NEWS
author wenzelm
Tue May 03 18:04:05 2011 +0200 (2011-05-03)
changeset 42658 8f5d5d71add0
parent 42633 f86467c5a72c
child 42669 04dfffda5671
permissions -rw-r--r--
some documentation of @{rail} antiquotation;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) is has been
    26 discontinued.  INCOMPATIBILITY.
    27 
    28 * Various optional external tools are referenced more robustly and
    29 uniformly by explicit Isabelle settings as follows:
    30 
    31   ISABELLE_CSDP   (formerly CSDP_EXE)
    32   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    33   ISABELLE_OCAML  (formerly EXEC_OCAML)
    34   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    35   ISABELLE_YAP    (formerly EXEC_YAP)
    36 
    37 Note that automated detection from the file-system or search path has
    38 been discontinued.  INCOMPATIBILITY.
    39 
    40 * Name space: proper configuration options "long_names",
    41 "short_names", "unique_names" instead of former unsynchronized
    42 references.  Minor INCOMPATIBILITY, need to declare options in context
    43 like this:
    44 
    45   declare [[unique_names = false]]
    46 
    47 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    48 that the result needs to be unique, which means fact specifications
    49 may have to be refined after enriching a proof context.
    50 
    51 * Isabelle/Isar reference manual provides more formal references in
    52 syntax diagrams.
    53 
    54 
    55 *** HOL ***
    56 
    57 * Nitpick:
    58   - Added "need" and "total_consts" options.
    59   - Reintroduced "show_skolems" option by popular demand.
    60   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    61     INCOMPATIBILITY.
    62 
    63 * Sledgehammer:
    64   - sledgehammer available_provers ~> sledgehammer supported_provers
    65     INCOMPATIBILITY.
    66   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    67     TPTP problems (TFF).
    68   - Added "type_sys" and "monomorphize_limit" options.
    69 
    70 * "try":
    71   - Added "simp:", "intro:", and "elim:" options.
    72 
    73 * Quickcheck:
    74   - Added "eval" option to evaluate terms for the found counterexample
    75     (currently only supported by the default (exhaustive) tester)
    76   - Added post-processing of terms to obtain readable counterexamples
    77     (currently only supported by the default (exhaustive) tester)
    78 
    79 * Function package: discontinued option "tailrec".
    80 INCOMPATIBILITY. Use partial_function instead.
    81 
    82 * HOL-Probability:
    83   - Caratheodory's extension lemma is now proved for ring_of_sets.
    84   - Infinite products of probability measures are now available.
    85   - Use extended reals instead of positive extended reals.
    86     INCOMPATIBILITY.
    87 
    88 
    89 *** Document preparation ***
    90 
    91 * Antiquotation @{rail} layouts railroad syntax diagrams; requires
    92 railsetup.sty included in the Isabelle distribution; see also isar-ref
    93 manual.
    94 
    95 * Localized \isabellestyle switch can be used within blocks or groups
    96 like this:
    97 
    98   \isabellestyle{it}  %preferred default
    99   {\isabellestylett @{text "typewriter stuff"}}
   100 
   101 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   102 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   103 
   104 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   105 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   106 
   107 
   108 *** ML ***
   109 
   110 * Structure Proof_Context follows standard naming scheme.  Old
   111 ProofContext is still available for some time as legacy alias.
   112 
   113 * Structure Timing provides various operations for timing; supersedes
   114 former start_timing/end_timing etc.
   115 
   116 * Path.print is the official way to show file-system paths to users
   117 (including quotes etc.).
   118 
   119 * Inner syntax: identifiers in parse trees of generic categories
   120 "logic", "aprop", "idt" etc. carry position information (disguised as
   121 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   122 translations that choke on unexpected type constraints.  Positions can
   123 be stripped in ML translations via Syntax.strip_positions /
   124 Syntax.strip_positions_ast, or via the syntax constant
   125 "_strip_positions" within parse trees.  As last resort, positions can
   126 be disabled via the configuration option Syntax.positions, which is
   127 called "syntax_positions" in Isar attribute syntax.
   128 
   129 * Discontinued special status of various ML structures that contribute
   130 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   131 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   132 refer directly to Ast.Constant, Lexicon.is_identifier,
   133 Syntax_Trans.mk_binder_tr etc.
   134 
   135 * Typed print translation: discontinued show_sorts argument, which is
   136 already available via context of "advanced" translation.
   137 
   138 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   139 goal states; body tactic needs to address all subgoals uniformly.
   140 
   141 * Slightly more special eq_list/eq_set, with shortcut involving
   142 pointer equality (assumes that eq relation is reflexive).
   143 
   144 
   145 
   146 New in Isabelle2011 (January 2011)
   147 ----------------------------------
   148 
   149 *** General ***
   150 
   151 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   152 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   153 useful tooltips and hyperlinks produced from its static analysis.  The
   154 bundled component provides an executable Isabelle tool that can be run
   155 like this:
   156 
   157   Isabelle2011/bin/isabelle jedit
   158 
   159 * Significantly improved Isabelle/Isar implementation manual.
   160 
   161 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   162 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   163 while the default heap location within that directory lacks that extra
   164 suffix.  This isolates multiple Isabelle installations from each
   165 other, avoiding problems with old settings in new versions.
   166 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   167 
   168 * Source files are always encoded as UTF-8, instead of old-fashioned
   169 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   170 the following package declarations:
   171 
   172   \usepackage[utf8]{inputenc}
   173   \usepackage{textcomp}
   174 
   175 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   176 a Unicode character is treated as a single symbol, not a sequence of
   177 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   178 contain symbols without further backslash escapes, Unicode can now be
   179 used here as well.  Recall that Symbol.explode in ML provides a
   180 consistent view on symbols, while raw explode (or String.explode)
   181 merely give a byte-oriented representation.
   182 
   183 * Theory loader: source files are primarily located via the master
   184 directory of each theory node (where the .thy file itself resides).
   185 The global load path is still partially available as legacy feature.
   186 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   187 explicit paths, relatively to the theory.
   188 
   189 * Special treatment of ML file names has been discontinued.
   190 Historically, optional extensions .ML or .sml were added on demand --
   191 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   192 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   193 
   194 * Various options that affect pretty printing etc. are now properly
   195 handled within the context via configuration options, instead of
   196 unsynchronized references or print modes.  There are both ML Config.T
   197 entities and Isar declaration attributes to access these.
   198 
   199   ML (Config.T)                 Isar (attribute)
   200 
   201   eta_contract                  eta_contract
   202   show_brackets                 show_brackets
   203   show_sorts                    show_sorts
   204   show_types                    show_types
   205   show_question_marks           show_question_marks
   206   show_consts                   show_consts
   207   show_abbrevs                  show_abbrevs
   208 
   209   Syntax.ast_trace              syntax_ast_trace
   210   Syntax.ast_stat               syntax_ast_stat
   211   Syntax.ambiguity_level        syntax_ambiguity_level
   212 
   213   Goal_Display.goals_limit      goals_limit
   214   Goal_Display.show_main_goal   show_main_goal
   215 
   216   Method.rule_trace             rule_trace
   217 
   218   Thy_Output.display            thy_output_display
   219   Thy_Output.quotes             thy_output_quotes
   220   Thy_Output.indent             thy_output_indent
   221   Thy_Output.source             thy_output_source
   222   Thy_Output.break              thy_output_break
   223 
   224 Note that corresponding "..._default" references in ML may only be
   225 changed globally at the ROOT session setup, but *not* within a theory.
   226 The option "show_abbrevs" supersedes the former print mode
   227 "no_abbrevs" with inverted meaning.
   228 
   229 * More systematic naming of some configuration options.
   230 INCOMPATIBILITY.
   231 
   232   trace_simp  ~>  simp_trace
   233   debug_simp  ~>  simp_debug
   234 
   235 * Support for real valued configuration options, using simplistic
   236 floating-point notation that coincides with the inner syntax for
   237 float_token.
   238 
   239 * Support for real valued preferences (with approximative PGIP type):
   240 front-ends need to accept "pgint" values in float notation.
   241 INCOMPATIBILITY.
   242 
   243 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   244 DejaVu Sans.
   245 
   246 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   247 
   248 
   249 *** Pure ***
   250 
   251 * Command 'type_synonym' (with single argument) replaces somewhat
   252 outdated 'types', which is still available as legacy feature for some
   253 time.
   254 
   255 * Command 'nonterminal' (with 'and' separated list of arguments)
   256 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   257 
   258 * Command 'notepad' replaces former 'example_proof' for
   259 experimentation in Isar without any result.  INCOMPATIBILITY.
   260 
   261 * Locale interpretation commands 'interpret' and 'sublocale' accept
   262 lists of equations to map definitions in a locale to appropriate
   263 entities in the context of the interpretation.  The 'interpretation'
   264 command already provided this functionality.
   265 
   266 * Diagnostic command 'print_dependencies' prints the locale instances
   267 that would be activated if the specified expression was interpreted in
   268 the current context.  Variant "print_dependencies!" assumes a context
   269 without interpretations.
   270 
   271 * Diagnostic command 'print_interps' prints interpretations in proofs
   272 in addition to interpretations in theories.
   273 
   274 * Discontinued obsolete 'global' and 'local' commands to manipulate
   275 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   276 Sign.root_path and Sign.local_path may be applied directly where this
   277 feature is still required for historical reasons.
   278 
   279 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   280 'definition' instead.
   281 
   282 * The "prems" fact, which refers to the accidental collection of
   283 foundational premises in the context, is now explicitly marked as
   284 legacy feature and will be discontinued soon.  Consider using "assms"
   285 of the head statement or reference facts by explicit names.
   286 
   287 * Document antiquotations @{class} and @{type} print classes and type
   288 constructors.
   289 
   290 * Document antiquotation @{file} checks file/directory entries within
   291 the local file system.
   292 
   293 
   294 *** HOL ***
   295 
   296 * Coercive subtyping: functions can be declared as coercions and type
   297 inference will add them as necessary upon input of a term.  Theory
   298 Complex_Main declares real :: nat => real and real :: int => real as
   299 coercions. A coercion function f is declared like this:
   300 
   301   declare [[coercion f]]
   302 
   303 To lift coercions through type constructors (e.g. from nat => real to
   304 nat list => real list), map functions can be declared, e.g.
   305 
   306   declare [[coercion_map map]]
   307 
   308 Currently coercion inference is activated only in theories including
   309 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   310 the configuration option "coercion_enabled", e.g. it can be enabled in
   311 other theories like this:
   312 
   313   declare [[coercion_enabled]]
   314 
   315 * Command 'partial_function' provides basic support for recursive
   316 function definitions over complete partial orders.  Concrete instances
   317 are provided for i) the option type, ii) tail recursion on arbitrary
   318 types, and iii) the heap monad of Imperative_HOL.  See
   319 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   320 for examples.
   321 
   322 * Function package: f.psimps rules are no longer implicitly declared
   323 as [simp].  INCOMPATIBILITY.
   324 
   325 * Datatype package: theorems generated for executable equality (class
   326 "eq") carry proper names and are treated as default code equations.
   327 
   328 * Inductive package: now offers command 'inductive_simps' to
   329 automatically derive instantiated and simplified equations for
   330 inductive predicates, similar to 'inductive_cases'.
   331 
   332 * Command 'enriched_type' allows to register properties of the
   333 functorial structure of types.
   334 
   335 * Improved infrastructure for term evaluation using code generator
   336 techniques, in particular static evaluation conversions.
   337 
   338 * Code generator: Scala (2.8 or higher) has been added to the target
   339 languages.
   340 
   341 * Code generator: globbing constant expressions "*" and "Theory.*"
   342 have been replaced by the more idiomatic "_" and "Theory._".
   343 INCOMPATIBILITY.
   344 
   345 * Code generator: export_code without explicit file declaration prints
   346 to standard output.  INCOMPATIBILITY.
   347 
   348 * Code generator: do not print function definitions for case
   349 combinators any longer.
   350 
   351 * Code generator: simplification with rules determined with
   352 src/Tools/Code/code_simp.ML and method "code_simp".
   353 
   354 * Code generator for records: more idiomatic representation of record
   355 types.  Warning: records are not covered by ancient SML code
   356 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   357 rep_datatype declaration helps to succeed then:
   358 
   359   record 'a foo = ...
   360   ...
   361   rep_datatype foo_ext ...
   362 
   363 * Records: logical foundation type for records does not carry a
   364 '_type' suffix any longer (obsolete due to authentic syntax).
   365 INCOMPATIBILITY.
   366 
   367 * Quickcheck now by default uses exhaustive testing instead of random
   368 testing.  Random testing can be invoked by "quickcheck [random]",
   369 exhaustive testing by "quickcheck [exhaustive]".
   370 
   371 * Quickcheck instantiates polymorphic types with small finite
   372 datatypes by default. This enables a simple execution mechanism to
   373 handle quantifiers and function equality over the finite datatypes.
   374 
   375 * Quickcheck random generator has been renamed from "code" to
   376 "random".  INCOMPATIBILITY.
   377 
   378 * Quickcheck now has a configurable time limit which is set to 30
   379 seconds by default. This can be changed by adding [timeout = n] to the
   380 quickcheck command. The time limit for Auto Quickcheck is still set
   381 independently.
   382 
   383 * Quickcheck in locales considers interpretations of that locale for
   384 counter example search.
   385 
   386 * Sledgehammer:
   387   - Added "smt" and "remote_smt" provers based on the "smt" proof
   388     method. See the Sledgehammer manual for details ("isabelle doc
   389     sledgehammer").
   390   - Renamed commands:
   391     sledgehammer atp_info ~> sledgehammer running_provers
   392     sledgehammer atp_kill ~> sledgehammer kill_provers
   393     sledgehammer available_atps ~> sledgehammer available_provers
   394     INCOMPATIBILITY.
   395   - Renamed options:
   396     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   397     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   398     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   399     (and "ms" and "min" are no longer supported)
   400     INCOMPATIBILITY.
   401 
   402 * Nitpick:
   403   - Renamed options:
   404     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   405     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   406     INCOMPATIBILITY.
   407   - Added support for partial quotient types.
   408   - Added local versions of the "Nitpick.register_xxx" functions.
   409   - Added "whack" option.
   410   - Allow registration of quotient types as codatatypes.
   411   - Improved "merge_type_vars" option to merge more types.
   412   - Removed unsound "fast_descrs" option.
   413   - Added custom symmetry breaking for datatypes, making it possible to reach
   414     higher cardinalities.
   415   - Prevent the expansion of too large definitions.
   416 
   417 * Proof methods "metis" and "meson" now have configuration options
   418 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   419 to diagnose these tools. E.g.
   420 
   421     using [[metis_trace = true]]
   422 
   423 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   424 manually as command 'solve_direct'.
   425 
   426 * The default SMT solver Z3 must be enabled explicitly (due to
   427 licensing issues) by setting the environment variable
   428 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   429 commercial applications, the SMT solver CVC3 is provided as fall-back;
   430 changing the SMT solver is done via the configuration option
   431 "smt_solver".
   432 
   433 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   434 i.e. "remote_cvc3" and "remote_z3".
   435 
   436 * Added basic SMT support for datatypes, records, and typedefs using
   437 the oracle mode (no proofs).  Direct support of pairs has been dropped
   438 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   439 support for a similar behavior).  Minor INCOMPATIBILITY.
   440 
   441 * Changed SMT configuration options:
   442   - Renamed:
   443     z3_proofs ~> smt_oracle (with inverted meaning)
   444     z3_trace_assms ~> smt_trace_used_facts
   445     INCOMPATIBILITY.
   446   - Added:
   447     smt_verbose
   448     smt_random_seed
   449     smt_datatypes
   450     smt_infer_triggers
   451     smt_monomorph_limit
   452     cvc3_options
   453     remote_cvc3_options
   454     remote_z3_options
   455     yices_options
   456 
   457 * Boogie output files (.b2i files) need to be declared in the theory
   458 header.
   459 
   460 * Simplification procedure "list_to_set_comprehension" rewrites list
   461 comprehensions applied to List.set to set comprehensions.  Occasional
   462 INCOMPATIBILITY, may be deactivated like this:
   463 
   464   declare [[simproc del: list_to_set_comprehension]]
   465 
   466 * Removed old version of primrec package.  INCOMPATIBILITY.
   467 
   468 * Removed simplifier congruence rule of "prod_case", as has for long
   469 been the case with "split".  INCOMPATIBILITY.
   470 
   471 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   472 
   473 * Removed [split_format ... and ... and ...] version of
   474 [split_format].  Potential INCOMPATIBILITY.
   475 
   476 * Predicate "sorted" now defined inductively, with nice induction
   477 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   478 
   479 * Constant "contents" renamed to "the_elem", to free the generic name
   480 contents for other uses.  INCOMPATIBILITY.
   481 
   482 * Renamed class eq and constant eq (for code generation) to class
   483 equal and constant equal, plus renaming of related facts and various
   484 tuning.  INCOMPATIBILITY.
   485 
   486 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   487 
   488 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   489 INCOMPATIBILITY.
   490 
   491 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   492 avoid confusion with finite sets.  INCOMPATIBILITY.
   493 
   494 * Abandoned locales equiv, congruent and congruent2 for equivalence
   495 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   496 for congruent(2)).
   497 
   498 * Some previously unqualified names have been qualified:
   499 
   500   types
   501     bool ~> HOL.bool
   502     nat ~> Nat.nat
   503 
   504   constants
   505     Trueprop ~> HOL.Trueprop
   506     True ~> HOL.True
   507     False ~> HOL.False
   508     op & ~> HOL.conj
   509     op | ~> HOL.disj
   510     op --> ~> HOL.implies
   511     op = ~> HOL.eq
   512     Not ~> HOL.Not
   513     The ~> HOL.The
   514     All ~> HOL.All
   515     Ex ~> HOL.Ex
   516     Ex1 ~> HOL.Ex1
   517     Let ~> HOL.Let
   518     If ~> HOL.If
   519     Ball ~> Set.Ball
   520     Bex ~> Set.Bex
   521     Suc ~> Nat.Suc
   522     Pair ~> Product_Type.Pair
   523     fst ~> Product_Type.fst
   524     snd ~> Product_Type.snd
   525     curry ~> Product_Type.curry
   526     op : ~> Set.member
   527     Collect ~> Set.Collect
   528 
   529 INCOMPATIBILITY.
   530 
   531 * More canonical naming convention for some fundamental definitions:
   532 
   533     bot_bool_eq ~> bot_bool_def
   534     top_bool_eq ~> top_bool_def
   535     inf_bool_eq ~> inf_bool_def
   536     sup_bool_eq ~> sup_bool_def
   537     bot_fun_eq  ~> bot_fun_def
   538     top_fun_eq  ~> top_fun_def
   539     inf_fun_eq  ~> inf_fun_def
   540     sup_fun_eq  ~> sup_fun_def
   541 
   542 INCOMPATIBILITY.
   543 
   544 * More stylized fact names:
   545 
   546   expand_fun_eq ~> fun_eq_iff
   547   expand_set_eq ~> set_eq_iff
   548   set_ext       ~> set_eqI
   549   nat_number    ~> eval_nat_numeral
   550 
   551 INCOMPATIBILITY.
   552 
   553 * Refactoring of code-generation specific operations in theory List:
   554 
   555   constants
   556     null ~> List.null
   557 
   558   facts
   559     mem_iff ~> member_def
   560     null_empty ~> null_def
   561 
   562 INCOMPATIBILITY.  Note that these were not supposed to be used
   563 regularly unless for striking reasons; their main purpose was code
   564 generation.
   565 
   566 Various operations from the Haskell prelude are used for generating
   567 Haskell code.
   568 
   569 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   570 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   571 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   572 
   573 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   574 "*" and "+" respectively.  INCOMPATIBILITY.
   575 
   576 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   577 "Sum_Type.Plus" instead.
   578 
   579 * Constant "split" has been merged with constant "prod_case"; names of
   580 ML functions, facts etc. involving split have been retained so far,
   581 though.  INCOMPATIBILITY.
   582 
   583 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   584 instead.  INCOMPATIBILITY.
   585 
   586 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   587 INCOMPATIBILITY.
   588 
   589 * Former theory Library/Enum is now part of the HOL-Main image.
   590 INCOMPATIBILITY: all constants of the Enum theory now have to be
   591 referred to by its qualified name.
   592 
   593   enum    ~>  Enum.enum
   594   nlists  ~>  Enum.nlists
   595   product ~>  Enum.product
   596 
   597 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   598 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   599 INCOMPATIBILITY.
   600 
   601 * Theory Library/SetsAndFunctions has been split into
   602 Library/Function_Algebras and Library/Set_Algebras; canonical names
   603 for instance definitions for functions; various improvements.
   604 INCOMPATIBILITY.
   605 
   606 * Theory Library/Multiset provides stable quicksort implementation of
   607 sort_key.
   608 
   609 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   610 INCOMPATIBILITY.
   611 
   612 * Session Multivariate_Analysis: introduced a type class for euclidean
   613 space.  Most theorems are now stated in terms of euclidean spaces
   614 instead of finite cartesian products.
   615 
   616   types
   617     real ^ 'n ~>  'a::real_vector
   618               ~>  'a::euclidean_space
   619               ~>  'a::ordered_euclidean_space
   620         (depends on your needs)
   621 
   622   constants
   623      _ $ _        ~> _ $$ _
   624      \<chi> x. _  ~> \<chi>\<chi> x. _
   625      CARD('n)     ~> DIM('a)
   626 
   627 Also note that the indices are now natural numbers and not from some
   628 finite type. Finite cartesian products of euclidean spaces, products
   629 of euclidean spaces the real and complex numbers are instantiated to
   630 be euclidean_spaces.  INCOMPATIBILITY.
   631 
   632 * Session Probability: introduced pextreal as positive extended real
   633 numbers.  Use pextreal as value for measures.  Introduce the
   634 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   635 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   636 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   637 
   638 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   639 INCOMPATIBILITY.
   640 
   641 * Session SPARK (with image HOL-SPARK) provides commands to load and
   642 prove verification conditions generated by the SPARK Ada program
   643 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   644 
   645 
   646 *** HOL-Algebra ***
   647 
   648 * Theorems for additive ring operations (locale abelian_monoid and
   649 descendants) are generated by interpretation from their multiplicative
   650 counterparts.  Names (in particular theorem names) have the mandatory
   651 qualifier 'add'.  Previous theorem names are redeclared for
   652 compatibility.
   653 
   654 * Structure "int_ring" is now an abbreviation (previously a
   655 definition).  This fits more natural with advanced interpretations.
   656 
   657 
   658 *** HOLCF ***
   659 
   660 * The domain package now runs in definitional mode by default: The
   661 former command 'new_domain' is now called 'domain'.  To use the domain
   662 package in its original axiomatic mode, use 'domain (unsafe)'.
   663 INCOMPATIBILITY.
   664 
   665 * The new class "domain" is now the default sort.  Class "predomain"
   666 is an unpointed version of "domain". Theories can be updated by
   667 replacing sort annotations as shown below.  INCOMPATIBILITY.
   668 
   669   'a::type ~> 'a::countable
   670   'a::cpo  ~> 'a::predomain
   671   'a::pcpo ~> 'a::domain
   672 
   673 * The old type class "rep" has been superseded by class "domain".
   674 Accordingly, users of the definitional package must remove any
   675 "default_sort rep" declarations.  INCOMPATIBILITY.
   676 
   677 * The domain package (definitional mode) now supports unpointed
   678 predomain argument types, as long as they are marked 'lazy'. (Strict
   679 arguments must be in class "domain".) For example, the following
   680 domain definition now works:
   681 
   682   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   683 
   684 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   685 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   686 'a option, and 'a list.  Additionally, it configures fixrec and the
   687 domain package to work with these types.  For example:
   688 
   689   fixrec isInl :: "('a + 'b) u -> tr"
   690     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   691 
   692   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   693 
   694 * The "(permissive)" option of fixrec has been replaced with a
   695 per-equation "(unchecked)" option. See
   696 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   697 
   698 * The "bifinite" class no longer fixes a constant "approx"; the class
   699 now just asserts that such a function exists.  INCOMPATIBILITY.
   700 
   701 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   702 defines an embedding of type 'a defl into udom by default; instances
   703 of "bifinite" and "domain" classes are available in
   704 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   705 
   706 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   707 
   708 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   709 
   710 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   711 
   712 * The function "cprod_map" has been renamed to "prod_map".
   713 INCOMPATIBILITY.
   714 
   715 * The monadic bind operator on each powerdomain has new binder syntax
   716 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   717 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   718 
   719 * The infix syntax for binary union on each powerdomain has changed
   720 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   721 syntax.  INCOMPATIBILITY.
   722 
   723 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   724 still supported as an input translation.
   725 
   726 * Renamed some theorems (the original names are also still available).
   727 
   728   expand_fun_below   ~> fun_below_iff
   729   below_fun_ext      ~> fun_belowI
   730   expand_cfun_eq     ~> cfun_eq_iff
   731   ext_cfun           ~> cfun_eqI
   732   expand_cfun_below  ~> cfun_below_iff
   733   below_cfun_ext     ~> cfun_belowI
   734   cont2cont_Rep_CFun ~> cont2cont_APP
   735 
   736 * The Abs and Rep functions for various types have changed names.
   737 Related theorem names have also changed to match. INCOMPATIBILITY.
   738 
   739   Rep_CFun  ~> Rep_cfun
   740   Abs_CFun  ~> Abs_cfun
   741   Rep_Sprod ~> Rep_sprod
   742   Abs_Sprod ~> Abs_sprod
   743   Rep_Ssum  ~> Rep_ssum
   744   Abs_Ssum  ~> Abs_ssum
   745 
   746 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   747 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   748 
   749 * Various changes to bisimulation/coinduction with domain package:
   750 
   751   - Definitions of "bisim" constants no longer mention definedness.
   752   - With mutual recursion, "bisim" predicate is now curried.
   753   - With mutual recursion, each type gets a separate coind theorem.
   754   - Variable names in bisim_def and coinduct rules have changed.
   755 
   756 INCOMPATIBILITY.
   757 
   758 * Case combinators generated by the domain package for type "foo" are
   759 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   760 
   761 * Several theorems have been renamed to more accurately reflect the
   762 names of constants and types involved.  INCOMPATIBILITY.
   763 
   764   thelub_const    ~> lub_const
   765   lub_const       ~> is_lub_const
   766   thelubI         ~> lub_eqI
   767   is_lub_lub      ~> is_lubD2
   768   lubI            ~> is_lub_lub
   769   unique_lub      ~> is_lub_unique
   770   is_ub_lub       ~> is_lub_rangeD1
   771   lub_bin_chain   ~> is_lub_bin_chain
   772   lub_fun         ~> is_lub_fun
   773   thelub_fun      ~> lub_fun
   774   thelub_cfun     ~> lub_cfun
   775   thelub_Pair     ~> lub_Pair
   776   lub_cprod       ~> is_lub_prod
   777   thelub_cprod    ~> lub_prod
   778   minimal_cprod   ~> minimal_prod
   779   inst_cprod_pcpo ~> inst_prod_pcpo
   780   UU_I            ~> bottomI
   781   compact_UU      ~> compact_bottom
   782   deflation_UU    ~> deflation_bottom
   783   finite_deflation_UU ~> finite_deflation_bottom
   784 
   785 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   786 
   787   sq_ord_less_eq_trans ~> below_eq_trans
   788   sq_ord_eq_less_trans ~> eq_below_trans
   789   refl_less            ~> below_refl
   790   trans_less           ~> below_trans
   791   antisym_less         ~> below_antisym
   792   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   793   box_less             ~> box_below
   794   rev_trans_less       ~> rev_below_trans
   795   not_less2not_eq      ~> not_below2not_eq
   796   less_UU_iff          ~> below_UU_iff
   797   flat_less_iff        ~> flat_below_iff
   798   adm_less             ~> adm_below
   799   adm_not_less         ~> adm_not_below
   800   adm_compact_not_less ~> adm_compact_not_below
   801   less_fun_def         ~> below_fun_def
   802   expand_fun_less      ~> fun_below_iff
   803   less_fun_ext         ~> fun_belowI
   804   less_discr_def       ~> below_discr_def
   805   discr_less_eq        ~> discr_below_eq
   806   less_unit_def        ~> below_unit_def
   807   less_cprod_def       ~> below_prod_def
   808   prod_lessI           ~> prod_belowI
   809   Pair_less_iff        ~> Pair_below_iff
   810   fst_less_iff         ~> fst_below_iff
   811   snd_less_iff         ~> snd_below_iff
   812   expand_cfun_less     ~> cfun_below_iff
   813   less_cfun_ext        ~> cfun_belowI
   814   injection_less       ~> injection_below
   815   less_up_def          ~> below_up_def
   816   not_Iup_less         ~> not_Iup_below
   817   Iup_less             ~> Iup_below
   818   up_less              ~> up_below
   819   Def_inject_less_eq   ~> Def_below_Def
   820   Def_less_is_eq       ~> Def_below_iff
   821   spair_less_iff       ~> spair_below_iff
   822   less_sprod           ~> below_sprod
   823   spair_less           ~> spair_below
   824   sfst_less_iff        ~> sfst_below_iff
   825   ssnd_less_iff        ~> ssnd_below_iff
   826   fix_least_less       ~> fix_least_below
   827   dist_less_one        ~> dist_below_one
   828   less_ONE             ~> below_ONE
   829   ONE_less_iff         ~> ONE_below_iff
   830   less_sinlD           ~> below_sinlD
   831   less_sinrD           ~> below_sinrD
   832 
   833 
   834 *** FOL and ZF ***
   835 
   836 * All constant names are now qualified internally and use proper
   837 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   838 
   839 
   840 *** ML ***
   841 
   842 * Antiquotation @{assert} inlines a function bool -> unit that raises
   843 Fail if the argument is false.  Due to inlining the source position of
   844 failed assertions is included in the error output.
   845 
   846 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   847 text is in practice always evaluated with a stable theory checkpoint.
   848 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   849 
   850 * Antiquotation @{theory A} refers to theory A from the ancestry of
   851 the current context, not any accidental theory loader state as before.
   852 Potential INCOMPATIBILITY, subtle change in semantics.
   853 
   854 * Syntax.pretty_priority (default 0) configures the required priority
   855 of pretty-printed output and thus affects insertion of parentheses.
   856 
   857 * Syntax.default_root (default "any") configures the inner syntax
   858 category (nonterminal symbol) for parsing of terms.
   859 
   860 * Former exception Library.UnequalLengths now coincides with
   861 ListPair.UnequalLengths.
   862 
   863 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   864 main functionality is provided by structure Simplifier.
   865 
   866 * Renamed raw "explode" function to "raw_explode" to emphasize its
   867 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   868 almost all situations.
   869 
   870 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   871 See implementation manual for further details on exceptions in
   872 Isabelle/ML.
   873 
   874 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   875 meaning.
   876 
   877 * Renamed structure PureThy to Pure_Thy and moved most of its
   878 operations to structure Global_Theory, to emphasize that this is
   879 rarely-used global-only stuff.
   880 
   881 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   882 instead (or tracing for high-volume output).
   883 
   884 * Configuration option show_question_marks only affects regular pretty
   885 printing of types and terms, not raw Term.string_of_vname.
   886 
   887 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   888 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   889 @{thms} for most purposes.
   890 
   891 * ML structure Unsynchronized is never opened, not even in Isar
   892 interaction mode as before.  Old Unsynchronized.set etc. have been
   893 discontinued -- use plain := instead.  This should be *rare* anyway,
   894 since modern tools always work via official context data, notably
   895 configuration options.
   896 
   897 * Parallel and asynchronous execution requires special care concerning
   898 interrupts.  Structure Exn provides some convenience functions that
   899 avoid working directly with raw Interrupt.  User code must not absorb
   900 interrupts -- intermediate handling (for cleanup etc.) needs to be
   901 followed by re-raising of the original exception.  Another common
   902 source of mistakes are "handle _" patterns, which make the meaning of
   903 the program subject to physical effects of the environment.
   904 
   905 
   906 
   907 New in Isabelle2009-2 (June 2010)
   908 ---------------------------------
   909 
   910 *** General ***
   911 
   912 * Authentic syntax for *all* logical entities (type classes, type
   913 constructors, term constants): provides simple and robust
   914 correspondence between formal entities and concrete syntax.  Within
   915 the parse tree / AST representations, "constants" are decorated by
   916 their category (class, type, const) and spelled out explicitly with
   917 their full internal name.
   918 
   919 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   920 and translations (translation rules and translation functions in ML).
   921 Some hints on upgrading:
   922 
   923   - Many existing uses of 'syntax' and 'translations' can be replaced
   924     by more modern 'type_notation', 'notation' and 'abbreviation',
   925     which are independent of this issue.
   926 
   927   - 'translations' require markup within the AST; the term syntax
   928     provides the following special forms:
   929 
   930       CONST c   -- produces syntax version of constant c from context
   931       XCONST c  -- literally c, checked as constant from context
   932       c         -- literally c, if declared by 'syntax'
   933 
   934     Plain identifiers are treated as AST variables -- occasionally the
   935     system indicates accidental variables via the error "rhs contains
   936     extra variables".
   937 
   938     Type classes and type constructors are marked according to their
   939     concrete syntax.  Some old translations rules need to be written
   940     for the "type" category, using type constructor application
   941     instead of pseudo-term application of the default category
   942     "logic".
   943 
   944   - 'parse_translation' etc. in ML may use the following
   945     antiquotations:
   946 
   947       @{class_syntax c}   -- type class c within parse tree / AST
   948       @{term_syntax c}    -- type constructor c within parse tree / AST
   949       @{const_syntax c}   -- ML version of "CONST c" above
   950       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   951 
   952   - Literal types within 'typed_print_translations', i.e. those *not*
   953     represented as pseudo-terms are represented verbatim.  Use @{class
   954     c} or @{type_name c} here instead of the above syntax
   955     antiquotations.
   956 
   957 Note that old non-authentic syntax was based on unqualified base
   958 names, so all of the above "constant" names would coincide.  Recall
   959 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   960 diagnose syntax problems.
   961 
   962 * Type constructors admit general mixfix syntax, not just infix.
   963 
   964 * Concrete syntax may be attached to local entities without a proof
   965 body, too.  This works via regular mixfix annotations for 'fix',
   966 'def', 'obtain' etc. or via the explicit 'write' command, which is
   967 similar to the 'notation' command in theory specifications.
   968 
   969 * Discontinued unnamed infix syntax (legacy feature for many years) --
   970 need to specify constant name and syntax separately.  Internal ML
   971 datatype constructors have been renamed from InfixName to Infix etc.
   972 Minor INCOMPATIBILITY.
   973 
   974 * Schematic theorem statements need to be explicitly markup as such,
   975 via commands 'schematic_lemma', 'schematic_theorem',
   976 'schematic_corollary'.  Thus the relevance of the proof is made
   977 syntactically clear, which impacts performance in a parallel or
   978 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   979 
   980 * Use of cumulative prems via "!" in some proof methods has been
   981 discontinued (old legacy feature).
   982 
   983 * References 'trace_simp' and 'debug_simp' have been replaced by
   984 configuration options stored in the context. Enabling tracing (the
   985 case of debugging is similar) in proofs works via
   986 
   987   using [[trace_simp = true]]
   988 
   989 Tracing is then active for all invocations of the simplifier in
   990 subsequent goal refinement steps. Tracing may also still be enabled or
   991 disabled via the ProofGeneral settings menu.
   992 
   993 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   994 'hide_fact' replace the former 'hide' KIND command.  Minor
   995 INCOMPATIBILITY.
   996 
   997 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   998 more efficient than combinations with -q1 or -q2.
   999 
  1000 
  1001 *** Pure ***
  1002 
  1003 * Proofterms record type-class reasoning explicitly, using the
  1004 "unconstrain" operation internally.  This eliminates all sort
  1005 constraints from a theorem and proof, introducing explicit
  1006 OFCLASS-premises.  On the proof term level, this operation is
  1007 automatically applied at theorem boundaries, such that closed proofs
  1008 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1009 inspect proof terms.
  1010 
  1011 * Local theory specifications may depend on extra type variables that
  1012 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1013 are added internally.  For example:
  1014 
  1015   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1016 
  1017 * Predicates of locales introduced by classes carry a mandatory
  1018 "class" prefix.  INCOMPATIBILITY.
  1019 
  1020 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1021 
  1022 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1023 'class' instead.
  1024 
  1025 * Command 'code_reflect' allows to incorporate generated ML code into
  1026 runtime environment; replaces immature code_datatype antiquotation.
  1027 INCOMPATIBILITY.
  1028 
  1029 * Code generator: simple concept for abstract datatypes obeying
  1030 invariants.
  1031 
  1032 * Code generator: details of internal data cache have no impact on the
  1033 user space functionality any longer.
  1034 
  1035 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1036 subgoals.  This is more appropriate for interpretations with 'where'.
  1037 INCOMPATIBILITY.
  1038 
  1039 * Command 'example_proof' opens an empty proof body.  This allows to
  1040 experiment with Isar, without producing any persistent result.
  1041 
  1042 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1043 within a local theory context, with explicit checking of the
  1044 constructors involved (in contrast to the raw 'syntax' versions).
  1045 
  1046 * Commands 'types' and 'typedecl' now work within a local theory
  1047 context -- without introducing dependencies on parameters or
  1048 assumptions, which is not possible in Isabelle/Pure.
  1049 
  1050 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1051 within a local theory context.  Minor INCOMPATIBILITY.
  1052 
  1053 
  1054 *** HOL ***
  1055 
  1056 * Command 'typedef' now works within a local theory context -- without
  1057 introducing dependencies on parameters or assumptions, which is not
  1058 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1059 contain multiple interpretations of local typedefs (with different
  1060 non-emptiness proofs), even in a global theory context.
  1061 
  1062 * New package for quotient types.  Commands 'quotient_type' and
  1063 'quotient_definition' may be used for defining types and constants by
  1064 quotient constructions.  An example is the type of integers created by
  1065 quotienting pairs of natural numbers:
  1066 
  1067   fun
  1068     intrel :: "(nat * nat) => (nat * nat) => bool"
  1069   where
  1070     "intrel (x, y) (u, v) = (x + v = u + y)"
  1071 
  1072   quotient_type int = "nat * nat" / intrel
  1073     by (auto simp add: equivp_def expand_fun_eq)
  1074 
  1075   quotient_definition
  1076     "0::int" is "(0::nat, 0::nat)"
  1077 
  1078 The method "lifting" can be used to lift of theorems from the
  1079 underlying "raw" type to the quotient type.  The example
  1080 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1081 construction and provides a reasoning infrastructure for finite sets.
  1082 
  1083 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1084 clash with new theory Quotient in Main HOL.
  1085 
  1086 * Moved the SMT binding into the main HOL session, eliminating
  1087 separate HOL-SMT session.
  1088 
  1089 * List membership infix mem operation is only an input abbreviation.
  1090 INCOMPATIBILITY.
  1091 
  1092 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1093 for future developements; former Library/Word.thy is still present in
  1094 the AFP entry RSAPPS.
  1095 
  1096 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1097 longer shadowed.  INCOMPATIBILITY.
  1098 
  1099 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1100 INCOMPATIBILITY.
  1101 
  1102 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1103 INCOMPATIBILITY.
  1104 
  1105 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1106 instead.  INCOMPATIBILITY.
  1107 
  1108 * Dropped several real-specific versions of lemmas about floor and
  1109 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1110 instead.  INCOMPATIBILITY.
  1111 
  1112   floor_number_of_eq         ~> floor_number_of
  1113   le_floor_eq_number_of      ~> number_of_le_floor
  1114   le_floor_eq_zero           ~> zero_le_floor
  1115   le_floor_eq_one            ~> one_le_floor
  1116   floor_less_eq_number_of    ~> floor_less_number_of
  1117   floor_less_eq_zero         ~> floor_less_zero
  1118   floor_less_eq_one          ~> floor_less_one
  1119   less_floor_eq_number_of    ~> number_of_less_floor
  1120   less_floor_eq_zero         ~> zero_less_floor
  1121   less_floor_eq_one          ~> one_less_floor
  1122   floor_le_eq_number_of      ~> floor_le_number_of
  1123   floor_le_eq_zero           ~> floor_le_zero
  1124   floor_le_eq_one            ~> floor_le_one
  1125   floor_subtract_number_of   ~> floor_diff_number_of
  1126   floor_subtract_one         ~> floor_diff_one
  1127   ceiling_number_of_eq       ~> ceiling_number_of
  1128   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1129   ceiling_le_zero_eq         ~> ceiling_le_zero
  1130   ceiling_le_eq_one          ~> ceiling_le_one
  1131   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1132   less_ceiling_eq_zero       ~> zero_less_ceiling
  1133   less_ceiling_eq_one        ~> one_less_ceiling
  1134   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1135   ceiling_less_eq_zero       ~> ceiling_less_zero
  1136   ceiling_less_eq_one        ~> ceiling_less_one
  1137   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1138   le_ceiling_eq_zero         ~> zero_le_ceiling
  1139   le_ceiling_eq_one          ~> one_le_ceiling
  1140   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1141   ceiling_subtract_one       ~> ceiling_diff_one
  1142 
  1143 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1144 application of the various fold combinators on finite sets.
  1145 
  1146 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1147 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1148 implementation.  INCOMPATIBILTY.
  1149 
  1150 * Theory Library/Coinductive_List has been removed -- superseded by
  1151 AFP/thys/Coinductive.
  1152 
  1153 * Theory PReal, including the type "preal" and related operations, has
  1154 been removed.  INCOMPATIBILITY.
  1155 
  1156 * Real: new development using Cauchy Sequences.
  1157 
  1158 * Split off theory "Big_Operators" containing setsum, setprod,
  1159 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1160 
  1161 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1162 "Int" etc.  INCOMPATIBILITY.
  1163 
  1164 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1165 
  1166 * New set of rules "ac_simps" provides combined assoc / commute
  1167 rewrites for all interpretations of the appropriate generic locales.
  1168 
  1169 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1170 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1171 appropriate and more consistent names suitable for name prefixes
  1172 within the HOL theories.  INCOMPATIBILITY.
  1173 
  1174 * Some generic constants have been put to appropriate theories:
  1175   - less_eq, less: Orderings
  1176   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1177   - inverse, divide: Rings
  1178 INCOMPATIBILITY.
  1179 
  1180 * More consistent naming of type classes involving orderings (and
  1181 lattices):
  1182 
  1183     lower_semilattice                   ~> semilattice_inf
  1184     upper_semilattice                   ~> semilattice_sup
  1185 
  1186     dense_linear_order                  ~> dense_linorder
  1187 
  1188     pordered_ab_group_add               ~> ordered_ab_group_add
  1189     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1190     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1191     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1192     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1193     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1194     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1195     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1196     pordered_comm_ring                  ~> ordered_comm_ring
  1197     pordered_comm_semiring              ~> ordered_comm_semiring
  1198     pordered_ring                       ~> ordered_ring
  1199     pordered_ring_abs                   ~> ordered_ring_abs
  1200     pordered_semiring                   ~> ordered_semiring
  1201 
  1202     ordered_ab_group_add                ~> linordered_ab_group_add
  1203     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1204     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1205     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1206     ordered_field                       ~> linordered_field
  1207     ordered_field_no_lb                 ~> linordered_field_no_lb
  1208     ordered_field_no_ub                 ~> linordered_field_no_ub
  1209     ordered_field_dense_linear_order    ~> dense_linordered_field
  1210     ordered_idom                        ~> linordered_idom
  1211     ordered_ring                        ~> linordered_ring
  1212     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1213     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1214     ordered_ring_strict                 ~> linordered_ring_strict
  1215     ordered_semidom                     ~> linordered_semidom
  1216     ordered_semiring                    ~> linordered_semiring
  1217     ordered_semiring_1                  ~> linordered_semiring_1
  1218     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1219     ordered_semiring_strict             ~> linordered_semiring_strict
  1220 
  1221   The following slightly odd type classes have been moved to a
  1222   separate theory Library/Lattice_Algebras:
  1223 
  1224     lordered_ab_group_add               ~> lattice_ab_group_add
  1225     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1226     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1227     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1228     lordered_ring                       ~> lattice_ring
  1229 
  1230 INCOMPATIBILITY.
  1231 
  1232 * Refined field classes:
  1233   - classes division_ring_inverse_zero, field_inverse_zero,
  1234     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1235     subsumes former division_by_zero class;
  1236   - numerous lemmas have been ported from field to division_ring.
  1237 INCOMPATIBILITY.
  1238 
  1239 * Refined algebra theorem collections:
  1240   - dropped theorem group group_simps, use algebra_simps instead;
  1241   - dropped theorem group ring_simps, use field_simps instead;
  1242   - proper theorem collection field_simps subsumes former theorem
  1243     groups field_eq_simps and field_simps;
  1244   - dropped lemma eq_minus_self_iff which is a duplicate for
  1245     equal_neg_zero.
  1246 INCOMPATIBILITY.
  1247 
  1248 * Theory Finite_Set and List: some lemmas have been generalized from
  1249 sets to lattices:
  1250 
  1251   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1252   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1253   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1254   union_Union_fold_union        ~> sup_Sup_fold_sup
  1255   Inter_fold_inter              ~> Inf_fold_inf
  1256   Union_fold_union              ~> Sup_fold_sup
  1257   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1258   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1259   INTER_fold_inter              ~> INFI_fold_inf
  1260   UNION_fold_union              ~> SUPR_fold_sup
  1261 
  1262 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1263 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1264 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1265 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1266 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1267 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1268 
  1269 * Reorganized theory Multiset: swapped notation of pointwise and
  1270 multiset order:
  1271 
  1272   - pointwise ordering is instance of class order with standard syntax
  1273     <= and <;
  1274   - multiset ordering has syntax <=# and <#; partial order properties
  1275     are provided by means of interpretation with prefix
  1276     multiset_order;
  1277   - less duplication, less historical organization of sections,
  1278     conversion from associations lists to multisets, rudimentary code
  1279     generation;
  1280   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1281     if needed.
  1282 
  1283 Renamed:
  1284 
  1285   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1286   multi_count_ext  ~>  multiset_ext
  1287   diff_union_inverse2  ~>  diff_union_cancelR
  1288 
  1289 INCOMPATIBILITY.
  1290 
  1291 * Theory Permutation: replaced local "remove" by List.remove1.
  1292 
  1293 * Code generation: ML and OCaml code is decorated with signatures.
  1294 
  1295 * Theory List: added transpose.
  1296 
  1297 * Library/Nat_Bijection.thy is a collection of bijective functions
  1298 between nat and other types, which supersedes the older libraries
  1299 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1300 
  1301   Constants:
  1302   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1303   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1304   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1305   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1306   Countable.pair_encode           ~> prod_encode
  1307   NatIso.prod2nat                 ~> prod_encode
  1308   NatIso.nat2prod                 ~> prod_decode
  1309   NatIso.sum2nat                  ~> sum_encode
  1310   NatIso.nat2sum                  ~> sum_decode
  1311   NatIso.list2nat                 ~> list_encode
  1312   NatIso.nat2list                 ~> list_decode
  1313   NatIso.set2nat                  ~> set_encode
  1314   NatIso.nat2set                  ~> set_decode
  1315 
  1316   Lemmas:
  1317   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1318   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1319   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1320   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1321   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1322   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1323   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1324   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1325   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1326   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1327   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1328   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1329   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1330 
  1331 * Sledgehammer:
  1332   - Renamed ATP commands:
  1333     atp_info     ~> sledgehammer running_atps
  1334     atp_kill     ~> sledgehammer kill_atps
  1335     atp_messages ~> sledgehammer messages
  1336     atp_minimize ~> sledgehammer minimize
  1337     print_atps   ~> sledgehammer available_atps
  1338     INCOMPATIBILITY.
  1339   - Added user's manual ("isabelle doc sledgehammer").
  1340   - Added option syntax and "sledgehammer_params" to customize
  1341     Sledgehammer's behavior.  See the manual for details.
  1342   - Modified the Isar proof reconstruction code so that it produces
  1343     direct proofs rather than proofs by contradiction.  (This feature
  1344     is still experimental.)
  1345   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1346     full-typed mode.
  1347   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1348 
  1349 * Nitpick:
  1350   - Added and implemented "binary_ints" and "bits" options.
  1351   - Added "std" option and implemented support for nonstandard models.
  1352   - Added and implemented "finitize" option to improve the precision
  1353     of infinite datatypes based on a monotonicity analysis.
  1354   - Added support for quotient types.
  1355   - Added support for "specification" and "ax_specification"
  1356     constructs.
  1357   - Added support for local definitions (for "function" and
  1358     "termination" proofs).
  1359   - Added support for term postprocessors.
  1360   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1361   - Improved efficiency of "destroy_constrs" optimization.
  1362   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1363     record getters.
  1364   - Fixed soundness bug related to higher-order constructors.
  1365   - Fixed soundness bug when "full_descrs" is enabled.
  1366   - Improved precision of set constructs.
  1367   - Added "atoms" option.
  1368   - Added cache to speed up repeated Kodkod invocations on the same
  1369     problems.
  1370   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1371     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1372     "SAT4J_Light".  INCOMPATIBILITY.
  1373   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1374     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1375   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1376 
  1377 * Method "induct" now takes instantiations of the form t, where t is not
  1378   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1379   If this is not intended, t has to be enclosed in parentheses.
  1380   By default, the equalities generated by definitional instantiations
  1381   are pre-simplified, which may cause parameters of inductive cases
  1382   to disappear, or may even delete some of the inductive cases.
  1383   Use "induct (no_simp)" instead of "induct" to restore the old
  1384   behaviour. The (no_simp) option is also understood by the "cases"
  1385   and "nominal_induct" methods, which now perform pre-simplification, too.
  1386   INCOMPATIBILITY.
  1387 
  1388 
  1389 *** HOLCF ***
  1390 
  1391 * Variable names in lemmas generated by the domain package have
  1392 changed; the naming scheme is now consistent with the HOL datatype
  1393 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1394 
  1395 * The domain package no longer defines the function "foo_copy" for
  1396 recursive domain "foo".  The reach lemma is now stated directly in
  1397 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1398 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1399 
  1400 * Most definedness lemmas generated by the domain package (previously
  1401 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1402 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1403 Proofs that used definedness lemmas as intro rules may break,
  1404 potential INCOMPATIBILITY.
  1405 
  1406 * Induction and casedist rules generated by the domain package now
  1407 declare proper case_names (one called "bottom", and one named for each
  1408 constructor).  INCOMPATIBILITY.
  1409 
  1410 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1411 rules are generated for each domain, INCOMPATIBILITY.
  1412 
  1413   foo_bar.reach       ~> foo.reach  bar.reach
  1414   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1415 
  1416 * Some lemmas generated by the domain package have been renamed for
  1417 consistency with the datatype package, INCOMPATIBILITY.
  1418 
  1419   foo.ind        ~> foo.induct
  1420   foo.finite_ind ~> foo.finite_induct
  1421   foo.coind      ~> foo.coinduct
  1422   foo.casedist   ~> foo.exhaust
  1423   foo.exhaust    ~> foo.nchotomy
  1424 
  1425 * For consistency with other definition packages, the fixrec package
  1426 now generates qualified theorem names, INCOMPATIBILITY.
  1427 
  1428   foo_simps  ~> foo.simps
  1429   foo_unfold ~> foo.unfold
  1430   foo_induct ~> foo.induct
  1431 
  1432 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1433 method and internal fixrec proofs now use the default simpset instead.
  1434 INCOMPATIBILITY.
  1435 
  1436 * The "contlub" predicate has been removed.  Proof scripts should use
  1437 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1438 
  1439 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1440 
  1441 * The constants cpair, cfst, and csnd have been removed in favor of
  1442 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1443 
  1444 
  1445 *** ML ***
  1446 
  1447 * Antiquotations for basic formal entities:
  1448 
  1449     @{class NAME}         -- type class
  1450     @{class_syntax NAME}  -- syntax representation of the above
  1451 
  1452     @{type_name NAME}     -- logical type
  1453     @{type_abbrev NAME}   -- type abbreviation
  1454     @{nonterminal NAME}   -- type of concrete syntactic category
  1455     @{type_syntax NAME}   -- syntax representation of any of the above
  1456 
  1457     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1458     @{const_abbrev NAME}  -- abbreviated constant
  1459     @{const_syntax NAME}  -- syntax representation of any of the above
  1460 
  1461 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1462 syntax constant (cf. 'syntax' command).
  1463 
  1464 * Antiquotation @{make_string} inlines a function to print arbitrary
  1465 values similar to the ML toplevel.  The result is compiler dependent
  1466 and may fall back on "?" in certain situations.
  1467 
  1468 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1469 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1470 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1471 not work with the asynchronous Isar document model.
  1472 
  1473 * Configuration options now admit dynamic default values, depending on
  1474 the context or even global references.
  1475 
  1476 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1477 uses an efficient external library if available (for Poly/ML).
  1478 
  1479 * Renamed some important ML structures, while keeping the old names
  1480 for some time as aliases within the structure Legacy:
  1481 
  1482   OuterKeyword  ~>  Keyword
  1483   OuterLex      ~>  Token
  1484   OuterParse    ~>  Parse
  1485   OuterSyntax   ~>  Outer_Syntax
  1486   PrintMode     ~>  Print_Mode
  1487   SpecParse     ~>  Parse_Spec
  1488   ThyInfo       ~>  Thy_Info
  1489   ThyLoad       ~>  Thy_Load
  1490   ThyOutput     ~>  Thy_Output
  1491   TypeInfer     ~>  Type_Infer
  1492 
  1493 Note that "open Legacy" simplifies porting of sources, but forgetting
  1494 to remove it again will complicate porting again in the future.
  1495 
  1496 * Most operations that refer to a global context are named
  1497 accordingly, e.g. Simplifier.global_context or
  1498 ProofContext.init_global.  There are some situations where a global
  1499 context actually works, but under normal circumstances one needs to
  1500 pass the proper local context through the code!
  1501 
  1502 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1503 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1504 Pretty.pp argument to merge, which is absent in the standard
  1505 Theory_Data version.
  1506 
  1507 * Sorts.certify_sort and derived "cert" operations for types and terms
  1508 no longer minimize sorts.  Thus certification at the boundary of the
  1509 inference kernel becomes invariant under addition of class relations,
  1510 which is an important monotonicity principle.  Sorts are now minimized
  1511 in the syntax layer only, at the boundary between the end-user and the
  1512 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1513 explicitly in rare situations.
  1514 
  1515 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1516 emphasize that this is in no way a standard operation.
  1517 INCOMPATIBILITY.
  1518 
  1519 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1520 usual for resolution.  Rare INCOMPATIBILITY.
  1521 
  1522 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1523 to emphasize that these only work in a global situation (which is
  1524 quite rare).
  1525 
  1526 * Curried take and drop in library.ML; negative length is interpreted
  1527 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1528 
  1529 * Proof terms: type substitutions on proof constants now use canonical
  1530 order of type variables.  INCOMPATIBILITY for tools working with proof
  1531 terms.
  1532 
  1533 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1534 may no longer carry premises.  User-level specifications are
  1535 transformed accordingly by Thm.add_axiom/add_def.
  1536 
  1537 
  1538 *** System ***
  1539 
  1540 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1541 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1542 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1543 
  1544 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1545 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1546 respectively.
  1547 
  1548 * Old lib/scripts/polyml-platform is superseded by the
  1549 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1550 variant, even on a 64 bit machine.  The following example setting
  1551 prefers 64 bit if available:
  1552 
  1553   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1554 
  1555 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1556 Isabelle/Scala layer for advanced prover interaction and integration.
  1557 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1558 component.
  1559 
  1560 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1561 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1562 similar to the default assignment of the document preparation system
  1563 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1564 provides some operations for direct access to the font without asking
  1565 the user for manual installation.
  1566 
  1567 
  1568 
  1569 New in Isabelle2009-1 (December 2009)
  1570 -------------------------------------
  1571 
  1572 *** General ***
  1573 
  1574 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1575 one backslash should be used, even in ML sources.
  1576 
  1577 
  1578 *** Pure ***
  1579 
  1580 * Locale interpretation propagates mixins along the locale hierarchy.
  1581 The currently only available mixins are the equations used to map
  1582 local definitions to terms of the target domain of an interpretation.
  1583 
  1584 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1585 loc" to print all interpretations of locale "loc" in the theory.
  1586 Interpretations in proofs are not shown.
  1587 
  1588 * Thoroughly revised locales tutorial.  New section on conditional
  1589 interpretation.
  1590 
  1591 * On instantiation of classes, remaining undefined class parameters
  1592 are formally declared.  INCOMPATIBILITY.
  1593 
  1594 
  1595 *** Document preparation ***
  1596 
  1597 * New generalized style concept for printing terms: @{foo (style) ...}
  1598 instead of @{foo_style style ...}  (old form is still retained for
  1599 backward compatibility).  Styles can be also applied for
  1600 antiquotations prop, term_type and typeof.
  1601 
  1602 
  1603 *** HOL ***
  1604 
  1605 * New proof method "smt" for a combination of first-order logic with
  1606 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1607 fixed-size bitvectors; there is also basic support for higher-order
  1608 features (esp. lambda abstractions).  It is an incomplete decision
  1609 procedure based on external SMT solvers using the oracle mechanism;
  1610 for the SMT solver Z3, this method is proof-producing.  Certificates
  1611 are provided to avoid calling the external solvers solely for
  1612 re-checking proofs.  Due to a remote SMT service there is no need for
  1613 installing SMT solvers locally.  See src/HOL/SMT.
  1614 
  1615 * New commands to load and prove verification conditions generated by
  1616 the Boogie program verifier or derived systems (e.g. the Verifying C
  1617 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1618 
  1619 * New counterexample generator tool 'nitpick' based on the Kodkod
  1620 relational model finder.  See src/HOL/Tools/Nitpick and
  1621 src/HOL/Nitpick_Examples.
  1622 
  1623 * New commands 'code_pred' and 'values' to invoke the predicate
  1624 compiler and to enumerate values of inductive predicates.
  1625 
  1626 * A tabled implementation of the reflexive transitive closure.
  1627 
  1628 * New implementation of quickcheck uses generic code generator;
  1629 default generators are provided for all suitable HOL types, records
  1630 and datatypes.  Old quickcheck can be re-activated importing theory
  1631 Library/SML_Quickcheck.
  1632 
  1633 * New testing tool Mirabelle for automated proof tools.  Applies
  1634 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1635 every proof step in a theory.  To be used in batch mode via the
  1636 "mirabelle" utility.
  1637 
  1638 * New proof method "sos" (sum of squares) for nonlinear real
  1639 arithmetic (originally due to John Harison). It requires theory
  1640 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1641 works well in practice on quantifier-free real arithmetic with +, -,
  1642 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1643 inequalities between polynomials.  It makes use of external
  1644 semidefinite programming solvers.  Method "sos" generates a
  1645 certificate that can be pasted into the proof thus avoiding the need
  1646 to call an external tool every time the proof is checked.  See
  1647 src/HOL/Library/Sum_Of_Squares.
  1648 
  1649 * New method "linarith" invokes existing linear arithmetic decision
  1650 procedure only.
  1651 
  1652 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1653 
  1654 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1655 Causes full type information to be output to the ATPs.  This slows
  1656 ATPs down considerably but eliminates a source of unsound "proofs"
  1657 that fail later.
  1658 
  1659 * New method "metisFT": A version of metis that uses full type
  1660 information in order to avoid failures of proof reconstruction.
  1661 
  1662 * New evaluator "approximate" approximates an real valued term using
  1663 the same method as the approximation method.
  1664 
  1665 * Method "approximate" now supports arithmetic expressions as
  1666 boundaries of intervals and implements interval splitting and Taylor
  1667 series expansion.
  1668 
  1669 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1670 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1671 
  1672 * New theory SupInf of the supremum and infimum operators for sets of
  1673 reals.
  1674 
  1675 * New theory Probability, which contains a development of measure
  1676 theory, eventually leading to Lebesgue integration and probability.
  1677 
  1678 * Extended Multivariate Analysis to include derivation and Brouwer's
  1679 fixpoint theorem.
  1680 
  1681 * Reorganization of number theory, INCOMPATIBILITY:
  1682   - new number theory development for nat and int, in theories Divides
  1683     and GCD as well as in new session Number_Theory
  1684   - some constants and facts now suffixed with _nat and _int
  1685     accordingly
  1686   - former session NumberTheory now named Old_Number_Theory, including
  1687     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1688   - moved theory Pocklington from src/HOL/Library to
  1689     src/HOL/Old_Number_Theory
  1690 
  1691 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1692 lcm of finite and infinite sets. It is shown that they form a complete
  1693 lattice.
  1694 
  1695 * Class semiring_div requires superclass no_zero_divisors and proof of
  1696 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1697 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1698 generalized to class semiring_div, subsuming former theorems
  1699 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1700 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1701 INCOMPATIBILITY.
  1702 
  1703 * Refinements to lattice classes and sets:
  1704   - less default intro/elim rules in locale variant, more default
  1705     intro/elim rules in class variant: more uniformity
  1706   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1707     le_inf_iff
  1708   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1709     sup_aci)
  1710   - renamed ACI to inf_sup_aci
  1711   - new class "boolean_algebra"
  1712   - class "complete_lattice" moved to separate theory
  1713     "Complete_Lattice"; corresponding constants (and abbreviations)
  1714     renamed and with authentic syntax:
  1715     Set.Inf ~>    Complete_Lattice.Inf
  1716     Set.Sup ~>    Complete_Lattice.Sup
  1717     Set.INFI ~>   Complete_Lattice.INFI
  1718     Set.SUPR ~>   Complete_Lattice.SUPR
  1719     Set.Inter ~>  Complete_Lattice.Inter
  1720     Set.Union ~>  Complete_Lattice.Union
  1721     Set.INTER ~>  Complete_Lattice.INTER
  1722     Set.UNION ~>  Complete_Lattice.UNION
  1723   - authentic syntax for
  1724     Set.Pow
  1725     Set.image
  1726   - mere abbreviations:
  1727     Set.empty               (for bot)
  1728     Set.UNIV                (for top)
  1729     Set.inter               (for inf, formerly Set.Int)
  1730     Set.union               (for sup, formerly Set.Un)
  1731     Complete_Lattice.Inter  (for Inf)
  1732     Complete_Lattice.Union  (for Sup)
  1733     Complete_Lattice.INTER  (for INFI)
  1734     Complete_Lattice.UNION  (for SUPR)
  1735   - object-logic definitions as far as appropriate
  1736 
  1737 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1738 Un_subset_iff are explicitly deleted as default simp rules; then also
  1739 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1740 deleted to achieve the desired effect.
  1741 
  1742 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1743 rules by default any longer; the same applies to min_max.inf_absorb1
  1744 etc.  INCOMPATIBILITY.
  1745 
  1746 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1747 pred_set_conv by default.  INCOMPATIBILITY.
  1748 
  1749 * Power operations on relations and functions are now one dedicated
  1750 constant "compow" with infix syntax "^^".  Power operation on
  1751 multiplicative monoids retains syntax "^" and is now defined generic
  1752 in class power.  INCOMPATIBILITY.
  1753 
  1754 * Relation composition "R O S" now has a more standard argument order:
  1755 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1756 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1757 break, since the O_assoc rule was not rewritten like this.  Fix using
  1758 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1759 
  1760 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1761 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1762 INCOMPATIBILITY.
  1763 
  1764 * Most rules produced by inductive and datatype package have mandatory
  1765 prefixes.  INCOMPATIBILITY.
  1766 
  1767 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1768 the attribute of the same name.  Each of the theorems in the list
  1769 DERIV_intros assumes composition with an additional function and
  1770 matches a variable to the derivative, which has to be solved by the
  1771 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1772 of most elementary terms.  Former Maclauren.DERIV_tac and
  1773 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1774 INCOMPATIBILITY.
  1775 
  1776 * Code generator attributes follow the usual underscore convention:
  1777     code_unfold     replaces    code unfold
  1778     code_post       replaces    code post
  1779     etc.
  1780   INCOMPATIBILITY.
  1781 
  1782 * Renamed methods:
  1783     sizechange -> size_change
  1784     induct_scheme -> induction_schema
  1785   INCOMPATIBILITY.
  1786 
  1787 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1788 INCOMPATIBILITY, use "undefined" directly.
  1789 
  1790 * Renamed theorems:
  1791     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1792     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1793     Suc_plus1 -> Suc_eq_plus1
  1794     *anti_sym -> *antisym*
  1795     vector_less_eq_def -> vector_le_def
  1796   INCOMPATIBILITY.
  1797 
  1798 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1799 INCOMPATIBILITY.
  1800 
  1801 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1802 INCOMPATIBILITY.
  1803 
  1804 
  1805 *** HOLCF ***
  1806 
  1807 * Theory Representable defines a class "rep" of domains that are
  1808 representable (via an ep-pair) in the universal domain type "udom".
  1809 Instances are provided for all type constructors defined in HOLCF.
  1810 
  1811 * The 'new_domain' command is a purely definitional version of the
  1812 domain package, for representable domains.  Syntax is identical to the
  1813 old domain package.  The 'new_domain' package also supports indirect
  1814 recursion using previously-defined type constructors.  See
  1815 src/HOLCF/ex/New_Domain.thy for examples.
  1816 
  1817 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1818 on the left-hand side of an equation, and then performs
  1819 simplification.  Rewriting is done using rules declared with the
  1820 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1821 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1822 
  1823 * The pattern-match compiler in 'fixrec' can now handle constructors
  1824 with HOL function types.  Pattern-match combinators for the Pair
  1825 constructor are pre-configured.
  1826 
  1827 * The 'fixrec' package now produces better fixed-point induction rules
  1828 for mutually-recursive definitions:  Induction rules have conclusions
  1829 of the form "P foo bar" instead of "P <foo, bar>".
  1830 
  1831 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1832 been renamed to "below".  The name "below" now replaces "less" in many
  1833 theorem names.  (Legacy theorem names using "less" are still supported
  1834 as well.)
  1835 
  1836 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1837 patterns can be used to generate strictness rules, or to make
  1838 functions more strict (much like the bang-patterns supported by the
  1839 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1840 examples.
  1841 
  1842 
  1843 *** ML ***
  1844 
  1845 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1846 errors and run-time exceptions, including detailed source positions.
  1847 
  1848 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1849 identified entries, with some additional information such as source
  1850 position, logical grouping etc.
  1851 
  1852 * Theory and context data is now introduced by the simplified and
  1853 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1854 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1855 copy operation) is still available for some time.
  1856 
  1857 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1858 provides a high-level programming interface to synchronized state
  1859 variables with atomic update.  This works via pure function
  1860 application within a critical section -- its runtime should be as
  1861 short as possible; beware of deadlocks if critical code is nested,
  1862 either directly or indirectly via other synchronized variables!
  1863 
  1864 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1865 wraps raw ML references, explicitly indicating their non-thread-safe
  1866 behaviour.  The Isar toplevel keeps this structure open, to
  1867 accommodate Proof General as well as quick and dirty interactive
  1868 experiments with references.
  1869 
  1870 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1871 parallel tactical reasoning.
  1872 
  1873 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1874 are similar to SUBPROOF, but are slightly more flexible: only the
  1875 specified parts of the subgoal are imported into the context, and the
  1876 body tactic may introduce new subgoals and schematic variables.
  1877 
  1878 * Old tactical METAHYPS, which does not observe the proof context, has
  1879 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1880 or Subgoal.FOCUS etc.
  1881 
  1882 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1883 functors have their own ML name space there is no point to mark them
  1884 separately.)  Minor INCOMPATIBILITY.
  1885 
  1886 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1887 
  1888 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1889 INCOMPATIBILITY.
  1890 
  1891 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1892 mode, which avoids critical setmp.
  1893 
  1894 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1895 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1896 Attrib/Method.setup introduced in Isabelle2009.
  1897 
  1898 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1899 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1900 last resort.  INCOMPATIBILITY.
  1901 
  1902 * Display.pretty_thm now requires a proper context (cf. former
  1903 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1904 or even Display.pretty_thm_without_context as last resort.
  1905 INCOMPATIBILITY.
  1906 
  1907 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1908 Syntax.pretty_typ/term directly, preferably with proper context
  1909 instead of global theory.
  1910 
  1911 
  1912 *** System ***
  1913 
  1914 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1915 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1916 usedir option -q.
  1917 
  1918 * Support for additional "Isabelle components" via etc/components, see
  1919 also the system manual.
  1920 
  1921 * The isabelle makeall tool now operates on all components with
  1922 IsaMakefile, not just hardwired "logics".
  1923 
  1924 * Removed "compress" option from isabelle-process and isabelle usedir;
  1925 this is always enabled.
  1926 
  1927 * Discontinued support for Poly/ML 4.x versions.
  1928 
  1929 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1930 on a given logic image.  This requires the lighttpd webserver and is
  1931 currently supported on Linux only.
  1932 
  1933 
  1934 
  1935 New in Isabelle2009 (April 2009)
  1936 --------------------------------
  1937 
  1938 *** General ***
  1939 
  1940 * Simplified main Isabelle executables, with less surprises on
  1941 case-insensitive file-systems (such as Mac OS).
  1942 
  1943   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1944     "isatool."
  1945 
  1946   - The former "isabelle" alias for "isabelle-process" has been
  1947     removed (should rarely occur to regular users).
  1948 
  1949   - The former "isabelle-interface" and its alias "Isabelle" have been
  1950     removed (interfaces are now regular Isabelle tools).
  1951 
  1952 Within scripts and make files, the Isabelle environment variables
  1953 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1954 respectively.  (The latter are still available as legacy feature.)
  1955 
  1956 The old isabelle-interface wrapper could react in confusing ways if
  1957 the interface was uninstalled or changed otherwise.  Individual
  1958 interface tool configuration is now more explicit, see also the
  1959 Isabelle system manual.  In particular, Proof General is now available
  1960 via "isabelle emacs".
  1961 
  1962 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1963 purge installed copies of Isabelle executables and re-run "isabelle
  1964 install -p ...", or use symlinks.
  1965 
  1966 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1967 old ~/isabelle, which was slightly non-standard and apt to cause
  1968 surprises on case-insensitive file-systems (such as Mac OS).
  1969 
  1970 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1971 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1972 care is required when using older releases of Isabelle.  Note that
  1973 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1974 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1975 
  1976 * Proofs of fully specified statements are run in parallel on
  1977 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1978 a regular 4-core machine, if the initial heap space is made reasonably
  1979 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1980 
  1981 * The main reference manuals ("isar-ref", "implementation", and
  1982 "system") have been updated and extended.  Formally checked references
  1983 as hyperlinks are now available uniformly.
  1984 
  1985 
  1986 *** Pure ***
  1987 
  1988 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1989 respects.  The most important changes are listed below.  See the
  1990 Tutorial on Locales ("locales" manual) for details.
  1991 
  1992 - In locale expressions, instantiation replaces renaming.  Parameters
  1993 must be declared in a for clause.  To aid compatibility with previous
  1994 parameter inheritance, in locale declarations, parameters that are not
  1995 'touched' (instantiation position "_" or omitted) are implicitly added
  1996 with their syntax at the beginning of the for clause.
  1997 
  1998 - Syntax from abbreviations and definitions in locales is available in
  1999 locale expressions and context elements.  The latter is particularly
  2000 useful in locale declarations.
  2001 
  2002 - More flexible mechanisms to qualify names generated by locale
  2003 expressions.  Qualifiers (prefixes) may be specified in locale
  2004 expressions, and can be marked as mandatory (syntax: "name!:") or
  2005 optional (syntax "name?:").  The default depends for plain "name:"
  2006 depends on the situation where a locale expression is used: in
  2007 commands 'locale' and 'sublocale' prefixes are optional, in
  2008 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2009 implicit qualifiers derived from the parameter names of a locale are
  2010 no longer generated.
  2011 
  2012 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2013 instantiation clause in "interpretation" and "interpret" (square
  2014 brackets) is no longer available.  Use locale expressions.
  2015 
  2016 - When converting proof scripts, mandatory qualifiers in
  2017 'interpretation' and 'interpret' should be retained by default, even
  2018 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2019 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2020 in locale expressions range over a single locale instance only.
  2021 
  2022 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2023 In existing theorem specifications replace the includes element by the
  2024 respective context elements of the included locale, omitting those
  2025 that are already present in the theorem specification.  Multiple
  2026 assume elements of a locale should be replaced by a single one
  2027 involving the locale predicate.  In the proof body, declarations (most
  2028 notably theorems) may be regained by interpreting the respective
  2029 locales in the proof context as required (command "interpret").
  2030 
  2031 If using "includes" in replacement of a target solely because the
  2032 parameter types in the theorem are not as general as in the target,
  2033 consider declaring a new locale with additional type constraints on
  2034 the parameters (context element "constrains").
  2035 
  2036 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2037 
  2038 - Locale interpretation commands no longer attempt to simplify goal.
  2039 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2040 methods intro_locales and unfold_locales to clarify.
  2041 
  2042 - Locale interpretation commands no longer accept interpretation
  2043 attributes.  INCOMPATIBILITY.
  2044 
  2045 * Class declaration: so-called "base sort" must not be given in import
  2046 list any longer, but is inferred from the specification.  Particularly
  2047 in HOL, write
  2048 
  2049     class foo = ...
  2050 
  2051 instead of
  2052 
  2053     class foo = type + ...
  2054 
  2055 * Class target: global versions of theorems stemming do not carry a
  2056 parameter prefix any longer.  INCOMPATIBILITY.
  2057 
  2058 * Class 'instance' command no longer accepts attached definitions.
  2059 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2060 
  2061 * Recovered hiding of consts, which was accidentally broken in
  2062 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2063 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2064 
  2065 * Slightly more coherent Pure syntax, with updated documentation in
  2066 isar-ref manual.  Removed locales meta_term_syntax and
  2067 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2068 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2069 directly in regular applications.
  2070 
  2071 * There is a new syntactic category "float_const" for signed decimal
  2072 fractions (e.g. 123.45 or -123.45).
  2073 
  2074 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2075 interface with 'setup' command instead.
  2076 
  2077 * Command 'local_setup' is similar to 'setup', but operates on a local
  2078 theory context.
  2079 
  2080 * The 'axiomatization' command now only works within a global theory
  2081 context.  INCOMPATIBILITY.
  2082 
  2083 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2084 hypotheses.  Sorts required in the course of reasoning need to be
  2085 covered by the constraints in the initial statement, completed by the
  2086 type instance information of the background theory.  Non-trivial sort
  2087 hypotheses, which rarely occur in practice, may be specified via
  2088 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2089 
  2090   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2091 
  2092 The result contains an implicit sort hypotheses as before --
  2093 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2094 normalization.
  2095 
  2096 * Generalized Isar history, with support for linear undo, direct state
  2097 addressing etc.
  2098 
  2099 * Changed defaults for unify configuration options:
  2100 
  2101   unify_trace_bound = 50 (formerly 25)
  2102   unify_search_bound = 60 (formerly 30)
  2103 
  2104 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2105 
  2106   a) On theory merge, the last set of code equations for a particular
  2107      constant is taken (in accordance with the policy applied by other
  2108      parts of the code generator framework).
  2109 
  2110   b) Code equations stemming from explicit declarations (e.g. code
  2111      attribute) gain priority over default code equations stemming
  2112      from definition, primrec, fun etc.
  2113 
  2114 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2115 
  2116 * Unified theorem tables for both code generators.  Thus [code
  2117 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2118 
  2119 * Command 'find_consts' searches for constants based on type and name
  2120 patterns, e.g.
  2121 
  2122     find_consts "_ => bool"
  2123 
  2124 By default, matching is against subtypes, but it may be restricted to
  2125 the whole type.  Searching by name is possible.  Multiple queries are
  2126 conjunctive and queries may be negated by prefixing them with a
  2127 hyphen:
  2128 
  2129     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2130 
  2131 * New 'find_theorems' criterion "solves" matches theorems that
  2132 directly solve the current goal (modulo higher-order unification).
  2133 
  2134 * Auto solve feature for main theorem statements: whenever a new goal
  2135 is stated, "find_theorems solves" is called; any theorems that could
  2136 solve the lemma directly are listed as part of the goal state.
  2137 Cf. associated options in Proof General Isabelle settings menu,
  2138 enabled by default, with reasonable timeout for pathological cases of
  2139 higher-order unification.
  2140 
  2141 
  2142 *** Document preparation ***
  2143 
  2144 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2145 demanding keyword 'by' and supporting the full method expression
  2146 syntax just like the Isar command 'by'.
  2147 
  2148 
  2149 *** HOL ***
  2150 
  2151 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2152 points Main and Complex_Main remain as before.
  2153 
  2154 * Logic image HOL-Plain provides a minimal HOL with the most important
  2155 tools available (inductive, datatype, primrec, ...).  This facilitates
  2156 experimentation and tool development.  Note that user applications
  2157 (and library theories) should never refer to anything below theory
  2158 Main, as before.
  2159 
  2160 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2161 experimentation due to shorter build times.
  2162 
  2163 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2164 were previously part of former HOL-Complex.  Entry point Hyperreal
  2165 remains valid, but theories formerly using Complex_Main should now use
  2166 new entry point Hypercomplex.
  2167 
  2168 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2169 Posix processes.  Avoids potentially expensive forking of the ML
  2170 process.  New thread-based implementation also works on non-Unix
  2171 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2172 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2173 commands are covered in the isar-ref manual.
  2174 
  2175 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2176 sledgehammer without local ATP installation (Vampire etc.). Other
  2177 provers may be included via suitable ML wrappers, see also
  2178 src/HOL/ATP_Linkup.thy.
  2179 
  2180 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2181 menu.
  2182 
  2183 * The metis method no longer fails because the theorem is too trivial
  2184 (contains the empty clause).
  2185 
  2186 * The metis method now fails in the usual manner, rather than raising
  2187 an exception, if it determines that it cannot prove the theorem.
  2188 
  2189 * Method "coherent" implements a prover for coherent logic (see also
  2190 src/Tools/coherent.ML).
  2191 
  2192 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2193 "undefined" is the right choice to replace "arbitrary", though
  2194 logically there is no difference.  INCOMPATIBILITY.
  2195 
  2196 * Command "value" now integrates different evaluation mechanisms.  The
  2197 result of the first successful evaluation mechanism is printed.  In
  2198 square brackets a particular named evaluation mechanisms may be
  2199 specified (currently, [SML], [code] or [nbe]).  See further
  2200 src/HOL/ex/Eval_Examples.thy.
  2201 
  2202 * Normalization by evaluation now allows non-leftlinear equations.
  2203 Declare with attribute [code nbe].
  2204 
  2205 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2206 as the structured Isar versions "cases" and "induct", cf. the
  2207 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2208 are now presented as a list of individual projections
  2209 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2210 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2211 rare situations a different rule is selected --- notably nested tuple
  2212 elimination instead of former prod.exhaust: use explicit (case_tac t
  2213 rule: prod.exhaust) here.
  2214 
  2215 * Attributes "cases", "induct", "coinduct" support "del" option.
  2216 
  2217 * Removed fact "case_split_thm", which duplicates "case_split".
  2218 
  2219 * The option datatype has been moved to a new theory Option.  Renamed
  2220 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2221 
  2222 * New predicate "strict_mono" classifies strict functions on partial
  2223 orders.  With strict functions on linear orders, reasoning about
  2224 (in)equalities is facilitated by theorems "strict_mono_eq",
  2225 "strict_mono_less_eq" and "strict_mono_less".
  2226 
  2227 * Some set operations are now proper qualified constants with
  2228 authentic syntax.  INCOMPATIBILITY:
  2229 
  2230     op Int ~>   Set.Int
  2231     op Un ~>    Set.Un
  2232     INTER ~>    Set.INTER
  2233     UNION ~>    Set.UNION
  2234     Inter ~>    Set.Inter
  2235     Union ~>    Set.Union
  2236     {} ~>       Set.empty
  2237     UNIV ~>     Set.UNIV
  2238 
  2239 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2240 theory Set.
  2241 
  2242 * Auxiliary class "itself" has disappeared -- classes without any
  2243 parameter are treated as expected by the 'class' command.
  2244 
  2245 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2246 
  2247 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2248 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2249 
  2250 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2251 method "approximation".  It proves formulas on real values by using
  2252 interval arithmetic.  In the formulas are also the transcendental
  2253 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2254 allowed. For examples see
  2255 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2256 
  2257 * Theory "Reflection" now resides in HOL/Library.
  2258 
  2259 * Entry point to Word library now simply named "Word".
  2260 INCOMPATIBILITY.
  2261 
  2262 * Made source layout more coherent with logical distribution
  2263 structure:
  2264 
  2265     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2266     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2267     src/HOL/Library/GCD.thy ~> src/HOL/
  2268     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2269     src/HOL/Library/Parity.thy ~> src/HOL/
  2270     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2271     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2272     src/HOL/Real/Lubs.thy ~> src/HOL/
  2273     src/HOL/Real/PReal.thy ~> src/HOL/
  2274     src/HOL/Real/Rational.thy ~> src/HOL/
  2275     src/HOL/Real/RComplete.thy ~> src/HOL/
  2276     src/HOL/Real/RealDef.thy ~> src/HOL/
  2277     src/HOL/Real/RealPow.thy ~> src/HOL/
  2278     src/HOL/Real/Real.thy ~> src/HOL/
  2279     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2280     src/HOL/Complex/Complex.thy ~> src/HOL/
  2281     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2282     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2283     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2284     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2285     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2286     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2287     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2288     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2289     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2290     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2291     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2292     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2293     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2294     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2295     src/HOL/Real/Float ~> src/HOL/Library/
  2296     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2297     src/HOL/Real/RealVector.thy ~> src/HOL/
  2298 
  2299     src/HOL/arith_data.ML ~> src/HOL/Tools
  2300     src/HOL/hologic.ML ~> src/HOL/Tools
  2301     src/HOL/simpdata.ML ~> src/HOL/Tools
  2302     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2303     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2304     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2305     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2306     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2307     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2308     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2309 
  2310     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2311     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2312     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2313     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2314     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2315     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2316 
  2317 * If methods "eval" and "evaluation" encounter a structured proof
  2318 state with !!/==>, only the conclusion is evaluated to True (if
  2319 possible), avoiding strange error messages.
  2320 
  2321 * Method "sizechange" automates termination proofs using (a
  2322 modification of) the size-change principle.  Requires SAT solver.  See
  2323 src/HOL/ex/Termination.thy for examples.
  2324 
  2325 * Simplifier: simproc for let expressions now unfolds if bound
  2326 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2327 
  2328 * Method "arith": Linear arithmetic now ignores all inequalities when
  2329 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2330 
  2331 * New attribute "arith" for facts that should always be used
  2332 automatically by arithmetic. It is intended to be used locally in
  2333 proofs, e.g.
  2334 
  2335   assumes [arith]: "x > 0"
  2336 
  2337 Global usage is discouraged because of possible performance impact.
  2338 
  2339 * New classes "top" and "bot" with corresponding operations "top" and
  2340 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2341 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2342 
  2343 * Changed definition lemma "less_fun_def" in order to provide an
  2344 instance for preorders on functions; use lemma "less_le" instead.
  2345 INCOMPATIBILITY.
  2346 
  2347 * Theory Orderings: class "wellorder" moved here, with explicit
  2348 induction rule "less_induct" as assumption.  For instantiation of
  2349 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2350 INCOMPATIBILITY.
  2351 
  2352 * Theory Orderings: added class "preorder" as superclass of "order".
  2353 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2354 etc. slightly changed.  Some theorems named order_class.* now named
  2355 preorder_class.*.
  2356 
  2357 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2358 "diag" to "Id_on".
  2359 
  2360 * Theory Finite_Set: added a new fold combinator of type
  2361 
  2362   ('a => 'b => 'b) => 'b => 'a set => 'b
  2363 
  2364 Occasionally this is more convenient than the old fold combinator
  2365 which is now defined in terms of the new one and renamed to
  2366 fold_image.
  2367 
  2368 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2369 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2370 extended with further lemmas!).  At the moment both still exist but
  2371 the former will disappear at some point.
  2372 
  2373 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2374 class recpower.  Type-specific simp rules for various recpower types
  2375 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2376 
  2377 rat_power_0    -> power_0
  2378 rat_power_Suc  -> power_Suc
  2379 realpow_0      -> power_0
  2380 realpow_Suc    -> power_Suc
  2381 complexpow_0   -> power_0
  2382 complexpow_Suc -> power_Suc
  2383 power_poly_0   -> power_0
  2384 power_poly_Suc -> power_Suc
  2385 
  2386 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2387 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2388 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2389 of lemmas from Divides has been generalized from nat to class
  2390 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2391 renames resulting from duplicate elimination:
  2392 
  2393     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2394     zero_dvd_iff ~>         dvd_0_left_iff
  2395     dvd_0 ~>                dvd_0_right
  2396     DIVISION_BY_ZERO_DIV ~> div_by_0
  2397     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2398     mult_div ~>             div_mult_self2_is_id
  2399     mult_mod ~>             mod_mult_self2_is_0
  2400 
  2401 * Theory IntDiv: removed many lemmas that are instances of class-based
  2402 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2403 rename old lemmas as follows:
  2404 
  2405 dvd_diff               -> nat_dvd_diff
  2406 dvd_zminus_iff         -> dvd_minus_iff
  2407 mod_add1_eq            -> mod_add_eq
  2408 mod_mult1_eq           -> mod_mult_right_eq
  2409 mod_mult1_eq'          -> mod_mult_left_eq
  2410 mod_mult_distrib_mod   -> mod_mult_eq
  2411 nat_mod_add_left_eq    -> mod_add_left_eq
  2412 nat_mod_add_right_eq   -> mod_add_right_eq
  2413 nat_mod_div_trivial    -> mod_div_trivial
  2414 nat_mod_mod_trivial    -> mod_mod_trivial
  2415 zdiv_zadd_self1        -> div_add_self1
  2416 zdiv_zadd_self2        -> div_add_self2
  2417 zdiv_zmult_self1       -> div_mult_self2_is_id
  2418 zdiv_zmult_self2       -> div_mult_self1_is_id
  2419 zdvd_triv_left         -> dvd_triv_left
  2420 zdvd_triv_right        -> dvd_triv_right
  2421 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2422 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2423 zmod_zadd_left_eq      -> mod_add_left_eq
  2424 zmod_zadd_right_eq     -> mod_add_right_eq
  2425 zmod_zadd_self1        -> mod_add_self1
  2426 zmod_zadd_self2        -> mod_add_self2
  2427 zmod_zadd1_eq          -> mod_add_eq
  2428 zmod_zdiff1_eq         -> mod_diff_eq
  2429 zmod_zdvd_zmod         -> mod_mod_cancel
  2430 zmod_zmod_cancel       -> mod_mod_cancel
  2431 zmod_zmult_self1       -> mod_mult_self2_is_0
  2432 zmod_zmult_self2       -> mod_mult_self1_is_0
  2433 zmod_1                 -> mod_by_1
  2434 zdiv_1                 -> div_by_1
  2435 zdvd_abs1              -> abs_dvd_iff
  2436 zdvd_abs2              -> dvd_abs_iff
  2437 zdvd_refl              -> dvd_refl
  2438 zdvd_trans             -> dvd_trans
  2439 zdvd_zadd              -> dvd_add
  2440 zdvd_zdiff             -> dvd_diff
  2441 zdvd_zminus_iff        -> dvd_minus_iff
  2442 zdvd_zminus2_iff       -> minus_dvd_iff
  2443 zdvd_zmultD            -> dvd_mult_right
  2444 zdvd_zmultD2           -> dvd_mult_left
  2445 zdvd_zmult_mono        -> mult_dvd_mono
  2446 zdvd_0_right           -> dvd_0_right
  2447 zdvd_0_left            -> dvd_0_left_iff
  2448 zdvd_1_left            -> one_dvd
  2449 zminus_dvd_iff         -> minus_dvd_iff
  2450 
  2451 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2452 
  2453 * The real numbers offer decimal input syntax: 12.34 is translated
  2454 into 1234/10^2. This translation is not reversed upon output.
  2455 
  2456 * Theory Library/Polynomial defines an abstract type 'a poly of
  2457 univariate polynomials with coefficients of type 'a.  In addition to
  2458 the standard ring operations, it also supports div and mod.  Code
  2459 generation is also supported, using list-style constructors.
  2460 
  2461 * Theory Library/Inner_Product defines a class of real_inner for real
  2462 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2463 => real.  Class real_inner is a subclass of real_normed_vector from
  2464 theory RealVector.
  2465 
  2466 * Theory Library/Product_Vector provides instances for the product
  2467 type 'a * 'b of several classes from RealVector and Inner_Product.
  2468 Definitions of addition, subtraction, scalar multiplication, norms,
  2469 and inner products are included.
  2470 
  2471 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2472 addition to the field operations, numerals and case syntax are also
  2473 supported.
  2474 
  2475 * Theory Library/Diagonalize provides constructive version of Cantor's
  2476 first diagonalization argument.
  2477 
  2478 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2479 zlcm (for int); carried together from various gcd/lcm developements in
  2480 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2481 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2482 may recover tupled syntax as follows:
  2483 
  2484     hide (open) const gcd
  2485     abbreviation gcd where
  2486       "gcd == (%(a, b). GCD.gcd a b)"
  2487     notation (output)
  2488       GCD.gcd ("gcd '(_, _')")
  2489 
  2490 The same works for lcm, zgcd, zlcm.
  2491 
  2492 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2493 instantiations for algebraic structures.  Removed some duplicate
  2494 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2495 
  2496 * ML antiquotation @{code} takes a constant as argument and generates
  2497 corresponding code in background and inserts name of the corresponding
  2498 resulting ML value/function/datatype constructor binding in place.
  2499 All occurrences of @{code} with a single ML block are generated
  2500 simultaneously.  Provides a generic and safe interface for
  2501 instrumentalizing code generation.  See
  2502 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2503 In future you ought to refrain from ad-hoc compiling generated SML
  2504 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2505 cannot refer to constants for which user-defined serializations are
  2506 set.  Refer to the corresponding ML counterpart directly in that
  2507 cases.
  2508 
  2509 * Command 'rep_datatype': instead of theorem names the command now
  2510 takes a list of terms denoting the constructors of the type to be
  2511 represented as datatype.  The characteristic theorems have to be
  2512 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2513 have disappeared in favour of existing ones:
  2514 
  2515     unit_induct                 ~> unit.induct
  2516     prod_induct                 ~> prod.induct
  2517     sum_induct                  ~> sum.induct
  2518     Suc_Suc_eq                  ~> nat.inject
  2519     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2520 
  2521 
  2522 *** HOL-Algebra ***
  2523 
  2524 * New locales for orders and lattices where the equivalence relation
  2525 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2526 locales use a record structure with field eq for the equivalence.
  2527 
  2528 * New theory of factorial domains.
  2529 
  2530 * Units_l_inv and Units_r_inv are now simp rules by default.
  2531 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2532 and/or r_inv will now also require deletion of these lemmas.
  2533 
  2534 * Renamed the following theorems, INCOMPATIBILITY:
  2535 
  2536 UpperD ~> Upper_memD
  2537 LowerD ~> Lower_memD
  2538 least_carrier ~> least_closed
  2539 greatest_carrier ~> greatest_closed
  2540 greatest_Lower_above ~> greatest_Lower_below
  2541 one_zero ~> carrier_one_zero
  2542 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2543 
  2544 
  2545 *** HOL-Nominal ***
  2546 
  2547 * Nominal datatypes can now contain type-variables.
  2548 
  2549 * Commands 'nominal_inductive' and 'equivariance' work with local
  2550 theory targets.
  2551 
  2552 * Nominal primrec can now works with local theory targets and its
  2553 specification syntax now conforms to the general format as seen in
  2554 'inductive' etc.
  2555 
  2556 * Method "perm_simp" honours the standard simplifier attributes
  2557 (no_asm), (no_asm_use) etc.
  2558 
  2559 * The new predicate #* is defined like freshness, except that on the
  2560 left hand side can be a set or list of atoms.
  2561 
  2562 * Experimental command 'nominal_inductive2' derives strong induction
  2563 principles for inductive definitions.  In contrast to
  2564 'nominal_inductive', which can only deal with a fixed number of
  2565 binders, it can deal with arbitrary expressions standing for sets of
  2566 atoms to be avoided.  The only inductive definition we have at the
  2567 moment that needs this generalisation is the typing rule for Lets in
  2568 the algorithm W:
  2569 
  2570  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2571  -----------------------------------------------------------------
  2572          Gamma |- Let x be t1 in t2 : T2
  2573 
  2574 In this rule one wants to avoid all the binders that are introduced by
  2575 "close Gamma T1".  We are looking for other examples where this
  2576 feature might be useful.  Please let us know.
  2577 
  2578 
  2579 *** HOLCF ***
  2580 
  2581 * Reimplemented the simplification procedure for proving continuity
  2582 subgoals.  The new simproc is extensible; users can declare additional
  2583 continuity introduction rules with the attribute [cont2cont].
  2584 
  2585 * The continuity simproc now uses a different introduction rule for
  2586 solving continuity subgoals on terms with lambda abstractions.  In
  2587 some rare cases the new simproc may fail to solve subgoals that the
  2588 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2589 Potential INCOMPATIBILITY.
  2590 
  2591 * Command 'fixrec': specification syntax now conforms to the general
  2592 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2593 examples.  INCOMPATIBILITY.
  2594 
  2595 
  2596 *** ZF ***
  2597 
  2598 * Proof of Zorn's Lemma for partial orders.
  2599 
  2600 
  2601 *** ML ***
  2602 
  2603 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2604 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2605 depends on multithreading, so timouts will not work before Poly/ML
  2606 5.2.1!
  2607 
  2608 * High-level support for concurrent ML programming, see
  2609 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2610 particularly convenient to organize independent functional
  2611 computations.  The concept of "synchronized variables" provides a
  2612 higher-order interface for components with shared state, avoiding the
  2613 delicate details of mutexes and condition variables.  (Requires
  2614 Poly/ML 5.2.1 or later.)
  2615 
  2616 * ML bindings produced via Isar commands are stored within the Isar
  2617 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2618 become thread-safe and work with undo as expected (concerning
  2619 top-level bindings, not side-effects on global references).
  2620 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2621 compiler at runtime; really global bindings need to be given outside a
  2622 theory.  (Requires Poly/ML 5.2 or later.)
  2623 
  2624 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2625 context.  Top-level ML bindings are stored within the proof context in
  2626 a purely sequential fashion, disregarding the nested proof structure.
  2627 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2628 proof.  (Requires Poly/ML 5.2 or later.)
  2629 
  2630 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2631 and Method.setup, as well as Isar commands 'attribute_setup' and
  2632 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2633 existing code accordingly, or use plain 'setup' together with old
  2634 Method.add_method.
  2635 
  2636 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2637 to 'a -> thm, while results are always tagged with an authentic oracle
  2638 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2639 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2640 accordingly.  Note that extra performance may be gained by producing
  2641 the cterm carefully, avoiding slow Thm.cterm_of.
  2642 
  2643 * Simplified interface for defining document antiquotations via
  2644 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2645 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2646 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2647 examples.
  2648 
  2649 * More systematic treatment of long names, abstract name bindings, and
  2650 name space operations.  Basic operations on qualified names have been
  2651 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2652 Long_Name.append.  Old type bstring has been mostly replaced by
  2653 abstract type binding (see structure Binding), which supports precise
  2654 qualification by packages and local theory targets, as well as proper
  2655 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2656 bstring values into Binding.name, or better pass through abstract
  2657 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2658 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2659 
  2660 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2661 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2662 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2663 
  2664 * Disposed old type and term read functions (Sign.read_def_typ,
  2665 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2666 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2667 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2668 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2669 resort for legacy applications.
  2670 
  2671 * Disposed old declarations, tactics, tactic combinators that refer to
  2672 the simpset or claset of an implicit theory (such as Addsimps,
  2673 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2674 embedded ML text, or local_simpset_of with a proper context passed as
  2675 explicit runtime argument.
  2676 
  2677 * Rules and tactics that read instantiations (read_instantiate,
  2678 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2679 context, which is required for parsing and type-checking.  Moreover,
  2680 the variables are specified as plain indexnames, not string encodings
  2681 thereof.  INCOMPATIBILITY.
  2682 
  2683 * Generic Toplevel.add_hook interface allows to analyze the result of
  2684 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2685 for theorem dependency output of transactions resulting in a new
  2686 theory state.
  2687 
  2688 * ML antiquotations: block-structured compilation context indicated by
  2689 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2690 
  2691   @{binding name}                         - basic name binding
  2692   @{let ?pat = term}                      - term abbreviation (HO matching)
  2693   @{note name = fact}                     - fact abbreviation
  2694   @{thm fact}                             - singleton fact (with attributes)
  2695   @{thms fact}                            - general fact (with attributes)
  2696   @{lemma prop by method}                 - singleton goal
  2697   @{lemma prop by meth1 meth2}            - singleton goal
  2698   @{lemma prop1 ... propN by method}      - general goal
  2699   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2700   @{lemma (open) ...}                     - open derivation
  2701 
  2702 
  2703 *** System ***
  2704 
  2705 * The Isabelle "emacs" tool provides a specific interface to invoke
  2706 Proof General / Emacs, with more explicit failure if that is not
  2707 installed (the old isabelle-interface script silently falls back on
  2708 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2709 installation location of the Proof General distribution.
  2710 
  2711 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2712 the Isabelle process into a JVM/Scala application.  See
  2713 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2714 process wrapper has been discontinued.)
  2715 
  2716 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2717 
  2718 * Various status messages (with exact source position information) are
  2719 emitted, if proper markup print mode is enabled.  This allows
  2720 user-interface components to provide detailed feedback on internal
  2721 prover operations.
  2722 
  2723 
  2724 
  2725 New in Isabelle2008 (June 2008)
  2726 -------------------------------
  2727 
  2728 *** General ***
  2729 
  2730 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2731 and updated, with formally checked references as hyperlinks.
  2732 
  2733 * Theory loader: use_thy (and similar operations) no longer set the
  2734 implicit ML context, which was occasionally hard to predict and in
  2735 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2736 provides a proper context already.
  2737 
  2738 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2739 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2740 'use' within a theory file will do the job.
  2741 
  2742 * Name space merge now observes canonical order, i.e. the second space
  2743 is inserted into the first one, while existing entries in the first
  2744 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2745 swap theory imports.
  2746 
  2747 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2748 INCOMPATIBILITY in identifier syntax etc.
  2749 
  2750 * Outer syntax: string tokens no longer admit escaped white space,
  2751 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2752 white space without escapes.
  2753 
  2754 * Outer syntax: string tokens may contain arbitrary character codes
  2755 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2756 "foo_bar".
  2757 
  2758 
  2759 *** Pure ***
  2760 
  2761 * Context-dependent token translations.  Default setup reverts locally
  2762 fixed variables, and adds hilite markup for undeclared frees.
  2763 
  2764 * Unused theorems can be found using the new command 'unused_thms'.
  2765 There are three ways of invoking it:
  2766 
  2767 (1) unused_thms
  2768      Only finds unused theorems in the current theory.
  2769 
  2770 (2) unused_thms thy_1 ... thy_n -
  2771      Finds unused theorems in the current theory and all of its ancestors,
  2772      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2773 
  2774 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2775      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2776      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2777      their ancestors.
  2778 
  2779 In order to increase the readability of the list produced by
  2780 unused_thms, theorems that have been created by a particular instance
  2781 of a theory command such as 'inductive' or 'function' are considered
  2782 to belong to the same "group", meaning that if at least one theorem in
  2783 this group is used, the other theorems in the same group are no longer
  2784 reported as unused.  Moreover, if all theorems in the group are
  2785 unused, only one theorem in the group is displayed.
  2786 
  2787 Note that proof objects have to be switched on in order for
  2788 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2789 usually the case when using Proof General with the default settings).
  2790 
  2791 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2792 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2793 duplicate fact bindings, or even accidental fact duplications.  Note
  2794 that tools may maintain dynamically scoped facts systematically, using
  2795 PureThy.add_thms_dynamic.
  2796 
  2797 * Command 'hide' now allows to hide from "fact" name space as well.
  2798 
  2799 * Eliminated destructive theorem database, simpset, claset, and
  2800 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2801 update of theories within ML code.
  2802 
  2803 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2804 INCOMPATIBILITY, object-logics depending on former Pure require
  2805 additional setup PureThy.old_appl_syntax_setup; object-logics
  2806 depending on former CPure need to refer to Pure.
  2807 
  2808 * Commands 'use' and 'ML' are now purely functional, operating on
  2809 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2810 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2811 INCOMPATIBILITY.
  2812 
  2813 * Command 'setup': discontinued implicit version with ML reference.
  2814 
  2815 * Instantiation target allows for simultaneous specification of class
  2816 instance operations together with an instantiation proof.
  2817 Type-checking phase allows to refer to class operations uniformly.
  2818 See src/HOL/Complex/Complex.thy for an Isar example and
  2819 src/HOL/Library/Eval.thy for an ML example.
  2820 
  2821 * Indexing of literal facts: be more serious about including only
  2822 facts from the visible specification/proof context, but not the
  2823 background context (locale etc.).  Affects `prop` notation and method
  2824 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2825 situations.
  2826 
  2827 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2828 "(open)" option, which used to expose internal bound variables to the
  2829 proof text.
  2830 
  2831 * Isar statements: removed obsolete case "rule_context".
  2832 INCOMPATIBILITY, better use explicit fixes/assumes.
  2833 
  2834 * Locale proofs: default proof step now includes 'unfold_locales';
  2835 hence 'proof' without argument may be used to unfold locale
  2836 predicates.
  2837 
  2838 
  2839 *** Document preparation ***
  2840 
  2841 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2842 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2843 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2844 spot); renamed link color from "darkblue" to "linkcolor" (default
  2845 value unchanged, can be redefined via \definecolor); no longer sets
  2846 "a4paper" option (unnecessary or even intrusive).
  2847 
  2848 * Antiquotation @{lemma A method} proves proposition A by the given
  2849 method (either a method name or a method name plus (optional) method
  2850 arguments in parentheses) and prints A just like @{prop A}.
  2851 
  2852 
  2853 *** HOL ***
  2854 
  2855 * New primrec package.  Specification syntax conforms in style to
  2856 definition/function/....  No separate induction rule is provided.  The
  2857 "primrec" command distinguishes old-style and new-style specifications
  2858 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2859 When adjusting theories, beware: constants stemming from new-style
  2860 primrec specifications have authentic syntax.
  2861 
  2862 * Metis prover is now an order of magnitude faster, and also works
  2863 with multithreading.
  2864 
  2865 * Metis: the maximum number of clauses that can be produced from a
  2866 theorem is now given by the attribute max_clauses.  Theorems that
  2867 exceed this number are ignored, with a warning printed.
  2868 
  2869 * Sledgehammer no longer produces structured proofs by default. To
  2870 enable, declare [[sledgehammer_full = true]].  Attributes
  2871 reconstruction_modulus, reconstruction_sorts renamed
  2872 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2873 
  2874 * Method "induct_scheme" derives user-specified induction rules
  2875 from well-founded induction and completeness of patterns. This factors
  2876 out some operations that are done internally by the function package
  2877 and makes them available separately.  See
  2878 src/HOL/ex/Induction_Scheme.thy for examples.
  2879 
  2880 * More flexible generation of measure functions for termination
  2881 proofs: Measure functions can be declared by proving a rule of the
  2882 form "is_measure f" and giving it the [measure_function] attribute.
  2883 The "is_measure" predicate is logically meaningless (always true), and
  2884 just guides the heuristic.  To find suitable measure functions, the
  2885 termination prover sets up the goal "is_measure ?f" of the appropriate
  2886 type and generates all solutions by prolog-style backwards proof using
  2887 the declared rules.
  2888 
  2889 This setup also deals with rules like 
  2890 
  2891   "is_measure f ==> is_measure (list_size f)"
  2892 
  2893 which accommodates nested datatypes that recurse through lists.
  2894 Similar rules are predeclared for products and option types.
  2895 
  2896 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2897 
  2898   INCOMPATIBILITIES:
  2899 
  2900   - Definitions of overloaded constants on sets have to be replaced by
  2901     definitions on => and bool.
  2902 
  2903   - Some definitions of overloaded operators on sets can now be proved
  2904     using the definitions of the operators on => and bool.  Therefore,
  2905     the following theorems have been renamed:
  2906 
  2907       subset_def   -> subset_eq
  2908       psubset_def  -> psubset_eq
  2909       set_diff_def -> set_diff_eq
  2910       Compl_def    -> Compl_eq
  2911       Sup_set_def  -> Sup_set_eq
  2912       Inf_set_def  -> Inf_set_eq
  2913       sup_set_def  -> sup_set_eq
  2914       inf_set_def  -> inf_set_eq
  2915 
  2916   - Due to the incompleteness of the HO unification algorithm, some
  2917     rules such as subst may require manual instantiation, if some of
  2918     the unknowns in the rule is a set.
  2919 
  2920   - Higher order unification and forward proofs:
  2921     The proof pattern
  2922 
  2923       have "P (S::'a set)" <...>
  2924       then have "EX S. P S" ..
  2925 
  2926     no longer works (due to the incompleteness of the HO unification
  2927     algorithm) and must be replaced by the pattern
  2928 
  2929       have "EX S. P S"
  2930       proof
  2931         show "P S" <...>
  2932       qed
  2933 
  2934   - Calculational reasoning with subst (or similar rules):
  2935     The proof pattern
  2936 
  2937       have "P (S::'a set)" <...>
  2938       also have "S = T" <...>
  2939       finally have "P T" .
  2940 
  2941     no longer works (for similar reasons as the previous example) and
  2942     must be replaced by something like
  2943 
  2944       have "P (S::'a set)" <...>
  2945       moreover have "S = T" <...>
  2946       ultimately have "P T" by simp
  2947 
  2948   - Tactics or packages written in ML code:
  2949     Code performing pattern matching on types via
  2950 
  2951       Type ("set", [T]) => ...
  2952 
  2953     must be rewritten. Moreover, functions like strip_type or
  2954     binder_types no longer return the right value when applied to a
  2955     type of the form
  2956 
  2957       T1 => ... => Tn => U => bool
  2958 
  2959     rather than
  2960 
  2961       T1 => ... => Tn => U set
  2962 
  2963 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2964 Wellfounded_Relations to theory Wellfounded.
  2965 
  2966 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2967 
  2968 * Class finite no longer treats UNIV as class parameter.  Use class
  2969 enum from theory Library/Enum instead to achieve a similar effect.
  2970 INCOMPATIBILITY.
  2971 
  2972 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2973 and "Cons".  INCOMPATIBILITY.
  2974 
  2975 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2976 Potential INCOMPATIBILITY.
  2977 
  2978 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2979 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2980 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2981 
  2982 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2983 the same name in theory Orderings:
  2984 
  2985   less_trans
  2986   less_linear
  2987   le_imp_less_or_eq
  2988   le_less_trans
  2989   less_le_trans
  2990   less_not_sym
  2991   less_asym
  2992 
  2993 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2994 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2995 and different variable names.
  2996 
  2997 * Library/Option_ord.thy: Canonical order on option type.
  2998 
  2999 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3000 finite maps.
  3001 
  3002 * Library/Countable.thy: Type class for countable types.
  3003 
  3004 * Theory Int: The representation of numerals has changed.  The infix
  3005 operator BIT and the bit datatype with constructors B0 and B1 have
  3006 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3007 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3008 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3009 accordingly.
  3010 
  3011 * Theory Nat: definition of <= and < on natural numbers no longer
  3012 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3013 le_def and less_def have disappeared.  Consider lemmas not_less
  3014 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3015 
  3016 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3017 (whose purpose mainly is for various fold_set functionals) have been
  3018 abandoned in favor of the existing algebraic classes
  3019 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3020 lower_semilattice (resp. upper_semilattice) and linorder.
  3021 INCOMPATIBILITY.
  3022 
  3023 * Theory Transitive_Closure: induct and cases rules now declare proper
  3024 case_names ("base" and "step").  INCOMPATIBILITY.
  3025 
  3026 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3027 lattices.  The form set-specific version is available as
  3028 Inductive.lfp_ordinal_induct_set.
  3029 
  3030 * Renamed theorems "power.simps" to "power_int.simps".
  3031 INCOMPATIBILITY.
  3032 
  3033 * Class semiring_div provides basic abstract properties of semirings
  3034 with division and modulo operations.  Subsumes former class dvd_mod.
  3035 
  3036 * Merged theories IntDef, Numeral and IntArith into unified theory
  3037 Int.  INCOMPATIBILITY.
  3038 
  3039 * Theory Library/Code_Index: type "index" now represents natural
  3040 numbers rather than integers.  INCOMPATIBILITY.
  3041 
  3042 * New class "uminus" with operation "uminus" (split of from class
  3043 "minus" which now only has operation "minus", binary).
  3044 INCOMPATIBILITY.
  3045 
  3046 * Constants "card", "internal_split", "option_map" now with authentic
  3047 syntax.  INCOMPATIBILITY.
  3048 
  3049 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3050 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3051 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3052 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3053 Sup_set_def, le_def, less_def, option_map_def now with object
  3054 equality.  INCOMPATIBILITY.
  3055 
  3056 * Records. Removed K_record, and replaced it by pure lambda term
  3057 %x. c. The simplifier setup is now more robust against eta expansion.
  3058 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3059 
  3060 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3061 
  3062 * Library/ListVector: new theory of arithmetic vector operations.
  3063 
  3064 * Library/Order_Relation: new theory of various orderings as sets of
  3065 pairs.  Defines preorders, partial orders, linear orders and
  3066 well-orders on sets and on types.
  3067 
  3068 
  3069 *** ZF ***
  3070 
  3071 * Renamed some theories to allow to loading both ZF and HOL in the
  3072 same session:
  3073 
  3074   Datatype  -> Datatype_ZF
  3075   Inductive -> Inductive_ZF
  3076   Int       -> Int_ZF
  3077   IntDiv    -> IntDiv_ZF
  3078   Nat       -> Nat_ZF
  3079   List      -> List_ZF
  3080   Main      -> Main_ZF
  3081 
  3082 INCOMPATIBILITY: ZF theories that import individual theories below
  3083 Main might need to be adapted.  Regular theory Main is still
  3084 available, as trivial extension of Main_ZF.
  3085 
  3086 
  3087 *** ML ***
  3088 
  3089 * ML within Isar: antiquotation @{const name} or @{const
  3090 name(typargs)} produces statically-checked Const term.
  3091 
  3092 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3093 (of the same name).  Removed obsolete print command.
  3094 
  3095 * Removed obsolete "use_legacy_bindings" function.
  3096 
  3097 * The ``print mode'' is now a thread-local value derived from a global
  3098 template (the former print_mode reference), thus access becomes
  3099 non-critical.  The global print_mode reference is for session
  3100 management only; user-code should use print_mode_value,
  3101 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3102 
  3103 * Functions system/system_out provide a robust way to invoke external
  3104 shell commands, with propagation of interrupts (requires Poly/ML
  3105 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3106 
  3107 
  3108 *** System ***
  3109 
  3110 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3111 in accordance with Proof General 3.7, which prefers GNU emacs.
  3112 
  3113 * isatool tty runs Isabelle process with plain tty interaction;
  3114 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3115 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3116 
  3117 * isatool browser now works with Cygwin as well, using general
  3118 "javapath" function defined in Isabelle process environment.
  3119 
  3120 * YXML notation provides a simple and efficient alternative to
  3121 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3122 isatool yxml as described in the Isabelle system manual.
  3123 
  3124 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3125 provides general wrapper for managing an Isabelle process in a robust
  3126 fashion, with ``cooked'' output from stdin/stderr.
  3127 
  3128 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3129 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3130 
  3131 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3132 way of changing the user's settings is via
  3133 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3134 script.
  3135 
  3136 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3137 cores of the underlying machine, which is a good starting point for
  3138 optimal performance tuning.  The corresponding usedir option -M allows
  3139 "max" as an alias for "0".  WARNING: does not work on certain versions
  3140 of Mac OS (with Poly/ML 5.1).
  3141 
  3142 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3143 adverse effect of Isabelle flooding interactive front-ends (notably
  3144 ProofGeneral / XEmacs).
  3145 
  3146 
  3147 
  3148 New in Isabelle2007 (November 2007)
  3149 -----------------------------------
  3150 
  3151 *** General ***
  3152 
  3153 * More uniform information about legacy features, notably a
  3154 warning/error of "Legacy feature: ...", depending on the state of the
  3155 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3156 legacy features will disappear eventually.
  3157 
  3158 * Theory syntax: the header format ``theory A = B + C:'' has been
  3159 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3160 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3161 
  3162 * Theory syntax: the old non-Isar theory file format has been
  3163 discontinued altogether.  Note that ML proof scripts may still be used
  3164 with Isar theories; migration is usually quite simple with the ML
  3165 function use_legacy_bindings.  INCOMPATIBILITY.
  3166 
  3167 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3168 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3169 quotes.
  3170 
  3171 * Theory loader: be more serious about observing the static theory
  3172 header specifications (including optional directories), but not the
  3173 accidental file locations of previously successful loads.  The strict
  3174 update policy of former update_thy is now already performed by
  3175 use_thy, so the former has been removed; use_thys updates several
  3176 theories simultaneously, just as 'imports' within a theory header
  3177 specification, but without merging the results.  Potential
  3178 INCOMPATIBILITY: may need to refine theory headers and commands
  3179 ROOT.ML which depend on load order.
  3180 
  3181 * Theory loader: optional support for content-based file
  3182 identification, instead of the traditional scheme of full physical
  3183 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3184 (cf. the system manual).  The new scheme allows to work with
  3185 non-finished theories in persistent session images, such that source
  3186 files may be moved later on without requiring reloads.
  3187 
  3188 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3189 file (with the same base name as the theory) are considered a legacy
  3190 feature, which will disappear eventually. Even now, the theory loader
  3191 no longer maintains dependencies on such files.
  3192 
  3193 * Syntax: the scope for resolving ambiguities via type-inference is
  3194 now limited to individual terms, instead of whole simultaneous
  3195 specifications as before. This greatly reduces the complexity of the
  3196 syntax module and improves flexibility by separating parsing and
  3197 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3198 'fixes' etc.) are required in rare situations.
  3199 
  3200 * Syntax: constants introduced by new-style packages ('definition',
  3201 'abbreviation' etc.) are passed through the syntax module in
  3202 ``authentic mode''. This means that associated mixfix annotations
  3203 really stick to such constants, independently of potential name space
  3204 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3205 trees are represented slightly differently, may need to adapt syntax
  3206 translations accordingly. Use CONST marker in 'translations' and
  3207 @{const_syntax} antiquotation in 'parse_translation' etc.
  3208 
  3209 * Legacy goal package: reduced interface to the bare minimum required
  3210 to keep existing proof scripts running.  Most other user-level
  3211 functions are now part of the OldGoals structure, which is *not* open
  3212 by default (consider isatool expandshort before open OldGoals).
  3213 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3214 these tend to cause confusion about the actual goal (!) context being
  3215 used here, which is not necessarily the same as the_context().
  3216 
  3217 * Command 'find_theorems': supports "*" wild-card in "name:"
  3218 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3219 support a specific search form (see ProofGeneral/CHANGES).
  3220 
  3221 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3222 by default, which means that "prems" (and also "fixed variables") are
  3223 suppressed from proof state output.  Note that the ProofGeneral
  3224 settings mechanism allows to change and save options persistently, but
  3225 older versions of Isabelle will fail to start up if a negative prems
  3226 limit is imposed.
  3227 
  3228 * Local theory targets may be specified by non-nested blocks of
  3229 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3230 contain definitions, theorems etc., including any derived mechanism
  3231 that has been implemented on top of these primitives.  This concept
  3232 generalizes the existing ``theorem (in ...)'' towards more versatility
  3233 and scalability.
  3234 
  3235 * Proof General interface: proper undo of final 'end' command;
  3236 discontinued Isabelle/classic mode (ML proof scripts).
  3237 
  3238 
  3239 *** Document preparation ***
  3240 
  3241 * Added antiquotation @{theory name} which prints the given name,
  3242 after checking that it refers to a valid ancestor theory in the
  3243 current context.
  3244 
  3245 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3246 check the given source text as ML type/structure, printing verbatim.
  3247 
  3248 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3249 "c args == rhs" given in the current context.  (Any number of
  3250 arguments may be given on the LHS.)
  3251 
  3252 
  3253 *** Pure ***
  3254 
  3255 * The 'class' package offers a combination of axclass and locale to
  3256 achieve Haskell-like type classes in Isabelle.  Definitions and
  3257 theorems within a class context produce both relative results (with
  3258 implicit parameters according to the locale context), and polymorphic
  3259 constants with qualified polymorphism (according to the class
  3260 context).  Within the body context of a 'class' target, a separate
  3261 syntax layer ("user space type system") takes care of converting
  3262 between global polymorphic consts and internal locale representation.
  3263 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3264 "isatool doc classes" provides a tutorial.
  3265 
  3266 * Generic code generator framework allows to generate executable
  3267 code for ML and Haskell (including Isabelle classes).  A short usage
  3268 sketch:
  3269 
  3270     internal compilation:
  3271         export_code <list of constants (term syntax)> in SML
  3272     writing SML code to a file:
  3273         export_code <list of constants (term syntax)> in SML <filename>
  3274     writing OCaml code to a file:
  3275         export_code <list of constants (term syntax)> in OCaml <filename>
  3276     writing Haskell code to a bunch of files:
  3277         export_code <list of constants (term syntax)> in Haskell <filename>
  3278 
  3279     evaluating closed propositions to True/False using code generation:
  3280         method ``eval''
  3281 
  3282 Reasonable default setup of framework in HOL.
  3283 
  3284 Theorem attributs for selecting and transforming function equations theorems:
  3285 
  3286     [code fun]:        select a theorem as function equation for a specific constant
  3287     [code fun del]:    deselect a theorem as function equation for a specific constant
  3288     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3289     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3290 
  3291 User-defined serializations (target in {SML, OCaml, Haskell}):
  3292 
  3293     code_const <and-list of constants (term syntax)>
  3294       {(target) <and-list of const target syntax>}+
  3295 
  3296     code_type <and-list of type constructors>
  3297       {(target) <and-list of type target syntax>}+
  3298 
  3299     code_instance <and-list of instances>
  3300       {(target)}+
  3301         where instance ::= <type constructor> :: <class>
  3302 
  3303     code_class <and_list of classes>
  3304       {(target) <and-list of class target syntax>}+
  3305         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3306 
  3307 code_instance and code_class only are effective to target Haskell.
  3308 
  3309 For example usage see src/HOL/ex/Codegenerator.thy and
  3310 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3311 generation from Isabelle/HOL theories is available via "isatool doc
  3312 codegen".
  3313 
  3314 * Code generator: consts in 'consts_code' Isar commands are now
  3315 referred to by usual term syntax (including optional type
  3316 annotations).
  3317 
  3318 * Command 'no_translations' removes translation rules from theory
  3319 syntax.
  3320 
  3321 * Overloaded definitions are now actually checked for acyclic
  3322 dependencies.  The overloading scheme is slightly more general than
  3323 that of Haskell98, although Isabelle does not demand an exact
  3324 correspondence to type class and instance declarations.
  3325 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3326 exotic versions of overloading -- at the discretion of the user!
  3327 
  3328 Polymorphic constants are represented via type arguments, i.e. the
  3329 instantiation that matches an instance against the most general
  3330 declaration given in the signature.  For example, with the declaration
  3331 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3332 as c(nat).  Overloading is essentially simultaneous structural
  3333 recursion over such type arguments.  Incomplete specification patterns
  3334 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3335 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3336 Command 'print_theory' outputs the normalized system of recursive
  3337 equations, see section "definitions".
  3338 
  3339 * Configuration options are maintained within the theory or proof
  3340 context (with name and type bool/int/string), providing a very simple
  3341 interface to a poor-man's version of general context data.  Tools may
  3342 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3343 these values using Config.get etc.  Users may change options via an
  3344 associated attribute of the same name.  This form of context
  3345 declaration works particularly well with commands 'declare' or
  3346 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3347 very easy to avoid global references, which would not observe Isar
  3348 toplevel undo/redo and fail to work with multithreading.
  3349 
  3350 Various global ML references of Pure and HOL have been turned into
  3351 configuration options:
  3352 
  3353   Unify.search_bound		unify_search_bound
  3354   Unify.trace_bound		unify_trace_bound
  3355   Unify.trace_simp		unify_trace_simp
  3356   Unify.trace_types		unify_trace_types
  3357   Simplifier.simp_depth_limit	simp_depth_limit
  3358   Blast.depth_limit		blast_depth_limit
  3359   DatatypeProp.dtK		datatype_distinctness_limit
  3360   fast_arith_neq_limit  	fast_arith_neq_limit
  3361   fast_arith_split_limit	fast_arith_split_limit
  3362 
  3363 * Named collections of theorems may be easily installed as context
  3364 data using the functor NamedThmsFun (see also
  3365 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3366 attributes; there is also a toplevel print command.  This facility is
  3367 just a common case of general context data, which is the preferred way
  3368 for anything more complex than just a list of facts in canonical
  3369 order.
  3370 
  3371 * Isar: command 'declaration' augments a local theory by generic
  3372 declaration functions written in ML.  This enables arbitrary content
  3373 being added to the context, depending on a morphism that tells the
  3374 difference of the original declaration context wrt. the application
  3375 context encountered later on.
  3376 
  3377 * Isar: proper interfaces for simplification procedures.  Command
  3378 'simproc_setup' declares named simprocs (with match patterns, and body
  3379 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3380 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3381 
  3382 * Isar: an extra pair of brackets around attribute declarations
  3383 abbreviates a theorem reference involving an internal dummy fact,
  3384 which will be ignored later --- only the effect of the attribute on
  3385 the background context will persist.  This form of in-place
  3386 declarations is particularly useful with commands like 'declare' and
  3387 'using', for example ``have A using [[simproc a]] by simp''.
  3388 
  3389 * Isar: method "assumption" (and implicit closing of subproofs) now
  3390 takes simple non-atomic goal assumptions into account: after applying
  3391 an assumption as a rule the resulting subgoals are solved by atomic
  3392 assumption steps.  This is particularly useful to finish 'obtain'
  3393 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3394 without referring to the original premise "!!x. P x ==> thesis" in the
  3395 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3396 more permissive.
  3397 
  3398 * Isar: implicit use of prems from the Isar proof context is
  3399 considered a legacy feature.  Common applications like ``have A .''
  3400 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3401 referencing facts explicitly here improves readability and
  3402 maintainability of proof texts.
  3403 
  3404 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3405 the obtained context from the course of reasoning!  For example:
  3406 
  3407   assume "EX x y. A x & B y"   -- "any previous fact"
  3408   then guess x and y by clarify
  3409 
  3410 This technique is potentially adventurous, depending on the facts and
  3411 proof tools being involved here.
  3412 
  3413 * Isar: known facts from the proof context may be specified as literal
  3414 propositions, using ASCII back-quote syntax.  This works wherever
  3415 named facts used to be allowed so far, in proof commands, proof
  3416 methods, attributes etc.  Literal facts are retrieved from the context
  3417 according to unification of type and term parameters.  For example,
  3418 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3419 theorems in the current context, then these are valid literal facts:
  3420 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3421 
  3422 There is also a proof method "fact" which does the same composition
  3423 for explicit goal states, e.g. the following proof texts coincide with
  3424 certain special cases of literal facts:
  3425 
  3426   have "A" by fact                 ==  note `A`
  3427   have "A ==> B" by fact           ==  note `A ==> B`
  3428   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3429   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3430 
  3431 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3432 outer syntax.  Thus symbolic identifiers may be used without
  3433 additional white space in declarations like this: ``assume *: A''.
  3434 
  3435 * Isar: 'print_facts' prints all local facts of the current context,
  3436 both named and unnamed ones.
  3437 
  3438 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3439 
  3440   def x == "t" and y == "u"
  3441 
  3442 * Isar: added command 'unfolding', which is structurally similar to
  3443 'using', but affects both the goal state and facts by unfolding given
  3444 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3445 'unfolded' attribute may be replaced by first-class proof text.
  3446 
  3447 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3448 and command 'unfolding' now all support object-level equalities
  3449 (potentially conditional).  The underlying notion of rewrite rule is
  3450 analogous to the 'rule_format' attribute, but *not* that of the
  3451 Simplifier (which is usually more generous).
  3452 
  3453 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3454 premises of a theorem by n. Useful in conjunction with drule.
  3455 
  3456 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3457 method expression within a sandbox consisting of the first N
  3458 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3459 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3460 simplifies all new goals that emerge from applying rule foo to the
  3461 originally first one.
  3462 
  3463 * Isar: schematic goals are no longer restricted to higher-order
  3464 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3465 expected.
  3466 
  3467 * Isar: the conclusion of a long theorem statement is now either
  3468 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3469 (essentially a disjunction of cases with local parameters and
  3470 assumptions).  The latter allows to express general elimination rules
  3471 adequately; in this notation common elimination rules look like this:
  3472 
  3473   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3474     assumes "EX x. P x"
  3475     obtains x where "P x"
  3476 
  3477   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3478     assumes "A & B"
  3479     obtains A and B
  3480 
  3481   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3482     assumes "A | B"
  3483     obtains
  3484       A
  3485     | B
  3486 
  3487 The subsequent classical rules even refer to the formal "thesis"
  3488 explicitly:
  3489 
  3490   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3491     obtains "~ thesis"
  3492 
  3493   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3494     obtains "thesis ==> something"
  3495 
  3496 The actual proof of an 'obtains' statement is analogous to that of the
  3497 Isar proof element 'obtain', only that there may be several cases.
  3498 Optional case names may be specified in parentheses; these will be
  3499 available both in the present proof and as annotations in the
  3500 resulting rule, for later use with the 'cases' method (cf. attribute
  3501 case_names).
  3502 
  3503 * Isar: the assumptions of a long theorem statement are available as
  3504 "assms" fact in the proof context.  This is more appropriate than the
  3505 (historical) "prems", which refers to all assumptions of the current
  3506 context, including those from the target locale, proof body etc.
  3507 
  3508 * Isar: 'print_statement' prints theorems from the current theory or
  3509 proof context in long statement form, according to the syntax of a
  3510 top-level lemma.
  3511 
  3512 * Isar: 'obtain' takes an optional case name for the local context
  3513 introduction rule (default "that").
  3514 
  3515 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3516 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3517 to occur.
  3518 
  3519 * Pure: syntax "CONST name" produces a fully internalized constant
  3520 according to the current context.  This is particularly useful for
  3521 syntax translations that should refer to internal constant
  3522 representations independently of name spaces.
  3523 
  3524 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3525 instead of "FOO ". This allows multiple binder declarations to coexist
  3526 in the same context.  INCOMPATIBILITY.
  3527 
  3528 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3529 primitive that also works in a locale context (both for constants and
  3530 fixed variables). Type declaration and internal syntactic representation
  3531 of given constants retrieved from the context. Likewise, the
  3532 'no_notation' command allows to remove given syntax annotations from the
  3533 current context.
  3534 
  3535 * Isar/locales: new derived specification elements 'axiomatization',
  3536 'definition', 'abbreviation', which support type-inference, admit
  3537 object-level specifications (equality, equivalence).  See also the
  3538 isar-ref manual.  Examples:
  3539 
  3540   axiomatization
  3541     eq  (infix "===" 50) where
  3542     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3543 
  3544   definition "f x y = x + y + 1"
  3545   definition g where "g x = f x x"
  3546 
  3547   abbreviation
  3548     neq  (infix "=!=" 50) where
  3549     "x =!= y == ~ (x === y)"
  3550 
  3551 These specifications may be also used in a locale context.  Then the
  3552 constants being introduced depend on certain fixed parameters, and the
  3553 constant name is qualified by the locale base name.  An internal
  3554 abbreviation takes care for convenient input and output, making the
  3555 parameters implicit and using the original short name.  See also
  3556 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3557 entities from a monomorphic theory.
  3558 
  3559 Presently, abbreviations are only available 'in' a target locale, but
  3560 not inherited by general import expressions.  Also note that
  3561 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3562 'translations' in common applications.  The "no_abbrevs" print mode
  3563 prevents folding of abbreviations in term output.
  3564 
  3565 Concrete syntax is attached to specified constants in internal form,
  3566 independently of name spaces.  The parse tree representation is
  3567 slightly different -- use 'notation' instead of raw 'syntax', and
  3568 'translations' with explicit "CONST" markup to accommodate this.
  3569 
  3570 * Pure/Isar: unified syntax for new-style specification mechanisms
  3571 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3572 full type inference and dummy patterns ("_").  For example:
  3573 
  3574   definition "K x _ = x"
  3575 
  3576   inductive conj for A B
  3577   where "A ==> B ==> conj A B"
  3578 
  3579 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3580 the current context.  Print mode "no_abbrevs" prevents inversion of
  3581 abbreviations on output.
  3582 
  3583 * Isar/locales: improved parameter handling: use of locales "var" and
  3584 "struct" no longer necessary; - parameter renamings are no longer
  3585 required to be injective.  For example, this allows to define
  3586 endomorphisms as locale endom = homom mult mult h.
  3587 
  3588 * Isar/locales: changed the way locales with predicates are defined.
  3589 Instead of accumulating the specification, the imported expression is
  3590 now an interpretation.  INCOMPATIBILITY: different normal form of
  3591 locale expressions.  In particular, in interpretations of locales with
  3592 predicates, goals repesenting already interpreted fragments are not
  3593 removed automatically.  Use methods `intro_locales' and
  3594 `unfold_locales'; see below.
  3595 
  3596 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3597 provide backward reasoning on locales predicates.  The methods are
  3598 aware of interpretations and discharge corresponding goals.
  3599 `intro_locales' is less aggressive then `unfold_locales' and does not
  3600 unfold predicates to assumptions.
  3601 
  3602 * Isar/locales: the order in which locale fragments are accumulated
  3603 has changed.  This enables to override declarations from fragments due
  3604 to interpretations -- for example, unwanted simp rules.
  3605 
  3606 * Isar/locales: interpretation in theories and proof contexts has been
  3607 extended.  One may now specify (and prove) equations, which are
  3608 unfolded in interpreted theorems.  This is useful for replacing
  3609 defined concepts (constants depending on locale parameters) by
  3610 concepts already existing in the target context.  Example:
  3611 
  3612   interpretation partial_order ["op <= :: [int, int] => bool"]
  3613     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3614 
  3615 Typically, the constant `partial_order.less' is created by a
  3616 definition specification element in the context of locale
  3617 partial_order.
  3618 
  3619 * Method "induct": improved internal context management to support
  3620 local fixes and defines on-the-fly. Thus explicit meta-level
  3621 connectives !!  and ==> are rarely required anymore in inductive goals
  3622 (using object-logic connectives for this purpose has been long
  3623 obsolete anyway). Common proof patterns are explained in
  3624 src/HOL/Induct/Common_Patterns.thy, see also
  3625 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3626 examples.
  3627 
  3628 * Method "induct": improved handling of simultaneous goals. Instead of
  3629 introducing object-level conjunction, the statement is now split into
  3630 several conclusions, while the corresponding symbolic cases are nested
  3631 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3632 see src/HOL/Induct/Common_Patterns.thy, for example.
  3633 
  3634 * Method "induct": mutual induction rules are now specified as a list
  3635 of rule sharing the same induction cases. HOL packages usually provide
  3636 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3637 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3638 mutual induction rules differently, i.e. like this:
  3639 
  3640   (induct rule: foo_bar.inducts)
  3641   (induct set: foo bar)
  3642   (induct pred: foo bar)
  3643   (induct type: foo bar)
  3644 
  3645 The ML function ProjectRule.projections turns old-style rules into the
  3646 new format.
  3647 
  3648 * Method "coinduct": dual of induction, see
  3649 src/HOL/Library/Coinductive_List.thy for various examples.
  3650 
  3651 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3652 considered a legacy feature.
  3653 
  3654 * Attribute "symmetric" produces result with standardized schematic
  3655 variables (index 0).  Potential INCOMPATIBILITY.
  3656 
  3657 * Simplifier: by default the simplifier trace only shows top level
  3658 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3659 default. Thus there is less danger of being flooded by the trace. The
  3660 trace indicates where parts have been suppressed.
  3661   
  3662 * Provers/classical: removed obsolete classical version of elim_format
  3663 attribute; classical elim/dest rules are now treated uniformly when
  3664 manipulating the claset.
  3665 
  3666 * Provers/classical: stricter checks to ensure that supplied intro,
  3667 dest and elim rules are well-formed; dest and elim rules must have at
  3668 least one premise.
  3669 
  3670 * Provers/classical: attributes dest/elim/intro take an optional
  3671 weight argument for the rule (just as the Pure versions).  Weights are
  3672 ignored by automated tools, but determine the search order of single
  3673 rule steps.
  3674 
  3675 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3676 where the body does not mention the bound variable.  Note that dummy
  3677 patterns implicitly depend on their context of bounds, which makes
  3678 "{_. _}" match any set comprehension as expected.  Potential
  3679 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3680 constant "_idtdummy" in the binding position.
  3681 
  3682 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3683 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3684 for example "A -> B" => "Pi A (%_. B)".
  3685 
  3686 * Pure: 'class_deps' command visualizes the subclass relation, using
  3687 the graph browser tool.
  3688 
  3689 * Pure: 'print_theory' now suppresses certain internal declarations by
  3690 default; use '!' option for full details.
  3691 
  3692 
  3693 *** HOL ***
  3694 
  3695 * Method "metis" proves goals by applying the Metis general-purpose
  3696 resolution prover (see also http://gilith.com/software/metis/).
  3697 Examples are in the directory MetisExamples.  WARNING: the
  3698 Isabelle/HOL-Metis integration does not yet work properly with
  3699 multi-threading.
  3700   
  3701 * Command 'sledgehammer' invokes external automatic theorem provers as
  3702 background processes.  It generates calls to the "metis" method if
  3703 successful. These can be pasted into the proof.  Users do not have to
  3704 wait for the automatic provers to return.  WARNING: does not really
  3705 work with multi-threading.
  3706 
  3707 * New "auto_quickcheck" feature tests outermost goal statements for
  3708 potential counter-examples.  Controlled by ML references
  3709 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3710 5000 milliseconds).  Fails silently if statements is outside of
  3711 executable fragment, or any other codgenerator problem occurs.
  3712 
  3713 * New constant "undefined" with axiom "undefined x = undefined".
  3714 
  3715 * Added class "HOL.eq", allowing for code generation with polymorphic
  3716 equality.
  3717 
  3718 * Some renaming of class constants due to canonical name prefixing in
  3719 the new 'class' package:
  3720 
  3721     HOL.abs ~> HOL.abs_class.abs
  3722     HOL.divide ~> HOL.divide_class.divide
  3723     0 ~> HOL.zero_class.zero
  3724     1 ~> HOL.one_class.one
  3725     op + ~> HOL.plus_class.plus
  3726     op - ~> HOL.minus_class.minus
  3727     uminus ~> HOL.minus_class.uminus
  3728     op * ~> HOL.times_class.times
  3729     op < ~> HOL.ord_class.less
  3730     op <= > HOL.ord_class.less_eq
  3731     Nat.power ~> Power.power_class.power
  3732     Nat.size ~> Nat.size_class.size
  3733     Numeral.number_of ~> Numeral.number_class.number_of
  3734     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3735     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3736     Orderings.min ~> Orderings.ord_class.min
  3737     Orderings.max ~> Orderings.ord_class.max
  3738     Divides.op div ~> Divides.div_class.div
  3739     Divides.op mod ~> Divides.div_class.mod
  3740     Divides.op dvd ~> Divides.div_class.dvd
  3741 
  3742 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3743 
  3744 a) User-defined constants using any of the names "plus", "minus",
  3745 "times", "less" or "less_eq". The standard syntax translations for
  3746 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3747 names.
  3748 
  3749 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3750 INCOMPATIBILITY: use more specific names.
  3751 
  3752 c) Permutative equations (e.g. "a + b = b + a")
  3753 Since the change of names also changes the order of terms, permutative
  3754 rewrite rules may get applied in a different order. Experience shows
  3755 that this is rarely the case (only two adaptions in the whole Isabelle
  3756 distribution).  INCOMPATIBILITY: rewrite proofs
  3757 
  3758 d) ML code directly refering to constant names
  3759 This in general only affects hand-written proof tactics, simprocs and
  3760 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3761 Consider using @{const_name} antiquotation.
  3762 
  3763 * New class "default" with associated constant "default".
  3764 
  3765 * Function "sgn" is now overloaded and available on int, real, complex
  3766 (and other numeric types), using class "sgn".  Two possible defs of
  3767 sgn are given as equational assumptions in the classes sgn_if and
  3768 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3769 INCOMPATIBILITY.
  3770 
  3771 * Locale "partial_order" now unified with class "order" (cf. theory
  3772 Orderings), added parameter "less".  INCOMPATIBILITY.
  3773 
  3774 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3775 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3776 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3777 
  3778 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3779 changed order of proof goals in instance proofs.
  3780 
  3781 * The transitivity reasoner for partial and linear orders is set up
  3782 for classes "order" and "linorder".  Instances of the reasoner are available
  3783 in all contexts importing or interpreting the corresponding locales.
  3784 Method "order" invokes the reasoner separately; the reasoner
  3785 is also integrated with the Simplifier as a solver.  Diagnostic
  3786 command 'print_orders' shows the available instances of the reasoner
  3787 in the current context.
  3788 
  3789 * Localized monotonicity predicate in theory "Orderings"; integrated
  3790 lemmas max_of_mono and min_of_mono with this predicate.
  3791 INCOMPATIBILITY.
  3792 
  3793 * Formulation of theorem "dense" changed slightly due to integration
  3794 with new class dense_linear_order.
  3795 
  3796 * Uniform lattice theory development in HOL.
  3797 
  3798     constants "meet" and "join" now named "inf" and "sup"
  3799     constant "Meet" now named "Inf"
  3800 
  3801     classes "meet_semilorder" and "join_semilorder" now named
  3802       "lower_semilattice" and "upper_semilattice"
  3803     class "lorder" now named "lattice"
  3804     class "comp_lat" now named "complete_lattice"
  3805 
  3806     Instantiation of lattice classes allows explicit definitions
  3807     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3808 
  3809   INCOMPATIBILITY.  Theorem renames:
  3810 
  3811     meet_left_le            ~> inf_le1
  3812     meet_right_le           ~> inf_le2
  3813     join_left_le            ~> sup_ge1
  3814     join_right_le           ~> sup_ge2
  3815     meet_join_le            ~> inf_sup_ord
  3816     le_meetI                ~> le_infI
  3817     join_leI                ~> le_supI
  3818     le_meet                 ~> le_inf_iff
  3819     le_join                 ~> ge_sup_conv
  3820     meet_idempotent         ~> inf_idem
  3821     join_idempotent         ~> sup_idem
  3822     meet_comm               ~> inf_commute
  3823     join_comm               ~> sup_commute
  3824     meet_leI1               ~> le_infI1
  3825     meet_leI2               ~> le_infI2
  3826     le_joinI1               ~> le_supI1
  3827     le_joinI2               ~> le_supI2
  3828     meet_assoc              ~> inf_assoc
  3829     join_assoc              ~> sup_assoc
  3830     meet_left_comm          ~> inf_left_commute
  3831     meet_left_idempotent    ~> inf_left_idem
  3832     join_left_comm          ~> sup_left_commute
  3833     join_left_idempotent    ~> sup_left_idem
  3834     meet_aci                ~> inf_aci
  3835     join_aci                ~> sup_aci
  3836     le_def_meet             ~> le_iff_inf
  3837     le_def_join             ~> le_iff_sup
  3838     join_absorp2            ~> sup_absorb2
  3839     join_absorp1            ~> sup_absorb1
  3840     meet_absorp1            ~> inf_absorb1
  3841     meet_absorp2            ~> inf_absorb2
  3842     meet_join_absorp        ~> inf_sup_absorb
  3843     join_meet_absorp        ~> sup_inf_absorb
  3844     distrib_join_le         ~> distrib_sup_le
  3845     distrib_meet_le         ~> distrib_inf_le
  3846 
  3847     add_meet_distrib_left   ~> add_inf_distrib_left
  3848     add_join_distrib_left   ~> add_sup_distrib_left
  3849     is_join_neg_meet        ~> is_join_neg_inf
  3850     is_meet_neg_join        ~> is_meet_neg_sup
  3851     add_meet_distrib_right  ~> add_inf_distrib_right
  3852     add_join_distrib_right  ~> add_sup_distrib_right
  3853     add_meet_join_distribs  ~> add_sup_inf_distribs
  3854     join_eq_neg_meet        ~> sup_eq_neg_inf
  3855     meet_eq_neg_join        ~> inf_eq_neg_sup
  3856     add_eq_meet_join        ~> add_eq_inf_sup
  3857     meet_0_imp_0            ~> inf_0_imp_0
  3858     join_0_imp_0            ~> sup_0_imp_0
  3859     meet_0_eq_0             ~> inf_0_eq_0
  3860     join_0_eq_0             ~> sup_0_eq_0
  3861     neg_meet_eq_join        ~> neg_inf_eq_sup
  3862     neg_join_eq_meet        ~> neg_sup_eq_inf
  3863     join_eq_if              ~> sup_eq_if
  3864 
  3865     mono_meet               ~> mono_inf
  3866     mono_join               ~> mono_sup
  3867     meet_bool_eq            ~> inf_bool_eq
  3868     join_bool_eq            ~> sup_bool_eq
  3869     meet_fun_eq             ~> inf_fun_eq
  3870     join_fun_eq             ~> sup_fun_eq
  3871     meet_set_eq             ~> inf_set_eq
  3872     join_set_eq             ~> sup_set_eq
  3873     meet1_iff               ~> inf1_iff
  3874     meet2_iff               ~> inf2_iff
  3875     meet1I                  ~> inf1I
  3876     meet2I                  ~> inf2I
  3877     meet1D1                 ~> inf1D1
  3878     meet2D1                 ~> inf2D1
  3879     meet1D2                 ~> inf1D2
  3880     meet2D2                 ~> inf2D2
  3881     meet1E                  ~> inf1E
  3882     meet2E                  ~> inf2E
  3883     join1_iff               ~> sup1_iff
  3884     join2_iff               ~> sup2_iff
  3885     join1I1                 ~> sup1I1
  3886     join2I1                 ~> sup2I1
  3887     join1I1                 ~> sup1I1
  3888     join2I2                 ~> sup1I2
  3889     join1CI                 ~> sup1CI
  3890     join2CI                 ~> sup2CI
  3891     join1E                  ~> sup1E
  3892     join2E                  ~> sup2E
  3893 
  3894     is_meet_Meet            ~> is_meet_Inf
  3895     Meet_bool_def           ~> Inf_bool_def
  3896     Meet_fun_def            ~> Inf_fun_def
  3897     Meet_greatest           ~> Inf_greatest
  3898     Meet_lower              ~> Inf_lower
  3899     Meet_set_def            ~> Inf_set_def
  3900 
  3901     Sup_def                 ~> Sup_Inf
  3902     Sup_bool_eq             ~> Sup_bool_def
  3903     Sup_fun_eq              ~> Sup_fun_def
  3904     Sup_set_eq              ~> Sup_set_def
  3905 
  3906     listsp_meetI            ~> listsp_infI
  3907     listsp_meet_eq          ~> listsp_inf_eq
  3908 
  3909     meet_min                ~> inf_min
  3910     join_max                ~> sup_max
  3911 
  3912 * Added syntactic class "size"; overloaded constant "size" now has
  3913 type "'a::size ==> bool"
  3914 
  3915 * Internal reorganisation of `size' of datatypes: size theorems
  3916 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3917 simplification rules by default!); theorems "prod.size" now named
  3918 "*.size".
  3919 
  3920 * Class "div" now inherits from class "times" rather than "type".
  3921 INCOMPATIBILITY.
  3922 
  3923 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3924 Linorder etc.  have disappeared; operations defined in terms of
  3925 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3926 
  3927 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3928 
  3929 * HOL-Word: New extensive library and type for generic, fixed size
  3930 machine words, with arithemtic, bit-wise, shifting and rotating
  3931 operations, reflection into int, nat, and bool lists, automation for
  3932 linear arithmetic (by automatic reflection into nat or int), including
  3933 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3934 arithmetic type classes, supporting automatic simplification of
  3935 numerals on all operations.
  3936 
  3937 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3938 
  3939 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3940 
  3941 * Code generator library theories:
  3942   - Code_Integer represents HOL integers by big integer literals in target
  3943     languages.
  3944   - Code_Char represents HOL characters by character literals in target
  3945     languages.
  3946   - Code_Char_chr like Code_Char, but also offers treatment of character
  3947     codes; includes Code_Integer.
  3948   - Executable_Set allows to generate code for finite sets using lists.
  3949   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3950     denominator).
  3951   - Executable_Real implements a subset of real numbers, namly those
  3952     representable by rational numbers.
  3953   - Efficient_Nat implements natural numbers by integers, which in general will
  3954     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3955     includes Code_Integer.
  3956   - Code_Index provides an additional datatype index which is mapped to
  3957     target-language built-in integers.
  3958   - Code_Message provides an additional datatype message_string which is isomorphic to
  3959     strings; messages are mapped to target-language strings.
  3960 
  3961 * New package for inductive predicates
  3962 
  3963   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3964 
  3965     inductive
  3966       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3967       for z_1 :: U_1 and ... and z_n :: U_m
  3968     where
  3969       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3970     | ...
  3971 
  3972   with full support for type-inference, rather than
  3973 
  3974     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3975 
  3976     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3977     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3978 
  3979     inductive "s z_1 ... z_m"
  3980     intros
  3981       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3982       ...
  3983 
  3984   For backward compatibility, there is a wrapper allowing inductive
  3985   sets to be defined with the new package via
  3986 
  3987     inductive_set
  3988       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3989       for z_1 :: U_1 and ... and z_n :: U_m
  3990     where
  3991       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3992     | ...
  3993 
  3994   or
  3995 
  3996     inductive_set
  3997       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3998       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3999       for z_1 :: U_1 and ... and z_n :: U_m
  4000     where
  4001       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4002     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4003     | ...
  4004 
  4005   if the additional syntax "p ..." is required.
  4006 
  4007   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4008   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4009 
  4010   INCOMPATIBILITIES:
  4011 
  4012   - Since declaration and definition of inductive sets or predicates
  4013     is no longer separated, abbreviations involving the newly
  4014     introduced sets or predicates must be specified together with the
  4015     introduction rules after the 'where' keyword (see above), rather
  4016     than before the actual inductive definition.
  4017 
  4018   - The variables in induction and elimination rules are now
  4019     quantified in the order of their occurrence in the introduction
  4020     rules, rather than in alphabetical order. Since this may break
  4021     some proofs, these proofs either have to be repaired, e.g. by
  4022     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4023     statements of the form
  4024 
  4025       case (rule_i a_i_1 ... a_i_{k_i})
  4026 
  4027     or the old order of quantification has to be restored by explicitly adding
  4028     meta-level quantifiers in the introduction rules, i.e.
  4029 
  4030       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4031 
  4032   - The format of the elimination rules is now
  4033 
  4034       p z_1 ... z_m x_1 ... x_n ==>
  4035         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4036         ==> ... ==> P
  4037 
  4038     for predicates and
  4039 
  4040       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4041         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4042         ==> ... ==> P
  4043 
  4044     for sets rather than
  4045 
  4046       x : s z_1 ... z_m ==>
  4047         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4048         ==> ... ==> P
  4049 
  4050     This may require terms in goals to be expanded to n-tuples
  4051     (e.g. using case_tac or simplification with the split_paired_all
  4052     rule) before the above elimination rule is applicable.
  4053 
  4054   - The elimination or case analysis rules for (mutually) inductive
  4055     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4056     list of rules "p_1_..._p_k.elims" is no longer available.
  4057 
  4058 * New package "function"/"fun" for general recursive functions,
  4059 supporting mutual and nested recursion, definitions in local contexts,
  4060 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4061 for small examples, and the separate tutorial on the function
  4062 package. The old recdef "package" is still available as before, but
  4063 users are encouraged to use the new package.
  4064 
  4065 * Method "lexicographic_order" automatically synthesizes termination
  4066 relations as lexicographic combinations of size measures. 
  4067 
  4068 * Case-expressions allow arbitrary constructor-patterns (including
  4069 "_") and take their order into account, like in functional
  4070 programming.  Internally, this is translated into nested
  4071 case-expressions; missing cases are added and mapped to the predefined
  4072 constant "undefined". In complicated cases printing may no longer show
  4073 the original input but the internal form. Lambda-abstractions allow
  4074 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4075 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4076 variable.
  4077 
  4078 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4079 is an abbreviation for "of_nat :: nat => int". The simplification
  4080 rules for "of_nat" have been changed to work like "int" did
  4081 previously.  Potential INCOMPATIBILITY:
  4082   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4083   - of_nat_diff and of_nat_mult are no longer default simp rules
  4084 
  4085 * Method "algebra" solves polynomial equations over (semi)rings using
  4086 Groebner bases. The (semi)ring structure is defined by locales and the
  4087 tool setup depends on that generic context. Installing the method for
  4088 a specific type involves instantiating the locale and possibly adding
  4089 declarations for computation on the coefficients.  The method is
  4090 already instantiated for natural numbers and for the axiomatic class
  4091 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4092 CALCULEMUS 2007 for the general principles underlying this
  4093 architecture of context-aware proof-tools.
  4094 
  4095 * Method "ferrack" implements quantifier elimination over
  4096 special-purpose dense linear orders using locales (analogous to
  4097 "algebra"). The method is already installed for class
  4098 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4099 rat, etc.
  4100 
  4101 * Former constant "List.op @" now named "List.append".  Use ML
  4102 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4103 circumvent possible incompatibilities when working on ML level.
  4104 
  4105 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4106 
  4107 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4108 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4109 
  4110 * New syntax for Haskell-like list comprehension (input only), eg.
  4111 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4112 
  4113 * The special syntax for function "filter" has changed from [x :
  4114 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4115 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4116 
  4117 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4118 defined on nat only, as an abbreviation for [a..<Suc b]
  4119 INCOMPATIBILITY.
  4120 
  4121 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4122 
  4123 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4124 
  4125 * New lemma collection field_simps (an extension of ring_simps) for
  4126 manipulating (in)equations involving division. Multiplies with all
  4127 denominators that can be proved to be non-zero (in equations) or
  4128 positive/negative (in inequations).
  4129 
  4130 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4131 have been improved and renamed to ring_simps, group_simps and
  4132 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4133 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4134 
  4135 * Theory Library/Commutative_Ring: switched from recdef to function
  4136 package; constants add, mul, pow now curried.  Infix syntax for
  4137 algebraic operations.
  4138 
  4139 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4140 INCOMPATIBILITY.
  4141 
  4142 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4143 INCOMPATIBILITY.
  4144 
  4145 * HOL/records: generalised field-update to take a function on the
  4146 field rather than the new value: r(|A := x|) is translated to A_update
  4147 (K x) r The K-combinator that is internally used is called K_record.
  4148 INCOMPATIBILITY: Usage of the plain update functions has to be
  4149 adapted.
  4150  
  4151 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4152 * x = 0, which are required for a semiring.  Richer structures do not
  4153 inherit from semiring_0 anymore, because this property is a theorem
  4154 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4155 there is more to prove, but this is mostly trivial.
  4156 
  4157 * Class "recpower" is generalized to arbitrary monoids, not just
  4158 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4159 commutativity or semiring properties additionally.
  4160 
  4161 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4162 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4163 better use 'abbreviation'.
  4164 
  4165 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4166 
  4167 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4168 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4169 significant changes for setting up numeral syntax for types:
  4170   - New constants Numeral.pred and Numeral.succ instead
  4171       of former Numeral.bin_pred and Numeral.bin_succ.
  4172   - Use integer operations instead of bin_add, bin_mult and so on.
  4173   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4174   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4175 
  4176 See src/HOL/Integ/IntArith.thy for an example setup.
  4177 
  4178 * Command 'normal_form' computes the normal form of a term that may
  4179 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4180 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4181 heavy-duty computations because the functions are compiled to ML
  4182 first.  Correspondingly, a method "normalization" is provided.  See
  4183 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4184 
  4185 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4186 25 like -->); output depends on the "iff" print_mode, the default is
  4187 "A = B" (with priority 50).
  4188 
  4189 * Relations less (<) and less_eq (<=) are also available on type bool.
  4190 Modified syntax to disallow nesting without explicit parentheses,
  4191 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4192 INCOMPATIBILITY.
  4193 
  4194 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4195 
  4196 * Relation composition operator "op O" now has precedence 75 and binds
  4197 stronger than union and intersection. INCOMPATIBILITY.
  4198 
  4199 * The old set interval syntax "{m..n(}" (and relatives) has been
  4200 removed.  Use "{m..<n}" (and relatives) instead.
  4201 
  4202 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4203 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4204 ``declare [[simproc del: neq]]''.
  4205 
  4206 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4207 True/False.
  4208 
  4209 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4210 
  4211 * Theorem setsum_mult renamed to setsum_right_distrib.
  4212 
  4213 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4214 ``rule'' method.
  4215 
  4216 * Reimplemented methods "sat" and "satx", with several improvements:
  4217 goals no longer need to be stated as "<prems> ==> False", equivalences
  4218 (i.e. "=" on type bool) are handled, variable names of the form
  4219 "lit_<n>" are no longer reserved, significant speedup.
  4220 
  4221 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4222 zChaff is still supported as well.
  4223 
  4224 * 'inductive' and 'datatype': provide projections of mutual rules,
  4225 bundled as foo_bar.inducts;
  4226 
  4227 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4228 Library.
  4229 
  4230 * Library: moved theory Accessible_Part to main HOL.
  4231 
  4232 * Library: added theory Coinductive_List of potentially infinite lists
  4233 as greatest fixed-point.
  4234 
  4235 * Library: added theory AssocList which implements (finite) maps as
  4236 association lists.
  4237 
  4238 * Method "evaluation" solves goals (i.e. a boolean expression)
  4239 efficiently by compiling it to ML.  The goal is "proved" (via an
  4240 oracle) if it evaluates to True.
  4241 
  4242 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4243 also when invoked by the simplifier.  This results in the Simplifier
  4244 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4245 Configuration option fast_arith_split_limit=0 recovers the old
  4246 behavior.
  4247 
  4248 * Support for hex (0x20) and binary (0b1001) numerals.
  4249 
  4250 * New method: reify eqs (t), where eqs are equations for an
  4251 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4252 parameter, computes a term s::'b and a list xs::'a list and proves the
  4253 theorem I xs s = t. This is also known as reification or quoting. The
  4254 resulting theorem is applied to the subgoal to substitute t with I xs
  4255 s.  If t is omitted, the subgoal itself is reified.
  4256 
  4257 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4258 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4259 where f is supposed to be a computable function (in the sense of code
  4260 generattion). The method uses reify to compute s and xs as above then
  4261 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4262 r and finally gets the theorem t = r, which is again applied to the
  4263 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4264 
  4265 * Reflection: Automatic reification now handels binding, an example is
  4266 available in src/HOL/ex/ReflectionEx.thy
  4267 
  4268 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4269 command 'statespace' that is similar to 'record', but introduces an
  4270 abstract specification based on the locale infrastructure instead of
  4271 HOL types.  This leads to extra flexibility in composing state spaces,
  4272 in particular multiple inheritance and renaming of components.
  4273 
  4274 
  4275 *** HOL-Complex ***
  4276 
  4277 * Hyperreal: Functions root and sqrt are now defined on negative real
  4278 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4279 Nonnegativity side conditions have been removed from many lemmas, so
  4280 that more subgoals may now be solved by simplification; potential
  4281 INCOMPATIBILITY.
  4282 
  4283 * Real: new type classes formalize real normed vector spaces and
  4284 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4285 and norm :: 'a => real.
  4286 
  4287 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4288 reals into other types. The overloaded constant Reals :: 'a set is now
  4289 defined as range of_real; potential INCOMPATIBILITY.
  4290 
  4291 * Real: proper support for ML code generation, including 'quickcheck'.
  4292 Reals are implemented as arbitrary precision rationals.
  4293 
  4294 * Hyperreal: Several constants that previously worked only for the
  4295 reals have been generalized, so they now work over arbitrary vector
  4296 spaces. Type annotations may need to be added in some cases; potential
  4297 INCOMPATIBILITY.
  4298 
  4299   Infinitesimal  :: ('a::real_normed_vector) star set
  4300   HFinite        :: ('a::real_normed_vector) star set
  4301   HInfinite      :: ('a::real_normed_vector) star set
  4302   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4303   monad          :: ('a::real_normed_vector) star => 'a star set
  4304   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4305   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4306   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4307   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4308   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4309   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4310   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4311   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4312   sgn            :: 'a::real_normed_vector => 'a
  4313   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4314 
  4315 * Complex: Some complex-specific constants are now abbreviations for
  4316 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4317 hnorm.  Other constants have been entirely removed in favor of the
  4318 polymorphic versions (INCOMPATIBILITY):
  4319 
  4320   approx        <-- capprox
  4321   HFinite       <-- CFinite
  4322   HInfinite     <-- CInfinite
  4323   Infinitesimal <-- CInfinitesimal
  4324   monad         <-- cmonad
  4325   galaxy        <-- cgalaxy
  4326   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4327   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4328   (ns)deriv     <-- (ns)cderiv
  4329 
  4330 
  4331 *** HOL-Algebra ***
  4332 
  4333 * Formalisation of ideals and the quotient construction over rings.
  4334 
  4335 * Order and lattice theory no longer based on records.
  4336 INCOMPATIBILITY.
  4337 
  4338 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4339 greatest_closed.  INCOMPATIBILITY.
  4340 
  4341 * Method algebra is now set up via an attribute.  For examples see
  4342 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4343 of algebraic structures.
  4344 
  4345 * Renamed theory CRing to Ring.
  4346 
  4347 
  4348 *** HOL-Nominal ***
  4349 
  4350 * Substantial, yet incomplete support for nominal datatypes (binding
  4351 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4352 src/HOL/Nominal/Examples.  Prospective users should consult
  4353 http://isabelle.in.tum.de/nominal/
  4354 
  4355 
  4356 *** ML ***
  4357 
  4358 * ML basics: just one true type int, which coincides with IntInf.int
  4359 (even on SML/NJ).
  4360 
  4361 * ML within Isar: antiquotations allow to embed statically-checked
  4362 formal entities in the source, referring to the context available at
  4363 compile-time.  For example:
  4364 
  4365 ML {* @{sort "{zero,one}"} *}
  4366 ML {* @{typ "'a => 'b"} *}
  4367 ML {* @{term "%x. x"} *}
  4368 ML {* @{prop "x == y"} *}
  4369 ML {* @{ctyp "'a => 'b"} *}
  4370 ML {* @{cterm "%x. x"} *}
  4371 ML {* @{cprop "x == y"} *}
  4372 ML {* @{thm asm_rl} *}
  4373 ML {* @{thms asm_rl} *}
  4374 ML {* @{type_name c} *}
  4375 ML {* @{type_syntax c} *}
  4376 ML {* @{const_name c} *}
  4377 ML {* @{const_syntax c} *}
  4378 ML {* @{context} *}
  4379 ML {* @{theory} *}
  4380 ML {* @{theory Pure} *}
  4381 ML {* @{theory_ref} *}
  4382 ML {* @{theory_ref Pure} *}
  4383 ML {* @{simpset} *}
  4384 ML {* @{claset} *}
  4385 ML {* @{clasimpset} *}
  4386 
  4387 The same works for sources being ``used'' within an Isar context.
  4388 
  4389 * ML in Isar: improved error reporting; extra verbosity with
  4390 ML_Context.trace enabled.
  4391 
  4392 * Pure/General/table.ML: the join operations now works via exceptions
  4393 DUP/SAME instead of type option. This is simpler in simple cases, and
  4394 admits slightly more efficient complex applications.
  4395 
  4396 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4397 use Context.generic instead of just theory.
  4398 
  4399 * Pure: datatype Context.generic joins theory/Proof.context and
  4400 provides some facilities for code that works in either kind of
  4401 context, notably GenericDataFun for uniform theory and proof data.
  4402 
  4403 * Pure: simplified internal attribute type, which is now always
  4404 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4405 local (Proof.context) attributes have been discontinued, while
  4406 minimizing code duplication. Thm.rule_attribute and
  4407 Thm.declaration_attribute build canonical attributes; see also structure
  4408 Context for further operations on Context.generic, notably
  4409 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4410 declarations and definitions.
  4411 
  4412 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4413 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4414 init only required for impure data. INCOMPATIBILITY: empty really need
  4415 to be empty (no dependencies on theory content!)
  4416 
  4417 * Pure/kernel: consts certification ignores sort constraints given in
  4418 signature declarations. (This information is not relevant to the
  4419 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4420 potential INCOMPATIBILITY.
  4421 
  4422 * Pure: axiomatic type classes are now purely definitional, with
  4423 explicit proofs of class axioms and super class relations performed
  4424 internally. See Pure/axclass.ML for the main internal interfaces --
  4425 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4426 AxClass.axiomatize_class/classrel/arity supersede
  4427 Sign.add_classes/classrel/arities.
  4428 
  4429 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4430 global/local versions on theory vs. Proof.context have been
  4431 discontinued; Attrib.syntax and Method.syntax have been adapted
  4432 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4433 attributes, methods, etc.
  4434 
  4435 * Pure: several functions of signature "... -> theory -> theory * ..."
  4436 have been reoriented to "... -> theory -> ... * theory" in order to
  4437 allow natural usage in combination with the ||>, ||>>, |-> and
  4438 fold_map combinators.
  4439 
  4440 * Pure: official theorem names (closed derivations) and additional
  4441 comments (tags) are now strictly separate.  Name hints -- which are
  4442 maintained as tags -- may be attached any time without affecting the
  4443 derivation.
  4444 
  4445 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4446 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4447 achieve the old behaviour.
  4448 
  4449 * Pure: the "Goal" constant is now called "prop", supporting a
  4450 slightly more general idea of ``protecting'' meta-level rule
  4451 statements.
  4452 
  4453 * Pure: Logic.(un)varify only works in a global context, which is now
  4454 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4455 Logic.legacy_(un)varify as temporary workaround.
  4456 
  4457 * Pure: structure Name provides scalable operations for generating
  4458 internal variable names, notably Name.variants etc.  This replaces
  4459 some popular functions from term.ML:
  4460 
  4461   Term.variant		->  Name.variant
  4462   Term.variantlist	->  Name.variant_list
  4463   Term.invent_names	->  Name.invent_list
  4464 
  4465 Note that low-level renaming rarely occurs in new code -- operations
  4466 from structure Variable are used instead (see below).
  4467 
  4468 * Pure: structure Variable provides fundamental operations for proper
  4469 treatment of fixed/schematic variables in a context.  For example,
  4470 Variable.import introduces fixes for schematics of given facts and
  4471 Variable.export reverses the effect (up to renaming) -- this replaces
  4472 various freeze_thaw operations.
  4473 
  4474 * Pure: structure Goal provides simple interfaces for
  4475 init/conclude/finish and tactical prove operations (replacing former
  4476 Tactic.prove).  Goal.prove is the canonical way to prove results
  4477 within a given context; Goal.prove_global is a degraded version for
  4478 theory level goals, including a global Drule.standard.  Note that
  4479 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4480 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4481 in a locale context).
  4482 
  4483 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4484 and type checking (Syntax.check_term etc.), with common combinations
  4485 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4486 which are considered legacy and await removal.
  4487 
  4488 * Pure/Syntax: generic interfaces for type unchecking
  4489 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4490 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4491 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4492 available for convenience, but refer to the very same operations using
  4493 a mere theory instead of a full context.
  4494 
  4495 * Isar: simplified treatment of user-level errors, using exception
  4496 ERROR of string uniformly.  Function error now merely raises ERROR,
  4497 without any side effect on output channels.  The Isar toplevel takes
  4498 care of proper display of ERROR exceptions.  ML code may use plain
  4499 handle/can/try; cat_error may be used to concatenate errors like this:
  4500 
  4501   ... handle ERROR msg => cat_error msg "..."
  4502 
  4503 Toplevel ML code (run directly or through the Isar toplevel) may be
  4504 embedded into the Isar toplevel with exception display/debug like
  4505 this:
  4506 
  4507   Isar.toplevel (fn () => ...)
  4508 
  4509 INCOMPATIBILITY, removed special transform_error facilities, removed
  4510 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4511 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4512 -- use plain ERROR instead.
  4513 
  4514 * Isar: theory setup now has type (theory -> theory), instead of a
  4515 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4516 
  4517 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4518 ProofContext.debug/verbose flags.
  4519 
  4520 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4521 theory before entering a proof state.  Transactions now always see a
  4522 quasi-functional intermediate checkpoint, both in interactive and
  4523 batch mode.
  4524 
  4525 * Isar: simplified interfaces for outer syntax.  Renamed
  4526 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4527 OuterSyntax.add_parsers -- this functionality is now included in
  4528 OuterSyntax.command etc.  INCOMPATIBILITY.
  4529 
  4530 * Simplifier: the simpset of a running simplification process now
  4531 contains a proof context (cf. Simplifier.the_context), which is the
  4532 very context that the initial simpset has been retrieved from (by
  4533 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4534 (solver, looper etc.) may depend on arbitrary proof data.
  4535 
  4536 * Simplifier.inherit_context inherits the proof context (plus the
  4537 local bounds) of the current simplification process; any simproc
  4538 etc. that calls the Simplifier recursively should do this!  Removed
  4539 former Simplifier.inherit_bounds, which is already included here --
  4540 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4541 specify an explicit context using Simplifier.context/theory_context.
  4542 
  4543 * Simplifier/Classical Reasoner: more abstract interfaces
  4544 change_simpset/claset for modifying the simpset/claset reference of a
  4545 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4546 INCOMPATIBILITY.
  4547 
  4548 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4549 "Trueprop" etc.
  4550 
  4551 
  4552 *** System ***
  4553 
  4554 * settings: the default heap location within ISABELLE_HOME_USER now
  4555 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4556 Isabelle installations.
  4557 
  4558 * isabelle-process: option -S (secure mode) disables some critical
  4559 operations, notably runtime compilation and evaluation of ML source
  4560 code.
  4561 
  4562 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4563 
  4564 * Support for parallel execution, using native multicore support of
  4565 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4566 independent theories, according to the given theory header
  4567 specifications. The maximum number of worker threads is specified via
  4568 usedir option -M or the "max-threads" setting in Proof General. A
  4569 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4570 to 6 on a 8-core machine.  User-code needs to observe certain
  4571 guidelines for thread-safe programming, see appendix A in the Isar
  4572 Implementation manual.
  4573 
  4574 
  4575 
  4576 New in Isabelle2005 (October 2005)
  4577 ----------------------------------
  4578 
  4579 *** General ***
  4580 
  4581 * Theory headers: the new header syntax for Isar theories is
  4582 
  4583   theory <name>
  4584   imports <theory1> ... <theoryN>
  4585   uses <file1> ... <fileM>
  4586   begin
  4587 
  4588 where the 'uses' part is optional.  The previous syntax
  4589 
  4590   theory <name> = <theory1> + ... + <theoryN>:
  4591 
  4592 will disappear in the next release.  Use isatool fixheaders to convert
  4593 existing theory files.  Note that there is no change in ancient
  4594 non-Isar theories now, but these will disappear soon.
  4595 
  4596 * Theory loader: parent theories can now also be referred to via
  4597 relative and absolute paths.
  4598 
  4599 * Command 'find_theorems' searches for a list of criteria instead of a
  4600 list of constants. Known criteria are: intro, elim, dest, name:string,
  4601 simp:term, and any term. Criteria can be preceded by '-' to select
  4602 theorems that do not match. Intro, elim, dest select theorems that
  4603 match the current goal, name:s selects theorems whose fully qualified
  4604 name contain s, and simp:term selects all simplification rules whose
  4605 lhs match term.  Any other term is interpreted as pattern and selects
  4606 all theorems matching the pattern. Available in ProofGeneral under
  4607 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4608 
  4609   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4610 
  4611 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4612 matching the current goal as introduction rule and not having "HOL."
  4613 in their name (i.e. not being defined in theory HOL).
  4614 
  4615 * Command 'thms_containing' has been discontinued in favour of
  4616 'find_theorems'; INCOMPATIBILITY.
  4617 
  4618 * Communication with Proof General is now 8bit clean, which means that
  4619 Unicode text in UTF-8 encoding may be used within theory texts (both
  4620 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4621 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4622 
  4623   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4624   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4625 
  4626 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4627 Classical Reasoner.  Typical big applications run around 2 times
  4628 faster.
  4629 
  4630 
  4631 *** Document preparation ***
  4632 
  4633 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4634 of raw sources.  Only those symbols that do not require additional
  4635 LaTeX packages (depending on comments in isabellesym.sty) are
  4636 displayed properly, everything else is left verbatim.  isatool display
  4637 and isatool print are used as front ends (these are subject to the
  4638 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4639 
  4640 * Command tags control specific markup of certain regions of text,
  4641 notably folding and hiding.  Predefined tags include "theory" (for
  4642 theory begin and end), "proof" for proof commands, and "ML" for
  4643 commands involving ML code; the additional tags "visible" and
  4644 "invisible" are unused by default.  Users may give explicit tag
  4645 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4646 interpretation of tags is determined by the LaTeX job during document
  4647 preparation: see option -V of isatool usedir, or options -n and -t of
  4648 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4649 \isadroptag.
  4650 
  4651 Several document versions may be produced at the same time via isatool
  4652 usedir (the generated index.html will link all of them).  Typical
  4653 specifications include ''-V document=theory,proof,ML'' to present
  4654 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4655 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4656 these parts without any formal replacement text.  The Isabelle site
  4657 default settings produce ''document'' and ''outline'' versions as
  4658 specified above.
  4659 
  4660 * Several new antiquotations:
  4661 
  4662   @{term_type term} prints a term with its type annotated;
  4663 
  4664   @{typeof term} prints the type of a term;
  4665 
  4666   @{const const} is the same as @{term const}, but checks that the
  4667   argument is a known logical constant;
  4668 
  4669   @{term_style style term} and @{thm_style style thm} print a term or
  4670   theorem applying a "style" to it
  4671 
  4672   @{ML text}
  4673 
  4674 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4675 definitions, equations, inequations etc., 'concl' printing only the
  4676 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4677 to print the specified premise.  TermStyle.add_style provides an ML
  4678 interface for introducing further styles.  See also the "LaTeX Sugar"
  4679 document practical applications.  The ML antiquotation prints
  4680 type-checked ML expressions verbatim.
  4681 
  4682 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4683 and 'text' support optional locale specification '(in loc)', which
  4684 specifies the default context for interpreting antiquotations.  For
  4685 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4686 
  4687 * Option 'locale=NAME' of antiquotations specifies an alternative
  4688 context interpreting the subsequent argument.  For example: @{thm
  4689 [locale=lattice] inf_assoc}.
  4690 
  4691 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4692 a proof context.
  4693 
  4694 * Proper output of antiquotations for theory commands involving a
  4695 proof context (such as 'locale' or 'theorem (in loc) ...').
  4696 
  4697 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4698 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4699 
  4700 * isatool usedir: new option -C (default true) controls whether option
  4701 -D should include a copy of the original document directory; -C false
  4702 prevents unwanted effects such as copying of administrative CVS data.
  4703 
  4704 
  4705 *** Pure ***
  4706 
  4707 * Considerably improved version of 'constdefs' command.  Now performs
  4708 automatic type-inference of declared constants; additional support for
  4709 local structure declarations (cf. locales and HOL records), see also
  4710 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4711 sequential dependencies of definitions within a single 'constdefs'
  4712 section; moreover, the declared name needs to be an identifier.  If
  4713 all fails, consider to fall back on 'consts' and 'defs' separately.
  4714 
  4715 * Improved indexed syntax and implicit structures.  First of all,
  4716 indexed syntax provides a notational device for subscripted
  4717 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4718 expressions.  Secondly, in a local context with structure
  4719 declarations, number indexes \<^sub>n or the empty index (default
  4720 number 1) refer to a certain fixed variable implicitly; option
  4721 show_structs controls printing of implicit structures.  Typical
  4722 applications of these concepts involve record types and locales.
  4723 
  4724 * New command 'no_syntax' removes grammar declarations (and
  4725 translations) resulting from the given syntax specification, which is
  4726 interpreted in the same manner as for the 'syntax' command.
  4727 
  4728 * 'Advanced' translation functions (parse_translation etc.) may depend
  4729 on the signature of the theory context being presently used for
  4730 parsing/printing, see also isar-ref manual.
  4731 
  4732 * Improved 'oracle' command provides a type-safe interface to turn an
  4733 ML expression of type theory -> T -> term into a primitive rule of
  4734 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4735 is already included here); see also FOL/ex/IffExample.thy;
  4736 INCOMPATIBILITY.
  4737 
  4738 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4739 before); "cI" is no longer bound, use "c.intro" instead.
  4740 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4741 axclasses vs. locales.
  4742 
  4743 * Improved internal renaming of symbolic identifiers -- attach primes
  4744 instead of base 26 numbers.
  4745 
  4746 * New flag show_question_marks controls printing of leading question
  4747 marks in schematic variable names.
  4748 
  4749 * In schematic variable names, *any* symbol following \<^isub> or
  4750 \<^isup> is now treated as part of the base name.  For example, the
  4751 following works without printing of awkward ".0" indexes:
  4752 
  4753   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4754     by simp
  4755 
  4756 * Inner syntax includes (*(*nested*) comments*).
  4757 
  4758 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4759 annotations as "(00...)".
  4760 
  4761 * Clear separation of logical types and nonterminals, where the latter
  4762 may only occur in 'syntax' specifications or type abbreviations.
  4763 Before that distinction was only partially implemented via type class
  4764 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4765 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4766 exotic syntax specifications may require further adaption
  4767 (e.g. Cube/Cube.thy).
  4768 
  4769 * Removed obsolete type class "logic", use the top sort {} instead.
  4770 Note that non-logical types should be declared as 'nonterminals'
  4771 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4772 specifications.
  4773 
  4774 * Attributes 'induct' and 'cases': type or set names may now be
  4775 locally fixed variables as well.
  4776 
  4777 * Simplifier: can now control the depth to which conditional rewriting
  4778 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4779 Limit.
  4780 
  4781 * Simplifier: simplification procedures may now take the current
  4782 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4783 interface), which is very useful for calling the Simplifier
  4784 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4785 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4786 low-level mk_simproc no longer applies Logic.varify internally, to
  4787 allow for use in a context of fixed variables.
  4788 
  4789 * thin_tac now works even if the assumption being deleted contains !!
  4790 or ==>.  More generally, erule now works even if the major premise of
  4791 the elimination rule contains !! or ==>.
  4792 
  4793 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4794 
  4795 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4796 from Pure, which contains all common declarations already.  Both
  4797 theories are defined via plain Isabelle/Isar .thy files.
  4798 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4799 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4800 use isatool fixcpure to adapt your theory and ML sources.
  4801 
  4802 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4803 selections of theorems in named facts via index ranges.
  4804 
  4805 * 'print_theorems': in theory mode, really print the difference
  4806 wrt. the last state (works for interactive theory development only),
  4807 in proof mode print all local facts (cf. 'print_facts');
  4808 
  4809 * 'hide': option '(open)' hides only base names.
  4810 
  4811 * More efficient treatment of intermediate checkpoints in interactive
  4812 theory development.
  4813 
  4814 * Code generator is now invoked via code_module (incremental code
  4815 generation) and code_library (modular code generation, ML structures
  4816 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4817 must be quoted when used as identifiers.
  4818 
  4819 * New 'value' command for reading, evaluating and printing terms using
  4820 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4821 quoted when used as identifier.
  4822 
  4823 
  4824 *** Locales ***
  4825 
  4826 * New commands for the interpretation of locale expressions in
  4827 theories (1), locales (2) and proof contexts (3).  These generate
  4828 proof obligations from the expression specification.  After the
  4829 obligations have been discharged, theorems of the expression are added
  4830 to the theory, target locale or proof context.  The synopsis of the
  4831 commands is a follows:
  4832 
  4833   (1) interpretation expr inst
  4834   (2) interpretation target < expr
  4835   (3) interpret expr inst
  4836 
  4837 Interpretation in theories and proof contexts require a parameter
  4838 instantiation of terms from the current context.  This is applied to
  4839 specifications and theorems of the interpreted expression.
  4840 Interpretation in locales only permits parameter renaming through the
  4841 locale expression.  Interpretation is smart in that interpretations
  4842 that are active already do not occur in proof obligations, neither are
  4843 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4844 inspect active interpretations of a particular locale.  For details,
  4845 see the Isar Reference manual.  Examples can be found in
  4846 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4847 
  4848 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4849 'interpret' instead.
  4850 
  4851 * New context element 'constrains' for adding type constraints to
  4852 parameters.
  4853 
  4854 * Context expressions: renaming of parameters with syntax
  4855 redeclaration.
  4856 
  4857 * Locale declaration: 'includes' disallowed.
  4858 
  4859 * Proper static binding of attribute syntax -- i.e. types / terms /
  4860 facts mentioned as arguments are always those of the locale definition
  4861 context, independently of the context of later invocations.  Moreover,
  4862 locale operations (renaming and type / term instantiation) are applied
  4863 to attribute arguments as expected.
  4864 
  4865 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4866 actual attributes; rare situations may require Attrib.attribute to
  4867 embed those attributes into Attrib.src that lack concrete syntax.
  4868 Attribute implementations need to cooperate properly with the static
  4869 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4870 Attrib.XXX_thm etc. already do the right thing without further
  4871 intervention.  Only unusual applications -- such as "where" or "of"
  4872 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4873 on the context and the facts involved -- may have to assign parsed
  4874 values to argument tokens explicitly.
  4875 
  4876 * Changed parameter management in theorem generation for long goal
  4877 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4878 theorem statement in rare situations.
  4879 
  4880 * Locale inspection command 'print_locale' omits notes elements.  Use
  4881 'print_locale!' to have them included in the output.
  4882 
  4883 
  4884 *** Provers ***
  4885 
  4886 * Provers/hypsubst.ML: improved version of the subst method, for
  4887 single-step rewriting: it now works in bound variable contexts. New is
  4888 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4889 rewrite a different subterm than the original subst method, which is
  4890 still available as 'simplesubst'.
  4891 
  4892 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4893 and quasi orders.
  4894 
  4895 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4896 reflexive-transitive closure of relations.
  4897 
  4898 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4899 limit (previously hard-coded with a value of 20) user-definable.
  4900 
  4901 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4902 is peformed already.  Object-logics merely need to finish their
  4903 initial simpset configuration as before.  INCOMPATIBILITY.
  4904 
  4905 
  4906 *** HOL ***
  4907 
  4908 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4909 
  4910   syntax (epsilon)
  4911     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4912 
  4913 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4914 and x-symbol; use option '-m epsilon' to get it actually printed.
  4915 Moreover, the mathematically important symbolic identifier \<epsilon>
  4916 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4917 
  4918 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4919 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4920 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4921 support corresponding Isar calculations.
  4922 
  4923 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4924 instead of ":".
  4925 
  4926 * theory SetInterval: changed the syntax for open intervals:
  4927 
  4928   Old       New
  4929   {..n(}    {..<n}
  4930   {)n..}    {n<..}
  4931   {m..n(}   {m..<n}
  4932   {)m..n}   {m<..n}
  4933   {)m..n(}  {m<..<n}
  4934 
  4935 The old syntax is still supported but will disappear in the next
  4936 release.  For conversion use the following Emacs search and replace
  4937 patterns (these are not perfect but work quite well):
  4938 
  4939   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4940   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4941 
  4942 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4943 equalities in commutative rings; method 'algebra' provides a generic
  4944 interface.
  4945 
  4946 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4947 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4948 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4949 be a tuple pattern.
  4950 
  4951 Some new syntax forms are available:
  4952 
  4953   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4954   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4955   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4956   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4957 
  4958 The latter form "\<Sum>x < k. e" used to be based on a separate
  4959 function "Summation", which has been discontinued.
  4960 
  4961 * theory Finite_Set: in structured induction proofs, the insert case
  4962 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4963 (insert F x)'.
  4964 
  4965 * The 'refute' command has been extended to support a much larger
  4966 fragment of HOL, including axiomatic type classes, constdefs and
  4967 typedefs, inductive datatypes and recursion.
  4968 
  4969 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4970 Requires zChaff with proof generation to be installed.  See
  4971 HOL/ex/SAT_Examples.thy for examples.
  4972 
  4973 * Datatype induction via method 'induct' now preserves the name of the
  4974 induction variable. For example, when proving P(xs::'a list) by
  4975 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4976 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4977 in unstructured proof scripts.
  4978 
  4979 * Reworked implementation of records.  Improved scalability for
  4980 records with many fields, avoiding performance problems for type
  4981 inference. Records are no longer composed of nested field types, but
  4982 of nested extension types. Therefore the record type only grows linear
  4983 in the number of extensions and not in the number of fields.  The
  4984 top-level (users) view on records is preserved.  Potential
  4985 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4986 old record representation. The type generated for a record is called
  4987 <record_name>_ext_type.
  4988 
  4989 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4990 proofs triggered by a record definition or a simproc (if
  4991 quick_and_dirty is enabled).  Definitions of large records can take
  4992 quite long.
  4993 
  4994 New simproc record_upd_simproc for simplification of multiple record
  4995 updates enabled by default.  Moreover, trivial updates are also
  4996 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4997 occasionally, since simplification is more powerful by default.
  4998 
  4999 * typedef: proper support for polymorphic sets, which contain extra
  5000 type-variables in the term.
  5001 
  5002 * Simplifier: automatically reasons about transitivity chains
  5003 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5004 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5005 old proofs break occasionally as simplification may now solve more
  5006 goals than previously.
  5007 
  5008 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5009 present.  Works for all partial orders (class "order"), in particular
  5010 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5011 just like y <= x.
  5012 
  5013 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5014 bound variable or a constant then the let is unfolded.  Otherwise
  5015 first a is simplified to b, and then f b is simplified to g. If
  5016 possible we abstract b from g arriving at "let x = b in h x",
  5017 otherwise we unfold the let and arrive at g.  The simproc can be
  5018 enabled/disabled by the reference use_let_simproc.  Potential
  5019 INCOMPATIBILITY since simplification is more powerful by default.
  5020 
  5021 * Classical reasoning: the meson method now accepts theorems as arguments.
  5022 
  5023 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5024 jobs to provide advice on the provability of subgoals.
  5025 
  5026 * Theory OrderedGroup and Ring_and_Field: various additions and
  5027 improvements to faciliate calculations involving equalities and
  5028 inequalities.
  5029 
  5030 The following theorems have been eliminated or modified
  5031 (INCOMPATIBILITY):
  5032 
  5033   abs_eq             now named abs_of_nonneg
  5034   abs_of_ge_0        now named abs_of_nonneg
  5035   abs_minus_eq       now named abs_of_nonpos
  5036   imp_abs_id         now named abs_of_nonneg
  5037   imp_abs_neg_id     now named abs_of_nonpos
  5038   mult_pos           now named mult_pos_pos
  5039   mult_pos_le        now named mult_nonneg_nonneg
  5040   mult_pos_neg_le    now named mult_nonneg_nonpos
  5041   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5042   mult_neg           now named mult_neg_neg
  5043   mult_neg_le        now named mult_nonpos_nonpos
  5044 
  5045 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5046      
  5047      zero_le_square
  5048      not_square_less_zero 
  5049 
  5050   The following lemmas have been deleted from Real/RealPow:
  5051   
  5052      realpow_zero_zero
  5053      realpow_two
  5054      realpow_less
  5055      zero_le_power
  5056      realpow_two_le
  5057      abs_realpow_two
  5058      realpow_two_abs     
  5059 
  5060 * Theory Parity: added rules for simplifying exponents.
  5061 
  5062 * Theory List:
  5063 
  5064 The following theorems have been eliminated or modified
  5065 (INCOMPATIBILITY):
  5066 
  5067   list_all_Nil       now named list_all.simps(1)
  5068   list_all_Cons      now named list_all.simps(2)
  5069   list_all_conv      now named list_all_iff
  5070   set_mem_eq         now named mem_iff
  5071 
  5072 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5073 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5074 
  5075 
  5076 *** HOL-Complex ***
  5077 
  5078 * Theory RealDef: better support for embedding natural numbers and
  5079 integers in the reals.
  5080 
  5081 The following theorems have been eliminated or modified
  5082 (INCOMPATIBILITY):
  5083 
  5084   exp_ge_add_one_self  now requires no hypotheses
  5085   real_of_int_add      reversed direction of equality (use [symmetric])
  5086   real_of_int_minus    reversed direction of equality (use [symmetric])
  5087   real_of_int_diff     reversed direction of equality (use [symmetric])
  5088   real_of_int_mult     reversed direction of equality (use [symmetric])
  5089 
  5090 * Theory RComplete: expanded support for floor and ceiling functions.
  5091 
  5092 * Theory Ln is new, with properties of the natural logarithm
  5093 
  5094 * Hyperreal: There is a new type constructor "star" for making
  5095 nonstandard types.  The old type names are now type synonyms:
  5096 
  5097   hypreal = real star
  5098   hypnat = nat star
  5099   hcomplex = complex star
  5100 
  5101 * Hyperreal: Many groups of similarly-defined constants have been
  5102 replaced by polymorphic versions (INCOMPATIBILITY):
  5103 
  5104   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5105 
  5106   starset      <-- starsetNat, starsetC
  5107   *s*          <-- *sNat*, *sc*
  5108   starset_n    <-- starsetNat_n, starsetC_n
  5109   *sn*         <-- *sNatn*, *scn*
  5110   InternalSets <-- InternalNatSets, InternalCSets
  5111 
  5112   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5113   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5114   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5115   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5116   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5117 
  5118 * Hyperreal: Many type-specific theorems have been removed in favor of
  5119 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5120 
  5121   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5122   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5123   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5124   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5125   right_minus <-- hypreal_add_minus
  5126   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5127   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5128   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5129   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5130   mult_1_right <-- hcomplex_mult_one_right
  5131   mult_zero_left <-- hcomplex_mult_zero_left
  5132   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5133   right_distrib <-- hypnat_add_mult_distrib2
  5134   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5135   right_inverse <-- hypreal_mult_inverse
  5136   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5137   order_refl <-- {hypreal,hypnat}_le_refl
  5138   order_trans <-- {hypreal,hypnat}_le_trans
  5139   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5140   order_less_le <-- {hypreal,hypnat}_less_le
  5141   linorder_linear <-- {hypreal,hypnat}_le_linear
  5142   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5143   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5144   add_nonneg_nonneg <-- hypreal_le_add_order
  5145 
  5146 * Hyperreal: Separate theorems having to do with type-specific
  5147 versions of constants have been merged into theorems that apply to the
  5148 new polymorphic constants (INCOMPATIBILITY):
  5149 
  5150   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5151   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5152   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5153   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5154   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5155   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5156   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5157   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5158   STAR_diff <-- {STAR,STARC}_diff
  5159   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5160     STARC_hcomplex_of_complex}_image_subset
  5161   starset_n_Un <-- starset{Nat,C}_n_Un
  5162   starset_n_Int <-- starset{Nat,C}_n_Int
  5163   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5164   starset_n_diff <-- starset{Nat,C}_n_diff
  5165   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5166   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5167   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5168   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5169   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5170   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5171   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5172   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5173   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5174   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5175   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5176   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5177   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5178   starfun_diff <-- starfun{C,RC,CR}_diff
  5179   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5180   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5181   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5182   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5183   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5184   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5185   starfun_Id <-- starfunC_Id
  5186   starfun_approx <-- starfun{Nat,CR}_approx
  5187   starfun_capprox <-- starfun{C,RC}_capprox
  5188   starfun_abs <-- starfunNat_rabs
  5189   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5190   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5191   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5192   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5193   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5194   starfun_add_approx <-- starfunCR_add_approx
  5195   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5196   starfun_divide <-- starfun{C,CR,RC}_divide
  5197   starfun_n <-- starfun{Nat,C}_n
  5198   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5199   starfun_n_add <-- starfun{Nat,C}_n_add
  5200   starfun_n_add_minus <-- starfunNat_n_add_minus
  5201   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5202   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5203   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5204 
  5205   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5206   star_n_minus <-- {hypreal,hcomplex}_minus
  5207   star_n_diff <-- {hypreal,hcomplex}_diff
  5208   star_n_mult <-- {hypreal,hcomplex}_mult
  5209   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5210   star_n_le <-- {hypreal,hypnat}_le
  5211   star_n_less <-- {hypreal,hypnat}_less
  5212   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5213   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5214   star_n_abs <-- hypreal_hrabs
  5215   star_n_divide <-- hcomplex_divide
  5216 
  5217   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5218   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5219   star_of_diff <-- hypreal_of_real_diff
  5220   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5221   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5222   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5223   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5224   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5225   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5226   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5227   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5228   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5229   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5230   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5231   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5232   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5233   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5234   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5235   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5236   star_of_power <-- hypreal_of_real_power
  5237   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5238 
  5239 * Hyperreal: new method "transfer" that implements the transfer
  5240 principle of nonstandard analysis. With a subgoal that mentions
  5241 nonstandard types like "'a star", the command "apply transfer"
  5242 replaces it with an equivalent one that mentions only standard types.
  5243 To be successful, all free variables must have standard types; non-
  5244 standard variables must have explicit universal quantifiers.
  5245 
  5246 * Hyperreal: A theory of Taylor series.
  5247 
  5248 
  5249 *** HOLCF ***
  5250 
  5251 * Discontinued special version of 'constdefs' (which used to support
  5252 continuous functions) in favor of the general Pure one with full
  5253 type-inference.
  5254 
  5255 * New simplification procedure for solving continuity conditions; it
  5256 is much faster on terms with many nested lambda abstractions (cubic
  5257 instead of exponential time).
  5258 
  5259 * New syntax for domain package: selector names are now optional.
  5260 Parentheses should be omitted unless argument is lazy, for example:
  5261 
  5262   domain 'a stream = cons "'a" (lazy "'a stream")
  5263 
  5264 * New command 'fixrec' for defining recursive functions with pattern
  5265 matching; defining multiple functions with mutual recursion is also
  5266 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5267 sinr, or any data constructor defined by the domain package. The given
  5268 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5269 syntax and examples.
  5270 
  5271 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5272 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5273 but the proof obligation additionally includes an admissibility
  5274 requirement. The packages generate instances of class cpo or pcpo,
  5275 with continuity and strictness theorems for Rep and Abs.
  5276 
  5277 * HOLCF: Many theorems have been renamed according to a more standard naming
  5278 scheme (INCOMPATIBILITY):
  5279 
  5280   foo_inject:  "foo$x = foo$y ==> x = y"
  5281   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5282   foo_less:    "(foo$x << foo$y) = (x << y)"
  5283   foo_strict:  "foo$UU = UU"
  5284   foo_defined: "... ==> foo$x ~= UU"
  5285   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5286 
  5287 
  5288 *** ZF ***
  5289 
  5290 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5291 including the First Isomorphism Theorem (on quotienting by the kernel
  5292 of a homomorphism).
  5293 
  5294 * ZF/Simplifier: install second copy of type solver that actually
  5295 makes use of TC rules declared to Isar proof contexts (or locales);
  5296 the old version is still required for ML proof scripts.
  5297 
  5298 
  5299 *** Cube ***
  5300 
  5301 * Converted to Isar theory format; use locales instead of axiomatic
  5302 theories.
  5303 
  5304 
  5305 *** ML ***
  5306 
  5307 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5308 for ||>, ||>>, |>>,
  5309 
  5310 * Pure/library.ML no longer defines its own option datatype, but uses
  5311 that of the SML basis, which has constructors NONE and SOME instead of
  5312 None and Some, as well as exception Option.Option instead of OPTION.
  5313 The functions the, if_none, is_some, is_none have been adapted
  5314 accordingly, while Option.map replaces apsome.
  5315 
  5316 * Pure/library.ML: the exception LIST has been given up in favour of
  5317 the standard exceptions Empty and Subscript, as well as
  5318 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5319 superceded by the standard hd and tl functions etc.
  5320 
  5321 A number of basic list functions are no longer exported to the ML
  5322 toplevel, as they are variants of predefined functions.  The following
  5323 suggests how one can translate existing code:
  5324 
  5325     rev_append xs ys = List.revAppend (xs, ys)
  5326     nth_elem (i, xs) = List.nth (xs, i)
  5327     last_elem xs = List.last xs
  5328     flat xss = List.concat xss
  5329     seq fs = List.app fs
  5330     partition P xs = List.partition P xs
  5331     mapfilter f xs = List.mapPartial f xs
  5332 
  5333 * Pure/library.ML: several combinators for linear functional
  5334 transformations, notably reverse application and composition:
  5335 
  5336   x |> f                f #> g
  5337   (x, y) |-> f          f #-> g
  5338 
  5339 * Pure/library.ML: introduced/changed precedence of infix operators:
  5340 
  5341   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5342   infix 2 ?;
  5343   infix 3 o oo ooo oooo;
  5344   infix 4 ~~ upto downto;
  5345 
  5346 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5347 infix operators.
  5348 
  5349 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5350 fold_map support linear functional transformations and nesting.  For
  5351 example:
  5352 
  5353   fold f [x1, ..., xN] y =
  5354     y |> f x1 |> ... |> f xN
  5355 
  5356   (fold o fold) f [xs1, ..., xsN] y =
  5357     y |> fold f xs1 |> ... |> fold f xsN
  5358 
  5359   fold f [x1, ..., xN] =
  5360     f x1 #> ... #> f xN
  5361 
  5362   (fold o fold) f [xs1, ..., xsN] =
  5363     fold f xs1 #> ... #> fold f xsN
  5364 
  5365 * Pure/library.ML: the following selectors on type 'a option are
  5366 available:
  5367 
  5368   the:               'a option -> 'a  (*partial*)
  5369   these:             'a option -> 'a  where 'a = 'b list
  5370   the_default: 'a -> 'a option -> 'a
  5371   the_list:          'a option -> 'a list
  5372 
  5373 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5374 basic operations for association lists, following natural argument
  5375 order; moreover the explicit equality predicate passed here avoids
  5376 potentially expensive polymorphic runtime equality checks.
  5377 The old functions may be expressed as follows:
  5378 
  5379   assoc = uncurry (AList.lookup (op =))
  5380   assocs = these oo AList.lookup (op =)
  5381   overwrite = uncurry (AList.update (op =)) o swap
  5382 
  5383 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5384 
  5385   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5386   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5387 
  5388 replacing make_keylist and keyfilter (occassionally used)
  5389 Naive rewrites:
  5390 
  5391   make_keylist = AList.make
  5392   keyfilter = AList.find (op =)
  5393 
  5394 * eq_fst and eq_snd now take explicit equality parameter, thus
  5395   avoiding eqtypes. Naive rewrites:
  5396 
  5397     eq_fst = eq_fst (op =)
  5398     eq_snd = eq_snd (op =)
  5399 
  5400 * Removed deprecated apl and apr (rarely used).
  5401   Naive rewrites:
  5402 
  5403     apl (n, op) =>>= curry op n
  5404     apr (op, m) =>>= fn n => op (n, m)
  5405 
  5406 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5407 provides a reasonably efficient light-weight implementation of sets as
  5408 lists.
  5409 
  5410 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5411 few new operations; existing lookup and update are now curried to
  5412 follow natural argument order (for use with fold etc.);
  5413 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5414 
  5415 * Pure/General: output via the Isabelle channels of
  5416 writeln/warning/error etc. is now passed through Output.output, with a
  5417 hook for arbitrary transformations depending on the print_mode
  5418 (cf. Output.add_mode -- the first active mode that provides a output
  5419 function wins).  Already formatted output may be embedded into further
  5420 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5421 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5422 accommodate easy composition of diagnostic messages etc.  Programmers
  5423 rarely need to care about Output.output or Output.raw at all, with
  5424 some notable exceptions: Output.output is required when bypassing the
  5425 standard channels (writeln etc.), or in token translations to produce
  5426 properly formatted results; Output.raw is required when capturing
  5427 already output material that will eventually be presented to the user
  5428 a second time.  For the default print mode, both Output.output and
  5429 Output.raw have no effect.
  5430 
  5431 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5432 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5433 cumulative results are displayed at the end of a batch session.
  5434 
  5435 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5436 replaced by File.platform_path and File.shell_path (with appropriate
  5437 hooks).  This provides a clean interface for unusual systems where the
  5438 internal and external process view of file names are different.
  5439 
  5440 * Pure: more efficient orders for basic syntactic entities: added
  5441 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5442 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5443 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5444 orders now -- potential INCOMPATIBILITY for code that depends on a
  5445 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5446 Library.sort_strings on result).
  5447 
  5448 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5449 fold_types traverse types/terms from left to right, observing natural
  5450 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5451 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5452 
  5453 * Pure: name spaces have been refined, with significant changes of the
  5454 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5455 to extern(_table).  The plain name entry path is superceded by a
  5456 general 'naming' context, which also includes the 'policy' to produce
  5457 a fully qualified name and external accesses of a fully qualified
  5458 name; NameSpace.extend is superceded by context dependent
  5459 Sign.declare_name.  Several theory and proof context operations modify
  5460 the naming context.  Especially note Theory.restore_naming and
  5461 ProofContext.restore_naming to get back to a sane state; note that
  5462 Theory.add_path is no longer sufficient to recover from
  5463 Theory.absolute_path in particular.
  5464 
  5465 * Pure: new flags short_names (default false) and unique_names
  5466 (default true) for controlling output of qualified names.  If
  5467 short_names is set, names are printed unqualified.  If unique_names is
  5468 reset, the name prefix is reduced to the minimum required to achieve
  5469 the original result when interning again, even if there is an overlap
  5470 with earlier declarations.
  5471 
  5472 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5473 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5474 (useful for printing error messages).  INCOMPATIBILITY.
  5475 
  5476 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5477 Theory.theory are now identified, referring to the universal
  5478 Context.theory (see Pure/context.ML).  Actual signature and theory
  5479 content is managed as theory data.  The old code and interfaces were
  5480 spread over many files and structures; the new arrangement introduces
  5481 considerable INCOMPATIBILITY to gain more clarity:
  5482 
  5483   Context -- theory management operations (name, identity, inclusion,
  5484     parents, ancestors, merge, etc.), plus generic theory data;
  5485 
  5486   Sign -- logical signature and syntax operations (declaring consts,
  5487     types, etc.), plus certify/read for common entities;
  5488 
  5489   Theory -- logical theory operations (stating axioms, definitions,
  5490     oracles), plus a copy of logical signature operations (consts,
  5491     types, etc.); also a few basic management operations (Theory.copy,
  5492     Theory.merge, etc.)
  5493 
  5494 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5495 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5496 for convenience -- they merely return the theory.
  5497 
  5498 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5499 
  5500 * Pure: the Isar proof context type is already defined early in Pure
  5501 as Context.proof (note that ProofContext.context and Proof.context are
  5502 aliases, where the latter is the preferred name).  This enables other
  5503 Isabelle components to refer to that type even before Isar is present.
  5504 
  5505 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5506 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5507 any of these kinds.  For example, Sign.intern typeK is now
  5508 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5509 Theory.hide_types.  Also note that former
  5510 Theory.hide_classes/types/consts are now
  5511 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5512 internalize their arguments!  INCOMPATIBILITY.
  5513 
  5514 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5515 datatype thmref (with constructors Name and NameSelection) instead of
  5516 plain string -- INCOMPATIBILITY;
  5517 
  5518 * Pure: cases produced by proof methods specify options, where NONE
  5519 means to remove case bindings -- INCOMPATIBILITY in
  5520 (RAW_)METHOD_CASES.
  5521 
  5522 * Pure: the following operations retrieve axioms or theorems from a
  5523 theory node or theory hierarchy, respectively:
  5524 
  5525   Theory.axioms_of: theory -> (string * term) list
  5526   Theory.all_axioms_of: theory -> (string * term) list
  5527   PureThy.thms_of: theory -> (string * thm) list
  5528   PureThy.all_thms_of: theory -> (string * thm) list
  5529 
  5530 * Pure: print_tac now outputs the goal through the trace channel.
  5531 
  5532 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5533 Reference Toplevel.debug (default false) controls detailed printing
  5534 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5535 controls execution profiling -- set to 1 for time and 2 for space
  5536 (both increase the runtime).
  5537 
  5538 * Isar session: The initial use of ROOT.ML is now always timed,
  5539 i.e. the log will show the actual process times, in contrast to the
  5540 elapsed wall-clock time that the outer shell wrapper produces.
  5541 
  5542 * Simplifier: improved handling of bound variables (nameless
  5543 representation, avoid allocating new strings).  Simprocs that invoke
  5544 the Simplifier recursively should use Simplifier.inherit_bounds to
  5545 avoid local name clashes.  Failure to do so produces warnings
  5546 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5547 for further details.
  5548 
  5549 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5550 bindings for all theorems stored within a given theory; this may help
  5551 in porting non-Isar theories to Isar ones, while keeping ML proof
  5552 scripts for the time being.
  5553 
  5554 * ML operator HTML.with_charset specifies the charset begin used for
  5555 generated HTML files.  For example:
  5556 
  5557   HTML.with_charset "utf-8" use_thy "Hebrew";
  5558   HTML.with_charset "utf-8" use_thy "Chinese";
  5559 
  5560 
  5561 *** System ***
  5562 
  5563 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5564 isabelle, isatool etc.).
  5565 
  5566 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5567 isatool doc, isatool mkdir, display_drafts etc.).
  5568 
  5569 * isatool usedir: option -f allows specification of the ML file to be
  5570 used by Isabelle; default is ROOT.ML.
  5571 
  5572 * New isatool version outputs the version identifier of the Isabelle
  5573 distribution being used.
  5574 
  5575 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5576 (containing Boolean satisfiability problems) into Isabelle/HOL
  5577 theories.
  5578 
  5579 
  5580 
  5581 New in Isabelle2004 (April 2004)
  5582 --------------------------------
  5583 
  5584 *** General ***
  5585 
  5586 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5587   Replaces linorder.ML.
  5588 
  5589 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5590   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5591   (\<a>...\<z>), are now considered normal letters, and can therefore
  5592   be used anywhere where an ASCII letter (a...zA...Z) has until
  5593   now. COMPATIBILITY: This obviously changes the parsing of some
  5594   terms, especially where a symbol has been used as a binder, say
  5595   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5596   as an identifier.  Fix it by inserting a space around former
  5597   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5598   existing theory and ML files.
  5599 
  5600 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5601 
  5602 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5603   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5604   a normal (but invisible) letter. For multiple letter subscripts repeat
  5605   \<^isub> like this: x\<^isub>1\<^isub>2.
  5606 
  5607 * Pure: There are now sub-/superscripts that can span more than one
  5608   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5609   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5610   superscript. The new control characters are not identifier parts.
  5611 
  5612 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5613   content of "..." to the latex file instead of \isacntrl... . The "..."
  5614   may consist of any printable characters excluding the end bracket >.
  5615 
  5616 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5617   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5618   declare constants "final", which prevents their being given a definition
  5619   later.  It is useful for constants whose behaviour is fixed axiomatically
  5620   rather than definitionally, such as the meta-logic connectives.
  5621 
  5622 * Pure: 'instance' now handles general arities with general sorts
  5623   (i.e. intersections of classes),
  5624 
  5625 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5626   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5627   It can be changed to alter the colors/layout of generated pages.
  5628 
  5629 
  5630 *** Isar ***
  5631 
  5632 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5633   cut_tac, subgoal_tac and thin_tac:
  5634   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5635     locales are no longer forced to write Isar proof scripts.
  5636     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5637     emulations.
  5638   - INCOMPATIBILITY: names of variables to be instantiated may no
  5639     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5640     This is consistent with the instantiation attribute "where".
  5641 
  5642 * Attributes "where" and "of":
  5643   - Now take type variables of instantiated theorem into account when reading
  5644     the instantiation string.  This fixes a bug that caused instantiated
  5645     theorems to have too special types in some circumstances.
  5646   - "where" permits explicit instantiations of type variables.
  5647 
  5648 * Calculation commands "moreover" and "also" no longer interfere with
  5649   current facts ("this"), admitting arbitrary combinations with "then"
  5650   and derived forms.
  5651 
  5652 * Locales:
  5653   - Goal statements involving the context element "includes" no longer
  5654     generate theorems with internal delta predicates (those ending on
  5655     "_axioms") in the premise.
  5656     Resolve particular premise with <locale>.intro to obtain old form.
  5657   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5658     specification and "includes" elements in goal statement.
  5659   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5660     [intro?] and [elim?] (respectively) by default.
  5661   - Experimental command for instantiation of locales in proof contexts:
  5662         instantiate <label>[<attrs>]: <loc>
  5663     Instantiates locale <loc> and adds all its theorems to the current context
  5664     taking into account their attributes.  Label and attrs are optional
  5665     modifiers, like in theorem declarations.  If present, names of
  5666     instantiated theorems are qualified with <label>, and the attributes
  5667     <attrs> are applied after any attributes these theorems might have already.
  5668       If the locale has assumptions, a chained fact of the form
  5669     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5670     are derived.  The command does not support old-style locales declared
  5671     with "locale (open)".
  5672       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5673 
  5674 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5675   (Isar) contexts.
  5676 
  5677 
  5678 *** HOL ***
  5679 
  5680 * Proof import: new image HOL4 contains the imported library from
  5681   the HOL4 system with about 2500 theorems. It is imported by
  5682   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5683   can be used like any other Isabelle image.  See
  5684   HOL/Import/HOL/README for more information.
  5685 
  5686 * Simplifier:
  5687   - Much improved handling of linear and partial orders.
  5688     Reasoners for linear and partial orders are set up for type classes
  5689     "linorder" and "order" respectively, and are added to the default simpset
  5690     as solvers.  This means that the simplifier can build transitivity chains
  5691     to solve goals from the assumptions.
  5692   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5693     of blast or auto after simplification become unnecessary because the goal
  5694     is solved by simplification already.
  5695 
  5696 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5697     all proved in axiomatic type classes for semirings, rings and fields.
  5698 
  5699 * Numerics:
  5700   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5701     now formalized using the Ring_and_Field theory mentioned above.
  5702   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5703     than before, because now they are set up once in a generic manner.
  5704   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5705     Look for the general versions in Ring_and_Field (and Power if they concern
  5706     exponentiation).
  5707 
  5708 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5709 
  5710 * Records:
  5711   - Record types are now by default printed with their type abbreviation
  5712     instead of the list of all field types. This can be configured via
  5713     the reference "print_record_type_abbr".
  5714   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5715     (not enabled by default).
  5716   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5717     EX x. x = sel r to True (not enabled by default).
  5718   - Tactic "record_split_simp_tac" to split and simplify records added.
  5719 
  5720 * 'specification' command added, allowing for definition by
  5721   specification.  There is also an 'ax_specification' command that
  5722   introduces the new constants axiomatically.
  5723 
  5724 * arith(_tac) is now able to generate counterexamples for reals as well.
  5725 
  5726 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5727 
  5728 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5729   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5730 
  5731 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5732   matrix theory to linear programming.
  5733 
  5734 * Unions and Intersections:
  5735   The latex output syntax of UN and INT has been changed
  5736   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5737   i.e. the index formulae has become a subscript.
  5738   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5739 
  5740 * Unions and Intersections over Intervals:
  5741   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5742   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5743   like in normal math, and corresponding versions for < and for intersection.
  5744 
  5745 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5746   lexicographic dictonary ordering has been added as "lexord".
  5747 
  5748 * ML: the legacy theory structures Int and List have been removed. They had
  5749   conflicted with ML Basis Library structures having the same names.
  5750 
  5751 * 'refute' command added to search for (finite) countermodels.  Only works
  5752   for a fragment of HOL.  The installation of an external SAT solver is
  5753   highly recommended.  See "HOL/Refute.thy" for details.
  5754 
  5755 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5756   formulae under an assignment of free variables to random values.
  5757   In contrast to 'refute', it can deal with inductive datatypes,
  5758   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5759   for examples.
  5760 
  5761 
  5762 *** HOLCF ***
  5763 
  5764 * Streams now come with concatenation and are part of the HOLCF image
  5765 
  5766 
  5767 
  5768 New in Isabelle2003 (May 2003)
  5769 ------------------------------
  5770 
  5771 *** General ***
  5772 
  5773 * Provers/simplifier:
  5774 
  5775   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5776     Assumptions are now subject to complete mutual simplification,
  5777     not just from left to right. The simplifier now preserves
  5778     the order of assumptions.
  5779 
  5780     Potential INCOMPATIBILITY:
  5781 
  5782     -- simp sometimes diverges where the old version did
  5783        not, e.g. invoking simp on the goal
  5784 
  5785         [| P (f x); y = x; f x = f y |] ==> Q
  5786 
  5787        now gives rise to the infinite reduction sequence
  5788 
  5789         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5790 
  5791        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5792        kind of problem.
  5793 
  5794     -- Tactics combining classical reasoner and simplification (such as auto)
  5795        are also affected by this change, because many of them rely on
  5796        simp. They may sometimes diverge as well or yield a different numbers
  5797        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5798        in case of problems. Sometimes subsequent calls to the classical
  5799        reasoner will fail because a preceeding call to the simplifier too
  5800        eagerly simplified the goal, e.g. deleted redundant premises.
  5801 
  5802   - The simplifier trace now shows the names of the applied rewrite rules
  5803 
  5804   - You can limit the number of recursive invocations of the simplifier
  5805     during conditional rewriting (where the simplifie tries to solve the
  5806     conditions before applying the rewrite rule):
  5807     ML "simp_depth_limit := n"
  5808     where n is an integer. Thus you can force termination where previously
  5809     the simplifier would diverge.
  5810 
  5811   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5812 
  5813   - No longer aborts on failed congruence proof.  Instead, the
  5814     congruence is ignored.
  5815 
  5816 * Pure: New generic framework for extracting programs from constructive
  5817   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5818   as HOL/Extraction for some case studies.
  5819 
  5820 * Pure: The main goal of the proof state is no longer shown by default, only
  5821 the subgoals. This behaviour is controlled by a new flag.
  5822    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5823 (ML: Proof.show_main_goal).
  5824 
  5825 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5826 rules whose conclusion matches subgoal 1:
  5827       PG menu: Isabelle/Isar -> Show me -> matching rules
  5828 The rules are ordered by how closely they match the subgoal.
  5829 In particular, rules that solve a subgoal outright are displayed first
  5830 (or rather last, the way they are printed).
  5831 (ML: ProofGeneral.print_intros())
  5832 
  5833 * Pure: New flag trace_unify_fail causes unification to print
  5834 diagnostic information (PG: in trace buffer) when it fails. This is
  5835 useful for figuring out why single step proofs like rule, erule or
  5836 assumption failed.
  5837 
  5838 * Pure: Locale specifications now produce predicate definitions
  5839 according to the body of text (covering assumptions modulo local
  5840 definitions); predicate "loc_axioms" covers newly introduced text,
  5841 while "loc" is cumulative wrt. all included locale expressions; the
  5842 latter view is presented only on export into the global theory
  5843 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5844 on the old view without predicates;
  5845 
  5846 * Pure: predefined locales "var" and "struct" are useful for sharing
  5847 parameters (as in CASL, for example); just specify something like
  5848 ``var x + var y + struct M'' as import;
  5849 
  5850 * Pure: improved thms_containing: proper indexing of facts instead of
  5851 raw theorems; check validity of results wrt. current name space;
  5852 include local facts of proof configuration (also covers active
  5853 locales), cover fixed variables in index; may use "_" in term
  5854 specification; an optional limit for the number of printed facts may
  5855 be given (the default is 40);
  5856 
  5857 * Pure: disallow duplicate fact bindings within new-style theory files
  5858 (batch-mode only);
  5859 
  5860 * Provers: improved induct method: assumptions introduced by case
  5861 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5862 the goal statement); "foo" still refers to all facts collectively;
  5863 
  5864 * Provers: the function blast.overloaded has been removed: all constants
  5865 are regarded as potentially overloaded, which improves robustness in exchange
  5866 for slight decrease in efficiency;
  5867 
  5868 * Provers/linorder: New generic prover for transitivity reasoning over
  5869 linear orders.  Note: this prover is not efficient!
  5870 
  5871 * Isar: preview of problems to finish 'show' now produce an error
  5872 rather than just a warning (in interactive mode);
  5873 
  5874 
  5875 *** HOL ***
  5876 
  5877 * arith(_tac)
  5878 
  5879  - Produces a counter example if it cannot prove a goal.
  5880    Note that the counter example may be spurious if the goal is not a formula
  5881    of quantifier-free linear arithmetic.
  5882    In ProofGeneral the counter example appears in the trace buffer.
  5883 
  5884  - Knows about div k and mod k where k is a numeral of type nat or int.
  5885 
  5886  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5887    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5888    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5889 
  5890 * simp's arithmetic capabilities have been enhanced a bit: it now
  5891 takes ~= in premises into account (by performing a case split);
  5892 
  5893 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5894 are distributed over a sum of terms;
  5895 
  5896 * New tactic "trans_tac" and method "trans" instantiate
  5897 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5898 "<=", "<" and "=").
  5899 
  5900 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5901 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5902 
  5903 * 'typedef' command has new option "open" to suppress the set
  5904 definition;
  5905 
  5906 * functions Min and Max on finite sets have been introduced (theory
  5907 Finite_Set);
  5908 
  5909 * attribute [symmetric] now works for relations as well; it turns
  5910 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5911 
  5912 * induct over a !!-quantified statement (say !!x1..xn):
  5913   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5914 
  5915 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5916 %x. None. Warning: empty_def now refers to the previously hidden definition
  5917 of the empty set.
  5918 
  5919 * Algebra: formalization of classical algebra.  Intended as base for
  5920 any algebraic development in Isabelle.  Currently covers group theory
  5921 (up to Sylow's theorem) and ring theory (Universal Property of
  5922 Univariate Polynomials).  Contributions welcome;
  5923 
  5924 * GroupTheory: deleted, since its material has been moved to Algebra;
  5925 
  5926 * Complex: new directory of the complex numbers with numeric constants,
  5927 nonstandard complex numbers, and some complex analysis, standard and
  5928 nonstandard (Jacques Fleuriot);
  5929 
  5930 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5931 
  5932 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5933 Fleuriot);
  5934 
  5935 * Real/HahnBanach: updated and adapted to locales;
  5936 
  5937 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5938 Gray and Kramer);
  5939 
  5940 * UNITY: added the Meier-Sanders theory of progress sets;
  5941 
  5942 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5943 as abstract algorithms, instantiated to the JVM;
  5944 
  5945 * Bali: Java source language formalization. Type system, operational
  5946 semantics, axiomatic semantics. Supported language features:
  5947 classes, interfaces, objects,virtual methods, static methods,
  5948 static/instance fields, arrays, access modifiers, definite
  5949 assignment, exceptions.
  5950 
  5951 
  5952 *** ZF ***
  5953 
  5954 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5955 universe, etc.);
  5956 
  5957 * Main ZF: virtually all theories converted to new-style format;
  5958 
  5959 
  5960 *** ML ***
  5961 
  5962 * Pure: Tactic.prove provides sane interface for internal proofs;
  5963 omits the infamous "standard" operation, so this is more appropriate
  5964 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5965 
  5966 * Pure: improved error reporting of simprocs;
  5967 
  5968 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5969 up simprocs;
  5970 
  5971 
  5972 *** Document preparation ***
  5973 
  5974 * uses \par instead of \\ for line breaks in theory text. This may
  5975 shift some page breaks in large documents. To get the old behaviour
  5976 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5977 
  5978 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5979 other packages
  5980 
  5981 * \<euro> now needs package babel/greek instead of marvosym (which
  5982 broke \Rightarrow)
  5983 
  5984 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5985 textcomp package)
  5986 
  5987 
  5988 
  5989 New in Isabelle2002 (March 2002)
  5990 --------------------------------
  5991 
  5992 *** Document preparation ***
  5993 
  5994 * greatly simplified document preparation setup, including more
  5995 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5996 instructive isatool mkdir; users should basically be able to get
  5997 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5998 users may run a separate document processing stage manually like this:
  5999 "isatool usedir -D output HOL Test && isatool document Test/output";
  6000 
  6001 * theory dependency graph may now be incorporated into documents;
  6002 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6003 with \includegraphics of LaTeX;
  6004 
  6005 * proper spacing of consecutive markup elements, especially text
  6006 blocks after section headings;
  6007 
  6008 * support bold style (for single symbols only), input syntax is like
  6009 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6010 
  6011 * \<bullet> is now output as bold \cdot by default, which looks much
  6012 better in printed text;
  6013 
  6014 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6015 note that these symbols are currently unavailable in Proof General /
  6016 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6017 
  6018 * isatool latex no longer depends on changed TEXINPUTS, instead
  6019 isatool document copies the Isabelle style files to the target
  6020 location;
  6021 
  6022 
  6023 *** Isar ***
  6024 
  6025 * Pure/Provers: improved proof by cases and induction;
  6026   - 'case' command admits impromptu naming of parameters (such as
  6027     "case (Suc n)");
  6028   - 'induct' method divinates rule instantiation from the inductive
  6029     claim; no longer requires excessive ?P bindings for proper
  6030     instantiation of cases;
  6031   - 'induct' method properly enumerates all possibilities of set/type
  6032     rules; as a consequence facts may be also passed through *type*
  6033     rules without further ado;
  6034   - 'induct' method now derives symbolic cases from the *rulified*
  6035     rule (before it used to rulify cases stemming from the internal
  6036     atomized version); this means that the context of a non-atomic
  6037     statement becomes is included in the hypothesis, avoiding the
  6038     slightly cumbersome show "PROP ?case" form;
  6039   - 'induct' may now use elim-style induction rules without chaining
  6040     facts, using ``missing'' premises from the goal state; this allows
  6041     rules stemming from inductive sets to be applied in unstructured
  6042     scripts, while still benefitting from proper handling of non-atomic
  6043     statements; NB: major inductive premises need to be put first, all
  6044     the rest of the goal is passed through the induction;
  6045   - 'induct' proper support for mutual induction involving non-atomic
  6046     rule statements (uses the new concept of simultaneous goals, see
  6047     below);
  6048   - append all possible rule selections, but only use the first
  6049     success (no backtracking);
  6050   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6051   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6052   - added 'print_induct_rules' (covered by help item in recent Proof
  6053     General versions);
  6054   - moved induct/cases attributes to Pure, methods to Provers;
  6055   - generic method setup instantiated for FOL and HOL;
  6056 
  6057 * Pure: support multiple simultaneous goal statements, for example
  6058 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6059 meta-level mechanism, this acts as if several individual goals had
  6060 been stated separately; in particular common proof methods need to be
  6061 repeated in order to cover all claims; note that a single elimination
  6062 step is *not* sufficient to establish the two conjunctions, so this
  6063 fails:
  6064 
  6065   assume "A & B" then have A and B ..   (*".." fails*)
  6066 
  6067 better use "obtain" in situations as above; alternative refer to
  6068 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6069 
  6070 * Pure: proper integration with ``locales''; unlike the original
  6071 version by Florian Kammller, Isar locales package high-level proof
  6072 contexts rather than raw logical ones (e.g. we admit to include
  6073 attributes everywhere); operations on locales include merge and
  6074 rename; support for implicit arguments (``structures''); simultaneous
  6075 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6076 some examples;
  6077 
  6078 * Pure: the following commands have been ``localized'', supporting a
  6079 target locale specification "(in name)": 'lemma', 'theorem',
  6080 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6081 stored both within the locale and at the theory level (exported and
  6082 qualified by the locale name);
  6083 
  6084 * Pure: theory goals may now be specified in ``long'' form, with
  6085 ad-hoc contexts consisting of arbitrary locale elements. for example
  6086 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6087 definitions may be given, too); the result is a meta-level rule with
  6088 the context elements being discharged in the obvious way;
  6089 
  6090 * Pure: new proof command 'using' allows to augment currently used
  6091 facts after a goal statement ('using' is syntactically analogous to
  6092 'apply', but acts on the goal's facts only); this allows chained facts
  6093 to be separated into parts given before and after a claim, as in
  6094 ``from a and b have C using d and e <proof>'';
  6095 
  6096 * Pure: renamed "antecedent" case to "rule_context";
  6097 
  6098 * Pure: new 'judgment' command records explicit information about the
  6099 object-logic embedding (used by several tools internally); no longer
  6100 use hard-wired "Trueprop";
  6101 
  6102 * Pure: added 'corollary' command;
  6103 
  6104 * Pure: fixed 'token_translation' command;
  6105 
  6106 * Pure: removed obsolete 'exported' attribute;
  6107 
  6108 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6109 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6110 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6111 
  6112 * Pure: method 'atomize' presents local goal premises as object-level
  6113 statements (atomic meta-level propositions); setup controlled via
  6114 rewrite rules declarations of 'atomize' attribute; example
  6115 application: 'induct' method with proper rule statements in improper
  6116 proof *scripts*;
  6117 
  6118 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6119 now consider the syntactic context of assumptions, giving a better
  6120 chance to get type-inference of the arguments right (this is
  6121 especially important for locales);
  6122 
  6123 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6124 mode;
  6125 
  6126 * Pure/obtain: the formal conclusion "thesis", being marked as
  6127 ``internal'', may no longer be reference directly in the text;
  6128 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6129 situations;
  6130 
  6131 * Pure: generic 'sym' attribute which declares a rule both as pure
  6132 'elim?' and for the 'symmetric' operation;
  6133 
  6134 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6135 text; the fixed correlation with particular command syntax has been
  6136 discontinued;
  6137 
  6138 * Pure: new method 'rules' is particularly well-suited for proof
  6139 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6140 but often produces more compact proof terms with less detours;
  6141 
  6142 * Pure/Provers/classical: simplified integration with pure rule
  6143 attributes and methods; the classical "intro?/elim?/dest?"
  6144 declarations coincide with the pure ones; the "rule" method no longer
  6145 includes classically swapped intros; "intro" and "elim" methods no
  6146 longer pick rules from the context; also got rid of ML declarations
  6147 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6148 INCOMPATIBILITY;
  6149 
  6150 * Provers/classical: attribute 'swapped' produces classical inversions
  6151 of introduction rules;
  6152 
  6153 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6154 rules instead of full simplifier context; 'iff' attribute handles
  6155 conditional rules;
  6156 
  6157 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6158 
  6159 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6160 "(permissive)" option to recover old behavior;
  6161 
  6162 * HOL: 'inductive' no longer features separate (collective) attributes
  6163 for 'intros' (was found too confusing);
  6164 
  6165 * HOL: properly declared induction rules less_induct and
  6166 wf_induct_rule;
  6167 
  6168 
  6169 *** HOL ***
  6170 
  6171 * HOL: moved over to sane numeral syntax; the new policy is as
  6172 follows:
  6173 
  6174   - 0 and 1 are polymorphic constants, which are defined on any
  6175   numeric type (nat, int, real etc.);
  6176 
  6177   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6178   binary representation internally;
  6179 
  6180   - type nat has special constructor Suc, and generally prefers Suc 0
  6181   over 1::nat and Suc (Suc 0) over 2::nat;
  6182 
  6183 This change may cause significant problems of INCOMPATIBILITY; here
  6184 are some hints on converting existing sources:
  6185 
  6186   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6187   entities, so expressions involving "-" (unary or binary minus) need
  6188   to be spaced properly;
  6189 
  6190   - existing occurrences of "1" may need to be constraint "1::nat" or
  6191   even replaced by Suc 0; similar for old "2";
  6192 
  6193   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6194 
  6195   - remove all special provisions on numerals in proofs;
  6196 
  6197 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6198 representation (depends on bin_arith_simps in the default context);
  6199 
  6200 * HOL: symbolic syntax for x^2 (numeral 2);
  6201 
  6202 * HOL: the class of all HOL types is now called "type" rather than
  6203 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6204 in axclass/classes, instance/arities, and (usually rare) occurrences
  6205 in typings (of consts etc.); internally the class is called
  6206 "HOL.type", ML programs should refer to HOLogic.typeS;
  6207 
  6208 * HOL/record package improvements:
  6209   - new derived operations "fields" to build a partial record section,
  6210     "extend" to promote a fixed record to a record scheme, and
  6211     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6212     declared as simp by default;
  6213   - shared operations ("more", "fields", etc.) now need to be always
  6214     qualified) --- potential INCOMPATIBILITY;
  6215   - removed "make_scheme" operations (use "make" with "extend") --
  6216     INCOMPATIBILITY;
  6217   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6218   - provides cases/induct rules for use with corresponding Isar
  6219     methods (for concrete records, record schemes, concrete more
  6220     parts, and schematic more parts -- in that order);
  6221   - internal definitions directly based on a light-weight abstract
  6222     theory of product types over typedef rather than datatype;
  6223 
  6224 * HOL: generic code generator for generating executable ML code from
  6225 specifications; specific support for HOL constructs such as inductive
  6226 datatypes and sets, as well as recursive functions; can be invoked
  6227 via 'generate_code' theory section;
  6228 
  6229 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6230 
  6231 * HOL: consolidated and renamed several theories.  In particul