NEWS
author wenzelm
Sat Apr 16 16:15:37 2011 +0200 (2011-04-16)
changeset 42361 23f352990944
parent 42360 da8817d01e7c
child 42370 244911efd275
permissions -rw-r--r--
modernized structure Proof_Context;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) is has been
    26 discontinued.  INCOMPATIBILITY.
    27 
    28 * Various optional external tools are referenced more robustly and
    29 uniformly by explicit Isabelle settings as follows:
    30 
    31   ISABELLE_CSDP   (formerly CSDP_EXE)
    32   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    33   ISABELLE_OCAML  (formerly EXEC_OCAML)
    34   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    35   ISABELLE_YAP    (formerly EXEC_YAP)
    36 
    37 Note that automated detection from the file-system or search path has
    38 been discontinued.  INCOMPATIBILITY.
    39 
    40 * Name space: proper configuration options "long_names",
    41 "short_names", "unique_names" instead of former unsynchronized
    42 references.  Minor INCOMPATIBILITY, need to declare options in context
    43 like this:
    44 
    45   declare [[unique_names = false]]
    46 
    47 
    48 *** HOL ***
    49 
    50 * Nitpick:
    51   - Added "need" and "total_consts" options.
    52   - Reintroduced "show_skolems" option by popular demand.
    53   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    54     INCOMPATIBILITY.
    55 
    56 * Sledgehammer:
    57   - sledgehammer available_provers ~> sledgehammer supported_provers
    58     INCOMPATIBILITY.
    59   - Added "monomorphize", "monomorphize_limit", and "type_sys" options.
    60 
    61 * "try":
    62   - Added "simp:", "intro:", and "elim:" options.
    63 
    64 * Quickcheck:
    65   - Added "eval" option to evaluate terms for the found counterexample
    66     (currently only supported by the default (exhaustive) tester)
    67   - Added post-processing of terms to obtain readable counterexamples
    68     (currently only supported by the default (exhaustive) tester)
    69 
    70 * Function package: discontinued option "tailrec".
    71 INCOMPATIBILITY. Use partial_function instead.
    72 
    73 * HOL-Probability:
    74   - Caratheodory's extension lemma is now proved for ring_of_sets.
    75   - Infinite products of probability measures are now available.
    76   - Use extended reals instead of positive extended reals.
    77     INCOMPATIBILITY.
    78 
    79 *** Document preparation ***
    80 
    81 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    82 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    83 
    84 
    85 *** ML ***
    86 
    87 * Structure Proof_Context follows standard naming scheme.  Old
    88 ProofContext is still available for some time as legacy alias.
    89 
    90 * Structure Timing provides various operations for timing; supersedes
    91 former start_timing/end_timing etc.
    92 
    93 * Path.print is the official way to show file-system paths to users
    94 (including quotes etc.).
    95 
    96 * Inner syntax: identifiers in parse trees of generic categories
    97 "logic", "aprop", "idt" etc. carry position information (disguised as
    98 type constraints).  Occasional INCOMPATIBILITY with non-compliant
    99 translations that choke on unexpected type constraints.  Positions can
   100 be stripped in ML translations via Syntax.strip_positions /
   101 Syntax.strip_positions_ast, or via the syntax constant
   102 "_strip_positions" within parse trees.  As last resort, positions can
   103 be disabled via the configuration option Syntax.positions, which is
   104 called "syntax_positions" in Isar attribute syntax.
   105 
   106 * Discontinued special status of various ML structures that contribute
   107 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   108 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   109 refer directly to Ast.Constant, Lexicon.is_identifier,
   110 Syntax_Trans.mk_binder_tr etc.
   111 
   112 * Typed print translation: discontinued show_sorts argument, which is
   113 already available via context of "advanced" translation.
   114 
   115 
   116 
   117 New in Isabelle2011 (January 2011)
   118 ----------------------------------
   119 
   120 *** General ***
   121 
   122 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   123 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   124 useful tooltips and hyperlinks produced from its static analysis.  The
   125 bundled component provides an executable Isabelle tool that can be run
   126 like this:
   127 
   128   Isabelle2011/bin/isabelle jedit
   129 
   130 * Significantly improved Isabelle/Isar implementation manual.
   131 
   132 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   133 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   134 while the default heap location within that directory lacks that extra
   135 suffix.  This isolates multiple Isabelle installations from each
   136 other, avoiding problems with old settings in new versions.
   137 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   138 
   139 * Source files are always encoded as UTF-8, instead of old-fashioned
   140 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   141 the following package declarations:
   142 
   143   \usepackage[utf8]{inputenc}
   144   \usepackage{textcomp}
   145 
   146 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   147 a Unicode character is treated as a single symbol, not a sequence of
   148 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   149 contain symbols without further backslash escapes, Unicode can now be
   150 used here as well.  Recall that Symbol.explode in ML provides a
   151 consistent view on symbols, while raw explode (or String.explode)
   152 merely give a byte-oriented representation.
   153 
   154 * Theory loader: source files are primarily located via the master
   155 directory of each theory node (where the .thy file itself resides).
   156 The global load path is still partially available as legacy feature.
   157 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   158 explicit paths, relatively to the theory.
   159 
   160 * Special treatment of ML file names has been discontinued.
   161 Historically, optional extensions .ML or .sml were added on demand --
   162 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   163 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   164 
   165 * Various options that affect pretty printing etc. are now properly
   166 handled within the context via configuration options, instead of
   167 unsynchronized references or print modes.  There are both ML Config.T
   168 entities and Isar declaration attributes to access these.
   169 
   170   ML (Config.T)                 Isar (attribute)
   171 
   172   eta_contract                  eta_contract
   173   show_brackets                 show_brackets
   174   show_sorts                    show_sorts
   175   show_types                    show_types
   176   show_question_marks           show_question_marks
   177   show_consts                   show_consts
   178   show_abbrevs                  show_abbrevs
   179 
   180   Syntax.ast_trace              syntax_ast_trace
   181   Syntax.ast_stat               syntax_ast_stat
   182   Syntax.ambiguity_level        syntax_ambiguity_level
   183 
   184   Goal_Display.goals_limit      goals_limit
   185   Goal_Display.show_main_goal   show_main_goal
   186 
   187   Method.rule_trace             rule_trace
   188 
   189   Thy_Output.display            thy_output_display
   190   Thy_Output.quotes             thy_output_quotes
   191   Thy_Output.indent             thy_output_indent
   192   Thy_Output.source             thy_output_source
   193   Thy_Output.break              thy_output_break
   194 
   195 Note that corresponding "..._default" references in ML may only be
   196 changed globally at the ROOT session setup, but *not* within a theory.
   197 The option "show_abbrevs" supersedes the former print mode
   198 "no_abbrevs" with inverted meaning.
   199 
   200 * More systematic naming of some configuration options.
   201 INCOMPATIBILITY.
   202 
   203   trace_simp  ~>  simp_trace
   204   debug_simp  ~>  simp_debug
   205 
   206 * Support for real valued configuration options, using simplistic
   207 floating-point notation that coincides with the inner syntax for
   208 float_token.
   209 
   210 * Support for real valued preferences (with approximative PGIP type):
   211 front-ends need to accept "pgint" values in float notation.
   212 INCOMPATIBILITY.
   213 
   214 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   215 DejaVu Sans.
   216 
   217 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   218 
   219 
   220 *** Pure ***
   221 
   222 * Command 'type_synonym' (with single argument) replaces somewhat
   223 outdated 'types', which is still available as legacy feature for some
   224 time.
   225 
   226 * Command 'nonterminal' (with 'and' separated list of arguments)
   227 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   228 
   229 * Command 'notepad' replaces former 'example_proof' for
   230 experimentation in Isar without any result.  INCOMPATIBILITY.
   231 
   232 * Locale interpretation commands 'interpret' and 'sublocale' accept
   233 lists of equations to map definitions in a locale to appropriate
   234 entities in the context of the interpretation.  The 'interpretation'
   235 command already provided this functionality.
   236 
   237 * Diagnostic command 'print_dependencies' prints the locale instances
   238 that would be activated if the specified expression was interpreted in
   239 the current context.  Variant "print_dependencies!" assumes a context
   240 without interpretations.
   241 
   242 * Diagnostic command 'print_interps' prints interpretations in proofs
   243 in addition to interpretations in theories.
   244 
   245 * Discontinued obsolete 'global' and 'local' commands to manipulate
   246 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   247 Sign.root_path and Sign.local_path may be applied directly where this
   248 feature is still required for historical reasons.
   249 
   250 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   251 'definition' instead.
   252 
   253 * The "prems" fact, which refers to the accidental collection of
   254 foundational premises in the context, is now explicitly marked as
   255 legacy feature and will be discontinued soon.  Consider using "assms"
   256 of the head statement or reference facts by explicit names.
   257 
   258 * Document antiquotations @{class} and @{type} print classes and type
   259 constructors.
   260 
   261 * Document antiquotation @{file} checks file/directory entries within
   262 the local file system.
   263 
   264 
   265 *** HOL ***
   266 
   267 * Coercive subtyping: functions can be declared as coercions and type
   268 inference will add them as necessary upon input of a term.  Theory
   269 Complex_Main declares real :: nat => real and real :: int => real as
   270 coercions. A coercion function f is declared like this:
   271 
   272   declare [[coercion f]]
   273 
   274 To lift coercions through type constructors (e.g. from nat => real to
   275 nat list => real list), map functions can be declared, e.g.
   276 
   277   declare [[coercion_map map]]
   278 
   279 Currently coercion inference is activated only in theories including
   280 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   281 the configuration option "coercion_enabled", e.g. it can be enabled in
   282 other theories like this:
   283 
   284   declare [[coercion_enabled]]
   285 
   286 * Command 'partial_function' provides basic support for recursive
   287 function definitions over complete partial orders.  Concrete instances
   288 are provided for i) the option type, ii) tail recursion on arbitrary
   289 types, and iii) the heap monad of Imperative_HOL.  See
   290 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   291 for examples.
   292 
   293 * Function package: f.psimps rules are no longer implicitly declared
   294 as [simp].  INCOMPATIBILITY.
   295 
   296 * Datatype package: theorems generated for executable equality (class
   297 "eq") carry proper names and are treated as default code equations.
   298 
   299 * Inductive package: now offers command 'inductive_simps' to
   300 automatically derive instantiated and simplified equations for
   301 inductive predicates, similar to 'inductive_cases'.
   302 
   303 * Command 'enriched_type' allows to register properties of the
   304 functorial structure of types.
   305 
   306 * Improved infrastructure for term evaluation using code generator
   307 techniques, in particular static evaluation conversions.
   308 
   309 * Code generator: Scala (2.8 or higher) has been added to the target
   310 languages.
   311 
   312 * Code generator: globbing constant expressions "*" and "Theory.*"
   313 have been replaced by the more idiomatic "_" and "Theory._".
   314 INCOMPATIBILITY.
   315 
   316 * Code generator: export_code without explicit file declaration prints
   317 to standard output.  INCOMPATIBILITY.
   318 
   319 * Code generator: do not print function definitions for case
   320 combinators any longer.
   321 
   322 * Code generator: simplification with rules determined with
   323 src/Tools/Code/code_simp.ML and method "code_simp".
   324 
   325 * Code generator for records: more idiomatic representation of record
   326 types.  Warning: records are not covered by ancient SML code
   327 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   328 rep_datatype declaration helps to succeed then:
   329 
   330   record 'a foo = ...
   331   ...
   332   rep_datatype foo_ext ...
   333 
   334 * Records: logical foundation type for records does not carry a
   335 '_type' suffix any longer (obsolete due to authentic syntax).
   336 INCOMPATIBILITY.
   337 
   338 * Quickcheck now by default uses exhaustive testing instead of random
   339 testing.  Random testing can be invoked by "quickcheck [random]",
   340 exhaustive testing by "quickcheck [exhaustive]".
   341 
   342 * Quickcheck instantiates polymorphic types with small finite
   343 datatypes by default. This enables a simple execution mechanism to
   344 handle quantifiers and function equality over the finite datatypes.
   345 
   346 * Quickcheck random generator has been renamed from "code" to
   347 "random".  INCOMPATIBILITY.
   348 
   349 * Quickcheck now has a configurable time limit which is set to 30
   350 seconds by default. This can be changed by adding [timeout = n] to the
   351 quickcheck command. The time limit for Auto Quickcheck is still set
   352 independently.
   353 
   354 * Quickcheck in locales considers interpretations of that locale for
   355 counter example search.
   356 
   357 * Sledgehammer:
   358   - Added "smt" and "remote_smt" provers based on the "smt" proof
   359     method. See the Sledgehammer manual for details ("isabelle doc
   360     sledgehammer").
   361   - Renamed commands:
   362     sledgehammer atp_info ~> sledgehammer running_provers
   363     sledgehammer atp_kill ~> sledgehammer kill_provers
   364     sledgehammer available_atps ~> sledgehammer available_provers
   365     INCOMPATIBILITY.
   366   - Renamed options:
   367     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   368     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   369     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   370     (and "ms" and "min" are no longer supported)
   371     INCOMPATIBILITY.
   372 
   373 * Nitpick:
   374   - Renamed options:
   375     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   376     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   377     INCOMPATIBILITY.
   378   - Added support for partial quotient types.
   379   - Added local versions of the "Nitpick.register_xxx" functions.
   380   - Added "whack" option.
   381   - Allow registration of quotient types as codatatypes.
   382   - Improved "merge_type_vars" option to merge more types.
   383   - Removed unsound "fast_descrs" option.
   384   - Added custom symmetry breaking for datatypes, making it possible to reach
   385     higher cardinalities.
   386   - Prevent the expansion of too large definitions.
   387 
   388 * Proof methods "metis" and "meson" now have configuration options
   389 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   390 to diagnose these tools. E.g.
   391 
   392     using [[metis_trace = true]]
   393 
   394 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   395 manually as command 'solve_direct'.
   396 
   397 * The default SMT solver Z3 must be enabled explicitly (due to
   398 licensing issues) by setting the environment variable
   399 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   400 commercial applications, the SMT solver CVC3 is provided as fall-back;
   401 changing the SMT solver is done via the configuration option
   402 "smt_solver".
   403 
   404 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   405 i.e. "remote_cvc3" and "remote_z3".
   406 
   407 * Added basic SMT support for datatypes, records, and typedefs using
   408 the oracle mode (no proofs).  Direct support of pairs has been dropped
   409 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   410 support for a similar behavior).  Minor INCOMPATIBILITY.
   411 
   412 * Changed SMT configuration options:
   413   - Renamed:
   414     z3_proofs ~> smt_oracle (with inverted meaning)
   415     z3_trace_assms ~> smt_trace_used_facts
   416     INCOMPATIBILITY.
   417   - Added:
   418     smt_verbose
   419     smt_random_seed
   420     smt_datatypes
   421     smt_infer_triggers
   422     smt_monomorph_limit
   423     cvc3_options
   424     remote_cvc3_options
   425     remote_z3_options
   426     yices_options
   427 
   428 * Boogie output files (.b2i files) need to be declared in the theory
   429 header.
   430 
   431 * Simplification procedure "list_to_set_comprehension" rewrites list
   432 comprehensions applied to List.set to set comprehensions.  Occasional
   433 INCOMPATIBILITY, may be deactivated like this:
   434 
   435   declare [[simproc del: list_to_set_comprehension]]
   436 
   437 * Removed old version of primrec package.  INCOMPATIBILITY.
   438 
   439 * Removed simplifier congruence rule of "prod_case", as has for long
   440 been the case with "split".  INCOMPATIBILITY.
   441 
   442 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   443 
   444 * Removed [split_format ... and ... and ...] version of
   445 [split_format].  Potential INCOMPATIBILITY.
   446 
   447 * Predicate "sorted" now defined inductively, with nice induction
   448 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   449 
   450 * Constant "contents" renamed to "the_elem", to free the generic name
   451 contents for other uses.  INCOMPATIBILITY.
   452 
   453 * Renamed class eq and constant eq (for code generation) to class
   454 equal and constant equal, plus renaming of related facts and various
   455 tuning.  INCOMPATIBILITY.
   456 
   457 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   458 
   459 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   460 INCOMPATIBILITY.
   461 
   462 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   463 avoid confusion with finite sets.  INCOMPATIBILITY.
   464 
   465 * Abandoned locales equiv, congruent and congruent2 for equivalence
   466 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   467 for congruent(2)).
   468 
   469 * Some previously unqualified names have been qualified:
   470 
   471   types
   472     bool ~> HOL.bool
   473     nat ~> Nat.nat
   474 
   475   constants
   476     Trueprop ~> HOL.Trueprop
   477     True ~> HOL.True
   478     False ~> HOL.False
   479     op & ~> HOL.conj
   480     op | ~> HOL.disj
   481     op --> ~> HOL.implies
   482     op = ~> HOL.eq
   483     Not ~> HOL.Not
   484     The ~> HOL.The
   485     All ~> HOL.All
   486     Ex ~> HOL.Ex
   487     Ex1 ~> HOL.Ex1
   488     Let ~> HOL.Let
   489     If ~> HOL.If
   490     Ball ~> Set.Ball
   491     Bex ~> Set.Bex
   492     Suc ~> Nat.Suc
   493     Pair ~> Product_Type.Pair
   494     fst ~> Product_Type.fst
   495     snd ~> Product_Type.snd
   496     curry ~> Product_Type.curry
   497     op : ~> Set.member
   498     Collect ~> Set.Collect
   499 
   500 INCOMPATIBILITY.
   501 
   502 * More canonical naming convention for some fundamental definitions:
   503 
   504     bot_bool_eq ~> bot_bool_def
   505     top_bool_eq ~> top_bool_def
   506     inf_bool_eq ~> inf_bool_def
   507     sup_bool_eq ~> sup_bool_def
   508     bot_fun_eq  ~> bot_fun_def
   509     top_fun_eq  ~> top_fun_def
   510     inf_fun_eq  ~> inf_fun_def
   511     sup_fun_eq  ~> sup_fun_def
   512 
   513 INCOMPATIBILITY.
   514 
   515 * More stylized fact names:
   516 
   517   expand_fun_eq ~> fun_eq_iff
   518   expand_set_eq ~> set_eq_iff
   519   set_ext       ~> set_eqI
   520   nat_number    ~> eval_nat_numeral
   521 
   522 INCOMPATIBILITY.
   523 
   524 * Refactoring of code-generation specific operations in theory List:
   525 
   526   constants
   527     null ~> List.null
   528 
   529   facts
   530     mem_iff ~> member_def
   531     null_empty ~> null_def
   532 
   533 INCOMPATIBILITY.  Note that these were not supposed to be used
   534 regularly unless for striking reasons; their main purpose was code
   535 generation.
   536 
   537 Various operations from the Haskell prelude are used for generating
   538 Haskell code.
   539 
   540 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   541 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   542 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   543 
   544 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   545 "*" and "+" respectively.  INCOMPATIBILITY.
   546 
   547 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   548 "Sum_Type.Plus" instead.
   549 
   550 * Constant "split" has been merged with constant "prod_case"; names of
   551 ML functions, facts etc. involving split have been retained so far,
   552 though.  INCOMPATIBILITY.
   553 
   554 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   555 instead.  INCOMPATIBILITY.
   556 
   557 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   558 INCOMPATIBILITY.
   559 
   560 * Former theory Library/Enum is now part of the HOL-Main image.
   561 INCOMPATIBILITY: all constants of the Enum theory now have to be
   562 referred to by its qualified name.
   563 
   564   enum    ~>  Enum.enum
   565   nlists  ~>  Enum.nlists
   566   product ~>  Enum.product
   567 
   568 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   569 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   570 INCOMPATIBILITY.
   571 
   572 * Theory Library/SetsAndFunctions has been split into
   573 Library/Function_Algebras and Library/Set_Algebras; canonical names
   574 for instance definitions for functions; various improvements.
   575 INCOMPATIBILITY.
   576 
   577 * Theory Library/Multiset provides stable quicksort implementation of
   578 sort_key.
   579 
   580 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   581 INCOMPATIBILITY.
   582 
   583 * Session Multivariate_Analysis: introduced a type class for euclidean
   584 space.  Most theorems are now stated in terms of euclidean spaces
   585 instead of finite cartesian products.
   586 
   587   types
   588     real ^ 'n ~>  'a::real_vector
   589               ~>  'a::euclidean_space
   590               ~>  'a::ordered_euclidean_space
   591         (depends on your needs)
   592 
   593   constants
   594      _ $ _        ~> _ $$ _
   595      \<chi> x. _  ~> \<chi>\<chi> x. _
   596      CARD('n)     ~> DIM('a)
   597 
   598 Also note that the indices are now natural numbers and not from some
   599 finite type. Finite cartesian products of euclidean spaces, products
   600 of euclidean spaces the real and complex numbers are instantiated to
   601 be euclidean_spaces.  INCOMPATIBILITY.
   602 
   603 * Session Probability: introduced pextreal as positive extended real
   604 numbers.  Use pextreal as value for measures.  Introduce the
   605 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   606 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   607 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   608 
   609 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   610 INCOMPATIBILITY.
   611 
   612 * Session SPARK (with image HOL-SPARK) provides commands to load and
   613 prove verification conditions generated by the SPARK Ada program
   614 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   615 
   616 
   617 *** HOL-Algebra ***
   618 
   619 * Theorems for additive ring operations (locale abelian_monoid and
   620 descendants) are generated by interpretation from their multiplicative
   621 counterparts.  Names (in particular theorem names) have the mandatory
   622 qualifier 'add'.  Previous theorem names are redeclared for
   623 compatibility.
   624 
   625 * Structure "int_ring" is now an abbreviation (previously a
   626 definition).  This fits more natural with advanced interpretations.
   627 
   628 
   629 *** HOLCF ***
   630 
   631 * The domain package now runs in definitional mode by default: The
   632 former command 'new_domain' is now called 'domain'.  To use the domain
   633 package in its original axiomatic mode, use 'domain (unsafe)'.
   634 INCOMPATIBILITY.
   635 
   636 * The new class "domain" is now the default sort.  Class "predomain"
   637 is an unpointed version of "domain". Theories can be updated by
   638 replacing sort annotations as shown below.  INCOMPATIBILITY.
   639 
   640   'a::type ~> 'a::countable
   641   'a::cpo  ~> 'a::predomain
   642   'a::pcpo ~> 'a::domain
   643 
   644 * The old type class "rep" has been superseded by class "domain".
   645 Accordingly, users of the definitional package must remove any
   646 "default_sort rep" declarations.  INCOMPATIBILITY.
   647 
   648 * The domain package (definitional mode) now supports unpointed
   649 predomain argument types, as long as they are marked 'lazy'. (Strict
   650 arguments must be in class "domain".) For example, the following
   651 domain definition now works:
   652 
   653   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   654 
   655 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   656 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   657 'a option, and 'a list.  Additionally, it configures fixrec and the
   658 domain package to work with these types.  For example:
   659 
   660   fixrec isInl :: "('a + 'b) u -> tr"
   661     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   662 
   663   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   664 
   665 * The "(permissive)" option of fixrec has been replaced with a
   666 per-equation "(unchecked)" option. See
   667 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   668 
   669 * The "bifinite" class no longer fixes a constant "approx"; the class
   670 now just asserts that such a function exists.  INCOMPATIBILITY.
   671 
   672 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   673 defines an embedding of type 'a defl into udom by default; instances
   674 of "bifinite" and "domain" classes are available in
   675 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   676 
   677 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   678 
   679 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   680 
   681 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   682 
   683 * The function "cprod_map" has been renamed to "prod_map".
   684 INCOMPATIBILITY.
   685 
   686 * The monadic bind operator on each powerdomain has new binder syntax
   687 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   688 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   689 
   690 * The infix syntax for binary union on each powerdomain has changed
   691 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   692 syntax.  INCOMPATIBILITY.
   693 
   694 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   695 still supported as an input translation.
   696 
   697 * Renamed some theorems (the original names are also still available).
   698 
   699   expand_fun_below   ~> fun_below_iff
   700   below_fun_ext      ~> fun_belowI
   701   expand_cfun_eq     ~> cfun_eq_iff
   702   ext_cfun           ~> cfun_eqI
   703   expand_cfun_below  ~> cfun_below_iff
   704   below_cfun_ext     ~> cfun_belowI
   705   cont2cont_Rep_CFun ~> cont2cont_APP
   706 
   707 * The Abs and Rep functions for various types have changed names.
   708 Related theorem names have also changed to match. INCOMPATIBILITY.
   709 
   710   Rep_CFun  ~> Rep_cfun
   711   Abs_CFun  ~> Abs_cfun
   712   Rep_Sprod ~> Rep_sprod
   713   Abs_Sprod ~> Abs_sprod
   714   Rep_Ssum  ~> Rep_ssum
   715   Abs_Ssum  ~> Abs_ssum
   716 
   717 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   718 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   719 
   720 * Various changes to bisimulation/coinduction with domain package:
   721 
   722   - Definitions of "bisim" constants no longer mention definedness.
   723   - With mutual recursion, "bisim" predicate is now curried.
   724   - With mutual recursion, each type gets a separate coind theorem.
   725   - Variable names in bisim_def and coinduct rules have changed.
   726 
   727 INCOMPATIBILITY.
   728 
   729 * Case combinators generated by the domain package for type "foo" are
   730 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   731 
   732 * Several theorems have been renamed to more accurately reflect the
   733 names of constants and types involved.  INCOMPATIBILITY.
   734 
   735   thelub_const    ~> lub_const
   736   lub_const       ~> is_lub_const
   737   thelubI         ~> lub_eqI
   738   is_lub_lub      ~> is_lubD2
   739   lubI            ~> is_lub_lub
   740   unique_lub      ~> is_lub_unique
   741   is_ub_lub       ~> is_lub_rangeD1
   742   lub_bin_chain   ~> is_lub_bin_chain
   743   lub_fun         ~> is_lub_fun
   744   thelub_fun      ~> lub_fun
   745   thelub_cfun     ~> lub_cfun
   746   thelub_Pair     ~> lub_Pair
   747   lub_cprod       ~> is_lub_prod
   748   thelub_cprod    ~> lub_prod
   749   minimal_cprod   ~> minimal_prod
   750   inst_cprod_pcpo ~> inst_prod_pcpo
   751   UU_I            ~> bottomI
   752   compact_UU      ~> compact_bottom
   753   deflation_UU    ~> deflation_bottom
   754   finite_deflation_UU ~> finite_deflation_bottom
   755 
   756 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   757 
   758   sq_ord_less_eq_trans ~> below_eq_trans
   759   sq_ord_eq_less_trans ~> eq_below_trans
   760   refl_less            ~> below_refl
   761   trans_less           ~> below_trans
   762   antisym_less         ~> below_antisym
   763   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   764   box_less             ~> box_below
   765   rev_trans_less       ~> rev_below_trans
   766   not_less2not_eq      ~> not_below2not_eq
   767   less_UU_iff          ~> below_UU_iff
   768   flat_less_iff        ~> flat_below_iff
   769   adm_less             ~> adm_below
   770   adm_not_less         ~> adm_not_below
   771   adm_compact_not_less ~> adm_compact_not_below
   772   less_fun_def         ~> below_fun_def
   773   expand_fun_less      ~> fun_below_iff
   774   less_fun_ext         ~> fun_belowI
   775   less_discr_def       ~> below_discr_def
   776   discr_less_eq        ~> discr_below_eq
   777   less_unit_def        ~> below_unit_def
   778   less_cprod_def       ~> below_prod_def
   779   prod_lessI           ~> prod_belowI
   780   Pair_less_iff        ~> Pair_below_iff
   781   fst_less_iff         ~> fst_below_iff
   782   snd_less_iff         ~> snd_below_iff
   783   expand_cfun_less     ~> cfun_below_iff
   784   less_cfun_ext        ~> cfun_belowI
   785   injection_less       ~> injection_below
   786   less_up_def          ~> below_up_def
   787   not_Iup_less         ~> not_Iup_below
   788   Iup_less             ~> Iup_below
   789   up_less              ~> up_below
   790   Def_inject_less_eq   ~> Def_below_Def
   791   Def_less_is_eq       ~> Def_below_iff
   792   spair_less_iff       ~> spair_below_iff
   793   less_sprod           ~> below_sprod
   794   spair_less           ~> spair_below
   795   sfst_less_iff        ~> sfst_below_iff
   796   ssnd_less_iff        ~> ssnd_below_iff
   797   fix_least_less       ~> fix_least_below
   798   dist_less_one        ~> dist_below_one
   799   less_ONE             ~> below_ONE
   800   ONE_less_iff         ~> ONE_below_iff
   801   less_sinlD           ~> below_sinlD
   802   less_sinrD           ~> below_sinrD
   803 
   804 
   805 *** FOL and ZF ***
   806 
   807 * All constant names are now qualified internally and use proper
   808 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   809 
   810 
   811 *** ML ***
   812 
   813 * Antiquotation @{assert} inlines a function bool -> unit that raises
   814 Fail if the argument is false.  Due to inlining the source position of
   815 failed assertions is included in the error output.
   816 
   817 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   818 text is in practice always evaluated with a stable theory checkpoint.
   819 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   820 
   821 * Antiquotation @{theory A} refers to theory A from the ancestry of
   822 the current context, not any accidental theory loader state as before.
   823 Potential INCOMPATIBILITY, subtle change in semantics.
   824 
   825 * Syntax.pretty_priority (default 0) configures the required priority
   826 of pretty-printed output and thus affects insertion of parentheses.
   827 
   828 * Syntax.default_root (default "any") configures the inner syntax
   829 category (nonterminal symbol) for parsing of terms.
   830 
   831 * Former exception Library.UnequalLengths now coincides with
   832 ListPair.UnequalLengths.
   833 
   834 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   835 main functionality is provided by structure Simplifier.
   836 
   837 * Renamed raw "explode" function to "raw_explode" to emphasize its
   838 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   839 almost all situations.
   840 
   841 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   842 See implementation manual for further details on exceptions in
   843 Isabelle/ML.
   844 
   845 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   846 meaning.
   847 
   848 * Renamed structure PureThy to Pure_Thy and moved most of its
   849 operations to structure Global_Theory, to emphasize that this is
   850 rarely-used global-only stuff.
   851 
   852 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   853 instead (or tracing for high-volume output).
   854 
   855 * Configuration option show_question_marks only affects regular pretty
   856 printing of types and terms, not raw Term.string_of_vname.
   857 
   858 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   859 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   860 @{thms} for most purposes.
   861 
   862 * ML structure Unsynchronized is never opened, not even in Isar
   863 interaction mode as before.  Old Unsynchronized.set etc. have been
   864 discontinued -- use plain := instead.  This should be *rare* anyway,
   865 since modern tools always work via official context data, notably
   866 configuration options.
   867 
   868 * Parallel and asynchronous execution requires special care concerning
   869 interrupts.  Structure Exn provides some convenience functions that
   870 avoid working directly with raw Interrupt.  User code must not absorb
   871 interrupts -- intermediate handling (for cleanup etc.) needs to be
   872 followed by re-raising of the original exception.  Another common
   873 source of mistakes are "handle _" patterns, which make the meaning of
   874 the program subject to physical effects of the environment.
   875 
   876 
   877 
   878 New in Isabelle2009-2 (June 2010)
   879 ---------------------------------
   880 
   881 *** General ***
   882 
   883 * Authentic syntax for *all* logical entities (type classes, type
   884 constructors, term constants): provides simple and robust
   885 correspondence between formal entities and concrete syntax.  Within
   886 the parse tree / AST representations, "constants" are decorated by
   887 their category (class, type, const) and spelled out explicitly with
   888 their full internal name.
   889 
   890 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   891 and translations (translation rules and translation functions in ML).
   892 Some hints on upgrading:
   893 
   894   - Many existing uses of 'syntax' and 'translations' can be replaced
   895     by more modern 'type_notation', 'notation' and 'abbreviation',
   896     which are independent of this issue.
   897 
   898   - 'translations' require markup within the AST; the term syntax
   899     provides the following special forms:
   900 
   901       CONST c   -- produces syntax version of constant c from context
   902       XCONST c  -- literally c, checked as constant from context
   903       c         -- literally c, if declared by 'syntax'
   904 
   905     Plain identifiers are treated as AST variables -- occasionally the
   906     system indicates accidental variables via the error "rhs contains
   907     extra variables".
   908 
   909     Type classes and type constructors are marked according to their
   910     concrete syntax.  Some old translations rules need to be written
   911     for the "type" category, using type constructor application
   912     instead of pseudo-term application of the default category
   913     "logic".
   914 
   915   - 'parse_translation' etc. in ML may use the following
   916     antiquotations:
   917 
   918       @{class_syntax c}   -- type class c within parse tree / AST
   919       @{term_syntax c}    -- type constructor c within parse tree / AST
   920       @{const_syntax c}   -- ML version of "CONST c" above
   921       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   922 
   923   - Literal types within 'typed_print_translations', i.e. those *not*
   924     represented as pseudo-terms are represented verbatim.  Use @{class
   925     c} or @{type_name c} here instead of the above syntax
   926     antiquotations.
   927 
   928 Note that old non-authentic syntax was based on unqualified base
   929 names, so all of the above "constant" names would coincide.  Recall
   930 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   931 diagnose syntax problems.
   932 
   933 * Type constructors admit general mixfix syntax, not just infix.
   934 
   935 * Concrete syntax may be attached to local entities without a proof
   936 body, too.  This works via regular mixfix annotations for 'fix',
   937 'def', 'obtain' etc. or via the explicit 'write' command, which is
   938 similar to the 'notation' command in theory specifications.
   939 
   940 * Discontinued unnamed infix syntax (legacy feature for many years) --
   941 need to specify constant name and syntax separately.  Internal ML
   942 datatype constructors have been renamed from InfixName to Infix etc.
   943 Minor INCOMPATIBILITY.
   944 
   945 * Schematic theorem statements need to be explicitly markup as such,
   946 via commands 'schematic_lemma', 'schematic_theorem',
   947 'schematic_corollary'.  Thus the relevance of the proof is made
   948 syntactically clear, which impacts performance in a parallel or
   949 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   950 
   951 * Use of cumulative prems via "!" in some proof methods has been
   952 discontinued (old legacy feature).
   953 
   954 * References 'trace_simp' and 'debug_simp' have been replaced by
   955 configuration options stored in the context. Enabling tracing (the
   956 case of debugging is similar) in proofs works via
   957 
   958   using [[trace_simp = true]]
   959 
   960 Tracing is then active for all invocations of the simplifier in
   961 subsequent goal refinement steps. Tracing may also still be enabled or
   962 disabled via the ProofGeneral settings menu.
   963 
   964 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   965 'hide_fact' replace the former 'hide' KIND command.  Minor
   966 INCOMPATIBILITY.
   967 
   968 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   969 more efficient than combinations with -q1 or -q2.
   970 
   971 
   972 *** Pure ***
   973 
   974 * Proofterms record type-class reasoning explicitly, using the
   975 "unconstrain" operation internally.  This eliminates all sort
   976 constraints from a theorem and proof, introducing explicit
   977 OFCLASS-premises.  On the proof term level, this operation is
   978 automatically applied at theorem boundaries, such that closed proofs
   979 are always free of sort constraints.  INCOMPATIBILITY for tools that
   980 inspect proof terms.
   981 
   982 * Local theory specifications may depend on extra type variables that
   983 are not present in the result type -- arguments TYPE('a) :: 'a itself
   984 are added internally.  For example:
   985 
   986   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   987 
   988 * Predicates of locales introduced by classes carry a mandatory
   989 "class" prefix.  INCOMPATIBILITY.
   990 
   991 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   992 
   993 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   994 'class' instead.
   995 
   996 * Command 'code_reflect' allows to incorporate generated ML code into
   997 runtime environment; replaces immature code_datatype antiquotation.
   998 INCOMPATIBILITY.
   999 
  1000 * Code generator: simple concept for abstract datatypes obeying
  1001 invariants.
  1002 
  1003 * Code generator: details of internal data cache have no impact on the
  1004 user space functionality any longer.
  1005 
  1006 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1007 subgoals.  This is more appropriate for interpretations with 'where'.
  1008 INCOMPATIBILITY.
  1009 
  1010 * Command 'example_proof' opens an empty proof body.  This allows to
  1011 experiment with Isar, without producing any persistent result.
  1012 
  1013 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1014 within a local theory context, with explicit checking of the
  1015 constructors involved (in contrast to the raw 'syntax' versions).
  1016 
  1017 * Commands 'types' and 'typedecl' now work within a local theory
  1018 context -- without introducing dependencies on parameters or
  1019 assumptions, which is not possible in Isabelle/Pure.
  1020 
  1021 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1022 within a local theory context.  Minor INCOMPATIBILITY.
  1023 
  1024 
  1025 *** HOL ***
  1026 
  1027 * Command 'typedef' now works within a local theory context -- without
  1028 introducing dependencies on parameters or assumptions, which is not
  1029 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1030 contain multiple interpretations of local typedefs (with different
  1031 non-emptiness proofs), even in a global theory context.
  1032 
  1033 * New package for quotient types.  Commands 'quotient_type' and
  1034 'quotient_definition' may be used for defining types and constants by
  1035 quotient constructions.  An example is the type of integers created by
  1036 quotienting pairs of natural numbers:
  1037 
  1038   fun
  1039     intrel :: "(nat * nat) => (nat * nat) => bool"
  1040   where
  1041     "intrel (x, y) (u, v) = (x + v = u + y)"
  1042 
  1043   quotient_type int = "nat * nat" / intrel
  1044     by (auto simp add: equivp_def expand_fun_eq)
  1045 
  1046   quotient_definition
  1047     "0::int" is "(0::nat, 0::nat)"
  1048 
  1049 The method "lifting" can be used to lift of theorems from the
  1050 underlying "raw" type to the quotient type.  The example
  1051 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1052 construction and provides a reasoning infrastructure for finite sets.
  1053 
  1054 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1055 clash with new theory Quotient in Main HOL.
  1056 
  1057 * Moved the SMT binding into the main HOL session, eliminating
  1058 separate HOL-SMT session.
  1059 
  1060 * List membership infix mem operation is only an input abbreviation.
  1061 INCOMPATIBILITY.
  1062 
  1063 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1064 for future developements; former Library/Word.thy is still present in
  1065 the AFP entry RSAPPS.
  1066 
  1067 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1068 longer shadowed.  INCOMPATIBILITY.
  1069 
  1070 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1071 INCOMPATIBILITY.
  1072 
  1073 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1074 INCOMPATIBILITY.
  1075 
  1076 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1077 instead.  INCOMPATIBILITY.
  1078 
  1079 * Dropped several real-specific versions of lemmas about floor and
  1080 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1081 instead.  INCOMPATIBILITY.
  1082 
  1083   floor_number_of_eq         ~> floor_number_of
  1084   le_floor_eq_number_of      ~> number_of_le_floor
  1085   le_floor_eq_zero           ~> zero_le_floor
  1086   le_floor_eq_one            ~> one_le_floor
  1087   floor_less_eq_number_of    ~> floor_less_number_of
  1088   floor_less_eq_zero         ~> floor_less_zero
  1089   floor_less_eq_one          ~> floor_less_one
  1090   less_floor_eq_number_of    ~> number_of_less_floor
  1091   less_floor_eq_zero         ~> zero_less_floor
  1092   less_floor_eq_one          ~> one_less_floor
  1093   floor_le_eq_number_of      ~> floor_le_number_of
  1094   floor_le_eq_zero           ~> floor_le_zero
  1095   floor_le_eq_one            ~> floor_le_one
  1096   floor_subtract_number_of   ~> floor_diff_number_of
  1097   floor_subtract_one         ~> floor_diff_one
  1098   ceiling_number_of_eq       ~> ceiling_number_of
  1099   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1100   ceiling_le_zero_eq         ~> ceiling_le_zero
  1101   ceiling_le_eq_one          ~> ceiling_le_one
  1102   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1103   less_ceiling_eq_zero       ~> zero_less_ceiling
  1104   less_ceiling_eq_one        ~> one_less_ceiling
  1105   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1106   ceiling_less_eq_zero       ~> ceiling_less_zero
  1107   ceiling_less_eq_one        ~> ceiling_less_one
  1108   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1109   le_ceiling_eq_zero         ~> zero_le_ceiling
  1110   le_ceiling_eq_one          ~> one_le_ceiling
  1111   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1112   ceiling_subtract_one       ~> ceiling_diff_one
  1113 
  1114 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1115 application of the various fold combinators on finite sets.
  1116 
  1117 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1118 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1119 implementation.  INCOMPATIBILTY.
  1120 
  1121 * Theory Library/Coinductive_List has been removed -- superseded by
  1122 AFP/thys/Coinductive.
  1123 
  1124 * Theory PReal, including the type "preal" and related operations, has
  1125 been removed.  INCOMPATIBILITY.
  1126 
  1127 * Real: new development using Cauchy Sequences.
  1128 
  1129 * Split off theory "Big_Operators" containing setsum, setprod,
  1130 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1131 
  1132 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1133 "Int" etc.  INCOMPATIBILITY.
  1134 
  1135 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1136 
  1137 * New set of rules "ac_simps" provides combined assoc / commute
  1138 rewrites for all interpretations of the appropriate generic locales.
  1139 
  1140 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1141 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1142 appropriate and more consistent names suitable for name prefixes
  1143 within the HOL theories.  INCOMPATIBILITY.
  1144 
  1145 * Some generic constants have been put to appropriate theories:
  1146   - less_eq, less: Orderings
  1147   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1148   - inverse, divide: Rings
  1149 INCOMPATIBILITY.
  1150 
  1151 * More consistent naming of type classes involving orderings (and
  1152 lattices):
  1153 
  1154     lower_semilattice                   ~> semilattice_inf
  1155     upper_semilattice                   ~> semilattice_sup
  1156 
  1157     dense_linear_order                  ~> dense_linorder
  1158 
  1159     pordered_ab_group_add               ~> ordered_ab_group_add
  1160     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1161     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1162     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1163     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1164     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1165     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1166     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1167     pordered_comm_ring                  ~> ordered_comm_ring
  1168     pordered_comm_semiring              ~> ordered_comm_semiring
  1169     pordered_ring                       ~> ordered_ring
  1170     pordered_ring_abs                   ~> ordered_ring_abs
  1171     pordered_semiring                   ~> ordered_semiring
  1172 
  1173     ordered_ab_group_add                ~> linordered_ab_group_add
  1174     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1175     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1176     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1177     ordered_field                       ~> linordered_field
  1178     ordered_field_no_lb                 ~> linordered_field_no_lb
  1179     ordered_field_no_ub                 ~> linordered_field_no_ub
  1180     ordered_field_dense_linear_order    ~> dense_linordered_field
  1181     ordered_idom                        ~> linordered_idom
  1182     ordered_ring                        ~> linordered_ring
  1183     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1184     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1185     ordered_ring_strict                 ~> linordered_ring_strict
  1186     ordered_semidom                     ~> linordered_semidom
  1187     ordered_semiring                    ~> linordered_semiring
  1188     ordered_semiring_1                  ~> linordered_semiring_1
  1189     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1190     ordered_semiring_strict             ~> linordered_semiring_strict
  1191 
  1192   The following slightly odd type classes have been moved to a
  1193   separate theory Library/Lattice_Algebras:
  1194 
  1195     lordered_ab_group_add               ~> lattice_ab_group_add
  1196     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1197     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1198     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1199     lordered_ring                       ~> lattice_ring
  1200 
  1201 INCOMPATIBILITY.
  1202 
  1203 * Refined field classes:
  1204   - classes division_ring_inverse_zero, field_inverse_zero,
  1205     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1206     subsumes former division_by_zero class;
  1207   - numerous lemmas have been ported from field to division_ring.
  1208 INCOMPATIBILITY.
  1209 
  1210 * Refined algebra theorem collections:
  1211   - dropped theorem group group_simps, use algebra_simps instead;
  1212   - dropped theorem group ring_simps, use field_simps instead;
  1213   - proper theorem collection field_simps subsumes former theorem
  1214     groups field_eq_simps and field_simps;
  1215   - dropped lemma eq_minus_self_iff which is a duplicate for
  1216     equal_neg_zero.
  1217 INCOMPATIBILITY.
  1218 
  1219 * Theory Finite_Set and List: some lemmas have been generalized from
  1220 sets to lattices:
  1221 
  1222   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1223   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1224   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1225   union_Union_fold_union        ~> sup_Sup_fold_sup
  1226   Inter_fold_inter              ~> Inf_fold_inf
  1227   Union_fold_union              ~> Sup_fold_sup
  1228   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1229   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1230   INTER_fold_inter              ~> INFI_fold_inf
  1231   UNION_fold_union              ~> SUPR_fold_sup
  1232 
  1233 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1234 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1235 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1236 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1237 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1238 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1239 
  1240 * Reorganized theory Multiset: swapped notation of pointwise and
  1241 multiset order:
  1242 
  1243   - pointwise ordering is instance of class order with standard syntax
  1244     <= and <;
  1245   - multiset ordering has syntax <=# and <#; partial order properties
  1246     are provided by means of interpretation with prefix
  1247     multiset_order;
  1248   - less duplication, less historical organization of sections,
  1249     conversion from associations lists to multisets, rudimentary code
  1250     generation;
  1251   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1252     if needed.
  1253 
  1254 Renamed:
  1255 
  1256   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1257   multi_count_ext  ~>  multiset_ext
  1258   diff_union_inverse2  ~>  diff_union_cancelR
  1259 
  1260 INCOMPATIBILITY.
  1261 
  1262 * Theory Permutation: replaced local "remove" by List.remove1.
  1263 
  1264 * Code generation: ML and OCaml code is decorated with signatures.
  1265 
  1266 * Theory List: added transpose.
  1267 
  1268 * Library/Nat_Bijection.thy is a collection of bijective functions
  1269 between nat and other types, which supersedes the older libraries
  1270 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1271 
  1272   Constants:
  1273   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1274   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1275   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1276   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1277   Countable.pair_encode           ~> prod_encode
  1278   NatIso.prod2nat                 ~> prod_encode
  1279   NatIso.nat2prod                 ~> prod_decode
  1280   NatIso.sum2nat                  ~> sum_encode
  1281   NatIso.nat2sum                  ~> sum_decode
  1282   NatIso.list2nat                 ~> list_encode
  1283   NatIso.nat2list                 ~> list_decode
  1284   NatIso.set2nat                  ~> set_encode
  1285   NatIso.nat2set                  ~> set_decode
  1286 
  1287   Lemmas:
  1288   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1289   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1290   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1291   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1292   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1293   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1294   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1295   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1296   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1297   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1298   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1299   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1300   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1301 
  1302 * Sledgehammer:
  1303   - Renamed ATP commands:
  1304     atp_info     ~> sledgehammer running_atps
  1305     atp_kill     ~> sledgehammer kill_atps
  1306     atp_messages ~> sledgehammer messages
  1307     atp_minimize ~> sledgehammer minimize
  1308     print_atps   ~> sledgehammer available_atps
  1309     INCOMPATIBILITY.
  1310   - Added user's manual ("isabelle doc sledgehammer").
  1311   - Added option syntax and "sledgehammer_params" to customize
  1312     Sledgehammer's behavior.  See the manual for details.
  1313   - Modified the Isar proof reconstruction code so that it produces
  1314     direct proofs rather than proofs by contradiction.  (This feature
  1315     is still experimental.)
  1316   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1317     full-typed mode.
  1318   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1319 
  1320 * Nitpick:
  1321   - Added and implemented "binary_ints" and "bits" options.
  1322   - Added "std" option and implemented support for nonstandard models.
  1323   - Added and implemented "finitize" option to improve the precision
  1324     of infinite datatypes based on a monotonicity analysis.
  1325   - Added support for quotient types.
  1326   - Added support for "specification" and "ax_specification"
  1327     constructs.
  1328   - Added support for local definitions (for "function" and
  1329     "termination" proofs).
  1330   - Added support for term postprocessors.
  1331   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1332   - Improved efficiency of "destroy_constrs" optimization.
  1333   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1334     record getters.
  1335   - Fixed soundness bug related to higher-order constructors.
  1336   - Fixed soundness bug when "full_descrs" is enabled.
  1337   - Improved precision of set constructs.
  1338   - Added "atoms" option.
  1339   - Added cache to speed up repeated Kodkod invocations on the same
  1340     problems.
  1341   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1342     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1343     "SAT4J_Light".  INCOMPATIBILITY.
  1344   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1345     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1346   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1347 
  1348 * Method "induct" now takes instantiations of the form t, where t is not
  1349   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1350   If this is not intended, t has to be enclosed in parentheses.
  1351   By default, the equalities generated by definitional instantiations
  1352   are pre-simplified, which may cause parameters of inductive cases
  1353   to disappear, or may even delete some of the inductive cases.
  1354   Use "induct (no_simp)" instead of "induct" to restore the old
  1355   behaviour. The (no_simp) option is also understood by the "cases"
  1356   and "nominal_induct" methods, which now perform pre-simplification, too.
  1357   INCOMPATIBILITY.
  1358 
  1359 
  1360 *** HOLCF ***
  1361 
  1362 * Variable names in lemmas generated by the domain package have
  1363 changed; the naming scheme is now consistent with the HOL datatype
  1364 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1365 
  1366 * The domain package no longer defines the function "foo_copy" for
  1367 recursive domain "foo".  The reach lemma is now stated directly in
  1368 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1369 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1370 
  1371 * Most definedness lemmas generated by the domain package (previously
  1372 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1373 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1374 Proofs that used definedness lemmas as intro rules may break,
  1375 potential INCOMPATIBILITY.
  1376 
  1377 * Induction and casedist rules generated by the domain package now
  1378 declare proper case_names (one called "bottom", and one named for each
  1379 constructor).  INCOMPATIBILITY.
  1380 
  1381 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1382 rules are generated for each domain, INCOMPATIBILITY.
  1383 
  1384   foo_bar.reach       ~> foo.reach  bar.reach
  1385   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1386 
  1387 * Some lemmas generated by the domain package have been renamed for
  1388 consistency with the datatype package, INCOMPATIBILITY.
  1389 
  1390   foo.ind        ~> foo.induct
  1391   foo.finite_ind ~> foo.finite_induct
  1392   foo.coind      ~> foo.coinduct
  1393   foo.casedist   ~> foo.exhaust
  1394   foo.exhaust    ~> foo.nchotomy
  1395 
  1396 * For consistency with other definition packages, the fixrec package
  1397 now generates qualified theorem names, INCOMPATIBILITY.
  1398 
  1399   foo_simps  ~> foo.simps
  1400   foo_unfold ~> foo.unfold
  1401   foo_induct ~> foo.induct
  1402 
  1403 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1404 method and internal fixrec proofs now use the default simpset instead.
  1405 INCOMPATIBILITY.
  1406 
  1407 * The "contlub" predicate has been removed.  Proof scripts should use
  1408 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1409 
  1410 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1411 
  1412 * The constants cpair, cfst, and csnd have been removed in favor of
  1413 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1414 
  1415 
  1416 *** ML ***
  1417 
  1418 * Antiquotations for basic formal entities:
  1419 
  1420     @{class NAME}         -- type class
  1421     @{class_syntax NAME}  -- syntax representation of the above
  1422 
  1423     @{type_name NAME}     -- logical type
  1424     @{type_abbrev NAME}   -- type abbreviation
  1425     @{nonterminal NAME}   -- type of concrete syntactic category
  1426     @{type_syntax NAME}   -- syntax representation of any of the above
  1427 
  1428     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1429     @{const_abbrev NAME}  -- abbreviated constant
  1430     @{const_syntax NAME}  -- syntax representation of any of the above
  1431 
  1432 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1433 syntax constant (cf. 'syntax' command).
  1434 
  1435 * Antiquotation @{make_string} inlines a function to print arbitrary
  1436 values similar to the ML toplevel.  The result is compiler dependent
  1437 and may fall back on "?" in certain situations.
  1438 
  1439 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1440 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1441 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1442 not work with the asynchronous Isar document model.
  1443 
  1444 * Configuration options now admit dynamic default values, depending on
  1445 the context or even global references.
  1446 
  1447 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1448 uses an efficient external library if available (for Poly/ML).
  1449 
  1450 * Renamed some important ML structures, while keeping the old names
  1451 for some time as aliases within the structure Legacy:
  1452 
  1453   OuterKeyword  ~>  Keyword
  1454   OuterLex      ~>  Token
  1455   OuterParse    ~>  Parse
  1456   OuterSyntax   ~>  Outer_Syntax
  1457   PrintMode     ~>  Print_Mode
  1458   SpecParse     ~>  Parse_Spec
  1459   ThyInfo       ~>  Thy_Info
  1460   ThyLoad       ~>  Thy_Load
  1461   ThyOutput     ~>  Thy_Output
  1462   TypeInfer     ~>  Type_Infer
  1463 
  1464 Note that "open Legacy" simplifies porting of sources, but forgetting
  1465 to remove it again will complicate porting again in the future.
  1466 
  1467 * Most operations that refer to a global context are named
  1468 accordingly, e.g. Simplifier.global_context or
  1469 ProofContext.init_global.  There are some situations where a global
  1470 context actually works, but under normal circumstances one needs to
  1471 pass the proper local context through the code!
  1472 
  1473 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1474 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1475 Pretty.pp argument to merge, which is absent in the standard
  1476 Theory_Data version.
  1477 
  1478 * Sorts.certify_sort and derived "cert" operations for types and terms
  1479 no longer minimize sorts.  Thus certification at the boundary of the
  1480 inference kernel becomes invariant under addition of class relations,
  1481 which is an important monotonicity principle.  Sorts are now minimized
  1482 in the syntax layer only, at the boundary between the end-user and the
  1483 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1484 explicitly in rare situations.
  1485 
  1486 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1487 emphasize that this is in no way a standard operation.
  1488 INCOMPATIBILITY.
  1489 
  1490 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1491 usual for resolution.  Rare INCOMPATIBILITY.
  1492 
  1493 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1494 to emphasize that these only work in a global situation (which is
  1495 quite rare).
  1496 
  1497 * Curried take and drop in library.ML; negative length is interpreted
  1498 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1499 
  1500 * Proof terms: type substitutions on proof constants now use canonical
  1501 order of type variables.  INCOMPATIBILITY for tools working with proof
  1502 terms.
  1503 
  1504 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1505 may no longer carry premises.  User-level specifications are
  1506 transformed accordingly by Thm.add_axiom/add_def.
  1507 
  1508 
  1509 *** System ***
  1510 
  1511 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1512 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1513 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1514 
  1515 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1516 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1517 respectively.
  1518 
  1519 * Old lib/scripts/polyml-platform is superseded by the
  1520 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1521 variant, even on a 64 bit machine.  The following example setting
  1522 prefers 64 bit if available:
  1523 
  1524   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1525 
  1526 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1527 Isabelle/Scala layer for advanced prover interaction and integration.
  1528 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1529 component.
  1530 
  1531 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1532 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1533 similar to the default assignment of the document preparation system
  1534 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1535 provides some operations for direct access to the font without asking
  1536 the user for manual installation.
  1537 
  1538 
  1539 
  1540 New in Isabelle2009-1 (December 2009)
  1541 -------------------------------------
  1542 
  1543 *** General ***
  1544 
  1545 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1546 one backslash should be used, even in ML sources.
  1547 
  1548 
  1549 *** Pure ***
  1550 
  1551 * Locale interpretation propagates mixins along the locale hierarchy.
  1552 The currently only available mixins are the equations used to map
  1553 local definitions to terms of the target domain of an interpretation.
  1554 
  1555 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1556 loc" to print all interpretations of locale "loc" in the theory.
  1557 Interpretations in proofs are not shown.
  1558 
  1559 * Thoroughly revised locales tutorial.  New section on conditional
  1560 interpretation.
  1561 
  1562 * On instantiation of classes, remaining undefined class parameters
  1563 are formally declared.  INCOMPATIBILITY.
  1564 
  1565 
  1566 *** Document preparation ***
  1567 
  1568 * New generalized style concept for printing terms: @{foo (style) ...}
  1569 instead of @{foo_style style ...}  (old form is still retained for
  1570 backward compatibility).  Styles can be also applied for
  1571 antiquotations prop, term_type and typeof.
  1572 
  1573 
  1574 *** HOL ***
  1575 
  1576 * New proof method "smt" for a combination of first-order logic with
  1577 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1578 fixed-size bitvectors; there is also basic support for higher-order
  1579 features (esp. lambda abstractions).  It is an incomplete decision
  1580 procedure based on external SMT solvers using the oracle mechanism;
  1581 for the SMT solver Z3, this method is proof-producing.  Certificates
  1582 are provided to avoid calling the external solvers solely for
  1583 re-checking proofs.  Due to a remote SMT service there is no need for
  1584 installing SMT solvers locally.  See src/HOL/SMT.
  1585 
  1586 * New commands to load and prove verification conditions generated by
  1587 the Boogie program verifier or derived systems (e.g. the Verifying C
  1588 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1589 
  1590 * New counterexample generator tool 'nitpick' based on the Kodkod
  1591 relational model finder.  See src/HOL/Tools/Nitpick and
  1592 src/HOL/Nitpick_Examples.
  1593 
  1594 * New commands 'code_pred' and 'values' to invoke the predicate
  1595 compiler and to enumerate values of inductive predicates.
  1596 
  1597 * A tabled implementation of the reflexive transitive closure.
  1598 
  1599 * New implementation of quickcheck uses generic code generator;
  1600 default generators are provided for all suitable HOL types, records
  1601 and datatypes.  Old quickcheck can be re-activated importing theory
  1602 Library/SML_Quickcheck.
  1603 
  1604 * New testing tool Mirabelle for automated proof tools.  Applies
  1605 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1606 every proof step in a theory.  To be used in batch mode via the
  1607 "mirabelle" utility.
  1608 
  1609 * New proof method "sos" (sum of squares) for nonlinear real
  1610 arithmetic (originally due to John Harison). It requires theory
  1611 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1612 works well in practice on quantifier-free real arithmetic with +, -,
  1613 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1614 inequalities between polynomials.  It makes use of external
  1615 semidefinite programming solvers.  Method "sos" generates a
  1616 certificate that can be pasted into the proof thus avoiding the need
  1617 to call an external tool every time the proof is checked.  See
  1618 src/HOL/Library/Sum_Of_Squares.
  1619 
  1620 * New method "linarith" invokes existing linear arithmetic decision
  1621 procedure only.
  1622 
  1623 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1624 
  1625 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1626 Causes full type information to be output to the ATPs.  This slows
  1627 ATPs down considerably but eliminates a source of unsound "proofs"
  1628 that fail later.
  1629 
  1630 * New method "metisFT": A version of metis that uses full type
  1631 information in order to avoid failures of proof reconstruction.
  1632 
  1633 * New evaluator "approximate" approximates an real valued term using
  1634 the same method as the approximation method.
  1635 
  1636 * Method "approximate" now supports arithmetic expressions as
  1637 boundaries of intervals and implements interval splitting and Taylor
  1638 series expansion.
  1639 
  1640 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1641 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1642 
  1643 * New theory SupInf of the supremum and infimum operators for sets of
  1644 reals.
  1645 
  1646 * New theory Probability, which contains a development of measure
  1647 theory, eventually leading to Lebesgue integration and probability.
  1648 
  1649 * Extended Multivariate Analysis to include derivation and Brouwer's
  1650 fixpoint theorem.
  1651 
  1652 * Reorganization of number theory, INCOMPATIBILITY:
  1653   - new number theory development for nat and int, in theories Divides
  1654     and GCD as well as in new session Number_Theory
  1655   - some constants and facts now suffixed with _nat and _int
  1656     accordingly
  1657   - former session NumberTheory now named Old_Number_Theory, including
  1658     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1659   - moved theory Pocklington from src/HOL/Library to
  1660     src/HOL/Old_Number_Theory
  1661 
  1662 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1663 lcm of finite and infinite sets. It is shown that they form a complete
  1664 lattice.
  1665 
  1666 * Class semiring_div requires superclass no_zero_divisors and proof of
  1667 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1668 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1669 generalized to class semiring_div, subsuming former theorems
  1670 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1671 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1672 INCOMPATIBILITY.
  1673 
  1674 * Refinements to lattice classes and sets:
  1675   - less default intro/elim rules in locale variant, more default
  1676     intro/elim rules in class variant: more uniformity
  1677   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1678     le_inf_iff
  1679   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1680     sup_aci)
  1681   - renamed ACI to inf_sup_aci
  1682   - new class "boolean_algebra"
  1683   - class "complete_lattice" moved to separate theory
  1684     "Complete_Lattice"; corresponding constants (and abbreviations)
  1685     renamed and with authentic syntax:
  1686     Set.Inf ~>    Complete_Lattice.Inf
  1687     Set.Sup ~>    Complete_Lattice.Sup
  1688     Set.INFI ~>   Complete_Lattice.INFI
  1689     Set.SUPR ~>   Complete_Lattice.SUPR
  1690     Set.Inter ~>  Complete_Lattice.Inter
  1691     Set.Union ~>  Complete_Lattice.Union
  1692     Set.INTER ~>  Complete_Lattice.INTER
  1693     Set.UNION ~>  Complete_Lattice.UNION
  1694   - authentic syntax for
  1695     Set.Pow
  1696     Set.image
  1697   - mere abbreviations:
  1698     Set.empty               (for bot)
  1699     Set.UNIV                (for top)
  1700     Set.inter               (for inf, formerly Set.Int)
  1701     Set.union               (for sup, formerly Set.Un)
  1702     Complete_Lattice.Inter  (for Inf)
  1703     Complete_Lattice.Union  (for Sup)
  1704     Complete_Lattice.INTER  (for INFI)
  1705     Complete_Lattice.UNION  (for SUPR)
  1706   - object-logic definitions as far as appropriate
  1707 
  1708 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1709 Un_subset_iff are explicitly deleted as default simp rules; then also
  1710 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1711 deleted to achieve the desired effect.
  1712 
  1713 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1714 rules by default any longer; the same applies to min_max.inf_absorb1
  1715 etc.  INCOMPATIBILITY.
  1716 
  1717 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1718 pred_set_conv by default.  INCOMPATIBILITY.
  1719 
  1720 * Power operations on relations and functions are now one dedicated
  1721 constant "compow" with infix syntax "^^".  Power operation on
  1722 multiplicative monoids retains syntax "^" and is now defined generic
  1723 in class power.  INCOMPATIBILITY.
  1724 
  1725 * Relation composition "R O S" now has a more standard argument order:
  1726 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1727 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1728 break, since the O_assoc rule was not rewritten like this.  Fix using
  1729 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1730 
  1731 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1732 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1733 INCOMPATIBILITY.
  1734 
  1735 * Most rules produced by inductive and datatype package have mandatory
  1736 prefixes.  INCOMPATIBILITY.
  1737 
  1738 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1739 the attribute of the same name.  Each of the theorems in the list
  1740 DERIV_intros assumes composition with an additional function and
  1741 matches a variable to the derivative, which has to be solved by the
  1742 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1743 of most elementary terms.  Former Maclauren.DERIV_tac and
  1744 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1745 INCOMPATIBILITY.
  1746 
  1747 * Code generator attributes follow the usual underscore convention:
  1748     code_unfold     replaces    code unfold
  1749     code_post       replaces    code post
  1750     etc.
  1751   INCOMPATIBILITY.
  1752 
  1753 * Renamed methods:
  1754     sizechange -> size_change
  1755     induct_scheme -> induction_schema
  1756   INCOMPATIBILITY.
  1757 
  1758 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1759 INCOMPATIBILITY, use "undefined" directly.
  1760 
  1761 * Renamed theorems:
  1762     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1763     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1764     Suc_plus1 -> Suc_eq_plus1
  1765     *anti_sym -> *antisym*
  1766     vector_less_eq_def -> vector_le_def
  1767   INCOMPATIBILITY.
  1768 
  1769 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1770 INCOMPATIBILITY.
  1771 
  1772 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1773 INCOMPATIBILITY.
  1774 
  1775 
  1776 *** HOLCF ***
  1777 
  1778 * Theory Representable defines a class "rep" of domains that are
  1779 representable (via an ep-pair) in the universal domain type "udom".
  1780 Instances are provided for all type constructors defined in HOLCF.
  1781 
  1782 * The 'new_domain' command is a purely definitional version of the
  1783 domain package, for representable domains.  Syntax is identical to the
  1784 old domain package.  The 'new_domain' package also supports indirect
  1785 recursion using previously-defined type constructors.  See
  1786 src/HOLCF/ex/New_Domain.thy for examples.
  1787 
  1788 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1789 on the left-hand side of an equation, and then performs
  1790 simplification.  Rewriting is done using rules declared with the
  1791 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1792 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1793 
  1794 * The pattern-match compiler in 'fixrec' can now handle constructors
  1795 with HOL function types.  Pattern-match combinators for the Pair
  1796 constructor are pre-configured.
  1797 
  1798 * The 'fixrec' package now produces better fixed-point induction rules
  1799 for mutually-recursive definitions:  Induction rules have conclusions
  1800 of the form "P foo bar" instead of "P <foo, bar>".
  1801 
  1802 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1803 been renamed to "below".  The name "below" now replaces "less" in many
  1804 theorem names.  (Legacy theorem names using "less" are still supported
  1805 as well.)
  1806 
  1807 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1808 patterns can be used to generate strictness rules, or to make
  1809 functions more strict (much like the bang-patterns supported by the
  1810 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1811 examples.
  1812 
  1813 
  1814 *** ML ***
  1815 
  1816 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1817 errors and run-time exceptions, including detailed source positions.
  1818 
  1819 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1820 identified entries, with some additional information such as source
  1821 position, logical grouping etc.
  1822 
  1823 * Theory and context data is now introduced by the simplified and
  1824 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1825 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1826 copy operation) is still available for some time.
  1827 
  1828 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1829 provides a high-level programming interface to synchronized state
  1830 variables with atomic update.  This works via pure function
  1831 application within a critical section -- its runtime should be as
  1832 short as possible; beware of deadlocks if critical code is nested,
  1833 either directly or indirectly via other synchronized variables!
  1834 
  1835 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1836 wraps raw ML references, explicitly indicating their non-thread-safe
  1837 behaviour.  The Isar toplevel keeps this structure open, to
  1838 accommodate Proof General as well as quick and dirty interactive
  1839 experiments with references.
  1840 
  1841 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1842 parallel tactical reasoning.
  1843 
  1844 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1845 are similar to SUBPROOF, but are slightly more flexible: only the
  1846 specified parts of the subgoal are imported into the context, and the
  1847 body tactic may introduce new subgoals and schematic variables.
  1848 
  1849 * Old tactical METAHYPS, which does not observe the proof context, has
  1850 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1851 or Subgoal.FOCUS etc.
  1852 
  1853 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1854 functors have their own ML name space there is no point to mark them
  1855 separately.)  Minor INCOMPATIBILITY.
  1856 
  1857 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1858 
  1859 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1860 INCOMPATIBILITY.
  1861 
  1862 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1863 mode, which avoids critical setmp.
  1864 
  1865 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1866 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1867 Attrib/Method.setup introduced in Isabelle2009.
  1868 
  1869 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1870 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1871 last resort.  INCOMPATIBILITY.
  1872 
  1873 * Display.pretty_thm now requires a proper context (cf. former
  1874 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1875 or even Display.pretty_thm_without_context as last resort.
  1876 INCOMPATIBILITY.
  1877 
  1878 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1879 Syntax.pretty_typ/term directly, preferably with proper context
  1880 instead of global theory.
  1881 
  1882 
  1883 *** System ***
  1884 
  1885 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1886 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1887 usedir option -q.
  1888 
  1889 * Support for additional "Isabelle components" via etc/components, see
  1890 also the system manual.
  1891 
  1892 * The isabelle makeall tool now operates on all components with
  1893 IsaMakefile, not just hardwired "logics".
  1894 
  1895 * Removed "compress" option from isabelle-process and isabelle usedir;
  1896 this is always enabled.
  1897 
  1898 * Discontinued support for Poly/ML 4.x versions.
  1899 
  1900 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1901 on a given logic image.  This requires the lighttpd webserver and is
  1902 currently supported on Linux only.
  1903 
  1904 
  1905 
  1906 New in Isabelle2009 (April 2009)
  1907 --------------------------------
  1908 
  1909 *** General ***
  1910 
  1911 * Simplified main Isabelle executables, with less surprises on
  1912 case-insensitive file-systems (such as Mac OS).
  1913 
  1914   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1915     "isatool."
  1916 
  1917   - The former "isabelle" alias for "isabelle-process" has been
  1918     removed (should rarely occur to regular users).
  1919 
  1920   - The former "isabelle-interface" and its alias "Isabelle" have been
  1921     removed (interfaces are now regular Isabelle tools).
  1922 
  1923 Within scripts and make files, the Isabelle environment variables
  1924 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1925 respectively.  (The latter are still available as legacy feature.)
  1926 
  1927 The old isabelle-interface wrapper could react in confusing ways if
  1928 the interface was uninstalled or changed otherwise.  Individual
  1929 interface tool configuration is now more explicit, see also the
  1930 Isabelle system manual.  In particular, Proof General is now available
  1931 via "isabelle emacs".
  1932 
  1933 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1934 purge installed copies of Isabelle executables and re-run "isabelle
  1935 install -p ...", or use symlinks.
  1936 
  1937 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1938 old ~/isabelle, which was slightly non-standard and apt to cause
  1939 surprises on case-insensitive file-systems (such as Mac OS).
  1940 
  1941 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1942 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1943 care is required when using older releases of Isabelle.  Note that
  1944 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1945 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1946 
  1947 * Proofs of fully specified statements are run in parallel on
  1948 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1949 a regular 4-core machine, if the initial heap space is made reasonably
  1950 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1951 
  1952 * The main reference manuals ("isar-ref", "implementation", and
  1953 "system") have been updated and extended.  Formally checked references
  1954 as hyperlinks are now available uniformly.
  1955 
  1956 
  1957 *** Pure ***
  1958 
  1959 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1960 respects.  The most important changes are listed below.  See the
  1961 Tutorial on Locales ("locales" manual) for details.
  1962 
  1963 - In locale expressions, instantiation replaces renaming.  Parameters
  1964 must be declared in a for clause.  To aid compatibility with previous
  1965 parameter inheritance, in locale declarations, parameters that are not
  1966 'touched' (instantiation position "_" or omitted) are implicitly added
  1967 with their syntax at the beginning of the for clause.
  1968 
  1969 - Syntax from abbreviations and definitions in locales is available in
  1970 locale expressions and context elements.  The latter is particularly
  1971 useful in locale declarations.
  1972 
  1973 - More flexible mechanisms to qualify names generated by locale
  1974 expressions.  Qualifiers (prefixes) may be specified in locale
  1975 expressions, and can be marked as mandatory (syntax: "name!:") or
  1976 optional (syntax "name?:").  The default depends for plain "name:"
  1977 depends on the situation where a locale expression is used: in
  1978 commands 'locale' and 'sublocale' prefixes are optional, in
  1979 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1980 implicit qualifiers derived from the parameter names of a locale are
  1981 no longer generated.
  1982 
  1983 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1984 instantiation clause in "interpretation" and "interpret" (square
  1985 brackets) is no longer available.  Use locale expressions.
  1986 
  1987 - When converting proof scripts, mandatory qualifiers in
  1988 'interpretation' and 'interpret' should be retained by default, even
  1989 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1990 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1991 in locale expressions range over a single locale instance only.
  1992 
  1993 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1994 In existing theorem specifications replace the includes element by the
  1995 respective context elements of the included locale, omitting those
  1996 that are already present in the theorem specification.  Multiple
  1997 assume elements of a locale should be replaced by a single one
  1998 involving the locale predicate.  In the proof body, declarations (most
  1999 notably theorems) may be regained by interpreting the respective
  2000 locales in the proof context as required (command "interpret").
  2001 
  2002 If using "includes" in replacement of a target solely because the
  2003 parameter types in the theorem are not as general as in the target,
  2004 consider declaring a new locale with additional type constraints on
  2005 the parameters (context element "constrains").
  2006 
  2007 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2008 
  2009 - Locale interpretation commands no longer attempt to simplify goal.
  2010 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2011 methods intro_locales and unfold_locales to clarify.
  2012 
  2013 - Locale interpretation commands no longer accept interpretation
  2014 attributes.  INCOMPATIBILITY.
  2015 
  2016 * Class declaration: so-called "base sort" must not be given in import
  2017 list any longer, but is inferred from the specification.  Particularly
  2018 in HOL, write
  2019 
  2020     class foo = ...
  2021 
  2022 instead of
  2023 
  2024     class foo = type + ...
  2025 
  2026 * Class target: global versions of theorems stemming do not carry a
  2027 parameter prefix any longer.  INCOMPATIBILITY.
  2028 
  2029 * Class 'instance' command no longer accepts attached definitions.
  2030 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2031 
  2032 * Recovered hiding of consts, which was accidentally broken in
  2033 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2034 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2035 
  2036 * Slightly more coherent Pure syntax, with updated documentation in
  2037 isar-ref manual.  Removed locales meta_term_syntax and
  2038 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2039 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2040 directly in regular applications.
  2041 
  2042 * There is a new syntactic category "float_const" for signed decimal
  2043 fractions (e.g. 123.45 or -123.45).
  2044 
  2045 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2046 interface with 'setup' command instead.
  2047 
  2048 * Command 'local_setup' is similar to 'setup', but operates on a local
  2049 theory context.
  2050 
  2051 * The 'axiomatization' command now only works within a global theory
  2052 context.  INCOMPATIBILITY.
  2053 
  2054 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2055 hypotheses.  Sorts required in the course of reasoning need to be
  2056 covered by the constraints in the initial statement, completed by the
  2057 type instance information of the background theory.  Non-trivial sort
  2058 hypotheses, which rarely occur in practice, may be specified via
  2059 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2060 
  2061   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2062 
  2063 The result contains an implicit sort hypotheses as before --
  2064 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2065 normalization.
  2066 
  2067 * Generalized Isar history, with support for linear undo, direct state
  2068 addressing etc.
  2069 
  2070 * Changed defaults for unify configuration options:
  2071 
  2072   unify_trace_bound = 50 (formerly 25)
  2073   unify_search_bound = 60 (formerly 30)
  2074 
  2075 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2076 
  2077   a) On theory merge, the last set of code equations for a particular
  2078      constant is taken (in accordance with the policy applied by other
  2079      parts of the code generator framework).
  2080 
  2081   b) Code equations stemming from explicit declarations (e.g. code
  2082      attribute) gain priority over default code equations stemming
  2083      from definition, primrec, fun etc.
  2084 
  2085 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2086 
  2087 * Unified theorem tables for both code generators.  Thus [code
  2088 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2089 
  2090 * Command 'find_consts' searches for constants based on type and name
  2091 patterns, e.g.
  2092 
  2093     find_consts "_ => bool"
  2094 
  2095 By default, matching is against subtypes, but it may be restricted to
  2096 the whole type.  Searching by name is possible.  Multiple queries are
  2097 conjunctive and queries may be negated by prefixing them with a
  2098 hyphen:
  2099 
  2100     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2101 
  2102 * New 'find_theorems' criterion "solves" matches theorems that
  2103 directly solve the current goal (modulo higher-order unification).
  2104 
  2105 * Auto solve feature for main theorem statements: whenever a new goal
  2106 is stated, "find_theorems solves" is called; any theorems that could
  2107 solve the lemma directly are listed as part of the goal state.
  2108 Cf. associated options in Proof General Isabelle settings menu,
  2109 enabled by default, with reasonable timeout for pathological cases of
  2110 higher-order unification.
  2111 
  2112 
  2113 *** Document preparation ***
  2114 
  2115 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2116 demanding keyword 'by' and supporting the full method expression
  2117 syntax just like the Isar command 'by'.
  2118 
  2119 
  2120 *** HOL ***
  2121 
  2122 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2123 points Main and Complex_Main remain as before.
  2124 
  2125 * Logic image HOL-Plain provides a minimal HOL with the most important
  2126 tools available (inductive, datatype, primrec, ...).  This facilitates
  2127 experimentation and tool development.  Note that user applications
  2128 (and library theories) should never refer to anything below theory
  2129 Main, as before.
  2130 
  2131 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2132 experimentation due to shorter build times.
  2133 
  2134 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2135 were previously part of former HOL-Complex.  Entry point Hyperreal
  2136 remains valid, but theories formerly using Complex_Main should now use
  2137 new entry point Hypercomplex.
  2138 
  2139 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2140 Posix processes.  Avoids potentially expensive forking of the ML
  2141 process.  New thread-based implementation also works on non-Unix
  2142 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2143 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2144 commands are covered in the isar-ref manual.
  2145 
  2146 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2147 sledgehammer without local ATP installation (Vampire etc.). Other
  2148 provers may be included via suitable ML wrappers, see also
  2149 src/HOL/ATP_Linkup.thy.
  2150 
  2151 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2152 menu.
  2153 
  2154 * The metis method no longer fails because the theorem is too trivial
  2155 (contains the empty clause).
  2156 
  2157 * The metis method now fails in the usual manner, rather than raising
  2158 an exception, if it determines that it cannot prove the theorem.
  2159 
  2160 * Method "coherent" implements a prover for coherent logic (see also
  2161 src/Tools/coherent.ML).
  2162 
  2163 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2164 "undefined" is the right choice to replace "arbitrary", though
  2165 logically there is no difference.  INCOMPATIBILITY.
  2166 
  2167 * Command "value" now integrates different evaluation mechanisms.  The
  2168 result of the first successful evaluation mechanism is printed.  In
  2169 square brackets a particular named evaluation mechanisms may be
  2170 specified (currently, [SML], [code] or [nbe]).  See further
  2171 src/HOL/ex/Eval_Examples.thy.
  2172 
  2173 * Normalization by evaluation now allows non-leftlinear equations.
  2174 Declare with attribute [code nbe].
  2175 
  2176 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2177 as the structured Isar versions "cases" and "induct", cf. the
  2178 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2179 are now presented as a list of individual projections
  2180 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2181 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2182 rare situations a different rule is selected --- notably nested tuple
  2183 elimination instead of former prod.exhaust: use explicit (case_tac t
  2184 rule: prod.exhaust) here.
  2185 
  2186 * Attributes "cases", "induct", "coinduct" support "del" option.
  2187 
  2188 * Removed fact "case_split_thm", which duplicates "case_split".
  2189 
  2190 * The option datatype has been moved to a new theory Option.  Renamed
  2191 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2192 
  2193 * New predicate "strict_mono" classifies strict functions on partial
  2194 orders.  With strict functions on linear orders, reasoning about
  2195 (in)equalities is facilitated by theorems "strict_mono_eq",
  2196 "strict_mono_less_eq" and "strict_mono_less".
  2197 
  2198 * Some set operations are now proper qualified constants with
  2199 authentic syntax.  INCOMPATIBILITY:
  2200 
  2201     op Int ~>   Set.Int
  2202     op Un ~>    Set.Un
  2203     INTER ~>    Set.INTER
  2204     UNION ~>    Set.UNION
  2205     Inter ~>    Set.Inter
  2206     Union ~>    Set.Union
  2207     {} ~>       Set.empty
  2208     UNIV ~>     Set.UNIV
  2209 
  2210 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2211 theory Set.
  2212 
  2213 * Auxiliary class "itself" has disappeared -- classes without any
  2214 parameter are treated as expected by the 'class' command.
  2215 
  2216 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2217 
  2218 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2219 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2220 
  2221 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2222 method "approximation".  It proves formulas on real values by using
  2223 interval arithmetic.  In the formulas are also the transcendental
  2224 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2225 allowed. For examples see
  2226 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2227 
  2228 * Theory "Reflection" now resides in HOL/Library.
  2229 
  2230 * Entry point to Word library now simply named "Word".
  2231 INCOMPATIBILITY.
  2232 
  2233 * Made source layout more coherent with logical distribution
  2234 structure:
  2235 
  2236     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2237     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2238     src/HOL/Library/GCD.thy ~> src/HOL/
  2239     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2240     src/HOL/Library/Parity.thy ~> src/HOL/
  2241     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2242     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2243     src/HOL/Real/Lubs.thy ~> src/HOL/
  2244     src/HOL/Real/PReal.thy ~> src/HOL/
  2245     src/HOL/Real/Rational.thy ~> src/HOL/
  2246     src/HOL/Real/RComplete.thy ~> src/HOL/
  2247     src/HOL/Real/RealDef.thy ~> src/HOL/
  2248     src/HOL/Real/RealPow.thy ~> src/HOL/
  2249     src/HOL/Real/Real.thy ~> src/HOL/
  2250     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2251     src/HOL/Complex/Complex.thy ~> src/HOL/
  2252     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2253     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2254     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2255     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2256     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2257     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2258     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2259     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2260     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2261     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2262     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2263     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2264     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2265     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2266     src/HOL/Real/Float ~> src/HOL/Library/
  2267     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2268     src/HOL/Real/RealVector.thy ~> src/HOL/
  2269 
  2270     src/HOL/arith_data.ML ~> src/HOL/Tools
  2271     src/HOL/hologic.ML ~> src/HOL/Tools
  2272     src/HOL/simpdata.ML ~> src/HOL/Tools
  2273     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2274     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2275     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2276     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2277     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2278     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2279     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2280 
  2281     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2282     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2283     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2284     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2285     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2286     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2287 
  2288 * If methods "eval" and "evaluation" encounter a structured proof
  2289 state with !!/==>, only the conclusion is evaluated to True (if
  2290 possible), avoiding strange error messages.
  2291 
  2292 * Method "sizechange" automates termination proofs using (a
  2293 modification of) the size-change principle.  Requires SAT solver.  See
  2294 src/HOL/ex/Termination.thy for examples.
  2295 
  2296 * Simplifier: simproc for let expressions now unfolds if bound
  2297 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2298 
  2299 * Method "arith": Linear arithmetic now ignores all inequalities when
  2300 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2301 
  2302 * New attribute "arith" for facts that should always be used
  2303 automatically by arithmetic. It is intended to be used locally in
  2304 proofs, e.g.
  2305 
  2306   assumes [arith]: "x > 0"
  2307 
  2308 Global usage is discouraged because of possible performance impact.
  2309 
  2310 * New classes "top" and "bot" with corresponding operations "top" and
  2311 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2312 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2313 
  2314 * Changed definition lemma "less_fun_def" in order to provide an
  2315 instance for preorders on functions; use lemma "less_le" instead.
  2316 INCOMPATIBILITY.
  2317 
  2318 * Theory Orderings: class "wellorder" moved here, with explicit
  2319 induction rule "less_induct" as assumption.  For instantiation of
  2320 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2321 INCOMPATIBILITY.
  2322 
  2323 * Theory Orderings: added class "preorder" as superclass of "order".
  2324 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2325 etc. slightly changed.  Some theorems named order_class.* now named
  2326 preorder_class.*.
  2327 
  2328 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2329 "diag" to "Id_on".
  2330 
  2331 * Theory Finite_Set: added a new fold combinator of type
  2332 
  2333   ('a => 'b => 'b) => 'b => 'a set => 'b
  2334 
  2335 Occasionally this is more convenient than the old fold combinator
  2336 which is now defined in terms of the new one and renamed to
  2337 fold_image.
  2338 
  2339 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2340 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2341 extended with further lemmas!).  At the moment both still exist but
  2342 the former will disappear at some point.
  2343 
  2344 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2345 class recpower.  Type-specific simp rules for various recpower types
  2346 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2347 
  2348 rat_power_0    -> power_0
  2349 rat_power_Suc  -> power_Suc
  2350 realpow_0      -> power_0
  2351 realpow_Suc    -> power_Suc
  2352 complexpow_0   -> power_0
  2353 complexpow_Suc -> power_Suc
  2354 power_poly_0   -> power_0
  2355 power_poly_Suc -> power_Suc
  2356 
  2357 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2358 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2359 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2360 of lemmas from Divides has been generalized from nat to class
  2361 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2362 renames resulting from duplicate elimination:
  2363 
  2364     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2365     zero_dvd_iff ~>         dvd_0_left_iff
  2366     dvd_0 ~>                dvd_0_right
  2367     DIVISION_BY_ZERO_DIV ~> div_by_0
  2368     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2369     mult_div ~>             div_mult_self2_is_id
  2370     mult_mod ~>             mod_mult_self2_is_0
  2371 
  2372 * Theory IntDiv: removed many lemmas that are instances of class-based
  2373 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2374 rename old lemmas as follows:
  2375 
  2376 dvd_diff               -> nat_dvd_diff
  2377 dvd_zminus_iff         -> dvd_minus_iff
  2378 mod_add1_eq            -> mod_add_eq
  2379 mod_mult1_eq           -> mod_mult_right_eq
  2380 mod_mult1_eq'          -> mod_mult_left_eq
  2381 mod_mult_distrib_mod   -> mod_mult_eq
  2382 nat_mod_add_left_eq    -> mod_add_left_eq
  2383 nat_mod_add_right_eq   -> mod_add_right_eq
  2384 nat_mod_div_trivial    -> mod_div_trivial
  2385 nat_mod_mod_trivial    -> mod_mod_trivial
  2386 zdiv_zadd_self1        -> div_add_self1
  2387 zdiv_zadd_self2        -> div_add_self2
  2388 zdiv_zmult_self1       -> div_mult_self2_is_id
  2389 zdiv_zmult_self2       -> div_mult_self1_is_id
  2390 zdvd_triv_left         -> dvd_triv_left
  2391 zdvd_triv_right        -> dvd_triv_right
  2392 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2393 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2394 zmod_zadd_left_eq      -> mod_add_left_eq
  2395 zmod_zadd_right_eq     -> mod_add_right_eq
  2396 zmod_zadd_self1        -> mod_add_self1
  2397 zmod_zadd_self2        -> mod_add_self2
  2398 zmod_zadd1_eq          -> mod_add_eq
  2399 zmod_zdiff1_eq         -> mod_diff_eq
  2400 zmod_zdvd_zmod         -> mod_mod_cancel
  2401 zmod_zmod_cancel       -> mod_mod_cancel
  2402 zmod_zmult_self1       -> mod_mult_self2_is_0
  2403 zmod_zmult_self2       -> mod_mult_self1_is_0
  2404 zmod_1                 -> mod_by_1
  2405 zdiv_1                 -> div_by_1
  2406 zdvd_abs1              -> abs_dvd_iff
  2407 zdvd_abs2              -> dvd_abs_iff
  2408 zdvd_refl              -> dvd_refl
  2409 zdvd_trans             -> dvd_trans
  2410 zdvd_zadd              -> dvd_add
  2411 zdvd_zdiff             -> dvd_diff
  2412 zdvd_zminus_iff        -> dvd_minus_iff
  2413 zdvd_zminus2_iff       -> minus_dvd_iff
  2414 zdvd_zmultD            -> dvd_mult_right
  2415 zdvd_zmultD2           -> dvd_mult_left
  2416 zdvd_zmult_mono        -> mult_dvd_mono
  2417 zdvd_0_right           -> dvd_0_right
  2418 zdvd_0_left            -> dvd_0_left_iff
  2419 zdvd_1_left            -> one_dvd
  2420 zminus_dvd_iff         -> minus_dvd_iff
  2421 
  2422 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2423 
  2424 * The real numbers offer decimal input syntax: 12.34 is translated
  2425 into 1234/10^2. This translation is not reversed upon output.
  2426 
  2427 * Theory Library/Polynomial defines an abstract type 'a poly of
  2428 univariate polynomials with coefficients of type 'a.  In addition to
  2429 the standard ring operations, it also supports div and mod.  Code
  2430 generation is also supported, using list-style constructors.
  2431 
  2432 * Theory Library/Inner_Product defines a class of real_inner for real
  2433 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2434 => real.  Class real_inner is a subclass of real_normed_vector from
  2435 theory RealVector.
  2436 
  2437 * Theory Library/Product_Vector provides instances for the product
  2438 type 'a * 'b of several classes from RealVector and Inner_Product.
  2439 Definitions of addition, subtraction, scalar multiplication, norms,
  2440 and inner products are included.
  2441 
  2442 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2443 addition to the field operations, numerals and case syntax are also
  2444 supported.
  2445 
  2446 * Theory Library/Diagonalize provides constructive version of Cantor's
  2447 first diagonalization argument.
  2448 
  2449 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2450 zlcm (for int); carried together from various gcd/lcm developements in
  2451 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2452 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2453 may recover tupled syntax as follows:
  2454 
  2455     hide (open) const gcd
  2456     abbreviation gcd where
  2457       "gcd == (%(a, b). GCD.gcd a b)"
  2458     notation (output)
  2459       GCD.gcd ("gcd '(_, _')")
  2460 
  2461 The same works for lcm, zgcd, zlcm.
  2462 
  2463 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2464 instantiations for algebraic structures.  Removed some duplicate
  2465 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2466 
  2467 * ML antiquotation @{code} takes a constant as argument and generates
  2468 corresponding code in background and inserts name of the corresponding
  2469 resulting ML value/function/datatype constructor binding in place.
  2470 All occurrences of @{code} with a single ML block are generated
  2471 simultaneously.  Provides a generic and safe interface for
  2472 instrumentalizing code generation.  See
  2473 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2474 In future you ought to refrain from ad-hoc compiling generated SML
  2475 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2476 cannot refer to constants for which user-defined serializations are
  2477 set.  Refer to the corresponding ML counterpart directly in that
  2478 cases.
  2479 
  2480 * Command 'rep_datatype': instead of theorem names the command now
  2481 takes a list of terms denoting the constructors of the type to be
  2482 represented as datatype.  The characteristic theorems have to be
  2483 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2484 have disappeared in favour of existing ones:
  2485 
  2486     unit_induct                 ~> unit.induct
  2487     prod_induct                 ~> prod.induct
  2488     sum_induct                  ~> sum.induct
  2489     Suc_Suc_eq                  ~> nat.inject
  2490     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2491 
  2492 
  2493 *** HOL-Algebra ***
  2494 
  2495 * New locales for orders and lattices where the equivalence relation
  2496 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2497 locales use a record structure with field eq for the equivalence.
  2498 
  2499 * New theory of factorial domains.
  2500 
  2501 * Units_l_inv and Units_r_inv are now simp rules by default.
  2502 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2503 and/or r_inv will now also require deletion of these lemmas.
  2504 
  2505 * Renamed the following theorems, INCOMPATIBILITY:
  2506 
  2507 UpperD ~> Upper_memD
  2508 LowerD ~> Lower_memD
  2509 least_carrier ~> least_closed
  2510 greatest_carrier ~> greatest_closed
  2511 greatest_Lower_above ~> greatest_Lower_below
  2512 one_zero ~> carrier_one_zero
  2513 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2514 
  2515 
  2516 *** HOL-Nominal ***
  2517 
  2518 * Nominal datatypes can now contain type-variables.
  2519 
  2520 * Commands 'nominal_inductive' and 'equivariance' work with local
  2521 theory targets.
  2522 
  2523 * Nominal primrec can now works with local theory targets and its
  2524 specification syntax now conforms to the general format as seen in
  2525 'inductive' etc.
  2526 
  2527 * Method "perm_simp" honours the standard simplifier attributes
  2528 (no_asm), (no_asm_use) etc.
  2529 
  2530 * The new predicate #* is defined like freshness, except that on the
  2531 left hand side can be a set or list of atoms.
  2532 
  2533 * Experimental command 'nominal_inductive2' derives strong induction
  2534 principles for inductive definitions.  In contrast to
  2535 'nominal_inductive', which can only deal with a fixed number of
  2536 binders, it can deal with arbitrary expressions standing for sets of
  2537 atoms to be avoided.  The only inductive definition we have at the
  2538 moment that needs this generalisation is the typing rule for Lets in
  2539 the algorithm W:
  2540 
  2541  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2542  -----------------------------------------------------------------
  2543          Gamma |- Let x be t1 in t2 : T2
  2544 
  2545 In this rule one wants to avoid all the binders that are introduced by
  2546 "close Gamma T1".  We are looking for other examples where this
  2547 feature might be useful.  Please let us know.
  2548 
  2549 
  2550 *** HOLCF ***
  2551 
  2552 * Reimplemented the simplification procedure for proving continuity
  2553 subgoals.  The new simproc is extensible; users can declare additional
  2554 continuity introduction rules with the attribute [cont2cont].
  2555 
  2556 * The continuity simproc now uses a different introduction rule for
  2557 solving continuity subgoals on terms with lambda abstractions.  In
  2558 some rare cases the new simproc may fail to solve subgoals that the
  2559 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2560 Potential INCOMPATIBILITY.
  2561 
  2562 * Command 'fixrec': specification syntax now conforms to the general
  2563 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2564 examples.  INCOMPATIBILITY.
  2565 
  2566 
  2567 *** ZF ***
  2568 
  2569 * Proof of Zorn's Lemma for partial orders.
  2570 
  2571 
  2572 *** ML ***
  2573 
  2574 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2575 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2576 depends on multithreading, so timouts will not work before Poly/ML
  2577 5.2.1!
  2578 
  2579 * High-level support for concurrent ML programming, see
  2580 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2581 particularly convenient to organize independent functional
  2582 computations.  The concept of "synchronized variables" provides a
  2583 higher-order interface for components with shared state, avoiding the
  2584 delicate details of mutexes and condition variables.  (Requires
  2585 Poly/ML 5.2.1 or later.)
  2586 
  2587 * ML bindings produced via Isar commands are stored within the Isar
  2588 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2589 become thread-safe and work with undo as expected (concerning
  2590 top-level bindings, not side-effects on global references).
  2591 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2592 compiler at runtime; really global bindings need to be given outside a
  2593 theory.  (Requires Poly/ML 5.2 or later.)
  2594 
  2595 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2596 context.  Top-level ML bindings are stored within the proof context in
  2597 a purely sequential fashion, disregarding the nested proof structure.
  2598 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2599 proof.  (Requires Poly/ML 5.2 or later.)
  2600 
  2601 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2602 and Method.setup, as well as Isar commands 'attribute_setup' and
  2603 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2604 existing code accordingly, or use plain 'setup' together with old
  2605 Method.add_method.
  2606 
  2607 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2608 to 'a -> thm, while results are always tagged with an authentic oracle
  2609 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2610 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2611 accordingly.  Note that extra performance may be gained by producing
  2612 the cterm carefully, avoiding slow Thm.cterm_of.
  2613 
  2614 * Simplified interface for defining document antiquotations via
  2615 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2616 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2617 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2618 examples.
  2619 
  2620 * More systematic treatment of long names, abstract name bindings, and
  2621 name space operations.  Basic operations on qualified names have been
  2622 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2623 Long_Name.append.  Old type bstring has been mostly replaced by
  2624 abstract type binding (see structure Binding), which supports precise
  2625 qualification by packages and local theory targets, as well as proper
  2626 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2627 bstring values into Binding.name, or better pass through abstract
  2628 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2629 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2630 
  2631 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2632 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2633 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2634 
  2635 * Disposed old type and term read functions (Sign.read_def_typ,
  2636 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2637 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2638 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2639 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2640 resort for legacy applications.
  2641 
  2642 * Disposed old declarations, tactics, tactic combinators that refer to
  2643 the simpset or claset of an implicit theory (such as Addsimps,
  2644 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2645 embedded ML text, or local_simpset_of with a proper context passed as
  2646 explicit runtime argument.
  2647 
  2648 * Rules and tactics that read instantiations (read_instantiate,
  2649 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2650 context, which is required for parsing and type-checking.  Moreover,
  2651 the variables are specified as plain indexnames, not string encodings
  2652 thereof.  INCOMPATIBILITY.
  2653 
  2654 * Generic Toplevel.add_hook interface allows to analyze the result of
  2655 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2656 for theorem dependency output of transactions resulting in a new
  2657 theory state.
  2658 
  2659 * ML antiquotations: block-structured compilation context indicated by
  2660 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2661 
  2662   @{binding name}                         - basic name binding
  2663   @{let ?pat = term}                      - term abbreviation (HO matching)
  2664   @{note name = fact}                     - fact abbreviation
  2665   @{thm fact}                             - singleton fact (with attributes)
  2666   @{thms fact}                            - general fact (with attributes)
  2667   @{lemma prop by method}                 - singleton goal
  2668   @{lemma prop by meth1 meth2}            - singleton goal
  2669   @{lemma prop1 ... propN by method}      - general goal
  2670   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2671   @{lemma (open) ...}                     - open derivation
  2672 
  2673 
  2674 *** System ***
  2675 
  2676 * The Isabelle "emacs" tool provides a specific interface to invoke
  2677 Proof General / Emacs, with more explicit failure if that is not
  2678 installed (the old isabelle-interface script silently falls back on
  2679 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2680 installation location of the Proof General distribution.
  2681 
  2682 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2683 the Isabelle process into a JVM/Scala application.  See
  2684 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2685 process wrapper has been discontinued.)
  2686 
  2687 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2688 
  2689 * Various status messages (with exact source position information) are
  2690 emitted, if proper markup print mode is enabled.  This allows
  2691 user-interface components to provide detailed feedback on internal
  2692 prover operations.
  2693 
  2694 
  2695 
  2696 New in Isabelle2008 (June 2008)
  2697 -------------------------------
  2698 
  2699 *** General ***
  2700 
  2701 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2702 and updated, with formally checked references as hyperlinks.
  2703 
  2704 * Theory loader: use_thy (and similar operations) no longer set the
  2705 implicit ML context, which was occasionally hard to predict and in
  2706 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2707 provides a proper context already.
  2708 
  2709 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2710 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2711 'use' within a theory file will do the job.
  2712 
  2713 * Name space merge now observes canonical order, i.e. the second space
  2714 is inserted into the first one, while existing entries in the first
  2715 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2716 swap theory imports.
  2717 
  2718 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2719 INCOMPATIBILITY in identifier syntax etc.
  2720 
  2721 * Outer syntax: string tokens no longer admit escaped white space,
  2722 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2723 white space without escapes.
  2724 
  2725 * Outer syntax: string tokens may contain arbitrary character codes
  2726 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2727 "foo_bar".
  2728 
  2729 
  2730 *** Pure ***
  2731 
  2732 * Context-dependent token translations.  Default setup reverts locally
  2733 fixed variables, and adds hilite markup for undeclared frees.
  2734 
  2735 * Unused theorems can be found using the new command 'unused_thms'.
  2736 There are three ways of invoking it:
  2737 
  2738 (1) unused_thms
  2739      Only finds unused theorems in the current theory.
  2740 
  2741 (2) unused_thms thy_1 ... thy_n -
  2742      Finds unused theorems in the current theory and all of its ancestors,
  2743      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2744 
  2745 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2746      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2747      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2748      their ancestors.
  2749 
  2750 In order to increase the readability of the list produced by
  2751 unused_thms, theorems that have been created by a particular instance
  2752 of a theory command such as 'inductive' or 'function' are considered
  2753 to belong to the same "group", meaning that if at least one theorem in
  2754 this group is used, the other theorems in the same group are no longer
  2755 reported as unused.  Moreover, if all theorems in the group are
  2756 unused, only one theorem in the group is displayed.
  2757 
  2758 Note that proof objects have to be switched on in order for
  2759 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2760 usually the case when using Proof General with the default settings).
  2761 
  2762 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2763 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2764 duplicate fact bindings, or even accidental fact duplications.  Note
  2765 that tools may maintain dynamically scoped facts systematically, using
  2766 PureThy.add_thms_dynamic.
  2767 
  2768 * Command 'hide' now allows to hide from "fact" name space as well.
  2769 
  2770 * Eliminated destructive theorem database, simpset, claset, and
  2771 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2772 update of theories within ML code.
  2773 
  2774 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2775 INCOMPATIBILITY, object-logics depending on former Pure require
  2776 additional setup PureThy.old_appl_syntax_setup; object-logics
  2777 depending on former CPure need to refer to Pure.
  2778 
  2779 * Commands 'use' and 'ML' are now purely functional, operating on
  2780 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2781 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2782 INCOMPATIBILITY.
  2783 
  2784 * Command 'setup': discontinued implicit version with ML reference.
  2785 
  2786 * Instantiation target allows for simultaneous specification of class
  2787 instance operations together with an instantiation proof.
  2788 Type-checking phase allows to refer to class operations uniformly.
  2789 See src/HOL/Complex/Complex.thy for an Isar example and
  2790 src/HOL/Library/Eval.thy for an ML example.
  2791 
  2792 * Indexing of literal facts: be more serious about including only
  2793 facts from the visible specification/proof context, but not the
  2794 background context (locale etc.).  Affects `prop` notation and method
  2795 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2796 situations.
  2797 
  2798 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2799 "(open)" option, which used to expose internal bound variables to the
  2800 proof text.
  2801 
  2802 * Isar statements: removed obsolete case "rule_context".
  2803 INCOMPATIBILITY, better use explicit fixes/assumes.
  2804 
  2805 * Locale proofs: default proof step now includes 'unfold_locales';
  2806 hence 'proof' without argument may be used to unfold locale
  2807 predicates.
  2808 
  2809 
  2810 *** Document preparation ***
  2811 
  2812 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2813 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2814 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2815 spot); renamed link color from "darkblue" to "linkcolor" (default
  2816 value unchanged, can be redefined via \definecolor); no longer sets
  2817 "a4paper" option (unnecessary or even intrusive).
  2818 
  2819 * Antiquotation @{lemma A method} proves proposition A by the given
  2820 method (either a method name or a method name plus (optional) method
  2821 arguments in parentheses) and prints A just like @{prop A}.
  2822 
  2823 
  2824 *** HOL ***
  2825 
  2826 * New primrec package.  Specification syntax conforms in style to
  2827 definition/function/....  No separate induction rule is provided.  The
  2828 "primrec" command distinguishes old-style and new-style specifications
  2829 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2830 When adjusting theories, beware: constants stemming from new-style
  2831 primrec specifications have authentic syntax.
  2832 
  2833 * Metis prover is now an order of magnitude faster, and also works
  2834 with multithreading.
  2835 
  2836 * Metis: the maximum number of clauses that can be produced from a
  2837 theorem is now given by the attribute max_clauses.  Theorems that
  2838 exceed this number are ignored, with a warning printed.
  2839 
  2840 * Sledgehammer no longer produces structured proofs by default. To
  2841 enable, declare [[sledgehammer_full = true]].  Attributes
  2842 reconstruction_modulus, reconstruction_sorts renamed
  2843 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2844 
  2845 * Method "induct_scheme" derives user-specified induction rules
  2846 from well-founded induction and completeness of patterns. This factors
  2847 out some operations that are done internally by the function package
  2848 and makes them available separately.  See
  2849 src/HOL/ex/Induction_Scheme.thy for examples.
  2850 
  2851 * More flexible generation of measure functions for termination
  2852 proofs: Measure functions can be declared by proving a rule of the
  2853 form "is_measure f" and giving it the [measure_function] attribute.
  2854 The "is_measure" predicate is logically meaningless (always true), and
  2855 just guides the heuristic.  To find suitable measure functions, the
  2856 termination prover sets up the goal "is_measure ?f" of the appropriate
  2857 type and generates all solutions by prolog-style backwards proof using
  2858 the declared rules.
  2859 
  2860 This setup also deals with rules like 
  2861 
  2862   "is_measure f ==> is_measure (list_size f)"
  2863 
  2864 which accommodates nested datatypes that recurse through lists.
  2865 Similar rules are predeclared for products and option types.
  2866 
  2867 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2868 
  2869   INCOMPATIBILITIES:
  2870 
  2871   - Definitions of overloaded constants on sets have to be replaced by
  2872     definitions on => and bool.
  2873 
  2874   - Some definitions of overloaded operators on sets can now be proved
  2875     using the definitions of the operators on => and bool.  Therefore,
  2876     the following theorems have been renamed:
  2877 
  2878       subset_def   -> subset_eq
  2879       psubset_def  -> psubset_eq
  2880       set_diff_def -> set_diff_eq
  2881       Compl_def    -> Compl_eq
  2882       Sup_set_def  -> Sup_set_eq
  2883       Inf_set_def  -> Inf_set_eq
  2884       sup_set_def  -> sup_set_eq
  2885       inf_set_def  -> inf_set_eq
  2886 
  2887   - Due to the incompleteness of the HO unification algorithm, some
  2888     rules such as subst may require manual instantiation, if some of
  2889     the unknowns in the rule is a set.
  2890 
  2891   - Higher order unification and forward proofs:
  2892     The proof pattern
  2893 
  2894       have "P (S::'a set)" <...>
  2895       then have "EX S. P S" ..
  2896 
  2897     no longer works (due to the incompleteness of the HO unification
  2898     algorithm) and must be replaced by the pattern
  2899 
  2900       have "EX S. P S"
  2901       proof
  2902         show "P S" <...>
  2903       qed
  2904 
  2905   - Calculational reasoning with subst (or similar rules):
  2906     The proof pattern
  2907 
  2908       have "P (S::'a set)" <...>
  2909       also have "S = T" <...>
  2910       finally have "P T" .
  2911 
  2912     no longer works (for similar reasons as the previous example) and
  2913     must be replaced by something like
  2914 
  2915       have "P (S::'a set)" <...>
  2916       moreover have "S = T" <...>
  2917       ultimately have "P T" by simp
  2918 
  2919   - Tactics or packages written in ML code:
  2920     Code performing pattern matching on types via
  2921 
  2922       Type ("set", [T]) => ...
  2923 
  2924     must be rewritten. Moreover, functions like strip_type or
  2925     binder_types no longer return the right value when applied to a
  2926     type of the form
  2927 
  2928       T1 => ... => Tn => U => bool
  2929 
  2930     rather than
  2931 
  2932       T1 => ... => Tn => U set
  2933 
  2934 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2935 Wellfounded_Relations to theory Wellfounded.
  2936 
  2937 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2938 
  2939 * Class finite no longer treats UNIV as class parameter.  Use class
  2940 enum from theory Library/Enum instead to achieve a similar effect.
  2941 INCOMPATIBILITY.
  2942 
  2943 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2944 and "Cons".  INCOMPATIBILITY.
  2945 
  2946 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2947 Potential INCOMPATIBILITY.
  2948 
  2949 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2950 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2951 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2952 
  2953 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2954 the same name in theory Orderings:
  2955 
  2956   less_trans
  2957   less_linear
  2958   le_imp_less_or_eq
  2959   le_less_trans
  2960   less_le_trans
  2961   less_not_sym
  2962   less_asym
  2963 
  2964 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2965 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2966 and different variable names.
  2967 
  2968 * Library/Option_ord.thy: Canonical order on option type.
  2969 
  2970 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2971 finite maps.
  2972 
  2973 * Library/Countable.thy: Type class for countable types.
  2974 
  2975 * Theory Int: The representation of numerals has changed.  The infix
  2976 operator BIT and the bit datatype with constructors B0 and B1 have
  2977 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2978 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2979 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2980 accordingly.
  2981 
  2982 * Theory Nat: definition of <= and < on natural numbers no longer
  2983 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2984 le_def and less_def have disappeared.  Consider lemmas not_less
  2985 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2986 
  2987 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2988 (whose purpose mainly is for various fold_set functionals) have been
  2989 abandoned in favor of the existing algebraic classes
  2990 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2991 lower_semilattice (resp. upper_semilattice) and linorder.
  2992 INCOMPATIBILITY.
  2993 
  2994 * Theory Transitive_Closure: induct and cases rules now declare proper
  2995 case_names ("base" and "step").  INCOMPATIBILITY.
  2996 
  2997 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2998 lattices.  The form set-specific version is available as
  2999 Inductive.lfp_ordinal_induct_set.
  3000 
  3001 * Renamed theorems "power.simps" to "power_int.simps".
  3002 INCOMPATIBILITY.
  3003 
  3004 * Class semiring_div provides basic abstract properties of semirings
  3005 with division and modulo operations.  Subsumes former class dvd_mod.
  3006 
  3007 * Merged theories IntDef, Numeral and IntArith into unified theory
  3008 Int.  INCOMPATIBILITY.
  3009 
  3010 * Theory Library/Code_Index: type "index" now represents natural
  3011 numbers rather than integers.  INCOMPATIBILITY.
  3012 
  3013 * New class "uminus" with operation "uminus" (split of from class
  3014 "minus" which now only has operation "minus", binary).
  3015 INCOMPATIBILITY.
  3016 
  3017 * Constants "card", "internal_split", "option_map" now with authentic
  3018 syntax.  INCOMPATIBILITY.
  3019 
  3020 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3021 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3022 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3023 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3024 Sup_set_def, le_def, less_def, option_map_def now with object
  3025 equality.  INCOMPATIBILITY.
  3026 
  3027 * Records. Removed K_record, and replaced it by pure lambda term
  3028 %x. c. The simplifier setup is now more robust against eta expansion.
  3029 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3030 
  3031 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3032 
  3033 * Library/ListVector: new theory of arithmetic vector operations.
  3034 
  3035 * Library/Order_Relation: new theory of various orderings as sets of
  3036 pairs.  Defines preorders, partial orders, linear orders and
  3037 well-orders on sets and on types.
  3038 
  3039 
  3040 *** ZF ***
  3041 
  3042 * Renamed some theories to allow to loading both ZF and HOL in the
  3043 same session:
  3044 
  3045   Datatype  -> Datatype_ZF
  3046   Inductive -> Inductive_ZF
  3047   Int       -> Int_ZF
  3048   IntDiv    -> IntDiv_ZF
  3049   Nat       -> Nat_ZF
  3050   List      -> List_ZF
  3051   Main      -> Main_ZF
  3052 
  3053 INCOMPATIBILITY: ZF theories that import individual theories below
  3054 Main might need to be adapted.  Regular theory Main is still
  3055 available, as trivial extension of Main_ZF.
  3056 
  3057 
  3058 *** ML ***
  3059 
  3060 * ML within Isar: antiquotation @{const name} or @{const
  3061 name(typargs)} produces statically-checked Const term.
  3062 
  3063 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3064 (of the same name).  Removed obsolete print command.
  3065 
  3066 * Removed obsolete "use_legacy_bindings" function.
  3067 
  3068 * The ``print mode'' is now a thread-local value derived from a global
  3069 template (the former print_mode reference), thus access becomes
  3070 non-critical.  The global print_mode reference is for session
  3071 management only; user-code should use print_mode_value,
  3072 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3073 
  3074 * Functions system/system_out provide a robust way to invoke external
  3075 shell commands, with propagation of interrupts (requires Poly/ML
  3076 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3077 
  3078 
  3079 *** System ***
  3080 
  3081 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3082 in accordance with Proof General 3.7, which prefers GNU emacs.
  3083 
  3084 * isatool tty runs Isabelle process with plain tty interaction;
  3085 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3086 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3087 
  3088 * isatool browser now works with Cygwin as well, using general
  3089 "javapath" function defined in Isabelle process environment.
  3090 
  3091 * YXML notation provides a simple and efficient alternative to
  3092 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3093 isatool yxml as described in the Isabelle system manual.
  3094 
  3095 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3096 provides general wrapper for managing an Isabelle process in a robust
  3097 fashion, with ``cooked'' output from stdin/stderr.
  3098 
  3099 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3100 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3101 
  3102 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3103 way of changing the user's settings is via
  3104 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3105 script.
  3106 
  3107 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3108 cores of the underlying machine, which is a good starting point for
  3109 optimal performance tuning.  The corresponding usedir option -M allows
  3110 "max" as an alias for "0".  WARNING: does not work on certain versions
  3111 of Mac OS (with Poly/ML 5.1).
  3112 
  3113 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3114 adverse effect of Isabelle flooding interactive front-ends (notably
  3115 ProofGeneral / XEmacs).
  3116 
  3117 
  3118 
  3119 New in Isabelle2007 (November 2007)
  3120 -----------------------------------
  3121 
  3122 *** General ***
  3123 
  3124 * More uniform information about legacy features, notably a
  3125 warning/error of "Legacy feature: ...", depending on the state of the
  3126 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3127 legacy features will disappear eventually.
  3128 
  3129 * Theory syntax: the header format ``theory A = B + C:'' has been
  3130 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3131 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3132 
  3133 * Theory syntax: the old non-Isar theory file format has been
  3134 discontinued altogether.  Note that ML proof scripts may still be used
  3135 with Isar theories; migration is usually quite simple with the ML
  3136 function use_legacy_bindings.  INCOMPATIBILITY.
  3137 
  3138 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3139 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3140 quotes.
  3141 
  3142 * Theory loader: be more serious about observing the static theory
  3143 header specifications (including optional directories), but not the
  3144 accidental file locations of previously successful loads.  The strict
  3145 update policy of former update_thy is now already performed by
  3146 use_thy, so the former has been removed; use_thys updates several
  3147 theories simultaneously, just as 'imports' within a theory header
  3148 specification, but without merging the results.  Potential
  3149 INCOMPATIBILITY: may need to refine theory headers and commands
  3150 ROOT.ML which depend on load order.
  3151 
  3152 * Theory loader: optional support for content-based file
  3153 identification, instead of the traditional scheme of full physical
  3154 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3155 (cf. the system manual).  The new scheme allows to work with
  3156 non-finished theories in persistent session images, such that source
  3157 files may be moved later on without requiring reloads.
  3158 
  3159 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3160 file (with the same base name as the theory) are considered a legacy
  3161 feature, which will disappear eventually. Even now, the theory loader
  3162 no longer maintains dependencies on such files.
  3163 
  3164 * Syntax: the scope for resolving ambiguities via type-inference is
  3165 now limited to individual terms, instead of whole simultaneous
  3166 specifications as before. This greatly reduces the complexity of the
  3167 syntax module and improves flexibility by separating parsing and
  3168 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3169 'fixes' etc.) are required in rare situations.
  3170 
  3171 * Syntax: constants introduced by new-style packages ('definition',
  3172 'abbreviation' etc.) are passed through the syntax module in
  3173 ``authentic mode''. This means that associated mixfix annotations
  3174 really stick to such constants, independently of potential name space
  3175 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3176 trees are represented slightly differently, may need to adapt syntax
  3177 translations accordingly. Use CONST marker in 'translations' and
  3178 @{const_syntax} antiquotation in 'parse_translation' etc.
  3179 
  3180 * Legacy goal package: reduced interface to the bare minimum required
  3181 to keep existing proof scripts running.  Most other user-level
  3182 functions are now part of the OldGoals structure, which is *not* open
  3183 by default (consider isatool expandshort before open OldGoals).
  3184 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3185 these tend to cause confusion about the actual goal (!) context being
  3186 used here, which is not necessarily the same as the_context().
  3187 
  3188 * Command 'find_theorems': supports "*" wild-card in "name:"
  3189 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3190 support a specific search form (see ProofGeneral/CHANGES).
  3191 
  3192 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3193 by default, which means that "prems" (and also "fixed variables") are
  3194 suppressed from proof state output.  Note that the ProofGeneral
  3195 settings mechanism allows to change and save options persistently, but
  3196 older versions of Isabelle will fail to start up if a negative prems
  3197 limit is imposed.
  3198 
  3199 * Local theory targets may be specified by non-nested blocks of
  3200 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3201 contain definitions, theorems etc., including any derived mechanism
  3202 that has been implemented on top of these primitives.  This concept
  3203 generalizes the existing ``theorem (in ...)'' towards more versatility
  3204 and scalability.
  3205 
  3206 * Proof General interface: proper undo of final 'end' command;
  3207 discontinued Isabelle/classic mode (ML proof scripts).
  3208 
  3209 
  3210 *** Document preparation ***
  3211 
  3212 * Added antiquotation @{theory name} which prints the given name,
  3213 after checking that it refers to a valid ancestor theory in the
  3214 current context.
  3215 
  3216 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3217 check the given source text as ML type/structure, printing verbatim.
  3218 
  3219 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3220 "c args == rhs" given in the current context.  (Any number of
  3221 arguments may be given on the LHS.)
  3222 
  3223 
  3224 *** Pure ***
  3225 
  3226 * The 'class' package offers a combination of axclass and locale to
  3227 achieve Haskell-like type classes in Isabelle.  Definitions and
  3228 theorems within a class context produce both relative results (with
  3229 implicit parameters according to the locale context), and polymorphic
  3230 constants with qualified polymorphism (according to the class
  3231 context).  Within the body context of a 'class' target, a separate
  3232 syntax layer ("user space type system") takes care of converting
  3233 between global polymorphic consts and internal locale representation.
  3234 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3235 "isatool doc classes" provides a tutorial.
  3236 
  3237 * Generic code generator framework allows to generate executable
  3238 code for ML and Haskell (including Isabelle classes).  A short usage
  3239 sketch:
  3240 
  3241     internal compilation:
  3242         export_code <list of constants (term syntax)> in SML
  3243     writing SML code to a file:
  3244         export_code <list of constants (term syntax)> in SML <filename>
  3245     writing OCaml code to a file:
  3246         export_code <list of constants (term syntax)> in OCaml <filename>
  3247     writing Haskell code to a bunch of files:
  3248         export_code <list of constants (term syntax)> in Haskell <filename>
  3249 
  3250     evaluating closed propositions to True/False using code generation:
  3251         method ``eval''
  3252 
  3253 Reasonable default setup of framework in HOL.
  3254 
  3255 Theorem attributs for selecting and transforming function equations theorems:
  3256 
  3257     [code fun]:        select a theorem as function equation for a specific constant
  3258     [code fun del]:    deselect a theorem as function equation for a specific constant
  3259     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3260     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3261 
  3262 User-defined serializations (target in {SML, OCaml, Haskell}):
  3263 
  3264     code_const <and-list of constants (term syntax)>
  3265       {(target) <and-list of const target syntax>}+
  3266 
  3267     code_type <and-list of type constructors>
  3268       {(target) <and-list of type target syntax>}+
  3269 
  3270     code_instance <and-list of instances>
  3271       {(target)}+
  3272         where instance ::= <type constructor> :: <class>
  3273 
  3274     code_class <and_list of classes>
  3275       {(target) <and-list of class target syntax>}+
  3276         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3277 
  3278 code_instance and code_class only are effective to target Haskell.
  3279 
  3280 For example usage see src/HOL/ex/Codegenerator.thy and
  3281 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3282 generation from Isabelle/HOL theories is available via "isatool doc
  3283 codegen".
  3284 
  3285 * Code generator: consts in 'consts_code' Isar commands are now
  3286 referred to by usual term syntax (including optional type
  3287 annotations).
  3288 
  3289 * Command 'no_translations' removes translation rules from theory
  3290 syntax.
  3291 
  3292 * Overloaded definitions are now actually checked for acyclic
  3293 dependencies.  The overloading scheme is slightly more general than
  3294 that of Haskell98, although Isabelle does not demand an exact
  3295 correspondence to type class and instance declarations.
  3296 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3297 exotic versions of overloading -- at the discretion of the user!
  3298 
  3299 Polymorphic constants are represented via type arguments, i.e. the
  3300 instantiation that matches an instance against the most general
  3301 declaration given in the signature.  For example, with the declaration
  3302 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3303 as c(nat).  Overloading is essentially simultaneous structural
  3304 recursion over such type arguments.  Incomplete specification patterns
  3305 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3306 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3307 Command 'print_theory' outputs the normalized system of recursive
  3308 equations, see section "definitions".
  3309 
  3310 * Configuration options are maintained within the theory or proof
  3311 context (with name and type bool/int/string), providing a very simple
  3312 interface to a poor-man's version of general context data.  Tools may
  3313 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3314 these values using Config.get etc.  Users may change options via an
  3315 associated attribute of the same name.  This form of context
  3316 declaration works particularly well with commands 'declare' or
  3317 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3318 very easy to avoid global references, which would not observe Isar
  3319 toplevel undo/redo and fail to work with multithreading.
  3320 
  3321 Various global ML references of Pure and HOL have been turned into
  3322 configuration options:
  3323 
  3324   Unify.search_bound		unify_search_bound
  3325   Unify.trace_bound		unify_trace_bound
  3326   Unify.trace_simp		unify_trace_simp
  3327   Unify.trace_types		unify_trace_types
  3328   Simplifier.simp_depth_limit	simp_depth_limit
  3329   Blast.depth_limit		blast_depth_limit
  3330   DatatypeProp.dtK		datatype_distinctness_limit
  3331   fast_arith_neq_limit  	fast_arith_neq_limit
  3332   fast_arith_split_limit	fast_arith_split_limit
  3333 
  3334 * Named collections of theorems may be easily installed as context
  3335 data using the functor NamedThmsFun (see also
  3336 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3337 attributes; there is also a toplevel print command.  This facility is
  3338 just a common case of general context data, which is the preferred way
  3339 for anything more complex than just a list of facts in canonical
  3340 order.
  3341 
  3342 * Isar: command 'declaration' augments a local theory by generic
  3343 declaration functions written in ML.  This enables arbitrary content
  3344 being added to the context, depending on a morphism that tells the
  3345 difference of the original declaration context wrt. the application
  3346 context encountered later on.
  3347 
  3348 * Isar: proper interfaces for simplification procedures.  Command
  3349 'simproc_setup' declares named simprocs (with match patterns, and body
  3350 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3351 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3352 
  3353 * Isar: an extra pair of brackets around attribute declarations
  3354 abbreviates a theorem reference involving an internal dummy fact,
  3355 which will be ignored later --- only the effect of the attribute on
  3356 the background context will persist.  This form of in-place
  3357 declarations is particularly useful with commands like 'declare' and
  3358 'using', for example ``have A using [[simproc a]] by simp''.
  3359 
  3360 * Isar: method "assumption" (and implicit closing of subproofs) now
  3361 takes simple non-atomic goal assumptions into account: after applying
  3362 an assumption as a rule the resulting subgoals are solved by atomic
  3363 assumption steps.  This is particularly useful to finish 'obtain'
  3364 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3365 without referring to the original premise "!!x. P x ==> thesis" in the
  3366 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3367 more permissive.
  3368 
  3369 * Isar: implicit use of prems from the Isar proof context is
  3370 considered a legacy feature.  Common applications like ``have A .''
  3371 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3372 referencing facts explicitly here improves readability and
  3373 maintainability of proof texts.
  3374 
  3375 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3376 the obtained context from the course of reasoning!  For example:
  3377 
  3378   assume "EX x y. A x & B y"   -- "any previous fact"
  3379   then guess x and y by clarify
  3380 
  3381 This technique is potentially adventurous, depending on the facts and
  3382 proof tools being involved here.
  3383 
  3384 * Isar: known facts from the proof context may be specified as literal
  3385 propositions, using ASCII back-quote syntax.  This works wherever
  3386 named facts used to be allowed so far, in proof commands, proof
  3387 methods, attributes etc.  Literal facts are retrieved from the context
  3388 according to unification of type and term parameters.  For example,
  3389 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3390 theorems in the current context, then these are valid literal facts:
  3391 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3392 
  3393 There is also a proof method "fact" which does the same composition
  3394 for explicit goal states, e.g. the following proof texts coincide with
  3395 certain special cases of literal facts:
  3396 
  3397   have "A" by fact                 ==  note `A`
  3398   have "A ==> B" by fact           ==  note `A ==> B`
  3399   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3400   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3401 
  3402 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3403 outer syntax.  Thus symbolic identifiers may be used without
  3404 additional white space in declarations like this: ``assume *: A''.
  3405 
  3406 * Isar: 'print_facts' prints all local facts of the current context,
  3407 both named and unnamed ones.
  3408 
  3409 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3410 
  3411   def x == "t" and y == "u"
  3412 
  3413 * Isar: added command 'unfolding', which is structurally similar to
  3414 'using', but affects both the goal state and facts by unfolding given
  3415 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3416 'unfolded' attribute may be replaced by first-class proof text.
  3417 
  3418 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3419 and command 'unfolding' now all support object-level equalities
  3420 (potentially conditional).  The underlying notion of rewrite rule is
  3421 analogous to the 'rule_format' attribute, but *not* that of the
  3422 Simplifier (which is usually more generous).
  3423 
  3424 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3425 premises of a theorem by n. Useful in conjunction with drule.
  3426 
  3427 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3428 method expression within a sandbox consisting of the first N
  3429 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3430 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3431 simplifies all new goals that emerge from applying rule foo to the
  3432 originally first one.
  3433 
  3434 * Isar: schematic goals are no longer restricted to higher-order
  3435 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3436 expected.
  3437 
  3438 * Isar: the conclusion of a long theorem statement is now either
  3439 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3440 (essentially a disjunction of cases with local parameters and
  3441 assumptions).  The latter allows to express general elimination rules
  3442 adequately; in this notation common elimination rules look like this:
  3443 
  3444   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3445     assumes "EX x. P x"
  3446     obtains x where "P x"
  3447 
  3448   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3449     assumes "A & B"
  3450     obtains A and B
  3451 
  3452   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3453     assumes "A | B"
  3454     obtains
  3455       A
  3456     | B
  3457 
  3458 The subsequent classical rules even refer to the formal "thesis"
  3459 explicitly:
  3460 
  3461   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3462     obtains "~ thesis"
  3463 
  3464   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3465     obtains "thesis ==> something"
  3466 
  3467 The actual proof of an 'obtains' statement is analogous to that of the
  3468 Isar proof element 'obtain', only that there may be several cases.
  3469 Optional case names may be specified in parentheses; these will be
  3470 available both in the present proof and as annotations in the
  3471 resulting rule, for later use with the 'cases' method (cf. attribute
  3472 case_names).
  3473 
  3474 * Isar: the assumptions of a long theorem statement are available as
  3475 "assms" fact in the proof context.  This is more appropriate than the
  3476 (historical) "prems", which refers to all assumptions of the current
  3477 context, including those from the target locale, proof body etc.
  3478 
  3479 * Isar: 'print_statement' prints theorems from the current theory or
  3480 proof context in long statement form, according to the syntax of a
  3481 top-level lemma.
  3482 
  3483 * Isar: 'obtain' takes an optional case name for the local context
  3484 introduction rule (default "that").
  3485 
  3486 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3487 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3488 to occur.
  3489 
  3490 * Pure: syntax "CONST name" produces a fully internalized constant
  3491 according to the current context.  This is particularly useful for
  3492 syntax translations that should refer to internal constant
  3493 representations independently of name spaces.
  3494 
  3495 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3496 instead of "FOO ". This allows multiple binder declarations to coexist
  3497 in the same context.  INCOMPATIBILITY.
  3498 
  3499 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3500 primitive that also works in a locale context (both for constants and
  3501 fixed variables). Type declaration and internal syntactic representation
  3502 of given constants retrieved from the context. Likewise, the
  3503 'no_notation' command allows to remove given syntax annotations from the
  3504 current context.
  3505 
  3506 * Isar/locales: new derived specification elements 'axiomatization',
  3507 'definition', 'abbreviation', which support type-inference, admit
  3508 object-level specifications (equality, equivalence).  See also the
  3509 isar-ref manual.  Examples:
  3510 
  3511   axiomatization
  3512     eq  (infix "===" 50) where
  3513     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3514 
  3515   definition "f x y = x + y + 1"
  3516   definition g where "g x = f x x"
  3517 
  3518   abbreviation
  3519     neq  (infix "=!=" 50) where
  3520     "x =!= y == ~ (x === y)"
  3521 
  3522 These specifications may be also used in a locale context.  Then the
  3523 constants being introduced depend on certain fixed parameters, and the
  3524 constant name is qualified by the locale base name.  An internal
  3525 abbreviation takes care for convenient input and output, making the
  3526 parameters implicit and using the original short name.  See also
  3527 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3528 entities from a monomorphic theory.
  3529 
  3530 Presently, abbreviations are only available 'in' a target locale, but
  3531 not inherited by general import expressions.  Also note that
  3532 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3533 'translations' in common applications.  The "no_abbrevs" print mode
  3534 prevents folding of abbreviations in term output.
  3535 
  3536 Concrete syntax is attached to specified constants in internal form,
  3537 independently of name spaces.  The parse tree representation is
  3538 slightly different -- use 'notation' instead of raw 'syntax', and
  3539 'translations' with explicit "CONST" markup to accommodate this.
  3540 
  3541 * Pure/Isar: unified syntax for new-style specification mechanisms
  3542 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3543 full type inference and dummy patterns ("_").  For example:
  3544 
  3545   definition "K x _ = x"
  3546 
  3547   inductive conj for A B
  3548   where "A ==> B ==> conj A B"
  3549 
  3550 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3551 the current context.  Print mode "no_abbrevs" prevents inversion of
  3552 abbreviations on output.
  3553 
  3554 * Isar/locales: improved parameter handling: use of locales "var" and
  3555 "struct" no longer necessary; - parameter renamings are no longer
  3556 required to be injective.  For example, this allows to define
  3557 endomorphisms as locale endom = homom mult mult h.
  3558 
  3559 * Isar/locales: changed the way locales with predicates are defined.
  3560 Instead of accumulating the specification, the imported expression is
  3561 now an interpretation.  INCOMPATIBILITY: different normal form of
  3562 locale expressions.  In particular, in interpretations of locales with
  3563 predicates, goals repesenting already interpreted fragments are not
  3564 removed automatically.  Use methods `intro_locales' and
  3565 `unfold_locales'; see below.
  3566 
  3567 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3568 provide backward reasoning on locales predicates.  The methods are
  3569 aware of interpretations and discharge corresponding goals.
  3570 `intro_locales' is less aggressive then `unfold_locales' and does not
  3571 unfold predicates to assumptions.
  3572 
  3573 * Isar/locales: the order in which locale fragments are accumulated
  3574 has changed.  This enables to override declarations from fragments due
  3575 to interpretations -- for example, unwanted simp rules.
  3576 
  3577 * Isar/locales: interpretation in theories and proof contexts has been
  3578 extended.  One may now specify (and prove) equations, which are
  3579 unfolded in interpreted theorems.  This is useful for replacing
  3580 defined concepts (constants depending on locale parameters) by
  3581 concepts already existing in the target context.  Example:
  3582 
  3583   interpretation partial_order ["op <= :: [int, int] => bool"]
  3584     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3585 
  3586 Typically, the constant `partial_order.less' is created by a
  3587 definition specification element in the context of locale
  3588 partial_order.
  3589 
  3590 * Method "induct": improved internal context management to support
  3591 local fixes and defines on-the-fly. Thus explicit meta-level
  3592 connectives !!  and ==> are rarely required anymore in inductive goals
  3593 (using object-logic connectives for this purpose has been long
  3594 obsolete anyway). Common proof patterns are explained in
  3595 src/HOL/Induct/Common_Patterns.thy, see also
  3596 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3597 examples.
  3598 
  3599 * Method "induct": improved handling of simultaneous goals. Instead of
  3600 introducing object-level conjunction, the statement is now split into
  3601 several conclusions, while the corresponding symbolic cases are nested
  3602 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3603 see src/HOL/Induct/Common_Patterns.thy, for example.
  3604 
  3605 * Method "induct": mutual induction rules are now specified as a list
  3606 of rule sharing the same induction cases. HOL packages usually provide
  3607 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3608 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3609 mutual induction rules differently, i.e. like this:
  3610 
  3611   (induct rule: foo_bar.inducts)
  3612   (induct set: foo bar)
  3613   (induct pred: foo bar)
  3614   (induct type: foo bar)
  3615 
  3616 The ML function ProjectRule.projections turns old-style rules into the
  3617 new format.
  3618 
  3619 * Method "coinduct": dual of induction, see
  3620 src/HOL/Library/Coinductive_List.thy for various examples.
  3621 
  3622 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3623 considered a legacy feature.
  3624 
  3625 * Attribute "symmetric" produces result with standardized schematic
  3626 variables (index 0).  Potential INCOMPATIBILITY.
  3627 
  3628 * Simplifier: by default the simplifier trace only shows top level
  3629 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3630 default. Thus there is less danger of being flooded by the trace. The
  3631 trace indicates where parts have been suppressed.
  3632   
  3633 * Provers/classical: removed obsolete classical version of elim_format
  3634 attribute; classical elim/dest rules are now treated uniformly when
  3635 manipulating the claset.
  3636 
  3637 * Provers/classical: stricter checks to ensure that supplied intro,
  3638 dest and elim rules are well-formed; dest and elim rules must have at
  3639 least one premise.
  3640 
  3641 * Provers/classical: attributes dest/elim/intro take an optional
  3642 weight argument for the rule (just as the Pure versions).  Weights are
  3643 ignored by automated tools, but determine the search order of single
  3644 rule steps.
  3645 
  3646 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3647 where the body does not mention the bound variable.  Note that dummy
  3648 patterns implicitly depend on their context of bounds, which makes
  3649 "{_. _}" match any set comprehension as expected.  Potential
  3650 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3651 constant "_idtdummy" in the binding position.
  3652 
  3653 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3654 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3655 for example "A -> B" => "Pi A (%_. B)".
  3656 
  3657 * Pure: 'class_deps' command visualizes the subclass relation, using
  3658 the graph browser tool.
  3659 
  3660 * Pure: 'print_theory' now suppresses certain internal declarations by
  3661 default; use '!' option for full details.
  3662 
  3663 
  3664 *** HOL ***
  3665 
  3666 * Method "metis" proves goals by applying the Metis general-purpose
  3667 resolution prover (see also http://gilith.com/software/metis/).
  3668 Examples are in the directory MetisExamples.  WARNING: the
  3669 Isabelle/HOL-Metis integration does not yet work properly with
  3670 multi-threading.
  3671   
  3672 * Command 'sledgehammer' invokes external automatic theorem provers as
  3673 background processes.  It generates calls to the "metis" method if
  3674 successful. These can be pasted into the proof.  Users do not have to
  3675 wait for the automatic provers to return.  WARNING: does not really
  3676 work with multi-threading.
  3677 
  3678 * New "auto_quickcheck" feature tests outermost goal statements for
  3679 potential counter-examples.  Controlled by ML references
  3680 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3681 5000 milliseconds).  Fails silently if statements is outside of
  3682 executable fragment, or any other codgenerator problem occurs.
  3683 
  3684 * New constant "undefined" with axiom "undefined x = undefined".
  3685 
  3686 * Added class "HOL.eq", allowing for code generation with polymorphic
  3687 equality.
  3688 
  3689 * Some renaming of class constants due to canonical name prefixing in
  3690 the new 'class' package:
  3691 
  3692     HOL.abs ~> HOL.abs_class.abs
  3693     HOL.divide ~> HOL.divide_class.divide
  3694     0 ~> HOL.zero_class.zero
  3695     1 ~> HOL.one_class.one
  3696     op + ~> HOL.plus_class.plus
  3697     op - ~> HOL.minus_class.minus
  3698     uminus ~> HOL.minus_class.uminus
  3699     op * ~> HOL.times_class.times
  3700     op < ~> HOL.ord_class.less
  3701     op <= > HOL.ord_class.less_eq
  3702     Nat.power ~> Power.power_class.power
  3703     Nat.size ~> Nat.size_class.size
  3704     Numeral.number_of ~> Numeral.number_class.number_of
  3705     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3706     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3707     Orderings.min ~> Orderings.ord_class.min
  3708     Orderings.max ~> Orderings.ord_class.max
  3709     Divides.op div ~> Divides.div_class.div
  3710     Divides.op mod ~> Divides.div_class.mod
  3711     Divides.op dvd ~> Divides.div_class.dvd
  3712 
  3713 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3714 
  3715 a) User-defined constants using any of the names "plus", "minus",
  3716 "times", "less" or "less_eq". The standard syntax translations for
  3717 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3718 names.
  3719 
  3720 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3721 INCOMPATIBILITY: use more specific names.
  3722 
  3723 c) Permutative equations (e.g. "a + b = b + a")
  3724 Since the change of names also changes the order of terms, permutative
  3725 rewrite rules may get applied in a different order. Experience shows
  3726 that this is rarely the case (only two adaptions in the whole Isabelle
  3727 distribution).  INCOMPATIBILITY: rewrite proofs
  3728 
  3729 d) ML code directly refering to constant names
  3730 This in general only affects hand-written proof tactics, simprocs and
  3731 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3732 Consider using @{const_name} antiquotation.
  3733 
  3734 * New class "default" with associated constant "default".
  3735 
  3736 * Function "sgn" is now overloaded and available on int, real, complex
  3737 (and other numeric types), using class "sgn".  Two possible defs of
  3738 sgn are given as equational assumptions in the classes sgn_if and
  3739 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3740 INCOMPATIBILITY.
  3741 
  3742 * Locale "partial_order" now unified with class "order" (cf. theory
  3743 Orderings), added parameter "less".  INCOMPATIBILITY.
  3744 
  3745 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3746 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3747 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3748 
  3749 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3750 changed order of proof goals in instance proofs.
  3751 
  3752 * The transitivity reasoner for partial and linear orders is set up
  3753 for classes "order" and "linorder".  Instances of the reasoner are available
  3754 in all contexts importing or interpreting the corresponding locales.
  3755 Method "order" invokes the reasoner separately; the reasoner
  3756 is also integrated with the Simplifier as a solver.  Diagnostic
  3757 command 'print_orders' shows the available instances of the reasoner
  3758 in the current context.
  3759 
  3760 * Localized monotonicity predicate in theory "Orderings"; integrated
  3761 lemmas max_of_mono and min_of_mono with this predicate.
  3762 INCOMPATIBILITY.
  3763 
  3764 * Formulation of theorem "dense" changed slightly due to integration
  3765 with new class dense_linear_order.
  3766 
  3767 * Uniform lattice theory development in HOL.
  3768 
  3769     constants "meet" and "join" now named "inf" and "sup"
  3770     constant "Meet" now named "Inf"
  3771 
  3772     classes "meet_semilorder" and "join_semilorder" now named
  3773       "lower_semilattice" and "upper_semilattice"
  3774     class "lorder" now named "lattice"
  3775     class "comp_lat" now named "complete_lattice"
  3776 
  3777     Instantiation of lattice classes allows explicit definitions
  3778     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3779 
  3780   INCOMPATIBILITY.  Theorem renames:
  3781 
  3782     meet_left_le            ~> inf_le1
  3783     meet_right_le           ~> inf_le2
  3784     join_left_le            ~> sup_ge1
  3785     join_right_le           ~> sup_ge2
  3786     meet_join_le            ~> inf_sup_ord
  3787     le_meetI                ~> le_infI
  3788     join_leI                ~> le_supI
  3789     le_meet                 ~> le_inf_iff
  3790     le_join                 ~> ge_sup_conv
  3791     meet_idempotent         ~> inf_idem
  3792     join_idempotent         ~> sup_idem
  3793     meet_comm               ~> inf_commute
  3794     join_comm               ~> sup_commute
  3795     meet_leI1               ~> le_infI1
  3796     meet_leI2               ~> le_infI2
  3797     le_joinI1               ~> le_supI1
  3798     le_joinI2               ~> le_supI2
  3799     meet_assoc              ~> inf_assoc
  3800     join_assoc              ~> sup_assoc
  3801     meet_left_comm          ~> inf_left_commute
  3802     meet_left_idempotent    ~> inf_left_idem
  3803     join_left_comm          ~> sup_left_commute
  3804     join_left_idempotent    ~> sup_left_idem
  3805     meet_aci                ~> inf_aci
  3806     join_aci                ~> sup_aci
  3807     le_def_meet             ~> le_iff_inf
  3808     le_def_join             ~> le_iff_sup
  3809     join_absorp2            ~> sup_absorb2
  3810     join_absorp1            ~> sup_absorb1
  3811     meet_absorp1            ~> inf_absorb1
  3812     meet_absorp2            ~> inf_absorb2
  3813     meet_join_absorp        ~> inf_sup_absorb
  3814     join_meet_absorp        ~> sup_inf_absorb
  3815     distrib_join_le         ~> distrib_sup_le
  3816     distrib_meet_le         ~> distrib_inf_le
  3817 
  3818     add_meet_distrib_left   ~> add_inf_distrib_left
  3819     add_join_distrib_left   ~> add_sup_distrib_left
  3820     is_join_neg_meet        ~> is_join_neg_inf
  3821     is_meet_neg_join        ~> is_meet_neg_sup
  3822     add_meet_distrib_right  ~> add_inf_distrib_right
  3823     add_join_distrib_right  ~> add_sup_distrib_right
  3824     add_meet_join_distribs  ~> add_sup_inf_distribs
  3825     join_eq_neg_meet        ~> sup_eq_neg_inf
  3826     meet_eq_neg_join        ~> inf_eq_neg_sup
  3827     add_eq_meet_join        ~> add_eq_inf_sup
  3828     meet_0_imp_0            ~> inf_0_imp_0
  3829     join_0_imp_0            ~> sup_0_imp_0
  3830     meet_0_eq_0             ~> inf_0_eq_0
  3831     join_0_eq_0             ~> sup_0_eq_0
  3832     neg_meet_eq_join        ~> neg_inf_eq_sup
  3833     neg_join_eq_meet        ~> neg_sup_eq_inf
  3834     join_eq_if              ~> sup_eq_if
  3835 
  3836     mono_meet               ~> mono_inf
  3837     mono_join               ~> mono_sup
  3838     meet_bool_eq            ~> inf_bool_eq
  3839     join_bool_eq            ~> sup_bool_eq
  3840     meet_fun_eq             ~> inf_fun_eq
  3841     join_fun_eq             ~> sup_fun_eq
  3842     meet_set_eq             ~> inf_set_eq
  3843     join_set_eq             ~> sup_set_eq
  3844     meet1_iff               ~> inf1_iff
  3845     meet2_iff               ~> inf2_iff
  3846     meet1I                  ~> inf1I
  3847     meet2I                  ~> inf2I
  3848     meet1D1                 ~> inf1D1
  3849     meet2D1                 ~> inf2D1
  3850     meet1D2                 ~> inf1D2
  3851     meet2D2                 ~> inf2D2
  3852     meet1E                  ~> inf1E
  3853     meet2E                  ~> inf2E
  3854     join1_iff               ~> sup1_iff
  3855     join2_iff               ~> sup2_iff
  3856     join1I1                 ~> sup1I1
  3857     join2I1                 ~> sup2I1
  3858     join1I1                 ~> sup1I1
  3859     join2I2                 ~> sup1I2
  3860     join1CI                 ~> sup1CI
  3861     join2CI                 ~> sup2CI
  3862     join1E                  ~> sup1E
  3863     join2E                  ~> sup2E
  3864 
  3865     is_meet_Meet            ~> is_meet_Inf
  3866     Meet_bool_def           ~> Inf_bool_def
  3867     Meet_fun_def            ~> Inf_fun_def
  3868     Meet_greatest           ~> Inf_greatest
  3869     Meet_lower              ~> Inf_lower
  3870     Meet_set_def            ~> Inf_set_def
  3871 
  3872     Sup_def                 ~> Sup_Inf
  3873     Sup_bool_eq             ~> Sup_bool_def
  3874     Sup_fun_eq              ~> Sup_fun_def
  3875     Sup_set_eq              ~> Sup_set_def
  3876 
  3877     listsp_meetI            ~> listsp_infI
  3878     listsp_meet_eq          ~> listsp_inf_eq
  3879 
  3880     meet_min                ~> inf_min
  3881     join_max                ~> sup_max
  3882 
  3883 * Added syntactic class "size"; overloaded constant "size" now has
  3884 type "'a::size ==> bool"
  3885 
  3886 * Internal reorganisation of `size' of datatypes: size theorems
  3887 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3888 simplification rules by default!); theorems "prod.size" now named
  3889 "*.size".
  3890 
  3891 * Class "div" now inherits from class "times" rather than "type".
  3892 INCOMPATIBILITY.
  3893 
  3894 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3895 Linorder etc.  have disappeared; operations defined in terms of
  3896 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3897 
  3898 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3899 
  3900 * HOL-Word: New extensive library and type for generic, fixed size
  3901 machine words, with arithemtic, bit-wise, shifting and rotating
  3902 operations, reflection into int, nat, and bool lists, automation for
  3903 linear arithmetic (by automatic reflection into nat or int), including
  3904 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3905 arithmetic type classes, supporting automatic simplification of
  3906 numerals on all operations.
  3907 
  3908 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3909 
  3910 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3911 
  3912 * Code generator library theories:
  3913   - Code_Integer represents HOL integers by big integer literals in target
  3914     languages.
  3915   - Code_Char represents HOL characters by character literals in target
  3916     languages.
  3917   - Code_Char_chr like Code_Char, but also offers treatment of character
  3918     codes; includes Code_Integer.
  3919   - Executable_Set allows to generate code for finite sets using lists.
  3920   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3921     denominator).
  3922   - Executable_Real implements a subset of real numbers, namly those
  3923     representable by rational numbers.
  3924   - Efficient_Nat implements natural numbers by integers, which in general will
  3925     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3926     includes Code_Integer.
  3927   - Code_Index provides an additional datatype index which is mapped to
  3928     target-language built-in integers.
  3929   - Code_Message provides an additional datatype message_string which is isomorphic to
  3930     strings; messages are mapped to target-language strings.
  3931 
  3932 * New package for inductive predicates
  3933 
  3934   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3935 
  3936     inductive
  3937       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3938       for z_1 :: U_1 and ... and z_n :: U_m
  3939     where
  3940       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3941     | ...
  3942 
  3943   with full support for type-inference, rather than
  3944 
  3945     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3946 
  3947     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3948     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3949 
  3950     inductive "s z_1 ... z_m"
  3951     intros
  3952       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3953       ...
  3954 
  3955   For backward compatibility, there is a wrapper allowing inductive
  3956   sets to be defined with the new package via
  3957 
  3958     inductive_set
  3959       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3960       for z_1 :: U_1 and ... and z_n :: U_m
  3961     where
  3962       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3963     | ...
  3964 
  3965   or
  3966 
  3967     inductive_set
  3968       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3969       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3970       for z_1 :: U_1 and ... and z_n :: U_m
  3971     where
  3972       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3973     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3974     | ...
  3975 
  3976   if the additional syntax "p ..." is required.
  3977 
  3978   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3979   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3980 
  3981   INCOMPATIBILITIES:
  3982 
  3983   - Since declaration and definition of inductive sets or predicates
  3984     is no longer separated, abbreviations involving the newly
  3985     introduced sets or predicates must be specified together with the
  3986     introduction rules after the 'where' keyword (see above), rather
  3987     than before the actual inductive definition.
  3988 
  3989   - The variables in induction and elimination rules are now
  3990     quantified in the order of their occurrence in the introduction
  3991     rules, rather than in alphabetical order. Since this may break
  3992     some proofs, these proofs either have to be repaired, e.g. by
  3993     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3994     statements of the form
  3995 
  3996       case (rule_i a_i_1 ... a_i_{k_i})
  3997 
  3998     or the old order of quantification has to be restored by explicitly adding
  3999     meta-level quantifiers in the introduction rules, i.e.
  4000 
  4001       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4002 
  4003   - The format of the elimination rules is now
  4004 
  4005       p z_1 ... z_m x_1 ... x_n ==>
  4006         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4007         ==> ... ==> P
  4008 
  4009     for predicates and
  4010 
  4011       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4012         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4013         ==> ... ==> P
  4014 
  4015     for sets rather than
  4016 
  4017       x : s z_1 ... z_m ==>
  4018         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4019         ==> ... ==> P
  4020 
  4021     This may require terms in goals to be expanded to n-tuples
  4022     (e.g. using case_tac or simplification with the split_paired_all
  4023     rule) before the above elimination rule is applicable.
  4024 
  4025   - The elimination or case analysis rules for (mutually) inductive
  4026     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4027     list of rules "p_1_..._p_k.elims" is no longer available.
  4028 
  4029 * New package "function"/"fun" for general recursive functions,
  4030 supporting mutual and nested recursion, definitions in local contexts,
  4031 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4032 for small examples, and the separate tutorial on the function
  4033 package. The old recdef "package" is still available as before, but
  4034 users are encouraged to use the new package.
  4035 
  4036 * Method "lexicographic_order" automatically synthesizes termination
  4037 relations as lexicographic combinations of size measures. 
  4038 
  4039 * Case-expressions allow arbitrary constructor-patterns (including
  4040 "_") and take their order into account, like in functional
  4041 programming.  Internally, this is translated into nested
  4042 case-expressions; missing cases are added and mapped to the predefined
  4043 constant "undefined". In complicated cases printing may no longer show
  4044 the original input but the internal form. Lambda-abstractions allow
  4045 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4046 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4047 variable.
  4048 
  4049 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4050 is an abbreviation for "of_nat :: nat => int". The simplification
  4051 rules for "of_nat" have been changed to work like "int" did
  4052 previously.  Potential INCOMPATIBILITY:
  4053   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4054   - of_nat_diff and of_nat_mult are no longer default simp rules
  4055 
  4056 * Method "algebra" solves polynomial equations over (semi)rings using
  4057 Groebner bases. The (semi)ring structure is defined by locales and the
  4058 tool setup depends on that generic context. Installing the method for
  4059 a specific type involves instantiating the locale and possibly adding
  4060 declarations for computation on the coefficients.  The method is
  4061 already instantiated for natural numbers and for the axiomatic class
  4062 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4063 CALCULEMUS 2007 for the general principles underlying this
  4064 architecture of context-aware proof-tools.
  4065 
  4066 * Method "ferrack" implements quantifier elimination over
  4067 special-purpose dense linear orders using locales (analogous to
  4068 "algebra"). The method is already installed for class
  4069 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4070 rat, etc.
  4071 
  4072 * Former constant "List.op @" now named "List.append".  Use ML
  4073 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4074 circumvent possible incompatibilities when working on ML level.
  4075 
  4076 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4077 
  4078 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4079 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4080 
  4081 * New syntax for Haskell-like list comprehension (input only), eg.
  4082 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4083 
  4084 * The special syntax for function "filter" has changed from [x :
  4085 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4086 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4087 
  4088 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4089 defined on nat only, as an abbreviation for [a..<Suc b]
  4090 INCOMPATIBILITY.
  4091 
  4092 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4093 
  4094 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4095 
  4096 * New lemma collection field_simps (an extension of ring_simps) for
  4097 manipulating (in)equations involving division. Multiplies with all
  4098 denominators that can be proved to be non-zero (in equations) or
  4099 positive/negative (in inequations).
  4100 
  4101 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4102 have been improved and renamed to ring_simps, group_simps and
  4103 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4104 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4105 
  4106 * Theory Library/Commutative_Ring: switched from recdef to function
  4107 package; constants add, mul, pow now curried.  Infix syntax for
  4108 algebraic operations.
  4109 
  4110 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4111 INCOMPATIBILITY.
  4112 
  4113 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4114 INCOMPATIBILITY.
  4115 
  4116 * HOL/records: generalised field-update to take a function on the
  4117 field rather than the new value: r(|A := x|) is translated to A_update
  4118 (K x) r The K-combinator that is internally used is called K_record.
  4119 INCOMPATIBILITY: Usage of the plain update functions has to be
  4120 adapted.
  4121  
  4122 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4123 * x = 0, which are required for a semiring.  Richer structures do not
  4124 inherit from semiring_0 anymore, because this property is a theorem
  4125 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4126 there is more to prove, but this is mostly trivial.
  4127 
  4128 * Class "recpower" is generalized to arbitrary monoids, not just
  4129 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4130 commutativity or semiring properties additionally.
  4131 
  4132 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4133 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4134 better use 'abbreviation'.
  4135 
  4136 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4137 
  4138 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4139 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4140 significant changes for setting up numeral syntax for types:
  4141   - New constants Numeral.pred and Numeral.succ instead
  4142       of former Numeral.bin_pred and Numeral.bin_succ.
  4143   - Use integer operations instead of bin_add, bin_mult and so on.
  4144   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4145   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4146 
  4147 See src/HOL/Integ/IntArith.thy for an example setup.
  4148 
  4149 * Command 'normal_form' computes the normal form of a term that may
  4150 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4151 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4152 heavy-duty computations because the functions are compiled to ML
  4153 first.  Correspondingly, a method "normalization" is provided.  See
  4154 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4155 
  4156 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4157 25 like -->); output depends on the "iff" print_mode, the default is
  4158 "A = B" (with priority 50).
  4159 
  4160 * Relations less (<) and less_eq (<=) are also available on type bool.
  4161 Modified syntax to disallow nesting without explicit parentheses,
  4162 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4163 INCOMPATIBILITY.
  4164 
  4165 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4166 
  4167 * Relation composition operator "op O" now has precedence 75 and binds
  4168 stronger than union and intersection. INCOMPATIBILITY.
  4169 
  4170 * The old set interval syntax "{m..n(}" (and relatives) has been
  4171 removed.  Use "{m..<n}" (and relatives) instead.
  4172 
  4173 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4174 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4175 ``declare [[simproc del: neq]]''.
  4176 
  4177 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4178 True/False.
  4179 
  4180 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4181 
  4182 * Theorem setsum_mult renamed to setsum_right_distrib.
  4183 
  4184 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4185 ``rule'' method.
  4186 
  4187 * Reimplemented methods "sat" and "satx", with several improvements:
  4188 goals no longer need to be stated as "<prems> ==> False", equivalences
  4189 (i.e. "=" on type bool) are handled, variable names of the form
  4190 "lit_<n>" are no longer reserved, significant speedup.
  4191 
  4192 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4193 zChaff is still supported as well.
  4194 
  4195 * 'inductive' and 'datatype': provide projections of mutual rules,
  4196 bundled as foo_bar.inducts;
  4197 
  4198 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4199 Library.
  4200 
  4201 * Library: moved theory Accessible_Part to main HOL.
  4202 
  4203 * Library: added theory Coinductive_List of potentially infinite lists
  4204 as greatest fixed-point.
  4205 
  4206 * Library: added theory AssocList which implements (finite) maps as
  4207 association lists.
  4208 
  4209 * Method "evaluation" solves goals (i.e. a boolean expression)
  4210 efficiently by compiling it to ML.  The goal is "proved" (via an
  4211 oracle) if it evaluates to True.
  4212 
  4213 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4214 also when invoked by the simplifier.  This results in the Simplifier
  4215 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4216 Configuration option fast_arith_split_limit=0 recovers the old
  4217 behavior.
  4218 
  4219 * Support for hex (0x20) and binary (0b1001) numerals.
  4220 
  4221 * New method: reify eqs (t), where eqs are equations for an
  4222 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4223 parameter, computes a term s::'b and a list xs::'a list and proves the
  4224 theorem I xs s = t. This is also known as reification or quoting. The
  4225 resulting theorem is applied to the subgoal to substitute t with I xs
  4226 s.  If t is omitted, the subgoal itself is reified.
  4227 
  4228 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4229 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4230 where f is supposed to be a computable function (in the sense of code
  4231 generattion). The method uses reify to compute s and xs as above then
  4232 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4233 r and finally gets the theorem t = r, which is again applied to the
  4234 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4235 
  4236 * Reflection: Automatic reification now handels binding, an example is
  4237 available in src/HOL/ex/ReflectionEx.thy
  4238 
  4239 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4240 command 'statespace' that is similar to 'record', but introduces an
  4241 abstract specification based on the locale infrastructure instead of
  4242 HOL types.  This leads to extra flexibility in composing state spaces,
  4243 in particular multiple inheritance and renaming of components.
  4244 
  4245 
  4246 *** HOL-Complex ***
  4247 
  4248 * Hyperreal: Functions root and sqrt are now defined on negative real
  4249 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4250 Nonnegativity side conditions have been removed from many lemmas, so
  4251 that more subgoals may now be solved by simplification; potential
  4252 INCOMPATIBILITY.
  4253 
  4254 * Real: new type classes formalize real normed vector spaces and
  4255 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4256 and norm :: 'a => real.
  4257 
  4258 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4259 reals into other types. The overloaded constant Reals :: 'a set is now
  4260 defined as range of_real; potential INCOMPATIBILITY.
  4261 
  4262 * Real: proper support for ML code generation, including 'quickcheck'.
  4263 Reals are implemented as arbitrary precision rationals.
  4264 
  4265 * Hyperreal: Several constants that previously worked only for the
  4266 reals have been generalized, so they now work over arbitrary vector
  4267 spaces. Type annotations may need to be added in some cases; potential
  4268 INCOMPATIBILITY.
  4269 
  4270   Infinitesimal  :: ('a::real_normed_vector) star set
  4271   HFinite        :: ('a::real_normed_vector) star set
  4272   HInfinite      :: ('a::real_normed_vector) star set
  4273   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4274   monad          :: ('a::real_normed_vector) star => 'a star set
  4275   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4276   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4277   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4278   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4279   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4280   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4281   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4282   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4283   sgn            :: 'a::real_normed_vector => 'a
  4284   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4285 
  4286 * Complex: Some complex-specific constants are now abbreviations for
  4287 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4288 hnorm.  Other constants have been entirely removed in favor of the
  4289 polymorphic versions (INCOMPATIBILITY):
  4290 
  4291   approx        <-- capprox
  4292   HFinite       <-- CFinite
  4293   HInfinite     <-- CInfinite
  4294   Infinitesimal <-- CInfinitesimal
  4295   monad         <-- cmonad
  4296   galaxy        <-- cgalaxy
  4297   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4298   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4299   (ns)deriv     <-- (ns)cderiv
  4300 
  4301 
  4302 *** HOL-Algebra ***
  4303 
  4304 * Formalisation of ideals and the quotient construction over rings.
  4305 
  4306 * Order and lattice theory no longer based on records.
  4307 INCOMPATIBILITY.
  4308 
  4309 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4310 greatest_closed.  INCOMPATIBILITY.
  4311 
  4312 * Method algebra is now set up via an attribute.  For examples see
  4313 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4314 of algebraic structures.
  4315 
  4316 * Renamed theory CRing to Ring.
  4317 
  4318 
  4319 *** HOL-Nominal ***
  4320 
  4321 * Substantial, yet incomplete support for nominal datatypes (binding
  4322 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4323 src/HOL/Nominal/Examples.  Prospective users should consult
  4324 http://isabelle.in.tum.de/nominal/
  4325 
  4326 
  4327 *** ML ***
  4328 
  4329 * ML basics: just one true type int, which coincides with IntInf.int
  4330 (even on SML/NJ).
  4331 
  4332 * ML within Isar: antiquotations allow to embed statically-checked
  4333 formal entities in the source, referring to the context available at
  4334 compile-time.  For example:
  4335 
  4336 ML {* @{sort "{zero,one}"} *}
  4337 ML {* @{typ "'a => 'b"} *}
  4338 ML {* @{term "%x. x"} *}
  4339 ML {* @{prop "x == y"} *}
  4340 ML {* @{ctyp "'a => 'b"} *}
  4341 ML {* @{cterm "%x. x"} *}
  4342 ML {* @{cprop "x == y"} *}
  4343 ML {* @{thm asm_rl} *}
  4344 ML {* @{thms asm_rl} *}
  4345 ML {* @{type_name c} *}
  4346 ML {* @{type_syntax c} *}
  4347 ML {* @{const_name c} *}
  4348 ML {* @{const_syntax c} *}
  4349 ML {* @{context} *}
  4350 ML {* @{theory} *}
  4351 ML {* @{theory Pure} *}
  4352 ML {* @{theory_ref} *}
  4353 ML {* @{theory_ref Pure} *}
  4354 ML {* @{simpset} *}
  4355 ML {* @{claset} *}
  4356 ML {* @{clasimpset} *}
  4357 
  4358 The same works for sources being ``used'' within an Isar context.
  4359 
  4360 * ML in Isar: improved error reporting; extra verbosity with
  4361 ML_Context.trace enabled.
  4362 
  4363 * Pure/General/table.ML: the join operations now works via exceptions
  4364 DUP/SAME instead of type option. This is simpler in simple cases, and
  4365 admits slightly more efficient complex applications.
  4366 
  4367 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4368 use Context.generic instead of just theory.
  4369 
  4370 * Pure: datatype Context.generic joins theory/Proof.context and
  4371 provides some facilities for code that works in either kind of
  4372 context, notably GenericDataFun for uniform theory and proof data.
  4373 
  4374 * Pure: simplified internal attribute type, which is now always
  4375 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4376 local (Proof.context) attributes have been discontinued, while
  4377 minimizing code duplication. Thm.rule_attribute and
  4378 Thm.declaration_attribute build canonical attributes; see also structure
  4379 Context for further operations on Context.generic, notably
  4380 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4381 declarations and definitions.
  4382 
  4383 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4384 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4385 init only required for impure data. INCOMPATIBILITY: empty really need
  4386 to be empty (no dependencies on theory content!)
  4387 
  4388 * Pure/kernel: consts certification ignores sort constraints given in
  4389 signature declarations. (This information is not relevant to the
  4390 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4391 potential INCOMPATIBILITY.
  4392 
  4393 * Pure: axiomatic type classes are now purely definitional, with
  4394 explicit proofs of class axioms and super class relations performed
  4395 internally. See Pure/axclass.ML for the main internal interfaces --
  4396 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4397 AxClass.axiomatize_class/classrel/arity supersede
  4398 Sign.add_classes/classrel/arities.
  4399 
  4400 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4401 global/local versions on theory vs. Proof.context have been
  4402 discontinued; Attrib.syntax and Method.syntax have been adapted
  4403 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4404 attributes, methods, etc.
  4405 
  4406 * Pure: several functions of signature "... -> theory -> theory * ..."
  4407 have been reoriented to "... -> theory -> ... * theory" in order to
  4408 allow natural usage in combination with the ||>, ||>>, |-> and
  4409 fold_map combinators.
  4410 
  4411 * Pure: official theorem names (closed derivations) and additional
  4412 comments (tags) are now strictly separate.  Name hints -- which are
  4413 maintained as tags -- may be attached any time without affecting the
  4414 derivation.
  4415 
  4416 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4417 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4418 achieve the old behaviour.
  4419 
  4420 * Pure: the "Goal" constant is now called "prop", supporting a
  4421 slightly more general idea of ``protecting'' meta-level rule
  4422 statements.
  4423 
  4424 * Pure: Logic.(un)varify only works in a global context, which is now
  4425 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4426 Logic.legacy_(un)varify as temporary workaround.
  4427 
  4428 * Pure: structure Name provides scalable operations for generating
  4429 internal variable names, notably Name.variants etc.  This replaces
  4430 some popular functions from term.ML:
  4431 
  4432   Term.variant		->  Name.variant
  4433   Term.variantlist	->  Name.variant_list
  4434   Term.invent_names	->  Name.invent_list
  4435 
  4436 Note that low-level renaming rarely occurs in new code -- operations
  4437 from structure Variable are used instead (see below).
  4438 
  4439 * Pure: structure Variable provides fundamental operations for proper
  4440 treatment of fixed/schematic variables in a context.  For example,
  4441 Variable.import introduces fixes for schematics of given facts and
  4442 Variable.export reverses the effect (up to renaming) -- this replaces
  4443 various freeze_thaw operations.
  4444 
  4445 * Pure: structure Goal provides simple interfaces for
  4446 init/conclude/finish and tactical prove operations (replacing former
  4447 Tactic.prove).  Goal.prove is the canonical way to prove results
  4448 within a given context; Goal.prove_global is a degraded version for
  4449 theory level goals, including a global Drule.standard.  Note that
  4450 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4451 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4452 in a locale context).
  4453 
  4454 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4455 and type checking (Syntax.check_term etc.), with common combinations
  4456 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4457 which are considered legacy and await removal.
  4458 
  4459 * Pure/Syntax: generic interfaces for type unchecking
  4460 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4461 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4462 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4463 available for convenience, but refer to the very same operations using
  4464 a mere theory instead of a full context.
  4465 
  4466 * Isar: simplified treatment of user-level errors, using exception
  4467 ERROR of string uniformly.  Function error now merely raises ERROR,
  4468 without any side effect on output channels.  The Isar toplevel takes
  4469 care of proper display of ERROR exceptions.  ML code may use plain
  4470 handle/can/try; cat_error may be used to concatenate errors like this:
  4471 
  4472   ... handle ERROR msg => cat_error msg "..."
  4473 
  4474 Toplevel ML code (run directly or through the Isar toplevel) may be
  4475 embedded into the Isar toplevel with exception display/debug like
  4476 this:
  4477 
  4478   Isar.toplevel (fn () => ...)
  4479 
  4480 INCOMPATIBILITY, removed special transform_error facilities, removed
  4481 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4482 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4483 -- use plain ERROR instead.
  4484 
  4485 * Isar: theory setup now has type (theory -> theory), instead of a
  4486 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4487 
  4488 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4489 ProofContext.debug/verbose flags.
  4490 
  4491 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4492 theory before entering a proof state.  Transactions now always see a
  4493 quasi-functional intermediate checkpoint, both in interactive and
  4494 batch mode.
  4495 
  4496 * Isar: simplified interfaces for outer syntax.  Renamed
  4497 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4498 OuterSyntax.add_parsers -- this functionality is now included in
  4499 OuterSyntax.command etc.  INCOMPATIBILITY.
  4500 
  4501 * Simplifier: the simpset of a running simplification process now
  4502 contains a proof context (cf. Simplifier.the_context), which is the
  4503 very context that the initial simpset has been retrieved from (by
  4504 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4505 (solver, looper etc.) may depend on arbitrary proof data.
  4506 
  4507 * Simplifier.inherit_context inherits the proof context (plus the
  4508 local bounds) of the current simplification process; any simproc
  4509 etc. that calls the Simplifier recursively should do this!  Removed
  4510 former Simplifier.inherit_bounds, which is already included here --
  4511 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4512 specify an explicit context using Simplifier.context/theory_context.
  4513 
  4514 * Simplifier/Classical Reasoner: more abstract interfaces
  4515 change_simpset/claset for modifying the simpset/claset reference of a
  4516 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4517 INCOMPATIBILITY.
  4518 
  4519 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4520 "Trueprop" etc.
  4521 
  4522 
  4523 *** System ***
  4524 
  4525 * settings: the default heap location within ISABELLE_HOME_USER now
  4526 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4527 Isabelle installations.
  4528 
  4529 * isabelle-process: option -S (secure mode) disables some critical
  4530 operations, notably runtime compilation and evaluation of ML source
  4531 code.
  4532 
  4533 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4534 
  4535 * Support for parallel execution, using native multicore support of
  4536 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4537 independent theories, according to the given theory header
  4538 specifications. The maximum number of worker threads is specified via
  4539 usedir option -M or the "max-threads" setting in Proof General. A
  4540 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4541 to 6 on a 8-core machine.  User-code needs to observe certain
  4542 guidelines for thread-safe programming, see appendix A in the Isar
  4543 Implementation manual.
  4544 
  4545 
  4546 
  4547 New in Isabelle2005 (October 2005)
  4548 ----------------------------------
  4549 
  4550 *** General ***
  4551 
  4552 * Theory headers: the new header syntax for Isar theories is
  4553 
  4554   theory <name>
  4555   imports <theory1> ... <theoryN>
  4556   uses <file1> ... <fileM>
  4557   begin
  4558 
  4559 where the 'uses' part is optional.  The previous syntax
  4560 
  4561   theory <name> = <theory1> + ... + <theoryN>:
  4562 
  4563 will disappear in the next release.  Use isatool fixheaders to convert
  4564 existing theory files.  Note that there is no change in ancient
  4565 non-Isar theories now, but these will disappear soon.
  4566 
  4567 * Theory loader: parent theories can now also be referred to via
  4568 relative and absolute paths.
  4569 
  4570 * Command 'find_theorems' searches for a list of criteria instead of a
  4571 list of constants. Known criteria are: intro, elim, dest, name:string,
  4572 simp:term, and any term. Criteria can be preceded by '-' to select
  4573 theorems that do not match. Intro, elim, dest select theorems that
  4574 match the current goal, name:s selects theorems whose fully qualified
  4575 name contain s, and simp:term selects all simplification rules whose
  4576 lhs match term.  Any other term is interpreted as pattern and selects
  4577 all theorems matching the pattern. Available in ProofGeneral under
  4578 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4579 
  4580   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4581 
  4582 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4583 matching the current goal as introduction rule and not having "HOL."
  4584 in their name (i.e. not being defined in theory HOL).
  4585 
  4586 * Command 'thms_containing' has been discontinued in favour of
  4587 'find_theorems'; INCOMPATIBILITY.
  4588 
  4589 * Communication with Proof General is now 8bit clean, which means that
  4590 Unicode text in UTF-8 encoding may be used within theory texts (both
  4591 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4592 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4593 
  4594   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4595   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4596 
  4597 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4598 Classical Reasoner.  Typical big applications run around 2 times
  4599 faster.
  4600 
  4601 
  4602 *** Document preparation ***
  4603 
  4604 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4605 of raw sources.  Only those symbols that do not require additional
  4606 LaTeX packages (depending on comments in isabellesym.sty) are
  4607 displayed properly, everything else is left verbatim.  isatool display
  4608 and isatool print are used as front ends (these are subject to the
  4609 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4610 
  4611 * Command tags control specific markup of certain regions of text,
  4612 notably folding and hiding.  Predefined tags include "theory" (for
  4613 theory begin and end), "proof" for proof commands, and "ML" for
  4614 commands involving ML code; the additional tags "visible" and
  4615 "invisible" are unused by default.  Users may give explicit tag
  4616 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4617 interpretation of tags is determined by the LaTeX job during document
  4618 preparation: see option -V of isatool usedir, or options -n and -t of
  4619 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4620 \isadroptag.
  4621 
  4622 Several document versions may be produced at the same time via isatool
  4623 usedir (the generated index.html will link all of them).  Typical
  4624 specifications include ''-V document=theory,proof,ML'' to present
  4625 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4626 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4627 these parts without any formal replacement text.  The Isabelle site
  4628 default settings produce ''document'' and ''outline'' versions as
  4629 specified above.
  4630 
  4631 * Several new antiquotations:
  4632 
  4633   @{term_type term} prints a term with its type annotated;
  4634 
  4635   @{typeof term} prints the type of a term;
  4636 
  4637   @{const const} is the same as @{term const}, but checks that the
  4638   argument is a known logical constant;
  4639 
  4640   @{term_style style term} and @{thm_style style thm} print a term or
  4641   theorem applying a "style" to it
  4642 
  4643   @{ML text}
  4644 
  4645 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4646 definitions, equations, inequations etc., 'concl' printing only the
  4647 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4648 to print the specified premise.  TermStyle.add_style provides an ML
  4649 interface for introducing further styles.  See also the "LaTeX Sugar"
  4650 document practical applications.  The ML antiquotation prints
  4651 type-checked ML expressions verbatim.
  4652 
  4653 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4654 and 'text' support optional locale specification '(in loc)', which
  4655 specifies the default context for interpreting antiquotations.  For
  4656 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4657 
  4658 * Option 'locale=NAME' of antiquotations specifies an alternative
  4659 context interpreting the subsequent argument.  For example: @{thm
  4660 [locale=lattice] inf_assoc}.
  4661 
  4662 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4663 a proof context.
  4664 
  4665 * Proper output of antiquotations for theory commands involving a
  4666 proof context (such as 'locale' or 'theorem (in loc) ...').
  4667 
  4668 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4669 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4670 
  4671 * isatool usedir: new option -C (default true) controls whether option
  4672 -D should include a copy of the original document directory; -C false
  4673 prevents unwanted effects such as copying of administrative CVS data.
  4674 
  4675 
  4676 *** Pure ***
  4677 
  4678 * Considerably improved version of 'constdefs' command.  Now performs
  4679 automatic type-inference of declared constants; additional support for
  4680 local structure declarations (cf. locales and HOL records), see also
  4681 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4682 sequential dependencies of definitions within a single 'constdefs'
  4683 section; moreover, the declared name needs to be an identifier.  If
  4684 all fails, consider to fall back on 'consts' and 'defs' separately.
  4685 
  4686 * Improved indexed syntax and implicit structures.  First of all,
  4687 indexed syntax provides a notational device for subscripted
  4688 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4689 expressions.  Secondly, in a local context with structure
  4690 declarations, number indexes \<^sub>n or the empty index (default
  4691 number 1) refer to a certain fixed variable implicitly; option
  4692 show_structs controls printing of implicit structures.  Typical
  4693 applications of these concepts involve record types and locales.
  4694 
  4695 * New command 'no_syntax' removes grammar declarations (and
  4696 translations) resulting from the given syntax specification, which is
  4697 interpreted in the same manner as for the 'syntax' command.
  4698 
  4699 * 'Advanced' translation functions (parse_translation etc.) may depend
  4700 on the signature of the theory context being presently used for
  4701 parsing/printing, see also isar-ref manual.
  4702 
  4703 * Improved 'oracle' command provides a type-safe interface to turn an
  4704 ML expression of type theory -> T -> term into a primitive rule of
  4705 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4706 is already included here); see also FOL/ex/IffExample.thy;
  4707 INCOMPATIBILITY.
  4708 
  4709 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4710 before); "cI" is no longer bound, use "c.intro" instead.
  4711 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4712 axclasses vs. locales.
  4713 
  4714 * Improved internal renaming of symbolic identifiers -- attach primes
  4715 instead of base 26 numbers.
  4716 
  4717 * New flag show_question_marks controls printing of leading question
  4718 marks in schematic variable names.
  4719 
  4720 * In schematic variable names, *any* symbol following \<^isub> or
  4721 \<^isup> is now treated as part of the base name.  For example, the
  4722 following works without printing of awkward ".0" indexes:
  4723 
  4724   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4725     by simp
  4726 
  4727 * Inner syntax includes (*(*nested*) comments*).
  4728 
  4729 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4730 annotations as "(00...)".
  4731 
  4732 * Clear separation of logical types and nonterminals, where the latter
  4733 may only occur in 'syntax' specifications or type abbreviations.
  4734 Before that distinction was only partially implemented via type class
  4735 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4736 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4737 exotic syntax specifications may require further adaption
  4738 (e.g. Cube/Cube.thy).
  4739 
  4740 * Removed obsolete type class "logic", use the top sort {} instead.
  4741 Note that non-logical types should be declared as 'nonterminals'
  4742 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4743 specifications.
  4744 
  4745 * Attributes 'induct' and 'cases': type or set names may now be
  4746 locally fixed variables as well.
  4747 
  4748 * Simplifier: can now control the depth to which conditional rewriting
  4749 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4750 Limit.
  4751 
  4752 * Simplifier: simplification procedures may now take the current
  4753 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4754 interface), which is very useful for calling the Simplifier
  4755 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4756 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4757 low-level mk_simproc no longer applies Logic.varify internally, to
  4758 allow for use in a context of fixed variables.
  4759 
  4760 * thin_tac now works even if the assumption being deleted contains !!
  4761 or ==>.  More generally, erule now works even if the major premise of
  4762 the elimination rule contains !! or ==>.
  4763 
  4764 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4765 
  4766 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4767 from Pure, which contains all common declarations already.  Both
  4768 theories are defined via plain Isabelle/Isar .thy files.
  4769 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4770 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4771 use isatool fixcpure to adapt your theory and ML sources.
  4772 
  4773 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4774 selections of theorems in named facts via index ranges.
  4775 
  4776 * 'print_theorems': in theory mode, really print the difference
  4777 wrt. the last state (works for interactive theory development only),
  4778 in proof mode print all local facts (cf. 'print_facts');
  4779 
  4780 * 'hide': option '(open)' hides only base names.
  4781 
  4782 * More efficient treatment of intermediate checkpoints in interactive
  4783 theory development.
  4784 
  4785 * Code generator is now invoked via code_module (incremental code
  4786 generation) and code_library (modular code generation, ML structures
  4787 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4788 must be quoted when used as identifiers.
  4789 
  4790 * New 'value' command for reading, evaluating and printing terms using
  4791 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4792 quoted when used as identifier.
  4793 
  4794 
  4795 *** Locales ***
  4796 
  4797 * New commands for the interpretation of locale expressions in
  4798 theories (1), locales (2) and proof contexts (3).  These generate
  4799 proof obligations from the expression specification.  After the
  4800 obligations have been discharged, theorems of the expression are added
  4801 to the theory, target locale or proof context.  The synopsis of the
  4802 commands is a follows:
  4803 
  4804   (1) interpretation expr inst
  4805   (2) interpretation target < expr
  4806   (3) interpret expr inst
  4807 
  4808 Interpretation in theories and proof contexts require a parameter
  4809 instantiation of terms from the current context.  This is applied to
  4810 specifications and theorems of the interpreted expression.
  4811 Interpretation in locales only permits parameter renaming through the
  4812 locale expression.  Interpretation is smart in that interpretations
  4813 that are active already do not occur in proof obligations, neither are
  4814 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4815 inspect active interpretations of a particular locale.  For details,
  4816 see the Isar Reference manual.  Examples can be found in
  4817 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4818 
  4819 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4820 'interpret' instead.
  4821 
  4822 * New context element 'constrains' for adding type constraints to
  4823 parameters.
  4824 
  4825 * Context expressions: renaming of parameters with syntax
  4826 redeclaration.
  4827 
  4828 * Locale declaration: 'includes' disallowed.
  4829 
  4830 * Proper static binding of attribute syntax -- i.e. types / terms /
  4831 facts mentioned as arguments are always those of the locale definition
  4832 context, independently of the context of later invocations.  Moreover,
  4833 locale operations (renaming and type / term instantiation) are applied
  4834 to attribute arguments as expected.
  4835 
  4836 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4837 actual attributes; rare situations may require Attrib.attribute to
  4838 embed those attributes into Attrib.src that lack concrete syntax.
  4839 Attribute implementations need to cooperate properly with the static
  4840 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4841 Attrib.XXX_thm etc. already do the right thing without further
  4842 intervention.  Only unusual applications -- such as "where" or "of"
  4843 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4844 on the context and the facts involved -- may have to assign parsed
  4845 values to argument tokens explicitly.
  4846 
  4847 * Changed parameter management in theorem generation for long goal
  4848 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4849 theorem statement in rare situations.
  4850 
  4851 * Locale inspection command 'print_locale' omits notes elements.  Use
  4852 'print_locale!' to have them included in the output.
  4853 
  4854 
  4855 *** Provers ***
  4856 
  4857 * Provers/hypsubst.ML: improved version of the subst method, for
  4858 single-step rewriting: it now works in bound variable contexts. New is
  4859 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4860 rewrite a different subterm than the original subst method, which is
  4861 still available as 'simplesubst'.
  4862 
  4863 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4864 and quasi orders.
  4865 
  4866 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4867 reflexive-transitive closure of relations.
  4868 
  4869 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4870 limit (previously hard-coded with a value of 20) user-definable.
  4871 
  4872 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4873 is peformed already.  Object-logics merely need to finish their
  4874 initial simpset configuration as before.  INCOMPATIBILITY.
  4875 
  4876 
  4877 *** HOL ***
  4878 
  4879 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4880 
  4881   syntax (epsilon)
  4882     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4883 
  4884 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4885 and x-symbol; use option '-m epsilon' to get it actually printed.
  4886 Moreover, the mathematically important symbolic identifier \<epsilon>
  4887 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4888 
  4889 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4890 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4891 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4892 support corresponding Isar calculations.
  4893 
  4894 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4895 instead of ":".
  4896 
  4897 * theory SetInterval: changed the syntax for open intervals:
  4898 
  4899   Old       New
  4900   {..n(}    {..<n}
  4901   {)n..}    {n<..}
  4902   {m..n(}   {m..<n}
  4903   {)m..n}   {m<..n}
  4904   {)m..n(}  {m<..<n}
  4905 
  4906 The old syntax is still supported but will disappear in the next
  4907 release.  For conversion use the following Emacs search and replace
  4908 patterns (these are not perfect but work quite well):
  4909 
  4910   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4911   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4912 
  4913 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4914 equalities in commutative rings; method 'algebra' provides a generic
  4915 interface.
  4916 
  4917 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4918 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4919 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4920 be a tuple pattern.
  4921 
  4922 Some new syntax forms are available:
  4923 
  4924   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4925   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4926   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4927   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4928 
  4929 The latter form "\<Sum>x < k. e" used to be based on a separate
  4930 function "Summation", which has been discontinued.
  4931 
  4932 * theory Finite_Set: in structured induction proofs, the insert case
  4933 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4934 (insert F x)'.
  4935 
  4936 * The 'refute' command has been extended to support a much larger
  4937 fragment of HOL, including axiomatic type classes, constdefs and
  4938 typedefs, inductive datatypes and recursion.
  4939 
  4940 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4941 Requires zChaff with proof generation to be installed.  See
  4942 HOL/ex/SAT_Examples.thy for examples.
  4943 
  4944 * Datatype induction via method 'induct' now preserves the name of the
  4945 induction variable. For example, when proving P(xs::'a list) by
  4946 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4947 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4948 in unstructured proof scripts.
  4949 
  4950 * Reworked implementation of records.  Improved scalability for
  4951 records with many fields, avoiding performance problems for type
  4952 inference. Records are no longer composed of nested field types, but
  4953 of nested extension types. Therefore the record type only grows linear
  4954 in the number of extensions and not in the number of fields.  The
  4955 top-level (users) view on records is preserved.  Potential
  4956 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4957 old record representation. The type generated for a record is called
  4958 <record_name>_ext_type.
  4959 
  4960 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4961 proofs triggered by a record definition or a simproc (if
  4962 quick_and_dirty is enabled).  Definitions of large records can take
  4963 quite long.
  4964 
  4965 New simproc record_upd_simproc for simplification of multiple record
  4966 updates enabled by default.  Moreover, trivial updates are also
  4967 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4968 occasionally, since simplification is more powerful by default.
  4969 
  4970 * typedef: proper support for polymorphic sets, which contain extra
  4971 type-variables in the term.
  4972 
  4973 * Simplifier: automatically reasons about transitivity chains
  4974 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4975 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4976 old proofs break occasionally as simplification may now solve more
  4977 goals than previously.
  4978 
  4979 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4980 present.  Works for all partial orders (class "order"), in particular
  4981 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4982 just like y <= x.
  4983 
  4984 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4985 bound variable or a constant then the let is unfolded.  Otherwise
  4986 first a is simplified to b, and then f b is simplified to g. If
  4987 possible we abstract b from g arriving at "let x = b in h x",
  4988 otherwise we unfold the let and arrive at g.  The simproc can be
  4989 enabled/disabled by the reference use_let_simproc.  Potential
  4990 INCOMPATIBILITY since simplification is more powerful by default.
  4991 
  4992 * Classical reasoning: the meson method now accepts theorems as arguments.
  4993 
  4994 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4995 jobs to provide advice on the provability of subgoals.
  4996 
  4997 * Theory OrderedGroup and Ring_and_Field: various additions and
  4998 improvements to faciliate calculations involving equalities and
  4999 inequalities.
  5000 
  5001 The following theorems have been eliminated or modified
  5002 (INCOMPATIBILITY):
  5003 
  5004   abs_eq             now named abs_of_nonneg
  5005   abs_of_ge_0        now named abs_of_nonneg
  5006   abs_minus_eq       now named abs_of_nonpos
  5007   imp_abs_id         now named abs_of_nonneg
  5008   imp_abs_neg_id     now named abs_of_nonpos
  5009   mult_pos           now named mult_pos_pos
  5010   mult_pos_le        now named mult_nonneg_nonneg
  5011   mult_pos_neg_le    now named mult_nonneg_nonpos
  5012   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5013   mult_neg           now named mult_neg_neg
  5014   mult_neg_le        now named mult_nonpos_nonpos
  5015 
  5016 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5017      
  5018      zero_le_square
  5019      not_square_less_zero 
  5020 
  5021   The following lemmas have been deleted from Real/RealPow:
  5022   
  5023      realpow_zero_zero
  5024      realpow_two
  5025      realpow_less
  5026      zero_le_power
  5027      realpow_two_le
  5028      abs_realpow_two
  5029      realpow_two_abs     
  5030 
  5031 * Theory Parity: added rules for simplifying exponents.
  5032 
  5033 * Theory List:
  5034 
  5035 The following theorems have been eliminated or modified
  5036 (INCOMPATIBILITY):
  5037 
  5038   list_all_Nil       now named list_all.simps(1)
  5039   list_all_Cons      now named list_all.simps(2)
  5040   list_all_conv      now named list_all_iff
  5041   set_mem_eq         now named mem_iff
  5042 
  5043 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5044 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5045 
  5046 
  5047 *** HOL-Complex ***
  5048 
  5049 * Theory RealDef: better support for embedding natural numbers and
  5050 integers in the reals.
  5051 
  5052 The following theorems have been eliminated or modified
  5053 (INCOMPATIBILITY):
  5054 
  5055   exp_ge_add_one_self  now requires no hypotheses
  5056   real_of_int_add      reversed direction of equality (use [symmetric])
  5057   real_of_int_minus    reversed direction of equality (use [symmetric])
  5058   real_of_int_diff     reversed direction of equality (use [symmetric])
  5059   real_of_int_mult     reversed direction of equality (use [symmetric])
  5060 
  5061 * Theory RComplete: expanded support for floor and ceiling functions.
  5062 
  5063 * Theory Ln is new, with properties of the natural logarithm
  5064 
  5065 * Hyperreal: There is a new type constructor "star" for making
  5066 nonstandard types.  The old type names are now type synonyms:
  5067 
  5068   hypreal = real star
  5069   hypnat = nat star
  5070   hcomplex = complex star
  5071 
  5072 * Hyperreal: Many groups of similarly-defined constants have been
  5073 replaced by polymorphic versions (INCOMPATIBILITY):
  5074 
  5075   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5076 
  5077   starset      <-- starsetNat, starsetC
  5078   *s*          <-- *sNat*, *sc*
  5079   starset_n    <-- starsetNat_n, starsetC_n
  5080   *sn*         <-- *sNatn*, *scn*
  5081   InternalSets <-- InternalNatSets, InternalCSets
  5082 
  5083   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5084   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5085   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5086   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5087   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5088 
  5089 * Hyperreal: Many type-specific theorems have been removed in favor of
  5090 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5091 
  5092   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5093   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5094   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5095   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5096   right_minus <-- hypreal_add_minus
  5097   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5098   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5099   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5100   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5101   mult_1_right <-- hcomplex_mult_one_right
  5102   mult_zero_left <-- hcomplex_mult_zero_left
  5103   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5104   right_distrib <-- hypnat_add_mult_distrib2
  5105   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5106   right_inverse <-- hypreal_mult_inverse
  5107   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5108   order_refl <-- {hypreal,hypnat}_le_refl
  5109   order_trans <-- {hypreal,hypnat}_le_trans
  5110   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5111   order_less_le <-- {hypreal,hypnat}_less_le
  5112   linorder_linear <-- {hypreal,hypnat}_le_linear
  5113   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5114   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5115   add_nonneg_nonneg <-- hypreal_le_add_order
  5116 
  5117 * Hyperreal: Separate theorems having to do with type-specific
  5118 versions of constants have been merged into theorems that apply to the
  5119 new polymorphic constants (INCOMPATIBILITY):
  5120 
  5121   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5122   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5123   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5124   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5125   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5126   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5127   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5128   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5129   STAR_diff <-- {STAR,STARC}_diff
  5130   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5131     STARC_hcomplex_of_complex}_image_subset
  5132   starset_n_Un <-- starset{Nat,C}_n_Un
  5133   starset_n_Int <-- starset{Nat,C}_n_Int
  5134   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5135   starset_n_diff <-- starset{Nat,C}_n_diff
  5136   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5137   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5138   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5139   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5140   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5141   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5142   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5143   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5144   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5145   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5146   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5147   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5148   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5149   starfun_diff <-- starfun{C,RC,CR}_diff
  5150   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5151   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5152   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5153   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5154   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5155   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5156   starfun_Id <-- starfunC_Id
  5157   starfun_approx <-- starfun{Nat,CR}_approx
  5158   starfun_capprox <-- starfun{C,RC}_capprox
  5159   starfun_abs <-- starfunNat_rabs
  5160   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5161   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5162   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5163   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5164   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5165   starfun_add_approx <-- starfunCR_add_approx
  5166   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5167   starfun_divide <-- starfun{C,CR,RC}_divide
  5168   starfun_n <-- starfun{Nat,C}_n
  5169   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5170   starfun_n_add <-- starfun{Nat,C}_n_add
  5171   starfun_n_add_minus <-- starfunNat_n_add_minus
  5172   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5173   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5174   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5175 
  5176   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5177   star_n_minus <-- {hypreal,hcomplex}_minus
  5178   star_n_diff <-- {hypreal,hcomplex}_diff
  5179   star_n_mult <-- {hypreal,hcomplex}_mult
  5180   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5181   star_n_le <-- {hypreal,hypnat}_le
  5182   star_n_less <-- {hypreal,hypnat}_less
  5183   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5184   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5185   star_n_abs <-- hypreal_hrabs
  5186   star_n_divide <-- hcomplex_divide
  5187 
  5188   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5189   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5190   star_of_diff <-- hypreal_of_real_diff
  5191   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5192   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5193   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5194   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5195   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5196   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5197   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5198   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5199   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5200   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5201   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5202   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5203   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5204   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5205   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5206   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5207   star_of_power <-- hypreal_of_real_power
  5208   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5209 
  5210 * Hyperreal: new method "transfer" that implements the transfer
  5211 principle of nonstandard analysis. With a subgoal that mentions
  5212 nonstandard types like "'a star", the command "apply transfer"
  5213 replaces it with an equivalent one that mentions only standard types.
  5214 To be successful, all free variables must have standard types; non-
  5215 standard variables must have explicit universal quantifiers.
  5216 
  5217 * Hyperreal: A theory of Taylor series.
  5218 
  5219 
  5220 *** HOLCF ***
  5221 
  5222 * Discontinued special version of 'constdefs' (which used to support
  5223 continuous functions) in favor of the general Pure one with full
  5224 type-inference.
  5225 
  5226 * New simplification procedure for solving continuity conditions; it
  5227 is much faster on terms with many nested lambda abstractions (cubic
  5228 instead of exponential time).
  5229 
  5230 * New syntax for domain package: selector names are now optional.
  5231 Parentheses should be omitted unless argument is lazy, for example:
  5232 
  5233   domain 'a stream = cons "'a" (lazy "'a stream")
  5234 
  5235 * New command 'fixrec' for defining recursive functions with pattern
  5236 matching; defining multiple functions with mutual recursion is also
  5237 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5238 sinr, or any data constructor defined by the domain package. The given
  5239 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5240 syntax and examples.
  5241 
  5242 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5243 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5244 but the proof obligation additionally includes an admissibility
  5245 requirement. The packages generate instances of class cpo or pcpo,
  5246 with continuity and strictness theorems for Rep and Abs.
  5247 
  5248 * HOLCF: Many theorems have been renamed according to a more standard naming
  5249 scheme (INCOMPATIBILITY):
  5250 
  5251   foo_inject:  "foo$x = foo$y ==> x = y"
  5252   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5253   foo_less:    "(foo$x << foo$y) = (x << y)"
  5254   foo_strict:  "foo$UU = UU"
  5255   foo_defined: "... ==> foo$x ~= UU"
  5256   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5257 
  5258 
  5259 *** ZF ***
  5260 
  5261 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5262 including the First Isomorphism Theorem (on quotienting by the kernel
  5263 of a homomorphism).
  5264 
  5265 * ZF/Simplifier: install second copy of type solver that actually
  5266 makes use of TC rules declared to Isar proof contexts (or locales);
  5267 the old version is still required for ML proof scripts.
  5268 
  5269 
  5270 *** Cube ***
  5271 
  5272 * Converted to Isar theory format; use locales instead of axiomatic
  5273 theories.
  5274 
  5275 
  5276 *** ML ***
  5277 
  5278 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5279 for ||>, ||>>, |>>,
  5280 
  5281 * Pure/library.ML no longer defines its own option datatype, but uses
  5282 that of the SML basis, which has constructors NONE and SOME instead of
  5283 None and Some, as well as exception Option.Option instead of OPTION.
  5284 The functions the, if_none, is_some, is_none have been adapted
  5285 accordingly, while Option.map replaces apsome.
  5286 
  5287 * Pure/library.ML: the exception LIST has been given up in favour of
  5288 the standard exceptions Empty and Subscript, as well as
  5289 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5290 superceded by the standard hd and tl functions etc.
  5291 
  5292 A number of basic list functions are no longer exported to the ML
  5293 toplevel, as they are variants of predefined functions.  The following
  5294 suggests how one can translate existing code:
  5295 
  5296     rev_append xs ys = List.revAppend (xs, ys)
  5297     nth_elem (i, xs) = List.nth (xs, i)
  5298     last_elem xs = List.last xs
  5299     flat xss = List.concat xss
  5300     seq fs = List.app fs
  5301     partition P xs = List.partition P xs
  5302     mapfilter f xs = List.mapPartial f xs
  5303 
  5304 * Pure/library.ML: several combinators for linear functional
  5305 transformations, notably reverse application and composition:
  5306 
  5307   x |> f                f #> g
  5308   (x, y) |-> f          f #-> g
  5309 
  5310 * Pure/library.ML: introduced/changed precedence of infix operators:
  5311 
  5312   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5313   infix 2 ?;
  5314   infix 3 o oo ooo oooo;
  5315   infix 4 ~~ upto downto;
  5316 
  5317 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5318 infix operators.
  5319 
  5320 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5321 fold_map support linear functional transformations and nesting.  For
  5322 example:
  5323 
  5324   fold f [x1, ..., xN] y =
  5325     y |> f x1 |> ... |> f xN
  5326 
  5327   (fold o fold) f [xs1, ..., xsN] y =
  5328     y |> fold f xs1 |> ... |> fold f xsN
  5329 
  5330   fold f [x1, ..., xN] =
  5331     f x1 #> ... #> f xN
  5332 
  5333   (fold o fold) f [xs1, ..., xsN] =
  5334     fold f xs1 #> ... #> fold f xsN
  5335 
  5336 * Pure/library.ML: the following selectors on type 'a option are
  5337 available:
  5338 
  5339   the:               'a option -> 'a  (*partial*)
  5340   these:             'a option -> 'a  where 'a = 'b list
  5341   the_default: 'a -> 'a option -> 'a
  5342   the_list:          'a option -> 'a list
  5343 
  5344 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5345 basic operations for association lists, following natural argument
  5346 order; moreover the explicit equality predicate passed here avoids
  5347 potentially expensive polymorphic runtime equality checks.
  5348 The old functions may be expressed as follows:
  5349 
  5350   assoc = uncurry (AList.lookup (op =))
  5351   assocs = these oo AList.lookup (op =)
  5352   overwrite = uncurry (AList.update (op =)) o swap
  5353 
  5354 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5355 
  5356   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5357   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5358 
  5359 replacing make_keylist and keyfilter (occassionally used)
  5360 Naive rewrites:
  5361 
  5362   make_keylist = AList.make
  5363   keyfilter = AList.find (op =)
  5364 
  5365 * eq_fst and eq_snd now take explicit equality parameter, thus
  5366   avoiding eqtypes. Naive rewrites:
  5367 
  5368     eq_fst = eq_fst (op =)
  5369     eq_snd = eq_snd (op =)
  5370 
  5371 * Removed deprecated apl and apr (rarely used).
  5372   Naive rewrites:
  5373 
  5374     apl (n, op) =>>= curry op n
  5375     apr (op, m) =>>= fn n => op (n, m)
  5376 
  5377 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5378 provides a reasonably efficient light-weight implementation of sets as
  5379 lists.
  5380 
  5381 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5382 few new operations; existing lookup and update are now curried to
  5383 follow natural argument order (for use with fold etc.);
  5384 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5385 
  5386 * Pure/General: output via the Isabelle channels of
  5387 writeln/warning/error etc. is now passed through Output.output, with a
  5388 hook for arbitrary transformations depending on the print_mode
  5389 (cf. Output.add_mode -- the first active mode that provides a output
  5390 function wins).  Already formatted output may be embedded into further
  5391 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5392 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5393 accommodate easy composition of diagnostic messages etc.  Programmers
  5394 rarely need to care about Output.output or Output.raw at all, with
  5395 some notable exceptions: Output.output is required when bypassing the
  5396 standard channels (writeln etc.), or in token translations to produce
  5397 properly formatted results; Output.raw is required when capturing
  5398 already output material that will eventually be presented to the user
  5399 a second time.  For the default print mode, both Output.output and
  5400 Output.raw have no effect.
  5401 
  5402 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5403 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5404 cumulative results are displayed at the end of a batch session.
  5405 
  5406 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5407 replaced by File.platform_path and File.shell_path (with appropriate
  5408 hooks).  This provides a clean interface for unusual systems where the
  5409 internal and external process view of file names are different.
  5410 
  5411 * Pure: more efficient orders for basic syntactic entities: added
  5412 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5413 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5414 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5415 orders now -- potential INCOMPATIBILITY for code that depends on a
  5416 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5417 Library.sort_strings on result).
  5418 
  5419 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5420 fold_types traverse types/terms from left to right, observing natural
  5421 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5422 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5423 
  5424 * Pure: name spaces have been refined, with significant changes of the
  5425 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5426 to extern(_table).  The plain name entry path is superceded by a
  5427 general 'naming' context, which also includes the 'policy' to produce
  5428 a fully qualified name and external accesses of a fully qualified
  5429 name; NameSpace.extend is superceded by context dependent
  5430 Sign.declare_name.  Several theory and proof context operations modify
  5431 the naming context.  Especially note Theory.restore_naming and
  5432 ProofContext.restore_naming to get back to a sane state; note that
  5433 Theory.add_path is no longer sufficient to recover from
  5434 Theory.absolute_path in particular.
  5435 
  5436 * Pure: new flags short_names (default false) and unique_names
  5437 (default true) for controlling output of qualified names.  If
  5438 short_names is set, names are printed unqualified.  If unique_names is
  5439 reset, the name prefix is reduced to the minimum required to achieve
  5440 the original result when interning again, even if there is an overlap
  5441 with earlier declarations.
  5442 
  5443 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5444 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5445 (useful for printing error messages).  INCOMPATIBILITY.
  5446 
  5447 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5448 Theory.theory are now identified, referring to the universal
  5449 Context.theory (see Pure/context.ML).  Actual signature and theory
  5450 content is managed as theory data.  The old code and interfaces were
  5451 spread over many files and structures; the new arrangement introduces
  5452 considerable INCOMPATIBILITY to gain more clarity:
  5453 
  5454   Context -- theory management operations (name, identity, inclusion,
  5455     parents, ancestors, merge, etc.), plus generic theory data;
  5456 
  5457   Sign -- logical signature and syntax operations (declaring consts,
  5458     types, etc.), plus certify/read for common entities;
  5459 
  5460   Theory -- logical theory operations (stating axioms, definitions,
  5461     oracles), plus a copy of logical signature operations (consts,
  5462     types, etc.); also a few basic management operations (Theory.copy,
  5463     Theory.merge, etc.)
  5464 
  5465 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5466 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5467 for convenience -- they merely return the theory.
  5468 
  5469 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5470 
  5471 * Pure: the Isar proof context type is already defined early in Pure
  5472 as Context.proof (note that ProofContext.context and Proof.context are
  5473 aliases, where the latter is the preferred name).  This enables other
  5474 Isabelle components to refer to that type even before Isar is present.
  5475 
  5476 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5477 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5478 any of these kinds.  For example, Sign.intern typeK is now
  5479 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5480 Theory.hide_types.  Also note that former
  5481 Theory.hide_classes/types/consts are now
  5482 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5483 internalize their arguments!  INCOMPATIBILITY.
  5484 
  5485 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5486 datatype thmref (with constructors Name and NameSelection) instead of
  5487 plain string -- INCOMPATIBILITY;
  5488 
  5489 * Pure: cases produced by proof methods specify options, where NONE
  5490 means to remove case bindings -- INCOMPATIBILITY in
  5491 (RAW_)METHOD_CASES.
  5492 
  5493 * Pure: the following operations retrieve axioms or theorems from a
  5494 theory node or theory hierarchy, respectively:
  5495 
  5496   Theory.axioms_of: theory -> (string * term) list
  5497   Theory.all_axioms_of: theory -> (string * term) list
  5498   PureThy.thms_of: theory -> (string * thm) list
  5499   PureThy.all_thms_of: theory -> (string * thm) list
  5500 
  5501 * Pure: print_tac now outputs the goal through the trace channel.
  5502 
  5503 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5504 Reference Toplevel.debug (default false) controls detailed printing
  5505 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5506 controls execution profiling -- set to 1 for time and 2 for space
  5507 (both increase the runtime).
  5508 
  5509 * Isar session: The initial use of ROOT.ML is now always timed,
  5510 i.e. the log will show the actual process times, in contrast to the
  5511 elapsed wall-clock time that the outer shell wrapper produces.
  5512 
  5513 * Simplifier: improved handling of bound variables (nameless
  5514 representation, avoid allocating new strings).  Simprocs that invoke
  5515 the Simplifier recursively should use Simplifier.inherit_bounds to
  5516 avoid local name clashes.  Failure to do so produces warnings
  5517 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5518 for further details.
  5519 
  5520 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5521 bindings for all theorems stored within a given theory; this may help
  5522 in porting non-Isar theories to Isar ones, while keeping ML proof
  5523 scripts for the time being.
  5524 
  5525 * ML operator HTML.with_charset specifies the charset begin used for
  5526 generated HTML files.  For example:
  5527 
  5528   HTML.with_charset "utf-8" use_thy "Hebrew";
  5529   HTML.with_charset "utf-8" use_thy "Chinese";
  5530 
  5531 
  5532 *** System ***
  5533 
  5534 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5535 isabelle, isatool etc.).
  5536 
  5537 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5538 isatool doc, isatool mkdir, display_drafts etc.).
  5539 
  5540 * isatool usedir: option -f allows specification of the ML file to be
  5541 used by Isabelle; default is ROOT.ML.
  5542 
  5543 * New isatool version outputs the version identifier of the Isabelle
  5544 distribution being used.
  5545 
  5546 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5547 (containing Boolean satisfiability problems) into Isabelle/HOL
  5548 theories.
  5549 
  5550 
  5551 
  5552 New in Isabelle2004 (April 2004)
  5553 --------------------------------
  5554 
  5555 *** General ***
  5556 
  5557 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5558   Replaces linorder.ML.
  5559 
  5560 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5561   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5562   (\<a>...\<z>), are now considered normal letters, and can therefore
  5563   be used anywhere where an ASCII letter (a...zA...Z) has until
  5564   now. COMPATIBILITY: This obviously changes the parsing of some
  5565   terms, especially where a symbol has been used as a binder, say
  5566   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5567   as an identifier.  Fix it by inserting a space around former
  5568   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5569   existing theory and ML files.
  5570 
  5571 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5572 
  5573 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5574   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5575   a normal (but invisible) letter. For multiple letter subscripts repeat
  5576   \<^isub> like this: x\<^isub>1\<^isub>2.
  5577 
  5578 * Pure: There are now sub-/superscripts that can span more than one
  5579   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5580   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5581   superscript. The new control characters are not identifier parts.
  5582 
  5583 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5584   content of "..." to the latex file instead of \isacntrl... . The "..."
  5585   may consist of any printable characters excluding the end bracket >.
  5586 
  5587 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5588   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5589   declare constants "final", which prevents their being given a definition
  5590   later.  It is useful for constants whose behaviour is fixed axiomatically
  5591   rather than definitionally, such as the meta-logic connectives.
  5592 
  5593 * Pure: 'instance' now handles general arities with general sorts
  5594   (i.e. intersections of classes),
  5595 
  5596 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5597   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5598   It can be changed to alter the colors/layout of generated pages.
  5599 
  5600 
  5601 *** Isar ***
  5602 
  5603 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5604   cut_tac, subgoal_tac and thin_tac:
  5605   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5606     locales are no longer forced to write Isar proof scripts.
  5607     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5608     emulations.
  5609   - INCOMPATIBILITY: names of variables to be instantiated may no
  5610     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5611     This is consistent with the instantiation attribute "where".
  5612 
  5613 * Attributes "where" and "of":
  5614   - Now take type variables of instantiated theorem into account when reading
  5615     the instantiation string.  This fixes a bug that caused instantiated
  5616     theorems to have too special types in some circumstances.
  5617   - "where" permits explicit instantiations of type variables.
  5618 
  5619 * Calculation commands "moreover" and "also" no longer interfere with
  5620   current facts ("this"), admitting arbitrary combinations with "then"
  5621   and derived forms.
  5622 
  5623 * Locales:
  5624   - Goal statements involving the context element "includes" no longer
  5625     generate theorems with internal delta predicates (those ending on
  5626     "_axioms") in the premise.
  5627     Resolve particular premise with <locale>.intro to obtain old form.
  5628   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5629     specification and "includes" elements in goal statement.
  5630   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5631     [intro?] and [elim?] (respectively) by default.
  5632   - Experimental command for instantiation of locales in proof contexts:
  5633         instantiate <label>[<attrs>]: <loc>
  5634     Instantiates locale <loc> and adds all its theorems to the current context
  5635     taking into account their attributes.  Label and attrs are optional
  5636     modifiers, like in theorem declarations.  If present, names of
  5637     instantiated theorems are qualified with <label>, and the attributes
  5638     <attrs> are applied after any attributes these theorems might have already.
  5639       If the locale has assumptions, a chained fact of the form
  5640     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5641     are derived.  The command does not support old-style locales declared
  5642     with "locale (open)".
  5643       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5644 
  5645 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5646   (Isar) contexts.
  5647 
  5648 
  5649 *** HOL ***
  5650 
  5651 * Proof import: new image HOL4 contains the imported library from
  5652   the HOL4 system with about 2500 theorems. It is imported by
  5653   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5654   can be used like any other Isabelle image.  See
  5655   HOL/Import/HOL/README for more information.
  5656 
  5657 * Simplifier:
  5658   - Much improved handling of linear and partial orders.
  5659     Reasoners for linear and partial orders are set up for type classes
  5660     "linorder" and "order" respectively, and are added to the default simpset
  5661     as solvers.  This means that the simplifier can build transitivity chains
  5662     to solve goals from the assumptions.
  5663   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5664     of blast or auto after simplification become unnecessary because the goal
  5665     is solved by simplification already.
  5666 
  5667 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5668     all proved in axiomatic type classes for semirings, rings and fields.
  5669 
  5670 * Numerics:
  5671   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5672     now formalized using the Ring_and_Field theory mentioned above.
  5673   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5674     than before, because now they are set up once in a generic manner.
  5675   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5676     Look for the general versions in Ring_and_Field (and Power if they concern
  5677     exponentiation).
  5678 
  5679 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5680 
  5681 * Records:
  5682   - Record types are now by default printed with their type abbreviation
  5683     instead of the list of all field types. This can be configured via
  5684     the reference "print_record_type_abbr".
  5685   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5686     (not enabled by default).
  5687   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5688     EX x. x = sel r to True (not enabled by default).
  5689   - Tactic "record_split_simp_tac" to split and simplify records added.
  5690 
  5691 * 'specification' command added, allowing for definition by
  5692   specification.  There is also an 'ax_specification' command that
  5693   introduces the new constants axiomatically.
  5694 
  5695 * arith(_tac) is now able to generate counterexamples for reals as well.
  5696 
  5697 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5698 
  5699 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5700   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5701 
  5702 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5703   matrix theory to linear programming.
  5704 
  5705 * Unions and Intersections:
  5706   The latex output syntax of UN and INT has been changed
  5707   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5708   i.e. the index formulae has become a subscript.
  5709   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5710 
  5711 * Unions and Intersections over Intervals:
  5712   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5713   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5714   like in normal math, and corresponding versions for < and for intersection.
  5715 
  5716 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5717   lexicographic dictonary ordering has been added as "lexord".
  5718 
  5719 * ML: the legacy theory structures Int and List have been removed. They had
  5720   conflicted with ML Basis Library structures having the same names.
  5721 
  5722 * 'refute' command added to search for (finite) countermodels.  Only works
  5723   for a fragment of HOL.  The installation of an external SAT solver is
  5724   highly recommended.  See "HOL/Refute.thy" for details.
  5725 
  5726 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5727   formulae under an assignment of free variables to random values.
  5728   In contrast to 'refute', it can deal with inductive datatypes,
  5729   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5730   for examples.
  5731 
  5732 
  5733 *** HOLCF ***
  5734 
  5735 * Streams now come with concatenation and are part of the HOLCF image
  5736 
  5737 
  5738 
  5739 New in Isabelle2003 (May 2003)
  5740 ------------------------------
  5741 
  5742 *** General ***
  5743 
  5744 * Provers/simplifier:
  5745 
  5746   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5747     Assumptions are now subject to complete mutual simplification,
  5748     not just from left to right. The simplifier now preserves
  5749     the order of assumptions.
  5750 
  5751     Potential INCOMPATIBILITY:
  5752 
  5753     -- simp sometimes diverges where the old version did
  5754        not, e.g. invoking simp on the goal
  5755 
  5756         [| P (f x); y = x; f x = f y |] ==> Q
  5757 
  5758        now gives rise to the infinite reduction sequence
  5759 
  5760         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5761 
  5762        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5763        kind of problem.
  5764 
  5765     -- Tactics combining classical reasoner and simplification (such as auto)
  5766        are also affected by this change, because many of them rely on
  5767        simp. They may sometimes diverge as well or yield a different numbers
  5768        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5769        in case of problems. Sometimes subsequent calls to the classical
  5770        reasoner will fail because a preceeding call to the simplifier too
  5771        eagerly simplified the goal, e.g. deleted redundant premises.
  5772 
  5773   - The simplifier trace now shows the names of the applied rewrite rules
  5774 
  5775   - You can limit the number of recursive invocations of the simplifier
  5776     during conditional rewriting (where the simplifie tries to solve the
  5777     conditions before applying the rewrite rule):
  5778     ML "simp_depth_limit := n"
  5779     where n is an integer. Thus you can force termination where previously
  5780     the simplifier would diverge.
  5781 
  5782   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5783 
  5784   - No longer aborts on failed congruence proof.  Instead, the
  5785     congruence is ignored.
  5786 
  5787 * Pure: New generic framework for extracting programs from constructive
  5788   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5789   as HOL/Extraction for some case studies.
  5790 
  5791 * Pure: The main goal of the proof state is no longer shown by default, only
  5792 the subgoals. This behaviour is controlled by a new flag.
  5793    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5794 (ML: Proof.show_main_goal).
  5795 
  5796 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5797 rules whose conclusion matches subgoal 1:
  5798       PG menu: Isabelle/Isar -> Show me -> matching rules
  5799 The rules are ordered by how closely they match the subgoal.
  5800 In particular, rules that solve a subgoal outright are displayed first
  5801 (or rather last, the way they are printed).
  5802 (ML: ProofGeneral.print_intros())
  5803 
  5804 * Pure: New flag trace_unify_fail causes unification to print
  5805 diagnostic information (PG: in trace buffer) when it fails. This is
  5806 useful for figuring out why single step proofs like rule, erule or
  5807 assumption failed.
  5808 
  5809 * Pure: Locale specifications now produce predicate definitions
  5810 according to the body of text (covering assumptions modulo local
  5811 definitions); predicate "loc_axioms" covers newly introduced text,
  5812 while "loc" is cumulative wrt. all included locale expressions; the
  5813 latter view is presented only on export into the global theory
  5814 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5815 on the old view without predicates;
  5816 
  5817 * Pure: predefined locales "var" and "struct" are useful for sharing
  5818 parameters (as in CASL, for example); just specify something like
  5819 ``var x + var y + struct M'' as import;
  5820 
  5821 * Pure: improved thms_containing: proper indexing of facts instead of
  5822 raw theorems; check validity of results wrt. current name space;
  5823 include local facts of proof configuration (also covers active
  5824 locales), cover fixed variables in index; may use "_" in term
  5825 specification; an optional limit for the number of printed facts may
  5826 be given (the default is 40);
  5827 
  5828 * Pure: disallow duplicate fact bindings within new-style theory files
  5829 (batch-mode only);
  5830 
  5831 * Provers: improved induct method: assumptions introduced by case
  5832 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5833 the goal statement); "foo" still refers to all facts collectively;
  5834 
  5835 * Provers: the function blast.overloaded has been removed: all constants
  5836 are regarded as potentially overloaded, which improves robustness in exchange
  5837 for slight decrease in efficiency;
  5838 
  5839 * Provers/linorder: New generic prover for transitivity reasoning over
  5840 linear orders.  Note: this prover is not efficient!
  5841 
  5842 * Isar: preview of problems to finish 'show' now produce an error
  5843 rather than just a warning (in interactive mode);
  5844 
  5845 
  5846 *** HOL ***
  5847 
  5848 * arith(_tac)
  5849 
  5850  - Produces a counter example if it cannot prove a goal.
  5851    Note that the counter example may be spurious if the goal is not a formula
  5852    of quantifier-free linear arithmetic.
  5853    In ProofGeneral the counter example appears in the trace buffer.
  5854 
  5855  - Knows about div k and mod k where k is a numeral of type nat or int.
  5856 
  5857  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5858    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5859    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5860 
  5861 * simp's arithmetic capabilities have been enhanced a bit: it now
  5862 takes ~= in premises into account (by performing a case split);
  5863 
  5864 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5865 are distributed over a sum of terms;
  5866 
  5867 * New tactic "trans_tac" and method "trans" instantiate
  5868 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5869 "<=", "<" and "=").
  5870 
  5871 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5872 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5873 
  5874 * 'typedef' command has new option "open" to suppress the set
  5875 definition;
  5876 
  5877 * functions Min and Max on finite sets have been introduced (theory
  5878 Finite_Set);
  5879 
  5880 * attribute [symmetric] now works for relations as well; it turns
  5881 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5882 
  5883 * induct over a !!-quantified statement (say !!x1..xn):
  5884   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5885 
  5886 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5887 %x. None. Warning: empty_def now refers to the previously hidden definition
  5888 of the empty set.
  5889 
  5890 * Algebra: formalization of classical algebra.  Intended as base for
  5891 any algebraic development in Isabelle.  Currently covers group theory
  5892 (up to Sylow's theorem) and ring theory (Universal Property of
  5893 Univariate Polynomials).  Contributions welcome;
  5894 
  5895 * GroupTheory: deleted, since its material has been moved to Algebra;
  5896 
  5897 * Complex: new directory of the complex numbers with numeric constants,
  5898 nonstandard complex numbers, and some complex analysis, standard and
  5899 nonstandard (Jacques Fleuriot);
  5900 
  5901 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5902 
  5903 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5904 Fleuriot);
  5905 
  5906 * Real/HahnBanach: updated and adapted to locales;
  5907 
  5908 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5909 Gray and Kramer);
  5910 
  5911 * UNITY: added the Meier-Sanders theory of progress sets;
  5912 
  5913 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5914 as abstract algorithms, instantiated to the JVM;
  5915 
  5916 * Bali: Java source language formalization. Type system, operational
  5917 semantics, axiomatic semantics. Supported language features:
  5918 classes, interfaces, objects,virtual methods, static methods,
  5919 static/instance fields, arrays, access modifiers, definite
  5920 assignment, exceptions.
  5921 
  5922 
  5923 *** ZF ***
  5924 
  5925 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5926 universe, etc.);
  5927 
  5928 * Main ZF: virtually all theories converted to new-style format;
  5929 
  5930 
  5931 *** ML ***
  5932 
  5933 * Pure: Tactic.prove provides sane interface for internal proofs;
  5934 omits the infamous "standard" operation, so this is more appropriate
  5935 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5936 
  5937 * Pure: improved error reporting of simprocs;
  5938 
  5939 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5940 up simprocs;
  5941 
  5942 
  5943 *** Document preparation ***
  5944 
  5945 * uses \par instead of \\ for line breaks in theory text. This may
  5946 shift some page breaks in large documents. To get the old behaviour
  5947 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5948 
  5949 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5950 other packages
  5951 
  5952 * \<euro> now needs package babel/greek instead of marvosym (which
  5953 broke \Rightarrow)
  5954 
  5955 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5956 textcomp package)
  5957 
  5958 
  5959 
  5960 New in Isabelle2002 (March 2002)
  5961 --------------------------------
  5962 
  5963 *** Document preparation ***
  5964 
  5965 * greatly simplified document preparation setup, including more
  5966 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5967 instructive isatool mkdir; users should basically be able to get
  5968 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5969 users may run a separate document processing stage manually like this:
  5970 "isatool usedir -D output HOL Test && isatool document Test/output";
  5971 
  5972 * theory dependency graph may now be incorporated into documents;
  5973 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5974 with \includegraphics of LaTeX;
  5975 
  5976 * proper spacing of consecutive markup elements, especially text
  5977 blocks after section headings;
  5978 
  5979 * support bold style (for single symbols only), input syntax is like
  5980 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5981 
  5982 * \<bullet> is now output as bold \cdot by default, which looks much
  5983 better in printed text;
  5984 
  5985 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5986 note that these symbols are currently unavailable in Proof General /
  5987 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5988 
  5989 * isatool latex no longer depends on changed TEXINPUTS, instead
  5990 isatool document copies the Isabelle style files to the target
  5991 location;
  5992 
  5993 
  5994 *** Isar ***
  5995 
  5996 * Pure/Provers: improved proof by cases and induction;
  5997   - 'case' command admits impromptu naming of parameters (such as
  5998     "case (Suc n)");
  5999   - 'induct' method divinates rule instantiation from the inductive
  6000     claim; no longer requires excessive ?P bindings for proper
  6001     instantiation of cases;
  6002   - 'induct' method properly enumerates all possibilities of set/type
  6003     rules; as a consequence facts may be also passed through *type*
  6004     rules without further ado;
  6005   - 'induct' method now derives symbolic cases from the *rulified*
  6006     rule (before it used to rulify cases stemming from the internal
  6007     atomized version); this means that the context of a non-atomic
  6008     statement becomes is included in the hypothesis, avoiding the
  6009     slightly cumbersome show "PROP ?case" form;
  6010   - 'induct' may now use elim-style induction rules without chaining
  6011     facts, using ``missing'' premises from the goal state; this allows
  6012     rules stemming from inductive sets to be applied in unstructured
  6013     scripts, while still benefitting from proper handling of non-atomic
  6014     statements; NB: major inductive premises need to be put first, all
  6015     the rest of the goal is passed through the induction;
  6016   - 'induct' proper support for mutual induction involving non-atomic
  6017     rule statements (uses the new concept of simultaneous goals, see
  6018     below);
  6019   - append all possible rule selections, but only use the first
  6020     success (no backtracking);
  6021   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6022   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6023   - added 'print_induct_rules' (covered by help item in recent Proof
  6024     General versions);
  6025   - moved induct/cases attributes to Pure, methods to Provers;
  6026   - generic method setup instantiated for FOL and HOL;
  6027 
  6028 * Pure: support multiple simultaneous goal statements, for example
  6029 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6030 meta-level mechanism, this acts as if several individual goals had
  6031 been stated separately; in particular common proof methods need to be
  6032 repeated in order to cover all claims; note that a single elimination
  6033 step is *not* sufficient to establish the two conjunctions, so this
  6034 fails:
  6035 
  6036   assume "A & B" then have A and B ..   (*".." fails*)
  6037 
  6038 better use "obtain" in situations as above; alternative refer to
  6039 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6040 
  6041 * Pure: proper integration with ``locales''; unlike the original
  6042 version by Florian Kammller, Isar locales package high-level proof
  6043 contexts rather than raw logical ones (e.g. we admit to include
  6044 attributes everywhere); operations on locales include merge and
  6045 rename; support for implicit arguments (``structures''); simultaneous
  6046 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6047 some examples;
  6048 
  6049 * Pure: the following commands have been ``localized'', supporting a
  6050 target locale specification "(in name)": 'lemma', 'theorem',
  6051 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6052 stored both within the locale and at the theory level (exported and
  6053 qualified by the locale name);
  6054 
  6055 * Pure: theory goals may now be specified in ``long'' form, with
  6056 ad-hoc contexts consisting of arbitrary locale elements. for example
  6057 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6058 definitions may be given, too); the result is a meta-level rule with
  6059 the context elements being discharged in the obvious way;
  6060 
  6061 * Pure: new proof command 'using' allows to augment currently used
  6062 facts after a goal statement ('using' is syntactically analogous to
  6063 'apply', but acts on the goal's facts only); this allows chained facts
  6064 to be separated into parts given before and after a claim, as in
  6065 ``from a and b have C using d and e <proof>'';
  6066 
  6067 * Pure: renamed "antecedent" case to "rule_context";
  6068 
  6069 * Pure: new 'judgment' command records explicit information about the
  6070 object-logic embedding (used by several tools internally); no longer
  6071 use hard-wired "Trueprop";
  6072 
  6073 * Pure: added 'corollary' command;
  6074 
  6075 * Pure: fixed 'token_translation' command;
  6076 
  6077 * Pure: removed obsolete 'exported' attribute;
  6078 
  6079 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6080 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6081 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6082 
  6083 * Pure: method 'atomize' presents local goal premises as object-level
  6084 statements (atomic meta-level propositions); setup controlled via
  6085 rewrite rules declarations of 'atomize' attribute; example
  6086 application: 'induct' method with proper rule statements in improper
  6087 proof *scripts*;
  6088 
  6089 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6090 now consider the syntactic context of assumptions, giving a better
  6091 chance to get type-inference of the arguments right (this is
  6092 especially important for locales);
  6093 
  6094 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6095 mode;
  6096 
  6097 * Pure/obtain: the formal conclusion "thesis", being marked as
  6098 ``internal'', may no longer be reference directly in the text;
  6099 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6100 situations;
  6101 
  6102 * Pure: generic 'sym' attribute which declares a rule both as pure
  6103 'elim?' and for the 'symmetric' operation;
  6104 
  6105 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6106 text; the fixed correlation with particular command syntax has been
  6107 discontinued;
  6108 
  6109 * Pure: new method 'rules' is particularly well-suited for proof
  6110 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6111 but often produces more compact proof terms with less detours;
  6112 
  6113 * Pure/Provers/classical: simplified integration with pure rule
  6114 attributes and methods; the classical "intro?/elim?/dest?"
  6115 declarations coincide with the pure ones; the "rule" method no longer
  6116 includes classically swapped intros; "intro" and "elim" methods no
  6117 longer pick rules from the context; also got rid of ML declarations
  6118 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6119 INCOMPATIBILITY;
  6120 
  6121 * Provers/classical: attribute 'swapped' produces classical inversions
  6122 of introduction rules;
  6123 
  6124 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6125 rules instead of full simplifier context; 'iff' attribute handles
  6126 conditional rules;
  6127 
  6128 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6129 
  6130 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6131 "(permissive)" option to recover old behavior;
  6132 
  6133 * HOL: 'inductive' no longer features separate (collective) attributes
  6134 for 'intros' (was found too confusing);
  6135 
  6136 * HOL: properly declared induction rules less_induct and
  6137 wf_induct_rule;
  6138 
  6139 
  6140 *** HOL ***
  6141 
  6142 * HOL: moved over to sane numeral syntax; the new policy is as
  6143 follows:
  6144 
  6145   - 0 and 1 are polymorphic constants, which are defined on any
  6146   numeric type (nat, int, real etc.);
  6147 
  6148   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6149   binary representation internally;
  6150 
  6151   - type nat has special constructor Suc, and generally prefers Suc 0
  6152   over 1::nat and Suc (Suc 0) over 2::nat;
  6153 
  6154 This change may cause significant problems of INCOMPATIBILITY; here
  6155 are some hints on converting existing sources:
  6156 
  6157   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6158   entities, so expressions involving "-" (unary or binary minus) need
  6159   to be spaced properly;
  6160 
  6161   - existing occurrences of "1" may need to be constraint "1::nat" or
  6162   even replaced by Suc 0; similar for old "2";
  6163 
  6164   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6165 
  6166   - remove all special provisions on numerals in proofs;
  6167 
  6168 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6169 representation (depends on bin_arith_simps in the default context);
  6170 
  6171 * HOL: symbolic syntax for x^2 (numeral 2);
  6172 
  6173 * HOL: the class of all HOL types is now called "type" rather than
  6174 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6175 in axclass/classes, instance/arities, and (usually rare) occurrences
  6176 in typings (of consts etc.); internally the class is called
  6177 "HOL.type", ML programs should refer to HOLogic.typeS;
  6178 
  6179 * HOL/record package improvements:
  6180   - new derived operations "fields" to build a partial record section,
  6181     "extend" to promote a fixed record to a record scheme, and
  6182     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6183     declared as simp by default;
  6184   - shared operations ("more", "fields", etc.) now need to be always
  6185     qualified) --- potential INCOMPATIBILITY;
  6186   - removed "make_scheme" operations (use "make" with "extend") --
  6187     INCOMPATIBILITY;
  6188   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6189   - provides cases/induct rules for use with corresponding Isar
  6190     methods (for concrete records, record schemes, concrete more
  6191     parts, and schematic more parts -- in that order);
  6192   - internal definitions directly based on a light-weight abstract
  6193     theory of product types over typedef rather than datatype;
  6194 
  6195 * HOL: generic code generator for generating executable ML code from
  6196 specifications; specific support for HOL constructs such as inductive
  6197 datatypes and sets, as well as recursive functions; can be invoked
  6198 via 'generate_code' theory section;
  6199 
  6200 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6201 
  6202 * HOL: consolidated and renamed several theories.  In particular:
  6203         Ord.thy has been absorbed into HOL.thy
  6204         String.thy has been absorbed into List.thy
  6205 
  6206 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6207 (beware of argument permutation!);
  6208 
  6209 * HOL: linorder_less_split superseded by linorder_cases;
  6210 
  6211 * HOL/List: "nodups" renamed to "distinct";
  6212 
  6213 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6214 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6215   - Ex_def has changed, now need to use some_eq_ex
  6216 
  6217 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6218 in this (rare) case use:
  6219 
  6220   delSWrapper "split_all_tac"
  6221   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6222 
  6223 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6224 MAY FAIL;
  6225 
  6226 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6227 Isabelle's type classes, ^ on functions and relations has too general
  6228 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6229 necessary to attach explicit type constraints;
  6230