NEWS
author wenzelm
Sun, 10 Jul 2011 20:59:04 +0200
changeset 44613 70072780e095
parent 44580 717e96cf9527
child 44614 8786e36b8142
permissions -rw-r--r--
inner syntax supports inlined YXML according to Term_XML (particularly useful for producing text under program control);
tuned signature;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) has been discontinued.
    26 Note that the path element ~~ may be used to reference theories in the
    27 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
    28 INCOMPATIBILITY.
    29 
    30 * Various optional external tools are referenced more robustly and
    31 uniformly by explicit Isabelle settings as follows:
    32 
    33   ISABELLE_CSDP   (formerly CSDP_EXE)
    34   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    35   ISABELLE_OCAML  (formerly EXEC_OCAML)
    36   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    37   ISABELLE_YAP    (formerly EXEC_YAP)
    38 
    39 Note that automated detection from the file-system or search path has
    40 been discontinued.  INCOMPATIBILITY.
    41 
    42 * Name space: former unsynchronized references are now proper
    43 configuration options, with more conventional names:
    44 
    45   long_names   ~> names_long
    46   short_names  ~> names_short
    47   unique_names ~> names_unique
    48 
    49 Minor INCOMPATIBILITY, need to declare options in context like this:
    50 
    51   declare [[names_unique = false]]
    52 
    53 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    54 that the result needs to be unique, which means fact specifications
    55 may have to be refined after enriching a proof context.
    56 
    57 * Isabelle/Isar reference manual provides more formal references in
    58 syntax diagrams.
    59 
    60 
    61 *** HOL ***
    62 
    63 * Finite_Set.thy: more coherent development of fold_set locales:
    64 
    65     locale fun_left_comm ~> locale comp_fun_commute
    66     locale fun_left_comm_idem ~> locale comp_fun_idem
    67     
    68 Both use point-free characterisation; interpretation proofs may need adjustment.
    69 INCOMPATIBILITY.
    70 
    71 * Code generation:
    72   - theory Library/Code_Char_ord provides native ordering of characters
    73     in the target language.
    74     
    75 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    76 
    77 * Nitpick:
    78   - Added "need" and "total_consts" options.
    79   - Reintroduced "show_skolems" option by popular demand.
    80   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    81     INCOMPATIBILITY.
    82 
    83 * Sledgehammer:
    84   - sledgehammer available_provers ~> sledgehammer supported_provers.
    85     INCOMPATIBILITY.
    86   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    87     TPTP problems (TFF).
    88   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
    89     and "max_new_mono_instances" options.
    90   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
    91     Proof General menu item. INCOMPATIBILITY.
    92 
    93 * Metis:
    94   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
    95   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
    96 
    97 * "try":
    98   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
    99     options. INCOMPATIBILITY.
   100   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   101     "sledgehammer", "quickcheck", and "nitpick".
   102 
   103 * Quickcheck:
   104   - Added "eval" option to evaluate terms for the found counterexample
   105     (currently only supported by the default (exhaustive) tester)
   106   - Added post-processing of terms to obtain readable counterexamples
   107     (currently only supported by the default (exhaustive) tester)
   108   - New counterexample generator quickcheck[narrowing] enables
   109     narrowing-based testing.
   110     It requires that the Glasgow Haskell compiler is installed and
   111     its location is known to Isabelle with the environment variable
   112     ISABELLE_GHC.
   113 
   114 * Function package: discontinued option "tailrec".
   115 INCOMPATIBILITY. Use partial_function instead.
   116 
   117 * HOL-Probability:
   118   - Caratheodory's extension lemma is now proved for ring_of_sets.
   119   - Infinite products of probability measures are now available.
   120   - Use extended reals instead of positive extended reals.
   121     INCOMPATIBILITY.
   122 
   123 
   124 *** Document preparation ***
   125 
   126 * Discontinued special treatment of hard tabulators, which are better
   127 avoided in the first place.  Implicit tab-width is 1.
   128 
   129 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   130 isar-ref manual.
   131 
   132 * Antiquotation @{value} evaluates the given term and presents its result.
   133 
   134 * Localized \isabellestyle switch can be used within blocks or groups
   135 like this:
   136 
   137   \isabellestyle{it}  %preferred default
   138   {\isabellestylett @{text "typewriter stuff"}}
   139 
   140 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   141 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   142 
   143 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   144 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   145 
   146 
   147 *** ML ***
   148 
   149 * The inner syntax of sort/type/term/prop supports inlined YXML
   150 representations within quoted string tokens.  By encoding logical
   151 entities via Term_XML (in ML or Scala) concrete syntax can be
   152 bypassed, which is particularly useful for producing bits of text
   153 under external program control.
   154 
   155 * Antiquotations for ML and document preparation are managed as theory
   156 data, which requires explicit setup.
   157 
   158 * Isabelle_Process.is_active allows tools to check if the official
   159 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   160 (better known as Proof General).
   161 
   162 * Structure Proof_Context follows standard naming scheme.  Old
   163 ProofContext is still available for some time as legacy alias.
   164 
   165 * Structure Timing provides various operations for timing; supersedes
   166 former start_timing/end_timing etc.
   167 
   168 * Path.print is the official way to show file-system paths to users
   169 (including quotes etc.).
   170 
   171 * Inner syntax: identifiers in parse trees of generic categories
   172 "logic", "aprop", "idt" etc. carry position information (disguised as
   173 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   174 translations that choke on unexpected type constraints.  Positions can
   175 be stripped in ML translations via Syntax.strip_positions /
   176 Syntax.strip_positions_ast, or via the syntax constant
   177 "_strip_positions" within parse trees.  As last resort, positions can
   178 be disabled via the configuration option Syntax.positions, which is
   179 called "syntax_positions" in Isar attribute syntax.
   180 
   181 * Discontinued special status of various ML structures that contribute
   182 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   183 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   184 refer directly to Ast.Constant, Lexicon.is_identifier,
   185 Syntax_Trans.mk_binder_tr etc.
   186 
   187 * Typed print translation: discontinued show_sorts argument, which is
   188 already available via context of "advanced" translation.
   189 
   190 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   191 goal states; body tactic needs to address all subgoals uniformly.
   192 
   193 * Slightly more special eq_list/eq_set, with shortcut involving
   194 pointer equality (assumes that eq relation is reflexive).
   195 
   196 * Classical tactics use proper Proof.context instead of historic types
   197 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   198 operate directly on Proof.context.  Raw type claset retains its use as
   199 snapshot of the classical context, which can be recovered via
   200 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   201 INCOMPATIBILITY, classical tactics and derived proof methods require
   202 proper Proof.context.
   203 
   204 
   205 
   206 New in Isabelle2011 (January 2011)
   207 ----------------------------------
   208 
   209 *** General ***
   210 
   211 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   212 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   213 useful tooltips and hyperlinks produced from its static analysis.  The
   214 bundled component provides an executable Isabelle tool that can be run
   215 like this:
   216 
   217   Isabelle2011/bin/isabelle jedit
   218 
   219 * Significantly improved Isabelle/Isar implementation manual.
   220 
   221 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   222 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   223 while the default heap location within that directory lacks that extra
   224 suffix.  This isolates multiple Isabelle installations from each
   225 other, avoiding problems with old settings in new versions.
   226 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   227 
   228 * Source files are always encoded as UTF-8, instead of old-fashioned
   229 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   230 the following package declarations:
   231 
   232   \usepackage[utf8]{inputenc}
   233   \usepackage{textcomp}
   234 
   235 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   236 a Unicode character is treated as a single symbol, not a sequence of
   237 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   238 contain symbols without further backslash escapes, Unicode can now be
   239 used here as well.  Recall that Symbol.explode in ML provides a
   240 consistent view on symbols, while raw explode (or String.explode)
   241 merely give a byte-oriented representation.
   242 
   243 * Theory loader: source files are primarily located via the master
   244 directory of each theory node (where the .thy file itself resides).
   245 The global load path is still partially available as legacy feature.
   246 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   247 explicit paths, relatively to the theory.
   248 
   249 * Special treatment of ML file names has been discontinued.
   250 Historically, optional extensions .ML or .sml were added on demand --
   251 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   252 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   253 
   254 * Various options that affect pretty printing etc. are now properly
   255 handled within the context via configuration options, instead of
   256 unsynchronized references or print modes.  There are both ML Config.T
   257 entities and Isar declaration attributes to access these.
   258 
   259   ML (Config.T)                 Isar (attribute)
   260 
   261   eta_contract                  eta_contract
   262   show_brackets                 show_brackets
   263   show_sorts                    show_sorts
   264   show_types                    show_types
   265   show_question_marks           show_question_marks
   266   show_consts                   show_consts
   267   show_abbrevs                  show_abbrevs
   268 
   269   Syntax.ast_trace              syntax_ast_trace
   270   Syntax.ast_stat               syntax_ast_stat
   271   Syntax.ambiguity_level        syntax_ambiguity_level
   272 
   273   Goal_Display.goals_limit      goals_limit
   274   Goal_Display.show_main_goal   show_main_goal
   275 
   276   Method.rule_trace             rule_trace
   277 
   278   Thy_Output.display            thy_output_display
   279   Thy_Output.quotes             thy_output_quotes
   280   Thy_Output.indent             thy_output_indent
   281   Thy_Output.source             thy_output_source
   282   Thy_Output.break              thy_output_break
   283 
   284 Note that corresponding "..._default" references in ML may only be
   285 changed globally at the ROOT session setup, but *not* within a theory.
   286 The option "show_abbrevs" supersedes the former print mode
   287 "no_abbrevs" with inverted meaning.
   288 
   289 * More systematic naming of some configuration options.
   290 INCOMPATIBILITY.
   291 
   292   trace_simp  ~>  simp_trace
   293   debug_simp  ~>  simp_debug
   294 
   295 * Support for real valued configuration options, using simplistic
   296 floating-point notation that coincides with the inner syntax for
   297 float_token.
   298 
   299 * Support for real valued preferences (with approximative PGIP type):
   300 front-ends need to accept "pgint" values in float notation.
   301 INCOMPATIBILITY.
   302 
   303 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   304 DejaVu Sans.
   305 
   306 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   307 
   308 
   309 *** Pure ***
   310 
   311 * Command 'type_synonym' (with single argument) replaces somewhat
   312 outdated 'types', which is still available as legacy feature for some
   313 time.
   314 
   315 * Command 'nonterminal' (with 'and' separated list of arguments)
   316 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   317 
   318 * Command 'notepad' replaces former 'example_proof' for
   319 experimentation in Isar without any result.  INCOMPATIBILITY.
   320 
   321 * Locale interpretation commands 'interpret' and 'sublocale' accept
   322 lists of equations to map definitions in a locale to appropriate
   323 entities in the context of the interpretation.  The 'interpretation'
   324 command already provided this functionality.
   325 
   326 * Diagnostic command 'print_dependencies' prints the locale instances
   327 that would be activated if the specified expression was interpreted in
   328 the current context.  Variant "print_dependencies!" assumes a context
   329 without interpretations.
   330 
   331 * Diagnostic command 'print_interps' prints interpretations in proofs
   332 in addition to interpretations in theories.
   333 
   334 * Discontinued obsolete 'global' and 'local' commands to manipulate
   335 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   336 Sign.root_path and Sign.local_path may be applied directly where this
   337 feature is still required for historical reasons.
   338 
   339 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   340 'definition' instead.
   341 
   342 * The "prems" fact, which refers to the accidental collection of
   343 foundational premises in the context, is now explicitly marked as
   344 legacy feature and will be discontinued soon.  Consider using "assms"
   345 of the head statement or reference facts by explicit names.
   346 
   347 * Document antiquotations @{class} and @{type} print classes and type
   348 constructors.
   349 
   350 * Document antiquotation @{file} checks file/directory entries within
   351 the local file system.
   352 
   353 
   354 *** HOL ***
   355 
   356 * Coercive subtyping: functions can be declared as coercions and type
   357 inference will add them as necessary upon input of a term.  Theory
   358 Complex_Main declares real :: nat => real and real :: int => real as
   359 coercions. A coercion function f is declared like this:
   360 
   361   declare [[coercion f]]
   362 
   363 To lift coercions through type constructors (e.g. from nat => real to
   364 nat list => real list), map functions can be declared, e.g.
   365 
   366   declare [[coercion_map map]]
   367 
   368 Currently coercion inference is activated only in theories including
   369 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   370 the configuration option "coercion_enabled", e.g. it can be enabled in
   371 other theories like this:
   372 
   373   declare [[coercion_enabled]]
   374 
   375 * Command 'partial_function' provides basic support for recursive
   376 function definitions over complete partial orders.  Concrete instances
   377 are provided for i) the option type, ii) tail recursion on arbitrary
   378 types, and iii) the heap monad of Imperative_HOL.  See
   379 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   380 for examples.
   381 
   382 * Function package: f.psimps rules are no longer implicitly declared
   383 as [simp].  INCOMPATIBILITY.
   384 
   385 * Datatype package: theorems generated for executable equality (class
   386 "eq") carry proper names and are treated as default code equations.
   387 
   388 * Inductive package: now offers command 'inductive_simps' to
   389 automatically derive instantiated and simplified equations for
   390 inductive predicates, similar to 'inductive_cases'.
   391 
   392 * Command 'enriched_type' allows to register properties of the
   393 functorial structure of types.
   394 
   395 * Improved infrastructure for term evaluation using code generator
   396 techniques, in particular static evaluation conversions.
   397 
   398 * Code generator: Scala (2.8 or higher) has been added to the target
   399 languages.
   400 
   401 * Code generator: globbing constant expressions "*" and "Theory.*"
   402 have been replaced by the more idiomatic "_" and "Theory._".
   403 INCOMPATIBILITY.
   404 
   405 * Code generator: export_code without explicit file declaration prints
   406 to standard output.  INCOMPATIBILITY.
   407 
   408 * Code generator: do not print function definitions for case
   409 combinators any longer.
   410 
   411 * Code generator: simplification with rules determined with
   412 src/Tools/Code/code_simp.ML and method "code_simp".
   413 
   414 * Code generator for records: more idiomatic representation of record
   415 types.  Warning: records are not covered by ancient SML code
   416 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   417 rep_datatype declaration helps to succeed then:
   418 
   419   record 'a foo = ...
   420   ...
   421   rep_datatype foo_ext ...
   422 
   423 * Records: logical foundation type for records does not carry a
   424 '_type' suffix any longer (obsolete due to authentic syntax).
   425 INCOMPATIBILITY.
   426 
   427 * Quickcheck now by default uses exhaustive testing instead of random
   428 testing.  Random testing can be invoked by "quickcheck [random]",
   429 exhaustive testing by "quickcheck [exhaustive]".
   430 
   431 * Quickcheck instantiates polymorphic types with small finite
   432 datatypes by default. This enables a simple execution mechanism to
   433 handle quantifiers and function equality over the finite datatypes.
   434 
   435 * Quickcheck random generator has been renamed from "code" to
   436 "random".  INCOMPATIBILITY.
   437 
   438 * Quickcheck now has a configurable time limit which is set to 30
   439 seconds by default. This can be changed by adding [timeout = n] to the
   440 quickcheck command. The time limit for Auto Quickcheck is still set
   441 independently.
   442 
   443 * Quickcheck in locales considers interpretations of that locale for
   444 counter example search.
   445 
   446 * Sledgehammer:
   447   - Added "smt" and "remote_smt" provers based on the "smt" proof
   448     method. See the Sledgehammer manual for details ("isabelle doc
   449     sledgehammer").
   450   - Renamed commands:
   451     sledgehammer atp_info ~> sledgehammer running_provers
   452     sledgehammer atp_kill ~> sledgehammer kill_provers
   453     sledgehammer available_atps ~> sledgehammer available_provers
   454     INCOMPATIBILITY.
   455   - Renamed options:
   456     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   457     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   458     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   459     (and "ms" and "min" are no longer supported)
   460     INCOMPATIBILITY.
   461 
   462 * Nitpick:
   463   - Renamed options:
   464     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   465     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   466     INCOMPATIBILITY.
   467   - Added support for partial quotient types.
   468   - Added local versions of the "Nitpick.register_xxx" functions.
   469   - Added "whack" option.
   470   - Allow registration of quotient types as codatatypes.
   471   - Improved "merge_type_vars" option to merge more types.
   472   - Removed unsound "fast_descrs" option.
   473   - Added custom symmetry breaking for datatypes, making it possible to reach
   474     higher cardinalities.
   475   - Prevent the expansion of too large definitions.
   476 
   477 * Proof methods "metis" and "meson" now have configuration options
   478 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   479 to diagnose these tools. E.g.
   480 
   481     using [[metis_trace = true]]
   482 
   483 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   484 manually as command 'solve_direct'.
   485 
   486 * The default SMT solver Z3 must be enabled explicitly (due to
   487 licensing issues) by setting the environment variable
   488 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   489 commercial applications, the SMT solver CVC3 is provided as fall-back;
   490 changing the SMT solver is done via the configuration option
   491 "smt_solver".
   492 
   493 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   494 i.e. "remote_cvc3" and "remote_z3".
   495 
   496 * Added basic SMT support for datatypes, records, and typedefs using
   497 the oracle mode (no proofs).  Direct support of pairs has been dropped
   498 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   499 support for a similar behavior).  Minor INCOMPATIBILITY.
   500 
   501 * Changed SMT configuration options:
   502   - Renamed:
   503     z3_proofs ~> smt_oracle (with inverted meaning)
   504     z3_trace_assms ~> smt_trace_used_facts
   505     INCOMPATIBILITY.
   506   - Added:
   507     smt_verbose
   508     smt_random_seed
   509     smt_datatypes
   510     smt_infer_triggers
   511     smt_monomorph_limit
   512     cvc3_options
   513     remote_cvc3_options
   514     remote_z3_options
   515     yices_options
   516 
   517 * Boogie output files (.b2i files) need to be declared in the theory
   518 header.
   519 
   520 * Simplification procedure "list_to_set_comprehension" rewrites list
   521 comprehensions applied to List.set to set comprehensions.  Occasional
   522 INCOMPATIBILITY, may be deactivated like this:
   523 
   524   declare [[simproc del: list_to_set_comprehension]]
   525 
   526 * Removed old version of primrec package.  INCOMPATIBILITY.
   527 
   528 * Removed simplifier congruence rule of "prod_case", as has for long
   529 been the case with "split".  INCOMPATIBILITY.
   530 
   531 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   532 
   533 * Removed [split_format ... and ... and ...] version of
   534 [split_format].  Potential INCOMPATIBILITY.
   535 
   536 * Predicate "sorted" now defined inductively, with nice induction
   537 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   538 
   539 * Constant "contents" renamed to "the_elem", to free the generic name
   540 contents for other uses.  INCOMPATIBILITY.
   541 
   542 * Renamed class eq and constant eq (for code generation) to class
   543 equal and constant equal, plus renaming of related facts and various
   544 tuning.  INCOMPATIBILITY.
   545 
   546 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   547 
   548 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   549 INCOMPATIBILITY.
   550 
   551 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   552 avoid confusion with finite sets.  INCOMPATIBILITY.
   553 
   554 * Abandoned locales equiv, congruent and congruent2 for equivalence
   555 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   556 for congruent(2)).
   557 
   558 * Some previously unqualified names have been qualified:
   559 
   560   types
   561     bool ~> HOL.bool
   562     nat ~> Nat.nat
   563 
   564   constants
   565     Trueprop ~> HOL.Trueprop
   566     True ~> HOL.True
   567     False ~> HOL.False
   568     op & ~> HOL.conj
   569     op | ~> HOL.disj
   570     op --> ~> HOL.implies
   571     op = ~> HOL.eq
   572     Not ~> HOL.Not
   573     The ~> HOL.The
   574     All ~> HOL.All
   575     Ex ~> HOL.Ex
   576     Ex1 ~> HOL.Ex1
   577     Let ~> HOL.Let
   578     If ~> HOL.If
   579     Ball ~> Set.Ball
   580     Bex ~> Set.Bex
   581     Suc ~> Nat.Suc
   582     Pair ~> Product_Type.Pair
   583     fst ~> Product_Type.fst
   584     snd ~> Product_Type.snd
   585     curry ~> Product_Type.curry
   586     op : ~> Set.member
   587     Collect ~> Set.Collect
   588 
   589 INCOMPATIBILITY.
   590 
   591 * More canonical naming convention for some fundamental definitions:
   592 
   593     bot_bool_eq ~> bot_bool_def
   594     top_bool_eq ~> top_bool_def
   595     inf_bool_eq ~> inf_bool_def
   596     sup_bool_eq ~> sup_bool_def
   597     bot_fun_eq  ~> bot_fun_def
   598     top_fun_eq  ~> top_fun_def
   599     inf_fun_eq  ~> inf_fun_def
   600     sup_fun_eq  ~> sup_fun_def
   601 
   602 INCOMPATIBILITY.
   603 
   604 * More stylized fact names:
   605 
   606   expand_fun_eq ~> fun_eq_iff
   607   expand_set_eq ~> set_eq_iff
   608   set_ext       ~> set_eqI
   609   nat_number    ~> eval_nat_numeral
   610 
   611 INCOMPATIBILITY.
   612 
   613 * Refactoring of code-generation specific operations in theory List:
   614 
   615   constants
   616     null ~> List.null
   617 
   618   facts
   619     mem_iff ~> member_def
   620     null_empty ~> null_def
   621 
   622 INCOMPATIBILITY.  Note that these were not supposed to be used
   623 regularly unless for striking reasons; their main purpose was code
   624 generation.
   625 
   626 Various operations from the Haskell prelude are used for generating
   627 Haskell code.
   628 
   629 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   630 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   631 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   632 
   633 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   634 "*" and "+" respectively.  INCOMPATIBILITY.
   635 
   636 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   637 "Sum_Type.Plus" instead.
   638 
   639 * Constant "split" has been merged with constant "prod_case"; names of
   640 ML functions, facts etc. involving split have been retained so far,
   641 though.  INCOMPATIBILITY.
   642 
   643 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   644 instead.  INCOMPATIBILITY.
   645 
   646 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   647 INCOMPATIBILITY.
   648 
   649 * Former theory Library/Enum is now part of the HOL-Main image.
   650 INCOMPATIBILITY: all constants of the Enum theory now have to be
   651 referred to by its qualified name.
   652 
   653   enum    ~>  Enum.enum
   654   nlists  ~>  Enum.nlists
   655   product ~>  Enum.product
   656 
   657 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   658 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   659 INCOMPATIBILITY.
   660 
   661 * Theory Library/SetsAndFunctions has been split into
   662 Library/Function_Algebras and Library/Set_Algebras; canonical names
   663 for instance definitions for functions; various improvements.
   664 INCOMPATIBILITY.
   665 
   666 * Theory Library/Multiset provides stable quicksort implementation of
   667 sort_key.
   668 
   669 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   670 INCOMPATIBILITY.
   671 
   672 * Session Multivariate_Analysis: introduced a type class for euclidean
   673 space.  Most theorems are now stated in terms of euclidean spaces
   674 instead of finite cartesian products.
   675 
   676   types
   677     real ^ 'n ~>  'a::real_vector
   678               ~>  'a::euclidean_space
   679               ~>  'a::ordered_euclidean_space
   680         (depends on your needs)
   681 
   682   constants
   683      _ $ _        ~> _ $$ _
   684      \<chi> x. _  ~> \<chi>\<chi> x. _
   685      CARD('n)     ~> DIM('a)
   686 
   687 Also note that the indices are now natural numbers and not from some
   688 finite type. Finite cartesian products of euclidean spaces, products
   689 of euclidean spaces the real and complex numbers are instantiated to
   690 be euclidean_spaces.  INCOMPATIBILITY.
   691 
   692 * Session Probability: introduced pextreal as positive extended real
   693 numbers.  Use pextreal as value for measures.  Introduce the
   694 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   695 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   696 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   697 
   698 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   699 INCOMPATIBILITY.
   700 
   701 * Session SPARK (with image HOL-SPARK) provides commands to load and
   702 prove verification conditions generated by the SPARK Ada program
   703 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   704 
   705 
   706 *** HOL-Algebra ***
   707 
   708 * Theorems for additive ring operations (locale abelian_monoid and
   709 descendants) are generated by interpretation from their multiplicative
   710 counterparts.  Names (in particular theorem names) have the mandatory
   711 qualifier 'add'.  Previous theorem names are redeclared for
   712 compatibility.
   713 
   714 * Structure "int_ring" is now an abbreviation (previously a
   715 definition).  This fits more natural with advanced interpretations.
   716 
   717 
   718 *** HOLCF ***
   719 
   720 * The domain package now runs in definitional mode by default: The
   721 former command 'new_domain' is now called 'domain'.  To use the domain
   722 package in its original axiomatic mode, use 'domain (unsafe)'.
   723 INCOMPATIBILITY.
   724 
   725 * The new class "domain" is now the default sort.  Class "predomain"
   726 is an unpointed version of "domain". Theories can be updated by
   727 replacing sort annotations as shown below.  INCOMPATIBILITY.
   728 
   729   'a::type ~> 'a::countable
   730   'a::cpo  ~> 'a::predomain
   731   'a::pcpo ~> 'a::domain
   732 
   733 * The old type class "rep" has been superseded by class "domain".
   734 Accordingly, users of the definitional package must remove any
   735 "default_sort rep" declarations.  INCOMPATIBILITY.
   736 
   737 * The domain package (definitional mode) now supports unpointed
   738 predomain argument types, as long as they are marked 'lazy'. (Strict
   739 arguments must be in class "domain".) For example, the following
   740 domain definition now works:
   741 
   742   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   743 
   744 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   745 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   746 'a option, and 'a list.  Additionally, it configures fixrec and the
   747 domain package to work with these types.  For example:
   748 
   749   fixrec isInl :: "('a + 'b) u -> tr"
   750     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   751 
   752   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   753 
   754 * The "(permissive)" option of fixrec has been replaced with a
   755 per-equation "(unchecked)" option. See
   756 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   757 
   758 * The "bifinite" class no longer fixes a constant "approx"; the class
   759 now just asserts that such a function exists.  INCOMPATIBILITY.
   760 
   761 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   762 defines an embedding of type 'a defl into udom by default; instances
   763 of "bifinite" and "domain" classes are available in
   764 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   765 
   766 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   767 
   768 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   769 
   770 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   771 
   772 * The function "cprod_map" has been renamed to "prod_map".
   773 INCOMPATIBILITY.
   774 
   775 * The monadic bind operator on each powerdomain has new binder syntax
   776 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   777 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   778 
   779 * The infix syntax for binary union on each powerdomain has changed
   780 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   781 syntax.  INCOMPATIBILITY.
   782 
   783 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   784 still supported as an input translation.
   785 
   786 * Renamed some theorems (the original names are also still available).
   787 
   788   expand_fun_below   ~> fun_below_iff
   789   below_fun_ext      ~> fun_belowI
   790   expand_cfun_eq     ~> cfun_eq_iff
   791   ext_cfun           ~> cfun_eqI
   792   expand_cfun_below  ~> cfun_below_iff
   793   below_cfun_ext     ~> cfun_belowI
   794   cont2cont_Rep_CFun ~> cont2cont_APP
   795 
   796 * The Abs and Rep functions for various types have changed names.
   797 Related theorem names have also changed to match. INCOMPATIBILITY.
   798 
   799   Rep_CFun  ~> Rep_cfun
   800   Abs_CFun  ~> Abs_cfun
   801   Rep_Sprod ~> Rep_sprod
   802   Abs_Sprod ~> Abs_sprod
   803   Rep_Ssum  ~> Rep_ssum
   804   Abs_Ssum  ~> Abs_ssum
   805 
   806 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   807 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   808 
   809 * Various changes to bisimulation/coinduction with domain package:
   810 
   811   - Definitions of "bisim" constants no longer mention definedness.
   812   - With mutual recursion, "bisim" predicate is now curried.
   813   - With mutual recursion, each type gets a separate coind theorem.
   814   - Variable names in bisim_def and coinduct rules have changed.
   815 
   816 INCOMPATIBILITY.
   817 
   818 * Case combinators generated by the domain package for type "foo" are
   819 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   820 
   821 * Several theorems have been renamed to more accurately reflect the
   822 names of constants and types involved.  INCOMPATIBILITY.
   823 
   824   thelub_const    ~> lub_const
   825   lub_const       ~> is_lub_const
   826   thelubI         ~> lub_eqI
   827   is_lub_lub      ~> is_lubD2
   828   lubI            ~> is_lub_lub
   829   unique_lub      ~> is_lub_unique
   830   is_ub_lub       ~> is_lub_rangeD1
   831   lub_bin_chain   ~> is_lub_bin_chain
   832   lub_fun         ~> is_lub_fun
   833   thelub_fun      ~> lub_fun
   834   thelub_cfun     ~> lub_cfun
   835   thelub_Pair     ~> lub_Pair
   836   lub_cprod       ~> is_lub_prod
   837   thelub_cprod    ~> lub_prod
   838   minimal_cprod   ~> minimal_prod
   839   inst_cprod_pcpo ~> inst_prod_pcpo
   840   UU_I            ~> bottomI
   841   compact_UU      ~> compact_bottom
   842   deflation_UU    ~> deflation_bottom
   843   finite_deflation_UU ~> finite_deflation_bottom
   844 
   845 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   846 
   847   sq_ord_less_eq_trans ~> below_eq_trans
   848   sq_ord_eq_less_trans ~> eq_below_trans
   849   refl_less            ~> below_refl
   850   trans_less           ~> below_trans
   851   antisym_less         ~> below_antisym
   852   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   853   box_less             ~> box_below
   854   rev_trans_less       ~> rev_below_trans
   855   not_less2not_eq      ~> not_below2not_eq
   856   less_UU_iff          ~> below_UU_iff
   857   flat_less_iff        ~> flat_below_iff
   858   adm_less             ~> adm_below
   859   adm_not_less         ~> adm_not_below
   860   adm_compact_not_less ~> adm_compact_not_below
   861   less_fun_def         ~> below_fun_def
   862   expand_fun_less      ~> fun_below_iff
   863   less_fun_ext         ~> fun_belowI
   864   less_discr_def       ~> below_discr_def
   865   discr_less_eq        ~> discr_below_eq
   866   less_unit_def        ~> below_unit_def
   867   less_cprod_def       ~> below_prod_def
   868   prod_lessI           ~> prod_belowI
   869   Pair_less_iff        ~> Pair_below_iff
   870   fst_less_iff         ~> fst_below_iff
   871   snd_less_iff         ~> snd_below_iff
   872   expand_cfun_less     ~> cfun_below_iff
   873   less_cfun_ext        ~> cfun_belowI
   874   injection_less       ~> injection_below
   875   less_up_def          ~> below_up_def
   876   not_Iup_less         ~> not_Iup_below
   877   Iup_less             ~> Iup_below
   878   up_less              ~> up_below
   879   Def_inject_less_eq   ~> Def_below_Def
   880   Def_less_is_eq       ~> Def_below_iff
   881   spair_less_iff       ~> spair_below_iff
   882   less_sprod           ~> below_sprod
   883   spair_less           ~> spair_below
   884   sfst_less_iff        ~> sfst_below_iff
   885   ssnd_less_iff        ~> ssnd_below_iff
   886   fix_least_less       ~> fix_least_below
   887   dist_less_one        ~> dist_below_one
   888   less_ONE             ~> below_ONE
   889   ONE_less_iff         ~> ONE_below_iff
   890   less_sinlD           ~> below_sinlD
   891   less_sinrD           ~> below_sinrD
   892 
   893 
   894 *** FOL and ZF ***
   895 
   896 * All constant names are now qualified internally and use proper
   897 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   898 
   899 
   900 *** ML ***
   901 
   902 * Antiquotation @{assert} inlines a function bool -> unit that raises
   903 Fail if the argument is false.  Due to inlining the source position of
   904 failed assertions is included in the error output.
   905 
   906 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   907 text is in practice always evaluated with a stable theory checkpoint.
   908 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   909 
   910 * Antiquotation @{theory A} refers to theory A from the ancestry of
   911 the current context, not any accidental theory loader state as before.
   912 Potential INCOMPATIBILITY, subtle change in semantics.
   913 
   914 * Syntax.pretty_priority (default 0) configures the required priority
   915 of pretty-printed output and thus affects insertion of parentheses.
   916 
   917 * Syntax.default_root (default "any") configures the inner syntax
   918 category (nonterminal symbol) for parsing of terms.
   919 
   920 * Former exception Library.UnequalLengths now coincides with
   921 ListPair.UnequalLengths.
   922 
   923 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   924 main functionality is provided by structure Simplifier.
   925 
   926 * Renamed raw "explode" function to "raw_explode" to emphasize its
   927 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   928 almost all situations.
   929 
   930 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   931 See implementation manual for further details on exceptions in
   932 Isabelle/ML.
   933 
   934 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   935 meaning.
   936 
   937 * Renamed structure PureThy to Pure_Thy and moved most of its
   938 operations to structure Global_Theory, to emphasize that this is
   939 rarely-used global-only stuff.
   940 
   941 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   942 instead (or tracing for high-volume output).
   943 
   944 * Configuration option show_question_marks only affects regular pretty
   945 printing of types and terms, not raw Term.string_of_vname.
   946 
   947 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   948 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   949 @{thms} for most purposes.
   950 
   951 * ML structure Unsynchronized is never opened, not even in Isar
   952 interaction mode as before.  Old Unsynchronized.set etc. have been
   953 discontinued -- use plain := instead.  This should be *rare* anyway,
   954 since modern tools always work via official context data, notably
   955 configuration options.
   956 
   957 * Parallel and asynchronous execution requires special care concerning
   958 interrupts.  Structure Exn provides some convenience functions that
   959 avoid working directly with raw Interrupt.  User code must not absorb
   960 interrupts -- intermediate handling (for cleanup etc.) needs to be
   961 followed by re-raising of the original exception.  Another common
   962 source of mistakes are "handle _" patterns, which make the meaning of
   963 the program subject to physical effects of the environment.
   964 
   965 
   966 
   967 New in Isabelle2009-2 (June 2010)
   968 ---------------------------------
   969 
   970 *** General ***
   971 
   972 * Authentic syntax for *all* logical entities (type classes, type
   973 constructors, term constants): provides simple and robust
   974 correspondence between formal entities and concrete syntax.  Within
   975 the parse tree / AST representations, "constants" are decorated by
   976 their category (class, type, const) and spelled out explicitly with
   977 their full internal name.
   978 
   979 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   980 and translations (translation rules and translation functions in ML).
   981 Some hints on upgrading:
   982 
   983   - Many existing uses of 'syntax' and 'translations' can be replaced
   984     by more modern 'type_notation', 'notation' and 'abbreviation',
   985     which are independent of this issue.
   986 
   987   - 'translations' require markup within the AST; the term syntax
   988     provides the following special forms:
   989 
   990       CONST c   -- produces syntax version of constant c from context
   991       XCONST c  -- literally c, checked as constant from context
   992       c         -- literally c, if declared by 'syntax'
   993 
   994     Plain identifiers are treated as AST variables -- occasionally the
   995     system indicates accidental variables via the error "rhs contains
   996     extra variables".
   997 
   998     Type classes and type constructors are marked according to their
   999     concrete syntax.  Some old translations rules need to be written
  1000     for the "type" category, using type constructor application
  1001     instead of pseudo-term application of the default category
  1002     "logic".
  1003 
  1004   - 'parse_translation' etc. in ML may use the following
  1005     antiquotations:
  1006 
  1007       @{class_syntax c}   -- type class c within parse tree / AST
  1008       @{term_syntax c}    -- type constructor c within parse tree / AST
  1009       @{const_syntax c}   -- ML version of "CONST c" above
  1010       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1011 
  1012   - Literal types within 'typed_print_translations', i.e. those *not*
  1013     represented as pseudo-terms are represented verbatim.  Use @{class
  1014     c} or @{type_name c} here instead of the above syntax
  1015     antiquotations.
  1016 
  1017 Note that old non-authentic syntax was based on unqualified base
  1018 names, so all of the above "constant" names would coincide.  Recall
  1019 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1020 diagnose syntax problems.
  1021 
  1022 * Type constructors admit general mixfix syntax, not just infix.
  1023 
  1024 * Concrete syntax may be attached to local entities without a proof
  1025 body, too.  This works via regular mixfix annotations for 'fix',
  1026 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1027 similar to the 'notation' command in theory specifications.
  1028 
  1029 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1030 need to specify constant name and syntax separately.  Internal ML
  1031 datatype constructors have been renamed from InfixName to Infix etc.
  1032 Minor INCOMPATIBILITY.
  1033 
  1034 * Schematic theorem statements need to be explicitly markup as such,
  1035 via commands 'schematic_lemma', 'schematic_theorem',
  1036 'schematic_corollary'.  Thus the relevance of the proof is made
  1037 syntactically clear, which impacts performance in a parallel or
  1038 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1039 
  1040 * Use of cumulative prems via "!" in some proof methods has been
  1041 discontinued (old legacy feature).
  1042 
  1043 * References 'trace_simp' and 'debug_simp' have been replaced by
  1044 configuration options stored in the context. Enabling tracing (the
  1045 case of debugging is similar) in proofs works via
  1046 
  1047   using [[trace_simp = true]]
  1048 
  1049 Tracing is then active for all invocations of the simplifier in
  1050 subsequent goal refinement steps. Tracing may also still be enabled or
  1051 disabled via the ProofGeneral settings menu.
  1052 
  1053 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1054 'hide_fact' replace the former 'hide' KIND command.  Minor
  1055 INCOMPATIBILITY.
  1056 
  1057 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1058 more efficient than combinations with -q1 or -q2.
  1059 
  1060 
  1061 *** Pure ***
  1062 
  1063 * Proofterms record type-class reasoning explicitly, using the
  1064 "unconstrain" operation internally.  This eliminates all sort
  1065 constraints from a theorem and proof, introducing explicit
  1066 OFCLASS-premises.  On the proof term level, this operation is
  1067 automatically applied at theorem boundaries, such that closed proofs
  1068 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1069 inspect proof terms.
  1070 
  1071 * Local theory specifications may depend on extra type variables that
  1072 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1073 are added internally.  For example:
  1074 
  1075   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1076 
  1077 * Predicates of locales introduced by classes carry a mandatory
  1078 "class" prefix.  INCOMPATIBILITY.
  1079 
  1080 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1081 
  1082 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1083 'class' instead.
  1084 
  1085 * Command 'code_reflect' allows to incorporate generated ML code into
  1086 runtime environment; replaces immature code_datatype antiquotation.
  1087 INCOMPATIBILITY.
  1088 
  1089 * Code generator: simple concept for abstract datatypes obeying
  1090 invariants.
  1091 
  1092 * Code generator: details of internal data cache have no impact on the
  1093 user space functionality any longer.
  1094 
  1095 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1096 subgoals.  This is more appropriate for interpretations with 'where'.
  1097 INCOMPATIBILITY.
  1098 
  1099 * Command 'example_proof' opens an empty proof body.  This allows to
  1100 experiment with Isar, without producing any persistent result.
  1101 
  1102 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1103 within a local theory context, with explicit checking of the
  1104 constructors involved (in contrast to the raw 'syntax' versions).
  1105 
  1106 * Commands 'types' and 'typedecl' now work within a local theory
  1107 context -- without introducing dependencies on parameters or
  1108 assumptions, which is not possible in Isabelle/Pure.
  1109 
  1110 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1111 within a local theory context.  Minor INCOMPATIBILITY.
  1112 
  1113 
  1114 *** HOL ***
  1115 
  1116 * Command 'typedef' now works within a local theory context -- without
  1117 introducing dependencies on parameters or assumptions, which is not
  1118 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1119 contain multiple interpretations of local typedefs (with different
  1120 non-emptiness proofs), even in a global theory context.
  1121 
  1122 * New package for quotient types.  Commands 'quotient_type' and
  1123 'quotient_definition' may be used for defining types and constants by
  1124 quotient constructions.  An example is the type of integers created by
  1125 quotienting pairs of natural numbers:
  1126 
  1127   fun
  1128     intrel :: "(nat * nat) => (nat * nat) => bool"
  1129   where
  1130     "intrel (x, y) (u, v) = (x + v = u + y)"
  1131 
  1132   quotient_type int = "nat * nat" / intrel
  1133     by (auto simp add: equivp_def expand_fun_eq)
  1134 
  1135   quotient_definition
  1136     "0::int" is "(0::nat, 0::nat)"
  1137 
  1138 The method "lifting" can be used to lift of theorems from the
  1139 underlying "raw" type to the quotient type.  The example
  1140 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1141 construction and provides a reasoning infrastructure for finite sets.
  1142 
  1143 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1144 clash with new theory Quotient in Main HOL.
  1145 
  1146 * Moved the SMT binding into the main HOL session, eliminating
  1147 separate HOL-SMT session.
  1148 
  1149 * List membership infix mem operation is only an input abbreviation.
  1150 INCOMPATIBILITY.
  1151 
  1152 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1153 for future developements; former Library/Word.thy is still present in
  1154 the AFP entry RSAPPS.
  1155 
  1156 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1157 longer shadowed.  INCOMPATIBILITY.
  1158 
  1159 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1160 INCOMPATIBILITY.
  1161 
  1162 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1163 INCOMPATIBILITY.
  1164 
  1165 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1166 instead.  INCOMPATIBILITY.
  1167 
  1168 * Dropped several real-specific versions of lemmas about floor and
  1169 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1170 instead.  INCOMPATIBILITY.
  1171 
  1172   floor_number_of_eq         ~> floor_number_of
  1173   le_floor_eq_number_of      ~> number_of_le_floor
  1174   le_floor_eq_zero           ~> zero_le_floor
  1175   le_floor_eq_one            ~> one_le_floor
  1176   floor_less_eq_number_of    ~> floor_less_number_of
  1177   floor_less_eq_zero         ~> floor_less_zero
  1178   floor_less_eq_one          ~> floor_less_one
  1179   less_floor_eq_number_of    ~> number_of_less_floor
  1180   less_floor_eq_zero         ~> zero_less_floor
  1181   less_floor_eq_one          ~> one_less_floor
  1182   floor_le_eq_number_of      ~> floor_le_number_of
  1183   floor_le_eq_zero           ~> floor_le_zero
  1184   floor_le_eq_one            ~> floor_le_one
  1185   floor_subtract_number_of   ~> floor_diff_number_of
  1186   floor_subtract_one         ~> floor_diff_one
  1187   ceiling_number_of_eq       ~> ceiling_number_of
  1188   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1189   ceiling_le_zero_eq         ~> ceiling_le_zero
  1190   ceiling_le_eq_one          ~> ceiling_le_one
  1191   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1192   less_ceiling_eq_zero       ~> zero_less_ceiling
  1193   less_ceiling_eq_one        ~> one_less_ceiling
  1194   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1195   ceiling_less_eq_zero       ~> ceiling_less_zero
  1196   ceiling_less_eq_one        ~> ceiling_less_one
  1197   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1198   le_ceiling_eq_zero         ~> zero_le_ceiling
  1199   le_ceiling_eq_one          ~> one_le_ceiling
  1200   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1201   ceiling_subtract_one       ~> ceiling_diff_one
  1202 
  1203 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1204 application of the various fold combinators on finite sets.
  1205 
  1206 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1207 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1208 implementation.  INCOMPATIBILTY.
  1209 
  1210 * Theory Library/Coinductive_List has been removed -- superseded by
  1211 AFP/thys/Coinductive.
  1212 
  1213 * Theory PReal, including the type "preal" and related operations, has
  1214 been removed.  INCOMPATIBILITY.
  1215 
  1216 * Real: new development using Cauchy Sequences.
  1217 
  1218 * Split off theory "Big_Operators" containing setsum, setprod,
  1219 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1220 
  1221 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1222 "Int" etc.  INCOMPATIBILITY.
  1223 
  1224 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1225 
  1226 * New set of rules "ac_simps" provides combined assoc / commute
  1227 rewrites for all interpretations of the appropriate generic locales.
  1228 
  1229 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1230 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1231 appropriate and more consistent names suitable for name prefixes
  1232 within the HOL theories.  INCOMPATIBILITY.
  1233 
  1234 * Some generic constants have been put to appropriate theories:
  1235   - less_eq, less: Orderings
  1236   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1237   - inverse, divide: Rings
  1238 INCOMPATIBILITY.
  1239 
  1240 * More consistent naming of type classes involving orderings (and
  1241 lattices):
  1242 
  1243     lower_semilattice                   ~> semilattice_inf
  1244     upper_semilattice                   ~> semilattice_sup
  1245 
  1246     dense_linear_order                  ~> dense_linorder
  1247 
  1248     pordered_ab_group_add               ~> ordered_ab_group_add
  1249     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1250     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1251     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1252     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1253     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1254     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1255     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1256     pordered_comm_ring                  ~> ordered_comm_ring
  1257     pordered_comm_semiring              ~> ordered_comm_semiring
  1258     pordered_ring                       ~> ordered_ring
  1259     pordered_ring_abs                   ~> ordered_ring_abs
  1260     pordered_semiring                   ~> ordered_semiring
  1261 
  1262     ordered_ab_group_add                ~> linordered_ab_group_add
  1263     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1264     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1265     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1266     ordered_field                       ~> linordered_field
  1267     ordered_field_no_lb                 ~> linordered_field_no_lb
  1268     ordered_field_no_ub                 ~> linordered_field_no_ub
  1269     ordered_field_dense_linear_order    ~> dense_linordered_field
  1270     ordered_idom                        ~> linordered_idom
  1271     ordered_ring                        ~> linordered_ring
  1272     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1273     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1274     ordered_ring_strict                 ~> linordered_ring_strict
  1275     ordered_semidom                     ~> linordered_semidom
  1276     ordered_semiring                    ~> linordered_semiring
  1277     ordered_semiring_1                  ~> linordered_semiring_1
  1278     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1279     ordered_semiring_strict             ~> linordered_semiring_strict
  1280 
  1281   The following slightly odd type classes have been moved to a
  1282   separate theory Library/Lattice_Algebras:
  1283 
  1284     lordered_ab_group_add               ~> lattice_ab_group_add
  1285     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1286     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1287     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1288     lordered_ring                       ~> lattice_ring
  1289 
  1290 INCOMPATIBILITY.
  1291 
  1292 * Refined field classes:
  1293   - classes division_ring_inverse_zero, field_inverse_zero,
  1294     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1295     subsumes former division_by_zero class;
  1296   - numerous lemmas have been ported from field to division_ring.
  1297 INCOMPATIBILITY.
  1298 
  1299 * Refined algebra theorem collections:
  1300   - dropped theorem group group_simps, use algebra_simps instead;
  1301   - dropped theorem group ring_simps, use field_simps instead;
  1302   - proper theorem collection field_simps subsumes former theorem
  1303     groups field_eq_simps and field_simps;
  1304   - dropped lemma eq_minus_self_iff which is a duplicate for
  1305     equal_neg_zero.
  1306 INCOMPATIBILITY.
  1307 
  1308 * Theory Finite_Set and List: some lemmas have been generalized from
  1309 sets to lattices:
  1310 
  1311   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1312   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1313   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1314   union_Union_fold_union        ~> sup_Sup_fold_sup
  1315   Inter_fold_inter              ~> Inf_fold_inf
  1316   Union_fold_union              ~> Sup_fold_sup
  1317   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1318   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1319   INTER_fold_inter              ~> INFI_fold_inf
  1320   UNION_fold_union              ~> SUPR_fold_sup
  1321 
  1322 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1323 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1324 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1325 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1326 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1327 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1328 
  1329 * Reorganized theory Multiset: swapped notation of pointwise and
  1330 multiset order:
  1331 
  1332   - pointwise ordering is instance of class order with standard syntax
  1333     <= and <;
  1334   - multiset ordering has syntax <=# and <#; partial order properties
  1335     are provided by means of interpretation with prefix
  1336     multiset_order;
  1337   - less duplication, less historical organization of sections,
  1338     conversion from associations lists to multisets, rudimentary code
  1339     generation;
  1340   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1341     if needed.
  1342 
  1343 Renamed:
  1344 
  1345   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1346   multi_count_ext  ~>  multiset_ext
  1347   diff_union_inverse2  ~>  diff_union_cancelR
  1348 
  1349 INCOMPATIBILITY.
  1350 
  1351 * Theory Permutation: replaced local "remove" by List.remove1.
  1352 
  1353 * Code generation: ML and OCaml code is decorated with signatures.
  1354 
  1355 * Theory List: added transpose.
  1356 
  1357 * Library/Nat_Bijection.thy is a collection of bijective functions
  1358 between nat and other types, which supersedes the older libraries
  1359 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1360 
  1361   Constants:
  1362   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1363   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1364   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1365   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1366   Countable.pair_encode           ~> prod_encode
  1367   NatIso.prod2nat                 ~> prod_encode
  1368   NatIso.nat2prod                 ~> prod_decode
  1369   NatIso.sum2nat                  ~> sum_encode
  1370   NatIso.nat2sum                  ~> sum_decode
  1371   NatIso.list2nat                 ~> list_encode
  1372   NatIso.nat2list                 ~> list_decode
  1373   NatIso.set2nat                  ~> set_encode
  1374   NatIso.nat2set                  ~> set_decode
  1375 
  1376   Lemmas:
  1377   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1378   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1379   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1380   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1381   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1382   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1383   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1384   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1385   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1386   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1387   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1388   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1389   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1390 
  1391 * Sledgehammer:
  1392   - Renamed ATP commands:
  1393     atp_info     ~> sledgehammer running_atps
  1394     atp_kill     ~> sledgehammer kill_atps
  1395     atp_messages ~> sledgehammer messages
  1396     atp_minimize ~> sledgehammer minimize
  1397     print_atps   ~> sledgehammer available_atps
  1398     INCOMPATIBILITY.
  1399   - Added user's manual ("isabelle doc sledgehammer").
  1400   - Added option syntax and "sledgehammer_params" to customize
  1401     Sledgehammer's behavior.  See the manual for details.
  1402   - Modified the Isar proof reconstruction code so that it produces
  1403     direct proofs rather than proofs by contradiction.  (This feature
  1404     is still experimental.)
  1405   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1406     full-typed mode.
  1407   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1408 
  1409 * Nitpick:
  1410   - Added and implemented "binary_ints" and "bits" options.
  1411   - Added "std" option and implemented support for nonstandard models.
  1412   - Added and implemented "finitize" option to improve the precision
  1413     of infinite datatypes based on a monotonicity analysis.
  1414   - Added support for quotient types.
  1415   - Added support for "specification" and "ax_specification"
  1416     constructs.
  1417   - Added support for local definitions (for "function" and
  1418     "termination" proofs).
  1419   - Added support for term postprocessors.
  1420   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1421   - Improved efficiency of "destroy_constrs" optimization.
  1422   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1423     record getters.
  1424   - Fixed soundness bug related to higher-order constructors.
  1425   - Fixed soundness bug when "full_descrs" is enabled.
  1426   - Improved precision of set constructs.
  1427   - Added "atoms" option.
  1428   - Added cache to speed up repeated Kodkod invocations on the same
  1429     problems.
  1430   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1431     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1432     "SAT4J_Light".  INCOMPATIBILITY.
  1433   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1434     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1435   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1436 
  1437 * Method "induct" now takes instantiations of the form t, where t is not
  1438   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1439   If this is not intended, t has to be enclosed in parentheses.
  1440   By default, the equalities generated by definitional instantiations
  1441   are pre-simplified, which may cause parameters of inductive cases
  1442   to disappear, or may even delete some of the inductive cases.
  1443   Use "induct (no_simp)" instead of "induct" to restore the old
  1444   behaviour. The (no_simp) option is also understood by the "cases"
  1445   and "nominal_induct" methods, which now perform pre-simplification, too.
  1446   INCOMPATIBILITY.
  1447 
  1448 
  1449 *** HOLCF ***
  1450 
  1451 * Variable names in lemmas generated by the domain package have
  1452 changed; the naming scheme is now consistent with the HOL datatype
  1453 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1454 
  1455 * The domain package no longer defines the function "foo_copy" for
  1456 recursive domain "foo".  The reach lemma is now stated directly in
  1457 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1458 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1459 
  1460 * Most definedness lemmas generated by the domain package (previously
  1461 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1462 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1463 Proofs that used definedness lemmas as intro rules may break,
  1464 potential INCOMPATIBILITY.
  1465 
  1466 * Induction and casedist rules generated by the domain package now
  1467 declare proper case_names (one called "bottom", and one named for each
  1468 constructor).  INCOMPATIBILITY.
  1469 
  1470 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1471 rules are generated for each domain, INCOMPATIBILITY.
  1472 
  1473   foo_bar.reach       ~> foo.reach  bar.reach
  1474   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1475 
  1476 * Some lemmas generated by the domain package have been renamed for
  1477 consistency with the datatype package, INCOMPATIBILITY.
  1478 
  1479   foo.ind        ~> foo.induct
  1480   foo.finite_ind ~> foo.finite_induct
  1481   foo.coind      ~> foo.coinduct
  1482   foo.casedist   ~> foo.exhaust
  1483   foo.exhaust    ~> foo.nchotomy
  1484 
  1485 * For consistency with other definition packages, the fixrec package
  1486 now generates qualified theorem names, INCOMPATIBILITY.
  1487 
  1488   foo_simps  ~> foo.simps
  1489   foo_unfold ~> foo.unfold
  1490   foo_induct ~> foo.induct
  1491 
  1492 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1493 method and internal fixrec proofs now use the default simpset instead.
  1494 INCOMPATIBILITY.
  1495 
  1496 * The "contlub" predicate has been removed.  Proof scripts should use
  1497 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1498 
  1499 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1500 
  1501 * The constants cpair, cfst, and csnd have been removed in favor of
  1502 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1503 
  1504 
  1505 *** ML ***
  1506 
  1507 * Antiquotations for basic formal entities:
  1508 
  1509     @{class NAME}         -- type class
  1510     @{class_syntax NAME}  -- syntax representation of the above
  1511 
  1512     @{type_name NAME}     -- logical type
  1513     @{type_abbrev NAME}   -- type abbreviation
  1514     @{nonterminal NAME}   -- type of concrete syntactic category
  1515     @{type_syntax NAME}   -- syntax representation of any of the above
  1516 
  1517     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1518     @{const_abbrev NAME}  -- abbreviated constant
  1519     @{const_syntax NAME}  -- syntax representation of any of the above
  1520 
  1521 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1522 syntax constant (cf. 'syntax' command).
  1523 
  1524 * Antiquotation @{make_string} inlines a function to print arbitrary
  1525 values similar to the ML toplevel.  The result is compiler dependent
  1526 and may fall back on "?" in certain situations.
  1527 
  1528 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1529 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1530 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1531 not work with the asynchronous Isar document model.
  1532 
  1533 * Configuration options now admit dynamic default values, depending on
  1534 the context or even global references.
  1535 
  1536 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1537 uses an efficient external library if available (for Poly/ML).
  1538 
  1539 * Renamed some important ML structures, while keeping the old names
  1540 for some time as aliases within the structure Legacy:
  1541 
  1542   OuterKeyword  ~>  Keyword
  1543   OuterLex      ~>  Token
  1544   OuterParse    ~>  Parse
  1545   OuterSyntax   ~>  Outer_Syntax
  1546   PrintMode     ~>  Print_Mode
  1547   SpecParse     ~>  Parse_Spec
  1548   ThyInfo       ~>  Thy_Info
  1549   ThyLoad       ~>  Thy_Load
  1550   ThyOutput     ~>  Thy_Output
  1551   TypeInfer     ~>  Type_Infer
  1552 
  1553 Note that "open Legacy" simplifies porting of sources, but forgetting
  1554 to remove it again will complicate porting again in the future.
  1555 
  1556 * Most operations that refer to a global context are named
  1557 accordingly, e.g. Simplifier.global_context or
  1558 ProofContext.init_global.  There are some situations where a global
  1559 context actually works, but under normal circumstances one needs to
  1560 pass the proper local context through the code!
  1561 
  1562 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1563 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1564 Pretty.pp argument to merge, which is absent in the standard
  1565 Theory_Data version.
  1566 
  1567 * Sorts.certify_sort and derived "cert" operations for types and terms
  1568 no longer minimize sorts.  Thus certification at the boundary of the
  1569 inference kernel becomes invariant under addition of class relations,
  1570 which is an important monotonicity principle.  Sorts are now minimized
  1571 in the syntax layer only, at the boundary between the end-user and the
  1572 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1573 explicitly in rare situations.
  1574 
  1575 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1576 emphasize that this is in no way a standard operation.
  1577 INCOMPATIBILITY.
  1578 
  1579 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1580 usual for resolution.  Rare INCOMPATIBILITY.
  1581 
  1582 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1583 to emphasize that these only work in a global situation (which is
  1584 quite rare).
  1585 
  1586 * Curried take and drop in library.ML; negative length is interpreted
  1587 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1588 
  1589 * Proof terms: type substitutions on proof constants now use canonical
  1590 order of type variables.  INCOMPATIBILITY for tools working with proof
  1591 terms.
  1592 
  1593 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1594 may no longer carry premises.  User-level specifications are
  1595 transformed accordingly by Thm.add_axiom/add_def.
  1596 
  1597 
  1598 *** System ***
  1599 
  1600 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1601 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1602 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1603 
  1604 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1605 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1606 respectively.
  1607 
  1608 * Old lib/scripts/polyml-platform is superseded by the
  1609 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1610 variant, even on a 64 bit machine.  The following example setting
  1611 prefers 64 bit if available:
  1612 
  1613   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1614 
  1615 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1616 Isabelle/Scala layer for advanced prover interaction and integration.
  1617 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1618 component.
  1619 
  1620 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1621 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1622 similar to the default assignment of the document preparation system
  1623 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1624 provides some operations for direct access to the font without asking
  1625 the user for manual installation.
  1626 
  1627 
  1628 
  1629 New in Isabelle2009-1 (December 2009)
  1630 -------------------------------------
  1631 
  1632 *** General ***
  1633 
  1634 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1635 one backslash should be used, even in ML sources.
  1636 
  1637 
  1638 *** Pure ***
  1639 
  1640 * Locale interpretation propagates mixins along the locale hierarchy.
  1641 The currently only available mixins are the equations used to map
  1642 local definitions to terms of the target domain of an interpretation.
  1643 
  1644 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1645 loc" to print all interpretations of locale "loc" in the theory.
  1646 Interpretations in proofs are not shown.
  1647 
  1648 * Thoroughly revised locales tutorial.  New section on conditional
  1649 interpretation.
  1650 
  1651 * On instantiation of classes, remaining undefined class parameters
  1652 are formally declared.  INCOMPATIBILITY.
  1653 
  1654 
  1655 *** Document preparation ***
  1656 
  1657 * New generalized style concept for printing terms: @{foo (style) ...}
  1658 instead of @{foo_style style ...}  (old form is still retained for
  1659 backward compatibility).  Styles can be also applied for
  1660 antiquotations prop, term_type and typeof.
  1661 
  1662 
  1663 *** HOL ***
  1664 
  1665 * New proof method "smt" for a combination of first-order logic with
  1666 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1667 fixed-size bitvectors; there is also basic support for higher-order
  1668 features (esp. lambda abstractions).  It is an incomplete decision
  1669 procedure based on external SMT solvers using the oracle mechanism;
  1670 for the SMT solver Z3, this method is proof-producing.  Certificates
  1671 are provided to avoid calling the external solvers solely for
  1672 re-checking proofs.  Due to a remote SMT service there is no need for
  1673 installing SMT solvers locally.  See src/HOL/SMT.
  1674 
  1675 * New commands to load and prove verification conditions generated by
  1676 the Boogie program verifier or derived systems (e.g. the Verifying C
  1677 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1678 
  1679 * New counterexample generator tool 'nitpick' based on the Kodkod
  1680 relational model finder.  See src/HOL/Tools/Nitpick and
  1681 src/HOL/Nitpick_Examples.
  1682 
  1683 * New commands 'code_pred' and 'values' to invoke the predicate
  1684 compiler and to enumerate values of inductive predicates.
  1685 
  1686 * A tabled implementation of the reflexive transitive closure.
  1687 
  1688 * New implementation of quickcheck uses generic code generator;
  1689 default generators are provided for all suitable HOL types, records
  1690 and datatypes.  Old quickcheck can be re-activated importing theory
  1691 Library/SML_Quickcheck.
  1692 
  1693 * New testing tool Mirabelle for automated proof tools.  Applies
  1694 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1695 every proof step in a theory.  To be used in batch mode via the
  1696 "mirabelle" utility.
  1697 
  1698 * New proof method "sos" (sum of squares) for nonlinear real
  1699 arithmetic (originally due to John Harison). It requires theory
  1700 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1701 works well in practice on quantifier-free real arithmetic with +, -,
  1702 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1703 inequalities between polynomials.  It makes use of external
  1704 semidefinite programming solvers.  Method "sos" generates a
  1705 certificate that can be pasted into the proof thus avoiding the need
  1706 to call an external tool every time the proof is checked.  See
  1707 src/HOL/Library/Sum_Of_Squares.
  1708 
  1709 * New method "linarith" invokes existing linear arithmetic decision
  1710 procedure only.
  1711 
  1712 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1713 
  1714 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1715 Causes full type information to be output to the ATPs.  This slows
  1716 ATPs down considerably but eliminates a source of unsound "proofs"
  1717 that fail later.
  1718 
  1719 * New method "metisFT": A version of metis that uses full type
  1720 information in order to avoid failures of proof reconstruction.
  1721 
  1722 * New evaluator "approximate" approximates an real valued term using
  1723 the same method as the approximation method.
  1724 
  1725 * Method "approximate" now supports arithmetic expressions as
  1726 boundaries of intervals and implements interval splitting and Taylor
  1727 series expansion.
  1728 
  1729 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1730 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1731 
  1732 * New theory SupInf of the supremum and infimum operators for sets of
  1733 reals.
  1734 
  1735 * New theory Probability, which contains a development of measure
  1736 theory, eventually leading to Lebesgue integration and probability.
  1737 
  1738 * Extended Multivariate Analysis to include derivation and Brouwer's
  1739 fixpoint theorem.
  1740 
  1741 * Reorganization of number theory, INCOMPATIBILITY:
  1742   - new number theory development for nat and int, in theories Divides
  1743     and GCD as well as in new session Number_Theory
  1744   - some constants and facts now suffixed with _nat and _int
  1745     accordingly
  1746   - former session NumberTheory now named Old_Number_Theory, including
  1747     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1748   - moved theory Pocklington from src/HOL/Library to
  1749     src/HOL/Old_Number_Theory
  1750 
  1751 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1752 lcm of finite and infinite sets. It is shown that they form a complete
  1753 lattice.
  1754 
  1755 * Class semiring_div requires superclass no_zero_divisors and proof of
  1756 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1757 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1758 generalized to class semiring_div, subsuming former theorems
  1759 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1760 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1761 INCOMPATIBILITY.
  1762 
  1763 * Refinements to lattice classes and sets:
  1764   - less default intro/elim rules in locale variant, more default
  1765     intro/elim rules in class variant: more uniformity
  1766   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1767     le_inf_iff
  1768   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1769     sup_aci)
  1770   - renamed ACI to inf_sup_aci
  1771   - new class "boolean_algebra"
  1772   - class "complete_lattice" moved to separate theory
  1773     "Complete_Lattice"; corresponding constants (and abbreviations)
  1774     renamed and with authentic syntax:
  1775     Set.Inf ~>    Complete_Lattice.Inf
  1776     Set.Sup ~>    Complete_Lattice.Sup
  1777     Set.INFI ~>   Complete_Lattice.INFI
  1778     Set.SUPR ~>   Complete_Lattice.SUPR
  1779     Set.Inter ~>  Complete_Lattice.Inter
  1780     Set.Union ~>  Complete_Lattice.Union
  1781     Set.INTER ~>  Complete_Lattice.INTER
  1782     Set.UNION ~>  Complete_Lattice.UNION
  1783   - authentic syntax for
  1784     Set.Pow
  1785     Set.image
  1786   - mere abbreviations:
  1787     Set.empty               (for bot)
  1788     Set.UNIV                (for top)
  1789     Set.inter               (for inf, formerly Set.Int)
  1790     Set.union               (for sup, formerly Set.Un)
  1791     Complete_Lattice.Inter  (for Inf)
  1792     Complete_Lattice.Union  (for Sup)
  1793     Complete_Lattice.INTER  (for INFI)
  1794     Complete_Lattice.UNION  (for SUPR)
  1795   - object-logic definitions as far as appropriate
  1796 
  1797 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1798 Un_subset_iff are explicitly deleted as default simp rules; then also
  1799 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1800 deleted to achieve the desired effect.
  1801 
  1802 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1803 rules by default any longer; the same applies to min_max.inf_absorb1
  1804 etc.  INCOMPATIBILITY.
  1805 
  1806 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1807 pred_set_conv by default.  INCOMPATIBILITY.
  1808 
  1809 * Power operations on relations and functions are now one dedicated
  1810 constant "compow" with infix syntax "^^".  Power operation on
  1811 multiplicative monoids retains syntax "^" and is now defined generic
  1812 in class power.  INCOMPATIBILITY.
  1813 
  1814 * Relation composition "R O S" now has a more standard argument order:
  1815 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1816 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1817 break, since the O_assoc rule was not rewritten like this.  Fix using
  1818 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1819 
  1820 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1821 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1822 INCOMPATIBILITY.
  1823 
  1824 * Most rules produced by inductive and datatype package have mandatory
  1825 prefixes.  INCOMPATIBILITY.
  1826 
  1827 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1828 the attribute of the same name.  Each of the theorems in the list
  1829 DERIV_intros assumes composition with an additional function and
  1830 matches a variable to the derivative, which has to be solved by the
  1831 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1832 of most elementary terms.  Former Maclauren.DERIV_tac and
  1833 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1834 INCOMPATIBILITY.
  1835 
  1836 * Code generator attributes follow the usual underscore convention:
  1837     code_unfold     replaces    code unfold
  1838     code_post       replaces    code post
  1839     etc.
  1840   INCOMPATIBILITY.
  1841 
  1842 * Renamed methods:
  1843     sizechange -> size_change
  1844     induct_scheme -> induction_schema
  1845   INCOMPATIBILITY.
  1846 
  1847 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1848 INCOMPATIBILITY, use "undefined" directly.
  1849 
  1850 * Renamed theorems:
  1851     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1852     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1853     Suc_plus1 -> Suc_eq_plus1
  1854     *anti_sym -> *antisym*
  1855     vector_less_eq_def -> vector_le_def
  1856   INCOMPATIBILITY.
  1857 
  1858 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1859 INCOMPATIBILITY.
  1860 
  1861 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1862 INCOMPATIBILITY.
  1863 
  1864 
  1865 *** HOLCF ***
  1866 
  1867 * Theory Representable defines a class "rep" of domains that are
  1868 representable (via an ep-pair) in the universal domain type "udom".
  1869 Instances are provided for all type constructors defined in HOLCF.
  1870 
  1871 * The 'new_domain' command is a purely definitional version of the
  1872 domain package, for representable domains.  Syntax is identical to the
  1873 old domain package.  The 'new_domain' package also supports indirect
  1874 recursion using previously-defined type constructors.  See
  1875 src/HOLCF/ex/New_Domain.thy for examples.
  1876 
  1877 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1878 on the left-hand side of an equation, and then performs
  1879 simplification.  Rewriting is done using rules declared with the
  1880 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1881 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1882 
  1883 * The pattern-match compiler in 'fixrec' can now handle constructors
  1884 with HOL function types.  Pattern-match combinators for the Pair
  1885 constructor are pre-configured.
  1886 
  1887 * The 'fixrec' package now produces better fixed-point induction rules
  1888 for mutually-recursive definitions:  Induction rules have conclusions
  1889 of the form "P foo bar" instead of "P <foo, bar>".
  1890 
  1891 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1892 been renamed to "below".  The name "below" now replaces "less" in many
  1893 theorem names.  (Legacy theorem names using "less" are still supported
  1894 as well.)
  1895 
  1896 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1897 patterns can be used to generate strictness rules, or to make
  1898 functions more strict (much like the bang-patterns supported by the
  1899 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1900 examples.
  1901 
  1902 
  1903 *** ML ***
  1904 
  1905 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1906 errors and run-time exceptions, including detailed source positions.
  1907 
  1908 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1909 identified entries, with some additional information such as source
  1910 position, logical grouping etc.
  1911 
  1912 * Theory and context data is now introduced by the simplified and
  1913 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1914 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1915 copy operation) is still available for some time.
  1916 
  1917 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1918 provides a high-level programming interface to synchronized state
  1919 variables with atomic update.  This works via pure function
  1920 application within a critical section -- its runtime should be as
  1921 short as possible; beware of deadlocks if critical code is nested,
  1922 either directly or indirectly via other synchronized variables!
  1923 
  1924 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1925 wraps raw ML references, explicitly indicating their non-thread-safe
  1926 behaviour.  The Isar toplevel keeps this structure open, to
  1927 accommodate Proof General as well as quick and dirty interactive
  1928 experiments with references.
  1929 
  1930 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1931 parallel tactical reasoning.
  1932 
  1933 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1934 are similar to SUBPROOF, but are slightly more flexible: only the
  1935 specified parts of the subgoal are imported into the context, and the
  1936 body tactic may introduce new subgoals and schematic variables.
  1937 
  1938 * Old tactical METAHYPS, which does not observe the proof context, has
  1939 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1940 or Subgoal.FOCUS etc.
  1941 
  1942 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1943 functors have their own ML name space there is no point to mark them
  1944 separately.)  Minor INCOMPATIBILITY.
  1945 
  1946 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1947 
  1948 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1949 INCOMPATIBILITY.
  1950 
  1951 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1952 mode, which avoids critical setmp.
  1953 
  1954 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1955 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1956 Attrib/Method.setup introduced in Isabelle2009.
  1957 
  1958 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1959 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1960 last resort.  INCOMPATIBILITY.
  1961 
  1962 * Display.pretty_thm now requires a proper context (cf. former
  1963 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1964 or even Display.pretty_thm_without_context as last resort.
  1965 INCOMPATIBILITY.
  1966 
  1967 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1968 Syntax.pretty_typ/term directly, preferably with proper context
  1969 instead of global theory.
  1970 
  1971 
  1972 *** System ***
  1973 
  1974 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1975 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1976 usedir option -q.
  1977 
  1978 * Support for additional "Isabelle components" via etc/components, see
  1979 also the system manual.
  1980 
  1981 * The isabelle makeall tool now operates on all components with
  1982 IsaMakefile, not just hardwired "logics".
  1983 
  1984 * Removed "compress" option from isabelle-process and isabelle usedir;
  1985 this is always enabled.
  1986 
  1987 * Discontinued support for Poly/ML 4.x versions.
  1988 
  1989 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1990 on a given logic image.  This requires the lighttpd webserver and is
  1991 currently supported on Linux only.
  1992 
  1993 
  1994 
  1995 New in Isabelle2009 (April 2009)
  1996 --------------------------------
  1997 
  1998 *** General ***
  1999 
  2000 * Simplified main Isabelle executables, with less surprises on
  2001 case-insensitive file-systems (such as Mac OS).
  2002 
  2003   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2004     "isatool."
  2005 
  2006   - The former "isabelle" alias for "isabelle-process" has been
  2007     removed (should rarely occur to regular users).
  2008 
  2009   - The former "isabelle-interface" and its alias "Isabelle" have been
  2010     removed (interfaces are now regular Isabelle tools).
  2011 
  2012 Within scripts and make files, the Isabelle environment variables
  2013 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2014 respectively.  (The latter are still available as legacy feature.)
  2015 
  2016 The old isabelle-interface wrapper could react in confusing ways if
  2017 the interface was uninstalled or changed otherwise.  Individual
  2018 interface tool configuration is now more explicit, see also the
  2019 Isabelle system manual.  In particular, Proof General is now available
  2020 via "isabelle emacs".
  2021 
  2022 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2023 purge installed copies of Isabelle executables and re-run "isabelle
  2024 install -p ...", or use symlinks.
  2025 
  2026 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2027 old ~/isabelle, which was slightly non-standard and apt to cause
  2028 surprises on case-insensitive file-systems (such as Mac OS).
  2029 
  2030 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2031 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2032 care is required when using older releases of Isabelle.  Note that
  2033 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2034 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2035 
  2036 * Proofs of fully specified statements are run in parallel on
  2037 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2038 a regular 4-core machine, if the initial heap space is made reasonably
  2039 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2040 
  2041 * The main reference manuals ("isar-ref", "implementation", and
  2042 "system") have been updated and extended.  Formally checked references
  2043 as hyperlinks are now available uniformly.
  2044 
  2045 
  2046 *** Pure ***
  2047 
  2048 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2049 respects.  The most important changes are listed below.  See the
  2050 Tutorial on Locales ("locales" manual) for details.
  2051 
  2052 - In locale expressions, instantiation replaces renaming.  Parameters
  2053 must be declared in a for clause.  To aid compatibility with previous
  2054 parameter inheritance, in locale declarations, parameters that are not
  2055 'touched' (instantiation position "_" or omitted) are implicitly added
  2056 with their syntax at the beginning of the for clause.
  2057 
  2058 - Syntax from abbreviations and definitions in locales is available in
  2059 locale expressions and context elements.  The latter is particularly
  2060 useful in locale declarations.
  2061 
  2062 - More flexible mechanisms to qualify names generated by locale
  2063 expressions.  Qualifiers (prefixes) may be specified in locale
  2064 expressions, and can be marked as mandatory (syntax: "name!:") or
  2065 optional (syntax "name?:").  The default depends for plain "name:"
  2066 depends on the situation where a locale expression is used: in
  2067 commands 'locale' and 'sublocale' prefixes are optional, in
  2068 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2069 implicit qualifiers derived from the parameter names of a locale are
  2070 no longer generated.
  2071 
  2072 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2073 instantiation clause in "interpretation" and "interpret" (square
  2074 brackets) is no longer available.  Use locale expressions.
  2075 
  2076 - When converting proof scripts, mandatory qualifiers in
  2077 'interpretation' and 'interpret' should be retained by default, even
  2078 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2079 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2080 in locale expressions range over a single locale instance only.
  2081 
  2082 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2083 In existing theorem specifications replace the includes element by the
  2084 respective context elements of the included locale, omitting those
  2085 that are already present in the theorem specification.  Multiple
  2086 assume elements of a locale should be replaced by a single one
  2087 involving the locale predicate.  In the proof body, declarations (most
  2088 notably theorems) may be regained by interpreting the respective
  2089 locales in the proof context as required (command "interpret").
  2090 
  2091 If using "includes" in replacement of a target solely because the
  2092 parameter types in the theorem are not as general as in the target,
  2093 consider declaring a new locale with additional type constraints on
  2094 the parameters (context element "constrains").
  2095 
  2096 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2097 
  2098 - Locale interpretation commands no longer attempt to simplify goal.
  2099 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2100 methods intro_locales and unfold_locales to clarify.
  2101 
  2102 - Locale interpretation commands no longer accept interpretation
  2103 attributes.  INCOMPATIBILITY.
  2104 
  2105 * Class declaration: so-called "base sort" must not be given in import
  2106 list any longer, but is inferred from the specification.  Particularly
  2107 in HOL, write
  2108 
  2109     class foo = ...
  2110 
  2111 instead of
  2112 
  2113     class foo = type + ...
  2114 
  2115 * Class target: global versions of theorems stemming do not carry a
  2116 parameter prefix any longer.  INCOMPATIBILITY.
  2117 
  2118 * Class 'instance' command no longer accepts attached definitions.
  2119 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2120 
  2121 * Recovered hiding of consts, which was accidentally broken in
  2122 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2123 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2124 
  2125 * Slightly more coherent Pure syntax, with updated documentation in
  2126 isar-ref manual.  Removed locales meta_term_syntax and
  2127 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2128 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2129 directly in regular applications.
  2130 
  2131 * There is a new syntactic category "float_const" for signed decimal
  2132 fractions (e.g. 123.45 or -123.45).
  2133 
  2134 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2135 interface with 'setup' command instead.
  2136 
  2137 * Command 'local_setup' is similar to 'setup', but operates on a local
  2138 theory context.
  2139 
  2140 * The 'axiomatization' command now only works within a global theory
  2141 context.  INCOMPATIBILITY.
  2142 
  2143 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2144 hypotheses.  Sorts required in the course of reasoning need to be
  2145 covered by the constraints in the initial statement, completed by the
  2146 type instance information of the background theory.  Non-trivial sort
  2147 hypotheses, which rarely occur in practice, may be specified via
  2148 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2149 
  2150   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2151 
  2152 The result contains an implicit sort hypotheses as before --
  2153 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2154 normalization.
  2155 
  2156 * Generalized Isar history, with support for linear undo, direct state
  2157 addressing etc.
  2158 
  2159 * Changed defaults for unify configuration options:
  2160 
  2161   unify_trace_bound = 50 (formerly 25)
  2162   unify_search_bound = 60 (formerly 30)
  2163 
  2164 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2165 
  2166   a) On theory merge, the last set of code equations for a particular
  2167      constant is taken (in accordance with the policy applied by other
  2168      parts of the code generator framework).
  2169 
  2170   b) Code equations stemming from explicit declarations (e.g. code
  2171      attribute) gain priority over default code equations stemming
  2172      from definition, primrec, fun etc.
  2173 
  2174 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2175 
  2176 * Unified theorem tables for both code generators.  Thus [code
  2177 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2178 
  2179 * Command 'find_consts' searches for constants based on type and name
  2180 patterns, e.g.
  2181 
  2182     find_consts "_ => bool"
  2183 
  2184 By default, matching is against subtypes, but it may be restricted to
  2185 the whole type.  Searching by name is possible.  Multiple queries are
  2186 conjunctive and queries may be negated by prefixing them with a
  2187 hyphen:
  2188 
  2189     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2190 
  2191 * New 'find_theorems' criterion "solves" matches theorems that
  2192 directly solve the current goal (modulo higher-order unification).
  2193 
  2194 * Auto solve feature for main theorem statements: whenever a new goal
  2195 is stated, "find_theorems solves" is called; any theorems that could
  2196 solve the lemma directly are listed as part of the goal state.
  2197 Cf. associated options in Proof General Isabelle settings menu,
  2198 enabled by default, with reasonable timeout for pathological cases of
  2199 higher-order unification.
  2200 
  2201 
  2202 *** Document preparation ***
  2203 
  2204 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2205 demanding keyword 'by' and supporting the full method expression
  2206 syntax just like the Isar command 'by'.
  2207 
  2208 
  2209 *** HOL ***
  2210 
  2211 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2212 points Main and Complex_Main remain as before.
  2213 
  2214 * Logic image HOL-Plain provides a minimal HOL with the most important
  2215 tools available (inductive, datatype, primrec, ...).  This facilitates
  2216 experimentation and tool development.  Note that user applications
  2217 (and library theories) should never refer to anything below theory
  2218 Main, as before.
  2219 
  2220 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2221 experimentation due to shorter build times.
  2222 
  2223 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2224 were previously part of former HOL-Complex.  Entry point Hyperreal
  2225 remains valid, but theories formerly using Complex_Main should now use
  2226 new entry point Hypercomplex.
  2227 
  2228 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2229 Posix processes.  Avoids potentially expensive forking of the ML
  2230 process.  New thread-based implementation also works on non-Unix
  2231 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2232 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2233 commands are covered in the isar-ref manual.
  2234 
  2235 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2236 sledgehammer without local ATP installation (Vampire etc.). Other
  2237 provers may be included via suitable ML wrappers, see also
  2238 src/HOL/ATP_Linkup.thy.
  2239 
  2240 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2241 menu.
  2242 
  2243 * The metis method no longer fails because the theorem is too trivial
  2244 (contains the empty clause).
  2245 
  2246 * The metis method now fails in the usual manner, rather than raising
  2247 an exception, if it determines that it cannot prove the theorem.
  2248 
  2249 * Method "coherent" implements a prover for coherent logic (see also
  2250 src/Tools/coherent.ML).
  2251 
  2252 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2253 "undefined" is the right choice to replace "arbitrary", though
  2254 logically there is no difference.  INCOMPATIBILITY.
  2255 
  2256 * Command "value" now integrates different evaluation mechanisms.  The
  2257 result of the first successful evaluation mechanism is printed.  In
  2258 square brackets a particular named evaluation mechanisms may be
  2259 specified (currently, [SML], [code] or [nbe]).  See further
  2260 src/HOL/ex/Eval_Examples.thy.
  2261 
  2262 * Normalization by evaluation now allows non-leftlinear equations.
  2263 Declare with attribute [code nbe].
  2264 
  2265 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2266 as the structured Isar versions "cases" and "induct", cf. the
  2267 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2268 are now presented as a list of individual projections
  2269 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2270 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2271 rare situations a different rule is selected --- notably nested tuple
  2272 elimination instead of former prod.exhaust: use explicit (case_tac t
  2273 rule: prod.exhaust) here.
  2274 
  2275 * Attributes "cases", "induct", "coinduct" support "del" option.
  2276 
  2277 * Removed fact "case_split_thm", which duplicates "case_split".
  2278 
  2279 * The option datatype has been moved to a new theory Option.  Renamed
  2280 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2281 
  2282 * New predicate "strict_mono" classifies strict functions on partial
  2283 orders.  With strict functions on linear orders, reasoning about
  2284 (in)equalities is facilitated by theorems "strict_mono_eq",
  2285 "strict_mono_less_eq" and "strict_mono_less".
  2286 
  2287 * Some set operations are now proper qualified constants with
  2288 authentic syntax.  INCOMPATIBILITY:
  2289 
  2290     op Int ~>   Set.Int
  2291     op Un ~>    Set.Un
  2292     INTER ~>    Set.INTER
  2293     UNION ~>    Set.UNION
  2294     Inter ~>    Set.Inter
  2295     Union ~>    Set.Union
  2296     {} ~>       Set.empty
  2297     UNIV ~>     Set.UNIV
  2298 
  2299 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2300 theory Set.
  2301 
  2302 * Auxiliary class "itself" has disappeared -- classes without any
  2303 parameter are treated as expected by the 'class' command.
  2304 
  2305 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2306 
  2307 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2308 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2309 
  2310 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2311 method "approximation".  It proves formulas on real values by using
  2312 interval arithmetic.  In the formulas are also the transcendental
  2313 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2314 allowed. For examples see
  2315 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2316 
  2317 * Theory "Reflection" now resides in HOL/Library.
  2318 
  2319 * Entry point to Word library now simply named "Word".
  2320 INCOMPATIBILITY.
  2321 
  2322 * Made source layout more coherent with logical distribution
  2323 structure:
  2324 
  2325     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2326     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2327     src/HOL/Library/GCD.thy ~> src/HOL/
  2328     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2329     src/HOL/Library/Parity.thy ~> src/HOL/
  2330     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2331     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2332     src/HOL/Real/Lubs.thy ~> src/HOL/
  2333     src/HOL/Real/PReal.thy ~> src/HOL/
  2334     src/HOL/Real/Rational.thy ~> src/HOL/
  2335     src/HOL/Real/RComplete.thy ~> src/HOL/
  2336     src/HOL/Real/RealDef.thy ~> src/HOL/
  2337     src/HOL/Real/RealPow.thy ~> src/HOL/
  2338     src/HOL/Real/Real.thy ~> src/HOL/
  2339     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2340     src/HOL/Complex/Complex.thy ~> src/HOL/
  2341     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2342     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2343     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2344     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2345     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2346     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2347     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2348     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2349     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2350     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2351     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2352     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2353     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2354     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2355     src/HOL/Real/Float ~> src/HOL/Library/
  2356     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2357     src/HOL/Real/RealVector.thy ~> src/HOL/
  2358 
  2359     src/HOL/arith_data.ML ~> src/HOL/Tools
  2360     src/HOL/hologic.ML ~> src/HOL/Tools
  2361     src/HOL/simpdata.ML ~> src/HOL/Tools
  2362     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2363     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2364     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2365     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2366     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2367     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2368     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2369 
  2370     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2371     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2372     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2373     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2374     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2375     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2376 
  2377 * If methods "eval" and "evaluation" encounter a structured proof
  2378 state with !!/==>, only the conclusion is evaluated to True (if
  2379 possible), avoiding strange error messages.
  2380 
  2381 * Method "sizechange" automates termination proofs using (a
  2382 modification of) the size-change principle.  Requires SAT solver.  See
  2383 src/HOL/ex/Termination.thy for examples.
  2384 
  2385 * Simplifier: simproc for let expressions now unfolds if bound
  2386 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2387 
  2388 * Method "arith": Linear arithmetic now ignores all inequalities when
  2389 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2390 
  2391 * New attribute "arith" for facts that should always be used
  2392 automatically by arithmetic. It is intended to be used locally in
  2393 proofs, e.g.
  2394 
  2395   assumes [arith]: "x > 0"
  2396 
  2397 Global usage is discouraged because of possible performance impact.
  2398 
  2399 * New classes "top" and "bot" with corresponding operations "top" and
  2400 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2401 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2402 
  2403 * Changed definition lemma "less_fun_def" in order to provide an
  2404 instance for preorders on functions; use lemma "less_le" instead.
  2405 INCOMPATIBILITY.
  2406 
  2407 * Theory Orderings: class "wellorder" moved here, with explicit
  2408 induction rule "less_induct" as assumption.  For instantiation of
  2409 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2410 INCOMPATIBILITY.
  2411 
  2412 * Theory Orderings: added class "preorder" as superclass of "order".
  2413 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2414 etc. slightly changed.  Some theorems named order_class.* now named
  2415 preorder_class.*.
  2416 
  2417 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2418 "diag" to "Id_on".
  2419 
  2420 * Theory Finite_Set: added a new fold combinator of type
  2421 
  2422   ('a => 'b => 'b) => 'b => 'a set => 'b
  2423 
  2424 Occasionally this is more convenient than the old fold combinator
  2425 which is now defined in terms of the new one and renamed to
  2426 fold_image.
  2427 
  2428 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2429 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2430 extended with further lemmas!).  At the moment both still exist but
  2431 the former will disappear at some point.
  2432 
  2433 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2434 class recpower.  Type-specific simp rules for various recpower types
  2435 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2436 
  2437 rat_power_0    -> power_0
  2438 rat_power_Suc  -> power_Suc
  2439 realpow_0      -> power_0
  2440 realpow_Suc    -> power_Suc
  2441 complexpow_0   -> power_0
  2442 complexpow_Suc -> power_Suc
  2443 power_poly_0   -> power_0
  2444 power_poly_Suc -> power_Suc
  2445 
  2446 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2447 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2448 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2449 of lemmas from Divides has been generalized from nat to class
  2450 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2451 renames resulting from duplicate elimination:
  2452 
  2453     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2454     zero_dvd_iff ~>         dvd_0_left_iff
  2455     dvd_0 ~>                dvd_0_right
  2456     DIVISION_BY_ZERO_DIV ~> div_by_0
  2457     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2458     mult_div ~>             div_mult_self2_is_id
  2459     mult_mod ~>             mod_mult_self2_is_0
  2460 
  2461 * Theory IntDiv: removed many lemmas that are instances of class-based
  2462 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2463 rename old lemmas as follows:
  2464 
  2465 dvd_diff               -> nat_dvd_diff
  2466 dvd_zminus_iff         -> dvd_minus_iff
  2467 mod_add1_eq            -> mod_add_eq
  2468 mod_mult1_eq           -> mod_mult_right_eq
  2469 mod_mult1_eq'          -> mod_mult_left_eq
  2470 mod_mult_distrib_mod   -> mod_mult_eq
  2471 nat_mod_add_left_eq    -> mod_add_left_eq
  2472 nat_mod_add_right_eq   -> mod_add_right_eq
  2473 nat_mod_div_trivial    -> mod_div_trivial
  2474 nat_mod_mod_trivial    -> mod_mod_trivial
  2475 zdiv_zadd_self1        -> div_add_self1
  2476 zdiv_zadd_self2        -> div_add_self2
  2477 zdiv_zmult_self1       -> div_mult_self2_is_id
  2478 zdiv_zmult_self2       -> div_mult_self1_is_id
  2479 zdvd_triv_left         -> dvd_triv_left
  2480 zdvd_triv_right        -> dvd_triv_right
  2481 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2482 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2483 zmod_zadd_left_eq      -> mod_add_left_eq
  2484 zmod_zadd_right_eq     -> mod_add_right_eq
  2485 zmod_zadd_self1        -> mod_add_self1
  2486 zmod_zadd_self2        -> mod_add_self2
  2487 zmod_zadd1_eq          -> mod_add_eq
  2488 zmod_zdiff1_eq         -> mod_diff_eq
  2489 zmod_zdvd_zmod         -> mod_mod_cancel
  2490 zmod_zmod_cancel       -> mod_mod_cancel
  2491 zmod_zmult_self1       -> mod_mult_self2_is_0
  2492 zmod_zmult_self2       -> mod_mult_self1_is_0
  2493 zmod_1                 -> mod_by_1
  2494 zdiv_1                 -> div_by_1
  2495 zdvd_abs1              -> abs_dvd_iff
  2496 zdvd_abs2              -> dvd_abs_iff
  2497 zdvd_refl              -> dvd_refl
  2498 zdvd_trans             -> dvd_trans
  2499 zdvd_zadd              -> dvd_add
  2500 zdvd_zdiff             -> dvd_diff
  2501 zdvd_zminus_iff        -> dvd_minus_iff
  2502 zdvd_zminus2_iff       -> minus_dvd_iff
  2503 zdvd_zmultD            -> dvd_mult_right
  2504 zdvd_zmultD2           -> dvd_mult_left
  2505 zdvd_zmult_mono        -> mult_dvd_mono
  2506 zdvd_0_right           -> dvd_0_right
  2507 zdvd_0_left            -> dvd_0_left_iff
  2508 zdvd_1_left            -> one_dvd
  2509 zminus_dvd_iff         -> minus_dvd_iff
  2510 
  2511 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2512 
  2513 * The real numbers offer decimal input syntax: 12.34 is translated
  2514 into 1234/10^2. This translation is not reversed upon output.
  2515 
  2516 * Theory Library/Polynomial defines an abstract type 'a poly of
  2517 univariate polynomials with coefficients of type 'a.  In addition to
  2518 the standard ring operations, it also supports div and mod.  Code
  2519 generation is also supported, using list-style constructors.
  2520 
  2521 * Theory Library/Inner_Product defines a class of real_inner for real
  2522 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2523 => real.  Class real_inner is a subclass of real_normed_vector from
  2524 theory RealVector.
  2525 
  2526 * Theory Library/Product_Vector provides instances for the product
  2527 type 'a * 'b of several classes from RealVector and Inner_Product.
  2528 Definitions of addition, subtraction, scalar multiplication, norms,
  2529 and inner products are included.
  2530 
  2531 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2532 addition to the field operations, numerals and case syntax are also
  2533 supported.
  2534 
  2535 * Theory Library/Diagonalize provides constructive version of Cantor's
  2536 first diagonalization argument.
  2537 
  2538 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2539 zlcm (for int); carried together from various gcd/lcm developements in
  2540 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2541 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2542 may recover tupled syntax as follows:
  2543 
  2544     hide (open) const gcd
  2545     abbreviation gcd where
  2546       "gcd == (%(a, b). GCD.gcd a b)"
  2547     notation (output)
  2548       GCD.gcd ("gcd '(_, _')")
  2549 
  2550 The same works for lcm, zgcd, zlcm.
  2551 
  2552 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2553 instantiations for algebraic structures.  Removed some duplicate
  2554 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2555 
  2556 * ML antiquotation @{code} takes a constant as argument and generates
  2557 corresponding code in background and inserts name of the corresponding
  2558 resulting ML value/function/datatype constructor binding in place.
  2559 All occurrences of @{code} with a single ML block are generated
  2560 simultaneously.  Provides a generic and safe interface for
  2561 instrumentalizing code generation.  See
  2562 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2563 In future you ought to refrain from ad-hoc compiling generated SML
  2564 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2565 cannot refer to constants for which user-defined serializations are
  2566 set.  Refer to the corresponding ML counterpart directly in that
  2567 cases.
  2568 
  2569 * Command 'rep_datatype': instead of theorem names the command now
  2570 takes a list of terms denoting the constructors of the type to be
  2571 represented as datatype.  The characteristic theorems have to be
  2572 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2573 have disappeared in favour of existing ones:
  2574 
  2575     unit_induct                 ~> unit.induct
  2576     prod_induct                 ~> prod.induct
  2577     sum_induct                  ~> sum.induct
  2578     Suc_Suc_eq                  ~> nat.inject
  2579     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2580 
  2581 
  2582 *** HOL-Algebra ***
  2583 
  2584 * New locales for orders and lattices where the equivalence relation
  2585 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2586 locales use a record structure with field eq for the equivalence.
  2587 
  2588 * New theory of factorial domains.
  2589 
  2590 * Units_l_inv and Units_r_inv are now simp rules by default.
  2591 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2592 and/or r_inv will now also require deletion of these lemmas.
  2593 
  2594 * Renamed the following theorems, INCOMPATIBILITY:
  2595 
  2596 UpperD ~> Upper_memD
  2597 LowerD ~> Lower_memD
  2598 least_carrier ~> least_closed
  2599 greatest_carrier ~> greatest_closed
  2600 greatest_Lower_above ~> greatest_Lower_below
  2601 one_zero ~> carrier_one_zero
  2602 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2603 
  2604 
  2605 *** HOL-Nominal ***
  2606 
  2607 * Nominal datatypes can now contain type-variables.
  2608 
  2609 * Commands 'nominal_inductive' and 'equivariance' work with local
  2610 theory targets.
  2611 
  2612 * Nominal primrec can now works with local theory targets and its
  2613 specification syntax now conforms to the general format as seen in
  2614 'inductive' etc.
  2615 
  2616 * Method "perm_simp" honours the standard simplifier attributes
  2617 (no_asm), (no_asm_use) etc.
  2618 
  2619 * The new predicate #* is defined like freshness, except that on the
  2620 left hand side can be a set or list of atoms.
  2621 
  2622 * Experimental command 'nominal_inductive2' derives strong induction
  2623 principles for inductive definitions.  In contrast to
  2624 'nominal_inductive', which can only deal with a fixed number of
  2625 binders, it can deal with arbitrary expressions standing for sets of
  2626 atoms to be avoided.  The only inductive definition we have at the
  2627 moment that needs this generalisation is the typing rule for Lets in
  2628 the algorithm W:
  2629 
  2630  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2631  -----------------------------------------------------------------
  2632          Gamma |- Let x be t1 in t2 : T2
  2633 
  2634 In this rule one wants to avoid all the binders that are introduced by
  2635 "close Gamma T1".  We are looking for other examples where this
  2636 feature might be useful.  Please let us know.
  2637 
  2638 
  2639 *** HOLCF ***
  2640 
  2641 * Reimplemented the simplification procedure for proving continuity
  2642 subgoals.  The new simproc is extensible; users can declare additional
  2643 continuity introduction rules with the attribute [cont2cont].
  2644 
  2645 * The continuity simproc now uses a different introduction rule for
  2646 solving continuity subgoals on terms with lambda abstractions.  In
  2647 some rare cases the new simproc may fail to solve subgoals that the
  2648 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2649 Potential INCOMPATIBILITY.
  2650 
  2651 * Command 'fixrec': specification syntax now conforms to the general
  2652 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2653 examples.  INCOMPATIBILITY.
  2654 
  2655 
  2656 *** ZF ***
  2657 
  2658 * Proof of Zorn's Lemma for partial orders.
  2659 
  2660 
  2661 *** ML ***
  2662 
  2663 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2664 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2665 depends on multithreading, so timouts will not work before Poly/ML
  2666 5.2.1!
  2667 
  2668 * High-level support for concurrent ML programming, see
  2669 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2670 particularly convenient to organize independent functional
  2671 computations.  The concept of "synchronized variables" provides a
  2672 higher-order interface for components with shared state, avoiding the
  2673 delicate details of mutexes and condition variables.  (Requires
  2674 Poly/ML 5.2.1 or later.)
  2675 
  2676 * ML bindings produced via Isar commands are stored within the Isar
  2677 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2678 become thread-safe and work with undo as expected (concerning
  2679 top-level bindings, not side-effects on global references).
  2680 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2681 compiler at runtime; really global bindings need to be given outside a
  2682 theory.  (Requires Poly/ML 5.2 or later.)
  2683 
  2684 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2685 context.  Top-level ML bindings are stored within the proof context in
  2686 a purely sequential fashion, disregarding the nested proof structure.
  2687 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2688 proof.  (Requires Poly/ML 5.2 or later.)
  2689 
  2690 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2691 and Method.setup, as well as Isar commands 'attribute_setup' and
  2692 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2693 existing code accordingly, or use plain 'setup' together with old
  2694 Method.add_method.
  2695 
  2696 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2697 to 'a -> thm, while results are always tagged with an authentic oracle
  2698 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2699 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2700 accordingly.  Note that extra performance may be gained by producing
  2701 the cterm carefully, avoiding slow Thm.cterm_of.
  2702 
  2703 * Simplified interface for defining document antiquotations via
  2704 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2705 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2706 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2707 examples.
  2708 
  2709 * More systematic treatment of long names, abstract name bindings, and
  2710 name space operations.  Basic operations on qualified names have been
  2711 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2712 Long_Name.append.  Old type bstring has been mostly replaced by
  2713 abstract type binding (see structure Binding), which supports precise
  2714 qualification by packages and local theory targets, as well as proper
  2715 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2716 bstring values into Binding.name, or better pass through abstract
  2717 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2718 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2719 
  2720 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2721 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2722 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2723 
  2724 * Disposed old type and term read functions (Sign.read_def_typ,
  2725 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2726 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2727 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2728 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2729 resort for legacy applications.
  2730 
  2731 * Disposed old declarations, tactics, tactic combinators that refer to
  2732 the simpset or claset of an implicit theory (such as Addsimps,
  2733 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2734 embedded ML text, or local_simpset_of with a proper context passed as
  2735 explicit runtime argument.
  2736 
  2737 * Rules and tactics that read instantiations (read_instantiate,
  2738 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2739 context, which is required for parsing and type-checking.  Moreover,
  2740 the variables are specified as plain indexnames, not string encodings
  2741 thereof.  INCOMPATIBILITY.
  2742 
  2743 * Generic Toplevel.add_hook interface allows to analyze the result of
  2744 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2745 for theorem dependency output of transactions resulting in a new
  2746 theory state.
  2747 
  2748 * ML antiquotations: block-structured compilation context indicated by
  2749 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2750 
  2751   @{binding name}                         - basic name binding
  2752   @{let ?pat = term}                      - term abbreviation (HO matching)
  2753   @{note name = fact}                     - fact abbreviation
  2754   @{thm fact}                             - singleton fact (with attributes)
  2755   @{thms fact}                            - general fact (with attributes)
  2756   @{lemma prop by method}                 - singleton goal
  2757   @{lemma prop by meth1 meth2}            - singleton goal
  2758   @{lemma prop1 ... propN by method}      - general goal
  2759   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2760   @{lemma (open) ...}                     - open derivation
  2761 
  2762 
  2763 *** System ***
  2764 
  2765 * The Isabelle "emacs" tool provides a specific interface to invoke
  2766 Proof General / Emacs, with more explicit failure if that is not
  2767 installed (the old isabelle-interface script silently falls back on
  2768 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2769 installation location of the Proof General distribution.
  2770 
  2771 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2772 the Isabelle process into a JVM/Scala application.  See
  2773 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2774 process wrapper has been discontinued.)
  2775 
  2776 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2777 
  2778 * Various status messages (with exact source position information) are
  2779 emitted, if proper markup print mode is enabled.  This allows
  2780 user-interface components to provide detailed feedback on internal
  2781 prover operations.
  2782 
  2783 
  2784 
  2785 New in Isabelle2008 (June 2008)
  2786 -------------------------------
  2787 
  2788 *** General ***
  2789 
  2790 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2791 and updated, with formally checked references as hyperlinks.
  2792 
  2793 * Theory loader: use_thy (and similar operations) no longer set the
  2794 implicit ML context, which was occasionally hard to predict and in
  2795 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2796 provides a proper context already.
  2797 
  2798 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2799 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2800 'use' within a theory file will do the job.
  2801 
  2802 * Name space merge now observes canonical order, i.e. the second space
  2803 is inserted into the first one, while existing entries in the first
  2804 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2805 swap theory imports.
  2806 
  2807 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2808 INCOMPATIBILITY in identifier syntax etc.
  2809 
  2810 * Outer syntax: string tokens no longer admit escaped white space,
  2811 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2812 white space without escapes.
  2813 
  2814 * Outer syntax: string tokens may contain arbitrary character codes
  2815 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2816 "foo_bar".
  2817 
  2818 
  2819 *** Pure ***
  2820 
  2821 * Context-dependent token translations.  Default setup reverts locally
  2822 fixed variables, and adds hilite markup for undeclared frees.
  2823 
  2824 * Unused theorems can be found using the new command 'unused_thms'.
  2825 There are three ways of invoking it:
  2826 
  2827 (1) unused_thms
  2828      Only finds unused theorems in the current theory.
  2829 
  2830 (2) unused_thms thy_1 ... thy_n -
  2831      Finds unused theorems in the current theory and all of its ancestors,
  2832      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2833 
  2834 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2835      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2836      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2837      their ancestors.
  2838 
  2839 In order to increase the readability of the list produced by
  2840 unused_thms, theorems that have been created by a particular instance
  2841 of a theory command such as 'inductive' or 'function' are considered
  2842 to belong to the same "group", meaning that if at least one theorem in
  2843 this group is used, the other theorems in the same group are no longer
  2844 reported as unused.  Moreover, if all theorems in the group are
  2845 unused, only one theorem in the group is displayed.
  2846 
  2847 Note that proof objects have to be switched on in order for
  2848 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2849 usually the case when using Proof General with the default settings).
  2850 
  2851 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2852 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2853 duplicate fact bindings, or even accidental fact duplications.  Note
  2854 that tools may maintain dynamically scoped facts systematically, using
  2855 PureThy.add_thms_dynamic.
  2856 
  2857 * Command 'hide' now allows to hide from "fact" name space as well.
  2858 
  2859 * Eliminated destructive theorem database, simpset, claset, and
  2860 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2861 update of theories within ML code.
  2862 
  2863 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2864 INCOMPATIBILITY, object-logics depending on former Pure require
  2865 additional setup PureThy.old_appl_syntax_setup; object-logics
  2866 depending on former CPure need to refer to Pure.
  2867 
  2868 * Commands 'use' and 'ML' are now purely functional, operating on
  2869 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2870 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2871 INCOMPATIBILITY.
  2872 
  2873 * Command 'setup': discontinued implicit version with ML reference.
  2874 
  2875 * Instantiation target allows for simultaneous specification of class
  2876 instance operations together with an instantiation proof.
  2877 Type-checking phase allows to refer to class operations uniformly.
  2878 See src/HOL/Complex/Complex.thy for an Isar example and
  2879 src/HOL/Library/Eval.thy for an ML example.
  2880 
  2881 * Indexing of literal facts: be more serious about including only
  2882 facts from the visible specification/proof context, but not the
  2883 background context (locale etc.).  Affects `prop` notation and method
  2884 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2885 situations.
  2886 
  2887 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2888 "(open)" option, which used to expose internal bound variables to the
  2889 proof text.
  2890 
  2891 * Isar statements: removed obsolete case "rule_context".
  2892 INCOMPATIBILITY, better use explicit fixes/assumes.
  2893 
  2894 * Locale proofs: default proof step now includes 'unfold_locales';
  2895 hence 'proof' without argument may be used to unfold locale
  2896 predicates.
  2897 
  2898 
  2899 *** Document preparation ***
  2900 
  2901 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2902 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2903 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2904 spot); renamed link color from "darkblue" to "linkcolor" (default
  2905 value unchanged, can be redefined via \definecolor); no longer sets
  2906 "a4paper" option (unnecessary or even intrusive).
  2907 
  2908 * Antiquotation @{lemma A method} proves proposition A by the given
  2909 method (either a method name or a method name plus (optional) method
  2910 arguments in parentheses) and prints A just like @{prop A}.
  2911 
  2912 
  2913 *** HOL ***
  2914 
  2915 * New primrec package.  Specification syntax conforms in style to
  2916 definition/function/....  No separate induction rule is provided.  The
  2917 "primrec" command distinguishes old-style and new-style specifications
  2918 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2919 When adjusting theories, beware: constants stemming from new-style
  2920 primrec specifications have authentic syntax.
  2921 
  2922 * Metis prover is now an order of magnitude faster, and also works
  2923 with multithreading.
  2924 
  2925 * Metis: the maximum number of clauses that can be produced from a
  2926 theorem is now given by the attribute max_clauses.  Theorems that
  2927 exceed this number are ignored, with a warning printed.
  2928 
  2929 * Sledgehammer no longer produces structured proofs by default. To
  2930 enable, declare [[sledgehammer_full = true]].  Attributes
  2931 reconstruction_modulus, reconstruction_sorts renamed
  2932 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2933 
  2934 * Method "induct_scheme" derives user-specified induction rules
  2935 from well-founded induction and completeness of patterns. This factors
  2936 out some operations that are done internally by the function package
  2937 and makes them available separately.  See
  2938 src/HOL/ex/Induction_Scheme.thy for examples.
  2939 
  2940 * More flexible generation of measure functions for termination
  2941 proofs: Measure functions can be declared by proving a rule of the
  2942 form "is_measure f" and giving it the [measure_function] attribute.
  2943 The "is_measure" predicate is logically meaningless (always true), and
  2944 just guides the heuristic.  To find suitable measure functions, the
  2945 termination prover sets up the goal "is_measure ?f" of the appropriate
  2946 type and generates all solutions by prolog-style backwards proof using
  2947 the declared rules.
  2948 
  2949 This setup also deals with rules like 
  2950 
  2951   "is_measure f ==> is_measure (list_size f)"
  2952 
  2953 which accommodates nested datatypes that recurse through lists.
  2954 Similar rules are predeclared for products and option types.
  2955 
  2956 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2957 
  2958   INCOMPATIBILITIES:
  2959 
  2960   - Definitions of overloaded constants on sets have to be replaced by
  2961     definitions on => and bool.
  2962 
  2963   - Some definitions of overloaded operators on sets can now be proved
  2964     using the definitions of the operators on => and bool.  Therefore,
  2965     the following theorems have been renamed:
  2966 
  2967       subset_def   -> subset_eq
  2968       psubset_def  -> psubset_eq
  2969       set_diff_def -> set_diff_eq
  2970       Compl_def    -> Compl_eq
  2971       Sup_set_def  -> Sup_set_eq
  2972       Inf_set_def  -> Inf_set_eq
  2973       sup_set_def  -> sup_set_eq
  2974       inf_set_def  -> inf_set_eq
  2975 
  2976   - Due to the incompleteness of the HO unification algorithm, some
  2977     rules such as subst may require manual instantiation, if some of
  2978     the unknowns in the rule is a set.
  2979 
  2980   - Higher order unification and forward proofs:
  2981     The proof pattern
  2982 
  2983       have "P (S::'a set)" <...>
  2984       then have "EX S. P S" ..
  2985 
  2986     no longer works (due to the incompleteness of the HO unification
  2987     algorithm) and must be replaced by the pattern
  2988 
  2989       have "EX S. P S"
  2990       proof
  2991         show "P S" <...>
  2992       qed
  2993 
  2994   - Calculational reasoning with subst (or similar rules):
  2995     The proof pattern
  2996 
  2997       have "P (S::'a set)" <...>
  2998       also have "S = T" <...>
  2999       finally have "P T" .
  3000 
  3001     no longer works (for similar reasons as the previous example) and
  3002     must be replaced by something like
  3003 
  3004       have "P (S::'a set)" <...>
  3005       moreover have "S = T" <...>
  3006       ultimately have "P T" by simp
  3007 
  3008   - Tactics or packages written in ML code:
  3009     Code performing pattern matching on types via
  3010 
  3011       Type ("set", [T]) => ...
  3012 
  3013     must be rewritten. Moreover, functions like strip_type or
  3014     binder_types no longer return the right value when applied to a
  3015     type of the form
  3016 
  3017       T1 => ... => Tn => U => bool
  3018 
  3019     rather than
  3020 
  3021       T1 => ... => Tn => U set
  3022 
  3023 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3024 Wellfounded_Relations to theory Wellfounded.
  3025 
  3026 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3027 
  3028 * Class finite no longer treats UNIV as class parameter.  Use class
  3029 enum from theory Library/Enum instead to achieve a similar effect.
  3030 INCOMPATIBILITY.
  3031 
  3032 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3033 and "Cons".  INCOMPATIBILITY.
  3034 
  3035 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3036 Potential INCOMPATIBILITY.
  3037 
  3038 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3039 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3040 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3041 
  3042 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3043 the same name in theory Orderings:
  3044 
  3045   less_trans
  3046   less_linear
  3047   le_imp_less_or_eq
  3048   le_less_trans
  3049   less_le_trans
  3050   less_not_sym
  3051   less_asym
  3052 
  3053 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3054 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3055 and different variable names.
  3056 
  3057 * Library/Option_ord.thy: Canonical order on option type.
  3058 
  3059 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3060 finite maps.
  3061 
  3062 * Library/Countable.thy: Type class for countable types.
  3063 
  3064 * Theory Int: The representation of numerals has changed.  The infix
  3065 operator BIT and the bit datatype with constructors B0 and B1 have
  3066 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3067 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3068 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3069 accordingly.
  3070 
  3071 * Theory Nat: definition of <= and < on natural numbers no longer
  3072 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3073 le_def and less_def have disappeared.  Consider lemmas not_less
  3074 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3075 
  3076 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3077 (whose purpose mainly is for various fold_set functionals) have been
  3078 abandoned in favor of the existing algebraic classes
  3079 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3080 lower_semilattice (resp. upper_semilattice) and linorder.
  3081 INCOMPATIBILITY.
  3082 
  3083 * Theory Transitive_Closure: induct and cases rules now declare proper
  3084 case_names ("base" and "step").  INCOMPATIBILITY.
  3085 
  3086 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3087 lattices.  The form set-specific version is available as
  3088 Inductive.lfp_ordinal_induct_set.
  3089 
  3090 * Renamed theorems "power.simps" to "power_int.simps".
  3091 INCOMPATIBILITY.
  3092 
  3093 * Class semiring_div provides basic abstract properties of semirings
  3094 with division and modulo operations.  Subsumes former class dvd_mod.
  3095 
  3096 * Merged theories IntDef, Numeral and IntArith into unified theory
  3097 Int.  INCOMPATIBILITY.
  3098 
  3099 * Theory Library/Code_Index: type "index" now represents natural
  3100 numbers rather than integers.  INCOMPATIBILITY.
  3101 
  3102 * New class "uminus" with operation "uminus" (split of from class
  3103 "minus" which now only has operation "minus", binary).
  3104 INCOMPATIBILITY.
  3105 
  3106 * Constants "card", "internal_split", "option_map" now with authentic
  3107 syntax.  INCOMPATIBILITY.
  3108 
  3109 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3110 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3111 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3112 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3113 Sup_set_def, le_def, less_def, option_map_def now with object
  3114 equality.  INCOMPATIBILITY.
  3115 
  3116 * Records. Removed K_record, and replaced it by pure lambda term
  3117 %x. c. The simplifier setup is now more robust against eta expansion.
  3118 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3119 
  3120 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3121 
  3122 * Library/ListVector: new theory of arithmetic vector operations.
  3123 
  3124 * Library/Order_Relation: new theory of various orderings as sets of
  3125 pairs.  Defines preorders, partial orders, linear orders and
  3126 well-orders on sets and on types.
  3127 
  3128 
  3129 *** ZF ***
  3130 
  3131 * Renamed some theories to allow to loading both ZF and HOL in the
  3132 same session:
  3133 
  3134   Datatype  -> Datatype_ZF
  3135   Inductive -> Inductive_ZF
  3136   Int       -> Int_ZF
  3137   IntDiv    -> IntDiv_ZF
  3138   Nat       -> Nat_ZF
  3139   List      -> List_ZF
  3140   Main      -> Main_ZF
  3141 
  3142 INCOMPATIBILITY: ZF theories that import individual theories below
  3143 Main might need to be adapted.  Regular theory Main is still
  3144 available, as trivial extension of Main_ZF.
  3145 
  3146 
  3147 *** ML ***
  3148 
  3149 * ML within Isar: antiquotation @{const name} or @{const
  3150 name(typargs)} produces statically-checked Const term.
  3151 
  3152 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3153 (of the same name).  Removed obsolete print command.
  3154 
  3155 * Removed obsolete "use_legacy_bindings" function.
  3156 
  3157 * The ``print mode'' is now a thread-local value derived from a global
  3158 template (the former print_mode reference), thus access becomes
  3159 non-critical.  The global print_mode reference is for session
  3160 management only; user-code should use print_mode_value,
  3161 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3162 
  3163 * Functions system/system_out provide a robust way to invoke external
  3164 shell commands, with propagation of interrupts (requires Poly/ML
  3165 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3166 
  3167 
  3168 *** System ***
  3169 
  3170 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3171 in accordance with Proof General 3.7, which prefers GNU emacs.
  3172 
  3173 * isatool tty runs Isabelle process with plain tty interaction;
  3174 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3175 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3176 
  3177 * isatool browser now works with Cygwin as well, using general
  3178 "javapath" function defined in Isabelle process environment.
  3179 
  3180 * YXML notation provides a simple and efficient alternative to
  3181 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3182 isatool yxml as described in the Isabelle system manual.
  3183 
  3184 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3185 provides general wrapper for managing an Isabelle process in a robust
  3186 fashion, with ``cooked'' output from stdin/stderr.
  3187 
  3188 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3189 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3190 
  3191 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3192 way of changing the user's settings is via
  3193 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3194 script.
  3195 
  3196 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3197 cores of the underlying machine, which is a good starting point for
  3198 optimal performance tuning.  The corresponding usedir option -M allows
  3199 "max" as an alias for "0".  WARNING: does not work on certain versions
  3200 of Mac OS (with Poly/ML 5.1).
  3201 
  3202 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3203 adverse effect of Isabelle flooding interactive front-ends (notably
  3204 ProofGeneral / XEmacs).
  3205 
  3206 
  3207 
  3208 New in Isabelle2007 (November 2007)
  3209 -----------------------------------
  3210 
  3211 *** General ***
  3212 
  3213 * More uniform information about legacy features, notably a
  3214 warning/error of "Legacy feature: ...", depending on the state of the
  3215 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3216 legacy features will disappear eventually.
  3217 
  3218 * Theory syntax: the header format ``theory A = B + C:'' has been
  3219 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3220 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3221 
  3222 * Theory syntax: the old non-Isar theory file format has been
  3223 discontinued altogether.  Note that ML proof scripts may still be used
  3224 with Isar theories; migration is usually quite simple with the ML
  3225 function use_legacy_bindings.  INCOMPATIBILITY.
  3226 
  3227 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3228 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3229 quotes.
  3230 
  3231 * Theory loader: be more serious about observing the static theory
  3232 header specifications (including optional directories), but not the
  3233 accidental file locations of previously successful loads.  The strict
  3234 update policy of former update_thy is now already performed by
  3235 use_thy, so the former has been removed; use_thys updates several
  3236 theories simultaneously, just as 'imports' within a theory header
  3237 specification, but without merging the results.  Potential
  3238 INCOMPATIBILITY: may need to refine theory headers and commands
  3239 ROOT.ML which depend on load order.
  3240 
  3241 * Theory loader: optional support for content-based file
  3242 identification, instead of the traditional scheme of full physical
  3243 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3244 (cf. the system manual).  The new scheme allows to work with
  3245 non-finished theories in persistent session images, such that source
  3246 files may be moved later on without requiring reloads.
  3247 
  3248 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3249 file (with the same base name as the theory) are considered a legacy
  3250 feature, which will disappear eventually. Even now, the theory loader
  3251 no longer maintains dependencies on such files.
  3252 
  3253 * Syntax: the scope for resolving ambiguities via type-inference is
  3254 now limited to individual terms, instead of whole simultaneous
  3255 specifications as before. This greatly reduces the complexity of the
  3256 syntax module and improves flexibility by separating parsing and
  3257 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3258 'fixes' etc.) are required in rare situations.
  3259 
  3260 * Syntax: constants introduced by new-style packages ('definition',
  3261 'abbreviation' etc.) are passed through the syntax module in
  3262 ``authentic mode''. This means that associated mixfix annotations
  3263 really stick to such constants, independently of potential name space
  3264 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3265 trees are represented slightly differently, may need to adapt syntax
  3266 translations accordingly. Use CONST marker in 'translations' and
  3267 @{const_syntax} antiquotation in 'parse_translation' etc.
  3268 
  3269 * Legacy goal package: reduced interface to the bare minimum required
  3270 to keep existing proof scripts running.  Most other user-level
  3271 functions are now part of the OldGoals structure, which is *not* open
  3272 by default (consider isatool expandshort before open OldGoals).
  3273 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3274 these tend to cause confusion about the actual goal (!) context being
  3275 used here, which is not necessarily the same as the_context().
  3276 
  3277 * Command 'find_theorems': supports "*" wild-card in "name:"
  3278 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3279 support a specific search form (see ProofGeneral/CHANGES).
  3280 
  3281 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3282 by default, which means that "prems" (and also "fixed variables") are
  3283 suppressed from proof state output.  Note that the ProofGeneral
  3284 settings mechanism allows to change and save options persistently, but
  3285 older versions of Isabelle will fail to start up if a negative prems
  3286 limit is imposed.
  3287 
  3288 * Local theory targets may be specified by non-nested blocks of
  3289 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3290 contain definitions, theorems etc., including any derived mechanism
  3291 that has been implemented on top of these primitives.  This concept
  3292 generalizes the existing ``theorem (in ...)'' towards more versatility
  3293 and scalability.
  3294 
  3295 * Proof General interface: proper undo of final 'end' command;
  3296 discontinued Isabelle/classic mode (ML proof scripts).
  3297 
  3298 
  3299 *** Document preparation ***
  3300 
  3301 * Added antiquotation @{theory name} which prints the given name,
  3302 after checking that it refers to a valid ancestor theory in the
  3303 current context.
  3304 
  3305 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3306 check the given source text as ML type/structure, printing verbatim.
  3307 
  3308 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3309 "c args == rhs" given in the current context.  (Any number of
  3310 arguments may be given on the LHS.)
  3311 
  3312 
  3313 *** Pure ***
  3314 
  3315 * The 'class' package offers a combination of axclass and locale to
  3316 achieve Haskell-like type classes in Isabelle.  Definitions and
  3317 theorems within a class context produce both relative results (with
  3318 implicit parameters according to the locale context), and polymorphic
  3319 constants with qualified polymorphism (according to the class
  3320 context).  Within the body context of a 'class' target, a separate
  3321 syntax layer ("user space type system") takes care of converting
  3322 between global polymorphic consts and internal locale representation.
  3323 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3324 "isatool doc classes" provides a tutorial.
  3325 
  3326 * Generic code generator framework allows to generate executable
  3327 code for ML and Haskell (including Isabelle classes).  A short usage
  3328 sketch:
  3329 
  3330     internal compilation:
  3331         export_code <list of constants (term syntax)> in SML
  3332     writing SML code to a file:
  3333         export_code <list of constants (term syntax)> in SML <filename>
  3334     writing OCaml code to a file:
  3335         export_code <list of constants (term syntax)> in OCaml <filename>
  3336     writing Haskell code to a bunch of files:
  3337         export_code <list of constants (term syntax)> in Haskell <filename>
  3338 
  3339     evaluating closed propositions to True/False using code generation:
  3340         method ``eval''
  3341 
  3342 Reasonable default setup of framework in HOL.
  3343 
  3344 Theorem attributs for selecting and transforming function equations theorems:
  3345 
  3346     [code fun]:        select a theorem as function equation for a specific constant
  3347     [code fun del]:    deselect a theorem as function equation for a specific constant
  3348     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3349     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3350 
  3351 User-defined serializations (target in {SML, OCaml, Haskell}):
  3352 
  3353     code_const <and-list of constants (term syntax)>
  3354       {(target) <and-list of const target syntax>}+
  3355 
  3356     code_type <and-list of type constructors>
  3357       {(target) <and-list of type target syntax>}+
  3358 
  3359     code_instance <and-list of instances>
  3360       {(target)}+
  3361         where instance ::= <type constructor> :: <class>
  3362 
  3363     code_class <and_list of classes>
  3364       {(target) <and-list of class target syntax>}+
  3365         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3366 
  3367 code_instance and code_class only are effective to target Haskell.
  3368 
  3369 For example usage see src/HOL/ex/Codegenerator.thy and
  3370 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3371 generation from Isabelle/HOL theories is available via "isatool doc
  3372 codegen".
  3373 
  3374 * Code generator: consts in 'consts_code' Isar commands are now
  3375 referred to by usual term syntax (including optional type
  3376 annotations).
  3377 
  3378 * Command 'no_translations' removes translation rules from theory
  3379 syntax.
  3380 
  3381 * Overloaded definitions are now actually checked for acyclic
  3382 dependencies.  The overloading scheme is slightly more general than
  3383 that of Haskell98, although Isabelle does not demand an exact
  3384 correspondence to type class and instance declarations.
  3385 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3386 exotic versions of overloading -- at the discretion of the user!
  3387 
  3388 Polymorphic constants are represented via type arguments, i.e. the
  3389 instantiation that matches an instance against the most general
  3390 declaration given in the signature.  For example, with the declaration
  3391 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3392 as c(nat).  Overloading is essentially simultaneous structural
  3393 recursion over such type arguments.  Incomplete specification patterns
  3394 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3395 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3396 Command 'print_theory' outputs the normalized system of recursive
  3397 equations, see section "definitions".
  3398 
  3399 * Configuration options are maintained within the theory or proof
  3400 context (with name and type bool/int/string), providing a very simple
  3401 interface to a poor-man's version of general context data.  Tools may
  3402 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3403 these values using Config.get etc.  Users may change options via an
  3404 associated attribute of the same name.  This form of context
  3405 declaration works particularly well with commands 'declare' or
  3406 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3407 very easy to avoid global references, which would not observe Isar
  3408 toplevel undo/redo and fail to work with multithreading.
  3409 
  3410 Various global ML references of Pure and HOL have been turned into
  3411 configuration options:
  3412 
  3413   Unify.search_bound		unify_search_bound
  3414   Unify.trace_bound		unify_trace_bound
  3415   Unify.trace_simp		unify_trace_simp
  3416   Unify.trace_types		unify_trace_types
  3417   Simplifier.simp_depth_limit	simp_depth_limit
  3418   Blast.depth_limit		blast_depth_limit
  3419   DatatypeProp.dtK		datatype_distinctness_limit
  3420   fast_arith_neq_limit  	fast_arith_neq_limit
  3421   fast_arith_split_limit	fast_arith_split_limit
  3422 
  3423 * Named collections of theorems may be easily installed as context
  3424 data using the functor NamedThmsFun (see also
  3425 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3426 attributes; there is also a toplevel print command.  This facility is
  3427 just a common case of general context data, which is the preferred way
  3428 for anything more complex than just a list of facts in canonical
  3429 order.
  3430 
  3431 * Isar: command 'declaration' augments a local theory by generic
  3432 declaration functions written in ML.  This enables arbitrary content
  3433 being added to the context, depending on a morphism that tells the
  3434 difference of the original declaration context wrt. the application
  3435 context encountered later on.
  3436 
  3437 * Isar: proper interfaces for simplification procedures.  Command
  3438 'simproc_setup' declares named simprocs (with match patterns, and body
  3439 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3440 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3441 
  3442 * Isar: an extra pair of brackets around attribute declarations
  3443 abbreviates a theorem reference involving an internal dummy fact,
  3444 which will be ignored later --- only the effect of the attribute on
  3445 the background context will persist.  This form of in-place
  3446 declarations is particularly useful with commands like 'declare' and
  3447 'using', for example ``have A using [[simproc a]] by simp''.
  3448 
  3449 * Isar: method "assumption" (and implicit closing of subproofs) now
  3450 takes simple non-atomic goal assumptions into account: after applying
  3451 an assumption as a rule the resulting subgoals are solved by atomic
  3452 assumption steps.  This is particularly useful to finish 'obtain'
  3453 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3454 without referring to the original premise "!!x. P x ==> thesis" in the
  3455 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3456 more permissive.
  3457 
  3458 * Isar: implicit use of prems from the Isar proof context is
  3459 considered a legacy feature.  Common applications like ``have A .''
  3460 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3461 referencing facts explicitly here improves readability and
  3462 maintainability of proof texts.
  3463 
  3464 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3465 the obtained context from the course of reasoning!  For example:
  3466 
  3467   assume "EX x y. A x & B y"   -- "any previous fact"
  3468   then guess x and y by clarify
  3469 
  3470 This technique is potentially adventurous, depending on the facts and
  3471 proof tools being involved here.
  3472 
  3473 * Isar: known facts from the proof context may be specified as literal
  3474 propositions, using ASCII back-quote syntax.  This works wherever
  3475 named facts used to be allowed so far, in proof commands, proof
  3476 methods, attributes etc.  Literal facts are retrieved from the context
  3477 according to unification of type and term parameters.  For example,
  3478 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3479 theorems in the current context, then these are valid literal facts:
  3480 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3481 
  3482 There is also a proof method "fact" which does the same composition
  3483 for explicit goal states, e.g. the following proof texts coincide with
  3484 certain special cases of literal facts:
  3485 
  3486   have "A" by fact                 ==  note `A`
  3487   have "A ==> B" by fact           ==  note `A ==> B`
  3488   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3489   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3490 
  3491 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3492 outer syntax.  Thus symbolic identifiers may be used without
  3493 additional white space in declarations like this: ``assume *: A''.
  3494 
  3495 * Isar: 'print_facts' prints all local facts of the current context,
  3496 both named and unnamed ones.
  3497 
  3498 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3499 
  3500   def x == "t" and y == "u"
  3501 
  3502 * Isar: added command 'unfolding', which is structurally similar to
  3503 'using', but affects both the goal state and facts by unfolding given
  3504 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3505 'unfolded' attribute may be replaced by first-class proof text.
  3506 
  3507 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3508 and command 'unfolding' now all support object-level equalities
  3509 (potentially conditional).  The underlying notion of rewrite rule is
  3510 analogous to the 'rule_format' attribute, but *not* that of the
  3511 Simplifier (which is usually more generous).
  3512 
  3513 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3514 premises of a theorem by n. Useful in conjunction with drule.
  3515 
  3516 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3517 method expression within a sandbox consisting of the first N
  3518 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3519 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3520 simplifies all new goals that emerge from applying rule foo to the
  3521 originally first one.
  3522 
  3523 * Isar: schematic goals are no longer restricted to higher-order
  3524 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3525 expected.
  3526 
  3527 * Isar: the conclusion of a long theorem statement is now either
  3528 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3529 (essentially a disjunction of cases with local parameters and
  3530 assumptions).  The latter allows to express general elimination rules
  3531 adequately; in this notation common elimination rules look like this:
  3532 
  3533   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3534     assumes "EX x. P x"
  3535     obtains x where "P x"
  3536 
  3537   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3538     assumes "A & B"
  3539     obtains A and B
  3540 
  3541   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3542     assumes "A | B"
  3543     obtains
  3544       A
  3545     | B
  3546 
  3547 The subsequent classical rules even refer to the formal "thesis"
  3548 explicitly:
  3549 
  3550   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3551     obtains "~ thesis"
  3552 
  3553   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3554     obtains "thesis ==> something"
  3555 
  3556 The actual proof of an 'obtains' statement is analogous to that of the
  3557 Isar proof element 'obtain', only that there may be several cases.
  3558 Optional case names may be specified in parentheses; these will be
  3559 available both in the present proof and as annotations in the
  3560 resulting rule, for later use with the 'cases' method (cf. attribute
  3561 case_names).
  3562 
  3563 * Isar: the assumptions of a long theorem statement are available as
  3564 "assms" fact in the proof context.  This is more appropriate than the
  3565 (historical) "prems", which refers to all assumptions of the current
  3566 context, including those from the target locale, proof body etc.
  3567 
  3568 * Isar: 'print_statement' prints theorems from the current theory or
  3569 proof context in long statement form, according to the syntax of a
  3570 top-level lemma.
  3571 
  3572 * Isar: 'obtain' takes an optional case name for the local context
  3573 introduction rule (default "that").
  3574 
  3575 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3576 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3577 to occur.
  3578 
  3579 * Pure: syntax "CONST name" produces a fully internalized constant
  3580 according to the current context.  This is particularly useful for
  3581 syntax translations that should refer to internal constant
  3582 representations independently of name spaces.
  3583 
  3584 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3585 instead of "FOO ". This allows multiple binder declarations to coexist
  3586 in the same context.  INCOMPATIBILITY.
  3587 
  3588 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3589 primitive that also works in a locale context (both for constants and
  3590 fixed variables). Type declaration and internal syntactic representation
  3591 of given constants retrieved from the context. Likewise, the
  3592 'no_notation' command allows to remove given syntax annotations from the
  3593 current context.
  3594 
  3595 * Isar/locales: new derived specification elements 'axiomatization',
  3596 'definition', 'abbreviation', which support type-inference, admit
  3597 object-level specifications (equality, equivalence).  See also the
  3598 isar-ref manual.  Examples:
  3599 
  3600   axiomatization
  3601     eq  (infix "===" 50) where
  3602     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3603 
  3604   definition "f x y = x + y + 1"
  3605   definition g where "g x = f x x"
  3606 
  3607   abbreviation
  3608     neq  (infix "=!=" 50) where
  3609     "x =!= y == ~ (x === y)"
  3610 
  3611 These specifications may be also used in a locale context.  Then the
  3612 constants being introduced depend on certain fixed parameters, and the
  3613 constant name is qualified by the locale base name.  An internal
  3614 abbreviation takes care for convenient input and output, making the
  3615 parameters implicit and using the original short name.  See also
  3616 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3617 entities from a monomorphic theory.
  3618 
  3619 Presently, abbreviations are only available 'in' a target locale, but
  3620 not inherited by general import expressions.  Also note that
  3621 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3622 'translations' in common applications.  The "no_abbrevs" print mode
  3623 prevents folding of abbreviations in term output.
  3624 
  3625 Concrete syntax is attached to specified constants in internal form,
  3626 independently of name spaces.  The parse tree representation is
  3627 slightly different -- use 'notation' instead of raw 'syntax', and
  3628 'translations' with explicit "CONST" markup to accommodate this.
  3629 
  3630 * Pure/Isar: unified syntax for new-style specification mechanisms
  3631 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3632 full type inference and dummy patterns ("_").  For example:
  3633 
  3634   definition "K x _ = x"
  3635 
  3636   inductive conj for A B
  3637   where "A ==> B ==> conj A B"
  3638 
  3639 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3640 the current context.  Print mode "no_abbrevs" prevents inversion of
  3641 abbreviations on output.
  3642 
  3643 * Isar/locales: improved parameter handling: use of locales "var" and
  3644 "struct" no longer necessary; - parameter renamings are no longer
  3645 required to be injective.  For example, this allows to define
  3646 endomorphisms as locale endom = homom mult mult h.
  3647 
  3648 * Isar/locales: changed the way locales with predicates are defined.
  3649 Instead of accumulating the specification, the imported expression is
  3650 now an interpretation.  INCOMPATIBILITY: different normal form of
  3651 locale expressions.  In particular, in interpretations of locales with
  3652 predicates, goals repesenting already interpreted fragments are not
  3653 removed automatically.  Use methods `intro_locales' and
  3654 `unfold_locales'; see below.
  3655 
  3656 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3657 provide backward reasoning on locales predicates.  The methods are
  3658 aware of interpretations and discharge corresponding goals.
  3659 `intro_locales' is less aggressive then `unfold_locales' and does not
  3660 unfold predicates to assumptions.
  3661 
  3662 * Isar/locales: the order in which locale fragments are accumulated
  3663 has changed.  This enables to override declarations from fragments due
  3664 to interpretations -- for example, unwanted simp rules.
  3665 
  3666 * Isar/locales: interpretation in theories and proof contexts has been
  3667 extended.  One may now specify (and prove) equations, which are
  3668 unfolded in interpreted theorems.  This is useful for replacing
  3669 defined concepts (constants depending on locale parameters) by
  3670 concepts already existing in the target context.  Example:
  3671 
  3672   interpretation partial_order ["op <= :: [int, int] => bool"]
  3673     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3674 
  3675 Typically, the constant `partial_order.less' is created by a
  3676 definition specification element in the context of locale
  3677 partial_order.
  3678 
  3679 * Method "induct": improved internal context management to support
  3680 local fixes and defines on-the-fly. Thus explicit meta-level
  3681 connectives !!  and ==> are rarely required anymore in inductive goals
  3682 (using object-logic connectives for this purpose has been long
  3683 obsolete anyway). Common proof patterns are explained in
  3684 src/HOL/Induct/Common_Patterns.thy, see also
  3685 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3686 examples.
  3687 
  3688 * Method "induct": improved handling of simultaneous goals. Instead of
  3689 introducing object-level conjunction, the statement is now split into
  3690 several conclusions, while the corresponding symbolic cases are nested
  3691 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3692 see src/HOL/Induct/Common_Patterns.thy, for example.
  3693 
  3694 * Method "induct": mutual induction rules are now specified as a list
  3695 of rule sharing the same induction cases. HOL packages usually provide
  3696 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3697 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3698 mutual induction rules differently, i.e. like this:
  3699 
  3700   (induct rule: foo_bar.inducts)
  3701   (induct set: foo bar)
  3702   (induct pred: foo bar)
  3703   (induct type: foo bar)
  3704 
  3705 The ML function ProjectRule.projections turns old-style rules into the
  3706 new format.
  3707 
  3708 * Method "coinduct": dual of induction, see
  3709 src/HOL/Library/Coinductive_List.thy for various examples.
  3710 
  3711 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3712 considered a legacy feature.
  3713 
  3714 * Attribute "symmetric" produces result with standardized schematic
  3715 variables (index 0).  Potential INCOMPATIBILITY.
  3716 
  3717 * Simplifier: by default the simplifier trace only shows top level
  3718 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3719 default. Thus there is less danger of being flooded by the trace. The
  3720 trace indicates where parts have been suppressed.
  3721   
  3722 * Provers/classical: removed obsolete classical version of elim_format
  3723 attribute; classical elim/dest rules are now treated uniformly when
  3724 manipulating the claset.
  3725 
  3726 * Provers/classical: stricter checks to ensure that supplied intro,
  3727 dest and elim rules are well-formed; dest and elim rules must have at
  3728 least one premise.
  3729 
  3730 * Provers/classical: attributes dest/elim/intro take an optional
  3731 weight argument for the rule (just as the Pure versions).  Weights are
  3732 ignored by automated tools, but determine the search order of single
  3733 rule steps.
  3734 
  3735 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3736 where the body does not mention the bound variable.  Note that dummy
  3737 patterns implicitly depend on their context of bounds, which makes
  3738 "{_. _}" match any set comprehension as expected.  Potential
  3739 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3740 constant "_idtdummy" in the binding position.
  3741 
  3742 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3743 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3744 for example "A -> B" => "Pi A (%_. B)".
  3745 
  3746 * Pure: 'class_deps' command visualizes the subclass relation, using
  3747 the graph browser tool.
  3748 
  3749 * Pure: 'print_theory' now suppresses certain internal declarations by
  3750 default; use '!' option for full details.
  3751 
  3752 
  3753 *** HOL ***
  3754 
  3755 * Method "metis" proves goals by applying the Metis general-purpose
  3756 resolution prover (see also http://gilith.com/software/metis/).
  3757 Examples are in the directory MetisExamples.  WARNING: the
  3758 Isabelle/HOL-Metis integration does not yet work properly with
  3759 multi-threading.
  3760   
  3761 * Command 'sledgehammer' invokes external automatic theorem provers as
  3762 background processes.  It generates calls to the "metis" method if
  3763 successful. These can be pasted into the proof.  Users do not have to
  3764 wait for the automatic provers to return.  WARNING: does not really
  3765 work with multi-threading.
  3766 
  3767 * New "auto_quickcheck" feature tests outermost goal statements for
  3768 potential counter-examples.  Controlled by ML references
  3769 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3770 5000 milliseconds).  Fails silently if statements is outside of
  3771 executable fragment, or any other codgenerator problem occurs.
  3772 
  3773 * New constant "undefined" with axiom "undefined x = undefined".
  3774 
  3775 * Added class "HOL.eq", allowing for code generation with polymorphic
  3776 equality.
  3777 
  3778 * Some renaming of class constants due to canonical name prefixing in
  3779 the new 'class' package:
  3780 
  3781     HOL.abs ~> HOL.abs_class.abs
  3782     HOL.divide ~> HOL.divide_class.divide
  3783     0 ~> HOL.zero_class.zero
  3784     1 ~> HOL.one_class.one
  3785     op + ~> HOL.plus_class.plus
  3786     op - ~> HOL.minus_class.minus
  3787     uminus ~> HOL.minus_class.uminus
  3788     op * ~> HOL.times_class.times
  3789     op < ~> HOL.ord_class.less
  3790     op <= > HOL.ord_class.less_eq
  3791     Nat.power ~> Power.power_class.power
  3792     Nat.size ~> Nat.size_class.size
  3793     Numeral.number_of ~> Numeral.number_class.number_of
  3794     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3795     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3796     Orderings.min ~> Orderings.ord_class.min
  3797     Orderings.max ~> Orderings.ord_class.max
  3798     Divides.op div ~> Divides.div_class.div
  3799     Divides.op mod ~> Divides.div_class.mod
  3800     Divides.op dvd ~> Divides.div_class.dvd
  3801 
  3802 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3803 
  3804 a) User-defined constants using any of the names "plus", "minus",
  3805 "times", "less" or "less_eq". The standard syntax translations for
  3806 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3807 names.
  3808 
  3809 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3810 INCOMPATIBILITY: use more specific names.
  3811 
  3812 c) Permutative equations (e.g. "a + b = b + a")
  3813 Since the change of names also changes the order of terms, permutative
  3814 rewrite rules may get applied in a different order. Experience shows
  3815 that this is rarely the case (only two adaptions in the whole Isabelle
  3816 distribution).  INCOMPATIBILITY: rewrite proofs
  3817 
  3818 d) ML code directly refering to constant names
  3819 This in general only affects hand-written proof tactics, simprocs and
  3820 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3821 Consider using @{const_name} antiquotation.
  3822 
  3823 * New class "default" with associated constant "default".
  3824 
  3825 * Function "sgn" is now overloaded and available on int, real, complex
  3826 (and other numeric types), using class "sgn".  Two possible defs of
  3827 sgn are given as equational assumptions in the classes sgn_if and
  3828 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3829 INCOMPATIBILITY.
  3830 
  3831 * Locale "partial_order" now unified with class "order" (cf. theory
  3832 Orderings), added parameter "less".  INCOMPATIBILITY.
  3833 
  3834 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3835 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3836 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3837 
  3838 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3839 changed order of proof goals in instance proofs.
  3840 
  3841 * The transitivity reasoner for partial and linear orders is set up
  3842 for classes "order" and "linorder".  Instances of the reasoner are available
  3843 in all contexts importing or interpreting the corresponding locales.
  3844 Method "order" invokes the reasoner separately; the reasoner
  3845 is also integrated with the Simplifier as a solver.  Diagnostic
  3846 command 'print_orders' shows the available instances of the reasoner
  3847 in the current context.
  3848 
  3849 * Localized monotonicity predicate in theory "Orderings"; integrated
  3850 lemmas max_of_mono and min_of_mono with this predicate.
  3851 INCOMPATIBILITY.
  3852 
  3853 * Formulation of theorem "dense" changed slightly due to integration
  3854 with new class dense_linear_order.
  3855 
  3856 * Uniform lattice theory development in HOL.
  3857 
  3858     constants "meet" and "join" now named "inf" and "sup"
  3859     constant "Meet" now named "Inf"
  3860 
  3861     classes "meet_semilorder" and "join_semilorder" now named
  3862       "lower_semilattice" and "upper_semilattice"
  3863     class "lorder" now named "lattice"
  3864     class "comp_lat" now named "complete_lattice"
  3865 
  3866     Instantiation of lattice classes allows explicit definitions
  3867     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3868 
  3869   INCOMPATIBILITY.  Theorem renames:
  3870 
  3871     meet_left_le            ~> inf_le1
  3872     meet_right_le           ~> inf_le2
  3873     join_left_le            ~> sup_ge1
  3874     join_right_le           ~> sup_ge2
  3875     meet_join_le            ~> inf_sup_ord
  3876     le_meetI                ~> le_infI
  3877     join_leI                ~> le_supI
  3878     le_meet                 ~> le_inf_iff
  3879     le_join                 ~> ge_sup_conv
  3880     meet_idempotent         ~> inf_idem
  3881     join_idempotent         ~> sup_idem
  3882     meet_comm               ~> inf_commute
  3883     join_comm               ~> sup_commute
  3884     meet_leI1               ~> le_infI1
  3885     meet_leI2               ~> le_infI2
  3886     le_joinI1               ~> le_supI1
  3887     le_joinI2               ~> le_supI2
  3888     meet_assoc              ~> inf_assoc
  3889     join_assoc              ~> sup_assoc
  3890     meet_left_comm          ~> inf_left_commute
  3891     meet_left_idempotent    ~> inf_left_idem
  3892     join_left_comm          ~> sup_left_commute
  3893     join_left_idempotent    ~> sup_left_idem
  3894     meet_aci                ~> inf_aci
  3895     join_aci                ~> sup_aci
  3896     le_def_meet             ~> le_iff_inf
  3897     le_def_join             ~> le_iff_sup
  3898     join_absorp2            ~> sup_absorb2
  3899     join_absorp1            ~> sup_absorb1
  3900     meet_absorp1            ~> inf_absorb1
  3901     meet_absorp2            ~> inf_absorb2
  3902     meet_join_absorp        ~> inf_sup_absorb
  3903     join_meet_absorp        ~> sup_inf_absorb
  3904     distrib_join_le         ~> distrib_sup_le
  3905     distrib_meet_le         ~> distrib_inf_le
  3906 
  3907     add_meet_distrib_left   ~> add_inf_distrib_left
  3908     add_join_distrib_left   ~> add_sup_distrib_left
  3909     is_join_neg_meet        ~> is_join_neg_inf
  3910     is_meet_neg_join        ~> is_meet_neg_sup
  3911     add_meet_distrib_right  ~> add_inf_distrib_right
  3912     add_join_distrib_right  ~> add_sup_distrib_right
  3913     add_meet_join_distribs  ~> add_sup_inf_distribs
  3914     join_eq_neg_meet        ~> sup_eq_neg_inf
  3915     meet_eq_neg_join        ~> inf_eq_neg_sup
  3916     add_eq_meet_join        ~> add_eq_inf_sup
  3917     meet_0_imp_0            ~> inf_0_imp_0
  3918     join_0_imp_0            ~> sup_0_imp_0
  3919     meet_0_eq_0             ~> inf_0_eq_0
  3920     join_0_eq_0             ~> sup_0_eq_0
  3921     neg_meet_eq_join        ~> neg_inf_eq_sup
  3922     neg_join_eq_meet        ~> neg_sup_eq_inf
  3923     join_eq_if              ~> sup_eq_if
  3924 
  3925     mono_meet               ~> mono_inf
  3926     mono_join               ~> mono_sup
  3927     meet_bool_eq            ~> inf_bool_eq
  3928     join_bool_eq            ~> sup_bool_eq
  3929     meet_fun_eq             ~> inf_fun_eq
  3930     join_fun_eq             ~> sup_fun_eq
  3931     meet_set_eq             ~> inf_set_eq
  3932     join_set_eq             ~> sup_set_eq
  3933     meet1_iff               ~> inf1_iff
  3934     meet2_iff               ~> inf2_iff
  3935     meet1I                  ~> inf1I
  3936     meet2I                  ~> inf2I
  3937     meet1D1                 ~> inf1D1
  3938     meet2D1                 ~> inf2D1
  3939     meet1D2                 ~> inf1D2
  3940     meet2D2                 ~> inf2D2
  3941     meet1E                  ~> inf1E
  3942     meet2E                  ~> inf2E
  3943     join1_iff               ~> sup1_iff
  3944     join2_iff               ~> sup2_iff
  3945     join1I1                 ~> sup1I1
  3946     join2I1                 ~> sup2I1
  3947     join1I1                 ~> sup1I1
  3948     join2I2                 ~> sup1I2
  3949     join1CI                 ~> sup1CI
  3950     join2CI                 ~> sup2CI
  3951     join1E                  ~> sup1E
  3952     join2E                  ~> sup2E
  3953 
  3954     is_meet_Meet            ~> is_meet_Inf
  3955     Meet_bool_def           ~> Inf_bool_def
  3956     Meet_fun_def            ~> Inf_fun_def
  3957     Meet_greatest           ~> Inf_greatest
  3958     Meet_lower              ~> Inf_lower
  3959     Meet_set_def            ~> Inf_set_def
  3960 
  3961     Sup_def                 ~> Sup_Inf
  3962     Sup_bool_eq             ~> Sup_bool_def
  3963     Sup_fun_eq              ~> Sup_fun_def
  3964     Sup_set_eq              ~> Sup_set_def
  3965 
  3966     listsp_meetI            ~> listsp_infI
  3967     listsp_meet_eq          ~> listsp_inf_eq
  3968 
  3969     meet_min                ~> inf_min
  3970     join_max                ~> sup_max
  3971 
  3972 * Added syntactic class "size"; overloaded constant "size" now has
  3973 type "'a::size ==> bool"
  3974 
  3975 * Internal reorganisation of `size' of datatypes: size theorems
  3976 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3977 simplification rules by default!); theorems "prod.size" now named
  3978 "*.size".
  3979 
  3980 * Class "div" now inherits from class "times" rather than "type".
  3981 INCOMPATIBILITY.
  3982 
  3983 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3984 Linorder etc.  have disappeared; operations defined in terms of
  3985 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3986 
  3987 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3988 
  3989 * HOL-Word: New extensive library and type for generic, fixed size
  3990 machine words, with arithemtic, bit-wise, shifting and rotating
  3991 operations, reflection into int, nat, and bool lists, automation for
  3992 linear arithmetic (by automatic reflection into nat or int), including
  3993 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3994 arithmetic type classes, supporting automatic simplification of
  3995 numerals on all operations.
  3996 
  3997 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3998 
  3999 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4000 
  4001 * Code generator library theories:
  4002   - Code_Integer represents HOL integers by big integer literals in target
  4003     languages.
  4004   - Code_Char represents HOL characters by character literals in target
  4005     languages.
  4006   - Code_Char_chr like Code_Char, but also offers treatment of character
  4007     codes; includes Code_Integer.
  4008   - Executable_Set allows to generate code for finite sets using lists.
  4009   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4010     denominator).
  4011   - Executable_Real implements a subset of real numbers, namly those
  4012     representable by rational numbers.
  4013   - Efficient_Nat implements natural numbers by integers, which in general will
  4014     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4015     includes Code_Integer.
  4016   - Code_Index provides an additional datatype index which is mapped to
  4017     target-language built-in integers.
  4018   - Code_Message provides an additional datatype message_string which is isomorphic to
  4019     strings; messages are mapped to target-language strings.
  4020 
  4021 * New package for inductive predicates
  4022 
  4023   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4024 
  4025     inductive
  4026       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4027       for z_1 :: U_1 and ... and z_n :: U_m
  4028     where
  4029       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4030     | ...
  4031 
  4032   with full support for type-inference, rather than
  4033 
  4034     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4035 
  4036     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4037     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4038 
  4039     inductive "s z_1 ... z_m"
  4040     intros
  4041       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4042       ...
  4043 
  4044   For backward compatibility, there is a wrapper allowing inductive
  4045   sets to be defined with the new package via
  4046 
  4047     inductive_set
  4048       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4049       for z_1 :: U_1 and ... and z_n :: U_m
  4050     where
  4051       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4052     | ...
  4053 
  4054   or
  4055 
  4056     inductive_set
  4057       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4058       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4059       for z_1 :: U_1 and ... and z_n :: U_m
  4060     where
  4061       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4062     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4063     | ...
  4064 
  4065   if the additional syntax "p ..." is required.
  4066 
  4067   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4068   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4069 
  4070   INCOMPATIBILITIES:
  4071 
  4072   - Since declaration and definition of inductive sets or predicates
  4073     is no longer separated, abbreviations involving the newly
  4074     introduced sets or predicates must be specified together with the
  4075     introduction rules after the 'where' keyword (see above), rather
  4076     than before the actual inductive definition.
  4077 
  4078   - The variables in induction and elimination rules are now
  4079     quantified in the order of their occurrence in the introduction
  4080     rules, rather than in alphabetical order. Since this may break
  4081     some proofs, these proofs either have to be repaired, e.g. by
  4082     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4083     statements of the form
  4084 
  4085       case (rule_i a_i_1 ... a_i_{k_i})
  4086 
  4087     or the old order of quantification has to be restored by explicitly adding
  4088     meta-level quantifiers in the introduction rules, i.e.
  4089 
  4090       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4091 
  4092   - The format of the elimination rules is now
  4093 
  4094       p z_1 ... z_m x_1 ... x_n ==>
  4095         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4096         ==> ... ==> P
  4097 
  4098     for predicates and
  4099 
  4100       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4101         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4102         ==> ... ==> P
  4103 
  4104     for sets rather than
  4105 
  4106       x : s z_1 ... z_m ==>
  4107         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4108         ==> ... ==> P
  4109 
  4110     This may require terms in goals to be expanded to n-tuples
  4111     (e.g. using case_tac or simplification with the split_paired_all
  4112     rule) before the above elimination rule is applicable.
  4113 
  4114   - The elimination or case analysis rules for (mutually) inductive
  4115     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4116     list of rules "p_1_..._p_k.elims" is no longer available.
  4117 
  4118 * New package "function"/"fun" for general recursive functions,
  4119 supporting mutual and nested recursion, definitions in local contexts,
  4120 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4121 for small examples, and the separate tutorial on the function
  4122 package. The old recdef "package" is still available as before, but
  4123 users are encouraged to use the new package.
  4124 
  4125 * Method "lexicographic_order" automatically synthesizes termination
  4126 relations as lexicographic combinations of size measures. 
  4127 
  4128 * Case-expressions allow arbitrary constructor-patterns (including
  4129 "_") and take their order into account, like in functional
  4130 programming.  Internally, this is translated into nested
  4131 case-expressions; missing cases are added and mapped to the predefined
  4132 constant "undefined". In complicated cases printing may no longer show
  4133 the original input but the internal form. Lambda-abstractions allow
  4134 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4135 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4136 variable.
  4137 
  4138 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4139 is an abbreviation for "of_nat :: nat => int". The simplification
  4140 rules for "of_nat" have been changed to work like "int" did
  4141 previously.  Potential INCOMPATIBILITY:
  4142   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4143   - of_nat_diff and of_nat_mult are no longer default simp rules
  4144 
  4145 * Method "algebra" solves polynomial equations over (semi)rings using
  4146 Groebner bases. The (semi)ring structure is defined by locales and the
  4147 tool setup depends on that generic context. Installing the method for
  4148 a specific type involves instantiating the locale and possibly adding
  4149 declarations for computation on the coefficients.  The method is
  4150 already instantiated for natural numbers and for the axiomatic class
  4151 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4152 CALCULEMUS 2007 for the general principles underlying this
  4153 architecture of context-aware proof-tools.
  4154 
  4155 * Method "ferrack" implements quantifier elimination over
  4156 special-purpose dense linear orders using locales (analogous to
  4157 "algebra"). The method is already installed for class
  4158 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4159 rat, etc.
  4160 
  4161 * Former constant "List.op @" now named "List.append".  Use ML
  4162 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4163 circumvent possible incompatibilities when working on ML level.
  4164 
  4165 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4166 
  4167 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4168 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4169 
  4170 * New syntax for Haskell-like list comprehension (input only), eg.
  4171 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4172 
  4173 * The special syntax for function "filter" has changed from [x :
  4174 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4175 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4176 
  4177 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4178 defined on nat only, as an abbreviation for [a..<Suc b]
  4179 INCOMPATIBILITY.
  4180 
  4181 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4182 
  4183 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4184 
  4185 * New lemma collection field_simps (an extension of ring_simps) for
  4186 manipulating (in)equations involving division. Multiplies with all
  4187 denominators that can be proved to be non-zero (in equations) or
  4188 positive/negative (in inequations).
  4189 
  4190 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4191 have been improved and renamed to ring_simps, group_simps and
  4192 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4193 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4194 
  4195 * Theory Library/Commutative_Ring: switched from recdef to function
  4196 package; constants add, mul, pow now curried.  Infix syntax for
  4197 algebraic operations.
  4198 
  4199 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4200 INCOMPATIBILITY.
  4201 
  4202 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4203 INCOMPATIBILITY.
  4204 
  4205 * HOL/records: generalised field-update to take a function on the
  4206 field rather than the new value: r(|A := x|) is translated to A_update
  4207 (K x) r The K-combinator that is internally used is called K_record.
  4208 INCOMPATIBILITY: Usage of the plain update functions has to be
  4209 adapted.
  4210  
  4211 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4212 * x = 0, which are required for a semiring.  Richer structures do not
  4213 inherit from semiring_0 anymore, because this property is a theorem
  4214 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4215 there is more to prove, but this is mostly trivial.
  4216 
  4217 * Class "recpower" is generalized to arbitrary monoids, not just
  4218 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4219 commutativity or semiring properties additionally.
  4220 
  4221 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4222 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4223 better use 'abbreviation'.
  4224 
  4225 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4226 
  4227 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4228 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4229 significant changes for setting up numeral syntax for types:
  4230   - New constants Numeral.pred and Numeral.succ instead
  4231       of former Numeral.bin_pred and Numeral.bin_succ.
  4232   - Use integer operations instead of bin_add, bin_mult and so on.
  4233   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4234   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4235 
  4236 See src/HOL/Integ/IntArith.thy for an example setup.
  4237 
  4238 * Command 'normal_form' computes the normal form of a term that may
  4239 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4240 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4241 heavy-duty computations because the functions are compiled to ML
  4242 first.  Correspondingly, a method "normalization" is provided.  See
  4243 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4244 
  4245 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4246 25 like -->); output depends on the "iff" print_mode, the default is
  4247 "A = B" (with priority 50).
  4248 
  4249 * Relations less (<) and less_eq (<=) are also available on type bool.
  4250 Modified syntax to disallow nesting without explicit parentheses,
  4251 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4252 INCOMPATIBILITY.
  4253 
  4254 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4255 
  4256 * Relation composition operator "op O" now has precedence 75 and binds
  4257 stronger than union and intersection. INCOMPATIBILITY.
  4258 
  4259 * The old set interval syntax "{m..n(}" (and relatives) has been
  4260 removed.  Use "{m..<n}" (and relatives) instead.
  4261 
  4262 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4263 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4264 ``declare [[simproc del: neq]]''.
  4265 
  4266 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4267 True/False.
  4268 
  4269 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4270 
  4271 * Theorem setsum_mult renamed to setsum_right_distrib.
  4272 
  4273 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4274 ``rule'' method.
  4275 
  4276 * Reimplemented methods "sat" and "satx", with several improvements:
  4277 goals no longer need to be stated as "<prems> ==> False", equivalences
  4278 (i.e. "=" on type bool) are handled, variable names of the form
  4279 "lit_<n>" are no longer reserved, significant speedup.
  4280 
  4281 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4282 zChaff is still supported as well.
  4283 
  4284 * 'inductive' and 'datatype': provide projections of mutual rules,
  4285 bundled as foo_bar.inducts;
  4286 
  4287 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4288 Library.
  4289 
  4290 * Library: moved theory Accessible_Part to main HOL.
  4291 
  4292 * Library: added theory Coinductive_List of potentially infinite lists
  4293 as greatest fixed-point.
  4294 
  4295 * Library: added theory AssocList which implements (finite) maps as
  4296 association lists.
  4297 
  4298 * Method "evaluation" solves goals (i.e. a boolean expression)
  4299 efficiently by compiling it to ML.  The goal is "proved" (via an
  4300 oracle) if it evaluates to True.
  4301 
  4302 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4303 also when invoked by the simplifier.  This results in the Simplifier
  4304 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4305 Configuration option fast_arith_split_limit=0 recovers the old
  4306 behavior.
  4307 
  4308 * Support for hex (0x20) and binary (0b1001) numerals.
  4309 
  4310 * New method: reify eqs (t), where eqs are equations for an
  4311 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4312 parameter, computes a term s::'b and a list xs::'a list and proves the
  4313 theorem I xs s = t. This is also known as reification or quoting. The
  4314 resulting theorem is applied to the subgoal to substitute t with I xs
  4315 s.  If t is omitted, the subgoal itself is reified.
  4316 
  4317 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4318 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4319 where f is supposed to be a computable function (in the sense of code
  4320 generattion). The method uses reify to compute s and xs as above then
  4321 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4322 r and finally gets the theorem t = r, which is again applied to the
  4323 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4324 
  4325 * Reflection: Automatic reification now handels binding, an example is
  4326 available in src/HOL/ex/ReflectionEx.thy
  4327 
  4328 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4329 command 'statespace' that is similar to 'record', but introduces an
  4330 abstract specification based on the locale infrastructure instead of
  4331 HOL types.  This leads to extra flexibility in composing state spaces,
  4332 in particular multiple inheritance and renaming of components.
  4333 
  4334 
  4335 *** HOL-Complex ***
  4336 
  4337 * Hyperreal: Functions root and sqrt are now defined on negative real
  4338 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4339 Nonnegativity side conditions have been removed from many lemmas, so
  4340 that more subgoals may now be solved by simplification; potential
  4341 INCOMPATIBILITY.
  4342 
  4343 * Real: new type classes formalize real normed vector spaces and
  4344 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4345 and norm :: 'a => real.
  4346 
  4347 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4348 reals into other types. The overloaded constant Reals :: 'a set is now
  4349 defined as range of_real; potential INCOMPATIBILITY.
  4350 
  4351 * Real: proper support for ML code generation, including 'quickcheck'.
  4352 Reals are implemented as arbitrary precision rationals.
  4353 
  4354 * Hyperreal: Several constants that previously worked only for the
  4355 reals have been generalized, so they now work over arbitrary vector
  4356 spaces. Type annotations may need to be added in some cases; potential
  4357 INCOMPATIBILITY.
  4358 
  4359   Infinitesimal  :: ('a::real_normed_vector) star set
  4360   HFinite        :: ('a::real_normed_vector) star set
  4361   HInfinite      :: ('a::real_normed_vector) star set
  4362   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4363   monad          :: ('a::real_normed_vector) star => 'a star set
  4364   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4365   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4366   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4367   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4368   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4369   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4370   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4371   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4372   sgn            :: 'a::real_normed_vector => 'a
  4373   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4374 
  4375 * Complex: Some complex-specific constants are now abbreviations for
  4376 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4377 hnorm.  Other constants have been entirely removed in favor of the
  4378 polymorphic versions (INCOMPATIBILITY):
  4379 
  4380   approx        <-- capprox
  4381   HFinite       <-- CFinite
  4382   HInfinite     <-- CInfinite
  4383   Infinitesimal <-- CInfinitesimal
  4384   monad         <-- cmonad
  4385   galaxy        <-- cgalaxy
  4386   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4387   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4388   (ns)deriv     <-- (ns)cderiv
  4389 
  4390 
  4391 *** HOL-Algebra ***
  4392 
  4393 * Formalisation of ideals and the quotient construction over rings.
  4394 
  4395 * Order and lattice theory no longer based on records.
  4396 INCOMPATIBILITY.
  4397 
  4398 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4399 greatest_closed.  INCOMPATIBILITY.
  4400 
  4401 * Method algebra is now set up via an attribute.  For examples see
  4402 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4403 of algebraic structures.
  4404 
  4405 * Renamed theory CRing to Ring.
  4406 
  4407 
  4408 *** HOL-Nominal ***
  4409 
  4410 * Substantial, yet incomplete support for nominal datatypes (binding
  4411 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4412 src/HOL/Nominal/Examples.  Prospective users should consult
  4413 http://isabelle.in.tum.de/nominal/
  4414 
  4415 
  4416 *** ML ***
  4417 
  4418 * ML basics: just one true type int, which coincides with IntInf.int
  4419 (even on SML/NJ).
  4420 
  4421 * ML within Isar: antiquotations allow to embed statically-checked
  4422 formal entities in the source, referring to the context available at
  4423 compile-time.  For example:
  4424 
  4425 ML {* @{sort "{zero,one}"} *}
  4426 ML {* @{typ "'a => 'b"} *}
  4427 ML {* @{term "%x. x"} *}
  4428 ML {* @{prop "x == y"} *}
  4429 ML {* @{ctyp "'a => 'b"} *}
  4430 ML {* @{cterm "%x. x"} *}
  4431 ML {* @{cprop "x == y"} *}
  4432 ML {* @{thm asm_rl} *}
  4433 ML {* @{thms asm_rl} *}
  4434 ML {* @{type_name c} *}
  4435 ML {* @{type_syntax c} *}
  4436 ML {* @{const_name c} *}
  4437 ML {* @{const_syntax c} *}
  4438 ML {* @{context} *}
  4439 ML {* @{theory} *}
  4440 ML {* @{theory Pure} *}
  4441 ML {* @{theory_ref} *}
  4442 ML {* @{theory_ref Pure} *}
  4443 ML {* @{simpset} *}
  4444 ML {* @{claset} *}
  4445 ML {* @{clasimpset} *}
  4446 
  4447 The same works for sources being ``used'' within an Isar context.
  4448 
  4449 * ML in Isar: improved error reporting; extra verbosity with
  4450 ML_Context.trace enabled.
  4451 
  4452 * Pure/General/table.ML: the join operations now works via exceptions
  4453 DUP/SAME instead of type option. This is simpler in simple cases, and
  4454 admits slightly more efficient complex applications.
  4455 
  4456 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4457 use Context.generic instead of just theory.
  4458 
  4459 * Pure: datatype Context.generic joins theory/Proof.context and
  4460 provides some facilities for code that works in either kind of
  4461 context, notably GenericDataFun for uniform theory and proof data.
  4462 
  4463 * Pure: simplified internal attribute type, which is now always
  4464 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4465 local (Proof.context) attributes have been discontinued, while
  4466 minimizing code duplication. Thm.rule_attribute and
  4467 Thm.declaration_attribute build canonical attributes; see also structure
  4468 Context for further operations on Context.generic, notably
  4469 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4470 declarations and definitions.
  4471 
  4472 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4473 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4474 init only required for impure data. INCOMPATIBILITY: empty really need
  4475 to be empty (no dependencies on theory content!)
  4476 
  4477 * Pure/kernel: consts certification ignores sort constraints given in
  4478 signature declarations. (This information is not relevant to the
  4479 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4480 potential INCOMPATIBILITY.
  4481 
  4482 * Pure: axiomatic type classes are now purely definitional, with
  4483 explicit proofs of class axioms and super class relations performed
  4484 internally. See Pure/axclass.ML for the main internal interfaces --
  4485 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4486 AxClass.axiomatize_class/classrel/arity supersede
  4487 Sign.add_classes/classrel/arities.
  4488 
  4489 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4490 global/local versions on theory vs. Proof.context have been
  4491 discontinued; Attrib.syntax and Method.syntax have been adapted
  4492 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4493 attributes, methods, etc.
  4494 
  4495 * Pure: several functions of signature "... -> theory -> theory * ..."
  4496 have been reoriented to "... -> theory -> ... * theory" in order to
  4497 allow natural usage in combination with the ||>, ||>>, |-> and
  4498 fold_map combinators.
  4499 
  4500 * Pure: official theorem names (closed derivations) and additional
  4501 comments (tags) are now strictly separate.  Name hints -- which are
  4502 maintained as tags -- may be attached any time without affecting the
  4503 derivation.
  4504 
  4505 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4506 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4507 achieve the old behaviour.
  4508 
  4509 * Pure: the "Goal" constant is now called "prop", supporting a
  4510 slightly more general idea of ``protecting'' meta-level rule
  4511 statements.
  4512 
  4513 * Pure: Logic.(un)varify only works in a global context, which is now
  4514 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4515 Logic.legacy_(un)varify as temporary workaround.
  4516 
  4517 * Pure: structure Name provides scalable operations for generating
  4518 internal variable names, notably Name.variants etc.  This replaces
  4519 some popular functions from term.ML:
  4520 
  4521   Term.variant		->  Name.variant
  4522   Term.variantlist	->  Name.variant_list
  4523   Term.invent_names	->  Name.invent_list
  4524 
  4525 Note that low-level renaming rarely occurs in new code -- operations
  4526 from structure Variable are used instead (see below).
  4527 
  4528 * Pure: structure Variable provides fundamental operations for proper
  4529 treatment of fixed/schematic variables in a context.  For example,
  4530 Variable.import introduces fixes for schematics of given facts and
  4531 Variable.export reverses the effect (up to renaming) -- this replaces
  4532 various freeze_thaw operations.
  4533 
  4534 * Pure: structure Goal provides simple interfaces for
  4535 init/conclude/finish and tactical prove operations (replacing former
  4536 Tactic.prove).  Goal.prove is the canonical way to prove results
  4537 within a given context; Goal.prove_global is a degraded version for
  4538 theory level goals, including a global Drule.standard.  Note that
  4539 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4540 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4541 in a locale context).
  4542 
  4543 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4544 and type checking (Syntax.check_term etc.), with common combinations
  4545 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4546 which are considered legacy and await removal.
  4547 
  4548 * Pure/Syntax: generic interfaces for type unchecking
  4549 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4550 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4551 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4552 available for convenience, but refer to the very same operations using
  4553 a mere theory instead of a full context.
  4554 
  4555 * Isar: simplified treatment of user-level errors, using exception
  4556 ERROR of string uniformly.  Function error now merely raises ERROR,
  4557 without any side effect on output channels.  The Isar toplevel takes
  4558 care of proper display of ERROR exceptions.  ML code may use plain
  4559 handle/can/try; cat_error may be used to concatenate errors like this:
  4560 
  4561   ... handle ERROR msg => cat_error msg "..."
  4562 
  4563 Toplevel ML code (run directly or through the Isar toplevel) may be
  4564 embedded into the Isar toplevel with exception display/debug like
  4565 this:
  4566 
  4567   Isar.toplevel (fn () => ...)
  4568 
  4569 INCOMPATIBILITY, removed special transform_error facilities, removed
  4570 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4571 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4572 -- use plain ERROR instead.
  4573 
  4574 * Isar: theory setup now has type (theory -> theory), instead of a
  4575 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4576 
  4577 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4578 ProofContext.debug/verbose flags.
  4579 
  4580 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4581 theory before entering a proof state.  Transactions now always see a
  4582 quasi-functional intermediate checkpoint, both in interactive and
  4583 batch mode.
  4584 
  4585 * Isar: simplified interfaces for outer syntax.  Renamed
  4586 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4587 OuterSyntax.add_parsers -- this functionality is now included in
  4588 OuterSyntax.command etc.  INCOMPATIBILITY.
  4589 
  4590 * Simplifier: the simpset of a running simplification process now
  4591 contains a proof context (cf. Simplifier.the_context), which is the
  4592 very context that the initial simpset has been retrieved from (by
  4593 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4594 (solver, looper etc.) may depend on arbitrary proof data.
  4595 
  4596 * Simplifier.inherit_context inherits the proof context (plus the
  4597 local bounds) of the current simplification process; any simproc
  4598 etc. that calls the Simplifier recursively should do this!  Removed
  4599 former Simplifier.inherit_bounds, which is already included here --
  4600 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4601 specify an explicit context using Simplifier.context/theory_context.
  4602 
  4603 * Simplifier/Classical Reasoner: more abstract interfaces
  4604 change_simpset/claset for modifying the simpset/claset reference of a
  4605 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4606 INCOMPATIBILITY.
  4607 
  4608 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4609 "Trueprop" etc.
  4610 
  4611 
  4612 *** System ***
  4613 
  4614 * settings: the default heap location within ISABELLE_HOME_USER now
  4615 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4616 Isabelle installations.
  4617 
  4618 * isabelle-process: option -S (secure mode) disables some critical
  4619 operations, notably runtime compilation and evaluation of ML source
  4620 code.
  4621 
  4622 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4623 
  4624 * Support for parallel execution, using native multicore support of
  4625 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4626 independent theories, according to the given theory header
  4627 specifications. The maximum number of worker threads is specified via
  4628 usedir option -M or the "max-threads" setting in Proof General. A
  4629 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4630 to 6 on a 8-core machine.  User-code needs to observe certain
  4631 guidelines for thread-safe programming, see appendix A in the Isar
  4632 Implementation manual.
  4633 
  4634 
  4635 
  4636 New in Isabelle2005 (October 2005)
  4637 ----------------------------------
  4638 
  4639 *** General ***
  4640 
  4641 * Theory headers: the new header syntax for Isar theories is
  4642 
  4643   theory <name>
  4644   imports <theory1> ... <theoryN>
  4645   uses <file1> ... <fileM>
  4646   begin
  4647 
  4648 where the 'uses' part is optional.  The previous syntax
  4649 
  4650   theory <name> = <theory1> + ... + <theoryN>:
  4651 
  4652 will disappear in the next release.  Use isatool fixheaders to convert
  4653 existing theory files.  Note that there is no change in ancient
  4654 non-Isar theories now, but these will disappear soon.
  4655 
  4656 * Theory loader: parent theories can now also be referred to via
  4657 relative and absolute paths.
  4658 
  4659 * Command 'find_theorems' searches for a list of criteria instead of a
  4660 list of constants. Known criteria are: intro, elim, dest, name:string,
  4661 simp:term, and any term. Criteria can be preceded by '-' to select
  4662 theorems that do not match. Intro, elim, dest select theorems that
  4663 match the current goal, name:s selects theorems whose fully qualified
  4664 name contain s, and simp:term selects all simplification rules whose
  4665 lhs match term.  Any other term is interpreted as pattern and selects
  4666 all theorems matching the pattern. Available in ProofGeneral under
  4667 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4668 
  4669   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4670 
  4671 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4672 matching the current goal as introduction rule and not having "HOL."
  4673 in their name (i.e. not being defined in theory HOL).
  4674 
  4675 * Command 'thms_containing' has been discontinued in favour of
  4676 'find_theorems'; INCOMPATIBILITY.
  4677 
  4678 * Communication with Proof General is now 8bit clean, which means that
  4679 Unicode text in UTF-8 encoding may be used within theory texts (both
  4680 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4681 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4682 
  4683   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4684   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4685 
  4686 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4687 Classical Reasoner.  Typical big applications run around 2 times
  4688 faster.
  4689 
  4690 
  4691 *** Document preparation ***
  4692 
  4693 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4694 of raw sources.  Only those symbols that do not require additional
  4695 LaTeX packages (depending on comments in isabellesym.sty) are
  4696 displayed properly, everything else is left verbatim.  isatool display
  4697 and isatool print are used as front ends (these are subject to the
  4698 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4699 
  4700 * Command tags control specific markup of certain regions of text,
  4701 notably folding and hiding.  Predefined tags include "theory" (for
  4702 theory begin and end), "proof" for proof commands, and "ML" for
  4703 commands involving ML code; the additional tags "visible" and
  4704 "invisible" are unused by default.  Users may give explicit tag
  4705 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4706 interpretation of tags is determined by the LaTeX job during document
  4707 preparation: see option -V of isatool usedir, or options -n and -t of
  4708 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4709 \isadroptag.
  4710 
  4711 Several document versions may be produced at the same time via isatool
  4712 usedir (the generated index.html will link all of them).  Typical
  4713 specifications include ''-V document=theory,proof,ML'' to present
  4714 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4715 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4716 these parts without any formal replacement text.  The Isabelle site
  4717 default settings produce ''document'' and ''outline'' versions as
  4718 specified above.
  4719 
  4720 * Several new antiquotations:
  4721 
  4722   @{term_type term} prints a term with its type annotated;
  4723 
  4724   @{typeof term} prints the type of a term;
  4725 
  4726   @{const const} is the same as @{term const}, but checks that the
  4727   argument is a known logical constant;
  4728 
  4729   @{term_style style term} and @{thm_style style thm} print a term or
  4730   theorem applying a "style" to it
  4731 
  4732   @{ML text}
  4733 
  4734 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4735 definitions, equations, inequations etc., 'concl' printing only the
  4736 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4737 to print the specified premise.  TermStyle.add_style provides an ML
  4738 interface for introducing further styles.  See also the "LaTeX Sugar"
  4739 document practical applications.  The ML antiquotation prints
  4740 type-checked ML expressions verbatim.
  4741 
  4742 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4743 and 'text' support optional locale specification '(in loc)', which
  4744 specifies the default context for interpreting antiquotations.  For
  4745 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4746 
  4747 * Option 'locale=NAME' of antiquotations specifies an alternative
  4748 context interpreting the subsequent argument.  For example: @{thm
  4749 [locale=lattice] inf_assoc}.
  4750 
  4751 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4752 a proof context.
  4753 
  4754 * Proper output of antiquotations for theory commands involving a
  4755 proof context (such as 'locale' or 'theorem (in loc) ...').
  4756 
  4757 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4758 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4759 
  4760 * isatool usedir: new option -C (default true) controls whether option
  4761 -D should include a copy of the original document directory; -C false
  4762 prevents unwanted effects such as copying of administrative CVS data.
  4763 
  4764 
  4765 *** Pure ***
  4766 
  4767 * Considerably improved version of 'constdefs' command.  Now performs
  4768 automatic type-inference of declared constants; additional support for
  4769 local structure declarations (cf. locales and HOL records), see also
  4770 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4771 sequential dependencies of definitions within a single 'constdefs'
  4772 section; moreover, the declared name needs to be an identifier.  If
  4773 all fails, consider to fall back on 'consts' and 'defs' separately.
  4774 
  4775 * Improved indexed syntax and implicit structures.  First of all,
  4776 indexed syntax provides a notational device for subscripted
  4777 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4778 expressions.  Secondly, in a local context with structure
  4779 declarations, number indexes \<^sub>n or the empty index (default
  4780 number 1) refer to a certain fixed variable implicitly; option
  4781 show_structs controls printing of implicit structures.  Typical
  4782 applications of these concepts involve record types and locales.
  4783 
  4784 * New command 'no_syntax' removes grammar declarations (and
  4785 translations) resulting from the given syntax specification, which is
  4786 interpreted in the same manner as for the 'syntax' command.
  4787 
  4788 * 'Advanced' translation functions (parse_translation etc.) may depend
  4789 on the signature of the theory context being presently used for
  4790 parsing/printing, see also isar-ref manual.
  4791 
  4792 * Improved 'oracle' command provides a type-safe interface to turn an
  4793 ML expression of type theory -> T -> term into a primitive rule of
  4794 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4795 is already included here); see also FOL/ex/IffExample.thy;
  4796 INCOMPATIBILITY.
  4797 
  4798 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4799 before); "cI" is no longer bound, use "c.intro" instead.
  4800 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4801 axclasses vs. locales.
  4802 
  4803 * Improved internal renaming of symbolic identifiers -- attach primes
  4804 instead of base 26 numbers.
  4805 
  4806 * New flag show_question_marks controls printing of leading question
  4807 marks in schematic variable names.
  4808 
  4809 * In schematic variable names, *any* symbol following \<^isub> or
  4810 \<^isup> is now treated as part of the base name.  For example, the
  4811 following works without printing of awkward ".0" indexes:
  4812 
  4813   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4814     by simp
  4815 
  4816 * Inner syntax includes (*(*nested*) comments*).
  4817 
  4818 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4819 annotations as "(00...)".
  4820 
  4821 * Clear separation of logical types and nonterminals, where the latter
  4822 may only occur in 'syntax' specifications or type abbreviations.
  4823 Before that distinction was only partially implemented via type class
  4824 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4825 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4826 exotic syntax specifications may require further adaption
  4827 (e.g. Cube/Cube.thy).
  4828 
  4829 * Removed obsolete type class "logic", use the top sort {} instead.
  4830 Note that non-logical types should be declared as 'nonterminals'
  4831 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4832 specifications.
  4833 
  4834 * Attributes 'induct' and 'cases': type or set names may now be
  4835 locally fixed variables as well.
  4836 
  4837 * Simplifier: can now control the depth to which conditional rewriting
  4838 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4839 Limit.
  4840 
  4841 * Simplifier: simplification procedures may now take the current
  4842 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4843 interface), which is very useful for calling the Simplifier
  4844 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4845 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4846 low-level mk_simproc no longer applies Logic.varify internally, to
  4847 allow for use in a context of fixed variables.
  4848 
  4849 * thin_tac now works even if the assumption being deleted contains !!
  4850 or ==>.  More generally, erule now works even if the major premise of
  4851 the elimination rule contains !! or ==>.
  4852 
  4853 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4854 
  4855 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4856 from Pure, which contains all common declarations already.  Both
  4857 theories are defined via plain Isabelle/Isar .thy files.
  4858 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4859 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4860 use isatool fixcpure to adapt your theory and ML sources.
  4861 
  4862 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4863 selections of theorems in named facts via index ranges.
  4864 
  4865 * 'print_theorems': in theory mode, really print the difference
  4866 wrt. the last state (works for interactive theory development only),
  4867 in proof mode print all local facts (cf. 'print_facts');
  4868 
  4869 * 'hide': option '(open)' hides only base names.
  4870 
  4871 * More efficient treatment of intermediate checkpoints in interactive
  4872 theory development.
  4873 
  4874 * Code generator is now invoked via code_module (incremental code
  4875 generation) and code_library (modular code generation, ML structures
  4876 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4877 must be quoted when used as identifiers.
  4878 
  4879 * New 'value' command for reading, evaluating and printing terms using
  4880 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4881 quoted when used as identifier.
  4882 
  4883 
  4884 *** Locales ***
  4885 
  4886 * New commands for the interpretation of locale expressions in
  4887 theories (1), locales (2) and proof contexts (3).  These generate
  4888 proof obligations from the expression specification.  After the
  4889 obligations have been discharged, theorems of the expression are added
  4890 to the theory, target locale or proof context.  The synopsis of the
  4891 commands is a follows:
  4892 
  4893   (1) interpretation expr inst
  4894   (2) interpretation target < expr
  4895   (3) interpret expr inst
  4896 
  4897 Interpretation in theories and proof contexts require a parameter
  4898 instantiation of terms from the current context.  This is applied to
  4899 specifications and theorems of the interpreted expression.
  4900 Interpretation in locales only permits parameter renaming through the
  4901 locale expression.  Interpretation is smart in that interpretations
  4902 that are active already do not occur in proof obligations, neither are
  4903 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4904 inspect active interpretations of a particular locale.  For details,
  4905 see the Isar Reference manual.  Examples can be found in
  4906 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4907 
  4908 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4909 'interpret' instead.
  4910 
  4911 * New context element 'constrains' for adding type constraints to
  4912 parameters.
  4913 
  4914 * Context expressions: renaming of parameters with syntax
  4915 redeclaration.
  4916 
  4917 * Locale declaration: 'includes' disallowed.
  4918 
  4919 * Proper static binding of attribute syntax -- i.e. types / terms /
  4920 facts mentioned as arguments are always those of the locale definition
  4921 context, independently of the context of later invocations.  Moreover,
  4922 locale operations (renaming and type / term instantiation) are applied
  4923 to attribute arguments as expected.
  4924 
  4925 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4926 actual attributes; rare situations may require Attrib.attribute to
  4927 embed those attributes into Attrib.src that lack concrete syntax.
  4928 Attribute implementations need to cooperate properly with the static
  4929 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4930 Attrib.XXX_thm etc. already do the right thing without further
  4931 intervention.  Only unusual applications -- such as "where" or "of"
  4932 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4933 on the context and the facts involved -- may have to assign parsed
  4934 values to argument tokens explicitly.
  4935 
  4936 * Changed parameter management in theorem generation for long goal
  4937 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4938 theorem statement in rare situations.
  4939 
  4940 * Locale inspection command 'print_locale' omits notes elements.  Use
  4941 'print_locale!' to have them included in the output.
  4942 
  4943 
  4944 *** Provers ***
  4945 
  4946 * Provers/hypsubst.ML: improved version of the subst method, for
  4947 single-step rewriting: it now works in bound variable contexts. New is
  4948 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4949 rewrite a different subterm than the original subst method, which is
  4950 still available as 'simplesubst'.
  4951 
  4952 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4953 and quasi orders.
  4954 
  4955 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4956 reflexive-transitive closure of relations.
  4957 
  4958 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4959 limit (previously hard-coded with a value of 20) user-definable.
  4960 
  4961 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4962 is peformed already.  Object-logics merely need to finish their
  4963 initial simpset configuration as before.  INCOMPATIBILITY.
  4964 
  4965 
  4966 *** HOL ***
  4967 
  4968 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4969 
  4970   syntax (epsilon)
  4971     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4972 
  4973 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4974 and x-symbol; use option '-m epsilon' to get it actually printed.
  4975 Moreover, the mathematically important symbolic identifier \<epsilon>
  4976 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4977 
  4978 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4979 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4980 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4981 support corresponding Isar calculations.
  4982 
  4983 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4984 instead of ":".
  4985 
  4986 * theory SetInterval: changed the syntax for open intervals:
  4987 
  4988   Old       New
  4989   {..n(}    {..<n}
  4990   {)n..}    {n<..}
  4991   {m..n(}   {m..<n}
  4992   {)m..n}   {m<..n}
  4993   {)m..n(}  {m<..<n}
  4994 
  4995 The old syntax is still supported but will disappear in the next
  4996 release.  For conversion use the following Emacs search and replace
  4997 patterns (these are not perfect but work quite well):
  4998 
  4999   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5000   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5001 
  5002 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5003 equalities in commutative rings; method 'algebra' provides a generic
  5004 interface.
  5005 
  5006 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5007 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5008 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5009 be a tuple pattern.
  5010 
  5011 Some new syntax forms are available:
  5012 
  5013   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5014   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5015   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5016   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5017 
  5018 The latter form "\<Sum>x < k. e" used to be based on a separate
  5019 function "Summation", which has been discontinued.
  5020 
  5021 * theory Finite_Set: in structured induction proofs, the insert case
  5022 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5023 (insert F x)'.
  5024 
  5025 * The 'refute' command has been extended to support a much larger
  5026 fragment of HOL, including axiomatic type classes, constdefs and
  5027 typedefs, inductive datatypes and recursion.
  5028 
  5029 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5030 Requires zChaff with proof generation to be installed.  See
  5031 HOL/ex/SAT_Examples.thy for examples.
  5032 
  5033 * Datatype induction via method 'induct' now preserves the name of the
  5034 induction variable. For example, when proving P(xs::'a list) by
  5035 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5036 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5037 in unstructured proof scripts.
  5038 
  5039 * Reworked implementation of records.  Improved scalability for
  5040 records with many fields, avoiding performance problems for type
  5041 inference. Records are no longer composed of nested field types, but
  5042 of nested extension types. Therefore the record type only grows linear
  5043 in the number of extensions and not in the number of fields.  The
  5044 top-level (users) view on records is preserved.  Potential
  5045 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5046 old record representation. The type generated for a record is called
  5047 <record_name>_ext_type.
  5048 
  5049 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5050 proofs triggered by a record definition or a simproc (if
  5051 quick_and_dirty is enabled).  Definitions of large records can take
  5052 quite long.
  5053 
  5054 New simproc record_upd_simproc for simplification of multiple record
  5055 updates enabled by default.  Moreover, trivial updates are also
  5056 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5057 occasionally, since simplification is more powerful by default.
  5058 
  5059 * typedef: proper support for polymorphic sets, which contain extra
  5060 type-variables in the term.
  5061 
  5062 * Simplifier: automatically reasons about transitivity chains
  5063 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5064 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5065 old proofs break occasionally as simplification may now solve more
  5066 goals than previously.
  5067 
  5068 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5069 present.  Works for all partial orders (class "order"), in particular
  5070 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5071 just like y <= x.
  5072 
  5073 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5074 bound variable or a constant then the let is unfolded.  Otherwise
  5075 first a is simplified to b, and then f b is simplified to g. If
  5076 possible we abstract b from g arriving at "let x = b in h x",
  5077 otherwise we unfold the let and arrive at g.  The simproc can be
  5078 enabled/disabled by the reference use_let_simproc.  Potential
  5079 INCOMPATIBILITY since simplification is more powerful by default.
  5080 
  5081 * Classical reasoning: the meson method now accepts theorems as arguments.
  5082 
  5083 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5084 jobs to provide advice on the provability of subgoals.
  5085 
  5086 * Theory OrderedGroup and Ring_and_Field: various additions and
  5087 improvements to faciliate calculations involving equalities and
  5088 inequalities.
  5089 
  5090 The following theorems have been eliminated or modified
  5091 (INCOMPATIBILITY):
  5092 
  5093   abs_eq             now named abs_of_nonneg
  5094   abs_of_ge_0        now named abs_of_nonneg
  5095   abs_minus_eq       now named abs_of_nonpos
  5096   imp_abs_id         now named abs_of_nonneg
  5097   imp_abs_neg_id     now named abs_of_nonpos
  5098   mult_pos           now named mult_pos_pos
  5099   mult_pos_le        now named mult_nonneg_nonneg
  5100   mult_pos_neg_le    now named mult_nonneg_nonpos
  5101   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5102   mult_neg           now named mult_neg_neg
  5103   mult_neg_le        now named mult_nonpos_nonpos
  5104 
  5105 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5106      
  5107      zero_le_square
  5108      not_square_less_zero 
  5109 
  5110   The following lemmas have been deleted from Real/RealPow:
  5111   
  5112      realpow_zero_zero
  5113      realpow_two
  5114      realpow_less
  5115      zero_le_power
  5116      realpow_two_le
  5117      abs_realpow_two
  5118      realpow_two_abs     
  5119 
  5120 * Theory Parity: added rules for simplifying exponents.
  5121 
  5122 * Theory List:
  5123 
  5124 The following theorems have been eliminated or modified
  5125 (INCOMPATIBILITY):
  5126 
  5127   list_all_Nil       now named list_all.simps(1)
  5128   list_all_Cons      now named list_all.simps(2)
  5129   list_all_conv      now named list_all_iff
  5130   set_mem_eq         now named mem_iff
  5131 
  5132 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5133 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5134 
  5135 
  5136 *** HOL-Complex ***
  5137 
  5138 * Theory RealDef: better support for embedding natural numbers and
  5139 integers in the reals.
  5140 
  5141 The following theorems have been eliminated or modified
  5142 (INCOMPATIBILITY):
  5143 
  5144   exp_ge_add_one_self  now requires no hypotheses
  5145   real_of_int_add      reversed direction of equality (use [symmetric])
  5146   real_of_int_minus    reversed direction of equality (use [symmetric])
  5147   real_of_int_diff     reversed direction of equality (use [symmetric])
  5148   real_of_int_mult     reversed direction of equality (use [symmetric])
  5149 
  5150 * Theory RComplete: expanded support for floor and ceiling functions.
  5151 
  5152 * Theory Ln is new, with properties of the natural logarithm
  5153 
  5154 * Hyperreal: There is a new type constructor "star" for making
  5155 nonstandard types.  The old type names are now type synonyms:
  5156 
  5157   hypreal = real star
  5158   hypnat = nat star
  5159   hcomplex = complex star
  5160 
  5161 * Hyperreal: Many groups of similarly-defined constants have been
  5162 replaced by polymorphic versions (INCOMPATIBILITY):
  5163 
  5164   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5165 
  5166   starset      <-- starsetNat, starsetC
  5167   *s*          <-- *sNat*, *sc*
  5168   starset_n    <-- starsetNat_n, starsetC_n
  5169   *sn*         <-- *sNatn*, *scn*
  5170   InternalSets <-- InternalNatSets, InternalCSets
  5171 
  5172   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5173   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5174   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5175   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5176   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5177 
  5178 * Hyperreal: Many type-specific theorems have been removed in favor of
  5179 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5180 
  5181   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5182   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5183   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5184   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5185   right_minus <-- hypreal_add_minus
  5186   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5187   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5188   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5189   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5190   mult_1_right <-- hcomplex_mult_one_right
  5191   mult_zero_left <-- hcomplex_mult_zero_left
  5192   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5193   right_distrib <-- hypnat_add_mult_distrib2
  5194   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5195   right_inverse <-- hypreal_mult_inverse
  5196   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5197   order_refl <-- {hypreal,hypnat}_le_refl
  5198   order_trans <-- {hypreal,hypnat}_le_trans
  5199   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5200   order_less_le <-- {hypreal,hypnat}_less_le
  5201   linorder_linear <-- {hypreal,hypnat}_le_linear
  5202   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5203   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5204   add_nonneg_nonneg <-- hypreal_le_add_order
  5205 
  5206 * Hyperreal: Separate theorems having to do with type-specific
  5207 versions of constants have been merged into theorems that apply to the
  5208 new polymorphic constants (INCOMPATIBILITY):
  5209 
  5210   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5211   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5212   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5213   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5214   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5215   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5216   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5217   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5218   STAR_diff <-- {STAR,STARC}_diff
  5219   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5220     STARC_hcomplex_of_complex}_image_subset
  5221   starset_n_Un <-- starset{Nat,C}_n_Un
  5222   starset_n_Int <-- starset{Nat,C}_n_Int
  5223   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5224   starset_n_diff <-- starset{Nat,C}_n_diff
  5225   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5226   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5227   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5228   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5229   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5230   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5231   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5232   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5233   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5234   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5235   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5236   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5237   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5238   starfun_diff <-- starfun{C,RC,CR}_diff
  5239   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5240   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5241   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5242   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5243   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5244   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5245   starfun_Id <-- starfunC_Id
  5246   starfun_approx <-- starfun{Nat,CR}_approx
  5247   starfun_capprox <-- starfun{C,RC}_capprox
  5248   starfun_abs <-- starfunNat_rabs
  5249   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5250   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5251   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5252   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5253   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5254   starfun_add_approx <-- starfunCR_add_approx
  5255   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5256   starfun_divide <-- starfun{C,CR,RC}_divide
  5257   starfun_n <-- starfun{Nat,C}_n
  5258   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5259   starfun_n_add <-- starfun{Nat,C}_n_add
  5260   starfun_n_add_minus <-- starfunNat_n_add_minus
  5261   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5262   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5263   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5264 
  5265   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5266   star_n_minus <-- {hypreal,hcomplex}_minus
  5267   star_n_diff <-- {hypreal,hcomplex}_diff
  5268   star_n_mult <-- {hypreal,hcomplex}_mult
  5269   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5270   star_n_le <-- {hypreal,hypnat}_le
  5271   star_n_less <-- {hypreal,hypnat}_less
  5272   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5273   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5274   star_n_abs <-- hypreal_hrabs
  5275   star_n_divide <-- hcomplex_divide
  5276 
  5277   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5278   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5279   star_of_diff <-- hypreal_of_real_diff
  5280   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5281   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5282   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5283   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5284   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5285   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5286   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5287   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5288   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5289   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5290   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5291   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5292   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5293   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5294   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5295   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5296   star_of_power <-- hypreal_of_real_power
  5297   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5298 
  5299 * Hyperreal: new method "transfer" that implements the transfer
  5300 principle of nonstandard analysis. With a subgoal that mentions
  5301 nonstandard types like "'a star", the command "apply transfer"
  5302 replaces it with an equivalent one that mentions only standard types.
  5303 To be successful, all free variables must have standard types; non-
  5304 standard variables must have explicit universal quantifiers.
  5305 
  5306 * Hyperreal: A theory of Taylor series.
  5307 
  5308 
  5309 *** HOLCF ***
  5310 
  5311 * Discontinued special version of 'constdefs' (which used to support
  5312 continuous functions) in favor of the general Pure one with full
  5313 type-inference.
  5314 
  5315 * New simplification procedure for solving continuity conditions; it
  5316 is much faster on terms with many nested lambda abstractions (cubic
  5317 instead of exponential time).
  5318 
  5319 * New syntax for domain package: selector names are now optional.
  5320 Parentheses should be omitted unless argument is lazy, for example:
  5321 
  5322   domain 'a stream = cons "'a" (lazy "'a stream")
  5323 
  5324 * New command 'fixrec' for defining recursive functions with pattern
  5325 matching; defining multiple functions with mutual recursion is also
  5326 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5327 sinr, or any data constructor defined by the domain package. The given
  5328 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5329 syntax and examples.
  5330 
  5331 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5332 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5333 but the proof obligation additionally includes an admissibility
  5334 requirement. The packages generate instances of class cpo or pcpo,
  5335 with continuity and strictness theorems for Rep and Abs.
  5336 
  5337 * HOLCF: Many theorems have been renamed according to a more standard naming
  5338 scheme (INCOMPATIBILITY):
  5339 
  5340   foo_inject:  "foo$x = foo$y ==> x = y"
  5341   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5342   foo_less:    "(foo$x << foo$y) = (x << y)"
  5343   foo_strict:  "foo$UU = UU"
  5344   foo_defined: "... ==> foo$x ~= UU"
  5345   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5346 
  5347 
  5348 *** ZF ***
  5349 
  5350 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5351 including the First Isomorphism Theorem (on quotienting by the kernel
  5352 of a homomorphism).
  5353 
  5354 * ZF/Simplifier: install second copy of type solver that actually
  5355 makes use of TC rules declared to Isar proof contexts (or locales);
  5356 the old version is still required for ML proof scripts.
  5357 
  5358 
  5359 *** Cube ***
  5360 
  5361 * Converted to Isar theory format; use locales instead of axiomatic
  5362 theories.
  5363 
  5364 
  5365 *** ML ***
  5366 
  5367 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5368 for ||>, ||>>, |>>,
  5369 
  5370 * Pure/library.ML no longer defines its own option datatype, but uses
  5371 that of the SML basis, which has constructors NONE and SOME instead of
  5372 None and Some, as well as exception Option.Option instead of OPTION.
  5373 The functions the, if_none, is_some, is_none have been adapted
  5374 accordingly, while Option.map replaces apsome.
  5375 
  5376 * Pure/library.ML: the exception LIST has been given up in favour of
  5377 the standard exceptions Empty and Subscript, as well as
  5378 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5379 superceded by the standard hd and tl functions etc.
  5380 
  5381 A number of basic list functions are no longer exported to the ML
  5382 toplevel, as they are variants of predefined functions.  The following
  5383 suggests how one can translate existing code:
  5384 
  5385     rev_append xs ys = List.revAppend (xs, ys)
  5386     nth_elem (i, xs) = List.nth (xs, i)
  5387     last_elem xs = List.last xs
  5388     flat xss = List.concat xss
  5389     seq fs = List.app fs
  5390     partition P xs = List.partition P xs
  5391     mapfilter f xs = List.mapPartial f xs
  5392 
  5393 * Pure/library.ML: several combinators for linear functional
  5394 transformations, notably reverse application and composition:
  5395 
  5396   x |> f                f #> g
  5397   (x, y) |-> f          f #-> g
  5398 
  5399 * Pure/library.ML: introduced/changed precedence of infix operators:
  5400 
  5401   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5402   infix 2 ?;
  5403   infix 3 o oo ooo oooo;
  5404   infix 4 ~~ upto downto;
  5405 
  5406 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5407 infix operators.
  5408 
  5409 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5410 fold_map support linear functional transformations and nesting.  For
  5411 example:
  5412 
  5413   fold f [x1, ..., xN] y =
  5414     y |> f x1 |> ... |> f xN
  5415 
  5416   (fold o fold) f [xs1, ..., xsN] y =
  5417     y |> fold f xs1 |> ... |> fold f xsN
  5418 
  5419   fold f [x1, ..., xN] =
  5420     f x1 #> ... #> f xN
  5421 
  5422   (fold o fold) f [xs1, ..., xsN] =
  5423     fold f xs1 #> ... #> fold f xsN
  5424 
  5425 * Pure/library.ML: the following selectors on type 'a option are
  5426 available:
  5427 
  5428   the:               'a option -> 'a  (*partial*)
  5429   these:             'a option -> 'a  where 'a = 'b list
  5430   the_default: 'a -> 'a option -> 'a
  5431   the_list:          'a option -> 'a list
  5432 
  5433 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5434 basic operations for association lists, following natural argument
  5435 order; moreover the explicit equality predicate passed here avoids
  5436 potentially expensive polymorphic runtime equality checks.
  5437 The old functions may be expressed as follows:
  5438 
  5439   assoc = uncurry (AList.lookup (op =))
  5440   assocs = these oo AList.lookup (op =)
  5441   overwrite = uncurry (AList.update (op =)) o swap
  5442 
  5443 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5444 
  5445   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5446   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5447 
  5448 replacing make_keylist and keyfilter (occassionally used)
  5449 Naive rewrites:
  5450 
  5451   make_keylist = AList.make
  5452   keyfilter = AList.find (op =)
  5453 
  5454 * eq_fst and eq_snd now take explicit equality parameter, thus
  5455   avoiding eqtypes. Naive rewrites:
  5456 
  5457     eq_fst = eq_fst (op =)
  5458     eq_snd = eq_snd (op =)
  5459 
  5460 * Removed deprecated apl and apr (rarely used).
  5461   Naive rewrites:
  5462 
  5463     apl (n, op) =>>= curry op n
  5464     apr (op, m) =>>= fn n => op (n, m)
  5465 
  5466 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5467 provides a reasonably efficient light-weight implementation of sets as
  5468 lists.
  5469 
  5470 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5471 few new operations; existing lookup and update are now curried to
  5472 follow natural argument order (for use with fold etc.);
  5473 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5474 
  5475 * Pure/General: output via the Isabelle channels of
  5476 writeln/warning/error etc. is now passed through Output.output, with a
  5477 hook for arbitrary transformations depending on the print_mode
  5478 (cf. Output.add_mode -- the first active mode that provides a output
  5479 function wins).  Already formatted output may be embedded into further
  5480 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5481 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5482 accommodate easy composition of diagnostic messages etc.  Programmers
  5483 rarely need to care about Output.output or Output.raw at all, with
  5484 some notable exceptions: Output.output is required when bypassing the
  5485 standard channels (writeln etc.), or in token translations to produce
  5486 properly formatted results; Output.raw is required when capturing
  5487 already output material that will eventually be presented to the user
  5488 a second time.  For the default print mode, both Output.output and
  5489 Output.raw have no effect.
  5490 
  5491 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5492 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5493 cumulative results are displayed at the end of a batch session.
  5494 
  5495 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5496 replaced by File.platform_path and File.shell_path (with appropriate
  5497 hooks).  This provides a clean interface for unusual systems where the
  5498 internal and external process view of file names are different.
  5499 
  5500 * Pure: more efficient orders for basic syntactic entities: added
  5501 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5502 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5503 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5504 orders now -- potential INCOMPATIBILITY for code that depends on a
  5505 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5506 Library.sort_strings on result).
  5507 
  5508 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5509 fold_types traverse types/terms from left to right, observing natural
  5510 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5511 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5512 
  5513 * Pure: name spaces have been refined, with significant changes of the
  5514 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5515 to extern(_table).  The plain name entry path is superceded by a
  5516 general 'naming' context, which also includes the 'policy' to produce
  5517 a fully qualified name and external accesses of a fully qualified
  5518 name; NameSpace.extend is superceded by context dependent
  5519 Sign.declare_name.  Several theory and proof context operations modify
  5520 the naming context.  Especially note Theory.restore_naming and
  5521 ProofContext.restore_naming to get back to a sane state; note that
  5522 Theory.add_path is no longer sufficient to recover from
  5523 Theory.absolute_path in particular.
  5524 
  5525 * Pure: new flags short_names (default false) and unique_names
  5526 (default true) for controlling output of qualified names.  If
  5527 short_names is set, names are printed unqualified.  If unique_names is
  5528 reset, the name prefix is reduced to the minimum required to achieve
  5529 the original result when interning again, even if there is an overlap
  5530 with earlier declarations.
  5531 
  5532 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5533 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5534 (useful for printing error messages).  INCOMPATIBILITY.
  5535 
  5536 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5537 Theory.theory are now identified, referring to the universal
  5538 Context.theory (see Pure/context.ML).  Actual signature and theory
  5539 content is managed as theory data.  The old code and interfaces were
  5540 spread over many files and structures; the new arrangement introduces
  5541 considerable INCOMPATIBILITY to gain more clarity:
  5542 
  5543   Context -- theory management operations (name, identity, inclusion,
  5544     parents, ancestors, merge, etc.), plus generic theory data;
  5545 
  5546   Sign -- logical signature and syntax operations (declaring consts,
  5547     types, etc.), plus certify/read for common entities;
  5548 
  5549   Theory -- logical theory operations (stating axioms, definitions,
  5550     oracles), plus a copy of logical signature operations (consts,
  5551     types, etc.); also a few basic management operations (Theory.copy,
  5552     Theory.merge, etc.)
  5553 
  5554 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5555 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5556 for convenience -- they merely return the theory.
  5557 
  5558 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5559 
  5560 * Pure: the Isar proof context type is already defined early in Pure
  5561 as Context.proof (note that ProofContext.context and Proof.context are
  5562 aliases, where the latter is the preferred name).  This enables other
  5563 Isabelle components to refer to that type even before Isar is present.
  5564 
  5565 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5566 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5567 any of these kinds.  For example, Sign.intern typeK is now
  5568 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5569 Theory.hide_types.  Also note that former
  5570 Theory.hide_classes/types/consts are now
  5571 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5572 internalize their arguments!  INCOMPATIBILITY.
  5573 
  5574 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5575 datatype thmref (with constructors Name and NameSelection) instead of
  5576 plain string -- INCOMPATIBILITY;
  5577 
  5578 * Pure: cases produced by proof methods specify options, where NONE
  5579 means to remove case bindings -- INCOMPATIBILITY in
  5580 (RAW_)METHOD_CASES.
  5581 
  5582 * Pure: the following operations retrieve axioms or theorems from a
  5583 theory node or theory hierarchy, respectively:
  5584 
  5585   Theory.axioms_of: theory -> (string * term) list
  5586   Theory.all_axioms_of: theory -> (string * term) list
  5587   PureThy.thms_of: theory -> (string * thm) list
  5588   PureThy.all_thms_of: theory -> (string * thm) list
  5589 
  5590 * Pure: print_tac now outputs the goal through the trace channel.
  5591 
  5592 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5593 Reference Toplevel.debug (default false) controls detailed printing
  5594 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5595 controls execution profiling -- set to 1 for time and 2 for space
  5596 (both increase the runtime).
  5597 
  5598 * Isar session: The initial use of ROOT.ML is now always timed,
  5599 i.e. the log will show the actual process times, in contrast to the
  5600 elapsed wall-clock time that the outer shell wrapper produces.
  5601 
  5602 * Simplifier: improved handling of bound variables (nameless
  5603 representation, avoid allocating new strings).  Simprocs that invoke
  5604 the Simplifier recursively should use Simplifier.inherit_bounds to
  5605 avoid local name clashes.  Failure to do so produces warnings
  5606 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5607 for further details.
  5608 
  5609 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5610 bindings for all theorems stored within a given theory; this may help
  5611 in porting non-Isar theories to Isar ones, while keeping ML proof
  5612 scripts for the time being.
  5613 
  5614 * ML operator HTML.with_charset specifies the charset begin used for
  5615 generated HTML files.  For example:
  5616 
  5617   HTML.with_charset "utf-8" use_thy "Hebrew";
  5618   HTML.with_charset "utf-8" use_thy "Chinese";
  5619 
  5620 
  5621 *** System ***
  5622 
  5623 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5624 isabelle, isatool etc.).
  5625 
  5626 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5627 isatool doc, isatool mkdir, display_drafts etc.).
  5628 
  5629 * isatool usedir: option -f allows specification of the ML file to be
  5630 used by Isabelle; default is ROOT.ML.
  5631 
  5632 * New isatool version outputs the version identifier of the Isabelle
  5633 distribution being used.
  5634 
  5635 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5636 (containing Boolean satisfiability problems) into Isabelle/HOL
  5637 theories.
  5638 
  5639 
  5640 
  5641 New in Isabelle2004 (April 2004)
  5642 --------------------------------
  5643 
  5644 *** General ***
  5645 
  5646 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5647   Replaces linorder.ML.
  5648 
  5649 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5650   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5651   (\<a>...\<z>), are now considered normal letters, and can therefore
  5652   be used anywhere where an ASCII letter (a...zA...Z) has until
  5653   now. COMPATIBILITY: This obviously changes the parsing of some
  5654   terms, especially where a symbol has been used as a binder, say
  5655   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5656   as an identifier.  Fix it by inserting a space around former
  5657   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5658   existing theory and ML files.
  5659 
  5660 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5661 
  5662 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5663   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5664   a normal (but invisible) letter. For multiple letter subscripts repeat
  5665   \<^isub> like this: x\<^isub>1\<^isub>2.
  5666 
  5667 * Pure: There are now sub-/superscripts that can span more than one
  5668   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5669   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5670   superscript. The new control characters are not identifier parts.
  5671 
  5672 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5673   content of "..." to the latex file instead of \isacntrl... . The "..."
  5674   may consist of any printable characters excluding the end bracket >.
  5675 
  5676 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5677   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5678   declare constants "final", which prevents their being given a definition
  5679   later.  It is useful for constants whose behaviour is fixed axiomatically
  5680   rather than definitionally, such as the meta-logic connectives.
  5681 
  5682 * Pure: 'instance' now handles general arities with general sorts
  5683   (i.e. intersections of classes),
  5684 
  5685 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5686   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5687   It can be changed to alter the colors/layout of generated pages.
  5688 
  5689 
  5690 *** Isar ***
  5691 
  5692 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5693   cut_tac, subgoal_tac and thin_tac:
  5694   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5695     locales are no longer forced to write Isar proof scripts.
  5696     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5697     emulations.
  5698   - INCOMPATIBILITY: names of variables to be instantiated may no
  5699     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5700     This is consistent with the instantiation attribute "where".
  5701 
  5702 * Attributes "where" and "of":
  5703   - Now take type variables of instantiated theorem into account when reading
  5704     the instantiation string.  This fixes a bug that caused instantiated
  5705     theorems to have too special types in some circumstances.
  5706   - "where" permits explicit instantiations of type variables.
  5707 
  5708 * Calculation commands "moreover" and "also" no longer interfere with
  5709   current facts ("this"), admitting arbitrary combinations with "then"
  5710   and derived forms.
  5711 
  5712 * Locales:
  5713   - Goal statements involving the context element "includes" no longer
  5714     generate theorems with internal delta predicates (those ending on
  5715     "_axioms") in the premise.
  5716     Resolve particular premise with <locale>.intro to obtain old form.
  5717   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5718     specification and "includes" elements in goal statement.
  5719   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5720     [intro?] and [elim?] (respectively) by default.
  5721   - Experimental command for instantiation of locales in proof contexts:
  5722         instantiate <label>[<attrs>]: <loc>
  5723     Instantiates locale <loc> and adds all its theorems to the current context
  5724     taking into account their attributes.  Label and attrs are optional
  5725     modifiers, like in theorem declarations.  If present, names of
  5726     instantiated theorems are qualified with <label>, and the attributes
  5727     <attrs> are applied after any attributes these theorems might have already.
  5728       If the locale has assumptions, a chained fact of the form
  5729     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5730     are derived.  The command does not support old-style locales declared
  5731     with "locale (open)".
  5732       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5733 
  5734 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5735   (Isar) contexts.
  5736 
  5737 
  5738 *** HOL ***
  5739 
  5740 * Proof import: new image HOL4 contains the imported library from
  5741   the HOL4 system with about 2500 theorems. It is imported by
  5742   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5743   can be used like any other Isabelle image.  See
  5744   HOL/Import/HOL/README for more information.
  5745 
  5746 * Simplifier:
  5747   - Much improved handling of linear and partial orders.
  5748     Reasoners for linear and partial orders are set up for type classes
  5749     "linorder" and "order" respectively, and are added to the default simpset
  5750     as solvers.  This means that the simplifier can build transitivity chains
  5751     to solve goals from the assumptions.
  5752   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5753     of blast or auto after simplification become unnecessary because the goal
  5754     is solved by simplification already.
  5755 
  5756 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5757     all proved in axiomatic type classes for semirings, rings and fields.
  5758 
  5759 * Numerics:
  5760   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5761     now formalized using the Ring_and_Field theory mentioned above.
  5762   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5763     than before, because now they are set up once in a generic manner.
  5764   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5765     Look for the general versions in Ring_and_Field (and Power if they concern
  5766     exponentiation).
  5767 
  5768 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5769 
  5770 * Records:
  5771   - Record types are now by default printed with their type abbreviation
  5772     instead of the list of all field types. This can be configured via
  5773     the reference "print_record_type_abbr".
  5774   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5775     (not enabled by default).
  5776   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5777     EX x. x = sel r to True (not enabled by default).
  5778   - Tactic "record_split_simp_tac" to split and simplify records added.
  5779 
  5780 * 'specification' command added, allowing for definition by
  5781   specification.  There is also an 'ax_specification' command that
  5782   introduces the new constants axiomatically.
  5783 
  5784 * arith(_tac) is now able to generate counterexamples for reals as well.
  5785 
  5786 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5787 
  5788 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5789   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5790 
  5791 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5792   matrix theory to linear programming.
  5793 
  5794 * Unions and Intersections:
  5795   The latex output syntax of UN and INT has been changed
  5796   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5797   i.e. the index formulae has become a subscript.
  5798   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5799 
  5800 * Unions and Intersections over Intervals:
  5801   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5802   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5803   like in normal math, and corresponding versions for < and for intersection.
  5804 
  5805 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5806   lexicographic dictonary ordering has been added as "lexord".
  5807 
  5808 * ML: the legacy theory structures Int and List have been removed. They had
  5809   conflicted with ML Basis Library structures having the same names.
  5810 
  5811 * 'refute' command added to search for (finite) countermodels.  Only works
  5812   for a fragment of HOL.  The installation of an external SAT solver is
  5813   highly recommended.  See "HOL/Refute.thy" for details.
  5814 
  5815 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5816   formulae under an assignment of free variables to random values.
  5817   In contrast to 'refute', it can deal with inductive datatypes,
  5818   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5819   for examples.
  5820 
  5821 
  5822 *** HOLCF ***
  5823 
  5824 * Streams now come with concatenation and are part of the HOLCF image
  5825 
  5826 
  5827 
  5828 New in Isabelle2003 (May 2003)
  5829 ------------------------------
  5830 
  5831 *** General ***
  5832 
  5833 * Provers/simplifier:
  5834 
  5835   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5836     Assumptions are now subject to complete mutual simplification,
  5837     not just from left to right. The simplifier now preserves
  5838     the order of assumptions.
  5839 
  5840     Potential INCOMPATIBILITY:
  5841 
  5842     -- simp sometimes diverges where the old version did
  5843        not, e.g. invoking simp on the goal
  5844 
  5845         [| P (f x); y = x; f x = f y |] ==> Q
  5846 
  5847        now gives rise to the infinite reduction sequence
  5848 
  5849         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5850 
  5851        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5852        kind of problem.
  5853 
  5854     -- Tactics combining classical reasoner and simplification (such as auto)
  5855        are also affected by this change, because many of them rely on
  5856        simp. They may sometimes diverge as well or yield a different numbers
  5857        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5858        in case of problems. Sometimes subsequent calls to the classical
  5859        reasoner will fail because a preceeding call to the simplifier too
  5860        eagerly simplified the goal, e.g. deleted redundant premises.
  5861 
  5862   - The simplifier trace now shows the names of the applied rewrite rules
  5863 
  5864   - You can limit the number of recursive invocations of the simplifier
  5865     during conditional rewriting (where the simplifie tries to solve the
  5866     conditions before applying the rewrite rule):
  5867     ML "simp_depth_limit := n"
  5868     where n is an integer. Thus you can force termination where previously
  5869     the simplifier would diverge.
  5870 
  5871   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5872 
  5873   - No longer aborts on failed congruence proof.  Instead, the
  5874     congruence is ignored.
  5875 
  5876 * Pure: New generic framework for extracting programs from constructive
  5877   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5878   as HOL/Extraction for some case studies.
  5879 
  5880 * Pure: The main goal of the proof state is no longer shown by default, only
  5881 the subgoals. This behaviour is controlled by a new flag.
  5882    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5883 (ML: Proof.show_main_goal).
  5884 
  5885 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5886 rules whose conclusion matches subgoal 1:
  5887       PG menu: Isabelle/Isar -> Show me -> matching rules
  5888 The rules are ordered by how closely they match the subgoal.
  5889 In particular, rules that solve a subgoal outright are displayed first
  5890 (or rather last, the way they are printed).
  5891 (ML: ProofGeneral.print_intros())
  5892 
  5893 * Pure: New flag trace_unify_fail causes unification to print
  5894 diagnostic information (PG: in trace buffer) when it fails. This is
  5895 useful for figuring out why single step proofs like rule, erule or
  5896 assumption failed.
  5897 
  5898 * Pure: Locale specifications now produce predicate definitions
  5899 according to the body of text (covering assumptions modulo local
  5900 definitions); predicate "loc_axioms" covers newly introduced text,
  5901 while "loc" is cumulative wrt. all included locale expressions; the
  5902 latter view is presented only on export into the global theory
  5903 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5904 on the old view without predicates;
  5905 
  5906 * Pure: predefined locales "var" and "struct" are useful for sharing
  5907 parameters (as in CASL, for example); just specify something like
  5908 ``var x + var y + struct M'' as import;
  5909 
  5910 * Pure: improved thms_containing: proper indexing of facts instead of
  5911 raw theorems; check validity of results wrt. current name space;
  5912 include local facts of proof configuration (also covers active
  5913 locales), cover fixed variables in index; may use "_" in term
  5914 specification; an optional limit for the number of printed facts may
  5915 be given (the default is 40);
  5916 
  5917 * Pure: disallow duplicate fact bindings within new-style theory files
  5918 (batch-mode only);
  5919 
  5920 * Provers: improved induct method: assumptions introduced by case
  5921 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5922 the goal statement); "foo" still refers to all facts collectively;
  5923 
  5924 * Provers: the function blast.overloaded has been removed: all constants
  5925 are regarded as potentially overloaded, which improves robustness in exchange
  5926 for slight decrease in efficiency;
  5927 
  5928 * Provers/linorder: New generic prover for transitivity reasoning over
  5929 linear orders.  Note: this prover is not efficient!
  5930 
  5931 * Isar: preview of problems to finish 'show' now produce an error
  5932 rather than just a warning (in interactive mode);
  5933 
  5934 
  5935 *** HOL ***
  5936 
  5937 * arith(_tac)
  5938 
  5939  - Produces a counter example if it cannot prove a goal.
  5940    Note that the counter example may be spurious if the goal is not a formula
  5941    of quantifier-free linear arithmetic.
  5942    In ProofGeneral the counter example appears in the trace buffer.
  5943 
  5944  - Knows about div k and mod k where k is a numeral of type nat or int.
  5945 
  5946  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5947    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5948    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5949 
  5950 * simp's arithmetic capabilities have been enhanced a bit: it now
  5951 takes ~= in premises into account (by performing a case split);
  5952 
  5953 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5954 are distributed over a sum of terms;
  5955 
  5956 * New tactic "trans_tac" and method "trans" instantiate
  5957 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5958 "<=", "<" and "=").
  5959 
  5960 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5961 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5962 
  5963 * 'typedef' command has new option "open" to suppress the set
  5964 definition;
  5965 
  5966 * functions Min and Max on finite sets have been introduced (theory
  5967 Finite_Set);
  5968 
  5969 * attribute [symmetric] now works for relations as well; it turns
  5970 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5971 
  5972 * induct over a !!-quantified statement (say !!x1..xn):
  5973   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5974 
  5975 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5976 %x. None. Warning: empty_def now refers to the previously hidden definition
  5977 of the empty set.
  5978 
  5979 * Algebra: formalization of classical algebra.  Intended as base for
  5980 any algebraic development in Isabelle.  Currently covers group theory
  5981 (up to Sylow's theorem) and ring theory (Universal Property of
  5982 Univariate Polynomials).  Contributions welcome;
  5983 
  5984 * GroupTheory: deleted, since its material has been moved to Algebra;
  5985 
  5986 * Complex: new directory of the complex numbers with numeric constants,
  5987 nonstandard complex numbers, and some complex analysis, standard and
  5988 nonstandard (Jacques Fleuriot);
  5989 
  5990 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5991 
  5992 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5993 Fleuriot);
  5994 
  5995 * Real/HahnBanach: updated and adapted to locales;
  5996 
  5997 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5998 Gray and Kramer);
  5999 
  6000 * UNITY: added the Meier-Sanders theory of progress sets;
  6001 
  6002 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6003 as abstract algorithms, instantiated to the JVM;
  6004 
  6005 * Bali: Java source language formalization. Type system, operational
  6006 semantics, axiomatic semantics. Supported language features:
  6007 classes, interfaces, objects,virtual methods, static methods,
  6008 static/instance fields, arrays, access modifiers, definite
  6009 assignment, exceptions.
  6010 
  6011 
  6012 *** ZF ***
  6013 
  6014 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6015 universe, etc.);
  6016 
  6017 * Main ZF: virtually all theories converted to new-style format;
  6018 
  6019 
  6020 *** ML ***
  6021 
  6022 * Pure: Tactic.prove provides sane interface for internal proofs;
  6023 omits the infamous "standard" operation, so this is more appropriate
  6024 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6025 
  6026 * Pure: improved error reporting of simprocs;
  6027 
  6028 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6029 up simprocs;
  6030 
  6031 
  6032 *** Document preparation ***
  6033 
  6034 * uses \par instead of \\ for line breaks in theory text. This may
  6035 shift some page breaks in large documents. To get the old behaviour
  6036 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6037 
  6038 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6039 other packages
  6040 
  6041 * \<euro> now needs package babel/greek instead of marvosym (which
  6042 broke \Rightarrow)
  6043 
  6044 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6045 textcomp package)
  6046 
  6047 
  6048 
  6049 New in Isabelle2002 (March 2002)
  6050 --------------------------------
  6051 
  6052 *** Document preparation ***
  6053 
  6054 * greatly simplified document preparation setup, including more
  6055 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6056 instructive isatool mkdir; users should basically be able to get
  6057 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6058 users may run a separate document processing stage manually like this:
  6059 "isatool usedir -D output HOL Test && isatool document Test/output";
  6060 
  6061 * theory dependency graph may now be incorporated into documents;
  6062 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6063 with \includegraphics of LaTeX;
  6064 
  6065 * proper spacing of consecutive markup elements, especially text
  6066 blocks after section headings;
  6067 
  6068 * support bold style (for single symbols only), input syntax is like
  6069 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6070 
  6071 * \<bullet> is now output as bold \cdot by default, which looks much
  6072 better in printed text;
  6073 
  6074 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6075 note that these symbols are currently unavailable in Proof General /
  6076 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6077 
  6078 * isatool latex no longer depends on changed TEXINPUTS, instead
  6079 isatool document copies the Isabelle style files to the target
  6080 location;
  6081 
  6082 
  6083 *** Isar ***
  6084 
  6085 * Pure/Provers: improved proof by cases and induction;
  6086   - 'case' command admits impromptu naming of parameters (such as
  6087     "case (Suc n)");
  6088   - 'induct' method divinates rule instantiation from the inductive
  6089     claim; no longer requires excessive ?P bindings for proper
  6090     instantiation of cases;
  6091   - 'induct' method properly enumerates all possibilities of set/type
  6092     rules; as a consequence facts may be also passed through *type*
  6093     rules without further ado;
  6094   - 'induct' method now derives symbolic cases from the *rulified*
  6095     rule (before it used to rulify cases stemming from the internal
  6096     atomized version); this means that the context of a non-atomic
  6097     statement becomes is included in the hypothesis, avoiding the
  6098     slightly cumbersome show "PROP ?case" form;
  6099   - 'induct' may now use elim-style induction rules without chaining
  6100     facts, using ``missing'' premises from the goal state; this allows
  6101     rules stemming from inductive sets to be applied in unstructured
  6102     scripts, while still benefitting from proper handling of non-atomic
  6103     statements; NB: major inductive premises need to be put first, all
  6104     the rest of the goal is passed through the induction;
  6105   - 'induct' proper support for mutual induction involving non-atomic
  6106     rule statements (uses the new concept of simultaneous goals, see
  6107     below);
  6108   - append all possible rule selections, but only use the first
  6109     success (no backtracking);
  6110   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6111   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6112   - added 'print_induct_rules' (covered by help item in recent Proof
  6113     General versions);
  6114   - moved induct/cases attributes to Pure, methods to Provers;
  6115   - generic method setup instantiated for FOL and HOL;
  6116 
  6117 * Pure: support multiple simultaneous goal statements, for example
  6118 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6119 meta-level mechanism, this acts as if several individual goals had
  6120 been stated separately; in particular common proof methods need to be
  6121 repeated in order to cover all claims; note that a single elimination
  6122 step is *not* sufficient to establish the two conjunctions, so this
  6123 fails:
  6124 
  6125   assume "A & B" then have A and B ..   (*".." fails*)
  6126 
  6127 better use "obtain" in situations as above; alternative refer to
  6128 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6129 
  6130 * Pure: proper integration with ``locales''; unlike the original
  6131 version by Florian Kammller, Isar locales package high-level proof
  6132 contexts rather than raw logical ones (e.g. we admit to include
  6133 attributes everywhere); operations on locales include merge and
  6134 rename; support for implicit arguments (``structures''); simultaneous
  6135 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6136 some examples;
  6137 
  6138 * Pure: the following commands have been ``localized'', supporting a
  6139 target locale specification "(in name)": 'lemma', 'theorem',
  6140 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6141 stored both within the locale and at the theory level (exported and
  6142 qualified by the locale name);
  6143 
  6144 * Pure: theory goals may now be specified in ``long'' form, with
  6145 ad-hoc contexts consisting of arbitrary locale elements. for example
  6146 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6147 definitions may be given, too); the result is a meta-level rule with
  6148 the context elements being discharged in the obvious way;
  6149 
  6150 * Pure: new proof command 'using' allows to augment currently used
  6151 facts after a goal statement ('using' is syntactically analogous to
  6152 'apply', but acts on the goal's facts only); this allows chained facts
  6153 to be separated into parts given before and after a claim, as in
  6154 ``from a and b have C using d and e <proof>'';
  6155 
  6156 * Pure: renamed "antecedent" case to "rule_context";
  6157 
  6158 * Pure: new 'judgment' command records explicit information about the
  6159 object-logic embedding (used by several tools internally); no longer
  6160 use hard-wired "Trueprop";
  6161 
  6162 * Pure: added 'corollary' command;
  6163 
  6164 * Pure: fixed 'token_translation' command;
  6165 
  6166 * Pure: removed obsolete 'exported' attribute;
  6167 
  6168 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6169 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6170 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6171 
  6172 * Pure: method 'atomize' presents local goal premises as object-level
  6173 statements (atomic meta-level propositions); setup controlled via
  6174 rewrite rules declarations of 'atomize' attribute; example
  6175 application: 'induct' method with proper rule statements in improper
  6176 proof *scripts*;
  6177 
  6178 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6179 now consider the syntactic context of assumptions, giving a better
  6180 chance to get type-inference of the arguments right (this is
  6181 especially important for locales);
  6182 
  6183 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6184 mode;
  6185 
  6186 * Pure/obtain: the formal conclusion "thesis", being marked as
  6187 ``internal'', may no longer be reference directly in the text;
  6188 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6189 situations;
  6190 
  6191 * Pure: generic 'sym' attribute which declares a rule both as pure
  6192 'elim?' and for the 'symmetric' operation;
  6193 
  6194 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6195 text; the fixed correlation with particular command syntax has been
  6196 discontinued;
  6197 
  6198 * Pure: new method 'rules' is particularly well-suited for proof
  6199 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6200 but often produces more compact proof terms with less detours;
  6201 
  6202 * Pure/Provers/classical: simplified integration with pure rule
  6203 attributes and methods; the classical "intro?/elim?/dest?"
  6204 declarations coincide with the pure ones; the "rule" method no longer
  6205 includes classically swapped intros; "intro" and "elim" methods no
  6206 longer pick rules from the context; also got rid of ML declarations
  6207 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6208 INCOMPATIBILITY;
  6209 
  6210 * Provers/classical: attribute 'swapped' produces classical inversions
  6211 of introduction rules;
  6212 
  6213 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6214 rules instead of full simplifier context; 'iff' attribute handles
  6215 conditional rules;
  6216 
  6217 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6218 
  6219 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6220 "(permissive)" option to recover old behavior;
  6221 
  6222 * HOL: 'inductive' no longer features separate (collective) attributes
  6223 for 'intros' (was found too confusing);
  6224 
  6225 * HOL: properly declared induction rules less_induct and
  6226 wf_induct_rule;
  6227 
  6228 
  6229 *** HOL ***
  6230 
  6231 * HOL: moved over to sane numeral syntax; the new policy is as
  6232 follows:
  6233 
  6234   - 0 and 1 are polymorphic constants, which are defined on any
  6235   numeric type (nat, int, real etc.);
  6236 
  6237   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6238   binary representation internally;
  6239 
  6240   - type nat has special constructor Suc, and generally prefers Suc 0
  6241   over 1::nat and Suc (Suc 0) over 2::nat;
  6242 
  6243 This change may cause significant problems of INCOMPATIBILITY; here
  6244 are some hints on converting existing sources:
  6245 
  6246   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6247   entities, so expressions involving "-" (unary or binary minus) need
  6248   to be spaced properly;
  6249 
  6250   - existing occurrences of "1" may need to be constraint "1::nat" or
  6251   even replaced by Suc 0; similar for old "2";
  6252 
  6253   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6254 
  6255   - remove all special provisions on numerals in proofs;
  6256 
  6257 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6258 representation (depends on bin_arith_simps in the default context);
  6259 
  6260 * HOL: symbolic syntax for x^2 (numeral 2);
  6261 
  6262 * HOL: the class of all HOL types is now called "type" rather than
  6263 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6264 in axclass/classes, instance/arities, and (usually rare) occurrences
  6265 in typings (of consts etc.); internally the class is called
  6266 "HOL.type", ML programs should refer to HOLogic.typeS;
  6267 
  6268 * HOL/record package improvements:
  6269   - new derived operations "fields" to build a partial record section,
  6270     "extend" to promote a fixed record to a record scheme, and
  6271     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6272     declared as simp by default;
  6273   - shared operations ("more", "fields", etc.) now need to be always
  6274     qualified) --- potential INCOMPATIBILITY;
  6275   - removed "make_scheme" operations (use "make" with "extend") --
  6276     INCOMPATIBILITY;
  6277   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6278   - provides cases/induct rules for use with corresponding Isar
  6279     methods (for concrete records, record schemes, concrete more
  6280     parts, and schematic more parts -- in that order);
  6281   - internal definitions directly based on a light-weight abstract
  6282     theory of product types over typedef rather than datatype;
  6283 
  6284 * HOL: generic code generator for generating executable ML code from
  6285 specifications; specific support for HOL constructs such as inductive
  6286 datatypes and sets, as well as recursive functions; can be invoked
  6287 via 'generate_code' theory section;
  6288 
  6289 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6290 
  6291 * HOL: consolidated and renamed several theories.  In particular:
  6292         Ord.thy has been absorbed into HOL.thy
  6293         String.thy has been absorbed into List.thy
  6294 
  6295 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6296 (beware of argument permutation!);
  6297 
  6298 * HOL: linorder_less_split superseded by linorder_cases;
  6299 
  6300 * HOL/List: "nodups" renamed to "distinct";
  6301 
  6302 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6303 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6304   - Ex_def has changed, now need to use some_eq_ex
  6305 
  6306 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6307 in this (rare) case use:
  6308 
  6309   delSWrapper "split_all_tac"
  6310   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6311 
  6312 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6313 MAY FAIL;
  6314 
  6315 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6316 Isabelle's type classes, ^ on functions and relations has too general
  6317 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6318 necessary to attach explicit type constraints;
  6319 
  6320 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6321 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6322 renamed accordingly (eg "compI" -> "rel_compI").
  6323 
  6324 * HOL: syntax translations now work properly with numerals and records
  6325 expressions;
  6326 
  6327 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6328 of "lam" -- INCOMPATIBILITY;
  6329 
  6330 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6331 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6332 renamed "Product_Type.unit";
  6333 
  6334 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6335 
  6336 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6337 the "cases" method);
  6338 
  6339 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6340 Florian Kammller);
  6341 
  6342 * HOL/IMP: updated and converted to new-style theory format; several
  6343 parts turned into readable document, with proper Isar proof texts and
  6344 some explanations (by Gerwin Klein);
  6345 
  6346 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6347 
  6348 * HOL-Hyperreal is now a logic image;
  6349 
  6350 
  6351 *** HOLCF ***
  6352 
  6353 * Isar: consts/constdefs supports mixfix syntax for continuous
  6354 operations;
  6355 
  6356 * Isar: domain package adapted to new-style theory format, e.g. see
  6357 HOLCF/ex/Dnat.thy;
  6358 
  6359 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6360 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6361 lift.induct_tac, always use UU instead of Undef;
  6362 
  6363 * HOLCF/IMP: updated and converted to new-style theory;
  6364 
  6365 
  6366 *** ZF ***
  6367 
  6368 * Isar: proper integration of logic-specific tools and packages,
  6369 including theory commands '(co)inductive', '(co)datatype',
  6370 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6371 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6372 
  6373 * theory Main no longer includes AC; for the Axiom of Choice, base
  6374 your theory on Main_ZFC;
  6375 
  6376 * the integer library now covers quotients and remainders, with many
  6377 laws relating division to addition, multiplication, etc.;
  6378 
  6379 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6380 typeless version of the formalism;
  6381 
  6382 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6383 format;
  6384 
  6385 * ZF/Induct: new directory for examples of inductive definitions,
  6386 including theory Multiset for multiset orderings; converted to
  6387 new-style theory format;
  6388 
  6389 * ZF: many new theorems about lists, ordinals, etc.;
  6390 
  6391 
  6392 *** General ***
  6393 
  6394 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6395 variable proof controls level of detail: 0 = no proofs (only oracle
  6396 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6397 also ref manual for further ML interfaces;
  6398 
  6399 * Pure/axclass: removed obsolete ML interface
  6400 goal_subclass/goal_arity;
  6401 
  6402 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6403 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6404 separate tokens, so expressions involving minus need to be spaced
  6405 properly;
  6406 
  6407 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6408 rather than "infixl" or "infixr";
  6409 
  6410 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6411 sort constraint specifications in type inference; e.g. "x::_::foo"
  6412 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6413 type variable);
  6414 
  6415 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6416 control output of nested => (types); the default behavior is
  6417 "type_brackets";
  6418 
  6419 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6420 tokens into AST constants;
  6421 
  6422 * Pure/syntax: prefer later declarations of translations and print
  6423 translation functions; potential INCOMPATIBILITY: need to reverse
  6424 multiple declarations for same syntax element constant;
  6425 
  6426 * Pure/show_hyps reset by default (in accordance to existing Isar
  6427 practice);
  6428 
  6429 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6430 addSafter;
  6431 
  6432 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6433 as well;
  6434 
  6435 * system: tested support for MacOS X; should be able to get Isabelle +
  6436 Proof General to work in a plain Terminal after installing Poly/ML
  6437 (e.g. from the Isabelle distribution area) and GNU bash alone
  6438 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6439 support requires further installations, e.g. from
  6440 http://fink.sourceforge.net/);
  6441 
  6442 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6443 
  6444 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6445 of 40 MB), cf. ML_OPTIONS;
  6446 
  6447 * system: Proof General keywords specification is now part of the
  6448 Isabelle distribution (see etc/isar-keywords.el);
  6449 
  6450 * system: support for persistent Proof General sessions (refrain from
  6451 outdating all loaded theories on startup); user may create writable
  6452 logic images like this: ``isabelle -q HOL Test'';
  6453 
  6454 * system: smart selection of Isabelle process versus Isabelle
  6455 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6456 run both "isabelle" and "Isabelle" even if file names are badly
  6457 damaged (executable inspects the case of the first letter of its own
  6458 name); added separate "isabelle-process" and "isabelle-interface";
  6459 
  6460 * system: refrain from any attempt at filtering input streams; no
  6461 longer support ``8bit'' encoding of old isabelle font, instead proper
  6462 iso-latin characters may now be used; the related isatools
  6463 "symbolinput" and "nonascii" have disappeared as well;
  6464 
  6465 * system: removed old "xterm" interface (the print modes "xterm" and
  6466 "xterm_color" are still available for direct use in a suitable
  6467 terminal);
  6468 
  6469 
  6470 
  6471 New in Isabelle99-2 (February 2001)
  6472 -----------------------------------
  6473 
  6474 *** Overview of INCOMPATIBILITIES ***
  6475 
  6476 * HOL: please note that theories in the Library and elsewhere often use the
  6477 new-style (Isar) format; to refer to their theorems in an ML script you must
  6478 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6479 
  6480 * HOL: inductive package no longer splits induction rule aggressively,
  6481 but only as far as specified by the introductions given; the old
  6482 format may be recovered via ML function complete_split_rule or attribute
  6483 'split_rule (complete)';
  6484 
  6485 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6486 gfp_Tarski to gfp_unfold;
  6487 
  6488 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6489 
  6490 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6491 relation); infix "^^" has been renamed "``"; infix "``" has been
  6492 renamed "`"; "univalent" has been renamed "single_valued";
  6493 
  6494 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6495 operation;
  6496 
  6497 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6498 
  6499 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6500 
  6501 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6502 consequence, it is no longer monotonic wrt. the local goal context
  6503 (which is now passed through the inductive cases);
  6504 
  6505 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6506 \<gg> to \<ggreater>;
  6507 
  6508 
  6509 *** Document preparation ***
  6510 
  6511 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6512 available: are "it" for near math-mode best-style output, "sl" for
  6513 slanted text style, and "tt" for plain type-writer; if no
  6514 \isabellestyle command is given, output is according to slanted
  6515 type-writer);
  6516 
  6517 * support sub/super scripts (for single symbols only), input syntax is
  6518 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6519 
  6520 * some more standard symbols; see Appendix A of the system manual for
  6521 the complete list of symbols defined in isabellesym.sty;
  6522 
  6523 * improved isabelle style files; more abstract symbol implementation
  6524 (should now use \isamath{...} and \isatext{...} in custom symbol
  6525 definitions);
  6526 
  6527 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6528 state; Note that presentation of goal states does not conform to
  6529 actual human-readable proof documents.  Please do not include goal
  6530 states into document output unless you really know what you are doing!
  6531 
  6532 * proper indentation of antiquoted output with proportional LaTeX
  6533 fonts;
  6534 
  6535 * no_document ML operator temporarily disables LaTeX document
  6536 generation;
  6537 
  6538 * isatool unsymbolize tunes sources for plain ASCII communication;
  6539 
  6540 
  6541 *** Isar ***
  6542 
  6543 * Pure: Isar now suffers initial goal statements to contain unbound
  6544 schematic variables (this does not conform to actual readable proof
  6545 documents, due to unpredictable outcome and non-compositional proof
  6546 checking); users who know what they are doing may use schematic goals
  6547 for Prolog-style synthesis of proven results;
  6548 
  6549 * Pure: assumption method (an implicit finishing) now handles actual
  6550 rules as well;
  6551 
  6552 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6553 initial goal, declare "that" only as Pure intro (only for single
  6554 steps); the "that" rule assumption may now be involved in implicit
  6555 finishing, thus ".." becomes a feasible for trivial obtains;
  6556 
  6557 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6558 instance proofs may be performed by "..";
  6559 
  6560 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6561 statements as well;
  6562 
  6563 * Pure: more robust selection of calculational rules;
  6564 
  6565 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6566 rule (as well as the assumption rule);
  6567 
  6568 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6569 lemmas, using the graph browser tool;
  6570 
  6571 * Pure: predict failure of "show" in interactive mode;
  6572 
  6573 * Pure: 'thms_containing' now takes actual terms as arguments;
  6574 
  6575 * HOL: improved method 'induct' --- now handles non-atomic goals
  6576 (potential INCOMPATIBILITY); tuned error handling;
  6577 
  6578 * HOL: cases and induct rules now provide explicit hints about the
  6579 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6580 any remaining facts are inserted into the goal verbatim;
  6581 
  6582 * HOL: local contexts (aka cases) may now contain term bindings as
  6583 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6584 the result to be shown in each case;
  6585 
  6586 * HOL: added 'recdef_tc' command;
  6587 
  6588 * isatool convert assists in eliminating legacy ML scripts;
  6589 
  6590 
  6591 *** HOL ***
  6592 
  6593 * HOL/Library: a collection of generic theories to be used together
  6594 with main HOL; the theory loader path already includes this directory
  6595 by default; the following existing theories have been moved here:
  6596 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6597 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6598 
  6599 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6600 modelling and verification task performed in Isabelle/HOL +
  6601 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6602 
  6603 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6604 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6605 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6606 'domain', this makes the theory consistent with mathematical
  6607 literature;
  6608 
  6609 * HOL basics: added overloaded operations "inverse" and "divide"
  6610 (infix "/"), syntax for generic "abs" operation, generic summation
  6611 operator \<Sum>;
  6612 
  6613 * HOL/typedef: simplified package, provide more useful rules (see also
  6614 HOL/subset.thy);
  6615 
  6616 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6617 now expressed as a proper nested rule (old-style tactic scripts may
  6618 require atomize_strip_tac to cope with non-atomic premises);
  6619 
  6620 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6621 to "split_conv" (old name still available for compatibility);
  6622 
  6623 * HOL: improved concrete syntax for strings (e.g. allows translation
  6624 rules with string literals);
  6625 
  6626 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6627  and Fleuriot's mechanization of analysis, including the transcendental
  6628  functions for the reals;
  6629 
  6630 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6631 
  6632 
  6633 *** CTT ***
  6634 
  6635 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6636 "lam" is displayed as TWO lambda-symbols
  6637 
  6638 * CTT: theory Main now available, containing everything (that is, Bool
  6639 and Arith);
  6640 
  6641 
  6642 *** General ***
  6643 
  6644 * Pure: the Simplifier has been implemented properly as a derived rule
  6645 outside of the actual kernel (at last!); the overall performance
  6646 penalty in practical applications is about 50%, while reliability of
  6647 the Isabelle inference kernel has been greatly improved;
  6648 
  6649 * print modes "brackets" and "no_brackets" control output of nested =>
  6650 (types) and ==> (props); the default behaviour is "brackets";
  6651 
  6652 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6653 as assumptions as well;
  6654 
  6655 * system: support Poly/ML 4.0;
  6656 
  6657 * system: isatool install handles KDE version 1 or 2;
  6658 
  6659 
  6660 
  6661 New in Isabelle99-1 (October 2000)
  6662 ----------------------------------
  6663 
  6664 *** Overview of INCOMPATIBILITIES ***
  6665 
  6666 * HOL: simplification of natural numbers is much changed; to partly
  6667 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6668 issue the following ML commands:
  6669 
  6670   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6671   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6672 
  6673 * HOL: simplification no longer dives into case-expressions; this is
  6674 controlled by "t.weak_case_cong" for each datatype t;
  6675 
  6676 * HOL: nat_less_induct renamed to less_induct;
  6677 
  6678 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6679 fixsome to patch .thy and .ML sources automatically;
  6680 
  6681   select_equality  -> some_equality
  6682   select_eq_Ex     -> some_eq_ex
  6683   selectI2EX       -> someI2_ex
  6684   selectI2         -> someI2
  6685   selectI          -> someI
  6686   select1_equality -> some1_equality
  6687   Eps_sym_eq       -> some_sym_eq_trivial
  6688   Eps_eq           -> some_eq_trivial
  6689 
  6690 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6691 
  6692 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6693 instead);
  6694 
  6695 * HOL: the recursion equations generated by 'recdef' are now called
  6696 f.simps instead of f.rules;
  6697 
  6698 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6699 
  6700 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6701 sometimes be needed;
  6702 
  6703 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6704 
  6705 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6706 
  6707 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6708 product is now "<*>" instead of "Times"; the lexicographic product is
  6709 now "<*lex*>" instead of "**";
  6710 
  6711 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6712 of main HOL, but was unused); better use HOL's datatype package;
  6713 
  6714 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6715 the old syntax may be recovered as follows:
  6716 
  6717   syntax (symbols)
  6718     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6719       (infixl "\\<oplus>" 100)
  6720 
  6721 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6722 
  6723 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6724 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6725 internally;
  6726 
  6727 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6728 changed from A/r to A//r;
  6729 
  6730 * ZF: new treatment of arithmetic (nat & int) may break some old
  6731 proofs;
  6732 
  6733 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6734 rulify -> rule_format, elimify -> elim_format, ...);
  6735 
  6736 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6737 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6738 should have to change intro!! to intro? only); replaced "delrule" by
  6739 "rule del";
  6740 
  6741 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6742 
  6743 * Provers: strengthened force_tac by using new first_best_tac;
  6744 
  6745 * LaTeX document preparation: several changes of isabelle.sty (see
  6746 lib/texinputs);
  6747 
  6748 
  6749 *** Document preparation ***
  6750 
  6751 * formal comments (text blocks etc.) in new-style theories may now
  6752 contain antiquotations of thm/prop/term/typ/text to be presented
  6753 according to latex print mode; concrete syntax is like this:
  6754 @{term[show_types] "f(x) = a + x"};
  6755 
  6756 * isatool mkdir provides easy setup of Isabelle session directories,
  6757 including proper document sources;
  6758 
  6759 * generated LaTeX sources are now deleted after successful run
  6760 (isatool document -c); may retain a copy somewhere else via -D option
  6761 of isatool usedir;
  6762 
  6763 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6764 style files, achieving self-contained LaTeX sources and simplifying
  6765 LaTeX debugging;
  6766 
  6767 * old-style theories now produce (crude) LaTeX output as well;
  6768 
  6769 * browser info session directories are now self-contained (may be put
  6770 on WWW server seperately); improved graphs of nested sessions; removed
  6771 graph for 'all sessions';
  6772 
  6773 * several improvements in isabelle style files; \isabellestyle{it}
  6774 produces fake math mode output; \isamarkupheader is now \section by
  6775 default; see lib/texinputs/isabelle.sty etc.;
  6776 
  6777 
  6778 *** Isar ***
  6779 
  6780 * Isar/Pure: local results and corresponding term bindings are now
  6781 subject to Hindley-Milner polymorphism (similar to ML); this
  6782 accommodates incremental type-inference very nicely;
  6783 
  6784 * Isar/Pure: new derived language element 'obtain' supports
  6785 generalized existence reasoning;
  6786 
  6787 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6788 support accumulation of results, without applying any rules yet;
  6789 useful to collect intermediate results without explicit name
  6790 references, and for use with transitivity rules with more than 2
  6791 premises;
  6792 
  6793 * Isar/Pure: scalable support for case-analysis type proofs: new
  6794 'case' language element refers to local contexts symbolically, as
  6795 produced by certain proof methods; internally, case names are attached
  6796 to theorems as "tags";
  6797 
  6798 * Isar/Pure: theory command 'hide' removes declarations from
  6799 class/type/const name spaces;
  6800 
  6801 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6802 indicate potential overloading;
  6803 
  6804 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6805 
  6806 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6807 "{a,b,c}" instead of {a,b,c};
  6808 
  6809 * Isar/Pure now provides its own version of intro/elim/dest
  6810 attributes; useful for building new logics, but beware of confusion
  6811 with the version in Provers/classical;
  6812 
  6813 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6814 case name 'antecedent';
  6815 
  6816 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6817 to the current context is now done automatically);
  6818 
  6819 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6820 for definining proof methods in ML;
  6821 
  6822 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6823 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6824 most cases, one should have to change intro!! to intro? only);
  6825 replaced "delrule" by "rule del";
  6826 
  6827 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6828 'symmetric' attribute (the latter supercedes [RS sym]);
  6829 
  6830 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6831 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6832 well (including splits);
  6833 
  6834 * Isar/Provers: Simplifier and Classical methods now support all kind
  6835 of modifiers used in the past, including 'cong', 'iff', etc.
  6836 
  6837 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6838 of Simplifier and Classical reasoner);
  6839 
  6840 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6841 now support named cases; major packages (inductive, datatype, primrec,
  6842 recdef) support case names and properly name parameters;
  6843 
  6844 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6845 monotonicity conditions are extracted to be proven at end of
  6846 calculations;
  6847 
  6848 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6849 method anyway;
  6850 
  6851 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6852 split_if split_if_asm; datatype package provides theorems foo.splits =
  6853 foo.split foo.split_asm for each datatype;
  6854 
  6855 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6856 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6857 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6858 use "(cases (simplified))" method in proper proof texts);
  6859 
  6860 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6861 
  6862 * Isar: names of theorems etc. may be natural numbers as well;
  6863 
  6864 * Isar: 'pr' command: optional arguments for goals_limit and
  6865 ProofContext.prems_limit; no longer prints theory contexts, but only
  6866 proof states;
  6867 
  6868 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6869 additional print modes to be specified; e.g. "pr(latex)" will print
  6870 proof state according to the Isabelle LaTeX style;
  6871 
  6872 * Isar: improved support for emulating tactic scripts, including proof
  6873 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6874 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6875 (for HOL datatypes);
  6876 
  6877 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6878 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6879 'proof method scripts' have to be in depth-first order;
  6880 
  6881 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6882 
  6883 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6884 should instead use individual commands for printing items
  6885 (print_commands, print_methods etc.);
  6886 
  6887 * Isar: added 'nothing' --- the empty list of theorems;
  6888 
  6889 
  6890 *** HOL ***
  6891 
  6892 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6893 corresponding virtual machine and a specification of its bytecode
  6894 verifier and a lightweight bytecode verifier, including proofs of
  6895 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6896 Cornelia Pusch (see also the homepage of project Bali at
  6897 http://isabelle.in.tum.de/Bali/);
  6898 
  6899 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6900 Clemens Ballarin;
  6901 
  6902 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6903 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6904 Rasmussen;
  6905 
  6906 * HOL/Lattice: fundamental concepts of lattice theory and order
  6907 structures, including duals, properties of bounds versus algebraic
  6908 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6909 Theorem for complete lattices etc.; may also serve as a demonstration
  6910 for abstract algebraic reasoning using axiomatic type classes, and
  6911 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6912 
  6913 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6914 von Oheimb;
  6915 
  6916 * HOL/IMPP: extension of IMP with local variables and mutually
  6917 recursive procedures, by David von Oheimb;
  6918 
  6919 * HOL/Lambda: converted into new-style theory and document;
  6920 
  6921 * HOL/ex/Multiquote: example of multiple nested quotations and
  6922 anti-quotations -- basically a generalized version of de-Bruijn
  6923 representation; very useful in avoiding lifting of operations;
  6924 
  6925 * HOL/record: added general record equality rule to simpset; fixed
  6926 select-update simplification procedure to handle extended records as
  6927 well; admit "r" as field name;
  6928 
  6929 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6930 other numeric types and also as the identity of groups, rings, etc.;
  6931 
  6932 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6933 Types nat and int belong to this axclass;
  6934 
  6935 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6936    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6937    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6938   two terms #m*u and #n*u are replaced by #(m+n)*u
  6939     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6940   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6941     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6942 
  6943 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6944 powerful prover for predicate logic but knows nothing of clasets; see
  6945 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6946 
  6947 * HOL: new version of "case_tac" subsumes both boolean case split and
  6948 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6949 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6950 
  6951 * HOL: simplification no longer dives into case-expressions: only the
  6952 selector expression is simplified, but not the remaining arms; to
  6953 enable full simplification of case-expressions for datatype t, you may
  6954 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6955 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6956 
  6957 * HOL/recdef: the recursion equations generated by 'recdef' for
  6958 function 'f' are now called f.simps instead of f.rules; if all
  6959 termination conditions are proved automatically, these simplification
  6960 rules are added to the simpset, as in primrec; rules may be named
  6961 individually as well, resulting in a separate list of theorems for
  6962 each equation;
  6963 
  6964 * HOL/While is a new theory that provides a while-combinator. It
  6965 permits the definition of tail-recursive functions without the
  6966 provision of a termination measure. The latter is necessary once the
  6967 invariant proof rule for while is applied.
  6968 
  6969 * HOL: new (overloaded) notation for the set of elements below/above
  6970 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6971 
  6972 * HOL: theorems impI, allI, ballI bound as "strip";
  6973 
  6974 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6975 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6976 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6977 
  6978 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6979 
  6980 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6981 main HOL, but was unused);
  6982 
  6983 * HOL: fewer consts declared as global (e.g. have to refer to
  6984 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6985 
  6986 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6987 in case of overlap with user translations (e.g. judgements over
  6988 tuples); (note that the underlying logical represenation is still
  6989 bogus);
  6990 
  6991 
  6992 *** ZF ***
  6993 
  6994 * ZF: simplification automatically cancels common terms in arithmetic
  6995 expressions over nat and int;
  6996 
  6997 * ZF: new treatment of nat to minimize type-checking: all operators
  6998 coerce their operands to a natural number using the function natify,
  6999 making the algebraic laws unconditional;
  7000 
  7001 * ZF: as above, for int: operators coerce their operands to an integer
  7002 using the function intify;
  7003 
  7004 * ZF: the integer library now contains many of the usual laws for the
  7005 orderings, including $<=, and monotonicity laws for $+ and $*;
  7006 
  7007 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7008 simplification;
  7009 
  7010 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7011 to the simplifier and classical reasoner simultaneously;
  7012 
  7013 
  7014 *** General ***
  7015 
  7016 * Provers: blast_tac now handles actual object-logic rules as
  7017 assumptions; note that auto_tac uses blast_tac internally as well;
  7018 
  7019 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7020 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7021 
  7022 * Provers: delrules now handles destruct rules as well (no longer need
  7023 explicit make_elim);
  7024 
  7025 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7026   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7027 use instead the strong form,
  7028   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7029 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7030 from destruct-rules;
  7031 
  7032 * Provers: Simplifier.easy_setup provides a fast path to basic
  7033 Simplifier setup for new object-logics;
  7034 
  7035 * Pure: AST translation rules no longer require constant head on LHS;
  7036 
  7037 * Pure: improved name spaces: ambiguous output is qualified; support
  7038 for hiding of names;
  7039 
  7040 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7041 XSYMBOL_HOME; no longer need to do manual configuration in most
  7042 situations;
  7043 
  7044 * system: compression of ML heaps images may now be controlled via -c
  7045 option of isabelle and isatool usedir (currently only observed by
  7046 Poly/ML);
  7047 
  7048 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7049 useful for remote X11);
  7050 
  7051 * system: provide TAGS file for Isabelle sources;
  7052 
  7053 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7054 order;
  7055 
  7056 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7057 timing flag supersedes proof_timing and Toplevel.trace;
  7058 
  7059 * ML: new combinators |>> and |>>> for incremental transformations
  7060 with secondary results (e.g. certain theory extensions):
  7061 
  7062 * ML: PureThy.add_defs gets additional argument to indicate potential
  7063 overloading (usually false);
  7064 
  7065 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7066 results;
  7067 
  7068 
  7069 
  7070 New in Isabelle99 (October 1999)
  7071 --------------------------------
  7072 
  7073 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7074 
  7075 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7076 are no longer simplified.  (This allows the simplifier to unfold recursive
  7077 functional programs.)  To restore the old behaviour, declare
  7078 
  7079     Delcongs [if_weak_cong];
  7080 
  7081 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7082 complement;
  7083 
  7084 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7085 
  7086 * HOL/datatype: mutual_induct_tac no longer exists --
  7087   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7088 
  7089 * HOL/typedef: fixed type inference for representing set; type
  7090 arguments now have to occur explicitly on the rhs as type constraints;
  7091 
  7092 * ZF: The con_defs part of an inductive definition may no longer refer
  7093 to constants declared in the same theory;
  7094 
  7095 * HOL, ZF: the function mk_cases, generated by the inductive
  7096 definition package, has lost an argument.  To simplify its result, it
  7097 uses the default simpset instead of a supplied list of theorems.
  7098 
  7099 * HOL/List: the constructors of type list are now Nil and Cons;
  7100 
  7101 * Simplifier: the type of the infix ML functions
  7102         setSSolver addSSolver setSolver addSolver
  7103 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7104 for packaging solvers. A solver is created via
  7105         mk_solver: string -> (thm list -> int -> tactic) -> solver
  7106 where the string argument is only a comment.
  7107 
  7108 
  7109 *** Proof tools ***
  7110 
  7111 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7112 decision procedure for linear arithmetic. Currently it is used for
  7113 types `nat', `int', and `real' in HOL (see below); it can, should and
  7114 will be instantiated for other types and logics as well.
  7115 
  7116 * The simplifier now accepts rewrite rules with flexible heads, eg
  7117      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7118   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7119   matching.
  7120 
  7121 
  7122 *** General ***
  7123 
  7124 * New Isabelle/Isar subsystem provides an alternative to traditional
  7125 tactical theorem proving; together with the ProofGeneral/isar user
  7126 interface it offers an interactive environment for developing human
  7127 readable proof documents (Isar == Intelligible semi-automated
  7128 reasoning); for further information see isatool doc isar-ref,
  7129 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7130 
  7131 * improved and simplified presentation of theories: better HTML markup
  7132 (including colors), graph views in several sizes; isatool usedir now
  7133 provides a proper interface for user theories (via -P option); actual
  7134 document preparation based on (PDF)LaTeX is available as well (for
  7135 new-style theories only); see isatool doc system for more information;
  7136 
  7137 * native support for Proof General, both for classic Isabelle and
  7138 Isabelle/Isar;
  7139 
  7140 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7141 using the graph browser tool;
  7142 
  7143 * Isabelle manuals now also available as PDF;
  7144 
  7145 * theory loader rewritten from scratch (may not be fully
  7146 bug-compatible); old loadpath variable has been replaced by show_path,
  7147 add_path, del_path, reset_path functions; new operations such as
  7148 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7149 isatool doc ref);
  7150 
  7151 * improved isatool install: option -k creates KDE application icon,
  7152 option -p DIR installs standalone binaries;
  7153 
  7154 * added ML_PLATFORM setting (useful for cross-platform installations);
  7155 more robust handling of platform specific ML images for SML/NJ;
  7156 
  7157 * the settings environment is now statically scoped, i.e. it is never
  7158 created again in sub-processes invoked from isabelle, isatool, or
  7159 Isabelle;
  7160 
  7161 * path element specification '~~' refers to '$ISABELLE_HOME';
  7162 
  7163 * in locales, the "assumes" and "defines" parts may be omitted if
  7164 empty;
  7165 
  7166 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7167 long arrows);
  7168 
  7169 * new print_mode "HTML";
  7170 
  7171 * new flag show_tags controls display of tags of theorems (which are
  7172 basically just comments that may be attached by some tools);
  7173 
  7174 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7175 mode and goal output format:
  7176 
  7177 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7178 244c244
  7179 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7180 ---
  7181 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7182 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7183 181c181
  7184 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7185 ---
  7186 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7187 
  7188 * function bind_thms stores lists of theorems (cf. bind_thm);
  7189 
  7190 * new shorthand tactics ftac, eatac, datac, fatac;
  7191 
  7192 * qed (and friends) now accept "" as result name; in that case the
  7193 theorem is not stored, but proper checks and presentation of the
  7194 result still apply;
  7195 
  7196 * theorem database now also indexes constants "Trueprop", "all",
  7197 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7198 
  7199 
  7200 *** HOL ***
  7201 
  7202 ** HOL arithmetic **
  7203 
  7204 * There are now decision procedures for linear arithmetic over nat and
  7205 int:
  7206 
  7207 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7208 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7209 are treated as atomic; subformulae not involving type `nat' or `int'
  7210 are ignored; quantified subformulae are ignored unless they are
  7211 positive universal or negative existential. The tactic has to be
  7212 invoked by hand and can be a little bit slow. In particular, the
  7213 running time is exponential in the number of occurrences of `min' and
  7214 `max', and `-' on `nat'.
  7215 
  7216 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7217 (negated) (in)equalities among the premises and the conclusion into
  7218 account (i.e. no compound formulae) and does not know about `min' and
  7219 `max', and `-' on `nat'. It is fast and is used automatically by the
  7220 simplifier.
  7221 
  7222 NB: At the moment, these decision procedures do not cope with mixed
  7223 nat/int formulae where the two parts interact, such as `m < n ==>
  7224 int(m) < int(n)'.
  7225 
  7226 * HOL/Numeral provides a generic theory of numerals (encoded
  7227 efficiently as bit strings); setup for types nat/int/real is in place;
  7228 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7229 int, existing theories and proof scripts may require a few additional
  7230 type constraints;
  7231 
  7232 * integer division and remainder can now be performed on constant
  7233 arguments;
  7234 
  7235 * many properties of integer multiplication, division and remainder
  7236 are now available;
  7237 
  7238 * An interface to the Stanford Validity Checker (SVC) is available through the
  7239 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7240 are proved automatically.  SVC must be installed separately, and its results
  7241 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7242 invocation of the underlying oracle).  For SVC see
  7243   http://verify.stanford.edu/SVC
  7244 
  7245 * IsaMakefile: the HOL-Real target now builds an actual image;
  7246 
  7247 
  7248 ** HOL misc **
  7249 
  7250 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7251 (in Isabelle/Isar) -- by Gertrud Bauer;
  7252 
  7253 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7254 analysis for assembly languages with subtypes;
  7255 
  7256 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7257 -- avoids syntactic ambiguities and treats state, transition, and
  7258 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7259 changed syntax and (many) tactics;
  7260 
  7261 * HOL/inductive: Now also handles more general introduction rules such
  7262   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7263   theorems are now maintained within the theory (maintained via the
  7264   "mono" attribute);
  7265 
  7266 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7267   (using function types) such as
  7268 
  7269   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7270 
  7271 * HOL/record: record_simproc (part of the default simpset) takes care
  7272 of selectors applied to updated records; record_split_tac is no longer
  7273 part of the default claset; update_defs may now be removed from the
  7274 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7275 
  7276   claset_ref () := claset() addSWrapper record_split_wrapper;
  7277   Delsimprocs [record_simproc]
  7278 
  7279 * HOL/typedef: fixed type inference for representing set; type
  7280 arguments now have to occur explicitly on the rhs as type constraints;
  7281 
  7282 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7283 names rather than an ML expression;
  7284 
  7285 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7286 supplied later.  Program schemes can be defined, such as
  7287     "While B C s = (if B s then While B C (C s) else s)"
  7288 where the well-founded relation can be chosen after B and C have been given.
  7289 
  7290 * HOL/List: the constructors of type list are now Nil and Cons;
  7291 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7292 course, ML tools referring to List.list.op # etc. have to be adapted;
  7293 
  7294 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7295 disabled by default; run isabelle with option -m HOL to get back to
  7296 the original Gordon/HOL-style output;
  7297 
  7298 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7299 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7300 
  7301 * HOL basic syntax simplified (more orthogonal): all variants of
  7302 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7303 Eps operator is provided as well: "SOME x. P[x]";
  7304 
  7305 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7306 
  7307 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7308 thus available for user theories;
  7309 
  7310 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7311 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7312 time;
  7313 
  7314 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7315 several times and then mp;
  7316 
  7317 
  7318 *** LK ***
  7319 
  7320 * the notation <<...>> is now available as a notation for sequences of
  7321 formulas;
  7322 
  7323 * the simplifier is now installed
  7324 
  7325 * the axiom system has been generalized (thanks to Soren Heilmann)
  7326 
  7327 * the classical reasoner now has a default rule database
  7328 
  7329 
  7330 *** ZF ***
  7331 
  7332 * new primrec section allows primitive recursive functions to be given
  7333 directly (as in HOL) over datatypes and the natural numbers;
  7334 
  7335 * new tactics induct_tac and exhaust_tac for induction (or case
  7336 analysis) over datatypes and the natural numbers;
  7337 
  7338 * the datatype declaration of type T now defines the recursor T_rec;
  7339 
  7340 * simplification automatically does freeness reasoning for datatype
  7341 constructors;
  7342 
  7343 * automatic type-inference, with AddTCs command to insert new
  7344 type-checking rules;
  7345 
  7346 * datatype introduction rules are now added as Safe Introduction rules
  7347 to the claset;
  7348 
  7349 * the syntax "if P then x else y" is now available in addition to
  7350 if(P,x,y);
  7351 
  7352 
  7353 *** Internal programming interfaces ***
  7354 
  7355 * tuned simplifier trace output; new flag debug_simp;
  7356 
  7357 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7358 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7359 
  7360 * AxClass.axclass_tac lost the theory argument;
  7361 
  7362 * tuned current_goals_markers semantics: begin / end goal avoids
  7363 printing empty lines;
  7364 
  7365 * removed prs and prs_fn hook, which was broken because it did not
  7366 include \n in its semantics, forcing writeln to add one
  7367 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7368 string -> unit if you really want to output text without newline;
  7369 
  7370 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7371 plain output, interface builders may have to enable 'isabelle_font'
  7372 mode to get Isabelle font glyphs as before;
  7373 
  7374 * refined token_translation interface; INCOMPATIBILITY: output length
  7375 now of type real instead of int;
  7376 
  7377 * theory loader actions may be traced via new ThyInfo.add_hook
  7378 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7379 your own database of information attached to *whole* theories -- as
  7380 opposed to intra-theory data slots offered via TheoryDataFun;
  7381 
  7382 * proper handling of dangling sort hypotheses (at last!);
  7383 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7384 extra sort hypotheses that can be witnessed from the type signature;
  7385 the force_strip_shyps flag is gone, any remaining shyps are simply
  7386 left in the theorem (with a warning issued by strip_shyps_warning);
  7387 
  7388 
  7389 
  7390 New in Isabelle98-1 (October 1998)
  7391 ----------------------------------
  7392 
  7393 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7394 
  7395 * several changes of automated proof tools;
  7396 
  7397 * HOL: major changes to the inductive and datatype packages, including
  7398 some minor incompatibilities of theory syntax;
  7399 
  7400 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7401 called `inj_on';
  7402 
  7403 * HOL: removed duplicate thms in Arith:
  7404   less_imp_add_less  should be replaced by  trans_less_add1
  7405   le_imp_add_le      should be replaced by  trans_le_add1
  7406 
  7407 * HOL: unary minus is now overloaded (new type constraints may be
  7408 required);
  7409 
  7410 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7411 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7412 now taken as an integer constant.
  7413 
  7414 * Pure: ML function 'theory_of' renamed to 'theory';
  7415 
  7416 
  7417 *** Proof tools ***
  7418 
  7419 * Simplifier:
  7420   1. Asm_full_simp_tac is now more aggressive.
  7421      1. It will sometimes reorient premises if that increases their power to
  7422         simplify.
  7423      2. It does no longer proceed strictly from left to right but may also
  7424         rotate premises to achieve further simplification.
  7425      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7426      old Asm_full_simp_tac in that it does not rotate premises.
  7427   2. The simplifier now knows a little bit about nat-arithmetic.
  7428 
  7429 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7430 allows for selected deletion of wrappers, by introduction of names for
  7431 wrapper functionals.  This implies that addbefore, addSbefore,
  7432 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7433 and that adding two tactics with the same name overwrites the first
  7434 one (emitting a warning).
  7435   type wrapper = (int -> tactic) -> (int -> tactic)
  7436   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7437   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7438   delWrapper, delSWrapper: claset *  string            -> claset
  7439   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7440 
  7441 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7442 semantics; addbefore now affects only the unsafe part of step_tac
  7443 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7444 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7445 by Force_tac;
  7446 
  7447 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7448 compWrapper; added safe wrapper (and access functions for it);
  7449 
  7450 * HOL/split_all_tac is now much faster and fails if there is nothing
  7451 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7452 and the names of the automatically generated variables have changed.
  7453 split_all_tac has moved within claset() from unsafe wrappers to safe
  7454 wrappers, which means that !!-bound variables are split much more
  7455 aggressively, and safe_tac and clarify_tac now split such variables.
  7456 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7457 Note: the same holds for record_split_tac, which does the job of
  7458 split_all_tac for record fields.
  7459 
  7460 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7461 permanently to the default simpset using Addsplits just like
  7462 Addsimps. They can be removed via Delsplits just like
  7463 Delsimps. Lower-case versions are also available.
  7464 
  7465 * HOL/Simplifier: The rule split_if is now part of the default
  7466 simpset. This means that the simplifier will eliminate all occurrences
  7467 of if-then-else in the conclusion of a goal. To prevent this, you can
  7468 either remove split_if completely from the default simpset by
  7469 `Delsplits [split_if]' or remove it in a specific call of the
  7470 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7471 other case splitting rules to/from the default simpset: every datatype
  7472 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7473 t is the name of the datatype).
  7474 
  7475 * Classical reasoner / Simplifier combination: new force_tac (and
  7476 derivatives Force_tac, force) combines rewriting and classical
  7477 reasoning (and whatever other tools) similarly to auto_tac, but is
  7478 aimed to solve the given subgoal completely.
  7479 
  7480 
  7481 *** General ***
  7482 
  7483 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7484 and `goalw': the theory is no longer needed as an explicit argument -
  7485 the current theory context is used; assumptions are no longer returned
  7486 at the ML-level unless one of them starts with ==> or !!; it is
  7487 recommended to convert to these new commands using isatool fixgoal
  7488 (backup your sources first!);
  7489 
  7490 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7491 the current theory context, and 'theory' to lookup stored theories;
  7492 
  7493 * new theory section 'locale' for declaring constants, assumptions and
  7494 definitions that have local scope;
  7495 
  7496 * new theory section 'nonterminals' for purely syntactic types;
  7497 
  7498 * new theory section 'setup' for generic ML setup functions
  7499 (e.g. package initialization);
  7500 
  7501 * the distribution now includes Isabelle icons: see
  7502 lib/logo/isabelle-{small,tiny}.xpm;
  7503 
  7504 * isatool install - install binaries with absolute references to
  7505 ISABELLE_HOME/bin;
  7506 
  7507 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7508 
  7509 * print mode 'emacs' reserved for Isamode;
  7510 
  7511 * support multiple print (ast) translations per constant name;
  7512 
  7513 * theorems involving oracles are now printed with a suffixed [!];
  7514 
  7515 
  7516 *** HOL ***
  7517 
  7518 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7519 
  7520 * HOL/inductive package reorganized and improved: now supports mutual
  7521 definitions such as
  7522 
  7523   inductive EVEN ODD
  7524     intrs
  7525       null "0 : EVEN"
  7526       oddI "n : EVEN ==> Suc n : ODD"
  7527       evenI "n : ODD ==> Suc n : EVEN"
  7528 
  7529 new theorem list "elims" contains an elimination rule for each of the
  7530 recursive sets; inductive definitions now handle disjunctive premises
  7531 correctly (also ZF);
  7532 
  7533 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7534 "mutual_induct" no longer exists - the induction rule is always
  7535 contained in "induct";
  7536 
  7537 
  7538 * HOL/datatype package re-implemented and greatly improved: now
  7539 supports mutually recursive datatypes such as
  7540 
  7541   datatype
  7542     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7543             | SUM ('a aexp) ('a aexp)
  7544             | DIFF ('a aexp) ('a aexp)
  7545             | NUM 'a
  7546   and
  7547     'a bexp = LESS ('a aexp) ('a aexp)
  7548             | AND ('a bexp) ('a bexp)
  7549             | OR ('a bexp) ('a bexp)
  7550 
  7551 as well as indirectly recursive datatypes such as
  7552 
  7553   datatype
  7554     ('a, 'b) term = Var 'a
  7555                   | App 'b ((('a, 'b) term) list)
  7556 
  7557 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7558 induction on mutually / indirectly recursive datatypes.
  7559 
  7560 Primrec equations are now stored in theory and can be accessed via
  7561 <function_name>.simps.
  7562 
  7563 INCOMPATIBILITIES:
  7564 
  7565   - Theories using datatypes must now have theory Datatype as an
  7566     ancestor.
  7567   - The specific <typename>.induct_tac no longer exists - use the
  7568     generic induct_tac instead.
  7569   - natE has been renamed to nat.exhaust - use exhaust_tac
  7570     instead of res_inst_tac ... natE. Note that the variable
  7571     names in nat.exhaust differ from the names in natE, this
  7572     may cause some "fragile" proofs to fail.
  7573   - The theorems split_<typename>_case and split_<typename>_case_asm
  7574     have been renamed to <typename>.split and <typename>.split_asm.
  7575   - Since default sorts of type variables are now handled correctly,
  7576     some datatype definitions may have to be annotated with explicit
  7577     sort constraints.
  7578   - Primrec definitions no longer require function name and type
  7579     of recursive argument.
  7580 
  7581 Consider using isatool fixdatatype to adapt your theories and proof
  7582 scripts to the new package (backup your sources first!).
  7583 
  7584 
  7585 * HOL/record package: considerably improved implementation; now
  7586 includes concrete syntax for record types, terms, updates; theorems
  7587 for surjective pairing and splitting !!-bound record variables; proof
  7588 support is as follows:
  7589 
  7590   1) standard conversions (selectors or updates applied to record
  7591 constructor terms) are part of the standard simpset;
  7592 
  7593   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7594 made part of standard simpset and claset via addIffs;
  7595 
  7596   3) a tactic for record field splitting (record_split_tac) is part of
  7597 the standard claset (addSWrapper);
  7598 
  7599 To get a better idea about these rules you may retrieve them via
  7600 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7601 the name of your record type.
  7602 
  7603 The split tactic 3) conceptually simplifies by the following rule:
  7604 
  7605   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7606 
  7607 Thus any record variable that is bound by meta-all will automatically
  7608 blow up into some record constructor term, consequently the
  7609 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7610 solve record problems automatically.
  7611 
  7612 
  7613 * reorganized the main HOL image: HOL/Integ and String loaded by
  7614 default; theory Main includes everything;
  7615 
  7616 * automatic simplification of integer sums and comparisons, using cancellation;
  7617 
  7618 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7619 
  7620 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7621 
  7622 * many new identities for unions, intersections, set difference, etc.;
  7623 
  7624 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7625 called split_if, split_split, split_sum_case and split_nat_case (to go
  7626 with add/delsplits);
  7627 
  7628 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7629 (?x::unit) = (); this is made part of the default simpset, which COULD
  7630 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7631 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7632 unit_abs_eta_conv is added in order to counter the effect of
  7633 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7634 %u.f();
  7635 
  7636 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7637 makes more sense);
  7638 
  7639 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7640   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7641   disjointness reasoning but breaking a few old proofs.
  7642 
  7643 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7644 to 'converse' from 'inverse' (for compatibility with ZF and some
  7645 literature);
  7646 
  7647 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7648 the well-founded relation;
  7649 
  7650 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7651     Compl A.  The "Compl" syntax remains available as input syntax for this
  7652     release ONLY.
  7653 
  7654 * HOL/Update: new theory of function updates:
  7655     f(a:=b) == %x. if x=a then b else f x
  7656 may also be iterated as in f(a:=b,c:=d,...);
  7657 
  7658 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7659 
  7660 * HOL/List:
  7661   - new function list_update written xs[i:=v] that updates the i-th
  7662     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7663   - new function `upt' written [i..j(] which generates the list
  7664     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7665     bound write [i..j], which is a shorthand for [i..j+1(].
  7666   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7667 
  7668 * HOL/Arith:
  7669   - removed 'pred' (predecessor) function;
  7670   - generalized some theorems about n-1;
  7671   - many new laws about "div" and "mod";
  7672   - new laws about greatest common divisors (see theory ex/Primes);
  7673 
  7674 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7675 instead of "inverse";
  7676 
  7677 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7678   of the multiset ordering;
  7679 
  7680 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7681   (not included by default);
  7682 
  7683 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7684 
  7685 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7686   programs, i.e. different program variables may have different types.
  7687 
  7688 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7689   [previously, this check worked only if the rewrite rule was unconditional]
  7690   Now rew can involve either definitions or equalities (either == or =).
  7691 
  7692 
  7693 *** ZF ***
  7694 
  7695 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7696   only the theorems proved on ZF.ML;
  7697 
  7698 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7699   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7700   disjointness reasoning but breaking a few old proofs.
  7701 
  7702 * ZF/Update: new theory of function updates
  7703     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7704   may also be iterated as in f(a:=b,c:=d,...);
  7705 
  7706 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7707 
  7708 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7709   [previously, this check worked only if the rewrite rule was unconditional]
  7710   Now rew can involve either definitions or equalities (either == or =).
  7711 
  7712 * case_tac provided for compatibility with HOL
  7713     (like the old excluded_middle_tac, but with subgoals swapped)
  7714 
  7715 
  7716 *** Internal programming interfaces ***
  7717 
  7718 * Pure: several new basic modules made available for general use, see
  7719 also src/Pure/README;
  7720 
  7721 * improved the theory data mechanism to support encapsulation (data
  7722 kind name replaced by private Object.kind, acting as authorization
  7723 key); new type-safe user interface via functor TheoryDataFun; generic
  7724 print_data function becomes basically useless;
  7725 
  7726 * removed global_names compatibility flag -- all theory declarations
  7727 are qualified by default;
  7728 
  7729 * module Pure/Syntax now offers quote / antiquote translation
  7730 functions (useful for Hoare logic etc. with implicit dependencies);
  7731 see HOL/ex/Antiquote for an example use;
  7732 
  7733 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7734 cterm -> thm;
  7735 
  7736 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7737 subgoal;
  7738 
  7739 * Display.print_goals function moved to Locale.print_goals;
  7740 
  7741 * standard print function for goals supports current_goals_markers
  7742 variable for marking begin of proof, end of proof, start of goal; the
  7743 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7744 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7745 for example;
  7746 
  7747 
  7748 
  7749 New in Isabelle98 (January 1998)
  7750 --------------------------------
  7751 
  7752 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7753 
  7754 * changed lexical syntax of terms / types: dots made part of long
  7755 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7756 
  7757 * simpset (and claset) reference variable replaced by functions
  7758 simpset / simpset_ref;
  7759 
  7760 * no longer supports theory aliases (via merge) and non-trivial
  7761 implicit merge of thms' signatures;
  7762 
  7763 * most internal names of constants changed due to qualified names;
  7764 
  7765 * changed Pure/Sequence interface (see Pure/seq.ML);
  7766 
  7767 
  7768 *** General Changes ***
  7769 
  7770 * hierachically structured name spaces (for consts, types, axms, thms
  7771 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7772 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7773 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7774 long_names for fully qualified output names; NOTE: ML programs
  7775 (special tactics, packages etc.) referring to internal names may have
  7776 to be adapted to cope with fully qualified names; in case of severe
  7777 backward campatibility problems try setting 'global_names' at compile
  7778 time to have enrything declared within a flat name space; one may also
  7779 fine tune name declarations in theories via the 'global' and 'local'
  7780 section;
  7781 
  7782 * reimplemented the implicit simpset and claset using the new anytype
  7783 data filed in signatures; references simpset:simpset ref etc. are
  7784 replaced by functions simpset:unit->simpset and
  7785 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7786 to patch your ML files accordingly;
  7787 
  7788 * HTML output now includes theory graph data for display with Java
  7789 applet or isatool browser; data generated automatically via isatool
  7790 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7791 
  7792 * defs may now be conditional; improved rewrite_goals_tac to handle
  7793 conditional equations;
  7794 
  7795 * defs now admits additional type arguments, using TYPE('a) syntax;
  7796 
  7797 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7798 creates a new theory node; implicit merge of thms' signatures is
  7799 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7800 transfer:theory->thm->thm in (rare) cases;
  7801 
  7802 * improved handling of draft signatures / theories; draft thms (and
  7803 ctyps, cterms) are automatically promoted to real ones;
  7804 
  7805 * slightly changed interfaces for oracles: admit many per theory, named
  7806 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7807 
  7808 * print_goals: optional output of const types (set show_consts and
  7809 show_types);
  7810 
  7811 * improved output of warnings (###) and errors (***);
  7812 
  7813 * subgoal_tac displays a warning if the new subgoal has type variables;
  7814 
  7815 * removed old README and Makefiles;
  7816 
  7817 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7818 
  7819 * removed obsolete init_pps and init_database;
  7820 
  7821 * deleted the obsolete tactical STATE, which was declared by
  7822     fun STATE tacfun st = tacfun st st;
  7823 
  7824 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7825 (which abbreviates $HOME);
  7826 
  7827 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7828 use isatool fixseq to adapt your ML programs (this works for fully
  7829 qualified references to the Sequence structure only!);
  7830 
  7831 * use_thy no longer requires writable current directory; it always
  7832 reloads .ML *and* .thy file, if either one is out of date;
  7833 
  7834 
  7835 *** Classical Reasoner ***
  7836 
  7837 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7838 tactics that use classical reasoning to simplify a subgoal without
  7839 splitting it into several subgoals;
  7840 
  7841 * Safe_tac: like safe_tac but uses the default claset;
  7842 
  7843 
  7844 *** Simplifier ***
  7845 
  7846 * added simplification meta rules:
  7847     (asm_)(full_)simplify: simpset -> thm -> thm;
  7848 
  7849 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7850 logics (again);
  7851 
  7852 * added prems argument to simplification procedures;
  7853 
  7854 * HOL, FOL, ZF: added infix function `addsplits':
  7855   instead of `<simpset> setloop (split_tac <thms>)'
  7856   you can simply write `<simpset> addsplits <thms>'
  7857 
  7858 
  7859 *** Syntax ***
  7860 
  7861 * TYPE('a) syntax for type reflection terms;
  7862 
  7863 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7864 
  7865 * pretty printer: changed order of mixfix annotation preference (again!);
  7866 
  7867 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7868 
  7869 
  7870 *** HOL ***
  7871 
  7872 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7873   with `addloop' of the simplifier to faciliate case splitting in premises.
  7874 
  7875 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7876 
  7877 * HOL/Auth: new protocol proofs including some for the Internet
  7878   protocol TLS;
  7879 
  7880 * HOL/Map: new theory of `maps' a la VDM;
  7881 
  7882 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7883 cancelling out common nat summands from =, <, <= (in)equalities, or
  7884 differences; simplification procedures nat_cancel_factor for
  7885 cancelling common factor from =, <, <= (in)equalities over natural
  7886 sums; nat_cancel contains both kinds of procedures, it is installed by
  7887 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7888 
  7889 * HOL/simplifier: terms of the form
  7890   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7891   are rewritten to
  7892   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7893   and those of the form
  7894   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7895   are rewritten to
  7896   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7897 
  7898 * HOL/datatype
  7899   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7900 
  7901   P(t_case f1 ... fn x) =
  7902      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7903         ...
  7904        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7905      )
  7906 
  7907   and a theorem `split_t_case_asm' of the form
  7908 
  7909   P(t_case f1 ... fn x) =
  7910     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7911         ...
  7912        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7913      )
  7914   which can be added to a simpset via `addsplits'. The existing theorems
  7915   expand_list_case and expand_option_case have been renamed to
  7916   split_list_case and split_option_case.
  7917 
  7918 * HOL/Arithmetic:
  7919   - `pred n' is automatically converted to `n-1'.
  7920     Users are strongly encouraged not to use `pred' any longer,
  7921     because it will disappear altogether at some point.
  7922   - Users are strongly encouraged to write "0 < n" rather than
  7923     "n ~= 0". Theorems and proof tools have been modified towards this
  7924     `standard'.
  7925 
  7926 * HOL/Lists:
  7927   the function "set_of_list" has been renamed "set" (and its theorems too);
  7928   the function "nth" now takes its arguments in the reverse order and
  7929   has acquired the infix notation "!" as in "xs!n".
  7930 
  7931 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7932 
  7933 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7934   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7935 
  7936 * HOL/record: extensible records with schematic structural subtyping
  7937 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7938 still lacks various theorems and concrete record syntax;
  7939 
  7940 
  7941 *** HOLCF ***
  7942 
  7943 * removed "axioms" and "generated by" sections;
  7944 
  7945 * replaced "ops" section by extended "consts" section, which is capable of
  7946   handling the continuous function space "->" directly;
  7947 
  7948 * domain package:
  7949   . proves theorems immediately and stores them in the theory,
  7950   . creates hierachical name space,
  7951   . now uses normal mixfix annotations (instead of cinfix...),
  7952   . minor changes to some names and values (for consistency),
  7953   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7954   . separator between mutual domain defs: changed "," to "and",
  7955   . improved handling of sort constraints;  now they have to
  7956     appear on the left-hand side of the equations only;
  7957 
  7958 * fixed LAM <x,y,zs>.b syntax;
  7959 
  7960 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7961 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7962 
  7963 
  7964 *** FOL and ZF ***
  7965 
  7966 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7967   with `addloop' of the simplifier to faciliate case splitting in premises.
  7968 
  7969 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7970 in HOL, they strip ALL and --> from proved theorems;
  7971 
  7972 
  7973 
  7974 New in Isabelle94-8 (May 1997)
  7975 ------------------------------
  7976 
  7977 *** General Changes ***
  7978 
  7979 * new utilities to build / run / maintain Isabelle etc. (in parts
  7980 still somewhat experimental); old Makefiles etc. still functional;
  7981 
  7982 * new 'Isabelle System Manual';
  7983 
  7984 * INSTALL text, together with ./configure and ./build scripts;
  7985 
  7986 * reimplemented type inference for greater efficiency, better error
  7987 messages and clean internal interface;
  7988 
  7989 * prlim command for dealing with lots of subgoals (an easier way of
  7990 setting goals_limit);
  7991 
  7992 
  7993 *** Syntax ***
  7994 
  7995 * supports alternative (named) syntax tables (parser and pretty
  7996 printer); internal interface is provided by add_modesyntax(_i);
  7997 
  7998 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7999 be used in conjunction with the Isabelle symbol font; uses the
  8000 "symbols" syntax table;
  8001 
  8002 * added token_translation interface (may translate name tokens in
  8003 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8004 the current print_mode); IMPORTANT: user print translation functions
  8005 are responsible for marking newly introduced bounds
  8006 (Syntax.mark_boundT);
  8007 
  8008 * token translations for modes "xterm" and "xterm_color" that display
  8009 names in bold, underline etc. or colors (which requires a color
  8010 version of xterm);
  8011 
  8012 * infixes may now be declared with names independent of their syntax;
  8013 
  8014 * added typed_print_translation (like print_translation, but may
  8015 access type of constant);
  8016 
  8017 
  8018 *** Classical Reasoner ***
  8019 
  8020 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8021 some limitations.  Blast_tac...
  8022   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8023   + ignores elimination rules that don't have the correct format
  8024         (the conclusion MUST be a formula variable)
  8025   + ignores types, which can make HOL proofs fail
  8026   + rules must not require higher-order unification, e.g. apply_type in ZF
  8027     [message "Function Var's argument not a bound variable" relates to this]
  8028   + its proof strategy is more general but can actually be slower
  8029 
  8030 * substitution with equality assumptions no longer permutes other
  8031 assumptions;
  8032 
  8033 * minor changes in semantics of addafter (now called addaltern); renamed
  8034 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8035 (and access functions for it);
  8036 
  8037 * improved combination of classical reasoner and simplifier:
  8038   + functions for handling clasimpsets
  8039   + improvement of addss: now the simplifier is called _after_ the
  8040     safe steps.
  8041   + safe variant of addss called addSss: uses safe simplifications
  8042     _during_ the safe steps. It is more complete as it allows multiple
  8043     instantiations of unknowns (e.g. with slow_tac).
  8044 
  8045 *** Simplifier ***
  8046 
  8047 * added interface for simplification procedures (functions that
  8048 produce *proven* rewrite rules on the fly, depending on current
  8049 redex);
  8050 
  8051 * ordering on terms as parameter (used for ordered rewriting);
  8052 
  8053 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8054 
  8055 * the solver is now split into a safe and an unsafe part.
  8056 This should be invisible for the normal user, except that the
  8057 functions setsolver and addsolver have been renamed to setSolver and
  8058 addSolver; added safe_asm_full_simp_tac;
  8059 
  8060 
  8061 *** HOL ***
  8062 
  8063 * a generic induction tactic `induct_tac' which works for all datatypes and
  8064 also for type `nat';
  8065 
  8066 * a generic case distinction tactic `exhaust_tac' which works for all
  8067 datatypes and also for type `nat';
  8068 
  8069 * each datatype comes with a function `size';
  8070 
  8071 * patterns in case expressions allow tuple patterns as arguments to
  8072 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8073 
  8074 * primrec now also works with type nat;
  8075 
  8076 * recdef: a new declaration form, allows general recursive functions to be
  8077 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8078 
  8079 * the constant for negation has been renamed from "not" to "Not" to
  8080 harmonize with FOL, ZF, LK, etc.;
  8081 
  8082 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8083 infinite lists;
  8084 
  8085 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8086 
  8087 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8088 problems in commutative rings, using axiomatic type classes for + and *;
  8089 
  8090 * more examples in HOL/MiniML and HOL/Auth;
  8091 
  8092 * more default rewrite rules for quantifiers, union/intersection;
  8093 
  8094 * a new constant `arbitrary == @x.False';
  8095 
  8096 * HOLCF/IOA replaces old HOL/IOA;
  8097 
  8098 * HOLCF changes: derived all rules and arities
  8099   + axiomatic type classes instead of classes
  8100   + typedef instead of faking type definitions
  8101   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  8102   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  8103   + eliminated the types void, one, tr
  8104   + use unit lift and bool lift (with translations) instead of one and tr
  8105   + eliminated blift from Lift3.thy (use Def instead of blift)
  8106   all eliminated rules are derived as theorems --> no visible changes ;
  8107 
  8108 
  8109 *** ZF ***
  8110 
  8111 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8112 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8113 as ZF_cs addSIs [equalityI];
  8114 
  8115 
  8116 
  8117 New in Isabelle94-7 (November 96)
  8118 ---------------------------------
  8119 
  8120 * allowing negative levels (as offsets) in prlev and choplev;
  8121 
  8122 * super-linear speedup for large simplifications;
  8123 
  8124 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8125 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8126 FAIL); can suppress it using the command Delsimps (ex_simps @
  8127 all_simps); De Morgan laws are also now included, by default;
  8128 
  8129 * improved printing of ==>  :  ~:
  8130 
  8131 * new object-logic "Sequents" adds linear logic, while replacing LK
  8132 and Modal (thanks to Sara Kalvala);
  8133 
  8134 * HOL/Auth: correctness proofs for authentication protocols;
  8135 
  8136 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8137 examples on HOL/Auth);
  8138 
  8139 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8140 the rewriter and classical reasoner simultaneously;
  8141 
  8142 * function uresult no longer returns theorems in "standard" format;
  8143 regain previous version by: val uresult = standard o uresult;
  8144 
  8145 
  8146 
  8147 New in Isabelle94-6
  8148 -------------------
  8149 
  8150 * oracles -- these establish an interface between Isabelle and trusted
  8151 external reasoners, which may deliver results as theorems;
  8152 
  8153 * proof objects (in particular record all uses of oracles);
  8154 
  8155 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8156 
  8157 * "constdefs" section in theory files;
  8158 
  8159 * "primrec" section (HOL) no longer requires names;
  8160 
  8161 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8162 
  8163 
  8164 
  8165 New in Isabelle94-5
  8166 -------------------
  8167 
  8168 * reduced space requirements;
  8169 
  8170 * automatic HTML generation from theories;
  8171 
  8172 * theory files no longer require "..." (quotes) around most types;
  8173 
  8174 * new examples, including two proofs of the Church-Rosser theorem;
  8175 
  8176 * non-curried (1994) version of HOL is no longer distributed;
  8177 
  8178 
  8179 
  8180 New in Isabelle94-4
  8181 -------------------
  8182 
  8183 * greatly reduced space requirements;
  8184 
  8185 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8186 
  8187 * searchable theorem database (see the section "Retrieving theorems" on
  8188 page 8 of the Reference Manual);
  8189 
  8190 * new examples, including Grabczewski's monumental case study of the
  8191 Axiom of Choice;
  8192 
  8193 * The previous version of HOL renamed to Old_HOL;
  8194 
  8195 * The new version of HOL (previously called CHOL) uses a curried syntax
  8196 for functions.  Application looks like f a b instead of f(a,b);
  8197 
  8198 * Mutually recursive inductive definitions finally work in HOL;
  8199 
  8200 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8201 translates to the operator "split";
  8202 
  8203 
  8204 
  8205 New in Isabelle94-3
  8206 -------------------
  8207 
  8208 * new infix operator, addss, allowing the classical reasoner to
  8209 perform simplification at each step of its search.  Example:
  8210         fast_tac (cs addss ss)
  8211 
  8212 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8213 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8214 look like (a,b) instead of <a,b>;
  8215 
  8216 * PLEASE NOTE: CHOL will eventually replace HOL!
  8217 
  8218 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8219 It translates to the operator "split".  A new theory of integers is available;
  8220 
  8221 * In ZF, integer numerals now denote two's-complement binary integers.
  8222 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8223 
  8224 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8225 of the Axiom of Choice;
  8226 
  8227 
  8228 
  8229 New in Isabelle94-2
  8230 -------------------
  8231 
  8232 * Significantly faster resolution;
  8233 
  8234 * the different sections in a .thy file can now be mixed and repeated
  8235 freely;
  8236 
  8237 * Database of theorems for FOL, HOL and ZF.  New
  8238 commands including qed, qed_goal and bind_thm store theorems in the database.
  8239 
  8240 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8241 a given theory (thms_of), or find out what theory a theorem was proved in
  8242 (theory_of_thm);
  8243 
  8244 * Bugs fixed in the inductive definition and datatype packages;
  8245 
  8246 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8247 and HOL_dup_cs obsolete;
  8248 
  8249 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8250 have been removed;
  8251 
  8252 * Simpler definition of function space in ZF;
  8253 
  8254 * new results about cardinal and ordinal arithmetic in ZF;
  8255 
  8256 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8257 types;
  8258 
  8259 :mode=text:wrap=hard:maxLineLen=72: