NEWS
author blanchet
Thu May 12 15:29:19 2011 +0200 (2011-05-12)
changeset 42740 31334a7b109d
parent 42724 4d6bcf846759
child 42793 88bee9f6eec7
permissions -rw-r--r--
renamed "max_mono_instances" to "max_new_mono_instances" and changed its semantics accordingly
     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: former unsynchronized references are now proper
    41 configuration options, with more conventional names:
    42 
    43   long_names   ~> names_long
    44   short_names  ~> names_short
    45   unique_names ~> names_unique
    46 
    47 Minor INCOMPATIBILITY, need to declare options in context like this:
    48 
    49   declare [[names_unique = false]]
    50 
    51 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    52 that the result needs to be unique, which means fact specifications
    53 may have to be refined after enriching a proof context.
    54 
    55 * Isabelle/Isar reference manual provides more formal references in
    56 syntax diagrams.
    57 
    58 
    59 *** HOL ***
    60 
    61 * Nitpick:
    62   - Added "need" and "total_consts" options.
    63   - Reintroduced "show_skolems" option by popular demand.
    64   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    65     INCOMPATIBILITY.
    66 
    67 * Sledgehammer:
    68   - sledgehammer available_provers ~> sledgehammer supported_provers
    69     INCOMPATIBILITY.
    70   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    71     TPTP problems (TFF).
    72   - Added "type_sys", "max_mono_iters", and "max_new_mono_instances" options.
    73 
    74 * "try":
    75   - Added "simp:", "intro:", and "elim:" options.
    76 
    77 * Quickcheck:
    78   - Added "eval" option to evaluate terms for the found counterexample
    79     (currently only supported by the default (exhaustive) tester)
    80   - Added post-processing of terms to obtain readable counterexamples
    81     (currently only supported by the default (exhaustive) tester)
    82 
    83 * Function package: discontinued option "tailrec".
    84 INCOMPATIBILITY. Use partial_function instead.
    85 
    86 * HOL-Probability:
    87   - Caratheodory's extension lemma is now proved for ring_of_sets.
    88   - Infinite products of probability measures are now available.
    89   - Use extended reals instead of positive extended reals.
    90     INCOMPATIBILITY.
    91 
    92 
    93 *** Document preparation ***
    94 
    95 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
    96 isar-ref manual.
    97 
    98 * Localized \isabellestyle switch can be used within blocks or groups
    99 like this:
   100 
   101   \isabellestyle{it}  %preferred default
   102   {\isabellestylett @{text "typewriter stuff"}}
   103 
   104 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   105 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   106 
   107 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   108 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   109 
   110 
   111 *** ML ***
   112 
   113 * Structure Proof_Context follows standard naming scheme.  Old
   114 ProofContext is still available for some time as legacy alias.
   115 
   116 * Structure Timing provides various operations for timing; supersedes
   117 former start_timing/end_timing etc.
   118 
   119 * Path.print is the official way to show file-system paths to users
   120 (including quotes etc.).
   121 
   122 * Inner syntax: identifiers in parse trees of generic categories
   123 "logic", "aprop", "idt" etc. carry position information (disguised as
   124 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   125 translations that choke on unexpected type constraints.  Positions can
   126 be stripped in ML translations via Syntax.strip_positions /
   127 Syntax.strip_positions_ast, or via the syntax constant
   128 "_strip_positions" within parse trees.  As last resort, positions can
   129 be disabled via the configuration option Syntax.positions, which is
   130 called "syntax_positions" in Isar attribute syntax.
   131 
   132 * Discontinued special status of various ML structures that contribute
   133 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   134 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   135 refer directly to Ast.Constant, Lexicon.is_identifier,
   136 Syntax_Trans.mk_binder_tr etc.
   137 
   138 * Typed print translation: discontinued show_sorts argument, which is
   139 already available via context of "advanced" translation.
   140 
   141 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   142 goal states; body tactic needs to address all subgoals uniformly.
   143 
   144 * Slightly more special eq_list/eq_set, with shortcut involving
   145 pointer equality (assumes that eq relation is reflexive).
   146 
   147 
   148 
   149 New in Isabelle2011 (January 2011)
   150 ----------------------------------
   151 
   152 *** General ***
   153 
   154 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   155 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   156 useful tooltips and hyperlinks produced from its static analysis.  The
   157 bundled component provides an executable Isabelle tool that can be run
   158 like this:
   159 
   160   Isabelle2011/bin/isabelle jedit
   161 
   162 * Significantly improved Isabelle/Isar implementation manual.
   163 
   164 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   165 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   166 while the default heap location within that directory lacks that extra
   167 suffix.  This isolates multiple Isabelle installations from each
   168 other, avoiding problems with old settings in new versions.
   169 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   170 
   171 * Source files are always encoded as UTF-8, instead of old-fashioned
   172 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   173 the following package declarations:
   174 
   175   \usepackage[utf8]{inputenc}
   176   \usepackage{textcomp}
   177 
   178 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   179 a Unicode character is treated as a single symbol, not a sequence of
   180 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   181 contain symbols without further backslash escapes, Unicode can now be
   182 used here as well.  Recall that Symbol.explode in ML provides a
   183 consistent view on symbols, while raw explode (or String.explode)
   184 merely give a byte-oriented representation.
   185 
   186 * Theory loader: source files are primarily located via the master
   187 directory of each theory node (where the .thy file itself resides).
   188 The global load path is still partially available as legacy feature.
   189 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   190 explicit paths, relatively to the theory.
   191 
   192 * Special treatment of ML file names has been discontinued.
   193 Historically, optional extensions .ML or .sml were added on demand --
   194 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   195 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   196 
   197 * Various options that affect pretty printing etc. are now properly
   198 handled within the context via configuration options, instead of
   199 unsynchronized references or print modes.  There are both ML Config.T
   200 entities and Isar declaration attributes to access these.
   201 
   202   ML (Config.T)                 Isar (attribute)
   203 
   204   eta_contract                  eta_contract
   205   show_brackets                 show_brackets
   206   show_sorts                    show_sorts
   207   show_types                    show_types
   208   show_question_marks           show_question_marks
   209   show_consts                   show_consts
   210   show_abbrevs                  show_abbrevs
   211 
   212   Syntax.ast_trace              syntax_ast_trace
   213   Syntax.ast_stat               syntax_ast_stat
   214   Syntax.ambiguity_level        syntax_ambiguity_level
   215 
   216   Goal_Display.goals_limit      goals_limit
   217   Goal_Display.show_main_goal   show_main_goal
   218 
   219   Method.rule_trace             rule_trace
   220 
   221   Thy_Output.display            thy_output_display
   222   Thy_Output.quotes             thy_output_quotes
   223   Thy_Output.indent             thy_output_indent
   224   Thy_Output.source             thy_output_source
   225   Thy_Output.break              thy_output_break
   226 
   227 Note that corresponding "..._default" references in ML may only be
   228 changed globally at the ROOT session setup, but *not* within a theory.
   229 The option "show_abbrevs" supersedes the former print mode
   230 "no_abbrevs" with inverted meaning.
   231 
   232 * More systematic naming of some configuration options.
   233 INCOMPATIBILITY.
   234 
   235   trace_simp  ~>  simp_trace
   236   debug_simp  ~>  simp_debug
   237 
   238 * Support for real valued configuration options, using simplistic
   239 floating-point notation that coincides with the inner syntax for
   240 float_token.
   241 
   242 * Support for real valued preferences (with approximative PGIP type):
   243 front-ends need to accept "pgint" values in float notation.
   244 INCOMPATIBILITY.
   245 
   246 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   247 DejaVu Sans.
   248 
   249 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   250 
   251 
   252 *** Pure ***
   253 
   254 * Command 'type_synonym' (with single argument) replaces somewhat
   255 outdated 'types', which is still available as legacy feature for some
   256 time.
   257 
   258 * Command 'nonterminal' (with 'and' separated list of arguments)
   259 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   260 
   261 * Command 'notepad' replaces former 'example_proof' for
   262 experimentation in Isar without any result.  INCOMPATIBILITY.
   263 
   264 * Locale interpretation commands 'interpret' and 'sublocale' accept
   265 lists of equations to map definitions in a locale to appropriate
   266 entities in the context of the interpretation.  The 'interpretation'
   267 command already provided this functionality.
   268 
   269 * Diagnostic command 'print_dependencies' prints the locale instances
   270 that would be activated if the specified expression was interpreted in
   271 the current context.  Variant "print_dependencies!" assumes a context
   272 without interpretations.
   273 
   274 * Diagnostic command 'print_interps' prints interpretations in proofs
   275 in addition to interpretations in theories.
   276 
   277 * Discontinued obsolete 'global' and 'local' commands to manipulate
   278 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   279 Sign.root_path and Sign.local_path may be applied directly where this
   280 feature is still required for historical reasons.
   281 
   282 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   283 'definition' instead.
   284 
   285 * The "prems" fact, which refers to the accidental collection of
   286 foundational premises in the context, is now explicitly marked as
   287 legacy feature and will be discontinued soon.  Consider using "assms"
   288 of the head statement or reference facts by explicit names.
   289 
   290 * Document antiquotations @{class} and @{type} print classes and type
   291 constructors.
   292 
   293 * Document antiquotation @{file} checks file/directory entries within
   294 the local file system.
   295 
   296 
   297 *** HOL ***
   298 
   299 * Coercive subtyping: functions can be declared as coercions and type
   300 inference will add them as necessary upon input of a term.  Theory
   301 Complex_Main declares real :: nat => real and real :: int => real as
   302 coercions. A coercion function f is declared like this:
   303 
   304   declare [[coercion f]]
   305 
   306 To lift coercions through type constructors (e.g. from nat => real to
   307 nat list => real list), map functions can be declared, e.g.
   308 
   309   declare [[coercion_map map]]
   310 
   311 Currently coercion inference is activated only in theories including
   312 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   313 the configuration option "coercion_enabled", e.g. it can be enabled in
   314 other theories like this:
   315 
   316   declare [[coercion_enabled]]
   317 
   318 * Command 'partial_function' provides basic support for recursive
   319 function definitions over complete partial orders.  Concrete instances
   320 are provided for i) the option type, ii) tail recursion on arbitrary
   321 types, and iii) the heap monad of Imperative_HOL.  See
   322 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   323 for examples.
   324 
   325 * Function package: f.psimps rules are no longer implicitly declared
   326 as [simp].  INCOMPATIBILITY.
   327 
   328 * Datatype package: theorems generated for executable equality (class
   329 "eq") carry proper names and are treated as default code equations.
   330 
   331 * Inductive package: now offers command 'inductive_simps' to
   332 automatically derive instantiated and simplified equations for
   333 inductive predicates, similar to 'inductive_cases'.
   334 
   335 * Command 'enriched_type' allows to register properties of the
   336 functorial structure of types.
   337 
   338 * Improved infrastructure for term evaluation using code generator
   339 techniques, in particular static evaluation conversions.
   340 
   341 * Code generator: Scala (2.8 or higher) has been added to the target
   342 languages.
   343 
   344 * Code generator: globbing constant expressions "*" and "Theory.*"
   345 have been replaced by the more idiomatic "_" and "Theory._".
   346 INCOMPATIBILITY.
   347 
   348 * Code generator: export_code without explicit file declaration prints
   349 to standard output.  INCOMPATIBILITY.
   350 
   351 * Code generator: do not print function definitions for case
   352 combinators any longer.
   353 
   354 * Code generator: simplification with rules determined with
   355 src/Tools/Code/code_simp.ML and method "code_simp".
   356 
   357 * Code generator for records: more idiomatic representation of record
   358 types.  Warning: records are not covered by ancient SML code
   359 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   360 rep_datatype declaration helps to succeed then:
   361 
   362   record 'a foo = ...
   363   ...
   364   rep_datatype foo_ext ...
   365 
   366 * Records: logical foundation type for records does not carry a
   367 '_type' suffix any longer (obsolete due to authentic syntax).
   368 INCOMPATIBILITY.
   369 
   370 * Quickcheck now by default uses exhaustive testing instead of random
   371 testing.  Random testing can be invoked by "quickcheck [random]",
   372 exhaustive testing by "quickcheck [exhaustive]".
   373 
   374 * Quickcheck instantiates polymorphic types with small finite
   375 datatypes by default. This enables a simple execution mechanism to
   376 handle quantifiers and function equality over the finite datatypes.
   377 
   378 * Quickcheck random generator has been renamed from "code" to
   379 "random".  INCOMPATIBILITY.
   380 
   381 * Quickcheck now has a configurable time limit which is set to 30
   382 seconds by default. This can be changed by adding [timeout = n] to the
   383 quickcheck command. The time limit for Auto Quickcheck is still set
   384 independently.
   385 
   386 * Quickcheck in locales considers interpretations of that locale for
   387 counter example search.
   388 
   389 * Sledgehammer:
   390   - Added "smt" and "remote_smt" provers based on the "smt" proof
   391     method. See the Sledgehammer manual for details ("isabelle doc
   392     sledgehammer").
   393   - Renamed commands:
   394     sledgehammer atp_info ~> sledgehammer running_provers
   395     sledgehammer atp_kill ~> sledgehammer kill_provers
   396     sledgehammer available_atps ~> sledgehammer available_provers
   397     INCOMPATIBILITY.
   398   - Renamed options:
   399     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   400     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   401     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   402     (and "ms" and "min" are no longer supported)
   403     INCOMPATIBILITY.
   404 
   405 * Nitpick:
   406   - Renamed options:
   407     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   408     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   409     INCOMPATIBILITY.
   410   - Added support for partial quotient types.
   411   - Added local versions of the "Nitpick.register_xxx" functions.
   412   - Added "whack" option.
   413   - Allow registration of quotient types as codatatypes.
   414   - Improved "merge_type_vars" option to merge more types.
   415   - Removed unsound "fast_descrs" option.
   416   - Added custom symmetry breaking for datatypes, making it possible to reach
   417     higher cardinalities.
   418   - Prevent the expansion of too large definitions.
   419 
   420 * Proof methods "metis" and "meson" now have configuration options
   421 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   422 to diagnose these tools. E.g.
   423 
   424     using [[metis_trace = true]]
   425 
   426 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   427 manually as command 'solve_direct'.
   428 
   429 * The default SMT solver Z3 must be enabled explicitly (due to
   430 licensing issues) by setting the environment variable
   431 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   432 commercial applications, the SMT solver CVC3 is provided as fall-back;
   433 changing the SMT solver is done via the configuration option
   434 "smt_solver".
   435 
   436 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   437 i.e. "remote_cvc3" and "remote_z3".
   438 
   439 * Added basic SMT support for datatypes, records, and typedefs using
   440 the oracle mode (no proofs).  Direct support of pairs has been dropped
   441 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   442 support for a similar behavior).  Minor INCOMPATIBILITY.
   443 
   444 * Changed SMT configuration options:
   445   - Renamed:
   446     z3_proofs ~> smt_oracle (with inverted meaning)
   447     z3_trace_assms ~> smt_trace_used_facts
   448     INCOMPATIBILITY.
   449   - Added:
   450     smt_verbose
   451     smt_random_seed
   452     smt_datatypes
   453     smt_infer_triggers
   454     smt_monomorph_limit
   455     cvc3_options
   456     remote_cvc3_options
   457     remote_z3_options
   458     yices_options
   459 
   460 * Boogie output files (.b2i files) need to be declared in the theory
   461 header.
   462 
   463 * Simplification procedure "list_to_set_comprehension" rewrites list
   464 comprehensions applied to List.set to set comprehensions.  Occasional
   465 INCOMPATIBILITY, may be deactivated like this:
   466 
   467   declare [[simproc del: list_to_set_comprehension]]
   468 
   469 * Removed old version of primrec package.  INCOMPATIBILITY.
   470 
   471 * Removed simplifier congruence rule of "prod_case", as has for long
   472 been the case with "split".  INCOMPATIBILITY.
   473 
   474 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   475 
   476 * Removed [split_format ... and ... and ...] version of
   477 [split_format].  Potential INCOMPATIBILITY.
   478 
   479 * Predicate "sorted" now defined inductively, with nice induction
   480 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   481 
   482 * Constant "contents" renamed to "the_elem", to free the generic name
   483 contents for other uses.  INCOMPATIBILITY.
   484 
   485 * Renamed class eq and constant eq (for code generation) to class
   486 equal and constant equal, plus renaming of related facts and various
   487 tuning.  INCOMPATIBILITY.
   488 
   489 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   490 
   491 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   492 INCOMPATIBILITY.
   493 
   494 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   495 avoid confusion with finite sets.  INCOMPATIBILITY.
   496 
   497 * Abandoned locales equiv, congruent and congruent2 for equivalence
   498 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   499 for congruent(2)).
   500 
   501 * Some previously unqualified names have been qualified:
   502 
   503   types
   504     bool ~> HOL.bool
   505     nat ~> Nat.nat
   506 
   507   constants
   508     Trueprop ~> HOL.Trueprop
   509     True ~> HOL.True
   510     False ~> HOL.False
   511     op & ~> HOL.conj
   512     op | ~> HOL.disj
   513     op --> ~> HOL.implies
   514     op = ~> HOL.eq
   515     Not ~> HOL.Not
   516     The ~> HOL.The
   517     All ~> HOL.All
   518     Ex ~> HOL.Ex
   519     Ex1 ~> HOL.Ex1
   520     Let ~> HOL.Let
   521     If ~> HOL.If
   522     Ball ~> Set.Ball
   523     Bex ~> Set.Bex
   524     Suc ~> Nat.Suc
   525     Pair ~> Product_Type.Pair
   526     fst ~> Product_Type.fst
   527     snd ~> Product_Type.snd
   528     curry ~> Product_Type.curry
   529     op : ~> Set.member
   530     Collect ~> Set.Collect
   531 
   532 INCOMPATIBILITY.
   533 
   534 * More canonical naming convention for some fundamental definitions:
   535 
   536     bot_bool_eq ~> bot_bool_def
   537     top_bool_eq ~> top_bool_def
   538     inf_bool_eq ~> inf_bool_def
   539     sup_bool_eq ~> sup_bool_def
   540     bot_fun_eq  ~> bot_fun_def
   541     top_fun_eq  ~> top_fun_def
   542     inf_fun_eq  ~> inf_fun_def
   543     sup_fun_eq  ~> sup_fun_def
   544 
   545 INCOMPATIBILITY.
   546 
   547 * More stylized fact names:
   548 
   549   expand_fun_eq ~> fun_eq_iff
   550   expand_set_eq ~> set_eq_iff
   551   set_ext       ~> set_eqI
   552   nat_number    ~> eval_nat_numeral
   553 
   554 INCOMPATIBILITY.
   555 
   556 * Refactoring of code-generation specific operations in theory List:
   557 
   558   constants
   559     null ~> List.null
   560 
   561   facts
   562     mem_iff ~> member_def
   563     null_empty ~> null_def
   564 
   565 INCOMPATIBILITY.  Note that these were not supposed to be used
   566 regularly unless for striking reasons; their main purpose was code
   567 generation.
   568 
   569 Various operations from the Haskell prelude are used for generating
   570 Haskell code.
   571 
   572 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   573 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   574 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   575 
   576 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   577 "*" and "+" respectively.  INCOMPATIBILITY.
   578 
   579 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   580 "Sum_Type.Plus" instead.
   581 
   582 * Constant "split" has been merged with constant "prod_case"; names of
   583 ML functions, facts etc. involving split have been retained so far,
   584 though.  INCOMPATIBILITY.
   585 
   586 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   587 instead.  INCOMPATIBILITY.
   588 
   589 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   590 INCOMPATIBILITY.
   591 
   592 * Former theory Library/Enum is now part of the HOL-Main image.
   593 INCOMPATIBILITY: all constants of the Enum theory now have to be
   594 referred to by its qualified name.
   595 
   596   enum    ~>  Enum.enum
   597   nlists  ~>  Enum.nlists
   598   product ~>  Enum.product
   599 
   600 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   601 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   602 INCOMPATIBILITY.
   603 
   604 * Theory Library/SetsAndFunctions has been split into
   605 Library/Function_Algebras and Library/Set_Algebras; canonical names
   606 for instance definitions for functions; various improvements.
   607 INCOMPATIBILITY.
   608 
   609 * Theory Library/Multiset provides stable quicksort implementation of
   610 sort_key.
   611 
   612 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   613 INCOMPATIBILITY.
   614 
   615 * Session Multivariate_Analysis: introduced a type class for euclidean
   616 space.  Most theorems are now stated in terms of euclidean spaces
   617 instead of finite cartesian products.
   618 
   619   types
   620     real ^ 'n ~>  'a::real_vector
   621               ~>  'a::euclidean_space
   622               ~>  'a::ordered_euclidean_space
   623         (depends on your needs)
   624 
   625   constants
   626      _ $ _        ~> _ $$ _
   627      \<chi> x. _  ~> \<chi>\<chi> x. _
   628      CARD('n)     ~> DIM('a)
   629 
   630 Also note that the indices are now natural numbers and not from some
   631 finite type. Finite cartesian products of euclidean spaces, products
   632 of euclidean spaces the real and complex numbers are instantiated to
   633 be euclidean_spaces.  INCOMPATIBILITY.
   634 
   635 * Session Probability: introduced pextreal as positive extended real
   636 numbers.  Use pextreal as value for measures.  Introduce the
   637 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   638 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   639 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   640 
   641 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   642 INCOMPATIBILITY.
   643 
   644 * Session SPARK (with image HOL-SPARK) provides commands to load and
   645 prove verification conditions generated by the SPARK Ada program
   646 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   647 
   648 
   649 *** HOL-Algebra ***
   650 
   651 * Theorems for additive ring operations (locale abelian_monoid and
   652 descendants) are generated by interpretation from their multiplicative
   653 counterparts.  Names (in particular theorem names) have the mandatory
   654 qualifier 'add'.  Previous theorem names are redeclared for
   655 compatibility.
   656 
   657 * Structure "int_ring" is now an abbreviation (previously a
   658 definition).  This fits more natural with advanced interpretations.
   659 
   660 
   661 *** HOLCF ***
   662 
   663 * The domain package now runs in definitional mode by default: The
   664 former command 'new_domain' is now called 'domain'.  To use the domain
   665 package in its original axiomatic mode, use 'domain (unsafe)'.
   666 INCOMPATIBILITY.
   667 
   668 * The new class "domain" is now the default sort.  Class "predomain"
   669 is an unpointed version of "domain". Theories can be updated by
   670 replacing sort annotations as shown below.  INCOMPATIBILITY.
   671 
   672   'a::type ~> 'a::countable
   673   'a::cpo  ~> 'a::predomain
   674   'a::pcpo ~> 'a::domain
   675 
   676 * The old type class "rep" has been superseded by class "domain".
   677 Accordingly, users of the definitional package must remove any
   678 "default_sort rep" declarations.  INCOMPATIBILITY.
   679 
   680 * The domain package (definitional mode) now supports unpointed
   681 predomain argument types, as long as they are marked 'lazy'. (Strict
   682 arguments must be in class "domain".) For example, the following
   683 domain definition now works:
   684 
   685   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   686 
   687 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   688 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   689 'a option, and 'a list.  Additionally, it configures fixrec and the
   690 domain package to work with these types.  For example:
   691 
   692   fixrec isInl :: "('a + 'b) u -> tr"
   693     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   694 
   695   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   696 
   697 * The "(permissive)" option of fixrec has been replaced with a
   698 per-equation "(unchecked)" option. See
   699 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   700 
   701 * The "bifinite" class no longer fixes a constant "approx"; the class
   702 now just asserts that such a function exists.  INCOMPATIBILITY.
   703 
   704 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   705 defines an embedding of type 'a defl into udom by default; instances
   706 of "bifinite" and "domain" classes are available in
   707 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   708 
   709 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   710 
   711 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   712 
   713 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   714 
   715 * The function "cprod_map" has been renamed to "prod_map".
   716 INCOMPATIBILITY.
   717 
   718 * The monadic bind operator on each powerdomain has new binder syntax
   719 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   720 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   721 
   722 * The infix syntax for binary union on each powerdomain has changed
   723 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   724 syntax.  INCOMPATIBILITY.
   725 
   726 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   727 still supported as an input translation.
   728 
   729 * Renamed some theorems (the original names are also still available).
   730 
   731   expand_fun_below   ~> fun_below_iff
   732   below_fun_ext      ~> fun_belowI
   733   expand_cfun_eq     ~> cfun_eq_iff
   734   ext_cfun           ~> cfun_eqI
   735   expand_cfun_below  ~> cfun_below_iff
   736   below_cfun_ext     ~> cfun_belowI
   737   cont2cont_Rep_CFun ~> cont2cont_APP
   738 
   739 * The Abs and Rep functions for various types have changed names.
   740 Related theorem names have also changed to match. INCOMPATIBILITY.
   741 
   742   Rep_CFun  ~> Rep_cfun
   743   Abs_CFun  ~> Abs_cfun
   744   Rep_Sprod ~> Rep_sprod
   745   Abs_Sprod ~> Abs_sprod
   746   Rep_Ssum  ~> Rep_ssum
   747   Abs_Ssum  ~> Abs_ssum
   748 
   749 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   750 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   751 
   752 * Various changes to bisimulation/coinduction with domain package:
   753 
   754   - Definitions of "bisim" constants no longer mention definedness.
   755   - With mutual recursion, "bisim" predicate is now curried.
   756   - With mutual recursion, each type gets a separate coind theorem.
   757   - Variable names in bisim_def and coinduct rules have changed.
   758 
   759 INCOMPATIBILITY.
   760 
   761 * Case combinators generated by the domain package for type "foo" are
   762 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   763 
   764 * Several theorems have been renamed to more accurately reflect the
   765 names of constants and types involved.  INCOMPATIBILITY.
   766 
   767   thelub_const    ~> lub_const
   768   lub_const       ~> is_lub_const
   769   thelubI         ~> lub_eqI
   770   is_lub_lub      ~> is_lubD2
   771   lubI            ~> is_lub_lub
   772   unique_lub      ~> is_lub_unique
   773   is_ub_lub       ~> is_lub_rangeD1
   774   lub_bin_chain   ~> is_lub_bin_chain
   775   lub_fun         ~> is_lub_fun
   776   thelub_fun      ~> lub_fun
   777   thelub_cfun     ~> lub_cfun
   778   thelub_Pair     ~> lub_Pair
   779   lub_cprod       ~> is_lub_prod
   780   thelub_cprod    ~> lub_prod
   781   minimal_cprod   ~> minimal_prod
   782   inst_cprod_pcpo ~> inst_prod_pcpo
   783   UU_I            ~> bottomI
   784   compact_UU      ~> compact_bottom
   785   deflation_UU    ~> deflation_bottom
   786   finite_deflation_UU ~> finite_deflation_bottom
   787 
   788 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   789 
   790   sq_ord_less_eq_trans ~> below_eq_trans
   791   sq_ord_eq_less_trans ~> eq_below_trans
   792   refl_less            ~> below_refl
   793   trans_less           ~> below_trans
   794   antisym_less         ~> below_antisym
   795   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   796   box_less             ~> box_below
   797   rev_trans_less       ~> rev_below_trans
   798   not_less2not_eq      ~> not_below2not_eq
   799   less_UU_iff          ~> below_UU_iff
   800   flat_less_iff        ~> flat_below_iff
   801   adm_less             ~> adm_below
   802   adm_not_less         ~> adm_not_below
   803   adm_compact_not_less ~> adm_compact_not_below
   804   less_fun_def         ~> below_fun_def
   805   expand_fun_less      ~> fun_below_iff
   806   less_fun_ext         ~> fun_belowI
   807   less_discr_def       ~> below_discr_def
   808   discr_less_eq        ~> discr_below_eq
   809   less_unit_def        ~> below_unit_def
   810   less_cprod_def       ~> below_prod_def
   811   prod_lessI           ~> prod_belowI
   812   Pair_less_iff        ~> Pair_below_iff
   813   fst_less_iff         ~> fst_below_iff
   814   snd_less_iff         ~> snd_below_iff
   815   expand_cfun_less     ~> cfun_below_iff
   816   less_cfun_ext        ~> cfun_belowI
   817   injection_less       ~> injection_below
   818   less_up_def          ~> below_up_def
   819   not_Iup_less         ~> not_Iup_below
   820   Iup_less             ~> Iup_below
   821   up_less              ~> up_below
   822   Def_inject_less_eq   ~> Def_below_Def
   823   Def_less_is_eq       ~> Def_below_iff
   824   spair_less_iff       ~> spair_below_iff
   825   less_sprod           ~> below_sprod
   826   spair_less           ~> spair_below
   827   sfst_less_iff        ~> sfst_below_iff
   828   ssnd_less_iff        ~> ssnd_below_iff
   829   fix_least_less       ~> fix_least_below
   830   dist_less_one        ~> dist_below_one
   831   less_ONE             ~> below_ONE
   832   ONE_less_iff         ~> ONE_below_iff
   833   less_sinlD           ~> below_sinlD
   834   less_sinrD           ~> below_sinrD
   835 
   836 
   837 *** FOL and ZF ***
   838 
   839 * All constant names are now qualified internally and use proper
   840 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   841 
   842 
   843 *** ML ***
   844 
   845 * Antiquotation @{assert} inlines a function bool -> unit that raises
   846 Fail if the argument is false.  Due to inlining the source position of
   847 failed assertions is included in the error output.
   848 
   849 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   850 text is in practice always evaluated with a stable theory checkpoint.
   851 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   852 
   853 * Antiquotation @{theory A} refers to theory A from the ancestry of
   854 the current context, not any accidental theory loader state as before.
   855 Potential INCOMPATIBILITY, subtle change in semantics.
   856 
   857 * Syntax.pretty_priority (default 0) configures the required priority
   858 of pretty-printed output and thus affects insertion of parentheses.
   859 
   860 * Syntax.default_root (default "any") configures the inner syntax
   861 category (nonterminal symbol) for parsing of terms.
   862 
   863 * Former exception Library.UnequalLengths now coincides with
   864 ListPair.UnequalLengths.
   865 
   866 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   867 main functionality is provided by structure Simplifier.
   868 
   869 * Renamed raw "explode" function to "raw_explode" to emphasize its
   870 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   871 almost all situations.
   872 
   873 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   874 See implementation manual for further details on exceptions in
   875 Isabelle/ML.
   876 
   877 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   878 meaning.
   879 
   880 * Renamed structure PureThy to Pure_Thy and moved most of its
   881 operations to structure Global_Theory, to emphasize that this is
   882 rarely-used global-only stuff.
   883 
   884 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   885 instead (or tracing for high-volume output).
   886 
   887 * Configuration option show_question_marks only affects regular pretty
   888 printing of types and terms, not raw Term.string_of_vname.
   889 
   890 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   891 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   892 @{thms} for most purposes.
   893 
   894 * ML structure Unsynchronized is never opened, not even in Isar
   895 interaction mode as before.  Old Unsynchronized.set etc. have been
   896 discontinued -- use plain := instead.  This should be *rare* anyway,
   897 since modern tools always work via official context data, notably
   898 configuration options.
   899 
   900 * Parallel and asynchronous execution requires special care concerning
   901 interrupts.  Structure Exn provides some convenience functions that
   902 avoid working directly with raw Interrupt.  User code must not absorb
   903 interrupts -- intermediate handling (for cleanup etc.) needs to be
   904 followed by re-raising of the original exception.  Another common
   905 source of mistakes are "handle _" patterns, which make the meaning of
   906 the program subject to physical effects of the environment.
   907 
   908 
   909 
   910 New in Isabelle2009-2 (June 2010)
   911 ---------------------------------
   912 
   913 *** General ***
   914 
   915 * Authentic syntax for *all* logical entities (type classes, type
   916 constructors, term constants): provides simple and robust
   917 correspondence between formal entities and concrete syntax.  Within
   918 the parse tree / AST representations, "constants" are decorated by
   919 their category (class, type, const) and spelled out explicitly with
   920 their full internal name.
   921 
   922 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   923 and translations (translation rules and translation functions in ML).
   924 Some hints on upgrading:
   925 
   926   - Many existing uses of 'syntax' and 'translations' can be replaced
   927     by more modern 'type_notation', 'notation' and 'abbreviation',
   928     which are independent of this issue.
   929 
   930   - 'translations' require markup within the AST; the term syntax
   931     provides the following special forms:
   932 
   933       CONST c   -- produces syntax version of constant c from context
   934       XCONST c  -- literally c, checked as constant from context
   935       c         -- literally c, if declared by 'syntax'
   936 
   937     Plain identifiers are treated as AST variables -- occasionally the
   938     system indicates accidental variables via the error "rhs contains
   939     extra variables".
   940 
   941     Type classes and type constructors are marked according to their
   942     concrete syntax.  Some old translations rules need to be written
   943     for the "type" category, using type constructor application
   944     instead of pseudo-term application of the default category
   945     "logic".
   946 
   947   - 'parse_translation' etc. in ML may use the following
   948     antiquotations:
   949 
   950       @{class_syntax c}   -- type class c within parse tree / AST
   951       @{term_syntax c}    -- type constructor c within parse tree / AST
   952       @{const_syntax c}   -- ML version of "CONST c" above
   953       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   954 
   955   - Literal types within 'typed_print_translations', i.e. those *not*
   956     represented as pseudo-terms are represented verbatim.  Use @{class
   957     c} or @{type_name c} here instead of the above syntax
   958     antiquotations.
   959 
   960 Note that old non-authentic syntax was based on unqualified base
   961 names, so all of the above "constant" names would coincide.  Recall
   962 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   963 diagnose syntax problems.
   964 
   965 * Type constructors admit general mixfix syntax, not just infix.
   966 
   967 * Concrete syntax may be attached to local entities without a proof
   968 body, too.  This works via regular mixfix annotations for 'fix',
   969 'def', 'obtain' etc. or via the explicit 'write' command, which is
   970 similar to the 'notation' command in theory specifications.
   971 
   972 * Discontinued unnamed infix syntax (legacy feature for many years) --
   973 need to specify constant name and syntax separately.  Internal ML
   974 datatype constructors have been renamed from InfixName to Infix etc.
   975 Minor INCOMPATIBILITY.
   976 
   977 * Schematic theorem statements need to be explicitly markup as such,
   978 via commands 'schematic_lemma', 'schematic_theorem',
   979 'schematic_corollary'.  Thus the relevance of the proof is made
   980 syntactically clear, which impacts performance in a parallel or
   981 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   982 
   983 * Use of cumulative prems via "!" in some proof methods has been
   984 discontinued (old legacy feature).
   985 
   986 * References 'trace_simp' and 'debug_simp' have been replaced by
   987 configuration options stored in the context. Enabling tracing (the
   988 case of debugging is similar) in proofs works via
   989 
   990   using [[trace_simp = true]]
   991 
   992 Tracing is then active for all invocations of the simplifier in
   993 subsequent goal refinement steps. Tracing may also still be enabled or
   994 disabled via the ProofGeneral settings menu.
   995 
   996 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   997 'hide_fact' replace the former 'hide' KIND command.  Minor
   998 INCOMPATIBILITY.
   999 
  1000 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1001 more efficient than combinations with -q1 or -q2.
  1002 
  1003 
  1004 *** Pure ***
  1005 
  1006 * Proofterms record type-class reasoning explicitly, using the
  1007 "unconstrain" operation internally.  This eliminates all sort
  1008 constraints from a theorem and proof, introducing explicit
  1009 OFCLASS-premises.  On the proof term level, this operation is
  1010 automatically applied at theorem boundaries, such that closed proofs
  1011 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1012 inspect proof terms.
  1013 
  1014 * Local theory specifications may depend on extra type variables that
  1015 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1016 are added internally.  For example:
  1017 
  1018   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1019 
  1020 * Predicates of locales introduced by classes carry a mandatory
  1021 "class" prefix.  INCOMPATIBILITY.
  1022 
  1023 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1024 
  1025 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1026 'class' instead.
  1027 
  1028 * Command 'code_reflect' allows to incorporate generated ML code into
  1029 runtime environment; replaces immature code_datatype antiquotation.
  1030 INCOMPATIBILITY.
  1031 
  1032 * Code generator: simple concept for abstract datatypes obeying
  1033 invariants.
  1034 
  1035 * Code generator: details of internal data cache have no impact on the
  1036 user space functionality any longer.
  1037 
  1038 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1039 subgoals.  This is more appropriate for interpretations with 'where'.
  1040 INCOMPATIBILITY.
  1041 
  1042 * Command 'example_proof' opens an empty proof body.  This allows to
  1043 experiment with Isar, without producing any persistent result.
  1044 
  1045 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1046 within a local theory context, with explicit checking of the
  1047 constructors involved (in contrast to the raw 'syntax' versions).
  1048 
  1049 * Commands 'types' and 'typedecl' now work within a local theory
  1050 context -- without introducing dependencies on parameters or
  1051 assumptions, which is not possible in Isabelle/Pure.
  1052 
  1053 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1054 within a local theory context.  Minor INCOMPATIBILITY.
  1055 
  1056 
  1057 *** HOL ***
  1058 
  1059 * Command 'typedef' now works within a local theory context -- without
  1060 introducing dependencies on parameters or assumptions, which is not
  1061 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1062 contain multiple interpretations of local typedefs (with different
  1063 non-emptiness proofs), even in a global theory context.
  1064 
  1065 * New package for quotient types.  Commands 'quotient_type' and
  1066 'quotient_definition' may be used for defining types and constants by
  1067 quotient constructions.  An example is the type of integers created by
  1068 quotienting pairs of natural numbers:
  1069 
  1070   fun
  1071     intrel :: "(nat * nat) => (nat * nat) => bool"
  1072   where
  1073     "intrel (x, y) (u, v) = (x + v = u + y)"
  1074 
  1075   quotient_type int = "nat * nat" / intrel
  1076     by (auto simp add: equivp_def expand_fun_eq)
  1077 
  1078   quotient_definition
  1079     "0::int" is "(0::nat, 0::nat)"
  1080 
  1081 The method "lifting" can be used to lift of theorems from the
  1082 underlying "raw" type to the quotient type.  The example
  1083 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1084 construction and provides a reasoning infrastructure for finite sets.
  1085 
  1086 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1087 clash with new theory Quotient in Main HOL.
  1088 
  1089 * Moved the SMT binding into the main HOL session, eliminating
  1090 separate HOL-SMT session.
  1091 
  1092 * List membership infix mem operation is only an input abbreviation.
  1093 INCOMPATIBILITY.
  1094 
  1095 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1096 for future developements; former Library/Word.thy is still present in
  1097 the AFP entry RSAPPS.
  1098 
  1099 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1100 longer shadowed.  INCOMPATIBILITY.
  1101 
  1102 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1103 INCOMPATIBILITY.
  1104 
  1105 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1106 INCOMPATIBILITY.
  1107 
  1108 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1109 instead.  INCOMPATIBILITY.
  1110 
  1111 * Dropped several real-specific versions of lemmas about floor and
  1112 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1113 instead.  INCOMPATIBILITY.
  1114 
  1115   floor_number_of_eq         ~> floor_number_of
  1116   le_floor_eq_number_of      ~> number_of_le_floor
  1117   le_floor_eq_zero           ~> zero_le_floor
  1118   le_floor_eq_one            ~> one_le_floor
  1119   floor_less_eq_number_of    ~> floor_less_number_of
  1120   floor_less_eq_zero         ~> floor_less_zero
  1121   floor_less_eq_one          ~> floor_less_one
  1122   less_floor_eq_number_of    ~> number_of_less_floor
  1123   less_floor_eq_zero         ~> zero_less_floor
  1124   less_floor_eq_one          ~> one_less_floor
  1125   floor_le_eq_number_of      ~> floor_le_number_of
  1126   floor_le_eq_zero           ~> floor_le_zero
  1127   floor_le_eq_one            ~> floor_le_one
  1128   floor_subtract_number_of   ~> floor_diff_number_of
  1129   floor_subtract_one         ~> floor_diff_one
  1130   ceiling_number_of_eq       ~> ceiling_number_of
  1131   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1132   ceiling_le_zero_eq         ~> ceiling_le_zero
  1133   ceiling_le_eq_one          ~> ceiling_le_one
  1134   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1135   less_ceiling_eq_zero       ~> zero_less_ceiling
  1136   less_ceiling_eq_one        ~> one_less_ceiling
  1137   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1138   ceiling_less_eq_zero       ~> ceiling_less_zero
  1139   ceiling_less_eq_one        ~> ceiling_less_one
  1140   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1141   le_ceiling_eq_zero         ~> zero_le_ceiling
  1142   le_ceiling_eq_one          ~> one_le_ceiling
  1143   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1144   ceiling_subtract_one       ~> ceiling_diff_one
  1145 
  1146 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1147 application of the various fold combinators on finite sets.
  1148 
  1149 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1150 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1151 implementation.  INCOMPATIBILTY.
  1152 
  1153 * Theory Library/Coinductive_List has been removed -- superseded by
  1154 AFP/thys/Coinductive.
  1155 
  1156 * Theory PReal, including the type "preal" and related operations, has
  1157 been removed.  INCOMPATIBILITY.
  1158 
  1159 * Real: new development using Cauchy Sequences.
  1160 
  1161 * Split off theory "Big_Operators" containing setsum, setprod,
  1162 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1163 
  1164 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1165 "Int" etc.  INCOMPATIBILITY.
  1166 
  1167 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1168 
  1169 * New set of rules "ac_simps" provides combined assoc / commute
  1170 rewrites for all interpretations of the appropriate generic locales.
  1171 
  1172 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1173 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1174 appropriate and more consistent names suitable for name prefixes
  1175 within the HOL theories.  INCOMPATIBILITY.
  1176 
  1177 * Some generic constants have been put to appropriate theories:
  1178   - less_eq, less: Orderings
  1179   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1180   - inverse, divide: Rings
  1181 INCOMPATIBILITY.
  1182 
  1183 * More consistent naming of type classes involving orderings (and
  1184 lattices):
  1185 
  1186     lower_semilattice                   ~> semilattice_inf
  1187     upper_semilattice                   ~> semilattice_sup
  1188 
  1189     dense_linear_order                  ~> dense_linorder
  1190 
  1191     pordered_ab_group_add               ~> ordered_ab_group_add
  1192     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1193     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1194     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1195     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1196     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1197     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1198     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1199     pordered_comm_ring                  ~> ordered_comm_ring
  1200     pordered_comm_semiring              ~> ordered_comm_semiring
  1201     pordered_ring                       ~> ordered_ring
  1202     pordered_ring_abs                   ~> ordered_ring_abs
  1203     pordered_semiring                   ~> ordered_semiring
  1204 
  1205     ordered_ab_group_add                ~> linordered_ab_group_add
  1206     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1207     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1208     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1209     ordered_field                       ~> linordered_field
  1210     ordered_field_no_lb                 ~> linordered_field_no_lb
  1211     ordered_field_no_ub                 ~> linordered_field_no_ub
  1212     ordered_field_dense_linear_order    ~> dense_linordered_field
  1213     ordered_idom                        ~> linordered_idom
  1214     ordered_ring                        ~> linordered_ring
  1215     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1216     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1217     ordered_ring_strict                 ~> linordered_ring_strict
  1218     ordered_semidom                     ~> linordered_semidom
  1219     ordered_semiring                    ~> linordered_semiring
  1220     ordered_semiring_1                  ~> linordered_semiring_1
  1221     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1222     ordered_semiring_strict             ~> linordered_semiring_strict
  1223 
  1224   The following slightly odd type classes have been moved to a
  1225   separate theory Library/Lattice_Algebras:
  1226 
  1227     lordered_ab_group_add               ~> lattice_ab_group_add
  1228     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1229     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1230     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1231     lordered_ring                       ~> lattice_ring
  1232 
  1233 INCOMPATIBILITY.
  1234 
  1235 * Refined field classes:
  1236   - classes division_ring_inverse_zero, field_inverse_zero,
  1237     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1238     subsumes former division_by_zero class;
  1239   - numerous lemmas have been ported from field to division_ring.
  1240 INCOMPATIBILITY.
  1241 
  1242 * Refined algebra theorem collections:
  1243   - dropped theorem group group_simps, use algebra_simps instead;
  1244   - dropped theorem group ring_simps, use field_simps instead;
  1245   - proper theorem collection field_simps subsumes former theorem
  1246     groups field_eq_simps and field_simps;
  1247   - dropped lemma eq_minus_self_iff which is a duplicate for
  1248     equal_neg_zero.
  1249 INCOMPATIBILITY.
  1250 
  1251 * Theory Finite_Set and List: some lemmas have been generalized from
  1252 sets to lattices:
  1253 
  1254   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1255   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1256   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1257   union_Union_fold_union        ~> sup_Sup_fold_sup
  1258   Inter_fold_inter              ~> Inf_fold_inf
  1259   Union_fold_union              ~> Sup_fold_sup
  1260   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1261   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1262   INTER_fold_inter              ~> INFI_fold_inf
  1263   UNION_fold_union              ~> SUPR_fold_sup
  1264 
  1265 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1266 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1267 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1268 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1269 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1270 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1271 
  1272 * Reorganized theory Multiset: swapped notation of pointwise and
  1273 multiset order:
  1274 
  1275   - pointwise ordering is instance of class order with standard syntax
  1276     <= and <;
  1277   - multiset ordering has syntax <=# and <#; partial order properties
  1278     are provided by means of interpretation with prefix
  1279     multiset_order;
  1280   - less duplication, less historical organization of sections,
  1281     conversion from associations lists to multisets, rudimentary code
  1282     generation;
  1283   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1284     if needed.
  1285 
  1286 Renamed:
  1287 
  1288   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1289   multi_count_ext  ~>  multiset_ext
  1290   diff_union_inverse2  ~>  diff_union_cancelR
  1291 
  1292 INCOMPATIBILITY.
  1293 
  1294 * Theory Permutation: replaced local "remove" by List.remove1.
  1295 
  1296 * Code generation: ML and OCaml code is decorated with signatures.
  1297 
  1298 * Theory List: added transpose.
  1299 
  1300 * Library/Nat_Bijection.thy is a collection of bijective functions
  1301 between nat and other types, which supersedes the older libraries
  1302 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1303 
  1304   Constants:
  1305   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1306   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1307   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1308   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1309   Countable.pair_encode           ~> prod_encode
  1310   NatIso.prod2nat                 ~> prod_encode
  1311   NatIso.nat2prod                 ~> prod_decode
  1312   NatIso.sum2nat                  ~> sum_encode
  1313   NatIso.nat2sum                  ~> sum_decode
  1314   NatIso.list2nat                 ~> list_encode
  1315   NatIso.nat2list                 ~> list_decode
  1316   NatIso.set2nat                  ~> set_encode
  1317   NatIso.nat2set                  ~> set_decode
  1318 
  1319   Lemmas:
  1320   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1321   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1322   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1323   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1324   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1325   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1326   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1327   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1328   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1329   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1330   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1331   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1332   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1333 
  1334 * Sledgehammer:
  1335   - Renamed ATP commands:
  1336     atp_info     ~> sledgehammer running_atps
  1337     atp_kill     ~> sledgehammer kill_atps
  1338     atp_messages ~> sledgehammer messages
  1339     atp_minimize ~> sledgehammer minimize
  1340     print_atps   ~> sledgehammer available_atps
  1341     INCOMPATIBILITY.
  1342   - Added user's manual ("isabelle doc sledgehammer").
  1343   - Added option syntax and "sledgehammer_params" to customize
  1344     Sledgehammer's behavior.  See the manual for details.
  1345   - Modified the Isar proof reconstruction code so that it produces
  1346     direct proofs rather than proofs by contradiction.  (This feature
  1347     is still experimental.)
  1348   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1349     full-typed mode.
  1350   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1351 
  1352 * Nitpick:
  1353   - Added and implemented "binary_ints" and "bits" options.
  1354   - Added "std" option and implemented support for nonstandard models.
  1355   - Added and implemented "finitize" option to improve the precision
  1356     of infinite datatypes based on a monotonicity analysis.
  1357   - Added support for quotient types.
  1358   - Added support for "specification" and "ax_specification"
  1359     constructs.
  1360   - Added support for local definitions (for "function" and
  1361     "termination" proofs).
  1362   - Added support for term postprocessors.
  1363   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1364   - Improved efficiency of "destroy_constrs" optimization.
  1365   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1366     record getters.
  1367   - Fixed soundness bug related to higher-order constructors.
  1368   - Fixed soundness bug when "full_descrs" is enabled.
  1369   - Improved precision of set constructs.
  1370   - Added "atoms" option.
  1371   - Added cache to speed up repeated Kodkod invocations on the same
  1372     problems.
  1373   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1374     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1375     "SAT4J_Light".  INCOMPATIBILITY.
  1376   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1377     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1378   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1379 
  1380 * Method "induct" now takes instantiations of the form t, where t is not
  1381   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1382   If this is not intended, t has to be enclosed in parentheses.
  1383   By default, the equalities generated by definitional instantiations
  1384   are pre-simplified, which may cause parameters of inductive cases
  1385   to disappear, or may even delete some of the inductive cases.
  1386   Use "induct (no_simp)" instead of "induct" to restore the old
  1387   behaviour. The (no_simp) option is also understood by the "cases"
  1388   and "nominal_induct" methods, which now perform pre-simplification, too.
  1389   INCOMPATIBILITY.
  1390 
  1391 
  1392 *** HOLCF ***
  1393 
  1394 * Variable names in lemmas generated by the domain package have
  1395 changed; the naming scheme is now consistent with the HOL datatype
  1396 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1397 
  1398 * The domain package no longer defines the function "foo_copy" for
  1399 recursive domain "foo".  The reach lemma is now stated directly in
  1400 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1401 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1402 
  1403 * Most definedness lemmas generated by the domain package (previously
  1404 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1405 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1406 Proofs that used definedness lemmas as intro rules may break,
  1407 potential INCOMPATIBILITY.
  1408 
  1409 * Induction and casedist rules generated by the domain package now
  1410 declare proper case_names (one called "bottom", and one named for each
  1411 constructor).  INCOMPATIBILITY.
  1412 
  1413 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1414 rules are generated for each domain, INCOMPATIBILITY.
  1415 
  1416   foo_bar.reach       ~> foo.reach  bar.reach
  1417   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1418 
  1419 * Some lemmas generated by the domain package have been renamed for
  1420 consistency with the datatype package, INCOMPATIBILITY.
  1421 
  1422   foo.ind        ~> foo.induct
  1423   foo.finite_ind ~> foo.finite_induct
  1424   foo.coind      ~> foo.coinduct
  1425   foo.casedist   ~> foo.exhaust
  1426   foo.exhaust    ~> foo.nchotomy
  1427 
  1428 * For consistency with other definition packages, the fixrec package
  1429 now generates qualified theorem names, INCOMPATIBILITY.
  1430 
  1431   foo_simps  ~> foo.simps
  1432   foo_unfold ~> foo.unfold
  1433   foo_induct ~> foo.induct
  1434 
  1435 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1436 method and internal fixrec proofs now use the default simpset instead.
  1437 INCOMPATIBILITY.
  1438 
  1439 * The "contlub" predicate has been removed.  Proof scripts should use
  1440 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1441 
  1442 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1443 
  1444 * The constants cpair, cfst, and csnd have been removed in favor of
  1445 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1446 
  1447 
  1448 *** ML ***
  1449 
  1450 * Antiquotations for basic formal entities:
  1451 
  1452     @{class NAME}         -- type class
  1453     @{class_syntax NAME}  -- syntax representation of the above
  1454 
  1455     @{type_name NAME}     -- logical type
  1456     @{type_abbrev NAME}   -- type abbreviation
  1457     @{nonterminal NAME}   -- type of concrete syntactic category
  1458     @{type_syntax NAME}   -- syntax representation of any of the above
  1459 
  1460     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1461     @{const_abbrev NAME}  -- abbreviated constant
  1462     @{const_syntax NAME}  -- syntax representation of any of the above
  1463 
  1464 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1465 syntax constant (cf. 'syntax' command).
  1466 
  1467 * Antiquotation @{make_string} inlines a function to print arbitrary
  1468 values similar to the ML toplevel.  The result is compiler dependent
  1469 and may fall back on "?" in certain situations.
  1470 
  1471 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1472 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1473 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1474 not work with the asynchronous Isar document model.
  1475 
  1476 * Configuration options now admit dynamic default values, depending on
  1477 the context or even global references.
  1478 
  1479 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1480 uses an efficient external library if available (for Poly/ML).
  1481 
  1482 * Renamed some important ML structures, while keeping the old names
  1483 for some time as aliases within the structure Legacy:
  1484 
  1485   OuterKeyword  ~>  Keyword
  1486   OuterLex      ~>  Token
  1487   OuterParse    ~>  Parse
  1488   OuterSyntax   ~>  Outer_Syntax
  1489   PrintMode     ~>  Print_Mode
  1490   SpecParse     ~>  Parse_Spec
  1491   ThyInfo       ~>  Thy_Info
  1492   ThyLoad       ~>  Thy_Load
  1493   ThyOutput     ~>  Thy_Output
  1494   TypeInfer     ~>  Type_Infer
  1495 
  1496 Note that "open Legacy" simplifies porting of sources, but forgetting
  1497 to remove it again will complicate porting again in the future.
  1498 
  1499 * Most operations that refer to a global context are named
  1500 accordingly, e.g. Simplifier.global_context or
  1501 ProofContext.init_global.  There are some situations where a global
  1502 context actually works, but under normal circumstances one needs to
  1503 pass the proper local context through the code!
  1504 
  1505 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1506 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1507 Pretty.pp argument to merge, which is absent in the standard
  1508 Theory_Data version.
  1509 
  1510 * Sorts.certify_sort and derived "cert" operations for types and terms
  1511 no longer minimize sorts.  Thus certification at the boundary of the
  1512 inference kernel becomes invariant under addition of class relations,
  1513 which is an important monotonicity principle.  Sorts are now minimized
  1514 in the syntax layer only, at the boundary between the end-user and the
  1515 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1516 explicitly in rare situations.
  1517 
  1518 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1519 emphasize that this is in no way a standard operation.
  1520 INCOMPATIBILITY.
  1521 
  1522 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1523 usual for resolution.  Rare INCOMPATIBILITY.
  1524 
  1525 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1526 to emphasize that these only work in a global situation (which is
  1527 quite rare).
  1528 
  1529 * Curried take and drop in library.ML; negative length is interpreted
  1530 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1531 
  1532 * Proof terms: type substitutions on proof constants now use canonical
  1533 order of type variables.  INCOMPATIBILITY for tools working with proof
  1534 terms.
  1535 
  1536 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1537 may no longer carry premises.  User-level specifications are
  1538 transformed accordingly by Thm.add_axiom/add_def.
  1539 
  1540 
  1541 *** System ***
  1542 
  1543 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1544 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1545 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1546 
  1547 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1548 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1549 respectively.
  1550 
  1551 * Old lib/scripts/polyml-platform is superseded by the
  1552 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1553 variant, even on a 64 bit machine.  The following example setting
  1554 prefers 64 bit if available:
  1555 
  1556   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1557 
  1558 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1559 Isabelle/Scala layer for advanced prover interaction and integration.
  1560 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1561 component.
  1562 
  1563 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1564 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1565 similar to the default assignment of the document preparation system
  1566 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1567 provides some operations for direct access to the font without asking
  1568 the user for manual installation.
  1569 
  1570 
  1571 
  1572 New in Isabelle2009-1 (December 2009)
  1573 -------------------------------------
  1574 
  1575 *** General ***
  1576 
  1577 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1578 one backslash should be used, even in ML sources.
  1579 
  1580 
  1581 *** Pure ***
  1582 
  1583 * Locale interpretation propagates mixins along the locale hierarchy.
  1584 The currently only available mixins are the equations used to map
  1585 local definitions to terms of the target domain of an interpretation.
  1586 
  1587 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1588 loc" to print all interpretations of locale "loc" in the theory.
  1589 Interpretations in proofs are not shown.
  1590 
  1591 * Thoroughly revised locales tutorial.  New section on conditional
  1592 interpretation.
  1593 
  1594 * On instantiation of classes, remaining undefined class parameters
  1595 are formally declared.  INCOMPATIBILITY.
  1596 
  1597 
  1598 *** Document preparation ***
  1599 
  1600 * New generalized style concept for printing terms: @{foo (style) ...}
  1601 instead of @{foo_style style ...}  (old form is still retained for
  1602 backward compatibility).  Styles can be also applied for
  1603 antiquotations prop, term_type and typeof.
  1604 
  1605 
  1606 *** HOL ***
  1607 
  1608 * New proof method "smt" for a combination of first-order logic with
  1609 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1610 fixed-size bitvectors; there is also basic support for higher-order
  1611 features (esp. lambda abstractions).  It is an incomplete decision
  1612 procedure based on external SMT solvers using the oracle mechanism;
  1613 for the SMT solver Z3, this method is proof-producing.  Certificates
  1614 are provided to avoid calling the external solvers solely for
  1615 re-checking proofs.  Due to a remote SMT service there is no need for
  1616 installing SMT solvers locally.  See src/HOL/SMT.
  1617 
  1618 * New commands to load and prove verification conditions generated by
  1619 the Boogie program verifier or derived systems (e.g. the Verifying C
  1620 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1621 
  1622 * New counterexample generator tool 'nitpick' based on the Kodkod
  1623 relational model finder.  See src/HOL/Tools/Nitpick and
  1624 src/HOL/Nitpick_Examples.
  1625 
  1626 * New commands 'code_pred' and 'values' to invoke the predicate
  1627 compiler and to enumerate values of inductive predicates.
  1628 
  1629 * A tabled implementation of the reflexive transitive closure.
  1630 
  1631 * New implementation of quickcheck uses generic code generator;
  1632 default generators are provided for all suitable HOL types, records
  1633 and datatypes.  Old quickcheck can be re-activated importing theory
  1634 Library/SML_Quickcheck.
  1635 
  1636 * New testing tool Mirabelle for automated proof tools.  Applies
  1637 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1638 every proof step in a theory.  To be used in batch mode via the
  1639 "mirabelle" utility.
  1640 
  1641 * New proof method "sos" (sum of squares) for nonlinear real
  1642 arithmetic (originally due to John Harison). It requires theory
  1643 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1644 works well in practice on quantifier-free real arithmetic with +, -,
  1645 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1646 inequalities between polynomials.  It makes use of external
  1647 semidefinite programming solvers.  Method "sos" generates a
  1648 certificate that can be pasted into the proof thus avoiding the need
  1649 to call an external tool every time the proof is checked.  See
  1650 src/HOL/Library/Sum_Of_Squares.
  1651 
  1652 * New method "linarith" invokes existing linear arithmetic decision
  1653 procedure only.
  1654 
  1655 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1656 
  1657 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1658 Causes full type information to be output to the ATPs.  This slows
  1659 ATPs down considerably but eliminates a source of unsound "proofs"
  1660 that fail later.
  1661 
  1662 * New method "metisFT": A version of metis that uses full type
  1663 information in order to avoid failures of proof reconstruction.
  1664 
  1665 * New evaluator "approximate" approximates an real valued term using
  1666 the same method as the approximation method.
  1667 
  1668 * Method "approximate" now supports arithmetic expressions as
  1669 boundaries of intervals and implements interval splitting and Taylor
  1670 series expansion.
  1671 
  1672 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1673 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1674 
  1675 * New theory SupInf of the supremum and infimum operators for sets of
  1676 reals.
  1677 
  1678 * New theory Probability, which contains a development of measure
  1679 theory, eventually leading to Lebesgue integration and probability.
  1680 
  1681 * Extended Multivariate Analysis to include derivation and Brouwer's
  1682 fixpoint theorem.
  1683 
  1684 * Reorganization of number theory, INCOMPATIBILITY:
  1685   - new number theory development for nat and int, in theories Divides
  1686     and GCD as well as in new session Number_Theory
  1687   - some constants and facts now suffixed with _nat and _int
  1688     accordingly
  1689   - former session NumberTheory now named Old_Number_Theory, including
  1690     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1691   - moved theory Pocklington from src/HOL/Library to
  1692     src/HOL/Old_Number_Theory
  1693 
  1694 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1695 lcm of finite and infinite sets. It is shown that they form a complete
  1696 lattice.
  1697 
  1698 * Class semiring_div requires superclass no_zero_divisors and proof of
  1699 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1700 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1701 generalized to class semiring_div, subsuming former theorems
  1702 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1703 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1704 INCOMPATIBILITY.
  1705 
  1706 * Refinements to lattice classes and sets:
  1707   - less default intro/elim rules in locale variant, more default
  1708     intro/elim rules in class variant: more uniformity
  1709   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1710     le_inf_iff
  1711   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1712     sup_aci)
  1713   - renamed ACI to inf_sup_aci
  1714   - new class "boolean_algebra"
  1715   - class "complete_lattice" moved to separate theory
  1716     "Complete_Lattice"; corresponding constants (and abbreviations)
  1717     renamed and with authentic syntax:
  1718     Set.Inf ~>    Complete_Lattice.Inf
  1719     Set.Sup ~>    Complete_Lattice.Sup
  1720     Set.INFI ~>   Complete_Lattice.INFI
  1721     Set.SUPR ~>   Complete_Lattice.SUPR
  1722     Set.Inter ~>  Complete_Lattice.Inter
  1723     Set.Union ~>  Complete_Lattice.Union
  1724     Set.INTER ~>  Complete_Lattice.INTER
  1725     Set.UNION ~>  Complete_Lattice.UNION
  1726   - authentic syntax for
  1727     Set.Pow
  1728     Set.image
  1729   - mere abbreviations:
  1730     Set.empty               (for bot)
  1731     Set.UNIV                (for top)
  1732     Set.inter               (for inf, formerly Set.Int)
  1733     Set.union               (for sup, formerly Set.Un)
  1734     Complete_Lattice.Inter  (for Inf)
  1735     Complete_Lattice.Union  (for Sup)
  1736     Complete_Lattice.INTER  (for INFI)
  1737     Complete_Lattice.UNION  (for SUPR)
  1738   - object-logic definitions as far as appropriate
  1739 
  1740 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1741 Un_subset_iff are explicitly deleted as default simp rules; then also
  1742 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1743 deleted to achieve the desired effect.
  1744 
  1745 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1746 rules by default any longer; the same applies to min_max.inf_absorb1
  1747 etc.  INCOMPATIBILITY.
  1748 
  1749 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1750 pred_set_conv by default.  INCOMPATIBILITY.
  1751 
  1752 * Power operations on relations and functions are now one dedicated
  1753 constant "compow" with infix syntax "^^".  Power operation on
  1754 multiplicative monoids retains syntax "^" and is now defined generic
  1755 in class power.  INCOMPATIBILITY.
  1756 
  1757 * Relation composition "R O S" now has a more standard argument order:
  1758 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1759 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1760 break, since the O_assoc rule was not rewritten like this.  Fix using
  1761 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1762 
  1763 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1764 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1765 INCOMPATIBILITY.
  1766 
  1767 * Most rules produced by inductive and datatype package have mandatory
  1768 prefixes.  INCOMPATIBILITY.
  1769 
  1770 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1771 the attribute of the same name.  Each of the theorems in the list
  1772 DERIV_intros assumes composition with an additional function and
  1773 matches a variable to the derivative, which has to be solved by the
  1774 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1775 of most elementary terms.  Former Maclauren.DERIV_tac and
  1776 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1777 INCOMPATIBILITY.
  1778 
  1779 * Code generator attributes follow the usual underscore convention:
  1780     code_unfold     replaces    code unfold
  1781     code_post       replaces    code post
  1782     etc.
  1783   INCOMPATIBILITY.
  1784 
  1785 * Renamed methods:
  1786     sizechange -> size_change
  1787     induct_scheme -> induction_schema
  1788   INCOMPATIBILITY.
  1789 
  1790 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1791 INCOMPATIBILITY, use "undefined" directly.
  1792 
  1793 * Renamed theorems:
  1794     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1795     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1796     Suc_plus1 -> Suc_eq_plus1
  1797     *anti_sym -> *antisym*
  1798     vector_less_eq_def -> vector_le_def
  1799   INCOMPATIBILITY.
  1800 
  1801 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1802 INCOMPATIBILITY.
  1803 
  1804 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1805 INCOMPATIBILITY.
  1806 
  1807 
  1808 *** HOLCF ***
  1809 
  1810 * Theory Representable defines a class "rep" of domains that are
  1811 representable (via an ep-pair) in the universal domain type "udom".
  1812 Instances are provided for all type constructors defined in HOLCF.
  1813 
  1814 * The 'new_domain' command is a purely definitional version of the
  1815 domain package, for representable domains.  Syntax is identical to the
  1816 old domain package.  The 'new_domain' package also supports indirect
  1817 recursion using previously-defined type constructors.  See
  1818 src/HOLCF/ex/New_Domain.thy for examples.
  1819 
  1820 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1821 on the left-hand side of an equation, and then performs
  1822 simplification.  Rewriting is done using rules declared with the
  1823 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1824 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1825 
  1826 * The pattern-match compiler in 'fixrec' can now handle constructors
  1827 with HOL function types.  Pattern-match combinators for the Pair
  1828 constructor are pre-configured.
  1829 
  1830 * The 'fixrec' package now produces better fixed-point induction rules
  1831 for mutually-recursive definitions:  Induction rules have conclusions
  1832 of the form "P foo bar" instead of "P <foo, bar>".
  1833 
  1834 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1835 been renamed to "below".  The name "below" now replaces "less" in many
  1836 theorem names.  (Legacy theorem names using "less" are still supported
  1837 as well.)
  1838 
  1839 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1840 patterns can be used to generate strictness rules, or to make
  1841 functions more strict (much like the bang-patterns supported by the
  1842 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1843 examples.
  1844 
  1845 
  1846 *** ML ***
  1847 
  1848 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1849 errors and run-time exceptions, including detailed source positions.
  1850 
  1851 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1852 identified entries, with some additional information such as source
  1853 position, logical grouping etc.
  1854 
  1855 * Theory and context data is now introduced by the simplified and
  1856 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1857 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1858 copy operation) is still available for some time.
  1859 
  1860 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1861 provides a high-level programming interface to synchronized state
  1862 variables with atomic update.  This works via pure function
  1863 application within a critical section -- its runtime should be as
  1864 short as possible; beware of deadlocks if critical code is nested,
  1865 either directly or indirectly via other synchronized variables!
  1866 
  1867 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1868 wraps raw ML references, explicitly indicating their non-thread-safe
  1869 behaviour.  The Isar toplevel keeps this structure open, to
  1870 accommodate Proof General as well as quick and dirty interactive
  1871 experiments with references.
  1872 
  1873 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1874 parallel tactical reasoning.
  1875 
  1876 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1877 are similar to SUBPROOF, but are slightly more flexible: only the
  1878 specified parts of the subgoal are imported into the context, and the
  1879 body tactic may introduce new subgoals and schematic variables.
  1880 
  1881 * Old tactical METAHYPS, which does not observe the proof context, has
  1882 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1883 or Subgoal.FOCUS etc.
  1884 
  1885 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1886 functors have their own ML name space there is no point to mark them
  1887 separately.)  Minor INCOMPATIBILITY.
  1888 
  1889 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1890 
  1891 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1892 INCOMPATIBILITY.
  1893 
  1894 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1895 mode, which avoids critical setmp.
  1896 
  1897 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1898 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1899 Attrib/Method.setup introduced in Isabelle2009.
  1900 
  1901 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1902 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1903 last resort.  INCOMPATIBILITY.
  1904 
  1905 * Display.pretty_thm now requires a proper context (cf. former
  1906 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1907 or even Display.pretty_thm_without_context as last resort.
  1908 INCOMPATIBILITY.
  1909 
  1910 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1911 Syntax.pretty_typ/term directly, preferably with proper context
  1912 instead of global theory.
  1913 
  1914 
  1915 *** System ***
  1916 
  1917 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1918 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1919 usedir option -q.
  1920 
  1921 * Support for additional "Isabelle components" via etc/components, see
  1922 also the system manual.
  1923 
  1924 * The isabelle makeall tool now operates on all components with
  1925 IsaMakefile, not just hardwired "logics".
  1926 
  1927 * Removed "compress" option from isabelle-process and isabelle usedir;
  1928 this is always enabled.
  1929 
  1930 * Discontinued support for Poly/ML 4.x versions.
  1931 
  1932 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1933 on a given logic image.  This requires the lighttpd webserver and is
  1934 currently supported on Linux only.
  1935 
  1936 
  1937 
  1938 New in Isabelle2009 (April 2009)
  1939 --------------------------------
  1940 
  1941 *** General ***
  1942 
  1943 * Simplified main Isabelle executables, with less surprises on
  1944 case-insensitive file-systems (such as Mac OS).
  1945 
  1946   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1947     "isatool."
  1948 
  1949   - The former "isabelle" alias for "isabelle-process" has been
  1950     removed (should rarely occur to regular users).
  1951 
  1952   - The former "isabelle-interface" and its alias "Isabelle" have been
  1953     removed (interfaces are now regular Isabelle tools).
  1954 
  1955 Within scripts and make files, the Isabelle environment variables
  1956 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1957 respectively.  (The latter are still available as legacy feature.)
  1958 
  1959 The old isabelle-interface wrapper could react in confusing ways if
  1960 the interface was uninstalled or changed otherwise.  Individual
  1961 interface tool configuration is now more explicit, see also the
  1962 Isabelle system manual.  In particular, Proof General is now available
  1963 via "isabelle emacs".
  1964 
  1965 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1966 purge installed copies of Isabelle executables and re-run "isabelle
  1967 install -p ...", or use symlinks.
  1968 
  1969 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1970 old ~/isabelle, which was slightly non-standard and apt to cause
  1971 surprises on case-insensitive file-systems (such as Mac OS).
  1972 
  1973 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1974 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1975 care is required when using older releases of Isabelle.  Note that
  1976 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1977 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1978 
  1979 * Proofs of fully specified statements are run in parallel on
  1980 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1981 a regular 4-core machine, if the initial heap space is made reasonably
  1982 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1983 
  1984 * The main reference manuals ("isar-ref", "implementation", and
  1985 "system") have been updated and extended.  Formally checked references
  1986 as hyperlinks are now available uniformly.
  1987 
  1988 
  1989 *** Pure ***
  1990 
  1991 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1992 respects.  The most important changes are listed below.  See the
  1993 Tutorial on Locales ("locales" manual) for details.
  1994 
  1995 - In locale expressions, instantiation replaces renaming.  Parameters
  1996 must be declared in a for clause.  To aid compatibility with previous
  1997 parameter inheritance, in locale declarations, parameters that are not
  1998 'touched' (instantiation position "_" or omitted) are implicitly added
  1999 with their syntax at the beginning of the for clause.
  2000 
  2001 - Syntax from abbreviations and definitions in locales is available in
  2002 locale expressions and context elements.  The latter is particularly
  2003 useful in locale declarations.
  2004 
  2005 - More flexible mechanisms to qualify names generated by locale
  2006 expressions.  Qualifiers (prefixes) may be specified in locale
  2007 expressions, and can be marked as mandatory (syntax: "name!:") or
  2008 optional (syntax "name?:").  The default depends for plain "name:"
  2009 depends on the situation where a locale expression is used: in
  2010 commands 'locale' and 'sublocale' prefixes are optional, in
  2011 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2012 implicit qualifiers derived from the parameter names of a locale are
  2013 no longer generated.
  2014 
  2015 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2016 instantiation clause in "interpretation" and "interpret" (square
  2017 brackets) is no longer available.  Use locale expressions.
  2018 
  2019 - When converting proof scripts, mandatory qualifiers in
  2020 'interpretation' and 'interpret' should be retained by default, even
  2021 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2022 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2023 in locale expressions range over a single locale instance only.
  2024 
  2025 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2026 In existing theorem specifications replace the includes element by the
  2027 respective context elements of the included locale, omitting those
  2028 that are already present in the theorem specification.  Multiple
  2029 assume elements of a locale should be replaced by a single one
  2030 involving the locale predicate.  In the proof body, declarations (most
  2031 notably theorems) may be regained by interpreting the respective
  2032 locales in the proof context as required (command "interpret").
  2033 
  2034 If using "includes" in replacement of a target solely because the
  2035 parameter types in the theorem are not as general as in the target,
  2036 consider declaring a new locale with additional type constraints on
  2037 the parameters (context element "constrains").
  2038 
  2039 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2040 
  2041 - Locale interpretation commands no longer attempt to simplify goal.
  2042 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2043 methods intro_locales and unfold_locales to clarify.
  2044 
  2045 - Locale interpretation commands no longer accept interpretation
  2046 attributes.  INCOMPATIBILITY.
  2047 
  2048 * Class declaration: so-called "base sort" must not be given in import
  2049 list any longer, but is inferred from the specification.  Particularly
  2050 in HOL, write
  2051 
  2052     class foo = ...
  2053 
  2054 instead of
  2055 
  2056     class foo = type + ...
  2057 
  2058 * Class target: global versions of theorems stemming do not carry a
  2059 parameter prefix any longer.  INCOMPATIBILITY.
  2060 
  2061 * Class 'instance' command no longer accepts attached definitions.
  2062 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2063 
  2064 * Recovered hiding of consts, which was accidentally broken in
  2065 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2066 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2067 
  2068 * Slightly more coherent Pure syntax, with updated documentation in
  2069 isar-ref manual.  Removed locales meta_term_syntax and
  2070 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2071 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2072 directly in regular applications.
  2073 
  2074 * There is a new syntactic category "float_const" for signed decimal
  2075 fractions (e.g. 123.45 or -123.45).
  2076 
  2077 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2078 interface with 'setup' command instead.
  2079 
  2080 * Command 'local_setup' is similar to 'setup', but operates on a local
  2081 theory context.
  2082 
  2083 * The 'axiomatization' command now only works within a global theory
  2084 context.  INCOMPATIBILITY.
  2085 
  2086 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2087 hypotheses.  Sorts required in the course of reasoning need to be
  2088 covered by the constraints in the initial statement, completed by the
  2089 type instance information of the background theory.  Non-trivial sort
  2090 hypotheses, which rarely occur in practice, may be specified via
  2091 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2092 
  2093   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2094 
  2095 The result contains an implicit sort hypotheses as before --
  2096 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2097 normalization.
  2098 
  2099 * Generalized Isar history, with support for linear undo, direct state
  2100 addressing etc.
  2101 
  2102 * Changed defaults for unify configuration options:
  2103 
  2104   unify_trace_bound = 50 (formerly 25)
  2105   unify_search_bound = 60 (formerly 30)
  2106 
  2107 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2108 
  2109   a) On theory merge, the last set of code equations for a particular
  2110      constant is taken (in accordance with the policy applied by other
  2111      parts of the code generator framework).
  2112 
  2113   b) Code equations stemming from explicit declarations (e.g. code
  2114      attribute) gain priority over default code equations stemming
  2115      from definition, primrec, fun etc.
  2116 
  2117 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2118 
  2119 * Unified theorem tables for both code generators.  Thus [code
  2120 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2121 
  2122 * Command 'find_consts' searches for constants based on type and name
  2123 patterns, e.g.
  2124 
  2125     find_consts "_ => bool"
  2126 
  2127 By default, matching is against subtypes, but it may be restricted to
  2128 the whole type.  Searching by name is possible.  Multiple queries are
  2129 conjunctive and queries may be negated by prefixing them with a
  2130 hyphen:
  2131 
  2132     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2133 
  2134 * New 'find_theorems' criterion "solves" matches theorems that
  2135 directly solve the current goal (modulo higher-order unification).
  2136 
  2137 * Auto solve feature for main theorem statements: whenever a new goal
  2138 is stated, "find_theorems solves" is called; any theorems that could
  2139 solve the lemma directly are listed as part of the goal state.
  2140 Cf. associated options in Proof General Isabelle settings menu,
  2141 enabled by default, with reasonable timeout for pathological cases of
  2142 higher-order unification.
  2143 
  2144 
  2145 *** Document preparation ***
  2146 
  2147 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2148 demanding keyword 'by' and supporting the full method expression
  2149 syntax just like the Isar command 'by'.
  2150 
  2151 
  2152 *** HOL ***
  2153 
  2154 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2155 points Main and Complex_Main remain as before.
  2156 
  2157 * Logic image HOL-Plain provides a minimal HOL with the most important
  2158 tools available (inductive, datatype, primrec, ...).  This facilitates
  2159 experimentation and tool development.  Note that user applications
  2160 (and library theories) should never refer to anything below theory
  2161 Main, as before.
  2162 
  2163 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2164 experimentation due to shorter build times.
  2165 
  2166 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2167 were previously part of former HOL-Complex.  Entry point Hyperreal
  2168 remains valid, but theories formerly using Complex_Main should now use
  2169 new entry point Hypercomplex.
  2170 
  2171 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2172 Posix processes.  Avoids potentially expensive forking of the ML
  2173 process.  New thread-based implementation also works on non-Unix
  2174 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2175 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2176 commands are covered in the isar-ref manual.
  2177 
  2178 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2179 sledgehammer without local ATP installation (Vampire etc.). Other
  2180 provers may be included via suitable ML wrappers, see also
  2181 src/HOL/ATP_Linkup.thy.
  2182 
  2183 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2184 menu.
  2185 
  2186 * The metis method no longer fails because the theorem is too trivial
  2187 (contains the empty clause).
  2188 
  2189 * The metis method now fails in the usual manner, rather than raising
  2190 an exception, if it determines that it cannot prove the theorem.
  2191 
  2192 * Method "coherent" implements a prover for coherent logic (see also
  2193 src/Tools/coherent.ML).
  2194 
  2195 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2196 "undefined" is the right choice to replace "arbitrary", though
  2197 logically there is no difference.  INCOMPATIBILITY.
  2198 
  2199 * Command "value" now integrates different evaluation mechanisms.  The
  2200 result of the first successful evaluation mechanism is printed.  In
  2201 square brackets a particular named evaluation mechanisms may be
  2202 specified (currently, [SML], [code] or [nbe]).  See further
  2203 src/HOL/ex/Eval_Examples.thy.
  2204 
  2205 * Normalization by evaluation now allows non-leftlinear equations.
  2206 Declare with attribute [code nbe].
  2207 
  2208 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2209 as the structured Isar versions "cases" and "induct", cf. the
  2210 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2211 are now presented as a list of individual projections
  2212 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2213 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2214 rare situations a different rule is selected --- notably nested tuple
  2215 elimination instead of former prod.exhaust: use explicit (case_tac t
  2216 rule: prod.exhaust) here.
  2217 
  2218 * Attributes "cases", "induct", "coinduct" support "del" option.
  2219 
  2220 * Removed fact "case_split_thm", which duplicates "case_split".
  2221 
  2222 * The option datatype has been moved to a new theory Option.  Renamed
  2223 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2224 
  2225 * New predicate "strict_mono" classifies strict functions on partial
  2226 orders.  With strict functions on linear orders, reasoning about
  2227 (in)equalities is facilitated by theorems "strict_mono_eq",
  2228 "strict_mono_less_eq" and "strict_mono_less".
  2229 
  2230 * Some set operations are now proper qualified constants with
  2231 authentic syntax.  INCOMPATIBILITY:
  2232 
  2233     op Int ~>   Set.Int
  2234     op Un ~>    Set.Un
  2235     INTER ~>    Set.INTER
  2236     UNION ~>    Set.UNION
  2237     Inter ~>    Set.Inter
  2238     Union ~>    Set.Union
  2239     {} ~>       Set.empty
  2240     UNIV ~>     Set.UNIV
  2241 
  2242 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2243 theory Set.
  2244 
  2245 * Auxiliary class "itself" has disappeared -- classes without any
  2246 parameter are treated as expected by the 'class' command.
  2247 
  2248 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2249 
  2250 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2251 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2252 
  2253 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2254 method "approximation".  It proves formulas on real values by using
  2255 interval arithmetic.  In the formulas are also the transcendental
  2256 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2257 allowed. For examples see
  2258 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2259 
  2260 * Theory "Reflection" now resides in HOL/Library.
  2261 
  2262 * Entry point to Word library now simply named "Word".
  2263 INCOMPATIBILITY.
  2264 
  2265 * Made source layout more coherent with logical distribution
  2266 structure:
  2267 
  2268     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2269     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2270     src/HOL/Library/GCD.thy ~> src/HOL/
  2271     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2272     src/HOL/Library/Parity.thy ~> src/HOL/
  2273     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2274     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2275     src/HOL/Real/Lubs.thy ~> src/HOL/
  2276     src/HOL/Real/PReal.thy ~> src/HOL/
  2277     src/HOL/Real/Rational.thy ~> src/HOL/
  2278     src/HOL/Real/RComplete.thy ~> src/HOL/
  2279     src/HOL/Real/RealDef.thy ~> src/HOL/
  2280     src/HOL/Real/RealPow.thy ~> src/HOL/
  2281     src/HOL/Real/Real.thy ~> src/HOL/
  2282     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2283     src/HOL/Complex/Complex.thy ~> src/HOL/
  2284     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2285     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2286     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2287     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2288     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2289     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2290     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2291     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2292     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2293     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2294     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2295     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2296     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2297     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2298     src/HOL/Real/Float ~> src/HOL/Library/
  2299     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2300     src/HOL/Real/RealVector.thy ~> src/HOL/
  2301 
  2302     src/HOL/arith_data.ML ~> src/HOL/Tools
  2303     src/HOL/hologic.ML ~> src/HOL/Tools
  2304     src/HOL/simpdata.ML ~> src/HOL/Tools
  2305     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2306     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2307     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2308     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2309     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2310     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2311     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2312 
  2313     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2314     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2315     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2316     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2317     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2318     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2319 
  2320 * If methods "eval" and "evaluation" encounter a structured proof
  2321 state with !!/==>, only the conclusion is evaluated to True (if
  2322 possible), avoiding strange error messages.
  2323 
  2324 * Method "sizechange" automates termination proofs using (a
  2325 modification of) the size-change principle.  Requires SAT solver.  See
  2326 src/HOL/ex/Termination.thy for examples.
  2327 
  2328 * Simplifier: simproc for let expressions now unfolds if bound
  2329 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2330 
  2331 * Method "arith": Linear arithmetic now ignores all inequalities when
  2332 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2333 
  2334 * New attribute "arith" for facts that should always be used
  2335 automatically by arithmetic. It is intended to be used locally in
  2336 proofs, e.g.
  2337 
  2338   assumes [arith]: "x > 0"
  2339 
  2340 Global usage is discouraged because of possible performance impact.
  2341 
  2342 * New classes "top" and "bot" with corresponding operations "top" and
  2343 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2344 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2345 
  2346 * Changed definition lemma "less_fun_def" in order to provide an
  2347 instance for preorders on functions; use lemma "less_le" instead.
  2348 INCOMPATIBILITY.
  2349 
  2350 * Theory Orderings: class "wellorder" moved here, with explicit
  2351 induction rule "less_induct" as assumption.  For instantiation of
  2352 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2353 INCOMPATIBILITY.
  2354 
  2355 * Theory Orderings: added class "preorder" as superclass of "order".
  2356 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2357 etc. slightly changed.  Some theorems named order_class.* now named
  2358 preorder_class.*.
  2359 
  2360 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2361 "diag" to "Id_on".
  2362 
  2363 * Theory Finite_Set: added a new fold combinator of type
  2364 
  2365   ('a => 'b => 'b) => 'b => 'a set => 'b
  2366 
  2367 Occasionally this is more convenient than the old fold combinator
  2368 which is now defined in terms of the new one and renamed to
  2369 fold_image.
  2370 
  2371 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2372 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2373 extended with further lemmas!).  At the moment both still exist but
  2374 the former will disappear at some point.
  2375 
  2376 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2377 class recpower.  Type-specific simp rules for various recpower types
  2378 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2379 
  2380 rat_power_0    -> power_0
  2381 rat_power_Suc  -> power_Suc
  2382 realpow_0      -> power_0
  2383 realpow_Suc    -> power_Suc
  2384 complexpow_0   -> power_0
  2385 complexpow_Suc -> power_Suc
  2386 power_poly_0   -> power_0
  2387 power_poly_Suc -> power_Suc
  2388 
  2389 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2390 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2391 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2392 of lemmas from Divides has been generalized from nat to class
  2393 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2394 renames resulting from duplicate elimination:
  2395 
  2396     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2397     zero_dvd_iff ~>         dvd_0_left_iff
  2398     dvd_0 ~>                dvd_0_right
  2399     DIVISION_BY_ZERO_DIV ~> div_by_0
  2400     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2401     mult_div ~>             div_mult_self2_is_id
  2402     mult_mod ~>             mod_mult_self2_is_0
  2403 
  2404 * Theory IntDiv: removed many lemmas that are instances of class-based
  2405 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2406 rename old lemmas as follows:
  2407 
  2408 dvd_diff               -> nat_dvd_diff
  2409 dvd_zminus_iff         -> dvd_minus_iff
  2410 mod_add1_eq            -> mod_add_eq
  2411 mod_mult1_eq           -> mod_mult_right_eq
  2412 mod_mult1_eq'          -> mod_mult_left_eq
  2413 mod_mult_distrib_mod   -> mod_mult_eq
  2414 nat_mod_add_left_eq    -> mod_add_left_eq
  2415 nat_mod_add_right_eq   -> mod_add_right_eq
  2416 nat_mod_div_trivial    -> mod_div_trivial
  2417 nat_mod_mod_trivial    -> mod_mod_trivial
  2418 zdiv_zadd_self1        -> div_add_self1
  2419 zdiv_zadd_self2        -> div_add_self2
  2420 zdiv_zmult_self1       -> div_mult_self2_is_id
  2421 zdiv_zmult_self2       -> div_mult_self1_is_id
  2422 zdvd_triv_left         -> dvd_triv_left
  2423 zdvd_triv_right        -> dvd_triv_right
  2424 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2425 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2426 zmod_zadd_left_eq      -> mod_add_left_eq
  2427 zmod_zadd_right_eq     -> mod_add_right_eq
  2428 zmod_zadd_self1        -> mod_add_self1
  2429 zmod_zadd_self2        -> mod_add_self2
  2430 zmod_zadd1_eq          -> mod_add_eq
  2431 zmod_zdiff1_eq         -> mod_diff_eq
  2432 zmod_zdvd_zmod         -> mod_mod_cancel
  2433 zmod_zmod_cancel       -> mod_mod_cancel
  2434 zmod_zmult_self1       -> mod_mult_self2_is_0
  2435 zmod_zmult_self2       -> mod_mult_self1_is_0
  2436 zmod_1                 -> mod_by_1
  2437 zdiv_1                 -> div_by_1
  2438 zdvd_abs1              -> abs_dvd_iff
  2439 zdvd_abs2              -> dvd_abs_iff
  2440 zdvd_refl              -> dvd_refl
  2441 zdvd_trans             -> dvd_trans
  2442 zdvd_zadd              -> dvd_add
  2443 zdvd_zdiff             -> dvd_diff
  2444 zdvd_zminus_iff        -> dvd_minus_iff
  2445 zdvd_zminus2_iff       -> minus_dvd_iff
  2446 zdvd_zmultD            -> dvd_mult_right
  2447 zdvd_zmultD2           -> dvd_mult_left
  2448 zdvd_zmult_mono        -> mult_dvd_mono
  2449 zdvd_0_right           -> dvd_0_right
  2450 zdvd_0_left            -> dvd_0_left_iff
  2451 zdvd_1_left            -> one_dvd
  2452 zminus_dvd_iff         -> minus_dvd_iff
  2453 
  2454 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2455 
  2456 * The real numbers offer decimal input syntax: 12.34 is translated
  2457 into 1234/10^2. This translation is not reversed upon output.
  2458 
  2459 * Theory Library/Polynomial defines an abstract type 'a poly of
  2460 univariate polynomials with coefficients of type 'a.  In addition to
  2461 the standard ring operations, it also supports div and mod.  Code
  2462 generation is also supported, using list-style constructors.
  2463 
  2464 * Theory Library/Inner_Product defines a class of real_inner for real
  2465 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2466 => real.  Class real_inner is a subclass of real_normed_vector from
  2467 theory RealVector.
  2468 
  2469 * Theory Library/Product_Vector provides instances for the product
  2470 type 'a * 'b of several classes from RealVector and Inner_Product.
  2471 Definitions of addition, subtraction, scalar multiplication, norms,
  2472 and inner products are included.
  2473 
  2474 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2475 addition to the field operations, numerals and case syntax are also
  2476 supported.
  2477 
  2478 * Theory Library/Diagonalize provides constructive version of Cantor's
  2479 first diagonalization argument.
  2480 
  2481 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2482 zlcm (for int); carried together from various gcd/lcm developements in
  2483 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2484 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2485 may recover tupled syntax as follows:
  2486 
  2487     hide (open) const gcd
  2488     abbreviation gcd where
  2489       "gcd == (%(a, b). GCD.gcd a b)"
  2490     notation (output)
  2491       GCD.gcd ("gcd '(_, _')")
  2492 
  2493 The same works for lcm, zgcd, zlcm.
  2494 
  2495 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2496 instantiations for algebraic structures.  Removed some duplicate
  2497 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2498 
  2499 * ML antiquotation @{code} takes a constant as argument and generates
  2500 corresponding code in background and inserts name of the corresponding
  2501 resulting ML value/function/datatype constructor binding in place.
  2502 All occurrences of @{code} with a single ML block are generated
  2503 simultaneously.  Provides a generic and safe interface for
  2504 instrumentalizing code generation.  See
  2505 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2506 In future you ought to refrain from ad-hoc compiling generated SML
  2507 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2508 cannot refer to constants for which user-defined serializations are
  2509 set.  Refer to the corresponding ML counterpart directly in that
  2510 cases.
  2511 
  2512 * Command 'rep_datatype': instead of theorem names the command now
  2513 takes a list of terms denoting the constructors of the type to be
  2514 represented as datatype.  The characteristic theorems have to be
  2515 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2516 have disappeared in favour of existing ones:
  2517 
  2518     unit_induct                 ~> unit.induct
  2519     prod_induct                 ~> prod.induct
  2520     sum_induct                  ~> sum.induct
  2521     Suc_Suc_eq                  ~> nat.inject
  2522     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2523 
  2524 
  2525 *** HOL-Algebra ***
  2526 
  2527 * New locales for orders and lattices where the equivalence relation
  2528 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2529 locales use a record structure with field eq for the equivalence.
  2530 
  2531 * New theory of factorial domains.
  2532 
  2533 * Units_l_inv and Units_r_inv are now simp rules by default.
  2534 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2535 and/or r_inv will now also require deletion of these lemmas.
  2536 
  2537 * Renamed the following theorems, INCOMPATIBILITY:
  2538 
  2539 UpperD ~> Upper_memD
  2540 LowerD ~> Lower_memD
  2541 least_carrier ~> least_closed
  2542 greatest_carrier ~> greatest_closed
  2543 greatest_Lower_above ~> greatest_Lower_below
  2544 one_zero ~> carrier_one_zero
  2545 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2546 
  2547 
  2548 *** HOL-Nominal ***
  2549 
  2550 * Nominal datatypes can now contain type-variables.
  2551 
  2552 * Commands 'nominal_inductive' and 'equivariance' work with local
  2553 theory targets.
  2554 
  2555 * Nominal primrec can now works with local theory targets and its
  2556 specification syntax now conforms to the general format as seen in
  2557 'inductive' etc.
  2558 
  2559 * Method "perm_simp" honours the standard simplifier attributes
  2560 (no_asm), (no_asm_use) etc.
  2561 
  2562 * The new predicate #* is defined like freshness, except that on the
  2563 left hand side can be a set or list of atoms.
  2564 
  2565 * Experimental command 'nominal_inductive2' derives strong induction
  2566 principles for inductive definitions.  In contrast to
  2567 'nominal_inductive', which can only deal with a fixed number of
  2568 binders, it can deal with arbitrary expressions standing for sets of
  2569 atoms to be avoided.  The only inductive definition we have at the
  2570 moment that needs this generalisation is the typing rule for Lets in
  2571 the algorithm W:
  2572 
  2573  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2574  -----------------------------------------------------------------
  2575          Gamma |- Let x be t1 in t2 : T2
  2576 
  2577 In this rule one wants to avoid all the binders that are introduced by
  2578 "close Gamma T1".  We are looking for other examples where this
  2579 feature might be useful.  Please let us know.
  2580 
  2581 
  2582 *** HOLCF ***
  2583 
  2584 * Reimplemented the simplification procedure for proving continuity
  2585 subgoals.  The new simproc is extensible; users can declare additional
  2586 continuity introduction rules with the attribute [cont2cont].
  2587 
  2588 * The continuity simproc now uses a different introduction rule for
  2589 solving continuity subgoals on terms with lambda abstractions.  In
  2590 some rare cases the new simproc may fail to solve subgoals that the
  2591 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2592 Potential INCOMPATIBILITY.
  2593 
  2594 * Command 'fixrec': specification syntax now conforms to the general
  2595 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2596 examples.  INCOMPATIBILITY.
  2597 
  2598 
  2599 *** ZF ***
  2600 
  2601 * Proof of Zorn's Lemma for partial orders.
  2602 
  2603 
  2604 *** ML ***
  2605 
  2606 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2607 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2608 depends on multithreading, so timouts will not work before Poly/ML
  2609 5.2.1!
  2610 
  2611 * High-level support for concurrent ML programming, see
  2612 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2613 particularly convenient to organize independent functional
  2614 computations.  The concept of "synchronized variables" provides a
  2615 higher-order interface for components with shared state, avoiding the
  2616 delicate details of mutexes and condition variables.  (Requires
  2617 Poly/ML 5.2.1 or later.)
  2618 
  2619 * ML bindings produced via Isar commands are stored within the Isar
  2620 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2621 become thread-safe and work with undo as expected (concerning
  2622 top-level bindings, not side-effects on global references).
  2623 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2624 compiler at runtime; really global bindings need to be given outside a
  2625 theory.  (Requires Poly/ML 5.2 or later.)
  2626 
  2627 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2628 context.  Top-level ML bindings are stored within the proof context in
  2629 a purely sequential fashion, disregarding the nested proof structure.
  2630 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2631 proof.  (Requires Poly/ML 5.2 or later.)
  2632 
  2633 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2634 and Method.setup, as well as Isar commands 'attribute_setup' and
  2635 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2636 existing code accordingly, or use plain 'setup' together with old
  2637 Method.add_method.
  2638 
  2639 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2640 to 'a -> thm, while results are always tagged with an authentic oracle
  2641 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2642 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2643 accordingly.  Note that extra performance may be gained by producing
  2644 the cterm carefully, avoiding slow Thm.cterm_of.
  2645 
  2646 * Simplified interface for defining document antiquotations via
  2647 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2648 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2649 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2650 examples.
  2651 
  2652 * More systematic treatment of long names, abstract name bindings, and
  2653 name space operations.  Basic operations on qualified names have been
  2654 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2655 Long_Name.append.  Old type bstring has been mostly replaced by
  2656 abstract type binding (see structure Binding), which supports precise
  2657 qualification by packages and local theory targets, as well as proper
  2658 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2659 bstring values into Binding.name, or better pass through abstract
  2660 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2661 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2662 
  2663 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2664 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2665 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2666 
  2667 * Disposed old type and term read functions (Sign.read_def_typ,
  2668 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2669 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2670 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2671 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2672 resort for legacy applications.
  2673 
  2674 * Disposed old declarations, tactics, tactic combinators that refer to
  2675 the simpset or claset of an implicit theory (such as Addsimps,
  2676 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2677 embedded ML text, or local_simpset_of with a proper context passed as
  2678 explicit runtime argument.
  2679 
  2680 * Rules and tactics that read instantiations (read_instantiate,
  2681 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2682 context, which is required for parsing and type-checking.  Moreover,
  2683 the variables are specified as plain indexnames, not string encodings
  2684 thereof.  INCOMPATIBILITY.
  2685 
  2686 * Generic Toplevel.add_hook interface allows to analyze the result of
  2687 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2688 for theorem dependency output of transactions resulting in a new
  2689 theory state.
  2690 
  2691 * ML antiquotations: block-structured compilation context indicated by
  2692 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2693 
  2694   @{binding name}                         - basic name binding
  2695   @{let ?pat = term}                      - term abbreviation (HO matching)
  2696   @{note name = fact}                     - fact abbreviation
  2697   @{thm fact}                             - singleton fact (with attributes)
  2698   @{thms fact}                            - general fact (with attributes)
  2699   @{lemma prop by method}                 - singleton goal
  2700   @{lemma prop by meth1 meth2}            - singleton goal
  2701   @{lemma prop1 ... propN by method}      - general goal
  2702   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2703   @{lemma (open) ...}                     - open derivation
  2704 
  2705 
  2706 *** System ***
  2707 
  2708 * The Isabelle "emacs" tool provides a specific interface to invoke
  2709 Proof General / Emacs, with more explicit failure if that is not
  2710 installed (the old isabelle-interface script silently falls back on
  2711 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2712 installation location of the Proof General distribution.
  2713 
  2714 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2715 the Isabelle process into a JVM/Scala application.  See
  2716 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2717 process wrapper has been discontinued.)
  2718 
  2719 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2720 
  2721 * Various status messages (with exact source position information) are
  2722 emitted, if proper markup print mode is enabled.  This allows
  2723 user-interface components to provide detailed feedback on internal
  2724 prover operations.
  2725 
  2726 
  2727 
  2728 New in Isabelle2008 (June 2008)
  2729 -------------------------------
  2730 
  2731 *** General ***
  2732 
  2733 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2734 and updated, with formally checked references as hyperlinks.
  2735 
  2736 * Theory loader: use_thy (and similar operations) no longer set the
  2737 implicit ML context, which was occasionally hard to predict and in
  2738 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2739 provides a proper context already.
  2740 
  2741 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2742 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2743 'use' within a theory file will do the job.
  2744 
  2745 * Name space merge now observes canonical order, i.e. the second space
  2746 is inserted into the first one, while existing entries in the first
  2747 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2748 swap theory imports.
  2749 
  2750 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2751 INCOMPATIBILITY in identifier syntax etc.
  2752 
  2753 * Outer syntax: string tokens no longer admit escaped white space,
  2754 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2755 white space without escapes.
  2756 
  2757 * Outer syntax: string tokens may contain arbitrary character codes
  2758 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2759 "foo_bar".
  2760 
  2761 
  2762 *** Pure ***
  2763 
  2764 * Context-dependent token translations.  Default setup reverts locally
  2765 fixed variables, and adds hilite markup for undeclared frees.
  2766 
  2767 * Unused theorems can be found using the new command 'unused_thms'.
  2768 There are three ways of invoking it:
  2769 
  2770 (1) unused_thms
  2771      Only finds unused theorems in the current theory.
  2772 
  2773 (2) unused_thms thy_1 ... thy_n -
  2774      Finds unused theorems in the current theory and all of its ancestors,
  2775      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2776 
  2777 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2778      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2779      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2780      their ancestors.
  2781 
  2782 In order to increase the readability of the list produced by
  2783 unused_thms, theorems that have been created by a particular instance
  2784 of a theory command such as 'inductive' or 'function' are considered
  2785 to belong to the same "group", meaning that if at least one theorem in
  2786 this group is used, the other theorems in the same group are no longer
  2787 reported as unused.  Moreover, if all theorems in the group are
  2788 unused, only one theorem in the group is displayed.
  2789 
  2790 Note that proof objects have to be switched on in order for
  2791 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2792 usually the case when using Proof General with the default settings).
  2793 
  2794 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2795 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2796 duplicate fact bindings, or even accidental fact duplications.  Note
  2797 that tools may maintain dynamically scoped facts systematically, using
  2798 PureThy.add_thms_dynamic.
  2799 
  2800 * Command 'hide' now allows to hide from "fact" name space as well.
  2801 
  2802 * Eliminated destructive theorem database, simpset, claset, and
  2803 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2804 update of theories within ML code.
  2805 
  2806 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2807 INCOMPATIBILITY, object-logics depending on former Pure require
  2808 additional setup PureThy.old_appl_syntax_setup; object-logics
  2809 depending on former CPure need to refer to Pure.
  2810 
  2811 * Commands 'use' and 'ML' are now purely functional, operating on
  2812 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2813 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2814 INCOMPATIBILITY.
  2815 
  2816 * Command 'setup': discontinued implicit version with ML reference.
  2817 
  2818 * Instantiation target allows for simultaneous specification of class
  2819 instance operations together with an instantiation proof.
  2820 Type-checking phase allows to refer to class operations uniformly.
  2821 See src/HOL/Complex/Complex.thy for an Isar example and
  2822 src/HOL/Library/Eval.thy for an ML example.
  2823 
  2824 * Indexing of literal facts: be more serious about including only
  2825 facts from the visible specification/proof context, but not the
  2826 background context (locale etc.).  Affects `prop` notation and method
  2827 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2828 situations.
  2829 
  2830 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2831 "(open)" option, which used to expose internal bound variables to the
  2832 proof text.
  2833 
  2834 * Isar statements: removed obsolete case "rule_context".
  2835 INCOMPATIBILITY, better use explicit fixes/assumes.
  2836 
  2837 * Locale proofs: default proof step now includes 'unfold_locales';
  2838 hence 'proof' without argument may be used to unfold locale
  2839 predicates.
  2840 
  2841 
  2842 *** Document preparation ***
  2843 
  2844 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2845 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2846 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2847 spot); renamed link color from "darkblue" to "linkcolor" (default
  2848 value unchanged, can be redefined via \definecolor); no longer sets
  2849 "a4paper" option (unnecessary or even intrusive).
  2850 
  2851 * Antiquotation @{lemma A method} proves proposition A by the given
  2852 method (either a method name or a method name plus (optional) method
  2853 arguments in parentheses) and prints A just like @{prop A}.
  2854 
  2855 
  2856 *** HOL ***
  2857 
  2858 * New primrec package.  Specification syntax conforms in style to
  2859 definition/function/....  No separate induction rule is provided.  The
  2860 "primrec" command distinguishes old-style and new-style specifications
  2861 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2862 When adjusting theories, beware: constants stemming from new-style
  2863 primrec specifications have authentic syntax.
  2864 
  2865 * Metis prover is now an order of magnitude faster, and also works
  2866 with multithreading.
  2867 
  2868 * Metis: the maximum number of clauses that can be produced from a
  2869 theorem is now given by the attribute max_clauses.  Theorems that
  2870 exceed this number are ignored, with a warning printed.
  2871 
  2872 * Sledgehammer no longer produces structured proofs by default. To
  2873 enable, declare [[sledgehammer_full = true]].  Attributes
  2874 reconstruction_modulus, reconstruction_sorts renamed
  2875 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2876 
  2877 * Method "induct_scheme" derives user-specified induction rules
  2878 from well-founded induction and completeness of patterns. This factors
  2879 out some operations that are done internally by the function package
  2880 and makes them available separately.  See
  2881 src/HOL/ex/Induction_Scheme.thy for examples.
  2882 
  2883 * More flexible generation of measure functions for termination
  2884 proofs: Measure functions can be declared by proving a rule of the
  2885 form "is_measure f" and giving it the [measure_function] attribute.
  2886 The "is_measure" predicate is logically meaningless (always true), and
  2887 just guides the heuristic.  To find suitable measure functions, the
  2888 termination prover sets up the goal "is_measure ?f" of the appropriate
  2889 type and generates all solutions by prolog-style backwards proof using
  2890 the declared rules.
  2891 
  2892 This setup also deals with rules like 
  2893 
  2894   "is_measure f ==> is_measure (list_size f)"
  2895 
  2896 which accommodates nested datatypes that recurse through lists.
  2897 Similar rules are predeclared for products and option types.
  2898 
  2899 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2900 
  2901   INCOMPATIBILITIES:
  2902 
  2903   - Definitions of overloaded constants on sets have to be replaced by
  2904     definitions on => and bool.
  2905 
  2906   - Some definitions of overloaded operators on sets can now be proved
  2907     using the definitions of the operators on => and bool.  Therefore,
  2908     the following theorems have been renamed:
  2909 
  2910       subset_def   -> subset_eq
  2911       psubset_def  -> psubset_eq
  2912       set_diff_def -> set_diff_eq
  2913       Compl_def    -> Compl_eq
  2914       Sup_set_def  -> Sup_set_eq
  2915       Inf_set_def  -> Inf_set_eq
  2916       sup_set_def  -> sup_set_eq
  2917       inf_set_def  -> inf_set_eq
  2918 
  2919   - Due to the incompleteness of the HO unification algorithm, some
  2920     rules such as subst may require manual instantiation, if some of
  2921     the unknowns in the rule is a set.
  2922 
  2923   - Higher order unification and forward proofs:
  2924     The proof pattern
  2925 
  2926       have "P (S::'a set)" <...>
  2927       then have "EX S. P S" ..
  2928 
  2929     no longer works (due to the incompleteness of the HO unification
  2930     algorithm) and must be replaced by the pattern
  2931 
  2932       have "EX S. P S"
  2933       proof
  2934         show "P S" <...>
  2935       qed
  2936 
  2937   - Calculational reasoning with subst (or similar rules):
  2938     The proof pattern
  2939 
  2940       have "P (S::'a set)" <...>
  2941       also have "S = T" <...>
  2942       finally have "P T" .
  2943 
  2944     no longer works (for similar reasons as the previous example) and
  2945     must be replaced by something like
  2946 
  2947       have "P (S::'a set)" <...>
  2948       moreover have "S = T" <...>
  2949       ultimately have "P T" by simp
  2950 
  2951   - Tactics or packages written in ML code:
  2952     Code performing pattern matching on types via
  2953 
  2954       Type ("set", [T]) => ...
  2955 
  2956     must be rewritten. Moreover, functions like strip_type or
  2957     binder_types no longer return the right value when applied to a
  2958     type of the form
  2959 
  2960       T1 => ... => Tn => U => bool
  2961 
  2962     rather than
  2963 
  2964       T1 => ... => Tn => U set
  2965 
  2966 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2967 Wellfounded_Relations to theory Wellfounded.
  2968 
  2969 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2970 
  2971 * Class finite no longer treats UNIV as class parameter.  Use class
  2972 enum from theory Library/Enum instead to achieve a similar effect.
  2973 INCOMPATIBILITY.
  2974 
  2975 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2976 and "Cons".  INCOMPATIBILITY.
  2977 
  2978 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2979 Potential INCOMPATIBILITY.
  2980 
  2981 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2982 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2983 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2984 
  2985 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2986 the same name in theory Orderings:
  2987 
  2988   less_trans
  2989   less_linear
  2990   le_imp_less_or_eq
  2991   le_less_trans
  2992   less_le_trans
  2993   less_not_sym
  2994   less_asym
  2995 
  2996 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2997 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2998 and different variable names.
  2999 
  3000 * Library/Option_ord.thy: Canonical order on option type.
  3001 
  3002 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3003 finite maps.
  3004 
  3005 * Library/Countable.thy: Type class for countable types.
  3006 
  3007 * Theory Int: The representation of numerals has changed.  The infix
  3008 operator BIT and the bit datatype with constructors B0 and B1 have
  3009 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3010 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3011 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3012 accordingly.
  3013 
  3014 * Theory Nat: definition of <= and < on natural numbers no longer
  3015 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3016 le_def and less_def have disappeared.  Consider lemmas not_less
  3017 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3018 
  3019 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3020 (whose purpose mainly is for various fold_set functionals) have been
  3021 abandoned in favor of the existing algebraic classes
  3022 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3023 lower_semilattice (resp. upper_semilattice) and linorder.
  3024 INCOMPATIBILITY.
  3025 
  3026 * Theory Transitive_Closure: induct and cases rules now declare proper
  3027 case_names ("base" and "step").  INCOMPATIBILITY.
  3028 
  3029 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3030 lattices.  The form set-specific version is available as
  3031 Inductive.lfp_ordinal_induct_set.
  3032 
  3033 * Renamed theorems "power.simps" to "power_int.simps".
  3034 INCOMPATIBILITY.
  3035 
  3036 * Class semiring_div provides basic abstract properties of semirings
  3037 with division and modulo operations.  Subsumes former class dvd_mod.
  3038 
  3039 * Merged theories IntDef, Numeral and IntArith into unified theory
  3040 Int.  INCOMPATIBILITY.
  3041 
  3042 * Theory Library/Code_Index: type "index" now represents natural
  3043 numbers rather than integers.  INCOMPATIBILITY.
  3044 
  3045 * New class "uminus" with operation "uminus" (split of from class
  3046 "minus" which now only has operation "minus", binary).
  3047 INCOMPATIBILITY.
  3048 
  3049 * Constants "card", "internal_split", "option_map" now with authentic
  3050 syntax.  INCOMPATIBILITY.
  3051 
  3052 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3053 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3054 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3055 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3056 Sup_set_def, le_def, less_def, option_map_def now with object
  3057 equality.  INCOMPATIBILITY.
  3058 
  3059 * Records. Removed K_record, and replaced it by pure lambda term
  3060 %x. c. The simplifier setup is now more robust against eta expansion.
  3061 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3062 
  3063 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3064 
  3065 * Library/ListVector: new theory of arithmetic vector operations.
  3066 
  3067 * Library/Order_Relation: new theory of various orderings as sets of
  3068 pairs.  Defines preorders, partial orders, linear orders and
  3069 well-orders on sets and on types.
  3070 
  3071 
  3072 *** ZF ***
  3073 
  3074 * Renamed some theories to allow to loading both ZF and HOL in the
  3075 same session:
  3076 
  3077   Datatype  -> Datatype_ZF
  3078   Inductive -> Inductive_ZF
  3079   Int       -> Int_ZF
  3080   IntDiv    -> IntDiv_ZF
  3081   Nat       -> Nat_ZF
  3082   List      -> List_ZF
  3083   Main      -> Main_ZF
  3084 
  3085 INCOMPATIBILITY: ZF theories that import individual theories below
  3086 Main might need to be adapted.  Regular theory Main is still
  3087 available, as trivial extension of Main_ZF.
  3088 
  3089 
  3090 *** ML ***
  3091 
  3092 * ML within Isar: antiquotation @{const name} or @{const
  3093 name(typargs)} produces statically-checked Const term.
  3094 
  3095 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3096 (of the same name).  Removed obsolete print command.
  3097 
  3098 * Removed obsolete "use_legacy_bindings" function.
  3099 
  3100 * The ``print mode'' is now a thread-local value derived from a global
  3101 template (the former print_mode reference), thus access becomes
  3102 non-critical.  The global print_mode reference is for session
  3103 management only; user-code should use print_mode_value,
  3104 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3105 
  3106 * Functions system/system_out provide a robust way to invoke external
  3107 shell commands, with propagation of interrupts (requires Poly/ML
  3108 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3109 
  3110 
  3111 *** System ***
  3112 
  3113 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3114 in accordance with Proof General 3.7, which prefers GNU emacs.
  3115 
  3116 * isatool tty runs Isabelle process with plain tty interaction;
  3117 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3118 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3119 
  3120 * isatool browser now works with Cygwin as well, using general
  3121 "javapath" function defined in Isabelle process environment.
  3122 
  3123 * YXML notation provides a simple and efficient alternative to
  3124 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3125 isatool yxml as described in the Isabelle system manual.
  3126 
  3127 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3128 provides general wrapper for managing an Isabelle process in a robust
  3129 fashion, with ``cooked'' output from stdin/stderr.
  3130 
  3131 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3132 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3133 
  3134 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3135 way of changing the user's settings is via
  3136 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3137 script.
  3138 
  3139 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3140 cores of the underlying machine, which is a good starting point for
  3141 optimal performance tuning.  The corresponding usedir option -M allows
  3142 "max" as an alias for "0".  WARNING: does not work on certain versions
  3143 of Mac OS (with Poly/ML 5.1).
  3144 
  3145 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3146 adverse effect of Isabelle flooding interactive front-ends (notably
  3147 ProofGeneral / XEmacs).
  3148 
  3149 
  3150 
  3151 New in Isabelle2007 (November 2007)
  3152 -----------------------------------
  3153 
  3154 *** General ***
  3155 
  3156 * More uniform information about legacy features, notably a
  3157 warning/error of "Legacy feature: ...", depending on the state of the
  3158 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3159 legacy features will disappear eventually.
  3160 
  3161 * Theory syntax: the header format ``theory A = B + C:'' has been
  3162 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3163 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3164 
  3165 * Theory syntax: the old non-Isar theory file format has been
  3166 discontinued altogether.  Note that ML proof scripts may still be used
  3167 with Isar theories; migration is usually quite simple with the ML
  3168 function use_legacy_bindings.  INCOMPATIBILITY.
  3169 
  3170 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3171 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3172 quotes.
  3173 
  3174 * Theory loader: be more serious about observing the static theory
  3175 header specifications (including optional directories), but not the
  3176 accidental file locations of previously successful loads.  The strict
  3177 update policy of former update_thy is now already performed by
  3178 use_thy, so the former has been removed; use_thys updates several
  3179 theories simultaneously, just as 'imports' within a theory header
  3180 specification, but without merging the results.  Potential
  3181 INCOMPATIBILITY: may need to refine theory headers and commands
  3182 ROOT.ML which depend on load order.
  3183 
  3184 * Theory loader: optional support for content-based file
  3185 identification, instead of the traditional scheme of full physical
  3186 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3187 (cf. the system manual).  The new scheme allows to work with
  3188 non-finished theories in persistent session images, such that source
  3189 files may be moved later on without requiring reloads.
  3190 
  3191 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3192 file (with the same base name as the theory) are considered a legacy
  3193 feature, which will disappear eventually. Even now, the theory loader
  3194 no longer maintains dependencies on such files.
  3195 
  3196 * Syntax: the scope for resolving ambiguities via type-inference is
  3197 now limited to individual terms, instead of whole simultaneous
  3198 specifications as before. This greatly reduces the complexity of the
  3199 syntax module and improves flexibility by separating parsing and
  3200 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3201 'fixes' etc.) are required in rare situations.
  3202 
  3203 * Syntax: constants introduced by new-style packages ('definition',
  3204 'abbreviation' etc.) are passed through the syntax module in
  3205 ``authentic mode''. This means that associated mixfix annotations
  3206 really stick to such constants, independently of potential name space
  3207 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3208 trees are represented slightly differently, may need to adapt syntax
  3209 translations accordingly. Use CONST marker in 'translations' and
  3210 @{const_syntax} antiquotation in 'parse_translation' etc.
  3211 
  3212 * Legacy goal package: reduced interface to the bare minimum required
  3213 to keep existing proof scripts running.  Most other user-level
  3214 functions are now part of the OldGoals structure, which is *not* open
  3215 by default (consider isatool expandshort before open OldGoals).
  3216 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3217 these tend to cause confusion about the actual goal (!) context being
  3218 used here, which is not necessarily the same as the_context().
  3219 
  3220 * Command 'find_theorems': supports "*" wild-card in "name:"
  3221 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3222 support a specific search form (see ProofGeneral/CHANGES).
  3223 
  3224 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3225 by default, which means that "prems" (and also "fixed variables") are
  3226 suppressed from proof state output.  Note that the ProofGeneral
  3227 settings mechanism allows to change and save options persistently, but
  3228 older versions of Isabelle will fail to start up if a negative prems
  3229 limit is imposed.
  3230 
  3231 * Local theory targets may be specified by non-nested blocks of
  3232 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3233 contain definitions, theorems etc., including any derived mechanism
  3234 that has been implemented on top of these primitives.  This concept
  3235 generalizes the existing ``theorem (in ...)'' towards more versatility
  3236 and scalability.
  3237 
  3238 * Proof General interface: proper undo of final 'end' command;
  3239 discontinued Isabelle/classic mode (ML proof scripts).
  3240 
  3241 
  3242 *** Document preparation ***
  3243 
  3244 * Added antiquotation @{theory name} which prints the given name,
  3245 after checking that it refers to a valid ancestor theory in the
  3246 current context.
  3247 
  3248 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3249 check the given source text as ML type/structure, printing verbatim.
  3250 
  3251 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3252 "c args == rhs" given in the current context.  (Any number of
  3253 arguments may be given on the LHS.)
  3254 
  3255 
  3256 *** Pure ***
  3257 
  3258 * The 'class' package offers a combination of axclass and locale to
  3259 achieve Haskell-like type classes in Isabelle.  Definitions and
  3260 theorems within a class context produce both relative results (with
  3261 implicit parameters according to the locale context), and polymorphic
  3262 constants with qualified polymorphism (according to the class
  3263 context).  Within the body context of a 'class' target, a separate
  3264 syntax layer ("user space type system") takes care of converting
  3265 between global polymorphic consts and internal locale representation.
  3266 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3267 "isatool doc classes" provides a tutorial.
  3268 
  3269 * Generic code generator framework allows to generate executable
  3270 code for ML and Haskell (including Isabelle classes).  A short usage
  3271 sketch:
  3272 
  3273     internal compilation:
  3274         export_code <list of constants (term syntax)> in SML
  3275     writing SML code to a file:
  3276         export_code <list of constants (term syntax)> in SML <filename>
  3277     writing OCaml code to a file:
  3278         export_code <list of constants (term syntax)> in OCaml <filename>
  3279     writing Haskell code to a bunch of files:
  3280         export_code <list of constants (term syntax)> in Haskell <filename>
  3281 
  3282     evaluating closed propositions to True/False using code generation:
  3283         method ``eval''
  3284 
  3285 Reasonable default setup of framework in HOL.
  3286 
  3287 Theorem attributs for selecting and transforming function equations theorems:
  3288 
  3289     [code fun]:        select a theorem as function equation for a specific constant
  3290     [code fun del]:    deselect a theorem as function equation for a specific constant
  3291     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3292     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3293 
  3294 User-defined serializations (target in {SML, OCaml, Haskell}):
  3295 
  3296     code_const <and-list of constants (term syntax)>
  3297       {(target) <and-list of const target syntax>}+
  3298 
  3299     code_type <and-list of type constructors>
  3300       {(target) <and-list of type target syntax>}+
  3301 
  3302     code_instance <and-list of instances>
  3303       {(target)}+
  3304         where instance ::= <type constructor> :: <class>
  3305 
  3306     code_class <and_list of classes>
  3307       {(target) <and-list of class target syntax>}+
  3308         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3309 
  3310 code_instance and code_class only are effective to target Haskell.
  3311 
  3312 For example usage see src/HOL/ex/Codegenerator.thy and
  3313 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3314 generation from Isabelle/HOL theories is available via "isatool doc
  3315 codegen".
  3316 
  3317 * Code generator: consts in 'consts_code' Isar commands are now
  3318 referred to by usual term syntax (including optional type
  3319 annotations).
  3320 
  3321 * Command 'no_translations' removes translation rules from theory
  3322 syntax.
  3323 
  3324 * Overloaded definitions are now actually checked for acyclic
  3325 dependencies.  The overloading scheme is slightly more general than
  3326 that of Haskell98, although Isabelle does not demand an exact
  3327 correspondence to type class and instance declarations.
  3328 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3329 exotic versions of overloading -- at the discretion of the user!
  3330 
  3331 Polymorphic constants are represented via type arguments, i.e. the
  3332 instantiation that matches an instance against the most general
  3333 declaration given in the signature.  For example, with the declaration
  3334 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3335 as c(nat).  Overloading is essentially simultaneous structural
  3336 recursion over such type arguments.  Incomplete specification patterns
  3337 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3338 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3339 Command 'print_theory' outputs the normalized system of recursive
  3340 equations, see section "definitions".
  3341 
  3342 * Configuration options are maintained within the theory or proof
  3343 context (with name and type bool/int/string), providing a very simple
  3344 interface to a poor-man's version of general context data.  Tools may
  3345 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3346 these values using Config.get etc.  Users may change options via an
  3347 associated attribute of the same name.  This form of context
  3348 declaration works particularly well with commands 'declare' or
  3349 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3350 very easy to avoid global references, which would not observe Isar
  3351 toplevel undo/redo and fail to work with multithreading.
  3352 
  3353 Various global ML references of Pure and HOL have been turned into
  3354 configuration options:
  3355 
  3356   Unify.search_bound		unify_search_bound
  3357   Unify.trace_bound		unify_trace_bound
  3358   Unify.trace_simp		unify_trace_simp
  3359   Unify.trace_types		unify_trace_types
  3360   Simplifier.simp_depth_limit	simp_depth_limit
  3361   Blast.depth_limit		blast_depth_limit
  3362   DatatypeProp.dtK		datatype_distinctness_limit
  3363   fast_arith_neq_limit  	fast_arith_neq_limit
  3364   fast_arith_split_limit	fast_arith_split_limit
  3365 
  3366 * Named collections of theorems may be easily installed as context
  3367 data using the functor NamedThmsFun (see also
  3368 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3369 attributes; there is also a toplevel print command.  This facility is
  3370 just a common case of general context data, which is the preferred way
  3371 for anything more complex than just a list of facts in canonical
  3372 order.
  3373 
  3374 * Isar: command 'declaration' augments a local theory by generic
  3375 declaration functions written in ML.  This enables arbitrary content
  3376 being added to the context, depending on a morphism that tells the
  3377 difference of the original declaration context wrt. the application
  3378 context encountered later on.
  3379 
  3380 * Isar: proper interfaces for simplification procedures.  Command
  3381 'simproc_setup' declares named simprocs (with match patterns, and body
  3382 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3383 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3384 
  3385 * Isar: an extra pair of brackets around attribute declarations
  3386 abbreviates a theorem reference involving an internal dummy fact,
  3387 which will be ignored later --- only the effect of the attribute on
  3388 the background context will persist.  This form of in-place
  3389 declarations is particularly useful with commands like 'declare' and
  3390 'using', for example ``have A using [[simproc a]] by simp''.
  3391 
  3392 * Isar: method "assumption" (and implicit closing of subproofs) now
  3393 takes simple non-atomic goal assumptions into account: after applying
  3394 an assumption as a rule the resulting subgoals are solved by atomic
  3395 assumption steps.  This is particularly useful to finish 'obtain'
  3396 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3397 without referring to the original premise "!!x. P x ==> thesis" in the
  3398 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3399 more permissive.
  3400 
  3401 * Isar: implicit use of prems from the Isar proof context is
  3402 considered a legacy feature.  Common applications like ``have A .''
  3403 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3404 referencing facts explicitly here improves readability and
  3405 maintainability of proof texts.
  3406 
  3407 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3408 the obtained context from the course of reasoning!  For example:
  3409 
  3410   assume "EX x y. A x & B y"   -- "any previous fact"
  3411   then guess x and y by clarify
  3412 
  3413 This technique is potentially adventurous, depending on the facts and
  3414 proof tools being involved here.
  3415 
  3416 * Isar: known facts from the proof context may be specified as literal
  3417 propositions, using ASCII back-quote syntax.  This works wherever
  3418 named facts used to be allowed so far, in proof commands, proof
  3419 methods, attributes etc.  Literal facts are retrieved from the context
  3420 according to unification of type and term parameters.  For example,
  3421 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3422 theorems in the current context, then these are valid literal facts:
  3423 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3424 
  3425 There is also a proof method "fact" which does the same composition
  3426 for explicit goal states, e.g. the following proof texts coincide with
  3427 certain special cases of literal facts:
  3428 
  3429   have "A" by fact                 ==  note `A`
  3430   have "A ==> B" by fact           ==  note `A ==> B`
  3431   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3432   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3433 
  3434 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3435 outer syntax.  Thus symbolic identifiers may be used without
  3436 additional white space in declarations like this: ``assume *: A''.
  3437 
  3438 * Isar: 'print_facts' prints all local facts of the current context,
  3439 both named and unnamed ones.
  3440 
  3441 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3442 
  3443   def x == "t" and y == "u"
  3444 
  3445 * Isar: added command 'unfolding', which is structurally similar to
  3446 'using', but affects both the goal state and facts by unfolding given
  3447 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3448 'unfolded' attribute may be replaced by first-class proof text.
  3449 
  3450 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3451 and command 'unfolding' now all support object-level equalities
  3452 (potentially conditional).  The underlying notion of rewrite rule is
  3453 analogous to the 'rule_format' attribute, but *not* that of the
  3454 Simplifier (which is usually more generous).
  3455 
  3456 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3457 premises of a theorem by n. Useful in conjunction with drule.
  3458 
  3459 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3460 method expression within a sandbox consisting of the first N
  3461 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3462 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3463 simplifies all new goals that emerge from applying rule foo to the
  3464 originally first one.
  3465 
  3466 * Isar: schematic goals are no longer restricted to higher-order
  3467 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3468 expected.
  3469 
  3470 * Isar: the conclusion of a long theorem statement is now either
  3471 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3472 (essentially a disjunction of cases with local parameters and
  3473 assumptions).  The latter allows to express general elimination rules
  3474 adequately; in this notation common elimination rules look like this:
  3475 
  3476   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3477     assumes "EX x. P x"
  3478     obtains x where "P x"
  3479 
  3480   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3481     assumes "A & B"
  3482     obtains A and B
  3483 
  3484   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3485     assumes "A | B"
  3486     obtains
  3487       A
  3488     | B
  3489 
  3490 The subsequent classical rules even refer to the formal "thesis"
  3491 explicitly:
  3492 
  3493   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3494     obtains "~ thesis"
  3495 
  3496   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3497     obtains "thesis ==> something"
  3498 
  3499 The actual proof of an 'obtains' statement is analogous to that of the
  3500 Isar proof element 'obtain', only that there may be several cases.
  3501 Optional case names may be specified in parentheses; these will be
  3502 available both in the present proof and as annotations in the
  3503 resulting rule, for later use with the 'cases' method (cf. attribute
  3504 case_names).
  3505 
  3506 * Isar: the assumptions of a long theorem statement are available as
  3507 "assms" fact in the proof context.  This is more appropriate than the
  3508 (historical) "prems", which refers to all assumptions of the current
  3509 context, including those from the target locale, proof body etc.
  3510 
  3511 * Isar: 'print_statement' prints theorems from the current theory or
  3512 proof context in long statement form, according to the syntax of a
  3513 top-level lemma.
  3514 
  3515 * Isar: 'obtain' takes an optional case name for the local context
  3516 introduction rule (default "that").
  3517 
  3518 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3519 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3520 to occur.
  3521 
  3522 * Pure: syntax "CONST name" produces a fully internalized constant
  3523 according to the current context.  This is particularly useful for
  3524 syntax translations that should refer to internal constant
  3525 representations independently of name spaces.
  3526 
  3527 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3528 instead of "FOO ". This allows multiple binder declarations to coexist
  3529 in the same context.  INCOMPATIBILITY.
  3530 
  3531 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3532 primitive that also works in a locale context (both for constants and
  3533 fixed variables). Type declaration and internal syntactic representation
  3534 of given constants retrieved from the context. Likewise, the
  3535 'no_notation' command allows to remove given syntax annotations from the
  3536 current context.
  3537 
  3538 * Isar/locales: new derived specification elements 'axiomatization',
  3539 'definition', 'abbreviation', which support type-inference, admit
  3540 object-level specifications (equality, equivalence).  See also the
  3541 isar-ref manual.  Examples:
  3542 
  3543   axiomatization
  3544     eq  (infix "===" 50) where
  3545     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3546 
  3547   definition "f x y = x + y + 1"
  3548   definition g where "g x = f x x"
  3549 
  3550   abbreviation
  3551     neq  (infix "=!=" 50) where
  3552     "x =!= y == ~ (x === y)"
  3553 
  3554 These specifications may be also used in a locale context.  Then the
  3555 constants being introduced depend on certain fixed parameters, and the
  3556 constant name is qualified by the locale base name.  An internal
  3557 abbreviation takes care for convenient input and output, making the
  3558 parameters implicit and using the original short name.  See also
  3559 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3560 entities from a monomorphic theory.
  3561 
  3562 Presently, abbreviations are only available 'in' a target locale, but
  3563 not inherited by general import expressions.  Also note that
  3564 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3565 'translations' in common applications.  The "no_abbrevs" print mode
  3566 prevents folding of abbreviations in term output.
  3567 
  3568 Concrete syntax is attached to specified constants in internal form,
  3569 independently of name spaces.  The parse tree representation is
  3570 slightly different -- use 'notation' instead of raw 'syntax', and
  3571 'translations' with explicit "CONST" markup to accommodate this.
  3572 
  3573 * Pure/Isar: unified syntax for new-style specification mechanisms
  3574 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3575 full type inference and dummy patterns ("_").  For example:
  3576 
  3577   definition "K x _ = x"
  3578 
  3579   inductive conj for A B
  3580   where "A ==> B ==> conj A B"
  3581 
  3582 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3583 the current context.  Print mode "no_abbrevs" prevents inversion of
  3584 abbreviations on output.
  3585 
  3586 * Isar/locales: improved parameter handling: use of locales "var" and
  3587 "struct" no longer necessary; - parameter renamings are no longer
  3588 required to be injective.  For example, this allows to define
  3589 endomorphisms as locale endom = homom mult mult h.
  3590 
  3591 * Isar/locales: changed the way locales with predicates are defined.
  3592 Instead of accumulating the specification, the imported expression is
  3593 now an interpretation.  INCOMPATIBILITY: different normal form of
  3594 locale expressions.  In particular, in interpretations of locales with
  3595 predicates, goals repesenting already interpreted fragments are not
  3596 removed automatically.  Use methods `intro_locales' and
  3597 `unfold_locales'; see below.
  3598 
  3599 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3600 provide backward reasoning on locales predicates.  The methods are
  3601 aware of interpretations and discharge corresponding goals.
  3602 `intro_locales' is less aggressive then `unfold_locales' and does not
  3603 unfold predicates to assumptions.
  3604 
  3605 * Isar/locales: the order in which locale fragments are accumulated
  3606 has changed.  This enables to override declarations from fragments due
  3607 to interpretations -- for example, unwanted simp rules.
  3608 
  3609 * Isar/locales: interpretation in theories and proof contexts has been
  3610 extended.  One may now specify (and prove) equations, which are
  3611 unfolded in interpreted theorems.  This is useful for replacing
  3612 defined concepts (constants depending on locale parameters) by
  3613 concepts already existing in the target context.  Example:
  3614 
  3615   interpretation partial_order ["op <= :: [int, int] => bool"]
  3616     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3617 
  3618 Typically, the constant `partial_order.less' is created by a
  3619 definition specification element in the context of locale
  3620 partial_order.
  3621 
  3622 * Method "induct": improved internal context management to support
  3623 local fixes and defines on-the-fly. Thus explicit meta-level
  3624 connectives !!  and ==> are rarely required anymore in inductive goals
  3625 (using object-logic connectives for this purpose has been long
  3626 obsolete anyway). Common proof patterns are explained in
  3627 src/HOL/Induct/Common_Patterns.thy, see also
  3628 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3629 examples.
  3630 
  3631 * Method "induct": improved handling of simultaneous goals. Instead of
  3632 introducing object-level conjunction, the statement is now split into
  3633 several conclusions, while the corresponding symbolic cases are nested
  3634 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3635 see src/HOL/Induct/Common_Patterns.thy, for example.
  3636 
  3637 * Method "induct": mutual induction rules are now specified as a list
  3638 of rule sharing the same induction cases. HOL packages usually provide
  3639 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3640 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3641 mutual induction rules differently, i.e. like this:
  3642 
  3643   (induct rule: foo_bar.inducts)
  3644   (induct set: foo bar)
  3645   (induct pred: foo bar)
  3646   (induct type: foo bar)
  3647 
  3648 The ML function ProjectRule.projections turns old-style rules into the
  3649 new format.
  3650 
  3651 * Method "coinduct": dual of induction, see
  3652 src/HOL/Library/Coinductive_List.thy for various examples.
  3653 
  3654 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3655 considered a legacy feature.
  3656 
  3657 * Attribute "symmetric" produces result with standardized schematic
  3658 variables (index 0).  Potential INCOMPATIBILITY.
  3659 
  3660 * Simplifier: by default the simplifier trace only shows top level
  3661 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3662 default. Thus there is less danger of being flooded by the trace. The
  3663 trace indicates where parts have been suppressed.
  3664   
  3665 * Provers/classical: removed obsolete classical version of elim_format
  3666 attribute; classical elim/dest rules are now treated uniformly when
  3667 manipulating the claset.
  3668 
  3669 * Provers/classical: stricter checks to ensure that supplied intro,
  3670 dest and elim rules are well-formed; dest and elim rules must have at
  3671 least one premise.
  3672 
  3673 * Provers/classical: attributes dest/elim/intro take an optional
  3674 weight argument for the rule (just as the Pure versions).  Weights are
  3675 ignored by automated tools, but determine the search order of single
  3676 rule steps.
  3677 
  3678 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3679 where the body does not mention the bound variable.  Note that dummy
  3680 patterns implicitly depend on their context of bounds, which makes
  3681 "{_. _}" match any set comprehension as expected.  Potential
  3682 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3683 constant "_idtdummy" in the binding position.
  3684 
  3685 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3686 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3687 for example "A -> B" => "Pi A (%_. B)".
  3688 
  3689 * Pure: 'class_deps' command visualizes the subclass relation, using
  3690 the graph browser tool.
  3691 
  3692 * Pure: 'print_theory' now suppresses certain internal declarations by
  3693 default; use '!' option for full details.
  3694 
  3695 
  3696 *** HOL ***
  3697 
  3698 * Method "metis" proves goals by applying the Metis general-purpose
  3699 resolution prover (see also http://gilith.com/software/metis/).
  3700 Examples are in the directory MetisExamples.  WARNING: the
  3701 Isabelle/HOL-Metis integration does not yet work properly with
  3702 multi-threading.
  3703   
  3704 * Command 'sledgehammer' invokes external automatic theorem provers as
  3705 background processes.  It generates calls to the "metis" method if
  3706 successful. These can be pasted into the proof.  Users do not have to
  3707 wait for the automatic provers to return.  WARNING: does not really
  3708 work with multi-threading.
  3709 
  3710 * New "auto_quickcheck" feature tests outermost goal statements for
  3711 potential counter-examples.  Controlled by ML references
  3712 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3713 5000 milliseconds).  Fails silently if statements is outside of
  3714 executable fragment, or any other codgenerator problem occurs.
  3715 
  3716 * New constant "undefined" with axiom "undefined x = undefined".
  3717 
  3718 * Added class "HOL.eq", allowing for code generation with polymorphic
  3719 equality.
  3720 
  3721 * Some renaming of class constants due to canonical name prefixing in
  3722 the new 'class' package:
  3723 
  3724     HOL.abs ~> HOL.abs_class.abs
  3725     HOL.divide ~> HOL.divide_class.divide
  3726     0 ~> HOL.zero_class.zero
  3727     1 ~> HOL.one_class.one
  3728     op + ~> HOL.plus_class.plus
  3729     op - ~> HOL.minus_class.minus
  3730     uminus ~> HOL.minus_class.uminus
  3731     op * ~> HOL.times_class.times
  3732     op < ~> HOL.ord_class.less
  3733     op <= > HOL.ord_class.less_eq
  3734     Nat.power ~> Power.power_class.power
  3735     Nat.size ~> Nat.size_class.size
  3736     Numeral.number_of ~> Numeral.number_class.number_of
  3737     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3738     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3739     Orderings.min ~> Orderings.ord_class.min
  3740     Orderings.max ~> Orderings.ord_class.max
  3741     Divides.op div ~> Divides.div_class.div
  3742     Divides.op mod ~> Divides.div_class.mod
  3743     Divides.op dvd ~> Divides.div_class.dvd
  3744 
  3745 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3746 
  3747 a) User-defined constants using any of the names "plus", "minus",
  3748 "times", "less" or "less_eq". The standard syntax translations for
  3749 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3750 names.
  3751 
  3752 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3753 INCOMPATIBILITY: use more specific names.
  3754 
  3755 c) Permutative equations (e.g. "a + b = b + a")
  3756 Since the change of names also changes the order of terms, permutative
  3757 rewrite rules may get applied in a different order. Experience shows
  3758 that this is rarely the case (only two adaptions in the whole Isabelle
  3759 distribution).  INCOMPATIBILITY: rewrite proofs
  3760 
  3761 d) ML code directly refering to constant names
  3762 This in general only affects hand-written proof tactics, simprocs and
  3763 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3764 Consider using @{const_name} antiquotation.
  3765 
  3766 * New class "default" with associated constant "default".
  3767 
  3768 * Function "sgn" is now overloaded and available on int, real, complex
  3769 (and other numeric types), using class "sgn".  Two possible defs of
  3770 sgn are given as equational assumptions in the classes sgn_if and
  3771 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3772 INCOMPATIBILITY.
  3773 
  3774 * Locale "partial_order" now unified with class "order" (cf. theory
  3775 Orderings), added parameter "less".  INCOMPATIBILITY.
  3776 
  3777 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3778 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3779 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3780 
  3781 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3782 changed order of proof goals in instance proofs.
  3783 
  3784 * The transitivity reasoner for partial and linear orders is set up
  3785 for classes "order" and "linorder".  Instances of the reasoner are available
  3786 in all contexts importing or interpreting the corresponding locales.
  3787 Method "order" invokes the reasoner separately; the reasoner
  3788 is also integrated with the Simplifier as a solver.  Diagnostic
  3789 command 'print_orders' shows the available instances of the reasoner
  3790 in the current context.
  3791 
  3792 * Localized monotonicity predicate in theory "Orderings"; integrated
  3793 lemmas max_of_mono and min_of_mono with this predicate.
  3794 INCOMPATIBILITY.
  3795 
  3796 * Formulation of theorem "dense" changed slightly due to integration
  3797 with new class dense_linear_order.
  3798 
  3799 * Uniform lattice theory development in HOL.
  3800 
  3801     constants "meet" and "join" now named "inf" and "sup"
  3802     constant "Meet" now named "Inf"
  3803 
  3804     classes "meet_semilorder" and "join_semilorder" now named
  3805       "lower_semilattice" and "upper_semilattice"
  3806     class "lorder" now named "lattice"
  3807     class "comp_lat" now named "complete_lattice"
  3808 
  3809     Instantiation of lattice classes allows explicit definitions
  3810     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3811 
  3812   INCOMPATIBILITY.  Theorem renames:
  3813 
  3814     meet_left_le            ~> inf_le1
  3815     meet_right_le           ~> inf_le2
  3816     join_left_le            ~> sup_ge1
  3817     join_right_le           ~> sup_ge2
  3818     meet_join_le            ~> inf_sup_ord
  3819     le_meetI                ~> le_infI
  3820     join_leI                ~> le_supI
  3821     le_meet                 ~> le_inf_iff
  3822     le_join                 ~> ge_sup_conv
  3823     meet_idempotent         ~> inf_idem
  3824     join_idempotent         ~> sup_idem
  3825     meet_comm               ~> inf_commute
  3826     join_comm               ~> sup_commute
  3827     meet_leI1               ~> le_infI1
  3828     meet_leI2               ~> le_infI2
  3829     le_joinI1               ~> le_supI1
  3830     le_joinI2               ~> le_supI2
  3831     meet_assoc              ~> inf_assoc
  3832     join_assoc              ~> sup_assoc
  3833     meet_left_comm          ~> inf_left_commute
  3834     meet_left_idempotent    ~> inf_left_idem
  3835     join_left_comm          ~> sup_left_commute
  3836     join_left_idempotent    ~> sup_left_idem
  3837     meet_aci                ~> inf_aci
  3838     join_aci                ~> sup_aci
  3839     le_def_meet             ~> le_iff_inf
  3840     le_def_join             ~> le_iff_sup
  3841     join_absorp2            ~> sup_absorb2
  3842     join_absorp1            ~> sup_absorb1
  3843     meet_absorp1            ~> inf_absorb1
  3844     meet_absorp2            ~> inf_absorb2
  3845     meet_join_absorp        ~> inf_sup_absorb
  3846     join_meet_absorp        ~> sup_inf_absorb
  3847     distrib_join_le         ~> distrib_sup_le
  3848     distrib_meet_le         ~> distrib_inf_le
  3849 
  3850     add_meet_distrib_left   ~> add_inf_distrib_left
  3851     add_join_distrib_left   ~> add_sup_distrib_left
  3852     is_join_neg_meet        ~> is_join_neg_inf
  3853     is_meet_neg_join        ~> is_meet_neg_sup
  3854     add_meet_distrib_right  ~> add_inf_distrib_right
  3855     add_join_distrib_right  ~> add_sup_distrib_right
  3856     add_meet_join_distribs  ~> add_sup_inf_distribs
  3857     join_eq_neg_meet        ~> sup_eq_neg_inf
  3858     meet_eq_neg_join        ~> inf_eq_neg_sup
  3859     add_eq_meet_join        ~> add_eq_inf_sup
  3860     meet_0_imp_0            ~> inf_0_imp_0
  3861     join_0_imp_0            ~> sup_0_imp_0
  3862     meet_0_eq_0             ~> inf_0_eq_0
  3863     join_0_eq_0             ~> sup_0_eq_0
  3864     neg_meet_eq_join        ~> neg_inf_eq_sup
  3865     neg_join_eq_meet        ~> neg_sup_eq_inf
  3866     join_eq_if              ~> sup_eq_if
  3867 
  3868     mono_meet               ~> mono_inf
  3869     mono_join               ~> mono_sup
  3870     meet_bool_eq            ~> inf_bool_eq
  3871     join_bool_eq            ~> sup_bool_eq
  3872     meet_fun_eq             ~> inf_fun_eq
  3873     join_fun_eq             ~> sup_fun_eq
  3874     meet_set_eq             ~> inf_set_eq
  3875     join_set_eq             ~> sup_set_eq
  3876     meet1_iff               ~> inf1_iff
  3877     meet2_iff               ~> inf2_iff
  3878     meet1I                  ~> inf1I
  3879     meet2I                  ~> inf2I
  3880     meet1D1                 ~> inf1D1
  3881     meet2D1                 ~> inf2D1
  3882     meet1D2                 ~> inf1D2
  3883     meet2D2                 ~> inf2D2
  3884     meet1E                  ~> inf1E
  3885     meet2E                  ~> inf2E
  3886     join1_iff               ~> sup1_iff
  3887     join2_iff               ~> sup2_iff
  3888     join1I1                 ~> sup1I1
  3889     join2I1                 ~> sup2I1
  3890     join1I1                 ~> sup1I1
  3891     join2I2                 ~> sup1I2
  3892     join1CI                 ~> sup1CI
  3893     join2CI                 ~> sup2CI
  3894     join1E                  ~> sup1E
  3895     join2E                  ~> sup2E
  3896 
  3897     is_meet_Meet            ~> is_meet_Inf
  3898     Meet_bool_def           ~> Inf_bool_def
  3899     Meet_fun_def            ~> Inf_fun_def
  3900     Meet_greatest           ~> Inf_greatest
  3901     Meet_lower              ~> Inf_lower
  3902     Meet_set_def            ~> Inf_set_def
  3903 
  3904     Sup_def                 ~> Sup_Inf
  3905     Sup_bool_eq             ~> Sup_bool_def
  3906     Sup_fun_eq              ~> Sup_fun_def
  3907     Sup_set_eq              ~> Sup_set_def
  3908 
  3909     listsp_meetI            ~> listsp_infI
  3910     listsp_meet_eq          ~> listsp_inf_eq
  3911 
  3912     meet_min                ~> inf_min
  3913     join_max                ~> sup_max
  3914 
  3915 * Added syntactic class "size"; overloaded constant "size" now has
  3916 type "'a::size ==> bool"
  3917 
  3918 * Internal reorganisation of `size' of datatypes: size theorems
  3919 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3920 simplification rules by default!); theorems "prod.size" now named
  3921 "*.size".
  3922 
  3923 * Class "div" now inherits from class "times" rather than "type".
  3924 INCOMPATIBILITY.
  3925 
  3926 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3927 Linorder etc.  have disappeared; operations defined in terms of
  3928 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3929 
  3930 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3931 
  3932 * HOL-Word: New extensive library and type for generic, fixed size
  3933 machine words, with arithemtic, bit-wise, shifting and rotating
  3934 operations, reflection into int, nat, and bool lists, automation for
  3935 linear arithmetic (by automatic reflection into nat or int), including
  3936 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3937 arithmetic type classes, supporting automatic simplification of
  3938 numerals on all operations.
  3939 
  3940 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3941 
  3942 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3943 
  3944 * Code generator library theories:
  3945   - Code_Integer represents HOL integers by big integer literals in target
  3946     languages.
  3947   - Code_Char represents HOL characters by character literals in target
  3948     languages.
  3949   - Code_Char_chr like Code_Char, but also offers treatment of character
  3950     codes; includes Code_Integer.
  3951   - Executable_Set allows to generate code for finite sets using lists.
  3952   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3953     denominator).
  3954   - Executable_Real implements a subset of real numbers, namly those
  3955     representable by rational numbers.
  3956   - Efficient_Nat implements natural numbers by integers, which in general will
  3957     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3958     includes Code_Integer.
  3959   - Code_Index provides an additional datatype index which is mapped to
  3960     target-language built-in integers.
  3961   - Code_Message provides an additional datatype message_string which is isomorphic to
  3962     strings; messages are mapped to target-language strings.
  3963 
  3964 * New package for inductive predicates
  3965 
  3966   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3967 
  3968     inductive
  3969       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3970       for z_1 :: U_1 and ... and z_n :: U_m
  3971     where
  3972       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3973     | ...
  3974 
  3975   with full support for type-inference, rather than
  3976 
  3977     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3978 
  3979     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3980     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3981 
  3982     inductive "s z_1 ... z_m"
  3983     intros
  3984       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3985       ...
  3986 
  3987   For backward compatibility, there is a wrapper allowing inductive
  3988   sets to be defined with the new package via
  3989 
  3990     inductive_set
  3991       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3992       for z_1 :: U_1 and ... and z_n :: U_m
  3993     where
  3994       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3995     | ...
  3996 
  3997   or
  3998 
  3999     inductive_set
  4000       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4001       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4002       for z_1 :: U_1 and ... and z_n :: U_m
  4003     where
  4004       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4005     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4006     | ...
  4007 
  4008   if the additional syntax "p ..." is required.
  4009 
  4010   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4011   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4012 
  4013   INCOMPATIBILITIES:
  4014 
  4015   - Since declaration and definition of inductive sets or predicates
  4016     is no longer separated, abbreviations involving the newly
  4017     introduced sets or predicates must be specified together with the
  4018     introduction rules after the 'where' keyword (see above), rather
  4019     than before the actual inductive definition.
  4020 
  4021   - The variables in induction and elimination rules are now
  4022     quantified in the order of their occurrence in the introduction
  4023     rules, rather than in alphabetical order. Since this may break
  4024     some proofs, these proofs either have to be repaired, e.g. by
  4025     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4026     statements of the form
  4027 
  4028       case (rule_i a_i_1 ... a_i_{k_i})
  4029 
  4030     or the old order of quantification has to be restored by explicitly adding
  4031     meta-level quantifiers in the introduction rules, i.e.
  4032 
  4033       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4034 
  4035   - The format of the elimination rules is now
  4036 
  4037       p z_1 ... z_m x_1 ... x_n ==>
  4038         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4039         ==> ... ==> P
  4040 
  4041     for predicates and
  4042 
  4043       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4044         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4045         ==> ... ==> P
  4046 
  4047     for sets rather than
  4048 
  4049       x : s z_1 ... z_m ==>
  4050         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4051         ==> ... ==> P
  4052 
  4053     This may require terms in goals to be expanded to n-tuples
  4054     (e.g. using case_tac or simplification with the split_paired_all
  4055     rule) before the above elimination rule is applicable.
  4056 
  4057   - The elimination or case analysis rules for (mutually) inductive
  4058     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4059     list of rules "p_1_..._p_k.elims" is no longer available.
  4060 
  4061 * New package "function"/"fun" for general recursive functions,
  4062 supporting mutual and nested recursion, definitions in local contexts,
  4063 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4064 for small examples, and the separate tutorial on the function
  4065 package. The old recdef "package" is still available as before, but
  4066 users are encouraged to use the new package.
  4067 
  4068 * Method "lexicographic_order" automatically synthesizes termination
  4069 relations as lexicographic combinations of size measures. 
  4070 
  4071 * Case-expressions allow arbitrary constructor-patterns (including
  4072 "_") and take their order into account, like in functional
  4073 programming.  Internally, this is translated into nested
  4074 case-expressions; missing cases are added and mapped to the predefined
  4075 constant "undefined". In complicated cases printing may no longer show
  4076 the original input but the internal form. Lambda-abstractions allow
  4077 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4078 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4079 variable.
  4080 
  4081 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4082 is an abbreviation for "of_nat :: nat => int". The simplification
  4083 rules for "of_nat" have been changed to work like "int" did
  4084 previously.  Potential INCOMPATIBILITY:
  4085   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4086   - of_nat_diff and of_nat_mult are no longer default simp rules
  4087 
  4088 * Method "algebra" solves polynomial equations over (semi)rings using
  4089 Groebner bases. The (semi)ring structure is defined by locales and the
  4090 tool setup depends on that generic context. Installing the method for
  4091 a specific type involves instantiating the locale and possibly adding
  4092 declarations for computation on the coefficients.  The method is
  4093 already instantiated for natural numbers and for the axiomatic class
  4094 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4095 CALCULEMUS 2007 for the general principles underlying this
  4096 architecture of context-aware proof-tools.
  4097 
  4098 * Method "ferrack" implements quantifier elimination over
  4099 special-purpose dense linear orders using locales (analogous to
  4100 "algebra"). The method is already installed for class
  4101 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4102 rat, etc.
  4103 
  4104 * Former constant "List.op @" now named "List.append".  Use ML
  4105 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4106 circumvent possible incompatibilities when working on ML level.
  4107 
  4108 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4109 
  4110 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4111 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4112 
  4113 * New syntax for Haskell-like list comprehension (input only), eg.
  4114 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4115 
  4116 * The special syntax for function "filter" has changed from [x :
  4117 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4118 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4119 
  4120 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4121 defined on nat only, as an abbreviation for [a..<Suc b]
  4122 INCOMPATIBILITY.
  4123 
  4124 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4125 
  4126 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4127 
  4128 * New lemma collection field_simps (an extension of ring_simps) for
  4129 manipulating (in)equations involving division. Multiplies with all
  4130 denominators that can be proved to be non-zero (in equations) or
  4131 positive/negative (in inequations).
  4132 
  4133 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4134 have been improved and renamed to ring_simps, group_simps and
  4135 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4136 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4137 
  4138 * Theory Library/Commutative_Ring: switched from recdef to function
  4139 package; constants add, mul, pow now curried.  Infix syntax for
  4140 algebraic operations.
  4141 
  4142 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4143 INCOMPATIBILITY.
  4144 
  4145 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4146 INCOMPATIBILITY.
  4147 
  4148 * HOL/records: generalised field-update to take a function on the
  4149 field rather than the new value: r(|A := x|) is translated to A_update
  4150 (K x) r The K-combinator that is internally used is called K_record.
  4151 INCOMPATIBILITY: Usage of the plain update functions has to be
  4152 adapted.
  4153  
  4154 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4155 * x = 0, which are required for a semiring.  Richer structures do not
  4156 inherit from semiring_0 anymore, because this property is a theorem
  4157 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4158 there is more to prove, but this is mostly trivial.
  4159 
  4160 * Class "recpower" is generalized to arbitrary monoids, not just
  4161 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4162 commutativity or semiring properties additionally.
  4163 
  4164 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4165 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4166 better use 'abbreviation'.
  4167 
  4168 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4169 
  4170 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4171 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4172 significant changes for setting up numeral syntax for types:
  4173   - New constants Numeral.pred and Numeral.succ instead
  4174       of former Numeral.bin_pred and Numeral.bin_succ.
  4175   - Use integer operations instead of bin_add, bin_mult and so on.
  4176   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4177   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4178 
  4179 See src/HOL/Integ/IntArith.thy for an example setup.
  4180 
  4181 * Command 'normal_form' computes the normal form of a term that may
  4182 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4183 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4184 heavy-duty computations because the functions are compiled to ML
  4185 first.  Correspondingly, a method "normalization" is provided.  See
  4186 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4187 
  4188 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4189 25 like -->); output depends on the "iff" print_mode, the default is
  4190 "A = B" (with priority 50).
  4191 
  4192 * Relations less (<) and less_eq (<=) are also available on type bool.
  4193 Modified syntax to disallow nesting without explicit parentheses,
  4194 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4195 INCOMPATIBILITY.
  4196 
  4197 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4198 
  4199 * Relation composition operator "op O" now has precedence 75 and binds
  4200 stronger than union and intersection. INCOMPATIBILITY.
  4201 
  4202 * The old set interval syntax "{m..n(}" (and relatives) has been
  4203 removed.  Use "{m..<n}" (and relatives) instead.
  4204 
  4205 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4206 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4207 ``declare [[simproc del: neq]]''.
  4208 
  4209 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4210 True/False.
  4211 
  4212 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4213 
  4214 * Theorem setsum_mult renamed to setsum_right_distrib.
  4215 
  4216 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4217 ``rule'' method.
  4218 
  4219 * Reimplemented methods "sat" and "satx", with several improvements:
  4220 goals no longer need to be stated as "<prems> ==> False", equivalences
  4221 (i.e. "=" on type bool) are handled, variable names of the form
  4222 "lit_<n>" are no longer reserved, significant speedup.
  4223 
  4224 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4225 zChaff is still supported as well.
  4226 
  4227 * 'inductive' and 'datatype': provide projections of mutual rules,
  4228 bundled as foo_bar.inducts;
  4229 
  4230 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4231 Library.
  4232 
  4233 * Library: moved theory Accessible_Part to main HOL.
  4234 
  4235 * Library: added theory Coinductive_List of potentially infinite lists
  4236 as greatest fixed-point.
  4237 
  4238 * Library: added theory AssocList which implements (finite) maps as
  4239 association lists.
  4240 
  4241 * Method "evaluation" solves goals (i.e. a boolean expression)
  4242 efficiently by compiling it to ML.  The goal is "proved" (via an
  4243 oracle) if it evaluates to True.
  4244 
  4245 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4246 also when invoked by the simplifier.  This results in the Simplifier
  4247 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4248 Configuration option fast_arith_split_limit=0 recovers the old
  4249 behavior.
  4250 
  4251 * Support for hex (0x20) and binary (0b1001) numerals.
  4252 
  4253 * New method: reify eqs (t), where eqs are equations for an
  4254 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4255 parameter, computes a term s::'b and a list xs::'a list and proves the
  4256 theorem I xs s = t. This is also known as reification or quoting. The
  4257 resulting theorem is applied to the subgoal to substitute t with I xs
  4258 s.  If t is omitted, the subgoal itself is reified.
  4259 
  4260 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4261 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4262 where f is supposed to be a computable function (in the sense of code
  4263 generattion). The method uses reify to compute s and xs as above then
  4264 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4265 r and finally gets the theorem t = r, which is again applied to the
  4266 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4267 
  4268 * Reflection: Automatic reification now handels binding, an example is
  4269 available in src/HOL/ex/ReflectionEx.thy
  4270 
  4271 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4272 command 'statespace' that is similar to 'record', but introduces an
  4273 abstract specification based on the locale infrastructure instead of
  4274 HOL types.  This leads to extra flexibility in composing state spaces,
  4275 in particular multiple inheritance and renaming of components.
  4276 
  4277 
  4278 *** HOL-Complex ***
  4279 
  4280 * Hyperreal: Functions root and sqrt are now defined on negative real
  4281 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4282 Nonnegativity side conditions have been removed from many lemmas, so
  4283 that more subgoals may now be solved by simplification; potential
  4284 INCOMPATIBILITY.
  4285 
  4286 * Real: new type classes formalize real normed vector spaces and
  4287 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4288 and norm :: 'a => real.
  4289 
  4290 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4291 reals into other types. The overloaded constant Reals :: 'a set is now
  4292 defined as range of_real; potential INCOMPATIBILITY.
  4293 
  4294 * Real: proper support for ML code generation, including 'quickcheck'.
  4295 Reals are implemented as arbitrary precision rationals.
  4296 
  4297 * Hyperreal: Several constants that previously worked only for the
  4298 reals have been generalized, so they now work over arbitrary vector
  4299 spaces. Type annotations may need to be added in some cases; potential
  4300 INCOMPATIBILITY.
  4301 
  4302   Infinitesimal  :: ('a::real_normed_vector) star set
  4303   HFinite        :: ('a::real_normed_vector) star set
  4304   HInfinite      :: ('a::real_normed_vector) star set
  4305   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4306   monad          :: ('a::real_normed_vector) star => 'a star set
  4307   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4308   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4309   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4310   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4311   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4312   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4313   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4314   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4315   sgn            :: 'a::real_normed_vector => 'a
  4316   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4317 
  4318 * Complex: Some complex-specific constants are now abbreviations for
  4319 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4320 hnorm.  Other constants have been entirely removed in favor of the
  4321 polymorphic versions (INCOMPATIBILITY):
  4322 
  4323   approx        <-- capprox
  4324   HFinite       <-- CFinite
  4325   HInfinite     <-- CInfinite
  4326   Infinitesimal <-- CInfinitesimal
  4327   monad         <-- cmonad
  4328   galaxy        <-- cgalaxy
  4329   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4330   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4331   (ns)deriv     <-- (ns)cderiv
  4332 
  4333 
  4334 *** HOL-Algebra ***
  4335 
  4336 * Formalisation of ideals and the quotient construction over rings.
  4337 
  4338 * Order and lattice theory no longer based on records.
  4339 INCOMPATIBILITY.
  4340 
  4341 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4342 greatest_closed.  INCOMPATIBILITY.
  4343 
  4344 * Method algebra is now set up via an attribute.  For examples see
  4345 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4346 of algebraic structures.
  4347 
  4348 * Renamed theory CRing to Ring.
  4349 
  4350 
  4351 *** HOL-Nominal ***
  4352 
  4353 * Substantial, yet incomplete support for nominal datatypes (binding
  4354 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4355 src/HOL/Nominal/Examples.  Prospective users should consult
  4356 http://isabelle.in.tum.de/nominal/
  4357 
  4358 
  4359 *** ML ***
  4360 
  4361 * ML basics: just one true type int, which coincides with IntInf.int
  4362 (even on SML/NJ).
  4363 
  4364 * ML within Isar: antiquotations allow to embed statically-checked
  4365 formal entities in the source, referring to the context available at
  4366 compile-time.  For example:
  4367 
  4368 ML {* @{sort "{zero,one}"} *}
  4369 ML {* @{typ "'a => 'b"} *}
  4370 ML {* @{term "%x. x"} *}
  4371 ML {* @{prop "x == y"} *}
  4372 ML {* @{ctyp "'a => 'b"} *}
  4373 ML {* @{cterm "%x. x"} *}
  4374 ML {* @{cprop "x == y"} *}
  4375 ML {* @{thm asm_rl} *}
  4376 ML {* @{thms asm_rl} *}
  4377 ML {* @{type_name c} *}
  4378 ML {* @{type_syntax c} *}
  4379 ML {* @{const_name c} *}
  4380 ML {* @{const_syntax c} *}
  4381 ML {* @{context} *}
  4382 ML {* @{theory} *}
  4383 ML {* @{theory Pure} *}
  4384 ML {* @{theory_ref} *}
  4385 ML {* @{theory_ref Pure} *}
  4386 ML {* @{simpset} *}
  4387 ML {* @{claset} *}
  4388 ML {* @{clasimpset} *}
  4389 
  4390 The same works for sources being ``used'' within an Isar context.
  4391 
  4392 * ML in Isar: improved error reporting; extra verbosity with
  4393 ML_Context.trace enabled.
  4394 
  4395 * Pure/General/table.ML: the join operations now works via exceptions
  4396 DUP/SAME instead of type option. This is simpler in simple cases, and
  4397 admits slightly more efficient complex applications.
  4398 
  4399 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4400 use Context.generic instead of just theory.
  4401 
  4402 * Pure: datatype Context.generic joins theory/Proof.context and
  4403 provides some facilities for code that works in either kind of
  4404 context, notably GenericDataFun for uniform theory and proof data.
  4405 
  4406 * Pure: simplified internal attribute type, which is now always
  4407 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4408 local (Proof.context) attributes have been discontinued, while
  4409 minimizing code duplication. Thm.rule_attribute and
  4410 Thm.declaration_attribute build canonical attributes; see also structure
  4411 Context for further operations on Context.generic, notably
  4412 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4413 declarations and definitions.
  4414 
  4415 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4416 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4417 init only required for impure data. INCOMPATIBILITY: empty really need
  4418 to be empty (no dependencies on theory content!)
  4419 
  4420 * Pure/kernel: consts certification ignores sort constraints given in
  4421 signature declarations. (This information is not relevant to the
  4422 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4423 potential INCOMPATIBILITY.
  4424 
  4425 * Pure: axiomatic type classes are now purely definitional, with
  4426 explicit proofs of class axioms and super class relations performed
  4427 internally. See Pure/axclass.ML for the main internal interfaces --
  4428 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4429 AxClass.axiomatize_class/classrel/arity supersede
  4430 Sign.add_classes/classrel/arities.
  4431 
  4432 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4433 global/local versions on theory vs. Proof.context have been
  4434 discontinued; Attrib.syntax and Method.syntax have been adapted
  4435 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4436 attributes, methods, etc.
  4437 
  4438 * Pure: several functions of signature "... -> theory -> theory * ..."
  4439 have been reoriented to "... -> theory -> ... * theory" in order to
  4440 allow natural usage in combination with the ||>, ||>>, |-> and
  4441 fold_map combinators.
  4442 
  4443 * Pure: official theorem names (closed derivations) and additional
  4444 comments (tags) are now strictly separate.  Name hints -- which are
  4445 maintained as tags -- may be attached any time without affecting the
  4446 derivation.
  4447 
  4448 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4449 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4450 achieve the old behaviour.
  4451 
  4452 * Pure: the "Goal" constant is now called "prop", supporting a
  4453 slightly more general idea of ``protecting'' meta-level rule
  4454 statements.
  4455 
  4456 * Pure: Logic.(un)varify only works in a global context, which is now
  4457 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4458 Logic.legacy_(un)varify as temporary workaround.
  4459 
  4460 * Pure: structure Name provides scalable operations for generating
  4461 internal variable names, notably Name.variants etc.  This replaces
  4462 some popular functions from term.ML:
  4463 
  4464   Term.variant		->  Name.variant
  4465   Term.variantlist	->  Name.variant_list
  4466   Term.invent_names	->  Name.invent_list
  4467 
  4468 Note that low-level renaming rarely occurs in new code -- operations
  4469 from structure Variable are used instead (see below).
  4470 
  4471 * Pure: structure Variable provides fundamental operations for proper
  4472 treatment of fixed/schematic variables in a context.  For example,
  4473 Variable.import introduces fixes for schematics of given facts and
  4474 Variable.export reverses the effect (up to renaming) -- this replaces
  4475 various freeze_thaw operations.
  4476 
  4477 * Pure: structure Goal provides simple interfaces for
  4478 init/conclude/finish and tactical prove operations (replacing former
  4479 Tactic.prove).  Goal.prove is the canonical way to prove results
  4480 within a given context; Goal.prove_global is a degraded version for
  4481 theory level goals, including a global Drule.standard.  Note that
  4482 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4483 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4484 in a locale context).
  4485 
  4486 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4487 and type checking (Syntax.check_term etc.), with common combinations
  4488 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4489 which are considered legacy and await removal.
  4490 
  4491 * Pure/Syntax: generic interfaces for type unchecking
  4492 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4493 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4494 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4495 available for convenience, but refer to the very same operations using
  4496 a mere theory instead of a full context.
  4497 
  4498 * Isar: simplified treatment of user-level errors, using exception
  4499 ERROR of string uniformly.  Function error now merely raises ERROR,
  4500 without any side effect on output channels.  The Isar toplevel takes
  4501 care of proper display of ERROR exceptions.  ML code may use plain
  4502 handle/can/try; cat_error may be used to concatenate errors like this:
  4503 
  4504   ... handle ERROR msg => cat_error msg "..."
  4505 
  4506 Toplevel ML code (run directly or through the Isar toplevel) may be
  4507 embedded into the Isar toplevel with exception display/debug like
  4508 this:
  4509 
  4510   Isar.toplevel (fn () => ...)
  4511 
  4512 INCOMPATIBILITY, removed special transform_error facilities, removed
  4513 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4514 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4515 -- use plain ERROR instead.
  4516 
  4517 * Isar: theory setup now has type (theory -> theory), instead of a
  4518 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4519 
  4520 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4521 ProofContext.debug/verbose flags.
  4522 
  4523 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4524 theory before entering a proof state.  Transactions now always see a
  4525 quasi-functional intermediate checkpoint, both in interactive and
  4526 batch mode.
  4527 
  4528 * Isar: simplified interfaces for outer syntax.  Renamed
  4529 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4530 OuterSyntax.add_parsers -- this functionality is now included in
  4531 OuterSyntax.command etc.  INCOMPATIBILITY.
  4532 
  4533 * Simplifier: the simpset of a running simplification process now
  4534 contains a proof context (cf. Simplifier.the_context), which is the
  4535 very context that the initial simpset has been retrieved from (by
  4536 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4537 (solver, looper etc.) may depend on arbitrary proof data.
  4538 
  4539 * Simplifier.inherit_context inherits the proof context (plus the
  4540 local bounds) of the current simplification process; any simproc
  4541 etc. that calls the Simplifier recursively should do this!  Removed
  4542 former Simplifier.inherit_bounds, which is already included here --
  4543 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4544 specify an explicit context using Simplifier.context/theory_context.
  4545 
  4546 * Simplifier/Classical Reasoner: more abstract interfaces
  4547 change_simpset/claset for modifying the simpset/claset reference of a
  4548 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4549 INCOMPATIBILITY.
  4550 
  4551 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4552 "Trueprop" etc.
  4553 
  4554 
  4555 *** System ***
  4556 
  4557 * settings: the default heap location within ISABELLE_HOME_USER now
  4558 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4559 Isabelle installations.
  4560 
  4561 * isabelle-process: option -S (secure mode) disables some critical
  4562 operations, notably runtime compilation and evaluation of ML source
  4563 code.
  4564 
  4565 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4566 
  4567 * Support for parallel execution, using native multicore support of
  4568 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4569 independent theories, according to the given theory header
  4570 specifications. The maximum number of worker threads is specified via
  4571 usedir option -M or the "max-threads" setting in Proof General. A
  4572 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4573 to 6 on a 8-core machine.  User-code needs to observe certain
  4574 guidelines for thread-safe programming, see appendix A in the Isar
  4575 Implementation manual.
  4576 
  4577 
  4578 
  4579 New in Isabelle2005 (October 2005)
  4580 ----------------------------------
  4581 
  4582 *** General ***
  4583 
  4584 * Theory headers: the new header syntax for Isar theories is
  4585 
  4586   theory <name>
  4587   imports <theory1> ... <theoryN>
  4588   uses <file1> ... <fileM>
  4589   begin
  4590 
  4591 where the 'uses' part is optional.  The previous syntax
  4592 
  4593   theory <name> = <theory1> + ... + <theoryN>:
  4594 
  4595 will disappear in the next release.  Use isatool fixheaders to convert
  4596 existing theory files.  Note that there is no change in ancient
  4597 non-Isar theories now, but these will disappear soon.
  4598 
  4599 * Theory loader: parent theories can now also be referred to via
  4600 relative and absolute paths.
  4601 
  4602 * Command 'find_theorems' searches for a list of criteria instead of a
  4603 list of constants. Known criteria are: intro, elim, dest, name:string,
  4604 simp:term, and any term. Criteria can be preceded by '-' to select
  4605 theorems that do not match. Intro, elim, dest select theorems that
  4606 match the current goal, name:s selects theorems whose fully qualified
  4607 name contain s, and simp:term selects all simplification rules whose
  4608 lhs match term.  Any other term is interpreted as pattern and selects
  4609 all theorems matching the pattern. Available in ProofGeneral under
  4610 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4611 
  4612   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4613 
  4614 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4615 matching the current goal as introduction rule and not having "HOL."
  4616 in their name (i.e. not being defined in theory HOL).
  4617 
  4618 * Command 'thms_containing' has been discontinued in favour of
  4619 'find_theorems'; INCOMPATIBILITY.
  4620 
  4621 * Communication with Proof General is now 8bit clean, which means that
  4622 Unicode text in UTF-8 encoding may be used within theory texts (both
  4623 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4624 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4625 
  4626   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4627   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4628 
  4629 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4630 Classical Reasoner.  Typical big applications run around 2 times
  4631 faster.
  4632 
  4633 
  4634 *** Document preparation ***
  4635 
  4636 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4637 of raw sources.  Only those symbols that do not require additional
  4638 LaTeX packages (depending on comments in isabellesym.sty) are
  4639 displayed properly, everything else is left verbatim.  isatool display
  4640 and isatool print are used as front ends (these are subject to the
  4641 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4642 
  4643 * Command tags control specific markup of certain regions of text,
  4644 notably folding and hiding.  Predefined tags include "theory" (for
  4645 theory begin and end), "proof" for proof commands, and "ML" for
  4646 commands involving ML code; the additional tags "visible" and
  4647 "invisible" are unused by default.  Users may give explicit tag
  4648 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4649 interpretation of tags is determined by the LaTeX job during document
  4650 preparation: see option -V of isatool usedir, or options -n and -t of
  4651 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4652 \isadroptag.
  4653 
  4654 Several document versions may be produced at the same time via isatool
  4655 usedir (the generated index.html will link all of them).  Typical
  4656 specifications include ''-V document=theory,proof,ML'' to present
  4657 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4658 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4659 these parts without any formal replacement text.  The Isabelle site
  4660 default settings produce ''document'' and ''outline'' versions as
  4661 specified above.
  4662 
  4663 * Several new antiquotations:
  4664 
  4665   @{term_type term} prints a term with its type annotated;
  4666 
  4667   @{typeof term} prints the type of a term;
  4668 
  4669   @{const const} is the same as @{term const}, but checks that the
  4670   argument is a known logical constant;
  4671 
  4672   @{term_style style term} and @{thm_style style thm} print a term or
  4673   theorem applying a "style" to it
  4674 
  4675   @{ML text}
  4676 
  4677 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4678 definitions, equations, inequations etc., 'concl' printing only the
  4679 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4680 to print the specified premise.  TermStyle.add_style provides an ML
  4681 interface for introducing further styles.  See also the "LaTeX Sugar"
  4682 document practical applications.  The ML antiquotation prints
  4683 type-checked ML expressions verbatim.
  4684 
  4685 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4686 and 'text' support optional locale specification '(in loc)', which
  4687 specifies the default context for interpreting antiquotations.  For
  4688 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4689 
  4690 * Option 'locale=NAME' of antiquotations specifies an alternative
  4691 context interpreting the subsequent argument.  For example: @{thm
  4692 [locale=lattice] inf_assoc}.
  4693 
  4694 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4695 a proof context.
  4696 
  4697 * Proper output of antiquotations for theory commands involving a
  4698 proof context (such as 'locale' or 'theorem (in loc) ...').
  4699 
  4700 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4701 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4702 
  4703 * isatool usedir: new option -C (default true) controls whether option
  4704 -D should include a copy of the original document directory; -C false
  4705 prevents unwanted effects such as copying of administrative CVS data.
  4706 
  4707 
  4708 *** Pure ***
  4709 
  4710 * Considerably improved version of 'constdefs' command.  Now performs
  4711 automatic type-inference of declared constants; additional support for
  4712 local structure declarations (cf. locales and HOL records), see also
  4713 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4714 sequential dependencies of definitions within a single 'constdefs'
  4715 section; moreover, the declared name needs to be an identifier.  If
  4716 all fails, consider to fall back on 'consts' and 'defs' separately.
  4717 
  4718 * Improved indexed syntax and implicit structures.  First of all,
  4719 indexed syntax provides a notational device for subscripted
  4720 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4721 expressions.  Secondly, in a local context with structure
  4722 declarations, number indexes \<^sub>n or the empty index (default
  4723 number 1) refer to a certain fixed variable implicitly; option
  4724 show_structs controls printing of implicit structures.  Typical
  4725 applications of these concepts involve record types and locales.
  4726 
  4727 * New command 'no_syntax' removes grammar declarations (and
  4728 translations) resulting from the given syntax specification, which is
  4729 interpreted in the same manner as for the 'syntax' command.
  4730 
  4731 * 'Advanced' translation functions (parse_translation etc.) may depend
  4732 on the signature of the theory context being presently used for
  4733 parsing/printing, see also isar-ref manual.
  4734 
  4735 * Improved 'oracle' command provides a type-safe interface to turn an
  4736 ML expression of type theory -> T -> term into a primitive rule of
  4737 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4738 is already included here); see also FOL/ex/IffExample.thy;
  4739 INCOMPATIBILITY.
  4740 
  4741 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4742 before); "cI" is no longer bound, use "c.intro" instead.
  4743 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4744 axclasses vs. locales.
  4745 
  4746 * Improved internal renaming of symbolic identifiers -- attach primes
  4747 instead of base 26 numbers.
  4748 
  4749 * New flag show_question_marks controls printing of leading question
  4750 marks in schematic variable names.
  4751 
  4752 * In schematic variable names, *any* symbol following \<^isub> or
  4753 \<^isup> is now treated as part of the base name.  For example, the
  4754 following works without printing of awkward ".0" indexes:
  4755 
  4756   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4757     by simp
  4758 
  4759 * Inner syntax includes (*(*nested*) comments*).
  4760 
  4761 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4762 annotations as "(00...)".
  4763 
  4764 * Clear separation of logical types and nonterminals, where the latter
  4765 may only occur in 'syntax' specifications or type abbreviations.
  4766 Before that distinction was only partially implemented via type class
  4767 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4768 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4769 exotic syntax specifications may require further adaption
  4770 (e.g. Cube/Cube.thy).
  4771 
  4772 * Removed obsolete type class "logic", use the top sort {} instead.
  4773 Note that non-logical types should be declared as 'nonterminals'
  4774 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4775 specifications.
  4776 
  4777 * Attributes 'induct' and 'cases': type or set names may now be
  4778 locally fixed variables as well.
  4779 
  4780 * Simplifier: can now control the depth to which conditional rewriting
  4781 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4782 Limit.
  4783 
  4784 * Simplifier: simplification procedures may now take the current
  4785 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4786 interface), which is very useful for calling the Simplifier
  4787 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4788 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4789 low-level mk_simproc no longer applies Logic.varify internally, to
  4790 allow for use in a context of fixed variables.
  4791 
  4792 * thin_tac now works even if the assumption being deleted contains !!
  4793 or ==>.  More generally, erule now works even if the major premise of
  4794 the elimination rule contains !! or ==>.
  4795 
  4796 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4797 
  4798 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4799 from Pure, which contains all common declarations already.  Both
  4800 theories are defined via plain Isabelle/Isar .thy files.
  4801 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4802 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4803 use isatool fixcpure to adapt your theory and ML sources.
  4804 
  4805 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4806 selections of theorems in named facts via index ranges.
  4807 
  4808 * 'print_theorems': in theory mode, really print the difference
  4809 wrt. the last state (works for interactive theory development only),
  4810 in proof mode print all local facts (cf. 'print_facts');
  4811 
  4812 * 'hide': option '(open)' hides only base names.
  4813 
  4814 * More efficient treatment of intermediate checkpoints in interactive
  4815 theory development.
  4816 
  4817 * Code generator is now invoked via code_module (incremental code
  4818 generation) and code_library (modular code generation, ML structures
  4819 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4820 must be quoted when used as identifiers.
  4821 
  4822 * New 'value' command for reading, evaluating and printing terms using
  4823 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4824 quoted when used as identifier.
  4825 
  4826 
  4827 *** Locales ***
  4828 
  4829 * New commands for the interpretation of locale expressions in
  4830 theories (1), locales (2) and proof contexts (3).  These generate
  4831 proof obligations from the expression specification.  After the
  4832 obligations have been discharged, theorems of the expression are added
  4833 to the theory, target locale or proof context.  The synopsis of the
  4834 commands is a follows:
  4835 
  4836   (1) interpretation expr inst
  4837   (2) interpretation target < expr
  4838   (3) interpret expr inst
  4839 
  4840 Interpretation in theories and proof contexts require a parameter
  4841 instantiation of terms from the current context.  This is applied to
  4842 specifications and theorems of the interpreted expression.
  4843 Interpretation in locales only permits parameter renaming through the
  4844 locale expression.  Interpretation is smart in that interpretations
  4845 that are active already do not occur in proof obligations, neither are
  4846 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4847 inspect active interpretations of a particular locale.  For details,
  4848 see the Isar Reference manual.  Examples can be found in
  4849 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4850 
  4851 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4852 'interpret' instead.
  4853 
  4854 * New context element 'constrains' for adding type constraints to
  4855 parameters.
  4856 
  4857 * Context expressions: renaming of parameters with syntax
  4858 redeclaration.
  4859 
  4860 * Locale declaration: 'includes' disallowed.
  4861 
  4862 * Proper static binding of attribute syntax -- i.e. types / terms /
  4863 facts mentioned as arguments are always those of the locale definition
  4864 context, independently of the context of later invocations.  Moreover,
  4865 locale operations (renaming and type / term instantiation) are applied
  4866 to attribute arguments as expected.
  4867 
  4868 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4869 actual attributes; rare situations may require Attrib.attribute to
  4870 embed those attributes into Attrib.src that lack concrete syntax.
  4871 Attribute implementations need to cooperate properly with the static
  4872 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4873 Attrib.XXX_thm etc. already do the right thing without further
  4874 intervention.  Only unusual applications -- such as "where" or "of"
  4875 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4876 on the context and the facts involved -- may have to assign parsed
  4877 values to argument tokens explicitly.
  4878 
  4879 * Changed parameter management in theorem generation for long goal
  4880 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4881 theorem statement in rare situations.
  4882 
  4883 * Locale inspection command 'print_locale' omits notes elements.  Use
  4884 'print_locale!' to have them included in the output.
  4885 
  4886 
  4887 *** Provers ***
  4888 
  4889 * Provers/hypsubst.ML: improved version of the subst method, for
  4890 single-step rewriting: it now works in bound variable contexts. New is
  4891 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4892 rewrite a different subterm than the original subst method, which is
  4893 still available as 'simplesubst'.
  4894 
  4895 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4896 and quasi orders.
  4897 
  4898 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4899 reflexive-transitive closure of relations.
  4900 
  4901 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4902 limit (previously hard-coded with a value of 20) user-definable.
  4903 
  4904 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4905 is peformed already.  Object-logics merely need to finish their
  4906 initial simpset configuration as before.  INCOMPATIBILITY.
  4907 
  4908 
  4909 *** HOL ***
  4910 
  4911 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4912 
  4913   syntax (epsilon)
  4914     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4915 
  4916 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4917 and x-symbol; use option '-m epsilon' to get it actually printed.
  4918 Moreover, the mathematically important symbolic identifier \<epsilon>
  4919 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4920 
  4921 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4922 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4923 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4924 support corresponding Isar calculations.
  4925 
  4926 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4927 instead of ":".
  4928 
  4929 * theory SetInterval: changed the syntax for open intervals:
  4930 
  4931   Old       New
  4932   {..n(}    {..<n}
  4933   {)n..}    {n<..}
  4934   {m..n(}   {m..<n}
  4935   {)m..n}   {m<..n}
  4936   {)m..n(}  {m<..<n}
  4937 
  4938 The old syntax is still supported but will disappear in the next
  4939 release.  For conversion use the following Emacs search and replace
  4940 patterns (these are not perfect but work quite well):
  4941 
  4942   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4943   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4944 
  4945 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4946 equalities in commutative rings; method 'algebra' provides a generic
  4947 interface.
  4948 
  4949 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4950 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4951 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4952 be a tuple pattern.
  4953 
  4954 Some new syntax forms are available:
  4955 
  4956   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4957   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4958   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4959   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4960 
  4961 The latter form "\<Sum>x < k. e" used to be based on a separate
  4962 function "Summation", which has been discontinued.
  4963 
  4964 * theory Finite_Set: in structured induction proofs, the insert case
  4965 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4966 (insert F x)'.
  4967 
  4968 * The 'refute' command has been extended to support a much larger
  4969 fragment of HOL, including axiomatic type classes, constdefs and
  4970 typedefs, inductive datatypes and recursion.
  4971 
  4972 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4973 Requires zChaff with proof generation to be installed.  See
  4974 HOL/ex/SAT_Examples.thy for examples.
  4975 
  4976 * Datatype induction via method 'induct' now preserves the name of the
  4977 induction variable. For example, when proving P(xs::'a list) by
  4978 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4979 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4980 in unstructured proof scripts.
  4981 
  4982 * Reworked implementation of records.  Improved scalability for
  4983 records with many fields, avoiding performance problems for type
  4984 inference. Records are no longer composed of nested field types, but
  4985 of nested extension types. Therefore the record type only grows linear
  4986 in the number of extensions and not in the number of fields.  The
  4987 top-level (users) view on records is preserved.  Potential
  4988 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4989 old record representation. The type generated for a record is called
  4990 <record_name>_ext_type.
  4991 
  4992 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4993 proofs triggered by a record definition or a simproc (if
  4994 quick_and_dirty is enabled).  Definitions of large records can take
  4995 quite long.
  4996 
  4997 New simproc record_upd_simproc for simplification of multiple record
  4998 updates enabled by default.  Moreover, trivial updates are also
  4999 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5000 occasionally, since simplification is more powerful by default.
  5001 
  5002 * typedef: proper support for polymorphic sets, which contain extra
  5003 type-variables in the term.
  5004 
  5005 * Simplifier: automatically reasons about transitivity chains
  5006 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5007 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5008 old proofs break occasionally as simplification may now solve more
  5009 goals than previously.
  5010 
  5011 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5012 present.  Works for all partial orders (class "order"), in particular
  5013 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5014 just like y <= x.
  5015 
  5016 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5017 bound variable or a constant then the let is unfolded.  Otherwise
  5018 first a is simplified to b, and then f b is simplified to g. If
  5019 possible we abstract b from g arriving at "let x = b in h x",
  5020 otherwise we unfold the let and arrive at g.  The simproc can be
  5021 enabled/disabled by the reference use_let_simproc.  Potential
  5022 INCOMPATIBILITY since simplification is more powerful by default.
  5023 
  5024 * Classical reasoning: the meson method now accepts theorems as arguments.
  5025 
  5026 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5027 jobs to provide advice on the provability of subgoals.
  5028 
  5029 * Theory OrderedGroup and Ring_and_Field: various additions and
  5030 improvements to faciliate calculations involving equalities and
  5031 inequalities.
  5032 
  5033 The following theorems have been eliminated or modified
  5034 (INCOMPATIBILITY):
  5035 
  5036   abs_eq             now named abs_of_nonneg
  5037   abs_of_ge_0        now named abs_of_nonneg
  5038   abs_minus_eq       now named abs_of_nonpos
  5039   imp_abs_id         now named abs_of_nonneg
  5040   imp_abs_neg_id     now named abs_of_nonpos
  5041   mult_pos           now named mult_pos_pos
  5042   mult_pos_le        now named mult_nonneg_nonneg
  5043   mult_pos_neg_le    now named mult_nonneg_nonpos
  5044   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5045   mult_neg           now named mult_neg_neg
  5046   mult_neg_le        now named mult_nonpos_nonpos
  5047 
  5048 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5049      
  5050      zero_le_square
  5051      not_square_less_zero 
  5052 
  5053   The following lemmas have been deleted from Real/RealPow:
  5054   
  5055      realpow_zero_zero
  5056      realpow_two
  5057      realpow_less
  5058      zero_le_power
  5059      realpow_two_le
  5060      abs_realpow_two
  5061      realpow_two_abs     
  5062 
  5063 * Theory Parity: added rules for simplifying exponents.
  5064 
  5065 * Theory List:
  5066 
  5067 The following theorems have been eliminated or modified
  5068 (INCOMPATIBILITY):
  5069 
  5070   list_all_Nil       now named list_all.simps(1)
  5071   list_all_Cons      now named list_all.simps(2)
  5072   list_all_conv      now named list_all_iff
  5073   set_mem_eq         now named mem_iff
  5074 
  5075 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5076 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5077 
  5078 
  5079 *** HOL-Complex ***
  5080 
  5081 * Theory RealDef: better support for embedding natural numbers and
  5082 integers in the reals.
  5083 
  5084 The following theorems have been eliminated or modified
  5085 (INCOMPATIBILITY):
  5086 
  5087   exp_ge_add_one_self  now requires no hypotheses
  5088   real_of_int_add      reversed direction of equality (use [symmetric])
  5089   real_of_int_minus    reversed direction of equality (use [symmetric])
  5090   real_of_int_diff     reversed direction of equality (use [symmetric])
  5091   real_of_int_mult     reversed direction of equality (use [symmetric])
  5092 
  5093 * Theory RComplete: expanded support for floor and ceiling functions.
  5094 
  5095 * Theory Ln is new, with properties of the natural logarithm
  5096 
  5097 * Hyperreal: There is a new type constructor "star" for making
  5098 nonstandard types.  The old type names are now type synonyms:
  5099 
  5100   hypreal = real star
  5101   hypnat = nat star
  5102   hcomplex = complex star
  5103 
  5104 * Hyperreal: Many groups of similarly-defined constants have been
  5105 replaced by polymorphic versions (INCOMPATIBILITY):
  5106 
  5107   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5108 
  5109   starset      <-- starsetNat, starsetC
  5110   *s*          <-- *sNat*, *sc*
  5111   starset_n    <-- starsetNat_n, starsetC_n
  5112   *sn*         <-- *sNatn*, *scn*
  5113   InternalSets <-- InternalNatSets, InternalCSets
  5114 
  5115   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5116   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5117   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5118   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5119   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5120 
  5121 * Hyperreal: Many type-specific theorems have been removed in favor of
  5122 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5123 
  5124   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5125   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5126   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5127   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5128   right_minus <-- hypreal_add_minus
  5129   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5130   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5131   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5132   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5133   mult_1_right <-- hcomplex_mult_one_right
  5134   mult_zero_left <-- hcomplex_mult_zero_left
  5135   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5136   right_distrib <-- hypnat_add_mult_distrib2
  5137   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5138   right_inverse <-- hypreal_mult_inverse
  5139   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5140   order_refl <-- {hypreal,hypnat}_le_refl
  5141   order_trans <-- {hypreal,hypnat}_le_trans
  5142   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5143   order_less_le <-- {hypreal,hypnat}_less_le
  5144   linorder_linear <-- {hypreal,hypnat}_le_linear
  5145   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5146   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5147   add_nonneg_nonneg <-- hypreal_le_add_order
  5148 
  5149 * Hyperreal: Separate theorems having to do with type-specific
  5150 versions of constants have been merged into theorems that apply to the
  5151 new polymorphic constants (INCOMPATIBILITY):
  5152 
  5153   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5154   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5155   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5156   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5157   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5158   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5159   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5160   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5161   STAR_diff <-- {STAR,STARC}_diff
  5162   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5163     STARC_hcomplex_of_complex}_image_subset
  5164   starset_n_Un <-- starset{Nat,C}_n_Un
  5165   starset_n_Int <-- starset{Nat,C}_n_Int
  5166   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5167   starset_n_diff <-- starset{Nat,C}_n_diff
  5168   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5169   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5170   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5171   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5172   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5173   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5174   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5175   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5176   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5177   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5178   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5179   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5180   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5181   starfun_diff <-- starfun{C,RC,CR}_diff
  5182   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5183   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5184   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5185   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5186   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5187   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5188   starfun_Id <-- starfunC_Id
  5189   starfun_approx <-- starfun{Nat,CR}_approx
  5190   starfun_capprox <-- starfun{C,RC}_capprox
  5191   starfun_abs <-- starfunNat_rabs
  5192   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5193   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5194   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5195   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5196   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5197   starfun_add_approx <-- starfunCR_add_approx
  5198   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5199   starfun_divide <-- starfun{C,CR,RC}_divide
  5200   starfun_n <-- starfun{Nat,C}_n
  5201   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5202   starfun_n_add <-- starfun{Nat,C}_n_add
  5203   starfun_n_add_minus <-- starfunNat_n_add_minus
  5204   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5205   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5206   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5207 
  5208   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5209   star_n_minus <-- {hypreal,hcomplex}_minus
  5210   star_n_diff <-- {hypreal,hcomplex}_diff
  5211   star_n_mult <-- {hypreal,hcomplex}_mult
  5212   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5213   star_n_le <-- {hypreal,hypnat}_le
  5214   star_n_less <-- {hypreal,hypnat}_less
  5215   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5216   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5217   star_n_abs <-- hypreal_hrabs
  5218   star_n_divide <-- hcomplex_divide
  5219 
  5220   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5221   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5222   star_of_diff <-- hypreal_of_real_diff
  5223   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5224   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5225   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5226   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5227   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5228   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5229   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5230   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5231   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5232   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5233   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5234   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5235   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5236   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5237   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5238   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5239   star_of_power <-- hypreal_of_real_power
  5240   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5241 
  5242 * Hyperreal: new method "transfer" that implements the transfer
  5243 principle of nonstandard analysis. With a subgoal that mentions
  5244 nonstandard types like "'a star", the command "apply transfer"
  5245 replaces it with an equivalent one that mentions only standard types.
  5246 To be successful, all free variables must have standard types; non-
  5247 standard variables must have explicit universal quantifiers.
  5248 
  5249 * Hyperreal: A theory of Taylor series.
  5250 
  5251 
  5252 *** HOLCF ***
  5253 
  5254 * Discontinued special version of 'constdefs' (which used to support
  5255 continuous functions) in favor of the general Pure one with full
  5256 type-inference.
  5257 
  5258 * New simplification procedure for solving continuity conditions; it
  5259 is much faster on terms with many nested lambda abstractions (cubic
  5260 instead of exponential time).
  5261 
  5262 * New syntax for domain package: selector names are now optional.
  5263 Parentheses should be omitted unless argument is lazy, for example:
  5264 
  5265   domain 'a stream = cons "'a" (lazy "'a stream")
  5266 
  5267 * New command 'fixrec' for defining recursive functions with pattern
  5268 matching; defining multiple functions with mutual recursion is also
  5269 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5270 sinr, or any data constructor defined by the domain package. The given
  5271 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5272 syntax and examples.
  5273 
  5274 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5275 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5276 but the proof obligation additionally includes an admissibility
  5277 requirement. The packages generate instances of class cpo or pcpo,
  5278 with continuity and strictness theorems for Rep and Abs.
  5279 
  5280 * HOLCF: Many theorems have been renamed according to a more standard naming
  5281 scheme (INCOMPATIBILITY):
  5282 
  5283   foo_inject:  "foo$x = foo$y ==> x = y"
  5284   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5285   foo_less:    "(foo$x << foo$y) = (x << y)"
  5286   foo_strict:  "foo$UU = UU"
  5287   foo_defined: "... ==> foo$x ~= UU"
  5288   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5289 
  5290 
  5291 *** ZF ***
  5292 
  5293 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5294 including the First Isomorphism Theorem (on quotienting by the kernel
  5295 of a homomorphism).
  5296 
  5297 * ZF/Simplifier: install second copy of type solver that actually
  5298 makes use of TC rules declared to Isar proof contexts (or locales);
  5299 the old version is still required for ML proof scripts.
  5300 
  5301 
  5302 *** Cube ***
  5303 
  5304 * Converted to Isar theory format; use locales instead of axiomatic
  5305 theories.
  5306 
  5307 
  5308 *** ML ***
  5309 
  5310 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5311 for ||>, ||>>, |>>,
  5312 
  5313 * Pure/library.ML no longer defines its own option datatype, but uses
  5314 that of the SML basis, which has constructors NONE and SOME instead of
  5315 None and Some, as well as exception Option.Option instead of OPTION.
  5316 The functions the, if_none, is_some, is_none have been adapted
  5317 accordingly, while Option.map replaces apsome.
  5318 
  5319 * Pure/library.ML: the exception LIST has been given up in favour of
  5320 the standard exceptions Empty and Subscript, as well as
  5321 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5322 superceded by the standard hd and tl functions etc.
  5323 
  5324 A number of basic list functions are no longer exported to the ML
  5325 toplevel, as they are variants of predefined functions.  The following
  5326 suggests how one can translate existing code:
  5327 
  5328     rev_append xs ys = List.revAppend (xs, ys)
  5329     nth_elem (i, xs) = List.nth (xs, i)
  5330     last_elem xs = List.last xs
  5331     flat xss = List.concat xss
  5332     seq fs = List.app fs
  5333     partition P xs = List.partition P xs
  5334     mapfilter f xs = List.mapPartial f xs
  5335 
  5336 * Pure/library.ML: several combinators for linear functional
  5337 transformations, notably reverse application and composition:
  5338 
  5339   x |> f                f #> g
  5340   (x, y) |-> f          f #-> g
  5341 
  5342 * Pure/library.ML: introduced/changed precedence of infix operators:
  5343 
  5344   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5345   infix 2 ?;
  5346   infix 3 o oo ooo oooo;
  5347   infix 4 ~~ upto downto;
  5348 
  5349 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5350 infix operators.
  5351 
  5352 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5353 fold_map support linear functional transformations and nesting.  For
  5354 example:
  5355 
  5356   fold f [x1, ..., xN] y =
  5357     y |> f x1 |> ... |> f xN
  5358 
  5359   (fold o fold) f [xs1, ..., xsN] y =
  5360     y |> fold f xs1 |> ... |> fold f xsN
  5361 
  5362   fold f [x1, ..., xN] =
  5363     f x1 #> ... #> f xN
  5364 
  5365   (fold o fold) f [xs1, ..., xsN] =
  5366     fold f xs1 #> ... #> fold f xsN
  5367 
  5368 * Pure/library.ML: the following selectors on type 'a option are
  5369 available:
  5370 
  5371   the:               'a option -> 'a  (*partial*)
  5372   these:             'a option -> 'a  where 'a = 'b list
  5373   the_default: 'a -> 'a option -> 'a
  5374   the_list:          'a option -> 'a list
  5375 
  5376 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5377 basic operations for association lists, following natural argument
  5378 order; moreover the explicit equality predicate passed here avoids
  5379 potentially expensive polymorphic runtime equality checks.
  5380 The old functions may be expressed as follows:
  5381 
  5382   assoc = uncurry (AList.lookup (op =))
  5383   assocs = these oo AList.lookup (op =)
  5384   overwrite = uncurry (AList.update (op =)) o swap
  5385 
  5386 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5387 
  5388   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5389   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5390 
  5391 replacing make_keylist and keyfilter (occassionally used)
  5392 Naive rewrites:
  5393 
  5394   make_keylist = AList.make
  5395   keyfilter = AList.find (op =)
  5396 
  5397 * eq_fst and eq_snd now take explicit equality parameter, thus
  5398   avoiding eqtypes. Naive rewrites:
  5399 
  5400     eq_fst = eq_fst (op =)
  5401     eq_snd = eq_snd (op =)
  5402 
  5403 * Removed deprecated apl and apr (rarely used).
  5404   Naive rewrites:
  5405 
  5406     apl (n, op) =>>= curry op n
  5407     apr (op, m) =>>= fn n => op (n, m)
  5408 
  5409 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5410 provides a reasonably efficient light-weight implementation of sets as
  5411 lists.
  5412 
  5413 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5414 few new operations; existing lookup and update are now curried to
  5415 follow natural argument order (for use with fold etc.);
  5416 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5417 
  5418 * Pure/General: output via the Isabelle channels of
  5419 writeln/warning/error etc. is now passed through Output.output, with a
  5420 hook for arbitrary transformations depending on the print_mode
  5421 (cf. Output.add_mode -- the first active mode that provides a output
  5422 function wins).  Already formatted output may be embedded into further
  5423 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5424 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5425 accommodate easy composition of diagnostic messages etc.  Programmers
  5426 rarely need to care about Output.output or Output.raw at all, with
  5427 some notable exceptions: Output.output is required when bypassing the
  5428 standard channels (writeln etc.), or in token translations to produce
  5429 properly formatted results; Output.raw is required when capturing
  5430 already output material that will eventually be presented to the user
  5431 a second time.  For the default print mode, both Output.output and
  5432 Output.raw have no effect.
  5433 
  5434 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5435 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5436 cumulative results are displayed at the end of a batch session.
  5437 
  5438 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5439 replaced by File.platform_path and File.shell_path (with appropriate
  5440 hooks).  This provides a clean interface for unusual systems where the
  5441 internal and external process view of file names are different.
  5442 
  5443 * Pure: more efficient orders for basic syntactic entities: added
  5444 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5445 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5446 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5447 orders now -- potential INCOMPATIBILITY for code that depends on a
  5448 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5449 Library.sort_strings on result).
  5450 
  5451 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5452 fold_types traverse types/terms from left to right, observing natural
  5453 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5454 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5455 
  5456 * Pure: name spaces have been refined, with significant changes of the
  5457 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5458 to extern(_table).  The plain name entry path is superceded by a
  5459 general 'naming' context, which also includes the 'policy' to produce
  5460 a fully qualified name and external accesses of a fully qualified
  5461 name; NameSpace.extend is superceded by context dependent
  5462 Sign.declare_name.  Several theory and proof context operations modify
  5463 the naming context.  Especially note Theory.restore_naming and
  5464 ProofContext.restore_naming to get back to a sane state; note that
  5465 Theory.add_path is no longer sufficient to recover from
  5466 Theory.absolute_path in particular.
  5467 
  5468 * Pure: new flags short_names (default false) and unique_names
  5469 (default true) for controlling output of qualified names.  If
  5470 short_names is set, names are printed unqualified.  If unique_names is
  5471 reset, the name prefix is reduced to the minimum required to achieve
  5472 the original result when interning again, even if there is an overlap
  5473 with earlier declarations.
  5474 
  5475 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5476 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5477 (useful for printing error messages).  INCOMPATIBILITY.
  5478 
  5479 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5480 Theory.theory are now identified, referring to the universal
  5481 Context.theory (see Pure/context.ML).  Actual signature and theory
  5482 content is managed as theory data.  The old code and interfaces were
  5483 spread over many files and structures; the new arrangement introduces
  5484 considerable INCOMPATIBILITY to gain more clarity:
  5485 
  5486   Context -- theory management operations (name, identity, inclusion,
  5487     parents, ancestors, merge, etc.), plus generic theory data;
  5488 
  5489   Sign -- logical signature and syntax operations (declaring consts,
  5490     types, etc.), plus certify/read for common entities;
  5491 
  5492   Theory -- logical theory operations (stating axioms, definitions,
  5493     oracles), plus a copy of logical signature operations (consts,
  5494     types, etc.); also a few basic management operations (Theory.copy,
  5495     Theory.merge, etc.)
  5496 
  5497 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5498 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5499 for convenience -- they merely return the theory.
  5500 
  5501 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5502 
  5503 * Pure: the Isar proof context type is already defined early in Pure
  5504 as Context.proof (note that ProofContext.context and Proof.context are
  5505 aliases, where the latter is the preferred name).  This enables other
  5506 Isabelle components to refer to that type even before Isar is present.
  5507 
  5508 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5509 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5510 any of these kinds.  For example, Sign.intern typeK is now
  5511 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5512 Theory.hide_types.  Also note that former
  5513 Theory.hide_classes/types/consts are now
  5514 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5515 internalize their arguments!  INCOMPATIBILITY.
  5516 
  5517 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5518 datatype thmref (with constructors Name and NameSelection) instead of
  5519 plain string -- INCOMPATIBILITY;
  5520 
  5521 * Pure: cases produced by proof methods specify options, where NONE
  5522 means to remove case bindings -- INCOMPATIBILITY in
  5523 (RAW_)METHOD_CASES.
  5524 
  5525 * Pure: the following operations retrieve axioms or theorems from a
  5526 theory node or theory hierarchy, respectively:
  5527 
  5528   Theory.axioms_of: theory -> (string * term) list
  5529   Theory.all_axioms_of: theory -> (string * term) list
  5530   PureThy.thms_of: theory -> (string * thm) list
  5531   PureThy.all_thms_of: theory -> (string * thm) list
  5532 
  5533 * Pure: print_tac now outputs the goal through the trace channel.
  5534 
  5535 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5536 Reference Toplevel.debug (default false) controls detailed printing
  5537 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5538 controls execution profiling -- set to 1 for time and 2 for space
  5539 (both increase the runtime).
  5540 
  5541 * Isar session: The initial use of ROOT.ML is now always timed,
  5542 i.e. the log will show the actual process times, in contrast to the
  5543 elapsed wall-clock time that the outer shell wrapper produces.
  5544 
  5545 * Simplifier: improved handling of bound variables (nameless
  5546 representation, avoid allocating new strings).  Simprocs that invoke
  5547 the Simplifier recursively should use Simplifier.inherit_bounds to
  5548 avoid local name clashes.  Failure to do so produces warnings
  5549 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5550 for further details.
  5551 
  5552 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5553 bindings for all theorems stored within a given theory; this may help
  5554 in porting non-Isar theories to Isar ones, while keeping ML proof
  5555 scripts for the time being.
  5556 
  5557 * ML operator HTML.with_charset specifies the charset begin used for
  5558 generated HTML files.  For example:
  5559 
  5560   HTML.with_charset "utf-8" use_thy "Hebrew";
  5561   HTML.with_charset "utf-8" use_thy "Chinese";
  5562 
  5563 
  5564 *** System ***
  5565 
  5566 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5567 isabelle, isatool etc.).
  5568 
  5569 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5570 isatool doc, isatool mkdir, display_drafts etc.).
  5571 
  5572 * isatool usedir: option -f allows specification of the ML file to be
  5573 used by Isabelle; default is ROOT.ML.
  5574 
  5575 * New isatool version outputs the version identifier of the Isabelle
  5576 distribution being used.
  5577 
  5578 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5579 (containing Boolean satisfiability problems) into Isabelle/HOL
  5580 theories.
  5581 
  5582 
  5583 
  5584 New in Isabelle2004 (April 2004)
  5585 --------------------------------
  5586 
  5587 *** General ***
  5588 
  5589 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5590   Replaces linorder.ML.
  5591 
  5592 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5593   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5594   (\<a>...\<z>), are now considered normal letters, and can therefore
  5595   be used anywhere where an ASCII letter (a...zA...Z) has until
  5596   now. COMPATIBILITY: This obviously changes the parsing of some
  5597   terms, especially where a symbol has been used as a binder, say
  5598   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5599   as an identifier.  Fix it by inserting a space around former
  5600   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5601   existing theory and ML files.
  5602 
  5603 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5604 
  5605 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5606   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5607   a normal (but invisible) letter. For multiple letter subscripts repeat
  5608   \<^isub> like this: x\<^isub>1\<^isub>2.
  5609 
  5610 * Pure: There are now sub-/superscripts that can span more than one
  5611   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5612   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5613   superscript. The new control characters are not identifier parts.
  5614 
  5615 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5616   content of "..." to the latex file instead of \isacntrl... . The "..."
  5617   may consist of any printable characters excluding the end bracket >.
  5618 
  5619 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5620   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5621   declare constants "final", which prevents their being given a definition
  5622   later.  It is useful for constants whose behaviour is fixed axiomatically
  5623   rather than definitionally, such as the meta-logic connectives.
  5624 
  5625 * Pure: 'instance' now handles general arities with general sorts
  5626   (i.e. intersections of classes),
  5627 
  5628 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5629   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5630   It can be changed to alter the colors/layout of generated pages.
  5631 
  5632 
  5633 *** Isar ***
  5634 
  5635 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5636   cut_tac, subgoal_tac and thin_tac:
  5637   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5638     locales are no longer forced to write Isar proof scripts.
  5639     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5640     emulations.
  5641   - INCOMPATIBILITY: names of variables to be instantiated may no
  5642     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5643     This is consistent with the instantiation attribute "where".
  5644 
  5645 * Attributes "where" and "of":
  5646   - Now take type variables of instantiated theorem into account when reading
  5647     the instantiation string.  This fixes a bug that caused instantiated
  5648     theorems to have too special types in some circumstances.
  5649   - "where" permits explicit instantiations of type variables.
  5650 
  5651 * Calculation commands "moreover" and "also" no longer interfere with
  5652   current facts ("this"), admitting arbitrary combinations with "then"
  5653   and derived forms.
  5654 
  5655 * Locales:
  5656   - Goal statements involving the context element "includes" no longer
  5657     generate theorems with internal delta predicates (those ending on
  5658     "_axioms") in the premise.
  5659     Resolve particular premise with <locale>.intro to obtain old form.
  5660   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5661     specification and "includes" elements in goal statement.
  5662   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5663     [intro?] and [elim?] (respectively) by default.
  5664   - Experimental command for instantiation of locales in proof contexts:
  5665         instantiate <label>[<attrs>]: <loc>
  5666     Instantiates locale <loc> and adds all its theorems to the current context
  5667     taking into account their attributes.  Label and attrs are optional
  5668     modifiers, like in theorem declarations.  If present, names of
  5669     instantiated theorems are qualified with <label>, and the attributes
  5670     <attrs> are applied after any attributes these theorems might have already.
  5671       If the locale has assumptions, a chained fact of the form
  5672     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5673     are derived.  The command does not support old-style locales declared
  5674     with "locale (open)".
  5675       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5676 
  5677 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5678   (Isar) contexts.
  5679 
  5680 
  5681 *** HOL ***
  5682 
  5683 * Proof import: new image HOL4 contains the imported library from
  5684   the HOL4 system with about 2500 theorems. It is imported by
  5685   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5686   can be used like any other Isabelle image.  See
  5687   HOL/Import/HOL/README for more information.
  5688 
  5689 * Simplifier:
  5690   - Much improved handling of linear and partial orders.
  5691     Reasoners for linear and partial orders are set up for type classes
  5692     "linorder" and "order" respectively, and are added to the default simpset
  5693     as solvers.  This means that the simplifier can build transitivity chains
  5694     to solve goals from the assumptions.
  5695   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5696     of blast or auto after simplification become unnecessary because the goal
  5697     is solved by simplification already.
  5698 
  5699 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5700     all proved in axiomatic type classes for semirings, rings and fields.
  5701 
  5702 * Numerics:
  5703   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5704     now formalized using the Ring_and_Field theory mentioned above.
  5705   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5706     than before, because now they are set up once in a generic manner.
  5707   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5708     Look for the general versions in Ring_and_Field (and Power if they concern
  5709     exponentiation).
  5710 
  5711 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5712 
  5713 * Records:
  5714   - Record types are now by default printed with their type abbreviation
  5715     instead of the list of all field types. This can be configured via
  5716     the reference "print_record_type_abbr".
  5717   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5718     (not enabled by default).
  5719   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5720     EX x. x = sel r to True (not enabled by default).
  5721   - Tactic "record_split_simp_tac" to split and simplify records added.
  5722 
  5723 * 'specification' command added, allowing for definition by
  5724   specification.  There is also an 'ax_specification' command that
  5725   introduces the new constants axiomatically.
  5726 
  5727 * arith(_tac) is now able to generate counterexamples for reals as well.
  5728 
  5729 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5730 
  5731 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5732   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5733 
  5734 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5735   matrix theory to linear programming.
  5736 
  5737 * Unions and Intersections:
  5738   The latex output syntax of UN and INT has been changed
  5739   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5740   i.e. the index formulae has become a subscript.
  5741   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5742 
  5743 * Unions and Intersections over Intervals:
  5744   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5745   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5746   like in normal math, and corresponding versions for < and for intersection.
  5747 
  5748 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5749   lexicographic dictonary ordering has been added as "lexord".
  5750 
  5751 * ML: the legacy theory structures Int and List have been removed. They had
  5752   conflicted with ML Basis Library structures having the same names.
  5753 
  5754 * 'refute' command added to search for (finite) countermodels.  Only works
  5755   for a fragment of HOL.  The installation of an external SAT solver is
  5756   highly recommended.  See "HOL/Refute.thy" for details.
  5757 
  5758 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5759   formulae under an assignment of free variables to random values.
  5760   In contrast to 'refute', it can deal with inductive datatypes,
  5761   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5762   for examples.
  5763 
  5764 
  5765 *** HOLCF ***
  5766 
  5767 * Streams now come with concatenation and are part of the HOLCF image
  5768 
  5769 
  5770 
  5771 New in Isabelle2003 (May 2003)
  5772 ------------------------------
  5773 
  5774 *** General ***
  5775 
  5776 * Provers/simplifier:
  5777 
  5778   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5779     Assumptions are now subject to complete mutual simplification,
  5780     not just from left to right. The simplifier now preserves
  5781     the order of assumptions.
  5782 
  5783     Potential INCOMPATIBILITY:
  5784 
  5785     -- simp sometimes diverges where the old version did
  5786        not, e.g. invoking simp on the goal
  5787 
  5788         [| P (f x); y = x; f x = f y |] ==> Q
  5789 
  5790        now gives rise to the infinite reduction sequence
  5791 
  5792         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5793 
  5794        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5795        kind of problem.
  5796 
  5797     -- Tactics combining classical reasoner and simplification (such as auto)
  5798        are also affected by this change, because many of them rely on
  5799        simp. They may sometimes diverge as well or yield a different numbers
  5800        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5801        in case of problems. Sometimes subsequent calls to the classical
  5802        reasoner will fail because a preceeding call to the simplifier too
  5803        eagerly simplified the goal, e.g. deleted redundant premises.
  5804 
  5805   - The simplifier trace now shows the names of the applied rewrite rules
  5806 
  5807   - You can limit the number of recursive invocations of the simplifier
  5808     during conditional rewriting (where the simplifie tries to solve the
  5809     conditions before applying the rewrite rule):
  5810     ML "simp_depth_limit := n"
  5811     where n is an integer. Thus you can force termination where previously
  5812     the simplifier would diverge.
  5813 
  5814   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5815 
  5816   - No longer aborts on failed congruence proof.  Instead, the
  5817     congruence is ignored.
  5818 
  5819 * Pure: New generic framework for extracting programs from constructive
  5820   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5821   as HOL/Extraction for some case studies.
  5822 
  5823 * Pure: The main goal of the proof state is no longer shown by default, only
  5824 the subgoals. This behaviour is controlled by a new flag.
  5825    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5826 (ML: Proof.show_main_goal).
  5827 
  5828 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5829 rules whose conclusion matches subgoal 1:
  5830       PG menu: Isabelle/Isar -> Show me -> matching rules
  5831 The rules are ordered by how closely they match the subgoal.
  5832 In particular, rules that solve a subgoal outright are displayed first
  5833 (or rather last, the way they are printed).
  5834 (ML: ProofGeneral.print_intros())
  5835 
  5836 * Pure: New flag trace_unify_fail causes unification to print
  5837 diagnostic information (PG: in trace buffer) when it fails. This is
  5838 useful for figuring out why single step proofs like rule, erule or
  5839 assumption failed.
  5840 
  5841 * Pure: Locale specifications now produce predicate definitions
  5842 according to the body of text (covering assumptions modulo local
  5843 definitions); predicate "loc_axioms" covers newly introduced text,
  5844 while "loc" is cumulative wrt. all included locale expressions; the
  5845 latter view is presented only on export into the global theory
  5846 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5847 on the old view without predicates;
  5848 
  5849 * Pure: predefined locales "var" and "struct" are useful for sharing
  5850 parameters (as in CASL, for example); just specify something like
  5851 ``var x + var y + struct M'' as import;
  5852 
  5853 * Pure: improved thms_containing: proper indexing of facts instead of
  5854 raw theorems; check validity of results wrt. current name space;
  5855 include local facts of proof configuration (also covers active
  5856 locales), cover fixed variables in index; may use "_" in term
  5857 specification; an optional limit for the number of printed facts may
  5858 be given (the default is 40);
  5859 
  5860 * Pure: disallow duplicate fact bindings within new-style theory files
  5861 (batch-mode only);
  5862 
  5863 * Provers: improved induct method: assumptions introduced by case
  5864 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5865 the goal statement); "foo" still refers to all facts collectively;
  5866 
  5867 * Provers: the function blast.overloaded has been removed: all constants
  5868 are regarded as potentially overloaded, which improves robustness in exchange
  5869 for slight decrease in efficiency;
  5870 
  5871 * Provers/linorder: New generic prover for transitivity reasoning over
  5872 linear orders.  Note: this prover is not efficient!
  5873 
  5874 * Isar: preview of problems to finish 'show' now produce an error
  5875 rather than just a warning (in interactive mode);
  5876 
  5877 
  5878 *** HOL ***
  5879 
  5880 * arith(_tac)
  5881 
  5882  - Produces a counter example if it cannot prove a goal.
  5883    Note that the counter example may be spurious if the goal is not a formula
  5884    of quantifier-free linear arithmetic.
  5885    In ProofGeneral the counter example appears in the trace buffer.
  5886 
  5887  - Knows about div k and mod k where k is a numeral of type nat or int.
  5888 
  5889  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5890    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5891    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5892 
  5893 * simp's arithmetic capabilities have been enhanced a bit: it now
  5894 takes ~= in premises into account (by performing a case split);
  5895 
  5896 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5897 are distributed over a sum of terms;
  5898 
  5899 * New tactic "trans_tac" and method "trans" instantiate
  5900 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5901 "<=", "<" and "=").
  5902 
  5903 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5904 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5905 
  5906 * 'typedef' command has new option "open" to suppress the set
  5907 definition;
  5908 
  5909 * functions Min and Max on finite sets have been introduced (theory
  5910 Finite_Set);
  5911 
  5912 * attribute [symmetric] now works for relations as well; it turns
  5913 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5914 
  5915 * induct over a !!-quantified statement (say !!x1..xn):
  5916   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5917 
  5918 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5919 %x. None. Warning: empty_def now refers to the previously hidden definition
  5920 of the empty set.
  5921 
  5922 * Algebra: formalization of classical algebra.  Intended as base for
  5923 any algebraic development in Isabelle.  Currently covers group theory
  5924 (up to Sylow's theorem) and ring theory (Universal Property of
  5925 Univariate Polynomials).  Contributions welcome;
  5926 
  5927 * GroupTheory: deleted, since its material has been moved to Algebra;
  5928 
  5929 * Complex: new directory of the complex numbers with numeric constants,
  5930 nonstandard complex numbers, and some complex analysis, standard and
  5931 nonstandard (Jacques Fleuriot);
  5932 
  5933 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5934 
  5935 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5936 Fleuriot);
  5937 
  5938 * Real/HahnBanach: updated and adapted to locales;
  5939 
  5940 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5941 Gray and Kramer);
  5942 
  5943 * UNITY: added the Meier-Sanders theory of progress sets;
  5944 
  5945 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5946 as abstract algorithms, instantiated to the JVM;
  5947 
  5948 * Bali: Java source language formalization. Type system, operational
  5949 semantics, axiomatic semantics. Supported language features:
  5950 classes, interfaces, objects,virtual methods, static methods,
  5951 static/instance fields, arrays, access modifiers, definite
  5952 assignment, exceptions.
  5953 
  5954 
  5955 *** ZF ***
  5956 
  5957 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5958 universe, etc.);
  5959 
  5960 * Main ZF: virtually all theories converted to new-style format;
  5961 
  5962 
  5963 *** ML ***
  5964 
  5965 * Pure: Tactic.prove provides sane interface for internal proofs;
  5966 omits the infamous "standard" operation, so this is more appropriate
  5967 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5968 
  5969 * Pure: improved error reporting of simprocs;
  5970 
  5971 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5972 up simprocs;
  5973 
  5974 
  5975 *** Document preparation ***
  5976 
  5977 * uses \par instead of \\ for line breaks in theory text. This may
  5978 shift some page breaks in large documents. To get the old behaviour
  5979 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5980 
  5981 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5982 other packages
  5983 
  5984 * \<euro> now needs package babel/greek instead of marvosym (which
  5985 broke \Rightarrow)
  5986 
  5987 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5988 textcomp package)
  5989 
  5990 
  5991 
  5992 New in Isabelle2002 (March 2002)
  5993 --------------------------------
  5994 
  5995 *** Document preparation ***
  5996 
  5997 * greatly simplified document preparation setup, including more
  5998 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5999 instructive isatool mkdir; users should basically be able to get
  6000 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6001 users may run a separate document processing stage manually like this:
  6002 "isatool usedir -D output HOL Test && isatool document Test/output";
  6003 
  6004 * theory dependency graph may now be incorporated into documents;
  6005 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6006 with \includegraphics of LaTeX;
  6007 
  6008 * proper spacing of consecutive markup elements, especially text
  6009 blocks after section headings;
  6010 
  6011 * support bold style (for single symbols only), input syntax is like
  6012 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6013 
  6014 * \<bullet> is now output as bold \cdot by default, which looks much
  6015 better in printed text;
  6016 
  6017 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6018 note that these symbols are currently unavailable in Proof General /
  6019 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6020 
  6021 * isatool latex no longer depends on changed TEXINPUTS, instead
  6022 isatool document copies the Isabelle style files to the target
  6023 location;
  6024 
  6025 
  6026 *** Isar ***
  6027 
  6028 * Pure/Provers: improved proof by cases and induction;
  6029   - 'case' command admits impromptu naming of parameters (such as
  6030     "case (Suc n)");
  6031   - 'induct' method divinates rule instantiation from the inductive
  6032     claim; no longer requires excessive ?P bindings for proper
  6033     instantiation of cases;
  6034   - 'induct' method properly enumerates all possibilities of set/type
  6035     rules; as a consequence facts may be also passed through *type*
  6036     rules without further ado;
  6037   - 'induct' method now derives symbolic cases from the *rulified*
  6038     rule (before it used to rulify cases stemming from the internal
  6039     atomized version); this means that the context of a non-atomic
  6040     statement becomes is included in the hypothesis, avoiding the
  6041     slightly cumbersome show "PROP ?case" form;
  6042   - 'induct' may now use elim-style induction rules without chaining
  6043     facts, using ``missing'' premises from the goal state; this allows
  6044     rules stemming from inductive sets to be applied in unstructured
  6045     scripts, while still benefitting from proper handling of non-atomic
  6046     statements; NB: major inductive premises need to be put first, all
  6047     the rest of the goal is passed through the induction;
  6048   - 'induct' proper support for mutual induction involving non-atomic
  6049     rule statements (uses the new concept of simultaneous goals, see
  6050     below);
  6051   - append all possible rule selections, but only use the first
  6052     success (no backtracking);
  6053   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6054   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6055   - added 'print_induct_rules' (covered by help item in recent Proof
  6056     General versions);
  6057   - moved induct/cases attributes to Pure, methods to Provers;
  6058   - generic method setup instantiated for FOL and HOL;
  6059 
  6060 * Pure: support multiple simultaneous goal statements, for example
  6061 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6062 meta-level mechanism, this acts as if several individual goals had
  6063 been stated separately; in particular common proof methods need to be
  6064 repeated in order to cover all claims; note that a single elimination
  6065 step is *not* sufficient to establish the two conjunctions, so this
  6066 fails:
  6067 
  6068   assume "A & B" then have A and B ..   (*".." fails*)
  6069 
  6070 better use "obtain" in situations as above; alternative refer to
  6071 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6072 
  6073 * Pure: proper integration with ``locales''; unlike the original
  6074 version by Florian Kammller, Isar locales package high-level proof
  6075 contexts rather than raw logical ones (e.g. we admit to include
  6076 attributes everywhere); operations on locales include merge and
  6077 rename; support for implicit arguments (``structures''); simultaneous
  6078 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6079 some examples;
  6080 
  6081 * Pure: the following commands have been ``localized'', supporting a
  6082 target locale specification "(in name)": 'lemma', 'theorem',
  6083 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6084 stored both within the locale and at the theory level (exported and
  6085 qualified by the locale name);
  6086 
  6087 * Pure: theory goals may now be specified in ``long'' form, with
  6088 ad-hoc contexts consisting of arbitrary locale elements. for example
  6089 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6090 definitions may be given, too); the result is a meta-level rule with
  6091 the context elements being discharged in the obvious way;
  6092 
  6093 * Pure: new proof command 'using' allows to augment currently used
  6094 facts after a goal statement ('using' is syntactically analogous to
  6095 'apply', but acts on the goal's facts only); this allows chained facts
  6096 to be separated into parts given before and after a claim, as in
  6097 ``from a and b have C using d and e <proof>'';
  6098 
  6099 * Pure: renamed "antecedent" case to "rule_context";
  6100 
  6101 * Pure: new 'judgment' command records explicit information about the
  6102 object-logic embedding (used by several tools internally); no longer
  6103 use hard-wired "Trueprop";
  6104 
  6105 * Pure: added 'corollary' command;
  6106 
  6107 * Pure: fixed 'token_translation' command;
  6108 
  6109 * Pure: removed obsolete 'exported' attribute;
  6110 
  6111 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6112 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6113 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6114 
  6115 * Pure: method 'atomize' presents local goal premises as object-level
  6116 statements (atomic meta-level propositions); setup controlled via
  6117 rewrite rules declarations of 'atomize' attribute; example
  6118 application: 'induct' method with proper rule statements in improper
  6119 proof *scripts*;
  6120 
  6121 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6122 now consider the syntactic context of assumptions, giving a better
  6123 chance to get type-inference of the arguments right (this is
  6124 especially important for locales);
  6125 
  6126 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6127 mode;
  6128 
  6129 * Pure/obtain: the formal conclusion "thesis", being marked as
  6130 ``internal'', may no longer be reference directly in the text;
  6131 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6132 situations;
  6133 
  6134 * Pure: generic 'sym' attribute which declares a rule both as pure
  6135 'elim?' and for the 'symmetric' operation;
  6136 
  6137 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6138 text; the fixed correlation with particular command syntax has been
  6139 discontinued;
  6140 
  6141 * Pure: new method 'rules' is particularly well-suited for proof
  6142 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6143 but often produces more compact proof terms with less detours;
  6144 
  6145 * Pure/Provers/classical: simplified integration with pure rule
  6146 attributes and methods; the classical "intro?/elim?/dest?"
  6147 declarations coincide with the pure ones; the "rule" method no longer
  6148 includes classically swapped intros; "intro" and "elim" methods no
  6149 longer pick rules from the context; also got rid of ML declarations
  6150 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6151 INCOMPATIBILITY;
  6152 
  6153 * Provers/classical: attribute 'swapped' produces classical inversions
  6154 of introduction rules;
  6155 
  6156 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6157 rules instead of full simplifier context; 'iff' attribute handles
  6158 conditional rules;
  6159 
  6160 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6161 
  6162 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6163 "(permissive)" option to recover old behavior;
  6164 
  6165 * HOL: 'inductive' no longer features separate (collective) attributes
  6166 for 'intros' (was found too confusing);
  6167 
  6168 * HOL: properly declared induction rules less_induct and
  6169 wf_induct_rule;
  6170 
  6171 
  6172 *** HOL ***
  6173 
  6174 * HOL: moved over to sane numeral syntax; the new policy is as
  6175 follows:
  6176 
  6177   - 0 and 1 are polymorphic constants, which are defined on any
  6178   numeric type (nat, int, real etc.);
  6179 
  6180   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6181   binary representation internally;
  6182 
  6183   - type nat has special constructor Suc, and generally prefers Suc 0
  6184   over 1::nat and Suc (Suc 0) over 2::nat;
  6185 
  6186 This change may cause significant problems of INCOMPATIBILITY; here
  6187 are some hints on converting existing sources:
  6188 
  6189   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6190   entities, so expressions involving "-" (unary or binary minus) need
  6191   to be spaced properly;
  6192 
  6193   - existing occurrences of "1" may need to be constraint "1::nat" or
  6194   even replaced by Suc 0; similar for old "2";
  6195 
  6196   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6197 
  6198   - remove all special provisions on numerals in proofs;
  6199 
  6200 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6201 representation (depends on bin_arith_simps in the default context);
  6202 
  6203 * HOL: symbolic syntax for x^2 (numeral 2);
  6204 
  6205 * HOL: the class of all HOL types is now called "type" rather than
  6206 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6207 in axclass/classes, instance/arities, and (usually rare) occurrences
  6208 in typings (of consts etc.); internally the class is called
  6209 "HOL.type", ML programs should refer to HOLogic.typeS;
  6210 
  6211 * HOL/record package improvements:
  6212   - new derived operations "fields" to build a partial record section,
  6213     "extend" to promote a fixed record to a record scheme, and
  6214     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6215     declared as simp by default;
  6216   - shared operations ("more", "fields", etc.) now need to be always
  6217     qualified) --- potential INCOMPATIBILITY;
  6218   - removed "make_scheme" operations (use "make" with "extend") --
  6219     INCOMPATIBILITY;
  6220   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6221   - provides cases/induct rules for use with corresponding Isar
  6222     methods (for concrete records, record schemes, concrete more
  6223     parts, and schematic more parts -- in that order);
  6224   - internal definitions directly based on a light-weight abstract
  6225     theory of product types over typedef rather than datatype;
  6226 
  6227 * HOL: generic code generator for generating executable ML code from
  6228 specifications; specific support for HOL constructs such as inductive
  6229 datatypes and sets, as well as recursive functions; can be invoked
  6230 via 'generate_code' theory section;
  6231