NEWS
author haftmann
Tue Sep 28 15:33:56 2010 +0200 (2010-09-28)
changeset 39771 553f9b9aed28
parent 39754 150f831ce4a3
child 39910 10097e0a9dbd
permissions -rw-r--r--
NEWS
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    10 a Unicode character is treated as a single symbol, not a sequence of
    11 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    12 contain symbols without further backslash escapes, Unicode can now be
    13 used here as well.  Recall that Symbol.explode in ML provides a
    14 consistent view on symbols, while raw explode (or String.explode)
    15 merely give a byte-oriented representation.
    16 
    17 * Theory loading: only the master source file is looked-up in the
    18 implicit load path, all other files are addressed relatively to its
    19 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    20 
    21 * Special treatment of ML file names has been discontinued.
    22 Historically, optional extensions .ML or .sml were added on demand --
    23 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    24 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    25 
    26 * Various options that affect pretty printing etc. are now properly
    27 handled within the context via configuration options, instead of
    28 unsynchronized references.  There are both ML Config.T entities and
    29 Isar declaration attributes to access these.
    30 
    31   ML (Config.T)                 Isar (attribute)
    32 
    33   eta_contract                  eta_contract
    34   show_brackets                 show_brackets
    35   show_sorts                    show_sorts
    36   show_types                    show_types
    37   show_question_marks           show_question_marks
    38   show_consts                   show_consts
    39 
    40   Syntax.ambiguity_level        syntax_ambiguity_level
    41 
    42   Goal_Display.goals_limit      goals_limit
    43   Goal_Display.show_main_goal   show_main_goal
    44 
    45   Thy_Output.display            thy_output_display
    46   Thy_Output.quotes             thy_output_quotes
    47   Thy_Output.indent             thy_output_indent
    48   Thy_Output.source             thy_output_source
    49   Thy_Output.break              thy_output_break
    50 
    51 Note that corresponding "..._default" references in ML may be only
    52 changed globally at the ROOT session setup, but *not* within a theory.
    53 
    54 
    55 *** Pure ***
    56 
    57 * Interpretation command 'interpret' accepts a list of equations like
    58 'interpretation' does.
    59 
    60 * Diagnostic command 'print_interps' prints interpretations in proofs
    61 in addition to interpretations in theories.
    62 
    63 * Discontinued obsolete 'global' and 'local' commands to manipulate
    64 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    65 Sign.root_path and Sign.local_path may be applied directly where this
    66 feature is still required for historical reasons.
    67 
    68 * Discontinued ancient 'constdefs' command.  INCOMPATIBILITY, use
    69 'definition' instead.
    70 
    71 * Document antiquotations @{class} and @{type} for printing classes
    72 and type constructors.
    73 
    74 
    75 *** HOL ***
    76 
    77 * Dropped old primrec package.  INCOMPATIBILITY.
    78 
    79 * Improved infrastructure for term evaluation using code generator
    80 techniques, in particular static evaluation conversions.
    81 
    82 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
    83  
    84 * Renamed lemmas:
    85   expand_fun_eq -> fun_eq_iff
    86   expand_set_eq -> set_eq_iff
    87   set_ext -> set_eqI
    88  INCOMPATIBILITY.
    89 
    90 * Renamed class eq and constant eq (for code generation) to class equal
    91 and constant equal, plus renaming of related facts and various tuning.
    92 INCOMPATIBILITY.
    93 
    94 * Scala (2.8 or higher) has been added to the target languages of
    95 the code generator.
    96 
    97 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
    98 
    99 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
   100 canonical names for instance definitions for functions; various improvements.
   101 INCOMPATIBILITY.
   102 
   103 * Records: logical foundation type for records do not carry a '_type' suffix
   104 any longer.  INCOMPATIBILITY.
   105 
   106 * Code generation for records: more idiomatic representation of record types.
   107 Warning: records are not covered by ancient SML code generation any longer.
   108 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
   109 helps to succeed then:
   110 
   111   record 'a foo = ...
   112   ...
   113   rep_datatype foo_ext ...
   114 
   115 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   116 INCOMPATIBILITY.
   117 
   118 * Quickcheck in locales considers interpretations of that locale for
   119 counter example search.
   120 
   121 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
   122 in Library/State_Monad has been changed to avoid ambiguities.
   123 INCOMPATIBILITY.
   124 
   125 * Code generator: export_code without explicit file declaration prints
   126 to standard output.  INCOMPATIBILITY.
   127 
   128 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   129 respectively.  INCOMPATIBILITY.
   130 
   131 * Constant "split" has been merged with constant "prod_case";  names
   132 of ML functions, facts etc. involving split have been retained so far,
   133 though.  INCOMPATIBILITY.
   134 
   135 * Dropped old infix syntax "mem" for List.member;  use "in set"
   136 instead.  INCOMPATIBILITY.
   137 
   138 * Refactoring of code-generation specific operations in List.thy
   139 
   140   constants
   141     null ~> List.null
   142 
   143   facts
   144     mem_iff ~> member_def
   145     null_empty ~> null_def
   146 
   147 INCOMPATIBILITY.  Note that these were not suppossed to be used
   148 regularly unless for striking reasons;  their main purpose was code
   149 generation.
   150 
   151 * Some previously unqualified names have been qualified:
   152 
   153   types
   154     bool ~> HOL.bool
   155     nat ~> Nat.nat
   156 
   157   constants
   158     Trueprop ~> HOL.Trueprop
   159     True ~> HOL.True
   160     False ~> HOL.False
   161     op & ~> HOL.conj
   162     op | ~> HOL.disj
   163     op --> ~> HOL.implies
   164     op = ~> HOL.eq
   165     Not ~> HOL.Not
   166     The ~> HOL.The
   167     All ~> HOL.All
   168     Ex ~> HOL.Ex
   169     Ex1 ~> HOL.Ex1
   170     Let ~> HOL.Let
   171     If ~> HOL.If
   172     Ball ~> Set.Ball
   173     Bex ~> Set.Bex
   174     Suc ~> Nat.Suc
   175     Pair ~> Product_Type.Pair
   176     fst ~> Product_Type.fst
   177     snd ~> Product_Type.snd
   178     curry ~> Product_Type.curry
   179     op : ~> Set.member
   180     Collect ~> Set.Collect
   181 
   182 INCOMPATIBILITY.
   183 
   184 * Removed simplifier congruence rule of "prod_case", as has for long
   185 been the case with "split".  INCOMPATIBILITY.
   186 
   187 * Datatype package: theorems generated for executable equality
   188 (class eq) carry proper names and are treated as default code
   189 equations.
   190 
   191 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   192 INCOMPATIBILITY.
   193 
   194 * List.thy: use various operations from the Haskell prelude when
   195 generating Haskell code.
   196 
   197 * Multiset.thy: renamed empty_idemp -> empty_neutral
   198 
   199 * code_simp.ML and method code_simp: simplification with rules determined
   200 by code generator.
   201 
   202 * code generator: do not print function definitions for case
   203 combinators any longer.
   204 
   205 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   206 theorems are now stated in terms of euclidean spaces instead of finite
   207 cartesian products.
   208 
   209   types
   210     real ^ 'n ~>  'a::real_vector
   211               ~>  'a::euclidean_space
   212               ~>  'a::ordered_euclidean_space
   213         (depends on your needs)
   214 
   215   constants
   216      _ $ _        ~> _ $$ _
   217      \<chi> x. _  ~> \<chi>\<chi> x. _
   218      CARD('n)     ~> DIM('a)
   219 
   220 Also note that the indices are now natural numbers and not from some finite
   221 type. Finite cartesian products of euclidean spaces, products of euclidean
   222 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   223 
   224 INCOMPATIBILITY.
   225 
   226 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   227 as value for measures. Introduces Lebesgue Measure based on the integral in
   228 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   229 spaces.
   230 
   231  INCOMPATIBILITY.
   232 
   233 * Inductive package: offers new command "inductive_simps" to automatically
   234 derive instantiated and simplified equations for inductive predicates,
   235 similar to inductive_cases.
   236 
   237 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". surj_on is a
   238 generalization of surj, and "surj f" is now a abbreviation of "surj_on f UNIV".
   239 The theorems bij_def and surj_def are unchanged.
   240 
   241 * Function package: .psimps rules are no longer implicitly declared [simp].
   242 INCOMPATIBILITY.
   243 
   244 *** FOL ***
   245 
   246 * All constant names are now qualified.  INCOMPATIBILITY.
   247 
   248 
   249 *** ZF ***
   250 
   251 * All constant names are now qualified.  INCOMPATIBILITY.
   252 
   253 
   254 *** ML ***
   255 
   256 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   257 meaning.
   258 
   259 * Renamed structure PureThy to Pure_Thy and moved most of its
   260 operations to structure Global_Theory, to emphasize that this is
   261 rarely-used global-only stuff.
   262 
   263 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   264 instead (or tracing for high-volume output).
   265 
   266 * Configuration option show_question_marks only affects regular pretty
   267 printing of types and terms, not raw Term.string_of_vname.
   268 
   269 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   270 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   271 @{thms} for most purposes.
   272 
   273 * ML structure Unsynchronized never opened, not even in Isar
   274 interaction mode as before.  Old Unsynchronized.set etc. have been
   275 discontinued -- use plain := instead.  This should be *rare* anyway,
   276 since modern tools always work via official context data, notably
   277 configuration options.
   278 
   279 * ML antiquotations @{theory} and @{theory_ref} refer to named
   280 theories from the ancestry of the current context, not any accidental
   281 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   282 change in semantics.
   283 
   284 * Parallel and asynchronous execution requires special care concerning
   285 interrupts.  Structure Exn provides some convenience functions that
   286 avoid working directly with raw Interrupt.  User code must not absorb
   287 interrupts -- intermediate handling (for cleanup etc.) needs to be
   288 followed by re-raising of the original exception.  Another common
   289 source of mistakes are "handle _" patterns, which make the meaning of
   290 the program subject to physical effects of the environment.
   291 
   292 
   293 *** System ***
   294 
   295 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   296 
   297 
   298 
   299 New in Isabelle2009-2 (June 2010)
   300 ---------------------------------
   301 
   302 *** General ***
   303 
   304 * Authentic syntax for *all* logical entities (type classes, type
   305 constructors, term constants): provides simple and robust
   306 correspondence between formal entities and concrete syntax.  Within
   307 the parse tree / AST representations, "constants" are decorated by
   308 their category (class, type, const) and spelled out explicitly with
   309 their full internal name.
   310 
   311 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   312 and translations (translation rules and translation functions in ML).
   313 Some hints on upgrading:
   314 
   315   - Many existing uses of 'syntax' and 'translations' can be replaced
   316     by more modern 'type_notation', 'notation' and 'abbreviation',
   317     which are independent of this issue.
   318 
   319   - 'translations' require markup within the AST; the term syntax
   320     provides the following special forms:
   321 
   322       CONST c   -- produces syntax version of constant c from context
   323       XCONST c  -- literally c, checked as constant from context
   324       c         -- literally c, if declared by 'syntax'
   325 
   326     Plain identifiers are treated as AST variables -- occasionally the
   327     system indicates accidental variables via the error "rhs contains
   328     extra variables".
   329 
   330     Type classes and type constructors are marked according to their
   331     concrete syntax.  Some old translations rules need to be written
   332     for the "type" category, using type constructor application
   333     instead of pseudo-term application of the default category
   334     "logic".
   335 
   336   - 'parse_translation' etc. in ML may use the following
   337     antiquotations:
   338 
   339       @{class_syntax c}   -- type class c within parse tree / AST
   340       @{term_syntax c}    -- type constructor c within parse tree / AST
   341       @{const_syntax c}   -- ML version of "CONST c" above
   342       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   343 
   344   - Literal types within 'typed_print_translations', i.e. those *not*
   345     represented as pseudo-terms are represented verbatim.  Use @{class
   346     c} or @{type_name c} here instead of the above syntax
   347     antiquotations.
   348 
   349 Note that old non-authentic syntax was based on unqualified base
   350 names, so all of the above "constant" names would coincide.  Recall
   351 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   352 diagnose syntax problems.
   353 
   354 * Type constructors admit general mixfix syntax, not just infix.
   355 
   356 * Concrete syntax may be attached to local entities without a proof
   357 body, too.  This works via regular mixfix annotations for 'fix',
   358 'def', 'obtain' etc. or via the explicit 'write' command, which is
   359 similar to the 'notation' command in theory specifications.
   360 
   361 * Discontinued unnamed infix syntax (legacy feature for many years) --
   362 need to specify constant name and syntax separately.  Internal ML
   363 datatype constructors have been renamed from InfixName to Infix etc.
   364 Minor INCOMPATIBILITY.
   365 
   366 * Schematic theorem statements need to be explicitly markup as such,
   367 via commands 'schematic_lemma', 'schematic_theorem',
   368 'schematic_corollary'.  Thus the relevance of the proof is made
   369 syntactically clear, which impacts performance in a parallel or
   370 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   371 
   372 * Use of cumulative prems via "!" in some proof methods has been
   373 discontinued (old legacy feature).
   374 
   375 * References 'trace_simp' and 'debug_simp' have been replaced by
   376 configuration options stored in the context. Enabling tracing (the
   377 case of debugging is similar) in proofs works via
   378 
   379   using [[trace_simp = true]]
   380 
   381 Tracing is then active for all invocations of the simplifier in
   382 subsequent goal refinement steps. Tracing may also still be enabled or
   383 disabled via the ProofGeneral settings menu.
   384 
   385 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   386 'hide_fact' replace the former 'hide' KIND command.  Minor
   387 INCOMPATIBILITY.
   388 
   389 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   390 more efficient than combinations with -q1 or -q2.
   391 
   392 
   393 *** Pure ***
   394 
   395 * Proofterms record type-class reasoning explicitly, using the
   396 "unconstrain" operation internally.  This eliminates all sort
   397 constraints from a theorem and proof, introducing explicit
   398 OFCLASS-premises.  On the proof term level, this operation is
   399 automatically applied at theorem boundaries, such that closed proofs
   400 are always free of sort constraints.  INCOMPATIBILITY for tools that
   401 inspect proof terms.
   402 
   403 * Local theory specifications may depend on extra type variables that
   404 are not present in the result type -- arguments TYPE('a) :: 'a itself
   405 are added internally.  For example:
   406 
   407   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   408 
   409 * Predicates of locales introduced by classes carry a mandatory
   410 "class" prefix.  INCOMPATIBILITY.
   411 
   412 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   413 
   414 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   415 'class' instead.
   416 
   417 * Command 'code_reflect' allows to incorporate generated ML code into
   418 runtime environment; replaces immature code_datatype antiquotation.
   419 INCOMPATIBILITY.
   420 
   421 * Code generator: simple concept for abstract datatypes obeying
   422 invariants.
   423 
   424 * Code generator: details of internal data cache have no impact on the
   425 user space functionality any longer.
   426 
   427 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   428 subgoals.  This is more appropriate for interpretations with 'where'.
   429 INCOMPATIBILITY.
   430 
   431 * Command 'example_proof' opens an empty proof body.  This allows to
   432 experiment with Isar, without producing any persistent result.
   433 
   434 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   435 within a local theory context, with explicit checking of the
   436 constructors involved (in contrast to the raw 'syntax' versions).
   437 
   438 * Commands 'types' and 'typedecl' now work within a local theory
   439 context -- without introducing dependencies on parameters or
   440 assumptions, which is not possible in Isabelle/Pure.
   441 
   442 * Command 'defaultsort' has been renamed to 'default_sort', it works
   443 within a local theory context.  Minor INCOMPATIBILITY.
   444 
   445 
   446 *** HOL ***
   447 
   448 * Command 'typedef' now works within a local theory context -- without
   449 introducing dependencies on parameters or assumptions, which is not
   450 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   451 contain multiple interpretations of local typedefs (with different
   452 non-emptiness proofs), even in a global theory context.
   453 
   454 * New package for quotient types.  Commands 'quotient_type' and
   455 'quotient_definition' may be used for defining types and constants by
   456 quotient constructions.  An example is the type of integers created by
   457 quotienting pairs of natural numbers:
   458 
   459   fun
   460     intrel :: "(nat * nat) => (nat * nat) => bool"
   461   where
   462     "intrel (x, y) (u, v) = (x + v = u + y)"
   463 
   464   quotient_type int = "nat * nat" / intrel
   465     by (auto simp add: equivp_def expand_fun_eq)
   466 
   467   quotient_definition
   468     "0::int" is "(0::nat, 0::nat)"
   469 
   470 The method "lifting" can be used to lift of theorems from the
   471 underlying "raw" type to the quotient type.  The example
   472 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   473 construction and provides a reasoning infrastructure for finite sets.
   474 
   475 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   476 clash with new theory Quotient in Main HOL.
   477 
   478 * Moved the SMT binding into the main HOL session, eliminating
   479 separate HOL-SMT session.
   480 
   481 * List membership infix mem operation is only an input abbreviation.
   482 INCOMPATIBILITY.
   483 
   484 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   485 for future developements; former Library/Word.thy is still present in
   486 the AFP entry RSAPPS.
   487 
   488 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   489 longer shadowed.  INCOMPATIBILITY.
   490 
   491 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   492 INCOMPATIBILITY.
   493 
   494 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   495 INCOMPATIBILITY.
   496 
   497 * Dropped normalizing_semiring etc; use the facts in semiring classes
   498 instead.  INCOMPATIBILITY.
   499 
   500 * Dropped several real-specific versions of lemmas about floor and
   501 ceiling; use the generic lemmas from theory "Archimedean_Field"
   502 instead.  INCOMPATIBILITY.
   503 
   504   floor_number_of_eq         ~> floor_number_of
   505   le_floor_eq_number_of      ~> number_of_le_floor
   506   le_floor_eq_zero           ~> zero_le_floor
   507   le_floor_eq_one            ~> one_le_floor
   508   floor_less_eq_number_of    ~> floor_less_number_of
   509   floor_less_eq_zero         ~> floor_less_zero
   510   floor_less_eq_one          ~> floor_less_one
   511   less_floor_eq_number_of    ~> number_of_less_floor
   512   less_floor_eq_zero         ~> zero_less_floor
   513   less_floor_eq_one          ~> one_less_floor
   514   floor_le_eq_number_of      ~> floor_le_number_of
   515   floor_le_eq_zero           ~> floor_le_zero
   516   floor_le_eq_one            ~> floor_le_one
   517   floor_subtract_number_of   ~> floor_diff_number_of
   518   floor_subtract_one         ~> floor_diff_one
   519   ceiling_number_of_eq       ~> ceiling_number_of
   520   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   521   ceiling_le_zero_eq         ~> ceiling_le_zero
   522   ceiling_le_eq_one          ~> ceiling_le_one
   523   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   524   less_ceiling_eq_zero       ~> zero_less_ceiling
   525   less_ceiling_eq_one        ~> one_less_ceiling
   526   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   527   ceiling_less_eq_zero       ~> ceiling_less_zero
   528   ceiling_less_eq_one        ~> ceiling_less_one
   529   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   530   le_ceiling_eq_zero         ~> zero_le_ceiling
   531   le_ceiling_eq_one          ~> one_le_ceiling
   532   ceiling_subtract_number_of ~> ceiling_diff_number_of
   533   ceiling_subtract_one       ~> ceiling_diff_one
   534 
   535 * Theory "Finite_Set": various folding_XXX locales facilitate the
   536 application of the various fold combinators on finite sets.
   537 
   538 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   539 provides abstract red-black tree type which is backed by "RBT_Impl" as
   540 implementation.  INCOMPATIBILTY.
   541 
   542 * Theory Library/Coinductive_List has been removed -- superseded by
   543 AFP/thys/Coinductive.
   544 
   545 * Theory PReal, including the type "preal" and related operations, has
   546 been removed.  INCOMPATIBILITY.
   547 
   548 * Real: new development using Cauchy Sequences.
   549 
   550 * Split off theory "Big_Operators" containing setsum, setprod,
   551 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   552 
   553 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   554 "Int" etc.  INCOMPATIBILITY.
   555 
   556 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   557 
   558 * New set of rules "ac_simps" provides combined assoc / commute
   559 rewrites for all interpretations of the appropriate generic locales.
   560 
   561 * Renamed theory "OrderedGroup" to "Groups" and split theory
   562 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   563 appropriate and more consistent names suitable for name prefixes
   564 within the HOL theories.  INCOMPATIBILITY.
   565 
   566 * Some generic constants have been put to appropriate theories:
   567   - less_eq, less: Orderings
   568   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   569   - inverse, divide: Rings
   570 INCOMPATIBILITY.
   571 
   572 * More consistent naming of type classes involving orderings (and
   573 lattices):
   574 
   575     lower_semilattice                   ~> semilattice_inf
   576     upper_semilattice                   ~> semilattice_sup
   577 
   578     dense_linear_order                  ~> dense_linorder
   579 
   580     pordered_ab_group_add               ~> ordered_ab_group_add
   581     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   582     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   583     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   584     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   585     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   586     pordered_cancel_semiring            ~> ordered_cancel_semiring
   587     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   588     pordered_comm_ring                  ~> ordered_comm_ring
   589     pordered_comm_semiring              ~> ordered_comm_semiring
   590     pordered_ring                       ~> ordered_ring
   591     pordered_ring_abs                   ~> ordered_ring_abs
   592     pordered_semiring                   ~> ordered_semiring
   593 
   594     ordered_ab_group_add                ~> linordered_ab_group_add
   595     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   596     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   597     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   598     ordered_field                       ~> linordered_field
   599     ordered_field_no_lb                 ~> linordered_field_no_lb
   600     ordered_field_no_ub                 ~> linordered_field_no_ub
   601     ordered_field_dense_linear_order    ~> dense_linordered_field
   602     ordered_idom                        ~> linordered_idom
   603     ordered_ring                        ~> linordered_ring
   604     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   605     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   606     ordered_ring_strict                 ~> linordered_ring_strict
   607     ordered_semidom                     ~> linordered_semidom
   608     ordered_semiring                    ~> linordered_semiring
   609     ordered_semiring_1                  ~> linordered_semiring_1
   610     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   611     ordered_semiring_strict             ~> linordered_semiring_strict
   612 
   613   The following slightly odd type classes have been moved to a
   614   separate theory Library/Lattice_Algebras:
   615 
   616     lordered_ab_group_add               ~> lattice_ab_group_add
   617     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   618     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   619     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   620     lordered_ring                       ~> lattice_ring
   621 
   622 INCOMPATIBILITY.
   623 
   624 * Refined field classes:
   625   - classes division_ring_inverse_zero, field_inverse_zero,
   626     linordered_field_inverse_zero include rule inverse 0 = 0 --
   627     subsumes former division_by_zero class;
   628   - numerous lemmas have been ported from field to division_ring.
   629 INCOMPATIBILITY.
   630 
   631 * Refined algebra theorem collections:
   632   - dropped theorem group group_simps, use algebra_simps instead;
   633   - dropped theorem group ring_simps, use field_simps instead;
   634   - proper theorem collection field_simps subsumes former theorem
   635     groups field_eq_simps and field_simps;
   636   - dropped lemma eq_minus_self_iff which is a duplicate for
   637     equal_neg_zero.
   638 INCOMPATIBILITY.
   639 
   640 * Theory Finite_Set and List: some lemmas have been generalized from
   641 sets to lattices:
   642 
   643   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   644   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   645   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   646   union_Union_fold_union        ~> sup_Sup_fold_sup
   647   Inter_fold_inter              ~> Inf_fold_inf
   648   Union_fold_union              ~> Sup_fold_sup
   649   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   650   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   651   INTER_fold_inter              ~> INFI_fold_inf
   652   UNION_fold_union              ~> SUPR_fold_sup
   653 
   654 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   655 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   656 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   657 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   658 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   659 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   660 
   661 * Reorganized theory Multiset: swapped notation of pointwise and
   662 multiset order:
   663 
   664   - pointwise ordering is instance of class order with standard syntax
   665     <= and <;
   666   - multiset ordering has syntax <=# and <#; partial order properties
   667     are provided by means of interpretation with prefix
   668     multiset_order;
   669   - less duplication, less historical organization of sections,
   670     conversion from associations lists to multisets, rudimentary code
   671     generation;
   672   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   673     if needed.
   674 
   675 Renamed:
   676 
   677   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   678   multi_count_ext  ~>  multiset_ext
   679   diff_union_inverse2  ~>  diff_union_cancelR
   680 
   681 INCOMPATIBILITY.
   682 
   683 * Theory Permutation: replaced local "remove" by List.remove1.
   684 
   685 * Code generation: ML and OCaml code is decorated with signatures.
   686 
   687 * Theory List: added transpose.
   688 
   689 * Library/Nat_Bijection.thy is a collection of bijective functions
   690 between nat and other types, which supersedes the older libraries
   691 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   692 
   693   Constants:
   694   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   695   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   696   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   697   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   698   Countable.pair_encode           ~> prod_encode
   699   NatIso.prod2nat                 ~> prod_encode
   700   NatIso.nat2prod                 ~> prod_decode
   701   NatIso.sum2nat                  ~> sum_encode
   702   NatIso.nat2sum                  ~> sum_decode
   703   NatIso.list2nat                 ~> list_encode
   704   NatIso.nat2list                 ~> list_decode
   705   NatIso.set2nat                  ~> set_encode
   706   NatIso.nat2set                  ~> set_decode
   707 
   708   Lemmas:
   709   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   710   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   711   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   712   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   713   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   714   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   715   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   716   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   717   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   718   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   719   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   720   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   721   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   722 
   723 * Sledgehammer:
   724   - Renamed ATP commands:
   725     atp_info     ~> sledgehammer running_atps
   726     atp_kill     ~> sledgehammer kill_atps
   727     atp_messages ~> sledgehammer messages
   728     atp_minimize ~> sledgehammer minimize
   729     print_atps   ~> sledgehammer available_atps
   730     INCOMPATIBILITY.
   731   - Added user's manual ("isabelle doc sledgehammer").
   732   - Added option syntax and "sledgehammer_params" to customize
   733     Sledgehammer's behavior.  See the manual for details.
   734   - Modified the Isar proof reconstruction code so that it produces
   735     direct proofs rather than proofs by contradiction.  (This feature
   736     is still experimental.)
   737   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   738     full-typed mode.
   739   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   740 
   741 * Nitpick:
   742   - Added and implemented "binary_ints" and "bits" options.
   743   - Added "std" option and implemented support for nonstandard models.
   744   - Added and implemented "finitize" option to improve the precision
   745     of infinite datatypes based on a monotonicity analysis.
   746   - Added support for quotient types.
   747   - Added support for "specification" and "ax_specification"
   748     constructs.
   749   - Added support for local definitions (for "function" and
   750     "termination" proofs).
   751   - Added support for term postprocessors.
   752   - Optimized "Multiset.multiset" and "FinFun.finfun".
   753   - Improved efficiency of "destroy_constrs" optimization.
   754   - Fixed soundness bugs related to "destroy_constrs" optimization and
   755     record getters.
   756   - Fixed soundness bug related to higher-order constructors.
   757   - Fixed soundness bug when "full_descrs" is enabled.
   758   - Improved precision of set constructs.
   759   - Added "atoms" option.
   760   - Added cache to speed up repeated Kodkod invocations on the same
   761     problems.
   762   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
   763     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
   764     "SAT4J_Light".  INCOMPATIBILITY.
   765   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
   766     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
   767   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
   768 
   769 * Method "induct" now takes instantiations of the form t, where t is not
   770   a variable, as a shorthand for "x == t", where x is a fresh variable.
   771   If this is not intended, t has to be enclosed in parentheses.
   772   By default, the equalities generated by definitional instantiations
   773   are pre-simplified, which may cause parameters of inductive cases
   774   to disappear, or may even delete some of the inductive cases.
   775   Use "induct (no_simp)" instead of "induct" to restore the old
   776   behaviour. The (no_simp) option is also understood by the "cases"
   777   and "nominal_induct" methods, which now perform pre-simplification, too.
   778   INCOMPATIBILITY.
   779 
   780 
   781 *** HOLCF ***
   782 
   783 * Variable names in lemmas generated by the domain package have
   784 changed; the naming scheme is now consistent with the HOL datatype
   785 package.  Some proof scripts may be affected, INCOMPATIBILITY.
   786 
   787 * The domain package no longer defines the function "foo_copy" for
   788 recursive domain "foo".  The reach lemma is now stated directly in
   789 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
   790 be reformulated in terms of "foo_take", INCOMPATIBILITY.
   791 
   792 * Most definedness lemmas generated by the domain package (previously
   793 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
   794 like "foo$x = UU <-> x = UU", which works better as a simp rule.
   795 Proofs that used definedness lemmas as intro rules may break,
   796 potential INCOMPATIBILITY.
   797 
   798 * Induction and casedist rules generated by the domain package now
   799 declare proper case_names (one called "bottom", and one named for each
   800 constructor).  INCOMPATIBILITY.
   801 
   802 * For mutually-recursive domains, separate "reach" and "take_lemma"
   803 rules are generated for each domain, INCOMPATIBILITY.
   804 
   805   foo_bar.reach       ~> foo.reach  bar.reach
   806   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
   807 
   808 * Some lemmas generated by the domain package have been renamed for
   809 consistency with the datatype package, INCOMPATIBILITY.
   810 
   811   foo.ind        ~> foo.induct
   812   foo.finite_ind ~> foo.finite_induct
   813   foo.coind      ~> foo.coinduct
   814   foo.casedist   ~> foo.exhaust
   815   foo.exhaust    ~> foo.nchotomy
   816 
   817 * For consistency with other definition packages, the fixrec package
   818 now generates qualified theorem names, INCOMPATIBILITY.
   819 
   820   foo_simps  ~> foo.simps
   821   foo_unfold ~> foo.unfold
   822   foo_induct ~> foo.induct
   823 
   824 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
   825 method and internal fixrec proofs now use the default simpset instead.
   826 INCOMPATIBILITY.
   827 
   828 * The "contlub" predicate has been removed.  Proof scripts should use
   829 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
   830 
   831 * The "admw" predicate has been removed, INCOMPATIBILITY.
   832 
   833 * The constants cpair, cfst, and csnd have been removed in favor of
   834 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
   835 
   836 
   837 *** ML ***
   838 
   839 * Antiquotations for basic formal entities:
   840 
   841     @{class NAME}         -- type class
   842     @{class_syntax NAME}  -- syntax representation of the above
   843 
   844     @{type_name NAME}     -- logical type
   845     @{type_abbrev NAME}   -- type abbreviation
   846     @{nonterminal NAME}   -- type of concrete syntactic category
   847     @{type_syntax NAME}   -- syntax representation of any of the above
   848 
   849     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   850     @{const_abbrev NAME}  -- abbreviated constant
   851     @{const_syntax NAME}  -- syntax representation of any of the above
   852 
   853 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   854 syntax constant (cf. 'syntax' command).
   855 
   856 * Antiquotation @{make_string} inlines a function to print arbitrary
   857 values similar to the ML toplevel.  The result is compiler dependent
   858 and may fall back on "?" in certain situations.
   859 
   860 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
   861 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
   862 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
   863 not work with the asynchronous Isar document model.
   864 
   865 * Configuration options now admit dynamic default values, depending on
   866 the context or even global references.
   867 
   868 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
   869 uses an efficient external library if available (for Poly/ML).
   870 
   871 * Renamed some important ML structures, while keeping the old names
   872 for some time as aliases within the structure Legacy:
   873 
   874   OuterKeyword  ~>  Keyword
   875   OuterLex      ~>  Token
   876   OuterParse    ~>  Parse
   877   OuterSyntax   ~>  Outer_Syntax
   878   PrintMode     ~>  Print_Mode
   879   SpecParse     ~>  Parse_Spec
   880   ThyInfo       ~>  Thy_Info
   881   ThyLoad       ~>  Thy_Load
   882   ThyOutput     ~>  Thy_Output
   883   TypeInfer     ~>  Type_Infer
   884 
   885 Note that "open Legacy" simplifies porting of sources, but forgetting
   886 to remove it again will complicate porting again in the future.
   887 
   888 * Most operations that refer to a global context are named
   889 accordingly, e.g. Simplifier.global_context or
   890 ProofContext.init_global.  There are some situations where a global
   891 context actually works, but under normal circumstances one needs to
   892 pass the proper local context through the code!
   893 
   894 * Discontinued old TheoryDataFun with its copy/init operation -- data
   895 needs to be pure.  Functor Theory_Data_PP retains the traditional
   896 Pretty.pp argument to merge, which is absent in the standard
   897 Theory_Data version.
   898 
   899 * Sorts.certify_sort and derived "cert" operations for types and terms
   900 no longer minimize sorts.  Thus certification at the boundary of the
   901 inference kernel becomes invariant under addition of class relations,
   902 which is an important monotonicity principle.  Sorts are now minimized
   903 in the syntax layer only, at the boundary between the end-user and the
   904 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
   905 explicitly in rare situations.
   906 
   907 * Renamed old-style Drule.standard to Drule.export_without_context, to
   908 emphasize that this is in no way a standard operation.
   909 INCOMPATIBILITY.
   910 
   911 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   912 usual for resolution.  Rare INCOMPATIBILITY.
   913 
   914 * Renamed varify/unvarify operations to varify_global/unvarify_global
   915 to emphasize that these only work in a global situation (which is
   916 quite rare).
   917 
   918 * Curried take and drop in library.ML; negative length is interpreted
   919 as infinity (as in chop).  Subtle INCOMPATIBILITY.
   920 
   921 * Proof terms: type substitutions on proof constants now use canonical
   922 order of type variables.  INCOMPATIBILITY for tools working with proof
   923 terms.
   924 
   925 * Raw axioms/defs may no longer carry sort constraints, and raw defs
   926 may no longer carry premises.  User-level specifications are
   927 transformed accordingly by Thm.add_axiom/add_def.
   928 
   929 
   930 *** System ***
   931 
   932 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   933 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   934 proof terms are enabled unconditionally in the new HOL-Proofs image.
   935 
   936 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   937 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   938 respectively.
   939 
   940 * Old lib/scripts/polyml-platform is superseded by the
   941 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
   942 variant, even on a 64 bit machine.  The following example setting
   943 prefers 64 bit if available:
   944 
   945   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
   946 
   947 * The preliminary Isabelle/jEdit application demonstrates the emerging
   948 Isabelle/Scala layer for advanced prover interaction and integration.
   949 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
   950 component.
   951 
   952 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
   953 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
   954 similar to the default assignment of the document preparation system
   955 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
   956 provides some operations for direct access to the font without asking
   957 the user for manual installation.
   958 
   959 
   960 
   961 New in Isabelle2009-1 (December 2009)
   962 -------------------------------------
   963 
   964 *** General ***
   965 
   966 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   967 one backslash should be used, even in ML sources.
   968 
   969 
   970 *** Pure ***
   971 
   972 * Locale interpretation propagates mixins along the locale hierarchy.
   973 The currently only available mixins are the equations used to map
   974 local definitions to terms of the target domain of an interpretation.
   975 
   976 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   977 loc" to print all interpretations of locale "loc" in the theory.
   978 Interpretations in proofs are not shown.
   979 
   980 * Thoroughly revised locales tutorial.  New section on conditional
   981 interpretation.
   982 
   983 * On instantiation of classes, remaining undefined class parameters
   984 are formally declared.  INCOMPATIBILITY.
   985 
   986 
   987 *** Document preparation ***
   988 
   989 * New generalized style concept for printing terms: @{foo (style) ...}
   990 instead of @{foo_style style ...}  (old form is still retained for
   991 backward compatibility).  Styles can be also applied for
   992 antiquotations prop, term_type and typeof.
   993 
   994 
   995 *** HOL ***
   996 
   997 * New proof method "smt" for a combination of first-order logic with
   998 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   999 fixed-size bitvectors; there is also basic support for higher-order
  1000 features (esp. lambda abstractions).  It is an incomplete decision
  1001 procedure based on external SMT solvers using the oracle mechanism;
  1002 for the SMT solver Z3, this method is proof-producing.  Certificates
  1003 are provided to avoid calling the external solvers solely for
  1004 re-checking proofs.  Due to a remote SMT service there is no need for
  1005 installing SMT solvers locally.  See src/HOL/SMT.
  1006 
  1007 * New commands to load and prove verification conditions generated by
  1008 the Boogie program verifier or derived systems (e.g. the Verifying C
  1009 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1010 
  1011 * New counterexample generator tool 'nitpick' based on the Kodkod
  1012 relational model finder.  See src/HOL/Tools/Nitpick and
  1013 src/HOL/Nitpick_Examples.
  1014 
  1015 * New commands 'code_pred' and 'values' to invoke the predicate
  1016 compiler and to enumerate values of inductive predicates.
  1017 
  1018 * A tabled implementation of the reflexive transitive closure.
  1019 
  1020 * New implementation of quickcheck uses generic code generator;
  1021 default generators are provided for all suitable HOL types, records
  1022 and datatypes.  Old quickcheck can be re-activated importing theory
  1023 Library/SML_Quickcheck.
  1024 
  1025 * New testing tool Mirabelle for automated proof tools.  Applies
  1026 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1027 every proof step in a theory.  To be used in batch mode via the
  1028 "mirabelle" utility.
  1029 
  1030 * New proof method "sos" (sum of squares) for nonlinear real
  1031 arithmetic (originally due to John Harison). It requires theory
  1032 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1033 works well in practice on quantifier-free real arithmetic with +, -,
  1034 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1035 inequalities between polynomials.  It makes use of external
  1036 semidefinite programming solvers.  Method "sos" generates a
  1037 certificate that can be pasted into the proof thus avoiding the need
  1038 to call an external tool every time the proof is checked.  See
  1039 src/HOL/Library/Sum_Of_Squares.
  1040 
  1041 * New method "linarith" invokes existing linear arithmetic decision
  1042 procedure only.
  1043 
  1044 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1045 
  1046 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1047 Causes full type information to be output to the ATPs.  This slows
  1048 ATPs down considerably but eliminates a source of unsound "proofs"
  1049 that fail later.
  1050 
  1051 * New method "metisFT": A version of metis that uses full type
  1052 information in order to avoid failures of proof reconstruction.
  1053 
  1054 * New evaluator "approximate" approximates an real valued term using
  1055 the same method as the approximation method.
  1056 
  1057 * Method "approximate" now supports arithmetic expressions as
  1058 boundaries of intervals and implements interval splitting and Taylor
  1059 series expansion.
  1060 
  1061 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1062 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1063 
  1064 * New theory SupInf of the supremum and infimum operators for sets of
  1065 reals.
  1066 
  1067 * New theory Probability, which contains a development of measure
  1068 theory, eventually leading to Lebesgue integration and probability.
  1069 
  1070 * Extended Multivariate Analysis to include derivation and Brouwer's
  1071 fixpoint theorem.
  1072 
  1073 * Reorganization of number theory, INCOMPATIBILITY:
  1074   - new number theory development for nat and int, in theories Divides
  1075     and GCD as well as in new session Number_Theory
  1076   - some constants and facts now suffixed with _nat and _int
  1077     accordingly
  1078   - former session NumberTheory now named Old_Number_Theory, including
  1079     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1080   - moved theory Pocklington from src/HOL/Library to
  1081     src/HOL/Old_Number_Theory
  1082 
  1083 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1084 lcm of finite and infinite sets. It is shown that they form a complete
  1085 lattice.
  1086 
  1087 * Class semiring_div requires superclass no_zero_divisors and proof of
  1088 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1089 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1090 generalized to class semiring_div, subsuming former theorems
  1091 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1092 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1093 INCOMPATIBILITY.
  1094 
  1095 * Refinements to lattice classes and sets:
  1096   - less default intro/elim rules in locale variant, more default
  1097     intro/elim rules in class variant: more uniformity
  1098   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1099     le_inf_iff
  1100   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1101     sup_aci)
  1102   - renamed ACI to inf_sup_aci
  1103   - new class "boolean_algebra"
  1104   - class "complete_lattice" moved to separate theory
  1105     "Complete_Lattice"; corresponding constants (and abbreviations)
  1106     renamed and with authentic syntax:
  1107     Set.Inf ~>    Complete_Lattice.Inf
  1108     Set.Sup ~>    Complete_Lattice.Sup
  1109     Set.INFI ~>   Complete_Lattice.INFI
  1110     Set.SUPR ~>   Complete_Lattice.SUPR
  1111     Set.Inter ~>  Complete_Lattice.Inter
  1112     Set.Union ~>  Complete_Lattice.Union
  1113     Set.INTER ~>  Complete_Lattice.INTER
  1114     Set.UNION ~>  Complete_Lattice.UNION
  1115   - authentic syntax for
  1116     Set.Pow
  1117     Set.image
  1118   - mere abbreviations:
  1119     Set.empty               (for bot)
  1120     Set.UNIV                (for top)
  1121     Set.inter               (for inf, formerly Set.Int)
  1122     Set.union               (for sup, formerly Set.Un)
  1123     Complete_Lattice.Inter  (for Inf)
  1124     Complete_Lattice.Union  (for Sup)
  1125     Complete_Lattice.INTER  (for INFI)
  1126     Complete_Lattice.UNION  (for SUPR)
  1127   - object-logic definitions as far as appropriate
  1128 
  1129 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1130 Un_subset_iff are explicitly deleted as default simp rules; then also
  1131 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1132 deleted to achieve the desired effect.
  1133 
  1134 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1135 rules by default any longer; the same applies to min_max.inf_absorb1
  1136 etc.  INCOMPATIBILITY.
  1137 
  1138 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1139 pred_set_conv by default.  INCOMPATIBILITY.
  1140 
  1141 * Power operations on relations and functions are now one dedicated
  1142 constant "compow" with infix syntax "^^".  Power operation on
  1143 multiplicative monoids retains syntax "^" and is now defined generic
  1144 in class power.  INCOMPATIBILITY.
  1145 
  1146 * Relation composition "R O S" now has a more standard argument order:
  1147 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1148 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1149 break, since the O_assoc rule was not rewritten like this.  Fix using
  1150 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1151 
  1152 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1153 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1154 INCOMPATIBILITY.
  1155 
  1156 * Most rules produced by inductive and datatype package have mandatory
  1157 prefixes.  INCOMPATIBILITY.
  1158 
  1159 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1160 the attribute of the same name.  Each of the theorems in the list
  1161 DERIV_intros assumes composition with an additional function and
  1162 matches a variable to the derivative, which has to be solved by the
  1163 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1164 of most elementary terms.  Former Maclauren.DERIV_tac and
  1165 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1166 INCOMPATIBILITY.
  1167 
  1168 * Code generator attributes follow the usual underscore convention:
  1169     code_unfold     replaces    code unfold
  1170     code_post       replaces    code post
  1171     etc.
  1172   INCOMPATIBILITY.
  1173 
  1174 * Renamed methods:
  1175     sizechange -> size_change
  1176     induct_scheme -> induction_schema
  1177   INCOMPATIBILITY.
  1178 
  1179 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1180 INCOMPATIBILITY, use "undefined" directly.
  1181 
  1182 * Renamed theorems:
  1183     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1184     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1185     Suc_plus1 -> Suc_eq_plus1
  1186     *anti_sym -> *antisym*
  1187     vector_less_eq_def -> vector_le_def
  1188   INCOMPATIBILITY.
  1189 
  1190 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1191 INCOMPATIBILITY.
  1192 
  1193 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1194 INCOMPATIBILITY.
  1195 
  1196 
  1197 *** HOLCF ***
  1198 
  1199 * Theory Representable defines a class "rep" of domains that are
  1200 representable (via an ep-pair) in the universal domain type "udom".
  1201 Instances are provided for all type constructors defined in HOLCF.
  1202 
  1203 * The 'new_domain' command is a purely definitional version of the
  1204 domain package, for representable domains.  Syntax is identical to the
  1205 old domain package.  The 'new_domain' package also supports indirect
  1206 recursion using previously-defined type constructors.  See
  1207 src/HOLCF/ex/New_Domain.thy for examples.
  1208 
  1209 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1210 on the left-hand side of an equation, and then performs
  1211 simplification.  Rewriting is done using rules declared with the
  1212 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1213 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1214 
  1215 * The pattern-match compiler in 'fixrec' can now handle constructors
  1216 with HOL function types.  Pattern-match combinators for the Pair
  1217 constructor are pre-configured.
  1218 
  1219 * The 'fixrec' package now produces better fixed-point induction rules
  1220 for mutually-recursive definitions:  Induction rules have conclusions
  1221 of the form "P foo bar" instead of "P <foo, bar>".
  1222 
  1223 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1224 been renamed to "below".  The name "below" now replaces "less" in many
  1225 theorem names.  (Legacy theorem names using "less" are still supported
  1226 as well.)
  1227 
  1228 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1229 patterns can be used to generate strictness rules, or to make
  1230 functions more strict (much like the bang-patterns supported by the
  1231 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1232 examples.
  1233 
  1234 
  1235 *** ML ***
  1236 
  1237 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1238 errors and run-time exceptions, including detailed source positions.
  1239 
  1240 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1241 identified entries, with some additional information such as source
  1242 position, logical grouping etc.
  1243 
  1244 * Theory and context data is now introduced by the simplified and
  1245 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1246 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1247 copy operation) is still available for some time.
  1248 
  1249 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1250 provides a high-level programming interface to synchronized state
  1251 variables with atomic update.  This works via pure function
  1252 application within a critical section -- its runtime should be as
  1253 short as possible; beware of deadlocks if critical code is nested,
  1254 either directly or indirectly via other synchronized variables!
  1255 
  1256 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1257 wraps raw ML references, explicitly indicating their non-thread-safe
  1258 behaviour.  The Isar toplevel keeps this structure open, to
  1259 accommodate Proof General as well as quick and dirty interactive
  1260 experiments with references.
  1261 
  1262 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1263 parallel tactical reasoning.
  1264 
  1265 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1266 are similar to SUBPROOF, but are slightly more flexible: only the
  1267 specified parts of the subgoal are imported into the context, and the
  1268 body tactic may introduce new subgoals and schematic variables.
  1269 
  1270 * Old tactical METAHYPS, which does not observe the proof context, has
  1271 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1272 or Subgoal.FOCUS etc.
  1273 
  1274 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1275 functors have their own ML name space there is no point to mark them
  1276 separately.)  Minor INCOMPATIBILITY.
  1277 
  1278 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1279 
  1280 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1281 INCOMPATIBILITY.
  1282 
  1283 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1284 mode, which avoids critical setmp.
  1285 
  1286 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1287 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1288 Attrib/Method.setup introduced in Isabelle2009.
  1289 
  1290 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1291 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1292 last resort.  INCOMPATIBILITY.
  1293 
  1294 * Display.pretty_thm now requires a proper context (cf. former
  1295 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1296 or even Display.pretty_thm_without_context as last resort.
  1297 INCOMPATIBILITY.
  1298 
  1299 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1300 Syntax.pretty_typ/term directly, preferably with proper context
  1301 instead of global theory.
  1302 
  1303 
  1304 *** System ***
  1305 
  1306 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1307 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1308 usedir option -q.
  1309 
  1310 * Support for additional "Isabelle components" via etc/components, see
  1311 also the system manual.
  1312 
  1313 * The isabelle makeall tool now operates on all components with
  1314 IsaMakefile, not just hardwired "logics".
  1315 
  1316 * Removed "compress" option from isabelle-process and isabelle usedir;
  1317 this is always enabled.
  1318 
  1319 * Discontinued support for Poly/ML 4.x versions.
  1320 
  1321 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1322 on a given logic image.  This requires the lighttpd webserver and is
  1323 currently supported on Linux only.
  1324 
  1325 
  1326 
  1327 New in Isabelle2009 (April 2009)
  1328 --------------------------------
  1329 
  1330 *** General ***
  1331 
  1332 * Simplified main Isabelle executables, with less surprises on
  1333 case-insensitive file-systems (such as Mac OS).
  1334 
  1335   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1336     "isatool."
  1337 
  1338   - The former "isabelle" alias for "isabelle-process" has been
  1339     removed (should rarely occur to regular users).
  1340 
  1341   - The former "isabelle-interface" and its alias "Isabelle" have been
  1342     removed (interfaces are now regular Isabelle tools).
  1343 
  1344 Within scripts and make files, the Isabelle environment variables
  1345 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1346 respectively.  (The latter are still available as legacy feature.)
  1347 
  1348 The old isabelle-interface wrapper could react in confusing ways if
  1349 the interface was uninstalled or changed otherwise.  Individual
  1350 interface tool configuration is now more explicit, see also the
  1351 Isabelle system manual.  In particular, Proof General is now available
  1352 via "isabelle emacs".
  1353 
  1354 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1355 purge installed copies of Isabelle executables and re-run "isabelle
  1356 install -p ...", or use symlinks.
  1357 
  1358 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1359 old ~/isabelle, which was slightly non-standard and apt to cause
  1360 surprises on case-insensitive file-systems (such as Mac OS).
  1361 
  1362 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1363 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1364 care is required when using older releases of Isabelle.  Note that
  1365 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1366 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1367 
  1368 * Proofs of fully specified statements are run in parallel on
  1369 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1370 a regular 4-core machine, if the initial heap space is made reasonably
  1371 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1372 
  1373 * The main reference manuals ("isar-ref", "implementation", and
  1374 "system") have been updated and extended.  Formally checked references
  1375 as hyperlinks are now available uniformly.
  1376 
  1377 
  1378 *** Pure ***
  1379 
  1380 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1381 respects.  The most important changes are listed below.  See the
  1382 Tutorial on Locales ("locales" manual) for details.
  1383 
  1384 - In locale expressions, instantiation replaces renaming.  Parameters
  1385 must be declared in a for clause.  To aid compatibility with previous
  1386 parameter inheritance, in locale declarations, parameters that are not
  1387 'touched' (instantiation position "_" or omitted) are implicitly added
  1388 with their syntax at the beginning of the for clause.
  1389 
  1390 - Syntax from abbreviations and definitions in locales is available in
  1391 locale expressions and context elements.  The latter is particularly
  1392 useful in locale declarations.
  1393 
  1394 - More flexible mechanisms to qualify names generated by locale
  1395 expressions.  Qualifiers (prefixes) may be specified in locale
  1396 expressions, and can be marked as mandatory (syntax: "name!:") or
  1397 optional (syntax "name?:").  The default depends for plain "name:"
  1398 depends on the situation where a locale expression is used: in
  1399 commands 'locale' and 'sublocale' prefixes are optional, in
  1400 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1401 implicit qualifiers derived from the parameter names of a locale are
  1402 no longer generated.
  1403 
  1404 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1405 instantiation clause in "interpretation" and "interpret" (square
  1406 brackets) is no longer available.  Use locale expressions.
  1407 
  1408 - When converting proof scripts, mandatory qualifiers in
  1409 'interpretation' and 'interpret' should be retained by default, even
  1410 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1411 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1412 in locale expressions range over a single locale instance only.
  1413 
  1414 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1415 In existing theorem specifications replace the includes element by the
  1416 respective context elements of the included locale, omitting those
  1417 that are already present in the theorem specification.  Multiple
  1418 assume elements of a locale should be replaced by a single one
  1419 involving the locale predicate.  In the proof body, declarations (most
  1420 notably theorems) may be regained by interpreting the respective
  1421 locales in the proof context as required (command "interpret").
  1422 
  1423 If using "includes" in replacement of a target solely because the
  1424 parameter types in the theorem are not as general as in the target,
  1425 consider declaring a new locale with additional type constraints on
  1426 the parameters (context element "constrains").
  1427 
  1428 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1429 
  1430 - Locale interpretation commands no longer attempt to simplify goal.
  1431 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1432 methods intro_locales and unfold_locales to clarify.
  1433 
  1434 - Locale interpretation commands no longer accept interpretation
  1435 attributes.  INCOMPATIBILITY.
  1436 
  1437 * Class declaration: so-called "base sort" must not be given in import
  1438 list any longer, but is inferred from the specification.  Particularly
  1439 in HOL, write
  1440 
  1441     class foo = ...
  1442 
  1443 instead of
  1444 
  1445     class foo = type + ...
  1446 
  1447 * Class target: global versions of theorems stemming do not carry a
  1448 parameter prefix any longer.  INCOMPATIBILITY.
  1449 
  1450 * Class 'instance' command no longer accepts attached definitions.
  1451 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1452 
  1453 * Recovered hiding of consts, which was accidentally broken in
  1454 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1455 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1456 
  1457 * Slightly more coherent Pure syntax, with updated documentation in
  1458 isar-ref manual.  Removed locales meta_term_syntax and
  1459 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1460 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1461 directly in regular applications.
  1462 
  1463 * There is a new syntactic category "float_const" for signed decimal
  1464 fractions (e.g. 123.45 or -123.45).
  1465 
  1466 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1467 interface with 'setup' command instead.
  1468 
  1469 * Command 'local_setup' is similar to 'setup', but operates on a local
  1470 theory context.
  1471 
  1472 * The 'axiomatization' command now only works within a global theory
  1473 context.  INCOMPATIBILITY.
  1474 
  1475 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1476 hypotheses.  Sorts required in the course of reasoning need to be
  1477 covered by the constraints in the initial statement, completed by the
  1478 type instance information of the background theory.  Non-trivial sort
  1479 hypotheses, which rarely occur in practice, may be specified via
  1480 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1481 
  1482   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1483 
  1484 The result contains an implicit sort hypotheses as before --
  1485 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1486 normalization.
  1487 
  1488 * Generalized Isar history, with support for linear undo, direct state
  1489 addressing etc.
  1490 
  1491 * Changed defaults for unify configuration options:
  1492 
  1493   unify_trace_bound = 50 (formerly 25)
  1494   unify_search_bound = 60 (formerly 30)
  1495 
  1496 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1497 
  1498   a) On theory merge, the last set of code equations for a particular
  1499      constant is taken (in accordance with the policy applied by other
  1500      parts of the code generator framework).
  1501 
  1502   b) Code equations stemming from explicit declarations (e.g. code
  1503      attribute) gain priority over default code equations stemming
  1504      from definition, primrec, fun etc.
  1505 
  1506 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1507 
  1508 * Unified theorem tables for both code generators.  Thus [code
  1509 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1510 
  1511 * Command 'find_consts' searches for constants based on type and name
  1512 patterns, e.g.
  1513 
  1514     find_consts "_ => bool"
  1515 
  1516 By default, matching is against subtypes, but it may be restricted to
  1517 the whole type.  Searching by name is possible.  Multiple queries are
  1518 conjunctive and queries may be negated by prefixing them with a
  1519 hyphen:
  1520 
  1521     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1522 
  1523 * New 'find_theorems' criterion "solves" matches theorems that
  1524 directly solve the current goal (modulo higher-order unification).
  1525 
  1526 * Auto solve feature for main theorem statements: whenever a new goal
  1527 is stated, "find_theorems solves" is called; any theorems that could
  1528 solve the lemma directly are listed as part of the goal state.
  1529 Cf. associated options in Proof General Isabelle settings menu,
  1530 enabled by default, with reasonable timeout for pathological cases of
  1531 higher-order unification.
  1532 
  1533 
  1534 *** Document preparation ***
  1535 
  1536 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1537 demanding keyword 'by' and supporting the full method expression
  1538 syntax just like the Isar command 'by'.
  1539 
  1540 
  1541 *** HOL ***
  1542 
  1543 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1544 points Main and Complex_Main remain as before.
  1545 
  1546 * Logic image HOL-Plain provides a minimal HOL with the most important
  1547 tools available (inductive, datatype, primrec, ...).  This facilitates
  1548 experimentation and tool development.  Note that user applications
  1549 (and library theories) should never refer to anything below theory
  1550 Main, as before.
  1551 
  1552 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1553 experimentation due to shorter build times.
  1554 
  1555 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1556 were previously part of former HOL-Complex.  Entry point Hyperreal
  1557 remains valid, but theories formerly using Complex_Main should now use
  1558 new entry point Hypercomplex.
  1559 
  1560 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1561 Posix processes.  Avoids potentially expensive forking of the ML
  1562 process.  New thread-based implementation also works on non-Unix
  1563 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1564 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1565 commands are covered in the isar-ref manual.
  1566 
  1567 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1568 sledgehammer without local ATP installation (Vampire etc.). Other
  1569 provers may be included via suitable ML wrappers, see also
  1570 src/HOL/ATP_Linkup.thy.
  1571 
  1572 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1573 menu.
  1574 
  1575 * The metis method no longer fails because the theorem is too trivial
  1576 (contains the empty clause).
  1577 
  1578 * The metis method now fails in the usual manner, rather than raising
  1579 an exception, if it determines that it cannot prove the theorem.
  1580 
  1581 * Method "coherent" implements a prover for coherent logic (see also
  1582 src/Tools/coherent.ML).
  1583 
  1584 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1585 "undefined" is the right choice to replace "arbitrary", though
  1586 logically there is no difference.  INCOMPATIBILITY.
  1587 
  1588 * Command "value" now integrates different evaluation mechanisms.  The
  1589 result of the first successful evaluation mechanism is printed.  In
  1590 square brackets a particular named evaluation mechanisms may be
  1591 specified (currently, [SML], [code] or [nbe]).  See further
  1592 src/HOL/ex/Eval_Examples.thy.
  1593 
  1594 * Normalization by evaluation now allows non-leftlinear equations.
  1595 Declare with attribute [code nbe].
  1596 
  1597 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1598 as the structured Isar versions "cases" and "induct", cf. the
  1599 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1600 are now presented as a list of individual projections
  1601 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1602 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1603 rare situations a different rule is selected --- notably nested tuple
  1604 elimination instead of former prod.exhaust: use explicit (case_tac t
  1605 rule: prod.exhaust) here.
  1606 
  1607 * Attributes "cases", "induct", "coinduct" support "del" option.
  1608 
  1609 * Removed fact "case_split_thm", which duplicates "case_split".
  1610 
  1611 * The option datatype has been moved to a new theory Option.  Renamed
  1612 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1613 
  1614 * New predicate "strict_mono" classifies strict functions on partial
  1615 orders.  With strict functions on linear orders, reasoning about
  1616 (in)equalities is facilitated by theorems "strict_mono_eq",
  1617 "strict_mono_less_eq" and "strict_mono_less".
  1618 
  1619 * Some set operations are now proper qualified constants with
  1620 authentic syntax.  INCOMPATIBILITY:
  1621 
  1622     op Int ~>   Set.Int
  1623     op Un ~>    Set.Un
  1624     INTER ~>    Set.INTER
  1625     UNION ~>    Set.UNION
  1626     Inter ~>    Set.Inter
  1627     Union ~>    Set.Union
  1628     {} ~>       Set.empty
  1629     UNIV ~>     Set.UNIV
  1630 
  1631 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1632 theory Set.
  1633 
  1634 * Auxiliary class "itself" has disappeared -- classes without any
  1635 parameter are treated as expected by the 'class' command.
  1636 
  1637 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1638 
  1639 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1640 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1641 
  1642 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1643 method "approximation".  It proves formulas on real values by using
  1644 interval arithmetic.  In the formulas are also the transcendental
  1645 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1646 allowed. For examples see
  1647 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1648 
  1649 * Theory "Reflection" now resides in HOL/Library.
  1650 
  1651 * Entry point to Word library now simply named "Word".
  1652 INCOMPATIBILITY.
  1653 
  1654 * Made source layout more coherent with logical distribution
  1655 structure:
  1656 
  1657     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1658     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1659     src/HOL/Library/GCD.thy ~> src/HOL/
  1660     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1661     src/HOL/Library/Parity.thy ~> src/HOL/
  1662     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1663     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1664     src/HOL/Real/Lubs.thy ~> src/HOL/
  1665     src/HOL/Real/PReal.thy ~> src/HOL/
  1666     src/HOL/Real/Rational.thy ~> src/HOL/
  1667     src/HOL/Real/RComplete.thy ~> src/HOL/
  1668     src/HOL/Real/RealDef.thy ~> src/HOL/
  1669     src/HOL/Real/RealPow.thy ~> src/HOL/
  1670     src/HOL/Real/Real.thy ~> src/HOL/
  1671     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1672     src/HOL/Complex/Complex.thy ~> src/HOL/
  1673     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1674     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1675     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1676     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1677     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1678     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1679     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1680     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1681     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1682     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1683     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1684     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1685     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1686     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1687     src/HOL/Real/Float ~> src/HOL/Library/
  1688     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1689     src/HOL/Real/RealVector.thy ~> src/HOL/
  1690 
  1691     src/HOL/arith_data.ML ~> src/HOL/Tools
  1692     src/HOL/hologic.ML ~> src/HOL/Tools
  1693     src/HOL/simpdata.ML ~> src/HOL/Tools
  1694     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1695     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1696     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1697     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1698     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1699     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1700     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1701 
  1702     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1703     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1704     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1705     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1706     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1707     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1708 
  1709 * If methods "eval" and "evaluation" encounter a structured proof
  1710 state with !!/==>, only the conclusion is evaluated to True (if
  1711 possible), avoiding strange error messages.
  1712 
  1713 * Method "sizechange" automates termination proofs using (a
  1714 modification of) the size-change principle.  Requires SAT solver.  See
  1715 src/HOL/ex/Termination.thy for examples.
  1716 
  1717 * Simplifier: simproc for let expressions now unfolds if bound
  1718 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1719 
  1720 * Method "arith": Linear arithmetic now ignores all inequalities when
  1721 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1722 
  1723 * New attribute "arith" for facts that should always be used
  1724 automatically by arithmetic. It is intended to be used locally in
  1725 proofs, e.g.
  1726 
  1727   assumes [arith]: "x > 0"
  1728 
  1729 Global usage is discouraged because of possible performance impact.
  1730 
  1731 * New classes "top" and "bot" with corresponding operations "top" and
  1732 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1733 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1734 
  1735 * Changed definition lemma "less_fun_def" in order to provide an
  1736 instance for preorders on functions; use lemma "less_le" instead.
  1737 INCOMPATIBILITY.
  1738 
  1739 * Theory Orderings: class "wellorder" moved here, with explicit
  1740 induction rule "less_induct" as assumption.  For instantiation of
  1741 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1742 INCOMPATIBILITY.
  1743 
  1744 * Theory Orderings: added class "preorder" as superclass of "order".
  1745 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1746 etc. slightly changed.  Some theorems named order_class.* now named
  1747 preorder_class.*.
  1748 
  1749 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1750 "diag" to "Id_on".
  1751 
  1752 * Theory Finite_Set: added a new fold combinator of type
  1753 
  1754   ('a => 'b => 'b) => 'b => 'a set => 'b
  1755 
  1756 Occasionally this is more convenient than the old fold combinator
  1757 which is now defined in terms of the new one and renamed to
  1758 fold_image.
  1759 
  1760 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1761 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1762 extended with further lemmas!).  At the moment both still exist but
  1763 the former will disappear at some point.
  1764 
  1765 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1766 class recpower.  Type-specific simp rules for various recpower types
  1767 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1768 
  1769 rat_power_0    -> power_0
  1770 rat_power_Suc  -> power_Suc
  1771 realpow_0      -> power_0
  1772 realpow_Suc    -> power_Suc
  1773 complexpow_0   -> power_0
  1774 complexpow_Suc -> power_Suc
  1775 power_poly_0   -> power_0
  1776 power_poly_Suc -> power_Suc
  1777 
  1778 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1779 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1780 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1781 of lemmas from Divides has been generalized from nat to class
  1782 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1783 renames resulting from duplicate elimination:
  1784 
  1785     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1786     zero_dvd_iff ~>         dvd_0_left_iff
  1787     dvd_0 ~>                dvd_0_right
  1788     DIVISION_BY_ZERO_DIV ~> div_by_0
  1789     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1790     mult_div ~>             div_mult_self2_is_id
  1791     mult_mod ~>             mod_mult_self2_is_0
  1792 
  1793 * Theory IntDiv: removed many lemmas that are instances of class-based
  1794 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1795 rename old lemmas as follows:
  1796 
  1797 dvd_diff               -> nat_dvd_diff
  1798 dvd_zminus_iff         -> dvd_minus_iff
  1799 mod_add1_eq            -> mod_add_eq
  1800 mod_mult1_eq           -> mod_mult_right_eq
  1801 mod_mult1_eq'          -> mod_mult_left_eq
  1802 mod_mult_distrib_mod   -> mod_mult_eq
  1803 nat_mod_add_left_eq    -> mod_add_left_eq
  1804 nat_mod_add_right_eq   -> mod_add_right_eq
  1805 nat_mod_div_trivial    -> mod_div_trivial
  1806 nat_mod_mod_trivial    -> mod_mod_trivial
  1807 zdiv_zadd_self1        -> div_add_self1
  1808 zdiv_zadd_self2        -> div_add_self2
  1809 zdiv_zmult_self1       -> div_mult_self2_is_id
  1810 zdiv_zmult_self2       -> div_mult_self1_is_id
  1811 zdvd_triv_left         -> dvd_triv_left
  1812 zdvd_triv_right        -> dvd_triv_right
  1813 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1814 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1815 zmod_zadd_left_eq      -> mod_add_left_eq
  1816 zmod_zadd_right_eq     -> mod_add_right_eq
  1817 zmod_zadd_self1        -> mod_add_self1
  1818 zmod_zadd_self2        -> mod_add_self2
  1819 zmod_zadd1_eq          -> mod_add_eq
  1820 zmod_zdiff1_eq         -> mod_diff_eq
  1821 zmod_zdvd_zmod         -> mod_mod_cancel
  1822 zmod_zmod_cancel       -> mod_mod_cancel
  1823 zmod_zmult_self1       -> mod_mult_self2_is_0
  1824 zmod_zmult_self2       -> mod_mult_self1_is_0
  1825 zmod_1                 -> mod_by_1
  1826 zdiv_1                 -> div_by_1
  1827 zdvd_abs1              -> abs_dvd_iff
  1828 zdvd_abs2              -> dvd_abs_iff
  1829 zdvd_refl              -> dvd_refl
  1830 zdvd_trans             -> dvd_trans
  1831 zdvd_zadd              -> dvd_add
  1832 zdvd_zdiff             -> dvd_diff
  1833 zdvd_zminus_iff        -> dvd_minus_iff
  1834 zdvd_zminus2_iff       -> minus_dvd_iff
  1835 zdvd_zmultD            -> dvd_mult_right
  1836 zdvd_zmultD2           -> dvd_mult_left
  1837 zdvd_zmult_mono        -> mult_dvd_mono
  1838 zdvd_0_right           -> dvd_0_right
  1839 zdvd_0_left            -> dvd_0_left_iff
  1840 zdvd_1_left            -> one_dvd
  1841 zminus_dvd_iff         -> minus_dvd_iff
  1842 
  1843 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1844 
  1845 * The real numbers offer decimal input syntax: 12.34 is translated
  1846 into 1234/10^2. This translation is not reversed upon output.
  1847 
  1848 * Theory Library/Polynomial defines an abstract type 'a poly of
  1849 univariate polynomials with coefficients of type 'a.  In addition to
  1850 the standard ring operations, it also supports div and mod.  Code
  1851 generation is also supported, using list-style constructors.
  1852 
  1853 * Theory Library/Inner_Product defines a class of real_inner for real
  1854 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1855 => real.  Class real_inner is a subclass of real_normed_vector from
  1856 theory RealVector.
  1857 
  1858 * Theory Library/Product_Vector provides instances for the product
  1859 type 'a * 'b of several classes from RealVector and Inner_Product.
  1860 Definitions of addition, subtraction, scalar multiplication, norms,
  1861 and inner products are included.
  1862 
  1863 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1864 addition to the field operations, numerals and case syntax are also
  1865 supported.
  1866 
  1867 * Theory Library/Diagonalize provides constructive version of Cantor's
  1868 first diagonalization argument.
  1869 
  1870 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1871 zlcm (for int); carried together from various gcd/lcm developements in
  1872 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1873 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1874 may recover tupled syntax as follows:
  1875 
  1876     hide (open) const gcd
  1877     abbreviation gcd where
  1878       "gcd == (%(a, b). GCD.gcd a b)"
  1879     notation (output)
  1880       GCD.gcd ("gcd '(_, _')")
  1881 
  1882 The same works for lcm, zgcd, zlcm.
  1883 
  1884 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1885 instantiations for algebraic structures.  Removed some duplicate
  1886 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1887 
  1888 * ML antiquotation @{code} takes a constant as argument and generates
  1889 corresponding code in background and inserts name of the corresponding
  1890 resulting ML value/function/datatype constructor binding in place.
  1891 All occurrences of @{code} with a single ML block are generated
  1892 simultaneously.  Provides a generic and safe interface for
  1893 instrumentalizing code generation.  See
  1894 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1895 In future you ought to refrain from ad-hoc compiling generated SML
  1896 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1897 cannot refer to constants for which user-defined serializations are
  1898 set.  Refer to the corresponding ML counterpart directly in that
  1899 cases.
  1900 
  1901 * Command 'rep_datatype': instead of theorem names the command now
  1902 takes a list of terms denoting the constructors of the type to be
  1903 represented as datatype.  The characteristic theorems have to be
  1904 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1905 have disappeared in favour of existing ones:
  1906 
  1907     unit_induct                 ~> unit.induct
  1908     prod_induct                 ~> prod.induct
  1909     sum_induct                  ~> sum.induct
  1910     Suc_Suc_eq                  ~> nat.inject
  1911     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1912 
  1913 
  1914 *** HOL-Algebra ***
  1915 
  1916 * New locales for orders and lattices where the equivalence relation
  1917 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1918 locales use a record structure with field eq for the equivalence.
  1919 
  1920 * New theory of factorial domains.
  1921 
  1922 * Units_l_inv and Units_r_inv are now simp rules by default.
  1923 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1924 and/or r_inv will now also require deletion of these lemmas.
  1925 
  1926 * Renamed the following theorems, INCOMPATIBILITY:
  1927 
  1928 UpperD ~> Upper_memD
  1929 LowerD ~> Lower_memD
  1930 least_carrier ~> least_closed
  1931 greatest_carrier ~> greatest_closed
  1932 greatest_Lower_above ~> greatest_Lower_below
  1933 one_zero ~> carrier_one_zero
  1934 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1935 
  1936 
  1937 *** HOL-Nominal ***
  1938 
  1939 * Nominal datatypes can now contain type-variables.
  1940 
  1941 * Commands 'nominal_inductive' and 'equivariance' work with local
  1942 theory targets.
  1943 
  1944 * Nominal primrec can now works with local theory targets and its
  1945 specification syntax now conforms to the general format as seen in
  1946 'inductive' etc.
  1947 
  1948 * Method "perm_simp" honours the standard simplifier attributes
  1949 (no_asm), (no_asm_use) etc.
  1950 
  1951 * The new predicate #* is defined like freshness, except that on the
  1952 left hand side can be a set or list of atoms.
  1953 
  1954 * Experimental command 'nominal_inductive2' derives strong induction
  1955 principles for inductive definitions.  In contrast to
  1956 'nominal_inductive', which can only deal with a fixed number of
  1957 binders, it can deal with arbitrary expressions standing for sets of
  1958 atoms to be avoided.  The only inductive definition we have at the
  1959 moment that needs this generalisation is the typing rule for Lets in
  1960 the algorithm W:
  1961 
  1962  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1963  -----------------------------------------------------------------
  1964          Gamma |- Let x be t1 in t2 : T2
  1965 
  1966 In this rule one wants to avoid all the binders that are introduced by
  1967 "close Gamma T1".  We are looking for other examples where this
  1968 feature might be useful.  Please let us know.
  1969 
  1970 
  1971 *** HOLCF ***
  1972 
  1973 * Reimplemented the simplification procedure for proving continuity
  1974 subgoals.  The new simproc is extensible; users can declare additional
  1975 continuity introduction rules with the attribute [cont2cont].
  1976 
  1977 * The continuity simproc now uses a different introduction rule for
  1978 solving continuity subgoals on terms with lambda abstractions.  In
  1979 some rare cases the new simproc may fail to solve subgoals that the
  1980 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1981 Potential INCOMPATIBILITY.
  1982 
  1983 * Command 'fixrec': specification syntax now conforms to the general
  1984 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1985 examples.  INCOMPATIBILITY.
  1986 
  1987 
  1988 *** ZF ***
  1989 
  1990 * Proof of Zorn's Lemma for partial orders.
  1991 
  1992 
  1993 *** ML ***
  1994 
  1995 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1996 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1997 depends on multithreading, so timouts will not work before Poly/ML
  1998 5.2.1!
  1999 
  2000 * High-level support for concurrent ML programming, see
  2001 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2002 particularly convenient to organize independent functional
  2003 computations.  The concept of "synchronized variables" provides a
  2004 higher-order interface for components with shared state, avoiding the
  2005 delicate details of mutexes and condition variables.  (Requires
  2006 Poly/ML 5.2.1 or later.)
  2007 
  2008 * ML bindings produced via Isar commands are stored within the Isar
  2009 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2010 become thread-safe and work with undo as expected (concerning
  2011 top-level bindings, not side-effects on global references).
  2012 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2013 compiler at runtime; really global bindings need to be given outside a
  2014 theory.  (Requires Poly/ML 5.2 or later.)
  2015 
  2016 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2017 context.  Top-level ML bindings are stored within the proof context in
  2018 a purely sequential fashion, disregarding the nested proof structure.
  2019 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2020 proof.  (Requires Poly/ML 5.2 or later.)
  2021 
  2022 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2023 and Method.setup, as well as Isar commands 'attribute_setup' and
  2024 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2025 existing code accordingly, or use plain 'setup' together with old
  2026 Method.add_method.
  2027 
  2028 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2029 to 'a -> thm, while results are always tagged with an authentic oracle
  2030 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2031 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2032 accordingly.  Note that extra performance may be gained by producing
  2033 the cterm carefully, avoiding slow Thm.cterm_of.
  2034 
  2035 * Simplified interface for defining document antiquotations via
  2036 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2037 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2038 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2039 examples.
  2040 
  2041 * More systematic treatment of long names, abstract name bindings, and
  2042 name space operations.  Basic operations on qualified names have been
  2043 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2044 Long_Name.append.  Old type bstring has been mostly replaced by
  2045 abstract type binding (see structure Binding), which supports precise
  2046 qualification by packages and local theory targets, as well as proper
  2047 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2048 bstring values into Binding.name, or better pass through abstract
  2049 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2050 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2051 
  2052 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2053 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2054 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2055 
  2056 * Disposed old type and term read functions (Sign.read_def_typ,
  2057 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2058 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2059 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2060 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2061 resort for legacy applications.
  2062 
  2063 * Disposed old declarations, tactics, tactic combinators that refer to
  2064 the simpset or claset of an implicit theory (such as Addsimps,
  2065 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2066 embedded ML text, or local_simpset_of with a proper context passed as
  2067 explicit runtime argument.
  2068 
  2069 * Rules and tactics that read instantiations (read_instantiate,
  2070 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2071 context, which is required for parsing and type-checking.  Moreover,
  2072 the variables are specified as plain indexnames, not string encodings
  2073 thereof.  INCOMPATIBILITY.
  2074 
  2075 * Generic Toplevel.add_hook interface allows to analyze the result of
  2076 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2077 for theorem dependency output of transactions resulting in a new
  2078 theory state.
  2079 
  2080 * ML antiquotations: block-structured compilation context indicated by
  2081 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2082 
  2083   @{binding name}                         - basic name binding
  2084   @{let ?pat = term}                      - term abbreviation (HO matching)
  2085   @{note name = fact}                     - fact abbreviation
  2086   @{thm fact}                             - singleton fact (with attributes)
  2087   @{thms fact}                            - general fact (with attributes)
  2088   @{lemma prop by method}                 - singleton goal
  2089   @{lemma prop by meth1 meth2}            - singleton goal
  2090   @{lemma prop1 ... propN by method}      - general goal
  2091   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2092   @{lemma (open) ...}                     - open derivation
  2093 
  2094 
  2095 *** System ***
  2096 
  2097 * The Isabelle "emacs" tool provides a specific interface to invoke
  2098 Proof General / Emacs, with more explicit failure if that is not
  2099 installed (the old isabelle-interface script silently falls back on
  2100 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2101 installation location of the Proof General distribution.
  2102 
  2103 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2104 the Isabelle process into a JVM/Scala application.  See
  2105 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2106 process wrapper has been discontinued.)
  2107 
  2108 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2109 
  2110 * Various status messages (with exact source position information) are
  2111 emitted, if proper markup print mode is enabled.  This allows
  2112 user-interface components to provide detailed feedback on internal
  2113 prover operations.
  2114 
  2115 
  2116 
  2117 New in Isabelle2008 (June 2008)
  2118 -------------------------------
  2119 
  2120 *** General ***
  2121 
  2122 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2123 and updated, with formally checked references as hyperlinks.
  2124 
  2125 * Theory loader: use_thy (and similar operations) no longer set the
  2126 implicit ML context, which was occasionally hard to predict and in
  2127 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2128 provides a proper context already.
  2129 
  2130 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2131 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2132 'use' within a theory file will do the job.
  2133 
  2134 * Name space merge now observes canonical order, i.e. the second space
  2135 is inserted into the first one, while existing entries in the first
  2136 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2137 swap theory imports.
  2138 
  2139 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2140 INCOMPATIBILITY in identifier syntax etc.
  2141 
  2142 * Outer syntax: string tokens no longer admit escaped white space,
  2143 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2144 white space without escapes.
  2145 
  2146 * Outer syntax: string tokens may contain arbitrary character codes
  2147 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2148 "foo_bar".
  2149 
  2150 
  2151 *** Pure ***
  2152 
  2153 * Context-dependent token translations.  Default setup reverts locally
  2154 fixed variables, and adds hilite markup for undeclared frees.
  2155 
  2156 * Unused theorems can be found using the new command 'unused_thms'.
  2157 There are three ways of invoking it:
  2158 
  2159 (1) unused_thms
  2160      Only finds unused theorems in the current theory.
  2161 
  2162 (2) unused_thms thy_1 ... thy_n -
  2163      Finds unused theorems in the current theory and all of its ancestors,
  2164      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2165 
  2166 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2167      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2168      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2169      their ancestors.
  2170 
  2171 In order to increase the readability of the list produced by
  2172 unused_thms, theorems that have been created by a particular instance
  2173 of a theory command such as 'inductive' or 'function' are considered
  2174 to belong to the same "group", meaning that if at least one theorem in
  2175 this group is used, the other theorems in the same group are no longer
  2176 reported as unused.  Moreover, if all theorems in the group are
  2177 unused, only one theorem in the group is displayed.
  2178 
  2179 Note that proof objects have to be switched on in order for
  2180 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2181 usually the case when using Proof General with the default settings).
  2182 
  2183 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2184 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2185 duplicate fact bindings, or even accidental fact duplications.  Note
  2186 that tools may maintain dynamically scoped facts systematically, using
  2187 PureThy.add_thms_dynamic.
  2188 
  2189 * Command 'hide' now allows to hide from "fact" name space as well.
  2190 
  2191 * Eliminated destructive theorem database, simpset, claset, and
  2192 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2193 update of theories within ML code.
  2194 
  2195 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2196 INCOMPATIBILITY, object-logics depending on former Pure require
  2197 additional setup PureThy.old_appl_syntax_setup; object-logics
  2198 depending on former CPure need to refer to Pure.
  2199 
  2200 * Commands 'use' and 'ML' are now purely functional, operating on
  2201 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2202 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2203 INCOMPATIBILITY.
  2204 
  2205 * Command 'setup': discontinued implicit version with ML reference.
  2206 
  2207 * Instantiation target allows for simultaneous specification of class
  2208 instance operations together with an instantiation proof.
  2209 Type-checking phase allows to refer to class operations uniformly.
  2210 See src/HOL/Complex/Complex.thy for an Isar example and
  2211 src/HOL/Library/Eval.thy for an ML example.
  2212 
  2213 * Indexing of literal facts: be more serious about including only
  2214 facts from the visible specification/proof context, but not the
  2215 background context (locale etc.).  Affects `prop` notation and method
  2216 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2217 situations.
  2218 
  2219 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2220 "(open)" option, which used to expose internal bound variables to the
  2221 proof text.
  2222 
  2223 * Isar statements: removed obsolete case "rule_context".
  2224 INCOMPATIBILITY, better use explicit fixes/assumes.
  2225 
  2226 * Locale proofs: default proof step now includes 'unfold_locales';
  2227 hence 'proof' without argument may be used to unfold locale
  2228 predicates.
  2229 
  2230 
  2231 *** Document preparation ***
  2232 
  2233 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2234 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2235 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2236 spot); renamed link color from "darkblue" to "linkcolor" (default
  2237 value unchanged, can be redefined via \definecolor); no longer sets
  2238 "a4paper" option (unnecessary or even intrusive).
  2239 
  2240 * Antiquotation @{lemma A method} proves proposition A by the given
  2241 method (either a method name or a method name plus (optional) method
  2242 arguments in parentheses) and prints A just like @{prop A}.
  2243 
  2244 
  2245 *** HOL ***
  2246 
  2247 * New primrec package.  Specification syntax conforms in style to
  2248 definition/function/....  No separate induction rule is provided.  The
  2249 "primrec" command distinguishes old-style and new-style specifications
  2250 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2251 When adjusting theories, beware: constants stemming from new-style
  2252 primrec specifications have authentic syntax.
  2253 
  2254 * Metis prover is now an order of magnitude faster, and also works
  2255 with multithreading.
  2256 
  2257 * Metis: the maximum number of clauses that can be produced from a
  2258 theorem is now given by the attribute max_clauses.  Theorems that
  2259 exceed this number are ignored, with a warning printed.
  2260 
  2261 * Sledgehammer no longer produces structured proofs by default. To
  2262 enable, declare [[sledgehammer_full = true]].  Attributes
  2263 reconstruction_modulus, reconstruction_sorts renamed
  2264 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2265 
  2266 * Method "induct_scheme" derives user-specified induction rules
  2267 from well-founded induction and completeness of patterns. This factors
  2268 out some operations that are done internally by the function package
  2269 and makes them available separately.  See
  2270 src/HOL/ex/Induction_Scheme.thy for examples.
  2271 
  2272 * More flexible generation of measure functions for termination
  2273 proofs: Measure functions can be declared by proving a rule of the
  2274 form "is_measure f" and giving it the [measure_function] attribute.
  2275 The "is_measure" predicate is logically meaningless (always true), and
  2276 just guides the heuristic.  To find suitable measure functions, the
  2277 termination prover sets up the goal "is_measure ?f" of the appropriate
  2278 type and generates all solutions by prolog-style backwards proof using
  2279 the declared rules.
  2280 
  2281 This setup also deals with rules like 
  2282 
  2283   "is_measure f ==> is_measure (list_size f)"
  2284 
  2285 which accommodates nested datatypes that recurse through lists.
  2286 Similar rules are predeclared for products and option types.
  2287 
  2288 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2289 
  2290   INCOMPATIBILITIES:
  2291 
  2292   - Definitions of overloaded constants on sets have to be replaced by
  2293     definitions on => and bool.
  2294 
  2295   - Some definitions of overloaded operators on sets can now be proved
  2296     using the definitions of the operators on => and bool.  Therefore,
  2297     the following theorems have been renamed:
  2298 
  2299       subset_def   -> subset_eq
  2300       psubset_def  -> psubset_eq
  2301       set_diff_def -> set_diff_eq
  2302       Compl_def    -> Compl_eq
  2303       Sup_set_def  -> Sup_set_eq
  2304       Inf_set_def  -> Inf_set_eq
  2305       sup_set_def  -> sup_set_eq
  2306       inf_set_def  -> inf_set_eq
  2307 
  2308   - Due to the incompleteness of the HO unification algorithm, some
  2309     rules such as subst may require manual instantiation, if some of
  2310     the unknowns in the rule is a set.
  2311 
  2312   - Higher order unification and forward proofs:
  2313     The proof pattern
  2314 
  2315       have "P (S::'a set)" <...>
  2316       then have "EX S. P S" ..
  2317 
  2318     no longer works (due to the incompleteness of the HO unification
  2319     algorithm) and must be replaced by the pattern
  2320 
  2321       have "EX S. P S"
  2322       proof
  2323         show "P S" <...>
  2324       qed
  2325 
  2326   - Calculational reasoning with subst (or similar rules):
  2327     The proof pattern
  2328 
  2329       have "P (S::'a set)" <...>
  2330       also have "S = T" <...>
  2331       finally have "P T" .
  2332 
  2333     no longer works (for similar reasons as the previous example) and
  2334     must be replaced by something like
  2335 
  2336       have "P (S::'a set)" <...>
  2337       moreover have "S = T" <...>
  2338       ultimately have "P T" by simp
  2339 
  2340   - Tactics or packages written in ML code:
  2341     Code performing pattern matching on types via
  2342 
  2343       Type ("set", [T]) => ...
  2344 
  2345     must be rewritten. Moreover, functions like strip_type or
  2346     binder_types no longer return the right value when applied to a
  2347     type of the form
  2348 
  2349       T1 => ... => Tn => U => bool
  2350 
  2351     rather than
  2352 
  2353       T1 => ... => Tn => U set
  2354 
  2355 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2356 Wellfounded_Relations to theory Wellfounded.
  2357 
  2358 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2359 
  2360 * Class finite no longer treats UNIV as class parameter.  Use class
  2361 enum from theory Library/Enum instead to achieve a similar effect.
  2362 INCOMPATIBILITY.
  2363 
  2364 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2365 and "Cons".  INCOMPATIBILITY.
  2366 
  2367 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2368 Potential INCOMPATIBILITY.
  2369 
  2370 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2371 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2372 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2373 
  2374 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2375 the same name in theory Orderings:
  2376 
  2377   less_trans
  2378   less_linear
  2379   le_imp_less_or_eq
  2380   le_less_trans
  2381   less_le_trans
  2382   less_not_sym
  2383   less_asym
  2384 
  2385 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2386 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2387 and different variable names.
  2388 
  2389 * Library/Option_ord.thy: Canonical order on option type.
  2390 
  2391 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2392 finite maps.
  2393 
  2394 * Library/Countable.thy: Type class for countable types.
  2395 
  2396 * Theory Int: The representation of numerals has changed.  The infix
  2397 operator BIT and the bit datatype with constructors B0 and B1 have
  2398 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2399 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2400 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2401 accordingly.
  2402 
  2403 * Theory Nat: definition of <= and < on natural numbers no longer
  2404 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2405 le_def and less_def have disappeared.  Consider lemmas not_less
  2406 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2407 
  2408 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2409 (whose purpose mainly is for various fold_set functionals) have been
  2410 abandoned in favor of the existing algebraic classes
  2411 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2412 lower_semilattice (resp. upper_semilattice) and linorder.
  2413 INCOMPATIBILITY.
  2414 
  2415 * Theory Transitive_Closure: induct and cases rules now declare proper
  2416 case_names ("base" and "step").  INCOMPATIBILITY.
  2417 
  2418 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2419 lattices.  The form set-specific version is available as
  2420 Inductive.lfp_ordinal_induct_set.
  2421 
  2422 * Renamed theorems "power.simps" to "power_int.simps".
  2423 INCOMPATIBILITY.
  2424 
  2425 * Class semiring_div provides basic abstract properties of semirings
  2426 with division and modulo operations.  Subsumes former class dvd_mod.
  2427 
  2428 * Merged theories IntDef, Numeral and IntArith into unified theory
  2429 Int.  INCOMPATIBILITY.
  2430 
  2431 * Theory Library/Code_Index: type "index" now represents natural
  2432 numbers rather than integers.  INCOMPATIBILITY.
  2433 
  2434 * New class "uminus" with operation "uminus" (split of from class
  2435 "minus" which now only has operation "minus", binary).
  2436 INCOMPATIBILITY.
  2437 
  2438 * Constants "card", "internal_split", "option_map" now with authentic
  2439 syntax.  INCOMPATIBILITY.
  2440 
  2441 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2442 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2443 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2444 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2445 Sup_set_def, le_def, less_def, option_map_def now with object
  2446 equality.  INCOMPATIBILITY.
  2447 
  2448 * Records. Removed K_record, and replaced it by pure lambda term
  2449 %x. c. The simplifier setup is now more robust against eta expansion.
  2450 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2451 
  2452 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2453 
  2454 * Library/ListVector: new theory of arithmetic vector operations.
  2455 
  2456 * Library/Order_Relation: new theory of various orderings as sets of
  2457 pairs.  Defines preorders, partial orders, linear orders and
  2458 well-orders on sets and on types.
  2459 
  2460 
  2461 *** ZF ***
  2462 
  2463 * Renamed some theories to allow to loading both ZF and HOL in the
  2464 same session:
  2465 
  2466   Datatype  -> Datatype_ZF
  2467   Inductive -> Inductive_ZF
  2468   Int       -> Int_ZF
  2469   IntDiv    -> IntDiv_ZF
  2470   Nat       -> Nat_ZF
  2471   List      -> List_ZF
  2472   Main      -> Main_ZF
  2473 
  2474 INCOMPATIBILITY: ZF theories that import individual theories below
  2475 Main might need to be adapted.  Regular theory Main is still
  2476 available, as trivial extension of Main_ZF.
  2477 
  2478 
  2479 *** ML ***
  2480 
  2481 * ML within Isar: antiquotation @{const name} or @{const
  2482 name(typargs)} produces statically-checked Const term.
  2483 
  2484 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2485 (of the same name).  Removed obsolete print command.
  2486 
  2487 * Removed obsolete "use_legacy_bindings" function.
  2488 
  2489 * The ``print mode'' is now a thread-local value derived from a global
  2490 template (the former print_mode reference), thus access becomes
  2491 non-critical.  The global print_mode reference is for session
  2492 management only; user-code should use print_mode_value,
  2493 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2494 
  2495 * Functions system/system_out provide a robust way to invoke external
  2496 shell commands, with propagation of interrupts (requires Poly/ML
  2497 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2498 
  2499 
  2500 *** System ***
  2501 
  2502 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2503 in accordance with Proof General 3.7, which prefers GNU emacs.
  2504 
  2505 * isatool tty runs Isabelle process with plain tty interaction;
  2506 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2507 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2508 
  2509 * isatool browser now works with Cygwin as well, using general
  2510 "javapath" function defined in Isabelle process environment.
  2511 
  2512 * YXML notation provides a simple and efficient alternative to
  2513 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2514 isatool yxml as described in the Isabelle system manual.
  2515 
  2516 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2517 provides general wrapper for managing an Isabelle process in a robust
  2518 fashion, with ``cooked'' output from stdin/stderr.
  2519 
  2520 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2521 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2522 
  2523 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2524 way of changing the user's settings is via
  2525 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2526 script.
  2527 
  2528 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2529 cores of the underlying machine, which is a good starting point for
  2530 optimal performance tuning.  The corresponding usedir option -M allows
  2531 "max" as an alias for "0".  WARNING: does not work on certain versions
  2532 of Mac OS (with Poly/ML 5.1).
  2533 
  2534 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2535 adverse effect of Isabelle flooding interactive front-ends (notably
  2536 ProofGeneral / XEmacs).
  2537 
  2538 
  2539 
  2540 New in Isabelle2007 (November 2007)
  2541 -----------------------------------
  2542 
  2543 *** General ***
  2544 
  2545 * More uniform information about legacy features, notably a
  2546 warning/error of "Legacy feature: ...", depending on the state of the
  2547 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2548 legacy features will disappear eventually.
  2549 
  2550 * Theory syntax: the header format ``theory A = B + C:'' has been
  2551 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2552 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2553 
  2554 * Theory syntax: the old non-Isar theory file format has been
  2555 discontinued altogether.  Note that ML proof scripts may still be used
  2556 with Isar theories; migration is usually quite simple with the ML
  2557 function use_legacy_bindings.  INCOMPATIBILITY.
  2558 
  2559 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2560 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2561 quotes.
  2562 
  2563 * Theory loader: be more serious about observing the static theory
  2564 header specifications (including optional directories), but not the
  2565 accidental file locations of previously successful loads.  The strict
  2566 update policy of former update_thy is now already performed by
  2567 use_thy, so the former has been removed; use_thys updates several
  2568 theories simultaneously, just as 'imports' within a theory header
  2569 specification, but without merging the results.  Potential
  2570 INCOMPATIBILITY: may need to refine theory headers and commands
  2571 ROOT.ML which depend on load order.
  2572 
  2573 * Theory loader: optional support for content-based file
  2574 identification, instead of the traditional scheme of full physical
  2575 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2576 (cf. the system manual).  The new scheme allows to work with
  2577 non-finished theories in persistent session images, such that source
  2578 files may be moved later on without requiring reloads.
  2579 
  2580 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2581 file (with the same base name as the theory) are considered a legacy
  2582 feature, which will disappear eventually. Even now, the theory loader
  2583 no longer maintains dependencies on such files.
  2584 
  2585 * Syntax: the scope for resolving ambiguities via type-inference is
  2586 now limited to individual terms, instead of whole simultaneous
  2587 specifications as before. This greatly reduces the complexity of the
  2588 syntax module and improves flexibility by separating parsing and
  2589 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2590 'fixes' etc.) are required in rare situations.
  2591 
  2592 * Syntax: constants introduced by new-style packages ('definition',
  2593 'abbreviation' etc.) are passed through the syntax module in
  2594 ``authentic mode''. This means that associated mixfix annotations
  2595 really stick to such constants, independently of potential name space
  2596 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2597 trees are represented slightly differently, may need to adapt syntax
  2598 translations accordingly. Use CONST marker in 'translations' and
  2599 @{const_syntax} antiquotation in 'parse_translation' etc.
  2600 
  2601 * Legacy goal package: reduced interface to the bare minimum required
  2602 to keep existing proof scripts running.  Most other user-level
  2603 functions are now part of the OldGoals structure, which is *not* open
  2604 by default (consider isatool expandshort before open OldGoals).
  2605 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2606 these tend to cause confusion about the actual goal (!) context being
  2607 used here, which is not necessarily the same as the_context().
  2608 
  2609 * Command 'find_theorems': supports "*" wild-card in "name:"
  2610 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2611 support a specific search form (see ProofGeneral/CHANGES).
  2612 
  2613 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2614 by default, which means that "prems" (and also "fixed variables") are
  2615 suppressed from proof state output.  Note that the ProofGeneral
  2616 settings mechanism allows to change and save options persistently, but
  2617 older versions of Isabelle will fail to start up if a negative prems
  2618 limit is imposed.
  2619 
  2620 * Local theory targets may be specified by non-nested blocks of
  2621 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2622 contain definitions, theorems etc., including any derived mechanism
  2623 that has been implemented on top of these primitives.  This concept
  2624 generalizes the existing ``theorem (in ...)'' towards more versatility
  2625 and scalability.
  2626 
  2627 * Proof General interface: proper undo of final 'end' command;
  2628 discontinued Isabelle/classic mode (ML proof scripts).
  2629 
  2630 
  2631 *** Document preparation ***
  2632 
  2633 * Added antiquotation @{theory name} which prints the given name,
  2634 after checking that it refers to a valid ancestor theory in the
  2635 current context.
  2636 
  2637 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2638 check the given source text as ML type/structure, printing verbatim.
  2639 
  2640 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2641 "c args == rhs" given in the current context.  (Any number of
  2642 arguments may be given on the LHS.)
  2643 
  2644 
  2645 *** Pure ***
  2646 
  2647 * The 'class' package offers a combination of axclass and locale to
  2648 achieve Haskell-like type classes in Isabelle.  Definitions and
  2649 theorems within a class context produce both relative results (with
  2650 implicit parameters according to the locale context), and polymorphic
  2651 constants with qualified polymorphism (according to the class
  2652 context).  Within the body context of a 'class' target, a separate
  2653 syntax layer ("user space type system") takes care of converting
  2654 between global polymorphic consts and internal locale representation.
  2655 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2656 "isatool doc classes" provides a tutorial.
  2657 
  2658 * Generic code generator framework allows to generate executable
  2659 code for ML and Haskell (including Isabelle classes).  A short usage
  2660 sketch:
  2661 
  2662     internal compilation:
  2663         export_code <list of constants (term syntax)> in SML
  2664     writing SML code to a file:
  2665         export_code <list of constants (term syntax)> in SML <filename>
  2666     writing OCaml code to a file:
  2667         export_code <list of constants (term syntax)> in OCaml <filename>
  2668     writing Haskell code to a bunch of files:
  2669         export_code <list of constants (term syntax)> in Haskell <filename>
  2670 
  2671     evaluating closed propositions to True/False using code generation:
  2672         method ``eval''
  2673 
  2674 Reasonable default setup of framework in HOL.
  2675 
  2676 Theorem attributs for selecting and transforming function equations theorems:
  2677 
  2678     [code fun]:        select a theorem as function equation for a specific constant
  2679     [code fun del]:    deselect a theorem as function equation for a specific constant
  2680     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2681     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2682 
  2683 User-defined serializations (target in {SML, OCaml, Haskell}):
  2684 
  2685     code_const <and-list of constants (term syntax)>
  2686       {(target) <and-list of const target syntax>}+
  2687 
  2688     code_type <and-list of type constructors>
  2689       {(target) <and-list of type target syntax>}+
  2690 
  2691     code_instance <and-list of instances>
  2692       {(target)}+
  2693         where instance ::= <type constructor> :: <class>
  2694 
  2695     code_class <and_list of classes>
  2696       {(target) <and-list of class target syntax>}+
  2697         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2698 
  2699 code_instance and code_class only are effective to target Haskell.
  2700 
  2701 For example usage see src/HOL/ex/Codegenerator.thy and
  2702 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2703 generation from Isabelle/HOL theories is available via "isatool doc
  2704 codegen".
  2705 
  2706 * Code generator: consts in 'consts_code' Isar commands are now
  2707 referred to by usual term syntax (including optional type
  2708 annotations).
  2709 
  2710 * Command 'no_translations' removes translation rules from theory
  2711 syntax.
  2712 
  2713 * Overloaded definitions are now actually checked for acyclic
  2714 dependencies.  The overloading scheme is slightly more general than
  2715 that of Haskell98, although Isabelle does not demand an exact
  2716 correspondence to type class and instance declarations.
  2717 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2718 exotic versions of overloading -- at the discretion of the user!
  2719 
  2720 Polymorphic constants are represented via type arguments, i.e. the
  2721 instantiation that matches an instance against the most general
  2722 declaration given in the signature.  For example, with the declaration
  2723 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2724 as c(nat).  Overloading is essentially simultaneous structural
  2725 recursion over such type arguments.  Incomplete specification patterns
  2726 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2727 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2728 Command 'print_theory' outputs the normalized system of recursive
  2729 equations, see section "definitions".
  2730 
  2731 * Configuration options are maintained within the theory or proof
  2732 context (with name and type bool/int/string), providing a very simple
  2733 interface to a poor-man's version of general context data.  Tools may
  2734 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2735 these values using Config.get etc.  Users may change options via an
  2736 associated attribute of the same name.  This form of context
  2737 declaration works particularly well with commands 'declare' or
  2738 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2739 very easy to avoid global references, which would not observe Isar
  2740 toplevel undo/redo and fail to work with multithreading.
  2741 
  2742 Various global ML references of Pure and HOL have been turned into
  2743 configuration options:
  2744 
  2745   Unify.search_bound		unify_search_bound
  2746   Unify.trace_bound		unify_trace_bound
  2747   Unify.trace_simp		unify_trace_simp
  2748   Unify.trace_types		unify_trace_types
  2749   Simplifier.simp_depth_limit	simp_depth_limit
  2750   Blast.depth_limit		blast_depth_limit
  2751   DatatypeProp.dtK		datatype_distinctness_limit
  2752   fast_arith_neq_limit  	fast_arith_neq_limit
  2753   fast_arith_split_limit	fast_arith_split_limit
  2754 
  2755 * Named collections of theorems may be easily installed as context
  2756 data using the functor NamedThmsFun (see also
  2757 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2758 attributes; there is also a toplevel print command.  This facility is
  2759 just a common case of general context data, which is the preferred way
  2760 for anything more complex than just a list of facts in canonical
  2761 order.
  2762 
  2763 * Isar: command 'declaration' augments a local theory by generic
  2764 declaration functions written in ML.  This enables arbitrary content
  2765 being added to the context, depending on a morphism that tells the
  2766 difference of the original declaration context wrt. the application
  2767 context encountered later on.
  2768 
  2769 * Isar: proper interfaces for simplification procedures.  Command
  2770 'simproc_setup' declares named simprocs (with match patterns, and body
  2771 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2772 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2773 
  2774 * Isar: an extra pair of brackets around attribute declarations
  2775 abbreviates a theorem reference involving an internal dummy fact,
  2776 which will be ignored later --- only the effect of the attribute on
  2777 the background context will persist.  This form of in-place
  2778 declarations is particularly useful with commands like 'declare' and
  2779 'using', for example ``have A using [[simproc a]] by simp''.
  2780 
  2781 * Isar: method "assumption" (and implicit closing of subproofs) now
  2782 takes simple non-atomic goal assumptions into account: after applying
  2783 an assumption as a rule the resulting subgoals are solved by atomic
  2784 assumption steps.  This is particularly useful to finish 'obtain'
  2785 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2786 without referring to the original premise "!!x. P x ==> thesis" in the
  2787 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2788 more permissive.
  2789 
  2790 * Isar: implicit use of prems from the Isar proof context is
  2791 considered a legacy feature.  Common applications like ``have A .''
  2792 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2793 referencing facts explicitly here improves readability and
  2794 maintainability of proof texts.
  2795 
  2796 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2797 the obtained context from the course of reasoning!  For example:
  2798 
  2799   assume "EX x y. A x & B y"   -- "any previous fact"
  2800   then guess x and y by clarify
  2801 
  2802 This technique is potentially adventurous, depending on the facts and
  2803 proof tools being involved here.
  2804 
  2805 * Isar: known facts from the proof context may be specified as literal
  2806 propositions, using ASCII back-quote syntax.  This works wherever
  2807 named facts used to be allowed so far, in proof commands, proof
  2808 methods, attributes etc.  Literal facts are retrieved from the context
  2809 according to unification of type and term parameters.  For example,
  2810 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2811 theorems in the current context, then these are valid literal facts:
  2812 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2813 
  2814 There is also a proof method "fact" which does the same composition
  2815 for explicit goal states, e.g. the following proof texts coincide with
  2816 certain special cases of literal facts:
  2817 
  2818   have "A" by fact                 ==  note `A`
  2819   have "A ==> B" by fact           ==  note `A ==> B`
  2820   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2821   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2822 
  2823 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2824 outer syntax.  Thus symbolic identifiers may be used without
  2825 additional white space in declarations like this: ``assume *: A''.
  2826 
  2827 * Isar: 'print_facts' prints all local facts of the current context,
  2828 both named and unnamed ones.
  2829 
  2830 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2831 
  2832   def x == "t" and y == "u"
  2833 
  2834 * Isar: added command 'unfolding', which is structurally similar to
  2835 'using', but affects both the goal state and facts by unfolding given
  2836 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2837 'unfolded' attribute may be replaced by first-class proof text.
  2838 
  2839 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2840 and command 'unfolding' now all support object-level equalities
  2841 (potentially conditional).  The underlying notion of rewrite rule is
  2842 analogous to the 'rule_format' attribute, but *not* that of the
  2843 Simplifier (which is usually more generous).
  2844 
  2845 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2846 premises of a theorem by n. Useful in conjunction with drule.
  2847 
  2848 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2849 method expression within a sandbox consisting of the first N
  2850 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2851 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2852 simplifies all new goals that emerge from applying rule foo to the
  2853 originally first one.
  2854 
  2855 * Isar: schematic goals are no longer restricted to higher-order
  2856 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2857 expected.
  2858 
  2859 * Isar: the conclusion of a long theorem statement is now either
  2860 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2861 (essentially a disjunction of cases with local parameters and
  2862 assumptions).  The latter allows to express general elimination rules
  2863 adequately; in this notation common elimination rules look like this:
  2864 
  2865   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2866     assumes "EX x. P x"
  2867     obtains x where "P x"
  2868 
  2869   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2870     assumes "A & B"
  2871     obtains A and B
  2872 
  2873   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2874     assumes "A | B"
  2875     obtains
  2876       A
  2877     | B
  2878 
  2879 The subsequent classical rules even refer to the formal "thesis"
  2880 explicitly:
  2881 
  2882   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2883     obtains "~ thesis"
  2884 
  2885   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2886     obtains "thesis ==> something"
  2887 
  2888 The actual proof of an 'obtains' statement is analogous to that of the
  2889 Isar proof element 'obtain', only that there may be several cases.
  2890 Optional case names may be specified in parentheses; these will be
  2891 available both in the present proof and as annotations in the
  2892 resulting rule, for later use with the 'cases' method (cf. attribute
  2893 case_names).
  2894 
  2895 * Isar: the assumptions of a long theorem statement are available as
  2896 "assms" fact in the proof context.  This is more appropriate than the
  2897 (historical) "prems", which refers to all assumptions of the current
  2898 context, including those from the target locale, proof body etc.
  2899 
  2900 * Isar: 'print_statement' prints theorems from the current theory or
  2901 proof context in long statement form, according to the syntax of a
  2902 top-level lemma.
  2903 
  2904 * Isar: 'obtain' takes an optional case name for the local context
  2905 introduction rule (default "that").
  2906 
  2907 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2908 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2909 to occur.
  2910 
  2911 * Pure: syntax "CONST name" produces a fully internalized constant
  2912 according to the current context.  This is particularly useful for
  2913 syntax translations that should refer to internal constant
  2914 representations independently of name spaces.
  2915 
  2916 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2917 instead of "FOO ". This allows multiple binder declarations to coexist
  2918 in the same context.  INCOMPATIBILITY.
  2919 
  2920 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2921 primitive that also works in a locale context (both for constants and
  2922 fixed variables). Type declaration and internal syntactic representation
  2923 of given constants retrieved from the context. Likewise, the
  2924 'no_notation' command allows to remove given syntax annotations from the
  2925 current context.
  2926 
  2927 * Isar/locales: new derived specification elements 'axiomatization',
  2928 'definition', 'abbreviation', which support type-inference, admit
  2929 object-level specifications (equality, equivalence).  See also the
  2930 isar-ref manual.  Examples:
  2931 
  2932   axiomatization
  2933     eq  (infix "===" 50) where
  2934     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2935 
  2936   definition "f x y = x + y + 1"
  2937   definition g where "g x = f x x"
  2938 
  2939   abbreviation
  2940     neq  (infix "=!=" 50) where
  2941     "x =!= y == ~ (x === y)"
  2942 
  2943 These specifications may be also used in a locale context.  Then the
  2944 constants being introduced depend on certain fixed parameters, and the
  2945 constant name is qualified by the locale base name.  An internal
  2946 abbreviation takes care for convenient input and output, making the
  2947 parameters implicit and using the original short name.  See also
  2948 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2949 entities from a monomorphic theory.
  2950 
  2951 Presently, abbreviations are only available 'in' a target locale, but
  2952 not inherited by general import expressions.  Also note that
  2953 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2954 'translations' in common applications.  The "no_abbrevs" print mode
  2955 prevents folding of abbreviations in term output.
  2956 
  2957 Concrete syntax is attached to specified constants in internal form,
  2958 independently of name spaces.  The parse tree representation is
  2959 slightly different -- use 'notation' instead of raw 'syntax', and
  2960 'translations' with explicit "CONST" markup to accommodate this.
  2961 
  2962 * Pure/Isar: unified syntax for new-style specification mechanisms
  2963 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2964 full type inference and dummy patterns ("_").  For example:
  2965 
  2966   definition "K x _ = x"
  2967 
  2968   inductive conj for A B
  2969   where "A ==> B ==> conj A B"
  2970 
  2971 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2972 the current context.  Print mode "no_abbrevs" prevents inversion of
  2973 abbreviations on output.
  2974 
  2975 * Isar/locales: improved parameter handling: use of locales "var" and
  2976 "struct" no longer necessary; - parameter renamings are no longer
  2977 required to be injective.  For example, this allows to define
  2978 endomorphisms as locale endom = homom mult mult h.
  2979 
  2980 * Isar/locales: changed the way locales with predicates are defined.
  2981 Instead of accumulating the specification, the imported expression is
  2982 now an interpretation.  INCOMPATIBILITY: different normal form of
  2983 locale expressions.  In particular, in interpretations of locales with
  2984 predicates, goals repesenting already interpreted fragments are not
  2985 removed automatically.  Use methods `intro_locales' and
  2986 `unfold_locales'; see below.
  2987 
  2988 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2989 provide backward reasoning on locales predicates.  The methods are
  2990 aware of interpretations and discharge corresponding goals.
  2991 `intro_locales' is less aggressive then `unfold_locales' and does not
  2992 unfold predicates to assumptions.
  2993 
  2994 * Isar/locales: the order in which locale fragments are accumulated
  2995 has changed.  This enables to override declarations from fragments due
  2996 to interpretations -- for example, unwanted simp rules.
  2997 
  2998 * Isar/locales: interpretation in theories and proof contexts has been
  2999 extended.  One may now specify (and prove) equations, which are
  3000 unfolded in interpreted theorems.  This is useful for replacing
  3001 defined concepts (constants depending on locale parameters) by
  3002 concepts already existing in the target context.  Example:
  3003 
  3004   interpretation partial_order ["op <= :: [int, int] => bool"]
  3005     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3006 
  3007 Typically, the constant `partial_order.less' is created by a
  3008 definition specification element in the context of locale
  3009 partial_order.
  3010 
  3011 * Method "induct": improved internal context management to support
  3012 local fixes and defines on-the-fly. Thus explicit meta-level
  3013 connectives !!  and ==> are rarely required anymore in inductive goals
  3014 (using object-logic connectives for this purpose has been long
  3015 obsolete anyway). Common proof patterns are explained in
  3016 src/HOL/Induct/Common_Patterns.thy, see also
  3017 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3018 examples.
  3019 
  3020 * Method "induct": improved handling of simultaneous goals. Instead of
  3021 introducing object-level conjunction, the statement is now split into
  3022 several conclusions, while the corresponding symbolic cases are nested
  3023 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3024 see src/HOL/Induct/Common_Patterns.thy, for example.
  3025 
  3026 * Method "induct": mutual induction rules are now specified as a list
  3027 of rule sharing the same induction cases. HOL packages usually provide
  3028 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3029 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3030 mutual induction rules differently, i.e. like this:
  3031 
  3032   (induct rule: foo_bar.inducts)
  3033   (induct set: foo bar)
  3034   (induct pred: foo bar)
  3035   (induct type: foo bar)
  3036 
  3037 The ML function ProjectRule.projections turns old-style rules into the
  3038 new format.
  3039 
  3040 * Method "coinduct": dual of induction, see
  3041 src/HOL/Library/Coinductive_List.thy for various examples.
  3042 
  3043 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3044 considered a legacy feature.
  3045 
  3046 * Attribute "symmetric" produces result with standardized schematic
  3047 variables (index 0).  Potential INCOMPATIBILITY.
  3048 
  3049 * Simplifier: by default the simplifier trace only shows top level
  3050 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3051 default. Thus there is less danger of being flooded by the trace. The
  3052 trace indicates where parts have been suppressed.
  3053   
  3054 * Provers/classical: removed obsolete classical version of elim_format
  3055 attribute; classical elim/dest rules are now treated uniformly when
  3056 manipulating the claset.
  3057 
  3058 * Provers/classical: stricter checks to ensure that supplied intro,
  3059 dest and elim rules are well-formed; dest and elim rules must have at
  3060 least one premise.
  3061 
  3062 * Provers/classical: attributes dest/elim/intro take an optional
  3063 weight argument for the rule (just as the Pure versions).  Weights are
  3064 ignored by automated tools, but determine the search order of single
  3065 rule steps.
  3066 
  3067 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3068 where the body does not mention the bound variable.  Note that dummy
  3069 patterns implicitly depend on their context of bounds, which makes
  3070 "{_. _}" match any set comprehension as expected.  Potential
  3071 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3072 constant "_idtdummy" in the binding position.
  3073 
  3074 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3075 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3076 for example "A -> B" => "Pi A (%_. B)".
  3077 
  3078 * Pure: 'class_deps' command visualizes the subclass relation, using
  3079 the graph browser tool.
  3080 
  3081 * Pure: 'print_theory' now suppresses certain internal declarations by
  3082 default; use '!' option for full details.
  3083 
  3084 
  3085 *** HOL ***
  3086 
  3087 * Method "metis" proves goals by applying the Metis general-purpose
  3088 resolution prover (see also http://gilith.com/software/metis/).
  3089 Examples are in the directory MetisExamples.  WARNING: the
  3090 Isabelle/HOL-Metis integration does not yet work properly with
  3091 multi-threading.
  3092   
  3093 * Command 'sledgehammer' invokes external automatic theorem provers as
  3094 background processes.  It generates calls to the "metis" method if
  3095 successful. These can be pasted into the proof.  Users do not have to
  3096 wait for the automatic provers to return.  WARNING: does not really
  3097 work with multi-threading.
  3098 
  3099 * New "auto_quickcheck" feature tests outermost goal statements for
  3100 potential counter-examples.  Controlled by ML references
  3101 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3102 5000 milliseconds).  Fails silently if statements is outside of
  3103 executable fragment, or any other codgenerator problem occurs.
  3104 
  3105 * New constant "undefined" with axiom "undefined x = undefined".
  3106 
  3107 * Added class "HOL.eq", allowing for code generation with polymorphic
  3108 equality.
  3109 
  3110 * Some renaming of class constants due to canonical name prefixing in
  3111 the new 'class' package:
  3112 
  3113     HOL.abs ~> HOL.abs_class.abs
  3114     HOL.divide ~> HOL.divide_class.divide
  3115     0 ~> HOL.zero_class.zero
  3116     1 ~> HOL.one_class.one
  3117     op + ~> HOL.plus_class.plus
  3118     op - ~> HOL.minus_class.minus
  3119     uminus ~> HOL.minus_class.uminus
  3120     op * ~> HOL.times_class.times
  3121     op < ~> HOL.ord_class.less
  3122     op <= > HOL.ord_class.less_eq
  3123     Nat.power ~> Power.power_class.power
  3124     Nat.size ~> Nat.size_class.size
  3125     Numeral.number_of ~> Numeral.number_class.number_of
  3126     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3127     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3128     Orderings.min ~> Orderings.ord_class.min
  3129     Orderings.max ~> Orderings.ord_class.max
  3130     Divides.op div ~> Divides.div_class.div
  3131     Divides.op mod ~> Divides.div_class.mod
  3132     Divides.op dvd ~> Divides.div_class.dvd
  3133 
  3134 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3135 
  3136 a) User-defined constants using any of the names "plus", "minus",
  3137 "times", "less" or "less_eq". The standard syntax translations for
  3138 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3139 names.
  3140 
  3141 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3142 INCOMPATIBILITY: use more specific names.
  3143 
  3144 c) Permutative equations (e.g. "a + b = b + a")
  3145 Since the change of names also changes the order of terms, permutative
  3146 rewrite rules may get applied in a different order. Experience shows
  3147 that this is rarely the case (only two adaptions in the whole Isabelle
  3148 distribution).  INCOMPATIBILITY: rewrite proofs
  3149 
  3150 d) ML code directly refering to constant names
  3151 This in general only affects hand-written proof tactics, simprocs and
  3152 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3153 Consider using @{const_name} antiquotation.
  3154 
  3155 * New class "default" with associated constant "default".
  3156 
  3157 * Function "sgn" is now overloaded and available on int, real, complex
  3158 (and other numeric types), using class "sgn".  Two possible defs of
  3159 sgn are given as equational assumptions in the classes sgn_if and
  3160 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3161 INCOMPATIBILITY.
  3162 
  3163 * Locale "partial_order" now unified with class "order" (cf. theory
  3164 Orderings), added parameter "less".  INCOMPATIBILITY.
  3165 
  3166 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3167 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3168 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3169 
  3170 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3171 changed order of proof goals in instance proofs.
  3172 
  3173 * The transitivity reasoner for partial and linear orders is set up
  3174 for classes "order" and "linorder".  Instances of the reasoner are available
  3175 in all contexts importing or interpreting the corresponding locales.
  3176 Method "order" invokes the reasoner separately; the reasoner
  3177 is also integrated with the Simplifier as a solver.  Diagnostic
  3178 command 'print_orders' shows the available instances of the reasoner
  3179 in the current context.
  3180 
  3181 * Localized monotonicity predicate in theory "Orderings"; integrated
  3182 lemmas max_of_mono and min_of_mono with this predicate.
  3183 INCOMPATIBILITY.
  3184 
  3185 * Formulation of theorem "dense" changed slightly due to integration
  3186 with new class dense_linear_order.
  3187 
  3188 * Uniform lattice theory development in HOL.
  3189 
  3190     constants "meet" and "join" now named "inf" and "sup"
  3191     constant "Meet" now named "Inf"
  3192 
  3193     classes "meet_semilorder" and "join_semilorder" now named
  3194       "lower_semilattice" and "upper_semilattice"
  3195     class "lorder" now named "lattice"
  3196     class "comp_lat" now named "complete_lattice"
  3197 
  3198     Instantiation of lattice classes allows explicit definitions
  3199     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3200 
  3201   INCOMPATIBILITY.  Theorem renames:
  3202 
  3203     meet_left_le            ~> inf_le1
  3204     meet_right_le           ~> inf_le2
  3205     join_left_le            ~> sup_ge1
  3206     join_right_le           ~> sup_ge2
  3207     meet_join_le            ~> inf_sup_ord
  3208     le_meetI                ~> le_infI
  3209     join_leI                ~> le_supI
  3210     le_meet                 ~> le_inf_iff
  3211     le_join                 ~> ge_sup_conv
  3212     meet_idempotent         ~> inf_idem
  3213     join_idempotent         ~> sup_idem
  3214     meet_comm               ~> inf_commute
  3215     join_comm               ~> sup_commute
  3216     meet_leI1               ~> le_infI1
  3217     meet_leI2               ~> le_infI2
  3218     le_joinI1               ~> le_supI1
  3219     le_joinI2               ~> le_supI2
  3220     meet_assoc              ~> inf_assoc
  3221     join_assoc              ~> sup_assoc
  3222     meet_left_comm          ~> inf_left_commute
  3223     meet_left_idempotent    ~> inf_left_idem
  3224     join_left_comm          ~> sup_left_commute
  3225     join_left_idempotent    ~> sup_left_idem
  3226     meet_aci                ~> inf_aci
  3227     join_aci                ~> sup_aci
  3228     le_def_meet             ~> le_iff_inf
  3229     le_def_join             ~> le_iff_sup
  3230     join_absorp2            ~> sup_absorb2
  3231     join_absorp1            ~> sup_absorb1
  3232     meet_absorp1            ~> inf_absorb1
  3233     meet_absorp2            ~> inf_absorb2
  3234     meet_join_absorp        ~> inf_sup_absorb
  3235     join_meet_absorp        ~> sup_inf_absorb
  3236     distrib_join_le         ~> distrib_sup_le
  3237     distrib_meet_le         ~> distrib_inf_le
  3238 
  3239     add_meet_distrib_left   ~> add_inf_distrib_left
  3240     add_join_distrib_left   ~> add_sup_distrib_left
  3241     is_join_neg_meet        ~> is_join_neg_inf
  3242     is_meet_neg_join        ~> is_meet_neg_sup
  3243     add_meet_distrib_right  ~> add_inf_distrib_right
  3244     add_join_distrib_right  ~> add_sup_distrib_right
  3245     add_meet_join_distribs  ~> add_sup_inf_distribs
  3246     join_eq_neg_meet        ~> sup_eq_neg_inf
  3247     meet_eq_neg_join        ~> inf_eq_neg_sup
  3248     add_eq_meet_join        ~> add_eq_inf_sup
  3249     meet_0_imp_0            ~> inf_0_imp_0
  3250     join_0_imp_0            ~> sup_0_imp_0
  3251     meet_0_eq_0             ~> inf_0_eq_0
  3252     join_0_eq_0             ~> sup_0_eq_0
  3253     neg_meet_eq_join        ~> neg_inf_eq_sup
  3254     neg_join_eq_meet        ~> neg_sup_eq_inf
  3255     join_eq_if              ~> sup_eq_if
  3256 
  3257     mono_meet               ~> mono_inf
  3258     mono_join               ~> mono_sup
  3259     meet_bool_eq            ~> inf_bool_eq
  3260     join_bool_eq            ~> sup_bool_eq
  3261     meet_fun_eq             ~> inf_fun_eq
  3262     join_fun_eq             ~> sup_fun_eq
  3263     meet_set_eq             ~> inf_set_eq
  3264     join_set_eq             ~> sup_set_eq
  3265     meet1_iff               ~> inf1_iff
  3266     meet2_iff               ~> inf2_iff
  3267     meet1I                  ~> inf1I
  3268     meet2I                  ~> inf2I
  3269     meet1D1                 ~> inf1D1
  3270     meet2D1                 ~> inf2D1
  3271     meet1D2                 ~> inf1D2
  3272     meet2D2                 ~> inf2D2
  3273     meet1E                  ~> inf1E
  3274     meet2E                  ~> inf2E
  3275     join1_iff               ~> sup1_iff
  3276     join2_iff               ~> sup2_iff
  3277     join1I1                 ~> sup1I1
  3278     join2I1                 ~> sup2I1
  3279     join1I1                 ~> sup1I1
  3280     join2I2                 ~> sup1I2
  3281     join1CI                 ~> sup1CI
  3282     join2CI                 ~> sup2CI
  3283     join1E                  ~> sup1E
  3284     join2E                  ~> sup2E
  3285 
  3286     is_meet_Meet            ~> is_meet_Inf
  3287     Meet_bool_def           ~> Inf_bool_def
  3288     Meet_fun_def            ~> Inf_fun_def
  3289     Meet_greatest           ~> Inf_greatest
  3290     Meet_lower              ~> Inf_lower
  3291     Meet_set_def            ~> Inf_set_def
  3292 
  3293     Sup_def                 ~> Sup_Inf
  3294     Sup_bool_eq             ~> Sup_bool_def
  3295     Sup_fun_eq              ~> Sup_fun_def
  3296     Sup_set_eq              ~> Sup_set_def
  3297 
  3298     listsp_meetI            ~> listsp_infI
  3299     listsp_meet_eq          ~> listsp_inf_eq
  3300 
  3301     meet_min                ~> inf_min
  3302     join_max                ~> sup_max
  3303 
  3304 * Added syntactic class "size"; overloaded constant "size" now has
  3305 type "'a::size ==> bool"
  3306 
  3307 * Internal reorganisation of `size' of datatypes: size theorems
  3308 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3309 simplification rules by default!); theorems "prod.size" now named
  3310 "*.size".
  3311 
  3312 * Class "div" now inherits from class "times" rather than "type".
  3313 INCOMPATIBILITY.
  3314 
  3315 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3316 Linorder etc.  have disappeared; operations defined in terms of
  3317 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3318 
  3319 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3320 
  3321 * HOL-Word: New extensive library and type for generic, fixed size
  3322 machine words, with arithemtic, bit-wise, shifting and rotating
  3323 operations, reflection into int, nat, and bool lists, automation for
  3324 linear arithmetic (by automatic reflection into nat or int), including
  3325 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3326 arithmetic type classes, supporting automatic simplification of
  3327 numerals on all operations.
  3328 
  3329 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3330 
  3331 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3332 
  3333 * Code generator library theories:
  3334   - Code_Integer represents HOL integers by big integer literals in target
  3335     languages.
  3336   - Code_Char represents HOL characters by character literals in target
  3337     languages.
  3338   - Code_Char_chr like Code_Char, but also offers treatment of character
  3339     codes; includes Code_Integer.
  3340   - Executable_Set allows to generate code for finite sets using lists.
  3341   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3342     denominator).
  3343   - Executable_Real implements a subset of real numbers, namly those
  3344     representable by rational numbers.
  3345   - Efficient_Nat implements natural numbers by integers, which in general will
  3346     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3347     includes Code_Integer.
  3348   - Code_Index provides an additional datatype index which is mapped to
  3349     target-language built-in integers.
  3350   - Code_Message provides an additional datatype message_string which is isomorphic to
  3351     strings; messages are mapped to target-language strings.
  3352 
  3353 * New package for inductive predicates
  3354 
  3355   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3356 
  3357     inductive
  3358       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3359       for z_1 :: U_1 and ... and z_n :: U_m
  3360     where
  3361       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3362     | ...
  3363 
  3364   with full support for type-inference, rather than
  3365 
  3366     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3367 
  3368     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3369     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3370 
  3371     inductive "s z_1 ... z_m"
  3372     intros
  3373       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3374       ...
  3375 
  3376   For backward compatibility, there is a wrapper allowing inductive
  3377   sets to be defined with the new package via
  3378 
  3379     inductive_set
  3380       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3381       for z_1 :: U_1 and ... and z_n :: U_m
  3382     where
  3383       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3384     | ...
  3385 
  3386   or
  3387 
  3388     inductive_set
  3389       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3390       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3391       for z_1 :: U_1 and ... and z_n :: U_m
  3392     where
  3393       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3394     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3395     | ...
  3396 
  3397   if the additional syntax "p ..." is required.
  3398 
  3399   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3400   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3401 
  3402   INCOMPATIBILITIES:
  3403 
  3404   - Since declaration and definition of inductive sets or predicates
  3405     is no longer separated, abbreviations involving the newly
  3406     introduced sets or predicates must be specified together with the
  3407     introduction rules after the 'where' keyword (see above), rather
  3408     than before the actual inductive definition.
  3409 
  3410   - The variables in induction and elimination rules are now
  3411     quantified in the order of their occurrence in the introduction
  3412     rules, rather than in alphabetical order. Since this may break
  3413     some proofs, these proofs either have to be repaired, e.g. by
  3414     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3415     statements of the form
  3416 
  3417       case (rule_i a_i_1 ... a_i_{k_i})
  3418 
  3419     or the old order of quantification has to be restored by explicitly adding
  3420     meta-level quantifiers in the introduction rules, i.e.
  3421 
  3422       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3423 
  3424   - The format of the elimination rules is now
  3425 
  3426       p z_1 ... z_m x_1 ... x_n ==>
  3427         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3428         ==> ... ==> P
  3429 
  3430     for predicates and
  3431 
  3432       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3433         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3434         ==> ... ==> P
  3435 
  3436     for sets rather than
  3437 
  3438       x : s z_1 ... z_m ==>
  3439         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3440         ==> ... ==> P
  3441 
  3442     This may require terms in goals to be expanded to n-tuples
  3443     (e.g. using case_tac or simplification with the split_paired_all
  3444     rule) before the above elimination rule is applicable.
  3445 
  3446   - The elimination or case analysis rules for (mutually) inductive
  3447     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3448     list of rules "p_1_..._p_k.elims" is no longer available.
  3449 
  3450 * New package "function"/"fun" for general recursive functions,
  3451 supporting mutual and nested recursion, definitions in local contexts,
  3452 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3453 for small examples, and the separate tutorial on the function
  3454 package. The old recdef "package" is still available as before, but
  3455 users are encouraged to use the new package.
  3456 
  3457 * Method "lexicographic_order" automatically synthesizes termination
  3458 relations as lexicographic combinations of size measures. 
  3459 
  3460 * Case-expressions allow arbitrary constructor-patterns (including
  3461 "_") and take their order into account, like in functional
  3462 programming.  Internally, this is translated into nested
  3463 case-expressions; missing cases are added and mapped to the predefined
  3464 constant "undefined". In complicated cases printing may no longer show
  3465 the original input but the internal form. Lambda-abstractions allow
  3466 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3467 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3468 variable.
  3469 
  3470 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3471 is an abbreviation for "of_nat :: nat => int". The simplification
  3472 rules for "of_nat" have been changed to work like "int" did
  3473 previously.  Potential INCOMPATIBILITY:
  3474   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3475   - of_nat_diff and of_nat_mult are no longer default simp rules
  3476 
  3477 * Method "algebra" solves polynomial equations over (semi)rings using
  3478 Groebner bases. The (semi)ring structure is defined by locales and the
  3479 tool setup depends on that generic context. Installing the method for
  3480 a specific type involves instantiating the locale and possibly adding
  3481 declarations for computation on the coefficients.  The method is
  3482 already instantiated for natural numbers and for the axiomatic class
  3483 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3484 CALCULEMUS 2007 for the general principles underlying this
  3485 architecture of context-aware proof-tools.
  3486 
  3487 * Method "ferrack" implements quantifier elimination over
  3488 special-purpose dense linear orders using locales (analogous to
  3489 "algebra"). The method is already installed for class
  3490 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3491 rat, etc.
  3492 
  3493 * Former constant "List.op @" now named "List.append".  Use ML
  3494 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3495 circumvent possible incompatibilities when working on ML level.
  3496 
  3497 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3498 
  3499 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3500 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3501 
  3502 * New syntax for Haskell-like list comprehension (input only), eg.
  3503 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3504 
  3505 * The special syntax for function "filter" has changed from [x :
  3506 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3507 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3508 
  3509 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3510 defined on nat only, as an abbreviation for [a..<Suc b]
  3511 INCOMPATIBILITY.
  3512 
  3513 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3514 
  3515 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3516 
  3517 * New lemma collection field_simps (an extension of ring_simps) for
  3518 manipulating (in)equations involving division. Multiplies with all
  3519 denominators that can be proved to be non-zero (in equations) or
  3520 positive/negative (in inequations).
  3521 
  3522 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3523 have been improved and renamed to ring_simps, group_simps and
  3524 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3525 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3526 
  3527 * Theory Library/Commutative_Ring: switched from recdef to function
  3528 package; constants add, mul, pow now curried.  Infix syntax for
  3529 algebraic operations.
  3530 
  3531 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3532 INCOMPATIBILITY.
  3533 
  3534 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3535 INCOMPATIBILITY.
  3536 
  3537 * HOL/records: generalised field-update to take a function on the
  3538 field rather than the new value: r(|A := x|) is translated to A_update
  3539 (K x) r The K-combinator that is internally used is called K_record.
  3540 INCOMPATIBILITY: Usage of the plain update functions has to be
  3541 adapted.
  3542  
  3543 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3544 * x = 0, which are required for a semiring.  Richer structures do not
  3545 inherit from semiring_0 anymore, because this property is a theorem
  3546 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3547 there is more to prove, but this is mostly trivial.
  3548 
  3549 * Class "recpower" is generalized to arbitrary monoids, not just
  3550 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3551 commutativity or semiring properties additionally.
  3552 
  3553 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3554 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3555 better use 'abbreviation'.
  3556 
  3557 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3558 
  3559 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3560 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3561 significant changes for setting up numeral syntax for types:
  3562   - New constants Numeral.pred and Numeral.succ instead
  3563       of former Numeral.bin_pred and Numeral.bin_succ.
  3564   - Use integer operations instead of bin_add, bin_mult and so on.
  3565   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3566   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3567 
  3568 See src/HOL/Integ/IntArith.thy for an example setup.
  3569 
  3570 * Command 'normal_form' computes the normal form of a term that may
  3571 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3572 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3573 heavy-duty computations because the functions are compiled to ML
  3574 first.  Correspondingly, a method "normalization" is provided.  See
  3575 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3576 
  3577 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3578 25 like -->); output depends on the "iff" print_mode, the default is
  3579 "A = B" (with priority 50).
  3580 
  3581 * Relations less (<) and less_eq (<=) are also available on type bool.
  3582 Modified syntax to disallow nesting without explicit parentheses,
  3583 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3584 INCOMPATIBILITY.
  3585 
  3586 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3587 
  3588 * Relation composition operator "op O" now has precedence 75 and binds
  3589 stronger than union and intersection. INCOMPATIBILITY.
  3590 
  3591 * The old set interval syntax "{m..n(}" (and relatives) has been
  3592 removed.  Use "{m..<n}" (and relatives) instead.
  3593 
  3594 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3595 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3596 ``declare [[simproc del: neq]]''.
  3597 
  3598 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3599 True/False.
  3600 
  3601 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3602 
  3603 * Theorem setsum_mult renamed to setsum_right_distrib.
  3604 
  3605 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3606 ``rule'' method.
  3607 
  3608 * Reimplemented methods "sat" and "satx", with several improvements:
  3609 goals no longer need to be stated as "<prems> ==> False", equivalences
  3610 (i.e. "=" on type bool) are handled, variable names of the form
  3611 "lit_<n>" are no longer reserved, significant speedup.
  3612 
  3613 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3614 zChaff is still supported as well.
  3615 
  3616 * 'inductive' and 'datatype': provide projections of mutual rules,
  3617 bundled as foo_bar.inducts;
  3618 
  3619 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3620 Library.
  3621 
  3622 * Library: moved theory Accessible_Part to main HOL.
  3623 
  3624 * Library: added theory Coinductive_List of potentially infinite lists
  3625 as greatest fixed-point.
  3626 
  3627 * Library: added theory AssocList which implements (finite) maps as
  3628 association lists.
  3629 
  3630 * Method "evaluation" solves goals (i.e. a boolean expression)
  3631 efficiently by compiling it to ML.  The goal is "proved" (via an
  3632 oracle) if it evaluates to True.
  3633 
  3634 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3635 also when invoked by the simplifier.  This results in the Simplifier
  3636 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3637 Configuration option fast_arith_split_limit=0 recovers the old
  3638 behavior.
  3639 
  3640 * Support for hex (0x20) and binary (0b1001) numerals.
  3641 
  3642 * New method: reify eqs (t), where eqs are equations for an
  3643 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3644 parameter, computes a term s::'b and a list xs::'a list and proves the
  3645 theorem I xs s = t. This is also known as reification or quoting. The
  3646 resulting theorem is applied to the subgoal to substitute t with I xs
  3647 s.  If t is omitted, the subgoal itself is reified.
  3648 
  3649 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3650 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3651 where f is supposed to be a computable function (in the sense of code
  3652 generattion). The method uses reify to compute s and xs as above then
  3653 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3654 r and finally gets the theorem t = r, which is again applied to the
  3655 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3656 
  3657 * Reflection: Automatic reification now handels binding, an example is
  3658 available in src/HOL/ex/ReflectionEx.thy
  3659 
  3660 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3661 command 'statespace' that is similar to 'record', but introduces an
  3662 abstract specification based on the locale infrastructure instead of
  3663 HOL types.  This leads to extra flexibility in composing state spaces,
  3664 in particular multiple inheritance and renaming of components.
  3665 
  3666 
  3667 *** HOL-Complex ***
  3668 
  3669 * Hyperreal: Functions root and sqrt are now defined on negative real
  3670 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3671 Nonnegativity side conditions have been removed from many lemmas, so
  3672 that more subgoals may now be solved by simplification; potential
  3673 INCOMPATIBILITY.
  3674 
  3675 * Real: new type classes formalize real normed vector spaces and
  3676 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3677 and norm :: 'a => real.
  3678 
  3679 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3680 reals into other types. The overloaded constant Reals :: 'a set is now
  3681 defined as range of_real; potential INCOMPATIBILITY.
  3682 
  3683 * Real: proper support for ML code generation, including 'quickcheck'.
  3684 Reals are implemented as arbitrary precision rationals.
  3685 
  3686 * Hyperreal: Several constants that previously worked only for the
  3687 reals have been generalized, so they now work over arbitrary vector
  3688 spaces. Type annotations may need to be added in some cases; potential
  3689 INCOMPATIBILITY.
  3690 
  3691   Infinitesimal  :: ('a::real_normed_vector) star set
  3692   HFinite        :: ('a::real_normed_vector) star set
  3693   HInfinite      :: ('a::real_normed_vector) star set
  3694   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3695   monad          :: ('a::real_normed_vector) star => 'a star set
  3696   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3697   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3698   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3699   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3700   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3701   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3702   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3703   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3704   sgn            :: 'a::real_normed_vector => 'a
  3705   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3706 
  3707 * Complex: Some complex-specific constants are now abbreviations for
  3708 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3709 hnorm.  Other constants have been entirely removed in favor of the
  3710 polymorphic versions (INCOMPATIBILITY):
  3711 
  3712   approx        <-- capprox
  3713   HFinite       <-- CFinite
  3714   HInfinite     <-- CInfinite
  3715   Infinitesimal <-- CInfinitesimal
  3716   monad         <-- cmonad
  3717   galaxy        <-- cgalaxy
  3718   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3719   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3720   (ns)deriv     <-- (ns)cderiv
  3721 
  3722 
  3723 *** HOL-Algebra ***
  3724 
  3725 * Formalisation of ideals and the quotient construction over rings.
  3726 
  3727 * Order and lattice theory no longer based on records.
  3728 INCOMPATIBILITY.
  3729 
  3730 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3731 greatest_closed.  INCOMPATIBILITY.
  3732 
  3733 * Method algebra is now set up via an attribute.  For examples see
  3734 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3735 of algebraic structures.
  3736 
  3737 * Renamed theory CRing to Ring.
  3738 
  3739 
  3740 *** HOL-Nominal ***
  3741 
  3742 * Substantial, yet incomplete support for nominal datatypes (binding
  3743 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3744 src/HOL/Nominal/Examples.  Prospective users should consult
  3745 http://isabelle.in.tum.de/nominal/
  3746 
  3747 
  3748 *** ML ***
  3749 
  3750 * ML basics: just one true type int, which coincides with IntInf.int
  3751 (even on SML/NJ).
  3752 
  3753 * ML within Isar: antiquotations allow to embed statically-checked
  3754 formal entities in the source, referring to the context available at
  3755 compile-time.  For example:
  3756 
  3757 ML {* @{sort "{zero,one}"} *}
  3758 ML {* @{typ "'a => 'b"} *}
  3759 ML {* @{term "%x. x"} *}
  3760 ML {* @{prop "x == y"} *}
  3761 ML {* @{ctyp "'a => 'b"} *}
  3762 ML {* @{cterm "%x. x"} *}
  3763 ML {* @{cprop "x == y"} *}
  3764 ML {* @{thm asm_rl} *}
  3765 ML {* @{thms asm_rl} *}
  3766 ML {* @{type_name c} *}
  3767 ML {* @{type_syntax c} *}
  3768 ML {* @{const_name c} *}
  3769 ML {* @{const_syntax c} *}
  3770 ML {* @{context} *}
  3771 ML {* @{theory} *}
  3772 ML {* @{theory Pure} *}
  3773 ML {* @{theory_ref} *}
  3774 ML {* @{theory_ref Pure} *}
  3775 ML {* @{simpset} *}
  3776 ML {* @{claset} *}
  3777 ML {* @{clasimpset} *}
  3778 
  3779 The same works for sources being ``used'' within an Isar context.
  3780 
  3781 * ML in Isar: improved error reporting; extra verbosity with
  3782 ML_Context.trace enabled.
  3783 
  3784 * Pure/General/table.ML: the join operations now works via exceptions
  3785 DUP/SAME instead of type option. This is simpler in simple cases, and
  3786 admits slightly more efficient complex applications.
  3787 
  3788 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3789 use Context.generic instead of just theory.
  3790 
  3791 * Pure: datatype Context.generic joins theory/Proof.context and
  3792 provides some facilities for code that works in either kind of
  3793 context, notably GenericDataFun for uniform theory and proof data.
  3794 
  3795 * Pure: simplified internal attribute type, which is now always
  3796 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3797 local (Proof.context) attributes have been discontinued, while
  3798 minimizing code duplication. Thm.rule_attribute and
  3799 Thm.declaration_attribute build canonical attributes; see also structure
  3800 Context for further operations on Context.generic, notably
  3801 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3802 declarations and definitions.
  3803 
  3804 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3805 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3806 init only required for impure data. INCOMPATIBILITY: empty really need
  3807 to be empty (no dependencies on theory content!)
  3808 
  3809 * Pure/kernel: consts certification ignores sort constraints given in
  3810 signature declarations. (This information is not relevant to the
  3811 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3812 potential INCOMPATIBILITY.
  3813 
  3814 * Pure: axiomatic type classes are now purely definitional, with
  3815 explicit proofs of class axioms and super class relations performed
  3816 internally. See Pure/axclass.ML for the main internal interfaces --
  3817 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3818 AxClass.axiomatize_class/classrel/arity supersede
  3819 Sign.add_classes/classrel/arities.
  3820 
  3821 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3822 global/local versions on theory vs. Proof.context have been
  3823 discontinued; Attrib.syntax and Method.syntax have been adapted
  3824 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3825 attributes, methods, etc.
  3826 
  3827 * Pure: several functions of signature "... -> theory -> theory * ..."
  3828 have been reoriented to "... -> theory -> ... * theory" in order to
  3829 allow natural usage in combination with the ||>, ||>>, |-> and
  3830 fold_map combinators.
  3831 
  3832 * Pure: official theorem names (closed derivations) and additional
  3833 comments (tags) are now strictly separate.  Name hints -- which are
  3834 maintained as tags -- may be attached any time without affecting the
  3835 derivation.
  3836 
  3837 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3838 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3839 achieve the old behaviour.
  3840 
  3841 * Pure: the "Goal" constant is now called "prop", supporting a
  3842 slightly more general idea of ``protecting'' meta-level rule
  3843 statements.
  3844 
  3845 * Pure: Logic.(un)varify only works in a global context, which is now
  3846 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3847 Logic.legacy_(un)varify as temporary workaround.
  3848 
  3849 * Pure: structure Name provides scalable operations for generating
  3850 internal variable names, notably Name.variants etc.  This replaces
  3851 some popular functions from term.ML:
  3852 
  3853   Term.variant		->  Name.variant
  3854   Term.variantlist	->  Name.variant_list
  3855   Term.invent_names	->  Name.invent_list
  3856 
  3857 Note that low-level renaming rarely occurs in new code -- operations
  3858 from structure Variable are used instead (see below).
  3859 
  3860 * Pure: structure Variable provides fundamental operations for proper
  3861 treatment of fixed/schematic variables in a context.  For example,
  3862 Variable.import introduces fixes for schematics of given facts and
  3863 Variable.export reverses the effect (up to renaming) -- this replaces
  3864 various freeze_thaw operations.
  3865 
  3866 * Pure: structure Goal provides simple interfaces for
  3867 init/conclude/finish and tactical prove operations (replacing former
  3868 Tactic.prove).  Goal.prove is the canonical way to prove results
  3869 within a given context; Goal.prove_global is a degraded version for
  3870 theory level goals, including a global Drule.standard.  Note that
  3871 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3872 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3873 in a locale context).
  3874 
  3875 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3876 and type checking (Syntax.check_term etc.), with common combinations
  3877 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3878 which are considered legacy and await removal.
  3879 
  3880 * Pure/Syntax: generic interfaces for type unchecking
  3881 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3882 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3883 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3884 available for convenience, but refer to the very same operations using
  3885 a mere theory instead of a full context.
  3886 
  3887 * Isar: simplified treatment of user-level errors, using exception
  3888 ERROR of string uniformly.  Function error now merely raises ERROR,
  3889 without any side effect on output channels.  The Isar toplevel takes
  3890 care of proper display of ERROR exceptions.  ML code may use plain
  3891 handle/can/try; cat_error may be used to concatenate errors like this:
  3892 
  3893   ... handle ERROR msg => cat_error msg "..."
  3894 
  3895 Toplevel ML code (run directly or through the Isar toplevel) may be
  3896 embedded into the Isar toplevel with exception display/debug like
  3897 this:
  3898 
  3899   Isar.toplevel (fn () => ...)
  3900 
  3901 INCOMPATIBILITY, removed special transform_error facilities, removed
  3902 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3903 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3904 -- use plain ERROR instead.
  3905 
  3906 * Isar: theory setup now has type (theory -> theory), instead of a
  3907 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3908 
  3909 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3910 ProofContext.debug/verbose flags.
  3911 
  3912 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3913 theory before entering a proof state.  Transactions now always see a
  3914 quasi-functional intermediate checkpoint, both in interactive and
  3915 batch mode.
  3916 
  3917 * Isar: simplified interfaces for outer syntax.  Renamed
  3918 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3919 OuterSyntax.add_parsers -- this functionality is now included in
  3920 OuterSyntax.command etc.  INCOMPATIBILITY.
  3921 
  3922 * Simplifier: the simpset of a running simplification process now
  3923 contains a proof context (cf. Simplifier.the_context), which is the
  3924 very context that the initial simpset has been retrieved from (by
  3925 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3926 (solver, looper etc.) may depend on arbitrary proof data.
  3927 
  3928 * Simplifier.inherit_context inherits the proof context (plus the
  3929 local bounds) of the current simplification process; any simproc
  3930 etc. that calls the Simplifier recursively should do this!  Removed
  3931 former Simplifier.inherit_bounds, which is already included here --
  3932 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3933 specify an explicit context using Simplifier.context/theory_context.
  3934 
  3935 * Simplifier/Classical Reasoner: more abstract interfaces
  3936 change_simpset/claset for modifying the simpset/claset reference of a
  3937 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3938 INCOMPATIBILITY.
  3939 
  3940 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3941 "Trueprop" etc.
  3942 
  3943 
  3944 *** System ***
  3945 
  3946 * settings: the default heap location within ISABELLE_HOME_USER now
  3947 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3948 Isabelle installations.
  3949 
  3950 * isabelle-process: option -S (secure mode) disables some critical
  3951 operations, notably runtime compilation and evaluation of ML source
  3952 code.
  3953 
  3954 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3955 
  3956 * Support for parallel execution, using native multicore support of
  3957 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3958 independent theories, according to the given theory header
  3959 specifications. The maximum number of worker threads is specified via
  3960 usedir option -M or the "max-threads" setting in Proof General. A
  3961 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3962 to 6 on a 8-core machine.  User-code needs to observe certain
  3963 guidelines for thread-safe programming, see appendix A in the Isar
  3964 Implementation manual.
  3965 
  3966 
  3967 
  3968 New in Isabelle2005 (October 2005)
  3969 ----------------------------------
  3970 
  3971 *** General ***
  3972 
  3973 * Theory headers: the new header syntax for Isar theories is
  3974 
  3975   theory <name>
  3976   imports <theory1> ... <theoryN>
  3977   uses <file1> ... <fileM>
  3978   begin
  3979 
  3980 where the 'uses' part is optional.  The previous syntax
  3981 
  3982   theory <name> = <theory1> + ... + <theoryN>:
  3983 
  3984 will disappear in the next release.  Use isatool fixheaders to convert
  3985 existing theory files.  Note that there is no change in ancient
  3986 non-Isar theories now, but these will disappear soon.
  3987 
  3988 * Theory loader: parent theories can now also be referred to via
  3989 relative and absolute paths.
  3990 
  3991 * Command 'find_theorems' searches for a list of criteria instead of a
  3992 list of constants. Known criteria are: intro, elim, dest, name:string,
  3993 simp:term, and any term. Criteria can be preceded by '-' to select
  3994 theorems that do not match. Intro, elim, dest select theorems that
  3995 match the current goal, name:s selects theorems whose fully qualified
  3996 name contain s, and simp:term selects all simplification rules whose
  3997 lhs match term.  Any other term is interpreted as pattern and selects
  3998 all theorems matching the pattern. Available in ProofGeneral under
  3999 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4000 
  4001   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4002 
  4003 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4004 matching the current goal as introduction rule and not having "HOL."
  4005 in their name (i.e. not being defined in theory HOL).
  4006 
  4007 * Command 'thms_containing' has been discontinued in favour of
  4008 'find_theorems'; INCOMPATIBILITY.
  4009 
  4010 * Communication with Proof General is now 8bit clean, which means that
  4011 Unicode text in UTF-8 encoding may be used within theory texts (both
  4012 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4013 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4014 
  4015   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4016   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4017 
  4018 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4019 Classical Reasoner.  Typical big applications run around 2 times
  4020 faster.
  4021 
  4022 
  4023 *** Document preparation ***
  4024 
  4025 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4026 of raw sources.  Only those symbols that do not require additional
  4027 LaTeX packages (depending on comments in isabellesym.sty) are
  4028 displayed properly, everything else is left verbatim.  isatool display
  4029 and isatool print are used as front ends (these are subject to the
  4030 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4031 
  4032 * Command tags control specific markup of certain regions of text,
  4033 notably folding and hiding.  Predefined tags include "theory" (for
  4034 theory begin and end), "proof" for proof commands, and "ML" for
  4035 commands involving ML code; the additional tags "visible" and
  4036 "invisible" are unused by default.  Users may give explicit tag
  4037 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4038 interpretation of tags is determined by the LaTeX job during document
  4039 preparation: see option -V of isatool usedir, or options -n and -t of
  4040 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4041 \isadroptag.
  4042 
  4043 Several document versions may be produced at the same time via isatool
  4044 usedir (the generated index.html will link all of them).  Typical
  4045 specifications include ''-V document=theory,proof,ML'' to present
  4046 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4047 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4048 these parts without any formal replacement text.  The Isabelle site
  4049 default settings produce ''document'' and ''outline'' versions as
  4050 specified above.
  4051 
  4052 * Several new antiquotations:
  4053 
  4054   @{term_type term} prints a term with its type annotated;
  4055 
  4056   @{typeof term} prints the type of a term;
  4057 
  4058   @{const const} is the same as @{term const}, but checks that the
  4059   argument is a known logical constant;
  4060 
  4061   @{term_style style term} and @{thm_style style thm} print a term or
  4062   theorem applying a "style" to it
  4063 
  4064   @{ML text}
  4065 
  4066 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4067 definitions, equations, inequations etc., 'concl' printing only the
  4068 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4069 to print the specified premise.  TermStyle.add_style provides an ML
  4070 interface for introducing further styles.  See also the "LaTeX Sugar"
  4071 document practical applications.  The ML antiquotation prints
  4072 type-checked ML expressions verbatim.
  4073 
  4074 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4075 and 'text' support optional locale specification '(in loc)', which
  4076 specifies the default context for interpreting antiquotations.  For
  4077 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4078 
  4079 * Option 'locale=NAME' of antiquotations specifies an alternative
  4080 context interpreting the subsequent argument.  For example: @{thm
  4081 [locale=lattice] inf_assoc}.
  4082 
  4083 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4084 a proof context.
  4085 
  4086 * Proper output of antiquotations for theory commands involving a
  4087 proof context (such as 'locale' or 'theorem (in loc) ...').
  4088 
  4089 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4090 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4091 
  4092 * isatool usedir: new option -C (default true) controls whether option
  4093 -D should include a copy of the original document directory; -C false
  4094 prevents unwanted effects such as copying of administrative CVS data.
  4095 
  4096 
  4097 *** Pure ***
  4098 
  4099 * Considerably improved version of 'constdefs' command.  Now performs
  4100 automatic type-inference of declared constants; additional support for
  4101 local structure declarations (cf. locales and HOL records), see also
  4102 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4103 sequential dependencies of definitions within a single 'constdefs'
  4104 section; moreover, the declared name needs to be an identifier.  If
  4105 all fails, consider to fall back on 'consts' and 'defs' separately.
  4106 
  4107 * Improved indexed syntax and implicit structures.  First of all,
  4108 indexed syntax provides a notational device for subscripted
  4109 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4110 expressions.  Secondly, in a local context with structure
  4111 declarations, number indexes \<^sub>n or the empty index (default
  4112 number 1) refer to a certain fixed variable implicitly; option
  4113 show_structs controls printing of implicit structures.  Typical
  4114 applications of these concepts involve record types and locales.
  4115 
  4116 * New command 'no_syntax' removes grammar declarations (and
  4117 translations) resulting from the given syntax specification, which is
  4118 interpreted in the same manner as for the 'syntax' command.
  4119 
  4120 * 'Advanced' translation functions (parse_translation etc.) may depend
  4121 on the signature of the theory context being presently used for
  4122 parsing/printing, see also isar-ref manual.
  4123 
  4124 * Improved 'oracle' command provides a type-safe interface to turn an
  4125 ML expression of type theory -> T -> term into a primitive rule of
  4126 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4127 is already included here); see also FOL/ex/IffExample.thy;
  4128 INCOMPATIBILITY.
  4129 
  4130 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4131 before); "cI" is no longer bound, use "c.intro" instead.
  4132 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4133 axclasses vs. locales.
  4134 
  4135 * Improved internal renaming of symbolic identifiers -- attach primes
  4136 instead of base 26 numbers.
  4137 
  4138 * New flag show_question_marks controls printing of leading question
  4139 marks in schematic variable names.
  4140 
  4141 * In schematic variable names, *any* symbol following \<^isub> or
  4142 \<^isup> is now treated as part of the base name.  For example, the
  4143 following works without printing of awkward ".0" indexes:
  4144 
  4145   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4146     by simp
  4147 
  4148 * Inner syntax includes (*(*nested*) comments*).
  4149 
  4150 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4151 annotations as "(00...)".
  4152 
  4153 * Clear separation of logical types and nonterminals, where the latter
  4154 may only occur in 'syntax' specifications or type abbreviations.
  4155 Before that distinction was only partially implemented via type class
  4156 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4157 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4158 exotic syntax specifications may require further adaption
  4159 (e.g. Cube/Cube.thy).
  4160 
  4161 * Removed obsolete type class "logic", use the top sort {} instead.
  4162 Note that non-logical types should be declared as 'nonterminals'
  4163 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4164 specifications.
  4165 
  4166 * Attributes 'induct' and 'cases': type or set names may now be
  4167 locally fixed variables as well.
  4168 
  4169 * Simplifier: can now control the depth to which conditional rewriting
  4170 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4171 Limit.
  4172 
  4173 * Simplifier: simplification procedures may now take the current
  4174 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4175 interface), which is very useful for calling the Simplifier
  4176 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4177 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4178 low-level mk_simproc no longer applies Logic.varify internally, to
  4179 allow for use in a context of fixed variables.
  4180 
  4181 * thin_tac now works even if the assumption being deleted contains !!
  4182 or ==>.  More generally, erule now works even if the major premise of
  4183 the elimination rule contains !! or ==>.
  4184 
  4185 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4186 
  4187 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4188 from Pure, which contains all common declarations already.  Both
  4189 theories are defined via plain Isabelle/Isar .thy files.
  4190 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4191 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4192 use isatool fixcpure to adapt your theory and ML sources.
  4193 
  4194 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4195 selections of theorems in named facts via index ranges.
  4196 
  4197 * 'print_theorems': in theory mode, really print the difference
  4198 wrt. the last state (works for interactive theory development only),
  4199 in proof mode print all local facts (cf. 'print_facts');
  4200 
  4201 * 'hide': option '(open)' hides only base names.
  4202 
  4203 * More efficient treatment of intermediate checkpoints in interactive
  4204 theory development.
  4205 
  4206 * Code generator is now invoked via code_module (incremental code
  4207 generation) and code_library (modular code generation, ML structures
  4208 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4209 must be quoted when used as identifiers.
  4210 
  4211 * New 'value' command for reading, evaluating and printing terms using
  4212 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4213 quoted when used as identifier.
  4214 
  4215 
  4216 *** Locales ***
  4217 
  4218 * New commands for the interpretation of locale expressions in
  4219 theories (1), locales (2) and proof contexts (3).  These generate
  4220 proof obligations from the expression specification.  After the
  4221 obligations have been discharged, theorems of the expression are added
  4222 to the theory, target locale or proof context.  The synopsis of the
  4223 commands is a follows:
  4224 
  4225   (1) interpretation expr inst
  4226   (2) interpretation target < expr
  4227   (3) interpret expr inst
  4228 
  4229 Interpretation in theories and proof contexts require a parameter
  4230 instantiation of terms from the current context.  This is applied to
  4231 specifications and theorems of the interpreted expression.
  4232 Interpretation in locales only permits parameter renaming through the
  4233 locale expression.  Interpretation is smart in that interpretations
  4234 that are active already do not occur in proof obligations, neither are
  4235 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4236 inspect active interpretations of a particular locale.  For details,
  4237 see the Isar Reference manual.  Examples can be found in
  4238 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4239 
  4240 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4241 'interpret' instead.
  4242 
  4243 * New context element 'constrains' for adding type constraints to
  4244 parameters.
  4245 
  4246 * Context expressions: renaming of parameters with syntax
  4247 redeclaration.
  4248 
  4249 * Locale declaration: 'includes' disallowed.
  4250 
  4251 * Proper static binding of attribute syntax -- i.e. types / terms /
  4252 facts mentioned as arguments are always those of the locale definition
  4253 context, independently of the context of later invocations.  Moreover,
  4254 locale operations (renaming and type / term instantiation) are applied
  4255 to attribute arguments as expected.
  4256 
  4257 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4258 actual attributes; rare situations may require Attrib.attribute to
  4259 embed those attributes into Attrib.src that lack concrete syntax.
  4260 Attribute implementations need to cooperate properly with the static
  4261 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4262 Attrib.XXX_thm etc. already do the right thing without further
  4263 intervention.  Only unusual applications -- such as "where" or "of"
  4264 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4265 on the context and the facts involved -- may have to assign parsed
  4266 values to argument tokens explicitly.
  4267 
  4268 * Changed parameter management in theorem generation for long goal
  4269 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4270 theorem statement in rare situations.
  4271 
  4272 * Locale inspection command 'print_locale' omits notes elements.  Use
  4273 'print_locale!' to have them included in the output.
  4274 
  4275 
  4276 *** Provers ***
  4277 
  4278 * Provers/hypsubst.ML: improved version of the subst method, for
  4279 single-step rewriting: it now works in bound variable contexts. New is
  4280 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4281 rewrite a different subterm than the original subst method, which is
  4282 still available as 'simplesubst'.
  4283 
  4284 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4285 and quasi orders.
  4286 
  4287 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4288 reflexive-transitive closure of relations.
  4289 
  4290 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4291 limit (previously hard-coded with a value of 20) user-definable.
  4292 
  4293 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4294 is peformed already.  Object-logics merely need to finish their
  4295 initial simpset configuration as before.  INCOMPATIBILITY.
  4296 
  4297 
  4298 *** HOL ***
  4299 
  4300 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4301 
  4302   syntax (epsilon)
  4303     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4304 
  4305 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4306 and x-symbol; use option '-m epsilon' to get it actually printed.
  4307 Moreover, the mathematically important symbolic identifier \<epsilon>
  4308 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4309 
  4310 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4311 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4312 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4313 support corresponding Isar calculations.
  4314 
  4315 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4316 instead of ":".
  4317 
  4318 * theory SetInterval: changed the syntax for open intervals:
  4319 
  4320   Old       New
  4321   {..n(}    {..<n}
  4322   {)n..}    {n<..}
  4323   {m..n(}   {m..<n}
  4324   {)m..n}   {m<..n}
  4325   {)m..n(}  {m<..<n}
  4326 
  4327 The old syntax is still supported but will disappear in the next
  4328 release.  For conversion use the following Emacs search and replace
  4329 patterns (these are not perfect but work quite well):
  4330 
  4331   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4332   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4333 
  4334 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4335 equalities in commutative rings; method 'algebra' provides a generic
  4336 interface.
  4337 
  4338 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4339 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4340 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4341 be a tuple pattern.
  4342 
  4343 Some new syntax forms are available:
  4344 
  4345   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4346   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4347   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4348   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4349 
  4350 The latter form "\<Sum>x < k. e" used to be based on a separate
  4351 function "Summation", which has been discontinued.
  4352 
  4353 * theory Finite_Set: in structured induction proofs, the insert case
  4354 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4355 (insert F x)'.
  4356 
  4357 * The 'refute' command has been extended to support a much larger
  4358 fragment of HOL, including axiomatic type classes, constdefs and
  4359 typedefs, inductive datatypes and recursion.
  4360 
  4361 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4362 Requires zChaff with proof generation to be installed.  See
  4363 HOL/ex/SAT_Examples.thy for examples.
  4364 
  4365 * Datatype induction via method 'induct' now preserves the name of the
  4366 induction variable. For example, when proving P(xs::'a list) by
  4367 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4368 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4369 in unstructured proof scripts.
  4370 
  4371 * Reworked implementation of records.  Improved scalability for
  4372 records with many fields, avoiding performance problems for type
  4373 inference. Records are no longer composed of nested field types, but
  4374 of nested extension types. Therefore the record type only grows linear
  4375 in the number of extensions and not in the number of fields.  The
  4376 top-level (users) view on records is preserved.  Potential
  4377 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4378 old record representation. The type generated for a record is called
  4379 <record_name>_ext_type.
  4380 
  4381 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4382 proofs triggered by a record definition or a simproc (if
  4383 quick_and_dirty is enabled).  Definitions of large records can take
  4384 quite long.
  4385 
  4386 New simproc record_upd_simproc for simplification of multiple record
  4387 updates enabled by default.  Moreover, trivial updates are also
  4388 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4389 occasionally, since simplification is more powerful by default.
  4390 
  4391 * typedef: proper support for polymorphic sets, which contain extra
  4392 type-variables in the term.
  4393 
  4394 * Simplifier: automatically reasons about transitivity chains
  4395 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4396 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4397 old proofs break occasionally as simplification may now solve more
  4398 goals than previously.
  4399 
  4400 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4401 present.  Works for all partial orders (class "order"), in particular
  4402 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4403 just like y <= x.
  4404 
  4405 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4406 bound variable or a constant then the let is unfolded.  Otherwise
  4407 first a is simplified to b, and then f b is simplified to g. If
  4408 possible we abstract b from g arriving at "let x = b in h x",
  4409 otherwise we unfold the let and arrive at g.  The simproc can be
  4410 enabled/disabled by the reference use_let_simproc.  Potential
  4411 INCOMPATIBILITY since simplification is more powerful by default.
  4412 
  4413 * Classical reasoning: the meson method now accepts theorems as arguments.
  4414 
  4415 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4416 jobs to provide advice on the provability of subgoals.
  4417 
  4418 * Theory OrderedGroup and Ring_and_Field: various additions and
  4419 improvements to faciliate calculations involving equalities and
  4420 inequalities.
  4421 
  4422 The following theorems have been eliminated or modified
  4423 (INCOMPATIBILITY):
  4424 
  4425   abs_eq             now named abs_of_nonneg
  4426   abs_of_ge_0        now named abs_of_nonneg
  4427   abs_minus_eq       now named abs_of_nonpos
  4428   imp_abs_id         now named abs_of_nonneg
  4429   imp_abs_neg_id     now named abs_of_nonpos
  4430   mult_pos           now named mult_pos_pos
  4431   mult_pos_le        now named mult_nonneg_nonneg
  4432   mult_pos_neg_le    now named mult_nonneg_nonpos
  4433   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4434   mult_neg           now named mult_neg_neg
  4435   mult_neg_le        now named mult_nonpos_nonpos
  4436 
  4437 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4438      
  4439      zero_le_square
  4440      not_square_less_zero 
  4441 
  4442   The following lemmas have been deleted from Real/RealPow:
  4443   
  4444      realpow_zero_zero
  4445      realpow_two
  4446      realpow_less
  4447      zero_le_power
  4448      realpow_two_le
  4449      abs_realpow_two
  4450      realpow_two_abs     
  4451 
  4452 * Theory Parity: added rules for simplifying exponents.
  4453 
  4454 * Theory List:
  4455 
  4456 The following theorems have been eliminated or modified
  4457 (INCOMPATIBILITY):
  4458 
  4459   list_all_Nil       now named list_all.simps(1)
  4460   list_all_Cons      now named list_all.simps(2)
  4461   list_all_conv      now named list_all_iff
  4462   set_mem_eq         now named mem_iff
  4463 
  4464 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4465 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4466 
  4467 
  4468 *** HOL-Complex ***
  4469 
  4470 * Theory RealDef: better support for embedding natural numbers and
  4471 integers in the reals.
  4472 
  4473 The following theorems have been eliminated or modified
  4474 (INCOMPATIBILITY):
  4475 
  4476   exp_ge_add_one_self  now requires no hypotheses
  4477   real_of_int_add      reversed direction of equality (use [symmetric])
  4478   real_of_int_minus    reversed direction of equality (use [symmetric])
  4479   real_of_int_diff     reversed direction of equality (use [symmetric])
  4480   real_of_int_mult     reversed direction of equality (use [symmetric])
  4481 
  4482 * Theory RComplete: expanded support for floor and ceiling functions.
  4483 
  4484 * Theory Ln is new, with properties of the natural logarithm
  4485 
  4486 * Hyperreal: There is a new type constructor "star" for making
  4487 nonstandard types.  The old type names are now type synonyms:
  4488 
  4489   hypreal = real star
  4490   hypnat = nat star
  4491   hcomplex = complex star
  4492 
  4493 * Hyperreal: Many groups of similarly-defined constants have been
  4494 replaced by polymorphic versions (INCOMPATIBILITY):
  4495 
  4496   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4497 
  4498   starset      <-- starsetNat, starsetC
  4499   *s*          <-- *sNat*, *sc*
  4500   starset_n    <-- starsetNat_n, starsetC_n
  4501   *sn*         <-- *sNatn*, *scn*
  4502   InternalSets <-- InternalNatSets, InternalCSets
  4503 
  4504   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4505   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4506   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4507   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4508   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4509 
  4510 * Hyperreal: Many type-specific theorems have been removed in favor of
  4511 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4512 
  4513   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4514   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4515   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4516   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4517   right_minus <-- hypreal_add_minus
  4518   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4519   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4520   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4521   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4522   mult_1_right <-- hcomplex_mult_one_right
  4523   mult_zero_left <-- hcomplex_mult_zero_left
  4524   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4525   right_distrib <-- hypnat_add_mult_distrib2
  4526   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4527   right_inverse <-- hypreal_mult_inverse
  4528   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4529   order_refl <-- {hypreal,hypnat}_le_refl
  4530   order_trans <-- {hypreal,hypnat}_le_trans
  4531   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4532   order_less_le <-- {hypreal,hypnat}_less_le
  4533   linorder_linear <-- {hypreal,hypnat}_le_linear
  4534   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4535   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4536   add_nonneg_nonneg <-- hypreal_le_add_order
  4537 
  4538 * Hyperreal: Separate theorems having to do with type-specific
  4539 versions of constants have been merged into theorems that apply to the
  4540 new polymorphic constants (INCOMPATIBILITY):
  4541 
  4542   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4543   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4544   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4545   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4546   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4547   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4548   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4549   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4550   STAR_diff <-- {STAR,STARC}_diff
  4551   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4552     STARC_hcomplex_of_complex}_image_subset
  4553   starset_n_Un <-- starset{Nat,C}_n_Un
  4554   starset_n_Int <-- starset{Nat,C}_n_Int
  4555   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4556   starset_n_diff <-- starset{Nat,C}_n_diff
  4557   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4558   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4559   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4560   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4561   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4562   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4563   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4564   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4565   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4566   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4567   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4568   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4569   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4570   starfun_diff <-- starfun{C,RC,CR}_diff
  4571   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4572   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4573   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4574   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4575   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4576   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4577   starfun_Id <-- starfunC_Id
  4578   starfun_approx <-- starfun{Nat,CR}_approx
  4579   starfun_capprox <-- starfun{C,RC}_capprox
  4580   starfun_abs <-- starfunNat_rabs
  4581   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4582   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4583   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4584   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4585   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4586   starfun_add_approx <-- starfunCR_add_approx
  4587   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4588   starfun_divide <-- starfun{C,CR,RC}_divide
  4589   starfun_n <-- starfun{Nat,C}_n
  4590   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4591   starfun_n_add <-- starfun{Nat,C}_n_add
  4592   starfun_n_add_minus <-- starfunNat_n_add_minus
  4593   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4594   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4595   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4596 
  4597   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4598   star_n_minus <-- {hypreal,hcomplex}_minus
  4599   star_n_diff <-- {hypreal,hcomplex}_diff
  4600   star_n_mult <-- {hypreal,hcomplex}_mult
  4601   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4602   star_n_le <-- {hypreal,hypnat}_le
  4603   star_n_less <-- {hypreal,hypnat}_less
  4604   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4605   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4606   star_n_abs <-- hypreal_hrabs
  4607   star_n_divide <-- hcomplex_divide
  4608 
  4609   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4610   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4611   star_of_diff <-- hypreal_of_real_diff
  4612   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4613   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4614   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4615   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4616   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4617   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4618   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4619   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4620   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4621   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4622   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4623   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4624   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4625   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4626   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4627   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4628   star_of_power <-- hypreal_of_real_power
  4629   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4630 
  4631 * Hyperreal: new method "transfer" that implements the transfer
  4632 principle of nonstandard analysis. With a subgoal that mentions
  4633 nonstandard types like "'a star", the command "apply transfer"
  4634 replaces it with an equivalent one that mentions only standard types.
  4635 To be successful, all free variables must have standard types; non-
  4636 standard variables must have explicit universal quantifiers.
  4637 
  4638 * Hyperreal: A theory of Taylor series.
  4639 
  4640 
  4641 *** HOLCF ***
  4642 
  4643 * Discontinued special version of 'constdefs' (which used to support
  4644 continuous functions) in favor of the general Pure one with full
  4645 type-inference.
  4646 
  4647 * New simplification procedure for solving continuity conditions; it
  4648 is much faster on terms with many nested lambda abstractions (cubic
  4649 instead of exponential time).
  4650 
  4651 * New syntax for domain package: selector names are now optional.
  4652 Parentheses should be omitted unless argument is lazy, for example:
  4653 
  4654   domain 'a stream = cons "'a" (lazy "'a stream")
  4655 
  4656 * New command 'fixrec' for defining recursive functions with pattern
  4657 matching; defining multiple functions with mutual recursion is also
  4658 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4659 sinr, or any data constructor defined by the domain package. The given
  4660 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4661 syntax and examples.
  4662 
  4663 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4664 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4665 but the proof obligation additionally includes an admissibility
  4666 requirement. The packages generate instances of class cpo or pcpo,
  4667 with continuity and strictness theorems for Rep and Abs.
  4668 
  4669 * HOLCF: Many theorems have been renamed according to a more standard naming
  4670 scheme (INCOMPATIBILITY):
  4671 
  4672   foo_inject:  "foo$x = foo$y ==> x = y"
  4673   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4674   foo_less:    "(foo$x << foo$y) = (x << y)"
  4675   foo_strict:  "foo$UU = UU"
  4676   foo_defined: "... ==> foo$x ~= UU"
  4677   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4678 
  4679 
  4680 *** ZF ***
  4681 
  4682 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4683 including the First Isomorphism Theorem (on quotienting by the kernel
  4684 of a homomorphism).
  4685 
  4686 * ZF/Simplifier: install second copy of type solver that actually
  4687 makes use of TC rules declared to Isar proof contexts (or locales);
  4688 the old version is still required for ML proof scripts.
  4689 
  4690 
  4691 *** Cube ***
  4692 
  4693 * Converted to Isar theory format; use locales instead of axiomatic
  4694 theories.
  4695 
  4696 
  4697 *** ML ***
  4698 
  4699 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4700 for ||>, ||>>, |>>,
  4701 
  4702 * Pure/library.ML no longer defines its own option datatype, but uses
  4703 that of the SML basis, which has constructors NONE and SOME instead of
  4704 None and Some, as well as exception Option.Option instead of OPTION.
  4705 The functions the, if_none, is_some, is_none have been adapted
  4706 accordingly, while Option.map replaces apsome.
  4707 
  4708 * Pure/library.ML: the exception LIST has been given up in favour of
  4709 the standard exceptions Empty and Subscript, as well as
  4710 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4711 superceded by the standard hd and tl functions etc.
  4712 
  4713 A number of basic list functions are no longer exported to the ML
  4714 toplevel, as they are variants of predefined functions.  The following
  4715 suggests how one can translate existing code:
  4716 
  4717     rev_append xs ys = List.revAppend (xs, ys)
  4718     nth_elem (i, xs) = List.nth (xs, i)
  4719     last_elem xs = List.last xs
  4720     flat xss = List.concat xss
  4721     seq fs = List.app fs
  4722     partition P xs = List.partition P xs
  4723     mapfilter f xs = List.mapPartial f xs
  4724 
  4725 * Pure/library.ML: several combinators for linear functional
  4726 transformations, notably reverse application and composition:
  4727 
  4728   x |> f                f #> g
  4729   (x, y) |-> f          f #-> g
  4730 
  4731 * Pure/library.ML: introduced/changed precedence of infix operators:
  4732 
  4733   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4734   infix 2 ?;
  4735   infix 3 o oo ooo oooo;
  4736   infix 4 ~~ upto downto;
  4737 
  4738 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4739 infix operators.
  4740 
  4741 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4742 fold_map support linear functional transformations and nesting.  For
  4743 example:
  4744 
  4745   fold f [x1, ..., xN] y =
  4746     y |> f x1 |> ... |> f xN
  4747 
  4748   (fold o fold) f [xs1, ..., xsN] y =
  4749     y |> fold f xs1 |> ... |> fold f xsN
  4750 
  4751   fold f [x1, ..., xN] =
  4752     f x1 #> ... #> f xN
  4753 
  4754   (fold o fold) f [xs1, ..., xsN] =
  4755     fold f xs1 #> ... #> fold f xsN
  4756 
  4757 * Pure/library.ML: the following selectors on type 'a option are
  4758 available:
  4759 
  4760   the:               'a option -> 'a  (*partial*)
  4761   these:             'a option -> 'a  where 'a = 'b list
  4762   the_default: 'a -> 'a option -> 'a
  4763   the_list:          'a option -> 'a list
  4764 
  4765 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4766 basic operations for association lists, following natural argument
  4767 order; moreover the explicit equality predicate passed here avoids
  4768 potentially expensive polymorphic runtime equality checks.
  4769 The old functions may be expressed as follows:
  4770 
  4771   assoc = uncurry (AList.lookup (op =))
  4772   assocs = these oo AList.lookup (op =)
  4773   overwrite = uncurry (AList.update (op =)) o swap
  4774 
  4775 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4776 
  4777   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4778   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4779 
  4780 replacing make_keylist and keyfilter (occassionally used)
  4781 Naive rewrites:
  4782 
  4783   make_keylist = AList.make
  4784   keyfilter = AList.find (op =)
  4785 
  4786 * eq_fst and eq_snd now take explicit equality parameter, thus
  4787   avoiding eqtypes. Naive rewrites:
  4788 
  4789     eq_fst = eq_fst (op =)
  4790     eq_snd = eq_snd (op =)
  4791 
  4792 * Removed deprecated apl and apr (rarely used).
  4793   Naive rewrites:
  4794 
  4795     apl (n, op) =>>= curry op n
  4796     apr (op, m) =>>= fn n => op (n, m)
  4797 
  4798 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4799 provides a reasonably efficient light-weight implementation of sets as
  4800 lists.
  4801 
  4802 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4803 few new operations; existing lookup and update are now curried to
  4804 follow natural argument order (for use with fold etc.);
  4805 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4806 
  4807 * Pure/General: output via the Isabelle channels of
  4808 writeln/warning/error etc. is now passed through Output.output, with a
  4809 hook for arbitrary transformations depending on the print_mode
  4810 (cf. Output.add_mode -- the first active mode that provides a output
  4811 function wins).  Already formatted output may be embedded into further
  4812 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4813 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4814 accommodate easy composition of diagnostic messages etc.  Programmers
  4815 rarely need to care about Output.output or Output.raw at all, with
  4816 some notable exceptions: Output.output is required when bypassing the
  4817 standard channels (writeln etc.), or in token translations to produce
  4818 properly formatted results; Output.raw is required when capturing
  4819 already output material that will eventually be presented to the user
  4820 a second time.  For the default print mode, both Output.output and
  4821 Output.raw have no effect.
  4822 
  4823 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4824 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4825 cumulative results are displayed at the end of a batch session.
  4826 
  4827 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4828 replaced by File.platform_path and File.shell_path (with appropriate
  4829 hooks).  This provides a clean interface for unusual systems where the
  4830 internal and external process view of file names are different.
  4831 
  4832 * Pure: more efficient orders for basic syntactic entities: added
  4833 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4834 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4835 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4836 orders now -- potential INCOMPATIBILITY for code that depends on a
  4837 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4838 Library.sort_strings on result).
  4839 
  4840 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4841 fold_types traverse types/terms from left to right, observing natural
  4842 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4843 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4844 
  4845 * Pure: name spaces have been refined, with significant changes of the
  4846 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4847 to extern(_table).  The plain name entry path is superceded by a
  4848 general 'naming' context, which also includes the 'policy' to produce
  4849 a fully qualified name and external accesses of a fully qualified
  4850 name; NameSpace.extend is superceded by context dependent
  4851 Sign.declare_name.  Several theory and proof context operations modify
  4852 the naming context.  Especially note Theory.restore_naming and
  4853 ProofContext.restore_naming to get back to a sane state; note that
  4854 Theory.add_path is no longer sufficient to recover from
  4855 Theory.absolute_path in particular.
  4856 
  4857 * Pure: new flags short_names (default false) and unique_names
  4858 (default true) for controlling output of qualified names.  If
  4859 short_names is set, names are printed unqualified.  If unique_names is
  4860 reset, the name prefix is reduced to the minimum required to achieve
  4861 the original result when interning again, even if there is an overlap
  4862 with earlier declarations.
  4863 
  4864 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4865 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4866 (useful for printing error messages).  INCOMPATIBILITY.
  4867 
  4868 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4869 Theory.theory are now identified, referring to the universal
  4870 Context.theory (see Pure/context.ML).  Actual signature and theory
  4871 content is managed as theory data.  The old code and interfaces were
  4872 spread over many files and structures; the new arrangement introduces
  4873 considerable INCOMPATIBILITY to gain more clarity:
  4874 
  4875   Context -- theory management operations (name, identity, inclusion,
  4876     parents, ancestors, merge, etc.), plus generic theory data;
  4877 
  4878   Sign -- logical signature and syntax operations (declaring consts,
  4879     types, etc.), plus certify/read for common entities;
  4880 
  4881   Theory -- logical theory operations (stating axioms, definitions,
  4882     oracles), plus a copy of logical signature operations (consts,
  4883     types, etc.); also a few basic management operations (Theory.copy,
  4884     Theory.merge, etc.)
  4885 
  4886 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4887 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4888 for convenience -- they merely return the theory.
  4889 
  4890 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4891 
  4892 * Pure: the Isar proof context type is already defined early in Pure
  4893 as Context.proof (note that ProofContext.context and Proof.context are
  4894 aliases, where the latter is the preferred name).  This enables other
  4895 Isabelle components to refer to that type even before Isar is present.
  4896 
  4897 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4898 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4899 any of these kinds.  For example, Sign.intern typeK is now
  4900 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4901 Theory.hide_types.  Also note that former
  4902 Theory.hide_classes/types/consts are now
  4903 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4904 internalize their arguments!  INCOMPATIBILITY.
  4905 
  4906 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4907 datatype thmref (with constructors Name and NameSelection) instead of
  4908 plain string -- INCOMPATIBILITY;
  4909 
  4910 * Pure: cases produced by proof methods specify options, where NONE
  4911 means to remove case bindings -- INCOMPATIBILITY in
  4912 (RAW_)METHOD_CASES.
  4913 
  4914 * Pure: the following operations retrieve axioms or theorems from a
  4915 theory node or theory hierarchy, respectively:
  4916 
  4917   Theory.axioms_of: theory -> (string * term) list
  4918   Theory.all_axioms_of: theory -> (string * term) list
  4919   PureThy.thms_of: theory -> (string * thm) list
  4920   PureThy.all_thms_of: theory -> (string * thm) list
  4921 
  4922 * Pure: print_tac now outputs the goal through the trace channel.
  4923 
  4924 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4925 Reference Toplevel.debug (default false) controls detailed printing
  4926 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4927 controls execution profiling -- set to 1 for time and 2 for space
  4928 (both increase the runtime).
  4929 
  4930 * Isar session: The initial use of ROOT.ML is now always timed,
  4931 i.e. the log will show the actual process times, in contrast to the
  4932 elapsed wall-clock time that the outer shell wrapper produces.
  4933 
  4934 * Simplifier: improved handling of bound variables (nameless
  4935 representation, avoid allocating new strings).  Simprocs that invoke
  4936 the Simplifier recursively should use Simplifier.inherit_bounds to
  4937 avoid local name clashes.  Failure to do so produces warnings
  4938 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4939 for further details.
  4940 
  4941 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4942 bindings for all theorems stored within a given theory; this may help
  4943 in porting non-Isar theories to Isar ones, while keeping ML proof
  4944 scripts for the time being.
  4945 
  4946 * ML operator HTML.with_charset specifies the charset begin used for
  4947 generated HTML files.  For example:
  4948 
  4949   HTML.with_charset "utf-8" use_thy "Hebrew";
  4950   HTML.with_charset "utf-8" use_thy "Chinese";
  4951 
  4952 
  4953 *** System ***
  4954 
  4955 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4956 isabelle, isatool etc.).
  4957 
  4958 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4959 isatool doc, isatool mkdir, display_drafts etc.).
  4960 
  4961 * isatool usedir: option -f allows specification of the ML file to be
  4962 used by Isabelle; default is ROOT.ML.
  4963 
  4964 * New isatool version outputs the version identifier of the Isabelle
  4965 distribution being used.
  4966 
  4967 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4968 (containing Boolean satisfiability problems) into Isabelle/HOL
  4969 theories.
  4970 
  4971 
  4972 
  4973 New in Isabelle2004 (April 2004)
  4974 --------------------------------
  4975 
  4976 *** General ***
  4977 
  4978 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4979   Replaces linorder.ML.
  4980 
  4981 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4982   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4983   (\<a>...\<z>), are now considered normal letters, and can therefore
  4984   be used anywhere where an ASCII letter (a...zA...Z) has until
  4985   now. COMPATIBILITY: This obviously changes the parsing of some
  4986   terms, especially where a symbol has been used as a binder, say
  4987   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4988   as an identifier.  Fix it by inserting a space around former
  4989   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4990   existing theory and ML files.
  4991 
  4992 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4993 
  4994 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4995   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4996   a normal (but invisible) letter. For multiple letter subscripts repeat
  4997   \<^isub> like this: x\<^isub>1\<^isub>2.
  4998 
  4999 * Pure: There are now sub-/superscripts that can span more than one
  5000   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5001   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5002   superscript. The new control characters are not identifier parts.
  5003 
  5004 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5005   content of "..." to the latex file instead of \isacntrl... . The "..."
  5006   may consist of any printable characters excluding the end bracket >.
  5007 
  5008 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5009   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5010   declare constants "final", which prevents their being given a definition
  5011   later.  It is useful for constants whose behaviour is fixed axiomatically
  5012   rather than definitionally, such as the meta-logic connectives.
  5013 
  5014 * Pure: 'instance' now handles general arities with general sorts
  5015   (i.e. intersections of classes),
  5016 
  5017 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5018   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5019   It can be changed to alter the colors/layout of generated pages.
  5020 
  5021 
  5022 *** Isar ***
  5023 
  5024 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5025   cut_tac, subgoal_tac and thin_tac:
  5026   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5027     locales are no longer forced to write Isar proof scripts.
  5028     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5029     emulations.
  5030   - INCOMPATIBILITY: names of variables to be instantiated may no
  5031     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5032     This is consistent with the instantiation attribute "where".
  5033 
  5034 * Attributes "where" and "of":
  5035   - Now take type variables of instantiated theorem into account when reading
  5036     the instantiation string.  This fixes a bug that caused instantiated
  5037     theorems to have too special types in some circumstances.
  5038   - "where" permits explicit instantiations of type variables.
  5039 
  5040 * Calculation commands "moreover" and "also" no longer interfere with
  5041   current facts ("this"), admitting arbitrary combinations with "then"
  5042   and derived forms.
  5043 
  5044 * Locales:
  5045   - Goal statements involving the context element "includes" no longer
  5046     generate theorems with internal delta predicates (those ending on
  5047     "_axioms") in the premise.
  5048     Resolve particular premise with <locale>.intro to obtain old form.
  5049   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5050     specification and "includes" elements in goal statement.
  5051   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5052     [intro?] and [elim?] (respectively) by default.
  5053   - Experimental command for instantiation of locales in proof contexts:
  5054         instantiate <label>[<attrs>]: <loc>
  5055     Instantiates locale <loc> and adds all its theorems to the current context
  5056     taking into account their attributes.  Label and attrs are optional
  5057     modifiers, like in theorem declarations.  If present, names of
  5058     instantiated theorems are qualified with <label>, and the attributes
  5059     <attrs> are applied after any attributes these theorems might have already.
  5060       If the locale has assumptions, a chained fact of the form
  5061     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5062     are derived.  The command does not support old-style locales declared
  5063     with "locale (open)".
  5064       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5065 
  5066 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5067   (Isar) contexts.
  5068 
  5069 
  5070 *** HOL ***
  5071 
  5072 * Proof import: new image HOL4 contains the imported library from
  5073   the HOL4 system with about 2500 theorems. It is imported by
  5074   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5075   can be used like any other Isabelle image.  See
  5076   HOL/Import/HOL/README for more information.
  5077 
  5078 * Simplifier:
  5079   - Much improved handling of linear and partial orders.
  5080     Reasoners for linear and partial orders are set up for type classes
  5081     "linorder" and "order" respectively, and are added to the default simpset
  5082     as solvers.  This means that the simplifier can build transitivity chains
  5083     to solve goals from the assumptions.
  5084   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5085     of blast or auto after simplification become unnecessary because the goal
  5086     is solved by simplification already.
  5087 
  5088 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5089     all proved in axiomatic type classes for semirings, rings and fields.
  5090 
  5091 * Numerics:
  5092   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5093     now formalized using the Ring_and_Field theory mentioned above.
  5094   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5095     than before, because now they are set up once in a generic manner.
  5096   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5097     Look for the general versions in Ring_and_Field (and Power if they concern
  5098     exponentiation).
  5099 
  5100 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5101 
  5102 * Records:
  5103   - Record types are now by default printed with their type abbreviation
  5104     instead of the list of all field types. This can be configured via
  5105     the reference "print_record_type_abbr".
  5106   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5107     (not enabled by default).
  5108   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5109     EX x. x = sel r to True (not enabled by default).
  5110   - Tactic "record_split_simp_tac" to split and simplify records added.
  5111 
  5112 * 'specification' command added, allowing for definition by
  5113   specification.  There is also an 'ax_specification' command that
  5114   introduces the new constants axiomatically.
  5115 
  5116 * arith(_tac) is now able to generate counterexamples for reals as well.
  5117 
  5118 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5119 
  5120 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5121   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5122 
  5123 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5124   matrix theory to linear programming.
  5125 
  5126 * Unions and Intersections:
  5127   The latex output syntax of UN and INT has been changed
  5128   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5129   i.e. the index formulae has become a subscript.
  5130   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5131 
  5132 * Unions and Intersections over Intervals:
  5133   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5134   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5135   like in normal math, and corresponding versions for < and for intersection.
  5136 
  5137 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5138   lexicographic dictonary ordering has been added as "lexord".
  5139 
  5140 * ML: the legacy theory structures Int and List have been removed. They had
  5141   conflicted with ML Basis Library structures having the same names.
  5142 
  5143 * 'refute' command added to search for (finite) countermodels.  Only works
  5144   for a fragment of HOL.  The installation of an external SAT solver is
  5145   highly recommended.  See "HOL/Refute.thy" for details.
  5146 
  5147 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5148   formulae under an assignment of free variables to random values.
  5149   In contrast to 'refute', it can deal with inductive datatypes,
  5150   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5151   for examples.
  5152 
  5153 
  5154 *** HOLCF ***
  5155 
  5156 * Streams now come with concatenation and are part of the HOLCF image
  5157 
  5158 
  5159 
  5160 New in Isabelle2003 (May 2003)
  5161 ------------------------------
  5162 
  5163 *** General ***
  5164 
  5165 * Provers/simplifier:
  5166 
  5167   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5168     Assumptions are now subject to complete mutual simplification,
  5169     not just from left to right. The simplifier now preserves
  5170     the order of assumptions.
  5171 
  5172     Potential INCOMPATIBILITY:
  5173 
  5174     -- simp sometimes diverges where the old version did
  5175        not, e.g. invoking simp on the goal
  5176 
  5177         [| P (f x); y = x; f x = f y |] ==> Q
  5178 
  5179        now gives rise to the infinite reduction sequence
  5180 
  5181         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5182 
  5183        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5184        kind of problem.
  5185 
  5186     -- Tactics combining classical reasoner and simplification (such as auto)
  5187        are also affected by this change, because many of them rely on
  5188        simp. They may sometimes diverge as well or yield a different numbers
  5189        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5190        in case of problems. Sometimes subsequent calls to the classical
  5191        reasoner will fail because a preceeding call to the simplifier too
  5192        eagerly simplified the goal, e.g. deleted redundant premises.
  5193 
  5194   - The simplifier trace now shows the names of the applied rewrite rules
  5195 
  5196   - You can limit the number of recursive invocations of the simplifier
  5197     during conditional rewriting (where the simplifie tries to solve the
  5198     conditions before applying the rewrite rule):
  5199     ML "simp_depth_limit := n"
  5200     where n is an integer. Thus you can force termination where previously
  5201     the simplifier would diverge.
  5202 
  5203   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5204 
  5205   - No longer aborts on failed congruence proof.  Instead, the
  5206     congruence is ignored.
  5207 
  5208 * Pure: New generic framework for extracting programs from constructive
  5209   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5210   as HOL/Extraction for some case studies.
  5211 
  5212 * Pure: The main goal of the proof state is no longer shown by default, only
  5213 the subgoals. This behaviour is controlled by a new flag.
  5214    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5215 (ML: Proof.show_main_goal).
  5216 
  5217 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5218 rules whose conclusion matches subgoal 1:
  5219       PG menu: Isabelle/Isar -> Show me -> matching rules
  5220 The rules are ordered by how closely they match the subgoal.
  5221 In particular, rules that solve a subgoal outright are displayed first
  5222 (or rather last, the way they are printed).
  5223 (ML: ProofGeneral.print_intros())
  5224 
  5225 * Pure: New flag trace_unify_fail causes unification to print
  5226 diagnostic information (PG: in trace buffer) when it fails. This is
  5227 useful for figuring out why single step proofs like rule, erule or
  5228 assumption failed.
  5229 
  5230 * Pure: Locale specifications now produce predicate definitions
  5231 according to the body of text (covering assumptions modulo local
  5232 definitions); predicate "loc_axioms" covers newly introduced text,
  5233 while "loc" is cumulative wrt. all included locale expressions; the
  5234 latter view is presented only on export into the global theory
  5235 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5236 on the old view without predicates;
  5237 
  5238 * Pure: predefined locales "var" and "struct" are useful for sharing
  5239 parameters (as in CASL, for example); just specify something like
  5240 ``var x + var y + struct M'' as import;
  5241 
  5242 * Pure: improved thms_containing: proper indexing of facts instead of
  5243 raw theorems; check validity of results wrt. current name space;
  5244 include local facts of proof configuration (also covers active
  5245 locales), cover fixed variables in index; may use "_" in term
  5246 specification; an optional limit for the number of printed facts may
  5247 be given (the default is 40);
  5248 
  5249 * Pure: disallow duplicate fact bindings within new-style theory files
  5250 (batch-mode only);
  5251 
  5252 * Provers: improved induct method: assumptions introduced by case
  5253 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5254 the goal statement); "foo" still refers to all facts collectively;
  5255 
  5256 * Provers: the function blast.overloaded has been removed: all constants
  5257 are regarded as potentially overloaded, which improves robustness in exchange
  5258 for slight decrease in efficiency;
  5259 
  5260 * Provers/linorder: New generic prover for transitivity reasoning over
  5261 linear orders.  Note: this prover is not efficient!
  5262 
  5263 * Isar: preview of problems to finish 'show' now produce an error
  5264 rather than just a warning (in interactive mode);
  5265 
  5266 
  5267 *** HOL ***
  5268 
  5269 * arith(_tac)
  5270 
  5271  - Produces a counter example if it cannot prove a goal.
  5272    Note that the counter example may be spurious if the goal is not a formula
  5273    of quantifier-free linear arithmetic.
  5274    In ProofGeneral the counter example appears in the trace buffer.
  5275 
  5276  - Knows about div k and mod k where k is a numeral of type nat or int.
  5277 
  5278  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5279    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5280    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5281 
  5282 * simp's arithmetic capabilities have been enhanced a bit: it now
  5283 takes ~= in premises into account (by performing a case split);
  5284 
  5285 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5286 are distributed over a sum of terms;
  5287 
  5288 * New tactic "trans_tac" and method "trans" instantiate
  5289 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5290 "<=", "<" and "=").
  5291 
  5292 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5293 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5294 
  5295 * 'typedef' command has new option "open" to suppress the set
  5296 definition;
  5297 
  5298 * functions Min and Max on finite sets have been introduced (theory
  5299 Finite_Set);
  5300 
  5301 * attribute [symmetric] now works for relations as well; it turns
  5302 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5303 
  5304 * induct over a !!-quantified statement (say !!x1..xn):
  5305   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5306 
  5307 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5308 %x. None. Warning: empty_def now refers to the previously hidden definition
  5309 of the empty set.
  5310 
  5311 * Algebra: formalization of classical algebra.  Intended as base for
  5312 any algebraic development in Isabelle.  Currently covers group theory
  5313 (up to Sylow's theorem) and ring theory (Universal Property of
  5314 Univariate Polynomials).  Contributions welcome;
  5315 
  5316 * GroupTheory: deleted, since its material has been moved to Algebra;
  5317 
  5318 * Complex: new directory of the complex numbers with numeric constants,
  5319 nonstandard complex numbers, and some complex analysis, standard and
  5320 nonstandard (Jacques Fleuriot);
  5321 
  5322 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5323 
  5324 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5325 Fleuriot);
  5326 
  5327 * Real/HahnBanach: updated and adapted to locales;
  5328 
  5329 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5330 Gray and Kramer);
  5331 
  5332 * UNITY: added the Meier-Sanders theory of progress sets;
  5333 
  5334 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5335 as abstract algorithms, instantiated to the JVM;
  5336 
  5337 * Bali: Java source language formalization. Type system, operational
  5338 semantics, axiomatic semantics. Supported language features:
  5339 classes, interfaces, objects,virtual methods, static methods,
  5340 static/instance fields, arrays, access modifiers, definite
  5341 assignment, exceptions.
  5342 
  5343 
  5344 *** ZF ***
  5345 
  5346 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5347 universe, etc.);
  5348 
  5349 * Main ZF: virtually all theories converted to new-style format;
  5350 
  5351 
  5352 *** ML ***
  5353 
  5354 * Pure: Tactic.prove provides sane interface for internal proofs;
  5355 omits the infamous "standard" operation, so this is more appropriate
  5356 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5357 
  5358 * Pure: improved error reporting of simprocs;
  5359 
  5360 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5361 up simprocs;
  5362 
  5363 
  5364 *** Document preparation ***
  5365 
  5366 * uses \par instead of \\ for line breaks in theory text. This may
  5367 shift some page breaks in large documents. To get the old behaviour
  5368 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5369 
  5370 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5371 other packages
  5372 
  5373 * \<euro> now needs package babel/greek instead of marvosym (which
  5374 broke \Rightarrow)
  5375 
  5376 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5377 textcomp package)
  5378 
  5379 
  5380 
  5381 New in Isabelle2002 (March 2002)
  5382 --------------------------------
  5383 
  5384 *** Document preparation ***
  5385 
  5386 * greatly simplified document preparation setup, including more
  5387 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5388 instructive isatool mkdir; users should basically be able to get
  5389 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5390 users may run a separate document processing stage manually like this:
  5391 "isatool usedir -D output HOL Test && isatool document Test/output";
  5392 
  5393 * theory dependency graph may now be incorporated into documents;
  5394 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5395 with \includegraphics of LaTeX;
  5396 
  5397 * proper spacing of consecutive markup elements, especially text
  5398 blocks after section headings;
  5399 
  5400 * support bold style (for single symbols only), input syntax is like
  5401 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5402 
  5403 * \<bullet> is now output as bold \cdot by default, which looks much
  5404 better in printed text;
  5405 
  5406 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5407 note that these symbols are currently unavailable in Proof General /
  5408 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5409 
  5410 * isatool latex no longer depends on changed TEXINPUTS, instead
  5411 isatool document copies the Isabelle style files to the target
  5412 location;
  5413 
  5414 
  5415 *** Isar ***
  5416 
  5417 * Pure/Provers: improved proof by cases and induction;
  5418   - 'case' command admits impromptu naming of parameters (such as
  5419     "case (Suc n)");
  5420   - 'induct' method divinates rule instantiation from the inductive
  5421     claim; no longer requires excessive ?P bindings for proper
  5422     instantiation of cases;
  5423   - 'induct' method properly enumerates all possibilities of set/type
  5424     rules; as a consequence facts may be also passed through *type*
  5425     rules without further ado;
  5426   - 'induct' method now derives symbolic cases from the *rulified*
  5427     rule (before it used to rulify cases stemming from the internal
  5428     atomized version); this means that the context of a non-atomic
  5429     statement becomes is included in the hypothesis, avoiding the
  5430     slightly cumbersome show "PROP ?case" form;
  5431   - 'induct' may now use elim-style induction rules without chaining
  5432     facts, using ``missing'' premises from the goal state; this allows
  5433     rules stemming from inductive sets to be applied in unstructured
  5434     scripts, while still benefitting from proper handling of non-atomic
  5435     statements; NB: major inductive premises need to be put first, all
  5436     the rest of the goal is passed through the induction;
  5437   - 'induct' proper support for mutual induction involving non-atomic
  5438     rule statements (uses the new concept of simultaneous goals, see
  5439     below);
  5440   - append all possible rule selections, but only use the first
  5441     success (no backtracking);
  5442   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5443   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5444   - added 'print_induct_rules' (covered by help item in recent Proof
  5445     General versions);
  5446   - moved induct/cases attributes to Pure, methods to Provers;
  5447   - generic method setup instantiated for FOL and HOL;
  5448 
  5449 * Pure: support multiple simultaneous goal statements, for example
  5450 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5451 meta-level mechanism, this acts as if several individual goals had
  5452 been stated separately; in particular common proof methods need to be
  5453 repeated in order to cover all claims; note that a single elimination
  5454 step is *not* sufficient to establish the two conjunctions, so this
  5455 fails:
  5456 
  5457   assume "A & B" then have A and B ..   (*".." fails*)
  5458 
  5459 better use "obtain" in situations as above; alternative refer to
  5460 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5461 
  5462 * Pure: proper integration with ``locales''; unlike the original
  5463 version by Florian Kammller, Isar locales package high-level proof
  5464 contexts rather than raw logical ones (e.g. we admit to include
  5465 attributes everywhere); operations on locales include merge and
  5466 rename; support for implicit arguments (``structures''); simultaneous
  5467 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5468 some examples;
  5469 
  5470 * Pure: the following commands have been ``localized'', supporting a
  5471 target locale specification "(in name)": 'lemma', 'theorem',
  5472 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5473 stored both within the locale and at the theory level (exported and
  5474 qualified by the locale name);
  5475 
  5476 * Pure: theory goals may now be specified in ``long'' form, with
  5477 ad-hoc contexts consisting of arbitrary locale elements. for example
  5478 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5479 definitions may be given, too); the result is a meta-level rule with
  5480 the context elements being discharged in the obvious way;
  5481 
  5482 * Pure: new proof command 'using' allows to augment currently used
  5483 facts after a goal statement ('using' is syntactically analogous to
  5484 'apply', but acts on the goal's facts only); this allows chained facts
  5485 to be separated into parts given before and after a claim, as in
  5486 ``from a and b have C using d and e <proof>'';
  5487 
  5488 * Pure: renamed "antecedent" case to "rule_context";
  5489 
  5490 * Pure: new 'judgment' command records explicit information about the
  5491 object-logic embedding (used by several tools internally); no longer
  5492 use hard-wired "Trueprop";
  5493 
  5494 * Pure: added 'corollary' command;
  5495 
  5496 * Pure: fixed 'token_translation' command;
  5497 
  5498 * Pure: removed obsolete 'exported' attribute;
  5499 
  5500 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5501 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5502 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5503 
  5504 * Pure: method 'atomize' presents local goal premises as object-level
  5505 statements (atomic meta-level propositions); setup controlled via
  5506 rewrite rules declarations of 'atomize' attribute; example
  5507 application: 'induct' method with proper rule statements in improper
  5508 proof *scripts*;
  5509 
  5510 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5511 now consider the syntactic context of assumptions, giving a better
  5512 chance to get type-inference of the arguments right (this is
  5513 especially important for locales);
  5514 
  5515 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5516 mode;
  5517 
  5518 * Pure/obtain: the formal conclusion "thesis", being marked as
  5519 ``internal'', may no longer be reference directly in the text;
  5520 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5521 situations;
  5522 
  5523 * Pure: generic 'sym' attribute which declares a rule both as pure
  5524 'elim?' and for the 'symmetric' operation;
  5525 
  5526 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5527 text; the fixed correlation with particular command syntax has been
  5528 discontinued;
  5529 
  5530 * Pure: new method 'rules' is particularly well-suited for proof
  5531 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5532 but often produces more compact proof terms with less detours;
  5533 
  5534 * Pure/Provers/classical: simplified integration with pure rule
  5535 attributes and methods; the classical "intro?/elim?/dest?"
  5536 declarations coincide with the pure ones; the "rule" method no longer
  5537 includes classically swapped intros; "intro" and "elim" methods no
  5538 longer pick rules from the context; also got rid of ML declarations
  5539 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5540 INCOMPATIBILITY;
  5541 
  5542 * Provers/classical: attribute 'swapped' produces classical inversions
  5543 of introduction rules;
  5544 
  5545 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5546 rules instead of full simplifier context; 'iff' attribute handles
  5547 conditional rules;
  5548 
  5549 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5550 
  5551 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5552 "(permissive)" option to recover old behavior;
  5553 
  5554 * HOL: 'inductive' no longer features separate (collective) attributes
  5555 for 'intros' (was found too confusing);
  5556 
  5557 * HOL: properly declared induction rules less_induct and
  5558 wf_induct_rule;
  5559 
  5560 
  5561 *** HOL ***
  5562 
  5563 * HOL: moved over to sane numeral syntax; the new policy is as
  5564 follows:
  5565 
  5566   - 0 and 1 are polymorphic constants, which are defined on any
  5567   numeric type (nat, int, real etc.);
  5568 
  5569   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5570   binary representation internally;
  5571 
  5572   - type nat has special constructor Suc, and generally prefers Suc 0
  5573   over 1::nat and Suc (Suc 0) over 2::nat;
  5574 
  5575 This change may cause significant problems of INCOMPATIBILITY; here
  5576 are some hints on converting existing sources:
  5577 
  5578   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5579   entities, so expressions involving "-" (unary or binary minus) need
  5580   to be spaced properly;
  5581 
  5582   - existing occurrences of "1" may need to be constraint "1::nat" or
  5583   even replaced by Suc 0; similar for old "2";
  5584 
  5585   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5586 
  5587   - remove all special provisions on numerals in proofs;
  5588 
  5589 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5590 representation (depends on bin_arith_simps in the default context);
  5591 
  5592 * HOL: symbolic syntax for x^2 (numeral 2);
  5593 
  5594 * HOL: the class of all HOL types is now called "type" rather than
  5595 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5596 in axclass/classes, instance/arities, and (usually rare) occurrences
  5597 in typings (of consts etc.); internally the class is called
  5598 "HOL.type", ML programs should refer to HOLogic.typeS;
  5599 
  5600 * HOL/record package improvements:
  5601   - new derived operations "fields" to build a partial record section,
  5602     "extend" to promote a fixed record to a record scheme, and
  5603     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5604     declared as simp by default;
  5605   - shared operations ("more", "fields", etc.) now need to be always
  5606     qualified) --- potential INCOMPATIBILITY;
  5607   - removed "make_scheme" operations (use "make" with "extend") --
  5608     INCOMPATIBILITY;
  5609   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5610   - provides cases/induct rules for use with corresponding Isar
  5611     methods (for concrete records, record schemes, concrete more
  5612     parts, and schematic more parts -- in that order);
  5613   - internal definitions directly based on a light-weight abstract
  5614     theory of product types over typedef rather than datatype;
  5615 
  5616 * HOL: generic code generator for generating executable ML code from
  5617 specifications; specific support for HOL constructs such as inductive
  5618 datatypes and sets, as well as recursive functions; can be invoked
  5619 via 'generate_code' theory section;
  5620 
  5621 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5622 
  5623 * HOL: consolidated and renamed several theories.  In particular:
  5624         Ord.thy has been absorbed into HOL.thy
  5625         String.thy has been absorbed into List.thy
  5626 
  5627 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5628 (beware of argument permutation!);
  5629 
  5630 * HOL: linorder_less_split superseded by linorder_cases;
  5631 
  5632 * HOL/List: "nodups" renamed to "distinct";
  5633 
  5634 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5635 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5636   - Ex_def has changed, now need to use some_eq_ex
  5637 
  5638 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5639 in this (rare) case use:
  5640 
  5641   delSWrapper "split_all_tac"
  5642   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5643 
  5644 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5645 MAY FAIL;
  5646 
  5647 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5648 Isabelle's type classes, ^ on functions and relations has too general
  5649 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5650 necessary to attach explicit type constraints;
  5651 
  5652 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5653 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5654 renamed accordingly (eg "compI" -> "rel_compI").
  5655 
  5656 * HOL: syntax translations now work properly with numerals and records
  5657 expressions;
  5658 
  5659 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5660 of "lam" -- INCOMPATIBILITY;
  5661 
  5662 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5663 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5664 renamed "Product_Type.unit";
  5665 
  5666 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5667 
  5668 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5669 the "cases" method);
  5670 
  5671 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5672 Florian Kammller);
  5673 
  5674 * HOL/IMP: updated and converted to new-style theory format; several
  5675 parts turned into readable document, with proper Isar proof texts and
  5676 some explanations (by Gerwin Klein);
  5677 
  5678 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5679 
  5680 * HOL-Hyperreal is now a logic image;
  5681 
  5682 
  5683 *** HOLCF ***
  5684 
  5685 * Isar: consts/constdefs supports mixfix syntax for continuous
  5686 operations;
  5687 
  5688 * Isar: domain package adapted to new-style theory format, e.g. see
  5689 HOLCF/ex/Dnat.thy;
  5690 
  5691 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5692 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5693 lift.induct_tac, always use UU instead of Undef;
  5694 
  5695 * HOLCF/IMP: updated and converted to new-style theory;
  5696 
  5697 
  5698 *** ZF ***
  5699 
  5700 * Isar: proper integration of logic-specific tools and packages,
  5701 including theory commands '(co)inductive', '(co)datatype',
  5702 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5703 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5704 
  5705 * theory Main no longer includes AC; for the Axiom of Choice, base
  5706 your theory on Main_ZFC;
  5707 
  5708 * the integer library now covers quotients and remainders, with many
  5709 laws relating division to addition, multiplication, etc.;
  5710 
  5711 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5712 typeless version of the formalism;
  5713 
  5714 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5715 format;
  5716 
  5717 * ZF/Induct: new directory for examples of inductive definitions,
  5718 including theory Multiset for multiset orderings; converted to
  5719 new-style theory format;
  5720 
  5721 * ZF: many new theorems about lists, ordinals, etc.;
  5722 
  5723 
  5724 *** General ***
  5725 
  5726 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5727 variable proof controls level of detail: 0 = no proofs (only oracle
  5728 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5729 also ref manual for further ML interfaces;
  5730 
  5731 * Pure/axclass: removed obsolete ML interface
  5732 goal_subclass/goal_arity;
  5733 
  5734 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5735 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5736 separate tokens, so expressions involving minus need to be spaced
  5737 properly;
  5738 
  5739 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5740 rather than "infixl" or "infixr";
  5741 
  5742 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5743 sort constraint specifications in type inference; e.g. "x::_::foo"
  5744 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5745 type variable);
  5746 
  5747 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5748 control output of nested => (types); the default behavior is
  5749 "type_brackets";
  5750 
  5751 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5752 tokens into AST constants;
  5753 
  5754 * Pure/syntax: prefer later declarations of translations and print
  5755 translation functions; potential INCOMPATIBILITY: need to reverse
  5756 multiple declarations for same syntax element constant;
  5757 
  5758 * Pure/show_hyps reset by default (in accordance to existing Isar
  5759 practice);
  5760 
  5761 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5762 addSafter;
  5763 
  5764 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5765 as well;
  5766 
  5767 * system: tested support for MacOS X; should be able to get Isabelle +
  5768 Proof General to work in a plain Terminal after installing Poly/ML
  5769 (e.g. from the Isabelle distribution area) and GNU bash alone
  5770 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5771 support requires further installations, e.g. from
  5772 http://fink.sourceforge.net/);
  5773 
  5774 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5775 
  5776 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5777 of 40 MB), cf. ML_OPTIONS;
  5778 
  5779 * system: Proof General keywords specification is now part of the
  5780 Isabelle distribution (see etc/isar-keywords.el);
  5781 
  5782 * system: support for persistent Proof General sessions (refrain from
  5783 outdating all loaded theories on startup); user may create writable
  5784 logic images like this: ``isabelle -q HOL Test'';
  5785 
  5786 * system: smart selection of Isabelle process versus Isabelle
  5787 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5788 run both "isabelle" and "Isabelle" even if file names are badly
  5789 damaged (executable inspects the case of the first letter of its own
  5790 name); added separate "isabelle-process" and "isabelle-interface";
  5791 
  5792 * system: refrain from any attempt at filtering input streams; no
  5793 longer support ``8bit'' encoding of old isabelle font, instead proper
  5794 iso-latin characters may now be used; the related isatools
  5795 "symbolinput" and "nonascii" have disappeared as well;
  5796 
  5797 * system: removed old "xterm" interface (the print modes "xterm" and
  5798 "xterm_color" are still available for direct use in a suitable
  5799 terminal);
  5800 
  5801 
  5802 
  5803 New in Isabelle99-2 (February 2001)
  5804 -----------------------------------
  5805 
  5806 *** Overview of INCOMPATIBILITIES ***
  5807 
  5808 * HOL: please note that theories in the Library and elsewhere often use the
  5809 new-style (Isar) format; to refer to their theorems in an ML script you must
  5810 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5811 
  5812 * HOL: inductive package no longer splits induction rule aggressively,
  5813 but only as far as specified by the introductions given; the old
  5814 format may be recovered via ML function complete_split_rule or attribute
  5815 'split_rule (complete)';
  5816 
  5817 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5818 gfp_Tarski to gfp_unfold;
  5819 
  5820 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5821 
  5822 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5823 relation); infix "^^" has been renamed "``"; infix "``" has been
  5824 renamed "`"; "univalent" has been renamed "single_valued";
  5825 
  5826 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5827 operation;
  5828 
  5829 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5830 
  5831 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5832 
  5833 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5834 consequence, it is no longer monotonic wrt. the local goal context
  5835 (which is now passed through the inductive cases);
  5836 
  5837 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5838 \<gg> to \<ggreater>;
  5839 
  5840 
  5841 *** Document preparation ***
  5842 
  5843 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5844 available: are "it" for near math-mode best-style output, "sl" for
  5845 slanted text style, and "tt" for plain type-writer; if no
  5846 \isabellestyle command is given, output is according to slanted
  5847 type-writer);
  5848 
  5849 * support sub/super scripts (for single symbols only), input syntax is
  5850 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5851 
  5852 * some more standard symbols; see Appendix A of the system manual for
  5853 the complete list of symbols defined in isabellesym.sty;
  5854 
  5855 * improved isabelle style files; more abstract symbol implementation
  5856 (should now use \isamath{...} and \isatext{...} in custom symbol
  5857 definitions);
  5858 
  5859 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5860 state; Note that presentation of goal states does not conform to
  5861 actual human-readable proof documents.  Please do not include goal
  5862 states into document output unless you really know what you are doing!
  5863 
  5864 * proper indentation of antiquoted output with proportional LaTeX
  5865 fonts;
  5866 
  5867 * no_document ML operator temporarily disables LaTeX document
  5868 generation;
  5869 
  5870 * isatool unsymbolize tunes sources for plain ASCII communication;
  5871 
  5872 
  5873 *** Isar ***
  5874 
  5875 * Pure: Isar now suffers initial goal statements to contain unbound
  5876 schematic variables (this does not conform to actual readable proof
  5877 documents, due to unpredictable outcome and non-compositional proof
  5878 checking); users who know what they are doing may use schematic goals
  5879 for Prolog-style synthesis of proven results;
  5880 
  5881 * Pure: assumption method (an implicit finishing) now handles actual
  5882 rules as well;
  5883 
  5884 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5885 initial goal, declare "that" only as Pure intro (only for single
  5886 steps); the "that" rule assumption may now be involved in implicit
  5887 finishing, thus ".." becomes a feasible for trivial obtains;
  5888 
  5889 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5890 instance proofs may be performed by "..";
  5891 
  5892 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5893 statements as well;
  5894 
  5895 * Pure: more robust selection of calculational rules;
  5896 
  5897 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5898 rule (as well as the assumption rule);
  5899 
  5900 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5901 lemmas, using the graph browser tool;
  5902 
  5903 * Pure: predict failure of "show" in interactive mode;
  5904 
  5905 * Pure: 'thms_containing' now takes actual terms as arguments;
  5906 
  5907 * HOL: improved method 'induct' --- now handles non-atomic goals
  5908 (potential INCOMPATIBILITY); tuned error handling;
  5909 
  5910 * HOL: cases and induct rules now provide explicit hints about the
  5911 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5912 any remaining facts are inserted into the goal verbatim;
  5913 
  5914 * HOL: local contexts (aka cases) may now contain term bindings as
  5915 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5916 the result to be shown in each case;
  5917 
  5918 * HOL: added 'recdef_tc' command;
  5919 
  5920 * isatool convert assists in eliminating legacy ML scripts;
  5921 
  5922 
  5923 *** HOL ***
  5924 
  5925 * HOL/Library: a collection of generic theories to be used together
  5926 with main HOL; the theory loader path already includes this directory
  5927 by default; the following existing theories have been moved here:
  5928 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5929 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5930 
  5931 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5932 modelling and verification task performed in Isabelle/HOL +
  5933 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5934 
  5935 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5936 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5937 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5938 'domain', this makes the theory consistent with mathematical
  5939 literature;
  5940 
  5941 * HOL basics: added overloaded operations "inverse" and "divide"
  5942 (infix "/"), syntax for generic "abs" operation, generic summation
  5943 operator \<Sum>;
  5944 
  5945 * HOL/typedef: simplified package, provide more useful rules (see also
  5946 HOL/subset.thy);
  5947 
  5948 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5949 now expressed as a proper nested rule (old-style tactic scripts may
  5950 require atomize_strip_tac to cope with non-atomic premises);
  5951 
  5952 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5953 to "split_conv" (old name still available for compatibility);
  5954 
  5955 * HOL: improved concrete syntax for strings (e.g. allows translation
  5956 rules with string literals);
  5957 
  5958 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5959  and Fleuriot's mechanization of analysis, including the transcendental
  5960  functions for the reals;
  5961 
  5962 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5963 
  5964 
  5965 *** CTT ***
  5966 
  5967 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5968 "lam" is displayed as TWO lambda-symbols
  5969 
  5970 * CTT: theory Main now available, containing everything (that is, Bool
  5971 and Arith);
  5972 
  5973 
  5974 *** General ***
  5975 
  5976 * Pure: the Simplifier has been implemented properly as a derived rule
  5977 outside of the actual kernel (at last!); the overall performance
  5978 penalty in practical applications is about 50%, while reliability of
  5979 the Isabelle inference kernel has been greatly improved;
  5980 
  5981 * print modes "brackets" and "no_brackets" control output of nested =>
  5982 (types) and ==> (props); the default behaviour is "brackets";
  5983 
  5984 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5985 as assumptions as well;
  5986 
  5987 * system: support Poly/ML 4.0;
  5988 
  5989 * system: isatool install handles KDE version 1 or 2;
  5990 
  5991 
  5992 
  5993 New in Isabelle99-1 (October 2000)
  5994 ----------------------------------
  5995 
  5996 *** Overview of INCOMPATIBILITIES ***
  5997 
  5998 * HOL: simplification of natural numbers is much changed; to partly
  5999 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6000 issue the following ML commands:
  6001 
  6002   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6003   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6004 
  6005 * HOL: simplification no longer dives into case-expressions; this is
  6006 controlled by "t.weak_case_cong" for each datatype t;
  6007 
  6008 * HOL: nat_less_induct renamed to less_induct;
  6009 
  6010 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6011 fixsome to patch .thy and .ML sources automatically;
  6012 
  6013   select_equality  -> some_equality
  6014   select_eq_Ex     -> some_eq_ex
  6015   selectI2EX       -> someI2_ex
  6016   selectI2         -> someI2
  6017   selectI          -> someI
  6018   select1_equality -> some1_equality
  6019   Eps_sym_eq       -> some_sym_eq_trivial
  6020   Eps_eq           -> some_eq_trivial
  6021 
  6022 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6023 
  6024 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6025 instead);
  6026 
  6027 * HOL: the recursion equations generated by 'recdef' are now called
  6028 f.simps instead of f.rules;
  6029 
  6030 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6031 
  6032 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6033 sometimes be needed;
  6034 
  6035 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6036 
  6037 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6038 
  6039 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6040 product is now "<*>" instead of "Times"; the lexicographic product is
  6041 now "<*lex*>" instead of "**";
  6042 
  6043 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6044 of main HOL, but was unused); better use HOL's datatype package;
  6045 
  6046 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6047 the old syntax may be recovered as follows:
  6048 
  6049   syntax (symbols)
  6050     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6051       (infixl "\\<oplus>" 100)
  6052 
  6053 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6054 
  6055 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6056 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6057 internally;
  6058 
  6059 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6060 changed from A/r to A//r;
  6061 
  6062 * ZF: new treatment of arithmetic (nat & int) may break some old
  6063 proofs;
  6064 
  6065 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6066 rulify -> rule_format, elimify -> elim_format, ...);
  6067 
  6068 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6069 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6070 should have to change intro!! to intro? only); replaced "delrule" by
  6071 "rule del";
  6072 
  6073 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6074 
  6075 * Provers: strengthened force_tac by using new first_best_tac;
  6076 
  6077 * LaTeX document preparation: several changes of isabelle.sty (see
  6078 lib/texinputs);
  6079 
  6080 
  6081 *** Document preparation ***
  6082 
  6083 * formal comments (text blocks etc.) in new-style theories may now
  6084 contain antiquotations of thm/prop/term/typ/text to be presented
  6085 according to latex print mode; concrete syntax is like this:
  6086 @{term[show_types] "f(x) = a + x"};
  6087 
  6088 * isatool mkdir provides easy setup of Isabelle session directories,
  6089 including proper document sources;
  6090 
  6091 * generated LaTeX sources are now deleted after successful run
  6092 (isatool document -c); may retain a copy somewhere else via -D option
  6093 of isatool usedir;
  6094 
  6095 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6096 style files, achieving self-contained LaTeX sources and simplifying
  6097 LaTeX debugging;
  6098 
  6099 * old-style theories now produce (crude) LaTeX output as well;
  6100 
  6101 * browser info session directories are now self-contained (may be put
  6102 on WWW server seperately); improved graphs of nested sessions; removed
  6103 graph for 'all sessions';
  6104 
  6105 * several improvements in isabelle style files; \isabellestyle{it}
  6106 produces fake math mode output; \isamarkupheader is now \section by
  6107 default; see lib/texinputs/isabelle.sty etc.;
  6108 
  6109 
  6110 *** Isar ***
  6111 
  6112 * Isar/Pure: local results and corresponding term bindings are now
  6113 subject to Hindley-Milner polymorphism (similar to ML); this
  6114 accommodates incremental type-inference very nicely;
  6115 
  6116 * Isar/Pure: new derived language element 'obtain' supports
  6117 generalized existence reasoning;
  6118 
  6119 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6120 support accumulation of results, without applying any rules yet;
  6121 useful to collect intermediate results without explicit name
  6122 references, and for use with transitivity rules with more than 2
  6123 premises;
  6124 
  6125 * Isar/Pure: scalable support for case-analysis type proofs: new
  6126 'case' language element refers to local contexts symbolically, as
  6127 produced by certain proof methods; internally, case names are attached
  6128 to theorems as "tags";
  6129 
  6130 * Isar/Pure: theory command 'hide' removes declarations from
  6131 class/type/const name spaces;
  6132 
  6133 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6134 indicate potential overloading;
  6135 
  6136 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6137 
  6138 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6139 "{a,b,c}" instead of {a,b,c};
  6140 
  6141 * Isar/Pure now provides its own version of intro/elim/dest
  6142 attributes; useful for building new logics, but beware of confusion
  6143 with the version in Provers/classical;
  6144 
  6145 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6146 case name 'antecedent';
  6147 
  6148 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6149 to the current context is now done automatically);
  6150 
  6151 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6152 for definining proof methods in ML;
  6153 
  6154 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6155 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6156 most cases, one should have to change intro!! to intro? only);
  6157 replaced "delrule" by "rule del";
  6158 
  6159 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6160 'symmetric' attribute (the latter supercedes [RS sym]);
  6161 
  6162 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6163 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6164 well (including splits);
  6165 
  6166 * Isar/Provers: Simplifier and Classical methods now support all kind
  6167 of modifiers used in the past, including 'cong', 'iff', etc.
  6168 
  6169 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6170 of Simplifier and Classical reasoner);
  6171 
  6172 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6173 now support named cases; major packages (inductive, datatype, primrec,
  6174 recdef) support case names and properly name parameters;
  6175 
  6176 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6177 monotonicity conditions are extracted to be proven at end of
  6178 calculations;
  6179 
  6180 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6181 method anyway;
  6182 
  6183 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6184 split_if split_if_asm; datatype package provides theorems foo.splits =
  6185 foo.split foo.split_asm for each datatype;
  6186 
  6187 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6188 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6189 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6190 use "(cases (simplified))" method in proper proof texts);
  6191 
  6192 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6193 
  6194 * Isar: names of theorems etc. may be natural numbers as well;
  6195 
  6196 * Isar: 'pr' command: optional arguments for goals_limit and
  6197 ProofContext.prems_limit; no longer prints theory contexts, but only
  6198 proof states;
  6199 
  6200 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6201 additional print modes to be specified; e.g. "pr(latex)" will print
  6202 proof state according to the Isabelle LaTeX style;
  6203 
  6204 * Isar: improved support for emulating tactic scripts, including proof
  6205 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6206 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6207 (for HOL datatypes);
  6208 
  6209 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6210 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6211 'proof method scripts' have to be in depth-first order;
  6212 
  6213 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6214 
  6215 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6216 should instead use individual commands for printing items
  6217 (print_commands, print_methods etc.);
  6218 
  6219 * Isar: added 'nothing' --- the empty list of theorems;
  6220 
  6221 
  6222 *** HOL ***
  6223 
  6224 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6225 corresponding virtual machine and a specification of its bytecode
  6226 verifier and a lightweight bytecode verifier, including proofs of
  6227 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6228 Cornelia Pusch (see also the homepage of project Bali at
  6229 http://isabelle.in.tum.de/Bali/);
  6230 
  6231 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6232 Clemens Ballarin;
  6233 
  6234 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6235 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6236 Rasmussen;
  6237 
  6238 * HOL/Lattice: fundamental concepts of lattice theory and order