NEWS
author wenzelm
Tue Apr 19 15:58:05 2011 +0200 (2011-04-19)
changeset 42403 38b29c9fc742
parent 42370 244911efd275
child 42484 2777a27506d0
permissions -rw-r--r--
slightly more special eq_list/eq_set, with shortcut involving pointer_eq;
     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 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   116 goal states; body tactic needs to address all subgoals uniformly.
   117 
   118 * Slightly more special eq_list/eq_set, with shortcut involving
   119 pointer equality (assumes that eq relation is reflexive).
   120 
   121 
   122 
   123 New in Isabelle2011 (January 2011)
   124 ----------------------------------
   125 
   126 *** General ***
   127 
   128 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   129 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   130 useful tooltips and hyperlinks produced from its static analysis.  The
   131 bundled component provides an executable Isabelle tool that can be run
   132 like this:
   133 
   134   Isabelle2011/bin/isabelle jedit
   135 
   136 * Significantly improved Isabelle/Isar implementation manual.
   137 
   138 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   139 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   140 while the default heap location within that directory lacks that extra
   141 suffix.  This isolates multiple Isabelle installations from each
   142 other, avoiding problems with old settings in new versions.
   143 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   144 
   145 * Source files are always encoded as UTF-8, instead of old-fashioned
   146 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   147 the following package declarations:
   148 
   149   \usepackage[utf8]{inputenc}
   150   \usepackage{textcomp}
   151 
   152 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   153 a Unicode character is treated as a single symbol, not a sequence of
   154 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   155 contain symbols without further backslash escapes, Unicode can now be
   156 used here as well.  Recall that Symbol.explode in ML provides a
   157 consistent view on symbols, while raw explode (or String.explode)
   158 merely give a byte-oriented representation.
   159 
   160 * Theory loader: source files are primarily located via the master
   161 directory of each theory node (where the .thy file itself resides).
   162 The global load path is still partially available as legacy feature.
   163 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   164 explicit paths, relatively to the theory.
   165 
   166 * Special treatment of ML file names has been discontinued.
   167 Historically, optional extensions .ML or .sml were added on demand --
   168 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   169 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   170 
   171 * Various options that affect pretty printing etc. are now properly
   172 handled within the context via configuration options, instead of
   173 unsynchronized references or print modes.  There are both ML Config.T
   174 entities and Isar declaration attributes to access these.
   175 
   176   ML (Config.T)                 Isar (attribute)
   177 
   178   eta_contract                  eta_contract
   179   show_brackets                 show_brackets
   180   show_sorts                    show_sorts
   181   show_types                    show_types
   182   show_question_marks           show_question_marks
   183   show_consts                   show_consts
   184   show_abbrevs                  show_abbrevs
   185 
   186   Syntax.ast_trace              syntax_ast_trace
   187   Syntax.ast_stat               syntax_ast_stat
   188   Syntax.ambiguity_level        syntax_ambiguity_level
   189 
   190   Goal_Display.goals_limit      goals_limit
   191   Goal_Display.show_main_goal   show_main_goal
   192 
   193   Method.rule_trace             rule_trace
   194 
   195   Thy_Output.display            thy_output_display
   196   Thy_Output.quotes             thy_output_quotes
   197   Thy_Output.indent             thy_output_indent
   198   Thy_Output.source             thy_output_source
   199   Thy_Output.break              thy_output_break
   200 
   201 Note that corresponding "..._default" references in ML may only be
   202 changed globally at the ROOT session setup, but *not* within a theory.
   203 The option "show_abbrevs" supersedes the former print mode
   204 "no_abbrevs" with inverted meaning.
   205 
   206 * More systematic naming of some configuration options.
   207 INCOMPATIBILITY.
   208 
   209   trace_simp  ~>  simp_trace
   210   debug_simp  ~>  simp_debug
   211 
   212 * Support for real valued configuration options, using simplistic
   213 floating-point notation that coincides with the inner syntax for
   214 float_token.
   215 
   216 * Support for real valued preferences (with approximative PGIP type):
   217 front-ends need to accept "pgint" values in float notation.
   218 INCOMPATIBILITY.
   219 
   220 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   221 DejaVu Sans.
   222 
   223 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   224 
   225 
   226 *** Pure ***
   227 
   228 * Command 'type_synonym' (with single argument) replaces somewhat
   229 outdated 'types', which is still available as legacy feature for some
   230 time.
   231 
   232 * Command 'nonterminal' (with 'and' separated list of arguments)
   233 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   234 
   235 * Command 'notepad' replaces former 'example_proof' for
   236 experimentation in Isar without any result.  INCOMPATIBILITY.
   237 
   238 * Locale interpretation commands 'interpret' and 'sublocale' accept
   239 lists of equations to map definitions in a locale to appropriate
   240 entities in the context of the interpretation.  The 'interpretation'
   241 command already provided this functionality.
   242 
   243 * Diagnostic command 'print_dependencies' prints the locale instances
   244 that would be activated if the specified expression was interpreted in
   245 the current context.  Variant "print_dependencies!" assumes a context
   246 without interpretations.
   247 
   248 * Diagnostic command 'print_interps' prints interpretations in proofs
   249 in addition to interpretations in theories.
   250 
   251 * Discontinued obsolete 'global' and 'local' commands to manipulate
   252 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   253 Sign.root_path and Sign.local_path may be applied directly where this
   254 feature is still required for historical reasons.
   255 
   256 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   257 'definition' instead.
   258 
   259 * The "prems" fact, which refers to the accidental collection of
   260 foundational premises in the context, is now explicitly marked as
   261 legacy feature and will be discontinued soon.  Consider using "assms"
   262 of the head statement or reference facts by explicit names.
   263 
   264 * Document antiquotations @{class} and @{type} print classes and type
   265 constructors.
   266 
   267 * Document antiquotation @{file} checks file/directory entries within
   268 the local file system.
   269 
   270 
   271 *** HOL ***
   272 
   273 * Coercive subtyping: functions can be declared as coercions and type
   274 inference will add them as necessary upon input of a term.  Theory
   275 Complex_Main declares real :: nat => real and real :: int => real as
   276 coercions. A coercion function f is declared like this:
   277 
   278   declare [[coercion f]]
   279 
   280 To lift coercions through type constructors (e.g. from nat => real to
   281 nat list => real list), map functions can be declared, e.g.
   282 
   283   declare [[coercion_map map]]
   284 
   285 Currently coercion inference is activated only in theories including
   286 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   287 the configuration option "coercion_enabled", e.g. it can be enabled in
   288 other theories like this:
   289 
   290   declare [[coercion_enabled]]
   291 
   292 * Command 'partial_function' provides basic support for recursive
   293 function definitions over complete partial orders.  Concrete instances
   294 are provided for i) the option type, ii) tail recursion on arbitrary
   295 types, and iii) the heap monad of Imperative_HOL.  See
   296 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   297 for examples.
   298 
   299 * Function package: f.psimps rules are no longer implicitly declared
   300 as [simp].  INCOMPATIBILITY.
   301 
   302 * Datatype package: theorems generated for executable equality (class
   303 "eq") carry proper names and are treated as default code equations.
   304 
   305 * Inductive package: now offers command 'inductive_simps' to
   306 automatically derive instantiated and simplified equations for
   307 inductive predicates, similar to 'inductive_cases'.
   308 
   309 * Command 'enriched_type' allows to register properties of the
   310 functorial structure of types.
   311 
   312 * Improved infrastructure for term evaluation using code generator
   313 techniques, in particular static evaluation conversions.
   314 
   315 * Code generator: Scala (2.8 or higher) has been added to the target
   316 languages.
   317 
   318 * Code generator: globbing constant expressions "*" and "Theory.*"
   319 have been replaced by the more idiomatic "_" and "Theory._".
   320 INCOMPATIBILITY.
   321 
   322 * Code generator: export_code without explicit file declaration prints
   323 to standard output.  INCOMPATIBILITY.
   324 
   325 * Code generator: do not print function definitions for case
   326 combinators any longer.
   327 
   328 * Code generator: simplification with rules determined with
   329 src/Tools/Code/code_simp.ML and method "code_simp".
   330 
   331 * Code generator for records: more idiomatic representation of record
   332 types.  Warning: records are not covered by ancient SML code
   333 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   334 rep_datatype declaration helps to succeed then:
   335 
   336   record 'a foo = ...
   337   ...
   338   rep_datatype foo_ext ...
   339 
   340 * Records: logical foundation type for records does not carry a
   341 '_type' suffix any longer (obsolete due to authentic syntax).
   342 INCOMPATIBILITY.
   343 
   344 * Quickcheck now by default uses exhaustive testing instead of random
   345 testing.  Random testing can be invoked by "quickcheck [random]",
   346 exhaustive testing by "quickcheck [exhaustive]".
   347 
   348 * Quickcheck instantiates polymorphic types with small finite
   349 datatypes by default. This enables a simple execution mechanism to
   350 handle quantifiers and function equality over the finite datatypes.
   351 
   352 * Quickcheck random generator has been renamed from "code" to
   353 "random".  INCOMPATIBILITY.
   354 
   355 * Quickcheck now has a configurable time limit which is set to 30
   356 seconds by default. This can be changed by adding [timeout = n] to the
   357 quickcheck command. The time limit for Auto Quickcheck is still set
   358 independently.
   359 
   360 * Quickcheck in locales considers interpretations of that locale for
   361 counter example search.
   362 
   363 * Sledgehammer:
   364   - Added "smt" and "remote_smt" provers based on the "smt" proof
   365     method. See the Sledgehammer manual for details ("isabelle doc
   366     sledgehammer").
   367   - Renamed commands:
   368     sledgehammer atp_info ~> sledgehammer running_provers
   369     sledgehammer atp_kill ~> sledgehammer kill_provers
   370     sledgehammer available_atps ~> sledgehammer available_provers
   371     INCOMPATIBILITY.
   372   - Renamed options:
   373     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   374     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   375     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   376     (and "ms" and "min" are no longer supported)
   377     INCOMPATIBILITY.
   378 
   379 * Nitpick:
   380   - Renamed options:
   381     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   382     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   383     INCOMPATIBILITY.
   384   - Added support for partial quotient types.
   385   - Added local versions of the "Nitpick.register_xxx" functions.
   386   - Added "whack" option.
   387   - Allow registration of quotient types as codatatypes.
   388   - Improved "merge_type_vars" option to merge more types.
   389   - Removed unsound "fast_descrs" option.
   390   - Added custom symmetry breaking for datatypes, making it possible to reach
   391     higher cardinalities.
   392   - Prevent the expansion of too large definitions.
   393 
   394 * Proof methods "metis" and "meson" now have configuration options
   395 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   396 to diagnose these tools. E.g.
   397 
   398     using [[metis_trace = true]]
   399 
   400 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   401 manually as command 'solve_direct'.
   402 
   403 * The default SMT solver Z3 must be enabled explicitly (due to
   404 licensing issues) by setting the environment variable
   405 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   406 commercial applications, the SMT solver CVC3 is provided as fall-back;
   407 changing the SMT solver is done via the configuration option
   408 "smt_solver".
   409 
   410 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   411 i.e. "remote_cvc3" and "remote_z3".
   412 
   413 * Added basic SMT support for datatypes, records, and typedefs using
   414 the oracle mode (no proofs).  Direct support of pairs has been dropped
   415 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   416 support for a similar behavior).  Minor INCOMPATIBILITY.
   417 
   418 * Changed SMT configuration options:
   419   - Renamed:
   420     z3_proofs ~> smt_oracle (with inverted meaning)
   421     z3_trace_assms ~> smt_trace_used_facts
   422     INCOMPATIBILITY.
   423   - Added:
   424     smt_verbose
   425     smt_random_seed
   426     smt_datatypes
   427     smt_infer_triggers
   428     smt_monomorph_limit
   429     cvc3_options
   430     remote_cvc3_options
   431     remote_z3_options
   432     yices_options
   433 
   434 * Boogie output files (.b2i files) need to be declared in the theory
   435 header.
   436 
   437 * Simplification procedure "list_to_set_comprehension" rewrites list
   438 comprehensions applied to List.set to set comprehensions.  Occasional
   439 INCOMPATIBILITY, may be deactivated like this:
   440 
   441   declare [[simproc del: list_to_set_comprehension]]
   442 
   443 * Removed old version of primrec package.  INCOMPATIBILITY.
   444 
   445 * Removed simplifier congruence rule of "prod_case", as has for long
   446 been the case with "split".  INCOMPATIBILITY.
   447 
   448 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   449 
   450 * Removed [split_format ... and ... and ...] version of
   451 [split_format].  Potential INCOMPATIBILITY.
   452 
   453 * Predicate "sorted" now defined inductively, with nice induction
   454 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   455 
   456 * Constant "contents" renamed to "the_elem", to free the generic name
   457 contents for other uses.  INCOMPATIBILITY.
   458 
   459 * Renamed class eq and constant eq (for code generation) to class
   460 equal and constant equal, plus renaming of related facts and various
   461 tuning.  INCOMPATIBILITY.
   462 
   463 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   464 
   465 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   466 INCOMPATIBILITY.
   467 
   468 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   469 avoid confusion with finite sets.  INCOMPATIBILITY.
   470 
   471 * Abandoned locales equiv, congruent and congruent2 for equivalence
   472 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   473 for congruent(2)).
   474 
   475 * Some previously unqualified names have been qualified:
   476 
   477   types
   478     bool ~> HOL.bool
   479     nat ~> Nat.nat
   480 
   481   constants
   482     Trueprop ~> HOL.Trueprop
   483     True ~> HOL.True
   484     False ~> HOL.False
   485     op & ~> HOL.conj
   486     op | ~> HOL.disj
   487     op --> ~> HOL.implies
   488     op = ~> HOL.eq
   489     Not ~> HOL.Not
   490     The ~> HOL.The
   491     All ~> HOL.All
   492     Ex ~> HOL.Ex
   493     Ex1 ~> HOL.Ex1
   494     Let ~> HOL.Let
   495     If ~> HOL.If
   496     Ball ~> Set.Ball
   497     Bex ~> Set.Bex
   498     Suc ~> Nat.Suc
   499     Pair ~> Product_Type.Pair
   500     fst ~> Product_Type.fst
   501     snd ~> Product_Type.snd
   502     curry ~> Product_Type.curry
   503     op : ~> Set.member
   504     Collect ~> Set.Collect
   505 
   506 INCOMPATIBILITY.
   507 
   508 * More canonical naming convention for some fundamental definitions:
   509 
   510     bot_bool_eq ~> bot_bool_def
   511     top_bool_eq ~> top_bool_def
   512     inf_bool_eq ~> inf_bool_def
   513     sup_bool_eq ~> sup_bool_def
   514     bot_fun_eq  ~> bot_fun_def
   515     top_fun_eq  ~> top_fun_def
   516     inf_fun_eq  ~> inf_fun_def
   517     sup_fun_eq  ~> sup_fun_def
   518 
   519 INCOMPATIBILITY.
   520 
   521 * More stylized fact names:
   522 
   523   expand_fun_eq ~> fun_eq_iff
   524   expand_set_eq ~> set_eq_iff
   525   set_ext       ~> set_eqI
   526   nat_number    ~> eval_nat_numeral
   527 
   528 INCOMPATIBILITY.
   529 
   530 * Refactoring of code-generation specific operations in theory List:
   531 
   532   constants
   533     null ~> List.null
   534 
   535   facts
   536     mem_iff ~> member_def
   537     null_empty ~> null_def
   538 
   539 INCOMPATIBILITY.  Note that these were not supposed to be used
   540 regularly unless for striking reasons; their main purpose was code
   541 generation.
   542 
   543 Various operations from the Haskell prelude are used for generating
   544 Haskell code.
   545 
   546 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   547 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   548 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   549 
   550 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   551 "*" and "+" respectively.  INCOMPATIBILITY.
   552 
   553 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   554 "Sum_Type.Plus" instead.
   555 
   556 * Constant "split" has been merged with constant "prod_case"; names of
   557 ML functions, facts etc. involving split have been retained so far,
   558 though.  INCOMPATIBILITY.
   559 
   560 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   561 instead.  INCOMPATIBILITY.
   562 
   563 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   564 INCOMPATIBILITY.
   565 
   566 * Former theory Library/Enum is now part of the HOL-Main image.
   567 INCOMPATIBILITY: all constants of the Enum theory now have to be
   568 referred to by its qualified name.
   569 
   570   enum    ~>  Enum.enum
   571   nlists  ~>  Enum.nlists
   572   product ~>  Enum.product
   573 
   574 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   575 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   576 INCOMPATIBILITY.
   577 
   578 * Theory Library/SetsAndFunctions has been split into
   579 Library/Function_Algebras and Library/Set_Algebras; canonical names
   580 for instance definitions for functions; various improvements.
   581 INCOMPATIBILITY.
   582 
   583 * Theory Library/Multiset provides stable quicksort implementation of
   584 sort_key.
   585 
   586 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   587 INCOMPATIBILITY.
   588 
   589 * Session Multivariate_Analysis: introduced a type class for euclidean
   590 space.  Most theorems are now stated in terms of euclidean spaces
   591 instead of finite cartesian products.
   592 
   593   types
   594     real ^ 'n ~>  'a::real_vector
   595               ~>  'a::euclidean_space
   596               ~>  'a::ordered_euclidean_space
   597         (depends on your needs)
   598 
   599   constants
   600      _ $ _        ~> _ $$ _
   601      \<chi> x. _  ~> \<chi>\<chi> x. _
   602      CARD('n)     ~> DIM('a)
   603 
   604 Also note that the indices are now natural numbers and not from some
   605 finite type. Finite cartesian products of euclidean spaces, products
   606 of euclidean spaces the real and complex numbers are instantiated to
   607 be euclidean_spaces.  INCOMPATIBILITY.
   608 
   609 * Session Probability: introduced pextreal as positive extended real
   610 numbers.  Use pextreal as value for measures.  Introduce the
   611 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   612 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   613 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   614 
   615 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   616 INCOMPATIBILITY.
   617 
   618 * Session SPARK (with image HOL-SPARK) provides commands to load and
   619 prove verification conditions generated by the SPARK Ada program
   620 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   621 
   622 
   623 *** HOL-Algebra ***
   624 
   625 * Theorems for additive ring operations (locale abelian_monoid and
   626 descendants) are generated by interpretation from their multiplicative
   627 counterparts.  Names (in particular theorem names) have the mandatory
   628 qualifier 'add'.  Previous theorem names are redeclared for
   629 compatibility.
   630 
   631 * Structure "int_ring" is now an abbreviation (previously a
   632 definition).  This fits more natural with advanced interpretations.
   633 
   634 
   635 *** HOLCF ***
   636 
   637 * The domain package now runs in definitional mode by default: The
   638 former command 'new_domain' is now called 'domain'.  To use the domain
   639 package in its original axiomatic mode, use 'domain (unsafe)'.
   640 INCOMPATIBILITY.
   641 
   642 * The new class "domain" is now the default sort.  Class "predomain"
   643 is an unpointed version of "domain". Theories can be updated by
   644 replacing sort annotations as shown below.  INCOMPATIBILITY.
   645 
   646   'a::type ~> 'a::countable
   647   'a::cpo  ~> 'a::predomain
   648   'a::pcpo ~> 'a::domain
   649 
   650 * The old type class "rep" has been superseded by class "domain".
   651 Accordingly, users of the definitional package must remove any
   652 "default_sort rep" declarations.  INCOMPATIBILITY.
   653 
   654 * The domain package (definitional mode) now supports unpointed
   655 predomain argument types, as long as they are marked 'lazy'. (Strict
   656 arguments must be in class "domain".) For example, the following
   657 domain definition now works:
   658 
   659   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   660 
   661 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   662 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   663 'a option, and 'a list.  Additionally, it configures fixrec and the
   664 domain package to work with these types.  For example:
   665 
   666   fixrec isInl :: "('a + 'b) u -> tr"
   667     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   668 
   669   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   670 
   671 * The "(permissive)" option of fixrec has been replaced with a
   672 per-equation "(unchecked)" option. See
   673 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   674 
   675 * The "bifinite" class no longer fixes a constant "approx"; the class
   676 now just asserts that such a function exists.  INCOMPATIBILITY.
   677 
   678 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   679 defines an embedding of type 'a defl into udom by default; instances
   680 of "bifinite" and "domain" classes are available in
   681 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   682 
   683 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   684 
   685 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   686 
   687 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   688 
   689 * The function "cprod_map" has been renamed to "prod_map".
   690 INCOMPATIBILITY.
   691 
   692 * The monadic bind operator on each powerdomain has new binder syntax
   693 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   694 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   695 
   696 * The infix syntax for binary union on each powerdomain has changed
   697 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   698 syntax.  INCOMPATIBILITY.
   699 
   700 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   701 still supported as an input translation.
   702 
   703 * Renamed some theorems (the original names are also still available).
   704 
   705   expand_fun_below   ~> fun_below_iff
   706   below_fun_ext      ~> fun_belowI
   707   expand_cfun_eq     ~> cfun_eq_iff
   708   ext_cfun           ~> cfun_eqI
   709   expand_cfun_below  ~> cfun_below_iff
   710   below_cfun_ext     ~> cfun_belowI
   711   cont2cont_Rep_CFun ~> cont2cont_APP
   712 
   713 * The Abs and Rep functions for various types have changed names.
   714 Related theorem names have also changed to match. INCOMPATIBILITY.
   715 
   716   Rep_CFun  ~> Rep_cfun
   717   Abs_CFun  ~> Abs_cfun
   718   Rep_Sprod ~> Rep_sprod
   719   Abs_Sprod ~> Abs_sprod
   720   Rep_Ssum  ~> Rep_ssum
   721   Abs_Ssum  ~> Abs_ssum
   722 
   723 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   724 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   725 
   726 * Various changes to bisimulation/coinduction with domain package:
   727 
   728   - Definitions of "bisim" constants no longer mention definedness.
   729   - With mutual recursion, "bisim" predicate is now curried.
   730   - With mutual recursion, each type gets a separate coind theorem.
   731   - Variable names in bisim_def and coinduct rules have changed.
   732 
   733 INCOMPATIBILITY.
   734 
   735 * Case combinators generated by the domain package for type "foo" are
   736 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   737 
   738 * Several theorems have been renamed to more accurately reflect the
   739 names of constants and types involved.  INCOMPATIBILITY.
   740 
   741   thelub_const    ~> lub_const
   742   lub_const       ~> is_lub_const
   743   thelubI         ~> lub_eqI
   744   is_lub_lub      ~> is_lubD2
   745   lubI            ~> is_lub_lub
   746   unique_lub      ~> is_lub_unique
   747   is_ub_lub       ~> is_lub_rangeD1
   748   lub_bin_chain   ~> is_lub_bin_chain
   749   lub_fun         ~> is_lub_fun
   750   thelub_fun      ~> lub_fun
   751   thelub_cfun     ~> lub_cfun
   752   thelub_Pair     ~> lub_Pair
   753   lub_cprod       ~> is_lub_prod
   754   thelub_cprod    ~> lub_prod
   755   minimal_cprod   ~> minimal_prod
   756   inst_cprod_pcpo ~> inst_prod_pcpo
   757   UU_I            ~> bottomI
   758   compact_UU      ~> compact_bottom
   759   deflation_UU    ~> deflation_bottom
   760   finite_deflation_UU ~> finite_deflation_bottom
   761 
   762 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   763 
   764   sq_ord_less_eq_trans ~> below_eq_trans
   765   sq_ord_eq_less_trans ~> eq_below_trans
   766   refl_less            ~> below_refl
   767   trans_less           ~> below_trans
   768   antisym_less         ~> below_antisym
   769   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   770   box_less             ~> box_below
   771   rev_trans_less       ~> rev_below_trans
   772   not_less2not_eq      ~> not_below2not_eq
   773   less_UU_iff          ~> below_UU_iff
   774   flat_less_iff        ~> flat_below_iff
   775   adm_less             ~> adm_below
   776   adm_not_less         ~> adm_not_below
   777   adm_compact_not_less ~> adm_compact_not_below
   778   less_fun_def         ~> below_fun_def
   779   expand_fun_less      ~> fun_below_iff
   780   less_fun_ext         ~> fun_belowI
   781   less_discr_def       ~> below_discr_def
   782   discr_less_eq        ~> discr_below_eq
   783   less_unit_def        ~> below_unit_def
   784   less_cprod_def       ~> below_prod_def
   785   prod_lessI           ~> prod_belowI
   786   Pair_less_iff        ~> Pair_below_iff
   787   fst_less_iff         ~> fst_below_iff
   788   snd_less_iff         ~> snd_below_iff
   789   expand_cfun_less     ~> cfun_below_iff
   790   less_cfun_ext        ~> cfun_belowI
   791   injection_less       ~> injection_below
   792   less_up_def          ~> below_up_def
   793   not_Iup_less         ~> not_Iup_below
   794   Iup_less             ~> Iup_below
   795   up_less              ~> up_below
   796   Def_inject_less_eq   ~> Def_below_Def
   797   Def_less_is_eq       ~> Def_below_iff
   798   spair_less_iff       ~> spair_below_iff
   799   less_sprod           ~> below_sprod
   800   spair_less           ~> spair_below
   801   sfst_less_iff        ~> sfst_below_iff
   802   ssnd_less_iff        ~> ssnd_below_iff
   803   fix_least_less       ~> fix_least_below
   804   dist_less_one        ~> dist_below_one
   805   less_ONE             ~> below_ONE
   806   ONE_less_iff         ~> ONE_below_iff
   807   less_sinlD           ~> below_sinlD
   808   less_sinrD           ~> below_sinrD
   809 
   810 
   811 *** FOL and ZF ***
   812 
   813 * All constant names are now qualified internally and use proper
   814 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   815 
   816 
   817 *** ML ***
   818 
   819 * Antiquotation @{assert} inlines a function bool -> unit that raises
   820 Fail if the argument is false.  Due to inlining the source position of
   821 failed assertions is included in the error output.
   822 
   823 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   824 text is in practice always evaluated with a stable theory checkpoint.
   825 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   826 
   827 * Antiquotation @{theory A} refers to theory A from the ancestry of
   828 the current context, not any accidental theory loader state as before.
   829 Potential INCOMPATIBILITY, subtle change in semantics.
   830 
   831 * Syntax.pretty_priority (default 0) configures the required priority
   832 of pretty-printed output and thus affects insertion of parentheses.
   833 
   834 * Syntax.default_root (default "any") configures the inner syntax
   835 category (nonterminal symbol) for parsing of terms.
   836 
   837 * Former exception Library.UnequalLengths now coincides with
   838 ListPair.UnequalLengths.
   839 
   840 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   841 main functionality is provided by structure Simplifier.
   842 
   843 * Renamed raw "explode" function to "raw_explode" to emphasize its
   844 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   845 almost all situations.
   846 
   847 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   848 See implementation manual for further details on exceptions in
   849 Isabelle/ML.
   850 
   851 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   852 meaning.
   853 
   854 * Renamed structure PureThy to Pure_Thy and moved most of its
   855 operations to structure Global_Theory, to emphasize that this is
   856 rarely-used global-only stuff.
   857 
   858 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   859 instead (or tracing for high-volume output).
   860 
   861 * Configuration option show_question_marks only affects regular pretty
   862 printing of types and terms, not raw Term.string_of_vname.
   863 
   864 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   865 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   866 @{thms} for most purposes.
   867 
   868 * ML structure Unsynchronized is never opened, not even in Isar
   869 interaction mode as before.  Old Unsynchronized.set etc. have been
   870 discontinued -- use plain := instead.  This should be *rare* anyway,
   871 since modern tools always work via official context data, notably
   872 configuration options.
   873 
   874 * Parallel and asynchronous execution requires special care concerning
   875 interrupts.  Structure Exn provides some convenience functions that
   876 avoid working directly with raw Interrupt.  User code must not absorb
   877 interrupts -- intermediate handling (for cleanup etc.) needs to be
   878 followed by re-raising of the original exception.  Another common
   879 source of mistakes are "handle _" patterns, which make the meaning of
   880 the program subject to physical effects of the environment.
   881 
   882 
   883 
   884 New in Isabelle2009-2 (June 2010)
   885 ---------------------------------
   886 
   887 *** General ***
   888 
   889 * Authentic syntax for *all* logical entities (type classes, type
   890 constructors, term constants): provides simple and robust
   891 correspondence between formal entities and concrete syntax.  Within
   892 the parse tree / AST representations, "constants" are decorated by
   893 their category (class, type, const) and spelled out explicitly with
   894 their full internal name.
   895 
   896 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   897 and translations (translation rules and translation functions in ML).
   898 Some hints on upgrading:
   899 
   900   - Many existing uses of 'syntax' and 'translations' can be replaced
   901     by more modern 'type_notation', 'notation' and 'abbreviation',
   902     which are independent of this issue.
   903 
   904   - 'translations' require markup within the AST; the term syntax
   905     provides the following special forms:
   906 
   907       CONST c   -- produces syntax version of constant c from context
   908       XCONST c  -- literally c, checked as constant from context
   909       c         -- literally c, if declared by 'syntax'
   910 
   911     Plain identifiers are treated as AST variables -- occasionally the
   912     system indicates accidental variables via the error "rhs contains
   913     extra variables".
   914 
   915     Type classes and type constructors are marked according to their
   916     concrete syntax.  Some old translations rules need to be written
   917     for the "type" category, using type constructor application
   918     instead of pseudo-term application of the default category
   919     "logic".
   920 
   921   - 'parse_translation' etc. in ML may use the following
   922     antiquotations:
   923 
   924       @{class_syntax c}   -- type class c within parse tree / AST
   925       @{term_syntax c}    -- type constructor c within parse tree / AST
   926       @{const_syntax c}   -- ML version of "CONST c" above
   927       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   928 
   929   - Literal types within 'typed_print_translations', i.e. those *not*
   930     represented as pseudo-terms are represented verbatim.  Use @{class
   931     c} or @{type_name c} here instead of the above syntax
   932     antiquotations.
   933 
   934 Note that old non-authentic syntax was based on unqualified base
   935 names, so all of the above "constant" names would coincide.  Recall
   936 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   937 diagnose syntax problems.
   938 
   939 * Type constructors admit general mixfix syntax, not just infix.
   940 
   941 * Concrete syntax may be attached to local entities without a proof
   942 body, too.  This works via regular mixfix annotations for 'fix',
   943 'def', 'obtain' etc. or via the explicit 'write' command, which is
   944 similar to the 'notation' command in theory specifications.
   945 
   946 * Discontinued unnamed infix syntax (legacy feature for many years) --
   947 need to specify constant name and syntax separately.  Internal ML
   948 datatype constructors have been renamed from InfixName to Infix etc.
   949 Minor INCOMPATIBILITY.
   950 
   951 * Schematic theorem statements need to be explicitly markup as such,
   952 via commands 'schematic_lemma', 'schematic_theorem',
   953 'schematic_corollary'.  Thus the relevance of the proof is made
   954 syntactically clear, which impacts performance in a parallel or
   955 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   956 
   957 * Use of cumulative prems via "!" in some proof methods has been
   958 discontinued (old legacy feature).
   959 
   960 * References 'trace_simp' and 'debug_simp' have been replaced by
   961 configuration options stored in the context. Enabling tracing (the
   962 case of debugging is similar) in proofs works via
   963 
   964   using [[trace_simp = true]]
   965 
   966 Tracing is then active for all invocations of the simplifier in
   967 subsequent goal refinement steps. Tracing may also still be enabled or
   968 disabled via the ProofGeneral settings menu.
   969 
   970 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   971 'hide_fact' replace the former 'hide' KIND command.  Minor
   972 INCOMPATIBILITY.
   973 
   974 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   975 more efficient than combinations with -q1 or -q2.
   976 
   977 
   978 *** Pure ***
   979 
   980 * Proofterms record type-class reasoning explicitly, using the
   981 "unconstrain" operation internally.  This eliminates all sort
   982 constraints from a theorem and proof, introducing explicit
   983 OFCLASS-premises.  On the proof term level, this operation is
   984 automatically applied at theorem boundaries, such that closed proofs
   985 are always free of sort constraints.  INCOMPATIBILITY for tools that
   986 inspect proof terms.
   987 
   988 * Local theory specifications may depend on extra type variables that
   989 are not present in the result type -- arguments TYPE('a) :: 'a itself
   990 are added internally.  For example:
   991 
   992   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   993 
   994 * Predicates of locales introduced by classes carry a mandatory
   995 "class" prefix.  INCOMPATIBILITY.
   996 
   997 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   998 
   999 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1000 'class' instead.
  1001 
  1002 * Command 'code_reflect' allows to incorporate generated ML code into
  1003 runtime environment; replaces immature code_datatype antiquotation.
  1004 INCOMPATIBILITY.
  1005 
  1006 * Code generator: simple concept for abstract datatypes obeying
  1007 invariants.
  1008 
  1009 * Code generator: details of internal data cache have no impact on the
  1010 user space functionality any longer.
  1011 
  1012 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1013 subgoals.  This is more appropriate for interpretations with 'where'.
  1014 INCOMPATIBILITY.
  1015 
  1016 * Command 'example_proof' opens an empty proof body.  This allows to
  1017 experiment with Isar, without producing any persistent result.
  1018 
  1019 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1020 within a local theory context, with explicit checking of the
  1021 constructors involved (in contrast to the raw 'syntax' versions).
  1022 
  1023 * Commands 'types' and 'typedecl' now work within a local theory
  1024 context -- without introducing dependencies on parameters or
  1025 assumptions, which is not possible in Isabelle/Pure.
  1026 
  1027 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1028 within a local theory context.  Minor INCOMPATIBILITY.
  1029 
  1030 
  1031 *** HOL ***
  1032 
  1033 * Command 'typedef' now works within a local theory context -- without
  1034 introducing dependencies on parameters or assumptions, which is not
  1035 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1036 contain multiple interpretations of local typedefs (with different
  1037 non-emptiness proofs), even in a global theory context.
  1038 
  1039 * New package for quotient types.  Commands 'quotient_type' and
  1040 'quotient_definition' may be used for defining types and constants by
  1041 quotient constructions.  An example is the type of integers created by
  1042 quotienting pairs of natural numbers:
  1043 
  1044   fun
  1045     intrel :: "(nat * nat) => (nat * nat) => bool"
  1046   where
  1047     "intrel (x, y) (u, v) = (x + v = u + y)"
  1048 
  1049   quotient_type int = "nat * nat" / intrel
  1050     by (auto simp add: equivp_def expand_fun_eq)
  1051 
  1052   quotient_definition
  1053     "0::int" is "(0::nat, 0::nat)"
  1054 
  1055 The method "lifting" can be used to lift of theorems from the
  1056 underlying "raw" type to the quotient type.  The example
  1057 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1058 construction and provides a reasoning infrastructure for finite sets.
  1059 
  1060 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1061 clash with new theory Quotient in Main HOL.
  1062 
  1063 * Moved the SMT binding into the main HOL session, eliminating
  1064 separate HOL-SMT session.
  1065 
  1066 * List membership infix mem operation is only an input abbreviation.
  1067 INCOMPATIBILITY.
  1068 
  1069 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1070 for future developements; former Library/Word.thy is still present in
  1071 the AFP entry RSAPPS.
  1072 
  1073 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1074 longer shadowed.  INCOMPATIBILITY.
  1075 
  1076 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1077 INCOMPATIBILITY.
  1078 
  1079 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1080 INCOMPATIBILITY.
  1081 
  1082 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1083 instead.  INCOMPATIBILITY.
  1084 
  1085 * Dropped several real-specific versions of lemmas about floor and
  1086 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1087 instead.  INCOMPATIBILITY.
  1088 
  1089   floor_number_of_eq         ~> floor_number_of
  1090   le_floor_eq_number_of      ~> number_of_le_floor
  1091   le_floor_eq_zero           ~> zero_le_floor
  1092   le_floor_eq_one            ~> one_le_floor
  1093   floor_less_eq_number_of    ~> floor_less_number_of
  1094   floor_less_eq_zero         ~> floor_less_zero
  1095   floor_less_eq_one          ~> floor_less_one
  1096   less_floor_eq_number_of    ~> number_of_less_floor
  1097   less_floor_eq_zero         ~> zero_less_floor
  1098   less_floor_eq_one          ~> one_less_floor
  1099   floor_le_eq_number_of      ~> floor_le_number_of
  1100   floor_le_eq_zero           ~> floor_le_zero
  1101   floor_le_eq_one            ~> floor_le_one
  1102   floor_subtract_number_of   ~> floor_diff_number_of
  1103   floor_subtract_one         ~> floor_diff_one
  1104   ceiling_number_of_eq       ~> ceiling_number_of
  1105   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1106   ceiling_le_zero_eq         ~> ceiling_le_zero
  1107   ceiling_le_eq_one          ~> ceiling_le_one
  1108   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1109   less_ceiling_eq_zero       ~> zero_less_ceiling
  1110   less_ceiling_eq_one        ~> one_less_ceiling
  1111   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1112   ceiling_less_eq_zero       ~> ceiling_less_zero
  1113   ceiling_less_eq_one        ~> ceiling_less_one
  1114   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1115   le_ceiling_eq_zero         ~> zero_le_ceiling
  1116   le_ceiling_eq_one          ~> one_le_ceiling
  1117   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1118   ceiling_subtract_one       ~> ceiling_diff_one
  1119 
  1120 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1121 application of the various fold combinators on finite sets.
  1122 
  1123 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1124 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1125 implementation.  INCOMPATIBILTY.
  1126 
  1127 * Theory Library/Coinductive_List has been removed -- superseded by
  1128 AFP/thys/Coinductive.
  1129 
  1130 * Theory PReal, including the type "preal" and related operations, has
  1131 been removed.  INCOMPATIBILITY.
  1132 
  1133 * Real: new development using Cauchy Sequences.
  1134 
  1135 * Split off theory "Big_Operators" containing setsum, setprod,
  1136 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1137 
  1138 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1139 "Int" etc.  INCOMPATIBILITY.
  1140 
  1141 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1142 
  1143 * New set of rules "ac_simps" provides combined assoc / commute
  1144 rewrites for all interpretations of the appropriate generic locales.
  1145 
  1146 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1147 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1148 appropriate and more consistent names suitable for name prefixes
  1149 within the HOL theories.  INCOMPATIBILITY.
  1150 
  1151 * Some generic constants have been put to appropriate theories:
  1152   - less_eq, less: Orderings
  1153   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1154   - inverse, divide: Rings
  1155 INCOMPATIBILITY.
  1156 
  1157 * More consistent naming of type classes involving orderings (and
  1158 lattices):
  1159 
  1160     lower_semilattice                   ~> semilattice_inf
  1161     upper_semilattice                   ~> semilattice_sup
  1162 
  1163     dense_linear_order                  ~> dense_linorder
  1164 
  1165     pordered_ab_group_add               ~> ordered_ab_group_add
  1166     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1167     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1168     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1169     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1170     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1171     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1172     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1173     pordered_comm_ring                  ~> ordered_comm_ring
  1174     pordered_comm_semiring              ~> ordered_comm_semiring
  1175     pordered_ring                       ~> ordered_ring
  1176     pordered_ring_abs                   ~> ordered_ring_abs
  1177     pordered_semiring                   ~> ordered_semiring
  1178 
  1179     ordered_ab_group_add                ~> linordered_ab_group_add
  1180     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1181     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1182     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1183     ordered_field                       ~> linordered_field
  1184     ordered_field_no_lb                 ~> linordered_field_no_lb
  1185     ordered_field_no_ub                 ~> linordered_field_no_ub
  1186     ordered_field_dense_linear_order    ~> dense_linordered_field
  1187     ordered_idom                        ~> linordered_idom
  1188     ordered_ring                        ~> linordered_ring
  1189     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1190     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1191     ordered_ring_strict                 ~> linordered_ring_strict
  1192     ordered_semidom                     ~> linordered_semidom
  1193     ordered_semiring                    ~> linordered_semiring
  1194     ordered_semiring_1                  ~> linordered_semiring_1
  1195     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1196     ordered_semiring_strict             ~> linordered_semiring_strict
  1197 
  1198   The following slightly odd type classes have been moved to a
  1199   separate theory Library/Lattice_Algebras:
  1200 
  1201     lordered_ab_group_add               ~> lattice_ab_group_add
  1202     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1203     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1204     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1205     lordered_ring                       ~> lattice_ring
  1206 
  1207 INCOMPATIBILITY.
  1208 
  1209 * Refined field classes:
  1210   - classes division_ring_inverse_zero, field_inverse_zero,
  1211     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1212     subsumes former division_by_zero class;
  1213   - numerous lemmas have been ported from field to division_ring.
  1214 INCOMPATIBILITY.
  1215 
  1216 * Refined algebra theorem collections:
  1217   - dropped theorem group group_simps, use algebra_simps instead;
  1218   - dropped theorem group ring_simps, use field_simps instead;
  1219   - proper theorem collection field_simps subsumes former theorem
  1220     groups field_eq_simps and field_simps;
  1221   - dropped lemma eq_minus_self_iff which is a duplicate for
  1222     equal_neg_zero.
  1223 INCOMPATIBILITY.
  1224 
  1225 * Theory Finite_Set and List: some lemmas have been generalized from
  1226 sets to lattices:
  1227 
  1228   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1229   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1230   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1231   union_Union_fold_union        ~> sup_Sup_fold_sup
  1232   Inter_fold_inter              ~> Inf_fold_inf
  1233   Union_fold_union              ~> Sup_fold_sup
  1234   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1235   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1236   INTER_fold_inter              ~> INFI_fold_inf
  1237   UNION_fold_union              ~> SUPR_fold_sup
  1238 
  1239 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1240 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1241 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1242 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1243 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1244 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1245 
  1246 * Reorganized theory Multiset: swapped notation of pointwise and
  1247 multiset order:
  1248 
  1249   - pointwise ordering is instance of class order with standard syntax
  1250     <= and <;
  1251   - multiset ordering has syntax <=# and <#; partial order properties
  1252     are provided by means of interpretation with prefix
  1253     multiset_order;
  1254   - less duplication, less historical organization of sections,
  1255     conversion from associations lists to multisets, rudimentary code
  1256     generation;
  1257   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1258     if needed.
  1259 
  1260 Renamed:
  1261 
  1262   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1263   multi_count_ext  ~>  multiset_ext
  1264   diff_union_inverse2  ~>  diff_union_cancelR
  1265 
  1266 INCOMPATIBILITY.
  1267 
  1268 * Theory Permutation: replaced local "remove" by List.remove1.
  1269 
  1270 * Code generation: ML and OCaml code is decorated with signatures.
  1271 
  1272 * Theory List: added transpose.
  1273 
  1274 * Library/Nat_Bijection.thy is a collection of bijective functions
  1275 between nat and other types, which supersedes the older libraries
  1276 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1277 
  1278   Constants:
  1279   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1280   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1281   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1282   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1283   Countable.pair_encode           ~> prod_encode
  1284   NatIso.prod2nat                 ~> prod_encode
  1285   NatIso.nat2prod                 ~> prod_decode
  1286   NatIso.sum2nat                  ~> sum_encode
  1287   NatIso.nat2sum                  ~> sum_decode
  1288   NatIso.list2nat                 ~> list_encode
  1289   NatIso.nat2list                 ~> list_decode
  1290   NatIso.set2nat                  ~> set_encode
  1291   NatIso.nat2set                  ~> set_decode
  1292 
  1293   Lemmas:
  1294   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1295   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1296   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1297   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1298   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1299   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1300   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1301   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1302   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1303   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1304   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1305   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1306   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1307 
  1308 * Sledgehammer:
  1309   - Renamed ATP commands:
  1310     atp_info     ~> sledgehammer running_atps
  1311     atp_kill     ~> sledgehammer kill_atps
  1312     atp_messages ~> sledgehammer messages
  1313     atp_minimize ~> sledgehammer minimize
  1314     print_atps   ~> sledgehammer available_atps
  1315     INCOMPATIBILITY.
  1316   - Added user's manual ("isabelle doc sledgehammer").
  1317   - Added option syntax and "sledgehammer_params" to customize
  1318     Sledgehammer's behavior.  See the manual for details.
  1319   - Modified the Isar proof reconstruction code so that it produces
  1320     direct proofs rather than proofs by contradiction.  (This feature
  1321     is still experimental.)
  1322   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1323     full-typed mode.
  1324   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1325 
  1326 * Nitpick:
  1327   - Added and implemented "binary_ints" and "bits" options.
  1328   - Added "std" option and implemented support for nonstandard models.
  1329   - Added and implemented "finitize" option to improve the precision
  1330     of infinite datatypes based on a monotonicity analysis.
  1331   - Added support for quotient types.
  1332   - Added support for "specification" and "ax_specification"
  1333     constructs.
  1334   - Added support for local definitions (for "function" and
  1335     "termination" proofs).
  1336   - Added support for term postprocessors.
  1337   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1338   - Improved efficiency of "destroy_constrs" optimization.
  1339   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1340     record getters.
  1341   - Fixed soundness bug related to higher-order constructors.
  1342   - Fixed soundness bug when "full_descrs" is enabled.
  1343   - Improved precision of set constructs.
  1344   - Added "atoms" option.
  1345   - Added cache to speed up repeated Kodkod invocations on the same
  1346     problems.
  1347   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1348     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1349     "SAT4J_Light".  INCOMPATIBILITY.
  1350   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1351     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1352   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1353 
  1354 * Method "induct" now takes instantiations of the form t, where t is not
  1355   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1356   If this is not intended, t has to be enclosed in parentheses.
  1357   By default, the equalities generated by definitional instantiations
  1358   are pre-simplified, which may cause parameters of inductive cases
  1359   to disappear, or may even delete some of the inductive cases.
  1360   Use "induct (no_simp)" instead of "induct" to restore the old
  1361   behaviour. The (no_simp) option is also understood by the "cases"
  1362   and "nominal_induct" methods, which now perform pre-simplification, too.
  1363   INCOMPATIBILITY.
  1364 
  1365 
  1366 *** HOLCF ***
  1367 
  1368 * Variable names in lemmas generated by the domain package have
  1369 changed; the naming scheme is now consistent with the HOL datatype
  1370 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1371 
  1372 * The domain package no longer defines the function "foo_copy" for
  1373 recursive domain "foo".  The reach lemma is now stated directly in
  1374 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1375 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1376 
  1377 * Most definedness lemmas generated by the domain package (previously
  1378 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1379 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1380 Proofs that used definedness lemmas as intro rules may break,
  1381 potential INCOMPATIBILITY.
  1382 
  1383 * Induction and casedist rules generated by the domain package now
  1384 declare proper case_names (one called "bottom", and one named for each
  1385 constructor).  INCOMPATIBILITY.
  1386 
  1387 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1388 rules are generated for each domain, INCOMPATIBILITY.
  1389 
  1390   foo_bar.reach       ~> foo.reach  bar.reach
  1391   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1392 
  1393 * Some lemmas generated by the domain package have been renamed for
  1394 consistency with the datatype package, INCOMPATIBILITY.
  1395 
  1396   foo.ind        ~> foo.induct
  1397   foo.finite_ind ~> foo.finite_induct
  1398   foo.coind      ~> foo.coinduct
  1399   foo.casedist   ~> foo.exhaust
  1400   foo.exhaust    ~> foo.nchotomy
  1401 
  1402 * For consistency with other definition packages, the fixrec package
  1403 now generates qualified theorem names, INCOMPATIBILITY.
  1404 
  1405   foo_simps  ~> foo.simps
  1406   foo_unfold ~> foo.unfold
  1407   foo_induct ~> foo.induct
  1408 
  1409 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1410 method and internal fixrec proofs now use the default simpset instead.
  1411 INCOMPATIBILITY.
  1412 
  1413 * The "contlub" predicate has been removed.  Proof scripts should use
  1414 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1415 
  1416 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1417 
  1418 * The constants cpair, cfst, and csnd have been removed in favor of
  1419 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1420 
  1421 
  1422 *** ML ***
  1423 
  1424 * Antiquotations for basic formal entities:
  1425 
  1426     @{class NAME}         -- type class
  1427     @{class_syntax NAME}  -- syntax representation of the above
  1428 
  1429     @{type_name NAME}     -- logical type
  1430     @{type_abbrev NAME}   -- type abbreviation
  1431     @{nonterminal NAME}   -- type of concrete syntactic category
  1432     @{type_syntax NAME}   -- syntax representation of any of the above
  1433 
  1434     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1435     @{const_abbrev NAME}  -- abbreviated constant
  1436     @{const_syntax NAME}  -- syntax representation of any of the above
  1437 
  1438 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1439 syntax constant (cf. 'syntax' command).
  1440 
  1441 * Antiquotation @{make_string} inlines a function to print arbitrary
  1442 values similar to the ML toplevel.  The result is compiler dependent
  1443 and may fall back on "?" in certain situations.
  1444 
  1445 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1446 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1447 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1448 not work with the asynchronous Isar document model.
  1449 
  1450 * Configuration options now admit dynamic default values, depending on
  1451 the context or even global references.
  1452 
  1453 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1454 uses an efficient external library if available (for Poly/ML).
  1455 
  1456 * Renamed some important ML structures, while keeping the old names
  1457 for some time as aliases within the structure Legacy:
  1458 
  1459   OuterKeyword  ~>  Keyword
  1460   OuterLex      ~>  Token
  1461   OuterParse    ~>  Parse
  1462   OuterSyntax   ~>  Outer_Syntax
  1463   PrintMode     ~>  Print_Mode
  1464   SpecParse     ~>  Parse_Spec
  1465   ThyInfo       ~>  Thy_Info
  1466   ThyLoad       ~>  Thy_Load
  1467   ThyOutput     ~>  Thy_Output
  1468   TypeInfer     ~>  Type_Infer
  1469 
  1470 Note that "open Legacy" simplifies porting of sources, but forgetting
  1471 to remove it again will complicate porting again in the future.
  1472 
  1473 * Most operations that refer to a global context are named
  1474 accordingly, e.g. Simplifier.global_context or
  1475 ProofContext.init_global.  There are some situations where a global
  1476 context actually works, but under normal circumstances one needs to
  1477 pass the proper local context through the code!
  1478 
  1479 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1480 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1481 Pretty.pp argument to merge, which is absent in the standard
  1482 Theory_Data version.
  1483 
  1484 * Sorts.certify_sort and derived "cert" operations for types and terms
  1485 no longer minimize sorts.  Thus certification at the boundary of the
  1486 inference kernel becomes invariant under addition of class relations,
  1487 which is an important monotonicity principle.  Sorts are now minimized
  1488 in the syntax layer only, at the boundary between the end-user and the
  1489 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1490 explicitly in rare situations.
  1491 
  1492 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1493 emphasize that this is in no way a standard operation.
  1494 INCOMPATIBILITY.
  1495 
  1496 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1497 usual for resolution.  Rare INCOMPATIBILITY.
  1498 
  1499 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1500 to emphasize that these only work in a global situation (which is
  1501 quite rare).
  1502 
  1503 * Curried take and drop in library.ML; negative length is interpreted
  1504 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1505 
  1506 * Proof terms: type substitutions on proof constants now use canonical
  1507 order of type variables.  INCOMPATIBILITY for tools working with proof
  1508 terms.
  1509 
  1510 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1511 may no longer carry premises.  User-level specifications are
  1512 transformed accordingly by Thm.add_axiom/add_def.
  1513 
  1514 
  1515 *** System ***
  1516 
  1517 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1518 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1519 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1520 
  1521 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1522 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1523 respectively.
  1524 
  1525 * Old lib/scripts/polyml-platform is superseded by the
  1526 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1527 variant, even on a 64 bit machine.  The following example setting
  1528 prefers 64 bit if available:
  1529 
  1530   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1531 
  1532 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1533 Isabelle/Scala layer for advanced prover interaction and integration.
  1534 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1535 component.
  1536 
  1537 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1538 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1539 similar to the default assignment of the document preparation system
  1540 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1541 provides some operations for direct access to the font without asking
  1542 the user for manual installation.
  1543 
  1544 
  1545 
  1546 New in Isabelle2009-1 (December 2009)
  1547 -------------------------------------
  1548 
  1549 *** General ***
  1550 
  1551 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1552 one backslash should be used, even in ML sources.
  1553 
  1554 
  1555 *** Pure ***
  1556 
  1557 * Locale interpretation propagates mixins along the locale hierarchy.
  1558 The currently only available mixins are the equations used to map
  1559 local definitions to terms of the target domain of an interpretation.
  1560 
  1561 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1562 loc" to print all interpretations of locale "loc" in the theory.
  1563 Interpretations in proofs are not shown.
  1564 
  1565 * Thoroughly revised locales tutorial.  New section on conditional
  1566 interpretation.
  1567 
  1568 * On instantiation of classes, remaining undefined class parameters
  1569 are formally declared.  INCOMPATIBILITY.
  1570 
  1571 
  1572 *** Document preparation ***
  1573 
  1574 * New generalized style concept for printing terms: @{foo (style) ...}
  1575 instead of @{foo_style style ...}  (old form is still retained for
  1576 backward compatibility).  Styles can be also applied for
  1577 antiquotations prop, term_type and typeof.
  1578 
  1579 
  1580 *** HOL ***
  1581 
  1582 * New proof method "smt" for a combination of first-order logic with
  1583 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1584 fixed-size bitvectors; there is also basic support for higher-order
  1585 features (esp. lambda abstractions).  It is an incomplete decision
  1586 procedure based on external SMT solvers using the oracle mechanism;
  1587 for the SMT solver Z3, this method is proof-producing.  Certificates
  1588 are provided to avoid calling the external solvers solely for
  1589 re-checking proofs.  Due to a remote SMT service there is no need for
  1590 installing SMT solvers locally.  See src/HOL/SMT.
  1591 
  1592 * New commands to load and prove verification conditions generated by
  1593 the Boogie program verifier or derived systems (e.g. the Verifying C
  1594 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1595 
  1596 * New counterexample generator tool 'nitpick' based on the Kodkod
  1597 relational model finder.  See src/HOL/Tools/Nitpick and
  1598 src/HOL/Nitpick_Examples.
  1599 
  1600 * New commands 'code_pred' and 'values' to invoke the predicate
  1601 compiler and to enumerate values of inductive predicates.
  1602 
  1603 * A tabled implementation of the reflexive transitive closure.
  1604 
  1605 * New implementation of quickcheck uses generic code generator;
  1606 default generators are provided for all suitable HOL types, records
  1607 and datatypes.  Old quickcheck can be re-activated importing theory
  1608 Library/SML_Quickcheck.
  1609 
  1610 * New testing tool Mirabelle for automated proof tools.  Applies
  1611 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1612 every proof step in a theory.  To be used in batch mode via the
  1613 "mirabelle" utility.
  1614 
  1615 * New proof method "sos" (sum of squares) for nonlinear real
  1616 arithmetic (originally due to John Harison). It requires theory
  1617 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1618 works well in practice on quantifier-free real arithmetic with +, -,
  1619 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1620 inequalities between polynomials.  It makes use of external
  1621 semidefinite programming solvers.  Method "sos" generates a
  1622 certificate that can be pasted into the proof thus avoiding the need
  1623 to call an external tool every time the proof is checked.  See
  1624 src/HOL/Library/Sum_Of_Squares.
  1625 
  1626 * New method "linarith" invokes existing linear arithmetic decision
  1627 procedure only.
  1628 
  1629 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1630 
  1631 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1632 Causes full type information to be output to the ATPs.  This slows
  1633 ATPs down considerably but eliminates a source of unsound "proofs"
  1634 that fail later.
  1635 
  1636 * New method "metisFT": A version of metis that uses full type
  1637 information in order to avoid failures of proof reconstruction.
  1638 
  1639 * New evaluator "approximate" approximates an real valued term using
  1640 the same method as the approximation method.
  1641 
  1642 * Method "approximate" now supports arithmetic expressions as
  1643 boundaries of intervals and implements interval splitting and Taylor
  1644 series expansion.
  1645 
  1646 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1647 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1648 
  1649 * New theory SupInf of the supremum and infimum operators for sets of
  1650 reals.
  1651 
  1652 * New theory Probability, which contains a development of measure
  1653 theory, eventually leading to Lebesgue integration and probability.
  1654 
  1655 * Extended Multivariate Analysis to include derivation and Brouwer's
  1656 fixpoint theorem.
  1657 
  1658 * Reorganization of number theory, INCOMPATIBILITY:
  1659   - new number theory development for nat and int, in theories Divides
  1660     and GCD as well as in new session Number_Theory
  1661   - some constants and facts now suffixed with _nat and _int
  1662     accordingly
  1663   - former session NumberTheory now named Old_Number_Theory, including
  1664     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1665   - moved theory Pocklington from src/HOL/Library to
  1666     src/HOL/Old_Number_Theory
  1667 
  1668 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1669 lcm of finite and infinite sets. It is shown that they form a complete
  1670 lattice.
  1671 
  1672 * Class semiring_div requires superclass no_zero_divisors and proof of
  1673 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1674 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1675 generalized to class semiring_div, subsuming former theorems
  1676 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1677 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1678 INCOMPATIBILITY.
  1679 
  1680 * Refinements to lattice classes and sets:
  1681   - less default intro/elim rules in locale variant, more default
  1682     intro/elim rules in class variant: more uniformity
  1683   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1684     le_inf_iff
  1685   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1686     sup_aci)
  1687   - renamed ACI to inf_sup_aci
  1688   - new class "boolean_algebra"
  1689   - class "complete_lattice" moved to separate theory
  1690     "Complete_Lattice"; corresponding constants (and abbreviations)
  1691     renamed and with authentic syntax:
  1692     Set.Inf ~>    Complete_Lattice.Inf
  1693     Set.Sup ~>    Complete_Lattice.Sup
  1694     Set.INFI ~>   Complete_Lattice.INFI
  1695     Set.SUPR ~>   Complete_Lattice.SUPR
  1696     Set.Inter ~>  Complete_Lattice.Inter
  1697     Set.Union ~>  Complete_Lattice.Union
  1698     Set.INTER ~>  Complete_Lattice.INTER
  1699     Set.UNION ~>  Complete_Lattice.UNION
  1700   - authentic syntax for
  1701     Set.Pow
  1702     Set.image
  1703   - mere abbreviations:
  1704     Set.empty               (for bot)
  1705     Set.UNIV                (for top)
  1706     Set.inter               (for inf, formerly Set.Int)
  1707     Set.union               (for sup, formerly Set.Un)
  1708     Complete_Lattice.Inter  (for Inf)
  1709     Complete_Lattice.Union  (for Sup)
  1710     Complete_Lattice.INTER  (for INFI)
  1711     Complete_Lattice.UNION  (for SUPR)
  1712   - object-logic definitions as far as appropriate
  1713 
  1714 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1715 Un_subset_iff are explicitly deleted as default simp rules; then also
  1716 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1717 deleted to achieve the desired effect.
  1718 
  1719 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1720 rules by default any longer; the same applies to min_max.inf_absorb1
  1721 etc.  INCOMPATIBILITY.
  1722 
  1723 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1724 pred_set_conv by default.  INCOMPATIBILITY.
  1725 
  1726 * Power operations on relations and functions are now one dedicated
  1727 constant "compow" with infix syntax "^^".  Power operation on
  1728 multiplicative monoids retains syntax "^" and is now defined generic
  1729 in class power.  INCOMPATIBILITY.
  1730 
  1731 * Relation composition "R O S" now has a more standard argument order:
  1732 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1733 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1734 break, since the O_assoc rule was not rewritten like this.  Fix using
  1735 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1736 
  1737 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1738 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1739 INCOMPATIBILITY.
  1740 
  1741 * Most rules produced by inductive and datatype package have mandatory
  1742 prefixes.  INCOMPATIBILITY.
  1743 
  1744 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1745 the attribute of the same name.  Each of the theorems in the list
  1746 DERIV_intros assumes composition with an additional function and
  1747 matches a variable to the derivative, which has to be solved by the
  1748 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1749 of most elementary terms.  Former Maclauren.DERIV_tac and
  1750 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1751 INCOMPATIBILITY.
  1752 
  1753 * Code generator attributes follow the usual underscore convention:
  1754     code_unfold     replaces    code unfold
  1755     code_post       replaces    code post
  1756     etc.
  1757   INCOMPATIBILITY.
  1758 
  1759 * Renamed methods:
  1760     sizechange -> size_change
  1761     induct_scheme -> induction_schema
  1762   INCOMPATIBILITY.
  1763 
  1764 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1765 INCOMPATIBILITY, use "undefined" directly.
  1766 
  1767 * Renamed theorems:
  1768     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1769     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1770     Suc_plus1 -> Suc_eq_plus1
  1771     *anti_sym -> *antisym*
  1772     vector_less_eq_def -> vector_le_def
  1773   INCOMPATIBILITY.
  1774 
  1775 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1776 INCOMPATIBILITY.
  1777 
  1778 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1779 INCOMPATIBILITY.
  1780 
  1781 
  1782 *** HOLCF ***
  1783 
  1784 * Theory Representable defines a class "rep" of domains that are
  1785 representable (via an ep-pair) in the universal domain type "udom".
  1786 Instances are provided for all type constructors defined in HOLCF.
  1787 
  1788 * The 'new_domain' command is a purely definitional version of the
  1789 domain package, for representable domains.  Syntax is identical to the
  1790 old domain package.  The 'new_domain' package also supports indirect
  1791 recursion using previously-defined type constructors.  See
  1792 src/HOLCF/ex/New_Domain.thy for examples.
  1793 
  1794 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1795 on the left-hand side of an equation, and then performs
  1796 simplification.  Rewriting is done using rules declared with the
  1797 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1798 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1799 
  1800 * The pattern-match compiler in 'fixrec' can now handle constructors
  1801 with HOL function types.  Pattern-match combinators for the Pair
  1802 constructor are pre-configured.
  1803 
  1804 * The 'fixrec' package now produces better fixed-point induction rules
  1805 for mutually-recursive definitions:  Induction rules have conclusions
  1806 of the form "P foo bar" instead of "P <foo, bar>".
  1807 
  1808 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1809 been renamed to "below".  The name "below" now replaces "less" in many
  1810 theorem names.  (Legacy theorem names using "less" are still supported
  1811 as well.)
  1812 
  1813 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1814 patterns can be used to generate strictness rules, or to make
  1815 functions more strict (much like the bang-patterns supported by the
  1816 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1817 examples.
  1818 
  1819 
  1820 *** ML ***
  1821 
  1822 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1823 errors and run-time exceptions, including detailed source positions.
  1824 
  1825 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1826 identified entries, with some additional information such as source
  1827 position, logical grouping etc.
  1828 
  1829 * Theory and context data is now introduced by the simplified and
  1830 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1831 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1832 copy operation) is still available for some time.
  1833 
  1834 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1835 provides a high-level programming interface to synchronized state
  1836 variables with atomic update.  This works via pure function
  1837 application within a critical section -- its runtime should be as
  1838 short as possible; beware of deadlocks if critical code is nested,
  1839 either directly or indirectly via other synchronized variables!
  1840 
  1841 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1842 wraps raw ML references, explicitly indicating their non-thread-safe
  1843 behaviour.  The Isar toplevel keeps this structure open, to
  1844 accommodate Proof General as well as quick and dirty interactive
  1845 experiments with references.
  1846 
  1847 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1848 parallel tactical reasoning.
  1849 
  1850 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1851 are similar to SUBPROOF, but are slightly more flexible: only the
  1852 specified parts of the subgoal are imported into the context, and the
  1853 body tactic may introduce new subgoals and schematic variables.
  1854 
  1855 * Old tactical METAHYPS, which does not observe the proof context, has
  1856 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1857 or Subgoal.FOCUS etc.
  1858 
  1859 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1860 functors have their own ML name space there is no point to mark them
  1861 separately.)  Minor INCOMPATIBILITY.
  1862 
  1863 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1864 
  1865 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1866 INCOMPATIBILITY.
  1867 
  1868 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1869 mode, which avoids critical setmp.
  1870 
  1871 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1872 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1873 Attrib/Method.setup introduced in Isabelle2009.
  1874 
  1875 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1876 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1877 last resort.  INCOMPATIBILITY.
  1878 
  1879 * Display.pretty_thm now requires a proper context (cf. former
  1880 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1881 or even Display.pretty_thm_without_context as last resort.
  1882 INCOMPATIBILITY.
  1883 
  1884 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1885 Syntax.pretty_typ/term directly, preferably with proper context
  1886 instead of global theory.
  1887 
  1888 
  1889 *** System ***
  1890 
  1891 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1892 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1893 usedir option -q.
  1894 
  1895 * Support for additional "Isabelle components" via etc/components, see
  1896 also the system manual.
  1897 
  1898 * The isabelle makeall tool now operates on all components with
  1899 IsaMakefile, not just hardwired "logics".
  1900 
  1901 * Removed "compress" option from isabelle-process and isabelle usedir;
  1902 this is always enabled.
  1903 
  1904 * Discontinued support for Poly/ML 4.x versions.
  1905 
  1906 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1907 on a given logic image.  This requires the lighttpd webserver and is
  1908 currently supported on Linux only.
  1909 
  1910 
  1911 
  1912 New in Isabelle2009 (April 2009)
  1913 --------------------------------
  1914 
  1915 *** General ***
  1916 
  1917 * Simplified main Isabelle executables, with less surprises on
  1918 case-insensitive file-systems (such as Mac OS).
  1919 
  1920   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1921     "isatool."
  1922 
  1923   - The former "isabelle" alias for "isabelle-process" has been
  1924     removed (should rarely occur to regular users).
  1925 
  1926   - The former "isabelle-interface" and its alias "Isabelle" have been
  1927     removed (interfaces are now regular Isabelle tools).
  1928 
  1929 Within scripts and make files, the Isabelle environment variables
  1930 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1931 respectively.  (The latter are still available as legacy feature.)
  1932 
  1933 The old isabelle-interface wrapper could react in confusing ways if
  1934 the interface was uninstalled or changed otherwise.  Individual
  1935 interface tool configuration is now more explicit, see also the
  1936 Isabelle system manual.  In particular, Proof General is now available
  1937 via "isabelle emacs".
  1938 
  1939 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1940 purge installed copies of Isabelle executables and re-run "isabelle
  1941 install -p ...", or use symlinks.
  1942 
  1943 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1944 old ~/isabelle, which was slightly non-standard and apt to cause
  1945 surprises on case-insensitive file-systems (such as Mac OS).
  1946 
  1947 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1948 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1949 care is required when using older releases of Isabelle.  Note that
  1950 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1951 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1952 
  1953 * Proofs of fully specified statements are run in parallel on
  1954 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1955 a regular 4-core machine, if the initial heap space is made reasonably
  1956 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1957 
  1958 * The main reference manuals ("isar-ref", "implementation", and
  1959 "system") have been updated and extended.  Formally checked references
  1960 as hyperlinks are now available uniformly.
  1961 
  1962 
  1963 *** Pure ***
  1964 
  1965 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1966 respects.  The most important changes are listed below.  See the
  1967 Tutorial on Locales ("locales" manual) for details.
  1968 
  1969 - In locale expressions, instantiation replaces renaming.  Parameters
  1970 must be declared in a for clause.  To aid compatibility with previous
  1971 parameter inheritance, in locale declarations, parameters that are not
  1972 'touched' (instantiation position "_" or omitted) are implicitly added
  1973 with their syntax at the beginning of the for clause.
  1974 
  1975 - Syntax from abbreviations and definitions in locales is available in
  1976 locale expressions and context elements.  The latter is particularly
  1977 useful in locale declarations.
  1978 
  1979 - More flexible mechanisms to qualify names generated by locale
  1980 expressions.  Qualifiers (prefixes) may be specified in locale
  1981 expressions, and can be marked as mandatory (syntax: "name!:") or
  1982 optional (syntax "name?:").  The default depends for plain "name:"
  1983 depends on the situation where a locale expression is used: in
  1984 commands 'locale' and 'sublocale' prefixes are optional, in
  1985 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1986 implicit qualifiers derived from the parameter names of a locale are
  1987 no longer generated.
  1988 
  1989 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1990 instantiation clause in "interpretation" and "interpret" (square
  1991 brackets) is no longer available.  Use locale expressions.
  1992 
  1993 - When converting proof scripts, mandatory qualifiers in
  1994 'interpretation' and 'interpret' should be retained by default, even
  1995 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1996 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1997 in locale expressions range over a single locale instance only.
  1998 
  1999 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2000 In existing theorem specifications replace the includes element by the
  2001 respective context elements of the included locale, omitting those
  2002 that are already present in the theorem specification.  Multiple
  2003 assume elements of a locale should be replaced by a single one
  2004 involving the locale predicate.  In the proof body, declarations (most
  2005 notably theorems) may be regained by interpreting the respective
  2006 locales in the proof context as required (command "interpret").
  2007 
  2008 If using "includes" in replacement of a target solely because the
  2009 parameter types in the theorem are not as general as in the target,
  2010 consider declaring a new locale with additional type constraints on
  2011 the parameters (context element "constrains").
  2012 
  2013 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2014 
  2015 - Locale interpretation commands no longer attempt to simplify goal.
  2016 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2017 methods intro_locales and unfold_locales to clarify.
  2018 
  2019 - Locale interpretation commands no longer accept interpretation
  2020 attributes.  INCOMPATIBILITY.
  2021 
  2022 * Class declaration: so-called "base sort" must not be given in import
  2023 list any longer, but is inferred from the specification.  Particularly
  2024 in HOL, write
  2025 
  2026     class foo = ...
  2027 
  2028 instead of
  2029 
  2030     class foo = type + ...
  2031 
  2032 * Class target: global versions of theorems stemming do not carry a
  2033 parameter prefix any longer.  INCOMPATIBILITY.
  2034 
  2035 * Class 'instance' command no longer accepts attached definitions.
  2036 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2037 
  2038 * Recovered hiding of consts, which was accidentally broken in
  2039 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2040 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2041 
  2042 * Slightly more coherent Pure syntax, with updated documentation in
  2043 isar-ref manual.  Removed locales meta_term_syntax and
  2044 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2045 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2046 directly in regular applications.
  2047 
  2048 * There is a new syntactic category "float_const" for signed decimal
  2049 fractions (e.g. 123.45 or -123.45).
  2050 
  2051 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2052 interface with 'setup' command instead.
  2053 
  2054 * Command 'local_setup' is similar to 'setup', but operates on a local
  2055 theory context.
  2056 
  2057 * The 'axiomatization' command now only works within a global theory
  2058 context.  INCOMPATIBILITY.
  2059 
  2060 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2061 hypotheses.  Sorts required in the course of reasoning need to be
  2062 covered by the constraints in the initial statement, completed by the
  2063 type instance information of the background theory.  Non-trivial sort
  2064 hypotheses, which rarely occur in practice, may be specified via
  2065 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2066 
  2067   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2068 
  2069 The result contains an implicit sort hypotheses as before --
  2070 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2071 normalization.
  2072 
  2073 * Generalized Isar history, with support for linear undo, direct state
  2074 addressing etc.
  2075 
  2076 * Changed defaults for unify configuration options:
  2077 
  2078   unify_trace_bound = 50 (formerly 25)
  2079   unify_search_bound = 60 (formerly 30)
  2080 
  2081 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2082 
  2083   a) On theory merge, the last set of code equations for a particular
  2084      constant is taken (in accordance with the policy applied by other
  2085      parts of the code generator framework).
  2086 
  2087   b) Code equations stemming from explicit declarations (e.g. code
  2088      attribute) gain priority over default code equations stemming
  2089      from definition, primrec, fun etc.
  2090 
  2091 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2092 
  2093 * Unified theorem tables for both code generators.  Thus [code
  2094 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2095 
  2096 * Command 'find_consts' searches for constants based on type and name
  2097 patterns, e.g.
  2098 
  2099     find_consts "_ => bool"
  2100 
  2101 By default, matching is against subtypes, but it may be restricted to
  2102 the whole type.  Searching by name is possible.  Multiple queries are
  2103 conjunctive and queries may be negated by prefixing them with a
  2104 hyphen:
  2105 
  2106     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2107 
  2108 * New 'find_theorems' criterion "solves" matches theorems that
  2109 directly solve the current goal (modulo higher-order unification).
  2110 
  2111 * Auto solve feature for main theorem statements: whenever a new goal
  2112 is stated, "find_theorems solves" is called; any theorems that could
  2113 solve the lemma directly are listed as part of the goal state.
  2114 Cf. associated options in Proof General Isabelle settings menu,
  2115 enabled by default, with reasonable timeout for pathological cases of
  2116 higher-order unification.
  2117 
  2118 
  2119 *** Document preparation ***
  2120 
  2121 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2122 demanding keyword 'by' and supporting the full method expression
  2123 syntax just like the Isar command 'by'.
  2124 
  2125 
  2126 *** HOL ***
  2127 
  2128 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2129 points Main and Complex_Main remain as before.
  2130 
  2131 * Logic image HOL-Plain provides a minimal HOL with the most important
  2132 tools available (inductive, datatype, primrec, ...).  This facilitates
  2133 experimentation and tool development.  Note that user applications
  2134 (and library theories) should never refer to anything below theory
  2135 Main, as before.
  2136 
  2137 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2138 experimentation due to shorter build times.
  2139 
  2140 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2141 were previously part of former HOL-Complex.  Entry point Hyperreal
  2142 remains valid, but theories formerly using Complex_Main should now use
  2143 new entry point Hypercomplex.
  2144 
  2145 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2146 Posix processes.  Avoids potentially expensive forking of the ML
  2147 process.  New thread-based implementation also works on non-Unix
  2148 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2149 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2150 commands are covered in the isar-ref manual.
  2151 
  2152 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2153 sledgehammer without local ATP installation (Vampire etc.). Other
  2154 provers may be included via suitable ML wrappers, see also
  2155 src/HOL/ATP_Linkup.thy.
  2156 
  2157 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2158 menu.
  2159 
  2160 * The metis method no longer fails because the theorem is too trivial
  2161 (contains the empty clause).
  2162 
  2163 * The metis method now fails in the usual manner, rather than raising
  2164 an exception, if it determines that it cannot prove the theorem.
  2165 
  2166 * Method "coherent" implements a prover for coherent logic (see also
  2167 src/Tools/coherent.ML).
  2168 
  2169 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2170 "undefined" is the right choice to replace "arbitrary", though
  2171 logically there is no difference.  INCOMPATIBILITY.
  2172 
  2173 * Command "value" now integrates different evaluation mechanisms.  The
  2174 result of the first successful evaluation mechanism is printed.  In
  2175 square brackets a particular named evaluation mechanisms may be
  2176 specified (currently, [SML], [code] or [nbe]).  See further
  2177 src/HOL/ex/Eval_Examples.thy.
  2178 
  2179 * Normalization by evaluation now allows non-leftlinear equations.
  2180 Declare with attribute [code nbe].
  2181 
  2182 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2183 as the structured Isar versions "cases" and "induct", cf. the
  2184 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2185 are now presented as a list of individual projections
  2186 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2187 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2188 rare situations a different rule is selected --- notably nested tuple
  2189 elimination instead of former prod.exhaust: use explicit (case_tac t
  2190 rule: prod.exhaust) here.
  2191 
  2192 * Attributes "cases", "induct", "coinduct" support "del" option.
  2193 
  2194 * Removed fact "case_split_thm", which duplicates "case_split".
  2195 
  2196 * The option datatype has been moved to a new theory Option.  Renamed
  2197 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2198 
  2199 * New predicate "strict_mono" classifies strict functions on partial
  2200 orders.  With strict functions on linear orders, reasoning about
  2201 (in)equalities is facilitated by theorems "strict_mono_eq",
  2202 "strict_mono_less_eq" and "strict_mono_less".
  2203 
  2204 * Some set operations are now proper qualified constants with
  2205 authentic syntax.  INCOMPATIBILITY:
  2206 
  2207     op Int ~>   Set.Int
  2208     op Un ~>    Set.Un
  2209     INTER ~>    Set.INTER
  2210     UNION ~>    Set.UNION
  2211     Inter ~>    Set.Inter
  2212     Union ~>    Set.Union
  2213     {} ~>       Set.empty
  2214     UNIV ~>     Set.UNIV
  2215 
  2216 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2217 theory Set.
  2218 
  2219 * Auxiliary class "itself" has disappeared -- classes without any
  2220 parameter are treated as expected by the 'class' command.
  2221 
  2222 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2223 
  2224 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2225 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2226 
  2227 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2228 method "approximation".  It proves formulas on real values by using
  2229 interval arithmetic.  In the formulas are also the transcendental
  2230 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2231 allowed. For examples see
  2232 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2233 
  2234 * Theory "Reflection" now resides in HOL/Library.
  2235 
  2236 * Entry point to Word library now simply named "Word".
  2237 INCOMPATIBILITY.
  2238 
  2239 * Made source layout more coherent with logical distribution
  2240 structure:
  2241 
  2242     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2243     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2244     src/HOL/Library/GCD.thy ~> src/HOL/
  2245     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2246     src/HOL/Library/Parity.thy ~> src/HOL/
  2247     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2248     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2249     src/HOL/Real/Lubs.thy ~> src/HOL/
  2250     src/HOL/Real/PReal.thy ~> src/HOL/
  2251     src/HOL/Real/Rational.thy ~> src/HOL/
  2252     src/HOL/Real/RComplete.thy ~> src/HOL/
  2253     src/HOL/Real/RealDef.thy ~> src/HOL/
  2254     src/HOL/Real/RealPow.thy ~> src/HOL/
  2255     src/HOL/Real/Real.thy ~> src/HOL/
  2256     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2257     src/HOL/Complex/Complex.thy ~> src/HOL/
  2258     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2259     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2260     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2261     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2262     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2263     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2264     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2265     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2266     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2267     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2268     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2269     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2270     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2271     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2272     src/HOL/Real/Float ~> src/HOL/Library/
  2273     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2274     src/HOL/Real/RealVector.thy ~> src/HOL/
  2275 
  2276     src/HOL/arith_data.ML ~> src/HOL/Tools
  2277     src/HOL/hologic.ML ~> src/HOL/Tools
  2278     src/HOL/simpdata.ML ~> src/HOL/Tools
  2279     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2280     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2281     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2282     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2283     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2284     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2285     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2286 
  2287     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2288     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2289     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2290     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2291     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2292     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2293 
  2294 * If methods "eval" and "evaluation" encounter a structured proof
  2295 state with !!/==>, only the conclusion is evaluated to True (if
  2296 possible), avoiding strange error messages.
  2297 
  2298 * Method "sizechange" automates termination proofs using (a
  2299 modification of) the size-change principle.  Requires SAT solver.  See
  2300 src/HOL/ex/Termination.thy for examples.
  2301 
  2302 * Simplifier: simproc for let expressions now unfolds if bound
  2303 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2304 
  2305 * Method "arith": Linear arithmetic now ignores all inequalities when
  2306 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2307 
  2308 * New attribute "arith" for facts that should always be used
  2309 automatically by arithmetic. It is intended to be used locally in
  2310 proofs, e.g.
  2311 
  2312   assumes [arith]: "x > 0"
  2313 
  2314 Global usage is discouraged because of possible performance impact.
  2315 
  2316 * New classes "top" and "bot" with corresponding operations "top" and
  2317 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2318 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2319 
  2320 * Changed definition lemma "less_fun_def" in order to provide an
  2321 instance for preorders on functions; use lemma "less_le" instead.
  2322 INCOMPATIBILITY.
  2323 
  2324 * Theory Orderings: class "wellorder" moved here, with explicit
  2325 induction rule "less_induct" as assumption.  For instantiation of
  2326 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2327 INCOMPATIBILITY.
  2328 
  2329 * Theory Orderings: added class "preorder" as superclass of "order".
  2330 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2331 etc. slightly changed.  Some theorems named order_class.* now named
  2332 preorder_class.*.
  2333 
  2334 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2335 "diag" to "Id_on".
  2336 
  2337 * Theory Finite_Set: added a new fold combinator of type
  2338 
  2339   ('a => 'b => 'b) => 'b => 'a set => 'b
  2340 
  2341 Occasionally this is more convenient than the old fold combinator
  2342 which is now defined in terms of the new one and renamed to
  2343 fold_image.
  2344 
  2345 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2346 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2347 extended with further lemmas!).  At the moment both still exist but
  2348 the former will disappear at some point.
  2349 
  2350 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2351 class recpower.  Type-specific simp rules for various recpower types
  2352 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2353 
  2354 rat_power_0    -> power_0
  2355 rat_power_Suc  -> power_Suc
  2356 realpow_0      -> power_0
  2357 realpow_Suc    -> power_Suc
  2358 complexpow_0   -> power_0
  2359 complexpow_Suc -> power_Suc
  2360 power_poly_0   -> power_0
  2361 power_poly_Suc -> power_Suc
  2362 
  2363 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2364 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2365 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2366 of lemmas from Divides has been generalized from nat to class
  2367 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2368 renames resulting from duplicate elimination:
  2369 
  2370     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2371     zero_dvd_iff ~>         dvd_0_left_iff
  2372     dvd_0 ~>                dvd_0_right
  2373     DIVISION_BY_ZERO_DIV ~> div_by_0
  2374     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2375     mult_div ~>             div_mult_self2_is_id
  2376     mult_mod ~>             mod_mult_self2_is_0
  2377 
  2378 * Theory IntDiv: removed many lemmas that are instances of class-based
  2379 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2380 rename old lemmas as follows:
  2381 
  2382 dvd_diff               -> nat_dvd_diff
  2383 dvd_zminus_iff         -> dvd_minus_iff
  2384 mod_add1_eq            -> mod_add_eq
  2385 mod_mult1_eq           -> mod_mult_right_eq
  2386 mod_mult1_eq'          -> mod_mult_left_eq
  2387 mod_mult_distrib_mod   -> mod_mult_eq
  2388 nat_mod_add_left_eq    -> mod_add_left_eq
  2389 nat_mod_add_right_eq   -> mod_add_right_eq
  2390 nat_mod_div_trivial    -> mod_div_trivial
  2391 nat_mod_mod_trivial    -> mod_mod_trivial
  2392 zdiv_zadd_self1        -> div_add_self1
  2393 zdiv_zadd_self2        -> div_add_self2
  2394 zdiv_zmult_self1       -> div_mult_self2_is_id
  2395 zdiv_zmult_self2       -> div_mult_self1_is_id
  2396 zdvd_triv_left         -> dvd_triv_left
  2397 zdvd_triv_right        -> dvd_triv_right
  2398 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2399 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2400 zmod_zadd_left_eq      -> mod_add_left_eq
  2401 zmod_zadd_right_eq     -> mod_add_right_eq
  2402 zmod_zadd_self1        -> mod_add_self1
  2403 zmod_zadd_self2        -> mod_add_self2
  2404 zmod_zadd1_eq          -> mod_add_eq
  2405 zmod_zdiff1_eq         -> mod_diff_eq
  2406 zmod_zdvd_zmod         -> mod_mod_cancel
  2407 zmod_zmod_cancel       -> mod_mod_cancel
  2408 zmod_zmult_self1       -> mod_mult_self2_is_0
  2409 zmod_zmult_self2       -> mod_mult_self1_is_0
  2410 zmod_1                 -> mod_by_1
  2411 zdiv_1                 -> div_by_1
  2412 zdvd_abs1              -> abs_dvd_iff
  2413 zdvd_abs2              -> dvd_abs_iff
  2414 zdvd_refl              -> dvd_refl
  2415 zdvd_trans             -> dvd_trans
  2416 zdvd_zadd              -> dvd_add
  2417 zdvd_zdiff             -> dvd_diff
  2418 zdvd_zminus_iff        -> dvd_minus_iff
  2419 zdvd_zminus2_iff       -> minus_dvd_iff
  2420 zdvd_zmultD            -> dvd_mult_right
  2421 zdvd_zmultD2           -> dvd_mult_left
  2422 zdvd_zmult_mono        -> mult_dvd_mono
  2423 zdvd_0_right           -> dvd_0_right
  2424 zdvd_0_left            -> dvd_0_left_iff
  2425 zdvd_1_left            -> one_dvd
  2426 zminus_dvd_iff         -> minus_dvd_iff
  2427 
  2428 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2429 
  2430 * The real numbers offer decimal input syntax: 12.34 is translated
  2431 into 1234/10^2. This translation is not reversed upon output.
  2432 
  2433 * Theory Library/Polynomial defines an abstract type 'a poly of
  2434 univariate polynomials with coefficients of type 'a.  In addition to
  2435 the standard ring operations, it also supports div and mod.  Code
  2436 generation is also supported, using list-style constructors.
  2437 
  2438 * Theory Library/Inner_Product defines a class of real_inner for real
  2439 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2440 => real.  Class real_inner is a subclass of real_normed_vector from
  2441 theory RealVector.
  2442 
  2443 * Theory Library/Product_Vector provides instances for the product
  2444 type 'a * 'b of several classes from RealVector and Inner_Product.
  2445 Definitions of addition, subtraction, scalar multiplication, norms,
  2446 and inner products are included.
  2447 
  2448 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2449 addition to the field operations, numerals and case syntax are also
  2450 supported.
  2451 
  2452 * Theory Library/Diagonalize provides constructive version of Cantor's
  2453 first diagonalization argument.
  2454 
  2455 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2456 zlcm (for int); carried together from various gcd/lcm developements in
  2457 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2458 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2459 may recover tupled syntax as follows:
  2460 
  2461     hide (open) const gcd
  2462     abbreviation gcd where
  2463       "gcd == (%(a, b). GCD.gcd a b)"
  2464     notation (output)
  2465       GCD.gcd ("gcd '(_, _')")
  2466 
  2467 The same works for lcm, zgcd, zlcm.
  2468 
  2469 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2470 instantiations for algebraic structures.  Removed some duplicate
  2471 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2472 
  2473 * ML antiquotation @{code} takes a constant as argument and generates
  2474 corresponding code in background and inserts name of the corresponding
  2475 resulting ML value/function/datatype constructor binding in place.
  2476 All occurrences of @{code} with a single ML block are generated
  2477 simultaneously.  Provides a generic and safe interface for
  2478 instrumentalizing code generation.  See
  2479 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2480 In future you ought to refrain from ad-hoc compiling generated SML
  2481 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2482 cannot refer to constants for which user-defined serializations are
  2483 set.  Refer to the corresponding ML counterpart directly in that
  2484 cases.
  2485 
  2486 * Command 'rep_datatype': instead of theorem names the command now
  2487 takes a list of terms denoting the constructors of the type to be
  2488 represented as datatype.  The characteristic theorems have to be
  2489 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2490 have disappeared in favour of existing ones:
  2491 
  2492     unit_induct                 ~> unit.induct
  2493     prod_induct                 ~> prod.induct
  2494     sum_induct                  ~> sum.induct
  2495     Suc_Suc_eq                  ~> nat.inject
  2496     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2497 
  2498 
  2499 *** HOL-Algebra ***
  2500 
  2501 * New locales for orders and lattices where the equivalence relation
  2502 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2503 locales use a record structure with field eq for the equivalence.
  2504 
  2505 * New theory of factorial domains.
  2506 
  2507 * Units_l_inv and Units_r_inv are now simp rules by default.
  2508 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2509 and/or r_inv will now also require deletion of these lemmas.
  2510 
  2511 * Renamed the following theorems, INCOMPATIBILITY:
  2512 
  2513 UpperD ~> Upper_memD
  2514 LowerD ~> Lower_memD
  2515 least_carrier ~> least_closed
  2516 greatest_carrier ~> greatest_closed
  2517 greatest_Lower_above ~> greatest_Lower_below
  2518 one_zero ~> carrier_one_zero
  2519 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2520 
  2521 
  2522 *** HOL-Nominal ***
  2523 
  2524 * Nominal datatypes can now contain type-variables.
  2525 
  2526 * Commands 'nominal_inductive' and 'equivariance' work with local
  2527 theory targets.
  2528 
  2529 * Nominal primrec can now works with local theory targets and its
  2530 specification syntax now conforms to the general format as seen in
  2531 'inductive' etc.
  2532 
  2533 * Method "perm_simp" honours the standard simplifier attributes
  2534 (no_asm), (no_asm_use) etc.
  2535 
  2536 * The new predicate #* is defined like freshness, except that on the
  2537 left hand side can be a set or list of atoms.
  2538 
  2539 * Experimental command 'nominal_inductive2' derives strong induction
  2540 principles for inductive definitions.  In contrast to
  2541 'nominal_inductive', which can only deal with a fixed number of
  2542 binders, it can deal with arbitrary expressions standing for sets of
  2543 atoms to be avoided.  The only inductive definition we have at the
  2544 moment that needs this generalisation is the typing rule for Lets in
  2545 the algorithm W:
  2546 
  2547  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2548  -----------------------------------------------------------------
  2549          Gamma |- Let x be t1 in t2 : T2
  2550 
  2551 In this rule one wants to avoid all the binders that are introduced by
  2552 "close Gamma T1".  We are looking for other examples where this
  2553 feature might be useful.  Please let us know.
  2554 
  2555 
  2556 *** HOLCF ***
  2557 
  2558 * Reimplemented the simplification procedure for proving continuity
  2559 subgoals.  The new simproc is extensible; users can declare additional
  2560 continuity introduction rules with the attribute [cont2cont].
  2561 
  2562 * The continuity simproc now uses a different introduction rule for
  2563 solving continuity subgoals on terms with lambda abstractions.  In
  2564 some rare cases the new simproc may fail to solve subgoals that the
  2565 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2566 Potential INCOMPATIBILITY.
  2567 
  2568 * Command 'fixrec': specification syntax now conforms to the general
  2569 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2570 examples.  INCOMPATIBILITY.
  2571 
  2572 
  2573 *** ZF ***
  2574 
  2575 * Proof of Zorn's Lemma for partial orders.
  2576 
  2577 
  2578 *** ML ***
  2579 
  2580 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2581 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2582 depends on multithreading, so timouts will not work before Poly/ML
  2583 5.2.1!
  2584 
  2585 * High-level support for concurrent ML programming, see
  2586 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2587 particularly convenient to organize independent functional
  2588 computations.  The concept of "synchronized variables" provides a
  2589 higher-order interface for components with shared state, avoiding the
  2590 delicate details of mutexes and condition variables.  (Requires
  2591 Poly/ML 5.2.1 or later.)
  2592 
  2593 * ML bindings produced via Isar commands are stored within the Isar
  2594 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2595 become thread-safe and work with undo as expected (concerning
  2596 top-level bindings, not side-effects on global references).
  2597 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2598 compiler at runtime; really global bindings need to be given outside a
  2599 theory.  (Requires Poly/ML 5.2 or later.)
  2600 
  2601 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2602 context.  Top-level ML bindings are stored within the proof context in
  2603 a purely sequential fashion, disregarding the nested proof structure.
  2604 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2605 proof.  (Requires Poly/ML 5.2 or later.)
  2606 
  2607 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2608 and Method.setup, as well as Isar commands 'attribute_setup' and
  2609 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2610 existing code accordingly, or use plain 'setup' together with old
  2611 Method.add_method.
  2612 
  2613 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2614 to 'a -> thm, while results are always tagged with an authentic oracle
  2615 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2616 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2617 accordingly.  Note that extra performance may be gained by producing
  2618 the cterm carefully, avoiding slow Thm.cterm_of.
  2619 
  2620 * Simplified interface for defining document antiquotations via
  2621 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2622 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2623 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2624 examples.
  2625 
  2626 * More systematic treatment of long names, abstract name bindings, and
  2627 name space operations.  Basic operations on qualified names have been
  2628 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2629 Long_Name.append.  Old type bstring has been mostly replaced by
  2630 abstract type binding (see structure Binding), which supports precise
  2631 qualification by packages and local theory targets, as well as proper
  2632 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2633 bstring values into Binding.name, or better pass through abstract
  2634 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2635 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2636 
  2637 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2638 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2639 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2640 
  2641 * Disposed old type and term read functions (Sign.read_def_typ,
  2642 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2643 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2644 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2645 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2646 resort for legacy applications.
  2647 
  2648 * Disposed old declarations, tactics, tactic combinators that refer to
  2649 the simpset or claset of an implicit theory (such as Addsimps,
  2650 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2651 embedded ML text, or local_simpset_of with a proper context passed as
  2652 explicit runtime argument.
  2653 
  2654 * Rules and tactics that read instantiations (read_instantiate,
  2655 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2656 context, which is required for parsing and type-checking.  Moreover,
  2657 the variables are specified as plain indexnames, not string encodings
  2658 thereof.  INCOMPATIBILITY.
  2659 
  2660 * Generic Toplevel.add_hook interface allows to analyze the result of
  2661 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2662 for theorem dependency output of transactions resulting in a new
  2663 theory state.
  2664 
  2665 * ML antiquotations: block-structured compilation context indicated by
  2666 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2667 
  2668   @{binding name}                         - basic name binding
  2669   @{let ?pat = term}                      - term abbreviation (HO matching)
  2670   @{note name = fact}                     - fact abbreviation
  2671   @{thm fact}                             - singleton fact (with attributes)
  2672   @{thms fact}                            - general fact (with attributes)
  2673   @{lemma prop by method}                 - singleton goal
  2674   @{lemma prop by meth1 meth2}            - singleton goal
  2675   @{lemma prop1 ... propN by method}      - general goal
  2676   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2677   @{lemma (open) ...}                     - open derivation
  2678 
  2679 
  2680 *** System ***
  2681 
  2682 * The Isabelle "emacs" tool provides a specific interface to invoke
  2683 Proof General / Emacs, with more explicit failure if that is not
  2684 installed (the old isabelle-interface script silently falls back on
  2685 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2686 installation location of the Proof General distribution.
  2687 
  2688 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2689 the Isabelle process into a JVM/Scala application.  See
  2690 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2691 process wrapper has been discontinued.)
  2692 
  2693 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2694 
  2695 * Various status messages (with exact source position information) are
  2696 emitted, if proper markup print mode is enabled.  This allows
  2697 user-interface components to provide detailed feedback on internal
  2698 prover operations.
  2699 
  2700 
  2701 
  2702 New in Isabelle2008 (June 2008)
  2703 -------------------------------
  2704 
  2705 *** General ***
  2706 
  2707 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2708 and updated, with formally checked references as hyperlinks.
  2709 
  2710 * Theory loader: use_thy (and similar operations) no longer set the
  2711 implicit ML context, which was occasionally hard to predict and in
  2712 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2713 provides a proper context already.
  2714 
  2715 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2716 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2717 'use' within a theory file will do the job.
  2718 
  2719 * Name space merge now observes canonical order, i.e. the second space
  2720 is inserted into the first one, while existing entries in the first
  2721 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2722 swap theory imports.
  2723 
  2724 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2725 INCOMPATIBILITY in identifier syntax etc.
  2726 
  2727 * Outer syntax: string tokens no longer admit escaped white space,
  2728 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2729 white space without escapes.
  2730 
  2731 * Outer syntax: string tokens may contain arbitrary character codes
  2732 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2733 "foo_bar".
  2734 
  2735 
  2736 *** Pure ***
  2737 
  2738 * Context-dependent token translations.  Default setup reverts locally
  2739 fixed variables, and adds hilite markup for undeclared frees.
  2740 
  2741 * Unused theorems can be found using the new command 'unused_thms'.
  2742 There are three ways of invoking it:
  2743 
  2744 (1) unused_thms
  2745      Only finds unused theorems in the current theory.
  2746 
  2747 (2) unused_thms thy_1 ... thy_n -
  2748      Finds unused theorems in the current theory and all of its ancestors,
  2749      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2750 
  2751 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2752      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2753      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2754      their ancestors.
  2755 
  2756 In order to increase the readability of the list produced by
  2757 unused_thms, theorems that have been created by a particular instance
  2758 of a theory command such as 'inductive' or 'function' are considered
  2759 to belong to the same "group", meaning that if at least one theorem in
  2760 this group is used, the other theorems in the same group are no longer
  2761 reported as unused.  Moreover, if all theorems in the group are
  2762 unused, only one theorem in the group is displayed.
  2763 
  2764 Note that proof objects have to be switched on in order for
  2765 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2766 usually the case when using Proof General with the default settings).
  2767 
  2768 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2769 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2770 duplicate fact bindings, or even accidental fact duplications.  Note
  2771 that tools may maintain dynamically scoped facts systematically, using
  2772 PureThy.add_thms_dynamic.
  2773 
  2774 * Command 'hide' now allows to hide from "fact" name space as well.
  2775 
  2776 * Eliminated destructive theorem database, simpset, claset, and
  2777 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2778 update of theories within ML code.
  2779 
  2780 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2781 INCOMPATIBILITY, object-logics depending on former Pure require
  2782 additional setup PureThy.old_appl_syntax_setup; object-logics
  2783 depending on former CPure need to refer to Pure.
  2784 
  2785 * Commands 'use' and 'ML' are now purely functional, operating on
  2786 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2787 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2788 INCOMPATIBILITY.
  2789 
  2790 * Command 'setup': discontinued implicit version with ML reference.
  2791 
  2792 * Instantiation target allows for simultaneous specification of class
  2793 instance operations together with an instantiation proof.
  2794 Type-checking phase allows to refer to class operations uniformly.
  2795 See src/HOL/Complex/Complex.thy for an Isar example and
  2796 src/HOL/Library/Eval.thy for an ML example.
  2797 
  2798 * Indexing of literal facts: be more serious about including only
  2799 facts from the visible specification/proof context, but not the
  2800 background context (locale etc.).  Affects `prop` notation and method
  2801 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2802 situations.
  2803 
  2804 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2805 "(open)" option, which used to expose internal bound variables to the
  2806 proof text.
  2807 
  2808 * Isar statements: removed obsolete case "rule_context".
  2809 INCOMPATIBILITY, better use explicit fixes/assumes.
  2810 
  2811 * Locale proofs: default proof step now includes 'unfold_locales';
  2812 hence 'proof' without argument may be used to unfold locale
  2813 predicates.
  2814 
  2815 
  2816 *** Document preparation ***
  2817 
  2818 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2819 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2820 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2821 spot); renamed link color from "darkblue" to "linkcolor" (default
  2822 value unchanged, can be redefined via \definecolor); no longer sets
  2823 "a4paper" option (unnecessary or even intrusive).
  2824 
  2825 * Antiquotation @{lemma A method} proves proposition A by the given
  2826 method (either a method name or a method name plus (optional) method
  2827 arguments in parentheses) and prints A just like @{prop A}.
  2828 
  2829 
  2830 *** HOL ***
  2831 
  2832 * New primrec package.  Specification syntax conforms in style to
  2833 definition/function/....  No separate induction rule is provided.  The
  2834 "primrec" command distinguishes old-style and new-style specifications
  2835 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2836 When adjusting theories, beware: constants stemming from new-style
  2837 primrec specifications have authentic syntax.
  2838 
  2839 * Metis prover is now an order of magnitude faster, and also works
  2840 with multithreading.
  2841 
  2842 * Metis: the maximum number of clauses that can be produced from a
  2843 theorem is now given by the attribute max_clauses.  Theorems that
  2844 exceed this number are ignored, with a warning printed.
  2845 
  2846 * Sledgehammer no longer produces structured proofs by default. To
  2847 enable, declare [[sledgehammer_full = true]].  Attributes
  2848 reconstruction_modulus, reconstruction_sorts renamed
  2849 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2850 
  2851 * Method "induct_scheme" derives user-specified induction rules
  2852 from well-founded induction and completeness of patterns. This factors
  2853 out some operations that are done internally by the function package
  2854 and makes them available separately.  See
  2855 src/HOL/ex/Induction_Scheme.thy for examples.
  2856 
  2857 * More flexible generation of measure functions for termination
  2858 proofs: Measure functions can be declared by proving a rule of the
  2859 form "is_measure f" and giving it the [measure_function] attribute.
  2860 The "is_measure" predicate is logically meaningless (always true), and
  2861 just guides the heuristic.  To find suitable measure functions, the
  2862 termination prover sets up the goal "is_measure ?f" of the appropriate
  2863 type and generates all solutions by prolog-style backwards proof using
  2864 the declared rules.
  2865 
  2866 This setup also deals with rules like 
  2867 
  2868   "is_measure f ==> is_measure (list_size f)"
  2869 
  2870 which accommodates nested datatypes that recurse through lists.
  2871 Similar rules are predeclared for products and option types.
  2872 
  2873 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2874 
  2875   INCOMPATIBILITIES:
  2876 
  2877   - Definitions of overloaded constants on sets have to be replaced by
  2878     definitions on => and bool.
  2879 
  2880   - Some definitions of overloaded operators on sets can now be proved
  2881     using the definitions of the operators on => and bool.  Therefore,
  2882     the following theorems have been renamed:
  2883 
  2884       subset_def   -> subset_eq
  2885       psubset_def  -> psubset_eq
  2886       set_diff_def -> set_diff_eq
  2887       Compl_def    -> Compl_eq
  2888       Sup_set_def  -> Sup_set_eq
  2889       Inf_set_def  -> Inf_set_eq
  2890       sup_set_def  -> sup_set_eq
  2891       inf_set_def  -> inf_set_eq
  2892 
  2893   - Due to the incompleteness of the HO unification algorithm, some
  2894     rules such as subst may require manual instantiation, if some of
  2895     the unknowns in the rule is a set.
  2896 
  2897   - Higher order unification and forward proofs:
  2898     The proof pattern
  2899 
  2900       have "P (S::'a set)" <...>
  2901       then have "EX S. P S" ..
  2902 
  2903     no longer works (due to the incompleteness of the HO unification
  2904     algorithm) and must be replaced by the pattern
  2905 
  2906       have "EX S. P S"
  2907       proof
  2908         show "P S" <...>
  2909       qed
  2910 
  2911   - Calculational reasoning with subst (or similar rules):
  2912     The proof pattern
  2913 
  2914       have "P (S::'a set)" <...>
  2915       also have "S = T" <...>
  2916       finally have "P T" .
  2917 
  2918     no longer works (for similar reasons as the previous example) and
  2919     must be replaced by something like
  2920 
  2921       have "P (S::'a set)" <...>
  2922       moreover have "S = T" <...>
  2923       ultimately have "P T" by simp
  2924 
  2925   - Tactics or packages written in ML code:
  2926     Code performing pattern matching on types via
  2927 
  2928       Type ("set", [T]) => ...
  2929 
  2930     must be rewritten. Moreover, functions like strip_type or
  2931     binder_types no longer return the right value when applied to a
  2932     type of the form
  2933 
  2934       T1 => ... => Tn => U => bool
  2935 
  2936     rather than
  2937 
  2938       T1 => ... => Tn => U set
  2939 
  2940 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2941 Wellfounded_Relations to theory Wellfounded.
  2942 
  2943 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2944 
  2945 * Class finite no longer treats UNIV as class parameter.  Use class
  2946 enum from theory Library/Enum instead to achieve a similar effect.
  2947 INCOMPATIBILITY.
  2948 
  2949 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2950 and "Cons".  INCOMPATIBILITY.
  2951 
  2952 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2953 Potential INCOMPATIBILITY.
  2954 
  2955 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2956 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2957 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2958 
  2959 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2960 the same name in theory Orderings:
  2961 
  2962   less_trans
  2963   less_linear
  2964   le_imp_less_or_eq
  2965   le_less_trans
  2966   less_le_trans
  2967   less_not_sym
  2968   less_asym
  2969 
  2970 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2971 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2972 and different variable names.
  2973 
  2974 * Library/Option_ord.thy: Canonical order on option type.
  2975 
  2976 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2977 finite maps.
  2978 
  2979 * Library/Countable.thy: Type class for countable types.
  2980 
  2981 * Theory Int: The representation of numerals has changed.  The infix
  2982 operator BIT and the bit datatype with constructors B0 and B1 have
  2983 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2984 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2985 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2986 accordingly.
  2987 
  2988 * Theory Nat: definition of <= and < on natural numbers no longer
  2989 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2990 le_def and less_def have disappeared.  Consider lemmas not_less
  2991 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2992 
  2993 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2994 (whose purpose mainly is for various fold_set functionals) have been
  2995 abandoned in favor of the existing algebraic classes
  2996 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2997 lower_semilattice (resp. upper_semilattice) and linorder.
  2998 INCOMPATIBILITY.
  2999 
  3000 * Theory Transitive_Closure: induct and cases rules now declare proper
  3001 case_names ("base" and "step").  INCOMPATIBILITY.
  3002 
  3003 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3004 lattices.  The form set-specific version is available as
  3005 Inductive.lfp_ordinal_induct_set.
  3006 
  3007 * Renamed theorems "power.simps" to "power_int.simps".
  3008 INCOMPATIBILITY.
  3009 
  3010 * Class semiring_div provides basic abstract properties of semirings
  3011 with division and modulo operations.  Subsumes former class dvd_mod.
  3012 
  3013 * Merged theories IntDef, Numeral and IntArith into unified theory
  3014 Int.  INCOMPATIBILITY.
  3015 
  3016 * Theory Library/Code_Index: type "index" now represents natural
  3017 numbers rather than integers.  INCOMPATIBILITY.
  3018 
  3019 * New class "uminus" with operation "uminus" (split of from class
  3020 "minus" which now only has operation "minus", binary).
  3021 INCOMPATIBILITY.
  3022 
  3023 * Constants "card", "internal_split", "option_map" now with authentic
  3024 syntax.  INCOMPATIBILITY.
  3025 
  3026 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3027 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3028 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3029 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3030 Sup_set_def, le_def, less_def, option_map_def now with object
  3031 equality.  INCOMPATIBILITY.
  3032 
  3033 * Records. Removed K_record, and replaced it by pure lambda term
  3034 %x. c. The simplifier setup is now more robust against eta expansion.
  3035 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3036 
  3037 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3038 
  3039 * Library/ListVector: new theory of arithmetic vector operations.
  3040 
  3041 * Library/Order_Relation: new theory of various orderings as sets of
  3042 pairs.  Defines preorders, partial orders, linear orders and
  3043 well-orders on sets and on types.
  3044 
  3045 
  3046 *** ZF ***
  3047 
  3048 * Renamed some theories to allow to loading both ZF and HOL in the
  3049 same session:
  3050 
  3051   Datatype  -> Datatype_ZF
  3052   Inductive -> Inductive_ZF
  3053   Int       -> Int_ZF
  3054   IntDiv    -> IntDiv_ZF
  3055   Nat       -> Nat_ZF
  3056   List      -> List_ZF
  3057   Main      -> Main_ZF
  3058 
  3059 INCOMPATIBILITY: ZF theories that import individual theories below
  3060 Main might need to be adapted.  Regular theory Main is still
  3061 available, as trivial extension of Main_ZF.
  3062 
  3063 
  3064 *** ML ***
  3065 
  3066 * ML within Isar: antiquotation @{const name} or @{const
  3067 name(typargs)} produces statically-checked Const term.
  3068 
  3069 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3070 (of the same name).  Removed obsolete print command.
  3071 
  3072 * Removed obsolete "use_legacy_bindings" function.
  3073 
  3074 * The ``print mode'' is now a thread-local value derived from a global
  3075 template (the former print_mode reference), thus access becomes
  3076 non-critical.  The global print_mode reference is for session
  3077 management only; user-code should use print_mode_value,
  3078 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3079 
  3080 * Functions system/system_out provide a robust way to invoke external
  3081 shell commands, with propagation of interrupts (requires Poly/ML
  3082 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3083 
  3084 
  3085 *** System ***
  3086 
  3087 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3088 in accordance with Proof General 3.7, which prefers GNU emacs.
  3089 
  3090 * isatool tty runs Isabelle process with plain tty interaction;
  3091 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3092 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3093 
  3094 * isatool browser now works with Cygwin as well, using general
  3095 "javapath" function defined in Isabelle process environment.
  3096 
  3097 * YXML notation provides a simple and efficient alternative to
  3098 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3099 isatool yxml as described in the Isabelle system manual.
  3100 
  3101 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3102 provides general wrapper for managing an Isabelle process in a robust
  3103 fashion, with ``cooked'' output from stdin/stderr.
  3104 
  3105 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3106 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3107 
  3108 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3109 way of changing the user's settings is via
  3110 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3111 script.
  3112 
  3113 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3114 cores of the underlying machine, which is a good starting point for
  3115 optimal performance tuning.  The corresponding usedir option -M allows
  3116 "max" as an alias for "0".  WARNING: does not work on certain versions
  3117 of Mac OS (with Poly/ML 5.1).
  3118 
  3119 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3120 adverse effect of Isabelle flooding interactive front-ends (notably
  3121 ProofGeneral / XEmacs).
  3122 
  3123 
  3124 
  3125 New in Isabelle2007 (November 2007)
  3126 -----------------------------------
  3127 
  3128 *** General ***
  3129 
  3130 * More uniform information about legacy features, notably a
  3131 warning/error of "Legacy feature: ...", depending on the state of the
  3132 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3133 legacy features will disappear eventually.
  3134 
  3135 * Theory syntax: the header format ``theory A = B + C:'' has been
  3136 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3137 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3138 
  3139 * Theory syntax: the old non-Isar theory file format has been
  3140 discontinued altogether.  Note that ML proof scripts may still be used
  3141 with Isar theories; migration is usually quite simple with the ML
  3142 function use_legacy_bindings.  INCOMPATIBILITY.
  3143 
  3144 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3145 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3146 quotes.
  3147 
  3148 * Theory loader: be more serious about observing the static theory
  3149 header specifications (including optional directories), but not the
  3150 accidental file locations of previously successful loads.  The strict
  3151 update policy of former update_thy is now already performed by
  3152 use_thy, so the former has been removed; use_thys updates several
  3153 theories simultaneously, just as 'imports' within a theory header
  3154 specification, but without merging the results.  Potential
  3155 INCOMPATIBILITY: may need to refine theory headers and commands
  3156 ROOT.ML which depend on load order.
  3157 
  3158 * Theory loader: optional support for content-based file
  3159 identification, instead of the traditional scheme of full physical
  3160 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3161 (cf. the system manual).  The new scheme allows to work with
  3162 non-finished theories in persistent session images, such that source
  3163 files may be moved later on without requiring reloads.
  3164 
  3165 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3166 file (with the same base name as the theory) are considered a legacy
  3167 feature, which will disappear eventually. Even now, the theory loader
  3168 no longer maintains dependencies on such files.
  3169 
  3170 * Syntax: the scope for resolving ambiguities via type-inference is
  3171 now limited to individual terms, instead of whole simultaneous
  3172 specifications as before. This greatly reduces the complexity of the
  3173 syntax module and improves flexibility by separating parsing and
  3174 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3175 'fixes' etc.) are required in rare situations.
  3176 
  3177 * Syntax: constants introduced by new-style packages ('definition',
  3178 'abbreviation' etc.) are passed through the syntax module in
  3179 ``authentic mode''. This means that associated mixfix annotations
  3180 really stick to such constants, independently of potential name space
  3181 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3182 trees are represented slightly differently, may need to adapt syntax
  3183 translations accordingly. Use CONST marker in 'translations' and
  3184 @{const_syntax} antiquotation in 'parse_translation' etc.
  3185 
  3186 * Legacy goal package: reduced interface to the bare minimum required
  3187 to keep existing proof scripts running.  Most other user-level
  3188 functions are now part of the OldGoals structure, which is *not* open
  3189 by default (consider isatool expandshort before open OldGoals).
  3190 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3191 these tend to cause confusion about the actual goal (!) context being
  3192 used here, which is not necessarily the same as the_context().
  3193 
  3194 * Command 'find_theorems': supports "*" wild-card in "name:"
  3195 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3196 support a specific search form (see ProofGeneral/CHANGES).
  3197 
  3198 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3199 by default, which means that "prems" (and also "fixed variables") are
  3200 suppressed from proof state output.  Note that the ProofGeneral
  3201 settings mechanism allows to change and save options persistently, but
  3202 older versions of Isabelle will fail to start up if a negative prems
  3203 limit is imposed.
  3204 
  3205 * Local theory targets may be specified by non-nested blocks of
  3206 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3207 contain definitions, theorems etc., including any derived mechanism
  3208 that has been implemented on top of these primitives.  This concept
  3209 generalizes the existing ``theorem (in ...)'' towards more versatility
  3210 and scalability.
  3211 
  3212 * Proof General interface: proper undo of final 'end' command;
  3213 discontinued Isabelle/classic mode (ML proof scripts).
  3214 
  3215 
  3216 *** Document preparation ***
  3217 
  3218 * Added antiquotation @{theory name} which prints the given name,
  3219 after checking that it refers to a valid ancestor theory in the
  3220 current context.
  3221 
  3222 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3223 check the given source text as ML type/structure, printing verbatim.
  3224 
  3225 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3226 "c args == rhs" given in the current context.  (Any number of
  3227 arguments may be given on the LHS.)
  3228 
  3229 
  3230 *** Pure ***
  3231 
  3232 * The 'class' package offers a combination of axclass and locale to
  3233 achieve Haskell-like type classes in Isabelle.  Definitions and
  3234 theorems within a class context produce both relative results (with
  3235 implicit parameters according to the locale context), and polymorphic
  3236 constants with qualified polymorphism (according to the class
  3237 context).  Within the body context of a 'class' target, a separate
  3238 syntax layer ("user space type system") takes care of converting
  3239 between global polymorphic consts and internal locale representation.
  3240 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3241 "isatool doc classes" provides a tutorial.
  3242 
  3243 * Generic code generator framework allows to generate executable
  3244 code for ML and Haskell (including Isabelle classes).  A short usage
  3245 sketch:
  3246 
  3247     internal compilation:
  3248         export_code <list of constants (term syntax)> in SML
  3249     writing SML code to a file:
  3250         export_code <list of constants (term syntax)> in SML <filename>
  3251     writing OCaml code to a file:
  3252         export_code <list of constants (term syntax)> in OCaml <filename>
  3253     writing Haskell code to a bunch of files:
  3254         export_code <list of constants (term syntax)> in Haskell <filename>
  3255 
  3256     evaluating closed propositions to True/False using code generation:
  3257         method ``eval''
  3258 
  3259 Reasonable default setup of framework in HOL.
  3260 
  3261 Theorem attributs for selecting and transforming function equations theorems:
  3262 
  3263     [code fun]:        select a theorem as function equation for a specific constant
  3264     [code fun del]:    deselect a theorem as function equation for a specific constant
  3265     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3266     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3267 
  3268 User-defined serializations (target in {SML, OCaml, Haskell}):
  3269 
  3270     code_const <and-list of constants (term syntax)>
  3271       {(target) <and-list of const target syntax>}+
  3272 
  3273     code_type <and-list of type constructors>
  3274       {(target) <and-list of type target syntax>}+
  3275 
  3276     code_instance <and-list of instances>
  3277       {(target)}+
  3278         where instance ::= <type constructor> :: <class>
  3279 
  3280     code_class <and_list of classes>
  3281       {(target) <and-list of class target syntax>}+
  3282         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3283 
  3284 code_instance and code_class only are effective to target Haskell.
  3285 
  3286 For example usage see src/HOL/ex/Codegenerator.thy and
  3287 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3288 generation from Isabelle/HOL theories is available via "isatool doc
  3289 codegen".
  3290 
  3291 * Code generator: consts in 'consts_code' Isar commands are now
  3292 referred to by usual term syntax (including optional type
  3293 annotations).
  3294 
  3295 * Command 'no_translations' removes translation rules from theory
  3296 syntax.
  3297 
  3298 * Overloaded definitions are now actually checked for acyclic
  3299 dependencies.  The overloading scheme is slightly more general than
  3300 that of Haskell98, although Isabelle does not demand an exact
  3301 correspondence to type class and instance declarations.
  3302 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3303 exotic versions of overloading -- at the discretion of the user!
  3304 
  3305 Polymorphic constants are represented via type arguments, i.e. the
  3306 instantiation that matches an instance against the most general
  3307 declaration given in the signature.  For example, with the declaration
  3308 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3309 as c(nat).  Overloading is essentially simultaneous structural
  3310 recursion over such type arguments.  Incomplete specification patterns
  3311 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3312 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3313 Command 'print_theory' outputs the normalized system of recursive
  3314 equations, see section "definitions".
  3315 
  3316 * Configuration options are maintained within the theory or proof
  3317 context (with name and type bool/int/string), providing a very simple
  3318 interface to a poor-man's version of general context data.  Tools may
  3319 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3320 these values using Config.get etc.  Users may change options via an
  3321 associated attribute of the same name.  This form of context
  3322 declaration works particularly well with commands 'declare' or
  3323 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3324 very easy to avoid global references, which would not observe Isar
  3325 toplevel undo/redo and fail to work with multithreading.
  3326 
  3327 Various global ML references of Pure and HOL have been turned into
  3328 configuration options:
  3329 
  3330   Unify.search_bound		unify_search_bound
  3331   Unify.trace_bound		unify_trace_bound
  3332   Unify.trace_simp		unify_trace_simp
  3333   Unify.trace_types		unify_trace_types
  3334   Simplifier.simp_depth_limit	simp_depth_limit
  3335   Blast.depth_limit		blast_depth_limit
  3336   DatatypeProp.dtK		datatype_distinctness_limit
  3337   fast_arith_neq_limit  	fast_arith_neq_limit
  3338   fast_arith_split_limit	fast_arith_split_limit
  3339 
  3340 * Named collections of theorems may be easily installed as context
  3341 data using the functor NamedThmsFun (see also
  3342 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3343 attributes; there is also a toplevel print command.  This facility is
  3344 just a common case of general context data, which is the preferred way
  3345 for anything more complex than just a list of facts in canonical
  3346 order.
  3347 
  3348 * Isar: command 'declaration' augments a local theory by generic
  3349 declaration functions written in ML.  This enables arbitrary content
  3350 being added to the context, depending on a morphism that tells the
  3351 difference of the original declaration context wrt. the application
  3352 context encountered later on.
  3353 
  3354 * Isar: proper interfaces for simplification procedures.  Command
  3355 'simproc_setup' declares named simprocs (with match patterns, and body
  3356 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3357 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3358 
  3359 * Isar: an extra pair of brackets around attribute declarations
  3360 abbreviates a theorem reference involving an internal dummy fact,
  3361 which will be ignored later --- only the effect of the attribute on
  3362 the background context will persist.  This form of in-place
  3363 declarations is particularly useful with commands like 'declare' and
  3364 'using', for example ``have A using [[simproc a]] by simp''.
  3365 
  3366 * Isar: method "assumption" (and implicit closing of subproofs) now
  3367 takes simple non-atomic goal assumptions into account: after applying
  3368 an assumption as a rule the resulting subgoals are solved by atomic
  3369 assumption steps.  This is particularly useful to finish 'obtain'
  3370 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3371 without referring to the original premise "!!x. P x ==> thesis" in the
  3372 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3373 more permissive.
  3374 
  3375 * Isar: implicit use of prems from the Isar proof context is
  3376 considered a legacy feature.  Common applications like ``have A .''
  3377 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3378 referencing facts explicitly here improves readability and
  3379 maintainability of proof texts.
  3380 
  3381 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3382 the obtained context from the course of reasoning!  For example:
  3383 
  3384   assume "EX x y. A x & B y"   -- "any previous fact"
  3385   then guess x and y by clarify
  3386 
  3387 This technique is potentially adventurous, depending on the facts and
  3388 proof tools being involved here.
  3389 
  3390 * Isar: known facts from the proof context may be specified as literal
  3391 propositions, using ASCII back-quote syntax.  This works wherever
  3392 named facts used to be allowed so far, in proof commands, proof
  3393 methods, attributes etc.  Literal facts are retrieved from the context
  3394 according to unification of type and term parameters.  For example,
  3395 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3396 theorems in the current context, then these are valid literal facts:
  3397 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3398 
  3399 There is also a proof method "fact" which does the same composition
  3400 for explicit goal states, e.g. the following proof texts coincide with
  3401 certain special cases of literal facts:
  3402 
  3403   have "A" by fact                 ==  note `A`
  3404   have "A ==> B" by fact           ==  note `A ==> B`
  3405   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3406   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3407 
  3408 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3409 outer syntax.  Thus symbolic identifiers may be used without
  3410 additional white space in declarations like this: ``assume *: A''.
  3411 
  3412 * Isar: 'print_facts' prints all local facts of the current context,
  3413 both named and unnamed ones.
  3414 
  3415 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3416 
  3417   def x == "t" and y == "u"
  3418 
  3419 * Isar: added command 'unfolding', which is structurally similar to
  3420 'using', but affects both the goal state and facts by unfolding given
  3421 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3422 'unfolded' attribute may be replaced by first-class proof text.
  3423 
  3424 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3425 and command 'unfolding' now all support object-level equalities
  3426 (potentially conditional).  The underlying notion of rewrite rule is
  3427 analogous to the 'rule_format' attribute, but *not* that of the
  3428 Simplifier (which is usually more generous).
  3429 
  3430 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3431 premises of a theorem by n. Useful in conjunction with drule.
  3432 
  3433 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3434 method expression within a sandbox consisting of the first N
  3435 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3436 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3437 simplifies all new goals that emerge from applying rule foo to the
  3438 originally first one.
  3439 
  3440 * Isar: schematic goals are no longer restricted to higher-order
  3441 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3442 expected.
  3443 
  3444 * Isar: the conclusion of a long theorem statement is now either
  3445 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3446 (essentially a disjunction of cases with local parameters and
  3447 assumptions).  The latter allows to express general elimination rules
  3448 adequately; in this notation common elimination rules look like this:
  3449 
  3450   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3451     assumes "EX x. P x"
  3452     obtains x where "P x"
  3453 
  3454   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3455     assumes "A & B"
  3456     obtains A and B
  3457 
  3458   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3459     assumes "A | B"
  3460     obtains
  3461       A
  3462     | B
  3463 
  3464 The subsequent classical rules even refer to the formal "thesis"
  3465 explicitly:
  3466 
  3467   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3468     obtains "~ thesis"
  3469 
  3470   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3471     obtains "thesis ==> something"
  3472 
  3473 The actual proof of an 'obtains' statement is analogous to that of the
  3474 Isar proof element 'obtain', only that there may be several cases.
  3475 Optional case names may be specified in parentheses; these will be
  3476 available both in the present proof and as annotations in the
  3477 resulting rule, for later use with the 'cases' method (cf. attribute
  3478 case_names).
  3479 
  3480 * Isar: the assumptions of a long theorem statement are available as
  3481 "assms" fact in the proof context.  This is more appropriate than the
  3482 (historical) "prems", which refers to all assumptions of the current
  3483 context, including those from the target locale, proof body etc.
  3484 
  3485 * Isar: 'print_statement' prints theorems from the current theory or
  3486 proof context in long statement form, according to the syntax of a
  3487 top-level lemma.
  3488 
  3489 * Isar: 'obtain' takes an optional case name for the local context
  3490 introduction rule (default "that").
  3491 
  3492 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3493 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3494 to occur.
  3495 
  3496 * Pure: syntax "CONST name" produces a fully internalized constant
  3497 according to the current context.  This is particularly useful for
  3498 syntax translations that should refer to internal constant
  3499 representations independently of name spaces.
  3500 
  3501 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3502 instead of "FOO ". This allows multiple binder declarations to coexist
  3503 in the same context.  INCOMPATIBILITY.
  3504 
  3505 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3506 primitive that also works in a locale context (both for constants and
  3507 fixed variables). Type declaration and internal syntactic representation
  3508 of given constants retrieved from the context. Likewise, the
  3509 'no_notation' command allows to remove given syntax annotations from the
  3510 current context.
  3511 
  3512 * Isar/locales: new derived specification elements 'axiomatization',
  3513 'definition', 'abbreviation', which support type-inference, admit
  3514 object-level specifications (equality, equivalence).  See also the
  3515 isar-ref manual.  Examples:
  3516 
  3517   axiomatization
  3518     eq  (infix "===" 50) where
  3519     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3520 
  3521   definition "f x y = x + y + 1"
  3522   definition g where "g x = f x x"
  3523 
  3524   abbreviation
  3525     neq  (infix "=!=" 50) where
  3526     "x =!= y == ~ (x === y)"
  3527 
  3528 These specifications may be also used in a locale context.  Then the
  3529 constants being introduced depend on certain fixed parameters, and the
  3530 constant name is qualified by the locale base name.  An internal
  3531 abbreviation takes care for convenient input and output, making the
  3532 parameters implicit and using the original short name.  See also
  3533 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3534 entities from a monomorphic theory.
  3535 
  3536 Presently, abbreviations are only available 'in' a target locale, but
  3537 not inherited by general import expressions.  Also note that
  3538 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3539 'translations' in common applications.  The "no_abbrevs" print mode
  3540 prevents folding of abbreviations in term output.
  3541 
  3542 Concrete syntax is attached to specified constants in internal form,
  3543 independently of name spaces.  The parse tree representation is
  3544 slightly different -- use 'notation' instead of raw 'syntax', and
  3545 'translations' with explicit "CONST" markup to accommodate this.
  3546 
  3547 * Pure/Isar: unified syntax for new-style specification mechanisms
  3548 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3549 full type inference and dummy patterns ("_").  For example:
  3550 
  3551   definition "K x _ = x"
  3552 
  3553   inductive conj for A B
  3554   where "A ==> B ==> conj A B"
  3555 
  3556 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3557 the current context.  Print mode "no_abbrevs" prevents inversion of
  3558 abbreviations on output.
  3559 
  3560 * Isar/locales: improved parameter handling: use of locales "var" and
  3561 "struct" no longer necessary; - parameter renamings are no longer
  3562 required to be injective.  For example, this allows to define
  3563 endomorphisms as locale endom = homom mult mult h.
  3564 
  3565 * Isar/locales: changed the way locales with predicates are defined.
  3566 Instead of accumulating the specification, the imported expression is
  3567 now an interpretation.  INCOMPATIBILITY: different normal form of
  3568 locale expressions.  In particular, in interpretations of locales with
  3569 predicates, goals repesenting already interpreted fragments are not
  3570 removed automatically.  Use methods `intro_locales' and
  3571 `unfold_locales'; see below.
  3572 
  3573 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3574 provide backward reasoning on locales predicates.  The methods are
  3575 aware of interpretations and discharge corresponding goals.
  3576 `intro_locales' is less aggressive then `unfold_locales' and does not
  3577 unfold predicates to assumptions.
  3578 
  3579 * Isar/locales: the order in which locale fragments are accumulated
  3580 has changed.  This enables to override declarations from fragments due
  3581 to interpretations -- for example, unwanted simp rules.
  3582 
  3583 * Isar/locales: interpretation in theories and proof contexts has been
  3584 extended.  One may now specify (and prove) equations, which are
  3585 unfolded in interpreted theorems.  This is useful for replacing
  3586 defined concepts (constants depending on locale parameters) by
  3587 concepts already existing in the target context.  Example:
  3588 
  3589   interpretation partial_order ["op <= :: [int, int] => bool"]
  3590     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3591 
  3592 Typically, the constant `partial_order.less' is created by a
  3593 definition specification element in the context of locale
  3594 partial_order.
  3595 
  3596 * Method "induct": improved internal context management to support
  3597 local fixes and defines on-the-fly. Thus explicit meta-level
  3598 connectives !!  and ==> are rarely required anymore in inductive goals
  3599 (using object-logic connectives for this purpose has been long
  3600 obsolete anyway). Common proof patterns are explained in
  3601 src/HOL/Induct/Common_Patterns.thy, see also
  3602 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3603 examples.
  3604 
  3605 * Method "induct": improved handling of simultaneous goals. Instead of
  3606 introducing object-level conjunction, the statement is now split into
  3607 several conclusions, while the corresponding symbolic cases are nested
  3608 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3609 see src/HOL/Induct/Common_Patterns.thy, for example.
  3610 
  3611 * Method "induct": mutual induction rules are now specified as a list
  3612 of rule sharing the same induction cases. HOL packages usually provide
  3613 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3614 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3615 mutual induction rules differently, i.e. like this:
  3616 
  3617   (induct rule: foo_bar.inducts)
  3618   (induct set: foo bar)
  3619   (induct pred: foo bar)
  3620   (induct type: foo bar)
  3621 
  3622 The ML function ProjectRule.projections turns old-style rules into the
  3623 new format.
  3624 
  3625 * Method "coinduct": dual of induction, see
  3626 src/HOL/Library/Coinductive_List.thy for various examples.
  3627 
  3628 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3629 considered a legacy feature.
  3630 
  3631 * Attribute "symmetric" produces result with standardized schematic
  3632 variables (index 0).  Potential INCOMPATIBILITY.
  3633 
  3634 * Simplifier: by default the simplifier trace only shows top level
  3635 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3636 default. Thus there is less danger of being flooded by the trace. The
  3637 trace indicates where parts have been suppressed.
  3638   
  3639 * Provers/classical: removed obsolete classical version of elim_format
  3640 attribute; classical elim/dest rules are now treated uniformly when
  3641 manipulating the claset.
  3642 
  3643 * Provers/classical: stricter checks to ensure that supplied intro,
  3644 dest and elim rules are well-formed; dest and elim rules must have at
  3645 least one premise.
  3646 
  3647 * Provers/classical: attributes dest/elim/intro take an optional
  3648 weight argument for the rule (just as the Pure versions).  Weights are
  3649 ignored by automated tools, but determine the search order of single
  3650 rule steps.
  3651 
  3652 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3653 where the body does not mention the bound variable.  Note that dummy
  3654 patterns implicitly depend on their context of bounds, which makes
  3655 "{_. _}" match any set comprehension as expected.  Potential
  3656 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3657 constant "_idtdummy" in the binding position.
  3658 
  3659 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3660 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3661 for example "A -> B" => "Pi A (%_. B)".
  3662 
  3663 * Pure: 'class_deps' command visualizes the subclass relation, using
  3664 the graph browser tool.
  3665 
  3666 * Pure: 'print_theory' now suppresses certain internal declarations by
  3667 default; use '!' option for full details.
  3668 
  3669 
  3670 *** HOL ***
  3671 
  3672 * Method "metis" proves goals by applying the Metis general-purpose
  3673 resolution prover (see also http://gilith.com/software/metis/).
  3674 Examples are in the directory MetisExamples.  WARNING: the
  3675 Isabelle/HOL-Metis integration does not yet work properly with
  3676 multi-threading.
  3677   
  3678 * Command 'sledgehammer' invokes external automatic theorem provers as
  3679 background processes.  It generates calls to the "metis" method if
  3680 successful. These can be pasted into the proof.  Users do not have to
  3681 wait for the automatic provers to return.  WARNING: does not really
  3682 work with multi-threading.
  3683 
  3684 * New "auto_quickcheck" feature tests outermost goal statements for
  3685 potential counter-examples.  Controlled by ML references
  3686 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3687 5000 milliseconds).  Fails silently if statements is outside of
  3688 executable fragment, or any other codgenerator problem occurs.
  3689 
  3690 * New constant "undefined" with axiom "undefined x = undefined".
  3691 
  3692 * Added class "HOL.eq", allowing for code generation with polymorphic
  3693 equality.
  3694 
  3695 * Some renaming of class constants due to canonical name prefixing in
  3696 the new 'class' package:
  3697 
  3698     HOL.abs ~> HOL.abs_class.abs
  3699     HOL.divide ~> HOL.divide_class.divide
  3700     0 ~> HOL.zero_class.zero
  3701     1 ~> HOL.one_class.one
  3702     op + ~> HOL.plus_class.plus
  3703     op - ~> HOL.minus_class.minus
  3704     uminus ~> HOL.minus_class.uminus
  3705     op * ~> HOL.times_class.times
  3706     op < ~> HOL.ord_class.less
  3707     op <= > HOL.ord_class.less_eq
  3708     Nat.power ~> Power.power_class.power
  3709     Nat.size ~> Nat.size_class.size
  3710     Numeral.number_of ~> Numeral.number_class.number_of
  3711     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3712     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3713     Orderings.min ~> Orderings.ord_class.min
  3714     Orderings.max ~> Orderings.ord_class.max
  3715     Divides.op div ~> Divides.div_class.div
  3716     Divides.op mod ~> Divides.div_class.mod
  3717     Divides.op dvd ~> Divides.div_class.dvd
  3718 
  3719 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3720 
  3721 a) User-defined constants using any of the names "plus", "minus",
  3722 "times", "less" or "less_eq". The standard syntax translations for
  3723 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3724 names.
  3725 
  3726 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3727 INCOMPATIBILITY: use more specific names.
  3728 
  3729 c) Permutative equations (e.g. "a + b = b + a")
  3730 Since the change of names also changes the order of terms, permutative
  3731 rewrite rules may get applied in a different order. Experience shows
  3732 that this is rarely the case (only two adaptions in the whole Isabelle
  3733 distribution).  INCOMPATIBILITY: rewrite proofs
  3734 
  3735 d) ML code directly refering to constant names
  3736 This in general only affects hand-written proof tactics, simprocs and
  3737 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3738 Consider using @{const_name} antiquotation.
  3739 
  3740 * New class "default" with associated constant "default".
  3741 
  3742 * Function "sgn" is now overloaded and available on int, real, complex
  3743 (and other numeric types), using class "sgn".  Two possible defs of
  3744 sgn are given as equational assumptions in the classes sgn_if and
  3745 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3746 INCOMPATIBILITY.
  3747 
  3748 * Locale "partial_order" now unified with class "order" (cf. theory
  3749 Orderings), added parameter "less".  INCOMPATIBILITY.
  3750 
  3751 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3752 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3753 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3754 
  3755 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3756 changed order of proof goals in instance proofs.
  3757 
  3758 * The transitivity reasoner for partial and linear orders is set up
  3759 for classes "order" and "linorder".  Instances of the reasoner are available
  3760 in all contexts importing or interpreting the corresponding locales.
  3761 Method "order" invokes the reasoner separately; the reasoner
  3762 is also integrated with the Simplifier as a solver.  Diagnostic
  3763 command 'print_orders' shows the available instances of the reasoner
  3764 in the current context.
  3765 
  3766 * Localized monotonicity predicate in theory "Orderings"; integrated
  3767 lemmas max_of_mono and min_of_mono with this predicate.
  3768 INCOMPATIBILITY.
  3769 
  3770 * Formulation of theorem "dense" changed slightly due to integration
  3771 with new class dense_linear_order.
  3772 
  3773 * Uniform lattice theory development in HOL.
  3774 
  3775     constants "meet" and "join" now named "inf" and "sup"
  3776     constant "Meet" now named "Inf"
  3777 
  3778     classes "meet_semilorder" and "join_semilorder" now named
  3779       "lower_semilattice" and "upper_semilattice"
  3780     class "lorder" now named "lattice"
  3781     class "comp_lat" now named "complete_lattice"
  3782 
  3783     Instantiation of lattice classes allows explicit definitions
  3784     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3785 
  3786   INCOMPATIBILITY.  Theorem renames:
  3787 
  3788     meet_left_le            ~> inf_le1
  3789     meet_right_le           ~> inf_le2
  3790     join_left_le            ~> sup_ge1
  3791     join_right_le           ~> sup_ge2
  3792     meet_join_le            ~> inf_sup_ord
  3793     le_meetI                ~> le_infI
  3794     join_leI                ~> le_supI
  3795     le_meet                 ~> le_inf_iff
  3796     le_join                 ~> ge_sup_conv
  3797     meet_idempotent         ~> inf_idem
  3798     join_idempotent         ~> sup_idem
  3799     meet_comm               ~> inf_commute
  3800     join_comm               ~> sup_commute
  3801     meet_leI1               ~> le_infI1
  3802     meet_leI2               ~> le_infI2
  3803     le_joinI1               ~> le_supI1
  3804     le_joinI2               ~> le_supI2
  3805     meet_assoc              ~> inf_assoc
  3806     join_assoc              ~> sup_assoc
  3807     meet_left_comm          ~> inf_left_commute
  3808     meet_left_idempotent    ~> inf_left_idem
  3809     join_left_comm          ~> sup_left_commute
  3810     join_left_idempotent    ~> sup_left_idem
  3811     meet_aci                ~> inf_aci
  3812     join_aci                ~> sup_aci
  3813     le_def_meet             ~> le_iff_inf
  3814     le_def_join             ~> le_iff_sup
  3815     join_absorp2            ~> sup_absorb2
  3816     join_absorp1            ~> sup_absorb1
  3817     meet_absorp1            ~> inf_absorb1
  3818     meet_absorp2            ~> inf_absorb2
  3819     meet_join_absorp        ~> inf_sup_absorb
  3820     join_meet_absorp        ~> sup_inf_absorb
  3821     distrib_join_le         ~> distrib_sup_le
  3822     distrib_meet_le         ~> distrib_inf_le
  3823 
  3824     add_meet_distrib_left   ~> add_inf_distrib_left
  3825     add_join_distrib_left   ~> add_sup_distrib_left
  3826     is_join_neg_meet        ~> is_join_neg_inf
  3827     is_meet_neg_join        ~> is_meet_neg_sup
  3828     add_meet_distrib_right  ~> add_inf_distrib_right
  3829     add_join_distrib_right  ~> add_sup_distrib_right
  3830     add_meet_join_distribs  ~> add_sup_inf_distribs
  3831     join_eq_neg_meet        ~> sup_eq_neg_inf
  3832     meet_eq_neg_join        ~> inf_eq_neg_sup
  3833     add_eq_meet_join        ~> add_eq_inf_sup
  3834     meet_0_imp_0            ~> inf_0_imp_0
  3835     join_0_imp_0            ~> sup_0_imp_0
  3836     meet_0_eq_0             ~> inf_0_eq_0
  3837     join_0_eq_0             ~> sup_0_eq_0
  3838     neg_meet_eq_join        ~> neg_inf_eq_sup
  3839     neg_join_eq_meet        ~> neg_sup_eq_inf
  3840     join_eq_if              ~> sup_eq_if
  3841 
  3842     mono_meet               ~> mono_inf
  3843     mono_join               ~> mono_sup
  3844     meet_bool_eq            ~> inf_bool_eq
  3845     join_bool_eq            ~> sup_bool_eq
  3846     meet_fun_eq             ~> inf_fun_eq
  3847     join_fun_eq             ~> sup_fun_eq
  3848     meet_set_eq             ~> inf_set_eq
  3849     join_set_eq             ~> sup_set_eq
  3850     meet1_iff               ~> inf1_iff
  3851     meet2_iff               ~> inf2_iff
  3852     meet1I                  ~> inf1I
  3853     meet2I                  ~> inf2I
  3854     meet1D1                 ~> inf1D1
  3855     meet2D1                 ~> inf2D1
  3856     meet1D2                 ~> inf1D2
  3857     meet2D2                 ~> inf2D2
  3858     meet1E                  ~> inf1E
  3859     meet2E                  ~> inf2E
  3860     join1_iff               ~> sup1_iff
  3861     join2_iff               ~> sup2_iff
  3862     join1I1                 ~> sup1I1
  3863     join2I1                 ~> sup2I1
  3864     join1I1                 ~> sup1I1
  3865     join2I2                 ~> sup1I2
  3866     join1CI                 ~> sup1CI
  3867     join2CI                 ~> sup2CI
  3868     join1E                  ~> sup1E
  3869     join2E                  ~> sup2E
  3870 
  3871     is_meet_Meet            ~> is_meet_Inf
  3872     Meet_bool_def           ~> Inf_bool_def
  3873     Meet_fun_def            ~> Inf_fun_def
  3874     Meet_greatest           ~> Inf_greatest
  3875     Meet_lower              ~> Inf_lower
  3876     Meet_set_def            ~> Inf_set_def
  3877 
  3878     Sup_def                 ~> Sup_Inf
  3879     Sup_bool_eq             ~> Sup_bool_def
  3880     Sup_fun_eq              ~> Sup_fun_def
  3881     Sup_set_eq              ~> Sup_set_def
  3882 
  3883     listsp_meetI            ~> listsp_infI
  3884     listsp_meet_eq          ~> listsp_inf_eq
  3885 
  3886     meet_min                ~> inf_min
  3887     join_max                ~> sup_max
  3888 
  3889 * Added syntactic class "size"; overloaded constant "size" now has
  3890 type "'a::size ==> bool"
  3891 
  3892 * Internal reorganisation of `size' of datatypes: size theorems
  3893 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3894 simplification rules by default!); theorems "prod.size" now named
  3895 "*.size".
  3896 
  3897 * Class "div" now inherits from class "times" rather than "type".
  3898 INCOMPATIBILITY.
  3899 
  3900 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3901 Linorder etc.  have disappeared; operations defined in terms of
  3902 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3903 
  3904 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3905 
  3906 * HOL-Word: New extensive library and type for generic, fixed size
  3907 machine words, with arithemtic, bit-wise, shifting and rotating
  3908 operations, reflection into int, nat, and bool lists, automation for
  3909 linear arithmetic (by automatic reflection into nat or int), including
  3910 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3911 arithmetic type classes, supporting automatic simplification of
  3912 numerals on all operations.
  3913 
  3914 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3915 
  3916 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3917 
  3918 * Code generator library theories:
  3919   - Code_Integer represents HOL integers by big integer literals in target
  3920     languages.
  3921   - Code_Char represents HOL characters by character literals in target
  3922     languages.
  3923   - Code_Char_chr like Code_Char, but also offers treatment of character
  3924     codes; includes Code_Integer.
  3925   - Executable_Set allows to generate code for finite sets using lists.
  3926   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3927     denominator).
  3928   - Executable_Real implements a subset of real numbers, namly those
  3929     representable by rational numbers.
  3930   - Efficient_Nat implements natural numbers by integers, which in general will
  3931     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3932     includes Code_Integer.
  3933   - Code_Index provides an additional datatype index which is mapped to
  3934     target-language built-in integers.
  3935   - Code_Message provides an additional datatype message_string which is isomorphic to
  3936     strings; messages are mapped to target-language strings.
  3937 
  3938 * New package for inductive predicates
  3939 
  3940   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3941 
  3942     inductive
  3943       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3944       for z_1 :: U_1 and ... and z_n :: U_m
  3945     where
  3946       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3947     | ...
  3948 
  3949   with full support for type-inference, rather than
  3950 
  3951     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3952 
  3953     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3954     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3955 
  3956     inductive "s z_1 ... z_m"
  3957     intros
  3958       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3959       ...
  3960 
  3961   For backward compatibility, there is a wrapper allowing inductive
  3962   sets to be defined with the new package via
  3963 
  3964     inductive_set
  3965       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3966       for z_1 :: U_1 and ... and z_n :: U_m
  3967     where
  3968       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3969     | ...
  3970 
  3971   or
  3972 
  3973     inductive_set
  3974       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3975       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3976       for z_1 :: U_1 and ... and z_n :: U_m
  3977     where
  3978       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3979     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3980     | ...
  3981 
  3982   if the additional syntax "p ..." is required.
  3983 
  3984   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3985   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3986 
  3987   INCOMPATIBILITIES:
  3988 
  3989   - Since declaration and definition of inductive sets or predicates
  3990     is no longer separated, abbreviations involving the newly
  3991     introduced sets or predicates must be specified together with the
  3992     introduction rules after the 'where' keyword (see above), rather
  3993     than before the actual inductive definition.
  3994 
  3995   - The variables in induction and elimination rules are now
  3996     quantified in the order of their occurrence in the introduction
  3997     rules, rather than in alphabetical order. Since this may break
  3998     some proofs, these proofs either have to be repaired, e.g. by
  3999     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4000     statements of the form
  4001 
  4002       case (rule_i a_i_1 ... a_i_{k_i})
  4003 
  4004     or the old order of quantification has to be restored by explicitly adding
  4005     meta-level quantifiers in the introduction rules, i.e.
  4006 
  4007       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4008 
  4009   - The format of the elimination rules is now
  4010 
  4011       p z_1 ... z_m x_1 ... x_n ==>
  4012         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4013         ==> ... ==> P
  4014 
  4015     for predicates and
  4016 
  4017       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4018         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4019         ==> ... ==> P
  4020 
  4021     for sets rather than
  4022 
  4023       x : s z_1 ... z_m ==>
  4024         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4025         ==> ... ==> P
  4026 
  4027     This may require terms in goals to be expanded to n-tuples
  4028     (e.g. using case_tac or simplification with the split_paired_all
  4029     rule) before the above elimination rule is applicable.
  4030 
  4031   - The elimination or case analysis rules for (mutually) inductive
  4032     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4033     list of rules "p_1_..._p_k.elims" is no longer available.
  4034 
  4035 * New package "function"/"fun" for general recursive functions,
  4036 supporting mutual and nested recursion, definitions in local contexts,
  4037 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4038 for small examples, and the separate tutorial on the function
  4039 package. The old recdef "package" is still available as before, but
  4040 users are encouraged to use the new package.
  4041 
  4042 * Method "lexicographic_order" automatically synthesizes termination
  4043 relations as lexicographic combinations of size measures. 
  4044 
  4045 * Case-expressions allow arbitrary constructor-patterns (including
  4046 "_") and take their order into account, like in functional
  4047 programming.  Internally, this is translated into nested
  4048 case-expressions; missing cases are added and mapped to the predefined
  4049 constant "undefined". In complicated cases printing may no longer show
  4050 the original input but the internal form. Lambda-abstractions allow
  4051 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4052 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4053 variable.
  4054 
  4055 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4056 is an abbreviation for "of_nat :: nat => int". The simplification
  4057 rules for "of_nat" have been changed to work like "int" did
  4058 previously.  Potential INCOMPATIBILITY:
  4059   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4060   - of_nat_diff and of_nat_mult are no longer default simp rules
  4061 
  4062 * Method "algebra" solves polynomial equations over (semi)rings using
  4063 Groebner bases. The (semi)ring structure is defined by locales and the
  4064 tool setup depends on that generic context. Installing the method for
  4065 a specific type involves instantiating the locale and possibly adding
  4066 declarations for computation on the coefficients.  The method is
  4067 already instantiated for natural numbers and for the axiomatic class
  4068 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4069 CALCULEMUS 2007 for the general principles underlying this
  4070 architecture of context-aware proof-tools.
  4071 
  4072 * Method "ferrack" implements quantifier elimination over
  4073 special-purpose dense linear orders using locales (analogous to
  4074 "algebra"). The method is already installed for class
  4075 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4076 rat, etc.
  4077 
  4078 * Former constant "List.op @" now named "List.append".  Use ML
  4079 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4080 circumvent possible incompatibilities when working on ML level.
  4081 
  4082 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4083 
  4084 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4085 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4086 
  4087 * New syntax for Haskell-like list comprehension (input only), eg.
  4088 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4089 
  4090 * The special syntax for function "filter" has changed from [x :
  4091 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4092 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4093 
  4094 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4095 defined on nat only, as an abbreviation for [a..<Suc b]
  4096 INCOMPATIBILITY.
  4097 
  4098 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4099 
  4100 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4101 
  4102 * New lemma collection field_simps (an extension of ring_simps) for
  4103 manipulating (in)equations involving division. Multiplies with all
  4104 denominators that can be proved to be non-zero (in equations) or
  4105 positive/negative (in inequations).
  4106 
  4107 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4108 have been improved and renamed to ring_simps, group_simps and
  4109 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4110 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4111 
  4112 * Theory Library/Commutative_Ring: switched from recdef to function
  4113 package; constants add, mul, pow now curried.  Infix syntax for
  4114 algebraic operations.
  4115 
  4116 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4117 INCOMPATIBILITY.
  4118 
  4119 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4120 INCOMPATIBILITY.
  4121 
  4122 * HOL/records: generalised field-update to take a function on the
  4123 field rather than the new value: r(|A := x|) is translated to A_update
  4124 (K x) r The K-combinator that is internally used is called K_record.
  4125 INCOMPATIBILITY: Usage of the plain update functions has to be
  4126 adapted.
  4127  
  4128 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4129 * x = 0, which are required for a semiring.  Richer structures do not
  4130 inherit from semiring_0 anymore, because this property is a theorem
  4131 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4132 there is more to prove, but this is mostly trivial.
  4133 
  4134 * Class "recpower" is generalized to arbitrary monoids, not just
  4135 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4136 commutativity or semiring properties additionally.
  4137 
  4138 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4139 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4140 better use 'abbreviation'.
  4141 
  4142 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4143 
  4144 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4145 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4146 significant changes for setting up numeral syntax for types:
  4147   - New constants Numeral.pred and Numeral.succ instead
  4148       of former Numeral.bin_pred and Numeral.bin_succ.
  4149   - Use integer operations instead of bin_add, bin_mult and so on.
  4150   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4151   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4152 
  4153 See src/HOL/Integ/IntArith.thy for an example setup.
  4154 
  4155 * Command 'normal_form' computes the normal form of a term that may
  4156 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4157 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4158 heavy-duty computations because the functions are compiled to ML
  4159 first.  Correspondingly, a method "normalization" is provided.  See
  4160 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4161 
  4162 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4163 25 like -->); output depends on the "iff" print_mode, the default is
  4164 "A = B" (with priority 50).
  4165 
  4166 * Relations less (<) and less_eq (<=) are also available on type bool.
  4167 Modified syntax to disallow nesting without explicit parentheses,
  4168 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4169 INCOMPATIBILITY.
  4170 
  4171 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4172 
  4173 * Relation composition operator "op O" now has precedence 75 and binds
  4174 stronger than union and intersection. INCOMPATIBILITY.
  4175 
  4176 * The old set interval syntax "{m..n(}" (and relatives) has been
  4177 removed.  Use "{m..<n}" (and relatives) instead.
  4178 
  4179 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4180 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4181 ``declare [[simproc del: neq]]''.
  4182 
  4183 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4184 True/False.
  4185 
  4186 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4187 
  4188 * Theorem setsum_mult renamed to setsum_right_distrib.
  4189 
  4190 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4191 ``rule'' method.
  4192 
  4193 * Reimplemented methods "sat" and "satx", with several improvements:
  4194 goals no longer need to be stated as "<prems> ==> False", equivalences
  4195 (i.e. "=" on type bool) are handled, variable names of the form
  4196 "lit_<n>" are no longer reserved, significant speedup.
  4197 
  4198 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4199 zChaff is still supported as well.
  4200 
  4201 * 'inductive' and 'datatype': provide projections of mutual rules,
  4202 bundled as foo_bar.inducts;
  4203 
  4204 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4205 Library.
  4206 
  4207 * Library: moved theory Accessible_Part to main HOL.
  4208 
  4209 * Library: added theory Coinductive_List of potentially infinite lists
  4210 as greatest fixed-point.
  4211 
  4212 * Library: added theory AssocList which implements (finite) maps as
  4213 association lists.
  4214 
  4215 * Method "evaluation" solves goals (i.e. a boolean expression)
  4216 efficiently by compiling it to ML.  The goal is "proved" (via an
  4217 oracle) if it evaluates to True.
  4218 
  4219 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4220 also when invoked by the simplifier.  This results in the Simplifier
  4221 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4222 Configuration option fast_arith_split_limit=0 recovers the old
  4223 behavior.
  4224 
  4225 * Support for hex (0x20) and binary (0b1001) numerals.
  4226 
  4227 * New method: reify eqs (t), where eqs are equations for an
  4228 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4229 parameter, computes a term s::'b and a list xs::'a list and proves the
  4230 theorem I xs s = t. This is also known as reification or quoting. The
  4231 resulting theorem is applied to the subgoal to substitute t with I xs
  4232 s.  If t is omitted, the subgoal itself is reified.
  4233 
  4234 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4235 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4236 where f is supposed to be a computable function (in the sense of code
  4237 generattion). The method uses reify to compute s and xs as above then
  4238 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4239 r and finally gets the theorem t = r, which is again applied to the
  4240 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4241 
  4242 * Reflection: Automatic reification now handels binding, an example is
  4243 available in src/HOL/ex/ReflectionEx.thy
  4244 
  4245 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4246 command 'statespace' that is similar to 'record', but introduces an
  4247 abstract specification based on the locale infrastructure instead of
  4248 HOL types.  This leads to extra flexibility in composing state spaces,
  4249 in particular multiple inheritance and renaming of components.
  4250 
  4251 
  4252 *** HOL-Complex ***
  4253 
  4254 * Hyperreal: Functions root and sqrt are now defined on negative real
  4255 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4256 Nonnegativity side conditions have been removed from many lemmas, so
  4257 that more subgoals may now be solved by simplification; potential
  4258 INCOMPATIBILITY.
  4259 
  4260 * Real: new type classes formalize real normed vector spaces and
  4261 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4262 and norm :: 'a => real.
  4263 
  4264 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4265 reals into other types. The overloaded constant Reals :: 'a set is now
  4266 defined as range of_real; potential INCOMPATIBILITY.
  4267 
  4268 * Real: proper support for ML code generation, including 'quickcheck'.
  4269 Reals are implemented as arbitrary precision rationals.
  4270 
  4271 * Hyperreal: Several constants that previously worked only for the
  4272 reals have been generalized, so they now work over arbitrary vector
  4273 spaces. Type annotations may need to be added in some cases; potential
  4274 INCOMPATIBILITY.
  4275 
  4276   Infinitesimal  :: ('a::real_normed_vector) star set
  4277   HFinite        :: ('a::real_normed_vector) star set
  4278   HInfinite      :: ('a::real_normed_vector) star set
  4279   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4280   monad          :: ('a::real_normed_vector) star => 'a star set
  4281   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4282   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4283   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4284   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4285   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4286   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4287   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4288   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4289   sgn            :: 'a::real_normed_vector => 'a
  4290   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4291 
  4292 * Complex: Some complex-specific constants are now abbreviations for
  4293 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4294 hnorm.  Other constants have been entirely removed in favor of the
  4295 polymorphic versions (INCOMPATIBILITY):
  4296 
  4297   approx        <-- capprox
  4298   HFinite       <-- CFinite
  4299   HInfinite     <-- CInfinite
  4300   Infinitesimal <-- CInfinitesimal
  4301   monad         <-- cmonad
  4302   galaxy        <-- cgalaxy
  4303   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4304   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4305   (ns)deriv     <-- (ns)cderiv
  4306 
  4307 
  4308 *** HOL-Algebra ***
  4309 
  4310 * Formalisation of ideals and the quotient construction over rings.
  4311 
  4312 * Order and lattice theory no longer based on records.
  4313 INCOMPATIBILITY.
  4314 
  4315 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4316 greatest_closed.  INCOMPATIBILITY.
  4317 
  4318 * Method algebra is now set up via an attribute.  For examples see
  4319 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4320 of algebraic structures.
  4321 
  4322 * Renamed theory CRing to Ring.
  4323 
  4324 
  4325 *** HOL-Nominal ***
  4326 
  4327 * Substantial, yet incomplete support for nominal datatypes (binding
  4328 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4329 src/HOL/Nominal/Examples.  Prospective users should consult
  4330 http://isabelle.in.tum.de/nominal/
  4331 
  4332 
  4333 *** ML ***
  4334 
  4335 * ML basics: just one true type int, which coincides with IntInf.int
  4336 (even on SML/NJ).
  4337 
  4338 * ML within Isar: antiquotations allow to embed statically-checked
  4339 formal entities in the source, referring to the context available at
  4340 compile-time.  For example:
  4341 
  4342 ML {* @{sort "{zero,one}"} *}
  4343 ML {* @{typ "'a => 'b"} *}
  4344 ML {* @{term "%x. x"} *}
  4345 ML {* @{prop "x == y"} *}
  4346 ML {* @{ctyp "'a => 'b"} *}
  4347 ML {* @{cterm "%x. x"} *}
  4348 ML {* @{cprop "x == y"} *}
  4349 ML {* @{thm asm_rl} *}
  4350 ML {* @{thms asm_rl} *}
  4351 ML {* @{type_name c} *}
  4352 ML {* @{type_syntax c} *}
  4353 ML {* @{const_name c} *}
  4354 ML {* @{const_syntax c} *}
  4355 ML {* @{context} *}
  4356 ML {* @{theory} *}
  4357 ML {* @{theory Pure} *}
  4358 ML {* @{theory_ref} *}
  4359 ML {* @{theory_ref Pure} *}
  4360 ML {* @{simpset} *}
  4361 ML {* @{claset} *}
  4362 ML {* @{clasimpset} *}
  4363 
  4364 The same works for sources being ``used'' within an Isar context.
  4365 
  4366 * ML in Isar: improved error reporting; extra verbosity with
  4367 ML_Context.trace enabled.
  4368 
  4369 * Pure/General/table.ML: the join operations now works via exceptions
  4370 DUP/SAME instead of type option. This is simpler in simple cases, and
  4371 admits slightly more efficient complex applications.
  4372 
  4373 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4374 use Context.generic instead of just theory.
  4375 
  4376 * Pure: datatype Context.generic joins theory/Proof.context and
  4377 provides some facilities for code that works in either kind of
  4378 context, notably GenericDataFun for uniform theory and proof data.
  4379 
  4380 * Pure: simplified internal attribute type, which is now always
  4381 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4382 local (Proof.context) attributes have been discontinued, while
  4383 minimizing code duplication. Thm.rule_attribute and
  4384 Thm.declaration_attribute build canonical attributes; see also structure
  4385 Context for further operations on Context.generic, notably
  4386 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4387 declarations and definitions.
  4388 
  4389 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4390 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4391 init only required for impure data. INCOMPATIBILITY: empty really need
  4392 to be empty (no dependencies on theory content!)
  4393 
  4394 * Pure/kernel: consts certification ignores sort constraints given in
  4395 signature declarations. (This information is not relevant to the
  4396 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4397 potential INCOMPATIBILITY.
  4398 
  4399 * Pure: axiomatic type classes are now purely definitional, with
  4400 explicit proofs of class axioms and super class relations performed
  4401 internally. See Pure/axclass.ML for the main internal interfaces --
  4402 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4403 AxClass.axiomatize_class/classrel/arity supersede
  4404 Sign.add_classes/classrel/arities.
  4405 
  4406 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4407 global/local versions on theory vs. Proof.context have been
  4408 discontinued; Attrib.syntax and Method.syntax have been adapted
  4409 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4410 attributes, methods, etc.
  4411 
  4412 * Pure: several functions of signature "... -> theory -> theory * ..."
  4413 have been reoriented to "... -> theory -> ... * theory" in order to
  4414 allow natural usage in combination with the ||>, ||>>, |-> and
  4415 fold_map combinators.
  4416 
  4417 * Pure: official theorem names (closed derivations) and additional
  4418 comments (tags) are now strictly separate.  Name hints -- which are
  4419 maintained as tags -- may be attached any time without affecting the
  4420 derivation.
  4421 
  4422 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4423 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4424 achieve the old behaviour.
  4425 
  4426 * Pure: the "Goal" constant is now called "prop", supporting a
  4427 slightly more general idea of ``protecting'' meta-level rule
  4428 statements.
  4429 
  4430 * Pure: Logic.(un)varify only works in a global context, which is now
  4431 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4432 Logic.legacy_(un)varify as temporary workaround.
  4433 
  4434 * Pure: structure Name provides scalable operations for generating
  4435 internal variable names, notably Name.variants etc.  This replaces
  4436 some popular functions from term.ML:
  4437 
  4438   Term.variant		->  Name.variant
  4439   Term.variantlist	->  Name.variant_list
  4440   Term.invent_names	->  Name.invent_list
  4441 
  4442 Note that low-level renaming rarely occurs in new code -- operations
  4443 from structure Variable are used instead (see below).
  4444 
  4445 * Pure: structure Variable provides fundamental operations for proper
  4446 treatment of fixed/schematic variables in a context.  For example,
  4447 Variable.import introduces fixes for schematics of given facts and
  4448 Variable.export reverses the effect (up to renaming) -- this replaces
  4449 various freeze_thaw operations.
  4450 
  4451 * Pure: structure Goal provides simple interfaces for
  4452 init/conclude/finish and tactical prove operations (replacing former
  4453 Tactic.prove).  Goal.prove is the canonical way to prove results
  4454 within a given context; Goal.prove_global is a degraded version for
  4455 theory level goals, including a global Drule.standard.  Note that
  4456 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4457 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4458 in a locale context).
  4459 
  4460 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4461 and type checking (Syntax.check_term etc.), with common combinations
  4462 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4463 which are considered legacy and await removal.
  4464 
  4465 * Pure/Syntax: generic interfaces for type unchecking
  4466 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4467 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4468 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4469 available for convenience, but refer to the very same operations using
  4470 a mere theory instead of a full context.
  4471 
  4472 * Isar: simplified treatment of user-level errors, using exception
  4473 ERROR of string uniformly.  Function error now merely raises ERROR,
  4474 without any side effect on output channels.  The Isar toplevel takes
  4475 care of proper display of ERROR exceptions.  ML code may use plain
  4476 handle/can/try; cat_error may be used to concatenate errors like this:
  4477 
  4478   ... handle ERROR msg => cat_error msg "..."
  4479 
  4480 Toplevel ML code (run directly or through the Isar toplevel) may be
  4481 embedded into the Isar toplevel with exception display/debug like
  4482 this:
  4483 
  4484   Isar.toplevel (fn () => ...)
  4485 
  4486 INCOMPATIBILITY, removed special transform_error facilities, removed
  4487 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4488 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4489 -- use plain ERROR instead.
  4490 
  4491 * Isar: theory setup now has type (theory -> theory), instead of a
  4492 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4493 
  4494 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4495 ProofContext.debug/verbose flags.
  4496 
  4497 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4498 theory before entering a proof state.  Transactions now always see a
  4499 quasi-functional intermediate checkpoint, both in interactive and
  4500 batch mode.
  4501 
  4502 * Isar: simplified interfaces for outer syntax.  Renamed
  4503 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4504 OuterSyntax.add_parsers -- this functionality is now included in
  4505 OuterSyntax.command etc.  INCOMPATIBILITY.
  4506 
  4507 * Simplifier: the simpset of a running simplification process now
  4508 contains a proof context (cf. Simplifier.the_context), which is the
  4509 very context that the initial simpset has been retrieved from (by
  4510 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4511 (solver, looper etc.) may depend on arbitrary proof data.
  4512 
  4513 * Simplifier.inherit_context inherits the proof context (plus the
  4514 local bounds) of the current simplification process; any simproc
  4515 etc. that calls the Simplifier recursively should do this!  Removed
  4516 former Simplifier.inherit_bounds, which is already included here --
  4517 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4518 specify an explicit context using Simplifier.context/theory_context.
  4519 
  4520 * Simplifier/Classical Reasoner: more abstract interfaces
  4521 change_simpset/claset for modifying the simpset/claset reference of a
  4522 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4523 INCOMPATIBILITY.
  4524 
  4525 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4526 "Trueprop" etc.
  4527 
  4528 
  4529 *** System ***
  4530 
  4531 * settings: the default heap location within ISABELLE_HOME_USER now
  4532 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4533 Isabelle installations.
  4534 
  4535 * isabelle-process: option -S (secure mode) disables some critical
  4536 operations, notably runtime compilation and evaluation of ML source
  4537 code.
  4538 
  4539 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4540 
  4541 * Support for parallel execution, using native multicore support of
  4542 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4543 independent theories, according to the given theory header
  4544 specifications. The maximum number of worker threads is specified via
  4545 usedir option -M or the "max-threads" setting in Proof General. A
  4546 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4547 to 6 on a 8-core machine.  User-code needs to observe certain
  4548 guidelines for thread-safe programming, see appendix A in the Isar
  4549 Implementation manual.
  4550 
  4551 
  4552 
  4553 New in Isabelle2005 (October 2005)
  4554 ----------------------------------
  4555 
  4556 *** General ***
  4557 
  4558 * Theory headers: the new header syntax for Isar theories is
  4559 
  4560   theory <name>
  4561   imports <theory1> ... <theoryN>
  4562   uses <file1> ... <fileM>
  4563   begin
  4564 
  4565 where the 'uses' part is optional.  The previous syntax
  4566 
  4567   theory <name> = <theory1> + ... + <theoryN>:
  4568 
  4569 will disappear in the next release.  Use isatool fixheaders to convert
  4570 existing theory files.  Note that there is no change in ancient
  4571 non-Isar theories now, but these will disappear soon.
  4572 
  4573 * Theory loader: parent theories can now also be referred to via
  4574 relative and absolute paths.
  4575 
  4576 * Command 'find_theorems' searches for a list of criteria instead of a
  4577 list of constants. Known criteria are: intro, elim, dest, name:string,
  4578 simp:term, and any term. Criteria can be preceded by '-' to select
  4579 theorems that do not match. Intro, elim, dest select theorems that
  4580 match the current goal, name:s selects theorems whose fully qualified
  4581 name contain s, and simp:term selects all simplification rules whose
  4582 lhs match term.  Any other term is interpreted as pattern and selects
  4583 all theorems matching the pattern. Available in ProofGeneral under
  4584 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4585 
  4586   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4587 
  4588 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4589 matching the current goal as introduction rule and not having "HOL."
  4590 in their name (i.e. not being defined in theory HOL).
  4591 
  4592 * Command 'thms_containing' has been discontinued in favour of
  4593 'find_theorems'; INCOMPATIBILITY.
  4594 
  4595 * Communication with Proof General is now 8bit clean, which means that
  4596 Unicode text in UTF-8 encoding may be used within theory texts (both
  4597 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4598 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4599 
  4600   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4601   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4602 
  4603 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4604 Classical Reasoner.  Typical big applications run around 2 times
  4605 faster.
  4606 
  4607 
  4608 *** Document preparation ***
  4609 
  4610 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4611 of raw sources.  Only those symbols that do not require additional
  4612 LaTeX packages (depending on comments in isabellesym.sty) are
  4613 displayed properly, everything else is left verbatim.  isatool display
  4614 and isatool print are used as front ends (these are subject to the
  4615 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4616 
  4617 * Command tags control specific markup of certain regions of text,
  4618 notably folding and hiding.  Predefined tags include "theory" (for
  4619 theory begin and end), "proof" for proof commands, and "ML" for
  4620 commands involving ML code; the additional tags "visible" and
  4621 "invisible" are unused by default.  Users may give explicit tag
  4622 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4623 interpretation of tags is determined by the LaTeX job during document
  4624 preparation: see option -V of isatool usedir, or options -n and -t of
  4625 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4626 \isadroptag.
  4627 
  4628 Several document versions may be produced at the same time via isatool
  4629 usedir (the generated index.html will link all of them).  Typical
  4630 specifications include ''-V document=theory,proof,ML'' to present
  4631 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4632 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4633 these parts without any formal replacement text.  The Isabelle site
  4634 default settings produce ''document'' and ''outline'' versions as
  4635 specified above.
  4636 
  4637 * Several new antiquotations:
  4638 
  4639   @{term_type term} prints a term with its type annotated;
  4640 
  4641   @{typeof term} prints the type of a term;
  4642 
  4643   @{const const} is the same as @{term const}, but checks that the
  4644   argument is a known logical constant;
  4645 
  4646   @{term_style style term} and @{thm_style style thm} print a term or
  4647   theorem applying a "style" to it
  4648 
  4649   @{ML text}
  4650 
  4651 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4652 definitions, equations, inequations etc., 'concl' printing only the
  4653 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4654 to print the specified premise.  TermStyle.add_style provides an ML
  4655 interface for introducing further styles.  See also the "LaTeX Sugar"
  4656 document practical applications.  The ML antiquotation prints
  4657 type-checked ML expressions verbatim.
  4658 
  4659 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4660 and 'text' support optional locale specification '(in loc)', which
  4661 specifies the default context for interpreting antiquotations.  For
  4662 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4663 
  4664 * Option 'locale=NAME' of antiquotations specifies an alternative
  4665 context interpreting the subsequent argument.  For example: @{thm
  4666 [locale=lattice] inf_assoc}.
  4667 
  4668 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4669 a proof context.
  4670 
  4671 * Proper output of antiquotations for theory commands involving a
  4672 proof context (such as 'locale' or 'theorem (in loc) ...').
  4673 
  4674 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4675 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4676 
  4677 * isatool usedir: new option -C (default true) controls whether option
  4678 -D should include a copy of the original document directory; -C false
  4679 prevents unwanted effects such as copying of administrative CVS data.
  4680 
  4681 
  4682 *** Pure ***
  4683 
  4684 * Considerably improved version of 'constdefs' command.  Now performs
  4685 automatic type-inference of declared constants; additional support for
  4686 local structure declarations (cf. locales and HOL records), see also
  4687 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4688 sequential dependencies of definitions within a single 'constdefs'
  4689 section; moreover, the declared name needs to be an identifier.  If
  4690 all fails, consider to fall back on 'consts' and 'defs' separately.
  4691 
  4692 * Improved indexed syntax and implicit structures.  First of all,
  4693 indexed syntax provides a notational device for subscripted
  4694 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4695 expressions.  Secondly, in a local context with structure
  4696 declarations, number indexes \<^sub>n or the empty index (default
  4697 number 1) refer to a certain fixed variable implicitly; option
  4698 show_structs controls printing of implicit structures.  Typical
  4699 applications of these concepts involve record types and locales.
  4700 
  4701 * New command 'no_syntax' removes grammar declarations (and
  4702 translations) resulting from the given syntax specification, which is
  4703 interpreted in the same manner as for the 'syntax' command.
  4704 
  4705 * 'Advanced' translation functions (parse_translation etc.) may depend
  4706 on the signature of the theory context being presently used for
  4707 parsing/printing, see also isar-ref manual.
  4708 
  4709 * Improved 'oracle' command provides a type-safe interface to turn an
  4710 ML expression of type theory -> T -> term into a primitive rule of
  4711 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4712 is already included here); see also FOL/ex/IffExample.thy;
  4713 INCOMPATIBILITY.
  4714 
  4715 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4716 before); "cI" is no longer bound, use "c.intro" instead.
  4717 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4718 axclasses vs. locales.
  4719 
  4720 * Improved internal renaming of symbolic identifiers -- attach primes
  4721 instead of base 26 numbers.
  4722 
  4723 * New flag show_question_marks controls printing of leading question
  4724 marks in schematic variable names.
  4725 
  4726 * In schematic variable names, *any* symbol following \<^isub> or
  4727 \<^isup> is now treated as part of the base name.  For example, the
  4728 following works without printing of awkward ".0" indexes:
  4729 
  4730   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4731     by simp
  4732 
  4733 * Inner syntax includes (*(*nested*) comments*).
  4734 
  4735 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4736 annotations as "(00...)".
  4737 
  4738 * Clear separation of logical types and nonterminals, where the latter
  4739 may only occur in 'syntax' specifications or type abbreviations.
  4740 Before that distinction was only partially implemented via type class
  4741 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4742 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4743 exotic syntax specifications may require further adaption
  4744 (e.g. Cube/Cube.thy).
  4745 
  4746 * Removed obsolete type class "logic", use the top sort {} instead.
  4747 Note that non-logical types should be declared as 'nonterminals'
  4748 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4749 specifications.
  4750 
  4751 * Attributes 'induct' and 'cases': type or set names may now be
  4752 locally fixed variables as well.
  4753 
  4754 * Simplifier: can now control the depth to which conditional rewriting
  4755 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4756 Limit.
  4757 
  4758 * Simplifier: simplification procedures may now take the current
  4759 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4760 interface), which is very useful for calling the Simplifier
  4761 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4762 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4763 low-level mk_simproc no longer applies Logic.varify internally, to
  4764 allow for use in a context of fixed variables.
  4765 
  4766 * thin_tac now works even if the assumption being deleted contains !!
  4767 or ==>.  More generally, erule now works even if the major premise of
  4768 the elimination rule contains !! or ==>.
  4769 
  4770 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4771 
  4772 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4773 from Pure, which contains all common declarations already.  Both
  4774 theories are defined via plain Isabelle/Isar .thy files.
  4775 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4776 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4777 use isatool fixcpure to adapt your theory and ML sources.
  4778 
  4779 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4780 selections of theorems in named facts via index ranges.
  4781 
  4782 * 'print_theorems': in theory mode, really print the difference
  4783 wrt. the last state (works for interactive theory development only),
  4784 in proof mode print all local facts (cf. 'print_facts');
  4785 
  4786 * 'hide': option '(open)' hides only base names.
  4787 
  4788 * More efficient treatment of intermediate checkpoints in interactive
  4789 theory development.
  4790 
  4791 * Code generator is now invoked via code_module (incremental code
  4792 generation) and code_library (modular code generation, ML structures
  4793 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4794 must be quoted when used as identifiers.
  4795 
  4796 * New 'value' command for reading, evaluating and printing terms using
  4797 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4798 quoted when used as identifier.
  4799 
  4800 
  4801 *** Locales ***
  4802 
  4803 * New commands for the interpretation of locale expressions in
  4804 theories (1), locales (2) and proof contexts (3).  These generate
  4805 proof obligations from the expression specification.  After the
  4806 obligations have been discharged, theorems of the expression are added
  4807 to the theory, target locale or proof context.  The synopsis of the
  4808 commands is a follows:
  4809 
  4810   (1) interpretation expr inst
  4811   (2) interpretation target < expr
  4812   (3) interpret expr inst
  4813 
  4814 Interpretation in theories and proof contexts require a parameter
  4815 instantiation of terms from the current context.  This is applied to
  4816 specifications and theorems of the interpreted expression.
  4817 Interpretation in locales only permits parameter renaming through the
  4818 locale expression.  Interpretation is smart in that interpretations
  4819 that are active already do not occur in proof obligations, neither are
  4820 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4821 inspect active interpretations of a particular locale.  For details,
  4822 see the Isar Reference manual.  Examples can be found in
  4823 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4824 
  4825 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4826 'interpret' instead.
  4827 
  4828 * New context element 'constrains' for adding type constraints to
  4829 parameters.
  4830 
  4831 * Context expressions: renaming of parameters with syntax
  4832 redeclaration.
  4833 
  4834 * Locale declaration: 'includes' disallowed.
  4835 
  4836 * Proper static binding of attribute syntax -- i.e. types / terms /
  4837 facts mentioned as arguments are always those of the locale definition
  4838 context, independently of the context of later invocations.  Moreover,
  4839 locale operations (renaming and type / term instantiation) are applied
  4840 to attribute arguments as expected.
  4841 
  4842 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4843 actual attributes; rare situations may require Attrib.attribute to
  4844 embed those attributes into Attrib.src that lack concrete syntax.
  4845 Attribute implementations need to cooperate properly with the static
  4846 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4847 Attrib.XXX_thm etc. already do the right thing without further
  4848 intervention.  Only unusual applications -- such as "where" or "of"
  4849 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4850 on the context and the facts involved -- may have to assign parsed
  4851 values to argument tokens explicitly.
  4852 
  4853 * Changed parameter management in theorem generation for long goal
  4854 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4855 theorem statement in rare situations.
  4856 
  4857 * Locale inspection command 'print_locale' omits notes elements.  Use
  4858 'print_locale!' to have them included in the output.
  4859 
  4860 
  4861 *** Provers ***
  4862 
  4863 * Provers/hypsubst.ML: improved version of the subst method, for
  4864 single-step rewriting: it now works in bound variable contexts. New is
  4865 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4866 rewrite a different subterm than the original subst method, which is
  4867 still available as 'simplesubst'.
  4868 
  4869 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4870 and quasi orders.
  4871 
  4872 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4873 reflexive-transitive closure of relations.
  4874 
  4875 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4876 limit (previously hard-coded with a value of 20) user-definable.
  4877 
  4878 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4879 is peformed already.  Object-logics merely need to finish their
  4880 initial simpset configuration as before.  INCOMPATIBILITY.
  4881 
  4882 
  4883 *** HOL ***
  4884 
  4885 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4886 
  4887   syntax (epsilon)
  4888     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4889 
  4890 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4891 and x-symbol; use option '-m epsilon' to get it actually printed.
  4892 Moreover, the mathematically important symbolic identifier \<epsilon>
  4893 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4894 
  4895 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4896 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4897 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4898 support corresponding Isar calculations.
  4899 
  4900 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4901 instead of ":".
  4902 
  4903 * theory SetInterval: changed the syntax for open intervals:
  4904 
  4905   Old       New
  4906   {..n(}    {..<n}
  4907   {)n..}    {n<..}
  4908   {m..n(}   {m..<n}
  4909   {)m..n}   {m<..n}
  4910   {)m..n(}  {m<..<n}
  4911 
  4912 The old syntax is still supported but will disappear in the next
  4913 release.  For conversion use the following Emacs search and replace
  4914 patterns (these are not perfect but work quite well):
  4915 
  4916   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4917   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4918 
  4919 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4920 equalities in commutative rings; method 'algebra' provides a generic
  4921 interface.
  4922 
  4923 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4924 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4925 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4926 be a tuple pattern.
  4927 
  4928 Some new syntax forms are available:
  4929 
  4930   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4931   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4932   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4933   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4934 
  4935 The latter form "\<Sum>x < k. e" used to be based on a separate
  4936 function "Summation", which has been discontinued.
  4937 
  4938 * theory Finite_Set: in structured induction proofs, the insert case
  4939 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4940 (insert F x)'.
  4941 
  4942 * The 'refute' command has been extended to support a much larger
  4943 fragment of HOL, including axiomatic type classes, constdefs and
  4944 typedefs, inductive datatypes and recursion.
  4945 
  4946 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4947 Requires zChaff with proof generation to be installed.  See
  4948 HOL/ex/SAT_Examples.thy for examples.
  4949 
  4950 * Datatype induction via method 'induct' now preserves the name of the
  4951 induction variable. For example, when proving P(xs::'a list) by
  4952 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4953 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4954 in unstructured proof scripts.
  4955 
  4956 * Reworked implementation of records.  Improved scalability for
  4957 records with many fields, avoiding performance problems for type
  4958 inference. Records are no longer composed of nested field types, but
  4959 of nested extension types. Therefore the record type only grows linear
  4960 in the number of extensions and not in the number of fields.  The
  4961 top-level (users) view on records is preserved.  Potential
  4962 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4963 old record representation. The type generated for a record is called
  4964 <record_name>_ext_type.
  4965 
  4966 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4967 proofs triggered by a record definition or a simproc (if
  4968 quick_and_dirty is enabled).  Definitions of large records can take
  4969 quite long.
  4970 
  4971 New simproc record_upd_simproc for simplification of multiple record
  4972 updates enabled by default.  Moreover, trivial updates are also
  4973 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4974 occasionally, since simplification is more powerful by default.
  4975 
  4976 * typedef: proper support for polymorphic sets, which contain extra
  4977 type-variables in the term.
  4978 
  4979 * Simplifier: automatically reasons about transitivity chains
  4980 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4981 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4982 old proofs break occasionally as simplification may now solve more
  4983 goals than previously.
  4984 
  4985 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4986 present.  Works for all partial orders (class "order"), in particular
  4987 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4988 just like y <= x.
  4989 
  4990 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4991 bound variable or a constant then the let is unfolded.  Otherwise
  4992 first a is simplified to b, and then f b is simplified to g. If
  4993 possible we abstract b from g arriving at "let x = b in h x",
  4994 otherwise we unfold the let and arrive at g.  The simproc can be
  4995 enabled/disabled by the reference use_let_simproc.  Potential
  4996 INCOMPATIBILITY since simplification is more powerful by default.
  4997 
  4998 * Classical reasoning: the meson method now accepts theorems as arguments.
  4999 
  5000 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5001 jobs to provide advice on the provability of subgoals.
  5002 
  5003 * Theory OrderedGroup and Ring_and_Field: various additions and
  5004 improvements to faciliate calculations involving equalities and
  5005 inequalities.
  5006 
  5007 The following theorems have been eliminated or modified
  5008 (INCOMPATIBILITY):
  5009 
  5010   abs_eq             now named abs_of_nonneg
  5011   abs_of_ge_0        now named abs_of_nonneg
  5012   abs_minus_eq       now named abs_of_nonpos
  5013   imp_abs_id         now named abs_of_nonneg
  5014   imp_abs_neg_id     now named abs_of_nonpos
  5015   mult_pos           now named mult_pos_pos
  5016   mult_pos_le        now named mult_nonneg_nonneg
  5017   mult_pos_neg_le    now named mult_nonneg_nonpos
  5018   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5019   mult_neg           now named mult_neg_neg
  5020   mult_neg_le        now named mult_nonpos_nonpos
  5021 
  5022 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5023      
  5024      zero_le_square
  5025      not_square_less_zero 
  5026 
  5027   The following lemmas have been deleted from Real/RealPow:
  5028   
  5029      realpow_zero_zero
  5030      realpow_two
  5031      realpow_less
  5032      zero_le_power
  5033      realpow_two_le
  5034      abs_realpow_two
  5035      realpow_two_abs     
  5036 
  5037 * Theory Parity: added rules for simplifying exponents.
  5038 
  5039 * Theory List:
  5040 
  5041 The following theorems have been eliminated or modified
  5042 (INCOMPATIBILITY):
  5043 
  5044   list_all_Nil       now named list_all.simps(1)
  5045   list_all_Cons      now named list_all.simps(2)
  5046   list_all_conv      now named list_all_iff
  5047   set_mem_eq         now named mem_iff
  5048 
  5049 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5050 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5051 
  5052 
  5053 *** HOL-Complex ***
  5054 
  5055 * Theory RealDef: better support for embedding natural numbers and
  5056 integers in the reals.
  5057 
  5058 The following theorems have been eliminated or modified
  5059 (INCOMPATIBILITY):
  5060 
  5061   exp_ge_add_one_self  now requires no hypotheses
  5062   real_of_int_add      reversed direction of equality (use [symmetric])
  5063   real_of_int_minus    reversed direction of equality (use [symmetric])
  5064   real_of_int_diff     reversed direction of equality (use [symmetric])
  5065   real_of_int_mult     reversed direction of equality (use [symmetric])
  5066 
  5067 * Theory RComplete: expanded support for floor and ceiling functions.
  5068 
  5069 * Theory Ln is new, with properties of the natural logarithm
  5070 
  5071 * Hyperreal: There is a new type constructor "star" for making
  5072 nonstandard types.  The old type names are now type synonyms:
  5073 
  5074   hypreal = real star
  5075   hypnat = nat star
  5076   hcomplex = complex star
  5077 
  5078 * Hyperreal: Many groups of similarly-defined constants have been
  5079 replaced by polymorphic versions (INCOMPATIBILITY):
  5080 
  5081   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5082 
  5083   starset      <-- starsetNat, starsetC
  5084   *s*          <-- *sNat*, *sc*
  5085   starset_n    <-- starsetNat_n, starsetC_n
  5086   *sn*         <-- *sNatn*, *scn*
  5087   InternalSets <-- InternalNatSets, InternalCSets
  5088 
  5089   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5090   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5091   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5092   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5093   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5094 
  5095 * Hyperreal: Many type-specific theorems have been removed in favor of
  5096 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5097 
  5098   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5099   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5100   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5101   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5102   right_minus <-- hypreal_add_minus
  5103   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5104   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5105   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5106   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5107   mult_1_right <-- hcomplex_mult_one_right
  5108   mult_zero_left <-- hcomplex_mult_zero_left
  5109   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5110   right_distrib <-- hypnat_add_mult_distrib2
  5111   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5112   right_inverse <-- hypreal_mult_inverse
  5113   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5114   order_refl <-- {hypreal,hypnat}_le_refl
  5115   order_trans <-- {hypreal,hypnat}_le_trans
  5116   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5117   order_less_le <-- {hypreal,hypnat}_less_le
  5118   linorder_linear <-- {hypreal,hypnat}_le_linear
  5119   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5120   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5121   add_nonneg_nonneg <-- hypreal_le_add_order
  5122 
  5123 * Hyperreal: Separate theorems having to do with type-specific
  5124 versions of constants have been merged into theorems that apply to the
  5125 new polymorphic constants (INCOMPATIBILITY):
  5126 
  5127   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5128   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5129   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5130   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5131   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5132   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5133   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5134   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5135   STAR_diff <-- {STAR,STARC}_diff
  5136   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5137     STARC_hcomplex_of_complex}_image_subset
  5138   starset_n_Un <-- starset{Nat,C}_n_Un
  5139   starset_n_Int <-- starset{Nat,C}_n_Int
  5140   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5141   starset_n_diff <-- starset{Nat,C}_n_diff
  5142   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5143   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5144   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5145   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5146   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5147   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5148   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5149   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5150   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5151   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5152   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5153   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5154   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5155   starfun_diff <-- starfun{C,RC,CR}_diff
  5156   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5157   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5158   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5159   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5160   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5161   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5162   starfun_Id <-- starfunC_Id
  5163   starfun_approx <-- starfun{Nat,CR}_approx
  5164   starfun_capprox <-- starfun{C,RC}_capprox
  5165   starfun_abs <-- starfunNat_rabs
  5166   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5167   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5168   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5169   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5170   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5171   starfun_add_approx <-- starfunCR_add_approx
  5172   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5173   starfun_divide <-- starfun{C,CR,RC}_divide
  5174   starfun_n <-- starfun{Nat,C}_n
  5175   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5176   starfun_n_add <-- starfun{Nat,C}_n_add
  5177   starfun_n_add_minus <-- starfunNat_n_add_minus
  5178   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5179   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5180   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5181 
  5182   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5183   star_n_minus <-- {hypreal,hcomplex}_minus
  5184   star_n_diff <-- {hypreal,hcomplex}_diff
  5185   star_n_mult <-- {hypreal,hcomplex}_mult
  5186   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5187   star_n_le <-- {hypreal,hypnat}_le
  5188   star_n_less <-- {hypreal,hypnat}_less
  5189   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5190   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5191   star_n_abs <-- hypreal_hrabs
  5192   star_n_divide <-- hcomplex_divide
  5193 
  5194   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5195   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5196   star_of_diff <-- hypreal_of_real_diff
  5197   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5198   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5199   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5200   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5201   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5202   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5203   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5204   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5205   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5206   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5207   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5208   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5209   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5210   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5211   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5212   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5213   star_of_power <-- hypreal_of_real_power
  5214   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5215 
  5216 * Hyperreal: new method "transfer" that implements the transfer
  5217 principle of nonstandard analysis. With a subgoal that mentions
  5218 nonstandard types like "'a star", the command "apply transfer"
  5219 replaces it with an equivalent one that mentions only standard types.
  5220 To be successful, all free variables must have standard types; non-
  5221 standard variables must have explicit universal quantifiers.
  5222 
  5223 * Hyperreal: A theory of Taylor series.
  5224 
  5225 
  5226 *** HOLCF ***
  5227 
  5228 * Discontinued special version of 'constdefs' (which used to support
  5229 continuous functions) in favor of the general Pure one with full
  5230 type-inference.
  5231 
  5232 * New simplification procedure for solving continuity conditions; it
  5233 is much faster on terms with many nested lambda abstractions (cubic
  5234 instead of exponential time).
  5235 
  5236 * New syntax for domain package: selector names are now optional.
  5237 Parentheses should be omitted unless argument is lazy, for example:
  5238 
  5239   domain 'a stream = cons "'a" (lazy "'a stream")
  5240 
  5241 * New command 'fixrec' for defining recursive functions with pattern
  5242 matching; defining multiple functions with mutual recursion is also
  5243 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5244 sinr, or any data constructor defined by the domain package. The given
  5245 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5246 syntax and examples.
  5247 
  5248 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5249 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5250 but the proof obligation additionally includes an admissibility
  5251 requirement. The packages generate instances of class cpo or pcpo,
  5252 with continuity and strictness theorems for Rep and Abs.
  5253 
  5254 * HOLCF: Many theorems have been renamed according to a more standard naming
  5255 scheme (INCOMPATIBILITY):
  5256 
  5257   foo_inject:  "foo$x = foo$y ==> x = y"
  5258   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5259   foo_less:    "(foo$x << foo$y) = (x << y)"
  5260   foo_strict:  "foo$UU = UU"
  5261   foo_defined: "... ==> foo$x ~= UU"
  5262   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5263 
  5264 
  5265 *** ZF ***
  5266 
  5267 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5268 including the First Isomorphism Theorem (on quotienting by the kernel
  5269 of a homomorphism).
  5270 
  5271 * ZF/Simplifier: install second copy of type solver that actually
  5272 makes use of TC rules declared to Isar proof contexts (or locales);
  5273 the old version is still required for ML proof scripts.
  5274 
  5275 
  5276 *** Cube ***
  5277 
  5278 * Converted to Isar theory format; use locales instead of axiomatic
  5279 theories.
  5280 
  5281 
  5282 *** ML ***
  5283 
  5284 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5285 for ||>, ||>>, |>>,
  5286 
  5287 * Pure/library.ML no longer defines its own option datatype, but uses
  5288 that of the SML basis, which has constructors NONE and SOME instead of
  5289 None and Some, as well as exception Option.Option instead of OPTION.
  5290 The functions the, if_none, is_some, is_none have been adapted
  5291 accordingly, while Option.map replaces apsome.
  5292 
  5293 * Pure/library.ML: the exception LIST has been given up in favour of
  5294 the standard exceptions Empty and Subscript, as well as
  5295 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5296 superceded by the standard hd and tl functions etc.
  5297 
  5298 A number of basic list functions are no longer exported to the ML
  5299 toplevel, as they are variants of predefined functions.  The following
  5300 suggests how one can translate existing code:
  5301 
  5302     rev_append xs ys = List.revAppend (xs, ys)
  5303     nth_elem (i, xs) = List.nth (xs, i)
  5304     last_elem xs = List.last xs
  5305     flat xss = List.concat xss
  5306     seq fs = List.app fs
  5307     partition P xs = List.partition P xs
  5308     mapfilter f xs = List.mapPartial f xs
  5309 
  5310 * Pure/library.ML: several combinators for linear functional
  5311 transformations, notably reverse application and composition:
  5312 
  5313   x |> f                f #> g
  5314   (x, y) |-> f          f #-> g
  5315 
  5316 * Pure/library.ML: introduced/changed precedence of infix operators:
  5317 
  5318   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5319   infix 2 ?;
  5320   infix 3 o oo ooo oooo;
  5321   infix 4 ~~ upto downto;
  5322 
  5323 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5324 infix operators.
  5325 
  5326 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5327 fold_map support linear functional transformations and nesting.  For
  5328 example:
  5329 
  5330   fold f [x1, ..., xN] y =
  5331     y |> f x1 |> ... |> f xN
  5332 
  5333   (fold o fold) f [xs1, ..., xsN] y =
  5334     y |> fold f xs1 |> ... |> fold f xsN
  5335 
  5336   fold f [x1, ..., xN] =
  5337     f x1 #> ... #> f xN
  5338 
  5339   (fold o fold) f [xs1, ..., xsN] =
  5340     fold f xs1 #> ... #> fold f xsN
  5341 
  5342 * Pure/library.ML: the following selectors on type 'a option are
  5343 available:
  5344 
  5345   the:               'a option -> 'a  (*partial*)
  5346   these:             'a option -> 'a  where 'a = 'b list
  5347   the_default: 'a -> 'a option -> 'a
  5348   the_list:          'a option -> 'a list
  5349 
  5350 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5351 basic operations for association lists, following natural argument
  5352 order; moreover the explicit equality predicate passed here avoids
  5353 potentially expensive polymorphic runtime equality checks.
  5354 The old functions may be expressed as follows:
  5355 
  5356   assoc = uncurry (AList.lookup (op =))
  5357   assocs = these oo AList.lookup (op =)
  5358   overwrite = uncurry (AList.update (op =)) o swap
  5359 
  5360 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5361 
  5362   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5363   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5364 
  5365 replacing make_keylist and keyfilter (occassionally used)
  5366 Naive rewrites:
  5367 
  5368   make_keylist = AList.make
  5369   keyfilter = AList.find (op =)
  5370 
  5371 * eq_fst and eq_snd now take explicit equality parameter, thus
  5372   avoiding eqtypes. Naive rewrites:
  5373 
  5374     eq_fst = eq_fst (op =)
  5375     eq_snd = eq_snd (op =)
  5376 
  5377 * Removed deprecated apl and apr (rarely used).
  5378   Naive rewrites:
  5379 
  5380     apl (n, op) =>>= curry op n
  5381     apr (op, m) =>>= fn n => op (n, m)
  5382 
  5383 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5384 provides a reasonably efficient light-weight implementation of sets as
  5385 lists.
  5386 
  5387 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5388 few new operations; existing lookup and update are now curried to
  5389 follow natural argument order (for use with fold etc.);
  5390 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5391 
  5392 * Pure/General: output via the Isabelle channels of
  5393 writeln/warning/error etc. is now passed through Output.output, with a
  5394 hook for arbitrary transformations depending on the print_mode
  5395 (cf. Output.add_mode -- the first active mode that provides a output
  5396 function wins).  Already formatted output may be embedded into further
  5397 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5398 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5399 accommodate easy composition of diagnostic messages etc.  Programmers
  5400 rarely need to care about Output.output or Output.raw at all, with
  5401 some notable exceptions: Output.output is required when bypassing the
  5402 standard channels (writeln etc.), or in token translations to produce
  5403 properly formatted results; Output.raw is required when capturing
  5404 already output material that will eventually be presented to the user
  5405 a second time.  For the default print mode, both Output.output and
  5406 Output.raw have no effect.
  5407 
  5408 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5409 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5410 cumulative results are displayed at the end of a batch session.
  5411 
  5412 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5413 replaced by File.platform_path and File.shell_path (with appropriate
  5414 hooks).  This provides a clean interface for unusual systems where the
  5415 internal and external process view of file names are different.
  5416 
  5417 * Pure: more efficient orders for basic syntactic entities: added
  5418 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5419 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5420 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5421 orders now -- potential INCOMPATIBILITY for code that depends on a
  5422 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5423 Library.sort_strings on result).
  5424 
  5425 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5426 fold_types traverse types/terms from left to right, observing natural
  5427 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5428 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5429 
  5430 * Pure: name spaces have been refined, with significant changes of the
  5431 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5432 to extern(_table).  The plain name entry path is superceded by a
  5433 general 'naming' context, which also includes the 'policy' to produce
  5434 a fully qualified name and external accesses of a fully qualified
  5435 name; NameSpace.extend is superceded by context dependent
  5436 Sign.declare_name.  Several theory and proof context operations modify
  5437 the naming context.  Especially note Theory.restore_naming and
  5438 ProofContext.restore_naming to get back to a sane state; note that
  5439 Theory.add_path is no longer sufficient to recover from
  5440 Theory.absolute_path in particular.
  5441 
  5442 * Pure: new flags short_names (default false) and unique_names
  5443 (default true) for controlling output of qualified names.  If
  5444 short_names is set, names are printed unqualified.  If unique_names is
  5445 reset, the name prefix is reduced to the minimum required to achieve
  5446 the original result when interning again, even if there is an overlap
  5447 with earlier declarations.
  5448 
  5449 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5450 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5451 (useful for printing error messages).  INCOMPATIBILITY.
  5452 
  5453 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5454 Theory.theory are now identified, referring to the universal
  5455 Context.theory (see Pure/context.ML).  Actual signature and theory
  5456 content is managed as theory data.  The old code and interfaces were
  5457 spread over many files and structures; the new arrangement introduces
  5458 considerable INCOMPATIBILITY to gain more clarity:
  5459 
  5460   Context -- theory management operations (name, identity, inclusion,
  5461     parents, ancestors, merge, etc.), plus generic theory data;
  5462 
  5463   Sign -- logical signature and syntax operations (declaring consts,
  5464     types, etc.), plus certify/read for common entities;
  5465 
  5466   Theory -- logical theory operations (stating axioms, definitions,
  5467     oracles), plus a copy of logical signature operations (consts,
  5468     types, etc.); also a few basic management operations (Theory.copy,
  5469     Theory.merge, etc.)
  5470 
  5471 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5472 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5473 for convenience -- they merely return the theory.
  5474 
  5475 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5476 
  5477 * Pure: the Isar proof context type is already defined early in Pure
  5478 as Context.proof (note that ProofContext.context and Proof.context are
  5479 aliases, where the latter is the preferred name).  This enables other
  5480 Isabelle components to refer to that type even before Isar is present.
  5481 
  5482 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5483 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5484 any of these kinds.  For example, Sign.intern typeK is now
  5485 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5486 Theory.hide_types.  Also note that former
  5487 Theory.hide_classes/types/consts are now
  5488 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5489 internalize their arguments!  INCOMPATIBILITY.
  5490 
  5491 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5492 datatype thmref (with constructors Name and NameSelection) instead of
  5493 plain string -- INCOMPATIBILITY;
  5494 
  5495 * Pure: cases produced by proof methods specify options, where NONE
  5496 means to remove case bindings -- INCOMPATIBILITY in
  5497 (RAW_)METHOD_CASES.
  5498 
  5499 * Pure: the following operations retrieve axioms or theorems from a
  5500 theory node or theory hierarchy, respectively:
  5501 
  5502   Theory.axioms_of: theory -> (string * term) list
  5503   Theory.all_axioms_of: theory -> (string * term) list
  5504   PureThy.thms_of: theory -> (string * thm) list
  5505   PureThy.all_thms_of: theory -> (string * thm) list
  5506 
  5507 * Pure: print_tac now outputs the goal through the trace channel.
  5508 
  5509 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5510 Reference Toplevel.debug (default false) controls detailed printing
  5511 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5512 controls execution profiling -- set to 1 for time and 2 for space
  5513 (both increase the runtime).
  5514 
  5515 * Isar session: The initial use of ROOT.ML is now always timed,
  5516 i.e. the log will show the actual process times, in contrast to the
  5517 elapsed wall-clock time that the outer shell wrapper produces.
  5518 
  5519 * Simplifier: improved handling of bound variables (nameless
  5520 representation, avoid allocating new strings).  Simprocs that invoke
  5521 the Simplifier recursively should use Simplifier.inherit_bounds to
  5522 avoid local name clashes.  Failure to do so produces warnings
  5523 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5524 for further details.
  5525 
  5526 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5527 bindings for all theorems stored within a given theory; this may help
  5528 in porting non-Isar theories to Isar ones, while keeping ML proof
  5529 scripts for the time being.
  5530 
  5531 * ML operator HTML.with_charset specifies the charset begin used for
  5532 generated HTML files.  For example:
  5533 
  5534   HTML.with_charset "utf-8" use_thy "Hebrew";
  5535   HTML.with_charset "utf-8" use_thy "Chinese";
  5536 
  5537 
  5538 *** System ***
  5539 
  5540 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5541 isabelle, isatool etc.).
  5542 
  5543 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5544 isatool doc, isatool mkdir, display_drafts etc.).
  5545 
  5546 * isatool usedir: option -f allows specification of the ML file to be
  5547 used by Isabelle; default is ROOT.ML.
  5548 
  5549 * New isatool version outputs the version identifier of the Isabelle
  5550 distribution being used.
  5551 
  5552 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5553 (containing Boolean satisfiability problems) into Isabelle/HOL
  5554 theories.
  5555 
  5556 
  5557 
  5558 New in Isabelle2004 (April 2004)
  5559 --------------------------------
  5560 
  5561 *** General ***
  5562 
  5563 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5564   Replaces linorder.ML.
  5565 
  5566 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5567   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5568   (\<a>...\<z>), are now considered normal letters, and can therefore
  5569   be used anywhere where an ASCII letter (a...zA...Z) has until
  5570   now. COMPATIBILITY: This obviously changes the parsing of some
  5571   terms, especially where a symbol has been used as a binder, say
  5572   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5573   as an identifier.  Fix it by inserting a space around former
  5574   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5575   existing theory and ML files.
  5576 
  5577 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5578 
  5579 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5580   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5581   a normal (but invisible) letter. For multiple letter subscripts repeat
  5582   \<^isub> like this: x\<^isub>1\<^isub>2.
  5583 
  5584 * Pure: There are now sub-/superscripts that can span more than one
  5585   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5586   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5587   superscript. The new control characters are not identifier parts.
  5588 
  5589 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5590   content of "..." to the latex file instead of \isacntrl... . The "..."
  5591   may consist of any printable characters excluding the end bracket >.
  5592 
  5593 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5594   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5595   declare constants "final", which prevents their being given a definition
  5596   later.  It is useful for constants whose behaviour is fixed axiomatically
  5597   rather than definitionally, such as the meta-logic connectives.
  5598 
  5599 * Pure: 'instance' now handles general arities with general sorts
  5600   (i.e. intersections of classes),
  5601 
  5602 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5603   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5604   It can be changed to alter the colors/layout of generated pages.
  5605 
  5606 
  5607 *** Isar ***
  5608 
  5609 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5610   cut_tac, subgoal_tac and thin_tac:
  5611   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5612     locales are no longer forced to write Isar proof scripts.
  5613     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5614     emulations.
  5615   - INCOMPATIBILITY: names of variables to be instantiated may no
  5616     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5617     This is consistent with the instantiation attribute "where".
  5618 
  5619 * Attributes "where" and "of":
  5620   - Now take type variables of instantiated theorem into account when reading
  5621     the instantiation string.  This fixes a bug that caused instantiated
  5622     theorems to have too special types in some circumstances.
  5623   - "where" permits explicit instantiations of type variables.
  5624 
  5625 * Calculation commands "moreover" and "also" no longer interfere with
  5626   current facts ("this"), admitting arbitrary combinations with "then"
  5627   and derived forms.
  5628 
  5629 * Locales:
  5630   - Goal statements involving the context element "includes" no longer
  5631     generate theorems with internal delta predicates (those ending on
  5632     "_axioms") in the premise.
  5633     Resolve particular premise with <locale>.intro to obtain old form.
  5634   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5635     specification and "includes" elements in goal statement.
  5636   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5637     [intro?] and [elim?] (respectively) by default.
  5638   - Experimental command for instantiation of locales in proof contexts:
  5639         instantiate <label>[<attrs>]: <loc>
  5640     Instantiates locale <loc> and adds all its theorems to the current context
  5641     taking into account their attributes.  Label and attrs are optional
  5642     modifiers, like in theorem declarations.  If present, names of
  5643     instantiated theorems are qualified with <label>, and the attributes
  5644     <attrs> are applied after any attributes these theorems might have already.
  5645       If the locale has assumptions, a chained fact of the form
  5646     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5647     are derived.  The command does not support old-style locales declared
  5648     with "locale (open)".
  5649       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5650 
  5651 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5652   (Isar) contexts.
  5653 
  5654 
  5655 *** HOL ***
  5656 
  5657 * Proof import: new image HOL4 contains the imported library from
  5658   the HOL4 system with about 2500 theorems. It is imported by
  5659   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5660   can be used like any other Isabelle image.  See
  5661   HOL/Import/HOL/README for more information.
  5662 
  5663 * Simplifier:
  5664   - Much improved handling of linear and partial orders.
  5665     Reasoners for linear and partial orders are set up for type classes
  5666     "linorder" and "order" respectively, and are added to the default simpset
  5667     as solvers.  This means that the simplifier can build transitivity chains
  5668     to solve goals from the assumptions.
  5669   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5670     of blast or auto after simplification become unnecessary because the goal
  5671     is solved by simplification already.
  5672 
  5673 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5674     all proved in axiomatic type classes for semirings, rings and fields.
  5675 
  5676 * Numerics:
  5677   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5678     now formalized using the Ring_and_Field theory mentioned above.
  5679   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5680     than before, because now they are set up once in a generic manner.
  5681   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5682     Look for the general versions in Ring_and_Field (and Power if they concern
  5683     exponentiation).
  5684 
  5685 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5686 
  5687 * Records:
  5688   - Record types are now by default printed with their type abbreviation
  5689     instead of the list of all field types. This can be configured via
  5690     the reference "print_record_type_abbr".
  5691   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5692     (not enabled by default).
  5693   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5694     EX x. x = sel r to True (not enabled by default).
  5695   - Tactic "record_split_simp_tac" to split and simplify records added.
  5696 
  5697 * 'specification' command added, allowing for definition by
  5698   specification.  There is also an 'ax_specification' command that
  5699   introduces the new constants axiomatically.
  5700 
  5701 * arith(_tac) is now able to generate counterexamples for reals as well.
  5702 
  5703 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5704 
  5705 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5706   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5707 
  5708 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5709   matrix theory to linear programming.
  5710 
  5711 * Unions and Intersections:
  5712   The latex output syntax of UN and INT has been changed
  5713   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5714   i.e. the index formulae has become a subscript.
  5715   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5716 
  5717 * Unions and Intersections over Intervals:
  5718   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5719   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5720   like in normal math, and corresponding versions for < and for intersection.
  5721 
  5722 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5723   lexicographic dictonary ordering has been added as "lexord".
  5724 
  5725 * ML: the legacy theory structures Int and List have been removed. They had
  5726   conflicted with ML Basis Library structures having the same names.
  5727 
  5728 * 'refute' command added to search for (finite) countermodels.  Only works
  5729   for a fragment of HOL.  The installation of an external SAT solver is
  5730   highly recommended.  See "HOL/Refute.thy" for details.
  5731 
  5732 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5733   formulae under an assignment of free variables to random values.
  5734   In contrast to 'refute', it can deal with inductive datatypes,
  5735   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5736   for examples.
  5737 
  5738 
  5739 *** HOLCF ***
  5740 
  5741 * Streams now come with concatenation and are part of the HOLCF image
  5742 
  5743 
  5744 
  5745 New in Isabelle2003 (May 2003)
  5746 ------------------------------
  5747 
  5748 *** General ***
  5749 
  5750 * Provers/simplifier:
  5751 
  5752   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5753     Assumptions are now subject to complete mutual simplification,
  5754     not just from left to right. The simplifier now preserves
  5755     the order of assumptions.
  5756 
  5757     Potential INCOMPATIBILITY:
  5758 
  5759     -- simp sometimes diverges where the old version did
  5760        not, e.g. invoking simp on the goal
  5761 
  5762         [| P (f x); y = x; f x = f y |] ==> Q
  5763 
  5764        now gives rise to the infinite reduction sequence
  5765 
  5766         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5767 
  5768        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5769        kind of problem.
  5770 
  5771     -- Tactics combining classical reasoner and simplification (such as auto)
  5772        are also affected by this change, because many of them rely on
  5773        simp. They may sometimes diverge as well or yield a different numbers
  5774        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5775        in case of problems. Sometimes subsequent calls to the classical
  5776        reasoner will fail because a preceeding call to the simplifier too
  5777        eagerly simplified the goal, e.g. deleted redundant premises.
  5778 
  5779   - The simplifier trace now shows the names of the applied rewrite rules
  5780 
  5781   - You can limit the number of recursive invocations of the simplifier
  5782     during conditional rewriting (where the simplifie tries to solve the
  5783     conditions before applying the rewrite rule):
  5784     ML "simp_depth_limit := n"
  5785     where n is an integer. Thus you can force termination where previously
  5786     the simplifier would diverge.
  5787 
  5788   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5789 
  5790   - No longer aborts on failed congruence proof.  Instead, the
  5791     congruence is ignored.
  5792 
  5793 * Pure: New generic framework for extracting programs from constructive
  5794   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5795   as HOL/Extraction for some case studies.
  5796 
  5797 * Pure: The main goal of the proof state is no longer shown by default, only
  5798 the subgoals. This behaviour is controlled by a new flag.
  5799    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5800 (ML: Proof.show_main_goal).
  5801 
  5802 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5803 rules whose conclusion matches subgoal 1:
  5804       PG menu: Isabelle/Isar -> Show me -> matching rules
  5805 The rules are ordered by how closely they match the subgoal.
  5806 In particular, rules that solve a subgoal outright are displayed first
  5807 (or rather last, the way they are printed).
  5808 (ML: ProofGeneral.print_intros())
  5809 
  5810 * Pure: New flag trace_unify_fail causes unification to print
  5811 diagnostic information (PG: in trace buffer) when it fails. This is
  5812 useful for figuring out why single step proofs like rule, erule or
  5813 assumption failed.
  5814 
  5815 * Pure: Locale specifications now produce predicate definitions
  5816 according to the body of text (covering assumptions modulo local
  5817 definitions); predicate "loc_axioms" covers newly introduced text,
  5818 while "loc" is cumulative wrt. all included locale expressions; the
  5819 latter view is presented only on export into the global theory
  5820 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5821 on the old view without predicates;
  5822 
  5823 * Pure: predefined locales "var" and "struct" are useful for sharing
  5824 parameters (as in CASL, for example); just specify something like
  5825 ``var x + var y + struct M'' as import;
  5826 
  5827 * Pure: improved thms_containing: proper indexing of facts instead of
  5828 raw theorems; check validity of results wrt. current name space;
  5829 include local facts of proof configuration (also covers active
  5830 locales), cover fixed variables in index; may use "_" in term
  5831 specification; an optional limit for the number of printed facts may
  5832 be given (the default is 40);
  5833 
  5834 * Pure: disallow duplicate fact bindings within new-style theory files
  5835 (batch-mode only);
  5836 
  5837 * Provers: improved induct method: assumptions introduced by case
  5838 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5839 the goal statement); "foo" still refers to all facts collectively;
  5840 
  5841 * Provers: the function blast.overloaded has been removed: all constants
  5842 are regarded as potentially overloaded, which improves robustness in exchange
  5843 for slight decrease in efficiency;
  5844 
  5845 * Provers/linorder: New generic prover for transitivity reasoning over
  5846 linear orders.  Note: this prover is not efficient!
  5847 
  5848 * Isar: preview of problems to finish 'show' now produce an error
  5849 rather than just a warning (in interactive mode);
  5850 
  5851 
  5852 *** HOL ***
  5853 
  5854 * arith(_tac)
  5855 
  5856  - Produces a counter example if it cannot prove a goal.
  5857    Note that the counter example may be spurious if the goal is not a formula
  5858    of quantifier-free linear arithmetic.
  5859    In ProofGeneral the counter example appears in the trace buffer.
  5860 
  5861  - Knows about div k and mod k where k is a numeral of type nat or int.
  5862 
  5863  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5864    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5865    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5866 
  5867 * simp's arithmetic capabilities have been enhanced a bit: it now
  5868 takes ~= in premises into account (by performing a case split);
  5869 
  5870 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5871 are distributed over a sum of terms;
  5872 
  5873 * New tactic "trans_tac" and method "trans" instantiate
  5874 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5875 "<=", "<" and "=").
  5876 
  5877 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5878 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5879 
  5880 * 'typedef' command has new option "open" to suppress the set
  5881 definition;
  5882 
  5883 * functions Min and Max on finite sets have been introduced (theory
  5884 Finite_Set);
  5885 
  5886 * attribute [symmetric] now works for relations as well; it turns
  5887 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5888 
  5889 * induct over a !!-quantified statement (say !!x1..xn):
  5890   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5891 
  5892 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5893 %x. None. Warning: empty_def now refers to the previously hidden definition
  5894 of the empty set.
  5895 
  5896 * Algebra: formalization of classical algebra.  Intended as base for
  5897 any algebraic development in Isabelle.  Currently covers group theory
  5898 (up to Sylow's theorem) and ring theory (Universal Property of
  5899 Univariate Polynomials).  Contributions welcome;
  5900 
  5901 * GroupTheory: deleted, since its material has been moved to Algebra;
  5902 
  5903 * Complex: new directory of the complex numbers with numeric constants,
  5904 nonstandard complex numbers, and some complex analysis, standard and
  5905 nonstandard (Jacques Fleuriot);
  5906 
  5907 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5908 
  5909 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5910 Fleuriot);
  5911 
  5912 * Real/HahnBanach: updated and adapted to locales;
  5913 
  5914 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5915 Gray and Kramer);
  5916 
  5917 * UNITY: added the Meier-Sanders theory of progress sets;
  5918 
  5919 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5920 as abstract algorithms, instantiated to the JVM;
  5921 
  5922 * Bali: Java source language formalization. Type system, operational
  5923 semantics, axiomatic semantics. Supported language features:
  5924 classes, interfaces, objects,virtual methods, static methods,
  5925 static/instance fields, arrays, access modifiers, definite
  5926 assignment, exceptions.
  5927 
  5928 
  5929 *** ZF ***
  5930 
  5931 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5932 universe, etc.);
  5933 
  5934 * Main ZF: virtually all theories converted to new-style format;
  5935 
  5936 
  5937 *** ML ***
  5938 
  5939 * Pure: Tactic.prove provides sane interface for internal proofs;
  5940 omits the infamous "standard" operation, so this is more appropriate
  5941 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5942 
  5943 * Pure: improved error reporting of simprocs;
  5944 
  5945 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5946 up simprocs;
  5947 
  5948 
  5949 *** Document preparation ***
  5950 
  5951 * uses \par instead of \\ for line breaks in theory text. This may
  5952 shift some page breaks in large documents. To get the old behaviour
  5953 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5954 
  5955 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5956 other packages
  5957 
  5958 * \<euro> now needs package babel/greek instead of marvosym (which
  5959 broke \Rightarrow)
  5960 
  5961 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5962 textcomp package)
  5963 
  5964 
  5965 
  5966 New in Isabelle2002 (March 2002)
  5967 --------------------------------
  5968 
  5969 *** Document preparation ***
  5970 
  5971 * greatly simplified document preparation setup, including more
  5972 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5973 instructive isatool mkdir; users should basically be able to get
  5974 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5975 users may run a separate document processing stage manually like this:
  5976 "isatool usedir -D output HOL Test && isatool document Test/output";
  5977 
  5978 * theory dependency graph may now be incorporated into documents;
  5979 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5980 with \includegraphics of LaTeX;
  5981 
  5982 * proper spacing of consecutive markup elements, especially text
  5983 blocks after section headings;
  5984 
  5985 * support bold style (for single symbols only), input syntax is like
  5986 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5987 
  5988 * \<bullet> is now output as bold \cdot by default, which looks much
  5989 better in printed text;
  5990 
  5991 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5992 note that these symbols are currently unavailable in Proof General /
  5993 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5994 
  5995 * isatool latex no longer depends on changed TEXINPUTS, instead
  5996 isatool document copies the Isabelle style files to the target
  5997 location;
  5998 
  5999 
  6000 *** Isar ***
  6001 
  6002 * Pure/Provers: improved proof by cases and induction;
  6003   - 'case' command admits impromptu naming of parameters (such as
  6004     "case (Suc n)");
  6005   - 'induct' method divinates rule instantiation from the inductive
  6006     claim; no longer requires excessive ?P bindings for proper
  6007     instantiation of cases;
  6008   - 'induct' method properly enumerates all possibilities of set/type
  6009     rules; as a consequence facts may be also passed through *type*
  6010     rules without further ado;
  6011   - 'induct' method now derives symbolic cases from the *rulified*
  6012     rule (before it used to rulify cases stemming from the internal
  6013     atomized version); this means that the context of a non-atomic
  6014     statement becomes is included in the hypothesis, avoiding the
  6015     slightly cumbersome show "PROP ?case" form;
  6016   - 'induct' may now use elim-style induction rules without chaining
  6017     facts, using ``missing'' premises from the goal state; this allows
  6018     rules stemming from inductive sets to be applied in unstructured
  6019     scripts, while still benefitting from proper handling of non-atomic
  6020     statements; NB: major inductive premises need to be put first, all
  6021     the rest of the goal is passed through the induction;
  6022   - 'induct' proper support for mutual induction involving non-atomic
  6023     rule statements (uses the new concept of simultaneous goals, see
  6024     below);
  6025   - append all possible rule selections, but only use the first
  6026     success (no backtracking);
  6027   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6028   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6029   - added 'print_induct_rules' (covered by help item in recent Proof
  6030     General versions);
  6031   - moved induct/cases attributes to Pure, methods to Provers;
  6032   - generic method setup instantiated for FOL and HOL;
  6033 
  6034 * Pure: support multiple simultaneous goal statements, for example
  6035 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6036 meta-level mechanism, this acts as if several individual goals had
  6037 been stated separately; in particular common proof methods need to be
  6038 repeated in order to cover all claims; note that a single elimination
  6039 step is *not* sufficient to establish the two conjunctions, so this
  6040 fails:
  6041 
  6042   assume "A & B" then have A and B ..   (*".." fails*)
  6043 
  6044 better use "obtain" in situations as above; alternative refer to
  6045 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6046 
  6047 * Pure: proper integration with ``locales''; unlike the original
  6048 version by Florian Kammller, Isar locales package high-level proof
  6049 contexts rather than raw logical ones (e.g. we admit to include
  6050 attributes everywhere); operations on locales include merge and
  6051 rename; support for implicit arguments (``structures''); simultaneous
  6052 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6053 some examples;
  6054 
  6055 * Pure: the following commands have been ``localized'', supporting a
  6056 target locale specification "(in name)": 'lemma', 'theorem',
  6057 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6058 stored both within the locale and at the theory level (exported and
  6059 qualified by the locale name);
  6060 
  6061 * Pure: theory goals may now be specified in ``long'' form, with
  6062 ad-hoc contexts consisting of arbitrary locale elements. for example
  6063 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6064 definitions may be given, too); the result is a meta-level rule with
  6065 the context elements being discharged in the obvious way;
  6066 
  6067 * Pure: new proof command 'using' allows to augment currently used
  6068 facts after a goal statement ('using' is syntactically analogous to
  6069 'apply', but acts on the goal's facts only); this allows chained facts
  6070 to be separated into parts given before and after a claim, as in
  6071 ``from a and b have C using d and e <proof>'';
  6072 
  6073 * Pure: renamed "antecedent" case to "rule_context";
  6074 
  6075 * Pure: new 'judgment' command records explicit information about the
  6076 object-logic embedding (used by several tools internally); no longer
  6077 use hard-wired "Trueprop";
  6078 
  6079 * Pure: added 'corollary' command;
  6080 
  6081 * Pure: fixed 'token_translation' command;
  6082 
  6083 * Pure: removed obsolete 'exported' attribute;
  6084 
  6085 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6086 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6087 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6088 
  6089 * Pure: method 'atomize' presents local goal premises as object-level
  6090 statements (atomic meta-level propositions); setup controlled via
  6091 rewrite rules declarations of 'atomize' attribute; example
  6092 application: 'induct' method with proper rule statements in improper
  6093 proof *scripts*;
  6094 
  6095 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6096 now consider the syntactic context of assumptions, giving a better
  6097 chance to get type-inference of the arguments right (this is
  6098 especially important for locales);
  6099 
  6100 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6101 mode;
  6102 
  6103 * Pure/obtain: the formal conclusion "thesis", being marked as
  6104 ``internal'', may no longer be reference directly in the text;
  6105 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6106 situations;
  6107 
  6108 * Pure: generic 'sym' attribute which declares a rule both as pure
  6109 'elim?' and for the 'symmetric' operation;
  6110 
  6111 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6112 text; the fixed correlation with particular command syntax has been
  6113 discontinued;
  6114 
  6115 * Pure: new method 'rules' is particularly well-suited for proof
  6116 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6117 but often produces more compact proof terms with less detours;
  6118 
  6119 * Pure/Provers/classical: simplified integration with pure rule
  6120 attributes and methods; the classical "intro?/elim?/dest?"
  6121 declarations coincide with the pure ones; the "rule" method no longer
  6122 includes classically swapped intros; "intro" and "elim" methods no
  6123 longer pick rules from the context; also got rid of ML declarations
  6124 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6125 INCOMPATIBILITY;
  6126 
  6127 * Provers/classical: attribute 'swapped' produces classical inversions
  6128 of introduction rules;
  6129 
  6130 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6131 rules instead of full simplifier context; 'iff' attribute handles
  6132 conditional rules;
  6133 
  6134 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6135 
  6136 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6137 "(permissive)" option to recover old behavior;
  6138 
  6139 * HOL: 'inductive' no longer features separate (collective) attributes
  6140 for 'intros' (was found too confusing);
  6141 
  6142 * HOL: properly declared induction rules less_induct and
  6143 wf_induct_rule;
  6144 
  6145 
  6146 *** HOL ***
  6147 
  6148 * HOL: moved over to sane numeral syntax; the new policy is as
  6149 follows:
  6150 
  6151   - 0 and 1 are polymorphic constants, which are defined on any
  6152   numeric type (nat, int, real etc.);
  6153 
  6154   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6155   binary representation internally;
  6156 
  6157   - type nat has special constructor Suc, and generally prefers Suc 0
  6158   over 1::nat and Suc (Suc 0) over 2::nat;
  6159 
  6160 This change may cause significant problems of INCOMPATIBILITY; here
  6161 are some hints on converting existing sources:
  6162 
  6163   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6164   entities, so expressions involving "-" (unary or binary minus) need
  6165   to be spaced properly;
  6166 
  6167   - existing occurrences of "1" may need to be constraint "1::nat" or
  6168   even replaced by Suc 0; similar for old "2";
  6169 
  6170   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6171 
  6172   - remove all special provisions on numerals in proofs;
  6173 
  6174 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6175 representation (depends on bin_arith_simps in the default context);
  6176 
  6177 * HOL: symbolic syntax for x^2 (numeral 2);
  6178 
  6179 * HOL: the class of all HOL types is now called "type" rather than
  6180 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6181 in axclass/classes, instance/arities, and (usually rare) occurrences
  6182 in typings (of consts etc.); internally the class is called
  6183 "HOL.type", ML programs should refer to HOLogic.typeS;
  6184 
  6185 * HOL/record package improvements:
  6186   - new derived operations "fields" to build a partial record section,
  6187     "extend" to promote a fixed record to a record scheme, and
  6188     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6189     declared as simp by default;
  6190   - shared operations ("more", "fields", etc.) now need to be always
  6191     qualified) --- potential INCOMPATIBILITY;
  6192   - removed "make_scheme" operations (use "make" with "extend") --
  6193     INCOMPATIBILITY;
  6194   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6195   - provides cases/induct rules for use with corresponding Isar
  6196     methods (for concrete records, record schemes, concrete more
  6197     parts, and schematic more parts -- in that order);
  6198   - internal definitions directly based on a light-weight abstract
  6199     theory of product types over typedef rather than datatype;
  6200 
  6201 * HOL: generic code generator for generating executable ML code from
  6202 specifications; specific support for HOL constructs such as inductive
  6203 datatypes and sets, as well as recursive functions; can be invoked
  6204 via 'generate_code' theory section;
  6205 
  6206 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6207 
  6208 * HOL: consolidated and renamed several theories.  In particular:
  6209         Ord.thy has been absorbed into HOL.thy
  6210         String.thy has been absorbed into List.thy
  6211 
  6212 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6213 (beware of argument permutation!);
  6214 
  6215 * HOL: linorder_less_split superseded by linorder_cases;
  6216 
  6217 * HOL/List: "nodups" renamed to "distinct";
  6218 
  6219 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6220 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6221   - Ex_def has changed, now need to use some_eq_ex
  6222 
  6223 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6224 in this (rare) case use:
  6225 
  6226   delSWrapper "split_all_tac"
  6227   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6228 
  6229 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6230 MAY FAIL;