NEWS
author haftmann
Wed Jul 13 23:41:13 2011 +0200 (2011-07-13)
changeset 43815 4f6e2965d821
parent 43752 0517a69de5d6
child 43816 05ab37be94ed
permissions -rw-r--r--
adjusted to tightened specification of classes bot and top
     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 * classes bot and top require underlying partial order rather than preorder:
    64 uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
    65 
    66 * Archimedian_Field.thy:
    67     floor now is defined as parameter of a separate type class floor_ceiling.
    68  
    69 * Finite_Set.thy: more coherent development of fold_set locales:
    70 
    71     locale fun_left_comm ~> locale comp_fun_commute
    72     locale fun_left_comm_idem ~> locale comp_fun_idem
    73     
    74 Both use point-free characterisation; interpretation proofs may need adjustment.
    75 INCOMPATIBILITY.
    76 
    77 * Code generation:
    78   - theory Library/Code_Char_ord provides native ordering of characters
    79     in the target language.
    80     
    81 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    82 
    83 * Nitpick:
    84   - Added "need" and "total_consts" options.
    85   - Reintroduced "show_skolems" option by popular demand.
    86   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    87     INCOMPATIBILITY.
    88 
    89 * Sledgehammer:
    90   - sledgehammer available_provers ~> sledgehammer supported_provers.
    91     INCOMPATIBILITY.
    92   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    93     TPTP problems (TFF).
    94   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
    95     and "max_new_mono_instances" options.
    96   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
    97     Proof General menu item. INCOMPATIBILITY.
    98 
    99 * Metis:
   100   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   101   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   102 
   103 * "try":
   104   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   105     options. INCOMPATIBILITY.
   106   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   107     "sledgehammer", "quickcheck", and "nitpick".
   108 
   109 * Quickcheck:
   110   - Added "eval" option to evaluate terms for the found counterexample
   111     (currently only supported by the default (exhaustive) tester)
   112   - Added post-processing of terms to obtain readable counterexamples
   113     (currently only supported by the default (exhaustive) tester)
   114   - New counterexample generator quickcheck[narrowing] enables
   115     narrowing-based testing.
   116     It requires that the Glasgow Haskell compiler is installed and
   117     its location is known to Isabelle with the environment variable
   118     ISABELLE_GHC.
   119 
   120 * Function package: discontinued option "tailrec".
   121 INCOMPATIBILITY. Use partial_function instead.
   122 
   123 * HOL-Probability:
   124   - Caratheodory's extension lemma is now proved for ring_of_sets.
   125   - Infinite products of probability measures are now available.
   126   - Use extended reals instead of positive extended reals.
   127     INCOMPATIBILITY.
   128 
   129 
   130 *** Document preparation ***
   131 
   132 * Discontinued special treatment of hard tabulators, which are better
   133 avoided in the first place.  Implicit tab-width is 1.
   134 
   135 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   136 isar-ref manual.
   137 
   138 * Antiquotation @{value} evaluates the given term and presents its result.
   139 
   140 * Localized \isabellestyle switch can be used within blocks or groups
   141 like this:
   142 
   143   \isabellestyle{it}  %preferred default
   144   {\isabellestylett @{text "typewriter stuff"}}
   145 
   146 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   147 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   148 
   149 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   150 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   151 
   152 
   153 *** ML ***
   154 
   155 * The inner syntax of sort/type/term/prop supports inlined YXML
   156 representations within quoted string tokens.  By encoding logical
   157 entities via Term_XML (in ML or Scala) concrete syntax can be
   158 bypassed, which is particularly useful for producing bits of text
   159 under external program control.
   160 
   161 * Antiquotations for ML and document preparation are managed as theory
   162 data, which requires explicit setup.
   163 
   164 * Isabelle_Process.is_active allows tools to check if the official
   165 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   166 (better known as Proof General).
   167 
   168 * Structure Proof_Context follows standard naming scheme.  Old
   169 ProofContext is still available for some time as legacy alias.
   170 
   171 * Structure Timing provides various operations for timing; supersedes
   172 former start_timing/end_timing etc.
   173 
   174 * Path.print is the official way to show file-system paths to users
   175 (including quotes etc.).
   176 
   177 * Inner syntax: identifiers in parse trees of generic categories
   178 "logic", "aprop", "idt" etc. carry position information (disguised as
   179 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   180 translations that choke on unexpected type constraints.  Positions can
   181 be stripped in ML translations via Syntax.strip_positions /
   182 Syntax.strip_positions_ast, or via the syntax constant
   183 "_strip_positions" within parse trees.  As last resort, positions can
   184 be disabled via the configuration option Syntax.positions, which is
   185 called "syntax_positions" in Isar attribute syntax.
   186 
   187 * Discontinued special status of various ML structures that contribute
   188 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   189 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   190 refer directly to Ast.Constant, Lexicon.is_identifier,
   191 Syntax_Trans.mk_binder_tr etc.
   192 
   193 * Typed print translation: discontinued show_sorts argument, which is
   194 already available via context of "advanced" translation.
   195 
   196 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   197 goal states; body tactic needs to address all subgoals uniformly.
   198 
   199 * Slightly more special eq_list/eq_set, with shortcut involving
   200 pointer equality (assumes that eq relation is reflexive).
   201 
   202 * Classical tactics use proper Proof.context instead of historic types
   203 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   204 operate directly on Proof.context.  Raw type claset retains its use as
   205 snapshot of the classical context, which can be recovered via
   206 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   207 INCOMPATIBILITY, classical tactics and derived proof methods require
   208 proper Proof.context.
   209 
   210 * Scala layer provides JVM method invocation service for static
   211 methods of type (String)String, see Invoke_Scala.method in ML.
   212 For example:
   213 
   214   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   215 
   216 
   217 
   218 New in Isabelle2011 (January 2011)
   219 ----------------------------------
   220 
   221 *** General ***
   222 
   223 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   224 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   225 useful tooltips and hyperlinks produced from its static analysis.  The
   226 bundled component provides an executable Isabelle tool that can be run
   227 like this:
   228 
   229   Isabelle2011/bin/isabelle jedit
   230 
   231 * Significantly improved Isabelle/Isar implementation manual.
   232 
   233 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   234 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   235 while the default heap location within that directory lacks that extra
   236 suffix.  This isolates multiple Isabelle installations from each
   237 other, avoiding problems with old settings in new versions.
   238 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   239 
   240 * Source files are always encoded as UTF-8, instead of old-fashioned
   241 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   242 the following package declarations:
   243 
   244   \usepackage[utf8]{inputenc}
   245   \usepackage{textcomp}
   246 
   247 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   248 a Unicode character is treated as a single symbol, not a sequence of
   249 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   250 contain symbols without further backslash escapes, Unicode can now be
   251 used here as well.  Recall that Symbol.explode in ML provides a
   252 consistent view on symbols, while raw explode (or String.explode)
   253 merely give a byte-oriented representation.
   254 
   255 * Theory loader: source files are primarily located via the master
   256 directory of each theory node (where the .thy file itself resides).
   257 The global load path is still partially available as legacy feature.
   258 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   259 explicit paths, relatively to the theory.
   260 
   261 * Special treatment of ML file names has been discontinued.
   262 Historically, optional extensions .ML or .sml were added on demand --
   263 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   264 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   265 
   266 * Various options that affect pretty printing etc. are now properly
   267 handled within the context via configuration options, instead of
   268 unsynchronized references or print modes.  There are both ML Config.T
   269 entities and Isar declaration attributes to access these.
   270 
   271   ML (Config.T)                 Isar (attribute)
   272 
   273   eta_contract                  eta_contract
   274   show_brackets                 show_brackets
   275   show_sorts                    show_sorts
   276   show_types                    show_types
   277   show_question_marks           show_question_marks
   278   show_consts                   show_consts
   279   show_abbrevs                  show_abbrevs
   280 
   281   Syntax.ast_trace              syntax_ast_trace
   282   Syntax.ast_stat               syntax_ast_stat
   283   Syntax.ambiguity_level        syntax_ambiguity_level
   284 
   285   Goal_Display.goals_limit      goals_limit
   286   Goal_Display.show_main_goal   show_main_goal
   287 
   288   Method.rule_trace             rule_trace
   289 
   290   Thy_Output.display            thy_output_display
   291   Thy_Output.quotes             thy_output_quotes
   292   Thy_Output.indent             thy_output_indent
   293   Thy_Output.source             thy_output_source
   294   Thy_Output.break              thy_output_break
   295 
   296 Note that corresponding "..._default" references in ML may only be
   297 changed globally at the ROOT session setup, but *not* within a theory.
   298 The option "show_abbrevs" supersedes the former print mode
   299 "no_abbrevs" with inverted meaning.
   300 
   301 * More systematic naming of some configuration options.
   302 INCOMPATIBILITY.
   303 
   304   trace_simp  ~>  simp_trace
   305   debug_simp  ~>  simp_debug
   306 
   307 * Support for real valued configuration options, using simplistic
   308 floating-point notation that coincides with the inner syntax for
   309 float_token.
   310 
   311 * Support for real valued preferences (with approximative PGIP type):
   312 front-ends need to accept "pgint" values in float notation.
   313 INCOMPATIBILITY.
   314 
   315 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   316 DejaVu Sans.
   317 
   318 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   319 
   320 
   321 *** Pure ***
   322 
   323 * Command 'type_synonym' (with single argument) replaces somewhat
   324 outdated 'types', which is still available as legacy feature for some
   325 time.
   326 
   327 * Command 'nonterminal' (with 'and' separated list of arguments)
   328 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   329 
   330 * Command 'notepad' replaces former 'example_proof' for
   331 experimentation in Isar without any result.  INCOMPATIBILITY.
   332 
   333 * Locale interpretation commands 'interpret' and 'sublocale' accept
   334 lists of equations to map definitions in a locale to appropriate
   335 entities in the context of the interpretation.  The 'interpretation'
   336 command already provided this functionality.
   337 
   338 * Diagnostic command 'print_dependencies' prints the locale instances
   339 that would be activated if the specified expression was interpreted in
   340 the current context.  Variant "print_dependencies!" assumes a context
   341 without interpretations.
   342 
   343 * Diagnostic command 'print_interps' prints interpretations in proofs
   344 in addition to interpretations in theories.
   345 
   346 * Discontinued obsolete 'global' and 'local' commands to manipulate
   347 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   348 Sign.root_path and Sign.local_path may be applied directly where this
   349 feature is still required for historical reasons.
   350 
   351 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   352 'definition' instead.
   353 
   354 * The "prems" fact, which refers to the accidental collection of
   355 foundational premises in the context, is now explicitly marked as
   356 legacy feature and will be discontinued soon.  Consider using "assms"
   357 of the head statement or reference facts by explicit names.
   358 
   359 * Document antiquotations @{class} and @{type} print classes and type
   360 constructors.
   361 
   362 * Document antiquotation @{file} checks file/directory entries within
   363 the local file system.
   364 
   365 
   366 *** HOL ***
   367 
   368 * Coercive subtyping: functions can be declared as coercions and type
   369 inference will add them as necessary upon input of a term.  Theory
   370 Complex_Main declares real :: nat => real and real :: int => real as
   371 coercions. A coercion function f is declared like this:
   372 
   373   declare [[coercion f]]
   374 
   375 To lift coercions through type constructors (e.g. from nat => real to
   376 nat list => real list), map functions can be declared, e.g.
   377 
   378   declare [[coercion_map map]]
   379 
   380 Currently coercion inference is activated only in theories including
   381 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   382 the configuration option "coercion_enabled", e.g. it can be enabled in
   383 other theories like this:
   384 
   385   declare [[coercion_enabled]]
   386 
   387 * Command 'partial_function' provides basic support for recursive
   388 function definitions over complete partial orders.  Concrete instances
   389 are provided for i) the option type, ii) tail recursion on arbitrary
   390 types, and iii) the heap monad of Imperative_HOL.  See
   391 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   392 for examples.
   393 
   394 * Function package: f.psimps rules are no longer implicitly declared
   395 as [simp].  INCOMPATIBILITY.
   396 
   397 * Datatype package: theorems generated for executable equality (class
   398 "eq") carry proper names and are treated as default code equations.
   399 
   400 * Inductive package: now offers command 'inductive_simps' to
   401 automatically derive instantiated and simplified equations for
   402 inductive predicates, similar to 'inductive_cases'.
   403 
   404 * Command 'enriched_type' allows to register properties of the
   405 functorial structure of types.
   406 
   407 * Improved infrastructure for term evaluation using code generator
   408 techniques, in particular static evaluation conversions.
   409 
   410 * Code generator: Scala (2.8 or higher) has been added to the target
   411 languages.
   412 
   413 * Code generator: globbing constant expressions "*" and "Theory.*"
   414 have been replaced by the more idiomatic "_" and "Theory._".
   415 INCOMPATIBILITY.
   416 
   417 * Code generator: export_code without explicit file declaration prints
   418 to standard output.  INCOMPATIBILITY.
   419 
   420 * Code generator: do not print function definitions for case
   421 combinators any longer.
   422 
   423 * Code generator: simplification with rules determined with
   424 src/Tools/Code/code_simp.ML and method "code_simp".
   425 
   426 * Code generator for records: more idiomatic representation of record
   427 types.  Warning: records are not covered by ancient SML code
   428 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   429 rep_datatype declaration helps to succeed then:
   430 
   431   record 'a foo = ...
   432   ...
   433   rep_datatype foo_ext ...
   434 
   435 * Records: logical foundation type for records does not carry a
   436 '_type' suffix any longer (obsolete due to authentic syntax).
   437 INCOMPATIBILITY.
   438 
   439 * Quickcheck now by default uses exhaustive testing instead of random
   440 testing.  Random testing can be invoked by "quickcheck [random]",
   441 exhaustive testing by "quickcheck [exhaustive]".
   442 
   443 * Quickcheck instantiates polymorphic types with small finite
   444 datatypes by default. This enables a simple execution mechanism to
   445 handle quantifiers and function equality over the finite datatypes.
   446 
   447 * Quickcheck random generator has been renamed from "code" to
   448 "random".  INCOMPATIBILITY.
   449 
   450 * Quickcheck now has a configurable time limit which is set to 30
   451 seconds by default. This can be changed by adding [timeout = n] to the
   452 quickcheck command. The time limit for Auto Quickcheck is still set
   453 independently.
   454 
   455 * Quickcheck in locales considers interpretations of that locale for
   456 counter example search.
   457 
   458 * Sledgehammer:
   459   - Added "smt" and "remote_smt" provers based on the "smt" proof
   460     method. See the Sledgehammer manual for details ("isabelle doc
   461     sledgehammer").
   462   - Renamed commands:
   463     sledgehammer atp_info ~> sledgehammer running_provers
   464     sledgehammer atp_kill ~> sledgehammer kill_provers
   465     sledgehammer available_atps ~> sledgehammer available_provers
   466     INCOMPATIBILITY.
   467   - Renamed options:
   468     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   469     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   470     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   471     (and "ms" and "min" are no longer supported)
   472     INCOMPATIBILITY.
   473 
   474 * Nitpick:
   475   - Renamed options:
   476     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   477     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   478     INCOMPATIBILITY.
   479   - Added support for partial quotient types.
   480   - Added local versions of the "Nitpick.register_xxx" functions.
   481   - Added "whack" option.
   482   - Allow registration of quotient types as codatatypes.
   483   - Improved "merge_type_vars" option to merge more types.
   484   - Removed unsound "fast_descrs" option.
   485   - Added custom symmetry breaking for datatypes, making it possible to reach
   486     higher cardinalities.
   487   - Prevent the expansion of too large definitions.
   488 
   489 * Proof methods "metis" and "meson" now have configuration options
   490 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   491 to diagnose these tools. E.g.
   492 
   493     using [[metis_trace = true]]
   494 
   495 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   496 manually as command 'solve_direct'.
   497 
   498 * The default SMT solver Z3 must be enabled explicitly (due to
   499 licensing issues) by setting the environment variable
   500 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   501 commercial applications, the SMT solver CVC3 is provided as fall-back;
   502 changing the SMT solver is done via the configuration option
   503 "smt_solver".
   504 
   505 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   506 i.e. "remote_cvc3" and "remote_z3".
   507 
   508 * Added basic SMT support for datatypes, records, and typedefs using
   509 the oracle mode (no proofs).  Direct support of pairs has been dropped
   510 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   511 support for a similar behavior).  Minor INCOMPATIBILITY.
   512 
   513 * Changed SMT configuration options:
   514   - Renamed:
   515     z3_proofs ~> smt_oracle (with inverted meaning)
   516     z3_trace_assms ~> smt_trace_used_facts
   517     INCOMPATIBILITY.
   518   - Added:
   519     smt_verbose
   520     smt_random_seed
   521     smt_datatypes
   522     smt_infer_triggers
   523     smt_monomorph_limit
   524     cvc3_options
   525     remote_cvc3_options
   526     remote_z3_options
   527     yices_options
   528 
   529 * Boogie output files (.b2i files) need to be declared in the theory
   530 header.
   531 
   532 * Simplification procedure "list_to_set_comprehension" rewrites list
   533 comprehensions applied to List.set to set comprehensions.  Occasional
   534 INCOMPATIBILITY, may be deactivated like this:
   535 
   536   declare [[simproc del: list_to_set_comprehension]]
   537 
   538 * Removed old version of primrec package.  INCOMPATIBILITY.
   539 
   540 * Removed simplifier congruence rule of "prod_case", as has for long
   541 been the case with "split".  INCOMPATIBILITY.
   542 
   543 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   544 
   545 * Removed [split_format ... and ... and ...] version of
   546 [split_format].  Potential INCOMPATIBILITY.
   547 
   548 * Predicate "sorted" now defined inductively, with nice induction
   549 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   550 
   551 * Constant "contents" renamed to "the_elem", to free the generic name
   552 contents for other uses.  INCOMPATIBILITY.
   553 
   554 * Renamed class eq and constant eq (for code generation) to class
   555 equal and constant equal, plus renaming of related facts and various
   556 tuning.  INCOMPATIBILITY.
   557 
   558 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   559 
   560 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   561 INCOMPATIBILITY.
   562 
   563 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   564 avoid confusion with finite sets.  INCOMPATIBILITY.
   565 
   566 * Abandoned locales equiv, congruent and congruent2 for equivalence
   567 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   568 for congruent(2)).
   569 
   570 * Some previously unqualified names have been qualified:
   571 
   572   types
   573     bool ~> HOL.bool
   574     nat ~> Nat.nat
   575 
   576   constants
   577     Trueprop ~> HOL.Trueprop
   578     True ~> HOL.True
   579     False ~> HOL.False
   580     op & ~> HOL.conj
   581     op | ~> HOL.disj
   582     op --> ~> HOL.implies
   583     op = ~> HOL.eq
   584     Not ~> HOL.Not
   585     The ~> HOL.The
   586     All ~> HOL.All
   587     Ex ~> HOL.Ex
   588     Ex1 ~> HOL.Ex1
   589     Let ~> HOL.Let
   590     If ~> HOL.If
   591     Ball ~> Set.Ball
   592     Bex ~> Set.Bex
   593     Suc ~> Nat.Suc
   594     Pair ~> Product_Type.Pair
   595     fst ~> Product_Type.fst
   596     snd ~> Product_Type.snd
   597     curry ~> Product_Type.curry
   598     op : ~> Set.member
   599     Collect ~> Set.Collect
   600 
   601 INCOMPATIBILITY.
   602 
   603 * More canonical naming convention for some fundamental definitions:
   604 
   605     bot_bool_eq ~> bot_bool_def
   606     top_bool_eq ~> top_bool_def
   607     inf_bool_eq ~> inf_bool_def
   608     sup_bool_eq ~> sup_bool_def
   609     bot_fun_eq  ~> bot_fun_def
   610     top_fun_eq  ~> top_fun_def
   611     inf_fun_eq  ~> inf_fun_def
   612     sup_fun_eq  ~> sup_fun_def
   613 
   614 INCOMPATIBILITY.
   615 
   616 * More stylized fact names:
   617 
   618   expand_fun_eq ~> fun_eq_iff
   619   expand_set_eq ~> set_eq_iff
   620   set_ext       ~> set_eqI
   621   nat_number    ~> eval_nat_numeral
   622 
   623 INCOMPATIBILITY.
   624 
   625 * Refactoring of code-generation specific operations in theory List:
   626 
   627   constants
   628     null ~> List.null
   629 
   630   facts
   631     mem_iff ~> member_def
   632     null_empty ~> null_def
   633 
   634 INCOMPATIBILITY.  Note that these were not supposed to be used
   635 regularly unless for striking reasons; their main purpose was code
   636 generation.
   637 
   638 Various operations from the Haskell prelude are used for generating
   639 Haskell code.
   640 
   641 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   642 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   643 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   644 
   645 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   646 "*" and "+" respectively.  INCOMPATIBILITY.
   647 
   648 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   649 "Sum_Type.Plus" instead.
   650 
   651 * Constant "split" has been merged with constant "prod_case"; names of
   652 ML functions, facts etc. involving split have been retained so far,
   653 though.  INCOMPATIBILITY.
   654 
   655 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   656 instead.  INCOMPATIBILITY.
   657 
   658 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   659 INCOMPATIBILITY.
   660 
   661 * Former theory Library/Enum is now part of the HOL-Main image.
   662 INCOMPATIBILITY: all constants of the Enum theory now have to be
   663 referred to by its qualified name.
   664 
   665   enum    ~>  Enum.enum
   666   nlists  ~>  Enum.nlists
   667   product ~>  Enum.product
   668 
   669 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   670 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   671 INCOMPATIBILITY.
   672 
   673 * Theory Library/SetsAndFunctions has been split into
   674 Library/Function_Algebras and Library/Set_Algebras; canonical names
   675 for instance definitions for functions; various improvements.
   676 INCOMPATIBILITY.
   677 
   678 * Theory Library/Multiset provides stable quicksort implementation of
   679 sort_key.
   680 
   681 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   682 INCOMPATIBILITY.
   683 
   684 * Session Multivariate_Analysis: introduced a type class for euclidean
   685 space.  Most theorems are now stated in terms of euclidean spaces
   686 instead of finite cartesian products.
   687 
   688   types
   689     real ^ 'n ~>  'a::real_vector
   690               ~>  'a::euclidean_space
   691               ~>  'a::ordered_euclidean_space
   692         (depends on your needs)
   693 
   694   constants
   695      _ $ _        ~> _ $$ _
   696      \<chi> x. _  ~> \<chi>\<chi> x. _
   697      CARD('n)     ~> DIM('a)
   698 
   699 Also note that the indices are now natural numbers and not from some
   700 finite type. Finite cartesian products of euclidean spaces, products
   701 of euclidean spaces the real and complex numbers are instantiated to
   702 be euclidean_spaces.  INCOMPATIBILITY.
   703 
   704 * Session Probability: introduced pextreal as positive extended real
   705 numbers.  Use pextreal as value for measures.  Introduce the
   706 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   707 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   708 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   709 
   710 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   711 INCOMPATIBILITY.
   712 
   713 * Session SPARK (with image HOL-SPARK) provides commands to load and
   714 prove verification conditions generated by the SPARK Ada program
   715 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   716 
   717 
   718 *** HOL-Algebra ***
   719 
   720 * Theorems for additive ring operations (locale abelian_monoid and
   721 descendants) are generated by interpretation from their multiplicative
   722 counterparts.  Names (in particular theorem names) have the mandatory
   723 qualifier 'add'.  Previous theorem names are redeclared for
   724 compatibility.
   725 
   726 * Structure "int_ring" is now an abbreviation (previously a
   727 definition).  This fits more natural with advanced interpretations.
   728 
   729 
   730 *** HOLCF ***
   731 
   732 * The domain package now runs in definitional mode by default: The
   733 former command 'new_domain' is now called 'domain'.  To use the domain
   734 package in its original axiomatic mode, use 'domain (unsafe)'.
   735 INCOMPATIBILITY.
   736 
   737 * The new class "domain" is now the default sort.  Class "predomain"
   738 is an unpointed version of "domain". Theories can be updated by
   739 replacing sort annotations as shown below.  INCOMPATIBILITY.
   740 
   741   'a::type ~> 'a::countable
   742   'a::cpo  ~> 'a::predomain
   743   'a::pcpo ~> 'a::domain
   744 
   745 * The old type class "rep" has been superseded by class "domain".
   746 Accordingly, users of the definitional package must remove any
   747 "default_sort rep" declarations.  INCOMPATIBILITY.
   748 
   749 * The domain package (definitional mode) now supports unpointed
   750 predomain argument types, as long as they are marked 'lazy'. (Strict
   751 arguments must be in class "domain".) For example, the following
   752 domain definition now works:
   753 
   754   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   755 
   756 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   757 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   758 'a option, and 'a list.  Additionally, it configures fixrec and the
   759 domain package to work with these types.  For example:
   760 
   761   fixrec isInl :: "('a + 'b) u -> tr"
   762     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   763 
   764   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   765 
   766 * The "(permissive)" option of fixrec has been replaced with a
   767 per-equation "(unchecked)" option. See
   768 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   769 
   770 * The "bifinite" class no longer fixes a constant "approx"; the class
   771 now just asserts that such a function exists.  INCOMPATIBILITY.
   772 
   773 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   774 defines an embedding of type 'a defl into udom by default; instances
   775 of "bifinite" and "domain" classes are available in
   776 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   777 
   778 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   779 
   780 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   781 
   782 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   783 
   784 * The function "cprod_map" has been renamed to "prod_map".
   785 INCOMPATIBILITY.
   786 
   787 * The monadic bind operator on each powerdomain has new binder syntax
   788 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   789 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   790 
   791 * The infix syntax for binary union on each powerdomain has changed
   792 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   793 syntax.  INCOMPATIBILITY.
   794 
   795 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   796 still supported as an input translation.
   797 
   798 * Renamed some theorems (the original names are also still available).
   799 
   800   expand_fun_below   ~> fun_below_iff
   801   below_fun_ext      ~> fun_belowI
   802   expand_cfun_eq     ~> cfun_eq_iff
   803   ext_cfun           ~> cfun_eqI
   804   expand_cfun_below  ~> cfun_below_iff
   805   below_cfun_ext     ~> cfun_belowI
   806   cont2cont_Rep_CFun ~> cont2cont_APP
   807 
   808 * The Abs and Rep functions for various types have changed names.
   809 Related theorem names have also changed to match. INCOMPATIBILITY.
   810 
   811   Rep_CFun  ~> Rep_cfun
   812   Abs_CFun  ~> Abs_cfun
   813   Rep_Sprod ~> Rep_sprod
   814   Abs_Sprod ~> Abs_sprod
   815   Rep_Ssum  ~> Rep_ssum
   816   Abs_Ssum  ~> Abs_ssum
   817 
   818 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   819 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   820 
   821 * Various changes to bisimulation/coinduction with domain package:
   822 
   823   - Definitions of "bisim" constants no longer mention definedness.
   824   - With mutual recursion, "bisim" predicate is now curried.
   825   - With mutual recursion, each type gets a separate coind theorem.
   826   - Variable names in bisim_def and coinduct rules have changed.
   827 
   828 INCOMPATIBILITY.
   829 
   830 * Case combinators generated by the domain package for type "foo" are
   831 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   832 
   833 * Several theorems have been renamed to more accurately reflect the
   834 names of constants and types involved.  INCOMPATIBILITY.
   835 
   836   thelub_const    ~> lub_const
   837   lub_const       ~> is_lub_const
   838   thelubI         ~> lub_eqI
   839   is_lub_lub      ~> is_lubD2
   840   lubI            ~> is_lub_lub
   841   unique_lub      ~> is_lub_unique
   842   is_ub_lub       ~> is_lub_rangeD1
   843   lub_bin_chain   ~> is_lub_bin_chain
   844   lub_fun         ~> is_lub_fun
   845   thelub_fun      ~> lub_fun
   846   thelub_cfun     ~> lub_cfun
   847   thelub_Pair     ~> lub_Pair
   848   lub_cprod       ~> is_lub_prod
   849   thelub_cprod    ~> lub_prod
   850   minimal_cprod   ~> minimal_prod
   851   inst_cprod_pcpo ~> inst_prod_pcpo
   852   UU_I            ~> bottomI
   853   compact_UU      ~> compact_bottom
   854   deflation_UU    ~> deflation_bottom
   855   finite_deflation_UU ~> finite_deflation_bottom
   856 
   857 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   858 
   859   sq_ord_less_eq_trans ~> below_eq_trans
   860   sq_ord_eq_less_trans ~> eq_below_trans
   861   refl_less            ~> below_refl
   862   trans_less           ~> below_trans
   863   antisym_less         ~> below_antisym
   864   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   865   box_less             ~> box_below
   866   rev_trans_less       ~> rev_below_trans
   867   not_less2not_eq      ~> not_below2not_eq
   868   less_UU_iff          ~> below_UU_iff
   869   flat_less_iff        ~> flat_below_iff
   870   adm_less             ~> adm_below
   871   adm_not_less         ~> adm_not_below
   872   adm_compact_not_less ~> adm_compact_not_below
   873   less_fun_def         ~> below_fun_def
   874   expand_fun_less      ~> fun_below_iff
   875   less_fun_ext         ~> fun_belowI
   876   less_discr_def       ~> below_discr_def
   877   discr_less_eq        ~> discr_below_eq
   878   less_unit_def        ~> below_unit_def
   879   less_cprod_def       ~> below_prod_def
   880   prod_lessI           ~> prod_belowI
   881   Pair_less_iff        ~> Pair_below_iff
   882   fst_less_iff         ~> fst_below_iff
   883   snd_less_iff         ~> snd_below_iff
   884   expand_cfun_less     ~> cfun_below_iff
   885   less_cfun_ext        ~> cfun_belowI
   886   injection_less       ~> injection_below
   887   less_up_def          ~> below_up_def
   888   not_Iup_less         ~> not_Iup_below
   889   Iup_less             ~> Iup_below
   890   up_less              ~> up_below
   891   Def_inject_less_eq   ~> Def_below_Def
   892   Def_less_is_eq       ~> Def_below_iff
   893   spair_less_iff       ~> spair_below_iff
   894   less_sprod           ~> below_sprod
   895   spair_less           ~> spair_below
   896   sfst_less_iff        ~> sfst_below_iff
   897   ssnd_less_iff        ~> ssnd_below_iff
   898   fix_least_less       ~> fix_least_below
   899   dist_less_one        ~> dist_below_one
   900   less_ONE             ~> below_ONE
   901   ONE_less_iff         ~> ONE_below_iff
   902   less_sinlD           ~> below_sinlD
   903   less_sinrD           ~> below_sinrD
   904 
   905 
   906 *** FOL and ZF ***
   907 
   908 * All constant names are now qualified internally and use proper
   909 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   910 
   911 
   912 *** ML ***
   913 
   914 * Antiquotation @{assert} inlines a function bool -> unit that raises
   915 Fail if the argument is false.  Due to inlining the source position of
   916 failed assertions is included in the error output.
   917 
   918 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   919 text is in practice always evaluated with a stable theory checkpoint.
   920 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   921 
   922 * Antiquotation @{theory A} refers to theory A from the ancestry of
   923 the current context, not any accidental theory loader state as before.
   924 Potential INCOMPATIBILITY, subtle change in semantics.
   925 
   926 * Syntax.pretty_priority (default 0) configures the required priority
   927 of pretty-printed output and thus affects insertion of parentheses.
   928 
   929 * Syntax.default_root (default "any") configures the inner syntax
   930 category (nonterminal symbol) for parsing of terms.
   931 
   932 * Former exception Library.UnequalLengths now coincides with
   933 ListPair.UnequalLengths.
   934 
   935 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   936 main functionality is provided by structure Simplifier.
   937 
   938 * Renamed raw "explode" function to "raw_explode" to emphasize its
   939 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   940 almost all situations.
   941 
   942 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   943 See implementation manual for further details on exceptions in
   944 Isabelle/ML.
   945 
   946 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   947 meaning.
   948 
   949 * Renamed structure PureThy to Pure_Thy and moved most of its
   950 operations to structure Global_Theory, to emphasize that this is
   951 rarely-used global-only stuff.
   952 
   953 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   954 instead (or tracing for high-volume output).
   955 
   956 * Configuration option show_question_marks only affects regular pretty
   957 printing of types and terms, not raw Term.string_of_vname.
   958 
   959 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   960 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   961 @{thms} for most purposes.
   962 
   963 * ML structure Unsynchronized is never opened, not even in Isar
   964 interaction mode as before.  Old Unsynchronized.set etc. have been
   965 discontinued -- use plain := instead.  This should be *rare* anyway,
   966 since modern tools always work via official context data, notably
   967 configuration options.
   968 
   969 * Parallel and asynchronous execution requires special care concerning
   970 interrupts.  Structure Exn provides some convenience functions that
   971 avoid working directly with raw Interrupt.  User code must not absorb
   972 interrupts -- intermediate handling (for cleanup etc.) needs to be
   973 followed by re-raising of the original exception.  Another common
   974 source of mistakes are "handle _" patterns, which make the meaning of
   975 the program subject to physical effects of the environment.
   976 
   977 
   978 
   979 New in Isabelle2009-2 (June 2010)
   980 ---------------------------------
   981 
   982 *** General ***
   983 
   984 * Authentic syntax for *all* logical entities (type classes, type
   985 constructors, term constants): provides simple and robust
   986 correspondence between formal entities and concrete syntax.  Within
   987 the parse tree / AST representations, "constants" are decorated by
   988 their category (class, type, const) and spelled out explicitly with
   989 their full internal name.
   990 
   991 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   992 and translations (translation rules and translation functions in ML).
   993 Some hints on upgrading:
   994 
   995   - Many existing uses of 'syntax' and 'translations' can be replaced
   996     by more modern 'type_notation', 'notation' and 'abbreviation',
   997     which are independent of this issue.
   998 
   999   - 'translations' require markup within the AST; the term syntax
  1000     provides the following special forms:
  1001 
  1002       CONST c   -- produces syntax version of constant c from context
  1003       XCONST c  -- literally c, checked as constant from context
  1004       c         -- literally c, if declared by 'syntax'
  1005 
  1006     Plain identifiers are treated as AST variables -- occasionally the
  1007     system indicates accidental variables via the error "rhs contains
  1008     extra variables".
  1009 
  1010     Type classes and type constructors are marked according to their
  1011     concrete syntax.  Some old translations rules need to be written
  1012     for the "type" category, using type constructor application
  1013     instead of pseudo-term application of the default category
  1014     "logic".
  1015 
  1016   - 'parse_translation' etc. in ML may use the following
  1017     antiquotations:
  1018 
  1019       @{class_syntax c}   -- type class c within parse tree / AST
  1020       @{term_syntax c}    -- type constructor c within parse tree / AST
  1021       @{const_syntax c}   -- ML version of "CONST c" above
  1022       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1023 
  1024   - Literal types within 'typed_print_translations', i.e. those *not*
  1025     represented as pseudo-terms are represented verbatim.  Use @{class
  1026     c} or @{type_name c} here instead of the above syntax
  1027     antiquotations.
  1028 
  1029 Note that old non-authentic syntax was based on unqualified base
  1030 names, so all of the above "constant" names would coincide.  Recall
  1031 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1032 diagnose syntax problems.
  1033 
  1034 * Type constructors admit general mixfix syntax, not just infix.
  1035 
  1036 * Concrete syntax may be attached to local entities without a proof
  1037 body, too.  This works via regular mixfix annotations for 'fix',
  1038 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1039 similar to the 'notation' command in theory specifications.
  1040 
  1041 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1042 need to specify constant name and syntax separately.  Internal ML
  1043 datatype constructors have been renamed from InfixName to Infix etc.
  1044 Minor INCOMPATIBILITY.
  1045 
  1046 * Schematic theorem statements need to be explicitly markup as such,
  1047 via commands 'schematic_lemma', 'schematic_theorem',
  1048 'schematic_corollary'.  Thus the relevance of the proof is made
  1049 syntactically clear, which impacts performance in a parallel or
  1050 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1051 
  1052 * Use of cumulative prems via "!" in some proof methods has been
  1053 discontinued (old legacy feature).
  1054 
  1055 * References 'trace_simp' and 'debug_simp' have been replaced by
  1056 configuration options stored in the context. Enabling tracing (the
  1057 case of debugging is similar) in proofs works via
  1058 
  1059   using [[trace_simp = true]]
  1060 
  1061 Tracing is then active for all invocations of the simplifier in
  1062 subsequent goal refinement steps. Tracing may also still be enabled or
  1063 disabled via the ProofGeneral settings menu.
  1064 
  1065 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1066 'hide_fact' replace the former 'hide' KIND command.  Minor
  1067 INCOMPATIBILITY.
  1068 
  1069 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1070 more efficient than combinations with -q1 or -q2.
  1071 
  1072 
  1073 *** Pure ***
  1074 
  1075 * Proofterms record type-class reasoning explicitly, using the
  1076 "unconstrain" operation internally.  This eliminates all sort
  1077 constraints from a theorem and proof, introducing explicit
  1078 OFCLASS-premises.  On the proof term level, this operation is
  1079 automatically applied at theorem boundaries, such that closed proofs
  1080 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1081 inspect proof terms.
  1082 
  1083 * Local theory specifications may depend on extra type variables that
  1084 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1085 are added internally.  For example:
  1086 
  1087   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1088 
  1089 * Predicates of locales introduced by classes carry a mandatory
  1090 "class" prefix.  INCOMPATIBILITY.
  1091 
  1092 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1093 
  1094 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1095 'class' instead.
  1096 
  1097 * Command 'code_reflect' allows to incorporate generated ML code into
  1098 runtime environment; replaces immature code_datatype antiquotation.
  1099 INCOMPATIBILITY.
  1100 
  1101 * Code generator: simple concept for abstract datatypes obeying
  1102 invariants.
  1103 
  1104 * Code generator: details of internal data cache have no impact on the
  1105 user space functionality any longer.
  1106 
  1107 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1108 subgoals.  This is more appropriate for interpretations with 'where'.
  1109 INCOMPATIBILITY.
  1110 
  1111 * Command 'example_proof' opens an empty proof body.  This allows to
  1112 experiment with Isar, without producing any persistent result.
  1113 
  1114 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1115 within a local theory context, with explicit checking of the
  1116 constructors involved (in contrast to the raw 'syntax' versions).
  1117 
  1118 * Commands 'types' and 'typedecl' now work within a local theory
  1119 context -- without introducing dependencies on parameters or
  1120 assumptions, which is not possible in Isabelle/Pure.
  1121 
  1122 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1123 within a local theory context.  Minor INCOMPATIBILITY.
  1124 
  1125 
  1126 *** HOL ***
  1127 
  1128 * Command 'typedef' now works within a local theory context -- without
  1129 introducing dependencies on parameters or assumptions, which is not
  1130 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1131 contain multiple interpretations of local typedefs (with different
  1132 non-emptiness proofs), even in a global theory context.
  1133 
  1134 * New package for quotient types.  Commands 'quotient_type' and
  1135 'quotient_definition' may be used for defining types and constants by
  1136 quotient constructions.  An example is the type of integers created by
  1137 quotienting pairs of natural numbers:
  1138 
  1139   fun
  1140     intrel :: "(nat * nat) => (nat * nat) => bool"
  1141   where
  1142     "intrel (x, y) (u, v) = (x + v = u + y)"
  1143 
  1144   quotient_type int = "nat * nat" / intrel
  1145     by (auto simp add: equivp_def expand_fun_eq)
  1146 
  1147   quotient_definition
  1148     "0::int" is "(0::nat, 0::nat)"
  1149 
  1150 The method "lifting" can be used to lift of theorems from the
  1151 underlying "raw" type to the quotient type.  The example
  1152 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1153 construction and provides a reasoning infrastructure for finite sets.
  1154 
  1155 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1156 clash with new theory Quotient in Main HOL.
  1157 
  1158 * Moved the SMT binding into the main HOL session, eliminating
  1159 separate HOL-SMT session.
  1160 
  1161 * List membership infix mem operation is only an input abbreviation.
  1162 INCOMPATIBILITY.
  1163 
  1164 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1165 for future developements; former Library/Word.thy is still present in
  1166 the AFP entry RSAPPS.
  1167 
  1168 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1169 longer shadowed.  INCOMPATIBILITY.
  1170 
  1171 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1172 INCOMPATIBILITY.
  1173 
  1174 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1175 INCOMPATIBILITY.
  1176 
  1177 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1178 instead.  INCOMPATIBILITY.
  1179 
  1180 * Dropped several real-specific versions of lemmas about floor and
  1181 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1182 instead.  INCOMPATIBILITY.
  1183 
  1184   floor_number_of_eq         ~> floor_number_of
  1185   le_floor_eq_number_of      ~> number_of_le_floor
  1186   le_floor_eq_zero           ~> zero_le_floor
  1187   le_floor_eq_one            ~> one_le_floor
  1188   floor_less_eq_number_of    ~> floor_less_number_of
  1189   floor_less_eq_zero         ~> floor_less_zero
  1190   floor_less_eq_one          ~> floor_less_one
  1191   less_floor_eq_number_of    ~> number_of_less_floor
  1192   less_floor_eq_zero         ~> zero_less_floor
  1193   less_floor_eq_one          ~> one_less_floor
  1194   floor_le_eq_number_of      ~> floor_le_number_of
  1195   floor_le_eq_zero           ~> floor_le_zero
  1196   floor_le_eq_one            ~> floor_le_one
  1197   floor_subtract_number_of   ~> floor_diff_number_of
  1198   floor_subtract_one         ~> floor_diff_one
  1199   ceiling_number_of_eq       ~> ceiling_number_of
  1200   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1201   ceiling_le_zero_eq         ~> ceiling_le_zero
  1202   ceiling_le_eq_one          ~> ceiling_le_one
  1203   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1204   less_ceiling_eq_zero       ~> zero_less_ceiling
  1205   less_ceiling_eq_one        ~> one_less_ceiling
  1206   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1207   ceiling_less_eq_zero       ~> ceiling_less_zero
  1208   ceiling_less_eq_one        ~> ceiling_less_one
  1209   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1210   le_ceiling_eq_zero         ~> zero_le_ceiling
  1211   le_ceiling_eq_one          ~> one_le_ceiling
  1212   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1213   ceiling_subtract_one       ~> ceiling_diff_one
  1214 
  1215 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1216 application of the various fold combinators on finite sets.
  1217 
  1218 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1219 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1220 implementation.  INCOMPATIBILTY.
  1221 
  1222 * Theory Library/Coinductive_List has been removed -- superseded by
  1223 AFP/thys/Coinductive.
  1224 
  1225 * Theory PReal, including the type "preal" and related operations, has
  1226 been removed.  INCOMPATIBILITY.
  1227 
  1228 * Real: new development using Cauchy Sequences.
  1229 
  1230 * Split off theory "Big_Operators" containing setsum, setprod,
  1231 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1232 
  1233 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1234 "Int" etc.  INCOMPATIBILITY.
  1235 
  1236 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1237 
  1238 * New set of rules "ac_simps" provides combined assoc / commute
  1239 rewrites for all interpretations of the appropriate generic locales.
  1240 
  1241 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1242 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1243 appropriate and more consistent names suitable for name prefixes
  1244 within the HOL theories.  INCOMPATIBILITY.
  1245 
  1246 * Some generic constants have been put to appropriate theories:
  1247   - less_eq, less: Orderings
  1248   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1249   - inverse, divide: Rings
  1250 INCOMPATIBILITY.
  1251 
  1252 * More consistent naming of type classes involving orderings (and
  1253 lattices):
  1254 
  1255     lower_semilattice                   ~> semilattice_inf
  1256     upper_semilattice                   ~> semilattice_sup
  1257 
  1258     dense_linear_order                  ~> dense_linorder
  1259 
  1260     pordered_ab_group_add               ~> ordered_ab_group_add
  1261     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1262     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1263     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1264     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1265     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1266     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1267     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1268     pordered_comm_ring                  ~> ordered_comm_ring
  1269     pordered_comm_semiring              ~> ordered_comm_semiring
  1270     pordered_ring                       ~> ordered_ring
  1271     pordered_ring_abs                   ~> ordered_ring_abs
  1272     pordered_semiring                   ~> ordered_semiring
  1273 
  1274     ordered_ab_group_add                ~> linordered_ab_group_add
  1275     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1276     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1277     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1278     ordered_field                       ~> linordered_field
  1279     ordered_field_no_lb                 ~> linordered_field_no_lb
  1280     ordered_field_no_ub                 ~> linordered_field_no_ub
  1281     ordered_field_dense_linear_order    ~> dense_linordered_field
  1282     ordered_idom                        ~> linordered_idom
  1283     ordered_ring                        ~> linordered_ring
  1284     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1285     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1286     ordered_ring_strict                 ~> linordered_ring_strict
  1287     ordered_semidom                     ~> linordered_semidom
  1288     ordered_semiring                    ~> linordered_semiring
  1289     ordered_semiring_1                  ~> linordered_semiring_1
  1290     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1291     ordered_semiring_strict             ~> linordered_semiring_strict
  1292 
  1293   The following slightly odd type classes have been moved to a
  1294   separate theory Library/Lattice_Algebras:
  1295 
  1296     lordered_ab_group_add               ~> lattice_ab_group_add
  1297     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1298     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1299     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1300     lordered_ring                       ~> lattice_ring
  1301 
  1302 INCOMPATIBILITY.
  1303 
  1304 * Refined field classes:
  1305   - classes division_ring_inverse_zero, field_inverse_zero,
  1306     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1307     subsumes former division_by_zero class;
  1308   - numerous lemmas have been ported from field to division_ring.
  1309 INCOMPATIBILITY.
  1310 
  1311 * Refined algebra theorem collections:
  1312   - dropped theorem group group_simps, use algebra_simps instead;
  1313   - dropped theorem group ring_simps, use field_simps instead;
  1314   - proper theorem collection field_simps subsumes former theorem
  1315     groups field_eq_simps and field_simps;
  1316   - dropped lemma eq_minus_self_iff which is a duplicate for
  1317     equal_neg_zero.
  1318 INCOMPATIBILITY.
  1319 
  1320 * Theory Finite_Set and List: some lemmas have been generalized from
  1321 sets to lattices:
  1322 
  1323   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1324   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1325   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1326   union_Union_fold_union        ~> sup_Sup_fold_sup
  1327   Inter_fold_inter              ~> Inf_fold_inf
  1328   Union_fold_union              ~> Sup_fold_sup
  1329   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1330   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1331   INTER_fold_inter              ~> INFI_fold_inf
  1332   UNION_fold_union              ~> SUPR_fold_sup
  1333 
  1334 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1335 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1336 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1337 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1338 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1339 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1340 
  1341 * Reorganized theory Multiset: swapped notation of pointwise and
  1342 multiset order:
  1343 
  1344   - pointwise ordering is instance of class order with standard syntax
  1345     <= and <;
  1346   - multiset ordering has syntax <=# and <#; partial order properties
  1347     are provided by means of interpretation with prefix
  1348     multiset_order;
  1349   - less duplication, less historical organization of sections,
  1350     conversion from associations lists to multisets, rudimentary code
  1351     generation;
  1352   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1353     if needed.
  1354 
  1355 Renamed:
  1356 
  1357   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1358   multi_count_ext  ~>  multiset_ext
  1359   diff_union_inverse2  ~>  diff_union_cancelR
  1360 
  1361 INCOMPATIBILITY.
  1362 
  1363 * Theory Permutation: replaced local "remove" by List.remove1.
  1364 
  1365 * Code generation: ML and OCaml code is decorated with signatures.
  1366 
  1367 * Theory List: added transpose.
  1368 
  1369 * Library/Nat_Bijection.thy is a collection of bijective functions
  1370 between nat and other types, which supersedes the older libraries
  1371 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1372 
  1373   Constants:
  1374   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1375   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1376   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1377   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1378   Countable.pair_encode           ~> prod_encode
  1379   NatIso.prod2nat                 ~> prod_encode
  1380   NatIso.nat2prod                 ~> prod_decode
  1381   NatIso.sum2nat                  ~> sum_encode
  1382   NatIso.nat2sum                  ~> sum_decode
  1383   NatIso.list2nat                 ~> list_encode
  1384   NatIso.nat2list                 ~> list_decode
  1385   NatIso.set2nat                  ~> set_encode
  1386   NatIso.nat2set                  ~> set_decode
  1387 
  1388   Lemmas:
  1389   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1390   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1391   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1392   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1393   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1394   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1395   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1396   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1397   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1398   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1399   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1400   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1401   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1402 
  1403 * Sledgehammer:
  1404   - Renamed ATP commands:
  1405     atp_info     ~> sledgehammer running_atps
  1406     atp_kill     ~> sledgehammer kill_atps
  1407     atp_messages ~> sledgehammer messages
  1408     atp_minimize ~> sledgehammer minimize
  1409     print_atps   ~> sledgehammer available_atps
  1410     INCOMPATIBILITY.
  1411   - Added user's manual ("isabelle doc sledgehammer").
  1412   - Added option syntax and "sledgehammer_params" to customize
  1413     Sledgehammer's behavior.  See the manual for details.
  1414   - Modified the Isar proof reconstruction code so that it produces
  1415     direct proofs rather than proofs by contradiction.  (This feature
  1416     is still experimental.)
  1417   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1418     full-typed mode.
  1419   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1420 
  1421 * Nitpick:
  1422   - Added and implemented "binary_ints" and "bits" options.
  1423   - Added "std" option and implemented support for nonstandard models.
  1424   - Added and implemented "finitize" option to improve the precision
  1425     of infinite datatypes based on a monotonicity analysis.
  1426   - Added support for quotient types.
  1427   - Added support for "specification" and "ax_specification"
  1428     constructs.
  1429   - Added support for local definitions (for "function" and
  1430     "termination" proofs).
  1431   - Added support for term postprocessors.
  1432   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1433   - Improved efficiency of "destroy_constrs" optimization.
  1434   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1435     record getters.
  1436   - Fixed soundness bug related to higher-order constructors.
  1437   - Fixed soundness bug when "full_descrs" is enabled.
  1438   - Improved precision of set constructs.
  1439   - Added "atoms" option.
  1440   - Added cache to speed up repeated Kodkod invocations on the same
  1441     problems.
  1442   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1443     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1444     "SAT4J_Light".  INCOMPATIBILITY.
  1445   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1446     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1447   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1448 
  1449 * Method "induct" now takes instantiations of the form t, where t is not
  1450   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1451   If this is not intended, t has to be enclosed in parentheses.
  1452   By default, the equalities generated by definitional instantiations
  1453   are pre-simplified, which may cause parameters of inductive cases
  1454   to disappear, or may even delete some of the inductive cases.
  1455   Use "induct (no_simp)" instead of "induct" to restore the old
  1456   behaviour. The (no_simp) option is also understood by the "cases"
  1457   and "nominal_induct" methods, which now perform pre-simplification, too.
  1458   INCOMPATIBILITY.
  1459 
  1460 
  1461 *** HOLCF ***
  1462 
  1463 * Variable names in lemmas generated by the domain package have
  1464 changed; the naming scheme is now consistent with the HOL datatype
  1465 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1466 
  1467 * The domain package no longer defines the function "foo_copy" for
  1468 recursive domain "foo".  The reach lemma is now stated directly in
  1469 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1470 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1471 
  1472 * Most definedness lemmas generated by the domain package (previously
  1473 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1474 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1475 Proofs that used definedness lemmas as intro rules may break,
  1476 potential INCOMPATIBILITY.
  1477 
  1478 * Induction and casedist rules generated by the domain package now
  1479 declare proper case_names (one called "bottom", and one named for each
  1480 constructor).  INCOMPATIBILITY.
  1481 
  1482 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1483 rules are generated for each domain, INCOMPATIBILITY.
  1484 
  1485   foo_bar.reach       ~> foo.reach  bar.reach
  1486   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1487 
  1488 * Some lemmas generated by the domain package have been renamed for
  1489 consistency with the datatype package, INCOMPATIBILITY.
  1490 
  1491   foo.ind        ~> foo.induct
  1492   foo.finite_ind ~> foo.finite_induct
  1493   foo.coind      ~> foo.coinduct
  1494   foo.casedist   ~> foo.exhaust
  1495   foo.exhaust    ~> foo.nchotomy
  1496 
  1497 * For consistency with other definition packages, the fixrec package
  1498 now generates qualified theorem names, INCOMPATIBILITY.
  1499 
  1500   foo_simps  ~> foo.simps
  1501   foo_unfold ~> foo.unfold
  1502   foo_induct ~> foo.induct
  1503 
  1504 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1505 method and internal fixrec proofs now use the default simpset instead.
  1506 INCOMPATIBILITY.
  1507 
  1508 * The "contlub" predicate has been removed.  Proof scripts should use
  1509 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1510 
  1511 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1512 
  1513 * The constants cpair, cfst, and csnd have been removed in favor of
  1514 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1515 
  1516 
  1517 *** ML ***
  1518 
  1519 * Antiquotations for basic formal entities:
  1520 
  1521     @{class NAME}         -- type class
  1522     @{class_syntax NAME}  -- syntax representation of the above
  1523 
  1524     @{type_name NAME}     -- logical type
  1525     @{type_abbrev NAME}   -- type abbreviation
  1526     @{nonterminal NAME}   -- type of concrete syntactic category
  1527     @{type_syntax NAME}   -- syntax representation of any of the above
  1528 
  1529     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1530     @{const_abbrev NAME}  -- abbreviated constant
  1531     @{const_syntax NAME}  -- syntax representation of any of the above
  1532 
  1533 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1534 syntax constant (cf. 'syntax' command).
  1535 
  1536 * Antiquotation @{make_string} inlines a function to print arbitrary
  1537 values similar to the ML toplevel.  The result is compiler dependent
  1538 and may fall back on "?" in certain situations.
  1539 
  1540 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1541 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1542 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1543 not work with the asynchronous Isar document model.
  1544 
  1545 * Configuration options now admit dynamic default values, depending on
  1546 the context or even global references.
  1547 
  1548 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1549 uses an efficient external library if available (for Poly/ML).
  1550 
  1551 * Renamed some important ML structures, while keeping the old names
  1552 for some time as aliases within the structure Legacy:
  1553 
  1554   OuterKeyword  ~>  Keyword
  1555   OuterLex      ~>  Token
  1556   OuterParse    ~>  Parse
  1557   OuterSyntax   ~>  Outer_Syntax
  1558   PrintMode     ~>  Print_Mode
  1559   SpecParse     ~>  Parse_Spec
  1560   ThyInfo       ~>  Thy_Info
  1561   ThyLoad       ~>  Thy_Load
  1562   ThyOutput     ~>  Thy_Output
  1563   TypeInfer     ~>  Type_Infer
  1564 
  1565 Note that "open Legacy" simplifies porting of sources, but forgetting
  1566 to remove it again will complicate porting again in the future.
  1567 
  1568 * Most operations that refer to a global context are named
  1569 accordingly, e.g. Simplifier.global_context or
  1570 ProofContext.init_global.  There are some situations where a global
  1571 context actually works, but under normal circumstances one needs to
  1572 pass the proper local context through the code!
  1573 
  1574 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1575 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1576 Pretty.pp argument to merge, which is absent in the standard
  1577 Theory_Data version.
  1578 
  1579 * Sorts.certify_sort and derived "cert" operations for types and terms
  1580 no longer minimize sorts.  Thus certification at the boundary of the
  1581 inference kernel becomes invariant under addition of class relations,
  1582 which is an important monotonicity principle.  Sorts are now minimized
  1583 in the syntax layer only, at the boundary between the end-user and the
  1584 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1585 explicitly in rare situations.
  1586 
  1587 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1588 emphasize that this is in no way a standard operation.
  1589 INCOMPATIBILITY.
  1590 
  1591 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1592 usual for resolution.  Rare INCOMPATIBILITY.
  1593 
  1594 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1595 to emphasize that these only work in a global situation (which is
  1596 quite rare).
  1597 
  1598 * Curried take and drop in library.ML; negative length is interpreted
  1599 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1600 
  1601 * Proof terms: type substitutions on proof constants now use canonical
  1602 order of type variables.  INCOMPATIBILITY for tools working with proof
  1603 terms.
  1604 
  1605 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1606 may no longer carry premises.  User-level specifications are
  1607 transformed accordingly by Thm.add_axiom/add_def.
  1608 
  1609 
  1610 *** System ***
  1611 
  1612 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1613 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1614 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1615 
  1616 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1617 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1618 respectively.
  1619 
  1620 * Old lib/scripts/polyml-platform is superseded by the
  1621 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1622 variant, even on a 64 bit machine.  The following example setting
  1623 prefers 64 bit if available:
  1624 
  1625   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1626 
  1627 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1628 Isabelle/Scala layer for advanced prover interaction and integration.
  1629 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1630 component.
  1631 
  1632 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1633 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1634 similar to the default assignment of the document preparation system
  1635 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1636 provides some operations for direct access to the font without asking
  1637 the user for manual installation.
  1638 
  1639 
  1640 
  1641 New in Isabelle2009-1 (December 2009)
  1642 -------------------------------------
  1643 
  1644 *** General ***
  1645 
  1646 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1647 one backslash should be used, even in ML sources.
  1648 
  1649 
  1650 *** Pure ***
  1651 
  1652 * Locale interpretation propagates mixins along the locale hierarchy.
  1653 The currently only available mixins are the equations used to map
  1654 local definitions to terms of the target domain of an interpretation.
  1655 
  1656 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1657 loc" to print all interpretations of locale "loc" in the theory.
  1658 Interpretations in proofs are not shown.
  1659 
  1660 * Thoroughly revised locales tutorial.  New section on conditional
  1661 interpretation.
  1662 
  1663 * On instantiation of classes, remaining undefined class parameters
  1664 are formally declared.  INCOMPATIBILITY.
  1665 
  1666 
  1667 *** Document preparation ***
  1668 
  1669 * New generalized style concept for printing terms: @{foo (style) ...}
  1670 instead of @{foo_style style ...}  (old form is still retained for
  1671 backward compatibility).  Styles can be also applied for
  1672 antiquotations prop, term_type and typeof.
  1673 
  1674 
  1675 *** HOL ***
  1676 
  1677 * New proof method "smt" for a combination of first-order logic with
  1678 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1679 fixed-size bitvectors; there is also basic support for higher-order
  1680 features (esp. lambda abstractions).  It is an incomplete decision
  1681 procedure based on external SMT solvers using the oracle mechanism;
  1682 for the SMT solver Z3, this method is proof-producing.  Certificates
  1683 are provided to avoid calling the external solvers solely for
  1684 re-checking proofs.  Due to a remote SMT service there is no need for
  1685 installing SMT solvers locally.  See src/HOL/SMT.
  1686 
  1687 * New commands to load and prove verification conditions generated by
  1688 the Boogie program verifier or derived systems (e.g. the Verifying C
  1689 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1690 
  1691 * New counterexample generator tool 'nitpick' based on the Kodkod
  1692 relational model finder.  See src/HOL/Tools/Nitpick and
  1693 src/HOL/Nitpick_Examples.
  1694 
  1695 * New commands 'code_pred' and 'values' to invoke the predicate
  1696 compiler and to enumerate values of inductive predicates.
  1697 
  1698 * A tabled implementation of the reflexive transitive closure.
  1699 
  1700 * New implementation of quickcheck uses generic code generator;
  1701 default generators are provided for all suitable HOL types, records
  1702 and datatypes.  Old quickcheck can be re-activated importing theory
  1703 Library/SML_Quickcheck.
  1704 
  1705 * New testing tool Mirabelle for automated proof tools.  Applies
  1706 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1707 every proof step in a theory.  To be used in batch mode via the
  1708 "mirabelle" utility.
  1709 
  1710 * New proof method "sos" (sum of squares) for nonlinear real
  1711 arithmetic (originally due to John Harison). It requires theory
  1712 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1713 works well in practice on quantifier-free real arithmetic with +, -,
  1714 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1715 inequalities between polynomials.  It makes use of external
  1716 semidefinite programming solvers.  Method "sos" generates a
  1717 certificate that can be pasted into the proof thus avoiding the need
  1718 to call an external tool every time the proof is checked.  See
  1719 src/HOL/Library/Sum_Of_Squares.
  1720 
  1721 * New method "linarith" invokes existing linear arithmetic decision
  1722 procedure only.
  1723 
  1724 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1725 
  1726 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1727 Causes full type information to be output to the ATPs.  This slows
  1728 ATPs down considerably but eliminates a source of unsound "proofs"
  1729 that fail later.
  1730 
  1731 * New method "metisFT": A version of metis that uses full type
  1732 information in order to avoid failures of proof reconstruction.
  1733 
  1734 * New evaluator "approximate" approximates an real valued term using
  1735 the same method as the approximation method.
  1736 
  1737 * Method "approximate" now supports arithmetic expressions as
  1738 boundaries of intervals and implements interval splitting and Taylor
  1739 series expansion.
  1740 
  1741 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1742 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1743 
  1744 * New theory SupInf of the supremum and infimum operators for sets of
  1745 reals.
  1746 
  1747 * New theory Probability, which contains a development of measure
  1748 theory, eventually leading to Lebesgue integration and probability.
  1749 
  1750 * Extended Multivariate Analysis to include derivation and Brouwer's
  1751 fixpoint theorem.
  1752 
  1753 * Reorganization of number theory, INCOMPATIBILITY:
  1754   - new number theory development for nat and int, in theories Divides
  1755     and GCD as well as in new session Number_Theory
  1756   - some constants and facts now suffixed with _nat and _int
  1757     accordingly
  1758   - former session NumberTheory now named Old_Number_Theory, including
  1759     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1760   - moved theory Pocklington from src/HOL/Library to
  1761     src/HOL/Old_Number_Theory
  1762 
  1763 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1764 lcm of finite and infinite sets. It is shown that they form a complete
  1765 lattice.
  1766 
  1767 * Class semiring_div requires superclass no_zero_divisors and proof of
  1768 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1769 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1770 generalized to class semiring_div, subsuming former theorems
  1771 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1772 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1773 INCOMPATIBILITY.
  1774 
  1775 * Refinements to lattice classes and sets:
  1776   - less default intro/elim rules in locale variant, more default
  1777     intro/elim rules in class variant: more uniformity
  1778   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1779     le_inf_iff
  1780   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1781     sup_aci)
  1782   - renamed ACI to inf_sup_aci
  1783   - new class "boolean_algebra"
  1784   - class "complete_lattice" moved to separate theory
  1785     "Complete_Lattice"; corresponding constants (and abbreviations)
  1786     renamed and with authentic syntax:
  1787     Set.Inf ~>    Complete_Lattice.Inf
  1788     Set.Sup ~>    Complete_Lattice.Sup
  1789     Set.INFI ~>   Complete_Lattice.INFI
  1790     Set.SUPR ~>   Complete_Lattice.SUPR
  1791     Set.Inter ~>  Complete_Lattice.Inter
  1792     Set.Union ~>  Complete_Lattice.Union
  1793     Set.INTER ~>  Complete_Lattice.INTER
  1794     Set.UNION ~>  Complete_Lattice.UNION
  1795   - authentic syntax for
  1796     Set.Pow
  1797     Set.image
  1798   - mere abbreviations:
  1799     Set.empty               (for bot)
  1800     Set.UNIV                (for top)
  1801     Set.inter               (for inf, formerly Set.Int)
  1802     Set.union               (for sup, formerly Set.Un)
  1803     Complete_Lattice.Inter  (for Inf)
  1804     Complete_Lattice.Union  (for Sup)
  1805     Complete_Lattice.INTER  (for INFI)
  1806     Complete_Lattice.UNION  (for SUPR)
  1807   - object-logic definitions as far as appropriate
  1808 
  1809 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1810 Un_subset_iff are explicitly deleted as default simp rules; then also
  1811 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1812 deleted to achieve the desired effect.
  1813 
  1814 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1815 rules by default any longer; the same applies to min_max.inf_absorb1
  1816 etc.  INCOMPATIBILITY.
  1817 
  1818 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1819 pred_set_conv by default.  INCOMPATIBILITY.
  1820 
  1821 * Power operations on relations and functions are now one dedicated
  1822 constant "compow" with infix syntax "^^".  Power operation on
  1823 multiplicative monoids retains syntax "^" and is now defined generic
  1824 in class power.  INCOMPATIBILITY.
  1825 
  1826 * Relation composition "R O S" now has a more standard argument order:
  1827 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1828 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1829 break, since the O_assoc rule was not rewritten like this.  Fix using
  1830 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1831 
  1832 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1833 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1834 INCOMPATIBILITY.
  1835 
  1836 * Most rules produced by inductive and datatype package have mandatory
  1837 prefixes.  INCOMPATIBILITY.
  1838 
  1839 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1840 the attribute of the same name.  Each of the theorems in the list
  1841 DERIV_intros assumes composition with an additional function and
  1842 matches a variable to the derivative, which has to be solved by the
  1843 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1844 of most elementary terms.  Former Maclauren.DERIV_tac and
  1845 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1846 INCOMPATIBILITY.
  1847 
  1848 * Code generator attributes follow the usual underscore convention:
  1849     code_unfold     replaces    code unfold
  1850     code_post       replaces    code post
  1851     etc.
  1852   INCOMPATIBILITY.
  1853 
  1854 * Renamed methods:
  1855     sizechange -> size_change
  1856     induct_scheme -> induction_schema
  1857   INCOMPATIBILITY.
  1858 
  1859 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1860 INCOMPATIBILITY, use "undefined" directly.
  1861 
  1862 * Renamed theorems:
  1863     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1864     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1865     Suc_plus1 -> Suc_eq_plus1
  1866     *anti_sym -> *antisym*
  1867     vector_less_eq_def -> vector_le_def
  1868   INCOMPATIBILITY.
  1869 
  1870 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1871 INCOMPATIBILITY.
  1872 
  1873 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1874 INCOMPATIBILITY.
  1875 
  1876 
  1877 *** HOLCF ***
  1878 
  1879 * Theory Representable defines a class "rep" of domains that are
  1880 representable (via an ep-pair) in the universal domain type "udom".
  1881 Instances are provided for all type constructors defined in HOLCF.
  1882 
  1883 * The 'new_domain' command is a purely definitional version of the
  1884 domain package, for representable domains.  Syntax is identical to the
  1885 old domain package.  The 'new_domain' package also supports indirect
  1886 recursion using previously-defined type constructors.  See
  1887 src/HOLCF/ex/New_Domain.thy for examples.
  1888 
  1889 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1890 on the left-hand side of an equation, and then performs
  1891 simplification.  Rewriting is done using rules declared with the
  1892 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1893 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1894 
  1895 * The pattern-match compiler in 'fixrec' can now handle constructors
  1896 with HOL function types.  Pattern-match combinators for the Pair
  1897 constructor are pre-configured.
  1898 
  1899 * The 'fixrec' package now produces better fixed-point induction rules
  1900 for mutually-recursive definitions:  Induction rules have conclusions
  1901 of the form "P foo bar" instead of "P <foo, bar>".
  1902 
  1903 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1904 been renamed to "below".  The name "below" now replaces "less" in many
  1905 theorem names.  (Legacy theorem names using "less" are still supported
  1906 as well.)
  1907 
  1908 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1909 patterns can be used to generate strictness rules, or to make
  1910 functions more strict (much like the bang-patterns supported by the
  1911 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1912 examples.
  1913 
  1914 
  1915 *** ML ***
  1916 
  1917 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1918 errors and run-time exceptions, including detailed source positions.
  1919 
  1920 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1921 identified entries, with some additional information such as source
  1922 position, logical grouping etc.
  1923 
  1924 * Theory and context data is now introduced by the simplified and
  1925 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1926 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1927 copy operation) is still available for some time.
  1928 
  1929 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1930 provides a high-level programming interface to synchronized state
  1931 variables with atomic update.  This works via pure function
  1932 application within a critical section -- its runtime should be as
  1933 short as possible; beware of deadlocks if critical code is nested,
  1934 either directly or indirectly via other synchronized variables!
  1935 
  1936 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1937 wraps raw ML references, explicitly indicating their non-thread-safe
  1938 behaviour.  The Isar toplevel keeps this structure open, to
  1939 accommodate Proof General as well as quick and dirty interactive
  1940 experiments with references.
  1941 
  1942 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1943 parallel tactical reasoning.
  1944 
  1945 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1946 are similar to SUBPROOF, but are slightly more flexible: only the
  1947 specified parts of the subgoal are imported into the context, and the
  1948 body tactic may introduce new subgoals and schematic variables.
  1949 
  1950 * Old tactical METAHYPS, which does not observe the proof context, has
  1951 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1952 or Subgoal.FOCUS etc.
  1953 
  1954 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1955 functors have their own ML name space there is no point to mark them
  1956 separately.)  Minor INCOMPATIBILITY.
  1957 
  1958 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1959 
  1960 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1961 INCOMPATIBILITY.
  1962 
  1963 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1964 mode, which avoids critical setmp.
  1965 
  1966 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1967 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1968 Attrib/Method.setup introduced in Isabelle2009.
  1969 
  1970 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1971 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1972 last resort.  INCOMPATIBILITY.
  1973 
  1974 * Display.pretty_thm now requires a proper context (cf. former
  1975 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1976 or even Display.pretty_thm_without_context as last resort.
  1977 INCOMPATIBILITY.
  1978 
  1979 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1980 Syntax.pretty_typ/term directly, preferably with proper context
  1981 instead of global theory.
  1982 
  1983 
  1984 *** System ***
  1985 
  1986 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1987 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1988 usedir option -q.
  1989 
  1990 * Support for additional "Isabelle components" via etc/components, see
  1991 also the system manual.
  1992 
  1993 * The isabelle makeall tool now operates on all components with
  1994 IsaMakefile, not just hardwired "logics".
  1995 
  1996 * Removed "compress" option from isabelle-process and isabelle usedir;
  1997 this is always enabled.
  1998 
  1999 * Discontinued support for Poly/ML 4.x versions.
  2000 
  2001 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2002 on a given logic image.  This requires the lighttpd webserver and is
  2003 currently supported on Linux only.
  2004 
  2005 
  2006 
  2007 New in Isabelle2009 (April 2009)
  2008 --------------------------------
  2009 
  2010 *** General ***
  2011 
  2012 * Simplified main Isabelle executables, with less surprises on
  2013 case-insensitive file-systems (such as Mac OS).
  2014 
  2015   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2016     "isatool."
  2017 
  2018   - The former "isabelle" alias for "isabelle-process" has been
  2019     removed (should rarely occur to regular users).
  2020 
  2021   - The former "isabelle-interface" and its alias "Isabelle" have been
  2022     removed (interfaces are now regular Isabelle tools).
  2023 
  2024 Within scripts and make files, the Isabelle environment variables
  2025 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2026 respectively.  (The latter are still available as legacy feature.)
  2027 
  2028 The old isabelle-interface wrapper could react in confusing ways if
  2029 the interface was uninstalled or changed otherwise.  Individual
  2030 interface tool configuration is now more explicit, see also the
  2031 Isabelle system manual.  In particular, Proof General is now available
  2032 via "isabelle emacs".
  2033 
  2034 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2035 purge installed copies of Isabelle executables and re-run "isabelle
  2036 install -p ...", or use symlinks.
  2037 
  2038 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2039 old ~/isabelle, which was slightly non-standard and apt to cause
  2040 surprises on case-insensitive file-systems (such as Mac OS).
  2041 
  2042 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2043 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2044 care is required when using older releases of Isabelle.  Note that
  2045 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2046 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2047 
  2048 * Proofs of fully specified statements are run in parallel on
  2049 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2050 a regular 4-core machine, if the initial heap space is made reasonably
  2051 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2052 
  2053 * The main reference manuals ("isar-ref", "implementation", and
  2054 "system") have been updated and extended.  Formally checked references
  2055 as hyperlinks are now available uniformly.
  2056 
  2057 
  2058 *** Pure ***
  2059 
  2060 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2061 respects.  The most important changes are listed below.  See the
  2062 Tutorial on Locales ("locales" manual) for details.
  2063 
  2064 - In locale expressions, instantiation replaces renaming.  Parameters
  2065 must be declared in a for clause.  To aid compatibility with previous
  2066 parameter inheritance, in locale declarations, parameters that are not
  2067 'touched' (instantiation position "_" or omitted) are implicitly added
  2068 with their syntax at the beginning of the for clause.
  2069 
  2070 - Syntax from abbreviations and definitions in locales is available in
  2071 locale expressions and context elements.  The latter is particularly
  2072 useful in locale declarations.
  2073 
  2074 - More flexible mechanisms to qualify names generated by locale
  2075 expressions.  Qualifiers (prefixes) may be specified in locale
  2076 expressions, and can be marked as mandatory (syntax: "name!:") or
  2077 optional (syntax "name?:").  The default depends for plain "name:"
  2078 depends on the situation where a locale expression is used: in
  2079 commands 'locale' and 'sublocale' prefixes are optional, in
  2080 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2081 implicit qualifiers derived from the parameter names of a locale are
  2082 no longer generated.
  2083 
  2084 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2085 instantiation clause in "interpretation" and "interpret" (square
  2086 brackets) is no longer available.  Use locale expressions.
  2087 
  2088 - When converting proof scripts, mandatory qualifiers in
  2089 'interpretation' and 'interpret' should be retained by default, even
  2090 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2091 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2092 in locale expressions range over a single locale instance only.
  2093 
  2094 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2095 In existing theorem specifications replace the includes element by the
  2096 respective context elements of the included locale, omitting those
  2097 that are already present in the theorem specification.  Multiple
  2098 assume elements of a locale should be replaced by a single one
  2099 involving the locale predicate.  In the proof body, declarations (most
  2100 notably theorems) may be regained by interpreting the respective
  2101 locales in the proof context as required (command "interpret").
  2102 
  2103 If using "includes" in replacement of a target solely because the
  2104 parameter types in the theorem are not as general as in the target,
  2105 consider declaring a new locale with additional type constraints on
  2106 the parameters (context element "constrains").
  2107 
  2108 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2109 
  2110 - Locale interpretation commands no longer attempt to simplify goal.
  2111 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2112 methods intro_locales and unfold_locales to clarify.
  2113 
  2114 - Locale interpretation commands no longer accept interpretation
  2115 attributes.  INCOMPATIBILITY.
  2116 
  2117 * Class declaration: so-called "base sort" must not be given in import
  2118 list any longer, but is inferred from the specification.  Particularly
  2119 in HOL, write
  2120 
  2121     class foo = ...
  2122 
  2123 instead of
  2124 
  2125     class foo = type + ...
  2126 
  2127 * Class target: global versions of theorems stemming do not carry a
  2128 parameter prefix any longer.  INCOMPATIBILITY.
  2129 
  2130 * Class 'instance' command no longer accepts attached definitions.
  2131 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2132 
  2133 * Recovered hiding of consts, which was accidentally broken in
  2134 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2135 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2136 
  2137 * Slightly more coherent Pure syntax, with updated documentation in
  2138 isar-ref manual.  Removed locales meta_term_syntax and
  2139 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2140 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2141 directly in regular applications.
  2142 
  2143 * There is a new syntactic category "float_const" for signed decimal
  2144 fractions (e.g. 123.45 or -123.45).
  2145 
  2146 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2147 interface with 'setup' command instead.
  2148 
  2149 * Command 'local_setup' is similar to 'setup', but operates on a local
  2150 theory context.
  2151 
  2152 * The 'axiomatization' command now only works within a global theory
  2153 context.  INCOMPATIBILITY.
  2154 
  2155 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2156 hypotheses.  Sorts required in the course of reasoning need to be
  2157 covered by the constraints in the initial statement, completed by the
  2158 type instance information of the background theory.  Non-trivial sort
  2159 hypotheses, which rarely occur in practice, may be specified via
  2160 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2161 
  2162   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2163 
  2164 The result contains an implicit sort hypotheses as before --
  2165 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2166 normalization.
  2167 
  2168 * Generalized Isar history, with support for linear undo, direct state
  2169 addressing etc.
  2170 
  2171 * Changed defaults for unify configuration options:
  2172 
  2173   unify_trace_bound = 50 (formerly 25)
  2174   unify_search_bound = 60 (formerly 30)
  2175 
  2176 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2177 
  2178   a) On theory merge, the last set of code equations for a particular
  2179      constant is taken (in accordance with the policy applied by other
  2180      parts of the code generator framework).
  2181 
  2182   b) Code equations stemming from explicit declarations (e.g. code
  2183      attribute) gain priority over default code equations stemming
  2184      from definition, primrec, fun etc.
  2185 
  2186 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2187 
  2188 * Unified theorem tables for both code generators.  Thus [code
  2189 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2190 
  2191 * Command 'find_consts' searches for constants based on type and name
  2192 patterns, e.g.
  2193 
  2194     find_consts "_ => bool"
  2195 
  2196 By default, matching is against subtypes, but it may be restricted to
  2197 the whole type.  Searching by name is possible.  Multiple queries are
  2198 conjunctive and queries may be negated by prefixing them with a
  2199 hyphen:
  2200 
  2201     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2202 
  2203 * New 'find_theorems' criterion "solves" matches theorems that
  2204 directly solve the current goal (modulo higher-order unification).
  2205 
  2206 * Auto solve feature for main theorem statements: whenever a new goal
  2207 is stated, "find_theorems solves" is called; any theorems that could
  2208 solve the lemma directly are listed as part of the goal state.
  2209 Cf. associated options in Proof General Isabelle settings menu,
  2210 enabled by default, with reasonable timeout for pathological cases of
  2211 higher-order unification.
  2212 
  2213 
  2214 *** Document preparation ***
  2215 
  2216 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2217 demanding keyword 'by' and supporting the full method expression
  2218 syntax just like the Isar command 'by'.
  2219 
  2220 
  2221 *** HOL ***
  2222 
  2223 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2224 points Main and Complex_Main remain as before.
  2225 
  2226 * Logic image HOL-Plain provides a minimal HOL with the most important
  2227 tools available (inductive, datatype, primrec, ...).  This facilitates
  2228 experimentation and tool development.  Note that user applications
  2229 (and library theories) should never refer to anything below theory
  2230 Main, as before.
  2231 
  2232 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2233 experimentation due to shorter build times.
  2234 
  2235 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2236 were previously part of former HOL-Complex.  Entry point Hyperreal
  2237 remains valid, but theories formerly using Complex_Main should now use
  2238 new entry point Hypercomplex.
  2239 
  2240 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2241 Posix processes.  Avoids potentially expensive forking of the ML
  2242 process.  New thread-based implementation also works on non-Unix
  2243 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2244 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2245 commands are covered in the isar-ref manual.
  2246 
  2247 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2248 sledgehammer without local ATP installation (Vampire etc.). Other
  2249 provers may be included via suitable ML wrappers, see also
  2250 src/HOL/ATP_Linkup.thy.
  2251 
  2252 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2253 menu.
  2254 
  2255 * The metis method no longer fails because the theorem is too trivial
  2256 (contains the empty clause).
  2257 
  2258 * The metis method now fails in the usual manner, rather than raising
  2259 an exception, if it determines that it cannot prove the theorem.
  2260 
  2261 * Method "coherent" implements a prover for coherent logic (see also
  2262 src/Tools/coherent.ML).
  2263 
  2264 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2265 "undefined" is the right choice to replace "arbitrary", though
  2266 logically there is no difference.  INCOMPATIBILITY.
  2267 
  2268 * Command "value" now integrates different evaluation mechanisms.  The
  2269 result of the first successful evaluation mechanism is printed.  In
  2270 square brackets a particular named evaluation mechanisms may be
  2271 specified (currently, [SML], [code] or [nbe]).  See further
  2272 src/HOL/ex/Eval_Examples.thy.
  2273 
  2274 * Normalization by evaluation now allows non-leftlinear equations.
  2275 Declare with attribute [code nbe].
  2276 
  2277 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2278 as the structured Isar versions "cases" and "induct", cf. the
  2279 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2280 are now presented as a list of individual projections
  2281 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2282 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2283 rare situations a different rule is selected --- notably nested tuple
  2284 elimination instead of former prod.exhaust: use explicit (case_tac t
  2285 rule: prod.exhaust) here.
  2286 
  2287 * Attributes "cases", "induct", "coinduct" support "del" option.
  2288 
  2289 * Removed fact "case_split_thm", which duplicates "case_split".
  2290 
  2291 * The option datatype has been moved to a new theory Option.  Renamed
  2292 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2293 
  2294 * New predicate "strict_mono" classifies strict functions on partial
  2295 orders.  With strict functions on linear orders, reasoning about
  2296 (in)equalities is facilitated by theorems "strict_mono_eq",
  2297 "strict_mono_less_eq" and "strict_mono_less".
  2298 
  2299 * Some set operations are now proper qualified constants with
  2300 authentic syntax.  INCOMPATIBILITY:
  2301 
  2302     op Int ~>   Set.Int
  2303     op Un ~>    Set.Un
  2304     INTER ~>    Set.INTER
  2305     UNION ~>    Set.UNION
  2306     Inter ~>    Set.Inter
  2307     Union ~>    Set.Union
  2308     {} ~>       Set.empty
  2309     UNIV ~>     Set.UNIV
  2310 
  2311 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2312 theory Set.
  2313 
  2314 * Auxiliary class "itself" has disappeared -- classes without any
  2315 parameter are treated as expected by the 'class' command.
  2316 
  2317 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2318 
  2319 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2320 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2321 
  2322 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2323 method "approximation".  It proves formulas on real values by using
  2324 interval arithmetic.  In the formulas are also the transcendental
  2325 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2326 allowed. For examples see
  2327 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2328 
  2329 * Theory "Reflection" now resides in HOL/Library.
  2330 
  2331 * Entry point to Word library now simply named "Word".
  2332 INCOMPATIBILITY.
  2333 
  2334 * Made source layout more coherent with logical distribution
  2335 structure:
  2336 
  2337     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2338     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2339     src/HOL/Library/GCD.thy ~> src/HOL/
  2340     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2341     src/HOL/Library/Parity.thy ~> src/HOL/
  2342     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2343     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2344     src/HOL/Real/Lubs.thy ~> src/HOL/
  2345     src/HOL/Real/PReal.thy ~> src/HOL/
  2346     src/HOL/Real/Rational.thy ~> src/HOL/
  2347     src/HOL/Real/RComplete.thy ~> src/HOL/
  2348     src/HOL/Real/RealDef.thy ~> src/HOL/
  2349     src/HOL/Real/RealPow.thy ~> src/HOL/
  2350     src/HOL/Real/Real.thy ~> src/HOL/
  2351     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2352     src/HOL/Complex/Complex.thy ~> src/HOL/
  2353     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2354     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2355     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2356     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2357     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2358     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2359     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2360     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2361     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2362     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2363     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2364     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2365     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2366     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2367     src/HOL/Real/Float ~> src/HOL/Library/
  2368     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2369     src/HOL/Real/RealVector.thy ~> src/HOL/
  2370 
  2371     src/HOL/arith_data.ML ~> src/HOL/Tools
  2372     src/HOL/hologic.ML ~> src/HOL/Tools
  2373     src/HOL/simpdata.ML ~> src/HOL/Tools
  2374     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2375     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2376     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2377     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2378     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2379     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2380     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2381 
  2382     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2383     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2384     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2385     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2386     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2387     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2388 
  2389 * If methods "eval" and "evaluation" encounter a structured proof
  2390 state with !!/==>, only the conclusion is evaluated to True (if
  2391 possible), avoiding strange error messages.
  2392 
  2393 * Method "sizechange" automates termination proofs using (a
  2394 modification of) the size-change principle.  Requires SAT solver.  See
  2395 src/HOL/ex/Termination.thy for examples.
  2396 
  2397 * Simplifier: simproc for let expressions now unfolds if bound
  2398 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2399 
  2400 * Method "arith": Linear arithmetic now ignores all inequalities when
  2401 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2402 
  2403 * New attribute "arith" for facts that should always be used
  2404 automatically by arithmetic. It is intended to be used locally in
  2405 proofs, e.g.
  2406 
  2407   assumes [arith]: "x > 0"
  2408 
  2409 Global usage is discouraged because of possible performance impact.
  2410 
  2411 * New classes "top" and "bot" with corresponding operations "top" and
  2412 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2413 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2414 
  2415 * Changed definition lemma "less_fun_def" in order to provide an
  2416 instance for preorders on functions; use lemma "less_le" instead.
  2417 INCOMPATIBILITY.
  2418 
  2419 * Theory Orderings: class "wellorder" moved here, with explicit
  2420 induction rule "less_induct" as assumption.  For instantiation of
  2421 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2422 INCOMPATIBILITY.
  2423 
  2424 * Theory Orderings: added class "preorder" as superclass of "order".
  2425 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2426 etc. slightly changed.  Some theorems named order_class.* now named
  2427 preorder_class.*.
  2428 
  2429 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2430 "diag" to "Id_on".
  2431 
  2432 * Theory Finite_Set: added a new fold combinator of type
  2433 
  2434   ('a => 'b => 'b) => 'b => 'a set => 'b
  2435 
  2436 Occasionally this is more convenient than the old fold combinator
  2437 which is now defined in terms of the new one and renamed to
  2438 fold_image.
  2439 
  2440 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2441 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2442 extended with further lemmas!).  At the moment both still exist but
  2443 the former will disappear at some point.
  2444 
  2445 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2446 class recpower.  Type-specific simp rules for various recpower types
  2447 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2448 
  2449 rat_power_0    -> power_0
  2450 rat_power_Suc  -> power_Suc
  2451 realpow_0      -> power_0
  2452 realpow_Suc    -> power_Suc
  2453 complexpow_0   -> power_0
  2454 complexpow_Suc -> power_Suc
  2455 power_poly_0   -> power_0
  2456 power_poly_Suc -> power_Suc
  2457 
  2458 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2459 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2460 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2461 of lemmas from Divides has been generalized from nat to class
  2462 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2463 renames resulting from duplicate elimination:
  2464 
  2465     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2466     zero_dvd_iff ~>         dvd_0_left_iff
  2467     dvd_0 ~>                dvd_0_right
  2468     DIVISION_BY_ZERO_DIV ~> div_by_0
  2469     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2470     mult_div ~>             div_mult_self2_is_id
  2471     mult_mod ~>             mod_mult_self2_is_0
  2472 
  2473 * Theory IntDiv: removed many lemmas that are instances of class-based
  2474 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2475 rename old lemmas as follows:
  2476 
  2477 dvd_diff               -> nat_dvd_diff
  2478 dvd_zminus_iff         -> dvd_minus_iff
  2479 mod_add1_eq            -> mod_add_eq
  2480 mod_mult1_eq           -> mod_mult_right_eq
  2481 mod_mult1_eq'          -> mod_mult_left_eq
  2482 mod_mult_distrib_mod   -> mod_mult_eq
  2483 nat_mod_add_left_eq    -> mod_add_left_eq
  2484 nat_mod_add_right_eq   -> mod_add_right_eq
  2485 nat_mod_div_trivial    -> mod_div_trivial
  2486 nat_mod_mod_trivial    -> mod_mod_trivial
  2487 zdiv_zadd_self1        -> div_add_self1
  2488 zdiv_zadd_self2        -> div_add_self2
  2489 zdiv_zmult_self1       -> div_mult_self2_is_id
  2490 zdiv_zmult_self2       -> div_mult_self1_is_id
  2491 zdvd_triv_left         -> dvd_triv_left
  2492 zdvd_triv_right        -> dvd_triv_right
  2493 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2494 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2495 zmod_zadd_left_eq      -> mod_add_left_eq
  2496 zmod_zadd_right_eq     -> mod_add_right_eq
  2497 zmod_zadd_self1        -> mod_add_self1
  2498 zmod_zadd_self2        -> mod_add_self2
  2499 zmod_zadd1_eq          -> mod_add_eq
  2500 zmod_zdiff1_eq         -> mod_diff_eq
  2501 zmod_zdvd_zmod         -> mod_mod_cancel
  2502 zmod_zmod_cancel       -> mod_mod_cancel
  2503 zmod_zmult_self1       -> mod_mult_self2_is_0
  2504 zmod_zmult_self2       -> mod_mult_self1_is_0
  2505 zmod_1                 -> mod_by_1
  2506 zdiv_1                 -> div_by_1
  2507 zdvd_abs1              -> abs_dvd_iff
  2508 zdvd_abs2              -> dvd_abs_iff
  2509 zdvd_refl              -> dvd_refl
  2510 zdvd_trans             -> dvd_trans
  2511 zdvd_zadd              -> dvd_add
  2512 zdvd_zdiff             -> dvd_diff
  2513 zdvd_zminus_iff        -> dvd_minus_iff
  2514 zdvd_zminus2_iff       -> minus_dvd_iff
  2515 zdvd_zmultD            -> dvd_mult_right
  2516 zdvd_zmultD2           -> dvd_mult_left
  2517 zdvd_zmult_mono        -> mult_dvd_mono
  2518 zdvd_0_right           -> dvd_0_right
  2519 zdvd_0_left            -> dvd_0_left_iff
  2520 zdvd_1_left            -> one_dvd
  2521 zminus_dvd_iff         -> minus_dvd_iff
  2522 
  2523 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2524 
  2525 * The real numbers offer decimal input syntax: 12.34 is translated
  2526 into 1234/10^2. This translation is not reversed upon output.
  2527 
  2528 * Theory Library/Polynomial defines an abstract type 'a poly of
  2529 univariate polynomials with coefficients of type 'a.  In addition to
  2530 the standard ring operations, it also supports div and mod.  Code
  2531 generation is also supported, using list-style constructors.
  2532 
  2533 * Theory Library/Inner_Product defines a class of real_inner for real
  2534 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2535 => real.  Class real_inner is a subclass of real_normed_vector from
  2536 theory RealVector.
  2537 
  2538 * Theory Library/Product_Vector provides instances for the product
  2539 type 'a * 'b of several classes from RealVector and Inner_Product.
  2540 Definitions of addition, subtraction, scalar multiplication, norms,
  2541 and inner products are included.
  2542 
  2543 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2544 addition to the field operations, numerals and case syntax are also
  2545 supported.
  2546 
  2547 * Theory Library/Diagonalize provides constructive version of Cantor's
  2548 first diagonalization argument.
  2549 
  2550 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2551 zlcm (for int); carried together from various gcd/lcm developements in
  2552 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2553 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2554 may recover tupled syntax as follows:
  2555 
  2556     hide (open) const gcd
  2557     abbreviation gcd where
  2558       "gcd == (%(a, b). GCD.gcd a b)"
  2559     notation (output)
  2560       GCD.gcd ("gcd '(_, _')")
  2561 
  2562 The same works for lcm, zgcd, zlcm.
  2563 
  2564 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2565 instantiations for algebraic structures.  Removed some duplicate
  2566 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2567 
  2568 * ML antiquotation @{code} takes a constant as argument and generates
  2569 corresponding code in background and inserts name of the corresponding
  2570 resulting ML value/function/datatype constructor binding in place.
  2571 All occurrences of @{code} with a single ML block are generated
  2572 simultaneously.  Provides a generic and safe interface for
  2573 instrumentalizing code generation.  See
  2574 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2575 In future you ought to refrain from ad-hoc compiling generated SML
  2576 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2577 cannot refer to constants for which user-defined serializations are
  2578 set.  Refer to the corresponding ML counterpart directly in that
  2579 cases.
  2580 
  2581 * Command 'rep_datatype': instead of theorem names the command now
  2582 takes a list of terms denoting the constructors of the type to be
  2583 represented as datatype.  The characteristic theorems have to be
  2584 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2585 have disappeared in favour of existing ones:
  2586 
  2587     unit_induct                 ~> unit.induct
  2588     prod_induct                 ~> prod.induct
  2589     sum_induct                  ~> sum.induct
  2590     Suc_Suc_eq                  ~> nat.inject
  2591     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2592 
  2593 
  2594 *** HOL-Algebra ***
  2595 
  2596 * New locales for orders and lattices where the equivalence relation
  2597 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2598 locales use a record structure with field eq for the equivalence.
  2599 
  2600 * New theory of factorial domains.
  2601 
  2602 * Units_l_inv and Units_r_inv are now simp rules by default.
  2603 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2604 and/or r_inv will now also require deletion of these lemmas.
  2605 
  2606 * Renamed the following theorems, INCOMPATIBILITY:
  2607 
  2608 UpperD ~> Upper_memD
  2609 LowerD ~> Lower_memD
  2610 least_carrier ~> least_closed
  2611 greatest_carrier ~> greatest_closed
  2612 greatest_Lower_above ~> greatest_Lower_below
  2613 one_zero ~> carrier_one_zero
  2614 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2615 
  2616 
  2617 *** HOL-Nominal ***
  2618 
  2619 * Nominal datatypes can now contain type-variables.
  2620 
  2621 * Commands 'nominal_inductive' and 'equivariance' work with local
  2622 theory targets.
  2623 
  2624 * Nominal primrec can now works with local theory targets and its
  2625 specification syntax now conforms to the general format as seen in
  2626 'inductive' etc.
  2627 
  2628 * Method "perm_simp" honours the standard simplifier attributes
  2629 (no_asm), (no_asm_use) etc.
  2630 
  2631 * The new predicate #* is defined like freshness, except that on the
  2632 left hand side can be a set or list of atoms.
  2633 
  2634 * Experimental command 'nominal_inductive2' derives strong induction
  2635 principles for inductive definitions.  In contrast to
  2636 'nominal_inductive', which can only deal with a fixed number of
  2637 binders, it can deal with arbitrary expressions standing for sets of
  2638 atoms to be avoided.  The only inductive definition we have at the
  2639 moment that needs this generalisation is the typing rule for Lets in
  2640 the algorithm W:
  2641 
  2642  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2643  -----------------------------------------------------------------
  2644          Gamma |- Let x be t1 in t2 : T2
  2645 
  2646 In this rule one wants to avoid all the binders that are introduced by
  2647 "close Gamma T1".  We are looking for other examples where this
  2648 feature might be useful.  Please let us know.
  2649 
  2650 
  2651 *** HOLCF ***
  2652 
  2653 * Reimplemented the simplification procedure for proving continuity
  2654 subgoals.  The new simproc is extensible; users can declare additional
  2655 continuity introduction rules with the attribute [cont2cont].
  2656 
  2657 * The continuity simproc now uses a different introduction rule for
  2658 solving continuity subgoals on terms with lambda abstractions.  In
  2659 some rare cases the new simproc may fail to solve subgoals that the
  2660 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2661 Potential INCOMPATIBILITY.
  2662 
  2663 * Command 'fixrec': specification syntax now conforms to the general
  2664 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2665 examples.  INCOMPATIBILITY.
  2666 
  2667 
  2668 *** ZF ***
  2669 
  2670 * Proof of Zorn's Lemma for partial orders.
  2671 
  2672 
  2673 *** ML ***
  2674 
  2675 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2676 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2677 depends on multithreading, so timouts will not work before Poly/ML
  2678 5.2.1!
  2679 
  2680 * High-level support for concurrent ML programming, see
  2681 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2682 particularly convenient to organize independent functional
  2683 computations.  The concept of "synchronized variables" provides a
  2684 higher-order interface for components with shared state, avoiding the
  2685 delicate details of mutexes and condition variables.  (Requires
  2686 Poly/ML 5.2.1 or later.)
  2687 
  2688 * ML bindings produced via Isar commands are stored within the Isar
  2689 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2690 become thread-safe and work with undo as expected (concerning
  2691 top-level bindings, not side-effects on global references).
  2692 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2693 compiler at runtime; really global bindings need to be given outside a
  2694 theory.  (Requires Poly/ML 5.2 or later.)
  2695 
  2696 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2697 context.  Top-level ML bindings are stored within the proof context in
  2698 a purely sequential fashion, disregarding the nested proof structure.
  2699 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2700 proof.  (Requires Poly/ML 5.2 or later.)
  2701 
  2702 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2703 and Method.setup, as well as Isar commands 'attribute_setup' and
  2704 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2705 existing code accordingly, or use plain 'setup' together with old
  2706 Method.add_method.
  2707 
  2708 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2709 to 'a -> thm, while results are always tagged with an authentic oracle
  2710 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2711 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2712 accordingly.  Note that extra performance may be gained by producing
  2713 the cterm carefully, avoiding slow Thm.cterm_of.
  2714 
  2715 * Simplified interface for defining document antiquotations via
  2716 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2717 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2718 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2719 examples.
  2720 
  2721 * More systematic treatment of long names, abstract name bindings, and
  2722 name space operations.  Basic operations on qualified names have been
  2723 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2724 Long_Name.append.  Old type bstring has been mostly replaced by
  2725 abstract type binding (see structure Binding), which supports precise
  2726 qualification by packages and local theory targets, as well as proper
  2727 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2728 bstring values into Binding.name, or better pass through abstract
  2729 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2730 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2731 
  2732 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2733 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2734 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2735 
  2736 * Disposed old type and term read functions (Sign.read_def_typ,
  2737 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2738 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2739 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2740 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2741 resort for legacy applications.
  2742 
  2743 * Disposed old declarations, tactics, tactic combinators that refer to
  2744 the simpset or claset of an implicit theory (such as Addsimps,
  2745 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2746 embedded ML text, or local_simpset_of with a proper context passed as
  2747 explicit runtime argument.
  2748 
  2749 * Rules and tactics that read instantiations (read_instantiate,
  2750 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2751 context, which is required for parsing and type-checking.  Moreover,
  2752 the variables are specified as plain indexnames, not string encodings
  2753 thereof.  INCOMPATIBILITY.
  2754 
  2755 * Generic Toplevel.add_hook interface allows to analyze the result of
  2756 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2757 for theorem dependency output of transactions resulting in a new
  2758 theory state.
  2759 
  2760 * ML antiquotations: block-structured compilation context indicated by
  2761 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2762 
  2763   @{binding name}                         - basic name binding
  2764   @{let ?pat = term}                      - term abbreviation (HO matching)
  2765   @{note name = fact}                     - fact abbreviation
  2766   @{thm fact}                             - singleton fact (with attributes)
  2767   @{thms fact}                            - general fact (with attributes)
  2768   @{lemma prop by method}                 - singleton goal
  2769   @{lemma prop by meth1 meth2}            - singleton goal
  2770   @{lemma prop1 ... propN by method}      - general goal
  2771   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2772   @{lemma (open) ...}                     - open derivation
  2773 
  2774 
  2775 *** System ***
  2776 
  2777 * The Isabelle "emacs" tool provides a specific interface to invoke
  2778 Proof General / Emacs, with more explicit failure if that is not
  2779 installed (the old isabelle-interface script silently falls back on
  2780 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2781 installation location of the Proof General distribution.
  2782 
  2783 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2784 the Isabelle process into a JVM/Scala application.  See
  2785 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2786 process wrapper has been discontinued.)
  2787 
  2788 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2789 
  2790 * Various status messages (with exact source position information) are
  2791 emitted, if proper markup print mode is enabled.  This allows
  2792 user-interface components to provide detailed feedback on internal
  2793 prover operations.
  2794 
  2795 
  2796 
  2797 New in Isabelle2008 (June 2008)
  2798 -------------------------------
  2799 
  2800 *** General ***
  2801 
  2802 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2803 and updated, with formally checked references as hyperlinks.
  2804 
  2805 * Theory loader: use_thy (and similar operations) no longer set the
  2806 implicit ML context, which was occasionally hard to predict and in
  2807 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2808 provides a proper context already.
  2809 
  2810 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2811 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2812 'use' within a theory file will do the job.
  2813 
  2814 * Name space merge now observes canonical order, i.e. the second space
  2815 is inserted into the first one, while existing entries in the first
  2816 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2817 swap theory imports.
  2818 
  2819 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2820 INCOMPATIBILITY in identifier syntax etc.
  2821 
  2822 * Outer syntax: string tokens no longer admit escaped white space,
  2823 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2824 white space without escapes.
  2825 
  2826 * Outer syntax: string tokens may contain arbitrary character codes
  2827 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2828 "foo_bar".
  2829 
  2830 
  2831 *** Pure ***
  2832 
  2833 * Context-dependent token translations.  Default setup reverts locally
  2834 fixed variables, and adds hilite markup for undeclared frees.
  2835 
  2836 * Unused theorems can be found using the new command 'unused_thms'.
  2837 There are three ways of invoking it:
  2838 
  2839 (1) unused_thms
  2840      Only finds unused theorems in the current theory.
  2841 
  2842 (2) unused_thms thy_1 ... thy_n -
  2843      Finds unused theorems in the current theory and all of its ancestors,
  2844      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2845 
  2846 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2847      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2848      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2849      their ancestors.
  2850 
  2851 In order to increase the readability of the list produced by
  2852 unused_thms, theorems that have been created by a particular instance
  2853 of a theory command such as 'inductive' or 'function' are considered
  2854 to belong to the same "group", meaning that if at least one theorem in
  2855 this group is used, the other theorems in the same group are no longer
  2856 reported as unused.  Moreover, if all theorems in the group are
  2857 unused, only one theorem in the group is displayed.
  2858 
  2859 Note that proof objects have to be switched on in order for
  2860 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2861 usually the case when using Proof General with the default settings).
  2862 
  2863 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2864 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2865 duplicate fact bindings, or even accidental fact duplications.  Note
  2866 that tools may maintain dynamically scoped facts systematically, using
  2867 PureThy.add_thms_dynamic.
  2868 
  2869 * Command 'hide' now allows to hide from "fact" name space as well.
  2870 
  2871 * Eliminated destructive theorem database, simpset, claset, and
  2872 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2873 update of theories within ML code.
  2874 
  2875 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2876 INCOMPATIBILITY, object-logics depending on former Pure require
  2877 additional setup PureThy.old_appl_syntax_setup; object-logics
  2878 depending on former CPure need to refer to Pure.
  2879 
  2880 * Commands 'use' and 'ML' are now purely functional, operating on
  2881 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2882 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2883 INCOMPATIBILITY.
  2884 
  2885 * Command 'setup': discontinued implicit version with ML reference.
  2886 
  2887 * Instantiation target allows for simultaneous specification of class
  2888 instance operations together with an instantiation proof.
  2889 Type-checking phase allows to refer to class operations uniformly.
  2890 See src/HOL/Complex/Complex.thy for an Isar example and
  2891 src/HOL/Library/Eval.thy for an ML example.
  2892 
  2893 * Indexing of literal facts: be more serious about including only
  2894 facts from the visible specification/proof context, but not the
  2895 background context (locale etc.).  Affects `prop` notation and method
  2896 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2897 situations.
  2898 
  2899 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2900 "(open)" option, which used to expose internal bound variables to the
  2901 proof text.
  2902 
  2903 * Isar statements: removed obsolete case "rule_context".
  2904 INCOMPATIBILITY, better use explicit fixes/assumes.
  2905 
  2906 * Locale proofs: default proof step now includes 'unfold_locales';
  2907 hence 'proof' without argument may be used to unfold locale
  2908 predicates.
  2909 
  2910 
  2911 *** Document preparation ***
  2912 
  2913 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2914 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2915 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2916 spot); renamed link color from "darkblue" to "linkcolor" (default
  2917 value unchanged, can be redefined via \definecolor); no longer sets
  2918 "a4paper" option (unnecessary or even intrusive).
  2919 
  2920 * Antiquotation @{lemma A method} proves proposition A by the given
  2921 method (either a method name or a method name plus (optional) method
  2922 arguments in parentheses) and prints A just like @{prop A}.
  2923 
  2924 
  2925 *** HOL ***
  2926 
  2927 * New primrec package.  Specification syntax conforms in style to
  2928 definition/function/....  No separate induction rule is provided.  The
  2929 "primrec" command distinguishes old-style and new-style specifications
  2930 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2931 When adjusting theories, beware: constants stemming from new-style
  2932 primrec specifications have authentic syntax.
  2933 
  2934 * Metis prover is now an order of magnitude faster, and also works
  2935 with multithreading.
  2936 
  2937 * Metis: the maximum number of clauses that can be produced from a
  2938 theorem is now given by the attribute max_clauses.  Theorems that
  2939 exceed this number are ignored, with a warning printed.
  2940 
  2941 * Sledgehammer no longer produces structured proofs by default. To
  2942 enable, declare [[sledgehammer_full = true]].  Attributes
  2943 reconstruction_modulus, reconstruction_sorts renamed
  2944 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2945 
  2946 * Method "induct_scheme" derives user-specified induction rules
  2947 from well-founded induction and completeness of patterns. This factors
  2948 out some operations that are done internally by the function package
  2949 and makes them available separately.  See
  2950 src/HOL/ex/Induction_Scheme.thy for examples.
  2951 
  2952 * More flexible generation of measure functions for termination
  2953 proofs: Measure functions can be declared by proving a rule of the
  2954 form "is_measure f" and giving it the [measure_function] attribute.
  2955 The "is_measure" predicate is logically meaningless (always true), and
  2956 just guides the heuristic.  To find suitable measure functions, the
  2957 termination prover sets up the goal "is_measure ?f" of the appropriate
  2958 type and generates all solutions by prolog-style backwards proof using
  2959 the declared rules.
  2960 
  2961 This setup also deals with rules like 
  2962 
  2963   "is_measure f ==> is_measure (list_size f)"
  2964 
  2965 which accommodates nested datatypes that recurse through lists.
  2966 Similar rules are predeclared for products and option types.
  2967 
  2968 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2969 
  2970   INCOMPATIBILITIES:
  2971 
  2972   - Definitions of overloaded constants on sets have to be replaced by
  2973     definitions on => and bool.
  2974 
  2975   - Some definitions of overloaded operators on sets can now be proved
  2976     using the definitions of the operators on => and bool.  Therefore,
  2977     the following theorems have been renamed:
  2978 
  2979       subset_def   -> subset_eq
  2980       psubset_def  -> psubset_eq
  2981       set_diff_def -> set_diff_eq
  2982       Compl_def    -> Compl_eq
  2983       Sup_set_def  -> Sup_set_eq
  2984       Inf_set_def  -> Inf_set_eq
  2985       sup_set_def  -> sup_set_eq
  2986       inf_set_def  -> inf_set_eq
  2987 
  2988   - Due to the incompleteness of the HO unification algorithm, some
  2989     rules such as subst may require manual instantiation, if some of
  2990     the unknowns in the rule is a set.
  2991 
  2992   - Higher order unification and forward proofs:
  2993     The proof pattern
  2994 
  2995       have "P (S::'a set)" <...>
  2996       then have "EX S. P S" ..
  2997 
  2998     no longer works (due to the incompleteness of the HO unification
  2999     algorithm) and must be replaced by the pattern
  3000 
  3001       have "EX S. P S"
  3002       proof
  3003         show "P S" <...>
  3004       qed
  3005 
  3006   - Calculational reasoning with subst (or similar rules):
  3007     The proof pattern
  3008 
  3009       have "P (S::'a set)" <...>
  3010       also have "S = T" <...>
  3011       finally have "P T" .
  3012 
  3013     no longer works (for similar reasons as the previous example) and
  3014     must be replaced by something like
  3015 
  3016       have "P (S::'a set)" <...>
  3017       moreover have "S = T" <...>
  3018       ultimately have "P T" by simp
  3019 
  3020   - Tactics or packages written in ML code:
  3021     Code performing pattern matching on types via
  3022 
  3023       Type ("set", [T]) => ...
  3024 
  3025     must be rewritten. Moreover, functions like strip_type or
  3026     binder_types no longer return the right value when applied to a
  3027     type of the form
  3028 
  3029       T1 => ... => Tn => U => bool
  3030 
  3031     rather than
  3032 
  3033       T1 => ... => Tn => U set
  3034 
  3035 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3036 Wellfounded_Relations to theory Wellfounded.
  3037 
  3038 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3039 
  3040 * Class finite no longer treats UNIV as class parameter.  Use class
  3041 enum from theory Library/Enum instead to achieve a similar effect.
  3042 INCOMPATIBILITY.
  3043 
  3044 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3045 and "Cons".  INCOMPATIBILITY.
  3046 
  3047 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3048 Potential INCOMPATIBILITY.
  3049 
  3050 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3051 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3052 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3053 
  3054 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3055 the same name in theory Orderings:
  3056 
  3057   less_trans
  3058   less_linear
  3059   le_imp_less_or_eq
  3060   le_less_trans
  3061   less_le_trans
  3062   less_not_sym
  3063   less_asym
  3064 
  3065 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3066 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3067 and different variable names.
  3068 
  3069 * Library/Option_ord.thy: Canonical order on option type.
  3070 
  3071 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3072 finite maps.
  3073 
  3074 * Library/Countable.thy: Type class for countable types.
  3075 
  3076 * Theory Int: The representation of numerals has changed.  The infix
  3077 operator BIT and the bit datatype with constructors B0 and B1 have
  3078 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3079 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3080 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3081 accordingly.
  3082 
  3083 * Theory Nat: definition of <= and < on natural numbers no longer
  3084 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3085 le_def and less_def have disappeared.  Consider lemmas not_less
  3086 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3087 
  3088 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3089 (whose purpose mainly is for various fold_set functionals) have been
  3090 abandoned in favor of the existing algebraic classes
  3091 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3092 lower_semilattice (resp. upper_semilattice) and linorder.
  3093 INCOMPATIBILITY.
  3094 
  3095 * Theory Transitive_Closure: induct and cases rules now declare proper
  3096 case_names ("base" and "step").  INCOMPATIBILITY.
  3097 
  3098 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3099 lattices.  The form set-specific version is available as
  3100 Inductive.lfp_ordinal_induct_set.
  3101 
  3102 * Renamed theorems "power.simps" to "power_int.simps".
  3103 INCOMPATIBILITY.
  3104 
  3105 * Class semiring_div provides basic abstract properties of semirings
  3106 with division and modulo operations.  Subsumes former class dvd_mod.
  3107 
  3108 * Merged theories IntDef, Numeral and IntArith into unified theory
  3109 Int.  INCOMPATIBILITY.
  3110 
  3111 * Theory Library/Code_Index: type "index" now represents natural
  3112 numbers rather than integers.  INCOMPATIBILITY.
  3113 
  3114 * New class "uminus" with operation "uminus" (split of from class
  3115 "minus" which now only has operation "minus", binary).
  3116 INCOMPATIBILITY.
  3117 
  3118 * Constants "card", "internal_split", "option_map" now with authentic
  3119 syntax.  INCOMPATIBILITY.
  3120 
  3121 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3122 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3123 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3124 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3125 Sup_set_def, le_def, less_def, option_map_def now with object
  3126 equality.  INCOMPATIBILITY.
  3127 
  3128 * Records. Removed K_record, and replaced it by pure lambda term
  3129 %x. c. The simplifier setup is now more robust against eta expansion.
  3130 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3131 
  3132 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3133 
  3134 * Library/ListVector: new theory of arithmetic vector operations.
  3135 
  3136 * Library/Order_Relation: new theory of various orderings as sets of
  3137 pairs.  Defines preorders, partial orders, linear orders and
  3138 well-orders on sets and on types.
  3139 
  3140 
  3141 *** ZF ***
  3142 
  3143 * Renamed some theories to allow to loading both ZF and HOL in the
  3144 same session:
  3145 
  3146   Datatype  -> Datatype_ZF
  3147   Inductive -> Inductive_ZF
  3148   Int       -> Int_ZF
  3149   IntDiv    -> IntDiv_ZF
  3150   Nat       -> Nat_ZF
  3151   List      -> List_ZF
  3152   Main      -> Main_ZF
  3153 
  3154 INCOMPATIBILITY: ZF theories that import individual theories below
  3155 Main might need to be adapted.  Regular theory Main is still
  3156 available, as trivial extension of Main_ZF.
  3157 
  3158 
  3159 *** ML ***
  3160 
  3161 * ML within Isar: antiquotation @{const name} or @{const
  3162 name(typargs)} produces statically-checked Const term.
  3163 
  3164 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3165 (of the same name).  Removed obsolete print command.
  3166 
  3167 * Removed obsolete "use_legacy_bindings" function.
  3168 
  3169 * The ``print mode'' is now a thread-local value derived from a global
  3170 template (the former print_mode reference), thus access becomes
  3171 non-critical.  The global print_mode reference is for session
  3172 management only; user-code should use print_mode_value,
  3173 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3174 
  3175 * Functions system/system_out provide a robust way to invoke external
  3176 shell commands, with propagation of interrupts (requires Poly/ML
  3177 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3178 
  3179 
  3180 *** System ***
  3181 
  3182 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3183 in accordance with Proof General 3.7, which prefers GNU emacs.
  3184 
  3185 * isatool tty runs Isabelle process with plain tty interaction;
  3186 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3187 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3188 
  3189 * isatool browser now works with Cygwin as well, using general
  3190 "javapath" function defined in Isabelle process environment.
  3191 
  3192 * YXML notation provides a simple and efficient alternative to
  3193 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3194 isatool yxml as described in the Isabelle system manual.
  3195 
  3196 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3197 provides general wrapper for managing an Isabelle process in a robust
  3198 fashion, with ``cooked'' output from stdin/stderr.
  3199 
  3200 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3201 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3202 
  3203 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3204 way of changing the user's settings is via
  3205 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3206 script.
  3207 
  3208 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3209 cores of the underlying machine, which is a good starting point for
  3210 optimal performance tuning.  The corresponding usedir option -M allows
  3211 "max" as an alias for "0".  WARNING: does not work on certain versions
  3212 of Mac OS (with Poly/ML 5.1).
  3213 
  3214 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3215 adverse effect of Isabelle flooding interactive front-ends (notably
  3216 ProofGeneral / XEmacs).
  3217 
  3218 
  3219 
  3220 New in Isabelle2007 (November 2007)
  3221 -----------------------------------
  3222 
  3223 *** General ***
  3224 
  3225 * More uniform information about legacy features, notably a
  3226 warning/error of "Legacy feature: ...", depending on the state of the
  3227 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3228 legacy features will disappear eventually.
  3229 
  3230 * Theory syntax: the header format ``theory A = B + C:'' has been
  3231 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3232 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3233 
  3234 * Theory syntax: the old non-Isar theory file format has been
  3235 discontinued altogether.  Note that ML proof scripts may still be used
  3236 with Isar theories; migration is usually quite simple with the ML
  3237 function use_legacy_bindings.  INCOMPATIBILITY.
  3238 
  3239 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3240 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3241 quotes.
  3242 
  3243 * Theory loader: be more serious about observing the static theory
  3244 header specifications (including optional directories), but not the
  3245 accidental file locations of previously successful loads.  The strict
  3246 update policy of former update_thy is now already performed by
  3247 use_thy, so the former has been removed; use_thys updates several
  3248 theories simultaneously, just as 'imports' within a theory header
  3249 specification, but without merging the results.  Potential
  3250 INCOMPATIBILITY: may need to refine theory headers and commands
  3251 ROOT.ML which depend on load order.
  3252 
  3253 * Theory loader: optional support for content-based file
  3254 identification, instead of the traditional scheme of full physical
  3255 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3256 (cf. the system manual).  The new scheme allows to work with
  3257 non-finished theories in persistent session images, such that source
  3258 files may be moved later on without requiring reloads.
  3259 
  3260 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3261 file (with the same base name as the theory) are considered a legacy
  3262 feature, which will disappear eventually. Even now, the theory loader
  3263 no longer maintains dependencies on such files.
  3264 
  3265 * Syntax: the scope for resolving ambiguities via type-inference is
  3266 now limited to individual terms, instead of whole simultaneous
  3267 specifications as before. This greatly reduces the complexity of the
  3268 syntax module and improves flexibility by separating parsing and
  3269 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3270 'fixes' etc.) are required in rare situations.
  3271 
  3272 * Syntax: constants introduced by new-style packages ('definition',
  3273 'abbreviation' etc.) are passed through the syntax module in
  3274 ``authentic mode''. This means that associated mixfix annotations
  3275 really stick to such constants, independently of potential name space
  3276 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3277 trees are represented slightly differently, may need to adapt syntax
  3278 translations accordingly. Use CONST marker in 'translations' and
  3279 @{const_syntax} antiquotation in 'parse_translation' etc.
  3280 
  3281 * Legacy goal package: reduced interface to the bare minimum required
  3282 to keep existing proof scripts running.  Most other user-level
  3283 functions are now part of the OldGoals structure, which is *not* open
  3284 by default (consider isatool expandshort before open OldGoals).
  3285 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3286 these tend to cause confusion about the actual goal (!) context being
  3287 used here, which is not necessarily the same as the_context().
  3288 
  3289 * Command 'find_theorems': supports "*" wild-card in "name:"
  3290 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3291 support a specific search form (see ProofGeneral/CHANGES).
  3292 
  3293 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3294 by default, which means that "prems" (and also "fixed variables") are
  3295 suppressed from proof state output.  Note that the ProofGeneral
  3296 settings mechanism allows to change and save options persistently, but
  3297 older versions of Isabelle will fail to start up if a negative prems
  3298 limit is imposed.
  3299 
  3300 * Local theory targets may be specified by non-nested blocks of
  3301 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3302 contain definitions, theorems etc., including any derived mechanism
  3303 that has been implemented on top of these primitives.  This concept
  3304 generalizes the existing ``theorem (in ...)'' towards more versatility
  3305 and scalability.
  3306 
  3307 * Proof General interface: proper undo of final 'end' command;
  3308 discontinued Isabelle/classic mode (ML proof scripts).
  3309 
  3310 
  3311 *** Document preparation ***
  3312 
  3313 * Added antiquotation @{theory name} which prints the given name,
  3314 after checking that it refers to a valid ancestor theory in the
  3315 current context.
  3316 
  3317 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3318 check the given source text as ML type/structure, printing verbatim.
  3319 
  3320 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3321 "c args == rhs" given in the current context.  (Any number of
  3322 arguments may be given on the LHS.)
  3323 
  3324 
  3325 *** Pure ***
  3326 
  3327 * The 'class' package offers a combination of axclass and locale to
  3328 achieve Haskell-like type classes in Isabelle.  Definitions and
  3329 theorems within a class context produce both relative results (with
  3330 implicit parameters according to the locale context), and polymorphic
  3331 constants with qualified polymorphism (according to the class
  3332 context).  Within the body context of a 'class' target, a separate
  3333 syntax layer ("user space type system") takes care of converting
  3334 between global polymorphic consts and internal locale representation.
  3335 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3336 "isatool doc classes" provides a tutorial.
  3337 
  3338 * Generic code generator framework allows to generate executable
  3339 code for ML and Haskell (including Isabelle classes).  A short usage
  3340 sketch:
  3341 
  3342     internal compilation:
  3343         export_code <list of constants (term syntax)> in SML
  3344     writing SML code to a file:
  3345         export_code <list of constants (term syntax)> in SML <filename>
  3346     writing OCaml code to a file:
  3347         export_code <list of constants (term syntax)> in OCaml <filename>
  3348     writing Haskell code to a bunch of files:
  3349         export_code <list of constants (term syntax)> in Haskell <filename>
  3350 
  3351     evaluating closed propositions to True/False using code generation:
  3352         method ``eval''
  3353 
  3354 Reasonable default setup of framework in HOL.
  3355 
  3356 Theorem attributs for selecting and transforming function equations theorems:
  3357 
  3358     [code fun]:        select a theorem as function equation for a specific constant
  3359     [code fun del]:    deselect a theorem as function equation for a specific constant
  3360     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3361     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3362 
  3363 User-defined serializations (target in {SML, OCaml, Haskell}):
  3364 
  3365     code_const <and-list of constants (term syntax)>
  3366       {(target) <and-list of const target syntax>}+
  3367 
  3368     code_type <and-list of type constructors>
  3369       {(target) <and-list of type target syntax>}+
  3370 
  3371     code_instance <and-list of instances>
  3372       {(target)}+
  3373         where instance ::= <type constructor> :: <class>
  3374 
  3375     code_class <and_list of classes>
  3376       {(target) <and-list of class target syntax>}+
  3377         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3378 
  3379 code_instance and code_class only are effective to target Haskell.
  3380 
  3381 For example usage see src/HOL/ex/Codegenerator.thy and
  3382 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3383 generation from Isabelle/HOL theories is available via "isatool doc
  3384 codegen".
  3385 
  3386 * Code generator: consts in 'consts_code' Isar commands are now
  3387 referred to by usual term syntax (including optional type
  3388 annotations).
  3389 
  3390 * Command 'no_translations' removes translation rules from theory
  3391 syntax.
  3392 
  3393 * Overloaded definitions are now actually checked for acyclic
  3394 dependencies.  The overloading scheme is slightly more general than
  3395 that of Haskell98, although Isabelle does not demand an exact
  3396 correspondence to type class and instance declarations.
  3397 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3398 exotic versions of overloading -- at the discretion of the user!
  3399 
  3400 Polymorphic constants are represented via type arguments, i.e. the
  3401 instantiation that matches an instance against the most general
  3402 declaration given in the signature.  For example, with the declaration
  3403 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3404 as c(nat).  Overloading is essentially simultaneous structural
  3405 recursion over such type arguments.  Incomplete specification patterns
  3406 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3407 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3408 Command 'print_theory' outputs the normalized system of recursive
  3409 equations, see section "definitions".
  3410 
  3411 * Configuration options are maintained within the theory or proof
  3412 context (with name and type bool/int/string), providing a very simple
  3413 interface to a poor-man's version of general context data.  Tools may
  3414 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3415 these values using Config.get etc.  Users may change options via an
  3416 associated attribute of the same name.  This form of context
  3417 declaration works particularly well with commands 'declare' or
  3418 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3419 very easy to avoid global references, which would not observe Isar
  3420 toplevel undo/redo and fail to work with multithreading.
  3421 
  3422 Various global ML references of Pure and HOL have been turned into
  3423 configuration options:
  3424 
  3425   Unify.search_bound		unify_search_bound
  3426   Unify.trace_bound		unify_trace_bound
  3427   Unify.trace_simp		unify_trace_simp
  3428   Unify.trace_types		unify_trace_types
  3429   Simplifier.simp_depth_limit	simp_depth_limit
  3430   Blast.depth_limit		blast_depth_limit
  3431   DatatypeProp.dtK		datatype_distinctness_limit
  3432   fast_arith_neq_limit  	fast_arith_neq_limit
  3433   fast_arith_split_limit	fast_arith_split_limit
  3434 
  3435 * Named collections of theorems may be easily installed as context
  3436 data using the functor NamedThmsFun (see also
  3437 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3438 attributes; there is also a toplevel print command.  This facility is
  3439 just a common case of general context data, which is the preferred way
  3440 for anything more complex than just a list of facts in canonical
  3441 order.
  3442 
  3443 * Isar: command 'declaration' augments a local theory by generic
  3444 declaration functions written in ML.  This enables arbitrary content
  3445 being added to the context, depending on a morphism that tells the
  3446 difference of the original declaration context wrt. the application
  3447 context encountered later on.
  3448 
  3449 * Isar: proper interfaces for simplification procedures.  Command
  3450 'simproc_setup' declares named simprocs (with match patterns, and body
  3451 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3452 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3453 
  3454 * Isar: an extra pair of brackets around attribute declarations
  3455 abbreviates a theorem reference involving an internal dummy fact,
  3456 which will be ignored later --- only the effect of the attribute on
  3457 the background context will persist.  This form of in-place
  3458 declarations is particularly useful with commands like 'declare' and
  3459 'using', for example ``have A using [[simproc a]] by simp''.
  3460 
  3461 * Isar: method "assumption" (and implicit closing of subproofs) now
  3462 takes simple non-atomic goal assumptions into account: after applying
  3463 an assumption as a rule the resulting subgoals are solved by atomic
  3464 assumption steps.  This is particularly useful to finish 'obtain'
  3465 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3466 without referring to the original premise "!!x. P x ==> thesis" in the
  3467 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3468 more permissive.
  3469 
  3470 * Isar: implicit use of prems from the Isar proof context is
  3471 considered a legacy feature.  Common applications like ``have A .''
  3472 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3473 referencing facts explicitly here improves readability and
  3474 maintainability of proof texts.
  3475 
  3476 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3477 the obtained context from the course of reasoning!  For example:
  3478 
  3479   assume "EX x y. A x & B y"   -- "any previous fact"
  3480   then guess x and y by clarify
  3481 
  3482 This technique is potentially adventurous, depending on the facts and
  3483 proof tools being involved here.
  3484 
  3485 * Isar: known facts from the proof context may be specified as literal
  3486 propositions, using ASCII back-quote syntax.  This works wherever
  3487 named facts used to be allowed so far, in proof commands, proof
  3488 methods, attributes etc.  Literal facts are retrieved from the context
  3489 according to unification of type and term parameters.  For example,
  3490 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3491 theorems in the current context, then these are valid literal facts:
  3492 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3493 
  3494 There is also a proof method "fact" which does the same composition
  3495 for explicit goal states, e.g. the following proof texts coincide with
  3496 certain special cases of literal facts:
  3497 
  3498   have "A" by fact                 ==  note `A`
  3499   have "A ==> B" by fact           ==  note `A ==> B`
  3500   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3501   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3502 
  3503 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3504 outer syntax.  Thus symbolic identifiers may be used without
  3505 additional white space in declarations like this: ``assume *: A''.
  3506 
  3507 * Isar: 'print_facts' prints all local facts of the current context,
  3508 both named and unnamed ones.
  3509 
  3510 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3511 
  3512   def x == "t" and y == "u"
  3513 
  3514 * Isar: added command 'unfolding', which is structurally similar to
  3515 'using', but affects both the goal state and facts by unfolding given
  3516 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3517 'unfolded' attribute may be replaced by first-class proof text.
  3518 
  3519 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3520 and command 'unfolding' now all support object-level equalities
  3521 (potentially conditional).  The underlying notion of rewrite rule is
  3522 analogous to the 'rule_format' attribute, but *not* that of the
  3523 Simplifier (which is usually more generous).
  3524 
  3525 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3526 premises of a theorem by n. Useful in conjunction with drule.
  3527 
  3528 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3529 method expression within a sandbox consisting of the first N
  3530 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3531 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3532 simplifies all new goals that emerge from applying rule foo to the
  3533 originally first one.
  3534 
  3535 * Isar: schematic goals are no longer restricted to higher-order
  3536 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3537 expected.
  3538 
  3539 * Isar: the conclusion of a long theorem statement is now either
  3540 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3541 (essentially a disjunction of cases with local parameters and
  3542 assumptions).  The latter allows to express general elimination rules
  3543 adequately; in this notation common elimination rules look like this:
  3544 
  3545   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3546     assumes "EX x. P x"
  3547     obtains x where "P x"
  3548 
  3549   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3550     assumes "A & B"
  3551     obtains A and B
  3552 
  3553   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3554     assumes "A | B"
  3555     obtains
  3556       A
  3557     | B
  3558 
  3559 The subsequent classical rules even refer to the formal "thesis"
  3560 explicitly:
  3561 
  3562   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3563     obtains "~ thesis"
  3564 
  3565   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3566     obtains "thesis ==> something"
  3567 
  3568 The actual proof of an 'obtains' statement is analogous to that of the
  3569 Isar proof element 'obtain', only that there may be several cases.
  3570 Optional case names may be specified in parentheses; these will be
  3571 available both in the present proof and as annotations in the
  3572 resulting rule, for later use with the 'cases' method (cf. attribute
  3573 case_names).
  3574 
  3575 * Isar: the assumptions of a long theorem statement are available as
  3576 "assms" fact in the proof context.  This is more appropriate than the
  3577 (historical) "prems", which refers to all assumptions of the current
  3578 context, including those from the target locale, proof body etc.
  3579 
  3580 * Isar: 'print_statement' prints theorems from the current theory or
  3581 proof context in long statement form, according to the syntax of a
  3582 top-level lemma.
  3583 
  3584 * Isar: 'obtain' takes an optional case name for the local context
  3585 introduction rule (default "that").
  3586 
  3587 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3588 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3589 to occur.
  3590 
  3591 * Pure: syntax "CONST name" produces a fully internalized constant
  3592 according to the current context.  This is particularly useful for
  3593 syntax translations that should refer to internal constant
  3594 representations independently of name spaces.
  3595 
  3596 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3597 instead of "FOO ". This allows multiple binder declarations to coexist
  3598 in the same context.  INCOMPATIBILITY.
  3599 
  3600 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3601 primitive that also works in a locale context (both for constants and
  3602 fixed variables). Type declaration and internal syntactic representation
  3603 of given constants retrieved from the context. Likewise, the
  3604 'no_notation' command allows to remove given syntax annotations from the
  3605 current context.
  3606 
  3607 * Isar/locales: new derived specification elements 'axiomatization',
  3608 'definition', 'abbreviation', which support type-inference, admit
  3609 object-level specifications (equality, equivalence).  See also the
  3610 isar-ref manual.  Examples:
  3611 
  3612   axiomatization
  3613     eq  (infix "===" 50) where
  3614     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3615 
  3616   definition "f x y = x + y + 1"
  3617   definition g where "g x = f x x"
  3618 
  3619   abbreviation
  3620     neq  (infix "=!=" 50) where
  3621     "x =!= y == ~ (x === y)"
  3622 
  3623 These specifications may be also used in a locale context.  Then the
  3624 constants being introduced depend on certain fixed parameters, and the
  3625 constant name is qualified by the locale base name.  An internal
  3626 abbreviation takes care for convenient input and output, making the
  3627 parameters implicit and using the original short name.  See also
  3628 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3629 entities from a monomorphic theory.
  3630 
  3631 Presently, abbreviations are only available 'in' a target locale, but
  3632 not inherited by general import expressions.  Also note that
  3633 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3634 'translations' in common applications.  The "no_abbrevs" print mode
  3635 prevents folding of abbreviations in term output.
  3636 
  3637 Concrete syntax is attached to specified constants in internal form,
  3638 independently of name spaces.  The parse tree representation is
  3639 slightly different -- use 'notation' instead of raw 'syntax', and
  3640 'translations' with explicit "CONST" markup to accommodate this.
  3641 
  3642 * Pure/Isar: unified syntax for new-style specification mechanisms
  3643 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3644 full type inference and dummy patterns ("_").  For example:
  3645 
  3646   definition "K x _ = x"
  3647 
  3648   inductive conj for A B
  3649   where "A ==> B ==> conj A B"
  3650 
  3651 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3652 the current context.  Print mode "no_abbrevs" prevents inversion of
  3653 abbreviations on output.
  3654 
  3655 * Isar/locales: improved parameter handling: use of locales "var" and
  3656 "struct" no longer necessary; - parameter renamings are no longer
  3657 required to be injective.  For example, this allows to define
  3658 endomorphisms as locale endom = homom mult mult h.
  3659 
  3660 * Isar/locales: changed the way locales with predicates are defined.
  3661 Instead of accumulating the specification, the imported expression is
  3662 now an interpretation.  INCOMPATIBILITY: different normal form of
  3663 locale expressions.  In particular, in interpretations of locales with
  3664 predicates, goals repesenting already interpreted fragments are not
  3665 removed automatically.  Use methods `intro_locales' and
  3666 `unfold_locales'; see below.
  3667 
  3668 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3669 provide backward reasoning on locales predicates.  The methods are
  3670 aware of interpretations and discharge corresponding goals.
  3671 `intro_locales' is less aggressive then `unfold_locales' and does not
  3672 unfold predicates to assumptions.
  3673 
  3674 * Isar/locales: the order in which locale fragments are accumulated
  3675 has changed.  This enables to override declarations from fragments due
  3676 to interpretations -- for example, unwanted simp rules.
  3677 
  3678 * Isar/locales: interpretation in theories and proof contexts has been
  3679 extended.  One may now specify (and prove) equations, which are
  3680 unfolded in interpreted theorems.  This is useful for replacing
  3681 defined concepts (constants depending on locale parameters) by
  3682 concepts already existing in the target context.  Example:
  3683 
  3684   interpretation partial_order ["op <= :: [int, int] => bool"]
  3685     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3686 
  3687 Typically, the constant `partial_order.less' is created by a
  3688 definition specification element in the context of locale
  3689 partial_order.
  3690 
  3691 * Method "induct": improved internal context management to support
  3692 local fixes and defines on-the-fly. Thus explicit meta-level
  3693 connectives !!  and ==> are rarely required anymore in inductive goals
  3694 (using object-logic connectives for this purpose has been long
  3695 obsolete anyway). Common proof patterns are explained in
  3696 src/HOL/Induct/Common_Patterns.thy, see also
  3697 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3698 examples.
  3699 
  3700 * Method "induct": improved handling of simultaneous goals. Instead of
  3701 introducing object-level conjunction, the statement is now split into
  3702 several conclusions, while the corresponding symbolic cases are nested
  3703 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3704 see src/HOL/Induct/Common_Patterns.thy, for example.
  3705 
  3706 * Method "induct": mutual induction rules are now specified as a list
  3707 of rule sharing the same induction cases. HOL packages usually provide
  3708 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3709 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3710 mutual induction rules differently, i.e. like this:
  3711 
  3712   (induct rule: foo_bar.inducts)
  3713   (induct set: foo bar)
  3714   (induct pred: foo bar)
  3715   (induct type: foo bar)
  3716 
  3717 The ML function ProjectRule.projections turns old-style rules into the
  3718 new format.
  3719 
  3720 * Method "coinduct": dual of induction, see
  3721 src/HOL/Library/Coinductive_List.thy for various examples.
  3722 
  3723 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3724 considered a legacy feature.
  3725 
  3726 * Attribute "symmetric" produces result with standardized schematic
  3727 variables (index 0).  Potential INCOMPATIBILITY.
  3728 
  3729 * Simplifier: by default the simplifier trace only shows top level
  3730 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3731 default. Thus there is less danger of being flooded by the trace. The
  3732 trace indicates where parts have been suppressed.
  3733   
  3734 * Provers/classical: removed obsolete classical version of elim_format
  3735 attribute; classical elim/dest rules are now treated uniformly when
  3736 manipulating the claset.
  3737 
  3738 * Provers/classical: stricter checks to ensure that supplied intro,
  3739 dest and elim rules are well-formed; dest and elim rules must have at
  3740 least one premise.
  3741 
  3742 * Provers/classical: attributes dest/elim/intro take an optional
  3743 weight argument for the rule (just as the Pure versions).  Weights are
  3744 ignored by automated tools, but determine the search order of single
  3745 rule steps.
  3746 
  3747 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3748 where the body does not mention the bound variable.  Note that dummy
  3749 patterns implicitly depend on their context of bounds, which makes
  3750 "{_. _}" match any set comprehension as expected.  Potential
  3751 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3752 constant "_idtdummy" in the binding position.
  3753 
  3754 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3755 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3756 for example "A -> B" => "Pi A (%_. B)".
  3757 
  3758 * Pure: 'class_deps' command visualizes the subclass relation, using
  3759 the graph browser tool.
  3760 
  3761 * Pure: 'print_theory' now suppresses certain internal declarations by
  3762 default; use '!' option for full details.
  3763 
  3764 
  3765 *** HOL ***
  3766 
  3767 * Method "metis" proves goals by applying the Metis general-purpose
  3768 resolution prover (see also http://gilith.com/software/metis/).
  3769 Examples are in the directory MetisExamples.  WARNING: the
  3770 Isabelle/HOL-Metis integration does not yet work properly with
  3771 multi-threading.
  3772   
  3773 * Command 'sledgehammer' invokes external automatic theorem provers as
  3774 background processes.  It generates calls to the "metis" method if
  3775 successful. These can be pasted into the proof.  Users do not have to
  3776 wait for the automatic provers to return.  WARNING: does not really
  3777 work with multi-threading.
  3778 
  3779 * New "auto_quickcheck" feature tests outermost goal statements for
  3780 potential counter-examples.  Controlled by ML references
  3781 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3782 5000 milliseconds).  Fails silently if statements is outside of
  3783 executable fragment, or any other codgenerator problem occurs.
  3784 
  3785 * New constant "undefined" with axiom "undefined x = undefined".
  3786 
  3787 * Added class "HOL.eq", allowing for code generation with polymorphic
  3788 equality.
  3789 
  3790 * Some renaming of class constants due to canonical name prefixing in
  3791 the new 'class' package:
  3792 
  3793     HOL.abs ~> HOL.abs_class.abs
  3794     HOL.divide ~> HOL.divide_class.divide
  3795     0 ~> HOL.zero_class.zero
  3796     1 ~> HOL.one_class.one
  3797     op + ~> HOL.plus_class.plus
  3798     op - ~> HOL.minus_class.minus
  3799     uminus ~> HOL.minus_class.uminus
  3800     op * ~> HOL.times_class.times
  3801     op < ~> HOL.ord_class.less
  3802     op <= > HOL.ord_class.less_eq
  3803     Nat.power ~> Power.power_class.power
  3804     Nat.size ~> Nat.size_class.size
  3805     Numeral.number_of ~> Numeral.number_class.number_of
  3806     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3807     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3808     Orderings.min ~> Orderings.ord_class.min
  3809     Orderings.max ~> Orderings.ord_class.max
  3810     Divides.op div ~> Divides.div_class.div
  3811     Divides.op mod ~> Divides.div_class.mod
  3812     Divides.op dvd ~> Divides.div_class.dvd
  3813 
  3814 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3815 
  3816 a) User-defined constants using any of the names "plus", "minus",
  3817 "times", "less" or "less_eq". The standard syntax translations for
  3818 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3819 names.
  3820 
  3821 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3822 INCOMPATIBILITY: use more specific names.
  3823 
  3824 c) Permutative equations (e.g. "a + b = b + a")
  3825 Since the change of names also changes the order of terms, permutative
  3826 rewrite rules may get applied in a different order. Experience shows
  3827 that this is rarely the case (only two adaptions in the whole Isabelle
  3828 distribution).  INCOMPATIBILITY: rewrite proofs
  3829 
  3830 d) ML code directly refering to constant names
  3831 This in general only affects hand-written proof tactics, simprocs and
  3832 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3833 Consider using @{const_name} antiquotation.
  3834 
  3835 * New class "default" with associated constant "default".
  3836 
  3837 * Function "sgn" is now overloaded and available on int, real, complex
  3838 (and other numeric types), using class "sgn".  Two possible defs of
  3839 sgn are given as equational assumptions in the classes sgn_if and
  3840 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3841 INCOMPATIBILITY.
  3842 
  3843 * Locale "partial_order" now unified with class "order" (cf. theory
  3844 Orderings), added parameter "less".  INCOMPATIBILITY.
  3845 
  3846 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3847 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3848 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3849 
  3850 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3851 changed order of proof goals in instance proofs.
  3852 
  3853 * The transitivity reasoner for partial and linear orders is set up
  3854 for classes "order" and "linorder".  Instances of the reasoner are available
  3855 in all contexts importing or interpreting the corresponding locales.
  3856 Method "order" invokes the reasoner separately; the reasoner
  3857 is also integrated with the Simplifier as a solver.  Diagnostic
  3858 command 'print_orders' shows the available instances of the reasoner
  3859 in the current context.
  3860 
  3861 * Localized monotonicity predicate in theory "Orderings"; integrated
  3862 lemmas max_of_mono and min_of_mono with this predicate.
  3863 INCOMPATIBILITY.
  3864 
  3865 * Formulation of theorem "dense" changed slightly due to integration
  3866 with new class dense_linear_order.
  3867 
  3868 * Uniform lattice theory development in HOL.
  3869 
  3870     constants "meet" and "join" now named "inf" and "sup"
  3871     constant "Meet" now named "Inf"
  3872 
  3873     classes "meet_semilorder" and "join_semilorder" now named
  3874       "lower_semilattice" and "upper_semilattice"
  3875     class "lorder" now named "lattice"
  3876     class "comp_lat" now named "complete_lattice"
  3877 
  3878     Instantiation of lattice classes allows explicit definitions
  3879     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3880 
  3881   INCOMPATIBILITY.  Theorem renames:
  3882 
  3883     meet_left_le            ~> inf_le1
  3884     meet_right_le           ~> inf_le2
  3885     join_left_le            ~> sup_ge1
  3886     join_right_le           ~> sup_ge2
  3887     meet_join_le            ~> inf_sup_ord
  3888     le_meetI                ~> le_infI
  3889     join_leI                ~> le_supI
  3890     le_meet                 ~> le_inf_iff
  3891     le_join                 ~> ge_sup_conv
  3892     meet_idempotent         ~> inf_idem
  3893     join_idempotent         ~> sup_idem
  3894     meet_comm               ~> inf_commute
  3895     join_comm               ~> sup_commute
  3896     meet_leI1               ~> le_infI1
  3897     meet_leI2               ~> le_infI2
  3898     le_joinI1               ~> le_supI1
  3899     le_joinI2               ~> le_supI2
  3900     meet_assoc              ~> inf_assoc
  3901     join_assoc              ~> sup_assoc
  3902     meet_left_comm          ~> inf_left_commute
  3903     meet_left_idempotent    ~> inf_left_idem
  3904     join_left_comm          ~> sup_left_commute
  3905     join_left_idempotent    ~> sup_left_idem
  3906     meet_aci                ~> inf_aci
  3907     join_aci                ~> sup_aci
  3908     le_def_meet             ~> le_iff_inf
  3909     le_def_join             ~> le_iff_sup
  3910     join_absorp2            ~> sup_absorb2
  3911     join_absorp1            ~> sup_absorb1
  3912     meet_absorp1            ~> inf_absorb1
  3913     meet_absorp2            ~> inf_absorb2
  3914     meet_join_absorp        ~> inf_sup_absorb
  3915     join_meet_absorp        ~> sup_inf_absorb
  3916     distrib_join_le         ~> distrib_sup_le
  3917     distrib_meet_le         ~> distrib_inf_le
  3918 
  3919     add_meet_distrib_left   ~> add_inf_distrib_left
  3920     add_join_distrib_left   ~> add_sup_distrib_left
  3921     is_join_neg_meet        ~> is_join_neg_inf
  3922     is_meet_neg_join        ~> is_meet_neg_sup
  3923     add_meet_distrib_right  ~> add_inf_distrib_right
  3924     add_join_distrib_right  ~> add_sup_distrib_right
  3925     add_meet_join_distribs  ~> add_sup_inf_distribs
  3926     join_eq_neg_meet        ~> sup_eq_neg_inf
  3927     meet_eq_neg_join        ~> inf_eq_neg_sup
  3928     add_eq_meet_join        ~> add_eq_inf_sup
  3929     meet_0_imp_0            ~> inf_0_imp_0
  3930     join_0_imp_0            ~> sup_0_imp_0
  3931     meet_0_eq_0             ~> inf_0_eq_0
  3932     join_0_eq_0             ~> sup_0_eq_0
  3933     neg_meet_eq_join        ~> neg_inf_eq_sup
  3934     neg_join_eq_meet        ~> neg_sup_eq_inf
  3935     join_eq_if              ~> sup_eq_if
  3936 
  3937     mono_meet               ~> mono_inf
  3938     mono_join               ~> mono_sup
  3939     meet_bool_eq            ~> inf_bool_eq
  3940     join_bool_eq            ~> sup_bool_eq
  3941     meet_fun_eq             ~> inf_fun_eq
  3942     join_fun_eq             ~> sup_fun_eq
  3943     meet_set_eq             ~> inf_set_eq
  3944     join_set_eq             ~> sup_set_eq
  3945     meet1_iff               ~> inf1_iff
  3946     meet2_iff               ~> inf2_iff
  3947     meet1I                  ~> inf1I
  3948     meet2I                  ~> inf2I
  3949     meet1D1                 ~> inf1D1
  3950     meet2D1                 ~> inf2D1
  3951     meet1D2                 ~> inf1D2
  3952     meet2D2                 ~> inf2D2
  3953     meet1E                  ~> inf1E
  3954     meet2E                  ~> inf2E
  3955     join1_iff               ~> sup1_iff
  3956     join2_iff               ~> sup2_iff
  3957     join1I1                 ~> sup1I1
  3958     join2I1                 ~> sup2I1
  3959     join1I1                 ~> sup1I1
  3960     join2I2                 ~> sup1I2
  3961     join1CI                 ~> sup1CI
  3962     join2CI                 ~> sup2CI
  3963     join1E                  ~> sup1E
  3964     join2E                  ~> sup2E
  3965 
  3966     is_meet_Meet            ~> is_meet_Inf
  3967     Meet_bool_def           ~> Inf_bool_def
  3968     Meet_fun_def            ~> Inf_fun_def
  3969     Meet_greatest           ~> Inf_greatest
  3970     Meet_lower              ~> Inf_lower
  3971     Meet_set_def            ~> Inf_set_def
  3972 
  3973     Sup_def                 ~> Sup_Inf
  3974     Sup_bool_eq             ~> Sup_bool_def
  3975     Sup_fun_eq              ~> Sup_fun_def
  3976     Sup_set_eq              ~> Sup_set_def
  3977 
  3978     listsp_meetI            ~> listsp_infI
  3979     listsp_meet_eq          ~> listsp_inf_eq
  3980 
  3981     meet_min                ~> inf_min
  3982     join_max                ~> sup_max
  3983 
  3984 * Added syntactic class "size"; overloaded constant "size" now has
  3985 type "'a::size ==> bool"
  3986 
  3987 * Internal reorganisation of `size' of datatypes: size theorems
  3988 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3989 simplification rules by default!); theorems "prod.size" now named
  3990 "*.size".
  3991 
  3992 * Class "div" now inherits from class "times" rather than "type".
  3993 INCOMPATIBILITY.
  3994 
  3995 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3996 Linorder etc.  have disappeared; operations defined in terms of
  3997 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3998 
  3999 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4000 
  4001 * HOL-Word: New extensive library and type for generic, fixed size
  4002 machine words, with arithemtic, bit-wise, shifting and rotating
  4003 operations, reflection into int, nat, and bool lists, automation for
  4004 linear arithmetic (by automatic reflection into nat or int), including
  4005 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4006 arithmetic type classes, supporting automatic simplification of
  4007 numerals on all operations.
  4008 
  4009 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4010 
  4011 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4012 
  4013 * Code generator library theories:
  4014   - Code_Integer represents HOL integers by big integer literals in target
  4015     languages.
  4016   - Code_Char represents HOL characters by character literals in target
  4017     languages.
  4018   - Code_Char_chr like Code_Char, but also offers treatment of character
  4019     codes; includes Code_Integer.
  4020   - Executable_Set allows to generate code for finite sets using lists.
  4021   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4022     denominator).
  4023   - Executable_Real implements a subset of real numbers, namly those
  4024     representable by rational numbers.
  4025   - Efficient_Nat implements natural numbers by integers, which in general will
  4026     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4027     includes Code_Integer.
  4028   - Code_Index provides an additional datatype index which is mapped to
  4029     target-language built-in integers.
  4030   - Code_Message provides an additional datatype message_string which is isomorphic to
  4031     strings; messages are mapped to target-language strings.
  4032 
  4033 * New package for inductive predicates
  4034 
  4035   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4036 
  4037     inductive
  4038       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       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4042     | ...
  4043 
  4044   with full support for type-inference, rather than
  4045 
  4046     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4047 
  4048     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4049     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4050 
  4051     inductive "s z_1 ... z_m"
  4052     intros
  4053       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4054       ...
  4055 
  4056   For backward compatibility, there is a wrapper allowing inductive
  4057   sets to be defined with the new package via
  4058 
  4059     inductive_set
  4060       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4061       for z_1 :: U_1 and ... and z_n :: U_m
  4062     where
  4063       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4064     | ...
  4065 
  4066   or
  4067 
  4068     inductive_set
  4069       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4070       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4071       for z_1 :: U_1 and ... and z_n :: U_m
  4072     where
  4073       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4074     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4075     | ...
  4076 
  4077   if the additional syntax "p ..." is required.
  4078 
  4079   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4080   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4081 
  4082   INCOMPATIBILITIES:
  4083 
  4084   - Since declaration and definition of inductive sets or predicates
  4085     is no longer separated, abbreviations involving the newly
  4086     introduced sets or predicates must be specified together with the
  4087     introduction rules after the 'where' keyword (see above), rather
  4088     than before the actual inductive definition.
  4089 
  4090   - The variables in induction and elimination rules are now
  4091     quantified in the order of their occurrence in the introduction
  4092     rules, rather than in alphabetical order. Since this may break
  4093     some proofs, these proofs either have to be repaired, e.g. by
  4094     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4095     statements of the form
  4096 
  4097       case (rule_i a_i_1 ... a_i_{k_i})
  4098 
  4099     or the old order of quantification has to be restored by explicitly adding
  4100     meta-level quantifiers in the introduction rules, i.e.
  4101 
  4102       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4103 
  4104   - The format of the elimination rules is now
  4105 
  4106       p z_1 ... z_m x_1 ... x_n ==>
  4107         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4108         ==> ... ==> P
  4109 
  4110     for predicates and
  4111 
  4112       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4113         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4114         ==> ... ==> P
  4115 
  4116     for sets rather than
  4117 
  4118       x : s z_1 ... z_m ==>
  4119         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4120         ==> ... ==> P
  4121 
  4122     This may require terms in goals to be expanded to n-tuples
  4123     (e.g. using case_tac or simplification with the split_paired_all
  4124     rule) before the above elimination rule is applicable.
  4125 
  4126   - The elimination or case analysis rules for (mutually) inductive
  4127     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4128     list of rules "p_1_..._p_k.elims" is no longer available.
  4129 
  4130 * New package "function"/"fun" for general recursive functions,
  4131 supporting mutual and nested recursion, definitions in local contexts,
  4132 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4133 for small examples, and the separate tutorial on the function
  4134 package. The old recdef "package" is still available as before, but
  4135 users are encouraged to use the new package.
  4136 
  4137 * Method "lexicographic_order" automatically synthesizes termination
  4138 relations as lexicographic combinations of size measures. 
  4139 
  4140 * Case-expressions allow arbitrary constructor-patterns (including
  4141 "_") and take their order into account, like in functional
  4142 programming.  Internally, this is translated into nested
  4143 case-expressions; missing cases are added and mapped to the predefined
  4144 constant "undefined". In complicated cases printing may no longer show
  4145 the original input but the internal form. Lambda-abstractions allow
  4146 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4147 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4148 variable.
  4149 
  4150 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4151 is an abbreviation for "of_nat :: nat => int". The simplification
  4152 rules for "of_nat" have been changed to work like "int" did
  4153 previously.  Potential INCOMPATIBILITY:
  4154   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4155   - of_nat_diff and of_nat_mult are no longer default simp rules
  4156 
  4157 * Method "algebra" solves polynomial equations over (semi)rings using
  4158 Groebner bases. The (semi)ring structure is defined by locales and the
  4159 tool setup depends on that generic context. Installing the method for
  4160 a specific type involves instantiating the locale and possibly adding
  4161 declarations for computation on the coefficients.  The method is
  4162 already instantiated for natural numbers and for the axiomatic class
  4163 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4164 CALCULEMUS 2007 for the general principles underlying this
  4165 architecture of context-aware proof-tools.
  4166 
  4167 * Method "ferrack" implements quantifier elimination over
  4168 special-purpose dense linear orders using locales (analogous to
  4169 "algebra"). The method is already installed for class
  4170 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4171 rat, etc.
  4172 
  4173 * Former constant "List.op @" now named "List.append".  Use ML
  4174 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4175 circumvent possible incompatibilities when working on ML level.
  4176 
  4177 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4178 
  4179 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4180 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4181 
  4182 * New syntax for Haskell-like list comprehension (input only), eg.
  4183 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4184 
  4185 * The special syntax for function "filter" has changed from [x :
  4186 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4187 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4188 
  4189 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4190 defined on nat only, as an abbreviation for [a..<Suc b]
  4191 INCOMPATIBILITY.
  4192 
  4193 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4194 
  4195 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4196 
  4197 * New lemma collection field_simps (an extension of ring_simps) for
  4198 manipulating (in)equations involving division. Multiplies with all
  4199 denominators that can be proved to be non-zero (in equations) or
  4200 positive/negative (in inequations).
  4201 
  4202 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4203 have been improved and renamed to ring_simps, group_simps and
  4204 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4205 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4206 
  4207 * Theory Library/Commutative_Ring: switched from recdef to function
  4208 package; constants add, mul, pow now curried.  Infix syntax for
  4209 algebraic operations.
  4210 
  4211 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4212 INCOMPATIBILITY.
  4213 
  4214 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4215 INCOMPATIBILITY.
  4216 
  4217 * HOL/records: generalised field-update to take a function on the
  4218 field rather than the new value: r(|A := x|) is translated to A_update
  4219 (K x) r The K-combinator that is internally used is called K_record.
  4220 INCOMPATIBILITY: Usage of the plain update functions has to be
  4221 adapted.
  4222  
  4223 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4224 * x = 0, which are required for a semiring.  Richer structures do not
  4225 inherit from semiring_0 anymore, because this property is a theorem
  4226 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4227 there is more to prove, but this is mostly trivial.
  4228 
  4229 * Class "recpower" is generalized to arbitrary monoids, not just
  4230 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4231 commutativity or semiring properties additionally.
  4232 
  4233 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4234 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4235 better use 'abbreviation'.
  4236 
  4237 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4238 
  4239 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4240 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4241 significant changes for setting up numeral syntax for types:
  4242   - New constants Numeral.pred and Numeral.succ instead
  4243       of former Numeral.bin_pred and Numeral.bin_succ.
  4244   - Use integer operations instead of bin_add, bin_mult and so on.
  4245   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4246   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4247 
  4248 See src/HOL/Integ/IntArith.thy for an example setup.
  4249 
  4250 * Command 'normal_form' computes the normal form of a term that may
  4251 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4252 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4253 heavy-duty computations because the functions are compiled to ML
  4254 first.  Correspondingly, a method "normalization" is provided.  See
  4255 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4256 
  4257 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4258 25 like -->); output depends on the "iff" print_mode, the default is
  4259 "A = B" (with priority 50).
  4260 
  4261 * Relations less (<) and less_eq (<=) are also available on type bool.
  4262 Modified syntax to disallow nesting without explicit parentheses,
  4263 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4264 INCOMPATIBILITY.
  4265 
  4266 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4267 
  4268 * Relation composition operator "op O" now has precedence 75 and binds
  4269 stronger than union and intersection. INCOMPATIBILITY.
  4270 
  4271 * The old set interval syntax "{m..n(}" (and relatives) has been
  4272 removed.  Use "{m..<n}" (and relatives) instead.
  4273 
  4274 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4275 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4276 ``declare [[simproc del: neq]]''.
  4277 
  4278 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4279 True/False.
  4280 
  4281 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4282 
  4283 * Theorem setsum_mult renamed to setsum_right_distrib.
  4284 
  4285 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4286 ``rule'' method.
  4287 
  4288 * Reimplemented methods "sat" and "satx", with several improvements:
  4289 goals no longer need to be stated as "<prems> ==> False", equivalences
  4290 (i.e. "=" on type bool) are handled, variable names of the form
  4291 "lit_<n>" are no longer reserved, significant speedup.
  4292 
  4293 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4294 zChaff is still supported as well.
  4295 
  4296 * 'inductive' and 'datatype': provide projections of mutual rules,
  4297 bundled as foo_bar.inducts;
  4298 
  4299 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4300 Library.
  4301 
  4302 * Library: moved theory Accessible_Part to main HOL.
  4303 
  4304 * Library: added theory Coinductive_List of potentially infinite lists
  4305 as greatest fixed-point.
  4306 
  4307 * Library: added theory AssocList which implements (finite) maps as
  4308 association lists.
  4309 
  4310 * Method "evaluation" solves goals (i.e. a boolean expression)
  4311 efficiently by compiling it to ML.  The goal is "proved" (via an
  4312 oracle) if it evaluates to True.
  4313 
  4314 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4315 also when invoked by the simplifier.  This results in the Simplifier
  4316 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4317 Configuration option fast_arith_split_limit=0 recovers the old
  4318 behavior.
  4319 
  4320 * Support for hex (0x20) and binary (0b1001) numerals.
  4321 
  4322 * New method: reify eqs (t), where eqs are equations for an
  4323 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4324 parameter, computes a term s::'b and a list xs::'a list and proves the
  4325 theorem I xs s = t. This is also known as reification or quoting. The
  4326 resulting theorem is applied to the subgoal to substitute t with I xs
  4327 s.  If t is omitted, the subgoal itself is reified.
  4328 
  4329 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4330 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4331 where f is supposed to be a computable function (in the sense of code
  4332 generattion). The method uses reify to compute s and xs as above then
  4333 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4334 r and finally gets the theorem t = r, which is again applied to the
  4335 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4336 
  4337 * Reflection: Automatic reification now handels binding, an example is
  4338 available in src/HOL/ex/ReflectionEx.thy
  4339 
  4340 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4341 command 'statespace' that is similar to 'record', but introduces an
  4342 abstract specification based on the locale infrastructure instead of
  4343 HOL types.  This leads to extra flexibility in composing state spaces,
  4344 in particular multiple inheritance and renaming of components.
  4345 
  4346 
  4347 *** HOL-Complex ***
  4348 
  4349 * Hyperreal: Functions root and sqrt are now defined on negative real
  4350 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4351 Nonnegativity side conditions have been removed from many lemmas, so
  4352 that more subgoals may now be solved by simplification; potential
  4353 INCOMPATIBILITY.
  4354 
  4355 * Real: new type classes formalize real normed vector spaces and
  4356 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4357 and norm :: 'a => real.
  4358 
  4359 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4360 reals into other types. The overloaded constant Reals :: 'a set is now
  4361 defined as range of_real; potential INCOMPATIBILITY.
  4362 
  4363 * Real: proper support for ML code generation, including 'quickcheck'.
  4364 Reals are implemented as arbitrary precision rationals.
  4365 
  4366 * Hyperreal: Several constants that previously worked only for the
  4367 reals have been generalized, so they now work over arbitrary vector
  4368 spaces. Type annotations may need to be added in some cases; potential
  4369 INCOMPATIBILITY.
  4370 
  4371   Infinitesimal  :: ('a::real_normed_vector) star set
  4372   HFinite        :: ('a::real_normed_vector) star set
  4373   HInfinite      :: ('a::real_normed_vector) star set
  4374   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4375   monad          :: ('a::real_normed_vector) star => 'a star set
  4376   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4377   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4378   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4379   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4380   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4381   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4382   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4383   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4384   sgn            :: 'a::real_normed_vector => 'a
  4385   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4386 
  4387 * Complex: Some complex-specific constants are now abbreviations for
  4388 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4389 hnorm.  Other constants have been entirely removed in favor of the
  4390 polymorphic versions (INCOMPATIBILITY):
  4391 
  4392   approx        <-- capprox
  4393   HFinite       <-- CFinite
  4394   HInfinite     <-- CInfinite
  4395   Infinitesimal <-- CInfinitesimal
  4396   monad         <-- cmonad
  4397   galaxy        <-- cgalaxy
  4398   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4399   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4400   (ns)deriv     <-- (ns)cderiv
  4401 
  4402 
  4403 *** HOL-Algebra ***
  4404 
  4405 * Formalisation of ideals and the quotient construction over rings.
  4406 
  4407 * Order and lattice theory no longer based on records.
  4408 INCOMPATIBILITY.
  4409 
  4410 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4411 greatest_closed.  INCOMPATIBILITY.
  4412 
  4413 * Method algebra is now set up via an attribute.  For examples see
  4414 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4415 of algebraic structures.
  4416 
  4417 * Renamed theory CRing to Ring.
  4418 
  4419 
  4420 *** HOL-Nominal ***
  4421 
  4422 * Substantial, yet incomplete support for nominal datatypes (binding
  4423 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4424 src/HOL/Nominal/Examples.  Prospective users should consult
  4425 http://isabelle.in.tum.de/nominal/
  4426 
  4427 
  4428 *** ML ***
  4429 
  4430 * ML basics: just one true type int, which coincides with IntInf.int
  4431 (even on SML/NJ).
  4432 
  4433 * ML within Isar: antiquotations allow to embed statically-checked
  4434 formal entities in the source, referring to the context available at
  4435 compile-time.  For example:
  4436 
  4437 ML {* @{sort "{zero,one}"} *}
  4438 ML {* @{typ "'a => 'b"} *}
  4439 ML {* @{term "%x. x"} *}
  4440 ML {* @{prop "x == y"} *}
  4441 ML {* @{ctyp "'a => 'b"} *}
  4442 ML {* @{cterm "%x. x"} *}
  4443 ML {* @{cprop "x == y"} *}
  4444 ML {* @{thm asm_rl} *}
  4445 ML {* @{thms asm_rl} *}
  4446 ML {* @{type_name c} *}
  4447 ML {* @{type_syntax c} *}
  4448 ML {* @{const_name c} *}
  4449 ML {* @{const_syntax c} *}
  4450 ML {* @{context} *}
  4451 ML {* @{theory} *}
  4452 ML {* @{theory Pure} *}
  4453 ML {* @{theory_ref} *}
  4454 ML {* @{theory_ref Pure} *}
  4455 ML {* @{simpset} *}
  4456 ML {* @{claset} *}
  4457 ML {* @{clasimpset} *}
  4458 
  4459 The same works for sources being ``used'' within an Isar context.
  4460 
  4461 * ML in Isar: improved error reporting; extra verbosity with
  4462 ML_Context.trace enabled.
  4463 
  4464 * Pure/General/table.ML: the join operations now works via exceptions
  4465 DUP/SAME instead of type option. This is simpler in simple cases, and
  4466 admits slightly more efficient complex applications.
  4467 
  4468 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4469 use Context.generic instead of just theory.
  4470 
  4471 * Pure: datatype Context.generic joins theory/Proof.context and
  4472 provides some facilities for code that works in either kind of
  4473 context, notably GenericDataFun for uniform theory and proof data.
  4474 
  4475 * Pure: simplified internal attribute type, which is now always
  4476 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4477 local (Proof.context) attributes have been discontinued, while
  4478 minimizing code duplication. Thm.rule_attribute and
  4479 Thm.declaration_attribute build canonical attributes; see also structure
  4480 Context for further operations on Context.generic, notably
  4481 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4482 declarations and definitions.
  4483 
  4484 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4485 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4486 init only required for impure data. INCOMPATIBILITY: empty really need
  4487 to be empty (no dependencies on theory content!)
  4488 
  4489 * Pure/kernel: consts certification ignores sort constraints given in
  4490 signature declarations. (This information is not relevant to the
  4491 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4492 potential INCOMPATIBILITY.
  4493 
  4494 * Pure: axiomatic type classes are now purely definitional, with
  4495 explicit proofs of class axioms and super class relations performed
  4496 internally. See Pure/axclass.ML for the main internal interfaces --
  4497 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4498 AxClass.axiomatize_class/classrel/arity supersede
  4499 Sign.add_classes/classrel/arities.
  4500 
  4501 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4502 global/local versions on theory vs. Proof.context have been
  4503 discontinued; Attrib.syntax and Method.syntax have been adapted
  4504 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4505 attributes, methods, etc.
  4506 
  4507 * Pure: several functions of signature "... -> theory -> theory * ..."
  4508 have been reoriented to "... -> theory -> ... * theory" in order to
  4509 allow natural usage in combination with the ||>, ||>>, |-> and
  4510 fold_map combinators.
  4511 
  4512 * Pure: official theorem names (closed derivations) and additional
  4513 comments (tags) are now strictly separate.  Name hints -- which are
  4514 maintained as tags -- may be attached any time without affecting the
  4515 derivation.
  4516 
  4517 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4518 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4519 achieve the old behaviour.
  4520 
  4521 * Pure: the "Goal" constant is now called "prop", supporting a
  4522 slightly more general idea of ``protecting'' meta-level rule
  4523 statements.
  4524 
  4525 * Pure: Logic.(un)varify only works in a global context, which is now
  4526 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4527 Logic.legacy_(un)varify as temporary workaround.
  4528 
  4529 * Pure: structure Name provides scalable operations for generating
  4530 internal variable names, notably Name.variants etc.  This replaces
  4531 some popular functions from term.ML:
  4532 
  4533   Term.variant		->  Name.variant
  4534   Term.variantlist	->  Name.variant_list
  4535   Term.invent_names	->  Name.invent_list
  4536 
  4537 Note that low-level renaming rarely occurs in new code -- operations
  4538 from structure Variable are used instead (see below).
  4539 
  4540 * Pure: structure Variable provides fundamental operations for proper
  4541 treatment of fixed/schematic variables in a context.  For example,
  4542 Variable.import introduces fixes for schematics of given facts and
  4543 Variable.export reverses the effect (up to renaming) -- this replaces
  4544 various freeze_thaw operations.
  4545 
  4546 * Pure: structure Goal provides simple interfaces for
  4547 init/conclude/finish and tactical prove operations (replacing former
  4548 Tactic.prove).  Goal.prove is the canonical way to prove results
  4549 within a given context; Goal.prove_global is a degraded version for
  4550 theory level goals, including a global Drule.standard.  Note that
  4551 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4552 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4553 in a locale context).
  4554 
  4555 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4556 and type checking (Syntax.check_term etc.), with common combinations
  4557 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4558 which are considered legacy and await removal.
  4559 
  4560 * Pure/Syntax: generic interfaces for type unchecking
  4561 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4562 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4563 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4564 available for convenience, but refer to the very same operations using
  4565 a mere theory instead of a full context.
  4566 
  4567 * Isar: simplified treatment of user-level errors, using exception
  4568 ERROR of string uniformly.  Function error now merely raises ERROR,
  4569 without any side effect on output channels.  The Isar toplevel takes
  4570 care of proper display of ERROR exceptions.  ML code may use plain
  4571 handle/can/try; cat_error may be used to concatenate errors like this:
  4572 
  4573   ... handle ERROR msg => cat_error msg "..."
  4574 
  4575 Toplevel ML code (run directly or through the Isar toplevel) may be
  4576 embedded into the Isar toplevel with exception display/debug like
  4577 this:
  4578 
  4579   Isar.toplevel (fn () => ...)
  4580 
  4581 INCOMPATIBILITY, removed special transform_error facilities, removed
  4582 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4583 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4584 -- use plain ERROR instead.
  4585 
  4586 * Isar: theory setup now has type (theory -> theory), instead of a
  4587 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4588 
  4589 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4590 ProofContext.debug/verbose flags.
  4591 
  4592 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4593 theory before entering a proof state.  Transactions now always see a
  4594 quasi-functional intermediate checkpoint, both in interactive and
  4595 batch mode.
  4596 
  4597 * Isar: simplified interfaces for outer syntax.  Renamed
  4598 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4599 OuterSyntax.add_parsers -- this functionality is now included in
  4600 OuterSyntax.command etc.  INCOMPATIBILITY.
  4601 
  4602 * Simplifier: the simpset of a running simplification process now
  4603 contains a proof context (cf. Simplifier.the_context), which is the
  4604 very context that the initial simpset has been retrieved from (by
  4605 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4606 (solver, looper etc.) may depend on arbitrary proof data.
  4607 
  4608 * Simplifier.inherit_context inherits the proof context (plus the
  4609 local bounds) of the current simplification process; any simproc
  4610 etc. that calls the Simplifier recursively should do this!  Removed
  4611 former Simplifier.inherit_bounds, which is already included here --
  4612 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4613 specify an explicit context using Simplifier.context/theory_context.
  4614 
  4615 * Simplifier/Classical Reasoner: more abstract interfaces
  4616 change_simpset/claset for modifying the simpset/claset reference of a
  4617 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4618 INCOMPATIBILITY.
  4619 
  4620 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4621 "Trueprop" etc.
  4622 
  4623 
  4624 *** System ***
  4625 
  4626 * settings: the default heap location within ISABELLE_HOME_USER now
  4627 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4628 Isabelle installations.
  4629 
  4630 * isabelle-process: option -S (secure mode) disables some critical
  4631 operations, notably runtime compilation and evaluation of ML source
  4632 code.
  4633 
  4634 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4635 
  4636 * Support for parallel execution, using native multicore support of
  4637 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4638 independent theories, according to the given theory header
  4639 specifications. The maximum number of worker threads is specified via
  4640 usedir option -M or the "max-threads" setting in Proof General. A
  4641 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4642 to 6 on a 8-core machine.  User-code needs to observe certain
  4643 guidelines for thread-safe programming, see appendix A in the Isar
  4644 Implementation manual.
  4645 
  4646 
  4647 
  4648 New in Isabelle2005 (October 2005)
  4649 ----------------------------------
  4650 
  4651 *** General ***
  4652 
  4653 * Theory headers: the new header syntax for Isar theories is
  4654 
  4655   theory <name>
  4656   imports <theory1> ... <theoryN>
  4657   uses <file1> ... <fileM>
  4658   begin
  4659 
  4660 where the 'uses' part is optional.  The previous syntax
  4661 
  4662   theory <name> = <theory1> + ... + <theoryN>:
  4663 
  4664 will disappear in the next release.  Use isatool fixheaders to convert
  4665 existing theory files.  Note that there is no change in ancient
  4666 non-Isar theories now, but these will disappear soon.
  4667 
  4668 * Theory loader: parent theories can now also be referred to via
  4669 relative and absolute paths.
  4670 
  4671 * Command 'find_theorems' searches for a list of criteria instead of a
  4672 list of constants. Known criteria are: intro, elim, dest, name:string,
  4673 simp:term, and any term. Criteria can be preceded by '-' to select
  4674 theorems that do not match. Intro, elim, dest select theorems that
  4675 match the current goal, name:s selects theorems whose fully qualified
  4676 name contain s, and simp:term selects all simplification rules whose
  4677 lhs match term.  Any other term is interpreted as pattern and selects
  4678 all theorems matching the pattern. Available in ProofGeneral under
  4679 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4680 
  4681   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4682 
  4683 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4684 matching the current goal as introduction rule and not having "HOL."
  4685 in their name (i.e. not being defined in theory HOL).
  4686 
  4687 * Command 'thms_containing' has been discontinued in favour of
  4688 'find_theorems'; INCOMPATIBILITY.
  4689 
  4690 * Communication with Proof General is now 8bit clean, which means that
  4691 Unicode text in UTF-8 encoding may be used within theory texts (both
  4692 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4693 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4694 
  4695   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4696   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4697 
  4698 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4699 Classical Reasoner.  Typical big applications run around 2 times
  4700 faster.
  4701 
  4702 
  4703 *** Document preparation ***
  4704 
  4705 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4706 of raw sources.  Only those symbols that do not require additional
  4707 LaTeX packages (depending on comments in isabellesym.sty) are
  4708 displayed properly, everything else is left verbatim.  isatool display
  4709 and isatool print are used as front ends (these are subject to the
  4710 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4711 
  4712 * Command tags control specific markup of certain regions of text,
  4713 notably folding and hiding.  Predefined tags include "theory" (for
  4714 theory begin and end), "proof" for proof commands, and "ML" for
  4715 commands involving ML code; the additional tags "visible" and
  4716 "invisible" are unused by default.  Users may give explicit tag
  4717 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4718 interpretation of tags is determined by the LaTeX job during document
  4719 preparation: see option -V of isatool usedir, or options -n and -t of
  4720 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4721 \isadroptag.
  4722 
  4723 Several document versions may be produced at the same time via isatool
  4724 usedir (the generated index.html will link all of them).  Typical
  4725 specifications include ''-V document=theory,proof,ML'' to present
  4726 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4727 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4728 these parts without any formal replacement text.  The Isabelle site
  4729 default settings produce ''document'' and ''outline'' versions as
  4730 specified above.
  4731 
  4732 * Several new antiquotations:
  4733 
  4734   @{term_type term} prints a term with its type annotated;
  4735 
  4736   @{typeof term} prints the type of a term;
  4737 
  4738   @{const const} is the same as @{term const}, but checks that the
  4739   argument is a known logical constant;
  4740 
  4741   @{term_style style term} and @{thm_style style thm} print a term or
  4742   theorem applying a "style" to it
  4743 
  4744   @{ML text}
  4745 
  4746 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4747 definitions, equations, inequations etc., 'concl' printing only the
  4748 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4749 to print the specified premise.  TermStyle.add_style provides an ML
  4750 interface for introducing further styles.  See also the "LaTeX Sugar"
  4751 document practical applications.  The ML antiquotation prints
  4752 type-checked ML expressions verbatim.
  4753 
  4754 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4755 and 'text' support optional locale specification '(in loc)', which
  4756 specifies the default context for interpreting antiquotations.  For
  4757 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4758 
  4759 * Option 'locale=NAME' of antiquotations specifies an alternative
  4760 context interpreting the subsequent argument.  For example: @{thm
  4761 [locale=lattice] inf_assoc}.
  4762 
  4763 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4764 a proof context.
  4765 
  4766 * Proper output of antiquotations for theory commands involving a
  4767 proof context (such as 'locale' or 'theorem (in loc) ...').
  4768 
  4769 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4770 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4771 
  4772 * isatool usedir: new option -C (default true) controls whether option
  4773 -D should include a copy of the original document directory; -C false
  4774 prevents unwanted effects such as copying of administrative CVS data.
  4775 
  4776 
  4777 *** Pure ***
  4778 
  4779 * Considerably improved version of 'constdefs' command.  Now performs
  4780 automatic type-inference of declared constants; additional support for
  4781 local structure declarations (cf. locales and HOL records), see also
  4782 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4783 sequential dependencies of definitions within a single 'constdefs'
  4784 section; moreover, the declared name needs to be an identifier.  If
  4785 all fails, consider to fall back on 'consts' and 'defs' separately.
  4786 
  4787 * Improved indexed syntax and implicit structures.  First of all,
  4788 indexed syntax provides a notational device for subscripted
  4789 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4790 expressions.  Secondly, in a local context with structure
  4791 declarations, number indexes \<^sub>n or the empty index (default
  4792 number 1) refer to a certain fixed variable implicitly; option
  4793 show_structs controls printing of implicit structures.  Typical
  4794 applications of these concepts involve record types and locales.
  4795 
  4796 * New command 'no_syntax' removes grammar declarations (and
  4797 translations) resulting from the given syntax specification, which is
  4798 interpreted in the same manner as for the 'syntax' command.
  4799 
  4800 * 'Advanced' translation functions (parse_translation etc.) may depend
  4801 on the signature of the theory context being presently used for
  4802 parsing/printing, see also isar-ref manual.
  4803 
  4804 * Improved 'oracle' command provides a type-safe interface to turn an
  4805 ML expression of type theory -> T -> term into a primitive rule of
  4806 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4807 is already included here); see also FOL/ex/IffExample.thy;
  4808 INCOMPATIBILITY.
  4809 
  4810 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4811 before); "cI" is no longer bound, use "c.intro" instead.
  4812 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4813 axclasses vs. locales.
  4814 
  4815 * Improved internal renaming of symbolic identifiers -- attach primes
  4816 instead of base 26 numbers.
  4817 
  4818 * New flag show_question_marks controls printing of leading question
  4819 marks in schematic variable names.
  4820 
  4821 * In schematic variable names, *any* symbol following \<^isub> or
  4822 \<^isup> is now treated as part of the base name.  For example, the
  4823 following works without printing of awkward ".0" indexes:
  4824 
  4825   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4826     by simp
  4827 
  4828 * Inner syntax includes (*(*nested*) comments*).
  4829 
  4830 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4831 annotations as "(00...)".
  4832 
  4833 * Clear separation of logical types and nonterminals, where the latter
  4834 may only occur in 'syntax' specifications or type abbreviations.
  4835 Before that distinction was only partially implemented via type class
  4836 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4837 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4838 exotic syntax specifications may require further adaption
  4839 (e.g. Cube/Cube.thy).
  4840 
  4841 * Removed obsolete type class "logic", use the top sort {} instead.
  4842 Note that non-logical types should be declared as 'nonterminals'
  4843 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4844 specifications.
  4845 
  4846 * Attributes 'induct' and 'cases': type or set names may now be
  4847 locally fixed variables as well.
  4848 
  4849 * Simplifier: can now control the depth to which conditional rewriting
  4850 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4851 Limit.
  4852 
  4853 * Simplifier: simplification procedures may now take the current
  4854 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4855 interface), which is very useful for calling the Simplifier
  4856 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4857 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4858 low-level mk_simproc no longer applies Logic.varify internally, to
  4859 allow for use in a context of fixed variables.
  4860 
  4861 * thin_tac now works even if the assumption being deleted contains !!
  4862 or ==>.  More generally, erule now works even if the major premise of
  4863 the elimination rule contains !! or ==>.
  4864 
  4865 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4866 
  4867 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4868 from Pure, which contains all common declarations already.  Both
  4869 theories are defined via plain Isabelle/Isar .thy files.
  4870 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4871 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4872 use isatool fixcpure to adapt your theory and ML sources.
  4873 
  4874 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4875 selections of theorems in named facts via index ranges.
  4876 
  4877 * 'print_theorems': in theory mode, really print the difference
  4878 wrt. the last state (works for interactive theory development only),
  4879 in proof mode print all local facts (cf. 'print_facts');
  4880 
  4881 * 'hide': option '(open)' hides only base names.
  4882 
  4883 * More efficient treatment of intermediate checkpoints in interactive
  4884 theory development.
  4885 
  4886 * Code generator is now invoked via code_module (incremental code
  4887 generation) and code_library (modular code generation, ML structures
  4888 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4889 must be quoted when used as identifiers.
  4890 
  4891 * New 'value' command for reading, evaluating and printing terms using
  4892 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4893 quoted when used as identifier.
  4894 
  4895 
  4896 *** Locales ***
  4897 
  4898 * New commands for the interpretation of locale expressions in
  4899 theories (1), locales (2) and proof contexts (3).  These generate
  4900 proof obligations from the expression specification.  After the
  4901 obligations have been discharged, theorems of the expression are added
  4902 to the theory, target locale or proof context.  The synopsis of the
  4903 commands is a follows:
  4904 
  4905   (1) interpretation expr inst
  4906   (2) interpretation target < expr
  4907   (3) interpret expr inst
  4908 
  4909 Interpretation in theories and proof contexts require a parameter
  4910 instantiation of terms from the current context.  This is applied to
  4911 specifications and theorems of the interpreted expression.
  4912 Interpretation in locales only permits parameter renaming through the
  4913 locale expression.  Interpretation is smart in that interpretations
  4914 that are active already do not occur in proof obligations, neither are
  4915 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4916 inspect active interpretations of a particular locale.  For details,
  4917 see the Isar Reference manual.  Examples can be found in
  4918 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4919 
  4920 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4921 'interpret' instead.
  4922 
  4923 * New context element 'constrains' for adding type constraints to
  4924 parameters.
  4925 
  4926 * Context expressions: renaming of parameters with syntax
  4927 redeclaration.
  4928 
  4929 * Locale declaration: 'includes' disallowed.
  4930 
  4931 * Proper static binding of attribute syntax -- i.e. types / terms /
  4932 facts mentioned as arguments are always those of the locale definition
  4933 context, independently of the context of later invocations.  Moreover,
  4934 locale operations (renaming and type / term instantiation) are applied
  4935 to attribute arguments as expected.
  4936 
  4937 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4938 actual attributes; rare situations may require Attrib.attribute to
  4939 embed those attributes into Attrib.src that lack concrete syntax.
  4940 Attribute implementations need to cooperate properly with the static
  4941 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4942 Attrib.XXX_thm etc. already do the right thing without further
  4943 intervention.  Only unusual applications -- such as "where" or "of"
  4944 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4945 on the context and the facts involved -- may have to assign parsed
  4946 values to argument tokens explicitly.
  4947 
  4948 * Changed parameter management in theorem generation for long goal
  4949 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4950 theorem statement in rare situations.
  4951 
  4952 * Locale inspection command 'print_locale' omits notes elements.  Use
  4953 'print_locale!' to have them included in the output.
  4954 
  4955 
  4956 *** Provers ***
  4957 
  4958 * Provers/hypsubst.ML: improved version of the subst method, for
  4959 single-step rewriting: it now works in bound variable contexts. New is
  4960 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4961 rewrite a different subterm than the original subst method, which is
  4962 still available as 'simplesubst'.
  4963 
  4964 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4965 and quasi orders.
  4966 
  4967 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4968 reflexive-transitive closure of relations.
  4969 
  4970 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4971 limit (previously hard-coded with a value of 20) user-definable.
  4972 
  4973 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4974 is peformed already.  Object-logics merely need to finish their
  4975 initial simpset configuration as before.  INCOMPATIBILITY.
  4976 
  4977 
  4978 *** HOL ***
  4979 
  4980 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4981 
  4982   syntax (epsilon)
  4983     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4984 
  4985 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4986 and x-symbol; use option '-m epsilon' to get it actually printed.
  4987 Moreover, the mathematically important symbolic identifier \<epsilon>
  4988 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4989 
  4990 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4991 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4992 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4993 support corresponding Isar calculations.
  4994 
  4995 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4996 instead of ":".
  4997 
  4998 * theory SetInterval: changed the syntax for open intervals:
  4999 
  5000   Old       New
  5001   {..n(}    {..<n}
  5002   {)n..}    {n<..}
  5003   {m..n(}   {m..<n}
  5004   {)m..n}   {m<..n}
  5005   {)m..n(}  {m<..<n}
  5006 
  5007 The old syntax is still supported but will disappear in the next
  5008 release.  For conversion use the following Emacs search and replace
  5009 patterns (these are not perfect but work quite well):
  5010 
  5011   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5012   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5013 
  5014 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5015 equalities in commutative rings; method 'algebra' provides a generic
  5016 interface.
  5017 
  5018 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5019 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5020 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5021 be a tuple pattern.
  5022 
  5023 Some new syntax forms are available:
  5024 
  5025   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5026   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5027   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5028   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5029 
  5030 The latter form "\<Sum>x < k. e" used to be based on a separate
  5031 function "Summation", which has been discontinued.
  5032 
  5033 * theory Finite_Set: in structured induction proofs, the insert case
  5034 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5035 (insert F x)'.
  5036 
  5037 * The 'refute' command has been extended to support a much larger
  5038 fragment of HOL, including axiomatic type classes, constdefs and
  5039 typedefs, inductive datatypes and recursion.
  5040 
  5041 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5042 Requires zChaff with proof generation to be installed.  See
  5043 HOL/ex/SAT_Examples.thy for examples.
  5044 
  5045 * Datatype induction via method 'induct' now preserves the name of the
  5046 induction variable. For example, when proving P(xs::'a list) by
  5047 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5048 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5049 in unstructured proof scripts.
  5050 
  5051 * Reworked implementation of records.  Improved scalability for
  5052 records with many fields, avoiding performance problems for type
  5053 inference. Records are no longer composed of nested field types, but
  5054 of nested extension types. Therefore the record type only grows linear
  5055 in the number of extensions and not in the number of fields.  The
  5056 top-level (users) view on records is preserved.  Potential
  5057 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5058 old record representation. The type generated for a record is called
  5059 <record_name>_ext_type.
  5060 
  5061 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5062 proofs triggered by a record definition or a simproc (if
  5063 quick_and_dirty is enabled).  Definitions of large records can take
  5064 quite long.
  5065 
  5066 New simproc record_upd_simproc for simplification of multiple record
  5067 updates enabled by default.  Moreover, trivial updates are also
  5068 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5069 occasionally, since simplification is more powerful by default.
  5070 
  5071 * typedef: proper support for polymorphic sets, which contain extra
  5072 type-variables in the term.
  5073 
  5074 * Simplifier: automatically reasons about transitivity chains
  5075 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5076 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5077 old proofs break occasionally as simplification may now solve more
  5078 goals than previously.
  5079 
  5080 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5081 present.  Works for all partial orders (class "order"), in particular
  5082 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5083 just like y <= x.
  5084 
  5085 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5086 bound variable or a constant then the let is unfolded.  Otherwise
  5087 first a is simplified to b, and then f b is simplified to g. If
  5088 possible we abstract b from g arriving at "let x = b in h x",
  5089 otherwise we unfold the let and arrive at g.  The simproc can be
  5090 enabled/disabled by the reference use_let_simproc.  Potential
  5091 INCOMPATIBILITY since simplification is more powerful by default.
  5092 
  5093 * Classical reasoning: the meson method now accepts theorems as arguments.
  5094 
  5095 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5096 jobs to provide advice on the provability of subgoals.
  5097 
  5098 * Theory OrderedGroup and Ring_and_Field: various additions and
  5099 improvements to faciliate calculations involving equalities and
  5100 inequalities.
  5101 
  5102 The following theorems have been eliminated or modified
  5103 (INCOMPATIBILITY):
  5104 
  5105   abs_eq             now named abs_of_nonneg
  5106   abs_of_ge_0        now named abs_of_nonneg
  5107   abs_minus_eq       now named abs_of_nonpos
  5108   imp_abs_id         now named abs_of_nonneg
  5109   imp_abs_neg_id     now named abs_of_nonpos
  5110   mult_pos           now named mult_pos_pos
  5111   mult_pos_le        now named mult_nonneg_nonneg
  5112   mult_pos_neg_le    now named mult_nonneg_nonpos
  5113   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5114   mult_neg           now named mult_neg_neg
  5115   mult_neg_le        now named mult_nonpos_nonpos
  5116 
  5117 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5118      
  5119      zero_le_square
  5120      not_square_less_zero 
  5121 
  5122   The following lemmas have been deleted from Real/RealPow:
  5123   
  5124      realpow_zero_zero
  5125      realpow_two
  5126      realpow_less
  5127      zero_le_power
  5128      realpow_two_le
  5129      abs_realpow_two
  5130      realpow_two_abs     
  5131 
  5132 * Theory Parity: added rules for simplifying exponents.
  5133 
  5134 * Theory List:
  5135 
  5136 The following theorems have been eliminated or modified
  5137 (INCOMPATIBILITY):
  5138 
  5139   list_all_Nil       now named list_all.simps(1)
  5140   list_all_Cons      now named list_all.simps(2)
  5141   list_all_conv      now named list_all_iff
  5142   set_mem_eq         now named mem_iff
  5143 
  5144 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5145 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5146 
  5147 
  5148 *** HOL-Complex ***
  5149 
  5150 * Theory RealDef: better support for embedding natural numbers and
  5151 integers in the reals.
  5152 
  5153 The following theorems have been eliminated or modified
  5154 (INCOMPATIBILITY):
  5155 
  5156   exp_ge_add_one_self  now requires no hypotheses
  5157   real_of_int_add      reversed direction of equality (use [symmetric])
  5158   real_of_int_minus    reversed direction of equality (use [symmetric])
  5159   real_of_int_diff     reversed direction of equality (use [symmetric])
  5160   real_of_int_mult     reversed direction of equality (use [symmetric])
  5161 
  5162 * Theory RComplete: expanded support for floor and ceiling functions.
  5163 
  5164 * Theory Ln is new, with properties of the natural logarithm
  5165 
  5166 * Hyperreal: There is a new type constructor "star" for making
  5167 nonstandard types.  The old type names are now type synonyms:
  5168 
  5169   hypreal = real star
  5170   hypnat = nat star
  5171   hcomplex = complex star
  5172 
  5173 * Hyperreal: Many groups of similarly-defined constants have been
  5174 replaced by polymorphic versions (INCOMPATIBILITY):
  5175 
  5176   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5177 
  5178   starset      <-- starsetNat, starsetC
  5179   *s*          <-- *sNat*, *sc*
  5180   starset_n    <-- starsetNat_n, starsetC_n
  5181   *sn*         <-- *sNatn*, *scn*
  5182   InternalSets <-- InternalNatSets, InternalCSets
  5183 
  5184   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5185   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5186   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5187   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5188   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5189 
  5190 * Hyperreal: Many type-specific theorems have been removed in favor of
  5191 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5192 
  5193   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5194   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5195   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5196   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5197   right_minus <-- hypreal_add_minus
  5198   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5199   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5200   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5201   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5202   mult_1_right <-- hcomplex_mult_one_right
  5203   mult_zero_left <-- hcomplex_mult_zero_left
  5204   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5205   right_distrib <-- hypnat_add_mult_distrib2
  5206   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5207   right_inverse <-- hypreal_mult_inverse
  5208   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5209   order_refl <-- {hypreal,hypnat}_le_refl
  5210   order_trans <-- {hypreal,hypnat}_le_trans
  5211   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5212   order_less_le <-- {hypreal,hypnat}_less_le
  5213   linorder_linear <-- {hypreal,hypnat}_le_linear
  5214   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5215   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5216   add_nonneg_nonneg <-- hypreal_le_add_order
  5217 
  5218 * Hyperreal: Separate theorems having to do with type-specific
  5219 versions of constants have been merged into theorems that apply to the
  5220 new polymorphic constants (INCOMPATIBILITY):
  5221 
  5222   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5223   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5224   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5225   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5226   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5227   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5228   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5229   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5230   STAR_diff <-- {STAR,STARC}_diff
  5231   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5232     STARC_hcomplex_of_complex}_image_subset
  5233   starset_n_Un <-- starset{Nat,C}_n_Un
  5234   starset_n_Int <-- starset{Nat,C}_n_Int
  5235   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5236   starset_n_diff <-- starset{Nat,C}_n_diff
  5237   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5238   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5239   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5240   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5241   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5242   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5243   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5244   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5245   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5246   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5247   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5248   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5249   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5250   starfun_diff <-- starfun{C,RC,CR}_diff
  5251   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5252   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5253   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5254   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5255   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5256   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5257   starfun_Id <-- starfunC_Id
  5258   starfun_approx <-- starfun{Nat,CR}_approx
  5259   starfun_capprox <-- starfun{C,RC}_capprox
  5260   starfun_abs <-- starfunNat_rabs
  5261   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5262   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5263   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5264   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5265   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5266   starfun_add_approx <-- starfunCR_add_approx
  5267   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5268   starfun_divide <-- starfun{C,CR,RC}_divide
  5269   starfun_n <-- starfun{Nat,C}_n
  5270   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5271   starfun_n_add <-- starfun{Nat,C}_n_add
  5272   starfun_n_add_minus <-- starfunNat_n_add_minus
  5273   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5274   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5275   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5276 
  5277   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5278   star_n_minus <-- {hypreal,hcomplex}_minus
  5279   star_n_diff <-- {hypreal,hcomplex}_diff
  5280   star_n_mult <-- {hypreal,hcomplex}_mult
  5281   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5282   star_n_le <-- {hypreal,hypnat}_le
  5283   star_n_less <-- {hypreal,hypnat}_less
  5284   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5285   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5286   star_n_abs <-- hypreal_hrabs
  5287   star_n_divide <-- hcomplex_divide
  5288 
  5289   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5290   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5291   star_of_diff <-- hypreal_of_real_diff
  5292   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5293   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5294   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5295   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5296   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5297   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5298   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5299   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5300   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5301   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5302   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5303   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5304   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5305   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5306   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5307   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5308   star_of_power <-- hypreal_of_real_power
  5309   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5310 
  5311 * Hyperreal: new method "transfer" that implements the transfer
  5312 principle of nonstandard analysis. With a subgoal that mentions
  5313 nonstandard types like "'a star", the command "apply transfer"
  5314 replaces it with an equivalent one that mentions only standard types.
  5315 To be successful, all free variables must have standard types; non-
  5316 standard variables must have explicit universal quantifiers.
  5317 
  5318 * Hyperreal: A theory of Taylor series.
  5319 
  5320 
  5321 *** HOLCF ***
  5322 
  5323 * Discontinued special version of 'constdefs' (which used to support
  5324 continuous functions) in favor of the general Pure one with full
  5325 type-inference.
  5326 
  5327 * New simplification procedure for solving continuity conditions; it
  5328 is much faster on terms with many nested lambda abstractions (cubic
  5329 instead of exponential time).
  5330 
  5331 * New syntax for domain package: selector names are now optional.
  5332 Parentheses should be omitted unless argument is lazy, for example:
  5333 
  5334   domain 'a stream = cons "'a" (lazy "'a stream")
  5335 
  5336 * New command 'fixrec' for defining recursive functions with pattern
  5337 matching; defining multiple functions with mutual recursion is also
  5338 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5339 sinr, or any data constructor defined by the domain package. The given
  5340 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5341 syntax and examples.
  5342 
  5343 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5344 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5345 but the proof obligation additionally includes an admissibility
  5346 requirement. The packages generate instances of class cpo or pcpo,
  5347 with continuity and strictness theorems for Rep and Abs.
  5348 
  5349 * HOLCF: Many theorems have been renamed according to a more standard naming
  5350 scheme (INCOMPATIBILITY):
  5351 
  5352   foo_inject:  "foo$x = foo$y ==> x = y"
  5353   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5354   foo_less:    "(foo$x << foo$y) = (x << y)"
  5355   foo_strict:  "foo$UU = UU"
  5356   foo_defined: "... ==> foo$x ~= UU"
  5357   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5358 
  5359 
  5360 *** ZF ***
  5361 
  5362 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5363 including the First Isomorphism Theorem (on quotienting by the kernel
  5364 of a homomorphism).
  5365 
  5366 * ZF/Simplifier: install second copy of type solver that actually
  5367 makes use of TC rules declared to Isar proof contexts (or locales);
  5368 the old version is still required for ML proof scripts.
  5369 
  5370 
  5371 *** Cube ***
  5372 
  5373 * Converted to Isar theory format; use locales instead of axiomatic
  5374 theories.
  5375 
  5376 
  5377 *** ML ***
  5378 
  5379 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5380 for ||>, ||>>, |>>,
  5381 
  5382 * Pure/library.ML no longer defines its own option datatype, but uses
  5383 that of the SML basis, which has constructors NONE and SOME instead of
  5384 None and Some, as well as exception Option.Option instead of OPTION.
  5385 The functions the, if_none, is_some, is_none have been adapted
  5386 accordingly, while Option.map replaces apsome.
  5387 
  5388 * Pure/library.ML: the exception LIST has been given up in favour of
  5389 the standard exceptions Empty and Subscript, as well as
  5390 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5391 superceded by the standard hd and tl functions etc.
  5392 
  5393 A number of basic list functions are no longer exported to the ML
  5394 toplevel, as they are variants of predefined functions.  The following
  5395 suggests how one can translate existing code:
  5396 
  5397     rev_append xs ys = List.revAppend (xs, ys)
  5398     nth_elem (i, xs) = List.nth (xs, i)
  5399     last_elem xs = List.last xs
  5400     flat xss = List.concat xss
  5401     seq fs = List.app fs
  5402     partition P xs = List.partition P xs
  5403     mapfilter f xs = List.mapPartial f xs
  5404 
  5405 * Pure/library.ML: several combinators for linear functional
  5406 transformations, notably reverse application and composition:
  5407 
  5408   x |> f                f #> g
  5409   (x, y) |-> f          f #-> g
  5410 
  5411 * Pure/library.ML: introduced/changed precedence of infix operators:
  5412 
  5413   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5414   infix 2 ?;
  5415   infix 3 o oo ooo oooo;
  5416   infix 4 ~~ upto downto;
  5417 
  5418 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5419 infix operators.
  5420 
  5421 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5422 fold_map support linear functional transformations and nesting.  For
  5423 example:
  5424 
  5425   fold f [x1, ..., xN] y =
  5426     y |> f x1 |> ... |> f xN
  5427 
  5428   (fold o fold) f [xs1, ..., xsN] y =
  5429     y |> fold f xs1 |> ... |> fold f xsN
  5430 
  5431   fold f [x1, ..., xN] =
  5432     f x1 #> ... #> f xN
  5433 
  5434   (fold o fold) f [xs1, ..., xsN] =
  5435     fold f xs1 #> ... #> fold f xsN
  5436 
  5437 * Pure/library.ML: the following selectors on type 'a option are
  5438 available:
  5439 
  5440   the:               'a option -> 'a  (*partial*)
  5441   these:             'a option -> 'a  where 'a = 'b list
  5442   the_default: 'a -> 'a option -> 'a
  5443   the_list:          'a option -> 'a list
  5444 
  5445 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5446 basic operations for association lists, following natural argument
  5447 order; moreover the explicit equality predicate passed here avoids
  5448 potentially expensive polymorphic runtime equality checks.
  5449 The old functions may be expressed as follows:
  5450 
  5451   assoc = uncurry (AList.lookup (op =))
  5452   assocs = these oo AList.lookup (op =)
  5453   overwrite = uncurry (AList.update (op =)) o swap
  5454 
  5455 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5456 
  5457   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5458   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5459 
  5460 replacing make_keylist and keyfilter (occassionally used)
  5461 Naive rewrites:
  5462 
  5463   make_keylist = AList.make
  5464   keyfilter = AList.find (op =)
  5465 
  5466 * eq_fst and eq_snd now take explicit equality parameter, thus
  5467   avoiding eqtypes. Naive rewrites:
  5468 
  5469     eq_fst = eq_fst (op =)
  5470     eq_snd = eq_snd (op =)
  5471 
  5472 * Removed deprecated apl and apr (rarely used).
  5473   Naive rewrites:
  5474 
  5475     apl (n, op) =>>= curry op n
  5476     apr (op, m) =>>= fn n => op (n, m)
  5477 
  5478 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5479 provides a reasonably efficient light-weight implementation of sets as
  5480 lists.
  5481 
  5482 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5483 few new operations; existing lookup and update are now curried to
  5484 follow natural argument order (for use with fold etc.);
  5485 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5486 
  5487 * Pure/General: output via the Isabelle channels of
  5488 writeln/warning/error etc. is now passed through Output.output, with a
  5489 hook for arbitrary transformations depending on the print_mode
  5490 (cf. Output.add_mode -- the first active mode that provides a output
  5491 function wins).  Already formatted output may be embedded into further
  5492 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5493 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5494 accommodate easy composition of diagnostic messages etc.  Programmers
  5495 rarely need to care about Output.output or Output.raw at all, with
  5496 some notable exceptions: Output.output is required when bypassing the
  5497 standard channels (writeln etc.), or in token translations to produce
  5498 properly formatted results; Output.raw is required when capturing
  5499 already output material that will eventually be presented to the user
  5500 a second time.  For the default print mode, both Output.output and
  5501 Output.raw have no effect.
  5502 
  5503 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5504 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5505 cumulative results are displayed at the end of a batch session.
  5506 
  5507 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5508 replaced by File.platform_path and File.shell_path (with appropriate
  5509 hooks).  This provides a clean interface for unusual systems where the
  5510 internal and external process view of file names are different.
  5511 
  5512 * Pure: more efficient orders for basic syntactic entities: added
  5513 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5514 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5515 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5516 orders now -- potential INCOMPATIBILITY for code that depends on a
  5517 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5518 Library.sort_strings on result).
  5519 
  5520 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5521 fold_types traverse types/terms from left to right, observing natural
  5522 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5523 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5524 
  5525 * Pure: name spaces have been refined, with significant changes of the
  5526 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5527 to extern(_table).  The plain name entry path is superceded by a
  5528 general 'naming' context, which also includes the 'policy' to produce
  5529 a fully qualified name and external accesses of a fully qualified
  5530 name; NameSpace.extend is superceded by context dependent
  5531 Sign.declare_name.  Several theory and proof context operations modify
  5532 the naming context.  Especially note Theory.restore_naming and
  5533 ProofContext.restore_naming to get back to a sane state; note that
  5534 Theory.add_path is no longer sufficient to recover from
  5535 Theory.absolute_path in particular.
  5536 
  5537 * Pure: new flags short_names (default false) and unique_names
  5538 (default true) for controlling output of qualified names.  If
  5539 short_names is set, names are printed unqualified.  If unique_names is
  5540 reset, the name prefix is reduced to the minimum required to achieve
  5541 the original result when interning again, even if there is an overlap
  5542 with earlier declarations.
  5543 
  5544 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5545 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5546 (useful for printing error messages).  INCOMPATIBILITY.
  5547 
  5548 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5549 Theory.theory are now identified, referring to the universal
  5550 Context.theory (see Pure/context.ML).  Actual signature and theory
  5551 content is managed as theory data.  The old code and interfaces were
  5552 spread over many files and structures; the new arrangement introduces
  5553 considerable INCOMPATIBILITY to gain more clarity:
  5554 
  5555   Context -- theory management operations (name, identity, inclusion,
  5556     parents, ancestors, merge, etc.), plus generic theory data;
  5557 
  5558   Sign -- logical signature and syntax operations (declaring consts,
  5559     types, etc.), plus certify/read for common entities;
  5560 
  5561   Theory -- logical theory operations (stating axioms, definitions,
  5562     oracles), plus a copy of logical signature operations (consts,
  5563     types, etc.); also a few basic management operations (Theory.copy,
  5564     Theory.merge, etc.)
  5565 
  5566 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5567 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5568 for convenience -- they merely return the theory.
  5569 
  5570 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5571 
  5572 * Pure: the Isar proof context type is already defined early in Pure
  5573 as Context.proof (note that ProofContext.context and Proof.context are
  5574 aliases, where the latter is the preferred name).  This enables other
  5575 Isabelle components to refer to that type even before Isar is present.
  5576 
  5577 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5578 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5579 any of these kinds.  For example, Sign.intern typeK is now
  5580 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5581 Theory.hide_types.  Also note that former
  5582 Theory.hide_classes/types/consts are now
  5583 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5584 internalize their arguments!  INCOMPATIBILITY.
  5585 
  5586 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5587 datatype thmref (with constructors Name and NameSelection) instead of
  5588 plain string -- INCOMPATIBILITY;
  5589 
  5590 * Pure: cases produced by proof methods specify options, where NONE
  5591 means to remove case bindings -- INCOMPATIBILITY in
  5592 (RAW_)METHOD_CASES.
  5593 
  5594 * Pure: the following operations retrieve axioms or theorems from a
  5595 theory node or theory hierarchy, respectively:
  5596 
  5597   Theory.axioms_of: theory -> (string * term) list
  5598   Theory.all_axioms_of: theory -> (string * term) list
  5599   PureThy.thms_of: theory -> (string * thm) list
  5600   PureThy.all_thms_of: theory -> (string * thm) list
  5601 
  5602 * Pure: print_tac now outputs the goal through the trace channel.
  5603 
  5604 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5605 Reference Toplevel.debug (default false) controls detailed printing
  5606 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5607 controls execution profiling -- set to 1 for time and 2 for space
  5608 (both increase the runtime).
  5609 
  5610 * Isar session: The initial use of ROOT.ML is now always timed,
  5611 i.e. the log will show the actual process times, in contrast to the
  5612 elapsed wall-clock time that the outer shell wrapper produces.
  5613 
  5614 * Simplifier: improved handling of bound variables (nameless
  5615 representation, avoid allocating new strings).  Simprocs that invoke
  5616 the Simplifier recursively should use Simplifier.inherit_bounds to
  5617 avoid local name clashes.  Failure to do so produces warnings
  5618 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5619 for further details.
  5620 
  5621 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5622 bindings for all theorems stored within a given theory; this may help
  5623 in porting non-Isar theories to Isar ones, while keeping ML proof
  5624 scripts for the time being.
  5625 
  5626 * ML operator HTML.with_charset specifies the charset begin used for
  5627 generated HTML files.  For example:
  5628 
  5629   HTML.with_charset "utf-8" use_thy "Hebrew";
  5630   HTML.with_charset "utf-8" use_thy "Chinese";
  5631 
  5632 
  5633 *** System ***
  5634 
  5635 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5636 isabelle, isatool etc.).
  5637 
  5638 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5639 isatool doc, isatool mkdir, display_drafts etc.).
  5640 
  5641 * isatool usedir: option -f allows specification of the ML file to be
  5642 used by Isabelle; default is ROOT.ML.
  5643 
  5644 * New isatool version outputs the version identifier of the Isabelle
  5645 distribution being used.
  5646 
  5647 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5648 (containing Boolean satisfiability problems) into Isabelle/HOL
  5649 theories.
  5650 
  5651 
  5652 
  5653 New in Isabelle2004 (April 2004)
  5654 --------------------------------
  5655 
  5656 *** General ***
  5657 
  5658 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5659   Replaces linorder.ML.
  5660 
  5661 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5662   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5663   (\<a>...\<z>), are now considered normal letters, and can therefore
  5664   be used anywhere where an ASCII letter (a...zA...Z) has until
  5665   now. COMPATIBILITY: This obviously changes the parsing of some
  5666   terms, especially where a symbol has been used as a binder, say
  5667   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5668   as an identifier.  Fix it by inserting a space around former
  5669   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5670   existing theory and ML files.
  5671 
  5672 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5673 
  5674 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5675   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5676   a normal (but invisible) letter. For multiple letter subscripts repeat
  5677   \<^isub> like this: x\<^isub>1\<^isub>2.
  5678 
  5679 * Pure: There are now sub-/superscripts that can span more than one
  5680   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5681   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5682   superscript. The new control characters are not identifier parts.
  5683 
  5684 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5685   content of "..." to the latex file instead of \isacntrl... . The "..."
  5686   may consist of any printable characters excluding the end bracket >.
  5687 
  5688 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5689   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5690   declare constants "final", which prevents their being given a definition
  5691   later.  It is useful for constants whose behaviour is fixed axiomatically
  5692   rather than definitionally, such as the meta-logic connectives.
  5693 
  5694 * Pure: 'instance' now handles general arities with general sorts
  5695   (i.e. intersections of classes),
  5696 
  5697 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5698   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5699   It can be changed to alter the colors/layout of generated pages.
  5700 
  5701 
  5702 *** Isar ***
  5703 
  5704 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5705   cut_tac, subgoal_tac and thin_tac:
  5706   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5707     locales are no longer forced to write Isar proof scripts.
  5708     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5709     emulations.
  5710   - INCOMPATIBILITY: names of variables to be instantiated may no
  5711     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5712     This is consistent with the instantiation attribute "where".
  5713 
  5714 * Attributes "where" and "of":
  5715   - Now take type variables of instantiated theorem into account when reading
  5716     the instantiation string.  This fixes a bug that caused instantiated
  5717     theorems to have too special types in some circumstances.
  5718   - "where" permits explicit instantiations of type variables.
  5719 
  5720 * Calculation commands "moreover" and "also" no longer interfere with
  5721   current facts ("this"), admitting arbitrary combinations with "then"
  5722   and derived forms.
  5723 
  5724 * Locales:
  5725   - Goal statements involving the context element "includes" no longer
  5726     generate theorems with internal delta predicates (those ending on
  5727     "_axioms") in the premise.
  5728     Resolve particular premise with <locale>.intro to obtain old form.
  5729   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5730     specification and "includes" elements in goal statement.
  5731   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5732     [intro?] and [elim?] (respectively) by default.
  5733   - Experimental command for instantiation of locales in proof contexts:
  5734         instantiate <label>[<attrs>]: <loc>
  5735     Instantiates locale <loc> and adds all its theorems to the current context
  5736     taking into account their attributes.  Label and attrs are optional
  5737     modifiers, like in theorem declarations.  If present, names of
  5738     instantiated theorems are qualified with <label>, and the attributes
  5739     <attrs> are applied after any attributes these theorems might have already.
  5740       If the locale has assumptions, a chained fact of the form
  5741     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5742     are derived.  The command does not support old-style locales declared
  5743     with "locale (open)".
  5744       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5745 
  5746 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5747   (Isar) contexts.
  5748 
  5749 
  5750 *** HOL ***
  5751 
  5752 * Proof import: new image HOL4 contains the imported library from
  5753   the HOL4 system with about 2500 theorems. It is imported by
  5754   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5755   can be used like any other Isabelle image.  See
  5756   HOL/Import/HOL/README for more information.
  5757 
  5758 * Simplifier:
  5759   - Much improved handling of linear and partial orders.
  5760     Reasoners for linear and partial orders are set up for type classes
  5761     "linorder" and "order" respectively, and are added to the default simpset
  5762     as solvers.  This means that the simplifier can build transitivity chains
  5763     to solve goals from the assumptions.
  5764   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5765     of blast or auto after simplification become unnecessary because the goal
  5766     is solved by simplification already.
  5767 
  5768 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5769     all proved in axiomatic type classes for semirings, rings and fields.
  5770 
  5771 * Numerics:
  5772   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5773     now formalized using the Ring_and_Field theory mentioned above.
  5774   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5775     than before, because now they are set up once in a generic manner.
  5776   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5777     Look for the general versions in Ring_and_Field (and Power if they concern
  5778     exponentiation).
  5779 
  5780 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5781 
  5782 * Records:
  5783   - Record types are now by default printed with their type abbreviation
  5784     instead of the list of all field types. This can be configured via
  5785     the reference "print_record_type_abbr".
  5786   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5787     (not enabled by default).
  5788   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5789     EX x. x = sel r to True (not enabled by default).
  5790   - Tactic "record_split_simp_tac" to split and simplify records added.
  5791 
  5792 * 'specification' command added, allowing for definition by
  5793   specification.  There is also an 'ax_specification' command that
  5794   introduces the new constants axiomatically.
  5795 
  5796 * arith(_tac) is now able to generate counterexamples for reals as well.
  5797 
  5798 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5799 
  5800 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5801   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5802 
  5803 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5804   matrix theory to linear programming.
  5805 
  5806 * Unions and Intersections:
  5807   The latex output syntax of UN and INT has been changed
  5808   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5809   i.e. the index formulae has become a subscript.
  5810   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5811 
  5812 * Unions and Intersections over Intervals:
  5813   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5814   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5815   like in normal math, and corresponding versions for < and for intersection.
  5816 
  5817 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5818   lexicographic dictonary ordering has been added as "lexord".
  5819 
  5820 * ML: the legacy theory structures Int and List have been removed. They had
  5821   conflicted with ML Basis Library structures having the same names.
  5822 
  5823 * 'refute' command added to search for (finite) countermodels.  Only works
  5824   for a fragment of HOL.  The installation of an external SAT solver is
  5825   highly recommended.  See "HOL/Refute.thy" for details.
  5826 
  5827 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5828   formulae under an assignment of free variables to random values.
  5829   In contrast to 'refute', it can deal with inductive datatypes,
  5830   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5831   for examples.
  5832 
  5833 
  5834 *** HOLCF ***
  5835 
  5836 * Streams now come with concatenation and are part of the HOLCF image
  5837 
  5838 
  5839 
  5840 New in Isabelle2003 (May 2003)
  5841 ------------------------------
  5842 
  5843 *** General ***
  5844 
  5845 * Provers/simplifier:
  5846 
  5847   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5848     Assumptions are now subject to complete mutual simplification,
  5849     not just from left to right. The simplifier now preserves
  5850     the order of assumptions.
  5851 
  5852     Potential INCOMPATIBILITY:
  5853 
  5854     -- simp sometimes diverges where the old version did
  5855        not, e.g. invoking simp on the goal
  5856 
  5857         [| P (f x); y = x; f x = f y |] ==> Q
  5858 
  5859        now gives rise to the infinite reduction sequence
  5860 
  5861         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5862 
  5863        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5864        kind of problem.
  5865 
  5866     -- Tactics combining classical reasoner and simplification (such as auto)
  5867        are also affected by this change, because many of them rely on
  5868        simp. They may sometimes diverge as well or yield a different numbers
  5869        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5870        in case of problems. Sometimes subsequent calls to the classical
  5871        reasoner will fail because a preceeding call to the simplifier too
  5872        eagerly simplified the goal, e.g. deleted redundant premises.
  5873 
  5874   - The simplifier trace now shows the names of the applied rewrite rules
  5875 
  5876   - You can limit the number of recursive invocations of the simplifier
  5877     during conditional rewriting (where the simplifie tries to solve the
  5878     conditions before applying the rewrite rule):
  5879     ML "simp_depth_limit := n"
  5880     where n is an integer. Thus you can force termination where previously
  5881     the simplifier would diverge.
  5882 
  5883   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5884 
  5885   - No longer aborts on failed congruence proof.  Instead, the
  5886     congruence is ignored.
  5887 
  5888 * Pure: New generic framework for extracting programs from constructive
  5889   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5890   as HOL/Extraction for some case studies.
  5891 
  5892 * Pure: The main goal of the proof state is no longer shown by default, only
  5893 the subgoals. This behaviour is controlled by a new flag.
  5894    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5895 (ML: Proof.show_main_goal).
  5896 
  5897 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5898 rules whose conclusion matches subgoal 1:
  5899       PG menu: Isabelle/Isar -> Show me -> matching rules
  5900 The rules are ordered by how closely they match the subgoal.
  5901 In particular, rules that solve a subgoal outright are displayed first
  5902 (or rather last, the way they are printed).
  5903 (ML: ProofGeneral.print_intros())
  5904 
  5905 * Pure: New flag trace_unify_fail causes unification to print
  5906 diagnostic information (PG: in trace buffer) when it fails. This is
  5907 useful for figuring out why single step proofs like rule, erule or
  5908 assumption failed.
  5909 
  5910 * Pure: Locale specifications now produce predicate definitions
  5911 according to the body of text (covering assumptions modulo local
  5912 definitions); predicate "loc_axioms" covers newly introduced text,
  5913 while "loc" is cumulative wrt. all included locale expressions; the
  5914 latter view is presented only on export into the global theory
  5915 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5916 on the old view without predicates;
  5917 
  5918 * Pure: predefined locales "var" and "struct" are useful for sharing
  5919 parameters (as in CASL, for example); just specify something like
  5920 ``var x + var y + struct M'' as import;
  5921 
  5922 * Pure: improved thms_containing: proper indexing of facts instead of
  5923 raw theorems; check validity of results wrt. current name space;
  5924 include local facts of proof configuration (also covers active
  5925 locales), cover fixed variables in index; may use "_" in term
  5926 specification; an optional limit for the number of printed facts may
  5927 be given (the default is 40);
  5928 
  5929 * Pure: disallow duplicate fact bindings within new-style theory files
  5930 (batch-mode only);
  5931 
  5932 * Provers: improved induct method: assumptions introduced by case
  5933 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5934 the goal statement); "foo" still refers to all facts collectively;
  5935 
  5936 * Provers: the function blast.overloaded has been removed: all constants
  5937 are regarded as potentially overloaded, which improves robustness in exchange
  5938 for slight decrease in efficiency;
  5939 
  5940 * Provers/linorder: New generic prover for transitivity reasoning over
  5941 linear orders.  Note: this prover is not efficient!
  5942 
  5943 * Isar: preview of problems to finish 'show' now produce an error
  5944 rather than just a warning (in interactive mode);
  5945 
  5946 
  5947 *** HOL ***
  5948 
  5949 * arith(_tac)
  5950 
  5951  - Produces a counter example if it cannot prove a goal.
  5952    Note that the counter example may be spurious if the goal is not a formula
  5953    of quantifier-free linear arithmetic.
  5954    In ProofGeneral the counter example appears in the trace buffer.
  5955 
  5956  - Knows about div k and mod k where k is a numeral of type nat or int.
  5957 
  5958  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5959    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5960    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5961 
  5962 * simp's arithmetic capabilities have been enhanced a bit: it now
  5963 takes ~= in premises into account (by performing a case split);
  5964 
  5965 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5966 are distributed over a sum of terms;
  5967 
  5968 * New tactic "trans_tac" and method "trans" instantiate
  5969 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5970 "<=", "<" and "=").
  5971 
  5972 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5973 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5974 
  5975 * 'typedef' command has new option "open" to suppress the set
  5976 definition;
  5977 
  5978 * functions Min and Max on finite sets have been introduced (theory
  5979 Finite_Set);
  5980 
  5981 * attribute [symmetric] now works for relations as well; it turns
  5982 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5983 
  5984 * induct over a !!-quantified statement (say !!x1..xn):
  5985   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5986 
  5987 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5988 %x. None. Warning: empty_def now refers to the previously hidden definition
  5989 of the empty set.
  5990 
  5991 * Algebra: formalization of classical algebra.  Intended as base for
  5992 any algebraic development in Isabelle.  Currently covers group theory
  5993 (up to Sylow's theorem) and ring theory (Universal Property of
  5994 Univariate Polynomials).  Contributions welcome;
  5995 
  5996 * GroupTheory: deleted, since its material has been moved to Algebra;
  5997 
  5998 * Complex: new directory of the complex numbers with numeric constants,
  5999 nonstandard complex numbers, and some complex analysis, standard and
  6000 nonstandard (Jacques Fleuriot);
  6001 
  6002 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6003 
  6004 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6005 Fleuriot);
  6006 
  6007 * Real/HahnBanach: updated and adapted to locales;
  6008 
  6009 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6010 Gray and Kramer);
  6011 
  6012 * UNITY: added the Meier-Sanders theory of progress sets;
  6013 
  6014 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6015 as abstract algorithms, instantiated to the JVM;
  6016 
  6017 * Bali: Java source language formalization. Type system, operational
  6018 semantics, axiomatic semantics. Supported language features:
  6019 classes, interfaces, objects,virtual methods, static methods,
  6020 static/instance fields, arrays, access modifiers, definite
  6021 assignment, exceptions.
  6022 
  6023 
  6024 *** ZF ***
  6025 
  6026 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6027 universe, etc.);
  6028 
  6029 * Main ZF: virtually all theories converted to new-style format;
  6030 
  6031 
  6032 *** ML ***
  6033 
  6034 * Pure: Tactic.prove provides sane interface for internal proofs;
  6035 omits the infamous "standard" operation, so this is more appropriate
  6036 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6037 
  6038 * Pure: improved error reporting of simprocs;
  6039 
  6040 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6041 up simprocs;
  6042 
  6043 
  6044 *** Document preparation ***
  6045 
  6046 * uses \par instead of \\ for line breaks in theory text. This may
  6047 shift some page breaks in large documents. To get the old behaviour
  6048 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6049 
  6050 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6051 other packages
  6052 
  6053 * \<euro> now needs package babel/greek instead of marvosym (which
  6054 broke \Rightarrow)
  6055 
  6056 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6057 textcomp package)
  6058 
  6059 
  6060 
  6061 New in Isabelle2002 (March 2002)
  6062 --------------------------------
  6063 
  6064 *** Document preparation ***
  6065 
  6066 * greatly simplified document preparation setup, including more
  6067 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6068 instructive isatool mkdir; users should basically be able to get
  6069 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6070 users may run a separate document processing stage manually like this:
  6071 "isatool usedir -D output HOL Test && isatool document Test/output";
  6072 
  6073 * theory dependency graph may now be incorporated into documents;
  6074 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6075 with \includegraphics of LaTeX;
  6076 
  6077 * proper spacing of consecutive markup elements, especially text
  6078 blocks after section headings;
  6079 
  6080 * support bold style (for single symbols only), input syntax is like
  6081 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6082 
  6083 * \<bullet> is now output as bold \cdot by default, which looks much
  6084 better in printed text;
  6085 
  6086 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6087 note that these symbols are currently unavailable in Proof General /
  6088 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6089 
  6090 * isatool latex no longer depends on changed TEXINPUTS, instead
  6091 isatool document copies the Isabelle style files to the target
  6092 location;
  6093 
  6094 
  6095 *** Isar ***
  6096 
  6097 * Pure/Provers: improved proof by cases and induction;
  6098   - 'case' command admits impromptu naming of parameters (such as
  6099     "case (Suc n)");
  6100   - 'induct' method divinates rule instantiation from the inductive
  6101     claim; no longer requires excessive ?P bindings for proper
  6102     instantiation of cases;
  6103   - 'induct' method properly enumerates all possibilities of set/type
  6104     rules; as a consequence facts may be also passed through *type*
  6105     rules without further ado;
  6106   - 'induct' method now derives symbolic cases from the *rulified*
  6107     rule (before it used to rulify cases stemming from the internal
  6108     atomized version); this means that the context of a non-atomic
  6109     statement becomes is included in the hypothesis, avoiding the
  6110     slightly cumbersome show "PROP ?case" form;
  6111   - 'induct' may now use elim-style induction rules without chaining
  6112     facts, using ``missing'' premises from the goal state; this allows
  6113     rules stemming from inductive sets to be applied in unstructured
  6114     scripts, while still benefitting from proper handling of non-atomic
  6115     statements; NB: major inductive premises need to be put first, all
  6116     the rest of the goal is passed through the induction;
  6117   - 'induct' proper support for mutual induction involving non-atomic
  6118     rule statements (uses the new concept of simultaneous goals, see
  6119     below);
  6120   - append all possible rule selections, but only use the first
  6121     success (no backtracking);
  6122   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6123   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6124   - added 'print_induct_rules' (covered by help item in recent Proof
  6125     General versions);
  6126   - moved induct/cases attributes to Pure, methods to Provers;
  6127   - generic method setup instantiated for FOL and HOL;
  6128 
  6129 * Pure: support multiple simultaneous goal statements, for example
  6130 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6131 meta-level mechanism, this acts as if several individual goals had
  6132 been stated separately; in particular common proof methods need to be
  6133 repeated in order to cover all claims; note that a single elimination
  6134 step is *not* sufficient to establish the two conjunctions, so this
  6135 fails:
  6136 
  6137   assume "A & B" then have A and B ..   (*".." fails*)
  6138 
  6139 better use "obtain" in situations as above; alternative refer to
  6140 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6141 
  6142 * Pure: proper integration with ``locales''; unlike the original
  6143 version by Florian Kammller, Isar locales package high-level proof
  6144 contexts rather than raw logical ones (e.g. we admit to include
  6145 attributes everywhere); operations on locales include merge and
  6146 rename; support for implicit arguments (``structures''); simultaneous
  6147 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6148 some examples;
  6149 
  6150 * Pure: the following commands have been ``localized'', supporting a
  6151 target locale specification "(in name)": 'lemma', 'theorem',
  6152 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6153 stored both within the locale and at the theory level (exported and
  6154 qualified by the locale name);
  6155 
  6156 * Pure: theory goals may now be specified in ``long'' form, with
  6157 ad-hoc contexts consisting of arbitrary locale elements. for example
  6158 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6159 definitions may be given, too); the result is a meta-level rule with
  6160 the context elements being discharged in the obvious way;
  6161 
  6162 * Pure: new proof command 'using' allows to augment currently used
  6163 facts after a goal statement ('using' is syntactically analogous to
  6164 'apply', but acts on the goal's facts only); this allows chained facts
  6165 to be separated into parts given before and after a claim, as in
  6166 ``from a and b have C using d and e <proof>'';
  6167 
  6168 * Pure: renamed "antecedent" case to "rule_context";
  6169 
  6170 * Pure: new 'judgment' command records explicit information about the
  6171 object-logic embedding (used by several tools internally); no longer
  6172 use hard-wired "Trueprop";
  6173 
  6174 * Pure: added 'corollary' command;
  6175 
  6176 * Pure: fixed 'token_translation' command;
  6177 
  6178 * Pure: removed obsolete 'exported' attribute;
  6179 
  6180 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6181 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6182 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6183 
  6184 * Pure: method 'atomize' presents local goal premises as object-level
  6185 statements (atomic meta-level propositions); setup controlled via
  6186 rewrite rules declarations of 'atomize' attribute; example
  6187 application: 'induct' method with proper rule statements in improper
  6188 proof *scripts*;
  6189 
  6190 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6191 now consider the syntactic context of assumptions, giving a better
  6192 chance to get type-inference of the arguments right (this is
  6193 especially important for locales);
  6194 
  6195 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6196 mode;
  6197 
  6198 * Pure/obtain: the formal conclusion "thesis", being marked as
  6199 ``internal'', may no longer be reference directly in the text;
  6200 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6201 situations;
  6202 
  6203 * Pure: generic 'sym' attribute which declares a rule both as pure
  6204 'elim?' and for the 'symmetric' operation;
  6205 
  6206 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6207 text; the fixed correlation with particular command syntax has been
  6208 discontinued;
  6209 
  6210 * Pure: new method 'rules' is particularly well-suited for proof
  6211 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6212 but often produces more compact proof terms with less detours;
  6213 
  6214 * Pure/Provers/classical: simplified integration with pure rule
  6215 attributes and methods; the classical "intro?/elim?/dest?"
  6216 declarations coincide with the pure ones; the "rule" method no longer
  6217 includes classically swapped intros; "intro" and "elim" methods no
  6218 longer pick rules from the context; also got rid of ML declarations
  6219 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6220 INCOMPATIBILITY;
  6221 
  6222 * Provers/classical: attribute 'swapped' produces classical inversions
  6223 of introduction rules;
  6224 
  6225 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6226 rules instead of full simplifier context; 'iff' attribute handles
  6227 conditional rules;
  6228 
  6229 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6230