammer no longer produces structured proofs by default. To
  2200 enable, declare [[sledgehammer_full = true]].  Attributes
  2201 reconstruction_modulus, reconstruction_sorts renamed
  2202 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2203 
  2204 * Method "induct_scheme" derives user-specified induction rules
  2205 from well-founded induction and completeness of patterns. This factors
  2206 out some operations that are done internally by the function package
  2207 and makes them available separately.  See
  2208 src/HOL/ex/Induction_Scheme.thy for examples.
  2209 
  2210 * More flexible generation of measure functions for termination
  2211 proofs: Measure functions can be declared by proving a rule of the
  2212 form "is_measure f" and giving it the [measure_function] attribute.
  2213 The "is_measure" predicate is logically meaningless (always true), and
  2214 just guides the heuristic.  To find suitable measure functions, the
  2215 termination prover sets up the goal "is_measure ?f" of the appropriate
  2216 type and generates all solutions by prolog-style backwards proof using
  2217 the declared rules.
  2218 
  2219 This setup also deals with rules like 
  2220 
  2221   "is_measure f ==> is_measure (list_size f)"
  2222 
  2223 which accommodates nested datatypes that recurse through lists.
  2224 Similar rules are predeclared for products and option types.
  2225 
  2226 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2227 
  2228   INCOMPATIBILITIES:
  2229 
  2230   - Definitions of overloaded constants on sets have to be replaced by
  2231     definitions on => and bool.
  2232 
  2233   - Some definitions of overloaded operators on sets can now be proved
  2234     using the definitions of the operators on => and bool.  Therefore,
  2235     the following theorems have been renamed:
  2236 
  2237       subset_def   -> subset_eq
  2238       psubset_def  -> psubset_eq
  2239       set_diff_def -> set_diff_eq
  2240       Compl_def    -> Compl_eq
  2241       Sup_set_def  -> Sup_set_eq
  2242       Inf_set_def  -> Inf_set_eq
  2243       sup_set_def  -> sup_set_eq
  2244       inf_set_def  -> inf_set_eq
  2245 
  2246   - Due to the incompleteness of the HO unification algorithm, some
  2247     rules such as subst may require manual instantiation, if some of
  2248     the unknowns in the rule is a set.
  2249 
  2250   - Higher order unification and forward proofs:
  2251     The proof pattern
  2252 
  2253       have "P (S::'a set)" <...>
  2254       then have "EX S. P S" ..
  2255 
  2256     no longer works (due to the incompleteness of the HO unification
  2257     algorithm) and must be replaced by the pattern
  2258 
  2259       have "EX S. P S"
  2260       proof
  2261         show "P S" <...>
  2262       qed
  2263 
  2264   - Calculational reasoning with subst (or similar rules):
  2265     The proof pattern
  2266 
  2267       have "P (S::'a set)" <...>
  2268       also have "S = T" <...>
  2269       finally have "P T" .
  2270 
  2271     no longer works (for similar reasons as the previous example) and
  2272     must be replaced by something like
  2273 
  2274       have "P (S::'a set)" <...>
  2275       moreover have "S = T" <...>
  2276       ultimately have "P T" by simp
  2277 
  2278   - Tactics or packages written in ML code:
  2279     Code performing pattern matching on types via
  2280 
  2281       Type ("set", [T]) => ...
  2282 
  2283     must be rewritten. Moreover, functions like strip_type or
  2284     binder_types no longer return the right value when applied to a
  2285     type of the form
  2286 
  2287       T1 => ... => Tn => U => bool
  2288 
  2289     rather than
  2290 
  2291       T1 => ... => Tn => U set
  2292 
  2293 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2294 Wellfounded_Relations to theory Wellfounded.
  2295 
  2296 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2297 
  2298 * Class finite no longer treats UNIV as class parameter.  Use class
  2299 enum from theory Library/Enum instead to achieve a similar effect.
  2300 INCOMPATIBILITY.
  2301 
  2302 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2303 and "Cons".  INCOMPATIBILITY.
  2304 
  2305 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2306 Potential INCOMPATIBILITY.
  2307 
  2308 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2309 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2310 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2311 
  2312 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2313 the same name in theory Orderings:
  2314 
  2315   less_trans
  2316   less_linear
  2317   le_imp_less_or_eq
  2318   le_less_trans
  2319   less_le_trans
  2320   less_not_sym
  2321   less_asym
  2322 
  2323 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2324 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2325 and different variable names.
  2326 
  2327 * Library/Option_ord.thy: Canonical order on option type.
  2328 
  2329 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2330 finite maps.
  2331 
  2332 * Library/Countable.thy: Type class for countable types.
  2333 
  2334 * Theory Int: The representation of numerals has changed.  The infix
  2335 operator BIT and the bit datatype with constructors B0 and B1 have
  2336 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2337 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2338 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2339 accordingly.
  2340 
  2341 * Theory Nat: definition of <= and < on natural numbers no longer
  2342 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2343 le_def and less_def have disappeared.  Consider lemmas not_less
  2344 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2345 
  2346 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2347 (whose purpose mainly is for various fold_set functionals) have been
  2348 abandoned in favor of the existing algebraic classes
  2349 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2350 lower_semilattice (resp. upper_semilattice) and linorder.
  2351 INCOMPATIBILITY.
  2352 
  2353 * Theory Transitive_Closure: induct and cases rules now declare proper
  2354 case_names ("base" and "step").  INCOMPATIBILITY.
  2355 
  2356 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2357 lattices.  The form set-specific version is available as
  2358 Inductive.lfp_ordinal_induct_set.
  2359 
  2360 * Renamed theorems "power.simps" to "power_int.simps".
  2361 INCOMPATIBILITY.
  2362 
  2363 * Class semiring_div provides basic abstract properties of semirings
  2364 with division and modulo operations.  Subsumes former class dvd_mod.
  2365 
  2366 * Merged theories IntDef, Numeral and IntArith into unified theory
  2367 Int.  INCOMPATIBILITY.
  2368 
  2369 * Theory Library/Code_Index: type "index" now represents natural
  2370 numbers rather than integers.  INCOMPATIBILITY.
  2371 
  2372 * New class "uminus" with operation "uminus" (split of from class
  2373 "minus" which now only has operation "minus", binary).
  2374 INCOMPATIBILITY.
  2375 
  2376 * Constants "card", "internal_split", "option_map" now with authentic
  2377 syntax.  INCOMPATIBILITY.
  2378 
  2379 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2380 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2381 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2382 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2383 Sup_set_def, le_def, less_def, option_map_def now with object
  2384 equality.  INCOMPATIBILITY.
  2385 
  2386 * Records. Removed K_record, and replaced it by pure lambda term
  2387 %x. c. The simplifier setup is now more robust against eta expansion.
  2388 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2389 
  2390 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2391 
  2392 * Library/ListVector: new theory of arithmetic vector operations.
  2393 
  2394 * Library/Order_Relation: new theory of various orderings as sets of
  2395 pairs.  Defines preorders, partial orders, linear orders and
  2396 well-orders on sets and on types.
  2397 
  2398 
  2399 *** ZF ***
  2400 
  2401 * Renamed some theories to allow to loading both ZF and HOL in the
  2402 same session:
  2403 
  2404   Datatype  -> Datatype_ZF
  2405   Inductive -> Inductive_ZF
  2406   Int       -> Int_ZF
  2407   IntDiv    -> IntDiv_ZF
  2408   Nat       -> Nat_ZF
  2409   List      -> List_ZF
  2410   Main      -> Main_ZF
  2411 
  2412 INCOMPATIBILITY: ZF theories that import individual theories below
  2413 Main might need to be adapted.  Regular theory Main is still
  2414 available, as trivial extension of Main_ZF.
  2415 
  2416 
  2417 *** ML ***
  2418 
  2419 * ML within Isar: antiquotation @{const name} or @{const
  2420 name(typargs)} produces statically-checked Const term.
  2421 
  2422 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2423 (of the same name).  Removed obsolete print command.
  2424 
  2425 * Removed obsolete "use_legacy_bindings" function.
  2426 
  2427 * The ``print mode'' is now a thread-local value derived from a global
  2428 template (the former print_mode reference), thus access becomes
  2429 non-critical.  The global print_mode reference is for session
  2430 management only; user-code should use print_mode_value,
  2431 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2432 
  2433 * Functions system/system_out provide a robust way to invoke external
  2434 shell commands, with propagation of interrupts (requires Poly/ML
  2435 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2436 
  2437 
  2438 *** System ***
  2439 
  2440 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2441 in accordance with Proof General 3.7, which prefers GNU emacs.
  2442 
  2443 * isatool tty runs Isabelle process with plain tty interaction;
  2444 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2445 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2446 
  2447 * isatool browser now works with Cygwin as well, using general
  2448 "javapath" function defined in Isabelle process environment.
  2449 
  2450 * YXML notation provides a simple and efficient alternative to
  2451 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2452 isatool yxml as described in the Isabelle system manual.
  2453 
  2454 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2455 provides general wrapper for managing an Isabelle process in a robust
  2456 fashion, with ``cooked'' output from stdin/stderr.
  2457 
  2458 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2459 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2460 
  2461 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2462 way of changing the user's settings is via
  2463 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2464 script.
  2465 
  2466 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2467 cores of the underlying machine, which is a good starting point for
  2468 optimal performance tuning.  The corresponding usedir option -M allows
  2469 "max" as an alias for "0".  WARNING: does not work on certain versions
  2470 of Mac OS (with Poly/ML 5.1).
  2471 
  2472 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2473 adverse effect of Isabelle flooding interactive front-ends (notably
  2474 ProofGeneral / XEmacs).
  2475 
  2476 
  2477 
  2478 New in Isabelle2007 (November 2007)
  2479 -----------------------------------
  2480 
  2481 *** General ***
  2482 
  2483 * More uniform information about legacy features, notably a
  2484 warning/error of "Legacy feature: ...", depending on the state of the
  2485 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2486 legacy features will disappear eventually.
  2487 
  2488 * Theory syntax: the header format ``theory A = B + C:'' has been
  2489 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2490 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2491 
  2492 * Theory syntax: the old non-Isar theory file format has been
  2493 discontinued altogether.  Note that ML proof scripts may still be used
  2494 with Isar theories; migration is usually quite simple with the ML
  2495 function use_legacy_bindings.  INCOMPATIBILITY.
  2496 
  2497 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2498 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2499 quotes.
  2500 
  2501 * Theory loader: be more serious about observing the static theory
  2502 header specifications (including optional directories), but not the
  2503 accidental file locations of previously successful loads.  The strict
  2504 update policy of former update_thy is now already performed by
  2505 use_thy, so the former has been removed; use_thys updates several
  2506 theories simultaneously, just as 'imports' within a theory header
  2507 specification, but without merging the results.  Potential
  2508 INCOMPATIBILITY: may need to refine theory headers and commands
  2509 ROOT.ML which depend on load order.
  2510 
  2511 * Theory loader: optional support for content-based file
  2512 identification, instead of the traditional scheme of full physical
  2513 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2514 (cf. the system manual).  The new scheme allows to work with
  2515 non-finished theories in persistent session images, such that source
  2516 files may be moved later on without requiring reloads.
  2517 
  2518 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2519 file (with the same base name as the theory) are considered a legacy
  2520 feature, which will disappear eventually. Even now, the theory loader
  2521 no longer maintains dependencies on such files.
  2522 
  2523 * Syntax: the scope for resolving ambiguities via type-inference is
  2524 now limited to individual terms, instead of whole simultaneous
  2525 specifications as before. This greatly reduces the complexity of the
  2526 syntax module and improves flexibility by separating parsing and
  2527 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2528 'fixes' etc.) are required in rare situations.
  2529 
  2530 * Syntax: constants introduced by new-style packages ('definition',
  2531 'abbreviation' etc.) are passed through the syntax module in
  2532 ``authentic mode''. This means that associated mixfix annotations
  2533 really stick to such constants, independently of potential name space
  2534 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2535 trees are represented slightly differently, may need to adapt syntax
  2536 translations accordingly. Use CONST marker in 'translations' and
  2537 @{const_syntax} antiquotation in 'parse_translation' etc.
  2538 
  2539 * Legacy goal package: reduced interface to the bare minimum required
  2540 to keep existing proof scripts running.  Most other user-level
  2541 functions are now part of the OldGoals structure, which is *not* open
  2542 by default (consider isatool expandshort before open OldGoals).
  2543 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2544 these tend to cause confusion about the actual goal (!) context being
  2545 used here, which is not necessarily the same as the_context().
  2546 
  2547 * Command 'find_theorems': supports "*" wild-card in "name:"
  2548 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2549 support a specific search form (see ProofGeneral/CHANGES).
  2550 
  2551 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2552 by default, which means that "prems" (and also "fixed variables") are
  2553 suppressed from proof state output.  Note that the ProofGeneral
  2554 settings mechanism allows to change and save options persistently, but
  2555 older versions of Isabelle will fail to start up if a negative prems
  2556 limit is imposed.
  2557 
  2558 * Local theory targets may be specified by non-nested blocks of
  2559 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2560 contain definitions, theorems etc., including any derived mechanism
  2561 that has been implemented on top of these primitives.  This concept
  2562 generalizes the existing ``theorem (in ...)'' towards more versatility
  2563 and scalability.
  2564 
  2565 * Proof General interface: proper undo of final 'end' command;
  2566 discontinued Isabelle/classic mode (ML proof scripts).
  2567 
  2568 
  2569 *** Document preparation ***
  2570 
  2571 * Added antiquotation @{theory name} which prints the given name,
  2572 after checking that it refers to a valid ancestor theory in the
  2573 current context.
  2574 
  2575 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2576 check the given source text as ML type/structure, printing verbatim.
  2577 
  2578 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2579 "c args == rhs" given in the current context.  (Any number of
  2580 arguments may be given on the LHS.)
  2581 
  2582 
  2583 *** Pure ***
  2584 
  2585 * The 'class' package offers a combination of axclass and locale to
  2586 achieve Haskell-like type classes in Isabelle.  Definitions and
  2587 theorems within a class context produce both relative results (with
  2588 implicit parameters according to the locale context), and polymorphic
  2589 constants with qualified polymorphism (according to the class
  2590 context).  Within the body context of a 'class' target, a separate
  2591 syntax layer ("user space type system") takes care of converting
  2592 between global polymorphic consts and internal locale representation.
  2593 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2594 "isatool doc classes" provides a tutorial.
  2595 
  2596 * Generic code generator framework allows to generate executable
  2597 code for ML and Haskell (including Isabelle classes).  A short usage
  2598 sketch:
  2599 
  2600     internal compilation:
  2601         export_code <list of constants (term syntax)> in SML
  2602     writing SML code to a file:
  2603         export_code <list of constants (term syntax)> in SML <filename>
  2604     writing OCaml code to a file:
  2605         export_code <list of constants (term syntax)> in OCaml <filename>
  2606     writing Haskell code to a bunch of files:
  2607         export_code <list of constants (term syntax)> in Haskell <filename>
  2608 
  2609     evaluating closed propositions to True/False using code generation:
  2610         method ``eval''
  2611 
  2612 Reasonable default setup of framework in HOL.
  2613 
  2614 Theorem attributs for selecting and transforming function equations theorems:
  2615 
  2616     [code fun]:        select a theorem as function equation for a specific constant
  2617     [code fun del]:    deselect a theorem as function equation for a specific constant
  2618     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2619     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2620 
  2621 User-defined serializations (target in {SML, OCaml, Haskell}):
  2622 
  2623     code_const <and-list of constants (term syntax)>
  2624       {(target) <and-list of const target syntax>}+
  2625 
  2626     code_type <and-list of type constructors>
  2627       {(target) <and-list of type target syntax>}+
  2628 
  2629     code_instance <and-list of instances>
  2630       {(target)}+
  2631         where instance ::= <type constructor> :: <class>
  2632 
  2633     code_class <and_list of classes>
  2634       {(target) <and-list of class target syntax>}+
  2635         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2636 
  2637 code_instance and code_class only are effective to target Haskell.
  2638 
  2639 For example usage see src/HOL/ex/Codegenerator.thy and
  2640 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2641 generation from Isabelle/HOL theories is available via "isatool doc
  2642 codegen".
  2643 
  2644 * Code generator: consts in 'consts_code' Isar commands are now
  2645 referred to by usual term syntax (including optional type
  2646 annotations).
  2647 
  2648 * Command 'no_translations' removes translation rules from theory
  2649 syntax.
  2650 
  2651 * Overloaded definitions are now actually checked for acyclic
  2652 dependencies.  The overloading scheme is slightly more general than
  2653 that of Haskell98, although Isabelle does not demand an exact
  2654 correspondence to type class and instance declarations.
  2655 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2656 exotic versions of overloading -- at the discretion of the user!
  2657 
  2658 Polymorphic constants are represented via type arguments, i.e. the
  2659 instantiation that matches an instance against the most general
  2660 declaration given in the signature.  For example, with the declaration
  2661 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2662 as c(nat).  Overloading is essentially simultaneous structural
  2663 recursion over such type arguments.  Incomplete specification patterns
  2664 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2665 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2666 Command 'print_theory' outputs the normalized system of recursive
  2667 equations, see section "definitions".
  2668 
  2669 * Configuration options are maintained within the theory or proof
  2670 context (with name and type bool/int/string), providing a very simple
  2671 interface to a poor-man's version of general context data.  Tools may
  2672 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2673 these values using Config.get etc.  Users may change options via an
  2674 associated attribute of the same name.  This form of context
  2675 declaration works particularly well with commands 'declare' or
  2676 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2677 very easy to avoid global references, which would not observe Isar
  2678 toplevel undo/redo and fail to work with multithreading.
  2679 
  2680 Various global ML references of Pure and HOL have been turned into
  2681 configuration options:
  2682 
  2683   Unify.search_bound		unify_search_bound
  2684   Unify.trace_bound		unify_trace_bound
  2685   Unify.trace_simp		unify_trace_simp
  2686   Unify.trace_types		unify_trace_types
  2687   Simplifier.simp_depth_limit	simp_depth_limit
  2688   Blast.depth_limit		blast_depth_limit
  2689   DatatypeProp.dtK		datatype_distinctness_limit
  2690   fast_arith_neq_limit  	fast_arith_neq_limit
  2691   fast_arith_split_limit	fast_arith_split_limit
  2692 
  2693 * Named collections of theorems may be easily installed as context
  2694 data using the functor NamedThmsFun (see also
  2695 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2696 attributes; there is also a toplevel print command.  This facility is
  2697 just a common case of general context data, which is the preferred way
  2698 for anything more complex than just a list of facts in canonical
  2699 order.
  2700 
  2701 * Isar: command 'declaration' augments a local theory by generic
  2702 declaration functions written in ML.  This enables arbitrary content
  2703 being added to the context, depending on a morphism that tells the
  2704 difference of the original declaration context wrt. the application
  2705 context encountered later on.
  2706 
  2707 * Isar: proper interfaces for simplification procedures.  Command
  2708 'simproc_setup' declares named simprocs (with match patterns, and body
  2709 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2710 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2711 
  2712 * Isar: an extra pair of brackets around attribute declarations
  2713 abbreviates a theorem reference involving an internal dummy fact,
  2714 which will be ignored later --- only the effect of the attribute on
  2715 the background context will persist.  This form of in-place
  2716 declarations is particularly useful with commands like 'declare' and
  2717 'using', for example ``have A using [[simproc a]] by simp''.
  2718 
  2719 * Isar: method "assumption" (and implicit closing of subproofs) now
  2720 takes simple non-atomic goal assumptions into account: after applying
  2721 an assumption as a rule the resulting subgoals are solved by atomic
  2722 assumption steps.  This is particularly useful to finish 'obtain'
  2723 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2724 without referring to the original premise "!!x. P x ==> thesis" in the
  2725 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2726 more permissive.
  2727 
  2728 * Isar: implicit use of prems from the Isar proof context is
  2729 considered a legacy feature.  Common applications like ``have A .''
  2730 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2731 referencing facts explicitly here improves readability and
  2732 maintainability of proof texts.
  2733 
  2734 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2735 the obtained context from the course of reasoning!  For example:
  2736 
  2737   assume "EX x y. A x & B y"   -- "any previous fact"
  2738   then guess x and y by clarify
  2739 
  2740 This technique is potentially adventurous, depending on the facts and
  2741 proof tools being involved here.
  2742 
  2743 * Isar: known facts from the proof context may be specified as literal
  2744 propositions, using ASCII back-quote syntax.  This works wherever
  2745 named facts used to be allowed so far, in proof commands, proof
  2746 methods, attributes etc.  Literal facts are retrieved from the context
  2747 according to unification of type and term parameters.  For example,
  2748 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2749 theorems in the current context, then these are valid literal facts:
  2750 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2751 
  2752 There is also a proof method "fact" which does the same composition
  2753 for explicit goal states, e.g. the following proof texts coincide with
  2754 certain special cases of literal facts:
  2755 
  2756   have "A" by fact                 ==  note `A`
  2757   have "A ==> B" by fact           ==  note `A ==> B`
  2758   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2759   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2760 
  2761 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2762 outer syntax.  Thus symbolic identifiers may be used without
  2763 additional white space in declarations like this: ``assume *: A''.
  2764 
  2765 * Isar: 'print_facts' prints all local facts of the current context,
  2766 both named and unnamed ones.
  2767 
  2768 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2769 
  2770   def x == "t" and y == "u"
  2771 
  2772 * Isar: added command 'unfolding', which is structurally similar to
  2773 'using', but affects both the goal state and facts by unfolding given
  2774 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2775 'unfolded' attribute may be replaced by first-class proof text.
  2776 
  2777 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2778 and command 'unfolding' now all support object-level equalities
  2779 (potentially conditional).  The underlying notion of rewrite rule is
  2780 analogous to the 'rule_format' attribute, but *not* that of the
  2781 Simplifier (which is usually more generous).
  2782 
  2783 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2784 premises of a theorem by n. Useful in conjunction with drule.
  2785 
  2786 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2787 method expression within a sandbox consisting of the first N
  2788 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2789 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2790 simplifies all new goals that emerge from applying rule foo to the
  2791 originally first one.
  2792 
  2793 * Isar: schematic goals are no longer restricted to higher-order
  2794 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2795 expected.
  2796 
  2797 * Isar: the conclusion of a long theorem statement is now either
  2798 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2799 (essentially a disjunction of cases with local parameters and
  2800 assumptions).  The latter allows to express general elimination rules
  2801 adequately; in this notation common elimination rules look like this:
  2802 
  2803   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2804     assumes "EX x. P x"
  2805     obtains x where "P x"
  2806 
  2807   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2808     assumes "A & B"
  2809     obtains A and B
  2810 
  2811   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2812     assumes "A | B"
  2813     obtains
  2814       A
  2815     | B
  2816 
  2817 The subsequent classical rules even refer to the formal "thesis"
  2818 explicitly:
  2819 
  2820   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2821     obtains "~ thesis"
  2822 
  2823   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2824     obtains "thesis ==> something"
  2825 
  2826 The actual proof of an 'obtains' statement is analogous to that of the
  2827 Isar proof element 'obtain', only that there may be several cases.
  2828 Optional case names may be specified in parentheses; these will be
  2829 available both in the present proof and as annotations in the
  2830 resulting rule, for later use with the 'cases' method (cf. attribute
  2831 case_names).
  2832 
  2833 * Isar: the assumptions of a long theorem statement are available as
  2834 "assms" fact in the proof context.  This is more appropriate than the
  2835 (historical) "prems", which refers to all assumptions of the current
  2836 context, including those from the target locale, proof body etc.
  2837 
  2838 * Isar: 'print_statement' prints theorems from the current theory or
  2839 proof context in long statement form, according to the syntax of a
  2840 top-level lemma.
  2841 
  2842 * Isar: 'obtain' takes an optional case name for the local context
  2843 introduction rule (default "that").
  2844 
  2845 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2846 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2847 to occur.
  2848 
  2849 * Pure: syntax "CONST name" produces a fully internalized constant
  2850 according to the current context.  This is particularly useful for
  2851 syntax translations that should refer to internal constant
  2852 representations independently of name spaces.
  2853 
  2854 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2855 instead of "FOO ". This allows multiple binder declarations to coexist
  2856 in the same context.  INCOMPATIBILITY.
  2857 
  2858 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2859 primitive that also works in a locale context (both for constants and
  2860 fixed variables). Type declaration and internal syntactic representation
  2861 of given constants retrieved from the context. Likewise, the
  2862 'no_notation' command allows to remove given syntax annotations from the
  2863 current context.
  2864 
  2865 * Isar/locales: new derived specification elements 'axiomatization',
  2866 'definition', 'abbreviation', which support type-inference, admit
  2867 object-level specifications (equality, equivalence).  See also the
  2868 isar-ref manual.  Examples:
  2869 
  2870   axiomatization
  2871     eq  (infix "===" 50) where
  2872     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2873 
  2874   definition "f x y = x + y + 1"
  2875   definition g where "g x = f x x"
  2876 
  2877   abbreviation
  2878     neq  (infix "=!=" 50) where
  2879     "x =!= y == ~ (x === y)"
  2880 
  2881 These specifications may be also used in a locale context.  Then the
  2882 constants being introduced depend on certain fixed parameters, and the
  2883 constant name is qualified by the locale base name.  An internal
  2884 abbreviation takes care for convenient input and output, making the
  2885 parameters implicit and using the original short name.  See also
  2886 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2887 entities from a monomorphic theory.
  2888 
  2889 Presently, abbreviations are only available 'in' a target locale, but
  2890 not inherited by general import expressions.  Also note that
  2891 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2892 'translations' in common applications.  The "no_abbrevs" print mode
  2893 prevents folding of abbreviations in term output.
  2894 
  2895 Concrete syntax is attached to specified constants in internal form,
  2896 independently of name spaces.  The parse tree representation is
  2897 slightly different -- use 'notation' instead of raw 'syntax', and
  2898 'translations' with explicit "CONST" markup to accommodate this.
  2899 
  2900 * Pure/Isar: unified syntax for new-style specification mechanisms
  2901 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2902 full type inference and dummy patterns ("_").  For example:
  2903 
  2904   definition "K x _ = x"
  2905 
  2906   inductive conj for A B
  2907   where "A ==> B ==> conj A B"
  2908 
  2909 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2910 the current context.  Print mode "no_abbrevs" prevents inversion of
  2911 abbreviations on output.
  2912 
  2913 * Isar/locales: improved parameter handling: use of locales "var" and
  2914 "struct" no longer necessary; - parameter renamings are no longer
  2915 required to be injective.  For example, this allows to define
  2916 endomorphisms as locale endom = homom mult mult h.
  2917 
  2918 * Isar/locales: changed the way locales with predicates are defined.
  2919 Instead of accumulating the specification, the imported expression is
  2920 now an interpretation.  INCOMPATIBILITY: different normal form of
  2921 locale expressions.  In particular, in interpretations of locales with
  2922 predicates, goals repesenting already interpreted fragments are not
  2923 removed automatically.  Use methods `intro_locales' and
  2924 `unfold_locales'; see below.
  2925 
  2926 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2927 provide backward reasoning on locales predicates.  The methods are
  2928 aware of interpretations and discharge corresponding goals.
  2929 `intro_locales' is less aggressive then `unfold_locales' and does not
  2930 unfold predicates to assumptions.
  2931 
  2932 * Isar/locales: the order in which locale fragments are accumulated
  2933 has changed.  This enables to override declarations from fragments due
  2934 to interpretations -- for example, unwanted simp rules.
  2935 
  2936 * Isar/locales: interpretation in theories and proof contexts has been
  2937 extended.  One may now specify (and prove) equations, which are
  2938 unfolded in interpreted theorems.  This is useful for replacing
  2939 defined concepts (constants depending on locale parameters) by
  2940 concepts already existing in the target context.  Example:
  2941 
  2942   interpretation partial_order ["op <= :: [int, int] => bool"]
  2943     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2944 
  2945 Typically, the constant `partial_order.less' is created by a
  2946 definition specification element in the context of locale
  2947 partial_order.
  2948 
  2949 * Method "induct": improved internal context management to support
  2950 local fixes and defines on-the-fly. Thus explicit meta-level
  2951 connectives !!  and ==> are rarely required anymore in inductive goals
  2952 (using object-logic connectives for this purpose has been long
  2953 obsolete anyway). Common proof patterns are explained in
  2954 src/HOL/Induct/Common_Patterns.thy, see also
  2955 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2956 examples.
  2957 
  2958 * Method "induct": improved handling of simultaneous goals. Instead of
  2959 introducing object-level conjunction, the statement is now split into
  2960 several conclusions, while the corresponding symbolic cases are nested
  2961 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2962 see src/HOL/Induct/Common_Patterns.thy, for example.
  2963 
  2964 * Method "induct": mutual induction rules are now specified as a list
  2965 of rule sharing the same induction cases. HOL packages usually provide
  2966 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2967 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2968 mutual induction rules differently, i.e. like this:
  2969 
  2970   (induct rule: foo_bar.inducts)
  2971   (induct set: foo bar)
  2972   (induct pred: foo bar)
  2973   (induct type: foo bar)
  2974 
  2975 The ML function ProjectRule.projections turns old-style rules into the
  2976 new format.
  2977 
  2978 * Method "coinduct": dual of induction, see
  2979 src/HOL/Library/Coinductive_List.thy for various examples.
  2980 
  2981 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2982 considered a legacy feature.
  2983 
  2984 * Attribute "symmetric" produces result with standardized schematic
  2985 variables (index 0).  Potential INCOMPATIBILITY.
  2986 
  2987 * Simplifier: by default the simplifier trace only shows top level
  2988 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2989 default. Thus there is less danger of being flooded by the trace. The
  2990 trace indicates where parts have been suppressed.
  2991   
  2992 * Provers/classical: removed obsolete classical version of elim_format
  2993 attribute; classical elim/dest rules are now treated uniformly when
  2994 manipulating the claset.
  2995 
  2996 * Provers/classical: stricter checks to ensure that supplied intro,
  2997 dest and elim rules are well-formed; dest and elim rules must have at
  2998 least one premise.
  2999 
  3000 * Provers/classical: attributes dest/elim/intro take an optional
  3001 weight argument for the rule (just as the Pure versions).  Weights are
  3002 ignored by automated tools, but determine the search order of single
  3003 rule steps.
  3004 
  3005 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3006 where the body does not mention the bound variable.  Note that dummy
  3007 patterns implicitly depend on their context of bounds, which makes
  3008 "{_. _}" match any set comprehension as expected.  Potential
  3009 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3010 constant "_idtdummy" in the binding position.
  3011 
  3012 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3013 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3014 for example "A -> B" => "Pi A (%_. B)".
  3015 
  3016 * Pure: 'class_deps' command visualizes the subclass relation, using
  3017 the graph browser tool.
  3018 
  3019 * Pure: 'print_theory' now suppresses certain internal declarations by
  3020 default; use '!' option for full details.
  3021 
  3022 
  3023 *** HOL ***
  3024 
  3025 * Method "metis" proves goals by applying the Metis general-purpose
  3026 resolution prover (see also http://gilith.com/software/metis/).
  3027 Examples are in the directory MetisExamples.  WARNING: the
  3028 Isabelle/HOL-Metis integration does not yet work properly with
  3029 multi-threading.
  3030   
  3031 * Command 'sledgehammer' invokes external automatic theorem provers as
  3032 background processes.  It generates calls to the "metis" method if
  3033 successful. These can be pasted into the proof.  Users do not have to
  3034 wait for the automatic provers to return.  WARNING: does not really
  3035 work with multi-threading.
  3036 
  3037 * New "auto_quickcheck" feature tests outermost goal statements for
  3038 potential counter-examples.  Controlled by ML references
  3039 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3040 5000 milliseconds).  Fails silently if statements is outside of
  3041 executable fragment, or any other codgenerator problem occurs.
  3042 
  3043 * New constant "undefined" with axiom "undefined x = undefined".
  3044 
  3045 * Added class "HOL.eq", allowing for code generation with polymorphic
  3046 equality.
  3047 
  3048 * Some renaming of class constants due to canonical name prefixing in
  3049 the new 'class' package:
  3050 
  3051     HOL.abs ~> HOL.abs_class.abs
  3052     HOL.divide ~> HOL.divide_class.divide
  3053     0 ~> HOL.zero_class.zero
  3054     1 ~> HOL.one_class.one
  3055     op + ~> HOL.plus_class.plus
  3056     op - ~> HOL.minus_class.minus
  3057     uminus ~> HOL.minus_class.uminus
  3058     op * ~> HOL.times_class.times
  3059     op < ~> HOL.ord_class.less
  3060     op <= > HOL.ord_class.less_eq
  3061     Nat.power ~> Power.power_class.power
  3062     Nat.size ~> Nat.size_class.size
  3063     Numeral.number_of ~> Numeral.number_class.number_of
  3064     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3065     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3066     Orderings.min ~> Orderings.ord_class.min
  3067     Orderings.max ~> Orderings.ord_class.max
  3068     Divides.op div ~> Divides.div_class.div
  3069     Divides.op mod ~> Divides.div_class.mod
  3070     Divides.op dvd ~> Divides.div_class.dvd
  3071 
  3072 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3073 
  3074 a) User-defined constants using any of the names "plus", "minus",
  3075 "times", "less" or "less_eq". The standard syntax translations for
  3076 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3077 names.
  3078 
  3079 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3080 INCOMPATIBILITY: use more specific names.
  3081 
  3082 c) Permutative equations (e.g. "a + b = b + a")
  3083 Since the change of names also changes the order of terms, permutative
  3084 rewrite rules may get applied in a different order. Experience shows
  3085 that this is rarely the case (only two adaptions in the whole Isabelle
  3086 distribution).  INCOMPATIBILITY: rewrite proofs
  3087 
  3088 d) ML code directly refering to constant names
  3089 This in general only affects hand-written proof tactics, simprocs and
  3090 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3091 Consider using @{const_name} antiquotation.
  3092 
  3093 * New class "default" with associated constant "default".
  3094 
  3095 * Function "sgn" is now overloaded and available on int, real, complex
  3096 (and other numeric types), using class "sgn".  Two possible defs of
  3097 sgn are given as equational assumptions in the classes sgn_if and
  3098 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3099 INCOMPATIBILITY.
  3100 
  3101 * Locale "partial_order" now unified with class "order" (cf. theory
  3102 Orderings), added parameter "less".  INCOMPATIBILITY.
  3103 
  3104 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3105 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3106 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3107 
  3108 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3109 changed order of proof goals in instance proofs.
  3110 
  3111 * The transitivity reasoner for partial and linear orders is set up
  3112 for classes "order" and "linorder".  Instances of the reasoner are available
  3113 in all contexts importing or interpreting the corresponding locales.
  3114 Method "order" invokes the reasoner separately; the reasoner
  3115 is also integrated with the Simplifier as a solver.  Diagnostic
  3116 command 'print_orders' shows the available instances of the reasoner
  3117 in the current context.
  3118 
  3119 * Localized monotonicity predicate in theory "Orderings"; integrated
  3120 lemmas max_of_mono and min_of_mono with this predicate.
  3121 INCOMPATIBILITY.
  3122 
  3123 * Formulation of theorem "dense" changed slightly due to integration
  3124 with new class dense_linear_order.
  3125 
  3126 * Uniform lattice theory development in HOL.
  3127 
  3128     constants "meet" and "join" now named "inf" and "sup"
  3129     constant "Meet" now named "Inf"
  3130 
  3131     classes "meet_semilorder" and "join_semilorder" now named
  3132       "lower_semilattice" and "upper_semilattice"
  3133     class "lorder" now named "lattice"
  3134     class "comp_lat" now named "complete_lattice"
  3135 
  3136     Instantiation of lattice classes allows explicit definitions
  3137     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3138 
  3139   INCOMPATIBILITY.  Theorem renames:
  3140 
  3141     meet_left_le            ~> inf_le1
  3142     meet_right_le           ~> inf_le2
  3143     join_left_le            ~> sup_ge1
  3144     join_right_le           ~> sup_ge2
  3145     meet_join_le            ~> inf_sup_ord
  3146     le_meetI                ~> le_infI
  3147     join_leI                ~> le_supI
  3148     le_meet                 ~> le_inf_iff
  3149     le_join                 ~> ge_sup_conv
  3150     meet_idempotent         ~> inf_idem
  3151     join_idempotent         ~> sup_idem
  3152     meet_comm               ~> inf_commute
  3153     join_comm               ~> sup_commute
  3154     meet_leI1               ~> le_infI1
  3155     meet_leI2               ~> le_infI2
  3156     le_joinI1               ~> le_supI1
  3157     le_joinI2               ~> le_supI2
  3158     meet_assoc              ~> inf_assoc
  3159     join_assoc              ~> sup_assoc
  3160     meet_left_comm          ~> inf_left_commute
  3161     meet_left_idempotent    ~> inf_left_idem
  3162     join_left_comm          ~> sup_left_commute
  3163     join_left_idempotent    ~> sup_left_idem
  3164     meet_aci                ~> inf_aci
  3165     join_aci                ~> sup_aci
  3166     le_def_meet             ~> le_iff_inf
  3167     le_def_join             ~> le_iff_sup
  3168     join_absorp2            ~> sup_absorb2
  3169     join_absorp1            ~> sup_absorb1
  3170     meet_absorp1            ~> inf_absorb1
  3171     meet_absorp2            ~> inf_absorb2
  3172     meet_join_absorp        ~> inf_sup_absorb
  3173     join_meet_absorp        ~> sup_inf_absorb
  3174     distrib_join_le         ~> distrib_sup_le
  3175     distrib_meet_le         ~> distrib_inf_le
  3176 
  3177     add_meet_distrib_left   ~> add_inf_distrib_left
  3178     add_join_distrib_left   ~> add_sup_distrib_left
  3179     is_join_neg_meet        ~> is_join_neg_inf
  3180     is_meet_neg_join        ~> is_meet_neg_sup
  3181     add_meet_distrib_right  ~> add_inf_distrib_right
  3182     add_join_distrib_right  ~> add_sup_distrib_right
  3183     add_meet_join_distribs  ~> add_sup_inf_distribs
  3184     join_eq_neg_meet        ~> sup_eq_neg_inf
  3185     meet_eq_neg_join        ~> inf_eq_neg_sup
  3186     add_eq_meet_join        ~> add_eq_inf_sup
  3187     meet_0_imp_0            ~> inf_0_imp_0
  3188     join_0_imp_0            ~> sup_0_imp_0
  3189     meet_0_eq_0             ~> inf_0_eq_0
  3190     join_0_eq_0             ~> sup_0_eq_0
  3191     neg_meet_eq_join        ~> neg_inf_eq_sup
  3192     neg_join_eq_meet        ~> neg_sup_eq_inf
  3193     join_eq_if              ~> sup_eq_if
  3194 
  3195     mono_meet               ~> mono_inf
  3196     mono_join               ~> mono_sup
  3197     meet_bool_eq            ~> inf_bool_eq
  3198     join_bool_eq            ~> sup_bool_eq
  3199     meet_fun_eq             ~> inf_fun_eq
  3200     join_fun_eq             ~> sup_fun_eq
  3201     meet_set_eq             ~> inf_set_eq
  3202     join_set_eq             ~> sup_set_eq
  3203     meet1_iff               ~> inf1_iff
  3204     meet2_iff               ~> inf2_iff
  3205     meet1I                  ~> inf1I
  3206     meet2I                  ~> inf2I
  3207     meet1D1                 ~> inf1D1
  3208     meet2D1                 ~> inf2D1
  3209     meet1D2                 ~> inf1D2
  3210     meet2D2                 ~> inf2D2
  3211     meet1E                  ~> inf1E
  3212     meet2E                  ~> inf2E
  3213     join1_iff               ~> sup1_iff
  3214     join2_iff               ~> sup2_iff
  3215     join1I1                 ~> sup1I1
  3216     join2I1                 ~> sup2I1
  3217     join1I1                 ~> sup1I1
  3218     join2I2                 ~> sup1I2
  3219     join1CI                 ~> sup1CI
  3220     join2CI                 ~> sup2CI
  3221     join1E                  ~> sup1E
  3222     join2E                  ~> sup2E
  3223 
  3224     is_meet_Meet            ~> is_meet_Inf
  3225     Meet_bool_def           ~> Inf_bool_def
  3226     Meet_fun_def            ~> Inf_fun_def
  3227     Meet_greatest           ~> Inf_greatest
  3228     Meet_lower              ~> Inf_lower
  3229     Meet_set_def            ~> Inf_set_def
  3230 
  3231     Sup_def                 ~> Sup_Inf
  3232     Sup_bool_eq             ~> Sup_bool_def
  3233     Sup_fun_eq              ~> Sup_fun_def
  3234     Sup_set_eq              ~> Sup_set_def
  3235 
  3236     listsp_meetI            ~> listsp_infI
  3237     listsp_meet_eq          ~> listsp_inf_eq
  3238 
  3239     meet_min                ~> inf_min
  3240     join_max                ~> sup_max
  3241 
  3242 * Added syntactic class "size"; overloaded constant "size" now has
  3243 type "'a::size ==> bool"
  3244 
  3245 * Internal reorganisation of `size' of datatypes: size theorems
  3246 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3247 simplification rules by default!); theorems "prod.size" now named
  3248 "*.size".
  3249 
  3250 * Class "div" now inherits from class "times" rather than "type".
  3251 INCOMPATIBILITY.
  3252 
  3253 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3254 Linorder etc.  have disappeared; operations defined in terms of
  3255 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3256 
  3257 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3258 
  3259 * HOL-Word: New extensive library and type for generic, fixed size
  3260 machine words, with arithemtic, bit-wise, shifting and rotating
  3261 operations, reflection into int, nat, and bool lists, automation for
  3262 linear arithmetic (by automatic reflection into nat or int), including
  3263 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3264 arithmetic type classes, supporting automatic simplification of
  3265 numerals on all operations.
  3266 
  3267 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3268 
  3269 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3270 
  3271 * Code generator library theories:
  3272   - Code_Integer represents HOL integers by big integer literals in target
  3273     languages.
  3274   - Code_Char represents HOL characters by character literals in target
  3275     languages.
  3276   - Code_Char_chr like Code_Char, but also offers treatment of character
  3277     codes; includes Code_Integer.
  3278   - Executable_Set allows to generate code for finite sets using lists.
  3279   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3280     denominator).
  3281   - Executable_Real implements a subset of real numbers, namly those
  3282     representable by rational numbers.
  3283   - Efficient_Nat implements natural numbers by integers, which in general will
  3284     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3285     includes Code_Integer.
  3286   - Code_Index provides an additional datatype index which is mapped to
  3287     target-language built-in integers.
  3288   - Code_Message provides an additional datatype message_string which is isomorphic to
  3289     strings; messages are mapped to target-language strings.
  3290 
  3291 * New package for inductive predicates
  3292 
  3293   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3294 
  3295     inductive
  3296       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3297       for z_1 :: U_1 and ... and z_n :: U_m
  3298     where
  3299       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3300     | ...
  3301 
  3302   with full support for type-inference, rather than
  3303 
  3304     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3305 
  3306     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3307     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3308 
  3309     inductive "s z_1 ... z_m"
  3310     intros
  3311       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3312       ...
  3313 
  3314   For backward compatibility, there is a wrapper allowing inductive
  3315   sets to be defined with the new package via
  3316 
  3317     inductive_set
  3318       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3319       for z_1 :: U_1 and ... and z_n :: U_m
  3320     where
  3321       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3322     | ...
  3323 
  3324   or
  3325 
  3326     inductive_set
  3327       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3328       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3329       for z_1 :: U_1 and ... and z_n :: U_m
  3330     where
  3331       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3332     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3333     | ...
  3334 
  3335   if the additional syntax "p ..." is required.
  3336 
  3337   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3338   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3339 
  3340   INCOMPATIBILITIES:
  3341 
  3342   - Since declaration and definition of inductive sets or predicates
  3343     is no longer separated, abbreviations involving the newly
  3344     introduced sets or predicates must be specified together with the
  3345     introduction rules after the 'where' keyword (see above), rather
  3346     than before the actual inductive definition.
  3347 
  3348   - The variables in induction and elimination rules are now
  3349     quantified in the order of their occurrence in the introduction
  3350     rules, rather than in alphabetical order. Since this may break
  3351     some proofs, these proofs either have to be repaired, e.g. by
  3352     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3353     statements of the form
  3354 
  3355       case (rule_i a_i_1 ... a_i_{k_i})
  3356 
  3357     or the old order of quantification has to be restored by explicitly adding
  3358     meta-level quantifiers in the introduction rules, i.e.
  3359 
  3360       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3361 
  3362   - The format of the elimination rules is now
  3363 
  3364       p z_1 ... z_m x_1 ... x_n ==>
  3365         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3366         ==> ... ==> P
  3367 
  3368     for predicates and
  3369 
  3370       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3371         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3372         ==> ... ==> P
  3373 
  3374     for sets rather than
  3375 
  3376       x : s z_1 ... z_m ==>
  3377         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3378         ==> ... ==> P
  3379 
  3380     This may require terms in goals to be expanded to n-tuples
  3381     (e.g. using case_tac or simplification with the split_paired_all
  3382     rule) before the above elimination rule is applicable.
  3383 
  3384   - The elimination or case analysis rules for (mutually) inductive
  3385     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3386     list of rules "p_1_..._p_k.elims" is no longer available.
  3387 
  3388 * New package "function"/"fun" for general recursive functions,
  3389 supporting mutual and nested recursion, definitions in local contexts,
  3390 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3391 for small examples, and the separate tutorial on the function
  3392 package. The old recdef "package" is still available as before, but
  3393 users are encouraged to use the new package.
  3394 
  3395 * Method "lexicographic_order" automatically synthesizes termination
  3396 relations as lexicographic combinations of size measures. 
  3397 
  3398 * Case-expressions allow arbitrary constructor-patterns (including
  3399 "_") and take their order into account, like in functional
  3400 programming.  Internally, this is translated into nested
  3401 case-expressions; missing cases are added and mapped to the predefined
  3402 constant "undefined". In complicated cases printing may no longer show
  3403 the original input but the internal form. Lambda-abstractions allow
  3404 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3405 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3406 variable.
  3407 
  3408 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3409 is an abbreviation for "of_nat :: nat => int". The simplification
  3410 rules for "of_nat" have been changed to work like "int" did
  3411 previously.  Potential INCOMPATIBILITY:
  3412   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3413   - of_nat_diff and of_nat_mult are no longer default simp rules
  3414 
  3415 * Method "algebra" solves polynomial equations over (semi)rings using
  3416 Groebner bases. The (semi)ring structure is defined by locales and the
  3417 tool setup depends on that generic context. Installing the method for
  3418 a specific type involves instantiating the locale and possibly adding
  3419 declarations for computation on the coefficients.  The method is
  3420 already instantiated for natural numbers and for the axiomatic class
  3421 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3422 CALCULEMUS 2007 for the general principles underlying this
  3423 architecture of context-aware proof-tools.
  3424 
  3425 * Method "ferrack" implements quantifier elimination over
  3426 special-purpose dense linear orders using locales (analogous to
  3427 "algebra"). The method is already installed for class
  3428 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3429 rat, etc.
  3430 
  3431 * Former constant "List.op @" now named "List.append".  Use ML
  3432 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3433 circumvent possible incompatibilities when working on ML level.
  3434 
  3435 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3436 
  3437 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3438 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3439 
  3440 * New syntax for Haskell-like list comprehension (input only), eg.
  3441 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3442 
  3443 * The special syntax for function "filter" has changed from [x :
  3444 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3445 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3446 
  3447 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3448 defined on nat only, as an abbreviation for [a..<Suc b]
  3449 INCOMPATIBILITY.
  3450 
  3451 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3452 
  3453 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3454 
  3455 * New lemma collection field_simps (an extension of ring_simps) for
  3456 manipulating (in)equations involving division. Multiplies with all
  3457 denominators that can be proved to be non-zero (in equations) or
  3458 positive/negative (in inequations).
  3459 
  3460 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3461 have been improved and renamed to ring_simps, group_simps and
  3462 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3463 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3464 
  3465 * Theory Library/Commutative_Ring: switched from recdef to function
  3466 package; constants add, mul, pow now curried.  Infix syntax for
  3467 algebraic operations.
  3468 
  3469 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3470 INCOMPATIBILITY.
  3471 
  3472 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3473 INCOMPATIBILITY.
  3474 
  3475 * HOL/records: generalised field-update to take a function on the
  3476 field rather than the new value: r(|A := x|) is translated to A_update
  3477 (K x) r The K-combinator that is internally used is called K_record.
  3478 INCOMPATIBILITY: Usage of the plain update functions has to be
  3479 adapted.
  3480  
  3481 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3482 * x = 0, which are required for a semiring.  Richer structures do not
  3483 inherit from semiring_0 anymore, because this property is a theorem
  3484 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3485 there is more to prove, but this is mostly trivial.
  3486 
  3487 * Class "recpower" is generalized to arbitrary monoids, not just
  3488 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3489 commutativity or semiring properties additionally.
  3490 
  3491 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3492 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3493 better use 'abbreviation'.
  3494 
  3495 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3496 
  3497 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3498 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3499 significant changes for setting up numeral syntax for types:
  3500   - New constants Numeral.pred and Numeral.succ instead
  3501       of former Numeral.bin_pred and Numeral.bin_succ.
  3502   - Use integer operations instead of bin_add, bin_mult and so on.
  3503   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3504   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3505 
  3506 See src/HOL/Integ/IntArith.thy for an example setup.
  3507 
  3508 * Command 'normal_form' computes the normal form of a term that may
  3509 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3510 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3511 heavy-duty computations because the functions are compiled to ML
  3512 first.  Correspondingly, a method "normalization" is provided.  See
  3513 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3514 
  3515 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3516 25 like -->); output depends on the "iff" print_mode, the default is
  3517 "A = B" (with priority 50).
  3518 
  3519 * Relations less (<) and less_eq (<=) are also available on type bool.
  3520 Modified syntax to disallow nesting without explicit parentheses,
  3521 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3522 INCOMPATIBILITY.
  3523 
  3524 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3525 
  3526 * Relation composition operator "op O" now has precedence 75 and binds
  3527 stronger than union and intersection. INCOMPATIBILITY.
  3528 
  3529 * The old set interval syntax "{m..n(}" (and relatives) has been
  3530 removed.  Use "{m..<n}" (and relatives) instead.
  3531 
  3532 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3533 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3534 ``declare [[simproc del: neq]]''.
  3535 
  3536 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3537 True/False.
  3538 
  3539 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3540 
  3541 * Theorem setsum_mult renamed to setsum_right_distrib.
  3542 
  3543 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3544 ``rule'' method.
  3545 
  3546 * Reimplemented methods "sat" and "satx", with several improvements:
  3547 goals no longer need to be stated as "<prems> ==> False", equivalences
  3548 (i.e. "=" on type bool) are handled, variable names of the form
  3549 "lit_<n>" are no longer reserved, significant speedup.
  3550 
  3551 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3552 zChaff is still supported as well.
  3553 
  3554 * 'inductive' and 'datatype': provide projections of mutual rules,
  3555 bundled as foo_bar.inducts;
  3556 
  3557 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3558 Library.
  3559 
  3560 * Library: moved theory Accessible_Part to main HOL.
  3561 
  3562 * Library: added theory Coinductive_List of potentially infinite lists
  3563 as greatest fixed-point.
  3564 
  3565 * Library: added theory AssocList which implements (finite) maps as
  3566 association lists.
  3567 
  3568 * Method "evaluation" solves goals (i.e. a boolean expression)
  3569 efficiently by compiling it to ML.  The goal is "proved" (via an
  3570 oracle) if it evaluates to True.
  3571 
  3572 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3573 also when invoked by the simplifier.  This results in the Simplifier
  3574 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3575 Configuration option fast_arith_split_limit=0 recovers the old
  3576 behavior.
  3577 
  3578 * Support for hex (0x20) and binary (0b1001) numerals.
  3579 
  3580 * New method: reify eqs (t), where eqs are equations for an
  3581 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3582 parameter, computes a term s::'b and a list xs::'a list and proves the
  3583 theorem I xs s = t. This is also known as reification or quoting. The
  3584 resulting theorem is applied to the subgoal to substitute t with I xs
  3585 s.  If t is omitted, the subgoal itself is reified.
  3586 
  3587 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3588 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3589 where f is supposed to be a computable function (in the sense of code
  3590 generattion). The method uses reify to compute s and xs as above then
  3591 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3592 r and finally gets the theorem t = r, which is again applied to the
  3593 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3594 
  3595 * Reflection: Automatic reification now handels binding, an example is
  3596 available in src/HOL/ex/ReflectionEx.thy
  3597 
  3598 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3599 command 'statespace' that is similar to 'record', but introduces an
  3600 abstract specification based on the locale infrastructure instead of
  3601 HOL types.  This leads to extra flexibility in composing state spaces,
  3602 in particular multiple inheritance and renaming of components.
  3603 
  3604 
  3605 *** HOL-Complex ***
  3606 
  3607 * Hyperreal: Functions root and sqrt are now defined on negative real
  3608 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3609 Nonnegativity side conditions have been removed from many lemmas, so
  3610 that more subgoals may now be solved by simplification; potential
  3611 INCOMPATIBILITY.
  3612 
  3613 * Real: new type classes formalize real normed vector spaces and
  3614 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3615 and norm :: 'a => real.
  3616 
  3617 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3618 reals into other types. The overloaded constant Reals :: 'a set is now
  3619 defined as range of_real; potential INCOMPATIBILITY.
  3620 
  3621 * Real: proper support for ML code generation, including 'quickcheck'.
  3622 Reals are implemented as arbitrary precision rationals.
  3623 
  3624 * Hyperreal: Several constants that previously worked only for the
  3625 reals have been generalized, so they now work over arbitrary vector
  3626 spaces. Type annotations may need to be added in some cases; potential
  3627 INCOMPATIBILITY.
  3628 
  3629   Infinitesimal  :: ('a::real_normed_vector) star set
  3630   HFinite        :: ('a::real_normed_vector) star set
  3631   HInfinite      :: ('a::real_normed_vector) star set
  3632   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3633   monad          :: ('a::real_normed_vector) star => 'a star set
  3634   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3635   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3636   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3637   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3638   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3639   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3640   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3641   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3642   sgn            :: 'a::real_normed_vector => 'a
  3643   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3644 
  3645 * Complex: Some complex-specific constants are now abbreviations for
  3646 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3647 hnorm.  Other constants have been entirely removed in favor of the
  3648 polymorphic versions (INCOMPATIBILITY):
  3649 
  3650   approx        <-- capprox
  3651   HFinite       <-- CFinite
  3652   HInfinite     <-- CInfinite
  3653   Infinitesimal <-- CInfinitesimal
  3654   monad         <-- cmonad
  3655   galaxy        <-- cgalaxy
  3656   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3657   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3658   (ns)deriv     <-- (ns)cderiv
  3659 
  3660 
  3661 *** HOL-Algebra ***
  3662 
  3663 * Formalisation of ideals and the quotient construction over rings.
  3664 
  3665 * Order and lattice theory no longer based on records.
  3666 INCOMPATIBILITY.
  3667 
  3668 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3669 greatest_closed.  INCOMPATIBILITY.
  3670 
  3671 * Method algebra is now set up via an attribute.  For examples see
  3672 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3673 of algebraic structures.
  3674 
  3675 * Renamed theory CRing to Ring.
  3676 
  3677 
  3678 *** HOL-Nominal ***
  3679 
  3680 * Substantial, yet incomplete support for nominal datatypes (binding
  3681 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3682 src/HOL/Nominal/Examples.  Prospective users should consult
  3683 http://isabelle.in.tum.de/nominal/
  3684 
  3685 
  3686 *** ML ***
  3687 
  3688 * ML basics: just one true type int, which coincides with IntInf.int
  3689 (even on SML/NJ).
  3690 
  3691 * ML within Isar: antiquotations allow to embed statically-checked
  3692 formal entities in the source, referring to the context available at
  3693 compile-time.  For example:
  3694 
  3695 ML {* @{sort "{zero,one}"} *}
  3696 ML {* @{typ "'a => 'b"} *}
  3697 ML {* @{term "%x. x"} *}
  3698 ML {* @{prop "x == y"} *}
  3699 ML {* @{ctyp "'a => 'b"} *}
  3700 ML {* @{cterm "%x. x"} *}
  3701 ML {* @{cprop "x == y"} *}
  3702 ML {* @{thm asm_rl} *}
  3703 ML {* @{thms asm_rl} *}
  3704 ML {* @{type_name c} *}
  3705 ML {* @{type_syntax c} *}
  3706 ML {* @{const_name c} *}
  3707 ML {* @{const_syntax c} *}
  3708 ML {* @{context} *}
  3709 ML {* @{theory} *}
  3710 ML {* @{theory Pure} *}
  3711 ML {* @{theory_ref} *}
  3712 ML {* @{theory_ref Pure} *}
  3713 ML {* @{simpset} *}
  3714 ML {* @{claset} *}
  3715 ML {* @{clasimpset} *}
  3716 
  3717 The same works for sources being ``used'' within an Isar context.
  3718 
  3719 * ML in Isar: improved error reporting; extra verbosity with
  3720 ML_Context.trace enabled.
  3721 
  3722 * Pure/General/table.ML: the join operations now works via exceptions
  3723 DUP/SAME instead of type option. This is simpler in simple cases, and
  3724 admits slightly more efficient complex applications.
  3725 
  3726 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3727 use Context.generic instead of just theory.
  3728 
  3729 * Pure: datatype Context.generic joins theory/Proof.context and
  3730 provides some facilities for code that works in either kind of
  3731 context, notably GenericDataFun for uniform theory and proof data.
  3732 
  3733 * Pure: simplified internal attribute type, which is now always
  3734 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3735 local (Proof.context) attributes have been discontinued, while
  3736 minimizing code duplication. Thm.rule_attribute and
  3737 Thm.declaration_attribute build canonical attributes; see also structure
  3738 Context for further operations on Context.generic, notably
  3739 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3740 declarations and definitions.
  3741 
  3742 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3743 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3744 init only required for impure data. INCOMPATIBILITY: empty really need
  3745 to be empty (no dependencies on theory content!)
  3746 
  3747 * Pure/kernel: consts certification ignores sort constraints given in
  3748 signature declarations. (This information is not relevant to the
  3749 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3750 potential INCOMPATIBILITY.
  3751 
  3752 * Pure: axiomatic type classes are now purely definitional, with
  3753 explicit proofs of class axioms and super class relations performed
  3754 internally. See Pure/axclass.ML for the main internal interfaces --
  3755 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3756 AxClass.axiomatize_class/classrel/arity supersede
  3757 Sign.add_classes/classrel/arities.
  3758 
  3759 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3760 global/local versions on theory vs. Proof.context have been
  3761 discontinued; Attrib.syntax and Method.syntax have been adapted
  3762 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3763 attributes, methods, etc.
  3764 
  3765 * Pure: several functions of signature "... -> theory -> theory * ..."
  3766 have been reoriented to "... -> theory -> ... * theory" in order to
  3767 allow natural usage in combination with the ||>, ||>>, |-> and
  3768 fold_map combinators.
  3769 
  3770 * Pure: official theorem names (closed derivations) and additional
  3771 comments (tags) are now strictly separate.  Name hints -- which are
  3772 maintained as tags -- may be attached any time without affecting the
  3773 derivation.
  3774 
  3775 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3776 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3777 achieve the old behaviour.
  3778 
  3779 * Pure: the "Goal" constant is now called "prop", supporting a
  3780 slightly more general idea of ``protecting'' meta-level rule
  3781 statements.
  3782 
  3783 * Pure: Logic.(un)varify only works in a global context, which is now
  3784 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3785 Logic.legacy_(un)varify as temporary workaround.
  3786 
  3787 * Pure: structure Name provides scalable operations for generating
  3788 internal variable names, notably Name.variants etc.  This replaces
  3789 some popular functions from term.ML:
  3790 
  3791   Term.variant		->  Name.variant
  3792   Term.variantlist	->  Name.variant_list
  3793   Term.invent_names	->  Name.invent_list
  3794 
  3795 Note that low-level renaming rarely occurs in new code -- operations
  3796 from structure Variable are used instead (see below).
  3797 
  3798 * Pure: structure Variable provides fundamental operations for proper
  3799 treatment of fixed/schematic variables in a context.  For example,
  3800 Variable.import introduces fixes for schematics of given facts and
  3801 Variable.export reverses the effect (up to renaming) -- this replaces
  3802 various freeze_thaw operations.
  3803 
  3804 * Pure: structure Goal provides simple interfaces for
  3805 init/conclude/finish and tactical prove operations (replacing former
  3806 Tactic.prove).  Goal.prove is the canonical way to prove results
  3807 within a given context; Goal.prove_global is a degraded version for
  3808 theory level goals, including a global Drule.standard.  Note that
  3809 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3810 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3811 in a locale context).
  3812 
  3813 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3814 and type checking (Syntax.check_term etc.), with common combinations
  3815 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3816 which are considered legacy and await removal.
  3817 
  3818 * Pure/Syntax: generic interfaces for type unchecking
  3819 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3820 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3821 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3822 available for convenience, but refer to the very same operations using
  3823 a mere theory instead of a full context.
  3824 
  3825 * Isar: simplified treatment of user-level errors, using exception
  3826 ERROR of string uniformly.  Function error now merely raises ERROR,
  3827 without any side effect on output channels.  The Isar toplevel takes
  3828 care of proper display of ERROR exceptions.  ML code may use plain
  3829 handle/can/try; cat_error may be used to concatenate errors like this:
  3830 
  3831   ... handle ERROR msg => cat_error msg "..."
  3832 
  3833 Toplevel ML code (run directly or through the Isar toplevel) may be
  3834 embedded into the Isar toplevel with exception display/debug like
  3835 this:
  3836 
  3837   Isar.toplevel (fn () => ...)
  3838 
  3839 INCOMPATIBILITY, removed special transform_error facilities, removed
  3840 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3841 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3842 -- use plain ERROR instead.
  3843 
  3844 * Isar: theory setup now has type (theory -> theory), instead of a
  3845 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3846 
  3847 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3848 ProofContext.debug/verbose flags.
  3849 
  3850 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3851 theory before entering a proof state.  Transactions now always see a
  3852 quasi-functional intermediate checkpoint, both in interactive and
  3853 batch mode.
  3854 
  3855 * Isar: simplified interfaces for outer syntax.  Renamed
  3856 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3857 OuterSyntax.add_parsers -- this functionality is now included in
  3858 OuterSyntax.command etc.  INCOMPATIBILITY.
  3859 
  3860 * Simplifier: the simpset of a running simplification process now
  3861 contains a proof context (cf. Simplifier.the_context), which is the
  3862 very context that the initial simpset has been retrieved from (by
  3863 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3864 (solver, looper etc.) may depend on arbitrary proof data.
  3865 
  3866 * Simplifier.inherit_context inherits the proof context (plus the
  3867 local bounds) of the current simplification process; any simproc
  3868 etc. that calls the Simplifier recursively should do this!  Removed
  3869 former Simplifier.inherit_bounds, which is already included here --
  3870 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3871 specify an explicit context using Simplifier.context/theory_context.
  3872 
  3873 * Simplifier/Classical Reasoner: more abstract interfaces
  3874 change_simpset/claset for modifying the simpset/claset reference of a
  3875 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3876 INCOMPATIBILITY.
  3877 
  3878 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3879 "Trueprop" etc.
  3880 
  3881 
  3882 *** System ***
  3883 
  3884 * settings: the default heap location within ISABELLE_HOME_USER now
  3885 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3886 Isabelle installations.
  3887 
  3888 * isabelle-process: option -S (secure mode) disables some critical
  3889 operations, notably runtime compilation and evaluation of ML source
  3890 code.
  3891 
  3892 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3893 
  3894 * Support for parallel execution, using native multicore support of
  3895 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3896 independent theories, according to the given theory header
  3897 specifications. The maximum number of worker threads is specified via
  3898 usedir option -M or the "max-threads" setting in Proof General. A
  3899 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3900 to 6 on a 8-core machine.  User-code needs to observe certain
  3901 guidelines for thread-safe programming, see appendix A in the Isar
  3902 Implementation manual.
  3903 
  3904 
  3905 
  3906 New in Isabelle2005 (October 2005)
  3907 ----------------------------------
  3908 
  3909 *** General ***
  3910 
  3911 * Theory headers: the new header syntax for Isar theories is
  3912 
  3913   theory <name>
  3914   imports <theory1> ... <theoryN>
  3915   uses <file1> ... <fileM>
  3916   begin
  3917 
  3918 where the 'uses' part is optional.  The previous syntax
  3919 
  3920   theory <name> = <theory1> + ... + <theoryN>:
  3921 
  3922 will disappear in the next release.  Use isatool fixheaders to convert
  3923 existing theory files.  Note that there is no change in ancient
  3924 non-Isar theories now, but these will disappear soon.
  3925 
  3926 * Theory loader: parent theories can now also be referred to via
  3927 relative and absolute paths.
  3928 
  3929 * Command 'find_theorems' searches for a list of criteria instead of a
  3930 list of constants. Known criteria are: intro, elim, dest, name:string,
  3931 simp:term, and any term. Criteria can be preceded by '-' to select
  3932 theorems that do not match. Intro, elim, dest select theorems that
  3933 match the current goal, name:s selects theorems whose fully qualified
  3934 name contain s, and simp:term selects all simplification rules whose
  3935 lhs match term.  Any other term is interpreted as pattern and selects
  3936 all theorems matching the pattern. Available in ProofGeneral under
  3937 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3938 
  3939   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3940 
  3941 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3942 matching the current goal as introduction rule and not having "HOL."
  3943 in their name (i.e. not being defined in theory HOL).
  3944 
  3945 * Command 'thms_containing' has been discontinued in favour of
  3946 'find_theorems'; INCOMPATIBILITY.
  3947 
  3948 * Communication with Proof General is now 8bit clean, which means that
  3949 Unicode text in UTF-8 encoding may be used within theory texts (both
  3950 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3951 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3952 
  3953   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3954   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3955 
  3956 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3957 Classical Reasoner.  Typical big applications run around 2 times
  3958 faster.
  3959 
  3960 
  3961 *** Document preparation ***
  3962 
  3963 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3964 of raw sources.  Only those symbols that do not require additional
  3965 LaTeX packages (depending on comments in isabellesym.sty) are
  3966 displayed properly, everything else is left verbatim.  isatool display
  3967 and isatool print are used as front ends (these are subject to the
  3968 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3969 
  3970 * Command tags control specific markup of certain regions of text,
  3971 notably folding and hiding.  Predefined tags include "theory" (for
  3972 theory begin and end), "proof" for proof commands, and "ML" for
  3973 commands involving ML code; the additional tags "visible" and
  3974 "invisible" are unused by default.  Users may give explicit tag
  3975 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3976 interpretation of tags is determined by the LaTeX job during document
  3977 preparation: see option -V of isatool usedir, or options -n and -t of
  3978 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3979 \isadroptag.
  3980 
  3981 Several document versions may be produced at the same time via isatool
  3982 usedir (the generated index.html will link all of them).  Typical
  3983 specifications include ''-V document=theory,proof,ML'' to present
  3984 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3985 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3986 these parts without any formal replacement text.  The Isabelle site
  3987 default settings produce ''document'' and ''outline'' versions as
  3988 specified above.
  3989 
  3990 * Several new antiquotations:
  3991 
  3992   @{term_type term} prints a term with its type annotated;
  3993 
  3994   @{typeof term} prints the type of a term;
  3995 
  3996   @{const const} is the same as @{term const}, but checks that the
  3997   argument is a known logical constant;
  3998 
  3999   @{term_style style term} and @{thm_style style thm} print a term or
  4000   theorem applying a "style" to it
  4001 
  4002   @{ML text}
  4003 
  4004 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4005 definitions, equations, inequations etc., 'concl' printing only the
  4006 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4007 to print the specified premise.  TermStyle.add_style provides an ML
  4008 interface for introducing further styles.  See also the "LaTeX Sugar"
  4009 document practical applications.  The ML antiquotation prints
  4010 type-checked ML expressions verbatim.
  4011 
  4012 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4013 and 'text' support optional locale specification '(in loc)', which
  4014 specifies the default context for interpreting antiquotations.  For
  4015 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4016 
  4017 * Option 'locale=NAME' of antiquotations specifies an alternative
  4018 context interpreting the subsequent argument.  For example: @{thm
  4019 [locale=lattice] inf_assoc}.
  4020 
  4021 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4022 a proof context.
  4023 
  4024 * Proper output of antiquotations for theory commands involving a
  4025 proof context (such as 'locale' or 'theorem (in loc) ...').
  4026 
  4027 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4028 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4029 
  4030 * isatool usedir: new option -C (default true) controls whether option
  4031 -D should include a copy of the original document directory; -C false
  4032 prevents unwanted effects such as copying of administrative CVS data.
  4033 
  4034 
  4035 *** Pure ***
  4036 
  4037 * Considerably improved version of 'constdefs' command.  Now performs
  4038 automatic type-inference of declared constants; additional support for
  4039 local structure declarations (cf. locales and HOL records), see also
  4040 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4041 sequential dependencies of definitions within a single 'constdefs'
  4042 section; moreover, the declared name needs to be an identifier.  If
  4043 all fails, consider to fall back on 'consts' and 'defs' separately.
  4044 
  4045 * Improved indexed syntax and implicit structures.  First of all,
  4046 indexed syntax provides a notational device for subscripted
  4047 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4048 expressions.  Secondly, in a local context with structure
  4049 declarations, number indexes \<^sub>n or the empty index (default
  4050 number 1) refer to a certain fixed variable implicitly; option
  4051 show_structs controls printing of implicit structures.  Typical
  4052 applications of these concepts involve record types and locales.
  4053 
  4054 * New command 'no_syntax' removes grammar declarations (and
  4055 translations) resulting from the given syntax specification, which is
  4056 interpreted in the same manner as for the 'syntax' command.
  4057 
  4058 * 'Advanced' translation functions (parse_translation etc.) may depend
  4059 on the signature of the theory context being presently used for
  4060 parsing/printing, see also isar-ref manual.
  4061 
  4062 * Improved 'oracle' command provides a type-safe interface to turn an
  4063 ML expression of type theory -> T -> term into a primitive rule of
  4064 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4065 is already included here); see also FOL/ex/IffExample.thy;
  4066 INCOMPATIBILITY.
  4067 
  4068 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4069 before); "cI" is no longer bound, use "c.intro" instead.
  4070 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4071 axclasses vs. locales.
  4072 
  4073 * Improved internal renaming of symbolic identifiers -- attach primes
  4074 instead of base 26 numbers.
  4075 
  4076 * New flag show_question_marks controls printing of leading question
  4077 marks in schematic variable names.
  4078 
  4079 * In schematic variable names, *any* symbol following \<^isub> or
  4080 \<^isup> is now treated as part of the base name.  For example, the
  4081 following works without printing of awkward ".0" indexes:
  4082 
  4083   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4084     by simp
  4085 
  4086 * Inner syntax includes (*(*nested*) comments*).
  4087 
  4088 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4089 annotations as "(00...)".
  4090 
  4091 * Clear separation of logical types and nonterminals, where the latter
  4092 may only occur in 'syntax' specifications or type abbreviations.
  4093 Before that distinction was only partially implemented via type class
  4094 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4095 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4096 exotic syntax specifications may require further adaption
  4097 (e.g. Cube/Cube.thy).
  4098 
  4099 * Removed obsolete type class "logic", use the top sort {} instead.
  4100 Note that non-logical types should be declared as 'nonterminals'
  4101 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4102 specifications.
  4103 
  4104 * Attributes 'induct' and 'cases': type or set names may now be
  4105 locally fixed variables as well.
  4106 
  4107 * Simplifier: can now control the depth to which conditional rewriting
  4108 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4109 Limit.
  4110 
  4111 * Simplifier: simplification procedures may now take the current
  4112 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4113 interface), which is very useful for calling the Simplifier
  4114 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4115 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4116 low-level mk_simproc no longer applies Logic.varify internally, to
  4117 allow for use in a context of fixed variables.
  4118 
  4119 * thin_tac now works even if the assumption being deleted contains !!
  4120 or ==>.  More generally, erule now works even if the major premise of
  4121 the elimination rule contains !! or ==>.
  4122 
  4123 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4124 
  4125 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4126 from Pure, which contains all common declarations already.  Both
  4127 theories are defined via plain Isabelle/Isar .thy files.
  4128 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4129 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4130 use isatool fixcpure to adapt your theory and ML sources.
  4131 
  4132 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4133 selections of theorems in named facts via index ranges.
  4134 
  4135 * 'print_theorems': in theory mode, really print the difference
  4136 wrt. the last state (works for interactive theory development only),
  4137 in proof mode print all local facts (cf. 'print_facts');
  4138 
  4139 * 'hide': option '(open)' hides only base names.
  4140 
  4141 * More efficient treatment of intermediate checkpoints in interactive
  4142 theory development.
  4143 
  4144 * Code generator is now invoked via code_module (incremental code
  4145 generation) and code_library (modular code generation, ML structures
  4146 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4147 must be quoted when used as identifiers.
  4148 
  4149 * New 'value' command for reading, evaluating and printing terms using
  4150 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4151 quoted when used as identifier.
  4152 
  4153 
  4154 *** Locales ***
  4155 
  4156 * New commands for the interpretation of locale expressions in
  4157 theories (1), locales (2) and proof contexts (3).  These generate
  4158 proof obligations from the expression specification.  After the
  4159 obligations have been discharged, theorems of the expression are added
  4160 to the theory, target locale or proof context.  The synopsis of the
  4161 commands is a follows:
  4162 
  4163   (1) interpretation expr inst
  4164   (2) interpretation target < expr
  4165   (3) interpret expr inst
  4166 
  4167 Interpretation in theories and proof contexts require a parameter
  4168 instantiation of terms from the current context.  This is applied to
  4169 specifications and theorems of the interpreted expression.
  4170 Interpretation in locales only permits parameter renaming through the
  4171 locale expression.  Interpretation is smart in that interpretations
  4172 that are active already do not occur in proof obligations, neither are
  4173 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4174 inspect active interpretations of a particular locale.  For details,
  4175 see the Isar Reference manual.  Examples can be found in
  4176 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4177 
  4178 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4179 'interpret' instead.
  4180 
  4181 * New context element 'constrains' for adding type constraints to
  4182 parameters.
  4183 
  4184 * Context expressions: renaming of parameters with syntax
  4185 redeclaration.
  4186 
  4187 * Locale declaration: 'includes' disallowed.
  4188 
  4189 * Proper static binding of attribute syntax -- i.e. types / terms /
  4190 facts mentioned as arguments are always those of the locale definition
  4191 context, independently of the context of later invocations.  Moreover,
  4192 locale operations (renaming and type / term instantiation) are applied
  4193 to attribute arguments as expected.
  4194 
  4195 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4196 actual attributes; rare situations may require Attrib.attribute to
  4197 embed those attributes into Attrib.src that lack concrete syntax.
  4198 Attribute implementations need to cooperate properly with the static
  4199 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4200 Attrib.XXX_thm etc. already do the right thing without further
  4201 intervention.  Only unusual applications -- such as "where" or "of"
  4202 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4203 on the context and the facts involved -- may have to assign parsed
  4204 values to argument tokens explicitly.
  4205 
  4206 * Changed parameter management in theorem generation for long goal
  4207 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4208 theorem statement in rare situations.
  4209 
  4210 * Locale inspection command 'print_locale' omits notes elements.  Use
  4211 'print_locale!' to have them included in the output.
  4212 
  4213 
  4214 *** Provers ***
  4215 
  4216 * Provers/hypsubst.ML: improved version of the subst method, for
  4217 single-step rewriting: it now works in bound variable contexts. New is
  4218 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4219 rewrite a different subterm than the original subst method, which is
  4220 still available as 'simplesubst'.
  4221 
  4222 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4223 and quasi orders.
  4224 
  4225 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4226 reflexive-transitive closure of relations.
  4227 
  4228 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4229 limit (previously hard-coded with a value of 20) user-definable.
  4230 
  4231 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4232 is peformed already.  Object-logics merely need to finish their
  4233 initial simpset configuration as before.  INCOMPATIBILITY.
  4234 
  4235 
  4236 *** HOL ***
  4237 
  4238 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4239 
  4240   syntax (epsilon)
  4241     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4242 
  4243 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4244 and x-symbol; use option '-m epsilon' to get it actually printed.
  4245 Moreover, the mathematically important symbolic identifier \<epsilon>
  4246 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4247 
  4248 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4249 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4250 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4251 support corresponding Isar calculations.
  4252 
  4253 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4254 instead of ":".
  4255 
  4256 * theory SetInterval: changed the syntax for open intervals:
  4257 
  4258   Old       New
  4259   {..n(}    {..<n}
  4260   {)n..}    {n<..}
  4261   {m..n(}   {m..<n}
  4262   {)m..n}   {m<..n}
  4263   {)m..n(}  {m<..<n}
  4264 
  4265 The old syntax is still supported but will disappear in the next
  4266 release.  For conversion use the following Emacs search and replace
  4267 patterns (these are not perfect but work quite well):
  4268 
  4269   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4270   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4271 
  4272 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4273 equalities in commutative rings; method 'algebra' provides a generic
  4274 interface.
  4275 
  4276 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4277 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4278 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4279 be a tuple pattern.
  4280 
  4281 Some new syntax forms are available:
  4282 
  4283   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4284   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4285   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4286   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4287 
  4288 The latter form "\<Sum>x < k. e" used to be based on a separate
  4289 function "Summation", which has been discontinued.
  4290 
  4291 * theory Finite_Set: in structured induction proofs, the insert case
  4292 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4293 (insert F x)'.
  4294 
  4295 * The 'refute' command has been extended to support a much larger
  4296 fragment of HOL, including axiomatic type classes, constdefs and
  4297 typedefs, inductive datatypes and recursion.
  4298 
  4299 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4300 Requires zChaff with proof generation to be installed.  See
  4301 HOL/ex/SAT_Examples.thy for examples.
  4302 
  4303 * Datatype induction via method 'induct' now preserves the name of the
  4304 induction variable. For example, when proving P(xs::'a list) by
  4305 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4306 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4307 in unstructured proof scripts.
  4308 
  4309 * Reworked implementation of records.  Improved scalability for
  4310 records with many fields, avoiding performance problems for type
  4311 inference. Records are no longer composed of nested field types, but
  4312 of nested extension types. Therefore the record type only grows linear
  4313 in the number of extensions and not in the number of fields.  The
  4314 top-level (users) view on records is preserved.  Potential
  4315 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4316 old record representation. The type generated for a record is called
  4317 <record_name>_ext_type.
  4318 
  4319 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4320 proofs triggered by a record definition or a simproc (if
  4321 quick_and_dirty is enabled).  Definitions of large records can take
  4322 quite long.
  4323 
  4324 New simproc record_upd_simproc for simplification of multiple record
  4325 updates enabled by default.  Moreover, trivial updates are also
  4326 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4327 occasionally, since simplification is more powerful by default.
  4328 
  4329 * typedef: proper support for polymorphic sets, which contain extra
  4330 type-variables in the term.
  4331 
  4332 * Simplifier: automatically reasons about transitivity chains
  4333 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4334 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4335 old proofs break occasionally as simplification may now solve more
  4336 goals than previously.
  4337 
  4338 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4339 present.  Works for all partial orders (class "order"), in particular
  4340 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4341 just like y <= x.
  4342 
  4343 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4344 bound variable or a constant then the let is unfolded.  Otherwise
  4345 first a is simplified to b, and then f b is simplified to g. If
  4346 possible we abstract b from g arriving at "let x = b in h x",
  4347 otherwise we unfold the let and arrive at g.  The simproc can be
  4348 enabled/disabled by the reference use_let_simproc.  Potential
  4349 INCOMPATIBILITY since simplification is more powerful by default.
  4350 
  4351 * Classical reasoning: the meson method now accepts theorems as arguments.
  4352 
  4353 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4354 jobs to provide advice on the provability of subgoals.
  4355 
  4356 * Theory OrderedGroup and Ring_and_Field: various additions and
  4357 improvements to faciliate calculations involving equalities and
  4358 inequalities.
  4359 
  4360 The following theorems have been eliminated or modified
  4361 (INCOMPATIBILITY):
  4362 
  4363   abs_eq             now named abs_of_nonneg
  4364   abs_of_ge_0        now named abs_of_nonneg
  4365   abs_minus_eq       now named abs_of_nonpos
  4366   imp_abs_id         now named abs_of_nonneg
  4367   imp_abs_neg_id     now named abs_of_nonpos
  4368   mult_pos           now named mult_pos_pos
  4369   mult_pos_le        now named mult_nonneg_nonneg
  4370   mult_pos_neg_le    now named mult_nonneg_nonpos
  4371   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4372   mult_neg           now named mult_neg_neg
  4373   mult_neg_le        now named mult_nonpos_nonpos
  4374 
  4375 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4376      
  4377      zero_le_square
  4378      not_square_less_zero 
  4379 
  4380   The following lemmas have been deleted from Real/RealPow:
  4381   
  4382      realpow_zero_zero
  4383      realpow_two
  4384      realpow_less
  4385      zero_le_power
  4386      realpow_two_le
  4387      abs_realpow_two
  4388      realpow_two_abs     
  4389 
  4390 * Theory Parity: added rules for simplifying exponents.
  4391 
  4392 * Theory List:
  4393 
  4394 The following theorems have been eliminated or modified
  4395 (INCOMPATIBILITY):
  4396 
  4397   list_all_Nil       now named list_all.simps(1)
  4398   list_all_Cons      now named list_all.simps(2)
  4399   list_all_conv      now named list_all_iff
  4400   set_mem_eq         now named mem_iff
  4401 
  4402 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4403 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4404 
  4405 
  4406 *** HOL-Complex ***
  4407 
  4408 * Theory RealDef: better support for embedding natural numbers and
  4409 integers in the reals.
  4410 
  4411 The following theorems have been eliminated or modified
  4412 (INCOMPATIBILITY):
  4413 
  4414   exp_ge_add_one_self  now requires no hypotheses
  4415   real_of_int_add      reversed direction of equality (use [symmetric])
  4416   real_of_int_minus    reversed direction of equality (use [symmetric])
  4417   real_of_int_diff     reversed direction of equality (use [symmetric])
  4418   real_of_int_mult     reversed direction of equality (use [symmetric])
  4419 
  4420 * Theory RComplete: expanded support for floor and ceiling functions.
  4421 
  4422 * Theory Ln is new, with properties of the natural logarithm
  4423 
  4424 * Hyperreal: There is a new type constructor "star" for making
  4425 nonstandard types.  The old type names are now type synonyms:
  4426 
  4427   hypreal = real star
  4428   hypnat = nat star
  4429   hcomplex = complex star
  4430 
  4431 * Hyperreal: Many groups of similarly-defined constants have been
  4432 replaced by polymorphic versions (INCOMPATIBILITY):
  4433 
  4434   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4435 
  4436   starset      <-- starsetNat, starsetC
  4437   *s*          <-- *sNat*, *sc*
  4438   starset_n    <-- starsetNat_n, starsetC_n
  4439   *sn*         <-- *sNatn*, *scn*
  4440   InternalSets <-- InternalNatSets, InternalCSets
  4441 
  4442   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4443   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4444   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4445   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4446   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4447 
  4448 * Hyperreal: Many type-specific theorems have been removed in favor of
  4449 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4450 
  4451   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4452   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4453   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4454   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4455   right_minus <-- hypreal_add_minus
  4456   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4457   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4458   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4459   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4460   mult_1_right <-- hcomplex_mult_one_right
  4461   mult_zero_left <-- hcomplex_mult_zero_left
  4462   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4463   right_distrib <-- hypnat_add_mult_distrib2
  4464   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4465   right_inverse <-- hypreal_mult_inverse
  4466   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4467   order_refl <-- {hypreal,hypnat}_le_refl
  4468   order_trans <-- {hypreal,hypnat}_le_trans
  4469   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4470   order_less_le <-- {hypreal,hypnat}_less_le
  4471   linorder_linear <-- {hypreal,hypnat}_le_linear
  4472   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4473   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4474   add_nonneg_nonneg <-- hypreal_le_add_order
  4475 
  4476 * Hyperreal: Separate theorems having to do with type-specific
  4477 versions of constants have been merged into theorems that apply to the
  4478 new polymorphic constants (INCOMPATIBILITY):
  4479 
  4480   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4481   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4482   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4483   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4484   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4485   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4486   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4487   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4488   STAR_diff <-- {STAR,STARC}_diff
  4489   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4490     STARC_hcomplex_of_complex}_image_subset
  4491   starset_n_Un <-- starset{Nat,C}_n_Un
  4492   starset_n_Int <-- starset{Nat,C}_n_Int
  4493   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4494   starset_n_diff <-- starset{Nat,C}_n_diff
  4495   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4496   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4497   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4498   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4499   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4500   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4501   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4502   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4503   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4504   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4505   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4506   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4507   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4508   starfun_diff <-- starfun{C,RC,CR}_diff
  4509   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4510   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4511   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4512   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4513   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4514   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4515   starfun_Id <-- starfunC_Id
  4516   starfun_approx <-- starfun{Nat,CR}_approx
  4517   starfun_capprox <-- starfun{C,RC}_capprox
  4518   starfun_abs <-- starfunNat_rabs
  4519   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4520   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4521   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4522   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4523   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4524   starfun_add_approx <-- starfunCR_add_approx
  4525   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4526   starfun_divide <-- starfun{C,CR,RC}_divide
  4527   starfun_n <-- starfun{Nat,C}_n
  4528   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4529   starfun_n_add <-- starfun{Nat,C}_n_add
  4530   starfun_n_add_minus <-- starfunNat_n_add_minus
  4531   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4532   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4533   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4534 
  4535   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4536   star_n_minus <-- {hypreal,hcomplex}_minus
  4537   star_n_diff <-- {hypreal,hcomplex}_diff
  4538   star_n_mult <-- {hypreal,hcomplex}_mult
  4539   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4540   star_n_le <-- {hypreal,hypnat}_le
  4541   star_n_less <-- {hypreal,hypnat}_less
  4542   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4543   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4544   star_n_abs <-- hypreal_hrabs
  4545   star_n_divide <-- hcomplex_divide
  4546 
  4547   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4548   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4549   star_of_diff <-- hypreal_of_real_diff
  4550   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4551   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4552   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4553   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4554   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4555   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4556   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4557   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4558   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4559   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4560   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4561   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4562   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4563   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4564   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4565   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4566   star_of_power <-- hypreal_of_real_power
  4567   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4568 
  4569 * Hyperreal: new method "transfer" that implements the transfer
  4570 principle of nonstandard analysis. With a subgoal that mentions
  4571 nonstandard types like "'a star", the command "apply transfer"
  4572 replaces it with an equivalent one that mentions only standard types.
  4573 To be successful, all free variables must have standard types; non-
  4574 standard variables must have explicit universal quantifiers.
  4575 
  4576 * Hyperreal: A theory of Taylor series.
  4577 
  4578 
  4579 *** HOLCF ***
  4580 
  4581 * Discontinued special version of 'constdefs' (which used to support
  4582 continuous functions) in favor of the general Pure one with full
  4583 type-inference.
  4584 
  4585 * New simplification procedure for solving continuity conditions; it
  4586 is much faster on terms with many nested lambda abstractions (cubic
  4587 instead of exponential time).
  4588 
  4589 * New syntax for domain package: selector names are now optional.
  4590 Parentheses should be omitted unless argument is lazy, for example:
  4591 
  4592   domain 'a stream = cons "'a" (lazy "'a stream")
  4593 
  4594 * New command 'fixrec' for defining recursive functions with pattern
  4595 matching; defining multiple functions with mutual recursion is also
  4596 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4597 sinr, or any data constructor defined by the domain package. The given
  4598 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4599 syntax and examples.
  4600 
  4601 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4602 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4603 but the proof obligation additionally includes an admissibility
  4604 requirement. The packages generate instances of class cpo or pcpo,
  4605 with continuity and strictness theorems for Rep and Abs.
  4606 
  4607 * HOLCF: Many theorems have been renamed according to a more standard naming
  4608 scheme (INCOMPATIBILITY):
  4609 
  4610   foo_inject:  "foo$x = foo$y ==> x = y"
  4611   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4612   foo_less:    "(foo$x << foo$y) = (x << y)"
  4613   foo_strict:  "foo$UU = UU"
  4614   foo_defined: "... ==> foo$x ~= UU"
  4615   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4616 
  4617 
  4618 *** ZF ***
  4619 
  4620 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4621 including the First Isomorphism Theorem (on quotienting by the kernel
  4622 of a homomorphism).
  4623 
  4624 * ZF/Simplifier: install second copy of type solver that actually
  4625 makes use of TC rules declared to Isar proof contexts (or locales);
  4626 the old version is still required for ML proof scripts.
  4627 
  4628 
  4629 *** Cube ***
  4630 
  4631 * Converted to Isar theory format; use locales instead of axiomatic
  4632 theories.
  4633 
  4634 
  4635 *** ML ***
  4636 
  4637 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4638 for ||>, ||>>, |>>,
  4639 
  4640 * Pure/library.ML no longer defines its own option datatype, but uses
  4641 that of the SML basis, which has constructors NONE and SOME instead of
  4642 None and Some, as well as exception Option.Option instead of OPTION.
  4643 The functions the, if_none, is_some, is_none have been adapted
  4644 accordingly, while Option.map replaces apsome.
  4645 
  4646 * Pure/library.ML: the exception LIST has been given up in favour of
  4647 the standard exceptions Empty and Subscript, as well as
  4648 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4649 superceded by the standard hd and tl functions etc.
  4650 
  4651 A number of basic list functions are no longer exported to the ML
  4652 toplevel, as they are variants of predefined functions.  The following
  4653 suggests how one can translate existing code:
  4654 
  4655     rev_append xs ys = List.revAppend (xs, ys)
  4656     nth_elem (i, xs) = List.nth (xs, i)
  4657     last_elem xs = List.last xs
  4658     flat xss = List.concat xss
  4659     seq fs = List.app fs
  4660     partition P xs = List.partition P xs
  4661     mapfilter f xs = List.mapPartial f xs
  4662 
  4663 * Pure/library.ML: several combinators for linear functional
  4664 transformations, notably reverse application and composition:
  4665 
  4666   x |> f                f #> g
  4667   (x, y) |-> f          f #-> g
  4668 
  4669 * Pure/library.ML: introduced/changed precedence of infix operators:
  4670 
  4671   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4672   infix 2 ?;
  4673   infix 3 o oo ooo oooo;
  4674   infix 4 ~~ upto downto;
  4675 
  4676 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4677 infix operators.
  4678 
  4679 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4680 fold_map support linear functional transformations and nesting.  For
  4681 example:
  4682 
  4683   fold f [x1, ..., xN] y =
  4684     y |> f x1 |> ... |> f xN
  4685 
  4686   (fold o fold) f [xs1, ..., xsN] y =
  4687     y |> fold f xs1 |> ... |> fold f xsN
  4688 
  4689   fold f [x1, ..., xN] =
  4690     f x1 #> ... #> f xN
  4691 
  4692   (fold o fold) f [xs1, ..., xsN] =
  4693     fold f xs1 #> ... #> fold f xsN
  4694 
  4695 * Pure/library.ML: the following selectors on type 'a option are
  4696 available:
  4697 
  4698   the:               'a option -> 'a  (*partial*)
  4699   these:             'a option -> 'a  where 'a = 'b list
  4700   the_default: 'a -> 'a option -> 'a
  4701   the_list:          'a option -> 'a list
  4702 
  4703 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4704 basic operations for association lists, following natural argument
  4705 order; moreover the explicit equality predicate passed here avoids
  4706 potentially expensive polymorphic runtime equality checks.
  4707 The old functions may be expressed as follows:
  4708 
  4709   assoc = uncurry (AList.lookup (op =))
  4710   assocs = these oo AList.lookup (op =)
  4711   overwrite = uncurry (AList.update (op =)) o swap
  4712 
  4713 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4714 
  4715   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4716   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4717 
  4718 replacing make_keylist and keyfilter (occassionally used)
  4719 Naive rewrites:
  4720 
  4721   make_keylist = AList.make
  4722   keyfilter = AList.find (op =)
  4723 
  4724 * eq_fst and eq_snd now take explicit equality parameter, thus
  4725   avoiding eqtypes. Naive rewrites:
  4726 
  4727     eq_fst = eq_fst (op =)
  4728     eq_snd = eq_snd (op =)
  4729 
  4730 * Removed deprecated apl and apr (rarely used).
  4731   Naive rewrites:
  4732 
  4733     apl (n, op) =>>= curry op n
  4734     apr (op, m) =>>= fn n => op (n, m)
  4735 
  4736 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4737 provides a reasonably efficient light-weight implementation of sets as
  4738 lists.
  4739 
  4740 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4741 few new operations; existing lookup and update are now curried to
  4742 follow natural argument order (for use with fold etc.);
  4743 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4744 
  4745 * Pure/General: output via the Isabelle channels of
  4746 writeln/warning/error etc. is now passed through Output.output, with a
  4747 hook for arbitrary transformations depending on the print_mode
  4748 (cf. Output.add_mode -- the first active mode that provides a output
  4749 function wins).  Already formatted output may be embedded into further
  4750 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4751 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4752 accommodate easy composition of diagnostic messages etc.  Programmers
  4753 rarely need to care about Output.output or Output.raw at all, with
  4754 some notable exceptions: Output.output is required when bypassing the
  4755 standard channels (writeln etc.), or in token translations to produce
  4756 properly formatted results; Output.raw is required when capturing
  4757 already output material that will eventually be presented to the user
  4758 a second time.  For the default print mode, both Output.output and
  4759 Output.raw have no effect.
  4760 
  4761 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4762 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4763 cumulative results are displayed at the end of a batch session.
  4764 
  4765 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4766 replaced by File.platform_path and File.shell_path (with appropriate
  4767 hooks).  This provides a clean interface for unusual systems where the
  4768 internal and external process view of file names are different.
  4769 
  4770 * Pure: more efficient orders for basic syntactic entities: added
  4771 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4772 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4773 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4774 orders now -- potential INCOMPATIBILITY for code that depends on a
  4775 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4776 Library.sort_strings on result).
  4777 
  4778 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4779 fold_types traverse types/terms from left to right, observing natural
  4780 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4781 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4782 
  4783 * Pure: name spaces have been refined, with significant changes of the
  4784 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4785 to extern(_table).  The plain name entry path is superceded by a
  4786 general 'naming' context, which also includes the 'policy' to produce
  4787 a fully qualified name and external accesses of a fully qualified
  4788 name; NameSpace.extend is superceded by context dependent
  4789 Sign.declare_name.  Several theory and proof context operations modify
  4790 the naming context.  Especially note Theory.restore_naming and
  4791 ProofContext.restore_naming to get back to a sane state; note that
  4792 Theory.add_path is no longer sufficient to recover from
  4793 Theory.absolute_path in particular.
  4794 
  4795 * Pure: new flags short_names (default false) and unique_names
  4796 (default true) for controlling output of qualified names.  If
  4797 short_names is set, names are printed unqualified.  If unique_names is
  4798 reset, the name prefix is reduced to the minimum required to achieve
  4799 the original result when interning again, even if there is an overlap
  4800 with earlier declarations.
  4801 
  4802 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4803 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4804 (useful for printing error messages).  INCOMPATIBILITY.
  4805 
  4806 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4807 Theory.theory are now identified, referring to the universal
  4808 Context.theory (see Pure/context.ML).  Actual signature and theory
  4809 content is managed as theory data.  The old code and interfaces were
  4810 spread over many files and structures; the new arrangement introduces
  4811 considerable INCOMPATIBILITY to gain more clarity:
  4812 
  4813   Context -- theory management operations (name, identity, inclusion,
  4814     parents, ancestors, merge, etc.), plus generic theory data;
  4815 
  4816   Sign -- logical signature and syntax operations (declaring consts,
  4817     types, etc.), plus certify/read for common entities;
  4818 
  4819   Theory -- logical theory operations (stating axioms, definitions,
  4820     oracles), plus a copy of logical signature operations (consts,
  4821     types, etc.); also a few basic management operations (Theory.copy,
  4822     Theory.merge, etc.)
  4823 
  4824 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4825 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4826 for convenience -- they merely return the theory.
  4827 
  4828 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4829 
  4830 * Pure: the Isar proof context type is already defined early in Pure
  4831 as Context.proof (note that ProofContext.context and Proof.context are
  4832 aliases, where the latter is the preferred name).  This enables other
  4833 Isabelle components to refer to that type even before Isar is present.
  4834 
  4835 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4836 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4837 any of these kinds.  For example, Sign.intern typeK is now
  4838 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4839 Theory.hide_types.  Also note that former
  4840 Theory.hide_classes/types/consts are now
  4841 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4842 internalize their arguments!  INCOMPATIBILITY.
  4843 
  4844 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4845 datatype thmref (with constructors Name and NameSelection) instead of
  4846 plain string -- INCOMPATIBILITY;
  4847 
  4848 * Pure: cases produced by proof methods specify options, where NONE
  4849 means to remove case bindings -- INCOMPATIBILITY in
  4850 (RAW_)METHOD_CASES.
  4851 
  4852 * Pure: the following operations retrieve axioms or theorems from a
  4853 theory node or theory hierarchy, respectively:
  4854 
  4855   Theory.axioms_of: theory -> (string * term) list
  4856   Theory.all_axioms_of: theory -> (string * term) list
  4857   PureThy.thms_of: theory -> (string * thm) list
  4858   PureThy.all_thms_of: theory -> (string * thm) list
  4859 
  4860 * Pure: print_tac now outputs the goal through the trace channel.
  4861 
  4862 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4863 Reference Toplevel.debug (default false) controls detailed printing
  4864 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4865 controls execution profiling -- set to 1 for time and 2 for space
  4866 (both increase the runtime).
  4867 
  4868 * Isar session: The initial use of ROOT.ML is now always timed,
  4869 i.e. the log will show the actual process times, in contrast to the
  4870 elapsed wall-clock time that the outer shell wrapper produces.
  4871 
  4872 * Simplifier: improved handling of bound variables (nameless
  4873 representation, avoid allocating new strings).  Simprocs that invoke
  4874 the Simplifier recursively should use Simplifier.inherit_bounds to
  4875 avoid local name clashes.  Failure to do so produces warnings
  4876 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4877 for further details.
  4878 
  4879 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4880 bindings for all theorems stored within a given theory; this may help
  4881 in porting non-Isar theories to Isar ones, while keeping ML proof
  4882 scripts for the time being.
  4883 
  4884 * ML operator HTML.with_charset specifies the charset begin used for
  4885 generated HTML files.  For example:
  4886 
  4887   HTML.with_charset "utf-8" use_thy "Hebrew";
  4888   HTML.with_charset "utf-8" use_thy "Chinese";
  4889 
  4890 
  4891 *** System ***
  4892 
  4893 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4894 isabelle, isatool etc.).
  4895 
  4896 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4897 isatool doc, isatool mkdir, display_drafts etc.).
  4898 
  4899 * isatool usedir: option -f allows specification of the ML file to be
  4900 used by Isabelle; default is ROOT.ML.
  4901 
  4902 * New isatool version outputs the version identifier of the Isabelle
  4903 distribution being used.
  4904 
  4905 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4906 (containing Boolean satisfiability problems) into Isabelle/HOL
  4907 theories.
  4908 
  4909 
  4910 
  4911 New in Isabelle2004 (April 2004)
  4912 --------------------------------
  4913 
  4914 *** General ***
  4915 
  4916 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4917   Replaces linorder.ML.
  4918 
  4919 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4920   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4921   (\<a>...\<z>), are now considered normal letters, and can therefore
  4922   be used anywhere where an ASCII letter (a...zA...Z) has until
  4923   now. COMPATIBILITY: This obviously changes the parsing of some
  4924   terms, especially where a symbol has been used as a binder, say
  4925   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4926   as an identifier.  Fix it by inserting a space around former
  4927   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4928   existing theory and ML files.
  4929 
  4930 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4931 
  4932 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4933   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4934   a normal (but invisible) letter. For multiple letter subscripts repeat
  4935   \<^isub> like this: x\<^isub>1\<^isub>2.
  4936 
  4937 * Pure: There are now sub-/superscripts that can span more than one
  4938   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4939   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4940   superscript. The new control characters are not identifier parts.
  4941 
  4942 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4943   content of "..." to the latex file instead of \isacntrl... . The "..."
  4944   may consist of any printable characters excluding the end bracket >.
  4945 
  4946 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4947   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4948   declare constants "final", which prevents their being given a definition
  4949   later.  It is useful for constants whose behaviour is fixed axiomatically
  4950   rather than definitionally, such as the meta-logic connectives.
  4951 
  4952 * Pure: 'instance' now handles general arities with general sorts
  4953   (i.e. intersections of classes),
  4954 
  4955 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4956   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4957   It can be changed to alter the colors/layout of generated pages.
  4958 
  4959 
  4960 *** Isar ***
  4961 
  4962 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4963   cut_tac, subgoal_tac and thin_tac:
  4964   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4965     locales are no longer forced to write Isar proof scripts.
  4966     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4967     emulations.
  4968   - INCOMPATIBILITY: names of variables to be instantiated may no
  4969     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4970     This is consistent with the instantiation attribute "where".
  4971 
  4972 * Attributes "where" and "of":
  4973   - Now take type variables of instantiated theorem into account when reading
  4974     the instantiation string.  This fixes a bug that caused instantiated
  4975     theorems to have too special types in some circumstances.
  4976   - "where" permits explicit instantiations of type variables.
  4977 
  4978 * Calculation commands "moreover" and "also" no longer interfere with
  4979   current facts ("this"), admitting arbitrary combinations with "then"
  4980   and derived forms.
  4981 
  4982 * Locales:
  4983   - Goal statements involving the context element "includes" no longer
  4984     generate theorems with internal delta predicates (those ending on
  4985     "_axioms") in the premise.
  4986     Resolve particular premise with <locale>.intro to obtain old form.
  4987   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4988     specification and "includes" elements in goal statement.
  4989   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4990     [intro?] and [elim?] (respectively) by default.
  4991   - Experimental command for instantiation of locales in proof contexts:
  4992         instantiate <label>[<attrs>]: <loc>
  4993     Instantiates locale <loc> and adds all its theorems to the current context
  4994     taking into account their attributes.  Label and attrs are optional
  4995     modifiers, like in theorem declarations.  If present, names of
  4996     instantiated theorems are qualified with <label>, and the attributes
  4997     <attrs> are applied after any attributes these theorems might have already.
  4998       If the locale has assumptions, a chained fact of the form
  4999     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5000     are derived.  The command does not support old-style locales declared
  5001     with "locale (open)".
  5002       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5003 
  5004 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5005   (Isar) contexts.
  5006 
  5007 
  5008 *** HOL ***
  5009 
  5010 * Proof import: new image HOL4 contains the imported library from
  5011   the HOL4 system with about 2500 theorems. It is imported by
  5012   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5013   can be used like any other Isabelle image.  See
  5014   HOL/Import/HOL/README for more information.
  5015 
  5016 * Simplifier:
  5017   - Much improved handling of linear and partial orders.
  5018     Reasoners for linear and partial orders are set up for type classes
  5019     "linorder" and "order" respectively, and are added to the default simpset
  5020     as solvers.  This means that the simplifier can build transitivity chains
  5021     to solve goals from the assumptions.
  5022   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5023     of blast or auto after simplification become unnecessary because the goal
  5024     is solved by simplification already.
  5025 
  5026 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5027     all proved in axiomatic type classes for semirings, rings and fields.
  5028 
  5029 * Numerics:
  5030   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5031     now formalized using the Ring_and_Field theory mentioned above.
  5032   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5033     than before, because now they are set up once in a generic manner.
  5034   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5035     Look for the general versions in Ring_and_Field (and Power if they concern
  5036     exponentiation).
  5037 
  5038 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5039 
  5040 * Records:
  5041   - Record types are now by default printed with their type abbreviation
  5042     instead of the list of all field types. This can be configured via
  5043     the reference "print_record_type_abbr".
  5044   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5045     (not enabled by default).
  5046   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5047     EX x. x = sel r to True (not enabled by default).
  5048   - Tactic "record_split_simp_tac" to split and simplify records added.
  5049 
  5050 * 'specification' command added, allowing for definition by
  5051   specification.  There is also an 'ax_specification' command that
  5052   introduces the new constants axiomatically.
  5053 
  5054 * arith(_tac) is now able to generate counterexamples for reals as well.
  5055 
  5056 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5057 
  5058 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5059   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5060 
  5061 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5062   matrix theory to linear programming.
  5063 
  5064 * Unions and Intersections:
  5065   The latex output syntax of UN and INT has been changed
  5066   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5067   i.e. the index formulae has become a subscript.
  5068   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5069 
  5070 * Unions and Intersections over Intervals:
  5071   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5072   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5073   like in normal math, and corresponding versions for < and for intersection.
  5074 
  5075 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5076   lexicographic dictonary ordering has been added as "lexord".
  5077 
  5078 * ML: the legacy theory structures Int and List have been removed. They had
  5079   conflicted with ML Basis Library structures having the same names.
  5080 
  5081 * 'refute' command added to search for (finite) countermodels.  Only works
  5082   for a fragment of HOL.  The installation of an external SAT solver is
  5083   highly recommended.  See "HOL/Refute.thy" for details.
  5084 
  5085 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5086   formulae under an assignment of free variables to random values.
  5087   In contrast to 'refute', it can deal with inductive datatypes,
  5088   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5089   for examples.
  5090 
  5091 
  5092 *** HOLCF ***
  5093 
  5094 * Streams now come with concatenation and are part of the HOLCF image
  5095 
  5096 
  5097 
  5098 New in Isabelle2003 (May 2003)
  5099 ------------------------------
  5100 
  5101 *** General ***
  5102 
  5103 * Provers/simplifier:
  5104 
  5105   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5106     Assumptions are now subject to complete mutual simplification,
  5107     not just from left to right. The simplifier now preserves
  5108     the order of assumptions.
  5109 
  5110     Potential INCOMPATIBILITY:
  5111 
  5112     -- simp sometimes diverges where the old version did
  5113        not, e.g. invoking simp on the goal
  5114 
  5115         [| P (f x); y = x; f x = f y |] ==> Q
  5116 
  5117        now gives rise to the infinite reduction sequence
  5118 
  5119         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5120 
  5121        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5122        kind of problem.
  5123 
  5124     -- Tactics combining classical reasoner and simplification (such as auto)
  5125        are also affected by this change, because many of them rely on
  5126        simp. They may sometimes diverge as well or yield a different numbers
  5127        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5128        in case of problems. Sometimes subsequent calls to the classical
  5129        reasoner will fail because a preceeding call to the simplifier too
  5130        eagerly simplified the goal, e.g. deleted redundant premises.
  5131 
  5132   - The simplifier trace now shows the names of the applied rewrite rules
  5133 
  5134   - You can limit the number of recursive invocations of the simplifier
  5135     during conditional rewriting (where the simplifie tries to solve the
  5136     conditions before applying the rewrite rule):
  5137     ML "simp_depth_limit := n"
  5138     where n is an integer. Thus you can force termination where previously
  5139     the simplifier would diverge.
  5140 
  5141   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5142 
  5143   - No longer aborts on failed congruence proof.  Instead, the
  5144     congruence is ignored.
  5145 
  5146 * Pure: New generic framework for extracting programs from constructive
  5147   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5148   as HOL/Extraction for some case studies.
  5149 
  5150 * Pure: The main goal of the proof state is no longer shown by default, only
  5151 the subgoals. This behaviour is controlled by a new flag.
  5152    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5153 (ML: Proof.show_main_goal).
  5154 
  5155 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5156 rules whose conclusion matches subgoal 1:
  5157       PG menu: Isabelle/Isar -> Show me -> matching rules
  5158 The rules are ordered by how closely they match the subgoal.
  5159 In particular, rules that solve a subgoal outright are displayed first
  5160 (or rather last, the way they are printed).
  5161 (ML: ProofGeneral.print_intros())
  5162 
  5163 * Pure: New flag trace_unify_fail causes unification to print
  5164 diagnostic information (PG: in trace buffer) when it fails. This is
  5165 useful for figuring out why single step proofs like rule, erule or
  5166 assumption failed.
  5167 
  5168 * Pure: Locale specifications now produce predicate definitions
  5169 according to the body of text (covering assumptions modulo local
  5170 definitions); predicate "loc_axioms" covers newly introduced text,
  5171 while "loc" is cumulative wrt. all included locale expressions; the
  5172 latter view is presented only on export into the global theory
  5173 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5174 on the old view without predicates;
  5175 
  5176 * Pure: predefined locales "var" and "struct" are useful for sharing
  5177 parameters (as in CASL, for example); just specify something like
  5178 ``var x + var y + struct M'' as import;
  5179 
  5180 * Pure: improved thms_containing: proper indexing of facts instead of
  5181 raw theorems; check validity of results wrt. current name space;
  5182 include local facts of proof configuration (also covers active
  5183 locales), cover fixed variables in index; may use "_" in term
  5184 specification; an optional limit for the number of printed facts may
  5185 be given (the default is 40);
  5186 
  5187 * Pure: disallow duplicate fact bindings within new-style theory files
  5188 (batch-mode only);
  5189 
  5190 * Provers: improved induct method: assumptions introduced by case
  5191 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5192 the goal statement); "foo" still refers to all facts collectively;
  5193 
  5194 * Provers: the function blast.overloaded has been removed: all constants
  5195 are regarded as potentially overloaded, which improves robustness in exchange
  5196 for slight decrease in efficiency;
  5197 
  5198 * Provers/linorder: New generic prover for transitivity reasoning over
  5199 linear orders.  Note: this prover is not efficient!
  5200 
  5201 * Isar: preview of problems to finish 'show' now produce an error
  5202 rather than just a warning (in interactive mode);
  5203 
  5204 
  5205 *** HOL ***
  5206 
  5207 * arith(_tac)
  5208 
  5209  - Produces a counter example if it cannot prove a goal.
  5210    Note that the counter example may be spurious if the goal is not a formula
  5211    of quantifier-free linear arithmetic.
  5212    In ProofGeneral the counter example appears in the trace buffer.
  5213 
  5214  - Knows about div k and mod k where k is a numeral of type nat or int.
  5215 
  5216  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5217    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5218    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5219 
  5220 * simp's arithmetic capabilities have been enhanced a bit: it now
  5221 takes ~= in premises into account (by performing a case split);
  5222 
  5223 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5224 are distributed over a sum of terms;
  5225 
  5226 * New tactic "trans_tac" and method "trans" instantiate
  5227 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5228 "<=", "<" and "=").
  5229 
  5230 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5231 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5232 
  5233 * 'typedef' command has new option "open" to suppress the set
  5234 definition;
  5235 
  5236 * functions Min and Max on finite sets have been introduced (theory
  5237 Finite_Set);
  5238 
  5239 * attribute [symmetric] now works for relations as well; it turns
  5240 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5241 
  5242 * induct over a !!-quantified statement (say !!x1..xn):
  5243   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5244 
  5245 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5246 %x. None. Warning: empty_def now refers to the previously hidden definition
  5247 of the empty set.
  5248 
  5249 * Algebra: formalization of classical algebra.  Intended as base for
  5250 any algebraic development in Isabelle.  Currently covers group theory
  5251 (up to Sylow's theorem) and ring theory (Universal Property of
  5252 Univariate Polynomials).  Contributions welcome;
  5253 
  5254 * GroupTheory: deleted, since its material has been moved to Algebra;
  5255 
  5256 * Complex: new directory of the complex numbers with numeric constants,
  5257 nonstandard complex numbers, and some complex analysis, standard and
  5258 nonstandard (Jacques Fleuriot);
  5259 
  5260 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5261 
  5262 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5263 Fleuriot);
  5264 
  5265 * Real/HahnBanach: updated and adapted to locales;
  5266 
  5267 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5268 Gray and Kramer);
  5269 
  5270 * UNITY: added the Meier-Sanders theory of progress sets;
  5271 
  5272 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5273 as abstract algorithms, instantiated to the JVM;
  5274 
  5275 * Bali: Java source language formalization. Type system, operational
  5276 semantics, axiomatic semantics. Supported language features:
  5277 classes, interfaces, objects,virtual methods, static methods,
  5278 static/instance fields, arrays, access modifiers, definite
  5279 assignment, exceptions.
  5280 
  5281 
  5282 *** ZF ***
  5283 
  5284 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5285 universe, etc.);
  5286 
  5287 * Main ZF: virtually all theories converted to new-style format;
  5288 
  5289 
  5290 *** ML ***
  5291 
  5292 * Pure: Tactic.prove provides sane interface for internal proofs;
  5293 omits the infamous "standard" operation, so this is more appropriate
  5294 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5295 
  5296 * Pure: improved error reporting of simprocs;
  5297 
  5298 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5299 up simprocs;
  5300 
  5301 
  5302 *** Document preparation ***
  5303 
  5304 * uses \par instead of \\ for line breaks in theory text. This may
  5305 shift some page breaks in large documents. To get the old behaviour
  5306 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5307 
  5308 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5309 other packages
  5310 
  5311 * \<euro> now needs package babel/greek instead of marvosym (which
  5312 broke \Rightarrow)
  5313 
  5314 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5315 textcomp package)
  5316 
  5317 
  5318 
  5319 New in Isabelle2002 (March 2002)
  5320 --------------------------------
  5321 
  5322 *** Document preparation ***
  5323 
  5324 * greatly simplified document preparation setup, including more
  5325 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5326 instructive isatool mkdir; users should basically be able to get
  5327 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5328 users may run a separate document processing stage manually like this:
  5329 "isatool usedir -D output HOL Test && isatool document Test/output";
  5330 
  5331 * theory dependency graph may now be incorporated into documents;
  5332 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5333 with \includegraphics of LaTeX;
  5334 
  5335 * proper spacing of consecutive markup elements, especially text
  5336 blocks after section headings;
  5337 
  5338 * support bold style (for single symbols only), input syntax is like
  5339 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5340 
  5341 * \<bullet> is now output as bold \cdot by default, which looks much
  5342 better in printed text;
  5343 
  5344 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5345 note that these symbols are currently unavailable in Proof General /
  5346 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5347 
  5348 * isatool latex no longer depends on changed TEXINPUTS, instead
  5349 isatool document copies the Isabelle style files to the target
  5350 location;
  5351 
  5352 
  5353 *** Isar ***
  5354 
  5355 * Pure/Provers: improved proof by cases and induction;
  5356   - 'case' command admits impromptu naming of parameters (such as
  5357     "case (Suc n)");
  5358   - 'induct' method divinates rule instantiation from the inductive
  5359     claim; no longer requires excessive ?P bindings for proper
  5360     instantiation of cases;
  5361   - 'induct' method properly enumerates all possibilities of set/type
  5362     rules; as a consequence facts may be also passed through *type*
  5363     rules without further ado;
  5364   - 'induct' method now derives symbolic cases from the *rulified*
  5365     rule (before it used to rulify cases stemming from the internal
  5366     atomized version); this means that the context of a non-atomic
  5367     statement becomes is included in the hypothesis, avoiding the
  5368     slightly cumbersome show "PROP ?case" form;
  5369   - 'induct' may now use elim-style induction rules without chaining
  5370     facts, using ``missing'' premises from the goal state; this allows
  5371     rules stemming from inductive sets to be applied in unstructured
  5372     scripts, while still benefitting from proper handling of non-atomic
  5373     statements; NB: major inductive premises need to be put first, all
  5374     the rest of the goal is passed through the induction;
  5375   - 'induct' proper support for mutual induction involving non-atomic
  5376     rule statements (uses the new concept of simultaneous goals, see
  5377     below);
  5378   - append all possible rule selections, but only use the first
  5379     success (no backtracking);
  5380   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5381   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5382   - added 'print_induct_rules' (covered by help item in recent Proof
  5383     General versions);
  5384   - moved induct/cases attributes to Pure, methods to Provers;
  5385   - generic method setup instantiated for FOL and HOL;
  5386 
  5387 * Pure: support multiple simultaneous goal statements, for example
  5388 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5389 meta-level mechanism, this acts as if several individual goals had
  5390 been stated separately; in particular common proof methods need to be
  5391 repeated in order to cover all claims; note that a single elimination
  5392 step is *not* sufficient to establish the two conjunctions, so this
  5393 fails:
  5394 
  5395   assume "A & B" then have A and B ..   (*".." fails*)
  5396 
  5397 better use "obtain" in situations as above; alternative refer to
  5398 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5399 
  5400 * Pure: proper integration with ``locales''; unlike the original
  5401 version by Florian Kammller, Isar locales package high-level proof
  5402 contexts rather than raw logical ones (e.g. we admit to include
  5403 attributes everywhere); operations on locales include merge and
  5404 rename; support for implicit arguments (``structures''); simultaneous
  5405 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5406 some examples;
  5407 
  5408 * Pure: the following commands have been ``localized'', supporting a
  5409 target locale specification "(in name)": 'lemma', 'theorem',
  5410 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5411 stored both within the locale and at the theory level (exported and
  5412 qualified by the locale name);
  5413 
  5414 * Pure: theory goals may now be specified in ``long'' form, with
  5415 ad-hoc contexts consisting of arbitrary locale elements. for example
  5416 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5417 definitions may be given, too); the result is a meta-level rule with
  5418 the context elements being discharged in the obvious way;
  5419 
  5420 * Pure: new proof command 'using' allows to augment currently used
  5421 facts after a goal statement ('using' is syntactically analogous to
  5422 'apply', but acts on the goal's facts only); this allows chained facts
  5423 to be separated into parts given before and after a claim, as in
  5424 ``from a and b have C using d and e <proof>'';
  5425 
  5426 * Pure: renamed "antecedent" case to "rule_context";
  5427 
  5428 * Pure: new 'judgment' command records explicit information about the
  5429 object-logic embedding (used by several tools internally); no longer
  5430 use hard-wired "Trueprop";
  5431 
  5432 * Pure: added 'corollary' command;
  5433 
  5434 * Pure: fixed 'token_translation' command;
  5435 
  5436 * Pure: removed obsolete 'exported' attribute;
  5437 
  5438 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5439 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5440 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5441 
  5442 * Pure: method 'atomize' presents local goal premises as object-level
  5443 statements (atomic meta-level propositions); setup controlled via
  5444 rewrite rules declarations of 'atomize' attribute; example
  5445 application: 'induct' method with proper rule statements in improper
  5446 proof *scripts*;
  5447 
  5448 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5449 now consider the syntactic context of assumptions, giving a better
  5450 chance to get type-inference of the arguments right (this is
  5451 especially important for locales);
  5452 
  5453 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5454 mode;
  5455 
  5456 * Pure/obtain: the formal conclusion "thesis", being marked as
  5457 ``internal'', may no longer be reference directly in the text;
  5458 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5459 situations;
  5460 
  5461 * Pure: generic 'sym' attribute which declares a rule both as pure
  5462 'elim?' and for the 'symmetric' operation;
  5463 
  5464 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5465 text; the fixed correlation with particular command syntax has been
  5466 discontinued;
  5467 
  5468 * Pure: new method 'rules' is particularly well-suited for proof
  5469 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5470 but often produces more compact proof terms with less detours;
  5471 
  5472 * Pure/Provers/classical: simplified integration with pure rule
  5473 attributes and methods; the classical "intro?/elim?/dest?"
  5474 declarations coincide with the pure ones; the "rule" method no longer
  5475 includes classically swapped intros; "intro" and "elim" methods no
  5476 longer pick rules from the context; also got rid of ML declarations
  5477 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5478 INCOMPATIBILITY;
  5479 
  5480 * Provers/classical: attribute 'swapped' produces classical inversions
  5481 of introduction rules;
  5482 
  5483 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5484 rules instead of full simplifier context; 'iff' attribute handles
  5485 conditional rules;
  5486 
  5487 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5488 
  5489 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5490 "(permissive)" option to recover old behavior;
  5491 
  5492 * HOL: 'inductive' no longer features separate (collective) attributes
  5493 for 'intros' (was found too confusing);
  5494 
  5495 * HOL: properly declared induction rules less_induct and
  5496 wf_induct_rule;
  5497 
  5498 
  5499 *** HOL ***
  5500 
  5501 * HOL: moved over to sane numeral syntax; the new policy is as
  5502 follows:
  5503 
  5504   - 0 and 1 are polymorphic constants, which are defined on any
  5505   numeric type (nat, int, real etc.);
  5506 
  5507   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5508   binary representation internally;
  5509 
  5510   - type nat has special constructor Suc, and generally prefers Suc 0
  5511   over 1::nat and Suc (Suc 0) over 2::nat;
  5512 
  5513 This change may cause significant problems of INCOMPATIBILITY; here
  5514 are some hints on converting existing sources:
  5515 
  5516   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5517   entities, so expressions involving "-" (unary or binary minus) need
  5518   to be spaced properly;
  5519 
  5520   - existing occurrences of "1" may need to be constraint "1::nat" or
  5521   even replaced by Suc 0; similar for old "2";
  5522 
  5523   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5524 
  5525   - remove all special provisions on numerals in proofs;
  5526 
  5527 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5528 representation (depends on bin_arith_simps in the default context);
  5529 
  5530 * HOL: symbolic syntax for x^2 (numeral 2);
  5531 
  5532 * HOL: the class of all HOL types is now called "type" rather than
  5533 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5534 in axclass/classes, instance/arities, and (usually rare) occurrences
  5535 in typings (of consts etc.); internally the class is called
  5536 "HOL.type", ML programs should refer to HOLogic.typeS;
  5537 
  5538 * HOL/record package improvements:
  5539   - new derived operations "fields" to build a partial record section,
  5540     "extend" to promote a fixed record to a record scheme, and
  5541     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5542     declared as simp by default;
  5543   - shared operations ("more", "fields", etc.) now need to be always
  5544     qualified) --- potential INCOMPATIBILITY;
  5545   - removed "make_scheme" operations (use "make" with "extend") --
  5546     INCOMPATIBILITY;
  5547   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5548   - provides cases/induct rules for use with corresponding Isar
  5549     methods (for concrete records, record schemes, concrete more
  5550     parts, and schematic more parts -- in that order);
  5551   - internal definitions directly based on a light-weight abstract
  5552     theory of product types over typedef rather than datatype;
  5553 
  5554 * HOL: generic code generator for generating executable ML code from
  5555 specifications; specific support for HOL constructs such as inductive
  5556 datatypes and sets, as well as recursive functions; can be invoked
  5557 via 'generate_code' theory section;
  5558 
  5559 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5560 
  5561 * HOL: consolidated and renamed several theories.  In particular:
  5562         Ord.thy has been absorbed into HOL.thy
  5563         String.thy has been absorbed into List.thy
  5564 
  5565 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5566 (beware of argument permutation!);
  5567 
  5568 * HOL: linorder_less_split superseded by linorder_cases;
  5569 
  5570 * HOL/List: "nodups" renamed to "distinct";
  5571 
  5572 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5573 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5574   - Ex_def has changed, now need to use some_eq_ex
  5575 
  5576 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5577 in this (rare) case use:
  5578 
  5579   delSWrapper "split_all_tac"
  5580   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5581 
  5582 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5583 MAY FAIL;
  5584 
  5585 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5586 Isabelle's type classes, ^ on functions and relations has too general
  5587 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5588 necessary to attach explicit type constraints;
  5589 
  5590 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5591 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5592 renamed accordingly (eg "compI" -> "rel_compI").
  5593 
  5594 * HOL: syntax translations now work properly with numerals and records
  5595 expressions;
  5596 
  5597 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5598 of "lam" -- INCOMPATIBILITY;
  5599 
  5600 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5601 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5602 renamed "Product_Type.unit";
  5603 
  5604 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5605 
  5606 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5607 the "cases" method);
  5608 
  5609 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5610 Florian Kammller);
  5611 
  5612 * HOL/IMP: updated and converted to new-style theory format; several
  5613 parts turned into readable document, with proper Isar proof texts and
  5614 some explanations (by Gerwin Klein);
  5615 
  5616 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5617 
  5618 * HOL-Hyperreal is now a logic image;
  5619 
  5620 
  5621 *** HOLCF ***
  5622 
  5623 * Isar: consts/constdefs supports mixfix syntax for continuous
  5624 operations;
  5625 
  5626 * Isar: domain package adapted to new-style theory format, e.g. see
  5627 HOLCF/ex/Dnat.thy;
  5628 
  5629 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5630 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5631 lift.induct_tac, always use UU instead of Undef;
  5632 
  5633 * HOLCF/IMP: updated and converted to new-style theory;
  5634 
  5635 
  5636 *** ZF ***
  5637 
  5638 * Isar: proper integration of logic-specific tools and packages,
  5639 including theory commands '(co)inductive', '(co)datatype',
  5640 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5641 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5642 
  5643 * theory Main no longer includes AC; for the Axiom of Choice, base
  5644 your theory on Main_ZFC;
  5645 
  5646 * the integer library now covers quotients and remainders, with many
  5647 laws relating division to addition, multiplication, etc.;
  5648 
  5649 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5650 typeless version of the formalism;
  5651 
  5652 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5653 format;
  5654 
  5655 * ZF/Induct: new directory for examples of inductive definitions,
  5656 including theory Multiset for multiset orderings; converted to
  5657 new-style theory format;
  5658 
  5659 * ZF: many new theorems about lists, ordinals, etc.;
  5660 
  5661 
  5662 *** General ***
  5663 
  5664 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5665 variable proof controls level of detail: 0 = no proofs (only oracle
  5666 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5667 also ref manual for further ML interfaces;
  5668 
  5669 * Pure/axclass: removed obsolete ML interface
  5670 goal_subclass/goal_arity;
  5671 
  5672 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5673 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5674 separate tokens, so expressions involving minus need to be spaced
  5675 properly;
  5676 
  5677 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5678 rather than "infixl" or "infixr";
  5679 
  5680 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5681 sort constraint specifications in type inference; e.g. "x::_::foo"
  5682 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5683 type variable);
  5684 
  5685 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5686 control output of nested => (types); the default behavior is
  5687 "type_brackets";
  5688 
  5689 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5690 tokens into AST constants;
  5691 
  5692 * Pure/syntax: prefer later declarations of translations and print
  5693 translation functions; potential INCOMPATIBILITY: need to reverse
  5694 multiple declarations for same syntax element constant;
  5695 
  5696 * Pure/show_hyps reset by default (in accordance to existing Isar
  5697 practice);
  5698 
  5699 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5700 addSafter;
  5701 
  5702 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5703 as well;
  5704 
  5705 * system: tested support for MacOS X; should be able to get Isabelle +
  5706 Proof General to work in a plain Terminal after installing Poly/ML
  5707 (e.g. from the Isabelle distribution area) and GNU bash alone
  5708 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5709 support requires further installations, e.g. from
  5710 http://fink.sourceforge.net/);
  5711 
  5712 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5713 
  5714 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5715 of 40 MB), cf. ML_OPTIONS;
  5716 
  5717 * system: Proof General keywords specification is now part of the
  5718 Isabelle distribution (see etc/isar-keywords.el);
  5719 
  5720 * system: support for persistent Proof General sessions (refrain from
  5721 outdating all loaded theories on startup); user may create writable
  5722 logic images like this: ``isabelle -q HOL Test'';
  5723 
  5724 * system: smart selection of Isabelle process versus Isabelle
  5725 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5726 run both "isabelle" and "Isabelle" even if file names are badly
  5727 damaged (executable inspects the case of the first letter of its own
  5728 name); added separate "isabelle-process" and "isabelle-interface";
  5729 
  5730 * system: refrain from any attempt at filtering input streams; no
  5731 longer support ``8bit'' encoding of old isabelle font, instead proper
  5732 iso-latin characters may now be used; the related isatools
  5733 "symbolinput" and "nonascii" have disappeared as well;
  5734 
  5735 * system: removed old "xterm" interface (the print modes "xterm" and
  5736 "xterm_color" are still available for direct use in a suitable
  5737 terminal);
  5738 
  5739 
  5740 
  5741 New in Isabelle99-2 (February 2001)
  5742 -----------------------------------
  5743 
  5744 *** Overview of INCOMPATIBILITIES ***
  5745 
  5746 * HOL: please note that theories in the Library and elsewhere often use the
  5747 new-style (Isar) format; to refer to their theorems in an ML script you must
  5748 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5749 
  5750 * HOL: inductive package no longer splits induction rule aggressively,
  5751 but only as far as specified by the introductions given; the old
  5752 format may be recovered via ML function complete_split_rule or attribute
  5753 'split_rule (complete)';
  5754 
  5755 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5756 gfp_Tarski to gfp_unfold;
  5757 
  5758 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5759 
  5760 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5761 relation); infix "^^" has been renamed "``"; infix "``" has been
  5762 renamed "`"; "univalent" has been renamed "single_valued";
  5763 
  5764 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5765 operation;
  5766 
  5767 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5768 
  5769 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5770 
  5771 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5772 consequence, it is no longer monotonic wrt. the local goal context
  5773 (which is now passed through the inductive cases);
  5774 
  5775 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5776 \<gg> to \<ggreater>;
  5777 
  5778 
  5779 *** Document preparation ***
  5780 
  5781 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5782 available: are "it" for near math-mode best-style output, "sl" for
  5783 slanted text style, and "tt" for plain type-writer; if no
  5784 \isabellestyle command is given, output is according to slanted
  5785 type-writer);
  5786 
  5787 * support sub/super scripts (for single symbols only), input syntax is
  5788 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5789 
  5790 * some more standard symbols; see Appendix A of the system manual for
  5791 the complete list of symbols defined in isabellesym.sty;
  5792 
  5793 * improved isabelle style files; more abstract symbol implementation
  5794 (should now use \isamath{...} and \isatext{...} in custom symbol
  5795 definitions);
  5796 
  5797 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5798 state; Note that presentation of goal states does not conform to
  5799 actual human-readable proof documents.  Please do not include goal
  5800 states into document output unless you really know what you are doing!
  5801 
  5802 * proper indentation of antiquoted output with proportional LaTeX
  5803 fonts;
  5804 
  5805 * no_document ML operator temporarily disables LaTeX document
  5806 generation;
  5807 
  5808 * isatool unsymbolize tunes sources for plain ASCII communication;
  5809 
  5810 
  5811 *** Isar ***
  5812 
  5813 * Pure: Isar now suffers initial goal statements to contain unbound
  5814 schematic variables (this does not conform to actual readable proof
  5815 documents, due to unpredictable outcome and non-compositional proof
  5816 checking); users who know what they are doing may use schematic goals
  5817 for Prolog-style synthesis of proven results;
  5818 
  5819 * Pure: assumption method (an implicit finishing) now handles actual
  5820 rules as well;
  5821 
  5822 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5823 initial goal, declare "that" only as Pure intro (only for single
  5824 steps); the "that" rule assumption may now be involved in implicit
  5825 finishing, thus ".." becomes a feasible for trivial obtains;
  5826 
  5827 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5828 instance proofs may be performed by "..";
  5829 
  5830 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5831 statements as well;
  5832 
  5833 * Pure: more robust selection of calculational rules;
  5834 
  5835 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5836 rule (as well as the assumption rule);
  5837 
  5838 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5839 lemmas, using the graph browser tool;
  5840 
  5841 * Pure: predict failure of "show" in interactive mode;
  5842 
  5843 * Pure: 'thms_containing' now takes actual terms as arguments;
  5844 
  5845 * HOL: improved method 'induct' --- now handles non-atomic goals
  5846 (potential INCOMPATIBILITY); tuned error handling;
  5847 
  5848 * HOL: cases and induct rules now provide explicit hints about the
  5849 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5850 any remaining facts are inserted into the goal verbatim;
  5851 
  5852 * HOL: local contexts (aka cases) may now contain term bindings as
  5853 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5854 the result to be shown in each case;
  5855 
  5856 * HOL: added 'recdef_tc' command;
  5857 
  5858 * isatool convert assists in eliminating legacy ML scripts;
  5859 
  5860 
  5861 *** HOL ***
  5862 
  5863 * HOL/Library: a collection of generic theories to be used together
  5864 with main HOL; the theory loader path already includes this directory
  5865 by default; the following existing theories have been moved here:
  5866 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5867 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5868 
  5869 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5870 modelling and verification task performed in Isabelle/HOL +
  5871 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5872 
  5873 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5874 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5875 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5876 'domain', this makes the theory consistent with mathematical
  5877 literature;
  5878 
  5879 * HOL basics: added overloaded operations "inverse" and "divide"
  5880 (infix "/"), syntax for generic "abs" operation, generic summation
  5881 operator \<Sum>;
  5882 
  5883 * HOL/typedef: simplified package, provide more useful rules (see also
  5884 HOL/subset.thy);
  5885 
  5886 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5887 now expressed as a proper nested rule (old-style tactic scripts may
  5888 require atomize_strip_tac to cope with non-atomic premises);
  5889 
  5890 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5891 to "split_conv" (old name still available for compatibility);
  5892 
  5893 * HOL: improved concrete syntax for strings (e.g. allows translation
  5894 rules with string literals);
  5895 
  5896 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5897  and Fleuriot's mechanization of analysis, including the transcendental
  5898  functions for the reals;
  5899 
  5900 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5901 
  5902 
  5903 *** CTT ***
  5904 
  5905 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5906 "lam" is displayed as TWO lambda-symbols
  5907 
  5908 * CTT: theory Main now available, containing everything (that is, Bool
  5909 and Arith);
  5910 
  5911 
  5912 *** General ***
  5913 
  5914 * Pure: the Simplifier has been implemented properly as a derived rule
  5915 outside of the actual kernel (at last!); the overall performance
  5916 penalty in practical applications is about 50%, while reliability of
  5917 the Isabelle inference kernel has been greatly improved;
  5918 
  5919 * print modes "brackets" and "no_brackets" control output of nested =>
  5920 (types) and ==> (props); the default behaviour is "brackets";
  5921 
  5922 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5923 as assumptions as well;
  5924 
  5925 * system: support Poly/ML 4.0;
  5926 
  5927 * system: isatool install handles KDE version 1 or 2;
  5928 
  5929 
  5930 
  5931 New in Isabelle99-1 (October 2000)
  5932 ----------------------------------
  5933 
  5934 *** Overview of INCOMPATIBILITIES ***
  5935 
  5936 * HOL: simplification of natural numbers is much changed; to partly
  5937 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5938 issue the following ML commands:
  5939 
  5940   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5941   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5942 
  5943 * HOL: simplification no longer dives into case-expressions; this is
  5944 controlled by "t.weak_case_cong" for each datatype t;
  5945 
  5946 * HOL: nat_less_induct renamed to less_induct;
  5947 
  5948 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5949 fixsome to patch .thy and .ML sources automatically;
  5950 
  5951   select_equality  -> some_equality
  5952   select_eq_Ex     -> some_eq_ex
  5953   selectI2EX       -> someI2_ex
  5954   selectI2         -> someI2
  5955   selectI          -> someI
  5956   select1_equality -> some1_equality
  5957   Eps_sym_eq       -> some_sym_eq_trivial
  5958   Eps_eq           -> some_eq_trivial
  5959 
  5960 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5961 
  5962 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5963 instead);
  5964 
  5965 * HOL: the recursion equations generated by 'recdef' are now called
  5966 f.simps instead of f.rules;
  5967 
  5968 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5969 
  5970 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5971 sometimes be needed;
  5972 
  5973 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5974 
  5975 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5976 
  5977 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5978 product is now "<*>" instead of "Times"; the lexicographic product is
  5979 now "<*lex*>" instead of "**";
  5980 
  5981 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5982 of main HOL, but was unused); better use HOL's datatype package;
  5983 
  5984 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5985 the old syntax may be recovered as follows:
  5986 
  5987   syntax (symbols)
  5988     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5989       (infixl "\\<oplus>" 100)
  5990 
  5991 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5992 
  5993 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5994 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5995 internally;
  5996 
  5997 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5998 changed from A/r to A//r;
  5999 
  6000 * ZF: new treatment of arithmetic (nat & int) may break some old
  6001 proofs;
  6002 
  6003 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6004 rulify -> rule_format, elimify -> elim_format, ...);
  6005 
  6006 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6007 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6008 should have to change intro!! to intro? only); replaced "delrule" by
  6009 "rule del";
  6010 
  6011 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6012 
  6013 * Provers: strengthened force_tac by using new first_best_tac;
  6014 
  6015 * LaTeX document preparation: several changes of isabelle.sty (see
  6016 lib/texinputs);
  6017 
  6018 
  6019 *** Document preparation ***
  6020 
  6021 * formal comments (text blocks etc.) in new-style theories may now
  6022 contain antiquotations of thm/prop/term/typ/text to be presented
  6023 according to latex print mode; concrete syntax is like this:
  6024 @{term[show_types] "f(x) = a + x"};
  6025 
  6026 * isatool mkdir provides easy setup of Isabelle session directories,
  6027 including proper document sources;
  6028 
  6029 * generated LaTeX sources are now deleted after successful run
  6030 (isatool document -c); may retain a copy somewhere else via -D option
  6031 of isatool usedir;
  6032 
  6033 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6034 style files, achieving self-contained LaTeX sources and simplifying
  6035 LaTeX debugging;
  6036 
  6037 * old-style theories now produce (crude) LaTeX output as well;
  6038 
  6039 * browser info session directories are now self-contained (may be put
  6040 on WWW server seperately); improved graphs of nested sessions; removed
  6041 graph for 'all sessions';
  6042 
  6043 * several improvements in isabelle style files; \isabellestyle{it}
  6044 produces fake math mode output; \isamarkupheader is now \section by
  6045 default; see lib/texinputs/isabelle.sty etc.;
  6046 
  6047 
  6048 *** Isar ***
  6049 
  6050 * Isar/Pure: local results and corresponding term bindings are now
  6051 subject to Hindley-Milner polymorphism (similar to ML); this
  6052 accommodates incremental type-inference very nicely;
  6053 
  6054 * Isar/Pure: new derived language element 'obtain' supports
  6055 generalized existence reasoning;
  6056 
  6057 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6058 support accumulation of results, without applying any rules yet;
  6059 useful to collect intermediate results without explicit name
  6060 references, and for use with transitivity rules with more than 2
  6061 premises;
  6062 
  6063 * Isar/Pure: scalable support for case-analysis type proofs: new
  6064 'case' language element refers to local contexts symbolically, as
  6065 produced by certain proof methods; internally, case names are attached
  6066 to theorems as "tags";
  6067 
  6068 * Isar/Pure: theory command 'hide' removes declarations from
  6069 class/type/const name spaces;
  6070 
  6071 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6072 indicate potential overloading;
  6073 
  6074 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6075 
  6076 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6077 "{a,b,c}" instead of {a,b,c};
  6078 
  6079 * Isar/Pure now provides its own version of intro/elim/dest
  6080 attributes; useful for building new logics, but beware of confusion
  6081 with the version in Provers/classical;
  6082 
  6083 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6084 case name 'antecedent';
  6085 
  6086 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6087 to the current context is now done automatically);
  6088 
  6089 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6090 for definining proof methods in ML;
  6091 
  6092 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6093 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6094 most cases, one should have to change intro!! to intro? only);
  6095 replaced "delrule" by "rule del";
  6096 
  6097 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6098 'symmetric' attribute (the latter supercedes [RS sym]);
  6099 
  6100 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6101 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6102 well (including splits);
  6103 
  6104 * Isar/Provers: Simplifier and Classical methods now support all kind
  6105 of modifiers used in the past, including 'cong', 'iff', etc.
  6106 
  6107 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6108 of Simplifier and Classical reasoner);
  6109 
  6110 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6111 now support named cases; major packages (inductive, datatype, primrec,
  6112 recdef) support case names and properly name parameters;
  6113 
  6114 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6115 monotonicity conditions are extracted to be proven at end of
  6116 calculations;
  6117 
  6118 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6119 method anyway;
  6120 
  6121 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6122 split_if split_if_asm; datatype package provides theorems foo.splits =
  6123 foo.split foo.split_asm for each datatype;
  6124 
  6125 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6126 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6127 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6128 use "(cases (simplified))" method in proper proof texts);
  6129 
  6130 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6131 
  6132 * Isar: names of theorems etc. may be natural numbers as well;
  6133 
  6134 * Isar: 'pr' command: optional arguments for goals_limit and
  6135 ProofContext.prems_limit; no longer prints theory contexts, but only
  6136 proof states;
  6137 
  6138 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6139 additional print modes to be specified; e.g. "pr(latex)" will print
  6140 proof state according to the Isabelle LaTeX style;
  6141 
  6142 * Isar: improved support for emulating tactic scripts, including proof
  6143 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6144 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6145 (for HOL datatypes);
  6146 
  6147 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6148 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6149 'proof method scripts' have to be in depth-first order;
  6150 
  6151 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6152 
  6153 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6154 should instead use individual commands for printing items
  6155 (print_commands, print_methods etc.);
  6156 
  6157 * Isar: added 'nothing' --- the empty list of theorems;
  6158 
  6159 
  6160 *** HOL ***
  6161 
  6162 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6163 corresponding virtual machine and a specification of its bytecode
  6164 verifier and a lightweight bytecode verifier, including proofs of
  6165 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6166 Cornelia Pusch (see also the homepage of project Bali at
  6167 http://isabelle.in.tum.de/Bali/);
  6168 
  6169 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6170 Clemens Ballarin;
  6171 
  6172 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6173 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6174 Rasmussen;
  6175 
  6176 * HOL/Lattice: fundamental concepts of lattice theory and order
  6177 structures, including duals, properties of bounds versus algebraic
  6178 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6179 Theorem for complete lattices etc.; may also serve as a demonstration
  6180 for abstract algebraic reasoning using axiomatic type classes, and
  6181 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6182 
  6183 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6184 von Oheimb;
  6185 
  6186 * HOL/IMPP: extension of IMP with local variables and mutually
  6187 recursive procedures, by David von Oheimb;
  6188 
  6189 * HOL/Lambda: converted into new-style theory and document;
  6190 
  6191 * HOL/ex/Multiquote: example of multiple nested quotations and
  6192 anti-quotations -- basically a generalized version of de-Bruijn
  6193 representation; very useful in avoiding lifting of operations;
  6194 
  6195 * HOL/record: added general record equality rule to simpset; fixed
  6196 select-update simplification procedure to handle extended records as
  6197 well; admit "r" as field name;
  6198 
  6199 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6200 other numeric types and also as the identity of groups, rings, etc.;
  6201 
  6202 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6203 Types nat and int belong to this axclass;
  6204 
  6205 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6206    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6207    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6208   two terms #m*u and #n*u are replaced by #(m+n)*u
  6209     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6210   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6211     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6212 
  6213 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6214 powerful prover for predicate logic but knows nothing of clasets; see
  6215 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6216 
  6217 * HOL: new version of "case_tac" subsumes both boolean case split and
  6218 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6219 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6220 
  6221 * HOL: simplification no longer dives into case-expressions: only the
  6222 selector expression is simplified, but not the remaining arms; to
  6223 enable full simplification of case-expressions for datatype t, you may
  6224 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6225 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6226 
  6227 * HOL/recdef: the recursion equations generated by 'recdef' for
  6228 function 'f' are now called f.simps instead of f.rules; if all
  6229 termination conditions are proved automatically, these simplification
  6230 rules are added to the simpset, as in primrec; rules may be named
  6231 individually as well, resulting in a separate list of theorems for
  6232 each equation;