NEWS
author wenzelm
Thu, 07 Jul 2011 23:55:15 +0200
changeset 44572 91c4d7397f0e
parent 44494 ecd4bb7a8bc0
child 44580 717e96cf9527
permissions -rw-r--r--
simplified make_option/dest_option;
added make_variant/dest_variant -- usual representation of datatypes;
     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 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   127 isar-ref manual.
   128 
   129 * Antiquotation @{value} evaluates the given term and presents its result.
   130 
   131 * Localized \isabellestyle switch can be used within blocks or groups
   132 like this:
   133 
   134   \isabellestyle{it}  %preferred default
   135   {\isabellestylett @{text "typewriter stuff"}}
   136 
   137 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   138 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   139 
   140 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   141 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   142 
   143 
   144 *** ML ***
   145 
   146 * Antiquotations for ML and document preparation are managed as theory
   147 data, which requires explicit setup.
   148 
   149 * Isabelle_Process.is_active allows tools to check if the official
   150 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   151 (better known as Proof General).
   152 
   153 * Structure Proof_Context follows standard naming scheme.  Old
   154 ProofContext is still available for some time as legacy alias.
   155 
   156 * Structure Timing provides various operations for timing; supersedes
   157 former start_timing/end_timing etc.
   158 
   159 * Path.print is the official way to show file-system paths to users
   160 (including quotes etc.).
   161 
   162 * Inner syntax: identifiers in parse trees of generic categories
   163 "logic", "aprop", "idt" etc. carry position information (disguised as
   164 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   165 translations that choke on unexpected type constraints.  Positions can
   166 be stripped in ML translations via Syntax.strip_positions /
   167 Syntax.strip_positions_ast, or via the syntax constant
   168 "_strip_positions" within parse trees.  As last resort, positions can
   169 be disabled via the configuration option Syntax.positions, which is
   170 called "syntax_positions" in Isar attribute syntax.
   171 
   172 * Discontinued special status of various ML structures that contribute
   173 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   174 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   175 refer directly to Ast.Constant, Lexicon.is_identifier,
   176 Syntax_Trans.mk_binder_tr etc.
   177 
   178 * Typed print translation: discontinued show_sorts argument, which is
   179 already available via context of "advanced" translation.
   180 
   181 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   182 goal states; body tactic needs to address all subgoals uniformly.
   183 
   184 * Slightly more special eq_list/eq_set, with shortcut involving
   185 pointer equality (assumes that eq relation is reflexive).
   186 
   187 * Classical tactics use proper Proof.context instead of historic types
   188 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   189 operate directly on Proof.context.  Raw type claset retains its use as
   190 snapshot of the classical context, which can be recovered via
   191 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   192 INCOMPATIBILITY, classical tactics and derived proof methods require
   193 proper Proof.context.
   194 
   195 
   196 
   197 New in Isabelle2011 (January 2011)
   198 ----------------------------------
   199 
   200 *** General ***
   201 
   202 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   203 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   204 useful tooltips and hyperlinks produced from its static analysis.  The
   205 bundled component provides an executable Isabelle tool that can be run
   206 like this:
   207 
   208   Isabelle2011/bin/isabelle jedit
   209 
   210 * Significantly improved Isabelle/Isar implementation manual.
   211 
   212 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   213 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   214 while the default heap location within that directory lacks that extra
   215 suffix.  This isolates multiple Isabelle installations from each
   216 other, avoiding problems with old settings in new versions.
   217 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   218 
   219 * Source files are always encoded as UTF-8, instead of old-fashioned
   220 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   221 the following package declarations:
   222 
   223   \usepackage[utf8]{inputenc}
   224   \usepackage{textcomp}
   225 
   226 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   227 a Unicode character is treated as a single symbol, not a sequence of
   228 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   229 contain symbols without further backslash escapes, Unicode can now be
   230 used here as well.  Recall that Symbol.explode in ML provides a
   231 consistent view on symbols, while raw explode (or String.explode)
   232 merely give a byte-oriented representation.
   233 
   234 * Theory loader: source files are primarily located via the master
   235 directory of each theory node (where the .thy file itself resides).
   236 The global load path is still partially available as legacy feature.
   237 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   238 explicit paths, relatively to the theory.
   239 
   240 * Special treatment of ML file names has been discontinued.
   241 Historically, optional extensions .ML or .sml were added on demand --
   242 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   243 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   244 
   245 * Various options that affect pretty printing etc. are now properly
   246 handled within the context via configuration options, instead of
   247 unsynchronized references or print modes.  There are both ML Config.T
   248 entities and Isar declaration attributes to access these.
   249 
   250   ML (Config.T)                 Isar (attribute)
   251 
   252   eta_contract                  eta_contract
   253   show_brackets                 show_brackets
   254   show_sorts                    show_sorts
   255   show_types                    show_types
   256   show_question_marks           show_question_marks
   257   show_consts                   show_consts
   258   show_abbrevs                  show_abbrevs
   259 
   260   Syntax.ast_trace              syntax_ast_trace
   261   Syntax.ast_stat               syntax_ast_stat
   262   Syntax.ambiguity_level        syntax_ambiguity_level
   263 
   264   Goal_Display.goals_limit      goals_limit
   265   Goal_Display.show_main_goal   show_main_goal
   266 
   267   Method.rule_trace             rule_trace
   268 
   269   Thy_Output.display            thy_output_display
   270   Thy_Output.quotes             thy_output_quotes
   271   Thy_Output.indent             thy_output_indent
   272   Thy_Output.source             thy_output_source
   273   Thy_Output.break              thy_output_break
   274 
   275 Note that corresponding "..._default" references in ML may only be
   276 changed globally at the ROOT session setup, but *not* within a theory.
   277 The option "show_abbrevs" supersedes the former print mode
   278 "no_abbrevs" with inverted meaning.
   279 
   280 * More systematic naming of some configuration options.
   281 INCOMPATIBILITY.
   282 
   283   trace_simp  ~>  simp_trace
   284   debug_simp  ~>  simp_debug
   285 
   286 * Support for real valued configuration options, using simplistic
   287 floating-point notation that coincides with the inner syntax for
   288 float_token.
   289 
   290 * Support for real valued preferences (with approximative PGIP type):
   291 front-ends need to accept "pgint" values in float notation.
   292 INCOMPATIBILITY.
   293 
   294 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   295 DejaVu Sans.
   296 
   297 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   298 
   299 
   300 *** Pure ***
   301 
   302 * Command 'type_synonym' (with single argument) replaces somewhat
   303 outdated 'types', which is still available as legacy feature for some
   304 time.
   305 
   306 * Command 'nonterminal' (with 'and' separated list of arguments)
   307 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   308 
   309 * Command 'notepad' replaces former 'example_proof' for
   310 experimentation in Isar without any result.  INCOMPATIBILITY.
   311 
   312 * Locale interpretation commands 'interpret' and 'sublocale' accept
   313 lists of equations to map definitions in a locale to appropriate
   314 entities in the context of the interpretation.  The 'interpretation'
   315 command already provided this functionality.
   316 
   317 * Diagnostic command 'print_dependencies' prints the locale instances
   318 that would be activated if the specified expression was interpreted in
   319 the current context.  Variant "print_dependencies!" assumes a context
   320 without interpretations.
   321 
   322 * Diagnostic command 'print_interps' prints interpretations in proofs
   323 in addition to interpretations in theories.
   324 
   325 * Discontinued obsolete 'global' and 'local' commands to manipulate
   326 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   327 Sign.root_path and Sign.local_path may be applied directly where this
   328 feature is still required for historical reasons.
   329 
   330 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   331 'definition' instead.
   332 
   333 * The "prems" fact, which refers to the accidental collection of
   334 foundational premises in the context, is now explicitly marked as
   335 legacy feature and will be discontinued soon.  Consider using "assms"
   336 of the head statement or reference facts by explicit names.
   337 
   338 * Document antiquotations @{class} and @{type} print classes and type
   339 constructors.
   340 
   341 * Document antiquotation @{file} checks file/directory entries within
   342 the local file system.
   343 
   344 
   345 *** HOL ***
   346 
   347 * Coercive subtyping: functions can be declared as coercions and type
   348 inference will add them as necessary upon input of a term.  Theory
   349 Complex_Main declares real :: nat => real and real :: int => real as
   350 coercions. A coercion function f is declared like this:
   351 
   352   declare [[coercion f]]
   353 
   354 To lift coercions through type constructors (e.g. from nat => real to
   355 nat list => real list), map functions can be declared, e.g.
   356 
   357   declare [[coercion_map map]]
   358 
   359 Currently coercion inference is activated only in theories including
   360 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   361 the configuration option "coercion_enabled", e.g. it can be enabled in
   362 other theories like this:
   363 
   364   declare [[coercion_enabled]]
   365 
   366 * Command 'partial_function' provides basic support for recursive
   367 function definitions over complete partial orders.  Concrete instances
   368 are provided for i) the option type, ii) tail recursion on arbitrary
   369 types, and iii) the heap monad of Imperative_HOL.  See
   370 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   371 for examples.
   372 
   373 * Function package: f.psimps rules are no longer implicitly declared
   374 as [simp].  INCOMPATIBILITY.
   375 
   376 * Datatype package: theorems generated for executable equality (class
   377 "eq") carry proper names and are treated as default code equations.
   378 
   379 * Inductive package: now offers command 'inductive_simps' to
   380 automatically derive instantiated and simplified equations for
   381 inductive predicates, similar to 'inductive_cases'.
   382 
   383 * Command 'enriched_type' allows to register properties of the
   384 functorial structure of types.
   385 
   386 * Improved infrastructure for term evaluation using code generator
   387 techniques, in particular static evaluation conversions.
   388 
   389 * Code generator: Scala (2.8 or higher) has been added to the target
   390 languages.
   391 
   392 * Code generator: globbing constant expressions "*" and "Theory.*"
   393 have been replaced by the more idiomatic "_" and "Theory._".
   394 INCOMPATIBILITY.
   395 
   396 * Code generator: export_code without explicit file declaration prints
   397 to standard output.  INCOMPATIBILITY.
   398 
   399 * Code generator: do not print function definitions for case
   400 combinators any longer.
   401 
   402 * Code generator: simplification with rules determined with
   403 src/Tools/Code/code_simp.ML and method "code_simp".
   404 
   405 * Code generator for records: more idiomatic representation of record
   406 types.  Warning: records are not covered by ancient SML code
   407 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   408 rep_datatype declaration helps to succeed then:
   409 
   410   record 'a foo = ...
   411   ...
   412   rep_datatype foo_ext ...
   413 
   414 * Records: logical foundation type for records does not carry a
   415 '_type' suffix any longer (obsolete due to authentic syntax).
   416 INCOMPATIBILITY.
   417 
   418 * Quickcheck now by default uses exhaustive testing instead of random
   419 testing.  Random testing can be invoked by "quickcheck [random]",
   420 exhaustive testing by "quickcheck [exhaustive]".
   421 
   422 * Quickcheck instantiates polymorphic types with small finite
   423 datatypes by default. This enables a simple execution mechanism to
   424 handle quantifiers and function equality over the finite datatypes.
   425 
   426 * Quickcheck random generator has been renamed from "code" to
   427 "random".  INCOMPATIBILITY.
   428 
   429 * Quickcheck now has a configurable time limit which is set to 30
   430 seconds by default. This can be changed by adding [timeout = n] to the
   431 quickcheck command. The time limit for Auto Quickcheck is still set
   432 independently.
   433 
   434 * Quickcheck in locales considers interpretations of that locale for
   435 counter example search.
   436 
   437 * Sledgehammer:
   438   - Added "smt" and "remote_smt" provers based on the "smt" proof
   439     method. See the Sledgehammer manual for details ("isabelle doc
   440     sledgehammer").
   441   - Renamed commands:
   442     sledgehammer atp_info ~> sledgehammer running_provers
   443     sledgehammer atp_kill ~> sledgehammer kill_provers
   444     sledgehammer available_atps ~> sledgehammer available_provers
   445     INCOMPATIBILITY.
   446   - Renamed options:
   447     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   448     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   449     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   450     (and "ms" and "min" are no longer supported)
   451     INCOMPATIBILITY.
   452 
   453 * Nitpick:
   454   - Renamed options:
   455     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   456     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   457     INCOMPATIBILITY.
   458   - Added support for partial quotient types.
   459   - Added local versions of the "Nitpick.register_xxx" functions.
   460   - Added "whack" option.
   461   - Allow registration of quotient types as codatatypes.
   462   - Improved "merge_type_vars" option to merge more types.
   463   - Removed unsound "fast_descrs" option.
   464   - Added custom symmetry breaking for datatypes, making it possible to reach
   465     higher cardinalities.
   466   - Prevent the expansion of too large definitions.
   467 
   468 * Proof methods "metis" and "meson" now have configuration options
   469 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   470 to diagnose these tools. E.g.
   471 
   472     using [[metis_trace = true]]
   473 
   474 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   475 manually as command 'solve_direct'.
   476 
   477 * The default SMT solver Z3 must be enabled explicitly (due to
   478 licensing issues) by setting the environment variable
   479 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   480 commercial applications, the SMT solver CVC3 is provided as fall-back;
   481 changing the SMT solver is done via the configuration option
   482 "smt_solver".
   483 
   484 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   485 i.e. "remote_cvc3" and "remote_z3".
   486 
   487 * Added basic SMT support for datatypes, records, and typedefs using
   488 the oracle mode (no proofs).  Direct support of pairs has been dropped
   489 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   490 support for a similar behavior).  Minor INCOMPATIBILITY.
   491 
   492 * Changed SMT configuration options:
   493   - Renamed:
   494     z3_proofs ~> smt_oracle (with inverted meaning)
   495     z3_trace_assms ~> smt_trace_used_facts
   496     INCOMPATIBILITY.
   497   - Added:
   498     smt_verbose
   499     smt_random_seed
   500     smt_datatypes
   501     smt_infer_triggers
   502     smt_monomorph_limit
   503     cvc3_options
   504     remote_cvc3_options
   505     remote_z3_options
   506     yices_options
   507 
   508 * Boogie output files (.b2i files) need to be declared in the theory
   509 header.
   510 
   511 * Simplification procedure "list_to_set_comprehension" rewrites list
   512 comprehensions applied to List.set to set comprehensions.  Occasional
   513 INCOMPATIBILITY, may be deactivated like this:
   514 
   515   declare [[simproc del: list_to_set_comprehension]]
   516 
   517 * Removed old version of primrec package.  INCOMPATIBILITY.
   518 
   519 * Removed simplifier congruence rule of "prod_case", as has for long
   520 been the case with "split".  INCOMPATIBILITY.
   521 
   522 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   523 
   524 * Removed [split_format ... and ... and ...] version of
   525 [split_format].  Potential INCOMPATIBILITY.
   526 
   527 * Predicate "sorted" now defined inductively, with nice induction
   528 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   529 
   530 * Constant "contents" renamed to "the_elem", to free the generic name
   531 contents for other uses.  INCOMPATIBILITY.
   532 
   533 * Renamed class eq and constant eq (for code generation) to class
   534 equal and constant equal, plus renaming of related facts and various
   535 tuning.  INCOMPATIBILITY.
   536 
   537 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   538 
   539 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   540 INCOMPATIBILITY.
   541 
   542 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   543 avoid confusion with finite sets.  INCOMPATIBILITY.
   544 
   545 * Abandoned locales equiv, congruent and congruent2 for equivalence
   546 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   547 for congruent(2)).
   548 
   549 * Some previously unqualified names have been qualified:
   550 
   551   types
   552     bool ~> HOL.bool
   553     nat ~> Nat.nat
   554 
   555   constants
   556     Trueprop ~> HOL.Trueprop
   557     True ~> HOL.True
   558     False ~> HOL.False
   559     op & ~> HOL.conj
   560     op | ~> HOL.disj
   561     op --> ~> HOL.implies
   562     op = ~> HOL.eq
   563     Not ~> HOL.Not
   564     The ~> HOL.The
   565     All ~> HOL.All
   566     Ex ~> HOL.Ex
   567     Ex1 ~> HOL.Ex1
   568     Let ~> HOL.Let
   569     If ~> HOL.If
   570     Ball ~> Set.Ball
   571     Bex ~> Set.Bex
   572     Suc ~> Nat.Suc
   573     Pair ~> Product_Type.Pair
   574     fst ~> Product_Type.fst
   575     snd ~> Product_Type.snd
   576     curry ~> Product_Type.curry
   577     op : ~> Set.member
   578     Collect ~> Set.Collect
   579 
   580 INCOMPATIBILITY.
   581 
   582 * More canonical naming convention for some fundamental definitions:
   583 
   584     bot_bool_eq ~> bot_bool_def
   585     top_bool_eq ~> top_bool_def
   586     inf_bool_eq ~> inf_bool_def
   587     sup_bool_eq ~> sup_bool_def
   588     bot_fun_eq  ~> bot_fun_def
   589     top_fun_eq  ~> top_fun_def
   590     inf_fun_eq  ~> inf_fun_def
   591     sup_fun_eq  ~> sup_fun_def
   592 
   593 INCOMPATIBILITY.
   594 
   595 * More stylized fact names:
   596 
   597   expand_fun_eq ~> fun_eq_iff
   598   expand_set_eq ~> set_eq_iff
   599   set_ext       ~> set_eqI
   600   nat_number    ~> eval_nat_numeral
   601 
   602 INCOMPATIBILITY.
   603 
   604 * Refactoring of code-generation specific operations in theory List:
   605 
   606   constants
   607     null ~> List.null
   608 
   609   facts
   610     mem_iff ~> member_def
   611     null_empty ~> null_def
   612 
   613 INCOMPATIBILITY.  Note that these were not supposed to be used
   614 regularly unless for striking reasons; their main purpose was code
   615 generation.
   616 
   617 Various operations from the Haskell prelude are used for generating
   618 Haskell code.
   619 
   620 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   621 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   622 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   623 
   624 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   625 "*" and "+" respectively.  INCOMPATIBILITY.
   626 
   627 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   628 "Sum_Type.Plus" instead.
   629 
   630 * Constant "split" has been merged with constant "prod_case"; names of
   631 ML functions, facts etc. involving split have been retained so far,
   632 though.  INCOMPATIBILITY.
   633 
   634 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   635 instead.  INCOMPATIBILITY.
   636 
   637 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   638 INCOMPATIBILITY.
   639 
   640 * Former theory Library/Enum is now part of the HOL-Main image.
   641 INCOMPATIBILITY: all constants of the Enum theory now have to be
   642 referred to by its qualified name.
   643 
   644   enum    ~>  Enum.enum
   645   nlists  ~>  Enum.nlists
   646   product ~>  Enum.product
   647 
   648 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   649 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   650 INCOMPATIBILITY.
   651 
   652 * Theory Library/SetsAndFunctions has been split into
   653 Library/Function_Algebras and Library/Set_Algebras; canonical names
   654 for instance definitions for functions; various improvements.
   655 INCOMPATIBILITY.
   656 
   657 * Theory Library/Multiset provides stable quicksort implementation of
   658 sort_key.
   659 
   660 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   661 INCOMPATIBILITY.
   662 
   663 * Session Multivariate_Analysis: introduced a type class for euclidean
   664 space.  Most theorems are now stated in terms of euclidean spaces
   665 instead of finite cartesian products.
   666 
   667   types
   668     real ^ 'n ~>  'a::real_vector
   669               ~>  'a::euclidean_space
   670               ~>  'a::ordered_euclidean_space
   671         (depends on your needs)
   672 
   673   constants
   674      _ $ _        ~> _ $$ _
   675      \<chi> x. _  ~> \<chi>\<chi> x. _
   676      CARD('n)     ~> DIM('a)
   677 
   678 Also note that the indices are now natural numbers and not from some
   679 finite type. Finite cartesian products of euclidean spaces, products
   680 of euclidean spaces the real and complex numbers are instantiated to
   681 be euclidean_spaces.  INCOMPATIBILITY.
   682 
   683 * Session Probability: introduced pextreal as positive extended real
   684 numbers.  Use pextreal as value for measures.  Introduce the
   685 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   686 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   687 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   688 
   689 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   690 INCOMPATIBILITY.
   691 
   692 * Session SPARK (with image HOL-SPARK) provides commands to load and
   693 prove verification conditions generated by the SPARK Ada program
   694 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   695 
   696 
   697 *** HOL-Algebra ***
   698 
   699 * Theorems for additive ring operations (locale abelian_monoid and
   700 descendants) are generated by interpretation from their multiplicative
   701 counterparts.  Names (in particular theorem names) have the mandatory
   702 qualifier 'add'.  Previous theorem names are redeclared for
   703 compatibility.
   704 
   705 * Structure "int_ring" is now an abbreviation (previously a
   706 definition).  This fits more natural with advanced interpretations.
   707 
   708 
   709 *** HOLCF ***
   710 
   711 * The domain package now runs in definitional mode by default: The
   712 former command 'new_domain' is now called 'domain'.  To use the domain
   713 package in its original axiomatic mode, use 'domain (unsafe)'.
   714 INCOMPATIBILITY.
   715 
   716 * The new class "domain" is now the default sort.  Class "predomain"
   717 is an unpointed version of "domain". Theories can be updated by
   718 replacing sort annotations as shown below.  INCOMPATIBILITY.
   719 
   720   'a::type ~> 'a::countable
   721   'a::cpo  ~> 'a::predomain
   722   'a::pcpo ~> 'a::domain
   723 
   724 * The old type class "rep" has been superseded by class "domain".
   725 Accordingly, users of the definitional package must remove any
   726 "default_sort rep" declarations.  INCOMPATIBILITY.
   727 
   728 * The domain package (definitional mode) now supports unpointed
   729 predomain argument types, as long as they are marked 'lazy'. (Strict
   730 arguments must be in class "domain".) For example, the following
   731 domain definition now works:
   732 
   733   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   734 
   735 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   736 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   737 'a option, and 'a list.  Additionally, it configures fixrec and the
   738 domain package to work with these types.  For example:
   739 
   740   fixrec isInl :: "('a + 'b) u -> tr"
   741     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   742 
   743   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   744 
   745 * The "(permissive)" option of fixrec has been replaced with a
   746 per-equation "(unchecked)" option. See
   747 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   748 
   749 * The "bifinite" class no longer fixes a constant "approx"; the class
   750 now just asserts that such a function exists.  INCOMPATIBILITY.
   751 
   752 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   753 defines an embedding of type 'a defl into udom by default; instances
   754 of "bifinite" and "domain" classes are available in
   755 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   756 
   757 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   758 
   759 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   760 
   761 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   762 
   763 * The function "cprod_map" has been renamed to "prod_map".
   764 INCOMPATIBILITY.
   765 
   766 * The monadic bind operator on each powerdomain has new binder syntax
   767 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   768 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   769 
   770 * The infix syntax for binary union on each powerdomain has changed
   771 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   772 syntax.  INCOMPATIBILITY.
   773 
   774 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   775 still supported as an input translation.
   776 
   777 * Renamed some theorems (the original names are also still available).
   778 
   779   expand_fun_below   ~> fun_below_iff
   780   below_fun_ext      ~> fun_belowI
   781   expand_cfun_eq     ~> cfun_eq_iff
   782   ext_cfun           ~> cfun_eqI
   783   expand_cfun_below  ~> cfun_below_iff
   784   below_cfun_ext     ~> cfun_belowI
   785   cont2cont_Rep_CFun ~> cont2cont_APP
   786 
   787 * The Abs and Rep functions for various types have changed names.
   788 Related theorem names have also changed to match. INCOMPATIBILITY.
   789 
   790   Rep_CFun  ~> Rep_cfun
   791   Abs_CFun  ~> Abs_cfun
   792   Rep_Sprod ~> Rep_sprod
   793   Abs_Sprod ~> Abs_sprod
   794   Rep_Ssum  ~> Rep_ssum
   795   Abs_Ssum  ~> Abs_ssum
   796 
   797 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   798 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   799 
   800 * Various changes to bisimulation/coinduction with domain package:
   801 
   802   - Definitions of "bisim" constants no longer mention definedness.
   803   - With mutual recursion, "bisim" predicate is now curried.
   804   - With mutual recursion, each type gets a separate coind theorem.
   805   - Variable names in bisim_def and coinduct rules have changed.
   806 
   807 INCOMPATIBILITY.
   808 
   809 * Case combinators generated by the domain package for type "foo" are
   810 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   811 
   812 * Several theorems have been renamed to more accurately reflect the
   813 names of constants and types involved.  INCOMPATIBILITY.
   814 
   815   thelub_const    ~> lub_const
   816   lub_const       ~> is_lub_const
   817   thelubI         ~> lub_eqI
   818   is_lub_lub      ~> is_lubD2
   819   lubI            ~> is_lub_lub
   820   unique_lub      ~> is_lub_unique
   821   is_ub_lub       ~> is_lub_rangeD1
   822   lub_bin_chain   ~> is_lub_bin_chain
   823   lub_fun         ~> is_lub_fun
   824   thelub_fun      ~> lub_fun
   825   thelub_cfun     ~> lub_cfun
   826   thelub_Pair     ~> lub_Pair
   827   lub_cprod       ~> is_lub_prod
   828   thelub_cprod    ~> lub_prod
   829   minimal_cprod   ~> minimal_prod
   830   inst_cprod_pcpo ~> inst_prod_pcpo
   831   UU_I            ~> bottomI
   832   compact_UU      ~> compact_bottom
   833   deflation_UU    ~> deflation_bottom
   834   finite_deflation_UU ~> finite_deflation_bottom
   835 
   836 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   837 
   838   sq_ord_less_eq_trans ~> below_eq_trans
   839   sq_ord_eq_less_trans ~> eq_below_trans
   840   refl_less            ~> below_refl
   841   trans_less           ~> below_trans
   842   antisym_less         ~> below_antisym
   843   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   844   box_less             ~> box_below
   845   rev_trans_less       ~> rev_below_trans
   846   not_less2not_eq      ~> not_below2not_eq
   847   less_UU_iff          ~> below_UU_iff
   848   flat_less_iff        ~> flat_below_iff
   849   adm_less             ~> adm_below
   850   adm_not_less         ~> adm_not_below
   851   adm_compact_not_less ~> adm_compact_not_below
   852   less_fun_def         ~> below_fun_def
   853   expand_fun_less      ~> fun_below_iff
   854   less_fun_ext         ~> fun_belowI
   855   less_discr_def       ~> below_discr_def
   856   discr_less_eq        ~> discr_below_eq
   857   less_unit_def        ~> below_unit_def
   858   less_cprod_def       ~> below_prod_def
   859   prod_lessI           ~> prod_belowI
   860   Pair_less_iff        ~> Pair_below_iff
   861   fst_less_iff         ~> fst_below_iff
   862   snd_less_iff         ~> snd_below_iff
   863   expand_cfun_less     ~> cfun_below_iff
   864   less_cfun_ext        ~> cfun_belowI
   865   injection_less       ~> injection_below
   866   less_up_def          ~> below_up_def
   867   not_Iup_less         ~> not_Iup_below
   868   Iup_less             ~> Iup_below
   869   up_less              ~> up_below
   870   Def_inject_less_eq   ~> Def_below_Def
   871   Def_less_is_eq       ~> Def_below_iff
   872   spair_less_iff       ~> spair_below_iff
   873   less_sprod           ~> below_sprod
   874   spair_less           ~> spair_below
   875   sfst_less_iff        ~> sfst_below_iff
   876   ssnd_less_iff        ~> ssnd_below_iff
   877   fix_least_less       ~> fix_least_below
   878   dist_less_one        ~> dist_below_one
   879   less_ONE             ~> below_ONE
   880   ONE_less_iff         ~> ONE_below_iff
   881   less_sinlD           ~> below_sinlD
   882   less_sinrD           ~> below_sinrD
   883 
   884 
   885 *** FOL and ZF ***
   886 
   887 * All constant names are now qualified internally and use proper
   888 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   889 
   890 
   891 *** ML ***
   892 
   893 * Antiquotation @{assert} inlines a function bool -> unit that raises
   894 Fail if the argument is false.  Due to inlining the source position of
   895 failed assertions is included in the error output.
   896 
   897 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   898 text is in practice always evaluated with a stable theory checkpoint.
   899 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   900 
   901 * Antiquotation @{theory A} refers to theory A from the ancestry of
   902 the current context, not any accidental theory loader state as before.
   903 Potential INCOMPATIBILITY, subtle change in semantics.
   904 
   905 * Syntax.pretty_priority (default 0) configures the required priority
   906 of pretty-printed output and thus affects insertion of parentheses.
   907 
   908 * Syntax.default_root (default "any") configures the inner syntax
   909 category (nonterminal symbol) for parsing of terms.
   910 
   911 * Former exception Library.UnequalLengths now coincides with
   912 ListPair.UnequalLengths.
   913 
   914 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   915 main functionality is provided by structure Simplifier.
   916 
   917 * Renamed raw "explode" function to "raw_explode" to emphasize its
   918 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   919 almost all situations.
   920 
   921 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   922 See implementation manual for further details on exceptions in
   923 Isabelle/ML.
   924 
   925 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   926 meaning.
   927 
   928 * Renamed structure PureThy to Pure_Thy and moved most of its
   929 operations to structure Global_Theory, to emphasize that this is
   930 rarely-used global-only stuff.
   931 
   932 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   933 instead (or tracing for high-volume output).
   934 
   935 * Configuration option show_question_marks only affects regular pretty
   936 printing of types and terms, not raw Term.string_of_vname.
   937 
   938 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   939 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   940 @{thms} for most purposes.
   941 
   942 * ML structure Unsynchronized is never opened, not even in Isar
   943 interaction mode as before.  Old Unsynchronized.set etc. have been
   944 discontinued -- use plain := instead.  This should be *rare* anyway,
   945 since modern tools always work via official context data, notably
   946 configuration options.
   947 
   948 * Parallel and asynchronous execution requires special care concerning
   949 interrupts.  Structure Exn provides some convenience functions that
   950 avoid working directly with raw Interrupt.  User code must not absorb
   951 interrupts -- intermediate handling (for cleanup etc.) needs to be
   952 followed by re-raising of the original exception.  Another common
   953 source of mistakes are "handle _" patterns, which make the meaning of
   954 the program subject to physical effects of the environment.
   955 
   956 
   957 
   958 New in Isabelle2009-2 (June 2010)
   959 ---------------------------------
   960 
   961 *** General ***
   962 
   963 * Authentic syntax for *all* logical entities (type classes, type
   964 constructors, term constants): provides simple and robust
   965 correspondence between formal entities and concrete syntax.  Within
   966 the parse tree / AST representations, "constants" are decorated by
   967 their category (class, type, const) and spelled out explicitly with
   968 their full internal name.
   969 
   970 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   971 and translations (translation rules and translation functions in ML).
   972 Some hints on upgrading:
   973 
   974   - Many existing uses of 'syntax' and 'translations' can be replaced
   975     by more modern 'type_notation', 'notation' and 'abbreviation',
   976     which are independent of this issue.
   977 
   978   - 'translations' require markup within the AST; the term syntax
   979     provides the following special forms:
   980 
   981       CONST c   -- produces syntax version of constant c from context
   982       XCONST c  -- literally c, checked as constant from context
   983       c         -- literally c, if declared by 'syntax'
   984 
   985     Plain identifiers are treated as AST variables -- occasionally the
   986     system indicates accidental variables via the error "rhs contains
   987     extra variables".
   988 
   989     Type classes and type constructors are marked according to their
   990     concrete syntax.  Some old translations rules need to be written
   991     for the "type" category, using type constructor application
   992     instead of pseudo-term application of the default category
   993     "logic".
   994 
   995   - 'parse_translation' etc. in ML may use the following
   996     antiquotations:
   997 
   998       @{class_syntax c}   -- type class c within parse tree / AST
   999       @{term_syntax c}    -- type constructor c within parse tree / AST
  1000       @{const_syntax c}   -- ML version of "CONST c" above
  1001       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1002 
  1003   - Literal types within 'typed_print_translations', i.e. those *not*
  1004     represented as pseudo-terms are represented verbatim.  Use @{class
  1005     c} or @{type_name c} here instead of the above syntax
  1006     antiquotations.
  1007 
  1008 Note that old non-authentic syntax was based on unqualified base
  1009 names, so all of the above "constant" names would coincide.  Recall
  1010 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1011 diagnose syntax problems.
  1012 
  1013 * Type constructors admit general mixfix syntax, not just infix.
  1014 
  1015 * Concrete syntax may be attached to local entities without a proof
  1016 body, too.  This works via regular mixfix annotations for 'fix',
  1017 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1018 similar to the 'notation' command in theory specifications.
  1019 
  1020 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1021 need to specify constant name and syntax separately.  Internal ML
  1022 datatype constructors have been renamed from InfixName to Infix etc.
  1023 Minor INCOMPATIBILITY.
  1024 
  1025 * Schematic theorem statements need to be explicitly markup as such,
  1026 via commands 'schematic_lemma', 'schematic_theorem',
  1027 'schematic_corollary'.  Thus the relevance of the proof is made
  1028 syntactically clear, which impacts performance in a parallel or
  1029 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1030 
  1031 * Use of cumulative prems via "!" in some proof methods has been
  1032 discontinued (old legacy feature).
  1033 
  1034 * References 'trace_simp' and 'debug_simp' have been replaced by
  1035 configuration options stored in the context. Enabling tracing (the
  1036 case of debugging is similar) in proofs works via
  1037 
  1038   using [[trace_simp = true]]
  1039 
  1040 Tracing is then active for all invocations of the simplifier in
  1041 subsequent goal refinement steps. Tracing may also still be enabled or
  1042 disabled via the ProofGeneral settings menu.
  1043 
  1044 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1045 'hide_fact' replace the former 'hide' KIND command.  Minor
  1046 INCOMPATIBILITY.
  1047 
  1048 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1049 more efficient than combinations with -q1 or -q2.
  1050 
  1051 
  1052 *** Pure ***
  1053 
  1054 * Proofterms record type-class reasoning explicitly, using the
  1055 "unconstrain" operation internally.  This eliminates all sort
  1056 constraints from a theorem and proof, introducing explicit
  1057 OFCLASS-premises.  On the proof term level, this operation is
  1058 automatically applied at theorem boundaries, such that closed proofs
  1059 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1060 inspect proof terms.
  1061 
  1062 * Local theory specifications may depend on extra type variables that
  1063 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1064 are added internally.  For example:
  1065 
  1066   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1067 
  1068 * Predicates of locales introduced by classes carry a mandatory
  1069 "class" prefix.  INCOMPATIBILITY.
  1070 
  1071 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1072 
  1073 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1074 'class' instead.
  1075 
  1076 * Command 'code_reflect' allows to incorporate generated ML code into
  1077 runtime environment; replaces immature code_datatype antiquotation.
  1078 INCOMPATIBILITY.
  1079 
  1080 * Code generator: simple concept for abstract datatypes obeying
  1081 invariants.
  1082 
  1083 * Code generator: details of internal data cache have no impact on the
  1084 user space functionality any longer.
  1085 
  1086 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1087 subgoals.  This is more appropriate for interpretations with 'where'.
  1088 INCOMPATIBILITY.
  1089 
  1090 * Command 'example_proof' opens an empty proof body.  This allows to
  1091 experiment with Isar, without producing any persistent result.
  1092 
  1093 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1094 within a local theory context, with explicit checking of the
  1095 constructors involved (in contrast to the raw 'syntax' versions).
  1096 
  1097 * Commands 'types' and 'typedecl' now work within a local theory
  1098 context -- without introducing dependencies on parameters or
  1099 assumptions, which is not possible in Isabelle/Pure.
  1100 
  1101 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1102 within a local theory context.  Minor INCOMPATIBILITY.
  1103 
  1104 
  1105 *** HOL ***
  1106 
  1107 * Command 'typedef' now works within a local theory context -- without
  1108 introducing dependencies on parameters or assumptions, which is not
  1109 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1110 contain multiple interpretations of local typedefs (with different
  1111 non-emptiness proofs), even in a global theory context.
  1112 
  1113 * New package for quotient types.  Commands 'quotient_type' and
  1114 'quotient_definition' may be used for defining types and constants by
  1115 quotient constructions.  An example is the type of integers created by
  1116 quotienting pairs of natural numbers:
  1117 
  1118   fun
  1119     intrel :: "(nat * nat) => (nat * nat) => bool"
  1120   where
  1121     "intrel (x, y) (u, v) = (x + v = u + y)"
  1122 
  1123   quotient_type int = "nat * nat" / intrel
  1124     by (auto simp add: equivp_def expand_fun_eq)
  1125 
  1126   quotient_definition
  1127     "0::int" is "(0::nat, 0::nat)"
  1128 
  1129 The method "lifting" can be used to lift of theorems from the
  1130 underlying "raw" type to the quotient type.  The example
  1131 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1132 construction and provides a reasoning infrastructure for finite sets.
  1133 
  1134 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1135 clash with new theory Quotient in Main HOL.
  1136 
  1137 * Moved the SMT binding into the main HOL session, eliminating
  1138 separate HOL-SMT session.
  1139 
  1140 * List membership infix mem operation is only an input abbreviation.
  1141 INCOMPATIBILITY.
  1142 
  1143 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1144 for future developements; former Library/Word.thy is still present in
  1145 the AFP entry RSAPPS.
  1146 
  1147 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1148 longer shadowed.  INCOMPATIBILITY.
  1149 
  1150 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1151 INCOMPATIBILITY.
  1152 
  1153 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1154 INCOMPATIBILITY.
  1155 
  1156 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1157 instead.  INCOMPATIBILITY.
  1158 
  1159 * Dropped several real-specific versions of lemmas about floor and
  1160 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1161 instead.  INCOMPATIBILITY.
  1162 
  1163   floor_number_of_eq         ~> floor_number_of
  1164   le_floor_eq_number_of      ~> number_of_le_floor
  1165   le_floor_eq_zero           ~> zero_le_floor
  1166   le_floor_eq_one            ~> one_le_floor
  1167   floor_less_eq_number_of    ~> floor_less_number_of
  1168   floor_less_eq_zero         ~> floor_less_zero
  1169   floor_less_eq_one          ~> floor_less_one
  1170   less_floor_eq_number_of    ~> number_of_less_floor
  1171   less_floor_eq_zero         ~> zero_less_floor
  1172   less_floor_eq_one          ~> one_less_floor
  1173   floor_le_eq_number_of      ~> floor_le_number_of
  1174   floor_le_eq_zero           ~> floor_le_zero
  1175   floor_le_eq_one            ~> floor_le_one
  1176   floor_subtract_number_of   ~> floor_diff_number_of
  1177   floor_subtract_one         ~> floor_diff_one
  1178   ceiling_number_of_eq       ~> ceiling_number_of
  1179   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1180   ceiling_le_zero_eq         ~> ceiling_le_zero
  1181   ceiling_le_eq_one          ~> ceiling_le_one
  1182   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1183   less_ceiling_eq_zero       ~> zero_less_ceiling
  1184   less_ceiling_eq_one        ~> one_less_ceiling
  1185   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1186   ceiling_less_eq_zero       ~> ceiling_less_zero
  1187   ceiling_less_eq_one        ~> ceiling_less_one
  1188   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1189   le_ceiling_eq_zero         ~> zero_le_ceiling
  1190   le_ceiling_eq_one          ~> one_le_ceiling
  1191   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1192   ceiling_subtract_one       ~> ceiling_diff_one
  1193 
  1194 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1195 application of the various fold combinators on finite sets.
  1196 
  1197 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1198 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1199 implementation.  INCOMPATIBILTY.
  1200 
  1201 * Theory Library/Coinductive_List has been removed -- superseded by
  1202 AFP/thys/Coinductive.
  1203 
  1204 * Theory PReal, including the type "preal" and related operations, has
  1205 been removed.  INCOMPATIBILITY.
  1206 
  1207 * Real: new development using Cauchy Sequences.
  1208 
  1209 * Split off theory "Big_Operators" containing setsum, setprod,
  1210 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1211 
  1212 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1213 "Int" etc.  INCOMPATIBILITY.
  1214 
  1215 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1216 
  1217 * New set of rules "ac_simps" provides combined assoc / commute
  1218 rewrites for all interpretations of the appropriate generic locales.
  1219 
  1220 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1221 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1222 appropriate and more consistent names suitable for name prefixes
  1223 within the HOL theories.  INCOMPATIBILITY.
  1224 
  1225 * Some generic constants have been put to appropriate theories:
  1226   - less_eq, less: Orderings
  1227   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1228   - inverse, divide: Rings
  1229 INCOMPATIBILITY.
  1230 
  1231 * More consistent naming of type classes involving orderings (and
  1232 lattices):
  1233 
  1234     lower_semilattice                   ~> semilattice_inf
  1235     upper_semilattice                   ~> semilattice_sup
  1236 
  1237     dense_linear_order                  ~> dense_linorder
  1238 
  1239     pordered_ab_group_add               ~> ordered_ab_group_add
  1240     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1241     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1242     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1243     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1244     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1245     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1246     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1247     pordered_comm_ring                  ~> ordered_comm_ring
  1248     pordered_comm_semiring              ~> ordered_comm_semiring
  1249     pordered_ring                       ~> ordered_ring
  1250     pordered_ring_abs                   ~> ordered_ring_abs
  1251     pordered_semiring                   ~> ordered_semiring
  1252 
  1253     ordered_ab_group_add                ~> linordered_ab_group_add
  1254     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1255     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1256     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1257     ordered_field                       ~> linordered_field
  1258     ordered_field_no_lb                 ~> linordered_field_no_lb
  1259     ordered_field_no_ub                 ~> linordered_field_no_ub
  1260     ordered_field_dense_linear_order    ~> dense_linordered_field
  1261     ordered_idom                        ~> linordered_idom
  1262     ordered_ring                        ~> linordered_ring
  1263     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1264     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1265     ordered_ring_strict                 ~> linordered_ring_strict
  1266     ordered_semidom                     ~> linordered_semidom
  1267     ordered_semiring                    ~> linordered_semiring
  1268     ordered_semiring_1                  ~> linordered_semiring_1
  1269     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1270     ordered_semiring_strict             ~> linordered_semiring_strict
  1271 
  1272   The following slightly odd type classes have been moved to a
  1273   separate theory Library/Lattice_Algebras:
  1274 
  1275     lordered_ab_group_add               ~> lattice_ab_group_add
  1276     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1277     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1278     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1279     lordered_ring                       ~> lattice_ring
  1280 
  1281 INCOMPATIBILITY.
  1282 
  1283 * Refined field classes:
  1284   - classes division_ring_inverse_zero, field_inverse_zero,
  1285     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1286     subsumes former division_by_zero class;
  1287   - numerous lemmas have been ported from field to division_ring.
  1288 INCOMPATIBILITY.
  1289 
  1290 * Refined algebra theorem collections:
  1291   - dropped theorem group group_simps, use algebra_simps instead;
  1292   - dropped theorem group ring_simps, use field_simps instead;
  1293   - proper theorem collection field_simps subsumes former theorem
  1294     groups field_eq_simps and field_simps;
  1295   - dropped lemma eq_minus_self_iff which is a duplicate for
  1296     equal_neg_zero.
  1297 INCOMPATIBILITY.
  1298 
  1299 * Theory Finite_Set and List: some lemmas have been generalized from
  1300 sets to lattices:
  1301 
  1302   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1303   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1304   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1305   union_Union_fold_union        ~> sup_Sup_fold_sup
  1306   Inter_fold_inter              ~> Inf_fold_inf
  1307   Union_fold_union              ~> Sup_fold_sup
  1308   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1309   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1310   INTER_fold_inter              ~> INFI_fold_inf
  1311   UNION_fold_union              ~> SUPR_fold_sup
  1312 
  1313 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1314 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1315 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1316 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1317 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1318 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1319 
  1320 * Reorganized theory Multiset: swapped notation of pointwise and
  1321 multiset order:
  1322 
  1323   - pointwise ordering is instance of class order with standard syntax
  1324     <= and <;
  1325   - multiset ordering has syntax <=# and <#; partial order properties
  1326     are provided by means of interpretation with prefix
  1327     multiset_order;
  1328   - less duplication, less historical organization of sections,
  1329     conversion from associations lists to multisets, rudimentary code
  1330     generation;
  1331   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1332     if needed.
  1333 
  1334 Renamed:
  1335 
  1336   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1337   multi_count_ext  ~>  multiset_ext
  1338   diff_union_inverse2  ~>  diff_union_cancelR
  1339 
  1340 INCOMPATIBILITY.
  1341 
  1342 * Theory Permutation: replaced local "remove" by List.remove1.
  1343 
  1344 * Code generation: ML and OCaml code is decorated with signatures.
  1345 
  1346 * Theory List: added transpose.
  1347 
  1348 * Library/Nat_Bijection.thy is a collection of bijective functions
  1349 between nat and other types, which supersedes the older libraries
  1350 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1351 
  1352   Constants:
  1353   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1354   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1355   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1356   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1357   Countable.pair_encode           ~> prod_encode
  1358   NatIso.prod2nat                 ~> prod_encode
  1359   NatIso.nat2prod                 ~> prod_decode
  1360   NatIso.sum2nat                  ~> sum_encode
  1361   NatIso.nat2sum                  ~> sum_decode
  1362   NatIso.list2nat                 ~> list_encode
  1363   NatIso.nat2list                 ~> list_decode
  1364   NatIso.set2nat                  ~> set_encode
  1365   NatIso.nat2set                  ~> set_decode
  1366 
  1367   Lemmas:
  1368   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1369   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1370   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1371   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1372   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1373   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1374   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1375   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1376   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1377   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1378   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1379   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1380   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1381 
  1382 * Sledgehammer:
  1383   - Renamed ATP commands:
  1384     atp_info     ~> sledgehammer running_atps
  1385     atp_kill     ~> sledgehammer kill_atps
  1386     atp_messages ~> sledgehammer messages
  1387     atp_minimize ~> sledgehammer minimize
  1388     print_atps   ~> sledgehammer available_atps
  1389     INCOMPATIBILITY.
  1390   - Added user's manual ("isabelle doc sledgehammer").
  1391   - Added option syntax and "sledgehammer_params" to customize
  1392     Sledgehammer's behavior.  See the manual for details.
  1393   - Modified the Isar proof reconstruction code so that it produces
  1394     direct proofs rather than proofs by contradiction.  (This feature
  1395     is still experimental.)
  1396   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1397     full-typed mode.
  1398   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1399 
  1400 * Nitpick:
  1401   - Added and implemented "binary_ints" and "bits" options.
  1402   - Added "std" option and implemented support for nonstandard models.
  1403   - Added and implemented "finitize" option to improve the precision
  1404     of infinite datatypes based on a monotonicity analysis.
  1405   - Added support for quotient types.
  1406   - Added support for "specification" and "ax_specification"
  1407     constructs.
  1408   - Added support for local definitions (for "function" and
  1409     "termination" proofs).
  1410   - Added support for term postprocessors.
  1411   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1412   - Improved efficiency of "destroy_constrs" optimization.
  1413   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1414     record getters.
  1415   - Fixed soundness bug related to higher-order constructors.
  1416   - Fixed soundness bug when "full_descrs" is enabled.
  1417   - Improved precision of set constructs.
  1418   - Added "atoms" option.
  1419   - Added cache to speed up repeated Kodkod invocations on the same
  1420     problems.
  1421   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1422     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1423     "SAT4J_Light".  INCOMPATIBILITY.
  1424   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1425     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1426   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1427 
  1428 * Method "induct" now takes instantiations of the form t, where t is not
  1429   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1430   If this is not intended, t has to be enclosed in parentheses.
  1431   By default, the equalities generated by definitional instantiations
  1432   are pre-simplified, which may cause parameters of inductive cases
  1433   to disappear, or may even delete some of the inductive cases.
  1434   Use "induct (no_simp)" instead of "induct" to restore the old
  1435   behaviour. The (no_simp) option is also understood by the "cases"
  1436   and "nominal_induct" methods, which now perform pre-simplification, too.
  1437   INCOMPATIBILITY.
  1438 
  1439 
  1440 *** HOLCF ***
  1441 
  1442 * Variable names in lemmas generated by the domain package have
  1443 changed; the naming scheme is now consistent with the HOL datatype
  1444 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1445 
  1446 * The domain package no longer defines the function "foo_copy" for
  1447 recursive domain "foo".  The reach lemma is now stated directly in
  1448 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1449 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1450 
  1451 * Most definedness lemmas generated by the domain package (previously
  1452 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1453 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1454 Proofs that used definedness lemmas as intro rules may break,
  1455 potential INCOMPATIBILITY.
  1456 
  1457 * Induction and casedist rules generated by the domain package now
  1458 declare proper case_names (one called "bottom", and one named for each
  1459 constructor).  INCOMPATIBILITY.
  1460 
  1461 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1462 rules are generated for each domain, INCOMPATIBILITY.
  1463 
  1464   foo_bar.reach       ~> foo.reach  bar.reach
  1465   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1466 
  1467 * Some lemmas generated by the domain package have been renamed for
  1468 consistency with the datatype package, INCOMPATIBILITY.
  1469 
  1470   foo.ind        ~> foo.induct
  1471   foo.finite_ind ~> foo.finite_induct
  1472   foo.coind      ~> foo.coinduct
  1473   foo.casedist   ~> foo.exhaust
  1474   foo.exhaust    ~> foo.nchotomy
  1475 
  1476 * For consistency with other definition packages, the fixrec package
  1477 now generates qualified theorem names, INCOMPATIBILITY.
  1478 
  1479   foo_simps  ~> foo.simps
  1480   foo_unfold ~> foo.unfold
  1481   foo_induct ~> foo.induct
  1482 
  1483 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1484 method and internal fixrec proofs now use the default simpset instead.
  1485 INCOMPATIBILITY.
  1486 
  1487 * The "contlub" predicate has been removed.  Proof scripts should use
  1488 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1489 
  1490 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1491 
  1492 * The constants cpair, cfst, and csnd have been removed in favor of
  1493 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1494 
  1495 
  1496 *** ML ***
  1497 
  1498 * Antiquotations for basic formal entities:
  1499 
  1500     @{class NAME}         -- type class
  1501     @{class_syntax NAME}  -- syntax representation of the above
  1502 
  1503     @{type_name NAME}     -- logical type
  1504     @{type_abbrev NAME}   -- type abbreviation
  1505     @{nonterminal NAME}   -- type of concrete syntactic category
  1506     @{type_syntax NAME}   -- syntax representation of any of the above
  1507 
  1508     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1509     @{const_abbrev NAME}  -- abbreviated constant
  1510     @{const_syntax NAME}  -- syntax representation of any of the above
  1511 
  1512 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1513 syntax constant (cf. 'syntax' command).
  1514 
  1515 * Antiquotation @{make_string} inlines a function to print arbitrary
  1516 values similar to the ML toplevel.  The result is compiler dependent
  1517 and may fall back on "?" in certain situations.
  1518 
  1519 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1520 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1521 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1522 not work with the asynchronous Isar document model.
  1523 
  1524 * Configuration options now admit dynamic default values, depending on
  1525 the context or even global references.
  1526 
  1527 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1528 uses an efficient external library if available (for Poly/ML).
  1529 
  1530 * Renamed some important ML structures, while keeping the old names
  1531 for some time as aliases within the structure Legacy:
  1532 
  1533   OuterKeyword  ~>  Keyword
  1534   OuterLex      ~>  Token
  1535   OuterParse    ~>  Parse
  1536   OuterSyntax   ~>  Outer_Syntax
  1537   PrintMode     ~>  Print_Mode
  1538   SpecParse     ~>  Parse_Spec
  1539   ThyInfo       ~>  Thy_Info
  1540   ThyLoad       ~>  Thy_Load
  1541   ThyOutput     ~>  Thy_Output
  1542   TypeInfer     ~>  Type_Infer
  1543 
  1544 Note that "open Legacy" simplifies porting of sources, but forgetting
  1545 to remove it again will complicate porting again in the future.
  1546 
  1547 * Most operations that refer to a global context are named
  1548 accordingly, e.g. Simplifier.global_context or
  1549 ProofContext.init_global.  There are some situations where a global
  1550 context actually works, but under normal circumstances one needs to
  1551 pass the proper local context through the code!
  1552 
  1553 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1554 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1555 Pretty.pp argument to merge, which is absent in the standard
  1556 Theory_Data version.
  1557 
  1558 * Sorts.certify_sort and derived "cert" operations for types and terms
  1559 no longer minimize sorts.  Thus certification at the boundary of the
  1560 inference kernel becomes invariant under addition of class relations,
  1561 which is an important monotonicity principle.  Sorts are now minimized
  1562 in the syntax layer only, at the boundary between the end-user and the
  1563 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1564 explicitly in rare situations.
  1565 
  1566 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1567 emphasize that this is in no way a standard operation.
  1568 INCOMPATIBILITY.
  1569 
  1570 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1571 usual for resolution.  Rare INCOMPATIBILITY.
  1572 
  1573 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1574 to emphasize that these only work in a global situation (which is
  1575 quite rare).
  1576 
  1577 * Curried take and drop in library.ML; negative length is interpreted
  1578 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1579 
  1580 * Proof terms: type substitutions on proof constants now use canonical
  1581 order of type variables.  INCOMPATIBILITY for tools working with proof
  1582 terms.
  1583 
  1584 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1585 may no longer carry premises.  User-level specifications are
  1586 transformed accordingly by Thm.add_axiom/add_def.
  1587 
  1588 
  1589 *** System ***
  1590 
  1591 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1592 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1593 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1594 
  1595 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1596 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1597 respectively.
  1598 
  1599 * Old lib/scripts/polyml-platform is superseded by the
  1600 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1601 variant, even on a 64 bit machine.  The following example setting
  1602 prefers 64 bit if available:
  1603 
  1604   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1605 
  1606 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1607 Isabelle/Scala layer for advanced prover interaction and integration.
  1608 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1609 component.
  1610 
  1611 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1612 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1613 similar to the default assignment of the document preparation system
  1614 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1615 provides some operations for direct access to the font without asking
  1616 the user for manual installation.
  1617 
  1618 
  1619 
  1620 New in Isabelle2009-1 (December 2009)
  1621 -------------------------------------
  1622 
  1623 *** General ***
  1624 
  1625 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1626 one backslash should be used, even in ML sources.
  1627 
  1628 
  1629 *** Pure ***
  1630 
  1631 * Locale interpretation propagates mixins along the locale hierarchy.
  1632 The currently only available mixins are the equations used to map
  1633 local definitions to terms of the target domain of an interpretation.
  1634 
  1635 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1636 loc" to print all interpretations of locale "loc" in the theory.
  1637 Interpretations in proofs are not shown.
  1638 
  1639 * Thoroughly revised locales tutorial.  New section on conditional
  1640 interpretation.
  1641 
  1642 * On instantiation of classes, remaining undefined class parameters
  1643 are formally declared.  INCOMPATIBILITY.
  1644 
  1645 
  1646 *** Document preparation ***
  1647 
  1648 * New generalized style concept for printing terms: @{foo (style) ...}
  1649 instead of @{foo_style style ...}  (old form is still retained for
  1650 backward compatibility).  Styles can be also applied for
  1651 antiquotations prop, term_type and typeof.
  1652 
  1653 
  1654 *** HOL ***
  1655 
  1656 * New proof method "smt" for a combination of first-order logic with
  1657 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1658 fixed-size bitvectors; there is also basic support for higher-order
  1659 features (esp. lambda abstractions).  It is an incomplete decision
  1660 procedure based on external SMT solvers using the oracle mechanism;
  1661 for the SMT solver Z3, this method is proof-producing.  Certificates
  1662 are provided to avoid calling the external solvers solely for
  1663 re-checking proofs.  Due to a remote SMT service there is no need for
  1664 installing SMT solvers locally.  See src/HOL/SMT.
  1665 
  1666 * New commands to load and prove verification conditions generated by
  1667 the Boogie program verifier or derived systems (e.g. the Verifying C
  1668 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1669 
  1670 * New counterexample generator tool 'nitpick' based on the Kodkod
  1671 relational model finder.  See src/HOL/Tools/Nitpick and
  1672 src/HOL/Nitpick_Examples.
  1673 
  1674 * New commands 'code_pred' and 'values' to invoke the predicate
  1675 compiler and to enumerate values of inductive predicates.
  1676 
  1677 * A tabled implementation of the reflexive transitive closure.
  1678 
  1679 * New implementation of quickcheck uses generic code generator;
  1680 default generators are provided for all suitable HOL types, records
  1681 and datatypes.  Old quickcheck can be re-activated importing theory
  1682 Library/SML_Quickcheck.
  1683 
  1684 * New testing tool Mirabelle for automated proof tools.  Applies
  1685 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1686 every proof step in a theory.  To be used in batch mode via the
  1687 "mirabelle" utility.
  1688 
  1689 * New proof method "sos" (sum of squares) for nonlinear real
  1690 arithmetic (originally due to John Harison). It requires theory
  1691 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1692 works well in practice on quantifier-free real arithmetic with +, -,
  1693 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1694 inequalities between polynomials.  It makes use of external
  1695 semidefinite programming solvers.  Method "sos" generates a
  1696 certificate that can be pasted into the proof thus avoiding the need
  1697 to call an external tool every time the proof is checked.  See
  1698 src/HOL/Library/Sum_Of_Squares.
  1699 
  1700 * New method "linarith" invokes existing linear arithmetic decision
  1701 procedure only.
  1702 
  1703 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1704 
  1705 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1706 Causes full type information to be output to the ATPs.  This slows
  1707 ATPs down considerably but eliminates a source of unsound "proofs"
  1708 that fail later.
  1709 
  1710 * New method "metisFT": A version of metis that uses full type
  1711 information in order to avoid failures of proof reconstruction.
  1712 
  1713 * New evaluator "approximate" approximates an real valued term using
  1714 the same method as the approximation method.
  1715 
  1716 * Method "approximate" now supports arithmetic expressions as
  1717 boundaries of intervals and implements interval splitting and Taylor
  1718 series expansion.
  1719 
  1720 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1721 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1722 
  1723 * New theory SupInf of the supremum and infimum operators for sets of
  1724 reals.
  1725 
  1726 * New theory Probability, which contains a development of measure
  1727 theory, eventually leading to Lebesgue integration and probability.
  1728 
  1729 * Extended Multivariate Analysis to include derivation and Brouwer's
  1730 fixpoint theorem.
  1731 
  1732 * Reorganization of number theory, INCOMPATIBILITY:
  1733   - new number theory development for nat and int, in theories Divides
  1734     and GCD as well as in new session Number_Theory
  1735   - some constants and facts now suffixed with _nat and _int
  1736     accordingly
  1737   - former session NumberTheory now named Old_Number_Theory, including
  1738     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1739   - moved theory Pocklington from src/HOL/Library to
  1740     src/HOL/Old_Number_Theory
  1741 
  1742 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1743 lcm of finite and infinite sets. It is shown that they form a complete
  1744 lattice.
  1745 
  1746 * Class semiring_div requires superclass no_zero_divisors and proof of
  1747 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1748 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1749 generalized to class semiring_div, subsuming former theorems
  1750 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1751 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1752 INCOMPATIBILITY.
  1753 
  1754 * Refinements to lattice classes and sets:
  1755   - less default intro/elim rules in locale variant, more default
  1756     intro/elim rules in class variant: more uniformity
  1757   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1758     le_inf_iff
  1759   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1760     sup_aci)
  1761   - renamed ACI to inf_sup_aci
  1762   - new class "boolean_algebra"
  1763   - class "complete_lattice" moved to separate theory
  1764     "Complete_Lattice"; corresponding constants (and abbreviations)
  1765     renamed and with authentic syntax:
  1766     Set.Inf ~>    Complete_Lattice.Inf
  1767     Set.Sup ~>    Complete_Lattice.Sup
  1768     Set.INFI ~>   Complete_Lattice.INFI
  1769     Set.SUPR ~>   Complete_Lattice.SUPR
  1770     Set.Inter ~>  Complete_Lattice.Inter
  1771     Set.Union ~>  Complete_Lattice.Union
  1772     Set.INTER ~>  Complete_Lattice.INTER
  1773     Set.UNION ~>  Complete_Lattice.UNION
  1774   - authentic syntax for
  1775     Set.Pow
  1776     Set.image
  1777   - mere abbreviations:
  1778     Set.empty               (for bot)
  1779     Set.UNIV                (for top)
  1780     Set.inter               (for inf, formerly Set.Int)
  1781     Set.union               (for sup, formerly Set.Un)
  1782     Complete_Lattice.Inter  (for Inf)
  1783     Complete_Lattice.Union  (for Sup)
  1784     Complete_Lattice.INTER  (for INFI)
  1785     Complete_Lattice.UNION  (for SUPR)
  1786   - object-logic definitions as far as appropriate
  1787 
  1788 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1789 Un_subset_iff are explicitly deleted as default simp rules; then also
  1790 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1791 deleted to achieve the desired effect.
  1792 
  1793 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1794 rules by default any longer; the same applies to min_max.inf_absorb1
  1795 etc.  INCOMPATIBILITY.
  1796 
  1797 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1798 pred_set_conv by default.  INCOMPATIBILITY.
  1799 
  1800 * Power operations on relations and functions are now one dedicated
  1801 constant "compow" with infix syntax "^^".  Power operation on
  1802 multiplicative monoids retains syntax "^" and is now defined generic
  1803 in class power.  INCOMPATIBILITY.
  1804 
  1805 * Relation composition "R O S" now has a more standard argument order:
  1806 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1807 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1808 break, since the O_assoc rule was not rewritten like this.  Fix using
  1809 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1810 
  1811 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1812 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1813 INCOMPATIBILITY.
  1814 
  1815 * Most rules produced by inductive and datatype package have mandatory
  1816 prefixes.  INCOMPATIBILITY.
  1817 
  1818 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1819 the attribute of the same name.  Each of the theorems in the list
  1820 DERIV_intros assumes composition with an additional function and
  1821 matches a variable to the derivative, which has to be solved by the
  1822 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1823 of most elementary terms.  Former Maclauren.DERIV_tac and
  1824 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1825 INCOMPATIBILITY.
  1826 
  1827 * Code generator attributes follow the usual underscore convention:
  1828     code_unfold     replaces    code unfold
  1829     code_post       replaces    code post
  1830     etc.
  1831   INCOMPATIBILITY.
  1832 
  1833 * Renamed methods:
  1834     sizechange -> size_change
  1835     induct_scheme -> induction_schema
  1836   INCOMPATIBILITY.
  1837 
  1838 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1839 INCOMPATIBILITY, use "undefined" directly.
  1840 
  1841 * Renamed theorems:
  1842     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1843     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1844     Suc_plus1 -> Suc_eq_plus1
  1845     *anti_sym -> *antisym*
  1846     vector_less_eq_def -> vector_le_def
  1847   INCOMPATIBILITY.
  1848 
  1849 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1850 INCOMPATIBILITY.
  1851 
  1852 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1853 INCOMPATIBILITY.
  1854 
  1855 
  1856 *** HOLCF ***
  1857 
  1858 * Theory Representable defines a class "rep" of domains that are
  1859 representable (via an ep-pair) in the universal domain type "udom".
  1860 Instances are provided for all type constructors defined in HOLCF.
  1861 
  1862 * The 'new_domain' command is a purely definitional version of the
  1863 domain package, for representable domains.  Syntax is identical to the
  1864 old domain package.  The 'new_domain' package also supports indirect
  1865 recursion using previously-defined type constructors.  See
  1866 src/HOLCF/ex/New_Domain.thy for examples.
  1867 
  1868 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1869 on the left-hand side of an equation, and then performs
  1870 simplification.  Rewriting is done using rules declared with the
  1871 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1872 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1873 
  1874 * The pattern-match compiler in 'fixrec' can now handle constructors
  1875 with HOL function types.  Pattern-match combinators for the Pair
  1876 constructor are pre-configured.
  1877 
  1878 * The 'fixrec' package now produces better fixed-point induction rules
  1879 for mutually-recursive definitions:  Induction rules have conclusions
  1880 of the form "P foo bar" instead of "P <foo, bar>".
  1881 
  1882 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1883 been renamed to "below".  The name "below" now replaces "less" in many
  1884 theorem names.  (Legacy theorem names using "less" are still supported
  1885 as well.)
  1886 
  1887 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1888 patterns can be used to generate strictness rules, or to make
  1889 functions more strict (much like the bang-patterns supported by the
  1890 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1891 examples.
  1892 
  1893 
  1894 *** ML ***
  1895 
  1896 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1897 errors and run-time exceptions, including detailed source positions.
  1898 
  1899 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1900 identified entries, with some additional information such as source
  1901 position, logical grouping etc.
  1902 
  1903 * Theory and context data is now introduced by the simplified and
  1904 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1905 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1906 copy operation) is still available for some time.
  1907 
  1908 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1909 provides a high-level programming interface to synchronized state
  1910 variables with atomic update.  This works via pure function
  1911 application within a critical section -- its runtime should be as
  1912 short as possible; beware of deadlocks if critical code is nested,
  1913 either directly or indirectly via other synchronized variables!
  1914 
  1915 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1916 wraps raw ML references, explicitly indicating their non-thread-safe
  1917 behaviour.  The Isar toplevel keeps this structure open, to
  1918 accommodate Proof General as well as quick and dirty interactive
  1919 experiments with references.
  1920 
  1921 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1922 parallel tactical reasoning.
  1923 
  1924 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1925 are similar to SUBPROOF, but are slightly more flexible: only the
  1926 specified parts of the subgoal are imported into the context, and the
  1927 body tactic may introduce new subgoals and schematic variables.
  1928 
  1929 * Old tactical METAHYPS, which does not observe the proof context, has
  1930 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1931 or Subgoal.FOCUS etc.
  1932 
  1933 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1934 functors have their own ML name space there is no point to mark them
  1935 separately.)  Minor INCOMPATIBILITY.
  1936 
  1937 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1938 
  1939 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1940 INCOMPATIBILITY.
  1941 
  1942 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1943 mode, which avoids critical setmp.
  1944 
  1945 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1946 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1947 Attrib/Method.setup introduced in Isabelle2009.
  1948 
  1949 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1950 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1951 last resort.  INCOMPATIBILITY.
  1952 
  1953 * Display.pretty_thm now requires a proper context (cf. former
  1954 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1955 or even Display.pretty_thm_without_context as last resort.
  1956 INCOMPATIBILITY.
  1957 
  1958 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1959 Syntax.pretty_typ/term directly, preferably with proper context
  1960 instead of global theory.
  1961 
  1962 
  1963 *** System ***
  1964 
  1965 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1966 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1967 usedir option -q.
  1968 
  1969 * Support for additional "Isabelle components" via etc/components, see
  1970 also the system manual.
  1971 
  1972 * The isabelle makeall tool now operates on all components with
  1973 IsaMakefile, not just hardwired "logics".
  1974 
  1975 * Removed "compress" option from isabelle-process and isabelle usedir;
  1976 this is always enabled.
  1977 
  1978 * Discontinued support for Poly/ML 4.x versions.
  1979 
  1980 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1981 on a given logic image.  This requires the lighttpd webserver and is
  1982 currently supported on Linux only.
  1983 
  1984 
  1985 
  1986 New in Isabelle2009 (April 2009)
  1987 --------------------------------
  1988 
  1989 *** General ***
  1990 
  1991 * Simplified main Isabelle executables, with less surprises on
  1992 case-insensitive file-systems (such as Mac OS).
  1993 
  1994   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1995     "isatool."
  1996 
  1997   - The former "isabelle" alias for "isabelle-process" has been
  1998     removed (should rarely occur to regular users).
  1999 
  2000   - The former "isabelle-interface" and its alias "Isabelle" have been
  2001     removed (interfaces are now regular Isabelle tools).
  2002 
  2003 Within scripts and make files, the Isabelle environment variables
  2004 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2005 respectively.  (The latter are still available as legacy feature.)
  2006 
  2007 The old isabelle-interface wrapper could react in confusing ways if
  2008 the interface was uninstalled or changed otherwise.  Individual
  2009 interface tool configuration is now more explicit, see also the
  2010 Isabelle system manual.  In particular, Proof General is now available
  2011 via "isabelle emacs".
  2012 
  2013 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2014 purge installed copies of Isabelle executables and re-run "isabelle
  2015 install -p ...", or use symlinks.
  2016 
  2017 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2018 old ~/isabelle, which was slightly non-standard and apt to cause
  2019 surprises on case-insensitive file-systems (such as Mac OS).
  2020 
  2021 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2022 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2023 care is required when using older releases of Isabelle.  Note that
  2024 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2025 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2026 
  2027 * Proofs of fully specified statements are run in parallel on
  2028 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2029 a regular 4-core machine, if the initial heap space is made reasonably
  2030 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2031 
  2032 * The main reference manuals ("isar-ref", "implementation", and
  2033 "system") have been updated and extended.  Formally checked references
  2034 as hyperlinks are now available uniformly.
  2035 
  2036 
  2037 *** Pure ***
  2038 
  2039 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2040 respects.  The most important changes are listed below.  See the
  2041 Tutorial on Locales ("locales" manual) for details.
  2042 
  2043 - In locale expressions, instantiation replaces renaming.  Parameters
  2044 must be declared in a for clause.  To aid compatibility with previous
  2045 parameter inheritance, in locale declarations, parameters that are not
  2046 'touched' (instantiation position "_" or omitted) are implicitly added
  2047 with their syntax at the beginning of the for clause.
  2048 
  2049 - Syntax from abbreviations and definitions in locales is available in
  2050 locale expressions and context elements.  The latter is particularly
  2051 useful in locale declarations.
  2052 
  2053 - More flexible mechanisms to qualify names generated by locale
  2054 expressions.  Qualifiers (prefixes) may be specified in locale
  2055 expressions, and can be marked as mandatory (syntax: "name!:") or
  2056 optional (syntax "name?:").  The default depends for plain "name:"
  2057 depends on the situation where a locale expression is used: in
  2058 commands 'locale' and 'sublocale' prefixes are optional, in
  2059 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2060 implicit qualifiers derived from the parameter names of a locale are
  2061 no longer generated.
  2062 
  2063 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2064 instantiation clause in "interpretation" and "interpret" (square
  2065 brackets) is no longer available.  Use locale expressions.
  2066 
  2067 - When converting proof scripts, mandatory qualifiers in
  2068 'interpretation' and 'interpret' should be retained by default, even
  2069 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2070 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2071 in locale expressions range over a single locale instance only.
  2072 
  2073 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2074 In existing theorem specifications replace the includes element by the
  2075 respective context elements of the included locale, omitting those
  2076 that are already present in the theorem specification.  Multiple
  2077 assume elements of a locale should be replaced by a single one
  2078 involving the locale predicate.  In the proof body, declarations (most
  2079 notably theorems) may be regained by interpreting the respective
  2080 locales in the proof context as required (command "interpret").
  2081 
  2082 If using "includes" in replacement of a target solely because the
  2083 parameter types in the theorem are not as general as in the target,
  2084 consider declaring a new locale with additional type constraints on
  2085 the parameters (context element "constrains").
  2086 
  2087 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2088 
  2089 - Locale interpretation commands no longer attempt to simplify goal.
  2090 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2091 methods intro_locales and unfold_locales to clarify.
  2092 
  2093 - Locale interpretation commands no longer accept interpretation
  2094 attributes.  INCOMPATIBILITY.
  2095 
  2096 * Class declaration: so-called "base sort" must not be given in import
  2097 list any longer, but is inferred from the specification.  Particularly
  2098 in HOL, write
  2099 
  2100     class foo = ...
  2101 
  2102 instead of
  2103 
  2104     class foo = type + ...
  2105 
  2106 * Class target: global versions of theorems stemming do not carry a
  2107 parameter prefix any longer.  INCOMPATIBILITY.
  2108 
  2109 * Class 'instance' command no longer accepts attached definitions.
  2110 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2111 
  2112 * Recovered hiding of consts, which was accidentally broken in
  2113 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2114 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2115 
  2116 * Slightly more coherent Pure syntax, with updated documentation in
  2117 isar-ref manual.  Removed locales meta_term_syntax and
  2118 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2119 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2120 directly in regular applications.
  2121 
  2122 * There is a new syntactic category "float_const" for signed decimal
  2123 fractions (e.g. 123.45 or -123.45).
  2124 
  2125 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2126 interface with 'setup' command instead.
  2127 
  2128 * Command 'local_setup' is similar to 'setup', but operates on a local
  2129 theory context.
  2130 
  2131 * The 'axiomatization' command now only works within a global theory
  2132 context.  INCOMPATIBILITY.
  2133 
  2134 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2135 hypotheses.  Sorts required in the course of reasoning need to be
  2136 covered by the constraints in the initial statement, completed by the
  2137 type instance information of the background theory.  Non-trivial sort
  2138 hypotheses, which rarely occur in practice, may be specified via
  2139 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2140 
  2141   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2142 
  2143 The result contains an implicit sort hypotheses as before --
  2144 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2145 normalization.
  2146 
  2147 * Generalized Isar history, with support for linear undo, direct state
  2148 addressing etc.
  2149 
  2150 * Changed defaults for unify configuration options:
  2151 
  2152   unify_trace_bound = 50 (formerly 25)
  2153   unify_search_bound = 60 (formerly 30)
  2154 
  2155 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2156 
  2157   a) On theory merge, the last set of code equations for a particular
  2158      constant is taken (in accordance with the policy applied by other
  2159      parts of the code generator framework).
  2160 
  2161   b) Code equations stemming from explicit declarations (e.g. code
  2162      attribute) gain priority over default code equations stemming
  2163      from definition, primrec, fun etc.
  2164 
  2165 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2166 
  2167 * Unified theorem tables for both code generators.  Thus [code
  2168 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2169 
  2170 * Command 'find_consts' searches for constants based on type and name
  2171 patterns, e.g.
  2172 
  2173     find_consts "_ => bool"
  2174 
  2175 By default, matching is against subtypes, but it may be restricted to
  2176 the whole type.  Searching by name is possible.  Multiple queries are
  2177 conjunctive and queries may be negated by prefixing them with a
  2178 hyphen:
  2179 
  2180     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2181 
  2182 * New 'find_theorems' criterion "solves" matches theorems that
  2183 directly solve the current goal (modulo higher-order unification).
  2184 
  2185 * Auto solve feature for main theorem statements: whenever a new goal
  2186 is stated, "find_theorems solves" is called; any theorems that could
  2187 solve the lemma directly are listed as part of the goal state.
  2188 Cf. associated options in Proof General Isabelle settings menu,
  2189 enabled by default, with reasonable timeout for pathological cases of
  2190 higher-order unification.
  2191 
  2192 
  2193 *** Document preparation ***
  2194 
  2195 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2196 demanding keyword 'by' and supporting the full method expression
  2197 syntax just like the Isar command 'by'.
  2198 
  2199 
  2200 *** HOL ***
  2201 
  2202 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2203 points Main and Complex_Main remain as before.
  2204 
  2205 * Logic image HOL-Plain provides a minimal HOL with the most important
  2206 tools available (inductive, datatype, primrec, ...).  This facilitates
  2207 experimentation and tool development.  Note that user applications
  2208 (and library theories) should never refer to anything below theory
  2209 Main, as before.
  2210 
  2211 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2212 experimentation due to shorter build times.
  2213 
  2214 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2215 were previously part of former HOL-Complex.  Entry point Hyperreal
  2216 remains valid, but theories formerly using Complex_Main should now use
  2217 new entry point Hypercomplex.
  2218 
  2219 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2220 Posix processes.  Avoids potentially expensive forking of the ML
  2221 process.  New thread-based implementation also works on non-Unix
  2222 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2223 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2224 commands are covered in the isar-ref manual.
  2225 
  2226 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2227 sledgehammer without local ATP installation (Vampire etc.). Other
  2228 provers may be included via suitable ML wrappers, see also
  2229 src/HOL/ATP_Linkup.thy.
  2230 
  2231 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2232 menu.
  2233 
  2234 * The metis method no longer fails because the theorem is too trivial
  2235 (contains the empty clause).
  2236 
  2237 * The metis method now fails in the usual manner, rather than raising
  2238 an exception, if it determines that it cannot prove the theorem.
  2239 
  2240 * Method "coherent" implements a prover for coherent logic (see also
  2241 src/Tools/coherent.ML).
  2242 
  2243 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2244 "undefined" is the right choice to replace "arbitrary", though
  2245 logically there is no difference.  INCOMPATIBILITY.
  2246 
  2247 * Command "value" now integrates different evaluation mechanisms.  The
  2248 result of the first successful evaluation mechanism is printed.  In
  2249 square brackets a particular named evaluation mechanisms may be
  2250 specified (currently, [SML], [code] or [nbe]).  See further
  2251 src/HOL/ex/Eval_Examples.thy.
  2252 
  2253 * Normalization by evaluation now allows non-leftlinear equations.
  2254 Declare with attribute [code nbe].
  2255 
  2256 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2257 as the structured Isar versions "cases" and "induct", cf. the
  2258 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2259 are now presented as a list of individual projections
  2260 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2261 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2262 rare situations a different rule is selected --- notably nested tuple
  2263 elimination instead of former prod.exhaust: use explicit (case_tac t
  2264 rule: prod.exhaust) here.
  2265 
  2266 * Attributes "cases", "induct", "coinduct" support "del" option.
  2267 
  2268 * Removed fact "case_split_thm", which duplicates "case_split".
  2269 
  2270 * The option datatype has been moved to a new theory Option.  Renamed
  2271 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2272 
  2273 * New predicate "strict_mono" classifies strict functions on partial
  2274 orders.  With strict functions on linear orders, reasoning about
  2275 (in)equalities is facilitated by theorems "strict_mono_eq",
  2276 "strict_mono_less_eq" and "strict_mono_less".
  2277 
  2278 * Some set operations are now proper qualified constants with
  2279 authentic syntax.  INCOMPATIBILITY:
  2280 
  2281     op Int ~>   Set.Int
  2282     op Un ~>    Set.Un
  2283     INTER ~>    Set.INTER
  2284     UNION ~>    Set.UNION
  2285     Inter ~>    Set.Inter
  2286     Union ~>    Set.Union
  2287     {} ~>       Set.empty
  2288     UNIV ~>     Set.UNIV
  2289 
  2290 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2291 theory Set.
  2292 
  2293 * Auxiliary class "itself" has disappeared -- classes without any
  2294 parameter are treated as expected by the 'class' command.
  2295 
  2296 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2297 
  2298 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2299 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2300 
  2301 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2302 method "approximation".  It proves formulas on real values by using
  2303 interval arithmetic.  In the formulas are also the transcendental
  2304 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2305 allowed. For examples see
  2306 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2307 
  2308 * Theory "Reflection" now resides in HOL/Library.
  2309 
  2310 * Entry point to Word library now simply named "Word".
  2311 INCOMPATIBILITY.
  2312 
  2313 * Made source layout more coherent with logical distribution
  2314 structure:
  2315 
  2316     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2317     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2318     src/HOL/Library/GCD.thy ~> src/HOL/
  2319     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2320     src/HOL/Library/Parity.thy ~> src/HOL/
  2321     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2322     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2323     src/HOL/Real/Lubs.thy ~> src/HOL/
  2324     src/HOL/Real/PReal.thy ~> src/HOL/
  2325     src/HOL/Real/Rational.thy ~> src/HOL/
  2326     src/HOL/Real/RComplete.thy ~> src/HOL/
  2327     src/HOL/Real/RealDef.thy ~> src/HOL/
  2328     src/HOL/Real/RealPow.thy ~> src/HOL/
  2329     src/HOL/Real/Real.thy ~> src/HOL/
  2330     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2331     src/HOL/Complex/Complex.thy ~> src/HOL/
  2332     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2333     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2334     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2335     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2336     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2337     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2338     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2339     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2340     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2341     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2342     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2343     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2344     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2345     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2346     src/HOL/Real/Float ~> src/HOL/Library/
  2347     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2348     src/HOL/Real/RealVector.thy ~> src/HOL/
  2349 
  2350     src/HOL/arith_data.ML ~> src/HOL/Tools
  2351     src/HOL/hologic.ML ~> src/HOL/Tools
  2352     src/HOL/simpdata.ML ~> src/HOL/Tools
  2353     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2354     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2355     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2356     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2357     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2358     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2359     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2360 
  2361     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2362     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2363     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2364     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2365     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2366     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2367 
  2368 * If methods "eval" and "evaluation" encounter a structured proof
  2369 state with !!/==>, only the conclusion is evaluated to True (if
  2370 possible), avoiding strange error messages.
  2371 
  2372 * Method "sizechange" automates termination proofs using (a
  2373 modification of) the size-change principle.  Requires SAT solver.  See
  2374 src/HOL/ex/Termination.thy for examples.
  2375 
  2376 * Simplifier: simproc for let expressions now unfolds if bound
  2377 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2378 
  2379 * Method "arith": Linear arithmetic now ignores all inequalities when
  2380 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2381 
  2382 * New attribute "arith" for facts that should always be used
  2383 automatically by arithmetic. It is intended to be used locally in
  2384 proofs, e.g.
  2385 
  2386   assumes [arith]: "x > 0"
  2387 
  2388 Global usage is discouraged because of possible performance impact.
  2389 
  2390 * New classes "top" and "bot" with corresponding operations "top" and
  2391 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2392 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2393 
  2394 * Changed definition lemma "less_fun_def" in order to provide an
  2395 instance for preorders on functions; use lemma "less_le" instead.
  2396 INCOMPATIBILITY.
  2397 
  2398 * Theory Orderings: class "wellorder" moved here, with explicit
  2399 induction rule "less_induct" as assumption.  For instantiation of
  2400 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2401 INCOMPATIBILITY.
  2402 
  2403 * Theory Orderings: added class "preorder" as superclass of "order".
  2404 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2405 etc. slightly changed.  Some theorems named order_class.* now named
  2406 preorder_class.*.
  2407 
  2408 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2409 "diag" to "Id_on".
  2410 
  2411 * Theory Finite_Set: added a new fold combinator of type
  2412 
  2413   ('a => 'b => 'b) => 'b => 'a set => 'b
  2414 
  2415 Occasionally this is more convenient than the old fold combinator
  2416 which is now defined in terms of the new one and renamed to
  2417 fold_image.
  2418 
  2419 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2420 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2421 extended with further lemmas!).  At the moment both still exist but
  2422 the former will disappear at some point.
  2423 
  2424 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2425 class recpower.  Type-specific simp rules for various recpower types
  2426 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2427 
  2428 rat_power_0    -> power_0
  2429 rat_power_Suc  -> power_Suc
  2430 realpow_0      -> power_0
  2431 realpow_Suc    -> power_Suc
  2432 complexpow_0   -> power_0
  2433 complexpow_Suc -> power_Suc
  2434 power_poly_0   -> power_0
  2435 power_poly_Suc -> power_Suc
  2436 
  2437 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2438 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2439 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2440 of lemmas from Divides has been generalized from nat to class
  2441 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2442 renames resulting from duplicate elimination:
  2443 
  2444     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2445     zero_dvd_iff ~>         dvd_0_left_iff
  2446     dvd_0 ~>                dvd_0_right
  2447     DIVISION_BY_ZERO_DIV ~> div_by_0
  2448     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2449     mult_div ~>             div_mult_self2_is_id
  2450     mult_mod ~>             mod_mult_self2_is_0
  2451 
  2452 * Theory IntDiv: removed many lemmas that are instances of class-based
  2453 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2454 rename old lemmas as follows:
  2455 
  2456 dvd_diff               -> nat_dvd_diff
  2457 dvd_zminus_iff         -> dvd_minus_iff
  2458 mod_add1_eq            -> mod_add_eq
  2459 mod_mult1_eq           -> mod_mult_right_eq
  2460 mod_mult1_eq'          -> mod_mult_left_eq
  2461 mod_mult_distrib_mod   -> mod_mult_eq
  2462 nat_mod_add_left_eq    -> mod_add_left_eq
  2463 nat_mod_add_right_eq   -> mod_add_right_eq
  2464 nat_mod_div_trivial    -> mod_div_trivial
  2465 nat_mod_mod_trivial    -> mod_mod_trivial
  2466 zdiv_zadd_self1        -> div_add_self1
  2467 zdiv_zadd_self2        -> div_add_self2
  2468 zdiv_zmult_self1       -> div_mult_self2_is_id
  2469 zdiv_zmult_self2       -> div_mult_self1_is_id
  2470 zdvd_triv_left         -> dvd_triv_left
  2471 zdvd_triv_right        -> dvd_triv_right
  2472 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2473 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2474 zmod_zadd_left_eq      -> mod_add_left_eq
  2475 zmod_zadd_right_eq     -> mod_add_right_eq
  2476 zmod_zadd_self1        -> mod_add_self1
  2477 zmod_zadd_self2        -> mod_add_self2
  2478 zmod_zadd1_eq          -> mod_add_eq
  2479 zmod_zdiff1_eq         -> mod_diff_eq
  2480 zmod_zdvd_zmod         -> mod_mod_cancel
  2481 zmod_zmod_cancel       -> mod_mod_cancel
  2482 zmod_zmult_self1       -> mod_mult_self2_is_0
  2483 zmod_zmult_self2       -> mod_mult_self1_is_0
  2484 zmod_1                 -> mod_by_1
  2485 zdiv_1                 -> div_by_1
  2486 zdvd_abs1              -> abs_dvd_iff
  2487 zdvd_abs2              -> dvd_abs_iff
  2488 zdvd_refl              -> dvd_refl
  2489 zdvd_trans             -> dvd_trans
  2490 zdvd_zadd              -> dvd_add
  2491 zdvd_zdiff             -> dvd_diff
  2492 zdvd_zminus_iff        -> dvd_minus_iff
  2493 zdvd_zminus2_iff       -> minus_dvd_iff
  2494 zdvd_zmultD            -> dvd_mult_right
  2495 zdvd_zmultD2           -> dvd_mult_left
  2496 zdvd_zmult_mono        -> mult_dvd_mono
  2497 zdvd_0_right           -> dvd_0_right
  2498 zdvd_0_left            -> dvd_0_left_iff
  2499 zdvd_1_left            -> one_dvd
  2500 zminus_dvd_iff         -> minus_dvd_iff
  2501 
  2502 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2503 
  2504 * The real numbers offer decimal input syntax: 12.34 is translated
  2505 into 1234/10^2. This translation is not reversed upon output.
  2506 
  2507 * Theory Library/Polynomial defines an abstract type 'a poly of
  2508 univariate polynomials with coefficients of type 'a.  In addition to
  2509 the standard ring operations, it also supports div and mod.  Code
  2510 generation is also supported, using list-style constructors.
  2511 
  2512 * Theory Library/Inner_Product defines a class of real_inner for real
  2513 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2514 => real.  Class real_inner is a subclass of real_normed_vector from
  2515 theory RealVector.
  2516 
  2517 * Theory Library/Product_Vector provides instances for the product
  2518 type 'a * 'b of several classes from RealVector and Inner_Product.
  2519 Definitions of addition, subtraction, scalar multiplication, norms,
  2520 and inner products are included.
  2521 
  2522 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2523 addition to the field operations, numerals and case syntax are also
  2524 supported.
  2525 
  2526 * Theory Library/Diagonalize provides constructive version of Cantor's
  2527 first diagonalization argument.
  2528 
  2529 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2530 zlcm (for int); carried together from various gcd/lcm developements in
  2531 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2532 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2533 may recover tupled syntax as follows:
  2534 
  2535     hide (open) const gcd
  2536     abbreviation gcd where
  2537       "gcd == (%(a, b). GCD.gcd a b)"
  2538     notation (output)
  2539       GCD.gcd ("gcd '(_, _')")
  2540 
  2541 The same works for lcm, zgcd, zlcm.
  2542 
  2543 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2544 instantiations for algebraic structures.  Removed some duplicate
  2545 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2546 
  2547 * ML antiquotation @{code} takes a constant as argument and generates
  2548 corresponding code in background and inserts name of the corresponding
  2549 resulting ML value/function/datatype constructor binding in place.
  2550 All occurrences of @{code} with a single ML block are generated
  2551 simultaneously.  Provides a generic and safe interface for
  2552 instrumentalizing code generation.  See
  2553 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2554 In future you ought to refrain from ad-hoc compiling generated SML
  2555 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2556 cannot refer to constants for which user-defined serializations are
  2557 set.  Refer to the corresponding ML counterpart directly in that
  2558 cases.
  2559 
  2560 * Command 'rep_datatype': instead of theorem names the command now
  2561 takes a list of terms denoting the constructors of the type to be
  2562 represented as datatype.  The characteristic theorems have to be
  2563 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2564 have disappeared in favour of existing ones:
  2565 
  2566     unit_induct                 ~> unit.induct
  2567     prod_induct                 ~> prod.induct
  2568     sum_induct                  ~> sum.induct
  2569     Suc_Suc_eq                  ~> nat.inject
  2570     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2571 
  2572 
  2573 *** HOL-Algebra ***
  2574 
  2575 * New locales for orders and lattices where the equivalence relation
  2576 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2577 locales use a record structure with field eq for the equivalence.
  2578 
  2579 * New theory of factorial domains.
  2580 
  2581 * Units_l_inv and Units_r_inv are now simp rules by default.
  2582 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2583 and/or r_inv will now also require deletion of these lemmas.
  2584 
  2585 * Renamed the following theorems, INCOMPATIBILITY:
  2586 
  2587 UpperD ~> Upper_memD
  2588 LowerD ~> Lower_memD
  2589 least_carrier ~> least_closed
  2590 greatest_carrier ~> greatest_closed
  2591 greatest_Lower_above ~> greatest_Lower_below
  2592 one_zero ~> carrier_one_zero
  2593 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2594 
  2595 
  2596 *** HOL-Nominal ***
  2597 
  2598 * Nominal datatypes can now contain type-variables.
  2599 
  2600 * Commands 'nominal_inductive' and 'equivariance' work with local
  2601 theory targets.
  2602 
  2603 * Nominal primrec can now works with local theory targets and its
  2604 specification syntax now conforms to the general format as seen in
  2605 'inductive' etc.
  2606 
  2607 * Method "perm_simp" honours the standard simplifier attributes
  2608 (no_asm), (no_asm_use) etc.
  2609 
  2610 * The new predicate #* is defined like freshness, except that on the
  2611 left hand side can be a set or list of atoms.
  2612 
  2613 * Experimental command 'nominal_inductive2' derives strong induction
  2614 principles for inductive definitions.  In contrast to
  2615 'nominal_inductive', which can only deal with a fixed number of
  2616 binders, it can deal with arbitrary expressions standing for sets of
  2617 atoms to be avoided.  The only inductive definition we have at the
  2618 moment that needs this generalisation is the typing rule for Lets in
  2619 the algorithm W:
  2620 
  2621  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2622  -----------------------------------------------------------------
  2623          Gamma |- Let x be t1 in t2 : T2
  2624 
  2625 In this rule one wants to avoid all the binders that are introduced by
  2626 "close Gamma T1".  We are looking for other examples where this
  2627 feature might be useful.  Please let us know.
  2628 
  2629 
  2630 *** HOLCF ***
  2631 
  2632 * Reimplemented the simplification procedure for proving continuity
  2633 subgoals.  The new simproc is extensible; users can declare additional
  2634 continuity introduction rules with the attribute [cont2cont].
  2635 
  2636 * The continuity simproc now uses a different introduction rule for
  2637 solving continuity subgoals on terms with lambda abstractions.  In
  2638 some rare cases the new simproc may fail to solve subgoals that the
  2639 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2640 Potential INCOMPATIBILITY.
  2641 
  2642 * Command 'fixrec': specification syntax now conforms to the general
  2643 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2644 examples.  INCOMPATIBILITY.
  2645 
  2646 
  2647 *** ZF ***
  2648 
  2649 * Proof of Zorn's Lemma for partial orders.
  2650 
  2651 
  2652 *** ML ***
  2653 
  2654 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2655 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2656 depends on multithreading, so timouts will not work before Poly/ML
  2657 5.2.1!
  2658 
  2659 * High-level support for concurrent ML programming, see
  2660 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2661 particularly convenient to organize independent functional
  2662 computations.  The concept of "synchronized variables" provides a
  2663 higher-order interface for components with shared state, avoiding the
  2664 delicate details of mutexes and condition variables.  (Requires
  2665 Poly/ML 5.2.1 or later.)
  2666 
  2667 * ML bindings produced via Isar commands are stored within the Isar
  2668 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2669 become thread-safe and work with undo as expected (concerning
  2670 top-level bindings, not side-effects on global references).
  2671 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2672 compiler at runtime; really global bindings need to be given outside a
  2673 theory.  (Requires Poly/ML 5.2 or later.)
  2674 
  2675 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2676 context.  Top-level ML bindings are stored within the proof context in
  2677 a purely sequential fashion, disregarding the nested proof structure.
  2678 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2679 proof.  (Requires Poly/ML 5.2 or later.)
  2680 
  2681 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2682 and Method.setup, as well as Isar commands 'attribute_setup' and
  2683 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2684 existing code accordingly, or use plain 'setup' together with old
  2685 Method.add_method.
  2686 
  2687 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2688 to 'a -> thm, while results are always tagged with an authentic oracle
  2689 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2690 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2691 accordingly.  Note that extra performance may be gained by producing
  2692 the cterm carefully, avoiding slow Thm.cterm_of.
  2693 
  2694 * Simplified interface for defining document antiquotations via
  2695 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2696 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2697 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2698 examples.
  2699 
  2700 * More systematic treatment of long names, abstract name bindings, and
  2701 name space operations.  Basic operations on qualified names have been
  2702 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2703 Long_Name.append.  Old type bstring has been mostly replaced by
  2704 abstract type binding (see structure Binding), which supports precise
  2705 qualification by packages and local theory targets, as well as proper
  2706 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2707 bstring values into Binding.name, or better pass through abstract
  2708 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2709 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2710 
  2711 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2712 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2713 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2714 
  2715 * Disposed old type and term read functions (Sign.read_def_typ,
  2716 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2717 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2718 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2719 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2720 resort for legacy applications.
  2721 
  2722 * Disposed old declarations, tactics, tactic combinators that refer to
  2723 the simpset or claset of an implicit theory (such as Addsimps,
  2724 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2725 embedded ML text, or local_simpset_of with a proper context passed as
  2726 explicit runtime argument.
  2727 
  2728 * Rules and tactics that read instantiations (read_instantiate,
  2729 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2730 context, which is required for parsing and type-checking.  Moreover,
  2731 the variables are specified as plain indexnames, not string encodings
  2732 thereof.  INCOMPATIBILITY.
  2733 
  2734 * Generic Toplevel.add_hook interface allows to analyze the result of
  2735 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2736 for theorem dependency output of transactions resulting in a new
  2737 theory state.
  2738 
  2739 * ML antiquotations: block-structured compilation context indicated by
  2740 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2741 
  2742   @{binding name}                         - basic name binding
  2743   @{let ?pat = term}                      - term abbreviation (HO matching)
  2744   @{note name = fact}                     - fact abbreviation
  2745   @{thm fact}                             - singleton fact (with attributes)
  2746   @{thms fact}                            - general fact (with attributes)
  2747   @{lemma prop by method}                 - singleton goal
  2748   @{lemma prop by meth1 meth2}            - singleton goal
  2749   @{lemma prop1 ... propN by method}      - general goal
  2750   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2751   @{lemma (open) ...}                     - open derivation
  2752 
  2753 
  2754 *** System ***
  2755 
  2756 * The Isabelle "emacs" tool provides a specific interface to invoke
  2757 Proof General / Emacs, with more explicit failure if that is not
  2758 installed (the old isabelle-interface script silently falls back on
  2759 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2760 installation location of the Proof General distribution.
  2761 
  2762 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2763 the Isabelle process into a JVM/Scala application.  See
  2764 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2765 process wrapper has been discontinued.)
  2766 
  2767 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2768 
  2769 * Various status messages (with exact source position information) are
  2770 emitted, if proper markup print mode is enabled.  This allows
  2771 user-interface components to provide detailed feedback on internal
  2772 prover operations.
  2773 
  2774 
  2775 
  2776 New in Isabelle2008 (June 2008)
  2777 -------------------------------
  2778 
  2779 *** General ***
  2780 
  2781 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2782 and updated, with formally checked references as hyperlinks.
  2783 
  2784 * Theory loader: use_thy (and similar operations) no longer set the
  2785 implicit ML context, which was occasionally hard to predict and in
  2786 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2787 provides a proper context already.
  2788 
  2789 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2790 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2791 'use' within a theory file will do the job.
  2792 
  2793 * Name space merge now observes canonical order, i.e. the second space
  2794 is inserted into the first one, while existing entries in the first
  2795 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2796 swap theory imports.
  2797 
  2798 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2799 INCOMPATIBILITY in identifier syntax etc.
  2800 
  2801 * Outer syntax: string tokens no longer admit escaped white space,
  2802 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2803 white space without escapes.
  2804 
  2805 * Outer syntax: string tokens may contain arbitrary character codes
  2806 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2807 "foo_bar".
  2808 
  2809 
  2810 *** Pure ***
  2811 
  2812 * Context-dependent token translations.  Default setup reverts locally
  2813 fixed variables, and adds hilite markup for undeclared frees.
  2814 
  2815 * Unused theorems can be found using the new command 'unused_thms'.
  2816 There are three ways of invoking it:
  2817 
  2818 (1) unused_thms
  2819      Only finds unused theorems in the current theory.
  2820 
  2821 (2) unused_thms thy_1 ... thy_n -
  2822      Finds unused theorems in the current theory and all of its ancestors,
  2823      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2824 
  2825 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2826      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2827      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2828      their ancestors.
  2829 
  2830 In order to increase the readability of the list produced by
  2831 unused_thms, theorems that have been created by a particular instance
  2832 of a theory command such as 'inductive' or 'function' are considered
  2833 to belong to the same "group", meaning that if at least one theorem in
  2834 this group is used, the other theorems in the same group are no longer
  2835 reported as unused.  Moreover, if all theorems in the group are
  2836 unused, only one theorem in the group is displayed.
  2837 
  2838 Note that proof objects have to be switched on in order for
  2839 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2840 usually the case when using Proof General with the default settings).
  2841 
  2842 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2843 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2844 duplicate fact bindings, or even accidental fact duplications.  Note
  2845 that tools may maintain dynamically scoped facts systematically, using
  2846 PureThy.add_thms_dynamic.
  2847 
  2848 * Command 'hide' now allows to hide from "fact" name space as well.
  2849 
  2850 * Eliminated destructive theorem database, simpset, claset, and
  2851 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2852 update of theories within ML code.
  2853 
  2854 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2855 INCOMPATIBILITY, object-logics depending on former Pure require
  2856 additional setup PureThy.old_appl_syntax_setup; object-logics
  2857 depending on former CPure need to refer to Pure.
  2858 
  2859 * Commands 'use' and 'ML' are now purely functional, operating on
  2860 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2861 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2862 INCOMPATIBILITY.
  2863 
  2864 * Command 'setup': discontinued implicit version with ML reference.
  2865 
  2866 * Instantiation target allows for simultaneous specification of class
  2867 instance operations together with an instantiation proof.
  2868 Type-checking phase allows to refer to class operations uniformly.
  2869 See src/HOL/Complex/Complex.thy for an Isar example and
  2870 src/HOL/Library/Eval.thy for an ML example.
  2871 
  2872 * Indexing of literal facts: be more serious about including only
  2873 facts from the visible specification/proof context, but not the
  2874 background context (locale etc.).  Affects `prop` notation and method
  2875 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2876 situations.
  2877 
  2878 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2879 "(open)" option, which used to expose internal bound variables to the
  2880 proof text.
  2881 
  2882 * Isar statements: removed obsolete case "rule_context".
  2883 INCOMPATIBILITY, better use explicit fixes/assumes.
  2884 
  2885 * Locale proofs: default proof step now includes 'unfold_locales';
  2886 hence 'proof' without argument may be used to unfold locale
  2887 predicates.
  2888 
  2889 
  2890 *** Document preparation ***
  2891 
  2892 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2893 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2894 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2895 spot); renamed link color from "darkblue" to "linkcolor" (default
  2896 value unchanged, can be redefined via \definecolor); no longer sets
  2897 "a4paper" option (unnecessary or even intrusive).
  2898 
  2899 * Antiquotation @{lemma A method} proves proposition A by the given
  2900 method (either a method name or a method name plus (optional) method
  2901 arguments in parentheses) and prints A just like @{prop A}.
  2902 
  2903 
  2904 *** HOL ***
  2905 
  2906 * New primrec package.  Specification syntax conforms in style to
  2907 definition/function/....  No separate induction rule is provided.  The
  2908 "primrec" command distinguishes old-style and new-style specifications
  2909 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2910 When adjusting theories, beware: constants stemming from new-style
  2911 primrec specifications have authentic syntax.
  2912 
  2913 * Metis prover is now an order of magnitude faster, and also works
  2914 with multithreading.
  2915 
  2916 * Metis: the maximum number of clauses that can be produced from a
  2917 theorem is now given by the attribute max_clauses.  Theorems that
  2918 exceed this number are ignored, with a warning printed.
  2919 
  2920 * Sledgehammer no longer produces structured proofs by default. To
  2921 enable, declare [[sledgehammer_full = true]].  Attributes
  2922 reconstruction_modulus, reconstruction_sorts renamed
  2923 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2924 
  2925 * Method "induct_scheme" derives user-specified induction rules
  2926 from well-founded induction and completeness of patterns. This factors
  2927 out some operations that are done internally by the function package
  2928 and makes them available separately.  See
  2929 src/HOL/ex/Induction_Scheme.thy for examples.
  2930 
  2931 * More flexible generation of measure functions for termination
  2932 proofs: Measure functions can be declared by proving a rule of the
  2933 form "is_measure f" and giving it the [measure_function] attribute.
  2934 The "is_measure" predicate is logically meaningless (always true), and
  2935 just guides the heuristic.  To find suitable measure functions, the
  2936 termination prover sets up the goal "is_measure ?f" of the appropriate
  2937 type and generates all solutions by prolog-style backwards proof using
  2938 the declared rules.
  2939 
  2940 This setup also deals with rules like 
  2941 
  2942   "is_measure f ==> is_measure (list_size f)"
  2943 
  2944 which accommodates nested datatypes that recurse through lists.
  2945 Similar rules are predeclared for products and option types.
  2946 
  2947 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2948 
  2949   INCOMPATIBILITIES:
  2950 
  2951   - Definitions of overloaded constants on sets have to be replaced by
  2952     definitions on => and bool.
  2953 
  2954   - Some definitions of overloaded operators on sets can now be proved
  2955     using the definitions of the operators on => and bool.  Therefore,
  2956     the following theorems have been renamed:
  2957 
  2958       subset_def   -> subset_eq
  2959       psubset_def  -> psubset_eq
  2960       set_diff_def -> set_diff_eq
  2961       Compl_def    -> Compl_eq
  2962       Sup_set_def  -> Sup_set_eq
  2963       Inf_set_def  -> Inf_set_eq
  2964       sup_set_def  -> sup_set_eq
  2965       inf_set_def  -> inf_set_eq
  2966 
  2967   - Due to the incompleteness of the HO unification algorithm, some
  2968     rules such as subst may require manual instantiation, if some of
  2969     the unknowns in the rule is a set.
  2970 
  2971   - Higher order unification and forward proofs:
  2972     The proof pattern
  2973 
  2974       have "P (S::'a set)" <...>
  2975       then have "EX S. P S" ..
  2976 
  2977     no longer works (due to the incompleteness of the HO unification
  2978     algorithm) and must be replaced by the pattern
  2979 
  2980       have "EX S. P S"
  2981       proof
  2982         show "P S" <...>
  2983       qed
  2984 
  2985   - Calculational reasoning with subst (or similar rules):
  2986     The proof pattern
  2987 
  2988       have "P (S::'a set)" <...>
  2989       also have "S = T" <...>
  2990       finally have "P T" .
  2991 
  2992     no longer works (for similar reasons as the previous example) and
  2993     must be replaced by something like
  2994 
  2995       have "P (S::'a set)" <...>
  2996       moreover have "S = T" <...>
  2997       ultimately have "P T" by simp
  2998 
  2999   - Tactics or packages written in ML code:
  3000     Code performing pattern matching on types via
  3001 
  3002       Type ("set", [T]) => ...
  3003 
  3004     must be rewritten. Moreover, functions like strip_type or
  3005     binder_types no longer return the right value when applied to a
  3006     type of the form
  3007 
  3008       T1 => ... => Tn => U => bool
  3009 
  3010     rather than
  3011 
  3012       T1 => ... => Tn => U set
  3013 
  3014 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3015 Wellfounded_Relations to theory Wellfounded.
  3016 
  3017 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3018 
  3019 * Class finite no longer treats UNIV as class parameter.  Use class
  3020 enum from theory Library/Enum instead to achieve a similar effect.
  3021 INCOMPATIBILITY.
  3022 
  3023 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3024 and "Cons".  INCOMPATIBILITY.
  3025 
  3026 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3027 Potential INCOMPATIBILITY.
  3028 
  3029 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3030 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3031 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3032 
  3033 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3034 the same name in theory Orderings:
  3035 
  3036   less_trans
  3037   less_linear
  3038   le_imp_less_or_eq
  3039   le_less_trans
  3040   less_le_trans
  3041   less_not_sym
  3042   less_asym
  3043 
  3044 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3045 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3046 and different variable names.
  3047 
  3048 * Library/Option_ord.thy: Canonical order on option type.
  3049 
  3050 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3051 finite maps.
  3052 
  3053 * Library/Countable.thy: Type class for countable types.
  3054 
  3055 * Theory Int: The representation of numerals has changed.  The infix
  3056 operator BIT and the bit datatype with constructors B0 and B1 have
  3057 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3058 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3059 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3060 accordingly.
  3061 
  3062 * Theory Nat: definition of <= and < on natural numbers no longer
  3063 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3064 le_def and less_def have disappeared.  Consider lemmas not_less
  3065 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3066 
  3067 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3068 (whose purpose mainly is for various fold_set functionals) have been
  3069 abandoned in favor of the existing algebraic classes
  3070 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3071 lower_semilattice (resp. upper_semilattice) and linorder.
  3072 INCOMPATIBILITY.
  3073 
  3074 * Theory Transitive_Closure: induct and cases rules now declare proper
  3075 case_names ("base" and "step").  INCOMPATIBILITY.
  3076 
  3077 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3078 lattices.  The form set-specific version is available as
  3079 Inductive.lfp_ordinal_induct_set.
  3080 
  3081 * Renamed theorems "power.simps" to "power_int.simps".
  3082 INCOMPATIBILITY.
  3083 
  3084 * Class semiring_div provides basic abstract properties of semirings
  3085 with division and modulo operations.  Subsumes former class dvd_mod.
  3086 
  3087 * Merged theories IntDef, Numeral and IntArith into unified theory
  3088 Int.  INCOMPATIBILITY.
  3089 
  3090 * Theory Library/Code_Index: type "index" now represents natural
  3091 numbers rather than integers.  INCOMPATIBILITY.
  3092 
  3093 * New class "uminus" with operation "uminus" (split of from class
  3094 "minus" which now only has operation "minus", binary).
  3095 INCOMPATIBILITY.
  3096 
  3097 * Constants "card", "internal_split", "option_map" now with authentic
  3098 syntax.  INCOMPATIBILITY.
  3099 
  3100 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3101 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3102 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3103 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3104 Sup_set_def, le_def, less_def, option_map_def now with object
  3105 equality.  INCOMPATIBILITY.
  3106 
  3107 * Records. Removed K_record, and replaced it by pure lambda term
  3108 %x. c. The simplifier setup is now more robust against eta expansion.
  3109 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3110 
  3111 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3112 
  3113 * Library/ListVector: new theory of arithmetic vector operations.
  3114 
  3115 * Library/Order_Relation: new theory of various orderings as sets of
  3116 pairs.  Defines preorders, partial orders, linear orders and
  3117 well-orders on sets and on types.
  3118 
  3119 
  3120 *** ZF ***
  3121 
  3122 * Renamed some theories to allow to loading both ZF and HOL in the
  3123 same session:
  3124 
  3125   Datatype  -> Datatype_ZF
  3126   Inductive -> Inductive_ZF
  3127   Int       -> Int_ZF
  3128   IntDiv    -> IntDiv_ZF
  3129   Nat       -> Nat_ZF
  3130   List      -> List_ZF
  3131   Main      -> Main_ZF
  3132 
  3133 INCOMPATIBILITY: ZF theories that import individual theories below
  3134 Main might need to be adapted.  Regular theory Main is still
  3135 available, as trivial extension of Main_ZF.
  3136 
  3137 
  3138 *** ML ***
  3139 
  3140 * ML within Isar: antiquotation @{const name} or @{const
  3141 name(typargs)} produces statically-checked Const term.
  3142 
  3143 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3144 (of the same name).  Removed obsolete print command.
  3145 
  3146 * Removed obsolete "use_legacy_bindings" function.
  3147 
  3148 * The ``print mode'' is now a thread-local value derived from a global
  3149 template (the former print_mode reference), thus access becomes
  3150 non-critical.  The global print_mode reference is for session
  3151 management only; user-code should use print_mode_value,
  3152 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3153 
  3154 * Functions system/system_out provide a robust way to invoke external
  3155 shell commands, with propagation of interrupts (requires Poly/ML
  3156 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3157 
  3158 
  3159 *** System ***
  3160 
  3161 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3162 in accordance with Proof General 3.7, which prefers GNU emacs.
  3163 
  3164 * isatool tty runs Isabelle process with plain tty interaction;
  3165 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3166 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3167 
  3168 * isatool browser now works with Cygwin as well, using general
  3169 "javapath" function defined in Isabelle process environment.
  3170 
  3171 * YXML notation provides a simple and efficient alternative to
  3172 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3173 isatool yxml as described in the Isabelle system manual.
  3174 
  3175 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3176 provides general wrapper for managing an Isabelle process in a robust
  3177 fashion, with ``cooked'' output from stdin/stderr.
  3178 
  3179 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3180 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3181 
  3182 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3183 way of changing the user's settings is via
  3184 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3185 script.
  3186 
  3187 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3188 cores of the underlying machine, which is a good starting point for
  3189 optimal performance tuning.  The corresponding usedir option -M allows
  3190 "max" as an alias for "0".  WARNING: does not work on certain versions
  3191 of Mac OS (with Poly/ML 5.1).
  3192 
  3193 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3194 adverse effect of Isabelle flooding interactive front-ends (notably
  3195 ProofGeneral / XEmacs).
  3196 
  3197 
  3198 
  3199 New in Isabelle2007 (November 2007)
  3200 -----------------------------------
  3201 
  3202 *** General ***
  3203 
  3204 * More uniform information about legacy features, notably a
  3205 warning/error of "Legacy feature: ...", depending on the state of the
  3206 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3207 legacy features will disappear eventually.
  3208 
  3209 * Theory syntax: the header format ``theory A = B + C:'' has been
  3210 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3211 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3212 
  3213 * Theory syntax: the old non-Isar theory file format has been
  3214 discontinued altogether.  Note that ML proof scripts may still be used
  3215 with Isar theories; migration is usually quite simple with the ML
  3216 function use_legacy_bindings.  INCOMPATIBILITY.
  3217 
  3218 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3219 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3220 quotes.
  3221 
  3222 * Theory loader: be more serious about observing the static theory
  3223 header specifications (including optional directories), but not the
  3224 accidental file locations of previously successful loads.  The strict
  3225 update policy of former update_thy is now already performed by
  3226 use_thy, so the former has been removed; use_thys updates several
  3227 theories simultaneously, just as 'imports' within a theory header
  3228 specification, but without merging the results.  Potential
  3229 INCOMPATIBILITY: may need to refine theory headers and commands
  3230 ROOT.ML which depend on load order.
  3231 
  3232 * Theory loader: optional support for content-based file
  3233 identification, instead of the traditional scheme of full physical
  3234 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3235 (cf. the system manual).  The new scheme allows to work with
  3236 non-finished theories in persistent session images, such that source
  3237 files may be moved later on without requiring reloads.
  3238 
  3239 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3240 file (with the same base name as the theory) are considered a legacy
  3241 feature, which will disappear eventually. Even now, the theory loader
  3242 no longer maintains dependencies on such files.
  3243 
  3244 * Syntax: the scope for resolving ambiguities via type-inference is
  3245 now limited to individual terms, instead of whole simultaneous
  3246 specifications as before. This greatly reduces the complexity of the
  3247 syntax module and improves flexibility by separating parsing and
  3248 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3249 'fixes' etc.) are required in rare situations.
  3250 
  3251 * Syntax: constants introduced by new-style packages ('definition',
  3252 'abbreviation' etc.) are passed through the syntax module in
  3253 ``authentic mode''. This means that associated mixfix annotations
  3254 really stick to such constants, independently of potential name space
  3255 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3256 trees are represented slightly differently, may need to adapt syntax
  3257 translations accordingly. Use CONST marker in 'translations' and
  3258 @{const_syntax} antiquotation in 'parse_translation' etc.
  3259 
  3260 * Legacy goal package: reduced interface to the bare minimum required
  3261 to keep existing proof scripts running.  Most other user-level
  3262 functions are now part of the OldGoals structure, which is *not* open
  3263 by default (consider isatool expandshort before open OldGoals).
  3264 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3265 these tend to cause confusion about the actual goal (!) context being
  3266 used here, which is not necessarily the same as the_context().
  3267 
  3268 * Command 'find_theorems': supports "*" wild-card in "name:"
  3269 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3270 support a specific search form (see ProofGeneral/CHANGES).
  3271 
  3272 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3273 by default, which means that "prems" (and also "fixed variables") are
  3274 suppressed from proof state output.  Note that the ProofGeneral
  3275 settings mechanism allows to change and save options persistently, but
  3276 older versions of Isabelle will fail to start up if a negative prems
  3277 limit is imposed.
  3278 
  3279 * Local theory targets may be specified by non-nested blocks of
  3280 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3281 contain definitions, theorems etc., including any derived mechanism
  3282 that has been implemented on top of these primitives.  This concept
  3283 generalizes the existing ``theorem (in ...)'' towards more versatility
  3284 and scalability.
  3285 
  3286 * Proof General interface: proper undo of final 'end' command;
  3287 discontinued Isabelle/classic mode (ML proof scripts).
  3288 
  3289 
  3290 *** Document preparation ***
  3291 
  3292 * Added antiquotation @{theory name} which prints the given name,
  3293 after checking that it refers to a valid ancestor theory in the
  3294 current context.
  3295 
  3296 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3297 check the given source text as ML type/structure, printing verbatim.
  3298 
  3299 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3300 "c args == rhs" given in the current context.  (Any number of
  3301 arguments may be given on the LHS.)
  3302 
  3303 
  3304 *** Pure ***
  3305 
  3306 * The 'class' package offers a combination of axclass and locale to
  3307 achieve Haskell-like type classes in Isabelle.  Definitions and
  3308 theorems within a class context produce both relative results (with
  3309 implicit parameters according to the locale context), and polymorphic
  3310 constants with qualified polymorphism (according to the class
  3311 context).  Within the body context of a 'class' target, a separate
  3312 syntax layer ("user space type system") takes care of converting
  3313 between global polymorphic consts and internal locale representation.
  3314 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3315 "isatool doc classes" provides a tutorial.
  3316 
  3317 * Generic code generator framework allows to generate executable
  3318 code for ML and Haskell (including Isabelle classes).  A short usage
  3319 sketch:
  3320 
  3321     internal compilation:
  3322         export_code <list of constants (term syntax)> in SML
  3323     writing SML code to a file:
  3324         export_code <list of constants (term syntax)> in SML <filename>
  3325     writing OCaml code to a file:
  3326         export_code <list of constants (term syntax)> in OCaml <filename>
  3327     writing Haskell code to a bunch of files:
  3328         export_code <list of constants (term syntax)> in Haskell <filename>
  3329 
  3330     evaluating closed propositions to True/False using code generation:
  3331         method ``eval''
  3332 
  3333 Reasonable default setup of framework in HOL.
  3334 
  3335 Theorem attributs for selecting and transforming function equations theorems:
  3336 
  3337     [code fun]:        select a theorem as function equation for a specific constant
  3338     [code fun del]:    deselect a theorem as function equation for a specific constant
  3339     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3340     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3341 
  3342 User-defined serializations (target in {SML, OCaml, Haskell}):
  3343 
  3344     code_const <and-list of constants (term syntax)>
  3345       {(target) <and-list of const target syntax>}+
  3346 
  3347     code_type <and-list of type constructors>
  3348       {(target) <and-list of type target syntax>}+
  3349 
  3350     code_instance <and-list of instances>
  3351       {(target)}+
  3352         where instance ::= <type constructor> :: <class>
  3353 
  3354     code_class <and_list of classes>
  3355       {(target) <and-list of class target syntax>}+
  3356         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3357 
  3358 code_instance and code_class only are effective to target Haskell.
  3359 
  3360 For example usage see src/HOL/ex/Codegenerator.thy and
  3361 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3362 generation from Isabelle/HOL theories is available via "isatool doc
  3363 codegen".
  3364 
  3365 * Code generator: consts in 'consts_code' Isar commands are now
  3366 referred to by usual term syntax (including optional type
  3367 annotations).
  3368 
  3369 * Command 'no_translations' removes translation rules from theory
  3370 syntax.
  3371 
  3372 * Overloaded definitions are now actually checked for acyclic
  3373 dependencies.  The overloading scheme is slightly more general than
  3374 that of Haskell98, although Isabelle does not demand an exact
  3375 correspondence to type class and instance declarations.
  3376 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3377 exotic versions of overloading -- at the discretion of the user!
  3378 
  3379 Polymorphic constants are represented via type arguments, i.e. the
  3380 instantiation that matches an instance against the most general
  3381 declaration given in the signature.  For example, with the declaration
  3382 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3383 as c(nat).  Overloading is essentially simultaneous structural
  3384 recursion over such type arguments.  Incomplete specification patterns
  3385 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3386 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3387 Command 'print_theory' outputs the normalized system of recursive
  3388 equations, see section "definitions".
  3389 
  3390 * Configuration options are maintained within the theory or proof
  3391 context (with name and type bool/int/string), providing a very simple
  3392 interface to a poor-man's version of general context data.  Tools may
  3393 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3394 these values using Config.get etc.  Users may change options via an
  3395 associated attribute of the same name.  This form of context
  3396 declaration works particularly well with commands 'declare' or
  3397 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3398 very easy to avoid global references, which would not observe Isar
  3399 toplevel undo/redo and fail to work with multithreading.
  3400 
  3401 Various global ML references of Pure and HOL have been turned into
  3402 configuration options:
  3403 
  3404   Unify.search_bound		unify_search_bound
  3405   Unify.trace_bound		unify_trace_bound
  3406   Unify.trace_simp		unify_trace_simp
  3407   Unify.trace_types		unify_trace_types
  3408   Simplifier.simp_depth_limit	simp_depth_limit
  3409   Blast.depth_limit		blast_depth_limit
  3410   DatatypeProp.dtK		datatype_distinctness_limit
  3411   fast_arith_neq_limit  	fast_arith_neq_limit
  3412   fast_arith_split_limit	fast_arith_split_limit
  3413 
  3414 * Named collections of theorems may be easily installed as context
  3415 data using the functor NamedThmsFun (see also
  3416 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3417 attributes; there is also a toplevel print command.  This facility is
  3418 just a common case of general context data, which is the preferred way
  3419 for anything more complex than just a list of facts in canonical
  3420 order.
  3421 
  3422 * Isar: command 'declaration' augments a local theory by generic
  3423 declaration functions written in ML.  This enables arbitrary content
  3424 being added to the context, depending on a morphism that tells the
  3425 difference of the original declaration context wrt. the application
  3426 context encountered later on.
  3427 
  3428 * Isar: proper interfaces for simplification procedures.  Command
  3429 'simproc_setup' declares named simprocs (with match patterns, and body
  3430 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3431 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3432 
  3433 * Isar: an extra pair of brackets around attribute declarations
  3434 abbreviates a theorem reference involving an internal dummy fact,
  3435 which will be ignored later --- only the effect of the attribute on
  3436 the background context will persist.  This form of in-place
  3437 declarations is particularly useful with commands like 'declare' and
  3438 'using', for example ``have A using [[simproc a]] by simp''.
  3439 
  3440 * Isar: method "assumption" (and implicit closing of subproofs) now
  3441 takes simple non-atomic goal assumptions into account: after applying
  3442 an assumption as a rule the resulting subgoals are solved by atomic
  3443 assumption steps.  This is particularly useful to finish 'obtain'
  3444 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3445 without referring to the original premise "!!x. P x ==> thesis" in the
  3446 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3447 more permissive.
  3448 
  3449 * Isar: implicit use of prems from the Isar proof context is
  3450 considered a legacy feature.  Common applications like ``have A .''
  3451 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3452 referencing facts explicitly here improves readability and
  3453 maintainability of proof texts.
  3454 
  3455 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3456 the obtained context from the course of reasoning!  For example:
  3457 
  3458   assume "EX x y. A x & B y"   -- "any previous fact"
  3459   then guess x and y by clarify
  3460 
  3461 This technique is potentially adventurous, depending on the facts and
  3462 proof tools being involved here.
  3463 
  3464 * Isar: known facts from the proof context may be specified as literal
  3465 propositions, using ASCII back-quote syntax.  This works wherever
  3466 named facts used to be allowed so far, in proof commands, proof
  3467 methods, attributes etc.  Literal facts are retrieved from the context
  3468 according to unification of type and term parameters.  For example,
  3469 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3470 theorems in the current context, then these are valid literal facts:
  3471 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3472 
  3473 There is also a proof method "fact" which does the same composition
  3474 for explicit goal states, e.g. the following proof texts coincide with
  3475 certain special cases of literal facts:
  3476 
  3477   have "A" by fact                 ==  note `A`
  3478   have "A ==> B" by fact           ==  note `A ==> B`
  3479   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3480   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3481 
  3482 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3483 outer syntax.  Thus symbolic identifiers may be used without
  3484 additional white space in declarations like this: ``assume *: A''.
  3485 
  3486 * Isar: 'print_facts' prints all local facts of the current context,
  3487 both named and unnamed ones.
  3488 
  3489 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3490 
  3491   def x == "t" and y == "u"
  3492 
  3493 * Isar: added command 'unfolding', which is structurally similar to
  3494 'using', but affects both the goal state and facts by unfolding given
  3495 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3496 'unfolded' attribute may be replaced by first-class proof text.
  3497 
  3498 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3499 and command 'unfolding' now all support object-level equalities
  3500 (potentially conditional).  The underlying notion of rewrite rule is
  3501 analogous to the 'rule_format' attribute, but *not* that of the
  3502 Simplifier (which is usually more generous).
  3503 
  3504 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3505 premises of a theorem by n. Useful in conjunction with drule.
  3506 
  3507 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3508 method expression within a sandbox consisting of the first N
  3509 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3510 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3511 simplifies all new goals that emerge from applying rule foo to the
  3512 originally first one.
  3513 
  3514 * Isar: schematic goals are no longer restricted to higher-order
  3515 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3516 expected.
  3517 
  3518 * Isar: the conclusion of a long theorem statement is now either
  3519 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3520 (essentially a disjunction of cases with local parameters and
  3521 assumptions).  The latter allows to express general elimination rules
  3522 adequately; in this notation common elimination rules look like this:
  3523 
  3524   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3525     assumes "EX x. P x"
  3526     obtains x where "P x"
  3527 
  3528   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3529     assumes "A & B"
  3530     obtains A and B
  3531 
  3532   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3533     assumes "A | B"
  3534     obtains
  3535       A
  3536     | B
  3537 
  3538 The subsequent classical rules even refer to the formal "thesis"
  3539 explicitly:
  3540 
  3541   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3542     obtains "~ thesis"
  3543 
  3544   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3545     obtains "thesis ==> something"
  3546 
  3547 The actual proof of an 'obtains' statement is analogous to that of the
  3548 Isar proof element 'obtain', only that there may be several cases.
  3549 Optional case names may be specified in parentheses; these will be
  3550 available both in the present proof and as annotations in the
  3551 resulting rule, for later use with the 'cases' method (cf. attribute
  3552 case_names).
  3553 
  3554 * Isar: the assumptions of a long theorem statement are available as
  3555 "assms" fact in the proof context.  This is more appropriate than the
  3556 (historical) "prems", which refers to all assumptions of the current
  3557 context, including those from the target locale, proof body etc.
  3558 
  3559 * Isar: 'print_statement' prints theorems from the current theory or
  3560 proof context in long statement form, according to the syntax of a
  3561 top-level lemma.
  3562 
  3563 * Isar: 'obtain' takes an optional case name for the local context
  3564 introduction rule (default "that").
  3565 
  3566 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3567 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3568 to occur.
  3569 
  3570 * Pure: syntax "CONST name" produces a fully internalized constant
  3571 according to the current context.  This is particularly useful for
  3572 syntax translations that should refer to internal constant
  3573 representations independently of name spaces.
  3574 
  3575 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3576 instead of "FOO ". This allows multiple binder declarations to coexist
  3577 in the same context.  INCOMPATIBILITY.
  3578 
  3579 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3580 primitive that also works in a locale context (both for constants and
  3581 fixed variables). Type declaration and internal syntactic representation
  3582 of given constants retrieved from the context. Likewise, the
  3583 'no_notation' command allows to remove given syntax annotations from the
  3584 current context.
  3585 
  3586 * Isar/locales: new derived specification elements 'axiomatization',
  3587 'definition', 'abbreviation', which support type-inference, admit
  3588 object-level specifications (equality, equivalence).  See also the
  3589 isar-ref manual.  Examples:
  3590 
  3591   axiomatization
  3592     eq  (infix "===" 50) where
  3593     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3594 
  3595   definition "f x y = x + y + 1"
  3596   definition g where "g x = f x x"
  3597 
  3598   abbreviation
  3599     neq  (infix "=!=" 50) where
  3600     "x =!= y == ~ (x === y)"
  3601 
  3602 These specifications may be also used in a locale context.  Then the
  3603 constants being introduced depend on certain fixed parameters, and the
  3604 constant name is qualified by the locale base name.  An internal
  3605 abbreviation takes care for convenient input and output, making the
  3606 parameters implicit and using the original short name.  See also
  3607 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3608 entities from a monomorphic theory.
  3609 
  3610 Presently, abbreviations are only available 'in' a target locale, but
  3611 not inherited by general import expressions.  Also note that
  3612 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3613 'translations' in common applications.  The "no_abbrevs" print mode
  3614 prevents folding of abbreviations in term output.
  3615 
  3616 Concrete syntax is attached to specified constants in internal form,
  3617 independently of name spaces.  The parse tree representation is
  3618 slightly different -- use 'notation' instead of raw 'syntax', and
  3619 'translations' with explicit "CONST" markup to accommodate this.
  3620 
  3621 * Pure/Isar: unified syntax for new-style specification mechanisms
  3622 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3623 full type inference and dummy patterns ("_").  For example:
  3624 
  3625   definition "K x _ = x"
  3626 
  3627   inductive conj for A B
  3628   where "A ==> B ==> conj A B"
  3629 
  3630 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3631 the current context.  Print mode "no_abbrevs" prevents inversion of
  3632 abbreviations on output.
  3633 
  3634 * Isar/locales: improved parameter handling: use of locales "var" and
  3635 "struct" no longer necessary; - parameter renamings are no longer
  3636 required to be injective.  For example, this allows to define
  3637 endomorphisms as locale endom = homom mult mult h.
  3638 
  3639 * Isar/locales: changed the way locales with predicates are defined.
  3640 Instead of accumulating the specification, the imported expression is
  3641 now an interpretation.  INCOMPATIBILITY: different normal form of
  3642 locale expressions.  In particular, in interpretations of locales with
  3643 predicates, goals repesenting already interpreted fragments are not
  3644 removed automatically.  Use methods `intro_locales' and
  3645 `unfold_locales'; see below.
  3646 
  3647 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3648 provide backward reasoning on locales predicates.  The methods are
  3649 aware of interpretations and discharge corresponding goals.
  3650 `intro_locales' is less aggressive then `unfold_locales' and does not
  3651 unfold predicates to assumptions.
  3652 
  3653 * Isar/locales: the order in which locale fragments are accumulated
  3654 has changed.  This enables to override declarations from fragments due
  3655 to interpretations -- for example, unwanted simp rules.
  3656 
  3657 * Isar/locales: interpretation in theories and proof contexts has been
  3658 extended.  One may now specify (and prove) equations, which are
  3659 unfolded in interpreted theorems.  This is useful for replacing
  3660 defined concepts (constants depending on locale parameters) by
  3661 concepts already existing in the target context.  Example:
  3662 
  3663   interpretation partial_order ["op <= :: [int, int] => bool"]
  3664     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3665 
  3666 Typically, the constant `partial_order.less' is created by a
  3667 definition specification element in the context of locale
  3668 partial_order.
  3669 
  3670 * Method "induct": improved internal context management to support
  3671 local fixes and defines on-the-fly. Thus explicit meta-level
  3672 connectives !!  and ==> are rarely required anymore in inductive goals
  3673 (using object-logic connectives for this purpose has been long
  3674 obsolete anyway). Common proof patterns are explained in
  3675 src/HOL/Induct/Common_Patterns.thy, see also
  3676 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3677 examples.
  3678 
  3679 * Method "induct": improved handling of simultaneous goals. Instead of
  3680 introducing object-level conjunction, the statement is now split into
  3681 several conclusions, while the corresponding symbolic cases are nested
  3682 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3683 see src/HOL/Induct/Common_Patterns.thy, for example.
  3684 
  3685 * Method "induct": mutual induction rules are now specified as a list
  3686 of rule sharing the same induction cases. HOL packages usually provide
  3687 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3688 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3689 mutual induction rules differently, i.e. like this:
  3690 
  3691   (induct rule: foo_bar.inducts)
  3692   (induct set: foo bar)
  3693   (induct pred: foo bar)
  3694   (induct type: foo bar)
  3695 
  3696 The ML function ProjectRule.projections turns old-style rules into the
  3697 new format.
  3698 
  3699 * Method "coinduct": dual of induction, see
  3700 src/HOL/Library/Coinductive_List.thy for various examples.
  3701 
  3702 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3703 considered a legacy feature.
  3704 
  3705 * Attribute "symmetric" produces result with standardized schematic
  3706 variables (index 0).  Potential INCOMPATIBILITY.
  3707 
  3708 * Simplifier: by default the simplifier trace only shows top level
  3709 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3710 default. Thus there is less danger of being flooded by the trace. The
  3711 trace indicates where parts have been suppressed.
  3712   
  3713 * Provers/classical: removed obsolete classical version of elim_format
  3714 attribute; classical elim/dest rules are now treated uniformly when
  3715 manipulating the claset.
  3716 
  3717 * Provers/classical: stricter checks to ensure that supplied intro,
  3718 dest and elim rules are well-formed; dest and elim rules must have at
  3719 least one premise.
  3720 
  3721 * Provers/classical: attributes dest/elim/intro take an optional
  3722 weight argument for the rule (just as the Pure versions).  Weights are
  3723 ignored by automated tools, but determine the search order of single
  3724 rule steps.
  3725 
  3726 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3727 where the body does not mention the bound variable.  Note that dummy
  3728 patterns implicitly depend on their context of bounds, which makes
  3729 "{_. _}" match any set comprehension as expected.  Potential
  3730 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3731 constant "_idtdummy" in the binding position.
  3732 
  3733 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3734 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3735 for example "A -> B" => "Pi A (%_. B)".
  3736 
  3737 * Pure: 'class_deps' command visualizes the subclass relation, using
  3738 the graph browser tool.
  3739 
  3740 * Pure: 'print_theory' now suppresses certain internal declarations by
  3741 default; use '!' option for full details.
  3742 
  3743 
  3744 *** HOL ***
  3745 
  3746 * Method "metis" proves goals by applying the Metis general-purpose
  3747 resolution prover (see also http://gilith.com/software/metis/).
  3748 Examples are in the directory MetisExamples.  WARNING: the
  3749 Isabelle/HOL-Metis integration does not yet work properly with
  3750 multi-threading.
  3751   
  3752 * Command 'sledgehammer' invokes external automatic theorem provers as
  3753 background processes.  It generates calls to the "metis" method if
  3754 successful. These can be pasted into the proof.  Users do not have to
  3755 wait for the automatic provers to return.  WARNING: does not really
  3756 work with multi-threading.
  3757 
  3758 * New "auto_quickcheck" feature tests outermost goal statements for
  3759 potential counter-examples.  Controlled by ML references
  3760 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3761 5000 milliseconds).  Fails silently if statements is outside of
  3762 executable fragment, or any other codgenerator problem occurs.
  3763 
  3764 * New constant "undefined" with axiom "undefined x = undefined".
  3765 
  3766 * Added class "HOL.eq", allowing for code generation with polymorphic
  3767 equality.
  3768 
  3769 * Some renaming of class constants due to canonical name prefixing in
  3770 the new 'class' package:
  3771 
  3772     HOL.abs ~> HOL.abs_class.abs
  3773     HOL.divide ~> HOL.divide_class.divide
  3774     0 ~> HOL.zero_class.zero
  3775     1 ~> HOL.one_class.one
  3776     op + ~> HOL.plus_class.plus
  3777     op - ~> HOL.minus_class.minus
  3778     uminus ~> HOL.minus_class.uminus
  3779     op * ~> HOL.times_class.times
  3780     op < ~> HOL.ord_class.less
  3781     op <= > HOL.ord_class.less_eq
  3782     Nat.power ~> Power.power_class.power
  3783     Nat.size ~> Nat.size_class.size
  3784     Numeral.number_of ~> Numeral.number_class.number_of
  3785     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3786     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3787     Orderings.min ~> Orderings.ord_class.min
  3788     Orderings.max ~> Orderings.ord_class.max
  3789     Divides.op div ~> Divides.div_class.div
  3790     Divides.op mod ~> Divides.div_class.mod
  3791     Divides.op dvd ~> Divides.div_class.dvd
  3792 
  3793 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3794 
  3795 a) User-defined constants using any of the names "plus", "minus",
  3796 "times", "less" or "less_eq". The standard syntax translations for
  3797 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3798 names.
  3799 
  3800 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3801 INCOMPATIBILITY: use more specific names.
  3802 
  3803 c) Permutative equations (e.g. "a + b = b + a")
  3804 Since the change of names also changes the order of terms, permutative
  3805 rewrite rules may get applied in a different order. Experience shows
  3806 that this is rarely the case (only two adaptions in the whole Isabelle
  3807 distribution).  INCOMPATIBILITY: rewrite proofs
  3808 
  3809 d) ML code directly refering to constant names
  3810 This in general only affects hand-written proof tactics, simprocs and
  3811 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3812 Consider using @{const_name} antiquotation.
  3813 
  3814 * New class "default" with associated constant "default".
  3815 
  3816 * Function "sgn" is now overloaded and available on int, real, complex
  3817 (and other numeric types), using class "sgn".  Two possible defs of
  3818 sgn are given as equational assumptions in the classes sgn_if and
  3819 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3820 INCOMPATIBILITY.
  3821 
  3822 * Locale "partial_order" now unified with class "order" (cf. theory
  3823 Orderings), added parameter "less".  INCOMPATIBILITY.
  3824 
  3825 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3826 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3827 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3828 
  3829 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3830 changed order of proof goals in instance proofs.
  3831 
  3832 * The transitivity reasoner for partial and linear orders is set up
  3833 for classes "order" and "linorder".  Instances of the reasoner are available
  3834 in all contexts importing or interpreting the corresponding locales.
  3835 Method "order" invokes the reasoner separately; the reasoner
  3836 is also integrated with the Simplifier as a solver.  Diagnostic
  3837 command 'print_orders' shows the available instances of the reasoner
  3838 in the current context.
  3839 
  3840 * Localized monotonicity predicate in theory "Orderings"; integrated
  3841 lemmas max_of_mono and min_of_mono with this predicate.
  3842 INCOMPATIBILITY.
  3843 
  3844 * Formulation of theorem "dense" changed slightly due to integration
  3845 with new class dense_linear_order.
  3846 
  3847 * Uniform lattice theory development in HOL.
  3848 
  3849     constants "meet" and "join" now named "inf" and "sup"
  3850     constant "Meet" now named "Inf"
  3851 
  3852     classes "meet_semilorder" and "join_semilorder" now named
  3853       "lower_semilattice" and "upper_semilattice"
  3854     class "lorder" now named "lattice"
  3855     class "comp_lat" now named "complete_lattice"
  3856 
  3857     Instantiation of lattice classes allows explicit definitions
  3858     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3859 
  3860   INCOMPATIBILITY.  Theorem renames:
  3861 
  3862     meet_left_le            ~> inf_le1
  3863     meet_right_le           ~> inf_le2
  3864     join_left_le            ~> sup_ge1
  3865     join_right_le           ~> sup_ge2
  3866     meet_join_le            ~> inf_sup_ord
  3867     le_meetI                ~> le_infI
  3868     join_leI                ~> le_supI
  3869     le_meet                 ~> le_inf_iff
  3870     le_join                 ~> ge_sup_conv
  3871     meet_idempotent         ~> inf_idem
  3872     join_idempotent         ~> sup_idem
  3873     meet_comm               ~> inf_commute
  3874     join_comm               ~> sup_commute
  3875     meet_leI1               ~> le_infI1
  3876     meet_leI2               ~> le_infI2
  3877     le_joinI1               ~> le_supI1
  3878     le_joinI2               ~> le_supI2
  3879     meet_assoc              ~> inf_assoc
  3880     join_assoc              ~> sup_assoc
  3881     meet_left_comm          ~> inf_left_commute
  3882     meet_left_idempotent    ~> inf_left_idem
  3883     join_left_comm          ~> sup_left_commute
  3884     join_left_idempotent    ~> sup_left_idem
  3885     meet_aci                ~> inf_aci
  3886     join_aci                ~> sup_aci
  3887     le_def_meet             ~> le_iff_inf
  3888     le_def_join             ~> le_iff_sup
  3889     join_absorp2            ~> sup_absorb2
  3890     join_absorp1            ~> sup_absorb1
  3891     meet_absorp1            ~> inf_absorb1
  3892     meet_absorp2            ~> inf_absorb2
  3893     meet_join_absorp        ~> inf_sup_absorb
  3894     join_meet_absorp        ~> sup_inf_absorb
  3895     distrib_join_le         ~> distrib_sup_le
  3896     distrib_meet_le         ~> distrib_inf_le
  3897 
  3898     add_meet_distrib_left   ~> add_inf_distrib_left
  3899     add_join_distrib_left   ~> add_sup_distrib_left
  3900     is_join_neg_meet        ~> is_join_neg_inf
  3901     is_meet_neg_join        ~> is_meet_neg_sup
  3902     add_meet_distrib_right  ~> add_inf_distrib_right
  3903     add_join_distrib_right  ~> add_sup_distrib_right
  3904     add_meet_join_distribs  ~> add_sup_inf_distribs
  3905     join_eq_neg_meet        ~> sup_eq_neg_inf
  3906     meet_eq_neg_join        ~> inf_eq_neg_sup
  3907     add_eq_meet_join        ~> add_eq_inf_sup
  3908     meet_0_imp_0            ~> inf_0_imp_0
  3909     join_0_imp_0            ~> sup_0_imp_0
  3910     meet_0_eq_0             ~> inf_0_eq_0
  3911     join_0_eq_0             ~> sup_0_eq_0
  3912     neg_meet_eq_join        ~> neg_inf_eq_sup
  3913     neg_join_eq_meet        ~> neg_sup_eq_inf
  3914     join_eq_if              ~> sup_eq_if
  3915 
  3916     mono_meet               ~> mono_inf
  3917     mono_join               ~> mono_sup
  3918     meet_bool_eq            ~> inf_bool_eq
  3919     join_bool_eq            ~> sup_bool_eq
  3920     meet_fun_eq             ~> inf_fun_eq
  3921     join_fun_eq             ~> sup_fun_eq
  3922     meet_set_eq             ~> inf_set_eq
  3923     join_set_eq             ~> sup_set_eq
  3924     meet1_iff               ~> inf1_iff
  3925     meet2_iff               ~> inf2_iff
  3926     meet1I                  ~> inf1I
  3927     meet2I                  ~> inf2I
  3928     meet1D1                 ~> inf1D1
  3929     meet2D1                 ~> inf2D1
  3930     meet1D2                 ~> inf1D2
  3931     meet2D2                 ~> inf2D2
  3932     meet1E                  ~> inf1E
  3933     meet2E                  ~> inf2E
  3934     join1_iff               ~> sup1_iff
  3935     join2_iff               ~> sup2_iff
  3936     join1I1                 ~> sup1I1
  3937     join2I1                 ~> sup2I1
  3938     join1I1                 ~> sup1I1
  3939     join2I2                 ~> sup1I2
  3940     join1CI                 ~> sup1CI
  3941     join2CI                 ~> sup2CI
  3942     join1E                  ~> sup1E
  3943     join2E                  ~> sup2E
  3944 
  3945     is_meet_Meet            ~> is_meet_Inf
  3946     Meet_bool_def           ~> Inf_bool_def
  3947     Meet_fun_def            ~> Inf_fun_def
  3948     Meet_greatest           ~> Inf_greatest
  3949     Meet_lower              ~> Inf_lower
  3950     Meet_set_def            ~> Inf_set_def
  3951 
  3952     Sup_def                 ~> Sup_Inf
  3953     Sup_bool_eq             ~> Sup_bool_def
  3954     Sup_fun_eq              ~> Sup_fun_def
  3955     Sup_set_eq              ~> Sup_set_def
  3956 
  3957     listsp_meetI            ~> listsp_infI
  3958     listsp_meet_eq          ~> listsp_inf_eq
  3959 
  3960     meet_min                ~> inf_min
  3961     join_max                ~> sup_max
  3962 
  3963 * Added syntactic class "size"; overloaded constant "size" now has
  3964 type "'a::size ==> bool"
  3965 
  3966 * Internal reorganisation of `size' of datatypes: size theorems
  3967 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3968 simplification rules by default!); theorems "prod.size" now named
  3969 "*.size".
  3970 
  3971 * Class "div" now inherits from class "times" rather than "type".
  3972 INCOMPATIBILITY.
  3973 
  3974 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3975 Linorder etc.  have disappeared; operations defined in terms of
  3976 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3977 
  3978 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3979 
  3980 * HOL-Word: New extensive library and type for generic, fixed size
  3981 machine words, with arithemtic, bit-wise, shifting and rotating
  3982 operations, reflection into int, nat, and bool lists, automation for
  3983 linear arithmetic (by automatic reflection into nat or int), including
  3984 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3985 arithmetic type classes, supporting automatic simplification of
  3986 numerals on all operations.
  3987 
  3988 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3989 
  3990 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3991 
  3992 * Code generator library theories:
  3993   - Code_Integer represents HOL integers by big integer literals in target
  3994     languages.
  3995   - Code_Char represents HOL characters by character literals in target
  3996     languages.
  3997   - Code_Char_chr like Code_Char, but also offers treatment of character
  3998     codes; includes Code_Integer.
  3999   - Executable_Set allows to generate code for finite sets using lists.
  4000   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4001     denominator).
  4002   - Executable_Real implements a subset of real numbers, namly those
  4003     representable by rational numbers.
  4004   - Efficient_Nat implements natural numbers by integers, which in general will
  4005     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4006     includes Code_Integer.
  4007   - Code_Index provides an additional datatype index which is mapped to
  4008     target-language built-in integers.
  4009   - Code_Message provides an additional datatype message_string which is isomorphic to
  4010     strings; messages are mapped to target-language strings.
  4011 
  4012 * New package for inductive predicates
  4013 
  4014   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4015 
  4016     inductive
  4017       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4018       for z_1 :: U_1 and ... and z_n :: U_m
  4019     where
  4020       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4021     | ...
  4022 
  4023   with full support for type-inference, rather than
  4024 
  4025     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4026 
  4027     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4028     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4029 
  4030     inductive "s z_1 ... z_m"
  4031     intros
  4032       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4033       ...
  4034 
  4035   For backward compatibility, there is a wrapper allowing inductive
  4036   sets to be defined with the new package via
  4037 
  4038     inductive_set
  4039       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4040       for z_1 :: U_1 and ... and z_n :: U_m
  4041     where
  4042       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4043     | ...
  4044 
  4045   or
  4046 
  4047     inductive_set
  4048       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4049       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4050       for z_1 :: U_1 and ... and z_n :: U_m
  4051     where
  4052       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4053     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4054     | ...
  4055 
  4056   if the additional syntax "p ..." is required.
  4057 
  4058   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4059   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4060 
  4061   INCOMPATIBILITIES:
  4062 
  4063   - Since declaration and definition of inductive sets or predicates
  4064     is no longer separated, abbreviations involving the newly
  4065     introduced sets or predicates must be specified together with the
  4066     introduction rules after the 'where' keyword (see above), rather
  4067     than before the actual inductive definition.
  4068 
  4069   - The variables in induction and elimination rules are now
  4070     quantified in the order of their occurrence in the introduction
  4071     rules, rather than in alphabetical order. Since this may break
  4072     some proofs, these proofs either have to be repaired, e.g. by
  4073     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4074     statements of the form
  4075 
  4076       case (rule_i a_i_1 ... a_i_{k_i})
  4077 
  4078     or the old order of quantification has to be restored by explicitly adding
  4079     meta-level quantifiers in the introduction rules, i.e.
  4080 
  4081       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4082 
  4083   - The format of the elimination rules is now
  4084 
  4085       p z_1 ... z_m x_1 ... x_n ==>
  4086         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4087         ==> ... ==> P
  4088 
  4089     for predicates and
  4090 
  4091       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4092         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4093         ==> ... ==> P
  4094 
  4095     for sets rather than
  4096 
  4097       x : s z_1 ... z_m ==>
  4098         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4099         ==> ... ==> P
  4100 
  4101     This may require terms in goals to be expanded to n-tuples
  4102     (e.g. using case_tac or simplification with the split_paired_all
  4103     rule) before the above elimination rule is applicable.
  4104 
  4105   - The elimination or case analysis rules for (mutually) inductive
  4106     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4107     list of rules "p_1_..._p_k.elims" is no longer available.
  4108 
  4109 * New package "function"/"fun" for general recursive functions,
  4110 supporting mutual and nested recursion, definitions in local contexts,
  4111 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4112 for small examples, and the separate tutorial on the function
  4113 package. The old recdef "package" is still available as before, but
  4114 users are encouraged to use the new package.
  4115 
  4116 * Method "lexicographic_order" automatically synthesizes termination
  4117 relations as lexicographic combinations of size measures. 
  4118 
  4119 * Case-expressions allow arbitrary constructor-patterns (including
  4120 "_") and take their order into account, like in functional
  4121 programming.  Internally, this is translated into nested
  4122 case-expressions; missing cases are added and mapped to the predefined
  4123 constant "undefined". In complicated cases printing may no longer show
  4124 the original input but the internal form. Lambda-abstractions allow
  4125 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4126 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4127 variable.
  4128 
  4129 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4130 is an abbreviation for "of_nat :: nat => int". The simplification
  4131 rules for "of_nat" have been changed to work like "int" did
  4132 previously.  Potential INCOMPATIBILITY:
  4133   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4134   - of_nat_diff and of_nat_mult are no longer default simp rules
  4135 
  4136 * Method "algebra" solves polynomial equations over (semi)rings using
  4137 Groebner bases. The (semi)ring structure is defined by locales and the
  4138 tool setup depends on that generic context. Installing the method for
  4139 a specific type involves instantiating the locale and possibly adding
  4140 declarations for computation on the coefficients.  The method is
  4141 already instantiated for natural numbers and for the axiomatic class
  4142 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4143 CALCULEMUS 2007 for the general principles underlying this
  4144 architecture of context-aware proof-tools.
  4145 
  4146 * Method "ferrack" implements quantifier elimination over
  4147 special-purpose dense linear orders using locales (analogous to
  4148 "algebra"). The method is already installed for class
  4149 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4150 rat, etc.
  4151 
  4152 * Former constant "List.op @" now named "List.append".  Use ML
  4153 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4154 circumvent possible incompatibilities when working on ML level.
  4155 
  4156 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4157 
  4158 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4159 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4160 
  4161 * New syntax for Haskell-like list comprehension (input only), eg.
  4162 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4163 
  4164 * The special syntax for function "filter" has changed from [x :
  4165 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4166 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4167 
  4168 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4169 defined on nat only, as an abbreviation for [a..<Suc b]
  4170 INCOMPATIBILITY.
  4171 
  4172 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4173 
  4174 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4175 
  4176 * New lemma collection field_simps (an extension of ring_simps) for
  4177 manipulating (in)equations involving division. Multiplies with all
  4178 denominators that can be proved to be non-zero (in equations) or
  4179 positive/negative (in inequations).
  4180 
  4181 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4182 have been improved and renamed to ring_simps, group_simps and
  4183 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4184 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4185 
  4186 * Theory Library/Commutative_Ring: switched from recdef to function
  4187 package; constants add, mul, pow now curried.  Infix syntax for
  4188 algebraic operations.
  4189 
  4190 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4191 INCOMPATIBILITY.
  4192 
  4193 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4194 INCOMPATIBILITY.
  4195 
  4196 * HOL/records: generalised field-update to take a function on the
  4197 field rather than the new value: r(|A := x|) is translated to A_update
  4198 (K x) r The K-combinator that is internally used is called K_record.
  4199 INCOMPATIBILITY: Usage of the plain update functions has to be
  4200 adapted.
  4201  
  4202 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4203 * x = 0, which are required for a semiring.  Richer structures do not
  4204 inherit from semiring_0 anymore, because this property is a theorem
  4205 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4206 there is more to prove, but this is mostly trivial.
  4207 
  4208 * Class "recpower" is generalized to arbitrary monoids, not just
  4209 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4210 commutativity or semiring properties additionally.
  4211 
  4212 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4213 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4214 better use 'abbreviation'.
  4215 
  4216 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4217 
  4218 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4219 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4220 significant changes for setting up numeral syntax for types:
  4221   - New constants Numeral.pred and Numeral.succ instead
  4222       of former Numeral.bin_pred and Numeral.bin_succ.
  4223   - Use integer operations instead of bin_add, bin_mult and so on.
  4224   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4225   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4226 
  4227 See src/HOL/Integ/IntArith.thy for an example setup.
  4228 
  4229 * Command 'normal_form' computes the normal form of a term that may
  4230 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4231 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4232 heavy-duty computations because the functions are compiled to ML
  4233 first.  Correspondingly, a method "normalization" is provided.  See
  4234 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4235 
  4236 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4237 25 like -->); output depends on the "iff" print_mode, the default is
  4238 "A = B" (with priority 50).
  4239 
  4240 * Relations less (<) and less_eq (<=) are also available on type bool.
  4241 Modified syntax to disallow nesting without explicit parentheses,
  4242 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4243 INCOMPATIBILITY.
  4244 
  4245 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4246 
  4247 * Relation composition operator "op O" now has precedence 75 and binds
  4248 stronger than union and intersection. INCOMPATIBILITY.
  4249 
  4250 * The old set interval syntax "{m..n(}" (and relatives) has been
  4251 removed.  Use "{m..<n}" (and relatives) instead.
  4252 
  4253 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4254 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4255 ``declare [[simproc del: neq]]''.
  4256 
  4257 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4258 True/False.
  4259 
  4260 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4261 
  4262 * Theorem setsum_mult renamed to setsum_right_distrib.
  4263 
  4264 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4265 ``rule'' method.
  4266 
  4267 * Reimplemented methods "sat" and "satx", with several improvements:
  4268 goals no longer need to be stated as "<prems> ==> False", equivalences
  4269 (i.e. "=" on type bool) are handled, variable names of the form
  4270 "lit_<n>" are no longer reserved, significant speedup.
  4271 
  4272 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4273 zChaff is still supported as well.
  4274 
  4275 * 'inductive' and 'datatype': provide projections of mutual rules,
  4276 bundled as foo_bar.inducts;
  4277 
  4278 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4279 Library.
  4280 
  4281 * Library: moved theory Accessible_Part to main HOL.
  4282 
  4283 * Library: added theory Coinductive_List of potentially infinite lists
  4284 as greatest fixed-point.
  4285 
  4286 * Library: added theory AssocList which implements (finite) maps as
  4287 association lists.
  4288 
  4289 * Method "evaluation" solves goals (i.e. a boolean expression)
  4290 efficiently by compiling it to ML.  The goal is "proved" (via an
  4291 oracle) if it evaluates to True.
  4292 
  4293 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4294 also when invoked by the simplifier.  This results in the Simplifier
  4295 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4296 Configuration option fast_arith_split_limit=0 recovers the old
  4297 behavior.
  4298 
  4299 * Support for hex (0x20) and binary (0b1001) numerals.
  4300 
  4301 * New method: reify eqs (t), where eqs are equations for an
  4302 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4303 parameter, computes a term s::'b and a list xs::'a list and proves the
  4304 theorem I xs s = t. This is also known as reification or quoting. The
  4305 resulting theorem is applied to the subgoal to substitute t with I xs
  4306 s.  If t is omitted, the subgoal itself is reified.
  4307 
  4308 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4309 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4310 where f is supposed to be a computable function (in the sense of code
  4311 generattion). The method uses reify to compute s and xs as above then
  4312 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4313 r and finally gets the theorem t = r, which is again applied to the
  4314 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4315 
  4316 * Reflection: Automatic reification now handels binding, an example is
  4317 available in src/HOL/ex/ReflectionEx.thy
  4318 
  4319 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4320 command 'statespace' that is similar to 'record', but introduces an
  4321 abstract specification based on the locale infrastructure instead of
  4322 HOL types.  This leads to extra flexibility in composing state spaces,
  4323 in particular multiple inheritance and renaming of components.
  4324 
  4325 
  4326 *** HOL-Complex ***
  4327 
  4328 * Hyperreal: Functions root and sqrt are now defined on negative real
  4329 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4330 Nonnegativity side conditions have been removed from many lemmas, so
  4331 that more subgoals may now be solved by simplification; potential
  4332 INCOMPATIBILITY.
  4333 
  4334 * Real: new type classes formalize real normed vector spaces and
  4335 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4336 and norm :: 'a => real.
  4337 
  4338 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4339 reals into other types. The overloaded constant Reals :: 'a set is now
  4340 defined as range of_real; potential INCOMPATIBILITY.
  4341 
  4342 * Real: proper support for ML code generation, including 'quickcheck'.
  4343 Reals are implemented as arbitrary precision rationals.
  4344 
  4345 * Hyperreal: Several constants that previously worked only for the
  4346 reals have been generalized, so they now work over arbitrary vector
  4347 spaces. Type annotations may need to be added in some cases; potential
  4348 INCOMPATIBILITY.
  4349 
  4350   Infinitesimal  :: ('a::real_normed_vector) star set
  4351   HFinite        :: ('a::real_normed_vector) star set
  4352   HInfinite      :: ('a::real_normed_vector) star set
  4353   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4354   monad          :: ('a::real_normed_vector) star => 'a star set
  4355   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4356   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4357   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4358   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4359   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4360   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4361   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4362   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4363   sgn            :: 'a::real_normed_vector => 'a
  4364   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4365 
  4366 * Complex: Some complex-specific constants are now abbreviations for
  4367 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4368 hnorm.  Other constants have been entirely removed in favor of the
  4369 polymorphic versions (INCOMPATIBILITY):
  4370 
  4371   approx        <-- capprox
  4372   HFinite       <-- CFinite
  4373   HInfinite     <-- CInfinite
  4374   Infinitesimal <-- CInfinitesimal
  4375   monad         <-- cmonad
  4376   galaxy        <-- cgalaxy
  4377   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4378   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4379   (ns)deriv     <-- (ns)cderiv
  4380 
  4381 
  4382 *** HOL-Algebra ***
  4383 
  4384 * Formalisation of ideals and the quotient construction over rings.
  4385 
  4386 * Order and lattice theory no longer based on records.
  4387 INCOMPATIBILITY.
  4388 
  4389 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4390 greatest_closed.  INCOMPATIBILITY.
  4391 
  4392 * Method algebra is now set up via an attribute.  For examples see
  4393 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4394 of algebraic structures.
  4395 
  4396 * Renamed theory CRing to Ring.
  4397 
  4398 
  4399 *** HOL-Nominal ***
  4400 
  4401 * Substantial, yet incomplete support for nominal datatypes (binding
  4402 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4403 src/HOL/Nominal/Examples.  Prospective users should consult
  4404 http://isabelle.in.tum.de/nominal/
  4405 
  4406 
  4407 *** ML ***
  4408 
  4409 * ML basics: just one true type int, which coincides with IntInf.int
  4410 (even on SML/NJ).
  4411 
  4412 * ML within Isar: antiquotations allow to embed statically-checked
  4413 formal entities in the source, referring to the context available at
  4414 compile-time.  For example:
  4415 
  4416 ML {* @{sort "{zero,one}"} *}
  4417 ML {* @{typ "'a => 'b"} *}
  4418 ML {* @{term "%x. x"} *}
  4419 ML {* @{prop "x == y"} *}
  4420 ML {* @{ctyp "'a => 'b"} *}
  4421 ML {* @{cterm "%x. x"} *}
  4422 ML {* @{cprop "x == y"} *}
  4423 ML {* @{thm asm_rl} *}
  4424 ML {* @{thms asm_rl} *}
  4425 ML {* @{type_name c} *}
  4426 ML {* @{type_syntax c} *}
  4427 ML {* @{const_name c} *}
  4428 ML {* @{const_syntax c} *}
  4429 ML {* @{context} *}
  4430 ML {* @{theory} *}
  4431 ML {* @{theory Pure} *}
  4432 ML {* @{theory_ref} *}
  4433 ML {* @{theory_ref Pure} *}
  4434 ML {* @{simpset} *}
  4435 ML {* @{claset} *}
  4436 ML {* @{clasimpset} *}
  4437 
  4438 The same works for sources being ``used'' within an Isar context.
  4439 
  4440 * ML in Isar: improved error reporting; extra verbosity with
  4441 ML_Context.trace enabled.
  4442 
  4443 * Pure/General/table.ML: the join operations now works via exceptions
  4444 DUP/SAME instead of type option. This is simpler in simple cases, and
  4445 admits slightly more efficient complex applications.
  4446 
  4447 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4448 use Context.generic instead of just theory.
  4449 
  4450 * Pure: datatype Context.generic joins theory/Proof.context and
  4451 provides some facilities for code that works in either kind of
  4452 context, notably GenericDataFun for uniform theory and proof data.
  4453 
  4454 * Pure: simplified internal attribute type, which is now always
  4455 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4456 local (Proof.context) attributes have been discontinued, while
  4457 minimizing code duplication. Thm.rule_attribute and
  4458 Thm.declaration_attribute build canonical attributes; see also structure
  4459 Context for further operations on Context.generic, notably
  4460 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4461 declarations and definitions.
  4462 
  4463 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4464 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4465 init only required for impure data. INCOMPATIBILITY: empty really need
  4466 to be empty (no dependencies on theory content!)
  4467 
  4468 * Pure/kernel: consts certification ignores sort constraints given in
  4469 signature declarations. (This information is not relevant to the
  4470 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4471 potential INCOMPATIBILITY.
  4472 
  4473 * Pure: axiomatic type classes are now purely definitional, with
  4474 explicit proofs of class axioms and super class relations performed
  4475 internally. See Pure/axclass.ML for the main internal interfaces --
  4476 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4477 AxClass.axiomatize_class/classrel/arity supersede
  4478 Sign.add_classes/classrel/arities.
  4479 
  4480 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4481 global/local versions on theory vs. Proof.context have been
  4482 discontinued; Attrib.syntax and Method.syntax have been adapted
  4483 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4484 attributes, methods, etc.
  4485 
  4486 * Pure: several functions of signature "... -> theory -> theory * ..."
  4487 have been reoriented to "... -> theory -> ... * theory" in order to
  4488 allow natural usage in combination with the ||>, ||>>, |-> and
  4489 fold_map combinators.
  4490 
  4491 * Pure: official theorem names (closed derivations) and additional
  4492 comments (tags) are now strictly separate.  Name hints -- which are
  4493 maintained as tags -- may be attached any time without affecting the
  4494 derivation.
  4495 
  4496 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4497 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4498 achieve the old behaviour.
  4499 
  4500 * Pure: the "Goal" constant is now called "prop", supporting a
  4501 slightly more general idea of ``protecting'' meta-level rule
  4502 statements.
  4503 
  4504 * Pure: Logic.(un)varify only works in a global context, which is now
  4505 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4506 Logic.legacy_(un)varify as temporary workaround.
  4507 
  4508 * Pure: structure Name provides scalable operations for generating
  4509 internal variable names, notably Name.variants etc.  This replaces
  4510 some popular functions from term.ML:
  4511 
  4512   Term.variant		->  Name.variant
  4513   Term.variantlist	->  Name.variant_list
  4514   Term.invent_names	->  Name.invent_list
  4515 
  4516 Note that low-level renaming rarely occurs in new code -- operations
  4517 from structure Variable are used instead (see below).
  4518 
  4519 * Pure: structure Variable provides fundamental operations for proper
  4520 treatment of fixed/schematic variables in a context.  For example,
  4521 Variable.import introduces fixes for schematics of given facts and
  4522 Variable.export reverses the effect (up to renaming) -- this replaces
  4523 various freeze_thaw operations.
  4524 
  4525 * Pure: structure Goal provides simple interfaces for
  4526 init/conclude/finish and tactical prove operations (replacing former
  4527 Tactic.prove).  Goal.prove is the canonical way to prove results
  4528 within a given context; Goal.prove_global is a degraded version for
  4529 theory level goals, including a global Drule.standard.  Note that
  4530 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4531 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4532 in a locale context).
  4533 
  4534 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4535 and type checking (Syntax.check_term etc.), with common combinations
  4536 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4537 which are considered legacy and await removal.
  4538 
  4539 * Pure/Syntax: generic interfaces for type unchecking
  4540 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4541 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4542 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4543 available for convenience, but refer to the very same operations using
  4544 a mere theory instead of a full context.
  4545 
  4546 * Isar: simplified treatment of user-level errors, using exception
  4547 ERROR of string uniformly.  Function error now merely raises ERROR,
  4548 without any side effect on output channels.  The Isar toplevel takes
  4549 care of proper display of ERROR exceptions.  ML code may use plain
  4550 handle/can/try; cat_error may be used to concatenate errors like this:
  4551 
  4552   ... handle ERROR msg => cat_error msg "..."
  4553 
  4554 Toplevel ML code (run directly or through the Isar toplevel) may be
  4555 embedded into the Isar toplevel with exception display/debug like
  4556 this:
  4557 
  4558   Isar.toplevel (fn () => ...)
  4559 
  4560 INCOMPATIBILITY, removed special transform_error facilities, removed
  4561 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4562 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4563 -- use plain ERROR instead.
  4564 
  4565 * Isar: theory setup now has type (theory -> theory), instead of a
  4566 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4567 
  4568 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4569 ProofContext.debug/verbose flags.
  4570 
  4571 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4572 theory before entering a proof state.  Transactions now always see a
  4573 quasi-functional intermediate checkpoint, both in interactive and
  4574 batch mode.
  4575 
  4576 * Isar: simplified interfaces for outer syntax.  Renamed
  4577 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4578 OuterSyntax.add_parsers -- this functionality is now included in
  4579 OuterSyntax.command etc.  INCOMPATIBILITY.
  4580 
  4581 * Simplifier: the simpset of a running simplification process now
  4582 contains a proof context (cf. Simplifier.the_context), which is the
  4583 very context that the initial simpset has been retrieved from (by
  4584 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4585 (solver, looper etc.) may depend on arbitrary proof data.
  4586 
  4587 * Simplifier.inherit_context inherits the proof context (plus the
  4588 local bounds) of the current simplification process; any simproc
  4589 etc. that calls the Simplifier recursively should do this!  Removed
  4590 former Simplifier.inherit_bounds, which is already included here --
  4591 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4592 specify an explicit context using Simplifier.context/theory_context.
  4593 
  4594 * Simplifier/Classical Reasoner: more abstract interfaces
  4595 change_simpset/claset for modifying the simpset/claset reference of a
  4596 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4597 INCOMPATIBILITY.
  4598 
  4599 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4600 "Trueprop" etc.
  4601 
  4602 
  4603 *** System ***
  4604 
  4605 * settings: the default heap location within ISABELLE_HOME_USER now
  4606 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4607 Isabelle installations.
  4608 
  4609 * isabelle-process: option -S (secure mode) disables some critical
  4610 operations, notably runtime compilation and evaluation of ML source
  4611 code.
  4612 
  4613 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4614 
  4615 * Support for parallel execution, using native multicore support of
  4616 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4617 independent theories, according to the given theory header
  4618 specifications. The maximum number of worker threads is specified via
  4619 usedir option -M or the "max-threads" setting in Proof General. A
  4620 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4621 to 6 on a 8-core machine.  User-code needs to observe certain
  4622 guidelines for thread-safe programming, see appendix A in the Isar
  4623 Implementation manual.
  4624 
  4625 
  4626 
  4627 New in Isabelle2005 (October 2005)
  4628 ----------------------------------
  4629 
  4630 *** General ***
  4631 
  4632 * Theory headers: the new header syntax for Isar theories is
  4633 
  4634   theory <name>
  4635   imports <theory1> ... <theoryN>
  4636   uses <file1> ... <fileM>
  4637   begin
  4638 
  4639 where the 'uses' part is optional.  The previous syntax
  4640 
  4641   theory <name> = <theory1> + ... + <theoryN>:
  4642 
  4643 will disappear in the next release.  Use isatool fixheaders to convert
  4644 existing theory files.  Note that there is no change in ancient
  4645 non-Isar theories now, but these will disappear soon.
  4646 
  4647 * Theory loader: parent theories can now also be referred to via
  4648 relative and absolute paths.
  4649 
  4650 * Command 'find_theorems' searches for a list of criteria instead of a
  4651 list of constants. Known criteria are: intro, elim, dest, name:string,
  4652 simp:term, and any term. Criteria can be preceded by '-' to select
  4653 theorems that do not match. Intro, elim, dest select theorems that
  4654 match the current goal, name:s selects theorems whose fully qualified
  4655 name contain s, and simp:term selects all simplification rules whose
  4656 lhs match term.  Any other term is interpreted as pattern and selects
  4657 all theorems matching the pattern. Available in ProofGeneral under
  4658 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4659 
  4660   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4661 
  4662 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4663 matching the current goal as introduction rule and not having "HOL."
  4664 in their name (i.e. not being defined in theory HOL).
  4665 
  4666 * Command 'thms_containing' has been discontinued in favour of
  4667 'find_theorems'; INCOMPATIBILITY.
  4668 
  4669 * Communication with Proof General is now 8bit clean, which means that
  4670 Unicode text in UTF-8 encoding may be used within theory texts (both
  4671 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4672 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4673 
  4674   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4675   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4676 
  4677 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4678 Classical Reasoner.  Typical big applications run around 2 times
  4679 faster.
  4680 
  4681 
  4682 *** Document preparation ***
  4683 
  4684 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4685 of raw sources.  Only those symbols that do not require additional
  4686 LaTeX packages (depending on comments in isabellesym.sty) are
  4687 displayed properly, everything else is left verbatim.  isatool display
  4688 and isatool print are used as front ends (these are subject to the
  4689 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4690 
  4691 * Command tags control specific markup of certain regions of text,
  4692 notably folding and hiding.  Predefined tags include "theory" (for
  4693 theory begin and end), "proof" for proof commands, and "ML" for
  4694 commands involving ML code; the additional tags "visible" and
  4695 "invisible" are unused by default.  Users may give explicit tag
  4696 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4697 interpretation of tags is determined by the LaTeX job during document
  4698 preparation: see option -V of isatool usedir, or options -n and -t of
  4699 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4700 \isadroptag.
  4701 
  4702 Several document versions may be produced at the same time via isatool
  4703 usedir (the generated index.html will link all of them).  Typical
  4704 specifications include ''-V document=theory,proof,ML'' to present
  4705 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4706 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4707 these parts without any formal replacement text.  The Isabelle site
  4708 default settings produce ''document'' and ''outline'' versions as
  4709 specified above.
  4710 
  4711 * Several new antiquotations:
  4712 
  4713   @{term_type term} prints a term with its type annotated;
  4714 
  4715   @{typeof term} prints the type of a term;
  4716 
  4717   @{const const} is the same as @{term const}, but checks that the
  4718   argument is a known logical constant;
  4719 
  4720   @{term_style style term} and @{thm_style style thm} print a term or
  4721   theorem applying a "style" to it
  4722 
  4723   @{ML text}
  4724 
  4725 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4726 definitions, equations, inequations etc., 'concl' printing only the
  4727 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4728 to print the specified premise.  TermStyle.add_style provides an ML
  4729 interface for introducing further styles.  See also the "LaTeX Sugar"
  4730 document practical applications.  The ML antiquotation prints
  4731 type-checked ML expressions verbatim.
  4732 
  4733 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4734 and 'text' support optional locale specification '(in loc)', which
  4735 specifies the default context for interpreting antiquotations.  For
  4736 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4737 
  4738 * Option 'locale=NAME' of antiquotations specifies an alternative
  4739 context interpreting the subsequent argument.  For example: @{thm
  4740 [locale=lattice] inf_assoc}.
  4741 
  4742 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4743 a proof context.
  4744 
  4745 * Proper output of antiquotations for theory commands involving a
  4746 proof context (such as 'locale' or 'theorem (in loc) ...').
  4747 
  4748 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4749 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4750 
  4751 * isatool usedir: new option -C (default true) controls whether option
  4752 -D should include a copy of the original document directory; -C false
  4753 prevents unwanted effects such as copying of administrative CVS data.
  4754 
  4755 
  4756 *** Pure ***
  4757 
  4758 * Considerably improved version of 'constdefs' command.  Now performs
  4759 automatic type-inference of declared constants; additional support for
  4760 local structure declarations (cf. locales and HOL records), see also
  4761 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4762 sequential dependencies of definitions within a single 'constdefs'
  4763 section; moreover, the declared name needs to be an identifier.  If
  4764 all fails, consider to fall back on 'consts' and 'defs' separately.
  4765 
  4766 * Improved indexed syntax and implicit structures.  First of all,
  4767 indexed syntax provides a notational device for subscripted
  4768 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4769 expressions.  Secondly, in a local context with structure
  4770 declarations, number indexes \<^sub>n or the empty index (default
  4771 number 1) refer to a certain fixed variable implicitly; option
  4772 show_structs controls printing of implicit structures.  Typical
  4773 applications of these concepts involve record types and locales.
  4774 
  4775 * New command 'no_syntax' removes grammar declarations (and
  4776 translations) resulting from the given syntax specification, which is
  4777 interpreted in the same manner as for the 'syntax' command.
  4778 
  4779 * 'Advanced' translation functions (parse_translation etc.) may depend
  4780 on the signature of the theory context being presently used for
  4781 parsing/printing, see also isar-ref manual.
  4782 
  4783 * Improved 'oracle' command provides a type-safe interface to turn an
  4784 ML expression of type theory -> T -> term into a primitive rule of
  4785 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4786 is already included here); see also FOL/ex/IffExample.thy;
  4787 INCOMPATIBILITY.
  4788 
  4789 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4790 before); "cI" is no longer bound, use "c.intro" instead.
  4791 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4792 axclasses vs. locales.
  4793 
  4794 * Improved internal renaming of symbolic identifiers -- attach primes
  4795 instead of base 26 numbers.
  4796 
  4797 * New flag show_question_marks controls printing of leading question
  4798 marks in schematic variable names.
  4799 
  4800 * In schematic variable names, *any* symbol following \<^isub> or
  4801 \<^isup> is now treated as part of the base name.  For example, the
  4802 following works without printing of awkward ".0" indexes:
  4803 
  4804   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4805     by simp
  4806 
  4807 * Inner syntax includes (*(*nested*) comments*).
  4808 
  4809 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4810 annotations as "(00...)".
  4811 
  4812 * Clear separation of logical types and nonterminals, where the latter
  4813 may only occur in 'syntax' specifications or type abbreviations.
  4814 Before that distinction was only partially implemented via type class
  4815 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4816 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4817 exotic syntax specifications may require further adaption
  4818 (e.g. Cube/Cube.thy).
  4819 
  4820 * Removed obsolete type class "logic", use the top sort {} instead.
  4821 Note that non-logical types should be declared as 'nonterminals'
  4822 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4823 specifications.
  4824 
  4825 * Attributes 'induct' and 'cases': type or set names may now be
  4826 locally fixed variables as well.
  4827 
  4828 * Simplifier: can now control the depth to which conditional rewriting
  4829 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4830 Limit.
  4831 
  4832 * Simplifier: simplification procedures may now take the current
  4833 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4834 interface), which is very useful for calling the Simplifier
  4835 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4836 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4837 low-level mk_simproc no longer applies Logic.varify internally, to
  4838 allow for use in a context of fixed variables.
  4839 
  4840 * thin_tac now works even if the assumption being deleted contains !!
  4841 or ==>.  More generally, erule now works even if the major premise of
  4842 the elimination rule contains !! or ==>.
  4843 
  4844 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4845 
  4846 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4847 from Pure, which contains all common declarations already.  Both
  4848 theories are defined via plain Isabelle/Isar .thy files.
  4849 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4850 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4851 use isatool fixcpure to adapt your theory and ML sources.
  4852 
  4853 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4854 selections of theorems in named facts via index ranges.
  4855 
  4856 * 'print_theorems': in theory mode, really print the difference
  4857 wrt. the last state (works for interactive theory development only),
  4858 in proof mode print all local facts (cf. 'print_facts');
  4859 
  4860 * 'hide': option '(open)' hides only base names.
  4861 
  4862 * More efficient treatment of intermediate checkpoints in interactive
  4863 theory development.
  4864 
  4865 * Code generator is now invoked via code_module (incremental code
  4866 generation) and code_library (modular code generation, ML structures
  4867 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4868 must be quoted when used as identifiers.
  4869 
  4870 * New 'value' command for reading, evaluating and printing terms using
  4871 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4872 quoted when used as identifier.
  4873 
  4874 
  4875 *** Locales ***
  4876 
  4877 * New commands for the interpretation of locale expressions in
  4878 theories (1), locales (2) and proof contexts (3).  These generate
  4879 proof obligations from the expression specification.  After the
  4880 obligations have been discharged, theorems of the expression are added
  4881 to the theory, target locale or proof context.  The synopsis of the
  4882 commands is a follows:
  4883 
  4884   (1) interpretation expr inst
  4885   (2) interpretation target < expr
  4886   (3) interpret expr inst
  4887 
  4888 Interpretation in theories and proof contexts require a parameter
  4889 instantiation of terms from the current context.  This is applied to
  4890 specifications and theorems of the interpreted expression.
  4891 Interpretation in locales only permits parameter renaming through the
  4892 locale expression.  Interpretation is smart in that interpretations
  4893 that are active already do not occur in proof obligations, neither are
  4894 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4895 inspect active interpretations of a particular locale.  For details,
  4896 see the Isar Reference manual.  Examples can be found in
  4897 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4898 
  4899 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4900 'interpret' instead.
  4901 
  4902 * New context element 'constrains' for adding type constraints to
  4903 parameters.
  4904 
  4905 * Context expressions: renaming of parameters with syntax
  4906 redeclaration.
  4907 
  4908 * Locale declaration: 'includes' disallowed.
  4909 
  4910 * Proper static binding of attribute syntax -- i.e. types / terms /
  4911 facts mentioned as arguments are always those of the locale definition
  4912 context, independently of the context of later invocations.  Moreover,
  4913 locale operations (renaming and type / term instantiation) are applied
  4914 to attribute arguments as expected.
  4915 
  4916 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4917 actual attributes; rare situations may require Attrib.attribute to
  4918 embed those attributes into Attrib.src that lack concrete syntax.
  4919 Attribute implementations need to cooperate properly with the static
  4920 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4921 Attrib.XXX_thm etc. already do the right thing without further
  4922 intervention.  Only unusual applications -- such as "where" or "of"
  4923 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4924 on the context and the facts involved -- may have to assign parsed
  4925 values to argument tokens explicitly.
  4926 
  4927 * Changed parameter management in theorem generation for long goal
  4928 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4929 theorem statement in rare situations.
  4930 
  4931 * Locale inspection command 'print_locale' omits notes elements.  Use
  4932 'print_locale!' to have them included in the output.
  4933 
  4934 
  4935 *** Provers ***
  4936 
  4937 * Provers/hypsubst.ML: improved version of the subst method, for
  4938 single-step rewriting: it now works in bound variable contexts. New is
  4939 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4940 rewrite a different subterm than the original subst method, which is
  4941 still available as 'simplesubst'.
  4942 
  4943 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4944 and quasi orders.
  4945 
  4946 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4947 reflexive-transitive closure of relations.
  4948 
  4949 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4950 limit (previously hard-coded with a value of 20) user-definable.
  4951 
  4952 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4953 is peformed already.  Object-logics merely need to finish their
  4954 initial simpset configuration as before.  INCOMPATIBILITY.
  4955 
  4956 
  4957 *** HOL ***
  4958 
  4959 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4960 
  4961   syntax (epsilon)
  4962     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4963 
  4964 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4965 and x-symbol; use option '-m epsilon' to get it actually printed.
  4966 Moreover, the mathematically important symbolic identifier \<epsilon>
  4967 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4968 
  4969 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4970 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4971 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4972 support corresponding Isar calculations.
  4973 
  4974 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4975 instead of ":".
  4976 
  4977 * theory SetInterval: changed the syntax for open intervals:
  4978 
  4979   Old       New
  4980   {..n(}    {..<n}
  4981   {)n..}    {n<..}
  4982   {m..n(}   {m..<n}
  4983   {)m..n}   {m<..n}
  4984   {)m..n(}  {m<..<n}
  4985 
  4986 The old syntax is still supported but will disappear in the next
  4987 release.  For conversion use the following Emacs search and replace
  4988 patterns (these are not perfect but work quite well):
  4989 
  4990   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4991   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4992 
  4993 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4994 equalities in commutative rings; method 'algebra' provides a generic
  4995 interface.
  4996 
  4997 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4998 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4999 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5000 be a tuple pattern.
  5001 
  5002 Some new syntax forms are available:
  5003 
  5004   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5005   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5006   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5007   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5008 
  5009 The latter form "\<Sum>x < k. e" used to be based on a separate
  5010 function "Summation", which has been discontinued.
  5011 
  5012 * theory Finite_Set: in structured induction proofs, the insert case
  5013 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5014 (insert F x)'.
  5015 
  5016 * The 'refute' command has been extended to support a much larger
  5017 fragment of HOL, including axiomatic type classes, constdefs and
  5018 typedefs, inductive datatypes and recursion.
  5019 
  5020 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5021 Requires zChaff with proof generation to be installed.  See
  5022 HOL/ex/SAT_Examples.thy for examples.
  5023 
  5024 * Datatype induction via method 'induct' now preserves the name of the
  5025 induction variable. For example, when proving P(xs::'a list) by
  5026 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5027 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5028 in unstructured proof scripts.
  5029 
  5030 * Reworked implementation of records.  Improved scalability for
  5031 records with many fields, avoiding performance problems for type
  5032 inference. Records are no longer composed of nested field types, but
  5033 of nested extension types. Therefore the record type only grows linear
  5034 in the number of extensions and not in the number of fields.  The
  5035 top-level (users) view on records is preserved.  Potential
  5036 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5037 old record representation. The type generated for a record is called
  5038 <record_name>_ext_type.
  5039 
  5040 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5041 proofs triggered by a record definition or a simproc (if
  5042 quick_and_dirty is enabled).  Definitions of large records can take
  5043 quite long.
  5044 
  5045 New simproc record_upd_simproc for simplification of multiple record
  5046 updates enabled by default.  Moreover, trivial updates are also
  5047 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5048 occasionally, since simplification is more powerful by default.
  5049 
  5050 * typedef: proper support for polymorphic sets, which contain extra
  5051 type-variables in the term.
  5052 
  5053 * Simplifier: automatically reasons about transitivity chains
  5054 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5055 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5056 old proofs break occasionally as simplification may now solve more
  5057 goals than previously.
  5058 
  5059 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5060 present.  Works for all partial orders (class "order"), in particular
  5061 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5062 just like y <= x.
  5063 
  5064 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5065 bound variable or a constant then the let is unfolded.  Otherwise
  5066 first a is simplified to b, and then f b is simplified to g. If
  5067 possible we abstract b from g arriving at "let x = b in h x",
  5068 otherwise we unfold the let and arrive at g.  The simproc can be
  5069 enabled/disabled by the reference use_let_simproc.  Potential
  5070 INCOMPATIBILITY since simplification is more powerful by default.
  5071 
  5072 * Classical reasoning: the meson method now accepts theorems as arguments.
  5073 
  5074 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5075 jobs to provide advice on the provability of subgoals.
  5076 
  5077 * Theory OrderedGroup and Ring_and_Field: various additions and
  5078 improvements to faciliate calculations involving equalities and
  5079 inequalities.
  5080 
  5081 The following theorems have been eliminated or modified
  5082 (INCOMPATIBILITY):
  5083 
  5084   abs_eq             now named abs_of_nonneg
  5085   abs_of_ge_0        now named abs_of_nonneg
  5086   abs_minus_eq       now named abs_of_nonpos
  5087   imp_abs_id         now named abs_of_nonneg
  5088   imp_abs_neg_id     now named abs_of_nonpos
  5089   mult_pos           now named mult_pos_pos
  5090   mult_pos_le        now named mult_nonneg_nonneg
  5091   mult_pos_neg_le    now named mult_nonneg_nonpos
  5092   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5093   mult_neg           now named mult_neg_neg
  5094   mult_neg_le        now named mult_nonpos_nonpos
  5095 
  5096 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5097      
  5098      zero_le_square
  5099      not_square_less_zero 
  5100 
  5101   The following lemmas have been deleted from Real/RealPow:
  5102   
  5103      realpow_zero_zero
  5104      realpow_two
  5105      realpow_less
  5106      zero_le_power
  5107      realpow_two_le
  5108      abs_realpow_two
  5109      realpow_two_abs     
  5110 
  5111 * Theory Parity: added rules for simplifying exponents.
  5112 
  5113 * Theory List:
  5114 
  5115 The following theorems have been eliminated or modified
  5116 (INCOMPATIBILITY):
  5117 
  5118   list_all_Nil       now named list_all.simps(1)
  5119   list_all_Cons      now named list_all.simps(2)
  5120   list_all_conv      now named list_all_iff
  5121   set_mem_eq         now named mem_iff
  5122 
  5123 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5124 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5125 
  5126 
  5127 *** HOL-Complex ***
  5128 
  5129 * Theory RealDef: better support for embedding natural numbers and
  5130 integers in the reals.
  5131 
  5132 The following theorems have been eliminated or modified
  5133 (INCOMPATIBILITY):
  5134 
  5135   exp_ge_add_one_self  now requires no hypotheses
  5136   real_of_int_add      reversed direction of equality (use [symmetric])
  5137   real_of_int_minus    reversed direction of equality (use [symmetric])
  5138   real_of_int_diff     reversed direction of equality (use [symmetric])
  5139   real_of_int_mult     reversed direction of equality (use [symmetric])
  5140 
  5141 * Theory RComplete: expanded support for floor and ceiling functions.
  5142 
  5143 * Theory Ln is new, with properties of the natural logarithm
  5144 
  5145 * Hyperreal: There is a new type constructor "star" for making
  5146 nonstandard types.  The old type names are now type synonyms:
  5147 
  5148   hypreal = real star
  5149   hypnat = nat star
  5150   hcomplex = complex star
  5151 
  5152 * Hyperreal: Many groups of similarly-defined constants have been
  5153 replaced by polymorphic versions (INCOMPATIBILITY):
  5154 
  5155   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5156 
  5157   starset      <-- starsetNat, starsetC
  5158   *s*          <-- *sNat*, *sc*
  5159   starset_n    <-- starsetNat_n, starsetC_n
  5160   *sn*         <-- *sNatn*, *scn*
  5161   InternalSets <-- InternalNatSets, InternalCSets
  5162 
  5163   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5164   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5165   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5166   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5167   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5168 
  5169 * Hyperreal: Many type-specific theorems have been removed in favor of
  5170 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5171 
  5172   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5173   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5174   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5175   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5176   right_minus <-- hypreal_add_minus
  5177   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5178   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5179   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5180   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5181   mult_1_right <-- hcomplex_mult_one_right
  5182   mult_zero_left <-- hcomplex_mult_zero_left
  5183   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5184   right_distrib <-- hypnat_add_mult_distrib2
  5185   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5186   right_inverse <-- hypreal_mult_inverse
  5187   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5188   order_refl <-- {hypreal,hypnat}_le_refl
  5189   order_trans <-- {hypreal,hypnat}_le_trans
  5190   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5191   order_less_le <-- {hypreal,hypnat}_less_le
  5192   linorder_linear <-- {hypreal,hypnat}_le_linear
  5193   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5194   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5195   add_nonneg_nonneg <-- hypreal_le_add_order
  5196 
  5197 * Hyperreal: Separate theorems having to do with type-specific
  5198 versions of constants have been merged into theorems that apply to the
  5199 new polymorphic constants (INCOMPATIBILITY):
  5200 
  5201   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5202   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5203   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5204   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5205   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5206   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5207   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5208   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5209   STAR_diff <-- {STAR,STARC}_diff
  5210   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5211     STARC_hcomplex_of_complex}_image_subset
  5212   starset_n_Un <-- starset{Nat,C}_n_Un
  5213   starset_n_Int <-- starset{Nat,C}_n_Int
  5214   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5215   starset_n_diff <-- starset{Nat,C}_n_diff
  5216   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5217   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5218   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5219   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5220   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5221   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5222   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5223   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5224   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5225   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5226   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5227   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5228   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5229   starfun_diff <-- starfun{C,RC,CR}_diff
  5230   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5231   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5232   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5233   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5234   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5235   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5236   starfun_Id <-- starfunC_Id
  5237   starfun_approx <-- starfun{Nat,CR}_approx
  5238   starfun_capprox <-- starfun{C,RC}_capprox
  5239   starfun_abs <-- starfunNat_rabs
  5240   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5241   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5242   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5243   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5244   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5245   starfun_add_approx <-- starfunCR_add_approx
  5246   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5247   starfun_divide <-- starfun{C,CR,RC}_divide
  5248   starfun_n <-- starfun{Nat,C}_n
  5249   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5250   starfun_n_add <-- starfun{Nat,C}_n_add
  5251   starfun_n_add_minus <-- starfunNat_n_add_minus
  5252   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5253   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5254   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5255 
  5256   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5257   star_n_minus <-- {hypreal,hcomplex}_minus
  5258   star_n_diff <-- {hypreal,hcomplex}_diff
  5259   star_n_mult <-- {hypreal,hcomplex}_mult
  5260   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5261   star_n_le <-- {hypreal,hypnat}_le
  5262   star_n_less <-- {hypreal,hypnat}_less
  5263   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5264   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5265   star_n_abs <-- hypreal_hrabs
  5266   star_n_divide <-- hcomplex_divide
  5267 
  5268   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5269   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5270   star_of_diff <-- hypreal_of_real_diff
  5271   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5272   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5273   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5274   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5275   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5276   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5277   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5278   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5279   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5280   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5281   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5282   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5283   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5284   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5285   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5286   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5287   star_of_power <-- hypreal_of_real_power
  5288   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5289 
  5290 * Hyperreal: new method "transfer" that implements the transfer
  5291 principle of nonstandard analysis. With a subgoal that mentions
  5292 nonstandard types like "'a star", the command "apply transfer"
  5293 replaces it with an equivalent one that mentions only standard types.
  5294 To be successful, all free variables must have standard types; non-
  5295 standard variables must have explicit universal quantifiers.
  5296 
  5297 * Hyperreal: A theory of Taylor series.
  5298 
  5299 
  5300 *** HOLCF ***
  5301 
  5302 * Discontinued special version of 'constdefs' (which used to support
  5303 continuous functions) in favor of the general Pure one with full
  5304 type-inference.
  5305 
  5306 * New simplification procedure for solving continuity conditions; it
  5307 is much faster on terms with many nested lambda abstractions (cubic
  5308 instead of exponential time).
  5309 
  5310 * New syntax for domain package: selector names are now optional.
  5311 Parentheses should be omitted unless argument is lazy, for example:
  5312 
  5313   domain 'a stream = cons "'a" (lazy "'a stream")
  5314 
  5315 * New command 'fixrec' for defining recursive functions with pattern
  5316 matching; defining multiple functions with mutual recursion is also
  5317 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5318 sinr, or any data constructor defined by the domain package. The given
  5319 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5320 syntax and examples.
  5321 
  5322 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5323 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5324 but the proof obligation additionally includes an admissibility
  5325 requirement. The packages generate instances of class cpo or pcpo,
  5326 with continuity and strictness theorems for Rep and Abs.
  5327 
  5328 * HOLCF: Many theorems have been renamed according to a more standard naming
  5329 scheme (INCOMPATIBILITY):
  5330 
  5331   foo_inject:  "foo$x = foo$y ==> x = y"
  5332   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5333   foo_less:    "(foo$x << foo$y) = (x << y)"
  5334   foo_strict:  "foo$UU = UU"
  5335   foo_defined: "... ==> foo$x ~= UU"
  5336   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5337 
  5338 
  5339 *** ZF ***
  5340 
  5341 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5342 including the First Isomorphism Theorem (on quotienting by the kernel
  5343 of a homomorphism).
  5344 
  5345 * ZF/Simplifier: install second copy of type solver that actually
  5346 makes use of TC rules declared to Isar proof contexts (or locales);
  5347 the old version is still required for ML proof scripts.
  5348 
  5349 
  5350 *** Cube ***
  5351 
  5352 * Converted to Isar theory format; use locales instead of axiomatic
  5353 theories.
  5354 
  5355 
  5356 *** ML ***
  5357 
  5358 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5359 for ||>, ||>>, |>>,
  5360 
  5361 * Pure/library.ML no longer defines its own option datatype, but uses
  5362 that of the SML basis, which has constructors NONE and SOME instead of
  5363 None and Some, as well as exception Option.Option instead of OPTION.
  5364 The functions the, if_none, is_some, is_none have been adapted
  5365 accordingly, while Option.map replaces apsome.
  5366 
  5367 * Pure/library.ML: the exception LIST has been given up in favour of
  5368 the standard exceptions Empty and Subscript, as well as
  5369 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5370 superceded by the standard hd and tl functions etc.
  5371 
  5372 A number of basic list functions are no longer exported to the ML
  5373 toplevel, as they are variants of predefined functions.  The following
  5374 suggests how one can translate existing code:
  5375 
  5376     rev_append xs ys = List.revAppend (xs, ys)
  5377     nth_elem (i, xs) = List.nth (xs, i)
  5378     last_elem xs = List.last xs
  5379     flat xss = List.concat xss
  5380     seq fs = List.app fs
  5381     partition P xs = List.partition P xs
  5382     mapfilter f xs = List.mapPartial f xs
  5383 
  5384 * Pure/library.ML: several combinators for linear functional
  5385 transformations, notably reverse application and composition:
  5386 
  5387   x |> f                f #> g
  5388   (x, y) |-> f          f #-> g
  5389 
  5390 * Pure/library.ML: introduced/changed precedence of infix operators:
  5391 
  5392   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5393   infix 2 ?;
  5394   infix 3 o oo ooo oooo;
  5395   infix 4 ~~ upto downto;
  5396 
  5397 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5398 infix operators.
  5399 
  5400 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5401 fold_map support linear functional transformations and nesting.  For
  5402 example:
  5403 
  5404   fold f [x1, ..., xN] y =
  5405     y |> f x1 |> ... |> f xN
  5406 
  5407   (fold o fold) f [xs1, ..., xsN] y =
  5408     y |> fold f xs1 |> ... |> fold f xsN
  5409 
  5410   fold f [x1, ..., xN] =
  5411     f x1 #> ... #> f xN
  5412 
  5413   (fold o fold) f [xs1, ..., xsN] =
  5414     fold f xs1 #> ... #> fold f xsN
  5415 
  5416 * Pure/library.ML: the following selectors on type 'a option are
  5417 available:
  5418 
  5419   the:               'a option -> 'a  (*partial*)
  5420   these:             'a option -> 'a  where 'a = 'b list
  5421   the_default: 'a -> 'a option -> 'a
  5422   the_list:          'a option -> 'a list
  5423 
  5424 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5425 basic operations for association lists, following natural argument
  5426 order; moreover the explicit equality predicate passed here avoids
  5427 potentially expensive polymorphic runtime equality checks.
  5428 The old functions may be expressed as follows:
  5429 
  5430   assoc = uncurry (AList.lookup (op =))
  5431   assocs = these oo AList.lookup (op =)
  5432   overwrite = uncurry (AList.update (op =)) o swap
  5433 
  5434 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5435 
  5436   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5437   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5438 
  5439 replacing make_keylist and keyfilter (occassionally used)
  5440 Naive rewrites:
  5441 
  5442   make_keylist = AList.make
  5443   keyfilter = AList.find (op =)
  5444 
  5445 * eq_fst and eq_snd now take explicit equality parameter, thus
  5446   avoiding eqtypes. Naive rewrites:
  5447 
  5448     eq_fst = eq_fst (op =)
  5449     eq_snd = eq_snd (op =)
  5450 
  5451 * Removed deprecated apl and apr (rarely used).
  5452   Naive rewrites:
  5453 
  5454     apl (n, op) =>>= curry op n
  5455     apr (op, m) =>>= fn n => op (n, m)
  5456 
  5457 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5458 provides a reasonably efficient light-weight implementation of sets as
  5459 lists.
  5460 
  5461 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5462 few new operations; existing lookup and update are now curried to
  5463 follow natural argument order (for use with fold etc.);
  5464 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5465 
  5466 * Pure/General: output via the Isabelle channels of
  5467 writeln/warning/error etc. is now passed through Output.output, with a
  5468 hook for arbitrary transformations depending on the print_mode
  5469 (cf. Output.add_mode -- the first active mode that provides a output
  5470 function wins).  Already formatted output may be embedded into further
  5471 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5472 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5473 accommodate easy composition of diagnostic messages etc.  Programmers
  5474 rarely need to care about Output.output or Output.raw at all, with
  5475 some notable exceptions: Output.output is required when bypassing the
  5476 standard channels (writeln etc.), or in token translations to produce
  5477 properly formatted results; Output.raw is required when capturing
  5478 already output material that will eventually be presented to the user
  5479 a second time.  For the default print mode, both Output.output and
  5480 Output.raw have no effect.
  5481 
  5482 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5483 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5484 cumulative results are displayed at the end of a batch session.
  5485 
  5486 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5487 replaced by File.platform_path and File.shell_path (with appropriate
  5488 hooks).  This provides a clean interface for unusual systems where the
  5489 internal and external process view of file names are different.
  5490 
  5491 * Pure: more efficient orders for basic syntactic entities: added
  5492 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5493 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5494 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5495 orders now -- potential INCOMPATIBILITY for code that depends on a
  5496 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5497 Library.sort_strings on result).
  5498 
  5499 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5500 fold_types traverse types/terms from left to right, observing natural
  5501 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5502 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5503 
  5504 * Pure: name spaces have been refined, with significant changes of the
  5505 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5506 to extern(_table).  The plain name entry path is superceded by a
  5507 general 'naming' context, which also includes the 'policy' to produce
  5508 a fully qualified name and external accesses of a fully qualified
  5509 name; NameSpace.extend is superceded by context dependent
  5510 Sign.declare_name.  Several theory and proof context operations modify
  5511 the naming context.  Especially note Theory.restore_naming and
  5512 ProofContext.restore_naming to get back to a sane state; note that
  5513 Theory.add_path is no longer sufficient to recover from
  5514 Theory.absolute_path in particular.
  5515 
  5516 * Pure: new flags short_names (default false) and unique_names
  5517 (default true) for controlling output of qualified names.  If
  5518 short_names is set, names are printed unqualified.  If unique_names is
  5519 reset, the name prefix is reduced to the minimum required to achieve
  5520 the original result when interning again, even if there is an overlap
  5521 with earlier declarations.
  5522 
  5523 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5524 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5525 (useful for printing error messages).  INCOMPATIBILITY.
  5526 
  5527 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5528 Theory.theory are now identified, referring to the universal
  5529 Context.theory (see Pure/context.ML).  Actual signature and theory
  5530 content is managed as theory data.  The old code and interfaces were
  5531 spread over many files and structures; the new arrangement introduces
  5532 considerable INCOMPATIBILITY to gain more clarity:
  5533 
  5534   Context -- theory management operations (name, identity, inclusion,
  5535     parents, ancestors, merge, etc.), plus generic theory data;
  5536 
  5537   Sign -- logical signature and syntax operations (declaring consts,
  5538     types, etc.), plus certify/read for common entities;
  5539 
  5540   Theory -- logical theory operations (stating axioms, definitions,
  5541     oracles), plus a copy of logical signature operations (consts,
  5542     types, etc.); also a few basic management operations (Theory.copy,
  5543     Theory.merge, etc.)
  5544 
  5545 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5546 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5547 for convenience -- they merely return the theory.
  5548 
  5549 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5550 
  5551 * Pure: the Isar proof context type is already defined early in Pure
  5552 as Context.proof (note that ProofContext.context and Proof.context are
  5553 aliases, where the latter is the preferred name).  This enables other
  5554 Isabelle components to refer to that type even before Isar is present.
  5555 
  5556 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5557 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5558 any of these kinds.  For example, Sign.intern typeK is now
  5559 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5560 Theory.hide_types.  Also note that former
  5561 Theory.hide_classes/types/consts are now
  5562 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5563 internalize their arguments!  INCOMPATIBILITY.
  5564 
  5565 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5566 datatype thmref (with constructors Name and NameSelection) instead of
  5567 plain string -- INCOMPATIBILITY;
  5568 
  5569 * Pure: cases produced by proof methods specify options, where NONE
  5570 means to remove case bindings -- INCOMPATIBILITY in
  5571 (RAW_)METHOD_CASES.
  5572 
  5573 * Pure: the following operations retrieve axioms or theorems from a
  5574 theory node or theory hierarchy, respectively:
  5575 
  5576   Theory.axioms_of: theory -> (string * term) list
  5577   Theory.all_axioms_of: theory -> (string * term) list
  5578   PureThy.thms_of: theory -> (string * thm) list
  5579   PureThy.all_thms_of: theory -> (string * thm) list
  5580 
  5581 * Pure: print_tac now outputs the goal through the trace channel.
  5582 
  5583 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5584 Reference Toplevel.debug (default false) controls detailed printing
  5585 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5586 controls execution profiling -- set to 1 for time and 2 for space
  5587 (both increase the runtime).
  5588 
  5589 * Isar session: The initial use of ROOT.ML is now always timed,
  5590 i.e. the log will show the actual process times, in contrast to the
  5591 elapsed wall-clock time that the outer shell wrapper produces.
  5592 
  5593 * Simplifier: improved handling of bound variables (nameless
  5594 representation, avoid allocating new strings).  Simprocs that invoke
  5595 the Simplifier recursively should use Simplifier.inherit_bounds to
  5596 avoid local name clashes.  Failure to do so produces warnings
  5597 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5598 for further details.
  5599 
  5600 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5601 bindings for all theorems stored within a given theory; this may help
  5602 in porting non-Isar theories to Isar ones, while keeping ML proof
  5603 scripts for the time being.
  5604 
  5605 * ML operator HTML.with_charset specifies the charset begin used for
  5606 generated HTML files.  For example:
  5607 
  5608   HTML.with_charset "utf-8" use_thy "Hebrew";
  5609   HTML.with_charset "utf-8" use_thy "Chinese";
  5610 
  5611 
  5612 *** System ***
  5613 
  5614 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5615 isabelle, isatool etc.).
  5616 
  5617 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5618 isatool doc, isatool mkdir, display_drafts etc.).
  5619 
  5620 * isatool usedir: option -f allows specification of the ML file to be
  5621 used by Isabelle; default is ROOT.ML.
  5622 
  5623 * New isatool version outputs the version identifier of the Isabelle
  5624 distribution being used.
  5625 
  5626 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5627 (containing Boolean satisfiability problems) into Isabelle/HOL
  5628 theories.
  5629 
  5630 
  5631 
  5632 New in Isabelle2004 (April 2004)
  5633 --------------------------------
  5634 
  5635 *** General ***
  5636 
  5637 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5638   Replaces linorder.ML.
  5639 
  5640 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5641   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5642   (\<a>...\<z>), are now considered normal letters, and can therefore
  5643   be used anywhere where an ASCII letter (a...zA...Z) has until
  5644   now. COMPATIBILITY: This obviously changes the parsing of some
  5645   terms, especially where a symbol has been used as a binder, say
  5646   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5647   as an identifier.  Fix it by inserting a space around former
  5648   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5649   existing theory and ML files.
  5650 
  5651 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5652 
  5653 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5654   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5655   a normal (but invisible) letter. For multiple letter subscripts repeat
  5656   \<^isub> like this: x\<^isub>1\<^isub>2.
  5657 
  5658 * Pure: There are now sub-/superscripts that can span more than one
  5659   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5660   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5661   superscript. The new control characters are not identifier parts.
  5662 
  5663 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5664   content of "..." to the latex file instead of \isacntrl... . The "..."
  5665   may consist of any printable characters excluding the end bracket >.
  5666 
  5667 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5668   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5669   declare constants "final", which prevents their being given a definition
  5670   later.  It is useful for constants whose behaviour is fixed axiomatically
  5671   rather than definitionally, such as the meta-logic connectives.
  5672 
  5673 * Pure: 'instance' now handles general arities with general sorts
  5674   (i.e. intersections of classes),
  5675 
  5676 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5677   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5678   It can be changed to alter the colors/layout of generated pages.
  5679 
  5680 
  5681 *** Isar ***
  5682 
  5683 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5684   cut_tac, subgoal_tac and thin_tac:
  5685   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5686     locales are no longer forced to write Isar proof scripts.
  5687     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5688     emulations.
  5689   - INCOMPATIBILITY: names of variables to be instantiated may no
  5690     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5691     This is consistent with the instantiation attribute "where".
  5692 
  5693 * Attributes "where" and "of":
  5694   - Now take type variables of instantiated theorem into account when reading
  5695     the instantiation string.  This fixes a bug that caused instantiated
  5696     theorems to have too special types in some circumstances.
  5697   - "where" permits explicit instantiations of type variables.
  5698 
  5699 * Calculation commands "moreover" and "also" no longer interfere with
  5700   current facts ("this"), admitting arbitrary combinations with "then"
  5701   and derived forms.
  5702 
  5703 * Locales:
  5704   - Goal statements involving the context element "includes" no longer
  5705     generate theorems with internal delta predicates (those ending on
  5706     "_axioms") in the premise.
  5707     Resolve particular premise with <locale>.intro to obtain old form.
  5708   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5709     specification and "includes" elements in goal statement.
  5710   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5711     [intro?] and [elim?] (respectively) by default.
  5712   - Experimental command for instantiation of locales in proof contexts:
  5713         instantiate <label>[<attrs>]: <loc>
  5714     Instantiates locale <loc> and adds all its theorems to the current context
  5715     taking into account their attributes.  Label and attrs are optional
  5716     modifiers, like in theorem declarations.  If present, names of
  5717     instantiated theorems are qualified with <label>, and the attributes
  5718     <attrs> are applied after any attributes these theorems might have already.
  5719       If the locale has assumptions, a chained fact of the form
  5720     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5721     are derived.  The command does not support old-style locales declared
  5722     with "locale (open)".
  5723       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5724 
  5725 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5726   (Isar) contexts.
  5727 
  5728 
  5729 *** HOL ***
  5730 
  5731 * Proof import: new image HOL4 contains the imported library from
  5732   the HOL4 system with about 2500 theorems. It is imported by
  5733   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5734   can be used like any other Isabelle image.  See
  5735   HOL/Import/HOL/README for more information.
  5736 
  5737 * Simplifier:
  5738   - Much improved handling of linear and partial orders.
  5739     Reasoners for linear and partial orders are set up for type classes
  5740     "linorder" and "order" respectively, and are added to the default simpset
  5741     as solvers.  This means that the simplifier can build transitivity chains
  5742     to solve goals from the assumptions.
  5743   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5744     of blast or auto after simplification become unnecessary because the goal
  5745     is solved by simplification already.
  5746 
  5747 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5748     all proved in axiomatic type classes for semirings, rings and fields.
  5749 
  5750 * Numerics:
  5751   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5752     now formalized using the Ring_and_Field theory mentioned above.
  5753   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5754     than before, because now they are set up once in a generic manner.
  5755   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5756     Look for the general versions in Ring_and_Field (and Power if they concern
  5757     exponentiation).
  5758 
  5759 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5760 
  5761 * Records:
  5762   - Record types are now by default printed with their type abbreviation
  5763     instead of the list of all field types. This can be configured via
  5764     the reference "print_record_type_abbr".
  5765   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5766     (not enabled by default).
  5767   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5768     EX x. x = sel r to True (not enabled by default).
  5769   - Tactic "record_split_simp_tac" to split and simplify records added.
  5770 
  5771 * 'specification' command added, allowing for definition by
  5772   specification.  There is also an 'ax_specification' command that
  5773   introduces the new constants axiomatically.
  5774 
  5775 * arith(_tac) is now able to generate counterexamples for reals as well.
  5776 
  5777 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5778 
  5779 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5780   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5781 
  5782 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5783   matrix theory to linear programming.
  5784 
  5785 * Unions and Intersections:
  5786   The latex output syntax of UN and INT has been changed
  5787   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5788   i.e. the index formulae has become a subscript.
  5789   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5790 
  5791 * Unions and Intersections over Intervals:
  5792   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5793   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5794   like in normal math, and corresponding versions for < and for intersection.
  5795 
  5796 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5797   lexicographic dictonary ordering has been added as "lexord".
  5798 
  5799 * ML: the legacy theory structures Int and List have been removed. They had
  5800   conflicted with ML Basis Library structures having the same names.
  5801 
  5802 * 'refute' command added to search for (finite) countermodels.  Only works
  5803   for a fragment of HOL.  The installation of an external SAT solver is
  5804   highly recommended.  See "HOL/Refute.thy" for details.
  5805 
  5806 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5807   formulae under an assignment of free variables to random values.
  5808   In contrast to 'refute', it can deal with inductive datatypes,
  5809   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5810   for examples.
  5811 
  5812 
  5813 *** HOLCF ***
  5814 
  5815 * Streams now come with concatenation and are part of the HOLCF image
  5816 
  5817 
  5818 
  5819 New in Isabelle2003 (May 2003)
  5820 ------------------------------
  5821 
  5822 *** General ***
  5823 
  5824 * Provers/simplifier:
  5825 
  5826   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5827     Assumptions are now subject to complete mutual simplification,
  5828     not just from left to right. The simplifier now preserves
  5829     the order of assumptions.
  5830 
  5831     Potential INCOMPATIBILITY:
  5832 
  5833     -- simp sometimes diverges where the old version did
  5834        not, e.g. invoking simp on the goal
  5835 
  5836         [| P (f x); y = x; f x = f y |] ==> Q
  5837 
  5838        now gives rise to the infinite reduction sequence
  5839 
  5840         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5841 
  5842        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5843        kind of problem.
  5844 
  5845     -- Tactics combining classical reasoner and simplification (such as auto)
  5846        are also affected by this change, because many of them rely on
  5847        simp. They may sometimes diverge as well or yield a different numbers
  5848        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5849        in case of problems. Sometimes subsequent calls to the classical
  5850        reasoner will fail because a preceeding call to the simplifier too
  5851        eagerly simplified the goal, e.g. deleted redundant premises.
  5852 
  5853   - The simplifier trace now shows the names of the applied rewrite rules
  5854 
  5855   - You can limit the number of recursive invocations of the simplifier
  5856     during conditional rewriting (where the simplifie tries to solve the
  5857     conditions before applying the rewrite rule):
  5858     ML "simp_depth_limit := n"
  5859     where n is an integer. Thus you can force termination where previously
  5860     the simplifier would diverge.
  5861 
  5862   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5863 
  5864   - No longer aborts on failed congruence proof.  Instead, the
  5865     congruence is ignored.
  5866 
  5867 * Pure: New generic framework for extracting programs from constructive
  5868   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5869   as HOL/Extraction for some case studies.
  5870 
  5871 * Pure: The main goal of the proof state is no longer shown by default, only
  5872 the subgoals. This behaviour is controlled by a new flag.
  5873    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5874 (ML: Proof.show_main_goal).
  5875 
  5876 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5877 rules whose conclusion matches subgoal 1:
  5878       PG menu: Isabelle/Isar -> Show me -> matching rules
  5879 The rules are ordered by how closely they match the subgoal.
  5880 In particular, rules that solve a subgoal outright are displayed first
  5881 (or rather last, the way they are printed).
  5882 (ML: ProofGeneral.print_intros())
  5883 
  5884 * Pure: New flag trace_unify_fail causes unification to print
  5885 diagnostic information (PG: in trace buffer) when it fails. This is
  5886 useful for figuring out why single step proofs like rule, erule or
  5887 assumption failed.
  5888 
  5889 * Pure: Locale specifications now produce predicate definitions
  5890 according to the body of text (covering assumptions modulo local
  5891 definitions); predicate "loc_axioms" covers newly introduced text,
  5892 while "loc" is cumulative wrt. all included locale expressions; the
  5893 latter view is presented only on export into the global theory
  5894 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5895 on the old view without predicates;
  5896 
  5897 * Pure: predefined locales "var" and "struct" are useful for sharing
  5898 parameters (as in CASL, for example); just specify something like
  5899 ``var x + var y + struct M'' as import;
  5900 
  5901 * Pure: improved thms_containing: proper indexing of facts instead of
  5902 raw theorems; check validity of results wrt. current name space;
  5903 include local facts of proof configuration (also covers active
  5904 locales), cover fixed variables in index; may use "_" in term
  5905 specification; an optional limit for the number of printed facts may
  5906 be given (the default is 40);
  5907 
  5908 * Pure: disallow duplicate fact bindings within new-style theory files
  5909 (batch-mode only);
  5910 
  5911 * Provers: improved induct method: assumptions introduced by case
  5912 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5913 the goal statement); "foo" still refers to all facts collectively;
  5914 
  5915 * Provers: the function blast.overloaded has been removed: all constants
  5916 are regarded as potentially overloaded, which improves robustness in exchange
  5917 for slight decrease in efficiency;
  5918 
  5919 * Provers/linorder: New generic prover for transitivity reasoning over
  5920 linear orders.  Note: this prover is not efficient!
  5921 
  5922 * Isar: preview of problems to finish 'show' now produce an error
  5923 rather than just a warning (in interactive mode);
  5924 
  5925 
  5926 *** HOL ***
  5927 
  5928 * arith(_tac)
  5929 
  5930  - Produces a counter example if it cannot prove a goal.
  5931    Note that the counter example may be spurious if the goal is not a formula
  5932    of quantifier-free linear arithmetic.
  5933    In ProofGeneral the counter example appears in the trace buffer.
  5934 
  5935  - Knows about div k and mod k where k is a numeral of type nat or int.
  5936 
  5937  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5938    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5939    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5940 
  5941 * simp's arithmetic capabilities have been enhanced a bit: it now
  5942 takes ~= in premises into account (by performing a case split);
  5943 
  5944 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5945 are distributed over a sum of terms;
  5946 
  5947 * New tactic "trans_tac" and method "trans" instantiate
  5948 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5949 "<=", "<" and "=").
  5950 
  5951 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5952 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5953 
  5954 * 'typedef' command has new option "open" to suppress the set
  5955 definition;
  5956 
  5957 * functions Min and Max on finite sets have been introduced (theory
  5958 Finite_Set);
  5959 
  5960 * attribute [symmetric] now works for relations as well; it turns
  5961 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5962 
  5963 * induct over a !!-quantified statement (say !!x1..xn):
  5964   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5965 
  5966 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5967 %x. None. Warning: empty_def now refers to the previously hidden definition
  5968 of the empty set.
  5969 
  5970 * Algebra: formalization of classical algebra.  Intended as base for
  5971 any algebraic development in Isabelle.  Currently covers group theory
  5972 (up to Sylow's theorem) and ring theory (Universal Property of
  5973 Univariate Polynomials).  Contributions welcome;
  5974 
  5975 * GroupTheory: deleted, since its material has been moved to Algebra;
  5976 
  5977 * Complex: new directory of the complex numbers with numeric constants,
  5978 nonstandard complex numbers, and some complex analysis, standard and
  5979 nonstandard (Jacques Fleuriot);
  5980 
  5981 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5982 
  5983 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5984 Fleuriot);
  5985 
  5986 * Real/HahnBanach: updated and adapted to locales;
  5987 
  5988 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5989 Gray and Kramer);
  5990 
  5991 * UNITY: added the Meier-Sanders theory of progress sets;
  5992 
  5993 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5994 as abstract algorithms, instantiated to the JVM;
  5995 
  5996 * Bali: Java source language formalization. Type system, operational
  5997 semantics, axiomatic semantics. Supported language features:
  5998 classes, interfaces, objects,virtual methods, static methods,
  5999 static/instance fields, arrays, access modifiers, definite
  6000 assignment, exceptions.
  6001 
  6002 
  6003 *** ZF ***
  6004 
  6005 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6006 universe, etc.);
  6007 
  6008 * Main ZF: virtually all theories converted to new-style format;
  6009 
  6010 
  6011 *** ML ***
  6012 
  6013 * Pure: Tactic.prove provides sane interface for internal proofs;
  6014 omits the infamous "standard" operation, so this is more appropriate
  6015 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6016 
  6017 * Pure: improved error reporting of simprocs;
  6018 
  6019 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6020 up simprocs;
  6021 
  6022 
  6023 *** Document preparation ***
  6024 
  6025 * uses \par instead of \\ for line breaks in theory text. This may
  6026 shift some page breaks in large documents. To get the old behaviour
  6027 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6028 
  6029 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6030 other packages
  6031 
  6032 * \<euro> now needs package babel/greek instead of marvosym (which
  6033 broke \Rightarrow)
  6034 
  6035 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6036 textcomp package)
  6037 
  6038 
  6039 
  6040 New in Isabelle2002 (March 2002)
  6041 --------------------------------
  6042 
  6043 *** Document preparation ***
  6044 
  6045 * greatly simplified document preparation setup, including more
  6046 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6047 instructive isatool mkdir; users should basically be able to get
  6048 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6049 users may run a separate document processing stage manually like this:
  6050 "isatool usedir -D output HOL Test && isatool document Test/output";
  6051 
  6052 * theory dependency graph may now be incorporated into documents;
  6053 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6054 with \includegraphics of LaTeX;
  6055 
  6056 * proper spacing of consecutive markup elements, especially text
  6057 blocks after section headings;
  6058 
  6059 * support bold style (for single symbols only), input syntax is like
  6060 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6061 
  6062 * \<bullet> is now output as bold \cdot by default, which looks much
  6063 better in printed text;
  6064 
  6065 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6066 note that these symbols are currently unavailable in Proof General /
  6067 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6068 
  6069 * isatool latex no longer depends on changed TEXINPUTS, instead
  6070 isatool document copies the Isabelle style files to the target
  6071 location;
  6072 
  6073 
  6074 *** Isar ***
  6075 
  6076 * Pure/Provers: improved proof by cases and induction;
  6077   - 'case' command admits impromptu naming of parameters (such as
  6078     "case (Suc n)");
  6079   - 'induct' method divinates rule instantiation from the inductive
  6080     claim; no longer requires excessive ?P bindings for proper
  6081     instantiation of cases;
  6082   - 'induct' method properly enumerates all possibilities of set/type
  6083     rules; as a consequence facts may be also passed through *type*
  6084     rules without further ado;
  6085   - 'induct' method now derives symbolic cases from the *rulified*
  6086     rule (before it used to rulify cases stemming from the internal
  6087     atomized version); this means that the context of a non-atomic
  6088     statement becomes is included in the hypothesis, avoiding the
  6089     slightly cumbersome show "PROP ?case" form;
  6090   - 'induct' may now use elim-style induction rules without chaining
  6091     facts, using ``missing'' premises from the goal state; this allows
  6092     rules stemming from inductive sets to be applied in unstructured
  6093     scripts, while still benefitting from proper handling of non-atomic
  6094     statements; NB: major inductive premises need to be put first, all
  6095     the rest of the goal is passed through the induction;
  6096   - 'induct' proper support for mutual induction involving non-atomic
  6097     rule statements (uses the new concept of simultaneous goals, see
  6098     below);
  6099   - append all possible rule selections, but only use the first
  6100     success (no backtracking);
  6101   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6102   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6103   - added 'print_induct_rules' (covered by help item in recent Proof
  6104     General versions);
  6105   - moved induct/cases attributes to Pure, methods to Provers;
  6106   - generic method setup instantiated for FOL and HOL;
  6107 
  6108 * Pure: support multiple simultaneous goal statements, for example
  6109 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6110 meta-level mechanism, this acts as if several individual goals had
  6111 been stated separately; in particular common proof methods need to be
  6112 repeated in order to cover all claims; note that a single elimination
  6113 step is *not* sufficient to establish the two conjunctions, so this
  6114 fails:
  6115 
  6116   assume "A & B" then have A and B ..   (*".." fails*)
  6117 
  6118 better use "obtain" in situations as above; alternative refer to
  6119 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6120 
  6121 * Pure: proper integration with ``locales''; unlike the original
  6122 version by Florian Kammller, Isar locales package high-level proof
  6123 contexts rather than raw logical ones (e.g. we admit to include
  6124 attributes everywhere); operations on locales include merge and
  6125 rename; support for implicit arguments (``structures''); simultaneous
  6126 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6127 some examples;
  6128 
  6129 * Pure: the following commands have been ``localized'', supporting a
  6130 target locale specification "(in name)": 'lemma', 'theorem',
  6131 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6132 stored both within the locale and at the theory level (exported and
  6133 qualified by the locale name);
  6134 
  6135 * Pure: theory goals may now be specified in ``long'' form, with
  6136 ad-hoc contexts consisting of arbitrary locale elements. for example
  6137 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6138 definitions may be given, too); the result is a meta-level rule with
  6139 the context elements being discharged in the obvious way;
  6140 
  6141 * Pure: new proof command 'using' allows to augment currently used
  6142 facts after a goal statement ('using' is syntactically analogous to
  6143 'apply', but acts on the goal's facts only); this allows chained facts
  6144 to be separated into parts given before and after a claim, as in
  6145 ``from a and b have C using d and e <proof>'';
  6146 
  6147 * Pure: renamed "antecedent" case to "rule_context";
  6148 
  6149 * Pure: new 'judgment' command records explicit information about the
  6150 object-logic embedding (used by several tools internally); no longer
  6151 use hard-wired "Trueprop";
  6152 
  6153 * Pure: added 'corollary' command;
  6154 
  6155 * Pure: fixed 'token_translation' command;
  6156 
  6157 * Pure: removed obsolete 'exported' attribute;
  6158 
  6159 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6160 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6161 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6162 
  6163 * Pure: method 'atomize' presents local goal premises as object-level
  6164 statements (atomic meta-level propositions); setup controlled via
  6165 rewrite rules declarations of 'atomize' attribute; example
  6166 application: 'induct' method with proper rule statements in improper
  6167 proof *scripts*;
  6168 
  6169 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6170 now consider the syntactic context of assumptions, giving a better
  6171 chance to get type-inference of the arguments right (this is
  6172 especially important for locales);
  6173 
  6174 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6175 mode;
  6176 
  6177 * Pure/obtain: the formal conclusion "thesis", being marked as
  6178 ``internal'', may no longer be reference directly in the text;
  6179 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6180 situations;
  6181 
  6182 * Pure: generic 'sym' attribute which declares a rule both as pure
  6183 'elim?' and for the 'symmetric' operation;
  6184 
  6185 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6186 text; the fixed correlation with particular command syntax has been
  6187 discontinued;
  6188 
  6189 * Pure: new method 'rules' is particularly well-suited for proof
  6190 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6191 but often produces more compact proof terms with less detours;
  6192 
  6193 * Pure/Provers/classical: simplified integration with pure rule
  6194 attributes and methods; the classical "intro?/elim?/dest?"
  6195 declarations coincide with the pure ones; the "rule" method no longer
  6196 includes classically swapped intros; "intro" and "elim" methods no
  6197 longer pick rules from the context; also got rid of ML declarations
  6198 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6199 INCOMPATIBILITY;
  6200 
  6201 * Provers/classical: attribute 'swapped' produces classical inversions
  6202 of introduction rules;
  6203 
  6204 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6205 rules instead of full simplifier context; 'iff' attribute handles
  6206 conditional rules;
  6207 
  6208 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6209 
  6210 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6211 "(permissive)" option to recover old behavior;
  6212 
  6213 * HOL: 'inductive' no longer features separate (collective) attributes
  6214 for 'intros' (was found too confusing);
  6215 
  6216 * HOL: properly declared induction rules less_induct and
  6217 wf_induct_rule;
  6218 
  6219 
  6220 *** HOL ***
  6221 
  6222 * HOL: moved over to sane numeral syntax; the new policy is as
  6223 follows:
  6224 
  6225   - 0 and 1 are polymorphic constants, which are defined on any
  6226   numeric type (nat, int, real etc.);
  6227 
  6228   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6229   binary representation internally;
  6230 
  6231   - type nat has special constructor Suc, and generally prefers Suc 0
  6232   over 1::nat and Suc (Suc 0) over 2::nat;
  6233 
  6234 This change may cause significant problems of INCOMPATIBILITY; here
  6235 are some hints on converting existing sources:
  6236 
  6237   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6238   entities, so expressions involving "-" (unary or binary minus) need
  6239   to be spaced properly;
  6240 
  6241   - existing occurrences of "1" may need to be constraint "1::nat" or
  6242   even replaced by Suc 0; similar for old "2";
  6243 
  6244   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6245 
  6246   - remove all special provisions on numerals in proofs;
  6247 
  6248 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6249 representation (depends on bin_arith_simps in the default context);
  6250 
  6251 * HOL: symbolic syntax for x^2 (numeral 2);
  6252 
  6253 * HOL: the class of all HOL types is now called "type" rather than
  6254 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6255 in axclass/classes, instance/arities, and (usually rare) occurrences
  6256 in typings (of consts etc.); internally the class is called
  6257 "HOL.type", ML programs should refer to HOLogic.typeS;
  6258 
  6259 * HOL/record package improvements:
  6260   - new derived operations "fields" to build a partial record section,
  6261     "extend" to promote a fixed record to a record scheme, and
  6262     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6263     declared as simp by default;
  6264   - shared operations ("more", "fields", etc.) now need to be always
  6265     qualified) --- potential INCOMPATIBILITY;
  6266   - removed "make_scheme" operations (use "make" with "extend") --
  6267     INCOMPATIBILITY;
  6268   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6269   - provides cases/induct rules for use with corresponding Isar
  6270     methods (for concrete records, record schemes, concrete more
  6271     parts, and schematic more parts -- in that order);
  6272   - internal definitions directly based on a light-weight abstract
  6273     theory of product types over typedef rather than datatype;
  6274 
  6275 * HOL: generic code generator for generating executable ML code from
  6276 specifications; specific support for HOL constructs such as inductive
  6277 datatypes and sets, as well as recursive functions; can be invoked
  6278 via 'generate_code' theory section;
  6279 
  6280 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6281 
  6282 * HOL: consolidated and renamed several theories.  In particular:
  6283         Ord.thy has been absorbed into HOL.thy
  6284         String.thy has been absorbed into List.thy
  6285 
  6286 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6287 (beware of argument permutation!);
  6288 
  6289 * HOL: linorder_less_split superseded by linorder_cases;
  6290 
  6291 * HOL/List: "nodups" renamed to "distinct";
  6292 
  6293 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6294 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6295   - Ex_def has changed, now need to use some_eq_ex
  6296 
  6297 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6298 in this (rare) case use:
  6299 
  6300   delSWrapper "split_all_tac"
  6301   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6302 
  6303 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6304 MAY FAIL;
  6305 
  6306 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6307 Isabelle's type classes, ^ on functions and relations has too general
  6308 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6309 necessary to attach explicit type constraints;
  6310 
  6311 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6312 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6313 renamed accordingly (eg "compI" -> "rel_compI").
  6314 
  6315 * HOL: syntax translations now work properly with numerals and records
  6316 expressions;
  6317 
  6318 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6319 of "lam" -- INCOMPATIBILITY;
  6320 
  6321 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6322 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6323 renamed "Product_Type.unit";
  6324 
  6325 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6326 
  6327 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6328 the "cases" method);
  6329 
  6330 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6331 Florian Kammller);
  6332 
  6333 * HOL/IMP: updated and converted to new-style theory format; several
  6334 parts turned into readable document, with proper Isar proof texts and
  6335 some explanations (by Gerwin Klein);
  6336 
  6337 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6338 
  6339 * HOL-Hyperreal is now a logic image;
  6340 
  6341 
  6342 *** HOLCF ***
  6343 
  6344 * Isar: consts/constdefs supports mixfix syntax for continuous
  6345 operations;
  6346 
  6347 * Isar: domain package adapted to new-style theory format, e.g. see
  6348 HOLCF/ex/Dnat.thy;
  6349 
  6350 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6351 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6352 lift.induct_tac, always use UU instead of Undef;
  6353 
  6354 * HOLCF/IMP: updated and converted to new-style theory;
  6355 
  6356 
  6357 *** ZF ***
  6358 
  6359 * Isar: proper integration of logic-specific tools and packages,
  6360 including theory commands '(co)inductive', '(co)datatype',
  6361 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6362 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6363 
  6364 * theory Main no longer includes AC; for the Axiom of Choice, base
  6365 your theory on Main_ZFC;
  6366 
  6367 * the integer library now covers quotients and remainders, with many
  6368 laws relating division to addition, multiplication, etc.;
  6369 
  6370 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6371 typeless version of the formalism;
  6372 
  6373 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6374 format;
  6375 
  6376 * ZF/Induct: new directory for examples of inductive definitions,
  6377 including theory Multiset for multiset orderings; converted to
  6378 new-style theory format;
  6379 
  6380 * ZF: many new theorems about lists, ordinals, etc.;
  6381 
  6382 
  6383 *** General ***
  6384 
  6385 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6386 variable proof controls level of detail: 0 = no proofs (only oracle
  6387 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6388 also ref manual for further ML interfaces;
  6389 
  6390 * Pure/axclass: removed obsolete ML interface
  6391 goal_subclass/goal_arity;
  6392 
  6393 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6394 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6395 separate tokens, so expressions involving minus need to be spaced
  6396 properly;
  6397 
  6398 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6399 rather than "infixl" or "infixr";
  6400 
  6401 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6402 sort constraint specifications in type inference; e.g. "x::_::foo"
  6403 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6404 type variable);
  6405 
  6406 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6407 control output of nested => (types); the default behavior is
  6408 "type_brackets";
  6409 
  6410 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6411 tokens into AST constants;
  6412 
  6413 * Pure/syntax: prefer later declarations of translations and print
  6414 translation functions; potential INCOMPATIBILITY: need to reverse
  6415 multiple declarations for same syntax element constant;
  6416 
  6417 * Pure/show_hyps reset by default (in accordance to existing Isar
  6418 practice);
  6419 
  6420 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6421 addSafter;
  6422 
  6423 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6424 as well;
  6425 
  6426 * system: tested support for MacOS X; should be able to get Isabelle +
  6427 Proof General to work in a plain Terminal after installing Poly/ML
  6428 (e.g. from the Isabelle distribution area) and GNU bash alone
  6429 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6430 support requires further installations, e.g. from
  6431 http://fink.sourceforge.net/);
  6432 
  6433 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6434 
  6435 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6436 of 40 MB), cf. ML_OPTIONS;
  6437 
  6438 * system: Proof General keywords specification is now part of the
  6439 Isabelle distribution (see etc/isar-keywords.el);
  6440 
  6441 * system: support for persistent Proof General sessions (refrain from
  6442 outdating all loaded theories on startup); user may create writable
  6443 logic images like this: ``isabelle -q HOL Test'';
  6444 
  6445 * system: smart selection of Isabelle process versus Isabelle
  6446 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6447 run both "isabelle" and "Isabelle" even if file names are badly
  6448 damaged (executable inspects the case of the first letter of its own
  6449 name); added separate "isabelle-process" and "isabelle-interface";
  6450 
  6451 * system: refrain from any attempt at filtering input streams; no
  6452 longer support ``8bit'' encoding of old isabelle font, instead proper
  6453 iso-latin characters may now be used; the related isatools
  6454 "symbolinput" and "nonascii" have disappeared as well;
  6455 
  6456 * system: removed old "xterm" interface (the print modes "xterm" and
  6457 "xterm_color" are still available for direct use in a suitable
  6458 terminal);
  6459 
  6460 
  6461 
  6462 New in Isabelle99-2 (February 2001)
  6463 -----------------------------------
  6464 
  6465 *** Overview of INCOMPATIBILITIES ***
  6466 
  6467 * HOL: please note that theories in the Library and elsewhere often use the
  6468 new-style (Isar) format; to refer to their theorems in an ML script you must
  6469 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6470 
  6471 * HOL: inductive package no longer splits induction rule aggressively,
  6472 but only as far as specified by the introductions given; the old
  6473 format may be recovered via ML function complete_split_rule or attribute
  6474 'split_rule (complete)';
  6475 
  6476 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6477 gfp_Tarski to gfp_unfold;
  6478 
  6479 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6480 
  6481 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6482 relation); infix "^^" has been renamed "``"; infix "``" has been
  6483 renamed "`"; "univalent" has been renamed "single_valued";
  6484 
  6485 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6486 operation;
  6487 
  6488 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6489 
  6490 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6491 
  6492 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6493 consequence, it is no longer monotonic wrt. the local goal context
  6494 (which is now passed through the inductive cases);
  6495 
  6496 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6497 \<gg> to \<ggreater>;
  6498 
  6499 
  6500 *** Document preparation ***
  6501 
  6502 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6503 available: are "it" for near math-mode best-style output, "sl" for
  6504 slanted text style, and "tt" for plain type-writer; if no
  6505 \isabellestyle command is given, output is according to slanted
  6506 type-writer);
  6507 
  6508 * support sub/super scripts (for single symbols only), input syntax is
  6509 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6510 
  6511 * some more standard symbols; see Appendix A of the system manual for
  6512 the complete list of symbols defined in isabellesym.sty;
  6513 
  6514 * improved isabelle style files; more abstract symbol implementation
  6515 (should now use \isamath{...} and \isatext{...} in custom symbol
  6516 definitions);
  6517 
  6518 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6519 state; Note that presentation of goal states does not conform to
  6520 actual human-readable proof documents.  Please do not include goal
  6521 states into document output unless you really know what you are doing!
  6522 
  6523 * proper indentation of antiquoted output with proportional LaTeX
  6524 fonts;
  6525 
  6526 * no_document ML operator temporarily disables LaTeX document
  6527 generation;
  6528 
  6529 * isatool unsymbolize tunes sources for plain ASCII communication;
  6530 
  6531 
  6532 *** Isar ***
  6533 
  6534 * Pure: Isar now suffers initial goal statements to contain unbound
  6535 schematic variables (this does not conform to actual readable proof
  6536 documents, due to unpredictable outcome and non-compositional proof
  6537 checking); users who know what they are doing may use schematic goals
  6538 for Prolog-style synthesis of proven results;
  6539 
  6540 * Pure: assumption method (an implicit finishing) now handles actual
  6541 rules as well;
  6542 
  6543 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6544 initial goal, declare "that" only as Pure intro (only for single
  6545 steps); the "that" rule assumption may now be involved in implicit
  6546 finishing, thus ".." becomes a feasible for trivial obtains;
  6547 
  6548 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6549 instance proofs may be performed by "..";
  6550 
  6551 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6552 statements as well;
  6553 
  6554 * Pure: more robust selection of calculational rules;
  6555 
  6556 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6557 rule (as well as the assumption rule);
  6558 
  6559 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6560 lemmas, using the graph browser tool;
  6561 
  6562 * Pure: predict failure of "show" in interactive mode;
  6563 
  6564 * Pure: 'thms_containing' now takes actual terms as arguments;
  6565 
  6566 * HOL: improved method 'induct' --- now handles non-atomic goals
  6567 (potential INCOMPATIBILITY); tuned error handling;
  6568 
  6569 * HOL: cases and induct rules now provide explicit hints about the
  6570 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6571 any remaining facts are inserted into the goal verbatim;
  6572 
  6573 * HOL: local contexts (aka cases) may now contain term bindings as
  6574 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6575 the result to be shown in each case;
  6576 
  6577 * HOL: added 'recdef_tc' command;
  6578 
  6579 * isatool convert assists in eliminating legacy ML scripts;
  6580 
  6581 
  6582 *** HOL ***
  6583 
  6584 * HOL/Library: a collection of generic theories to be used together
  6585 with main HOL; the theory loader path already includes this directory
  6586 by default; the following existing theories have been moved here:
  6587 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6588 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6589 
  6590 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6591 modelling and verification task performed in Isabelle/HOL +
  6592 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6593 
  6594 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6595 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6596 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6597 'domain', this makes the theory consistent with mathematical
  6598 literature;
  6599 
  6600 * HOL basics: added overloaded operations "inverse" and "divide"
  6601 (infix "/"), syntax for generic "abs" operation, generic summation
  6602 operator \<Sum>;
  6603 
  6604 * HOL/typedef: simplified package, provide more useful rules (see also
  6605 HOL/subset.thy);
  6606 
  6607 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6608 now expressed as a proper nested rule (old-style tactic scripts may
  6609 require atomize_strip_tac to cope with non-atomic premises);
  6610 
  6611 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6612 to "split_conv" (old name still available for compatibility);
  6613 
  6614 * HOL: improved concrete syntax for strings (e.g. allows translation
  6615 rules with string literals);
  6616 
  6617 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6618  and Fleuriot's mechanization of analysis, including the transcendental
  6619  functions for the reals;
  6620 
  6621 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6622 
  6623 
  6624 *** CTT ***
  6625 
  6626 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6627 "lam" is displayed as TWO lambda-symbols
  6628 
  6629 * CTT: theory Main now available, containing everything (that is, Bool
  6630 and Arith);
  6631 
  6632 
  6633 *** General ***
  6634 
  6635 * Pure: the Simplifier has been implemented properly as a derived rule
  6636 outside of the actual kernel (at last!); the overall performance
  6637 penalty in practical applications is about 50%, while reliability of
  6638 the Isabelle inference kernel has been greatly improved;
  6639 
  6640 * print modes "brackets" and "no_brackets" control output of nested =>
  6641 (types) and ==> (props); the default behaviour is "brackets";
  6642 
  6643 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6644 as assumptions as well;
  6645 
  6646 * system: support Poly/ML 4.0;
  6647 
  6648 * system: isatool install handles KDE version 1 or 2;
  6649 
  6650 
  6651 
  6652 New in Isabelle99-1 (October 2000)
  6653 ----------------------------------
  6654 
  6655 *** Overview of INCOMPATIBILITIES ***
  6656 
  6657 * HOL: simplification of natural numbers is much changed; to partly
  6658 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6659 issue the following ML commands:
  6660 
  6661   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6662   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6663 
  6664 * HOL: simplification no longer dives into case-expressions; this is
  6665 controlled by "t.weak_case_cong" for each datatype t;
  6666 
  6667 * HOL: nat_less_induct renamed to less_induct;
  6668 
  6669 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6670 fixsome to patch .thy and .ML sources automatically;
  6671 
  6672   select_equality  -> some_equality
  6673   select_eq_Ex     -> some_eq_ex
  6674   selectI2EX       -> someI2_ex
  6675   selectI2         -> someI2
  6676   selectI          -> someI
  6677   select1_equality -> some1_equality
  6678   Eps_sym_eq       -> some_sym_eq_trivial
  6679   Eps_eq           -> some_eq_trivial
  6680 
  6681 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6682 
  6683 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6684 instead);
  6685 
  6686 * HOL: the recursion equations generated by 'recdef' are now called
  6687 f.simps instead of f.rules;
  6688 
  6689 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6690 
  6691 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6692 sometimes be needed;
  6693 
  6694 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6695 
  6696 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6697 
  6698 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6699 product is now "<*>" instead of "Times"; the lexicographic product is
  6700 now "<*lex*>" instead of "**";
  6701 
  6702 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6703 of main HOL, but was unused); better use HOL's datatype package;
  6704 
  6705 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6706 the old syntax may be recovered as follows:
  6707 
  6708   syntax (symbols)
  6709     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6710       (infixl "\\<oplus>" 100)
  6711 
  6712 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6713 
  6714 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6715 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6716 internally;
  6717 
  6718 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6719 changed from A/r to A//r;
  6720 
  6721 * ZF: new treatment of arithmetic (nat & int) may break some old
  6722 proofs;
  6723 
  6724 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6725 rulify -> rule_format, elimify -> elim_format, ...);
  6726 
  6727 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6728 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6729 should have to change intro!! to intro? only); replaced "delrule" by
  6730 "rule del";
  6731 
  6732 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6733 
  6734 * Provers: strengthened force_tac by using new first_best_tac;
  6735 
  6736 * LaTeX document preparation: several changes of isabelle.sty (see
  6737 lib/texinputs);
  6738 
  6739 
  6740 *** Document preparation ***
  6741 
  6742 * formal comments (text blocks etc.) in new-style theories may now
  6743 contain antiquotations of thm/prop/term/typ/text to be presented
  6744 according to latex print mode; concrete syntax is like this:
  6745 @{term[show_types] "f(x) = a + x"};
  6746 
  6747 * isatool mkdir provides easy setup of Isabelle session directories,
  6748 including proper document sources;
  6749 
  6750 * generated LaTeX sources are now deleted after successful run
  6751 (isatool document -c); may retain a copy somewhere else via -D option
  6752 of isatool usedir;
  6753 
  6754 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6755 style files, achieving self-contained LaTeX sources and simplifying
  6756 LaTeX debugging;
  6757 
  6758 * old-style theories now produce (crude) LaTeX output as well;
  6759 
  6760 * browser info session directories are now self-contained (may be put
  6761 on WWW server seperately); improved graphs of nested sessions; removed
  6762 graph for 'all sessions';
  6763 
  6764 * several improvements in isabelle style files; \isabellestyle{it}
  6765 produces fake math mode output; \isamarkupheader is now \section by
  6766 default; see lib/texinputs/isabelle.sty etc.;
  6767 
  6768 
  6769 *** Isar ***
  6770 
  6771 * Isar/Pure: local results and corresponding term bindings are now
  6772 subject to Hindley-Milner polymorphism (similar to ML); this
  6773 accommodates incremental type-inference very nicely;
  6774 
  6775 * Isar/Pure: new derived language element 'obtain' supports
  6776 generalized existence reasoning;
  6777 
  6778 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6779 support accumulation of results, without applying any rules yet;
  6780 useful to collect intermediate results without explicit name
  6781 references, and for use with transitivity rules with more than 2
  6782 premises;
  6783 
  6784 * Isar/Pure: scalable support for case-analysis type proofs: new
  6785 'case' language element refers to local contexts symbolically, as
  6786 produced by certain proof methods; internally, case names are attached
  6787 to theorems as "tags";
  6788 
  6789 * Isar/Pure: theory command 'hide' removes declarations from
  6790 class/type/const name spaces;
  6791 
  6792 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6793 indicate potential overloading;
  6794 
  6795 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6796 
  6797 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6798 "{a,b,c}" instead of {a,b,c};
  6799 
  6800 * Isar/Pure now provides its own version of intro/elim/dest
  6801 attributes; useful for building new logics, but beware of confusion
  6802 with the version in Provers/classical;
  6803 
  6804 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6805 case name 'antecedent';
  6806 
  6807 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6808 to the current context is now done automatically);
  6809 
  6810 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6811 for definining proof methods in ML;
  6812 
  6813 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6814 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6815 most cases, one should have to change intro!! to intro? only);
  6816 replaced "delrule" by "rule del";
  6817 
  6818 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6819 'symmetric' attribute (the latter supercedes [RS sym]);
  6820 
  6821 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6822 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6823 well (including splits);
  6824 
  6825 * Isar/Provers: Simplifier and Classical methods now support all kind
  6826 of modifiers used in the past, including 'cong', 'iff', etc.
  6827 
  6828 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6829 of Simplifier and Classical reasoner);
  6830 
  6831 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6832 now support named cases; major packages (inductive, datatype, primrec,
  6833 recdef) support case names and properly name parameters;
  6834 
  6835 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6836 monotonicity conditions are extracted to be proven at end of
  6837 calculations;
  6838 
  6839 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6840 method anyway;
  6841 
  6842 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6843 split_if split_if_asm; datatype package provides theorems foo.splits =
  6844 foo.split foo.split_asm for each datatype;
  6845 
  6846 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6847 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6848 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6849 use "(cases (simplified))" method in proper proof texts);
  6850 
  6851 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6852 
  6853 * Isar: names of theorems etc. may be natural numbers as well;
  6854 
  6855 * Isar: 'pr' command: optional arguments for goals_limit and
  6856 ProofContext.prems_limit; no longer prints theory contexts, but only
  6857 proof states;
  6858 
  6859 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6860 additional print modes to be specified; e.g. "pr(latex)" will print
  6861 proof state according to the Isabelle LaTeX style;
  6862 
  6863 * Isar: improved support for emulating tactic scripts, including proof
  6864 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6865 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6866 (for HOL datatypes);
  6867 
  6868 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6869 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6870 'proof method scripts' have to be in depth-first order;
  6871 
  6872 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6873 
  6874 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6875 should instead use individual commands for printing items
  6876 (print_commands, print_methods etc.);
  6877 
  6878 * Isar: added 'nothing' --- the empty list of theorems;
  6879 
  6880 
  6881 *** HOL ***
  6882 
  6883 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6884 corresponding virtual machine and a specification of its bytecode
  6885 verifier and a lightweight bytecode verifier, including proofs of
  6886 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6887 Cornelia Pusch (see also the homepage of project Bali at
  6888 http://isabelle.in.tum.de/Bali/);
  6889 
  6890 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6891 Clemens Ballarin;
  6892 
  6893 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6894 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6895 Rasmussen;
  6896 
  6897 * HOL/Lattice: fundamental concepts of lattice theory and order
  6898 structures, including duals, properties of bounds versus algebraic
  6899 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6900 Theorem for complete lattices etc.; may also serve as a demonstration
  6901 for abstract algebraic reasoning using axiomatic type classes, and
  6902 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6903 
  6904 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6905 von Oheimb;
  6906 
  6907 * HOL/IMPP: extension of IMP with local variables and mutually
  6908 recursive procedures, by David von Oheimb;
  6909 
  6910 * HOL/Lambda: converted into new-style theory and document;
  6911 
  6912 * HOL/ex/Multiquote: example of multiple nested quotations and
  6913 anti-quotations -- basically a generalized version of de-Bruijn
  6914 representation; very useful in avoiding lifting of operations;
  6915 
  6916 * HOL/record: added general record equality rule to simpset; fixed
  6917 select-update simplification procedure to handle extended records as
  6918 well; admit "r" as field name;
  6919 
  6920 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6921 other numeric types and also as the identity of groups, rings, etc.;
  6922 
  6923 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6924 Types nat and int belong to this axclass;
  6925 
  6926 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6927    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6928    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6929   two terms #m*u and #n*u are replaced by #(m+n)*u
  6930     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6931   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6932     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6933 
  6934 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6935 powerful prover for predicate logic but knows nothing of clasets; see
  6936 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6937 
  6938 * HOL: new version of "case_tac" subsumes both boolean case split and
  6939 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6940 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6941 
  6942 * HOL: simplification no longer dives into case-expressions: only the
  6943 selector expression is simplified, but not the remaining arms; to
  6944 enable full simplification of case-expressions for datatype t, you may
  6945 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6946 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6947 
  6948 * HOL/recdef: the recursion equations generated by 'recdef' for
  6949 function 'f' are now called f.simps instead of f.rules; if all
  6950 termination conditions are proved automatically, these simplification
  6951 rules are added to the simpset, as in primrec; rules may be named
  6952 individually as well, resulting in a separate list of theorems for
  6953 each equation;
  6954 
  6955 * HOL/While is a new theory that provides a while-combinator. It
  6956 permits the definition of tail-recursive functions without the
  6957 provision of a termination measure. The latter is necessary once the
  6958 invariant proof rule for while is applied.
  6959 
  6960 * HOL: new (overloaded) notation for the set of elements below/above
  6961 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6962 
  6963 * HOL: theorems impI, allI, ballI bound as "strip";
  6964 
  6965 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6966 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6967 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6968 
  6969 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6970 
  6971 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6972 main HOL, but was unused);
  6973 
  6974 * HOL: fewer consts declared as global (e.g. have to refer to
  6975 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6976 
  6977 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6978 in case of overlap with user translations (e.g. judgements over
  6979 tuples); (note that the underlying logical represenation is still
  6980 bogus);
  6981 
  6982 
  6983 *** ZF ***
  6984 
  6985 * ZF: simplification automatically cancels common terms in arithmetic
  6986 expressions over nat and int;
  6987 
  6988 * ZF: new treatment of nat to minimize type-checking: all operators
  6989 coerce their operands to a natural number using the function natify,
  6990 making the algebraic laws unconditional;
  6991 
  6992 * ZF: as above, for int: operators coerce their operands to an integer
  6993 using the function intify;
  6994 
  6995 * ZF: the integer library now contains many of the usual laws for the
  6996 orderings, including $<=, and monotonicity laws for $+ and $*;
  6997 
  6998 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6999 simplification;
  7000 
  7001 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7002 to the simplifier and classical reasoner simultaneously;
  7003 
  7004 
  7005 *** General ***
  7006 
  7007 * Provers: blast_tac now handles actual object-logic rules as
  7008 assumptions; note that auto_tac uses blast_tac internally as well;
  7009 
  7010 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7011 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7012 
  7013 * Provers: delrules now handles destruct rules as well (no longer need
  7014 explicit make_elim);
  7015 
  7016 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7017   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7018 use instead the strong form,
  7019   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7020 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7021 from destruct-rules;
  7022 
  7023 * Provers: Simplifier.easy_setup provides a fast path to basic
  7024 Simplifier setup for new object-logics;
  7025 
  7026 * Pure: AST translation rules no longer require constant head on LHS;
  7027 
  7028 * Pure: improved name spaces: ambiguous output is qualified; support
  7029 for hiding of names;
  7030 
  7031 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7032 XSYMBOL_HOME; no longer need to do manual configuration in most
  7033 situations;
  7034 
  7035 * system: compression of ML heaps images may now be controlled via -c
  7036 option of isabelle and isatool usedir (currently only observed by
  7037 Poly/ML);
  7038 
  7039 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7040 useful for remote X11);
  7041 
  7042 * system: provide TAGS file for Isabelle sources;
  7043 
  7044 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7045 order;
  7046 
  7047 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7048 timing flag supersedes proof_timing and Toplevel.trace;
  7049 
  7050 * ML: new combinators |>> and |>>> for incremental transformations
  7051 with secondary results (e.g. certain theory extensions):
  7052 
  7053 * ML: PureThy.add_defs gets additional argument to indicate potential
  7054 overloading (usually false);
  7055 
  7056 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7057 results;
  7058 
  7059 
  7060 
  7061 New in Isabelle99 (October 1999)
  7062 --------------------------------
  7063 
  7064 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7065 
  7066 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7067 are no longer simplified.  (This allows the simplifier to unfold recursive
  7068 functional programs.)  To restore the old behaviour, declare
  7069 
  7070     Delcongs [if_weak_cong];
  7071 
  7072 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7073 complement;
  7074 
  7075 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7076 
  7077 * HOL/datatype: mutual_induct_tac no longer exists --
  7078   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7079 
  7080 * HOL/typedef: fixed type inference for representing set; type
  7081 arguments now have to occur explicitly on the rhs as type constraints;
  7082 
  7083 * ZF: The con_defs part of an inductive definition may no longer refer
  7084 to constants declared in the same theory;
  7085 
  7086 * HOL, ZF: the function mk_cases, generated by the inductive
  7087 definition package, has lost an argument.  To simplify its result, it
  7088 uses the default simpset instead of a supplied list of theorems.
  7089 
  7090 * HOL/List: the constructors of type list are now Nil and Cons;
  7091 
  7092 * Simplifier: the type of the infix ML functions
  7093         setSSolver addSSolver setSolver addSolver
  7094 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7095 for packaging solvers. A solver is created via
  7096         mk_solver: string -> (thm list -> int -> tactic) -> solver
  7097 where the string argument is only a comment.
  7098 
  7099 
  7100 *** Proof tools ***
  7101 
  7102 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7103 decision procedure for linear arithmetic. Currently it is used for
  7104 types `nat', `int', and `real' in HOL (see below); it can, should and
  7105 will be instantiated for other types and logics as well.
  7106 
  7107 * The simplifier now accepts rewrite rules with flexible heads, eg
  7108      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7109   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7110   matching.
  7111 
  7112 
  7113 *** General ***
  7114 
  7115 * New Isabelle/Isar subsystem provides an alternative to traditional
  7116 tactical theorem proving; together with the ProofGeneral/isar user
  7117 interface it offers an interactive environment for developing human
  7118 readable proof documents (Isar == Intelligible semi-automated
  7119 reasoning); for further information see isatool doc isar-ref,
  7120 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7121 
  7122 * improved and simplified presentation of theories: better HTML markup
  7123 (including colors), graph views in several sizes; isatool usedir now
  7124 provides a proper interface for user theories (via -P option); actual
  7125 document preparation based on (PDF)LaTeX is available as well (for
  7126 new-style theories only); see isatool doc system for more information;
  7127 
  7128 * native support for Proof General, both for classic Isabelle and
  7129 Isabelle/Isar;
  7130 
  7131 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7132 using the graph browser tool;
  7133 
  7134 * Isabelle manuals now also available as PDF;
  7135 
  7136 * theory loader rewritten from scratch (may not be fully
  7137 bug-compatible); old loadpath variable has been replaced by show_path,
  7138 add_path, del_path, reset_path functions; new operations such as
  7139 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7140 isatool doc ref);
  7141 
  7142 * improved isatool install: option -k creates KDE application icon,
  7143 option -p DIR installs standalone binaries;
  7144 
  7145 * added ML_PLATFORM setting (useful for cross-platform installations);
  7146 more robust handling of platform specific ML images for SML/NJ;
  7147 
  7148 * the settings environment is now statically scoped, i.e. it is never
  7149 created again in sub-processes invoked from isabelle, isatool, or
  7150 Isabelle;
  7151 
  7152 * path element specification '~~' refers to '$ISABELLE_HOME';
  7153 
  7154 * in locales, the "assumes" and "defines" parts may be omitted if
  7155 empty;
  7156 
  7157 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7158 long arrows);
  7159 
  7160 * new print_mode "HTML";
  7161 
  7162 * new flag show_tags controls display of tags of theorems (which are
  7163 basically just comments that may be attached by some tools);
  7164 
  7165 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7166 mode and goal output format:
  7167 
  7168 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7169 244c244
  7170 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7171 ---
  7172 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7173 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7174 181c181
  7175 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7176 ---
  7177 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7178 
  7179 * function bind_thms stores lists of theorems (cf. bind_thm);
  7180 
  7181 * new shorthand tactics ftac, eatac, datac, fatac;
  7182 
  7183 * qed (and friends) now accept "" as result name; in that case the
  7184 theorem is not stored, but proper checks and presentation of the
  7185 result still apply;
  7186 
  7187 * theorem database now also indexes constants "Trueprop", "all",
  7188 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7189 
  7190 
  7191 *** HOL ***
  7192 
  7193 ** HOL arithmetic **
  7194 
  7195 * There are now decision procedures for linear arithmetic over nat and
  7196 int:
  7197 
  7198 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7199 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7200 are treated as atomic; subformulae not involving type `nat' or `int'
  7201 are ignored; quantified subformulae are ignored unless they are
  7202 positive universal or negative existential. The tactic has to be
  7203 invoked by hand and can be a little bit slow. In particular, the
  7204 running time is exponential in the number of occurrences of `min' and
  7205 `max', and `-' on `nat'.
  7206 
  7207 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7208 (negated) (in)equalities among the premises and the conclusion into
  7209 account (i.e. no compound formulae) and does not know about `min' and
  7210 `max', and `-' on `nat'. It is fast and is used automatically by the
  7211 simplifier.
  7212 
  7213 NB: At the moment, these decision procedures do not cope with mixed
  7214 nat/int formulae where the two parts interact, such as `m < n ==>
  7215 int(m) < int(n)'.
  7216 
  7217 * HOL/Numeral provides a generic theory of numerals (encoded
  7218 efficiently as bit strings); setup for types nat/int/real is in place;
  7219 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7220 int, existing theories and proof scripts may require a few additional
  7221 type constraints;
  7222 
  7223 * integer division and remainder can now be performed on constant
  7224 arguments;
  7225 
  7226 * many properties of integer multiplication, division and remainder
  7227 are now available;
  7228 
  7229 * An interface to the Stanford Validity Checker (SVC) is available through the
  7230 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7231 are proved automatically.  SVC must be installed separately, and its results
  7232 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7233 invocation of the underlying oracle).  For SVC see
  7234   http://verify.stanford.edu/SVC
  7235 
  7236 * IsaMakefile: the HOL-Real target now builds an actual image;
  7237 
  7238 
  7239 ** HOL misc **
  7240 
  7241 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7242 (in Isabelle/Isar) -- by Gertrud Bauer;
  7243 
  7244 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7245 analysis for assembly languages with subtypes;
  7246 
  7247 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7248 -- avoids syntactic ambiguities and treats state, transition, and
  7249 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7250 changed syntax and (many) tactics;
  7251 
  7252 * HOL/inductive: Now also handles more general introduction rules such
  7253   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7254   theorems are now maintained within the theory (maintained via the
  7255   "mono" attribute);
  7256 
  7257 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7258   (using function types) such as
  7259 
  7260   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7261 
  7262 * HOL/record: record_simproc (part of the default simpset) takes care
  7263 of selectors applied to updated records; record_split_tac is no longer
  7264 part of the default claset; update_defs may now be removed from the
  7265 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7266 
  7267   claset_ref () := claset() addSWrapper record_split_wrapper;
  7268   Delsimprocs [record_simproc]
  7269 
  7270 * HOL/typedef: fixed type inference for representing set; type
  7271 arguments now have to occur explicitly on the rhs as type constraints;
  7272 
  7273 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7274 names rather than an ML expression;
  7275 
  7276 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7277 supplied later.  Program schemes can be defined, such as
  7278     "While B C s = (if B s then While B C (C s) else s)"
  7279 where the well-founded relation can be chosen after B and C have been given.
  7280 
  7281 * HOL/List: the constructors of type list are now Nil and Cons;
  7282 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7283 course, ML tools referring to List.list.op # etc. have to be adapted;
  7284 
  7285 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7286 disabled by default; run isabelle with option -m HOL to get back to
  7287 the original Gordon/HOL-style output;
  7288 
  7289 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7290 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7291 
  7292 * HOL basic syntax simplified (more orthogonal): all variants of
  7293 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7294 Eps operator is provided as well: "SOME x. P[x]";
  7295 
  7296 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7297 
  7298 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7299 thus available for user theories;
  7300 
  7301 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7302 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7303 time;
  7304 
  7305 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7306 several times and then mp;
  7307 
  7308 
  7309 *** LK ***
  7310 
  7311 * the notation <<...>> is now available as a notation for sequences of
  7312 formulas;
  7313 
  7314 * the simplifier is now installed
  7315 
  7316 * the axiom system has been generalized (thanks to Soren Heilmann)
  7317 
  7318 * the classical reasoner now has a default rule database
  7319 
  7320 
  7321 *** ZF ***
  7322 
  7323 * new primrec section allows primitive recursive functions to be given
  7324 directly (as in HOL) over datatypes and the natural numbers;
  7325 
  7326 * new tactics induct_tac and exhaust_tac for induction (or case
  7327 analysis) over datatypes and the natural numbers;
  7328 
  7329 * the datatype declaration of type T now defines the recursor T_rec;
  7330 
  7331 * simplification automatically does freeness reasoning for datatype
  7332 constructors;
  7333 
  7334 * automatic type-inference, with AddTCs command to insert new
  7335 type-checking rules;
  7336 
  7337 * datatype introduction rules are now added as Safe Introduction rules
  7338 to the claset;
  7339 
  7340 * the syntax "if P then x else y" is now available in addition to
  7341 if(P,x,y);
  7342 
  7343 
  7344 *** Internal programming interfaces ***
  7345 
  7346 * tuned simplifier trace output; new flag debug_simp;
  7347 
  7348 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7349 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7350 
  7351 * AxClass.axclass_tac lost the theory argument;
  7352 
  7353 * tuned current_goals_markers semantics: begin / end goal avoids
  7354 printing empty lines;
  7355 
  7356 * removed prs and prs_fn hook, which was broken because it did not
  7357 include \n in its semantics, forcing writeln to add one
  7358 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7359 string -> unit if you really want to output text without newline;
  7360 
  7361 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7362 plain output, interface builders may have to enable 'isabelle_font'
  7363 mode to get Isabelle font glyphs as before;
  7364 
  7365 * refined token_translation interface; INCOMPATIBILITY: output length
  7366 now of type real instead of int;
  7367 
  7368 * theory loader actions may be traced via new ThyInfo.add_hook
  7369 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7370 your own database of information attached to *whole* theories -- as
  7371 opposed to intra-theory data slots offered via TheoryDataFun;
  7372 
  7373 * proper handling of dangling sort hypotheses (at last!);
  7374 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7375 extra sort hypotheses that can be witnessed from the type signature;
  7376 the force_strip_shyps flag is gone, any remaining shyps are simply
  7377 left in the theorem (with a warning issued by strip_shyps_warning);
  7378 
  7379 
  7380 
  7381 New in Isabelle98-1 (October 1998)
  7382 ----------------------------------
  7383 
  7384 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7385 
  7386 * several changes of automated proof tools;
  7387 
  7388 * HOL: major changes to the inductive and datatype packages, including
  7389 some minor incompatibilities of theory syntax;
  7390 
  7391 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7392 called `inj_on';
  7393 
  7394 * HOL: removed duplicate thms in Arith:
  7395   less_imp_add_less  should be replaced by  trans_less_add1
  7396   le_imp_add_le      should be replaced by  trans_le_add1
  7397 
  7398 * HOL: unary minus is now overloaded (new type constraints may be
  7399 required);
  7400 
  7401 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7402 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7403 now taken as an integer constant.
  7404 
  7405 * Pure: ML function 'theory_of' renamed to 'theory';
  7406 
  7407 
  7408 *** Proof tools ***
  7409 
  7410 * Simplifier:
  7411   1. Asm_full_simp_tac is now more aggressive.
  7412      1. It will sometimes reorient premises if that increases their power to
  7413         simplify.
  7414      2. It does no longer proceed strictly from left to right but may also
  7415         rotate premises to achieve further simplification.
  7416      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7417      old Asm_full_simp_tac in that it does not rotate premises.
  7418   2. The simplifier now knows a little bit about nat-arithmetic.
  7419 
  7420 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7421 allows for selected deletion of wrappers, by introduction of names for
  7422 wrapper functionals.  This implies that addbefore, addSbefore,
  7423 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7424 and that adding two tactics with the same name overwrites the first
  7425 one (emitting a warning).
  7426   type wrapper = (int -> tactic) -> (int -> tactic)
  7427   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7428   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7429   delWrapper, delSWrapper: claset *  string            -> claset
  7430   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7431 
  7432 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7433 semantics; addbefore now affects only the unsafe part of step_tac
  7434 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7435 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7436 by Force_tac;
  7437 
  7438 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7439 compWrapper; added safe wrapper (and access functions for it);
  7440 
  7441 * HOL/split_all_tac is now much faster and fails if there is nothing
  7442 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7443 and the names of the automatically generated variables have changed.
  7444 split_all_tac has moved within claset() from unsafe wrappers to safe
  7445 wrappers, which means that !!-bound variables are split much more
  7446 aggressively, and safe_tac and clarify_tac now split such variables.
  7447 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7448 Note: the same holds for record_split_tac, which does the job of
  7449 split_all_tac for record fields.
  7450 
  7451 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7452 permanently to the default simpset using Addsplits just like
  7453 Addsimps. They can be removed via Delsplits just like
  7454 Delsimps. Lower-case versions are also available.
  7455 
  7456 * HOL/Simplifier: The rule split_if is now part of the default
  7457 simpset. This means that the simplifier will eliminate all occurrences
  7458 of if-then-else in the conclusion of a goal. To prevent this, you can
  7459 either remove split_if completely from the default simpset by
  7460 `Delsplits [split_if]' or remove it in a specific call of the
  7461 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7462 other case splitting rules to/from the default simpset: every datatype
  7463 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7464 t is the name of the datatype).
  7465 
  7466 * Classical reasoner / Simplifier combination: new force_tac (and
  7467 derivatives Force_tac, force) combines rewriting and classical
  7468 reasoning (and whatever other tools) similarly to auto_tac, but is
  7469 aimed to solve the given subgoal completely.
  7470 
  7471 
  7472 *** General ***
  7473 
  7474 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7475 and `goalw': the theory is no longer needed as an explicit argument -
  7476 the current theory context is used; assumptions are no longer returned
  7477 at the ML-level unless one of them starts with ==> or !!; it is
  7478 recommended to convert to these new commands using isatool fixgoal
  7479 (backup your sources first!);
  7480 
  7481 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7482 the current theory context, and 'theory' to lookup stored theories;
  7483 
  7484 * new theory section 'locale' for declaring constants, assumptions and
  7485 definitions that have local scope;
  7486 
  7487 * new theory section 'nonterminals' for purely syntactic types;
  7488 
  7489 * new theory section 'setup' for generic ML setup functions
  7490 (e.g. package initialization);
  7491 
  7492 * the distribution now includes Isabelle icons: see
  7493 lib/logo/isabelle-{small,tiny}.xpm;
  7494 
  7495 * isatool install - install binaries with absolute references to
  7496 ISABELLE_HOME/bin;
  7497 
  7498 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7499 
  7500 * print mode 'emacs' reserved for Isamode;
  7501 
  7502 * support multiple print (ast) translations per constant name;
  7503 
  7504 * theorems involving oracles are now printed with a suffixed [!];
  7505 
  7506 
  7507 *** HOL ***
  7508 
  7509 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7510 
  7511 * HOL/inductive package reorganized and improved: now supports mutual
  7512 definitions such as
  7513 
  7514   inductive EVEN ODD
  7515     intrs
  7516       null "0 : EVEN"
  7517       oddI "n : EVEN ==> Suc n : ODD"
  7518       evenI "n : ODD ==> Suc n : EVEN"
  7519 
  7520 new theorem list "elims" contains an elimination rule for each of the
  7521 recursive sets; inductive definitions now handle disjunctive premises
  7522 correctly (also ZF);
  7523 
  7524 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7525 "mutual_induct" no longer exists - the induction rule is always
  7526 contained in "induct";
  7527 
  7528 
  7529 * HOL/datatype package re-implemented and greatly improved: now
  7530 supports mutually recursive datatypes such as
  7531 
  7532   datatype
  7533     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7534             | SUM ('a aexp) ('a aexp)
  7535             | DIFF ('a aexp) ('a aexp)
  7536             | NUM 'a
  7537   and
  7538     'a bexp = LESS ('a aexp) ('a aexp)
  7539             | AND ('a bexp) ('a bexp)
  7540             | OR ('a bexp) ('a bexp)
  7541 
  7542 as well as indirectly recursive datatypes such as
  7543 
  7544   datatype
  7545     ('a, 'b) term = Var 'a
  7546                   | App 'b ((('a, 'b) term) list)
  7547 
  7548 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7549 induction on mutually / indirectly recursive datatypes.
  7550 
  7551 Primrec equations are now stored in theory and can be accessed via
  7552 <function_name>.simps.
  7553 
  7554 INCOMPATIBILITIES:
  7555 
  7556   - Theories using datatypes must now have theory Datatype as an
  7557     ancestor.
  7558   - The specific <typename>.induct_tac no longer exists - use the
  7559     generic induct_tac instead.
  7560   - natE has been renamed to nat.exhaust - use exhaust_tac
  7561     instead of res_inst_tac ... natE. Note that the variable
  7562     names in nat.exhaust differ from the names in natE, this
  7563     may cause some "fragile" proofs to fail.
  7564   - The theorems split_<typename>_case and split_<typename>_case_asm
  7565     have been renamed to <typename>.split and <typename>.split_asm.
  7566   - Since default sorts of type variables are now handled correctly,
  7567     some datatype definitions may have to be annotated with explicit
  7568     sort constraints.
  7569   - Primrec definitions no longer require function name and type
  7570     of recursive argument.
  7571 
  7572 Consider using isatool fixdatatype to adapt your theories and proof
  7573 scripts to the new package (backup your sources first!).
  7574 
  7575 
  7576 * HOL/record package: considerably improved implementation; now
  7577 includes concrete syntax for record types, terms, updates; theorems
  7578 for surjective pairing and splitting !!-bound record variables; proof
  7579 support is as follows:
  7580 
  7581   1) standard conversions (selectors or updates applied to record
  7582 constructor terms) are part of the standard simpset;
  7583 
  7584   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7585 made part of standard simpset and claset via addIffs;
  7586 
  7587   3) a tactic for record field splitting (record_split_tac) is part of
  7588 the standard claset (addSWrapper);
  7589 
  7590 To get a better idea about these rules you may retrieve them via
  7591 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7592 the name of your record type.
  7593 
  7594 The split tactic 3) conceptually simplifies by the following rule:
  7595 
  7596   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7597 
  7598 Thus any record variable that is bound by meta-all will automatically
  7599 blow up into some record constructor term, consequently the
  7600 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7601 solve record problems automatically.
  7602 
  7603 
  7604 * reorganized the main HOL image: HOL/Integ and String loaded by
  7605 default; theory Main includes everything;
  7606 
  7607 * automatic simplification of integer sums and comparisons, using cancellation;
  7608 
  7609 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7610 
  7611 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7612 
  7613 * many new identities for unions, intersections, set difference, etc.;
  7614 
  7615 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7616 called split_if, split_split, split_sum_case and split_nat_case (to go
  7617 with add/delsplits);
  7618 
  7619 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7620 (?x::unit) = (); this is made part of the default simpset, which COULD
  7621 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7622 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7623 unit_abs_eta_conv is added in order to counter the effect of
  7624 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7625 %u.f();
  7626 
  7627 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7628 makes more sense);
  7629 
  7630 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7631   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7632   disjointness reasoning but breaking a few old proofs.
  7633 
  7634 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7635 to 'converse' from 'inverse' (for compatibility with ZF and some
  7636 literature);
  7637 
  7638 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7639 the well-founded relation;
  7640 
  7641 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7642     Compl A.  The "Compl" syntax remains available as input syntax for this
  7643     release ONLY.
  7644 
  7645 * HOL/Update: new theory of function updates:
  7646     f(a:=b) == %x. if x=a then b else f x
  7647 may also be iterated as in f(a:=b,c:=d,...);
  7648 
  7649 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7650 
  7651 * HOL/List:
  7652   - new function list_update written xs[i:=v] that updates the i-th
  7653     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7654   - new function `upt' written [i..j(] which generates the list
  7655     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7656     bound write [i..j], which is a shorthand for [i..j+1(].
  7657   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7658 
  7659 * HOL/Arith:
  7660   - removed 'pred' (predecessor) function;
  7661   - generalized some theorems about n-1;
  7662   - many new laws about "div" and "mod";
  7663   - new laws about greatest common divisors (see theory ex/Primes);
  7664 
  7665 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7666 instead of "inverse";
  7667 
  7668 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7669   of the multiset ordering;
  7670 
  7671 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7672   (not included by default);
  7673 
  7674 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7675 
  7676 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7677   programs, i.e. different program variables may have different types.
  7678 
  7679 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7680   [previously, this check worked only if the rewrite rule was unconditional]
  7681   Now rew can involve either definitions or equalities (either == or =).
  7682 
  7683 
  7684 *** ZF ***
  7685 
  7686 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7687   only the theorems proved on ZF.ML;
  7688 
  7689 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7690   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7691   disjointness reasoning but breaking a few old proofs.
  7692 
  7693 * ZF/Update: new theory of function updates
  7694     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7695   may also be iterated as in f(a:=b,c:=d,...);
  7696 
  7697 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7698 
  7699 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7700   [previously, this check worked only if the rewrite rule was unconditional]
  7701   Now rew can involve either definitions or equalities (either == or =).
  7702 
  7703 * case_tac provided for compatibility with HOL
  7704     (like the old excluded_middle_tac, but with subgoals swapped)
  7705 
  7706 
  7707 *** Internal programming interfaces ***
  7708 
  7709 * Pure: several new basic modules made available for general use, see
  7710 also src/Pure/README;
  7711 
  7712 * improved the theory data mechanism to support encapsulation (data
  7713 kind name replaced by private Object.kind, acting as authorization
  7714 key); new type-safe user interface via functor TheoryDataFun; generic
  7715 print_data function becomes basically useless;
  7716 
  7717 * removed global_names compatibility flag -- all theory declarations
  7718 are qualified by default;
  7719 
  7720 * module Pure/Syntax now offers quote / antiquote translation
  7721 functions (useful for Hoare logic etc. with implicit dependencies);
  7722 see HOL/ex/Antiquote for an example use;
  7723 
  7724 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7725 cterm -> thm;
  7726 
  7727 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7728 subgoal;
  7729 
  7730 * Display.print_goals function moved to Locale.print_goals;
  7731 
  7732 * standard print function for goals supports current_goals_markers
  7733 variable for marking begin of proof, end of proof, start of goal; the
  7734 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7735 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7736 for example;
  7737 
  7738 
  7739 
  7740 New in Isabelle98 (January 1998)
  7741 --------------------------------
  7742 
  7743 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7744 
  7745 * changed lexical syntax of terms / types: dots made part of long
  7746 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7747 
  7748 * simpset (and claset) reference variable replaced by functions
  7749 simpset / simpset_ref;
  7750 
  7751 * no longer supports theory aliases (via merge) and non-trivial
  7752 implicit merge of thms' signatures;
  7753 
  7754 * most internal names of constants changed due to qualified names;
  7755 
  7756 * changed Pure/Sequence interface (see Pure/seq.ML);
  7757 
  7758 
  7759 *** General Changes ***
  7760 
  7761 * hierachically structured name spaces (for consts, types, axms, thms
  7762 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7763 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7764 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7765 long_names for fully qualified output names; NOTE: ML programs
  7766 (special tactics, packages etc.) referring to internal names may have
  7767 to be adapted to cope with fully qualified names; in case of severe
  7768 backward campatibility problems try setting 'global_names' at compile
  7769 time to have enrything declared within a flat name space; one may also
  7770 fine tune name declarations in theories via the 'global' and 'local'
  7771 section;
  7772 
  7773 * reimplemented the implicit simpset and claset using the new anytype
  7774 data filed in signatures; references simpset:simpset ref etc. are
  7775 replaced by functions simpset:unit->simpset and
  7776 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7777 to patch your ML files accordingly;
  7778 
  7779 * HTML output now includes theory graph data for display with Java
  7780 applet or isatool browser; data generated automatically via isatool
  7781 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7782 
  7783 * defs may now be conditional; improved rewrite_goals_tac to handle
  7784 conditional equations;
  7785 
  7786 * defs now admits additional type arguments, using TYPE('a) syntax;
  7787 
  7788 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7789 creates a new theory node; implicit merge of thms' signatures is
  7790 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7791 transfer:theory->thm->thm in (rare) cases;
  7792 
  7793 * improved handling of draft signatures / theories; draft thms (and
  7794 ctyps, cterms) are automatically promoted to real ones;
  7795 
  7796 * slightly changed interfaces for oracles: admit many per theory, named
  7797 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7798 
  7799 * print_goals: optional output of const types (set show_consts and
  7800 show_types);
  7801 
  7802 * improved output of warnings (###) and errors (***);
  7803 
  7804 * subgoal_tac displays a warning if the new subgoal has type variables;
  7805 
  7806 * removed old README and Makefiles;
  7807 
  7808 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7809 
  7810 * removed obsolete init_pps and init_database;
  7811 
  7812 * deleted the obsolete tactical STATE, which was declared by
  7813     fun STATE tacfun st = tacfun st st;
  7814 
  7815 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7816 (which abbreviates $HOME);
  7817 
  7818 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7819 use isatool fixseq to adapt your ML programs (this works for fully
  7820 qualified references to the Sequence structure only!);
  7821 
  7822 * use_thy no longer requires writable current directory; it always
  7823 reloads .ML *and* .thy file, if either one is out of date;
  7824 
  7825 
  7826 *** Classical Reasoner ***
  7827 
  7828 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7829 tactics that use classical reasoning to simplify a subgoal without
  7830 splitting it into several subgoals;
  7831 
  7832 * Safe_tac: like safe_tac but uses the default claset;
  7833 
  7834 
  7835 *** Simplifier ***
  7836 
  7837 * added simplification meta rules:
  7838     (asm_)(full_)simplify: simpset -> thm -> thm;
  7839 
  7840 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7841 logics (again);
  7842 
  7843 * added prems argument to simplification procedures;
  7844 
  7845 * HOL, FOL, ZF: added infix function `addsplits':
  7846   instead of `<simpset> setloop (split_tac <thms>)'
  7847   you can simply write `<simpset> addsplits <thms>'
  7848 
  7849 
  7850 *** Syntax ***
  7851 
  7852 * TYPE('a) syntax for type reflection terms;
  7853 
  7854 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7855 
  7856 * pretty printer: changed order of mixfix annotation preference (again!);
  7857 
  7858 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7859 
  7860 
  7861 *** HOL ***
  7862 
  7863 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7864   with `addloop' of the simplifier to faciliate case splitting in premises.
  7865 
  7866 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7867 
  7868 * HOL/Auth: new protocol proofs including some for the Internet
  7869   protocol TLS;
  7870 
  7871 * HOL/Map: new theory of `maps' a la VDM;
  7872 
  7873 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7874 cancelling out common nat summands from =, <, <= (in)equalities, or
  7875 differences; simplification procedures nat_cancel_factor for
  7876 cancelling common factor from =, <, <= (in)equalities over natural
  7877 sums; nat_cancel contains both kinds of procedures, it is installed by
  7878 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7879 
  7880 * HOL/simplifier: terms of the form
  7881   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7882   are rewritten to
  7883   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7884   and those of the form
  7885   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7886   are rewritten to
  7887   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7888 
  7889 * HOL/datatype
  7890   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7891 
  7892   P(t_case f1 ... fn x) =
  7893      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7894         ...
  7895        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7896      )
  7897 
  7898   and a theorem `split_t_case_asm' of the form
  7899 
  7900   P(t_case f1 ... fn x) =
  7901     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7902         ...
  7903        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7904      )
  7905   which can be added to a simpset via `addsplits'. The existing theorems
  7906   expand_list_case and expand_option_case have been renamed to
  7907   split_list_case and split_option_case.
  7908 
  7909 * HOL/Arithmetic:
  7910   - `pred n' is automatically converted to `n-1'.
  7911     Users are strongly encouraged not to use `pred' any longer,
  7912     because it will disappear altogether at some point.
  7913   - Users are strongly encouraged to write "0 < n" rather than
  7914     "n ~= 0". Theorems and proof tools have been modified towards this
  7915     `standard'.
  7916 
  7917 * HOL/Lists:
  7918   the function "set_of_list" has been renamed "set" (and its theorems too);
  7919   the function "nth" now takes its arguments in the reverse order and
  7920   has acquired the infix notation "!" as in "xs!n".
  7921 
  7922 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7923 
  7924 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7925   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7926 
  7927 * HOL/record: extensible records with schematic structural subtyping
  7928 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7929 still lacks various theorems and concrete record syntax;
  7930 
  7931 
  7932 *** HOLCF ***
  7933 
  7934 * removed "axioms" and "generated by" sections;
  7935 
  7936 * replaced "ops" section by extended "consts" section, which is capable of
  7937   handling the continuous function space "->" directly;
  7938 
  7939 * domain package:
  7940   . proves theorems immediately and stores them in the theory,
  7941   . creates hierachical name space,
  7942   . now uses normal mixfix annotations (instead of cinfix...),
  7943   . minor changes to some names and values (for consistency),
  7944   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7945   . separator between mutual domain defs: changed "," to "and",
  7946   . improved handling of sort constraints;  now they have to
  7947     appear on the left-hand side of the equations only;
  7948 
  7949 * fixed LAM <x,y,zs>.b syntax;
  7950 
  7951 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7952 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7953 
  7954 
  7955 *** FOL and ZF ***
  7956 
  7957 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7958   with `addloop' of the simplifier to faciliate case splitting in premises.
  7959 
  7960 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7961 in HOL, they strip ALL and --> from proved theorems;
  7962 
  7963 
  7964 
  7965 New in Isabelle94-8 (May 1997)
  7966 ------------------------------
  7967 
  7968 *** General Changes ***
  7969 
  7970 * new utilities to build / run / maintain Isabelle etc. (in parts
  7971 still somewhat experimental); old Makefiles etc. still functional;
  7972 
  7973 * new 'Isabelle System Manual';
  7974 
  7975 * INSTALL text, together with ./configure and ./build scripts;
  7976 
  7977 * reimplemented type inference for greater efficiency, better error
  7978 messages and clean internal interface;
  7979 
  7980 * prlim command for dealing with lots of subgoals (an easier way of
  7981 setting goals_limit);
  7982 
  7983 
  7984 *** Syntax ***
  7985 
  7986 * supports alternative (named) syntax tables (parser and pretty
  7987 printer); internal interface is provided by add_modesyntax(_i);
  7988 
  7989 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7990 be used in conjunction with the Isabelle symbol font; uses the
  7991 "symbols" syntax table;
  7992 
  7993 * added token_translation interface (may translate name tokens in
  7994 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7995 the current print_mode); IMPORTANT: user print translation functions
  7996 are responsible for marking newly introduced bounds
  7997 (Syntax.mark_boundT);
  7998 
  7999 * token translations for modes "xterm" and "xterm_color" that display
  8000 names in bold, underline etc. or colors (which requires a color
  8001 version of xterm);
  8002 
  8003 * infixes may now be declared with names independent of their syntax;
  8004 
  8005 * added typed_print_translation (like print_translation, but may
  8006 access type of constant);
  8007 
  8008 
  8009 *** Classical Reasoner ***
  8010 
  8011 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8012 some limitations.  Blast_tac...
  8013   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8014   + ignores elimination rules that don't have the correct format
  8015         (the conclusion MUST be a formula variable)
  8016   + ignores types, which can make HOL proofs fail
  8017   + rules must not require higher-order unification, e.g. apply_type in ZF
  8018     [message "Function Var's argument not a bound variable" relates to this]
  8019   + its proof strategy is more general but can actually be slower
  8020 
  8021 * substitution with equality assumptions no longer permutes other
  8022 assumptions;
  8023 
  8024 * minor changes in semantics of addafter (now called addaltern); renamed
  8025 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8026 (and access functions for it);
  8027 
  8028 * improved combination of classical reasoner and simplifier:
  8029   + functions for handling clasimpsets
  8030   + improvement of addss: now the simplifier is called _after_ the
  8031     safe steps.
  8032   + safe variant of addss called addSss: uses safe simplifications
  8033     _during_ the safe steps. It is more complete as it allows multiple
  8034     instantiations of unknowns (e.g. with slow_tac).
  8035 
  8036 *** Simplifier ***
  8037 
  8038 * added interface for simplification procedures (functions that
  8039 produce *proven* rewrite rules on the fly, depending on current
  8040 redex);
  8041 
  8042 * ordering on terms as parameter (used for ordered rewriting);
  8043 
  8044 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8045 
  8046 * the solver is now split into a safe and an unsafe part.
  8047 This should be invisible for the normal user, except that the
  8048 functions setsolver and addsolver have been renamed to setSolver and
  8049 addSolver; added safe_asm_full_simp_tac;
  8050 
  8051 
  8052 *** HOL ***
  8053 
  8054 * a generic induction tactic `induct_tac' which works for all datatypes and
  8055 also for type `nat';
  8056 
  8057 * a generic case distinction tactic `exhaust_tac' which works for all
  8058 datatypes and also for type `nat';
  8059 
  8060 * each datatype comes with a function `size';
  8061 
  8062 * patterns in case expressions allow tuple patterns as arguments to
  8063 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8064 
  8065 * primrec now also works with type nat;
  8066 
  8067 * recdef: a new declaration form, allows general recursive functions to be
  8068 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8069 
  8070 * the constant for negation has been renamed from "not" to "Not" to
  8071 harmonize with FOL, ZF, LK, etc.;
  8072 
  8073 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8074 infinite lists;
  8075 
  8076 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8077 
  8078 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8079 problems in commutative rings, using axiomatic type classes for + and *;
  8080 
  8081 * more examples in HOL/MiniML and HOL/Auth;
  8082 
  8083 * more default rewrite rules for quantifiers, union/intersection;
  8084 
  8085 * a new constant `arbitrary == @x.False';
  8086 
  8087 * HOLCF/IOA replaces old HOL/IOA;
  8088 
  8089 * HOLCF changes: derived all rules and arities
  8090   + axiomatic type classes instead of classes
  8091   + typedef instead of faking type definitions
  8092   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  8093   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  8094   + eliminated the types void, one, tr
  8095   + use unit lift and bool lift (with translations) instead of one and tr
  8096   + eliminated blift from Lift3.thy (use Def instead of blift)
  8097   all eliminated rules are derived as theorems --> no visible changes ;
  8098 
  8099 
  8100 *** ZF ***
  8101 
  8102 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8103 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8104 as ZF_cs addSIs [equalityI];
  8105 
  8106 
  8107 
  8108 New in Isabelle94-7 (November 96)
  8109 ---------------------------------
  8110 
  8111 * allowing negative levels (as offsets) in prlev and choplev;
  8112 
  8113 * super-linear speedup for large simplifications;
  8114 
  8115 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8116 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8117 FAIL); can suppress it using the command Delsimps (ex_simps @
  8118 all_simps); De Morgan laws are also now included, by default;
  8119 
  8120 * improved printing of ==>  :  ~:
  8121 
  8122 * new object-logic "Sequents" adds linear logic, while replacing LK
  8123 and Modal (thanks to Sara Kalvala);
  8124 
  8125 * HOL/Auth: correctness proofs for authentication protocols;
  8126 
  8127 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8128 examples on HOL/Auth);
  8129 
  8130 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8131 the rewriter and classical reasoner simultaneously;
  8132 
  8133 * function uresult no longer returns theorems in "standard" format;
  8134 regain previous version by: val uresult = standard o uresult;
  8135 
  8136 
  8137 
  8138 New in Isabelle94-6
  8139 -------------------
  8140 
  8141 * oracles -- these establish an interface between Isabelle and trusted
  8142 external reasoners, which may deliver results as theorems;
  8143 
  8144 * proof objects (in particular record all uses of oracles);
  8145 
  8146 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8147 
  8148 * "constdefs" section in theory files;
  8149 
  8150 * "primrec" section (HOL) no longer requires names;
  8151 
  8152 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8153 
  8154 
  8155 
  8156 New in Isabelle94-5
  8157 -------------------
  8158 
  8159 * reduced space requirements;
  8160 
  8161 * automatic HTML generation from theories;
  8162 
  8163 * theory files no longer require "..." (quotes) around most types;
  8164 
  8165 * new examples, including two proofs of the Church-Rosser theorem;
  8166 
  8167 * non-curried (1994) version of HOL is no longer distributed;
  8168 
  8169 
  8170 
  8171 New in Isabelle94-4
  8172 -------------------
  8173 
  8174 * greatly reduced space requirements;
  8175 
  8176 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8177 
  8178 * searchable theorem database (see the section "Retrieving theorems" on
  8179 page 8 of the Reference Manual);
  8180 
  8181 * new examples, including Grabczewski's monumental case study of the
  8182 Axiom of Choice;
  8183 
  8184 * The previous version of HOL renamed to Old_HOL;
  8185 
  8186 * The new version of HOL (previously called CHOL) uses a curried syntax
  8187 for functions.  Application looks like f a b instead of f(a,b);
  8188 
  8189 * Mutually recursive inductive definitions finally work in HOL;
  8190 
  8191 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8192 translates to the operator "split";
  8193 
  8194 
  8195 
  8196 New in Isabelle94-3
  8197 -------------------
  8198 
  8199 * new infix operator, addss, allowing the classical reasoner to
  8200 perform simplification at each step of its search.  Example:
  8201         fast_tac (cs addss ss)
  8202 
  8203 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8204 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8205 look like (a,b) instead of <a,b>;
  8206 
  8207 * PLEASE NOTE: CHOL will eventually replace HOL!
  8208 
  8209 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8210 It translates to the operator "split".  A new theory of integers is available;
  8211 
  8212 * In ZF, integer numerals now denote two's-complement binary integers.
  8213 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8214 
  8215 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8216 of the Axiom of Choice;
  8217 
  8218 
  8219 
  8220 New in Isabelle94-2
  8221 -------------------
  8222 
  8223 * Significantly faster resolution;
  8224 
  8225 * the different sections in a .thy file can now be mixed and repeated
  8226 freely;
  8227 
  8228 * Database of theorems for FOL, HOL and ZF.  New
  8229 commands including qed, qed_goal and bind_thm store theorems in the database.
  8230 
  8231 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8232 a given theory (thms_of), or find out what theory a theorem was proved in
  8233 (theory_of_thm);
  8234 
  8235 * Bugs fixed in the inductive definition and datatype packages;
  8236 
  8237 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8238 and HOL_dup_cs obsolete;
  8239 
  8240 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8241 have been removed;
  8242 
  8243 * Simpler definition of function space in ZF;
  8244 
  8245 * new results about cardinal and ordinal arithmetic in ZF;
  8246 
  8247 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8248 types;
  8249 
  8250 :mode=text:wrap=hard:maxLineLen=72: