NEWS
author bulwahn
Sat Jul 09 21:18:20 2011 +0200 (2011-07-09)
changeset 43736 d2f7af6e993c
parent 43709 717e96cf9527
child 43737 592b32eb18a6
permissions -rw-r--r--
NEWS
     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     constant field 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 * Antiquotations for ML and document preparation are managed as theory
   153 data, which requires explicit setup.
   154 
   155 * Isabelle_Process.is_active allows tools to check if the official
   156 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   157 (better known as Proof General).
   158 
   159 * Structure Proof_Context follows standard naming scheme.  Old
   160 ProofContext is still available for some time as legacy alias.
   161 
   162 * Structure Timing provides various operations for timing; supersedes
   163 former start_timing/end_timing etc.
   164 
   165 * Path.print is the official way to show file-system paths to users
   166 (including quotes etc.).
   167 
   168 * Inner syntax: identifiers in parse trees of generic categories
   169 "logic", "aprop", "idt" etc. carry position information (disguised as
   170 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   171 translations that choke on unexpected type constraints.  Positions can
   172 be stripped in ML translations via Syntax.strip_positions /
   173 Syntax.strip_positions_ast, or via the syntax constant
   174 "_strip_positions" within parse trees.  As last resort, positions can
   175 be disabled via the configuration option Syntax.positions, which is
   176 called "syntax_positions" in Isar attribute syntax.
   177 
   178 * Discontinued special status of various ML structures that contribute
   179 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   180 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   181 refer directly to Ast.Constant, Lexicon.is_identifier,
   182 Syntax_Trans.mk_binder_tr etc.
   183 
   184 * Typed print translation: discontinued show_sorts argument, which is
   185 already available via context of "advanced" translation.
   186 
   187 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   188 goal states; body tactic needs to address all subgoals uniformly.
   189 
   190 * Slightly more special eq_list/eq_set, with shortcut involving
   191 pointer equality (assumes that eq relation is reflexive).
   192 
   193 * Classical tactics use proper Proof.context instead of historic types
   194 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   195 operate directly on Proof.context.  Raw type claset retains its use as
   196 snapshot of the classical context, which can be recovered via
   197 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   198 INCOMPATIBILITY, classical tactics and derived proof methods require
   199 proper Proof.context.
   200 
   201 
   202 
   203 New in Isabelle2011 (January 2011)
   204 ----------------------------------
   205 
   206 *** General ***
   207 
   208 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   209 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   210 useful tooltips and hyperlinks produced from its static analysis.  The
   211 bundled component provides an executable Isabelle tool that can be run
   212 like this:
   213 
   214   Isabelle2011/bin/isabelle jedit
   215 
   216 * Significantly improved Isabelle/Isar implementation manual.
   217 
   218 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   219 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   220 while the default heap location within that directory lacks that extra
   221 suffix.  This isolates multiple Isabelle installations from each
   222 other, avoiding problems with old settings in new versions.
   223 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   224 
   225 * Source files are always encoded as UTF-8, instead of old-fashioned
   226 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   227 the following package declarations:
   228 
   229   \usepackage[utf8]{inputenc}
   230   \usepackage{textcomp}
   231 
   232 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   233 a Unicode character is treated as a single symbol, not a sequence of
   234 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   235 contain symbols without further backslash escapes, Unicode can now be
   236 used here as well.  Recall that Symbol.explode in ML provides a
   237 consistent view on symbols, while raw explode (or String.explode)
   238 merely give a byte-oriented representation.
   239 
   240 * Theory loader: source files are primarily located via the master
   241 directory of each theory node (where the .thy file itself resides).
   242 The global load path is still partially available as legacy feature.
   243 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   244 explicit paths, relatively to the theory.
   245 
   246 * Special treatment of ML file names has been discontinued.
   247 Historically, optional extensions .ML or .sml were added on demand --
   248 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   249 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   250 
   251 * Various options that affect pretty printing etc. are now properly
   252 handled within the context via configuration options, instead of
   253 unsynchronized references or print modes.  There are both ML Config.T
   254 entities and Isar declaration attributes to access these.
   255 
   256   ML (Config.T)                 Isar (attribute)
   257 
   258   eta_contract                  eta_contract
   259   show_brackets                 show_brackets
   260   show_sorts                    show_sorts
   261   show_types                    show_types
   262   show_question_marks           show_question_marks
   263   show_consts                   show_consts
   264   show_abbrevs                  show_abbrevs
   265 
   266   Syntax.ast_trace              syntax_ast_trace
   267   Syntax.ast_stat               syntax_ast_stat
   268   Syntax.ambiguity_level        syntax_ambiguity_level
   269 
   270   Goal_Display.goals_limit      goals_limit
   271   Goal_Display.show_main_goal   show_main_goal
   272 
   273   Method.rule_trace             rule_trace
   274 
   275   Thy_Output.display            thy_output_display
   276   Thy_Output.quotes             thy_output_quotes
   277   Thy_Output.indent             thy_output_indent
   278   Thy_Output.source             thy_output_source
   279   Thy_Output.break              thy_output_break
   280 
   281 Note that corresponding "..._default" references in ML may only be
   282 changed globally at the ROOT session setup, but *not* within a theory.
   283 The option "show_abbrevs" supersedes the former print mode
   284 "no_abbrevs" with inverted meaning.
   285 
   286 * More systematic naming of some configuration options.
   287 INCOMPATIBILITY.
   288 
   289   trace_simp  ~>  simp_trace
   290   debug_simp  ~>  simp_debug
   291 
   292 * Support for real valued configuration options, using simplistic
   293 floating-point notation that coincides with the inner syntax for
   294 float_token.
   295 
   296 * Support for real valued preferences (with approximative PGIP type):
   297 front-ends need to accept "pgint" values in float notation.
   298 INCOMPATIBILITY.
   299 
   300 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   301 DejaVu Sans.
   302 
   303 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   304 
   305 
   306 *** Pure ***
   307 
   308 * Command 'type_synonym' (with single argument) replaces somewhat
   309 outdated 'types', which is still available as legacy feature for some
   310 time.
   311 
   312 * Command 'nonterminal' (with 'and' separated list of arguments)
   313 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   314 
   315 * Command 'notepad' replaces former 'example_proof' for
   316 experimentation in Isar without any result.  INCOMPATIBILITY.
   317 
   318 * Locale interpretation commands 'interpret' and 'sublocale' accept
   319 lists of equations to map definitions in a locale to appropriate
   320 entities in the context of the interpretation.  The 'interpretation'
   321 command already provided this functionality.
   322 
   323 * Diagnostic command 'print_dependencies' prints the locale instances
   324 that would be activated if the specified expression was interpreted in
   325 the current context.  Variant "print_dependencies!" assumes a context
   326 without interpretations.
   327 
   328 * Diagnostic command 'print_interps' prints interpretations in proofs
   329 in addition to interpretations in theories.
   330 
   331 * Discontinued obsolete 'global' and 'local' commands to manipulate
   332 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   333 Sign.root_path and Sign.local_path may be applied directly where this
   334 feature is still required for historical reasons.
   335 
   336 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   337 'definition' instead.
   338 
   339 * The "prems" fact, which refers to the accidental collection of
   340 foundational premises in the context, is now explicitly marked as
   341 legacy feature and will be discontinued soon.  Consider using "assms"
   342 of the head statement or reference facts by explicit names.
   343 
   344 * Document antiquotations @{class} and @{type} print classes and type
   345 constructors.
   346 
   347 * Document antiquotation @{file} checks file/directory entries within
   348 the local file system.
   349 
   350 
   351 *** HOL ***
   352 
   353 * Coercive subtyping: functions can be declared as coercions and type
   354 inference will add them as necessary upon input of a term.  Theory
   355 Complex_Main declares real :: nat => real and real :: int => real as
   356 coercions. A coercion function f is declared like this:
   357 
   358   declare [[coercion f]]
   359 
   360 To lift coercions through type constructors (e.g. from nat => real to
   361 nat list => real list), map functions can be declared, e.g.
   362 
   363   declare [[coercion_map map]]
   364 
   365 Currently coercion inference is activated only in theories including
   366 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   367 the configuration option "coercion_enabled", e.g. it can be enabled in
   368 other theories like this:
   369 
   370   declare [[coercion_enabled]]
   371 
   372 * Command 'partial_function' provides basic support for recursive
   373 function definitions over complete partial orders.  Concrete instances
   374 are provided for i) the option type, ii) tail recursion on arbitrary
   375 types, and iii) the heap monad of Imperative_HOL.  See
   376 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   377 for examples.
   378 
   379 * Function package: f.psimps rules are no longer implicitly declared
   380 as [simp].  INCOMPATIBILITY.
   381 
   382 * Datatype package: theorems generated for executable equality (class
   383 "eq") carry proper names and are treated as default code equations.
   384 
   385 * Inductive package: now offers command 'inductive_simps' to
   386 automatically derive instantiated and simplified equations for
   387 inductive predicates, similar to 'inductive_cases'.
   388 
   389 * Command 'enriched_type' allows to register properties of the
   390 functorial structure of types.
   391 
   392 * Improved infrastructure for term evaluation using code generator
   393 techniques, in particular static evaluation conversions.
   394 
   395 * Code generator: Scala (2.8 or higher) has been added to the target
   396 languages.
   397 
   398 * Code generator: globbing constant expressions "*" and "Theory.*"
   399 have been replaced by the more idiomatic "_" and "Theory._".
   400 INCOMPATIBILITY.
   401 
   402 * Code generator: export_code without explicit file declaration prints
   403 to standard output.  INCOMPATIBILITY.
   404 
   405 * Code generator: do not print function definitions for case
   406 combinators any longer.
   407 
   408 * Code generator: simplification with rules determined with
   409 src/Tools/Code/code_simp.ML and method "code_simp".
   410 
   411 * Code generator for records: more idiomatic representation of record
   412 types.  Warning: records are not covered by ancient SML code
   413 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   414 rep_datatype declaration helps to succeed then:
   415 
   416   record 'a foo = ...
   417   ...
   418   rep_datatype foo_ext ...
   419 
   420 * Records: logical foundation type for records does not carry a
   421 '_type' suffix any longer (obsolete due to authentic syntax).
   422 INCOMPATIBILITY.
   423 
   424 * Quickcheck now by default uses exhaustive testing instead of random
   425 testing.  Random testing can be invoked by "quickcheck [random]",
   426 exhaustive testing by "quickcheck [exhaustive]".
   427 
   428 * Quickcheck instantiates polymorphic types with small finite
   429 datatypes by default. This enables a simple execution mechanism to
   430 handle quantifiers and function equality over the finite datatypes.
   431 
   432 * Quickcheck random generator has been renamed from "code" to
   433 "random".  INCOMPATIBILITY.
   434 
   435 * Quickcheck now has a configurable time limit which is set to 30
   436 seconds by default. This can be changed by adding [timeout = n] to the
   437 quickcheck command. The time limit for Auto Quickcheck is still set
   438 independently.
   439 
   440 * Quickcheck in locales considers interpretations of that locale for
   441 counter example search.
   442 
   443 * Sledgehammer:
   444   - Added "smt" and "remote_smt" provers based on the "smt" proof
   445     method. See the Sledgehammer manual for details ("isabelle doc
   446     sledgehammer").
   447   - Renamed commands:
   448     sledgehammer atp_info ~> sledgehammer running_provers
   449     sledgehammer atp_kill ~> sledgehammer kill_provers
   450     sledgehammer available_atps ~> sledgehammer available_provers
   451     INCOMPATIBILITY.
   452   - Renamed options:
   453     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   454     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   455     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   456     (and "ms" and "min" are no longer supported)
   457     INCOMPATIBILITY.
   458 
   459 * Nitpick:
   460   - Renamed options:
   461     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   462     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   463     INCOMPATIBILITY.
   464   - Added support for partial quotient types.
   465   - Added local versions of the "Nitpick.register_xxx" functions.
   466   - Added "whack" option.
   467   - Allow registration of quotient types as codatatypes.
   468   - Improved "merge_type_vars" option to merge more types.
   469   - Removed unsound "fast_descrs" option.
   470   - Added custom symmetry breaking for datatypes, making it possible to reach
   471     higher cardinalities.
   472   - Prevent the expansion of too large definitions.
   473 
   474 * Proof methods "metis" and "meson" now have configuration options
   475 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   476 to diagnose these tools. E.g.
   477 
   478     using [[metis_trace = true]]
   479 
   480 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   481 manually as command 'solve_direct'.
   482 
   483 * The default SMT solver Z3 must be enabled explicitly (due to
   484 licensing issues) by setting the environment variable
   485 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   486 commercial applications, the SMT solver CVC3 is provided as fall-back;
   487 changing the SMT solver is done via the configuration option
   488 "smt_solver".
   489 
   490 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   491 i.e. "remote_cvc3" and "remote_z3".
   492 
   493 * Added basic SMT support for datatypes, records, and typedefs using
   494 the oracle mode (no proofs).  Direct support of pairs has been dropped
   495 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   496 support for a similar behavior).  Minor INCOMPATIBILITY.
   497 
   498 * Changed SMT configuration options:
   499   - Renamed:
   500     z3_proofs ~> smt_oracle (with inverted meaning)
   501     z3_trace_assms ~> smt_trace_used_facts
   502     INCOMPATIBILITY.
   503   - Added:
   504     smt_verbose
   505     smt_random_seed
   506     smt_datatypes
   507     smt_infer_triggers
   508     smt_monomorph_limit
   509     cvc3_options
   510     remote_cvc3_options
   511     remote_z3_options
   512     yices_options
   513 
   514 * Boogie output files (.b2i files) need to be declared in the theory
   515 header.
   516 
   517 * Simplification procedure "list_to_set_comprehension" rewrites list
   518 comprehensions applied to List.set to set comprehensions.  Occasional
   519 INCOMPATIBILITY, may be deactivated like this:
   520 
   521   declare [[simproc del: list_to_set_comprehension]]
   522 
   523 * Removed old version of primrec package.  INCOMPATIBILITY.
   524 
   525 * Removed simplifier congruence rule of "prod_case", as has for long
   526 been the case with "split".  INCOMPATIBILITY.
   527 
   528 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   529 
   530 * Removed [split_format ... and ... and ...] version of
   531 [split_format].  Potential INCOMPATIBILITY.
   532 
   533 * Predicate "sorted" now defined inductively, with nice induction
   534 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   535 
   536 * Constant "contents" renamed to "the_elem", to free the generic name
   537 contents for other uses.  INCOMPATIBILITY.
   538 
   539 * Renamed class eq and constant eq (for code generation) to class
   540 equal and constant equal, plus renaming of related facts and various
   541 tuning.  INCOMPATIBILITY.
   542 
   543 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   544 
   545 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   546 INCOMPATIBILITY.
   547 
   548 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   549 avoid confusion with finite sets.  INCOMPATIBILITY.
   550 
   551 * Abandoned locales equiv, congruent and congruent2 for equivalence
   552 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   553 for congruent(2)).
   554 
   555 * Some previously unqualified names have been qualified:
   556 
   557   types
   558     bool ~> HOL.bool
   559     nat ~> Nat.nat
   560 
   561   constants
   562     Trueprop ~> HOL.Trueprop
   563     True ~> HOL.True
   564     False ~> HOL.False
   565     op & ~> HOL.conj
   566     op | ~> HOL.disj
   567     op --> ~> HOL.implies
   568     op = ~> HOL.eq
   569     Not ~> HOL.Not
   570     The ~> HOL.The
   571     All ~> HOL.All
   572     Ex ~> HOL.Ex
   573     Ex1 ~> HOL.Ex1
   574     Let ~> HOL.Let
   575     If ~> HOL.If
   576     Ball ~> Set.Ball
   577     Bex ~> Set.Bex
   578     Suc ~> Nat.Suc
   579     Pair ~> Product_Type.Pair
   580     fst ~> Product_Type.fst
   581     snd ~> Product_Type.snd
   582     curry ~> Product_Type.curry
   583     op : ~> Set.member
   584     Collect ~> Set.Collect
   585 
   586 INCOMPATIBILITY.
   587 
   588 * More canonical naming convention for some fundamental definitions:
   589 
   590     bot_bool_eq ~> bot_bool_def
   591     top_bool_eq ~> top_bool_def
   592     inf_bool_eq ~> inf_bool_def
   593     sup_bool_eq ~> sup_bool_def
   594     bot_fun_eq  ~> bot_fun_def
   595     top_fun_eq  ~> top_fun_def
   596     inf_fun_eq  ~> inf_fun_def
   597     sup_fun_eq  ~> sup_fun_def
   598 
   599 INCOMPATIBILITY.
   600 
   601 * More stylized fact names:
   602 
   603   expand_fun_eq ~> fun_eq_iff
   604   expand_set_eq ~> set_eq_iff
   605   set_ext       ~> set_eqI
   606   nat_number    ~> eval_nat_numeral
   607 
   608 INCOMPATIBILITY.
   609 
   610 * Refactoring of code-generation specific operations in theory List:
   611 
   612   constants
   613     null ~> List.null
   614 
   615   facts
   616     mem_iff ~> member_def
   617     null_empty ~> null_def
   618 
   619 INCOMPATIBILITY.  Note that these were not supposed to be used
   620 regularly unless for striking reasons; their main purpose was code
   621 generation.
   622 
   623 Various operations from the Haskell prelude are used for generating
   624 Haskell code.
   625 
   626 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   627 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   628 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   629 
   630 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   631 "*" and "+" respectively.  INCOMPATIBILITY.
   632 
   633 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   634 "Sum_Type.Plus" instead.
   635 
   636 * Constant "split" has been merged with constant "prod_case"; names of
   637 ML functions, facts etc. involving split have been retained so far,
   638 though.  INCOMPATIBILITY.
   639 
   640 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   641 instead.  INCOMPATIBILITY.
   642 
   643 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   644 INCOMPATIBILITY.
   645 
   646 * Former theory Library/Enum is now part of the HOL-Main image.
   647 INCOMPATIBILITY: all constants of the Enum theory now have to be
   648 referred to by its qualified name.
   649 
   650   enum    ~>  Enum.enum
   651   nlists  ~>  Enum.nlists
   652   product ~>  Enum.product
   653 
   654 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   655 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   656 INCOMPATIBILITY.
   657 
   658 * Theory Library/SetsAndFunctions has been split into
   659 Library/Function_Algebras and Library/Set_Algebras; canonical names
   660 for instance definitions for functions; various improvements.
   661 INCOMPATIBILITY.
   662 
   663 * Theory Library/Multiset provides stable quicksort implementation of
   664 sort_key.
   665 
   666 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   667 INCOMPATIBILITY.
   668 
   669 * Session Multivariate_Analysis: introduced a type class for euclidean
   670 space.  Most theorems are now stated in terms of euclidean spaces
   671 instead of finite cartesian products.
   672 
   673   types
   674     real ^ 'n ~>  'a::real_vector
   675               ~>  'a::euclidean_space
   676               ~>  'a::ordered_euclidean_space
   677         (depends on your needs)
   678 
   679   constants
   680      _ $ _        ~> _ $$ _
   681      \<chi> x. _  ~> \<chi>\<chi> x. _
   682      CARD('n)     ~> DIM('a)
   683 
   684 Also note that the indices are now natural numbers and not from some
   685 finite type. Finite cartesian products of euclidean spaces, products
   686 of euclidean spaces the real and complex numbers are instantiated to
   687 be euclidean_spaces.  INCOMPATIBILITY.
   688 
   689 * Session Probability: introduced pextreal as positive extended real
   690 numbers.  Use pextreal as value for measures.  Introduce the
   691 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   692 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   693 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   694 
   695 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   696 INCOMPATIBILITY.
   697 
   698 * Session SPARK (with image HOL-SPARK) provides commands to load and
   699 prove verification conditions generated by the SPARK Ada program
   700 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   701 
   702 
   703 *** HOL-Algebra ***
   704 
   705 * Theorems for additive ring operations (locale abelian_monoid and
   706 descendants) are generated by interpretation from their multiplicative
   707 counterparts.  Names (in particular theorem names) have the mandatory
   708 qualifier 'add'.  Previous theorem names are redeclared for
   709 compatibility.
   710 
   711 * Structure "int_ring" is now an abbreviation (previously a
   712 definition).  This fits more natural with advanced interpretations.
   713 
   714 
   715 *** HOLCF ***
   716 
   717 * The domain package now runs in definitional mode by default: The
   718 former command 'new_domain' is now called 'domain'.  To use the domain
   719 package in its original axiomatic mode, use 'domain (unsafe)'.
   720 INCOMPATIBILITY.
   721 
   722 * The new class "domain" is now the default sort.  Class "predomain"
   723 is an unpointed version of "domain". Theories can be updated by
   724 replacing sort annotations as shown below.  INCOMPATIBILITY.
   725 
   726   'a::type ~> 'a::countable
   727   'a::cpo  ~> 'a::predomain
   728   'a::pcpo ~> 'a::domain
   729 
   730 * The old type class "rep" has been superseded by class "domain".
   731 Accordingly, users of the definitional package must remove any
   732 "default_sort rep" declarations.  INCOMPATIBILITY.
   733 
   734 * The domain package (definitional mode) now supports unpointed
   735 predomain argument types, as long as they are marked 'lazy'. (Strict
   736 arguments must be in class "domain".) For example, the following
   737 domain definition now works:
   738 
   739   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   740 
   741 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   742 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   743 'a option, and 'a list.  Additionally, it configures fixrec and the
   744 domain package to work with these types.  For example:
   745 
   746   fixrec isInl :: "('a + 'b) u -> tr"
   747     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   748 
   749   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   750 
   751 * The "(permissive)" option of fixrec has been replaced with a
   752 per-equation "(unchecked)" option. See
   753 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   754 
   755 * The "bifinite" class no longer fixes a constant "approx"; the class
   756 now just asserts that such a function exists.  INCOMPATIBILITY.
   757 
   758 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   759 defines an embedding of type 'a defl into udom by default; instances
   760 of "bifinite" and "domain" classes are available in
   761 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   762 
   763 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   764 
   765 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   766 
   767 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   768 
   769 * The function "cprod_map" has been renamed to "prod_map".
   770 INCOMPATIBILITY.
   771 
   772 * The monadic bind operator on each powerdomain has new binder syntax
   773 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   774 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   775 
   776 * The infix syntax for binary union on each powerdomain has changed
   777 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   778 syntax.  INCOMPATIBILITY.
   779 
   780 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   781 still supported as an input translation.
   782 
   783 * Renamed some theorems (the original names are also still available).
   784 
   785   expand_fun_below   ~> fun_below_iff
   786   below_fun_ext      ~> fun_belowI
   787   expand_cfun_eq     ~> cfun_eq_iff
   788   ext_cfun           ~> cfun_eqI
   789   expand_cfun_below  ~> cfun_below_iff
   790   below_cfun_ext     ~> cfun_belowI
   791   cont2cont_Rep_CFun ~> cont2cont_APP
   792 
   793 * The Abs and Rep functions for various types have changed names.
   794 Related theorem names have also changed to match. INCOMPATIBILITY.
   795 
   796   Rep_CFun  ~> Rep_cfun
   797   Abs_CFun  ~> Abs_cfun
   798   Rep_Sprod ~> Rep_sprod
   799   Abs_Sprod ~> Abs_sprod
   800   Rep_Ssum  ~> Rep_ssum
   801   Abs_Ssum  ~> Abs_ssum
   802 
   803 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   804 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   805 
   806 * Various changes to bisimulation/coinduction with domain package:
   807 
   808   - Definitions of "bisim" constants no longer mention definedness.
   809   - With mutual recursion, "bisim" predicate is now curried.
   810   - With mutual recursion, each type gets a separate coind theorem.
   811   - Variable names in bisim_def and coinduct rules have changed.
   812 
   813 INCOMPATIBILITY.
   814 
   815 * Case combinators generated by the domain package for type "foo" are
   816 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   817 
   818 * Several theorems have been renamed to more accurately reflect the
   819 names of constants and types involved.  INCOMPATIBILITY.
   820 
   821   thelub_const    ~> lub_const
   822   lub_const       ~> is_lub_const
   823   thelubI         ~> lub_eqI
   824   is_lub_lub      ~> is_lubD2
   825   lubI            ~> is_lub_lub
   826   unique_lub      ~> is_lub_unique
   827   is_ub_lub       ~> is_lub_rangeD1
   828   lub_bin_chain   ~> is_lub_bin_chain
   829   lub_fun         ~> is_lub_fun
   830   thelub_fun      ~> lub_fun
   831   thelub_cfun     ~> lub_cfun
   832   thelub_Pair     ~> lub_Pair
   833   lub_cprod       ~> is_lub_prod
   834   thelub_cprod    ~> lub_prod
   835   minimal_cprod   ~> minimal_prod
   836   inst_cprod_pcpo ~> inst_prod_pcpo
   837   UU_I            ~> bottomI
   838   compact_UU      ~> compact_bottom
   839   deflation_UU    ~> deflation_bottom
   840   finite_deflation_UU ~> finite_deflation_bottom
   841 
   842 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   843 
   844   sq_ord_less_eq_trans ~> below_eq_trans
   845   sq_ord_eq_less_trans ~> eq_below_trans
   846   refl_less            ~> below_refl
   847   trans_less           ~> below_trans
   848   antisym_less         ~> below_antisym
   849   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   850   box_less             ~> box_below
   851   rev_trans_less       ~> rev_below_trans
   852   not_less2not_eq      ~> not_below2not_eq
   853   less_UU_iff          ~> below_UU_iff
   854   flat_less_iff        ~> flat_below_iff
   855   adm_less             ~> adm_below
   856   adm_not_less         ~> adm_not_below
   857   adm_compact_not_less ~> adm_compact_not_below
   858   less_fun_def         ~> below_fun_def
   859   expand_fun_less      ~> fun_below_iff
   860   less_fun_ext         ~> fun_belowI
   861   less_discr_def       ~> below_discr_def
   862   discr_less_eq        ~> discr_below_eq
   863   less_unit_def        ~> below_unit_def
   864   less_cprod_def       ~> below_prod_def
   865   prod_lessI           ~> prod_belowI
   866   Pair_less_iff        ~> Pair_below_iff
   867   fst_less_iff         ~> fst_below_iff
   868   snd_less_iff         ~> snd_below_iff
   869   expand_cfun_less     ~> cfun_below_iff
   870   less_cfun_ext        ~> cfun_belowI
   871   injection_less       ~> injection_below
   872   less_up_def          ~> below_up_def
   873   not_Iup_less         ~> not_Iup_below
   874   Iup_less             ~> Iup_below
   875   up_less              ~> up_below
   876   Def_inject_less_eq   ~> Def_below_Def
   877   Def_less_is_eq       ~> Def_below_iff
   878   spair_less_iff       ~> spair_below_iff
   879   less_sprod           ~> below_sprod
   880   spair_less           ~> spair_below
   881   sfst_less_iff        ~> sfst_below_iff
   882   ssnd_less_iff        ~> ssnd_below_iff
   883   fix_least_less       ~> fix_least_below
   884   dist_less_one        ~> dist_below_one
   885   less_ONE             ~> below_ONE
   886   ONE_less_iff         ~> ONE_below_iff
   887   less_sinlD           ~> below_sinlD
   888   less_sinrD           ~> below_sinrD
   889 
   890 
   891 *** FOL and ZF ***
   892 
   893 * All constant names are now qualified internally and use proper
   894 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   895 
   896 
   897 *** ML ***
   898 
   899 * Antiquotation @{assert} inlines a function bool -> unit that raises
   900 Fail if the argument is false.  Due to inlining the source position of
   901 failed assertions is included in the error output.
   902 
   903 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   904 text is in practice always evaluated with a stable theory checkpoint.
   905 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   906 
   907 * Antiquotation @{theory A} refers to theory A from the ancestry of
   908 the current context, not any accidental theory loader state as before.
   909 Potential INCOMPATIBILITY, subtle change in semantics.
   910 
   911 * Syntax.pretty_priority (default 0) configures the required priority
   912 of pretty-printed output and thus affects insertion of parentheses.
   913 
   914 * Syntax.default_root (default "any") configures the inner syntax
   915 category (nonterminal symbol) for parsing of terms.
   916 
   917 * Former exception Library.UnequalLengths now coincides with
   918 ListPair.UnequalLengths.
   919 
   920 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   921 main functionality is provided by structure Simplifier.
   922 
   923 * Renamed raw "explode" function to "raw_explode" to emphasize its
   924 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   925 almost all situations.
   926 
   927 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   928 See implementation manual for further details on exceptions in
   929 Isabelle/ML.
   930 
   931 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   932 meaning.
   933 
   934 * Renamed structure PureThy to Pure_Thy and moved most of its
   935 operations to structure Global_Theory, to emphasize that this is
   936 rarely-used global-only stuff.
   937 
   938 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   939 instead (or tracing for high-volume output).
   940 
   941 * Configuration option show_question_marks only affects regular pretty
   942 printing of types and terms, not raw Term.string_of_vname.
   943 
   944 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   945 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   946 @{thms} for most purposes.
   947 
   948 * ML structure Unsynchronized is never opened, not even in Isar
   949 interaction mode as before.  Old Unsynchronized.set etc. have been
   950 discontinued -- use plain := instead.  This should be *rare* anyway,
   951 since modern tools always work via official context data, notably
   952 configuration options.
   953 
   954 * Parallel and asynchronous execution requires special care concerning
   955 interrupts.  Structure Exn provides some convenience functions that
   956 avoid working directly with raw Interrupt.  User code must not absorb
   957 interrupts -- intermediate handling (for cleanup etc.) needs to be
   958 followed by re-raising of the original exception.  Another common
   959 source of mistakes are "handle _" patterns, which make the meaning of
   960 the program subject to physical effects of the environment.
   961 
   962 
   963 
   964 New in Isabelle2009-2 (June 2010)
   965 ---------------------------------
   966 
   967 *** General ***
   968 
   969 * Authentic syntax for *all* logical entities (type classes, type
   970 constructors, term constants): provides simple and robust
   971 correspondence between formal entities and concrete syntax.  Within
   972 the parse tree / AST representations, "constants" are decorated by
   973 their category (class, type, const) and spelled out explicitly with
   974 their full internal name.
   975 
   976 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   977 and translations (translation rules and translation functions in ML).
   978 Some hints on upgrading:
   979 
   980   - Many existing uses of 'syntax' and 'translations' can be replaced
   981     by more modern 'type_notation', 'notation' and 'abbreviation',
   982     which are independent of this issue.
   983 
   984   - 'translations' require markup within the AST; the term syntax
   985     provides the following special forms:
   986 
   987       CONST c   -- produces syntax version of constant c from context
   988       XCONST c  -- literally c, checked as constant from context
   989       c         -- literally c, if declared by 'syntax'
   990 
   991     Plain identifiers are treated as AST variables -- occasionally the
   992     system indicates accidental variables via the error "rhs contains
   993     extra variables".
   994 
   995     Type classes and type constructors are marked according to their
   996     concrete syntax.  Some old translations rules need to be written
   997     for the "type" category, using type constructor application
   998     instead of pseudo-term application of the default category
   999     "logic".
  1000 
  1001   - 'parse_translation' etc. in ML may use the following
  1002     antiquotations:
  1003 
  1004       @{class_syntax c}   -- type class c within parse tree / AST
  1005       @{term_syntax c}    -- type constructor c within parse tree / AST
  1006       @{const_syntax c}   -- ML version of "CONST c" above
  1007       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1008 
  1009   - Literal types within 'typed_print_translations', i.e. those *not*
  1010     represented as pseudo-terms are represented verbatim.  Use @{class
  1011     c} or @{type_name c} here instead of the above syntax
  1012     antiquotations.
  1013 
  1014 Note that old non-authentic syntax was based on unqualified base
  1015 names, so all of the above "constant" names would coincide.  Recall
  1016 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1017 diagnose syntax problems.
  1018 
  1019 * Type constructors admit general mixfix syntax, not just infix.
  1020 
  1021 * Concrete syntax may be attached to local entities without a proof
  1022 body, too.  This works via regular mixfix annotations for 'fix',
  1023 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1024 similar to the 'notation' command in theory specifications.
  1025 
  1026 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1027 need to specify constant name and syntax separately.  Internal ML
  1028 datatype constructors have been renamed from InfixName to Infix etc.
  1029 Minor INCOMPATIBILITY.
  1030 
  1031 * Schematic theorem statements need to be explicitly markup as such,
  1032 via commands 'schematic_lemma', 'schematic_theorem',
  1033 'schematic_corollary'.  Thus the relevance of the proof is made
  1034 syntactically clear, which impacts performance in a parallel or
  1035 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1036 
  1037 * Use of cumulative prems via "!" in some proof methods has been
  1038 discontinued (old legacy feature).
  1039 
  1040 * References 'trace_simp' and 'debug_simp' have been replaced by
  1041 configuration options stored in the context. Enabling tracing (the
  1042 case of debugging is similar) in proofs works via
  1043 
  1044   using [[trace_simp = true]]
  1045 
  1046 Tracing is then active for all invocations of the simplifier in
  1047 subsequent goal refinement steps. Tracing may also still be enabled or
  1048 disabled via the ProofGeneral settings menu.
  1049 
  1050 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1051 'hide_fact' replace the former 'hide' KIND command.  Minor
  1052 INCOMPATIBILITY.
  1053 
  1054 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1055 more efficient than combinations with -q1 or -q2.
  1056 
  1057 
  1058 *** Pure ***
  1059 
  1060 * Proofterms record type-class reasoning explicitly, using the
  1061 "unconstrain" operation internally.  This eliminates all sort
  1062 constraints from a theorem and proof, introducing explicit
  1063 OFCLASS-premises.  On the proof term level, this operation is
  1064 automatically applied at theorem boundaries, such that closed proofs
  1065 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1066 inspect proof terms.
  1067 
  1068 * Local theory specifications may depend on extra type variables that
  1069 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1070 are added internally.  For example:
  1071 
  1072   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1073 
  1074 * Predicates of locales introduced by classes carry a mandatory
  1075 "class" prefix.  INCOMPATIBILITY.
  1076 
  1077 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1078 
  1079 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1080 'class' instead.
  1081 
  1082 * Command 'code_reflect' allows to incorporate generated ML code into
  1083 runtime environment; replaces immature code_datatype antiquotation.
  1084 INCOMPATIBILITY.
  1085 
  1086 * Code generator: simple concept for abstract datatypes obeying
  1087 invariants.
  1088 
  1089 * Code generator: details of internal data cache have no impact on the
  1090 user space functionality any longer.
  1091 
  1092 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1093 subgoals.  This is more appropriate for interpretations with 'where'.
  1094 INCOMPATIBILITY.
  1095 
  1096 * Command 'example_proof' opens an empty proof body.  This allows to
  1097 experiment with Isar, without producing any persistent result.
  1098 
  1099 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1100 within a local theory context, with explicit checking of the
  1101 constructors involved (in contrast to the raw 'syntax' versions).
  1102 
  1103 * Commands 'types' and 'typedecl' now work within a local theory
  1104 context -- without introducing dependencies on parameters or
  1105 assumptions, which is not possible in Isabelle/Pure.
  1106 
  1107 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1108 within a local theory context.  Minor INCOMPATIBILITY.
  1109 
  1110 
  1111 *** HOL ***
  1112 
  1113 * Command 'typedef' now works within a local theory context -- without
  1114 introducing dependencies on parameters or assumptions, which is not
  1115 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1116 contain multiple interpretations of local typedefs (with different
  1117 non-emptiness proofs), even in a global theory context.
  1118 
  1119 * New package for quotient types.  Commands 'quotient_type' and
  1120 'quotient_definition' may be used for defining types and constants by
  1121 quotient constructions.  An example is the type of integers created by
  1122 quotienting pairs of natural numbers:
  1123 
  1124   fun
  1125     intrel :: "(nat * nat) => (nat * nat) => bool"
  1126   where
  1127     "intrel (x, y) (u, v) = (x + v = u + y)"
  1128 
  1129   quotient_type int = "nat * nat" / intrel
  1130     by (auto simp add: equivp_def expand_fun_eq)
  1131 
  1132   quotient_definition
  1133     "0::int" is "(0::nat, 0::nat)"
  1134 
  1135 The method "lifting" can be used to lift of theorems from the
  1136 underlying "raw" type to the quotient type.  The example
  1137 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1138 construction and provides a reasoning infrastructure for finite sets.
  1139 
  1140 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1141 clash with new theory Quotient in Main HOL.
  1142 
  1143 * Moved the SMT binding into the main HOL session, eliminating
  1144 separate HOL-SMT session.
  1145 
  1146 * List membership infix mem operation is only an input abbreviation.
  1147 INCOMPATIBILITY.
  1148 
  1149 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1150 for future developements; former Library/Word.thy is still present in
  1151 the AFP entry RSAPPS.
  1152 
  1153 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1154 longer shadowed.  INCOMPATIBILITY.
  1155 
  1156 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1157 INCOMPATIBILITY.
  1158 
  1159 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1160 INCOMPATIBILITY.
  1161 
  1162 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1163 instead.  INCOMPATIBILITY.
  1164 
  1165 * Dropped several real-specific versions of lemmas about floor and
  1166 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1167 instead.  INCOMPATIBILITY.
  1168 
  1169   floor_number_of_eq         ~> floor_number_of
  1170   le_floor_eq_number_of      ~> number_of_le_floor
  1171   le_floor_eq_zero           ~> zero_le_floor
  1172   le_floor_eq_one            ~> one_le_floor
  1173   floor_less_eq_number_of    ~> floor_less_number_of
  1174   floor_less_eq_zero         ~> floor_less_zero
  1175   floor_less_eq_one          ~> floor_less_one
  1176   less_floor_eq_number_of    ~> number_of_less_floor
  1177   less_floor_eq_zero         ~> zero_less_floor
  1178   less_floor_eq_one          ~> one_less_floor
  1179   floor_le_eq_number_of      ~> floor_le_number_of
  1180   floor_le_eq_zero           ~> floor_le_zero
  1181   floor_le_eq_one            ~> floor_le_one
  1182   floor_subtract_number_of   ~> floor_diff_number_of
  1183   floor_subtract_one         ~> floor_diff_one
  1184   ceiling_number_of_eq       ~> ceiling_number_of
  1185   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1186   ceiling_le_zero_eq         ~> ceiling_le_zero
  1187   ceiling_le_eq_one          ~> ceiling_le_one
  1188   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1189   less_ceiling_eq_zero       ~> zero_less_ceiling
  1190   less_ceiling_eq_one        ~> one_less_ceiling
  1191   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1192   ceiling_less_eq_zero       ~> ceiling_less_zero
  1193   ceiling_less_eq_one        ~> ceiling_less_one
  1194   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1195   le_ceiling_eq_zero         ~> zero_le_ceiling
  1196   le_ceiling_eq_one          ~> one_le_ceiling
  1197   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1198   ceiling_subtract_one       ~> ceiling_diff_one
  1199 
  1200 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1201 application of the various fold combinators on finite sets.
  1202 
  1203 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1204 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1205 implementation.  INCOMPATIBILTY.
  1206 
  1207 * Theory Library/Coinductive_List has been removed -- superseded by
  1208 AFP/thys/Coinductive.
  1209 
  1210 * Theory PReal, including the type "preal" and related operations, has
  1211 been removed.  INCOMPATIBILITY.
  1212 
  1213 * Real: new development using Cauchy Sequences.
  1214 
  1215 * Split off theory "Big_Operators" containing setsum, setprod,
  1216 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1217 
  1218 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1219 "Int" etc.  INCOMPATIBILITY.
  1220 
  1221 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1222 
  1223 * New set of rules "ac_simps" provides combined assoc / commute
  1224 rewrites for all interpretations of the appropriate generic locales.
  1225 
  1226 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1227 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1228 appropriate and more consistent names suitable for name prefixes
  1229 within the HOL theories.  INCOMPATIBILITY.
  1230 
  1231 * Some generic constants have been put to appropriate theories:
  1232   - less_eq, less: Orderings
  1233   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1234   - inverse, divide: Rings
  1235 INCOMPATIBILITY.
  1236 
  1237 * More consistent naming of type classes involving orderings (and
  1238 lattices):
  1239 
  1240     lower_semilattice                   ~> semilattice_inf
  1241     upper_semilattice                   ~> semilattice_sup
  1242 
  1243     dense_linear_order                  ~> dense_linorder
  1244 
  1245     pordered_ab_group_add               ~> ordered_ab_group_add
  1246     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1247     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1248     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1249     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1250     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1251     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1252     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1253     pordered_comm_ring                  ~> ordered_comm_ring
  1254     pordered_comm_semiring              ~> ordered_comm_semiring
  1255     pordered_ring                       ~> ordered_ring
  1256     pordered_ring_abs                   ~> ordered_ring_abs
  1257     pordered_semiring                   ~> ordered_semiring
  1258 
  1259     ordered_ab_group_add                ~> linordered_ab_group_add
  1260     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1261     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1262     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1263     ordered_field                       ~> linordered_field
  1264     ordered_field_no_lb                 ~> linordered_field_no_lb
  1265     ordered_field_no_ub                 ~> linordered_field_no_ub
  1266     ordered_field_dense_linear_order    ~> dense_linordered_field
  1267     ordered_idom                        ~> linordered_idom
  1268     ordered_ring                        ~> linordered_ring
  1269     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1270     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1271     ordered_ring_strict                 ~> linordered_ring_strict
  1272     ordered_semidom                     ~> linordered_semidom
  1273     ordered_semiring                    ~> linordered_semiring
  1274     ordered_semiring_1                  ~> linordered_semiring_1
  1275     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1276     ordered_semiring_strict             ~> linordered_semiring_strict
  1277 
  1278   The following slightly odd type classes have been moved to a
  1279   separate theory Library/Lattice_Algebras:
  1280 
  1281     lordered_ab_group_add               ~> lattice_ab_group_add
  1282     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1283     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1284     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1285     lordered_ring                       ~> lattice_ring
  1286 
  1287 INCOMPATIBILITY.
  1288 
  1289 * Refined field classes:
  1290   - classes division_ring_inverse_zero, field_inverse_zero,
  1291     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1292     subsumes former division_by_zero class;
  1293   - numerous lemmas have been ported from field to division_ring.
  1294 INCOMPATIBILITY.
  1295 
  1296 * Refined algebra theorem collections:
  1297   - dropped theorem group group_simps, use algebra_simps instead;
  1298   - dropped theorem group ring_simps, use field_simps instead;
  1299   - proper theorem collection field_simps subsumes former theorem
  1300     groups field_eq_simps and field_simps;
  1301   - dropped lemma eq_minus_self_iff which is a duplicate for
  1302     equal_neg_zero.
  1303 INCOMPATIBILITY.
  1304 
  1305 * Theory Finite_Set and List: some lemmas have been generalized from
  1306 sets to lattices:
  1307 
  1308   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1309   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1310   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1311   union_Union_fold_union        ~> sup_Sup_fold_sup
  1312   Inter_fold_inter              ~> Inf_fold_inf
  1313   Union_fold_union              ~> Sup_fold_sup
  1314   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1315   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1316   INTER_fold_inter              ~> INFI_fold_inf
  1317   UNION_fold_union              ~> SUPR_fold_sup
  1318 
  1319 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1320 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1321 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1322 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1323 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1324 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1325 
  1326 * Reorganized theory Multiset: swapped notation of pointwise and
  1327 multiset order:
  1328 
  1329   - pointwise ordering is instance of class order with standard syntax
  1330     <= and <;
  1331   - multiset ordering has syntax <=# and <#; partial order properties
  1332     are provided by means of interpretation with prefix
  1333     multiset_order;
  1334   - less duplication, less historical organization of sections,
  1335     conversion from associations lists to multisets, rudimentary code
  1336     generation;
  1337   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1338     if needed.
  1339 
  1340 Renamed:
  1341 
  1342   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1343   multi_count_ext  ~>  multiset_ext
  1344   diff_union_inverse2  ~>  diff_union_cancelR
  1345 
  1346 INCOMPATIBILITY.
  1347 
  1348 * Theory Permutation: replaced local "remove" by List.remove1.
  1349 
  1350 * Code generation: ML and OCaml code is decorated with signatures.
  1351 
  1352 * Theory List: added transpose.
  1353 
  1354 * Library/Nat_Bijection.thy is a collection of bijective functions
  1355 between nat and other types, which supersedes the older libraries
  1356 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1357 
  1358   Constants:
  1359   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1360   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1361   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1362   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1363   Countable.pair_encode           ~> prod_encode
  1364   NatIso.prod2nat                 ~> prod_encode
  1365   NatIso.nat2prod                 ~> prod_decode
  1366   NatIso.sum2nat                  ~> sum_encode
  1367   NatIso.nat2sum                  ~> sum_decode
  1368   NatIso.list2nat                 ~> list_encode
  1369   NatIso.nat2list                 ~> list_decode
  1370   NatIso.set2nat                  ~> set_encode
  1371   NatIso.nat2set                  ~> set_decode
  1372 
  1373   Lemmas:
  1374   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1375   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1376   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1377   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1378   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1379   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1380   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1381   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1382   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1383   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1384   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1385   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1386   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1387 
  1388 * Sledgehammer:
  1389   - Renamed ATP commands:
  1390     atp_info     ~> sledgehammer running_atps
  1391     atp_kill     ~> sledgehammer kill_atps
  1392     atp_messages ~> sledgehammer messages
  1393     atp_minimize ~> sledgehammer minimize
  1394     print_atps   ~> sledgehammer available_atps
  1395     INCOMPATIBILITY.
  1396   - Added user's manual ("isabelle doc sledgehammer").
  1397   - Added option syntax and "sledgehammer_params" to customize
  1398     Sledgehammer's behavior.  See the manual for details.
  1399   - Modified the Isar proof reconstruction code so that it produces
  1400     direct proofs rather than proofs by contradiction.  (This feature
  1401     is still experimental.)
  1402   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1403     full-typed mode.
  1404   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1405 
  1406 * Nitpick:
  1407   - Added and implemented "binary_ints" and "bits" options.
  1408   - Added "std" option and implemented support for nonstandard models.
  1409   - Added and implemented "finitize" option to improve the precision
  1410     of infinite datatypes based on a monotonicity analysis.
  1411   - Added support for quotient types.
  1412   - Added support for "specification" and "ax_specification"
  1413     constructs.
  1414   - Added support for local definitions (for "function" and
  1415     "termination" proofs).
  1416   - Added support for term postprocessors.
  1417   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1418   - Improved efficiency of "destroy_constrs" optimization.
  1419   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1420     record getters.
  1421   - Fixed soundness bug related to higher-order constructors.
  1422   - Fixed soundness bug when "full_descrs" is enabled.
  1423   - Improved precision of set constructs.
  1424   - Added "atoms" option.
  1425   - Added cache to speed up repeated Kodkod invocations on the same
  1426     problems.
  1427   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1428     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1429     "SAT4J_Light".  INCOMPATIBILITY.
  1430   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1431     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1432   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1433 
  1434 * Method "induct" now takes instantiations of the form t, where t is not
  1435   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1436   If this is not intended, t has to be enclosed in parentheses.
  1437   By default, the equalities generated by definitional instantiations
  1438   are pre-simplified, which may cause parameters of inductive cases
  1439   to disappear, or may even delete some of the inductive cases.
  1440   Use "induct (no_simp)" instead of "induct" to restore the old
  1441   behaviour. The (no_simp) option is also understood by the "cases"
  1442   and "nominal_induct" methods, which now perform pre-simplification, too.
  1443   INCOMPATIBILITY.
  1444 
  1445 
  1446 *** HOLCF ***
  1447 
  1448 * Variable names in lemmas generated by the domain package have
  1449 changed; the naming scheme is now consistent with the HOL datatype
  1450 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1451 
  1452 * The domain package no longer defines the function "foo_copy" for
  1453 recursive domain "foo".  The reach lemma is now stated directly in
  1454 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1455 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1456 
  1457 * Most definedness lemmas generated by the domain package (previously
  1458 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1459 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1460 Proofs that used definedness lemmas as intro rules may break,
  1461 potential INCOMPATIBILITY.
  1462 
  1463 * Induction and casedist rules generated by the domain package now
  1464 declare proper case_names (one called "bottom", and one named for each
  1465 constructor).  INCOMPATIBILITY.
  1466 
  1467 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1468 rules are generated for each domain, INCOMPATIBILITY.
  1469 
  1470   foo_bar.reach       ~> foo.reach  bar.reach
  1471   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1472 
  1473 * Some lemmas generated by the domain package have been renamed for
  1474 consistency with the datatype package, INCOMPATIBILITY.
  1475 
  1476   foo.ind        ~> foo.induct
  1477   foo.finite_ind ~> foo.finite_induct
  1478   foo.coind      ~> foo.coinduct
  1479   foo.casedist   ~> foo.exhaust
  1480   foo.exhaust    ~> foo.nchotomy
  1481 
  1482 * For consistency with other definition packages, the fixrec package
  1483 now generates qualified theorem names, INCOMPATIBILITY.
  1484 
  1485   foo_simps  ~> foo.simps
  1486   foo_unfold ~> foo.unfold
  1487   foo_induct ~> foo.induct
  1488 
  1489 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1490 method and internal fixrec proofs now use the default simpset instead.
  1491 INCOMPATIBILITY.
  1492 
  1493 * The "contlub" predicate has been removed.  Proof scripts should use
  1494 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1495 
  1496 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1497 
  1498 * The constants cpair, cfst, and csnd have been removed in favor of
  1499 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1500 
  1501 
  1502 *** ML ***
  1503 
  1504 * Antiquotations for basic formal entities:
  1505 
  1506     @{class NAME}         -- type class
  1507     @{class_syntax NAME}  -- syntax representation of the above
  1508 
  1509     @{type_name NAME}     -- logical type
  1510     @{type_abbrev NAME}   -- type abbreviation
  1511     @{nonterminal NAME}   -- type of concrete syntactic category
  1512     @{type_syntax NAME}   -- syntax representation of any of the above
  1513 
  1514     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1515     @{const_abbrev NAME}  -- abbreviated constant
  1516     @{const_syntax NAME}  -- syntax representation of any of the above
  1517 
  1518 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1519 syntax constant (cf. 'syntax' command).
  1520 
  1521 * Antiquotation @{make_string} inlines a function to print arbitrary
  1522 values similar to the ML toplevel.  The result is compiler dependent
  1523 and may fall back on "?" in certain situations.
  1524 
  1525 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1526 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1527 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1528 not work with the asynchronous Isar document model.
  1529 
  1530 * Configuration options now admit dynamic default values, depending on
  1531 the context or even global references.
  1532 
  1533 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1534 uses an efficient external library if available (for Poly/ML).
  1535 
  1536 * Renamed some important ML structures, while keeping the old names
  1537 for some time as aliases within the structure Legacy:
  1538 
  1539   OuterKeyword  ~>  Keyword
  1540   OuterLex      ~>  Token
  1541   OuterParse    ~>  Parse
  1542   OuterSyntax   ~>  Outer_Syntax
  1543   PrintMode     ~>  Print_Mode
  1544   SpecParse     ~>  Parse_Spec
  1545   ThyInfo       ~>  Thy_Info
  1546   ThyLoad       ~>  Thy_Load
  1547   ThyOutput     ~>  Thy_Output
  1548   TypeInfer     ~>  Type_Infer
  1549 
  1550 Note that "open Legacy" simplifies porting of sources, but forgetting
  1551 to remove it again will complicate porting again in the future.
  1552 
  1553 * Most operations that refer to a global context are named
  1554 accordingly, e.g. Simplifier.global_context or
  1555 ProofContext.init_global.  There are some situations where a global
  1556 context actually works, but under normal circumstances one needs to
  1557 pass the proper local context through the code!
  1558 
  1559 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1560 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1561 Pretty.pp argument to merge, which is absent in the standard
  1562 Theory_Data version.
  1563 
  1564 * Sorts.certify_sort and derived "cert" operations for types and terms
  1565 no longer minimize sorts.  Thus certification at the boundary of the
  1566 inference kernel becomes invariant under addition of class relations,
  1567 which is an important monotonicity principle.  Sorts are now minimized
  1568 in the syntax layer only, at the boundary between the end-user and the
  1569 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1570 explicitly in rare situations.
  1571 
  1572 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1573 emphasize that this is in no way a standard operation.
  1574 INCOMPATIBILITY.
  1575 
  1576 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1577 usual for resolution.  Rare INCOMPATIBILITY.
  1578 
  1579 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1580 to emphasize that these only work in a global situation (which is
  1581 quite rare).
  1582 
  1583 * Curried take and drop in library.ML; negative length is interpreted
  1584 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1585 
  1586 * Proof terms: type substitutions on proof constants now use canonical
  1587 order of type variables.  INCOMPATIBILITY for tools working with proof
  1588 terms.
  1589 
  1590 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1591 may no longer carry premises.  User-level specifications are
  1592 transformed accordingly by Thm.add_axiom/add_def.
  1593 
  1594 
  1595 *** System ***
  1596 
  1597 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1598 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1599 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1600 
  1601 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1602 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1603 respectively.
  1604 
  1605 * Old lib/scripts/polyml-platform is superseded by the
  1606 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1607 variant, even on a 64 bit machine.  The following example setting
  1608 prefers 64 bit if available:
  1609 
  1610   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1611 
  1612 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1613 Isabelle/Scala layer for advanced prover interaction and integration.
  1614 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1615 component.
  1616 
  1617 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1618 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1619 similar to the default assignment of the document preparation system
  1620 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1621 provides some operations for direct access to the font without asking
  1622 the user for manual installation.
  1623 
  1624 
  1625 
  1626 New in Isabelle2009-1 (December 2009)
  1627 -------------------------------------
  1628 
  1629 *** General ***
  1630 
  1631 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1632 one backslash should be used, even in ML sources.
  1633 
  1634 
  1635 *** Pure ***
  1636 
  1637 * Locale interpretation propagates mixins along the locale hierarchy.
  1638 The currently only available mixins are the equations used to map
  1639 local definitions to terms of the target domain of an interpretation.
  1640 
  1641 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1642 loc" to print all interpretations of locale "loc" in the theory.
  1643 Interpretations in proofs are not shown.
  1644 
  1645 * Thoroughly revised locales tutorial.  New section on conditional
  1646 interpretation.
  1647 
  1648 * On instantiation of classes, remaining undefined class parameters
  1649 are formally declared.  INCOMPATIBILITY.
  1650 
  1651 
  1652 *** Document preparation ***
  1653 
  1654 * New generalized style concept for printing terms: @{foo (style) ...}
  1655 instead of @{foo_style style ...}  (old form is still retained for
  1656 backward compatibility).  Styles can be also applied for
  1657 antiquotations prop, term_type and typeof.
  1658 
  1659 
  1660 *** HOL ***
  1661 
  1662 * New proof method "smt" for a combination of first-order logic with
  1663 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1664 fixed-size bitvectors; there is also basic support for higher-order
  1665 features (esp. lambda abstractions).  It is an incomplete decision
  1666 procedure based on external SMT solvers using the oracle mechanism;
  1667 for the SMT solver Z3, this method is proof-producing.  Certificates
  1668 are provided to avoid calling the external solvers solely for
  1669 re-checking proofs.  Due to a remote SMT service there is no need for
  1670 installing SMT solvers locally.  See src/HOL/SMT.
  1671 
  1672 * New commands to load and prove verification conditions generated by
  1673 the Boogie program verifier or derived systems (e.g. the Verifying C
  1674 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1675 
  1676 * New counterexample generator tool 'nitpick' based on the Kodkod
  1677 relational model finder.  See src/HOL/Tools/Nitpick and
  1678 src/HOL/Nitpick_Examples.
  1679 
  1680 * New commands 'code_pred' and 'values' to invoke the predicate
  1681 compiler and to enumerate values of inductive predicates.
  1682 
  1683 * A tabled implementation of the reflexive transitive closure.
  1684 
  1685 * New implementation of quickcheck uses generic code generator;
  1686 default generators are provided for all suitable HOL types, records
  1687 and datatypes.  Old quickcheck can be re-activated importing theory
  1688 Library/SML_Quickcheck.
  1689 
  1690 * New testing tool Mirabelle for automated proof tools.  Applies
  1691 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1692 every proof step in a theory.  To be used in batch mode via the
  1693 "mirabelle" utility.
  1694 
  1695 * New proof method "sos" (sum of squares) for nonlinear real
  1696 arithmetic (originally due to John Harison). It requires theory
  1697 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1698 works well in practice on quantifier-free real arithmetic with +, -,
  1699 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1700 inequalities between polynomials.  It makes use of external
  1701 semidefinite programming solvers.  Method "sos" generates a
  1702 certificate that can be pasted into the proof thus avoiding the need
  1703 to call an external tool every time the proof is checked.  See
  1704 src/HOL/Library/Sum_Of_Squares.
  1705 
  1706 * New method "linarith" invokes existing linear arithmetic decision
  1707 procedure only.
  1708 
  1709 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1710 
  1711 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1712 Causes full type information to be output to the ATPs.  This slows
  1713 ATPs down considerably but eliminates a source of unsound "proofs"
  1714 that fail later.
  1715 
  1716 * New method "metisFT": A version of metis that uses full type
  1717 information in order to avoid failures of proof reconstruction.
  1718 
  1719 * New evaluator "approximate" approximates an real valued term using
  1720 the same method as the approximation method.
  1721 
  1722 * Method "approximate" now supports arithmetic expressions as
  1723 boundaries of intervals and implements interval splitting and Taylor
  1724 series expansion.
  1725 
  1726 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1727 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1728 
  1729 * New theory SupInf of the supremum and infimum operators for sets of
  1730 reals.
  1731 
  1732 * New theory Probability, which contains a development of measure
  1733 theory, eventually leading to Lebesgue integration and probability.
  1734 
  1735 * Extended Multivariate Analysis to include derivation and Brouwer's
  1736 fixpoint theorem.
  1737 
  1738 * Reorganization of number theory, INCOMPATIBILITY:
  1739   - new number theory development for nat and int, in theories Divides
  1740     and GCD as well as in new session Number_Theory
  1741   - some constants and facts now suffixed with _nat and _int
  1742     accordingly
  1743   - former session NumberTheory now named Old_Number_Theory, including
  1744     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1745   - moved theory Pocklington from src/HOL/Library to
  1746     src/HOL/Old_Number_Theory
  1747 
  1748 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1749 lcm of finite and infinite sets. It is shown that they form a complete
  1750 lattice.
  1751 
  1752 * Class semiring_div requires superclass no_zero_divisors and proof of
  1753 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1754 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1755 generalized to class semiring_div, subsuming former theorems
  1756 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1757 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1758 INCOMPATIBILITY.
  1759 
  1760 * Refinements to lattice classes and sets:
  1761   - less default intro/elim rules in locale variant, more default
  1762     intro/elim rules in class variant: more uniformity
  1763   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1764     le_inf_iff
  1765   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1766     sup_aci)
  1767   - renamed ACI to inf_sup_aci
  1768   - new class "boolean_algebra"
  1769   - class "complete_lattice" moved to separate theory
  1770     "Complete_Lattice"; corresponding constants (and abbreviations)
  1771     renamed and with authentic syntax:
  1772     Set.Inf ~>    Complete_Lattice.Inf
  1773     Set.Sup ~>    Complete_Lattice.Sup
  1774     Set.INFI ~>   Complete_Lattice.INFI
  1775     Set.SUPR ~>   Complete_Lattice.SUPR
  1776     Set.Inter ~>  Complete_Lattice.Inter
  1777     Set.Union ~>  Complete_Lattice.Union
  1778     Set.INTER ~>  Complete_Lattice.INTER
  1779     Set.UNION ~>  Complete_Lattice.UNION
  1780   - authentic syntax for
  1781     Set.Pow
  1782     Set.image
  1783   - mere abbreviations:
  1784     Set.empty               (for bot)
  1785     Set.UNIV                (for top)
  1786     Set.inter               (for inf, formerly Set.Int)
  1787     Set.union               (for sup, formerly Set.Un)
  1788     Complete_Lattice.Inter  (for Inf)
  1789     Complete_Lattice.Union  (for Sup)
  1790     Complete_Lattice.INTER  (for INFI)
  1791     Complete_Lattice.UNION  (for SUPR)
  1792   - object-logic definitions as far as appropriate
  1793 
  1794 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1795 Un_subset_iff are explicitly deleted as default simp rules; then also
  1796 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1797 deleted to achieve the desired effect.
  1798 
  1799 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1800 rules by default any longer; the same applies to min_max.inf_absorb1
  1801 etc.  INCOMPATIBILITY.
  1802 
  1803 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1804 pred_set_conv by default.  INCOMPATIBILITY.
  1805 
  1806 * Power operations on relations and functions are now one dedicated
  1807 constant "compow" with infix syntax "^^".  Power operation on
  1808 multiplicative monoids retains syntax "^" and is now defined generic
  1809 in class power.  INCOMPATIBILITY.
  1810 
  1811 * Relation composition "R O S" now has a more standard argument order:
  1812 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1813 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1814 break, since the O_assoc rule was not rewritten like this.  Fix using
  1815 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1816 
  1817 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1818 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1819 INCOMPATIBILITY.
  1820 
  1821 * Most rules produced by inductive and datatype package have mandatory
  1822 prefixes.  INCOMPATIBILITY.
  1823 
  1824 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1825 the attribute of the same name.  Each of the theorems in the list
  1826 DERIV_intros assumes composition with an additional function and
  1827 matches a variable to the derivative, which has to be solved by the
  1828 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1829 of most elementary terms.  Former Maclauren.DERIV_tac and
  1830 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1831 INCOMPATIBILITY.
  1832 
  1833 * Code generator attributes follow the usual underscore convention:
  1834     code_unfold     replaces    code unfold
  1835     code_post       replaces    code post
  1836     etc.
  1837   INCOMPATIBILITY.
  1838 
  1839 * Renamed methods:
  1840     sizechange -> size_change
  1841     induct_scheme -> induction_schema
  1842   INCOMPATIBILITY.
  1843 
  1844 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1845 INCOMPATIBILITY, use "undefined" directly.
  1846 
  1847 * Renamed theorems:
  1848     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1849     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1850     Suc_plus1 -> Suc_eq_plus1
  1851     *anti_sym -> *antisym*
  1852     vector_less_eq_def -> vector_le_def
  1853   INCOMPATIBILITY.
  1854 
  1855 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1856 INCOMPATIBILITY.
  1857 
  1858 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1859 INCOMPATIBILITY.
  1860 
  1861 
  1862 *** HOLCF ***
  1863 
  1864 * Theory Representable defines a class "rep" of domains that are
  1865 representable (via an ep-pair) in the universal domain type "udom".
  1866 Instances are provided for all type constructors defined in HOLCF.
  1867 
  1868 * The 'new_domain' command is a purely definitional version of the
  1869 domain package, for representable domains.  Syntax is identical to the
  1870 old domain package.  The 'new_domain' package also supports indirect
  1871 recursion using previously-defined type constructors.  See
  1872 src/HOLCF/ex/New_Domain.thy for examples.
  1873 
  1874 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1875 on the left-hand side of an equation, and then performs
  1876 simplification.  Rewriting is done using rules declared with the
  1877 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1878 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1879 
  1880 * The pattern-match compiler in 'fixrec' can now handle constructors
  1881 with HOL function types.  Pattern-match combinators for the Pair
  1882 constructor are pre-configured.
  1883 
  1884 * The 'fixrec' package now produces better fixed-point induction rules
  1885 for mutually-recursive definitions:  Induction rules have conclusions
  1886 of the form "P foo bar" instead of "P <foo, bar>".
  1887 
  1888 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1889 been renamed to "below".  The name "below" now replaces "less" in many
  1890 theorem names.  (Legacy theorem names using "less" are still supported
  1891 as well.)
  1892 
  1893 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1894 patterns can be used to generate strictness rules, or to make
  1895 functions more strict (much like the bang-patterns supported by the
  1896 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1897 examples.
  1898 
  1899 
  1900 *** ML ***
  1901 
  1902 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1903 errors and run-time exceptions, including detailed source positions.
  1904 
  1905 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1906 identified entries, with some additional information such as source
  1907 position, logical grouping etc.
  1908 
  1909 * Theory and context data is now introduced by the simplified and
  1910 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1911 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1912 copy operation) is still available for some time.
  1913 
  1914 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1915 provides a high-level programming interface to synchronized state
  1916 variables with atomic update.  This works via pure function
  1917 application within a critical section -- its runtime should be as
  1918 short as possible; beware of deadlocks if critical code is nested,
  1919 either directly or indirectly via other synchronized variables!
  1920 
  1921 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1922 wraps raw ML references, explicitly indicating their non-thread-safe
  1923 behaviour.  The Isar toplevel keeps this structure open, to
  1924 accommodate Proof General as well as quick and dirty interactive
  1925 experiments with references.
  1926 
  1927 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1928 parallel tactical reasoning.
  1929 
  1930 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1931 are similar to SUBPROOF, but are slightly more flexible: only the
  1932 specified parts of the subgoal are imported into the context, and the
  1933 body tactic may introduce new subgoals and schematic variables.
  1934 
  1935 * Old tactical METAHYPS, which does not observe the proof context, has
  1936 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1937 or Subgoal.FOCUS etc.
  1938 
  1939 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1940 functors have their own ML name space there is no point to mark them
  1941 separately.)  Minor INCOMPATIBILITY.
  1942 
  1943 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1944 
  1945 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1946 INCOMPATIBILITY.
  1947 
  1948 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1949 mode, which avoids critical setmp.
  1950 
  1951 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1952 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1953 Attrib/Method.setup introduced in Isabelle2009.
  1954 
  1955 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1956 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1957 last resort.  INCOMPATIBILITY.
  1958 
  1959 * Display.pretty_thm now requires a proper context (cf. former
  1960 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1961 or even Display.pretty_thm_without_context as last resort.
  1962 INCOMPATIBILITY.
  1963 
  1964 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1965 Syntax.pretty_typ/term directly, preferably with proper context
  1966 instead of global theory.
  1967 
  1968 
  1969 *** System ***
  1970 
  1971 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1972 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1973 usedir option -q.
  1974 
  1975 * Support for additional "Isabelle components" via etc/components, see
  1976 also the system manual.
  1977 
  1978 * The isabelle makeall tool now operates on all components with
  1979 IsaMakefile, not just hardwired "logics".
  1980 
  1981 * Removed "compress" option from isabelle-process and isabelle usedir;
  1982 this is always enabled.
  1983 
  1984 * Discontinued support for Poly/ML 4.x versions.
  1985 
  1986 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1987 on a given logic image.  This requires the lighttpd webserver and is
  1988 currently supported on Linux only.
  1989 
  1990 
  1991 
  1992 New in Isabelle2009 (April 2009)
  1993 --------------------------------
  1994 
  1995 *** General ***
  1996 
  1997 * Simplified main Isabelle executables, with less surprises on
  1998 case-insensitive file-systems (such as Mac OS).
  1999 
  2000   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2001     "isatool."
  2002 
  2003   - The former "isabelle" alias for "isabelle-process" has been
  2004     removed (should rarely occur to regular users).
  2005 
  2006   - The former "isabelle-interface" and its alias "Isabelle" have been
  2007     removed (interfaces are now regular Isabelle tools).
  2008 
  2009 Within scripts and make files, the Isabelle environment variables
  2010 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2011 respectively.  (The latter are still available as legacy feature.)
  2012 
  2013 The old isabelle-interface wrapper could react in confusing ways if
  2014 the interface was uninstalled or changed otherwise.  Individual
  2015 interface tool configuration is now more explicit, see also the
  2016 Isabelle system manual.  In particular, Proof General is now available
  2017 via "isabelle emacs".
  2018 
  2019 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2020 purge installed copies of Isabelle executables and re-run "isabelle
  2021 install -p ...", or use symlinks.
  2022 
  2023 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2024 old ~/isabelle, which was slightly non-standard and apt to cause
  2025 surprises on case-insensitive file-systems (such as Mac OS).
  2026 
  2027 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2028 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2029 care is required when using older releases of Isabelle.  Note that
  2030 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2031 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2032 
  2033 * Proofs of fully specified statements are run in parallel on
  2034 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2035 a regular 4-core machine, if the initial heap space is made reasonably
  2036 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2037 
  2038 * The main reference manuals ("isar-ref", "implementation", and
  2039 "system") have been updated and extended.  Formally checked references
  2040 as hyperlinks are now available uniformly.
  2041 
  2042 
  2043 *** Pure ***
  2044 
  2045 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2046 respects.  The most important changes are listed below.  See the
  2047 Tutorial on Locales ("locales" manual) for details.
  2048 
  2049 - In locale expressions, instantiation replaces renaming.  Parameters
  2050 must be declared in a for clause.  To aid compatibility with previous
  2051 parameter inheritance, in locale declarations, parameters that are not
  2052 'touched' (instantiation position "_" or omitted) are implicitly added
  2053 with their syntax at the beginning of the for clause.
  2054 
  2055 - Syntax from abbreviations and definitions in locales is available in
  2056 locale expressions and context elements.  The latter is particularly
  2057 useful in locale declarations.
  2058 
  2059 - More flexible mechanisms to qualify names generated by locale
  2060 expressions.  Qualifiers (prefixes) may be specified in locale
  2061 expressions, and can be marked as mandatory (syntax: "name!:") or
  2062 optional (syntax "name?:").  The default depends for plain "name:"
  2063 depends on the situation where a locale expression is used: in
  2064 commands 'locale' and 'sublocale' prefixes are optional, in
  2065 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2066 implicit qualifiers derived from the parameter names of a locale are
  2067 no longer generated.
  2068 
  2069 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2070 instantiation clause in "interpretation" and "interpret" (square
  2071 brackets) is no longer available.  Use locale expressions.
  2072 
  2073 - When converting proof scripts, mandatory qualifiers in
  2074 'interpretation' and 'interpret' should be retained by default, even
  2075 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2076 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2077 in locale expressions range over a single locale instance only.
  2078 
  2079 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2080 In existing theorem specifications replace the includes element by the
  2081 respective context elements of the included locale, omitting those
  2082 that are already present in the theorem specification.  Multiple
  2083 assume elements of a locale should be replaced by a single one
  2084 involving the locale predicate.  In the proof body, declarations (most
  2085 notably theorems) may be regained by interpreting the respective
  2086 locales in the proof context as required (command "interpret").
  2087 
  2088 If using "includes" in replacement of a target solely because the
  2089 parameter types in the theorem are not as general as in the target,
  2090 consider declaring a new locale with additional type constraints on
  2091 the parameters (context element "constrains").
  2092 
  2093 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2094 
  2095 - Locale interpretation commands no longer attempt to simplify goal.
  2096 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2097 methods intro_locales and unfold_locales to clarify.
  2098 
  2099 - Locale interpretation commands no longer accept interpretation
  2100 attributes.  INCOMPATIBILITY.
  2101 
  2102 * Class declaration: so-called "base sort" must not be given in import
  2103 list any longer, but is inferred from the specification.  Particularly
  2104 in HOL, write
  2105 
  2106     class foo = ...
  2107 
  2108 instead of
  2109 
  2110     class foo = type + ...
  2111 
  2112 * Class target: global versions of theorems stemming do not carry a
  2113 parameter prefix any longer.  INCOMPATIBILITY.
  2114 
  2115 * Class 'instance' command no longer accepts attached definitions.
  2116 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2117 
  2118 * Recovered hiding of consts, which was accidentally broken in
  2119 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2120 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2121 
  2122 * Slightly more coherent Pure syntax, with updated documentation in
  2123 isar-ref manual.  Removed locales meta_term_syntax and
  2124 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2125 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2126 directly in regular applications.
  2127 
  2128 * There is a new syntactic category "float_const" for signed decimal
  2129 fractions (e.g. 123.45 or -123.45).
  2130 
  2131 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2132 interface with 'setup' command instead.
  2133 
  2134 * Command 'local_setup' is similar to 'setup', but operates on a local
  2135 theory context.
  2136 
  2137 * The 'axiomatization' command now only works within a global theory
  2138 context.  INCOMPATIBILITY.
  2139 
  2140 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2141 hypotheses.  Sorts required in the course of reasoning need to be
  2142 covered by the constraints in the initial statement, completed by the
  2143 type instance information of the background theory.  Non-trivial sort
  2144 hypotheses, which rarely occur in practice, may be specified via
  2145 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2146 
  2147   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2148 
  2149 The result contains an implicit sort hypotheses as before --
  2150 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2151 normalization.
  2152 
  2153 * Generalized Isar history, with support for linear undo, direct state
  2154 addressing etc.
  2155 
  2156 * Changed defaults for unify configuration options:
  2157 
  2158   unify_trace_bound = 50 (formerly 25)
  2159   unify_search_bound = 60 (formerly 30)
  2160 
  2161 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2162 
  2163   a) On theory merge, the last set of code equations for a particular
  2164      constant is taken (in accordance with the policy applied by other
  2165      parts of the code generator framework).
  2166 
  2167   b) Code equations stemming from explicit declarations (e.g. code
  2168      attribute) gain priority over default code equations stemming
  2169      from definition, primrec, fun etc.
  2170 
  2171 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2172 
  2173 * Unified theorem tables for both code generators.  Thus [code
  2174 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2175 
  2176 * Command 'find_consts' searches for constants based on type and name
  2177 patterns, e.g.
  2178 
  2179     find_consts "_ => bool"
  2180 
  2181 By default, matching is against subtypes, but it may be restricted to
  2182 the whole type.  Searching by name is possible.  Multiple queries are
  2183 conjunctive and queries may be negated by prefixing them with a
  2184 hyphen:
  2185 
  2186     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2187 
  2188 * New 'find_theorems' criterion "solves" matches theorems that
  2189 directly solve the current goal (modulo higher-order unification).
  2190 
  2191 * Auto solve feature for main theorem statements: whenever a new goal
  2192 is stated, "find_theorems solves" is called; any theorems that could
  2193 solve the lemma directly are listed as part of the goal state.
  2194 Cf. associated options in Proof General Isabelle settings menu,
  2195 enabled by default, with reasonable timeout for pathological cases of
  2196 higher-order unification.
  2197 
  2198 
  2199 *** Document preparation ***
  2200 
  2201 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2202 demanding keyword 'by' and supporting the full method expression
  2203 syntax just like the Isar command 'by'.
  2204 
  2205 
  2206 *** HOL ***
  2207 
  2208 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2209 points Main and Complex_Main remain as before.
  2210 
  2211 * Logic image HOL-Plain provides a minimal HOL with the most important
  2212 tools available (inductive, datatype, primrec, ...).  This facilitates
  2213 experimentation and tool development.  Note that user applications
  2214 (and library theories) should never refer to anything below theory
  2215 Main, as before.
  2216 
  2217 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2218 experimentation due to shorter build times.
  2219 
  2220 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2221 were previously part of former HOL-Complex.  Entry point Hyperreal
  2222 remains valid, but theories formerly using Complex_Main should now use
  2223 new entry point Hypercomplex.
  2224 
  2225 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2226 Posix processes.  Avoids potentially expensive forking of the ML
  2227 process.  New thread-based implementation also works on non-Unix
  2228 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2229 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2230 commands are covered in the isar-ref manual.
  2231 
  2232 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2233 sledgehammer without local ATP installation (Vampire etc.). Other
  2234 provers may be included via suitable ML wrappers, see also
  2235 src/HOL/ATP_Linkup.thy.
  2236 
  2237 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2238 menu.
  2239 
  2240 * The metis method no longer fails because the theorem is too trivial
  2241 (contains the empty clause).
  2242 
  2243 * The metis method now fails in the usual manner, rather than raising
  2244 an exception, if it determines that it cannot prove the theorem.
  2245 
  2246 * Method "coherent" implements a prover for coherent logic (see also
  2247 src/Tools/coherent.ML).
  2248 
  2249 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2250 "undefined" is the right choice to replace "arbitrary", though
  2251 logically there is no difference.  INCOMPATIBILITY.
  2252 
  2253 * Command "value" now integrates different evaluation mechanisms.  The
  2254 result of the first successful evaluation mechanism is printed.  In
  2255 square brackets a particular named evaluation mechanisms may be
  2256 specified (currently, [SML], [code] or [nbe]).  See further
  2257 src/HOL/ex/Eval_Examples.thy.
  2258 
  2259 * Normalization by evaluation now allows non-leftlinear equations.
  2260 Declare with attribute [code nbe].
  2261 
  2262 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2263 as the structured Isar versions "cases" and "induct", cf. the
  2264 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2265 are now presented as a list of individual projections
  2266 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2267 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2268 rare situations a different rule is selected --- notably nested tuple
  2269 elimination instead of former prod.exhaust: use explicit (case_tac t
  2270 rule: prod.exhaust) here.
  2271 
  2272 * Attributes "cases", "induct", "coinduct" support "del" option.
  2273 
  2274 * Removed fact "case_split_thm", which duplicates "case_split".
  2275 
  2276 * The option datatype has been moved to a new theory Option.  Renamed
  2277 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2278 
  2279 * New predicate "strict_mono" classifies strict functions on partial
  2280 orders.  With strict functions on linear orders, reasoning about
  2281 (in)equalities is facilitated by theorems "strict_mono_eq",
  2282 "strict_mono_less_eq" and "strict_mono_less".
  2283 
  2284 * Some set operations are now proper qualified constants with
  2285 authentic syntax.  INCOMPATIBILITY:
  2286 
  2287     op Int ~>   Set.Int
  2288     op Un ~>    Set.Un
  2289     INTER ~>    Set.INTER
  2290     UNION ~>    Set.UNION
  2291     Inter ~>    Set.Inter
  2292     Union ~>    Set.Union
  2293     {} ~>       Set.empty
  2294     UNIV ~>     Set.UNIV
  2295 
  2296 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2297 theory Set.
  2298 
  2299 * Auxiliary class "itself" has disappeared -- classes without any
  2300 parameter are treated as expected by the 'class' command.
  2301 
  2302 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2303 
  2304 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2305 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2306 
  2307 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2308 method "approximation".  It proves formulas on real values by using
  2309 interval arithmetic.  In the formulas are also the transcendental
  2310 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2311 allowed. For examples see
  2312 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2313 
  2314 * Theory "Reflection" now resides in HOL/Library.
  2315 
  2316 * Entry point to Word library now simply named "Word".
  2317 INCOMPATIBILITY.
  2318 
  2319 * Made source layout more coherent with logical distribution
  2320 structure:
  2321 
  2322     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2323     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2324     src/HOL/Library/GCD.thy ~> src/HOL/
  2325     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2326     src/HOL/Library/Parity.thy ~> src/HOL/
  2327     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2328     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2329     src/HOL/Real/Lubs.thy ~> src/HOL/
  2330     src/HOL/Real/PReal.thy ~> src/HOL/
  2331     src/HOL/Real/Rational.thy ~> src/HOL/
  2332     src/HOL/Real/RComplete.thy ~> src/HOL/
  2333     src/HOL/Real/RealDef.thy ~> src/HOL/
  2334     src/HOL/Real/RealPow.thy ~> src/HOL/
  2335     src/HOL/Real/Real.thy ~> src/HOL/
  2336     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2337     src/HOL/Complex/Complex.thy ~> src/HOL/
  2338     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2339     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2340     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2341     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2342     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2343     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2344     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2345     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2346     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2347     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2348     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2349     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2350     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2351     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2352     src/HOL/Real/Float ~> src/HOL/Library/
  2353     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2354     src/HOL/Real/RealVector.thy ~> src/HOL/
  2355 
  2356     src/HOL/arith_data.ML ~> src/HOL/Tools
  2357     src/HOL/hologic.ML ~> src/HOL/Tools
  2358     src/HOL/simpdata.ML ~> src/HOL/Tools
  2359     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2360     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2361     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2362     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2363     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2364     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2365     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2366 
  2367     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2368     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2369     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2370     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2371     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2372     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2373 
  2374 * If methods "eval" and "evaluation" encounter a structured proof
  2375 state with !!/==>, only the conclusion is evaluated to True (if
  2376 possible), avoiding strange error messages.
  2377 
  2378 * Method "sizechange" automates termination proofs using (a
  2379 modification of) the size-change principle.  Requires SAT solver.  See
  2380 src/HOL/ex/Termination.thy for examples.
  2381 
  2382 * Simplifier: simproc for let expressions now unfolds if bound
  2383 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2384 
  2385 * Method "arith": Linear arithmetic now ignores all inequalities when
  2386 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2387 
  2388 * New attribute "arith" for facts that should always be used
  2389 automatically by arithmetic. It is intended to be used locally in
  2390 proofs, e.g.
  2391 
  2392   assumes [arith]: "x > 0"
  2393 
  2394 Global usage is discouraged because of possible performance impact.
  2395 
  2396 * New classes "top" and "bot" with corresponding operations "top" and
  2397 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2398 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2399 
  2400 * Changed definition lemma "less_fun_def" in order to provide an
  2401 instance for preorders on functions; use lemma "less_le" instead.
  2402 INCOMPATIBILITY.
  2403 
  2404 * Theory Orderings: class "wellorder" moved here, with explicit
  2405 induction rule "less_induct" as assumption.  For instantiation of
  2406 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2407 INCOMPATIBILITY.
  2408 
  2409 * Theory Orderings: added class "preorder" as superclass of "order".
  2410 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2411 etc. slightly changed.  Some theorems named order_class.* now named
  2412 preorder_class.*.
  2413 
  2414 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2415 "diag" to "Id_on".
  2416 
  2417 * Theory Finite_Set: added a new fold combinator of type
  2418 
  2419   ('a => 'b => 'b) => 'b => 'a set => 'b
  2420 
  2421 Occasionally this is more convenient than the old fold combinator
  2422 which is now defined in terms of the new one and renamed to
  2423 fold_image.
  2424 
  2425 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2426 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2427 extended with further lemmas!).  At the moment both still exist but
  2428 the former will disappear at some point.
  2429 
  2430 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2431 class recpower.  Type-specific simp rules for various recpower types
  2432 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2433 
  2434 rat_power_0    -> power_0
  2435 rat_power_Suc  -> power_Suc
  2436 realpow_0      -> power_0
  2437 realpow_Suc    -> power_Suc
  2438 complexpow_0   -> power_0
  2439 complexpow_Suc -> power_Suc
  2440 power_poly_0   -> power_0
  2441 power_poly_Suc -> power_Suc
  2442 
  2443 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2444 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2445 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2446 of lemmas from Divides has been generalized from nat to class
  2447 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2448 renames resulting from duplicate elimination:
  2449 
  2450     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2451     zero_dvd_iff ~>         dvd_0_left_iff
  2452     dvd_0 ~>                dvd_0_right
  2453     DIVISION_BY_ZERO_DIV ~> div_by_0
  2454     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2455     mult_div ~>             div_mult_self2_is_id
  2456     mult_mod ~>             mod_mult_self2_is_0
  2457 
  2458 * Theory IntDiv: removed many lemmas that are instances of class-based
  2459 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2460 rename old lemmas as follows:
  2461 
  2462 dvd_diff               -> nat_dvd_diff
  2463 dvd_zminus_iff         -> dvd_minus_iff
  2464 mod_add1_eq            -> mod_add_eq
  2465 mod_mult1_eq           -> mod_mult_right_eq
  2466 mod_mult1_eq'          -> mod_mult_left_eq
  2467 mod_mult_distrib_mod   -> mod_mult_eq
  2468 nat_mod_add_left_eq    -> mod_add_left_eq
  2469 nat_mod_add_right_eq   -> mod_add_right_eq
  2470 nat_mod_div_trivial    -> mod_div_trivial
  2471 nat_mod_mod_trivial    -> mod_mod_trivial
  2472 zdiv_zadd_self1        -> div_add_self1
  2473 zdiv_zadd_self2        -> div_add_self2
  2474 zdiv_zmult_self1       -> div_mult_self2_is_id
  2475 zdiv_zmult_self2       -> div_mult_self1_is_id
  2476 zdvd_triv_left         -> dvd_triv_left
  2477 zdvd_triv_right        -> dvd_triv_right
  2478 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2479 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2480 zmod_zadd_left_eq      -> mod_add_left_eq
  2481 zmod_zadd_right_eq     -> mod_add_right_eq
  2482 zmod_zadd_self1        -> mod_add_self1
  2483 zmod_zadd_self2        -> mod_add_self2
  2484 zmod_zadd1_eq          -> mod_add_eq
  2485 zmod_zdiff1_eq         -> mod_diff_eq
  2486 zmod_zdvd_zmod         -> mod_mod_cancel
  2487 zmod_zmod_cancel       -> mod_mod_cancel
  2488 zmod_zmult_self1       -> mod_mult_self2_is_0
  2489 zmod_zmult_self2       -> mod_mult_self1_is_0
  2490 zmod_1                 -> mod_by_1
  2491 zdiv_1                 -> div_by_1
  2492 zdvd_abs1              -> abs_dvd_iff
  2493 zdvd_abs2              -> dvd_abs_iff
  2494 zdvd_refl              -> dvd_refl
  2495 zdvd_trans             -> dvd_trans
  2496 zdvd_zadd              -> dvd_add
  2497 zdvd_zdiff             -> dvd_diff
  2498 zdvd_zminus_iff        -> dvd_minus_iff
  2499 zdvd_zminus2_iff       -> minus_dvd_iff
  2500 zdvd_zmultD            -> dvd_mult_right
  2501 zdvd_zmultD2           -> dvd_mult_left
  2502 zdvd_zmult_mono        -> mult_dvd_mono
  2503 zdvd_0_right           -> dvd_0_right
  2504 zdvd_0_left            -> dvd_0_left_iff
  2505 zdvd_1_left            -> one_dvd
  2506 zminus_dvd_iff         -> minus_dvd_iff
  2507 
  2508 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2509 
  2510 * The real numbers offer decimal input syntax: 12.34 is translated
  2511 into 1234/10^2. This translation is not reversed upon output.
  2512 
  2513 * Theory Library/Polynomial defines an abstract type 'a poly of
  2514 univariate polynomials with coefficients of type 'a.  In addition to
  2515 the standard ring operations, it also supports div and mod.  Code
  2516 generation is also supported, using list-style constructors.
  2517 
  2518 * Theory Library/Inner_Product defines a class of real_inner for real
  2519 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2520 => real.  Class real_inner is a subclass of real_normed_vector from
  2521 theory RealVector.
  2522 
  2523 * Theory Library/Product_Vector provides instances for the product
  2524 type 'a * 'b of several classes from RealVector and Inner_Product.
  2525 Definitions of addition, subtraction, scalar multiplication, norms,
  2526 and inner products are included.
  2527 
  2528 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2529 addition to the field operations, numerals and case syntax are also
  2530 supported.
  2531 
  2532 * Theory Library/Diagonalize provides constructive version of Cantor's
  2533 first diagonalization argument.
  2534 
  2535 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2536 zlcm (for int); carried together from various gcd/lcm developements in
  2537 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2538 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2539 may recover tupled syntax as follows:
  2540 
  2541     hide (open) const gcd
  2542     abbreviation gcd where
  2543       "gcd == (%(a, b). GCD.gcd a b)"
  2544     notation (output)
  2545       GCD.gcd ("gcd '(_, _')")
  2546 
  2547 The same works for lcm, zgcd, zlcm.
  2548 
  2549 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2550 instantiations for algebraic structures.  Removed some duplicate
  2551 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2552 
  2553 * ML antiquotation @{code} takes a constant as argument and generates
  2554 corresponding code in background and inserts name of the corresponding
  2555 resulting ML value/function/datatype constructor binding in place.
  2556 All occurrences of @{code} with a single ML block are generated
  2557 simultaneously.  Provides a generic and safe interface for
  2558 instrumentalizing code generation.  See
  2559 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2560 In future you ought to refrain from ad-hoc compiling generated SML
  2561 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2562 cannot refer to constants for which user-defined serializations are
  2563 set.  Refer to the corresponding ML counterpart directly in that
  2564 cases.
  2565 
  2566 * Command 'rep_datatype': instead of theorem names the command now
  2567 takes a list of terms denoting the constructors of the type to be
  2568 represented as datatype.  The characteristic theorems have to be
  2569 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2570 have disappeared in favour of existing ones:
  2571 
  2572     unit_induct                 ~> unit.induct
  2573     prod_induct                 ~> prod.induct
  2574     sum_induct                  ~> sum.induct
  2575     Suc_Suc_eq                  ~> nat.inject
  2576     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2577 
  2578 
  2579 *** HOL-Algebra ***
  2580 
  2581 * New locales for orders and lattices where the equivalence relation
  2582 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2583 locales use a record structure with field eq for the equivalence.
  2584 
  2585 * New theory of factorial domains.
  2586 
  2587 * Units_l_inv and Units_r_inv are now simp rules by default.
  2588 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2589 and/or r_inv will now also require deletion of these lemmas.
  2590 
  2591 * Renamed the following theorems, INCOMPATIBILITY:
  2592 
  2593 UpperD ~> Upper_memD
  2594 LowerD ~> Lower_memD
  2595 least_carrier ~> least_closed
  2596 greatest_carrier ~> greatest_closed
  2597 greatest_Lower_above ~> greatest_Lower_below
  2598 one_zero ~> carrier_one_zero
  2599 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2600 
  2601 
  2602 *** HOL-Nominal ***
  2603 
  2604 * Nominal datatypes can now contain type-variables.
  2605 
  2606 * Commands 'nominal_inductive' and 'equivariance' work with local
  2607 theory targets.
  2608 
  2609 * Nominal primrec can now works with local theory targets and its
  2610 specification syntax now conforms to the general format as seen in
  2611 'inductive' etc.
  2612 
  2613 * Method "perm_simp" honours the standard simplifier attributes
  2614 (no_asm), (no_asm_use) etc.
  2615 
  2616 * The new predicate #* is defined like freshness, except that on the
  2617 left hand side can be a set or list of atoms.
  2618 
  2619 * Experimental command 'nominal_inductive2' derives strong induction
  2620 principles for inductive definitions.  In contrast to
  2621 'nominal_inductive', which can only deal with a fixed number of
  2622 binders, it can deal with arbitrary expressions standing for sets of
  2623 atoms to be avoided.  The only inductive definition we have at the
  2624 moment that needs this generalisation is the typing rule for Lets in
  2625 the algorithm W:
  2626 
  2627  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2628  -----------------------------------------------------------------
  2629          Gamma |- Let x be t1 in t2 : T2
  2630 
  2631 In this rule one wants to avoid all the binders that are introduced by
  2632 "close Gamma T1".  We are looking for other examples where this
  2633 feature might be useful.  Please let us know.
  2634 
  2635 
  2636 *** HOLCF ***
  2637 
  2638 * Reimplemented the simplification procedure for proving continuity
  2639 subgoals.  The new simproc is extensible; users can declare additional
  2640 continuity introduction rules with the attribute [cont2cont].
  2641 
  2642 * The continuity simproc now uses a different introduction rule for
  2643 solving continuity subgoals on terms with lambda abstractions.  In
  2644 some rare cases the new simproc may fail to solve subgoals that the
  2645 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2646 Potential INCOMPATIBILITY.
  2647 
  2648 * Command 'fixrec': specification syntax now conforms to the general
  2649 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2650 examples.  INCOMPATIBILITY.
  2651 
  2652 
  2653 *** ZF ***
  2654 
  2655 * Proof of Zorn's Lemma for partial orders.
  2656 
  2657 
  2658 *** ML ***
  2659 
  2660 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2661 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2662 depends on multithreading, so timouts will not work before Poly/ML
  2663 5.2.1!
  2664 
  2665 * High-level support for concurrent ML programming, see
  2666 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2667 particularly convenient to organize independent functional
  2668 computations.  The concept of "synchronized variables" provides a
  2669 higher-order interface for components with shared state, avoiding the
  2670 delicate details of mutexes and condition variables.  (Requires
  2671 Poly/ML 5.2.1 or later.)
  2672 
  2673 * ML bindings produced via Isar commands are stored within the Isar
  2674 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2675 become thread-safe and work with undo as expected (concerning
  2676 top-level bindings, not side-effects on global references).
  2677 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2678 compiler at runtime; really global bindings need to be given outside a
  2679 theory.  (Requires Poly/ML 5.2 or later.)
  2680 
  2681 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2682 context.  Top-level ML bindings are stored within the proof context in
  2683 a purely sequential fashion, disregarding the nested proof structure.
  2684 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2685 proof.  (Requires Poly/ML 5.2 or later.)
  2686 
  2687 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2688 and Method.setup, as well as Isar commands 'attribute_setup' and
  2689 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2690 existing code accordingly, or use plain 'setup' together with old
  2691 Method.add_method.
  2692 
  2693 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2694 to 'a -> thm, while results are always tagged with an authentic oracle
  2695 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2696 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2697 accordingly.  Note that extra performance may be gained by producing
  2698 the cterm carefully, avoiding slow Thm.cterm_of.
  2699 
  2700 * Simplified interface for defining document antiquotations via
  2701 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2702 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2703 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2704 examples.
  2705 
  2706 * More systematic treatment of long names, abstract name bindings, and
  2707 name space operations.  Basic operations on qualified names have been
  2708 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2709 Long_Name.append.  Old type bstring has been mostly replaced by
  2710 abstract type binding (see structure Binding), which supports precise
  2711 qualification by packages and local theory targets, as well as proper
  2712 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2713 bstring values into Binding.name, or better pass through abstract
  2714 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2715 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2716 
  2717 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2718 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2719 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2720 
  2721 * Disposed old type and term read functions (Sign.read_def_typ,
  2722 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2723 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2724 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2725 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2726 resort for legacy applications.
  2727 
  2728 * Disposed old declarations, tactics, tactic combinators that refer to
  2729 the simpset or claset of an implicit theory (such as Addsimps,
  2730 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2731 embedded ML text, or local_simpset_of with a proper context passed as
  2732 explicit runtime argument.
  2733 
  2734 * Rules and tactics that read instantiations (read_instantiate,
  2735 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2736 context, which is required for parsing and type-checking.  Moreover,
  2737 the variables are specified as plain indexnames, not string encodings
  2738 thereof.  INCOMPATIBILITY.
  2739 
  2740 * Generic Toplevel.add_hook interface allows to analyze the result of
  2741 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2742 for theorem dependency output of transactions resulting in a new
  2743 theory state.
  2744 
  2745 * ML antiquotations: block-structured compilation context indicated by
  2746 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2747 
  2748   @{binding name}                         - basic name binding
  2749   @{let ?pat = term}                      - term abbreviation (HO matching)
  2750   @{note name = fact}                     - fact abbreviation
  2751   @{thm fact}                             - singleton fact (with attributes)
  2752   @{thms fact}                            - general fact (with attributes)
  2753   @{lemma prop by method}                 - singleton goal
  2754   @{lemma prop by meth1 meth2}            - singleton goal
  2755   @{lemma prop1 ... propN by method}      - general goal
  2756   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2757   @{lemma (open) ...}                     - open derivation
  2758 
  2759 
  2760 *** System ***
  2761 
  2762 * The Isabelle "emacs" tool provides a specific interface to invoke
  2763 Proof General / Emacs, with more explicit failure if that is not
  2764 installed (the old isabelle-interface script silently falls back on
  2765 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2766 installation location of the Proof General distribution.
  2767 
  2768 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2769 the Isabelle process into a JVM/Scala application.  See
  2770 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2771 process wrapper has been discontinued.)
  2772 
  2773 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2774 
  2775 * Various status messages (with exact source position information) are
  2776 emitted, if proper markup print mode is enabled.  This allows
  2777 user-interface components to provide detailed feedback on internal
  2778 prover operations.
  2779 
  2780 
  2781 
  2782 New in Isabelle2008 (June 2008)
  2783 -------------------------------
  2784 
  2785 *** General ***
  2786 
  2787 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2788 and updated, with formally checked references as hyperlinks.
  2789 
  2790 * Theory loader: use_thy (and similar operations) no longer set the
  2791 implicit ML context, which was occasionally hard to predict and in
  2792 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2793 provides a proper context already.
  2794 
  2795 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2796 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2797 'use' within a theory file will do the job.
  2798 
  2799 * Name space merge now observes canonical order, i.e. the second space
  2800 is inserted into the first one, while existing entries in the first
  2801 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2802 swap theory imports.
  2803 
  2804 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2805 INCOMPATIBILITY in identifier syntax etc.
  2806 
  2807 * Outer syntax: string tokens no longer admit escaped white space,
  2808 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2809 white space without escapes.
  2810 
  2811 * Outer syntax: string tokens may contain arbitrary character codes
  2812 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2813 "foo_bar".
  2814 
  2815 
  2816 *** Pure ***
  2817 
  2818 * Context-dependent token translations.  Default setup reverts locally
  2819 fixed variables, and adds hilite markup for undeclared frees.
  2820 
  2821 * Unused theorems can be found using the new command 'unused_thms'.
  2822 There are three ways of invoking it:
  2823 
  2824 (1) unused_thms
  2825      Only finds unused theorems in the current theory.
  2826 
  2827 (2) unused_thms thy_1 ... thy_n -
  2828      Finds unused theorems in the current theory and all of its ancestors,
  2829      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2830 
  2831 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2832      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2833      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2834      their ancestors.
  2835 
  2836 In order to increase the readability of the list produced by
  2837 unused_thms, theorems that have been created by a particular instance
  2838 of a theory command such as 'inductive' or 'function' are considered
  2839 to belong to the same "group", meaning that if at least one theorem in
  2840 this group is used, the other theorems in the same group are no longer
  2841 reported as unused.  Moreover, if all theorems in the group are
  2842 unused, only one theorem in the group is displayed.
  2843 
  2844 Note that proof objects have to be switched on in order for
  2845 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2846 usually the case when using Proof General with the default settings).
  2847 
  2848 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2849 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2850 duplicate fact bindings, or even accidental fact duplications.  Note
  2851 that tools may maintain dynamically scoped facts systematically, using
  2852 PureThy.add_thms_dynamic.
  2853 
  2854 * Command 'hide' now allows to hide from "fact" name space as well.
  2855 
  2856 * Eliminated destructive theorem database, simpset, claset, and
  2857 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2858 update of theories within ML code.
  2859 
  2860 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2861 INCOMPATIBILITY, object-logics depending on former Pure require
  2862 additional setup PureThy.old_appl_syntax_setup; object-logics
  2863 depending on former CPure need to refer to Pure.
  2864 
  2865 * Commands 'use' and 'ML' are now purely functional, operating on
  2866 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2867 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2868 INCOMPATIBILITY.
  2869 
  2870 * Command 'setup': discontinued implicit version with ML reference.
  2871 
  2872 * Instantiation target allows for simultaneous specification of class
  2873 instance operations together with an instantiation proof.
  2874 Type-checking phase allows to refer to class operations uniformly.
  2875 See src/HOL/Complex/Complex.thy for an Isar example and
  2876 src/HOL/Library/Eval.thy for an ML example.
  2877 
  2878 * Indexing of literal facts: be more serious about including only
  2879 facts from the visible specification/proof context, but not the
  2880 background context (locale etc.).  Affects `prop` notation and method
  2881 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2882 situations.
  2883 
  2884 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2885 "(open)" option, which used to expose internal bound variables to the
  2886 proof text.
  2887 
  2888 * Isar statements: removed obsolete case "rule_context".
  2889 INCOMPATIBILITY, better use explicit fixes/assumes.
  2890 
  2891 * Locale proofs: default proof step now includes 'unfold_locales';
  2892 hence 'proof' without argument may be used to unfold locale
  2893 predicates.
  2894 
  2895 
  2896 *** Document preparation ***
  2897 
  2898 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2899 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2900 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2901 spot); renamed link color from "darkblue" to "linkcolor" (default
  2902 value unchanged, can be redefined via \definecolor); no longer sets
  2903 "a4paper" option (unnecessary or even intrusive).
  2904 
  2905 * Antiquotation @{lemma A method} proves proposition A by the given
  2906 method (either a method name or a method name plus (optional) method
  2907 arguments in parentheses) and prints A just like @{prop A}.
  2908 
  2909 
  2910 *** HOL ***
  2911 
  2912 * New primrec package.  Specification syntax conforms in style to
  2913 definition/function/....  No separate induction rule is provided.  The
  2914 "primrec" command distinguishes old-style and new-style specifications
  2915 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2916 When adjusting theories, beware: constants stemming from new-style
  2917 primrec specifications have authentic syntax.
  2918 
  2919 * Metis prover is now an order of magnitude faster, and also works
  2920 with multithreading.
  2921 
  2922 * Metis: the maximum number of clauses that can be produced from a
  2923 theorem is now given by the attribute max_clauses.  Theorems that
  2924 exceed this number are ignored, with a warning printed.
  2925 
  2926 * Sledgehammer no longer produces structured proofs by default. To
  2927 enable, declare [[sledgehammer_full = true]].  Attributes
  2928 reconstruction_modulus, reconstruction_sorts renamed
  2929 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2930 
  2931 * Method "induct_scheme" derives user-specified induction rules
  2932 from well-founded induction and completeness of patterns. This factors
  2933 out some operations that are done internally by the function package
  2934 and makes them available separately.  See
  2935 src/HOL/ex/Induction_Scheme.thy for examples.
  2936 
  2937 * More flexible generation of measure functions for termination
  2938 proofs: Measure functions can be declared by proving a rule of the
  2939 form "is_measure f" and giving it the [measure_function] attribute.
  2940 The "is_measure" predicate is logically meaningless (always true), and
  2941 just guides the heuristic.  To find suitable measure functions, the
  2942 termination prover sets up the goal "is_measure ?f" of the appropriate
  2943 type and generates all solutions by prolog-style backwards proof using
  2944 the declared rules.
  2945 
  2946 This setup also deals with rules like 
  2947 
  2948   "is_measure f ==> is_measure (list_size f)"
  2949 
  2950 which accommodates nested datatypes that recurse through lists.
  2951 Similar rules are predeclared for products and option types.
  2952 
  2953 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2954 
  2955   INCOMPATIBILITIES:
  2956 
  2957   - Definitions of overloaded constants on sets have to be replaced by
  2958     definitions on => and bool.
  2959 
  2960   - Some definitions of overloaded operators on sets can now be proved
  2961     using the definitions of the operators on => and bool.  Therefore,
  2962     the following theorems have been renamed:
  2963 
  2964       subset_def   -> subset_eq
  2965       psubset_def  -> psubset_eq
  2966       set_diff_def -> set_diff_eq
  2967       Compl_def    -> Compl_eq
  2968       Sup_set_def  -> Sup_set_eq
  2969       Inf_set_def  -> Inf_set_eq
  2970       sup_set_def  -> sup_set_eq
  2971       inf_set_def  -> inf_set_eq
  2972 
  2973   - Due to the incompleteness of the HO unification algorithm, some
  2974     rules such as subst may require manual instantiation, if some of
  2975     the unknowns in the rule is a set.
  2976 
  2977   - Higher order unification and forward proofs:
  2978     The proof pattern
  2979 
  2980       have "P (S::'a set)" <...>
  2981       then have "EX S. P S" ..
  2982 
  2983     no longer works (due to the incompleteness of the HO unification
  2984     algorithm) and must be replaced by the pattern
  2985 
  2986       have "EX S. P S"
  2987       proof
  2988         show "P S" <...>
  2989       qed
  2990 
  2991   - Calculational reasoning with subst (or similar rules):
  2992     The proof pattern
  2993 
  2994       have "P (S::'a set)" <...>
  2995       also have "S = T" <...>
  2996       finally have "P T" .
  2997 
  2998     no longer works (for similar reasons as the previous example) and
  2999     must be replaced by something like
  3000 
  3001       have "P (S::'a set)" <...>
  3002       moreover have "S = T" <...>
  3003       ultimately have "P T" by simp
  3004 
  3005   - Tactics or packages written in ML code:
  3006     Code performing pattern matching on types via
  3007 
  3008       Type ("set", [T]) => ...
  3009 
  3010     must be rewritten. Moreover, functions like strip_type or
  3011     binder_types no longer return the right value when applied to a
  3012     type of the form
  3013 
  3014       T1 => ... => Tn => U => bool
  3015 
  3016     rather than
  3017 
  3018       T1 => ... => Tn => U set
  3019 
  3020 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3021 Wellfounded_Relations to theory Wellfounded.
  3022 
  3023 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3024 
  3025 * Class finite no longer treats UNIV as class parameter.  Use class
  3026 enum from theory Library/Enum instead to achieve a similar effect.
  3027 INCOMPATIBILITY.
  3028 
  3029 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3030 and "Cons".  INCOMPATIBILITY.
  3031 
  3032 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3033 Potential INCOMPATIBILITY.
  3034 
  3035 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3036 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3037 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3038 
  3039 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3040 the same name in theory Orderings:
  3041 
  3042   less_trans
  3043   less_linear
  3044   le_imp_less_or_eq
  3045   le_less_trans
  3046   less_le_trans
  3047   less_not_sym
  3048   less_asym
  3049 
  3050 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3051 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3052 and different variable names.
  3053 
  3054 * Library/Option_ord.thy: Canonical order on option type.
  3055 
  3056 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3057 finite maps.
  3058 
  3059 * Library/Countable.thy: Type class for countable types.
  3060 
  3061 * Theory Int: The representation of numerals has changed.  The infix
  3062 operator BIT and the bit datatype with constructors B0 and B1 have
  3063 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3064 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3065 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3066 accordingly.
  3067 
  3068 * Theory Nat: definition of <= and < on natural numbers no longer
  3069 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3070 le_def and less_def have disappeared.  Consider lemmas not_less
  3071 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3072 
  3073 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3074 (whose purpose mainly is for various fold_set functionals) have been
  3075 abandoned in favor of the existing algebraic classes
  3076 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3077 lower_semilattice (resp. upper_semilattice) and linorder.
  3078 INCOMPATIBILITY.
  3079 
  3080 * Theory Transitive_Closure: induct and cases rules now declare proper
  3081 case_names ("base" and "step").  INCOMPATIBILITY.
  3082 
  3083 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3084 lattices.  The form set-specific version is available as
  3085 Inductive.lfp_ordinal_induct_set.
  3086 
  3087 * Renamed theorems "power.simps" to "power_int.simps".
  3088 INCOMPATIBILITY.
  3089 
  3090 * Class semiring_div provides basic abstract properties of semirings
  3091 with division and modulo operations.  Subsumes former class dvd_mod.
  3092 
  3093 * Merged theories IntDef, Numeral and IntArith into unified theory
  3094 Int.  INCOMPATIBILITY.
  3095 
  3096 * Theory Library/Code_Index: type "index" now represents natural
  3097 numbers rather than integers.  INCOMPATIBILITY.
  3098 
  3099 * New class "uminus" with operation "uminus" (split of from class
  3100 "minus" which now only has operation "minus", binary).
  3101 INCOMPATIBILITY.
  3102 
  3103 * Constants "card", "internal_split", "option_map" now with authentic
  3104 syntax.  INCOMPATIBILITY.
  3105 
  3106 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3107 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3108 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3109 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3110 Sup_set_def, le_def, less_def, option_map_def now with object
  3111 equality.  INCOMPATIBILITY.
  3112 
  3113 * Records. Removed K_record, and replaced it by pure lambda term
  3114 %x. c. The simplifier setup is now more robust against eta expansion.
  3115 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3116 
  3117 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3118 
  3119 * Library/ListVector: new theory of arithmetic vector operations.
  3120 
  3121 * Library/Order_Relation: new theory of various orderings as sets of
  3122 pairs.  Defines preorders, partial orders, linear orders and
  3123 well-orders on sets and on types.
  3124 
  3125 
  3126 *** ZF ***
  3127 
  3128 * Renamed some theories to allow to loading both ZF and HOL in the
  3129 same session:
  3130 
  3131   Datatype  -> Datatype_ZF
  3132   Inductive -> Inductive_ZF
  3133   Int       -> Int_ZF
  3134   IntDiv    -> IntDiv_ZF
  3135   Nat       -> Nat_ZF
  3136   List      -> List_ZF
  3137   Main      -> Main_ZF
  3138 
  3139 INCOMPATIBILITY: ZF theories that import individual theories below
  3140 Main might need to be adapted.  Regular theory Main is still
  3141 available, as trivial extension of Main_ZF.
  3142 
  3143 
  3144 *** ML ***
  3145 
  3146 * ML within Isar: antiquotation @{const name} or @{const
  3147 name(typargs)} produces statically-checked Const term.
  3148 
  3149 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3150 (of the same name).  Removed obsolete print command.
  3151 
  3152 * Removed obsolete "use_legacy_bindings" function.
  3153 
  3154 * The ``print mode'' is now a thread-local value derived from a global
  3155 template (the former print_mode reference), thus access becomes
  3156 non-critical.  The global print_mode reference is for session
  3157 management only; user-code should use print_mode_value,
  3158 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3159 
  3160 * Functions system/system_out provide a robust way to invoke external
  3161 shell commands, with propagation of interrupts (requires Poly/ML
  3162 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3163 
  3164 
  3165 *** System ***
  3166 
  3167 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3168 in accordance with Proof General 3.7, which prefers GNU emacs.
  3169 
  3170 * isatool tty runs Isabelle process with plain tty interaction;
  3171 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3172 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3173 
  3174 * isatool browser now works with Cygwin as well, using general
  3175 "javapath" function defined in Isabelle process environment.
  3176 
  3177 * YXML notation provides a simple and efficient alternative to
  3178 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3179 isatool yxml as described in the Isabelle system manual.
  3180 
  3181 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3182 provides general wrapper for managing an Isabelle process in a robust
  3183 fashion, with ``cooked'' output from stdin/stderr.
  3184 
  3185 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3186 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3187 
  3188 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3189 way of changing the user's settings is via
  3190 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3191 script.
  3192 
  3193 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3194 cores of the underlying machine, which is a good starting point for
  3195 optimal performance tuning.  The corresponding usedir option -M allows
  3196 "max" as an alias for "0".  WARNING: does not work on certain versions
  3197 of Mac OS (with Poly/ML 5.1).
  3198 
  3199 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3200 adverse effect of Isabelle flooding interactive front-ends (notably
  3201 ProofGeneral / XEmacs).
  3202 
  3203 
  3204 
  3205 New in Isabelle2007 (November 2007)
  3206 -----------------------------------
  3207 
  3208 *** General ***
  3209 
  3210 * More uniform information about legacy features, notably a
  3211 warning/error of "Legacy feature: ...", depending on the state of the
  3212 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3213 legacy features will disappear eventually.
  3214 
  3215 * Theory syntax: the header format ``theory A = B + C:'' has been
  3216 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3217 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3218 
  3219 * Theory syntax: the old non-Isar theory file format has been
  3220 discontinued altogether.  Note that ML proof scripts may still be used
  3221 with Isar theories; migration is usually quite simple with the ML
  3222 function use_legacy_bindings.  INCOMPATIBILITY.
  3223 
  3224 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3225 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3226 quotes.
  3227 
  3228 * Theory loader: be more serious about observing the static theory
  3229 header specifications (including optional directories), but not the
  3230 accidental file locations of previously successful loads.  The strict
  3231 update policy of former update_thy is now already performed by
  3232 use_thy, so the former has been removed; use_thys updates several
  3233 theories simultaneously, just as 'imports' within a theory header
  3234 specification, but without merging the results.  Potential
  3235 INCOMPATIBILITY: may need to refine theory headers and commands
  3236 ROOT.ML which depend on load order.
  3237 
  3238 * Theory loader: optional support for content-based file
  3239 identification, instead of the traditional scheme of full physical
  3240 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3241 (cf. the system manual).  The new scheme allows to work with
  3242 non-finished theories in persistent session images, such that source
  3243 files may be moved later on without requiring reloads.
  3244 
  3245 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3246 file (with the same base name as the theory) are considered a legacy
  3247 feature, which will disappear eventually. Even now, the theory loader
  3248 no longer maintains dependencies on such files.
  3249 
  3250 * Syntax: the scope for resolving ambiguities via type-inference is
  3251 now limited to individual terms, instead of whole simultaneous
  3252 specifications as before. This greatly reduces the complexity of the
  3253 syntax module and improves flexibility by separating parsing and
  3254 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3255 'fixes' etc.) are required in rare situations.
  3256 
  3257 * Syntax: constants introduced by new-style packages ('definition',
  3258 'abbreviation' etc.) are passed through the syntax module in
  3259 ``authentic mode''. This means that associated mixfix annotations
  3260 really stick to such constants, independently of potential name space
  3261 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3262 trees are represented slightly differently, may need to adapt syntax
  3263 translations accordingly. Use CONST marker in 'translations' and
  3264 @{const_syntax} antiquotation in 'parse_translation' etc.
  3265 
  3266 * Legacy goal package: reduced interface to the bare minimum required
  3267 to keep existing proof scripts running.  Most other user-level
  3268 functions are now part of the OldGoals structure, which is *not* open
  3269 by default (consider isatool expandshort before open OldGoals).
  3270 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3271 these tend to cause confusion about the actual goal (!) context being
  3272 used here, which is not necessarily the same as the_context().
  3273 
  3274 * Command 'find_theorems': supports "*" wild-card in "name:"
  3275 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3276 support a specific search form (see ProofGeneral/CHANGES).
  3277 
  3278 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3279 by default, which means that "prems" (and also "fixed variables") are
  3280 suppressed from proof state output.  Note that the ProofGeneral
  3281 settings mechanism allows to change and save options persistently, but
  3282 older versions of Isabelle will fail to start up if a negative prems
  3283 limit is imposed.
  3284 
  3285 * Local theory targets may be specified by non-nested blocks of
  3286 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3287 contain definitions, theorems etc., including any derived mechanism
  3288 that has been implemented on top of these primitives.  This concept
  3289 generalizes the existing ``theorem (in ...)'' towards more versatility
  3290 and scalability.
  3291 
  3292 * Proof General interface: proper undo of final 'end' command;
  3293 discontinued Isabelle/classic mode (ML proof scripts).
  3294 
  3295 
  3296 *** Document preparation ***
  3297 
  3298 * Added antiquotation @{theory name} which prints the given name,
  3299 after checking that it refers to a valid ancestor theory in the
  3300 current context.
  3301 
  3302 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3303 check the given source text as ML type/structure, printing verbatim.
  3304 
  3305 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3306 "c args == rhs" given in the current context.  (Any number of
  3307 arguments may be given on the LHS.)
  3308 
  3309 
  3310 *** Pure ***
  3311 
  3312 * The 'class' package offers a combination of axclass and locale to
  3313 achieve Haskell-like type classes in Isabelle.  Definitions and
  3314 theorems within a class context produce both relative results (with
  3315 implicit parameters according to the locale context), and polymorphic
  3316 constants with qualified polymorphism (according to the class
  3317 context).  Within the body context of a 'class' target, a separate
  3318 syntax layer ("user space type system") takes care of converting
  3319 between global polymorphic consts and internal locale representation.
  3320 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3321 "isatool doc classes" provides a tutorial.
  3322 
  3323 * Generic code generator framework allows to generate executable
  3324 code for ML and Haskell (including Isabelle classes).  A short usage
  3325 sketch:
  3326 
  3327     internal compilation:
  3328         export_code <list of constants (term syntax)> in SML
  3329     writing SML code to a file:
  3330         export_code <list of constants (term syntax)> in SML <filename>
  3331     writing OCaml code to a file:
  3332         export_code <list of constants (term syntax)> in OCaml <filename>
  3333     writing Haskell code to a bunch of files:
  3334         export_code <list of constants (term syntax)> in Haskell <filename>
  3335 
  3336     evaluating closed propositions to True/False using code generation:
  3337         method ``eval''
  3338 
  3339 Reasonable default setup of framework in HOL.
  3340 
  3341 Theorem attributs for selecting and transforming function equations theorems:
  3342 
  3343     [code fun]:        select a theorem as function equation for a specific constant
  3344     [code fun del]:    deselect a theorem as function equation for a specific constant
  3345     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3346     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3347 
  3348 User-defined serializations (target in {SML, OCaml, Haskell}):
  3349 
  3350     code_const <and-list of constants (term syntax)>
  3351       {(target) <and-list of const target syntax>}+
  3352 
  3353     code_type <and-list of type constructors>
  3354       {(target) <and-list of type target syntax>}+
  3355 
  3356     code_instance <and-list of instances>
  3357       {(target)}+
  3358         where instance ::= <type constructor> :: <class>
  3359 
  3360     code_class <and_list of classes>
  3361       {(target) <and-list of class target syntax>}+
  3362         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3363 
  3364 code_instance and code_class only are effective to target Haskell.
  3365 
  3366 For example usage see src/HOL/ex/Codegenerator.thy and
  3367 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3368 generation from Isabelle/HOL theories is available via "isatool doc
  3369 codegen".
  3370 
  3371 * Code generator: consts in 'consts_code' Isar commands are now
  3372 referred to by usual term syntax (including optional type
  3373 annotations).
  3374 
  3375 * Command 'no_translations' removes translation rules from theory
  3376 syntax.
  3377 
  3378 * Overloaded definitions are now actually checked for acyclic
  3379 dependencies.  The overloading scheme is slightly more general than
  3380 that of Haskell98, although Isabelle does not demand an exact
  3381 correspondence to type class and instance declarations.
  3382 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3383 exotic versions of overloading -- at the discretion of the user!
  3384 
  3385 Polymorphic constants are represented via type arguments, i.e. the
  3386 instantiation that matches an instance against the most general
  3387 declaration given in the signature.  For example, with the declaration
  3388 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3389 as c(nat).  Overloading is essentially simultaneous structural
  3390 recursion over such type arguments.  Incomplete specification patterns
  3391 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3392 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3393 Command 'print_theory' outputs the normalized system of recursive
  3394 equations, see section "definitions".
  3395 
  3396 * Configuration options are maintained within the theory or proof
  3397 context (with name and type bool/int/string), providing a very simple
  3398 interface to a poor-man's version of general context data.  Tools may
  3399 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3400 these values using Config.get etc.  Users may change options via an
  3401 associated attribute of the same name.  This form of context
  3402 declaration works particularly well with commands 'declare' or
  3403 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3404 very easy to avoid global references, which would not observe Isar
  3405 toplevel undo/redo and fail to work with multithreading.
  3406 
  3407 Various global ML references of Pure and HOL have been turned into
  3408 configuration options:
  3409 
  3410   Unify.search_bound		unify_search_bound
  3411   Unify.trace_bound		unify_trace_bound
  3412   Unify.trace_simp		unify_trace_simp
  3413   Unify.trace_types		unify_trace_types
  3414   Simplifier.simp_depth_limit	simp_depth_limit
  3415   Blast.depth_limit		blast_depth_limit
  3416   DatatypeProp.dtK		datatype_distinctness_limit
  3417   fast_arith_neq_limit  	fast_arith_neq_limit
  3418   fast_arith_split_limit	fast_arith_split_limit
  3419 
  3420 * Named collections of theorems may be easily installed as context
  3421 data using the functor NamedThmsFun (see also
  3422 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3423 attributes; there is also a toplevel print command.  This facility is
  3424 just a common case of general context data, which is the preferred way
  3425 for anything more complex than just a list of facts in canonical
  3426 order.
  3427 
  3428 * Isar: command 'declaration' augments a local theory by generic
  3429 declaration functions written in ML.  This enables arbitrary content
  3430 being added to the context, depending on a morphism that tells the
  3431 difference of the original declaration context wrt. the application
  3432 context encountered later on.
  3433 
  3434 * Isar: proper interfaces for simplification procedures.  Command
  3435 'simproc_setup' declares named simprocs (with match patterns, and body
  3436 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3437 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3438 
  3439 * Isar: an extra pair of brackets around attribute declarations
  3440 abbreviates a theorem reference involving an internal dummy fact,
  3441 which will be ignored later --- only the effect of the attribute on
  3442 the background context will persist.  This form of in-place
  3443 declarations is particularly useful with commands like 'declare' and
  3444 'using', for example ``have A using [[simproc a]] by simp''.
  3445 
  3446 * Isar: method "assumption" (and implicit closing of subproofs) now
  3447 takes simple non-atomic goal assumptions into account: after applying
  3448 an assumption as a rule the resulting subgoals are solved by atomic
  3449 assumption steps.  This is particularly useful to finish 'obtain'
  3450 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3451 without referring to the original premise "!!x. P x ==> thesis" in the
  3452 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3453 more permissive.
  3454 
  3455 * Isar: implicit use of prems from the Isar proof context is
  3456 considered a legacy feature.  Common applications like ``have A .''
  3457 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3458 referencing facts explicitly here improves readability and
  3459 maintainability of proof texts.
  3460 
  3461 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3462 the obtained context from the course of reasoning!  For example:
  3463 
  3464   assume "EX x y. A x & B y"   -- "any previous fact"
  3465   then guess x and y by clarify
  3466 
  3467 This technique is potentially adventurous, depending on the facts and
  3468 proof tools being involved here.
  3469 
  3470 * Isar: known facts from the proof context may be specified as literal
  3471 propositions, using ASCII back-quote syntax.  This works wherever
  3472 named facts used to be allowed so far, in proof commands, proof
  3473 methods, attributes etc.  Literal facts are retrieved from the context
  3474 according to unification of type and term parameters.  For example,
  3475 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3476 theorems in the current context, then these are valid literal facts:
  3477 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3478 
  3479 There is also a proof method "fact" which does the same composition
  3480 for explicit goal states, e.g. the following proof texts coincide with
  3481 certain special cases of literal facts:
  3482 
  3483   have "A" by fact                 ==  note `A`
  3484   have "A ==> B" by fact           ==  note `A ==> B`
  3485   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3486   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3487 
  3488 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3489 outer syntax.  Thus symbolic identifiers may be used without
  3490 additional white space in declarations like this: ``assume *: A''.
  3491 
  3492 * Isar: 'print_facts' prints all local facts of the current context,
  3493 both named and unnamed ones.
  3494 
  3495 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3496 
  3497   def x == "t" and y == "u"
  3498 
  3499 * Isar: added command 'unfolding', which is structurally similar to
  3500 'using', but affects both the goal state and facts by unfolding given
  3501 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3502 'unfolded' attribute may be replaced by first-class proof text.
  3503 
  3504 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3505 and command 'unfolding' now all support object-level equalities
  3506 (potentially conditional).  The underlying notion of rewrite rule is
  3507 analogous to the 'rule_format' attribute, but *not* that of the
  3508 Simplifier (which is usually more generous).
  3509 
  3510 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3511 premises of a theorem by n. Useful in conjunction with drule.
  3512 
  3513 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3514 method expression within a sandbox consisting of the first N
  3515 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3516 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3517 simplifies all new goals that emerge from applying rule foo to the
  3518 originally first one.
  3519 
  3520 * Isar: schematic goals are no longer restricted to higher-order
  3521 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3522 expected.
  3523 
  3524 * Isar: the conclusion of a long theorem statement is now either
  3525 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3526 (essentially a disjunction of cases with local parameters and
  3527 assumptions).  The latter allows to express general elimination rules
  3528 adequately; in this notation common elimination rules look like this:
  3529 
  3530   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3531     assumes "EX x. P x"
  3532     obtains x where "P x"
  3533 
  3534   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3535     assumes "A & B"
  3536     obtains A and B
  3537 
  3538   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3539     assumes "A | B"
  3540     obtains
  3541       A
  3542     | B
  3543 
  3544 The subsequent classical rules even refer to the formal "thesis"
  3545 explicitly:
  3546 
  3547   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3548     obtains "~ thesis"
  3549 
  3550   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3551     obtains "thesis ==> something"
  3552 
  3553 The actual proof of an 'obtains' statement is analogous to that of the
  3554 Isar proof element 'obtain', only that there may be several cases.
  3555 Optional case names may be specified in parentheses; these will be
  3556 available both in the present proof and as annotations in the
  3557 resulting rule, for later use with the 'cases' method (cf. attribute
  3558 case_names).
  3559 
  3560 * Isar: the assumptions of a long theorem statement are available as
  3561 "assms" fact in the proof context.  This is more appropriate than the
  3562 (historical) "prems", which refers to all assumptions of the current
  3563 context, including those from the target locale, proof body etc.
  3564 
  3565 * Isar: 'print_statement' prints theorems from the current theory or
  3566 proof context in long statement form, according to the syntax of a
  3567 top-level lemma.
  3568 
  3569 * Isar: 'obtain' takes an optional case name for the local context
  3570 introduction rule (default "that").
  3571 
  3572 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3573 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3574 to occur.
  3575 
  3576 * Pure: syntax "CONST name" produces a fully internalized constant
  3577 according to the current context.  This is particularly useful for
  3578 syntax translations that should refer to internal constant
  3579 representations independently of name spaces.
  3580 
  3581 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3582 instead of "FOO ". This allows multiple binder declarations to coexist
  3583 in the same context.  INCOMPATIBILITY.
  3584 
  3585 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3586 primitive that also works in a locale context (both for constants and
  3587 fixed variables). Type declaration and internal syntactic representation
  3588 of given constants retrieved from the context. Likewise, the
  3589 'no_notation' command allows to remove given syntax annotations from the
  3590 current context.
  3591 
  3592 * Isar/locales: new derived specification elements 'axiomatization',
  3593 'definition', 'abbreviation', which support type-inference, admit
  3594 object-level specifications (equality, equivalence).  See also the
  3595 isar-ref manual.  Examples:
  3596 
  3597   axiomatization
  3598     eq  (infix "===" 50) where
  3599     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3600 
  3601   definition "f x y = x + y + 1"
  3602   definition g where "g x = f x x"
  3603 
  3604   abbreviation
  3605     neq  (infix "=!=" 50) where
  3606     "x =!= y == ~ (x === y)"
  3607 
  3608 These specifications may be also used in a locale context.  Then the
  3609 constants being introduced depend on certain fixed parameters, and the
  3610 constant name is qualified by the locale base name.  An internal
  3611 abbreviation takes care for convenient input and output, making the
  3612 parameters implicit and using the original short name.  See also
  3613 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3614 entities from a monomorphic theory.
  3615 
  3616 Presently, abbreviations are only available 'in' a target locale, but
  3617 not inherited by general import expressions.  Also note that
  3618 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3619 'translations' in common applications.  The "no_abbrevs" print mode
  3620 prevents folding of abbreviations in term output.
  3621 
  3622 Concrete syntax is attached to specified constants in internal form,
  3623 independently of name spaces.  The parse tree representation is
  3624 slightly different -- use 'notation' instead of raw 'syntax', and
  3625 'translations' with explicit "CONST" markup to accommodate this.
  3626 
  3627 * Pure/Isar: unified syntax for new-style specification mechanisms
  3628 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3629 full type inference and dummy patterns ("_").  For example:
  3630 
  3631   definition "K x _ = x"
  3632 
  3633   inductive conj for A B
  3634   where "A ==> B ==> conj A B"
  3635 
  3636 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3637 the current context.  Print mode "no_abbrevs" prevents inversion of
  3638 abbreviations on output.
  3639 
  3640 * Isar/locales: improved parameter handling: use of locales "var" and
  3641 "struct" no longer necessary; - parameter renamings are no longer
  3642 required to be injective.  For example, this allows to define
  3643 endomorphisms as locale endom = homom mult mult h.
  3644 
  3645 * Isar/locales: changed the way locales with predicates are defined.
  3646 Instead of accumulating the specification, the imported expression is
  3647 now an interpretation.  INCOMPATIBILITY: different normal form of
  3648 locale expressions.  In particular, in interpretations of locales with
  3649 predicates, goals repesenting already interpreted fragments are not
  3650 removed automatically.  Use methods `intro_locales' and
  3651 `unfold_locales'; see below.
  3652 
  3653 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3654 provide backward reasoning on locales predicates.  The methods are
  3655 aware of interpretations and discharge corresponding goals.
  3656 `intro_locales' is less aggressive then `unfold_locales' and does not
  3657 unfold predicates to assumptions.
  3658 
  3659 * Isar/locales: the order in which locale fragments are accumulated
  3660 has changed.  This enables to override declarations from fragments due
  3661 to interpretations -- for example, unwanted simp rules.
  3662 
  3663 * Isar/locales: interpretation in theories and proof contexts has been
  3664 extended.  One may now specify (and prove) equations, which are
  3665 unfolded in interpreted theorems.  This is useful for replacing
  3666 defined concepts (constants depending on locale parameters) by
  3667 concepts already existing in the target context.  Example:
  3668 
  3669   interpretation partial_order ["op <= :: [int, int] => bool"]
  3670     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3671 
  3672 Typically, the constant `partial_order.less' is created by a
  3673 definition specification element in the context of locale
  3674 partial_order.
  3675 
  3676 * Method "induct": improved internal context management to support
  3677 local fixes and defines on-the-fly. Thus explicit meta-level
  3678 connectives !!  and ==> are rarely required anymore in inductive goals
  3679 (using object-logic connectives for this purpose has been long
  3680 obsolete anyway). Common proof patterns are explained in
  3681 src/HOL/Induct/Common_Patterns.thy, see also
  3682 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3683 examples.
  3684 
  3685 * Method "induct": improved handling of simultaneous goals. Instead of
  3686 introducing object-level conjunction, the statement is now split into
  3687 several conclusions, while the corresponding symbolic cases are nested
  3688 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3689 see src/HOL/Induct/Common_Patterns.thy, for example.
  3690 
  3691 * Method "induct": mutual induction rules are now specified as a list
  3692 of rule sharing the same induction cases. HOL packages usually provide
  3693 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3694 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3695 mutual induction rules differently, i.e. like this:
  3696 
  3697   (induct rule: foo_bar.inducts)
  3698   (induct set: foo bar)
  3699   (induct pred: foo bar)
  3700   (induct type: foo bar)
  3701 
  3702 The ML function ProjectRule.projections turns old-style rules into the
  3703 new format.
  3704 
  3705 * Method "coinduct": dual of induction, see
  3706 src/HOL/Library/Coinductive_List.thy for various examples.
  3707 
  3708 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3709 considered a legacy feature.
  3710 
  3711 * Attribute "symmetric" produces result with standardized schematic
  3712 variables (index 0).  Potential INCOMPATIBILITY.
  3713 
  3714 * Simplifier: by default the simplifier trace only shows top level
  3715 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3716 default. Thus there is less danger of being flooded by the trace. The
  3717 trace indicates where parts have been suppressed.
  3718   
  3719 * Provers/classical: removed obsolete classical version of elim_format
  3720 attribute; classical elim/dest rules are now treated uniformly when
  3721 manipulating the claset.
  3722 
  3723 * Provers/classical: stricter checks to ensure that supplied intro,
  3724 dest and elim rules are well-formed; dest and elim rules must have at
  3725 least one premise.
  3726 
  3727 * Provers/classical: attributes dest/elim/intro take an optional
  3728 weight argument for the rule (just as the Pure versions).  Weights are
  3729 ignored by automated tools, but determine the search order of single
  3730 rule steps.
  3731 
  3732 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3733 where the body does not mention the bound variable.  Note that dummy
  3734 patterns implicitly depend on their context of bounds, which makes
  3735 "{_. _}" match any set comprehension as expected.  Potential
  3736 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3737 constant "_idtdummy" in the binding position.
  3738 
  3739 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3740 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3741 for example "A -> B" => "Pi A (%_. B)".
  3742 
  3743 * Pure: 'class_deps' command visualizes the subclass relation, using
  3744 the graph browser tool.
  3745 
  3746 * Pure: 'print_theory' now suppresses certain internal declarations by
  3747 default; use '!' option for full details.
  3748 
  3749 
  3750 *** HOL ***
  3751 
  3752 * Method "metis" proves goals by applying the Metis general-purpose
  3753 resolution prover (see also http://gilith.com/software/metis/).
  3754 Examples are in the directory MetisExamples.  WARNING: the
  3755 Isabelle/HOL-Metis integration does not yet work properly with
  3756 multi-threading.
  3757   
  3758 * Command 'sledgehammer' invokes external automatic theorem provers as
  3759 background processes.  It generates calls to the "metis" method if
  3760 successful. These can be pasted into the proof.  Users do not have to
  3761 wait for the automatic provers to return.  WARNING: does not really
  3762 work with multi-threading.
  3763 
  3764 * New "auto_quickcheck" feature tests outermost goal statements for
  3765 potential counter-examples.  Controlled by ML references
  3766 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3767 5000 milliseconds).  Fails silently if statements is outside of
  3768 executable fragment, or any other codgenerator problem occurs.
  3769 
  3770 * New constant "undefined" with axiom "undefined x = undefined".
  3771 
  3772 * Added class "HOL.eq", allowing for code generation with polymorphic
  3773 equality.
  3774 
  3775 * Some renaming of class constants due to canonical name prefixing in
  3776 the new 'class' package:
  3777 
  3778     HOL.abs ~> HOL.abs_class.abs
  3779     HOL.divide ~> HOL.divide_class.divide
  3780     0 ~> HOL.zero_class.zero
  3781     1 ~> HOL.one_class.one
  3782     op + ~> HOL.plus_class.plus
  3783     op - ~> HOL.minus_class.minus
  3784     uminus ~> HOL.minus_class.uminus
  3785     op * ~> HOL.times_class.times
  3786     op < ~> HOL.ord_class.less
  3787     op <= > HOL.ord_class.less_eq
  3788     Nat.power ~> Power.power_class.power
  3789     Nat.size ~> Nat.size_class.size
  3790     Numeral.number_of ~> Numeral.number_class.number_of
  3791     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3792     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3793     Orderings.min ~> Orderings.ord_class.min
  3794     Orderings.max ~> Orderings.ord_class.max
  3795     Divides.op div ~> Divides.div_class.div
  3796     Divides.op mod ~> Divides.div_class.mod
  3797     Divides.op dvd ~> Divides.div_class.dvd
  3798 
  3799 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3800 
  3801 a) User-defined constants using any of the names "plus", "minus",
  3802 "times", "less" or "less_eq". The standard syntax translations for
  3803 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3804 names.
  3805 
  3806 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3807 INCOMPATIBILITY: use more specific names.
  3808 
  3809 c) Permutative equations (e.g. "a + b = b + a")
  3810 Since the change of names also changes the order of terms, permutative
  3811 rewrite rules may get applied in a different order. Experience shows
  3812 that this is rarely the case (only two adaptions in the whole Isabelle
  3813 distribution).  INCOMPATIBILITY: rewrite proofs
  3814 
  3815 d) ML code directly refering to constant names
  3816 This in general only affects hand-written proof tactics, simprocs and
  3817 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3818 Consider using @{const_name} antiquotation.
  3819 
  3820 * New class "default" with associated constant "default".
  3821 
  3822 * Function "sgn" is now overloaded and available on int, real, complex
  3823 (and other numeric types), using class "sgn".  Two possible defs of
  3824 sgn are given as equational assumptions in the classes sgn_if and
  3825 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3826 INCOMPATIBILITY.
  3827 
  3828 * Locale "partial_order" now unified with class "order" (cf. theory
  3829 Orderings), added parameter "less".  INCOMPATIBILITY.
  3830 
  3831 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3832 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3833 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3834 
  3835 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3836 changed order of proof goals in instance proofs.
  3837 
  3838 * The transitivity reasoner for partial and linear orders is set up
  3839 for classes "order" and "linorder".  Instances of the reasoner are available
  3840 in all contexts importing or interpreting the corresponding locales.
  3841 Method "order" invokes the reasoner separately; the reasoner
  3842 is also integrated with the Simplifier as a solver.  Diagnostic
  3843 command 'print_orders' shows the available instances of the reasoner
  3844 in the current context.
  3845 
  3846 * Localized monotonicity predicate in theory "Orderings"; integrated
  3847 lemmas max_of_mono and min_of_mono with this predicate.
  3848 INCOMPATIBILITY.
  3849 
  3850 * Formulation of theorem "dense" changed slightly due to integration
  3851 with new class dense_linear_order.
  3852 
  3853 * Uniform lattice theory development in HOL.
  3854 
  3855     constants "meet" and "join" now named "inf" and "sup"
  3856     constant "Meet" now named "Inf"
  3857 
  3858     classes "meet_semilorder" and "join_semilorder" now named
  3859       "lower_semilattice" and "upper_semilattice"
  3860     class "lorder" now named "lattice"
  3861     class "comp_lat" now named "complete_lattice"
  3862 
  3863     Instantiation of lattice classes allows explicit definitions
  3864     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3865 
  3866   INCOMPATIBILITY.  Theorem renames:
  3867 
  3868     meet_left_le            ~> inf_le1
  3869     meet_right_le           ~> inf_le2
  3870     join_left_le            ~> sup_ge1
  3871     join_right_le           ~> sup_ge2
  3872     meet_join_le            ~> inf_sup_ord
  3873     le_meetI                ~> le_infI
  3874     join_leI                ~> le_supI
  3875     le_meet                 ~> le_inf_iff
  3876     le_join                 ~> ge_sup_conv
  3877     meet_idempotent         ~> inf_idem
  3878     join_idempotent         ~> sup_idem
  3879     meet_comm               ~> inf_commute
  3880     join_comm               ~> sup_commute
  3881     meet_leI1               ~> le_infI1
  3882     meet_leI2               ~> le_infI2
  3883     le_joinI1               ~> le_supI1
  3884     le_joinI2               ~> le_supI2
  3885     meet_assoc              ~> inf_assoc
  3886     join_assoc              ~> sup_assoc
  3887     meet_left_comm          ~> inf_left_commute
  3888     meet_left_idempotent    ~> inf_left_idem
  3889     join_left_comm          ~> sup_left_commute
  3890     join_left_idempotent    ~> sup_left_idem
  3891     meet_aci                ~> inf_aci
  3892     join_aci                ~> sup_aci
  3893     le_def_meet             ~> le_iff_inf
  3894     le_def_join             ~> le_iff_sup
  3895     join_absorp2            ~> sup_absorb2
  3896     join_absorp1            ~> sup_absorb1
  3897     meet_absorp1            ~> inf_absorb1
  3898     meet_absorp2            ~> inf_absorb2
  3899     meet_join_absorp        ~> inf_sup_absorb
  3900     join_meet_absorp        ~> sup_inf_absorb
  3901     distrib_join_le         ~> distrib_sup_le
  3902     distrib_meet_le         ~> distrib_inf_le
  3903 
  3904     add_meet_distrib_left   ~> add_inf_distrib_left
  3905     add_join_distrib_left   ~> add_sup_distrib_left
  3906     is_join_neg_meet        ~> is_join_neg_inf
  3907     is_meet_neg_join        ~> is_meet_neg_sup
  3908     add_meet_distrib_right  ~> add_inf_distrib_right
  3909     add_join_distrib_right  ~> add_sup_distrib_right
  3910     add_meet_join_distribs  ~> add_sup_inf_distribs
  3911     join_eq_neg_meet        ~> sup_eq_neg_inf
  3912     meet_eq_neg_join        ~> inf_eq_neg_sup
  3913     add_eq_meet_join        ~> add_eq_inf_sup
  3914     meet_0_imp_0            ~> inf_0_imp_0
  3915     join_0_imp_0            ~> sup_0_imp_0
  3916     meet_0_eq_0             ~> inf_0_eq_0
  3917     join_0_eq_0             ~> sup_0_eq_0
  3918     neg_meet_eq_join        ~> neg_inf_eq_sup
  3919     neg_join_eq_meet        ~> neg_sup_eq_inf
  3920     join_eq_if              ~> sup_eq_if
  3921 
  3922     mono_meet               ~> mono_inf
  3923     mono_join               ~> mono_sup
  3924     meet_bool_eq            ~> inf_bool_eq
  3925     join_bool_eq            ~> sup_bool_eq
  3926     meet_fun_eq             ~> inf_fun_eq
  3927     join_fun_eq             ~> sup_fun_eq
  3928     meet_set_eq             ~> inf_set_eq
  3929     join_set_eq             ~> sup_set_eq
  3930     meet1_iff               ~> inf1_iff
  3931     meet2_iff               ~> inf2_iff
  3932     meet1I                  ~> inf1I
  3933     meet2I                  ~> inf2I
  3934     meet1D1                 ~> inf1D1
  3935     meet2D1                 ~> inf2D1
  3936     meet1D2                 ~> inf1D2
  3937     meet2D2                 ~> inf2D2
  3938     meet1E                  ~> inf1E
  3939     meet2E                  ~> inf2E
  3940     join1_iff               ~> sup1_iff
  3941     join2_iff               ~> sup2_iff
  3942     join1I1                 ~> sup1I1
  3943     join2I1                 ~> sup2I1
  3944     join1I1                 ~> sup1I1
  3945     join2I2                 ~> sup1I2
  3946     join1CI                 ~> sup1CI
  3947     join2CI                 ~> sup2CI
  3948     join1E                  ~> sup1E
  3949     join2E                  ~> sup2E
  3950 
  3951     is_meet_Meet            ~> is_meet_Inf
  3952     Meet_bool_def           ~> Inf_bool_def
  3953     Meet_fun_def            ~> Inf_fun_def
  3954     Meet_greatest           ~> Inf_greatest
  3955     Meet_lower              ~> Inf_lower
  3956     Meet_set_def            ~> Inf_set_def
  3957 
  3958     Sup_def                 ~> Sup_Inf
  3959     Sup_bool_eq             ~> Sup_bool_def
  3960     Sup_fun_eq              ~> Sup_fun_def
  3961     Sup_set_eq              ~> Sup_set_def
  3962 
  3963     listsp_meetI            ~> listsp_infI
  3964     listsp_meet_eq          ~> listsp_inf_eq
  3965 
  3966     meet_min                ~> inf_min
  3967     join_max                ~> sup_max
  3968 
  3969 * Added syntactic class "size"; overloaded constant "size" now has
  3970 type "'a::size ==> bool"
  3971 
  3972 * Internal reorganisation of `size' of datatypes: size theorems
  3973 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3974 simplification rules by default!); theorems "prod.size" now named
  3975 "*.size".
  3976 
  3977 * Class "div" now inherits from class "times" rather than "type".
  3978 INCOMPATIBILITY.
  3979 
  3980 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3981 Linorder etc.  have disappeared; operations defined in terms of
  3982 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3983 
  3984 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3985 
  3986 * HOL-Word: New extensive library and type for generic, fixed size
  3987 machine words, with arithemtic, bit-wise, shifting and rotating
  3988 operations, reflection into int, nat, and bool lists, automation for
  3989 linear arithmetic (by automatic reflection into nat or int), including
  3990 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3991 arithmetic type classes, supporting automatic simplification of
  3992 numerals on all operations.
  3993 
  3994 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3995 
  3996 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3997 
  3998 * Code generator library theories:
  3999   - Code_Integer represents HOL integers by big integer literals in target
  4000     languages.
  4001   - Code_Char represents HOL characters by character literals in target
  4002     languages.
  4003   - Code_Char_chr like Code_Char, but also offers treatment of character
  4004     codes; includes Code_Integer.
  4005   - Executable_Set allows to generate code for finite sets using lists.
  4006   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4007     denominator).
  4008   - Executable_Real implements a subset of real numbers, namly those
  4009     representable by rational numbers.
  4010   - Efficient_Nat implements natural numbers by integers, which in general will
  4011     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4012     includes Code_Integer.
  4013   - Code_Index provides an additional datatype index which is mapped to
  4014     target-language built-in integers.
  4015   - Code_Message provides an additional datatype message_string which is isomorphic to
  4016     strings; messages are mapped to target-language strings.
  4017 
  4018 * New package for inductive predicates
  4019 
  4020   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4021 
  4022     inductive
  4023       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4024       for z_1 :: U_1 and ... and z_n :: U_m
  4025     where
  4026       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4027     | ...
  4028 
  4029   with full support for type-inference, rather than
  4030 
  4031     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4032 
  4033     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4034     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4035 
  4036     inductive "s z_1 ... z_m"
  4037     intros
  4038       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4039       ...
  4040 
  4041   For backward compatibility, there is a wrapper allowing inductive
  4042   sets to be defined with the new package via
  4043 
  4044     inductive_set
  4045       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4046       for z_1 :: U_1 and ... and z_n :: U_m
  4047     where
  4048       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4049     | ...
  4050 
  4051   or
  4052 
  4053     inductive_set
  4054       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4055       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4056       for z_1 :: U_1 and ... and z_n :: U_m
  4057     where
  4058       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4059     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4060     | ...
  4061 
  4062   if the additional syntax "p ..." is required.
  4063 
  4064   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4065   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4066 
  4067   INCOMPATIBILITIES:
  4068 
  4069   - Since declaration and definition of inductive sets or predicates
  4070     is no longer separated, abbreviations involving the newly
  4071     introduced sets or predicates must be specified together with the
  4072     introduction rules after the 'where' keyword (see above), rather
  4073     than before the actual inductive definition.
  4074 
  4075   - The variables in induction and elimination rules are now
  4076     quantified in the order of their occurrence in the introduction
  4077     rules, rather than in alphabetical order. Since this may break
  4078     some proofs, these proofs either have to be repaired, e.g. by
  4079     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4080     statements of the form
  4081 
  4082       case (rule_i a_i_1 ... a_i_{k_i})
  4083 
  4084     or the old order of quantification has to be restored by explicitly adding
  4085     meta-level quantifiers in the introduction rules, i.e.
  4086 
  4087       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4088 
  4089   - The format of the elimination rules is now
  4090 
  4091       p z_1 ... z_m x_1 ... x_n ==>
  4092         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4093         ==> ... ==> P
  4094 
  4095     for predicates and
  4096 
  4097       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4098         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4099         ==> ... ==> P
  4100 
  4101     for sets rather than
  4102 
  4103       x : s z_1 ... z_m ==>
  4104         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4105         ==> ... ==> P
  4106 
  4107     This may require terms in goals to be expanded to n-tuples
  4108     (e.g. using case_tac or simplification with the split_paired_all
  4109     rule) before the above elimination rule is applicable.
  4110 
  4111   - The elimination or case analysis rules for (mutually) inductive
  4112     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4113     list of rules "p_1_..._p_k.elims" is no longer available.
  4114 
  4115 * New package "function"/"fun" for general recursive functions,
  4116 supporting mutual and nested recursion, definitions in local contexts,
  4117 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4118 for small examples, and the separate tutorial on the function
  4119 package. The old recdef "package" is still available as before, but
  4120 users are encouraged to use the new package.
  4121 
  4122 * Method "lexicographic_order" automatically synthesizes termination
  4123 relations as lexicographic combinations of size measures. 
  4124 
  4125 * Case-expressions allow arbitrary constructor-patterns (including
  4126 "_") and take their order into account, like in functional
  4127 programming.  Internally, this is translated into nested
  4128 case-expressions; missing cases are added and mapped to the predefined
  4129 constant "undefined". In complicated cases printing may no longer show
  4130 the original input but the internal form. Lambda-abstractions allow
  4131 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4132 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4133 variable.
  4134 
  4135 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4136 is an abbreviation for "of_nat :: nat => int". The simplification
  4137 rules for "of_nat" have been changed to work like "int" did
  4138 previously.  Potential INCOMPATIBILITY:
  4139   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4140   - of_nat_diff and of_nat_mult are no longer default simp rules
  4141 
  4142 * Method "algebra" solves polynomial equations over (semi)rings using
  4143 Groebner bases. The (semi)ring structure is defined by locales and the
  4144 tool setup depends on that generic context. Installing the method for
  4145 a specific type involves instantiating the locale and possibly adding
  4146 declarations for computation on the coefficients.  The method is
  4147 already instantiated for natural numbers and for the axiomatic class
  4148 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4149 CALCULEMUS 2007 for the general principles underlying this
  4150 architecture of context-aware proof-tools.
  4151 
  4152 * Method "ferrack" implements quantifier elimination over
  4153 special-purpose dense linear orders using locales (analogous to
  4154 "algebra"). The method is already installed for class
  4155 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4156 rat, etc.
  4157 
  4158 * Former constant "List.op @" now named "List.append".  Use ML
  4159 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4160 circumvent possible incompatibilities when working on ML level.
  4161 
  4162 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4163 
  4164 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4165 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4166 
  4167 * New syntax for Haskell-like list comprehension (input only), eg.
  4168 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4169 
  4170 * The special syntax for function "filter" has changed from [x :
  4171 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4172 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4173 
  4174 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4175 defined on nat only, as an abbreviation for [a..<Suc b]
  4176 INCOMPATIBILITY.
  4177 
  4178 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4179 
  4180 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4181 
  4182 * New lemma collection field_simps (an extension of ring_simps) for
  4183 manipulating (in)equations involving division. Multiplies with all
  4184 denominators that can be proved to be non-zero (in equations) or
  4185 positive/negative (in inequations).
  4186 
  4187 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4188 have been improved and renamed to ring_simps, group_simps and
  4189 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4190 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4191 
  4192 * Theory Library/Commutative_Ring: switched from recdef to function
  4193 package; constants add, mul, pow now curried.  Infix syntax for
  4194 algebraic operations.
  4195 
  4196 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4197 INCOMPATIBILITY.
  4198 
  4199 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4200 INCOMPATIBILITY.
  4201 
  4202 * HOL/records: generalised field-update to take a function on the
  4203 field rather than the new value: r(|A := x|) is translated to A_update
  4204 (K x) r The K-combinator that is internally used is called K_record.
  4205 INCOMPATIBILITY: Usage of the plain update functions has to be
  4206 adapted.
  4207  
  4208 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4209 * x = 0, which are required for a semiring.  Richer structures do not
  4210 inherit from semiring_0 anymore, because this property is a theorem
  4211 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4212 there is more to prove, but this is mostly trivial.
  4213 
  4214 * Class "recpower" is generalized to arbitrary monoids, not just
  4215 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4216 commutativity or semiring properties additionally.
  4217 
  4218 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4219 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4220 better use 'abbreviation'.
  4221 
  4222 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4223 
  4224 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4225 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4226 significant changes for setting up numeral syntax for types:
  4227   - New constants Numeral.pred and Numeral.succ instead
  4228       of former Numeral.bin_pred and Numeral.bin_succ.
  4229   - Use integer operations instead of bin_add, bin_mult and so on.
  4230   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4231   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4232 
  4233 See src/HOL/Integ/IntArith.thy for an example setup.
  4234 
  4235 * Command 'normal_form' computes the normal form of a term that may
  4236 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4237 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4238 heavy-duty computations because the functions are compiled to ML
  4239 first.  Correspondingly, a method "normalization" is provided.  See
  4240 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4241 
  4242 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4243 25 like -->); output depends on the "iff" print_mode, the default is
  4244 "A = B" (with priority 50).
  4245 
  4246 * Relations less (<) and less_eq (<=) are also available on type bool.
  4247 Modified syntax to disallow nesting without explicit parentheses,
  4248 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4249 INCOMPATIBILITY.
  4250 
  4251 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4252 
  4253 * Relation composition operator "op O" now has precedence 75 and binds
  4254 stronger than union and intersection. INCOMPATIBILITY.
  4255 
  4256 * The old set interval syntax "{m..n(}" (and relatives) has been
  4257 removed.  Use "{m..<n}" (and relatives) instead.
  4258 
  4259 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4260 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4261 ``declare [[simproc del: neq]]''.
  4262 
  4263 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4264 True/False.
  4265 
  4266 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4267 
  4268 * Theorem setsum_mult renamed to setsum_right_distrib.
  4269 
  4270 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4271 ``rule'' method.
  4272 
  4273 * Reimplemented methods "sat" and "satx", with several improvements:
  4274 goals no longer need to be stated as "<prems> ==> False", equivalences
  4275 (i.e. "=" on type bool) are handled, variable names of the form
  4276 "lit_<n>" are no longer reserved, significant speedup.
  4277 
  4278 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4279 zChaff is still supported as well.
  4280 
  4281 * 'inductive' and 'datatype': provide projections of mutual rules,
  4282 bundled as foo_bar.inducts;
  4283 
  4284 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4285 Library.
  4286 
  4287 * Library: moved theory Accessible_Part to main HOL.
  4288 
  4289 * Library: added theory Coinductive_List of potentially infinite lists
  4290 as greatest fixed-point.
  4291 
  4292 * Library: added theory AssocList which implements (finite) maps as
  4293 association lists.
  4294 
  4295 * Method "evaluation" solves goals (i.e. a boolean expression)
  4296 efficiently by compiling it to ML.  The goal is "proved" (via an
  4297 oracle) if it evaluates to True.
  4298 
  4299 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4300 also when invoked by the simplifier.  This results in the Simplifier
  4301 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4302 Configuration option fast_arith_split_limit=0 recovers the old
  4303 behavior.
  4304 
  4305 * Support for hex (0x20) and binary (0b1001) numerals.
  4306 
  4307 * New method: reify eqs (t), where eqs are equations for an
  4308 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4309 parameter, computes a term s::'b and a list xs::'a list and proves the
  4310 theorem I xs s = t. This is also known as reification or quoting. The
  4311 resulting theorem is applied to the subgoal to substitute t with I xs
  4312 s.  If t is omitted, the subgoal itself is reified.
  4313 
  4314 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4315 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4316 where f is supposed to be a computable function (in the sense of code
  4317 generattion). The method uses reify to compute s and xs as above then
  4318 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4319 r and finally gets the theorem t = r, which is again applied to the
  4320 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4321 
  4322 * Reflection: Automatic reification now handels binding, an example is
  4323 available in src/HOL/ex/ReflectionEx.thy
  4324 
  4325 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4326 command 'statespace' that is similar to 'record', but introduces an
  4327 abstract specification based on the locale infrastructure instead of
  4328 HOL types.  This leads to extra flexibility in composing state spaces,
  4329 in particular multiple inheritance and renaming of components.
  4330 
  4331 
  4332 *** HOL-Complex ***
  4333 
  4334 * Hyperreal: Functions root and sqrt are now defined on negative real
  4335 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4336 Nonnegativity side conditions have been removed from many lemmas, so
  4337 that more subgoals may now be solved by simplification; potential
  4338 INCOMPATIBILITY.
  4339 
  4340 * Real: new type classes formalize real normed vector spaces and
  4341 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4342 and norm :: 'a => real.
  4343 
  4344 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4345 reals into other types. The overloaded constant Reals :: 'a set is now
  4346 defined as range of_real; potential INCOMPATIBILITY.
  4347 
  4348 * Real: proper support for ML code generation, including 'quickcheck'.
  4349 Reals are implemented as arbitrary precision rationals.
  4350 
  4351 * Hyperreal: Several constants that previously worked only for the
  4352 reals have been generalized, so they now work over arbitrary vector
  4353 spaces. Type annotations may need to be added in some cases; potential
  4354 INCOMPATIBILITY.
  4355 
  4356   Infinitesimal  :: ('a::real_normed_vector) star set
  4357   HFinite        :: ('a::real_normed_vector) star set
  4358   HInfinite      :: ('a::real_normed_vector) star set
  4359   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4360   monad          :: ('a::real_normed_vector) star => 'a star set
  4361   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4362   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4363   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4364   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4365   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4366   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4367   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4368   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4369   sgn            :: 'a::real_normed_vector => 'a
  4370   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4371 
  4372 * Complex: Some complex-specific constants are now abbreviations for
  4373 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4374 hnorm.  Other constants have been entirely removed in favor of the
  4375 polymorphic versions (INCOMPATIBILITY):
  4376 
  4377   approx        <-- capprox
  4378   HFinite       <-- CFinite
  4379   HInfinite     <-- CInfinite
  4380   Infinitesimal <-- CInfinitesimal
  4381   monad         <-- cmonad
  4382   galaxy        <-- cgalaxy
  4383   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4384   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4385   (ns)deriv     <-- (ns)cderiv
  4386 
  4387 
  4388 *** HOL-Algebra ***
  4389 
  4390 * Formalisation of ideals and the quotient construction over rings.
  4391 
  4392 * Order and lattice theory no longer based on records.
  4393 INCOMPATIBILITY.
  4394 
  4395 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4396 greatest_closed.  INCOMPATIBILITY.
  4397 
  4398 * Method algebra is now set up via an attribute.  For examples see
  4399 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4400 of algebraic structures.
  4401 
  4402 * Renamed theory CRing to Ring.
  4403 
  4404 
  4405 *** HOL-Nominal ***
  4406 
  4407 * Substantial, yet incomplete support for nominal datatypes (binding
  4408 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4409 src/HOL/Nominal/Examples.  Prospective users should consult
  4410 http://isabelle.in.tum.de/nominal/
  4411 
  4412 
  4413 *** ML ***
  4414 
  4415 * ML basics: just one true type int, which coincides with IntInf.int
  4416 (even on SML/NJ).
  4417 
  4418 * ML within Isar: antiquotations allow to embed statically-checked
  4419 formal entities in the source, referring to the context available at
  4420 compile-time.  For example:
  4421 
  4422 ML {* @{sort "{zero,one}"} *}
  4423 ML {* @{typ "'a => 'b"} *}
  4424 ML {* @{term "%x. x"} *}
  4425 ML {* @{prop "x == y"} *}
  4426 ML {* @{ctyp "'a => 'b"} *}
  4427 ML {* @{cterm "%x. x"} *}
  4428 ML {* @{cprop "x == y"} *}
  4429 ML {* @{thm asm_rl} *}
  4430 ML {* @{thms asm_rl} *}
  4431 ML {* @{type_name c} *}
  4432 ML {* @{type_syntax c} *}
  4433 ML {* @{const_name c} *}
  4434 ML {* @{const_syntax c} *}
  4435 ML {* @{context} *}
  4436 ML {* @{theory} *}
  4437 ML {* @{theory Pure} *}
  4438 ML {* @{theory_ref} *}
  4439 ML {* @{theory_ref Pure} *}
  4440 ML {* @{simpset} *}
  4441 ML {* @{claset} *}
  4442 ML {* @{clasimpset} *}
  4443 
  4444 The same works for sources being ``used'' within an Isar context.
  4445 
  4446 * ML in Isar: improved error reporting; extra verbosity with
  4447 ML_Context.trace enabled.
  4448 
  4449 * Pure/General/table.ML: the join operations now works via exceptions
  4450 DUP/SAME instead of type option. This is simpler in simple cases, and
  4451 admits slightly more efficient complex applications.
  4452 
  4453 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4454 use Context.generic instead of just theory.
  4455 
  4456 * Pure: datatype Context.generic joins theory/Proof.context and
  4457 provides some facilities for code that works in either kind of
  4458 context, notably GenericDataFun for uniform theory and proof data.
  4459 
  4460 * Pure: simplified internal attribute type, which is now always
  4461 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4462 local (Proof.context) attributes have been discontinued, while
  4463 minimizing code duplication. Thm.rule_attribute and
  4464 Thm.declaration_attribute build canonical attributes; see also structure
  4465 Context for further operations on Context.generic, notably
  4466 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4467 declarations and definitions.
  4468 
  4469 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4470 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4471 init only required for impure data. INCOMPATIBILITY: empty really need
  4472 to be empty (no dependencies on theory content!)
  4473 
  4474 * Pure/kernel: consts certification ignores sort constraints given in
  4475 signature declarations. (This information is not relevant to the
  4476 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4477 potential INCOMPATIBILITY.
  4478 
  4479 * Pure: axiomatic type classes are now purely definitional, with
  4480 explicit proofs of class axioms and super class relations performed
  4481 internally. See Pure/axclass.ML for the main internal interfaces --
  4482 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4483 AxClass.axiomatize_class/classrel/arity supersede
  4484 Sign.add_classes/classrel/arities.
  4485 
  4486 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4487 global/local versions on theory vs. Proof.context have been
  4488 discontinued; Attrib.syntax and Method.syntax have been adapted
  4489 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4490 attributes, methods, etc.
  4491 
  4492 * Pure: several functions of signature "... -> theory -> theory * ..."
  4493 have been reoriented to "... -> theory -> ... * theory" in order to
  4494 allow natural usage in combination with the ||>, ||>>, |-> and
  4495 fold_map combinators.
  4496 
  4497 * Pure: official theorem names (closed derivations) and additional
  4498 comments (tags) are now strictly separate.  Name hints -- which are
  4499 maintained as tags -- may be attached any time without affecting the
  4500 derivation.
  4501 
  4502 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4503 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4504 achieve the old behaviour.
  4505 
  4506 * Pure: the "Goal" constant is now called "prop", supporting a
  4507 slightly more general idea of ``protecting'' meta-level rule
  4508 statements.
  4509 
  4510 * Pure: Logic.(un)varify only works in a global context, which is now
  4511 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4512 Logic.legacy_(un)varify as temporary workaround.
  4513 
  4514 * Pure: structure Name provides scalable operations for generating
  4515 internal variable names, notably Name.variants etc.  This replaces
  4516 some popular functions from term.ML:
  4517 
  4518   Term.variant		->  Name.variant
  4519   Term.variantlist	->  Name.variant_list
  4520   Term.invent_names	->  Name.invent_list
  4521 
  4522 Note that low-level renaming rarely occurs in new code -- operations
  4523 from structure Variable are used instead (see below).
  4524 
  4525 * Pure: structure Variable provides fundamental operations for proper
  4526 treatment of fixed/schematic variables in a context.  For example,
  4527 Variable.import introduces fixes for schematics of given facts and
  4528 Variable.export reverses the effect (up to renaming) -- this replaces
  4529 various freeze_thaw operations.
  4530 
  4531 * Pure: structure Goal provides simple interfaces for
  4532 init/conclude/finish and tactical prove operations (replacing former
  4533 Tactic.prove).  Goal.prove is the canonical way to prove results
  4534 within a given context; Goal.prove_global is a degraded version for
  4535 theory level goals, including a global Drule.standard.  Note that
  4536 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4537 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4538 in a locale context).
  4539 
  4540 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4541 and type checking (Syntax.check_term etc.), with common combinations
  4542 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4543 which are considered legacy and await removal.
  4544 
  4545 * Pure/Syntax: generic interfaces for type unchecking
  4546 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4547 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4548 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4549 available for convenience, but refer to the very same operations using
  4550 a mere theory instead of a full context.
  4551 
  4552 * Isar: simplified treatment of user-level errors, using exception
  4553 ERROR of string uniformly.  Function error now merely raises ERROR,
  4554 without any side effect on output channels.  The Isar toplevel takes
  4555 care of proper display of ERROR exceptions.  ML code may use plain
  4556 handle/can/try; cat_error may be used to concatenate errors like this:
  4557 
  4558   ... handle ERROR msg => cat_error msg "..."
  4559 
  4560 Toplevel ML code (run directly or through the Isar toplevel) may be
  4561 embedded into the Isar toplevel with exception display/debug like
  4562 this:
  4563 
  4564   Isar.toplevel (fn () => ...)
  4565 
  4566 INCOMPATIBILITY, removed special transform_error facilities, removed
  4567 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4568 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4569 -- use plain ERROR instead.
  4570 
  4571 * Isar: theory setup now has type (theory -> theory), instead of a
  4572 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4573 
  4574 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4575 ProofContext.debug/verbose flags.
  4576 
  4577 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4578 theory before entering a proof state.  Transactions now always see a
  4579 quasi-functional intermediate checkpoint, both in interactive and
  4580 batch mode.
  4581 
  4582 * Isar: simplified interfaces for outer syntax.  Renamed
  4583 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4584 OuterSyntax.add_parsers -- this functionality is now included in
  4585 OuterSyntax.command etc.  INCOMPATIBILITY.
  4586 
  4587 * Simplifier: the simpset of a running simplification process now
  4588 contains a proof context (cf. Simplifier.the_context), which is the
  4589 very context that the initial simpset has been retrieved from (by
  4590 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4591 (solver, looper etc.) may depend on arbitrary proof data.
  4592 
  4593 * Simplifier.inherit_context inherits the proof context (plus the
  4594 local bounds) of the current simplification process; any simproc
  4595 etc. that calls the Simplifier recursively should do this!  Removed
  4596 former Simplifier.inherit_bounds, which is already included here --
  4597 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4598 specify an explicit context using Simplifier.context/theory_context.
  4599 
  4600 * Simplifier/Classical Reasoner: more abstract interfaces
  4601 change_simpset/claset for modifying the simpset/claset reference of a
  4602 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4603 INCOMPATIBILITY.
  4604 
  4605 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4606 "Trueprop" etc.
  4607 
  4608 
  4609 *** System ***
  4610 
  4611 * settings: the default heap location within ISABELLE_HOME_USER now
  4612 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4613 Isabelle installations.
  4614 
  4615 * isabelle-process: option -S (secure mode) disables some critical
  4616 operations, notably runtime compilation and evaluation of ML source
  4617 code.
  4618 
  4619 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4620 
  4621 * Support for parallel execution, using native multicore support of
  4622 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4623 independent theories, according to the given theory header
  4624 specifications. The maximum number of worker threads is specified via
  4625 usedir option -M or the "max-threads" setting in Proof General. A
  4626 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4627 to 6 on a 8-core machine.  User-code needs to observe certain
  4628 guidelines for thread-safe programming, see appendix A in the Isar
  4629 Implementation manual.
  4630 
  4631 
  4632 
  4633 New in Isabelle2005 (October 2005)
  4634 ----------------------------------
  4635 
  4636 *** General ***
  4637 
  4638 * Theory headers: the new header syntax for Isar theories is
  4639 
  4640   theory <name>
  4641   imports <theory1> ... <theoryN>
  4642   uses <file1> ... <fileM>
  4643   begin
  4644 
  4645 where the 'uses' part is optional.  The previous syntax
  4646 
  4647   theory <name> = <theory1> + ... + <theoryN>:
  4648 
  4649 will disappear in the next release.  Use isatool fixheaders to convert
  4650 existing theory files.  Note that there is no change in ancient
  4651 non-Isar theories now, but these will disappear soon.
  4652 
  4653 * Theory loader: parent theories can now also be referred to via
  4654 relative and absolute paths.
  4655 
  4656 * Command 'find_theorems' searches for a list of criteria instead of a
  4657 list of constants. Known criteria are: intro, elim, dest, name:string,
  4658 simp:term, and any term. Criteria can be preceded by '-' to select
  4659 theorems that do not match. Intro, elim, dest select theorems that
  4660 match the current goal, name:s selects theorems whose fully qualified
  4661 name contain s, and simp:term selects all simplification rules whose
  4662 lhs match term.  Any other term is interpreted as pattern and selects
  4663 all theorems matching the pattern. Available in ProofGeneral under
  4664 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4665 
  4666   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4667 
  4668 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4669 matching the current goal as introduction rule and not having "HOL."
  4670 in their name (i.e. not being defined in theory HOL).
  4671 
  4672 * Command 'thms_containing' has been discontinued in favour of
  4673 'find_theorems'; INCOMPATIBILITY.
  4674 
  4675 * Communication with Proof General is now 8bit clean, which means that
  4676 Unicode text in UTF-8 encoding may be used within theory texts (both
  4677 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4678 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4679 
  4680   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4681   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4682 
  4683 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4684 Classical Reasoner.  Typical big applications run around 2 times
  4685 faster.
  4686 
  4687 
  4688 *** Document preparation ***
  4689 
  4690 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4691 of raw sources.  Only those symbols that do not require additional
  4692 LaTeX packages (depending on comments in isabellesym.sty) are
  4693 displayed properly, everything else is left verbatim.  isatool display
  4694 and isatool print are used as front ends (these are subject to the
  4695 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4696 
  4697 * Command tags control specific markup of certain regions of text,
  4698 notably folding and hiding.  Predefined tags include "theory" (for
  4699 theory begin and end), "proof" for proof commands, and "ML" for
  4700 commands involving ML code; the additional tags "visible" and
  4701 "invisible" are unused by default.  Users may give explicit tag
  4702 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4703 interpretation of tags is determined by the LaTeX job during document
  4704 preparation: see option -V of isatool usedir, or options -n and -t of
  4705 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4706 \isadroptag.
  4707 
  4708 Several document versions may be produced at the same time via isatool
  4709 usedir (the generated index.html will link all of them).  Typical
  4710 specifications include ''-V document=theory,proof,ML'' to present
  4711 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4712 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4713 these parts without any formal replacement text.  The Isabelle site
  4714 default settings produce ''document'' and ''outline'' versions as
  4715 specified above.
  4716 
  4717 * Several new antiquotations:
  4718 
  4719   @{term_type term} prints a term with its type annotated;
  4720 
  4721   @{typeof term} prints the type of a term;
  4722 
  4723   @{const const} is the same as @{term const}, but checks that the
  4724   argument is a known logical constant;
  4725 
  4726   @{term_style style term} and @{thm_style style thm} print a term or
  4727   theorem applying a "style" to it
  4728 
  4729   @{ML text}
  4730 
  4731 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4732 definitions, equations, inequations etc., 'concl' printing only the
  4733 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4734 to print the specified premise.  TermStyle.add_style provides an ML
  4735 interface for introducing further styles.  See also the "LaTeX Sugar"
  4736 document practical applications.  The ML antiquotation prints
  4737 type-checked ML expressions verbatim.
  4738 
  4739 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4740 and 'text' support optional locale specification '(in loc)', which
  4741 specifies the default context for interpreting antiquotations.  For
  4742 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4743 
  4744 * Option 'locale=NAME' of antiquotations specifies an alternative
  4745 context interpreting the subsequent argument.  For example: @{thm
  4746 [locale=lattice] inf_assoc}.
  4747 
  4748 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4749 a proof context.
  4750 
  4751 * Proper output of antiquotations for theory commands involving a
  4752 proof context (such as 'locale' or 'theorem (in loc) ...').
  4753 
  4754 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4755 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4756 
  4757 * isatool usedir: new option -C (default true) controls whether option
  4758 -D should include a copy of the original document directory; -C false
  4759 prevents unwanted effects such as copying of administrative CVS data.
  4760 
  4761 
  4762 *** Pure ***
  4763 
  4764 * Considerably improved version of 'constdefs' command.  Now performs
  4765 automatic type-inference of declared constants; additional support for
  4766 local structure declarations (cf. locales and HOL records), see also
  4767 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4768 sequential dependencies of definitions within a single 'constdefs'
  4769 section; moreover, the declared name needs to be an identifier.  If
  4770 all fails, consider to fall back on 'consts' and 'defs' separately.
  4771 
  4772 * Improved indexed syntax and implicit structures.  First of all,
  4773 indexed syntax provides a notational device for subscripted
  4774 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4775 expressions.  Secondly, in a local context with structure
  4776 declarations, number indexes \<^sub>n or the empty index (default
  4777 number 1) refer to a certain fixed variable implicitly; option
  4778 show_structs controls printing of implicit structures.  Typical
  4779 applications of these concepts involve record types and locales.
  4780 
  4781 * New command 'no_syntax' removes grammar declarations (and
  4782 translations) resulting from the given syntax specification, which is
  4783 interpreted in the same manner as for the 'syntax' command.
  4784 
  4785 * 'Advanced' translation functions (parse_translation etc.) may depend
  4786 on the signature of the theory context being presently used for
  4787 parsing/printing, see also isar-ref manual.
  4788 
  4789 * Improved 'oracle' command provides a type-safe interface to turn an
  4790 ML expression of type theory -> T -> term into a primitive rule of
  4791 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4792 is already included here); see also FOL/ex/IffExample.thy;
  4793 INCOMPATIBILITY.
  4794 
  4795 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4796 before); "cI" is no longer bound, use "c.intro" instead.
  4797 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4798 axclasses vs. locales.
  4799 
  4800 * Improved internal renaming of symbolic identifiers -- attach primes
  4801 instead of base 26 numbers.
  4802 
  4803 * New flag show_question_marks controls printing of leading question
  4804 marks in schematic variable names.
  4805 
  4806 * In schematic variable names, *any* symbol following \<^isub> or
  4807 \<^isup> is now treated as part of the base name.  For example, the
  4808 following works without printing of awkward ".0" indexes:
  4809 
  4810   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4811     by simp
  4812 
  4813 * Inner syntax includes (*(*nested*) comments*).
  4814 
  4815 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4816 annotations as "(00...)".
  4817 
  4818 * Clear separation of logical types and nonterminals, where the latter
  4819 may only occur in 'syntax' specifications or type abbreviations.
  4820 Before that distinction was only partially implemented via type class
  4821 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4822 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4823 exotic syntax specifications may require further adaption
  4824 (e.g. Cube/Cube.thy).
  4825 
  4826 * Removed obsolete type class "logic", use the top sort {} instead.
  4827 Note that non-logical types should be declared as 'nonterminals'
  4828 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4829 specifications.
  4830 
  4831 * Attributes 'induct' and 'cases': type or set names may now be
  4832 locally fixed variables as well.
  4833 
  4834 * Simplifier: can now control the depth to which conditional rewriting
  4835 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4836 Limit.
  4837 
  4838 * Simplifier: simplification procedures may now take the current
  4839 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4840 interface), which is very useful for calling the Simplifier
  4841 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4842 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4843 low-level mk_simproc no longer applies Logic.varify internally, to
  4844 allow for use in a context of fixed variables.
  4845 
  4846 * thin_tac now works even if the assumption being deleted contains !!
  4847 or ==>.  More generally, erule now works even if the major premise of
  4848 the elimination rule contains !! or ==>.
  4849 
  4850 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4851 
  4852 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4853 from Pure, which contains all common declarations already.  Both
  4854 theories are defined via plain Isabelle/Isar .thy files.
  4855 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4856 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4857 use isatool fixcpure to adapt your theory and ML sources.
  4858 
  4859 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4860 selections of theorems in named facts via index ranges.
  4861 
  4862 * 'print_theorems': in theory mode, really print the difference
  4863 wrt. the last state (works for interactive theory development only),
  4864 in proof mode print all local facts (cf. 'print_facts');
  4865 
  4866 * 'hide': option '(open)' hides only base names.
  4867 
  4868 * More efficient treatment of intermediate checkpoints in interactive
  4869 theory development.
  4870 
  4871 * Code generator is now invoked via code_module (incremental code
  4872 generation) and code_library (modular code generation, ML structures
  4873 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4874 must be quoted when used as identifiers.
  4875 
  4876 * New 'value' command for reading, evaluating and printing terms using
  4877 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4878 quoted when used as identifier.
  4879 
  4880 
  4881 *** Locales ***
  4882 
  4883 * New commands for the interpretation of locale expressions in
  4884 theories (1), locales (2) and proof contexts (3).  These generate
  4885 proof obligations from the expression specification.  After the
  4886 obligations have been discharged, theorems of the expression are added
  4887 to the theory, target locale or proof context.  The synopsis of the
  4888 commands is a follows:
  4889 
  4890   (1) interpretation expr inst
  4891   (2) interpretation target < expr
  4892   (3) interpret expr inst
  4893 
  4894 Interpretation in theories and proof contexts require a parameter
  4895 instantiation of terms from the current context.  This is applied to
  4896 specifications and theorems of the interpreted expression.
  4897 Interpretation in locales only permits parameter renaming through the
  4898 locale expression.  Interpretation is smart in that interpretations
  4899 that are active already do not occur in proof obligations, neither are
  4900 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4901 inspect active interpretations of a particular locale.  For details,
  4902 see the Isar Reference manual.  Examples can be found in
  4903 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4904 
  4905 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4906 'interpret' instead.
  4907 
  4908 * New context element 'constrains' for adding type constraints to
  4909 parameters.
  4910 
  4911 * Context expressions: renaming of parameters with syntax
  4912 redeclaration.
  4913 
  4914 * Locale declaration: 'includes' disallowed.
  4915 
  4916 * Proper static binding of attribute syntax -- i.e. types / terms /
  4917 facts mentioned as arguments are always those of the locale definition
  4918 context, independently of the context of later invocations.  Moreover,
  4919 locale operations (renaming and type / term instantiation) are applied
  4920 to attribute arguments as expected.
  4921 
  4922 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4923 actual attributes; rare situations may require Attrib.attribute to
  4924 embed those attributes into Attrib.src that lack concrete syntax.
  4925 Attribute implementations need to cooperate properly with the static
  4926 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4927 Attrib.XXX_thm etc. already do the right thing without further
  4928 intervention.  Only unusual applications -- such as "where" or "of"
  4929 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4930 on the context and the facts involved -- may have to assign parsed
  4931 values to argument tokens explicitly.
  4932 
  4933 * Changed parameter management in theorem generation for long goal
  4934 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4935 theorem statement in rare situations.
  4936 
  4937 * Locale inspection command 'print_locale' omits notes elements.  Use
  4938 'print_locale!' to have them included in the output.
  4939 
  4940 
  4941 *** Provers ***
  4942 
  4943 * Provers/hypsubst.ML: improved version of the subst method, for
  4944 single-step rewriting: it now works in bound variable contexts. New is
  4945 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4946 rewrite a different subterm than the original subst method, which is
  4947 still available as 'simplesubst'.
  4948 
  4949 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4950 and quasi orders.
  4951 
  4952 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4953 reflexive-transitive closure of relations.
  4954 
  4955 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4956 limit (previously hard-coded with a value of 20) user-definable.
  4957 
  4958 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4959 is peformed already.  Object-logics merely need to finish their
  4960 initial simpset configuration as before.  INCOMPATIBILITY.
  4961 
  4962 
  4963 *** HOL ***
  4964 
  4965 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4966 
  4967   syntax (epsilon)
  4968     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4969 
  4970 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4971 and x-symbol; use option '-m epsilon' to get it actually printed.
  4972 Moreover, the mathematically important symbolic identifier \<epsilon>
  4973 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4974 
  4975 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4976 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4977 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4978 support corresponding Isar calculations.
  4979 
  4980 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4981 instead of ":".
  4982 
  4983 * theory SetInterval: changed the syntax for open intervals:
  4984 
  4985   Old       New
  4986   {..n(}    {..<n}
  4987   {)n..}    {n<..}
  4988   {m..n(}   {m..<n}
  4989   {)m..n}   {m<..n}
  4990   {)m..n(}  {m<..<n}
  4991 
  4992 The old syntax is still supported but will disappear in the next
  4993 release.  For conversion use the following Emacs search and replace
  4994 patterns (these are not perfect but work quite well):
  4995 
  4996   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4997   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4998 
  4999 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5000 equalities in commutative rings; method 'algebra' provides a generic
  5001 interface.
  5002 
  5003 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5004 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5005 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5006 be a tuple pattern.
  5007 
  5008 Some new syntax forms are available:
  5009 
  5010   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5011   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5012   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5013   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5014 
  5015 The latter form "\<Sum>x < k. e" used to be based on a separate
  5016 function "Summation", which has been discontinued.
  5017 
  5018 * theory Finite_Set: in structured induction proofs, the insert case
  5019 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5020 (insert F x)'.
  5021 
  5022 * The 'refute' command has been extended to support a much larger
  5023 fragment of HOL, including axiomatic type classes, constdefs and
  5024 typedefs, inductive datatypes and recursion.
  5025 
  5026 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5027 Requires zChaff with proof generation to be installed.  See
  5028 HOL/ex/SAT_Examples.thy for examples.
  5029 
  5030 * Datatype induction via method 'induct' now preserves the name of the
  5031 induction variable. For example, when proving P(xs::'a list) by
  5032 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5033 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5034 in unstructured proof scripts.
  5035 
  5036 * Reworked implementation of records.  Improved scalability for
  5037 records with many fields, avoiding performance problems for type
  5038 inference. Records are no longer composed of nested field types, but
  5039 of nested extension types. Therefore the record type only grows linear
  5040 in the number of extensions and not in the number of fields.  The
  5041 top-level (users) view on records is preserved.  Potential
  5042 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5043 old record representation. The type generated for a record is called
  5044 <record_name>_ext_type.
  5045 
  5046 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5047 proofs triggered by a record definition or a simproc (if
  5048 quick_and_dirty is enabled).  Definitions of large records can take
  5049 quite long.
  5050 
  5051 New simproc record_upd_simproc for simplification of multiple record
  5052 updates enabled by default.  Moreover, trivial updates are also
  5053 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5054 occasionally, since simplification is more powerful by default.
  5055 
  5056 * typedef: proper support for polymorphic sets, which contain extra
  5057 type-variables in the term.
  5058 
  5059 * Simplifier: automatically reasons about transitivity chains
  5060 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5061 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5062 old proofs break occasionally as simplification may now solve more
  5063 goals than previously.
  5064 
  5065 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5066 present.  Works for all partial orders (class "order"), in particular
  5067 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5068 just like y <= x.
  5069 
  5070 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5071 bound variable or a constant then the let is unfolded.  Otherwise
  5072 first a is simplified to b, and then f b is simplified to g. If
  5073 possible we abstract b from g arriving at "let x = b in h x",
  5074 otherwise we unfold the let and arrive at g.  The simproc can be
  5075 enabled/disabled by the reference use_let_simproc.  Potential
  5076 INCOMPATIBILITY since simplification is more powerful by default.
  5077 
  5078 * Classical reasoning: the meson method now accepts theorems as arguments.
  5079 
  5080 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5081 jobs to provide advice on the provability of subgoals.
  5082 
  5083 * Theory OrderedGroup and Ring_and_Field: various additions and
  5084 improvements to faciliate calculations involving equalities and
  5085 inequalities.
  5086 
  5087 The following theorems have been eliminated or modified
  5088 (INCOMPATIBILITY):
  5089 
  5090   abs_eq             now named abs_of_nonneg
  5091   abs_of_ge_0        now named abs_of_nonneg
  5092   abs_minus_eq       now named abs_of_nonpos
  5093   imp_abs_id         now named abs_of_nonneg
  5094   imp_abs_neg_id     now named abs_of_nonpos
  5095   mult_pos           now named mult_pos_pos
  5096   mult_pos_le        now named mult_nonneg_nonneg
  5097   mult_pos_neg_le    now named mult_nonneg_nonpos
  5098   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5099   mult_neg           now named mult_neg_neg
  5100   mult_neg_le        now named mult_nonpos_nonpos
  5101 
  5102 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5103      
  5104      zero_le_square
  5105      not_square_less_zero 
  5106 
  5107   The following lemmas have been deleted from Real/RealPow:
  5108   
  5109      realpow_zero_zero
  5110      realpow_two
  5111      realpow_less
  5112      zero_le_power
  5113      realpow_two_le
  5114      abs_realpow_two
  5115      realpow_two_abs     
  5116 
  5117 * Theory Parity: added rules for simplifying exponents.
  5118 
  5119 * Theory List:
  5120 
  5121 The following theorems have been eliminated or modified
  5122 (INCOMPATIBILITY):
  5123 
  5124   list_all_Nil       now named list_all.simps(1)
  5125   list_all_Cons      now named list_all.simps(2)
  5126   list_all_conv      now named list_all_iff
  5127   set_mem_eq         now named mem_iff
  5128 
  5129 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5130 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5131 
  5132 
  5133 *** HOL-Complex ***
  5134 
  5135 * Theory RealDef: better support for embedding natural numbers and
  5136 integers in the reals.
  5137 
  5138 The following theorems have been eliminated or modified
  5139 (INCOMPATIBILITY):
  5140 
  5141   exp_ge_add_one_self  now requires no hypotheses
  5142   real_of_int_add      reversed direction of equality (use [symmetric])
  5143   real_of_int_minus    reversed direction of equality (use [symmetric])
  5144   real_of_int_diff     reversed direction of equality (use [symmetric])
  5145   real_of_int_mult     reversed direction of equality (use [symmetric])
  5146 
  5147 * Theory RComplete: expanded support for floor and ceiling functions.
  5148 
  5149 * Theory Ln is new, with properties of the natural logarithm
  5150 
  5151 * Hyperreal: There is a new type constructor "star" for making
  5152 nonstandard types.  The old type names are now type synonyms:
  5153 
  5154   hypreal = real star
  5155   hypnat = nat star
  5156   hcomplex = complex star
  5157 
  5158 * Hyperreal: Many groups of similarly-defined constants have been
  5159 replaced by polymorphic versions (INCOMPATIBILITY):
  5160 
  5161   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5162 
  5163   starset      <-- starsetNat, starsetC
  5164   *s*          <-- *sNat*, *sc*
  5165   starset_n    <-- starsetNat_n, starsetC_n
  5166   *sn*         <-- *sNatn*, *scn*
  5167   InternalSets <-- InternalNatSets, InternalCSets
  5168 
  5169   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5170   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5171   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5172   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5173   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5174 
  5175 * Hyperreal: Many type-specific theorems have been removed in favor of
  5176 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5177 
  5178   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5179   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5180   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5181   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5182   right_minus <-- hypreal_add_minus
  5183   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5184   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5185   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5186   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5187   mult_1_right <-- hcomplex_mult_one_right
  5188   mult_zero_left <-- hcomplex_mult_zero_left
  5189   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5190   right_distrib <-- hypnat_add_mult_distrib2
  5191   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5192   right_inverse <-- hypreal_mult_inverse
  5193   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5194   order_refl <-- {hypreal,hypnat}_le_refl
  5195   order_trans <-- {hypreal,hypnat}_le_trans
  5196   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5197   order_less_le <-- {hypreal,hypnat}_less_le
  5198   linorder_linear <-- {hypreal,hypnat}_le_linear
  5199   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5200   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5201   add_nonneg_nonneg <-- hypreal_le_add_order
  5202 
  5203 * Hyperreal: Separate theorems having to do with type-specific
  5204 versions of constants have been merged into theorems that apply to the
  5205 new polymorphic constants (INCOMPATIBILITY):
  5206 
  5207   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5208   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5209   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5210   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5211   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5212   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5213   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5214   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5215   STAR_diff <-- {STAR,STARC}_diff
  5216   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5217     STARC_hcomplex_of_complex}_image_subset
  5218   starset_n_Un <-- starset{Nat,C}_n_Un
  5219   starset_n_Int <-- starset{Nat,C}_n_Int
  5220   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5221   starset_n_diff <-- starset{Nat,C}_n_diff
  5222   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5223   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5224   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5225   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5226   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5227   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5228   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5229   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5230   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5231   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5232   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5233   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5234   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5235   starfun_diff <-- starfun{C,RC,CR}_diff
  5236   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5237   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5238   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5239   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5240   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5241   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5242   starfun_Id <-- starfunC_Id
  5243   starfun_approx <-- starfun{Nat,CR}_approx
  5244   starfun_capprox <-- starfun{C,RC}_capprox
  5245   starfun_abs <-- starfunNat_rabs
  5246   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5247   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5248   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5249   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5250   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5251   starfun_add_approx <-- starfunCR_add_approx
  5252   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5253   starfun_divide <-- starfun{C,CR,RC}_divide
  5254   starfun_n <-- starfun{Nat,C}_n
  5255   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5256   starfun_n_add <-- starfun{Nat,C}_n_add
  5257   starfun_n_add_minus <-- starfunNat_n_add_minus
  5258   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5259   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5260   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5261 
  5262   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5263   star_n_minus <-- {hypreal,hcomplex}_minus
  5264   star_n_diff <-- {hypreal,hcomplex}_diff
  5265   star_n_mult <-- {hypreal,hcomplex}_mult
  5266   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5267   star_n_le <-- {hypreal,hypnat}_le
  5268   star_n_less <-- {hypreal,hypnat}_less
  5269   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5270   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5271   star_n_abs <-- hypreal_hrabs
  5272   star_n_divide <-- hcomplex_divide
  5273 
  5274   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5275   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5276   star_of_diff <-- hypreal_of_real_diff
  5277   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5278   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5279   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5280   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5281   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5282   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5283   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5284   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5285   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5286   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5287   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5288   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5289   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5290   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5291   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5292   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5293   star_of_power <-- hypreal_of_real_power
  5294   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5295 
  5296 * Hyperreal: new method "transfer" that implements the transfer
  5297 principle of nonstandard analysis. With a subgoal that mentions
  5298 nonstandard types like "'a star", the command "apply transfer"
  5299 replaces it with an equivalent one that mentions only standard types.
  5300 To be successful, all free variables must have standard types; non-
  5301 standard variables must have explicit universal quantifiers.
  5302 
  5303 * Hyperreal: A theory of Taylor series.
  5304 
  5305 
  5306 *** HOLCF ***
  5307 
  5308 * Discontinued special version of 'constdefs' (which used to support
  5309 continuous functions) in favor of the general Pure one with full
  5310 type-inference.
  5311 
  5312 * New simplification procedure for solving continuity conditions; it
  5313 is much faster on terms with many nested lambda abstractions (cubic
  5314 instead of exponential time).
  5315 
  5316 * New syntax for domain package: selector names are now optional.
  5317 Parentheses should be omitted unless argument is lazy, for example:
  5318 
  5319   domain 'a stream = cons "'a" (lazy "'a stream")
  5320 
  5321 * New command 'fixrec' for defining recursive functions with pattern
  5322 matching; defining multiple functions with mutual recursion is also
  5323 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5324 sinr, or any data constructor defined by the domain package. The given
  5325 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5326 syntax and examples.
  5327 
  5328 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5329 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5330 but the proof obligation additionally includes an admissibility
  5331 requirement. The packages generate instances of class cpo or pcpo,
  5332 with continuity and strictness theorems for Rep and Abs.
  5333 
  5334 * HOLCF: Many theorems have been renamed according to a more standard naming
  5335 scheme (INCOMPATIBILITY):
  5336 
  5337   foo_inject:  "foo$x = foo$y ==> x = y"
  5338   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5339   foo_less:    "(foo$x << foo$y) = (x << y)"
  5340   foo_strict:  "foo$UU = UU"
  5341   foo_defined: "... ==> foo$x ~= UU"
  5342   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5343 
  5344 
  5345 *** ZF ***
  5346 
  5347 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5348 including the First Isomorphism Theorem (on quotienting by the kernel
  5349 of a homomorphism).
  5350 
  5351 * ZF/Simplifier: install second copy of type solver that actually
  5352 makes use of TC rules declared to Isar proof contexts (or locales);
  5353 the old version is still required for ML proof scripts.
  5354 
  5355 
  5356 *** Cube ***
  5357 
  5358 * Converted to Isar theory format; use locales instead of axiomatic
  5359 theories.
  5360 
  5361 
  5362 *** ML ***
  5363 
  5364 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5365 for ||>, ||>>, |>>,
  5366 
  5367 * Pure/library.ML no longer defines its own option datatype, but uses
  5368 that of the SML basis, which has constructors NONE and SOME instead of
  5369 None and Some, as well as exception Option.Option instead of OPTION.
  5370 The functions the, if_none, is_some, is_none have been adapted
  5371 accordingly, while Option.map replaces apsome.
  5372 
  5373 * Pure/library.ML: the exception LIST has been given up in favour of
  5374 the standard exceptions Empty and Subscript, as well as
  5375 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5376 superceded by the standard hd and tl functions etc.
  5377 
  5378 A number of basic list functions are no longer exported to the ML
  5379 toplevel, as they are variants of predefined functions.  The following
  5380 suggests how one can translate existing code:
  5381 
  5382     rev_append xs ys = List.revAppend (xs, ys)
  5383     nth_elem (i, xs) = List.nth (xs, i)
  5384     last_elem xs = List.last xs
  5385     flat xss = List.concat xss
  5386     seq fs = List.app fs
  5387     partition P xs = List.partition P xs
  5388     mapfilter f xs = List.mapPartial f xs
  5389 
  5390 * Pure/library.ML: several combinators for linear functional
  5391 transformations, notably reverse application and composition:
  5392 
  5393   x |> f                f #> g
  5394   (x, y) |-> f          f #-> g
  5395 
  5396 * Pure/library.ML: introduced/changed precedence of infix operators:
  5397 
  5398   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5399   infix 2 ?;
  5400   infix 3 o oo ooo oooo;
  5401   infix 4 ~~ upto downto;
  5402 
  5403 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5404 infix operators.
  5405 
  5406 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5407 fold_map support linear functional transformations and nesting.  For
  5408 example:
  5409 
  5410   fold f [x1, ..., xN] y =
  5411     y |> f x1 |> ... |> f xN
  5412 
  5413   (fold o fold) f [xs1, ..., xsN] y =
  5414     y |> fold f xs1 |> ... |> fold f xsN
  5415 
  5416   fold f [x1, ..., xN] =
  5417     f x1 #> ... #> f xN
  5418 
  5419   (fold o fold) f [xs1, ..., xsN] =
  5420     fold f xs1 #> ... #> fold f xsN
  5421 
  5422 * Pure/library.ML: the following selectors on type 'a option are
  5423 available:
  5424 
  5425   the:               'a option -> 'a  (*partial*)
  5426   these:             'a option -> 'a  where 'a = 'b list
  5427   the_default: 'a -> 'a option -> 'a
  5428   the_list:          'a option -> 'a list
  5429 
  5430 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5431 basic operations for association lists, following natural argument
  5432 order; moreover the explicit equality predicate passed here avoids
  5433 potentially expensive polymorphic runtime equality checks.
  5434 The old functions may be expressed as follows:
  5435 
  5436   assoc = uncurry (AList.lookup (op =))
  5437   assocs = these oo AList.lookup (op =)
  5438   overwrite = uncurry (AList.update (op =)) o swap
  5439 
  5440 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5441 
  5442   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5443   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5444 
  5445 replacing make_keylist and keyfilter (occassionally used)
  5446 Naive rewrites:
  5447 
  5448   make_keylist = AList.make
  5449   keyfilter = AList.find (op =)
  5450 
  5451 * eq_fst and eq_snd now take explicit equality parameter, thus
  5452   avoiding eqtypes. Naive rewrites:
  5453 
  5454     eq_fst = eq_fst (op =)
  5455     eq_snd = eq_snd (op =)
  5456 
  5457 * Removed deprecated apl and apr (rarely used).
  5458   Naive rewrites:
  5459 
  5460     apl (n, op) =>>= curry op n
  5461     apr (op, m) =>>= fn n => op (n, m)
  5462 
  5463 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5464 provides a reasonably efficient light-weight implementation of sets as
  5465 lists.
  5466 
  5467 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5468 few new operations; existing lookup and update are now curried to
  5469 follow natural argument order (for use with fold etc.);
  5470 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5471 
  5472 * Pure/General: output via the Isabelle channels of
  5473 writeln/warning/error etc. is now passed through Output.output, with a
  5474 hook for arbitrary transformations depending on the print_mode
  5475 (cf. Output.add_mode -- the first active mode that provides a output
  5476 function wins).  Already formatted output may be embedded into further
  5477 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5478 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5479 accommodate easy composition of diagnostic messages etc.  Programmers
  5480 rarely need to care about Output.output or Output.raw at all, with
  5481 some notable exceptions: Output.output is required when bypassing the
  5482 standard channels (writeln etc.), or in token translations to produce
  5483 properly formatted results; Output.raw is required when capturing
  5484 already output material that will eventually be presented to the user
  5485 a second time.  For the default print mode, both Output.output and
  5486 Output.raw have no effect.
  5487 
  5488 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5489 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5490 cumulative results are displayed at the end of a batch session.
  5491 
  5492 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5493 replaced by File.platform_path and File.shell_path (with appropriate
  5494 hooks).  This provides a clean interface for unusual systems where the
  5495 internal and external process view of file names are different.
  5496 
  5497 * Pure: more efficient orders for basic syntactic entities: added
  5498 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5499 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5500 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5501 orders now -- potential INCOMPATIBILITY for code that depends on a
  5502 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5503 Library.sort_strings on result).
  5504 
  5505 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5506 fold_types traverse types/terms from left to right, observing natural
  5507 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5508 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5509 
  5510 * Pure: name spaces have been refined, with significant changes of the
  5511 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5512 to extern(_table).  The plain name entry path is superceded by a
  5513 general 'naming' context, which also includes the 'policy' to produce
  5514 a fully qualified name and external accesses of a fully qualified
  5515 name; NameSpace.extend is superceded by context dependent
  5516 Sign.declare_name.  Several theory and proof context operations modify
  5517 the naming context.  Especially note Theory.restore_naming and
  5518 ProofContext.restore_naming to get back to a sane state; note that
  5519 Theory.add_path is no longer sufficient to recover from
  5520 Theory.absolute_path in particular.
  5521 
  5522 * Pure: new flags short_names (default false) and unique_names
  5523 (default true) for controlling output of qualified names.  If
  5524 short_names is set, names are printed unqualified.  If unique_names is
  5525 reset, the name prefix is reduced to the minimum required to achieve
  5526 the original result when interning again, even if there is an overlap
  5527 with earlier declarations.
  5528 
  5529 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5530 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5531 (useful for printing error messages).  INCOMPATIBILITY.
  5532 
  5533 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5534 Theory.theory are now identified, referring to the universal
  5535 Context.theory (see Pure/context.ML).  Actual signature and theory
  5536 content is managed as theory data.  The old code and interfaces were
  5537 spread over many files and structures; the new arrangement introduces
  5538 considerable INCOMPATIBILITY to gain more clarity:
  5539 
  5540   Context -- theory management operations (name, identity, inclusion,
  5541     parents, ancestors, merge, etc.), plus generic theory data;
  5542 
  5543   Sign -- logical signature and syntax operations (declaring consts,
  5544     types, etc.), plus certify/read for common entities;
  5545 
  5546   Theory -- logical theory operations (stating axioms, definitions,
  5547     oracles), plus a copy of logical signature operations (consts,
  5548     types, etc.); also a few basic management operations (Theory.copy,
  5549     Theory.merge, etc.)
  5550 
  5551 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5552 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5553 for convenience -- they merely return the theory.
  5554 
  5555 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5556 
  5557 * Pure: the Isar proof context type is already defined early in Pure
  5558 as Context.proof (note that ProofContext.context and Proof.context are
  5559 aliases, where the latter is the preferred name).  This enables other
  5560 Isabelle components to refer to that type even before Isar is present.
  5561 
  5562 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5563 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5564 any of these kinds.  For example, Sign.intern typeK is now
  5565 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5566 Theory.hide_types.  Also note that former
  5567 Theory.hide_classes/types/consts are now
  5568 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5569 internalize their arguments!  INCOMPATIBILITY.
  5570 
  5571 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5572 datatype thmref (with constructors Name and NameSelection) instead of
  5573 plain string -- INCOMPATIBILITY;
  5574 
  5575 * Pure: cases produced by proof methods specify options, where NONE
  5576 means to remove case bindings -- INCOMPATIBILITY in
  5577 (RAW_)METHOD_CASES.
  5578 
  5579 * Pure: the following operations retrieve axioms or theorems from a
  5580 theory node or theory hierarchy, respectively:
  5581 
  5582   Theory.axioms_of: theory -> (string * term) list
  5583   Theory.all_axioms_of: theory -> (string * term) list
  5584   PureThy.thms_of: theory -> (string * thm) list
  5585   PureThy.all_thms_of: theory -> (string * thm) list
  5586 
  5587 * Pure: print_tac now outputs the goal through the trace channel.
  5588 
  5589 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5590 Reference Toplevel.debug (default false) controls detailed printing
  5591 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5592 controls execution profiling -- set to 1 for time and 2 for space
  5593 (both increase the runtime).
  5594 
  5595 * Isar session: The initial use of ROOT.ML is now always timed,
  5596 i.e. the log will show the actual process times, in contrast to the
  5597 elapsed wall-clock time that the outer shell wrapper produces.
  5598 
  5599 * Simplifier: improved handling of bound variables (nameless
  5600 representation, avoid allocating new strings).  Simprocs that invoke
  5601 the Simplifier recursively should use Simplifier.inherit_bounds to
  5602 avoid local name clashes.  Failure to do so produces warnings
  5603 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5604 for further details.
  5605 
  5606 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5607 bindings for all theorems stored within a given theory; this may help
  5608 in porting non-Isar theories to Isar ones, while keeping ML proof
  5609 scripts for the time being.
  5610 
  5611 * ML operator HTML.with_charset specifies the charset begin used for
  5612 generated HTML files.  For example:
  5613 
  5614   HTML.with_charset "utf-8" use_thy "Hebrew";
  5615   HTML.with_charset "utf-8" use_thy "Chinese";
  5616 
  5617 
  5618 *** System ***
  5619 
  5620 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5621 isabelle, isatool etc.).
  5622 
  5623 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5624 isatool doc, isatool mkdir, display_drafts etc.).
  5625 
  5626 * isatool usedir: option -f allows specification of the ML file to be
  5627 used by Isabelle; default is ROOT.ML.
  5628 
  5629 * New isatool version outputs the version identifier of the Isabelle
  5630 distribution being used.
  5631 
  5632 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5633 (containing Boolean satisfiability problems) into Isabelle/HOL
  5634 theories.
  5635 
  5636 
  5637 
  5638 New in Isabelle2004 (April 2004)
  5639 --------------------------------
  5640 
  5641 *** General ***
  5642 
  5643 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5644   Replaces linorder.ML.
  5645 
  5646 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5647   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5648   (\<a>...\<z>), are now considered normal letters, and can therefore
  5649   be used anywhere where an ASCII letter (a...zA...Z) has until
  5650   now. COMPATIBILITY: This obviously changes the parsing of some
  5651   terms, especially where a symbol has been used as a binder, say
  5652   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5653   as an identifier.  Fix it by inserting a space around former
  5654   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5655   existing theory and ML files.
  5656 
  5657 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5658 
  5659 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5660   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5661   a normal (but invisible) letter. For multiple letter subscripts repeat
  5662   \<^isub> like this: x\<^isub>1\<^isub>2.
  5663 
  5664 * Pure: There are now sub-/superscripts that can span more than one
  5665   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5666   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5667   superscript. The new control characters are not identifier parts.
  5668 
  5669 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5670   content of "..." to the latex file instead of \isacntrl... . The "..."
  5671   may consist of any printable characters excluding the end bracket >.
  5672 
  5673 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5674   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5675   declare constants "final", which prevents their being given a definition
  5676   later.  It is useful for constants whose behaviour is fixed axiomatically
  5677   rather than definitionally, such as the meta-logic connectives.
  5678 
  5679 * Pure: 'instance' now handles general arities with general sorts
  5680   (i.e. intersections of classes),
  5681 
  5682 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5683   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5684   It can be changed to alter the colors/layout of generated pages.
  5685 
  5686 
  5687 *** Isar ***
  5688 
  5689 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5690   cut_tac, subgoal_tac and thin_tac:
  5691   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5692     locales are no longer forced to write Isar proof scripts.
  5693     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5694     emulations.
  5695   - INCOMPATIBILITY: names of variables to be instantiated may no
  5696     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5697     This is consistent with the instantiation attribute "where".
  5698 
  5699 * Attributes "where" and "of":
  5700   - Now take type variables of instantiated theorem into account when reading
  5701     the instantiation string.  This fixes a bug that caused instantiated
  5702     theorems to have too special types in some circumstances.
  5703   - "where" permits explicit instantiations of type variables.
  5704 
  5705 * Calculation commands "moreover" and "also" no longer interfere with
  5706   current facts ("this"), admitting arbitrary combinations with "then"
  5707   and derived forms.
  5708 
  5709 * Locales:
  5710   - Goal statements involving the context element "includes" no longer
  5711     generate theorems with internal delta predicates (those ending on
  5712     "_axioms") in the premise.
  5713     Resolve particular premise with <locale>.intro to obtain old form.
  5714   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5715     specification and "includes" elements in goal statement.
  5716   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5717     [intro?] and [elim?] (respectively) by default.
  5718   - Experimental command for instantiation of locales in proof contexts:
  5719         instantiate <label>[<attrs>]: <loc>
  5720     Instantiates locale <loc> and adds all its theorems to the current context
  5721     taking into account their attributes.  Label and attrs are optional
  5722     modifiers, like in theorem declarations.  If present, names of
  5723     instantiated theorems are qualified with <label>, and the attributes
  5724     <attrs> are applied after any attributes these theorems might have already.
  5725       If the locale has assumptions, a chained fact of the form
  5726     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5727     are derived.  The command does not support old-style locales declared
  5728     with "locale (open)".
  5729       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5730 
  5731 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5732   (Isar) contexts.
  5733 
  5734 
  5735 *** HOL ***
  5736 
  5737 * Proof import: new image HOL4 contains the imported library from
  5738   the HOL4 system with about 2500 theorems. It is imported by
  5739   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5740   can be used like any other Isabelle image.  See
  5741   HOL/Import/HOL/README for more information.
  5742 
  5743 * Simplifier:
  5744   - Much improved handling of linear and partial orders.
  5745     Reasoners for linear and partial orders are set up for type classes
  5746     "linorder" and "order" respectively, and are added to the default simpset
  5747     as solvers.  This means that the simplifier can build transitivity chains
  5748     to solve goals from the assumptions.
  5749   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5750     of blast or auto after simplification become unnecessary because the goal
  5751     is solved by simplification already.
  5752 
  5753 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5754     all proved in axiomatic type classes for semirings, rings and fields.
  5755 
  5756 * Numerics:
  5757   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5758     now formalized using the Ring_and_Field theory mentioned above.
  5759   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5760     than before, because now they are set up once in a generic manner.
  5761   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5762     Look for the general versions in Ring_and_Field (and Power if they concern
  5763     exponentiation).
  5764 
  5765 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5766 
  5767 * Records:
  5768   - Record types are now by default printed with their type abbreviation
  5769     instead of the list of all field types. This can be configured via
  5770     the reference "print_record_type_abbr".
  5771   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5772     (not enabled by default).
  5773   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5774     EX x. x = sel r to True (not enabled by default).
  5775   - Tactic "record_split_simp_tac" to split and simplify records added.
  5776 
  5777 * 'specification' command added, allowing for definition by
  5778   specification.  There is also an 'ax_specification' command that
  5779   introduces the new constants axiomatically.
  5780 
  5781 * arith(_tac) is now able to generate counterexamples for reals as well.
  5782 
  5783 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5784 
  5785 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5786   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5787 
  5788 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5789   matrix theory to linear programming.
  5790 
  5791 * Unions and Intersections:
  5792   The latex output syntax of UN and INT has been changed
  5793   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5794   i.e. the index formulae has become a subscript.
  5795   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5796 
  5797 * Unions and Intersections over Intervals:
  5798   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5799   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5800   like in normal math, and corresponding versions for < and for intersection.
  5801 
  5802 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5803   lexicographic dictonary ordering has been added as "lexord".
  5804 
  5805 * ML: the legacy theory structures Int and List have been removed. They had
  5806   conflicted with ML Basis Library structures having the same names.
  5807 
  5808 * 'refute' command added to search for (finite) countermodels.  Only works
  5809   for a fragment of HOL.  The installation of an external SAT solver is
  5810   highly recommended.  See "HOL/Refute.thy" for details.
  5811 
  5812 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5813   formulae under an assignment of free variables to random values.
  5814   In contrast to 'refute', it can deal with inductive datatypes,
  5815   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5816   for examples.
  5817 
  5818 
  5819 *** HOLCF ***
  5820 
  5821 * Streams now come with concatenation and are part of the HOLCF image
  5822 
  5823 
  5824 
  5825 New in Isabelle2003 (May 2003)
  5826 ------------------------------
  5827 
  5828 *** General ***
  5829 
  5830 * Provers/simplifier:
  5831 
  5832   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5833     Assumptions are now subject to complete mutual simplification,
  5834     not just from left to right. The simplifier now preserves
  5835     the order of assumptions.
  5836 
  5837     Potential INCOMPATIBILITY:
  5838 
  5839     -- simp sometimes diverges where the old version did
  5840        not, e.g. invoking simp on the goal
  5841 
  5842         [| P (f x); y = x; f x = f y |] ==> Q
  5843 
  5844        now gives rise to the infinite reduction sequence
  5845 
  5846         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5847 
  5848        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5849        kind of problem.
  5850 
  5851     -- Tactics combining classical reasoner and simplification (such as auto)
  5852        are also affected by this change, because many of them rely on
  5853        simp. They may sometimes diverge as well or yield a different numbers
  5854        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5855        in case of problems. Sometimes subsequent calls to the classical
  5856        reasoner will fail because a preceeding call to the simplifier too
  5857        eagerly simplified the goal, e.g. deleted redundant premises.
  5858 
  5859   - The simplifier trace now shows the names of the applied rewrite rules
  5860 
  5861   - You can limit the number of recursive invocations of the simplifier
  5862     during conditional rewriting (where the simplifie tries to solve the
  5863     conditions before applying the rewrite rule):
  5864     ML "simp_depth_limit := n"
  5865     where n is an integer. Thus you can force termination where previously
  5866     the simplifier would diverge.
  5867 
  5868   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5869 
  5870   - No longer aborts on failed congruence proof.  Instead, the
  5871     congruence is ignored.
  5872 
  5873 * Pure: New generic framework for extracting programs from constructive
  5874   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5875   as HOL/Extraction for some case studies.
  5876 
  5877 * Pure: The main goal of the proof state is no longer shown by default, only
  5878 the subgoals. This behaviour is controlled by a new flag.
  5879    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5880 (ML: Proof.show_main_goal).
  5881 
  5882 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5883 rules whose conclusion matches subgoal 1:
  5884       PG menu: Isabelle/Isar -> Show me -> matching rules
  5885 The rules are ordered by how closely they match the subgoal.
  5886 In particular, rules that solve a subgoal outright are displayed first
  5887 (or rather last, the way they are printed).
  5888 (ML: ProofGeneral.print_intros())
  5889 
  5890 * Pure: New flag trace_unify_fail causes unification to print
  5891 diagnostic information (PG: in trace buffer) when it fails. This is
  5892 useful for figuring out why single step proofs like rule, erule or
  5893 assumption failed.
  5894 
  5895 * Pure: Locale specifications now produce predicate definitions
  5896 according to the body of text (covering assumptions modulo local
  5897 definitions); predicate "loc_axioms" covers newly introduced text,
  5898 while "loc" is cumulative wrt. all included locale expressions; the
  5899 latter view is presented only on export into the global theory
  5900 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5901 on the old view without predicates;
  5902 
  5903 * Pure: predefined locales "var" and "struct" are useful for sharing
  5904 parameters (as in CASL, for example); just specify something like
  5905 ``var x + var y + struct M'' as import;
  5906 
  5907 * Pure: improved thms_containing: proper indexing of facts instead of
  5908 raw theorems; check validity of results wrt. current name space;
  5909 include local facts of proof configuration (also covers active
  5910 locales), cover fixed variables in index; may use "_" in term
  5911 specification; an optional limit for the number of printed facts may
  5912 be given (the default is 40);
  5913 
  5914 * Pure: disallow duplicate fact bindings within new-style theory files
  5915 (batch-mode only);
  5916 
  5917 * Provers: improved induct method: assumptions introduced by case
  5918 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5919 the goal statement); "foo" still refers to all facts collectively;
  5920 
  5921 * Provers: the function blast.overloaded has been removed: all constants
  5922 are regarded as potentially overloaded, which improves robustness in exchange
  5923 for slight decrease in efficiency;
  5924 
  5925 * Provers/linorder: New generic prover for transitivity reasoning over
  5926 linear orders.  Note: this prover is not efficient!
  5927 
  5928 * Isar: preview of problems to finish 'show' now produce an error
  5929 rather than just a warning (in interactive mode);
  5930 
  5931 
  5932 *** HOL ***
  5933 
  5934 * arith(_tac)
  5935 
  5936  - Produces a counter example if it cannot prove a goal.
  5937    Note that the counter example may be spurious if the goal is not a formula
  5938    of quantifier-free linear arithmetic.
  5939    In ProofGeneral the counter example appears in the trace buffer.
  5940 
  5941  - Knows about div k and mod k where k is a numeral of type nat or int.
  5942 
  5943  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5944    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5945    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5946 
  5947 * simp's arithmetic capabilities have been enhanced a bit: it now
  5948 takes ~= in premises into account (by performing a case split);
  5949 
  5950 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5951 are distributed over a sum of terms;
  5952 
  5953 * New tactic "trans_tac" and method "trans" instantiate
  5954 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5955 "<=", "<" and "=").
  5956 
  5957 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5958 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5959 
  5960 * 'typedef' command has new option "open" to suppress the set
  5961 definition;
  5962 
  5963 * functions Min and Max on finite sets have been introduced (theory
  5964 Finite_Set);
  5965 
  5966 * attribute [symmetric] now works for relations as well; it turns
  5967 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5968 
  5969 * induct over a !!-quantified statement (say !!x1..xn):
  5970   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5971 
  5972 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5973 %x. None. Warning: empty_def now refers to the previously hidden definition
  5974 of the empty set.
  5975 
  5976 * Algebra: formalization of classical algebra.  Intended as base for
  5977 any algebraic development in Isabelle.  Currently covers group theory
  5978 (up to Sylow's theorem) and ring theory (Universal Property of
  5979 Univariate Polynomials).  Contributions welcome;
  5980 
  5981 * GroupTheory: deleted, since its material has been moved to Algebra;
  5982 
  5983 * Complex: new directory of the complex numbers with numeric constants,
  5984 nonstandard complex numbers, and some complex analysis, standard and
  5985 nonstandard (Jacques Fleuriot);
  5986 
  5987 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5988 
  5989 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5990 Fleuriot);
  5991 
  5992 * Real/HahnBanach: updated and adapted to locales;
  5993 
  5994 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5995 Gray and Kramer);
  5996 
  5997 * UNITY: added the Meier-Sanders theory of progress sets;
  5998 
  5999 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6000 as abstract algorithms, instantiated to the JVM;
  6001 
  6002 * Bali: Java source language formalization. Type system, operational
  6003 semantics, axiomatic semantics. Supported language features:
  6004 classes, interfaces, objects,virtual methods, static methods,
  6005 static/instance fields, arrays, access modifiers, definite
  6006 assignment, exceptions.
  6007 
  6008 
  6009 *** ZF ***
  6010 
  6011 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6012 universe, etc.);
  6013 
  6014 * Main ZF: virtually all theories converted to new-style format;
  6015 
  6016 
  6017 *** ML ***
  6018 
  6019 * Pure: Tactic.prove provides sane interface for internal proofs;
  6020 omits the infamous "standard" operation, so this is more appropriate
  6021 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6022 
  6023 * Pure: improved error reporting of simprocs;
  6024 
  6025 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6026 up simprocs;
  6027 
  6028 
  6029 *** Document preparation ***
  6030 
  6031 * uses \par instead of \\ for line breaks in theory text. This may
  6032 shift some page breaks in large documents. To get the old behaviour
  6033 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6034 
  6035 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6036 other packages
  6037 
  6038 * \<euro> now needs package babel/greek instead of marvosym (which
  6039 broke \Rightarrow)
  6040 
  6041 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6042 textcomp package)
  6043 
  6044 
  6045 
  6046 New in Isabelle2002 (March 2002)
  6047 --------------------------------
  6048 
  6049 *** Document preparation ***
  6050 
  6051 * greatly simplified document preparation setup, including more
  6052 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6053 instructive isatool mkdir; users should basically be able to get
  6054 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6055 users may run a separate document processing stage manually like this:
  6056 "isatool usedir -D output HOL Test && isatool document Test/output";
  6057 
  6058 * theory dependency graph may now be incorporated into documents;
  6059 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6060 with \includegraphics of LaTeX;
  6061 
  6062 * proper spacing of consecutive markup elements, especially text
  6063 blocks after section headings;
  6064 
  6065 * support bold style (for single symbols only), input syntax is like
  6066 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6067 
  6068 * \<bullet> is now output as bold \cdot by default, which looks much
  6069 better in printed text;
  6070 
  6071 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6072 note that these symbols are currently unavailable in Proof General /
  6073 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6074 
  6075 * isatool latex no longer depends on changed TEXINPUTS, instead
  6076 isatool document copies the Isabelle style files to the target
  6077 location;
  6078 
  6079 
  6080 *** Isar ***
  6081 
  6082 * Pure/Provers: improved proof by cases and induction;
  6083   - 'case' command admits impromptu naming of parameters (such as
  6084     "case (Suc n)");
  6085   - 'induct' method divinates rule instantiation from the inductive
  6086     claim; no longer requires excessive ?P bindings for proper
  6087     instantiation of cases;
  6088   - 'induct' method properly enumerates all possibilities of set/type
  6089     rules; as a consequence facts may be also passed through *type*
  6090     rules without further ado;
  6091   - 'induct' method now derives symbolic cases from the *rulified*
  6092     rule (before it used to rulify cases stemming from the internal
  6093     atomized version); this means that the context of a non-atomic
  6094     statement becomes is included in the hypothesis, avoiding the
  6095     slightly cumbersome show "PROP ?case" form;
  6096   - 'induct' may now use elim-style induction rules without chaining
  6097     facts, using ``missing'' premises from the goal state; this allows
  6098     rules stemming from inductive sets to be applied in unstructured
  6099     scripts, while still benefitting from proper handling of non-atomic
  6100     statements; NB: major inductive premises need to be put first, all
  6101     the rest of the goal is passed through the induction;
  6102   - 'induct' proper support for mutual induction involving non-atomic
  6103     rule statements (uses the new concept of simultaneous goals, see
  6104     below);
  6105   - append all possible rule selections, but only use the first
  6106     success (no backtracking);
  6107   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6108   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6109   - added 'print_induct_rules' (covered by help item in recent Proof
  6110     General versions);
  6111   - moved induct/cases attributes to Pure, methods to Provers;
  6112   - generic method setup instantiated for FOL and HOL;
  6113 
  6114 * Pure: support multiple simultaneous goal statements, for example
  6115 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6116 meta-level mechanism, this acts as if several individual goals had
  6117 been stated separately; in particular common proof methods need to be
  6118 repeated in order to cover all claims; note that a single elimination
  6119 step is *not* sufficient to establish the two conjunctions, so this
  6120 fails:
  6121 
  6122   assume "A & B" then have A and B ..   (*".." fails*)
  6123 
  6124 better use "obtain" in situations as above; alternative refer to
  6125 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6126 
  6127 * Pure: proper integration with ``locales''; unlike the original
  6128 version by Florian Kammller, Isar locales package high-level proof
  6129 contexts rather than raw logical ones (e.g. we admit to include
  6130 attributes everywhere); operations on locales include merge and
  6131 rename; support for implicit arguments (``structures''); simultaneous
  6132 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6133 some examples;
  6134 
  6135 * Pure: the following commands have been ``localized'', supporting a
  6136 target locale specification "(in name)": 'lemma', 'theorem',
  6137 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6138 stored both within the locale and at the theory level (exported and
  6139 qualified by the locale name);
  6140 
  6141 * Pure: theory goals may now be specified in ``long'' form, with
  6142 ad-hoc contexts consisting of arbitrary locale elements. for example
  6143 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6144 definitions may be given, too); the result is a meta-level rule with
  6145 the context elements being discharged in the obvious way;
  6146 
  6147 * Pure: new proof command 'using' allows to augment currently used
  6148 facts after a goal statement ('using' is syntactically analogous to
  6149 'apply', but acts on the goal's facts only); this allows chained facts
  6150 to be separated into parts given before and after a claim, as in
  6151 ``from a and b have C using d and e <proof>'';
  6152 
  6153 * Pure: renamed "antecedent" case to "rule_context";
  6154 
  6155 * Pure: new 'judgment' command records explicit information about the
  6156 object-logic embedding (used by several tools internally); no longer
  6157 use hard-wired "Trueprop";
  6158 
  6159 * Pure: added 'corollary' command;
  6160 
  6161 * Pure: fixed 'token_translation' command;
  6162 
  6163 * Pure: removed obsolete 'exported' attribute;
  6164 
  6165 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6166 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6167 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6168 
  6169 * Pure: method 'atomize' presents local goal premises as object-level
  6170 statements (atomic meta-level propositions); setup controlled via
  6171 rewrite rules declarations of 'atomize' attribute; example
  6172 application: 'induct' method with proper rule statements in improper
  6173 proof *scripts*;
  6174 
  6175 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6176 now consider the syntactic context of assumptions, giving a better
  6177 chance to get type-inference of the arguments right (this is
  6178 especially important for locales);
  6179 
  6180 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6181 mode;
  6182 
  6183 * Pure/obtain: the formal conclusion "thesis", being marked as
  6184 ``internal'', may no longer be reference directly in the text;
  6185 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6186 situations;
  6187 
  6188 * Pure: generic 'sym' attribute which declares a rule both as pure
  6189 'elim?' and for the 'symmetric' operation;
  6190 
  6191 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6192 text; the fixed correlation with particular command syntax has been
  6193 discontinued;
  6194 
  6195 * Pure: new method 'rules' is particularly well-suited for proof
  6196 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6197 but often produces more compact proof terms with less detours;
  6198 
  6199 * Pure/Provers/classical: simplified integration with pure rule
  6200 attributes and methods; the classical "intro?/elim?/dest?"
  6201 declarations coincide with the pure ones; the "rule" method no longer
  6202 includes classically swapped intros; "intro" and "elim" methods no
  6203 longer pick rules from the context; also got rid of ML declarations
  6204 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6205 INCOMPATIBILITY;
  6206 
  6207 * Provers/classical: attribute 'swapped' produces classical inversions
  6208 of introduction rules;
  6209 
  6210 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6211 rules instead of full simplifier context; 'iff' attribute handles
  6212 conditional rules;
  6213 
  6214 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6215 
  6216 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6217 "(permissive)" option to recover old behavior;
  6218 
  6219 * HOL: 'inductive' no longer features separate (collective) attributes
  6220 for 'intros' (was found too confusing);
  6221 
  6222 * HOL: properly declared induction rules less_induct and
  6223 wf_induct_rule;
  6224 
  6225 
  6226 *** HOL ***
  6227 
  6228 * HOL: moved over to sane numeral syntax; the new policy is as
  6229 follows:
  6230 
  6231   - 0 and 1 are polymorphic constants, which are defined on any
  6232   numeric type (nat, int, real etc.);