NEWS
author haftmann
Fri Aug 27 13:32:05 2010 +0200 (2010-08-27)
changeset 38809 7dc73a208722
parent 38795 848be46708dc
child 38797 abe92b33ac9f
child 38814 4d575fbfc920
permissions -rw-r--r--
proper namespace administration for hierarchical modules
     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 
    27 *** Pure ***
    28 
    29 * Interpretation command 'interpret' accepts a list of equations like
    30 'interpretation' does.
    31 
    32 * Diagnostic command 'print_interps' prints interpretations in proofs
    33 in addition to interpretations in theories.
    34 
    35 * Discontinued obsolete 'global' and 'local' commands to manipulate
    36 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    37 Sign.root_path and Sign.local_path may be applied directly where this
    38 feature is still required for historical reasons.
    39 
    40 
    41 *** HOL ***
    42 
    43 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    44 
    45 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
    46 canonical names for instance definitions for functions; various improvements.
    47 INCOMPATIBILITY.
    48 
    49 * Records: logical foundation type for records do not carry a '_type' suffix
    50 any longer.  INCOMPATIBILITY.
    51 
    52 * Code generation for records: more idiomatic representation of record types.
    53 Warning: records are not covered by ancient SML code generation any longer.
    54 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
    55 helps to succeed then:
    56 
    57   record 'a foo = ...
    58   ...
    59   rep_datatype foo_ext ...
    60 
    61 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
    62 INCOMPATIBILITY.
    63 
    64 * Quickcheck in locales considers interpretations of that locale for
    65 counter example search.
    66 
    67 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
    68 in Library/State_Monad has been changed to avoid ambiguities.
    69 INCOMPATIBILITY.
    70 
    71 * Code generator: export_code without explicit file declaration prints
    72 to standard output.  INCOMPATIBILITY.
    73 
    74 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
    75 respectively.  INCOMPATIBILITY.
    76 
    77 * Constant "split" has been merged with constant "prod_case";  names
    78 of ML functions, facts etc. involving split have been retained so far,
    79 though.  INCOMPATIBILITY.
    80 
    81 * Dropped old infix syntax "mem" for List.member;  use "in set"
    82 instead.  INCOMPATIBILITY.
    83 
    84 * Refactoring of code-generation specific operations in List.thy
    85 
    86   constants
    87     null ~> List.null
    88 
    89   facts
    90     mem_iff ~> member_def
    91     null_empty ~> null_def
    92 
    93 INCOMPATIBILITY.  Note that these were not suppossed to be used
    94 regularly unless for striking reasons;  their main purpose was code
    95 generation.
    96 
    97 * Some previously unqualified names have been qualified:
    98 
    99   types
   100     bool ~> HOL.bool
   101     nat ~> Nat.nat
   102 
   103   constants
   104     Trueprop ~> HOL.Trueprop
   105     True ~> HOL.True
   106     False ~> HOL.False
   107     op & ~> HOL.conj
   108     op | ~> HOL.disj
   109     op --> ~> HOL.implies
   110     Not ~> HOL.Not
   111     The ~> HOL.The
   112     All ~> HOL.All
   113     Ex ~> HOL.Ex
   114     Ex1 ~> HOL.Ex1
   115     Let ~> HOL.Let
   116     If ~> HOL.If
   117     Ball ~> Set.Ball
   118     Bex ~> Set.Bex
   119     Suc ~> Nat.Suc
   120     Pair ~> Product_Type.Pair
   121     fst ~> Product_Type.fst
   122     snd ~> Product_Type.snd
   123     curry ~> Product_Type.curry
   124     op : ~> Set.member
   125     Collect ~> Set.Collect
   126 
   127 INCOMPATIBILITY.
   128 
   129 * Removed simplifier congruence rule of "prod_case", as has for long
   130 been the case with "split".  INCOMPATIBILITY.
   131 
   132 * Datatype package: theorems generated for executable equality
   133 (class eq) carry proper names and are treated as default code
   134 equations.
   135 
   136 * List.thy: use various operations from the Haskell prelude when
   137 generating Haskell code.
   138 
   139 * code_simp.ML and method code_simp: simplification with rules determined
   140 by code generator.
   141 
   142 * code generator: do not print function definitions for case
   143 combinators any longer.
   144 
   145 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   146 theorems are now stated in terms of euclidean spaces instead of finite
   147 cartesian products.
   148 
   149   types
   150     real ^ 'n ~>  'a::real_vector
   151               ~>  'a::euclidean_space
   152               ~>  'a::ordered_euclidean_space
   153         (depends on your needs)
   154 
   155   constants
   156      _ $ _        ~> _ $$ _
   157      \<chi> x. _  ~> \<chi>\<chi> x. _
   158      CARD('n)     ~> DIM('a)
   159 
   160 Also note that the indices are now natural numbers and not from some finite
   161 type. Finite cartesian products of euclidean spaces, products of euclidean
   162 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   163 
   164 INCOMPATIBILITY.
   165 
   166 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   167 as value for measures. Introduces Lebesgue Measure based on the integral in
   168 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   169 spaces.
   170 
   171  INCOMPATIBILITY.
   172 
   173 * Inductive package: offers new command "inductive_simps" to automatically
   174 derive instantiated and simplified equations for inductive predicates,
   175 similar to inductive_cases.
   176 
   177 
   178 *** FOL ***
   179 
   180 * All constant names are now qualified.  INCOMPATIBILITY.
   181 
   182 
   183 *** ZF ***
   184 
   185 * All constant names are now qualified.  INCOMPATIBILITY.
   186 
   187 
   188 *** ML ***
   189 
   190 * ML antiquotations @{theory} and @{theory_ref} refer to named
   191 theories from the ancestry of the current context, not any accidental
   192 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   193 change in semantics.
   194 
   195 
   196 *** System ***
   197 
   198 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   199 
   200 
   201 
   202 New in Isabelle2009-2 (June 2010)
   203 ---------------------------------
   204 
   205 *** General ***
   206 
   207 * Authentic syntax for *all* logical entities (type classes, type
   208 constructors, term constants): provides simple and robust
   209 correspondence between formal entities and concrete syntax.  Within
   210 the parse tree / AST representations, "constants" are decorated by
   211 their category (class, type, const) and spelled out explicitly with
   212 their full internal name.
   213 
   214 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   215 and translations (translation rules and translation functions in ML).
   216 Some hints on upgrading:
   217 
   218   - Many existing uses of 'syntax' and 'translations' can be replaced
   219     by more modern 'type_notation', 'notation' and 'abbreviation',
   220     which are independent of this issue.
   221 
   222   - 'translations' require markup within the AST; the term syntax
   223     provides the following special forms:
   224 
   225       CONST c   -- produces syntax version of constant c from context
   226       XCONST c  -- literally c, checked as constant from context
   227       c         -- literally c, if declared by 'syntax'
   228 
   229     Plain identifiers are treated as AST variables -- occasionally the
   230     system indicates accidental variables via the error "rhs contains
   231     extra variables".
   232 
   233     Type classes and type constructors are marked according to their
   234     concrete syntax.  Some old translations rules need to be written
   235     for the "type" category, using type constructor application
   236     instead of pseudo-term application of the default category
   237     "logic".
   238 
   239   - 'parse_translation' etc. in ML may use the following
   240     antiquotations:
   241 
   242       @{class_syntax c}   -- type class c within parse tree / AST
   243       @{term_syntax c}    -- type constructor c within parse tree / AST
   244       @{const_syntax c}   -- ML version of "CONST c" above
   245       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   246 
   247   - Literal types within 'typed_print_translations', i.e. those *not*
   248     represented as pseudo-terms are represented verbatim.  Use @{class
   249     c} or @{type_name c} here instead of the above syntax
   250     antiquotations.
   251 
   252 Note that old non-authentic syntax was based on unqualified base
   253 names, so all of the above "constant" names would coincide.  Recall
   254 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   255 diagnose syntax problems.
   256 
   257 * Type constructors admit general mixfix syntax, not just infix.
   258 
   259 * Concrete syntax may be attached to local entities without a proof
   260 body, too.  This works via regular mixfix annotations for 'fix',
   261 'def', 'obtain' etc. or via the explicit 'write' command, which is
   262 similar to the 'notation' command in theory specifications.
   263 
   264 * Discontinued unnamed infix syntax (legacy feature for many years) --
   265 need to specify constant name and syntax separately.  Internal ML
   266 datatype constructors have been renamed from InfixName to Infix etc.
   267 Minor INCOMPATIBILITY.
   268 
   269 * Schematic theorem statements need to be explicitly markup as such,
   270 via commands 'schematic_lemma', 'schematic_theorem',
   271 'schematic_corollary'.  Thus the relevance of the proof is made
   272 syntactically clear, which impacts performance in a parallel or
   273 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   274 
   275 * Use of cumulative prems via "!" in some proof methods has been
   276 discontinued (old legacy feature).
   277 
   278 * References 'trace_simp' and 'debug_simp' have been replaced by
   279 configuration options stored in the context. Enabling tracing (the
   280 case of debugging is similar) in proofs works via
   281 
   282   using [[trace_simp = true]]
   283 
   284 Tracing is then active for all invocations of the simplifier in
   285 subsequent goal refinement steps. Tracing may also still be enabled or
   286 disabled via the ProofGeneral settings menu.
   287 
   288 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   289 'hide_fact' replace the former 'hide' KIND command.  Minor
   290 INCOMPATIBILITY.
   291 
   292 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   293 more efficient than combinations with -q1 or -q2.
   294 
   295 
   296 *** Pure ***
   297 
   298 * Proofterms record type-class reasoning explicitly, using the
   299 "unconstrain" operation internally.  This eliminates all sort
   300 constraints from a theorem and proof, introducing explicit
   301 OFCLASS-premises.  On the proof term level, this operation is
   302 automatically applied at theorem boundaries, such that closed proofs
   303 are always free of sort constraints.  INCOMPATIBILITY for tools that
   304 inspect proof terms.
   305 
   306 * Local theory specifications may depend on extra type variables that
   307 are not present in the result type -- arguments TYPE('a) :: 'a itself
   308 are added internally.  For example:
   309 
   310   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   311 
   312 * Predicates of locales introduced by classes carry a mandatory
   313 "class" prefix.  INCOMPATIBILITY.
   314 
   315 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   316 
   317 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   318 'class' instead.
   319 
   320 * Command 'code_reflect' allows to incorporate generated ML code into
   321 runtime environment; replaces immature code_datatype antiquotation.
   322 INCOMPATIBILITY.
   323 
   324 * Code generator: simple concept for abstract datatypes obeying
   325 invariants.
   326 
   327 * Code generator: details of internal data cache have no impact on the
   328 user space functionality any longer.
   329 
   330 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   331 subgoals.  This is more appropriate for interpretations with 'where'.
   332 INCOMPATIBILITY.
   333 
   334 * Command 'example_proof' opens an empty proof body.  This allows to
   335 experiment with Isar, without producing any persistent result.
   336 
   337 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   338 within a local theory context, with explicit checking of the
   339 constructors involved (in contrast to the raw 'syntax' versions).
   340 
   341 * Commands 'types' and 'typedecl' now work within a local theory
   342 context -- without introducing dependencies on parameters or
   343 assumptions, which is not possible in Isabelle/Pure.
   344 
   345 * Command 'defaultsort' has been renamed to 'default_sort', it works
   346 within a local theory context.  Minor INCOMPATIBILITY.
   347 
   348 
   349 *** HOL ***
   350 
   351 * Command 'typedef' now works within a local theory context -- without
   352 introducing dependencies on parameters or assumptions, which is not
   353 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   354 contain multiple interpretations of local typedefs (with different
   355 non-emptiness proofs), even in a global theory context.
   356 
   357 * New package for quotient types.  Commands 'quotient_type' and
   358 'quotient_definition' may be used for defining types and constants by
   359 quotient constructions.  An example is the type of integers created by
   360 quotienting pairs of natural numbers:
   361 
   362   fun
   363     intrel :: "(nat * nat) => (nat * nat) => bool"
   364   where
   365     "intrel (x, y) (u, v) = (x + v = u + y)"
   366 
   367   quotient_type int = "nat * nat" / intrel
   368     by (auto simp add: equivp_def expand_fun_eq)
   369 
   370   quotient_definition
   371     "0::int" is "(0::nat, 0::nat)"
   372 
   373 The method "lifting" can be used to lift of theorems from the
   374 underlying "raw" type to the quotient type.  The example
   375 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   376 construction and provides a reasoning infrastructure for finite sets.
   377 
   378 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   379 clash with new theory Quotient in Main HOL.
   380 
   381 * Moved the SMT binding into the main HOL session, eliminating
   382 separate HOL-SMT session.
   383 
   384 * List membership infix mem operation is only an input abbreviation.
   385 INCOMPATIBILITY.
   386 
   387 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   388 for future developements; former Library/Word.thy is still present in
   389 the AFP entry RSAPPS.
   390 
   391 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   392 longer shadowed.  INCOMPATIBILITY.
   393 
   394 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   395 INCOMPATIBILITY.
   396 
   397 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   398 INCOMPATIBILITY.
   399 
   400 * Dropped normalizing_semiring etc; use the facts in semiring classes
   401 instead.  INCOMPATIBILITY.
   402 
   403 * Dropped several real-specific versions of lemmas about floor and
   404 ceiling; use the generic lemmas from theory "Archimedean_Field"
   405 instead.  INCOMPATIBILITY.
   406 
   407   floor_number_of_eq         ~> floor_number_of
   408   le_floor_eq_number_of      ~> number_of_le_floor
   409   le_floor_eq_zero           ~> zero_le_floor
   410   le_floor_eq_one            ~> one_le_floor
   411   floor_less_eq_number_of    ~> floor_less_number_of
   412   floor_less_eq_zero         ~> floor_less_zero
   413   floor_less_eq_one          ~> floor_less_one
   414   less_floor_eq_number_of    ~> number_of_less_floor
   415   less_floor_eq_zero         ~> zero_less_floor
   416   less_floor_eq_one          ~> one_less_floor
   417   floor_le_eq_number_of      ~> floor_le_number_of
   418   floor_le_eq_zero           ~> floor_le_zero
   419   floor_le_eq_one            ~> floor_le_one
   420   floor_subtract_number_of   ~> floor_diff_number_of
   421   floor_subtract_one         ~> floor_diff_one
   422   ceiling_number_of_eq       ~> ceiling_number_of
   423   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   424   ceiling_le_zero_eq         ~> ceiling_le_zero
   425   ceiling_le_eq_one          ~> ceiling_le_one
   426   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   427   less_ceiling_eq_zero       ~> zero_less_ceiling
   428   less_ceiling_eq_one        ~> one_less_ceiling
   429   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   430   ceiling_less_eq_zero       ~> ceiling_less_zero
   431   ceiling_less_eq_one        ~> ceiling_less_one
   432   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   433   le_ceiling_eq_zero         ~> zero_le_ceiling
   434   le_ceiling_eq_one          ~> one_le_ceiling
   435   ceiling_subtract_number_of ~> ceiling_diff_number_of
   436   ceiling_subtract_one       ~> ceiling_diff_one
   437 
   438 * Theory "Finite_Set": various folding_XXX locales facilitate the
   439 application of the various fold combinators on finite sets.
   440 
   441 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   442 provides abstract red-black tree type which is backed by "RBT_Impl" as
   443 implementation.  INCOMPATIBILTY.
   444 
   445 * Theory Library/Coinductive_List has been removed -- superseded by
   446 AFP/thys/Coinductive.
   447 
   448 * Theory PReal, including the type "preal" and related operations, has
   449 been removed.  INCOMPATIBILITY.
   450 
   451 * Real: new development using Cauchy Sequences.
   452 
   453 * Split off theory "Big_Operators" containing setsum, setprod,
   454 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   455 
   456 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   457 "Int" etc.  INCOMPATIBILITY.
   458 
   459 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   460 
   461 * New set of rules "ac_simps" provides combined assoc / commute
   462 rewrites for all interpretations of the appropriate generic locales.
   463 
   464 * Renamed theory "OrderedGroup" to "Groups" and split theory
   465 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   466 appropriate and more consistent names suitable for name prefixes
   467 within the HOL theories.  INCOMPATIBILITY.
   468 
   469 * Some generic constants have been put to appropriate theories:
   470   - less_eq, less: Orderings
   471   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   472   - inverse, divide: Rings
   473 INCOMPATIBILITY.
   474 
   475 * More consistent naming of type classes involving orderings (and
   476 lattices):
   477 
   478     lower_semilattice                   ~> semilattice_inf
   479     upper_semilattice                   ~> semilattice_sup
   480 
   481     dense_linear_order                  ~> dense_linorder
   482 
   483     pordered_ab_group_add               ~> ordered_ab_group_add
   484     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   485     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   486     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   487     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   488     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   489     pordered_cancel_semiring            ~> ordered_cancel_semiring
   490     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   491     pordered_comm_ring                  ~> ordered_comm_ring
   492     pordered_comm_semiring              ~> ordered_comm_semiring
   493     pordered_ring                       ~> ordered_ring
   494     pordered_ring_abs                   ~> ordered_ring_abs
   495     pordered_semiring                   ~> ordered_semiring
   496 
   497     ordered_ab_group_add                ~> linordered_ab_group_add
   498     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   499     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   500     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   501     ordered_field                       ~> linordered_field
   502     ordered_field_no_lb                 ~> linordered_field_no_lb
   503     ordered_field_no_ub                 ~> linordered_field_no_ub
   504     ordered_field_dense_linear_order    ~> dense_linordered_field
   505     ordered_idom                        ~> linordered_idom
   506     ordered_ring                        ~> linordered_ring
   507     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   508     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   509     ordered_ring_strict                 ~> linordered_ring_strict
   510     ordered_semidom                     ~> linordered_semidom
   511     ordered_semiring                    ~> linordered_semiring
   512     ordered_semiring_1                  ~> linordered_semiring_1
   513     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   514     ordered_semiring_strict             ~> linordered_semiring_strict
   515 
   516   The following slightly odd type classes have been moved to a
   517   separate theory Library/Lattice_Algebras:
   518 
   519     lordered_ab_group_add               ~> lattice_ab_group_add
   520     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   521     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   522     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   523     lordered_ring                       ~> lattice_ring
   524 
   525 INCOMPATIBILITY.
   526 
   527 * Refined field classes:
   528   - classes division_ring_inverse_zero, field_inverse_zero,
   529     linordered_field_inverse_zero include rule inverse 0 = 0 --
   530     subsumes former division_by_zero class;
   531   - numerous lemmas have been ported from field to division_ring.
   532 INCOMPATIBILITY.
   533 
   534 * Refined algebra theorem collections:
   535   - dropped theorem group group_simps, use algebra_simps instead;
   536   - dropped theorem group ring_simps, use field_simps instead;
   537   - proper theorem collection field_simps subsumes former theorem
   538     groups field_eq_simps and field_simps;
   539   - dropped lemma eq_minus_self_iff which is a duplicate for
   540     equal_neg_zero.
   541 INCOMPATIBILITY.
   542 
   543 * Theory Finite_Set and List: some lemmas have been generalized from
   544 sets to lattices:
   545 
   546   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   547   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   548   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   549   union_Union_fold_union        ~> sup_Sup_fold_sup
   550   Inter_fold_inter              ~> Inf_fold_inf
   551   Union_fold_union              ~> Sup_fold_sup
   552   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   553   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   554   INTER_fold_inter              ~> INFI_fold_inf
   555   UNION_fold_union              ~> SUPR_fold_sup
   556 
   557 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   558 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   559 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   560 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   561 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   562 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   563 
   564 * Reorganized theory Multiset: swapped notation of pointwise and
   565 multiset order:
   566 
   567   - pointwise ordering is instance of class order with standard syntax
   568     <= and <;
   569   - multiset ordering has syntax <=# and <#; partial order properties
   570     are provided by means of interpretation with prefix
   571     multiset_order;
   572   - less duplication, less historical organization of sections,
   573     conversion from associations lists to multisets, rudimentary code
   574     generation;
   575   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   576     if needed.
   577 
   578 Renamed:
   579 
   580   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   581   multi_count_ext  ~>  multiset_ext
   582   diff_union_inverse2  ~>  diff_union_cancelR
   583 
   584 INCOMPATIBILITY.
   585 
   586 * Theory Permutation: replaced local "remove" by List.remove1.
   587 
   588 * Code generation: ML and OCaml code is decorated with signatures.
   589 
   590 * Theory List: added transpose.
   591 
   592 * Library/Nat_Bijection.thy is a collection of bijective functions
   593 between nat and other types, which supersedes the older libraries
   594 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   595 
   596   Constants:
   597   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   598   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   599   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   600   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   601   Countable.pair_encode           ~> prod_encode
   602   NatIso.prod2nat                 ~> prod_encode
   603   NatIso.nat2prod                 ~> prod_decode
   604   NatIso.sum2nat                  ~> sum_encode
   605   NatIso.nat2sum                  ~> sum_decode
   606   NatIso.list2nat                 ~> list_encode
   607   NatIso.nat2list                 ~> list_decode
   608   NatIso.set2nat                  ~> set_encode
   609   NatIso.nat2set                  ~> set_decode
   610 
   611   Lemmas:
   612   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   613   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   614   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   615   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   616   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   617   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   618   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   619   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   620   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   621   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   622   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   623   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   624   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   625 
   626 * Sledgehammer:
   627   - Renamed ATP commands:
   628     atp_info     ~> sledgehammer running_atps
   629     atp_kill     ~> sledgehammer kill_atps
   630     atp_messages ~> sledgehammer messages
   631     atp_minimize ~> sledgehammer minimize
   632     print_atps   ~> sledgehammer available_atps
   633     INCOMPATIBILITY.
   634   - Added user's manual ("isabelle doc sledgehammer").
   635   - Added option syntax and "sledgehammer_params" to customize
   636     Sledgehammer's behavior.  See the manual for details.
   637   - Modified the Isar proof reconstruction code so that it produces
   638     direct proofs rather than proofs by contradiction.  (This feature
   639     is still experimental.)
   640   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   641     full-typed mode.
   642   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   643 
   644 * Nitpick:
   645   - Added and implemented "binary_ints" and "bits" options.
   646   - Added "std" option and implemented support for nonstandard models.
   647   - Added and implemented "finitize" option to improve the precision
   648     of infinite datatypes based on a monotonicity analysis.
   649   - Added support for quotient types.
   650   - Added support for "specification" and "ax_specification"
   651     constructs.
   652   - Added support for local definitions (for "function" and
   653     "termination" proofs).
   654   - Added support for term postprocessors.
   655   - Optimized "Multiset.multiset" and "FinFun.finfun".
   656   - Improved efficiency of "destroy_constrs" optimization.
   657   - Fixed soundness bugs related to "destroy_constrs" optimization and
   658     record getters.
   659   - Fixed soundness bug related to higher-order constructors.
   660   - Fixed soundness bug when "full_descrs" is enabled.
   661   - Improved precision of set constructs.
   662   - Added "atoms" option.
   663   - Added cache to speed up repeated Kodkod invocations on the same
   664     problems.
   665   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   666     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   667     "SAT4J_Light".  INCOMPATIBILITY.
   668   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   669     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   670   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   671 
   672 * Method "induct" now takes instantiations of the form t, where t is not
   673   a variable, as a shorthand for "x == t", where x is a fresh variable.
   674   If this is not intended, t has to be enclosed in parentheses.
   675   By default, the equalities generated by definitional instantiations
   676   are pre-simplified, which may cause parameters of inductive cases
   677   to disappear, or may even delete some of the inductive cases.
   678   Use "induct (no_simp)" instead of "induct" to restore the old
   679   behaviour. The (no_simp) option is also understood by the "cases"
   680   and "nominal_induct" methods, which now perform pre-simplification, too.
   681   INCOMPATIBILITY.
   682 
   683 
   684 *** HOLCF ***
   685 
   686 * Variable names in lemmas generated by the domain package have
   687 changed; the naming scheme is now consistent with the HOL datatype
   688 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   689 
   690 * The domain package no longer defines the function "foo_copy" for
   691 recursive domain "foo".  The reach lemma is now stated directly in
   692 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   693 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   694 
   695 * Most definedness lemmas generated by the domain package (previously
   696 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   697 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   698 Proofs that used definedness lemmas as intro rules may break,
   699 potential INCOMPATIBILITY.
   700 
   701 * Induction and casedist rules generated by the domain package now
   702 declare proper case_names (one called "bottom", and one named for each
   703 constructor).  INCOMPATIBILITY.
   704 
   705 * For mutually-recursive domains, separate "reach" and "take_lemma"
   706 rules are generated for each domain, INCOMPATIBILITY.
   707 
   708   foo_bar.reach       ~> foo.reach  bar.reach
   709   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   710 
   711 * Some lemmas generated by the domain package have been renamed for
   712 consistency with the datatype package, INCOMPATIBILITY.
   713 
   714   foo.ind        ~> foo.induct
   715   foo.finite_ind ~> foo.finite_induct
   716   foo.coind      ~> foo.coinduct
   717   foo.casedist   ~> foo.exhaust
   718   foo.exhaust    ~> foo.nchotomy
   719 
   720 * For consistency with other definition packages, the fixrec package
   721 now generates qualified theorem names, INCOMPATIBILITY.
   722 
   723   foo_simps  ~> foo.simps
   724   foo_unfold ~> foo.unfold
   725   foo_induct ~> foo.induct
   726 
   727 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   728 method and internal fixrec proofs now use the default simpset instead.
   729 INCOMPATIBILITY.
   730 
   731 * The "contlub" predicate has been removed.  Proof scripts should use
   732 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   733 
   734 * The "admw" predicate has been removed, INCOMPATIBILITY.
   735 
   736 * The constants cpair, cfst, and csnd have been removed in favor of
   737 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   738 
   739 
   740 *** ML ***
   741 
   742 * Antiquotations for basic formal entities:
   743 
   744     @{class NAME}         -- type class
   745     @{class_syntax NAME}  -- syntax representation of the above
   746 
   747     @{type_name NAME}     -- logical type
   748     @{type_abbrev NAME}   -- type abbreviation
   749     @{nonterminal NAME}   -- type of concrete syntactic category
   750     @{type_syntax NAME}   -- syntax representation of any of the above
   751 
   752     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   753     @{const_abbrev NAME}  -- abbreviated constant
   754     @{const_syntax NAME}  -- syntax representation of any of the above
   755 
   756 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   757 syntax constant (cf. 'syntax' command).
   758 
   759 * Antiquotation @{make_string} inlines a function to print arbitrary
   760 values similar to the ML toplevel.  The result is compiler dependent
   761 and may fall back on "?" in certain situations.
   762 
   763 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   764 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   765 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   766 not work with the asynchronous Isar document model.
   767 
   768 * Configuration options now admit dynamic default values, depending on
   769 the context or even global references.
   770 
   771 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   772 uses an efficient external library if available (for Poly/ML).
   773 
   774 * Renamed some important ML structures, while keeping the old names
   775 for some time as aliases within the structure Legacy:
   776 
   777   OuterKeyword  ~>  Keyword
   778   OuterLex      ~>  Token
   779   OuterParse    ~>  Parse
   780   OuterSyntax   ~>  Outer_Syntax
   781   PrintMode     ~>  Print_Mode
   782   SpecParse     ~>  Parse_Spec
   783   ThyInfo       ~>  Thy_Info
   784   ThyLoad       ~>  Thy_Load
   785   ThyOutput     ~>  Thy_Output
   786   TypeInfer     ~>  Type_Infer
   787 
   788 Note that "open Legacy" simplifies porting of sources, but forgetting
   789 to remove it again will complicate porting again in the future.
   790 
   791 * Most operations that refer to a global context are named
   792 accordingly, e.g. Simplifier.global_context or
   793 ProofContext.init_global.  There are some situations where a global
   794 context actually works, but under normal circumstances one needs to
   795 pass the proper local context through the code!
   796 
   797 * Discontinued old TheoryDataFun with its copy/init operation -- data
   798 needs to be pure.  Functor Theory_Data_PP retains the traditional
   799 Pretty.pp argument to merge, which is absent in the standard
   800 Theory_Data version.
   801 
   802 * Sorts.certify_sort and derived "cert" operations for types and terms
   803 no longer minimize sorts.  Thus certification at the boundary of the
   804 inference kernel becomes invariant under addition of class relations,
   805 which is an important monotonicity principle.  Sorts are now minimized
   806 in the syntax layer only, at the boundary between the end-user and the
   807 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   808 explicitly in rare situations.
   809 
   810 * Renamed old-style Drule.standard to Drule.export_without_context, to
   811 emphasize that this is in no way a standard operation.
   812 INCOMPATIBILITY.
   813 
   814 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   815 usual for resolution.  Rare INCOMPATIBILITY.
   816 
   817 * Renamed varify/unvarify operations to varify_global/unvarify_global
   818 to emphasize that these only work in a global situation (which is
   819 quite rare).
   820 
   821 * Curried take and drop in library.ML; negative length is interpreted
   822 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   823 
   824 * Proof terms: type substitutions on proof constants now use canonical
   825 order of type variables.  INCOMPATIBILITY for tools working with proof
   826 terms.
   827 
   828 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   829 may no longer carry premises.  User-level specifications are
   830 transformed accordingly by Thm.add_axiom/add_def.
   831 
   832 
   833 *** System ***
   834 
   835 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   836 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   837 proof terms are enabled unconditionally in the new HOL-Proofs image.
   838 
   839 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   840 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   841 respectively.
   842 
   843 * Old lib/scripts/polyml-platform is superseded by the
   844 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   845 variant, even on a 64 bit machine.  The following example setting
   846 prefers 64 bit if available:
   847 
   848   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   849 
   850 * The preliminary Isabelle/jEdit application demonstrates the emerging
   851 Isabelle/Scala layer for advanced prover interaction and integration.
   852 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   853 component.
   854 
   855 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   856 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   857 similar to the default assignment of the document preparation system
   858 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   859 provides some operations for direct access to the font without asking
   860 the user for manual installation.
   861 
   862 
   863 
   864 New in Isabelle2009-1 (December 2009)
   865 -------------------------------------
   866 
   867 *** General ***
   868 
   869 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   870 one backslash should be used, even in ML sources.
   871 
   872 
   873 *** Pure ***
   874 
   875 * Locale interpretation propagates mixins along the locale hierarchy.
   876 The currently only available mixins are the equations used to map
   877 local definitions to terms of the target domain of an interpretation.
   878 
   879 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   880 loc" to print all interpretations of locale "loc" in the theory.
   881 Interpretations in proofs are not shown.
   882 
   883 * Thoroughly revised locales tutorial.  New section on conditional
   884 interpretation.
   885 
   886 * On instantiation of classes, remaining undefined class parameters
   887 are formally declared.  INCOMPATIBILITY.
   888 
   889 
   890 *** Document preparation ***
   891 
   892 * New generalized style concept for printing terms: @{foo (style) ...}
   893 instead of @{foo_style style ...}  (old form is still retained for
   894 backward compatibility).  Styles can be also applied for
   895 antiquotations prop, term_type and typeof.
   896 
   897 
   898 *** HOL ***
   899 
   900 * New proof method "smt" for a combination of first-order logic with
   901 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   902 fixed-size bitvectors; there is also basic support for higher-order
   903 features (esp. lambda abstractions).  It is an incomplete decision
   904 procedure based on external SMT solvers using the oracle mechanism;
   905 for the SMT solver Z3, this method is proof-producing.  Certificates
   906 are provided to avoid calling the external solvers solely for
   907 re-checking proofs.  Due to a remote SMT service there is no need for
   908 installing SMT solvers locally.  See src/HOL/SMT.
   909 
   910 * New commands to load and prove verification conditions generated by
   911 the Boogie program verifier or derived systems (e.g. the Verifying C
   912 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   913 
   914 * New counterexample generator tool 'nitpick' based on the Kodkod
   915 relational model finder.  See src/HOL/Tools/Nitpick and
   916 src/HOL/Nitpick_Examples.
   917 
   918 * New commands 'code_pred' and 'values' to invoke the predicate
   919 compiler and to enumerate values of inductive predicates.
   920 
   921 * A tabled implementation of the reflexive transitive closure.
   922 
   923 * New implementation of quickcheck uses generic code generator;
   924 default generators are provided for all suitable HOL types, records
   925 and datatypes.  Old quickcheck can be re-activated importing theory
   926 Library/SML_Quickcheck.
   927 
   928 * New testing tool Mirabelle for automated proof tools.  Applies
   929 several tools and tactics like sledgehammer, metis, or quickcheck, to
   930 every proof step in a theory.  To be used in batch mode via the
   931 "mirabelle" utility.
   932 
   933 * New proof method "sos" (sum of squares) for nonlinear real
   934 arithmetic (originally due to John Harison). It requires theory
   935 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   936 works well in practice on quantifier-free real arithmetic with +, -,
   937 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   938 inequalities between polynomials.  It makes use of external
   939 semidefinite programming solvers.  Method "sos" generates a
   940 certificate that can be pasted into the proof thus avoiding the need
   941 to call an external tool every time the proof is checked.  See
   942 src/HOL/Library/Sum_Of_Squares.
   943 
   944 * New method "linarith" invokes existing linear arithmetic decision
   945 procedure only.
   946 
   947 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   948 
   949 * New Sledgehammer option "Full Types" in Proof General settings menu.
   950 Causes full type information to be output to the ATPs.  This slows
   951 ATPs down considerably but eliminates a source of unsound "proofs"
   952 that fail later.
   953 
   954 * New method "metisFT": A version of metis that uses full type
   955 information in order to avoid failures of proof reconstruction.
   956 
   957 * New evaluator "approximate" approximates an real valued term using
   958 the same method as the approximation method.
   959 
   960 * Method "approximate" now supports arithmetic expressions as
   961 boundaries of intervals and implements interval splitting and Taylor
   962 series expansion.
   963 
   964 * ML antiquotation @{code_datatype} inserts definition of a datatype
   965 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   966 
   967 * New theory SupInf of the supremum and infimum operators for sets of
   968 reals.
   969 
   970 * New theory Probability, which contains a development of measure
   971 theory, eventually leading to Lebesgue integration and probability.
   972 
   973 * Extended Multivariate Analysis to include derivation and Brouwer's
   974 fixpoint theorem.
   975 
   976 * Reorganization of number theory, INCOMPATIBILITY:
   977   - new number theory development for nat and int, in theories Divides
   978     and GCD as well as in new session Number_Theory
   979   - some constants and facts now suffixed with _nat and _int
   980     accordingly
   981   - former session NumberTheory now named Old_Number_Theory, including
   982     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   983   - moved theory Pocklington from src/HOL/Library to
   984     src/HOL/Old_Number_Theory
   985 
   986 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   987 lcm of finite and infinite sets. It is shown that they form a complete
   988 lattice.
   989 
   990 * Class semiring_div requires superclass no_zero_divisors and proof of
   991 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   992 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   993 generalized to class semiring_div, subsuming former theorems
   994 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   995 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   996 INCOMPATIBILITY.
   997 
   998 * Refinements to lattice classes and sets:
   999   - less default intro/elim rules in locale variant, more default
  1000     intro/elim rules in class variant: more uniformity
  1001   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1002     le_inf_iff
  1003   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1004     sup_aci)
  1005   - renamed ACI to inf_sup_aci
  1006   - new class "boolean_algebra"
  1007   - class "complete_lattice" moved to separate theory
  1008     "Complete_Lattice"; corresponding constants (and abbreviations)
  1009     renamed and with authentic syntax:
  1010     Set.Inf ~>    Complete_Lattice.Inf
  1011     Set.Sup ~>    Complete_Lattice.Sup
  1012     Set.INFI ~>   Complete_Lattice.INFI
  1013     Set.SUPR ~>   Complete_Lattice.SUPR
  1014     Set.Inter ~>  Complete_Lattice.Inter
  1015     Set.Union ~>  Complete_Lattice.Union
  1016     Set.INTER ~>  Complete_Lattice.INTER
  1017     Set.UNION ~>  Complete_Lattice.UNION
  1018   - authentic syntax for
  1019     Set.Pow
  1020     Set.image
  1021   - mere abbreviations:
  1022     Set.empty               (for bot)
  1023     Set.UNIV                (for top)
  1024     Set.inter               (for inf, formerly Set.Int)
  1025     Set.union               (for sup, formerly Set.Un)
  1026     Complete_Lattice.Inter  (for Inf)
  1027     Complete_Lattice.Union  (for Sup)
  1028     Complete_Lattice.INTER  (for INFI)
  1029     Complete_Lattice.UNION  (for SUPR)
  1030   - object-logic definitions as far as appropriate
  1031 
  1032 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1033 Un_subset_iff are explicitly deleted as default simp rules; then also
  1034 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1035 deleted to achieve the desired effect.
  1036 
  1037 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1038 rules by default any longer; the same applies to min_max.inf_absorb1
  1039 etc.  INCOMPATIBILITY.
  1040 
  1041 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1042 pred_set_conv by default.  INCOMPATIBILITY.
  1043 
  1044 * Power operations on relations and functions are now one dedicated
  1045 constant "compow" with infix syntax "^^".  Power operation on
  1046 multiplicative monoids retains syntax "^" and is now defined generic
  1047 in class power.  INCOMPATIBILITY.
  1048 
  1049 * Relation composition "R O S" now has a more standard argument order:
  1050 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1051 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1052 break, since the O_assoc rule was not rewritten like this.  Fix using
  1053 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1054 
  1055 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1056 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1057 INCOMPATIBILITY.
  1058 
  1059 * Most rules produced by inductive and datatype package have mandatory
  1060 prefixes.  INCOMPATIBILITY.
  1061 
  1062 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1063 the attribute of the same name.  Each of the theorems in the list
  1064 DERIV_intros assumes composition with an additional function and
  1065 matches a variable to the derivative, which has to be solved by the
  1066 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1067 of most elementary terms.  Former Maclauren.DERIV_tac and
  1068 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1069 INCOMPATIBILITY.
  1070 
  1071 * Code generator attributes follow the usual underscore convention:
  1072     code_unfold     replaces    code unfold
  1073     code_post       replaces    code post
  1074     etc.
  1075   INCOMPATIBILITY.
  1076 
  1077 * Renamed methods:
  1078     sizechange -> size_change
  1079     induct_scheme -> induction_schema
  1080   INCOMPATIBILITY.
  1081 
  1082 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1083 INCOMPATIBILITY, use "undefined" directly.
  1084 
  1085 * Renamed theorems:
  1086     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1087     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1088     Suc_plus1 -> Suc_eq_plus1
  1089     *anti_sym -> *antisym*
  1090     vector_less_eq_def -> vector_le_def
  1091   INCOMPATIBILITY.
  1092 
  1093 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1094 INCOMPATIBILITY.
  1095 
  1096 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1097 INCOMPATIBILITY.
  1098 
  1099 
  1100 *** HOLCF ***
  1101 
  1102 * Theory Representable defines a class "rep" of domains that are
  1103 representable (via an ep-pair) in the universal domain type "udom".
  1104 Instances are provided for all type constructors defined in HOLCF.
  1105 
  1106 * The 'new_domain' command is a purely definitional version of the
  1107 domain package, for representable domains.  Syntax is identical to the
  1108 old domain package.  The 'new_domain' package also supports indirect
  1109 recursion using previously-defined type constructors.  See
  1110 src/HOLCF/ex/New_Domain.thy for examples.
  1111 
  1112 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1113 on the left-hand side of an equation, and then performs
  1114 simplification.  Rewriting is done using rules declared with the
  1115 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1116 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1117 
  1118 * The pattern-match compiler in 'fixrec' can now handle constructors
  1119 with HOL function types.  Pattern-match combinators for the Pair
  1120 constructor are pre-configured.
  1121 
  1122 * The 'fixrec' package now produces better fixed-point induction rules
  1123 for mutually-recursive definitions:  Induction rules have conclusions
  1124 of the form "P foo bar" instead of "P <foo, bar>".
  1125 
  1126 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1127 been renamed to "below".  The name "below" now replaces "less" in many
  1128 theorem names.  (Legacy theorem names using "less" are still supported
  1129 as well.)
  1130 
  1131 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1132 patterns can be used to generate strictness rules, or to make
  1133 functions more strict (much like the bang-patterns supported by the
  1134 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1135 examples.
  1136 
  1137 
  1138 *** ML ***
  1139 
  1140 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1141 errors and run-time exceptions, including detailed source positions.
  1142 
  1143 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1144 identified entries, with some additional information such as source
  1145 position, logical grouping etc.
  1146 
  1147 * Theory and context data is now introduced by the simplified and
  1148 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1149 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1150 copy operation) is still available for some time.
  1151 
  1152 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1153 provides a high-level programming interface to synchronized state
  1154 variables with atomic update.  This works via pure function
  1155 application within a critical section -- its runtime should be as
  1156 short as possible; beware of deadlocks if critical code is nested,
  1157 either directly or indirectly via other synchronized variables!
  1158 
  1159 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1160 wraps raw ML references, explicitly indicating their non-thread-safe
  1161 behaviour.  The Isar toplevel keeps this structure open, to
  1162 accommodate Proof General as well as quick and dirty interactive
  1163 experiments with references.
  1164 
  1165 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1166 parallel tactical reasoning.
  1167 
  1168 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1169 are similar to SUBPROOF, but are slightly more flexible: only the
  1170 specified parts of the subgoal are imported into the context, and the
  1171 body tactic may introduce new subgoals and schematic variables.
  1172 
  1173 * Old tactical METAHYPS, which does not observe the proof context, has
  1174 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1175 or Subgoal.FOCUS etc.
  1176 
  1177 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1178 functors have their own ML name space there is no point to mark them
  1179 separately.)  Minor INCOMPATIBILITY.
  1180 
  1181 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1182 
  1183 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1184 INCOMPATIBILITY.
  1185 
  1186 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1187 mode, which avoids critical setmp.
  1188 
  1189 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1190 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1191 Attrib/Method.setup introduced in Isabelle2009.
  1192 
  1193 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1194 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1195 last resort.  INCOMPATIBILITY.
  1196 
  1197 * Display.pretty_thm now requires a proper context (cf. former
  1198 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1199 or even Display.pretty_thm_without_context as last resort.
  1200 INCOMPATIBILITY.
  1201 
  1202 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1203 Syntax.pretty_typ/term directly, preferably with proper context
  1204 instead of global theory.
  1205 
  1206 
  1207 *** System ***
  1208 
  1209 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1210 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1211 usedir option -q.
  1212 
  1213 * Support for additional "Isabelle components" via etc/components, see
  1214 also the system manual.
  1215 
  1216 * The isabelle makeall tool now operates on all components with
  1217 IsaMakefile, not just hardwired "logics".
  1218 
  1219 * Removed "compress" option from isabelle-process and isabelle usedir;
  1220 this is always enabled.
  1221 
  1222 * Discontinued support for Poly/ML 4.x versions.
  1223 
  1224 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1225 on a given logic image.  This requires the lighttpd webserver and is
  1226 currently supported on Linux only.
  1227 
  1228 
  1229 
  1230 New in Isabelle2009 (April 2009)
  1231 --------------------------------
  1232 
  1233 *** General ***
  1234 
  1235 * Simplified main Isabelle executables, with less surprises on
  1236 case-insensitive file-systems (such as Mac OS).
  1237 
  1238   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1239     "isatool."
  1240 
  1241   - The former "isabelle" alias for "isabelle-process" has been
  1242     removed (should rarely occur to regular users).
  1243 
  1244   - The former "isabelle-interface" and its alias "Isabelle" have been
  1245     removed (interfaces are now regular Isabelle tools).
  1246 
  1247 Within scripts and make files, the Isabelle environment variables
  1248 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1249 respectively.  (The latter are still available as legacy feature.)
  1250 
  1251 The old isabelle-interface wrapper could react in confusing ways if
  1252 the interface was uninstalled or changed otherwise.  Individual
  1253 interface tool configuration is now more explicit, see also the
  1254 Isabelle system manual.  In particular, Proof General is now available
  1255 via "isabelle emacs".
  1256 
  1257 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1258 purge installed copies of Isabelle executables and re-run "isabelle
  1259 install -p ...", or use symlinks.
  1260 
  1261 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1262 old ~/isabelle, which was slightly non-standard and apt to cause
  1263 surprises on case-insensitive file-systems (such as Mac OS).
  1264 
  1265 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1266 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1267 care is required when using older releases of Isabelle.  Note that
  1268 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1269 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1270 
  1271 * Proofs of fully specified statements are run in parallel on
  1272 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1273 a regular 4-core machine, if the initial heap space is made reasonably
  1274 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1275 
  1276 * The main reference manuals ("isar-ref", "implementation", and
  1277 "system") have been updated and extended.  Formally checked references
  1278 as hyperlinks are now available uniformly.
  1279 
  1280 
  1281 *** Pure ***
  1282 
  1283 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1284 respects.  The most important changes are listed below.  See the
  1285 Tutorial on Locales ("locales" manual) for details.
  1286 
  1287 - In locale expressions, instantiation replaces renaming.  Parameters
  1288 must be declared in a for clause.  To aid compatibility with previous
  1289 parameter inheritance, in locale declarations, parameters that are not
  1290 'touched' (instantiation position "_" or omitted) are implicitly added
  1291 with their syntax at the beginning of the for clause.
  1292 
  1293 - Syntax from abbreviations and definitions in locales is available in
  1294 locale expressions and context elements.  The latter is particularly
  1295 useful in locale declarations.
  1296 
  1297 - More flexible mechanisms to qualify names generated by locale
  1298 expressions.  Qualifiers (prefixes) may be specified in locale
  1299 expressions, and can be marked as mandatory (syntax: "name!:") or
  1300 optional (syntax "name?:").  The default depends for plain "name:"
  1301 depends on the situation where a locale expression is used: in
  1302 commands 'locale' and 'sublocale' prefixes are optional, in
  1303 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1304 implicit qualifiers derived from the parameter names of a locale are
  1305 no longer generated.
  1306 
  1307 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1308 instantiation clause in "interpretation" and "interpret" (square
  1309 brackets) is no longer available.  Use locale expressions.
  1310 
  1311 - When converting proof scripts, mandatory qualifiers in
  1312 'interpretation' and 'interpret' should be retained by default, even
  1313 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1314 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1315 in locale expressions range over a single locale instance only.
  1316 
  1317 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1318 In existing theorem specifications replace the includes element by the
  1319 respective context elements of the included locale, omitting those
  1320 that are already present in the theorem specification.  Multiple
  1321 assume elements of a locale should be replaced by a single one
  1322 involving the locale predicate.  In the proof body, declarations (most
  1323 notably theorems) may be regained by interpreting the respective
  1324 locales in the proof context as required (command "interpret").
  1325 
  1326 If using "includes" in replacement of a target solely because the
  1327 parameter types in the theorem are not as general as in the target,
  1328 consider declaring a new locale with additional type constraints on
  1329 the parameters (context element "constrains").
  1330 
  1331 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1332 
  1333 - Locale interpretation commands no longer attempt to simplify goal.
  1334 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1335 methods intro_locales and unfold_locales to clarify.
  1336 
  1337 - Locale interpretation commands no longer accept interpretation
  1338 attributes.  INCOMPATIBILITY.
  1339 
  1340 * Class declaration: so-called "base sort" must not be given in import
  1341 list any longer, but is inferred from the specification.  Particularly
  1342 in HOL, write
  1343 
  1344     class foo = ...
  1345 
  1346 instead of
  1347 
  1348     class foo = type + ...
  1349 
  1350 * Class target: global versions of theorems stemming do not carry a
  1351 parameter prefix any longer.  INCOMPATIBILITY.
  1352 
  1353 * Class 'instance' command no longer accepts attached definitions.
  1354 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1355 
  1356 * Recovered hiding of consts, which was accidentally broken in
  1357 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1358 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1359 
  1360 * Slightly more coherent Pure syntax, with updated documentation in
  1361 isar-ref manual.  Removed locales meta_term_syntax and
  1362 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1363 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1364 directly in regular applications.
  1365 
  1366 * There is a new syntactic category "float_const" for signed decimal
  1367 fractions (e.g. 123.45 or -123.45).
  1368 
  1369 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1370 interface with 'setup' command instead.
  1371 
  1372 * Command 'local_setup' is similar to 'setup', but operates on a local
  1373 theory context.
  1374 
  1375 * The 'axiomatization' command now only works within a global theory
  1376 context.  INCOMPATIBILITY.
  1377 
  1378 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1379 hypotheses.  Sorts required in the course of reasoning need to be
  1380 covered by the constraints in the initial statement, completed by the
  1381 type instance information of the background theory.  Non-trivial sort
  1382 hypotheses, which rarely occur in practice, may be specified via
  1383 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1384 
  1385   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1386 
  1387 The result contains an implicit sort hypotheses as before --
  1388 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1389 normalization.
  1390 
  1391 * Generalized Isar history, with support for linear undo, direct state
  1392 addressing etc.
  1393 
  1394 * Changed defaults for unify configuration options:
  1395 
  1396   unify_trace_bound = 50 (formerly 25)
  1397   unify_search_bound = 60 (formerly 30)
  1398 
  1399 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1400 
  1401   a) On theory merge, the last set of code equations for a particular
  1402      constant is taken (in accordance with the policy applied by other
  1403      parts of the code generator framework).
  1404 
  1405   b) Code equations stemming from explicit declarations (e.g. code
  1406      attribute) gain priority over default code equations stemming
  1407      from definition, primrec, fun etc.
  1408 
  1409 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1410 
  1411 * Unified theorem tables for both code generators.  Thus [code
  1412 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1413 
  1414 * Command 'find_consts' searches for constants based on type and name
  1415 patterns, e.g.
  1416 
  1417     find_consts "_ => bool"
  1418 
  1419 By default, matching is against subtypes, but it may be restricted to
  1420 the whole type.  Searching by name is possible.  Multiple queries are
  1421 conjunctive and queries may be negated by prefixing them with a
  1422 hyphen:
  1423 
  1424     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1425 
  1426 * New 'find_theorems' criterion "solves" matches theorems that
  1427 directly solve the current goal (modulo higher-order unification).
  1428 
  1429 * Auto solve feature for main theorem statements: whenever a new goal
  1430 is stated, "find_theorems solves" is called; any theorems that could
  1431 solve the lemma directly are listed as part of the goal state.
  1432 Cf. associated options in Proof General Isabelle settings menu,
  1433 enabled by default, with reasonable timeout for pathological cases of
  1434 higher-order unification.
  1435 
  1436 
  1437 *** Document preparation ***
  1438 
  1439 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1440 demanding keyword 'by' and supporting the full method expression
  1441 syntax just like the Isar command 'by'.
  1442 
  1443 
  1444 *** HOL ***
  1445 
  1446 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1447 points Main and Complex_Main remain as before.
  1448 
  1449 * Logic image HOL-Plain provides a minimal HOL with the most important
  1450 tools available (inductive, datatype, primrec, ...).  This facilitates
  1451 experimentation and tool development.  Note that user applications
  1452 (and library theories) should never refer to anything below theory
  1453 Main, as before.
  1454 
  1455 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1456 experimentation due to shorter build times.
  1457 
  1458 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1459 were previously part of former HOL-Complex.  Entry point Hyperreal
  1460 remains valid, but theories formerly using Complex_Main should now use
  1461 new entry point Hypercomplex.
  1462 
  1463 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1464 Posix processes.  Avoids potentially expensive forking of the ML
  1465 process.  New thread-based implementation also works on non-Unix
  1466 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1467 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1468 commands are covered in the isar-ref manual.
  1469 
  1470 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1471 sledgehammer without local ATP installation (Vampire etc.). Other
  1472 provers may be included via suitable ML wrappers, see also
  1473 src/HOL/ATP_Linkup.thy.
  1474 
  1475 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1476 menu.
  1477 
  1478 * The metis method no longer fails because the theorem is too trivial
  1479 (contains the empty clause).
  1480 
  1481 * The metis method now fails in the usual manner, rather than raising
  1482 an exception, if it determines that it cannot prove the theorem.
  1483 
  1484 * Method "coherent" implements a prover for coherent logic (see also
  1485 src/Tools/coherent.ML).
  1486 
  1487 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1488 "undefined" is the right choice to replace "arbitrary", though
  1489 logically there is no difference.  INCOMPATIBILITY.
  1490 
  1491 * Command "value" now integrates different evaluation mechanisms.  The
  1492 result of the first successful evaluation mechanism is printed.  In
  1493 square brackets a particular named evaluation mechanisms may be
  1494 specified (currently, [SML], [code] or [nbe]).  See further
  1495 src/HOL/ex/Eval_Examples.thy.
  1496 
  1497 * Normalization by evaluation now allows non-leftlinear equations.
  1498 Declare with attribute [code nbe].
  1499 
  1500 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1501 as the structured Isar versions "cases" and "induct", cf. the
  1502 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1503 are now presented as a list of individual projections
  1504 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1505 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1506 rare situations a different rule is selected --- notably nested tuple
  1507 elimination instead of former prod.exhaust: use explicit (case_tac t
  1508 rule: prod.exhaust) here.
  1509 
  1510 * Attributes "cases", "induct", "coinduct" support "del" option.
  1511 
  1512 * Removed fact "case_split_thm", which duplicates "case_split".
  1513 
  1514 * The option datatype has been moved to a new theory Option.  Renamed
  1515 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1516 
  1517 * New predicate "strict_mono" classifies strict functions on partial
  1518 orders.  With strict functions on linear orders, reasoning about
  1519 (in)equalities is facilitated by theorems "strict_mono_eq",
  1520 "strict_mono_less_eq" and "strict_mono_less".
  1521 
  1522 * Some set operations are now proper qualified constants with
  1523 authentic syntax.  INCOMPATIBILITY:
  1524 
  1525     op Int ~>   Set.Int
  1526     op Un ~>    Set.Un
  1527     INTER ~>    Set.INTER
  1528     UNION ~>    Set.UNION
  1529     Inter ~>    Set.Inter
  1530     Union ~>    Set.Union
  1531     {} ~>       Set.empty
  1532     UNIV ~>     Set.UNIV
  1533 
  1534 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1535 theory Set.
  1536 
  1537 * Auxiliary class "itself" has disappeared -- classes without any
  1538 parameter are treated as expected by the 'class' command.
  1539 
  1540 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1541 
  1542 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1543 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1544 
  1545 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1546 method "approximation".  It proves formulas on real values by using
  1547 interval arithmetic.  In the formulas are also the transcendental
  1548 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1549 allowed. For examples see
  1550 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1551 
  1552 * Theory "Reflection" now resides in HOL/Library.
  1553 
  1554 * Entry point to Word library now simply named "Word".
  1555 INCOMPATIBILITY.
  1556 
  1557 * Made source layout more coherent with logical distribution
  1558 structure:
  1559 
  1560     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1561     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1562     src/HOL/Library/GCD.thy ~> src/HOL/
  1563     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1564     src/HOL/Library/Parity.thy ~> src/HOL/
  1565     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1566     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1567     src/HOL/Real/Lubs.thy ~> src/HOL/
  1568     src/HOL/Real/PReal.thy ~> src/HOL/
  1569     src/HOL/Real/Rational.thy ~> src/HOL/
  1570     src/HOL/Real/RComplete.thy ~> src/HOL/
  1571     src/HOL/Real/RealDef.thy ~> src/HOL/
  1572     src/HOL/Real/RealPow.thy ~> src/HOL/
  1573     src/HOL/Real/Real.thy ~> src/HOL/
  1574     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1575     src/HOL/Complex/Complex.thy ~> src/HOL/
  1576     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1577     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1578     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1579     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1580     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1581     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1582     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1583     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1584     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1585     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1586     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1587     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1588     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1589     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1590     src/HOL/Real/Float ~> src/HOL/Library/
  1591     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1592     src/HOL/Real/RealVector.thy ~> src/HOL/
  1593 
  1594     src/HOL/arith_data.ML ~> src/HOL/Tools
  1595     src/HOL/hologic.ML ~> src/HOL/Tools
  1596     src/HOL/simpdata.ML ~> src/HOL/Tools
  1597     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1598     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1599     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1600     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1601     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1602     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1603     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1604 
  1605     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1606     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1607     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1608     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1609     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1610     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1611 
  1612 * If methods "eval" and "evaluation" encounter a structured proof
  1613 state with !!/==>, only the conclusion is evaluated to True (if
  1614 possible), avoiding strange error messages.
  1615 
  1616 * Method "sizechange" automates termination proofs using (a
  1617 modification of) the size-change principle.  Requires SAT solver.  See
  1618 src/HOL/ex/Termination.thy for examples.
  1619 
  1620 * Simplifier: simproc for let expressions now unfolds if bound
  1621 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1622 
  1623 * Method "arith": Linear arithmetic now ignores all inequalities when
  1624 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1625 
  1626 * New attribute "arith" for facts that should always be used
  1627 automatically by arithmetic. It is intended to be used locally in
  1628 proofs, e.g.
  1629 
  1630   assumes [arith]: "x > 0"
  1631 
  1632 Global usage is discouraged because of possible performance impact.
  1633 
  1634 * New classes "top" and "bot" with corresponding operations "top" and
  1635 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1636 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1637 
  1638 * Changed definition lemma "less_fun_def" in order to provide an
  1639 instance for preorders on functions; use lemma "less_le" instead.
  1640 INCOMPATIBILITY.
  1641 
  1642 * Theory Orderings: class "wellorder" moved here, with explicit
  1643 induction rule "less_induct" as assumption.  For instantiation of
  1644 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1645 INCOMPATIBILITY.
  1646 
  1647 * Theory Orderings: added class "preorder" as superclass of "order".
  1648 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1649 etc. slightly changed.  Some theorems named order_class.* now named
  1650 preorder_class.*.
  1651 
  1652 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1653 "diag" to "Id_on".
  1654 
  1655 * Theory Finite_Set: added a new fold combinator of type
  1656 
  1657   ('a => 'b => 'b) => 'b => 'a set => 'b
  1658 
  1659 Occasionally this is more convenient than the old fold combinator
  1660 which is now defined in terms of the new one and renamed to
  1661 fold_image.
  1662 
  1663 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1664 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1665 extended with further lemmas!).  At the moment both still exist but
  1666 the former will disappear at some point.
  1667 
  1668 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1669 class recpower.  Type-specific simp rules for various recpower types
  1670 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1671 
  1672 rat_power_0    -> power_0
  1673 rat_power_Suc  -> power_Suc
  1674 realpow_0      -> power_0
  1675 realpow_Suc    -> power_Suc
  1676 complexpow_0   -> power_0
  1677 complexpow_Suc -> power_Suc
  1678 power_poly_0   -> power_0
  1679 power_poly_Suc -> power_Suc
  1680 
  1681 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1682 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1683 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1684 of lemmas from Divides has been generalized from nat to class
  1685 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1686 renames resulting from duplicate elimination:
  1687 
  1688     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1689     zero_dvd_iff ~>         dvd_0_left_iff
  1690     dvd_0 ~>                dvd_0_right
  1691     DIVISION_BY_ZERO_DIV ~> div_by_0
  1692     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1693     mult_div ~>             div_mult_self2_is_id
  1694     mult_mod ~>             mod_mult_self2_is_0
  1695 
  1696 * Theory IntDiv: removed many lemmas that are instances of class-based
  1697 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1698 rename old lemmas as follows:
  1699 
  1700 dvd_diff               -> nat_dvd_diff
  1701 dvd_zminus_iff         -> dvd_minus_iff
  1702 mod_add1_eq            -> mod_add_eq
  1703 mod_mult1_eq           -> mod_mult_right_eq
  1704 mod_mult1_eq'          -> mod_mult_left_eq
  1705 mod_mult_distrib_mod   -> mod_mult_eq
  1706 nat_mod_add_left_eq    -> mod_add_left_eq
  1707 nat_mod_add_right_eq   -> mod_add_right_eq
  1708 nat_mod_div_trivial    -> mod_div_trivial
  1709 nat_mod_mod_trivial    -> mod_mod_trivial
  1710 zdiv_zadd_self1        -> div_add_self1
  1711 zdiv_zadd_self2        -> div_add_self2
  1712 zdiv_zmult_self1       -> div_mult_self2_is_id
  1713 zdiv_zmult_self2       -> div_mult_self1_is_id
  1714 zdvd_triv_left         -> dvd_triv_left
  1715 zdvd_triv_right        -> dvd_triv_right
  1716 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1717 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1718 zmod_zadd_left_eq      -> mod_add_left_eq
  1719 zmod_zadd_right_eq     -> mod_add_right_eq
  1720 zmod_zadd_self1        -> mod_add_self1
  1721 zmod_zadd_self2        -> mod_add_self2
  1722 zmod_zadd1_eq          -> mod_add_eq
  1723 zmod_zdiff1_eq         -> mod_diff_eq
  1724 zmod_zdvd_zmod         -> mod_mod_cancel
  1725 zmod_zmod_cancel       -> mod_mod_cancel
  1726 zmod_zmult_self1       -> mod_mult_self2_is_0
  1727 zmod_zmult_self2       -> mod_mult_self1_is_0
  1728 zmod_1                 -> mod_by_1
  1729 zdiv_1                 -> div_by_1
  1730 zdvd_abs1              -> abs_dvd_iff
  1731 zdvd_abs2              -> dvd_abs_iff
  1732 zdvd_refl              -> dvd_refl
  1733 zdvd_trans             -> dvd_trans
  1734 zdvd_zadd              -> dvd_add
  1735 zdvd_zdiff             -> dvd_diff
  1736 zdvd_zminus_iff        -> dvd_minus_iff
  1737 zdvd_zminus2_iff       -> minus_dvd_iff
  1738 zdvd_zmultD            -> dvd_mult_right
  1739 zdvd_zmultD2           -> dvd_mult_left
  1740 zdvd_zmult_mono        -> mult_dvd_mono
  1741 zdvd_0_right           -> dvd_0_right
  1742 zdvd_0_left            -> dvd_0_left_iff
  1743 zdvd_1_left            -> one_dvd
  1744 zminus_dvd_iff         -> minus_dvd_iff
  1745 
  1746 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1747 
  1748 * The real numbers offer decimal input syntax: 12.34 is translated
  1749 into 1234/10^2. This translation is not reversed upon output.
  1750 
  1751 * Theory Library/Polynomial defines an abstract type 'a poly of
  1752 univariate polynomials with coefficients of type 'a.  In addition to
  1753 the standard ring operations, it also supports div and mod.  Code
  1754 generation is also supported, using list-style constructors.
  1755 
  1756 * Theory Library/Inner_Product defines a class of real_inner for real
  1757 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1758 => real.  Class real_inner is a subclass of real_normed_vector from
  1759 theory RealVector.
  1760 
  1761 * Theory Library/Product_Vector provides instances for the product
  1762 type 'a * 'b of several classes from RealVector and Inner_Product.
  1763 Definitions of addition, subtraction, scalar multiplication, norms,
  1764 and inner products are included.
  1765 
  1766 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1767 addition to the field operations, numerals and case syntax are also
  1768 supported.
  1769 
  1770 * Theory Library/Diagonalize provides constructive version of Cantor's
  1771 first diagonalization argument.
  1772 
  1773 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1774 zlcm (for int); carried together from various gcd/lcm developements in
  1775 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1776 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1777 may recover tupled syntax as follows:
  1778 
  1779     hide (open) const gcd
  1780     abbreviation gcd where
  1781       "gcd == (%(a, b). GCD.gcd a b)"
  1782     notation (output)
  1783       GCD.gcd ("gcd '(_, _')")
  1784 
  1785 The same works for lcm, zgcd, zlcm.
  1786 
  1787 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1788 instantiations for algebraic structures.  Removed some duplicate
  1789 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1790 
  1791 * ML antiquotation @{code} takes a constant as argument and generates
  1792 corresponding code in background and inserts name of the corresponding
  1793 resulting ML value/function/datatype constructor binding in place.
  1794 All occurrences of @{code} with a single ML block are generated
  1795 simultaneously.  Provides a generic and safe interface for
  1796 instrumentalizing code generation.  See
  1797 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1798 In future you ought to refrain from ad-hoc compiling generated SML
  1799 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1800 cannot refer to constants for which user-defined serializations are
  1801 set.  Refer to the corresponding ML counterpart directly in that
  1802 cases.
  1803 
  1804 * Command 'rep_datatype': instead of theorem names the command now
  1805 takes a list of terms denoting the constructors of the type to be
  1806 represented as datatype.  The characteristic theorems have to be
  1807 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1808 have disappeared in favour of existing ones:
  1809 
  1810     unit_induct                 ~> unit.induct
  1811     prod_induct                 ~> prod.induct
  1812     sum_induct                  ~> sum.induct
  1813     Suc_Suc_eq                  ~> nat.inject
  1814     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1815 
  1816 
  1817 *** HOL-Algebra ***
  1818 
  1819 * New locales for orders and lattices where the equivalence relation
  1820 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1821 locales use a record structure with field eq for the equivalence.
  1822 
  1823 * New theory of factorial domains.
  1824 
  1825 * Units_l_inv and Units_r_inv are now simp rules by default.
  1826 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1827 and/or r_inv will now also require deletion of these lemmas.
  1828 
  1829 * Renamed the following theorems, INCOMPATIBILITY:
  1830 
  1831 UpperD ~> Upper_memD
  1832 LowerD ~> Lower_memD
  1833 least_carrier ~> least_closed
  1834 greatest_carrier ~> greatest_closed
  1835 greatest_Lower_above ~> greatest_Lower_below
  1836 one_zero ~> carrier_one_zero
  1837 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1838 
  1839 
  1840 *** HOL-Nominal ***
  1841 
  1842 * Nominal datatypes can now contain type-variables.
  1843 
  1844 * Commands 'nominal_inductive' and 'equivariance' work with local
  1845 theory targets.
  1846 
  1847 * Nominal primrec can now works with local theory targets and its
  1848 specification syntax now conforms to the general format as seen in
  1849 'inductive' etc.
  1850 
  1851 * Method "perm_simp" honours the standard simplifier attributes
  1852 (no_asm), (no_asm_use) etc.
  1853 
  1854 * The new predicate #* is defined like freshness, except that on the
  1855 left hand side can be a set or list of atoms.
  1856 
  1857 * Experimental command 'nominal_inductive2' derives strong induction
  1858 principles for inductive definitions.  In contrast to
  1859 'nominal_inductive', which can only deal with a fixed number of
  1860 binders, it can deal with arbitrary expressions standing for sets of
  1861 atoms to be avoided.  The only inductive definition we have at the
  1862 moment that needs this generalisation is the typing rule for Lets in
  1863 the algorithm W:
  1864 
  1865  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1866  -----------------------------------------------------------------
  1867          Gamma |- Let x be t1 in t2 : T2
  1868 
  1869 In this rule one wants to avoid all the binders that are introduced by
  1870 "close Gamma T1".  We are looking for other examples where this
  1871 feature might be useful.  Please let us know.
  1872 
  1873 
  1874 *** HOLCF ***
  1875 
  1876 * Reimplemented the simplification procedure for proving continuity
  1877 subgoals.  The new simproc is extensible; users can declare additional
  1878 continuity introduction rules with the attribute [cont2cont].
  1879 
  1880 * The continuity simproc now uses a different introduction rule for
  1881 solving continuity subgoals on terms with lambda abstractions.  In
  1882 some rare cases the new simproc may fail to solve subgoals that the
  1883 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1884 Potential INCOMPATIBILITY.
  1885 
  1886 * Command 'fixrec': specification syntax now conforms to the general
  1887 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1888 examples.  INCOMPATIBILITY.
  1889 
  1890 
  1891 *** ZF ***
  1892 
  1893 * Proof of Zorn's Lemma for partial orders.
  1894 
  1895 
  1896 *** ML ***
  1897 
  1898 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1899 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1900 depends on multithreading, so timouts will not work before Poly/ML
  1901 5.2.1!
  1902 
  1903 * High-level support for concurrent ML programming, see
  1904 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1905 particularly convenient to organize independent functional
  1906 computations.  The concept of "synchronized variables" provides a
  1907 higher-order interface for components with shared state, avoiding the
  1908 delicate details of mutexes and condition variables.  (Requires
  1909 Poly/ML 5.2.1 or later.)
  1910 
  1911 * ML bindings produced via Isar commands are stored within the Isar
  1912 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1913 become thread-safe and work with undo as expected (concerning
  1914 top-level bindings, not side-effects on global references).
  1915 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1916 compiler at runtime; really global bindings need to be given outside a
  1917 theory.  (Requires Poly/ML 5.2 or later.)
  1918 
  1919 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1920 context.  Top-level ML bindings are stored within the proof context in
  1921 a purely sequential fashion, disregarding the nested proof structure.
  1922 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1923 proof.  (Requires Poly/ML 5.2 or later.)
  1924 
  1925 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1926 and Method.setup, as well as Isar commands 'attribute_setup' and
  1927 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1928 existing code accordingly, or use plain 'setup' together with old
  1929 Method.add_method.
  1930 
  1931 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1932 to 'a -> thm, while results are always tagged with an authentic oracle
  1933 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1934 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1935 accordingly.  Note that extra performance may be gained by producing
  1936 the cterm carefully, avoiding slow Thm.cterm_of.
  1937 
  1938 * Simplified interface for defining document antiquotations via
  1939 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1940 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1941 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1942 examples.
  1943 
  1944 * More systematic treatment of long names, abstract name bindings, and
  1945 name space operations.  Basic operations on qualified names have been
  1946 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1947 Long_Name.append.  Old type bstring has been mostly replaced by
  1948 abstract type binding (see structure Binding), which supports precise
  1949 qualification by packages and local theory targets, as well as proper
  1950 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1951 bstring values into Binding.name, or better pass through abstract
  1952 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1953 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1954 
  1955 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1956 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1957 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1958 
  1959 * Disposed old type and term read functions (Sign.read_def_typ,
  1960 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1961 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1962 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1963 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1964 resort for legacy applications.
  1965 
  1966 * Disposed old declarations, tactics, tactic combinators that refer to
  1967 the simpset or claset of an implicit theory (such as Addsimps,
  1968 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1969 embedded ML text, or local_simpset_of with a proper context passed as
  1970 explicit runtime argument.
  1971 
  1972 * Rules and tactics that read instantiations (read_instantiate,
  1973 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1974 context, which is required for parsing and type-checking.  Moreover,
  1975 the variables are specified as plain indexnames, not string encodings
  1976 thereof.  INCOMPATIBILITY.
  1977 
  1978 * Generic Toplevel.add_hook interface allows to analyze the result of
  1979 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1980 for theorem dependency output of transactions resulting in a new
  1981 theory state.
  1982 
  1983 * ML antiquotations: block-structured compilation context indicated by
  1984 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1985 
  1986   @{binding name}                         - basic name binding
  1987   @{let ?pat = term}                      - term abbreviation (HO matching)
  1988   @{note name = fact}                     - fact abbreviation
  1989   @{thm fact}                             - singleton fact (with attributes)
  1990   @{thms fact}                            - general fact (with attributes)
  1991   @{lemma prop by method}                 - singleton goal
  1992   @{lemma prop by meth1 meth2}            - singleton goal
  1993   @{lemma prop1 ... propN by method}      - general goal
  1994   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1995   @{lemma (open) ...}                     - open derivation
  1996 
  1997 
  1998 *** System ***
  1999 
  2000 * The Isabelle "emacs" tool provides a specific interface to invoke
  2001 Proof General / Emacs, with more explicit failure if that is not
  2002 installed (the old isabelle-interface script silently falls back on
  2003 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2004 installation location of the Proof General distribution.
  2005 
  2006 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2007 the Isabelle process into a JVM/Scala application.  See
  2008 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2009 process wrapper has been discontinued.)
  2010 
  2011 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2012 
  2013 * Various status messages (with exact source position information) are
  2014 emitted, if proper markup print mode is enabled.  This allows
  2015 user-interface components to provide detailed feedback on internal
  2016 prover operations.
  2017 
  2018 
  2019 
  2020 New in Isabelle2008 (June 2008)
  2021 -------------------------------
  2022 
  2023 *** General ***
  2024 
  2025 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2026 and updated, with formally checked references as hyperlinks.
  2027 
  2028 * Theory loader: use_thy (and similar operations) no longer set the
  2029 implicit ML context, which was occasionally hard to predict and in
  2030 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2031 provides a proper context already.
  2032 
  2033 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2034 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2035 'use' within a theory file will do the job.
  2036 
  2037 * Name space merge now observes canonical order, i.e. the second space
  2038 is inserted into the first one, while existing entries in the first
  2039 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2040 swap theory imports.
  2041 
  2042 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2043 INCOMPATIBILITY in identifier syntax etc.
  2044 
  2045 * Outer syntax: string tokens no longer admit escaped white space,
  2046 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2047 white space without escapes.
  2048 
  2049 * Outer syntax: string tokens may contain arbitrary character codes
  2050 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2051 "foo_bar".
  2052 
  2053 
  2054 *** Pure ***
  2055 
  2056 * Context-dependent token translations.  Default setup reverts locally
  2057 fixed variables, and adds hilite markup for undeclared frees.
  2058 
  2059 * Unused theorems can be found using the new command 'unused_thms'.
  2060 There are three ways of invoking it:
  2061 
  2062 (1) unused_thms
  2063      Only finds unused theorems in the current theory.
  2064 
  2065 (2) unused_thms thy_1 ... thy_n -
  2066      Finds unused theorems in the current theory and all of its ancestors,
  2067      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2068 
  2069 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2070      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2071      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2072      their ancestors.
  2073 
  2074 In order to increase the readability of the list produced by
  2075 unused_thms, theorems that have been created by a particular instance
  2076 of a theory command such as 'inductive' or 'function' are considered
  2077 to belong to the same "group", meaning that if at least one theorem in
  2078 this group is used, the other theorems in the same group are no longer
  2079 reported as unused.  Moreover, if all theorems in the group are
  2080 unused, only one theorem in the group is displayed.
  2081 
  2082 Note that proof objects have to be switched on in order for
  2083 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2084 usually the case when using Proof General with the default settings).
  2085 
  2086 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2087 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2088 duplicate fact bindings, or even accidental fact duplications.  Note
  2089 that tools may maintain dynamically scoped facts systematically, using
  2090 PureThy.add_thms_dynamic.
  2091 
  2092 * Command 'hide' now allows to hide from "fact" name space as well.
  2093 
  2094 * Eliminated destructive theorem database, simpset, claset, and
  2095 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2096 update of theories within ML code.
  2097 
  2098 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2099 INCOMPATIBILITY, object-logics depending on former Pure require
  2100 additional setup PureThy.old_appl_syntax_setup; object-logics
  2101 depending on former CPure need to refer to Pure.
  2102 
  2103 * Commands 'use' and 'ML' are now purely functional, operating on
  2104 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2105 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2106 INCOMPATIBILITY.
  2107 
  2108 * Command 'setup': discontinued implicit version with ML reference.
  2109 
  2110 * Instantiation target allows for simultaneous specification of class
  2111 instance operations together with an instantiation proof.
  2112 Type-checking phase allows to refer to class operations uniformly.
  2113 See src/HOL/Complex/Complex.thy for an Isar example and
  2114 src/HOL/Library/Eval.thy for an ML example.
  2115 
  2116 * Indexing of literal facts: be more serious about including only
  2117 facts from the visible specification/proof context, but not the
  2118 background context (locale etc.).  Affects `prop` notation and method
  2119 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2120 situations.
  2121 
  2122 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2123 "(open)" option, which used to expose internal bound variables to the
  2124 proof text.
  2125 
  2126 * Isar statements: removed obsolete case "rule_context".
  2127 INCOMPATIBILITY, better use explicit fixes/assumes.
  2128 
  2129 * Locale proofs: default proof step now includes 'unfold_locales';
  2130 hence 'proof' without argument may be used to unfold locale
  2131 predicates.
  2132 
  2133 
  2134 *** Document preparation ***
  2135 
  2136 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2137 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2138 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2139 spot); renamed link color from "darkblue" to "linkcolor" (default
  2140 value unchanged, can be redefined via \definecolor); no longer sets
  2141 "a4paper" option (unnecessary or even intrusive).
  2142 
  2143 * Antiquotation @{lemma A method} proves proposition A by the given
  2144 method (either a method name or a method name plus (optional) method
  2145 arguments in parentheses) and prints A just like @{prop A}.
  2146 
  2147 
  2148 *** HOL ***
  2149 
  2150 * New primrec package.  Specification syntax conforms in style to
  2151 definition/function/....  No separate induction rule is provided.  The
  2152 "primrec" command distinguishes old-style and new-style specifications
  2153 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2154 When adjusting theories, beware: constants stemming from new-style
  2155 primrec specifications have authentic syntax.
  2156 
  2157 * Metis prover is now an order of magnitude faster, and also works
  2158 with multithreading.
  2159 
  2160 * Metis: the maximum number of clauses that can be produced from a
  2161 theorem is now given by the attribute max_clauses.  Theorems that
  2162 exceed this number are ignored, with a warning printed.
  2163 
  2164 * Sledgehammer no longer produces structured proofs by default. To
  2165 enable, declare [[sledgehammer_full = true]].  Attributes
  2166 reconstruction_modulus, reconstruction_sorts renamed
  2167 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2168 
  2169 * Method "induct_scheme" derives user-specified induction rules
  2170 from well-founded induction and completeness of patterns. This factors
  2171 out some operations that are done internally by the function package
  2172 and makes them available separately.  See
  2173 src/HOL/ex/Induction_Scheme.thy for examples.
  2174 
  2175 * More flexible generation of measure functions for termination
  2176 proofs: Measure functions can be declared by proving a rule of the
  2177 form "is_measure f" and giving it the [measure_function] attribute.
  2178 The "is_measure" predicate is logically meaningless (always true), and
  2179 just guides the heuristic.  To find suitable measure functions, the
  2180 termination prover sets up the goal "is_measure ?f" of the appropriate
  2181 type and generates all solutions by prolog-style backwards proof using
  2182 the declared rules.
  2183 
  2184 This setup also deals with rules like 
  2185 
  2186   "is_measure f ==> is_measure (list_size f)"
  2187 
  2188 which accommodates nested datatypes that recurse through lists.
  2189 Similar rules are predeclared for products and option types.
  2190 
  2191 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2192 
  2193   INCOMPATIBILITIES:
  2194 
  2195   - Definitions of overloaded constants on sets have to be replaced by
  2196     definitions on => and bool.
  2197 
  2198   - Some definitions of overloaded operators on sets can now be proved
  2199     using the definitions of the operators on => and bool.  Therefore,
  2200     the following theorems have been renamed:
  2201 
  2202       subset_def   -> subset_eq
  2203       psubset_def  -> psubset_eq
  2204       set_diff_def -> set_diff_eq
  2205       Compl_def    -> Compl_eq
  2206       Sup_set_def  -> Sup_set_eq
  2207       Inf_set_def  -> Inf_set_eq
  2208       sup_set_def  -> sup_set_eq
  2209       inf_set_def  -> inf_set_eq
  2210 
  2211   - Due to the incompleteness of the HO unification algorithm, some
  2212     rules such as subst may require manual instantiation, if some of
  2213     the unknowns in the rule is a set.
  2214 
  2215   - Higher order unification and forward proofs:
  2216     The proof pattern
  2217 
  2218       have "P (S::'a set)" <...>
  2219       then have "EX S. P S" ..
  2220 
  2221     no longer works (due to the incompleteness of the HO unification
  2222     algorithm) and must be replaced by the pattern
  2223 
  2224       have "EX S. P S"
  2225       proof
  2226         show "P S" <...>
  2227       qed
  2228 
  2229   - Calculational reasoning with subst (or similar rules):
  2230     The proof pattern
  2231 
  2232       have "P (S::'a set)" <...>
  2233       also have "S = T" <...>
  2234       finally have "P T" .
  2235 
  2236     no longer works (for similar reasons as the previous example) and
  2237     must be replaced by something like
  2238 
  2239       have "P (S::'a set)" <...>
  2240       moreover have "S = T" <...>
  2241       ultimately have "P T" by simp
  2242 
  2243   - Tactics or packages written in ML code:
  2244     Code performing pattern matching on types via
  2245 
  2246       Type ("set", [T]) => ...
  2247 
  2248     must be rewritten. Moreover, functions like strip_type or
  2249     binder_types no longer return the right value when applied to a
  2250     type of the form
  2251 
  2252       T1 => ... => Tn => U => bool
  2253 
  2254     rather than
  2255 
  2256       T1 => ... => Tn => U set
  2257 
  2258 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2259 Wellfounded_Relations to theory Wellfounded.
  2260 
  2261 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2262 
  2263 * Class finite no longer treats UNIV as class parameter.  Use class
  2264 enum from theory Library/Enum instead to achieve a similar effect.
  2265 INCOMPATIBILITY.
  2266 
  2267 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2268 and "Cons".  INCOMPATIBILITY.
  2269 
  2270 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2271 Potential INCOMPATIBILITY.
  2272 
  2273 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2274 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2275 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2276 
  2277 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2278 the same name in theory Orderings:
  2279 
  2280   less_trans
  2281   less_linear
  2282   le_imp_less_or_eq
  2283   le_less_trans
  2284   less_le_trans
  2285   less_not_sym
  2286   less_asym
  2287 
  2288 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2289 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2290 and different variable names.
  2291 
  2292 * Library/Option_ord.thy: Canonical order on option type.
  2293 
  2294 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2295 finite maps.
  2296 
  2297 * Library/Countable.thy: Type class for countable types.
  2298 
  2299 * Theory Int: The representation of numerals has changed.  The infix
  2300 operator BIT and the bit datatype with constructors B0 and B1 have
  2301 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2302 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2303 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2304 accordingly.
  2305 
  2306 * Theory Nat: definition of <= and < on natural numbers no longer
  2307 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2308 le_def and less_def have disappeared.  Consider lemmas not_less
  2309 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2310 
  2311 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2312 (whose purpose mainly is for various fold_set functionals) have been
  2313 abandoned in favor of the existing algebraic classes
  2314 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2315 lower_semilattice (resp. upper_semilattice) and linorder.
  2316 INCOMPATIBILITY.
  2317 
  2318 * Theory Transitive_Closure: induct and cases rules now declare proper
  2319 case_names ("base" and "step").  INCOMPATIBILITY.
  2320 
  2321 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2322 lattices.  The form set-specific version is available as
  2323 Inductive.lfp_ordinal_induct_set.
  2324 
  2325 * Renamed theorems "power.simps" to "power_int.simps".
  2326 INCOMPATIBILITY.
  2327 
  2328 * Class semiring_div provides basic abstract properties of semirings
  2329 with division and modulo operations.  Subsumes former class dvd_mod.
  2330 
  2331 * Merged theories IntDef, Numeral and IntArith into unified theory
  2332 Int.  INCOMPATIBILITY.
  2333 
  2334 * Theory Library/Code_Index: type "index" now represents natural
  2335 numbers rather than integers.  INCOMPATIBILITY.
  2336 
  2337 * New class "uminus" with operation "uminus" (split of from class
  2338 "minus" which now only has operation "minus", binary).
  2339 INCOMPATIBILITY.
  2340 
  2341 * Constants "card", "internal_split", "option_map" now with authentic
  2342 syntax.  INCOMPATIBILITY.
  2343 
  2344 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2345 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2346 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2347 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2348 Sup_set_def, le_def, less_def, option_map_def now with object
  2349 equality.  INCOMPATIBILITY.
  2350 
  2351 * Records. Removed K_record, and replaced it by pure lambda term
  2352 %x. c. The simplifier setup is now more robust against eta expansion.
  2353 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2354 
  2355 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2356 
  2357 * Library/ListVector: new theory of arithmetic vector operations.
  2358 
  2359 * Library/Order_Relation: new theory of various orderings as sets of
  2360 pairs.  Defines preorders, partial orders, linear orders and
  2361 well-orders on sets and on types.
  2362 
  2363 
  2364 *** ZF ***
  2365 
  2366 * Renamed some theories to allow to loading both ZF and HOL in the
  2367 same session:
  2368 
  2369   Datatype  -> Datatype_ZF
  2370   Inductive -> Inductive_ZF
  2371   Int       -> Int_ZF
  2372   IntDiv    -> IntDiv_ZF
  2373   Nat       -> Nat_ZF
  2374   List      -> List_ZF
  2375   Main      -> Main_ZF
  2376 
  2377 INCOMPATIBILITY: ZF theories that import individual theories below
  2378 Main might need to be adapted.  Regular theory Main is still
  2379 available, as trivial extension of Main_ZF.
  2380 
  2381 
  2382 *** ML ***
  2383 
  2384 * ML within Isar: antiquotation @{const name} or @{const
  2385 name(typargs)} produces statically-checked Const term.
  2386 
  2387 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2388 (of the same name).  Removed obsolete print command.
  2389 
  2390 * Removed obsolete "use_legacy_bindings" function.
  2391 
  2392 * The ``print mode'' is now a thread-local value derived from a global
  2393 template (the former print_mode reference), thus access becomes
  2394 non-critical.  The global print_mode reference is for session
  2395 management only; user-code should use print_mode_value,
  2396 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2397 
  2398 * Functions system/system_out provide a robust way to invoke external
  2399 shell commands, with propagation of interrupts (requires Poly/ML
  2400 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2401 
  2402 
  2403 *** System ***
  2404 
  2405 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2406 in accordance with Proof General 3.7, which prefers GNU emacs.
  2407 
  2408 * isatool tty runs Isabelle process with plain tty interaction;
  2409 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2410 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2411 
  2412 * isatool browser now works with Cygwin as well, using general
  2413 "javapath" function defined in Isabelle process environment.
  2414 
  2415 * YXML notation provides a simple and efficient alternative to
  2416 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2417 isatool yxml as described in the Isabelle system manual.
  2418 
  2419 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2420 provides general wrapper for managing an Isabelle process in a robust
  2421 fashion, with ``cooked'' output from stdin/stderr.
  2422 
  2423 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2424 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2425 
  2426 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2427 way of changing the user's settings is via
  2428 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2429 script.
  2430 
  2431 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2432 cores of the underlying machine, which is a good starting point for
  2433 optimal performance tuning.  The corresponding usedir option -M allows
  2434 "max" as an alias for "0".  WARNING: does not work on certain versions
  2435 of Mac OS (with Poly/ML 5.1).
  2436 
  2437 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2438 adverse effect of Isabelle flooding interactive front-ends (notably
  2439 ProofGeneral / XEmacs).
  2440 
  2441 
  2442 
  2443 New in Isabelle2007 (November 2007)
  2444 -----------------------------------
  2445 
  2446 *** General ***
  2447 
  2448 * More uniform information about legacy features, notably a
  2449 warning/error of "Legacy feature: ...", depending on the state of the
  2450 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2451 legacy features will disappear eventually.
  2452 
  2453 * Theory syntax: the header format ``theory A = B + C:'' has been
  2454 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2455 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2456 
  2457 * Theory syntax: the old non-Isar theory file format has been
  2458 discontinued altogether.  Note that ML proof scripts may still be used
  2459 with Isar theories; migration is usually quite simple with the ML
  2460 function use_legacy_bindings.  INCOMPATIBILITY.
  2461 
  2462 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2463 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2464 quotes.
  2465 
  2466 * Theory loader: be more serious about observing the static theory
  2467 header specifications (including optional directories), but not the
  2468 accidental file locations of previously successful loads.  The strict
  2469 update policy of former update_thy is now already performed by
  2470 use_thy, so the former has been removed; use_thys updates several
  2471 theories simultaneously, just as 'imports' within a theory header
  2472 specification, but without merging the results.  Potential
  2473 INCOMPATIBILITY: may need to refine theory headers and commands
  2474 ROOT.ML which depend on load order.
  2475 
  2476 * Theory loader: optional support for content-based file
  2477 identification, instead of the traditional scheme of full physical
  2478 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2479 (cf. the system manual).  The new scheme allows to work with
  2480 non-finished theories in persistent session images, such that source
  2481 files may be moved later on without requiring reloads.
  2482 
  2483 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2484 file (with the same base name as the theory) are considered a legacy
  2485 feature, which will disappear eventually. Even now, the theory loader
  2486 no longer maintains dependencies on such files.
  2487 
  2488 * Syntax: the scope for resolving ambiguities via type-inference is
  2489 now limited to individual terms, instead of whole simultaneous
  2490 specifications as before. This greatly reduces the complexity of the
  2491 syntax module and improves flexibility by separating parsing and
  2492 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2493 'fixes' etc.) are required in rare situations.
  2494 
  2495 * Syntax: constants introduced by new-style packages ('definition',
  2496 'abbreviation' etc.) are passed through the syntax module in
  2497 ``authentic mode''. This means that associated mixfix annotations
  2498 really stick to such constants, independently of potential name space
  2499 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2500 trees are represented slightly differently, may need to adapt syntax
  2501 translations accordingly. Use CONST marker in 'translations' and
  2502 @{const_syntax} antiquotation in 'parse_translation' etc.
  2503 
  2504 * Legacy goal package: reduced interface to the bare minimum required
  2505 to keep existing proof scripts running.  Most other user-level
  2506 functions are now part of the OldGoals structure, which is *not* open
  2507 by default (consider isatool expandshort before open OldGoals).
  2508 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2509 these tend to cause confusion about the actual goal (!) context being
  2510 used here, which is not necessarily the same as the_context().
  2511 
  2512 * Command 'find_theorems': supports "*" wild-card in "name:"
  2513 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2514 support a specific search form (see ProofGeneral/CHANGES).
  2515 
  2516 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2517 by default, which means that "prems" (and also "fixed variables") are
  2518 suppressed from proof state output.  Note that the ProofGeneral
  2519 settings mechanism allows to change and save options persistently, but
  2520 older versions of Isabelle will fail to start up if a negative prems
  2521 limit is imposed.
  2522 
  2523 * Local theory targets may be specified by non-nested blocks of
  2524 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2525 contain definitions, theorems etc., including any derived mechanism
  2526 that has been implemented on top of these primitives.  This concept
  2527 generalizes the existing ``theorem (in ...)'' towards more versatility
  2528 and scalability.
  2529 
  2530 * Proof General interface: proper undo of final 'end' command;
  2531 discontinued Isabelle/classic mode (ML proof scripts).
  2532 
  2533 
  2534 *** Document preparation ***
  2535 
  2536 * Added antiquotation @{theory name} which prints the given name,
  2537 after checking that it refers to a valid ancestor theory in the
  2538 current context.
  2539 
  2540 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2541 check the given source text as ML type/structure, printing verbatim.
  2542 
  2543 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2544 "c args == rhs" given in the current context.  (Any number of
  2545 arguments may be given on the LHS.)
  2546 
  2547 
  2548 *** Pure ***
  2549 
  2550 * The 'class' package offers a combination of axclass and locale to
  2551 achieve Haskell-like type classes in Isabelle.  Definitions and
  2552 theorems within a class context produce both relative results (with
  2553 implicit parameters according to the locale context), and polymorphic
  2554 constants with qualified polymorphism (according to the class
  2555 context).  Within the body context of a 'class' target, a separate
  2556 syntax layer ("user space type system") takes care of converting
  2557 between global polymorphic consts and internal locale representation.
  2558 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2559 "isatool doc classes" provides a tutorial.
  2560 
  2561 * Generic code generator framework allows to generate executable
  2562 code for ML and Haskell (including Isabelle classes).  A short usage
  2563 sketch:
  2564 
  2565     internal compilation:
  2566         export_code <list of constants (term syntax)> in SML
  2567     writing SML code to a file:
  2568         export_code <list of constants (term syntax)> in SML <filename>
  2569     writing OCaml code to a file:
  2570         export_code <list of constants (term syntax)> in OCaml <filename>
  2571     writing Haskell code to a bunch of files:
  2572         export_code <list of constants (term syntax)> in Haskell <filename>
  2573 
  2574     evaluating closed propositions to True/False using code generation:
  2575         method ``eval''
  2576 
  2577 Reasonable default setup of framework in HOL.
  2578 
  2579 Theorem attributs for selecting and transforming function equations theorems:
  2580 
  2581     [code fun]:        select a theorem as function equation for a specific constant
  2582     [code fun del]:    deselect a theorem as function equation for a specific constant
  2583     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2584     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2585 
  2586 User-defined serializations (target in {SML, OCaml, Haskell}):
  2587 
  2588     code_const <and-list of constants (term syntax)>
  2589       {(target) <and-list of const target syntax>}+
  2590 
  2591     code_type <and-list of type constructors>
  2592       {(target) <and-list of type target syntax>}+
  2593 
  2594     code_instance <and-list of instances>
  2595       {(target)}+
  2596         where instance ::= <type constructor> :: <class>
  2597 
  2598     code_class <and_list of classes>
  2599       {(target) <and-list of class target syntax>}+
  2600         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2601 
  2602 code_instance and code_class only are effective to target Haskell.
  2603 
  2604 For example usage see src/HOL/ex/Codegenerator.thy and
  2605 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2606 generation from Isabelle/HOL theories is available via "isatool doc
  2607 codegen".
  2608 
  2609 * Code generator: consts in 'consts_code' Isar commands are now
  2610 referred to by usual term syntax (including optional type
  2611 annotations).
  2612 
  2613 * Command 'no_translations' removes translation rules from theory
  2614 syntax.
  2615 
  2616 * Overloaded definitions are now actually checked for acyclic
  2617 dependencies.  The overloading scheme is slightly more general than
  2618 that of Haskell98, although Isabelle does not demand an exact
  2619 correspondence to type class and instance declarations.
  2620 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2621 exotic versions of overloading -- at the discretion of the user!
  2622 
  2623 Polymorphic constants are represented via type arguments, i.e. the
  2624 instantiation that matches an instance against the most general
  2625 declaration given in the signature.  For example, with the declaration
  2626 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2627 as c(nat).  Overloading is essentially simultaneous structural
  2628 recursion over such type arguments.  Incomplete specification patterns
  2629 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2630 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2631 Command 'print_theory' outputs the normalized system of recursive
  2632 equations, see section "definitions".
  2633 
  2634 * Configuration options are maintained within the theory or proof
  2635 context (with name and type bool/int/string), providing a very simple
  2636 interface to a poor-man's version of general context data.  Tools may
  2637 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2638 these values using Config.get etc.  Users may change options via an
  2639 associated attribute of the same name.  This form of context
  2640 declaration works particularly well with commands 'declare' or
  2641 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2642 very easy to avoid global references, which would not observe Isar
  2643 toplevel undo/redo and fail to work with multithreading.
  2644 
  2645 Various global ML references of Pure and HOL have been turned into
  2646 configuration options:
  2647 
  2648   Unify.search_bound		unify_search_bound
  2649   Unify.trace_bound		unify_trace_bound
  2650   Unify.trace_simp		unify_trace_simp
  2651   Unify.trace_types		unify_trace_types
  2652   Simplifier.simp_depth_limit	simp_depth_limit
  2653   Blast.depth_limit		blast_depth_limit
  2654   DatatypeProp.dtK		datatype_distinctness_limit
  2655   fast_arith_neq_limit  	fast_arith_neq_limit
  2656   fast_arith_split_limit	fast_arith_split_limit
  2657 
  2658 * Named collections of theorems may be easily installed as context
  2659 data using the functor NamedThmsFun (see also
  2660 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2661 attributes; there is also a toplevel print command.  This facility is
  2662 just a common case of general context data, which is the preferred way
  2663 for anything more complex than just a list of facts in canonical
  2664 order.
  2665 
  2666 * Isar: command 'declaration' augments a local theory by generic
  2667 declaration functions written in ML.  This enables arbitrary content
  2668 being added to the context, depending on a morphism that tells the
  2669 difference of the original declaration context wrt. the application
  2670 context encountered later on.
  2671 
  2672 * Isar: proper interfaces for simplification procedures.  Command
  2673 'simproc_setup' declares named simprocs (with match patterns, and body
  2674 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2675 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2676 
  2677 * Isar: an extra pair of brackets around attribute declarations
  2678 abbreviates a theorem reference involving an internal dummy fact,
  2679 which will be ignored later --- only the effect of the attribute on
  2680 the background context will persist.  This form of in-place
  2681 declarations is particularly useful with commands like 'declare' and
  2682 'using', for example ``have A using [[simproc a]] by simp''.
  2683 
  2684 * Isar: method "assumption" (and implicit closing of subproofs) now
  2685 takes simple non-atomic goal assumptions into account: after applying
  2686 an assumption as a rule the resulting subgoals are solved by atomic
  2687 assumption steps.  This is particularly useful to finish 'obtain'
  2688 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2689 without referring to the original premise "!!x. P x ==> thesis" in the
  2690 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2691 more permissive.
  2692 
  2693 * Isar: implicit use of prems from the Isar proof context is
  2694 considered a legacy feature.  Common applications like ``have A .''
  2695 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2696 referencing facts explicitly here improves readability and
  2697 maintainability of proof texts.
  2698 
  2699 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2700 the obtained context from the course of reasoning!  For example:
  2701 
  2702   assume "EX x y. A x & B y"   -- "any previous fact"
  2703   then guess x and y by clarify
  2704 
  2705 This technique is potentially adventurous, depending on the facts and
  2706 proof tools being involved here.
  2707 
  2708 * Isar: known facts from the proof context may be specified as literal
  2709 propositions, using ASCII back-quote syntax.  This works wherever
  2710 named facts used to be allowed so far, in proof commands, proof
  2711 methods, attributes etc.  Literal facts are retrieved from the context
  2712 according to unification of type and term parameters.  For example,
  2713 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2714 theorems in the current context, then these are valid literal facts:
  2715 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2716 
  2717 There is also a proof method "fact" which does the same composition
  2718 for explicit goal states, e.g. the following proof texts coincide with
  2719 certain special cases of literal facts:
  2720 
  2721   have "A" by fact                 ==  note `A`
  2722   have "A ==> B" by fact           ==  note `A ==> B`
  2723   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2724   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2725 
  2726 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2727 outer syntax.  Thus symbolic identifiers may be used without
  2728 additional white space in declarations like this: ``assume *: A''.
  2729 
  2730 * Isar: 'print_facts' prints all local facts of the current context,
  2731 both named and unnamed ones.
  2732 
  2733 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2734 
  2735   def x == "t" and y == "u"
  2736 
  2737 * Isar: added command 'unfolding', which is structurally similar to
  2738 'using', but affects both the goal state and facts by unfolding given
  2739 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2740 'unfolded' attribute may be replaced by first-class proof text.
  2741 
  2742 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2743 and command 'unfolding' now all support object-level equalities
  2744 (potentially conditional).  The underlying notion of rewrite rule is
  2745 analogous to the 'rule_format' attribute, but *not* that of the
  2746 Simplifier (which is usually more generous).
  2747 
  2748 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2749 premises of a theorem by n. Useful in conjunction with drule.
  2750 
  2751 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2752 method expression within a sandbox consisting of the first N
  2753 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2754 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2755 simplifies all new goals that emerge from applying rule foo to the
  2756 originally first one.
  2757 
  2758 * Isar: schematic goals are no longer restricted to higher-order
  2759 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2760 expected.
  2761 
  2762 * Isar: the conclusion of a long theorem statement is now either
  2763 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2764 (essentially a disjunction of cases with local parameters and
  2765 assumptions).  The latter allows to express general elimination rules
  2766 adequately; in this notation common elimination rules look like this:
  2767 
  2768   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2769     assumes "EX x. P x"
  2770     obtains x where "P x"
  2771 
  2772   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2773     assumes "A & B"
  2774     obtains A and B
  2775 
  2776   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2777     assumes "A | B"
  2778     obtains
  2779       A
  2780     | B
  2781 
  2782 The subsequent classical rules even refer to the formal "thesis"
  2783 explicitly:
  2784 
  2785   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2786     obtains "~ thesis"
  2787 
  2788   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2789     obtains "thesis ==> something"
  2790 
  2791 The actual proof of an 'obtains' statement is analogous to that of the
  2792 Isar proof element 'obtain', only that there may be several cases.
  2793 Optional case names may be specified in parentheses; these will be
  2794 available both in the present proof and as annotations in the
  2795 resulting rule, for later use with the 'cases' method (cf. attribute
  2796 case_names).
  2797 
  2798 * Isar: the assumptions of a long theorem statement are available as
  2799 "assms" fact in the proof context.  This is more appropriate than the
  2800 (historical) "prems", which refers to all assumptions of the current
  2801 context, including those from the target locale, proof body etc.
  2802 
  2803 * Isar: 'print_statement' prints theorems from the current theory or
  2804 proof context in long statement form, according to the syntax of a
  2805 top-level lemma.
  2806 
  2807 * Isar: 'obtain' takes an optional case name for the local context
  2808 introduction rule (default "that").
  2809 
  2810 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2811 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2812 to occur.
  2813 
  2814 * Pure: syntax "CONST name" produces a fully internalized constant
  2815 according to the current context.  This is particularly useful for
  2816 syntax translations that should refer to internal constant
  2817 representations independently of name spaces.
  2818 
  2819 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2820 instead of "FOO ". This allows multiple binder declarations to coexist
  2821 in the same context.  INCOMPATIBILITY.
  2822 
  2823 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2824 primitive that also works in a locale context (both for constants and
  2825 fixed variables). Type declaration and internal syntactic representation
  2826 of given constants retrieved from the context. Likewise, the
  2827 'no_notation' command allows to remove given syntax annotations from the
  2828 current context.
  2829 
  2830 * Isar/locales: new derived specification elements 'axiomatization',
  2831 'definition', 'abbreviation', which support type-inference, admit
  2832 object-level specifications (equality, equivalence).  See also the
  2833 isar-ref manual.  Examples:
  2834 
  2835   axiomatization
  2836     eq  (infix "===" 50) where
  2837     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2838 
  2839   definition "f x y = x + y + 1"
  2840   definition g where "g x = f x x"
  2841 
  2842   abbreviation
  2843     neq  (infix "=!=" 50) where
  2844     "x =!= y == ~ (x === y)"
  2845 
  2846 These specifications may be also used in a locale context.  Then the
  2847 constants being introduced depend on certain fixed parameters, and the
  2848 constant name is qualified by the locale base name.  An internal
  2849 abbreviation takes care for convenient input and output, making the
  2850 parameters implicit and using the original short name.  See also
  2851 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2852 entities from a monomorphic theory.
  2853 
  2854 Presently, abbreviations are only available 'in' a target locale, but
  2855 not inherited by general import expressions.  Also note that
  2856 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2857 'translations' in common applications.  The "no_abbrevs" print mode
  2858 prevents folding of abbreviations in term output.
  2859 
  2860 Concrete syntax is attached to specified constants in internal form,
  2861 independently of name spaces.  The parse tree representation is
  2862 slightly different -- use 'notation' instead of raw 'syntax', and
  2863 'translations' with explicit "CONST" markup to accommodate this.
  2864 
  2865 * Pure/Isar: unified syntax for new-style specification mechanisms
  2866 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2867 full type inference and dummy patterns ("_").  For example:
  2868 
  2869   definition "K x _ = x"
  2870 
  2871   inductive conj for A B
  2872   where "A ==> B ==> conj A B"
  2873 
  2874 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2875 the current context.  Print mode "no_abbrevs" prevents inversion of
  2876 abbreviations on output.
  2877 
  2878 * Isar/locales: improved parameter handling: use of locales "var" and
  2879 "struct" no longer necessary; - parameter renamings are no longer
  2880 required to be injective.  For example, this allows to define
  2881 endomorphisms as locale endom = homom mult mult h.
  2882 
  2883 * Isar/locales: changed the way locales with predicates are defined.
  2884 Instead of accumulating the specification, the imported expression is
  2885 now an interpretation.  INCOMPATIBILITY: different normal form of
  2886 locale expressions.  In particular, in interpretations of locales with
  2887 predicates, goals repesenting already interpreted fragments are not
  2888 removed automatically.  Use methods `intro_locales' and
  2889 `unfold_locales'; see below.
  2890 
  2891 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2892 provide backward reasoning on locales predicates.  The methods are
  2893 aware of interpretations and discharge corresponding goals.
  2894 `intro_locales' is less aggressive then `unfold_locales' and does not
  2895 unfold predicates to assumptions.
  2896 
  2897 * Isar/locales: the order in which locale fragments are accumulated
  2898 has changed.  This enables to override declarations from fragments due
  2899 to interpretations -- for example, unwanted simp rules.
  2900 
  2901 * Isar/locales: interpretation in theories and proof contexts has been
  2902 extended.  One may now specify (and prove) equations, which are
  2903 unfolded in interpreted theorems.  This is useful for replacing
  2904 defined concepts (constants depending on locale parameters) by
  2905 concepts already existing in the target context.  Example:
  2906 
  2907   interpretation partial_order ["op <= :: [int, int] => bool"]
  2908     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2909 
  2910 Typically, the constant `partial_order.less' is created by a
  2911 definition specification element in the context of locale
  2912 partial_order.
  2913 
  2914 * Method "induct": improved internal context management to support
  2915 local fixes and defines on-the-fly. Thus explicit meta-level
  2916 connectives !!  and ==> are rarely required anymore in inductive goals
  2917 (using object-logic connectives for this purpose has been long
  2918 obsolete anyway). Common proof patterns are explained in
  2919 src/HOL/Induct/Common_Patterns.thy, see also
  2920 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2921 examples.
  2922 
  2923 * Method "induct": improved handling of simultaneous goals. Instead of
  2924 introducing object-level conjunction, the statement is now split into
  2925 several conclusions, while the corresponding symbolic cases are nested
  2926 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2927 see src/HOL/Induct/Common_Patterns.thy, for example.
  2928 
  2929 * Method "induct": mutual induction rules are now specified as a list
  2930 of rule sharing the same induction cases. HOL packages usually provide
  2931 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2932 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2933 mutual induction rules differently, i.e. like this:
  2934 
  2935   (induct rule: foo_bar.inducts)
  2936   (induct set: foo bar)
  2937   (induct pred: foo bar)
  2938   (induct type: foo bar)
  2939 
  2940 The ML function ProjectRule.projections turns old-style rules into the
  2941 new format.
  2942 
  2943 * Method "coinduct": dual of induction, see
  2944 src/HOL/Library/Coinductive_List.thy for various examples.
  2945 
  2946 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2947 considered a legacy feature.
  2948 
  2949 * Attribute "symmetric" produces result with standardized schematic
  2950 variables (index 0).  Potential INCOMPATIBILITY.
  2951 
  2952 * Simplifier: by default the simplifier trace only shows top level
  2953 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2954 default. Thus there is less danger of being flooded by the trace. The
  2955 trace indicates where parts have been suppressed.
  2956   
  2957 * Provers/classical: removed obsolete classical version of elim_format
  2958 attribute; classical elim/dest rules are now treated uniformly when
  2959 manipulating the claset.
  2960 
  2961 * Provers/classical: stricter checks to ensure that supplied intro,
  2962 dest and elim rules are well-formed; dest and elim rules must have at
  2963 least one premise.
  2964 
  2965 * Provers/classical: attributes dest/elim/intro take an optional
  2966 weight argument for the rule (just as the Pure versions).  Weights are
  2967 ignored by automated tools, but determine the search order of single
  2968 rule steps.
  2969 
  2970 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2971 where the body does not mention the bound variable.  Note that dummy
  2972 patterns implicitly depend on their context of bounds, which makes
  2973 "{_. _}" match any set comprehension as expected.  Potential
  2974 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2975 constant "_idtdummy" in the binding position.
  2976 
  2977 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2978 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2979 for example "A -> B" => "Pi A (%_. B)".
  2980 
  2981 * Pure: 'class_deps' command visualizes the subclass relation, using
  2982 the graph browser tool.
  2983 
  2984 * Pure: 'print_theory' now suppresses certain internal declarations by
  2985 default; use '!' option for full details.
  2986 
  2987 
  2988 *** HOL ***
  2989 
  2990 * Method "metis" proves goals by applying the Metis general-purpose
  2991 resolution prover (see also http://gilith.com/software/metis/).
  2992 Examples are in the directory MetisExamples.  WARNING: the
  2993 Isabelle/HOL-Metis integration does not yet work properly with
  2994 multi-threading.
  2995   
  2996 * Command 'sledgehammer' invokes external automatic theorem provers as
  2997 background processes.  It generates calls to the "metis" method if
  2998 successful. These can be pasted into the proof.  Users do not have to
  2999 wait for the automatic provers to return.  WARNING: does not really
  3000 work with multi-threading.
  3001 
  3002 * New "auto_quickcheck" feature tests outermost goal statements for
  3003 potential counter-examples.  Controlled by ML references
  3004 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3005 5000 milliseconds).  Fails silently if statements is outside of
  3006 executable fragment, or any other codgenerator problem occurs.
  3007 
  3008 * New constant "undefined" with axiom "undefined x = undefined".
  3009 
  3010 * Added class "HOL.eq", allowing for code generation with polymorphic
  3011 equality.
  3012 
  3013 * Some renaming of class constants due to canonical name prefixing in
  3014 the new 'class' package:
  3015 
  3016     HOL.abs ~> HOL.abs_class.abs
  3017     HOL.divide ~> HOL.divide_class.divide
  3018     0 ~> HOL.zero_class.zero
  3019     1 ~> HOL.one_class.one
  3020     op + ~> HOL.plus_class.plus
  3021     op - ~> HOL.minus_class.minus
  3022     uminus ~> HOL.minus_class.uminus
  3023     op * ~> HOL.times_class.times
  3024     op < ~> HOL.ord_class.less
  3025     op <= > HOL.ord_class.less_eq
  3026     Nat.power ~> Power.power_class.power
  3027     Nat.size ~> Nat.size_class.size
  3028     Numeral.number_of ~> Numeral.number_class.number_of
  3029     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3030     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3031     Orderings.min ~> Orderings.ord_class.min
  3032     Orderings.max ~> Orderings.ord_class.max
  3033     Divides.op div ~> Divides.div_class.div
  3034     Divides.op mod ~> Divides.div_class.mod
  3035     Divides.op dvd ~> Divides.div_class.dvd
  3036 
  3037 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3038 
  3039 a) User-defined constants using any of the names "plus", "minus",
  3040 "times", "less" or "less_eq". The standard syntax translations for
  3041 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3042 names.
  3043 
  3044 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3045 INCOMPATIBILITY: use more specific names.
  3046 
  3047 c) Permutative equations (e.g. "a + b = b + a")
  3048 Since the change of names also changes the order of terms, permutative
  3049 rewrite rules may get applied in a different order. Experience shows
  3050 that this is rarely the case (only two adaptions in the whole Isabelle
  3051 distribution).  INCOMPATIBILITY: rewrite proofs
  3052 
  3053 d) ML code directly refering to constant names
  3054 This in general only affects hand-written proof tactics, simprocs and
  3055 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3056 Consider using @{const_name} antiquotation.
  3057 
  3058 * New class "default" with associated constant "default".
  3059 
  3060 * Function "sgn" is now overloaded and available on int, real, complex
  3061 (and other numeric types), using class "sgn".  Two possible defs of
  3062 sgn are given as equational assumptions in the classes sgn_if and
  3063 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3064 INCOMPATIBILITY.
  3065 
  3066 * Locale "partial_order" now unified with class "order" (cf. theory
  3067 Orderings), added parameter "less".  INCOMPATIBILITY.
  3068 
  3069 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3070 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3071 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3072 
  3073 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3074 changed order of proof goals in instance proofs.
  3075 
  3076 * The transitivity reasoner for partial and linear orders is set up
  3077 for classes "order" and "linorder".  Instances of the reasoner are available
  3078 in all contexts importing or interpreting the corresponding locales.
  3079 Method "order" invokes the reasoner separately; the reasoner
  3080 is also integrated with the Simplifier as a solver.  Diagnostic
  3081 command 'print_orders' shows the available instances of the reasoner
  3082 in the current context.
  3083 
  3084 * Localized monotonicity predicate in theory "Orderings"; integrated
  3085 lemmas max_of_mono and min_of_mono with this predicate.
  3086 INCOMPATIBILITY.
  3087 
  3088 * Formulation of theorem "dense" changed slightly due to integration
  3089 with new class dense_linear_order.
  3090 
  3091 * Uniform lattice theory development in HOL.
  3092 
  3093     constants "meet" and "join" now named "inf" and "sup"
  3094     constant "Meet" now named "Inf"
  3095 
  3096     classes "meet_semilorder" and "join_semilorder" now named
  3097       "lower_semilattice" and "upper_semilattice"
  3098     class "lorder" now named "lattice"
  3099     class "comp_lat" now named "complete_lattice"
  3100 
  3101     Instantiation of lattice classes allows explicit definitions
  3102     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3103 
  3104   INCOMPATIBILITY.  Theorem renames:
  3105 
  3106     meet_left_le            ~> inf_le1
  3107     meet_right_le           ~> inf_le2
  3108     join_left_le            ~> sup_ge1
  3109     join_right_le           ~> sup_ge2
  3110     meet_join_le            ~> inf_sup_ord
  3111     le_meetI                ~> le_infI
  3112     join_leI                ~> le_supI
  3113     le_meet                 ~> le_inf_iff
  3114     le_join                 ~> ge_sup_conv
  3115     meet_idempotent         ~> inf_idem
  3116     join_idempotent         ~> sup_idem
  3117     meet_comm               ~> inf_commute
  3118     join_comm               ~> sup_commute
  3119     meet_leI1               ~> le_infI1
  3120     meet_leI2               ~> le_infI2
  3121     le_joinI1               ~> le_supI1
  3122     le_joinI2               ~> le_supI2
  3123     meet_assoc              ~> inf_assoc
  3124     join_assoc              ~> sup_assoc
  3125     meet_left_comm          ~> inf_left_commute
  3126     meet_left_idempotent    ~> inf_left_idem
  3127     join_left_comm          ~> sup_left_commute
  3128     join_left_idempotent    ~> sup_left_idem
  3129     meet_aci                ~> inf_aci
  3130     join_aci                ~> sup_aci
  3131     le_def_meet             ~> le_iff_inf
  3132     le_def_join             ~> le_iff_sup
  3133     join_absorp2            ~> sup_absorb2
  3134     join_absorp1            ~> sup_absorb1
  3135     meet_absorp1            ~> inf_absorb1
  3136     meet_absorp2            ~> inf_absorb2
  3137     meet_join_absorp        ~> inf_sup_absorb
  3138     join_meet_absorp        ~> sup_inf_absorb
  3139     distrib_join_le         ~> distrib_sup_le
  3140     distrib_meet_le         ~> distrib_inf_le
  3141 
  3142     add_meet_distrib_left   ~> add_inf_distrib_left
  3143     add_join_distrib_left   ~> add_sup_distrib_left
  3144     is_join_neg_meet        ~> is_join_neg_inf
  3145     is_meet_neg_join        ~> is_meet_neg_sup
  3146     add_meet_distrib_right  ~> add_inf_distrib_right
  3147     add_join_distrib_right  ~> add_sup_distrib_right
  3148     add_meet_join_distribs  ~> add_sup_inf_distribs
  3149     join_eq_neg_meet        ~> sup_eq_neg_inf
  3150     meet_eq_neg_join        ~> inf_eq_neg_sup
  3151     add_eq_meet_join        ~> add_eq_inf_sup
  3152     meet_0_imp_0            ~> inf_0_imp_0
  3153     join_0_imp_0            ~> sup_0_imp_0
  3154     meet_0_eq_0             ~> inf_0_eq_0
  3155     join_0_eq_0             ~> sup_0_eq_0
  3156     neg_meet_eq_join        ~> neg_inf_eq_sup
  3157     neg_join_eq_meet        ~> neg_sup_eq_inf
  3158     join_eq_if              ~> sup_eq_if
  3159 
  3160     mono_meet               ~> mono_inf
  3161     mono_join               ~> mono_sup
  3162     meet_bool_eq            ~> inf_bool_eq
  3163     join_bool_eq            ~> sup_bool_eq
  3164     meet_fun_eq             ~> inf_fun_eq
  3165     join_fun_eq             ~> sup_fun_eq
  3166     meet_set_eq             ~> inf_set_eq
  3167     join_set_eq             ~> sup_set_eq
  3168     meet1_iff               ~> inf1_iff
  3169     meet2_iff               ~> inf2_iff
  3170     meet1I                  ~> inf1I
  3171     meet2I                  ~> inf2I
  3172     meet1D1                 ~> inf1D1
  3173     meet2D1                 ~> inf2D1
  3174     meet1D2                 ~> inf1D2
  3175     meet2D2                 ~> inf2D2
  3176     meet1E                  ~> inf1E
  3177     meet2E                  ~> inf2E
  3178     join1_iff               ~> sup1_iff
  3179     join2_iff               ~> sup2_iff
  3180     join1I1                 ~> sup1I1
  3181     join2I1                 ~> sup2I1
  3182     join1I1                 ~> sup1I1
  3183     join2I2                 ~> sup1I2
  3184     join1CI                 ~> sup1CI
  3185     join2CI                 ~> sup2CI
  3186     join1E                  ~> sup1E
  3187     join2E                  ~> sup2E
  3188 
  3189     is_meet_Meet            ~> is_meet_Inf
  3190     Meet_bool_def           ~> Inf_bool_def
  3191     Meet_fun_def            ~> Inf_fun_def
  3192     Meet_greatest           ~> Inf_greatest
  3193     Meet_lower              ~> Inf_lower
  3194     Meet_set_def            ~> Inf_set_def
  3195 
  3196     Sup_def                 ~> Sup_Inf
  3197     Sup_bool_eq             ~> Sup_bool_def
  3198     Sup_fun_eq              ~> Sup_fun_def
  3199     Sup_set_eq              ~> Sup_set_def
  3200 
  3201     listsp_meetI            ~> listsp_infI
  3202     listsp_meet_eq          ~> listsp_inf_eq
  3203 
  3204     meet_min                ~> inf_min
  3205     join_max                ~> sup_max
  3206 
  3207 * Added syntactic class "size"; overloaded constant "size" now has
  3208 type "'a::size ==> bool"
  3209 
  3210 * Internal reorganisation of `size' of datatypes: size theorems
  3211 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3212 simplification rules by default!); theorems "prod.size" now named
  3213 "*.size".
  3214 
  3215 * Class "div" now inherits from class "times" rather than "type".
  3216 INCOMPATIBILITY.
  3217 
  3218 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3219 Linorder etc.  have disappeared; operations defined in terms of
  3220 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3221 
  3222 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3223 
  3224 * HOL-Word: New extensive library and type for generic, fixed size
  3225 machine words, with arithemtic, bit-wise, shifting and rotating
  3226 operations, reflection into int, nat, and bool lists, automation for
  3227 linear arithmetic (by automatic reflection into nat or int), including
  3228 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3229 arithmetic type classes, supporting automatic simplification of
  3230 numerals on all operations.
  3231 
  3232 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3233 
  3234 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3235 
  3236 * Code generator library theories:
  3237   - Code_Integer represents HOL integers by big integer literals in target
  3238     languages.
  3239   - Code_Char represents HOL characters by character literals in target
  3240     languages.
  3241   - Code_Char_chr like Code_Char, but also offers treatment of character
  3242     codes; includes Code_Integer.
  3243   - Executable_Set allows to generate code for finite sets using lists.
  3244   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3245     denominator).
  3246   - Executable_Real implements a subset of real numbers, namly those
  3247     representable by rational numbers.
  3248   - Efficient_Nat implements natural numbers by integers, which in general will
  3249     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3250     includes Code_Integer.
  3251   - Code_Index provides an additional datatype index which is mapped to
  3252     target-language built-in integers.
  3253   - Code_Message provides an additional datatype message_string which is isomorphic to
  3254     strings; messages are mapped to target-language strings.
  3255 
  3256 * New package for inductive predicates
  3257 
  3258   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3259 
  3260     inductive
  3261       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3262       for z_1 :: U_1 and ... and z_n :: U_m
  3263     where
  3264       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3265     | ...
  3266 
  3267   with full support for type-inference, rather than
  3268 
  3269     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3270 
  3271     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3272     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3273 
  3274     inductive "s z_1 ... z_m"
  3275     intros
  3276       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3277       ...
  3278 
  3279   For backward compatibility, there is a wrapper allowing inductive
  3280   sets to be defined with the new package via
  3281 
  3282     inductive_set
  3283       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3284       for z_1 :: U_1 and ... and z_n :: U_m
  3285     where
  3286       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3287     | ...
  3288 
  3289   or
  3290 
  3291     inductive_set
  3292       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3293       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3294       for z_1 :: U_1 and ... and z_n :: U_m
  3295     where
  3296       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3297     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3298     | ...
  3299 
  3300   if the additional syntax "p ..." is required.
  3301 
  3302   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3303   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3304 
  3305   INCOMPATIBILITIES:
  3306 
  3307   - Since declaration and definition of inductive sets or predicates
  3308     is no longer separated, abbreviations involving the newly
  3309     introduced sets or predicates must be specified together with the
  3310     introduction rules after the 'where' keyword (see above), rather
  3311     than before the actual inductive definition.
  3312 
  3313   - The variables in induction and elimination rules are now
  3314     quantified in the order of their occurrence in the introduction
  3315     rules, rather than in alphabetical order. Since this may break
  3316     some proofs, these proofs either have to be repaired, e.g. by
  3317     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3318     statements of the form
  3319 
  3320       case (rule_i a_i_1 ... a_i_{k_i})
  3321 
  3322     or the old order of quantification has to be restored by explicitly adding
  3323     meta-level quantifiers in the introduction rules, i.e.
  3324 
  3325       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3326 
  3327   - The format of the elimination rules is now
  3328 
  3329       p z_1 ... z_m x_1 ... x_n ==>
  3330         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3331         ==> ... ==> P
  3332 
  3333     for predicates and
  3334 
  3335       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3336         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3337         ==> ... ==> P
  3338 
  3339     for sets rather than
  3340 
  3341       x : s z_1 ... z_m ==>
  3342         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3343         ==> ... ==> P
  3344 
  3345     This may require terms in goals to be expanded to n-tuples
  3346     (e.g. using case_tac or simplification with the split_paired_all
  3347     rule) before the above elimination rule is applicable.
  3348 
  3349   - The elimination or case analysis rules for (mutually) inductive
  3350     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3351     list of rules "p_1_..._p_k.elims" is no longer available.
  3352 
  3353 * New package "function"/"fun" for general recursive functions,
  3354 supporting mutual and nested recursion, definitions in local contexts,
  3355 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3356 for small examples, and the separate tutorial on the function
  3357 package. The old recdef "package" is still available as before, but
  3358 users are encouraged to use the new package.
  3359 
  3360 * Method "lexicographic_order" automatically synthesizes termination
  3361 relations as lexicographic combinations of size measures. 
  3362 
  3363 * Case-expressions allow arbitrary constructor-patterns (including
  3364 "_") and take their order into account, like in functional
  3365 programming.  Internally, this is translated into nested
  3366 case-expressions; missing cases are added and mapped to the predefined
  3367 constant "undefined". In complicated cases printing may no longer show
  3368 the original input but the internal form. Lambda-abstractions allow
  3369 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3370 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3371 variable.
  3372 
  3373 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3374 is an abbreviation for "of_nat :: nat => int". The simplification
  3375 rules for "of_nat" have been changed to work like "int" did
  3376 previously.  Potential INCOMPATIBILITY:
  3377   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3378   - of_nat_diff and of_nat_mult are no longer default simp rules
  3379 
  3380 * Method "algebra" solves polynomial equations over (semi)rings using
  3381 Groebner bases. The (semi)ring structure is defined by locales and the
  3382 tool setup depends on that generic context. Installing the method for
  3383 a specific type involves instantiating the locale and possibly adding
  3384 declarations for computation on the coefficients.  The method is
  3385 already instantiated for natural numbers and for the axiomatic class
  3386 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3387 CALCULEMUS 2007 for the general principles underlying this
  3388 architecture of context-aware proof-tools.
  3389 
  3390 * Method "ferrack" implements quantifier elimination over
  3391 special-purpose dense linear orders using locales (analogous to
  3392 "algebra"). The method is already installed for class
  3393 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3394 rat, etc.
  3395 
  3396 * Former constant "List.op @" now named "List.append".  Use ML
  3397 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3398 circumvent possible incompatibilities when working on ML level.
  3399 
  3400 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3401 
  3402 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3403 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3404 
  3405 * New syntax for Haskell-like list comprehension (input only), eg.
  3406 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3407 
  3408 * The special syntax for function "filter" has changed from [x :
  3409 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3410 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3411 
  3412 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3413 defined on nat only, as an abbreviation for [a..<Suc b]
  3414 INCOMPATIBILITY.
  3415 
  3416 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3417 
  3418 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3419 
  3420 * New lemma collection field_simps (an extension of ring_simps) for
  3421 manipulating (in)equations involving division. Multiplies with all
  3422 denominators that can be proved to be non-zero (in equations) or
  3423 positive/negative (in inequations).
  3424 
  3425 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3426 have been improved and renamed to ring_simps, group_simps and
  3427 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3428 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3429 
  3430 * Theory Library/Commutative_Ring: switched from recdef to function
  3431 package; constants add, mul, pow now curried.  Infix syntax for
  3432 algebraic operations.
  3433 
  3434 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3435 INCOMPATIBILITY.
  3436 
  3437 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3438 INCOMPATIBILITY.
  3439 
  3440 * HOL/records: generalised field-update to take a function on the
  3441 field rather than the new value: r(|A := x|) is translated to A_update
  3442 (K x) r The K-combinator that is internally used is called K_record.
  3443 INCOMPATIBILITY: Usage of the plain update functions has to be
  3444 adapted.
  3445  
  3446 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3447 * x = 0, which are required for a semiring.  Richer structures do not
  3448 inherit from semiring_0 anymore, because this property is a theorem
  3449 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3450 there is more to prove, but this is mostly trivial.
  3451 
  3452 * Class "recpower" is generalized to arbitrary monoids, not just
  3453 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3454 commutativity or semiring properties additionally.
  3455 
  3456 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3457 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3458 better use 'abbreviation'.
  3459 
  3460 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3461 
  3462 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3463 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3464 significant changes for setting up numeral syntax for types:
  3465   - New constants Numeral.pred and Numeral.succ instead
  3466       of former Numeral.bin_pred and Numeral.bin_succ.
  3467   - Use integer operations instead of bin_add, bin_mult and so on.
  3468   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3469   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3470 
  3471 See src/HOL/Integ/IntArith.thy for an example setup.
  3472 
  3473 * Command 'normal_form' computes the normal form of a term that may
  3474 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3475 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3476 heavy-duty computations because the functions are compiled to ML
  3477 first.  Correspondingly, a method "normalization" is provided.  See
  3478 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3479 
  3480 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3481 25 like -->); output depends on the "iff" print_mode, the default is
  3482 "A = B" (with priority 50).
  3483 
  3484 * Relations less (<) and less_eq (<=) are also available on type bool.
  3485 Modified syntax to disallow nesting without explicit parentheses,
  3486 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3487 INCOMPATIBILITY.
  3488 
  3489 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3490 
  3491 * Relation composition operator "op O" now has precedence 75 and binds
  3492 stronger than union and intersection. INCOMPATIBILITY.
  3493 
  3494 * The old set interval syntax "{m..n(}" (and relatives) has been
  3495 removed.  Use "{m..<n}" (and relatives) instead.
  3496 
  3497 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3498 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3499 ``declare [[simproc del: neq]]''.
  3500 
  3501 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3502 True/False.
  3503 
  3504 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3505 
  3506 * Theorem setsum_mult renamed to setsum_right_distrib.
  3507 
  3508 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3509 ``rule'' method.
  3510 
  3511 * Reimplemented methods "sat" and "satx", with several improvements:
  3512 goals no longer need to be stated as "<prems> ==> False", equivalences
  3513 (i.e. "=" on type bool) are handled, variable names of the form
  3514 "lit_<n>" are no longer reserved, significant speedup.
  3515 
  3516 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3517 zChaff is still supported as well.
  3518 
  3519 * 'inductive' and 'datatype': provide projections of mutual rules,
  3520 bundled as foo_bar.inducts;
  3521 
  3522 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3523 Library.
  3524 
  3525 * Library: moved theory Accessible_Part to main HOL.
  3526 
  3527 * Library: added theory Coinductive_List of potentially infinite lists
  3528 as greatest fixed-point.
  3529 
  3530 * Library: added theory AssocList which implements (finite) maps as
  3531 association lists.
  3532 
  3533 * Method "evaluation" solves goals (i.e. a boolean expression)
  3534 efficiently by compiling it to ML.  The goal is "proved" (via an
  3535 oracle) if it evaluates to True.
  3536 
  3537 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3538 also when invoked by the simplifier.  This results in the Simplifier
  3539 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3540 Configuration option fast_arith_split_limit=0 recovers the old
  3541 behavior.
  3542 
  3543 * Support for hex (0x20) and binary (0b1001) numerals.
  3544 
  3545 * New method: reify eqs (t), where eqs are equations for an
  3546 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3547 parameter, computes a term s::'b and a list xs::'a list and proves the
  3548 theorem I xs s = t. This is also known as reification or quoting. The
  3549 resulting theorem is applied to the subgoal to substitute t with I xs
  3550 s.  If t is omitted, the subgoal itself is reified.
  3551 
  3552 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3553 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3554 where f is supposed to be a computable function (in the sense of code
  3555 generattion). The method uses reify to compute s and xs as above then
  3556 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3557 r and finally gets the theorem t = r, which is again applied to the
  3558 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3559 
  3560 * Reflection: Automatic reification now handels binding, an example is
  3561 available in src/HOL/ex/ReflectionEx.thy
  3562 
  3563 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3564 command 'statespace' that is similar to 'record', but introduces an
  3565 abstract specification based on the locale infrastructure instead of
  3566 HOL types.  This leads to extra flexibility in composing state spaces,
  3567 in particular multiple inheritance and renaming of components.
  3568 
  3569 
  3570 *** HOL-Complex ***
  3571 
  3572 * Hyperreal: Functions root and sqrt are now defined on negative real
  3573 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3574 Nonnegativity side conditions have been removed from many lemmas, so
  3575 that more subgoals may now be solved by simplification; potential
  3576 INCOMPATIBILITY.
  3577 
  3578 * Real: new type classes formalize real normed vector spaces and
  3579 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3580 and norm :: 'a => real.
  3581 
  3582 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3583 reals into other types. The overloaded constant Reals :: 'a set is now
  3584 defined as range of_real; potential INCOMPATIBILITY.
  3585 
  3586 * Real: proper support for ML code generation, including 'quickcheck'.
  3587 Reals are implemented as arbitrary precision rationals.
  3588 
  3589 * Hyperreal: Several constants that previously worked only for the
  3590 reals have been generalized, so they now work over arbitrary vector
  3591 spaces. Type annotations may need to be added in some cases; potential
  3592 INCOMPATIBILITY.
  3593 
  3594   Infinitesimal  :: ('a::real_normed_vector) star set
  3595   HFinite        :: ('a::real_normed_vector) star set
  3596   HInfinite      :: ('a::real_normed_vector) star set
  3597   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3598   monad          :: ('a::real_normed_vector) star => 'a star set
  3599   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3600   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3601   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3602   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3603   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3604   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3605   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3606   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3607   sgn            :: 'a::real_normed_vector => 'a
  3608   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3609 
  3610 * Complex: Some complex-specific constants are now abbreviations for
  3611 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3612 hnorm.  Other constants have been entirely removed in favor of the
  3613 polymorphic versions (INCOMPATIBILITY):
  3614 
  3615   approx        <-- capprox
  3616   HFinite       <-- CFinite
  3617   HInfinite     <-- CInfinite
  3618   Infinitesimal <-- CInfinitesimal
  3619   monad         <-- cmonad
  3620   galaxy        <-- cgalaxy
  3621   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3622   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3623   (ns)deriv     <-- (ns)cderiv
  3624 
  3625 
  3626 *** HOL-Algebra ***
  3627 
  3628 * Formalisation of ideals and the quotient construction over rings.
  3629 
  3630 * Order and lattice theory no longer based on records.
  3631 INCOMPATIBILITY.
  3632 
  3633 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3634 greatest_closed.  INCOMPATIBILITY.
  3635 
  3636 * Method algebra is now set up via an attribute.  For examples see
  3637 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3638 of algebraic structures.
  3639 
  3640 * Renamed theory CRing to Ring.
  3641 
  3642 
  3643 *** HOL-Nominal ***
  3644 
  3645 * Substantial, yet incomplete support for nominal datatypes (binding
  3646 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3647 src/HOL/Nominal/Examples.  Prospective users should consult
  3648 http://isabelle.in.tum.de/nominal/
  3649 
  3650 
  3651 *** ML ***
  3652 
  3653 * ML basics: just one true type int, which coincides with IntInf.int
  3654 (even on SML/NJ).
  3655 
  3656 * ML within Isar: antiquotations allow to embed statically-checked
  3657 formal entities in the source, referring to the context available at
  3658 compile-time.  For example:
  3659 
  3660 ML {* @{sort "{zero,one}"} *}
  3661 ML {* @{typ "'a => 'b"} *}
  3662 ML {* @{term "%x. x"} *}
  3663 ML {* @{prop "x == y"} *}
  3664 ML {* @{ctyp "'a => 'b"} *}
  3665 ML {* @{cterm "%x. x"} *}
  3666 ML {* @{cprop "x == y"} *}
  3667 ML {* @{thm asm_rl} *}
  3668 ML {* @{thms asm_rl} *}
  3669 ML {* @{type_name c} *}
  3670 ML {* @{type_syntax c} *}
  3671 ML {* @{const_name c} *}
  3672 ML {* @{const_syntax c} *}
  3673 ML {* @{context} *}
  3674 ML {* @{theory} *}
  3675 ML {* @{theory Pure} *}
  3676 ML {* @{theory_ref} *}
  3677 ML {* @{theory_ref Pure} *}
  3678 ML {* @{simpset} *}
  3679 ML {* @{claset} *}
  3680 ML {* @{clasimpset} *}
  3681 
  3682 The same works for sources being ``used'' within an Isar context.
  3683 
  3684 * ML in Isar: improved error reporting; extra verbosity with
  3685 ML_Context.trace enabled.
  3686 
  3687 * Pure/General/table.ML: the join operations now works via exceptions
  3688 DUP/SAME instead of type option. This is simpler in simple cases, and
  3689 admits slightly more efficient complex applications.
  3690 
  3691 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3692 use Context.generic instead of just theory.
  3693 
  3694 * Pure: datatype Context.generic joins theory/Proof.context and
  3695 provides some facilities for code that works in either kind of
  3696 context, notably GenericDataFun for uniform theory and proof data.
  3697 
  3698 * Pure: simplified internal attribute type, which is now always
  3699 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3700 local (Proof.context) attributes have been discontinued, while
  3701 minimizing code duplication. Thm.rule_attribute and
  3702 Thm.declaration_attribute build canonical attributes; see also structure
  3703 Context for further operations on Context.generic, notably
  3704 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3705 declarations and definitions.
  3706 
  3707 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3708 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3709 init only required for impure data. INCOMPATIBILITY: empty really need
  3710 to be empty (no dependencies on theory content!)
  3711 
  3712 * Pure/kernel: consts certification ignores sort constraints given in
  3713 signature declarations. (This information is not relevant to the
  3714 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3715 potential INCOMPATIBILITY.
  3716 
  3717 * Pure: axiomatic type classes are now purely definitional, with
  3718 explicit proofs of class axioms and super class relations performed
  3719 internally. See Pure/axclass.ML for the main internal interfaces --
  3720 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3721 AxClass.axiomatize_class/classrel/arity supersede
  3722 Sign.add_classes/classrel/arities.
  3723 
  3724 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3725 global/local versions on theory vs. Proof.context have been
  3726 discontinued; Attrib.syntax and Method.syntax have been adapted
  3727 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3728 attributes, methods, etc.
  3729 
  3730 * Pure: several functions of signature "... -> theory -> theory * ..."
  3731 have been reoriented to "... -> theory -> ... * theory" in order to
  3732 allow natural usage in combination with the ||>, ||>>, |-> and
  3733 fold_map combinators.
  3734 
  3735 * Pure: official theorem names (closed derivations) and additional
  3736 comments (tags) are now strictly separate.  Name hints -- which are
  3737 maintained as tags -- may be attached any time without affecting the
  3738 derivation.
  3739 
  3740 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3741 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3742 achieve the old behaviour.
  3743 
  3744 * Pure: the "Goal" constant is now called "prop", supporting a
  3745 slightly more general idea of ``protecting'' meta-level rule
  3746 statements.
  3747 
  3748 * Pure: Logic.(un)varify only works in a global context, which is now
  3749 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3750 Logic.legacy_(un)varify as temporary workaround.
  3751 
  3752 * Pure: structure Name provides scalable operations for generating
  3753 internal variable names, notably Name.variants etc.  This replaces
  3754 some popular functions from term.ML:
  3755 
  3756   Term.variant		->  Name.variant
  3757   Term.variantlist	->  Name.variant_list
  3758   Term.invent_names	->  Name.invent_list
  3759 
  3760 Note that low-level renaming rarely occurs in new code -- operations
  3761 from structure Variable are used instead (see below).
  3762 
  3763 * Pure: structure Variable provides fundamental operations for proper
  3764 treatment of fixed/schematic variables in a context.  For example,
  3765 Variable.import introduces fixes for schematics of given facts and
  3766 Variable.export reverses the effect (up to renaming) -- this replaces
  3767 various freeze_thaw operations.
  3768 
  3769 * Pure: structure Goal provides simple interfaces for
  3770 init/conclude/finish and tactical prove operations (replacing former
  3771 Tactic.prove).  Goal.prove is the canonical way to prove results
  3772 within a given context; Goal.prove_global is a degraded version for
  3773 theory level goals, including a global Drule.standard.  Note that
  3774 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3775 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3776 in a locale context).
  3777 
  3778 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3779 and type checking (Syntax.check_term etc.), with common combinations
  3780 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3781 which are considered legacy and await removal.
  3782 
  3783 * Pure/Syntax: generic interfaces for type unchecking
  3784 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3785 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3786 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3787 available for convenience, but refer to the very same operations using
  3788 a mere theory instead of a full context.
  3789 
  3790 * Isar: simplified treatment of user-level errors, using exception
  3791 ERROR of string uniformly.  Function error now merely raises ERROR,
  3792 without any side effect on output channels.  The Isar toplevel takes
  3793 care of proper display of ERROR exceptions.  ML code may use plain
  3794 handle/can/try; cat_error may be used to concatenate errors like this:
  3795 
  3796   ... handle ERROR msg => cat_error msg "..."
  3797 
  3798 Toplevel ML code (run directly or through the Isar toplevel) may be
  3799 embedded into the Isar toplevel with exception display/debug like
  3800 this:
  3801 
  3802   Isar.toplevel (fn () => ...)
  3803 
  3804 INCOMPATIBILITY, removed special transform_error facilities, removed
  3805 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3806 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3807 -- use plain ERROR instead.
  3808 
  3809 * Isar: theory setup now has type (theory -> theory), instead of a
  3810 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3811 
  3812 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3813 ProofContext.debug/verbose flags.
  3814 
  3815 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3816 theory before entering a proof state.  Transactions now always see a
  3817 quasi-functional intermediate checkpoint, both in interactive and
  3818 batch mode.
  3819 
  3820 * Isar: simplified interfaces for outer syntax.  Renamed
  3821 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3822 OuterSyntax.add_parsers -- this functionality is now included in
  3823 OuterSyntax.command etc.  INCOMPATIBILITY.
  3824 
  3825 * Simplifier: the simpset of a running simplification process now
  3826 contains a proof context (cf. Simplifier.the_context), which is the
  3827 very context that the initial simpset has been retrieved from (by
  3828 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3829 (solver, looper etc.) may depend on arbitrary proof data.
  3830 
  3831 * Simplifier.inherit_context inherits the proof context (plus the
  3832 local bounds) of the current simplification process; any simproc
  3833 etc. that calls the Simplifier recursively should do this!  Removed
  3834 former Simplifier.inherit_bounds, which is already included here --
  3835 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3836 specify an explicit context using Simplifier.context/theory_context.
  3837 
  3838 * Simplifier/Classical Reasoner: more abstract interfaces
  3839 change_simpset/claset for modifying the simpset/claset reference of a
  3840 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3841 INCOMPATIBILITY.
  3842 
  3843 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3844 "Trueprop" etc.
  3845 
  3846 
  3847 *** System ***
  3848 
  3849 * settings: the default heap location within ISABELLE_HOME_USER now
  3850 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3851 Isabelle installations.
  3852 
  3853 * isabelle-process: option -S (secure mode) disables some critical
  3854 operations, notably runtime compilation and evaluation of ML source
  3855 code.
  3856 
  3857 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3858 
  3859 * Support for parallel execution, using native multicore support of
  3860 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3861 independent theories, according to the given theory header
  3862 specifications. The maximum number of worker threads is specified via
  3863 usedir option -M or the "max-threads" setting in Proof General. A
  3864 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3865 to 6 on a 8-core machine.  User-code needs to observe certain
  3866 guidelines for thread-safe programming, see appendix A in the Isar
  3867 Implementation manual.
  3868 
  3869 
  3870 
  3871 New in Isabelle2005 (October 2005)
  3872 ----------------------------------
  3873 
  3874 *** General ***
  3875 
  3876 * Theory headers: the new header syntax for Isar theories is
  3877 
  3878   theory <name>
  3879   imports <theory1> ... <theoryN>
  3880   uses <file1> ... <fileM>
  3881   begin
  3882 
  3883 where the 'uses' part is optional.  The previous syntax
  3884 
  3885   theory <name> = <theory1> + ... + <theoryN>:
  3886 
  3887 will disappear in the next release.  Use isatool fixheaders to convert
  3888 existing theory files.  Note that there is no change in ancient
  3889 non-Isar theories now, but these will disappear soon.
  3890 
  3891 * Theory loader: parent theories can now also be referred to via
  3892 relative and absolute paths.
  3893 
  3894 * Command 'find_theorems' searches for a list of criteria instead of a
  3895 list of constants. Known criteria are: intro, elim, dest, name:string,
  3896 simp:term, and any term. Criteria can be preceded by '-' to select
  3897 theorems that do not match. Intro, elim, dest select theorems that
  3898 match the current goal, name:s selects theorems whose fully qualified
  3899 name contain s, and simp:term selects all simplification rules whose
  3900 lhs match term.  Any other term is interpreted as pattern and selects
  3901 all theorems matching the pattern. Available in ProofGeneral under
  3902 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3903 
  3904   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3905 
  3906 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3907 matching the current goal as introduction rule and not having "HOL."
  3908 in their name (i.e. not being defined in theory HOL).
  3909 
  3910 * Command 'thms_containing' has been discontinued in favour of
  3911 'find_theorems'; INCOMPATIBILITY.
  3912 
  3913 * Communication with Proof General is now 8bit clean, which means that
  3914 Unicode text in UTF-8 encoding may be used within theory texts (both
  3915 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3916 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3917 
  3918   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3919   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3920 
  3921 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3922 Classical Reasoner.  Typical big applications run around 2 times
  3923 faster.
  3924 
  3925 
  3926 *** Document preparation ***
  3927 
  3928 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3929 of raw sources.  Only those symbols that do not require additional
  3930 LaTeX packages (depending on comments in isabellesym.sty) are
  3931 displayed properly, everything else is left verbatim.  isatool display
  3932 and isatool print are used as front ends (these are subject to the
  3933 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3934 
  3935 * Command tags control specific markup of certain regions of text,
  3936 notably folding and hiding.  Predefined tags include "theory" (for
  3937 theory begin and end), "proof" for proof commands, and "ML" for
  3938 commands involving ML code; the additional tags "visible" and
  3939 "invisible" are unused by default.  Users may give explicit tag
  3940 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3941 interpretation of tags is determined by the LaTeX job during document
  3942 preparation: see option -V of isatool usedir, or options -n and -t of
  3943 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3944 \isadroptag.
  3945 
  3946 Several document versions may be produced at the same time via isatool
  3947 usedir (the generated index.html will link all of them).  Typical
  3948 specifications include ''-V document=theory,proof,ML'' to present
  3949 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3950 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3951 these parts without any formal replacement text.  The Isabelle site
  3952 default settings produce ''document'' and ''outline'' versions as
  3953 specified above.
  3954 
  3955 * Several new antiquotations:
  3956 
  3957   @{term_type term} prints a term with its type annotated;
  3958 
  3959   @{typeof term} prints the type of a term;
  3960 
  3961   @{const const} is the same as @{term const}, but checks that the
  3962   argument is a known logical constant;
  3963 
  3964   @{term_style style term} and @{thm_style style thm} print a term or
  3965   theorem applying a "style" to it
  3966 
  3967   @{ML text}
  3968 
  3969 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3970 definitions, equations, inequations etc., 'concl' printing only the
  3971 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3972 to print the specified premise.  TermStyle.add_style provides an ML
  3973 interface for introducing further styles.  See also the "LaTeX Sugar"
  3974 document practical applications.  The ML antiquotation prints
  3975 type-checked ML expressions verbatim.
  3976 
  3977 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3978 and 'text' support optional locale specification '(in loc)', which
  3979 specifies the default context for interpreting antiquotations.  For
  3980 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3981 
  3982 * Option 'locale=NAME' of antiquotations specifies an alternative
  3983 context interpreting the subsequent argument.  For example: @{thm
  3984 [locale=lattice] inf_assoc}.
  3985 
  3986 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3987 a proof context.
  3988 
  3989 * Proper output of antiquotations for theory commands involving a
  3990 proof context (such as 'locale' or 'theorem (in loc) ...').
  3991 
  3992 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3993 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3994 
  3995 * isatool usedir: new option -C (default true) controls whether option
  3996 -D should include a copy of the original document directory; -C false
  3997 prevents unwanted effects such as copying of administrative CVS data.
  3998 
  3999 
  4000 *** Pure ***
  4001 
  4002 * Considerably improved version of 'constdefs' command.  Now performs
  4003 automatic type-inference of declared constants; additional support for
  4004 local structure declarations (cf. locales and HOL records), see also
  4005 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4006 sequential dependencies of definitions within a single 'constdefs'
  4007 section; moreover, the declared name needs to be an identifier.  If
  4008 all fails, consider to fall back on 'consts' and 'defs' separately.
  4009 
  4010 * Improved indexed syntax and implicit structures.  First of all,
  4011 indexed syntax provides a notational device for subscripted
  4012 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4013 expressions.  Secondly, in a local context with structure
  4014 declarations, number indexes \<^sub>n or the empty index (default
  4015 number 1) refer to a certain fixed variable implicitly; option
  4016 show_structs controls printing of implicit structures.  Typical
  4017 applications of these concepts involve record types and locales.
  4018 
  4019 * New command 'no_syntax' removes grammar declarations (and
  4020 translations) resulting from the given syntax specification, which is
  4021 interpreted in the same manner as for the 'syntax' command.
  4022 
  4023 * 'Advanced' translation functions (parse_translation etc.) may depend
  4024 on the signature of the theory context being presently used for
  4025 parsing/printing, see also isar-ref manual.
  4026 
  4027 * Improved 'oracle' command provides a type-safe interface to turn an
  4028 ML expression of type theory -> T -> term into a primitive rule of
  4029 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4030 is already included here); see also FOL/ex/IffExample.thy;
  4031 INCOMPATIBILITY.
  4032 
  4033 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4034 before); "cI" is no longer bound, use "c.intro" instead.
  4035 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4036 axclasses vs. locales.
  4037 
  4038 * Improved internal renaming of symbolic identifiers -- attach primes
  4039 instead of base 26 numbers.
  4040 
  4041 * New flag show_question_marks controls printing of leading question
  4042 marks in schematic variable names.
  4043 
  4044 * In schematic variable names, *any* symbol following \<^isub> or
  4045 \<^isup> is now treated as part of the base name.  For example, the
  4046 following works without printing of awkward ".0" indexes:
  4047 
  4048   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4049     by simp
  4050 
  4051 * Inner syntax includes (*(*nested*) comments*).
  4052 
  4053 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4054 annotations as "(00...)".
  4055 
  4056 * Clear separation of logical types and nonterminals, where the latter
  4057 may only occur in 'syntax' specifications or type abbreviations.
  4058 Before that distinction was only partially implemented via type class
  4059 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4060 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4061 exotic syntax specifications may require further adaption
  4062 (e.g. Cube/Cube.thy).
  4063 
  4064 * Removed obsolete type class "logic", use the top sort {} instead.
  4065 Note that non-logical types should be declared as 'nonterminals'
  4066 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4067 specifications.
  4068 
  4069 * Attributes 'induct' and 'cases': type or set names may now be
  4070 locally fixed variables as well.
  4071 
  4072 * Simplifier: can now control the depth to which conditional rewriting
  4073 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4074 Limit.
  4075 
  4076 * Simplifier: simplification procedures may now take the current
  4077 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4078 interface), which is very useful for calling the Simplifier
  4079 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4080 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4081 low-level mk_simproc no longer applies Logic.varify internally, to
  4082 allow for use in a context of fixed variables.
  4083 
  4084 * thin_tac now works even if the assumption being deleted contains !!
  4085 or ==>.  More generally, erule now works even if the major premise of
  4086 the elimination rule contains !! or ==>.
  4087 
  4088 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4089 
  4090 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4091 from Pure, which contains all common declarations already.  Both
  4092 theories are defined via plain Isabelle/Isar .thy files.
  4093 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4094 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4095 use isatool fixcpure to adapt your theory and ML sources.
  4096 
  4097 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4098 selections of theorems in named facts via index ranges.
  4099 
  4100 * 'print_theorems': in theory mode, really print the difference
  4101 wrt. the last state (works for interactive theory development only),
  4102 in proof mode print all local facts (cf. 'print_facts');
  4103 
  4104 * 'hide': option '(open)' hides only base names.
  4105 
  4106 * More efficient treatment of intermediate checkpoints in interactive
  4107 theory development.
  4108 
  4109 * Code generator is now invoked via code_module (incremental code
  4110 generation) and code_library (modular code generation, ML structures
  4111 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4112 must be quoted when used as identifiers.
  4113 
  4114 * New 'value' command for reading, evaluating and printing terms using
  4115 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4116 quoted when used as identifier.
  4117 
  4118 
  4119 *** Locales ***
  4120 
  4121 * New commands for the interpretation of locale expressions in
  4122 theories (1), locales (2) and proof contexts (3).  These generate
  4123 proof obligations from the expression specification.  After the
  4124 obligations have been discharged, theorems of the expression are added
  4125 to the theory, target locale or proof context.  The synopsis of the
  4126 commands is a follows:
  4127 
  4128   (1) interpretation expr inst
  4129   (2) interpretation target < expr
  4130   (3) interpret expr inst
  4131 
  4132 Interpretation in theories and proof contexts require a parameter
  4133 instantiation of terms from the current context.  This is applied to
  4134 specifications and theorems of the interpreted expression.
  4135 Interpretation in locales only permits parameter renaming through the
  4136 locale expression.  Interpretation is smart in that interpretations
  4137 that are active already do not occur in proof obligations, neither are
  4138 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4139 inspect active interpretations of a particular locale.  For details,
  4140 see the Isar Reference manual.  Examples can be found in
  4141 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4142 
  4143 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4144 'interpret' instead.
  4145 
  4146 * New context element 'constrains' for adding type constraints to
  4147 parameters.
  4148 
  4149 * Context expressions: renaming of parameters with syntax
  4150 redeclaration.
  4151 
  4152 * Locale declaration: 'includes' disallowed.
  4153 
  4154 * Proper static binding of attribute syntax -- i.e. types / terms /
  4155 facts mentioned as arguments are always those of the locale definition
  4156 context, independently of the context of later invocations.  Moreover,
  4157 locale operations (renaming and type / term instantiation) are applied
  4158 to attribute arguments as expected.
  4159 
  4160 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4161 actual attributes; rare situations may require Attrib.attribute to
  4162 embed those attributes into Attrib.src that lack concrete syntax.
  4163 Attribute implementations need to cooperate properly with the static
  4164 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4165 Attrib.XXX_thm etc. already do the right thing without further
  4166 intervention.  Only unusual applications -- such as "where" or "of"
  4167 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4168 on the context and the facts involved -- may have to assign parsed
  4169 values to argument tokens explicitly.
  4170 
  4171 * Changed parameter management in theorem generation for long goal
  4172 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4173 theorem statement in rare situations.
  4174 
  4175 * Locale inspection command 'print_locale' omits notes elements.  Use
  4176 'print_locale!' to have them included in the output.
  4177 
  4178 
  4179 *** Provers ***
  4180 
  4181 * Provers/hypsubst.ML: improved version of the subst method, for
  4182 single-step rewriting: it now works in bound variable contexts. New is
  4183 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4184 rewrite a different subterm than the original subst method, which is
  4185 still available as 'simplesubst'.
  4186 
  4187 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4188 and quasi orders.
  4189 
  4190 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4191 reflexive-transitive closure of relations.
  4192 
  4193 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4194 limit (previously hard-coded with a value of 20) user-definable.
  4195 
  4196 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4197 is peformed already.  Object-logics merely need to finish their
  4198 initial simpset configuration as before.  INCOMPATIBILITY.
  4199 
  4200 
  4201 *** HOL ***
  4202 
  4203 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4204 
  4205   syntax (epsilon)
  4206     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4207 
  4208 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4209 and x-symbol; use option '-m epsilon' to get it actually printed.
  4210 Moreover, the mathematically important symbolic identifier \<epsilon>
  4211 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4212 
  4213 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4214 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4215 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4216 support corresponding Isar calculations.
  4217 
  4218 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4219 instead of ":".
  4220 
  4221 * theory SetInterval: changed the syntax for open intervals:
  4222 
  4223   Old       New
  4224   {..n(}    {..<n}
  4225   {)n..}    {n<..}
  4226   {m..n(}   {m..<n}
  4227   {)m..n}   {m<..n}
  4228   {)m..n(}  {m<..<n}
  4229 
  4230 The old syntax is still supported but will disappear in the next
  4231 release.  For conversion use the following Emacs search and replace
  4232 patterns (these are not perfect but work quite well):
  4233 
  4234   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4235   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4236 
  4237 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4238 equalities in commutative rings; method 'algebra' provides a generic
  4239 interface.
  4240 
  4241 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4242 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4243 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4244 be a tuple pattern.
  4245 
  4246 Some new syntax forms are available:
  4247 
  4248   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4249   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4250   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4251   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4252 
  4253 The latter form "\<Sum>x < k. e" used to be based on a separate
  4254 function "Summation", which has been discontinued.
  4255 
  4256 * theory Finite_Set: in structured induction proofs, the insert case
  4257 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4258 (insert F x)'.
  4259 
  4260 * The 'refute' command has been extended to support a much larger
  4261 fragment of HOL, including axiomatic type classes, constdefs and
  4262 typedefs, inductive datatypes and recursion.
  4263 
  4264 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4265 Requires zChaff with proof generation to be installed.  See
  4266 HOL/ex/SAT_Examples.thy for examples.
  4267 
  4268 * Datatype induction via method 'induct' now preserves the name of the
  4269 induction variable. For example, when proving P(xs::'a list) by
  4270 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4271 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4272 in unstructured proof scripts.
  4273 
  4274 * Reworked implementation of records.  Improved scalability for
  4275 records with many fields, avoiding performance problems for type
  4276 inference. Records are no longer composed of nested field types, but
  4277 of nested extension types. Therefore the record type only grows linear
  4278 in the number of extensions and not in the number of fields.  The
  4279 top-level (users) view on records is preserved.  Potential
  4280 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4281 old record representation. The type generated for a record is called
  4282 <record_name>_ext_type.
  4283 
  4284 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4285 proofs triggered by a record definition or a simproc (if
  4286 quick_and_dirty is enabled).  Definitions of large records can take
  4287 quite long.
  4288 
  4289 New simproc record_upd_simproc for simplification of multiple record
  4290 updates enabled by default.  Moreover, trivial updates are also
  4291 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4292 occasionally, since simplification is more powerful by default.
  4293 
  4294 * typedef: proper support for polymorphic sets, which contain extra
  4295 type-variables in the term.
  4296 
  4297 * Simplifier: automatically reasons about transitivity chains
  4298 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4299 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4300 old proofs break occasionally as simplification may now solve more
  4301 goals than previously.
  4302 
  4303 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4304 present.  Works for all partial orders (class "order"), in particular
  4305 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4306 just like y <= x.
  4307 
  4308 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4309 bound variable or a constant then the let is unfolded.  Otherwise
  4310 first a is simplified to b, and then f b is simplified to g. If
  4311 possible we abstract b from g arriving at "let x = b in h x",
  4312 otherwise we unfold the let and arrive at g.  The simproc can be
  4313 enabled/disabled by the reference use_let_simproc.  Potential
  4314 INCOMPATIBILITY since simplification is more powerful by default.
  4315 
  4316 * Classical reasoning: the meson method now accepts theorems as arguments.
  4317 
  4318 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4319 jobs to provide advice on the provability of subgoals.
  4320 
  4321 * Theory OrderedGroup and Ring_and_Field: various additions and
  4322 improvements to faciliate calculations involving equalities and
  4323 inequalities.
  4324 
  4325 The following theorems have been eliminated or modified
  4326 (INCOMPATIBILITY):
  4327 
  4328   abs_eq             now named abs_of_nonneg
  4329   abs_of_ge_0        now named abs_of_nonneg
  4330   abs_minus_eq       now named abs_of_nonpos
  4331   imp_abs_id         now named abs_of_nonneg
  4332   imp_abs_neg_id     now named abs_of_nonpos
  4333   mult_pos           now named mult_pos_pos
  4334   mult_pos_le        now named mult_nonneg_nonneg
  4335   mult_pos_neg_le    now named mult_nonneg_nonpos
  4336   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4337   mult_neg           now named mult_neg_neg
  4338   mult_neg_le        now named mult_nonpos_nonpos
  4339 
  4340 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4341      
  4342      zero_le_square
  4343      not_square_less_zero 
  4344 
  4345   The following lemmas have been deleted from Real/RealPow:
  4346   
  4347      realpow_zero_zero
  4348      realpow_two
  4349      realpow_less
  4350      zero_le_power
  4351      realpow_two_le
  4352      abs_realpow_two
  4353      realpow_two_abs     
  4354 
  4355 * Theory Parity: added rules for simplifying exponents.
  4356 
  4357 * Theory List:
  4358 
  4359 The following theorems have been eliminated or modified
  4360 (INCOMPATIBILITY):
  4361 
  4362   list_all_Nil       now named list_all.simps(1)
  4363   list_all_Cons      now named list_all.simps(2)
  4364   list_all_conv      now named list_all_iff
  4365   set_mem_eq         now named mem_iff
  4366 
  4367 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4368 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4369 
  4370 
  4371 *** HOL-Complex ***
  4372 
  4373 * Theory RealDef: better support for embedding natural numbers and
  4374 integers in the reals.
  4375 
  4376 The following theorems have been eliminated or modified
  4377 (INCOMPATIBILITY):
  4378 
  4379   exp_ge_add_one_self  now requires no hypotheses
  4380   real_of_int_add      reversed direction of equality (use [symmetric])
  4381   real_of_int_minus    reversed direction of equality (use [symmetric])
  4382   real_of_int_diff     reversed direction of equality (use [symmetric])
  4383   real_of_int_mult     reversed direction of equality (use [symmetric])
  4384 
  4385 * Theory RComplete: expanded support for floor and ceiling functions.
  4386 
  4387 * Theory Ln is new, with properties of the natural logarithm
  4388 
  4389 * Hyperreal: There is a new type constructor "star" for making
  4390 nonstandard types.  The old type names are now type synonyms:
  4391 
  4392   hypreal = real star
  4393   hypnat = nat star
  4394   hcomplex = complex star
  4395 
  4396 * Hyperreal: Many groups of similarly-defined constants have been
  4397 replaced by polymorphic versions (INCOMPATIBILITY):
  4398 
  4399   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4400 
  4401   starset      <-- starsetNat, starsetC
  4402   *s*          <-- *sNat*, *sc*
  4403   starset_n    <-- starsetNat_n, starsetC_n
  4404   *sn*         <-- *sNatn*, *scn*
  4405   InternalSets <-- InternalNatSets, InternalCSets
  4406 
  4407   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4408   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4409   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4410   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4411   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4412 
  4413 * Hyperreal: Many type-specific theorems have been removed in favor of
  4414 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4415 
  4416   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4417   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4418   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4419   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4420   right_minus <-- hypreal_add_minus
  4421   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4422   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4423   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4424   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4425   mult_1_right <-- hcomplex_mult_one_right
  4426   mult_zero_left <-- hcomplex_mult_zero_left
  4427   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4428   right_distrib <-- hypnat_add_mult_distrib2
  4429   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4430   right_inverse <-- hypreal_mult_inverse
  4431   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4432   order_refl <-- {hypreal,hypnat}_le_refl
  4433   order_trans <-- {hypreal,hypnat}_le_trans
  4434   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4435   order_less_le <-- {hypreal,hypnat}_less_le
  4436   linorder_linear <-- {hypreal,hypnat}_le_linear
  4437   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4438   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4439   add_nonneg_nonneg <-- hypreal_le_add_order
  4440 
  4441 * Hyperreal: Separate theorems having to do with type-specific
  4442 versions of constants have been merged into theorems that apply to the
  4443 new polymorphic constants (INCOMPATIBILITY):
  4444 
  4445   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4446   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4447   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4448   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4449   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4450   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4451   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4452   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4453   STAR_diff <-- {STAR,STARC}_diff
  4454   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4455     STARC_hcomplex_of_complex}_image_subset
  4456   starset_n_Un <-- starset{Nat,C}_n_Un
  4457   starset_n_Int <-- starset{Nat,C}_n_Int
  4458   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4459   starset_n_diff <-- starset{Nat,C}_n_diff
  4460   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4461   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4462   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4463   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4464   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4465   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4466   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4467   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4468   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4469   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4470   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4471   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4472   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4473   starfun_diff <-- starfun{C,RC,CR}_diff
  4474   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4475   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4476   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4477   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4478   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4479   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4480   starfun_Id <-- starfunC_Id
  4481   starfun_approx <-- starfun{Nat,CR}_approx
  4482   starfun_capprox <-- starfun{C,RC}_capprox
  4483   starfun_abs <-- starfunNat_rabs
  4484   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4485   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4486   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4487   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4488   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4489   starfun_add_approx <-- starfunCR_add_approx
  4490   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4491   starfun_divide <-- starfun{C,CR,RC}_divide
  4492   starfun_n <-- starfun{Nat,C}_n
  4493   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4494   starfun_n_add <-- starfun{Nat,C}_n_add
  4495   starfun_n_add_minus <-- starfunNat_n_add_minus
  4496   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4497   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4498   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4499 
  4500   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4501   star_n_minus <-- {hypreal,hcomplex}_minus
  4502   star_n_diff <-- {hypreal,hcomplex}_diff
  4503   star_n_mult <-- {hypreal,hcomplex}_mult
  4504   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4505   star_n_le <-- {hypreal,hypnat}_le
  4506   star_n_less <-- {hypreal,hypnat}_less
  4507   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4508   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4509   star_n_abs <-- hypreal_hrabs
  4510   star_n_divide <-- hcomplex_divide
  4511 
  4512   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4513   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4514   star_of_diff <-- hypreal_of_real_diff
  4515   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4516   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4517   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4518   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4519   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4520   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4521   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4522   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4523   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4524   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4525   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4526   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4527   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4528   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4529   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4530   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4531   star_of_power <-- hypreal_of_real_power
  4532   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4533 
  4534 * Hyperreal: new method "transfer" that implements the transfer
  4535 principle of nonstandard analysis. With a subgoal that mentions
  4536 nonstandard types like "'a star", the command "apply transfer"
  4537 replaces it with an equivalent one that mentions only standard types.
  4538 To be successful, all free variables must have standard types; non-
  4539 standard variables must have explicit universal quantifiers.
  4540 
  4541 * Hyperreal: A theory of Taylor series.
  4542 
  4543 
  4544 *** HOLCF ***
  4545 
  4546 * Discontinued special version of 'constdefs' (which used to support
  4547 continuous functions) in favor of the general Pure one with full
  4548 type-inference.
  4549 
  4550 * New simplification procedure for solving continuity conditions; it
  4551 is much faster on terms with many nested lambda abstractions (cubic
  4552 instead of exponential time).
  4553 
  4554 * New syntax for domain package: selector names are now optional.
  4555 Parentheses should be omitted unless argument is lazy, for example:
  4556 
  4557   domain 'a stream = cons "'a" (lazy "'a stream")
  4558 
  4559 * New command 'fixrec' for defining recursive functions with pattern
  4560 matching; defining multiple functions with mutual recursion is also
  4561 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4562 sinr, or any data constructor defined by the domain package. The given
  4563 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4564 syntax and examples.
  4565 
  4566 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4567 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4568 but the proof obligation additionally includes an admissibility
  4569 requirement. The packages generate instances of class cpo or pcpo,
  4570 with continuity and strictness theorems for Rep and Abs.
  4571 
  4572 * HOLCF: Many theorems have been renamed according to a more standard naming
  4573 scheme (INCOMPATIBILITY):
  4574 
  4575   foo_inject:  "foo$x = foo$y ==> x = y"
  4576   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4577   foo_less:    "(foo$x << foo$y) = (x << y)"
  4578   foo_strict:  "foo$UU = UU"
  4579   foo_defined: "... ==> foo$x ~= UU"
  4580   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4581 
  4582 
  4583 *** ZF ***
  4584 
  4585 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4586 including the First Isomorphism Theorem (on quotienting by the kernel
  4587 of a homomorphism).
  4588 
  4589 * ZF/Simplifier: install second copy of type solver that actually
  4590 makes use of TC rules declared to Isar proof contexts (or locales);
  4591 the old version is still required for ML proof scripts.
  4592 
  4593 
  4594 *** Cube ***
  4595 
  4596 * Converted to Isar theory format; use locales instead of axiomatic
  4597 theories.
  4598 
  4599 
  4600 *** ML ***
  4601 
  4602 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4603 for ||>, ||>>, |>>,
  4604 
  4605 * Pure/library.ML no longer defines its own option datatype, but uses
  4606 that of the SML basis, which has constructors NONE and SOME instead of
  4607 None and Some, as well as exception Option.Option instead of OPTION.
  4608 The functions the, if_none, is_some, is_none have been adapted
  4609 accordingly, while Option.map replaces apsome.
  4610 
  4611 * Pure/library.ML: the exception LIST has been given up in favour of
  4612 the standard exceptions Empty and Subscript, as well as
  4613 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4614 superceded by the standard hd and tl functions etc.
  4615 
  4616 A number of basic list functions are no longer exported to the ML
  4617 toplevel, as they are variants of predefined functions.  The following
  4618 suggests how one can translate existing code:
  4619 
  4620     rev_append xs ys = List.revAppend (xs, ys)
  4621     nth_elem (i, xs) = List.nth (xs, i)
  4622     last_elem xs = List.last xs
  4623     flat xss = List.concat xss
  4624     seq fs = List.app fs
  4625     partition P xs = List.partition P xs
  4626     mapfilter f xs = List.mapPartial f xs
  4627 
  4628 * Pure/library.ML: several combinators for linear functional
  4629 transformations, notably reverse application and composition:
  4630 
  4631   x |> f                f #> g
  4632   (x, y) |-> f          f #-> g
  4633 
  4634 * Pure/library.ML: introduced/changed precedence of infix operators:
  4635 
  4636   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4637   infix 2 ?;
  4638   infix 3 o oo ooo oooo;
  4639   infix 4 ~~ upto downto;
  4640 
  4641 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4642 infix operators.
  4643 
  4644 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4645 fold_map support linear functional transformations and nesting.  For
  4646 example:
  4647 
  4648   fold f [x1, ..., xN] y =
  4649     y |> f x1 |> ... |> f xN
  4650 
  4651   (fold o fold) f [xs1, ..., xsN] y =
  4652     y |> fold f xs1 |> ... |> fold f xsN
  4653 
  4654   fold f [x1, ..., xN] =
  4655     f x1 #> ... #> f xN
  4656 
  4657   (fold o fold) f [xs1, ..., xsN] =
  4658     fold f xs1 #> ... #> fold f xsN
  4659 
  4660 * Pure/library.ML: the following selectors on type 'a option are
  4661 available:
  4662 
  4663   the:               'a option -> 'a  (*partial*)
  4664   these:             'a option -> 'a  where 'a = 'b list
  4665   the_default: 'a -> 'a option -> 'a
  4666   the_list:          'a option -> 'a list
  4667 
  4668 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4669 basic operations for association lists, following natural argument
  4670 order; moreover the explicit equality predicate passed here avoids
  4671 potentially expensive polymorphic runtime equality checks.
  4672 The old functions may be expressed as follows:
  4673 
  4674   assoc = uncurry (AList.lookup (op =))
  4675   assocs = these oo AList.lookup (op =)
  4676   overwrite = uncurry (AList.update (op =)) o swap
  4677 
  4678 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4679 
  4680   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4681   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4682 
  4683 replacing make_keylist and keyfilter (occassionally used)
  4684 Naive rewrites:
  4685 
  4686   make_keylist = AList.make
  4687   keyfilter = AList.find (op =)
  4688 
  4689 * eq_fst and eq_snd now take explicit equality parameter, thus
  4690   avoiding eqtypes. Naive rewrites:
  4691 
  4692     eq_fst = eq_fst (op =)
  4693     eq_snd = eq_snd (op =)
  4694 
  4695 * Removed deprecated apl and apr (rarely used).
  4696   Naive rewrites:
  4697 
  4698     apl (n, op) =>>= curry op n
  4699     apr (op, m) =>>= fn n => op (n, m)
  4700 
  4701 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4702 provides a reasonably efficient light-weight implementation of sets as
  4703 lists.
  4704 
  4705 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4706 few new operations; existing lookup and update are now curried to
  4707 follow natural argument order (for use with fold etc.);
  4708 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4709 
  4710 * Pure/General: output via the Isabelle channels of
  4711 writeln/warning/error etc. is now passed through Output.output, with a
  4712 hook for arbitrary transformations depending on the print_mode
  4713 (cf. Output.add_mode -- the first active mode that provides a output
  4714 function wins).  Already formatted output may be embedded into further
  4715 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4716 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4717 accommodate easy composition of diagnostic messages etc.  Programmers
  4718 rarely need to care about Output.output or Output.raw at all, with
  4719 some notable exceptions: Output.output is required when bypassing the
  4720 standard channels (writeln etc.), or in token translations to produce
  4721 properly formatted results; Output.raw is required when capturing
  4722 already output material that will eventually be presented to the user
  4723 a second time.  For the default print mode, both Output.output and
  4724 Output.raw have no effect.
  4725 
  4726 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4727 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4728 cumulative results are displayed at the end of a batch session.
  4729 
  4730 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4731 replaced by File.platform_path and File.shell_path (with appropriate
  4732 hooks).  This provides a clean interface for unusual systems where the
  4733 internal and external process view of file names are different.
  4734 
  4735 * Pure: more efficient orders for basic syntactic entities: added
  4736 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4737 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4738 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4739 orders now -- potential INCOMPATIBILITY for code that depends on a
  4740 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4741 Library.sort_strings on result).
  4742 
  4743 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4744 fold_types traverse types/terms from left to right, observing natural
  4745 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4746 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4747 
  4748 * Pure: name spaces have been refined, with significant changes of the
  4749 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4750 to extern(_table).  The plain name entry path is superceded by a
  4751 general 'naming' context, which also includes the 'policy' to produce
  4752 a fully qualified name and external accesses of a fully qualified
  4753 name; NameSpace.extend is superceded by context dependent
  4754 Sign.declare_name.  Several theory and proof context operations modify
  4755 the naming context.  Especially note Theory.restore_naming and
  4756 ProofContext.restore_naming to get back to a sane state; note that
  4757 Theory.add_path is no longer sufficient to recover from
  4758 Theory.absolute_path in particular.
  4759 
  4760 * Pure: new flags short_names (default false) and unique_names
  4761 (default true) for controlling output of qualified names.  If
  4762 short_names is set, names are printed unqualified.  If unique_names is
  4763 reset, the name prefix is reduced to the minimum required to achieve
  4764 the original result when interning again, even if there is an overlap
  4765 with earlier declarations.
  4766 
  4767 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4768 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4769 (useful for printing error messages).  INCOMPATIBILITY.
  4770 
  4771 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4772 Theory.theory are now identified, referring to the universal
  4773 Context.theory (see Pure/context.ML).  Actual signature and theory
  4774 content is managed as theory data.  The old code and interfaces were
  4775 spread over many files and structures; the new arrangement introduces
  4776 considerable INCOMPATIBILITY to gain more clarity:
  4777 
  4778   Context -- theory management operations (name, identity, inclusion,
  4779     parents, ancestors, merge, etc.), plus generic theory data;
  4780 
  4781   Sign -- logical signature and syntax operations (declaring consts,
  4782     types, etc.), plus certify/read for common entities;
  4783 
  4784   Theory -- logical theory operations (stating axioms, definitions,
  4785     oracles), plus a copy of logical signature operations (consts,
  4786     types, etc.); also a few basic management operations (Theory.copy,
  4787     Theory.merge, etc.)
  4788 
  4789 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4790 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4791 for convenience -- they merely return the theory.
  4792 
  4793 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4794 
  4795 * Pure: the Isar proof context type is already defined early in Pure
  4796 as Context.proof (note that ProofContext.context and Proof.context are
  4797 aliases, where the latter is the preferred name).  This enables other
  4798 Isabelle components to refer to that type even before Isar is present.
  4799 
  4800 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4801 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4802 any of these kinds.  For example, Sign.intern typeK is now
  4803 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4804 Theory.hide_types.  Also note that former
  4805 Theory.hide_classes/types/consts are now
  4806 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4807 internalize their arguments!  INCOMPATIBILITY.
  4808 
  4809 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4810 datatype thmref (with constructors Name and NameSelection) instead of
  4811 plain string -- INCOMPATIBILITY;
  4812 
  4813 * Pure: cases produced by proof methods specify options, where NONE
  4814 means to remove case bindings -- INCOMPATIBILITY in
  4815 (RAW_)METHOD_CASES.
  4816 
  4817 * Pure: the following operations retrieve axioms or theorems from a
  4818 theory node or theory hierarchy, respectively:
  4819 
  4820   Theory.axioms_of: theory -> (string * term) list
  4821   Theory.all_axioms_of: theory -> (string * term) list
  4822   PureThy.thms_of: theory -> (string * thm) list
  4823   PureThy.all_thms_of: theory -> (string * thm) list
  4824 
  4825 * Pure: print_tac now outputs the goal through the trace channel.
  4826 
  4827 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4828 Reference Toplevel.debug (default false) controls detailed printing
  4829 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4830 controls execution profiling -- set to 1 for time and 2 for space
  4831 (both increase the runtime).
  4832 
  4833 * Isar session: The initial use of ROOT.ML is now always timed,
  4834 i.e. the log will show the actual process times, in contrast to the
  4835 elapsed wall-clock time that the outer shell wrapper produces.
  4836 
  4837 * Simplifier: improved handling of bound variables (nameless
  4838 representation, avoid allocating new strings).  Simprocs that invoke
  4839 the Simplifier recursively should use Simplifier.inherit_bounds to
  4840 avoid local name clashes.  Failure to do so produces warnings
  4841 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4842 for further details.
  4843 
  4844 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4845 bindings for all theorems stored within a given theory; this may help
  4846 in porting non-Isar theories to Isar ones, while keeping ML proof
  4847 scripts for the time being.
  4848 
  4849 * ML operator HTML.with_charset specifies the charset begin used for
  4850 generated HTML files.  For example:
  4851 
  4852   HTML.with_charset "utf-8" use_thy "Hebrew";
  4853   HTML.with_charset "utf-8" use_thy "Chinese";
  4854 
  4855 
  4856 *** System ***
  4857 
  4858 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4859 isabelle, isatool etc.).
  4860 
  4861 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4862 isatool doc, isatool mkdir, display_drafts etc.).
  4863 
  4864 * isatool usedir: option -f allows specification of the ML file to be
  4865 used by Isabelle; default is ROOT.ML.
  4866 
  4867 * New isatool version outputs the version identifier of the Isabelle
  4868 distribution being used.
  4869 
  4870 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4871 (containing Boolean satisfiability problems) into Isabelle/HOL
  4872 theories.
  4873 
  4874 
  4875 
  4876 New in Isabelle2004 (April 2004)
  4877 --------------------------------
  4878 
  4879 *** General ***
  4880 
  4881 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4882   Replaces linorder.ML.
  4883 
  4884 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4885   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4886   (\<a>...\<z>), are now considered normal letters, and can therefore
  4887   be used anywhere where an ASCII letter (a...zA...Z) has until
  4888   now. COMPATIBILITY: This obviously changes the parsing of some
  4889   terms, especially where a symbol has been used as a binder, say
  4890   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4891   as an identifier.  Fix it by inserting a space around former
  4892   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4893   existing theory and ML files.
  4894 
  4895 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4896 
  4897 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4898   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4899   a normal (but invisible) letter. For multiple letter subscripts repeat
  4900   \<^isub> like this: x\<^isub>1\<^isub>2.
  4901 
  4902 * Pure: There are now sub-/superscripts that can span more than one
  4903   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4904   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4905   superscript. The new control characters are not identifier parts.
  4906 
  4907 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4908   content of "..." to the latex file instead of \isacntrl... . The "..."
  4909   may consist of any printable characters excluding the end bracket >.
  4910 
  4911 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4912   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4913   declare constants "final", which prevents their being given a definition
  4914   later.  It is useful for constants whose behaviour is fixed axiomatically
  4915   rather than definitionally, such as the meta-logic connectives.
  4916 
  4917 * Pure: 'instance' now handles general arities with general sorts
  4918   (i.e. intersections of classes),
  4919 
  4920 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4921   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4922   It can be changed to alter the colors/layout of generated pages.
  4923 
  4924 
  4925 *** Isar ***
  4926 
  4927 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4928   cut_tac, subgoal_tac and thin_tac:
  4929   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4930     locales are no longer forced to write Isar proof scripts.
  4931     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4932     emulations.
  4933   - INCOMPATIBILITY: names of variables to be instantiated may no
  4934     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4935     This is consistent with the instantiation attribute "where".
  4936 
  4937 * Attributes "where" and "of":
  4938   - Now take type variables of instantiated theorem into account when reading
  4939     the instantiation string.  This fixes a bug that caused instantiated
  4940     theorems to have too special types in some circumstances.
  4941   - "where" permits explicit instantiations of type variables.
  4942 
  4943 * Calculation commands "moreover" and "also" no longer interfere with
  4944   current facts ("this"), admitting arbitrary combinations with "then"
  4945   and derived forms.
  4946 
  4947 * Locales:
  4948   - Goal statements involving the context element "includes" no longer
  4949     generate theorems with internal delta predicates (those ending on
  4950     "_axioms") in the premise.
  4951     Resolve particular premise with <locale>.intro to obtain old form.
  4952   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4953     specification and "includes" elements in goal statement.
  4954   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4955     [intro?] and [elim?] (respectively) by default.
  4956   - Experimental command for instantiation of locales in proof contexts:
  4957         instantiate <label>[<attrs>]: <loc>
  4958     Instantiates locale <loc> and adds all its theorems to the current context
  4959     taking into account their attributes.  Label and attrs are optional
  4960     modifiers, like in theorem declarations.  If present, names of
  4961     instantiated theorems are qualified with <label>, and the attributes
  4962     <attrs> are applied after any attributes these theorems might have already.
  4963       If the locale has assumptions, a chained fact of the form
  4964     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4965     are derived.  The command does not support old-style locales declared
  4966     with "locale (open)".
  4967       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4968 
  4969 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4970   (Isar) contexts.
  4971 
  4972 
  4973 *** HOL ***
  4974 
  4975 * Proof import: new image HOL4 contains the imported library from
  4976   the HOL4 system with about 2500 theorems. It is imported by
  4977   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4978   can be used like any other Isabelle image.  See
  4979   HOL/Import/HOL/README for more information.
  4980 
  4981 * Simplifier:
  4982   - Much improved handling of linear and partial orders.
  4983     Reasoners for linear and partial orders are set up for type classes
  4984     "linorder" and "order" respectively, and are added to the default simpset
  4985     as solvers.  This means that the simplifier can build transitivity chains
  4986     to solve goals from the assumptions.
  4987   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4988     of blast or auto after simplification become unnecessary because the goal
  4989     is solved by simplification already.
  4990 
  4991 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4992     all proved in axiomatic type classes for semirings, rings and fields.
  4993 
  4994 * Numerics:
  4995   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4996     now formalized using the Ring_and_Field theory mentioned above.
  4997   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4998     than before, because now they are set up once in a generic manner.
  4999   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5000     Look for the general versions in Ring_and_Field (and Power if they concern
  5001     exponentiation).
  5002 
  5003 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5004 
  5005 * Records:
  5006   - Record types are now by default printed with their type abbreviation
  5007     instead of the list of all field types. This can be configured via
  5008     the reference "print_record_type_abbr".
  5009   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5010     (not enabled by default).
  5011   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5012     EX x. x = sel r to True (not enabled by default).
  5013   - Tactic "record_split_simp_tac" to split and simplify records added.
  5014 
  5015 * 'specification' command added, allowing for definition by
  5016   specification.  There is also an 'ax_specification' command that
  5017   introduces the new constants axiomatically.
  5018 
  5019 * arith(_tac) is now able to generate counterexamples for reals as well.
  5020 
  5021 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5022 
  5023 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5024   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5025 
  5026 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5027   matrix theory to linear programming.
  5028 
  5029 * Unions and Intersections:
  5030   The latex output syntax of UN and INT has been changed
  5031   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5032   i.e. the index formulae has become a subscript.
  5033   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5034 
  5035 * Unions and Intersections over Intervals:
  5036   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5037   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5038   like in normal math, and corresponding versions for < and for intersection.
  5039 
  5040 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5041   lexicographic dictonary ordering has been added as "lexord".
  5042 
  5043 * ML: the legacy theory structures Int and List have been removed. They had
  5044   conflicted with ML Basis Library structures having the same names.
  5045 
  5046 * 'refute' command added to search for (finite) countermodels.  Only works
  5047   for a fragment of HOL.  The installation of an external SAT solver is
  5048   highly recommended.  See "HOL/Refute.thy" for details.
  5049 
  5050 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5051   formulae under an assignment of free variables to random values.
  5052   In contrast to 'refute', it can deal with inductive datatypes,
  5053   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5054   for examples.
  5055 
  5056 
  5057 *** HOLCF ***
  5058 
  5059 * Streams now come with concatenation and are part of the HOLCF image
  5060 
  5061 
  5062 
  5063 New in Isabelle2003 (May 2003)
  5064 ------------------------------
  5065 
  5066 *** General ***
  5067 
  5068 * Provers/simplifier:
  5069 
  5070   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5071     Assumptions are now subject to complete mutual simplification,
  5072     not just from left to right. The simplifier now preserves
  5073     the order of assumptions.
  5074 
  5075     Potential INCOMPATIBILITY:
  5076 
  5077     -- simp sometimes diverges where the old version did
  5078        not, e.g. invoking simp on the goal
  5079 
  5080         [| P (f x); y = x; f x = f y |] ==> Q
  5081 
  5082        now gives rise to the infinite reduction sequence
  5083 
  5084         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5085 
  5086        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5087        kind of problem.
  5088 
  5089     -- Tactics combining classical reasoner and simplification (such as auto)
  5090        are also affected by this change, because many of them rely on
  5091        simp. They may sometimes diverge as well or yield a different numbers
  5092        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5093        in case of problems. Sometimes subsequent calls to the classical
  5094        reasoner will fail because a preceeding call to the simplifier too
  5095        eagerly simplified the goal, e.g. deleted redundant premises.
  5096 
  5097   - The simplifier trace now shows the names of the applied rewrite rules
  5098 
  5099   - You can limit the number of recursive invocations of the simplifier
  5100     during conditional rewriting (where the simplifie tries to solve the
  5101     conditions before applying the rewrite rule):
  5102     ML "simp_depth_limit := n"
  5103     where n is an integer. Thus you can force termination where previously
  5104     the simplifier would diverge.
  5105 
  5106   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5107 
  5108   - No longer aborts on failed congruence proof.  Instead, the
  5109     congruence is ignored.
  5110 
  5111 * Pure: New generic framework for extracting programs from constructive
  5112   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5113   as HOL/Extraction for some case studies.
  5114 
  5115 * Pure: The main goal of the proof state is no longer shown by default, only
  5116 the subgoals. This behaviour is controlled by a new flag.
  5117    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5118 (ML: Proof.show_main_goal).
  5119 
  5120 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5121 rules whose conclusion matches subgoal 1:
  5122       PG menu: Isabelle/Isar -> Show me -> matching rules
  5123 The rules are ordered by how closely they match the subgoal.
  5124 In particular, rules that solve a subgoal outright are displayed first
  5125 (or rather last, the way they are printed).
  5126 (ML: ProofGeneral.print_intros())
  5127 
  5128 * Pure: New flag trace_unify_fail causes unification to print
  5129 diagnostic information (PG: in trace buffer) when it fails. This is
  5130 useful for figuring out why single step proofs like rule, erule or
  5131 assumption failed.
  5132 
  5133 * Pure: Locale specifications now produce predicate definitions
  5134 according to the body of text (covering assumptions modulo local
  5135 definitions); predicate "loc_axioms" covers newly introduced text,
  5136 while "loc" is cumulative wrt. all included locale expressions; the
  5137 latter view is presented only on export into the global theory
  5138 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5139 on the old view without predicates;
  5140 
  5141 * Pure: predefined locales "var" and "struct" are useful for sharing
  5142 parameters (as in CASL, for example); just specify something like
  5143 ``var x + var y + struct M'' as import;
  5144 
  5145 * Pure: improved thms_containing: proper indexing of facts instead of
  5146 raw theorems; check validity of results wrt. current name space;
  5147 include local facts of proof configuration (also covers active
  5148 locales), cover fixed variables in index; may use "_" in term
  5149 specification; an optional limit for the number of printed facts may
  5150 be given (the default is 40);
  5151 
  5152 * Pure: disallow duplicate fact bindings within new-style theory files
  5153 (batch-mode only);
  5154 
  5155 * Provers: improved induct method: assumptions introduced by case
  5156 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5157 the goal statement); "foo" still refers to all facts collectively;
  5158 
  5159 * Provers: the function blast.overloaded has been removed: all constants
  5160 are regarded as potentially overloaded, which improves robustness in exchange
  5161 for slight decrease in efficiency;
  5162 
  5163 * Provers/linorder: New generic prover for transitivity reasoning over
  5164 linear orders.  Note: this prover is not efficient!
  5165 
  5166 * Isar: preview of problems to finish 'show' now produce an error
  5167 rather than just a warning (in interactive mode);
  5168 
  5169 
  5170 *** HOL ***
  5171 
  5172 * arith(_tac)
  5173 
  5174  - Produces a counter example if it cannot prove a goal.
  5175    Note that the counter example may be spurious if the goal is not a formula
  5176    of quantifier-free linear arithmetic.
  5177    In ProofGeneral the counter example appears in the trace buffer.
  5178 
  5179  - Knows about div k and mod k where k is a numeral of type nat or int.
  5180 
  5181  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5182    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5183    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5184 
  5185 * simp's arithmetic capabilities have been enhanced a bit: it now
  5186 takes ~= in premises into account (by performing a case split);
  5187 
  5188 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5189 are distributed over a sum of terms;
  5190 
  5191 * New tactic "trans_tac" and method "trans" instantiate
  5192 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5193 "<=", "<" and "=").
  5194 
  5195 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5196 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5197 
  5198 * 'typedef' command has new option "open" to suppress the set
  5199 definition;
  5200 
  5201 * functions Min and Max on finite sets have been introduced (theory
  5202 Finite_Set);
  5203 
  5204 * attribute [symmetric] now works for relations as well; it turns
  5205 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5206 
  5207 * induct over a !!-quantified statement (say !!x1..xn):
  5208   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5209 
  5210 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5211 %x. None. Warning: empty_def now refers to the previously hidden definition
  5212 of the empty set.
  5213 
  5214 * Algebra: formalization of classical algebra.  Intended as base for
  5215 any algebraic development in Isabelle.  Currently covers group theory
  5216 (up to Sylow's theorem) and ring theory (Universal Property of
  5217 Univariate Polynomials).  Contributions welcome;
  5218 
  5219 * GroupTheory: deleted, since its material has been moved to Algebra;
  5220 
  5221 * Complex: new directory of the complex numbers with numeric constants,
  5222 nonstandard complex numbers, and some complex analysis, standard and
  5223 nonstandard (Jacques Fleuriot);
  5224 
  5225 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5226 
  5227 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5228 Fleuriot);
  5229 
  5230 * Real/HahnBanach: updated and adapted to locales;
  5231 
  5232 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5233 Gray and Kramer);
  5234 
  5235 * UNITY: added the Meier-Sanders theory of progress sets;
  5236 
  5237 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5238 as abstract algorithms, instantiated to the JVM;
  5239 
  5240 * Bali: Java source language formalization. Type system, operational
  5241 semantics, axiomatic semantics. Supported language features:
  5242 classes, interfaces, objects,virtual methods, static methods,
  5243 static/instance fields, arrays, access modifiers, definite
  5244 assignment, exceptions.
  5245 
  5246 
  5247 *** ZF ***
  5248 
  5249 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5250 universe, etc.);
  5251 
  5252 * Main ZF: virtually all theories converted to new-style format;
  5253 
  5254 
  5255 *** ML ***
  5256 
  5257 * Pure: Tactic.prove provides sane interface for internal proofs;
  5258 omits the infamous "standard" operation, so this is more appropriate
  5259 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5260 
  5261 * Pure: improved error reporting of simprocs;
  5262 
  5263 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5264 up simprocs;
  5265 
  5266 
  5267 *** Document preparation ***
  5268 
  5269 * uses \par instead of \\ for line breaks in theory text. This may
  5270 shift some page breaks in large documents. To get the old behaviour
  5271 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5272 
  5273 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5274 other packages
  5275 
  5276 * \<euro> now needs package babel/greek instead of marvosym (which
  5277 broke \Rightarrow)
  5278 
  5279 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5280 textcomp package)
  5281 
  5282 
  5283 
  5284 New in Isabelle2002 (March 2002)
  5285 --------------------------------
  5286 
  5287 *** Document preparation ***
  5288 
  5289 * greatly simplified document preparation setup, including more
  5290 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5291 instructive isatool mkdir; users should basically be able to get
  5292 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5293 users may run a separate document processing stage manually like this:
  5294 "isatool usedir -D output HOL Test && isatool document Test/output";
  5295 
  5296 * theory dependency graph may now be incorporated into documents;
  5297 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5298 with \includegraphics of LaTeX;
  5299 
  5300 * proper spacing of consecutive markup elements, especially text
  5301 blocks after section headings;
  5302 
  5303 * support bold style (for single symbols only), input syntax is like
  5304 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5305 
  5306 * \<bullet> is now output as bold \cdot by default, which looks much
  5307 better in printed text;
  5308 
  5309 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5310 note that these symbols are currently unavailable in Proof General /
  5311 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5312 
  5313 * isatool latex no longer depends on changed TEXINPUTS, instead
  5314 isatool document copies the Isabelle style files to the target
  5315 location;
  5316 
  5317 
  5318 *** Isar ***
  5319 
  5320 * Pure/Provers: improved proof by cases and induction;
  5321   - 'case' command admits impromptu naming of parameters (such as
  5322     "case (Suc n)");
  5323   - 'induct' method divinates rule instantiation from the inductive
  5324     claim; no longer requires excessive ?P bindings for proper
  5325     instantiation of cases;
  5326   - 'induct' method properly enumerates all possibilities of set/type
  5327     rules; as a consequence facts may be also passed through *type*
  5328     rules without further ado;
  5329   - 'induct' method now derives symbolic cases from the *rulified*
  5330     rule (before it used to rulify cases stemming from the internal
  5331     atomized version); this means that the context of a non-atomic
  5332     statement becomes is included in the hypothesis, avoiding the
  5333     slightly cumbersome show "PROP ?case" form;
  5334   - 'induct' may now use elim-style induction rules without chaining
  5335     facts, using ``missing'' premises from the goal state; this allows
  5336     rules stemming from inductive sets to be applied in unstructured
  5337     scripts, while still benefitting from proper handling of non-atomic
  5338     statements; NB: major inductive premises need to be put first, all
  5339     the rest of the goal is passed through the induction;
  5340   - 'induct' proper support for mutual induction involving non-atomic
  5341     rule statements (uses the new concept of simultaneous goals, see
  5342     below);
  5343   - append all possible rule selections, but only use the first
  5344     success (no backtracking);
  5345   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5346   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5347   - added 'print_induct_rules' (covered by help item in recent Proof
  5348     General versions);
  5349   - moved induct/cases attributes to Pure, methods to Provers;
  5350   - generic method setup instantiated for FOL and HOL;
  5351 
  5352 * Pure: support multiple simultaneous goal statements, for example
  5353 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5354 meta-level mechanism, this acts as if several individual goals had
  5355 been stated separately; in particular common proof methods need to be
  5356 repeated in order to cover all claims; note that a single elimination
  5357 step is *not* sufficient to establish the two conjunctions, so this
  5358 fails:
  5359 
  5360   assume "A & B" then have A and B ..   (*".." fails*)
  5361 
  5362 better use "obtain" in situations as above; alternative refer to
  5363 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5364 
  5365 * Pure: proper integration with ``locales''; unlike the original
  5366 version by Florian Kammller, Isar locales package high-level proof
  5367 contexts rather than raw logical ones (e.g. we admit to include
  5368 attributes everywhere); operations on locales include merge and
  5369 rename; support for implicit arguments (``structures''); simultaneous
  5370 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5371 some examples;
  5372 
  5373 * Pure: the following commands have been ``localized'', supporting a
  5374 target locale specification "(in name)": 'lemma', 'theorem',
  5375 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5376 stored both within the locale and at the theory level (exported and
  5377 qualified by the locale name);
  5378 
  5379 * Pure: theory goals may now be specified in ``long'' form, with
  5380 ad-hoc contexts consisting of arbitrary locale elements. for example
  5381 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5382 definitions may be given, too); the result is a meta-level rule with
  5383 the context elements being discharged in the obvious way;
  5384 
  5385 * Pure: new proof command 'using' allows to augment currently used
  5386 facts after a goal statement ('using' is syntactically analogous to
  5387 'apply', but acts on the goal's facts only); this allows chained facts
  5388 to be separated into parts given before and after a claim, as in
  5389 ``from a and b have C using d and e <proof>'';
  5390 
  5391 * Pure: renamed "antecedent" case to "rule_context";
  5392 
  5393 * Pure: new 'judgment' command records explicit information about the
  5394 object-logic embedding (used by several tools internally); no longer
  5395 use hard-wired "Trueprop";
  5396 
  5397 * Pure: added 'corollary' command;
  5398 
  5399 * Pure: fixed 'token_translation' command;
  5400 
  5401 * Pure: removed obsolete 'exported' attribute;
  5402 
  5403 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5404 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5405 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5406 
  5407 * Pure: method 'atomize' presents local goal premises as object-level
  5408 statements (atomic meta-level propositions); setup controlled via
  5409 rewrite rules declarations of 'atomize' attribute; example
  5410 application: 'induct' method with proper rule statements in improper
  5411 proof *scripts*;
  5412 
  5413 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5414 now consider the syntactic context of assumptions, giving a better
  5415 chance to get type-inference of the arguments right (this is
  5416 especially important for locales);
  5417 
  5418 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5419 mode;
  5420 
  5421 * Pure/obtain: the formal conclusion "thesis", being marked as
  5422 ``internal'', may no longer be reference directly in the text;
  5423 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5424 situations;
  5425 
  5426 * Pure: generic 'sym' attribute which declares a rule both as pure
  5427 'elim?' and for the 'symmetric' operation;
  5428 
  5429 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5430 text; the fixed correlation with particular command syntax has been
  5431 discontinued;
  5432 
  5433 * Pure: new method 'rules' is particularly well-suited for proof
  5434 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5435 but often produces more compact proof terms with less detours;
  5436 
  5437 * Pure/Provers/classical: simplified integration with pure rule
  5438 attributes and methods; the classical "intro?/elim?/dest?"
  5439 declarations coincide with the pure ones; the "rule" method no longer
  5440 includes classically swapped intros; "intro" and "elim" methods no
  5441 longer pick rules from the context; also got rid of ML declarations
  5442 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5443 INCOMPATIBILITY;
  5444 
  5445 * Provers/classical: attribute 'swapped' produces classical inversions
  5446 of introduction rules;
  5447 
  5448 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5449 rules instead of full simplifier context; 'iff' attribute handles
  5450 conditional rules;
  5451 
  5452 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5453 
  5454 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5455 "(permissive)" option to recover old behavior;
  5456 
  5457 * HOL: 'inductive' no longer features separate (collective) attributes
  5458 for 'intros' (was found too confusing);
  5459 
  5460 * HOL: properly declared induction rules less_induct and
  5461 wf_induct_rule;
  5462 
  5463 
  5464 *** HOL ***
  5465 
  5466 * HOL: moved over to sane numeral syntax; the new policy is as
  5467 follows:
  5468 
  5469   - 0 and 1 are polymorphic constants, which are defined on any
  5470   numeric type (nat, int, real etc.);
  5471 
  5472   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5473   binary representation internally;
  5474 
  5475   - type nat has special constructor Suc, and generally prefers Suc 0
  5476   over 1::nat and Suc (Suc 0) over 2::nat;
  5477 
  5478 This change may cause significant problems of INCOMPATIBILITY; here
  5479 are some hints on converting existing sources:
  5480 
  5481   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5482   entities, so expressions involving "-" (unary or binary minus) need
  5483   to be spaced properly;
  5484 
  5485   - existing occurrences of "1" may need to be constraint "1::nat" or
  5486   even replaced by Suc 0; similar for old "2";
  5487 
  5488   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5489 
  5490   - remove all special provisions on numerals in proofs;
  5491 
  5492 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5493 representation (depends on bin_arith_simps in the default context);
  5494 
  5495 * HOL: symbolic syntax for x^2 (numeral 2);
  5496 
  5497 * HOL: the class of all HOL types is now called "type" rather than
  5498 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5499 in axclass/classes, instance/arities, and (usually rare) occurrences
  5500 in typings (of consts etc.); internally the class is called
  5501 "HOL.type", ML programs should refer to HOLogic.typeS;
  5502 
  5503 * HOL/record package improvements:
  5504   - new derived operations "fields" to build a partial record section,
  5505     "extend" to promote a fixed record to a record scheme, and
  5506     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5507     declared as simp by default;
  5508   - shared operations ("more", "fields", etc.) now need to be always
  5509     qualified) --- potential INCOMPATIBILITY;
  5510   - removed "make_scheme" operations (use "make" with "extend") --
  5511     INCOMPATIBILITY;
  5512   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5513   - provides cases/induct rules for use with corresponding Isar
  5514     methods (for concrete records, record schemes, concrete more
  5515     parts, and schematic more parts -- in that order);
  5516   - internal definitions directly based on a light-weight abstract
  5517     theory of product types over typedef rather than datatype;
  5518 
  5519 * HOL: generic code generator for generating executable ML code from
  5520 specifications; specific support for HOL constructs such as inductive
  5521 datatypes and sets, as well as recursive functions; can be invoked
  5522 via 'generate_code' theory section;
  5523 
  5524 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5525 
  5526 * HOL: consolidated and renamed several theories.  In particular:
  5527         Ord.thy has been absorbed into HOL.thy
  5528         String.thy has been absorbed into List.thy
  5529 
  5530 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5531 (beware of argument permutation!);
  5532 
  5533 * HOL: linorder_less_split superseded by linorder_cases;
  5534 
  5535 * HOL/List: "nodups" renamed to "distinct";
  5536 
  5537 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5538 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5539   - Ex_def has changed, now need to use some_eq_ex
  5540 
  5541 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5542 in this (rare) case use:
  5543 
  5544   delSWrapper "split_all_tac"
  5545   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5546 
  5547 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5548 MAY FAIL;
  5549 
  5550 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5551 Isabelle's type classes, ^ on functions and relations has too general
  5552 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5553 necessary to attach explicit type constraints;
  5554 
  5555 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5556 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5557 renamed accordingly (eg "compI" -> "rel_compI").
  5558 
  5559 * HOL: syntax translations now work properly with numerals and records
  5560 expressions;
  5561 
  5562 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5563 of "lam" -- INCOMPATIBILITY;
  5564 
  5565 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5566 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5567 renamed "Product_Type.unit";
  5568 
  5569 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5570 
  5571 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5572 the "cases" method);
  5573 
  5574 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5575 Florian Kammller);
  5576 
  5577 * HOL/IMP: updated and converted to new-style theory format; several
  5578 parts turned into readable document, with proper Isar proof texts and
  5579 some explanations (by Gerwin Klein);
  5580 
  5581 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5582 
  5583 * HOL-Hyperreal is now a logic image;
  5584 
  5585 
  5586 *** HOLCF ***
  5587 
  5588 * Isar: consts/constdefs supports mixfix syntax for continuous
  5589 operations;
  5590 
  5591 * Isar: domain package adapted to new-style theory format, e.g. see
  5592 HOLCF/ex/Dnat.thy;
  5593 
  5594 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5595 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5596 lift.induct_tac, always use UU instead of Undef;
  5597 
  5598 * HOLCF/IMP: updated and converted to new-style theory;
  5599 
  5600 
  5601 *** ZF ***
  5602 
  5603 * Isar: proper integration of logic-specific tools and packages,
  5604 including theory commands '(co)inductive', '(co)datatype',
  5605 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5606 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5607 
  5608 * theory Main no longer includes AC; for the Axiom of Choice, base
  5609 your theory on Main_ZFC;
  5610 
  5611 * the integer library now covers quotients and remainders, with many
  5612 laws relating division to addition, multiplication, etc.;
  5613 
  5614 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5615 typeless version of the formalism;
  5616 
  5617 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5618 format;
  5619 
  5620 * ZF/Induct: new directory for examples of inductive definitions,
  5621 including theory Multiset for multiset orderings; converted to
  5622 new-style theory format;
  5623 
  5624 * ZF: many new theorems about lists, ordinals, etc.;
  5625 
  5626 
  5627 *** General ***
  5628 
  5629 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5630 variable proof controls level of detail: 0 = no proofs (only oracle
  5631 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5632 also ref manual for further ML interfaces;
  5633 
  5634 * Pure/axclass: removed obsolete ML interface
  5635 goal_subclass/goal_arity;
  5636 
  5637 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5638 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5639 separate tokens, so expressions involving minus need to be spaced
  5640 properly;
  5641 
  5642 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5643 rather than "infixl" or "infixr";
  5644 
  5645 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5646 sort constraint specifications in type inference; e.g. "x::_::foo"
  5647 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5648 type variable);
  5649 
  5650 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5651 control output of nested => (types); the default behavior is
  5652 "type_brackets";
  5653 
  5654 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5655 tokens into AST constants;
  5656 
  5657 * Pure/syntax: prefer later declarations of translations and print
  5658 translation functions; potential INCOMPATIBILITY: need to reverse
  5659 multiple declarations for same syntax element constant;
  5660 
  5661 * Pure/show_hyps reset by default (in accordance to existing Isar
  5662 practice);
  5663 
  5664 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5665 addSafter;
  5666 
  5667 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5668 as well;
  5669 
  5670 * system: tested support for MacOS X; should be able to get Isabelle +
  5671 Proof General to work in a plain Terminal after installing Poly/ML
  5672 (e.g. from the Isabelle distribution area) and GNU bash alone
  5673 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5674 support requires further installations, e.g. from
  5675 http://fink.sourceforge.net/);
  5676 
  5677 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5678 
  5679 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5680 of 40 MB), cf. ML_OPTIONS;
  5681 
  5682 * system: Proof General keywords specification is now part of the
  5683 Isabelle distribution (see etc/isar-keywords.el);
  5684 
  5685 * system: support for persistent Proof General sessions (refrain from
  5686 outdating all loaded theories on startup); user may create writable
  5687 logic images like this: ``isabelle -q HOL Test'';
  5688 
  5689 * system: smart selection of Isabelle process versus Isabelle
  5690 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5691 run both "isabelle" and "Isabelle" even if file names are badly
  5692 damaged (executable inspects the case of the first letter of its own
  5693 name); added separate "isabelle-process" and "isabelle-interface";
  5694 
  5695 * system: refrain from any attempt at filtering input streams; no
  5696 longer support ``8bit'' encoding of old isabelle font, instead proper
  5697 iso-latin characters may now be used; the related isatools
  5698 "symbolinput" and "nonascii" have disappeared as well;
  5699 
  5700 * system: removed old "xterm" interface (the print modes "xterm" and
  5701 "xterm_color" are still available for direct use in a suitable
  5702 terminal);
  5703 
  5704 
  5705 
  5706 New in Isabelle99-2 (February 2001)
  5707 -----------------------------------
  5708 
  5709 *** Overview of INCOMPATIBILITIES ***
  5710 
  5711 * HOL: please note that theories in the Library and elsewhere often use the
  5712 new-style (Isar) format; to refer to their theorems in an ML script you must
  5713 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5714 
  5715 * HOL: inductive package no longer splits induction rule aggressively,
  5716 but only as far as specified by the introductions given; the old
  5717 format may be recovered via ML function complete_split_rule or attribute
  5718 'split_rule (complete)';
  5719 
  5720 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5721 gfp_Tarski to gfp_unfold;
  5722 
  5723 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5724 
  5725 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5726 relation); infix "^^" has been renamed "``"; infix "``" has been
  5727 renamed "`"; "univalent" has been renamed "single_valued";
  5728 
  5729 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5730 operation;
  5731 
  5732 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5733 
  5734 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5735 
  5736 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5737 consequence, it is no longer monotonic wrt. the local goal context
  5738 (which is now passed through the inductive cases);
  5739 
  5740 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5741 \<gg> to \<ggreater>;
  5742 
  5743 
  5744 *** Document preparation ***
  5745 
  5746 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5747 available: are "it" for near math-mode best-style output, "sl" for
  5748 slanted text style, and "tt" for plain type-writer; if no
  5749 \isabellestyle command is given, output is according to slanted
  5750 type-writer);
  5751 
  5752 * support sub/super scripts (for single symbols only), input syntax is
  5753 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5754 
  5755 * some more standard symbols; see Appendix A of the system manual for
  5756 the complete list of symbols defined in isabellesym.sty;
  5757 
  5758 * improved isabelle style files; more abstract symbol implementation
  5759 (should now use \isamath{...} and \isatext{...} in custom symbol
  5760 definitions);
  5761 
  5762 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5763 state; Note that presentation of goal states does not conform to
  5764 actual human-readable proof documents.  Please do not include goal
  5765 states into document output unless you really know what you are doing!
  5766 
  5767 * proper indentation of antiquoted output with proportional LaTeX
  5768 fonts;
  5769 
  5770 * no_document ML operator temporarily disables LaTeX document
  5771 generation;
  5772 
  5773 * isatool unsymbolize tunes sources for plain ASCII communication;
  5774 
  5775 
  5776 *** Isar ***
  5777 
  5778 * Pure: Isar now suffers initial goal statements to contain unbound
  5779 schematic variables (this does not conform to actual readable proof
  5780 documents, due to unpredictable outcome and non-compositional proof
  5781 checking); users who know what they are doing may use schematic goals
  5782 for Prolog-style synthesis of proven results;
  5783 
  5784 * Pure: assumption method (an implicit finishing) now handles actual
  5785 rules as well;
  5786 
  5787 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5788 initial goal, declare "that" only as Pure intro (only for single
  5789 steps); the "that" rule assumption may now be involved in implicit
  5790 finishing, thus ".." becomes a feasible for trivial obtains;
  5791 
  5792 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5793 instance proofs may be performed by "..";
  5794 
  5795 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5796 statements as well;
  5797 
  5798 * Pure: more robust selection of calculational rules;
  5799 
  5800 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5801 rule (as well as the assumption rule);
  5802 
  5803 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5804 lemmas, using the graph browser tool;
  5805 
  5806 * Pure: predict failure of "show" in interactive mode;
  5807 
  5808 * Pure: 'thms_containing' now takes actual terms as arguments;
  5809 
  5810 * HOL: improved method 'induct' --- now handles non-atomic goals
  5811 (potential INCOMPATIBILITY); tuned error handling;
  5812 
  5813 * HOL: cases and induct rules now provide explicit hints about the
  5814 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5815 any remaining facts are inserted into the goal verbatim;
  5816 
  5817 * HOL: local contexts (aka cases) may now contain term bindings as
  5818 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5819 the result to be shown in each case;
  5820 
  5821 * HOL: added 'recdef_tc' command;
  5822 
  5823 * isatool convert assists in eliminating legacy ML scripts;
  5824 
  5825 
  5826 *** HOL ***
  5827 
  5828 * HOL/Library: a collection of generic theories to be used together
  5829 with main HOL; the theory loader path already includes this directory
  5830 by default; the following existing theories have been moved here:
  5831 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5832 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5833 
  5834 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5835 modelling and verification task performed in Isabelle/HOL +
  5836 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5837 
  5838 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5839 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5840 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5841 'domain', this makes the theory consistent with mathematical
  5842 literature;
  5843 
  5844 * HOL basics: added overloaded operations "inverse" and "divide"
  5845 (infix "/"), syntax for generic "abs" operation, generic summation
  5846 operator \<Sum>;
  5847 
  5848 * HOL/typedef: simplified package, provide more useful rules (see also
  5849 HOL/subset.thy);
  5850 
  5851 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5852 now expressed as a proper nested rule (old-style tactic scripts may
  5853 require atomize_strip_tac to cope with non-atomic premises);
  5854 
  5855 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5856 to "split_conv" (old name still available for compatibility);
  5857 
  5858 * HOL: improved concrete syntax for strings (e.g. allows translation
  5859 rules with string literals);
  5860 
  5861 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5862  and Fleuriot's mechanization of analysis, including the transcendental
  5863  functions for the reals;
  5864 
  5865 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5866 
  5867 
  5868 *** CTT ***
  5869 
  5870 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5871 "lam" is displayed as TWO lambda-symbols
  5872 
  5873 * CTT: theory Main now available, containing everything (that is, Bool
  5874 and Arith);
  5875 
  5876 
  5877 *** General ***
  5878 
  5879 * Pure: the Simplifier has been implemented properly as a derived rule
  5880 outside of the actual kernel (at last!); the overall performance
  5881 penalty in practical applications is about 50%, while reliability of
  5882 the Isabelle inference kernel has been greatly improved;
  5883 
  5884 * print modes "brackets" and "no_brackets" control output of nested =>
  5885 (types) and ==> (props); the default behaviour is "brackets";
  5886 
  5887 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5888 as assumptions as well;
  5889 
  5890 * system: support Poly/ML 4.0;
  5891 
  5892 * system: isatool install handles KDE version 1 or 2;
  5893 
  5894 
  5895 
  5896 New in Isabelle99-1 (October 2000)
  5897 ----------------------------------
  5898 
  5899 *** Overview of INCOMPATIBILITIES ***
  5900 
  5901 * HOL: simplification of natural numbers is much changed; to partly
  5902 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5903 issue the following ML commands:
  5904 
  5905   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5906   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5907 
  5908 * HOL: simplification no longer dives into case-expressions; this is
  5909 controlled by "t.weak_case_cong" for each datatype t;
  5910 
  5911 * HOL: nat_less_induct renamed to less_induct;
  5912 
  5913 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5914 fixsome to patch .thy and .ML sources automatically;
  5915 
  5916   select_equality  -> some_equality
  5917   select_eq_Ex     -> some_eq_ex
  5918   selectI2EX       -> someI2_ex
  5919   selectI2         -> someI2
  5920   selectI          -> someI
  5921   select1_equality -> some1_equality
  5922   Eps_sym_eq       -> some_sym_eq_trivial
  5923   Eps_eq           -> some_eq_trivial
  5924 
  5925 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5926 
  5927 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5928 instead);
  5929 
  5930 * HOL: the recursion equations generated by 'recdef' are now called
  5931 f.simps instead of f.rules;
  5932 
  5933 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5934 
  5935 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5936 sometimes be needed;
  5937 
  5938 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5939 
  5940 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5941 
  5942 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5943 product is now "<*>" instead of "Times"; the lexicographic product is
  5944 now "<*lex*>" instead of "**";
  5945 
  5946 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5947 of main HOL, but was unused); better use HOL's datatype package;
  5948 
  5949 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5950 the old syntax may be recovered as follows:
  5951 
  5952   syntax (symbols)
  5953     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5954       (infixl "\\<oplus>" 100)
  5955 
  5956 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5957 
  5958 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5959 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5960 internally;
  5961 
  5962 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5963 changed from A/r to A//r;
  5964 
  5965 * ZF: new treatment of arithmetic (nat & int) may break some old
  5966 proofs;
  5967 
  5968 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5969 rulify -> rule_format, elimify -> elim_format, ...);
  5970 
  5971 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5972 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5973 should have to change intro!! to intro? only); replaced "delrule" by
  5974 "rule del";
  5975 
  5976 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5977 
  5978 * Provers: strengthened force_tac by using new first_best_tac;
  5979 
  5980 * LaTeX document preparation: several changes of isabelle.sty (see
  5981 lib/texinputs);
  5982 
  5983 
  5984 *** Document preparation ***
  5985 
  5986 * formal comments (text blocks etc.) in new-style theories may now
  5987 contain antiquotations of thm/prop/term/typ/text to be presented
  5988 according to latex print mode; concrete syntax is like this:
  5989 @{term[show_types] "f(x) = a + x"};
  5990 
  5991 * isatool mkdir provides easy setup of Isabelle session directories,
  5992 including proper document sources;
  5993 
  5994 * generated LaTeX sources are now deleted after successful run
  5995 (isatool document -c); may retain a copy somewhere else via -D option
  5996 of isatool usedir;
  5997 
  5998 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5999 style files, achieving self-contained LaTeX sources and simplifying
  6000 LaTeX debugging;
  6001 
  6002 * old-style theories now produce (crude) LaTeX output as well;
  6003 
  6004 * browser info session directories are now self-contained (may be put
  6005 on WWW server seperately); improved graphs of nested sessions; removed
  6006 graph for 'all sessions';
  6007 
  6008 * several improvements in isabelle style files; \isabellestyle{it}
  6009 produces fake math mode output; \isamarkupheader is now \section by
  6010 default; see lib/texinputs/isabelle.sty etc.;
  6011 
  6012 
  6013 *** Isar ***
  6014 
  6015 * Isar/Pure: local results and corresponding term bindings are now
  6016 subject to Hindley-Milner polymorphism (similar to ML); this
  6017 accommodates incremental type-inference very nicely;
  6018 
  6019 * Isar/Pure: new derived language element 'obtain' supports
  6020 generalized existence reasoning;
  6021 
  6022 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6023 support accumulation of results, without applying any rules yet;
  6024 useful to collect intermediate results without explicit name
  6025 references, and for use with transitivity rules with more than 2
  6026 premises;
  6027 
  6028 * Isar/Pure: scalable support for case-analysis type proofs: new
  6029 'case' language element refers to local contexts symbolically, as
  6030 produced by certain proof methods; internally, case names are attached
  6031 to theorems as "tags";
  6032 
  6033 * Isar/Pure: theory command 'hide' removes declarations from
  6034 class/type/const name spaces;
  6035 
  6036 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6037 indicate potential overloading;
  6038 
  6039 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6040 
  6041 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6042 "{a,b,c}" instead of {a,b,c};
  6043 
  6044 * Isar/Pure now provides its own version of intro/elim/dest
  6045 attributes; useful for building new logics, but beware of confusion
  6046 with the version in Provers/classical;
  6047 
  6048 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6049 case name 'antecedent';
  6050 
  6051 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6052 to the current context is now done automatically);
  6053 
  6054 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6055 for definining proof methods in ML;
  6056 
  6057 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6058 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6059 most cases, one should have to change intro!! to intro? only);
  6060 replaced "delrule" by "rule del";
  6061 
  6062 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6063 'symmetric' attribute (the latter supercedes [RS sym]);
  6064 
  6065 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6066 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6067 well (including splits);
  6068 
  6069 * Isar/Provers: Simplifier and Classical methods now support all kind
  6070 of modifiers used in the past, including 'cong', 'iff', etc.
  6071 
  6072 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6073 of Simplifier and Classical reasoner);
  6074 
  6075 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6076 now support named cases; major packages (inductive, datatype, primrec,
  6077 recdef) support case names and properly name parameters;
  6078 
  6079 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6080 monotonicity conditions are extracted to be proven at end of
  6081 calculations;
  6082 
  6083 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6084 method anyway;
  6085 
  6086 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6087 split_if split_if_asm; datatype package provides theorems foo.splits =
  6088 foo.split foo.split_asm for each datatype;
  6089 
  6090 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6091 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6092 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6093 use "(cases (simplified))" method in proper proof texts);
  6094 
  6095 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6096 
  6097 * Isar: names of theorems etc. may be natural numbers as well;
  6098 
  6099 * Isar: 'pr' command: optional arguments for goals_limit and
  6100 ProofContext.prems_limit; no longer prints theory contexts, but only
  6101 proof states;
  6102 
  6103 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6104 additional print modes to be specified; e.g. "pr(latex)" will print
  6105 proof state according to the Isabelle LaTeX style;
  6106 
  6107 * Isar: improved support for emulating tactic scripts, including proof
  6108 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6109 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6110 (for HOL datatypes);
  6111 
  6112 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6113 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6114 'proof method scripts' have to be in depth-first order;
  6115 
  6116 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6117 
  6118 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6119 should instead use individual commands for printing items
  6120 (print_commands, print_methods etc.);
  6121 
  6122 * Isar: added 'nothing' --- the empty list of theorems;
  6123 
  6124 
  6125 *** HOL ***
  6126 
  6127 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6128 corresponding virtual machine and a specification of its bytecode
  6129 verifier and a lightweight bytecode verifier, including proofs of
  6130 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6131 Cornelia Pusch (see also the homepage of project Bali at
  6132 http://isabelle.in.tum.de/Bali/);
  6133 
  6134 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6135 Clemens Ballarin;
  6136 
  6137 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6138 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6139 Rasmussen;
  6140 
  6141 * HOL/Lattice: fundamental concepts of lattice theory and order
  6142 structures, including duals, properties of bounds versus algebraic
  6143 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6144 Theorem for complete lattices etc.; may also serve as a demonstration
  6145 for abstract algebraic reasoning using axiomatic type classes, and
  6146 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6147 
  6148 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6149 von Oheimb;
  6150 
  6151 * HOL/IMPP: extension of IMP with local variables and mutually
  6152 recursive procedures, by David von Oheimb;
  6153 
  6154 * HOL/Lambda: converted into new-style theory and document;
  6155 
  6156 * HOL/ex/Multiquote: example of multiple nested quotations and
  6157 anti-quotations -- basically a generalized version of de-Bruijn
  6158 representation; very useful in avoiding lifting of operations;
  6159 
  6160 * HOL/record: added general record equality rule to simpset; fixed
  6161 select-update simplification procedure to handle extended records as
  6162 well; admit "r" as field name;
  6163 
  6164 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6165 other numeric types and also as the identity of groups, rings, etc.;
  6166 
  6167 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6168 Types nat and int belong to this axclass;
  6169 
  6170 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6171    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6172    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6173   two terms #m*u and #n*u are replaced by #(m+n)*u
  6174     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6175   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6176     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6177 
  6178 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6179 powerful prover for predicate logic but knows nothing of clasets; see
  6180 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6181 
  6182 * HOL: new version of "case_tac" subsumes both boolean case split and
  6183 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6184 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6185 
  6186 * HOL: simplification no longer dives into case-expressions: only the
  6187 selector expression is simplified, but not the remaining arms; to
  6188 enable full simplification of case-expressions for datatype t, you may
  6189 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6190 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6191 
  6192 * HOL/recdef: the recursion equations generated by 'recdef' for
  6193 function 'f' are now called f.simps instead of f.rules; if all
  6194 termination conditions are proved automatically, these simplification
  6195 rules are added to the simpset, as in primrec; rules may be named
  6196 individually as well, resulting in a separate list of theorems for
  6197 each equation;
  6198 
  6199 * HOL/While is a new theory that provides a while-combinator. It
  6200 permits the definition of tail-recursive functions without the
  6201 provision of a termination measure. The latter is necessary once the
  6202 invariant proof rule for while is applied.
  6203 
  6204 * HOL: new (overloaded) notation for the set of elements below/above
  6205 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6206 
  6207 * HOL: theorems impI, allI, ballI bound as "strip";
  6208 
  6209 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6210 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6211 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6212 
  6213 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6214 
  6215 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6216 main HOL, but was unused);
  6217 
  6218 * HOL: fewer consts declared as global (e.g. have to refer to
  6219 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6220 
  6221 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6222 in case of overlap with user translations (e.g. judgements over
  6223 tuples); (note that the underlying logical represenation is still
  6224 bogus);
  6225 
  6226 
  6227 *** ZF ***
  6228 
  6229 * ZF: simplification automatically cancels common terms in arithmetic
  6230 expressions over nat and int;
  6231 
  6232 * ZF: new treatment of nat to minimize type-checking: all operators
  6233 coerce their operands to a natu