NEWS
author ballarin
Thu Jun 23 12:02:54 2011 +0200 (2011-06-23)
changeset 43527 1aacef7471c2
parent 43319 048c7eea1a71
child 43565 486b56f2139c
child 43570 ccfb3623a68a
permissions -rw-r--r--
Release notes should be written from the user's perspective. Don't assume the user has universal knowledge of the system.
     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) has been discontinued.
    26 Note that the path element ~~ may be used to reference theories in the
    27 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
    28 INCOMPATIBILITY.
    29 
    30 * Various optional external tools are referenced more robustly and
    31 uniformly by explicit Isabelle settings as follows:
    32 
    33   ISABELLE_CSDP   (formerly CSDP_EXE)
    34   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    35   ISABELLE_OCAML  (formerly EXEC_OCAML)
    36   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    37   ISABELLE_YAP    (formerly EXEC_YAP)
    38 
    39 Note that automated detection from the file-system or search path has
    40 been discontinued.  INCOMPATIBILITY.
    41 
    42 * Name space: former unsynchronized references are now proper
    43 configuration options, with more conventional names:
    44 
    45   long_names   ~> names_long
    46   short_names  ~> names_short
    47   unique_names ~> names_unique
    48 
    49 Minor INCOMPATIBILITY, need to declare options in context like this:
    50 
    51   declare [[names_unique = false]]
    52 
    53 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    54 that the result needs to be unique, which means fact specifications
    55 may have to be refined after enriching a proof context.
    56 
    57 * Isabelle/Isar reference manual provides more formal references in
    58 syntax diagrams.
    59 
    60 
    61 *** HOL ***
    62 
    63 * Finite_Set.thy: more coherent development of fold_set locales:
    64 
    65     locale fun_left_comm ~> locale comp_fun_commute
    66     locale fun_left_comm_idem ~> locale comp_fun_idem
    67     
    68 Both use point-free characterisation; interpretation proofs may need adjustment.
    69 INCOMPATIBILITY.
    70 
    71 * Code generation:
    72   - theory Library/Code_Char_ord provides native ordering of characters
    73     in the target language.
    74     
    75 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    76 
    77 * Nitpick:
    78   - Added "need" and "total_consts" options.
    79   - Reintroduced "show_skolems" option by popular demand.
    80   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    81     INCOMPATIBILITY.
    82 
    83 * Sledgehammer:
    84   - sledgehammer available_provers ~> sledgehammer supported_provers
    85     INCOMPATIBILITY.
    86   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    87     TPTP problems (TFF).
    88   - Added "type_sys", "max_mono_iters", and "max_new_mono_instances" options.
    89 
    90 * Metis:
    91   - Removed "metisF" -- use "metis" instead.
    92   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
    93 
    94 * "try":
    95   - Added "simp:", "intro:", and "elim:" options.
    96 
    97 * Quickcheck:
    98   - Added "eval" option to evaluate terms for the found counterexample
    99     (currently only supported by the default (exhaustive) tester)
   100   - Added post-processing of terms to obtain readable counterexamples
   101     (currently only supported by the default (exhaustive) tester)
   102   - New counterexample generator quickcheck[narrowing] enables
   103     narrowing-based testing.
   104     It requires that the Glasgow Haskell compiler is installed and
   105     its location is known to Isabelle with the environment variable
   106     ISABELLE_GHC.
   107 
   108 * Function package: discontinued option "tailrec".
   109 INCOMPATIBILITY. Use partial_function instead.
   110 
   111 * HOL-Probability:
   112   - Caratheodory's extension lemma is now proved for ring_of_sets.
   113   - Infinite products of probability measures are now available.
   114   - Use extended reals instead of positive extended reals.
   115     INCOMPATIBILITY.
   116 
   117 
   118 *** Document preparation ***
   119 
   120 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   121 isar-ref manual.
   122 
   123 * Localized \isabellestyle switch can be used within blocks or groups
   124 like this:
   125 
   126   \isabellestyle{it}  %preferred default
   127   {\isabellestylett @{text "typewriter stuff"}}
   128 
   129 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   130 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   131 
   132 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   133 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   134 
   135 
   136 *** ML ***
   137 
   138 * Isabelle_Process.is_active allows tools to check if the official
   139 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   140 (better known as Proof General).
   141 
   142 * Structure Proof_Context follows standard naming scheme.  Old
   143 ProofContext is still available for some time as legacy alias.
   144 
   145 * Structure Timing provides various operations for timing; supersedes
   146 former start_timing/end_timing etc.
   147 
   148 * Path.print is the official way to show file-system paths to users
   149 (including quotes etc.).
   150 
   151 * Inner syntax: identifiers in parse trees of generic categories
   152 "logic", "aprop", "idt" etc. carry position information (disguised as
   153 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   154 translations that choke on unexpected type constraints.  Positions can
   155 be stripped in ML translations via Syntax.strip_positions /
   156 Syntax.strip_positions_ast, or via the syntax constant
   157 "_strip_positions" within parse trees.  As last resort, positions can
   158 be disabled via the configuration option Syntax.positions, which is
   159 called "syntax_positions" in Isar attribute syntax.
   160 
   161 * Discontinued special status of various ML structures that contribute
   162 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   163 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   164 refer directly to Ast.Constant, Lexicon.is_identifier,
   165 Syntax_Trans.mk_binder_tr etc.
   166 
   167 * Typed print translation: discontinued show_sorts argument, which is
   168 already available via context of "advanced" translation.
   169 
   170 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   171 goal states; body tactic needs to address all subgoals uniformly.
   172 
   173 * Slightly more special eq_list/eq_set, with shortcut involving
   174 pointer equality (assumes that eq relation is reflexive).
   175 
   176 * Classical tactics use proper Proof.context instead of historic types
   177 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   178 operate directly on Proof.context.  Raw type claset retains its use as
   179 snapshot of the classical context, which can be recovered via
   180 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   181 INCOMPATIBILITY, classical tactics and derived proof methods require
   182 proper Proof.context.
   183 
   184 
   185 
   186 New in Isabelle2011 (January 2011)
   187 ----------------------------------
   188 
   189 *** General ***
   190 
   191 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   192 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   193 useful tooltips and hyperlinks produced from its static analysis.  The
   194 bundled component provides an executable Isabelle tool that can be run
   195 like this:
   196 
   197   Isabelle2011/bin/isabelle jedit
   198 
   199 * Significantly improved Isabelle/Isar implementation manual.
   200 
   201 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   202 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   203 while the default heap location within that directory lacks that extra
   204 suffix.  This isolates multiple Isabelle installations from each
   205 other, avoiding problems with old settings in new versions.
   206 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   207 
   208 * Source files are always encoded as UTF-8, instead of old-fashioned
   209 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   210 the following package declarations:
   211 
   212   \usepackage[utf8]{inputenc}
   213   \usepackage{textcomp}
   214 
   215 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   216 a Unicode character is treated as a single symbol, not a sequence of
   217 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   218 contain symbols without further backslash escapes, Unicode can now be
   219 used here as well.  Recall that Symbol.explode in ML provides a
   220 consistent view on symbols, while raw explode (or String.explode)
   221 merely give a byte-oriented representation.
   222 
   223 * Theory loader: source files are primarily located via the master
   224 directory of each theory node (where the .thy file itself resides).
   225 The global load path is still partially available as legacy feature.
   226 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   227 explicit paths, relatively to the theory.
   228 
   229 * Special treatment of ML file names has been discontinued.
   230 Historically, optional extensions .ML or .sml were added on demand --
   231 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   232 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   233 
   234 * Various options that affect pretty printing etc. are now properly
   235 handled within the context via configuration options, instead of
   236 unsynchronized references or print modes.  There are both ML Config.T
   237 entities and Isar declaration attributes to access these.
   238 
   239   ML (Config.T)                 Isar (attribute)
   240 
   241   eta_contract                  eta_contract
   242   show_brackets                 show_brackets
   243   show_sorts                    show_sorts
   244   show_types                    show_types
   245   show_question_marks           show_question_marks
   246   show_consts                   show_consts
   247   show_abbrevs                  show_abbrevs
   248 
   249   Syntax.ast_trace              syntax_ast_trace
   250   Syntax.ast_stat               syntax_ast_stat
   251   Syntax.ambiguity_level        syntax_ambiguity_level
   252 
   253   Goal_Display.goals_limit      goals_limit
   254   Goal_Display.show_main_goal   show_main_goal
   255 
   256   Method.rule_trace             rule_trace
   257 
   258   Thy_Output.display            thy_output_display
   259   Thy_Output.quotes             thy_output_quotes
   260   Thy_Output.indent             thy_output_indent
   261   Thy_Output.source             thy_output_source
   262   Thy_Output.break              thy_output_break
   263 
   264 Note that corresponding "..._default" references in ML may only be
   265 changed globally at the ROOT session setup, but *not* within a theory.
   266 The option "show_abbrevs" supersedes the former print mode
   267 "no_abbrevs" with inverted meaning.
   268 
   269 * More systematic naming of some configuration options.
   270 INCOMPATIBILITY.
   271 
   272   trace_simp  ~>  simp_trace
   273   debug_simp  ~>  simp_debug
   274 
   275 * Support for real valued configuration options, using simplistic
   276 floating-point notation that coincides with the inner syntax for
   277 float_token.
   278 
   279 * Support for real valued preferences (with approximative PGIP type):
   280 front-ends need to accept "pgint" values in float notation.
   281 INCOMPATIBILITY.
   282 
   283 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   284 DejaVu Sans.
   285 
   286 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   287 
   288 
   289 *** Pure ***
   290 
   291 * Command 'type_synonym' (with single argument) replaces somewhat
   292 outdated 'types', which is still available as legacy feature for some
   293 time.
   294 
   295 * Command 'nonterminal' (with 'and' separated list of arguments)
   296 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   297 
   298 * Command 'notepad' replaces former 'example_proof' for
   299 experimentation in Isar without any result.  INCOMPATIBILITY.
   300 
   301 * Locale interpretation commands 'interpret' and 'sublocale' accept
   302 lists of equations to map definitions in a locale to appropriate
   303 entities in the context of the interpretation.  The 'interpretation'
   304 command already provided this functionality.
   305 
   306 * Diagnostic command 'print_dependencies' prints the locale instances
   307 that would be activated if the specified expression was interpreted in
   308 the current context.  Variant "print_dependencies!" assumes a context
   309 without interpretations.
   310 
   311 * Diagnostic command 'print_interps' prints interpretations in proofs
   312 in addition to interpretations in theories.
   313 
   314 * Discontinued obsolete 'global' and 'local' commands to manipulate
   315 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   316 Sign.root_path and Sign.local_path may be applied directly where this
   317 feature is still required for historical reasons.
   318 
   319 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   320 'definition' instead.
   321 
   322 * The "prems" fact, which refers to the accidental collection of
   323 foundational premises in the context, is now explicitly marked as
   324 legacy feature and will be discontinued soon.  Consider using "assms"
   325 of the head statement or reference facts by explicit names.
   326 
   327 * Document antiquotations @{class} and @{type} print classes and type
   328 constructors.
   329 
   330 * Document antiquotation @{file} checks file/directory entries within
   331 the local file system.
   332 
   333 
   334 *** HOL ***
   335 
   336 * Coercive subtyping: functions can be declared as coercions and type
   337 inference will add them as necessary upon input of a term.  Theory
   338 Complex_Main declares real :: nat => real and real :: int => real as
   339 coercions. A coercion function f is declared like this:
   340 
   341   declare [[coercion f]]
   342 
   343 To lift coercions through type constructors (e.g. from nat => real to
   344 nat list => real list), map functions can be declared, e.g.
   345 
   346   declare [[coercion_map map]]
   347 
   348 Currently coercion inference is activated only in theories including
   349 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   350 the configuration option "coercion_enabled", e.g. it can be enabled in
   351 other theories like this:
   352 
   353   declare [[coercion_enabled]]
   354 
   355 * Command 'partial_function' provides basic support for recursive
   356 function definitions over complete partial orders.  Concrete instances
   357 are provided for i) the option type, ii) tail recursion on arbitrary
   358 types, and iii) the heap monad of Imperative_HOL.  See
   359 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   360 for examples.
   361 
   362 * Function package: f.psimps rules are no longer implicitly declared
   363 as [simp].  INCOMPATIBILITY.
   364 
   365 * Datatype package: theorems generated for executable equality (class
   366 "eq") carry proper names and are treated as default code equations.
   367 
   368 * Inductive package: now offers command 'inductive_simps' to
   369 automatically derive instantiated and simplified equations for
   370 inductive predicates, similar to 'inductive_cases'.
   371 
   372 * Command 'enriched_type' allows to register properties of the
   373 functorial structure of types.
   374 
   375 * Improved infrastructure for term evaluation using code generator
   376 techniques, in particular static evaluation conversions.
   377 
   378 * Code generator: Scala (2.8 or higher) has been added to the target
   379 languages.
   380 
   381 * Code generator: globbing constant expressions "*" and "Theory.*"
   382 have been replaced by the more idiomatic "_" and "Theory._".
   383 INCOMPATIBILITY.
   384 
   385 * Code generator: export_code without explicit file declaration prints
   386 to standard output.  INCOMPATIBILITY.
   387 
   388 * Code generator: do not print function definitions for case
   389 combinators any longer.
   390 
   391 * Code generator: simplification with rules determined with
   392 src/Tools/Code/code_simp.ML and method "code_simp".
   393 
   394 * Code generator for records: more idiomatic representation of record
   395 types.  Warning: records are not covered by ancient SML code
   396 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   397 rep_datatype declaration helps to succeed then:
   398 
   399   record 'a foo = ...
   400   ...
   401   rep_datatype foo_ext ...
   402 
   403 * Records: logical foundation type for records does not carry a
   404 '_type' suffix any longer (obsolete due to authentic syntax).
   405 INCOMPATIBILITY.
   406 
   407 * Quickcheck now by default uses exhaustive testing instead of random
   408 testing.  Random testing can be invoked by "quickcheck [random]",
   409 exhaustive testing by "quickcheck [exhaustive]".
   410 
   411 * Quickcheck instantiates polymorphic types with small finite
   412 datatypes by default. This enables a simple execution mechanism to
   413 handle quantifiers and function equality over the finite datatypes.
   414 
   415 * Quickcheck random generator has been renamed from "code" to
   416 "random".  INCOMPATIBILITY.
   417 
   418 * Quickcheck now has a configurable time limit which is set to 30
   419 seconds by default. This can be changed by adding [timeout = n] to the
   420 quickcheck command. The time limit for Auto Quickcheck is still set
   421 independently.
   422 
   423 * Quickcheck in locales considers interpretations of that locale for
   424 counter example search.
   425 
   426 * Sledgehammer:
   427   - Added "smt" and "remote_smt" provers based on the "smt" proof
   428     method. See the Sledgehammer manual for details ("isabelle doc
   429     sledgehammer").
   430   - Renamed commands:
   431     sledgehammer atp_info ~> sledgehammer running_provers
   432     sledgehammer atp_kill ~> sledgehammer kill_provers
   433     sledgehammer available_atps ~> sledgehammer available_provers
   434     INCOMPATIBILITY.
   435   - Renamed options:
   436     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   437     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   438     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   439     (and "ms" and "min" are no longer supported)
   440     INCOMPATIBILITY.
   441 
   442 * Nitpick:
   443   - Renamed options:
   444     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   445     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   446     INCOMPATIBILITY.
   447   - Added support for partial quotient types.
   448   - Added local versions of the "Nitpick.register_xxx" functions.
   449   - Added "whack" option.
   450   - Allow registration of quotient types as codatatypes.
   451   - Improved "merge_type_vars" option to merge more types.
   452   - Removed unsound "fast_descrs" option.
   453   - Added custom symmetry breaking for datatypes, making it possible to reach
   454     higher cardinalities.
   455   - Prevent the expansion of too large definitions.
   456 
   457 * Proof methods "metis" and "meson" now have configuration options
   458 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   459 to diagnose these tools. E.g.
   460 
   461     using [[metis_trace = true]]
   462 
   463 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   464 manually as command 'solve_direct'.
   465 
   466 * The default SMT solver Z3 must be enabled explicitly (due to
   467 licensing issues) by setting the environment variable
   468 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   469 commercial applications, the SMT solver CVC3 is provided as fall-back;
   470 changing the SMT solver is done via the configuration option
   471 "smt_solver".
   472 
   473 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   474 i.e. "remote_cvc3" and "remote_z3".
   475 
   476 * Added basic SMT support for datatypes, records, and typedefs using
   477 the oracle mode (no proofs).  Direct support of pairs has been dropped
   478 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   479 support for a similar behavior).  Minor INCOMPATIBILITY.
   480 
   481 * Changed SMT configuration options:
   482   - Renamed:
   483     z3_proofs ~> smt_oracle (with inverted meaning)
   484     z3_trace_assms ~> smt_trace_used_facts
   485     INCOMPATIBILITY.
   486   - Added:
   487     smt_verbose
   488     smt_random_seed
   489     smt_datatypes
   490     smt_infer_triggers
   491     smt_monomorph_limit
   492     cvc3_options
   493     remote_cvc3_options
   494     remote_z3_options
   495     yices_options
   496 
   497 * Boogie output files (.b2i files) need to be declared in the theory
   498 header.
   499 
   500 * Simplification procedure "list_to_set_comprehension" rewrites list
   501 comprehensions applied to List.set to set comprehensions.  Occasional
   502 INCOMPATIBILITY, may be deactivated like this:
   503 
   504   declare [[simproc del: list_to_set_comprehension]]
   505 
   506 * Removed old version of primrec package.  INCOMPATIBILITY.
   507 
   508 * Removed simplifier congruence rule of "prod_case", as has for long
   509 been the case with "split".  INCOMPATIBILITY.
   510 
   511 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   512 
   513 * Removed [split_format ... and ... and ...] version of
   514 [split_format].  Potential INCOMPATIBILITY.
   515 
   516 * Predicate "sorted" now defined inductively, with nice induction
   517 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   518 
   519 * Constant "contents" renamed to "the_elem", to free the generic name
   520 contents for other uses.  INCOMPATIBILITY.
   521 
   522 * Renamed class eq and constant eq (for code generation) to class
   523 equal and constant equal, plus renaming of related facts and various
   524 tuning.  INCOMPATIBILITY.
   525 
   526 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   527 
   528 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   529 INCOMPATIBILITY.
   530 
   531 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   532 avoid confusion with finite sets.  INCOMPATIBILITY.
   533 
   534 * Abandoned locales equiv, congruent and congruent2 for equivalence
   535 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   536 for congruent(2)).
   537 
   538 * Some previously unqualified names have been qualified:
   539 
   540   types
   541     bool ~> HOL.bool
   542     nat ~> Nat.nat
   543 
   544   constants
   545     Trueprop ~> HOL.Trueprop
   546     True ~> HOL.True
   547     False ~> HOL.False
   548     op & ~> HOL.conj
   549     op | ~> HOL.disj
   550     op --> ~> HOL.implies
   551     op = ~> HOL.eq
   552     Not ~> HOL.Not
   553     The ~> HOL.The
   554     All ~> HOL.All
   555     Ex ~> HOL.Ex
   556     Ex1 ~> HOL.Ex1
   557     Let ~> HOL.Let
   558     If ~> HOL.If
   559     Ball ~> Set.Ball
   560     Bex ~> Set.Bex
   561     Suc ~> Nat.Suc
   562     Pair ~> Product_Type.Pair
   563     fst ~> Product_Type.fst
   564     snd ~> Product_Type.snd
   565     curry ~> Product_Type.curry
   566     op : ~> Set.member
   567     Collect ~> Set.Collect
   568 
   569 INCOMPATIBILITY.
   570 
   571 * More canonical naming convention for some fundamental definitions:
   572 
   573     bot_bool_eq ~> bot_bool_def
   574     top_bool_eq ~> top_bool_def
   575     inf_bool_eq ~> inf_bool_def
   576     sup_bool_eq ~> sup_bool_def
   577     bot_fun_eq  ~> bot_fun_def
   578     top_fun_eq  ~> top_fun_def
   579     inf_fun_eq  ~> inf_fun_def
   580     sup_fun_eq  ~> sup_fun_def
   581 
   582 INCOMPATIBILITY.
   583 
   584 * More stylized fact names:
   585 
   586   expand_fun_eq ~> fun_eq_iff
   587   expand_set_eq ~> set_eq_iff
   588   set_ext       ~> set_eqI
   589   nat_number    ~> eval_nat_numeral
   590 
   591 INCOMPATIBILITY.
   592 
   593 * Refactoring of code-generation specific operations in theory List:
   594 
   595   constants
   596     null ~> List.null
   597 
   598   facts
   599     mem_iff ~> member_def
   600     null_empty ~> null_def
   601 
   602 INCOMPATIBILITY.  Note that these were not supposed to be used
   603 regularly unless for striking reasons; their main purpose was code
   604 generation.
   605 
   606 Various operations from the Haskell prelude are used for generating
   607 Haskell code.
   608 
   609 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   610 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   611 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   612 
   613 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   614 "*" and "+" respectively.  INCOMPATIBILITY.
   615 
   616 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   617 "Sum_Type.Plus" instead.
   618 
   619 * Constant "split" has been merged with constant "prod_case"; names of
   620 ML functions, facts etc. involving split have been retained so far,
   621 though.  INCOMPATIBILITY.
   622 
   623 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   624 instead.  INCOMPATIBILITY.
   625 
   626 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   627 INCOMPATIBILITY.
   628 
   629 * Former theory Library/Enum is now part of the HOL-Main image.
   630 INCOMPATIBILITY: all constants of the Enum theory now have to be
   631 referred to by its qualified name.
   632 
   633   enum    ~>  Enum.enum
   634   nlists  ~>  Enum.nlists
   635   product ~>  Enum.product
   636 
   637 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   638 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   639 INCOMPATIBILITY.
   640 
   641 * Theory Library/SetsAndFunctions has been split into
   642 Library/Function_Algebras and Library/Set_Algebras; canonical names
   643 for instance definitions for functions; various improvements.
   644 INCOMPATIBILITY.
   645 
   646 * Theory Library/Multiset provides stable quicksort implementation of
   647 sort_key.
   648 
   649 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   650 INCOMPATIBILITY.
   651 
   652 * Session Multivariate_Analysis: introduced a type class for euclidean
   653 space.  Most theorems are now stated in terms of euclidean spaces
   654 instead of finite cartesian products.
   655 
   656   types
   657     real ^ 'n ~>  'a::real_vector
   658               ~>  'a::euclidean_space
   659               ~>  'a::ordered_euclidean_space
   660         (depends on your needs)
   661 
   662   constants
   663      _ $ _        ~> _ $$ _
   664      \<chi> x. _  ~> \<chi>\<chi> x. _
   665      CARD('n)     ~> DIM('a)
   666 
   667 Also note that the indices are now natural numbers and not from some
   668 finite type. Finite cartesian products of euclidean spaces, products
   669 of euclidean spaces the real and complex numbers are instantiated to
   670 be euclidean_spaces.  INCOMPATIBILITY.
   671 
   672 * Session Probability: introduced pextreal as positive extended real
   673 numbers.  Use pextreal as value for measures.  Introduce the
   674 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   675 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   676 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   677 
   678 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   679 INCOMPATIBILITY.
   680 
   681 * Session SPARK (with image HOL-SPARK) provides commands to load and
   682 prove verification conditions generated by the SPARK Ada program
   683 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   684 
   685 
   686 *** HOL-Algebra ***
   687 
   688 * Theorems for additive ring operations (locale abelian_monoid and
   689 descendants) are generated by interpretation from their multiplicative
   690 counterparts.  Names (in particular theorem names) have the mandatory
   691 qualifier 'add'.  Previous theorem names are redeclared for
   692 compatibility.
   693 
   694 * Structure "int_ring" is now an abbreviation (previously a
   695 definition).  This fits more natural with advanced interpretations.
   696 
   697 
   698 *** HOLCF ***
   699 
   700 * The domain package now runs in definitional mode by default: The
   701 former command 'new_domain' is now called 'domain'.  To use the domain
   702 package in its original axiomatic mode, use 'domain (unsafe)'.
   703 INCOMPATIBILITY.
   704 
   705 * The new class "domain" is now the default sort.  Class "predomain"
   706 is an unpointed version of "domain". Theories can be updated by
   707 replacing sort annotations as shown below.  INCOMPATIBILITY.
   708 
   709   'a::type ~> 'a::countable
   710   'a::cpo  ~> 'a::predomain
   711   'a::pcpo ~> 'a::domain
   712 
   713 * The old type class "rep" has been superseded by class "domain".
   714 Accordingly, users of the definitional package must remove any
   715 "default_sort rep" declarations.  INCOMPATIBILITY.
   716 
   717 * The domain package (definitional mode) now supports unpointed
   718 predomain argument types, as long as they are marked 'lazy'. (Strict
   719 arguments must be in class "domain".) For example, the following
   720 domain definition now works:
   721 
   722   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   723 
   724 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   725 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   726 'a option, and 'a list.  Additionally, it configures fixrec and the
   727 domain package to work with these types.  For example:
   728 
   729   fixrec isInl :: "('a + 'b) u -> tr"
   730     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   731 
   732   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   733 
   734 * The "(permissive)" option of fixrec has been replaced with a
   735 per-equation "(unchecked)" option. See
   736 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   737 
   738 * The "bifinite" class no longer fixes a constant "approx"; the class
   739 now just asserts that such a function exists.  INCOMPATIBILITY.
   740 
   741 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   742 defines an embedding of type 'a defl into udom by default; instances
   743 of "bifinite" and "domain" classes are available in
   744 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   745 
   746 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   747 
   748 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   749 
   750 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   751 
   752 * The function "cprod_map" has been renamed to "prod_map".
   753 INCOMPATIBILITY.
   754 
   755 * The monadic bind operator on each powerdomain has new binder syntax
   756 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   757 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   758 
   759 * The infix syntax for binary union on each powerdomain has changed
   760 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   761 syntax.  INCOMPATIBILITY.
   762 
   763 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   764 still supported as an input translation.
   765 
   766 * Renamed some theorems (the original names are also still available).
   767 
   768   expand_fun_below   ~> fun_below_iff
   769   below_fun_ext      ~> fun_belowI
   770   expand_cfun_eq     ~> cfun_eq_iff
   771   ext_cfun           ~> cfun_eqI
   772   expand_cfun_below  ~> cfun_below_iff
   773   below_cfun_ext     ~> cfun_belowI
   774   cont2cont_Rep_CFun ~> cont2cont_APP
   775 
   776 * The Abs and Rep functions for various types have changed names.
   777 Related theorem names have also changed to match. INCOMPATIBILITY.
   778 
   779   Rep_CFun  ~> Rep_cfun
   780   Abs_CFun  ~> Abs_cfun
   781   Rep_Sprod ~> Rep_sprod
   782   Abs_Sprod ~> Abs_sprod
   783   Rep_Ssum  ~> Rep_ssum
   784   Abs_Ssum  ~> Abs_ssum
   785 
   786 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   787 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   788 
   789 * Various changes to bisimulation/coinduction with domain package:
   790 
   791   - Definitions of "bisim" constants no longer mention definedness.
   792   - With mutual recursion, "bisim" predicate is now curried.
   793   - With mutual recursion, each type gets a separate coind theorem.
   794   - Variable names in bisim_def and coinduct rules have changed.
   795 
   796 INCOMPATIBILITY.
   797 
   798 * Case combinators generated by the domain package for type "foo" are
   799 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   800 
   801 * Several theorems have been renamed to more accurately reflect the
   802 names of constants and types involved.  INCOMPATIBILITY.
   803 
   804   thelub_const    ~> lub_const
   805   lub_const       ~> is_lub_const
   806   thelubI         ~> lub_eqI
   807   is_lub_lub      ~> is_lubD2
   808   lubI            ~> is_lub_lub
   809   unique_lub      ~> is_lub_unique
   810   is_ub_lub       ~> is_lub_rangeD1
   811   lub_bin_chain   ~> is_lub_bin_chain
   812   lub_fun         ~> is_lub_fun
   813   thelub_fun      ~> lub_fun
   814   thelub_cfun     ~> lub_cfun
   815   thelub_Pair     ~> lub_Pair
   816   lub_cprod       ~> is_lub_prod
   817   thelub_cprod    ~> lub_prod
   818   minimal_cprod   ~> minimal_prod
   819   inst_cprod_pcpo ~> inst_prod_pcpo
   820   UU_I            ~> bottomI
   821   compact_UU      ~> compact_bottom
   822   deflation_UU    ~> deflation_bottom
   823   finite_deflation_UU ~> finite_deflation_bottom
   824 
   825 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   826 
   827   sq_ord_less_eq_trans ~> below_eq_trans
   828   sq_ord_eq_less_trans ~> eq_below_trans
   829   refl_less            ~> below_refl
   830   trans_less           ~> below_trans
   831   antisym_less         ~> below_antisym
   832   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   833   box_less             ~> box_below
   834   rev_trans_less       ~> rev_below_trans
   835   not_less2not_eq      ~> not_below2not_eq
   836   less_UU_iff          ~> below_UU_iff
   837   flat_less_iff        ~> flat_below_iff
   838   adm_less             ~> adm_below
   839   adm_not_less         ~> adm_not_below
   840   adm_compact_not_less ~> adm_compact_not_below
   841   less_fun_def         ~> below_fun_def
   842   expand_fun_less      ~> fun_below_iff
   843   less_fun_ext         ~> fun_belowI
   844   less_discr_def       ~> below_discr_def
   845   discr_less_eq        ~> discr_below_eq
   846   less_unit_def        ~> below_unit_def
   847   less_cprod_def       ~> below_prod_def
   848   prod_lessI           ~> prod_belowI
   849   Pair_less_iff        ~> Pair_below_iff
   850   fst_less_iff         ~> fst_below_iff
   851   snd_less_iff         ~> snd_below_iff
   852   expand_cfun_less     ~> cfun_below_iff
   853   less_cfun_ext        ~> cfun_belowI
   854   injection_less       ~> injection_below
   855   less_up_def          ~> below_up_def
   856   not_Iup_less         ~> not_Iup_below
   857   Iup_less             ~> Iup_below
   858   up_less              ~> up_below
   859   Def_inject_less_eq   ~> Def_below_Def
   860   Def_less_is_eq       ~> Def_below_iff
   861   spair_less_iff       ~> spair_below_iff
   862   less_sprod           ~> below_sprod
   863   spair_less           ~> spair_below
   864   sfst_less_iff        ~> sfst_below_iff
   865   ssnd_less_iff        ~> ssnd_below_iff
   866   fix_least_less       ~> fix_least_below
   867   dist_less_one        ~> dist_below_one
   868   less_ONE             ~> below_ONE
   869   ONE_less_iff         ~> ONE_below_iff
   870   less_sinlD           ~> below_sinlD
   871   less_sinrD           ~> below_sinrD
   872 
   873 
   874 *** FOL and ZF ***
   875 
   876 * All constant names are now qualified internally and use proper
   877 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   878 
   879 
   880 *** ML ***
   881 
   882 * Antiquotation @{assert} inlines a function bool -> unit that raises
   883 Fail if the argument is false.  Due to inlining the source position of
   884 failed assertions is included in the error output.
   885 
   886 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   887 text is in practice always evaluated with a stable theory checkpoint.
   888 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   889 
   890 * Antiquotation @{theory A} refers to theory A from the ancestry of
   891 the current context, not any accidental theory loader state as before.
   892 Potential INCOMPATIBILITY, subtle change in semantics.
   893 
   894 * Syntax.pretty_priority (default 0) configures the required priority
   895 of pretty-printed output and thus affects insertion of parentheses.
   896 
   897 * Syntax.default_root (default "any") configures the inner syntax
   898 category (nonterminal symbol) for parsing of terms.
   899 
   900 * Former exception Library.UnequalLengths now coincides with
   901 ListPair.UnequalLengths.
   902 
   903 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   904 main functionality is provided by structure Simplifier.
   905 
   906 * Renamed raw "explode" function to "raw_explode" to emphasize its
   907 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   908 almost all situations.
   909 
   910 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   911 See implementation manual for further details on exceptions in
   912 Isabelle/ML.
   913 
   914 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   915 meaning.
   916 
   917 * Renamed structure PureThy to Pure_Thy and moved most of its
   918 operations to structure Global_Theory, to emphasize that this is
   919 rarely-used global-only stuff.
   920 
   921 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   922 instead (or tracing for high-volume output).
   923 
   924 * Configuration option show_question_marks only affects regular pretty
   925 printing of types and terms, not raw Term.string_of_vname.
   926 
   927 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   928 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   929 @{thms} for most purposes.
   930 
   931 * ML structure Unsynchronized is never opened, not even in Isar
   932 interaction mode as before.  Old Unsynchronized.set etc. have been
   933 discontinued -- use plain := instead.  This should be *rare* anyway,
   934 since modern tools always work via official context data, notably
   935 configuration options.
   936 
   937 * Parallel and asynchronous execution requires special care concerning
   938 interrupts.  Structure Exn provides some convenience functions that
   939 avoid working directly with raw Interrupt.  User code must not absorb
   940 interrupts -- intermediate handling (for cleanup etc.) needs to be
   941 followed by re-raising of the original exception.  Another common
   942 source of mistakes are "handle _" patterns, which make the meaning of
   943 the program subject to physical effects of the environment.
   944 
   945 
   946 
   947 New in Isabelle2009-2 (June 2010)
   948 ---------------------------------
   949 
   950 *** General ***
   951 
   952 * Authentic syntax for *all* logical entities (type classes, type
   953 constructors, term constants): provides simple and robust
   954 correspondence between formal entities and concrete syntax.  Within
   955 the parse tree / AST representations, "constants" are decorated by
   956 their category (class, type, const) and spelled out explicitly with
   957 their full internal name.
   958 
   959 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   960 and translations (translation rules and translation functions in ML).
   961 Some hints on upgrading:
   962 
   963   - Many existing uses of 'syntax' and 'translations' can be replaced
   964     by more modern 'type_notation', 'notation' and 'abbreviation',
   965     which are independent of this issue.
   966 
   967   - 'translations' require markup within the AST; the term syntax
   968     provides the following special forms:
   969 
   970       CONST c   -- produces syntax version of constant c from context
   971       XCONST c  -- literally c, checked as constant from context
   972       c         -- literally c, if declared by 'syntax'
   973 
   974     Plain identifiers are treated as AST variables -- occasionally the
   975     system indicates accidental variables via the error "rhs contains
   976     extra variables".
   977 
   978     Type classes and type constructors are marked according to their
   979     concrete syntax.  Some old translations rules need to be written
   980     for the "type" category, using type constructor application
   981     instead of pseudo-term application of the default category
   982     "logic".
   983 
   984   - 'parse_translation' etc. in ML may use the following
   985     antiquotations:
   986 
   987       @{class_syntax c}   -- type class c within parse tree / AST
   988       @{term_syntax c}    -- type constructor c within parse tree / AST
   989       @{const_syntax c}   -- ML version of "CONST c" above
   990       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   991 
   992   - Literal types within 'typed_print_translations', i.e. those *not*
   993     represented as pseudo-terms are represented verbatim.  Use @{class
   994     c} or @{type_name c} here instead of the above syntax
   995     antiquotations.
   996 
   997 Note that old non-authentic syntax was based on unqualified base
   998 names, so all of the above "constant" names would coincide.  Recall
   999 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1000 diagnose syntax problems.
  1001 
  1002 * Type constructors admit general mixfix syntax, not just infix.
  1003 
  1004 * Concrete syntax may be attached to local entities without a proof
  1005 body, too.  This works via regular mixfix annotations for 'fix',
  1006 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1007 similar to the 'notation' command in theory specifications.
  1008 
  1009 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1010 need to specify constant name and syntax separately.  Internal ML
  1011 datatype constructors have been renamed from InfixName to Infix etc.
  1012 Minor INCOMPATIBILITY.
  1013 
  1014 * Schematic theorem statements need to be explicitly markup as such,
  1015 via commands 'schematic_lemma', 'schematic_theorem',
  1016 'schematic_corollary'.  Thus the relevance of the proof is made
  1017 syntactically clear, which impacts performance in a parallel or
  1018 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1019 
  1020 * Use of cumulative prems via "!" in some proof methods has been
  1021 discontinued (old legacy feature).
  1022 
  1023 * References 'trace_simp' and 'debug_simp' have been replaced by
  1024 configuration options stored in the context. Enabling tracing (the
  1025 case of debugging is similar) in proofs works via
  1026 
  1027   using [[trace_simp = true]]
  1028 
  1029 Tracing is then active for all invocations of the simplifier in
  1030 subsequent goal refinement steps. Tracing may also still be enabled or
  1031 disabled via the ProofGeneral settings menu.
  1032 
  1033 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1034 'hide_fact' replace the former 'hide' KIND command.  Minor
  1035 INCOMPATIBILITY.
  1036 
  1037 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1038 more efficient than combinations with -q1 or -q2.
  1039 
  1040 
  1041 *** Pure ***
  1042 
  1043 * Proofterms record type-class reasoning explicitly, using the
  1044 "unconstrain" operation internally.  This eliminates all sort
  1045 constraints from a theorem and proof, introducing explicit
  1046 OFCLASS-premises.  On the proof term level, this operation is
  1047 automatically applied at theorem boundaries, such that closed proofs
  1048 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1049 inspect proof terms.
  1050 
  1051 * Local theory specifications may depend on extra type variables that
  1052 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1053 are added internally.  For example:
  1054 
  1055   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1056 
  1057 * Predicates of locales introduced by classes carry a mandatory
  1058 "class" prefix.  INCOMPATIBILITY.
  1059 
  1060 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1061 
  1062 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1063 'class' instead.
  1064 
  1065 * Command 'code_reflect' allows to incorporate generated ML code into
  1066 runtime environment; replaces immature code_datatype antiquotation.
  1067 INCOMPATIBILITY.
  1068 
  1069 * Code generator: simple concept for abstract datatypes obeying
  1070 invariants.
  1071 
  1072 * Code generator: details of internal data cache have no impact on the
  1073 user space functionality any longer.
  1074 
  1075 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1076 subgoals.  This is more appropriate for interpretations with 'where'.
  1077 INCOMPATIBILITY.
  1078 
  1079 * Command 'example_proof' opens an empty proof body.  This allows to
  1080 experiment with Isar, without producing any persistent result.
  1081 
  1082 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1083 within a local theory context, with explicit checking of the
  1084 constructors involved (in contrast to the raw 'syntax' versions).
  1085 
  1086 * Commands 'types' and 'typedecl' now work within a local theory
  1087 context -- without introducing dependencies on parameters or
  1088 assumptions, which is not possible in Isabelle/Pure.
  1089 
  1090 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1091 within a local theory context.  Minor INCOMPATIBILITY.
  1092 
  1093 
  1094 *** HOL ***
  1095 
  1096 * Command 'typedef' now works within a local theory context -- without
  1097 introducing dependencies on parameters or assumptions, which is not
  1098 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1099 contain multiple interpretations of local typedefs (with different
  1100 non-emptiness proofs), even in a global theory context.
  1101 
  1102 * New package for quotient types.  Commands 'quotient_type' and
  1103 'quotient_definition' may be used for defining types and constants by
  1104 quotient constructions.  An example is the type of integers created by
  1105 quotienting pairs of natural numbers:
  1106 
  1107   fun
  1108     intrel :: "(nat * nat) => (nat * nat) => bool"
  1109   where
  1110     "intrel (x, y) (u, v) = (x + v = u + y)"
  1111 
  1112   quotient_type int = "nat * nat" / intrel
  1113     by (auto simp add: equivp_def expand_fun_eq)
  1114 
  1115   quotient_definition
  1116     "0::int" is "(0::nat, 0::nat)"
  1117 
  1118 The method "lifting" can be used to lift of theorems from the
  1119 underlying "raw" type to the quotient type.  The example
  1120 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1121 construction and provides a reasoning infrastructure for finite sets.
  1122 
  1123 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1124 clash with new theory Quotient in Main HOL.
  1125 
  1126 * Moved the SMT binding into the main HOL session, eliminating
  1127 separate HOL-SMT session.
  1128 
  1129 * List membership infix mem operation is only an input abbreviation.
  1130 INCOMPATIBILITY.
  1131 
  1132 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1133 for future developements; former Library/Word.thy is still present in
  1134 the AFP entry RSAPPS.
  1135 
  1136 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1137 longer shadowed.  INCOMPATIBILITY.
  1138 
  1139 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1140 INCOMPATIBILITY.
  1141 
  1142 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1143 INCOMPATIBILITY.
  1144 
  1145 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1146 instead.  INCOMPATIBILITY.
  1147 
  1148 * Dropped several real-specific versions of lemmas about floor and
  1149 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1150 instead.  INCOMPATIBILITY.
  1151 
  1152   floor_number_of_eq         ~> floor_number_of
  1153   le_floor_eq_number_of      ~> number_of_le_floor
  1154   le_floor_eq_zero           ~> zero_le_floor
  1155   le_floor_eq_one            ~> one_le_floor
  1156   floor_less_eq_number_of    ~> floor_less_number_of
  1157   floor_less_eq_zero         ~> floor_less_zero
  1158   floor_less_eq_one          ~> floor_less_one
  1159   less_floor_eq_number_of    ~> number_of_less_floor
  1160   less_floor_eq_zero         ~> zero_less_floor
  1161   less_floor_eq_one          ~> one_less_floor
  1162   floor_le_eq_number_of      ~> floor_le_number_of
  1163   floor_le_eq_zero           ~> floor_le_zero
  1164   floor_le_eq_one            ~> floor_le_one
  1165   floor_subtract_number_of   ~> floor_diff_number_of
  1166   floor_subtract_one         ~> floor_diff_one
  1167   ceiling_number_of_eq       ~> ceiling_number_of
  1168   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1169   ceiling_le_zero_eq         ~> ceiling_le_zero
  1170   ceiling_le_eq_one          ~> ceiling_le_one
  1171   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1172   less_ceiling_eq_zero       ~> zero_less_ceiling
  1173   less_ceiling_eq_one        ~> one_less_ceiling
  1174   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1175   ceiling_less_eq_zero       ~> ceiling_less_zero
  1176   ceiling_less_eq_one        ~> ceiling_less_one
  1177   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1178   le_ceiling_eq_zero         ~> zero_le_ceiling
  1179   le_ceiling_eq_one          ~> one_le_ceiling
  1180   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1181   ceiling_subtract_one       ~> ceiling_diff_one
  1182 
  1183 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1184 application of the various fold combinators on finite sets.
  1185 
  1186 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1187 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1188 implementation.  INCOMPATIBILTY.
  1189 
  1190 * Theory Library/Coinductive_List has been removed -- superseded by
  1191 AFP/thys/Coinductive.
  1192 
  1193 * Theory PReal, including the type "preal" and related operations, has
  1194 been removed.  INCOMPATIBILITY.
  1195 
  1196 * Real: new development using Cauchy Sequences.
  1197 
  1198 * Split off theory "Big_Operators" containing setsum, setprod,
  1199 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1200 
  1201 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1202 "Int" etc.  INCOMPATIBILITY.
  1203 
  1204 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1205 
  1206 * New set of rules "ac_simps" provides combined assoc / commute
  1207 rewrites for all interpretations of the appropriate generic locales.
  1208 
  1209 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1210 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1211 appropriate and more consistent names suitable for name prefixes
  1212 within the HOL theories.  INCOMPATIBILITY.
  1213 
  1214 * Some generic constants have been put to appropriate theories:
  1215   - less_eq, less: Orderings
  1216   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1217   - inverse, divide: Rings
  1218 INCOMPATIBILITY.
  1219 
  1220 * More consistent naming of type classes involving orderings (and
  1221 lattices):
  1222 
  1223     lower_semilattice                   ~> semilattice_inf
  1224     upper_semilattice                   ~> semilattice_sup
  1225 
  1226     dense_linear_order                  ~> dense_linorder
  1227 
  1228     pordered_ab_group_add               ~> ordered_ab_group_add
  1229     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1230     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1231     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1232     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1233     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1234     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1235     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1236     pordered_comm_ring                  ~> ordered_comm_ring
  1237     pordered_comm_semiring              ~> ordered_comm_semiring
  1238     pordered_ring                       ~> ordered_ring
  1239     pordered_ring_abs                   ~> ordered_ring_abs
  1240     pordered_semiring                   ~> ordered_semiring
  1241 
  1242     ordered_ab_group_add                ~> linordered_ab_group_add
  1243     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1244     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1245     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1246     ordered_field                       ~> linordered_field
  1247     ordered_field_no_lb                 ~> linordered_field_no_lb
  1248     ordered_field_no_ub                 ~> linordered_field_no_ub
  1249     ordered_field_dense_linear_order    ~> dense_linordered_field
  1250     ordered_idom                        ~> linordered_idom
  1251     ordered_ring                        ~> linordered_ring
  1252     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1253     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1254     ordered_ring_strict                 ~> linordered_ring_strict
  1255     ordered_semidom                     ~> linordered_semidom
  1256     ordered_semiring                    ~> linordered_semiring
  1257     ordered_semiring_1                  ~> linordered_semiring_1
  1258     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1259     ordered_semiring_strict             ~> linordered_semiring_strict
  1260 
  1261   The following slightly odd type classes have been moved to a
  1262   separate theory Library/Lattice_Algebras:
  1263 
  1264     lordered_ab_group_add               ~> lattice_ab_group_add
  1265     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1266     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1267     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1268     lordered_ring                       ~> lattice_ring
  1269 
  1270 INCOMPATIBILITY.
  1271 
  1272 * Refined field classes:
  1273   - classes division_ring_inverse_zero, field_inverse_zero,
  1274     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1275     subsumes former division_by_zero class;
  1276   - numerous lemmas have been ported from field to division_ring.
  1277 INCOMPATIBILITY.
  1278 
  1279 * Refined algebra theorem collections:
  1280   - dropped theorem group group_simps, use algebra_simps instead;
  1281   - dropped theorem group ring_simps, use field_simps instead;
  1282   - proper theorem collection field_simps subsumes former theorem
  1283     groups field_eq_simps and field_simps;
  1284   - dropped lemma eq_minus_self_iff which is a duplicate for
  1285     equal_neg_zero.
  1286 INCOMPATIBILITY.
  1287 
  1288 * Theory Finite_Set and List: some lemmas have been generalized from
  1289 sets to lattices:
  1290 
  1291   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1292   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1293   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1294   union_Union_fold_union        ~> sup_Sup_fold_sup
  1295   Inter_fold_inter              ~> Inf_fold_inf
  1296   Union_fold_union              ~> Sup_fold_sup
  1297   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1298   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1299   INTER_fold_inter              ~> INFI_fold_inf
  1300   UNION_fold_union              ~> SUPR_fold_sup
  1301 
  1302 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1303 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1304 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1305 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1306 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1307 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1308 
  1309 * Reorganized theory Multiset: swapped notation of pointwise and
  1310 multiset order:
  1311 
  1312   - pointwise ordering is instance of class order with standard syntax
  1313     <= and <;
  1314   - multiset ordering has syntax <=# and <#; partial order properties
  1315     are provided by means of interpretation with prefix
  1316     multiset_order;
  1317   - less duplication, less historical organization of sections,
  1318     conversion from associations lists to multisets, rudimentary code
  1319     generation;
  1320   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1321     if needed.
  1322 
  1323 Renamed:
  1324 
  1325   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1326   multi_count_ext  ~>  multiset_ext
  1327   diff_union_inverse2  ~>  diff_union_cancelR
  1328 
  1329 INCOMPATIBILITY.
  1330 
  1331 * Theory Permutation: replaced local "remove" by List.remove1.
  1332 
  1333 * Code generation: ML and OCaml code is decorated with signatures.
  1334 
  1335 * Theory List: added transpose.
  1336 
  1337 * Library/Nat_Bijection.thy is a collection of bijective functions
  1338 between nat and other types, which supersedes the older libraries
  1339 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1340 
  1341   Constants:
  1342   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1343   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1344   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1345   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1346   Countable.pair_encode           ~> prod_encode
  1347   NatIso.prod2nat                 ~> prod_encode
  1348   NatIso.nat2prod                 ~> prod_decode
  1349   NatIso.sum2nat                  ~> sum_encode
  1350   NatIso.nat2sum                  ~> sum_decode
  1351   NatIso.list2nat                 ~> list_encode
  1352   NatIso.nat2list                 ~> list_decode
  1353   NatIso.set2nat                  ~> set_encode
  1354   NatIso.nat2set                  ~> set_decode
  1355 
  1356   Lemmas:
  1357   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1358   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1359   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1360   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1361   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1362   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1363   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1364   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1365   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1366   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1367   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1368   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1369   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1370 
  1371 * Sledgehammer:
  1372   - Renamed ATP commands:
  1373     atp_info     ~> sledgehammer running_atps
  1374     atp_kill     ~> sledgehammer kill_atps
  1375     atp_messages ~> sledgehammer messages
  1376     atp_minimize ~> sledgehammer minimize
  1377     print_atps   ~> sledgehammer available_atps
  1378     INCOMPATIBILITY.
  1379   - Added user's manual ("isabelle doc sledgehammer").
  1380   - Added option syntax and "sledgehammer_params" to customize
  1381     Sledgehammer's behavior.  See the manual for details.
  1382   - Modified the Isar proof reconstruction code so that it produces
  1383     direct proofs rather than proofs by contradiction.  (This feature
  1384     is still experimental.)
  1385   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1386     full-typed mode.
  1387   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1388 
  1389 * Nitpick:
  1390   - Added and implemented "binary_ints" and "bits" options.
  1391   - Added "std" option and implemented support for nonstandard models.
  1392   - Added and implemented "finitize" option to improve the precision
  1393     of infinite datatypes based on a monotonicity analysis.
  1394   - Added support for quotient types.
  1395   - Added support for "specification" and "ax_specification"
  1396     constructs.
  1397   - Added support for local definitions (for "function" and
  1398     "termination" proofs).
  1399   - Added support for term postprocessors.
  1400   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1401   - Improved efficiency of "destroy_constrs" optimization.
  1402   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1403     record getters.
  1404   - Fixed soundness bug related to higher-order constructors.
  1405   - Fixed soundness bug when "full_descrs" is enabled.
  1406   - Improved precision of set constructs.
  1407   - Added "atoms" option.
  1408   - Added cache to speed up repeated Kodkod invocations on the same
  1409     problems.
  1410   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1411     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1412     "SAT4J_Light".  INCOMPATIBILITY.
  1413   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1414     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1415   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1416 
  1417 * Method "induct" now takes instantiations of the form t, where t is not
  1418   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1419   If this is not intended, t has to be enclosed in parentheses.
  1420   By default, the equalities generated by definitional instantiations
  1421   are pre-simplified, which may cause parameters of inductive cases
  1422   to disappear, or may even delete some of the inductive cases.
  1423   Use "induct (no_simp)" instead of "induct" to restore the old
  1424   behaviour. The (no_simp) option is also understood by the "cases"
  1425   and "nominal_induct" methods, which now perform pre-simplification, too.
  1426   INCOMPATIBILITY.
  1427 
  1428 
  1429 *** HOLCF ***
  1430 
  1431 * Variable names in lemmas generated by the domain package have
  1432 changed; the naming scheme is now consistent with the HOL datatype
  1433 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1434 
  1435 * The domain package no longer defines the function "foo_copy" for
  1436 recursive domain "foo".  The reach lemma is now stated directly in
  1437 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1438 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1439 
  1440 * Most definedness lemmas generated by the domain package (previously
  1441 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1442 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1443 Proofs that used definedness lemmas as intro rules may break,
  1444 potential INCOMPATIBILITY.
  1445 
  1446 * Induction and casedist rules generated by the domain package now
  1447 declare proper case_names (one called "bottom", and one named for each
  1448 constructor).  INCOMPATIBILITY.
  1449 
  1450 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1451 rules are generated for each domain, INCOMPATIBILITY.
  1452 
  1453   foo_bar.reach       ~> foo.reach  bar.reach
  1454   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1455 
  1456 * Some lemmas generated by the domain package have been renamed for
  1457 consistency with the datatype package, INCOMPATIBILITY.
  1458 
  1459   foo.ind        ~> foo.induct
  1460   foo.finite_ind ~> foo.finite_induct
  1461   foo.coind      ~> foo.coinduct
  1462   foo.casedist   ~> foo.exhaust
  1463   foo.exhaust    ~> foo.nchotomy
  1464 
  1465 * For consistency with other definition packages, the fixrec package
  1466 now generates qualified theorem names, INCOMPATIBILITY.
  1467 
  1468   foo_simps  ~> foo.simps
  1469   foo_unfold ~> foo.unfold
  1470   foo_induct ~> foo.induct
  1471 
  1472 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1473 method and internal fixrec proofs now use the default simpset instead.
  1474 INCOMPATIBILITY.
  1475 
  1476 * The "contlub" predicate has been removed.  Proof scripts should use
  1477 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1478 
  1479 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1480 
  1481 * The constants cpair, cfst, and csnd have been removed in favor of
  1482 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1483 
  1484 
  1485 *** ML ***
  1486 
  1487 * Antiquotations for basic formal entities:
  1488 
  1489     @{class NAME}         -- type class
  1490     @{class_syntax NAME}  -- syntax representation of the above
  1491 
  1492     @{type_name NAME}     -- logical type
  1493     @{type_abbrev NAME}   -- type abbreviation
  1494     @{nonterminal NAME}   -- type of concrete syntactic category
  1495     @{type_syntax NAME}   -- syntax representation of any of the above
  1496 
  1497     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1498     @{const_abbrev NAME}  -- abbreviated constant
  1499     @{const_syntax NAME}  -- syntax representation of any of the above
  1500 
  1501 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1502 syntax constant (cf. 'syntax' command).
  1503 
  1504 * Antiquotation @{make_string} inlines a function to print arbitrary
  1505 values similar to the ML toplevel.  The result is compiler dependent
  1506 and may fall back on "?" in certain situations.
  1507 
  1508 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1509 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1510 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1511 not work with the asynchronous Isar document model.
  1512 
  1513 * Configuration options now admit dynamic default values, depending on
  1514 the context or even global references.
  1515 
  1516 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1517 uses an efficient external library if available (for Poly/ML).
  1518 
  1519 * Renamed some important ML structures, while keeping the old names
  1520 for some time as aliases within the structure Legacy:
  1521 
  1522   OuterKeyword  ~>  Keyword
  1523   OuterLex      ~>  Token
  1524   OuterParse    ~>  Parse
  1525   OuterSyntax   ~>  Outer_Syntax
  1526   PrintMode     ~>  Print_Mode
  1527   SpecParse     ~>  Parse_Spec
  1528   ThyInfo       ~>  Thy_Info
  1529   ThyLoad       ~>  Thy_Load
  1530   ThyOutput     ~>  Thy_Output
  1531   TypeInfer     ~>  Type_Infer
  1532 
  1533 Note that "open Legacy" simplifies porting of sources, but forgetting
  1534 to remove it again will complicate porting again in the future.
  1535 
  1536 * Most operations that refer to a global context are named
  1537 accordingly, e.g. Simplifier.global_context or
  1538 ProofContext.init_global.  There are some situations where a global
  1539 context actually works, but under normal circumstances one needs to
  1540 pass the proper local context through the code!
  1541 
  1542 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1543 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1544 Pretty.pp argument to merge, which is absent in the standard
  1545 Theory_Data version.
  1546 
  1547 * Sorts.certify_sort and derived "cert" operations for types and terms
  1548 no longer minimize sorts.  Thus certification at the boundary of the
  1549 inference kernel becomes invariant under addition of class relations,
  1550 which is an important monotonicity principle.  Sorts are now minimized
  1551 in the syntax layer only, at the boundary between the end-user and the
  1552 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1553 explicitly in rare situations.
  1554 
  1555 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1556 emphasize that this is in no way a standard operation.
  1557 INCOMPATIBILITY.
  1558 
  1559 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1560 usual for resolution.  Rare INCOMPATIBILITY.
  1561 
  1562 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1563 to emphasize that these only work in a global situation (which is
  1564 quite rare).
  1565 
  1566 * Curried take and drop in library.ML; negative length is interpreted
  1567 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1568 
  1569 * Proof terms: type substitutions on proof constants now use canonical
  1570 order of type variables.  INCOMPATIBILITY for tools working with proof
  1571 terms.
  1572 
  1573 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1574 may no longer carry premises.  User-level specifications are
  1575 transformed accordingly by Thm.add_axiom/add_def.
  1576 
  1577 
  1578 *** System ***
  1579 
  1580 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1581 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1582 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1583 
  1584 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1585 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1586 respectively.
  1587 
  1588 * Old lib/scripts/polyml-platform is superseded by the
  1589 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1590 variant, even on a 64 bit machine.  The following example setting
  1591 prefers 64 bit if available:
  1592 
  1593   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1594 
  1595 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1596 Isabelle/Scala layer for advanced prover interaction and integration.
  1597 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1598 component.
  1599 
  1600 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1601 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1602 similar to the default assignment of the document preparation system
  1603 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1604 provides some operations for direct access to the font without asking
  1605 the user for manual installation.
  1606 
  1607 
  1608 
  1609 New in Isabelle2009-1 (December 2009)
  1610 -------------------------------------
  1611 
  1612 *** General ***
  1613 
  1614 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1615 one backslash should be used, even in ML sources.
  1616 
  1617 
  1618 *** Pure ***
  1619 
  1620 * Locale interpretation propagates mixins along the locale hierarchy.
  1621 The currently only available mixins are the equations used to map
  1622 local definitions to terms of the target domain of an interpretation.
  1623 
  1624 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1625 loc" to print all interpretations of locale "loc" in the theory.
  1626 Interpretations in proofs are not shown.
  1627 
  1628 * Thoroughly revised locales tutorial.  New section on conditional
  1629 interpretation.
  1630 
  1631 * On instantiation of classes, remaining undefined class parameters
  1632 are formally declared.  INCOMPATIBILITY.
  1633 
  1634 
  1635 *** Document preparation ***
  1636 
  1637 * New generalized style concept for printing terms: @{foo (style) ...}
  1638 instead of @{foo_style style ...}  (old form is still retained for
  1639 backward compatibility).  Styles can be also applied for
  1640 antiquotations prop, term_type and typeof.
  1641 
  1642 
  1643 *** HOL ***
  1644 
  1645 * New proof method "smt" for a combination of first-order logic with
  1646 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1647 fixed-size bitvectors; there is also basic support for higher-order
  1648 features (esp. lambda abstractions).  It is an incomplete decision
  1649 procedure based on external SMT solvers using the oracle mechanism;
  1650 for the SMT solver Z3, this method is proof-producing.  Certificates
  1651 are provided to avoid calling the external solvers solely for
  1652 re-checking proofs.  Due to a remote SMT service there is no need for
  1653 installing SMT solvers locally.  See src/HOL/SMT.
  1654 
  1655 * New commands to load and prove verification conditions generated by
  1656 the Boogie program verifier or derived systems (e.g. the Verifying C
  1657 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1658 
  1659 * New counterexample generator tool 'nitpick' based on the Kodkod
  1660 relational model finder.  See src/HOL/Tools/Nitpick and
  1661 src/HOL/Nitpick_Examples.
  1662 
  1663 * New commands 'code_pred' and 'values' to invoke the predicate
  1664 compiler and to enumerate values of inductive predicates.
  1665 
  1666 * A tabled implementation of the reflexive transitive closure.
  1667 
  1668 * New implementation of quickcheck uses generic code generator;
  1669 default generators are provided for all suitable HOL types, records
  1670 and datatypes.  Old quickcheck can be re-activated importing theory
  1671 Library/SML_Quickcheck.
  1672 
  1673 * New testing tool Mirabelle for automated proof tools.  Applies
  1674 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1675 every proof step in a theory.  To be used in batch mode via the
  1676 "mirabelle" utility.
  1677 
  1678 * New proof method "sos" (sum of squares) for nonlinear real
  1679 arithmetic (originally due to John Harison). It requires theory
  1680 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1681 works well in practice on quantifier-free real arithmetic with +, -,
  1682 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1683 inequalities between polynomials.  It makes use of external
  1684 semidefinite programming solvers.  Method "sos" generates a
  1685 certificate that can be pasted into the proof thus avoiding the need
  1686 to call an external tool every time the proof is checked.  See
  1687 src/HOL/Library/Sum_Of_Squares.
  1688 
  1689 * New method "linarith" invokes existing linear arithmetic decision
  1690 procedure only.
  1691 
  1692 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1693 
  1694 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1695 Causes full type information to be output to the ATPs.  This slows
  1696 ATPs down considerably but eliminates a source of unsound "proofs"
  1697 that fail later.
  1698 
  1699 * New method "metisFT": A version of metis that uses full type
  1700 information in order to avoid failures of proof reconstruction.
  1701 
  1702 * New evaluator "approximate" approximates an real valued term using
  1703 the same method as the approximation method.
  1704 
  1705 * Method "approximate" now supports arithmetic expressions as
  1706 boundaries of intervals and implements interval splitting and Taylor
  1707 series expansion.
  1708 
  1709 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1710 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1711 
  1712 * New theory SupInf of the supremum and infimum operators for sets of
  1713 reals.
  1714 
  1715 * New theory Probability, which contains a development of measure
  1716 theory, eventually leading to Lebesgue integration and probability.
  1717 
  1718 * Extended Multivariate Analysis to include derivation and Brouwer's
  1719 fixpoint theorem.
  1720 
  1721 * Reorganization of number theory, INCOMPATIBILITY:
  1722   - new number theory development for nat and int, in theories Divides
  1723     and GCD as well as in new session Number_Theory
  1724   - some constants and facts now suffixed with _nat and _int
  1725     accordingly
  1726   - former session NumberTheory now named Old_Number_Theory, including
  1727     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1728   - moved theory Pocklington from src/HOL/Library to
  1729     src/HOL/Old_Number_Theory
  1730 
  1731 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1732 lcm of finite and infinite sets. It is shown that they form a complete
  1733 lattice.
  1734 
  1735 * Class semiring_div requires superclass no_zero_divisors and proof of
  1736 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1737 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1738 generalized to class semiring_div, subsuming former theorems
  1739 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1740 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1741 INCOMPATIBILITY.
  1742 
  1743 * Refinements to lattice classes and sets:
  1744   - less default intro/elim rules in locale variant, more default
  1745     intro/elim rules in class variant: more uniformity
  1746   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1747     le_inf_iff
  1748   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1749     sup_aci)
  1750   - renamed ACI to inf_sup_aci
  1751   - new class "boolean_algebra"
  1752   - class "complete_lattice" moved to separate theory
  1753     "Complete_Lattice"; corresponding constants (and abbreviations)
  1754     renamed and with authentic syntax:
  1755     Set.Inf ~>    Complete_Lattice.Inf
  1756     Set.Sup ~>    Complete_Lattice.Sup
  1757     Set.INFI ~>   Complete_Lattice.INFI
  1758     Set.SUPR ~>   Complete_Lattice.SUPR
  1759     Set.Inter ~>  Complete_Lattice.Inter
  1760     Set.Union ~>  Complete_Lattice.Union
  1761     Set.INTER ~>  Complete_Lattice.INTER
  1762     Set.UNION ~>  Complete_Lattice.UNION
  1763   - authentic syntax for
  1764     Set.Pow
  1765     Set.image
  1766   - mere abbreviations:
  1767     Set.empty               (for bot)
  1768     Set.UNIV                (for top)
  1769     Set.inter               (for inf, formerly Set.Int)
  1770     Set.union               (for sup, formerly Set.Un)
  1771     Complete_Lattice.Inter  (for Inf)
  1772     Complete_Lattice.Union  (for Sup)
  1773     Complete_Lattice.INTER  (for INFI)
  1774     Complete_Lattice.UNION  (for SUPR)
  1775   - object-logic definitions as far as appropriate
  1776 
  1777 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1778 Un_subset_iff are explicitly deleted as default simp rules; then also
  1779 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1780 deleted to achieve the desired effect.
  1781 
  1782 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1783 rules by default any longer; the same applies to min_max.inf_absorb1
  1784 etc.  INCOMPATIBILITY.
  1785 
  1786 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1787 pred_set_conv by default.  INCOMPATIBILITY.
  1788 
  1789 * Power operations on relations and functions are now one dedicated
  1790 constant "compow" with infix syntax "^^".  Power operation on
  1791 multiplicative monoids retains syntax "^" and is now defined generic
  1792 in class power.  INCOMPATIBILITY.
  1793 
  1794 * Relation composition "R O S" now has a more standard argument order:
  1795 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1796 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1797 break, since the O_assoc rule was not rewritten like this.  Fix using
  1798 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1799 
  1800 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1801 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1802 INCOMPATIBILITY.
  1803 
  1804 * Most rules produced by inductive and datatype package have mandatory
  1805 prefixes.  INCOMPATIBILITY.
  1806 
  1807 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1808 the attribute of the same name.  Each of the theorems in the list
  1809 DERIV_intros assumes composition with an additional function and
  1810 matches a variable to the derivative, which has to be solved by the
  1811 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1812 of most elementary terms.  Former Maclauren.DERIV_tac and
  1813 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1814 INCOMPATIBILITY.
  1815 
  1816 * Code generator attributes follow the usual underscore convention:
  1817     code_unfold     replaces    code unfold
  1818     code_post       replaces    code post
  1819     etc.
  1820   INCOMPATIBILITY.
  1821 
  1822 * Renamed methods:
  1823     sizechange -> size_change
  1824     induct_scheme -> induction_schema
  1825   INCOMPATIBILITY.
  1826 
  1827 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1828 INCOMPATIBILITY, use "undefined" directly.
  1829 
  1830 * Renamed theorems:
  1831     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1832     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1833     Suc_plus1 -> Suc_eq_plus1
  1834     *anti_sym -> *antisym*
  1835     vector_less_eq_def -> vector_le_def
  1836   INCOMPATIBILITY.
  1837 
  1838 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1839 INCOMPATIBILITY.
  1840 
  1841 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1842 INCOMPATIBILITY.
  1843 
  1844 
  1845 *** HOLCF ***
  1846 
  1847 * Theory Representable defines a class "rep" of domains that are
  1848 representable (via an ep-pair) in the universal domain type "udom".
  1849 Instances are provided for all type constructors defined in HOLCF.
  1850 
  1851 * The 'new_domain' command is a purely definitional version of the
  1852 domain package, for representable domains.  Syntax is identical to the
  1853 old domain package.  The 'new_domain' package also supports indirect
  1854 recursion using previously-defined type constructors.  See
  1855 src/HOLCF/ex/New_Domain.thy for examples.
  1856 
  1857 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1858 on the left-hand side of an equation, and then performs
  1859 simplification.  Rewriting is done using rules declared with the
  1860 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1861 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1862 
  1863 * The pattern-match compiler in 'fixrec' can now handle constructors
  1864 with HOL function types.  Pattern-match combinators for the Pair
  1865 constructor are pre-configured.
  1866 
  1867 * The 'fixrec' package now produces better fixed-point induction rules
  1868 for mutually-recursive definitions:  Induction rules have conclusions
  1869 of the form "P foo bar" instead of "P <foo, bar>".
  1870 
  1871 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1872 been renamed to "below".  The name "below" now replaces "less" in many
  1873 theorem names.  (Legacy theorem names using "less" are still supported
  1874 as well.)
  1875 
  1876 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1877 patterns can be used to generate strictness rules, or to make
  1878 functions more strict (much like the bang-patterns supported by the
  1879 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1880 examples.
  1881 
  1882 
  1883 *** ML ***
  1884 
  1885 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1886 errors and run-time exceptions, including detailed source positions.
  1887 
  1888 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1889 identified entries, with some additional information such as source
  1890 position, logical grouping etc.
  1891 
  1892 * Theory and context data is now introduced by the simplified and
  1893 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1894 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1895 copy operation) is still available for some time.
  1896 
  1897 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1898 provides a high-level programming interface to synchronized state
  1899 variables with atomic update.  This works via pure function
  1900 application within a critical section -- its runtime should be as
  1901 short as possible; beware of deadlocks if critical code is nested,
  1902 either directly or indirectly via other synchronized variables!
  1903 
  1904 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1905 wraps raw ML references, explicitly indicating their non-thread-safe
  1906 behaviour.  The Isar toplevel keeps this structure open, to
  1907 accommodate Proof General as well as quick and dirty interactive
  1908 experiments with references.
  1909 
  1910 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1911 parallel tactical reasoning.
  1912 
  1913 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1914 are similar to SUBPROOF, but are slightly more flexible: only the
  1915 specified parts of the subgoal are imported into the context, and the
  1916 body tactic may introduce new subgoals and schematic variables.
  1917 
  1918 * Old tactical METAHYPS, which does not observe the proof context, has
  1919 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1920 or Subgoal.FOCUS etc.
  1921 
  1922 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1923 functors have their own ML name space there is no point to mark them
  1924 separately.)  Minor INCOMPATIBILITY.
  1925 
  1926 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1927 
  1928 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1929 INCOMPATIBILITY.
  1930 
  1931 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1932 mode, which avoids critical setmp.
  1933 
  1934 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1935 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1936 Attrib/Method.setup introduced in Isabelle2009.
  1937 
  1938 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1939 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1940 last resort.  INCOMPATIBILITY.
  1941 
  1942 * Display.pretty_thm now requires a proper context (cf. former
  1943 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1944 or even Display.pretty_thm_without_context as last resort.
  1945 INCOMPATIBILITY.
  1946 
  1947 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1948 Syntax.pretty_typ/term directly, preferably with proper context
  1949 instead of global theory.
  1950 
  1951 
  1952 *** System ***
  1953 
  1954 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1955 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1956 usedir option -q.
  1957 
  1958 * Support for additional "Isabelle components" via etc/components, see
  1959 also the system manual.
  1960 
  1961 * The isabelle makeall tool now operates on all components with
  1962 IsaMakefile, not just hardwired "logics".
  1963 
  1964 * Removed "compress" option from isabelle-process and isabelle usedir;
  1965 this is always enabled.
  1966 
  1967 * Discontinued support for Poly/ML 4.x versions.
  1968 
  1969 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1970 on a given logic image.  This requires the lighttpd webserver and is
  1971 currently supported on Linux only.
  1972 
  1973 
  1974 
  1975 New in Isabelle2009 (April 2009)
  1976 --------------------------------
  1977 
  1978 *** General ***
  1979 
  1980 * Simplified main Isabelle executables, with less surprises on
  1981 case-insensitive file-systems (such as Mac OS).
  1982 
  1983   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1984     "isatool."
  1985 
  1986   - The former "isabelle" alias for "isabelle-process" has been
  1987     removed (should rarely occur to regular users).
  1988 
  1989   - The former "isabelle-interface" and its alias "Isabelle" have been
  1990     removed (interfaces are now regular Isabelle tools).
  1991 
  1992 Within scripts and make files, the Isabelle environment variables
  1993 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1994 respectively.  (The latter are still available as legacy feature.)
  1995 
  1996 The old isabelle-interface wrapper could react in confusing ways if
  1997 the interface was uninstalled or changed otherwise.  Individual
  1998 interface tool configuration is now more explicit, see also the
  1999 Isabelle system manual.  In particular, Proof General is now available
  2000 via "isabelle emacs".
  2001 
  2002 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2003 purge installed copies of Isabelle executables and re-run "isabelle
  2004 install -p ...", or use symlinks.
  2005 
  2006 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2007 old ~/isabelle, which was slightly non-standard and apt to cause
  2008 surprises on case-insensitive file-systems (such as Mac OS).
  2009 
  2010 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2011 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2012 care is required when using older releases of Isabelle.  Note that
  2013 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2014 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2015 
  2016 * Proofs of fully specified statements are run in parallel on
  2017 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2018 a regular 4-core machine, if the initial heap space is made reasonably
  2019 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2020 
  2021 * The main reference manuals ("isar-ref", "implementation", and
  2022 "system") have been updated and extended.  Formally checked references
  2023 as hyperlinks are now available uniformly.
  2024 
  2025 
  2026 *** Pure ***
  2027 
  2028 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2029 respects.  The most important changes are listed below.  See the
  2030 Tutorial on Locales ("locales" manual) for details.
  2031 
  2032 - In locale expressions, instantiation replaces renaming.  Parameters
  2033 must be declared in a for clause.  To aid compatibility with previous
  2034 parameter inheritance, in locale declarations, parameters that are not
  2035 'touched' (instantiation position "_" or omitted) are implicitly added
  2036 with their syntax at the beginning of the for clause.
  2037 
  2038 - Syntax from abbreviations and definitions in locales is available in
  2039 locale expressions and context elements.  The latter is particularly
  2040 useful in locale declarations.
  2041 
  2042 - More flexible mechanisms to qualify names generated by locale
  2043 expressions.  Qualifiers (prefixes) may be specified in locale
  2044 expressions, and can be marked as mandatory (syntax: "name!:") or
  2045 optional (syntax "name?:").  The default depends for plain "name:"
  2046 depends on the situation where a locale expression is used: in
  2047 commands 'locale' and 'sublocale' prefixes are optional, in
  2048 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2049 implicit qualifiers derived from the parameter names of a locale are
  2050 no longer generated.
  2051 
  2052 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2053 instantiation clause in "interpretation" and "interpret" (square
  2054 brackets) is no longer available.  Use locale expressions.
  2055 
  2056 - When converting proof scripts, mandatory qualifiers in
  2057 'interpretation' and 'interpret' should be retained by default, even
  2058 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2059 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2060 in locale expressions range over a single locale instance only.
  2061 
  2062 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2063 In existing theorem specifications replace the includes element by the
  2064 respective context elements of the included locale, omitting those
  2065 that are already present in the theorem specification.  Multiple
  2066 assume elements of a locale should be replaced by a single one
  2067 involving the locale predicate.  In the proof body, declarations (most
  2068 notably theorems) may be regained by interpreting the respective
  2069 locales in the proof context as required (command "interpret").
  2070 
  2071 If using "includes" in replacement of a target solely because the
  2072 parameter types in the theorem are not as general as in the target,
  2073 consider declaring a new locale with additional type constraints on
  2074 the parameters (context element "constrains").
  2075 
  2076 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2077 
  2078 - Locale interpretation commands no longer attempt to simplify goal.
  2079 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2080 methods intro_locales and unfold_locales to clarify.
  2081 
  2082 - Locale interpretation commands no longer accept interpretation
  2083 attributes.  INCOMPATIBILITY.
  2084 
  2085 * Class declaration: so-called "base sort" must not be given in import
  2086 list any longer, but is inferred from the specification.  Particularly
  2087 in HOL, write
  2088 
  2089     class foo = ...
  2090 
  2091 instead of
  2092 
  2093     class foo = type + ...
  2094 
  2095 * Class target: global versions of theorems stemming do not carry a
  2096 parameter prefix any longer.  INCOMPATIBILITY.
  2097 
  2098 * Class 'instance' command no longer accepts attached definitions.
  2099 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2100 
  2101 * Recovered hiding of consts, which was accidentally broken in
  2102 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2103 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2104 
  2105 * Slightly more coherent Pure syntax, with updated documentation in
  2106 isar-ref manual.  Removed locales meta_term_syntax and
  2107 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2108 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2109 directly in regular applications.
  2110 
  2111 * There is a new syntactic category "float_const" for signed decimal
  2112 fractions (e.g. 123.45 or -123.45).
  2113 
  2114 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2115 interface with 'setup' command instead.
  2116 
  2117 * Command 'local_setup' is similar to 'setup', but operates on a local
  2118 theory context.
  2119 
  2120 * The 'axiomatization' command now only works within a global theory
  2121 context.  INCOMPATIBILITY.
  2122 
  2123 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2124 hypotheses.  Sorts required in the course of reasoning need to be
  2125 covered by the constraints in the initial statement, completed by the
  2126 type instance information of the background theory.  Non-trivial sort
  2127 hypotheses, which rarely occur in practice, may be specified via
  2128 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2129 
  2130   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2131 
  2132 The result contains an implicit sort hypotheses as before --
  2133 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2134 normalization.
  2135 
  2136 * Generalized Isar history, with support for linear undo, direct state
  2137 addressing etc.
  2138 
  2139 * Changed defaults for unify configuration options:
  2140 
  2141   unify_trace_bound = 50 (formerly 25)
  2142   unify_search_bound = 60 (formerly 30)
  2143 
  2144 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2145 
  2146   a) On theory merge, the last set of code equations for a particular
  2147      constant is taken (in accordance with the policy applied by other
  2148      parts of the code generator framework).
  2149 
  2150   b) Code equations stemming from explicit declarations (e.g. code
  2151      attribute) gain priority over default code equations stemming
  2152      from definition, primrec, fun etc.
  2153 
  2154 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2155 
  2156 * Unified theorem tables for both code generators.  Thus [code
  2157 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2158 
  2159 * Command 'find_consts' searches for constants based on type and name
  2160 patterns, e.g.
  2161 
  2162     find_consts "_ => bool"
  2163 
  2164 By default, matching is against subtypes, but it may be restricted to
  2165 the whole type.  Searching by name is possible.  Multiple queries are
  2166 conjunctive and queries may be negated by prefixing them with a
  2167 hyphen:
  2168 
  2169     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2170 
  2171 * New 'find_theorems' criterion "solves" matches theorems that
  2172 directly solve the current goal (modulo higher-order unification).
  2173 
  2174 * Auto solve feature for main theorem statements: whenever a new goal
  2175 is stated, "find_theorems solves" is called; any theorems that could
  2176 solve the lemma directly are listed as part of the goal state.
  2177 Cf. associated options in Proof General Isabelle settings menu,
  2178 enabled by default, with reasonable timeout for pathological cases of
  2179 higher-order unification.
  2180 
  2181 
  2182 *** Document preparation ***
  2183 
  2184 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2185 demanding keyword 'by' and supporting the full method expression
  2186 syntax just like the Isar command 'by'.
  2187 
  2188 
  2189 *** HOL ***
  2190 
  2191 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2192 points Main and Complex_Main remain as before.
  2193 
  2194 * Logic image HOL-Plain provides a minimal HOL with the most important
  2195 tools available (inductive, datatype, primrec, ...).  This facilitates
  2196 experimentation and tool development.  Note that user applications
  2197 (and library theories) should never refer to anything below theory
  2198 Main, as before.
  2199 
  2200 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2201 experimentation due to shorter build times.
  2202 
  2203 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2204 were previously part of former HOL-Complex.  Entry point Hyperreal
  2205 remains valid, but theories formerly using Complex_Main should now use
  2206 new entry point Hypercomplex.
  2207 
  2208 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2209 Posix processes.  Avoids potentially expensive forking of the ML
  2210 process.  New thread-based implementation also works on non-Unix
  2211 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2212 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2213 commands are covered in the isar-ref manual.
  2214 
  2215 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2216 sledgehammer without local ATP installation (Vampire etc.). Other
  2217 provers may be included via suitable ML wrappers, see also
  2218 src/HOL/ATP_Linkup.thy.
  2219 
  2220 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2221 menu.
  2222 
  2223 * The metis method no longer fails because the theorem is too trivial
  2224 (contains the empty clause).
  2225 
  2226 * The metis method now fails in the usual manner, rather than raising
  2227 an exception, if it determines that it cannot prove the theorem.
  2228 
  2229 * Method "coherent" implements a prover for coherent logic (see also
  2230 src/Tools/coherent.ML).
  2231 
  2232 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2233 "undefined" is the right choice to replace "arbitrary", though
  2234 logically there is no difference.  INCOMPATIBILITY.
  2235 
  2236 * Command "value" now integrates different evaluation mechanisms.  The
  2237 result of the first successful evaluation mechanism is printed.  In
  2238 square brackets a particular named evaluation mechanisms may be
  2239 specified (currently, [SML], [code] or [nbe]).  See further
  2240 src/HOL/ex/Eval_Examples.thy.
  2241 
  2242 * Normalization by evaluation now allows non-leftlinear equations.
  2243 Declare with attribute [code nbe].
  2244 
  2245 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2246 as the structured Isar versions "cases" and "induct", cf. the
  2247 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2248 are now presented as a list of individual projections
  2249 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2250 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2251 rare situations a different rule is selected --- notably nested tuple
  2252 elimination instead of former prod.exhaust: use explicit (case_tac t
  2253 rule: prod.exhaust) here.
  2254 
  2255 * Attributes "cases", "induct", "coinduct" support "del" option.
  2256 
  2257 * Removed fact "case_split_thm", which duplicates "case_split".
  2258 
  2259 * The option datatype has been moved to a new theory Option.  Renamed
  2260 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2261 
  2262 * New predicate "strict_mono" classifies strict functions on partial
  2263 orders.  With strict functions on linear orders, reasoning about
  2264 (in)equalities is facilitated by theorems "strict_mono_eq",
  2265 "strict_mono_less_eq" and "strict_mono_less".
  2266 
  2267 * Some set operations are now proper qualified constants with
  2268 authentic syntax.  INCOMPATIBILITY:
  2269 
  2270     op Int ~>   Set.Int
  2271     op Un ~>    Set.Un
  2272     INTER ~>    Set.INTER
  2273     UNION ~>    Set.UNION
  2274     Inter ~>    Set.Inter
  2275     Union ~>    Set.Union
  2276     {} ~>       Set.empty
  2277     UNIV ~>     Set.UNIV
  2278 
  2279 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2280 theory Set.
  2281 
  2282 * Auxiliary class "itself" has disappeared -- classes without any
  2283 parameter are treated as expected by the 'class' command.
  2284 
  2285 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2286 
  2287 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2288 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2289 
  2290 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2291 method "approximation".  It proves formulas on real values by using
  2292 interval arithmetic.  In the formulas are also the transcendental
  2293 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2294 allowed. For examples see
  2295 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2296 
  2297 * Theory "Reflection" now resides in HOL/Library.
  2298 
  2299 * Entry point to Word library now simply named "Word".
  2300 INCOMPATIBILITY.
  2301 
  2302 * Made source layout more coherent with logical distribution
  2303 structure:
  2304 
  2305     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2306     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2307     src/HOL/Library/GCD.thy ~> src/HOL/
  2308     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2309     src/HOL/Library/Parity.thy ~> src/HOL/
  2310     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2311     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2312     src/HOL/Real/Lubs.thy ~> src/HOL/
  2313     src/HOL/Real/PReal.thy ~> src/HOL/
  2314     src/HOL/Real/Rational.thy ~> src/HOL/
  2315     src/HOL/Real/RComplete.thy ~> src/HOL/
  2316     src/HOL/Real/RealDef.thy ~> src/HOL/
  2317     src/HOL/Real/RealPow.thy ~> src/HOL/
  2318     src/HOL/Real/Real.thy ~> src/HOL/
  2319     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2320     src/HOL/Complex/Complex.thy ~> src/HOL/
  2321     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2322     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2323     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2324     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2325     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2326     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2327     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2328     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2329     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2330     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2331     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2332     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2333     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2334     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2335     src/HOL/Real/Float ~> src/HOL/Library/
  2336     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2337     src/HOL/Real/RealVector.thy ~> src/HOL/
  2338 
  2339     src/HOL/arith_data.ML ~> src/HOL/Tools
  2340     src/HOL/hologic.ML ~> src/HOL/Tools
  2341     src/HOL/simpdata.ML ~> src/HOL/Tools
  2342     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2343     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2344     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2345     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2346     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2347     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2348     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2349 
  2350     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2351     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2352     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2353     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2354     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2355     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2356 
  2357 * If methods "eval" and "evaluation" encounter a structured proof
  2358 state with !!/==>, only the conclusion is evaluated to True (if
  2359 possible), avoiding strange error messages.
  2360 
  2361 * Method "sizechange" automates termination proofs using (a
  2362 modification of) the size-change principle.  Requires SAT solver.  See
  2363 src/HOL/ex/Termination.thy for examples.
  2364 
  2365 * Simplifier: simproc for let expressions now unfolds if bound
  2366 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2367 
  2368 * Method "arith": Linear arithmetic now ignores all inequalities when
  2369 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2370 
  2371 * New attribute "arith" for facts that should always be used
  2372 automatically by arithmetic. It is intended to be used locally in
  2373 proofs, e.g.
  2374 
  2375   assumes [arith]: "x > 0"
  2376 
  2377 Global usage is discouraged because of possible performance impact.
  2378 
  2379 * New classes "top" and "bot" with corresponding operations "top" and
  2380 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2381 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2382 
  2383 * Changed definition lemma "less_fun_def" in order to provide an
  2384 instance for preorders on functions; use lemma "less_le" instead.
  2385 INCOMPATIBILITY.
  2386 
  2387 * Theory Orderings: class "wellorder" moved here, with explicit
  2388 induction rule "less_induct" as assumption.  For instantiation of
  2389 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2390 INCOMPATIBILITY.
  2391 
  2392 * Theory Orderings: added class "preorder" as superclass of "order".
  2393 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2394 etc. slightly changed.  Some theorems named order_class.* now named
  2395 preorder_class.*.
  2396 
  2397 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2398 "diag" to "Id_on".
  2399 
  2400 * Theory Finite_Set: added a new fold combinator of type
  2401 
  2402   ('a => 'b => 'b) => 'b => 'a set => 'b
  2403 
  2404 Occasionally this is more convenient than the old fold combinator
  2405 which is now defined in terms of the new one and renamed to
  2406 fold_image.
  2407 
  2408 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2409 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2410 extended with further lemmas!).  At the moment both still exist but
  2411 the former will disappear at some point.
  2412 
  2413 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2414 class recpower.  Type-specific simp rules for various recpower types
  2415 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2416 
  2417 rat_power_0    -> power_0
  2418 rat_power_Suc  -> power_Suc
  2419 realpow_0      -> power_0
  2420 realpow_Suc    -> power_Suc
  2421 complexpow_0   -> power_0
  2422 complexpow_Suc -> power_Suc
  2423 power_poly_0   -> power_0
  2424 power_poly_Suc -> power_Suc
  2425 
  2426 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2427 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2428 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2429 of lemmas from Divides has been generalized from nat to class
  2430 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2431 renames resulting from duplicate elimination:
  2432 
  2433     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2434     zero_dvd_iff ~>         dvd_0_left_iff
  2435     dvd_0 ~>                dvd_0_right
  2436     DIVISION_BY_ZERO_DIV ~> div_by_0
  2437     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2438     mult_div ~>             div_mult_self2_is_id
  2439     mult_mod ~>             mod_mult_self2_is_0
  2440 
  2441 * Theory IntDiv: removed many lemmas that are instances of class-based
  2442 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2443 rename old lemmas as follows:
  2444 
  2445 dvd_diff               -> nat_dvd_diff
  2446 dvd_zminus_iff         -> dvd_minus_iff
  2447 mod_add1_eq            -> mod_add_eq
  2448 mod_mult1_eq           -> mod_mult_right_eq
  2449 mod_mult1_eq'          -> mod_mult_left_eq
  2450 mod_mult_distrib_mod   -> mod_mult_eq
  2451 nat_mod_add_left_eq    -> mod_add_left_eq
  2452 nat_mod_add_right_eq   -> mod_add_right_eq
  2453 nat_mod_div_trivial    -> mod_div_trivial
  2454 nat_mod_mod_trivial    -> mod_mod_trivial
  2455 zdiv_zadd_self1        -> div_add_self1
  2456 zdiv_zadd_self2        -> div_add_self2
  2457 zdiv_zmult_self1       -> div_mult_self2_is_id
  2458 zdiv_zmult_self2       -> div_mult_self1_is_id
  2459 zdvd_triv_left         -> dvd_triv_left
  2460 zdvd_triv_right        -> dvd_triv_right
  2461 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2462 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2463 zmod_zadd_left_eq      -> mod_add_left_eq
  2464 zmod_zadd_right_eq     -> mod_add_right_eq
  2465 zmod_zadd_self1        -> mod_add_self1
  2466 zmod_zadd_self2        -> mod_add_self2
  2467 zmod_zadd1_eq          -> mod_add_eq
  2468 zmod_zdiff1_eq         -> mod_diff_eq
  2469 zmod_zdvd_zmod         -> mod_mod_cancel
  2470 zmod_zmod_cancel       -> mod_mod_cancel
  2471 zmod_zmult_self1       -> mod_mult_self2_is_0
  2472 zmod_zmult_self2       -> mod_mult_self1_is_0
  2473 zmod_1                 -> mod_by_1
  2474 zdiv_1                 -> div_by_1
  2475 zdvd_abs1              -> abs_dvd_iff
  2476 zdvd_abs2              -> dvd_abs_iff
  2477 zdvd_refl              -> dvd_refl
  2478 zdvd_trans             -> dvd_trans
  2479 zdvd_zadd              -> dvd_add
  2480 zdvd_zdiff             -> dvd_diff
  2481 zdvd_zminus_iff        -> dvd_minus_iff
  2482 zdvd_zminus2_iff       -> minus_dvd_iff
  2483 zdvd_zmultD            -> dvd_mult_right
  2484 zdvd_zmultD2           -> dvd_mult_left
  2485 zdvd_zmult_mono        -> mult_dvd_mono
  2486 zdvd_0_right           -> dvd_0_right
  2487 zdvd_0_left            -> dvd_0_left_iff
  2488 zdvd_1_left            -> one_dvd
  2489 zminus_dvd_iff         -> minus_dvd_iff
  2490 
  2491 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2492 
  2493 * The real numbers offer decimal input syntax: 12.34 is translated
  2494 into 1234/10^2. This translation is not reversed upon output.
  2495 
  2496 * Theory Library/Polynomial defines an abstract type 'a poly of
  2497 univariate polynomials with coefficients of type 'a.  In addition to
  2498 the standard ring operations, it also supports div and mod.  Code
  2499 generation is also supported, using list-style constructors.
  2500 
  2501 * Theory Library/Inner_Product defines a class of real_inner for real
  2502 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2503 => real.  Class real_inner is a subclass of real_normed_vector from
  2504 theory RealVector.
  2505 
  2506 * Theory Library/Product_Vector provides instances for the product
  2507 type 'a * 'b of several classes from RealVector and Inner_Product.
  2508 Definitions of addition, subtraction, scalar multiplication, norms,
  2509 and inner products are included.
  2510 
  2511 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2512 addition to the field operations, numerals and case syntax are also
  2513 supported.
  2514 
  2515 * Theory Library/Diagonalize provides constructive version of Cantor's
  2516 first diagonalization argument.
  2517 
  2518 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2519 zlcm (for int); carried together from various gcd/lcm developements in
  2520 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2521 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2522 may recover tupled syntax as follows:
  2523 
  2524     hide (open) const gcd
  2525     abbreviation gcd where
  2526       "gcd == (%(a, b). GCD.gcd a b)"
  2527     notation (output)
  2528       GCD.gcd ("gcd '(_, _')")
  2529 
  2530 The same works for lcm, zgcd, zlcm.
  2531 
  2532 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2533 instantiations for algebraic structures.  Removed some duplicate
  2534 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2535 
  2536 * ML antiquotation @{code} takes a constant as argument and generates
  2537 corresponding code in background and inserts name of the corresponding
  2538 resulting ML value/function/datatype constructor binding in place.
  2539 All occurrences of @{code} with a single ML block are generated
  2540 simultaneously.  Provides a generic and safe interface for
  2541 instrumentalizing code generation.  See
  2542 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2543 In future you ought to refrain from ad-hoc compiling generated SML
  2544 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2545 cannot refer to constants for which user-defined serializations are
  2546 set.  Refer to the corresponding ML counterpart directly in that
  2547 cases.
  2548 
  2549 * Command 'rep_datatype': instead of theorem names the command now
  2550 takes a list of terms denoting the constructors of the type to be
  2551 represented as datatype.  The characteristic theorems have to be
  2552 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2553 have disappeared in favour of existing ones:
  2554 
  2555     unit_induct                 ~> unit.induct
  2556     prod_induct                 ~> prod.induct
  2557     sum_induct                  ~> sum.induct
  2558     Suc_Suc_eq                  ~> nat.inject
  2559     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2560 
  2561 
  2562 *** HOL-Algebra ***
  2563 
  2564 * New locales for orders and lattices where the equivalence relation
  2565 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2566 locales use a record structure with field eq for the equivalence.
  2567 
  2568 * New theory of factorial domains.
  2569 
  2570 * Units_l_inv and Units_r_inv are now simp rules by default.
  2571 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2572 and/or r_inv will now also require deletion of these lemmas.
  2573 
  2574 * Renamed the following theorems, INCOMPATIBILITY:
  2575 
  2576 UpperD ~> Upper_memD
  2577 LowerD ~> Lower_memD
  2578 least_carrier ~> least_closed
  2579 greatest_carrier ~> greatest_closed
  2580 greatest_Lower_above ~> greatest_Lower_below
  2581 one_zero ~> carrier_one_zero
  2582 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2583 
  2584 
  2585 *** HOL-Nominal ***
  2586 
  2587 * Nominal datatypes can now contain type-variables.
  2588 
  2589 * Commands 'nominal_inductive' and 'equivariance' work with local
  2590 theory targets.
  2591 
  2592 * Nominal primrec can now works with local theory targets and its
  2593 specification syntax now conforms to the general format as seen in
  2594 'inductive' etc.
  2595 
  2596 * Method "perm_simp" honours the standard simplifier attributes
  2597 (no_asm), (no_asm_use) etc.
  2598 
  2599 * The new predicate #* is defined like freshness, except that on the
  2600 left hand side can be a set or list of atoms.
  2601 
  2602 * Experimental command 'nominal_inductive2' derives strong induction
  2603 principles for inductive definitions.  In contrast to
  2604 'nominal_inductive', which can only deal with a fixed number of
  2605 binders, it can deal with arbitrary expressions standing for sets of
  2606 atoms to be avoided.  The only inductive definition we have at the
  2607 moment that needs this generalisation is the typing rule for Lets in
  2608 the algorithm W:
  2609 
  2610  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2611  -----------------------------------------------------------------
  2612          Gamma |- Let x be t1 in t2 : T2
  2613 
  2614 In this rule one wants to avoid all the binders that are introduced by
  2615 "close Gamma T1".  We are looking for other examples where this
  2616 feature might be useful.  Please let us know.
  2617 
  2618 
  2619 *** HOLCF ***
  2620 
  2621 * Reimplemented the simplification procedure for proving continuity
  2622 subgoals.  The new simproc is extensible; users can declare additional
  2623 continuity introduction rules with the attribute [cont2cont].
  2624 
  2625 * The continuity simproc now uses a different introduction rule for
  2626 solving continuity subgoals on terms with lambda abstractions.  In
  2627 some rare cases the new simproc may fail to solve subgoals that the
  2628 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2629 Potential INCOMPATIBILITY.
  2630 
  2631 * Command 'fixrec': specification syntax now conforms to the general
  2632 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2633 examples.  INCOMPATIBILITY.
  2634 
  2635 
  2636 *** ZF ***
  2637 
  2638 * Proof of Zorn's Lemma for partial orders.
  2639 
  2640 
  2641 *** ML ***
  2642 
  2643 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2644 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2645 depends on multithreading, so timouts will not work before Poly/ML
  2646 5.2.1!
  2647 
  2648 * High-level support for concurrent ML programming, see
  2649 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2650 particularly convenient to organize independent functional
  2651 computations.  The concept of "synchronized variables" provides a
  2652 higher-order interface for components with shared state, avoiding the
  2653 delicate details of mutexes and condition variables.  (Requires
  2654 Poly/ML 5.2.1 or later.)
  2655 
  2656 * ML bindings produced via Isar commands are stored within the Isar
  2657 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2658 become thread-safe and work with undo as expected (concerning
  2659 top-level bindings, not side-effects on global references).
  2660 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2661 compiler at runtime; really global bindings need to be given outside a
  2662 theory.  (Requires Poly/ML 5.2 or later.)
  2663 
  2664 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2665 context.  Top-level ML bindings are stored within the proof context in
  2666 a purely sequential fashion, disregarding the nested proof structure.
  2667 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2668 proof.  (Requires Poly/ML 5.2 or later.)
  2669 
  2670 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2671 and Method.setup, as well as Isar commands 'attribute_setup' and
  2672 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2673 existing code accordingly, or use plain 'setup' together with old
  2674 Method.add_method.
  2675 
  2676 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2677 to 'a -> thm, while results are always tagged with an authentic oracle
  2678 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2679 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2680 accordingly.  Note that extra performance may be gained by producing
  2681 the cterm carefully, avoiding slow Thm.cterm_of.
  2682 
  2683 * Simplified interface for defining document antiquotations via
  2684 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2685 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2686 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2687 examples.
  2688 
  2689 * More systematic treatment of long names, abstract name bindings, and
  2690 name space operations.  Basic operations on qualified names have been
  2691 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2692 Long_Name.append.  Old type bstring has been mostly replaced by
  2693 abstract type binding (see structure Binding), which supports precise
  2694 qualification by packages and local theory targets, as well as proper
  2695 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2696 bstring values into Binding.name, or better pass through abstract
  2697 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2698 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2699 
  2700 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2701 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2702 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2703 
  2704 * Disposed old type and term read functions (Sign.read_def_typ,
  2705 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2706 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2707 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2708 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2709 resort for legacy applications.
  2710 
  2711 * Disposed old declarations, tactics, tactic combinators that refer to
  2712 the simpset or claset of an implicit theory (such as Addsimps,
  2713 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2714 embedded ML text, or local_simpset_of with a proper context passed as
  2715 explicit runtime argument.
  2716 
  2717 * Rules and tactics that read instantiations (read_instantiate,
  2718 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2719 context, which is required for parsing and type-checking.  Moreover,
  2720 the variables are specified as plain indexnames, not string encodings
  2721 thereof.  INCOMPATIBILITY.
  2722 
  2723 * Generic Toplevel.add_hook interface allows to analyze the result of
  2724 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2725 for theorem dependency output of transactions resulting in a new
  2726 theory state.
  2727 
  2728 * ML antiquotations: block-structured compilation context indicated by
  2729 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2730 
  2731   @{binding name}                         - basic name binding
  2732   @{let ?pat = term}                      - term abbreviation (HO matching)
  2733   @{note name = fact}                     - fact abbreviation
  2734   @{thm fact}                             - singleton fact (with attributes)
  2735   @{thms fact}                            - general fact (with attributes)
  2736   @{lemma prop by method}                 - singleton goal
  2737   @{lemma prop by meth1 meth2}            - singleton goal
  2738   @{lemma prop1 ... propN by method}      - general goal
  2739   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2740   @{lemma (open) ...}                     - open derivation
  2741 
  2742 
  2743 *** System ***
  2744 
  2745 * The Isabelle "emacs" tool provides a specific interface to invoke
  2746 Proof General / Emacs, with more explicit failure if that is not
  2747 installed (the old isabelle-interface script silently falls back on
  2748 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2749 installation location of the Proof General distribution.
  2750 
  2751 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2752 the Isabelle process into a JVM/Scala application.  See
  2753 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2754 process wrapper has been discontinued.)
  2755 
  2756 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2757 
  2758 * Various status messages (with exact source position information) are
  2759 emitted, if proper markup print mode is enabled.  This allows
  2760 user-interface components to provide detailed feedback on internal
  2761 prover operations.
  2762 
  2763 
  2764 
  2765 New in Isabelle2008 (June 2008)
  2766 -------------------------------
  2767 
  2768 *** General ***
  2769 
  2770 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2771 and updated, with formally checked references as hyperlinks.
  2772 
  2773 * Theory loader: use_thy (and similar operations) no longer set the
  2774 implicit ML context, which was occasionally hard to predict and in
  2775 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2776 provides a proper context already.
  2777 
  2778 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2779 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2780 'use' within a theory file will do the job.
  2781 
  2782 * Name space merge now observes canonical order, i.e. the second space
  2783 is inserted into the first one, while existing entries in the first
  2784 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2785 swap theory imports.
  2786 
  2787 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2788 INCOMPATIBILITY in identifier syntax etc.
  2789 
  2790 * Outer syntax: string tokens no longer admit escaped white space,
  2791 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2792 white space without escapes.
  2793 
  2794 * Outer syntax: string tokens may contain arbitrary character codes
  2795 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2796 "foo_bar".
  2797 
  2798 
  2799 *** Pure ***
  2800 
  2801 * Context-dependent token translations.  Default setup reverts locally
  2802 fixed variables, and adds hilite markup for undeclared frees.
  2803 
  2804 * Unused theorems can be found using the new command 'unused_thms'.
  2805 There are three ways of invoking it:
  2806 
  2807 (1) unused_thms
  2808      Only finds unused theorems in the current theory.
  2809 
  2810 (2) unused_thms thy_1 ... thy_n -
  2811      Finds unused theorems in the current theory and all of its ancestors,
  2812      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2813 
  2814 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2815      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2816      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2817      their ancestors.
  2818 
  2819 In order to increase the readability of the list produced by
  2820 unused_thms, theorems that have been created by a particular instance
  2821 of a theory command such as 'inductive' or 'function' are considered
  2822 to belong to the same "group", meaning that if at least one theorem in
  2823 this group is used, the other theorems in the same group are no longer
  2824 reported as unused.  Moreover, if all theorems in the group are
  2825 unused, only one theorem in the group is displayed.
  2826 
  2827 Note that proof objects have to be switched on in order for
  2828 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2829 usually the case when using Proof General with the default settings).
  2830 
  2831 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2832 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2833 duplicate fact bindings, or even accidental fact duplications.  Note
  2834 that tools may maintain dynamically scoped facts systematically, using
  2835 PureThy.add_thms_dynamic.
  2836 
  2837 * Command 'hide' now allows to hide from "fact" name space as well.
  2838 
  2839 * Eliminated destructive theorem database, simpset, claset, and
  2840 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2841 update of theories within ML code.
  2842 
  2843 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2844 INCOMPATIBILITY, object-logics depending on former Pure require
  2845 additional setup PureThy.old_appl_syntax_setup; object-logics
  2846 depending on former CPure need to refer to Pure.
  2847 
  2848 * Commands 'use' and 'ML' are now purely functional, operating on
  2849 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2850 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2851 INCOMPATIBILITY.
  2852 
  2853 * Command 'setup': discontinued implicit version with ML reference.
  2854 
  2855 * Instantiation target allows for simultaneous specification of class
  2856 instance operations together with an instantiation proof.
  2857 Type-checking phase allows to refer to class operations uniformly.
  2858 See src/HOL/Complex/Complex.thy for an Isar example and
  2859 src/HOL/Library/Eval.thy for an ML example.
  2860 
  2861 * Indexing of literal facts: be more serious about including only
  2862 facts from the visible specification/proof context, but not the
  2863 background context (locale etc.).  Affects `prop` notation and method
  2864 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2865 situations.
  2866 
  2867 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2868 "(open)" option, which used to expose internal bound variables to the
  2869 proof text.
  2870 
  2871 * Isar statements: removed obsolete case "rule_context".
  2872 INCOMPATIBILITY, better use explicit fixes/assumes.
  2873 
  2874 * Locale proofs: default proof step now includes 'unfold_locales';
  2875 hence 'proof' without argument may be used to unfold locale
  2876 predicates.
  2877 
  2878 
  2879 *** Document preparation ***
  2880 
  2881 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2882 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2883 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2884 spot); renamed link color from "darkblue" to "linkcolor" (default
  2885 value unchanged, can be redefined via \definecolor); no longer sets
  2886 "a4paper" option (unnecessary or even intrusive).
  2887 
  2888 * Antiquotation @{lemma A method} proves proposition A by the given
  2889 method (either a method name or a method name plus (optional) method
  2890 arguments in parentheses) and prints A just like @{prop A}.
  2891 
  2892 
  2893 *** HOL ***
  2894 
  2895 * New primrec package.  Specification syntax conforms in style to
  2896 definition/function/....  No separate induction rule is provided.  The
  2897 "primrec" command distinguishes old-style and new-style specifications
  2898 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2899 When adjusting theories, beware: constants stemming from new-style
  2900 primrec specifications have authentic syntax.
  2901 
  2902 * Metis prover is now an order of magnitude faster, and also works
  2903 with multithreading.
  2904 
  2905 * Metis: the maximum number of clauses that can be produced from a
  2906 theorem is now given by the attribute max_clauses.  Theorems that
  2907 exceed this number are ignored, with a warning printed.
  2908 
  2909 * Sledgehammer no longer produces structured proofs by default. To
  2910 enable, declare [[sledgehammer_full = true]].  Attributes
  2911 reconstruction_modulus, reconstruction_sorts renamed
  2912 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2913 
  2914 * Method "induct_scheme" derives user-specified induction rules
  2915 from well-founded induction and completeness of patterns. This factors
  2916 out some operations that are done internally by the function package
  2917 and makes them available separately.  See
  2918 src/HOL/ex/Induction_Scheme.thy for examples.
  2919 
  2920 * More flexible generation of measure functions for termination
  2921 proofs: Measure functions can be declared by proving a rule of the
  2922 form "is_measure f" and giving it the [measure_function] attribute.
  2923 The "is_measure" predicate is logically meaningless (always true), and
  2924 just guides the heuristic.  To find suitable measure functions, the
  2925 termination prover sets up the goal "is_measure ?f" of the appropriate
  2926 type and generates all solutions by prolog-style backwards proof using
  2927 the declared rules.
  2928 
  2929 This setup also deals with rules like 
  2930 
  2931   "is_measure f ==> is_measure (list_size f)"
  2932 
  2933 which accommodates nested datatypes that recurse through lists.
  2934 Similar rules are predeclared for products and option types.
  2935 
  2936 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2937 
  2938   INCOMPATIBILITIES:
  2939 
  2940   - Definitions of overloaded constants on sets have to be replaced by
  2941     definitions on => and bool.
  2942 
  2943   - Some definitions of overloaded operators on sets can now be proved
  2944     using the definitions of the operators on => and bool.  Therefore,
  2945     the following theorems have been renamed:
  2946 
  2947       subset_def   -> subset_eq
  2948       psubset_def  -> psubset_eq
  2949       set_diff_def -> set_diff_eq
  2950       Compl_def    -> Compl_eq
  2951       Sup_set_def  -> Sup_set_eq
  2952       Inf_set_def  -> Inf_set_eq
  2953       sup_set_def  -> sup_set_eq
  2954       inf_set_def  -> inf_set_eq
  2955 
  2956   - Due to the incompleteness of the HO unification algorithm, some
  2957     rules such as subst may require manual instantiation, if some of
  2958     the unknowns in the rule is a set.
  2959 
  2960   - Higher order unification and forward proofs:
  2961     The proof pattern
  2962 
  2963       have "P (S::'a set)" <...>
  2964       then have "EX S. P S" ..
  2965 
  2966     no longer works (due to the incompleteness of the HO unification
  2967     algorithm) and must be replaced by the pattern
  2968 
  2969       have "EX S. P S"
  2970       proof
  2971         show "P S" <...>
  2972       qed
  2973 
  2974   - Calculational reasoning with subst (or similar rules):
  2975     The proof pattern
  2976 
  2977       have "P (S::'a set)" <...>
  2978       also have "S = T" <...>
  2979       finally have "P T" .
  2980 
  2981     no longer works (for similar reasons as the previous example) and
  2982     must be replaced by something like
  2983 
  2984       have "P (S::'a set)" <...>
  2985       moreover have "S = T" <...>
  2986       ultimately have "P T" by simp
  2987 
  2988   - Tactics or packages written in ML code:
  2989     Code performing pattern matching on types via
  2990 
  2991       Type ("set", [T]) => ...
  2992 
  2993     must be rewritten. Moreover, functions like strip_type or
  2994     binder_types no longer return the right value when applied to a
  2995     type of the form
  2996 
  2997       T1 => ... => Tn => U => bool
  2998 
  2999     rather than
  3000 
  3001       T1 => ... => Tn => U set
  3002 
  3003 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3004 Wellfounded_Relations to theory Wellfounded.
  3005 
  3006 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3007 
  3008 * Class finite no longer treats UNIV as class parameter.  Use class
  3009 enum from theory Library/Enum instead to achieve a similar effect.
  3010 INCOMPATIBILITY.
  3011 
  3012 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3013 and "Cons".  INCOMPATIBILITY.
  3014 
  3015 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3016 Potential INCOMPATIBILITY.
  3017 
  3018 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3019 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3020 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3021 
  3022 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3023 the same name in theory Orderings:
  3024 
  3025   less_trans
  3026   less_linear
  3027   le_imp_less_or_eq
  3028   le_less_trans
  3029   less_le_trans
  3030   less_not_sym
  3031   less_asym
  3032 
  3033 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3034 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3035 and different variable names.
  3036 
  3037 * Library/Option_ord.thy: Canonical order on option type.
  3038 
  3039 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3040 finite maps.
  3041 
  3042 * Library/Countable.thy: Type class for countable types.
  3043 
  3044 * Theory Int: The representation of numerals has changed.  The infix
  3045 operator BIT and the bit datatype with constructors B0 and B1 have
  3046 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3047 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3048 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3049 accordingly.
  3050 
  3051 * Theory Nat: definition of <= and < on natural numbers no longer
  3052 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3053 le_def and less_def have disappeared.  Consider lemmas not_less
  3054 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3055 
  3056 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3057 (whose purpose mainly is for various fold_set functionals) have been
  3058 abandoned in favor of the existing algebraic classes
  3059 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3060 lower_semilattice (resp. upper_semilattice) and linorder.
  3061 INCOMPATIBILITY.
  3062 
  3063 * Theory Transitive_Closure: induct and cases rules now declare proper
  3064 case_names ("base" and "step").  INCOMPATIBILITY.
  3065 
  3066 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3067 lattices.  The form set-specific version is available as
  3068 Inductive.lfp_ordinal_induct_set.
  3069 
  3070 * Renamed theorems "power.simps" to "power_int.simps".
  3071 INCOMPATIBILITY.
  3072 
  3073 * Class semiring_div provides basic abstract properties of semirings
  3074 with division and modulo operations.  Subsumes former class dvd_mod.
  3075 
  3076 * Merged theories IntDef, Numeral and IntArith into unified theory
  3077 Int.  INCOMPATIBILITY.
  3078 
  3079 * Theory Library/Code_Index: type "index" now represents natural
  3080 numbers rather than integers.  INCOMPATIBILITY.
  3081 
  3082 * New class "uminus" with operation "uminus" (split of from class
  3083 "minus" which now only has operation "minus", binary).
  3084 INCOMPATIBILITY.
  3085 
  3086 * Constants "card", "internal_split", "option_map" now with authentic
  3087 syntax.  INCOMPATIBILITY.
  3088 
  3089 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3090 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3091 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3092 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3093 Sup_set_def, le_def, less_def, option_map_def now with object
  3094 equality.  INCOMPATIBILITY.
  3095 
  3096 * Records. Removed K_record, and replaced it by pure lambda term
  3097 %x. c. The simplifier setup is now more robust against eta expansion.
  3098 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3099 
  3100 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3101 
  3102 * Library/ListVector: new theory of arithmetic vector operations.
  3103 
  3104 * Library/Order_Relation: new theory of various orderings as sets of
  3105 pairs.  Defines preorders, partial orders, linear orders and
  3106 well-orders on sets and on types.
  3107 
  3108 
  3109 *** ZF ***
  3110 
  3111 * Renamed some theories to allow to loading both ZF and HOL in the
  3112 same session:
  3113 
  3114   Datatype  -> Datatype_ZF
  3115   Inductive -> Inductive_ZF
  3116   Int       -> Int_ZF
  3117   IntDiv    -> IntDiv_ZF
  3118   Nat       -> Nat_ZF
  3119   List      -> List_ZF
  3120   Main      -> Main_ZF
  3121 
  3122 INCOMPATIBILITY: ZF theories that import individual theories below
  3123 Main might need to be adapted.  Regular theory Main is still
  3124 available, as trivial extension of Main_ZF.
  3125 
  3126 
  3127 *** ML ***
  3128 
  3129 * ML within Isar: antiquotation @{const name} or @{const
  3130 name(typargs)} produces statically-checked Const term.
  3131 
  3132 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3133 (of the same name).  Removed obsolete print command.
  3134 
  3135 * Removed obsolete "use_legacy_bindings" function.
  3136 
  3137 * The ``print mode'' is now a thread-local value derived from a global
  3138 template (the former print_mode reference), thus access becomes
  3139 non-critical.  The global print_mode reference is for session
  3140 management only; user-code should use print_mode_value,
  3141 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3142 
  3143 * Functions system/system_out provide a robust way to invoke external
  3144 shell commands, with propagation of interrupts (requires Poly/ML
  3145 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3146 
  3147 
  3148 *** System ***
  3149 
  3150 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3151 in accordance with Proof General 3.7, which prefers GNU emacs.
  3152 
  3153 * isatool tty runs Isabelle process with plain tty interaction;
  3154 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3155 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3156 
  3157 * isatool browser now works with Cygwin as well, using general
  3158 "javapath" function defined in Isabelle process environment.
  3159 
  3160 * YXML notation provides a simple and efficient alternative to
  3161 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3162 isatool yxml as described in the Isabelle system manual.
  3163 
  3164 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3165 provides general wrapper for managing an Isabelle process in a robust
  3166 fashion, with ``cooked'' output from stdin/stderr.
  3167 
  3168 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3169 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3170 
  3171 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3172 way of changing the user's settings is via
  3173 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3174 script.
  3175 
  3176 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3177 cores of the underlying machine, which is a good starting point for
  3178 optimal performance tuning.  The corresponding usedir option -M allows
  3179 "max" as an alias for "0".  WARNING: does not work on certain versions
  3180 of Mac OS (with Poly/ML 5.1).
  3181 
  3182 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3183 adverse effect of Isabelle flooding interactive front-ends (notably
  3184 ProofGeneral / XEmacs).
  3185 
  3186 
  3187 
  3188 New in Isabelle2007 (November 2007)
  3189 -----------------------------------
  3190 
  3191 *** General ***
  3192 
  3193 * More uniform information about legacy features, notably a
  3194 warning/error of "Legacy feature: ...", depending on the state of the
  3195 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3196 legacy features will disappear eventually.
  3197 
  3198 * Theory syntax: the header format ``theory A = B + C:'' has been
  3199 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3200 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3201 
  3202 * Theory syntax: the old non-Isar theory file format has been
  3203 discontinued altogether.  Note that ML proof scripts may still be used
  3204 with Isar theories; migration is usually quite simple with the ML
  3205 function use_legacy_bindings.  INCOMPATIBILITY.
  3206 
  3207 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3208 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3209 quotes.
  3210 
  3211 * Theory loader: be more serious about observing the static theory
  3212 header specifications (including optional directories), but not the
  3213 accidental file locations of previously successful loads.  The strict
  3214 update policy of former update_thy is now already performed by
  3215 use_thy, so the former has been removed; use_thys updates several
  3216 theories simultaneously, just as 'imports' within a theory header
  3217 specification, but without merging the results.  Potential
  3218 INCOMPATIBILITY: may need to refine theory headers and commands
  3219 ROOT.ML which depend on load order.
  3220 
  3221 * Theory loader: optional support for content-based file
  3222 identification, instead of the traditional scheme of full physical
  3223 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3224 (cf. the system manual).  The new scheme allows to work with
  3225 non-finished theories in persistent session images, such that source
  3226 files may be moved later on without requiring reloads.
  3227 
  3228 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3229 file (with the same base name as the theory) are considered a legacy
  3230 feature, which will disappear eventually. Even now, the theory loader
  3231 no longer maintains dependencies on such files.
  3232 
  3233 * Syntax: the scope for resolving ambiguities via type-inference is
  3234 now limited to individual terms, instead of whole simultaneous
  3235 specifications as before. This greatly reduces the complexity of the
  3236 syntax module and improves flexibility by separating parsing and
  3237 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3238 'fixes' etc.) are required in rare situations.
  3239 
  3240 * Syntax: constants introduced by new-style packages ('definition',
  3241 'abbreviation' etc.) are passed through the syntax module in
  3242 ``authentic mode''. This means that associated mixfix annotations
  3243 really stick to such constants, independently of potential name space
  3244 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3245 trees are represented slightly differently, may need to adapt syntax
  3246 translations accordingly. Use CONST marker in 'translations' and
  3247 @{const_syntax} antiquotation in 'parse_translation' etc.
  3248 
  3249 * Legacy goal package: reduced interface to the bare minimum required
  3250 to keep existing proof scripts running.  Most other user-level
  3251 functions are now part of the OldGoals structure, which is *not* open
  3252 by default (consider isatool expandshort before open OldGoals).
  3253 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3254 these tend to cause confusion about the actual goal (!) context being
  3255 used here, which is not necessarily the same as the_context().
  3256 
  3257 * Command 'find_theorems': supports "*" wild-card in "name:"
  3258 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3259 support a specific search form (see ProofGeneral/CHANGES).
  3260 
  3261 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3262 by default, which means that "prems" (and also "fixed variables") are
  3263 suppressed from proof state output.  Note that the ProofGeneral
  3264 settings mechanism allows to change and save options persistently, but
  3265 older versions of Isabelle will fail to start up if a negative prems
  3266 limit is imposed.
  3267 
  3268 * Local theory targets may be specified by non-nested blocks of
  3269 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3270 contain definitions, theorems etc., including any derived mechanism
  3271 that has been implemented on top of these primitives.  This concept
  3272 generalizes the existing ``theorem (in ...)'' towards more versatility
  3273 and scalability.
  3274 
  3275 * Proof General interface: proper undo of final 'end' command;
  3276 discontinued Isabelle/classic mode (ML proof scripts).
  3277 
  3278 
  3279 *** Document preparation ***
  3280 
  3281 * Added antiquotation @{theory name} which prints the given name,
  3282 after checking that it refers to a valid ancestor theory in the
  3283 current context.
  3284 
  3285 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3286 check the given source text as ML type/structure, printing verbatim.
  3287 
  3288 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3289 "c args == rhs" given in the current context.  (Any number of
  3290 arguments may be given on the LHS.)
  3291 
  3292 
  3293 *** Pure ***
  3294 
  3295 * The 'class' package offers a combination of axclass and locale to
  3296 achieve Haskell-like type classes in Isabelle.  Definitions and
  3297 theorems within a class context produce both relative results (with
  3298 implicit parameters according to the locale context), and polymorphic
  3299 constants with qualified polymorphism (according to the class
  3300 context).  Within the body context of a 'class' target, a separate
  3301 syntax layer ("user space type system") takes care of converting
  3302 between global polymorphic consts and internal locale representation.
  3303 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3304 "isatool doc classes" provides a tutorial.
  3305 
  3306 * Generic code generator framework allows to generate executable
  3307 code for ML and Haskell (including Isabelle classes).  A short usage
  3308 sketch:
  3309 
  3310     internal compilation:
  3311         export_code <list of constants (term syntax)> in SML
  3312     writing SML code to a file:
  3313         export_code <list of constants (term syntax)> in SML <filename>
  3314     writing OCaml code to a file:
  3315         export_code <list of constants (term syntax)> in OCaml <filename>
  3316     writing Haskell code to a bunch of files:
  3317         export_code <list of constants (term syntax)> in Haskell <filename>
  3318 
  3319     evaluating closed propositions to True/False using code generation:
  3320         method ``eval''
  3321 
  3322 Reasonable default setup of framework in HOL.
  3323 
  3324 Theorem attributs for selecting and transforming function equations theorems:
  3325 
  3326     [code fun]:        select a theorem as function equation for a specific constant
  3327     [code fun del]:    deselect a theorem as function equation for a specific constant
  3328     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3329     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3330 
  3331 User-defined serializations (target in {SML, OCaml, Haskell}):
  3332 
  3333     code_const <and-list of constants (term syntax)>
  3334       {(target) <and-list of const target syntax>}+
  3335 
  3336     code_type <and-list of type constructors>
  3337       {(target) <and-list of type target syntax>}+
  3338 
  3339     code_instance <and-list of instances>
  3340       {(target)}+
  3341         where instance ::= <type constructor> :: <class>
  3342 
  3343     code_class <and_list of classes>
  3344       {(target) <and-list of class target syntax>}+
  3345         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3346 
  3347 code_instance and code_class only are effective to target Haskell.
  3348 
  3349 For example usage see src/HOL/ex/Codegenerator.thy and
  3350 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3351 generation from Isabelle/HOL theories is available via "isatool doc
  3352 codegen".
  3353 
  3354 * Code generator: consts in 'consts_code' Isar commands are now
  3355 referred to by usual term syntax (including optional type
  3356 annotations).
  3357 
  3358 * Command 'no_translations' removes translation rules from theory
  3359 syntax.
  3360 
  3361 * Overloaded definitions are now actually checked for acyclic
  3362 dependencies.  The overloading scheme is slightly more general than
  3363 that of Haskell98, although Isabelle does not demand an exact
  3364 correspondence to type class and instance declarations.
  3365 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3366 exotic versions of overloading -- at the discretion of the user!
  3367 
  3368 Polymorphic constants are represented via type arguments, i.e. the
  3369 instantiation that matches an instance against the most general
  3370 declaration given in the signature.  For example, with the declaration
  3371 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3372 as c(nat).  Overloading is essentially simultaneous structural
  3373 recursion over such type arguments.  Incomplete specification patterns
  3374 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3375 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3376 Command 'print_theory' outputs the normalized system of recursive
  3377 equations, see section "definitions".
  3378 
  3379 * Configuration options are maintained within the theory or proof
  3380 context (with name and type bool/int/string), providing a very simple
  3381 interface to a poor-man's version of general context data.  Tools may
  3382 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3383 these values using Config.get etc.  Users may change options via an
  3384 associated attribute of the same name.  This form of context
  3385 declaration works particularly well with commands 'declare' or
  3386 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3387 very easy to avoid global references, which would not observe Isar
  3388 toplevel undo/redo and fail to work with multithreading.
  3389 
  3390 Various global ML references of Pure and HOL have been turned into
  3391 configuration options:
  3392 
  3393   Unify.search_bound		unify_search_bound
  3394   Unify.trace_bound		unify_trace_bound
  3395   Unify.trace_simp		unify_trace_simp
  3396   Unify.trace_types		unify_trace_types
  3397   Simplifier.simp_depth_limit	simp_depth_limit
  3398   Blast.depth_limit		blast_depth_limit
  3399   DatatypeProp.dtK		datatype_distinctness_limit
  3400   fast_arith_neq_limit  	fast_arith_neq_limit
  3401   fast_arith_split_limit	fast_arith_split_limit
  3402 
  3403 * Named collections of theorems may be easily installed as context
  3404 data using the functor NamedThmsFun (see also
  3405 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3406 attributes; there is also a toplevel print command.  This facility is
  3407 just a common case of general context data, which is the preferred way
  3408 for anything more complex than just a list of facts in canonical
  3409 order.
  3410 
  3411 * Isar: command 'declaration' augments a local theory by generic
  3412 declaration functions written in ML.  This enables arbitrary content
  3413 being added to the context, depending on a morphism that tells the
  3414 difference of the original declaration context wrt. the application
  3415 context encountered later on.
  3416 
  3417 * Isar: proper interfaces for simplification procedures.  Command
  3418 'simproc_setup' declares named simprocs (with match patterns, and body
  3419 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3420 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3421 
  3422 * Isar: an extra pair of brackets around attribute declarations
  3423 abbreviates a theorem reference involving an internal dummy fact,
  3424 which will be ignored later --- only the effect of the attribute on
  3425 the background context will persist.  This form of in-place
  3426 declarations is particularly useful with commands like 'declare' and
  3427 'using', for example ``have A using [[simproc a]] by simp''.
  3428 
  3429 * Isar: method "assumption" (and implicit closing of subproofs) now
  3430 takes simple non-atomic goal assumptions into account: after applying
  3431 an assumption as a rule the resulting subgoals are solved by atomic
  3432 assumption steps.  This is particularly useful to finish 'obtain'
  3433 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3434 without referring to the original premise "!!x. P x ==> thesis" in the
  3435 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3436 more permissive.
  3437 
  3438 * Isar: implicit use of prems from the Isar proof context is
  3439 considered a legacy feature.  Common applications like ``have A .''
  3440 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3441 referencing facts explicitly here improves readability and
  3442 maintainability of proof texts.
  3443 
  3444 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3445 the obtained context from the course of reasoning!  For example:
  3446 
  3447   assume "EX x y. A x & B y"   -- "any previous fact"
  3448   then guess x and y by clarify
  3449 
  3450 This technique is potentially adventurous, depending on the facts and
  3451 proof tools being involved here.
  3452 
  3453 * Isar: known facts from the proof context may be specified as literal
  3454 propositions, using ASCII back-quote syntax.  This works wherever
  3455 named facts used to be allowed so far, in proof commands, proof
  3456 methods, attributes etc.  Literal facts are retrieved from the context
  3457 according to unification of type and term parameters.  For example,
  3458 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3459 theorems in the current context, then these are valid literal facts:
  3460 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3461 
  3462 There is also a proof method "fact" which does the same composition
  3463 for explicit goal states, e.g. the following proof texts coincide with
  3464 certain special cases of literal facts:
  3465 
  3466   have "A" by fact                 ==  note `A`
  3467   have "A ==> B" by fact           ==  note `A ==> B`
  3468   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3469   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3470 
  3471 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3472 outer syntax.  Thus symbolic identifiers may be used without
  3473 additional white space in declarations like this: ``assume *: A''.
  3474 
  3475 * Isar: 'print_facts' prints all local facts of the current context,
  3476 both named and unnamed ones.
  3477 
  3478 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3479 
  3480   def x == "t" and y == "u"
  3481 
  3482 * Isar: added command 'unfolding', which is structurally similar to
  3483 'using', but affects both the goal state and facts by unfolding given
  3484 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3485 'unfolded' attribute may be replaced by first-class proof text.
  3486 
  3487 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3488 and command 'unfolding' now all support object-level equalities
  3489 (potentially conditional).  The underlying notion of rewrite rule is
  3490 analogous to the 'rule_format' attribute, but *not* that of the
  3491 Simplifier (which is usually more generous).
  3492 
  3493 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3494 premises of a theorem by n. Useful in conjunction with drule.
  3495 
  3496 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3497 method expression within a sandbox consisting of the first N
  3498 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3499 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3500 simplifies all new goals that emerge from applying rule foo to the
  3501 originally first one.
  3502 
  3503 * Isar: schematic goals are no longer restricted to higher-order
  3504 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3505 expected.
  3506 
  3507 * Isar: the conclusion of a long theorem statement is now either
  3508 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3509 (essentially a disjunction of cases with local parameters and
  3510 assumptions).  The latter allows to express general elimination rules
  3511 adequately; in this notation common elimination rules look like this:
  3512 
  3513   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3514     assumes "EX x. P x"
  3515     obtains x where "P x"
  3516 
  3517   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3518     assumes "A & B"
  3519     obtains A and B
  3520 
  3521   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3522     assumes "A | B"
  3523     obtains
  3524       A
  3525     | B
  3526 
  3527 The subsequent classical rules even refer to the formal "thesis"
  3528 explicitly:
  3529 
  3530   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3531     obtains "~ thesis"
  3532 
  3533   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3534     obtains "thesis ==> something"
  3535 
  3536 The actual proof of an 'obtains' statement is analogous to that of the
  3537 Isar proof element 'obtain', only that there may be several cases.
  3538 Optional case names may be specified in parentheses; these will be
  3539 available both in the present proof and as annotations in the
  3540 resulting rule, for later use with the 'cases' method (cf. attribute
  3541 case_names).
  3542 
  3543 * Isar: the assumptions of a long theorem statement are available as
  3544 "assms" fact in the proof context.  This is more appropriate than the
  3545 (historical) "prems", which refers to all assumptions of the current
  3546 context, including those from the target locale, proof body etc.
  3547 
  3548 * Isar: 'print_statement' prints theorems from the current theory or
  3549 proof context in long statement form, according to the syntax of a
  3550 top-level lemma.
  3551 
  3552 * Isar: 'obtain' takes an optional case name for the local context
  3553 introduction rule (default "that").
  3554 
  3555 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3556 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3557 to occur.
  3558 
  3559 * Pure: syntax "CONST name" produces a fully internalized constant
  3560 according to the current context.  This is particularly useful for
  3561 syntax translations that should refer to internal constant
  3562 representations independently of name spaces.
  3563 
  3564 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3565 instead of "FOO ". This allows multiple binder declarations to coexist
  3566 in the same context.  INCOMPATIBILITY.
  3567 
  3568 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3569 primitive that also works in a locale context (both for constants and
  3570 fixed variables). Type declaration and internal syntactic representation
  3571 of given constants retrieved from the context. Likewise, the
  3572 'no_notation' command allows to remove given syntax annotations from the
  3573 current context.
  3574 
  3575 * Isar/locales: new derived specification elements 'axiomatization',
  3576 'definition', 'abbreviation', which support type-inference, admit
  3577 object-level specifications (equality, equivalence).  See also the
  3578 isar-ref manual.  Examples:
  3579 
  3580   axiomatization
  3581     eq  (infix "===" 50) where
  3582     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3583 
  3584   definition "f x y = x + y + 1"
  3585   definition g where "g x = f x x"
  3586 
  3587   abbreviation
  3588     neq  (infix "=!=" 50) where
  3589     "x =!= y == ~ (x === y)"
  3590 
  3591 These specifications may be also used in a locale context.  Then the
  3592 constants being introduced depend on certain fixed parameters, and the
  3593 constant name is qualified by the locale base name.  An internal
  3594 abbreviation takes care for convenient input and output, making the
  3595 parameters implicit and using the original short name.  See also
  3596 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3597 entities from a monomorphic theory.
  3598 
  3599 Presently, abbreviations are only available 'in' a target locale, but
  3600 not inherited by general import expressions.  Also note that
  3601 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3602 'translations' in common applications.  The "no_abbrevs" print mode
  3603 prevents folding of abbreviations in term output.
  3604 
  3605 Concrete syntax is attached to specified constants in internal form,
  3606 independently of name spaces.  The parse tree representation is
  3607 slightly different -- use 'notation' instead of raw 'syntax', and
  3608 'translations' with explicit "CONST" markup to accommodate this.
  3609 
  3610 * Pure/Isar: unified syntax for new-style specification mechanisms
  3611 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3612 full type inference and dummy patterns ("_").  For example:
  3613 
  3614   definition "K x _ = x"
  3615 
  3616   inductive conj for A B
  3617   where "A ==> B ==> conj A B"
  3618 
  3619 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3620 the current context.  Print mode "no_abbrevs" prevents inversion of
  3621 abbreviations on output.
  3622 
  3623 * Isar/locales: improved parameter handling: use of locales "var" and
  3624 "struct" no longer necessary; - parameter renamings are no longer
  3625 required to be injective.  For example, this allows to define
  3626 endomorphisms as locale endom = homom mult mult h.
  3627 
  3628 * Isar/locales: changed the way locales with predicates are defined.
  3629 Instead of accumulating the specification, the imported expression is
  3630 now an interpretation.  INCOMPATIBILITY: different normal form of
  3631 locale expressions.  In particular, in interpretations of locales with
  3632 predicates, goals repesenting already interpreted fragments are not
  3633 removed automatically.  Use methods `intro_locales' and
  3634 `unfold_locales'; see below.
  3635 
  3636 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3637 provide backward reasoning on locales predicates.  The methods are
  3638 aware of interpretations and discharge corresponding goals.
  3639 `intro_locales' is less aggressive then `unfold_locales' and does not
  3640 unfold predicates to assumptions.
  3641 
  3642 * Isar/locales: the order in which locale fragments are accumulated
  3643 has changed.  This enables to override declarations from fragments due
  3644 to interpretations -- for example, unwanted simp rules.
  3645 
  3646 * Isar/locales: interpretation in theories and proof contexts has been
  3647 extended.  One may now specify (and prove) equations, which are
  3648 unfolded in interpreted theorems.  This is useful for replacing
  3649 defined concepts (constants depending on locale parameters) by
  3650 concepts already existing in the target context.  Example:
  3651 
  3652   interpretation partial_order ["op <= :: [int, int] => bool"]
  3653     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3654 
  3655 Typically, the constant `partial_order.less' is created by a
  3656 definition specification element in the context of locale
  3657 partial_order.
  3658 
  3659 * Method "induct": improved internal context management to support
  3660 local fixes and defines on-the-fly. Thus explicit meta-level
  3661 connectives !!  and ==> are rarely required anymore in inductive goals
  3662 (using object-logic connectives for this purpose has been long
  3663 obsolete anyway). Common proof patterns are explained in
  3664 src/HOL/Induct/Common_Patterns.thy, see also
  3665 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3666 examples.
  3667 
  3668 * Method "induct": improved handling of simultaneous goals. Instead of
  3669 introducing object-level conjunction, the statement is now split into
  3670 several conclusions, while the corresponding symbolic cases are nested
  3671 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3672 see src/HOL/Induct/Common_Patterns.thy, for example.
  3673 
  3674 * Method "induct": mutual induction rules are now specified as a list
  3675 of rule sharing the same induction cases. HOL packages usually provide
  3676 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3677 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3678 mutual induction rules differently, i.e. like this:
  3679 
  3680   (induct rule: foo_bar.inducts)
  3681   (induct set: foo bar)
  3682   (induct pred: foo bar)
  3683   (induct type: foo bar)
  3684 
  3685 The ML function ProjectRule.projections turns old-style rules into the
  3686 new format.
  3687 
  3688 * Method "coinduct": dual of induction, see
  3689 src/HOL/Library/Coinductive_List.thy for various examples.
  3690 
  3691 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3692 considered a legacy feature.
  3693 
  3694 * Attribute "symmetric" produces result with standardized schematic
  3695 variables (index 0).  Potential INCOMPATIBILITY.
  3696 
  3697 * Simplifier: by default the simplifier trace only shows top level
  3698 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3699 default. Thus there is less danger of being flooded by the trace. The
  3700 trace indicates where parts have been suppressed.
  3701   
  3702 * Provers/classical: removed obsolete classical version of elim_format
  3703 attribute; classical elim/dest rules are now treated uniformly when
  3704 manipulating the claset.
  3705 
  3706 * Provers/classical: stricter checks to ensure that supplied intro,
  3707 dest and elim rules are well-formed; dest and elim rules must have at
  3708 least one premise.
  3709 
  3710 * Provers/classical: attributes dest/elim/intro take an optional
  3711 weight argument for the rule (just as the Pure versions).  Weights are
  3712 ignored by automated tools, but determine the search order of single
  3713 rule steps.
  3714 
  3715 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3716 where the body does not mention the bound variable.  Note that dummy
  3717 patterns implicitly depend on their context of bounds, which makes
  3718 "{_. _}" match any set comprehension as expected.  Potential
  3719 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3720 constant "_idtdummy" in the binding position.
  3721 
  3722 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3723 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3724 for example "A -> B" => "Pi A (%_. B)".
  3725 
  3726 * Pure: 'class_deps' command visualizes the subclass relation, using
  3727 the graph browser tool.
  3728 
  3729 * Pure: 'print_theory' now suppresses certain internal declarations by
  3730 default; use '!' option for full details.
  3731 
  3732 
  3733 *** HOL ***
  3734 
  3735 * Method "metis" proves goals by applying the Metis general-purpose
  3736 resolution prover (see also http://gilith.com/software/metis/).
  3737 Examples are in the directory MetisExamples.  WARNING: the
  3738 Isabelle/HOL-Metis integration does not yet work properly with
  3739 multi-threading.
  3740   
  3741 * Command 'sledgehammer' invokes external automatic theorem provers as
  3742 background processes.  It generates calls to the "metis" method if
  3743 successful. These can be pasted into the proof.  Users do not have to
  3744 wait for the automatic provers to return.  WARNING: does not really
  3745 work with multi-threading.
  3746 
  3747 * New "auto_quickcheck" feature tests outermost goal statements for
  3748 potential counter-examples.  Controlled by ML references
  3749 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3750 5000 milliseconds).  Fails silently if statements is outside of
  3751 executable fragment, or any other codgenerator problem occurs.
  3752 
  3753 * New constant "undefined" with axiom "undefined x = undefined".
  3754 
  3755 * Added class "HOL.eq", allowing for code generation with polymorphic
  3756 equality.
  3757 
  3758 * Some renaming of class constants due to canonical name prefixing in
  3759 the new 'class' package:
  3760 
  3761     HOL.abs ~> HOL.abs_class.abs
  3762     HOL.divide ~> HOL.divide_class.divide
  3763     0 ~> HOL.zero_class.zero
  3764     1 ~> HOL.one_class.one
  3765     op + ~> HOL.plus_class.plus
  3766     op - ~> HOL.minus_class.minus
  3767     uminus ~> HOL.minus_class.uminus
  3768     op * ~> HOL.times_class.times
  3769     op < ~> HOL.ord_class.less
  3770     op <= > HOL.ord_class.less_eq
  3771     Nat.power ~> Power.power_class.power
  3772     Nat.size ~> Nat.size_class.size
  3773     Numeral.number_of ~> Numeral.number_class.number_of
  3774     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3775     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3776     Orderings.min ~> Orderings.ord_class.min
  3777     Orderings.max ~> Orderings.ord_class.max
  3778     Divides.op div ~> Divides.div_class.div
  3779     Divides.op mod ~> Divides.div_class.mod
  3780     Divides.op dvd ~> Divides.div_class.dvd
  3781 
  3782 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3783 
  3784 a) User-defined constants using any of the names "plus", "minus",
  3785 "times", "less" or "less_eq". The standard syntax translations for
  3786 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3787 names.
  3788 
  3789 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3790 INCOMPATIBILITY: use more specific names.
  3791 
  3792 c) Permutative equations (e.g. "a + b = b + a")
  3793 Since the change of names also changes the order of terms, permutative
  3794 rewrite rules may get applied in a different order. Experience shows
  3795 that this is rarely the case (only two adaptions in the whole Isabelle
  3796 distribution).  INCOMPATIBILITY: rewrite proofs
  3797 
  3798 d) ML code directly refering to constant names
  3799 This in general only affects hand-written proof tactics, simprocs and
  3800 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3801 Consider using @{const_name} antiquotation.
  3802 
  3803 * New class "default" with associated constant "default".
  3804 
  3805 * Function "sgn" is now overloaded and available on int, real, complex
  3806 (and other numeric types), using class "sgn".  Two possible defs of
  3807 sgn are given as equational assumptions in the classes sgn_if and
  3808 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3809 INCOMPATIBILITY.
  3810 
  3811 * Locale "partial_order" now unified with class "order" (cf. theory
  3812 Orderings), added parameter "less".  INCOMPATIBILITY.
  3813 
  3814 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3815 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3816 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3817 
  3818 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3819 changed order of proof goals in instance proofs.
  3820 
  3821 * The transitivity reasoner for partial and linear orders is set up
  3822 for classes "order" and "linorder".  Instances of the reasoner are available
  3823 in all contexts importing or interpreting the corresponding locales.
  3824 Method "order" invokes the reasoner separately; the reasoner
  3825 is also integrated with the Simplifier as a solver.  Diagnostic
  3826 command 'print_orders' shows the available instances of the reasoner
  3827 in the current context.
  3828 
  3829 * Localized monotonicity predicate in theory "Orderings"; integrated
  3830 lemmas max_of_mono and min_of_mono with this predicate.
  3831 INCOMPATIBILITY.
  3832 
  3833 * Formulation of theorem "dense" changed slightly due to integration
  3834 with new class dense_linear_order.
  3835 
  3836 * Uniform lattice theory development in HOL.
  3837 
  3838     constants "meet" and "join" now named "inf" and "sup"
  3839     constant "Meet" now named "Inf"
  3840 
  3841     classes "meet_semilorder" and "join_semilorder" now named
  3842       "lower_semilattice" and "upper_semilattice"
  3843     class "lorder" now named "lattice"
  3844     class "comp_lat" now named "complete_lattice"
  3845 
  3846     Instantiation of lattice classes allows explicit definitions
  3847     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3848 
  3849   INCOMPATIBILITY.  Theorem renames:
  3850 
  3851     meet_left_le            ~> inf_le1
  3852     meet_right_le           ~> inf_le2
  3853     join_left_le            ~> sup_ge1
  3854     join_right_le           ~> sup_ge2
  3855     meet_join_le            ~> inf_sup_ord
  3856     le_meetI                ~> le_infI
  3857     join_leI                ~> le_supI
  3858     le_meet                 ~> le_inf_iff
  3859     le_join                 ~> ge_sup_conv
  3860     meet_idempotent         ~> inf_idem
  3861     join_idempotent         ~> sup_idem
  3862     meet_comm               ~> inf_commute
  3863     join_comm               ~> sup_commute
  3864     meet_leI1               ~> le_infI1
  3865     meet_leI2               ~> le_infI2
  3866     le_joinI1               ~> le_supI1
  3867     le_joinI2               ~> le_supI2
  3868     meet_assoc              ~> inf_assoc
  3869     join_assoc              ~> sup_assoc
  3870     meet_left_comm          ~> inf_left_commute
  3871     meet_left_idempotent    ~> inf_left_idem
  3872     join_left_comm          ~> sup_left_commute
  3873     join_left_idempotent    ~> sup_left_idem
  3874     meet_aci                ~> inf_aci
  3875     join_aci                ~> sup_aci
  3876     le_def_meet             ~> le_iff_inf
  3877     le_def_join             ~> le_iff_sup
  3878     join_absorp2            ~> sup_absorb2
  3879     join_absorp1            ~> sup_absorb1
  3880     meet_absorp1            ~> inf_absorb1
  3881     meet_absorp2            ~> inf_absorb2
  3882     meet_join_absorp        ~> inf_sup_absorb
  3883     join_meet_absorp        ~> sup_inf_absorb
  3884     distrib_join_le         ~> distrib_sup_le
  3885     distrib_meet_le         ~> distrib_inf_le
  3886 
  3887     add_meet_distrib_left   ~> add_inf_distrib_left
  3888     add_join_distrib_left   ~> add_sup_distrib_left
  3889     is_join_neg_meet        ~> is_join_neg_inf
  3890     is_meet_neg_join        ~> is_meet_neg_sup
  3891     add_meet_distrib_right  ~> add_inf_distrib_right
  3892     add_join_distrib_right  ~> add_sup_distrib_right
  3893     add_meet_join_distribs  ~> add_sup_inf_distribs
  3894     join_eq_neg_meet        ~> sup_eq_neg_inf
  3895     meet_eq_neg_join        ~> inf_eq_neg_sup
  3896     add_eq_meet_join        ~> add_eq_inf_sup
  3897     meet_0_imp_0            ~> inf_0_imp_0
  3898     join_0_imp_0            ~> sup_0_imp_0
  3899     meet_0_eq_0             ~> inf_0_eq_0
  3900     join_0_eq_0             ~> sup_0_eq_0
  3901     neg_meet_eq_join        ~> neg_inf_eq_sup
  3902     neg_join_eq_meet        ~> neg_sup_eq_inf
  3903     join_eq_if              ~> sup_eq_if
  3904 
  3905     mono_meet               ~> mono_inf
  3906     mono_join               ~> mono_sup
  3907     meet_bool_eq            ~> inf_bool_eq
  3908     join_bool_eq            ~> sup_bool_eq
  3909     meet_fun_eq             ~> inf_fun_eq
  3910     join_fun_eq             ~> sup_fun_eq
  3911     meet_set_eq             ~> inf_set_eq
  3912     join_set_eq             ~> sup_set_eq
  3913     meet1_iff               ~> inf1_iff
  3914     meet2_iff               ~> inf2_iff
  3915     meet1I                  ~> inf1I
  3916     meet2I                  ~> inf2I
  3917     meet1D1                 ~> inf1D1
  3918     meet2D1                 ~> inf2D1
  3919     meet1D2                 ~> inf1D2
  3920     meet2D2                 ~> inf2D2
  3921     meet1E                  ~> inf1E
  3922     meet2E                  ~> inf2E
  3923     join1_iff               ~> sup1_iff
  3924     join2_iff               ~> sup2_iff
  3925     join1I1                 ~> sup1I1
  3926     join2I1                 ~> sup2I1
  3927     join1I1                 ~> sup1I1
  3928     join2I2                 ~> sup1I2
  3929     join1CI                 ~> sup1CI
  3930     join2CI                 ~> sup2CI
  3931     join1E                  ~> sup1E
  3932     join2E                  ~> sup2E
  3933 
  3934     is_meet_Meet            ~> is_meet_Inf
  3935     Meet_bool_def           ~> Inf_bool_def
  3936     Meet_fun_def            ~> Inf_fun_def
  3937     Meet_greatest           ~> Inf_greatest
  3938     Meet_lower              ~> Inf_lower
  3939     Meet_set_def            ~> Inf_set_def
  3940 
  3941     Sup_def                 ~> Sup_Inf
  3942     Sup_bool_eq             ~> Sup_bool_def
  3943     Sup_fun_eq              ~> Sup_fun_def
  3944     Sup_set_eq              ~> Sup_set_def
  3945 
  3946     listsp_meetI            ~> listsp_infI
  3947     listsp_meet_eq          ~> listsp_inf_eq
  3948 
  3949     meet_min                ~> inf_min
  3950     join_max                ~> sup_max
  3951 
  3952 * Added syntactic class "size"; overloaded constant "size" now has
  3953 type "'a::size ==> bool"
  3954 
  3955 * Internal reorganisation of `size' of datatypes: size theorems
  3956 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3957 simplification rules by default!); theorems "prod.size" now named
  3958 "*.size".
  3959 
  3960 * Class "div" now inherits from class "times" rather than "type".
  3961 INCOMPATIBILITY.
  3962 
  3963 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3964 Linorder etc.  have disappeared; operations defined in terms of
  3965 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3966 
  3967 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3968 
  3969 * HOL-Word: New extensive library and type for generic, fixed size
  3970 machine words, with arithemtic, bit-wise, shifting and rotating
  3971 operations, reflection into int, nat, and bool lists, automation for
  3972 linear arithmetic (by automatic reflection into nat or int), including
  3973 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3974 arithmetic type classes, supporting automatic simplification of
  3975 numerals on all operations.
  3976 
  3977 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3978 
  3979 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3980 
  3981 * Code generator library theories:
  3982   - Code_Integer represents HOL integers by big integer literals in target
  3983     languages.
  3984   - Code_Char represents HOL characters by character literals in target
  3985     languages.
  3986   - Code_Char_chr like Code_Char, but also offers treatment of character
  3987     codes; includes Code_Integer.
  3988   - Executable_Set allows to generate code for finite sets using lists.
  3989   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3990     denominator).
  3991   - Executable_Real implements a subset of real numbers, namly those
  3992     representable by rational numbers.
  3993   - Efficient_Nat implements natural numbers by integers, which in general will
  3994     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3995     includes Code_Integer.
  3996   - Code_Index provides an additional datatype index which is mapped to
  3997     target-language built-in integers.
  3998   - Code_Message provides an additional datatype message_string which is isomorphic to
  3999     strings; messages are mapped to target-language strings.
  4000 
  4001 * New package for inductive predicates
  4002 
  4003   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4004 
  4005     inductive
  4006       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4007       for z_1 :: U_1 and ... and z_n :: U_m
  4008     where
  4009       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4010     | ...
  4011 
  4012   with full support for type-inference, rather than
  4013 
  4014     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4015 
  4016     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4017     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4018 
  4019     inductive "s z_1 ... z_m"
  4020     intros
  4021       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4022       ...
  4023 
  4024   For backward compatibility, there is a wrapper allowing inductive
  4025   sets to be defined with the new package via
  4026 
  4027     inductive_set
  4028       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4029       for z_1 :: U_1 and ... and z_n :: U_m
  4030     where
  4031       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4032     | ...
  4033 
  4034   or
  4035 
  4036     inductive_set
  4037       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4038       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4039       for z_1 :: U_1 and ... and z_n :: U_m
  4040     where
  4041       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4042     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4043     | ...
  4044 
  4045   if the additional syntax "p ..." is required.
  4046 
  4047   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4048   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4049 
  4050   INCOMPATIBILITIES:
  4051 
  4052   - Since declaration and definition of inductive sets or predicates
  4053     is no longer separated, abbreviations involving the newly
  4054     introduced sets or predicates must be specified together with the
  4055     introduction rules after the 'where' keyword (see above), rather
  4056     than before the actual inductive definition.
  4057 
  4058   - The variables in induction and elimination rules are now
  4059     quantified in the order of their occurrence in the introduction
  4060     rules, rather than in alphabetical order. Since this may break
  4061     some proofs, these proofs either have to be repaired, e.g. by
  4062     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4063     statements of the form
  4064 
  4065       case (rule_i a_i_1 ... a_i_{k_i})
  4066 
  4067     or the old order of quantification has to be restored by explicitly adding
  4068     meta-level quantifiers in the introduction rules, i.e.
  4069 
  4070       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4071 
  4072   - The format of the elimination rules is now
  4073 
  4074       p z_1 ... z_m x_1 ... x_n ==>
  4075         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4076         ==> ... ==> P
  4077 
  4078     for predicates and
  4079 
  4080       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4081         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4082         ==> ... ==> P
  4083 
  4084     for sets rather than
  4085 
  4086       x : s z_1 ... z_m ==>
  4087         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4088         ==> ... ==> P
  4089 
  4090     This may require terms in goals to be expanded to n-tuples
  4091     (e.g. using case_tac or simplification with the split_paired_all
  4092     rule) before the above elimination rule is applicable.
  4093 
  4094   - The elimination or case analysis rules for (mutually) inductive
  4095     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4096     list of rules "p_1_..._p_k.elims" is no longer available.
  4097 
  4098 * New package "function"/"fun" for general recursive functions,
  4099 supporting mutual and nested recursion, definitions in local contexts,
  4100 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4101 for small examples, and the separate tutorial on the function
  4102 package. The old recdef "package" is still available as before, but
  4103 users are encouraged to use the new package.
  4104 
  4105 * Method "lexicographic_order" automatically synthesizes termination
  4106 relations as lexicographic combinations of size measures. 
  4107 
  4108 * Case-expressions allow arbitrary constructor-patterns (including
  4109 "_") and take their order into account, like in functional
  4110 programming.  Internally, this is translated into nested
  4111 case-expressions; missing cases are added and mapped to the predefined
  4112 constant "undefined". In complicated cases printing may no longer show
  4113 the original input but the internal form. Lambda-abstractions allow
  4114 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4115 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4116 variable.
  4117 
  4118 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4119 is an abbreviation for "of_nat :: nat => int". The simplification
  4120 rules for "of_nat" have been changed to work like "int" did
  4121 previously.  Potential INCOMPATIBILITY:
  4122   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4123   - of_nat_diff and of_nat_mult are no longer default simp rules
  4124 
  4125 * Method "algebra" solves polynomial equations over (semi)rings using
  4126 Groebner bases. The (semi)ring structure is defined by locales and the
  4127 tool setup depends on that generic context. Installing the method for
  4128 a specific type involves instantiating the locale and possibly adding
  4129 declarations for computation on the coefficients.  The method is
  4130 already instantiated for natural numbers and for the axiomatic class
  4131 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4132 CALCULEMUS 2007 for the general principles underlying this
  4133 architecture of context-aware proof-tools.
  4134 
  4135 * Method "ferrack" implements quantifier elimination over
  4136 special-purpose dense linear orders using locales (analogous to
  4137 "algebra"). The method is already installed for class
  4138 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4139 rat, etc.
  4140 
  4141 * Former constant "List.op @" now named "List.append".  Use ML
  4142 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4143 circumvent possible incompatibilities when working on ML level.
  4144 
  4145 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4146 
  4147 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4148 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4149 
  4150 * New syntax for Haskell-like list comprehension (input only), eg.
  4151 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4152 
  4153 * The special syntax for function "filter" has changed from [x :
  4154 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4155 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4156 
  4157 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4158 defined on nat only, as an abbreviation for [a..<Suc b]
  4159 INCOMPATIBILITY.
  4160 
  4161 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4162 
  4163 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4164 
  4165 * New lemma collection field_simps (an extension of ring_simps) for
  4166 manipulating (in)equations involving division. Multiplies with all
  4167 denominators that can be proved to be non-zero (in equations) or
  4168 positive/negative (in inequations).
  4169 
  4170 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4171 have been improved and renamed to ring_simps, group_simps and
  4172 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4173 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4174 
  4175 * Theory Library/Commutative_Ring: switched from recdef to function
  4176 package; constants add, mul, pow now curried.  Infix syntax for
  4177 algebraic operations.
  4178 
  4179 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4180 INCOMPATIBILITY.
  4181 
  4182 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4183 INCOMPATIBILITY.
  4184 
  4185 * HOL/records: generalised field-update to take a function on the
  4186 field rather than the new value: r(|A := x|) is translated to A_update
  4187 (K x) r The K-combinator that is internally used is called K_record.
  4188 INCOMPATIBILITY: Usage of the plain update functions has to be
  4189 adapted.
  4190  
  4191 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4192 * x = 0, which are required for a semiring.  Richer structures do not
  4193 inherit from semiring_0 anymore, because this property is a theorem
  4194 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4195 there is more to prove, but this is mostly trivial.
  4196 
  4197 * Class "recpower" is generalized to arbitrary monoids, not just
  4198 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4199 commutativity or semiring properties additionally.
  4200 
  4201 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4202 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4203 better use 'abbreviation'.
  4204 
  4205 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4206 
  4207 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4208 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4209 significant changes for setting up numeral syntax for types:
  4210   - New constants Numeral.pred and Numeral.succ instead
  4211       of former Numeral.bin_pred and Numeral.bin_succ.
  4212   - Use integer operations instead of bin_add, bin_mult and so on.
  4213   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4214   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4215 
  4216 See src/HOL/Integ/IntArith.thy for an example setup.
  4217 
  4218 * Command 'normal_form' computes the normal form of a term that may
  4219 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4220 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4221 heavy-duty computations because the functions are compiled to ML
  4222 first.  Correspondingly, a method "normalization" is provided.  See
  4223 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4224 
  4225 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4226 25 like -->); output depends on the "iff" print_mode, the default is
  4227 "A = B" (with priority 50).
  4228 
  4229 * Relations less (<) and less_eq (<=) are also available on type bool.
  4230 Modified syntax to disallow nesting without explicit parentheses,
  4231 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4232 INCOMPATIBILITY.
  4233 
  4234 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4235 
  4236 * Relation composition operator "op O" now has precedence 75 and binds
  4237 stronger than union and intersection. INCOMPATIBILITY.
  4238 
  4239 * The old set interval syntax "{m..n(}" (and relatives) has been
  4240 removed.  Use "{m..<n}" (and relatives) instead.
  4241 
  4242 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4243 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4244 ``declare [[simproc del: neq]]''.
  4245 
  4246 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4247 True/False.
  4248 
  4249 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4250 
  4251 * Theorem setsum_mult renamed to setsum_right_distrib.
  4252 
  4253 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4254 ``rule'' method.
  4255 
  4256 * Reimplemented methods "sat" and "satx", with several improvements:
  4257 goals no longer need to be stated as "<prems> ==> False", equivalences
  4258 (i.e. "=" on type bool) are handled, variable names of the form
  4259 "lit_<n>" are no longer reserved, significant speedup.
  4260 
  4261 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4262 zChaff is still supported as well.
  4263 
  4264 * 'inductive' and 'datatype': provide projections of mutual rules,
  4265 bundled as foo_bar.inducts;
  4266 
  4267 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4268 Library.
  4269 
  4270 * Library: moved theory Accessible_Part to main HOL.
  4271 
  4272 * Library: added theory Coinductive_List of potentially infinite lists
  4273 as greatest fixed-point.
  4274 
  4275 * Library: added theory AssocList which implements (finite) maps as
  4276 association lists.
  4277 
  4278 * Method "evaluation" solves goals (i.e. a boolean expression)
  4279 efficiently by compiling it to ML.  The goal is "proved" (via an
  4280 oracle) if it evaluates to True.
  4281 
  4282 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4283 also when invoked by the simplifier.  This results in the Simplifier
  4284 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4285 Configuration option fast_arith_split_limit=0 recovers the old
  4286 behavior.
  4287 
  4288 * Support for hex (0x20) and binary (0b1001) numerals.
  4289 
  4290 * New method: reify eqs (t), where eqs are equations for an
  4291 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4292 parameter, computes a term s::'b and a list xs::'a list and proves the
  4293 theorem I xs s = t. This is also known as reification or quoting. The
  4294 resulting theorem is applied to the subgoal to substitute t with I xs
  4295 s.  If t is omitted, the subgoal itself is reified.
  4296 
  4297 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4298 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4299 where f is supposed to be a computable function (in the sense of code
  4300 generattion). The method uses reify to compute s and xs as above then
  4301 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4302 r and finally gets the theorem t = r, which is again applied to the
  4303 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4304 
  4305 * Reflection: Automatic reification now handels binding, an example is
  4306 available in src/HOL/ex/ReflectionEx.thy
  4307 
  4308 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4309 command 'statespace' that is similar to 'record', but introduces an
  4310 abstract specification based on the locale infrastructure instead of
  4311 HOL types.  This leads to extra flexibility in composing state spaces,
  4312 in particular multiple inheritance and renaming of components.
  4313 
  4314 
  4315 *** HOL-Complex ***
  4316 
  4317 * Hyperreal: Functions root and sqrt are now defined on negative real
  4318 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4319 Nonnegativity side conditions have been removed from many lemmas, so
  4320 that more subgoals may now be solved by simplification; potential
  4321 INCOMPATIBILITY.
  4322 
  4323 * Real: new type classes formalize real normed vector spaces and
  4324 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4325 and norm :: 'a => real.
  4326 
  4327 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4328 reals into other types. The overloaded constant Reals :: 'a set is now
  4329 defined as range of_real; potential INCOMPATIBILITY.
  4330 
  4331 * Real: proper support for ML code generation, including 'quickcheck'.
  4332 Reals are implemented as arbitrary precision rationals.
  4333 
  4334 * Hyperreal: Several constants that previously worked only for the
  4335 reals have been generalized, so they now work over arbitrary vector
  4336 spaces. Type annotations may need to be added in some cases; potential
  4337 INCOMPATIBILITY.
  4338 
  4339   Infinitesimal  :: ('a::real_normed_vector) star set
  4340   HFinite        :: ('a::real_normed_vector) star set
  4341   HInfinite      :: ('a::real_normed_vector) star set
  4342   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4343   monad          :: ('a::real_normed_vector) star => 'a star set
  4344   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4345   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4346   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4347   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4348   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4349   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4350   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4351   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4352   sgn            :: 'a::real_normed_vector => 'a
  4353   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4354 
  4355 * Complex: Some complex-specific constants are now abbreviations for
  4356 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4357 hnorm.  Other constants have been entirely removed in favor of the
  4358 polymorphic versions (INCOMPATIBILITY):
  4359 
  4360   approx        <-- capprox
  4361   HFinite       <-- CFinite
  4362   HInfinite     <-- CInfinite
  4363   Infinitesimal <-- CInfinitesimal
  4364   monad         <-- cmonad
  4365   galaxy        <-- cgalaxy
  4366   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4367   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4368   (ns)deriv     <-- (ns)cderiv
  4369 
  4370 
  4371 *** HOL-Algebra ***
  4372 
  4373 * Formalisation of ideals and the quotient construction over rings.
  4374 
  4375 * Order and lattice theory no longer based on records.
  4376 INCOMPATIBILITY.
  4377 
  4378 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4379 greatest_closed.  INCOMPATIBILITY.
  4380 
  4381 * Method algebra is now set up via an attribute.  For examples see
  4382 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4383 of algebraic structures.
  4384 
  4385 * Renamed theory CRing to Ring.
  4386 
  4387 
  4388 *** HOL-Nominal ***
  4389 
  4390 * Substantial, yet incomplete support for nominal datatypes (binding
  4391 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4392 src/HOL/Nominal/Examples.  Prospective users should consult
  4393 http://isabelle.in.tum.de/nominal/
  4394 
  4395 
  4396 *** ML ***
  4397 
  4398 * ML basics: just one true type int, which coincides with IntInf.int
  4399 (even on SML/NJ).
  4400 
  4401 * ML within Isar: antiquotations allow to embed statically-checked
  4402 formal entities in the source, referring to the context available at
  4403 compile-time.  For example:
  4404 
  4405 ML {* @{sort "{zero,one}"} *}
  4406 ML {* @{typ "'a => 'b"} *}
  4407 ML {* @{term "%x. x"} *}
  4408 ML {* @{prop "x == y"} *}
  4409 ML {* @{ctyp "'a => 'b"} *}
  4410 ML {* @{cterm "%x. x"} *}
  4411 ML {* @{cprop "x == y"} *}
  4412 ML {* @{thm asm_rl} *}
  4413 ML {* @{thms asm_rl} *}
  4414 ML {* @{type_name c} *}
  4415 ML {* @{type_syntax c} *}
  4416 ML {* @{const_name c} *}
  4417 ML {* @{const_syntax c} *}
  4418 ML {* @{context} *}
  4419 ML {* @{theory} *}
  4420 ML {* @{theory Pure} *}
  4421 ML {* @{theory_ref} *}
  4422 ML {* @{theory_ref Pure} *}
  4423 ML {* @{simpset} *}
  4424 ML {* @{claset} *}
  4425 ML {* @{clasimpset} *}
  4426 
  4427 The same works for sources being ``used'' within an Isar context.
  4428 
  4429 * ML in Isar: improved error reporting; extra verbosity with
  4430 ML_Context.trace enabled.
  4431 
  4432 * Pure/General/table.ML: the join operations now works via exceptions
  4433 DUP/SAME instead of type option. This is simpler in simple cases, and
  4434 admits slightly more efficient complex applications.
  4435 
  4436 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4437 use Context.generic instead of just theory.
  4438 
  4439 * Pure: datatype Context.generic joins theory/Proof.context and
  4440 provides some facilities for code that works in either kind of
  4441 context, notably GenericDataFun for uniform theory and proof data.
  4442 
  4443 * Pure: simplified internal attribute type, which is now always
  4444 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4445 local (Proof.context) attributes have been discontinued, while
  4446 minimizing code duplication. Thm.rule_attribute and
  4447 Thm.declaration_attribute build canonical attributes; see also structure
  4448 Context for further operations on Context.generic, notably
  4449 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4450 declarations and definitions.
  4451 
  4452 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4453 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4454 init only required for impure data. INCOMPATIBILITY: empty really need
  4455 to be empty (no dependencies on theory content!)
  4456 
  4457 * Pure/kernel: consts certification ignores sort constraints given in
  4458 signature declarations. (This information is not relevant to the
  4459 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4460 potential INCOMPATIBILITY.
  4461 
  4462 * Pure: axiomatic type classes are now purely definitional, with
  4463 explicit proofs of class axioms and super class relations performed
  4464 internally. See Pure/axclass.ML for the main internal interfaces --
  4465 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4466 AxClass.axiomatize_class/classrel/arity supersede
  4467 Sign.add_classes/classrel/arities.
  4468 
  4469 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4470 global/local versions on theory vs. Proof.context have been
  4471 discontinued; Attrib.syntax and Method.syntax have been adapted
  4472 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4473 attributes, methods, etc.
  4474 
  4475 * Pure: several functions of signature "... -> theory -> theory * ..."
  4476 have been reoriented to "... -> theory -> ... * theory" in order to
  4477 allow natural usage in combination with the ||>, ||>>, |-> and
  4478 fold_map combinators.
  4479 
  4480 * Pure: official theorem names (closed derivations) and additional
  4481 comments (tags) are now strictly separate.  Name hints -- which are
  4482 maintained as tags -- may be attached any time without affecting the
  4483 derivation.
  4484 
  4485 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4486 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4487 achieve the old behaviour.
  4488 
  4489 * Pure: the "Goal" constant is now called "prop", supporting a
  4490 slightly more general idea of ``protecting'' meta-level rule
  4491 statements.
  4492 
  4493 * Pure: Logic.(un)varify only works in a global context, which is now
  4494 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4495 Logic.legacy_(un)varify as temporary workaround.
  4496 
  4497 * Pure: structure Name provides scalable operations for generating
  4498 internal variable names, notably Name.variants etc.  This replaces
  4499 some popular functions from term.ML:
  4500 
  4501   Term.variant		->  Name.variant
  4502   Term.variantlist	->  Name.variant_list
  4503   Term.invent_names	->  Name.invent_list
  4504 
  4505 Note that low-level renaming rarely occurs in new code -- operations
  4506 from structure Variable are used instead (see below).
  4507 
  4508 * Pure: structure Variable provides fundamental operations for proper
  4509 treatment of fixed/schematic variables in a context.  For example,
  4510 Variable.import introduces fixes for schematics of given facts and
  4511 Variable.export reverses the effect (up to renaming) -- this replaces
  4512 various freeze_thaw operations.
  4513 
  4514 * Pure: structure Goal provides simple interfaces for
  4515 init/conclude/finish and tactical prove operations (replacing former
  4516 Tactic.prove).  Goal.prove is the canonical way to prove results
  4517 within a given context; Goal.prove_global is a degraded version for
  4518 theory level goals, including a global Drule.standard.  Note that
  4519 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4520 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4521 in a locale context).
  4522 
  4523 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4524 and type checking (Syntax.check_term etc.), with common combinations
  4525 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4526 which are considered legacy and await removal.
  4527 
  4528 * Pure/Syntax: generic interfaces for type unchecking
  4529 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4530 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4531 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4532 available for convenience, but refer to the very same operations using
  4533 a mere theory instead of a full context.
  4534 
  4535 * Isar: simplified treatment of user-level errors, using exception
  4536 ERROR of string uniformly.  Function error now merely raises ERROR,
  4537 without any side effect on output channels.  The Isar toplevel takes
  4538 care of proper display of ERROR exceptions.  ML code may use plain
  4539 handle/can/try; cat_error may be used to concatenate errors like this:
  4540 
  4541   ... handle ERROR msg => cat_error msg "..."
  4542 
  4543 Toplevel ML code (run directly or through the Isar toplevel) may be
  4544 embedded into the Isar toplevel with exception display/debug like
  4545 this:
  4546 
  4547   Isar.toplevel (fn () => ...)
  4548 
  4549 INCOMPATIBILITY, removed special transform_error facilities, removed
  4550 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4551 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4552 -- use plain ERROR instead.
  4553 
  4554 * Isar: theory setup now has type (theory -> theory), instead of a
  4555 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4556 
  4557 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4558 ProofContext.debug/verbose flags.
  4559 
  4560 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4561 theory before entering a proof state.  Transactions now always see a
  4562 quasi-functional intermediate checkpoint, both in interactive and
  4563 batch mode.
  4564 
  4565 * Isar: simplified interfaces for outer syntax.  Renamed
  4566 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4567 OuterSyntax.add_parsers -- this functionality is now included in
  4568 OuterSyntax.command etc.  INCOMPATIBILITY.
  4569 
  4570 * Simplifier: the simpset of a running simplification process now
  4571 contains a proof context (cf. Simplifier.the_context), which is the
  4572 very context that the initial simpset has been retrieved from (by
  4573 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4574 (solver, looper etc.) may depend on arbitrary proof data.
  4575 
  4576 * Simplifier.inherit_context inherits the proof context (plus the
  4577 local bounds) of the current simplification process; any simproc
  4578 etc. that calls the Simplifier recursively should do this!  Removed
  4579 former Simplifier.inherit_bounds, which is already included here --
  4580 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4581 specify an explicit context using Simplifier.context/theory_context.
  4582 
  4583 * Simplifier/Classical Reasoner: more abstract interfaces
  4584 change_simpset/claset for modifying the simpset/claset reference of a
  4585 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4586 INCOMPATIBILITY.
  4587 
  4588 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4589 "Trueprop" etc.
  4590 
  4591 
  4592 *** System ***
  4593 
  4594 * settings: the default heap location within ISABELLE_HOME_USER now
  4595 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4596 Isabelle installations.
  4597 
  4598 * isabelle-process: option -S (secure mode) disables some critical
  4599 operations, notably runtime compilation and evaluation of ML source
  4600 code.
  4601 
  4602 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4603 
  4604 * Support for parallel execution, using native multicore support of
  4605 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4606 independent theories, according to the given theory header
  4607 specifications. The maximum number of worker threads is specified via
  4608 usedir option -M or the "max-threads" setting in Proof General. A
  4609 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4610 to 6 on a 8-core machine.  User-code needs to observe certain
  4611 guidelines for thread-safe programming, see appendix A in the Isar
  4612 Implementation manual.
  4613 
  4614 
  4615 
  4616 New in Isabelle2005 (October 2005)
  4617 ----------------------------------
  4618 
  4619 *** General ***
  4620 
  4621 * Theory headers: the new header syntax for Isar theories is
  4622 
  4623   theory <name>
  4624   imports <theory1> ... <theoryN>
  4625   uses <file1> ... <fileM>
  4626   begin
  4627 
  4628 where the 'uses' part is optional.  The previous syntax
  4629 
  4630   theory <name> = <theory1> + ... + <theoryN>:
  4631 
  4632 will disappear in the next release.  Use isatool fixheaders to convert
  4633 existing theory files.  Note that there is no change in ancient
  4634 non-Isar theories now, but these will disappear soon.
  4635 
  4636 * Theory loader: parent theories can now also be referred to via
  4637 relative and absolute paths.
  4638 
  4639 * Command 'find_theorems' searches for a list of criteria instead of a
  4640 list of constants. Known criteria are: intro, elim, dest, name:string,
  4641 simp:term, and any term. Criteria can be preceded by '-' to select
  4642 theorems that do not match. Intro, elim, dest select theorems that
  4643 match the current goal, name:s selects theorems whose fully qualified
  4644 name contain s, and simp:term selects all simplification rules whose
  4645 lhs match term.  Any other term is interpreted as pattern and selects
  4646 all theorems matching the pattern. Available in ProofGeneral under
  4647 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4648 
  4649   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4650 
  4651 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4652 matching the current goal as introduction rule and not having "HOL."
  4653 in their name (i.e. not being defined in theory HOL).
  4654 
  4655 * Command 'thms_containing' has been discontinued in favour of
  4656 'find_theorems'; INCOMPATIBILITY.
  4657 
  4658 * Communication with Proof General is now 8bit clean, which means that
  4659 Unicode text in UTF-8 encoding may be used within theory texts (both
  4660 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4661 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4662 
  4663   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4664   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4665 
  4666 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4667 Classical Reasoner.  Typical big applications run around 2 times
  4668 faster.
  4669 
  4670 
  4671 *** Document preparation ***
  4672 
  4673 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4674 of raw sources.  Only those symbols that do not require additional
  4675 LaTeX packages (depending on comments in isabellesym.sty) are
  4676 displayed properly, everything else is left verbatim.  isatool display
  4677 and isatool print are used as front ends (these are subject to the
  4678 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4679 
  4680 * Command tags control specific markup of certain regions of text,
  4681 notably folding and hiding.  Predefined tags include "theory" (for
  4682 theory begin and end), "proof" for proof commands, and "ML" for
  4683 commands involving ML code; the additional tags "visible" and
  4684 "invisible" are unused by default.  Users may give explicit tag
  4685 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4686 interpretation of tags is determined by the LaTeX job during document
  4687 preparation: see option -V of isatool usedir, or options -n and -t of
  4688 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4689 \isadroptag.
  4690 
  4691 Several document versions may be produced at the same time via isatool
  4692 usedir (the generated index.html will link all of them).  Typical
  4693 specifications include ''-V document=theory,proof,ML'' to present
  4694 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4695 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4696 these parts without any formal replacement text.  The Isabelle site
  4697 default settings produce ''document'' and ''outline'' versions as
  4698 specified above.
  4699 
  4700 * Several new antiquotations:
  4701 
  4702   @{term_type term} prints a term with its type annotated;
  4703 
  4704   @{typeof term} prints the type of a term;
  4705 
  4706   @{const const} is the same as @{term const}, but checks that the
  4707   argument is a known logical constant;
  4708 
  4709   @{term_style style term} and @{thm_style style thm} print a term or
  4710   theorem applying a "style" to it
  4711 
  4712   @{ML text}
  4713 
  4714 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4715 definitions, equations, inequations etc., 'concl' printing only the
  4716 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4717 to print the specified premise.  TermStyle.add_style provides an ML
  4718 interface for introducing further styles.  See also the "LaTeX Sugar"
  4719 document practical applications.  The ML antiquotation prints
  4720 type-checked ML expressions verbatim.
  4721 
  4722 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4723 and 'text' support optional locale specification '(in loc)', which
  4724 specifies the default context for interpreting antiquotations.  For
  4725 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4726 
  4727 * Option 'locale=NAME' of antiquotations specifies an alternative
  4728 context interpreting the subsequent argument.  For example: @{thm
  4729 [locale=lattice] inf_assoc}.
  4730 
  4731 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4732 a proof context.
  4733 
  4734 * Proper output of antiquotations for theory commands involving a
  4735 proof context (such as 'locale' or 'theorem (in loc) ...').
  4736 
  4737 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4738 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4739 
  4740 * isatool usedir: new option -C (default true) controls whether option
  4741 -D should include a copy of the original document directory; -C false
  4742 prevents unwanted effects such as copying of administrative CVS data.
  4743 
  4744 
  4745 *** Pure ***
  4746 
  4747 * Considerably improved version of 'constdefs' command.  Now performs
  4748 automatic type-inference of declared constants; additional support for
  4749 local structure declarations (cf. locales and HOL records), see also
  4750 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4751 sequential dependencies of definitions within a single 'constdefs'
  4752 section; moreover, the declared name needs to be an identifier.  If
  4753 all fails, consider to fall back on 'consts' and 'defs' separately.
  4754 
  4755 * Improved indexed syntax and implicit structures.  First of all,
  4756 indexed syntax provides a notational device for subscripted
  4757 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4758 expressions.  Secondly, in a local context with structure
  4759 declarations, number indexes \<^sub>n or the empty index (default
  4760 number 1) refer to a certain fixed variable implicitly; option
  4761 show_structs controls printing of implicit structures.  Typical
  4762 applications of these concepts involve record types and locales.
  4763 
  4764 * New command 'no_syntax' removes grammar declarations (and
  4765 translations) resulting from the given syntax specification, which is
  4766 interpreted in the same manner as for the 'syntax' command.
  4767 
  4768 * 'Advanced' translation functions (parse_translation etc.) may depend
  4769 on the signature of the theory context being presently used for
  4770 parsing/printing, see also isar-ref manual.
  4771 
  4772 * Improved 'oracle' command provides a type-safe interface to turn an
  4773 ML expression of type theory -> T -> term into a primitive rule of
  4774 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4775 is already included here); see also FOL/ex/IffExample.thy;
  4776 INCOMPATIBILITY.
  4777 
  4778 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4779 before); "cI" is no longer bound, use "c.intro" instead.
  4780 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4781 axclasses vs. locales.
  4782 
  4783 * Improved internal renaming of symbolic identifiers -- attach primes
  4784 instead of base 26 numbers.
  4785 
  4786 * New flag show_question_marks controls printing of leading question
  4787 marks in schematic variable names.
  4788 
  4789 * In schematic variable names, *any* symbol following \<^isub> or
  4790 \<^isup> is now treated as part of the base name.  For example, the
  4791 following works without printing of awkward ".0" indexes:
  4792 
  4793   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4794     by simp
  4795 
  4796 * Inner syntax includes (*(*nested*) comments*).
  4797 
  4798 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4799 annotations as "(00...)".
  4800 
  4801 * Clear separation of logical types and nonterminals, where the latter
  4802 may only occur in 'syntax' specifications or type abbreviations.
  4803 Before that distinction was only partially implemented via type class
  4804 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4805 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4806 exotic syntax specifications may require further adaption
  4807 (e.g. Cube/Cube.thy).
  4808 
  4809 * Removed obsolete type class "logic", use the top sort {} instead.
  4810 Note that non-logical types should be declared as 'nonterminals'
  4811 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4812 specifications.
  4813 
  4814 * Attributes 'induct' and 'cases': type or set names may now be
  4815 locally fixed variables as well.
  4816 
  4817 * Simplifier: can now control the depth to which conditional rewriting
  4818 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4819 Limit.
  4820 
  4821 * Simplifier: simplification procedures may now take the current
  4822 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4823 interface), which is very useful for calling the Simplifier
  4824 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4825 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4826 low-level mk_simproc no longer applies Logic.varify internally, to
  4827 allow for use in a context of fixed variables.
  4828 
  4829 * thin_tac now works even if the assumption being deleted contains !!
  4830 or ==>.  More generally, erule now works even if the major premise of
  4831 the elimination rule contains !! or ==>.
  4832 
  4833 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4834 
  4835 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4836 from Pure, which contains all common declarations already.  Both
  4837 theories are defined via plain Isabelle/Isar .thy files.
  4838 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4839 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4840 use isatool fixcpure to adapt your theory and ML sources.
  4841 
  4842 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4843 selections of theorems in named facts via index ranges.
  4844 
  4845 * 'print_theorems': in theory mode, really print the difference
  4846 wrt. the last state (works for interactive theory development only),
  4847 in proof mode print all local facts (cf. 'print_facts');
  4848 
  4849 * 'hide': option '(open)' hides only base names.
  4850 
  4851 * More efficient treatment of intermediate checkpoints in interactive
  4852 theory development.
  4853 
  4854 * Code generator is now invoked via code_module (incremental code
  4855 generation) and code_library (modular code generation, ML structures
  4856 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4857 must be quoted when used as identifiers.
  4858 
  4859 * New 'value' command for reading, evaluating and printing terms using
  4860 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4861 quoted when used as identifier.
  4862 
  4863 
  4864 *** Locales ***
  4865 
  4866 * New commands for the interpretation of locale expressions in
  4867 theories (1), locales (2) and proof contexts (3).  These generate
  4868 proof obligations from the expression specification.  After the
  4869 obligations have been discharged, theorems of the expression are added
  4870 to the theory, target locale or proof context.  The synopsis of the
  4871 commands is a follows:
  4872 
  4873   (1) interpretation expr inst
  4874   (2) interpretation target < expr
  4875   (3) interpret expr inst
  4876 
  4877 Interpretation in theories and proof contexts require a parameter
  4878 instantiation of terms from the current context.  This is applied to
  4879 specifications and theorems of the interpreted expression.
  4880 Interpretation in locales only permits parameter renaming through the
  4881 locale expression.  Interpretation is smart in that interpretations
  4882 that are active already do not occur in proof obligations, neither are
  4883 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4884 inspect active interpretations of a particular locale.  For details,
  4885 see the Isar Reference manual.  Examples can be found in
  4886 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4887 
  4888 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4889 'interpret' instead.
  4890 
  4891 * New context element 'constrains' for adding type constraints to
  4892 parameters.
  4893 
  4894 * Context expressions: renaming of parameters with syntax
  4895 redeclaration.
  4896 
  4897 * Locale declaration: 'includes' disallowed.
  4898 
  4899 * Proper static binding of attribute syntax -- i.e. types / terms /
  4900 facts mentioned as arguments are always those of the locale definition
  4901 context, independently of the context of later invocations.  Moreover,
  4902 locale operations (renaming and type / term instantiation) are applied
  4903 to attribute arguments as expected.
  4904 
  4905 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4906 actual attributes; rare situations may require Attrib.attribute to
  4907 embed those attributes into Attrib.src that lack concrete syntax.
  4908 Attribute implementations need to cooperate properly with the static
  4909 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4910 Attrib.XXX_thm etc. already do the right thing without further
  4911 intervention.  Only unusual applications -- such as "where" or "of"
  4912 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4913 on the context and the facts involved -- may have to assign parsed
  4914 values to argument tokens explicitly.
  4915 
  4916 * Changed parameter management in theorem generation for long goal
  4917 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4918 theorem statement in rare situations.
  4919 
  4920 * Locale inspection command 'print_locale' omits notes elements.  Use
  4921 'print_locale!' to have them included in the output.
  4922 
  4923 
  4924 *** Provers ***
  4925 
  4926 * Provers/hypsubst.ML: improved version of the subst method, for
  4927 single-step rewriting: it now works in bound variable contexts. New is
  4928 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4929 rewrite a different subterm than the original subst method, which is
  4930 still available as 'simplesubst'.
  4931 
  4932 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4933 and quasi orders.
  4934 
  4935 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4936 reflexive-transitive closure of relations.
  4937 
  4938 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4939 limit (previously hard-coded with a value of 20) user-definable.
  4940 
  4941 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4942 is peformed already.  Object-logics merely need to finish their
  4943 initial simpset configuration as before.  INCOMPATIBILITY.
  4944 
  4945 
  4946 *** HOL ***
  4947 
  4948 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4949 
  4950   syntax (epsilon)
  4951     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4952 
  4953 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4954 and x-symbol; use option '-m epsilon' to get it actually printed.
  4955 Moreover, the mathematically important symbolic identifier \<epsilon>
  4956 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4957 
  4958 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4959 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4960 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4961 support corresponding Isar calculations.
  4962 
  4963 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4964 instead of ":".
  4965 
  4966 * theory SetInterval: changed the syntax for open intervals:
  4967 
  4968   Old       New
  4969   {..n(}    {..<n}
  4970   {)n..}    {n<..}
  4971   {m..n(}   {m..<n}
  4972   {)m..n}   {m<..n}
  4973   {)m..n(}  {m<..<n}
  4974 
  4975 The old syntax is still supported but will disappear in the next
  4976 release.  For conversion use the following Emacs search and replace
  4977 patterns (these are not perfect but work quite well):
  4978 
  4979   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4980   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4981 
  4982 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4983 equalities in commutative rings; method 'algebra' provides a generic
  4984 interface.
  4985 
  4986 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4987 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4988 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4989 be a tuple pattern.
  4990 
  4991 Some new syntax forms are available:
  4992 
  4993   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4994   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4995   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4996   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4997 
  4998 The latter form "\<Sum>x < k. e" used to be based on a separate
  4999 function "Summation", which has been discontinued.
  5000 
  5001 * theory Finite_Set: in structured induction proofs, the insert case
  5002 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5003 (insert F x)'.
  5004 
  5005 * The 'refute' command has been extended to support a much larger
  5006 fragment of HOL, including axiomatic type classes, constdefs and
  5007 typedefs, inductive datatypes and recursion.
  5008 
  5009 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5010 Requires zChaff with proof generation to be installed.  See
  5011 HOL/ex/SAT_Examples.thy for examples.
  5012 
  5013 * Datatype induction via method 'induct' now preserves the name of the
  5014 induction variable. For example, when proving P(xs::'a list) by
  5015 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5016 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5017 in unstructured proof scripts.
  5018 
  5019 * Reworked implementation of records.  Improved scalability for
  5020 records with many fields, avoiding performance problems for type
  5021 inference. Records are no longer composed of nested field types, but
  5022 of nested extension types. Therefore the record type only grows linear
  5023 in the number of extensions and not in the number of fields.  The
  5024 top-level (users) view on records is preserved.  Potential
  5025 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5026 old record representation. The type generated for a record is called
  5027 <record_name>_ext_type.
  5028 
  5029 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5030 proofs triggered by a record definition or a simproc (if
  5031 quick_and_dirty is enabled).  Definitions of large records can take
  5032 quite long.
  5033 
  5034 New simproc record_upd_simproc for simplification of multiple record
  5035 updates enabled by default.  Moreover, trivial updates are also
  5036 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5037 occasionally, since simplification is more powerful by default.
  5038 
  5039 * typedef: proper support for polymorphic sets, which contain extra
  5040 type-variables in the term.
  5041 
  5042 * Simplifier: automatically reasons about transitivity chains
  5043 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5044 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5045 old proofs break occasionally as simplification may now solve more
  5046 goals than previously.
  5047 
  5048 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5049 present.  Works for all partial orders (class "order"), in particular
  5050 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5051 just like y <= x.
  5052 
  5053 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5054 bound variable or a constant then the let is unfolded.  Otherwise
  5055 first a is simplified to b, and then f b is simplified to g. If
  5056 possible we abstract b from g arriving at "let x = b in h x",
  5057 otherwise we unfold the let and arrive at g.  The simproc can be
  5058 enabled/disabled by the reference use_let_simproc.  Potential
  5059 INCOMPATIBILITY since simplification is more powerful by default.
  5060 
  5061 * Classical reasoning: the meson method now accepts theorems as arguments.
  5062 
  5063 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5064 jobs to provide advice on the provability of subgoals.
  5065 
  5066 * Theory OrderedGroup and Ring_and_Field: various additions and
  5067 improvements to faciliate calculations involving equalities and
  5068 inequalities.
  5069 
  5070 The following theorems have been eliminated or modified
  5071 (INCOMPATIBILITY):
  5072 
  5073   abs_eq             now named abs_of_nonneg
  5074   abs_of_ge_0        now named abs_of_nonneg
  5075   abs_minus_eq       now named abs_of_nonpos
  5076   imp_abs_id         now named abs_of_nonneg
  5077   imp_abs_neg_id     now named abs_of_nonpos
  5078   mult_pos           now named mult_pos_pos
  5079   mult_pos_le        now named mult_nonneg_nonneg
  5080   mult_pos_neg_le    now named mult_nonneg_nonpos
  5081   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5082   mult_neg           now named mult_neg_neg
  5083   mult_neg_le        now named mult_nonpos_nonpos
  5084 
  5085 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5086      
  5087      zero_le_square
  5088      not_square_less_zero 
  5089 
  5090   The following lemmas have been deleted from Real/RealPow:
  5091   
  5092      realpow_zero_zero
  5093      realpow_two
  5094      realpow_less
  5095      zero_le_power
  5096      realpow_two_le
  5097      abs_realpow_two
  5098      realpow_two_abs     
  5099 
  5100 * Theory Parity: added rules for simplifying exponents.
  5101 
  5102 * Theory List:
  5103 
  5104 The following theorems have been eliminated or modified
  5105 (INCOMPATIBILITY):
  5106 
  5107   list_all_Nil       now named list_all.simps(1)
  5108   list_all_Cons      now named list_all.simps(2)
  5109   list_all_conv      now named list_all_iff
  5110   set_mem_eq         now named mem_iff
  5111 
  5112 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5113 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5114 
  5115 
  5116 *** HOL-Complex ***
  5117 
  5118 * Theory RealDef: better support for embedding natural numbers and
  5119 integers in the reals.
  5120 
  5121 The following theorems have been eliminated or modified
  5122 (INCOMPATIBILITY):
  5123 
  5124   exp_ge_add_one_self  now requires no hypotheses
  5125   real_of_int_add      reversed direction of equality (use [symmetric])
  5126   real_of_int_minus    reversed direction of equality (use [symmetric])
  5127   real_of_int_diff     reversed direction of equality (use [symmetric])
  5128   real_of_int_mult     reversed direction of equality (use [symmetric])
  5129 
  5130 * Theory RComplete: expanded support for floor and ceiling functions.
  5131 
  5132 * Theory Ln is new, with properties of the natural logarithm
  5133 
  5134 * Hyperreal: There is a new type constructor "star" for making
  5135 nonstandard types.  The old type names are now type synonyms:
  5136 
  5137   hypreal = real star
  5138   hypnat = nat star
  5139   hcomplex = complex star
  5140 
  5141 * Hyperreal: Many groups of similarly-defined constants have been
  5142 replaced by polymorphic versions (INCOMPATIBILITY):
  5143 
  5144   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5145 
  5146   starset      <-- starsetNat, starsetC
  5147   *s*          <-- *sNat*, *sc*
  5148   starset_n    <-- starsetNat_n, starsetC_n
  5149   *sn*         <-- *sNatn*, *scn*
  5150   InternalSets <-- InternalNatSets, InternalCSets
  5151 
  5152   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5153   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5154   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5155   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5156   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5157 
  5158 * Hyperreal: Many type-specific theorems have been removed in favor of
  5159 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5160 
  5161   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5162   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5163   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5164   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5165   right_minus <-- hypreal_add_minus
  5166   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5167   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5168   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5169   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5170   mult_1_right <-- hcomplex_mult_one_right
  5171   mult_zero_left <-- hcomplex_mult_zero_left
  5172   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5173   right_distrib <-- hypnat_add_mult_distrib2
  5174   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5175   right_inverse <-- hypreal_mult_inverse
  5176   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5177   order_refl <-- {hypreal,hypnat}_le_refl
  5178   order_trans <-- {hypreal,hypnat}_le_trans
  5179   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5180   order_less_le <-- {hypreal,hypnat}_less_le
  5181   linorder_linear <-- {hypreal,hypnat}_le_linear
  5182   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5183   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5184   add_nonneg_nonneg <-- hypreal_le_add_order
  5185 
  5186 * Hyperreal: Separate theorems having to do with type-specific
  5187 versions of constants have been merged into theorems that apply to the
  5188 new polymorphic constants (INCOMPATIBILITY):
  5189 
  5190   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5191   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5192   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5193   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5194   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5195   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5196   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5197   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5198   STAR_diff <-- {STAR,STARC}_diff
  5199   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5200     STARC_hcomplex_of_complex}_image_subset
  5201   starset_n_Un <-- starset{Nat,C}_n_Un
  5202   starset_n_Int <-- starset{Nat,C}_n_Int
  5203   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5204   starset_n_diff <-- starset{Nat,C}_n_diff
  5205   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5206   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5207   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5208   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5209   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5210   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5211   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5212   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5213   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5214   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5215   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5216   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5217   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5218   starfun_diff <-- starfun{C,RC,CR}_diff
  5219   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5220   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5221   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5222   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5223   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5224   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5225   starfun_Id <-- starfunC_Id
  5226   starfun_approx <-- starfun{Nat,CR}_approx
  5227   starfun_capprox <-- starfun{C,RC}_capprox
  5228   starfun_abs <-- starfunNat_rabs
  5229   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5230   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5231   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5232   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5233   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5234   starfun_add_approx <-- starfunCR_add_approx
  5235   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5236   starfun_divide <-- starfun{C,CR,RC}_divide
  5237   starfun_n <-- starfun{Nat,C}_n
  5238   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5239   starfun_n_add <-- starfun{Nat,C}_n_add
  5240   starfun_n_add_minus <-- starfunNat_n_add_minus
  5241   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5242   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5243   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5244 
  5245   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5246   star_n_minus <-- {hypreal,hcomplex}_minus
  5247   star_n_diff <-- {hypreal,hcomplex}_diff
  5248   star_n_mult <-- {hypreal,hcomplex}_mult
  5249   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5250   star_n_le <-- {hypreal,hypnat}_le
  5251   star_n_less <-- {hypreal,hypnat}_less
  5252   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5253   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5254   star_n_abs <-- hypreal_hrabs
  5255   star_n_divide <-- hcomplex_divide
  5256 
  5257   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5258   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5259   star_of_diff <-- hypreal_of_real_diff
  5260   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5261   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5262   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5263   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5264   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5265   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5266   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5267   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5268   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5269   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5270   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5271   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5272   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5273   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5274   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5275   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5276   star_of_power <-- hypreal_of_real_power
  5277   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5278 
  5279 * Hyperreal: new method "transfer" that implements the transfer
  5280 principle of nonstandard analysis. With a subgoal that mentions
  5281 nonstandard types like "'a star", the command "apply transfer"
  5282 replaces it with an equivalent one that mentions only standard types.
  5283 To be successful, all free variables must have standard types; non-
  5284 standard variables must have explicit universal quantifiers.
  5285 
  5286 * Hyperreal: A theory of Taylor series.
  5287 
  5288 
  5289 *** HOLCF ***
  5290 
  5291 * Discontinued special version of 'constdefs' (which used to support
  5292 continuous functions) in favor of the general Pure one with full
  5293 type-inference.
  5294 
  5295 * New simplification procedure for solving continuity conditions; it
  5296 is much faster on terms with many nested lambda abstractions (cubic
  5297 instead of exponential time).
  5298 
  5299 * New syntax for domain package: selector names are now optional.
  5300 Parentheses should be omitted unless argument is lazy, for example:
  5301 
  5302   domain 'a stream = cons "'a" (lazy "'a stream")
  5303 
  5304 * New command 'fixrec' for defining recursive functions with pattern
  5305 matching; defining multiple functions with mutual recursion is also
  5306 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5307 sinr, or any data constructor defined by the domain package. The given
  5308 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5309 syntax and examples.
  5310 
  5311 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5312 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5313 but the proof obligation additionally includes an admissibility
  5314 requirement. The packages generate instances of class cpo or pcpo,
  5315 with continuity and strictness theorems for Rep and Abs.
  5316 
  5317 * HOLCF: Many theorems have been renamed according to a more standard naming
  5318 scheme (INCOMPATIBILITY):
  5319 
  5320   foo_inject:  "foo$x = foo$y ==> x = y"
  5321   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5322   foo_less:    "(foo$x << foo$y) = (x << y)"
  5323   foo_strict:  "foo$UU = UU"
  5324   foo_defined: "... ==> foo$x ~= UU"
  5325   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5326 
  5327 
  5328 *** ZF ***
  5329 
  5330 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5331 including the First Isomorphism Theorem (on quotienting by the kernel
  5332 of a homomorphism).
  5333 
  5334 * ZF/Simplifier: install second copy of type solver that actually
  5335 makes use of TC rules declared to Isar proof contexts (or locales);
  5336 the old version is still required for ML proof scripts.
  5337 
  5338 
  5339 *** Cube ***
  5340 
  5341 * Converted to Isar theory format; use locales instead of axiomatic
  5342 theories.
  5343 
  5344 
  5345 *** ML ***
  5346 
  5347 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5348 for ||>, ||>>, |>>,
  5349 
  5350 * Pure/library.ML no longer defines its own option datatype, but uses
  5351 that of the SML basis, which has constructors NONE and SOME instead of
  5352 None and Some, as well as exception Option.Option instead of OPTION.
  5353 The functions the, if_none, is_some, is_none have been adapted
  5354 accordingly, while Option.map replaces apsome.
  5355 
  5356 * Pure/library.ML: the exception LIST has been given up in favour of
  5357 the standard exceptions Empty and Subscript, as well as
  5358 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5359 superceded by the standard hd and tl functions etc.
  5360 
  5361 A number of basic list functions are no longer exported to the ML
  5362 toplevel, as they are variants of predefined functions.  The following
  5363 suggests how one can translate existing code:
  5364 
  5365     rev_append xs ys = List.revAppend (xs, ys)
  5366     nth_elem (i, xs) = List.nth (xs, i)
  5367     last_elem xs = List.last xs
  5368     flat xss = List.concat xss
  5369     seq fs = List.app fs
  5370     partition P xs = List.partition P xs
  5371     mapfilter f xs = List.mapPartial f xs
  5372 
  5373 * Pure/library.ML: several combinators for linear functional
  5374 transformations, notably reverse application and composition:
  5375 
  5376   x |> f                f #> g
  5377   (x, y) |-> f          f #-> g
  5378 
  5379 * Pure/library.ML: introduced/changed precedence of infix operators:
  5380 
  5381   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5382   infix 2 ?;
  5383   infix 3 o oo ooo oooo;
  5384   infix 4 ~~ upto downto;
  5385 
  5386 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5387 infix operators.
  5388 
  5389 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5390 fold_map support linear functional transformations and nesting.  For
  5391 example:
  5392 
  5393   fold f [x1, ..., xN] y =
  5394     y |> f x1 |> ... |> f xN
  5395 
  5396   (fold o fold) f [xs1, ..., xsN] y =
  5397     y |> fold f xs1 |> ... |> fold f xsN
  5398 
  5399   fold f [x1, ..., xN] =
  5400     f x1 #> ... #> f xN
  5401 
  5402   (fold o fold) f [xs1, ..., xsN] =
  5403     fold f xs1 #> ... #> fold f xsN
  5404 
  5405 * Pure/library.ML: the following selectors on type 'a option are
  5406 available:
  5407 
  5408   the:               'a option -> 'a  (*partial*)
  5409   these:             'a option -> 'a  where 'a = 'b list
  5410   the_default: 'a -> 'a option -> 'a
  5411   the_list:          'a option -> 'a list
  5412 
  5413 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5414 basic operations for association lists, following natural argument
  5415 order; moreover the explicit equality predicate passed here avoids
  5416 potentially expensive polymorphic runtime equality checks.
  5417 The old functions may be expressed as follows:
  5418 
  5419   assoc = uncurry (AList.lookup (op =))
  5420   assocs = these oo AList.lookup (op =)
  5421   overwrite = uncurry (AList.update (op =)) o swap
  5422 
  5423 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5424 
  5425   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5426   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5427 
  5428 replacing make_keylist and keyfilter (occassionally used)
  5429 Naive rewrites:
  5430 
  5431   make_keylist = AList.make
  5432   keyfilter = AList.find (op =)
  5433 
  5434 * eq_fst and eq_snd now take explicit equality parameter, thus
  5435   avoiding eqtypes. Naive rewrites:
  5436 
  5437     eq_fst = eq_fst (op =)
  5438     eq_snd = eq_snd (op =)
  5439 
  5440 * Removed deprecated apl and apr (rarely used).
  5441   Naive rewrites:
  5442 
  5443     apl (n, op) =>>= curry op n
  5444     apr (op, m) =>>= fn n => op (n, m)
  5445 
  5446 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5447 provides a reasonably efficient light-weight implementation of sets as
  5448 lists.
  5449 
  5450 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5451 few new operations; existing lookup and update are now curried to
  5452 follow natural argument order (for use with fold etc.);
  5453 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5454 
  5455 * Pure/General: output via the Isabelle channels of
  5456 writeln/warning/error etc. is now passed through Output.output, with a
  5457 hook for arbitrary transformations depending on the print_mode
  5458 (cf. Output.add_mode -- the first active mode that provides a output
  5459 function wins).  Already formatted output may be embedded into further
  5460 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5461 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5462 accommodate easy composition of diagnostic messages etc.  Programmers
  5463 rarely need to care about Output.output or Output.raw at all, with
  5464 some notable exceptions: Output.output is required when bypassing the
  5465 standard channels (writeln etc.), or in token translations to produce
  5466 properly formatted results; Output.raw is required when capturing
  5467 already output material that will eventually be presented to the user
  5468 a second time.  For the default print mode, both Output.output and
  5469 Output.raw have no effect.
  5470 
  5471 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5472 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5473 cumulative results are displayed at the end of a batch session.
  5474 
  5475 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5476 replaced by File.platform_path and File.shell_path (with appropriate
  5477 hooks).  This provides a clean interface for unusual systems where the
  5478 internal and external process view of file names are different.
  5479 
  5480 * Pure: more efficient orders for basic syntactic entities: added
  5481 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5482 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5483 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5484 orders now -- potential INCOMPATIBILITY for code that depends on a
  5485 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5486 Library.sort_strings on result).
  5487 
  5488 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5489 fold_types traverse types/terms from left to right, observing natural
  5490 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5491 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5492 
  5493 * Pure: name spaces have been refined, with significant changes of the
  5494 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5495 to extern(_table).  The plain name entry path is superceded by a
  5496 general 'naming' context, which also includes the 'policy' to produce
  5497 a fully qualified name and external accesses of a fully qualified
  5498 name; NameSpace.extend is superceded by context dependent
  5499 Sign.declare_name.  Several theory and proof context operations modify
  5500 the naming context.  Especially note Theory.restore_naming and
  5501 ProofContext.restore_naming to get back to a sane state; note that
  5502 Theory.add_path is no longer sufficient to recover from
  5503 Theory.absolute_path in particular.
  5504 
  5505 * Pure: new flags short_names (default false) and unique_names
  5506 (default true) for controlling output of qualified names.  If
  5507 short_names is set, names are printed unqualified.  If unique_names is
  5508 reset, the name prefix is reduced to the minimum required to achieve
  5509 the original result when interning again, even if there is an overlap
  5510 with earlier declarations.
  5511 
  5512 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5513 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5514 (useful for printing error messages).  INCOMPATIBILITY.
  5515 
  5516 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5517 Theory.theory are now identified, referring to the universal
  5518 Context.theory (see Pure/context.ML).  Actual signature and theory
  5519 content is managed as theory data.  The old code and interfaces were
  5520 spread over many files and structures; the new arrangement introduces
  5521 considerable INCOMPATIBILITY to gain more clarity:
  5522 
  5523   Context -- theory management operations (name, identity, inclusion,
  5524     parents, ancestors, merge, etc.), plus generic theory data;
  5525 
  5526   Sign -- logical signature and syntax operations (declaring consts,
  5527     types, etc.), plus certify/read for common entities;
  5528 
  5529   Theory -- logical theory operations (stating axioms, definitions,
  5530     oracles), plus a copy of logical signature operations (consts,
  5531     types, etc.); also a few basic management operations (Theory.copy,
  5532     Theory.merge, etc.)
  5533 
  5534 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5535 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5536 for convenience -- they merely return the theory.
  5537 
  5538 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5539 
  5540 * Pure: the Isar proof context type is already defined early in Pure
  5541 as Context.proof (note that ProofContext.context and Proof.context are
  5542 aliases, where the latter is the preferred name).  This enables other
  5543 Isabelle components to refer to that type even before Isar is present.
  5544 
  5545 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5546 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5547 any of these kinds.  For example, Sign.intern typeK is now
  5548 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5549 Theory.hide_types.  Also note that former
  5550 Theory.hide_classes/types/consts are now
  5551 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5552 internalize their arguments!  INCOMPATIBILITY.
  5553 
  5554 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5555 datatype thmref (with constructors Name and NameSelection) instead of
  5556 plain string -- INCOMPATIBILITY;
  5557 
  5558 * Pure: cases produced by proof methods specify options, where NONE
  5559 means to remove case bindings -- INCOMPATIBILITY in
  5560 (RAW_)METHOD_CASES.
  5561 
  5562 * Pure: the following operations retrieve axioms or theorems from a
  5563 theory node or theory hierarchy, respectively:
  5564 
  5565   Theory.axioms_of: theory -> (string * term) list
  5566   Theory.all_axioms_of: theory -> (string * term) list
  5567   PureThy.thms_of: theory -> (string * thm) list
  5568   PureThy.all_thms_of: theory -> (string * thm) list
  5569 
  5570 * Pure: print_tac now outputs the goal through the trace channel.
  5571 
  5572 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5573 Reference Toplevel.debug (default false) controls detailed printing
  5574 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5575 controls execution profiling -- set to 1 for time and 2 for space
  5576 (both increase the runtime).
  5577 
  5578 * Isar session: The initial use of ROOT.ML is now always timed,
  5579 i.e. the log will show the actual process times, in contrast to the
  5580 elapsed wall-clock time that the outer shell wrapper produces.
  5581 
  5582 * Simplifier: improved handling of bound variables (nameless
  5583 representation, avoid allocating new strings).  Simprocs that invoke
  5584 the Simplifier recursively should use Simplifier.inherit_bounds to
  5585 avoid local name clashes.  Failure to do so produces warnings
  5586 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5587 for further details.
  5588 
  5589 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5590 bindings for all theorems stored within a given theory; this may help
  5591 in porting non-Isar theories to Isar ones, while keeping ML proof
  5592 scripts for the time being.
  5593 
  5594 * ML operator HTML.with_charset specifies the charset begin used for
  5595 generated HTML files.  For example:
  5596 
  5597   HTML.with_charset "utf-8" use_thy "Hebrew";
  5598   HTML.with_charset "utf-8" use_thy "Chinese";
  5599 
  5600 
  5601 *** System ***
  5602 
  5603 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5604 isabelle, isatool etc.).
  5605 
  5606 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5607 isatool doc, isatool mkdir, display_drafts etc.).
  5608 
  5609 * isatool usedir: option -f allows specification of the ML file to be
  5610 used by Isabelle; default is ROOT.ML.
  5611 
  5612 * New isatool version outputs the version identifier of the Isabelle
  5613 distribution being used.
  5614 
  5615 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5616 (containing Boolean satisfiability problems) into Isabelle/HOL
  5617 theories.
  5618 
  5619 
  5620 
  5621 New in Isabelle2004 (April 2004)
  5622 --------------------------------
  5623 
  5624 *** General ***
  5625 
  5626 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5627   Replaces linorder.ML.
  5628 
  5629 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5630   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5631   (\<a>...\<z>), are now considered normal letters, and can therefore
  5632   be used anywhere where an ASCII letter (a...zA...Z) has until
  5633   now. COMPATIBILITY: This obviously changes the parsing of some
  5634   terms, especially where a symbol has been used as a binder, say
  5635   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5636   as an identifier.  Fix it by inserting a space around former
  5637   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5638   existing theory and ML files.
  5639 
  5640 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5641 
  5642 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5643   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5644   a normal (but invisible) letter. For multiple letter subscripts repeat
  5645   \<^isub> like this: x\<^isub>1\<^isub>2.
  5646 
  5647 * Pure: There are now sub-/superscripts that can span more than one
  5648   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5649   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5650   superscript. The new control characters are not identifier parts.
  5651 
  5652 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5653   content of "..." to the latex file instead of \isacntrl... . The "..."
  5654   may consist of any printable characters excluding the end bracket >.
  5655 
  5656 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5657   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5658   declare constants "final", which prevents their being given a definition
  5659   later.  It is useful for constants whose behaviour is fixed axiomatically
  5660   rather than definitionally, such as the meta-logic connectives.
  5661 
  5662 * Pure: 'instance' now handles general arities with general sorts
  5663   (i.e. intersections of classes),
  5664 
  5665 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5666   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5667   It can be changed to alter the colors/layout of generated pages.
  5668 
  5669 
  5670 *** Isar ***
  5671 
  5672 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5673   cut_tac, subgoal_tac and thin_tac:
  5674   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5675     locales are no longer forced to write Isar proof scripts.
  5676     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5677     emulations.
  5678   - INCOMPATIBILITY: names of variables to be instantiated may no
  5679     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5680     This is consistent with the instantiation attribute "where".
  5681 
  5682 * Attributes "where" and "of":
  5683   - Now take type variables of instantiated theorem into account when reading
  5684     the instantiation string.  This fixes a bug that caused instantiated
  5685     theorems to have too special types in some circumstances.
  5686   - "where" permits explicit instantiations of type variables.
  5687 
  5688 * Calculation commands "moreover" and "also" no longer interfere with
  5689   current facts ("this"), admitting arbitrary combinations with "then"
  5690   and derived forms.
  5691 
  5692 * Locales:
  5693   - Goal statements involving the context element "includes" no longer
  5694     generate theorems with internal delta predicates (those ending on
  5695     "_axioms") in the premise.
  5696     Resolve particular premise with <locale>.intro to obtain old form.
  5697   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5698     specification and "includes" elements in goal statement.
  5699   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5700     [intro?] and [elim?] (respectively) by default.
  5701   - Experimental command for instantiation of locales in proof contexts:
  5702         instantiate <label>[<attrs>]: <loc>
  5703     Instantiates locale <loc> and adds all its theorems to the current context
  5704     taking into account their attributes.  Label and attrs are optional
  5705     modifiers, like in theorem declarations.  If present, names of
  5706     instantiated theorems are qualified with <label>, and the attributes
  5707     <attrs> are applied after any attributes these theorems might have already.
  5708       If the locale has assumptions, a chained fact of the form
  5709     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5710     are derived.  The command does not support old-style locales declared
  5711     with "locale (open)".
  5712       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5713 
  5714 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5715   (Isar) contexts.
  5716 
  5717 
  5718 *** HOL ***
  5719 
  5720 * Proof import: new image HOL4 contains the imported library from
  5721   the HOL4 system with about 2500 theorems. It is imported by
  5722   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5723   can be used like any other Isabelle image.  See
  5724   HOL/Import/HOL/README for more information.
  5725 
  5726 * Simplifier:
  5727   - Much improved handling of linear and partial orders.
  5728     Reasoners for linear and partial orders are set up for type classes
  5729     "linorder" and "order" respectively, and are added to the default simpset
  5730     as solvers.  This means that the simplifier can build transitivity chains
  5731     to solve goals from the assumptions.
  5732   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5733     of blast or auto after simplification become unnecessary because the goal
  5734     is solved by simplification already.
  5735 
  5736 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5737     all proved in axiomatic type classes for semirings, rings and fields.
  5738 
  5739 * Numerics:
  5740   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5741     now formalized using the Ring_and_Field theory mentioned above.
  5742   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5743     than before, because now they are set up once in a generic manner.
  5744   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5745     Look for the general versions in Ring_and_Field (and Power if they concern
  5746     exponentiation).
  5747 
  5748 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5749 
  5750 * Records:
  5751   - Record types are now by default printed with their type abbreviation
  5752     instead of the list of all field types. This can be configured via
  5753     the reference "print_record_type_abbr".
  5754   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5755     (not enabled by default).
  5756   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5757     EX x. x = sel r to True (not enabled by default).
  5758   - Tactic "record_split_simp_tac" to split and simplify records added.
  5759 
  5760 * 'specification' command added, allowing for definition by
  5761   specification.  There is also an 'ax_specification' command that
  5762   introduces the new constants axiomatically.
  5763 
  5764 * arith(_tac) is now able to generate counterexamples for reals as well.
  5765 
  5766 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5767 
  5768 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5769   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5770 
  5771 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5772   matrix theory to linear programming.
  5773 
  5774 * Unions and Intersections:
  5775   The latex output syntax of UN and INT has been changed
  5776   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5777   i.e. the index formulae has become a subscript.
  5778   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5779 
  5780 * Unions and Intersections over Intervals:
  5781   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5782   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5783   like in normal math, and corresponding versions for < and for intersection.
  5784 
  5785 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5786   lexicographic dictonary ordering has been added as "lexord".
  5787 
  5788 * ML: the legacy theory structures Int and List have been removed. They had
  5789   conflicted with ML Basis Library structures having the same names.
  5790 
  5791 * 'refute' command added to search for (finite) countermodels.  Only works
  5792   for a fragment of HOL.  The installation of an external SAT solver is
  5793   highly recommended.  See "HOL/Refute.thy" for details.
  5794 
  5795 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5796   formulae under an assignment of free variables to random values.
  5797   In contrast to 'refute', it can deal with inductive datatypes,
  5798   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5799   for examples.
  5800 
  5801 
  5802 *** HOLCF ***
  5803 
  5804 * Streams now come with concatenation and are part of the HOLCF image
  5805 
  5806 
  5807 
  5808 New in Isabelle2003 (May 2003)
  5809 ------------------------------
  5810 
  5811 *** General ***
  5812 
  5813 * Provers/simplifier:
  5814 
  5815   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5816     Assumptions are now subject to complete mutual simplification,
  5817     not just from left to right. The simplifier now preserves
  5818     the order of assumptions.
  5819 
  5820     Potential INCOMPATIBILITY:
  5821 
  5822     -- simp sometimes diverges where the old version did
  5823        not, e.g. invoking simp on the goal
  5824 
  5825         [| P (f x); y = x; f x = f y |] ==> Q
  5826 
  5827        now gives rise to the infinite reduction sequence
  5828 
  5829         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5830 
  5831        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5832        kind of problem.
  5833 
  5834     -- Tactics combining classical reasoner and simplification (such as auto)
  5835        are also affected by this change, because many of them rely on
  5836        simp. They may sometimes diverge as well or yield a different numbers
  5837        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5838        in case of problems. Sometimes subsequent calls to the classical
  5839        reasoner will fail because a preceeding call to the simplifier too
  5840        eagerly simplified the goal, e.g. deleted redundant premises.
  5841 
  5842   - The simplifier trace now shows the names of the applied rewrite rules
  5843 
  5844   - You can limit the number of recursive invocations of the simplifier
  5845     during conditional rewriting (where the simplifie tries to solve the
  5846     conditions before applying the rewrite rule):
  5847     ML "simp_depth_limit := n"
  5848     where n is an integer. Thus you can force termination where previously
  5849     the simplifier would diverge.
  5850 
  5851   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5852 
  5853   - No longer aborts on failed congruence proof.  Instead, the
  5854     congruence is ignored.
  5855 
  5856 * Pure: New generic framework for extracting programs from constructive
  5857   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5858   as HOL/Extraction for some case studies.
  5859 
  5860 * Pure: The main goal of the proof state is no longer shown by default, only
  5861 the subgoals. This behaviour is controlled by a new flag.
  5862    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5863 (ML: Proof.show_main_goal).
  5864 
  5865 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5866 rules whose conclusion matches subgoal 1:
  5867       PG menu: Isabelle/Isar -> Show me -> matching rules
  5868 The rules are ordered by how closely they match the subgoal.
  5869 In particular, rules that solve a subgoal outright are displayed first
  5870 (or rather last, the way they are printed).
  5871 (ML: ProofGeneral.print_intros())
  5872 
  5873 * Pure: New flag trace_unify_fail causes unification to print
  5874 diagnostic information (PG: in trace buffer) when it fails. This is
  5875 useful for figuring out why single step proofs like rule, erule or
  5876 assumption failed.
  5877 
  5878 * Pure: Locale specifications now produce predicate definitions
  5879 according to the body of text (covering assumptions modulo local
  5880 definitions); predicate "loc_axioms" covers newly introduced text,
  5881 while "loc" is cumulative wrt. all included locale expressions; the
  5882 latter view is presented only on export into the global theory
  5883 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5884 on the old view without predicates;
  5885 
  5886 * Pure: predefined locales "var" and "struct" are useful for sharing
  5887 parameters (as in CASL, for example); just specify something like
  5888 ``var x + var y + struct M'' as import;
  5889 
  5890 * Pure: improved thms_containing: proper indexing of facts instead of
  5891 raw theorems; check validity of results wrt. current name space;
  5892 include local facts of proof configuration (also covers active
  5893 locales), cover fixed variables in index; may use "_" in term
  5894 specification; an optional limit for the number of printed facts may
  5895 be given (the default is 40);
  5896 
  5897 * Pure: disallow duplicate fact bindings within new-style theory files
  5898 (batch-mode only);
  5899 
  5900 * Provers: improved induct method: assumptions introduced by case
  5901 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5902 the goal statement); "foo" still refers to all facts collectively;
  5903 
  5904 * Provers: the function blast.overloaded has been removed: all constants
  5905 are regarded as potentially overloaded, which improves robustness in exchange
  5906 for slight decrease in efficiency;
  5907 
  5908 * Provers/linorder: New generic prover for transitivity reasoning over
  5909 linear orders.  Note: this prover is not efficient!
  5910 
  5911 * Isar: preview of problems to finish 'show' now produce an error
  5912 rather than just a warning (in interactive mode);
  5913 
  5914 
  5915 *** HOL ***
  5916 
  5917 * arith(_tac)
  5918 
  5919  - Produces a counter example if it cannot prove a goal.
  5920    Note that the counter example may be spurious if the goal is not a formula
  5921    of quantifier-free linear arithmetic.
  5922    In ProofGeneral the counter example appears in the trace buffer.
  5923 
  5924  - Knows about div k and mod k where k is a numeral of type nat or int.
  5925 
  5926  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5927    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5928    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5929 
  5930 * simp's arithmetic capabilities have been enhanced a bit: it now
  5931 takes ~= in premises into account (by performing a case split);
  5932 
  5933 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5934 are distributed over a sum of terms;
  5935 
  5936 * New tactic "trans_tac" and method "trans" instantiate
  5937 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5938 "<=", "<" and "=").
  5939 
  5940 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5941 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5942 
  5943 * 'typedef' command has new option "open" to suppress the set
  5944 definition;
  5945 
  5946 * functions Min and Max on finite sets have been introduced (theory
  5947 Finite_Set);
  5948 
  5949 * attribute [symmetric] now works for relations as well; it turns
  5950 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5951 
  5952 * induct over a !!-quantified statement (say !!x1..xn):
  5953   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5954 
  5955 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5956 %x. None. Warning: empty_def now refers to the previously hidden definition
  5957 of the empty set.
  5958 
  5959 * Algebra: formalization of classical algebra.  Intended as base for
  5960 any algebraic development in Isabelle.  Currently covers group theory
  5961 (up to Sylow's theorem) and ring theory (Universal Property of
  5962 Univariate Polynomials).  Contributions welcome;
  5963 
  5964 * GroupTheory: deleted, since its material has been moved to Algebra;
  5965 
  5966 * Complex: new directory of the complex numbers with numeric constants,
  5967 nonstandard complex numbers, and some complex analysis, standard and
  5968 nonstandard (Jacques Fleuriot);
  5969 
  5970 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5971 
  5972 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5973 Fleuriot);
  5974 
  5975 * Real/HahnBanach: updated and adapted to locales;
  5976 
  5977 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5978 Gray and Kramer);
  5979 
  5980 * UNITY: added the Meier-Sanders theory of progress sets;
  5981 
  5982 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5983 as abstract algorithms, instantiated to the JVM;
  5984 
  5985 * Bali: Java source language formalization. Type system, operational
  5986 semantics, axiomatic semantics. Supported language features:
  5987 classes, interfaces, objects,virtual methods, static methods,
  5988 static/instance fields, arrays, access modifiers, definite
  5989 assignment, exceptions.
  5990 
  5991 
  5992 *** ZF ***
  5993 
  5994 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5995 universe, etc.);
  5996 
  5997 * Main ZF: virtually all theories converted to new-style format;
  5998 
  5999 
  6000 *** ML ***
  6001 
  6002 * Pure: Tactic.prove provides sane interface for internal proofs;
  6003 omits the infamous "standard" operation, so this is more appropriate
  6004 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6005 
  6006 * Pure: improved error reporting of simprocs;
  6007 
  6008 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6009 up simprocs;
  6010 
  6011 
  6012 *** Document preparation ***
  6013 
  6014 * uses \par instead of \\ for line breaks in theory text. This may
  6015 shift some page breaks in large documents. To get the old behaviour
  6016 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6017 
  6018 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6019 other packages
  6020 
  6021 * \<euro> now needs package babel/greek instead of marvosym (which
  6022 broke \Rightarrow)
  6023 
  6024 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6025 textcomp package)
  6026 
  6027 
  6028 
  6029 New in Isabelle2002 (March 2002)
  6030 --------------------------------
  6031 
  6032 *** Document preparation ***
  6033 
  6034 * greatly simplified document preparation setup, including more
  6035 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6036 instructive isatool mkdir; users should basically be able to get
  6037 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6038 users may run a separate document processing stage manually like this:
  6039 "isatool usedir -D output HOL Test && isatool document Test/output";
  6040 
  6041 * theory dependency graph may now be incorporated into documents;
  6042 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6043 with \includegraphics of LaTeX;
  6044 
  6045 * proper spacing of consecutive markup elements, especially text
  6046 blocks after section headings;
  6047 
  6048 * support bold style (for single symbols only), input syntax is like
  6049 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6050 
  6051 * \<bullet> is now output as bold \cdot by default, which looks much
  6052 better in printed text;
  6053 
  6054 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6055 note that these symbols are currently unavailable in Proof General /
  6056 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6057 
  6058 * isatool latex no longer depends on changed TEXINPUTS, instead
  6059 isatool document copies the Isabelle style files to the target
  6060 location;
  6061 
  6062 
  6063 *** Isar ***
  6064 
  6065 * Pure/Provers: improved proof by cases and induction;
  6066   - 'case' command admits impromptu naming of parameters (such as
  6067     "case (Suc n)");
  6068   - 'induct' method divinates rule instantiation from the inductive
  6069     claim; no longer requires excessive ?P bindings for proper
  6070     instantiation of cases;
  6071   - 'induct' method properly enumerates all possibilities of set/type
  6072     rules; as a consequence facts may be also passed through *type*
  6073     rules without further ado;
  6074   - 'induct' method now derives symbolic cases from the *rulified*
  6075     rule (before it used to rulify cases stemming from the internal
  6076     atomized version); this means that the context of a non-atomic
  6077     statement becomes is included in the hypothesis, avoiding the
  6078     slightly cumbersome show "PROP ?case" form;
  6079   - 'induct' may now use elim-style induction rules without chaining
  6080     facts, using ``missing'' premises from the goal state; this allows
  6081     rules stemming from inductive sets to be applied in unstructured
  6082     scripts, while still benefitting from proper handling of non-atomic
  6083     statements; NB: major inductive premises need to be put first, all
  6084     the rest of the goal is passed through the induction;
  6085   - 'induct' proper support for mutual induction involving non-atomic
  6086     rule statements (uses the new concept of simultaneous goals, see
  6087     below);
  6088   - append all possible rule selections, but only use the first
  6089     success (no backtracking);
  6090   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6091   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6092   - added 'print_induct_rules' (covered by help item in recent Proof
  6093     General versions);
  6094   - moved induct/cases attributes to Pure, methods to Provers;
  6095   - generic method setup instantiated for FOL and HOL;
  6096 
  6097 * Pure: support multiple simultaneous goal statements, for example
  6098 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6099 meta-level mechanism, this acts as if several individual goals had
  6100 been stated separately; in particular common proof methods need to be
  6101 repeated in order to cover all claims; note that a single elimination
  6102 step is *not* sufficient to establish the two conjunctions, so this
  6103 fails:
  6104 
  6105   assume "A & B" then have A and B ..   (*".." fails*)
  6106 
  6107 better use "obtain" in situations as above; alternative refer to
  6108 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6109 
  6110 * Pure: proper integration with ``locales''; unlike the original
  6111 version by Florian Kammller, Isar locales package high-level proof
  6112 contexts rather than raw logical ones (e.g. we admit to include
  6113 attributes everywhere); operations on locales include merge and
  6114 rename; support for implicit arguments (``structures''); simultaneous
  6115 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6116 some examples;
  6117 
  6118 * Pure: the following commands have been ``localized'', supporting a
  6119 target locale specification "(in name)": 'lemma', 'theorem',
  6120 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6121 stored both within the locale and at the theory level (exported and
  6122 qualified by the locale name);
  6123 
  6124 * Pure: theory goals may now be specified in ``long'' form, with
  6125 ad-hoc contexts consisting of arbitrary locale elements. for example
  6126 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6127 definitions may be given, too); the result is a meta-level rule with
  6128 the context elements being discharged in the obvious way;
  6129 
  6130 * Pure: new proof command 'using' allows to augment currently used
  6131 facts after a goal statement ('using' is syntactically analogous to
  6132 'apply', but acts on the goal's facts only); this allows chained facts
  6133 to be separated into parts given before and after a claim, as in
  6134 ``from a and b have C using d and e <proof>'';
  6135 
  6136 * Pure: renamed "antecedent" case to "rule_context";
  6137 
  6138 * Pure: new 'judgment' command records explicit information about the
  6139 object-logic embedding (used by several tools internally); no longer
  6140 use hard-wired "Trueprop";
  6141 
  6142 * Pure: added 'corollary' command;
  6143 
  6144 * Pure: fixed 'token_translation' command;
  6145 
  6146 * Pure: removed obsolete 'exported' attribute;
  6147 
  6148 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6149 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6150 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6151 
  6152 * Pure: method 'atomize' presents local goal premises as object-level
  6153 statements (atomic meta-level propositions); setup controlled via
  6154 rewrite rules declarations of 'atomize' attribute; example
  6155 application: 'induct' method with proper rule statements in improper
  6156 proof *scripts*;
  6157 
  6158 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6159 now consider the syntactic context of assumptions, giving a better
  6160 chance to get type-inference of the arguments right (this is
  6161 especially important for locales);
  6162 
  6163 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6164 mode;
  6165 
  6166 * Pure/obtain: the formal conclusion "thesis", being marked as
  6167 ``internal'', may no longer be reference directly in the text;
  6168 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6169 situations;
  6170 
  6171 * Pure: generic 'sym' attribute which declares a rule both as pure
  6172 'elim?' and for the 'symmetric' operation;
  6173 
  6174 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6175 text; the fixed correlation with particular command syntax has been
  6176 discontinued;
  6177 
  6178 * Pure: new method 'rules' is particularly well-suited for proof
  6179 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6180 but often produces more compact proof terms with less detours;
  6181 
  6182 * Pure/Provers/classical: simplified integration with pure rule
  6183 attributes and methods; the classical "intro?/elim?/dest?"
  6184 declarations coincide with the pure ones; the "rule" method no longer
  6185 includes classically swapped intros; "intro" and "elim" methods no
  6186 longer pick rules from the context; also got rid of ML declarations
  6187 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6188 INCOMPATIBILITY;
  6189 
  6190 * Provers/classical: attribute 'swapped' produces classical inversions
  6191 of introduction rules;
  6192 
  6193 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6194 rules instead of full simplifier context; 'iff' attribute handles
  6195 conditional rules;
  6196 
  6197 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6198 
  6199 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6200 "(permissive)" option to recover old behavior;
  6201 
  6202 * HOL: 'inductive' no longer features separate (collective) attributes
  6203 for 'intros' (was found too confusing);
  6204 
  6205 * HOL: properly declared induction rules less_induct and
  6206 wf_induct_rule;
  6207 
  6208 
  6209 *** HOL ***
  6210 
  6211 * HOL: moved over to sane numeral syntax; the new policy is as
  6212 follows:
  6213 
  6214   - 0 and 1 are polymorphic constants, which are defined on any
  6215   numeric type (nat, int, real etc.);
  6216 
  6217   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6218   binary representation internally;
  6219 
  6220   - type nat has special constructor Suc, and generally prefers Suc 0
  6221   over 1::nat and Suc (Suc 0) over 2::nat;
  6222 
  6223 This change may cause significant problems of INCOMPATIBILITY; here
  6224 are some hints on converting existing sources:
  6225 
  6226   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6227   entities, so expressions involving "-" (unary or binary minus) need
  6228   to be spaced properly;
  6229 
  6230   - existing occurrences of "1" may need to be constraint "1::nat" or
  6231   even replaced by Suc 0; similar for old "2";
  6232