NEWS
author wenzelm
Tue Jul 12 14:54:29 2011 +0200 (2011-07-12)
changeset 43774 6dfdb70496fe
parent 43752 0517a69de5d6
child 43815 4f6e2965d821
permissions -rw-r--r--
added Outer_Syntax.quote_string, which is conceptually a bit different from Token.unparse;
     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 * Archimedian_Field.thy:
    64     floor now is defined as parameter of a separate type class floor_ceiling.
    65  
    66 * Finite_Set.thy: more coherent development of fold_set locales:
    67 
    68     locale fun_left_comm ~> locale comp_fun_commute
    69     locale fun_left_comm_idem ~> locale comp_fun_idem
    70     
    71 Both use point-free characterisation; interpretation proofs may need adjustment.
    72 INCOMPATIBILITY.
    73 
    74 * Code generation:
    75   - theory Library/Code_Char_ord provides native ordering of characters
    76     in the target language.
    77     
    78 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    79 
    80 * Nitpick:
    81   - Added "need" and "total_consts" options.
    82   - Reintroduced "show_skolems" option by popular demand.
    83   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    84     INCOMPATIBILITY.
    85 
    86 * Sledgehammer:
    87   - sledgehammer available_provers ~> sledgehammer supported_provers.
    88     INCOMPATIBILITY.
    89   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    90     TPTP problems (TFF).
    91   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
    92     and "max_new_mono_instances" options.
    93   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
    94     Proof General menu item. INCOMPATIBILITY.
    95 
    96 * Metis:
    97   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
    98   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
    99 
   100 * "try":
   101   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   102     options. INCOMPATIBILITY.
   103   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   104     "sledgehammer", "quickcheck", and "nitpick".
   105 
   106 * Quickcheck:
   107   - Added "eval" option to evaluate terms for the found counterexample
   108     (currently only supported by the default (exhaustive) tester)
   109   - Added post-processing of terms to obtain readable counterexamples
   110     (currently only supported by the default (exhaustive) tester)
   111   - New counterexample generator quickcheck[narrowing] enables
   112     narrowing-based testing.
   113     It requires that the Glasgow Haskell compiler is installed and
   114     its location is known to Isabelle with the environment variable
   115     ISABELLE_GHC.
   116 
   117 * Function package: discontinued option "tailrec".
   118 INCOMPATIBILITY. Use partial_function instead.
   119 
   120 * HOL-Probability:
   121   - Caratheodory's extension lemma is now proved for ring_of_sets.
   122   - Infinite products of probability measures are now available.
   123   - Use extended reals instead of positive extended reals.
   124     INCOMPATIBILITY.
   125 
   126 
   127 *** Document preparation ***
   128 
   129 * Discontinued special treatment of hard tabulators, which are better
   130 avoided in the first place.  Implicit tab-width is 1.
   131 
   132 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   133 isar-ref manual.
   134 
   135 * Antiquotation @{value} evaluates the given term and presents its result.
   136 
   137 * Localized \isabellestyle switch can be used within blocks or groups
   138 like this:
   139 
   140   \isabellestyle{it}  %preferred default
   141   {\isabellestylett @{text "typewriter stuff"}}
   142 
   143 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   144 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   145 
   146 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   147 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   148 
   149 
   150 *** ML ***
   151 
   152 * The inner syntax of sort/type/term/prop supports inlined YXML
   153 representations within quoted string tokens.  By encoding logical
   154 entities via Term_XML (in ML or Scala) concrete syntax can be
   155 bypassed, which is particularly useful for producing bits of text
   156 under external program control.
   157 
   158 * Antiquotations for ML and document preparation are managed as theory
   159 data, which requires explicit setup.
   160 
   161 * Isabelle_Process.is_active allows tools to check if the official
   162 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   163 (better known as Proof General).
   164 
   165 * Structure Proof_Context follows standard naming scheme.  Old
   166 ProofContext is still available for some time as legacy alias.
   167 
   168 * Structure Timing provides various operations for timing; supersedes
   169 former start_timing/end_timing etc.
   170 
   171 * Path.print is the official way to show file-system paths to users
   172 (including quotes etc.).
   173 
   174 * Inner syntax: identifiers in parse trees of generic categories
   175 "logic", "aprop", "idt" etc. carry position information (disguised as
   176 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   177 translations that choke on unexpected type constraints.  Positions can
   178 be stripped in ML translations via Syntax.strip_positions /
   179 Syntax.strip_positions_ast, or via the syntax constant
   180 "_strip_positions" within parse trees.  As last resort, positions can
   181 be disabled via the configuration option Syntax.positions, which is
   182 called "syntax_positions" in Isar attribute syntax.
   183 
   184 * Discontinued special status of various ML structures that contribute
   185 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   186 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   187 refer directly to Ast.Constant, Lexicon.is_identifier,
   188 Syntax_Trans.mk_binder_tr etc.
   189 
   190 * Typed print translation: discontinued show_sorts argument, which is
   191 already available via context of "advanced" translation.
   192 
   193 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   194 goal states; body tactic needs to address all subgoals uniformly.
   195 
   196 * Slightly more special eq_list/eq_set, with shortcut involving
   197 pointer equality (assumes that eq relation is reflexive).
   198 
   199 * Classical tactics use proper Proof.context instead of historic types
   200 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   201 operate directly on Proof.context.  Raw type claset retains its use as
   202 snapshot of the classical context, which can be recovered via
   203 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   204 INCOMPATIBILITY, classical tactics and derived proof methods require
   205 proper Proof.context.
   206 
   207 * Scala layer provides JVM method invocation service for static
   208 methods of type (String)String, see Invoke_Scala.method in ML.
   209 For example:
   210 
   211   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   212 
   213 
   214 
   215 New in Isabelle2011 (January 2011)
   216 ----------------------------------
   217 
   218 *** General ***
   219 
   220 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   221 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   222 useful tooltips and hyperlinks produced from its static analysis.  The
   223 bundled component provides an executable Isabelle tool that can be run
   224 like this:
   225 
   226   Isabelle2011/bin/isabelle jedit
   227 
   228 * Significantly improved Isabelle/Isar implementation manual.
   229 
   230 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   231 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   232 while the default heap location within that directory lacks that extra
   233 suffix.  This isolates multiple Isabelle installations from each
   234 other, avoiding problems with old settings in new versions.
   235 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   236 
   237 * Source files are always encoded as UTF-8, instead of old-fashioned
   238 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   239 the following package declarations:
   240 
   241   \usepackage[utf8]{inputenc}
   242   \usepackage{textcomp}
   243 
   244 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   245 a Unicode character is treated as a single symbol, not a sequence of
   246 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   247 contain symbols without further backslash escapes, Unicode can now be
   248 used here as well.  Recall that Symbol.explode in ML provides a
   249 consistent view on symbols, while raw explode (or String.explode)
   250 merely give a byte-oriented representation.
   251 
   252 * Theory loader: source files are primarily located via the master
   253 directory of each theory node (where the .thy file itself resides).
   254 The global load path is still partially available as legacy feature.
   255 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   256 explicit paths, relatively to the theory.
   257 
   258 * Special treatment of ML file names has been discontinued.
   259 Historically, optional extensions .ML or .sml were added on demand --
   260 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   261 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   262 
   263 * Various options that affect pretty printing etc. are now properly
   264 handled within the context via configuration options, instead of
   265 unsynchronized references or print modes.  There are both ML Config.T
   266 entities and Isar declaration attributes to access these.
   267 
   268   ML (Config.T)                 Isar (attribute)
   269 
   270   eta_contract                  eta_contract
   271   show_brackets                 show_brackets
   272   show_sorts                    show_sorts
   273   show_types                    show_types
   274   show_question_marks           show_question_marks
   275   show_consts                   show_consts
   276   show_abbrevs                  show_abbrevs
   277 
   278   Syntax.ast_trace              syntax_ast_trace
   279   Syntax.ast_stat               syntax_ast_stat
   280   Syntax.ambiguity_level        syntax_ambiguity_level
   281 
   282   Goal_Display.goals_limit      goals_limit
   283   Goal_Display.show_main_goal   show_main_goal
   284 
   285   Method.rule_trace             rule_trace
   286 
   287   Thy_Output.display            thy_output_display
   288   Thy_Output.quotes             thy_output_quotes
   289   Thy_Output.indent             thy_output_indent
   290   Thy_Output.source             thy_output_source
   291   Thy_Output.break              thy_output_break
   292 
   293 Note that corresponding "..._default" references in ML may only be
   294 changed globally at the ROOT session setup, but *not* within a theory.
   295 The option "show_abbrevs" supersedes the former print mode
   296 "no_abbrevs" with inverted meaning.
   297 
   298 * More systematic naming of some configuration options.
   299 INCOMPATIBILITY.
   300 
   301   trace_simp  ~>  simp_trace
   302   debug_simp  ~>  simp_debug
   303 
   304 * Support for real valued configuration options, using simplistic
   305 floating-point notation that coincides with the inner syntax for
   306 float_token.
   307 
   308 * Support for real valued preferences (with approximative PGIP type):
   309 front-ends need to accept "pgint" values in float notation.
   310 INCOMPATIBILITY.
   311 
   312 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   313 DejaVu Sans.
   314 
   315 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   316 
   317 
   318 *** Pure ***
   319 
   320 * Command 'type_synonym' (with single argument) replaces somewhat
   321 outdated 'types', which is still available as legacy feature for some
   322 time.
   323 
   324 * Command 'nonterminal' (with 'and' separated list of arguments)
   325 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   326 
   327 * Command 'notepad' replaces former 'example_proof' for
   328 experimentation in Isar without any result.  INCOMPATIBILITY.
   329 
   330 * Locale interpretation commands 'interpret' and 'sublocale' accept
   331 lists of equations to map definitions in a locale to appropriate
   332 entities in the context of the interpretation.  The 'interpretation'
   333 command already provided this functionality.
   334 
   335 * Diagnostic command 'print_dependencies' prints the locale instances
   336 that would be activated if the specified expression was interpreted in
   337 the current context.  Variant "print_dependencies!" assumes a context
   338 without interpretations.
   339 
   340 * Diagnostic command 'print_interps' prints interpretations in proofs
   341 in addition to interpretations in theories.
   342 
   343 * Discontinued obsolete 'global' and 'local' commands to manipulate
   344 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   345 Sign.root_path and Sign.local_path may be applied directly where this
   346 feature is still required for historical reasons.
   347 
   348 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   349 'definition' instead.
   350 
   351 * The "prems" fact, which refers to the accidental collection of
   352 foundational premises in the context, is now explicitly marked as
   353 legacy feature and will be discontinued soon.  Consider using "assms"
   354 of the head statement or reference facts by explicit names.
   355 
   356 * Document antiquotations @{class} and @{type} print classes and type
   357 constructors.
   358 
   359 * Document antiquotation @{file} checks file/directory entries within
   360 the local file system.
   361 
   362 
   363 *** HOL ***
   364 
   365 * Coercive subtyping: functions can be declared as coercions and type
   366 inference will add them as necessary upon input of a term.  Theory
   367 Complex_Main declares real :: nat => real and real :: int => real as
   368 coercions. A coercion function f is declared like this:
   369 
   370   declare [[coercion f]]
   371 
   372 To lift coercions through type constructors (e.g. from nat => real to
   373 nat list => real list), map functions can be declared, e.g.
   374 
   375   declare [[coercion_map map]]
   376 
   377 Currently coercion inference is activated only in theories including
   378 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   379 the configuration option "coercion_enabled", e.g. it can be enabled in
   380 other theories like this:
   381 
   382   declare [[coercion_enabled]]
   383 
   384 * Command 'partial_function' provides basic support for recursive
   385 function definitions over complete partial orders.  Concrete instances
   386 are provided for i) the option type, ii) tail recursion on arbitrary
   387 types, and iii) the heap monad of Imperative_HOL.  See
   388 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   389 for examples.
   390 
   391 * Function package: f.psimps rules are no longer implicitly declared
   392 as [simp].  INCOMPATIBILITY.
   393 
   394 * Datatype package: theorems generated for executable equality (class
   395 "eq") carry proper names and are treated as default code equations.
   396 
   397 * Inductive package: now offers command 'inductive_simps' to
   398 automatically derive instantiated and simplified equations for
   399 inductive predicates, similar to 'inductive_cases'.
   400 
   401 * Command 'enriched_type' allows to register properties of the
   402 functorial structure of types.
   403 
   404 * Improved infrastructure for term evaluation using code generator
   405 techniques, in particular static evaluation conversions.
   406 
   407 * Code generator: Scala (2.8 or higher) has been added to the target
   408 languages.
   409 
   410 * Code generator: globbing constant expressions "*" and "Theory.*"
   411 have been replaced by the more idiomatic "_" and "Theory._".
   412 INCOMPATIBILITY.
   413 
   414 * Code generator: export_code without explicit file declaration prints
   415 to standard output.  INCOMPATIBILITY.
   416 
   417 * Code generator: do not print function definitions for case
   418 combinators any longer.
   419 
   420 * Code generator: simplification with rules determined with
   421 src/Tools/Code/code_simp.ML and method "code_simp".
   422 
   423 * Code generator for records: more idiomatic representation of record
   424 types.  Warning: records are not covered by ancient SML code
   425 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   426 rep_datatype declaration helps to succeed then:
   427 
   428   record 'a foo = ...
   429   ...
   430   rep_datatype foo_ext ...
   431 
   432 * Records: logical foundation type for records does not carry a
   433 '_type' suffix any longer (obsolete due to authentic syntax).
   434 INCOMPATIBILITY.
   435 
   436 * Quickcheck now by default uses exhaustive testing instead of random
   437 testing.  Random testing can be invoked by "quickcheck [random]",
   438 exhaustive testing by "quickcheck [exhaustive]".
   439 
   440 * Quickcheck instantiates polymorphic types with small finite
   441 datatypes by default. This enables a simple execution mechanism to
   442 handle quantifiers and function equality over the finite datatypes.
   443 
   444 * Quickcheck random generator has been renamed from "code" to
   445 "random".  INCOMPATIBILITY.
   446 
   447 * Quickcheck now has a configurable time limit which is set to 30
   448 seconds by default. This can be changed by adding [timeout = n] to the
   449 quickcheck command. The time limit for Auto Quickcheck is still set
   450 independently.
   451 
   452 * Quickcheck in locales considers interpretations of that locale for
   453 counter example search.
   454 
   455 * Sledgehammer:
   456   - Added "smt" and "remote_smt" provers based on the "smt" proof
   457     method. See the Sledgehammer manual for details ("isabelle doc
   458     sledgehammer").
   459   - Renamed commands:
   460     sledgehammer atp_info ~> sledgehammer running_provers
   461     sledgehammer atp_kill ~> sledgehammer kill_provers
   462     sledgehammer available_atps ~> sledgehammer available_provers
   463     INCOMPATIBILITY.
   464   - Renamed options:
   465     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   466     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   467     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   468     (and "ms" and "min" are no longer supported)
   469     INCOMPATIBILITY.
   470 
   471 * Nitpick:
   472   - Renamed options:
   473     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   474     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   475     INCOMPATIBILITY.
   476   - Added support for partial quotient types.
   477   - Added local versions of the "Nitpick.register_xxx" functions.
   478   - Added "whack" option.
   479   - Allow registration of quotient types as codatatypes.
   480   - Improved "merge_type_vars" option to merge more types.
   481   - Removed unsound "fast_descrs" option.
   482   - Added custom symmetry breaking for datatypes, making it possible to reach
   483     higher cardinalities.
   484   - Prevent the expansion of too large definitions.
   485 
   486 * Proof methods "metis" and "meson" now have configuration options
   487 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   488 to diagnose these tools. E.g.
   489 
   490     using [[metis_trace = true]]
   491 
   492 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   493 manually as command 'solve_direct'.
   494 
   495 * The default SMT solver Z3 must be enabled explicitly (due to
   496 licensing issues) by setting the environment variable
   497 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   498 commercial applications, the SMT solver CVC3 is provided as fall-back;
   499 changing the SMT solver is done via the configuration option
   500 "smt_solver".
   501 
   502 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   503 i.e. "remote_cvc3" and "remote_z3".
   504 
   505 * Added basic SMT support for datatypes, records, and typedefs using
   506 the oracle mode (no proofs).  Direct support of pairs has been dropped
   507 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   508 support for a similar behavior).  Minor INCOMPATIBILITY.
   509 
   510 * Changed SMT configuration options:
   511   - Renamed:
   512     z3_proofs ~> smt_oracle (with inverted meaning)
   513     z3_trace_assms ~> smt_trace_used_facts
   514     INCOMPATIBILITY.
   515   - Added:
   516     smt_verbose
   517     smt_random_seed
   518     smt_datatypes
   519     smt_infer_triggers
   520     smt_monomorph_limit
   521     cvc3_options
   522     remote_cvc3_options
   523     remote_z3_options
   524     yices_options
   525 
   526 * Boogie output files (.b2i files) need to be declared in the theory
   527 header.
   528 
   529 * Simplification procedure "list_to_set_comprehension" rewrites list
   530 comprehensions applied to List.set to set comprehensions.  Occasional
   531 INCOMPATIBILITY, may be deactivated like this:
   532 
   533   declare [[simproc del: list_to_set_comprehension]]
   534 
   535 * Removed old version of primrec package.  INCOMPATIBILITY.
   536 
   537 * Removed simplifier congruence rule of "prod_case", as has for long
   538 been the case with "split".  INCOMPATIBILITY.
   539 
   540 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   541 
   542 * Removed [split_format ... and ... and ...] version of
   543 [split_format].  Potential INCOMPATIBILITY.
   544 
   545 * Predicate "sorted" now defined inductively, with nice induction
   546 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   547 
   548 * Constant "contents" renamed to "the_elem", to free the generic name
   549 contents for other uses.  INCOMPATIBILITY.
   550 
   551 * Renamed class eq and constant eq (for code generation) to class
   552 equal and constant equal, plus renaming of related facts and various
   553 tuning.  INCOMPATIBILITY.
   554 
   555 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   556 
   557 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   558 INCOMPATIBILITY.
   559 
   560 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   561 avoid confusion with finite sets.  INCOMPATIBILITY.
   562 
   563 * Abandoned locales equiv, congruent and congruent2 for equivalence
   564 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   565 for congruent(2)).
   566 
   567 * Some previously unqualified names have been qualified:
   568 
   569   types
   570     bool ~> HOL.bool
   571     nat ~> Nat.nat
   572 
   573   constants
   574     Trueprop ~> HOL.Trueprop
   575     True ~> HOL.True
   576     False ~> HOL.False
   577     op & ~> HOL.conj
   578     op | ~> HOL.disj
   579     op --> ~> HOL.implies
   580     op = ~> HOL.eq
   581     Not ~> HOL.Not
   582     The ~> HOL.The
   583     All ~> HOL.All
   584     Ex ~> HOL.Ex
   585     Ex1 ~> HOL.Ex1
   586     Let ~> HOL.Let
   587     If ~> HOL.If
   588     Ball ~> Set.Ball
   589     Bex ~> Set.Bex
   590     Suc ~> Nat.Suc
   591     Pair ~> Product_Type.Pair
   592     fst ~> Product_Type.fst
   593     snd ~> Product_Type.snd
   594     curry ~> Product_Type.curry
   595     op : ~> Set.member
   596     Collect ~> Set.Collect
   597 
   598 INCOMPATIBILITY.
   599 
   600 * More canonical naming convention for some fundamental definitions:
   601 
   602     bot_bool_eq ~> bot_bool_def
   603     top_bool_eq ~> top_bool_def
   604     inf_bool_eq ~> inf_bool_def
   605     sup_bool_eq ~> sup_bool_def
   606     bot_fun_eq  ~> bot_fun_def
   607     top_fun_eq  ~> top_fun_def
   608     inf_fun_eq  ~> inf_fun_def
   609     sup_fun_eq  ~> sup_fun_def
   610 
   611 INCOMPATIBILITY.
   612 
   613 * More stylized fact names:
   614 
   615   expand_fun_eq ~> fun_eq_iff
   616   expand_set_eq ~> set_eq_iff
   617   set_ext       ~> set_eqI
   618   nat_number    ~> eval_nat_numeral
   619 
   620 INCOMPATIBILITY.
   621 
   622 * Refactoring of code-generation specific operations in theory List:
   623 
   624   constants
   625     null ~> List.null
   626 
   627   facts
   628     mem_iff ~> member_def
   629     null_empty ~> null_def
   630 
   631 INCOMPATIBILITY.  Note that these were not supposed to be used
   632 regularly unless for striking reasons; their main purpose was code
   633 generation.
   634 
   635 Various operations from the Haskell prelude are used for generating
   636 Haskell code.
   637 
   638 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   639 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   640 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   641 
   642 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   643 "*" and "+" respectively.  INCOMPATIBILITY.
   644 
   645 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   646 "Sum_Type.Plus" instead.
   647 
   648 * Constant "split" has been merged with constant "prod_case"; names of
   649 ML functions, facts etc. involving split have been retained so far,
   650 though.  INCOMPATIBILITY.
   651 
   652 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   653 instead.  INCOMPATIBILITY.
   654 
   655 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   656 INCOMPATIBILITY.
   657 
   658 * Former theory Library/Enum is now part of the HOL-Main image.
   659 INCOMPATIBILITY: all constants of the Enum theory now have to be
   660 referred to by its qualified name.
   661 
   662   enum    ~>  Enum.enum
   663   nlists  ~>  Enum.nlists
   664   product ~>  Enum.product
   665 
   666 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   667 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   668 INCOMPATIBILITY.
   669 
   670 * Theory Library/SetsAndFunctions has been split into
   671 Library/Function_Algebras and Library/Set_Algebras; canonical names
   672 for instance definitions for functions; various improvements.
   673 INCOMPATIBILITY.
   674 
   675 * Theory Library/Multiset provides stable quicksort implementation of
   676 sort_key.
   677 
   678 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   679 INCOMPATIBILITY.
   680 
   681 * Session Multivariate_Analysis: introduced a type class for euclidean
   682 space.  Most theorems are now stated in terms of euclidean spaces
   683 instead of finite cartesian products.
   684 
   685   types
   686     real ^ 'n ~>  'a::real_vector
   687               ~>  'a::euclidean_space
   688               ~>  'a::ordered_euclidean_space
   689         (depends on your needs)
   690 
   691   constants
   692      _ $ _        ~> _ $$ _
   693      \<chi> x. _  ~> \<chi>\<chi> x. _
   694      CARD('n)     ~> DIM('a)
   695 
   696 Also note that the indices are now natural numbers and not from some
   697 finite type. Finite cartesian products of euclidean spaces, products
   698 of euclidean spaces the real and complex numbers are instantiated to
   699 be euclidean_spaces.  INCOMPATIBILITY.
   700 
   701 * Session Probability: introduced pextreal as positive extended real
   702 numbers.  Use pextreal as value for measures.  Introduce the
   703 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   704 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   705 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   706 
   707 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   708 INCOMPATIBILITY.
   709 
   710 * Session SPARK (with image HOL-SPARK) provides commands to load and
   711 prove verification conditions generated by the SPARK Ada program
   712 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   713 
   714 
   715 *** HOL-Algebra ***
   716 
   717 * Theorems for additive ring operations (locale abelian_monoid and
   718 descendants) are generated by interpretation from their multiplicative
   719 counterparts.  Names (in particular theorem names) have the mandatory
   720 qualifier 'add'.  Previous theorem names are redeclared for
   721 compatibility.
   722 
   723 * Structure "int_ring" is now an abbreviation (previously a
   724 definition).  This fits more natural with advanced interpretations.
   725 
   726 
   727 *** HOLCF ***
   728 
   729 * The domain package now runs in definitional mode by default: The
   730 former command 'new_domain' is now called 'domain'.  To use the domain
   731 package in its original axiomatic mode, use 'domain (unsafe)'.
   732 INCOMPATIBILITY.
   733 
   734 * The new class "domain" is now the default sort.  Class "predomain"
   735 is an unpointed version of "domain". Theories can be updated by
   736 replacing sort annotations as shown below.  INCOMPATIBILITY.
   737 
   738   'a::type ~> 'a::countable
   739   'a::cpo  ~> 'a::predomain
   740   'a::pcpo ~> 'a::domain
   741 
   742 * The old type class "rep" has been superseded by class "domain".
   743 Accordingly, users of the definitional package must remove any
   744 "default_sort rep" declarations.  INCOMPATIBILITY.
   745 
   746 * The domain package (definitional mode) now supports unpointed
   747 predomain argument types, as long as they are marked 'lazy'. (Strict
   748 arguments must be in class "domain".) For example, the following
   749 domain definition now works:
   750 
   751   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   752 
   753 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   754 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   755 'a option, and 'a list.  Additionally, it configures fixrec and the
   756 domain package to work with these types.  For example:
   757 
   758   fixrec isInl :: "('a + 'b) u -> tr"
   759     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   760 
   761   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   762 
   763 * The "(permissive)" option of fixrec has been replaced with a
   764 per-equation "(unchecked)" option. See
   765 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   766 
   767 * The "bifinite" class no longer fixes a constant "approx"; the class
   768 now just asserts that such a function exists.  INCOMPATIBILITY.
   769 
   770 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   771 defines an embedding of type 'a defl into udom by default; instances
   772 of "bifinite" and "domain" classes are available in
   773 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   774 
   775 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   776 
   777 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   778 
   779 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   780 
   781 * The function "cprod_map" has been renamed to "prod_map".
   782 INCOMPATIBILITY.
   783 
   784 * The monadic bind operator on each powerdomain has new binder syntax
   785 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   786 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   787 
   788 * The infix syntax for binary union on each powerdomain has changed
   789 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   790 syntax.  INCOMPATIBILITY.
   791 
   792 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   793 still supported as an input translation.
   794 
   795 * Renamed some theorems (the original names are also still available).
   796 
   797   expand_fun_below   ~> fun_below_iff
   798   below_fun_ext      ~> fun_belowI
   799   expand_cfun_eq     ~> cfun_eq_iff
   800   ext_cfun           ~> cfun_eqI
   801   expand_cfun_below  ~> cfun_below_iff
   802   below_cfun_ext     ~> cfun_belowI
   803   cont2cont_Rep_CFun ~> cont2cont_APP
   804 
   805 * The Abs and Rep functions for various types have changed names.
   806 Related theorem names have also changed to match. INCOMPATIBILITY.
   807 
   808   Rep_CFun  ~> Rep_cfun
   809   Abs_CFun  ~> Abs_cfun
   810   Rep_Sprod ~> Rep_sprod
   811   Abs_Sprod ~> Abs_sprod
   812   Rep_Ssum  ~> Rep_ssum
   813   Abs_Ssum  ~> Abs_ssum
   814 
   815 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   816 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   817 
   818 * Various changes to bisimulation/coinduction with domain package:
   819 
   820   - Definitions of "bisim" constants no longer mention definedness.
   821   - With mutual recursion, "bisim" predicate is now curried.
   822   - With mutual recursion, each type gets a separate coind theorem.
   823   - Variable names in bisim_def and coinduct rules have changed.
   824 
   825 INCOMPATIBILITY.
   826 
   827 * Case combinators generated by the domain package for type "foo" are
   828 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   829 
   830 * Several theorems have been renamed to more accurately reflect the
   831 names of constants and types involved.  INCOMPATIBILITY.
   832 
   833   thelub_const    ~> lub_const
   834   lub_const       ~> is_lub_const
   835   thelubI         ~> lub_eqI
   836   is_lub_lub      ~> is_lubD2
   837   lubI            ~> is_lub_lub
   838   unique_lub      ~> is_lub_unique
   839   is_ub_lub       ~> is_lub_rangeD1
   840   lub_bin_chain   ~> is_lub_bin_chain
   841   lub_fun         ~> is_lub_fun
   842   thelub_fun      ~> lub_fun
   843   thelub_cfun     ~> lub_cfun
   844   thelub_Pair     ~> lub_Pair
   845   lub_cprod       ~> is_lub_prod
   846   thelub_cprod    ~> lub_prod
   847   minimal_cprod   ~> minimal_prod
   848   inst_cprod_pcpo ~> inst_prod_pcpo
   849   UU_I            ~> bottomI
   850   compact_UU      ~> compact_bottom
   851   deflation_UU    ~> deflation_bottom
   852   finite_deflation_UU ~> finite_deflation_bottom
   853 
   854 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   855 
   856   sq_ord_less_eq_trans ~> below_eq_trans
   857   sq_ord_eq_less_trans ~> eq_below_trans
   858   refl_less            ~> below_refl
   859   trans_less           ~> below_trans
   860   antisym_less         ~> below_antisym
   861   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   862   box_less             ~> box_below
   863   rev_trans_less       ~> rev_below_trans
   864   not_less2not_eq      ~> not_below2not_eq
   865   less_UU_iff          ~> below_UU_iff
   866   flat_less_iff        ~> flat_below_iff
   867   adm_less             ~> adm_below
   868   adm_not_less         ~> adm_not_below
   869   adm_compact_not_less ~> adm_compact_not_below
   870   less_fun_def         ~> below_fun_def
   871   expand_fun_less      ~> fun_below_iff
   872   less_fun_ext         ~> fun_belowI
   873   less_discr_def       ~> below_discr_def
   874   discr_less_eq        ~> discr_below_eq
   875   less_unit_def        ~> below_unit_def
   876   less_cprod_def       ~> below_prod_def
   877   prod_lessI           ~> prod_belowI
   878   Pair_less_iff        ~> Pair_below_iff
   879   fst_less_iff         ~> fst_below_iff
   880   snd_less_iff         ~> snd_below_iff
   881   expand_cfun_less     ~> cfun_below_iff
   882   less_cfun_ext        ~> cfun_belowI
   883   injection_less       ~> injection_below
   884   less_up_def          ~> below_up_def
   885   not_Iup_less         ~> not_Iup_below
   886   Iup_less             ~> Iup_below
   887   up_less              ~> up_below
   888   Def_inject_less_eq   ~> Def_below_Def
   889   Def_less_is_eq       ~> Def_below_iff
   890   spair_less_iff       ~> spair_below_iff
   891   less_sprod           ~> below_sprod
   892   spair_less           ~> spair_below
   893   sfst_less_iff        ~> sfst_below_iff
   894   ssnd_less_iff        ~> ssnd_below_iff
   895   fix_least_less       ~> fix_least_below
   896   dist_less_one        ~> dist_below_one
   897   less_ONE             ~> below_ONE
   898   ONE_less_iff         ~> ONE_below_iff
   899   less_sinlD           ~> below_sinlD
   900   less_sinrD           ~> below_sinrD
   901 
   902 
   903 *** FOL and ZF ***
   904 
   905 * All constant names are now qualified internally and use proper
   906 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   907 
   908 
   909 *** ML ***
   910 
   911 * Antiquotation @{assert} inlines a function bool -> unit that raises
   912 Fail if the argument is false.  Due to inlining the source position of
   913 failed assertions is included in the error output.
   914 
   915 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   916 text is in practice always evaluated with a stable theory checkpoint.
   917 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   918 
   919 * Antiquotation @{theory A} refers to theory A from the ancestry of
   920 the current context, not any accidental theory loader state as before.
   921 Potential INCOMPATIBILITY, subtle change in semantics.
   922 
   923 * Syntax.pretty_priority (default 0) configures the required priority
   924 of pretty-printed output and thus affects insertion of parentheses.
   925 
   926 * Syntax.default_root (default "any") configures the inner syntax
   927 category (nonterminal symbol) for parsing of terms.
   928 
   929 * Former exception Library.UnequalLengths now coincides with
   930 ListPair.UnequalLengths.
   931 
   932 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   933 main functionality is provided by structure Simplifier.
   934 
   935 * Renamed raw "explode" function to "raw_explode" to emphasize its
   936 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   937 almost all situations.
   938 
   939 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   940 See implementation manual for further details on exceptions in
   941 Isabelle/ML.
   942 
   943 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   944 meaning.
   945 
   946 * Renamed structure PureThy to Pure_Thy and moved most of its
   947 operations to structure Global_Theory, to emphasize that this is
   948 rarely-used global-only stuff.
   949 
   950 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   951 instead (or tracing for high-volume output).
   952 
   953 * Configuration option show_question_marks only affects regular pretty
   954 printing of types and terms, not raw Term.string_of_vname.
   955 
   956 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   957 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   958 @{thms} for most purposes.
   959 
   960 * ML structure Unsynchronized is never opened, not even in Isar
   961 interaction mode as before.  Old Unsynchronized.set etc. have been
   962 discontinued -- use plain := instead.  This should be *rare* anyway,
   963 since modern tools always work via official context data, notably
   964 configuration options.
   965 
   966 * Parallel and asynchronous execution requires special care concerning
   967 interrupts.  Structure Exn provides some convenience functions that
   968 avoid working directly with raw Interrupt.  User code must not absorb
   969 interrupts -- intermediate handling (for cleanup etc.) needs to be
   970 followed by re-raising of the original exception.  Another common
   971 source of mistakes are "handle _" patterns, which make the meaning of
   972 the program subject to physical effects of the environment.
   973 
   974 
   975 
   976 New in Isabelle2009-2 (June 2010)
   977 ---------------------------------
   978 
   979 *** General ***
   980 
   981 * Authentic syntax for *all* logical entities (type classes, type
   982 constructors, term constants): provides simple and robust
   983 correspondence between formal entities and concrete syntax.  Within
   984 the parse tree / AST representations, "constants" are decorated by
   985 their category (class, type, const) and spelled out explicitly with
   986 their full internal name.
   987 
   988 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   989 and translations (translation rules and translation functions in ML).
   990 Some hints on upgrading:
   991 
   992   - Many existing uses of 'syntax' and 'translations' can be replaced
   993     by more modern 'type_notation', 'notation' and 'abbreviation',
   994     which are independent of this issue.
   995 
   996   - 'translations' require markup within the AST; the term syntax
   997     provides the following special forms:
   998 
   999       CONST c   -- produces syntax version of constant c from context
  1000       XCONST c  -- literally c, checked as constant from context
  1001       c         -- literally c, if declared by 'syntax'
  1002 
  1003     Plain identifiers are treated as AST variables -- occasionally the
  1004     system indicates accidental variables via the error "rhs contains
  1005     extra variables".
  1006 
  1007     Type classes and type constructors are marked according to their
  1008     concrete syntax.  Some old translations rules need to be written
  1009     for the "type" category, using type constructor application
  1010     instead of pseudo-term application of the default category
  1011     "logic".
  1012 
  1013   - 'parse_translation' etc. in ML may use the following
  1014     antiquotations:
  1015 
  1016       @{class_syntax c}   -- type class c within parse tree / AST
  1017       @{term_syntax c}    -- type constructor c within parse tree / AST
  1018       @{const_syntax c}   -- ML version of "CONST c" above
  1019       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1020 
  1021   - Literal types within 'typed_print_translations', i.e. those *not*
  1022     represented as pseudo-terms are represented verbatim.  Use @{class
  1023     c} or @{type_name c} here instead of the above syntax
  1024     antiquotations.
  1025 
  1026 Note that old non-authentic syntax was based on unqualified base
  1027 names, so all of the above "constant" names would coincide.  Recall
  1028 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1029 diagnose syntax problems.
  1030 
  1031 * Type constructors admit general mixfix syntax, not just infix.
  1032 
  1033 * Concrete syntax may be attached to local entities without a proof
  1034 body, too.  This works via regular mixfix annotations for 'fix',
  1035 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1036 similar to the 'notation' command in theory specifications.
  1037 
  1038 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1039 need to specify constant name and syntax separately.  Internal ML
  1040 datatype constructors have been renamed from InfixName to Infix etc.
  1041 Minor INCOMPATIBILITY.
  1042 
  1043 * Schematic theorem statements need to be explicitly markup as such,
  1044 via commands 'schematic_lemma', 'schematic_theorem',
  1045 'schematic_corollary'.  Thus the relevance of the proof is made
  1046 syntactically clear, which impacts performance in a parallel or
  1047 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1048 
  1049 * Use of cumulative prems via "!" in some proof methods has been
  1050 discontinued (old legacy feature).
  1051 
  1052 * References 'trace_simp' and 'debug_simp' have been replaced by
  1053 configuration options stored in the context. Enabling tracing (the
  1054 case of debugging is similar) in proofs works via
  1055 
  1056   using [[trace_simp = true]]
  1057 
  1058 Tracing is then active for all invocations of the simplifier in
  1059 subsequent goal refinement steps. Tracing may also still be enabled or
  1060 disabled via the ProofGeneral settings menu.
  1061 
  1062 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1063 'hide_fact' replace the former 'hide' KIND command.  Minor
  1064 INCOMPATIBILITY.
  1065 
  1066 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1067 more efficient than combinations with -q1 or -q2.
  1068 
  1069 
  1070 *** Pure ***
  1071 
  1072 * Proofterms record type-class reasoning explicitly, using the
  1073 "unconstrain" operation internally.  This eliminates all sort
  1074 constraints from a theorem and proof, introducing explicit
  1075 OFCLASS-premises.  On the proof term level, this operation is
  1076 automatically applied at theorem boundaries, such that closed proofs
  1077 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1078 inspect proof terms.
  1079 
  1080 * Local theory specifications may depend on extra type variables that
  1081 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1082 are added internally.  For example:
  1083 
  1084   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1085 
  1086 * Predicates of locales introduced by classes carry a mandatory
  1087 "class" prefix.  INCOMPATIBILITY.
  1088 
  1089 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1090 
  1091 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1092 'class' instead.
  1093 
  1094 * Command 'code_reflect' allows to incorporate generated ML code into
  1095 runtime environment; replaces immature code_datatype antiquotation.
  1096 INCOMPATIBILITY.
  1097 
  1098 * Code generator: simple concept for abstract datatypes obeying
  1099 invariants.
  1100 
  1101 * Code generator: details of internal data cache have no impact on the
  1102 user space functionality any longer.
  1103 
  1104 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1105 subgoals.  This is more appropriate for interpretations with 'where'.
  1106 INCOMPATIBILITY.
  1107 
  1108 * Command 'example_proof' opens an empty proof body.  This allows to
  1109 experiment with Isar, without producing any persistent result.
  1110 
  1111 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1112 within a local theory context, with explicit checking of the
  1113 constructors involved (in contrast to the raw 'syntax' versions).
  1114 
  1115 * Commands 'types' and 'typedecl' now work within a local theory
  1116 context -- without introducing dependencies on parameters or
  1117 assumptions, which is not possible in Isabelle/Pure.
  1118 
  1119 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1120 within a local theory context.  Minor INCOMPATIBILITY.
  1121 
  1122 
  1123 *** HOL ***
  1124 
  1125 * Command 'typedef' now works within a local theory context -- without
  1126 introducing dependencies on parameters or assumptions, which is not
  1127 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1128 contain multiple interpretations of local typedefs (with different
  1129 non-emptiness proofs), even in a global theory context.
  1130 
  1131 * New package for quotient types.  Commands 'quotient_type' and
  1132 'quotient_definition' may be used for defining types and constants by
  1133 quotient constructions.  An example is the type of integers created by
  1134 quotienting pairs of natural numbers:
  1135 
  1136   fun
  1137     intrel :: "(nat * nat) => (nat * nat) => bool"
  1138   where
  1139     "intrel (x, y) (u, v) = (x + v = u + y)"
  1140 
  1141   quotient_type int = "nat * nat" / intrel
  1142     by (auto simp add: equivp_def expand_fun_eq)
  1143 
  1144   quotient_definition
  1145     "0::int" is "(0::nat, 0::nat)"
  1146 
  1147 The method "lifting" can be used to lift of theorems from the
  1148 underlying "raw" type to the quotient type.  The example
  1149 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1150 construction and provides a reasoning infrastructure for finite sets.
  1151 
  1152 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1153 clash with new theory Quotient in Main HOL.
  1154 
  1155 * Moved the SMT binding into the main HOL session, eliminating
  1156 separate HOL-SMT session.
  1157 
  1158 * List membership infix mem operation is only an input abbreviation.
  1159 INCOMPATIBILITY.
  1160 
  1161 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1162 for future developements; former Library/Word.thy is still present in
  1163 the AFP entry RSAPPS.
  1164 
  1165 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1166 longer shadowed.  INCOMPATIBILITY.
  1167 
  1168 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1169 INCOMPATIBILITY.
  1170 
  1171 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1172 INCOMPATIBILITY.
  1173 
  1174 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1175 instead.  INCOMPATIBILITY.
  1176 
  1177 * Dropped several real-specific versions of lemmas about floor and
  1178 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1179 instead.  INCOMPATIBILITY.
  1180 
  1181   floor_number_of_eq         ~> floor_number_of
  1182   le_floor_eq_number_of      ~> number_of_le_floor
  1183   le_floor_eq_zero           ~> zero_le_floor
  1184   le_floor_eq_one            ~> one_le_floor
  1185   floor_less_eq_number_of    ~> floor_less_number_of
  1186   floor_less_eq_zero         ~> floor_less_zero
  1187   floor_less_eq_one          ~> floor_less_one
  1188   less_floor_eq_number_of    ~> number_of_less_floor
  1189   less_floor_eq_zero         ~> zero_less_floor
  1190   less_floor_eq_one          ~> one_less_floor
  1191   floor_le_eq_number_of      ~> floor_le_number_of
  1192   floor_le_eq_zero           ~> floor_le_zero
  1193   floor_le_eq_one            ~> floor_le_one
  1194   floor_subtract_number_of   ~> floor_diff_number_of
  1195   floor_subtract_one         ~> floor_diff_one
  1196   ceiling_number_of_eq       ~> ceiling_number_of
  1197   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1198   ceiling_le_zero_eq         ~> ceiling_le_zero
  1199   ceiling_le_eq_one          ~> ceiling_le_one
  1200   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1201   less_ceiling_eq_zero       ~> zero_less_ceiling
  1202   less_ceiling_eq_one        ~> one_less_ceiling
  1203   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1204   ceiling_less_eq_zero       ~> ceiling_less_zero
  1205   ceiling_less_eq_one        ~> ceiling_less_one
  1206   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1207   le_ceiling_eq_zero         ~> zero_le_ceiling
  1208   le_ceiling_eq_one          ~> one_le_ceiling
  1209   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1210   ceiling_subtract_one       ~> ceiling_diff_one
  1211 
  1212 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1213 application of the various fold combinators on finite sets.
  1214 
  1215 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1216 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1217 implementation.  INCOMPATIBILTY.
  1218 
  1219 * Theory Library/Coinductive_List has been removed -- superseded by
  1220 AFP/thys/Coinductive.
  1221 
  1222 * Theory PReal, including the type "preal" and related operations, has
  1223 been removed.  INCOMPATIBILITY.
  1224 
  1225 * Real: new development using Cauchy Sequences.
  1226 
  1227 * Split off theory "Big_Operators" containing setsum, setprod,
  1228 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1229 
  1230 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1231 "Int" etc.  INCOMPATIBILITY.
  1232 
  1233 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1234 
  1235 * New set of rules "ac_simps" provides combined assoc / commute
  1236 rewrites for all interpretations of the appropriate generic locales.
  1237 
  1238 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1239 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1240 appropriate and more consistent names suitable for name prefixes
  1241 within the HOL theories.  INCOMPATIBILITY.
  1242 
  1243 * Some generic constants have been put to appropriate theories:
  1244   - less_eq, less: Orderings
  1245   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1246   - inverse, divide: Rings
  1247 INCOMPATIBILITY.
  1248 
  1249 * More consistent naming of type classes involving orderings (and
  1250 lattices):
  1251 
  1252     lower_semilattice                   ~> semilattice_inf
  1253     upper_semilattice                   ~> semilattice_sup
  1254 
  1255     dense_linear_order                  ~> dense_linorder
  1256 
  1257     pordered_ab_group_add               ~> ordered_ab_group_add
  1258     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1259     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1260     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1261     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1262     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1263     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1264     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1265     pordered_comm_ring                  ~> ordered_comm_ring
  1266     pordered_comm_semiring              ~> ordered_comm_semiring
  1267     pordered_ring                       ~> ordered_ring
  1268     pordered_ring_abs                   ~> ordered_ring_abs
  1269     pordered_semiring                   ~> ordered_semiring
  1270 
  1271     ordered_ab_group_add                ~> linordered_ab_group_add
  1272     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1273     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1274     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1275     ordered_field                       ~> linordered_field
  1276     ordered_field_no_lb                 ~> linordered_field_no_lb
  1277     ordered_field_no_ub                 ~> linordered_field_no_ub
  1278     ordered_field_dense_linear_order    ~> dense_linordered_field
  1279     ordered_idom                        ~> linordered_idom
  1280     ordered_ring                        ~> linordered_ring
  1281     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1282     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1283     ordered_ring_strict                 ~> linordered_ring_strict
  1284     ordered_semidom                     ~> linordered_semidom
  1285     ordered_semiring                    ~> linordered_semiring
  1286     ordered_semiring_1                  ~> linordered_semiring_1
  1287     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1288     ordered_semiring_strict             ~> linordered_semiring_strict
  1289 
  1290   The following slightly odd type classes have been moved to a
  1291   separate theory Library/Lattice_Algebras:
  1292 
  1293     lordered_ab_group_add               ~> lattice_ab_group_add
  1294     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1295     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1296     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1297     lordered_ring                       ~> lattice_ring
  1298 
  1299 INCOMPATIBILITY.
  1300 
  1301 * Refined field classes:
  1302   - classes division_ring_inverse_zero, field_inverse_zero,
  1303     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1304     subsumes former division_by_zero class;
  1305   - numerous lemmas have been ported from field to division_ring.
  1306 INCOMPATIBILITY.
  1307 
  1308 * Refined algebra theorem collections:
  1309   - dropped theorem group group_simps, use algebra_simps instead;
  1310   - dropped theorem group ring_simps, use field_simps instead;
  1311   - proper theorem collection field_simps subsumes former theorem
  1312     groups field_eq_simps and field_simps;
  1313   - dropped lemma eq_minus_self_iff which is a duplicate for
  1314     equal_neg_zero.
  1315 INCOMPATIBILITY.
  1316 
  1317 * Theory Finite_Set and List: some lemmas have been generalized from
  1318 sets to lattices:
  1319 
  1320   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1321   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1322   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1323   union_Union_fold_union        ~> sup_Sup_fold_sup
  1324   Inter_fold_inter              ~> Inf_fold_inf
  1325   Union_fold_union              ~> Sup_fold_sup
  1326   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1327   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1328   INTER_fold_inter              ~> INFI_fold_inf
  1329   UNION_fold_union              ~> SUPR_fold_sup
  1330 
  1331 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1332 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1333 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1334 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1335 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1336 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1337 
  1338 * Reorganized theory Multiset: swapped notation of pointwise and
  1339 multiset order:
  1340 
  1341   - pointwise ordering is instance of class order with standard syntax
  1342     <= and <;
  1343   - multiset ordering has syntax <=# and <#; partial order properties
  1344     are provided by means of interpretation with prefix
  1345     multiset_order;
  1346   - less duplication, less historical organization of sections,
  1347     conversion from associations lists to multisets, rudimentary code
  1348     generation;
  1349   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1350     if needed.
  1351 
  1352 Renamed:
  1353 
  1354   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1355   multi_count_ext  ~>  multiset_ext
  1356   diff_union_inverse2  ~>  diff_union_cancelR
  1357 
  1358 INCOMPATIBILITY.
  1359 
  1360 * Theory Permutation: replaced local "remove" by List.remove1.
  1361 
  1362 * Code generation: ML and OCaml code is decorated with signatures.
  1363 
  1364 * Theory List: added transpose.
  1365 
  1366 * Library/Nat_Bijection.thy is a collection of bijective functions
  1367 between nat and other types, which supersedes the older libraries
  1368 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1369 
  1370   Constants:
  1371   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1372   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1373   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1374   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1375   Countable.pair_encode           ~> prod_encode
  1376   NatIso.prod2nat                 ~> prod_encode
  1377   NatIso.nat2prod                 ~> prod_decode
  1378   NatIso.sum2nat                  ~> sum_encode
  1379   NatIso.nat2sum                  ~> sum_decode
  1380   NatIso.list2nat                 ~> list_encode
  1381   NatIso.nat2list                 ~> list_decode
  1382   NatIso.set2nat                  ~> set_encode
  1383   NatIso.nat2set                  ~> set_decode
  1384 
  1385   Lemmas:
  1386   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1387   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1388   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1389   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1390   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1391   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1392   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1393   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1394   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1395   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1396   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1397   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1398   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1399 
  1400 * Sledgehammer:
  1401   - Renamed ATP commands:
  1402     atp_info     ~> sledgehammer running_atps
  1403     atp_kill     ~> sledgehammer kill_atps
  1404     atp_messages ~> sledgehammer messages
  1405     atp_minimize ~> sledgehammer minimize
  1406     print_atps   ~> sledgehammer available_atps
  1407     INCOMPATIBILITY.
  1408   - Added user's manual ("isabelle doc sledgehammer").
  1409   - Added option syntax and "sledgehammer_params" to customize
  1410     Sledgehammer's behavior.  See the manual for details.
  1411   - Modified the Isar proof reconstruction code so that it produces
  1412     direct proofs rather than proofs by contradiction.  (This feature
  1413     is still experimental.)
  1414   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1415     full-typed mode.
  1416   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1417 
  1418 * Nitpick:
  1419   - Added and implemented "binary_ints" and "bits" options.
  1420   - Added "std" option and implemented support for nonstandard models.
  1421   - Added and implemented "finitize" option to improve the precision
  1422     of infinite datatypes based on a monotonicity analysis.
  1423   - Added support for quotient types.
  1424   - Added support for "specification" and "ax_specification"
  1425     constructs.
  1426   - Added support for local definitions (for "function" and
  1427     "termination" proofs).
  1428   - Added support for term postprocessors.
  1429   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1430   - Improved efficiency of "destroy_constrs" optimization.
  1431   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1432     record getters.
  1433   - Fixed soundness bug related to higher-order constructors.
  1434   - Fixed soundness bug when "full_descrs" is enabled.
  1435   - Improved precision of set constructs.
  1436   - Added "atoms" option.
  1437   - Added cache to speed up repeated Kodkod invocations on the same
  1438     problems.
  1439   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1440     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1441     "SAT4J_Light".  INCOMPATIBILITY.
  1442   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1443     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1444   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1445 
  1446 * Method "induct" now takes instantiations of the form t, where t is not
  1447   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1448   If this is not intended, t has to be enclosed in parentheses.
  1449   By default, the equalities generated by definitional instantiations
  1450   are pre-simplified, which may cause parameters of inductive cases
  1451   to disappear, or may even delete some of the inductive cases.
  1452   Use "induct (no_simp)" instead of "induct" to restore the old
  1453   behaviour. The (no_simp) option is also understood by the "cases"
  1454   and "nominal_induct" methods, which now perform pre-simplification, too.
  1455   INCOMPATIBILITY.
  1456 
  1457 
  1458 *** HOLCF ***
  1459 
  1460 * Variable names in lemmas generated by the domain package have
  1461 changed; the naming scheme is now consistent with the HOL datatype
  1462 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1463 
  1464 * The domain package no longer defines the function "foo_copy" for
  1465 recursive domain "foo".  The reach lemma is now stated directly in
  1466 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1467 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1468 
  1469 * Most definedness lemmas generated by the domain package (previously
  1470 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1471 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1472 Proofs that used definedness lemmas as intro rules may break,
  1473 potential INCOMPATIBILITY.
  1474 
  1475 * Induction and casedist rules generated by the domain package now
  1476 declare proper case_names (one called "bottom", and one named for each
  1477 constructor).  INCOMPATIBILITY.
  1478 
  1479 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1480 rules are generated for each domain, INCOMPATIBILITY.
  1481 
  1482   foo_bar.reach       ~> foo.reach  bar.reach
  1483   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1484 
  1485 * Some lemmas generated by the domain package have been renamed for
  1486 consistency with the datatype package, INCOMPATIBILITY.
  1487 
  1488   foo.ind        ~> foo.induct
  1489   foo.finite_ind ~> foo.finite_induct
  1490   foo.coind      ~> foo.coinduct
  1491   foo.casedist   ~> foo.exhaust
  1492   foo.exhaust    ~> foo.nchotomy
  1493 
  1494 * For consistency with other definition packages, the fixrec package
  1495 now generates qualified theorem names, INCOMPATIBILITY.
  1496 
  1497   foo_simps  ~> foo.simps
  1498   foo_unfold ~> foo.unfold
  1499   foo_induct ~> foo.induct
  1500 
  1501 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1502 method and internal fixrec proofs now use the default simpset instead.
  1503 INCOMPATIBILITY.
  1504 
  1505 * The "contlub" predicate has been removed.  Proof scripts should use
  1506 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1507 
  1508 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1509 
  1510 * The constants cpair, cfst, and csnd have been removed in favor of
  1511 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1512 
  1513 
  1514 *** ML ***
  1515 
  1516 * Antiquotations for basic formal entities:
  1517 
  1518     @{class NAME}         -- type class
  1519     @{class_syntax NAME}  -- syntax representation of the above
  1520 
  1521     @{type_name NAME}     -- logical type
  1522     @{type_abbrev NAME}   -- type abbreviation
  1523     @{nonterminal NAME}   -- type of concrete syntactic category
  1524     @{type_syntax NAME}   -- syntax representation of any of the above
  1525 
  1526     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1527     @{const_abbrev NAME}  -- abbreviated constant
  1528     @{const_syntax NAME}  -- syntax representation of any of the above
  1529 
  1530 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1531 syntax constant (cf. 'syntax' command).
  1532 
  1533 * Antiquotation @{make_string} inlines a function to print arbitrary
  1534 values similar to the ML toplevel.  The result is compiler dependent
  1535 and may fall back on "?" in certain situations.
  1536 
  1537 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1538 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1539 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1540 not work with the asynchronous Isar document model.
  1541 
  1542 * Configuration options now admit dynamic default values, depending on
  1543 the context or even global references.
  1544 
  1545 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1546 uses an efficient external library if available (for Poly/ML).
  1547 
  1548 * Renamed some important ML structures, while keeping the old names
  1549 for some time as aliases within the structure Legacy:
  1550 
  1551   OuterKeyword  ~>  Keyword
  1552   OuterLex      ~>  Token
  1553   OuterParse    ~>  Parse
  1554   OuterSyntax   ~>  Outer_Syntax
  1555   PrintMode     ~>  Print_Mode
  1556   SpecParse     ~>  Parse_Spec
  1557   ThyInfo       ~>  Thy_Info
  1558   ThyLoad       ~>  Thy_Load
  1559   ThyOutput     ~>  Thy_Output
  1560   TypeInfer     ~>  Type_Infer
  1561 
  1562 Note that "open Legacy" simplifies porting of sources, but forgetting
  1563 to remove it again will complicate porting again in the future.
  1564 
  1565 * Most operations that refer to a global context are named
  1566 accordingly, e.g. Simplifier.global_context or
  1567 ProofContext.init_global.  There are some situations where a global
  1568 context actually works, but under normal circumstances one needs to
  1569 pass the proper local context through the code!
  1570 
  1571 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1572 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1573 Pretty.pp argument to merge, which is absent in the standard
  1574 Theory_Data version.
  1575 
  1576 * Sorts.certify_sort and derived "cert" operations for types and terms
  1577 no longer minimize sorts.  Thus certification at the boundary of the
  1578 inference kernel becomes invariant under addition of class relations,
  1579 which is an important monotonicity principle.  Sorts are now minimized
  1580 in the syntax layer only, at the boundary between the end-user and the
  1581 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1582 explicitly in rare situations.
  1583 
  1584 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1585 emphasize that this is in no way a standard operation.
  1586 INCOMPATIBILITY.
  1587 
  1588 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1589 usual for resolution.  Rare INCOMPATIBILITY.
  1590 
  1591 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1592 to emphasize that these only work in a global situation (which is
  1593 quite rare).
  1594 
  1595 * Curried take and drop in library.ML; negative length is interpreted
  1596 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1597 
  1598 * Proof terms: type substitutions on proof constants now use canonical
  1599 order of type variables.  INCOMPATIBILITY for tools working with proof
  1600 terms.
  1601 
  1602 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1603 may no longer carry premises.  User-level specifications are
  1604 transformed accordingly by Thm.add_axiom/add_def.
  1605 
  1606 
  1607 *** System ***
  1608 
  1609 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1610 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1611 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1612 
  1613 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1614 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1615 respectively.
  1616 
  1617 * Old lib/scripts/polyml-platform is superseded by the
  1618 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1619 variant, even on a 64 bit machine.  The following example setting
  1620 prefers 64 bit if available:
  1621 
  1622   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1623 
  1624 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1625 Isabelle/Scala layer for advanced prover interaction and integration.
  1626 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1627 component.
  1628 
  1629 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1630 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1631 similar to the default assignment of the document preparation system
  1632 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1633 provides some operations for direct access to the font without asking
  1634 the user for manual installation.
  1635 
  1636 
  1637 
  1638 New in Isabelle2009-1 (December 2009)
  1639 -------------------------------------
  1640 
  1641 *** General ***
  1642 
  1643 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1644 one backslash should be used, even in ML sources.
  1645 
  1646 
  1647 *** Pure ***
  1648 
  1649 * Locale interpretation propagates mixins along the locale hierarchy.
  1650 The currently only available mixins are the equations used to map
  1651 local definitions to terms of the target domain of an interpretation.
  1652 
  1653 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1654 loc" to print all interpretations of locale "loc" in the theory.
  1655 Interpretations in proofs are not shown.
  1656 
  1657 * Thoroughly revised locales tutorial.  New section on conditional
  1658 interpretation.
  1659 
  1660 * On instantiation of classes, remaining undefined class parameters
  1661 are formally declared.  INCOMPATIBILITY.
  1662 
  1663 
  1664 *** Document preparation ***
  1665 
  1666 * New generalized style concept for printing terms: @{foo (style) ...}
  1667 instead of @{foo_style style ...}  (old form is still retained for
  1668 backward compatibility).  Styles can be also applied for
  1669 antiquotations prop, term_type and typeof.
  1670 
  1671 
  1672 *** HOL ***
  1673 
  1674 * New proof method "smt" for a combination of first-order logic with
  1675 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1676 fixed-size bitvectors; there is also basic support for higher-order
  1677 features (esp. lambda abstractions).  It is an incomplete decision
  1678 procedure based on external SMT solvers using the oracle mechanism;
  1679 for the SMT solver Z3, this method is proof-producing.  Certificates
  1680 are provided to avoid calling the external solvers solely for
  1681 re-checking proofs.  Due to a remote SMT service there is no need for
  1682 installing SMT solvers locally.  See src/HOL/SMT.
  1683 
  1684 * New commands to load and prove verification conditions generated by
  1685 the Boogie program verifier or derived systems (e.g. the Verifying C
  1686 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1687 
  1688 * New counterexample generator tool 'nitpick' based on the Kodkod
  1689 relational model finder.  See src/HOL/Tools/Nitpick and
  1690 src/HOL/Nitpick_Examples.
  1691 
  1692 * New commands 'code_pred' and 'values' to invoke the predicate
  1693 compiler and to enumerate values of inductive predicates.
  1694 
  1695 * A tabled implementation of the reflexive transitive closure.
  1696 
  1697 * New implementation of quickcheck uses generic code generator;
  1698 default generators are provided for all suitable HOL types, records
  1699 and datatypes.  Old quickcheck can be re-activated importing theory
  1700 Library/SML_Quickcheck.
  1701 
  1702 * New testing tool Mirabelle for automated proof tools.  Applies
  1703 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1704 every proof step in a theory.  To be used in batch mode via the
  1705 "mirabelle" utility.
  1706 
  1707 * New proof method "sos" (sum of squares) for nonlinear real
  1708 arithmetic (originally due to John Harison). It requires theory
  1709 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1710 works well in practice on quantifier-free real arithmetic with +, -,
  1711 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1712 inequalities between polynomials.  It makes use of external
  1713 semidefinite programming solvers.  Method "sos" generates a
  1714 certificate that can be pasted into the proof thus avoiding the need
  1715 to call an external tool every time the proof is checked.  See
  1716 src/HOL/Library/Sum_Of_Squares.
  1717 
  1718 * New method "linarith" invokes existing linear arithmetic decision
  1719 procedure only.
  1720 
  1721 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1722 
  1723 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1724 Causes full type information to be output to the ATPs.  This slows
  1725 ATPs down considerably but eliminates a source of unsound "proofs"
  1726 that fail later.
  1727 
  1728 * New method "metisFT": A version of metis that uses full type
  1729 information in order to avoid failures of proof reconstruction.
  1730 
  1731 * New evaluator "approximate" approximates an real valued term using
  1732 the same method as the approximation method.
  1733 
  1734 * Method "approximate" now supports arithmetic expressions as
  1735 boundaries of intervals and implements interval splitting and Taylor
  1736 series expansion.
  1737 
  1738 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1739 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1740 
  1741 * New theory SupInf of the supremum and infimum operators for sets of
  1742 reals.
  1743 
  1744 * New theory Probability, which contains a development of measure
  1745 theory, eventually leading to Lebesgue integration and probability.
  1746 
  1747 * Extended Multivariate Analysis to include derivation and Brouwer's
  1748 fixpoint theorem.
  1749 
  1750 * Reorganization of number theory, INCOMPATIBILITY:
  1751   - new number theory development for nat and int, in theories Divides
  1752     and GCD as well as in new session Number_Theory
  1753   - some constants and facts now suffixed with _nat and _int
  1754     accordingly
  1755   - former session NumberTheory now named Old_Number_Theory, including
  1756     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1757   - moved theory Pocklington from src/HOL/Library to
  1758     src/HOL/Old_Number_Theory
  1759 
  1760 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1761 lcm of finite and infinite sets. It is shown that they form a complete
  1762 lattice.
  1763 
  1764 * Class semiring_div requires superclass no_zero_divisors and proof of
  1765 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1766 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1767 generalized to class semiring_div, subsuming former theorems
  1768 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1769 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1770 INCOMPATIBILITY.
  1771 
  1772 * Refinements to lattice classes and sets:
  1773   - less default intro/elim rules in locale variant, more default
  1774     intro/elim rules in class variant: more uniformity
  1775   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1776     le_inf_iff
  1777   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1778     sup_aci)
  1779   - renamed ACI to inf_sup_aci
  1780   - new class "boolean_algebra"
  1781   - class "complete_lattice" moved to separate theory
  1782     "Complete_Lattice"; corresponding constants (and abbreviations)
  1783     renamed and with authentic syntax:
  1784     Set.Inf ~>    Complete_Lattice.Inf
  1785     Set.Sup ~>    Complete_Lattice.Sup
  1786     Set.INFI ~>   Complete_Lattice.INFI
  1787     Set.SUPR ~>   Complete_Lattice.SUPR
  1788     Set.Inter ~>  Complete_Lattice.Inter
  1789     Set.Union ~>  Complete_Lattice.Union
  1790     Set.INTER ~>  Complete_Lattice.INTER
  1791     Set.UNION ~>  Complete_Lattice.UNION
  1792   - authentic syntax for
  1793     Set.Pow
  1794     Set.image
  1795   - mere abbreviations:
  1796     Set.empty               (for bot)
  1797     Set.UNIV                (for top)
  1798     Set.inter               (for inf, formerly Set.Int)
  1799     Set.union               (for sup, formerly Set.Un)
  1800     Complete_Lattice.Inter  (for Inf)
  1801     Complete_Lattice.Union  (for Sup)
  1802     Complete_Lattice.INTER  (for INFI)
  1803     Complete_Lattice.UNION  (for SUPR)
  1804   - object-logic definitions as far as appropriate
  1805 
  1806 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1807 Un_subset_iff are explicitly deleted as default simp rules; then also
  1808 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1809 deleted to achieve the desired effect.
  1810 
  1811 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1812 rules by default any longer; the same applies to min_max.inf_absorb1
  1813 etc.  INCOMPATIBILITY.
  1814 
  1815 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1816 pred_set_conv by default.  INCOMPATIBILITY.
  1817 
  1818 * Power operations on relations and functions are now one dedicated
  1819 constant "compow" with infix syntax "^^".  Power operation on
  1820 multiplicative monoids retains syntax "^" and is now defined generic
  1821 in class power.  INCOMPATIBILITY.
  1822 
  1823 * Relation composition "R O S" now has a more standard argument order:
  1824 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1825 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1826 break, since the O_assoc rule was not rewritten like this.  Fix using
  1827 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1828 
  1829 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1830 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1831 INCOMPATIBILITY.
  1832 
  1833 * Most rules produced by inductive and datatype package have mandatory
  1834 prefixes.  INCOMPATIBILITY.
  1835 
  1836 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1837 the attribute of the same name.  Each of the theorems in the list
  1838 DERIV_intros assumes composition with an additional function and
  1839 matches a variable to the derivative, which has to be solved by the
  1840 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1841 of most elementary terms.  Former Maclauren.DERIV_tac and
  1842 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1843 INCOMPATIBILITY.
  1844 
  1845 * Code generator attributes follow the usual underscore convention:
  1846     code_unfold     replaces    code unfold
  1847     code_post       replaces    code post
  1848     etc.
  1849   INCOMPATIBILITY.
  1850 
  1851 * Renamed methods:
  1852     sizechange -> size_change
  1853     induct_scheme -> induction_schema
  1854   INCOMPATIBILITY.
  1855 
  1856 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1857 INCOMPATIBILITY, use "undefined" directly.
  1858 
  1859 * Renamed theorems:
  1860     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1861     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1862     Suc_plus1 -> Suc_eq_plus1
  1863     *anti_sym -> *antisym*
  1864     vector_less_eq_def -> vector_le_def
  1865   INCOMPATIBILITY.
  1866 
  1867 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1868 INCOMPATIBILITY.
  1869 
  1870 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1871 INCOMPATIBILITY.
  1872 
  1873 
  1874 *** HOLCF ***
  1875 
  1876 * Theory Representable defines a class "rep" of domains that are
  1877 representable (via an ep-pair) in the universal domain type "udom".
  1878 Instances are provided for all type constructors defined in HOLCF.
  1879 
  1880 * The 'new_domain' command is a purely definitional version of the
  1881 domain package, for representable domains.  Syntax is identical to the
  1882 old domain package.  The 'new_domain' package also supports indirect
  1883 recursion using previously-defined type constructors.  See
  1884 src/HOLCF/ex/New_Domain.thy for examples.
  1885 
  1886 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1887 on the left-hand side of an equation, and then performs
  1888 simplification.  Rewriting is done using rules declared with the
  1889 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1890 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1891 
  1892 * The pattern-match compiler in 'fixrec' can now handle constructors
  1893 with HOL function types.  Pattern-match combinators for the Pair
  1894 constructor are pre-configured.
  1895 
  1896 * The 'fixrec' package now produces better fixed-point induction rules
  1897 for mutually-recursive definitions:  Induction rules have conclusions
  1898 of the form "P foo bar" instead of "P <foo, bar>".
  1899 
  1900 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1901 been renamed to "below".  The name "below" now replaces "less" in many
  1902 theorem names.  (Legacy theorem names using "less" are still supported
  1903 as well.)
  1904 
  1905 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1906 patterns can be used to generate strictness rules, or to make
  1907 functions more strict (much like the bang-patterns supported by the
  1908 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1909 examples.
  1910 
  1911 
  1912 *** ML ***
  1913 
  1914 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1915 errors and run-time exceptions, including detailed source positions.
  1916 
  1917 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1918 identified entries, with some additional information such as source
  1919 position, logical grouping etc.
  1920 
  1921 * Theory and context data is now introduced by the simplified and
  1922 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1923 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1924 copy operation) is still available for some time.
  1925 
  1926 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1927 provides a high-level programming interface to synchronized state
  1928 variables with atomic update.  This works via pure function
  1929 application within a critical section -- its runtime should be as
  1930 short as possible; beware of deadlocks if critical code is nested,
  1931 either directly or indirectly via other synchronized variables!
  1932 
  1933 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1934 wraps raw ML references, explicitly indicating their non-thread-safe
  1935 behaviour.  The Isar toplevel keeps this structure open, to
  1936 accommodate Proof General as well as quick and dirty interactive
  1937 experiments with references.
  1938 
  1939 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1940 parallel tactical reasoning.
  1941 
  1942 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1943 are similar to SUBPROOF, but are slightly more flexible: only the
  1944 specified parts of the subgoal are imported into the context, and the
  1945 body tactic may introduce new subgoals and schematic variables.
  1946 
  1947 * Old tactical METAHYPS, which does not observe the proof context, has
  1948 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1949 or Subgoal.FOCUS etc.
  1950 
  1951 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1952 functors have their own ML name space there is no point to mark them
  1953 separately.)  Minor INCOMPATIBILITY.
  1954 
  1955 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1956 
  1957 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1958 INCOMPATIBILITY.
  1959 
  1960 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1961 mode, which avoids critical setmp.
  1962 
  1963 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1964 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1965 Attrib/Method.setup introduced in Isabelle2009.
  1966 
  1967 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1968 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1969 last resort.  INCOMPATIBILITY.
  1970 
  1971 * Display.pretty_thm now requires a proper context (cf. former
  1972 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1973 or even Display.pretty_thm_without_context as last resort.
  1974 INCOMPATIBILITY.
  1975 
  1976 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1977 Syntax.pretty_typ/term directly, preferably with proper context
  1978 instead of global theory.
  1979 
  1980 
  1981 *** System ***
  1982 
  1983 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1984 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1985 usedir option -q.
  1986 
  1987 * Support for additional "Isabelle components" via etc/components, see
  1988 also the system manual.
  1989 
  1990 * The isabelle makeall tool now operates on all components with
  1991 IsaMakefile, not just hardwired "logics".
  1992 
  1993 * Removed "compress" option from isabelle-process and isabelle usedir;
  1994 this is always enabled.
  1995 
  1996 * Discontinued support for Poly/ML 4.x versions.
  1997 
  1998 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1999 on a given logic image.  This requires the lighttpd webserver and is
  2000 currently supported on Linux only.
  2001 
  2002 
  2003 
  2004 New in Isabelle2009 (April 2009)
  2005 --------------------------------
  2006 
  2007 *** General ***
  2008 
  2009 * Simplified main Isabelle executables, with less surprises on
  2010 case-insensitive file-systems (such as Mac OS).
  2011 
  2012   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2013     "isatool."
  2014 
  2015   - The former "isabelle" alias for "isabelle-process" has been
  2016     removed (should rarely occur to regular users).
  2017 
  2018   - The former "isabelle-interface" and its alias "Isabelle" have been
  2019     removed (interfaces are now regular Isabelle tools).
  2020 
  2021 Within scripts and make files, the Isabelle environment variables
  2022 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2023 respectively.  (The latter are still available as legacy feature.)
  2024 
  2025 The old isabelle-interface wrapper could react in confusing ways if
  2026 the interface was uninstalled or changed otherwise.  Individual
  2027 interface tool configuration is now more explicit, see also the
  2028 Isabelle system manual.  In particular, Proof General is now available
  2029 via "isabelle emacs".
  2030 
  2031 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2032 purge installed copies of Isabelle executables and re-run "isabelle
  2033 install -p ...", or use symlinks.
  2034 
  2035 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2036 old ~/isabelle, which was slightly non-standard and apt to cause
  2037 surprises on case-insensitive file-systems (such as Mac OS).
  2038 
  2039 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2040 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2041 care is required when using older releases of Isabelle.  Note that
  2042 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2043 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2044 
  2045 * Proofs of fully specified statements are run in parallel on
  2046 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2047 a regular 4-core machine, if the initial heap space is made reasonably
  2048 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2049 
  2050 * The main reference manuals ("isar-ref", "implementation", and
  2051 "system") have been updated and extended.  Formally checked references
  2052 as hyperlinks are now available uniformly.
  2053 
  2054 
  2055 *** Pure ***
  2056 
  2057 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2058 respects.  The most important changes are listed below.  See the
  2059 Tutorial on Locales ("locales" manual) for details.
  2060 
  2061 - In locale expressions, instantiation replaces renaming.  Parameters
  2062 must be declared in a for clause.  To aid compatibility with previous
  2063 parameter inheritance, in locale declarations, parameters that are not
  2064 'touched' (instantiation position "_" or omitted) are implicitly added
  2065 with their syntax at the beginning of the for clause.
  2066 
  2067 - Syntax from abbreviations and definitions in locales is available in
  2068 locale expressions and context elements.  The latter is particularly
  2069 useful in locale declarations.
  2070 
  2071 - More flexible mechanisms to qualify names generated by locale
  2072 expressions.  Qualifiers (prefixes) may be specified in locale
  2073 expressions, and can be marked as mandatory (syntax: "name!:") or
  2074 optional (syntax "name?:").  The default depends for plain "name:"
  2075 depends on the situation where a locale expression is used: in
  2076 commands 'locale' and 'sublocale' prefixes are optional, in
  2077 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2078 implicit qualifiers derived from the parameter names of a locale are
  2079 no longer generated.
  2080 
  2081 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2082 instantiation clause in "interpretation" and "interpret" (square
  2083 brackets) is no longer available.  Use locale expressions.
  2084 
  2085 - When converting proof scripts, mandatory qualifiers in
  2086 'interpretation' and 'interpret' should be retained by default, even
  2087 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2088 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2089 in locale expressions range over a single locale instance only.
  2090 
  2091 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2092 In existing theorem specifications replace the includes element by the
  2093 respective context elements of the included locale, omitting those
  2094 that are already present in the theorem specification.  Multiple
  2095 assume elements of a locale should be replaced by a single one
  2096 involving the locale predicate.  In the proof body, declarations (most
  2097 notably theorems) may be regained by interpreting the respective
  2098 locales in the proof context as required (command "interpret").
  2099 
  2100 If using "includes" in replacement of a target solely because the
  2101 parameter types in the theorem are not as general as in the target,
  2102 consider declaring a new locale with additional type constraints on
  2103 the parameters (context element "constrains").
  2104 
  2105 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2106 
  2107 - Locale interpretation commands no longer attempt to simplify goal.
  2108 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2109 methods intro_locales and unfold_locales to clarify.
  2110 
  2111 - Locale interpretation commands no longer accept interpretation
  2112 attributes.  INCOMPATIBILITY.
  2113 
  2114 * Class declaration: so-called "base sort" must not be given in import
  2115 list any longer, but is inferred from the specification.  Particularly
  2116 in HOL, write
  2117 
  2118     class foo = ...
  2119 
  2120 instead of
  2121 
  2122     class foo = type + ...
  2123 
  2124 * Class target: global versions of theorems stemming do not carry a
  2125 parameter prefix any longer.  INCOMPATIBILITY.
  2126 
  2127 * Class 'instance' command no longer accepts attached definitions.
  2128 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2129 
  2130 * Recovered hiding of consts, which was accidentally broken in
  2131 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2132 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2133 
  2134 * Slightly more coherent Pure syntax, with updated documentation in
  2135 isar-ref manual.  Removed locales meta_term_syntax and
  2136 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2137 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2138 directly in regular applications.
  2139 
  2140 * There is a new syntactic category "float_const" for signed decimal
  2141 fractions (e.g. 123.45 or -123.45).
  2142 
  2143 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2144 interface with 'setup' command instead.
  2145 
  2146 * Command 'local_setup' is similar to 'setup', but operates on a local
  2147 theory context.
  2148 
  2149 * The 'axiomatization' command now only works within a global theory
  2150 context.  INCOMPATIBILITY.
  2151 
  2152 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2153 hypotheses.  Sorts required in the course of reasoning need to be
  2154 covered by the constraints in the initial statement, completed by the
  2155 type instance information of the background theory.  Non-trivial sort
  2156 hypotheses, which rarely occur in practice, may be specified via
  2157 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2158 
  2159   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2160 
  2161 The result contains an implicit sort hypotheses as before --
  2162 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2163 normalization.
  2164 
  2165 * Generalized Isar history, with support for linear undo, direct state
  2166 addressing etc.
  2167 
  2168 * Changed defaults for unify configuration options:
  2169 
  2170   unify_trace_bound = 50 (formerly 25)
  2171   unify_search_bound = 60 (formerly 30)
  2172 
  2173 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2174 
  2175   a) On theory merge, the last set of code equations for a particular
  2176      constant is taken (in accordance with the policy applied by other
  2177      parts of the code generator framework).
  2178 
  2179   b) Code equations stemming from explicit declarations (e.g. code
  2180      attribute) gain priority over default code equations stemming
  2181      from definition, primrec, fun etc.
  2182 
  2183 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2184 
  2185 * Unified theorem tables for both code generators.  Thus [code
  2186 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2187 
  2188 * Command 'find_consts' searches for constants based on type and name
  2189 patterns, e.g.
  2190 
  2191     find_consts "_ => bool"
  2192 
  2193 By default, matching is against subtypes, but it may be restricted to
  2194 the whole type.  Searching by name is possible.  Multiple queries are
  2195 conjunctive and queries may be negated by prefixing them with a
  2196 hyphen:
  2197 
  2198     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2199 
  2200 * New 'find_theorems' criterion "solves" matches theorems that
  2201 directly solve the current goal (modulo higher-order unification).
  2202 
  2203 * Auto solve feature for main theorem statements: whenever a new goal
  2204 is stated, "find_theorems solves" is called; any theorems that could
  2205 solve the lemma directly are listed as part of the goal state.
  2206 Cf. associated options in Proof General Isabelle settings menu,
  2207 enabled by default, with reasonable timeout for pathological cases of
  2208 higher-order unification.
  2209 
  2210 
  2211 *** Document preparation ***
  2212 
  2213 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2214 demanding keyword 'by' and supporting the full method expression
  2215 syntax just like the Isar command 'by'.
  2216 
  2217 
  2218 *** HOL ***
  2219 
  2220 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2221 points Main and Complex_Main remain as before.
  2222 
  2223 * Logic image HOL-Plain provides a minimal HOL with the most important
  2224 tools available (inductive, datatype, primrec, ...).  This facilitates
  2225 experimentation and tool development.  Note that user applications
  2226 (and library theories) should never refer to anything below theory
  2227 Main, as before.
  2228 
  2229 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2230 experimentation due to shorter build times.
  2231 
  2232 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2233 were previously part of former HOL-Complex.  Entry point Hyperreal
  2234 remains valid, but theories formerly using Complex_Main should now use
  2235 new entry point Hypercomplex.
  2236 
  2237 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2238 Posix processes.  Avoids potentially expensive forking of the ML
  2239 process.  New thread-based implementation also works on non-Unix
  2240 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2241 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2242 commands are covered in the isar-ref manual.
  2243 
  2244 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2245 sledgehammer without local ATP installation (Vampire etc.). Other
  2246 provers may be included via suitable ML wrappers, see also
  2247 src/HOL/ATP_Linkup.thy.
  2248 
  2249 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2250 menu.
  2251 
  2252 * The metis method no longer fails because the theorem is too trivial
  2253 (contains the empty clause).
  2254 
  2255 * The metis method now fails in the usual manner, rather than raising
  2256 an exception, if it determines that it cannot prove the theorem.
  2257 
  2258 * Method "coherent" implements a prover for coherent logic (see also
  2259 src/Tools/coherent.ML).
  2260 
  2261 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2262 "undefined" is the right choice to replace "arbitrary", though
  2263 logically there is no difference.  INCOMPATIBILITY.
  2264 
  2265 * Command "value" now integrates different evaluation mechanisms.  The
  2266 result of the first successful evaluation mechanism is printed.  In
  2267 square brackets a particular named evaluation mechanisms may be
  2268 specified (currently, [SML], [code] or [nbe]).  See further
  2269 src/HOL/ex/Eval_Examples.thy.
  2270 
  2271 * Normalization by evaluation now allows non-leftlinear equations.
  2272 Declare with attribute [code nbe].
  2273 
  2274 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2275 as the structured Isar versions "cases" and "induct", cf. the
  2276 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2277 are now presented as a list of individual projections
  2278 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2279 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2280 rare situations a different rule is selected --- notably nested tuple
  2281 elimination instead of former prod.exhaust: use explicit (case_tac t
  2282 rule: prod.exhaust) here.
  2283 
  2284 * Attributes "cases", "induct", "coinduct" support "del" option.
  2285 
  2286 * Removed fact "case_split_thm", which duplicates "case_split".
  2287 
  2288 * The option datatype has been moved to a new theory Option.  Renamed
  2289 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2290 
  2291 * New predicate "strict_mono" classifies strict functions on partial
  2292 orders.  With strict functions on linear orders, reasoning about
  2293 (in)equalities is facilitated by theorems "strict_mono_eq",
  2294 "strict_mono_less_eq" and "strict_mono_less".
  2295 
  2296 * Some set operations are now proper qualified constants with
  2297 authentic syntax.  INCOMPATIBILITY:
  2298 
  2299     op Int ~>   Set.Int
  2300     op Un ~>    Set.Un
  2301     INTER ~>    Set.INTER
  2302     UNION ~>    Set.UNION
  2303     Inter ~>    Set.Inter
  2304     Union ~>    Set.Union
  2305     {} ~>       Set.empty
  2306     UNIV ~>     Set.UNIV
  2307 
  2308 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2309 theory Set.
  2310 
  2311 * Auxiliary class "itself" has disappeared -- classes without any
  2312 parameter are treated as expected by the 'class' command.
  2313 
  2314 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2315 
  2316 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2317 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2318 
  2319 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2320 method "approximation".  It proves formulas on real values by using
  2321 interval arithmetic.  In the formulas are also the transcendental
  2322 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2323 allowed. For examples see
  2324 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2325 
  2326 * Theory "Reflection" now resides in HOL/Library.
  2327 
  2328 * Entry point to Word library now simply named "Word".
  2329 INCOMPATIBILITY.
  2330 
  2331 * Made source layout more coherent with logical distribution
  2332 structure:
  2333 
  2334     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2335     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2336     src/HOL/Library/GCD.thy ~> src/HOL/
  2337     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2338     src/HOL/Library/Parity.thy ~> src/HOL/
  2339     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2340     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2341     src/HOL/Real/Lubs.thy ~> src/HOL/
  2342     src/HOL/Real/PReal.thy ~> src/HOL/
  2343     src/HOL/Real/Rational.thy ~> src/HOL/
  2344     src/HOL/Real/RComplete.thy ~> src/HOL/
  2345     src/HOL/Real/RealDef.thy ~> src/HOL/
  2346     src/HOL/Real/RealPow.thy ~> src/HOL/
  2347     src/HOL/Real/Real.thy ~> src/HOL/
  2348     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2349     src/HOL/Complex/Complex.thy ~> src/HOL/
  2350     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2351     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2352     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2353     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2354     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2355     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2356     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2357     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2358     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2359     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2360     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2361     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2362     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2363     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2364     src/HOL/Real/Float ~> src/HOL/Library/
  2365     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2366     src/HOL/Real/RealVector.thy ~> src/HOL/
  2367 
  2368     src/HOL/arith_data.ML ~> src/HOL/Tools
  2369     src/HOL/hologic.ML ~> src/HOL/Tools
  2370     src/HOL/simpdata.ML ~> src/HOL/Tools
  2371     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2372     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2373     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2374     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2375     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2376     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2377     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2378 
  2379     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2380     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2381     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2382     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2383     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2384     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2385 
  2386 * If methods "eval" and "evaluation" encounter a structured proof
  2387 state with !!/==>, only the conclusion is evaluated to True (if
  2388 possible), avoiding strange error messages.
  2389 
  2390 * Method "sizechange" automates termination proofs using (a
  2391 modification of) the size-change principle.  Requires SAT solver.  See
  2392 src/HOL/ex/Termination.thy for examples.
  2393 
  2394 * Simplifier: simproc for let expressions now unfolds if bound
  2395 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2396 
  2397 * Method "arith": Linear arithmetic now ignores all inequalities when
  2398 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2399 
  2400 * New attribute "arith" for facts that should always be used
  2401 automatically by arithmetic. It is intended to be used locally in
  2402 proofs, e.g.
  2403 
  2404   assumes [arith]: "x > 0"
  2405 
  2406 Global usage is discouraged because of possible performance impact.
  2407 
  2408 * New classes "top" and "bot" with corresponding operations "top" and
  2409 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2410 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2411 
  2412 * Changed definition lemma "less_fun_def" in order to provide an
  2413 instance for preorders on functions; use lemma "less_le" instead.
  2414 INCOMPATIBILITY.
  2415 
  2416 * Theory Orderings: class "wellorder" moved here, with explicit
  2417 induction rule "less_induct" as assumption.  For instantiation of
  2418 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2419 INCOMPATIBILITY.
  2420 
  2421 * Theory Orderings: added class "preorder" as superclass of "order".
  2422 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2423 etc. slightly changed.  Some theorems named order_class.* now named
  2424 preorder_class.*.
  2425 
  2426 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2427 "diag" to "Id_on".
  2428 
  2429 * Theory Finite_Set: added a new fold combinator of type
  2430 
  2431   ('a => 'b => 'b) => 'b => 'a set => 'b
  2432 
  2433 Occasionally this is more convenient than the old fold combinator
  2434 which is now defined in terms of the new one and renamed to
  2435 fold_image.
  2436 
  2437 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2438 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2439 extended with further lemmas!).  At the moment both still exist but
  2440 the former will disappear at some point.
  2441 
  2442 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2443 class recpower.  Type-specific simp rules for various recpower types
  2444 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2445 
  2446 rat_power_0    -> power_0
  2447 rat_power_Suc  -> power_Suc
  2448 realpow_0      -> power_0
  2449 realpow_Suc    -> power_Suc
  2450 complexpow_0   -> power_0
  2451 complexpow_Suc -> power_Suc
  2452 power_poly_0   -> power_0
  2453 power_poly_Suc -> power_Suc
  2454 
  2455 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2456 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2457 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2458 of lemmas from Divides has been generalized from nat to class
  2459 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2460 renames resulting from duplicate elimination:
  2461 
  2462     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2463     zero_dvd_iff ~>         dvd_0_left_iff
  2464     dvd_0 ~>                dvd_0_right
  2465     DIVISION_BY_ZERO_DIV ~> div_by_0
  2466     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2467     mult_div ~>             div_mult_self2_is_id
  2468     mult_mod ~>             mod_mult_self2_is_0
  2469 
  2470 * Theory IntDiv: removed many lemmas that are instances of class-based
  2471 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2472 rename old lemmas as follows:
  2473 
  2474 dvd_diff               -> nat_dvd_diff
  2475 dvd_zminus_iff         -> dvd_minus_iff
  2476 mod_add1_eq            -> mod_add_eq
  2477 mod_mult1_eq           -> mod_mult_right_eq
  2478 mod_mult1_eq'          -> mod_mult_left_eq
  2479 mod_mult_distrib_mod   -> mod_mult_eq
  2480 nat_mod_add_left_eq    -> mod_add_left_eq
  2481 nat_mod_add_right_eq   -> mod_add_right_eq
  2482 nat_mod_div_trivial    -> mod_div_trivial
  2483 nat_mod_mod_trivial    -> mod_mod_trivial
  2484 zdiv_zadd_self1        -> div_add_self1
  2485 zdiv_zadd_self2        -> div_add_self2
  2486 zdiv_zmult_self1       -> div_mult_self2_is_id
  2487 zdiv_zmult_self2       -> div_mult_self1_is_id
  2488 zdvd_triv_left         -> dvd_triv_left
  2489 zdvd_triv_right        -> dvd_triv_right
  2490 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2491 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2492 zmod_zadd_left_eq      -> mod_add_left_eq
  2493 zmod_zadd_right_eq     -> mod_add_right_eq
  2494 zmod_zadd_self1        -> mod_add_self1
  2495 zmod_zadd_self2        -> mod_add_self2
  2496 zmod_zadd1_eq          -> mod_add_eq
  2497 zmod_zdiff1_eq         -> mod_diff_eq
  2498 zmod_zdvd_zmod         -> mod_mod_cancel
  2499 zmod_zmod_cancel       -> mod_mod_cancel
  2500 zmod_zmult_self1       -> mod_mult_self2_is_0
  2501 zmod_zmult_self2       -> mod_mult_self1_is_0
  2502 zmod_1                 -> mod_by_1
  2503 zdiv_1                 -> div_by_1
  2504 zdvd_abs1              -> abs_dvd_iff
  2505 zdvd_abs2              -> dvd_abs_iff
  2506 zdvd_refl              -> dvd_refl
  2507 zdvd_trans             -> dvd_trans
  2508 zdvd_zadd              -> dvd_add
  2509 zdvd_zdiff             -> dvd_diff
  2510 zdvd_zminus_iff        -> dvd_minus_iff
  2511 zdvd_zminus2_iff       -> minus_dvd_iff
  2512 zdvd_zmultD            -> dvd_mult_right
  2513 zdvd_zmultD2           -> dvd_mult_left
  2514 zdvd_zmult_mono        -> mult_dvd_mono
  2515 zdvd_0_right           -> dvd_0_right
  2516 zdvd_0_left            -> dvd_0_left_iff
  2517 zdvd_1_left            -> one_dvd
  2518 zminus_dvd_iff         -> minus_dvd_iff
  2519 
  2520 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2521 
  2522 * The real numbers offer decimal input syntax: 12.34 is translated
  2523 into 1234/10^2. This translation is not reversed upon output.
  2524 
  2525 * Theory Library/Polynomial defines an abstract type 'a poly of
  2526 univariate polynomials with coefficients of type 'a.  In addition to
  2527 the standard ring operations, it also supports div and mod.  Code
  2528 generation is also supported, using list-style constructors.
  2529 
  2530 * Theory Library/Inner_Product defines a class of real_inner for real
  2531 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2532 => real.  Class real_inner is a subclass of real_normed_vector from
  2533 theory RealVector.
  2534 
  2535 * Theory Library/Product_Vector provides instances for the product
  2536 type 'a * 'b of several classes from RealVector and Inner_Product.
  2537 Definitions of addition, subtraction, scalar multiplication, norms,
  2538 and inner products are included.
  2539 
  2540 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2541 addition to the field operations, numerals and case syntax are also
  2542 supported.
  2543 
  2544 * Theory Library/Diagonalize provides constructive version of Cantor's
  2545 first diagonalization argument.
  2546 
  2547 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2548 zlcm (for int); carried together from various gcd/lcm developements in
  2549 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2550 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2551 may recover tupled syntax as follows:
  2552 
  2553     hide (open) const gcd
  2554     abbreviation gcd where
  2555       "gcd == (%(a, b). GCD.gcd a b)"
  2556     notation (output)
  2557       GCD.gcd ("gcd '(_, _')")
  2558 
  2559 The same works for lcm, zgcd, zlcm.
  2560 
  2561 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2562 instantiations for algebraic structures.  Removed some duplicate
  2563 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2564 
  2565 * ML antiquotation @{code} takes a constant as argument and generates
  2566 corresponding code in background and inserts name of the corresponding
  2567 resulting ML value/function/datatype constructor binding in place.
  2568 All occurrences of @{code} with a single ML block are generated
  2569 simultaneously.  Provides a generic and safe interface for
  2570 instrumentalizing code generation.  See
  2571 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2572 In future you ought to refrain from ad-hoc compiling generated SML
  2573 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2574 cannot refer to constants for which user-defined serializations are
  2575 set.  Refer to the corresponding ML counterpart directly in that
  2576 cases.
  2577 
  2578 * Command 'rep_datatype': instead of theorem names the command now
  2579 takes a list of terms denoting the constructors of the type to be
  2580 represented as datatype.  The characteristic theorems have to be
  2581 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2582 have disappeared in favour of existing ones:
  2583 
  2584     unit_induct                 ~> unit.induct
  2585     prod_induct                 ~> prod.induct
  2586     sum_induct                  ~> sum.induct
  2587     Suc_Suc_eq                  ~> nat.inject
  2588     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2589 
  2590 
  2591 *** HOL-Algebra ***
  2592 
  2593 * New locales for orders and lattices where the equivalence relation
  2594 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2595 locales use a record structure with field eq for the equivalence.
  2596 
  2597 * New theory of factorial domains.
  2598 
  2599 * Units_l_inv and Units_r_inv are now simp rules by default.
  2600 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2601 and/or r_inv will now also require deletion of these lemmas.
  2602 
  2603 * Renamed the following theorems, INCOMPATIBILITY:
  2604 
  2605 UpperD ~> Upper_memD
  2606 LowerD ~> Lower_memD
  2607 least_carrier ~> least_closed
  2608 greatest_carrier ~> greatest_closed
  2609 greatest_Lower_above ~> greatest_Lower_below
  2610 one_zero ~> carrier_one_zero
  2611 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2612 
  2613 
  2614 *** HOL-Nominal ***
  2615 
  2616 * Nominal datatypes can now contain type-variables.
  2617 
  2618 * Commands 'nominal_inductive' and 'equivariance' work with local
  2619 theory targets.
  2620 
  2621 * Nominal primrec can now works with local theory targets and its
  2622 specification syntax now conforms to the general format as seen in
  2623 'inductive' etc.
  2624 
  2625 * Method "perm_simp" honours the standard simplifier attributes
  2626 (no_asm), (no_asm_use) etc.
  2627 
  2628 * The new predicate #* is defined like freshness, except that on the
  2629 left hand side can be a set or list of atoms.
  2630 
  2631 * Experimental command 'nominal_inductive2' derives strong induction
  2632 principles for inductive definitions.  In contrast to
  2633 'nominal_inductive', which can only deal with a fixed number of
  2634 binders, it can deal with arbitrary expressions standing for sets of
  2635 atoms to be avoided.  The only inductive definition we have at the
  2636 moment that needs this generalisation is the typing rule for Lets in
  2637 the algorithm W:
  2638 
  2639  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2640  -----------------------------------------------------------------
  2641          Gamma |- Let x be t1 in t2 : T2
  2642 
  2643 In this rule one wants to avoid all the binders that are introduced by
  2644 "close Gamma T1".  We are looking for other examples where this
  2645 feature might be useful.  Please let us know.
  2646 
  2647 
  2648 *** HOLCF ***
  2649 
  2650 * Reimplemented the simplification procedure for proving continuity
  2651 subgoals.  The new simproc is extensible; users can declare additional
  2652 continuity introduction rules with the attribute [cont2cont].
  2653 
  2654 * The continuity simproc now uses a different introduction rule for
  2655 solving continuity subgoals on terms with lambda abstractions.  In
  2656 some rare cases the new simproc may fail to solve subgoals that the
  2657 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2658 Potential INCOMPATIBILITY.
  2659 
  2660 * Command 'fixrec': specification syntax now conforms to the general
  2661 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2662 examples.  INCOMPATIBILITY.
  2663 
  2664 
  2665 *** ZF ***
  2666 
  2667 * Proof of Zorn's Lemma for partial orders.
  2668 
  2669 
  2670 *** ML ***
  2671 
  2672 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2673 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2674 depends on multithreading, so timouts will not work before Poly/ML
  2675 5.2.1!
  2676 
  2677 * High-level support for concurrent ML programming, see
  2678 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2679 particularly convenient to organize independent functional
  2680 computations.  The concept of "synchronized variables" provides a
  2681 higher-order interface for components with shared state, avoiding the
  2682 delicate details of mutexes and condition variables.  (Requires
  2683 Poly/ML 5.2.1 or later.)
  2684 
  2685 * ML bindings produced via Isar commands are stored within the Isar
  2686 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2687 become thread-safe and work with undo as expected (concerning
  2688 top-level bindings, not side-effects on global references).
  2689 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2690 compiler at runtime; really global bindings need to be given outside a
  2691 theory.  (Requires Poly/ML 5.2 or later.)
  2692 
  2693 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2694 context.  Top-level ML bindings are stored within the proof context in
  2695 a purely sequential fashion, disregarding the nested proof structure.
  2696 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2697 proof.  (Requires Poly/ML 5.2 or later.)
  2698 
  2699 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2700 and Method.setup, as well as Isar commands 'attribute_setup' and
  2701 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2702 existing code accordingly, or use plain 'setup' together with old
  2703 Method.add_method.
  2704 
  2705 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2706 to 'a -> thm, while results are always tagged with an authentic oracle
  2707 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2708 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2709 accordingly.  Note that extra performance may be gained by producing
  2710 the cterm carefully, avoiding slow Thm.cterm_of.
  2711 
  2712 * Simplified interface for defining document antiquotations via
  2713 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2714 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2715 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2716 examples.
  2717 
  2718 * More systematic treatment of long names, abstract name bindings, and
  2719 name space operations.  Basic operations on qualified names have been
  2720 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2721 Long_Name.append.  Old type bstring has been mostly replaced by
  2722 abstract type binding (see structure Binding), which supports precise
  2723 qualification by packages and local theory targets, as well as proper
  2724 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2725 bstring values into Binding.name, or better pass through abstract
  2726 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2727 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2728 
  2729 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2730 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2731 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2732 
  2733 * Disposed old type and term read functions (Sign.read_def_typ,
  2734 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2735 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2736 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2737 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2738 resort for legacy applications.
  2739 
  2740 * Disposed old declarations, tactics, tactic combinators that refer to
  2741 the simpset or claset of an implicit theory (such as Addsimps,
  2742 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2743 embedded ML text, or local_simpset_of with a proper context passed as
  2744 explicit runtime argument.
  2745 
  2746 * Rules and tactics that read instantiations (read_instantiate,
  2747 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2748 context, which is required for parsing and type-checking.  Moreover,
  2749 the variables are specified as plain indexnames, not string encodings
  2750 thereof.  INCOMPATIBILITY.
  2751 
  2752 * Generic Toplevel.add_hook interface allows to analyze the result of
  2753 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2754 for theorem dependency output of transactions resulting in a new
  2755 theory state.
  2756 
  2757 * ML antiquotations: block-structured compilation context indicated by
  2758 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2759 
  2760   @{binding name}                         - basic name binding
  2761   @{let ?pat = term}                      - term abbreviation (HO matching)
  2762   @{note name = fact}                     - fact abbreviation
  2763   @{thm fact}                             - singleton fact (with attributes)
  2764   @{thms fact}                            - general fact (with attributes)
  2765   @{lemma prop by method}                 - singleton goal
  2766   @{lemma prop by meth1 meth2}            - singleton goal
  2767   @{lemma prop1 ... propN by method}      - general goal
  2768   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2769   @{lemma (open) ...}                     - open derivation
  2770 
  2771 
  2772 *** System ***
  2773 
  2774 * The Isabelle "emacs" tool provides a specific interface to invoke
  2775 Proof General / Emacs, with more explicit failure if that is not
  2776 installed (the old isabelle-interface script silently falls back on
  2777 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2778 installation location of the Proof General distribution.
  2779 
  2780 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2781 the Isabelle process into a JVM/Scala application.  See
  2782 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2783 process wrapper has been discontinued.)
  2784 
  2785 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2786 
  2787 * Various status messages (with exact source position information) are
  2788 emitted, if proper markup print mode is enabled.  This allows
  2789 user-interface components to provide detailed feedback on internal
  2790 prover operations.
  2791 
  2792 
  2793 
  2794 New in Isabelle2008 (June 2008)
  2795 -------------------------------
  2796 
  2797 *** General ***
  2798 
  2799 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2800 and updated, with formally checked references as hyperlinks.
  2801 
  2802 * Theory loader: use_thy (and similar operations) no longer set the
  2803 implicit ML context, which was occasionally hard to predict and in
  2804 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2805 provides a proper context already.
  2806 
  2807 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2808 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2809 'use' within a theory file will do the job.
  2810 
  2811 * Name space merge now observes canonical order, i.e. the second space
  2812 is inserted into the first one, while existing entries in the first
  2813 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2814 swap theory imports.
  2815 
  2816 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2817 INCOMPATIBILITY in identifier syntax etc.
  2818 
  2819 * Outer syntax: string tokens no longer admit escaped white space,
  2820 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2821 white space without escapes.
  2822 
  2823 * Outer syntax: string tokens may contain arbitrary character codes
  2824 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2825 "foo_bar".
  2826 
  2827 
  2828 *** Pure ***
  2829 
  2830 * Context-dependent token translations.  Default setup reverts locally
  2831 fixed variables, and adds hilite markup for undeclared frees.
  2832 
  2833 * Unused theorems can be found using the new command 'unused_thms'.
  2834 There are three ways of invoking it:
  2835 
  2836 (1) unused_thms
  2837      Only finds unused theorems in the current theory.
  2838 
  2839 (2) unused_thms thy_1 ... thy_n -
  2840      Finds unused theorems in the current theory and all of its ancestors,
  2841      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2842 
  2843 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2844      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2845      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2846      their ancestors.
  2847 
  2848 In order to increase the readability of the list produced by
  2849 unused_thms, theorems that have been created by a particular instance
  2850 of a theory command such as 'inductive' or 'function' are considered
  2851 to belong to the same "group", meaning that if at least one theorem in
  2852 this group is used, the other theorems in the same group are no longer
  2853 reported as unused.  Moreover, if all theorems in the group are
  2854 unused, only one theorem in the group is displayed.
  2855 
  2856 Note that proof objects have to be switched on in order for
  2857 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2858 usually the case when using Proof General with the default settings).
  2859 
  2860 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2861 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2862 duplicate fact bindings, or even accidental fact duplications.  Note
  2863 that tools may maintain dynamically scoped facts systematically, using
  2864 PureThy.add_thms_dynamic.
  2865 
  2866 * Command 'hide' now allows to hide from "fact" name space as well.
  2867 
  2868 * Eliminated destructive theorem database, simpset, claset, and
  2869 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2870 update of theories within ML code.
  2871 
  2872 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2873 INCOMPATIBILITY, object-logics depending on former Pure require
  2874 additional setup PureThy.old_appl_syntax_setup; object-logics
  2875 depending on former CPure need to refer to Pure.
  2876 
  2877 * Commands 'use' and 'ML' are now purely functional, operating on
  2878 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2879 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2880 INCOMPATIBILITY.
  2881 
  2882 * Command 'setup': discontinued implicit version with ML reference.
  2883 
  2884 * Instantiation target allows for simultaneous specification of class
  2885 instance operations together with an instantiation proof.
  2886 Type-checking phase allows to refer to class operations uniformly.
  2887 See src/HOL/Complex/Complex.thy for an Isar example and
  2888 src/HOL/Library/Eval.thy for an ML example.
  2889 
  2890 * Indexing of literal facts: be more serious about including only
  2891 facts from the visible specification/proof context, but not the
  2892 background context (locale etc.).  Affects `prop` notation and method
  2893 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2894 situations.
  2895 
  2896 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2897 "(open)" option, which used to expose internal bound variables to the
  2898 proof text.
  2899 
  2900 * Isar statements: removed obsolete case "rule_context".
  2901 INCOMPATIBILITY, better use explicit fixes/assumes.
  2902 
  2903 * Locale proofs: default proof step now includes 'unfold_locales';
  2904 hence 'proof' without argument may be used to unfold locale
  2905 predicates.
  2906 
  2907 
  2908 *** Document preparation ***
  2909 
  2910 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2911 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2912 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2913 spot); renamed link color from "darkblue" to "linkcolor" (default
  2914 value unchanged, can be redefined via \definecolor); no longer sets
  2915 "a4paper" option (unnecessary or even intrusive).
  2916 
  2917 * Antiquotation @{lemma A method} proves proposition A by the given
  2918 method (either a method name or a method name plus (optional) method
  2919 arguments in parentheses) and prints A just like @{prop A}.
  2920 
  2921 
  2922 *** HOL ***
  2923 
  2924 * New primrec package.  Specification syntax conforms in style to
  2925 definition/function/....  No separate induction rule is provided.  The
  2926 "primrec" command distinguishes old-style and new-style specifications
  2927 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2928 When adjusting theories, beware: constants stemming from new-style
  2929 primrec specifications have authentic syntax.
  2930 
  2931 * Metis prover is now an order of magnitude faster, and also works
  2932 with multithreading.
  2933 
  2934 * Metis: the maximum number of clauses that can be produced from a
  2935 theorem is now given by the attribute max_clauses.  Theorems that
  2936 exceed this number are ignored, with a warning printed.
  2937 
  2938 * Sledgehammer no longer produces structured proofs by default. To
  2939 enable, declare [[sledgehammer_full = true]].  Attributes
  2940 reconstruction_modulus, reconstruction_sorts renamed
  2941 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2942 
  2943 * Method "induct_scheme" derives user-specified induction rules
  2944 from well-founded induction and completeness of patterns. This factors
  2945 out some operations that are done internally by the function package
  2946 and makes them available separately.  See
  2947 src/HOL/ex/Induction_Scheme.thy for examples.
  2948 
  2949 * More flexible generation of measure functions for termination
  2950 proofs: Measure functions can be declared by proving a rule of the
  2951 form "is_measure f" and giving it the [measure_function] attribute.
  2952 The "is_measure" predicate is logically meaningless (always true), and
  2953 just guides the heuristic.  To find suitable measure functions, the
  2954 termination prover sets up the goal "is_measure ?f" of the appropriate
  2955 type and generates all solutions by prolog-style backwards proof using
  2956 the declared rules.
  2957 
  2958 This setup also deals with rules like 
  2959 
  2960   "is_measure f ==> is_measure (list_size f)"
  2961 
  2962 which accommodates nested datatypes that recurse through lists.
  2963 Similar rules are predeclared for products and option types.
  2964 
  2965 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2966 
  2967   INCOMPATIBILITIES:
  2968 
  2969   - Definitions of overloaded constants on sets have to be replaced by
  2970     definitions on => and bool.
  2971 
  2972   - Some definitions of overloaded operators on sets can now be proved
  2973     using the definitions of the operators on => and bool.  Therefore,
  2974     the following theorems have been renamed:
  2975 
  2976       subset_def   -> subset_eq
  2977       psubset_def  -> psubset_eq
  2978       set_diff_def -> set_diff_eq
  2979       Compl_def    -> Compl_eq
  2980       Sup_set_def  -> Sup_set_eq
  2981       Inf_set_def  -> Inf_set_eq
  2982       sup_set_def  -> sup_set_eq
  2983       inf_set_def  -> inf_set_eq
  2984 
  2985   - Due to the incompleteness of the HO unification algorithm, some
  2986     rules such as subst may require manual instantiation, if some of
  2987     the unknowns in the rule is a set.
  2988 
  2989   - Higher order unification and forward proofs:
  2990     The proof pattern
  2991 
  2992       have "P (S::'a set)" <...>
  2993       then have "EX S. P S" ..
  2994 
  2995     no longer works (due to the incompleteness of the HO unification
  2996     algorithm) and must be replaced by the pattern
  2997 
  2998       have "EX S. P S"
  2999       proof
  3000         show "P S" <...>
  3001       qed
  3002 
  3003   - Calculational reasoning with subst (or similar rules):
  3004     The proof pattern
  3005 
  3006       have "P (S::'a set)" <...>
  3007       also have "S = T" <...>
  3008       finally have "P T" .
  3009 
  3010     no longer works (for similar reasons as the previous example) and
  3011     must be replaced by something like
  3012 
  3013       have "P (S::'a set)" <...>
  3014       moreover have "S = T" <...>
  3015       ultimately have "P T" by simp
  3016 
  3017   - Tactics or packages written in ML code:
  3018     Code performing pattern matching on types via
  3019 
  3020       Type ("set", [T]) => ...
  3021 
  3022     must be rewritten. Moreover, functions like strip_type or
  3023     binder_types no longer return the right value when applied to a
  3024     type of the form
  3025 
  3026       T1 => ... => Tn => U => bool
  3027 
  3028     rather than
  3029 
  3030       T1 => ... => Tn => U set
  3031 
  3032 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3033 Wellfounded_Relations to theory Wellfounded.
  3034 
  3035 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3036 
  3037 * Class finite no longer treats UNIV as class parameter.  Use class
  3038 enum from theory Library/Enum instead to achieve a similar effect.
  3039 INCOMPATIBILITY.
  3040 
  3041 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3042 and "Cons".  INCOMPATIBILITY.
  3043 
  3044 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3045 Potential INCOMPATIBILITY.
  3046 
  3047 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3048 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3049 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3050 
  3051 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3052 the same name in theory Orderings:
  3053 
  3054   less_trans
  3055   less_linear
  3056   le_imp_less_or_eq
  3057   le_less_trans
  3058   less_le_trans
  3059   less_not_sym
  3060   less_asym
  3061 
  3062 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3063 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3064 and different variable names.
  3065 
  3066 * Library/Option_ord.thy: Canonical order on option type.
  3067 
  3068 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3069 finite maps.
  3070 
  3071 * Library/Countable.thy: Type class for countable types.
  3072 
  3073 * Theory Int: The representation of numerals has changed.  The infix
  3074 operator BIT and the bit datatype with constructors B0 and B1 have
  3075 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3076 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3077 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3078 accordingly.
  3079 
  3080 * Theory Nat: definition of <= and < on natural numbers no longer
  3081 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3082 le_def and less_def have disappeared.  Consider lemmas not_less
  3083 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3084 
  3085 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3086 (whose purpose mainly is for various fold_set functionals) have been
  3087 abandoned in favor of the existing algebraic classes
  3088 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3089 lower_semilattice (resp. upper_semilattice) and linorder.
  3090 INCOMPATIBILITY.
  3091 
  3092 * Theory Transitive_Closure: induct and cases rules now declare proper
  3093 case_names ("base" and "step").  INCOMPATIBILITY.
  3094 
  3095 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3096 lattices.  The form set-specific version is available as
  3097 Inductive.lfp_ordinal_induct_set.
  3098 
  3099 * Renamed theorems "power.simps" to "power_int.simps".
  3100 INCOMPATIBILITY.
  3101 
  3102 * Class semiring_div provides basic abstract properties of semirings
  3103 with division and modulo operations.  Subsumes former class dvd_mod.
  3104 
  3105 * Merged theories IntDef, Numeral and IntArith into unified theory
  3106 Int.  INCOMPATIBILITY.
  3107 
  3108 * Theory Library/Code_Index: type "index" now represents natural
  3109 numbers rather than integers.  INCOMPATIBILITY.
  3110 
  3111 * New class "uminus" with operation "uminus" (split of from class
  3112 "minus" which now only has operation "minus", binary).
  3113 INCOMPATIBILITY.
  3114 
  3115 * Constants "card", "internal_split", "option_map" now with authentic
  3116 syntax.  INCOMPATIBILITY.
  3117 
  3118 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3119 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3120 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3121 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3122 Sup_set_def, le_def, less_def, option_map_def now with object
  3123 equality.  INCOMPATIBILITY.
  3124 
  3125 * Records. Removed K_record, and replaced it by pure lambda term
  3126 %x. c. The simplifier setup is now more robust against eta expansion.
  3127 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3128 
  3129 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3130 
  3131 * Library/ListVector: new theory of arithmetic vector operations.
  3132 
  3133 * Library/Order_Relation: new theory of various orderings as sets of
  3134 pairs.  Defines preorders, partial orders, linear orders and
  3135 well-orders on sets and on types.
  3136 
  3137 
  3138 *** ZF ***
  3139 
  3140 * Renamed some theories to allow to loading both ZF and HOL in the
  3141 same session:
  3142 
  3143   Datatype  -> Datatype_ZF
  3144   Inductive -> Inductive_ZF
  3145   Int       -> Int_ZF
  3146   IntDiv    -> IntDiv_ZF
  3147   Nat       -> Nat_ZF
  3148   List      -> List_ZF
  3149   Main      -> Main_ZF
  3150 
  3151 INCOMPATIBILITY: ZF theories that import individual theories below
  3152 Main might need to be adapted.  Regular theory Main is still
  3153 available, as trivial extension of Main_ZF.
  3154 
  3155 
  3156 *** ML ***
  3157 
  3158 * ML within Isar: antiquotation @{const name} or @{const
  3159 name(typargs)} produces statically-checked Const term.
  3160 
  3161 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3162 (of the same name).  Removed obsolete print command.
  3163 
  3164 * Removed obsolete "use_legacy_bindings" function.
  3165 
  3166 * The ``print mode'' is now a thread-local value derived from a global
  3167 template (the former print_mode reference), thus access becomes
  3168 non-critical.  The global print_mode reference is for session
  3169 management only; user-code should use print_mode_value,
  3170 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3171 
  3172 * Functions system/system_out provide a robust way to invoke external
  3173 shell commands, with propagation of interrupts (requires Poly/ML
  3174 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3175 
  3176 
  3177 *** System ***
  3178 
  3179 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3180 in accordance with Proof General 3.7, which prefers GNU emacs.
  3181 
  3182 * isatool tty runs Isabelle process with plain tty interaction;
  3183 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3184 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3185 
  3186 * isatool browser now works with Cygwin as well, using general
  3187 "javapath" function defined in Isabelle process environment.
  3188 
  3189 * YXML notation provides a simple and efficient alternative to
  3190 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3191 isatool yxml as described in the Isabelle system manual.
  3192 
  3193 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3194 provides general wrapper for managing an Isabelle process in a robust
  3195 fashion, with ``cooked'' output from stdin/stderr.
  3196 
  3197 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3198 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3199 
  3200 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3201 way of changing the user's settings is via
  3202 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3203 script.
  3204 
  3205 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3206 cores of the underlying machine, which is a good starting point for
  3207 optimal performance tuning.  The corresponding usedir option -M allows
  3208 "max" as an alias for "0".  WARNING: does not work on certain versions
  3209 of Mac OS (with Poly/ML 5.1).
  3210 
  3211 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3212 adverse effect of Isabelle flooding interactive front-ends (notably
  3213 ProofGeneral / XEmacs).
  3214 
  3215 
  3216 
  3217 New in Isabelle2007 (November 2007)
  3218 -----------------------------------
  3219 
  3220 *** General ***
  3221 
  3222 * More uniform information about legacy features, notably a
  3223 warning/error of "Legacy feature: ...", depending on the state of the
  3224 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3225 legacy features will disappear eventually.
  3226 
  3227 * Theory syntax: the header format ``theory A = B + C:'' has been
  3228 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3229 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3230 
  3231 * Theory syntax: the old non-Isar theory file format has been
  3232 discontinued altogether.  Note that ML proof scripts may still be used
  3233 with Isar theories; migration is usually quite simple with the ML
  3234 function use_legacy_bindings.  INCOMPATIBILITY.
  3235 
  3236 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3237 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3238 quotes.
  3239 
  3240 * Theory loader: be more serious about observing the static theory
  3241 header specifications (including optional directories), but not the
  3242 accidental file locations of previously successful loads.  The strict
  3243 update policy of former update_thy is now already performed by
  3244 use_thy, so the former has been removed; use_thys updates several
  3245 theories simultaneously, just as 'imports' within a theory header
  3246 specification, but without merging the results.  Potential
  3247 INCOMPATIBILITY: may need to refine theory headers and commands
  3248 ROOT.ML which depend on load order.
  3249 
  3250 * Theory loader: optional support for content-based file
  3251 identification, instead of the traditional scheme of full physical
  3252 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3253 (cf. the system manual).  The new scheme allows to work with
  3254 non-finished theories in persistent session images, such that source
  3255 files may be moved later on without requiring reloads.
  3256 
  3257 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3258 file (with the same base name as the theory) are considered a legacy
  3259 feature, which will disappear eventually. Even now, the theory loader
  3260 no longer maintains dependencies on such files.
  3261 
  3262 * Syntax: the scope for resolving ambiguities via type-inference is
  3263 now limited to individual terms, instead of whole simultaneous
  3264 specifications as before. This greatly reduces the complexity of the
  3265 syntax module and improves flexibility by separating parsing and
  3266 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3267 'fixes' etc.) are required in rare situations.
  3268 
  3269 * Syntax: constants introduced by new-style packages ('definition',
  3270 'abbreviation' etc.) are passed through the syntax module in
  3271 ``authentic mode''. This means that associated mixfix annotations
  3272 really stick to such constants, independently of potential name space
  3273 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3274 trees are represented slightly differently, may need to adapt syntax
  3275 translations accordingly. Use CONST marker in 'translations' and
  3276 @{const_syntax} antiquotation in 'parse_translation' etc.
  3277 
  3278 * Legacy goal package: reduced interface to the bare minimum required
  3279 to keep existing proof scripts running.  Most other user-level
  3280 functions are now part of the OldGoals structure, which is *not* open
  3281 by default (consider isatool expandshort before open OldGoals).
  3282 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3283 these tend to cause confusion about the actual goal (!) context being
  3284 used here, which is not necessarily the same as the_context().
  3285 
  3286 * Command 'find_theorems': supports "*" wild-card in "name:"
  3287 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3288 support a specific search form (see ProofGeneral/CHANGES).
  3289 
  3290 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3291 by default, which means that "prems" (and also "fixed variables") are
  3292 suppressed from proof state output.  Note that the ProofGeneral
  3293 settings mechanism allows to change and save options persistently, but
  3294 older versions of Isabelle will fail to start up if a negative prems
  3295 limit is imposed.
  3296 
  3297 * Local theory targets may be specified by non-nested blocks of
  3298 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3299 contain definitions, theorems etc., including any derived mechanism
  3300 that has been implemented on top of these primitives.  This concept
  3301 generalizes the existing ``theorem (in ...)'' towards more versatility
  3302 and scalability.
  3303 
  3304 * Proof General interface: proper undo of final 'end' command;
  3305 discontinued Isabelle/classic mode (ML proof scripts).
  3306 
  3307 
  3308 *** Document preparation ***
  3309 
  3310 * Added antiquotation @{theory name} which prints the given name,
  3311 after checking that it refers to a valid ancestor theory in the
  3312 current context.
  3313 
  3314 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3315 check the given source text as ML type/structure, printing verbatim.
  3316 
  3317 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3318 "c args == rhs" given in the current context.  (Any number of
  3319 arguments may be given on the LHS.)
  3320 
  3321 
  3322 *** Pure ***
  3323 
  3324 * The 'class' package offers a combination of axclass and locale to
  3325 achieve Haskell-like type classes in Isabelle.  Definitions and
  3326 theorems within a class context produce both relative results (with
  3327 implicit parameters according to the locale context), and polymorphic
  3328 constants with qualified polymorphism (according to the class
  3329 context).  Within the body context of a 'class' target, a separate
  3330 syntax layer ("user space type system") takes care of converting
  3331 between global polymorphic consts and internal locale representation.
  3332 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3333 "isatool doc classes" provides a tutorial.
  3334 
  3335 * Generic code generator framework allows to generate executable
  3336 code for ML and Haskell (including Isabelle classes).  A short usage
  3337 sketch:
  3338 
  3339     internal compilation:
  3340         export_code <list of constants (term syntax)> in SML
  3341     writing SML code to a file:
  3342         export_code <list of constants (term syntax)> in SML <filename>
  3343     writing OCaml code to a file:
  3344         export_code <list of constants (term syntax)> in OCaml <filename>
  3345     writing Haskell code to a bunch of files:
  3346         export_code <list of constants (term syntax)> in Haskell <filename>
  3347 
  3348     evaluating closed propositions to True/False using code generation:
  3349         method ``eval''
  3350 
  3351 Reasonable default setup of framework in HOL.
  3352 
  3353 Theorem attributs for selecting and transforming function equations theorems:
  3354 
  3355     [code fun]:        select a theorem as function equation for a specific constant
  3356     [code fun del]:    deselect a theorem as function equation for a specific constant
  3357     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3358     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3359 
  3360 User-defined serializations (target in {SML, OCaml, Haskell}):
  3361 
  3362     code_const <and-list of constants (term syntax)>
  3363       {(target) <and-list of const target syntax>}+
  3364 
  3365     code_type <and-list of type constructors>
  3366       {(target) <and-list of type target syntax>}+
  3367 
  3368     code_instance <and-list of instances>
  3369       {(target)}+
  3370         where instance ::= <type constructor> :: <class>
  3371 
  3372     code_class <and_list of classes>
  3373       {(target) <and-list of class target syntax>}+
  3374         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3375 
  3376 code_instance and code_class only are effective to target Haskell.
  3377 
  3378 For example usage see src/HOL/ex/Codegenerator.thy and
  3379 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3380 generation from Isabelle/HOL theories is available via "isatool doc
  3381 codegen".
  3382 
  3383 * Code generator: consts in 'consts_code' Isar commands are now
  3384 referred to by usual term syntax (including optional type
  3385 annotations).
  3386 
  3387 * Command 'no_translations' removes translation rules from theory
  3388 syntax.
  3389 
  3390 * Overloaded definitions are now actually checked for acyclic
  3391 dependencies.  The overloading scheme is slightly more general than
  3392 that of Haskell98, although Isabelle does not demand an exact
  3393 correspondence to type class and instance declarations.
  3394 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3395 exotic versions of overloading -- at the discretion of the user!
  3396 
  3397 Polymorphic constants are represented via type arguments, i.e. the
  3398 instantiation that matches an instance against the most general
  3399 declaration given in the signature.  For example, with the declaration
  3400 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3401 as c(nat).  Overloading is essentially simultaneous structural
  3402 recursion over such type arguments.  Incomplete specification patterns
  3403 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3404 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3405 Command 'print_theory' outputs the normalized system of recursive
  3406 equations, see section "definitions".
  3407 
  3408 * Configuration options are maintained within the theory or proof
  3409 context (with name and type bool/int/string), providing a very simple
  3410 interface to a poor-man's version of general context data.  Tools may
  3411 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3412 these values using Config.get etc.  Users may change options via an
  3413 associated attribute of the same name.  This form of context
  3414 declaration works particularly well with commands 'declare' or
  3415 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3416 very easy to avoid global references, which would not observe Isar
  3417 toplevel undo/redo and fail to work with multithreading.
  3418 
  3419 Various global ML references of Pure and HOL have been turned into
  3420 configuration options:
  3421 
  3422   Unify.search_bound		unify_search_bound
  3423   Unify.trace_bound		unify_trace_bound
  3424   Unify.trace_simp		unify_trace_simp
  3425   Unify.trace_types		unify_trace_types
  3426   Simplifier.simp_depth_limit	simp_depth_limit
  3427   Blast.depth_limit		blast_depth_limit
  3428   DatatypeProp.dtK		datatype_distinctness_limit
  3429   fast_arith_neq_limit  	fast_arith_neq_limit
  3430   fast_arith_split_limit	fast_arith_split_limit
  3431 
  3432 * Named collections of theorems may be easily installed as context
  3433 data using the functor NamedThmsFun (see also
  3434 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3435 attributes; there is also a toplevel print command.  This facility is
  3436 just a common case of general context data, which is the preferred way
  3437 for anything more complex than just a list of facts in canonical
  3438 order.
  3439 
  3440 * Isar: command 'declaration' augments a local theory by generic
  3441 declaration functions written in ML.  This enables arbitrary content
  3442 being added to the context, depending on a morphism that tells the
  3443 difference of the original declaration context wrt. the application
  3444 context encountered later on.
  3445 
  3446 * Isar: proper interfaces for simplification procedures.  Command
  3447 'simproc_setup' declares named simprocs (with match patterns, and body
  3448 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3449 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3450 
  3451 * Isar: an extra pair of brackets around attribute declarations
  3452 abbreviates a theorem reference involving an internal dummy fact,
  3453 which will be ignored later --- only the effect of the attribute on
  3454 the background context will persist.  This form of in-place
  3455 declarations is particularly useful with commands like 'declare' and
  3456 'using', for example ``have A using [[simproc a]] by simp''.
  3457 
  3458 * Isar: method "assumption" (and implicit closing of subproofs) now
  3459 takes simple non-atomic goal assumptions into account: after applying
  3460 an assumption as a rule the resulting subgoals are solved by atomic
  3461 assumption steps.  This is particularly useful to finish 'obtain'
  3462 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3463 without referring to the original premise "!!x. P x ==> thesis" in the
  3464 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3465 more permissive.
  3466 
  3467 * Isar: implicit use of prems from the Isar proof context is
  3468 considered a legacy feature.  Common applications like ``have A .''
  3469 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3470 referencing facts explicitly here improves readability and
  3471 maintainability of proof texts.
  3472 
  3473 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3474 the obtained context from the course of reasoning!  For example:
  3475 
  3476   assume "EX x y. A x & B y"   -- "any previous fact"
  3477   then guess x and y by clarify
  3478 
  3479 This technique is potentially adventurous, depending on the facts and
  3480 proof tools being involved here.
  3481 
  3482 * Isar: known facts from the proof context may be specified as literal
  3483 propositions, using ASCII back-quote syntax.  This works wherever
  3484 named facts used to be allowed so far, in proof commands, proof
  3485 methods, attributes etc.  Literal facts are retrieved from the context
  3486 according to unification of type and term parameters.  For example,
  3487 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3488 theorems in the current context, then these are valid literal facts:
  3489 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3490 
  3491 There is also a proof method "fact" which does the same composition
  3492 for explicit goal states, e.g. the following proof texts coincide with
  3493 certain special cases of literal facts:
  3494 
  3495   have "A" by fact                 ==  note `A`
  3496   have "A ==> B" by fact           ==  note `A ==> B`
  3497   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3498   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3499 
  3500 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3501 outer syntax.  Thus symbolic identifiers may be used without
  3502 additional white space in declarations like this: ``assume *: A''.
  3503 
  3504 * Isar: 'print_facts' prints all local facts of the current context,
  3505 both named and unnamed ones.
  3506 
  3507 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3508 
  3509   def x == "t" and y == "u"
  3510 
  3511 * Isar: added command 'unfolding', which is structurally similar to
  3512 'using', but affects both the goal state and facts by unfolding given
  3513 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3514 'unfolded' attribute may be replaced by first-class proof text.
  3515 
  3516 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3517 and command 'unfolding' now all support object-level equalities
  3518 (potentially conditional).  The underlying notion of rewrite rule is
  3519 analogous to the 'rule_format' attribute, but *not* that of the
  3520 Simplifier (which is usually more generous).
  3521 
  3522 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3523 premises of a theorem by n. Useful in conjunction with drule.
  3524 
  3525 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3526 method expression within a sandbox consisting of the first N
  3527 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3528 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3529 simplifies all new goals that emerge from applying rule foo to the
  3530 originally first one.
  3531 
  3532 * Isar: schematic goals are no longer restricted to higher-order
  3533 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3534 expected.
  3535 
  3536 * Isar: the conclusion of a long theorem statement is now either
  3537 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3538 (essentially a disjunction of cases with local parameters and
  3539 assumptions).  The latter allows to express general elimination rules
  3540 adequately; in this notation common elimination rules look like this:
  3541 
  3542   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3543     assumes "EX x. P x"
  3544     obtains x where "P x"
  3545 
  3546   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3547     assumes "A & B"
  3548     obtains A and B
  3549 
  3550   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3551     assumes "A | B"
  3552     obtains
  3553       A
  3554     | B
  3555 
  3556 The subsequent classical rules even refer to the formal "thesis"
  3557 explicitly:
  3558 
  3559   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3560     obtains "~ thesis"
  3561 
  3562   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3563     obtains "thesis ==> something"
  3564 
  3565 The actual proof of an 'obtains' statement is analogous to that of the
  3566 Isar proof element 'obtain', only that there may be several cases.
  3567 Optional case names may be specified in parentheses; these will be
  3568 available both in the present proof and as annotations in the
  3569 resulting rule, for later use with the 'cases' method (cf. attribute
  3570 case_names).
  3571 
  3572 * Isar: the assumptions of a long theorem statement are available as
  3573 "assms" fact in the proof context.  This is more appropriate than the
  3574 (historical) "prems", which refers to all assumptions of the current
  3575 context, including those from the target locale, proof body etc.
  3576 
  3577 * Isar: 'print_statement' prints theorems from the current theory or
  3578 proof context in long statement form, according to the syntax of a
  3579 top-level lemma.
  3580 
  3581 * Isar: 'obtain' takes an optional case name for the local context
  3582 introduction rule (default "that").
  3583 
  3584 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3585 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3586 to occur.
  3587 
  3588 * Pure: syntax "CONST name" produces a fully internalized constant
  3589 according to the current context.  This is particularly useful for
  3590 syntax translations that should refer to internal constant
  3591 representations independently of name spaces.
  3592 
  3593 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3594 instead of "FOO ". This allows multiple binder declarations to coexist
  3595 in the same context.  INCOMPATIBILITY.
  3596 
  3597 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3598 primitive that also works in a locale context (both for constants and
  3599 fixed variables). Type declaration and internal syntactic representation
  3600 of given constants retrieved from the context. Likewise, the
  3601 'no_notation' command allows to remove given syntax annotations from the
  3602 current context.
  3603 
  3604 * Isar/locales: new derived specification elements 'axiomatization',
  3605 'definition', 'abbreviation', which support type-inference, admit
  3606 object-level specifications (equality, equivalence).  See also the
  3607 isar-ref manual.  Examples:
  3608 
  3609   axiomatization
  3610     eq  (infix "===" 50) where
  3611     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3612 
  3613   definition "f x y = x + y + 1"
  3614   definition g where "g x = f x x"
  3615 
  3616   abbreviation
  3617     neq  (infix "=!=" 50) where
  3618     "x =!= y == ~ (x === y)"
  3619 
  3620 These specifications may be also used in a locale context.  Then the
  3621 constants being introduced depend on certain fixed parameters, and the
  3622 constant name is qualified by the locale base name.  An internal
  3623 abbreviation takes care for convenient input and output, making the
  3624 parameters implicit and using the original short name.  See also
  3625 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3626 entities from a monomorphic theory.
  3627 
  3628 Presently, abbreviations are only available 'in' a target locale, but
  3629 not inherited by general import expressions.  Also note that
  3630 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3631 'translations' in common applications.  The "no_abbrevs" print mode
  3632 prevents folding of abbreviations in term output.
  3633 
  3634 Concrete syntax is attached to specified constants in internal form,
  3635 independently of name spaces.  The parse tree representation is
  3636 slightly different -- use 'notation' instead of raw 'syntax', and
  3637 'translations' with explicit "CONST" markup to accommodate this.
  3638 
  3639 * Pure/Isar: unified syntax for new-style specification mechanisms
  3640 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3641 full type inference and dummy patterns ("_").  For example:
  3642 
  3643   definition "K x _ = x"
  3644 
  3645   inductive conj for A B
  3646   where "A ==> B ==> conj A B"
  3647 
  3648 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3649 the current context.  Print mode "no_abbrevs" prevents inversion of
  3650 abbreviations on output.
  3651 
  3652 * Isar/locales: improved parameter handling: use of locales "var" and
  3653 "struct" no longer necessary; - parameter renamings are no longer
  3654 required to be injective.  For example, this allows to define
  3655 endomorphisms as locale endom = homom mult mult h.
  3656 
  3657 * Isar/locales: changed the way locales with predicates are defined.
  3658 Instead of accumulating the specification, the imported expression is
  3659 now an interpretation.  INCOMPATIBILITY: different normal form of
  3660 locale expressions.  In particular, in interpretations of locales with
  3661 predicates, goals repesenting already interpreted fragments are not
  3662 removed automatically.  Use methods `intro_locales' and
  3663 `unfold_locales'; see below.
  3664 
  3665 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3666 provide backward reasoning on locales predicates.  The methods are
  3667 aware of interpretations and discharge corresponding goals.
  3668 `intro_locales' is less aggressive then `unfold_locales' and does not
  3669 unfold predicates to assumptions.
  3670 
  3671 * Isar/locales: the order in which locale fragments are accumulated
  3672 has changed.  This enables to override declarations from fragments due
  3673 to interpretations -- for example, unwanted simp rules.
  3674 
  3675 * Isar/locales: interpretation in theories and proof contexts has been
  3676 extended.  One may now specify (and prove) equations, which are
  3677 unfolded in interpreted theorems.  This is useful for replacing
  3678 defined concepts (constants depending on locale parameters) by
  3679 concepts already existing in the target context.  Example:
  3680 
  3681   interpretation partial_order ["op <= :: [int, int] => bool"]
  3682     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3683 
  3684 Typically, the constant `partial_order.less' is created by a
  3685 definition specification element in the context of locale
  3686 partial_order.
  3687 
  3688 * Method "induct": improved internal context management to support
  3689 local fixes and defines on-the-fly. Thus explicit meta-level
  3690 connectives !!  and ==> are rarely required anymore in inductive goals
  3691 (using object-logic connectives for this purpose has been long
  3692 obsolete anyway). Common proof patterns are explained in
  3693 src/HOL/Induct/Common_Patterns.thy, see also
  3694 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3695 examples.
  3696 
  3697 * Method "induct": improved handling of simultaneous goals. Instead of
  3698 introducing object-level conjunction, the statement is now split into
  3699 several conclusions, while the corresponding symbolic cases are nested
  3700 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3701 see src/HOL/Induct/Common_Patterns.thy, for example.
  3702 
  3703 * Method "induct": mutual induction rules are now specified as a list
  3704 of rule sharing the same induction cases. HOL packages usually provide
  3705 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3706 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3707 mutual induction rules differently, i.e. like this:
  3708 
  3709   (induct rule: foo_bar.inducts)
  3710   (induct set: foo bar)
  3711   (induct pred: foo bar)
  3712   (induct type: foo bar)
  3713 
  3714 The ML function ProjectRule.projections turns old-style rules into the
  3715 new format.
  3716 
  3717 * Method "coinduct": dual of induction, see
  3718 src/HOL/Library/Coinductive_List.thy for various examples.
  3719 
  3720 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3721 considered a legacy feature.
  3722 
  3723 * Attribute "symmetric" produces result with standardized schematic
  3724 variables (index 0).  Potential INCOMPATIBILITY.
  3725 
  3726 * Simplifier: by default the simplifier trace only shows top level
  3727 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3728 default. Thus there is less danger of being flooded by the trace. The
  3729 trace indicates where parts have been suppressed.
  3730   
  3731 * Provers/classical: removed obsolete classical version of elim_format
  3732 attribute; classical elim/dest rules are now treated uniformly when
  3733 manipulating the claset.
  3734 
  3735 * Provers/classical: stricter checks to ensure that supplied intro,
  3736 dest and elim rules are well-formed; dest and elim rules must have at
  3737 least one premise.
  3738 
  3739 * Provers/classical: attributes dest/elim/intro take an optional
  3740 weight argument for the rule (just as the Pure versions).  Weights are
  3741 ignored by automated tools, but determine the search order of single
  3742 rule steps.
  3743 
  3744 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3745 where the body does not mention the bound variable.  Note that dummy
  3746 patterns implicitly depend on their context of bounds, which makes
  3747 "{_. _}" match any set comprehension as expected.  Potential
  3748 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3749 constant "_idtdummy" in the binding position.
  3750 
  3751 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3752 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3753 for example "A -> B" => "Pi A (%_. B)".
  3754 
  3755 * Pure: 'class_deps' command visualizes the subclass relation, using
  3756 the graph browser tool.
  3757 
  3758 * Pure: 'print_theory' now suppresses certain internal declarations by
  3759 default; use '!' option for full details.
  3760 
  3761 
  3762 *** HOL ***
  3763 
  3764 * Method "metis" proves goals by applying the Metis general-purpose
  3765 resolution prover (see also http://gilith.com/software/metis/).
  3766 Examples are in the directory MetisExamples.  WARNING: the
  3767 Isabelle/HOL-Metis integration does not yet work properly with
  3768 multi-threading.
  3769   
  3770 * Command 'sledgehammer' invokes external automatic theorem provers as
  3771 background processes.  It generates calls to the "metis" method if
  3772 successful. These can be pasted into the proof.  Users do not have to
  3773 wait for the automatic provers to return.  WARNING: does not really
  3774 work with multi-threading.
  3775 
  3776 * New "auto_quickcheck" feature tests outermost goal statements for
  3777 potential counter-examples.  Controlled by ML references
  3778 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3779 5000 milliseconds).  Fails silently if statements is outside of
  3780 executable fragment, or any other codgenerator problem occurs.
  3781 
  3782 * New constant "undefined" with axiom "undefined x = undefined".
  3783 
  3784 * Added class "HOL.eq", allowing for code generation with polymorphic
  3785 equality.
  3786 
  3787 * Some renaming of class constants due to canonical name prefixing in
  3788 the new 'class' package:
  3789 
  3790     HOL.abs ~> HOL.abs_class.abs
  3791     HOL.divide ~> HOL.divide_class.divide
  3792     0 ~> HOL.zero_class.zero
  3793     1 ~> HOL.one_class.one
  3794     op + ~> HOL.plus_class.plus
  3795     op - ~> HOL.minus_class.minus
  3796     uminus ~> HOL.minus_class.uminus
  3797     op * ~> HOL.times_class.times
  3798     op < ~> HOL.ord_class.less
  3799     op <= > HOL.ord_class.less_eq
  3800     Nat.power ~> Power.power_class.power
  3801     Nat.size ~> Nat.size_class.size
  3802     Numeral.number_of ~> Numeral.number_class.number_of
  3803     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3804     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3805     Orderings.min ~> Orderings.ord_class.min
  3806     Orderings.max ~> Orderings.ord_class.max
  3807     Divides.op div ~> Divides.div_class.div
  3808     Divides.op mod ~> Divides.div_class.mod
  3809     Divides.op dvd ~> Divides.div_class.dvd
  3810 
  3811 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3812 
  3813 a) User-defined constants using any of the names "plus", "minus",
  3814 "times", "less" or "less_eq". The standard syntax translations for
  3815 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3816 names.
  3817 
  3818 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3819 INCOMPATIBILITY: use more specific names.
  3820 
  3821 c) Permutative equations (e.g. "a + b = b + a")
  3822 Since the change of names also changes the order of terms, permutative
  3823 rewrite rules may get applied in a different order. Experience shows
  3824 that this is rarely the case (only two adaptions in the whole Isabelle
  3825 distribution).  INCOMPATIBILITY: rewrite proofs
  3826 
  3827 d) ML code directly refering to constant names
  3828 This in general only affects hand-written proof tactics, simprocs and
  3829 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3830 Consider using @{const_name} antiquotation.
  3831 
  3832 * New class "default" with associated constant "default".
  3833 
  3834 * Function "sgn" is now overloaded and available on int, real, complex
  3835 (and other numeric types), using class "sgn".  Two possible defs of
  3836 sgn are given as equational assumptions in the classes sgn_if and
  3837 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3838 INCOMPATIBILITY.
  3839 
  3840 * Locale "partial_order" now unified with class "order" (cf. theory
  3841 Orderings), added parameter "less".  INCOMPATIBILITY.
  3842 
  3843 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3844 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3845 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3846 
  3847 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3848 changed order of proof goals in instance proofs.
  3849 
  3850 * The transitivity reasoner for partial and linear orders is set up
  3851 for classes "order" and "linorder".  Instances of the reasoner are available
  3852 in all contexts importing or interpreting the corresponding locales.
  3853 Method "order" invokes the reasoner separately; the reasoner
  3854 is also integrated with the Simplifier as a solver.  Diagnostic
  3855 command 'print_orders' shows the available instances of the reasoner
  3856 in the current context.
  3857 
  3858 * Localized monotonicity predicate in theory "Orderings"; integrated
  3859 lemmas max_of_mono and min_of_mono with this predicate.
  3860 INCOMPATIBILITY.
  3861 
  3862 * Formulation of theorem "dense" changed slightly due to integration
  3863 with new class dense_linear_order.
  3864 
  3865 * Uniform lattice theory development in HOL.
  3866 
  3867     constants "meet" and "join" now named "inf" and "sup"
  3868     constant "Meet" now named "Inf"
  3869 
  3870     classes "meet_semilorder" and "join_semilorder" now named
  3871       "lower_semilattice" and "upper_semilattice"
  3872     class "lorder" now named "lattice"
  3873     class "comp_lat" now named "complete_lattice"
  3874 
  3875     Instantiation of lattice classes allows explicit definitions
  3876     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3877 
  3878   INCOMPATIBILITY.  Theorem renames:
  3879 
  3880     meet_left_le            ~> inf_le1
  3881     meet_right_le           ~> inf_le2
  3882     join_left_le            ~> sup_ge1
  3883     join_right_le           ~> sup_ge2
  3884     meet_join_le            ~> inf_sup_ord
  3885     le_meetI                ~> le_infI
  3886     join_leI                ~> le_supI
  3887     le_meet                 ~> le_inf_iff
  3888     le_join                 ~> ge_sup_conv
  3889     meet_idempotent         ~> inf_idem
  3890     join_idempotent         ~> sup_idem
  3891     meet_comm               ~> inf_commute
  3892     join_comm               ~> sup_commute
  3893     meet_leI1               ~> le_infI1
  3894     meet_leI2               ~> le_infI2
  3895     le_joinI1               ~> le_supI1
  3896     le_joinI2               ~> le_supI2
  3897     meet_assoc              ~> inf_assoc
  3898     join_assoc              ~> sup_assoc
  3899     meet_left_comm          ~> inf_left_commute
  3900     meet_left_idempotent    ~> inf_left_idem
  3901     join_left_comm          ~> sup_left_commute
  3902     join_left_idempotent    ~> sup_left_idem
  3903     meet_aci                ~> inf_aci
  3904     join_aci                ~> sup_aci
  3905     le_def_meet             ~> le_iff_inf
  3906     le_def_join             ~> le_iff_sup
  3907     join_absorp2            ~> sup_absorb2
  3908     join_absorp1            ~> sup_absorb1
  3909     meet_absorp1            ~> inf_absorb1
  3910     meet_absorp2            ~> inf_absorb2
  3911     meet_join_absorp        ~> inf_sup_absorb
  3912     join_meet_absorp        ~> sup_inf_absorb
  3913     distrib_join_le         ~> distrib_sup_le
  3914     distrib_meet_le         ~> distrib_inf_le
  3915 
  3916     add_meet_distrib_left   ~> add_inf_distrib_left
  3917     add_join_distrib_left   ~> add_sup_distrib_left
  3918     is_join_neg_meet        ~> is_join_neg_inf
  3919     is_meet_neg_join        ~> is_meet_neg_sup
  3920     add_meet_distrib_right  ~> add_inf_distrib_right
  3921     add_join_distrib_right  ~> add_sup_distrib_right
  3922     add_meet_join_distribs  ~> add_sup_inf_distribs
  3923     join_eq_neg_meet        ~> sup_eq_neg_inf
  3924     meet_eq_neg_join        ~> inf_eq_neg_sup
  3925     add_eq_meet_join        ~> add_eq_inf_sup
  3926     meet_0_imp_0            ~> inf_0_imp_0
  3927     join_0_imp_0            ~> sup_0_imp_0
  3928     meet_0_eq_0             ~> inf_0_eq_0
  3929     join_0_eq_0             ~> sup_0_eq_0
  3930     neg_meet_eq_join        ~> neg_inf_eq_sup
  3931     neg_join_eq_meet        ~> neg_sup_eq_inf
  3932     join_eq_if              ~> sup_eq_if
  3933 
  3934     mono_meet               ~> mono_inf
  3935     mono_join               ~> mono_sup
  3936     meet_bool_eq            ~> inf_bool_eq
  3937     join_bool_eq            ~> sup_bool_eq
  3938     meet_fun_eq             ~> inf_fun_eq
  3939     join_fun_eq             ~> sup_fun_eq
  3940     meet_set_eq             ~> inf_set_eq
  3941     join_set_eq             ~> sup_set_eq
  3942     meet1_iff               ~> inf1_iff
  3943     meet2_iff               ~> inf2_iff
  3944     meet1I                  ~> inf1I
  3945     meet2I                  ~> inf2I
  3946     meet1D1                 ~> inf1D1
  3947     meet2D1                 ~> inf2D1
  3948     meet1D2                 ~> inf1D2
  3949     meet2D2                 ~> inf2D2
  3950     meet1E                  ~> inf1E
  3951     meet2E                  ~> inf2E
  3952     join1_iff               ~> sup1_iff
  3953     join2_iff               ~> sup2_iff
  3954     join1I1                 ~> sup1I1
  3955     join2I1                 ~> sup2I1
  3956     join1I1                 ~> sup1I1
  3957     join2I2                 ~> sup1I2
  3958     join1CI                 ~> sup1CI
  3959     join2CI                 ~> sup2CI
  3960     join1E                  ~> sup1E
  3961     join2E                  ~> sup2E
  3962 
  3963     is_meet_Meet            ~> is_meet_Inf
  3964     Meet_bool_def           ~> Inf_bool_def
  3965     Meet_fun_def            ~> Inf_fun_def
  3966     Meet_greatest           ~> Inf_greatest
  3967     Meet_lower              ~> Inf_lower
  3968     Meet_set_def            ~> Inf_set_def
  3969 
  3970     Sup_def                 ~> Sup_Inf
  3971     Sup_bool_eq             ~> Sup_bool_def
  3972     Sup_fun_eq              ~> Sup_fun_def
  3973     Sup_set_eq              ~> Sup_set_def
  3974 
  3975     listsp_meetI            ~> listsp_infI
  3976     listsp_meet_eq          ~> listsp_inf_eq
  3977 
  3978     meet_min                ~> inf_min
  3979     join_max                ~> sup_max
  3980 
  3981 * Added syntactic class "size"; overloaded constant "size" now has
  3982 type "'a::size ==> bool"
  3983 
  3984 * Internal reorganisation of `size' of datatypes: size theorems
  3985 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3986 simplification rules by default!); theorems "prod.size" now named
  3987 "*.size".
  3988 
  3989 * Class "div" now inherits from class "times" rather than "type".
  3990 INCOMPATIBILITY.
  3991 
  3992 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3993 Linorder etc.  have disappeared; operations defined in terms of
  3994 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3995 
  3996 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3997 
  3998 * HOL-Word: New extensive library and type for generic, fixed size
  3999 machine words, with arithemtic, bit-wise, shifting and rotating
  4000 operations, reflection into int, nat, and bool lists, automation for
  4001 linear arithmetic (by automatic reflection into nat or int), including
  4002 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4003 arithmetic type classes, supporting automatic simplification of
  4004 numerals on all operations.
  4005 
  4006 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4007 
  4008 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4009 
  4010 * Code generator library theories:
  4011   - Code_Integer represents HOL integers by big integer literals in target
  4012     languages.
  4013   - Code_Char represents HOL characters by character literals in target
  4014     languages.
  4015   - Code_Char_chr like Code_Char, but also offers treatment of character
  4016     codes; includes Code_Integer.
  4017   - Executable_Set allows to generate code for finite sets using lists.
  4018   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4019     denominator).
  4020   - Executable_Real implements a subset of real numbers, namly those
  4021     representable by rational numbers.
  4022   - Efficient_Nat implements natural numbers by integers, which in general will
  4023     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4024     includes Code_Integer.
  4025   - Code_Index provides an additional datatype index which is mapped to
  4026     target-language built-in integers.
  4027   - Code_Message provides an additional datatype message_string which is isomorphic to
  4028     strings; messages are mapped to target-language strings.
  4029 
  4030 * New package for inductive predicates
  4031 
  4032   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4033 
  4034     inductive
  4035       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4036       for z_1 :: U_1 and ... and z_n :: U_m
  4037     where
  4038       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4039     | ...
  4040 
  4041   with full support for type-inference, rather than
  4042 
  4043     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4044 
  4045     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4046     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4047 
  4048     inductive "s z_1 ... z_m"
  4049     intros
  4050       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4051       ...
  4052 
  4053   For backward compatibility, there is a wrapper allowing inductive
  4054   sets to be defined with the new package via
  4055 
  4056     inductive_set
  4057       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4058       for z_1 :: U_1 and ... and z_n :: U_m
  4059     where
  4060       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4061     | ...
  4062 
  4063   or
  4064 
  4065     inductive_set
  4066       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4067       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4068       for z_1 :: U_1 and ... and z_n :: U_m
  4069     where
  4070       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4071     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4072     | ...
  4073 
  4074   if the additional syntax "p ..." is required.
  4075 
  4076   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4077   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4078 
  4079   INCOMPATIBILITIES:
  4080 
  4081   - Since declaration and definition of inductive sets or predicates
  4082     is no longer separated, abbreviations involving the newly
  4083     introduced sets or predicates must be specified together with the
  4084     introduction rules after the 'where' keyword (see above), rather
  4085     than before the actual inductive definition.
  4086 
  4087   - The variables in induction and elimination rules are now
  4088     quantified in the order of their occurrence in the introduction
  4089     rules, rather than in alphabetical order. Since this may break
  4090     some proofs, these proofs either have to be repaired, e.g. by
  4091     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4092     statements of the form
  4093 
  4094       case (rule_i a_i_1 ... a_i_{k_i})
  4095 
  4096     or the old order of quantification has to be restored by explicitly adding
  4097     meta-level quantifiers in the introduction rules, i.e.
  4098 
  4099       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4100 
  4101   - The format of the elimination rules is now
  4102 
  4103       p z_1 ... z_m x_1 ... x_n ==>
  4104         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4105         ==> ... ==> P
  4106 
  4107     for predicates and
  4108 
  4109       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4110         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4111         ==> ... ==> P
  4112 
  4113     for sets rather than
  4114 
  4115       x : s z_1 ... z_m ==>
  4116         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4117         ==> ... ==> P
  4118 
  4119     This may require terms in goals to be expanded to n-tuples
  4120     (e.g. using case_tac or simplification with the split_paired_all
  4121     rule) before the above elimination rule is applicable.
  4122 
  4123   - The elimination or case analysis rules for (mutually) inductive
  4124     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4125     list of rules "p_1_..._p_k.elims" is no longer available.
  4126 
  4127 * New package "function"/"fun" for general recursive functions,
  4128 supporting mutual and nested recursion, definitions in local contexts,
  4129 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4130 for small examples, and the separate tutorial on the function
  4131 package. The old recdef "package" is still available as before, but
  4132 users are encouraged to use the new package.
  4133 
  4134 * Method "lexicographic_order" automatically synthesizes termination
  4135 relations as lexicographic combinations of size measures. 
  4136 
  4137 * Case-expressions allow arbitrary constructor-patterns (including
  4138 "_") and take their order into account, like in functional
  4139 programming.  Internally, this is translated into nested
  4140 case-expressions; missing cases are added and mapped to the predefined
  4141 constant "undefined". In complicated cases printing may no longer show
  4142 the original input but the internal form. Lambda-abstractions allow
  4143 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4144 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4145 variable.
  4146 
  4147 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4148 is an abbreviation for "of_nat :: nat => int". The simplification
  4149 rules for "of_nat" have been changed to work like "int" did
  4150 previously.  Potential INCOMPATIBILITY:
  4151   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4152   - of_nat_diff and of_nat_mult are no longer default simp rules
  4153 
  4154 * Method "algebra" solves polynomial equations over (semi)rings using
  4155 Groebner bases. The (semi)ring structure is defined by locales and the
  4156 tool setup depends on that generic context. Installing the method for
  4157 a specific type involves instantiating the locale and possibly adding
  4158 declarations for computation on the coefficients.  The method is
  4159 already instantiated for natural numbers and for the axiomatic class
  4160 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4161 CALCULEMUS 2007 for the general principles underlying this
  4162 architecture of context-aware proof-tools.
  4163 
  4164 * Method "ferrack" implements quantifier elimination over
  4165 special-purpose dense linear orders using locales (analogous to
  4166 "algebra"). The method is already installed for class
  4167 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4168 rat, etc.
  4169 
  4170 * Former constant "List.op @" now named "List.append".  Use ML
  4171 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4172 circumvent possible incompatibilities when working on ML level.
  4173 
  4174 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4175 
  4176 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4177 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4178 
  4179 * New syntax for Haskell-like list comprehension (input only), eg.
  4180 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4181 
  4182 * The special syntax for function "filter" has changed from [x :
  4183 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4184 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4185 
  4186 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4187 defined on nat only, as an abbreviation for [a..<Suc b]
  4188 INCOMPATIBILITY.
  4189 
  4190 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4191 
  4192 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4193 
  4194 * New lemma collection field_simps (an extension of ring_simps) for
  4195 manipulating (in)equations involving division. Multiplies with all
  4196 denominators that can be proved to be non-zero (in equations) or
  4197 positive/negative (in inequations).
  4198 
  4199 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4200 have been improved and renamed to ring_simps, group_simps and
  4201 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4202 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4203 
  4204 * Theory Library/Commutative_Ring: switched from recdef to function
  4205 package; constants add, mul, pow now curried.  Infix syntax for
  4206 algebraic operations.
  4207 
  4208 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4209 INCOMPATIBILITY.
  4210 
  4211 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4212 INCOMPATIBILITY.
  4213 
  4214 * HOL/records: generalised field-update to take a function on the
  4215 field rather than the new value: r(|A := x|) is translated to A_update
  4216 (K x) r The K-combinator that is internally used is called K_record.
  4217 INCOMPATIBILITY: Usage of the plain update functions has to be
  4218 adapted.
  4219  
  4220 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4221 * x = 0, which are required for a semiring.  Richer structures do not
  4222 inherit from semiring_0 anymore, because this property is a theorem
  4223 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4224 there is more to prove, but this is mostly trivial.
  4225 
  4226 * Class "recpower" is generalized to arbitrary monoids, not just
  4227 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4228 commutativity or semiring properties additionally.
  4229 
  4230 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4231 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4232 better use 'abbreviation'.
  4233 
  4234 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4235 
  4236 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4237 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4238 significant changes for setting up numeral syntax for types:
  4239   - New constants Numeral.pred and Numeral.succ instead
  4240       of former Numeral.bin_pred and Numeral.bin_succ.
  4241   - Use integer operations instead of bin_add, bin_mult and so on.
  4242   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4243   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4244 
  4245 See src/HOL/Integ/IntArith.thy for an example setup.
  4246 
  4247 * Command 'normal_form' computes the normal form of a term that may
  4248 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4249 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4250 heavy-duty computations because the functions are compiled to ML
  4251 first.  Correspondingly, a method "normalization" is provided.  See
  4252 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4253 
  4254 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4255 25 like -->); output depends on the "iff" print_mode, the default is
  4256 "A = B" (with priority 50).
  4257 
  4258 * Relations less (<) and less_eq (<=) are also available on type bool.
  4259 Modified syntax to disallow nesting without explicit parentheses,
  4260 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4261 INCOMPATIBILITY.
  4262 
  4263 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4264 
  4265 * Relation composition operator "op O" now has precedence 75 and binds
  4266 stronger than union and intersection. INCOMPATIBILITY.
  4267 
  4268 * The old set interval syntax "{m..n(}" (and relatives) has been
  4269 removed.  Use "{m..<n}" (and relatives) instead.
  4270 
  4271 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4272 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4273 ``declare [[simproc del: neq]]''.
  4274 
  4275 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4276 True/False.
  4277 
  4278 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4279 
  4280 * Theorem setsum_mult renamed to setsum_right_distrib.
  4281 
  4282 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4283 ``rule'' method.
  4284 
  4285 * Reimplemented methods "sat" and "satx", with several improvements:
  4286 goals no longer need to be stated as "<prems> ==> False", equivalences
  4287 (i.e. "=" on type bool) are handled, variable names of the form
  4288 "lit_<n>" are no longer reserved, significant speedup.
  4289 
  4290 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4291 zChaff is still supported as well.
  4292 
  4293 * 'inductive' and 'datatype': provide projections of mutual rules,
  4294 bundled as foo_bar.inducts;
  4295 
  4296 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4297 Library.
  4298 
  4299 * Library: moved theory Accessible_Part to main HOL.
  4300 
  4301 * Library: added theory Coinductive_List of potentially infinite lists
  4302 as greatest fixed-point.
  4303 
  4304 * Library: added theory AssocList which implements (finite) maps as
  4305 association lists.
  4306 
  4307 * Method "evaluation" solves goals (i.e. a boolean expression)
  4308 efficiently by compiling it to ML.  The goal is "proved" (via an
  4309 oracle) if it evaluates to True.
  4310 
  4311 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4312 also when invoked by the simplifier.  This results in the Simplifier
  4313 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4314 Configuration option fast_arith_split_limit=0 recovers the old
  4315 behavior.
  4316 
  4317 * Support for hex (0x20) and binary (0b1001) numerals.
  4318 
  4319 * New method: reify eqs (t), where eqs are equations for an
  4320 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4321 parameter, computes a term s::'b and a list xs::'a list and proves the
  4322 theorem I xs s = t. This is also known as reification or quoting. The
  4323 resulting theorem is applied to the subgoal to substitute t with I xs
  4324 s.  If t is omitted, the subgoal itself is reified.
  4325 
  4326 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4327 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4328 where f is supposed to be a computable function (in the sense of code
  4329 generattion). The method uses reify to compute s and xs as above then
  4330 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4331 r and finally gets the theorem t = r, which is again applied to the
  4332 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4333 
  4334 * Reflection: Automatic reification now handels binding, an example is
  4335 available in src/HOL/ex/ReflectionEx.thy
  4336 
  4337 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4338 command 'statespace' that is similar to 'record', but introduces an
  4339 abstract specification based on the locale infrastructure instead of
  4340 HOL types.  This leads to extra flexibility in composing state spaces,
  4341 in particular multiple inheritance and renaming of components.
  4342 
  4343 
  4344 *** HOL-Complex ***
  4345 
  4346 * Hyperreal: Functions root and sqrt are now defined on negative real
  4347 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4348 Nonnegativity side conditions have been removed from many lemmas, so
  4349 that more subgoals may now be solved by simplification; potential
  4350 INCOMPATIBILITY.
  4351 
  4352 * Real: new type classes formalize real normed vector spaces and
  4353 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4354 and norm :: 'a => real.
  4355 
  4356 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4357 reals into other types. The overloaded constant Reals :: 'a set is now
  4358 defined as range of_real; potential INCOMPATIBILITY.
  4359 
  4360 * Real: proper support for ML code generation, including 'quickcheck'.
  4361 Reals are implemented as arbitrary precision rationals.
  4362 
  4363 * Hyperreal: Several constants that previously worked only for the
  4364 reals have been generalized, so they now work over arbitrary vector
  4365 spaces. Type annotations may need to be added in some cases; potential
  4366 INCOMPATIBILITY.
  4367 
  4368   Infinitesimal  :: ('a::real_normed_vector) star set
  4369   HFinite        :: ('a::real_normed_vector) star set
  4370   HInfinite      :: ('a::real_normed_vector) star set
  4371   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4372   monad          :: ('a::real_normed_vector) star => 'a star set
  4373   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4374   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4375   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4376   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4377   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4378   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4379   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4380   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4381   sgn            :: 'a::real_normed_vector => 'a
  4382   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4383 
  4384 * Complex: Some complex-specific constants are now abbreviations for
  4385 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4386 hnorm.  Other constants have been entirely removed in favor of the
  4387 polymorphic versions (INCOMPATIBILITY):
  4388 
  4389   approx        <-- capprox
  4390   HFinite       <-- CFinite
  4391   HInfinite     <-- CInfinite
  4392   Infinitesimal <-- CInfinitesimal
  4393   monad         <-- cmonad
  4394   galaxy        <-- cgalaxy
  4395   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4396   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4397   (ns)deriv     <-- (ns)cderiv
  4398 
  4399 
  4400 *** HOL-Algebra ***
  4401 
  4402 * Formalisation of ideals and the quotient construction over rings.
  4403 
  4404 * Order and lattice theory no longer based on records.
  4405 INCOMPATIBILITY.
  4406 
  4407 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4408 greatest_closed.  INCOMPATIBILITY.
  4409 
  4410 * Method algebra is now set up via an attribute.  For examples see
  4411 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4412 of algebraic structures.
  4413 
  4414 * Renamed theory CRing to Ring.
  4415 
  4416 
  4417 *** HOL-Nominal ***
  4418 
  4419 * Substantial, yet incomplete support for nominal datatypes (binding
  4420 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4421 src/HOL/Nominal/Examples.  Prospective users should consult
  4422 http://isabelle.in.tum.de/nominal/
  4423 
  4424 
  4425 *** ML ***
  4426 
  4427 * ML basics: just one true type int, which coincides with IntInf.int
  4428 (even on SML/NJ).
  4429 
  4430 * ML within Isar: antiquotations allow to embed statically-checked
  4431 formal entities in the source, referring to the context available at
  4432 compile-time.  For example:
  4433 
  4434 ML {* @{sort "{zero,one}"} *}
  4435 ML {* @{typ "'a => 'b"} *}
  4436 ML {* @{term "%x. x"} *}
  4437 ML {* @{prop "x == y"} *}
  4438 ML {* @{ctyp "'a => 'b"} *}
  4439 ML {* @{cterm "%x. x"} *}
  4440 ML {* @{cprop "x == y"} *}
  4441 ML {* @{thm asm_rl} *}
  4442 ML {* @{thms asm_rl} *}
  4443 ML {* @{type_name c} *}
  4444 ML {* @{type_syntax c} *}
  4445 ML {* @{const_name c} *}
  4446 ML {* @{const_syntax c} *}
  4447 ML {* @{context} *}
  4448 ML {* @{theory} *}
  4449 ML {* @{theory Pure} *}
  4450 ML {* @{theory_ref} *}
  4451 ML {* @{theory_ref Pure} *}
  4452 ML {* @{simpset} *}
  4453 ML {* @{claset} *}
  4454 ML {* @{clasimpset} *}
  4455 
  4456 The same works for sources being ``used'' within an Isar context.
  4457 
  4458 * ML in Isar: improved error reporting; extra verbosity with
  4459 ML_Context.trace enabled.
  4460 
  4461 * Pure/General/table.ML: the join operations now works via exceptions
  4462 DUP/SAME instead of type option. This is simpler in simple cases, and
  4463 admits slightly more efficient complex applications.
  4464 
  4465 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4466 use Context.generic instead of just theory.
  4467 
  4468 * Pure: datatype Context.generic joins theory/Proof.context and
  4469 provides some facilities for code that works in either kind of
  4470 context, notably GenericDataFun for uniform theory and proof data.
  4471 
  4472 * Pure: simplified internal attribute type, which is now always
  4473 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4474 local (Proof.context) attributes have been discontinued, while
  4475 minimizing code duplication. Thm.rule_attribute and
  4476 Thm.declaration_attribute build canonical attributes; see also structure
  4477 Context for further operations on Context.generic, notably
  4478 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4479 declarations and definitions.
  4480 
  4481 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4482 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4483 init only required for impure data. INCOMPATIBILITY: empty really need
  4484 to be empty (no dependencies on theory content!)
  4485 
  4486 * Pure/kernel: consts certification ignores sort constraints given in
  4487 signature declarations. (This information is not relevant to the
  4488 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4489 potential INCOMPATIBILITY.
  4490 
  4491 * Pure: axiomatic type classes are now purely definitional, with
  4492 explicit proofs of class axioms and super class relations performed
  4493 internally. See Pure/axclass.ML for the main internal interfaces --
  4494 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4495 AxClass.axiomatize_class/classrel/arity supersede
  4496 Sign.add_classes/classrel/arities.
  4497 
  4498 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4499 global/local versions on theory vs. Proof.context have been
  4500 discontinued; Attrib.syntax and Method.syntax have been adapted
  4501 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4502 attributes, methods, etc.
  4503 
  4504 * Pure: several functions of signature "... -> theory -> theory * ..."
  4505 have been reoriented to "... -> theory -> ... * theory" in order to
  4506 allow natural usage in combination with the ||>, ||>>, |-> and
  4507 fold_map combinators.
  4508 
  4509 * Pure: official theorem names (closed derivations) and additional
  4510 comments (tags) are now strictly separate.  Name hints -- which are
  4511 maintained as tags -- may be attached any time without affecting the
  4512 derivation.
  4513 
  4514 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4515 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4516 achieve the old behaviour.
  4517 
  4518 * Pure: the "Goal" constant is now called "prop", supporting a
  4519 slightly more general idea of ``protecting'' meta-level rule
  4520 statements.
  4521 
  4522 * Pure: Logic.(un)varify only works in a global context, which is now
  4523 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4524 Logic.legacy_(un)varify as temporary workaround.
  4525 
  4526 * Pure: structure Name provides scalable operations for generating
  4527 internal variable names, notably Name.variants etc.  This replaces
  4528 some popular functions from term.ML:
  4529 
  4530   Term.variant		->  Name.variant
  4531   Term.variantlist	->  Name.variant_list
  4532   Term.invent_names	->  Name.invent_list
  4533 
  4534 Note that low-level renaming rarely occurs in new code -- operations
  4535 from structure Variable are used instead (see below).
  4536 
  4537 * Pure: structure Variable provides fundamental operations for proper
  4538 treatment of fixed/schematic variables in a context.  For example,
  4539 Variable.import introduces fixes for schematics of given facts and
  4540 Variable.export reverses the effect (up to renaming) -- this replaces
  4541 various freeze_thaw operations.
  4542 
  4543 * Pure: structure Goal provides simple interfaces for
  4544 init/conclude/finish and tactical prove operations (replacing former
  4545 Tactic.prove).  Goal.prove is the canonical way to prove results
  4546 within a given context; Goal.prove_global is a degraded version for
  4547 theory level goals, including a global Drule.standard.  Note that
  4548 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4549 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4550 in a locale context).
  4551 
  4552 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4553 and type checking (Syntax.check_term etc.), with common combinations
  4554 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4555 which are considered legacy and await removal.
  4556 
  4557 * Pure/Syntax: generic interfaces for type unchecking
  4558 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4559 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4560 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4561 available for convenience, but refer to the very same operations using
  4562 a mere theory instead of a full context.
  4563 
  4564 * Isar: simplified treatment of user-level errors, using exception
  4565 ERROR of string uniformly.  Function error now merely raises ERROR,
  4566 without any side effect on output channels.  The Isar toplevel takes
  4567 care of proper display of ERROR exceptions.  ML code may use plain
  4568 handle/can/try; cat_error may be used to concatenate errors like this:
  4569 
  4570   ... handle ERROR msg => cat_error msg "..."
  4571 
  4572 Toplevel ML code (run directly or through the Isar toplevel) may be
  4573 embedded into the Isar toplevel with exception display/debug like
  4574 this:
  4575 
  4576   Isar.toplevel (fn () => ...)
  4577 
  4578 INCOMPATIBILITY, removed special transform_error facilities, removed
  4579 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4580 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4581 -- use plain ERROR instead.
  4582 
  4583 * Isar: theory setup now has type (theory -> theory), instead of a
  4584 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4585 
  4586 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4587 ProofContext.debug/verbose flags.
  4588 
  4589 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4590 theory before entering a proof state.  Transactions now always see a
  4591 quasi-functional intermediate checkpoint, both in interactive and
  4592 batch mode.
  4593 
  4594 * Isar: simplified interfaces for outer syntax.  Renamed
  4595 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4596 OuterSyntax.add_parsers -- this functionality is now included in
  4597 OuterSyntax.command etc.  INCOMPATIBILITY.
  4598 
  4599 * Simplifier: the simpset of a running simplification process now
  4600 contains a proof context (cf. Simplifier.the_context), which is the
  4601 very context that the initial simpset has been retrieved from (by
  4602 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4603 (solver, looper etc.) may depend on arbitrary proof data.
  4604 
  4605 * Simplifier.inherit_context inherits the proof context (plus the
  4606 local bounds) of the current simplification process; any simproc
  4607 etc. that calls the Simplifier recursively should do this!  Removed
  4608 former Simplifier.inherit_bounds, which is already included here --
  4609 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4610 specify an explicit context using Simplifier.context/theory_context.
  4611 
  4612 * Simplifier/Classical Reasoner: more abstract interfaces
  4613 change_simpset/claset for modifying the simpset/claset reference of a
  4614 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4615 INCOMPATIBILITY.
  4616 
  4617 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4618 "Trueprop" etc.
  4619 
  4620 
  4621 *** System ***
  4622 
  4623 * settings: the default heap location within ISABELLE_HOME_USER now
  4624 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4625 Isabelle installations.
  4626 
  4627 * isabelle-process: option -S (secure mode) disables some critical
  4628 operations, notably runtime compilation and evaluation of ML source
  4629 code.
  4630 
  4631 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4632 
  4633 * Support for parallel execution, using native multicore support of
  4634 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4635 independent theories, according to the given theory header
  4636 specifications. The maximum number of worker threads is specified via
  4637 usedir option -M or the "max-threads" setting in Proof General. A
  4638 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4639 to 6 on a 8-core machine.  User-code needs to observe certain
  4640 guidelines for thread-safe programming, see appendix A in the Isar
  4641 Implementation manual.
  4642 
  4643 
  4644 
  4645 New in Isabelle2005 (October 2005)
  4646 ----------------------------------
  4647 
  4648 *** General ***
  4649 
  4650 * Theory headers: the new header syntax for Isar theories is
  4651 
  4652   theory <name>
  4653   imports <theory1> ... <theoryN>
  4654   uses <file1> ... <fileM>
  4655   begin
  4656 
  4657 where the 'uses' part is optional.  The previous syntax
  4658 
  4659   theory <name> = <theory1> + ... + <theoryN>:
  4660 
  4661 will disappear in the next release.  Use isatool fixheaders to convert
  4662 existing theory files.  Note that there is no change in ancient
  4663 non-Isar theories now, but these will disappear soon.
  4664 
  4665 * Theory loader: parent theories can now also be referred to via
  4666 relative and absolute paths.
  4667 
  4668 * Command 'find_theorems' searches for a list of criteria instead of a
  4669 list of constants. Known criteria are: intro, elim, dest, name:string,
  4670 simp:term, and any term. Criteria can be preceded by '-' to select
  4671 theorems that do not match. Intro, elim, dest select theorems that
  4672 match the current goal, name:s selects theorems whose fully qualified
  4673 name contain s, and simp:term selects all simplification rules whose
  4674 lhs match term.  Any other term is interpreted as pattern and selects
  4675 all theorems matching the pattern. Available in ProofGeneral under
  4676 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4677 
  4678   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4679 
  4680 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4681 matching the current goal as introduction rule and not having "HOL."
  4682 in their name (i.e. not being defined in theory HOL).
  4683 
  4684 * Command 'thms_containing' has been discontinued in favour of
  4685 'find_theorems'; INCOMPATIBILITY.
  4686 
  4687 * Communication with Proof General is now 8bit clean, which means that
  4688 Unicode text in UTF-8 encoding may be used within theory texts (both
  4689 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4690 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4691 
  4692   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4693   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4694 
  4695 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4696 Classical Reasoner.  Typical big applications run around 2 times
  4697 faster.
  4698 
  4699 
  4700 *** Document preparation ***
  4701 
  4702 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4703 of raw sources.  Only those symbols that do not require additional
  4704 LaTeX packages (depending on comments in isabellesym.sty) are
  4705 displayed properly, everything else is left verbatim.  isatool display
  4706 and isatool print are used as front ends (these are subject to the
  4707 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4708 
  4709 * Command tags control specific markup of certain regions of text,
  4710 notably folding and hiding.  Predefined tags include "theory" (for
  4711 theory begin and end), "proof" for proof commands, and "ML" for
  4712 commands involving ML code; the additional tags "visible" and
  4713 "invisible" are unused by default.  Users may give explicit tag
  4714 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4715 interpretation of tags is determined by the LaTeX job during document
  4716 preparation: see option -V of isatool usedir, or options -n and -t of
  4717 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4718 \isadroptag.
  4719 
  4720 Several document versions may be produced at the same time via isatool
  4721 usedir (the generated index.html will link all of them).  Typical
  4722 specifications include ''-V document=theory,proof,ML'' to present
  4723 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4724 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4725 these parts without any formal replacement text.  The Isabelle site
  4726 default settings produce ''document'' and ''outline'' versions as
  4727 specified above.
  4728 
  4729 * Several new antiquotations:
  4730 
  4731   @{term_type term} prints a term with its type annotated;
  4732 
  4733   @{typeof term} prints the type of a term;
  4734 
  4735   @{const const} is the same as @{term const}, but checks that the
  4736   argument is a known logical constant;
  4737 
  4738   @{term_style style term} and @{thm_style style thm} print a term or
  4739   theorem applying a "style" to it
  4740 
  4741   @{ML text}
  4742 
  4743 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4744 definitions, equations, inequations etc., 'concl' printing only the
  4745 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4746 to print the specified premise.  TermStyle.add_style provides an ML
  4747 interface for introducing further styles.  See also the "LaTeX Sugar"
  4748 document practical applications.  The ML antiquotation prints
  4749 type-checked ML expressions verbatim.
  4750 
  4751 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4752 and 'text' support optional locale specification '(in loc)', which
  4753 specifies the default context for interpreting antiquotations.  For
  4754 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4755 
  4756 * Option 'locale=NAME' of antiquotations specifies an alternative
  4757 context interpreting the subsequent argument.  For example: @{thm
  4758 [locale=lattice] inf_assoc}.
  4759 
  4760 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4761 a proof context.
  4762 
  4763 * Proper output of antiquotations for theory commands involving a
  4764 proof context (such as 'locale' or 'theorem (in loc) ...').
  4765 
  4766 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4767 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4768 
  4769 * isatool usedir: new option -C (default true) controls whether option
  4770 -D should include a copy of the original document directory; -C false
  4771 prevents unwanted effects such as copying of administrative CVS data.
  4772 
  4773 
  4774 *** Pure ***
  4775 
  4776 * Considerably improved version of 'constdefs' command.  Now performs
  4777 automatic type-inference of declared constants; additional support for
  4778 local structure declarations (cf. locales and HOL records), see also
  4779 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4780 sequential dependencies of definitions within a single 'constdefs'
  4781 section; moreover, the declared name needs to be an identifier.  If
  4782 all fails, consider to fall back on 'consts' and 'defs' separately.
  4783 
  4784 * Improved indexed syntax and implicit structures.  First of all,
  4785 indexed syntax provides a notational device for subscripted
  4786 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4787 expressions.  Secondly, in a local context with structure
  4788 declarations, number indexes \<^sub>n or the empty index (default
  4789 number 1) refer to a certain fixed variable implicitly; option
  4790 show_structs controls printing of implicit structures.  Typical
  4791 applications of these concepts involve record types and locales.
  4792 
  4793 * New command 'no_syntax' removes grammar declarations (and
  4794 translations) resulting from the given syntax specification, which is
  4795 interpreted in the same manner as for the 'syntax' command.
  4796 
  4797 * 'Advanced' translation functions (parse_translation etc.) may depend
  4798 on the signature of the theory context being presently used for
  4799 parsing/printing, see also isar-ref manual.
  4800 
  4801 * Improved 'oracle' command provides a type-safe interface to turn an
  4802 ML expression of type theory -> T -> term into a primitive rule of
  4803 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4804 is already included here); see also FOL/ex/IffExample.thy;
  4805 INCOMPATIBILITY.
  4806 
  4807 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4808 before); "cI" is no longer bound, use "c.intro" instead.
  4809 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4810 axclasses vs. locales.
  4811 
  4812 * Improved internal renaming of symbolic identifiers -- attach primes
  4813 instead of base 26 numbers.
  4814 
  4815 * New flag show_question_marks controls printing of leading question
  4816 marks in schematic variable names.
  4817 
  4818 * In schematic variable names, *any* symbol following \<^isub> or
  4819 \<^isup> is now treated as part of the base name.  For example, the
  4820 following works without printing of awkward ".0" indexes:
  4821 
  4822   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4823     by simp
  4824 
  4825 * Inner syntax includes (*(*nested*) comments*).
  4826 
  4827 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4828 annotations as "(00...)".
  4829 
  4830 * Clear separation of logical types and nonterminals, where the latter
  4831 may only occur in 'syntax' specifications or type abbreviations.
  4832 Before that distinction was only partially implemented via type class
  4833 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4834 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4835 exotic syntax specifications may require further adaption
  4836 (e.g. Cube/Cube.thy).
  4837 
  4838 * Removed obsolete type class "logic", use the top sort {} instead.
  4839 Note that non-logical types should be declared as 'nonterminals'
  4840 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4841 specifications.
  4842 
  4843 * Attributes 'induct' and 'cases': type or set names may now be
  4844 locally fixed variables as well.
  4845 
  4846 * Simplifier: can now control the depth to which conditional rewriting
  4847 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4848 Limit.
  4849 
  4850 * Simplifier: simplification procedures may now take the current
  4851 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4852 interface), which is very useful for calling the Simplifier
  4853 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4854 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4855 low-level mk_simproc no longer applies Logic.varify internally, to
  4856 allow for use in a context of fixed variables.
  4857 
  4858 * thin_tac now works even if the assumption being deleted contains !!
  4859 or ==>.  More generally, erule now works even if the major premise of
  4860 the elimination rule contains !! or ==>.
  4861 
  4862 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4863 
  4864 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4865 from Pure, which contains all common declarations already.  Both
  4866 theories are defined via plain Isabelle/Isar .thy files.
  4867 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4868 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4869 use isatool fixcpure to adapt your theory and ML sources.
  4870 
  4871 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4872 selections of theorems in named facts via index ranges.
  4873 
  4874 * 'print_theorems': in theory mode, really print the difference
  4875 wrt. the last state (works for interactive theory development only),
  4876 in proof mode print all local facts (cf. 'print_facts');
  4877 
  4878 * 'hide': option '(open)' hides only base names.
  4879 
  4880 * More efficient treatment of intermediate checkpoints in interactive
  4881 theory development.
  4882 
  4883 * Code generator is now invoked via code_module (incremental code
  4884 generation) and code_library (modular code generation, ML structures
  4885 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4886 must be quoted when used as identifiers.
  4887 
  4888 * New 'value' command for reading, evaluating and printing terms using
  4889 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4890 quoted when used as identifier.
  4891 
  4892 
  4893 *** Locales ***
  4894 
  4895 * New commands for the interpretation of locale expressions in
  4896 theories (1), locales (2) and proof contexts (3).  These generate
  4897 proof obligations from the expression specification.  After the
  4898 obligations have been discharged, theorems of the expression are added
  4899 to the theory, target locale or proof context.  The synopsis of the
  4900 commands is a follows:
  4901 
  4902   (1) interpretation expr inst
  4903   (2) interpretation target < expr
  4904   (3) interpret expr inst
  4905 
  4906 Interpretation in theories and proof contexts require a parameter
  4907 instantiation of terms from the current context.  This is applied to
  4908 specifications and theorems of the interpreted expression.
  4909 Interpretation in locales only permits parameter renaming through the
  4910 locale expression.  Interpretation is smart in that interpretations
  4911 that are active already do not occur in proof obligations, neither are
  4912 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4913 inspect active interpretations of a particular locale.  For details,
  4914 see the Isar Reference manual.  Examples can be found in
  4915 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4916 
  4917 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4918 'interpret' instead.
  4919 
  4920 * New context element 'constrains' for adding type constraints to
  4921 parameters.
  4922 
  4923 * Context expressions: renaming of parameters with syntax
  4924 redeclaration.
  4925 
  4926 * Locale declaration: 'includes' disallowed.
  4927 
  4928 * Proper static binding of attribute syntax -- i.e. types / terms /
  4929 facts mentioned as arguments are always those of the locale definition
  4930 context, independently of the context of later invocations.  Moreover,
  4931 locale operations (renaming and type / term instantiation) are applied
  4932 to attribute arguments as expected.
  4933 
  4934 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4935 actual attributes; rare situations may require Attrib.attribute to
  4936 embed those attributes into Attrib.src that lack concrete syntax.
  4937 Attribute implementations need to cooperate properly with the static
  4938 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4939 Attrib.XXX_thm etc. already do the right thing without further
  4940 intervention.  Only unusual applications -- such as "where" or "of"
  4941 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4942 on the context and the facts involved -- may have to assign parsed
  4943 values to argument tokens explicitly.
  4944 
  4945 * Changed parameter management in theorem generation for long goal
  4946 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4947 theorem statement in rare situations.
  4948 
  4949 * Locale inspection command 'print_locale' omits notes elements.  Use
  4950 'print_locale!' to have them included in the output.
  4951 
  4952 
  4953 *** Provers ***
  4954 
  4955 * Provers/hypsubst.ML: improved version of the subst method, for
  4956 single-step rewriting: it now works in bound variable contexts. New is
  4957 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4958 rewrite a different subterm than the original subst method, which is
  4959 still available as 'simplesubst'.
  4960 
  4961 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4962 and quasi orders.
  4963 
  4964 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4965 reflexive-transitive closure of relations.
  4966 
  4967 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4968 limit (previously hard-coded with a value of 20) user-definable.
  4969 
  4970 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4971 is peformed already.  Object-logics merely need to finish their
  4972 initial simpset configuration as before.  INCOMPATIBILITY.
  4973 
  4974 
  4975 *** HOL ***
  4976 
  4977 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4978 
  4979   syntax (epsilon)
  4980     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4981 
  4982 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4983 and x-symbol; use option '-m epsilon' to get it actually printed.
  4984 Moreover, the mathematically important symbolic identifier \<epsilon>
  4985 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4986 
  4987 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4988 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4989 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4990 support corresponding Isar calculations.
  4991 
  4992 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4993 instead of ":".
  4994 
  4995 * theory SetInterval: changed the syntax for open intervals:
  4996 
  4997   Old       New
  4998   {..n(}    {..<n}
  4999   {)n..}    {n<..}
  5000   {m..n(}   {m..<n}
  5001   {)m..n}   {m<..n}
  5002   {)m..n(}  {m<..<n}
  5003 
  5004 The old syntax is still supported but will disappear in the next
  5005 release.  For conversion use the following Emacs search and replace
  5006 patterns (these are not perfect but work quite well):
  5007 
  5008   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5009   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5010 
  5011 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5012 equalities in commutative rings; method 'algebra' provides a generic
  5013 interface.
  5014 
  5015 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5016 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5017 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5018 be a tuple pattern.
  5019 
  5020 Some new syntax forms are available:
  5021 
  5022   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5023   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5024   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5025   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5026 
  5027 The latter form "\<Sum>x < k. e" used to be based on a separate
  5028 function "Summation", which has been discontinued.
  5029 
  5030 * theory Finite_Set: in structured induction proofs, the insert case
  5031 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5032 (insert F x)'.
  5033 
  5034 * The 'refute' command has been extended to support a much larger
  5035 fragment of HOL, including axiomatic type classes, constdefs and
  5036 typedefs, inductive datatypes and recursion.
  5037 
  5038 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5039 Requires zChaff with proof generation to be installed.  See
  5040 HOL/ex/SAT_Examples.thy for examples.
  5041 
  5042 * Datatype induction via method 'induct' now preserves the name of the
  5043 induction variable. For example, when proving P(xs::'a list) by
  5044 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5045 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5046 in unstructured proof scripts.
  5047 
  5048 * Reworked implementation of records.  Improved scalability for
  5049 records with many fields, avoiding performance problems for type
  5050 inference. Records are no longer composed of nested field types, but
  5051 of nested extension types. Therefore the record type only grows linear
  5052 in the number of extensions and not in the number of fields.  The
  5053 top-level (users) view on records is preserved.  Potential
  5054 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5055 old record representation. The type generated for a record is called
  5056 <record_name>_ext_type.
  5057 
  5058 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5059 proofs triggered by a record definition or a simproc (if
  5060 quick_and_dirty is enabled).  Definitions of large records can take
  5061 quite long.
  5062 
  5063 New simproc record_upd_simproc for simplification of multiple record
  5064 updates enabled by default.  Moreover, trivial updates are also
  5065 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5066 occasionally, since simplification is more powerful by default.
  5067 
  5068 * typedef: proper support for polymorphic sets, which contain extra
  5069 type-variables in the term.
  5070 
  5071 * Simplifier: automatically reasons about transitivity chains
  5072 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5073 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5074 old proofs break occasionally as simplification may now solve more
  5075 goals than previously.
  5076 
  5077 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5078 present.  Works for all partial orders (class "order"), in particular
  5079 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5080 just like y <= x.
  5081 
  5082 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5083 bound variable or a constant then the let is unfolded.  Otherwise
  5084 first a is simplified to b, and then f b is simplified to g. If
  5085 possible we abstract b from g arriving at "let x = b in h x",
  5086 otherwise we unfold the let and arrive at g.  The simproc can be
  5087 enabled/disabled by the reference use_let_simproc.  Potential
  5088 INCOMPATIBILITY since simplification is more powerful by default.
  5089 
  5090 * Classical reasoning: the meson method now accepts theorems as arguments.
  5091 
  5092 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5093 jobs to provide advice on the provability of subgoals.
  5094 
  5095 * Theory OrderedGroup and Ring_and_Field: various additions and
  5096 improvements to faciliate calculations involving equalities and
  5097 inequalities.
  5098 
  5099 The following theorems have been eliminated or modified
  5100 (INCOMPATIBILITY):
  5101 
  5102   abs_eq             now named abs_of_nonneg
  5103   abs_of_ge_0        now named abs_of_nonneg
  5104   abs_minus_eq       now named abs_of_nonpos
  5105   imp_abs_id         now named abs_of_nonneg
  5106   imp_abs_neg_id     now named abs_of_nonpos
  5107   mult_pos           now named mult_pos_pos
  5108   mult_pos_le        now named mult_nonneg_nonneg
  5109   mult_pos_neg_le    now named mult_nonneg_nonpos
  5110   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5111   mult_neg           now named mult_neg_neg
  5112   mult_neg_le        now named mult_nonpos_nonpos
  5113 
  5114 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5115      
  5116      zero_le_square
  5117      not_square_less_zero 
  5118 
  5119   The following lemmas have been deleted from Real/RealPow:
  5120   
  5121      realpow_zero_zero
  5122      realpow_two
  5123      realpow_less
  5124      zero_le_power
  5125      realpow_two_le
  5126      abs_realpow_two
  5127      realpow_two_abs     
  5128 
  5129 * Theory Parity: added rules for simplifying exponents.
  5130 
  5131 * Theory List:
  5132 
  5133 The following theorems have been eliminated or modified
  5134 (INCOMPATIBILITY):
  5135 
  5136   list_all_Nil       now named list_all.simps(1)
  5137   list_all_Cons      now named list_all.simps(2)
  5138   list_all_conv      now named list_all_iff
  5139   set_mem_eq         now named mem_iff
  5140 
  5141 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5142 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5143 
  5144 
  5145 *** HOL-Complex ***
  5146 
  5147 * Theory RealDef: better support for embedding natural numbers and
  5148 integers in the reals.
  5149 
  5150 The following theorems have been eliminated or modified
  5151 (INCOMPATIBILITY):
  5152 
  5153   exp_ge_add_one_self  now requires no hypotheses
  5154   real_of_int_add      reversed direction of equality (use [symmetric])
  5155   real_of_int_minus    reversed direction of equality (use [symmetric])
  5156   real_of_int_diff     reversed direction of equality (use [symmetric])
  5157   real_of_int_mult     reversed direction of equality (use [symmetric])
  5158 
  5159 * Theory RComplete: expanded support for floor and ceiling functions.
  5160 
  5161 * Theory Ln is new, with properties of the natural logarithm
  5162 
  5163 * Hyperreal: There is a new type constructor "star" for making
  5164 nonstandard types.  The old type names are now type synonyms:
  5165 
  5166   hypreal = real star
  5167   hypnat = nat star
  5168   hcomplex = complex star
  5169 
  5170 * Hyperreal: Many groups of similarly-defined constants have been
  5171 replaced by polymorphic versions (INCOMPATIBILITY):
  5172 
  5173   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5174 
  5175   starset      <-- starsetNat, starsetC
  5176   *s*          <-- *sNat*, *sc*
  5177   starset_n    <-- starsetNat_n, starsetC_n
  5178   *sn*         <-- *sNatn*, *scn*
  5179   InternalSets <-- InternalNatSets, InternalCSets
  5180 
  5181   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5182   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5183   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5184   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5185   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5186 
  5187 * Hyperreal: Many type-specific theorems have been removed in favor of
  5188 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5189 
  5190   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5191   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5192   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5193   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5194   right_minus <-- hypreal_add_minus
  5195   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5196   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5197   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5198   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5199   mult_1_right <-- hcomplex_mult_one_right
  5200   mult_zero_left <-- hcomplex_mult_zero_left
  5201   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5202   right_distrib <-- hypnat_add_mult_distrib2
  5203   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5204   right_inverse <-- hypreal_mult_inverse
  5205   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5206   order_refl <-- {hypreal,hypnat}_le_refl
  5207   order_trans <-- {hypreal,hypnat}_le_trans
  5208   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5209   order_less_le <-- {hypreal,hypnat}_less_le
  5210   linorder_linear <-- {hypreal,hypnat}_le_linear
  5211   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5212   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5213   add_nonneg_nonneg <-- hypreal_le_add_order
  5214 
  5215 * Hyperreal: Separate theorems having to do with type-specific
  5216 versions of constants have been merged into theorems that apply to the
  5217 new polymorphic constants (INCOMPATIBILITY):
  5218 
  5219   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5220   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5221   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5222   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5223   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5224   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5225   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5226   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5227   STAR_diff <-- {STAR,STARC}_diff
  5228   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5229     STARC_hcomplex_of_complex}_image_subset
  5230   starset_n_Un <-- starset{Nat,C}_n_Un
  5231   starset_n_Int <-- starset{Nat,C}_n_Int
  5232   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5233   starset_n_diff <-- starset{Nat,C}_n_diff
  5234   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5235   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5236   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5237   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5238   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5239   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5240   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5241   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5242   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5243   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5244   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5245   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5246   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5247   starfun_diff <-- starfun{C,RC,CR}_diff
  5248   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5249   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5250   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5251   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5252   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5253   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5254   starfun_Id <-- starfunC_Id
  5255   starfun_approx <-- starfun{Nat,CR}_approx
  5256   starfun_capprox <-- starfun{C,RC}_capprox
  5257   starfun_abs <-- starfunNat_rabs
  5258   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5259   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5260   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5261   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5262   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5263   starfun_add_approx <-- starfunCR_add_approx
  5264   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5265   starfun_divide <-- starfun{C,CR,RC}_divide
  5266   starfun_n <-- starfun{Nat,C}_n
  5267   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5268   starfun_n_add <-- starfun{Nat,C}_n_add
  5269   starfun_n_add_minus <-- starfunNat_n_add_minus
  5270   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5271   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5272   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5273 
  5274   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5275   star_n_minus <-- {hypreal,hcomplex}_minus
  5276   star_n_diff <-- {hypreal,hcomplex}_diff
  5277   star_n_mult <-- {hypreal,hcomplex}_mult
  5278   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5279   star_n_le <-- {hypreal,hypnat}_le
  5280   star_n_less <-- {hypreal,hypnat}_less
  5281   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5282   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5283   star_n_abs <-- hypreal_hrabs
  5284   star_n_divide <-- hcomplex_divide
  5285 
  5286   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5287   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5288   star_of_diff <-- hypreal_of_real_diff
  5289   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5290   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5291   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5292   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5293   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5294   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5295   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5296   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5297   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5298   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5299   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5300   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5301   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5302   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5303   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5304   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5305   star_of_power <-- hypreal_of_real_power
  5306   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5307 
  5308 * Hyperreal: new method "transfer" that implements the transfer
  5309 principle of nonstandard analysis. With a subgoal that mentions
  5310 nonstandard types like "'a star", the command "apply transfer"
  5311 replaces it with an equivalent one that mentions only standard types.
  5312 To be successful, all free variables must have standard types; non-
  5313 standard variables must have explicit universal quantifiers.
  5314 
  5315 * Hyperreal: A theory of Taylor series.
  5316 
  5317 
  5318 *** HOLCF ***
  5319 
  5320 * Discontinued special version of 'constdefs' (which used to support
  5321 continuous functions) in favor of the general Pure one with full
  5322 type-inference.
  5323 
  5324 * New simplification procedure for solving continuity conditions; it
  5325 is much faster on terms with many nested lambda abstractions (cubic
  5326 instead of exponential time).
  5327 
  5328 * New syntax for domain package: selector names are now optional.
  5329 Parentheses should be omitted unless argument is lazy, for example:
  5330 
  5331   domain 'a stream = cons "'a" (lazy "'a stream")
  5332 
  5333 * New command 'fixrec' for defining recursive functions with pattern
  5334 matching; defining multiple functions with mutual recursion is also
  5335 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5336 sinr, or any data constructor defined by the domain package. The given
  5337 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5338 syntax and examples.
  5339 
  5340 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5341 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5342 but the proof obligation additionally includes an admissibility
  5343 requirement. The packages generate instances of class cpo or pcpo,
  5344 with continuity and strictness theorems for Rep and Abs.
  5345 
  5346 * HOLCF: Many theorems have been renamed according to a more standard naming
  5347 scheme (INCOMPATIBILITY):
  5348 
  5349   foo_inject:  "foo$x = foo$y ==> x = y"
  5350   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5351   foo_less:    "(foo$x << foo$y) = (x << y)"
  5352   foo_strict:  "foo$UU = UU"
  5353   foo_defined: "... ==> foo$x ~= UU"
  5354   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5355 
  5356 
  5357 *** ZF ***
  5358 
  5359 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5360 including the First Isomorphism Theorem (on quotienting by the kernel
  5361 of a homomorphism).
  5362 
  5363 * ZF/Simplifier: install second copy of type solver that actually
  5364 makes use of TC rules declared to Isar proof contexts (or locales);
  5365 the old version is still required for ML proof scripts.
  5366 
  5367 
  5368 *** Cube ***
  5369 
  5370 * Converted to Isar theory format; use locales instead of axiomatic
  5371 theories.
  5372 
  5373 
  5374 *** ML ***
  5375 
  5376 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5377 for ||>, ||>>, |>>,
  5378 
  5379 * Pure/library.ML no longer defines its own option datatype, but uses
  5380 that of the SML basis, which has constructors NONE and SOME instead of
  5381 None and Some, as well as exception Option.Option instead of OPTION.
  5382 The functions the, if_none, is_some, is_none have been adapted
  5383 accordingly, while Option.map replaces apsome.
  5384 
  5385 * Pure/library.ML: the exception LIST has been given up in favour of
  5386 the standard exceptions Empty and Subscript, as well as
  5387 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5388 superceded by the standard hd and tl functions etc.
  5389 
  5390 A number of basic list functions are no longer exported to the ML
  5391 toplevel, as they are variants of predefined functions.  The following
  5392 suggests how one can translate existing code:
  5393 
  5394     rev_append xs ys = List.revAppend (xs, ys)
  5395     nth_elem (i, xs) = List.nth (xs, i)
  5396     last_elem xs = List.last xs
  5397     flat xss = List.concat xss
  5398     seq fs = List.app fs
  5399     partition P xs = List.partition P xs
  5400     mapfilter f xs = List.mapPartial f xs
  5401 
  5402 * Pure/library.ML: several combinators for linear functional
  5403 transformations, notably reverse application and composition:
  5404 
  5405   x |> f                f #> g
  5406   (x, y) |-> f          f #-> g
  5407 
  5408 * Pure/library.ML: introduced/changed precedence of infix operators:
  5409 
  5410   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5411   infix 2 ?;
  5412   infix 3 o oo ooo oooo;
  5413   infix 4 ~~ upto downto;
  5414 
  5415 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5416 infix operators.
  5417 
  5418 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5419 fold_map support linear functional transformations and nesting.  For
  5420 example:
  5421 
  5422   fold f [x1, ..., xN] y =
  5423     y |> f x1 |> ... |> f xN
  5424 
  5425   (fold o fold) f [xs1, ..., xsN] y =
  5426     y |> fold f xs1 |> ... |> fold f xsN
  5427 
  5428   fold f [x1, ..., xN] =
  5429     f x1 #> ... #> f xN
  5430 
  5431   (fold o fold) f [xs1, ..., xsN] =
  5432     fold f xs1 #> ... #> fold f xsN
  5433 
  5434 * Pure/library.ML: the following selectors on type 'a option are
  5435 available:
  5436 
  5437   the:               'a option -> 'a  (*partial*)
  5438   these:             'a option -> 'a  where 'a = 'b list
  5439   the_default: 'a -> 'a option -> 'a
  5440   the_list:          'a option -> 'a list
  5441 
  5442 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5443 basic operations for association lists, following natural argument
  5444 order; moreover the explicit equality predicate passed here avoids
  5445 potentially expensive polymorphic runtime equality checks.
  5446 The old functions may be expressed as follows:
  5447 
  5448   assoc = uncurry (AList.lookup (op =))
  5449   assocs = these oo AList.lookup (op =)
  5450   overwrite = uncurry (AList.update (op =)) o swap
  5451 
  5452 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5453 
  5454   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5455   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5456 
  5457 replacing make_keylist and keyfilter (occassionally used)
  5458 Naive rewrites:
  5459 
  5460   make_keylist = AList.make
  5461   keyfilter = AList.find (op =)
  5462 
  5463 * eq_fst and eq_snd now take explicit equality parameter, thus
  5464   avoiding eqtypes. Naive rewrites:
  5465 
  5466     eq_fst = eq_fst (op =)
  5467     eq_snd = eq_snd (op =)
  5468 
  5469 * Removed deprecated apl and apr (rarely used).
  5470   Naive rewrites:
  5471 
  5472     apl (n, op) =>>= curry op n
  5473     apr (op, m) =>>= fn n => op (n, m)
  5474 
  5475 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5476 provides a reasonably efficient light-weight implementation of sets as
  5477 lists.
  5478 
  5479 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5480 few new operations; existing lookup and update are now curried to
  5481 follow natural argument order (for use with fold etc.);
  5482 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5483 
  5484 * Pure/General: output via the Isabelle channels of
  5485 writeln/warning/error etc. is now passed through Output.output, with a
  5486 hook for arbitrary transformations depending on the print_mode
  5487 (cf. Output.add_mode -- the first active mode that provides a output
  5488 function wins).  Already formatted output may be embedded into further
  5489 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5490 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5491 accommodate easy composition of diagnostic messages etc.  Programmers
  5492 rarely need to care about Output.output or Output.raw at all, with
  5493 some notable exceptions: Output.output is required when bypassing the
  5494 standard channels (writeln etc.), or in token translations to produce
  5495 properly formatted results; Output.raw is required when capturing
  5496 already output material that will eventually be presented to the user
  5497 a second time.  For the default print mode, both Output.output and
  5498 Output.raw have no effect.
  5499 
  5500 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5501 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5502 cumulative results are displayed at the end of a batch session.
  5503 
  5504 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5505 replaced by File.platform_path and File.shell_path (with appropriate
  5506 hooks).  This provides a clean interface for unusual systems where the
  5507 internal and external process view of file names are different.
  5508 
  5509 * Pure: more efficient orders for basic syntactic entities: added
  5510 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5511 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5512 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5513 orders now -- potential INCOMPATIBILITY for code that depends on a
  5514 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5515 Library.sort_strings on result).
  5516 
  5517 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5518 fold_types traverse types/terms from left to right, observing natural
  5519 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5520 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5521 
  5522 * Pure: name spaces have been refined, with significant changes of the
  5523 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5524 to extern(_table).  The plain name entry path is superceded by a
  5525 general 'naming' context, which also includes the 'policy' to produce
  5526 a fully qualified name and external accesses of a fully qualified
  5527 name; NameSpace.extend is superceded by context dependent
  5528 Sign.declare_name.  Several theory and proof context operations modify
  5529 the naming context.  Especially note Theory.restore_naming and
  5530 ProofContext.restore_naming to get back to a sane state; note that
  5531 Theory.add_path is no longer sufficient to recover from
  5532 Theory.absolute_path in particular.
  5533 
  5534 * Pure: new flags short_names (default false) and unique_names
  5535 (default true) for controlling output of qualified names.  If
  5536 short_names is set, names are printed unqualified.  If unique_names is
  5537 reset, the name prefix is reduced to the minimum required to achieve
  5538 the original result when interning again, even if there is an overlap
  5539 with earlier declarations.
  5540 
  5541 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5542 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5543 (useful for printing error messages).  INCOMPATIBILITY.
  5544 
  5545 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5546 Theory.theory are now identified, referring to the universal
  5547 Context.theory (see Pure/context.ML).  Actual signature and theory
  5548 content is managed as theory data.  The old code and interfaces were
  5549 spread over many files and structures; the new arrangement introduces
  5550 considerable INCOMPATIBILITY to gain more clarity:
  5551 
  5552   Context -- theory management operations (name, identity, inclusion,
  5553     parents, ancestors, merge, etc.), plus generic theory data;
  5554 
  5555   Sign -- logical signature and syntax operations (declaring consts,
  5556     types, etc.), plus certify/read for common entities;
  5557 
  5558   Theory -- logical theory operations (stating axioms, definitions,
  5559     oracles), plus a copy of logical signature operations (consts,
  5560     types, etc.); also a few basic management operations (Theory.copy,
  5561     Theory.merge, etc.)
  5562 
  5563 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5564 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5565 for convenience -- they merely return the theory.
  5566 
  5567 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5568 
  5569 * Pure: the Isar proof context type is already defined early in Pure
  5570 as Context.proof (note that ProofContext.context and Proof.context are
  5571 aliases, where the latter is the preferred name).  This enables other
  5572 Isabelle components to refer to that type even before Isar is present.
  5573 
  5574 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5575 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5576 any of these kinds.  For example, Sign.intern typeK is now
  5577 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5578 Theory.hide_types.  Also note that former
  5579 Theory.hide_classes/types/consts are now
  5580 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5581 internalize their arguments!  INCOMPATIBILITY.
  5582 
  5583 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5584 datatype thmref (with constructors Name and NameSelection) instead of
  5585 plain string -- INCOMPATIBILITY;
  5586 
  5587 * Pure: cases produced by proof methods specify options, where NONE
  5588 means to remove case bindings -- INCOMPATIBILITY in
  5589 (RAW_)METHOD_CASES.
  5590 
  5591 * Pure: the following operations retrieve axioms or theorems from a
  5592 theory node or theory hierarchy, respectively:
  5593 
  5594   Theory.axioms_of: theory -> (string * term) list
  5595   Theory.all_axioms_of: theory -> (string * term) list
  5596   PureThy.thms_of: theory -> (string * thm) list
  5597   PureThy.all_thms_of: theory -> (string * thm) list
  5598 
  5599 * Pure: print_tac now outputs the goal through the trace channel.
  5600 
  5601 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5602 Reference Toplevel.debug (default false) controls detailed printing
  5603 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5604 controls execution profiling -- set to 1 for time and 2 for space
  5605 (both increase the runtime).
  5606 
  5607 * Isar session: The initial use of ROOT.ML is now always timed,
  5608 i.e. the log will show the actual process times, in contrast to the
  5609 elapsed wall-clock time that the outer shell wrapper produces.
  5610 
  5611 * Simplifier: improved handling of bound variables (nameless
  5612 representation, avoid allocating new strings).  Simprocs that invoke
  5613 the Simplifier recursively should use Simplifier.inherit_bounds to
  5614 avoid local name clashes.  Failure to do so produces warnings
  5615 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5616 for further details.
  5617 
  5618 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5619 bindings for all theorems stored within a given theory; this may help
  5620 in porting non-Isar theories to Isar ones, while keeping ML proof
  5621 scripts for the time being.
  5622 
  5623 * ML operator HTML.with_charset specifies the charset begin used for
  5624 generated HTML files.  For example:
  5625 
  5626   HTML.with_charset "utf-8" use_thy "Hebrew";
  5627   HTML.with_charset "utf-8" use_thy "Chinese";
  5628 
  5629 
  5630 *** System ***
  5631 
  5632 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5633 isabelle, isatool etc.).
  5634 
  5635 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5636 isatool doc, isatool mkdir, display_drafts etc.).
  5637 
  5638 * isatool usedir: option -f allows specification of the ML file to be
  5639 used by Isabelle; default is ROOT.ML.
  5640 
  5641 * New isatool version outputs the version identifier of the Isabelle
  5642 distribution being used.
  5643 
  5644 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5645 (containing Boolean satisfiability problems) into Isabelle/HOL
  5646 theories.
  5647 
  5648 
  5649 
  5650 New in Isabelle2004 (April 2004)
  5651 --------------------------------
  5652 
  5653 *** General ***
  5654 
  5655 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5656   Replaces linorder.ML.
  5657 
  5658 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5659   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5660   (\<a>...\<z>), are now considered normal letters, and can therefore
  5661   be used anywhere where an ASCII letter (a...zA...Z) has until
  5662   now. COMPATIBILITY: This obviously changes the parsing of some
  5663   terms, especially where a symbol has been used as a binder, say
  5664   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5665   as an identifier.  Fix it by inserting a space around former
  5666   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5667   existing theory and ML files.
  5668 
  5669 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5670 
  5671 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5672   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5673   a normal (but invisible) letter. For multiple letter subscripts repeat
  5674   \<^isub> like this: x\<^isub>1\<^isub>2.
  5675 
  5676 * Pure: There are now sub-/superscripts that can span more than one
  5677   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5678   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5679   superscript. The new control characters are not identifier parts.
  5680 
  5681 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5682   content of "..." to the latex file instead of \isacntrl... . The "..."
  5683   may consist of any printable characters excluding the end bracket >.
  5684 
  5685 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5686   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5687   declare constants "final", which prevents their being given a definition
  5688   later.  It is useful for constants whose behaviour is fixed axiomatically
  5689   rather than definitionally, such as the meta-logic connectives.
  5690 
  5691 * Pure: 'instance' now handles general arities with general sorts
  5692   (i.e. intersections of classes),
  5693 
  5694 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5695   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5696   It can be changed to alter the colors/layout of generated pages.
  5697 
  5698 
  5699 *** Isar ***
  5700 
  5701 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5702   cut_tac, subgoal_tac and thin_tac:
  5703   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5704     locales are no longer forced to write Isar proof scripts.
  5705     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5706     emulations.
  5707   - INCOMPATIBILITY: names of variables to be instantiated may no
  5708     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5709     This is consistent with the instantiation attribute "where".
  5710 
  5711 * Attributes "where" and "of":
  5712   - Now take type variables of instantiated theorem into account when reading
  5713     the instantiation string.  This fixes a bug that caused instantiated
  5714     theorems to have too special types in some circumstances.
  5715   - "where" permits explicit instantiations of type variables.
  5716 
  5717 * Calculation commands "moreover" and "also" no longer interfere with
  5718   current facts ("this"), admitting arbitrary combinations with "then"
  5719   and derived forms.
  5720 
  5721 * Locales:
  5722   - Goal statements involving the context element "includes" no longer
  5723     generate theorems with internal delta predicates (those ending on
  5724     "_axioms") in the premise.
  5725     Resolve particular premise with <locale>.intro to obtain old form.
  5726   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5727     specification and "includes" elements in goal statement.
  5728   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5729     [intro?] and [elim?] (respectively) by default.
  5730   - Experimental command for instantiation of locales in proof contexts:
  5731         instantiate <label>[<attrs>]: <loc>
  5732     Instantiates locale <loc> and adds all its theorems to the current context
  5733     taking into account their attributes.  Label and attrs are optional
  5734     modifiers, like in theorem declarations.  If present, names of
  5735     instantiated theorems are qualified with <label>, and the attributes
  5736     <attrs> are applied after any attributes these theorems might have already.
  5737       If the locale has assumptions, a chained fact of the form
  5738     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5739     are derived.  The command does not support old-style locales declared
  5740     with "locale (open)".
  5741       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5742 
  5743 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5744   (Isar) contexts.
  5745 
  5746 
  5747 *** HOL ***
  5748 
  5749 * Proof import: new image HOL4 contains the imported library from
  5750   the HOL4 system with about 2500 theorems. It is imported by
  5751   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5752   can be used like any other Isabelle image.  See
  5753   HOL/Import/HOL/README for more information.
  5754 
  5755 * Simplifier:
  5756   - Much improved handling of linear and partial orders.
  5757     Reasoners for linear and partial orders are set up for type classes
  5758     "linorder" and "order" respectively, and are added to the default simpset
  5759     as solvers.  This means that the simplifier can build transitivity chains
  5760     to solve goals from the assumptions.
  5761   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5762     of blast or auto after simplification become unnecessary because the goal
  5763     is solved by simplification already.
  5764 
  5765 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5766     all proved in axiomatic type classes for semirings, rings and fields.
  5767 
  5768 * Numerics:
  5769   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5770     now formalized using the Ring_and_Field theory mentioned above.
  5771   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5772     than before, because now they are set up once in a generic manner.
  5773   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5774     Look for the general versions in Ring_and_Field (and Power if they concern
  5775     exponentiation).
  5776 
  5777 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5778 
  5779 * Records:
  5780   - Record types are now by default printed with their type abbreviation
  5781     instead of the list of all field types. This can be configured via
  5782     the reference "print_record_type_abbr".
  5783   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5784     (not enabled by default).
  5785   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5786     EX x. x = sel r to True (not enabled by default).
  5787   - Tactic "record_split_simp_tac" to split and simplify records added.
  5788 
  5789 * 'specification' command added, allowing for definition by
  5790   specification.  There is also an 'ax_specification' command that
  5791   introduces the new constants axiomatically.
  5792 
  5793 * arith(_tac) is now able to generate counterexamples for reals as well.
  5794 
  5795 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5796 
  5797 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5798   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5799 
  5800 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5801   matrix theory to linear programming.
  5802 
  5803 * Unions and Intersections:
  5804   The latex output syntax of UN and INT has been changed
  5805   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5806   i.e. the index formulae has become a subscript.
  5807   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5808 
  5809 * Unions and Intersections over Intervals:
  5810   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5811   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5812   like in normal math, and corresponding versions for < and for intersection.
  5813 
  5814 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5815   lexicographic dictonary ordering has been added as "lexord".
  5816 
  5817 * ML: the legacy theory structures Int and List have been removed. They had
  5818   conflicted with ML Basis Library structures having the same names.
  5819 
  5820 * 'refute' command added to search for (finite) countermodels.  Only works
  5821   for a fragment of HOL.  The installation of an external SAT solver is
  5822   highly recommended.  See "HOL/Refute.thy" for details.
  5823 
  5824 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5825   formulae under an assignment of free variables to random values.
  5826   In contrast to 'refute', it can deal with inductive datatypes,
  5827   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5828   for examples.
  5829 
  5830 
  5831 *** HOLCF ***
  5832 
  5833 * Streams now come with concatenation and are part of the HOLCF image
  5834 
  5835 
  5836 
  5837 New in Isabelle2003 (May 2003)
  5838 ------------------------------
  5839 
  5840 *** General ***
  5841 
  5842 * Provers/simplifier:
  5843 
  5844   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5845     Assumptions are now subject to complete mutual simplification,
  5846     not just from left to right. The simplifier now preserves
  5847     the order of assumptions.
  5848 
  5849     Potential INCOMPATIBILITY:
  5850 
  5851     -- simp sometimes diverges where the old version did
  5852        not, e.g. invoking simp on the goal
  5853 
  5854         [| P (f x); y = x; f x = f y |] ==> Q
  5855 
  5856        now gives rise to the infinite reduction sequence
  5857 
  5858         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5859 
  5860        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5861        kind of problem.
  5862 
  5863     -- Tactics combining classical reasoner and simplification (such as auto)
  5864        are also affected by this change, because many of them rely on
  5865        simp. They may sometimes diverge as well or yield a different numbers
  5866        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5867        in case of problems. Sometimes subsequent calls to the classical
  5868        reasoner will fail because a preceeding call to the simplifier too
  5869        eagerly simplified the goal, e.g. deleted redundant premises.
  5870 
  5871   - The simplifier trace now shows the names of the applied rewrite rules
  5872 
  5873   - You can limit the number of recursive invocations of the simplifier
  5874     during conditional rewriting (where the simplifie tries to solve the
  5875     conditions before applying the rewrite rule):
  5876     ML "simp_depth_limit := n"
  5877     where n is an integer. Thus you can force termination where previously
  5878     the simplifier would diverge.
  5879 
  5880   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5881 
  5882   - No longer aborts on failed congruence proof.  Instead, the
  5883     congruence is ignored.
  5884 
  5885 * Pure: New generic framework for extracting programs from constructive
  5886   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5887   as HOL/Extraction for some case studies.
  5888 
  5889 * Pure: The main goal of the proof state is no longer shown by default, only
  5890 the subgoals. This behaviour is controlled by a new flag.
  5891    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5892 (ML: Proof.show_main_goal).
  5893 
  5894 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5895 rules whose conclusion matches subgoal 1:
  5896       PG menu: Isabelle/Isar -> Show me -> matching rules
  5897 The rules are ordered by how closely they match the subgoal.
  5898 In particular, rules that solve a subgoal outright are displayed first
  5899 (or rather last, the way they are printed).
  5900 (ML: ProofGeneral.print_intros())
  5901 
  5902 * Pure: New flag trace_unify_fail causes unification to print
  5903 diagnostic information (PG: in trace buffer) when it fails. This is
  5904 useful for figuring out why single step proofs like rule, erule or
  5905 assumption failed.
  5906 
  5907 * Pure: Locale specifications now produce predicate definitions
  5908 according to the body of text (covering assumptions modulo local
  5909 definitions); predicate "loc_axioms" covers newly introduced text,
  5910 while "loc" is cumulative wrt. all included locale expressions; the
  5911 latter view is presented only on export into the global theory
  5912 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5913 on the old view without predicates;
  5914 
  5915 * Pure: predefined locales "var" and "struct" are useful for sharing
  5916 parameters (as in CASL, for example); just specify something like
  5917 ``var x + var y + struct M'' as import;
  5918 
  5919 * Pure: improved thms_containing: proper indexing of facts instead of
  5920 raw theorems; check validity of results wrt. current name space;
  5921 include local facts of proof configuration (also covers active
  5922 locales), cover fixed variables in index; may use "_" in term
  5923 specification; an optional limit for the number of printed facts may
  5924 be given (the default is 40);
  5925 
  5926 * Pure: disallow duplicate fact bindings within new-style theory files
  5927 (batch-mode only);
  5928 
  5929 * Provers: improved induct method: assumptions introduced by case
  5930 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5931 the goal statement); "foo" still refers to all facts collectively;
  5932 
  5933 * Provers: the function blast.overloaded has been removed: all constants
  5934 are regarded as potentially overloaded, which improves robustness in exchange
  5935 for slight decrease in efficiency;
  5936 
  5937 * Provers/linorder: New generic prover for transitivity reasoning over
  5938 linear orders.  Note: this prover is not efficient!
  5939 
  5940 * Isar: preview of problems to finish 'show' now produce an error
  5941 rather than just a warning (in interactive mode);
  5942 
  5943 
  5944 *** HOL ***
  5945 
  5946 * arith(_tac)
  5947 
  5948  - Produces a counter example if it cannot prove a goal.
  5949    Note that the counter example may be spurious if the goal is not a formula
  5950    of quantifier-free linear arithmetic.
  5951    In ProofGeneral the counter example appears in the trace buffer.
  5952 
  5953  - Knows about div k and mod k where k is a numeral of type nat or int.
  5954 
  5955  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5956    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5957    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5958 
  5959 * simp's arithmetic capabilities have been enhanced a bit: it now
  5960 takes ~= in premises into account (by performing a case split);
  5961 
  5962 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5963 are distributed over a sum of terms;
  5964 
  5965 * New tactic "trans_tac" and method "trans" instantiate
  5966 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5967 "<=", "<" and "=").
  5968 
  5969 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5970 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5971 
  5972 * 'typedef' command has new option "open" to suppress the set
  5973 definition;
  5974 
  5975 * functions Min and Max on finite sets have been introduced (theory
  5976 Finite_Set);
  5977 
  5978 * attribute [symmetric] now works for relations as well; it turns
  5979 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5980 
  5981 * induct over a !!-quantified statement (say !!x1..xn):
  5982   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5983 
  5984 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5985 %x. None. Warning: empty_def now refers to the previously hidden definition
  5986 of the empty set.
  5987 
  5988 * Algebra: formalization of classical algebra.  Intended as base for
  5989 any algebraic development in Isabelle.  Currently covers group theory
  5990 (up to Sylow's theorem) and ring theory (Universal Property of
  5991 Univariate Polynomials).  Contributions welcome;
  5992 
  5993 * GroupTheory: deleted, since its material has been moved to Algebra;
  5994 
  5995 * Complex: new directory of the complex numbers with numeric constants,
  5996 nonstandard complex numbers, and some complex analysis, standard and
  5997 nonstandard (Jacques Fleuriot);
  5998 
  5999 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6000 
  6001 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6002 Fleuriot);
  6003 
  6004 * Real/HahnBanach: updated and adapted to locales;
  6005 
  6006 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6007 Gray and Kramer);
  6008 
  6009 * UNITY: added the Meier-Sanders theory of progress sets;
  6010 
  6011 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6012 as abstract algorithms, instantiated to the JVM;
  6013 
  6014 * Bali: Java source language formalization. Type system, operational
  6015 semantics, axiomatic semantics. Supported language features:
  6016 classes, interfaces, objects,virtual methods, static methods,
  6017 static/instance fields, arrays, access modifiers, definite
  6018 assignment, exceptions.
  6019 
  6020 
  6021 *** ZF ***
  6022 
  6023 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6024 universe, etc.);
  6025 
  6026 * Main ZF: virtually all theories converted to new-style format;
  6027 
  6028 
  6029 *** ML ***
  6030 
  6031 * Pure: Tactic.prove provides sane interface for internal proofs;
  6032 omits the infamous "standard" operation, so this is more appropriate
  6033 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6034 
  6035 * Pure: improved error reporting of simprocs;
  6036 
  6037 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6038 up simprocs;
  6039 
  6040 
  6041 *** Document preparation ***
  6042 
  6043 * uses \par instead of \\ for line breaks in theory text. This may
  6044 shift some page breaks in large documents. To get the old behaviour
  6045 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6046 
  6047 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6048 other packages
  6049 
  6050 * \<euro> now needs package babel/greek instead of marvosym (which
  6051 broke \Rightarrow)
  6052 
  6053 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6054 textcomp package)
  6055 
  6056 
  6057 
  6058 New in Isabelle2002 (March 2002)
  6059 --------------------------------
  6060 
  6061 *** Document preparation ***
  6062 
  6063 * greatly simplified document preparation setup, including more
  6064 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6065 instructive isatool mkdir; users should basically be able to get
  6066 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6067 users may run a separate document processing stage manually like this:
  6068 "isatool usedir -D output HOL Test && isatool document Test/output";
  6069 
  6070 * theory dependency graph may now be incorporated into documents;
  6071 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6072 with \includegraphics of LaTeX;
  6073 
  6074 * proper spacing of consecutive markup elements, especially text
  6075 blocks after section headings;
  6076 
  6077 * support bold style (for single symbols only), input syntax is like
  6078 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6079 
  6080 * \<bullet> is now output as bold \cdot by default, which looks much
  6081 better in printed text;
  6082 
  6083 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6084 note that these symbols are currently unavailable in Proof General /
  6085 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6086 
  6087 * isatool latex no longer depends on changed TEXINPUTS, instead
  6088 isatool document copies the Isabelle style files to the target
  6089 location;
  6090 
  6091 
  6092 *** Isar ***
  6093 
  6094 * Pure/Provers: improved proof by cases and induction;
  6095   - 'case' command admits impromptu naming of parameters (such as
  6096     "case (Suc n)");
  6097   - 'induct' method divinates rule instantiation from the inductive
  6098     claim; no longer requires excessive ?P bindings for proper
  6099     instantiation of cases;
  6100   - 'induct' method properly enumerates all possibilities of set/type
  6101     rules; as a consequence facts may be also passed through *type*
  6102     rules without further ado;
  6103   - 'induct' method now derives symbolic cases from the *rulified*
  6104     rule (before it used to rulify cases stemming from the internal
  6105     atomized version); this means that the context of a non-atomic
  6106     statement becomes is included in the hypothesis, avoiding the
  6107     slightly cumbersome show "PROP ?case" form;
  6108   - 'induct' may now use elim-style induction rules without chaining
  6109     facts, using ``missing'' premises from the goal state; this allows
  6110     rules stemming from inductive sets to be applied in unstructured
  6111     scripts, while still benefitting from proper handling of non-atomic
  6112     statements; NB: major inductive premises need to be put first, all
  6113     the rest of the goal is passed through the induction;
  6114   - 'induct' proper support for mutual induction involving non-atomic
  6115     rule statements (uses the new concept of simultaneous goals, see
  6116     below);
  6117   - append all possible rule selections, but only use the first
  6118     success (no backtracking);
  6119   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6120   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6121   - added 'print_induct_rules' (covered by help item in recent Proof
  6122     General versions);
  6123   - moved induct/cases attributes to Pure, methods to Provers;
  6124   - generic method setup instantiated for FOL and HOL;
  6125 
  6126 * Pure: support multiple simultaneous goal statements, for example
  6127 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6128 meta-level mechanism, this acts as if several individual goals had
  6129 been stated separately; in particular common proof methods need to be
  6130 repeated in order to cover all claims; note that a single elimination
  6131 step is *not* sufficient to establish the two conjunctions, so this
  6132 fails:
  6133 
  6134   assume "A & B" then have A and B ..   (*".." fails*)
  6135 
  6136 better use "obtain" in situations as above; alternative refer to
  6137 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6138 
  6139 * Pure: proper integration with ``locales''; unlike the original
  6140 version by Florian Kammller, Isar locales package high-level proof
  6141 contexts rather than raw logical ones (e.g. we admit to include
  6142 attributes everywhere); operations on locales include merge and
  6143 rename; support for implicit arguments (``structures''); simultaneous
  6144 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6145 some examples;
  6146 
  6147 * Pure: the following commands have been ``localized'', supporting a
  6148 target locale specification "(in name)": 'lemma', 'theorem',
  6149 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6150 stored both within the locale and at the theory level (exported and
  6151 qualified by the locale name);
  6152 
  6153 * Pure: theory goals may now be specified in ``long'' form, with
  6154 ad-hoc contexts consisting of arbitrary locale elements. for example
  6155 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6156 definitions may be given, too); the result is a meta-level rule with
  6157 the context elements being discharged in the obvious way;
  6158 
  6159 * Pure: new proof command 'using' allows to augment currently used
  6160 facts after a goal statement ('using' is syntactically analogous to
  6161 'apply', but acts on the goal's facts only); this allows chained facts
  6162 to be separated into parts given before and after a claim, as in
  6163 ``from a and b have C using d and e <proof>'';
  6164 
  6165 * Pure: renamed "antecedent" case to "rule_context";
  6166 
  6167 * Pure: new 'judgment' command records explicit information about the
  6168 object-logic embedding (used by several tools internally); no longer
  6169 use hard-wired "Trueprop";
  6170 
  6171 * Pure: added 'corollary' command;
  6172 
  6173 * Pure: fixed 'token_translation' command;
  6174 
  6175 * Pure: removed obsolete 'exported' attribute;
  6176 
  6177 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6178 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6179 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6180 
  6181 * Pure: method 'atomize' presents local goal premises as object-level
  6182 statements (atomic meta-level propositions); setup controlled via
  6183 rewrite rules declarations of 'atomize' attribute; example
  6184 application: 'induct' method with proper rule statements in improper
  6185 proof *scripts*;
  6186 
  6187 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6188 now consider the syntactic context of assumptions, giving a better
  6189 chance to get type-inference of the arguments right (this is
  6190 especially important for locales);
  6191 
  6192 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6193 mode;
  6194 
  6195 * Pure/obtain: the formal conclusion "thesis", being marked as
  6196 ``internal'', may no longer be reference directly in the text;
  6197 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6198 situations;
  6199 
  6200 * Pure: generic 'sym' attribute which declares a rule both as pure
  6201 'elim?' and for the 'symmetric' operation;
  6202 
  6203 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6204 text; the fixed correlation with particular command syntax has been
  6205 discontinued;
  6206 
  6207 * Pure: new method 'rules' is particularly well-suited for proof
  6208 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6209 but often produces more compact proof terms with less detours;
  6210 
  6211 * Pure/Provers/classical: simplified integration with pure rule
  6212 attributes and methods; the classical "intro?/elim?/dest?"
  6213 declarations coincide with the pure ones; the "rule" method no longer
  6214 includes classically swapped intros; "intro" and "elim" methods no
  6215 longer pick rules from the context; also got rid of ML declarations
  6216 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6217 INCOMPATIBILITY;
  6218 
  6219 * Provers/classical: attribute 'swapped' produces classical inversions
  6220 of introduction rules;
  6221 
  6222 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6223 rules instead of full simplifier context; 'iff' attribute handles
  6224 conditional rules;
  6225 
  6226 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6227 
  6228 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6229 "(permissive)" option to recover old behavior;
  6230